JP5282633B2 - Water pump failure diagnosis device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately diagnose a failure of a water pump which can be variably controlled by an electromagnetic clutch. <P>SOLUTION: This failure diagnostic device for a variable controllable water pump includes: a pulley 14 rotating, accompanying rotation of an engine; a magnetic coil 24 generating magnetic force by electricity supply; a permanent magnet 22 generating magnetic force resisting magnetic force generated by the magnetic coil 24; and an armature 20 rotating together with an impeller 18 and changing a state of engagement with a pulley 14 in response to magnetic force generated by the magnetic coil 24. In the failure diagnostic device for the water pump, a failure determination means 70 determining a failure of the water pump 10 if current is not induced in the magnetic coil 24 when electricity supply to the magnetic coil 24 is stopped is included. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a water pump failure diagnosis apparatus.

  The cooling of the engine using the cooling water is performed by circulating the cooling water using a water pump. The water pump is generally driven by the rotation of an engine transmitted through a belt or the like. Conventionally, a method has been proposed in which the water pump can be variably controlled by controlling transmission / interruption of engine rotation to the water pump using an electromagnetic clutch (for example, Patent Document 1).

  Further, as a method for diagnosing whether or not such an electromagnetic clutch has failed, a method of diagnosing the failure of the electromagnetic clutch based on the magnitude of the current flowing through the electromagnetic coil provided in the electromagnetic clutch has been proposed (for example, Patent Document 2).

JP 2004-293430 A JP-A-3-325

  The electromagnetic coil used for the electromagnetic clutch may be deteriorated depending on the usage environment. In addition, electric leakage may occur in the electric circuit connected to the electromagnetic coil. For this reason, in the method of diagnosing the failure of the electromagnetic clutch based on the value of the current flowing through the electromagnetic coil as in Patent Document 2, for example, when the electromagnetic coil is deteriorated, a sufficient engagement force is applied to the clutch. It is difficult to grasp whether or not it is working, and it is impossible to accurately diagnose the failure of the electromagnetic clutch.

  In addition, since the power consumption of the electromagnetic coil varies depending on changes in the temperature environment or the like, the electromagnetic clutch failure may be erroneously diagnosed particularly in a structure in which the water pump is variable during engine warm-up.

  In addition, a method of checking the operation of the electromagnetic clutch and diagnosing a failure of the electromagnetic clutch by directly measuring the movement of the clutch with a position sensor is conceivable, but in this case, the relationship between the clutch engagement force and the clutch position is considered. There is a problem that the correlation is low.

  Therefore, with the method described above, it is difficult to accurately diagnose a failure of a water pump provided with an electromagnetic clutch.

  An object of the present invention is to enable accurate fault diagnosis of a water pump that can be variably controlled by an electromagnetic clutch.

The above-described object resists a rotating member that rotates as the engine rotates, an electromagnetic coil that generates a magnetic force when energized, a current control unit that controls energization of the electromagnetic coil, and a magnetic force generated by the electromagnetic coil. A fault diagnosing device for a variably controllable water pump, comprising: a first permanent magnet that generates a magnetic force; and an armature that rotates together with an impeller and changes an engagement state with the rotating member in accordance with the magnetic force generated by the electromagnetic coil. And when the current control means stops energization to the electromagnetic coil, it has a failure judging means for judging that the water pump is faulty when no induced current is generated in the electromagnetic coil. This is accomplished by a fault diagnosis device for the water pump.

  According to this, since the failure determination of the water pump is performed based on the magnetic force of the magnetic circuit including the permanent magnet and the electromagnetic coil, it is possible to accurately determine the failure of the water pump.

  The said structure WHEREIN: The said armature can be set as the structure provided with the 2nd permanent magnet. According to this configuration, since the slip between the rotating member and the armature can also be grasped, the failure determination of the water pump can be performed more accurately.

The object is to rotate with the rotation of the engine, an electromagnetic coil for generating a magnetic force by energization, current control means for controlling energization to the electromagnetic coil, and an electromagnetic coil that rotates with an impeller to generate the electromagnetic coil. A variable-controllable water pump failure diagnosis device having an armature whose engagement state changes with the rotating member according to the magnetic force, and measuring the magnitude of the magnetic force of the magnetic circuit including the electromagnetic coil A failure determination unit that determines a failure of the water pump based on a change in a measured value measured by the magnetic force measurement unit when the energization state of the electromagnetic coil is changed by the current control unit; have a, the electromagnetic coil generates a magnetic force against the magnetic force to be generated further a third permanent magnet to attract the armature to the rotary member side The magnetic force measurement means measures the magnitude of the magnetic force of the magnetic circuit including the electromagnetic coil and the third permanent magnet, and the failure determination means has the measured value measured by the magnetic force measurement means. A failure diagnosis of a water pump characterized by determining that the water pump has failed when the electromagnetic coil does not rise when energization is stopped or when the electromagnetic coil rises when the electromagnetic coil is energized Achieved with the device.

