JPS6148025B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for controlling the operation of a clutch for a fluid torque converter in a vehicle transmission comprising a fluid torque converter and an automatically variable auxiliary transmission.

Conventionally, this type of device is disclosed, for example in US Pat. No. 3,252,352, in which a hydraulic torque converter is provided with a clutch that operates to mechanically connect the input side and the output side of the converter. It is known that the clutch is operated at a predetermined vehicle speed or higher at the time of establishment to achieve efficient torque transmission that prevents slippage in the fluid torque converter. In order to ensure that An on-off valve that is opened is interposed to prevent the clutch from operating when a transmission system at a lower speed than the highest speed transmission system is established. In this case, in order to simplify the configuration, it is conceivable to set the predetermined vehicle speed of the control valve above the minimum vehicle speed in the vehicle speed range in which the highest gear transmission system is established, and omit the on-off valve. The machine establishes the highest speed transmission system from an automatic transmission state in which multiple stages of transmission systems, including the highest speed transmission system, are automatically switched by switching from the automatic transmission position of the manually operated valve that controls its operation. Generally, the manually operated valve is configured to be able to switch freely to the state where the transmission system for the lower speed gear is established. In this case, a downshift occurs when the clutch is operated, resulting in the disadvantage that the shift shock becomes large.

An object of the present invention is to provide a device that can prevent the occurrence of such a shift shock without using a special valve such as an on-off valve. The predetermined vehicle speed to be applied is set to be higher than the lowest vehicle speed in the vehicle speed range in which the highest gear transmission system is established, and the governor pressure is input to the control valve at the automatic shift position via the manually operated valve. Features. Next, the present invention will be explained with reference to the illustrated embodiments.

In Figure 1, 1 is the engine, 2 is the drive wheel of the vehicle, and 3
shows a vehicle transmission that connects the engine 1 and the drive wheels 2, and the transmission 3 is composed of a fluid torque converter 4 and an automatic transmission type auxiliary transmission 5.

The auxiliary transmission 5 is configured to shift, for example, three forward speeds and one reverse speed. 1st to 3rd speed transmission system G1, G
2, G3, and a reverse transmission system GR, each hydraulic clutch C1, C2, C3 of 1st to 3rd speed intervenes in each forward transmission system G1, G2, G3, and each hydraulic clutch C1, C2 . In the diagram of selector gear 6 that selects system G2 and GR, it is established by switching to the right reverse side. In the drawing, 7 is a one-way clutch interposed in the speed transmission system G1, which operates to allow over-rotation of the driven shaft 5b.

The oil supply and drainage of each of the hydraulic clutches C1, C2, and C3 is controlled, for example, by a hydraulic circuit shown in FIG. ``P'' for reverse, ``N'' for neutral, ``D'' for automatic shift, and ``2'' for holding second gear. and a servo valve 11 for forward/reverse switching that connects the selector gear 6 described above, and in the "D" position of the operation valve 9,
A first oil passage L1 leading to the hydraulic power source 8 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 the second and third speed hydraulic clutches C2 and C3 via the shift valve 10. Here, the shift valve 10 includes a first valve 10-1 for 1st-2nd speed shifting on the upstream side and a 2nd-3rd speed shifting valve 10-1 on the downstream side, which are connected to each other via an intermediate fourth oil passage L4. A governor valve 1 is provided at one end, that is, the right end of each of the valves 10-1 and 10-2.
A governor pressure corresponding to the vehicle speed from 2 and a throttle pressure corresponding to the engine throttle opening from the first throttle valve 13 are applied to the left end, and as the vehicle speed increases, the first valve 10-1 first moves to the right side. 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 manual operation is performed. At the "D" position of the valve 9, oil is supplied to the second-speed hydraulic clutch C2 via the sixth oil passage L6 connected to the fifth oil passage L5,
When the vehicle speed further increases, the second shift valve 10-2 moves from the second gear position on the right side to the third gear position on the left side, and shifts to the fourth gear position.
Oil passage L4 connects from fifth oil passage L5 to third-speed hydraulic clutch C
3 to supply oil to the 3rd speed hydraulic clutch C3, and in accordance with the shift characteristics shown in FIG. 3, the 1st to 3rd speed transmission systems G1, G2 , G3 is now automatically switched. In Figure 3, line a is the shift line from 1st gear to 2nd gear,
Line b shows the shift line from 2nd speed to 3rd speed.

