JP2015105731A - Lock-up clutch hydraulic control device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lock-up clutch hydraulic control device of a vehicle, capable of performing a well-responsive and fast OFF operation of a lock-up clutch while improving fuel consumption of the vehicle.SOLUTION: This invention relates to a lock-up clutch hydraulic control device A of a vehicle comprising: an oil pump 2 driven by an engine 1; and a hydraulic circuit 4 for use in ON-OFF controlling of a lock-up clutch 30 of an automatic transmission through application of hydraulic oil pressure generated by this oil pump 2. In the hydraulic circuit 4, an accumulator 6 is provided, and when OFF operation of the lock-up clutch 30 is started, a hydraulic oil pressure accumulated in the accumulator 6 is supplied to the lock-up clutch 30. The pressure accumulation in the accumulator 6 is carried out only during a period in which a vehicle speed is decreased from a prescribed middle or high speed range.

Description

  The present invention relates to a lockup clutch hydraulic control device in a vehicle for performing on / off hydraulic control of a lockup clutch incorporated in a fluid coupling of an automatic transmission mounted on a vehicle such as an automobile.

  In a vehicle equipped with an automatic transmission, when a sudden braking occurs during traveling, a lockup clutch of a torque converter is turned off to prevent engine stall (hereinafter referred to as engine stall) (for example, Patent Document 1). The lock-up clutch OFF operation for avoiding the engine stall is required to be performed quickly with good responsiveness. Therefore, Patent Document 1 employs a means for generating a converter hydraulic pressure in which the hydraulic pressure is temporarily increased by using a regulator valve and supplying the hydraulic pressure to the lock-up clutch when the lock-up clutch is started to be turned off. Yes.

  However, the prior art has room for improvement as described below.

  That is, in the prior art, since the hydraulic pressure supplied to the lockup clutch is temporarily increased when the lockup clutch is turned off, the hydraulic pressure generated by the oil pump is used. This affects the hydraulic circuit. As a result, there is a risk that the hydraulic pressure is insufficient in other circuits. In order to solve this problem, it is sufficient to increase the oil pressure generated by the oil pump by increasing the number of revolutions of the vehicle engine, or to increase the capacity of the oil pump. Gets worse. Further, when the capacity of the oil pump is increased, there is a disadvantage in terms of weight and manufacturing cost.

  As a measure for solving such a problem, the present inventor has conceived of using an accumulator and supplying the hydraulic pressure accumulated in the accumulator to the lock-up clutch during the off operation. . However, simply using an accumulator may cause problems such as an increase in engine load and accumulation of fuel in the accumulator, resulting in poor fuel consumption.

Japanese Patent Laid-Open No. 2-309055

  The present invention has been conceived under the circumstances described above, and it is possible to lock a vehicle in a vehicle that can quickly turn off the lockup clutch with good responsiveness while improving the fuel efficiency of the vehicle. An object of the present invention is to provide an up-clutch hydraulic control device.

  In order to solve the above problems, the present invention takes the following technical means.

A lockup clutch hydraulic pressure control apparatus for a vehicle provided by the present invention controls on / off of a lockup clutch of an automatic transmission using an oil pump driven by an engine and a hydraulic pressure generated by the oil pump. A hydraulic circuit for a lockup clutch in a vehicle, wherein the hydraulic circuit is provided with an accumulator, and pressure is accumulated in the accumulator when the lockup clutch is started to be turned off. The hydraulic pressure is supplied to the lock-up clutch, and the accumulator is accumulated only during a period when the vehicle speed is decelerating from a predetermined medium-high speed range. It is a feature.

