JP4127646B2 - Sensor mounting structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sensor mounting structure for mounting a sensor for measuring characteristics of a fluid to be measured flowing in a pipe to the pipe.
[0002]
[Prior art]
For example, in a polymer electrolyte fuel cell, an electrolyte membrane / electrode structure in which an anode side electrode and a cathode side electrode are respectively provided on both sides of an electrolyte membrane made of a polymer ion exchange membrane (cation exchange membrane) is separated by a separator. It is comprised by pinching.
[0003]
In this type of fuel cell, the fuel gas supplied to the anode side electrode, for example, a hydrogen-containing gas, moves to the cathode side electrode side through an electrolyte membrane that is appropriately humidified by hydrogen ionization on the electrode catalyst. To do. Electrons generated during the movement are taken out to an external circuit and used as direct current electric energy. Since the cathode side electrode is supplied with an oxidant gas, for example, an oxygen-containing gas such as air, the hydrogen ions, the electrons and the oxygen gas react to generate water at the cathode side electrode. .
[0004]
The fuel cell generally includes a fuel gas supply unit for supplying fuel gas into the fuel cell, an oxidant gas supply unit for supplying oxidant gas into the fuel cell, And a cooling medium supply unit for supplying a cooling medium (for example, circulating supply) to the fuel cell system.
[0005]
At that time, a temperature sensor, a pressure sensor, or a flow rate is provided for each pipe constituting the fuel gas supply unit, the oxidant gas supply unit, and the cooling medium supply unit in order to detect the operating state of the fuel cell and perform good control. Various sensors such as sensors are attached. As a structure for attaching such a sensor to a pipe, for example, a temperature sensor attaching structure of Patent Document 1 is known.
[0006]
As shown in FIG. 11, this attachment structure is a structure for attaching the gas sensor 1 to the metal pipe 2, and this gas sensor 1 has a sensor element 4 disposed in a housing 3. A double cover 5 is provided at the distal end of the housing 3, and a screw portion 6 is formed on the outer peripheral portion of the distal end of the housing 3. A nut 7 is fixed to the outer periphery of the pipe 2 by welding, and the screw portion 6 of the housing 3 is screwed to the nut 7.
[0007]
[Patent Document 1]
JP 2001-228112 A (paragraphs [0021] to [0025], FIG. 1)
[0008]
[Problems to be solved by the invention]
In Patent Document 1, a metal nut 7 is welded to a metal pipe 2, and a screw portion 6 of a housing 3 is screwed to the nut 7 to attach the gas sensor 1 to the pipe 2. However, rust is likely to occur in the threaded portion 6, and when the housing 3 is fastened to the nut 7, there is a possibility that ion elution may occur due to peeling of the surface treatment material, which deteriorates the fluid to be measured flowing through the pipe 2. It has been pointed out that the problem is
[0009]
Moreover, each piping which comprises a fuel cell system is comprised by resin piping in order to prevent the liquid junction by a cooling medium, produced water, etc. However, if the mounting structure of the above-mentioned Patent Document 1 is adopted for this resin pipe, the durability of the screw hole of the nut 7 is lowered because the nut 7 is made of resin, and the nut 7 is damaged or the sealing performance is lowered. There is a problem that is triggered. Moreover, when the screw portion 6 of the housing 3 is screwed into the nut 7, foreign matter such as rust may be mixed in the reaction gas or the cooling medium.
[0010]
The present invention solves this type of problem, and with a simple and compact configuration, the sensor can be securely attached to the pipe, and it effectively prevents foreign matter such as rust from entering the fluid to be measured. An object of the present invention is to provide a mounting structure for a sensor that can be used.
[0011]
[Means for Solving the Problems]
In the sensor mounting structure according to the first aspect of the present invention, a cylindrical portion is provided by bulging outward from the outer peripheral portion of the pipe, and the sensor is partially inserted into the cylindrical portion. A slit is formed in the cylindrical portion by cutting out in the circumferential direction, and a stopper is inserted from the slit in the normal direction of the cylindrical portion with the sensor partially inserted into the cylindrical portion. For this reason, the circular arc part of a fastener can be fitted into the circular groove part provided in the sensor, and this sensor can be reliably hold | maintained with respect to a cylindrical part.
