JP4771224B2 - Grommet and fuel cell seal structure - Google Patents

Description

  The present invention relates to a grommet as a seal member and a seal structure for a fuel cell.

  In a conventional fuel cell system, there is a seal structure that seals between a fuel cell case that accommodates a fuel cell and a fuel cell pipe that is inserted into a through hole formed in the fuel cell case, using a grommet. It has been proposed (see, for example, Patent Document 1 below).

In the fuel cell system described above, after the fuel cell is accommodated in the fuel cell case, the pipe to which the grommet is attached is connected to the fuel cell through a through hole formed in the lower surface of the fuel cell case. The grommet is attached to the fuel cell case so as to abut on the periphery of the through hole from the outside of the fuel cell case.
JP 2005-147241 A

  In the fuel cell system described above, the grommet is attached so as to be fitted into the through hole from the outside of the fuel cell case, so that there is a problem that the assembling work is difficult to perform. Further, if the grommet is not fitted accurately, the sound generated in the fuel cell case may leak from between the grommet and the fuel cell case, and there is a problem that sufficient sound insulation cannot be obtained.

  The present invention has been made in view of the above circumstances, and provides a grommet that can be easily and accurately assembled to an object to be assembled, thereby obtaining sufficient sound insulation, and a fuel cell seal structure. It is intended to provide.

  In order to achieve the above object, a grommet according to the present invention is a grommet that seals a gap between an insertion member and a member to be inserted, and has an insertion hole through which the insertion member is inserted, and one end of the insertion hole. A fixing portion that is fixed to the insertion member is provided on the side, and a contact portion that is in contact with the insertion member in the insertion direction of the insertion member is provided on the other end side of the insertion hole.

  In this configuration, a diameter-enlarged portion that increases in diameter as it goes from the fixed portion toward the inserted member side, and the contact portion is provided on the opposite side of the expanded-diameter portion from the fixed portion. Good.

  According to the above configuration, the abutment portion of the grommet attached to the insertion member (for example, a tubular, linear, or rod-like member such as a pipe or a harness) via the fixing portion has the insertion member and the insertion member ( For example, it is brought into contact with the inserted member so as to cover a gap between the case wall and a plate-like member such as a panel. That is, by pressing the grommet against the inserted member around the gap, the gap between the inserted member and the inserted member can be sealed, so that the assembling work is easy to perform.

  In the grommet of the present invention, the expanded diameter portion may be harder than either the fixed portion or the contact portion.

  According to this configuration, the expanded portion corresponding to the portion excluding the fixed portion that contacts the flange of the pipe and the contact portion that contacts the inserted member is made harder than the other portions (the fixed portion and the contact portion). By virtue of being highly rigid, vibration of the enlarged diameter portion is suppressed, so that vibration is hardly transmitted to other places via the enlarged diameter portion. Therefore, the sound insulation of the grommet is enhanced.

  In the grommet of the present invention, the fixing portion may be configured to be detachable from a flange provided on the insertion member.

  According to this configuration, since the grommet is fixed to the flange having a larger diameter than the insertion member, the grommet is stabilized. Moreover, since the grommet can be attached to and detached from the flange, the grommet can be easily replaced.

  The fuel cell seal structure of the present invention is a fuel cell seal structure in which a grommet seals between a fuel cell case and a pipe connected to the fuel cell through a through hole formed in the fuel cell case. The grommet includes a fixed portion fixed to the pipe, a diameter-expanded portion that expands from the fixed portion toward the wall surface side of the fuel cell case, and the fixed portion of the diameter-expanded portion. An abutting portion provided on the opposite side, and the abutting portion is disposed so as to abut on the periphery of the through-hole opening in the wall surface from the inside of the fuel cell case.

According to this structure, the contact part of the grommet attached to piping via the fixing | fixed part is contact | abutted to a fuel cell case so that a through-hole may be covered with the said grommet. That is, since the gap between the fuel cell case and the pipe is sealed by pressing the grommet from the inside around the through-hole formed in the fuel cell case, the assembly work for housing the fuel cell in the fuel cell case is performed. easy.
Said structure WHEREIN: The said enlarged diameter part may be harder than any of the said fixing | fixed part and the said contact part.

