Patent Application
20170304883
The present invention relates to a cooling apparatus and a cooling method for a steel material.
Priority is claimed on Japanese Patent Application No. 2014-206255, filed on Oct. 7, 2014, Japanese Patent Application No. 2014-206256, filed on Oct. 7, 2014, Japanese Patent Application No. 2014-211900, filed on Oct. 16, 2014, and Japanese Patent Application No. 2014-211903, filed on Oct. 16, 2014, the contents of which are incorporated herein by reference.
In recent years, as structural steel materials used for building materials or mechanical components, those which have light weight and which have improved strength have been required. For example, as for an automotive steel material which is one of the structural steel materials, there is an increasing need to ensure safety for a vehicle body. In addition, in order to reduce the influence on the global environment, there is an increasing need to suppress CO2 emission during a manufacturing process. In order to satisfy the above-described needs, the automotive steel material which is lighter in weight and has further improved strength is required.
On the other hand, a microstructure of the automotive steel material is more diversified and complicated than that in the related art. In order to use this automotive steel material, a bending technique is required which enables bending to be performed to a steel material into various and complicated shapes.
In the related art, as the above-described bending technique, a bending technique is employed in which the bending is performed in a state where the steel material is locally heated, and immediately after the heating, the steel material is rapidly cooled with water. In this manner, the steel material is formed into a predetermined shape which includes a bent portion. According to this bending technique, it is possible to bend the steel material into a complicated shape and to lighten and strengthen the steel material. Furthermore, according to the above-described bending technique, excellent productivity is achieved since the bending can be performed to the steel material through a single process.
Patent Document 1 discloses the following bending technique. While the steel material rotatably gripped by a support device is extruded from an upstream side, the bending is performed to the steel material using a heating apparatus, a cooling apparatus, and movable roller dies which are disposed on a downstream side of the support device. According to the bending technique disclosed in Patent Document 1, the following method is disclosed. The steel material is locally heated using the heating apparatus so as to form a heated portion. A bending moment is provided for the heated portion by the movable roller dies. Thereafter, a cooling medium is ejected to the heated portion from the cooling apparatus, thereby cooling the heated portion.
Patent Document 2 discloses the following method. While the heated portion is formed in the steel material using the heating apparatus, inert gas or reducing gas is sprayed to the heated portion until the cooling medium is sprayed to the heated portion from the cooling apparatus. In this manner, a surface of the heated portion is prevented from being oxidized, thereby preventing a scale from being formed on the surface of the heated portion.
Patent Document 3 discloses the following method. A pipe body of the steel material externally fitted to a guide having a curved section is extruded while being heated inside a heating and molding furnace. After the pipe body is molded along the curved section, the cooling medium is ejected to the pipe body, thereby cooling the pipe body of the steel material.
Patent Document 4 discloses the following method. The steel material is cooled using the cooling apparatus for the steel material in which a plurality of headers having a nozzle for ejecting the cooling medium to the steel material are disposed in a longitudinal direction of the steel material. The cooling apparatus for the steel material disclosed in Patent Document 4 has at least two cooling medium supply systems which are independently openable and closeable. The header and any one of the cooling medium supply systems are connected to each other. In this manner, a cooling rate can be changed depending on a position in the longitudinal direction of the steel material. The cooling apparatus for the steel material disclosed in Patent Document 4 is the cooling apparatus for cooling the steel material (straight pipe) which is not subjected to bending.
[Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2007-83304
[Patent Document 2] Japanese Unexamined Patent Application, First Publication No. 2011-89151
[Patent Document 3] Japanese Unexamined Patent Application, First Publication No. H8-10856
[Patent Document 4] Japanese Unexamined Patent Application, First Publication No. 2006-283179
However, the present inventors performed temperature measurement of the steel material, collision pressure measurement of the cooling medium ejected to the heated portion, and numerical analysis. As a result, according to the cooling method for the steel material disclosed in Patent Document 1, cooling is insufficient during bending. Accordingly, the inventors found that an insufficient quenching may appear on a bent member manufactured by bending the steel material, that is, a fact that a steel material microstructure may become non-uniform. Specifically, the inventors found that the insufficient quenching appears on an outer side of the bent portion of the bent member.
As shown in
According to the cooling method for the steel material 200 in Patent Document 2, similarly to the cooling method for the steel material 200 in Patent Document 1, the insufficient quenching may also appear on the steel material 200.
According to the cooling method for the steel material 200 in Patent Document 2, the cooling medium is ejected from two locations along the feeding direction of the steel material 200. When viewed along the feeding direction of the steel material 200, an ejection position of the cooling medium located further upward is called a first position, and an ejection position of the cooling medium located further downward is called a second position.
According to the cooling method for the steel material 200 in Patent Document 2, at the first position, the cooling medium is obliquely ejected in the feeding direction of the steel material 200. At the second position, the cooling medium is ejected in a direction vertical to the feeding direction of the steel material 200. In a case where a bent shape of the steel material 200 is complicated, the cooling medium ejected from the first position collides with the steel material 200. However, the cooling medium ejected from the second position may not collide with the steel material 200 in a case where a bent shape of the steel material 200 is complicated.
Furthermore, Patent Document 2 does not disclose a specific control method of the cooling medium ejected from the second position. Therefore, the cooling medium ejected from the second position cannot pass through the cooling medium ejected from the first position flowing along the steel material 200. Consequently, it is considered that the cooling medium ejected from the second position does not reach the steel material 200.
For the above-described reason, according to the cooling method for the steel material 200 in Patent Document 2, similarly to the cooling method for the steel material 200 in Patent Document 1, the cooling medium does not collide with the outer circumferential surface of the bent portion, and the outer circumferential surface of a bent portion is insufficiently cooled. Consequently, the insufficient quenching may also appear on the steel material 200.
According to the cooling method for the steel material 200 in Patent Document 3, the cooling medium is ejected from a pair of hollow annular bodies internally having a nozzle to the steel material 200 inserted into the hollow annular bodies. A pair of the hollow annular bodies are disposed back and forth in accordance with a bent shape of the steel material 200. Therefore, in a case where the bending is performed to the steel material 200 in a direction different from a direction in which a pair of the hollow annular bodies are disposed, there is a possibility that the steel material 200 may come into contact with the hollow annular bodies during the bending. Since the cooling medium does not collide with the outer circumferential surface of the bent portion, the outer side of the bent portion is insufficiently cooled. Therefore, there is a possibility that the insufficient quenching may appear on the steel material 200.
The cooling method for the steel material 200 in Patent Document 4 is the cooling method for cooling the steel material (straight pipe) 200 which is not subjected to bending. Accordingly, in a case where the cooling method is used in cooling the steel material 200 which is subjected to bending, the cooling medium does not collide with the outer circumferential surface of the bent portion. Consequently, there is a possibility that the insufficient quenching may appear.
The present invention is made in view of the above-described circumstances, and an object thereof is to provide a cooling apparatus and a cooling method for a steel material, which can reduce an insufficient quenching of the steel material.
In order to solve the above-described problem and to achieve the object, the present invention adopts the following configurations.
(1) According to an aspect of the present invention, there is provided a cooling apparatus for a steel material in which one portion in a longitudinal direction of an elongated steel material is heated while the steel material is fed in the longitudinal direction in a state where one end portion of the steel material is gripped, and the one end portion is moved in a two-dimensional or three-dimensional direction so as to form the steel material into a predetermined shape including a bent portion and thereafter to cool a heated portion including the bent portion. The cooling apparatus includes a first cooling apparatus that ejects a first cooling medium to the heated portion, and a second cooling apparatus that is disposed on a downstream side than the first cooling apparatus when viewed along a feeding direction of the steel material, and that ejects a second cooling medium to the heated portion. A plurality of the second cooling apparatuses are disposed along the feeding direction, and flow rates of the second cooling media can be controlled independently of each other.
(2) In the cooling apparatus for a steel material described in (1) above, a configuration may be adopted which further includes a moving mechanism that maintains each arrangement interval to be constant between the respective second cooling apparatuses adjacent to each other, and that causes an arrangement of the respective second cooling apparatuses to follow the predetermined shape.
