JP2007218161A - Vane type pump device and leak check system using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vane type pump device eliminating adhesion of a rotor and a vane, and a leak check system using the same. <P>SOLUTION: The pump 60 is a vane type pump in which an electric drive type motor drives and rotates the rotor and the vane. Since the pump 60 is connected to an atmosphere side via a detection passage 206, an atmosphere passage 204, a change over valve 30, an atmosphere passage 208, and a filter 92 under a condition where electricity carry to the change over valve 30 is turned off, pressure detected by a pressure sensor 90 with the pump 60 driven is reference pressure Pref determined by orifice diameter of a reference orifice 52a. ECU 100 judges that the vane adheres on the rotor of the pump 60 due to condensation or the like and that the pump 60 is not normally operating when detected reference pressure Pref is out of a normal range P1 to atmospheric pressure side and motor current value is larger than a normal range I1. Then, the pump 60 is driven until condensation is eliminated and the detected reference pressure Pref reaches the normal range P1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vane-type pump device that depressurizes or pressurizes gas and a leak check system using the same.

2. Description of the Related Art Conventionally, in a leak check system for checking an evaporation system leak that purges evaporated fuel generated in a fuel tank into an intake passage, a pump is driven to depressurize or pressurize the evaporation system, and based on the detected evaporation system pressure It is known to perform a leak check (see, for example, Patent Document 1).
As a pump for depressurizing or pressurizing the gas in this way, it is conceivable to use a vane pump in which the rotor is housed eccentrically with respect to the housing and the vane is housed in the rotor so as to be capable of reciprocating in the radial direction. In the vane pump, when the rotor that is eccentric with respect to the housing rotates, the vane is pressed against the inner peripheral surface of the housing by centrifugal force and slides along the inner peripheral surface of the housing. The gas is depressurized or pressurized while reciprocating.

  However, in such a vane type pump, for example, if the vane adheres to the rotor of the pump due to dew condensation caused by the temperature and humidity of the surrounding environment, the vane does not jump out radially outward due to centrifugal force, but along the inner peripheral surface of the housing. This prevents the vane from sliding with the inner peripheral surface of the housing. In this state, the vane pump cannot sufficiently depressurize or pressurize the gas.

JP 2002-364465 A

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a vane type pump device that eliminates adhesion between a rotor and a vane and a leak check system using the same.

  According to the first to fourth aspects of the present invention, when it is determined from the detection signal of the pressure sensor when the motor is driven and the motor current that the vane is attached to the rotor, the motor is driven. Eliminates vane adhesion to the rotor. Thereby, the vane type pump device can depressurize or pressurize the gas to a desired pressure in a state where the adhesion of the vane to the rotor is eliminated.

According to the third aspect of the present invention, if it is determined that the vane is abnormally attached to the rotor, the number of rotations of the motor is increased as compared with that during normal operation. it can.
According to the fourth aspect of the invention, it is determined that the vane is abnormally attached to the rotor from the detection signal of the pressure sensor and the motor current when the vane pump device is driven and the reference pressure is detected. Then, the motor is driven to rotate to eliminate the adhesion of vanes to the rotor. Therefore, it is possible to accurately detect the reference pressure in a state where vane adhesion to the rotor is eliminated.

  The functions of the plurality of means provided in the present invention are realized by hardware resources whose functions are specified by the configuration itself, hardware resources whose functions are specified by a program, or a combination thereof. Further, the functions of the plurality of means are not limited to those realized by hardware resources that are physically independent of each other.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In FIG. 1, the fuel tank 10 and the canister 12 are connected by a passage 200, and the canister 12 and the intake passage 16 are connected by a purge passage 202. A purge valve 14 is installed in the purge passage 202. The evaporated fuel generated in the fuel tank 10 passes through the passage 200 and is adsorbed by an adsorbent such as activated carbon in the canister 12. The purge valve 14 is an electromagnetic valve, and the amount of evaporated fuel purged from the canister 12 to the intake passage 16 is adjusted by controlling the opening of the purge valve 14.

  The leak check system according to an embodiment of the present invention includes a pump module 20 and an electronic control unit (hereinafter referred to as ECU) 100 as a control unit and a determination unit. The leak check system performs an evaporative leak check including the fuel tank 10, the canister 12, the purge valve 14, the passage 200, and the purge passage 202.