  According to this, since the failure determination of the water pump is performed based on the magnetic force of the magnetic circuit including the electromagnetic coil, it is possible to accurately determine the failure of the water pump.

Further , according to this configuration, since the water pump failure is determined based on the magnetic force of the magnetic circuit including the permanent magnet and the electromagnetic coil, it is possible to accurately determine the water pump failure.

  In the above configuration, the magnetic force measuring means measures the direction of the magnetic force of the magnetic circuit including the electromagnetic coil and the third permanent magnet, and the failure determining means is the direction of the magnetic force measured by the magnetic force measuring means. Based on the above, the third permanent magnet can be judged for deterioration. According to this configuration, it is possible to determine the deterioration of the third permanent magnet.

  In the above-described configuration, the magnetic force measuring means measures the magnitude of the magnetic force of the magnetic circuit in each of the case where the electromagnetic coil is energized and the case where the energization of the electromagnetic coil is stopped, and the failure determination The means compares the measured value measured by the magnetic force measuring means with a predetermined value in each case when the electromagnetic coil is energized and when the energization to the electromagnetic coil is stopped. It can be set as the structure which determines the deterioration of the said electromagnetic coil or the said 3rd permanent magnet. According to this configuration, it is possible to determine which of the electromagnetic coil and the third permanent magnet is deteriorated.

  The said structure WHEREIN: The said armature can be set as the structure which is a magnet. According to this configuration, since the magnitude of the magnetic force of the magnetic circuit is increased, it is possible to easily determine the failure of the water pump.

  According to the present invention, since the failure determination of the water pump is performed based on the magnetic force of the magnetic circuit, it is possible to accurately determine the failure of the water pump.

FIG. 1 is a schematic diagram illustrating a water pump to which a water pump failure diagnosis apparatus according to the first embodiment is connected. FIG. 2A is a diagram illustrating a case where the armature and the pulley are engaged, and FIG. 2B is a diagram illustrating a case where the armature and the pulley are opened. FIG. 3 is a flowchart for explaining a failure diagnosis process of the water pump failure diagnosis apparatus according to the first embodiment. FIG. 4 is a diagram illustrating a case where a permanent magnet is not used. FIG. 5 is a schematic diagram illustrating a water pump to which a water pump failure diagnosis apparatus according to the second embodiment is connected. FIG. 6 is a flowchart (part 1) illustrating a failure diagnosis process of the water pump failure diagnosis apparatus according to the second embodiment. FIG. 7 is a flowchart (part 2) for explaining the failure diagnosis process of the water pump failure diagnosis apparatus according to the second embodiment. FIG. 8 is a diagram for explaining the armature.

  Hereinafter, embodiments of the water pump failure diagnosis apparatus of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram illustrating a water pump 10 connected to a water pump failure diagnosis apparatus 100 according to the first embodiment. As illustrated in FIG. 1, the water pump failure diagnosis apparatus 100 according to the first embodiment includes a magnetic sensor 50 as a magnetic force measurement unit and an ECU 60. The water pump 10 has a cylindrical pulley 14 that rotates when the rotation of the engine is transmitted by the belt 12, and an annular armature 20 that is disposed to face one surface 16 of the pulley 14 and rotates together with the impeller 18. And a permanent magnet 22 and an electromagnetic coil 24 provided in the pulley 14. In addition, although the pulley 14 is mentioned as an example as a rotating member that rotates with the rotation of the engine, in addition to the pulley 14, for example, a gear or other member that rotates with the rotation of the engine may be used. Can be used.

  A housing 30 is fitted into a hollow portion 26 formed in the center of the cylindrical pulley 14 via a pulley bearing 32. The housing 30 is provided with a through hole 28 at the center. The pulley bearing 32 enables the pulley 14 to rotate with respect to the housing 30, and the pulley 14 rotates around the housing 30 by the rotation of the engine transmitted through the belt 12.

  A shaft 38 is fitted into the through hole 28 via a shaft bearing 36. An impeller 18 is provided at one end of the shaft 38, and an armature 20 is provided at the other end of the shaft 38 via a leaf spring 40. The armature 20 is made of a magnetic material such as iron. The shaft bearing 36 allows the shaft 38 to rotate with respect to the housing 30.