(3) In the cooling apparatus for a steel material described in (2) above, a configuration may be adopted in which the moving mechanism is a passive moving mechanism that has a contact portion which causes the arrangement of the respective second cooling apparatuses to follow the predetermined shape of the steel material by coming into contact with an outer shape of the steel material, and a connecting portion which connects the respective second cooling apparatuses adjacent to each other.
(4) In the cooling apparatus for a steel material described in (2) above, a configuration may be adopted in which the moving mechanism is a passive moving mechanism that has a contact portion which causes the arrangement of the respective second cooling apparatuses to follow the predetermined shape of the steel material by contacting with an outer shape of the steel material, and a guide portion which regulates a moving direction of the respective second cooling apparatuses.
(5) In the cooling apparatus for a steel material described in (2) above, a configuration may be adopted in which the moving mechanism is an active moving mechanism that has a drive unit which moves the respective second cooling apparatuses in accordance with the predetermined shape which is scheduled to apply to the steel material .
(6) In the cooling apparatus for a steel material described in any one aspect of (1) to (5) above, a configuration may be adopted in which the second cooling apparatus includes a plurality of cooling mechanisms that are disposed along a circumferential direction of the steel material, and that respectively eject the second cooling medium in a manner flow rates of the second cooling media are controllable independently of each other.
(7) In the cooling apparatus for the steel material described in (6) above, a configuration may be adopted in which the respective cooling mechanisms are disposed so that the second cooling media ejected from the respective cooling mechanisms do not cross each other until the second cooling media reach the steel material ejected from the respective cooling mechanisms.
(8) In the cooling apparatus for a steel material described in any one aspect of (1) to (7) above, a configuration may be adopted in which the second cooling apparatus located on a downstream side has a relatively larger inner diameter dimension of a space into which the steel material is inserted than the second cooling apparatus located on an upstream side when viewed along the feeding direction.
(9) In the cooling apparatus for a steel material described in any one aspect of (1) to (8) above, a configuration may be adopted which further includes a first draining mechanism that drains the first cooling medium flowing downward, at an upstream position than a collision position where the second cooling medium ejected from any one located at a most upstream side in the respective second cooling apparatuses collides with the steel material.
(10) In the cooling apparatus for a steel material described in any one aspect of (1) to (9) above, a configuration may be adopted which further includes a plurality of second draining mechanisms that drain the second cooling medium flowing downward, at a downstream position than a collision position where the second cooling medium ejected from any one of the respective second cooling apparatuses collides with the steel material.
(11) In the cooling apparatus for a steel material described in any one aspect of (1) to (10) above, a configuration may be adopted in which at least one of the respective second cooling apparatuses has a pulsation applying mechanism that applies a pulsation to the second cooling medium.
(12) In the cooling apparatus for a steel material described in any one aspect of (1) to (11) above, a configuration may be adopted in which at least a momentum of the second cooling medium ejected at a most upstream position in the second cooling media is greater than a momentum of the first cooling medium ejected at a position adjacent to the most upstream position.
(13) In the cooling apparatus for a steel material described in any one aspect of (1) to (12) above, a configuration may be adopted in which the first cooling medium is a columnar jet, and in which the second cooling medium is any one of a flat jet, a full cone jet, and an oval jet.
(14) According to an aspect of the present invention, there is provided a cooling method for a steel material in which one portion in a longitudinal direction of an elongated steel material is heated while the steel material is fed in the longitudinal direction in a state where one end portion of the steel material is gripped, and the one end portion is moved in a two-dimensional or three-dimensional direction so as to form the steel material into a predetermined shape including a bent portion and thereafter to cool a heated portion including the bent portion. The cooling method includes a first cooling process of ejecting a first cooling medium to the heated portion, and a second cooling process of ejecting a second cooling medium to the heated portion, on a downstream side than an ejection position of the first cooling apparatus when viewed along a feeding direction of the steel material. During the second cooling process, the second cooling media are ejected to a plurality of locations along the feeding direction of the steel material while flow rates of the second cooling media are controlled independently of each other.
(15) In the cooling method for a steel material described in (14) above, a configuration may be adopted in which the second cooling process includes a moving process of maintaining each ejection interval to be constant in the feeding direction during ejecting the second cooling media to a plurality of locations along the feeding direction, and of causing an arrangement of respective collision positions where the second cooling medium collides with the steel material to follow the predetermined shape of the steel material.
(16) In the cooling method for a steel material described in (15) above, a configuration may be adopted so that the moving process is a passive moving process in which the predetermined shape of the steel material which is obtained by contacting an outer shape of the steel material is reflected on each arrangement of a plurality of second cooling apparatuses which ejects the second cooling medium and which is disposed along the feeding direction, and the respective second cooling apparatuses are connected to each other so as to maintain each of the ejection interval to be constant in the feeding direction of the second cooling medium.
(17) In the cooling method for a steel material described in (15) above, a configuration may be adopted so that the moving process is a passive moving process in which the predetermined shape of the steel material which is obtained by contacting with an outer shape of the steel material is reflected on each arrangement of a plurality of second cooling apparatuses which ejects the second cooling medium and which is disposed along the feeding direction, and a moving direction of the respective second cooling apparatuses is regulated by a guide.
(18) In the cooling method for a steel material described in (15) above, a configuration may be adopted so that the moving process is an active moving process in which an ejection position of the second cooling medium is actively moved in accordance with the predetermined shape which is scheduled to apply to the steel material.
(19) In the cooling method for a steel material described in any one aspect of (14) to (18) above, a configuration may be adopted so that during the second cooling process, the second cooling media are ejected from a plurality of positions along a circumferential direction of the steel material in a manner flow rates of the second cooling media are controllable independently of each other in the second cooling process.
(20) In the cooling method for a steel material described in (19) above, a configuration may be adopted so that ejection positions of the second cooling media are disposed so that the second cooling media adjacent to each other in the circumferential direction do not cross each other until the second cooling media collide with the steel material.
(21) In the cooling method for a steel material described in any one aspect of (14) to (20) above, a configuration may be adopted which further includes a plurality of first draining processes of draining the first cooling medium flowing downward, at an upstream position from a collision position where the second cooling medium located at a most upstream side in the respective second cooling media collides with the steel material.
(22) In the cooling method for the steel material described in any one aspect of (14) to (21) above, a configuration may be adopted which further includes a second draining process of draining the second cooling medium flowing downward, at a downstream position than a collision position where the second cooling medium collides with the steel material in each of the plurality of locations.
(23) In the cooling method for the steel material described in any one aspect of (14) to (22) above, a configuration may be adopted which further includes a pulsation applying process of applying at least one of the second cooling media.
(24) In the cooling method for the steel material described in any one aspect of (14) to (23) above, a configuration may be adopted so that at least a momentum of the second cooling medium ejected at a most upstream position in the second cooling media is greater than a momentum of the first cooling medium ejected at a position adjacent to the most upstream position.
According to the above-described aspects, it is possible to provide a cooling apparatus and a cooling method for a steel material, which can reduce an insufficient quenching when bending the steel material.
Hereinafter, a cooling apparatus for a steel material and a cooling method for a steel material according to embodiments will be described with reference to the drawings.
First, a bending device including a cooling apparatus for a steel material 10 according to a first embodiment will be described with reference to
The bending device 1 performs bending of steel material 10 while intermittently or continuously feeding the elongated steel material 10. In a case where the bending device 1 is viewed along a feeding direction of the steel material 10, the bending device 1 includes a feeding apparatus 20, a heating apparatus 21, a first cooling apparatus 22, a second cooling apparatus 23, and a bending apparatus 24, sequentially from an upstream side.
In the present embodiment, a direction in which the steel material 10 is fed in a longitudinal direction (pipe axis direction) (X-axis direction in
A configuration of the bending device 1 is not limited to the above-described configuration. In addition, in the present embodiment, a case will be described where the steel material 10 is a flat steel pipe (flat pipe). However, for example, the present invention is also applicable to a case where the steel material 10 is a steel pipe such as a round pipe and a rectangular pipe, or a case where the steel material 10 has no pipe shape.
(Feeding Apparatus)
The feeding apparatus 20 intermittently or continuously feeds the steel material 10, whose one end portion (front end portion) is gripped by the bending apparatus 24, in the longitudinal direction (pipe axis direction). The feeding apparatus 20 can adopt a known configuration, and is not particularly limited to a specific configuration. As shown in
(Heating Apparatus)
The heating apparatus 21 heats a portion in the longitudinal direction of the steel material 10 using a high frequency induction heating coil which is annularly disposed around the steel material 10, for example.
