JPH0369826A - Hydraulic clutch structure for continuously variable transmission - Google Patents

Abstract

PURPOSE:To enhance operational facility of adjustment, simplify control of a clutch pressure, and reduce a cost by varying the thickness of a snap ring for fixing an end plate in a housing sub member so as to keep the creep state of a hydraulic clutch constant. CONSTITUTION:A housing sub member 84 is fitted to a retractor plate 100 by a first snap ring 106. A piston 98 is fitted to the retractor plate 100 by a second snap ring 108. The housing sub member 84 is fitted to an end plate 90 by a third snap ring 110. In the third snap ring 110 for fixing the end plate 90 in the housing sub member 84, a change in movement amount of a pressure plate 86 to the end plate 90 can vary a touch off pressure value, thereby varying the thickness of the third snap ring 110 so as to keep a creep state of a hydraulic starting clutch 62 substantially constant.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a hydraulic clutch structure for a continuously variable transmission, and in particular, to changing the amount of movement of a pressure plate to an end plate to change a touch-off pressure value. The present invention relates to a hydraulic clutch structure for a continuously variable transmission that allows a creep state to appear substantially constant.

[Prior Art] In a vehicle, a transmission is interposed between an internal combustion engine and drive wheels. This transmission changes the driving force and running speed of the drive wheels in accordance with the widely varying running conditions of the vehicle, thereby allowing the internal combustion engine to fully demonstrate its performance. The transmission includes a fixed pulley part fixed to the rotating shaft and a movable pulley part attached to the rotating shaft so as to be able to approach and separate from the fixed pulley part. There is a continuously variable transmission that transmits power by increasing or decreasing the rotation radius of a belt wrapped around a pulley by increasing or decreasing the width of the groove, thereby changing the speed ratio (belt ratio).

In addition, the difference between the surface hardness of the compression coil spring of the direct coupling clutch disclosed in Japanese Patent Publication No. 63-63789 and the surface hardness of the compression coil spring holding part and the engaging part is set to 200 or less in terms of Vickers hardness, and the direct coupling clutch is Durability is significantly improved.

[Problems to be Solved by the Invention] By the way, in the conventional hydraulic clutch structure of a continuously variable transmission, when the clutch pressure is gradually increased from O, the clutch pressure reaches point A as shown in FIG. When this happens, the piston begins to operate against the biasing force of the Belleville spring. When the clutch pressure is further increased and reaches point B, the pressure plate pressed by the piston comes into close contact with the end plate via the friction plate.

However, when the clutch housing on the input rotation side is rotating and the clutch pressure reaches point B, the friction plate on the output rotation side starts rotating and the hydraulic clutch starts transmitting torque. be.

The value at the point B is called the touch-off pressure value of the hydraulic clutch, and the movable full stroke amount, which is the amount of movement of the pressure plate, is called the pack clearance.

In actual vehicles, by controlling the clutch pressure to a touch-off pressure value, a creep state occurs in which a weak torque is transmitted to the drive wheels when the shift position is in drive (D) or reverse (R) while stopped. is made to appear.

At this time, since the touch-off pressure value of the hydraulic clutch differs depending on each individual, when the clutch pressure is controlled to a certain constant value, the strength of the creep state is not approximately constant, and there are various holes depending on each individual. It is what it is.

In addition, if the pack clearance is set narrowly, it is likely to cause dragging or seizure when the clutch is idling, so adjustment is required, but the adjustment of the pack clearance does not need to be as severe as the touch-off pressure value. It is something.

Therefore, in order to keep the creep state approximately constant, it is possible to adjust the touch-off pressure value of each hydraulic clutch to a constant value, or to perform closed-loop control of clutch pressure control during the creep state using feedback such as output torque. It will be done.

However, in the former case, Pre1. This can be done by adjusting the dimensional tolerance in the thickness direction of the snap plate, Frixilon plate, or end plate, or the position of the snap ring groove in the housing sub-member, but it takes a lot of time to adjust, and it is difficult to work. This has the disadvantage that it is disadvantageous in practice.

In addition, in the latter case, by performing closed-loop control during the creep state, unnecessary parts such as detection sensors must be installed, and the control program must be rewritten, making the structure complicated. There is a disadvantage that the cost is large and it is economically disadvantageous.

