This application claims priority from Japanese Patent Application No. 2021-178531 filed on Nov. 1, 2021 and Japanese Patent Application No. 2021-114632 filed on Jul. 19, 2022. The content of this application is incorporated herein by reference in their entirety.
The present invention relates to a die block device used in an extrusion press machine.
An extrusion press machine is a device for manufacturing aluminum products by pressing an easily workable metal material such as aluminum or its alloys (hereinafter referred to as aluminum material) through a die and continuously extruding an aluminum product having a predetermined cross-sectional shape through the die (extrusion). The die has an opening with a cross-sectional shape similar to that of the aluminum product. An extruded long aluminum product is cut into individual aluminum products having a predetermined length.
With reference to
A main cylinder 4 that creates extrusion pressure constitutes a hydraulic cylinder having only an oil chamber for moving a cylinder rod forward, and a main ram 4A corresponds to the cylinder rod. An extrusion stem 3 is mounted to the main ram 4A. Hydraulic oil supplied from a main pump unit 5 through a hydraulic circuit to the oil chamber in the main cylinder 4 moves a position of the main ram 4A (ram position) toward the die 2 (forward/to the right side in
Although not shown in
As disclosed in JP 10-085830 A, a die block may include a plurality of heating means arranged in parallel with an extrusion direction. This is for preventing defective dimension accuracy or shape of an extruded product by heating and keeping a peripheral surface of the die 2 at a desired temperature for a billet preheated to about 400° C. for extrusion.
However, continuing the extrusion process causes a rise in temperature of the die due to friction between an inner peripheral surface of the part of the die that has an opening with a cross-sectional shape similar to that of the extruded product and is provided for extrusion, and the extruded product being extruded. The rise in temperature of the die may reduce quality of the extruded product. On the other hand, if a cooling mechanism is to be arranged in the die block to suppress the rise in temperature of the die, the die block is moved by the die slide mechanism between the extrusion operation position (operation position) and the die changing position (changing position), and thus the cooling mechanism also needs to be moved, which complicates piping of the cooling mechanism.
The present invention is achieved in view of the above described problems, and has an object to provide a die block device in an extruder including a cooling mechanism of a simple structure reciprocable between the extrusion operation position and the die changing position.
The die block device according to the present invention includes: a die block portion configured to reciprocate between an operation position for extrusion and a changing position for die changing; and a gas supply portion configured to supply a cooling gas toward the die block portion.
The die block portion includes a block body having a support surface that supports the die, and a gas channel having a supply port for the cooling gas and an exhaust port that extends from the supply port through the block body and opens into the support surface.
The gas supply portion includes a supply passage provided to communicate with the gas channel through the supply port when the die block portion is in the operation position.
The die block portion in the present invention may include a plurality of gas channels, and the gas supply portion may include the supply passage communicating with each of the plurality of gas channels.
The support surface in the present invention may have an arcuate surface when viewed from front, and may have the exhaust port of the gas channel, the exhaust port opening within a range of ±30° in a height direction with reference to a center of curvature of the arcuate surface.
The block body in the present invention may hold the die including a small diameter part provided for extrusion and a large diameter part continuous with the small diameter part, and the block body may include a small diameter support part that supports the small diameter part of the die, and a large diameter support part that supports the large diameter part of the die.
The gas channel is provided in one or both of the small diameter support part and the large diameter support part.
The block body in the present invention preferably has a temperature sensor incorporated therein, and when a detected temperature of the block body by the temperature sensor exceeds a previously set temperature, the cooling gas is supplied to the supply passage.
The block body in the present invention preferably has a heater incorporated therein, and when the detected temperature exceeds the previously set temperature, a heating set temperature by the heater is reduced, and the detected temperature is further monitored for a previously set time. When the detected temperature exceeds the set temperature, the cooling gas is supplied to the supply passage until the detected temperature falls below the set temperature.
In the die block device according to the present invention, the gas channel is provided in the die block portion configured to reciprocate between the operation position and the changing position, and when the die block portion is in the operation position, the supply passage in the gas supply portion communicates with the gas channel. Then, when the die block portion is moved from the operation position to the changing position, the communication between the gas channel and the supply passage is released. As such, the gas supply portion is positionally fixed independently of the position of the die block portion. Thus, even if the gas supply portion includes other components in the supply passage such as an open/close switching valve or a stop valve, such components need not be moved according to the movement of the die block portion. Thus, even if the die block device according to the present invention includes a cooling mechanism configured to cool the die, the cooling mechanism is not complicated.
Now, embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are not intended to limit the invention according to claims, and not all of combinations of features described in the embodiments are essential to the solution of the invention.
