JP2006161853A - Hydraulic feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic feeder capable of detecting a failure of a relief valve, and thereby avoiding a malfunction due to the failure of the relief valve. <P>SOLUTION: The oil pressure feeder 1 feeds oil pressure to a transmission 12 to change gear of driving force in an internal combustion engine 10 automatically stopped when a predetermined condition is established. The oil pressure is fed into the transmission 12 during the operation of the internal combustion engine 10 by a first oil pump 42 driven by the internal combustion engine 10 via a first hydraulic circuit 41a, and during the automatic stopping of the internal combustion engine 10 by a second oil pump driven an electric motor 44 via a second hydraulic circuit 41b. When the oil pressure in the second hydraulic circuit 41b exceeds a predetermined value P3, the relief valve 49 of a relief circuit 41a is opened. The failure of the relief valve 49 is judged in response to the rotation variation of the electric motor 44 detected by a rotation variation detecting means 33. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hydraulic pressure supply device that supplies hydraulic pressure to a transmission that changes a driving force of an engine that is automatically stopped when a predetermined condition is satisfied.

  As a conventional hydraulic pressure supply device, for example, one disclosed in Patent Document 1 is known. This hydraulic pressure supply device is mounted on a vehicle and includes a main hydraulic circuit provided between an oil pan and a hydraulic operation mechanism of a transmission, and a main oil pump provided in the main hydraulic circuit. . The main oil pump is driven by the engine to operate it by supplying a first level of hydraulic pressure to the hydraulic operating mechanism.

  The hydraulic pressure supply device includes an auxiliary hydraulic circuit connected in parallel with the main hydraulic circuit. The auxiliary hydraulic circuit includes an auxiliary oil pump operated by an electric motor and a downstream side of the auxiliary oil pump. A check valve is provided. During the operation of the engine, the check valve is closed to prevent the hydraulic pressure from the main oil pump from acting on the auxiliary hydraulic circuit side. On the other hand, when the predetermined stop condition is satisfied and the engine automatically stops, the auxiliary oil pump is driven, and when the oil pressure in the main hydraulic circuit reaches a second level lower than the first level, a check is made. When the valve is opened, the hydraulic pressure from the auxiliary oil pump is supplied to the hydraulic operating mechanism.

  The hydraulic pressure supply device also includes a relief hydraulic circuit that connects between the auxiliary oil pump and the check valve of the auxiliary hydraulic circuit and the upstream side of the auxiliary oil pump. The relief hydraulic circuit includes a relief hydraulic circuit. A valve is provided. When the hydraulic pressure reaches a third level between the second level and the first level during operation of the auxiliary oil pump, the relief valve is opened and the hydraulic pressure is released to the upstream side of the auxiliary oil pump. Therefore, the hydraulic pressure supplied to the hydraulic operating mechanism during the automatic engine stop is maintained at a predetermined pressure with a small difference from the first level.

  However, this conventional hydraulic pressure supply device has the following problems. That is, in this hydraulic pressure supply device, even if a relief valve failure occurs, it cannot be detected, so there is a possibility that the auxiliary oil pump is driven in a state where the relief valve has failed. In that case, the relief action of the hydraulic pressure by the relief valve cannot be performed properly. For example, if the relief valve fails with the closed side closed, the hydraulic pressure supplied to the transmission will be excessive, and an excessive load will be applied to the auxiliary oil pump and electric motor. There is a risk. Further, when the relief valve malfunctions with the opening side open, the supply hydraulic pressure does not increase, and the required pressure to be supplied to the transmission cannot be ensured. For this reason, when the engine is started, a difference from the first level hydraulic pressure supplied to the transmission is increased, and a shock is generated when the engine is started.

  The present invention has been made to solve the above-described problems, and can provide a hydraulic pressure supply capable of detecting a failure of a relief valve and thereby avoiding a failure caused by the failure of the relief valve. The object is to provide a device.