[0012]
This eliminates the need for a screw structure at the sensor mounting part, simplifies the configuration, prevents foreign matter such as rust from being generated from the screw part, and effectively prevents the foreign matter from being mixed in the fluid to be measured. can do. Moreover, it is only necessary to insert the arc portion of the stopper metal into the circumferential groove portion of the sensor from the normal direction of the cylindrical portion, and the sensor can be reliably held by a simple operation.
[0013]
In addition, it is possible to rotate the sensor only by hooking the stopper fitting into the circumferential groove portion, thereby preventing the biasing force from acting on the sensor and adjusting the direction of the sensor. Furthermore, it is only necessary to hold a single circumferential groove portion with a stopper, and the influence of thermal stress can be avoided satisfactorily.
[0014]
In the sensor mounting structure according to claim 2 of the present invention, a ring member with a spring function having a substantially wave shape in a side view is interposed between the sensor and the end surface of the cylindrical portion. As a result, no gap is generated between the sensor and the cylindrical portion, and the sensor can be firmly and reliably held with respect to the cylindrical portion. For this reason, even if vibration etc. generate | occur | produce in piping, it becomes possible to prevent satisfactorily raising a sensor.
[0015]
Furthermore, in the sensor mounting structure according to claim 3 of the present invention, the pipe is an insulating resin pipe constituting at least a reaction gas circulation pipe or a cooling medium circulation pipe of the fuel cell. In a fuel cell, generated water and dew condensation water exist in the reaction gas circulation pipe and a liquid junction is likely to occur. On the other hand, a liquid junction due to the cooling medium tends to occur in the cooling medium circulation pipe.
[0016]
For this reason, particularly in a fuel cell, at least the reaction gas circulation pipe or the cooling medium circulation pipe is constituted by an insulating resin pipe, thereby ensuring insulation and preventing liquid junction and preventing ion elution from the pipe. be able to.
[0017]
Furthermore, in the sensor mounting structure according to claim 4 of the present invention, the characteristic of the fluid to be measured is, for example, the temperature, pressure, or flow rate when the fluid to be measured is a cooling medium, When the fluid to be measured is, for example, a gas (reactive gas or the like), the fluid is temperature, pressure, flow rate, concentration, humidity, or the like.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic configuration explanatory diagram of a fuel cell system 12 to which a sensor mounting structure 10 according to an embodiment of the present invention is applied.
[0019]
The fuel cell system 12 includes a fuel cell stack 16 in which a plurality of unit cells 14 are stacked. The fuel cell stack 16 includes a fuel gas supply unit 18 for supplying a fuel gas such as a hydrogen-containing gas, and an oxidant gas supply unit for supplying an oxidant gas such as an oxygen-containing gas (for example, air). 20 and a cooling medium supply unit 22 for supplying a cooling medium such as pure water, ethylene glycol, or oil are connected.
[0020]
The fuel cell stack 16 is provided with a fuel gas inlet 24a, an oxidant gas inlet 26a and a cooling medium inlet 28a at one end in the stacking direction (arrow X direction), and a fuel gas outlet 24b and an oxidant gas outlet at the other end in the stacking direction. 26b and a cooling medium outlet 28b are provided. Although not shown, the unit cell 14 includes, for example, an electrolyte membrane / electrode structure in which an anode side electrode and a cathode side electrode are opposed to each other on both sides of a polymer ion exchange membrane by a separator.
[0021]
In the fuel cell stack 16, the fuel gas supplied from the fuel gas inlet 24a is supplied to the anode side electrode of each unit cell 14, and then discharged from the fuel gas outlet 24b, while being supplied from the oxidant gas inlet 26a. The oxidized oxidant gas is supplied to the cathode side electrode of each unit cell 14 and then discharged from the oxidant gas outlet 26b. Further, the cooling medium supplied from the cooling medium inlet 28a is discharged from the cooling medium outlet 28b after each unit cell 14 is cooled.
