JP6136730B2 - Power converter - Google Patents

Description

  The present invention relates to a power conversion device.

  A vehicle such as an electric vehicle or a hybrid vehicle is equipped with a power conversion device including a structure such as an inverter. And the power converter device is provided with the refrigerant | coolant flow path through which the refrigerant | coolant for cooling the power converter part with much emitted-heat amount distribute | circulates. For example, a power conversion device disclosed in Patent Document 1 includes an inverter including a semiconductor module, a cooler that cools the inverter, a converter that includes electronic components other than the semiconductor module, and a refrigerant channel that cools the converter. . And the said cooler and the said refrigerant | coolant flow path are comprised by the communication part which connects both, and are comprised so that a refrigerant | coolant may distribute | circulate.

JP 2012-210022 A

  However, the communication part is located outside the case that houses the inverter and the converter, and is exposed to the outside. And the connection part of a communicating part and the said cooler and a refrigerant | coolant flow path is sealed in order to prevent the leakage of a refrigerant | coolant, and between the communicating part and a case is also sealed in order to ensure the watertightness of the said case. . When the power converter is handled, since the communication part is exposed, there is a possibility that some interference may occur between the communication part and the outside, such as an operator touching the communication part. In this case, there is a possibility that a load is applied to the seal portion between the communication portion and the cooler and the refrigerant flow path, and the seal portion between the communication portion and the case, and the sealing performance of both seal portions may be reduced. is there. Further, since the seal portion is provided between the communication portion and the cooler and the refrigerant flow path, and between the communication portion and the case, the number of seal portions is relatively large. Therefore, it is structurally disadvantageous in securing the sealing performance as the entire apparatus.

  Therefore, it is conceivable that the communication portion is configured to be housed inside the case to prevent interference between the communication portion and the outside, and the seal portion may be relatively small. However, if the communication part is housed in the case and a cooling system comprising a refrigerant flow path, a cooler, and the communication part is provided in the case, in the cooling system, some sort of abnormality occurs, If the internal pressure of the cooling system rises excessively, for example, because the refrigerant flow is hindered, there is a risk that the refrigerant leaks to the inside of the case due to damage to the seals etc. in the cooling system in the case. is there. In this case, the leaked refrigerant may come into contact with a high-voltage circuit unit such as a semiconductor module in the case, thereby causing a short circuit.

  The present invention has been made in view of such problems, and in the unlikely event that the internal pressure rises excessively in the cooling system in the case, the electric power that prevents the refrigerant from leaking inside the case. A conversion device is to be provided.

One embodiment of the present invention is a semiconductor module;
A cooler for cooling the semiconductor module;
A case in which the semiconductor module and the cooler are housed inside, and a recess that is open to the outside is formed;
A lid that is attached to the case so as to cover the opening side of the recess, and forms a coolant channel with the recess;
A communication portion that is provided in the case and connected to the cooler and the refrigerant flow path to communicate with each other;
With
The cooler, the refrigerant flow path, and the communication portion constitute a cooling system in communication with each other so that the refrigerant flows.
A seal portion that seals between the case and the lid portion is formed, and a low strength portion having the lowest seal strength in the cooling system is formed in the seal portion. In the converter.

  In the power conversion device, a cooler for cooling the semiconductor module housed in the case is provided, and a refrigerant flow path is provided between the case and the lid that closes the recess that opens to the outside of the case. Is formed. The case is provided with a communication portion connected to each of the cooler and the refrigerant flow path, and the cooler, the refrigerant flow path and the communication portion are configured to communicate with each other so that the refrigerant flows, thereby forming a cooling system. Yes. A low-strength portion having the lowest seal strength in the cooling system is formed in the seal portion that seals between the lid portion and the case. As a result, in the unlikely event that an abnormality occurs and the refrigerant flow in the cooling system is obstructed, and the internal pressure of the cooling system rises excessively, the low-strength part is damaged first, and the low strength The refrigerant will leak from the part. And since the said low intensity | strength part is formed in the seal part between the cover part and the case which block | close the recessed part opened on the outer side of a case, a refrigerant | coolant leaks from the said low intensity | strength part to the outer side of a case, The refrigerant is prevented from leaking inward.