Japanese Patent Laid-Open No. 2002-310272 (pages 2, 3 and 1, 2)

  In order to achieve this object, the invention according to claim 1 of the present invention drives the internal combustion engine (the engine 10 in the embodiment (hereinafter, the same in this section)) that is automatically stopped when a predetermined condition is satisfied. A hydraulic pressure supply device 1 that supplies hydraulic pressure to a hydraulic transmission (automatic transmission 12) that shifts a force, and is connected to the transmission in parallel with each other and supplies first and second hydraulic pressure to the transmission. Two hydraulic circuits (main hydraulic circuit 41a and auxiliary hydraulic circuit 41b) and the first hydraulic circuit are connected to the transmission during operation of the internal combustion engine, and the second hydraulic circuit is connected to the transmission during automatic stop of the internal combustion engine. A hydraulic circuit switching means (check valve 48) for switching, a first oil pump 42 which is provided in the first hydraulic circuit and is driven by the internal combustion engine to supply hydraulic pressure to the transmission, and an electric motor 44, Second hydraulic pressure A second oil pump 43 that is provided on the road and is driven by an electric motor 44 during an automatic stop of the internal combustion engine to supply hydraulic pressure to the transmission, and an upstream side of the second oil pump 43 of the second hydraulic circuit. And a relief circuit 41c for releasing the hydraulic pressure generated by the second oil pump 43, and a relief circuit 41c. The hydraulic pressure of the second hydraulic circuit is a predetermined value (third hydraulic pressure P3). ), A rotation fluctuation detection means (rotation speed sensor 33, ECU 21, steps 4 and 5 in FIG. 3) for detecting the rotation fluctuation of the electric motor 44, and a rotation fluctuation detection means. Failure determination means (ECU 21, steps 6 and 7 in FIG. 3) for determining failure of the relief valve 49 in accordance with the rotation fluctuation of the electric motor 44 detected by That.

  According to this hydraulic pressure supply device, during operation of the internal combustion engine, the first hydraulic circuit is connected to the transmission by the hydraulic circuit switching means, and the first oil pump is driven by the internal combustion engine, thereby Hydraulic pressure is supplied to the transmission via the hydraulic circuit. Further, during the automatic stop of the internal combustion engine, the second hydraulic circuit is connected to the transmission, and the second oil pump is driven by the electric motor, so that the hydraulic pressure is transmitted to the transmission via the second hydraulic circuit. Supplied. Thereby, the transmission is driven. A relief circuit is provided to connect the upstream side and the downstream side of the second oil pump of the second hydraulic circuit, and is provided in the relief circuit when the hydraulic pressure by the second oil pump exceeds a predetermined value. By opening the relief valve, the hydraulic pressure is released to the upstream side of the second oil pump, and the hydraulic pressure supplied to the transmission is kept from becoming excessive.

  As described above, the difference between the hydraulic pressure supplied from the first oil pump via the first hydraulic circuit when the operation of the engine is resumed as a result of the supply hydraulic pressure during the automatic stop of the engine being maintained at the predetermined hydraulic pressure. Can be reduced. Thereby, the transmission can be smoothly driven when the operation of the engine is resumed.

  Further, the rotation fluctuation detecting means detects the rotation fluctuation of the electric motor, and the failure determination means determines the failure of the relief valve according to the detected rotation fluctuation. If the relief valve provided as described above is normal, the hydraulic pressure is released properly, the hydraulic pressure is stabilized, and the load of the electric motor is held almost constant, so that the rotational speed is increased. On the other hand, when the relief valve breaks down, the hydraulic pressure is not stable, and the load of the electric motor fluctuates, so that the rotational speed becomes unstable. Therefore, by determining according to the rotation fluctuation of the electric motor, the failure determination of the relief valve can be appropriately performed.

