JP2007132322A - Vaporized fuel treating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an vaporized fuel treating device capable of treating an vaporized fuel produced in a fuel tank, formed in a simple structure, and manufacturable easily. <P>SOLUTION: This vaporized fuel treating device comprises flow passage members 110, 233 having, therein, flow passages 160, 235 in which a gas containing the vaporized fuel produced in the fuel tank flow, a pump 200 having a suction port 210 communicating with the flow passages 160, 235, a vibration member 232 disposed in the flow passage 235 and vibrating according to the flow of the gas sucked by the pump 200, and a vibration detection means 400 disposed on the outside of the flow passage members 110, 233 and detecting the vibration of the vibration member 232 and outputting the detected signals. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an apparatus for treating evaporated fuel generated in a fuel tank.

  2. Description of the Related Art Conventionally, an evaporative fuel processing apparatus that processes evaporative fuel generated in a fuel tank by purging the internal combustion engine is known. As this type of fuel vapor processing system, for example, in order to check for fuel vapor leakage from the fuel tank, the reference pressure is detected while reducing or pressurizing the reference orifice with a pump, and then the fuel tank is decompressed or pressurized to detect. An apparatus for comparing the tank internal pressure with a reference pressure has been proposed (see, for example, Patent Document 1).

JP 2004-232521 A

However, for example, in the evaporative fuel processing apparatus disclosed in Patent Document 1, a pressure sensor is installed in a flow path through which gas sucked or discharged by a pump flows to detect a reference pressure and a tank internal pressure. Therefore, a seal is required to lead out the output signal line of the pressure sensor from the inside of the flow path member forming the flow path where the pressure sensor is installed. Further, since the pressure sensor touches the evaporated fuel, the pressure sensor must be subjected to a deterioration prevention process for the evaporated fuel, such as a surface seal. Accordingly, there is a problem that the configuration of the apparatus and the manufacturing process are complicated, resulting in an increase in cost.
The present invention has been made in view of the above problems, and an object of the present invention is to provide an evaporative fuel processing apparatus that has a simple configuration and is easy to manufacture.

  According to the first aspect of the present invention, the gas containing the evaporated fuel generated in the fuel tank flows through the flow path (hereinafter simply referred to as “flow path”) formed by the flow path member, The arranged vibration member vibrates according to the flow of gas sucked or discharged by the pump. Therefore, by detecting the vibration of the vibration member, it is possible to indirectly know the physical quantity correlated with the gas flow in the flow path, for example, the amount of evaporated fuel leakage from the fuel tank and the evaporated fuel concentration in the flow path. Moreover, the vibration of the vibration member can be detected by vibration detection means installed outside the flow path member by transmitting the vibration to the flow path member. Therefore, since it is not necessary to lead out the signal line for outputting the detection signal of the vibration detecting means from the inside of the flow path member to the outside, sealing is unnecessary. Further, since the vibration detecting means is not exposed to the gas containing the evaporated fuel, it is not necessary to perform the deterioration detecting process for the evaporated fuel on the vibration detecting means. As described above, according to the first aspect of the present invention, the configuration of the apparatus is simplified and the manufacture is facilitated.

According to the invention described in claim 2, since the vibration detecting means detects the vibration of the vibration member during the steady operation of the pump, vibration detection in a state where the gas flow in the flow path is stable is realized. Therefore, vibration can be detected with high accuracy.
According to the third aspect of the present invention, since the vibration detecting means is installed on the outer peripheral wall of the enclosing portion surrounding the outer peripheral side of the vibration member, the vibration of the vibration member is easily transmitted. Therefore, since a larger vibration can be detected, the detection accuracy is improved.

  According to the fourth aspect of the present invention, since the vibration member is installed in the vicinity of the suction port or the discharge port of the pump communicating with the flow path, the vibration of the vibration member causes the flow of the gas sucked or discharged by the pump. Reflecting enough, it can be relatively large. Therefore, based on the detection result of vibration, the physical quantity correlated with the gas flow in the flow path can be accurately known.