  The permanent magnet 22 has an annular shape and generates a magnetic force in a direction that pulls the armature 20 toward the pulley 14. The electromagnetic coil 24 is also annular, and generates a magnetic force that resists the magnetic force generated by the permanent magnet 22 when energized. That is, a magnetic force is generated from the electromagnetic coil 24 in a direction that separates the armature 20 from the pulley 14. Further, the spring force of the leaf spring 40 acts in a direction in which the armature 20 is pulled away from the pulley 14.

  Here, the case where the armature 20 and the pulley 14 are engaged will be described with reference to FIG. As shown in FIG. 2A, when the electromagnetic coil 24 is not energized, the armature 20 is subjected to a magnetic force by the permanent magnet 22 and a spring force by the leaf spring 40. The magnetic force of the permanent magnet 22 is a force that acts in a direction that pulls the armature 20 toward the pulley 14, and the spring force of the leaf spring 40 is a force that acts in a direction that pulls the armature 20 away from the pulley 14.

  Here, the magnetic force of the permanent magnet 22 and / or the spring force of the leaf spring 40 is adjusted so that the magnetic force of the permanent magnet 22 is larger than the spring force of the leaf spring 40. Thus, when the electromagnetic coil 24 is not energized, the armature 20 is drawn toward the pulley 14 and is engaged with the pulley 14.

  As the armature 20 and the pulley 14 are engaged, the armature 20 also rotates together with the pulley 14 by the rotation of the engine. For this reason, the impeller 18 connected to the armature 20 also rotates together with the armature 20, and the water pump 10 enters a driving state.

  Next, the case where the armature 20 and the pulley 14 are opened will be described with reference to FIG. As shown in FIG. 2B, when the electromagnetic coil 24 is energized, a magnetic force that resists the magnetic force of the permanent magnet 22 is generated from the electromagnetic coil 24. For this reason, in addition to the magnetic force by the permanent magnet 22 and the spring force by the leaf spring 40, the magnetic force from the electromagnetic coil 24 acts on the armature 20.

  Here, the magnetic force of the permanent magnet 22, the spring force of the plate spring 40, and / or the electromagnetic force so that the resultant force of the spring force of the plate spring 40 and the magnetic force of the electromagnetic coil 24 is greater than the magnetic force of the permanent magnet 22. The magnetic force of the coil 24 is adjusted. As a result, when the electromagnetic coil 24 is energized, the armature 20 is pulled away from the pulley 14 and released from the pulley 14. Thereby, even if the pulley 14 rotates due to the rotation of the engine, the armature 20 does not rotate, so the impeller 18 does not rotate and the water pump 10 is stopped.

  Returning to FIG. 1, the magnetic sensor 50 measures the magnitude and direction of the magnetic force of the magnetic circuit including the permanent magnet 22 and the electromagnetic coil 24. The magnetic sensor 50 generates an electromotive force by the input magnetic flux and outputs the electromotive force to the ECU 60. Since the magnitude of the electromotive force is proportional to the magnitude of the magnetic flux, the magnitude of the magnetic force of the magnetic circuit can be grasped by measuring the magnitude of the electromotive force generated by the magnetic sensor 50. Further, since the direction of the electromotive force generated by the magnetic sensor 50 also changes depending on the direction of the magnetic flux, the direction of the magnetic force of the magnetic circuit can be grasped by measuring the direction of the electromotive force.

  The ECU 60 comprises a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc., and has elapsed time determination means 62, water stop area determination means 64, current control means 66, current measurement means. 68, a failure determination means 70 is provided. The ECU 60 is driven by a voltage supplied from the battery 80.

  The elapsed time determination means 62 determines whether a predetermined time has elapsed since the engine was started.

  The water stop region determination means 64 is a water stop when the elapsed time determination means 62 determines that the predetermined time has elapsed, when the temperature of the cooling water is low, or when the engine load is light. It is determined whether or not the area is applicable.

  The current control unit 66 controls energization to the electromagnetic coil 24 by controlling the relay switch 72. Specifically, by controlling the current supply to the coil 74 in the relay switch 72, the switch 76 is controlled to be turned ON / OFF, and the energization to the electromagnetic coil 24 is controlled. The negative terminal of the electromagnetic coil 24 and the negative terminal of the coil 74 are grounded by the housing 30.

  The current measuring unit 68 measures the magnitude and direction of the current generated by the electromotive force generated by the magnetic sensor 50. As described above, the magnitude and direction of the magnetic force of the magnetic circuit can be grasped by measuring the magnitude and direction of the current.