  As described above, as a result of determining the failure of the relief valve, it is possible to take an appropriate measure when the failure is detected, thereby avoiding problems caused by the failure of the relief valve. For example, a situation in which a predetermined hydraulic pressure cannot be stably supplied to the transmission, an adverse effect due to an oil pressure fluctuation acting on the second hydraulic circuit, an excessive load on the electric motor, the second oil pump, etc. Furthermore, it is possible to avoid problems such as a shock due to a step difference from the hydraulic pressure supplied to the transmission when the internal combustion engine is started.

  According to a second aspect of the present invention, in the hydraulic pressure supply device 1 according to the first aspect, when the failure determination means determines that the relief valve 49 has failed, the drive of the electric motor 44 is stopped and the internal combustion engine is stopped. By driving the first oil pump 42, hydraulic pressure is supplied to the transmission.

  According to this hydraulic pressure supply device, when it is determined by the failure determination means that the relief valve has failed, the drive of the electric motor is stopped, and the first oil pump is driven by the internal combustion engine, whereby the hydraulic pressure is reduced to the first level. It is supplied to the transmission via a hydraulic circuit. As a result, the supply of hydraulic pressure via the second hydraulic circuit is stopped, so that the hydraulic pressure necessary for the operation of the transmission can be secured and the occurrence of problems due to the failure of the relief valve can be reliably avoided. can do.

  According to a third aspect of the present invention, in the hydraulic pressure supply device 1 according to the second aspect, the failure determination means determines whether the relief valve 49 has failed, the first hydraulic circuit is connected to the transmission, and the electric motor 44 is driven. It is characterized by being executed in a state where

  According to this hydraulic pressure determination device, when the electric motor is driven in a state where the first hydraulic circuit is connected to the transmission, the hydraulic pressure in the second hydraulic circuit increases, and when the predetermined value is reached, the relief valve is The valve is opened and hydraulic pressure is released by the relief circuit. In such a state, the failure determination of the relief valve by the failure determination means is executed. If it is determined that the relief valve is malfunctioning, the drive of the electric motor is stopped and the hydraulic pressure is supplied via the first hydraulic circuit by the internal combustion engine.

  As described above, since the failure determination is performed in a state where the first hydraulic circuit is connected to the transmission and the second hydraulic circuit is shut off, the second hydraulic circuit is in a state where the relief valve has failed during the failure determination. It is possible to reliably avoid the situation of supplying hydraulic pressure via the. Therefore, it is possible to reliably avoid the trouble caused by the failure of the relief valve from reaching the transmission, the first oil pump, and the like. In addition, when a failure of the relief valve is detected, the supply of hydraulic pressure by the first oil pump is maintained, so that a decrease in hydraulic pressure due to the failure of the relief valve can be avoided, for example, the occurrence of a shock due to a decrease in hydraulic pressure is avoided. The smooth operation of the transmission can be ensured.

  Hereinafter, a hydraulic pressure supply device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 schematically shows a hydraulic pressure supply device 1 to which the present invention is applied together with a drive system of a vehicle. The vehicle has an internal combustion engine (hereinafter referred to as “engine”) 10 and a motor 11 as drive sources, and the motor 11 assists the engine drive mode in which the vehicle is driven only by the engine 10 or the driving force of the engine 10. It is driven by a motor assist mode for driving the vehicle. The engine 10 is automatically stopped (hereinafter referred to as “idle stop”) under the control of the ECU 21 when an idle stop condition described later is satisfied.

  The motor 11 is directly connected to the crankshaft 10a of the engine 10 and is connected to driving wheels 13 of the vehicle via a hydraulic automatic transmission 12 (transmission) or the like. The motor 11 is connected to a battery 14 as a driving source via a power drive unit (hereinafter referred to as “PDU”) 20. The PDU 20 is composed of an electric circuit including an inverter. Furthermore, the motor 11 has a function as a generator that generates electric power using the rotational energy of the drive wheels 13, and the generated electric energy is charged (regenerated) to the battery 14 via the PDU 20. The motor 11 is connected to the ECU 21 via the PDU 20. A first oil pump 42 of the hydraulic pressure supply device 1 described below is provided between the motor 11 and the automatic transmission 12.