When the manually operated valve 9 is switched from the "D" position to the "2" position, communication between the first oil passage L1 and the second oil passage L2 is cut off, and the first oil passage L1 connects the servo valve 11 with the first oil passage L1. The eighth oil passage L8 on the outflow side is connected to the sixth oil passage L6 leading to the second-speed hydraulic clutch C2, and the second-speed transmission system G2 is also established in the area where the third-speed transmission system G3 is established. .

The fluid torque converter 4 has an input case 1 connected to the crankshaft 1a of the engine 1.
4 and the pump impeller 15 on the other side connected thereto, a turbine impeller 17 connected to the drive shaft 5a of the auxiliary transmission 5 and both impellers 1
5 and 17, and a clutch 19 that can be freely engaged and disconnected to mechanically connect the input case 14 on the input side of the torque converter 4 and the turbine impeller 17 on the output side, for example. When the clutch 19 is disengaged, fluid torque is transmitted by circulating the internal fluid between the impellers 15, 17, and 18, and when the clutch 19 is connected, mechanical torque is transmitted via the clutch 19. is configured so that it is given.

The clutch 19 can be of various types, such as a multi-plate friction clutch or a one-way clutch, but the one shown is a single-plate friction clutch, and the clutch plate 19a is connected to the gap between the input case 14 and the turbine wheel 17. This is connected to the turbine wheel 17 via the damper spring 19b, and the oil chamber 20 between the clutch plate 19a and the input case 14 is supplied with oil. In the disconnected state in which the clutch plate 19a is separated from the input case 14 and due to the oil discharged from the oil chamber 20, the clutch plate 19a is pressed by the internal pressure of the internal gap 16 and is frictionally engaged with the input case 14. The oil supply and discharge to the oil chamber 20 is controlled by a control valve 21 which is controlled by the governor pressure from the governor valve 12 which responds to the vehicle speed.

The control valve 21 connects a ninth oil passage L9 that guides pressure oil from the oil pressure source 8 via the regulator valve 22 to the oil chamber 2.
The right clutch disconnection position (position shown in the figure) connects to the 10th oil passage L10 leading to the 9th oil passage L10 to supply oil to the oil chamber 20, and the 11th oil passage L9 connects the 9th oil passage L9 to the internal cavity 16.
It is connected to the oil passage L11 to supply oil to the gap 16 and to the oil passage L11.
The control valve 2 can be freely switched to the left clutch connection position where the oil passage L10 is connected to the atmosphere opening boat 23 and the oil is drained from the oil chamber 20.
1 to the clutch engagement position side, so that at a predetermined vehicle speed or higher, the control valve 21 is switched to the clutch engagement position and the clutch 19 is engaged; Accordingly, the 3rd speed transmission system G3 of the highest gear is set at a speed higher than the lowest vehicle speed in the vehicle speed range in which the 3rd speed transmission system G3 is established.
The clutch 19 is operated at a predetermined vehicle speed or higher when the speed transmission system G3 is established.

In the illustrated example, since the minimum vehicle speed increases as the throttle opening of the engine increases, as shown by line b in FIG. The throttle pressure from 13 is applied to the 12th oil passage L12 which inputs the governor pressure to the control valve 21, so that the switching to the clutch connection position is performed at a higher speed as the throttle opening increases. Accumulator 2 for pressure buffering of each hydraulic clutch C2, C3 of 3rd speed
A second throttle valve 26 that regulates the back pressure of 4 and 25.
A cutoff valve 27 is provided which closes when the throttle opening of the engine is less than a predetermined opening θ ₀ under the influence of the throttle pressure from the engine, thereby preventing the clutch 19 from operating during deceleration. The clutch 19 can operate within a range of .
Further, according to the present invention, governor pressure is inputted to the control valve 21 via the manually operated valve 9 at its automatic shift position, that is, the "D" position, which will be described in further detail in addition to that shown in the drawings. Then, a groove 9a connecting the upstream side and the downstream side of the twelfth oil passage L12 is formed in the manual operation valve 9 at the "D" position, and the twelfth oil passage L12 is connected through the groove 9a at the "D" position. The oil passage L12 is communicated so that the governor pressure is input to the control valve 21, and when the manual operation valve 9 is switched to the "2" position, the communication of the 12th oil passage L12 is disconnected. The downstream portion of the control valve 21 connected to the control valve 21 is opened to the atmosphere through a drain hole 9b formed in the manually operated valve 9.