  The atmospheric side of the canister 12 is connected to the switching valve 30 of the pump module 20 by an atmospheric passage 204. Further, the atmosphere side of the canister 12 is connected to the pump 60 of the pump module 20 by a detection passage 206 branched from the atmosphere passage 204. The pump 60 is a vane pump. A reference orifice 52 a is formed in the detection passage 206.

  The pump module 20 is a module in which the switching valve 30 and the pump 60 are integrally formed. The pump module 20 and the ECU 100 constitute a vane type pump device. The switching valve 30 of the pump module 20 is an electromagnetic valve, and communicates the atmosphere passage 204 and the atmosphere passage 208 as shown in FIG. A filter 92 is installed at the end of the atmospheric passage 208 opposite to the switching valve 30. When energization of the coil 36 is turned on, the switching valve 30 directly connects the canister 12 side and the pump 60 side via the atmospheric passage 204 without passing through the detection passage 206.

(Pump module 20)
Next, the configuration of the pump module 20 will be described in detail with reference to FIG.
In the pump module 20, the above-described atmospheric passages 204 and 208 and the detection passage 206 are formed. The atmospheric passage 204 and the detection passage 206 are always in communication. A cup member 52 that forms a reference orifice 52 a is installed in the canister port 50 that forms part of the detection passage 206. When the hole having the same flow area as the reference orifice 52a is open to the evaporation system, the reference orifice 52a is formed for pressure determination for detecting the pressure reached by the evaporation system when the evaporation system is depressurized from the pump 60. ing. Filters 54 are respectively installed on the upstream and downstream sides of the reference orifice 52a.

(Switching valve 30)
As described above, the switching valve 30 of the pump module 20 is a solenoid valve. The movable core 34 of the switching valve 30 is installed facing the fixed core 32. A shaft 40 is attached to the movable core 34, and rubber valve members 42 and 43 are installed on the shaft 40 so as to be separated from each other in the axial direction. In the state where the power supply to the coil 36 shown in FIG. 2 is turned off, the valve member 42 closes the canister port 50 and the valve member 43 opens the atmosphere port 56. In this state, the atmospheric passage 204 and the atmospheric passage 208 communicate with each other, and the detection passage 206 communicates with the atmospheric passage 208 through the atmospheric passage 204. When energization of the coil 36 is turned on, the movable core 34 moves toward the fixed core 32 on the upper side in FIG. 2 by the magnetic attractive force acting between the fixed core 32 and the movable core 34. Then, the valve member 42 opens the canister port 50, and the valve member 43 closes the atmosphere port 56. In this state, the atmosphere passage 204 and the pump 60 side communicate directly with each other without the detection passage 206, and the communication between the atmosphere passage 204 and the atmosphere passage 208 is blocked.

(Pump 60)
The pump 60 of the pump module 20 is a vane type, and an electrically driven motor 62 drives the rotor 70 to rotate. The rotor 70, the vane 72, and the housing 74 of the pump 60 are made of resin. The rotor 70 is formed with, for example, four slits extending in the radial direction at substantially equal intervals in the circumferential direction, and a plate-like vane 72 is accommodated in each slit so as to be capable of reciprocating in the radial direction. The rotor 70 is housed in an annular housing 74 so as to be eccentric and rotatable with respect to the housing 74. When the rotor 70 that is eccentric with respect to the housing 74 is driven to rotate by the motor 62, the vane 72 that receives a force radially outward due to the centrifugal force is aligned with the inner peripheral surface of the housing 74 along the inner peripheral surface of the housing 74. Reciprocates in the radial direction while sliding. A filter 82 is installed at the suction port 80 of the pump 60. The pressure sensor 90 detects the pressure on the suction port 80 side of the pump 60. In the pump 60 having such a configuration, when the rotor 70 rotates and the vane 72 reciprocates in the radial direction, the atmospheric passage 204 or the detection passage 206 is decompressed.

  The ECU 100 has a CPU, a ROM, an I / O interface, and the like. The ECU 100 controls the drive signal of the motor 62 that drives the switching valve 30 of the pump module 20 and the pump 60 by the CPU executing the control program recorded in the ROM, and inputs the pressure detection signal from the pressure sensor 90. .