According to such a configuration, the following effects can be obtained.
First, when the lock-up clutch is started to be turned off, the hydraulic pressure previously accumulated in the accumulator is supplied to the lock-up clutch. Therefore, the lock-up clutch is quickly turned off with high responsiveness using this hydraulic pressure. be able to. Therefore, the engine stall resistance is improved. Since the engine stall performance at the time of engine low-speed running is also improved, the vehicle can be run at a low speed with the engine speed being lower, and fuel efficiency can be improved.
Second, if the hydraulic pressure accumulated in the accumulator is used for the off operation of the lock-up clutch, unlike the case of Patent Document 1, the possibility of insufficient hydraulic pressure in other hydraulic circuits is eliminated. Therefore, it is possible to improve the fuel efficiency of the vehicle by eliminating the need to increase the engine speed or increase the capacity of the oil pump as a means for solving the shortage of hydraulic pressure in other hydraulic circuits. It becomes.
Thirdly, the accumulator is accumulating during a period in which the vehicle speed is decelerating from a predetermined medium to high speed (for example, 30 km / h or more) (specifically, lockup and fuel cut are performed). However, during this period, the driving force of the engine is not used for vehicle travel. Therefore, if this period is set as the pressure accumulation period for the accumulator, a load is applied to the engine during this period. The oil pump can be driven only by the deceleration energy of the vehicle without being applied. Therefore, it is possible to prevent deterioration in fuel consumption caused by accumulated pressure in the accumulator.

  In the present invention, preferably, the accumulator is connected to both an on-pressure oil passage and an off-pressure oil passage for supplying a lockup on pressure and a lockup off pressure to the lockup clutch, respectively. The pressure accumulation to the accumulator is performed by supplying hydraulic pressure from the on-pressure oil passage, and when the lock-up clutch starts to be turned off, the hydraulic pressure escape from the accumulator to the on-pressure oil passage is prevented. Thus, the on-pressure oil passage and the off-pressure oil passage are configured so that oil pressure is supplied to the off-pressure oil passage, and during the period excluding the time when accumulating pressure is accumulated in the accumulator and the time when the lock-up clutch is turned off. Are disconnected from the accumulator and disconnected from each other.

According to such a configuration, the following effects can be obtained in addition to being able to accurately perform the on / off operation of the lockup clutch.
First, the accumulator can be placed close to the lockup clutch. For this reason, the hydraulic pressure is quickly supplied from the accumulator at the start of the off-operation of the lockup clutch. As a result, the responsiveness of the lockup clutch is made more excellent, and it is more preferable in improving the engine stall resistance performance. Second, there is a large pressure difference in the on-pressure oil passage and the off-pressure oil passage to which the accumulator is connected. Therefore, the harmful effect of connecting the accumulator can be reduced.
Third, even when the vehicle is running in a fuel cut state, it is possible to accumulate pressure in the accumulator.

  Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

It is explanatory drawing which shows typically an example of the lockup clutch hydraulic control apparatus in the vehicle which concerns on this invention. (A)-(c) is explanatory drawing which shows the control state of the accumulator which comprises the apparatus shown in FIG. It is a flowchart which shows an example of the operation processing procedure of the control part of the apparatus shown in FIG.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  A lock-up clutch hydraulic control device A (hereinafter abbreviated as “hydraulic control device A”) in the vehicle shown in FIG. 1 includes an oil pump 2 driven by an engine 1 for driving the vehicle, and a torque converter for a belt-type continuously variable transmission. 3. Hydraulic pressure for controlling on / off (engaged state) / off (unengaged state) of the lockup clutch 30 using the hydraulic pressure generated by the lockup clutch 30 and the oil pump 2 of the torque converter 3 A circuit 4 and a control unit 5 are provided.

  The torque converter 3 is the same as the existing one, and includes a pump 3a, a turbine 3b, and a stator 3c. The lockup clutch 30 is turned on / off based on the pressure difference between the lockup on pressure and the lockup off pressure supplied to the ports Pa and Pb.

  The hydraulic circuit 4 receives primary and secondary regulator valves V1 and V2 that regulate the hydraulic pressure of the oil discharged from the oil pump 2, the oil pressure that has passed through them, and the lockup on pressure to the lockup clutch 30 and A lockup control valve V3 for controlling the supply of the lockup off pressure, an accumulator 6, and an accumulator control electromagnetic valve 7 are provided.

