This application is based on Japanese Patent Application No. 2005-348488 filed on Dec. 1, 2005, the disclosure of which is incorporated herein by reference.
The present invention relates to a heat exchanger having a positioning pin and a method of manufacturing the same.
It is known to provide a heat exchanger for a vehicle with positioning pins for positioning to a vehicle body. In a heat exchanger disclosed in Japanese Utility Model Laid-Open No. 6-74878, for example, headers are connected to both ends of flat tubes, and a cap is fixed to an end of each header tank. Further, a bracket having the positioning pin is fixed to the cap. In the heat exchanger, the flat tubes and corrugated fins are alternately laminated and brazed to each other. Also, the flat tubes and the header tanks are brazed to each other.
In such a construction, a bracket having a positioning pin is fitted to the end of a header tank to which a cap is fitted. Therefore, it is necessary to fix the cap and the bracket to the header tank, respectively and hence requires costs in terms of both of the number of parts and the number of assembling steps. Moreover, to fix the positioning pin to the bracket, the positioning pin is made to abut on the bracket and then is brazed to the bracket. Hence, there are cases where faulty brazing occurs and where the positioning pin is dropped or deformed by a load applied at the time of positioning the heat exchanger onto the vehicle body.
Further, in a construction such that the bracket supporting the positioning pin is fixed to the main body of a heat exchanger by brazing, in a brazing step is also presented a problem that the bracket is deformed with the deformation of the main body of the heat exchanger, causing the deformation of the positioning pin, that is, the slight inclination of the positioning pin.
The present invention is made in view of the foregoing matter, and it is an object of the present invention to provide a heat exchanger and a method of manufacturing the same, which has a structure capable of reducing the number of parts and the number of assembling steps, and properly fixing a positioning pin to a container.
According to an aspect, the heat exchanger has a core, a container, a pin, and a brazing material. The core has a plurality of tubes. The container has a tubular part and a cap part closing an end of the tubular part. The tubular part is located at an end of the core portion. The cap part is formed with a hole. The pin extends through the hole of the cap part along an axis of the container. The cap part and the pin are bonded to each other by the brazing material. Further, the heat exchanger has a preliminary fixing portion by which the pin is preliminarily fixed to the cap part before being bonded with the brazing material.
In the above construction, the pin is preliminarily fixed to the cap part before being bonded with the brazing material. As such, the number of parts and the number of assembling steps reduce, as compared with the conventional heat exchanger. Further, the pin can be properly fixed to the cap part without being dropped and deformed or displaced. Also, the quality of brazing between the pin and the cap part improves.
The method of manufacturing the heat exchanger includes arranging a container having a tubular part at an end of a core portion having tubes, inserting a pin into a hole of a cap part, preliminarily fixing the pin to the cap part and bonding the pin and the cap part by a brazing material at the same time as bonding the tubes and the tubular part.
In the above method, the pin is preliminarily fixed to the cap part before being bonded with the brazing material. As such, the pin is properly bonded to the cap part without increasing the number of parts and the number of assembling steps.
For example, the preliminary fixing is performed by deforming a portion of the pin such that the pin is supported by the cap part. As such, the method reduces costs and improves productivity. Alternatively, the preliminary fixing can be performed by deforming an end of the pin, the end projecting from the cap part into an inside of the container, such that a portion of the cap part is sandwiched between the deformed portion and another portion of the pin. As such, the pin is preliminarily fixed to the cap member by effectively using a projecting portion of the pin.
Further, the preliminary fixing can be performed by welding a portion between the cap member and the pin. Furthermore, the preliminary fixing can be performed by press-fitting the pin into the hole of the cap member. Accordingly, the pin is preliminary and properly fixed to the cap member with reduced costs and high productivity.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which like parts are designated by like reference numbers and in which:
Hereinafter, an embodiment of the heat exchanger of the present invention will be described with reference to FIGS. 1 to 10.
The heat exchanger is for example employed as a condenser as a radiator for an air conditioner, as shown in
As shown in
Also, the condenser has a first tank 2 and a second tank 3 as containers on ends of the condenser core part 1. Namely, the first tank 2 and the second tank 3 are arranged at the ends of the condenser tubes 1a and in communication with the condenser tubes 1a. The second tank 3 is provided with a separation wall such that its inner space is divided into a first space and a second space in an axial direction thereof, e.g., in an up and down direction in
Further, a modulator pipe 5 is provided outside of the second tank 3. The modulator pipe 5 allows communication between a cooling portion and a supercooling portion that are formed in the condenser core part 1.
