JPH07127660A - Cooling device for hydraulic control type clutch - Google Patents

Abstract

PURPOSE:To prevent clutch slip at high rotating speed by providing a subbypass passage on the main passage of an oil spray control valve, and closing the main passage at being low and high in pilot pressure oil and opening it at medium pressure so as to control a quantity of spray. CONSTITUTION:When pilot pressure oil PC1 is at low pressure in low clutch pressing force, a spool valve 22 closes a main passage 20 and a sub-bypass passage 25 and opens a sub-bypass passage 21. Consequently cooling oil is passed through the passage 21 so as to reduce the flow, and injected to a hydraulic clutch by oil spray 4. When the pressure oil PC1 is at medium pressure in half clutch, the passage 21 is closed and the passages 20, 25 are opened. Consequently cooling oil is passed through the passage 20 so as to inject a large quantity of oil. When the pressure oil PC1 is at high pressure in close contact of clutch, the passages 20, 25 are opened. Consequently the cooling oil passed through the passage 20 is reduced in flow by the passage 25 and injected. Hereby the oil level in an oil pan can be insured, and clutch slip due to suction of air at high engine speed can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for a hydraulically controlled clutch.

[0002]

2. Description of the Related Art There is a device for automatically controlling a clutch and a transmission of an automobile by hydraulic pressure. The mechanism, as shown in FIG. 4, is discharged from the control system oil pump 5,
A flow control valve 6 that controls the pressure oil filtered by the filter 12 to a constant flow rate, and a hydraulic control type that switches the pressure oil controlled to a constant flow rate to either the hydraulic clutch 3 side or the transmission (not shown) side. Switching valve 7, an electromagnetic switching valve 8 for switching between the hydraulic clutch 3, disconnection control cylinder, transmission shift control cylinder 1 and transmission control cylinder 2, and the pressure oil discharged from the spray oil pump 9. Of the oil cooler 10, an oil spray 4 for injecting the pressure oil cooled by the oil cooler 10 to the hydraulic clutch 3, and an oil spray control valve 11 for controlling the spray flow rate of the oil spray 4. .

As shown in FIG. 5, the oil spray control valve 11 is provided with a normal main passage 20 connected to the spray system pump 9 and a sub-bypass passage 21 for reducing the flow rate below the main passage 20. This main passage 2
Spool valve 22 for switching between 0 and the sub bypass passage 21
The spool valve 22 is provided with a spring 23 at one end and a pilot port 24 for introducing the control pressure oil PC1 of the hydraulic clutch 3 at the other end.

[0004]

In the oil spray control valve 11, when the control pressure oil PC1 of the hydraulic clutch 3 (hereinafter referred to as pilot pressure oil PC1) has a low clutch pressing force, the spool valve 22 in FIG. Moving to the right end, closing the main passage 20 and opening the sub-bypass passage 21 to reduce the spray flow rate to the oil spray 4, but when the intermediate pressure of the half clutch and the high pressure when the clutch is in close contact, the spool The valve 22 moves to the left end and opens the main passage 20 and the sub bypass passage 21. As a result, the spray system pump 9 increases the oil suction amount and the discharge amount in proportion to the engine speed, so that the spray flow rate naturally increases as shown in FIG.

It is necessary to cool the hydraulic clutch 3 with a large flow rate of spray when a half-clutch where frictional heat is generated, and when the clutch pressing force is low and when the clutch is in high pressure, a small flow rate of spray is required. Although the flow rate is sufficient, as described above, since the spray flow rate is in an increased state even when the clutch is in high pressure, the spray pump 9 that increases the oil suction amount in proportion to the engine rotation speed is The oil level in the oil pan drops during rotation,
There is a problem that the air is sucked in and the clutch slips due to it.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and its characteristic configuration is a flow rate for controlling pressure oil discharged from a control system oil pump to a constant flow rate. A control valve, an electromagnetic switching valve that switches pressure oil controlled to a constant flow rate to the hydraulic clutch disengagement, shift control cylinder and transmission shift, select control cylinder, and cooling pressure oil discharged from the spray pump. And an oil sprayer for injecting the pressure oil cooled by the oil cooler to the hydraulic clutch,
A hydraulically controlled clutch equipped with an oil spray control valve for operating a spool valve with the control pressure oil of the hydraulic clutch as a pilot to control the spray flow rate of oil spray, and in a hydraulic circuit of a transmission, the oil spray control valve An ordinary main passage is provided with a sub-bypass passage for reducing the flow rate from the main passage, and when the pilot pressure oil has a low clutch pressing force and a high pressure when the clutch is in close contact, the main passage is closed to open the sub-bypass passage, The main passage is opened to increase / decrease the spray flow rate when the intermediate pressure of the half clutch is reached.

[0007]

With the above construction, when the hydraulic clutch needs to be cooled with a large spray flow rate, the main passage provides a sufficient spray flow rate, and when the clutch pressing force is low and the clutch close contact is high, the sub-bypass passage is provided. This reduces the spray flow rate, ensures the oil level in the oil pan, and prevents the occurrence of clutch slip due to the intake of air when the engine rotates at high speed.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. The hydraulic control type clutch and the hydraulic circuit of the transmission are the same as those described with reference to FIG. 4, and the description thereof is omitted in this embodiment. In FIG. 1, reference numeral 11 is an oil spray control valve, which is provided with a normal main passage 20 connected to a spray system pump 9, a sub-bypass passage 21 for reducing the flow rate below the main passage 20, and an oil spray 4. A pilot port provided with a spool valve 22 that switches between the main passage 20 and the sub bypass passage 21, a spring 23 is provided at one end of the spool valve 22, and a control pressure oil PC1 of the hydraulic clutch 3 is introduced at the other end. 24 are provided.