  The failure determination means 70 determines failure of the water pump 10 based on the change in electromotive force measured by the magnetic sensor 50 when the energization state of the electromagnetic coil 24 is changed. Specifically, as shown in FIG. 2A, the current value measured by the current measuring means 68 when the energization to the electromagnetic coil 24 is stopped is compared with that when the electromagnetic coil 24 is energized. If the water pump 10 does not rise, it is determined that the water pump 10 has failed. In addition, as shown in FIG. 2B, the current value measured by the current measuring means 68 when the electromagnetic coil 24 is energized is increased compared to when the energization of the electromagnetic coil 24 is stopped. In this case, it is determined that the water pump 10 has failed.

  Further, the failure determination unit 70 determines the deterioration of the permanent magnet 22 based on the direction of the current measured by the current measurement unit 68. Further, the failure determination unit 70 compares the current value measured by the current measurement unit 68 with a predetermined value in each case when the electromagnetic coil 24 is energized and when the energization is stopped. The deterioration of the magnet 22 or the electromagnetic coil 24 is determined.

  Next, a failure diagnosis process for the water pump 10 performed by the ECU 60 of the water pump failure diagnosis apparatus 100 according to the first embodiment will be described with reference to the flowchart of FIG.

  As shown in FIG. 3, after the engine is started (step S10), the ECU 60 determines whether a predetermined time α seconds has elapsed since the engine was started (step S12).

  When it is determined in step S12 that the predetermined time α seconds has not elapsed (in the case of No), the ECU 60 makes a round of the cooling water in the water gallery to equalize and stabilize the water temperature. Is driven (step S14). Specifically, the ECU 60 controls the relay switch 72 to stop energization of the electromagnetic coil 24. As a result, as shown in FIG. 2A, the armature 20 is engaged with the pulley 14 by the magnetic force of the permanent magnet 22, and the impeller 18 rotates together with the armature 20 according to the rotation of the pulley 14 caused by the rotation of the engine. That is, the water pump 10 is driven.

  Next, the ECU 60 measures the current value based on the electromotive force generated by the magnetic sensor 50 when the energization of the electromagnetic coil 24 is stopped (step S16). Next, the ECU 60 determines whether the current value measured in step S16 is higher than the current value based on the electromotive force generated by the magnetic sensor 50 when the electromagnetic coil 24 is energized (step S18). .

  Here, as described in FIGS. 2A and 2B, when the electromagnetic coil 24 is energized, the magnetic sensor 50 receives the magnetic flux from the permanent magnet 22 and the electromagnetic coil 24. Is done. Since the permanent magnet 22 and the electromagnetic coil 24 generate magnetic fluxes that oppose each other, an electromotive force corresponding to the difference magnetic flux is generated from the magnetic sensor 50.

  On the other hand, when energization to the electromagnetic coil 24 is stopped, only the magnetic flux from the permanent magnet 22 is input to the magnetic sensor 50. Therefore, an electromotive force corresponding to the magnetic flux of the permanent magnet 22 is generated from the magnetic sensor 50.

  That is, the current value based on the electromotive force generated by the magnetic sensor 50 is larger when the current supply to the electromagnetic coil 24 is stopped than when the current is supplied to the electromagnetic coil 24.

  Therefore, when it is determined in step S18 that the current value has increased (in the case of Yes), it can be determined that the magnetic force is generated only from the permanent magnet 22 and the armature 20 and the pulley 14 are engaged. Determines that the water pump 10 is operating normally (step S20).

  On the other hand, when it is determined in step S18 that the current value has not increased (in the case of No), it is determined that the magnetic force continues to be generated from the electromagnetic coil 24 and the armature 20 and the pulley 14 are not engaged. Therefore, the ECU 60 determines that the water pump 10 has failed (step S22).

  When it is determined in step S12 that the predetermined time α seconds has elapsed (in the case of Yes), the ECU 60 determines a water stop region such as when the temperature of the cooling water is low or the engine is in a light load state. (Step S24).

  If it is determined in step S24 that it belongs to the water stop region (in the case of Yes), the cooling water is in a low temperature state or the engine is in a light load state, so that the water pump 10 does not circulate in the water gallery. Is stopped (step S26). Specifically, the ECU 60 controls the relay switch 72 to energize the electromagnetic coil 24. As a result, as shown in FIG. 2B, the armature 20 is released from the pulley 14, so that the impeller 18 does not rotate even if the pulley 14 rotates. That is, the water pump 10 is stopped.