The first and second tanks 2, 3 and the modulator pipe 5 communicate with the insides of all condenser tubes 1a. The first and second tanks 2, 3 and the modular pipe 5 extend in the direction of the width of the condenser core part 1, in other words, in a stacking direction of the condenser tubes 1a and the condenser fins. Here, the stacking direction corresponds to the up and down direction in
As shown in
The outer surfaces of the tubular parts 2a, 3a are coated with a brazing material. Likewise, the cap parts 6 are coated with a brazing material. Thus, the condenser tubes 1a and the cap parts 6 are brazed to the tubular parts 2a, 3a by the brazing material as being heated.
Here, the cross sectional shape of the condenser tube 1a is not limited to a special shape as long as the condenser tube 1a allows refrigerant to pass through. For example, the condenser tube 1a has a flat tubular shape including two generally flat walls, which are parallel to each other, and curved walls connecting the flat walls.
In the condenser, for example, the refrigerant discharged from a compressor (not shown) is introduced into the first space of the second tank 2. Then, the refrigerant is distributed into a first half section of the condenser core part 1. That is, the refrigerant is distributed into a half of the stacked condenser tubes 1a. The refrigerant is collected into the first space of the second tank 3 and then introduced into the modulator pipe 5. In the modulator pipe 5, the refrigerant is separated into a gas-phase refrigerant and a liquid-phase refrigerant.
The liquid-phase refrigerant is introduced into the second space of the second tank 3 and further distributed into the remaining half of the condenser tubes 1a. Further, the refrigerant is collected in the second space of the first tank 2 and then introduced to a decompression device (not shown).
The condenser core part 1 is provided with side plates as reinforcement members. The side plates are arranged at both sides (upper and lower ends in
The above condenser, as an example of the heat exchanger is constructed in such a way that the fixing parts provided on one side of the condenser can be freely fixed to and unfixed from a part of the vehicle by fastening or unfastening bolts and nuts. When the condenser is mounted to the part of the vehicle, the condenser needs to be positioned with respect to the part of the vehicle. Therefore, the condenser is provided with pins 4 for positioning to the part of the vehicle, as shown in
The pins 4 extend outside of the first tank 2 and the second tank 3 from the cap parts 6 in a direction parallel to the axis of the first tank 2 and the second tank 3. The extending portions of the pins 4 are received by the part of the vehicle, whereby the condenser is positioned. After the pins 4 are positioned, the fixing parts provided on the opposite sides of the pins 4 are fixed to the part of the vehicle by bolts and nuts. Accordingly, the condenser is mounted and fixed to the vehicle body. The above mounting and fixing structure is not limited to the condenser, but can be employed to other heat exchangers.
Next, the relationship between the pin 4 and the cap part 6 to which the pin 4 is fixed will be described with reference to
The cap part 6 is a part for closing one end of the first tank 2 and has a hole 7 formed substantially in the center. The pin 4 has a shaft portion 4b, a flange portion 9, an inserting portion 8a, and a projecting portion 8. The shaft portion 4b extends to outside of the first tank 2 in the axial direction of the first tank 2 for positioning when the pin 4 is coupled to the cap part 6. The flange portion 9 is positioned outside the cap part 6 when the pin 4 is coupled to the cap part 6. The flange portion 9 has a shape larger than the hole 7. The flange portion 9 has a first surface 9a that faces outside and a second surface 9b that faces an outer surface of the cap part 6.
The inserting portion 8a is a part located within the hole 7 when the pin 4 is coupled to the cap part 6. The projecting portion 8 is positioned closer to the tip end of the pin 4 than the inserting portion 8a. Namely, the projecting portion 8 is located on a side opposite to the flange portion 9 with respect to the inserting portion 8a. The projecting portion 8 projects into the first tank 2 from an inner surface of the cap part 6. The projecting portion 8 is positioned closer to the tip of the pin 4 than the flange portion 9 and is positioned on a side opposite to the shaft portion 4a, which projects outward from the cap part 6 for positioning.
