JP6447480B2 - Sealing structure - Google Patents

Description

  The technology disclosed in this specification relates to a sealing structure between a through hole provided in a case and a pipe passing through the through hole.

  It is desirable to seal between the through hole and the pipe so that water does not enter the case from between the through hole provided in the case and the pipe passing through the through hole. For example, when a cooler for cooling electronic components is provided inside the case of the electronic device, it is necessary to pass a pipe for supplying / discharging the coolant to / from the cooler through a through hole provided in the case. For example, Patent Document 1 discloses a sealing structure that seals between a through hole of a case of an electronic device and a pipe.

  Patent Document 1 discloses a structure in which a through-hole provided in a case of an inverter and a pipe for discharging a refrigerant from a laminated cooling unit (corresponding to a cooler) inside the case are sealed by a connecting pipe. It is disclosed. The connecting pipe includes a cylindrical portion that is inserted into the through hole of the case, and a flange that is provided at one end of the cylindrical portion and that contacts the outer surface of the case. The pipe is inserted inside the cylinder portion. The O-ring seals the space between the cylindrical portion and the pipe and between the outer surface of the case and the flange. A groove for arranging an O-ring is provided on both the inner surface of the cylindrical portion and the flange.

JP 2014-102017 A

  In the structure of Patent Document 1, it is necessary to provide a groove for arranging the O-ring in the connecting pipe. The present specification provides a technique for sealing between a through hole and a pipe with a simple structure without providing a groove for arranging an O-ring.

  The sealing structure disclosed in the present specification is a sealing structure between a first through hole provided in a case and a pipe passing through the first through hole. The sealing structure is fixed to the case, the ring member through which the pipe passes is sandwiched between the ring member and the case, and a second through-hole through which the pipe passes is provided. A plate-like first seal member is provided. A step is provided on the inner periphery of the ring of the ring member. The step is provided such that the diameter of the ring inner periphery on the side closer to the case is larger than the diameter of the ring inner periphery on the side far from the case. A 2nd through-hole is smaller than the diameter of the ring inner periphery near the case. The second seal member is disposed in a space surrounded by the step, the first seal member, and the outer peripheral surface of the pipe.

  According to this configuration, the ring member and the case are sealed by the plate-like first seal member. The second seal member is disposed in a space surrounded by the step provided on the first seal member and the ring member and the outer peripheral surface of the pipe, and the space between the pipe and the ring member is sealed by the second seal member. The plate-like first seal member regulates one movement of the second seal member in the pipe axial direction instead of the groove. That is, with this configuration, the gap between the through hole and the pipe is sealed, and the ring member does not need to be provided with a groove for arranging the first seal member and the second seal member. Therefore, it is possible to seal between the through hole and the pipe with a simple structure. 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 an inverter provided with the sealing structure 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 broken line area IV in FIG. 3.

  An inverter 2 having the sealing structure of the embodiment will be described with reference to the drawings. The inverter 2 is mounted on an electric vehicle. The inverter 2 is a power converter that converts the DC power of the battery into AC power suitable for driving the traveling 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. In the drawing, an XYZ coordinate system is shown, and in the following description, the coordinate system is appropriately used. Note that the illustration of the cover 59 of the inverter 2 shown in FIG. 3 is omitted in FIGS.

  The inverter 2 includes a case 6, a cooler 7, a laminated unit 20 including a plurality of power cards 22 and a plurality of cooling plates 21, a capacitor 51, a reactor 52, and a circuit board (not shown). The power card includes a voltage converter circuit for realizing the function of the inverter 2, a switching element constituting the inverter circuit, and a resin mold for sealing the switching element. A transistor such as an IGBT is used as the switching element. The switching elements, capacitors 51, and reactors 52 of the plurality of power cards 22 constitute a voltage converter circuit that boosts the voltage of the battery and an inverter circuit that converts the boosted DC power into AC power.

  The circuit board generates a drive signal to be supplied to the switching element. Although the circuit board is disposed above the laminated unit 20, its illustration is omitted. Moreover, although the several power card 22, the capacitor | condenser 51, and the reactor 52 are mutually electrically connected by metal bus bars, the illustration is abbreviate | omitted.

  The case 6 houses the multilayer unit 20, the capacitor 51, and the reactor 52. The cooler 7 is fixed to the bottom surface of the case 6. The cooler 7 cools the reactor 52 and the condenser 51.

  The stacked unit 20 is a device for alternately stacking a plurality of power cards 22 and a plurality of cooling plates 21 to cool the plurality of power cards 22. The cooling plate is a flat plate type cooler through which the refrigerant passes. As shown in FIG. 1, each power card is sandwiched between two cooling plates. The switching element of each power card is cooled by these two cooling plates.

