JP4760693B2 - Heat exchanger - Google Patents

Description

  The present invention relates to a heat exchanger that performs heat exchange between fluids.

A heater core used as a heat exchanger of a vehicle air conditioner has a core part and a pair of tank parts connected to both ends of the core part (see, for example, Patent Document 1). Each tank portion has a cylindrical body in which a capsule and a sheet metal are combined, and a joint pipe that covers one end of the cylindrical body and can connect a pipe (long pipe) on the vehicle side. A hemispherical concave portion is formed on the joint surface of the cylindrical body in the joint portion between the cylindrical body and the joint pipe, and a protrusion corresponding to the concave portion is formed on the joint surface of the joint pipe. By fitting the projecting portion of the joint pipe into the concave portion of the cylindrical body, the cylindrical body and the joint pipe can be temporarily fixed at the time of assembly.
Japanese Patent Laid-Open No. 2001-215095

  However, in conventional heat exchangers, if the accuracy of the dimensions of the recesses and the protrusions is low, for example, the recesses are formed larger than necessary with respect to the protrusions, and at the stage of temporary fixing, between the cylindrical body and the joint pipe Shaking may occur. When heating for brazing is performed in this state, the brazing material layer formed on the contact surfaces of both the cylindrical body and the joint pipe is melted, so that the rattling is further increased. Therefore, there arises a problem that the joint pipe is brazed and fixed in a state of being displaced relative to the cylindrical body. For example, when the joint pipe is displaced and fixed in a direction in which the axial directions of the pipes are inclined with respect to the cylindrical body, when the long pipe having a relatively long length is connected to the joint pipe, the end of the long pipe Since the relative position with respect to the cylindrical body deviates from the specified position, it becomes a defective product.

  On the other hand, if the joint area between the joint pipe and the cylindrical body is increased over the entire circumference, it is possible to suppress misalignment in which the axial directions are inclined, but heat exchange is caused by the length of the tank portion becoming longer. The equipment becomes larger, which may be disadvantageous for mounting on a vehicle.

  The objective of this invention is providing the heat exchanger which can prevent the position shift of a joint pipe and can be reduced in size.

  In order to achieve the above object, the present invention employs the following technical means.

The invention described in claim 1 includes a tube (22) in which a plurality of layers are stacked and a fluid is circulated therein, a side plate (23) disposed outside in the stacking direction of the tubes (22), and a tube (22 ) And a joint pipe (40) which has a joint part (41) which is put on and joined to the opening end of the cylindrical body (33) and can be connected to other pipes. ) Are provided with engaging portions (42, 43) that engage with the side plate (23), and the engaging portions (42, 43) are provided on the side plate (23). ) Are engaged with both end faces (26, 27) in the width direction and have a triangular cross-sectional shape, and both end faces (26, 27) in the width direction of the side plate (23) It is characterized by roundness in the thickness direction .

According to the present invention, when the heat exchanger is assembled, the joint pipe (40) can be temporarily fixed to the side plate (23) by the engaging portions (42, 43). Can be prevented. Further, since the joint pipe (40) can be temporarily fixed to the side plate (23) by the engaging portions (42, 43), the joint area at the joint surface on the side plate (23) side with the cylindrical body (33) is reduced. it can. Therefore, the heat exchanger can be reduced in size.

The engaging portion (42, 43) engages the both widthwise end faces of the side plates (23) (26, 27), by having a triangular cross section, the engaging section (42 , 43) becomes narrower and easier to deform as it approaches the tip, so it is easy to engage the engaging portions (42, 43) with both end surfaces (26, 27) in the width direction of the side plate (23). become.

Further, both end surfaces (26, 27) in the width direction are rounded in the thickness direction of the side plate (23), so that the engaging portions (42, 43) are formed on both end surfaces (26, 27) in the width direction. When engaging, both end surfaces (26, 27) in the width direction can gradually deform the tip of the engaging portion (42, 43), so that the engaging portion (42, 43) can be prevented from being damaged. .

The invention according to claim 2 is characterized in that the engaging portions (42, 43) are integrally formed with the joint portion (41).

  This facilitates the formation of the engaging portions (42, 43) and improves the attachment strength of the engaging portions (42, 43) to the joint pipe (40) body.

