JP2015201564A - On-vehicle electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure which connects the inside and the outside of an inverter (on-vehicle electronic apparatus) and seals a gap between a coolant pipe for feeding a coolant to a cooler within the inverter and an external pipe.SOLUTION: The inverter in which the cooler is provided includes: a case 12 including a through-hole 16; a coolant pipe 23 extending from the cooler through the through-hole 16 to the outside of the case 12; and an external pipe 4 which is fitted with an outer peripheral surface 23a of the coolant pipe 23 outside of the case 12. The inverter also includes a sealant 3 which covers the outer peripheral surface 23a of the coolant pipe 23, seals a gap between the outer peripheral surface 23a of the coolant pipe 23 and an inner peripheral surface 16a of the through-hole 16 and seals a gap between the outer peripheral surface 23a of the coolant pipe 23 and an inner peripheral surface 44a of the external pipe 4. In the sealant 3, a core metal 31 is embedded at a position opposite to the inner peripheral surface 16a of the through-hole 16, and a drain hole 32 penetrating the inner peripheral side and outer peripheral side of the sealant 3 is provided outside of the case 12 rather than the core metal 31.

Description

  The present invention relates to an in-vehicle electronic device. In particular, the present invention relates to an in-vehicle electronic device that includes an electronic component inside and a liquid-cooled cooler that cools the electronic component.

  An electric vehicle is equipped with an electronic device that handles a large amount of power to be supplied to a motor for traveling. A typical example is an inverter that converts DC power of a battery into AC power. Electronic devices that handle large amounts of electricity generate a large amount of heat and are often equipped with liquid-cooled coolers. On the other hand, in-vehicle electronic devices are mounted in the engine compartment, so waterproofness needs to be taken into consideration. In an electronic device equipped with a liquid-cooled cooler, a refrigerant supply pipe that supplies refrigerant to the cooler from the outside and a refrigerant discharge pipe that discharges the refrigerant that has passed through the cooler to the outside pass through the case side wall of the electronic device. Become. A sealing material is inserted between the through hole of the case and the refrigerant supply pipe or the refrigerant discharge pipe to fill the gap between them.

  Patent Documents 1-3 disclose techniques related to the above-described sealing material. Patent Document 1 discloses a technique for improving the efficiency of assembling work for attaching a sealing material.

  The technique of patent document 2 is as follows. The sealing material has a pipe seal portion that contacts the outer peripheral surface of the refrigerant tube and a case seal portion that contacts the case, and they are displaced from each other in the axial direction of the refrigerant tube. Further, a cored bar is embedded in the case seal portion in contact with the case. Since the pipe seal portion and the case seal portion are displaced in the axial direction, the sealing material is also driven when the pipe is inclined, and the sealing performance is maintained. Further, the cored bar prevents deformation of the case seal part and improves the sealing performance between the case and the case. In Patent Document 2, a U-shaped groove is provided in the upper part of the case, and the refrigerant pipe passes through the groove.

  Patent Document 3 discloses that a refrigerant pipe extending from a cooler inside the case is extended to the outside of the case and connected to another refrigerant pipe outside the case. The space between the through hole of the case and the outer periphery of the refrigerant pipe is sealed with a sealing material. Apart from the sealing material, the connecting portion between the refrigerant pipe and the other refrigerant pipe is also sealed with another sealing material outside the case.

JP 2014-003136 A JP 2011-171449 A JP 2012-210022 A

  In the technique of Patent Document 3, a sealing material for sealing between a refrigerant pipe extending from a cooler inside the case and the through hole of the case, and a refrigerant pipe (external pipe) separate from the refrigerant pipe outside the case are sealed. Requires another sealing material to stop. To reduce costs, an external pipe is placed adjacent to the side wall of the case, and a single sealant is provided between the refrigerant pipe extending from the inside of the case to the outside and the inner peripheral surface of the case through hole, and between the refrigerant pipe and the external pipe. It is good that it can be sealed with. However, if two places are simultaneously sealed with one sealing material, the sealing performance may be lowered. The present specification relates to a structure between a refrigerant pipe extending from the inside of a case and an inner peripheral surface of the case through hole, and a structure for simultaneously sealing between the refrigerant pipe and the external pipe. Even when the sealing property between the two is reduced, the sealing property between the refrigerant pipe and the case through hole is maintained, and a technique for preventing water leakage from entering the case is provided.