  Further, the stacked unit 20 is sandwiched between the inner wall of the case 6 and the support column 53. An insulating plate 55 and a leaf spring 54 are inserted between the cooling plate and the support column 53 located at one end in the stacking direction of the stacking unit 20 (the direction in which the plurality of cooling plates 21 are stacked, ie, the X-axis direction) Has been. The stacked unit 20 is supported by the case 6 by the leaf spring 54 while applying a load in the stacking direction. Due to the load of the leaf spring 54, the adhesion between the power card and the cooling plate is enhanced, and heat is efficiently transferred from the power card to the cooling plate.

  The plurality of cooling plates 21 are connected by two connecting pipes 23 and 24 extending in parallel to the stacking direction. Each connecting pipe is arranged at each of both ends in the longitudinal direction of the stacking unit 20 (both ends in the Y-axis direction in the drawing) when viewed from the stacking direction. The inside of each cooling plate is a cavity through which the refrigerant passes. The cavity inside each cooling plate communicates with the space inside the connecting pipes 23 and 24. As shown in FIG. 1, the connecting pipes 23 and 24 protrude from a cooling plate located at one end in the stacking direction. The projecting ends of the connecting pipes 23 and 24 are open, and the other end is closed. When the laminated unit 20 is housed in the case 6, the protruding ends of the connecting pipes 23 and 24 pass through the through holes 4 and 56 provided on the side surface of the case 6 and extend to the outside of the case 6.

  The space between the through hole 4 of the case 6 and the connecting pipe 23 is sealed by the sealing structure 10. The sealing structure 10 includes a ring member 12, an O-ring 13, and a metal gasket 14. Bolt fastening holes are provided in the ring member 12 and the metal gasket 14. The ring member 12 is fixed to the side surface of the case 6 with a bolt 17 penetrating the bolt fastening hole with the O-ring 13 and the metal gasket 14 sandwiched between the side surfaces of the case 6. Details of the sealing structure 10 will be described later. The through hole 56 and the connecting pipe 24 are also sealed with, for example, the same structure as the sealing structure 10, but the illustration is omitted in FIGS.

  The protruding end of the connecting pipe 24 is connected to the supply pipe 61. The projecting end of the connecting tube 23 is connected to one end of the U-shaped tube 3. The other end of the U-shaped tube 3 is connected to the opening 5 of the two openings 5 and 57 provided in the cooler 7. The opening 57 of the cooler 7 is connected to the discharge pipe 62. The two openings 5 and 57 communicate with a refrigerant flow path 9 (see FIG. 3) provided inside the cooler 7.

  The flow of the refrigerant will be described. The refrigerant is a liquid, for example, water or LLC (Long Life Coolant). That is, the stacked unit 20 and the cooler 7 are liquid-cooled coolers.

  The refrigerant is supplied from the outside of the inverter 2 to the connection pipe 24 through the supply pipe 61 and is distributed to the plurality of cooling plates 21 from the connection pipe 24. The refrigerant distributed to each cooling plate passes through the inside of each cooling plate in the longitudinal direction (Y-axis direction) and is collected in the connecting pipe 23. The refrigerant absorbs heat from the power card adjacent to each cooling plate while passing through the inside of each cooling plate. The refrigerant concentrated in the connecting pipe 23 flows to the opening 5 of the cooler 7 through the U-shaped pipe 3. The refrigerant flows from the opening 5 through the flow path 9 to the opening 57. The refrigerant flowing into the opening 57 is discharged out of the inverter 2 through the discharge pipe 62. The refrigerant absorbs heat from the condenser 51 and the reactor 52 while passing through the flow path 9.

  The sealing structure 10 will be described with reference to FIG. FIG. 4 is an enlarged view of a broken line area IV surrounding the sealing structure 10 of FIG. As described above, the ring member 12 is fixed to the case 6 by the bolt 17. The ring member 12 is disposed such that the inner ring periphery 15 is coaxial with the through hole 4 of the case 6, and the connecting pipe 23 passes through the ring inner periphery 15. The ring inner periphery 15 is provided with a step 16 following the side surface of the ring member 12 on the case 6 side. Specifically, the step 16 is provided so that the diameter R2 of the ring inner periphery 15b closer to the case 6 is larger than the diameter R1 of the ring inner periphery 15a far from the case 6. That is, a step is formed by the ring inner periphery 15b closer to the case 6, the ring inner periphery 15a far from the case 6, and the connection surface connecting the ring inner periphery 15a and the ring inner periphery 15b. As shown in FIG. 4, the diameter of the connecting pipe 23 is different between a portion located inside the ring member 12 and a portion located outside the ring member 12. The diameter of the part located outside is smaller than the diameter of the part located inside. The U-shaped tube 3 is fitted into a small-diameter portion located outside the ring member 12 of the connecting tube 23.