(Leak check)
Next, the operation of the leak check system will be described.
(1) First, in the period [A] in FIG. 3, the ECU 100 detects the atmospheric pressure from the detection signal of the pressure sensor 90 with the energization to the switching valve 30 and the motor 62 of the pump 60 turned off. For example, when the vehicle is at a high altitude and the pressure detected by the pressure sensor 90 is lower than a predetermined pressure, the leak check itself may not be performed. Further, the atmospheric pressure detected by the pressure sensor 90 may be used as a correction value when determining the pressure value in the subsequent leak check.

  (2) Next, as shown in step 300 of FIG. 7, the ECU 100 turns on the power to the motor 62 and drives the pump 60 in the state shown in FIG. 1 where the power to the switching valve 30 is turned off. In this case, the pump 60 is connected to the atmosphere side via the detection passage 206, the atmosphere passage 204, the switching valve 30, the atmosphere passage 208, and the filter 92. Therefore, the pressure detected by the pressure sensor 90 when the pump 60 is driven is the reference pressure Pref determined by the orifice diameter of the reference orifice 52a (see period 302 in FIG. 3, step 302).

  (3) The ECU 100 determines the detected reference pressure Pref in step 304 of FIG. If the reference pressure Pref is within the normal range P1 as shown in FIG. 4, ECU 100 turns on the switching valve 30 in step 306. Thereby, the switching valve 30 directly communicates the air passage 204 on the pump 60 side and the canister 12 side and blocks communication between the air passage 204 and the air passage 208.

  In the leak pressure check at step 308, the ECU 100 drives the pump 60 to reduce the evaporation system including the fuel tank 10, the canister 12, the purge valve 14, the passage 200, the purge passage 202, and the fuel tank 10. In step 308, the ECU 100 compares the detected pressure detected by the pressure sensor 90 with the graph 220 in FIG. 3 and determines whether or not there is a leak larger than the passage area of the reference orifice 52 a in the evaporation system. A graph 222 in the period [C] in FIG. 3 shows a change in pressure when the evaporation system has a hole having the same passage area as that of the reference orifice 52a. When the detected pressure of the pressure sensor 90 is lower than the graph 220 as shown in the graph 222, the ECU 100 determines that there is a leak with a passage area smaller than the reference orifice 52a in the evaporation system. On the other hand, when the detected pressure of the pressure sensor 90 is higher than the graph 220 as in the graph 224, the ECU 100 determines that there is a leak with a passage area larger than the reference orifice 52a in the evaporation system.

  (4) By the way, when the reference pressure Pref determined in step 304 is high outside the normal range P1 as shown in FIGS. 5 and 6, the ECU 100 determines the current value flowing in the motor 62 of the pump 60 in step 310. And the motor current value is determined in step 312. As shown in FIG. 5, when the motor current value is low even in the normal range I1, the load applied to the pump 60 other than the evaporation system, for example, due to a sealing failure of the switching valve 30, etc. becomes small, and the current value decreases. This is considered to be the cause. In this case, since maintenance work such as replacement of the switching valve 30 is necessary, the leak check is canceled in step 320 and the routine shown in FIG. 7 is terminated.

  On the other hand, as shown in FIG. 6, when the detected reference pressure Pref is high outside the normal range P1 and the motor current value is larger than the normal range I1, the ECU 100 first detects the detected reference pressure Pref from the normal range P1. The reason for the high deviation is that the vane 72 adheres to the rotor 70 of the pump 60 due to condensation, etc., and even if centrifugal force is applied, the vane 72 cannot move radially outward, and the detection passage 206, that is, the reference orifice 52a is sufficiently decompressed. Judge that it is impossible. Further, the ECU 100 determines that the motor current value being larger than the normal range I1 is due to the fact that the surface tension due to condensation acts between the rotor 70 and the housing 74 and a large load is applied to the motor 62. .

  (5) As shown in FIG. 6, when ECU 100 determines from the detected reference pressure Pref and the motor current value that there is an abnormality due to condensation, in step 314, ECU 100 turns on power to motor 62 of pump 60 and turns on the pump. 60 is driven. In this way, by driving the pump 60 at a timing other than the normal timing of the leak check and rotating the rotor 70, dew condensation is eliminated by the sliding heat between the rotor 70 and the housing 74. The ECU 100 drives the pump 60 in step 314, determines the detected pressure of the pressure sensor 90 in steps 316 and 318, and performs the processing in steps 310, 312, 314, 316 and 318 until the detected pressure reaches the normal range P1. repeat. At this time, the dew condensation of the pump 60 can be eliminated in a short time by increasing the rotation speed of the motor 62 above the rotation speed at the normal time. If the detected pressure reaches the normal range P1 in step 318, it is determined that the motor current value has also reached the normal range I1, and the process proceeds to step 306 to check the evaporation system leak pressure.