  As described above, according to the present invention, there is provided a power conversion device that prevents the refrigerant from leaking inside the case even if the internal pressure is excessively increased in the cooling system in the case. be able to.

The longitudinal cross-sectional view of the power converter device in Example 1. FIG. The bottom view of the power converter device in Example 1. FIG. The bottom view of the power converter device in Example 2. FIG. FIG. 4 is a partially enlarged view of FIG. 3. The partial bottom enlarged view of the power converter device in a modification. The lower part partial enlarged view of the power converter device in the further modification. The partial bottom enlarged view of the power converter device in Example 3. FIG. The side surface partial enlarged view of the power converter device in Example 3. FIG.

  The power converter of the present invention can be used for electric vehicles and hybrid vehicles.

Example 1
The power conversion device of this example will be described with reference to FIGS.
The power conversion device 1 of this example includes a semiconductor module 11, a cooler 12 that cools the semiconductor module 11, the semiconductor module 11 and the cooler 12 inside, and a recess 33 that opens to the outside. A case 30.
A lid 40 is attached to the case 30 so as to cover the opening side of the recess 33. A coolant channel 20 is formed between the recess 33 and the lid 40.
Further, in the case 30, a communication part 50 connected to the cooler 12 and the refrigerant flow path 20 and communicating both is provided.
The cooler 12, the refrigerant flow path 20, and the communication portion 50 communicate with each other so that the refrigerant circulates, thereby forming a cooling system 60.
A seal portion 41 that seals between the case 30 and the lid portion 40 is formed, and a low strength portion 44 having the lowest seal strength in the cooling system 60 is formed in the seal portion 41.

  As shown in FIGS. 1 and 2, the case 30 includes a first case 31 and a second case 32. The first case 31 includes a bottom 31a having a rectangular flat plate shape, four side walls 31b erected along the outer edge thereof, and a case lid 31c provided on the opposite side of the bottom 31a. The first case 31 forms a box shape by these, and forms the first storage portion 301 inside thereof.

  As shown in FIG. 1, the first storage unit 301 stores the semiconductor module 11 and the cooler 12. The semiconductor module 11 constitutes a part of the inverter. The cooler 12 includes a cooling pipe 121, a connecting pipe 122, a first refrigerant introduction pipe 123, and a first refrigerant discharge pipe 124. A plurality of semiconductor modules 11 and cooling pipes 121 are provided, and are stacked alternately along the X direction (stacking direction X) to form the stacked body 13. Each cooling pipe 121 is connected and communicated with a connecting pipe 122, and is configured such that a refrigerant flows through the connecting pipe 122. The first refrigerant introduction pipe 123 and the first refrigerant discharge pipe 124 are connected so as to extend in parallel to the stacking direction X of the stacked body 13 in the cooling pipe 121 positioned at one end of the stacked body 13. Yes. The first refrigerant introduction pipe 123 communicates with the outside of the first case 31 and is configured to introduce the refrigerant into the cooling pipe 121, and the first refrigerant discharge pipe 124 flows through the cooling pipe 121 and the communication portion 122. The refrigerant to be discharged is discharged to the second case 32 side described later.

  As shown in FIG. 1, the second case 32 is provided on the bottom 31 a side of the first case 31 so as to overlap in the Z direction perpendicular to the stacking direction X. The second case 32 includes a bottom portion 32a having a rectangular flat plate shape and four side walls 32b erected along the outer edge thereof. The bottom case 31a side of the first case 31 in the second case 32 is open, and the second storage part 302 is provided between the side wall 32b and the bottom parts 31a and 32a by attaching the second case 32 to the bottom part 31a side. Is formed. As shown in FIG. 1, the second storage unit 302 stores electronic components (reactor 211, capacitor 212). Reactor 211 and capacitor 212 are fixed to bottom portion 32a. Although not shown, the reactor 211 and the capacitor 212 are electrically connected to the semiconductor module 11.

