JP2009133332A - Failure determination device for electric oil pump for re-start response improvement used for transmission of idle-stop vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device determining the failure of an electric oil pump for re-start response improvement after an idle stop without additionally installing a hydraulic sensor while a vehicle is stopped before an idle stop. <P>SOLUTION: While the vehicle is stopped before idle stop, the electric oil pump 8 is test-driven for determining a failure. The hydraulic pressure of the pump acts on the pressure receiving surface B of a spool 11 in a hydraulic chamber 15, and lowers the spool from the position of a chain double-dashed line. Since a shift control pressure Pc acting on the pressure receiving surface A of the spool 11 is low as the vehicle is stopped, the lowering of the spool 11 is allowed. A stroke valve 10 thereby allows the downstream side oil passage portion 6b of a shift control pressure oil passage 6 to communicate with a drain port 13, and lowers the movable flange pressing hydraulic oil (shift control pressure Pc) of a secondary pulley 1. The hydraulic pressure drop is detected because of the lowering of the hydraulic pressure value detected by the hydraulic sensor 7 indispensable for shift control, and whether the pump 8 is normal or failed is determined by the presence or absence of the lowering of the detected value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is capable of traveling through a transmission with power from a prime mover. During operation of the prime mover, the transmission is controlled by hydraulic pressure from a prime mover drive oil pump driven by the prime mover, and is predetermined when the vehicle is stopped. An idle stop that automatically stops the prime mover when the conditions are met, and improves the restart response by making the transmission ready to transmit power by hydraulic pressure from the electric oil pump instead of the prime mover drive oil pump. The present invention relates to a vehicle with a stop, and in particular, to a failure determination technique of the electric oil pump for improving the restart response.

As a technique to improve the fuel efficiency of the vehicle, there is an idle stop technology that automatically stops the prime mover such as an engine when a predetermined condition such as a stop state without a willingness to start at the time of stopping has reached a set time,
This idle stop technology is used when the driver performs an operation that seems to be intended to start, such as releasing the brake pedal and changing the brake from the active state to the inactive state. Is automatically started.

By the way, during the idling stop, since the prime mover such as the engine is not operated, there is no hydraulic pressure from the prime mover drive oil pump driven thereby, and the transmission is in a state where power transmission is impossible.
When the prime mover such as the engine is started by releasing the idle stop from this state, the hydraulic pressure from the prime mover drive oil pump driven thereby is generated and the transmission can be transmitted to the power transmission state. There is a delay in response until the drive oil pump generates hydraulic pressure and the transmission is ready to transmit power, which not only worsens the vehicle's restart response, but also causes a restart shock due to the engine's idling. This causes the problem.

  Therefore, conventionally, as described in Patent Document 1, for example, a technique has been proposed in which the transmission is kept in a state capable of transmitting power by hydraulic pressure from an electric oil pump instead of a prime mover driven oil pump during idle stop.

  According to this technology, since the transmission is kept in a state where power can be transmitted by the hydraulic pressure from the electric oil pump even during the idle stop, the hydraulic pressure from the prime mover driven oil pump is immediately after the prime mover is started by releasing the idle stop. Can take over the power transmission possible state of the transmission, and the transmission can transmit power immediately after starting the prime mover to improve the vehicle's re-start response and avoid re-start shock.

By the way, the electric oil pump cannot generate pump oil pressure due to its own failure or power system and control system failure, or the pump oil pressure cannot be raised as prescribed.
Since the transmission cannot be brought into a state where power can be transmitted and the original purpose of improving the restart response cannot be achieved, a large restart shock is caused. Should be prohibited.

In Patent Document 1, in prohibiting the idle stop at the time of failure of the electric oil pump, the failure determination of the electric oil pump is performed once the idle stop is executed, and if the failure occurs, the prime mover is restarted.
In the sense of avoiding useless temporary idle stop at the time of failure of the electric oil pump, preferably the failure determination of the electric oil pump is performed before executing the idle stop, and if the failure occurs, the prime mover is operated without executing the idle stop. It is better to take countermeasures for failure.
JP 2006-152868 A

In order to determine the failure of the electric oil pump before executing the idle stop in view of the above requirements,
An oil pressure sensor that directly detects the oil pressure of the electric oil pump is added, and the electric oil pump is test-driven before the idle stop is executed. Depending on whether the detected oil pressure value of the oil pressure sensor at this time is a specified value or not It is common sense to determine whether the electric oil pump is normal or malfunctioning.

  However, the addition of a hydraulic sensor that directly detects the hydraulic pressure of the electric oil pump is problematic because of the increase in cost due to the addition of the hydraulic sensor. In addition, if a hydraulic sensor is further added, the problem that the reliability of the operation is lowered cannot be ignored.

In view of the above requirements, as another method for enabling failure determination of the electric oil pump before execution of idle stop,
An electric sensor for detecting the drive current and drive power of the electric oil pump is provided, and the electric oil pump is driven by a test drive before executing the idle stop. Whether or not the electric detection value of the sensor at this time is specified There is also a method for determining whether the electric oil pump is normal or malfunctioning.