[Object of the Invention] Therefore, an object of the present invention is to form a hydraulic clutch by arranging a pressure plate, a Belleville spring, and an end plate in a housing sub-member, and to eliminate the above-mentioned disadvantages. The snap ring that fixes the end plate to the housing sub-member is configured to have a different thickness in order to change the touch-off pressure value by changing the amount of movement up to the end plate and to maintain a substantially constant creep state of the hydraulic clutch. This makes it possible to adjust the touch-off pressure value and keep the creep state approximately constant when installed in an actual vehicle, improving adjustment workability and simplifying clutch pressure control, while also reducing costs without complicating the configuration. The purpose of this invention is to realize a hydraulic clutch structure for a continuously variable transmission that can be used as a continuous variable transmission.

[Means for Solving the Problems] In order to achieve this object, the present invention provides a hydraulic clutch structure for a continuously variable transmission having a starting hydraulic clutch that causes a creep state to occur, in which a pressure plate is installed in a housing sub-member. The hydraulic clutch is formed by arranging a Belleville spring and an end plate, and the touch-off pressure value is changed by changing the amount of movement of the pressure plate to the end plate, and the creep state of the hydraulic clutch is kept approximately constant. The present invention is characterized in that the thickness of the snap ring that fixes the end plate to the housing sub-member is made different so that the end plate is exposed.

[Function] With the configuration described above, when the hydraulic clutch is mounted on an actual vehicle, the thickness of the snap ring is varied to vary the amount of movement of the pressure plate to the end plate, and the touch-off pressure value is varied to adjust the pressure of the hydraulic clutch. The creep state appears almost constant, improving adjustment workability and reducing costs.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

1 to 6 show embodiments of this invention. Second
In the figure, 2 is a continuously variable transmission, such as a belt-driven continuously variable transmission, 2A is a belt, 4 is a drive pulley, 6 is a drive side fixed pulley part, 8 is a drive side movable booby part, and 10
1 is the driven side pulley, 12 is the driven side fixed pulley part, 1
4 is a driven side movable pulley piece. The drive-side pulley 4 includes a drive-side fixed pulley part 6 fixed to the rotating shaft 16.
and a drive-side movable pulley piece 8 mounted on the rotating shaft 16 so as to be movable in the axial direction of the rotating shaft 16 but not rotatable. Further, similarly to the driving pulley 4, the driven pulley 10 includes a fixed driven pulley piece 12 and a movable driven pulley piece 14.

First and second housings 18.20 are attached to the drive side movable pulley piece 8 and the driven side movable pulley piece 14, respectively, and first and second hydraulic chambers 22.24 are formed, respectively. . At this time, a biasing means 26 made of a spring or the like is provided in the second hydraulic chamber 24 on the driven side to bias the second housing 20 in the direction of expansion of the second hydraulic chamber 24.

An oil pump 28 is provided on the rotating shaft 16, and the oil pump 28 is connected to the first and second hydraulic chambers 22,24.
The second oil passages 30 and 32 communicate with each other, and a primary pressure control valve 34, which is a speed change control valve, is provided in the middle of the first oil passage 3o to control the primary pressure, which is the input shaft sheave pressure. In addition, a line pressure (generally 5 to 25 kg/C
The primary pressure control valve 3
4 is communicated with a first three-way solenoid valve 42 for primary pressure control through a fourth oil passage 40.

Further, a line pressure control valve 4 having a relief valve function for controlling the line pressure, which is the pump pressure, is disposed in the middle of the second oil passage 32.
4 is communicated through a fifth oil passage 46, and a second three-way solenoid valve 50 for line pressure control is communicated with this line pressure control valve 44 through a sixth oil passage 48.

Furthermore, a clutch pressure control valve 52 for controlling clutch pressure is installed in the seventh oil passage 5 in the middle of the second oil passage 32 on the side of the second hydraulic chamber 24 than the communicating portion of the line pressure control valve 44.
4, and a third direction solenoid valve 58 for clutch pressure control is connected to this clutch pressure control valve 52 through an eighth oil passage 56.
Communicate.

Further, the primary pressure control valve 34, the first solenoid valve 42 for primary pressure control, the constant pressure control valve 38, the sixth oil passage 48, the second solenoid valve 501 for line pressure control, and the clutch pressure control valve 52 are connected to the ninth oil passage. 60, respectively.

The clutch pressure control valve 52 is communicated with a hydraulic start clutch 62, which is a hydraulic clutch, through a tenth oil passage 64, and a pressure sensor 68 is communicated with the tenth oil passage 64 through an eleventh oil passage 66. This pressure sensor 68 can directly detect oil pressure when controlling clutch pressure in hold and start modes, etc.
It contributes when commanding this detected oil pressure to be the target clutch pressure. Furthermore, since the clutch pressure becomes equal to the line pressure in the drive mode, it also contributes to line pressure control.