As shown in FIG. 1, a recess 33 that opens to the outside of the case 30 (that is, the side opposite to the bottom 31 a) is formed in the bottom 32 a of the second case 32. And the cover part 40 is attached to case 30 (2nd case 32) so that the said recessed part 33 may be covered. Thereby, the coolant channel 20 is formed between the recess 33 and the lid 40.
A second refrigerant introduction pipe 21 and a second refrigerant discharge pipe 22 are connected to the refrigerant flow path 20. The second refrigerant introduction pipe 21 is connected to the first refrigerant discharge pipe 124 of the cooler 12 via the communication part 50 to form a flow path connection part 21a. Thus, the refrigerant discharged from the cooler 12 is configured to be introduced into the refrigerant flow path 20. On the other hand, the second refrigerant discharge pipe 22 is configured to discharge the refrigerant flowing through the refrigerant flow path 20 to the outside of the case 30.

The communication part 50 is a resin-made molded member, and has a tubular shape as shown in FIGS. 1 and 2. The communication portion 50 is disposed in the case 30 so as to straddle the first case 31 and the second case 32 through the hole 34 formed in the bottom portion 31a of the first case 31, and is not illustrated. It is fixed to the first case 31 by a fastening member.
And the cooler 12, the refrigerant | coolant flow path 20, and the communication part 50 are connected so that a refrigerant | coolant may circulate, and the cooling system 60 is comprised by these.

  As shown in FIG. 2, the lid 40 has a rectangular flat plate shape and is slightly smaller than the rectangular outer shape formed by the four side walls 32 b when viewed from the bottom 32 a side of the second case 32. have. The lid 40 is fixed to the case 30 via fixing parts 43, 43a, and 43b to which nine fixing members 42, 42a, and 42b are attached. The fixing members 42, 42 a, and 42 b are bolts that are inserted into holes (not shown) formed in the lid portion 40 so as to be arranged along the edge portion of the lid portion 40. It is concluded. Accordingly, a seal portion 41 that seals between the case 30 and the lid portion 40 is formed so as to extend along an edge portion of the lid portion 40. As shown in FIG. 2, the seal portion 41 is formed along an imaginary line 41 a that connects the fixing portions 43, 43 a, and 43 b arranged adjacent to each other. In the seal portion 41, a seal member (not shown) such as a liquid gasket or an O-ring is interposed between the case 30 and the lid portion 40.

  As shown in FIG. 2, among the nine fixing portions 43, 43 a, 43 b, the distance d <b> 1 between the fixing portion 43 a and the fixing portion 43 b arranged adjacent to each other on one end side of the lid portion 40 is It is larger than the interval d2 between the fixed portions 43 arranged next to each other. In this example, the size of the interval d1 is about twice the size of the interval d2. As a result, in the seal portion 41, the region 44 between the fixed portion 43a and the fixed portion 43b having the interval d1 has a lower seal strength than the region between the other fixed portions 43 having the interval d2, and the cooling system 60 In FIG. 1, the low strength portion 44 having the lowest seal strength is configured.

  In this specification, “seal strength” refers to a mechanical strength that maintains water tightness in the cooling system 60 in order to prevent the refrigerant flowing through the cooling system 60 from leaking from the cooling system 60 to the outside. In the seal portion 41, the strength for bringing the case 30 and the lid portion 40 into close contact with each other or the strength for sandwiching the seal member interposed therebetween is referred to as “seal strength”. In this example, the seal strength at the seal portion 41 is highest at the portion where the fixing portions 43, 43a, 43b to which the fixing members 42, 42a, 42b are fastened, and becomes weaker as the distance from the portion is increased. . Therefore, as described above, the region 44 where the largest gap d <b> 1 is formed in the seal portion 41 is the low strength portion 44.