However, since the drive current and drive power of the electric oil pump are large, an electrical sensor for detecting these is also effective, and the same cost problem as in the case of adding a hydraulic sensor cannot be avoided.
Moreover, in the failure determination by such an electric sensor, it is not possible to make a critical failure determination as to whether or not the hydraulic pressure from the electric oil pump is as specified, and the drive current and drive power of the electric oil pump are as specified. Even if it is judged as normal, there is no guarantee that the hydraulic pressure from the electric oil pump is as specified, and it is possible to accurately determine the failure of the electric oil pump hydraulic pressure, which is the most important judgment target. Can not.

  According to the present invention, a hydraulic pressure sensor for shifting control already exists in the shift control pressure circuit, and a failure determination of the electric oil pump can be performed using the detected hydraulic pressure value directly or indirectly. An object of the present invention is to solve the above-mentioned problems.

For this purpose, the failure determination device for a rebound response improving electric oil pump used in a transmission of a vehicle with an idle stop according to the present invention is configured as described in claim 1.
First, to explain a vehicle with an idle stop which is a premise of the present invention,
The motor can travel through the transmission with the power from the prime mover, and during the operation of the prime mover, the transmission is controlled by the hydraulic pressure from the prime mover driven oil pump driven by the prime mover, and predetermined conditions are met when the vehicle is stopped. An idle stop is automatically performed to stop the prime mover at the same time, and instead of the prime mover drive oil pump, the transmission is made in a state where power can be transmitted by hydraulic pressure from an electric oil pump to improve a restart response. is there.

The failure determination device of the electric oil pump for recurrent response improvement according to the present invention is a vehicle with such an idle stop,
Electric oil pump test drive means for driving the electric oil pump during operation of the prime mover;
Pressure reducing valve means for reducing the shift control pressure for the shift control in response to the hydraulic pressure from the electric oil pump that is test-driven by the means;
If the reduction of the shift control pressure is not as specified, an electric oil pump failure determination means for determining that the electric oil pump has failed is provided.

In the failure determination device for the electric oil pump for improving the restart response of the present invention,
If the electric oil pump is test driven during the operation of the prime mover (before idling stop), and if the hydraulic pressure from the electric oil pump is generated as specified during this period, the pressure reducing valve means will shift in response to this electric oil pump hydraulic pressure. Reduce the control pressure as specified.
The electric oil pump failure determination means determines that the electric oil pump is in failure if the shift control pressure does not decrease as specified.

Such a failure determination of the electric oil pump does not require any oil pressure sensor for detecting the electric oil pump oil pressure, and directly or indirectly uses the oil pressure detection value from the existing oil pressure sensor indispensable for the speed change control in the speed change control pressure circuit. Therefore, it is possible to determine the failure of the electric oil pump.
Therefore, in view of the above requirements, even though the failure determination of the electric oil pump can be performed before the execution of the idle stop,
Without adding a hydraulic sensor that directly detects the hydraulic pressure of the electric oil pump, the failure determination can be performed using the hydraulic pressure detection value from the existing hydraulic sensor in the shift control pressure circuit,
It is possible to solve the problem of cost increase due to the addition of the hydraulic sensor and the problem of the decrease in reliability.

  Moreover, although the electric oil pump actually detects the failure of the electric oil pump by providing an electric sensor that detects the driving current and electric power of the electric oil pump, the actual oil pressure from the electric oil pump is not as specified. In addition, it is possible to avoid the adverse effect of making a false determination that it is normal.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
FIG. 1 shows an embodiment of a failure determination device for an electric oil pump for improving restart response, which is configured to be used for a vehicle with an idle stop equipped with a V-belt type continuously variable transmission.

1 is a secondary pulley of a V-belt type continuously variable transmission, 2 is a V belt hung on the secondary pulley 1,
The V-belt 2 is stretched between the secondary pulley 1 and a primary pulley (not shown) aligned with the secondary pulley 1 to constitute a transmission unit of the V-belt continuously variable transmission.
Rotation from a prime mover such as an engine is input to a primary pulley (not shown), and the rotation of the primary pulley is transmitted to the secondary pulley 1 via the V-belt 2 and used for traveling of the vehicle.

  In this transmission, the V-belt type continuously variable transmission has one V-groove flange (the left movable flange in FIG. 1) of the opposing flanges forming the V-groove of the secondary pulley 1 approaching the other fixed flange, or At the same time as making the V groove width smaller or larger by separating them, the V groove flange (movable flange) on the right side of the primary pulley in FIG. 1 is separated from or brought closer to the V groove flange (fixed flange) on the opposite side. It is assumed that continuously variable transmission is performed by continuously changing the winding arc diameter of the V belt 2 with respect to the primary pulley and the secondary pulley 1 by increasing or decreasing.

The speed change control of the V-belt type continuously variable transmission is executed by adjusting the movable flange pressing hydraulic pressure of the secondary pulley 1;
In this speed change control, the speed change control circuit 4 (electronic control unit and hydraulic pressure control unit) uses the hydraulic oil from the prime mover drive oil pump 3 driven by a prime mover such as an engine coupled to the primary pulley as a medium. Shall be performed as follows.