[0022]
The fuel gas supply unit 18 includes a fuel gas supply pipe (reaction gas circulation pipe) 30a connected to the fuel gas inlet 24a and a fuel gas discharge pipe (reaction gas circulation pipe) 30b connected to the fuel gas outlet 24b. . For example, a temperature sensor 32 and a pressure sensor 33 are attached to the fuel gas supply pipe 30 a and the fuel gas discharge pipe 30 b via the attachment structure 10.
[0023]
The oxidant gas supply unit 20 includes an oxidant gas supply pipe (reaction gas circulation pipe) 34a connected to the oxidant gas inlet 26a and an oxidant gas discharge pipe (reaction gas circulation pipe) connected to the oxidant gas outlet 26b. ) 34b. Similarly, for example, a temperature sensor 36 and a pressure sensor 37 are attached to the oxidant gas supply pipe 34 a and the oxidant gas discharge pipe 34 b via the attachment structure 10.
[0024]
The cooling medium supply unit 22 includes a radiator 38 and a circulation pump 40, a cooling medium supply pipe (cooling medium circulation pipe) 42a connected to the cooling medium inlet 28a, and a cooling medium discharge connected to the cooling medium outlet 28b. A pipe (cooling medium flow pipe) 42b. A cooling line is constituted by the cooling medium supply pipe 42a and the cooling medium discharge pipe 42b, and the cooling medium supply pipe 42a and the cooling medium discharge pipe 42b are connected to the cooling medium supply pipe 42a and the cooling medium discharge pipe 42b through the mounting structure 10 in the same manner. A pressure sensor 45 is attached.
[0025]
The fuel gas supply pipe 30a, the fuel gas discharge pipe 30b, the oxidant gas supply pipe 34a, the oxidant gas discharge pipe 34b, the cooling medium supply pipe 42a, and the cooling medium discharge pipe 42b are made of insulating resin pipes such as polyvinylidene fluoride (PVDF). ) Or polypropylene (PP).
[0026]
As shown in FIGS. 2 and 3, the cooling medium supply pipe 42a is integrally formed with bulging cylindrical portions 50a and 50b protruding in the arrow B direction orthogonal to the flow direction of the cooling medium (arrow A direction). . A temperature sensor 44 and a pressure sensor 45 are attached to the bulging cylindrical portions 50a and 50b.
[0027]
As shown in FIG. 3, the temperature sensor 44 has a temperature sensitive element 52 such as a thermistor at the tip, and is sealed to the inner peripheral surface of the bulging cylindrical portion 50a via an O-ring 54. A clip mounting groove 56 is formed around the O-ring 54 so as to circulate.
[0028]
The pressure sensor 45 is fitted to the inner peripheral surface of the bulging cylindrical portion 50 b via the O-ring 54, and a clip mounting groove 58 is formed around the O-ring 54. A diaphragm 60 is housed inside the pressure sensor 45, and a strain sensor 62 is connected to the diaphragm 60.
[0029]
As shown in FIG. 4, slits 64 a and 64 b are formed in the bulging cylindrical portion 50 a by notching it in the circumferential direction at a position spaced apart from the distal end surface by a predetermined distance in the axial direction. The slits 64a and 64b correspond to the groove portion 56 of the temperature sensor 44 and are formed over a predetermined angular range with respect to the circumferential direction of the bulging cylindrical portion 50a.
[0030]
Similarly, slits 66a and 66b are formed in the bulging cylindrical portion 50b at positions spaced apart from the distal end surface by a predetermined distance in the axial direction. The slits 66a and 66b correspond to the groove portion 58 of the pressure sensor 45 and are formed over a predetermined angular range with respect to the circumferential direction of the bulging cylindrical portion 50b.
[0031]
A stopper, for example, a metal clip member 68 is inserted into the slits 64a and 64b. The clip member 68 is formed of, for example, SUS material, and integrally includes an arcuate portion 70 that fits into the groove portion 56 of the temperature sensor 44 and a curved portion 72 having a spring function. The end part is expanded outward.