  The automatic transmission 12 has a torque converter (not shown) with a lock-up clutch, and the hydraulic pressure supply device 1 is connected to the automatic transmission 12. Under the control of the ECU 21, the hydraulic pressure is supplied from the hydraulic pressure supply device 1 to control the shift operation of the automatic transmission 12 and the engagement / disengagement of the lockup clutch. As shown in FIG. 2, the hydraulic pressure supply device 1 includes a hydraulic circuit 41, a first oil pump 42, a second oil pump 43, an electric motor 44, and an oil pan 45 that stores hydraulic oil. The hydraulic circuit 41 includes a main hydraulic circuit 41a (first hydraulic circuit), an auxiliary hydraulic circuit 41b (second hydraulic circuit), and a relief circuit 41c.

  One end of the main hydraulic circuit 41a is connected to a strainer 45a provided in the oil pan 45, and the other end is connected to the automatic transmission 12, and the first oil pump 42 is disposed in the middle. . The first oil pump 42 is operated by the driving force of the engine 10 during the engine driving mode, and is operated by the driving force of the engine 10 and the motor 11 during the motor assist mode, so that the automatic transmission 12 has a predetermined first hydraulic pressure. P1 (for example, 9.0 MPa) is supplied.

  The auxiliary hydraulic circuit 41b is provided in parallel with the main hydraulic circuit 41a so as to connect the upstream side and the downstream side of the first oil pump 22 of the main hydraulic circuit 41a. The second oil pump 43 is disposed in the middle of the auxiliary hydraulic circuit 41b and is connected to an electric motor 44 as a drive source. The second oil pump 43 is basically driven when the first oil pump 42 cannot be driven by stopping the engine 10 and the motor 11, for example, during idling stop of the engine 10 described later.

  The electric motor 44 is, for example, a three-phase brushless DC motor and is a sensorless type that does not have a sensor for detecting the position of the rotor, and is connected to a battery 46 that is a driving source via a control device 47. Connected (see FIG. 1). The battery 46 is a 12V DC battery. Further, the electric motor 44 is controlled by the ECU 21 via the control device 47 to drive the second oil pump 43 with a predetermined constant driving force, whereby the automatic transmission 12 is driven from the second oil pump 43. Is supplied with hydraulic pressure. The electric motor 44 is provided with a rotation speed sensor 33 (rotation fluctuation detecting means) for detecting the rotation speed N, and the detection signal is output to the ECU 21 described later.

  Further, a check valve 48 (hydraulic circuit switching means) is provided on the downstream side of the second oil pump 43 in the auxiliary hydraulic circuit 41b. The check valve 48 prevents hydraulic fluid from flowing from the downstream side to the upstream side, that is, transmission of hydraulic pressure.

  The relief circuit 41c is provided so as to connect between the second oil pump 43 and the check valve 48 of the auxiliary hydraulic circuit 41b and the upstream side of the second oil pump 43. A valve 49 is provided. The relief valve 49 is for releasing the hydraulic pressure from the second oil pump 43 to the upstream side, and opens when the hydraulic pressure exceeds a predetermined third hydraulic pressure P3 (for example, 3.0 MPa) (predetermined value). The valve is configured to close when it falls below the third hydraulic pressure P3.

  In the present embodiment, the ECU 21 constitutes a rotation fluctuation detection means and a failure determination means, and is constituted by a microcomputer (all not shown) including a RAM, a ROM, a CPU, an I / O interface, and the like. The operation of the engine 10 and the motor 11 is controlled. In addition, detection signals representing the vehicle speed VP and the accelerator opening AP are output from the vehicle speed sensor 30 and the accelerator opening sensor 31 to the ECU 21, respectively. The accelerator opening AP represents an operation amount of an accelerator pedal (not shown). Further, a brake switch 32 is connected to the ECU 21. The brake switch 32 outputs an ON signal to the ECU 21 when a brake pedal (not shown) is depressed by a predetermined amount or more, and an OFF signal otherwise. In accordance with these input signals, the CPU executes a failure determination process for the relief valve 49 as described below in accordance with a control program stored in the ROM.