  According to the fifth aspect of the present invention, the vibrating member is a valve member that vibrates due to a gas flow by opening the flow path during operation of the pump. Thereby, the function which opens a flow path at the time of a driving | operation of a pump, and the function which vibrates according to a gas flow are realizable by the same valve member. Such aggregation of functions into one member can reduce the cost.

  According to the invention described in claim 6, the vibration detecting means detects vibration generated when the pump communicates with the orifice passage where the reference orifice is installed as a reference characteristic, and pumps the vibration into the tank passage communicating with the fuel tank. The vibration generated when is communicated is detected as a comparison characteristic. Since the reference characteristic and the comparative characteristic detected in this manner reflect the gas flow in the orifice flow path and the tank flow path as the flow path, the fuel vapor leakage from the fuel tank is prevented based on the comparison result of these characteristics. Can be determined.

The amplitude of vibration of the vibration member is a physical quantity that clearly reflects the gas flow in the flow path. Therefore, according to the seventh aspect of the invention, the vibration detecting means detects the vibration amplitude of the vibration member.
When the gas flow rate in the flow path is small, the vibration amplitude of the vibration member becomes small, and it may be difficult to detect the vibration amplitude. Therefore, according to the eighth aspect of the invention, since the vibration detecting means detects the amplitude and frequency of the vibration of the vibration member, the vibration of the vibration member is comprehensively determined from these two types of physical quantities, and the gas flow in the flow path. Can be captured.

  When the vibration of the vibration member is transmitted to the flow path member and the flow path member is distorted, the amount of distortion changes following the vibration of the vibration member. Therefore, according to the ninth aspect of the invention, the strain sensor as the vibration detecting means detects the strain generated in the flow path member by transmitting the vibration of the vibration member to the flow path member. Can be detected indirectly.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 2 shows an evaporated fuel processing system (hereinafter referred to as “processing system”) 10 according to an embodiment of the present invention. The evaporated fuel processing system 10 processes the evaporated fuel generated in the fuel tank 20 and supplies it to an internal combustion engine (not shown). The evaporated fuel processing system 10 includes an evaporated fuel processing device 100 (hereinafter referred to as “processing device”), a fuel tank 20, a canister 30, an intake device 40, an electronic control unit (hereinafter referred to as “ECU”) 50, and the like. ing.

  The fuel tank 20 communicates with the canister 30 through the canister channel 32. The canister 30 has an adsorbent 31 made of, for example, activated carbon, silica gel or the like, and adsorbs the evaporated fuel generated in the fuel tank 20 to the adsorbent 31 in a detachable manner. Therefore, the fuel vapor concentration in the fluid flowing out from the canister 30 toward the processing apparatus 100 becomes a predetermined value or less. The intake device 40 has an intake passage 41 that supplies intake air to the internal combustion engine. The intake passage 41 is provided with a throttle valve 42 for adjusting the intake flow rate, and the canister 30 communicates with the purge passage 33. The purge flow path 33 is provided with a purge valve 34 for opening and closing the purge flow path 33, and the evaporated fuel desorbed from the adsorbent 31 of the canister 30 is supplied to the intake flow path 41 according to the opening degree of the purge valve 34. It is supposed to be purged.

  The ECU 50 is composed of an electric circuit such as a microcomputer, for example, and the terminals of the connector 180 shown in FIG. 3 are connected to electric elements of the processing device 100, such as the coil 332 of the switching valve 300, the control circuit 280 of the motor unit 220, the strain sensor 400, and the like. 181 is electrically connected. Thereby, the ECU 50 electronically controls the operation of the processing apparatus 100. The ECU 50 according to the present embodiment has a function of controlling a vehicle-mounted device such as an internal combustion engine, for example, but may not have such a function.

As shown in FIG. 3, the processing apparatus 100 includes a housing 110, a reference orifice 522, a switching valve 300, a pump 200, a check valve 230, and a strain sensor 400.
The housing 110 is made of, for example, a plurality of members made of resin, and forms a tank flow path 140, an atmospheric flow path 150, a pump flow path 160, a discharge flow path 170, and an orifice flow path 510. In addition, the processing apparatus 100 of this embodiment has a module structure in which the components in the broken line shown in FIG. 2 are integrated.