[0032]
Similarly, a metal clip member 74 is inserted into the slits 66a and 66b of the bulging cylindrical portion 50b. The clip member 74 is integrally provided with an arc portion 76 that fits into the groove portion 58 of the pressure sensor 45 and a curved portion 78 having a spring function, and an open-side end portion is expanded outward.
[0033]
Ring members 80 and 82 are interposed between the temperature sensor 44 and the end surface of the bulging cylindrical portion 50a and between the pressure sensor 45 and the end surface of the bulging cylindrical portion 50b, respectively. The ring members 80 and 82 have a substantially wave shape in a side view and have a spring function in the thickness direction.
[0034]
A temperature sensor 44 and a pressure sensor 45 are attached to the cooling medium discharge pipe 42b via the mounting structure 10 in the same manner as the cooling medium supply pipe 42a. While the temperature sensor 32 and the pressure sensor 33 are attached to the fuel gas supply pipe 30a and the fuel gas discharge pipe 30b via the mounting structure 10, the oxidant gas supply pipe 34a and the oxidant gas discharge pipe 34b have Similarly, the temperature sensor 36 and the pressure sensor 37 are attached via the attachment structure 10 described above.
[0035]
The operation of the mounting structure 10 thus configured will be described below in the context of the fuel cell system 12 incorporating it.
[0036]
First, as shown in FIG. 1, the fuel gas supply unit 18 is driven, and the fuel gas is supplied from the fuel gas supply pipe 30a to the fuel gas inlet 24a. This fuel gas is supplied to the anode side electrode constituting each unit cell 14 of the fuel cell stack 16, and then discharged from the fuel gas outlet 24b to the fuel gas discharge pipe 30b.
[0037]
On the other hand, the oxidant gas supply unit 20 is driven, and oxidant gas, for example, air is supplied from the oxidant gas supply pipe 34a to the oxidant gas inlet 26a. This air is supplied to the cathode side electrode constituting each unit cell 14 of the fuel cell stack 16, and then discharged from the oxidant gas outlet 26b to the oxidant gas discharge pipe 34b.
[0038]
Thereby, in each unit cell 14, the fuel gas supplied to the anode side electrode and the air supplied to the cathode side electrode are consumed by the electrochemical reaction in the electrode catalyst, and power generation is performed. By this power generation, for example, electric power is supplied to a main motor (not shown), and the vehicle can travel.
[0039]
In the cooling medium supply unit 22, the circulation pump 40 is driven, and the cooling medium is supplied from the cooling medium supply pipe 42a to the cooling medium inlet 28a. After cooling each unit cell 14, this cooling medium is discharged from the cooling medium outlet 28b to the cooling medium discharge pipe 42b. The cooling medium, which is used for cooling each unit cell 14 and heated up, passes through the radiator 38 as necessary to exchange heat with the outside air, and is cooled to a predetermined temperature. Circulated.
[0040]
As described above, when the fuel cell system 12 is driven, the temperature sensor 32 measures the inlet temperature and the outlet temperature of the fuel gas that is the fluid to be measured, while the pressure sensor 33 measures the inlet of the fuel gas. Measure pressure and outlet pressure. The temperature sensor 36 measures the inlet temperature and the outlet temperature of the air to be measured, while the pressure sensor 37 measures the inlet pressure and the outlet pressure of the air. Furthermore, the temperature sensor 44 measures the inlet temperature and the outlet temperature of the cooling medium that is the fluid to be measured, while the pressure sensor 45 measures the inlet pressure and the outlet pressure of the cooling medium.
[0041]
In this case, in this embodiment, as shown in FIGS. 2 to 4, slits 64 a and 64 b are formed in the bulging cylindrical portion 50 a of the cooling medium supply pipe 42 a by cutting out in the circumferential direction. Then, in a state where the temperature sensor 44 is partially inserted into the bulging cylindrical portion 50a, the clip member 68 is inserted from the slits 64a and 64b in the normal direction of the bulging cylindrical portion 50a.
[0042]
For this reason, the arc portion 70 of the clip member 68 expands and contracts under the spring action of the curved portion 72 and fits into the groove portion 56 of the temperature sensor 44, and the temperature sensor 44 is securely held against the bulging cylindrical portion 50 a. can do. Therefore, in the attachment structure 10, since the temperature sensor 44 is attached to the bulging cylindrical portion 50a, the conventional screw structure is not required, and the structure is simplified and economical.