  Before explaining the failure determination process, the operations of the engine 10 and the electric motor 44 at the time of idling stop, which is the premise thereof, will be described. When a predetermined condition for idling stop is satisfied, the operation of the electric motor 44 is started (timing t1 in FIG. 5). With the operation of the electric motor 44, the second oil pump 43 is driven, and as shown by the solid line in FIG. 5, the hydraulic pressure Pa (hereinafter simply referred to as the upstream side) of the check valve 48 of the auxiliary hydraulic circuit 41b. “Hydraulic pressure Pa”) rises rapidly. Thereafter, when the hydraulic pressure Pa exceeds the third hydraulic pressure P3, the relief valve 49 is opened, whereby the hydraulic pressure is released to the upstream side of the second oil pump 43, and the hydraulic pressure Pa is higher than the third hydraulic pressure P3. Slightly higher second hydraulic pressure P2 (for example, 3.5 MPa) is maintained.

  On the other hand, the engine 10 is automatically stopped when a predetermined time has elapsed from the start of the operation of the electric motor 44 (timing t2). Accordingly, the first oil pump 42 is stopped when the engine 10 enters an idle stop state. Accordingly, as shown in FIG. 4, the pump pressure Pm of the first oil pump 42 starts to decrease and finally becomes zero. As a result, the check valve 48 is opened to connect the auxiliary hydraulic circuit 41b to the automatic transmission 12 (timing t3), and the hydraulic pressure is supplied to the automatic transmission 12 by the second oil pump 43. Further, as shown in FIG. 5, in the state after the auxiliary hydraulic circuit 41b is connected, the relief valve 49 is opened, so that the hydraulic pressure Pa is slightly smaller than the second hydraulic pressure P2. Maintained in the vicinity.

  FIG. 3 is a flowchart showing a failure determination process for the relief valve 49. This process is to determine the failure of the relief valve 49 according to the rotational fluctuation of the electric motor 44 during the idling stop, and is executed at a predetermined cycle.

  First, in step 1 (illustrated as “S1”, the same applies hereinafter), it is determined whether or not the idle stop condition flag F_IDLSTP and the current value stability flag F_MOTCON are both “1”. The idle stop condition flag F_IDLSTP is set to “1” when a predetermined condition for executing idle stop is satisfied, and set to “0” otherwise. This predetermined condition is that the vehicle speed VP is equal to or less than a predetermined value, the accelerator opening AP is 0, and an ON signal is output from the brake switch 32.

  The current value stabilization flag F_MOTCON is set to “1” when the current supplied from the control device 47 to the electric motor 44 is in a stable and almost constant state, and is set to “0” otherwise. is there. That is, the current value stability flag F_MOTCON indicates whether or not the electric motor 44 is stably operated with a constant torque.

  When the determination result of step 1 is NO, that is, when the condition for executing the idling stop is not satisfied, or when the torque of the electric motor 44 is not stable, a check valve opening / closing counter TDNCHECK and a rotation fluctuation counter described later The count values of CTN are reset to “0” (steps 9 and 10), and this process is terminated.

  On the other hand, when the determination result of step 1 is YES, that is, when the execution condition for idling stop is satisfied and the electric motor 16 operates stably, and its torque is kept constant, the check valve The open / close counter TDNCHECK is incremented (step 2).

  Next, it is determined whether or not the check valve opening / closing counter TDNCHECK is equal to or greater than a predetermined value TREF (step 3). This predetermined value TREF corresponds to the time (t3-t1) during which the hydraulic pressure Pa is maintained at the second hydraulic pressure P2 from when the electric motor 44 is started until the check valve 48 is opened. .