  In the fuel cell seal structure of the present invention, the fixing portion is fixed to a flange of the pipe, and a female shape in which a male joint of a counterpart pipe connected to the pipe is inserted upward into the flange. A joint may be formed.

  In this configuration, by inserting the male joint of the mating pipe upward into the female joint formed on the flange of the fuel cell side pipe, the fuel cell side pipe and the mating side (hydrogen supply source side) The pipe is connected. That is, since the male joint is inserted upward, when separating the male and female joints, it is difficult for foreign matters such as mud and dust to enter the pipe.

  According to the present invention, the grommet can be easily and accurately assembled to the object to be assembled, and thereby sufficient sound insulation can be obtained.

  Next, a first embodiment of a grommet and a fuel cell seal structure according to the present invention will be described. Hereinafter, the case where the grommet and the fuel cell seal structure are applied to an in-vehicle power generation system of a fuel cell vehicle will be described. However, the present invention is not limited to such an application example, and ships, aircrafts, trains, walking robots, and the like. The present invention can be applied to any mobile body, for example, to a stationary power generation system in which a fuel cell is used as a power generation facility for a building (house, building, etc.).

  In the fuel cell system 1 shown in FIG. 1, air (outside air, humidified gas) as an oxidizing gas is supplied to an air supply port of the fuel cell 20 via an air supply path 71. The air supply path 71 is provided with an air filter A1 that removes particulates from the air, a compressor A3 that pressurizes the air, and a humidifier A21 that adds required moisture to the air. The air filter A1 is provided with an air flow meter (not shown) that detects the air flow rate. The compressor A3 is driven by the motor M.

  Air off-gas (oxidation off-gas, humidified gas) discharged from the fuel cell 20 is discharged to the outside through the exhaust path 72. The exhaust path 72 is provided with a pressure adjustment valve A4 and a humidifier A21. The pressure adjustment valve A4 functions as a pressure regulator that sets the supply air pressure to the fuel cell 20.

  Hydrogen gas as the fuel gas is supplied from the hydrogen supply source 30 to the hydrogen supply port of the fuel cell 20 through the hydrogen supply path 74. The hydrogen supply source 30 corresponds to, for example, a high-pressure hydrogen tank, but may be a so-called fuel reformer, a hydrogen storage alloy, or the like.

  The hydrogen supply path 74 includes a shutoff valve H100 that supplies or stops supplying hydrogen from the hydrogen supply source 30, a hydrogen pressure adjustment valve H9 that adjusts the supply pressure of hydrogen gas to the fuel cell 20 by reducing the pressure, and a hydrogen supply path 74. A pressure sensor P1 for measuring the pressure of the hydrogen gas inside and an injector 80 are provided. The injector 80 has a function as a flow rate adjusting valve and a function as a variable pressure control valve, and controls the stoichiometric ratio and the back pressure by both functions.

  The hydrogen gas that has not been consumed in the fuel cell 20 is discharged as hydrogen offgas (fuel gas offgas) to the hydrogen circulation path 75 and returned to the downstream side of the hydrogen pressure regulating valve H9 in the hydrogen supply path 74. The hydrogen circulation path 75 includes a gas-liquid separator H42 that recovers moisture from the hydrogen off-gas, a drain valve H41 that recovers the recovered product water in a tank (not shown) outside the hydrogen circulation path 75, and a hydrogen pump that pressurizes the hydrogen off-gas. H50 is provided.

  The shut-off valve H21 closes the anode side of the fuel cell 20. The operation of the hydrogen pump H50 is controlled by the control unit 50 and supplies hydrogen gas to the fuel cell 20 through the hydrogen supply path 74, or supplies hydrogen gas to the fuel cell 20 through the hydrogen supply path 74 and the hydrogen circulation path 75. Is possible. The hydrogen off-gas merges with the hydrogen gas in the hydrogen supply path 74 and is supplied to the fuel cell 20 for reuse.