  Here, the reference numerals in parentheses of the above means indicate the correspondence with specific means described in the embodiments described later.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 6. FIG. 1 is an external perspective view showing a configuration of a heater core 1 used in a vehicle air conditioner as a heat exchanger in the present embodiment. FIG. 2 is an exploded perspective view showing a main configuration of the heater core 1. As shown in FIG.1 and FIG.2, the heater core 1 has the core part 20 which performs heat exchange between engine cooling water and the air for air conditioning. The core portion 20 has a structure in which flat tubes 22 for circulating engine cooling water therein and wavy fins 21 thermally connected to the flat tubes 22 are alternately stacked in the vertical direction in FIG. ing.

  A pair of side plates 23 and 24 arranged in parallel with the flat tube 22 are disposed outside the core portion 20 in the stacking direction in order to mechanically reinforce the core portion 20. The side plate 23 disposed at the upper end in FIG. 1 of the core portion 20 includes a flat plate portion 23a and flange portions 23b bent toward the opposite side of the core portion 20 at both end portions of the flat plate portion 23a. And has a U-shaped cross-sectional shape as a whole. In the vicinity of both end portions of the side plate 23, fitting portions 25 extending from the flat plate portion 23a are formed. Engagement surfaces (both end surfaces in the width direction) 26 and 27 are formed at both end portions in the width direction of the fitting portion 25, respectively. The engaged surfaces 26 and 27 are, for example, rounded in the thickness direction of the side plate 23 (see FIGS. 3 and 4). In other words, the flat corners of the fitting portion 25 are rounded. The side plate 24 disposed at the lower end in FIG. 1 of the core portion 20 has the same shape as the side plate 23.

  A pair of tank portions 30 are connected to both ends of each flat tube 22 in the extending direction. The tank portion 30 has a substantially rectangular tubular body 33 formed by combining a sheet metal 31 having a U-shaped cross section and a capsule 32. A fitting hole 34 into which the fitting portion 25 of the side plate 23 is fitted is opened on the surface 33 a on the side plate 23 side of the sheet metal 31. The sheet metal 31 has a plurality of fitting holes 35 in which the distal end portions of the respective flat tubes 22 are respectively fitted in parallel with the fitting holes 34. Each flat tube 22 communicates with the cylindrical body 33 by being fitted into the fitting hole 35.

  A joint pipe 40 is connected to the opening end of one of the cylindrical bodies 33 (upper side in FIG. 1). The joint pipe 40 is connectable to other pipes such as a cap part 45 joined to the opening end of the cylindrical body 33 and a pipe on the vehicle side (for example, a long pipe), and a pipe part 44 having a relatively short length. And have. The cap portion 45 has a joint portion 41 that covers an opening end portion of the tubular body 33 and has an inner wall surface that is joined to the outer wall surface of the tubular body 33. A notch 41e surrounding the three sides of the side plate 23 is formed on the surface 41d of the joint 41 on the side plate 23 side. The notch 41e is opposed to the end surface 41a joined to the upper surface of the side plate 23, the engaged surface 26, the end surface 41b substantially perpendicular to the end surface 41a, the opposed surface 27, and the end surface 41b. And a substantially parallel end face 41c. The height H1 of the joint 41 at the surface 41d where the notch 41e is formed is lower than the height H2 of the joint 41 at a surface other than the surface 41d. The height H2 is set so that the bonding area between the bonding portion 41 and the cylindrical body 33 on the surface other than the surface 41d can be sufficiently secured.

  Further, the joint portion 41 is provided with a pair of claw-like engaging portions 42 and 43 that engage with the engaged surfaces 26 and 27 of the side plate 23, respectively. The engaging portion 42 protrudes from the end surface 41b toward the end surface 41c, and the engaging portion 43 protrudes from the end surface 41c toward the end surface 41b. The engaging portions 42 and 43 have the same thickness as the thickness of the joint portion 41 and are integrally formed with the joint portion 41 by pressing, cutting, or the like.

  A side cap 35 is connected to the opening end of the other side (lower side in FIG. 1) of the cylindrical body 33.

