JP2019105403A - Heat exchanger - Google Patents

Abstract

To provide a heat exchanger which can obtain improvement of support rigidity of a connector 7 securely by a reinforcement stay 8 without being influenced by dispersion of positions of the connector 7 bent like a L-character.SOLUTION: In a connector 7 like a L-character, an end portion is stopped to a top portion plate 4 of an oil cooler by a caulked joint, and an intermediate lateral portion 7a is supported as making a reinforcement stay 8 intervene. The reinforcement stay 8 has a base portion 15, a standing portion 16, and a connector support portion 17 which concaves like a circular arc, and bending lines 19, 20 among these three pieces extend along a longitudinal direction of the connector 7. The connector support portion 17 which locates like a virtual line L deforms by being pushed when stopping the connector 7 by the caulked joint in a free condition before mounting, and always comes in contact with a peripheral face of the connector 7 tightly as keeping parallelism. Secure brazing is obtained as being brazed in a tight contact condition like this.SELECTED DRAWING: Figure 11

Description

  The present invention relates to a heat exchanger formed by laminating a plurality of relatively thin core plates made of aluminum alloy or the like, and more particularly to a heat exchanger having a connector comprising a circular pipe bent in a substantially L shape as a fluid inlet or outlet. .

  As a heat exchanger such as an oil cooler, one having a configuration in which a plurality of relatively thin core plates made of aluminum alloy or the like are laminated and two fluid passages are alternately formed between adjacent core plates is known. In this type of heat exchanger, as described in Patent Document 1, a top plate relatively thicker than the core plate is disposed on the core portion on which the core plates are stacked, and this top plate Also, a connector comprising a circular pipe that constitutes an inlet or an outlet of one fluid, for example, cooling water, is attached.

  The connector consists of a metal tube of the same kind as the core plate and top plate, for example aluminum alloy, and the end is pre-clamped to the top plate, and then the top plate is brazed when the entire oil cooler is brazed in the furnace It is brazed to. This connector often has an L-shaped bent shape as disclosed in Patent Document 1 in order to reduce the space taken up by the tubes connected thereto. In this case, a connector, previously configured in an L-shape, is attached to the top plate.

  In the configuration in which the L-shaped connector is attached to the top plate, the insertion force at the time of inserting the tube into the tip of the connector, the excitation force accompanying the vibration of the tube, etc. Since a load in the swinging direction acts on the mounting portion between them, damage or the like of the brazing portion in the mounting portion tends to be relatively problematic.

  Patent Document 2 discloses a configuration in which an auxiliary support member is interposed between the lateral portion of the connector extending along the upper surface of the top plate and the top plate in order to improve the support rigidity of the connector. . Patent Document 2 describes that this auxiliary support member can be attached by brazing. The auxiliary support member disclosed herein is a V-shaped metal plate folded in two, and the bent portion is directed to the base portion (attachment portion) of the connector and the lateral portion of the connector It is sandwiched between the top plate.

JP 2014-95492 A U.S. Patent Application Publication No. 2004/0177950

  In order to fix the auxiliary support member in Patent Document 2 by brazing, the connector and the auxiliary support member are temporarily assembled on the top plate, and then heated together in a furnace with a large number of core plates to braze the portions simultaneously. However, the dimensional accuracy of the distance or gap generated between the lateral part of the connector and the top plate is comparable due to the slight inclination at the attachment between the connector and the top plate and the dimensional dispersion of individual components. As low as possible. Therefore, it is difficult to reliably braze the auxiliary support member sandwiched between the both to the connector and the top plate, and product variations are likely to occur.

  In particular, since the auxiliary support member of Patent Document 2 is V-shaped in half along the longitudinal direction of the connector, when the distance between the lateral portion of the connector and the top plate changes, the outer peripheral surface of the connector The angle of the support piece which supports from below changes up and down, and the parallelism with the connector outer peripheral surface is lost. As a result, only one longitudinal end (one end on the connector base side or one end on the connector distal end) of the support piece is in point contact or line contact with the outer peripheral surface of the connector (arc line contact along the cross section of the connector) As a result, the brazing strength is insufficient.

  That is, in the configuration of Patent Document 2, the support rigidity of the L-shaped connector can not be sufficiently increased.

According to the present invention, there is provided a core portion formed by laminating a plurality of core plates constituting a fluid passage, a top plate laminated on the top of the core portion and relatively thicker than the core plate, a fluid inlet or And a connector comprising a substantially L-shaped curved circular pipe attached to the top plate as an outlet, wherein the heat exchanger is integrally brazed with each other,
The connector is crimped to the top plate by expanding and deforming the end of the top plate through the mounting hole,
A reinforcement stay is brazed between the top plate and a lateral portion of the connector extending parallel to the top plate;
The reinforcement stay is formed by bending a single metal plate, a base joined to the surface of the top plate, an upright portion rising from a side edge of the base in a direction orthogonal to the top plate, and A connector support which is folded back from the upper edge of the upstanding portion to the upper side of the base and is recessed in an arc shape in cross section along the outer peripheral surface of the lateral portion to receive the lateral portion; A first fold between the base and the upstanding portion and a second fold between the upstanding portion and the connector support extend along the axial direction of the lateral portion.
It is characterized by

  The above-described reinforcement stay is sandwiched between the connector and the top plate when the substantially L-shaped connector is crimped to the top plate, and finally, the two are brazed to each other.

  The reinforcement stay is formed by bending a single metal plate, and the base and the connector support are connected via an intermediate rising portion, so that the space between the lateral portion of the connector and the top plate is formed. The distance between the base and the connector support can be set slightly larger than the design reference value (median value) of the distance or distance in consideration of tolerances or variations of the distance or distance. Therefore, the base is in close contact with the surface of the top plate, and the connector support is brazed in close contact with the outer peripheral surface of the connector.

  In particular, since the second bending line between the rising portion and the connector support portion is configured to be along the axial direction of the lateral portion, the connector when the reinforcing stay is sandwiched between the connector and the top plate The deformation of the support occurs while keeping the connector support parallel to the connector outer peripheral surface. That is, the deformation for absorbing the variation of the distance between the lateral portion of the connector and the top plate does not reduce the parallelism between the connector support and the outer peripheral surface of the connector. Therefore, a band-like contact surface or brazed region along the axial direction of the connector can be reliably secured between the inner peripheral surface of the connector support and the outer peripheral surface of the connector which are recessed in an arc shape in cross section.

  In one preferable aspect of the present invention, the reinforcement stay includes a pair of projecting pieces projecting from the bottom surface of the base at both ends of the base, and a pair of the projecting pieces engaged with the top plate. Holes are provided for positioning the The reinforcement stay is positioned by the engagement between the projection piece and the hole.

  In one preferable aspect of the present invention, the connector support portion recessed in an arc shape in cross section has a dimension in the axial direction of the lateral portion in comparison with a dimension in the chord direction along the cross section of the lateral portion. Has a long, substantially rectangular shape.

  Further, in a preferable aspect of the present invention, the curvature radius of the arc of the connector support portion is set to be slightly larger than the curvature radius of the outer peripheral surface of the lateral direction portion. Therefore, slight tolerances and variations do not cause the connector to be brazed without being in intimate contact with the connector support.

  Further, in a preferred aspect of the present invention, the second bending line is constituted by a curved portion with a relatively small radius of curvature which is curved in a direction opposite to the arc of the connector support. When the connector is crimped to the top plate, the connector support portion is bent at the curved portion to be in close contact with the outer peripheral surface of the connector.

  According to this invention, since the reinforcement stay joins the substantially L-shaped connector and the top plate, the rigidity of the connector and the strength of the mounting portion are improved. In particular, even if there is variation in the distance between the lateral portion of the connector and the top plate, it is possible to obtain a state in which the connector support portion of the reinforcement stay is axially brazed to the outer peripheral surface of the connector. The support rigidity of the connector can be obtained high.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view of the oil cooler which becomes one Example of this invention. The top view of an oil cooler. The front view of an oil cooler. Rear view of the oil cooler. The side view of an oil cooler. The perspective view which looked at a reinforcement stay from two different directions, respectively. (A) Front view of reinforcement stay, (b) Top view, (c) Left side view, (d) Rear view, (e) Right side view. The perspective view which showed the assembly process of the connector in a top plate. Sectional drawing which showed each process along the AA of FIG. 2 in the same assembly process. Sectional drawing which showed each process along the BB line of FIG. 2 in the same assembly process. FIG. 11 is an enlarged cross sectional view showing a cross section in a third step of FIG. 10; The top view of the oil cooler which showed the brazing area | region.

  Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

  FIGS. 1 to 5 show an oil cooler that cools, for example, lubricating oil for an automobile internal combustion engine by heat exchange with cooling water, as an embodiment of a heat exchanger according to the present invention. In the following, the terms "upper" and "lower" will be used with reference to the postures of FIGS. 3 to 5 as necessary to facilitate understanding, but when using an actual oil cooler, the diagrams of FIGS. It is not limited to the mounting posture of 5.

  In the oil cooler, a core portion 1 formed by laminating a large number of thin plate-like core plates 5 with fin plates (not shown) is placed on a relatively thick plate-like bottom plate 2, and this core portion A top plate 4 thicker than the core plate 5 is stacked on top of the top plate 1. The top plate 4 is attached with two connectors 6 and 7 each consisting of a circular pipe serving as a cooling water inlet and a cooling water outlet. Here, while one connector 6 extends vertically along the stacking direction of the core plates 5, the other connector 7 has a substantially L direction so as to have a lateral portion 7 a extending parallel to the top plate 4. It is bent in the shape of a letter, and extends long so that the tip 7 b is located outside the outer shape of the core 1. A reinforcement stay 8 is disposed between the top plate 4 and the lateral portion 7a so as to support the connector 7 at an intermediate position. Note that which of the connectors 6 and 7 is used as the cooling water inlet is optional.

  The components of the oil cooler (i.e., the core plate 5, the bottom plate 2, the top plate 4, the reinforcement stay 8, the connectors 6, 7) are all made of an aluminum-based material, and are assembled after being assembled in a predetermined state. Each part is brazed integrally by heating in a furnace while holding the tool. As a brazing material supply method, the core plate 5 or the like is a so-called clad material provided with a layer of brazing material (for example, aluminum material having a melting point lower than that of the base material) on the surface of the base material made of aluminum material. It may be formed, or another brazing material in the form of a sheet or the like may be disposed on the joining surface. The reinforcing stay 8 is preferably a clad material provided with a brazing material layer on one side.

  The core portion 1 is formed by laminating a large number of shallow dish-shaped core plates 5 having the same rectangular shape in basic shape together with fin plates (not shown), so that an oil passage can be formed between two adjacent core plates 5. The cooling water passages are alternately configured, and the core plate 5 actually includes a plurality of types of core plates 5 with different details, and these are appropriately combined. The configuration of the core unit 1 is a known configuration as disclosed in Patent Document 1 and is not a main part of the present invention, and thus the detailed description thereof is omitted. The connectors 6 and 7 are connected to two diagonally opposite places of the rectangular core portion 1, and the cooling water flowing from one of them flows through the plurality of cooling water passages between the core plates 5, and from the other side leak. The oil inlet and the oil outlet of the oil to be subjected to heat exchange are provided on the bottom plate 2 corresponding to two places on the remaining diagonal of the core portion 1, and the oil flowing from the oil inlet is between the core plates 5. The oil flows out of the oil outlet after flowing through several oil passages. Thus, heat is exchanged between the oil and the cooling water.

  The core plate 5 of the illustrated example is configured to have side walls 5a that rise in a tapered shape at the periphery, and the side walls 5a of the core plates 5 stacked in the vertical direction are brazed to each other. The oil passage and the cooling water passage are sealed around. The side wall portions 5a respectively extend obliquely upward, and thus, the uppermost core plate 5 protrudes upward from the upper surface of the core plate 5 so as to surround four sides. The top plate 4 stacked on the top core plate 5 is located on the inner peripheral side of the side wall 5a of the four sides of the top core plate 5, and the thickness thereof is the upper side of the side wall 5a. Less than the amount of protrusion. Accordingly, the top plate 4 is dropped into the side wall 5 a, and the periphery thereof is surrounded by the side wall 5 a of the core plate 5. In the present invention, the core unit 1 is not necessarily limited to the configuration of the illustrated example.