  One embodiment of the technology disclosed in this specification can be embodied in an in-vehicle electronic device. The electronic device includes an electronic component inside the case and a liquid-cooled cooler that cools the electronic component. The electronic device includes a case, a refrigerant pipe, an external pipe, and a sealing material. The case is provided with a through hole through which a refrigerant pipe extending from an internal cooler passes. The refrigerant pipe is fitted to the outer peripheral surface of the refrigerant pipe outside the case. The external pipe is fitted with the refrigerant pipe while being in contact with the outer surface of the case. The cylindrical sealing material covers the outer peripheral surface of the refrigerant tube, seals between the outer peripheral surface of the refrigerant tube and the inner peripheral surface of the through hole, and also the outer peripheral surface of the refrigerant tube and the inner peripheral surface of the external pipe The space is sealed. A cored bar is embedded in the sealing material at a position facing the inner peripheral surface of the through hole. Further, the sealing material is provided with a drain hole penetrating the inner peripheral side and the outer peripheral side of the sealing material at a position outside the case from the core metal.

  The above-described on-vehicle electronic device enhances the sealing performance between the case through hole and the refrigerant pipe by embedding a cored bar in the sealing material. At the same time, if the sealing performance between the refrigerant pipe and the external pipe deteriorates and water leaks, the leaked water flows from the drain hole to the outside, so that it does not enter the case.

  In this specification, a groove provided in the case and forming a “hole” when the cover is attached to the case is also treated as a through hole for convenience.

  The technology disclosed in this specification relates to a structure that simultaneously achieves sealing between a refrigerant pipe extending from the inside of the case to the outside and the inner peripheral surface of the case through-hole, and sealing between the refrigerant pipe and the external pipe. Even when the sealing performance between the refrigerant pipe and the external pipe is lowered, the leaked water is prevented from entering the case. Details and further improvements of the technology disclosed in this specification will be described in the following “DETAILED DESCRIPTION”.

It is a disassembled perspective view of the vehicle-mounted electronic device (inverter) of an Example. It is a perspective view of an inverter. It is sectional drawing in the III-III line of FIG. FIG. 4 is an enlarged view of a range surrounded by a two-dot chain line IV in FIG. 3. FIG. 5 is an enlarged view of a range surrounded by a two-dot chain line V in FIG. 4. It is a fragmentary sectional view in the VI-VI line of FIG.

  An electronic apparatus according to an embodiment will be described with reference to the drawings. The electronic device according to the embodiment is an inverter 2 that is mounted on an electric vehicle and converts DC power of a battery into AC power and supplies the AC power to a motor. FIG. 1 shows an exploded perspective view of the inverter 2. FIG. 2 is a perspective view of the inverter 2. FIG. 3 is a sectional view taken along line III-III in FIG. Note that the illustration of the cover 13 of the inverter 2 shown in FIG. 3 is omitted in FIGS. The inverter 2 includes a voltage converter circuit that boosts the voltage of the battery and an inverter circuit that converts the boosted DC power into AC power. In order to realize these circuit configurations, the inverter 2 includes a stacked cooling unit 20 that stacks and cools the power card 22 as hardware, a smoothing capacitor 51 that smoothes a large current for driving the motor, and a voltage converter circuit. The reactor 52, the cooler 15 that cools the reactor 52 and the smoothing capacitor 51, and a circuit board are used. The power card 22 is a component molded with a switching element and a diode, and the circuit board is a board on which a control circuit for controlling the switching element is mounted. A transistor such as an IGBT is used as the switching element. Although the circuit board is disposed above the stacked cooling unit 20, its illustration is omitted. Moreover, although the power card 22 (switching element), the smoothing capacitor 51, and the reactor 52 are electrically connected to each other by a metal bus bar, the illustration thereof is omitted in the drawing.

  In the figure, a coordinate system is shown. The XY plane in the coordinate system represents the horizontal plane of the mounting posture of the inverter 2 with respect to the electric vehicle. The Z axis in the coordinate system represents the vertical direction of the mounting posture of the inverter 2 with respect to the electric vehicle. In this specification, the configuration of the embodiment will be described using the coordinate system in a timely manner.

  The inverter 2 has two independent cases (a first case 12 and a second case 14). The first case 12 is for housing units such as the reactor 52 and the stacked cooling unit 20, The case 14 is the cooler 15 itself. The inverter 2 includes two types of coolers, one is a cooler 15 that cools the reactor 52 and the capacitor 51, and the other is integrated with a plurality of power cards 22 that contain switching elements. This is a stacked cooling unit 20. Since the cooler 15 is fixed to the bottom surface of the first case 12, the inverter 2 has a structure in which the cooler is integrated as a whole.

