Heat exchanger and power transmission device

Abstract

To improve heat exchange efficiency of a heat exchanger.SOLUTION: A heat exchanger 100 includes a pair of header tanks 20, and a plurality of heat exchange portions 30 stacked in a stacking direction, having a flow passage forming portion 32 forming a flow passage 33 in which cooling water flows in an inside thereof, and performing heat exchange with lubricating oil flowing outside. Each of the heat exchange portions 30 has a pair of plates 31 stacked in the stacking direction so that recessions 31a provided in an inner side of the flow passage forming portion 32 face with each other to form the flow passage 33, the flow passage 33 is arranged in an offset state so as not to overlap in the stacking direction with the flow passage 33 of another heat exchange portion 30 adjacent in the stacking direction, and the flow passage forming portion 32 has a flow passage enlargement portion 41 having a height H [mm] in the stacking direction larger than 1 / 2 of a pitch P [mm] of the heat exchange portions 30 adjacent in the stacking direction (P / 2 [mm]).SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a heat exchanger. [Background technology]

[0002] Patent Document 1 discloses a heat exchanger in which multiple embossments are formed in areas of a heat exchange member where no communicating flow paths are formed, so that the embossments abut the communicating flow paths of an adjacent heat exchange member, thereby maintaining the distance between adjacent heat exchange members. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-151392 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the heat exchanger described in Patent Document 1, there are many portions of the heat exchange member where no communicating flow passages are formed, and therefore there is a risk of the heat exchange performance being reduced.

[0005] The present invention has been made in consideration of the above problems, and has an object to improve the heat exchange performance of a heat exchanger. [Means for solving the problem]

[0006] According to one embodiment of the present invention, a heat exchanger includes a pair of header tanks and a plurality of heat exchange sections stacked in a stacking direction, each of which has a flow path forming section forming a flow path section inside through which a first fluid flows, and which exchanges heat with a second fluid flowing outside, and each of the heat exchange sections has a pair of plates stacked in the stacking direction so that recesses provided on the inside of the flow path forming section face each other to form the flow path section, and the flow path section is offset in the stacking direction so as not to overlap with the flow path section of another heat exchange section adjacent to the stacking direction, and the flow path forming section has a flow path expansion section whose height in the stacking direction is greater than 1 / 2 the pitch of the heat exchange sections adjacent to each other in the stacking direction. Effect of the Invention

[0007] In the above embodiment, the flow passage portion through which the first fluid flows in the heat exchanger is offset so as not to overlap with the flow passage portion of another heat exchanger adjacent in the stacking direction, and the flow passage forming portion has an expanded flow passage portion whose height in the stacking direction is greater than 1 / 2 the pitch of the heat exchanger adjacent in the stacking direction. Therefore, in the portion where the expanded flow passage portion is provided, the heat exchange area is increased by the size of the expanded flow passage portion, and the flow passage of the second fluid is narrowed, thereby increasing the flow rate of the second fluid. Therefore, it is possible to increase the amount of heat exchange between the first fluid flowing through the flow passage portion inside the expanded flow passage portion and the second fluid flowing outside. Therefore, it is possible to improve the heat exchange performance of the heat exchanger. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is an external perspective view of a heat exchanger according to an embodiment of the present invention, as viewed obliquely from above. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1, illustrating the first bypass prevention member on the bottom surface of the heat exchanger. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1, illustrating the second bypass prevention member on the side surface of the heat exchanger. [Figure 4]FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 1, and is a perspective view showing one of the plates. [Diagram 5] FIG. 5 is a diagram showing a cross section of the heat exchanger taken along line VV in FIG. [Figure 6] FIG. 6 is a diagram showing a cross section of the heat exchange portion taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a configuration diagram for explaining a modified example of the state in which the heat exchanger is attached to the vehicle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a heat exchanger 100 according to an embodiment of the present invention will be described with reference to the drawings.

[0010] First, the overall configuration of a heat exchanger 100 will be described with reference to FIGS.

[0011] Fig. 1 is an external perspective view of the heat exchanger 100 as viewed obliquely from above. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1, illustrating a first bypass prevention member 13 on the bottom surface of the heat exchanger 100. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 1, illustrating a second bypass prevention member 14 on the side surface of the heat exchanger 100.