The tubular part 2a of the first tank 2 and the cap part 6 are separate parts and are bonded to each other by the brazing material with which the cap part 6 is coated previously. The cap part 6 has an edge portion 6b bonded to the end surface of the tubular part 2a and a recessed portion 6a depressed inside the tubular part 2a in the axial direction of the tubular part 2a from the outer surface of the edge portion 6b.
In a state where the pin 4 is fixed to the cap part 6, the pin 4 and the cap part 6 are in a relationship such that the first surface 9a of the flange portion 9 is nearly flush with the outer surface of the edge portion 6b. Namely, the amount of depression of the recessed portion 6a, i.e., a distance between the outer surface of the recessed portion 6a and the outer surface of the edge portion 6b is substantially equal to a thickness of the flange portion 9.
Here, the condenser as an example of the heat exchanger has preliminary fixing means (preliminary fixing portion) for provisionally fixing the pin 4 to the cap part 6 before the pin 4 and the cap part 6 are finally bonded to each other by the brazing material. Namely, the pin 4 and the cap part 6 are preliminarily fixed to each other before bonded by the brazing material.
For example, the preliminary fixing means is means for provisionally fixing the pin 4 to the cap part 6 by deforming a portion of pin 4 to form a deformed portion such that the pin 4 is partly fixed to or partly engaged with the cap part 6. Also, the preliminary fixing means can be means for provisionally fixing the pin 4 to the cap part 6 by deforming the projecting portion 8 to form a deformed portion (clamp portion) for sandwiching or holding the cap part 6 between the deformed portion and the flange portion 9. Further, the preliminary fixing means can be means for provisionally fixing the pin 4 to the cap part 6 by forming a welding portion so as to partly bridge the cap part 6 and the pin 4. Moreover, the preliminary fixing means can be means for provisionally fixing the pin 4 to the cap part 6 by pressing (press-fitting) the pin 4 into the hole 7 to form a press-fitted portion.
Next, a process of manufacturing the condenser will be described with reference to FIGS. 4 to 10.
First, at a step S100, the condenser core part 1 is assembled by alternately arranging the condenser tubes 1a and the condenser fins. Also, the side plates are arranged on both sides of the condenser core part 1 for reinforcement, and the first tank 2 and the second tank 3 are arranged at both ends of the condenser core part 1. In this condition, the cap parts 6 to which the pins 4 are fixed are not arranged to the first tank 2 and the third tank 3 yet.
Next, in a step S200, the pins 4 are inserted into the holes 7 of the cap parts 6. At this time, the projecting portion 8 of the pin 4 is inserted into the hole 7 from the side on which the recessed portion 6a is formed. That is, the projecting portion 8 of the pin 4 is inserted along a direction denoted by an arrow A in
Here, the pin inserting step S200 and the container arranging step S100 may be reversed in the order because the respective steps handle separate parts. In other words, the pin inserting step S200 may be performed before the container arranging step S100 or both steps S100, S200 may be performed at the same time.
Then, in a step S300, the pin 4, which has been inserted to the cap part 6, is provisionally or preliminarily fixed to the cap part 6. Examples of this preliminary fixing step include a deforming step shown in
In a step S400, the cap parts 6 on which the pins 4 are provisionally fixed are arranged at the ends the first tank 2 and the second tank 3. Next, in a step S500, the condenser as assembled is put in a furnace. Thus, the brazing material previously applied to the respective parts is melted, thereby fusing the respective parts. Accordingly, the pins 4 are bonded to the cap parts 6 at the same time as bonding the condenser tubes 1a to the first tank 2 and the second tank 3 with the brazing material.
By the brazing step S500, the pins 4, which had been provisionally fixed to the cap parts 4, are securely bonded to the cap parts 6 without being tilted and the cap parts 6 are bonded so as to close the openings of the ends of the first tank 2 and the second tank 3. Accordingly, the pins 4 function as pins for positioning the condenser to the part of the vehicle.
In the above, the cap parts 6 and the tubular parts 2a, 3a are provided as separate parts and bonded to each other at the bonding step S500. However, in a case that each tank 2, 3 is constructed of a container integrally having the cap part 6 and the tubular part 2a, 3a, the cap arranging step S400 is not performed.
