JPS6124582B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for controlling the operation of a clutch for a torque converter in a transmission for an automobile or other vehicle.

Conventionally, this type of device includes a clutch that operates to mechanically connect an input side and an output side of a fluid torque converter that connects a vehicle transmission with a plurality of selectively established transmission systems to an engine. a clutch control valve that operates the clutch at a predetermined vehicle speed or higher by being controlled by a vehicle speed signal pressure corresponding to the vehicle speed; and a transmission system signal that is generated when a predetermined transmission system, for example, a transmission system for the highest gear, is established. and a vehicle speed signal control valve that is actuated by pressure and allows input of the vehicle speed signal pressure to the clutch control valve, so that the clutch is operated at a predetermined vehicle speed or higher when the transmission system of the highest speed gear is established. It is known that mechanical torque transmission through the clutch prevents slippage in the fluid torque converter, enabling efficient torque transmission during high-speed cruising and improving fuel efficiency. (See USP 3,252,352 specification), when the clutch is activated and the accelerator pedal is released to start decelerating, the engine is reversely driven from the drive wheels through the clutch in the initial stage, suppressing the longitudinal shaking of the vehicle body. This is accompanied by the inconvenience of poor riding comfort.

An object of the present invention is to provide a device that eliminates such inconveniences, and includes a fluid torque converter that connects a vehicle transmission with a plurality of selectively established transmission systems to an engine. A first control valve for controlling the clutch is provided with a clutch that operates to mechanically connect the input side and the output side, and is controlled by a vehicle speed signal pressure corresponding to the vehicle speed to operate the clutch at a predetermined vehicle speed or higher. and a second control valve for vehicle speed signal control that operates with a transmission system signal pressure generated when a predetermined transmission system is established and allows input of the vehicle speed signal pressure to the first control valve, The clutch is configured to operate at a speed equal to or higher than the predetermined vehicle speed when the predetermined transmission system is established, and the clutch is actuated when the throttle opening of the engine is below the predetermined opening. The present invention is characterized in that it includes a transmission system signal cutoff device that cuts off input of the transmission system signal pressure.

The invention will now be explained with reference to illustrated embodiments.

In FIG. 1, 1 indicates a vehicle transmission, and the transmission 1
is a transmission system for forward speeds 1 to 3 between an input shaft 1a connected to the crankshaft 3 of the engine 2 via a fluid torque converter 4 and an output shaft 1b connected to the drive wheels 5 of the vehicle. Systems G1, G2, G3,
Reverse transmission system GR, each forward transmission system G
The hydraulic clutches C1, C2, and C3 for the first to third speeds are intervened in the transmission systems G1, G2, and G3, and the respective transmission systems G1 and G3 are engaged by engaging the hydraulic clutches C1, C2, and C3.
2, G3 are selectively established, and the reverse transmission system GR shares the 2nd speed transmission system G2 and the 2nd speed hydraulic clutch C2, and both transmission systems G2, GR
In the diagram of the selector gear 6, which selects the , the selection is established by switching to the right reverse side. In the drawing, 7 is a one-way clutch that intervenes in the first-speed transmission system G1, and operates to allow over-rotation of the output shaft 1b.

Each of the hydraulic clutches C1, C2, and C3 has its oil connection and discharge controlled by, for example, a hydraulic circuit shown in FIG. "P", "R" for reverse, "N" for neutral, "D" for automatic transmission,
A manual valve 9 that can be freely switched to five positions of "2" for holding second gear, a shift valve 10 that is switched depending on the vehicle speed and throttle opening, and a forward/reverse switch that connects the aforementioned selector gear 6. servo valve 11, and when the manual valve 9 is in the "D" position, the hydraulic power source 8
A first oil passage L1 for oil supply leading to the shift valve 10 is connected to a second oil passage L2 leading to the shift valve 10, and is connected to the first speed hydraulic clutch C1 via a third oil passage L3 branched from the second oil passage L2. , oil is supplied to each of the second and third speed hydraulic clutches C2 and C3 through the shift valve 10. Here, the shift valve 10 is connected to the intermediate fourth oil passage L.
It consists of a first valve 10-1 for 1st-2nd speed shifting on the upstream side and a second valve 10-2 for 2nd-3rd speed shifting on the downstream side, which are connected to each other via 4. Each valve 1
A governor valve 12 is installed at one end of 0-1, 10-2, that is, at the right end.
A governor pressure corresponding to the vehicle speed is applied to the left end, and a throttle pressure corresponding to the throttle opening from the first throttle valve 13 is applied to the left end. The second oil passage L2 is connected to the fifth oil passage L5 on the outflow side of the second valve 10-2 via the fourth oil passage L4, and the second oil passage L2 is connected to the fifth oil passage L5 on the outflow side of the second valve 10-2. At the "D" position, the second-speed hydraulic clutch C2 is refueled via the sixth oil passage L6 connected to the fifth oil passage L5, and when the vehicle speed further increases, the second shift valve 10-2 shifts to the right two-speed hydraulic clutch C2. The fourth oil passage L4 moves from the first gear position to the third gear position on the left side, and the seventh oil passage L4 connects from the fifth oil passage L5 to the third gear hydraulic clutch C3.
A 3-speed hydraulic clutch C3 is connected to the oil passage L7.
refueling was done.