[0012] 1, the heat exchanger 100 is mounted on a vehicle 1. Specifically, the heat exchanger 100 cools lubricating oil for lubricating and cooling a power transmission device 2 mounted on the vehicle 1 by heat exchange with cooling water circulating outside. The heat exchanger 100 is a so-called microtube heat exchanger with a flow path height of 1.0 mm or less, which will be described later.

[0013] The power transmission device 2 is, for example, a transmission that changes the speed of power from a drive source and transmits it, or an electric drive device having an electric motor and a reduction gear, etc. Here, the cooling water corresponds to the first fluid, and the lubricating oil corresponds to the second fluid.

[0014] The power transmission device 2 is provided with an attachment portion 3 formed in a concave shape. A heat exchanger 100 is inserted into the attachment portion 3. The attachment portion 3 has a side portion 3a and a bottom portion 3b (see FIGS. 2 and 3). The side portion 3a has an inlet 3c through which the lubricating oil flows in, and an outlet (not shown) through which the lubricating oil flows out after passing through the heat exchanger 100. The lubricating oil flows in the attachment portion 3 so as to pass linearly through the heat exchanger 100 attached to the attachment portion 3.

[0015] The heat exchanger 100 comprises a core 10, a cover member 11 as a first end member, a bottom plate 12 as a second end member (see Figures 2 and 3), a first bypass prevention member 13 (see Figure 2), and a second bypass prevention member 14 (see Figure 3).

[0016] The core section 10 has a pair of header tanks 20 and a plurality of heat exchange sections 30. The core section 10 exchanges heat between the lubricating oil and the cooling water flowing in a direction intersecting (here, substantially perpendicular to) the lubricating oil. A first bypass prevention member 13 is provided on the bottom surface of the core section 10. A second bypass prevention member 14 is provided on the side surface of the core section 10.

[0017] The core section 10 is disposed such that the heat exchange section 30 is provided on the flow path between the inlet 3c and the outlet through which the lubricating oil flows, and the header tank 20 is provided at a position deviated from the flow path between the inlet 3c and the outlet. This makes it possible to increase the flow rate of the lubricating oil flowing through the heat exchange section 30, thereby improving the heat exchange performance of the heat exchanger 100.

[0018] In the following, the direction in which the plates 31 (see Figure 2) constituting the multiple heat exchange sections 30 are stacked is referred to as the "stacking direction", the direction in which the cooling water flows within the heat exchange section 30 is referred to as the "cooling water flow direction", and the direction in which the lubricating oil flows between adjacent heat exchange sections 30, which is a direction that intersects with the flow direction (here, approximately perpendicular), is referred to as the "lubricating oil flow direction" or "offset direction".

[0019] The header tanks 20 are provided upstream and downstream in the cooling water flow direction of the core section 10. One header tank 20 provided upstream of the core section 10 is connected to a cooling water inlet 11a. The other header tank 20 provided downstream of the core section 10 is connected to a cooling water outlet 11b.

[0020] As shown in Fig. 2, a plurality of heat exchange units 30 are provided by stacking them at equal intervals (equal pitch) in the stacking direction. Each heat exchange unit 30 has a pair of plates 31 stacked in the stacking direction. The heat exchange unit 30 has a flow path forming portion 32 (see Fig. 4) that forms a flow path portion 33 therein through which cooling water flows. The heat exchange unit 30 exchanges heat with the lubricating oil flowing outside. The specific configuration of the heat exchange unit 30 will be described in detail later with reference to Figs. 4 to 6.

[0021] The lid member 11 is attached to one end of the core portion 10 in the stacking direction. The lid member 11 fixes the core portion 10 from one end. The lid member 11 is attached to the power transmission device 2 so as to sandwich a seal member (not shown). The lid member 11 closes the space between the mounting portion 3 of the power transmission device 2 and the outside. A cooling water inlet 11a that allows cooling water to flow into the core portion 10, and a cooling water outlet 11b that allows cooling water to flow out from inside the core portion 10 are connected to the lid member 11.