That is, the driving state detection means 5 detects the engine throttle opening TVO and the vehicle speed VSP representing the driving state of the vehicle, and the shift control circuit 4 is suitable for the current driving state from the planned shift map based on these driving information. The target input speed (target gear ratio) is obtained.
The transmission control circuit 4 generates the hydraulic oil from the prime mover drive oil pump 3 as a transmission control pressure Pc that achieves the target input rotational speed (target transmission ratio), and this transmission control pressure Pc is used as the transmission control pressure oil. Supplying from the path 6 to the secondary pulley 1 as a hydraulic pressure for pressing the movable flange of the secondary pulley 1, the V-belt continuously variable transmission has an input rotational speed (speed ratio) that matches the target input rotational speed (target speed ratio). Shift control is performed.

By the way, the shift control pressure Pc is deviated from the hydraulic pressure necessary to achieve the target input rotation speed (target shift ratio) due to disturbances and the like, and there is a risk of hindering accurate shift control. Therefore, it is usual to add the following feedback control system.
That is, a hydraulic pressure sensor 7 that detects the movable flange pressing hydraulic pressure of the secondary pulley 1 is provided, and the movable flange pressing hydraulic pressure detected by the hydraulic sensor 7 is fed back to the shift control circuit 4.

The shift control circuit 4 determines how far the feedback of the movable flange pressing hydraulic pressure of the secondary pulley 1 from the command value of the shift control pressure Pc necessary to achieve the target input rotational speed (target gear ratio). Calculate and change the command value of the shift control pressure Pc so that this divergence is resolved,
This ensures that the shift control pressure Pc does not deviate from the hydraulic pressure required to achieve the target input speed (target gear ratio), even when disturbances are received, and accurate shift control is continuously performed. To be able to.

In this embodiment, the prime mover such as the engine coupled to the primary pulley is equipped with an idle stop for improving fuel efficiency, and when a predetermined condition is met such that a stop state without a willingness to start at the time of a stop has passed for a set time, A prime mover such as an engine shall be automatically stopped.
To release the idle stop, the engine or other prime mover is automatically started when the driver performs an operation that seems to be intended to start, such as releasing the brake pedal and changing the brake from the active state to the inactive state. The cancellation shall be made.

By the way, during the idling stop, since the prime mover such as the engine is not operated, the transmission control circuit 4 cannot produce the transmission control pressure Pc without the hydraulic pressure from the prime mover drive oil pump 3 driven thereby.
Therefore, the V-belt 2 cannot be clamped between the movable flange and the fixed flange of the secondary pulley 1, and the V-belt continuously variable transmission is in a state where power cannot be transmitted.

  When the prime mover such as the engine is started by releasing the idle stop from this state, the hydraulic pressure from the prime mover drive oil pump 3 driven thereby is generated to make the V-belt continuously variable transmission ready for power transmission. In addition, there is a response delay until the prime mover drive oil pump 3 generates hydraulic pressure by starting the prime mover and makes the V-belt type continuously variable transmission ready for power transmission, which not only worsens the vehicle's restart response. Triggering a re-start shock when the prime mover blows.

Therefore, in this embodiment, the V-belt continuously variable transmission is kept in a power transmission enabled state by the hydraulic pressure from the electric oil pump 8 instead of the prime mover drive oil pump 3 during the idle stop.
For this reason, the discharge port of the electric oil pump 8 is communicated with the secondary pulley connecting portion of the transmission control pressure oil passage 6 through the oil passage 9.
According to such a configuration, the V-belt 2 can be clamped between the movable flange and the fixed flange of the secondary pulley 1 by the hydraulic pressure from the electric oil pump 8 even during idle stop, and the V-belt continuously variable transmission can be powered. It can be kept in a transmittable state.

  Accordingly, as soon as the engine (prime mover) is started by releasing the idle stop, the hydraulic pressure from the prime mover drive oil pump 3 can take over the state in which the transmission can transmit power, and the V belt immediately after the engine (prime mover) starts. The continuously variable transmission can perform power transmission to improve the vehicle's re-start response and avoid a re-start shock.

By the way, the electric oil pump 8 can not generate pump oil pressure due to its own failure or power system and control system failure, or it cannot increase the pump oil pressure as prescribed.
The V-belt continuously variable transmission cannot be made in a state where power can be transmitted, and not only the original purpose of improving the restart response cannot be achieved, but also a large restart shock is caused. .

  When prohibiting the idle stop when the electric oil pump 8 fails, the failure determination of the electric oil pump 8 is performed before the idle stop is executed in the sense of avoiding the foolishness that the temporary idle stop is wasted. In the case of a failure, it is preferable to take a countermeasure against the failure in which the engine (prime motor) is kept running without executing the idle stop.

In the present embodiment, in view of the above request, the failure determination of the electric oil pump 8 is performed before the idle stop is executed.
The main purpose is to propose a configuration in which a failure determination of the electric oil pump 8 can be made before execution of idle stop without adding a hydraulic pressure sensor that directly detects the hydraulic pressure of the electric oil pump 8.