(Bending Apparatus)
The bending apparatus 24 grips the front end portion of the steel material 10, and moves the front end portion of the steel material 10 in a two-dimensional direction or three-dimensional direction, thereby forming a bend (bent portion) 11 in the steel material 10. The bending apparatus 24 has a clamp 25 for gripping the front end portion of the steel material 10, and a drive arm 26 for moving the clamp 25.
(Cooling Apparatus)
The cooling apparatus for the steel material 10 according to the present embodiment includes a first cooling apparatus (primary cooling apparatus) 22 and a second cooling apparatus (secondary cooling apparatus) 23.
The first cooling apparatus 22 ejects a first cooling medium 35 to a portion in the longitudinal direction of the steel material 10 heated by the heating apparatus 21 (hereinafter, referred to as a heated portion). The heated portion includes the bent portion 11.
When viewed along the feeding direction of the steel material 10, the second cooling apparatus 23 is disposed on the downstream side from the first cooling apparatus 22, and ejects a second cooling medium 55 to the heated portion. The second cooling apparatus 23 includes a plurality of cooling mechanisms that are disposed along the feeding direction of the steel material 10, and that can control a flow rate of the second cooling medium 55 independently of each other. The second cooling apparatus 23 shown in
As the first cooling medium 35 and the second cooling medium 55, it is preferable to use cooling water.
Each detailed configuration of the first cooling apparatus 22 and the second cooling apparatus 23 will be described later.
In the bending device 1, in a state where the front end portion is gripped by the clamp 25, the feeding apparatus 20 feeds the steel material 10. The fed steel material 10 is heated to a predetermined temperature by the heating apparatus 21. Furthermore, the clamp 25 is moved in the two-dimensional direction or the three-dimensional direction by the drive arm 26, thereby providing the heated portion of the steel material 10 with a bending moment. In this manner, the steel material 10 is formed into a predetermined shape including the bent portion 11. After the bending moment is applied to the heated portion of the steel material 10, the steel material 10 is cooled by the first cooling medium 35 ejected from the first cooling apparatus 22. Furthermore, the steel material 10 is cooled by the second cooling medium 55 ejected from the second cooling apparatus 23.
In the present embodiment, cooling the steel material 10 using the first cooling medium 35 is referred to as primary cooling, and cooling the steel material 10 using the second cooling medium 55 is referred to as secondary cooling.
Next, the first cooling apparatus 22 and the second cooling apparatus 23 according to the present embodiment will be described.
(First Cooling Apparatus)
As shown in
According to ejecting the first cooling medium 35 from the first cooling apparatus 22 having the above-described configuration, it is possible to prevent the first cooling medium 35 from flowing toward the upstream side. Therefore, without hindering the steel material 10 from being heated by the heating apparatus 21, the first cooling apparatus 22 can perform the primary cooling on the steel material 10.
(Second Cooling Apparatus)
As shown in
(First Cooling Mechanism)
As shown in
Since the first cooling mechanism 40 includes the headers 50 to 53, it is possible to reliably cool the entire steel material 10 in the circumferential direction. Therefore, even in a case where the steel material 10 is formed in a complicated shape, it is possible to reduce an insufficient quenching appearing on the steel material 10.
The number of the headers 50 to 53 can be optionally set without being limited to the present embodiment.
The respective headers 50 to 53 have a spray nozzle 54. For example, as the spray nozzle 54, a flat nozzle, a full cone nozzle, or an oval nozzle is used. In a case where the above-described nozzles are used as the spray nozzle 54, the second cooling media 55 are respectively a flat jet, a full cone jet, and an oval jet.
The number of the spray nozzles 54 respectively disposed in the headers 50 to 53 is not limited to the number shown in
As shown in
The spray nozzle 54 of the respective headers 50 to 53 may be configured so that an ejection direction of the second cooling medium 55 can be adjusted. In this manner, the second cooling medium 55 can be ejected in accordance with a shape of the steel material 10. Even in a case where the steel material 10 is formed in a complicated shape, the second cooling medium 55 can be ejected to a circumferential surface of outer side of the bent portion 11 of the steel material 10. Therefore, even in the case where the steel material 10 is formed in the complicated shape, it is possible to reduce the insufficient quenching in a case where bending is performed to the steel material 10.
In particular, it is preferable to dispose the spray nozzle 54 of the upper header 50 and the lower header 51 in a direction in which a collision angle θ1 between the second cooling medium 55 ejected from the spray nozzle 54 and the steel material 10 is 45 degrees or smaller. If the collision angle θ1 between the second cooling medium 55 and the steel material 10 is 45 degrees or smaller, it is possible to prevent the second cooling medium 55, which collides with the steel material 10 from flowing toward the upstream side. A preferable lower limit value of the collision angle θ1 between the second cooling medium 55 and the steel material 10 is 20 degrees, for example.
It is preferable to dispose the respective spray nozzles 54 of the header 50 to 53 so that the second cooling media 55 ejected from the respective spray nozzles 54 do not cross each other until the second cooling media 55 ejected from the respective spray nozzles 54 reach the steel material 10. Since the respective spray nozzles 54 are disposed in this way, the second cooling media 55 ejected from the respective spray nozzles 54 do not interfere with each other. Accordingly, the second cooling medium 55 can be ejected to the steel material 10 using a desired collision position and a desired collision angle.
It is preferable that an ejection angle θ2 of the second cooling medium 55 ejected from the spray nozzle 54 of the upper header 50 and the lower header 51, and an ejection angle θ3 of the second cooling medium 55 ejected from the spray nozzle 54 of the lateral headers 52 and 53 are set to 10 to 70 degrees. However, in order to ensure cooling capability of the upper header 50 and the lower header 51 and to prevent an excessive increase in the number of nozzles, it is preferable that the ejection angle θ2 and the ejection angle θ3 are as wide as possible. If the ejection angle becomes larger, there is a possibility that the steel material 10 may be less likely to be uniformly cooled. Accordingly, it is preferable that the ejection angle θ2 and the ejection angle θ3 are approximately 50 degrees. However, in a case where a cooling surface of the steel material 10 is narrow, the ejection angle θ2 and the ejection angle θ3 may be approximately 10 degrees.
(Second Cooling Mechanism)
As shown in
As shown in
Next, a cooling method for the steel material 10 using the first cooling apparatus 22 and the second cooling apparatus 23 according to the present embodiment will be described with reference to
As shown in
In the cooling method for the steel material 10 according to the present embodiment, during the second cooling process, the second cooling media 55 are ejected to a plurality of locations along the feeding direction of the steel material 10 while controlling the flow rates of the second cooling media 55 independently of each other.
As shown in
After the cooling using the first cooling medium 35, the steel material 10 is cooled by the second cooling medium 55 ejected from the first cooling mechanism 40 and the second cooling mechanism 41. The steel material 10 is cooled to below the martensitic transformation finish temperature Mf, or to approximately room temperature (for example, room temperature to 300° C.) by the second cooling medium 55. Since the steel material 10 is already cooled through the primary cooling, the steel material 10 is stably and efficiently cooled in a nuclear boiling region during the secondary cooling.
As shown in
For the above-described reason, according to the cooling method for the steel material 10 in the present embodiment, it is possible to reduce the insufficient quenching when bending the steel material 10, which is a problem in the related art. Therefore, proper bending can be performed to the steel material 10.
In a case where a momentum of the first cooling medium 35 and a momentum of the second cooling medium 55 are compared with each other, it is preferable that the momentum of the second cooling medium 55 at least ejected from the first cooling mechanism 40 located at the most upstream position in the second cooling apparatus 23 is greater than the momentum of the first cooling medium 35 ejected from the first cooling apparatus 22 located at a position adjacent to the first cooling mechanism 40.
The momentum of the second cooling medium 55 ejected from the first cooling mechanism 40 is greater than the momentum of the first cooling medium 35 ejected from the first cooling apparatus 22. Accordingly, when the second cooling medium 55 ejected from the first cooling mechanism 40 collides with the steel material 10, even in a case where the first cooling medium 35 is present between the second cooling medium 55 and the steel material 10, the second cooling medium 55 ejected from the first cooling mechanism 40 can pass through the first cooling medium 35.