  The accumulator 6 is bridged to both an on-pressure oil passage 4a and an off-pressure oil passage 4b for supplying a lockup on pressure and a lockup off pressure to the lockup clutch 30 via a bypass oil passage 41, respectively. It is connected to. As shown in FIG. 2, the accumulator 6 can be set to the normal state of FIG. 2A, the pressure accumulation state of FIG. 2B, and the open state of FIG. The electromagnetic valve 7 is a system in which a spool 71 is moved by an electromagnetic solenoid 70, and ports P1 to P3 connected to the off pressure oil passage 4b, a port P4 connected to the accumulator 6, and a port P5 connected to the on pressure oil passage 4a. have.

In the normal state of FIG. 2A, the on-pressure oil path 4a and the off-pressure oil path 4b are disconnected from the accumulator 6. Further, neither the on-pressure oil passage 4 a nor the off-pressure oil passage 4 b is connected via the oil passage 41. Each of the on-pressure oil passage 4 a and the off-pressure oil passage 4 b can independently supply hydraulic pressure toward the lockup clutch 30. At this time, the electromagnetic valve 7 is in communication with ports P1 and P2 and closed with ports P3 and P5.
In the pressure accumulation state of FIG. 5B, the hydraulic pressure is supplied to the accumulator 6 from the on-pressure oil passage 4a. Each of the on-pressure oil passage 4 a and the off-pressure oil passage 4 b can independently supply hydraulic pressure to the lockup clutch 30. At this time, in the electromagnetic valve 7, the ports P1 and P2 are in communication, the port P3 is closed, and the ports P4 and P5 are in communication.
In the open state of FIG. 3C, the hydraulic pressure accumulated in the accumulator 6 is supplied to the off-pressure oil passage 4b. At this time, hydraulic escape to the on-pressure oil passage 4a is prevented. The on-pressure oil passage 4 a is in a state where hydraulic pressure can be supplied to the lockup clutch 30. Preferably, the off-pressure oil passage 4b is blocked at the position of the electromagnetic valve 7 so that the hydraulic pressure supply to the side opposite to the lock-up clutch 30 is blocked. At this time, the electromagnetic valve 7 is disconnected between the ports P1 and P2, the ports P3 and P4 are in communication, and the port P5 is in a closed state.

  In FIG. 1, the control unit 5 is, for example, an ECU, and controls the electromagnetic valve 7 and controls to set the accumulator 6 to one of the three states shown in FIG. 2. The control unit 5 receives various signals from the vehicle speed sensor 50, the brake negative pressure detection unit 51, the ABS device 52, and the like, and determines whether or not to turn off the lockup clutch 30 based on this signal. The control corresponding to the determination result is performed. Details of the operation control executed by the control unit 5 will be described later.

  Next, the operation of the hydraulic control apparatus A will be described. In addition, an example of an operation processing procedure executed by the control unit 5 will be described with reference to the flowchart of FIG.

  First, when the accumulator 6 is in a pressure-accumulated state, the engine 1 is allowed to rotate at a low speed, and the accumulator 6 is set to the normal state shown in FIG. 2A (S1: YES, S2 , S3). The engine 1 is allowed to rotate at a low speed when the accumulator 6 has already accumulated pressure, and the hydraulic circuit is increased by increasing the number of revolutions of the oil pump 2 for the purpose of promptly turning off the lockup clutch 30. This is because it is not necessary to increase the hydraulic pressure of 4 more than necessary. When the engine 1 is in a low rotation permission state, fuel consumption can be improved.

  Next, it is determined whether or not the vehicle has a predetermined rapid deceleration (S4). This determination is for avoiding engine stall. Specifically, it is a sudden deceleration of the vehicle that may cause engine stall based on changes in vehicle deceleration, brake negative pressure, ABS signal, etc. It is to judge whether or not.

  When it is determined that the speed is a predetermined sudden deceleration, the open state of the accumulator 6 shown in FIG. 2C is immediately set (S4: YES, S5). As a result, the lockup clutch 30 can be quickly turned off with good responsiveness using the hydraulic pressure accumulated in the accumulator 6. Since the accumulator 6 is provided at a position close to the lock-up clutch 30, the responsiveness can be further improved. Therefore, the engine stall can be made difficult to occur. Further, if the hydraulic pressure accumulated in the accumulator 6 is used for the off operation of the lock-up clutch 30, the possibility of insufficient hydraulic pressure in other hydraulic circuits using the hydraulic pressure by the oil pump 2 is eliminated. As a result, there is no need to increase the engine speed or increase the capacity of the oil pump in order to prevent other hydraulic circuits from having insufficient hydraulic pressure. The hydraulic pressure supply by the accumulator 6 is for the purpose of quickly turning off the lock-up clutch 30 with good responsiveness. Therefore, the hydraulic pressure release state of the accumulator 6 is limited to the initial stage of the lock-up clutch 30 off operation, and the release time Is a so-called moment or short time. The accumulator 6 is immediately returned to the normal state of FIG. 2A after finishing the open state (S6).

