JP2584686B2 - Hydraulic circuit structure of hydraulically controlled clutch transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hydraulic circuit structure of a hydraulically controlled clutch / transmission for an automobile.

<Prior Art> As shown in FIG. 4, a transmission TM which is shift / select controlled by a hydraulic control type clutch CL, a shift cylinder 41 and a select cylinder 42, and pressure control of discharge pressure oil by a variable displacement pump 9 are performed. The present applicant provides a mechanical automatic transmission controlled by a control unit such as an electromagnetic valve or an electromagnetic switching valve in Japanese Patent Application No. 1-92809. As shown in FIG. 5, the variable displacement pump 9 used in the prior art is provided with a rotor 96 rotatably provided with a vane 97 slidable in a radial direction in a housing 98, A cam ring 93 that surrounds the outer periphery and that the tip of the vane 97 slides against to form a pump chamber
The cam ring 93
Piston 90 which constantly pushes the housing 98 in the eccentric direction
This is a structure slidably provided in a cylinder 92 provided in the cylinder and pressed by a spring 91. 9a is a suction port, 9b is a discharge port, and 99 is a thrust roller.

<Problem to be Solved by the Invention> In the variable displacement pump 9 used in this conventional technique, when the discharge pressure increases and the force F applied to the cam ring 93 by the vane 97 increases, the spring 91 bends and the cam ring 93 moves. As a result, the discharge flow rate decreases. As shown in FIG. 6, the pump characteristics of the discharge flow rate and the pressure are as follows.
, And the B line is determined by the spring constant of the spring 91.

By the way, the hydraulic clutch CL and the transmission
The flow rate of the pressure oil required for controlling the TM is a constant flow rate as shown by C in FIG. 7, but the pressure E required for controlling the transmission TM is greater than the pressure D required for controlling the hydraulic clutch CL. And the working pressure must be adjusted to the pressure E required for controlling the higher transmission TM. Therefore, an unnecessary flow rate F occurs at the control pressure D of the hydraulic clutch CL, and the fuel saving effect is obtained. Less is.

<Means for Solving the Problems> The present invention has been made to improve the above-described problems, and has a characteristic configuration in which a clutch is provided in a clutch cover connected to a crankshaft of an engine. A hydraulic clutch that includes a disc and a piston that presses the clutch disc in the clutch connection direction, and that constantly circulates and supplies pressure oil that presses the piston in the clutch disengagement direction into the clutch cover; In a transmission that performs select operation, a variable displacement pump that sucks and discharges oil from an oil tank, a first circuit and a piston cylinder that communicate with a discharge side of the variable displacement pump and a pressure oil supply side into the clutch cover, and 2nd leading to shift / select cylinder
A pressure control solenoid valve for controlling the supply and discharge of pressure oil to and from the cylinder of the piston, and an electromagnetic switching valve for controlling pressure oil to the shift / select cylinder. The type pump has means for controlling the amount of eccentricity of the cam ring in addition to means for pushing the cam ring in the eccentric direction with a constant spring constant, and the eccentric amount control means includes a clutch controlled by the pressure control solenoid valve. It has a pump discharge pressure control circuit that guides a part of the control pressure oil and changes the pump characteristics.

<Operation> With the above configuration, the flow rate of the pressure oil required for controlling the clutch and the transmission is secured, and at the time of controlling the clutch, the pressure is reduced to the pressure required for controlling the clutch.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings. First
In the figure, CL is a hydraulic clutch. The hydraulic clutch CL includes a clutch disc 2 in a clutch cover 1 connected to a crankshaft (not shown) of the engine,
A piston 3 for pressing the clutch disk 2 in the clutch connection direction, and a space 4 in the clutch cover 1.
A first passage 5 for supplying pressure oil for constantly circulating supply of pressure oil to press the piston 3 in the clutch disengaging direction
And a second for supplying and discharging pressure oil to and from the cylinder 6 of the piston 3.
And a passage 7.

Reference numeral 8 denotes an oil tank in which a filter 18 is installed.