In this manner, the second cooling medium 55 ejected from the first cooling mechanism 40 reliably reaches the steel material 10, and cools the steel material 10 effectively, since the first cooling medium 35 whose temperature rises due to cooling the steel material 10 does not flow to the downstream side from the first cooling mechanism 40.
It is preferable that the momentum of the second cooling medium 55 is 1.5 times to 5 times the momentum of the first cooling medium 35.
During the second cooling process, the second cooling media 55 may be ejected from a plurality of positions along the circumferential direction of the steel material 10 while controlling the flow rates of the second cooling media 55 independently of each other. According to ejecting the second cooling media 55 from the plurality of positions along the circumferential direction of the steel material 10 while controlling the flow rates of the second cooling media 55 independently of each other, it is possible to reliably cool the entire steel material 10 in the circumferential direction. Therefore, even in a case where the steel material 10 is formed in a complicated shape, it is possible to reduce the insufficient quenching appearing on the steel material 10.
Next, the cooling apparatus for the steel material 10 according to a second embodiment will be described.
With regard to elements having the same configuration as that of the bending device 1 for the steel material 10 according to the first embodiment, a detailed description will be omitted.
Similarly to the first embodiment, the cooling apparatus for the steel material 10 according to the present embodiment includes the first cooling apparatus 22, but includes a second cooling apparatus 223 unlike the first embodiment.
As shown in
The second cooling apparatus 223 has the connecting members 290 and 293. Accordingly, even if bending is performed to the steel material 10 as shown in
Next, a detailed configuration of the second cooling apparatus 223 according to the present embodiment will be described.
As shown in
As shown in
In addition, a plurality of ejection ports 252 for ejecting the second cooling medium 55 of a columnar jet are also formed on an inner side surface of the header 250. The second cooling media 55 ejected from the plurality of ejection ports 252 are ejected in the vertical direction so that upper and lower surfaces of the steel material 10 are cooled.
Supply pipes 260 to 263 for supplying the second cooling medium 55 are connected to an outer circumferential portion of the header 250. The upper supply pipes 260 and 261 are connected to an upper surface of the header 250, and the lower supply pipes 262 and 263 are connected to a lower surface of the header 250. The reason for disposing a plurality of supply pipes 260 to 263 in a tangential direction of the header 250 is to stabilize the ejection of the second cooling medium 55 and to ensure a water amount.
For example, when viewed along the feeding direction of the steel material 10, the second cooling medium 55 is supplied to the header 250 from the upper supply pipe 260 and the lower supply pipe 263 which are located on a diagonal line of the header 250, and the supply of the second cooling medium 55 from the other upper supply pipe 261 and the other lower supply pipe 262 is stopped. In a case where the second cooling medium 55 is supplied as described above, the supplied second cooling medium 55 flows while swirling inside the annular header 250. Accordingly, the second cooling medium 55 can be uniformly ejected in the circumferential direction of the steel material 10 from the ejection ports 251 and 252 of the header 250.
When the second cooling medium 55 is supplied to the header 250, the second cooling medium 55 may be supplied from the upper supply pipe 261 and the lower supply pipe 262, and the supply of the second cooling medium 55 from the upper supply pipe 260 and the lower supply pipe 263 may be stopped. In order to ensure the water amount of the second cooling medium 55, the second cooling medium 55 may be supplied from all of the supply pipes 260 to 263.
As shown in
As shown in
Supply pipes 265 to 268 for supplying the second cooling medium 55 are connected to an outer circumferential portion of the header 255. The upper supply pipes 265 and 266 are connected to an upper surface of the header 255, and the lower supply pipes 267 and 268 are connected to a lower surface of the header 255. The method of supplying the second cooling medium 55 to the header 255 from the supply pipes 265 to 268 is the same as the method of supplying the second cooling medium 55 to the header 250 from the supply pipes 260 to 263 in the above-described first cooling mechanism 240.
Although not shown, the third cooling mechanism 242 has the same configuration as that of the above-described second cooling mechanism 241.
A pair of contact members (contact portions) 280 and 280 are disposed on the upstream side of the header 255. The contact member 280 has a substantially triangular shape in a side view, and comes into contact with the outer shape of the steel material 10. For example, as the contact member 280, a material which has heat resistance without giving damage to the steel material 10 such as a fluororesin is used.
The contact member 280 is supported by a support member 281 attached to the header 255. The contact member 280 is detachable from the support member 281 since the contact member 280 is replaced in accordance with a size of the steel material 10 which is a workpiece.
In the second cooling mechanism 241 and the third cooling mechanism 242, the contact member 280 contacts with the steel material 10. Accordingly, the contact member 280 moves to follow the movement of the steel material 10 formed in a predetermined shape including the bent portion 11. In accordance with the movement of the contact member 280, the header 255 of the second cooling mechanism 241 and the header 255 of the third cooling mechanism 242 move to follow the movement of the steel material 10.
In this manner, even in a case where complicated bending is performed to the steel material 10, the collision position and the collision angle where the second cooling medium 55 ejected from the header 255 of the second cooling mechanism 241 and the header 255 of the third cooling mechanism 242 collides with the steel material 10 can be maintained constant. Therefore, without depending on a shape of the steel material 10, the second cooling medium 55 can be ejected to a circumferential surface including the outer side of the bent portion 11 of the steel material 10. Accordingly, it is possible to reduce the insufficient quenching when bending the steel material 10.
The connecting member (connecting portion) 290 which connects the center of the first cooling mechanism 240 and the center of the second cooling mechanism 241 to each other is disposed in the first cooling mechanism 240 and the second cooling mechanism 241 which are adjacent to each other as shown in
As shown in
Similarly, the connecting member 293 which connects the center of the second cooling mechanism 241 and the center of the third cooling mechanism 242 to each other is also disposed in the second cooling mechanism 241 and the third cooling mechanism 242. One end portion of the connecting member 293 is fixed to a stationary shaft 292 of the second cooling mechanism 241, and the connecting member 293 is pivotable around the stationary shaft 292. In addition, another end portion of the connecting member 293 is fixed to a stationary shaft 294 of the third cooling mechanism 242, and the connecting member 293 is pivotable around the stationary shaft 294.
As shown in
In a case where the center-to-center distance L1 between the first cooling mechanism 240 and the second cooling mechanism 241 or the center-to-center distance L2 between the second cooling mechanism 241 and the third cooling mechanism 242 is not maintained constant, the collision position and the collision angle where the second cooling medium 55 collides with the steel material 10 are not constant. Consequently, there is a possibility that the second cooling medium 55 may not be properly ejected to a certain portion on the surface of the steel material 10. Therefore, there is a possibility that the insufficient quenching may appear on the steel material 10.
On the other hand, according to the present embodiment, the center-to-center distance L1 between the first cooling mechanism 240 and the second cooling mechanism 241 and the center-to-center distance L2 between the second cooling mechanism 241 and the third cooling mechanism 242 are maintained constant. Accordingly, the collision position and the collision angle where the second cooling medium 55 collides with the steel material 10 are maintained constant.
In addition, according to the present embodiment, even in a case where the steel material 10 is formed in a complicated shape, the second cooling medium 55 can be ejected to the circumferential surface of the outer side of the steel material 10.
For the above-described reason, according to the present embodiment, it is possible to reliably cool the outer side of the bent portion 11 which is less likely to be cooled in the related art. Therefore, it is possible to reduce the insufficient quenching when bending the steel material 10.
In addition, according to the present embodiment, the above-described secondary cooling can be realized without a need to provide a complicated drive mechanism.
In the second cooling medium 55 ejected from the first cooling mechanism 240 after cooling the steel material 10, the temperature of the second cooling medium 55 rises. Therefore, when the steel material 10 is cooled by the second cooling medium 55 ejected from the second cooling mechanism 241, if the second cooling medium 55 ejected from the first cooling mechanism 240 after cooling the steel material 10 is present, the steel material 10 cannot be effectively cooled.