An input shaft rotation detection gear 70 is provided on the outside of the first housing 18.
A first rotation detector 72 on the input shaft side is provided near the outer peripheral portion of the input shaft rotation detection gear 70. Further, an output shaft rotation detection gear 74 is provided on the outside of the second housing 20, and a second rotation detector 76 on the output shaft side is provided near the outer peripheral portion of the output shaft rotation detection gear 74. Detection signals from the first rotation detector 72 and the second rotation detector 76 are output to a control unit (ECU) 82, which will be described later, to determine the engine rotation speed and belt ratio.

The hydraulic start clutch 62 is provided with an output transmission gear 78, and a third rotation detector 80 for detecting the rotation of the final output shaft is provided near the outer periphery of the gear 78. In other words, this third
The rotation detector 80 detects the rotation of the final output shaft directly connected to the reduction gear, the differential, the drive shaft, and the tires.
Vehicle speed can be detected. Further, the second rotation detector 7
8 and the third rotation detector 80, the hydraulic starting clutch 6
It is also possible to detect rotations around 2, which contributes to detecting the amount of clutch slip.

Furthermore, various conditions such as a throttle opening of a carburetor (not shown) of the vehicle, engine rotation from the first to third rotation detectors 72, 76, 80, vehicle speed, etc. are input, and the duty ratio is changed to perform gear change control. A control section 82 controls the first three-way solenoid valve 42 and constant pressure control valve 38 for primary pressure control, the second three-way solenoid valve 50 for line pressure control, and the third three-way solenoid valve 58 for clutch pressure control. It is configured to control the opening/closing operation and also control the pressure sensor 68. Further, in detail, the functions of various signals and input signals input to the control section 82 are as follows: (1) Shift lever position detection signal...... by each range signal such as P, R, N1D, L, etc. Line pressure and ratio required for each range, clutch control, carburetor throttle opening detection signal...
Detects the engine torque from the memory input into the program in advance, determines the target ratio or target engine speed, detects the carburetor idle position, and improves accuracy in correction and control of the carburetor throttle opening sensor. , Accelerator pedal signal: Detects the driver's intention based on the state of depression of the accelerator pedal and determines the direction of control when driving or starting ■, Brake signal: Detects the driver's intention based on the state of depression of the accelerator pedal. Detects the presence and determines the control direction such as clutch disengagement■, Power mode option signal...It is used as an option to make the performance of the vehicle more sporty (or more economical).

The hydraulic starting clutch 62 is connected to a housing sub-member 84.
Pressure plate 86 and Belleville spring 88 inside
and an end plate 90.

Specifically, as shown in FIG. 1, a sleeve 92 is installed within the housing sub-member 84, and a piston 98 is installed in the sleeve 92 via a piston seal 96 to form a hydraulic chamber 94.

Then, the inner circumferential edge portion of the retractor plate 100 is attached to the piston 98, and this retractor plate)
A Belleville spring 88 is provided on one side of the retractor plate 100 to urge the retractor plate 100 toward the piston 98 side, and the pressure plate 86 is attached to the other side of the retractor plate 100.

Further, an end plate 90 is provided facing the pressure plate 86 via the friction member 102, and the friction member 1
02 is attached to the end play) 90 side, the inner circumferential portion of the friction member 102 is attached to a friction plate 104, and the output transmission gear 78 is provided in communication with this friction plate 104.

Furthermore, the housing sub-member 84 and the retractor plate 100 are attached by a first snap spring 106,
The piston 98 and the tractor plate 100 are connected to a second
At the same time, the housing sub-member 84 and the end plate 90 are attached using a third snap ring 110.

Then, the end plate 90 is attached to the housing sub member 84.
In the third snap spring 110, which is fixed to the third snap ring 110, the amount of movement of the pressure plate 86 up to the end play 90 is changed to change the touch-off pressure value, so that the creep state of the hydraulic start clutch 62 appears approximately constant. The third snap spring 110 is configured to have different thicknesses.

Note that 112 is a fourth snap ring, 114 is an oil pan, and 11B is an oil filter.

As shown in FIG. 2, in the belt-driven continuously variable transmission 2, an oil pump 28 located on the rotating shaft 16 operates in accordance with the drive of the rotating shaft 18, and the oil is pumped into an oil pan 114 at the bottom of the transmission. The oil is absorbed through the oil filter 116. The line pressure, which is this pump pressure, is controlled by a line pressure control valve 44, and if the amount of leakage from this line pressure control valve 44, that is, the amount of relief from the line pressure control valve 44 is large, the line pressure will be low; If it is less, the line pressure will be higher.