  The tank channel 140 communicates with the fuel tank 20 through the canister 30 by connecting one end 141 to the canister 30. The other end 142 of the tank channel 140 is connected to the switching valve 300. One end 156 side of the atmospheric flow path 150 is open to the atmosphere, and the other end 157 of the atmospheric flow path 150 is connected to the switching valve 300. One end 161 of the pump flow path 160 is connected to the check valve 230, and the other end 162 is connected to the switching valve 300. The discharge flow path 170 communicates with the pump 200 and the atmospheric flow path 150.

  As shown in FIG. 3, the orifice channel 510 is formed coaxially on the inner peripheral side of the tank channel 140. One end 516 of the orifice channel 510 is opened and communicated with the tank channel 140, and the other end 517 of the orifice channel 510 is connected to and communicated with a midway part of the pump channel 160. A reference orifice 522 is installed in the middle of the orifice channel 510. The reference orifice 522 narrows the flow passage area of the orifice flow passage 510 and is formed in a cylindrical hole shape coaxial with the orifice flow passage 510. The diameter of the reference orifice 522 corresponds to the opening diameter at which evaporative fuel leakage is allowed in the fuel tank 20. For example, in the CARB and EPA standards, detection of air leakage from an opening corresponding to φ0.5 mm is required as detection accuracy of evaporated fuel leakage from the fuel tank 20. Therefore, in this embodiment, a diameter of φ0.5 mm or less is adopted as the diameter of the reference orifice 522.

The housing 110 is formed with a switching valve housing portion 130 that houses the switching valve 300. The switching valve 300 selects the pump flow path 160 or the atmospheric flow path 150 by the switching operation and communicates with the tank flow path 140. Specifically, the switching valve 300 includes a valve body 310, a shaft body 320, a first valve portion 350, an elastic member 360, a second valve portion 370, and an electromagnetic drive portion 330.
The valve body 310 is formed in a hollow shape and is held in the switching valve housing portion 130. The shaft body 320 is disposed coaxially with the end portion 162 of the pump flow path 160 inside the valve body 310 and can reciprocate in the axial direction.

  The first valve portion 350 is configured by combining a first valve seat 351 and a first valve body 352. The first valve seat 351 is formed on the flow path wall 163 surrounding the end 162 of the pump flow path 160 in the housing 110. The first valve body 352 is formed in a bottomed cylindrical shape, and is disposed so as to be separable from the first valve seat 351. An end 322 of the shaft body 320 on the first valve seat 351 side is inserted on the inner peripheral side of the first valve body 352. The elastic member 360 is a compression coil spring and is interposed between the flow path wall 163 and the first valve body 352. The elastic member 360 presses the bottom wall of the first valve body 352 against the end 322 of the shaft body 320 by a restoring force. Thereby, the first valve body 352 can reciprocate together with the shaft body 320.

  The second valve portion 370 is configured by combining a second valve seat 371 and a second valve body 372. The second valve seat 371 is formed in a portion surrounding the end 157 of the atmospheric flow path 150 in the valve body 310. The second valve body 372 is formed in an annular plate shape, and is disposed so as to be separable from the second valve seat 371. The inner peripheral side of the second valve body 372 is attached to the intermediate portion of the shaft body 320. As a result, the second valve body 372 can reciprocate together with the shaft body 320.

  The electromagnetic drive unit 330 includes a fixed core 333, a movable core 334, an elastic member 335, a coil 332, and the like. The fixed core 333 and the movable core 334 are made of a magnetic material and face each other in the axial direction of the shaft body 320. The fixed core 333 is fixed in position inside the valve body 310. The movable core 334 is attached to the end 321 of the shaft body 320 opposite to the first valve seat 351 and can reciprocate together with the shaft body 320. The elastic member 335 is a compression coil spring, and is interposed between the fixed core 333 and the movable core 334. The elastic member 335 presses the movable core 334 and the shaft body 320 toward the first valve seat 351 by a restoring force. The coil 332 is wound around the outer periphery of the fixed core 333. Energization of the coil 332 is intermittently performed according to the control of the ECU 50.