With reference to
As shown in
As shown in
The die block body 21 includes a small diameter support part 21A that supports a small diameter part 2A of the die 2, and a large diameter support part 21B that supports a large diameter part 2B of the die 2. As shown in
The small diameter support part 21A and the large diameter support part 21B of the die block body 21 include a small diameter support surface 21C and a large diameter support surface 21D that support the small diameter part 2A and the large diameter part 2B, respectively, of the die 2. The small diameter support surface 21C and the large diameter support surface 21D are arcuate surfaces when viewed from front. A region surrounded by the arcuate surfaces is an accommodation space 21S for the die 2. The small diameter support surface 21C has a smaller radius of curvature than the large diameter support surface 21D. When the die block body 21 holds the die 2, the small diameter part 2A comes into contact with the small diameter support surface 21C, and the large diameter part 2B comes into contact with the large diameter support surface 21D, with a clearance through which the cooling gas CG flows between the die block body 21 and the die 2.
The small diameter support surface 21C and the large diameter support surface 21D each include a lower support surface 21E and a pair of side support surfaces 21F, 21F continuous with the lower support surface 21E. The side support surfaces 21F, 21F are provided opposite each other on opposite sides of the accommodation space 21S in the width direction Y. As described below in detail, the gas channels 24A, 24B are provided correspondingly to the lower support surface 21E.
The die block portion 20 can reciprocate with a slide device (not shown) between an operation position P1 (
As shown in
The heater 22 may be various devices capable of heating an object, such as a rod-like ceramic heater or a wire heater. The heater 22 is provided such that its length direction is along the extrusion direction X. In this embodiment, a plurality of heaters 22 are arranged to surround the small diameter support surface 21C and the large diameter support surface 21D each having the arcuate shape of the die block body 21. In this embodiment, no heater 22 is provided between the gas channels 24A, 24B. However, a heater 22 may be provided between the gas channels 24A, 24B depending on arrangement of the gas channels.
The temperature sensor 23 may be various devices capable of measuring a temperature, such as a thermocouple, a thermistor, a platinum resistance temperature detector, or a bimetallic thermometer. A plurality of temperature sensors 23 are also provided as an example, and temperature sensors 23A, 23B are provided on opposite sides in the width direction Y near upper ends of the small diameter support surface 21C and the large diameter support surface 21D, and a temperature sensor 23C is provided near lower ends of the small diameter support surface 21C and the large diameter support surface 21D.
As shown in
In this embodiment, the pair of gas channels 24A, 24B are provided symmetrically with respect to a line segment CL (see
As the die block body 21 reciprocates in the width direction Y, the positions of the gas channels 24 move. The gas channels 24 as the gaps formed by perforating the small diameter support part 21A has been described herein, but the gas channels 24 may be formed of pipes.
In
Next, the gas supply portion 40 configured to supply the cooling gas CG toward the die block portion 20 will be described.
The gas supply portion 40 includes a supply passage 41 (41A, 41B) configured to supply the cooling gas CG toward the gas channels 24, an open/close switching valve 43 and a stop valve 45 arranged in the supply passage 41, and a gas supply source 47 that stores the cooling gas CG to be supplied to the supply passage 41. The supply passage 41 is connected to the gas supply source 47 at an upstream end of the flow of the cooling gas CG. The supply passage 41 branches to the supply passage 41A and the supply passage 41B downstream of the open/close switching valve 43.
While the die block portion 20 is moving between the operation position P1 and the changing position P2, the gas supply portion 40 remains in a fixed position. The supply passage 41A corresponds to the gas channel 24A, and the supply passage 41B corresponds to the gas channel 24B. As shown in
Although not shown, in communicating parts between the gas channels 24A, 24B and the supply passage 41, packing or the like is preferably provided in an opening of each communicating part on the side of the die block portion 20 or the side of the lower gib 33, thereby suppressing leakage of the cooling gas CG through the communicating parts between the gas channels 24A, 24B and the supply passage 41.
The example of the pair of gas channels 24A, 24B being provided has been described. However, as shown in the upper section in
The die block device 10 includes a controller 50 configured to control operation of the die block device 10.
In an extrusion process, the controller 50 performs heating control of the die 2 with the heater 22 and cooling control of the die 2 with the cooling gas CG. The controller 50 can also control the reciprocation of the die block portion 20.
The controller 50 stores previously set heating and heat retaining patterns of the die 2 for the heating control of the die 2. The controller 50 also stores information on a set temperature Ts relating to an upper limit of detected temperatures and a previously set time Ss used in a second control mode. The controller 50 can store other information required for operation of the die block device 10.
The controller 50 continuously obtains information on detected temperatures Td (TdA, TdB, TdC) by the temperature sensors 23A, 23B, 23C and compares the detected temperatures Td with the set temperature Ts. Based on a result of the comparison of the detected temperatures Td with the set temperature Ts, the controller 50 operates the gas supply portion 40 to supply the cooling gas CG from the supply passage 41 to the gas channel 24.
The controller 50 also compares an elapsed time Sd with the set time Ss for suppressing heating of the heater 22. Based on a result of the comparison of the elapsed time Sd with the set time Ss, the controller 50 can operate the gas supply portion 40 to supply the cooling gas CG from the supply passage 41 to the gas channel 24.