  Next, the ECU 60 measures a current value based on the electromotive force generated by the magnetic sensor 50 when the electromagnetic coil 24 is energized (step S28). Next, the ECU 60 determines whether the current value measured in step S28 is higher than the current value based on the electromotive force generated by the magnetic sensor 50 when the energization of the electromagnetic coil 24 is stopped ( Step S30).

  As described above, the current value based on the electromotive force generated by the magnetic sensor 50 is smaller when the electromagnetic coil 24 is energized than when the current supply to the electromagnetic coil 24 is stopped.

  Therefore, if it is determined in step S30 that the current value does not increase and is decreased (in the case of No), it can be determined that a magnetic force is generated from the electromagnetic coil 24 and the armature 20 and the pulley 14 are open. Therefore, the ECU 60 determines that the water pump 10 has stopped normally (step S32).

  On the other hand, if it is determined in step S30 that the current value has increased (in the case of Yes), since it cannot be determined that the armature 20 and the pulley 14 are open, the ECU 60 indicates that the water pump 10 has failed. Determination is made (step S34).

  If it is determined in step S24 that it does not belong to the water stop area (in the case of No), the water pump 10 is kept driven so that the cooling water circulates in the water gallery (step S36).

  As described above, according to the first embodiment, the failure of the water pump 10 is determined based on the change in the current value caused by the electromotive force generated by the magnetic sensor 50 when the energization state of the electromagnetic coil 24 is changed. . Since the magnetic sensor 50 generates an electromotive force based on the magnitude of the magnetic force of the magnetic circuit including the permanent magnet 22 and the electromagnetic coil 24, according to the first embodiment, water is generated based on the magnitude of the magnetic force of the magnetic circuit. The failure determination of the pump 10 is performed. For this reason, failure determination of the water pump 10 is possible including deterioration of the magnetic force of the permanent magnet 22 and the electromagnetic coil 24. Further, since the failure detection of the water pump 10 is performed based on the magnetic force, the failure detection of the water pump 10 can be performed without being influenced by the leakage of the electric circuit to which the electromagnetic coil 24 is connected.

  The magnetic sensor 50 measures not only the magnitude of the magnetic force of the magnetic circuit including the permanent magnet 22 and the electromagnetic coil 24 but also the direction of the magnetic force. For example, when the electromagnetic coil 24 as shown in FIG. 2B is energized, the magnetic circuit resists the magnetic force generated by the permanent magnet 22 and the magnetic force of the permanent magnet 22 generated by the electromagnetic coil 24. Magnetic force is generated. For example, it is assumed that the magnetic force generated by the permanent magnet 22 is larger than the magnetic force generated by the electromagnetic coil 24 when the permanent magnet 22 is not deteriorated. In this case, a magnetic force is generated in the magnetic circuit from the armature 20 side toward the pulley 14 side. Here, assuming that the permanent magnet 22 is deteriorated and the magnetic force generated by the permanent magnet 22 becomes smaller than the magnetic force generated by the electromagnetic coil 24, the magnetic circuit has a magnetic force directed from the pulley 14 side to the armature 20 side. Occurs.

  Thus, by measuring the direction of the magnetic force of the magnetic circuit including the permanent magnet 22 and the electromagnetic coil 24, it can be determined whether the permanent magnet 22 has deteriorated. The direction of the magnetic force of the magnetic circuit can be grasped by measuring the direction of the electromotive force generated by the magnetic sensor 50 as described above. That is, for example, in step S28 in FIG. 3, the direction of the magnetic force of the magnetic circuit can be grasped by measuring the direction of the current in addition to the magnitude of the current based on the electromotive force generated by the magnetic sensor 50.

  Further, as shown in step S16 and step S28 in FIG. 3, in each of the case where the energization to the electromagnetic coil 24 is stopped and the case where the electromagnet coil 24 is energized, the magnetic sensor 50 causes the magnetic circuit to Measure the size. When the energization of the electromagnetic coil 24 is stopped, only the magnetic flux from the permanent magnet 22 is input to the magnetic sensor 50. Therefore, in this case, it is possible to determine whether the permanent magnet 22 has deteriorated by comparing the current value based on the electromotive force generated by the magnetic sensor 50 with a predetermined value. For example, when the current value based on the electromotive force is lower than a predetermined value, it can be determined that the permanent magnet 22 has deteriorated.

  When the electromagnetic coil 24 is energized, magnetic flux from the permanent magnet 22 and the electromagnetic coil 24 is input to the magnetic sensor 50. In this case, if it can be confirmed that the permanent magnet 22 has not deteriorated as described above, the current value based on the electromotive force generated by the magnetic sensor 50 is compared with a predetermined value, so that the electromagnetic coil 24 It can be determined whether deterioration has occurred. For example, when the current value based on the electromotive force is larger than a predetermined value, it can be determined that the electromagnetic coil 24 has deteriorated.