The torque converter 4 connects the input shaft of the transmission 1 to an internal space 16 surrounded by an input case 14 on one side connected to the crankshaft 3 of the engine 2 and a pump impeller 15 on the other side connected thereto. 1a, and a stator wheel 18 between the two blade wheels 15, 17. The torque converter 4 has an input case 14 on the input side and a turbine wheel 17 on the output side, for example. It is equipped with a clutch 19 that can be mechanically connected and disconnected, and when the clutch 19 is switched, the blade wheels 15, 17, 1
Fluid torque transmission by internal fluid circulation between 8 and 8;
When the clutch 19 is engaged, a mechanical torque is transmitted through the clutch 19. Various types of clutch 19 are used, such as a multi-disc friction clutch or a one-way clutch, but the one shown is a single-disc friction clutch, and the clutch plate 19a is connected to the input case 1.
The clutch plate 19a and the input case 1 are disposed movably in the axial direction in the gap between the clutch plate 19a and the turbine wheel 17.
4, the clutch plate 19a is separated from the input case 14, and when oil is drained from the oil chamber 20, the clutch plate 19a is separated from the input case 14. The input case 14 is pressed by the internal pressure of the input case 16 and is frictionally engaged with the input case 14. Switching control is performed by a first control valve 21 for clutch control which is controlled by pressure. The control valve 21 connects an eighth oil passage L8 that leads pressure oil from the hydraulic power source 8 via the regulator valve 22 to a ninth oil passage L9 that leads to the oil chamber 20 to supply oil into the oil chamber 20. the left clutch disengagement position (position shown),
The ninth oil passage L9 is connected to the atmosphere release port 23 and can be switched to the right clutch connection position where oil is drained from the oil chamber 20, and the governor pressure moves the control valve 21 to the clutch connection position. When the vehicle speed exceeds a predetermined speed, the first control valve 21 is switched to the clutch engagement position to apply the engagement action to the clutch 19.

In addition, at this connection position, pressure oil is supplied to the 10th oil passage L10 connected to the internal cavity 16 via the 8th oil passage L8, and the check valve 24 interposed in the oil drainage passage LD of the cavity 16 closes the cavity. 16 is set to a relatively high pressure, and at the cutting position, oil is supplied to the cavity 16 through the oil chamber 20, and the 10th oil passage L1
11 oil passage L1 with orifice 25 interposed from 0
1, and the internal pressure of the gap 16 was set to a relatively low pressure.

Further, the throttle pressure from the first throttle valve 13 is applied to the control valve 21 in opposition to the governor pressure, so that as the throttle opening increases, switching to the clutch connection position is performed at a higher speed. In addition, the 3rd speed transmission system G3 is connected to the 12th oil passage L12 which leads the governor pressure to the control valve 21 so that the control valve 21 is switched to the clutch connection position only when the 3rd speed transmission system G3 is established. For example, the 3rd speed pressure generated in the 7th oil passage L7 connected to the 3rd speed hydraulic clutch C3 is transferred to the 7th oil passage L.
A second control valve 26 for vehicle speed signal control, which is inputted and opened via a thirteenth oil passage L13 branched from No. 7, is intervened.

Although the above is not particularly different from the conventional type described above, according to the present invention, a transmission system signal cut-off device 27 that operates when the throttle opening of the engine 2 is less than a predetermined opening is provided, and the cut-off device 27, the input of the third speed pressure to the second control valve 26 is cut off.

In the one shown in the second figure, the shutoff device 27 is
The second throttle valve 30 is provided in order to control the back pressure of the pressure buffer accumulators 28 and 29 of the hydraulic clutches C2 and C3 in accordance with the throttle opening degree. and interposing the valve in the thirteenth oil passage L13,
Through the groove 31a on the outer periphery of the plunger 31,
13 The upstream and downstream sides of the oil passage L13 are communicated, and when the plunger 31 moves to the right in the drawing as the throttle opening decreases, the groove 31
In this embodiment, the communication through a is cut off, and the input of the third speed pressure to the second control valve 26 is cut off. However, the present invention is not limited to this. The shutoff device 27 may be constructed by interposing a shutoff valve in the thirteenth oil passage L13 to apply the throttle pressure to the opening side.