In view of this gist, in this embodiment, the shift control pressure oil passage 6 is divided between the upstream oil passage portion 6a and the downstream oil passage portion 6b, and the upstream oil passage portion 6a and the downstream oil passage portion. A stroke valve 10 which is a pressure reducing valve means is inserted in the shift control pressure oil passage 6 between 6b.
The stroke valve 10 is provided with a spool 11 elastically supported by a spring 12 at a normal position shown in FIG. 1, and at the normal position of the spool 11, an upstream oil passage portion 6a and a downstream oil passage portion of the speed change pressure oil passage 6 are provided. It is assumed that the portion 6b communicates and the drain port 13 is closed.

The stroke valve 10 further has a hydraulic chamber 14 defined by slidingly fitting a small diameter end portion of the spool 11 on which the spring 12 acts on the valve housing, and also controls the large diameter land on the opposite side of the spool 11. A hydraulic chamber 15 is defined that is slidably fitted into the housing.
Here, the stroke valve 10 will be described in detail later, and the sum of the force generated by the hydraulic pressure in the hydraulic chamber 14 acting on the pressure receiving surface A of the spool 11 and the spring force of the spring 12, and the hydraulic pressure in the hydraulic chamber 15 The stroke position of the spool 11 is determined by the correlation with the force generated by acting on the pressure receiving surface B of the spool 11.

When the spool 11 is in the normal position shown in FIGS. 1 and 2, the stroke valve 10 communicates between the upstream oil passage portion 6a and the downstream oil passage portion 6b of the transmission control pressure oil passage 6 and closes the drain port 13.
When the spool 11 is at the opposite limit position as shown in FIG. 3, the stroke valve 10 closes the downstream oil passage portion 6b of the transmission control pressure oil passage 6, and connects the upstream oil passage portion 6a to the drain port 13. ,
When the spool 11 is in the pressure reducing position shown by the solid line in FIG. 4, the stroke valve 10 does not limit the opening of the upstream oil passage portion 6a of the transmission control pressure oil passage 6, and between the downstream oil passage portion 6b and the drain port 13. It is assumed that the hydraulic pressure for pressing the movable flange of the secondary pulley 1 is reduced by adjusting the degree of communication.

An orifice 16 is inserted into the upstream oil passage portion 6 a of the transmission control pressure oil passage 6, and the upstream oil passage portion 6 a is connected to the hydraulic chamber 14 via the communication oil passage 17 on the upstream side of the orifice 16.
The end of the electric oil pump pressure oil passage 9 far from the electric oil pump 8 is connected to the downstream oil passage portion 6b of the transmission control pressure oil passage 6, and a check valve is connected to the electric oil pump pressure oil passage 9 in the vicinity of this connection portion. 18 is inserted, and the oil passage 9 is connected between the check valve 18 and the electric oil pump 8 to the hydraulic chamber 15 through the communication oil passage 19.
The check valve 18 allows oil discharged from the electric oil pump 8 to flow therethrough, but is arranged in a direction to prevent reverse oil flow.

The operation of the above embodiment will be described below with reference to FIGS.
While the engine (prime mover) is in operation and the electric oil pump 8 is not operated, the shift control circuit 4 (see FIG. 1) uses the hydraulic oil from the prime mover drive oil pump 3 (see FIG. 1) as a medium to control the shift control pressure. Although Pc is output, no hydraulic pressure is generated in the oil passage 9 because the electric oil pump 8 does not discharge the hydraulic oil to the oil passage 9.
For this reason, the stroke valve 10 does not supply the hydraulic oil pressure to the hydraulic chamber 15, and the spool 11 does not receive the hydraulic pressure on the pressure receiving surface B. Therefore, the shift control pressure Pc in the hydraulic chamber 14 acts on the pressure receiving area A. The spool 11 is brought into the normal position shown in FIG. 2 (the same stroke position as in FIG. 1) by the force generated by the spring 12 and the spring force of the spring 12.

  At this time, since the stroke valve 10 communicates between the upstream oil passage portion 6a and the downstream oil passage portion 6b of the transmission control pressure oil passage 6, the transmission control pressure Pc is the upstream oil passage portion of the transmission control pressure oil passage 6. 6a and the downstream oil passage portion 6b reach the secondary pulley 1 as the movable flange pressing hydraulic pressure of the secondary pulley 1 so that the V belt type continuously variable transmission can achieve the target input rotational speed (target gear ratio). Shift control can be performed.

  During this time, the shift control pressure Pc (movable flange pressing hydraulic pressure of the secondary pulley 1) closes the check valve 18 due to the differential pressure with the electric oil pump pressure in the oil passage 9, The shift control pressure Pc (the movable flange pressing hydraulic pressure of the secondary pulley 1) can be prevented from leaking from the shift control pressure oil passage 6 (6b) toward the electric oil pump 8 and preventing the shift control described above.

During idle stop when the engine (prime motor) is stopped, hydraulic oil is not discharged from the prime mover drive oil pump 3 (see FIG. 1), so the shift control circuit 4 (see FIG. 1) does not output the shift control pressure Pc. .
Therefore, during the idle stop, the electric oil pump 8 is operated in order to increase the subsequent restart response or reduce the restart shock.