  The stacked cooling unit 20 is formed by alternately stacking a plurality of power cards 22 and a plurality of flat plate-shaped cooling plates 21 through which a refrigerant passes. The cooling plate 21 has a hollow inside and is provided with through holes on both sides in the longitudinal direction (that is, on both sides of the power card 22). The through holes of adjacent cooling plates 21 are connected by a connecting pipe 25. And two refrigerant pipes 23 and 24 extend from the through hole of the cooling plate 21 at the end of the laminated structure. The laminated cooling unit 20 is housed in the first case 12, and the refrigerant pipes 23 and 24 pass through the case through holes 16 and 56 provided in the side wall of the first case 12. The supply pipe 61 that supplies the refrigerant is connected to the refrigerant pipe 24 and the case through hole 56 from the outside of the first case 12. One end of the external connection pipe 4 that connects the cooler 15 and the stacked cooling unit 20 is connected to the refrigerant pipe 23 and the case through hole 16 from the outside of the first case 12. A sealing material 3 is provided between the refrigerant pipe 23, the case through-hole 16, and the external connection pipe 4. The connection structure of the refrigerant pipe 23, the case through-hole 16 and the external connection pipe 4 using the sealing material 3 will be described later. The external connection pipe 4 is a U-shaped pipe, and the other end (the lower end in FIGS. 1 and 2) is connected to the opening 17 of the second case 14. The second case 14 is provided with another opening 57 to which the discharge pipe 62 is connected. Sealing materials are provided between the supply pipe 61 and the case through-hole 56 and the refrigerant pipe 24, between the discharge pipe 62 and the opening 57, and between the external connection pipe 4 and the opening 17, respectively. However, illustration is abbreviate | omitted.

  The refrigerant supplied from the outside of the inverter 2 through the refrigerant supply pipe 61 is supplied to the stacked cooling unit 20 through the case through hole 56 and one refrigerant pipe 24. The refrigerant flowing from the refrigerant pipe 24 reaches all the cooling plates 21 through one connection pipe 25 connected to the cooling plate 21. The refrigerant flows through the inside of the cooling plate 21 in the longitudinal direction, and cools the power card 22 in contact with the cooling plate 21. The refrigerant that has absorbed the heat of the power card 22 is discharged from the first case 12 through the other connection pipe 25 connected to the cooling plate 21 and through the refrigerant pipe 23 and the case through hole 16. Thereafter, the refrigerant is guided to the second case 14 (that is, the cooler 15) through the external connection pipe 4. Inside the second case 14, a refrigerant flow path 19 (see FIG. 3) is provided at a position corresponding to a position directly below the reactor 52 and the condenser 51 installed in the first case 12. While the refrigerant passes through the flow path 19, the heat of the reactor 52 and the condenser 51 is absorbed. The refrigerant is finally discharged through the refrigerant discharge pipe 62 connected to the opening 57. A cooling system including a radiator that cools the refrigerant and a pump that circulates the refrigerant is provided outside the inverter 2, and the refrigerant that has absorbed the heat of the electronic components in the inverter 2 is cooled by the radiator and is then returned to the inverter 2 again. Sent to.

  The refrigerant is a liquid, for example, water or LLC (Long Life Coolant). The cooler 15 and the stacked cooling unit 20 are liquid-cooled coolers.

  The laminated cooling unit 20 is further laminated with an insulating plate 55 and a leaf spring 54 at one end of the laminated body. The stacked cooling unit 20 is supported so as to be sandwiched between the inner wall of the first case 12 and the support column 53. The stacked cooling unit 20 is supported by the first case 12 by the leaf spring 54 while applying a load in the stacking direction. Due to the load of the leaf spring 54, the alternately stacked cooling plates 21 and the power card 22 are in close contact with each other, and heat is well transmitted between them.

  With reference to FIGS. 4, 5, and 6, the connection structure of the refrigerant pipe 23, the case through-hole 16 and the external connection pipe 4 and the sealing material 3 that seals between them will be described. FIG. 4 is an enlarged view of a range surrounded by a two-dot chain line IV in FIG. In other words, FIG. 4 is a cross-sectional view including the center line of the case through hole 16 and the opening 17. Further, FIG. 5 is an enlarged view in which a range surrounded by a two-dot chain line V in FIG. 4 is enlarged. 6 is a partial cross-sectional view of the range including the refrigerant pipe 23 and the seal material 3 taken along the line VI-VI in FIG. In FIG. 4, the power card is indicated by a virtual line.

