JP3596033B2 - Lockup control device for automatic transmission - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to lock-up control means for connecting an input shaft and an output shaft of a fluid coupling such as a torque converter by engaging a clutch mechanism, and relates to an automatic transmission for connecting an engine of an automobile or the like to an axle. The present invention relates to a lock-up control device for a machine.
[0002]
[Prior art]
It is known that an automatic transmission that connects an engine of an automobile and an axle is configured by a combination of a fluid coupling that forms a power transmission mechanism such as a torque converter and a transmission mechanism that varies a transmitted rotation speed. Have been. Since the torque converter is configured to transmit power via a fluid such as oil, a slip occurs when transmitting the power. Since such a slip phenomenon directly affects fuel efficiency and the like, such a torque converter is provided with a lock-up clutch mechanism for directly connecting the input shaft and the output shaft.
[0003]
As a lockup control device in such an automatic transmission, for example, a technique disclosed in Japanese Patent Application Laid-Open No. 5-263919 is known. The device shown here has a solenoid for lock-up control, determines the position of the spool valve (opening area of the spool) by the output pressure of this solenoid, and regulates the control pressure of the lock-up clutch. I have. For this reason, the control pressure can be adjusted only with an accuracy obtained by multiplying the accuracy of the output pressure of the solenoid by a certain gain, and there is a possibility that the control accuracy of the lock-up clutch may be deteriorated.
[0004]
In the lock-up clutch control device disclosed in Japanese Patent Application Laid-Open No. 2-304260, the control pressure of the lock-up clutch is regulated by a direct lock-up control solenoid. However, in order to operate a spool valve that connects the lock-up control oil chamber and the solenoid, another solenoid is required, and the configuration is complicated.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the above points, and has a sufficiently simplified configuration in which a single control valve mechanism using an electromagnetic valve controls switching of a lock-up clutch mechanism between an engaged state and an open state. It is an object of the present invention to provide a lock-up control device for an automatic transmission that connects an engine of an automobile and an axle, for example, and that can easily secure control accuracy.
[0006]
[Means for Solving the Problems]
A lockup control device for an automatic transmission according to the present invention couples a fluid coupling for transmitting rotational power from an input shaft to an output shaft via a fluid, and the input shaft and the output shaft bypassing the fluid coupling. a clutch mechanism for a lock-up, and a control valve for controlling a control hydraulic pressure command switching the engagement state and the open state of the clutch mechanism, the first state and the second based on a control hydraulic pressure that is controlled by the control valve A lock-up control device for an automatic transmission, the lock-up control device comprising: a first hydraulic chamber for applying a hydraulic pressure in the fluid coupling to release the lock-up clutch mechanism; A second hydraulic chamber for applying hydraulic pressure so as to fasten the clutch mechanism; and in the first state of the direction switching valve, a second hydraulic chamber is provided in the first hydraulic chamber. A reference hydraulic pressure for controlling lock-up of a pressure higher than the chamber is supplied, a first hydraulic path for opening the lock-up clutch mechanism is formed, and in the second state of the directional control valve, the fluid A reference pressure for controlling the lock-up is supplied to a second hydraulic chamber in the coupling, a control pressure controlled by the control valve is supplied to a first hydraulic chamber in the fluid coupling, and the lock is A second hydraulic path capable of engaging the clutch mechanism for up is formed, and in the second state of the direction switching valve, the control oil pressure set by the control valve is used to engage the clutch mechanism for lock-up. A control hydraulic pressure supplied to a second hydraulic path to control the engagement state of the clutch mechanism by a control hydraulic pressure set by the control valve, and the control valve switches the direction in the inoperative state. Is set in the first state, and the control oil pressure is set in the operating state of the control valve to set the direction switching valve in the second state. In the second state, the control oil pressure is set in the control state. A control set by a valve and lower than a reference pressure for controlling lock-up supplied to a first hydraulic chamber in the fluid coupling by the second hydraulic path to a second hydraulic chamber in the fluid coupling; Hydraulic pressure can be supplied, and the lock-up engagement state can be controlled .