The above process shown in
Moreover, the process shown in
Next, examples of the preliminary fixing step S300 will be described with reference to
First, as shown in
Next, as shown in
Further, as shown in
In the step S150a, a pin 4A having a shaft portion 4a, a flange portion 9, a projecting portion 10 is made. As shown in
Further, the projecting portion 10 has a taper shape. Namely, a size (e.g., diameter) of the projecting portion 10 reduces toward a tip end of the projecting portion 10. Also, the size of the projecting portion 10 is set such that the projecting portion 10 can not fully pass through the hole 7 unless a load larger than a predetermined level is not applied to the pin 4. Namely, the load larger than the predetermined level is required to insert the projecting portion 10 into the hole 7 up to a position that the second side 9b of the flange 9 contacts the recessed portion 6a.
Namely, an end 10a of the projecting portion 10 has an outer size smaller than the bore size of the hole 7 and a base portion (inserting portion) 10b of the projecting portion 10, which connects to the flange portion 9, has an outer size slightly larger than the bore size of the hole 7.
Then, in the step 300c, the pin 4A is press-fitted to the cap part 6 while inserting into the hole 7. Specifically, the projecting portion 10 is inserted into the hole 7 and further press-fitted to the hole 7 of the cap part 6 up to a position that the second side 9b of the flange portion 9 is brought into contact with the outer surface of the recessed portion 6a of the cap part 6. When the second side 9b of the flange portion 9 is brought into contact with the outer surface of the recessed portion 6a, the perimeter of the hole 7 makes close contact with the base portion 10b of the projecting portion 10 and is further expanded outward in the radial direction further than the initial size.
As described above, the heat exchanger exemplary as the condenser is so constructed as to include: the core part 1 having the plurality of tubes 1a and the plurality of fins alternately stacked; the first tank 2 and the second tank 3 each of which has the tubular part 2a, 3a arranged on one end of the condenser core part 1 and has the cap part 6 for closing the end of the tubular part 2a, 3a; the pins 4, 4A inserted into the holes 7 of the cap parts 6 and extending in the axial direction of the first tank 2 and the second tank 3 from the cap parts 6; the brazing material for brazing the cap parts 6 to the pins 4, 4A; and the preliminary fixing means (preliminary fixing portion) for provisionally fixing the cap parts 6 to the pins 4, 4A before bonding them with the brazing material, or, in a state where the brazing material is not applied to them. According to this construction, members such as plates or brackets for holding the pins 4, 4A are not required and the positioning of the pins 4, 4A with respect to the cap parts 6 is stabilized. As such, the number of parts and the number of man-hours or assembling steps can be reduced. Further, the separation and deformation of the positioning pins 4, 4A can be reduced.
Moreover, the pins 4, 4A are positioned outside the cap parts 6 and have the flange portions 9 larger than the holes 7, the inserting portions 8a, 10a positioned within the holes 7, and the projecting portions 8, 10 projecting into the first tank 2 and the second tank 3 from the cap parts 6, respectively. When this construction is adopted, the shapes of the outer peripheral surfaces in the axial direction of the pins 4, 4A contribute to the stabilizing of the positions of the cap parts 6 and the pins 4, 4A at the time of preliminary fixing. Hence, this can enhance a provisional fixing work and a brazing quality.
Further, the cap parts 6 and the tubular parts 2a, 3a can be separate parts and are bonded to each other by the brazing material, respectively. Also, the cap parts 6 have edge portions 6b bonded to the end surfaces of the tubular parts 2a, 3a and the recessed portions 6a recessed inside from the end surfaces of the tubular parts 2a, 3a, respectively. The first surfaces 9a of the flange portions 9 are nearly flush with the outer surfaces 6b of the cap parts 6, respectively. In other words, the first surface 9a of the flange portions 9 coincides with the outer surfaces 6b of the cap parts 6 in the axial direction of the pins 4, 4A In this construction, the positions of the cap parts 6 and the pins 4, 4A at the time of preliminary fixing are stabilized. Hence, this can enhance a provisional fixing work and a brazing quality. Moreover, since the area of a rubber mounting base when the condenser is mounted in the vehicle can be secured, wear of rubber can be reduced. With this, resistance to vibration improves.
Also, the preliminary fixing portion is defined by the deformed portion formed by deforming a portion of the pin 4. Accordingly, the preliminary fixing portion can be provided at high productivity without increasing costs.