  The refrigerant pipe 23 is a circular pipe and extends from the cooling plate 21 toward the outside of the first case 12. The refrigerant pipe 23 passes through the case through hole 16 and protrudes from the outer surface 12 a of the first case 12. This protruding portion is located inside an opening 44 of the external connection pipe 4 described later. In other words, the outer peripheral surface 23 a of the refrigerant pipe 23 is fitted to the external connection pipe 4 outside the first case 12. Further, the center line of the refrigerant pipe 23 coincides with the center line of the case through hole 16.

  The external connection pipe 4 is a U-shaped circular pipe. At both ends of the U-shape, flanges 41 and 42 for fixing the external connection pipe 4 to the cases 12 and 14 are provided. A sealing material 8 is provided on the surface (flange surface) of the flange 42 on the second case 14 side, and seals between the flange surface and the outer surface of the second case 14. Although not shown, the flange 42 is provided with a through hole, and one end of the external connection pipe 4 is fixed to the second case 14 through the through hole. On the other hand, the end surface (flange surface 41 a) of the flange 41 on the second case 12 side is in contact with the outer surface 12 a of the first case 12. On the flange 41 side, the opening 44 of the external connection pipe 4 is larger in diameter than the inner diameter of the circular pipe 43 in the middle of the U-shaped pipe. The diameter of the opening 44 of the external connection pipe 4 is the same as the inner diameter of the case through hole 16. Although not shown, the flange 41 is provided with a through hole, and the other end of the external connection pipe 4 is fixed to the first case 12 through the through hole.

  The sealing material 3 is a cylindrical member as well represented in FIG. The sealing material 3 is made of a highly flexible material such as rubber. As shown in FIG. 5, the sealing material 3 covers the outer peripheral surface 23 a of the refrigerant pipe 23. And the sealing material 3 is located between the outer peripheral surface 23a of the refrigerant pipe 23, and the inner peripheral surface 16a of the case through-hole 16, and seals between them. Furthermore, the sealing material 3 is also located between the outer peripheral surface 23a of the refrigerant pipe 23 and the inner peripheral surface 44a of the opening 44 in the external connection pipe 4, and seals between them. Further, a plurality of triangular convex portions 3 a are provided on the outer peripheral surface of the sealing material 3 along the center line of the sealing material 3 so as to go around the outer peripheral surface. As shown in the figure, the apex of the convex portion 3 a is deformed by being pressed against the inner peripheral surface 16 a of the case through hole 16. On the other hand, a plurality of triangular projections 3 b are provided on the inner peripheral surface of the sealing material 3 along the center line of the sealing material 3 so as to go around the inner peripheral surface. Similarly to the convex portion 3 a, the convex portion 3 b is deformed by being pressed against the outer peripheral surface 23 a of the refrigerant pipe 23. By providing the convex portion 3 a on the sealing material 3, the contact area between the sealing material 3 and the opening 44 and the inner peripheral surface of the case through-hole 16 can be reduced. By reducing the contact area, it is possible to reduce the frictional force acting when the sealing material 3 is inserted into the opening 44 and the case through hole 16. Similarly, by providing the convex portion 3b, it is possible to reduce the frictional force that acts when the refrigerant tube 23 is inserted into the sealing material 3.

  A ring-shaped cored bar 31 is embedded in the sealing material 3 at a position facing the inner peripheral surface 16 a of the case through-hole 16. As shown in FIG. 5, a part of the cored bar 31 is exposed from the end surface of the sealing material 3 located inside the first case 12. The end surface of the portion embedded in the sealing material 3 of the core metal 31 is located inside the case through-hole 16. The cored bar 31 is made of a material harder than the sealing material 3, for example, a metal. By embedding the cored bar 31, deformation of the main body portion of the sealing material 3 in which the cored bar 31 is embedded between the inner peripheral surface 16 a of the case through-hole 16 and the outer peripheral surface 23 a of the refrigerant pipe 23 is suppressed. Thereby, the adhesiveness with respect to the internal peripheral surface 16a and the outer peripheral surface 23a of convex part 3a, 3b can be improved.