The controller can include a display device such as an LCD (liquid crystal display) for displaying the above results of comparisons.
Next, with reference to
When the extrusion process starts, the controller 50 operates the heater 22 to control temperatures of the lower area α and the side areas β of the die block body 21 based on the previously set heating and heat retaining patterns of the die 2 with reference to the detected temperatures Td by the temperature sensors 23 (S101 in
When the extrusion process continues, the billet B is pressed through the die 2, and an extruded product W is extruded through an opening having a cross-sectional shape similar to that of the extruded product W, and thus the die 2 is heated by friction with the extruded product W and rises in temperature. The temperature sensors 23A, 23B, 23C continuously detect the temperatures since the start of the extrusion process, and the detected temperatures TdA, TdB, TdC (Td) as detection results are transmitted to the controller 50. The controller 50 compares each of the obtained detected temperatures TdA, TdB, TdC with the previously stored set temperature Ts (S103).
When the controller 50 determines that any of the detected temperatures TdA, TdB, TdC (Td) exceeds the set temperature Ts (Yes in S103), the controller 50 operates the gas supply portion 40 and instructs the gas supply portion 40 to supply the cooling gas CG from the supply passages 41A, 41B to the gas channels 24A, 24B (S110).
Even after the instruction to supply the cooling gas CG, the controller 50 continuously obtains the detected temperatures TdA, TdB, TdC and compares the detected temperatures with the set temperature Ts. If any of the detected temperatures TdA, TdB, TdC exceeds the set temperature Ts, the controller 50 continues the instruction to supply the cooling gas CG (No in S111). If all of the detected temperatures TdA, TdB, TdC become equal to or lower than the set temperature Ts (Yes in S111), the controller 50 stops the instruction to supply the cooling gas CG (S113).
The controller 50 continues the above control until the end of the extrusion process.
Next, with reference to
If the controller 50 determines that any of the detected temperatures TdA, TdB, TdC (Td) exceeds the set temperature Ts (Yes in S103), the controller 50 instructs to suppress heating by the heater 22 incorporated in the die block body 21 in an area where the temperature higher than the set temperature is detected (S105 in
The controller 50 suppresses heating, and also monitors the detected temperature Td by the temperature sensor 23 in that area. Then, if the elapsed time Sd from the start of suppression of heating exceeds the previously set time Ss (Yes in S107), but the detected temperature Td by the temperature sensor 23 in that area does not fall below the set temperature Ts (No in S109), the controller 50 opens the open/close switching valve 43 in the supply passage 41 to eject the cooling gas CG toward the small diameter part 2A of the die 2 through the supply passage 41 and the gas channels 24A, 24B, thereby starting cooling of the die 2 (S110). The cooling is continued until all of the detected temperatures by the temperature sensors 23A to 23C fall below the set temperature (S111). Hereinafter, control is performed through the same steps as in the first control mode.
The two cooling control modes have been described above. However, the detected temperatures TdA, TdB, TdC (Td) by the temperature sensors 23 may be displayed on a display device of the controller 50, and an operator may check the display device. When any of the detected temperatures exceeds the set temperature, the operator may manually operate the gas supply portion 40 to supply the cooling gas CG from the supply passage 41 to the gas channel 24.
As described above, the gas channels 24A, 24B arranged in the die block body 21 communicate with the supply passage 41 of the gas supply portion 40 when the die block body 21 is in the operation position. Thus, even if the cooling mechanism configured to cool the die 2 accommodated in the die block body 21 is arranged in the die block body 21, piping of the cooling mechanism is not complicated.
Also, both the heating and heat retaining control and the cooling control of the die 2 accommodated in the block body 21 can be performed. This can prevent defective dimension accuracy or shape of an extruded product by heating and keeping a peripheral surface of the die 2 at a desired temperature.
In the first embodiment, assuming that an area near the small diameter part 2A of the die 2 is heated by friction with the extruded product W and most rises in temperature, the area can be cooled by ejecting the cooling gas CG. According to the first embodiment, an increase in cooling efficiency of the die 2 can be expected. A flow control valve may be provided in the supply passage 41 such that a supply amount of the cooling gas CG to be ejected is adjustable.
In the first embodiment, in the extrusion process, the small diameter part 2A of the die 2 is heated by friction with the extruded product W and most rises in temperature. However, depending on extrusion conditions or extruded products, areas other than the small diameter part 2A of the die 2, for example, a predetermined area of the large diameter part 2B of the die 2 may most rise in temperature. A second embodiment accommodates such a case.
As shown in
The first embodiment and the second embodiment have been described above. However, the present invention is not limited to the above embodiments, but may be embodied in various ways without departing from the contents of claims.
Number | Date | Country | Kind |
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2021-178531 | Nov 2021 | JP | national |
2022-114632 | Jul 2022 | JP | national |