However, the contact member 280 disposed in the second cooling mechanism 241 has a function to drain the second cooling medium 55 ejected from the first cooling mechanism 240. That is, the second cooling medium 55 ejected from the second cooling mechanism 241 can cool the steel material 10 without interfering with the second cooling medium 55 ejected from the first cooling mechanism 240. Therefore, according to the present embodiment, the steel material 10 can be effectively cooled by the second cooling medium 55 ejected from the second cooling mechanism 241.
Similarly, the contact member 280 of the third cooling mechanism 242 also has a function to drain the second cooling medium 55 ejected from the second cooling mechanism 241. That is, the second cooling medium 55 ejected from the third cooling mechanism 242 can cool the steel material 10 without interfering with the second cooling medium 55 ejected from the second cooling mechanism 241. Therefore, according to the present embodiment, the steel material 10 can be effectively cooled by the second cooling medium 55 ejected from the third cooling mechanism 242.
Therefore, according to the present embodiment, the secondary cooling of the steel material 10 can be effectively performed by the second cooling apparatus 223.
In the present embodiment, a mechanism in which each arrangement interval between the respective cooling mechanisms adjacent to each other is maintained constant and the arrangement of the respective cooling mechanisms is caused to follow a bent shape of the steel material 10 is referred to as a moving mechanism. In the second cooling apparatus 223 shown in
Next, a cooling method for the steel material 10, which uses the second cooling apparatus 223 according to the present embodiment, will be described with reference to
In the cooling method for the steel material 10 according to the present embodiment, as shown in
In addition, in the cooling method for the steel material 10 according to the present embodiment, as shown in
According to the cooling method for the steel material 10 in the present embodiment, when the second cooling media 55 are ejected to the plurality of locations along the feeding direction, each ejection interval in the feeding direction is maintained constant. The arrangement of the collision position where the second cooling medium 55 collides with the steel material 10 is caused to follow the predetermined shape of the steel material 10. Therefore, it is possible to reduce the insufficient quenching of the steel material 10.
Next, Modification Example 1 of the second embodiment will be described with reference to
In the above-described second cooling apparatus 223, the contact member 280 and the connecting members 290 to 293 are disposed as the moving mechanism. However, the configuration of the moving mechanism is not limited thereto.
As shown in
Similarly, the third cooling mechanism 242 has a drive unit 297 internally equipped with a motor, for example. The drive unit 297 is attached to a guide (guide portion) 298 which extends concentrically with the center of the first cooling mechanism 240. In accordance with the predetermined shape which is scheduled to apply to the steel material 10, the drive unit 297 moves the header 255 of the third cooling mechanism 242 along the guide 298. That is, the guide 298 regulates a moving direction of the third cooling mechanism 242.
According to the present modification example, in accordance with the predetermined shape which is scheduled to apply to the steel material 10, the drive unit 295 moves the header 255 of the second cooling mechanism 241 along the guide 296. In accordance with the predetermined shape which is scheduled to apply to the steel material 10, the drive unit 297 moves the header 255 of the third cooling mechanism 242 along the guide 298. In this manner, the collision position and the collision angle where the second cooling medium 55 ejected from the header 255 of the second cooling mechanism 241 and the header 255 of the third cooling mechanism 242 collides with the steel material 10 can be maintained constant.
For the above-described reason, according to present modification example, similarly to the second embodiment, it is possible to reliably cool the outer side of the bent portion 11 which is less likely to be cooled in the related art. Therefore, it is possible to reduce the insufficient quenching when bending the steel material 10.
In Modification Example 1 of the second embodiment, the drive units 295 and 297 and the guides 296 and 298 constitute the moving mechanism. The moving mechanism which is constituted by the drive units 295 and 297 and the guides 296 and 298 moves the second cooling apparatus 223 in accordance with a bent shape of the steel material 10 which is programmed. Therefore, the moving mechanism is an active moving mechanism.
The guides 296 and 298 are not limited to a rail-shaped guide, and can adopt various configurations. For example, the guide may guide the second cooling mechanism 241 and the third cooling mechanism 242 by vertically suspending both of these from above.
In addition, in the present modification example, the guides 296 and 298 may be omitted, and the drive units 295 and 297 may be controlled so that the center-to-center distances L1 and L2 are respectively constant in accordance with the bent shape of the steel material 10 which is programmed. However, in order to reliably maintain the center-to-center distances L1 and L2 to be constant, it is preferable to provide the guides 296 and 298.
Next, Modification Example 2 of the second embodiment will be described with reference to
As the moving mechanism, the second cooling apparatus 223 shown in
In the present modification example, the header 255 of the second cooling mechanism 241 is movable along the guide 296 by a sliding member 295′. Similarly, the header 255 of the third cooling mechanism 242 is movable along the guide 298 by a sliding member 297′.
In addition, in the present modification example, the second cooling mechanism 241 and the third cooling mechanism 242 include the contact member 280. Accordingly, the header 255 of the second cooling mechanism 241 and the header 255 of the third cooling mechanism 242 move to follow the movement of the steel material 10.
In this manner, even in a case where complicated bending is performed to the steel material 10, the collision position and the collision angle where the second cooling medium 55 ejected from the header 255 of the second cooling mechanism 241 and the header 255 of the third cooling mechanism 242 collides with the steel material 10 can be maintained constant. Therefore, without depending on a bent shape of the steel material 10, the second cooling medium 55 can be ejected to the circumferential surface of the outer side of the bent portion 11 of the steel material 10. Accordingly, it is possible to reduce the insufficient quenching when the bending for the steel material 10.
The moving mechanism according to the present modification example moves the second cooling apparatus 223 in association with the movement of the steel material 10. Accordingly, the moving mechanism is a passive moving mechanism.
Next, the cooling apparatus for the steel material 10 according to a third embodiment will be described with reference to
As shown in
As shown in
The respective headers 350 to 353 have a spray nozzle 354. For example, as the spray nozzle 354, a flat nozzle, a full cone nozzle, or an oval nozzle is used. Without being limited to the number shown in
As shown in
In addition, as shown in
Since the second cooling apparatus 323 includes the second draining mechanism 320, the second cooling medium 55 ejected from the first cooling mechanism 40 is drained by the draining water ejected from the second draining mechanism 320. Thus, the second cooling medium 55 does not flow to the downstream side. Therefore, without receiving the influence of the second cooling medium 55 ejected from the first cooling mechanism 40, the second cooling medium 55 ejected from the second cooling mechanism 41 can collide with the steel material 10. Accordingly, since the second cooling apparatus 323 includes the second draining mechanism 320, the second cooling mechanism 41 can effectively perform the secondary cooling on the steel material 10.
The second cooling medium 55 ejected from the second cooling mechanism 41 is drained by the draining water ejected from the third draining mechanism 321. Therefore, it is possible to prevent that the second cooling medium 55 ejected from the second cooling mechanism 41 from being scattered beyond the steel material 10.
The second draining mechanism 320 and the third draining mechanism 321 have the same configuration as that of the first draining mechanism 300.
Next, a cooling method for the steel material 10 according to a third embodiment will be described with reference to
(First Draining Process)
The cooling method for the steel material 10 according to the present embodiment has a first draining process of draining the first cooling medium 35 ejected toward the downstream side, at the upstream position from the collision position where the second cooling medium 55 ejected from the first cooling mechanism 40 located at the most upstream position in the second cooling apparatus 23 collides with the steel material 10.
Since the cooling method for the steel material 10 according to the present embodiment has the first draining process. The second cooling medium 55 ejected from the first cooling mechanism 40 can collide with the steel material 10 without receiving the influence of the first cooling medium 35 ejected from the first cooling apparatus 22. Therefore, the first cooling mechanism 40 can effectively perform the secondary cooling to the steel material 10.
(Second Draining Process)
The cooling method for the steel material 10 according to the present embodiment may further have a plurality of second draining processes of draining the second cooling medium 55 flowing toward the downstream side, at the downstream position from the collision position where one of the second cooling media 55 collides with the steel material 10.
Since the cooling method for the steel material 10 according to the present embodiment has the plurality of second draining processes, the second cooling medium 55 ejected from the second cooling mechanism 41 can collide with the steel material 10 without receiving the influence of the second cooling medium 55 ejected from the first cooling mechanism 40. In addition, since the cooling method for the steel material 10 according to the present embodiment has the plurality of second draining processes, it is possible to drain the second cooling medium 55 ejected from the second cooling mechanism 41. Therefore, the second cooling medium 55 can be prevented from being scattered beyond the steel material 10.