  When the coil 332 is not energized, no magnetic attractive force is generated between the fixed core 333 and the movable core 334, so that the shaft body 320 is moved to the first valve seat 351 side by the restoring force of the elastic member 335 (FIG. 3). To the bottom). At this time, since the first valve body 352 is seated on the first valve seat 31, the communication between the tank flow path 140 and the pump flow path 160 between the first valve body 352 and the first valve seat 351 is blocked. . At this time, since the second valve body 372 is separated from the second valve seat 371, the tank flow path 140 and the atmospheric flow path 150 communicate with each other. On the other hand, when the coil 332 is energized, a magnetic attractive force is generated between the fixed core 333 and the movable core 334, so that the shaft body 320 resists the restoring force of the elastic member 335 and the first valve seat. It moves to the side opposite to 351 (upper side in FIG. 3). At this time, since the first valve body 352 is separated from the first valve seat 351, the tank flow path 140 and the orifice flow path 510 communicate between the first valve body 352 and the first valve seat 351. At this time, since the second valve body 372 is seated on the second valve seat 371, the communication between the tank flow path 140 and the atmospheric flow path 150 is blocked. Note that the tank flow path 140 and the pump flow path 160 are always in communication with each other in the path passing through the reference orifice 522 of the orifice flow path 510.

  The housing 110 is further formed with a pump housing portion 120 that houses the vane pump 200. The pump unit 202 of the vane pump 200 includes a casing 203 and a rotor 204. A suction port 210 and a discharge port 211 are formed in the casing 203. A pump chamber 207 communicating with the suction port 210 and the discharge port 211 is formed inside the casing 203, and the rotor 204 is accommodated in the pump chamber 207. The rotor 204 is arranged eccentrically with respect to the pump chamber 207 and can rotate around the eccentric center line. The rotor 204 supports a plurality of vanes 209 that slide on the inner peripheral wall of the casing 203 by centrifugal force generated by the rotational drive. With the above configuration, the vane pump 200 sucks gas from the suction port 210 to each vane 209 and discharges it from the discharge port 211 when the rotor 204 is driven to rotate.

  The motor unit 220 of the vane pump 200 includes, for example, a brushless DC motor, and includes a rotating shaft 224, a control circuit 280, and a coil (not shown). The rotating shaft 224 passes through the casing 203 and is connected and fixed to the rotor 204 in the pump chamber 207. The control circuit 280 energizes the coil in accordance with the control of the ECU 50 and rotationally drives the rotating shaft 224 together with the rotor 204 by a magnetic field generated as a result. In the present embodiment, the control circuit 280 controls the rotational speeds of the motor shaft 224 and the rotor 204 to be constant, so that the vane pump 200 is steadily operated and the suction pressure of the vane pump 200 becomes substantially constant.

  As shown in FIG. 1, the check valve 230 includes a valve body 233, a valve member 232, and an elastic member 231. The valve body 233 includes a cylindrical portion 233a and a valve seat portion 233b. The cylindrical portion 233a is formed in a cylindrical shape with resin, for example, and is fitted and fixed to the housing 110 and the casing 203. The cylindrical portion 233a has a valve channel 235 formed therein, and both ends of the valve channel 235 communicate with the suction port 210 and the pump channel 160, respectively. The valve seat part 233b is formed in the shape of an annular plate with resin, for example, and is arranged in the middle part of the valve flow path 235. The valve member 232 is formed, for example, in a spherical shape with resin, and is accommodated in the cylindrical portion 233a on the inlet 210 side of the valve seat portion 233b. As a result, the valve member 232 is disposed in the valve flow path 235 so as to be surrounded on the outer peripheral side by the cylindrical portion 233a, can vibrate substantially in the flow path direction of the valve flow path 235, and is attached to and detached from the valve seat portion 233b. Is possible. The elastic member 231 is a compression coil spring, and is interposed between the cylindrical portion 233a and the valve member 232. The elastic member 231 presses the valve member 232 toward the valve seat portion 233b (the lower side in FIG. 1) by a restoring force. In the present embodiment, a mesh-like filter 234 is disposed between both ends of the valve channel 235 and the suction port 210 and the pump channel 160.

  When the vane pump 200 is stopped, the valve member 232 is displaced toward the pump flow path 160 by the restoring force of the elastic member 231 and is seated on the valve seat portion 233b, and the valve flow path 235 is closed. Therefore, when the vane pump 200 is stopped, the suction port 210 and the pump flow path 160 are blocked. On the other hand, when the vane pump 200 is operated, a pressure difference is generated on both sides of the valve member 232 due to the suction pressure received by the valve flow path 235 from the suction port 210, and the force due to the pressure difference overcomes the restoring force of the elastic member 231. The member 232 is displaced toward the suction port 210 and is separated from the valve seat 233b, and the valve flow path 235 is opened. Therefore, in this case, the suction port 210 and the pump flow path 160 communicate with each other through the valve flow path 235.

  Here, the generation principle of the vibration of the valve member 232 by the gas flow will be described. As described above, when the vane pump 200 is operated, the valve member 232 is separated from the valve seat portion 233b and the valve passage 235 is opened, so that the valve passage 235 is gas from the pump passage 160 side to the suction port 210 side. However, the force acting on the valve member 232 varies at this time. This is caused by a difference in pressure acting on the surface of the valve member 232 due to radial displacement of the valve member 232, processing tolerance with respect to the circular cross sections of the valve member 232 and the valve body 233, fluctuations in the suction pressure of the vane pump 200, and the like. Because. Therefore, since the balance position of the valve member 232 changes due to such a change in the acting force, the valve member 232 vibrates.

  The valve body 233 that is a rigid body in this embodiment does not change the cross-sectional area of the valve flow path 235. Therefore, the vibration of the valve member 232 generated by the above-described principle correlates with the gas flow in the valve flow path 235, specifically the gas flow rate. Further, the vibration of the valve member 232 is transmitted to the cylindrical portion 233a through the elastic member 231 and the valve seat portion 233b, and causes distortion in the cylindrical portion 233a. Therefore, in this embodiment, the strain sensor 400 is installed on the outer peripheral wall of the cylindrical portion 233a as vibration detection means, and is as close as possible to the suction port 210 and the valve member 232. The strain sensor 400 detects a variation in the amount of distortion of the cylindrical portion 233a following the vibration of the valve member 232, and outputs a detection signal to the ECU 50 side through the signal line 236. That is, the strain sensor 400 indirectly detects the vibration of the valve member 232, and hereinafter, the distortion amount fluctuation represented by the detection signal of the strain sensor 400 will be described as the vibration of the valve member 232.

  Although the detection signal of the strain sensor 400 represents the vibration of the valve member 232 as a voltage value as shown in FIG. 4, the vibration of the valve member 232 may be represented as a current value, for example. Further, as the strain sensor 400, for example, a sensor that is used for an acceleration (G) sensor of a vehicle, specifically, a piezoelectric type or strain gauge that detects the acceleration, speed, or displacement of the cylinder part 233a by contacting the cylinder part 233a. For example, an electromagnetic, electrostatic, or optical sensor that detects displacement of the cylindrical portion 233a without contacting the cylindrical portion 233a may be used.

  As described above, in the present embodiment, the housing 110 and the valve body 233 correspond to the “flow path member” described in the claims, and the flow paths 140, 160, 170, 510, and 235 are described in the claims. Corresponds to “flow path”. In this embodiment, the valve body 233 corresponds to an “enclosure” described in the claims. Furthermore, in this embodiment, the valve member 232 corresponds to the “vibration member” recited in the claims, and the strain sensor 400 corresponds to the “vibration detection means” recited in the claims.

  Next, an operation for inspecting an evaporative fuel leak from the fuel tank among operations of the processing system 10 will be described. Note that the inspection operation is not performed until a predetermined period elapses after the operation of the internal combustion engine mounted on the vehicle is stopped.