[0007]
[Action]
In the lockup control device of the automatic transmission configured as described above, by switching the operation state of the control valve, the direction switching valve is switched and driven, and by the control oil pressure set in the non-operation state of the control valve, A first hydraulic path is formed in which the direction switching valve opens the clutch mechanism of the fluid coupling. Then, the direction switching valve is set to the second state in the operation state of the control valve, a second hydraulic path for the clutch mechanism is formed, the clutch mechanism is engaged, and the lock-up state is set. Then, in the engaged state of the clutch mechanism, by controlling the control oil pressure obtained from the control valve directly to the clutch mechanism, the engaged state of the clutch mechanism, that is, the lock-up state is controlled by the control valve. As a result, a great effect is exhibited in simplifying the configuration of the lockup control mechanism.
[0008]
【Example】
An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration, which is provided with a solenoid valve 11 having one solenoid mechanism. The electromagnetic valve 11 is configured to be ON / OFF controlled based on a lock-up control command of a torque converter 12 constituting a fluid coupling mechanism, that is, so-called opening degree is controlled in a duty proportional manner. When the solenoid valve 11 is not energized, the input oil pressure of the port 111 is communicated with the output port 112, and the secondary pressure PL2 set by the regulator is applied to the port 111, and this pressure PL2 is used as the control oil pressure Pc. (PL2 = Pc). When the solenoid valve 11 is excited, the port 112 is connected to the discharge side drain 113. Then, the pressure of the output side port 111 is set to an arbitrary value in the state of “Pc <PL2” by performing high-speed switching control between the non-excited state and the excited state of the solenoid valve 11.
[0009]
For such an electromagnetic valve 11, a spool valve 13 which is a direction switching valve for lock-up control is provided. The spool valve 13 is provided with hydraulic chambers 131 and 132 at both ends of a valve element 130, and these hydraulic chambers 131 and 132 are provided with ports 141 and 142, respectively. The valve element 130 is moved in the right or left direction in the figure according to the oil pressure set in the hydraulic chambers 131 and 132. The valve element 130 is pushed to the hydraulic chamber 132 side in the hydraulic chamber 131. A spring 15 is provided, and a control oil pressure Pc from the solenoid valve 11 is applied via a port 141.
[0010]
A secondary pressure PL2 is applied to the hydraulic chamber 132 through a port 142. Accordingly, when the solenoid valve 11 is not operated and “Pc = PL2”, and the internal oil pressures of the hydraulic chambers 131 and 132 are equal, the valve element 130 is set to the right side by the pressure of the spring 14 as shown in the figure. Have been. When the solenoid valve 11 is actuated to be in the state of “Pc <PL2”, the pressure in the hydraulic chamber 132 becomes larger than the sum of the pressure in the hydraulic chamber 131 and the force between the spring 15 and the valve body 130 Will be moved to the left.
[0011]
The spool valve 13 is provided with a port 143 on which the output pressure Pc from the solenoid valve 11 acts, a port 144 on which the secondary pressure PL2 acts, in addition to the input ports 141 and 142 at both ends, and an oil cooler (not shown). A port 145 for supplying the discharged oil to is provided. And, it has ports 161, 162, 163 selectively communicated with the ports 143-145 according to the position of the valve element 130, and in the state in which the valve element 130 is moved to the right side, the ports 144, 162 are provided. Are communicated, and ports 145 and 163 are communicated. Conversely, when the valve body 30 is moved to the left, the ports 143 and 161 communicate with each other, and the ports 144 and 163 communicate with each other.
[0012]
The torque converter 12 has an on-port 172 together with an off-port 171, a clutch control oil chamber 18 is set continuously to the off-port 171, and a clutch mechanism for setting a lock-up state according to the pressure state of the control oil chamber 18. 19 is controlled so that the input shaft and the output shaft are connected. When the secondary pressure PL2 acts on the off port 171, the control oil flows from the clutch control oil chamber 18 to the torque converter oil chamber 20, and the clutch mechanism 19 is set to the open state.