Accordingly, since the cooling method for the steel material 10 according to the present embodiment has the second draining process, the second cooling mechanism 41 can effectively perform the secondary cooling on the steel material 10.
Next, the cooling apparatus for the steel material 10 according to a fourth embodiment will be described with reference to
In a second cooling apparatus 423 according to the present embodiment, the second cooling medium 55 ejected from the first cooling mechanism 40 and the second cooling mechanism 41 is controlled by a control unit 400 shown in
The control unit 400 controls the second cooling medium 55 so that the flow velocity of the second cooling medium 55 is 2 to 30 m/sec and the water amount density is 5 to 100 m3/m2/min. Through the cooling using the second cooling medium 55, the steel material 10 is cooled to below the martensitic transformation finish temperature Mf, or to approximately room temperature, for example. Specifically, the steel material 10 is cooled to the room temperature to 300° C., for example.
In the present embodiment, the water amount density (m3/m2/min) represents a water amount per unit area and unit time on a cooled material's surface serving as a region with which cooling water collides.
Hitherto, a case has been described where the control unit 400 is disposed in the second cooling apparatus 423. However, the control unit 400 may be disposed in the first cooling apparatus 22, and the control unit 400 may control the first cooling medium 35 ejected from the first cooling apparatus 22. In a case where the control unit 400 controls the first cooling medium 35, the control unit 400 controls the first cooling medium 35 so that the flow velocity of the first cooling medium 35 is 2 to 8 m/sec and the water amount density is 20 to 80 m3/m2/min.
Since the control unit 400 controls the second cooling medium 55 as described above, the second cooling medium 55 ejected from the first cooling mechanism 40 can drain the first cooling medium 35 ejected from the first cooling apparatus 22.
In order to efficiently cool the steel material 10, that is, in order to increase a heat transfer amount to the steel material 10, it is generally necessary to reduce a thickness of a temperature boundary layer. In the present embodiment, the second cooling medium 55 ejected from the first cooling mechanism 40 drains the first cooling medium 35. Accordingly, it is possible to prevent the first cooling medium 35 whose temperature rises from flowing to the downstream side. In this manner, it is possible to prevent the temperature boundary layer from growing in the second cooling medium 55 ejected from the first cooling mechanism 40. Therefore, it is possible to effectively cool the steel material 10.
In addition, since the control unit 400 controls the second cooling medium 55 as described above, the second cooling medium 55 ejected from the second cooling mechanism 41 can drain the second cooling medium 55 ejected from the first cooling mechanism 40. In this manner, for the reason similar to the above-described reason, it is possible to prevent the temperature boundary layer from growing in the second cooling medium 55 ejected from the second cooling mechanism 41. Therefore, the steel material 10 can be more effectively cooled.
In order to stably and efficiently cool the steel material 10 in a nuclear boiling region during the secondary cooling, it is necessary to ensure the water amount density of the second cooling medium 55. From a viewpoint of ensuring the water amount density, a lower limit value of the flow velocity of the second cooling medium 55 is set to 2 m/sec.
On the other hand, an upper limit value of the flow velocity of the second cooling medium 55 is not particularly limited from a viewpoint that the first cooling medium 35 is drained and the secondary cooling is properly performed on the steel material 10. However, from a viewpoint of maintenance and economic feasibility of the second cooling apparatus 23, it is preferable that the water amount of the second cooling medium 55 is reduced as much as possible, and it is preferable that the flow velocity of the second cooling medium 55 is as slow as possible. Therefore, the upper limit value of the flow velocity of the second cooling medium 55 is set to 30 m/sec.
In the present embodiment, the flow velocity of the second cooling medium 55 indicates a flow velocity at an exit of the spray nozzles 54 and 64.
Next, a cooling method for the steel material 10 according to a fourth embodiment will be described with reference to
As shown in
The second cooling medium 55 ejected from the spray nozzle 54 of the upper header 50 of the first cooling mechanism 40 collides with the steel material 10 at a collision angle θ4. As shown in
A second cooling medium 55a as a portion of the second cooling medium 55 ejected to the steel material 10 from the spray nozzle 54 flows to the upstream side so as to drain the first cooling medium 35, and the remaining second cooling medium 55b flows to the downstream side so as to be used in performing the secondary cooling on the steel material 10. According to the cooling method, the first cooling medium 35 is drained. Therefore, the second cooling medium 55b to be used in performing the secondary cooling does not receive the influence of the first cooling medium 35, and the secondary cooling can be properly performed on the steel material 10.
The second cooling medium 55a is used in draining the first cooling medium 35, and is discharged laterally from the steel material 10 together with the first cooling medium 35. Accordingly, the second cooling medium 55a does not flow to the upstream side (heating apparatus 21 side).
The second cooling medium 55 ejected from the spray nozzle 64 of the upper header 60 of the second cooling mechanism 41 collides with the steel material 10 at a collision angle θ5. The second cooling medium 55a as a portion of the second cooling medium 55 ejected to the steel material 10 from the spray nozzle 64 flows to the upstream side, and drains the second cooling medium 55b ejected from the spray nozzle 54. The remaining second cooling medium 55b flows to the downstream side, and is used in performing the secondary cooling on the steel material 10. According to the cooling method, the second cooling medium 55b whose temperature rises can be prevented from flowing to the downstream side. Therefore, it is possible to efficiently perform the secondary cooling on the steel material 10 using the second cooling medium 55.
In the present embodiment, the flow velocity of the second cooling medium 55 is controlled to be 2 to 30 m/sec. Accordingly, the second cooling medium 55a as a portion of the second cooling medium 55 ejected to the steel material 10 flows to the upstream side, and drains the first cooling medium 35. The remaining second cooling medium 55b is used in performing the secondary cooling on the steel material 10.
Accordingly, without receiving the influence of the first cooling medium 35, the second cooling medium 55b can cool the steel material 10. Therefore, the second cooling medium 55b can be ejected to the outer circumferential surface of the outer side of the bent portion 11 of the steel material 10. In this manner, it is possible to reduce the insufficient quenching on the steel material 10, and it is possible to bend the steel material 10 properly. Moreover, the second cooling medium 55 is provided with a function to drain the first cooling medium 35 and a function to perform the secondary cooling on the steel material 10. Therefore, a mechanism for draining the first cooling medium 35 is not needed, thereby leading to economically excellent effect.
Even in a case where the lower surface of the steel material 10 is cooled, the same cooling method is used. That is, even when the lower surface of the steel material 10 is cooled, the flow velocity of the second cooling medium 55 ejected from the spray nozzle 54 of the lower header 51 of the first cooling mechanism 40 and the spray nozzle 64 of the lower header 61 of the second cooling mechanism 41 is set to 2 to 30 msec. In this manner, the second cooling medium 55 can properly cool the lower surface of the steel material 10. It is preferable that the flow velocity of the second cooling medium 55 ejected from the spray nozzle 54 of the lateral headers 52 and 53 of the first cooling mechanism 40 and the spray nozzle 64 of the lateral headers 62 and 63 of the second cooling mechanism 41 is set to 2 to 30 m/sec similarly to the second cooling medium 55 ejected from the upper headers 50 and 60 and the lower headers 51 and 61.
In accordance with a cooled state of the steel material 10, the control unit 400 may control not only the flow velocity of the second cooling medium 55, but also the water amount density of the second cooling medium 55 or the collision angle between the second cooling medium 55 and the steel material 10. Since the control unit 400 can control the water amount density of the second cooling medium 55 or the collision angle between the second cooling medium 55 and the steel material 10, even in a case where complicated bending is performed to the steel material 10, the steel material 10 can be cooled without causing the insufficient quenching.
Next, Modification Example 1 of the fourth embodiment will be described with reference to
As shown in
Although not shown, the moving mechanism 470 disposed in the second cooling mechanism 41 has the same configuration as that of the moving mechanism 470 disposed in the first cooling mechanism 40.