Next, to explain its operation, when establishing the 1st speed transmission system G1 by supplying oil to the 1st speed hydraulic clutch C1, and when establishing the 2nd speed transmission system G2 by supplying oil to the 2nd speed hydraulic clutch C2, the second control valve 26 is closed and the input of governor pressure to the first control valve 21 is cut off,
The first control valve 21 is always in the clutch disengaged position, and the clutch 19 is maintained in the disengaged state, so that smooth starting acceleration is obtained by utilizing the torque amplification function by fluid torque transmission. Then, due to the increase in vehicle speed, 3
When the speed hydraulic clutch C3 is refueled and the 3rd speed transmission system G3 is established, the 3rd speed pressure is input to the second control valve 26 and the valve 26 is is opened, and the governor pressure is inputted to the first control valve 21 through this to switch the valve 21 to the clutch connection position at a predetermined vehicle speed or higher, and the clutch 19 is operated. When the accelerator pedal is returned to decelerate, the throttle opening decreases to the predetermined opening, and the shutoff valve 27, which serves as a transmission system signal cutoff device, is closed, and the second
The input to the control valve 26 is cut off, causing the valve 26 to close, and the input of governor pressure to the first control valve 21 is cut off, causing the valve 21 to return to the clutch disengaged position, causing the clutch 19 to become inoperative. Therefore, the reverse driving force from the drive wheel 5 side is absorbed by slippage in the fluid torque converter 4 and is prevented from being transmitted to the engine 2.

Note that even if a cutoff valve that is closed when the throttle opening is below a predetermined throttle opening is inserted in series with the second control valve 26 in the 12th oil passage L12 that leads the governor pressure to the first control valve 21, the same operation as described above will occur. However, according to this, the governor pressure decreases due to leakage in the two valves, causing a deviation from the normal governor pressure in the pressure input to the first control valve 21, and the pressure of the first control valve 21 decreases. However, according to the present invention, since the second control valve 26 is only intervened in the twelfth oil passage L12 as described above, the pressure drop due to leakage of governor pressure is avoided. is suppressed, and accurate operation of the first control valve 21 is obtained.

Further, in the above embodiment, a fully automatic type transmission 1 is used, but the present invention can be similarly applied to a semi-automatic type transmission.

As described above, according to the present invention, the input of the transmission system signal pressure to the second control valve that controls the input of the vehicle speed signal pressure to the first control valve for clutch control is set to a predetermined throttle opening or less. The device is equipped with a transmission system signal cutoff device that stops the clutch operation below the predetermined opening degree, and prevents the transmission of reverse driving force to the engine side during deceleration through the clutch. The inconveniences of the conventional type are solved, and furthermore, the vehicle speed signal pressure is inputted to the first control valve through one second control valve without going through a plurality of valves, suppressing pressure drop due to leakage. This has the effect of providing accurate clutch operation control in response to vehicle speed using one control valve.

[Brief explanation of the drawing]

FIG. 1 is a diagram of an example of a vehicle transmission to which the device of the present invention is applied, FIG. 2 is a circuit diagram of an example of the device of the present invention, and FIG. 3 is a circuit diagram of a modification thereof. DESCRIPTION OF SYMBOLS 1... Vehicle transmission, 2... Engine, 4... Fluid torque converter, 19... Clutch, 21... First control valve, 26... Second control valve, 27... Transmission system signal cutoff device.

Claims (1)

[Claims] 1. A fluid torque converter that connects a vehicle transmission with a plurality of selectively established transmission systems to an engine is provided with a clutch that operates to mechanically connect the input side and the output side, and also has a clutch that operates to mechanically connect the input side and the output side. a first control valve for clutch control which is controlled by a corresponding vehicle speed signal pressure to operate the clutch at a predetermined vehicle speed or higher; and a second control valve for vehicle speed signal control that allows input of the vehicle speed signal pressure to the first control valve, so that the clutch is operated at a speed equal to or higher than the predetermined vehicle speed when the predetermined transmission system is established. The invention is characterized by comprising a transmission system signal cutoff device that operates when the throttle opening of the engine is below a predetermined opening and cuts off input of the transmission system signal pressure to the second control valve. An operation control device for a torque converter clutch in a vehicle transmission.