The operation of the line pressure control valve 44 is controlled by a dedicated second three-way solenoid valve 50, and the line pressure control valve 44 operates in accordance with the operation of the second three-way solenoid valve 50. , the second three-way solenoid valve 50 is controlled at a duty rate of a constant frequency. That is, a duty rate of 0% means that the second three-way solenoid valve 50 does not operate at all, the output side is connected to the atmosphere, and the output oil pressure is zero. Further, when the duty rate is 100%, the second three-way solenoid valve 50 operates and the output side is connected to the atmosphere side, and the maximum output oil pressure is the same as the control pressure, and the output oil pressure is varied depending on the duty rate.

The clutch pressure control valve 52 that controls the clutch pressure is connected to the line pressure when the maximum clutch pressure is required, and connected to the atmosphere side when the minimum clutch pressure is required. The operation of this clutch pressure control valve 52 is also controlled by a dedicated third three-way solenoid valve 58, similarly to the line pressure control valve 44 and the primary pressure control valve 34. Clutch pressure varies within a range from minimum atmospheric pressure (zero) to maximum line pressure.

There is a basic pattern for clutch pressure control, which will be described later.This basic pattern is as follows: (1) Neutral mode: When the clutch is completely disengaged with the shift position N or P, the clutch pressure is the lowest pressure ( zero) (2),
Hold mode: When the shift position is D or R and you release the throttle and have no intention of driving, or when you want to decelerate and cut off the engine torque while driving, the clutch pressure is set to a low level that the clutch contacts ( 3) Start mode: When starting or when trying to re-engage the clutch after the clutch has been disengaged, the clutch pressure is adjusted to prevent the engine from revving up and to maintain engine-generated torque (clutch input) that allows the vehicle to operate smoothly. Drive mode: When the clutch is fully engaged when the vehicle is in full driving mode, the clutch pressure should be set at a high enough level to withstand the engine torque. There are four levels. (1) of this basic pattern is performed by a dedicated switching valve (not shown) that is linked to the shift operation, and the other (2), (3), and (4) are performed by the first to third solenoid valves 42 controlled by the control section 82. .50. This is done by duty rate control of No. 58. Especially in the situation (4),
The seventh oil passage 54 and the tenth oil passage 64 are communicated with each other by the clutch pressure control valve 52, and the maximum pressure is generated, and the clutch pressure becomes the same as the line pressure.

In addition, the primary pressure control valve 34 and the line pressure control valve 4
4, and the clutch pressure control valve 52 is controlled by the output oil pressure from the first to third three-way solenoid valves 42.50.58, respectively.
The control oil pressure that controls 0.58 is the constant pressure control valve 38.
It is made with constant oil pressure. This control oil pressure is always higher than the line pressure, but it is a stable and constant pressure. In addition, the control oil pressure is 34.44 for each control valve.
．． 52 is also introduced to stabilize these control valves 34, 44, and 52.

Next, the effect will be explained.

Next, electronic control of the belt-driven continuously variable transmission 2 will be explained.

Continuously variable transmission 2 is hydraulically controlled, and in response to commands from control unit 82, appropriate line pressure for belt retention and torque transmission, primary pressure for changing gear ratio, and clutch engagement are ensured. Clutch pressure is secured for each.

When the clutch pressure of the hydraulic starting clutch 62 is gradually increased from O, the piston 9 moves as shown by the white arrow in FIG.
8 operates against the biasing force of Belleville spring 88,
This movement of the piston 98 causes the pressure plate 8 to
6 in the direction of the outlined arrow. Then, when the clutch pressure is further increased, the touch-off pressure value is reached,
The pressure plate 86 is in close contact with the end plate 90 via the friction member 102, and the Frixilon plate 104
This is to contact.

The touch-off pressure value of the hydraulic starting clutch 62 changes in proportion to the amount of movement of the pressure plate 86, as shown in FIG.
The amount of movement of 6 varies depending on the thickness of the third snap spring 110.

That is, the thickness A1 of the third snap spring 110 is A2,
Or if you thin it to A3 (A 1 > A2 > A3)
, the amount of movement of the pressure plate 86 increases, and the touch-off pressure value increases from B1 to B2 or B3. On the other hand, if the thickness of the third snap ring 110 is increased, the amount of movement of the pressure plate 86 is decreased, and the touch-off pressure value is decreased.

