JPH0124431Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is a clutch that connects and disconnects the power transmission system of an engine, particularly a clutch valve that is controlled by fluid pressure regulated according to the engine speed. This invention relates to an automatic clutch control device that is connected and disconnected in response to clutch pressure from the clutch.

(Prior art) Some automatic clutches that automatically engage and engage the clutch interposed in the power transmission system of an engine are equipped with automatic clutches that automatically engage and engage the clutch provided in the power transmission system of the engine. On the one hand, the clutch pressure of the clutch valve is controlled in accordance with the magnitude of the clutch pressure, and on the other hand, there is a system in which the clutch pressure of the clutch valve is controlled by the fluid pressure, that is, the governor pressure, which is regulated in accordance with the engine speed. . In such an automatic clutch, as the governor pressure increases, the clutch pressure increases and the clutch is engaged, but when the clutch is initially engaged, the governor pressure, or clutch The clutch enters a so-called half-clutch state in which the tendency for pressure to rise is weakened, and as the clutch pressure rises with subsequent rise in governor pressure, the clutch becomes fully engaged.

In this way, the clutch pressure is controlled by the governor pressure, which has the advantage of forming a half-clutch state when the clutch is initially engaged. If the load applied to the clutch becomes high, the above-mentioned half-clutch state may remain connected, resulting in damage to the clutch (damage to the clutch plate). To elaborate on this point, when climbing a steep slope, the engine speed does not increase or increases very slowly, so the governor pressure does not increase, and therefore the clutch changes from a partially engaged state to a fully engaged state. Sufficient clutch pressure for shifting cannot be obtained, and the half-clutch state remains as described above.

(Purpose of the invention) The present invention has been developed in consideration of the above-mentioned circumstances, and is designed to prevent a half-clutch state from being sustained in a clutch valve in which the clutch pressure is controlled by governor pressure. It is an object of the present invention to provide an automatic clutch control device that can prevent clutch damage caused by the clutch becoming stuck.

(Structure of the invention) In order to achieve the above-mentioned object, in the present invention, the state of supply of clutch pressure to the clutch is detected, and when a predetermined delay time has elapsed from the start of supply of clutch pressure, A control device is provided to force the clutch valve to operate to provide a clutch pressure greater than that provided by the governor pressure.

By providing such a control device, even if the engine speed, that is, the governor pressure does not increase, the clutch pressure will be sufficiently increased after a predetermined time has elapsed, so that the clutch can be changed from a partially engaged state to a fully engaged state. This prevents damage to the clutch. Of course, since this control device operates with a delay after the start of supply of clutch pressure to connect the clutch, it is possible to obtain a half-clutch state at the beginning of the clutch engagement.

(Embodiment) In FIG. 1, the output of an engine 1 is transmitted to the wheels 5 of an automobile via a clutch 2, a continuously variable transmission 3, and a differential gear 4. The power transmission machines up to 5 constitute the engine power transmission system.

An example of the clutch 2 will be explained with reference to FIG. 2. It has a clutch drum 10 and a clutch hub 11, which are arranged to be rotatable relative to each other.
A drive plate 12 is attached to the clutch drum 10.
However, the clutch hub 11 also holds a driven plate 13. When the drive plate 12 and the driven plate 13 are separated from each other, the clutch drum 10 and the clutch hub 11 can rotate relative to each other when the clutch is disconnected.On the other hand, when the plates 12 and 13 are in pressure contact with each other, the clutch is disconnected. When the clutch is connected, the drum 10 and the clutch hub 11 rotate integrally with each other. A state in which the plates 12 and 13 are in contact with each other with slight sliding is a so-called half-clutch state. Of course, the clutch input shaft 2a (see FIG. 1), which rotates integrally with the clutch drive plate 10 that is the input side of the clutch 2, is connected to the output shaft of the engine 1, and is also integrally connected to the clutch hub 11 that is the output side of the clutch 2. converted clutch output shaft 2b
(see FIG. 1) is coupled to a continuously variable transmission 3.

The clutch 2 is a hydraulic actuator 1.
The actuator 14 is controlled by the actuator 4.A piston 15 is held within the clutch drum 10 so as to be slidable in the axial direction of the clutch drum 10, and the piston 15 and the clutch drum 10 An oil chamber 16 is defined. When pressure oil (clutch pressure to be described later) is supplied into the oil chamber 10 from the oil port 18, the piston 15 is displaced to the left in FIG. and 1
3 in the contact direction, and when this pressure oil is released, the return spring 17 causes the piston 15 to
is in a disengaged state with the clutch returned to its original position.
Therefore, by adjusting the pressing force between the clutch plates 12 and 13 by the piston 15, the clutch 42 can take the above-mentioned half-clutch state and connected state as appropriate.

As shown in FIG. 3, the continuously variable transmission 3 has an input shaft 20 and an output shaft 21 that are parallel to each other, and a primary pulley 22 is connected to the input shaft 20 coupled to the clutch output shaft 2b. A secondary pulley 23 is provided on the output shaft 21 connected to the differential gear 4, and both pulleys 22 and 23
A V-belt 24 is wound between the two. The primary pulley 22 is composed of a fixed flange 25 that is integrated with the input shaft 20 and a movable flange 26 that can be slidably displaced with respect to the input shaft 20. The movable flange 26 controls the amount of oil supplied to the hydraulic actuator 27. The winding radius of the V-belt 24 around the primary pulley 22 increases as it approaches the fixed flange 25. Similarly to the primary pulley 22, the secondary pulley 23 also includes a fixed flange 28 that is integrated with the output shaft 21, and a movable flange 29 that can be slidably displaced with respect to the output shaft 21. As the amount of oil supplied to the hydraulic actuator 30 increases, the V-belt 24 approaches the fixed flange 28 and the winding radius of the V-belt 24 around the secondary pulley 23 increases.

In this way, both hydraulic actuators 27,
The rotation ratio of both pulleys 22 and 23, that is, the gear ratio, is changed in accordance with the supply and discharge of hydraulic pressure to and from the hydraulic pressure 30, but this change in gear ratio is performed by a gear change predetermined based on, for example, the engine rotation speed and the engine load. This was done according to the characteristics.

In Figure 2, 40 is a manual shift valve, 50
is the clutch valve. This clutch valve 5
0 is for obtaining a predetermined clutch pressure to be supplied to the hydraulic actuator 14 of the clutch 2, as will be described later, and is for obtaining a predetermined clutch pressure to be supplied to the hydraulic actuator 14 of the clutch 2.
This clutch pressure is supplied to and stopped from the hydraulic actuator 14 according to the shift position. That is, the manual shift valve 40 includes a main body 41 and a spool valve 42 that can be slid inside the main body 41, and when the spool valve 42 operated by the driving vehicle is in the L or D shift position, , the inlet 43 is connected to the first outlet 44
and when in the R shift position,
The inlet 43 is communicated with the second outlet 45, and when the shift position is N or P, the inlet 4
3 to a drain port (not shown). The first outlet 44 is connected to a pipe 47.
The second outlet 45 is connected to the oil inlet 18 of the clutch 2 through the clutch 2, and the second outlet 45 is connected to another clutch other than the clutch 2, which is not shown.

The other clutches mentioned above are attached to the planetary gear mechanism together with the clutch 2 shown in FIG. 2 and are used during reversing, and have the same structure as the clutch 2. When the clutch is connected, the other clutch is disconnected and power is transmitted in the forward direction of the vehicle, and when the other clutch is connected and clutch 2 shown in Figure 2 is disconnected, the vehicle is moved in the reverse direction. directional power transmission is performed. That is, the clutch 2 in FIG. 2 is representatively shown in only the forward direction of the clutch 2 in FIG. 1. Of course, the clutch 2 shown in FIG. 2 may also be used for the aforementioned reverse movement, and a mechanism for reverse movement may be provided separately and independently from the clutch 2 shown in FIG.

The clutch valve 50 includes a main body 51 and a main body 5.
1, a spool valve 52 capable of sliding displacement within the spool valve 1;
The main body 51 has its own valve hole 5.
A clutch pressure port 53 and a drain port 54 that open to the spool valve 1a, and a governor pressure port 55 that opens to the governor chamber A formed on the back side of the spool valve 52 (the right end side in FIG. 2) are formed. This clutch pressure 53 is connected to an oil pump 57 via a pipe 56, and is also connected to an inlet 43 of a manual shift valve 40 via a branch pipe 56a of the pipe 56. Further, the governor pressure inlet 55 is connected via a pipe 58 to a known pressure regulating device 59 which is driven by the engine 1 and obtains a fluid pressure, that is, a governor pressure Pg, which is regulated according to the engine speed. Of course, this governor pressure Pg increases as the engine speed increases.