  The hydrogen circulation path 75 is connected to the exhaust path 72 on the downstream side of the humidifier A21 by the purge flow path 76 via the discharge control valve H51. The discharge control valve H51 is an electromagnetic shut-off valve, and operates according to a command from the control unit 50, whereby the hydrogen off-gas is discharged (purged) together with the air off-gas discharged from the fuel cell 20. By performing this purge operation intermittently, it is possible to prevent a cell voltage from being lowered due to an increase in the impurity concentration in the hydrogen gas.

  A cooling path 73 for circulating the cooling water is provided at the cooling water inlet / outlet of the fuel cell 20. The cooling path 73 is provided with a radiator (heat exchanger) C2 that radiates heat of the cooling water to the outside, and a pump C1 that pressurizes and circulates the cooling water. The radiator C2 is provided with a cooling fan C13 that is rotationally driven by a motor.

  The fuel cell 20 is configured as a fuel cell stack in which a required number of single cells that receive supply of hydrogen gas and air and generate electric power through an electrochemical reaction are stacked. The electric power generated by the fuel cell 20 is supplied to a power control unit (not shown). The power control unit consists of an inverter that supplies electric power to the drive motor of the vehicle, an inverter that supplies electric power to various auxiliary devices such as a compressor motor and a motor for a hydrogen pump, and charging of power storage means such as a secondary battery. A DC-DC converter or the like that supplies power to the motors from the power storage means is provided.

  The control unit 50 is configured by a control computer system having a known configuration such as a CPU, ROM, RAM, HDD, input / output interface, display, and the like, and a required load such as an accelerator signal of a vehicle (not shown) and each part of the fuel cell system 1 Control information is received from these sensors (pressure sensor, temperature sensor, flow sensor, output ammeter, output voltmeter, etc.), and the operation of valves and motors in each part of the system is controlled.

  The injector 80 includes an injection hole for injecting gaseous fuel such as hydrogen gas, a nozzle body for supplying and guiding the gaseous fuel to the injection hole, and movable in an axial direction (gas flow direction) with respect to the nozzle body. And a valve body that is accommodated and held to open and close the injection hole. The valve body of the injector 80 is driven by, for example, a solenoid, and the opening area (opening state) of the injection hole is switched between two or more stages or continuously without turning on / off the pulsed excitation current supplied to the solenoid. be able to.

  The fuel cell 20 is accommodated in a fuel cell case C as shown in FIG. Of the hydrogen supply path 74, a part of the pipe 90 that forms the hydrogen supply path 74 upstream of the injector 80, that is, the hydrogen supply path 74 between the injector 80 and the hydrogen supply source 30 is interposed via a support member (not shown). The fuel cell case C is fixed to the end plate 20A and is inserted through a through hole C1.

  The pipe 90 is divided into a pipe 90 </ b> A on the injector 80 side and a pipe 90 </ b> B on the hydrogen supply source 30 side, and a pipe connector 91 is provided at both connection portions. A connector flange 91A constituting the pipe connector 91 is joined to the lower end of one pipe 90A by welding or the like, and a connector flange 91B constituting the pipe connector 91 is joined to the upper end of the other pipe 90B by welding or the like. Yes. The pipes 90A and 90B are connected by abutting the connector flange 91B on the connector flange 91A and fixing them together.

  The pipe 90A on the injector 80 side and the connector flange 91A of the pipe connector 91 are disposed inside the fuel cell case C. The connector flange 91A is provided with a grommet 100 that seals between the through hole C1 and the connector flange 91A.

  As shown in FIGS. 3 and 4, the grommet 100 includes a fixed portion 101 fixed to the connector flange 91 </ b> A of the pipe connector 91, and radially outward of the pipe 90 </ b> A from the fixed portion 101 (in other words, the fuel cell case C A diameter-enlarging portion 102 that expands in a circular arc shape so as to be spaced apart in the axial direction of the pipe 90A (in other words, the insertion direction of the pipe 90A with respect to the fuel cell case C) toward the outer side in the plane direction along the inner bottom surface; And an abutting portion 103 that is provided on the opposite side of the enlarged diameter portion 102 from the fixing portion 101 and abuts against the fuel cell case C around the through-hole C1 from the inside thereof.