(1) In the reference characteristic detection period, communication between the tank flow path 140 and the pump flow path 160 between the first valve body 352 and the first valve seat 351 is interrupted by stopping energization of the coil 332, The tank channel 140 and the atmospheric channel 150 communicate with each other. As a result, the atmospheric flow path 150 communicates with the pump flow path 160 through the tank flow path 140 and the reference orifice 522 of the orifice flow path 510. Thereafter, when energization of the motor unit 220 is started, the vane pump 200 is started, so that the check valve 230 is opened and the pump flow path 160 and the orifice flow path 510 are depressurized. Due to this decompression, the air that flows from the atmospheric flow path 150 into the tank flow path 140 and the air that contains the evaporated fuel that flows from the canister 30 into the tank flow path 140 pass from the tank flow path 140 to the orifice flow path 510 through the end 516. Inflow. Further, the air flowing into the orifice channel 510 is guided to the reduced reference orifice 522 and is subjected to a throttling action, and then flows into the pump channel 160 and the valve channel 235. As a result, the valve member 232 vibrates according to the gas flow rate in the valve flow path 235, so that the vibration is detected by the strain sensor 400. Further, the average amplitude VA and the average frequency FA are calculated by the ECU 50 for the detected vibration, and the average amplitude VA and the average frequency FA are recorded in the ECU 50 as the amplitude reference value VAr and the frequency reference value FAr, respectively. Here, the average amplitude VA is an average value of the vibration amplitude Vi detected during the predetermined detection time Δt as shown in FIG. The average frequency FA is the reciprocal of the average value of the vibration period Ti detected during the detection time Δt as shown in FIG. The vibration detection during the reference characteristic detection period is not performed when the suction pressure is unstable, such as immediately after the vane pump 200 is started or stopped, and the suction pressure is relatively stable due to the steady operation of the vane pump 200. Will be implemented.
As described above, when the recording of the amplitude reference value VAr and the frequency reference value FAr is completed, the energization to the motor unit 220 is stopped.

  (2) In the comparison characteristic detection period subsequent to the reference characteristic detection period, the energization of the coil 332 blocks the communication between the tank flow path 140 and the atmospheric flow path 150, and the first valve body 352 and the first valve seat. The tank channel 140 and the pump channel 160 communicate with each other. Thereafter, when the vane pump 200 is activated by energization of the motor unit 220, the check valve 230 is opened. Further, by continuing the operation of the vane pump 200, the inside of the fuel tank 20 communicating with the pump flow path 160 is depressurized as time passes. As a result, the mixture of evaporated fuel and air flows into the tank flow path 140 at a flow rate corresponding to the opening area of the fuel tank 20 and further passes between the first valve body 352 and the first valve seat 351. It flows into the pump flow path 160 and the valve flow path 235. As a result, the valve member 232 vibrates according to the gas flow rate in the valve flow path 235, so that the vibration is detected by the strain sensor 400. Further, the average amplitude VA and the average frequency FA are calculated by the ECU 50 for the detected vibration as in the case of (1) above, and the average amplitude VA and the average frequency FA are set as the amplitude comparison value VAh and the frequency comparison value FAh, respectively. Is done. The vibration detection during the comparative characteristic detection period is not performed when the suction pressure is unstable, such as immediately after the vane pump 200 is started or stopped, and the suction pressure is relatively stable due to the steady operation of the vane pump 200. Will be implemented.

At this time, when the amplitude comparison value VAh is smaller than the reference amplitude value VAr recorded in the above (1), or when the frequency comparison value FAh is smaller than the frequency reference value FAr recorded in the above (1), The ECU 50 determines that the fuel vapor leakage from the fuel tank 20 is not more than an allowable value. On the other hand, when the comparison amplitude value VAh is larger than the reference amplitude value VAr, or when the frequency comparison value FAh is larger than the frequency reference value FAr, the ECU 50 determines that the fuel vapor leakage from the fuel tank 20 is excessively allowable. The If it is determined that the evaporation leakage is excessively allowable, for example, a warning lamp is lit on a dashboard (not shown) of the vehicle. As a result, the vehicle driver is warned that the evaporated fuel is leaking from the fuel tank 20.
When the determination of leakage is completed as described above, the energization to the motor 220 and the coil 332 is stopped, and the inspection operation ends.