  FIG. 3 is a schematic diagram showing an engaged state between the joint pipe 40 and the side plate 23. 3, the structure which looked at the tank part 30 and the side plate 23 from the longitudinal direction of the side plate 23 is shown, and illustration of the core part 20 is abbreviate | omitted. FIG. 4 is an enlarged view showing a portion A of FIG. In FIG. 4, the shape of the engaging portion 42 before engaging the engaged surfaces 26 and 27 of the side plate 23 (before assembly) is indicated by a broken line.

  As shown in FIGS. 3 and 4, each of the engaging portions 42 and 43 has a right-angled isosceles triangular cross-sectional shape. The engaging portion 42 has an upper surface 42a that is substantially parallel to the end surface 41a of the joint portion 41 and substantially perpendicular to the end surfaces 41b and 41c, and an inclined side surface 42b that is formed obliquely with respect to the upper surface 42a. The oblique side surface 42b functions as a guide surface that guides the joint pipe 40 in a direction in which the notch 41e and the side plate 23 face each other. An angle θ1 formed by the upper surface 42a and the oblique side surface 42b is, for example, 45 °. The height H3 from the end surface 41b of the engaging part 42 before engaging the engaging parts 42 and 43 with the side plate 23 is, for example, 0.7 mm. The engaging portion 43 has a symmetrical shape with respect to the engaging portion 42.

  The thickness T1 of the side plate 23 is 1.3 mm, for example. Further, the side plate 23 has a maximum width in the central portion in the thickness direction (indicated by a broken line in FIG. 4). The gap G1 between the upper surface 42a of the engaging portion 42 and the end surface 41a of the joining portion 41 is such that the engaging portion 42 is engaged below the maximum width portion of the side plate 23 in the engaged surface 26. For example, 1.05 mm. A gap G2 between the distal end portion 42d of the engaging portion 42 and the distal end portion (not shown in FIG. 4) of the engaging portion 43 before engaging the engaging portions 42 and 43 with the side plate 23 is set on one side. The press-fitting width (press-fitting allowance) is narrower than the maximum width of the side plate 23 by 2 times (2W1) of W1 (for example, 0.1 to 0.2 mm), for example, 26.6 mm.

  In the assembling process for producing the assembly of the heater core 1, the joint pipe 40 is attached to the cylindrical body 33 after the fitting portion 25 of the side plate 23 is fitted into the fitting hole 34 of the cylindrical body 33. At this time, the joint pipe 40 is put on the cylindrical body 33 and the joint pipe 40 is press-fitted into the side plate 23, whereby the engaging portions 42 and 43 of the joint pipe 40 are engaged with the side plate 23. The

  When the joint pipe 40 is press-fitted into the side plate 23, the oblique side surface 42 b of the engaging portion 42 contacts the engaged surface 26 of the side plate 23, and then the notch portion 41 e is aligned with the side plate 23. The joint pipe 40 is guided in the opposite direction. The distal end portion 42d of the engaging portion 42 is gradually deformed by the engaged surface 26, and is bent toward the counter-pressing direction of the joint pipe 40 like the distal end portion 42c.

  Similarly, the oblique side surface (not shown in FIG. 4) of the engaging portion 43 abuts the engaged surface 27 of the side plate 23, and then the joint pipe in a direction in which the notch portion 41 e faces the side plate 23. Guide 40. The distal end portion of the engaging portion 43 is gradually deformed by the engaged surface 27 and bent toward the counter-pressing direction of the joint pipe 40.

  As a result, the end surface 41 a of the joint portion 41 abuts on the upper surface of the side plate 23, and the engaging portions 42 and 43 are engaged below the maximum width portion of the side plate 23 in the engaged surface 26. Therefore, the joint pipe 40 is temporarily fixed to the side plate 23 without rattling. Then, the heater core 1 is produced by assembling other parts to produce an assembly and brazing the components by heating.

  FIG. 5 is a cross-sectional view showing the configuration of the heater core 1 of the present embodiment taken along the line VV in FIG. FIG. 6 is a cross-sectional view showing a configuration of a conventional heater core 2 as a comparative example to the present embodiment, and corresponds to FIG. 5 and 6, the central axis of the pipe portion 44 of the joint pipe 40 is indicated by a one-dot chain line. Here, the heater core 2 has substantially the same configuration as the heater core 1 except that the engaging cores 42 and 43 are not provided. As shown in FIG. 5, in the heater core 1 of the present embodiment, the joint pipe 40 and the side plate 23 are assembled without rattling, so that the displacement of the joint pipe 40 with respect to the cylindrical body 33 hardly occurs during brazing. . Therefore, even if a long pipe is connected to the pipe portion 44, the tip position of the long pipe becomes a specified position.