  Further, the sealing material 3 is provided with a drain hole 32 penetrating between the inner peripheral surface and the outer peripheral surface of the sealing material 3 on the outer side of the first case 12 with respect to the core metal 31. The drainage hole 32 is located inside the case through hole 16, and is between the outer peripheral surface 23 a of the refrigerant pipe 23 and the inner peripheral surface of the sealing material 3, and between the inner peripheral surface 16 a of the case through hole 16 and the sealing material 3. It connects between the outer peripheral surfaces. Further, as shown in FIG. 6, the water drain hole 32 is located on the vertically lower side (the negative direction of the Z axis) in the mounting posture of the inverter 2.

  The effect of the drain hole 32 will be described. When the sealing performance of the sealing material 3 is lowered, the refrigerant may leak from the sealing material 3 particularly when the sealing performance on the side where the cored bar 31 is not embedded (side of the external connecting pipe 4) is lowered. By providing the drain hole 32, the refrigerant that has entered between the inner peripheral surface of the sealing material 3 and the outer peripheral surface 23 a of the refrigerant pipe 23 passes through the drain hole 32 as indicated by a thick arrow WF shown in FIG. 5. Thus, the sealing material 3 is pulled out between the outer peripheral surface of the sealing material 3 and the inner peripheral surface 16a of the case through-hole 16. The refrigerant that has escaped during this time travels between the flange surface 41 a and the outer surface 12 a of the first case 12 and escapes to the outside of the first case 12. On the other hand, since the metal core 31 is embedded in the sealing material 3 between the refrigerant pipe 23 and the case through-hole 16, the sealing performance is high. That is, the leaked refrigerant does not enter the inside of the first case 12 and flows out of the first case 12 as indicated by the thick arrow WF in FIG. Thereby, even if the sealing performance of the sealing material 3 is lowered, it is possible to prevent the electronic component housed in the first case 12 from being flooded.

  In the embodiment, “first case 12” is an example of “case”, and “stacked cooling unit 20” is an example of “cooler”. “Case through hole 16” is an example of “through hole”, and “external connection pipe 4” is an example of “external pipe”.

  Points to be noted regarding the embodiment will be described. In the embodiment, the coolant supply pipe 61, the case through hole 56, and the seal material for the coolant pipe 24 are not shown, but it is also preferable to employ a connection structure using the seal material 3 of the embodiment.

  Further, the drain hole 32 is located inside the case through-hole 16, but may be located inside the opening 44 of the external connection pipe 4. Similar to the embodiment, the leaked refrigerant passes through the drain hole 32 and escapes to the outside of the case.

  Further, in the embodiment, the sealing material 3 and the external connection pipe 4 are configured as separate bodies, but the sealing material 3 and the external connection pipe 4 may be configured as a single body. For example, there is a method of forming an external connecting pipe and a sealing material by two-color molding (double molding) using two kinds of materials. By integrating the outer connecting pipe and the sealing material, the inner peripheral surface of the outer connecting pipe and the outer peripheral surface of the sealing material are joined, and the sealing performance between them can be improved.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2: Inverter 3: Sealing material 4: External connecting pipe 12: First case 14: Second case 15: Cooler 16, 56: Case through hole 16a: Inner peripheral surface 17, 57: Opening 20: Laminate cooling unit 21 : Cooling plate 22: Power card 23, 24: Refrigerant tube 23 a: Outer peripheral surface 31: Core metal 32: Drain hole 41, 42: Flange 44: Opening 44 a: Inner peripheral surface 51: Smoothing capacitor 52: Reactor 54: Plate Spring 61: supply pipe 62: discharge pipe

Claims (1)

It is an in-vehicle electronic device that includes an electronic component inside and a liquid-cooled cooler that cools the electronic component.
A case having a through hole;
A refrigerant pipe extending from the cooler and extending to the outside of the case through the through hole;
An external pipe fitted to the outer periphery of the refrigerant pipe on the outside of the case;
Covers the outer peripheral surface of the refrigerant pipe, seals between the outer peripheral face of the refrigerant pipe and the inner peripheral face of the through hole, and between the outer peripheral face of the refrigerant pipe and the inner peripheral face of the external pipe A cylindrical sealing material that seals
With
A ring-shaped cored bar is embedded in the sealing material at a position facing the inner peripheral surface of the through hole, and penetrates the inner peripheral side and outer peripheral side of the sealing material outside the case from the cored bar. Water drain holes are provided,
In-vehicle electronic device characterized by the above.

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