  Thus, by measuring the magnitude of the magnetic force of the magnetic circuit in each case of energizing the electromagnetic coil 24 and stopping energization, and comparing the measured value with a predetermined value, It is possible to determine whether the magnet 22 has deteriorated or whether the electromagnetic coil 24 has deteriorated.

  In the first embodiment, the armature 20 is, for example, a magnetic material such as iron. However, the present invention is not limited thereto, and may be a magnet, for example. In this case, by making the direction of the magnetic force generated by the armature 20 the same as the direction of the magnetic force generated by the permanent magnet 22, the magnetic flux input to the magnetic sensor 50 when the energization to the electromagnetic coil 24 is stopped. growing. As a result, the current value based on the electromotive force generated by the magnetic sensor 50 is increased, so that it is easy to diagnose the failure of the water pump 10.

  In the first embodiment, the case where the armature 20 and the pulley 14 are engaged or the case where the armature 20 and the pulley 14 are opened using the magnetic force of the permanent magnet 22 and the magnetic force of the electromagnetic coil 24 is shown as an example. However, it is not limited to this. For example, as shown in FIG. 4, when energization to the electromagnetic coil 24 is stopped without providing the permanent magnet 22, the armature 20 and the pulley 14 are engaged by the spring force of the leaf spring 40, and the electromagnetic coil 24. When the current is supplied to the armature 20, the armature 20 and the pulley 14 may be opened by generating a magnetic force against the spring force of the leaf spring 40 from the electromagnetic coil 24.

  Thus, the armature 20 and the pulley 14 are engaged by stopping the energization of the electromagnetic coil 24, and the armature 20 and the pulley 14 are opened by energizing the electromagnetic coil 24. preferable. Thereby, even when the electromagnetic coil 24 becomes inoperable due to electric leakage or the like, the armature 20 and the pulley 14 are engaged, so that the impeller 18 rotates and the cooling water can be circulated. That is, even if the electromagnetic coil 24 becomes inoperable, the engine can be prevented from overheating. Further, when the cooling water is circulated after the engine is warmed up, the energization of the electromagnetic coil 24 is stopped, so that power consumption can be reduced and deterioration of fuel consumption can be suppressed.

  The first embodiment is also applied to the structure in which the armature 20 and the pulley 14 are engaged by energizing the electromagnetic coil 24 and the armature 20 and the pulley 14 are opened by stopping energization of the electromagnetic coil 24. Can be applied.

  FIG. 5 is a schematic diagram illustrating the water pump 10 connected to the water pump failure diagnosis apparatus 200 according to the second embodiment. As shown in FIG. 5, the water pump failure diagnosis apparatus 200 according to the second embodiment does not include the magnetic sensor 50, and the current measuring unit 68 measures the induced current generated in the electromagnetic coil 24. Moreover, the failure determination means 70 determines the failure of the water pump 10 based on the induced current generated in the electromagnetic coil 24 when the energization to the electromagnetic coil 24 is stopped. Other configurations are the same as those of the first embodiment and are shown in FIG.

  Next, a failure diagnosis process for the water pump 10 performed by the ECU 60 of the water pump failure diagnosis apparatus 200 according to the second embodiment will be described with reference to the flowcharts of FIGS. 6 and 7.

  As shown in FIG. 6, after the engine is started (step S10), the ECU 60 determines whether a predetermined time α seconds has elapsed since the engine was started (step S12).

  If it is determined in step S12 that the predetermined time α seconds has not elapsed (in the case of No), the ECU 60 applies a round to the cooling water in the water gallery to level and stabilize the electromagnetic coil 24. The energization is stopped and the water pump 10 is driven (step S14).

  Next, the ECU 60 measures the induced current generated in the electromagnetic coil 24 when the energization to the electromagnetic coil 24 is stopped (step S16). Here, the induction current is generated in the electromagnetic coil 24 for the following reason. By stopping energization of the electromagnetic coil 24, only the magnetic flux from the permanent magnet 22 is generated in the magnetic circuit including the permanent magnet 22 and the electromagnetic coil 24. The magnetic flux generated from the permanent magnet 22 is reduced by the engagement of the armature 20 and the pulley 14. Therefore, an induced current is generated in the electromagnetic coil 24 due to the change of the magnetic flux at this time.