Therefore, the electric oil pump 8 discharges hydraulic oil to the oil passage 9, and electric oil pump hydraulic pressure is generated in the oil passage 9.
This electric oil pump hydraulic pressure reaches the inside of the hydraulic chamber 15 via the communication oil passage 19, and as a result, acts on the pressure receiving surface B of the spool 11 and biases it toward the position shown in FIG.
On the other hand, since the shift control pressure Pc is not output, the reverse force acting on the pressure receiving surface A of the spool 11 in the hydraulic chamber 14 is 0, and the reverse force applied to the spool 11 is a spring by the spring 12. Only power.

For this reason, the stroke valve 10 has the spool 11 placed in the limit position shown in FIG. 3 against the spring force of the spring 12 by the electric oil pump hydraulic pressure in the hydraulic chamber 15, and the speed change control pressure oil path 6 is set by the corresponding land of the spool 11. The downstream oil passage portion 6b is blocked.
Thus, the hydraulic pressure from the electric oil pump 8 to the oil passage 9 allows the secondary pulley 1 to move through the downstream oil passage portion 6b of the shift control pressure oil passage 6 while opening the check valve 18 as shown in FIG. It reaches the secondary pulley 1 as the flange pressing hydraulic pressure, and the V-belt continuously variable transmission can be brought into a state where power transmission is possible.

During this time, since the downstream oil passage portion 6b of the transmission control pressure oil passage 6 is blocked by the corresponding land of the spool 11, the electric oil pump hydraulic pressure reaching the downstream oil passage portion 6b of the transmission control pressure oil passage 6 is reduced. There is no leakage to the upstream oil passage portion 6a or the drain port 13 of the transmission control pressure oil passage 6,
As described above, the V-belt continuously variable transmission can be surely brought into a power transmission enabled state at the time of idling stop.

  Therefore, as soon as the engine (prime mover) is started by releasing the idle stop and the stroke valve 10 returns to the normal state of FIG. 2, the hydraulic pressure from the prime mover drive oil pump 3 (see FIG. 1) is ready to transmit power to the transmission. The V-belt continuously variable transmission can transmit power immediately after the start of the engine (prime mover) to improve the vehicle restart response and avoid a restart shock.

Next, the procedure for determining the failure of the electric oil pump 8 will be described.
In the present embodiment, in view of the above requirement, the failure determination of the electric oil pump 8 is performed before the idle stop is executed.
For this reason, while the vehicle is stopped before the idle stop is performed, that is, while the shift control pressure Pc is generated as shown in FIG. The electric oil pump 8 is test driven for failure determination by a pump test driving means (not shown).

  In addition, when the electric oil pump 8 is test-driven for failure determination only during the stop before the idling stop, it can be avoided that the electric oil pump 8 is wastefully tested during driving, Energy waste can be prevented and fuel consumption can be prevented from deteriorating.

  The electric oil pump 8 generates the same hydraulic pressure in the oil passage 9 (hydraulic chamber 15) as in the operation for improving the restart response described above with reference to FIG. Before the operation, as apparent from the above description of the operation, the pressure is applied to the pressure receiving surface B of the spool 11 which is in the normal position (the same position as in FIGS. 1 and 2) indicated by the two-dot chain line.

Here, when considering the force to bring the spool 11 to the normal position (the same position as in FIGS. 1 and 2) indicated by a two-dot chain line, this is generated by the shift control pressure Pc acting on the pressure receiving surface A of the spool 11. The sum of the force and the spring force of the spring 12.
By the way, the shift control pressure Pc acting on the pressure receiving surface A is set to the minimum required hydraulic pressure corresponding to the torque (computable from the throttle opening TVO and the vehicle speed VSP) to be transmitted by the V-belt continuously variable transmission. While the vehicle is stopped before the idling stop, the shift control pressure Pc is set to a low value in response to the throttle opening TVO = 0 and the vehicle speed VSP = 0.

Therefore, the force that keeps the spool 11 in the normal position indicated by the two-dot chain line in FIG. 4, that is, the sum of the force that is generated when the shift control pressure Pc acts on the pressure receiving surface A of the spool 11 and the spring force of the spring 12 Is small,
The electric oil pump pressure acting on the pressure receiving surface B of the spool 11 against these forces causes the spool 11 to stroke from the normal position indicated by the two-dot chain line in FIG. 4 to the pressure reducing position indicated by the solid line.
At the pressure reducing position of the spool 11, the stroke valve 10 causes the downstream oil passage portion 6b of the transmission control pressure oil passage 6 to communicate with the drain port 13, and coupled with the throttle function of the orifice 16, the movable flange pressing hydraulic pressure (shifting speed) of the secondary pulley 1. Reduce the control pressure Pc).