  According to the processing apparatus 100 of this embodiment described above, the strain sensor 400 is installed on the outer wall of the valve body that does not come into contact with the gas containing the evaporated fuel in the valve flow path 235 to detect vibration. Therefore, it is not necessary to use the strain sensor 400 for coating the evaporated fuel, using a material resistant to the evaporated fuel, and the like. Further, since there is no need to lead the signal line 236 for outputting the detection signal of the strain sensor 400 from the inside of the housing 110 to the outside, no sealing is necessary. Further, unlike the evaporative fuel processing apparatus disclosed in Patent Document 1, a dedicated flow path for the pressure sensor that is required when the pressure sensor is used to detect the pressure characteristic value of the gas becomes unnecessary. As a result, the configuration of the fuel vapor processing apparatus can be simplified and the manufacturing can be facilitated.

Further, according to the processing apparatus 100, since the strain sensor 400 detects vibration during the steady operation of the vane pump 200, vibration detection can be performed with high accuracy in a state where the gas flow in the valve flow path 235 is stable. Moreover, in the processing apparatus 100, since the strain sensor 400 is installed on the outer wall of the cylindrical portion 233a close to the valve member 232 with the cylindrical portion 233a interposed therebetween, vibration of the valve member 232 is easily transmitted. Therefore, since a larger vibration can be detected, the detection accuracy is improved.
Furthermore, according to the processing apparatus 100, since the check valve 230 is installed in the vicinity of the suction port 210 of the vane pump 200, the vibration of the valve member 232 sufficiently reflects the flow of gas sucked by the vane pump 200. It can be big. This also improves the vibration detection accuracy.

Furthermore, according to the processing apparatus 100, the valve member 232 of the check valve 230 that opens the valve flow path 235 when the vane pump 200 is operated is a vibrating member that vibrates due to a gas flow. Thereby, the function of opening the valve flow path 235 during the operation of the vane pump 200 and the function of vibrating according to the gas flow can be realized by the same valve member 232. Such aggregation of functions into one member can reduce the cost.
In addition, according to the processing apparatus 100, the amplitude reference value VAr and the frequency reference value FAr are detected during the reference characteristic detection period, and the amplitude comparison value VAh and the frequency comparison value FAh are detected during the comparison characteristic detection period. Since the reference values VAr and FAr and the comparison values VAh and FAh detected in this way reflect the gas flow in the orifice passage 510 and the pump passage 160 communicating with the valve passage 235, the comparison result of these values. Based on this, it is possible to accurately determine the fuel vapor leakage from the fuel tank.

Although one embodiment of the present invention has been described so far, the present invention is not construed as being limited to such an embodiment, and can be applied to various embodiments without departing from the gist thereof.
For example, in the above-described embodiment, the vibration of the valve member 232 of the check valve 230 is detected by the strain sensor 400. On the other hand, for example, as shown in FIG. 5, a vibration member 600 having an elastic portion 601 as a vibration member is arranged in the pump flow path 160, and the vibration of the vibration member 600 is installed on the outer wall of the housing 110. You may detect indirectly by the distortion sensor 400. FIG. In addition to the strain sensor 400 as in the above-described embodiment, for example, a microphone that detects sound generated by vibration may be used as the vibration detection unit.

  Furthermore, in the above-described embodiment, the check valve 230 is disposed in the vicinity of the suction port 210 of the pump 200. On the other hand, for example, the check valve 230 may be disposed in the vicinity of the discharge port 211, or the check valve 230 is disposed in the pump flow path 160 or the discharge flow path 170 to be separated from the suction port 210 or the discharge port 211. May be.

  Further, as a pump, for example, a diaphragm pump may be used instead of the vane pump 200 as in the above-described embodiment. Further, as a steady operation of the pump, in addition to the operation of making the suction pressure or the discharge pressure constant as in the above-described embodiment, the operation of making the suction flow rate or the discharge flow rate constant may be adopted.