  Next, the ECU 60 determines whether an induced current is generated in the electromagnetic coil 24 based on the measurement result in step S16 (step S18). Here, for example, when the induced current generated in the electromagnetic coil 24 is 0.5 mA to 50 mA, it can be determined that the induced current is generated in the electromagnetic coil 24. When it is determined that the induced current has been generated (in the case of Yes), since it can be determined that the armature 20 and the pulley 14 are engaged, the ECU 60 determines that the water pump 10 is normally driven. (Step S20).

  If it is determined in step S18 that no induced current is generated, the permanent magnet 22 is deteriorated because the armature 20 and the pulley 14 are not engaged although the energization of the electromagnetic coil 24 is stopped. The ECU 60 determines that the water pump 10 has failed (step S22).

  When it is determined in step S12 that the predetermined time α seconds has elapsed (in the case of Yes), the ECU 60 energizes the electromagnetic coil 24 to stop the water pump 10 (step S24). Next, the ECU 60 determines whether it belongs to a water stop region such as when the temperature of the cooling water is low or when the engine is in a light load state (step S26).

  If it is determined in step S26 that it belongs to the water stop region (in the case of Yes), the ECU 60 prevents the cooling water from circulating in the water gallery because the cooling water is in a low temperature state or the engine is in a light load state. The water pump 10 is kept stopped (step S28).

  Next, the ECU 60 measures the induced current of the electromagnetic coil 24 (step S30) and determines whether or not the induced current is generated (step S32). Here, since the water pump 10 is stopped, the change in magnetic flux due to the engagement between the armature 20 and the pulley 14 as described above should not occur. Therefore, when it is determined in step S32 that no induced current is generated (in the case of No), it is determined that the water pump 10 has stopped normally (step S34).

  If it is determined in step S30 that an induced current has occurred (in the case of Yes), the armature 20 and the pulley 14 are engaged even though the electromagnetic coil 24 is energized. 24 can be determined to have deteriorated, and the ECU 60 determines that the water pump 10 has failed (step S36).

  If it is determined in step S12 that it does not belong to the water stop region (in the case of No), the energization to the electromagnetic coil 24 is stopped and the water pump 10 is driven so that the cooling water circulates in the water gallery. (Step S38).

  Next, as in steps S16 to S22, the ECU 60 measures the induced current generated in the electromagnetic coil 24 when the energization of the electromagnetic coil 24 is stopped (step S40), and whether or not the induced current is generated. Is determined (step S42). And when it determines with the induced current having generate | occur | produced (in the case of Yes), it determines with the water pump 10 operating normally (step S44), and when it determines with the induced current not having generate | occur | produced. (In the case of No), it determines with the water pump 10 having failed (step S46).

  As described above, according to the second embodiment, when energization to the electromagnetic coil 24 is stopped, when no induced current is generated in the electromagnetic coil 24, it is determined that the water pump 10 has failed. Since the induced current of the electromagnetic coil 24 is generated by the change in the magnetic flux of the magnetic circuit, according to the second embodiment, the failure of the water pump 10 is determined based on the magnetic force of the magnetic circuit. For this reason, failure determination of the water pump 10 is possible including deterioration of the magnetic force of the permanent magnet 22 and the electromagnetic coil 24.

  Further, according to the second embodiment, unlike the first embodiment, it is not necessary to provide the magnetic sensor 50, so that it is possible to suppress an increase in the number of parts and an increase in cost.

  As shown in FIG. 8, the armature 20 can be provided with permanent magnets 42, and in particular, it is preferable to provide the permanent magnets 42 at regular intervals in the circumferential direction that is the rotation direction of the armature 20.

  As described above, by providing the permanent magnet 42 in the armature 20, whether or not slippage occurs between the pulley 14 and the armature 20 when the energization of the electromagnetic coil 24 is stopped and the water pump 10 is driven. It becomes possible to grasp. In other words, since the permanent magnet 42 rotates with respect to the electromagnetic coil 24, an induced current is generated in the electromagnetic coil 24, and slipping occurs between the pulley 14 and the armature 20 by measuring the induced current. I can understand that.

  Further, since the induced current generated in the electromagnetic coil 24 is measured as a sine waveform, the rotation speed of the armature 20 can be calculated from the wavelength of the sine waveform. Since the impeller 18 rotates together with the armature 20, the rotation speed of the armature 20 also becomes the rotation speed of the impeller 18. Since the cooling water circulates as the impeller 18 rotates, when the rotation speed of the impeller 18 changes, the cooling capacity for circulating the cooling water changes. Therefore, the failure determination of the water pump 10 can be more accurately performed by grasping the degree of increase in the temperature of the cooling water as well as the degree of sliding between the pulley 14 and the armature 20.