  The connectors 6 and 7 are brazed with one end crimped to the top plate 4. At two corners of the top plate 4, cylindrical (more specifically, tapered cylindrical) connector mounting bosses 10 and 11 for mounting the connectors 6 and 7 are formed to project upward. Further, at one end of the connectors 6 and 7 whose tips are inserted into the connector mounting bosses 10 and 11, bulging parts 12 and 13 are formed in advance in an annular shape, and the connector mounting bosses 10 and 11 are formed. The connectors 6 and 7 are crimped to the top plate 4 by expanding and deforming the tips of the connectors 6 and 7 inserted therein from the lower surface side of the top plate 4. The caulking step will be further described later.

  The reinforcement stay 8 is sandwiched between the lateral portion 7a of the connector 7 and the top plate 4 when the L-shaped bent connector 7 is crimped to the top plate 4, and finally, they are It is attached.

  6 and 7 show the reinforcement stay 8 alone. The reinforcement stay 8 is formed, for example, by bending and forming a plate-like clad material made of an aluminum-based material provided with a brazing material layer on one side as described above. As shown, the reinforcement stay 8 has a rectangular flat plate-like base 15 joined to the surface of the top plate 4 and a top plate which is bent by 90 ° from one side edge along the longitudinal direction of the base 15 A standing portion 16 rising in a direction perpendicular to 4, a connector support portion 17 folded back so as to overlap from the upper edge of the standing portion 16 to the upper side of the base 15, and the same plane as the standing portion 16 at both front and rear ends of the base 15 And a pair of projecting pieces 18 projecting downward from the bottom surface of the base 15. The brazing material layer of the clad material is the bottom side of the base 15.

  The connector support portion 17 has a rectangular shape in plan view as shown in FIG. 7B, but as shown in FIG. 7A and FIG. In order to receive from the side, it has a curved shape which is recessed in an arc shape in cross section along the outer peripheral surface of the lateral portion 7a. Thus, the connector support portion 17 recessed in an arc shape in cross section has a substantially rectangular shape in which the dimension in the axial direction of the lateral portion 7a is longer than the dimension in the chord direction along the cross section of the lateral portion 7a. There is no.

  A first fold line 19 forming the boundary between the base portion 15 and the rising portion 16 extends along the axial direction of the lateral portion 7 a, and between the rising portion 16 and the connector support portion 17. The second folding line 20 bounding the two also extends along the axial direction of the lateral portion 7a. In other words, the first fold line 19 and the second fold line 20 extend parallel to the central axis of the connector support 17 having a shape approximate to a semi-cylinder. Also, the two fold lines 19 and 20 are parallel to each other. Here, the bend along the first bend 19 is clearly bent 90 ° so as not to be as rounded as possible. On the other hand, the second bending line 20 is constituted by a curved portion with a relatively small radius of curvature, which is curved in the direction opposite to the arc of the connector support 17. In other words, the bending portion along the second bending line 20 is not clearly bent, but is curved in a semicircular shape with a small radius of curvature. Therefore, the second fold line 20 also does not appear as a clear straight line. The base 15 is bent with respect to the rising portion 16 with a pair of protruding pieces 18 left on both sides, and the protruding pieces 18 separated from the base 15 extend along the same plane as the rising portion 16. There is.

  The radius of curvature of the upper surface (inner peripheral surface) of the connector support portion 17 recessed in an arc shape is set to be slightly larger than the radius of curvature of the outer peripheral surface of the corresponding lateral direction portion 7a. In one example, it has a large curvature radius of about 0.1 to 0.2 mm. Further, the distance between the base 15 and the connector support 17 in the component single state of the reinforcement stay 8, more specifically, the distance between the bottom of the base 15 and the upper surface (inner peripheral surface) of the connector support 17 is the top It is set slightly larger than the design reference value (median value) of the distance between the plate 4 and the lateral portion 7a of the connector 7. In one example, it is set large about 0.2 mm.

  Next, a process of caulking the connector 7 to the top plate 4 while sandwiching the reinforcement stay 8 will be described with reference to process explanatory views of FIGS. The attachment of the connector 7 shown in these figures to the top plate 4 takes place prior to brazing. FIG. 8 is a perspective view showing each of the four steps. FIG. 9 and FIG. 10 show each process as a cross section along line A-A and line B-B in FIG.