The pin 4 has the projecting portion 8 projecting through the hole 7 and the preliminary fixing portion is provided by the deformed portion formed by deforming the projecting portion 8. The pin 4 is preliminary fixed to the cap part 6 by holding the cap part 6 between the deformed portion and the flange portion 9. Accordingly, the preliminary fixing portion having a higher holding force can be provided by utilizing the projecting portion 8.
When the preliminary fixing portion is provided by the welding portion for bridging the cap part 6 and a portion of the pin 4, more reliable provisional fixing can be performed. Further, when the preliminary fixing means is provided by the press-fitted portion formed by press-fitting the pin 4A into the hole 7, provisionary fixing of low cost and high productivity and having an excellent holding force can be performed.
In the method of manufacturing a heat exchanger, the first tank 2 and the second tank 3 having the tubular parts 2a, 3a are arranged on the respective ends of the core part 1 having the plurality of tubes 1a. Also, the pins 4, 4A are preliminarily fixed to the cap parts 6 by inserting into the holes 7 formed in the cap parts 6. Further, the tubes 1a are bonded to the tubular parts 2a, 3a of the first tank 2 and the second tank 3 by the brazing material. At the same time, the pins 4, 4A are bonded to the cap parts 6 by the brazing material. By this method, the number of parts and the number of man-hours or assembling steps are reduced. Also, the separation or drop of the pins 4, 4A from the cap parts 6 and the deformation of the pins 4, 4A are reduced.
The method can further include the step of forming the pins 4, 4A to have the flange portions 9 larger than the holes 7, the inserting portions 8a, 10a to be inserted into the holes 7, and the projecting portions 8, 10 further extending from the inserting portions 8a, 10a. The pins 4, 4A are inserted to the holes 7 of the cap parts 6 such that the flange portions 9 are located outside the cap parts 6 and the inserting portions 8a, 10a are located within the holes 7, respectively. In this method, in the step of inserting the pins 4, 4A into the respective holes 7, the shapes of the outer peripheral surfaces in the axial direction of the pins 4, 4A enhance stability in the positional relationship between the cap parts 6 and the pins 4, 4A. Thus, preliminary fixing is performed with reliability. Hence, this method enhances a brazing quality.
Further, the method can further include the step of forming the first tank 2 and the third tank 3. Namely, the cap parts 6 and the tubular parts 2a, 3a are formed as separate parts. The cap parts 6 are brazed to the tubular parts 2a, 3a at the same time as bonding the tubes la to the tubular parts 2a, 3a and the pins 4, 4A to the cap parts 6 in the step of bonding by the brazing material. In this method, the cap parts 6 to which the pins 4, 4A are preliminarily fixed are arranged to and bonded to the tubular parts 2a, 3a. As such, the quality of preliminary fixing can be stabilized and productivity can be enhanced.
In the step of preliminary fixing, the portion of the pin 4 is deformed so as to be fixed to the cap part 6. Accordingly, the preliminary fixing can be performed at high productivity without increasing costs.
In inserting the pin 4 to the hole 7 of the cap part 6, the pin 4 is inserted in such a way that a portion of the pin 4 passes and projects through the hole 7 to provide the projecting portion 8. Then, in preliminary fixing, the projecting portion 8 is deformed so that the cap part 6 is held between the deformed portion of the projecting portion 8 and the flange portion 6. In this method, the preliminary fixing portion having a sufficient holding force can be formed by utilizing the projecting portion 8.
Alternatively, in the step of preliminary fixing, a portion between the cap part 6 and the pin 4 can be welded to each other so as to bridge between them. As such, the reliability of provisional fixing improves.
Also, in the step of the preliminary fixing, the pin 4A having the tapered projecting portion 10 can be press-fitted to the hole 7 of the cap part 6. In this case, the inserting step and the preliminary fixing step can be performed simultaneously. As such, the preliminary fixing having a sufficient holding force can be performed without increasing costs.
Here, the shapes of the pins 4, 4A are not limited to the illustrated examples of
Further, the above structures and methods can be also employed to heat exchangers other than the condenser for the vehicle air conditioner.
The example embodiments of the present invention are described above. However, the present invention is not limited to the above example embodiments, but may be implemented in other ways without departing from the spirit of the invention.
Number | Date | Country | Kind |
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2005-348488 | Dec 2005 | JP | national |