[0022] 1, the cooling water inlet 11a is a pipe for introducing cooling water into the core section 10. The cooling water inlet 11a is connected to the cover member 11, and allows the cooling water flowing from the outside to flow into the core section 10. The cooling water that flows into the core section 10 from the cooling water inlet 11a flows through the header tank 20 so as to spread throughout a flow path section 33 (described later) in the core section 10.

[0023] The cooling water outlet 11b is a pipe for discharging the cooling water from the core portion 10. The cooling water outlet 11b is connected to the cover member 11, and causes the cooling water that has flowed through each flow path portion 33 to flow out to the outside via the header tank 20.

[0024] As shown in Fig. 2, the bottom plate 12 is attached to the other end of the core portion 10 in the stacking direction. The bottom plate 12 fixes the core portion 10 from the other end. The bottom plate 12 separates the lubricating oil flowing in the power transmission device 2 from the cooling water flowing in the core portion 10 so that they do not mix. The bottom plate 12 is provided with a first bypass prevention member 13.

[0025] The first bypass prevention member 13 is a sealing plate disposed at an angle to the lubricating oil flow direction. The first bypass prevention member 13 is a flat plate made of metal such as an aluminum alloy. Specifically, the first bypass prevention member 13 is disposed so as to be spaced farther from the bottom plate 12 in the stacking direction toward the upstream side in the lubricating oil flow direction. The upstream end of the first bypass prevention member 13 is fixed to the bottom plate 12 by brazing or the like.

[0026] When the first bypass prevention member 13 is attached to the mounting portion 3, its end portion on the upstream side in the lubricating oil flow direction abuts against the bottom surface portion 3b and deforms so as to reduce the inclination angle with respect to the bottom plate 12. As a result, the first bypass prevention member 13 is fixed in a state where it is pressed against the bottom surface portion 3b.

[0027] The first bypass prevention member 13 blocks the flow of lubricating oil to prevent a bypass flow from occurring in which the lubricating oil flows from upstream in the lubricating oil flow direction through between the core portion 10 and the bottom portion 3b to downstream without passing through the core portion 10. When the lubricating oil flows through the first bypass prevention member 13, the lubricating oil hits the inclined surface and is further pressed against the bottom portion 3b. Thus, the first bypass prevention member 13 can improve the sealing performance by utilizing the flow of the lubricating oil.

[0028] 3, the second bypass prevention member 14 is a comb-shaped member attached to the side surface of the core portion 10. The second bypass prevention member 14 is a flat plate made of metal such as an aluminum alloy. The second bypass prevention member 14 is integrally formed by brazing or the like while attached to the core portion 10.

[0029] The second bypass prevention member 14 has a seal portion 14a and multiple insertion portions 14b. The seal portion 14a is inserted between the side end face of the core portion 10 and the side surface portion 3a of the attachment portion 3 to fill the gap. The insertion portions 14b are inserted between adjacent heat exchange portions 30 in the stacking direction to fill the gap. The insertion portions 14b are also inserted between the heat exchange portion 30 provided at one end in the stacking direction and the cover member 11, and between the heat exchange portion 30 provided at the other end in the stacking direction and the bottom plate 12 to fill the gap.

[0030] The second bypass prevention member 14 blocks the flow of lubricating oil so as to prevent a bypass flow from occurring in which the lubricating oil flows from upstream in the lubricating oil flow direction through between the core portion 10 and the side portion 3a to downstream without passing through the core portion 10. The second bypass prevention member 14 is provided at each of both ends of the first bypass prevention member 13 in the cooling water flow direction. In this way, the first bypass prevention member 13 and the second bypass prevention member 14 can prevent the occurrence of a bypass flow of the lubricating oil.

[0031] Next, a specific configuration of the heat exchange section 30 will be described with reference to Figs.

[0032] Fig. 4 is a view corresponding to a cross section taken along line IV-IV in Fig. 1, and is a perspective view showing one of the multiple plates 31. Fig. 5 is a view showing a cross section of the heat exchange section 30 taken along line VV in Fig. 4. Fig. 6 is a view showing a cross section of the heat exchange section 30 taken along line VI-VI in Fig. 4. Note that Fig. 4 shows only the vicinity of one header tank 20 on the upstream side in the cooling water flow direction, but the vicinity of the other header tank 20 on the downstream side in the cooling water flow direction is configured in the same manner.

[0033] As shown in Fig. 4, the heat exchange section 30 has a flow path forming section 32. As shown in Fig. 5 and Fig. 6, the heat exchange section 30 has a pair of plates 31 stacked in the stacking direction.

[0034] The plates 31 are stacked in the stacking direction to integrally form the header tank 20 and the heat exchange section 30. This allows the header tank 20 and the heat exchange section 30 to be integrally formed simply by stacking and brazing the plates 31, thereby reducing the manufacturing cost of the heat exchanger 100.

[0035] The plates 31 constituting the same heat exchange section 30 are stacked in the stacking direction in opposite directions. The pair of plates 31 are formed in shapes that are plane symmetrical with respect to their mating surfaces. In this case, the pair of plates 31 may be formed in the same shape. In this case, the manufacturing cost of the heat exchanger 100 can be reduced. The pair of plates 31 may have only the flow path forming portion 32 of the same shape, and the position of the header tank 20 may be different. In other words, it is sufficient that the plates 31 constituting the same heat exchange section 30 have at least the flow path forming portion 32 of the same shape.

[0036] The flow passage forming section 32 forms a flow passage section 33 inside which the cooling water flows. The flow passage forming section 32 has a plurality of straight flow passage sections 40 and a plurality of communication flow passages 50.

[0037] The flow path section 33 has a height (flow path height) of 1.0 mm or less in the stacking direction. Specifically, the flow path height He (see FIG. 6) of the flow path expansion section 41, which has the greatest flow path height in the flow path section 33, is 1.0 mm or less. That is, the heat exchanger 100 is a so-called microtube heat exchanger.

[0038] 6, the flow path portion 33 is offset from the flow path portion 33 of another heat exchanger 30 adjacent thereto in the stacking direction so as not to overlap with the flow path portion 33 of another heat exchanger 30 adjacent thereto in the stacking direction. Specifically, the flow path portion 33 is offset from the flow path portion 33 of another heat exchanger 30 adjacent thereto in the stacking direction in the lubricating oil flow direction.

[0039] 4, the straight flow passage section 40 is a flow passage through which the cooling water flows linearly. The flow passage height at the position where the straight flow passage section 40 intersects with a communicating flow passage 50 (described later) is the same as the flow passage height in other parts of the communicating flow passage 50. The straight flow passage section 40 has a flow passage enlargement section 41, a transition section 42, and a narrowing section 43.

[0040] 6, the height H [mm] of the expanded flow passage portion 41 in the stacking direction is larger than 1 / 2 [mm] of the pitch P of the heat exchange portions 30 adjacent in the stacking direction. This increases the flow passage height of the flow passage portion 33 in the expanded flow passage portion 41. Therefore, even when the heat exchanger 100 is a microtube heat exchanger, it is possible to prevent the coolant flow passage portion 33 from being blocked during brazing.

[0041] Generally, microtube heat exchangers are manufactured by arranging thin tubes with a diameter of 1.0 mm or less at intervals. In contrast, in heat exchanger 100, the lubricant flow path is only partially narrowed at the position where flow path enlargement section 41 is provided, so that it is possible to manufacture the heat exchanger 100 in the same manner as a normal heat exchanger other than a microtube heat exchanger by simply controlling the dimensions of this position.

[0042] The lubricating oil flows between the multiple heat exchange sections 30 so as to cross the outside of the multiple flow path expansion sections 41. The flow path cross-sectional area of ​​the lubricating oil is minimum at the position where the flow path expansion section 41 is provided. In the portion where the flow path expansion section 41 is provided, the heat exchange area is increased by the size of the flow path expansion section 41, and the flow rate of the lubricating oil increases as the flow path cross-sectional area of ​​the lubricating oil decreases.

[0043] In this way, the flow passage section 33 through which the cooling water flows in the heat exchange section 30 is offset so as not to overlap with the flow passage section 33 of another heat exchange section 30 adjacent in the stacking direction, and the expanded flow passage section 41 has a height H [mm] in the stacking direction that is greater than 1 / 2 [mm] of the pitch P of the heat exchange sections 30 adjacent in the stacking direction (H>P / 2). That is, the inclined surfaces of the convex parts 31b described later of the expanded flow passage sections 41 provided in the adjacent heat exchange sections 30 overlap in the lubricating oil flow direction.

[0044] Therefore, in the portion where the enlarged flow path section 41 is provided, the heat exchange area is increased by the size of the enlarged flow path section 41, and the flow rate of the lubricating oil increases as the flow path of the lubricating oil becomes narrower. This increases the amount of heat exchanged between the cooling water flowing through the flow path section 33 inside the enlarged flow path section 41 and the lubricating oil flowing outside. This improves the heat exchange performance of the heat exchanger 100.

[0045] The transition section 42 gradually changes the height of the flow passage section 33 to the height at the flow passage expansion section 41. Specifically, the transition section 42 is formed obliquely in the cooling water flow direction, and gradually changes the flow passage cross-sectional area in the straight flow passage section 40. The transition section 42 is inclined so as to change linearly from the height H [mm] of the flow passage expansion section 41 to the height P / 2 [mm] of the communicating flow passage 50 on the downstream side of the flow passage expansion section 41. On the other hand, the transition section 42 is inclined so as to change linearly from the height P / 2 [mm] of the communicating flow passage 50 to the height H [mm] of the flow passage expansion section 41 on the upstream side of the flow passage expansion section 41.

[0046] By providing the transition sections 42 on both the upstream side and downstream side of the enlarged flow path section 41, the change in the flow path cross-sectional area in the flow path section 33 can be made gentler, and abrupt changes in the flow path cross-sectional area can be prevented.

[0047] The throttle section 43 is provided at the connection portion with the header tank 20. The throttle section 43 has a smaller flow passage cross-sectional area than other portions of the flow passage section 33. Specifically, the throttle section 43 is formed obliquely in the cooling water flow direction, and gradually changes the flow passage cross-sectional area in the straight flow passage section 40. The throttle section 43 is inclined so as to change linearly from the height P / 2 [mm] of the communicating flow passage 50 to the height H [mm] of the flow passage expansion section 41 on the downstream side of the header tank 20. On the other hand, the transition section 42 is inclined so as to change linearly from the height H [mm] of the flow passage expansion section 41 to the height P / 2 [mm] of the communicating flow passage 50 on the downstream side of the flow passage expansion section 41.

[0048] By providing the throttle portion 43, it is possible to make the change in the flow path cross-sectional area in the flow path portion 33 gentle and prevent the flow path cross-sectional area from changing suddenly. In addition, since the flow rate of the cooling water changes when the cooling water passes through the throttle portion 43, it is possible to obtain the effect of disturbing the flow of the cooling water.

[0049] The communicating flow passages 50 communicate with each other so that cooling water can flow between the adjacent straight flow passage sections 40. The flow passage height in the communicating flow passages 50 is P / 2 [mm]. That is, the communicating flow passages 50 are formed to have the same flow passage height as a whole, including the positions where they intersect with the straight flow passage sections 40.

[0050] By providing the communication flow passage 50, the flow rate of the cooling water can be made uniform in the multiple straight flow passage sections 40, where the cooling water is guided from the straight flow passage section 40 where the cooling water pressure is high to the straight flow passage section 40 where the cooling water pressure is low. This makes it possible to prevent the heat exchange performance in some of the straight flow passage sections 40 from decreasing, and improves the heat exchange performance of the entire heat exchanger 100.

[0051] In addition, the protrusions 50a of the communication passages 50 of the plates 31 adjacent in the stacking direction are in contact with each other in the stacked state and are joined by brazing (not shown). This makes it possible to properly secure the gap dimension in the stacking direction between the plates 31 that form the passages for the lubricating oil.

[0052] A pair of plates 31 constituting the heat exchange unit 30 have recesses 31a provided on the inner side of a flow path forming portion 32 facing each other to form a flow path portion 33. The plate 31 has a recess 31a, a protrusion 31b, and a joint portion 31c.

[0053] The recess 31a is formed in a concave shape on one of the flat surfaces by pressing the plate 31.

[0054] The protruding portion 31b is formed in a protruding shape on the other flat surface by pressing the plate 31. A recessed portion 31a is formed on the rear surface of the protruding portion 31b.