  In addition, in the above-described embodiment, the example in which the present invention is applied to an apparatus for performing a leak inspection by reducing the pressure of the pump flow path 160 has been described. However, the present invention is also applied to an apparatus for performing a leak inspection by pressurizing the pump flow path 160. Is possible. For example, in the above-described embodiment, the valve seat 233b side end from the valve member 232 of the valve flow path 235 is communicated with the discharge port 211 of the vane pump 200, and the valve seat 233b of the valve flow path 235 is connected to the valve. In this embodiment, the side end of the member 232 communicates with the pump flow path 160.

  In addition, in the above-described embodiment, the operation of inspecting the fuel vapor leakage from the fuel tank based on the vibration detection result has been described. However, the present invention is also applicable to the case where the concentration of the evaporated fuel is obtained based on the vibration detection result. Is applicable. In addition, the ECU 50 as a determination unit that determines a physical quantity such as evaporative fuel leakage based on the vibration detection result may be provided outside the processing apparatus 100 as in the above-described embodiment, or may be a part of the processing apparatus 100. It may be provided integrally with the processing apparatus 100 as a component.

It is sectional drawing which expands and shows the principal part of the evaporative fuel processing apparatus by one Embodiment of this invention. It is a mimetic diagram showing a schematic structure of an evaporation fuel processing system by one embodiment of the present invention. It is sectional drawing which shows the evaporative fuel processing apparatus by one Embodiment of this invention. It is a schematic diagram which shows the detection result of the distortion sensor by one Embodiment of this invention. It is sectional drawing which shows the modification of embodiment shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Fuel tank, 100 Evaporative fuel processing apparatus, 110 Housing (flow path member), 140 Tank flow path (flow path), 160 Pump flow path (flow path), 170 Discharge flow path (flow path), 200 Vane pump (pump) , 210 Suction port, 211 Discharge port, 232 Valve member (vibrating member), 233 Valve body (flow path member, enclosing part), 233a Tube part (enclosing part), 233b Valve seat part (enclosing part), 235 Valve flow path (Flow path), 400 strain sensor (vibration detection means), 510 orifice flow path (flow path), 522 reference orifice, 600 vibration member

Claims (9)

A flow path member that communicates with the fuel tank and forms a flow path in which a gas containing evaporated fuel generated in the fuel tank flows;
A pump having a suction port or a discharge port communicating with the flow path;
A vibrating member that is disposed in the flow path and vibrates according to the flow of the gas sucked or discharged by the pump;
Vibration detection means installed outside the flow path member and detecting a vibration of the vibration member and outputting a detection signal;
An evaporative fuel processing apparatus comprising:   The evaporated fuel processing apparatus according to claim 1, wherein the vibration detecting unit detects the vibration during steady operation of the pump. The flow path member has a surrounding portion surrounding an outer peripheral side of the vibration member,
The evaporated fuel processing apparatus according to claim 1, wherein the vibration detection unit is installed on an outer peripheral wall of the enclosure.   The evaporative fuel processing apparatus according to claim 1, wherein the vibration member is installed in the vicinity of the suction port or the discharge port that communicates with the flow path.   The evaporated fuel processing apparatus according to any one of claims 1 to 4, wherein the vibration member is a valve member that opens the flow path and vibrates by the flow of the gas when the pump is operated. The flow path has an orifice flow path in which a reference orifice is installed, and a tank flow path communicating with the fuel tank,
The vibration detection means detects the vibration generated when the pump communicates with the orifice flow path as a reference characteristic, and detects the vibration generated when the pump communicates with the tank flow path from the fuel tank. The evaporative fuel processing apparatus according to claim 1, wherein the evaporative fuel treatment apparatus detects the evaporative fuel leakage as a comparison characteristic compared with the reference characteristic.   The evaporated fuel processing apparatus according to claim 1, wherein the vibration detection unit detects an amplitude of the vibration.   The evaporated fuel processing apparatus according to claim 1, wherein the vibration detection unit detects an amplitude and a frequency of the vibration. The evaporated fuel processing apparatus according to claim 1, wherein the vibration detection unit is a strain sensor that detects strain generated in the flow path member when the vibration is transmitted to the flow path member. .

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