[0043]
In addition, the clip member 68 is only hooked on the groove 56 of the temperature sensor 44. As a result, the temperature sensor 44 can be rotated, it is possible to prevent a biasing force from acting on the temperature sensor, and to adjust the direction of the temperature sensor 44. Furthermore, only the single groove portion 56 is held by the clip member 68, and the influence of thermal stress can be favorably avoided.
[0044]
In addition, it is possible to effectively prevent foreign matter such as rust from being generated from the threaded portion, and to prevent the foreign matter from being mixed in the cooling medium as the fluid to be measured as much as possible. Furthermore, only by attaching / detaching the clip member 68 to / from the slits 64a, 64b, the temperature sensor 44 is attached and detached, and there is an advantage that workability is effectively improved.
[0045]
Furthermore, a ring member 80 with a spring function having a substantially wave shape in plan view is interposed between the temperature sensor 44 and the end surface of the bulging cylindrical portion 50a. Thereby, the gap between the clip member 68 and the slits 64 a and 64 b and the gap between the clip member 68 and the groove portion 58 can be absorbed by the deformation of the ring member 80.
[0046]
For this reason, there is no gap between the temperature sensor 44 and the bulging cylindrical portion 50a, and the temperature sensor 44 can be held firmly and reliably with respect to the bulging cylindrical portion 50a. Therefore, for example, even if vibration or the like occurs in the cooling medium supply pipe 42a, it is possible to effectively prevent the temperature sensor 44 from causing rattling.
[0047]
On the other hand, the pressure sensor 45 is similarly fixed to the bulging cylindrical portion 50b of the cooling medium supply pipe 42a via the clip member 74 constituting the mounting structure 10, and the same effect as the temperature sensor 44 described above is obtained. can get. Further, similar effects can be obtained with the temperature sensors 32 and 36 and the pressure sensors 33 and 37.
[0048]
By the way, in this embodiment, although the clip members 68 and 74 which have the circular arc parts 70 and 76 and the curved parts 72 and 78 are used, it is not limited to this. For example, as shown in FIG. 5, a substantially gate-shaped clip member 90 having a substantially rectangular shape and having an oval opening 90 a with one end opened may be used.
[0049]
Also, as shown in FIG. 6, a substantially C-shaped clip member 92, as shown in FIG. 7, a substantially R-shaped clip member 94, and as shown in FIG. Alternatively, a clip member 96 provided with a retaining portion 96a that is bent may be used.
[0050]
Further, a spring function may be provided on the stopper metal itself. For example, the clip member 98 having a substantially portal shape shown in FIG. 9 is provided with a bent portion 98a in part, and the clip member 100 shown in FIG. 10 is similarly provided with a bent portion 100a in part.
[0051]
In the present embodiment, the temperature sensor 32, 36 and 44 and the pressure sensor 33, 37 and 45 are attached to the fuel gas supply unit 18, the oxidant gas supply unit 20 and the cooling medium supply unit 22, respectively. However, the present invention is not limited to this. For example, the mounting structure 10 may be employed only for the temperature sensor 44 and the pressure sensor 45. In addition to the pressure sensor and the temperature sensor, a flow rate sensor may be used as the sensor, and in the fuel gas supply unit 18 and the oxidant gas supply unit 20, a sensor such as a concentration sensor or a humidity sensor may be used.
[0052]
【The invention's effect】
In the sensor mounting structure according to the present invention, since the sensor arranged in the cylindrical portion of the pipe is fixed via a stopper inserted from the normal direction of the cylindrical portion, the sensor is securely attached to the cylindrical portion. Can be held in.
[0053]
Accordingly, the screw structure of the sensor mounting portion is not required, the configuration is simplified, and foreign matter such as rust is effectively prevented from being generated from the screw portion, and the foreign matter is not mixed in the fluid to be measured. . Moreover, it is only necessary to insert the arc portion of the stopper metal into the circumferential groove portion of the sensor from the normal direction of the cylindrical portion, and the sensor can be reliably held by a simple operation.