In the drawing, 28 is the fluid torque converter 4 described above.
A check valve 29 is interposed in the first oil drain path LD1 connected to the internal cavity 16, and 29 is a second oil drain connected to the 11th oil path L11 connected to the internal cavity 16 at the clutch disconnection position of the control valve 21. An orifice interposed in the passage LD2 is shown, and when the clutch 19 is connected, the check valve 28 maintains the internal pressure of the internal cavity 16 at a relatively high pressure, and when the clutch 19 is disconnected, the check valve 28 maintains the internal pressure of the internal gap 16 at a relatively high pressure. The internal pressure of the internal cavity 16 is reduced to the orifice 2.
9 to maintain a relatively low pressure.
Next, to explain its operation, when the manual operation valve 9 is set to the "D" position, the 12th oil passage L12 is opened as described above.
is communicated and governor pressure is input to the control valve 21,
At a predetermined vehicle speed or higher when the third-speed transmission system G3 is established, the control valve 21 is switched to the clutch connection position and the clutch 19 is operated, and mechanical torque transmission through the clutch 19 prevents slippage in the fluid torque converter 4. This results in efficient torque transmission that prevents this.

When the operation valve 9 is switched to the "2" position in this state, if the 12th oil passage L12 is kept in communication at all times, a downshift from 3rd gear to 2nd gear will occur under the operation of the clutch 19, resulting in a shift shock. becomes larger, but
According to the present invention, when the operation valve 9 is switched to the "2" position, the communication with the twelfth oil passage L12 is cut off, so that the governor pressure is no longer input to the control valve 21, and the control valve 21 is moved to the clutch disconnection position. Returned to Clutch 1
9 is disconnected, and the shift shock is absorbed by the slip caused by the fluid torque transmission of the fluid torque converter 4.
A smooth downshift is performed.

As described above, according to the present invention, the control valve is operated and the clutch is operated at a predetermined vehicle speed set above the minimum vehicle speed in the vehicle speed range in which the highest gear transmission system is established. A special opening/closing valve for inputting the governor pressure to the control valve in conjunction with the establishment of the transmission system is no longer required, and the governor pressure is input to the control valve at the automatic shift position via the manually operated valve. Therefore, even if such an on-off valve is omitted,
When the control valve is switched from the automatic shift position, the input of governor pressure to the control valve is cut off and the clutch is disengaged, which has the effect of preventing the occurrence of shift shock.

[Brief explanation of the drawing]

FIG. 1 is a diagram of an example of a vehicle transmission to which the present invention is applied, FIG. 2 is a hydraulic circuit diagram thereof, and FIG. 3 is a diagram showing its transmission characteristics and the operating range of the clutch. 3... Vehicle transmission, 4... Fluid torque converter, 5... Auxiliary transmission, G1, G2, G3...
Transmission system, 9...manual operation valve, 19...clutch.

Claims (1)

[Claims] 1. A vehicle transmission is composed of a fluid torque converter and an automatic transmission type auxiliary transmission, and the auxiliary transmission is changed from the automatic transmission position to the highest gear position by switching from the automatic transmission position of a manually operated valve that controls the operation of the auxiliary transmission. It is possible to freely switch from an automatic shift state in which multiple stages of transmission systems including the transmission system are automatically switched to a state in which establishment of the transmission system of the highest speed stage is prevented and a transmission system of a lower speed stage is established, and A torque converter is provided with a clutch that operates to mechanically connect its input side and output side, and the clutch is operated at a predetermined vehicle speed or higher by a control valve controlled by a governor pressure depending on the vehicle speed. In this step, the predetermined vehicle speed is set to be equal to or higher than the lowest vehicle speed in the vehicle speed range in which the highest gear transmission system is established, and the governor pressure is input to the control valve at the automatic shift position via the manual operation valve. An operation control device for a clutch for a fluid torque converter in a vehicle transmission, characterized in that: