Power converter and inverter module

Abstract

To provide a power conversion device, etc., that enables miniaturization of the case housing the multilayer cooler. [Solution] The power conversion device 100 comprises a stacked cooler 30, a case 80, a plurality of heating elements 20, and a leaf spring 50. The stacked cooler 30 includes a plurality of cooling plates 31 stacked in the stacking direction SH, and partitions a plurality of housing spaces 40 between the refrigerant flow paths 33 formed by each cooling plate 31. The case 80 houses the stacked cooler 30. The heating elements 20 form at least a part of the power conversion circuit 10 and generate heat in conjunction with the operation of the power conversion circuit 10. The heating elements 20 are housed in the housing spaces 40. The leaf spring 50 is housed in a spring housing space 43, which is at least one of the housing spaces 40. The leaf spring 50 applies a restoring force along the stacking direction SH to the cooling plates 31 that partition the spring housing space 43.

Description

Technical Field

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[0001] The disclosure according to this specification relates to a power conversion device and an inverter module.

Background Art

[0002] Patent Document 1 discloses a power conversion device including a stacked cooler configured as a stacked structure. This stacked cooler is formed by stacking a plurality of cooling pipes and a plurality of semiconductor modules, and is pressurized in the stacking direction by a pressurizing member. The pressurizing member is supported by a supporting portion provided in a case via a supporting pin, and is disposed in a compressed state between the cooler and the supporting portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the power conversion device of Patent Document 1, a pressurizing member disposed outside the stacked cooler applies a force in the stacking direction to the cooling pipes. In such a structure, a supporting pin or the like for supporting the pressurizing member is required. In a configuration that requires a supporting pin or the like, it is difficult to miniaturize the case body that houses the stacked cooler.

[0005] An object of the present disclosure is to provide a power conversion device and an inverter module capable of miniaturizing a case body that houses a stacked cooler.

Means for Solving the Problems

[0006] To achieve the above objective, one disclosed embodiment is a power conversion device comprising: a stacked cooler (30) including a plurality of fluid coolers (31) stacked in the stacking direction (SH), with a plurality of housing spaces (40) between fluid flow paths (33) formed in each fluid cooler; a case body (80, 480) housing the stacked cooler; a plurality of heat-generating elements (20) that form at least a part of a power conversion circuit (10), generate heat in conjunction with the operation of the power conversion circuit, and are housed in the housing spaces; and a pressing member (50, 250) housed in at least one of the housing spaces, which is a pressing space (43), and applies a restoring force along the stacking direction to the fluid coolers that partition the pressing space.

[0007] Another disclosed embodiment is an inverter module housed in a case body (80, 480), comprising: a stacked cooler (30) including a plurality of fluid coolers (31) stacked in the stacking direction (SH), and dividing a plurality of housing spaces (40) between fluid flow paths (33) formed in each fluid cooler; a plurality of heat-generating elements (20) that form at least a part of an inverter circuit (10i), generate heat in conjunction with the operation of the inverter circuit, and are housed in the housing spaces; and a pressing member (50, 250) housed in at least one of the housing spaces, which is a pressing space (43), and applies a restoring force along the stacking direction to the fluid coolers that divide the pressing space.

[0008] In these embodiments, a pressing member housed in a pressing space partitioned within the multilayer cooler applies a force in the stacking direction to the fluid cooler. Thus, in a structure where the pressing member is located inside the multilayer cooler, a supporting member for the pressing member is unnecessary compared to a structure where the pressing member is located outside the multilayer cooler. As a result, the size of the case housing the multilayer cooler can be reduced.

[0009] Furthermore, the reference numbers in parentheses above and in the claims are merely examples of correspondences with specific configurations in the embodiments described later, and do not in any way limit the technical scope. In addition, combinations of claims not explicitly stated in the claims are also possible, provided that they do not cause any particular problems with the combination. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows the configuration of a power conversion device according to the first embodiment of the present disclosure. [Figure 2] This is a diagram illustrating the configuration for assembling an inverter module. [Figure 3] This is a perspective view showing the configuration of the grid spring used in the second embodiment. [Figure 4] This diagram shows the configuration of the power conversion device according to the third embodiment. [Figure 5] This diagram shows the configuration of a power conversion device according to the fourth embodiment. [Modes for carrying out the invention]

[0011] Several embodiments will be described below with reference to the drawings. In each embodiment, the same reference numerals are used for corresponding components, and redundant explanations may be omitted. If only a part of the configuration is described in each embodiment, the configuration of other embodiments described earlier can be applied to the other parts of that configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations from multiple embodiments can be partially combined even if not explicitly stated, as long as there are no particular problems with the combination.

[0012] (First Embodiment) The power converter 100 according to the first embodiment of the present disclosure, shown in Figure 1, is a vehicle control device used in an electric vehicle. The power converter 100 is mounted on the electric vehicle and connected to the traction battery and the motor generator. The power converter 100 performs power conversion between the traction battery and the motor generator. The power converter 100 is composed of a case 80 and an inverter module 110, etc.

[0013] The case 80 is made of a lightweight metal material with high heat dissipation properties, such as an aluminum alloy. The case 80 has side walls 81-84 and a bottom wall 85, and as a whole it has a box shape. An opening 86 is formed in one of the side walls 81. The internal space 80a of the case is partitioned by the side walls 81-84 and the bottom wall 85. The inverter module 110 is housed in the internal space 80a of the case. The case 80 protects the components of the inverter module 110 and other parts housed in the internal space 80a from vibrations and shocks that occur as the electric vehicle is running.

[0014] The inverter module 110 is a circuit unit that controls the rotational speed and torque of the motor generator. The inverter module 110 consists of a power module 20a, a laminated cooler 30, a leaf spring 50, and a reinforcing plate 60, etc.

[0015] The power module 20a forms at least a part of the power conversion circuit 10. The power conversion circuit 10 includes a plurality (2) of inverter circuits 10i. The inverter circuit 10i is a drive circuit that converts the input DC power into three-phase AC power and drives the motor generator. The power conversion circuit 10 is electrically connected to two motor generators, and the two inverter circuits 10i control the two motor generators individually. One inverter circuit 10i includes three power modules 20a. The power conversion circuit 10 may further include a boost converter that increases the voltage of the traction battery, and a DC-DC converter that steps down the power supply voltage to the charging voltage of the auxiliary battery. The power module 20a is a heating element 20 that generates heat in conjunction with the operation of the power conversion circuit 10, including the inverter circuits 10i.

[0016] The power module 20a has multiple (two) switching elements 21. The switching elements 21 are composed of transistors and free-wheeling diodes (FWDs), etc. The transistors are MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) and IGBTs (Insulated Gate Bipolar Transistors), etc. The power module 20a is a power card formed in a plate shape by resin molding the two switching elements 21 and heat sinks soldered to both sides of each switching element 21.

[0017] The stacked cooler 30 includes a plurality (eight) of cooling plates 31. The cooling plates 31 are formed as long plates from a lightweight and highly heat-dissipating metal material such as an aluminum alloy. The plurality of cooling plates 31 are stacked in the stacking direction SH. The stacking direction SH is a direction substantially perpendicular to both plate surfaces of the cooling plates 31. On the other hand, the directions along both plate surfaces of the cooling plates 31 are the longitudinal direction NH and the short direction TH. The longitudinal direction NH and the short direction TH are perpendicular to each other. The cooling plates 31 have partition walls 32 and connecting portions 34.

[0018] The partition walls 32 are formed on both sides of the cooling plate 31. The partition walls 32 are wall surfaces oriented perpendicular to the axis along the stacking direction SH. The partition walls 32 form a refrigerant flow path 33 inside the cooling plate 31. The refrigerant flow path 33 is a fluid flow path that extends along the longitudinal direction NH of the cooling plate 31. The refrigerant flow path 33 circulates a refrigerant that cools the heat-generating element 20 (power module 20a). For example, coolant liquid (cooling water) flows as the refrigerant in the refrigerant flow path 33.

[0019] The connecting part 34 is formed in a flat cylindrical shape. The connecting part 34 is provided in a posture with its axial direction along the stacking direction SH and is located at both end portions of the partition wall 32 in the longitudinal direction NH. The connecting part 34 provided on one cooling plate 31 is connected to the connecting part 34 provided on another cooling plate 31. The connecting part 34 liquid-tightly connects the refrigerant flow path 33 of one cooling plate 31 to the refrigerant flow path 33 of another cooling plate 31. In other words, the refrigerant flow paths 33 of the plurality of cooling plates 31 are connected to each other via the connecting part 34.

[0020] The cooling plate 31 (hereinafter referred to as the connection plate 31a) located on the outermost side (side wall 81 side) in the stacking direction SH has an inlet pipe 36 and an outlet pipe 37. The inlet pipe 36 and the outlet pipe 37 are formed in a cylindrical shape. The inlet pipe 36 and the outlet pipe 37 are connected to both end portions of the partition wall 32 (hereinafter referred to as the end-side partition wall 32e) facing the opening 86 in a posture with their axial direction along the stacking direction SH. The inlet pipe 36 and the outlet pipe 37 extend from the case inner space 80a to the outside of the case 80 through the opening 86 provided in the side wall 81. The inlet pipe 36 introduces the refrigerant supplied to each refrigerant flow path 33 from the outside of the power conversion device 100. The outlet pipe 37 discharges the refrigerant flowing through each refrigerant flow path 33 to the outside of the power conversion device 100.

[0021] The cooling plate 31 (hereinafter referred to as the terminal plate 31b) located on the opposite side of the connection plate 31a in the stacking direction SH has a holding part 38 together with the connection plate 31a. The holding part 38 extends outward along the longitudinal direction NH from both edges of the cooling plate 31. At least four holding parts 38 are provided on the stacked cooler 30. The holding part 38 fixes the stacked cooler 30 housed in the case inner space 80a to the case 80. As an example, each holding part 38 is held on the bottom wall 85 of the case 80 by a fastening member 39 such as a bolt with a hole. <00,00094>

[0022] The stacked cooler 30 partitions a plurality of accommodation spaces 40 between the refrigerant flow paths 33 formed in each cooling plate 31. The accommodation space 40 is a flat space sandwiched by two adjacent cooling plates 31 in the stacking direction SH. In the stacked cooler 30, a plurality (six) of module accommodation spaces 41 and at least one spring accommodation space 43 are provided as the accommodation spaces 40.

[0023] The module accommodation space 41 is the accommodation space 40 that houses the power module 20a. Three accommodation spaces 40 arranged continuously in the stacking direction SH form the module accommodation space 41 that houses the three power modules 20a included in one inverter circuit 10i. The partition wall 32 (hereinafter, the cooling partition wall 32c) that partitions the module accommodation space 41 is in direct or indirect contact with one plate surface of the power module 20a facing in the stacking direction SH. The cooling partition wall 32c transfers the heat of the power module 20a to the refrigerant in the refrigerant flow path 33.

[0024] The spring accommodation space 43 is the accommodation space 40 that houses the leaf spring 50 and the reinforcing plate 60. The spring accommodation space 43 is located at the center of the plurality of accommodation spaces 40 arranged in the stacking direction SH. Power modules 20a are housed in the accommodation spaces 40 located on both sides of the spring accommodation space 43 in the stacking direction SH. The spring accommodation space 43 is located between two power modules 20a belonging to different inverter circuits 10i and separates the two inverter circuits 10i. The partition wall 32 (hereinafter, the pressing partition wall 32p) that partitions the spring accommodation space 43 is in direct or indirect contact with the reinforcing plate 60. The pressing partition wall 32p receives a force from the reinforcing plate 60 that expands the spring accommodation space 43 outward along the stacking direction SH.

[0025] The leaf spring 50 is an elastic member made by processing a metal plate, such as a spring steel with excellent fatigue resistance, into a corrugated shape. The leaf spring 50 has a longitudinal plate shape and is curved in only one direction. The leaf spring 50 is housed in the spring housing space 43 with the curved direction aligned with the longitudinal direction NH. The leaf spring 50 is housed in the spring housing space 43 in a compressed state in the thickness direction. The leaf spring 50 has a plurality of pressing portions 53. The pressing portions 53 are the peaks of the corrugated curve and are in line contact with the reinforcing plate 60. The leaf spring 50 is supported by the reinforcing plate 60 by the frictional force generated between the pressing portions 53 and the reinforcing plate 60 in the longitudinal direction NH and the transverse direction TH. In other words, there is no configuration to fix the leaf spring 50 to the laminated cooler 30. The leaf spring 50 applies a restoring force along the stacking direction SH to the cooling plates 31 on both sides that partition the spring housing space 43 via the reinforcing plate 60.

[0026] The reinforcing plate 60 is a rectangular plate-shaped member formed from a hard material such as metal. The material of the reinforcing plate 60 may be the same as that of the cooling plate 31, or it may be different from that of the cooling plate 31. For example, the reinforcing plate 60 is formed from a material with a higher Young's modulus than that of the cooling plate 31, such as steel. One reinforcing plate 60 is provided on each side of the leaf spring 50 in the stacking direction SH. The reinforcing plate 60 is housed together with the leaf spring 50 in the spring housing space 43. The reinforcing plate 60 is positioned between the leaf spring 50 and the pressing compartment wall 32p that divides the spring housing space 43. The reinforcing plate 60 distributes the restoring force (spring load) input from the pressing part 53 and applies it to the pressing compartment wall 32p. The reinforcing plate 60 reduces the surface pressure generated on the pressing compartment wall 32p by the spring load and suppresses the deformation of the pressing compartment wall 32p.

[0027] Next, the details of the process for assembling the inverter module 110 will be explained based on Figure 2. The assembly process for the inverter module 110 involves the following steps in order: a preliminary assembly step, a storage step, a compression step, and a fixing step.

[0028] In the preliminary assembly process, multiple cooling plates 31 are arranged along the stacking direction SH (see upper part of Figure 2). The connecting parts 34 of each cooling plate 31 are connected to each other in the preliminary assembly state. At this time, the width of the housing space 40 in the stacking direction SH is sufficiently large compared to the thickness of the power module 20a. The holding parts 38 of the connecting plates 31a connected to the inlet pipe 36 and outlet pipe 37 are fixed to the bottom wall 85 of the case 80 by fastening members 39. In contrast, the holding parts 38 of the end plates 31b are not fixed. As a result, the stacked cooler 30 is fixed at only one end of its two ends.

[0029] In the storage process, one power module 20a is inserted into each module storage space 41. In addition, a leaf spring 50 and two reinforcing plates 60 are inserted into the spring storage space 43. The power modules 20a, leaf springs 50, and reinforcing plates 60 are positioned within each storage space 40. The insertion order of the power modules 20a, leaf springs 50, and reinforcing plates 60 may be changed as appropriate.

[0030] In the compression process, a compressive force CF is applied to the end plate 31b along the stacking direction SH. The compressive force CF is also transmitted to the cooling plates 31 other than the end plate 31b via the connecting portion 34. Each connecting portion 34 fits together due to the compressive force CF. As a result, the width of each housing space 40 is reduced (see Figure 2, lower panel). This causes both plate surfaces of the power module 20a to be in close contact with the cooling compartment wall 32c. In addition, the leaf spring 50 is compressed in the thickness direction by the pressing compartment walls 32p on both sides and the reinforcing plate 60.

[0031] In the fixing process, the retaining portion 38 of the other end plate (end plate 31b), which was not fixed, is fixed to the case 80 by the fastening member 39. As a result, the distance between the cooling plates 31 at both ends, which have the retaining portion 38, becomes fixed. Consequently, the leaf spring 50 is compressed to a predetermined thickness between the two reinforcing plates 60. The leaf spring 50 applies a restoring force (spring load) directed outward in the stacking direction SH to the pressing compartment wall 32p. As the spring load of the leaf spring 50 is transmitted to each cooling plate 31, each cooling compartment wall 32c is pressed against each power module 20a.

[0032] (Summary of the first embodiment) In the first embodiment described above, a leaf spring 50 housed in a spring housing space 43 partitioned within the stacked cooler 30 applies a force SH in the stacking direction to the cooling plate 31. In this structure, where the leaf spring 50 is placed inside the stacked cooler 30, a member to support the pressing member is unnecessary compared to a structure where the pressing member is placed outside the stacked cooler 30. As a result, the case 80 housing the stacked cooler 30 can be made smaller.

[0033] In addition, if the case 80 can be made smaller, the mountability of the power converter 100 on electric vehicles may improve. Furthermore, if the member supporting the pressing member is not required, the power converter 100 can be made lighter and its structure can be simplified.

[0034] Furthermore, in a structure in which a pressing member is placed outside the stacked cooler 30, the stacked cooler 30 is held in place by the case 80 using friction between the pressing member and its support member. Therefore, it can be difficult to ensure sufficient vibration resistance and shock resistance. In contrast, if the leaf spring 50 is placed inside the stacked cooler 30, the stacked cooler 30 can be firmly fixed to the case 80. As a result, it becomes easier to ensure vibration resistance and shock resistance of the power converter 100.

[0035] In addition, in the first embodiment, a power module 20a having a switching element 21 is included in a plurality of heating elements 20. The power modules 20a are housed in module housing spaces 41 located on both sides of the spring housing space 43 in the stacking direction SH. By providing the spring housing space 43 between the two module housing spaces 41 in this way and widening the distance between adjacent power modules 20a, the superposition of surges associated with switching operations can be suppressed.

[0036] In particular, by increasing the distance between the two power modules 20a belonging to different inverter circuits 10i, surge superposition between the two inverter circuits 10i can be suppressed. Furthermore, by suppressing surge superposition between the two power modules 20a, switching operation can be accelerated while avoiding voltage overload due to surge interference. As a result, losses in switching operation can be suppressed, enabling higher efficiency and thus reducing the element area of ​​the switching element. Consequently, the inverter module 110, the case 80, and ultimately the power converter 100 can be miniaturized.

[0037] In the first embodiment, a reinforcing plate 60 is placed between the leaf spring 50 and the cooling plate 31 that partitions the spring housing space 43. Therefore, the spring load of the leaf spring 50 is distributed by the surface pressure of the reinforcing plate 60 and transmitted to the pressing compartment wall 32p. As a result, deformation of the cooling plate 31 due to the spring load is suppressed. Consequently, the spring load is effectively transmitted to each cooling plate 31, allowing the power module 20a and the cooling compartment wall 32c to adhere more securely.

[0038] In the first embodiment described above, the cooling plate 31 corresponds to the "fluid cooler," the refrigerant flow path 33 corresponds to the "fluid flow path," and the spring housing space 43 corresponds to the "pressure space." Furthermore, the leaf spring 50 corresponds to the "pressure member," the reinforcing plate 60 corresponds to the "reinforcing member," and the case 80 corresponds to the "case body."

[0039] (Second embodiment) The second embodiment of this disclosure is a modification of the first embodiment. In the second embodiment, the grid spring 250 shown in Figure 3 is used as a component corresponding to the leaf spring 50 in the first embodiment. The configuration of the inverter module 110 of the second embodiment will be described below based on Figure 3, with reference to Figure 1. In the second embodiment, the reinforcing plate 60 may be omitted, and the spring load of the grid spring 250 may be directly input to the pressing compartment wall 32p.

[0040] The grid spring 250 is a sheet-like elastic member in which numerous small leaf spring sections are arranged two-dimensionally. The grid spring 250 is formed from spring steel or the like. The grid spring 250 has a base 251 and a plurality of pressing sections 253. The base 251 is formed in the shape of a plate or frame and supports the plurality of pressing sections 253. The plurality of pressing sections 253 are regularly arranged in two dimensions, such as in a grid, while being supported by the base 251. Each pressing section 253 protrudes in the thickness direction relative to the base 251. The grid spring 250 is housed in the spring housing space 43 in a position where the arrangement surface of the pressing sections 253 is aligned with the pressing section wall 32p (longitudinal direction NH and transverse direction TH). The grid spring 250 applies the restoring force from the plurality of pressing sections 253 to multiple locations on the pressing section wall 32p.

[0041] In the second embodiment described above, the same effects as in the first embodiment are achieved, and the structure in which the grid spring 250 is placed inside the stacked cooler 30 makes it possible to miniaturize the case 80 that houses the stacked cooler 30.

[0042] In addition, in the second embodiment, a restoring force is applied to multiple locations by a plurality of pressing portions 253 arranged in a two-dimensional manner and protruding from the base portion 251. With this structure, in which the spring load applied to the pressing compartment wall 32p is distributed to multiple locations, deformation of the cooling plate 31 due to the spring load can be suppressed. As a result, the spring load is effectively transmitted to each cooling plate 31, and the power module 20a and the cooling compartment wall 32c can be made to adhere more securely. In the second embodiment described above, the grid spring 250 corresponds to the "pressing member".

[0043] (Third embodiment) The third embodiment of this disclosure shown in Figure 4 is another modification of the first embodiment. In the inverter module 110 of the third embodiment, the configuration of the power conversion circuit 10 and the stacked cooler 30 differs from that of the first embodiment.

[0044] The power conversion circuit 10 has a configuration that includes only one inverter circuit 10i. Corresponding to this configuration of the power conversion circuit 10, the stacked cooler 30 has three module housing spaces 41 and one spring housing space 43 formed as housing spaces 40. Three housing spaces 40 that are continuous from the connection plate 31a side are module housing spaces 41. On the other hand, one housing space 40 on the end plate 31b side is the spring housing space 43.

[0045] In the stacked cooler 30, the thickness of the pressure compartment wall 32p that partitions the spring housing space 43 is different from the thickness of the cooling compartment wall 32c that partitions the module housing space 41. Specifically, the thickness of the pressure compartment wall 32p is greater than that of the cooling compartment wall 32c. As a result, the bending rigidity of the pressure compartment wall 32p is higher than that of the cooling compartment wall 32c.

[0046] In the third embodiment described above, the same effects as in the first embodiment are achieved, and the structure in which the leaf spring 50 is placed inside the stacked cooler 30 makes it possible to miniaturize the case 80 that houses the stacked cooler 30.

[0047] In addition, in the third embodiment, the thickness of the pressing compartment wall 32p is greater than the thickness of the other cooling compartment walls 32c. Therefore, deformation of the pressing compartment wall 32p due to spring load is suppressed. As a result, the spring load along the stacking direction SH is effectively transmitted to the other cooling plates 31, so that the power module 20a and the cooling compartment walls 32c can be more securely in contact.

[0048] In the third embodiment described above, the cooling compartment wall 32c corresponds to the "normal compartment wall." Furthermore, of the two pressing compartment walls 32p located on either side of the leaf spring 50, the thickness of only one of the pressing compartment walls 32p may be greater than the thickness of the cooling compartment wall 32c. In this modified example, a reinforcing plate 60 may be placed between the other pressing compartment wall 32p and the leaf spring 50.

[0049] (Fourth embodiment) The fourth embodiment of this disclosure, shown in Figure 5, is a modification of the third embodiment. The power converter 100 of the fourth embodiment includes a frame 480 instead of the case 80 (see Figure 1) of the first embodiment. In addition, the configuration of the stacked cooler 30 differs from that of the third embodiment. The configurations of the frame 480 and the stacked cooler 30 will be described in order below.

[0050] The frame 480 is formed from a metal material such as an aluminum alloy. The frame 480 has side walls 81 to 83 and has a frame-like shape overall. The frame 480 has side walls 81 to 83 that demarcate the internal space 480a that houses the inverter module 110. An opening 86 and a support wall portion 87 are formed in one of the side walls 81.

[0051] In the stacked cooler 30, the end partition wall 32e of the connecting plate 31a is pressed against the contact support surface 88 of the support wall portion 87, and the holding portion 38 of the end plate 31b is fixed to the end faces of each side wall 82, 83 by the holding portion 38. As a result, the distance between the connecting plate 31a and the end plate 31b is fixed to a constant length.

[0052] In the stacked cooler 30, thickened portions 32t are provided on the two pressing compartment walls 32p that partition the spring housing space 43. The thickened portions 32t are the parts that receive the restoring force of the leaf spring 50 when they come into contact with the pressing portion 53. The thickness of the thickened portions 32t is greater than the thickness of the normal portions 32n of the pressing compartment wall 32p excluding the thickened portions 32t.

[0053] In the fourth embodiment described so far, the same effects as in the third embodiment are achieved, and the structure in which the leaf spring 50 is placed inside the stacked cooler 30 makes it possible to miniaturize the case 80 that houses the stacked cooler 30.

[0054] In addition, in the fourth embodiment, the thickness of the thickened portion 32t is greater than the thickness of the other normal portions 32n. Therefore, an increase in local deformation of the portion of the pressing compartment wall 32p that comes into contact with the pressing portion 53 is suppressed. As a result, the spring load applied to the cooling plate 31 having the pressing compartment wall 32p is effectively transmitted to the other cooling plates 31, so that the power module 20a and the cooling compartment wall 32c can be in closer contact.

[0055] In the fourth embodiment described above, the thickened portion 32t corresponds to the "input portion," and the frame 480 corresponds to the "case body." Furthermore, the thickened portion 32t may be provided on only one of the two pressing compartment walls 32p located on either side of the leaf spring 50. In this modified example, a reinforcing plate 60 may be placed between the other pressing compartment wall 32p and the leaf spring 50.

[0056] (Other embodiments) Although several embodiments of this disclosure have been described above, this disclosure is not to be construed as being limited to the above embodiments, and can be applied to various embodiments and combinations without departing from the spirit of this disclosure.

[0057] The power conversion circuit 10 in the above embodiment included one or two inverter circuits 10i. However, the configuration of the power conversion circuit 10 may be changed as appropriate. Furthermore, the number of heat-generating elements 20 and housing spaces 40 included in the inverter module 110 may also be changed as appropriate to match the configuration of the power conversion circuit 10. In addition, the order in which the module housing space 41 and spring housing space 43 are arranged in the stacking direction SH may also be changed as appropriate.

[0058] Specifically, in the modified embodiments 1 and 2 described above, the power conversion circuit 10 includes two-phase boost circuits connected in parallel with each other and two sets of inverter circuits 10i. In these modified embodiments 1 and 2, eight power modules 20a are provided on the inverter module 110 as heating elements 20.

[0059] The stacked cooler 30 of the modified example 1 partitions eight module housing spaces 41 and one spring housing space 43. The spring housing space 43 is located between the module housing space 41 that houses a power module 20a operating as a boost circuit and the module housing space 41 that houses a power module 20a operating as an inverter circuit 10i.

[0060] Furthermore, the stacked cooler 30 of the modified example 2 forms eight module housing spaces 41 and two spring housing spaces 43. The first spring housing space 43 is located between two module housing spaces 41 that house power modules 20a belonging to different inverter circuits 10i. The second spring housing space 43 is located between a module housing space 41 that houses a power module 20a operating as a boost circuit and a module housing space 41 that houses a power module 20a operating as an inverter circuit 10i, similar to the modified example 1.

[0061] Furthermore, in the modified embodiment 3 described above, the power conversion circuit 10 includes a two-phase boost circuit but does not include an inverter circuit 10i. In this modified embodiment 3, the stacked cooler 30 divides two module housing spaces 41 that are arranged continuously in the stacking direction SH, and one spring housing space 43 located to the side of the module housing spaces 41.

[0062] In the inverter module 110 of the modified examples 1 to 3, it is desirable not to provide a spring housing space 43 between the module housing spaces 41 that house the two power modules 20a belonging to the boost circuit. Also, in the modified examples 1 to 3, circuit elements different from the power modules 20a, specifically reactors and capacitors, may be housed in the housing space 40 as heat-generating elements 20. Furthermore, a power controller that controls the power conversion circuit 10, which includes at least one of the boost circuit and the inverter circuit 10i, may be provided in the power conversion device 100.

[0063] In the stacked cooler 30, the configuration of the connecting portion 34 that connects adjacent cooling plates 31 to each other may be modified as appropriate. The connecting portion 34 may be configured to fit together through radial elastic or plastic deformation due to a compressive force CF. Alternatively, the connecting portion 34 may be configured so that one is press-fitted into the other by a compressive force CF.

[0064] Unlike the heating element 20, the pressing member is a non-heating member that does not operate as part of the power conversion circuit 10. The pressing member is more easily deformable (lower Young's modulus) than the heating element 20 in the stacking direction SH, and the amount of deformation it can withstand in the stacking direction SH is greater than that of the heating element 20. Such pressing members are not limited to the leaf spring 50 and grid spring 250 of the above embodiment. The shape, type, and material of the pressing member may be changed as appropriate.

[0065] For example, in the modified embodiment 4 described above, a plurality of coil springs arranged in a two-dimensional manner are housed in the spring housing space 43 in a position where their axial direction is aligned with the stacking direction SH. The plurality of coil springs apply a restoring force along the stacking direction SH to the pressing compartment wall 32p. Furthermore, non-metallic pressing members such as rubber, elastomer, and polyurethane, formed in a plate shape, may be housed in the spring housing space 43 in a state of compression in the thickness direction.

[0066] In the stacked cooler 30, the cooling fluid used to cool the heat-generating element 20 may be changed as appropriate. The stacked cooler 30 may be configured to circulate fluids such as oil, fluorocarbon-based refrigerants, air, and Freon through the refrigerant flow path 33.

[0067] The electric vehicle equipped with the power converter 100 according to this disclosure may be a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV). Furthermore, the power converter 100 may be installed in a fuel cell vehicle (FCEV) as an FDC (Fuel cell DC-DC Converter).

[0068] Furthermore, electric vehicles equipped with the power converter 100 are not limited to typical POVs (Personally Owned Vehicles) intended for personal ownership. The power converter 100 may be installed in rental cars, manned taxis, ride-sharing vehicles, freight vehicles, and buses, etc. In addition, the power converter 100 may be installed in unmanned vehicles used in mobility services, construction machinery, agricultural machinery, railway vehicles, trams, and DMVs (Dual Mode Vehicles), etc. The power converter 100 may also be installed in ships and electric aircraft such as drones and eVTOLs. Furthermore, the power converter 100 may be configured as a stationary unit, not mounted on a mobile vehicle, and installed in facilities that consume electricity.

[0069] In this disclosure, the term "connected" may mean that an element is directly connected to another element, or indirectly connected through an intermediary element. Similarly, the term "adjacent" may mean that an element is directly adjacent to another element without an intermediary element, or indirectly adjacent through an intermediary element.

[0070] The control unit and method described herein may be implemented by a dedicated computer comprising a processor programmed to perform one or more functions embodied by a computer program. Alternatively, the apparatus and method described herein may be implemented by a dedicated hardware logic circuit. Alternatively, the apparatus and method described herein may be implemented by one or more dedicated computers comprising a combination of a processor that executes a computer program and one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by the computer on a computer-readable non-transitional tangible recording medium.

[0071] (Disclosure of technical ideas) This specification discloses several technical concepts, as listed in the following paragraphs. Some paragraphs are written in a multiple dependent form, where subsequent paragraphs optionally refer to preceding paragraphs. Furthermore, some paragraphs are written in a multiple dependent form, referring to other multiple dependent forms. These paragraphs written in multiple dependent forms define several technical concepts.

[0072] (Technical thought 1) A stacked cooler (30) includes a plurality of fluid coolers (31) stacked in the stacking direction (SH), and partitions a plurality of containment spaces (40) between the fluid flow paths (33) formed in each of the fluid coolers, A case body (80, 480) housing the aforementioned stacked cooler, A plurality of heating elements (20) that form at least a part of the power conversion circuit (10), generate heat in conjunction with the operation of the power conversion circuit, and are housed in the housing space, A pressing member (50, 250) is housed in a pressing space (43), which is at least one of the aforementioned housing spaces, and applies a restoring force along the stacking direction to the fluid cooling body that partitions the pressing space, A power conversion device equipped with the following features. (Technical thought 2) The multiple heating elements include a power module (20a) having a switching element (21), The power conversion device according to technical concept 1, wherein the power modules are housed in the accommodation spaces located on both sides of the pressing space in the stacking direction. (Technical Thought 3) The power conversion device according to technical concept 1 or 2 further comprises a reinforcing member (60) disposed between the pressing member and the fluid cooling body that partitions the pressing space. (Technical Thought 4) The pressing member is, Base (251), It has a plurality of pressing portions (253) arranged in a two-dimensional manner and protruding from the base in the stacking direction, A power conversion device according to any one of the technical concepts 1 to 3, wherein the restoring force is applied to multiple locations by multiple pressing parts. (Technical Thought 5) The power conversion device according to any one of the technical concepts 1 to 4, wherein the thickness of the pressing partition wall (32p) that partitions the pressing space is greater than the thickness of the normal partition wall (32c) that partitions the other accommodation spaces excluding the pressing space. (Technical Thought 6) A power conversion device according to any one of the technical concepts 1 to 4, wherein the plate thickness of the input portion (32t) to which the restoring force of the pressing member is input in the pressing partition wall (32p) that partitions the pressing space is greater than the plate thickness of the portion of the pressing partition wall excluding the input portion. [Explanation of symbols]

[0073] 10 Power conversion circuit, 10i Inverter circuit, 20 Heating element, 20a Power module, 21 Switching element, 30 Stacked cooler, 31 Cooling plate (fluid cooler), 32c Cooling compartment wall (normal compartment wall), 32p Pressing compartment wall, 32t Thickened section (input section), 33 Refrigerant flow path (fluid flow path), 40 Housing space, 43 Spring housing space (pressure space), 50 Leaf spring (pressure member), 250 Grid spring (pressure member), 251 Base, 53, 253 Pressing section, 60 Reinforcement plate (reinforcement member), 80 Case (case body), 480 Frame (case body), 100 Power conversion device, 110 Inverter module, SH Stacking direction

Claims

1. A stacked cooler (30) includes a plurality of fluid coolers (31) stacked in the stacking direction (SH), and partitions a plurality of containment spaces (40) between the fluid flow paths (33) formed in each of the fluid coolers, A case body (80, 480) housing the aforementioned stacked cooler, A plurality of heating elements (20) that form at least a part of the power conversion circuit (10), generate heat in conjunction with the operation of the power conversion circuit, and are housed in the housing space, A pressing member (50, 250) is housed in a pressing space (43), which is at least one of the aforementioned housing spaces, and applies a restoring force along the stacking direction to the fluid cooling body that partitions the pressing space, A power conversion device equipped with the following features.

2. The plurality of heating elements include a power module (20a) having a switching element (21), The power conversion device according to claim 1, wherein the power modules are housed in the housing spaces located on both sides of the pressing space in the stacking direction.

3. The power conversion device according to claim 1, further comprising a reinforcing member (60) disposed between the pressing member and the fluid cooling body that partitions the pressing space.

4. The pressing member is, Base (251) and, It has a plurality of pressing portions (253) arranged in a two-dimensional manner and protruding from the base in the stacking direction, The power conversion device according to claim 1, wherein the restoring force by the multiple pressing parts is applied to multiple locations.

5. The power conversion device according to claim 1, wherein the thickness of the pressing partition wall (32p) that partitions the pressing space is greater than the thickness of the normal partition wall (32c) that partitions the other accommodation spaces excluding the pressing space.

6. The power conversion device according to claim 1, wherein the plate thickness of the input portion (32t) of the pressing partition wall (32p) that partitions the pressing space is greater than the plate thickness of the portion of the pressing partition wall excluding the input portion.

7. An inverter module housed in a case (80, 480), A stacked cooler (30) includes a plurality of fluid coolers (31) stacked in the stacking direction (SH), and partitions a plurality of containment spaces (40) between the fluid flow paths (33) formed in each of the fluid coolers, A plurality of heating elements (20) that form at least a part of the inverter circuit (10i), generate heat in conjunction with the operation of the inverter circuit, and are housed in the housing space, A pressing member (50, 250) is housed in a pressing space (43), which is at least one of the aforementioned housing spaces, and applies a restoring force along the stacking direction to the fluid cooling body that partitions the pressing space, An inverter module equipped with the following features.

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