  That is, the grommet 100 is a molded product of hard rubber, has an umbrella shape that expands in a substantially hemispherical shape, and is disposed so as to be faced to the wall surface (inner bottom surface) of the fuel cell case C. A substantially diamond-shaped insertion hole that forms the fixed portion 101 is opened at the top of the grommet 100.

  An endless groove is formed on the outer peripheral surface of the connector flange 91A. The fixing portion 101 of the grommet 100 is fitted into the groove, and the fixing portion 101 is fastened to the connector flange 91A by its own elasticity, so that the grommet 100 is detachably fixed to the connector flange 91A.

  A spring body 105 that supplements the elasticity of the grommet 100 is disposed inside the enlarged diameter portion 102 of the grommet 100. The spring body 105 gives the grommet 100 a pressing force that presses the grommet 100 itself against the inner wall surface of the fuel cell case C.

  As shown in FIG. 5, the contact portion 103 of the grommet 100 is easily deformed when the grommet 100 is pressed against the fuel cell case C, and is a variable type that increases the degree of sealing between the grommet 100 and the fuel cell case C. A portion 107 is provided. The deformable portion 107 includes a plurality of ridges 107 a formed concentrically along the annular contact portion 103.

  In the grommet 100 configured as described above, the fuel cell 20 is accommodated from above in the fuel cell case C whose upper surface is open. At this time, the grommet 100 is pressed against the bottom surface inside the fuel cell case C so as to cover the through hole C1. When the fuel cell 20 comes in contact with the bottom surface of the fuel cell case C, the grommet 100 seals between the through hole C1 and the connector flange 91A while maintaining its elastically deformed state.

  Further, since the fixing portion 101 of the grommet 100 is fastened to the connector flange 91A having a diameter larger than that of the pipe 90A, the grommet 100 is stabilized. Further, when the deformable portion 107 provided in the contact portion 103 is viewed locally, the plurality of protrusions 107a constituting the deformable portion 107 are elastically deformed and pressed against the bottom surface of the fuel cell case C, respectively. In other words, the fuel cell case C and the connector flange 91A are sealed in layers by the plurality of protrusions 107a.

  According to the seal structure that seals between the through hole C1 and the connector flange 91A using the grommet 100 configured as described above, the grommet 100 is pressed against the fuel cell case C around the through hole C1 from the inside. Since the gap between the fuel cell case C and the connector flange 91 </ b> A is sealed, the assembling work when housing the fuel cell 20 in the fuel cell case C is easy to perform. Further, since the gap between the fuel cell case C and the connector flange 91A is sealed by the plurality of protrusions 107a, the sealing performance and sound insulation performance are improved.

  When it is necessary to replace the grommet 100 for reasons such as aging deterioration, the fuel cell 20 and the pipe 90A are taken out from the fuel cell case C, and then the degraded grommet 100 is pulled to fix the grommet 100 fixing portion 101. Is extended from the groove of the connector flange 91A. Then, the new grommet 100 is mounted on the connector flange 91A in the same manner as the deteriorated grommet 100. Thus, since the grommet 100 can be attached to and detached from the connector flange 91A, the grommet 100 can be easily replaced.

  In the present embodiment, the spring body 105 that supplements the elasticity of the grommet 100 is disposed inside the enlarged diameter portion 102, but the pressing force against the fuel cell case C can be sufficiently covered by the elasticity of the grommet 100 itself. May not be provided with a spring body. In the present embodiment, the abutment portion 103 of the grommet 100 is provided with the deformable portion 107 that increases the sealing degree between the grommet 100 and the fuel cell case C. However, the material of the grommet 100 is appropriately selected. If sufficient flexibility is ensured in the contact portion 103 by selection, the deformable portion 107 may not be provided.

  Next, a second embodiment of the grommet and fuel cell seal structure according to the present invention will be described. In addition, the same code | symbol is attached | subjected to the component already demonstrated in the said 1st Embodiment, and those description is abbreviate | omitted.