Such a clutch valve 50 is such that the more the spool valve 52 is displaced to the left in FIG. 2, the more the oil pump 5
The line pressure from the clutch pressure port 5 is suppressed from escaping from the drain port 54 through the valve hole 51a.
3, that is, the clutch pressure Pc supplied to the inlet 43 of the manual shift valve 40 is increased. Conversely, as the spool valve 52 is positioned to the right in FIG. 2, the amount of line pressure escaping from the drain port 54 increases, and the clutch pressure Pc is reduced.

The above-mentioned displacement position of the spool valve 52 in the left-right direction in FIG. 2, that is, the magnitude of the clutch pressure Pc, depends on the magnitude of the governor pressure Pg that acts to press and displace the spool valve 52 to the left in FIG. However, in this embodiment, this clutch pressure Pc is controlled not only by the governor pressure Pg but also by the throttle pressure Pth.
It has also come to be controlled by To explain this point, a piston 60 is slidably held in the main body 51 in series with the spool valve 52 on the left side in FIG.
With respect to the throttle chamber B formed on the left end surface of the figure,
The slotted pressure inlet 61 is open. The throttle pressure inlet 61 is connected via a pipe 62 to a known pressure regulating device 63 for obtaining a fluid pressure regulated according to the throttle opening, that is, a throttle pressure Pth. Of course, this throttle pressure Pth increases as the throttle opening increases.

A spring 64 is interposed between the piston 60 and the spool valve 52, so that the piston 60 is displaced to the right in FIG. 2 according to the magnitude of the throttle pressure Pth. The displacement to the right in FIG. 2 is transmitted to the spring 52. That is, if the governor pressure Pg is the same, the clutch pressure Pc is made smaller as the throttle pressure Pth becomes larger.

The clutch valve 50 is equipped with a control device 70, which is an improvement in the present invention. In the embodiment, this control device 70 includes a spool valve 52
On the right side in FIG. 2, a piston rod 73 of a piston 72, which is provided with a cylinder 71 formed in the main body 51 of the clutch valve 50 and is slidably inserted into the cylinder 71, is attached to the back surface of the spool valve 52. It is possible to come into contact with it. This piston 72
The branch pipe 56a is connected to the oil chamber C defined by the branch pipe 56a.
A branch pipe 56b is connected to the branch pipe 56b, and an electromagnetic on-off valve 74 is connected in the middle of the branch pipe 56b. A branch pipe 56c further branches from the branch pipe 56b from the upstream side of the solenoid valve 74.
A timer 75 is connected to. This timer 75 sets the clutch pressure Pc to a predetermined pressure P ₀ (see Fig. 4).
When a predetermined time t (see Fig. 4) has elapsed after the start of counting, the electromagnetic on-off valve 74 is opened and clutch pressure Pc is supplied to the oil chamber C of the cylinder 71. ing.
Then, by supplying the clutch pressure Pc into the oil chamber C, the spool valve 52 is forcibly pushed leftward in FIG. 2 by the piston rod 73, and the clutch pressure
PC is starting to rise. In addition, 76
is the return spring of the piston 72.

Next, regarding the effect of the above configuration, the fourth
This will be explained with reference to the figure, but in this figure 4,
The α ray indicates the governor pressure Pg, the β ray indicates the clutch pressure Pc in the case of the present invention, and the γ ray indicates the clutch pressure in the conventional case.

Assuming that the manual shift valve 40 is located in the L or D shift device, for example, when the throttle opening is increased to start the car, the engine speed increases and the governor pressure Pg also increases. Following the increase in Pg, the clutch pressure Pc is also increased. This clutch pressure Pc is supplied to the oil chamber 16 of the hydraulic actuator 14, and the piston 2 is displaced in the direction of connecting the clutch 2. When the clutch 2 enters a half-clutch state in which the drive plate 12 and the driven plate 13 are connected while sliding, the engine load increases, so that the tendency for the governor pressure Pg to rise, that is, the tendency for the clutch pressure Pc to rise, weakens.

In this half-clutch state, if the car tries to run on a flat road or other conditions where high loads are not applied, the engine speed will quickly rise and the governor pressure Pg will rise, so the clutch pressure Pc will also rise. , clutch 2 is fully engaged.