  The first process of these figures shows each part before assembly. The top plate 4 has a rectangular plate shape, and as described above, the cylindrical connector mounting boss 11 for mounting the connector 7 is formed to project upward. On the inner periphery of the connector mounting boss portion 11, a circular mounting hole 11a having a diameter corresponding to the outer diameter of the pipe of the connector 7 is opened. Further, in the central portion of the top plate 4, a pair of positioning holes 21 engaged with the pair of projecting pieces 18 of the reinforcement stay 8 are formed penetrating. As described above, the connector 7 is provided with an annular bulging portion 13 at the end portion, and the tip end cylindrical portion 24 linearly extending on the tip side of the bulging portion 13.

  The second process of FIGS. 8 to 10 shows the stage in which the reinforcement stay 8 is arranged on the top plate 4. The pair of projecting pieces 18 of the reinforcement stay 8 is engaged with the pair of holes 21 to position the reinforcement stay 8 with respect to the top plate 4.

  The third process of FIGS. 8 to 10 shows a state in which the connector 7 is temporarily assembled to the top plate 4. That is, the distal end cylindrical portion 24 of the connector 7 is inserted into the mounting hole 11 a of the top plate 4, and the bulging portion 13 is in contact with the distal end of the connector mounting boss portion 11. The reinforcement stay 8 is sandwiched between the top plate 4 and the lateral portion 7a of the connector 7, the base 15 of the reinforcement stay 8 abuts on the surface of the top plate 4, and the connector support 17 is in the lateral direction. Contact the outer peripheral surface of 7a. Then, in the state of temporary assembly, the connector 7 is pressed toward the top plate 4 through a jig (not shown). By this, the bulging part 13 will be in the state which contact | abutted reliably to the connector mounting boss part 11 front-end | tip.

  At this time, if the connector 7 is in the correct position and the distance between the lateral portion 7a of the connector 7 and the top plate 4 is as designed standard value, the connector 7 is pressed with the jig. The connector support portion 17 is pushed toward the top plate 4 by the lateral direction portion 7a, and the connector support portion 17 is displaced so as to have an interval along the design reference value. FIG. 11 is an enlarged view of the state of the third step of FIG. 10, and the phantom line L shows the initial state of the connector support 17. As shown in FIG. As shown in FIG. 11, the connector support portion 17 is bent and deformed mainly about the second bending line 20 and is in a state along the actual position of the connector 7. Note that part of this bending deformation is elastic deformation and part is plastic deformation. Further, since the arc-shaped cross-sectional shape of the connector support portion 17 has a diameter slightly larger than the diameter of the outer peripheral surface of the connector 7, the connector support portion 17 is cantilevered around the second bending curve 20. Even when the connector 7 is displaced, it is possible to obtain a state in which the outer peripheral surface of the connector 7 is always in contact with the central portion of the connector support 17 in a wide range.

  The fourth process of FIGS. 8 to 10 is a caulking process, and in a state where the connector 7 and the top plate 4 are firmly fixed by the jig in the third process, the connector 7 which protrudes through the mounting hole 11a. The distal end cylindrical portion 24 is expanded and deformed in a tapered manner by a caulking tool. As a result, as shown in the fourth step of FIG. 9, a tapered expanded caulking portion 24a is formed, and the caulking portion 24a and the bulging portion 13 clamp the connector mounting boss 11 from both sides. And the connector 7 is fixed to the top plate 4.

  This completes the attachment of the connector 7 to the top plate 4. The other linear connector 6 is likewise crimped and attached to the top plate 4.

  The top plate 4 to which the connectors 6 and 7 are attached as described above is temporarily assembled together with the core plate 5 and the bottom plate 2 constituting the core portion 1. And each part is brazed by heating in a furnace in the state which fixed and hold | maintained the whole with the jig | tool. By this brazing process, the caulking portions of the connectors 6 and 7 are further brazed to braze between the base 15 of the reinforcement stay 8 and the top plate 4 and between the connector support 17 and the connector 7 respectively. . Accordingly, the middle lateral portion 7a of the L-shaped connector 7 is supported by the top plate 4 through the reinforcement stay 8, and the rigidity of the connector 7 and the strength of the attachment portion crimped to the top plate 4 are increased. improves.