[0055] The joint portion 31c is formed continuously from the flow path expansion portion 41 formed by the recessed portion 31a and the protruding portion 31b. The joint portion 31c is a flat portion for joining a pair of plates 31 constituting the same heat exchange portion 30. The joint portions 31c of the pair of plates 31 constituting the heat exchange portion 30 are joined to each other by brazing.

[0056] In the offset direction (lubricant flow direction) in which the flow passage portions 33 are offset, the length L2 [mm] of the joint portion 31c where the pair of plates 31 are joined to each other is smaller than the length L1 [mm] of the protrusion 31b on the surface opposite to the recess 31a that forms the flow passage expansion portion 41 (L1>L2). That is, the inclined surfaces of the protrusions 31b of the flow passage expansion portions 41 provided in the adjacent heat exchange portions 30 overlap in the stacking direction.

[0057] This makes it possible to improve the heat exchange performance of the entire heat exchanger 100 by increasing the length L1 of the convex portion 31b that constitutes the flow path expansion section 41, which contributes to improving the heat exchange performance, and by decreasing the length L2 of the joint portion 31c, which contributes little to improving the heat exchange performance.

[0058] The angle α [deg] of the plate 31 inclined from the joint 31c toward the flow path expansion section 41 is an acute angle.

[0059] By setting the inclination angle α of the plate 31 to an acute angle, the change in the flow passage cross-sectional area in the flow passage portion 33 can be made gentler, and abrupt change in the flow passage cross-sectional area can be prevented. This makes it possible to suppress the generation of turbulence in the cooling water.

[0060] Next, a modified example of the state in which the heat exchanger 100 is attached to the vehicle 1 will be described with reference to FIG.

[0061] FIG. 7 is a configuration diagram for explaining a modified example of the state in which the heat exchanger 100 is attached to the vehicle 1. In FIG.

[0062] As shown in FIG. 7, the mounting portion 3 provided on the power transmission device 2 is provided at an angle to the flow of the lubricating oil.

[0063] The core section 10 is disposed such that the heat exchange section 30 is provided on the flow path between the inlet 3c and the outlet 3d through which the lubricating oil flows, and the header tank 20 is provided at a position deviated from the flow path between the inlet 3c and the outlet 3d. This makes it possible to increase the flow rate of the lubricating oil flowing through the heat exchange section 30, thereby improving the heat exchange performance of the heat exchanger 100.

[0064] The mounting portion 3 has a plurality of folded portions 5 at positions deviated from the flow path between the inlet 3c and the outlet 3d. This makes it possible to prevent the occurrence of a bypass flow in which the lubricating oil flows from upstream to downstream without passing through the core portion 10 of the heat exchanger 100.

[0065] According to the above embodiment, the following effects are achieved.

[0066] The heat exchanger 100 comprises a pair of header tanks 20, and a plurality of heat exchange sections 30 stacked in the stacking direction, each having a flow path forming section 32 forming a flow path section 33 therein through which cooling water flows, and performing heat exchange with lubricating oil flowing outside. Each heat exchange section 30 has a pair of plates 31 stacked in the stacking direction so that recesses 31a provided on the inside of the flow path forming section 32 face each other to form a flow path section 33, and the flow path section 33 is offset in the stacking direction so as not to overlap with the flow path section 33 of another heat exchange section 30 adjacent in the stacking direction. The flow path forming section 32 has a flow path expansion section 41 whose height H [mm] in the stacking direction is greater than 1 / 2 (P / 2 [mm]) of the pitch P [mm] of adjacent heat exchange sections 30 in the stacking direction.

[0067] According to this configuration, the flow passage portion 33 through which the cooling water flows in the heat exchanger 30 is offset so as not to overlap with the flow passage portion 33 of another heat exchanger 30 adjacent in the stacking direction, and the flow passage expansion portion 41 has a height H [mm] in the stacking direction that is greater than 1 / 2 the pitch P [mm] of the heat exchanger 30 adjacent in the stacking direction (H>P / 2). Therefore, in the portion where the flow passage expansion portion 41 is provided, the heat exchange area is increased by the size of the flow passage expansion portion 41, and the flow passage of the lubricating oil becomes narrower, thereby increasing the flow rate of the lubricating oil. Therefore, the amount of heat exchange between the cooling water flowing through the flow passage portion 33 inside the flow passage expansion portion 41 and the lubricating oil flowing outside can be increased. Therefore, the heat exchange performance of the heat exchanger 100 can be improved.