  In the second embodiment, as in the first embodiment, as shown in FIG. 4, the permanent magnet 22 is not provided, and the relationship between the pulley 14 and the armature 20 is generated by the magnetic force of the electromagnetic coil 24 and the spring force of the leaf spring 40. A structure that changes the combined state may be used. Further, the armature 20 and the pulley 14 may be engaged by energizing the electromagnetic coil 24, and the armature 20 and the pulley 14 may be opened by stopping energization of the electromagnetic coil 24. Even in these cases, the failure determination of the water pump 10 can be performed based on the induced current generated in the electromagnetic coil 24 when the energization state of the electromagnetic coil 24 is changed.

  Also, a method for determining a failure of the water pump 10 using the magnetic sensor 50 described in the first embodiment and a method for determining a failure of the water pump 10 based on the induced current generated in the electromagnetic coil 24 described in the second embodiment. You may combine. For example, when the energization to the electromagnetic coil 24 is stopped, the failure determination of the water pump 10 is performed based on the induced current generated in the electromagnetic coil 24, and when the electromagnetic coil 24 is energized, the magnetic sensor 50 is generated. The failure determination of the water pump 10 may be performed based on the electromotive force to be performed.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims.・ Change is possible.

DESCRIPTION OF SYMBOLS 10 Water pump 12 Belt 14 Pulley 18 Impeller 20 Armature 22 Permanent magnet 24 Electromagnetic coil 26 Hollow part 28 Through-hole 30 Housing 32 Pulley bearing 36 Shaft bearing 38 Shaft 40 Leaf spring 42 Permanent magnet 50 Magnetic sensor 62 Elapsed time judgment means 64 Water stop region determination means 66 Current control means 68 Current measurement means 70 Failure determination means 72 Relay switch 100, 200 Water pump failure diagnosis device

Claims (6)

A rotating member that rotates as the engine rotates, an electromagnetic coil that generates a magnetic force by energization, a current control unit that controls energization of the electromagnetic coil, and a magnetic force that resists the magnetic force generated by the electromagnetic coil A variable-controllable water pump failure diagnosis device comprising: a first permanent magnet; and an armature that rotates together with an impeller and changes an engagement state with the rotating member according to a magnetic force generated by the electromagnetic coil,
A water pump comprising: a failure determination unit that determines that the water pump has failed when no induced current is generated in the electromagnetic coil when energization of the electromagnetic coil is stopped by the current control unit. Fault diagnosis device.   2. The water pump failure diagnosis device according to claim 1, wherein the armature is provided with a second permanent magnet. According to the rotating member that rotates with the rotation of the engine, the electromagnetic coil that generates a magnetic force by energization, the current control means that controls the energization to the electromagnetic coil, and the magnetic force that rotates with the impeller and that the electromagnetic coil generates A variable-controllable water pump failure diagnosis device having an armature whose engagement state with the rotating member changes,
Magnetic force measuring means for measuring the magnitude of the magnetic force of the magnetic circuit including the electromagnetic coil;
On the basis of the change of the measured measurement values by the magnetic force measurement means when the energization of the electromagnetic coil is changed, have a, and failure determination means for determining a failure of the water pump by the current control means,
A third permanent magnet that generates a magnetic force that resists the magnetic force generated by the electromagnetic coil and draws the armature toward the rotating member;
The magnetic force measuring means measures the magnitude of magnetic force of a magnetic circuit including the electromagnetic coil and the third permanent magnet;
When the measured value measured by the magnetic force measuring means does not rise when the energization to the electromagnetic coil is stopped or when the measured value measured by the magnetic force measuring means rises when the electromagnetic coil is energized, A water pump failure diagnosis device characterized by determining that a failure has occurred . The magnetic force measuring means measures the direction of magnetic force of a magnetic circuit including the electromagnetic coil and the third permanent magnet,
4. The water pump failure diagnosis apparatus according to claim 3 , wherein the failure determination means determines the deterioration of the third permanent magnet based on the direction of the magnetic force measured by the magnetic force measurement means . The magnetic force measuring means measures the magnitude of the magnetic force of the magnetic circuit in each of the case where the electromagnetic coil is energized and the case where the energization of the electromagnetic coil is stopped,
The failure determination means compares the measured value measured by the magnetic force measuring means with a predetermined value in each case when the electromagnetic coil is energized and when the electromagnetic coil is de-energized. 5. The water pump failure diagnosis apparatus according to claim 3 , wherein deterioration of the electromagnetic coil or the third permanent magnet is determined . 6. The water pump failure diagnosis device according to claim 3 , wherein the armature is a magnet .

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