As a result, the amount of movement of the pressure plate 86 can be easily changed by changing the thickness of the third snap ring 11O, and the touch-off pressure value can be adjusted to a substantially constant value, and at the same time, the pack clearance can also be substantially reduced. It can be adjusted to a constant value, a uniform leap state can be obtained, and clutch pressure control can be simplified.

Furthermore, by preparing several types of the third snap springs 110 with different thicknesses, the touch-off pressure value can be adjusted to a substantially constant value, the structure is not complicated, and the cost can be reduced, which is economically advantageous. .

Furthermore, since the adjustment of the touch-off pressure value of the hydraulic start clutch 62 is performed after assembly, the assembly of the third snap spring 110 is the final step, so the pressure plate 86, friction plate 104, Alternatively, compared to the method in which the thickness of the end plate 90 is adjusted, the reassembly work of the third snap ring 110 is easier, the workability can be improved, and this is advantageous in practice.

Furthermore, even if members such as each plate are worn out over time and the touch-off pressure value becomes large, the third
By varying the thickness of the snap ring 110, the touch-off pressure value can be adjusted as desired, and maintenance and inspection can be facilitated.

[Effects of the Invention] As explained in detail above, according to the present invention, a pressure plate, a Belleville spring, and an end plate are disposed within a housing sub-member to form a hydraulic clutch,
The thickness of the snap ring that fixes the end plate to the housing sub member is varied in order to change the touch-off pressure value by changing the amount of movement of the pressure plate to the end plate, and to maintain a substantially constant creep state of the hydraulic clutch. Because of the structure, the amount of movement of the pressure plate can be easily changed by changing the thickness of the snap ring, making it possible to adjust the touch-off pressure value to a substantially constant value, and at the same time keep the puck clearance substantially constant. The clutch pressure can be adjusted to a uniform value to obtain a uniform leap state, and the clutch pressure control can be simplified. Moreover, by preparing several types of snap rings with different thicknesses, the touch-off pressure value can be adjusted to a substantially constant value, the structure is not complicated, and the cost can be reduced, which is economically advantageous. Furthermore, since the adjustment of the touch-off pressure value of the hydraulic clutch is performed after assembly, the assembly of the snap ring is the final process, so the thickness of each plate such as the pressure plate is adjusted. This method is advantageous in practical terms because it makes it easier to rearrange the snap ring and improves workability. Furthermore, even if members such as plates wear out over time and the touch-off pressure value increases, by making the snap rings different in thickness, the touch-off pressure value can be adjusted to the desired value, making maintenance and maintenance easier. This makes inspection easier.

[Brief explanation of drawings]

1 to 6 show embodiments of the present invention, FIG. 1 is an enlarged sectional view showing the operating state of a hydraulic starting clutch, FIG. 2 is a block diagram of a belt-driven continuously variable transmission, and FIG. 3 is a hydraulic A sectional view of the starting clutch, FIG. 4 is a left side view of the hydraulic starting clutch, FIG. 5 is a right side view of the hydraulic starting clutch, and FIG. 6 is a diagram showing the relationship between the thickness of the third snap spring and the touch-off pressure value. It is. FIG. 7 is a diagram showing the relationship between the amount of pressure plate movement and clutch pressure, showing the prior art of the present invention. In the figure, 2 is a belt-driven continuously variable transmission, 2A is a belt, 4 is a driving pulley, 10 is a driven pulley, 6
2 is a hydraulic starting clutch, 82 is a control unit, 84 is a housing sub-member, 86 is a pressure plate, 88 is a Belleville spring, 90 is an end plate, 98 is a piston, lOO is a retractor plate, 104 is a Frixilon plate, 10B is a 1 snap spring, 108 is the second
Snap ring, 110 is the third snap ring, 11
2 is the fourth snap spring. Patent Applicant Suzuki Motor Co., Ltd. Agent Yoshimi Nishigo Figure 1 Figure 2 Figure 3 and 2 Figure 4 Figure 5 Figure 6 Figure 7 Retsuya Yuki

Claims (1)

[Claims] 1. In a hydraulic clutch structure for a continuously variable transmission having a starting hydraulic clutch that exhibits a creep state, the hydraulic clutch is formed by disposing a pressure plate, a Belleville spring, and an end plate in a housing sub-member; The thickness of a snap ring that fixes the end plate to the housing sub member in order to change the amount of movement of the pressure plate to the end plate to change the touch-off pressure value so that the creep state of the hydraulic clutch appears approximately constant. A hydraulic clutch structure for a continuously variable transmission characterized by having a configuration that allows for different speeds.