  In the present embodiment described above, the motor current value is determined when the detected pressure of the reference pressure Pref is out of the normal range P1, thereby condensing the cause of the detected pressure of the reference pressure Pref out of the normal range P1. Judge that. This prevents the vane 72 from adhering to the rotor 70 of the pump 60 due to condensation and preventing the process from proceeding to step 306 in a state where the pump 60 cannot sufficiently depressurize, thereby preventing erroneous determination of leak check. Also, if it is determined that the cause of the detected pressure of the reference pressure Pref being out of the normal range P1 is due to condensation, the pump 60 is driven at a timing other than the normal timing to eliminate condensation, so the leak check is normally performed after condensation is eliminated. it can.

(Other embodiments)
In the above embodiment, the motor 62 is driven until the pressure detected by the pressure sensor 90 reaches the normal range P1 to eliminate condensation. On the other hand, the condensation of the pump 60 may be eliminated by setting a timer value longer than a normal timer value for detecting the reference pressure and driving the motor 62 for a long time.
In the above embodiment, the vane pump device of the present invention is used for the leak check system. However, in addition to the leak check system, any type of vane pump device can be used as long as the pump depressurizes or pressurizes gas. You may use the vane type pump apparatus of this invention for a use.

Moreover, when using the vane type pump apparatus of this invention for a leak check system like the said embodiment, you may pressurize an evaporation system and perform a leak check.
As described above, the present invention is not limited to the above-described embodiment, and can be applied to various embodiments without departing from the gist thereof.

The typical block diagram which shows the leak check system by this embodiment. Sectional drawing which shows a pump module. Leak check time chart. The characteristic view which shows the reference pressure and motor current at the time of normal. The characteristic view which shows the reference pressure and motor current at the time of abnormality. The characteristic view which shows the reference pressure and motor current at the time of abnormality which dew condensation has generate | occur | produced. The flowchart of a leak check.

Explanation of symbols

10: fuel tank, 12: canister, 14: purge valve, 16: intake passage, 20: pump module, 30: switching valve (vane pump device), 52a: reference orifice, 60: pump (vane pump, vane type) Pump device), 62: motor, 70: rotor, 72: vane, 74: housing, 90: pressure sensor, 100: ECU (control means, determination means, vane pump device)

Claims (4)

In a vane-type pump device that depressurizes or pressurizes gas,
A motor,
A housing;
A rotor that is eccentric with respect to the housing and rotatably accommodated in the housing, and is driven to rotate by the motor;
A vane which is accommodated in the rotor so as to be reciprocally movable in the radial direction, and whose radially outer end slides with the inner peripheral surface of the housing as the rotor rotates.
A pressure sensor for detecting a pressure of a gas that is depressurized or pressurized by rotation of the rotor and the vane;
When it is determined from the detection signal of the pressure sensor when the motor is driven and the current of the motor that the vane is abnormally attached to the rotor, the motor is driven to the vane to the rotor. Control means to eliminate the adhesion of,
A vane-type pump device.   When the pressure indicated by the detection signal of the pressure sensor is closer to the atmospheric pressure than the normal range and the current of the motor is larger than the normal range, the control means has the vane attached to the rotor. The vane pump device according to claim 1, wherein the vane pump device is determined to be abnormal.   3. The vane pump device according to claim 1, wherein when the control means determines that the vane is abnormally attached to the rotor, the control unit increases the rotational speed of the motor more than during normal operation. In the evaporative leak check system that purges the evaporated fuel generated in the fuel tank into the intake passage of the internal combustion engine,
The vane pump device according to any one of claims 1 to 3, wherein the evaporation system is depressurized or pressurized.
A reference orifice for detecting a reference pressure when judging the leakage of the evaporation system;
A determination means for comparing the pressure detected by the pressure sensor with the reference pressure when the vane pump device depressurizes or pressurizes the evaporation system, and for determining leakage of the evaporation system;
With
The leak check system, wherein the control means determines that the vane is abnormally attached to the rotor from a detection signal of the pressure sensor when detecting the reference pressure and a current of the motor.

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