  The metal gasket 14 is a plate-like gasket made of metal. The metal gasket 14 is sandwiched between the ring member 12 and the case 6. As described above, the ring member 12 is fixed to the case 6 by the bolt 17, and the metal gasket 14 is in close contact with the case 6 and the ring member 12 by the fastening force of the bolt 17. The metal gasket 14 is provided with a through hole 14a through which the connecting pipe 23 passes. The diameter R3 of the through hole 14a is smaller than the diameter R2 of the ring inner periphery 15b on the side close to the case 6. The diameters of the ring inner periphery 15 and the through hole 14 a are smaller than the through hole 4 of the case 6.

  The O-ring 13 is a rubber gasket. The O-ring 13 is disposed in a space surrounded by the step 16 of the ring member 12, the metal gasket 14, and the outer peripheral surface of the connecting pipe 23. The O-ring 13 is in contact with at least the ring member 12 and the connecting pipe 23. The step 16 restricts the movement of the O-ring 13 in one direction in the axial direction (that is, the X-axis direction). The metal gasket 14 restricts the movement of the O-ring 13 in the other direction.

  The effect of the present embodiment will be described. According to the above configuration, the ring member 12 and the case 6 are sealed with the metal gasket 14. The metal gasket 14 constitutes a so-called face seal structure between the ring member 12 and the case 6. The space between the ring member 12 and the connecting pipe 23 is sealed with an O-ring. The O-ring forms a so-called shaft seal structure between the ring member 12 and the connecting pipe 23. That is, the gap between the through hole 4 of the case 6 and the connecting pipe 23 is sealed by the metal gasket 14 and the O-ring 13. Here, the O-ring 13 is disposed in a space surrounded by the step 16, the metal gasket 14, and the outer peripheral surface of the connecting pipe 23. Thereby, it is not necessary to provide a groove for arranging the O-ring 13 in the ring member 12 and the connecting pipe 23. Therefore, it is possible to seal between the through hole 4 and the connecting pipe 23 with a simple structure.

  Moreover, the metal gasket 14 implement | achieves the function which controls the movement of the axial direction of the O-ring 13 with the function which comprises a surface seal structure. This contributes to downsizing of the sealing structure 10.

  For example, when the inverter 2 is disposed in the front compartment of the electric vehicle, the inverter 2 is easily affected by the environment in which the electric vehicle travels. The influence from the environment is, for example, salt damage. Due to this salt damage, the case 6 of the inverter 2, particularly the portion that contacts the gasket of the case 6 can be corroded. The inventor has found that the progress of corrosion can be suppressed as the surface pressure applied to the gasket increases while observing the phenomenon of corrosion. In this embodiment, by adopting the metal gasket 14, it is possible to seal between the ring member 12 and the case 6 with a higher surface pressure than when an O-ring is employed. That is, the metal gasket 14 can suppress corrosion of the case 6 due to salt damage.

  Hereinafter, points to be noted regarding the technology shown in the embodiments will be described. The sealing structure 10 can be employed in any structure that seals between a through hole of a case and a pipe passing through the through hole. That is, each of the through hole 4 and the connecting pipe 23 is an example of a “first through hole” and a “pipe”.

  Instead of the metal gasket 14, for example, a plate-like rubber gasket may be employed. That is, each of the metal gasket 14 and the through hole 14a is an example of a “first seal member” and a “second through hole”.

  Instead of the O-ring 13, for example, an annular gasket whose cross section has a shape other than a circle may be employed. That is, the O-ring 13 is an example of a “second seal member”.

  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: U-shaped tube 4: Through hole 6: Case 7: Cooler 10: Sealing structure 12: Ring member 13: O ring 14: Metal gasket 14a: Through hole 15 (15a, 15b): Ring inner circumference 16: Step 17: Bolt 20: Laminating unit 21: Cooling plate 22: Power card 23, 24: Connection pipe 51: Capacitor 52: Reactor 53: Post 54: Leaf spring 59: Cover 61: Supply pipe 62: Discharge pipe

Claims (1)

A sealing structure between a first through hole provided in the case and a pipe passing through the first through hole;
A ring member that is fixed to the case and through which the pipe passes;
A plate-like first seal member sandwiched between the ring member and the case and provided with a second through hole through which the pipe passes;
With
A step is provided on the ring inner periphery of the ring member so that the diameter of the ring inner periphery near the case is larger than the diameter of the ring inner periphery far from the case,
The second through hole is smaller than the diameter of the ring inner periphery on the side close to the case,
A second seal member is disposed in a space surrounded by the step, the first seal member, and the outer peripheral surface of the pipe;
A sealing structure characterized by that.

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