[0068] Moreover, the flow path forming portion 32 further includes a transition portion 42 that gradually changes the height of the flow path portion 33 to the height of the flow path enlarged portion 41 .

[0069] According to this configuration, the provision of the transition section 42 makes it possible to make the change in the flow path cross-sectional area in the flow path section 33 gentle, thereby preventing the flow path cross-sectional area from changing suddenly.

[0070] In addition, the flow passage forming section 32 has a throttle section 43 at the connection portion with the header tank 20, the throttle section 43 having a flow passage cross-sectional area smaller than that of the other portion of the flow passage section 33.

[0071] According to this configuration, the flow rate of the cooling water changes when the cooling water passes through the throttle portion 43, which has the effect of disturbing the flow of the cooling water.

[0072] In addition, in the offset direction (lubricant flow direction) in which the flow path portion 33 is offset, the length L2 [mm] of the joint portion 31c where the pair of plates 31 are joined to each other is smaller than the length L1 [mm] of the convex portion 31b on the opposite surface of the concave portion 31a that forms the flow path portion 33 (L1>L2).

[0073] According to this configuration, the heat exchange performance of the entire heat exchanger 100 can be improved by increasing the length L1 of the convex portion 31b that constitutes the flow path expansion section 41, which contributes to improving the heat exchange performance, and by decreasing the length L2 of the joint portion 31c, which does not contribute to improving the heat exchange performance.

[0074] Furthermore, at the position where the enlarged flow passage portion 41 is provided, the cross-sectional area of ​​the flow passage for the lubricating oil is the smallest.

[0075] According to this configuration, in the portion where the enlarged flow path section 41 is provided, the heat exchange area is increased by the size of the enlarged flow path section 41, and the flow rate of the lubricating oil is increased by reducing the cross-sectional area of ​​the flow path of the lubricating oil.

[0076] Moreover, the angle α [deg] of the plate 31 inclined from the joint 31c toward the flow path expansion section 41 is an acute angle.

[0077] According to this configuration, by making the angle α at which the plate 31 is inclined an acute angle, the change in the flow passage cross-sectional area in the flow passage portion 33 is made gentler, and a sudden change in the flow passage cross-sectional area can be prevented. This makes it possible to suppress the generation of turbulence in the cooling water.

[0078] In addition, the flow path forming section 32 has a plurality of straight flow path sections 40 having a flow path expansion section 41 through which the cooling water flows linearly, and a communicating flow path 50 that connects adjacent straight flow path sections 40 to allow the cooling water to flow, and the flow path height (P / 2) at the position where the straight flow path section 40 intersects with the communicating flow path 50 is the same as the flow path height (P / 2) in other parts of the communicating flow path 50.

[0079] According to this configuration, by providing the communicating flow passages 50, the cooling water is guided from the straight flow passage sections 40 with high cooling water pressure to the straight flow passage sections 40 with low cooling water pressure, and the flow rate of the cooling water can be made uniform in the multiple straight flow passage sections 40. This makes it possible to prevent the heat exchange performance in some of the straight flow passage sections 40 from decreasing, and improves the heat exchange performance of the entire heat exchanger 100.

[0080] Furthermore, the lubricating oil flows between the plurality of heat exchange sections 30 so as to cross the outside of the plurality of enlarged flow path sections 41 .

[0081] According to this configuration, when the lubricating oil flows between the heat exchange sections 30, it crosses the outside of the multiple enlarged flow passage sections 41, so that the heat exchange area is increased by the size of the enlarged flow passage sections 41, and the flow rate of the lubricating oil increases by narrowing the flow passage of the lubricating oil. Therefore, the heat exchange performance of the heat exchanger 100 can be improved.

[0082] Moreover, the plates 31 are stacked in the stacking direction to integrally form the header tank 20 and the heat exchange section 30 .

[0083] According to this configuration, the header tank 20 and the heat exchange section 30 can be integrally formed simply by stacking and brazing the plates 31, so that the manufacturing cost of the heat exchanger 100 can be reduced.