  As shown in FIG. 2, a standing wall 23 is erected from the bottom 32 a toward the lid 40 in the refrigerant flow path 20 in parallel with the longitudinal direction (X direction). Thereby, the refrigerant | coolant flow path 20 is formed in the U-shape. The refrigerant flow path 20 is provided with a second refrigerant introduction pipe 21 (flow path connection portion 21a) at one end (the side where the low-strength portion 44 is formed) at the other end. And is formed so as to return to the second refrigerant discharge pipe 22 disposed on one end side. Thereby, the low intensity | strength part 44 is formed in the position close | similar to the 2nd refrigerant | coolant inlet tube 21 (flow-path connection part 21a).

  As shown in FIG. 1, the refrigerant is supplied to the cooling pipe 121 at the end on one end side via the first refrigerant introduction pipe 123, flows through the other cooling pipe 121 via the connecting pipe 122, 1 is discharged from the refrigerant discharge pipe 124. As the refrigerant flows through each cooling pipe 121, heat exchange is performed with each semiconductor module 11, and each semiconductor module 11 is cooled. Thereafter, the refrigerant discharged from the first refrigerant discharge pipe 124 is guided to the second refrigerant introduction pipe 21 through the communication portion 50 and introduced into the refrigerant flow path 20, and as indicated by arrows in FIG. It flows through the refrigerant flow path 20. And heat exchange is made between the electronic components (reactor 211, capacitor 212), and these are cooled. Thereafter, the refrigerant flowing through the refrigerant flow path 20 is discharged from the second refrigerant discharge pipe 22 to the outside.

Next, the effect in the power converter device 1 of this example is explained in full detail below.
According to the power conversion device 1, the cooler 12 that cools the semiconductor module 11 accommodated in the case 30 is provided, and the lid 40 and the case 30 that block the recess 33 that opens to the outside of the case 30. The refrigerant flow path 20 is formed between the two. The case 30 is provided with a communication portion 50 that connects and communicates with the cooler 12 and the refrigerant flow path 20, and the cooler 12, the refrigerant flow path 20, and the communication section 50 communicate with each other so that the refrigerant circulates and is cooled. A system 60 is configured. A low strength portion 44 having the lowest seal strength in the cooling system 60 is formed in the seal portion 41 that seals between the lid portion 40 and the case 30. As a result, in the unlikely event that an abnormality occurs and the refrigerant flow is hindered in the cooling system 60 and the internal pressure in the cooling system 60 increases excessively, the low-strength portion 44 is first damaged, The refrigerant will leak from there. And since the low intensity | strength part 44 is formed in the seal | sticker part 41 between the cover part 40 and the case 30 which block | closes the recessed part 33 opened on the outer side of the case 30, a refrigerant | coolant is outside the case 30 from the low intensity | strength part 44. The refrigerant is prevented from leaking to the inside of the case 30.

  Further, the seal portion 41 is provided with a plurality of fixing portions 43, 43a, 43b to which fixing members 42, 42a, 42b for fixing the lid portion 40 and the case 30 are attached. The fixing portions 43, 43a, 43b are The low-strength portion 44 is formed between the pair of adjacent fixing portions 43a and 43b having the largest interval in the seal portion 41, while being arranged along the extending direction of the seal portion 41. . Thereby, the low intensity | strength part 44 can be easily formed with a simple structure.

  In this example, the low-strength portion 44 is formed in the refrigerant flow path 20 at a position close to the second refrigerant introduction tube 21 to which the communication portion 50 is connected. As a result, in the unlikely event that the refrigerant flows into the refrigerant flow path 20 through the second refrigerant introduction pipe 21 in a state where the internal pressure is high from the communication portion 50, the low-strength portion 44 is surely damaged first, Since the refrigerant leaks to the outside of the case 30, leakage of the refrigerant to the inside of the case 30 is more reliably prevented.

  In this example, the refrigerant flows through the refrigerant flow path 20 after flowing through the cooler 12, but is not limited thereto. For example, one end of the communication part 50 is connected to the second refrigerant discharge pipe 22 of the refrigerant flow path 20, and the other end of the communication part 50 is connected to the first refrigerant introduction pipe 123, It is good also as circulating the cooler 12 after circulating a refrigerant | coolant flow path 20. FIG.