Reference numeral 9 denotes a variable displacement oil pump, and its inlet 9a
And the oil tank 8 are connected by a pipe 19.
A first circuit 11 communicating with the first passage 5 of the hydraulic clutch CL and a second circuit communicating with the second passage are provided at the discharge port 9b of the oil pump 9.
The circuit 12 is branched and connected.

The first circuit 11 includes a check valve 1 for controlling the pressure oil PC2 constantly supplied to the space in the clutch cover 1 to a constant pressure.
Three are provided.

On the other hand, the second circuit 12 includes an electromagnetic switching valve 40 for controlling the supply of the pressure oil PC3 to the shift and select cylinders 41 and 42, and the pressure oil PC to the cylinder 6 of the piston 3 of the hydraulic clutch CL.
And a pressure control solenoid valve 15 for controlling the supply and discharge of the pressure.

All the pressure oil discharged from the pressure control solenoid valve 15 is returned to the oil tank 8.

The space 4 in the clutch cover 1 and the oil tank 8
The filter 18 is connected via a pipe 16, and a throttle 17 is provided in the pipe 16. The variable displacement oil pump 9
As shown in FIG. 2, a rotor 96 provided with a vane 97 slidably in a radial direction in a housing 98 is rotatably provided,
A cam ring 93 surrounding the outer periphery of the rotor 96 and forming a pump chamber in which the tip of the vane 97 slides is provided so as to be eccentric with respect to the rotor 96, and a piston 90 which constantly pushes the cam ring 93 in the eccentric direction. Are slidable in a cylinder 92a provided in the housing 98, and a spring 9
Eccentric direction pushing means of the cam ring provided by pressing in 1,
A cylinder 92b having a pressure oil input port 100 is provided in a housing 98 on the opposite side, and a piston 94 is pressed into the cylinder 92b by a spring 95 and abuts on the cam ring 93.
And a cam ring eccentricity control means.

Next, the operation of the above configuration will be described. The pressure oil discharged from the oil pump 9 flows to the first circuit 11 and the second circuit 12,
The pressure oil flowing through the circuit 11 is controlled to a constant pressure by the check valve 13 and the throttle 17, and the pressure oil PC2 controlled to the constant pressure is supplied from the first passage 5 into the space 4 to disengage the piston 3 from the clutch. Press And the pressure oil PC2 in the space 4 is
It is returned to the oil tank 8 via 6.

That is, the hydraulic clutch CL is connected to the pressure oil PC passing through the first circuit 11.
2, the clutch is always biased to the disengaged state. On the other hand, the pressure oil flowing to the second circuit 12 is transmitted to the transmission TM
When controlling the solenoid, the electromagnetic switching valve 40 is operated by a command signal from a controller (not shown),
Pressure oil PC3 is supplied to 1, 42. At this time, the hydraulic clutch
Since the supply of the pressure oil PC1 to the CL is shut off, the pressure oil PC1 is not introduced into the cylinder 92b of the oil pump 9.

Therefore, the cam ring 93 of the oil pump 9 is
Pushed in the eccentric direction by the spring 91 on the a side, the pump characteristics shown by the B1 line in FIG.
Is the discharge pressure of the pressure E required for the control.

The connection of the hydraulic clutch CL after the control of the transmission TM is performed by applying a command current from a controller (not shown) to the pressure control solenoid valve 15 and applying a pressure oil PC1 having a pressure higher than the pressure oil PC2 to the second according to the applied electromagnetic value. The clutch is supplied to the passage 7, and the piston 3 is advanced to control the connection of the clutch gently or early according to the running state or the like.

When the clutch is engaged, the pressure oil PC1 is introduced into the cylinder 92b of the oil pump 9 from the pipe 51, and the piston 94 pushes back the cam ring 93 to reduce the eccentricity. As a result, the pump characteristic changes to the line B2 in FIG. 3, and the discharge pressure of the oil pump 9 drops to the pressure D required for controlling the hydraulic clutch CL. The pressure E required for controlling the transmission TM and the pressure D required for controlling the hydraulic clutch CL controlled to be lower than the pressure E are, as shown in FIG.
Control is performed after securing the flow rate C required for controlling the CL.