When the determination result in step 3 is NO, that is, when the predetermined time corresponding to the predetermined value TREF has not elapsed after the electric motor 44 is started, the routine proceeds to step 4 where the rotational speed deviation | ΔN | calculate. The rotational speed deviation | ΔN | is an absolute value obtained by subtracting the previous value N _n-1 from the current value N _n of the rotational speed N of the electric motor 44.

  Next, it is determined whether or not the rotational speed deviation | ΔN | calculated in step 4 is larger than a predetermined determination value NLON (for example, 500 rpm) (step 5). When the determination result is NO, that is, when the rotational fluctuation of the electric motor 44 between the previous time and the current time is small, the present process is ended as it is. On the other hand, when the determination result is YES and the rotation fluctuation of the electric motor 44 is large, the process proceeds to step 6 to increment the rotation fluctuation counter CTN.

  Next, the routine proceeds to step 7, where it is determined whether or not the count value of the rotation fluctuation counter CTN is greater than or equal to a predetermined determination value CREF. If the determination result is NO and the count value of the rotation fluctuation counter CTN has not yet reached the predetermined value CREF, the present process is terminated. On the other hand, when the determination result is YES, that is, when the number of times that the rotational speed deviation | ΔN | exceeds the determination value NLON has reached the determination value CREF or more, it is determined that the relief valve 49 has failed, In order to express this, the relief valve failure flag F_RELIEFNG is set to “1” (step 8), and this processing is terminated.

  On the other hand, when the determination result in step 3 is YES, that is, when a predetermined time corresponding to the predetermined value TREF has already elapsed after the electric motor 44 is started, the step 10 is executed, and this process is terminated.

  As described above, when the relief valve 49 is normal, as shown by a solid line in FIG. 5, the hydraulic pressure Pa is maintained after the start of the electric motor 44 until the check valve 48 is opened (t1 to t3). ), Stably maintained in the vicinity of the second hydraulic pressure P2. For this reason, since the load acting on the second oil pump 43 is kept constant, the rotational fluctuation of the electric motor 44 driven with a substantially constant torque is very small. On the other hand, when the relief valve 49 is out of order, the oil pressure is not released properly, so that, for example, the oil pressure Pa greatly fluctuates with time as shown by a broken line in FIG. For this reason, as the hydraulic pressure varies, the load acting on the electric motor 44 via the second oil pump 43 varies. As a result, the rotational speed N also varies greatly. Therefore, as described above, the failure of the relief valve 49 can be appropriately determined by executing the determination in step 7 according to the rotational fluctuation of the electric motor 44.

  When the relief valve failure flag F_RELIENG is set to “1” in step 8, the electric motor 44 is stopped and the engine 10 is started. Accordingly, the supply of hydraulic pressure from the first oil pump 42 via the main hydraulic circuit 41a is resumed, so that the hydraulic pressure is supplied via the main hydraulic circuit 41a without being connected to the auxiliary hydraulic circuit 41b.

  As described above, when the electric motor 44 is driven while the engine 10 is idling, the failure of the relief valve 49 can be appropriately determined according to the rotational fluctuation of the electric motor 44.

  When it is determined that the relief valve 49 has failed, the electric motor 44 is stopped and the engine 10 is restarted to stop the supply of hydraulic pressure from the auxiliary hydraulic circuit 41b. 1 Oil pressure is supplied by the oil pump 42 via the main hydraulic circuit 41a. Therefore, the hydraulic pressure necessary for the operation of the automatic transmission 12 can be ensured, and the occurrence of problems due to the failure of the relief valve 49 can be reliably avoided. For example, a situation in which the required hydraulic pressure cannot be stably supplied to the automatic transmission 12, a hydraulic pressure fluctuation acts on the auxiliary hydraulic circuit 41b, or an excessive load is applied to the electric motor 44, the second oil pump 43, or the like. It is possible to avoid problems such as the occurrence of a shock due to a step difference from the first hydraulic pressure P1 supplied to the automatic transmission 12 when the engine 10 is restarted.