On the other hand, in the above-mentioned half-clutch state, under high load conditions such as when the automobile is climbing a steep slope, the engine speed does not increase and the half-clutch state tends to be maintained. however,
In the present invention, the timer 75 starts operating when the clutch pressure reaches P ₀ , which is before the half-clutch state.
After time _t1 , which is delayed by a predetermined time t from the time _t0 when this clutch pressure _P0 is detected, the electromagnetic on-off valve 74 is opened and the spool valve 52 is forcibly displaced to the left in FIG. 2 as described above. let As a result, the clutch pressure Pc increases, and the clutch 2 is shifted from the above-mentioned half-clutch state to a fully connected state, thereby preventing damage to the clutch 2 due to being left in the half-clutch state.

Although not shown in Figure 4, in reality,
A preload of about 0.5 kg/cm ² is given in advance as the clutch pressure Pc, and a value of about 1 kg/cm ² is adopted as the clutch pressure P ₀ as a condition for starting the operation time of the timer 75. Further, the delay time t depends on the durability of the clutch 2, but the delay time t is 10
It is sufficient to set the time to ~20 seconds. Of course,
The timer 75 starts the electromagnetic on-off valve 74 when the clutch 2 is disengaged and the clutch pressure Pc becomes less than _P0 .
Let be closed. Furthermore, even when the clutch is quickly shifted from a half-clutch state to a clutch connection, such as when driving on a flat road, the spool valve 52 is controlled by the control device 7.
0, it is forcibly displaced to the left in FIG. 2, but this does not cause any particular problem.

Here, in this embodiment, the throttle pressure
Pth also controls the clutch pressure Pc.
In other words, a correction is made so that the clutch pressure becomes smaller as the throttle opening is not large, but by making this correction, it is possible to always ensure smooth connection according to the transmitted torque of clutch 2. Become. In other words, as the throttle opening increases, the transmission torque of the clutch 2 increases, but as this transmission torque increases, by slowly connecting the clutch, this large transmission torque can be sufficiently absorbed and the connecting shock increases. can be constantly reduced.

FIG. 5 shows another embodiment of the present invention, in which the same components as those in the previous embodiment are given the same reference numerals and their explanation will be omitted.

In this embodiment, two orifices 80 and 81, a first and second orifice, are used as the control device 70. That is, the main body 51a of the clutch valve 50 is formed with a cylinder 82, and the spool valve 52 is formed with the cylinder 82.
It has a piston portion 52a that extends slidably therein. A clutch pressure inlet 83 and a drain port 84 are opened to the oil chamber D in the cylinder 82 defined by the piston portion 52a, and the clutch pressure inlet 83 has a drain port 84 for transmitting the clutch pressure Pc. A branch pipe 56b is connected. A first orifice 80 is provided at the clutch pressure inlet, and a second orifice 81 having a smaller diameter than the first orifice 80 is provided at the drain port 84.

As a result, the amount of oil escaping from the oil chamber D through the drain port 84 is smaller than the amount of oil supplied from the clutch pressure inlet 83 to the oil chamber D, so the oil chamber D is eventually filled with oil. The spool valve 52 is forcibly displaced to the left in FIG. 2 in response to the clutch pressure Pc in the oil chamber D, and the clutch 2 is securely connected. Note that the first orifice 80
By appropriately setting the diameters of the second orifice 81 and the second orifice 81, the delay time required for forcibly displacing the spool valve 52 can be set to a desired value.

(Effects of the invention) As is clear from the above, the invention has the following effects:
If the half-clutch state continues for a predetermined period of time or more, the clutch is forcibly connected completely, so that damage to the clutch caused by the half-clutch state continuing for a long time can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an example of an engine power transmission system. FIG. 2 is an overall system diagram showing an embodiment of the present invention. FIG. 3 is a partially sectional side view showing an example of a continuously variable transmission. FIG. 4 is a graph schematically showing the action of the present invention. FIG. 5 is a sectional view of main parts showing another embodiment of the present invention. 1... Engine, 2... Clutch, 14... Fluid actuator, 50... Clutch valve,
59...Pressure regulating device, 70...Control device.

Claims (1)

[Scope of Claim for Utility Model Registration] A clutch that connects and disconnects an engine power transmission system, a fluid-type actuator that operates the connection and disconnection of the clutch, and a clutch valve that controls the magnitude of clutch pressure supplied to the fluid-type actuator. a pressure regulating device that regulates the fluid pressure for controlling the clutch valve according to the engine speed; and detecting the supply state of the clutch pressure controlled by the clutch valve to the clutch;
After a delay time after the start of supply of the clutch pressure, the clutch valve is forcibly operated so that a clutch pressure greater than the clutch pressure obtained by the fluid pressure regulated by the pressure regulating device is obtained. An automatic clutch control device comprising: a control device;