  Here, in the caulking of the connector 7 as described above, the lateral direction portion 7 a of the connector 7 and the top plate 4 may be caused by a slight inclination at the attachment portion between the connector 7 and the top plate 4 or dimensional dispersion of individual components. The dimensional accuracy of the distance or gap between them is relatively low. On the other hand, in the above embodiment, the distance between the base portion 15 of the reinforcement stay 8 and the connector support portion 17 is set in advance to be large and follow the actual dimensions when the connector 7 is crimped. Since the reinforcement stay 8 is deformed, no gap is generated in the brazing portion, and reliable brazing can be performed in close contact with each other.

  In particular, as can be understood from FIG. 11 and FIG. 6, the connector support portion 17 is centered on the connector 7 centering on the second bending curve 20 along the axial direction of the connector 7 (which forms a curved shape with a small radius of curvature). It is displaced like a cantilever while maintaining a parallel state with the axis. Therefore, even if the connector support 17 is displaced according to the actual distance between the lateral portion 7a of the connector 7 and the top plate 4, the parallelism between the outer peripheral surface of the connector 7 and the connector support 17 is reduced. There is no FIG. 12 schematically shows a brazing region BR obtained between the outer peripheral surface of the connector 7 and the connector support portion 17. As described above, between the outer peripheral surface of the connector 7 and the connector support portion 17 As a result of always being able to ensure parallelism, as shown in the drawing, it is possible to obtain a brazed region BR in the form of a long strip over the entire length of the connector support 17.

  Accordingly, the variation in quality of the brazed portion of the reinforcement stay 8 is reduced, and damage to the mounting portion of the connector 7 due to external force or vibration can be prevented in advance.

  In the above embodiment, although one of the two connectors 6 and 7 is L-shaped and the other is linear, the present invention is also applicable to a heat exchanger having a configuration in which both are bent in an L-shape. It is applicable.

  Also, the term "extending parallel to the top plate" in relation to the lateral part 7a of the connector 7 of the present invention does not necessarily have to be geometrically exactly "parallel", although it has a slight inclination. It also includes such an aspect that is seemingly parallel.

DESCRIPTION OF SYMBOLS 1 ... Core part 2 ... Bottom plate 4 ... Top plate 5 ... Core plate 7 ... Connector 7a ... Horizontal part 8 ... Reinforcement stay 11 ... Connector attachment boss part 15 ... Base 16 ... Upstand part 17 ... Connector support part 18 ... Protrusion piece 19: first folding line 20: second folding line

Claims (5)

A core portion formed by stacking a plurality of core plates constituting a fluid passage, a top plate stacked on the top of the core portion and relatively thicker than the core plate, and a top plate as a fluid inlet or outlet And a connector comprising a substantially L-shaped curved circular tube attached to the heat exchanger, wherein each component is integrally brazed,
The connector is crimped to the top plate by expanding and deforming the end of the top plate through the mounting hole,
A reinforcement stay is brazed between the top plate and a lateral portion of the connector extending parallel to the top plate;
The reinforcement stay is formed by bending a single metal plate, a base joined to the surface of the top plate, an upright portion rising from a side edge of the base in a direction orthogonal to the top plate, and A connector support which is folded back from the upper edge of the upstanding portion to the upper side of the base and is recessed in an arc shape in cross section along the outer peripheral surface of the lateral portion to receive the lateral portion; A first fold between the base and the upstanding portion and a second fold between the upstanding portion and the connector support extend along the axial direction of the lateral portion.
A heat exchanger characterized by   The reinforcement stay has a pair of projecting pieces projecting from the bottom surface of the base at both ends of the base, and the top plate is provided with a pair of positioning holes with which the pair of projecting pieces engage. The heat exchanger according to claim 1, characterized in that:   The connector support portion recessed in an arc shape in cross section has a substantially rectangular shape in which the dimension in the axial direction of the lateral portion is longer than the dimension in the chord direction along the cross section of the lateral portion. , The heat exchanger according to claim 1 or 2, characterized in that.   The heat exchanger according to any one of claims 1 to 3, wherein the radius of curvature of the arc of the connector support portion is set to be slightly larger than the radius of curvature of the outer peripheral surface of the lateral portion. .   The second bending line according to any one of claims 1 to 4, characterized in that it is constituted by a curved portion of a relatively small radius of curvature curved in a direction opposite to the arc of the connector support portion. Heat exchanger described.

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