The decrease in the shift control pressure Pc (the hydraulic pressure applied to the movable pulley of the secondary pulley 1) accompanying the test drive of the electric oil pump 8 while the vehicle is stopped before the idle stop corresponds to the detected hydraulic pressure value detected by the hydraulic sensor 7 essential for the shift control. It can be detected by a decrease.
The electric oil pump failure determination means (not shown) that enables the electronic type monitors the detection value of the shift control pressure Pc (the hydraulic pressure applied to the movable pulley of the secondary pulley 1) detected by the hydraulic sensor 7,
When the electric oil pump 8 is stopped before the idling stop, when the electric oil pump 8 detects that the oil pressure detection value of the oil pressure sensor 7 has decreased as specified, the electric oil pump 8 normally outputs the pump oil pressure to the oil passage 9. It is determined that

By the way, in the event that the electric oil pump 8 cannot normally output the pump hydraulic pressure to the oil passage 9, even if this hydraulic pressure acts on the pressure receiving surface B of the spool 11, the spool 11 is shown as a solid line from the position of the two-dot chain line in FIG. Cannot be stroked to the indicated decompression position.
Accordingly, when the electric oil pump 8 fails, the movable flange pressing hydraulic pressure (shift control pressure Pc) of the secondary pulley 1 is not lowered as prescribed by the test drive of the electric oil pump 8 while the vehicle is stopped before the idle stop. The phenomenon can be detected from the hydraulic pressure detection value of the hydraulic sensor 7 to determine whether the electric oil pump 8 has failed.

  Since the failure determination of the electric oil pump 8 according to the above-described embodiment is performed while the vehicle is stopped before the idle stop, the idle stop prohibition when the electric oil pump 8 is broken is prohibited as in the case of performing the failure determination after the idle stop. In the control, it is possible to avoid the foolishness of starting the engine (the prime mover) again for the purpose of prohibiting the idle stop after performing the idle stop once.

Moreover, the failure determination of the electric oil pump 8 according to the above-described embodiment does not require any hydraulic sensor for detecting the electric oil pump hydraulic pressure, and is based on the existing hydraulic sensor 7 that is essential for the shift control in the shift control pressure circuit 6. Since it is possible to monitor the hydraulic pressure detection value and determine the failure of the electric oil pump 8,
Even if the failure determination of the electric oil pump 8 is performed before the execution of the idle stop in view of the above requirements,
Without adding a hydraulic sensor that directly detects the hydraulic pressure of the electric oil pump 8, the failure determination can be performed using the hydraulic pressure detection value from the existing hydraulic sensor 7 in the shift control pressure circuit 6,
It is possible to avoid the problem of the cost increase due to the addition of the hydraulic sensor and the problem of the decrease in reliability.

In addition, an electric sensor for detecting the drive current and drive power of the electric oil pump 8 is not provided to determine the failure of the electric oil pump 8, but the shift control pressure Pc is reduced in response to the electric oil pump hydraulic pressure. Since such a stroke valve 10 (pressure reducing valve means) is provided and the failure of the electric oil pump 8 is determined by monitoring the decrease in the shift control pressure Pc,
Actually, even though the hydraulic pressure from the electric oil pump 8 is not as prescribed, it is possible to avoid the adverse effect of erroneously determining that it is normal.

In FIG. 4, while the vehicle is running, the shift control pressure Pc acting on the pressure receiving surface A is set to a high value in response to the throttle opening TVO> 0 and the vehicle speed VSP> 0. The power to keep
Even with the test drive of the electric oil pump 8, the electric oil pump pressure acting on the pressure receiving surface B of the spool 11 does not cause the spool 11 to stroke from the two-dot chain line position to the reduced pressure position indicated by the solid line, and shift control during traveling Will not be disturbed.

  For this reason, when the illustrated stroke valve 10 is used, the electric oil pump test drive means (not shown) does not necessarily detect that the vehicle is stopped before the idle stop as described above, and the electric oil pump 8 is used for failure determination. However, if the electric oil pump 8 is arbitrarily driven by test, the stroke valve 10 is automatically driven by the above operation when the vehicle stops before the idle stop. It is possible to create a state in which the failure determination of the oil pump 8 is possible.

  In the above embodiment, the stroke valve 10 is used as a pressure reducing valve. However, it goes without saying that other types of mechanical valves having the same pressure reducing function or electronic control valves may be used.

Further, in the above, the electric oil pump failure determination means (not shown) directly monitors the detected value of the shift control pressure Pc (the movable flange pressing hydraulic pressure of the secondary pulley 1) detected by the hydraulic sensor 7, and this is the idle stop. Although it was determined that the electric oil pump 8 was broken with a state in which the electric oil pump 8 was not lowered as prescribed by the test drive of the electric oil pump 8 during the previous stop, instead,
It is also possible to execute the control program shown in FIG. 5 and indirectly monitor the hydraulic pressure detection value of the hydraulic sensor 7 to determine the failure of the electric oil pump 8.

The control program shown in FIG. 5 will be described below.
In step S11, it is checked whether the vehicle is stopped before the idle stop,
If the vehicle is not stopped before the idle stop, that is, if it is running, the failure determination of the electric oil pump 8 should not be performed for the above-described reason, so the control is ended without performing the determination,
If the vehicle is stopped before the idle stop, the control proceeds to step S12 and the failure determination of the electric oil pump 8 is executed as follows.

In step S12, it is checked whether there is any idle stop system abnormality except for the electric oil pump 8.
When there is an idle stop system abnormality, the idle stop itself is not executed, so there is no need to operate the electric oil pump 8, and since the failure determination is meaningless, the control is terminated without performing the determination.