Here, for example, in a case of using the cooling method for the steel material 200 in the related art disclosed in Patent Document 1, that is, in a case where the cooling apparatus 210 cools the heat-processed steel material 200 as shown in
On the other hand, the moving mechanism 470 according to the present embodiment can move the spray nozzles 54 and 64 disposed in the headers 50 to 53 and 60 to 63 so as to follow the movement of the steel material 10 formed in a predetermined shape including the bent portion 11 by the bending apparatus 24. Therefore, even if the steel material 10 is processed into a complicated shape, the second cooling medium 55 can be ejected to the circumferential surface of the outer side of the bent portion 11 of the steel material 10. As a result, it is possible to properly cool the circumferential surface of the outer side of the bent portion 11. Accordingly, it is possible to reduce the insufficient quenching on the steel material 10.
Furthermore, the spray nozzles 54 and 64 can be moved by the moving mechanism 470. Accordingly, it is possible to adjust a collision angle at which the second cooling medium 55 ejected from the spray nozzles 54 and 64 collides with the steel material 10.
The collision angle between the second cooling medium 55 and the steel material 10 is adjusted to 45 degrees or smaller. In this manner, it is possible to prevent the second cooling medium 55 colliding with the steel material 10 from returning to the upper headers 50 and 60 side or the lower headers 51 and 61 side. In addition, since the collision angle between the second cooling medium 55 and the steel material 10 is adjusted, the momentum of the second cooling medium 55 in the feeding direction of the steel material 10 can be greater than the momentum of the first cooling medium 35 in the feeding direction of the steel material 10.
Therefore, since the second cooling apparatus 423 includes the moving mechanism 470, the secondary cooling can be more effectively performed on the steel material 10.
In addition, in the embodiment shown in
On the other hand, according to the present modification example, as shown in
In
Furthermore, since the second cooling apparatus 423 includes the moving mechanism 470, the spray nozzle 54 disposed in the headers 50 to 53 can follow the movement of the steel material 10. Accordingly, the second cooling medium 55 ejected from the spray nozzle 54 can reliably collide with the steel material 10. Therefore, it is possible to reduce the water amount of the second cooling medium 55 needed to cool the steel material 10 to a predetermined temperature. In this manner, it is possible to improve maintenance service and economic feasibility of the second cooling apparatus 423.
Next, Modification Example 2 of the fourth embodiment will be described with reference to
As shown in
In order to perform the secondary cooling on the steel material 10 in a nuclear boiling region, it is generally necessary to agitate the second cooling medium 55 on the steel material 10 and to properly provide the second cooling medium 55 with latent heat from the steel material 10. In a case where the pulsation providing mechanism 480 provides the pulsation for the second cooling medium 55 ejected to the steel material 10, the second cooling medium 55 is agitated, and thus, the secondary cooling can be more reliably performed on the steel material 10 in the nuclear boiling region using the second cooling medium 55. Therefore, the secondary cooling can be more effectively performed on the steel material 10.
Next, the cooling apparatus for the steel material 10 according to a fifth embodiment will be described with reference to
As shown in
As shown in
It is preferable to dispose the spray nozzle 554 of the upper header 550 and the lower header 551 in a direction in which a collision angle θ6 at which the second cooling medium 55 ejected from the spray nozzle 554 collides with the steel material 10 is 60 degrees or smaller. When the collision angle θ6 is set to 60 degrees or smaller, it is possible to prevent the second cooling medium 55 colliding with the steel material 10 from reversely flowing and returning to the upper header 550 side or the lower header 551 side.
It is preferable to dispose the spray nozzle 554 of the respective headers 550 to 553 at a position where the second cooling media 55 ejected from the respective spray nozzles 554 do not cross each other until the second cooling medium 55 ejected from the spray nozzle 554 reaches the steel material 10.
Furthermore, in order to enable the second cooling medium 55 to properly cool the steel material 10 even in a case where bending is performed to the steel material 10 into a complicated shape, it is preferable that an ejection angle θ7 of the second cooling medium 55 ejected from the spray nozzle 54 of the upper header 550 and the lower header 551 and an ejection angle θ8 of the second cooling medium 55 ejected from the spray nozzle 54 of the lateral headers 552 and 553 are as wide as possible within a range in which the second cooling media 55 do not cross each other as described above.
However, considering maintenance service and economic feasibility of the second cooling apparatus 523, it is preferable that the ejection angles θ7 and θ8 are respectively set to approximately 30 to 90 degrees. Furthermore, in a case where a moving mechanism 570 is disposed in the second cooling apparatus 523 as will be described later, it is preferable that the ejection angles θ7 and θ8 are respectively set to approximately 30 to 50 degrees. However, in a case where a cooling surface of the steel material 10 is narrow, the ejection angles θ7 and θ8 may be 10 to 30 degrees.
The configuration of the first cooling mechanism 540 has been described with reference to
In addition, in the first cooling mechanism 540 and the second cooling mechanism 541, the second cooling medium 55 ejected from the respective spray nozzles 554 and 564 may be controlled by a control unit 500 shown in
In a case where the flow velocity of the second cooling medium 55 is controlled by the control unit 500, it is preferable to set the flow velocity to 2 to 15 m/sec.
For the reason the same as the above-described reason, the lower limit value of the flow velocity of the second cooling medium 55 ejected from the second cooling apparatus 523 according to the present embodiment is set to 2 m/sec. On the other hand, in a case where the flow velocity of the second cooling medium 55 is faster than 15 m/sec, the second cooling medium 55 may flow to the heating apparatus 21 in some cases. Therefore, in the present embodiment, the upper limit value of the flow velocity of the second cooling medium 55 is set to 15 m/sec.
As shown in
In addition, as shown in
As the moving mechanism 570 and the pulsation providing mechanism 580, it is possible to employ those which have the same configuration as that according to the fourth embodiment.
Next, a cooling method for the steel material 10 according to the fifth embodiment will be described with reference to
The first cooling medium 35 ejected from the first cooling apparatus 22 collides with the steel material 10 at the collision angle Ø1. After being used in performing the primary cooling on the steel material 10, the first cooling medium 35 flows toward the downstream side.
The second cooling medium 55 ejected from the spray nozzle 554 of the upper header 550 of the first cooling mechanism 540 collides with the steel material 10 at a collision angle θ6. The second cooling medium 55a as a portion of the second cooling medium 55 ejected to the steel material 10 from the spray nozzle 554 flows to the upstream side, and drains the first cooling medium 35. According to the cooling method, when the secondary cooling is performed, the first cooling medium 35 is drained. Accordingly, the second cooling medium 55b ejected from the spray nozzle 554 does not receive the influence of the first cooling medium 35, and the secondary cooling can be performed on the steel material 10. After being used in draining the first cooling medium 35, the second cooling medium 55a is discharged laterally from the steel material 10 together with the first cooling medium 35. Accordingly, the second cooling medium 55a does not flow to the heating apparatus 21 side on the upstream side.
The second cooling medium 55 ejected from the spray nozzle 564 of the upper header 560 of the second cooling mechanism 541 collides with the steel material 10 at a collision angle θ11. The second cooling medium 55a as a portion of the second cooling medium 55 ejected to the steel material 10 from the spray nozzle 564 flows to the upstream side, and drains the second cooling medium 55b. According to the cooling method, when the secondary cooling is performed, the second cooling medium 55b ejected from the spray nozzle 554 is drained. Accordingly, the second cooling medium 55b ejected from the spray nozzle 564 is not influenced by the second cooling medium 55b ejected from the spray nozzle 554, and the secondary cooling can be performed on the steel material 10.
According to the cooling method for the steel material 10 according to the present embodiment, for the above-described reason, it is possible to reduce the thickness of the temperature boundary layer of the second cooling medium 55. Therefore, it is possible to efficiently cool the steel material 10.
According to the present embodiment, the second cooling medium 55 is ejected toward the upstream side in the feeding direction. Accordingly, the second cooling medium 55a ejected to the steel material 10 from the spray nozzle 554 flows to the upstream side, and drains the first cooling medium 35. In addition, the second cooling medium 55a ejected to the steel material 10 from the spray nozzle 564 flows to the upstream side, and drains the second cooling medium 55b ejected from the spray nozzle 554.
Therefore, without receiving the influence of the first cooling medium 35 whose temperature rises and the second cooling medium 55b ejected from the spray nozzle 554, the second cooling medium 55 can be ejected to a protruding side circumferential surface of the bent portion 11 of the steel material 10. Therefore, it is possible to prevent the insufficient quenching on the steel material 10 when bending. As a result, it is possible to perform proper bending to the steel material 10.