[Brief description of the drawings]
FIG. 1 is a schematic configuration explanatory diagram of a fuel cell system to which a sensor mounting structure according to an embodiment of the present invention is applied.
FIG. 2 is a perspective explanatory view of a main part of the mounting structure.
FIG. 3 is a cross-sectional explanatory view of the mounting structure in FIG. 2;
FIG. 4 is an exploded perspective view of the mounting structure.
FIG. 5 is a perspective explanatory view of a substantially gate-shaped clip member.
FIG. 6 is a perspective explanatory view of a substantially C-shaped clip member.
FIG. 7 is a perspective explanatory view of a substantially R-shaped clip member.
FIG. 8 is a perspective explanatory view of a clip member with a retaining portion.
FIG. 9 is a perspective explanatory view of a substantially gate-shaped clip member with a spring.
FIG. 10 is a perspective explanatory view of a clip member with a spring.
FIG. 11 is an explanatory diagram of the schematic configuration of a fuel cell cooling device according to the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Mounting structure 12 ... Fuel cell system 14 ... Unit cell 16 ... Fuel cell stack 18 ... Fuel gas supply part 20 ... Oxidant gas supply part 22 ... Coolant supply part 24a ... Fuel gas inlet 24b ... Fuel gas outlet 26a ... Oxidation Agent gas inlet 26b ... Oxidant gas outlet 28a ... Cooling medium inlet 28b ... Cooling medium outlet 30a ... Fuel gas supply piping 30b ... Fuel gas discharge piping 32, 36, 44 ... Temperature sensors 33, 37, 45 ... Pressure sensors 34a ... Oxidation Agent gas supply pipe 34b ... Oxidant gas discharge pipe 38 ... Radiator 42a ... Cooling medium supply pipe 42b ... Cooling medium discharge pipe 50a, 50b ... Swelled cylindrical parts 64a, 64b, 66a, 66b ... Slits 68, 74, 90, 92 , 94, 96, 98, 100 ... clip members 80, 82 ... ring members

Claims (7)

A sensor mounting structure for mounting a sensor for measuring characteristics of a fluid to be measured flowing in a pipe to the pipe,
A cylindrical portion provided to bulge outward from the outer periphery of the pipe, and into which the sensor is partially inserted;
A slit formed by cutting the cylindrical portion in the circumferential direction;
With the sensor partially inserted into the cylindrical portion, a stopper that holds the sensor in the cylindrical portion by being inserted through the slit and fitted into a circumferential groove provided in the sensor;
Equipped with a,
The fasteners are attached structure sensor, wherein Rukoto to have a circular arc portion which fits into the circumferential groove.   2. The sensor mounting structure according to claim 1, further comprising a ring member with a spring function that is interposed between the sensor and an end surface of the cylindrical portion and has a substantially wave shape in a side view. Mounting structure.   3. The sensor mounting structure according to claim 1, wherein the pipe is an insulating resin pipe constituting at least a reaction gas circulation pipe or a cooling medium circulation pipe of the fuel cell.   The sensor mounting structure according to any one of claims 1 to 3, wherein the characteristics of the fluid to be measured include at least temperature, pressure, flow rate, humidity, or concentration. The sensor mounting structure according to any one of claims 1 to 4, wherein the first cylindrical portion into which the first sensor is partially inserted;
A second cylindrical portion into which the second sensor is partially inserted;
Have
The first cylindrical portion and the second cylindrical portion are integrally formed with the pipe,
The first slit formed in the first cylindrical portion and the second slit formed in the second cylindrical portion are axial directions of the first and second cylindrical portions from the pipe. On the other hand, the sensor mounting structure is characterized by being set at different distances. The sensor mounting structure according to any one of claims 1 to 5, wherein the stopper has an open-side end portion that expands outward,
An attachment structure for a sensor, wherein the open end protrudes to the outside of the cylindrical portion in a state where the stopper is attached to the slit. The sensor mounting structure according to any one of claims 1 to 6, wherein a part of the fastener is provided with a spring function portion having a substantially wave shape in a side view. .

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