  On the other hand, in the conventional heater core 2, as shown in FIG. 6, misalignment in which the surface 41 d of the joint pipe 40 having a small joint area with the cylindrical body 33 floats away from the side plate 23 is likely to occur. In this misalignment, a gap 46 is formed between the end face 41a and the side plate 23. Due to this misalignment, the central axis of the pipe portion 44 of the joint pipe 40 is inclined with respect to the central axis (indicated by a broken line in FIG. 6) of the pipe portion 44 when no misalignment occurs. Therefore, when a long pipe is connected to the pipe portion 44, the tip position of the long pipe is displaced from the specified position.

  Here, twelve heater cores 1 of the present embodiment and conventional heater cores 2 were produced, and the displacement of the joint pipe 40 for each of the two tank portions 30 was evaluated. First, a virtual plane that is perpendicular to the central axis of the pipe portion 44 when no displacement occurs and includes the point B on the side of the capsule 32 in the tip portion of the pipe portion 44 is defined as a reference plane D. 5 and 6 are positive (+) with respect to the reference plane D, and the distance between the reference plane D and the point C on the sheet metal 31 side of the tip end portion of the pipe portion 44 is a positional deviation value. As measured. That is, if the displacement value is positive, the central axis of the pipe portion 44 is inclined toward the sheet metal 31 (inside the heater cores 1 and 2). If the displacement value is negative, the pipe portion 44 is inclined. Is inclined toward the capsule 32 side (outside of the heater cores 1 and 2). For example, the displacement value of the heater core 1 shown in FIG. 5 is 0, and the displacement value of the heater core 2 shown in FIG. 6 is a negative value.

  The average value of the displacement values in one tank portion 30 (the signal hole side where the signal hole for product identification is formed) of the 12 heater cores 2 is −0.08 mm, the maximum value is +0.03 mm, and the minimum value is −0.26 mm, standard deviation σ was 0.05, process capability index Cp was 3.33, and process capability index Cpk was 2.83. In addition, the average value of the positional deviation values in the other tank part 30 (the non-signal hole side where no signal hole is formed) is -0.07 mm, the maximum value is +0.04 mm, the minimum value is -0.21 mm, and the standard deviation The σ was 0.07, the process capability index Cp was 2.43, and the process capability index Cpk was 2.10. Although fluid was circulated in each heater core 2, no fluid leakage occurred at the joint portion between the joint pipe 40 and the cylindrical body 33 in all the heater cores 2.

  On the other hand, the average value of the positional deviation values in one tank portion 30 (signal hole side) of the 12 heater cores 1 is +0.01 mm, the maximum value is +0.09 mm, the minimum value is −0.07 mm, and the standard deviation σ. Was 0.04, the process capability index Cp was 4.18, and the process capability index Cpk was 4.06. In addition, the average value of the displacement values in the other tank part 30 (counter signal hole side) is +0.02 mm, the maximum value is +0.08 mm, the minimum value is −0.11 mm, the standard deviation σ is 0.05, and the process capability The index Cp was 3.06 and the process capability index Cpk was 2.96. Although fluid was circulated in each heater core 1, fluid leakage at the joint portion between the joint pipe 40 and the cylindrical body 33 did not occur in all the heater cores 1.

  From these results, it can be seen that in the conventional heater core 2, the average value of the position shift values is negative, and therefore the position shift in which the central axis of the pipe portion 44 is inclined toward the capsule 32 is likely to occur. On the other hand, in the heater core 1 of the present embodiment, since the average value of the positional deviation values is close to 0 and the standard deviation σ is small compared to the heater core 2, there is a positional deviation in which the central axis of the pipe portion 44 is inclined toward the capsule 32 side. It turns out that it is hard to occur. In addition, since the heater core 1 has higher process capability indexes Cp and Cpk than the heater core 2, it can be seen that the quality achievement capability in the manufacturing process is improved.