<Effects of the Invention> As described above, according to the present invention, a clutch disc is provided in a clutch cover connected to a crankshaft of an engine, and a piston for pressing the clutch disc in a clutch connection direction is provided. A hydraulic pump that constantly circulates and supplies pressure oil that presses the piston in the clutch disengagement direction; and a variable displacement pump that sucks and discharges oil from an oil tank in a transmission that performs shift / select operation with the pressure oil. A first circuit communicating with a discharge side of the variable displacement pump and a pressure oil supply side into the clutch cover; and a second circuit communicating with a piston cylinder and a shift / select cylinder. A pressure control solenoid valve that controls the supply and discharge of pressure oil to and from the cylinder and a shift select series An electromagnetic switching valve for controlling oil pressure to the cylinder, the variable displacement pump has means for controlling the amount of eccentricity of the cam ring in addition to means for pushing the cam ring in an eccentric direction with a constant spring constant. The eccentricity control means is provided with a pump discharge pressure control circuit that guides a part of the clutch control pressure oil controlled by the pressure control solenoid valve and changes a pump characteristic. Since the eccentricity of the cam ring of the variable displacement oil pump is controlled by the hydraulic pressure of the operating pressure oil PC1 of the hydraulic clutch, and the discharge pressure of the pressure required for the hydraulic clutch is controlled to be lower than the pressure required for controlling the transmission, There is no waste in the flow rate of the pressure oil during the connection operation of the hydraulic clutch, and the driving force of the variable displacement oil pump is more labor-saving than before.
Improve the fuel efficiency of the engine.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, in which a control circuit is combined with a hydraulic clutch, FIG. 2 is a sectional view of a variable displacement oil pump used in the present invention, and FIG. 3 is a variable displacement oil pump in the present invention. FIG. 4 is a sectional side view of a hydraulic control type clutch / transmission, FIG. 5 is a sectional view of a conventional variable displacement oil pump, and FIG. 6 is a pump of the conventional variable displacement oil pump. FIG. 7 is a characteristic diagram showing the waste of the pressure oil flow when the clutch and transmission are operated by the conventional variable displacement oil pump. 1 ... clutch cover, 2 ... clutch disc, 3 ...
... Piston, 4 ... Space, 5 ... First passage, 6 ... Cylinder, 7 ... Second passage, 8 ... Oil tank, 9 ... Oil pump, 11 ... First circuit, 12 ... 2 circuits, 13 ...
Check valve, 15: Pressure control solenoid valve, 40: Solenoid switching valve, 90: Piston, 91: Spring, 92a, 92b ...
Cylinder, 94… Piston, 95… Spring, 100…
… Pressure oil input port.

Claims (1)

(57) [Claims] A clutch cover connected to a crankshaft of an engine includes a clutch disc and a piston for pressing the clutch disc in a clutch connection direction, and presses the piston in the clutch cover in a clutch disengagement direction. A variable displacement pump that sucks and discharges oil from an oil tank in a hydraulic clutch that constantly circulates and supplies pressure oil to be pumped, and a transmission that performs shift / select operation by the pressure oil, and a discharge side of the variable displacement pump and A first circuit communicating with a pressure oil supply side into the clutch cover, and a second circuit communicating with a piston cylinder and a shift / select cylinder, wherein the second circuit controls supply and discharge of pressure oil to and from the piston cylinder Pressure control solenoid valve and electromagnetic switching to control pressure oil to shift / select cylinder The variable displacement pump has means for controlling the amount of eccentricity of the cam ring in addition to means for pushing the cam ring in an eccentric direction with a constant spring constant. A hydraulic circuit structure of a hydraulically controlled clutch transmission, comprising: a pump discharge pressure control circuit that guides a part of clutch control pressure oil controlled by an electromagnetic valve to change pump characteristics.