  As shown in FIG. 6, the grommet 200 of the present embodiment includes a fixed portion 201 fixed to the connector flange 91 </ b> A of the pipe connector 91, and a radially outward portion of the pipe 90 </ b> A from the fixed portion 201 (in other words, the fuel cell case C The diameter-enlarged portion 202 that expands in a circular arc shape so as to be separated in the axial direction of the pipe 90A (in other words, the insertion direction of the pipe 90A with respect to the fuel cell case C) as it goes toward the outer side in the plane along the inner bottom surface of And an abutting portion 203 that is provided on the opposite side of the enlarged diameter portion 202 from the fixing portion 201 and abuts against the fuel cell case C around the through-hole C1 from the inside.

  The grommet 200 is a molded product of hard rubber and is common to the first embodiment in that the grommet 200 is disposed so as to face the wall surface (inner bottom surface) of the fuel cell case C. The configuration is different from that of the first embodiment in that it has a substantially umbrella shape in which a concavity recessed from the outer surface side to the inner surface side is formed between the portion 203 and the inner surface. At the top of the grommet 200, a substantially rhombic through-hole that forms the fixed portion 201 is opened. That is, the fixing part 201 and the contact part 203 are provided on one end side and the other end side of the through hole, respectively.

  The contact portion 203 of the grommet 200 is provided with a deformable portion 207 that increases the degree of sealing between the grommet 200 and the fuel cell case C, as in the first embodiment. The deformable portion 207 includes a plurality of protrusions 207 a formed concentrically along the circular contact portion 203.

  An annular member 210 made of a resin harder than the hard rubber forming the grommet 200 is attached to the inner side surface of the enlarged diameter portion 202. A substantially diamond-shaped through hole larger than the fixing portion 201 is formed at the center of the annular member 210, and the connector flange 91A is fitted into the through hole. That is, the fixing part 201 and the contact part 203 are provided on one end side and the other end side of the through hole, respectively. The annular member 210 is in close contact with the enlarged diameter portion 202 corresponding to the portion excluding the fixed portion 201 and the contact portion 203.

  An annular member 212 made of the same material as that of the annular member 210 is attached to the outer edge of the contact portion 203. On the lower edge of the annular member 212, a flange portion 213 is formed so as to be bent outward. The lower surface of the flange 213 contacts the fuel cell case C together with the plurality of protrusions 207a when the grommet 200 is pressed against the fuel cell case C around the through hole C1 from the inside.

  According to the seal structure that seals between the through hole C1 and the connector flange 91A using the grommet 200 configured as described above, the annular member 210 is attached to the inner surface of the enlarged diameter portion 202. The rigidity of the enlarged diameter portion 202 is increased. Thereby, since the vibration of the enlarged diameter part 202 is suppressed, it is difficult to transmit the vibration to other places via the enlarged diameter part 202. As a result, the sound insulation of the grommet 200 is also improved.

  Further, by attaching the annular member 212 to the outer edge of the contact portion 203, a portion that can be a vibration propagation path from the inside to the outside of the grommet 200 is blocked by the annular member 210 and the annular member 212 and meanders. Therefore, the sound insulation property of the grommet 200 is further improved.

  In this embodiment, a hard member different from the fixing portion 201, the enlarged diameter portion 202, and the contact portion 203 forming the main body of the grommet 200 is attached to the grommet 200. However, the hard member is attached. Instead of attaching, the grommet 200 itself may be cured to improve sound insulation.

  Next, a third embodiment of the grommet and fuel cell seal structure according to the present invention will be described. In addition, the same code | symbol is attached | subjected to the component already demonstrated in the said 1st Embodiment, and those description is abbreviate | omitted.

  In the present embodiment, the pipe connector 111 provided at the connection portion between the pipe 90A to which the grommet 100 is fixed and the pipe 90B on the hydrogen supply source 30 side is configured to fit the male and female joints. Specifically, as shown in FIG. 7, a connector flange 111A having a female joint 112 is joined to the pipe 90A by welding or the like, and a male joint to be inserted into the female joint 112 is joined to the pipe 90B. A connector flange 111B having 113 is joined by welding or the like. The male joint 113 is inserted upward with respect to the female joint 112.