If it is determined in step S12 that there is no idle stop system abnormality,
First, in step S13, the command value related to the current shift control pressure Pc is stored as the shift control pressure command value Pco at the start of the electric oil pump test drive.
Next, in step S14 corresponding to the electric oil pump test drive means, the electric oil pump 8 is driven for test,
In the next step S15, the shift control pressure command value Pco at the start of the electric oil pump test drive is subtracted from the command value (shift control pressure command value) Pcr related to the shift control pressure Pc during the electric oil pump test drive, A difference value ΔP = Pcr−Pco between the two is calculated.

The difference ΔP between the shift control pressure command value Pcr during the electric oil pump test drive and the shift control pressure command value Pco at the start of the electric oil pump test drive calculated in this way is
As shown in FIG. 6, Pco and Pcr when the electric oil pump 8 is driven to test the failure during the instant t1 to t2 in the stop state before the idling stop with the engine speed Ne kept at the idling speed. As is clear from the change time chart of
This represents the amount of change in the shift control pressure command value Pcr during the electric oil pump test drive (t1 to t2).

By the way, as described above, the shift control pressure command value Pcr during the electric oil pump test drive is detected by the hydraulic sensor 7 that detects the shift control pressure Pc (the hydraulic flange pressing hydraulic pressure of the secondary pulley 1). The gear ratio is calculated by calculating how far the gear shift control pressure Pc is required to achieve the target input speed (target gear ratio), and is changed by feedback control so that this gap is eliminated. Because it is
Monitoring the change amount ΔP of the shift control pressure command value Pcr during the electric oil pump test drive as described above indirectly monitors the change amount of the hydraulic pressure detection value of the hydraulic sensor 7.

  Therefore, the change amount ΔP of the shift control pressure command value Pcr during the electric oil pump test drive (t1 to t2) is larger than the set value ΔPs for electric oil pump abnormality determination as shown in FIG. The reduction in the shift control pressure Pc (hydraulic flange pressing hydraulic pressure of the secondary pulley 1) accompanying the test drive of the pump 8 is as specified, and the shift control pressure command value Pcr is as specified by the feedback control corresponding to this decrease. The increase means that the electric oil pump 8 is normal, and conversely, Pcr ≦ ΔPs means that the electric oil pump 8 is in a failure state.

  Therefore, in step S16 in FIG. 5, a state in which the change amount ΔP of the shift control pressure command value Pcr during the electric oil pump test drive (t1 to t2) is larger than the set value ΔPs for determining the electric oil pump abnormality is the set time. Whether or not the electric oil pump 8 is normal is determined based on whether or not the operation continues.

Even if the change amount ΔP of the shift control pressure command value Pcr during the electric oil pump test drive (t1 to t2) is larger than the set value ΔPs for determining the electric oil pump abnormality in step S16, this state continues for the set time. The change amount ΔP of the shift control pressure command value Pcr during the electric oil pump test drive (t1 to t2) is determined to be equal to or less than the set value ΔPs for electric oil pump abnormality determination. Is
Based on the determination result that the electric oil pump 8 is out of order, the control proceeds to step S17 to command prohibition of idle stop when the electric oil pump is out of order and to stop the test drive of the electric oil pump 8.

Therefore, step S16 corresponds to the electric oil pump failure determination means,
In step S16, the change amount ΔP of the shift control pressure command value Pcr during the electric oil pump test drive (t1 to t2) is larger than the set value ΔPs for determining the electric oil pump abnormality, and this state is the set time. When the electric oil pump 8 is judged to have continued for a long time,
Control is terminated without executing step S17, and idle stop is executed as usual when a predetermined condition is satisfied when the vehicle stops.

According to the electric oil pump failure determination shown in FIGS.
Despite the test drive of the electric oil pump 8 (step S14), when the change amount ΔP of the shift control pressure command value Pc by the feedback control is not more than the specified value ΔPs (step S16), the electric oil pump 8 has failed. From judging that
The failure determination of the electric oil pump 8 is performed using a calculation result that contributes to the shift control in the shift control circuit 4, and a highly accurate failure determination can be realized.

Further, in determining whether the electric oil pump 8 is normal, not only the condition that the change amount ΔP of the shift control pressure command value Pc during the test drive is larger than the specified value ΔPs but also the state of ΔP> ΔPs over the set time. In order to determine that the electric oil pump 8 is normal only when it is continued (step S16),
It is possible to avoid the possibility of erroneously determining that the electric oil pump 8 is normal only by temporary ΔP> ΔPs, and that the idle stop is executed even though the electric oil pump 8 is out of order. It can be resolved.

Further, the change ΔP of the shift control pressure command value Pcr during the electric oil pump test drive (t1 to t2 in FIG. 6), which is used for determining the failure of the electric oil pump 8, is determined when the electric oil pump 8 starts the test drive. Since it is the amount of deviation from the shift control pressure command value Pco at (t1 in FIG. 6),
The change amount ΔP of the shift control pressure command value Pcr during the electric oil pump test drive is compared with the latest reference value, and the failure determination of the electric oil pump 8 based on the change amount ΔP can be performed more accurately. .