Further, in the present invention, a sub-bypass passage 25 for reducing the flow rate from the main passage 20 is also provided on the oil spray 4 side, and the spool valve 22 has a main passage 20 when the pilot pressure oil PC1 has a low clutch pressing force. And the sub-bypass passage 25 are closed to open the sub-bypass passage 21, the sub-bypass passage 21 is closed at the time of high pressure when the clutch is in close contact, the main passage 20 and the sub-bypass passage 25 are opened, and the intermediate pressure of the half clutch is reached. Sometimes main passage 20
In addition, the sub-bypass passages 21 and 25 are opened.

Since the present invention has the above-described structure, when the pilot pressure oil PC1 has a low clutch pressing force, the pressure shown in FIG.
As shown in (A), the spool valve 22 is connected to the main passage 20.
And the sub bypass passage 25 are closed to open the sub bypass passage 21. Therefore, the cooling oil is supplied to the main passage 2
The spray flow rate is reduced through the 0 side sub-bypass passage 21 and, for example, 1 liter of cooling oil is injected from the oil spray 4 to the hydraulic clutch 3 per minute.

When the pilot pressure oil PC1 is at the intermediate pressure of the half clutch, as shown in FIG.
Is closed, and the main passage 20 and the sub bypass passage 25 are opened. Therefore, the cooling oil passes through the main passage 20 and a large flow rate, for example, 5 liters of cooling oil per minute is injected from the oil spray 4 to the hydraulic clutch 3.

When the pilot pressure oil PC1 is in high pressure when the clutch is in close contact, the main passage 20 and the sub bypass passage 25 are opened as shown in FIG. 1 (C). Therefore, the flow rate of the cooling oil passing through the main passage 20 is reduced by the sub-bypass passage 24 on the oil spray 4 side, and for example, 1 liter of cooling oil per minute is supplied to the oil spray 4.
More hydraulic clutch 3 is injected.

The above-mentioned spray flow rate control is shown in a graph. When the pilot pressure oil PC1 has a medium clutch half pressure, the spray flow rate increases in proportion to the pump rotation speed as shown in FIG. When the oil PC1 has a low clutch pressing force and the pilot pressure oil PC1 has a high pressure when the clutch is in close contact with the clutch, as shown in FIG. 3, the spray flow rate is controlled to a constant decreased flow rate even if the pump rotation speed is increased.

As a result of controlling the spray flow rate as described above,
When the hydraulic clutch 3 needs to be cooled with a large spray flow rate, the spray flow rate is set to a sufficient value for the half clutch, and the spray flow rate is reduced when the clutch pressing force that requires less cooling is low and when the clutch is in close contact with the high pressure. It secures the oil level in the pan and prevents the clutch from slipping due to the intake of air when the engine rotates at high speed.

[0015]

As described above, according to the present invention, the normal main passage of the oil spray control valve is provided with the sub-bypass passage for reducing the flow rate as compared with the main passage, and when the pilot pressure oil has a low clutch pressing force, Since the main passage is closed and the sub-bypass passage is opened at the time of high pressure when the clutch is in close contact, the main passage is opened when the intermediate pressure of the half clutch is open to control the spray flow rate.
A sufficient spray flow rate is required for the half-clutch that requires cooling of the hydraulic clutch, and the spray flow rate is reduced when the clutch pressing force is low and the clutch close pressure is high, which does not require much cooling, so the oil level in the oil pan is secured. Therefore, it is possible to prevent the occurrence of clutch slippage due to the intake of air when the engine rotates at high speed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a control operation of an oil spray control valve according to the device of the present invention.

FIG. 2 is a spray flow rate characteristic diagram at a medium pressure of a half clutch by the device of the present invention.

FIG. 3 is a spray flow rate characteristic diagram when the clutch pressing force by the device of the present invention is low and when the clutch is in close contact with high pressure.

FIG. 4 is a hydraulically controlled clutch to which the device of the present invention is applied;
Hydraulic circuit diagram of transmission

FIG. 5 is a sectional view of a conventional oil spray control valve.

FIG. 6 is a spray flow rate characteristic diagram of a conventional oil spray control valve.

[Explanation of symbols]

 3 Hydraulic clutch 4 Oil spray 9 Spray system oil pump 10 Oil cooler 11 Oil spray control valve 20 Main passage 21 Sub bypass passage 22 Spool valve 23 Spring 24 Pilot port 25 Sub bypass passage

Claims (1)

[Claims] 1. A flow rate control valve for controlling a constant flow rate of pressure oil discharged from a control system oil pump, disengagement of a hydraulic clutch for pressure oil controlled at a constant flow rate, shift / selection of a contact control cylinder and a transmission. An electromagnetic switching valve for switching to a control cylinder, an oil cooler for cooling the pressure oil discharged from the spray pump, an oil spray for injecting the pressure oil cooled by the oil cooler to the hydraulic clutch, and the hydraulic clutch In the hydraulic circuit of the hydraulic control clutch and the hydraulic circuit of the transmission, which operates the spool valve with the control pressure oil as a pilot and operates the oil spray control valve that controls the spray flow rate of the oil spray,
A sub-bypass passage is provided in the normal main passage of the oil spray control valve to reduce the flow rate below the main passage,
When the pilot pressure oil has a low clutch pressing force and a high pressure when the clutch is in close contact, the main passage is closed to open the sub-bypass passage, and when the intermediate pressure of the half clutch is open, the main passage is opened to control the spray flow rate. A cooling device for a hydraulically controlled clutch, characterized in that