  Unlike the above, when the accumulator 6 is not in a state where pressure has been accumulated, the engine 1 is set in a low rotation non-permission state (S1: NO, S7). As a result, the hydraulic pressure generated using the oil pump 2 is increased in advance, and the lockup clutch 30 can be turned off as quickly as possible even when the accumulator 6 has not accumulated pressure.

The accumulator 6 accumulates pressure in the manner shown in FIG. 2 (b), but this accumulator state starts when the vehicle speed falls from a predetermined medium to high speed range (for example, 30 km / h or more). When the deceleration state ends, the pressure accumulation state is canceled and the accumulator 6 is returned to the normal state (S8: YES, S9, S10: YES, S6). In other words, the hydraulic control device A is configured such that the accumulator 6 accumulates pressure only during a period in which the vehicle is decelerating from a predetermined medium-high speed range, and not at any other time. Yes. The deceleration period of the vehicle speed described above is a state where the driving force of the engine 1 is not used for vehicle travel. If this period is set as a pressure accumulation period for the accumulator, the vehicle is not loaded during this period. The oil pump 2 can be driven by the deceleration energy. Therefore, it is possible to prevent deterioration in fuel consumption caused by accumulated pressure in the accumulator 6.

  The present invention is not limited to the contents of the embodiment described above. The specific configuration of each part of the lockup clutch hydraulic control device in the vehicle according to the present invention can be variously modified within the scope intended by the present invention.

  In the embodiment described above, the accumulator 6 is accumulated by supplying hydraulic pressure from the on-pressure oil passage 4a to the accumulator 6, but the present invention is not limited to this. It is also possible to connect the accumulator 6 to an oil path different from the on-pressure oil path 4a, and to supply the accumulator 6 with the hydraulic pressure for pressure accumulation from this oil path. In this case, the accumulator 6 is not connected in a bridging manner to the on-pressure oil passage 4a and the off-pressure oil passage 4b, but such a configuration is also allowed.

A Vehicle lockup clutch hydraulic control device 1 Engine 2 Oil pump 3 Torque converter 30 Lockup clutch 4 Hydraulic circuit 4a On-pressure oil passage 4b Off-pressure oil passage 6 Accumulator

Claims (2)

An oil pump driven by an engine;
A hydraulic circuit for controlling on / off of the lockup clutch of the automatic transmission using the hydraulic pressure generated by the oil pump;
A lockup clutch hydraulic control device in a vehicle, comprising:
The hydraulic circuit is provided with an accumulator,
When the lock-up clutch starts to be turned off, the hydraulic pressure accumulated in the accumulator is supplied to the lock-up clutch.
The accumulation of pressure in the accumulator is performed only during a period in which the vehicle speed is decelerated from a predetermined medium to high speed range. A lockup clutch hydraulic control device for a vehicle according to claim 1,
The accumulator is connected in a bridging manner to both an on-pressure oil passage and an off-pressure oil passage for supplying a lock-up on-pressure and a lock-up off-pressure to the lock-up clutch,
Accumulation in the accumulator is performed by supplying hydraulic pressure from the on-pressure oil passage,
At the time of starting the off-operation of the lock-up clutch, the hydraulic pressure is supplied to the off-pressure oil passage in a state where hydraulic escape from the accumulator to the on-pressure oil passage is prevented,
During pressure accumulation to the accumulator and during a period excluding when the lock-up clutch is turned off, the on-pressure oil path and the off-pressure oil path are disconnected from the accumulator and are not in communication with each other. A lockup clutch hydraulic control device for a vehicle.

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