1 is a system diagram showing an embodiment of a failure determination device for an electric oil pump for improving restart response configured to be used for a vehicle with an idle stop equipped with a V-belt type continuously variable transmission. FIG. 2 is an operation explanatory diagram showing the stroke valve in FIG. 1 in a state when only a shift control pressure is supplied. FIG. 2 is an operation explanatory view showing the stroke valve in FIG. 1 in a state during idle stop. FIG. 2 is an operation explanatory view showing the stroke valve in FIG. 1 in a state when the electric oil pump is test-driven for failure determination while the vehicle is stopped before idling stop to which a shift control pressure is supplied. It is a flowchart which shows an example of the control program regarding failure determination of an electric oil pump. 6 is an operation time chart of electric oil pump failure determination according to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Secondary pulley 2 V belt 3 Motor drive oil pump 4 Shift control circuit 5 Operation state detection means 6 Shift control pressure oil path 7 Hydraulic sensor 8 Electric oil pump 9 Electric oil pump pressure oil path
10 Stroke valve (pressure reducing means)
11 Spool
12 Spring
13 Drain port
14 Hydraulic chamber
15 Hydraulic chamber
16 Orifice
17 Connection oil passage
18 Check valve
19 Connection oil passage

Claims (9)

The motor can travel through the transmission with the power from the prime mover, and during the operation of the prime mover, the transmission is controlled by the hydraulic pressure from the prime mover driven oil pump driven by the prime mover, and predetermined conditions are met when the vehicle is stopped. Idle stop that automatically stops the prime mover and improves the restart response by making the transmission ready to transmit power by hydraulic pressure from the electric oil pump instead of the prime mover driven oil pump In vehicles with
Electric oil pump test drive means for driving the electric oil pump during operation of the prime mover;
Pressure reducing valve means for reducing the shift control pressure for the shift control in response to the hydraulic pressure from the electric oil pump that is test-driven by the means;
An electric oil pump failure determination means for determining that the electric oil pump is defective if the reduction of the shift control pressure is not as specified, is used for a transmission for a vehicle with an idle stop. Failure determination device for electric oil pump for starting response improvement. In the failure determination device of the electric oil pump for recurrent response improvement according to claim 1,
The electric oil pump test drive means is a test drive of the electric oil pump when the vehicle is in a stop state before the idle stop. Oil pump failure judgment device. In the failure determination device for the electric oil pump for recurrent response improvement according to claim 1 or 2,
The pressure reducing valve means responds to the hydraulic pressure from the electric oil pump being tested and the shift control pressure, and the shift control pressure is low when the shift control pressure is a low value corresponding to the stop state before idling stop. When the speed change control pressure is high during traveling, the speed change control pressure is used as it is for the speed change control. Failure determination device for electric oil pump for improving response. In the failure determination device of the electric oil pump for restart response improvement according to claim 3,
The pressure reducing valve means is a stroke valve that receives the hydraulic pressure from the electric oil pump during the test drive and the shift control pressure face to face and responds to these hydraulic pressures. A failure determination device for electric oil pumps for improving rebound response in machines. In the failure determination device of the electric oil pump for restart response improvement according to claim 4,
The pressure reducing valve means of the stroke valve type is configured so that the hydraulic pressure from the electric oil pump is driven by the prime mover at a stroke position corresponding to the hydraulic pressure from the electric oil pump while the shift control pressure is not generated during the idle stop. An apparatus for determining a failure of an electric oil pump for recurrent response improvement used in a transmission of a vehicle with an idle stop, which also serves as a shut-off valve for preventing a reverse flow toward the oil pump. In the failure determination device of the electric oil pump for recurrent response improvement according to any one of claims 1 to 5,
A check valve that closes in response to the shift control pressure is inserted in an oil passage for directing hydraulic pressure from the electric oil pump to the transmission, and is used for a transmission for a vehicle with an idle stop. Failure determination device for electric oil pump for improving restart response. 7. The transmission according to claim 1, wherein the transmission operates the shift control pressure command value by feedback control based on a hydraulic pressure detection value from a hydraulic pressure sensor that detects the shift control pressure. In the failure determination device for the electric oil pump for recurrent response improvement described in item 1,
The electric oil pump failure determination means determines that the electric oil pump has failed when the amount of change in the shift control pressure command value by the feedback control is equal to or less than a specified value despite the test drive of the electric oil pump. A failure determination device for an electric oil pump for recurrent response improvement used in a transmission of a vehicle with an idle stop, characterized in that the determination is performed. In the failure determination device of the electric oil pump for restart response improvement according to claim 7,
When the electric oil pump failure determination means continues the state where the change amount of the shift control pressure command value by the feedback control is not more than a specified value during the test drive of the electric oil pump for a set time or more, An apparatus for determining a failure of a rebound response improving electric oil pump for use in a transmission of a vehicle with an idle stop, wherein the pump is determined to be normal. In the failure determination device for the electric oil pump for recurrent response improvement according to claim 7 or 8,
The electric oil pump failure determination means is configured such that a change amount of the shift control pressure command value by the feedback control during the electric oil pump test drive is different from a shift control pressure command value at the start of the test drive of the electric oil pump. A failure determination device for an electric oil pump for restarting response improvement used in a transmission of a vehicle with an idle stop.

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