[0084] Furthermore, the protruding portions 50a of the communication channels 50 in the plates 31 adjacent to each other in the stacking direction are joined to each other.

[0085] According to this configuration, it is possible to ensure an appropriate gap dimension in the stacking direction between the plates 31 that form the flow paths of the lubricating oil.

[0086] In addition, the first fluid is cooling water and the second fluid is lubricating oil.

[0087] According to this configuration, when the lubricating oil for lubricating and cooling the power transmission device 2 of the vehicle 1 is cooled by the cooling water, it is possible to improve the heat exchange performance.

[0088] The height of the flow path portion 33 in the stacking direction is 1.0 mm or less.

[0089] According to this configuration, when the heat exchanger 100 is a so-called microtube heat exchanger, the heat exchange performance can be improved.

[0090] Although the embodiments of the present invention have been described above, the above-mentioned embodiments merely illustrate some of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above-mentioned embodiments. [Explanation of symbols]

[0091] 100 heat exchanger 1 vehicle 2. Power transmission device 20 Header Tank 30 Heat exchange section 31 Plate 31a Recess 31b Convex part 31c joint 32 Flow path forming section 33 Flow path 40 Straight flow passage section 41 Enlarged flow passage 42 Transition part 43 Squeezing section 50 Connecting flow path

Claims

1. 1. A heat exchanger comprising: A pair of header tanks; a plurality of heat exchange units stacked in a stacking direction, each having a flow path forming portion forming a flow path through which a first fluid flows inside, and exchanging heat with a second fluid flowing outside; Equipped with Each of the heat exchange units has a pair of plates that are stacked in the stacking direction so that recesses provided on the inner sides of the flow path forming units face each other to form the flow path units, The flow path portion is offset from the flow path portion of another heat exchanger adjacent to the heat exchanger in the stacking direction so as not to overlap with the flow path portion of the other heat exchanger in the stacking direction, the flow path forming portion has a flow path expansion portion whose height in the stacking direction is greater than half the pitch of the heat exchange portions adjacent to each other in the stacking direction, The flow path forming portion is a plurality of straight flow passage portions having the enlarged flow passage portions and through which the first fluid flows linearly; a communication flow path that communicates adjacent straight flow path portions so that a first fluid can flow therethrough; having a flow path height at a position where the straight flow path portion intersects with the communication flow path is the same as a flow path height in other parts of the communication flow path; heat exchanger.

2. 2. The heat exchanger of claim 1, In an offset direction in which the flow path portion is offset, a length of a joint portion where the pair of plates are joined to each other is shorter than a length of a convex portion on a surface opposite to the concave portion that forms the flow path portion. heat exchanger.

3. 3. The heat exchanger according to claim 1 or 2, The protruding portions of the communication flow paths of the plates adjacent to each other in the stacking direction are joined to each other. heat exchanger.

4. A power transmission device in which a heat exchanger is inserted into a mounting portion formed in a concave shape, The heat exchanger includes: A pair of header tanks; a plurality of heat exchange units stacked in a stacking direction, each having a flow path forming portion forming a flow path through which a first fluid flows inside, and exchanging heat with a second fluid flowing outside; Equipped with Each of the heat exchange units has a pair of plates that are stacked in the stacking direction so that recesses provided on the inner sides of the flow path forming units face each other to form the flow path units, The flow path portion is offset from the flow path portion of another heat exchanger adjacent to the heat exchanger in the stacking direction so as not to overlap with the flow path portion of the other heat exchanger in the stacking direction, the flow path forming portion has a flow path expansion portion whose height in the stacking direction is greater than half the pitch of the heat exchange portions adjacent to each other in the stacking direction, The flow path forming portion is a plurality of straight flow passage portions having the enlarged flow passage portions and through which the first fluid flows linearly; a communication flow path that communicates adjacent straight flow path portions so that a first fluid can flow therethrough; having a flow path height at a position where the straight flow path portion intersects with the communication flow path is equal to a flow path height in another portion of the communication flow path, The mounting portion has a side surface and a bottom surface, The side surface portion is an inlet through which a second fluid flows; an outlet through which the second fluid that has passed through the heat exchanger flows out; having Power transmission device.

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