  Further, in this example, the case 30 is divided into the first case 31 and the second case 32, but the case 30 in which both are integrally formed is used. It is good.

  As described above, according to the present example, even if the internal pressure rises excessively, for example, if the refrigerant flow is hindered in the cooling system 60 in the case 30, the refrigerant is placed inside the case 30. A power conversion device 1 that is prevented from leaking is provided.

(Example 2)
The power conversion device 1 of this example includes a low-strength portion 440 shown in FIGS. 3 and 4 instead of the low-strength portion 44 (FIG. 1) in the first embodiment. Other components are the same as those in the first embodiment, and the same reference numerals as those in the first embodiment are used in this example, and the description thereof is omitted.

  As shown in FIG. 3, in the seal portion 41, a part of the outer edge of the side wall 32 b of the second case 32 is cut out toward the inside of the recess 33 to form a cutout portion 441. Thereby, as shown in FIG. 4, in the notch 441, the outer edge 41b of the seal | sticker part 41 is adjoining to the virtual line 41a which connects a pair of adjacent fixing | fixed part 43a, 43c. As a result, in the region of the seal portion 41 where the notch 441 is formed, the width w of the seal portion 41 is small, so the contact area between the case 30 and the lid portion 40 is small. Thereby, the low strength portion 440 having the lowest seal strength in the cooling system 60 is formed in the seal portion 41. The low-strength portion 440 also has the same effect as that of the first embodiment.

  Furthermore, as shown in FIG. 4, the low-strength portion 440 is formed in the seal portion 41 at a position where the distance s between the seal portion 41 and the flow path connection portion 21 a is the shortest. As a result, if the refrigerant flows into the refrigerant flow path 20 through the second refrigerant introduction pipe 21 (flow path connection portion 21a) with the internal pressure being high from the communication portion 50, the low-strength portion 440 is surely secured. The refrigerant leaks to the outside of the case 30, so that the refrigerant to the inside of the case 30 is more reliably prevented from leaking.

  In this example, the cutout portion 441 is provided so that the outer edge 41b of the seal portion 41 is close to the imaginary line 41a. However, as shown in FIG. The outer edge 41b of the notch 441 can intersect with the virtual line 41a. As a result, the seal strength of the low strength portion 440 can be further reduced within a range in which the refrigerant does not leak in a normal use state. In this case, if the refrigerant flows into the refrigerant flow path 20 through the second refrigerant introduction pipe 21 in a state where the internal pressure is high from the communication part 50, the low-strength part 440 is more reliably damaged. As the refrigerant leaks to the outside of the case 30, leakage of the refrigerant to the inside of the case 30 can be prevented more reliably.

  Further, in this example, the notch 441 is formed in the case 30 (second case 32), but instead of this, as shown in FIG. The notch portion 442 may be formed by notching. Also in this case, since the width w of the seal portion 41 is small in the region where the notch 442 is formed in the seal portion 41, the contact area between the case 30 and the lid portion 40 is small. Thereby, the low strength portion 440 having the lowest seal strength in the cooling system 60 is formed in the seal portion 41. Even in this case, the same effects as the present example are achieved. In addition, in both case 30 (2nd case 32) and the cover part 40, it is good also as forming so that the notch parts 441 and 442 may overlap in planar view (state seen from the cover part 40 side). In this case, the same effect as this example can be obtained.

  As shown in FIG. 6, a fixing member 401 is provided at a position overlapping the notch 442 in the case 30 (second case 32) when viewed from the lid 40 side. The fixing member 401 is for fixing a member (not shown) to the case 30. By providing the fixing member 401 in the notch 442, the region where the notch 442 is formed can be used effectively, which contributes to downsizing of the entire apparatus.