  In the conventional heater core 2, the above-mentioned positional deviation can be suppressed by increasing the joining area between the surface 41 d of the joint pipe 40 on the side plate 23 side and the surface 33 a of the cylindrical body 33. It is necessary to increase both the height H1 of 41d and the height of the surface 33a. When the height of the surface 41d and the surface 33a is increased, the height of the entire heater core 2 is also increased, so that the heater core 2 is increased in size.

  In the present embodiment, the joint pipe 40 can be temporarily fixed to the side plate 23 by the engaging portions 42 and 43 provided on the surface 41 d of the joint pipe 40. For this reason, the above-described positional deviation of the joint pipe 40 can be suppressed. Further, since the joint pipe 40 can be temporarily fixed to the side plate 23 by the engaging portions 42 and 43, the joint area between the surface 41d of the joint pipe 40 and the surface 33a of the cylindrical body 33 can be reduced. Therefore, the heater core 1 can be reduced in size.

  In the present embodiment, since the engaging portions 42 and 43 have a triangular cross-sectional shape that becomes narrower toward the tip, the engaging portions 42 and 43 are engaged with the side plate 23. It becomes easy. Further, since the engaging portions 42 and 43 are provided with engaged surfaces 26 and 27 for guiding the joint pipe 40 in a direction in which the notch portion 41e and the side plate 23 face each other, the joint pipe 40 is attached to the side plate 23. It becomes easy to engage.

  Furthermore, in the present embodiment, the engaged surfaces 26 and 27 are rounded, so that the distal ends of the engaging portions 42 and 43 can be gradually deformed when the joint pipe 40 is press-fitted. Therefore, breakage of the engaging portions 42 and 43 can be prevented. The side plate 23 has a maximum width at the center in the thickness direction, and the engaging portion 42 is engaged below the maximum width portion of the side plate 23 in the engaged surface 26. . Therefore, the joint pipe 40 temporarily fixed by the engagement is difficult to be detached from the side plate 23.

  Further, in the present embodiment, since the engaging portions 42 and 43 are integrally formed with the joint portion 41 by press working and cutting processing, the engaging portions 42 and 43 can be easily formed, and the engaging portions 42 and 43 The attachment strength to the joint pipe 40 main body 43 is improved.

(Other embodiments)
In the first embodiment, the engaging portions 42 and 43 are integrally formed with the joint portion 41. However, the engaging portions 42 and 43 are formed of a different material from the joint portion 41 and are engaged before the assembly process. The portions 42 and 43 may be fixed to the end surfaces 41b and 41c of the joint portion 41, respectively.

It is an external appearance perspective view which shows the structure of the heat exchanger in 1st Embodiment of this invention. It is a disassembled perspective view which shows the principal part structure of the heat exchanger in 1st Embodiment of this invention. It is a schematic diagram which shows the engagement state between a joint pipe and a side plate. It is a schematic diagram which expands and shows the A section of FIG. It is sectional drawing which shows the structure of the heat exchanger cut | disconnected by the VV line | wire of FIG. It is sectional drawing which shows the structure of the conventional heat exchanger as a comparative example of 1st Embodiment of this invention.

Explanation of symbols

1 Heater core (heat exchanger)
20 Core part 21 Fin 22 Flat tube 23 Side plate 26, 27 Engagement surface (width direction both end surfaces)
30 Tank part 33 Tubular body 40 Joint pipe 41 Joint part 42, 43 Engagement part 44 Pipe part

Claims (2)

A plurality of stacked tubes (22) through which fluid flows; and
A side plate (23) disposed outside the tube (22) in the stacking direction;
A cylindrical body (33) communicated with the tube (22);
In the heat exchanger comprising a joint pipe (40) having a joint part (41) to be put on and joined to the open end of the cylindrical body (33), and a joint pipe (40) connectable to other pipes,
The joint portion (41) is provided with engagement portions (42, 43) that engage with the side plate (23) ,
The engaging portions (42, 43) engage with both end surfaces (26, 27) in the width direction of the side plate (23), and have a triangular cross-sectional shape,
The heat exchanger according to claim 1, wherein both end faces (26, 27) in the width direction of the side plate (23) are rounded in the thickness direction of the side plate (23) . The heat exchanger according to claim 1, wherein the engaging portions (42, 43) are integrally formed with the joint portion (41).

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