  In addition, since the failure determination of the relief valve 49 is executed in a state where the auxiliary hydraulic circuit 41b is shut off by the check valve 48, the relief valve 49 is broken through the auxiliary hydraulic circuit 41b during the failure determination. The situation of supplying hydraulic pressure can be avoided reliably.

  In addition, this invention can be implemented in various aspects, without being limited to the said embodiment described. For example, in the embodiment, the failure determination of the relief valve 49 is performed during the execution of the idle stop, but the present invention is not limited to this, and the check valve 48 is maintained in the closed state. That's fine. Further, in the embodiment, mechanical type valves are used as the check valve 48 and the relief valve 49, but other types of valves, for example, an electromagnetic valve controlled by the ECU 21 may be used instead. .

  Furthermore, the present invention is not limited to vehicles, and can of course be applied to various industrial machines such as a ship including a ship propulsion engine such as an outboard motor in which a crankshaft is arranged in a vertical direction. In addition, it is possible to appropriately change the detailed configuration within the scope of the gist of the present invention.

1 is a schematic configuration diagram of a vehicle to which a hydraulic pressure supply device according to an embodiment of the present invention is applied. It is a figure which shows the hydraulic pressure supply apparatus of FIG. It is an example of the flowchart of a relief valve failure determination process. It is a figure which shows the change of the pump pressure of a 1st oil pump when engine idling stop is performed with time. It is a figure which shows the change of the oil_pressure | hydraulic in an auxiliary hydraulic circuit when an engine idling stop is performed with time.

Explanation of symbols

1 Hydraulic supply device 10 Engine (internal combustion engine)
12 Automatic transmission (transmission)
21 ECU (rotation fluctuation detecting means, failure judging means)
33 Rotational speed sensor (rotational fluctuation detecting means)
41a Main hydraulic circuit (first hydraulic circuit)
41b Auxiliary hydraulic circuit (second hydraulic circuit)
41c Relief circuit 42 First oil pump 43 Second oil pump 44 Electric motor 48 Check valve (hydraulic circuit switching means)
49 Relief valve P3 Third hydraulic pressure (predetermined value)

Claims (3)

A hydraulic pressure supply device that supplies hydraulic pressure to a hydraulic transmission that shifts a driving force of an internal combustion engine that is automatically stopped when a predetermined condition is satisfied,
A first hydraulic circuit and a second hydraulic circuit connected to the transmission in parallel and for supplying hydraulic pressure to the transmission;
Hydraulic circuit switching means for switching the first hydraulic circuit to the transmission during operation of the internal combustion engine and for switching to connect the second hydraulic circuit to the transmission during automatic stop of the internal combustion engine;
A first oil pump which is provided in the first hydraulic circuit and supplies hydraulic pressure to the transmission by being driven by the internal combustion engine;
An electric motor;
A second oil pump that is provided in the second hydraulic circuit and supplies hydraulic pressure to the transmission by being driven by the electric motor during automatic stop of the internal combustion engine;
A relief circuit provided to connect the upstream side and the downstream side of the second oil pump of the second hydraulic circuit, and for releasing the hydraulic pressure generated by the second oil pump;
A relief valve provided in the relief circuit and opened when the hydraulic pressure of the second hydraulic circuit exceeds a predetermined value;
Rotation fluctuation detecting means for detecting rotation fluctuation of the electric motor;
Failure determination means for determining failure of the relief valve according to the rotation fluctuation of the electric motor detected by the rotation fluctuation detection means;
A hydraulic pressure supply device comprising:   When it is determined by the failure determination means that the relief valve has failed, the drive of the electric motor is stopped, and the first oil pump is driven by the internal combustion engine, whereby hydraulic pressure is applied to the transmission. The hydraulic pressure supply device according to claim 1, wherein the hydraulic pressure supply device is supplied.   The determination of the failure of the relief valve by the failure determination means is executed in a state where the first hydraulic circuit is connected to the transmission and the electric motor is driven. Hydraulic supply device.

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