  In this example, the lid 40 is fixed to the case 30 via the fixing members 42, 42a, 42b, and 42c. Alternatively, the lid 40 may be fixed to the case 30 via an adhesive. Good. In this case, the adhesive can be provided over the entire area of the seal portion 41. In this case, the same effect as this example can be obtained.

(Example 3)
The power conversion device 1 of this example includes a low-strength portion 445 shown in FIGS. 7 and 8 instead of the low-strength portion 44 (FIG. 1) in the first embodiment. Other components are the same as those in the first embodiment, and the same reference numerals as those in the first embodiment are used in this example, and the description thereof is omitted.

  As shown in FIGS. 7 and 8, the lid portion 40 is formed so that the thickness of the lid portion 40 is reduced at a position overlapping the seal portion 41 in plan view (when viewed from the lid portion 40 side). A thin portion 446. In this example, as shown in FIG. 8, the thickness t of the thin portion 446 is a half of the portion of the lid portion 40 where the thin portion 446 is not formed. And since the rigidity of the cover part 40 in the thin part 446 falls by forming the thin part 446, the area | region 445 which overlaps with the thin part 446 in the seal part 41 becomes low in the sealing strength. Yes. Thereby, the low strength portion 445 having the lowest seal strength in the refrigerant system 60 is formed in the seal portion 41. The low strength portion 445 also has the same effect as that of the first embodiment.

DESCRIPTION OF SYMBOLS 1 Power converter 11 Semiconductor module 12 Cooler 121 Cooling pipe 20 Refrigerant flow path 30 Case 40 Lid part 44, 440, 445 Low intensity part 50 Communication part 60 Cooling system

Claims (6)

A semiconductor module (11);
A cooler (12) for cooling the semiconductor module (11);
A case (30) in which the semiconductor module (11) and the cooler (12) are housed, and a recess (33) that is open to the outside is formed;
A lid (40) attached to the case (30) so as to cover the opening side of the recess (33) and forming a coolant channel (20) with the recess (33);
A communication portion (50) provided in the case (30) and connected to the cooler (12) and the refrigerant flow path (20) to communicate with each other;
With
The cooler (12), the refrigerant flow path (20), and the communication part (50) communicate with each other so as to circulate the refrigerant to form a cooling system (60).
A seal portion (41) that seals between the case (30) and the lid portion (40) is formed, and the seal portion (41) has the highest seal strength in the cooling system (60). A low-strength portion (44, 440, 445) is formed in the power converter (1).   The seal portion (41) includes a plurality of fixing portions (43, 43a, 43b) to which fixing members (42) for fixing the lid portion (40) and the case (30) are attached. The fixing portions (43, 43a, 43b) are arranged along the extending direction of the seal portion (41), and the low-strength portion (44) is spaced from each other in the seal portion (41). The power conversion device (1) according to claim 1, wherein the power conversion device (1) is formed between a pair of adjacent fixing portions (43a, 43b) having the largest (d1). The low-strength portion (440) is connected to an imaginary line (41a) in the seal portion (41) where the outer edge (41b) of the seal portion (41) connects the pair of adjacent fixed portions (43a, 43c). At least one of the outer edge of the case (30) and the outer edge of the lid (40) is cut out toward the inside of the recess (33) so as to be close to each other. Item 3. The power conversion device (1) according to Item 2 . The low-strength portion (440) includes an imaginary line (41a) in the seal portion (41) and an outer edge (41b) of the seal portion (41) connecting the pair of adjacent fixed portions (43a, 43c). so as to intersect, claim 2, characterized in that at least one of the outer edge of the outer edge and the cap portion of the case (30) (40) is constituted by notching towards the inside of the recess (33) The power converter device according to (1). The low-strength portions (440, 445) are distances (in the seal portion (41)) between the refrigerant flow passage (20) and the flow passage connection portion (21a) to which the communication portion (50) is connected ( The power conversion device (1) according to any one of claims 1 to 4, wherein s) is formed at the shortest position.   The low-strength portion (445) is formed at a position where the thickness (t) of the lid portion (40) is the thinnest in the seal portion (41). The power converter device (1) according to claim 1.

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