[0013]
In the automatic transmission configured as above, the excitation coil of the solenoid valve 11 is not energized when the lock-up is not operated. Accordingly, in this state, the ports 111 and 112 of the solenoid valve 11 communicate with each other, and "Pc = PL2", so that the valve element 130 of the spool valve 13 is set to the state shown in FIG. As a result, the secondary pressure PL2 acts on the off port 171 of the torque converter 12 via the ports 144 and 162, the control oil flows from the lock-up clutch control oil chamber 18 to the torque converter oil chamber 20, and the lock-up clutch mechanism 19 Is set to the open state, and lockup is deactivated.
[0014]
When the lock-up is operated, an exciting current is intermittently supplied to the solenoid of the solenoid valve 11 and duty control is performed, so that an arbitrary control pressure is set in a relation of “Pc <PL2”. You.
[0015]
Here, when the pressure Pc decreases, the spool thrust of the pressure PL2 acting on the hydraulic chamber 132 of the spool valve 13 becomes larger than the sum of the spool thrust of the pressure Pc acting on the hydraulic chamber 131 and the spool thrust of the spring 15. , The valve element 130 is moved to the left in the figure. Therefore, the ports 143 and 161 communicate with each other. As a result, the solenoid valve 11 is directly communicated with the lock-up clutch control oil chamber 18, and the control pressure Pc is supplied to the lock-up clutch control oil chamber 18. At the same time, the ports 144 and 163 of the spool valve 13 communicate with each other, and the pressure of the on port 172 of the torque converter 12 is set to the secondary pressure PL2.
[0016]
Therefore, in this state, the pressure in the clutch control oil chamber 18 is made equal to the control oil pressure Pc of the solenoid valve 11, and the lock-up clutch 19 applies the oil pressure PL 2 supplied to the torque converter oil chamber 20 and the clutch control oil chamber 18. In accordance with the difference between the supplied control pressure Pc and the control pressure Pc, a so-called slip control is performed in which the position is controlled to an intermediate position. The slip state of the lock-up clutch 19 is controlled based on the control pressure Pc controlled by the solenoid valve 11. Thereafter, the oil pressure in the control oil chamber 18 is controlled so that the lock-up clutch mechanism 19 is completely engaged by gradually decreasing the control oil pressure Pc of the solenoid valve 11.
[0017]
That is, this automatic transmission is configured by using one lock-up control solenoid valve 11 and one lock-up control spool valve 13. The switch 130 is controlled by a control oil pressure Pc set by the spring 15 and the solenoid valve 11. That is, only by controlling the control oil pressure Pc by controlling the solenoid valve 11, at the time of lock-up operation, switching of the spool valve 13 so that the lock-up clutch mechanism 19 is engaged, and furthermore, the lock-up clutch control oil chamber 18 The internal pressure can be adjusted, and lockup control in the torque converter 12 constituting the fluid coupling can be executed with high accuracy.
[0018]
Here, the energization control of the excitation coil of the solenoid valve 11 can be performed, for example, by a pulse signal having a specified frequency, and by changing the duty ratio of the pulse signal, the lock-up is performed at the time of lock-up setting. The control pressure of the clutch mechanism 19 acting on the clutch control oil chamber 18 is adjusted with high precision, and slip control in the clutch mechanism 19 is also enabled, so that the controllability and reliability of the lock-up control are improved.
[0019]
FIG. 2 shows the embodiment shown in FIG. 1 in the form of a hydraulic symbol. In this embodiment, a throttle is provided between the hydraulic chamber 132 of the spool valve 13 and the pressure source of the secondary pressure PL2. A parallel circuit of a check valve 22 is interposed together with 21. That is, the pulsation of the hydraulic pressure accompanying the operation of the solenoid valve 11 is suppressed by the throttle 21, and the responsiveness of the spool valve 13 is improved by the check valve 22 when the lock-up control shifts from the on state to the off state. . 23 is an oil cooler.
[0020]
In a normal torque converter, when the engagement control is performed (the state in which the second hydraulic path is formed), the lock-up control oil chamber 18 is substantially closed, and the flow rate of the oil controlled for this purpose is controlled. May be very small. Therefore, a relatively small solenoid valve can be used as the solenoid valve 11.