In addition, the second cooling medium 55 is provided with both a function to drain the first cooling medium 35 and a function to perform the secondary cooling on the steel material 10. Therefore, it is possible to efficiently cool the steel material 10.
In the present embodiment, the momentum of the second cooling medium 55 in the feeding direction of the steel material 10 may be slightly greater than the momentum of the first cooling medium 35 in the feeding direction of the steel material 10. However, when the momentum of the second cooling medium 55 is two times or greater than the momentum of the first cooling medium 35, there is a possibility that the second cooling medium 55a may pass through the first cooling medium 35 and may flow to the heating apparatus 21 located on the upstream side. Accordingly, it is preferable that if the momentum of the second cooling medium 55 is approximately 1 to 1.5 times of the momentum of the first cooling medium 35.
Hitherto, referring to
It is preferable that the flow velocity of the second cooling medium 55 ejected from the spray nozzles 554 and 564 of the lateral headers 552, 553, 562, and 563 is limited to 2 to 15 msec similarly to the upper headers 550 and 560 and the lower headers 551 and 561.
Without being limited to the above-described embodiments, the present invention also includes modifications or combinations of configurations adopted within the scope not departing from the gist of the present invention. Furthermore, as a matter of course, the configurations described in the respective embodiments can be utilized in suitable combination with each other.
Hereinafter, content of the present invention will be described in more detail with reference to Examples and comparative examples. The present invention is not limited to the following Examples.
A surface temperature of a steel material at a feeding position of the steel material in a case of using the cooling apparatus for the steel material according to the first embodiment will be described with reference to
In Example 1-1 and Comparative Example 1-1, as the first cooling apparatus, the first cooling apparatus shown in
In Example 1-1, the following conditions are used.
The water amount of the first cooling medium is set to 110 L/min, and the flow velocity is set to 4 m/sec.
The water amount of the second cooling medium ejected from the upper header of the first cooling mechanism is set to 50 L/min. The flow velocity is set to 12 m/sec. The water amount of the second cooling medium ejected from the lower header is set to 50 L/min. The flow velocity is set to 12 m/sec. The water amount of the second cooling medium ejected from the lateral header is set to 18 L/min. The flow velocity is set to 10 m/sec. The water amount of the second cooling medium ejected from the upper header of the second cooling mechanism is set to 75 L/min. The flow velocity is set to 12 m/sec. The water amount of the second cooling medium ejected from the lower header is set to 75 L/min. The flow velocity is set to 12 m/sec. The water amount of the second cooling medium ejected from the lateral header is set to 20 L/min. The flow velocity is set to 10 msec. The first cooling medium is a columnar jet, and the water amount density is 40 m3/m2/min.
In the secondary cooling, a flat spray nozzle is used as the nozzle of the header. As a spread angle of the upper header and the lower header, the spread angle (ejection angle) of the second cooling medium ejected from the nozzle is set to 50 degrees, and the water amount density is set to 80 m3/m2/min. In the lateral header, in order to eject the second cooling medium to a flat side surface, the above-described spray spread angle is set to 10 degrees, and the water amount density is set to 40 m3/m2/min.
Any momentum of the second cooling medium is 1.5 times or greater than that of the first cooling medium.
In Comparative Example 1-1, the following conditions are used. As described above, the first cooling apparatus used in Comparative Example 1-1 is the same as the first cooling apparatus used in Example 1-1. As the conditions relating to the first cooling medium in Comparative Example 1-1, the same conditions as those relating to the first cooling medium in Example 1-1 are also used.
The water amount of the second cooling medium is set to 200 L/min. The flow velocity of the second cooling medium is set to 4 m/sec. The water amount density of the second cooling medium is set to 12 m3/m2/min. In addition, an ejection form of the second cooling medium is set to a columnar jet.
The momentum of the second cooling medium in the feeding direction of the steel material is 1 times the momentum of the first cooling medium in the feeding direction of the steel material.
Based on the above-described conditions, bending is performed to the steel material. In
If
Therefore, according to the present invention, it is possible to uniformly cool the inside and the outside of the bent portion of the steel material. Accordingly, it is found that an insufficient quenching which is a problem in the related art can be prevented.
Residual stress in a case of using the cooling apparatus for the steel material according to the first embodiment will be described with reference to
The first cooling apparatus used in Example 2-1, Example 2-2, and Comparative Example 2-1 is the same as the first cooling apparatus used in Example 1-1 and Comparative Example 1-1. In addition, the second cooling apparatus used in Example 2-1 and Example 2-2 is the same as the second cooling apparatus used in Example 1-1. More, the second cooling apparatus used in Comparative Example 2-1 is the same as the second cooling apparatus used in Comparative Example 1-1.
As the conditions of Example 2-1, the same conditions as those of Example 1-1 are used except that the water amount of the second cooling medium ejected from the lateral header of the second cooling mechanism is set to 18 L/min.
The conditions of Example 2-2 are as follows.
The water amount of the first cooling medium is set to 110 L/min. The flow velocity of the first cooling medium is set to 3 m/sec. The water amount density of the first cooling medium is set to 40 m3/m2/min. The ejection form of the first cooling medium is set to a columnar jet.
With regard to the second cooling medium ejected from the upper header and the lower header of the first cooling mechanism, the water amount is set to 60 L/min, and the flow velocity is set to 14 m/sec. With regard to the second cooling medium ejected from the lateral header of the first cooling mechanism, the water amount is set to 23 L/min, and the flow velocity is set to 12 m/sec.
With regard to the second cooling medium ejected from the upper header and the lower header of the second cooling mechanism, the water amount is set to 90 L/min, and the flow velocity is set to 14 m/sec. With regard to the second cooling medium ejected from the lateral header of the second cooling mechanism, the water amount is set to 23 L/min, and the flow velocity is set to 12 m/sec.
As the nozzle of the header of the first cooling mechanism and the second cooling mechanism, a long-radius spray nozzle is used.
With regard to the second cooling medium ejected from the upper header and the lower header of the first cooling mechanism and the second cooling mechanism, the spread angle (ejection angle) is set to 50 degrees, and the water amount density is set to 25 m3/m2/min.
With regard to the second cooling medium ejected from the lateral header of the first cooling mechanism and the second cooling mechanism, the spread angle (ejection angle) is set to 10 degrees, and the water amount density is set to 28 m3/m2/min.
The momentum of the second cooling medium in the feeding direction of the steel material is 1.5 times or greater than the momentum of the first cooling medium in the feeding direction of the steel material.
In Comparative Example 2-1, the same conditions as those of Comparative Example 1-1 are used.
Bending is performed to the steel material under the above-described conditions.
Referring to
A surface temperature of the steel material at the feeding position of the steel material in a case of using the cooling apparatus for the steel material according to the fifth embodiment will be described with reference to
In Example 3-1, the first cooling apparatus shown in
In Example 3-1, the same conditions as those of Example 1-1 are used except that the second cooling apparatus shown in
The horizontal axis in
As shown in
According to the above-described respective embodiments, it is possible to provide a cooling apparatus and a cooling method for a steel material, which can reduce an insufficient quenching of the steel material.
1: Bending Device
10, 200: Steel Material
11: Bend (Bent Portion)
20: Feeding Apparatus
21: Heating Apparatus
22: First Cooling Apparatus (Primary Cooling Apparatus)
23, 223, 323, 423, 523: Second Cooling Apparatus (Secondary Cooling Apparatus)
24: Bending Apparatus
25: Clamp
26: Drive Arm
35: First Cooling Medium
40, 240, 540: First Cooling Mechanism
41, 241, 541: Second Cooling Mechanism
55: Second Cooling Medium
280, 281: Contact Member (Contact Portion)
290, 293: Connecting Member (Connecting Portion)
295, 297, 495: Drive Unit
296, 298: Guide (The Guide Portion)
300: First Draining Mechanism
320: Second Draining Mechanism
321: Third Draining Mechanism
400, 500: Control Unit
480, 580: Pulsation Providing Mechanism
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014-206255 | Oct 2014 | JP | national |
| 2014-206256 | Oct 2014 | JP | national |
| 2014-211900 | Oct 2014 | JP | national |
| 2014-211903 | Oct 2014 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2015/078240 | 10/5/2015 | WO | 00 |