  An endless groove is formed on the outer peripheral surface of the male joint 113, and a rubber O-ring 114 is fitted into the groove. The O-ring 114 is in pressure contact with the inner peripheral surface of the female joint 112 when the male joint 113 is inserted into the female joint 112.

  According to the seal structure that seals the gap between the through hole C1 and the connector flange 91A using the pipe connector 111 configured as described above, the male flange 112B of the connector flange 111B is connected to the female joint 112 of the connector flange 111A. Since the joint 113 is inserted upward, even if foreign matter such as mud and dust adheres to the pipe connector 111 when the male and female joints are separated for the replacement of the grommet 100, the foreign matter is male. It does not enter the inside of the pipe 90B beyond the joint 113.

1 is a schematic view showing a first embodiment of a fuel cell system according to the present invention. 1 is a diagram illustrating a first embodiment of a fuel cell system according to the present invention, and is a schematic diagram illustrating a fuel cell, piping fixed to the fuel cell, and a fuel cell case that houses the fuel cell. It is a figure which shows 1st Embodiment of the fuel cell system which concerns on this invention, Comprising: It is the top view which looked at the grommet attached to piping from upper direction. It is a figure which shows 1st Embodiment of the fuel cell system which concerns on this invention, Comprising: It is sectional drawing which shows the torn surface which follows the IV-IV line in the figure for the grommet of FIG. It is a figure which shows 1st Embodiment of the fuel cell system which concerns on this invention, Comprising: It is an expanded sectional view of the contact part provided in the grommet. It is a figure which shows 2nd Embodiment of the fuel cell system which concerns on this invention, Comprising: It is sectional drawing which fractured | ruptured a part of grommet. It is a figure which shows 3rd Embodiment of the fuel cell system which concerns on this invention, Comprising: It is sectional drawing which fractured | ruptured piping and the grommet attached to the piping.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 20 ... Fuel cell, 90A, 90B ... Piping (insertion member), 91A, 91B ... Connector flange, 100 ... Grommet, 101 ... Fixed part, 102 ... Expanded part, 103 ... Abutting part, 107a ... Projection, 200 ... Grommet, C ... Fuel cell case (inserted member)

Claims (6)

A grommet that seals a gap between the insertion member and the inserted member,
Having an insertion hole through which the insertion member is inserted;
A fixing portion fixed to the insertion member is provided on one end side of the insertion hole, and a contact portion that contacts the insertion member in the insertion direction of the insertion member on the other end side of the insertion hole ,
While having a diameter-enlarged portion that expands from the fixed portion toward the inserted member side, the contact portion is provided on the opposite side of the expanded portion from the fixed portion,
The expanded diameter portion is a grommet that is harder than both the fixed portion and the abutting portion . The grommet according to claim 1 ,
The grommet in which the fixed portion is configured to be detachable from a flange provided on the insertion member. The grommet according to claim 1 or 2,
A grommet in which a spring body for compensating the elasticity of the grommet is disposed inside the enlarged diameter portion . In the grommet according to any one of claims 1 to 3,
A grommet provided with a plurality of protrusions that are deformed when pressed against the contacted member . A fuel cell seal structure in which a grommet seals between a fuel cell case that houses a fuel cell and a pipe that is inserted into a through hole formed in the fuel cell case and connected to the fuel cell. There,
The grommet is provided on the opposite side of the fixed portion fixed to the pipe, the diameter-expanded portion that expands from the fixed portion toward the wall surface side of the fuel cell case, and the fixed portion of the diameter-expanded portion. A contact portion, and
The contact portion is disposed so as to contact from the inside of the fuel cell case around the through hole that opens to the wall surface ,
The expanded diameter portion is a fuel cell seal structure that is harder than either the fixed portion or the abutting portion . The fuel cell seal structure according to claim 5,
The fixing portion is fixed to a flange of the pipe,
A fuel cell seal structure in which a female joint into which a male joint of a counterpart pipe connected to the pipe is inserted upward is formed on the flange.

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