[0021]
【The invention's effect】
As described above, according to the lockup control device for an automatic transmission according to the present invention, the hydraulic pressure for controlling the clutch mechanism for setting the lockup is regulated by the control valve for the lockup control command. Accordingly, the direction switching valve is operated to switch, so that the configuration can be reliably simplified, and a small-sized and low-cost lock-up device can be provided. In addition, the hydraulic pressure of the clutch control oil chamber that controls the engagement of the clutch mechanism can be directly adjusted by the control valve, facilitating control with high lock-up accuracy.
[0022]
Further, when the control valve is configured by a duty-controllable solenoid valve, the throttle mechanism prevents a situation in which the direction switching valve vibrates due to pressure pulsation generated by the solenoid valve, which is generated by the intermittent control of the exciting current, In order to prevent the responsiveness of the direction switching valve from being deteriorated by the throttle mechanism, a check valve is arranged in parallel with the throttle mechanism. Therefore, the reliability as well as the responsiveness of the lockup control are effectively secured.
[Brief description of the drawings]
FIG. 1 is a configuration diagram for explaining a lock-up control device for an automatic transmission according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating another embodiment of the present invention.
[Explanation of symbols]
11: Solenoid valve (control valve), 12: Torque converter, 13: Spool valve (direction switching valve), 141 to 145, 161 to 163 ... Port, 15 ... Spring, 171, 172 ... Off and on port, 18 ... Clutch control oil chamber, 19: lock-up clutch mechanism, 20: torque converter hydraulic chamber, 21: throttle, 22: check valve.

Claims (5)

A fluid coupling that transmits rotational power from an input shaft to an output shaft via a fluid,
A lock-up clutch mechanism that bypasses the fluid coupling and couples the input shaft and the output shaft;
A control valve for controlling a control oil pressure for instructing switching between the engaged state and the released state of the clutch mechanism;
In the lock-up control device for an automatic transmission and a first state and a direction switching valve is switched to the second state based on a control hydraulic pressure that is controlled by the control valve,
In the fluid coupling, there are a first hydraulic chamber for applying a hydraulic pressure so as to release the lock-up clutch mechanism, and a second hydraulic chamber for applying a hydraulic pressure so as to fasten the lock-up clutch mechanism,
In the first state of the direction switching valve ,
A reference hydraulic pressure for controlling lockup of a pressure higher than that of the second hydraulic chamber is supplied to the first hydraulic chamber, and a first hydraulic path for releasing the lockup clutch mechanism is formed,
In the second state of the direction switching valve ,
A reference pressure for controlling the lock-up is supplied to a second hydraulic chamber in the fluid coupling, and a control pressure controlled by the control valve is supplied to a first hydraulic chamber in the fluid coupling, A second hydraulic path capable of engaging the lock-up clutch mechanism is formed,
In the second state of the direction switching valve, a control oil pressure set by the control valve is supplied to the second oil pressure path for fastening the lock-up clutch mechanism, and is set by the control valve. The control state of the clutch mechanism can be controlled by control hydraulic pressure, and the control valve sets a control hydraulic pressure that sets the direction switching valve to the first state in a non-operating state, and sets the control hydraulic pressure in an operating state of the control valve. used to set the control oil pressure to the direction switching valve and the second state, this second state, set by the control valve, the first hydraulic pressure in the second hydraulic path therefore the fluid coupling the chamber, the can lower control hydraulic pressure is supplied from the reference pressure for controlling the lock-up that will be supplied to the second hydraulic chamber in the fluid coupling, characterized in that to be able to control the engagement state of the lock-up Automatic change Machine lock-up control device. The direction switching valve is located at both ends of a valve body, and first and second hydraulic chambers are set, and the first hydraulic chamber is supplied with a control hydraulic pressure of a first pressure from the control valve. The hydraulic pressure of the second pressure set in the second hydraulic chamber is set so that the direction switching valve is set in the second state in a state where the first pressure is lower than the second pressure. The lock-up control device for an automatic transmission according to claim 1, wherein: The lock-up control device for an automatic transmission according to claim 1, wherein the control valve is a duty-controlled solenoid valve. 4. The lock-up control device for an automatic transmission according to claim 3, wherein a throttle is provided between the second hydraulic chamber and a hydraulic pressure source of the second pressure. 5. The lock-up control device for an automatic transmission according to claim 4, wherein a check valve is provided in a parallel relationship with the throttle.

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