JPS5824654B2 - Hydraulic clutch check valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a check valve for an oilfield operating clutch, and particularly to a check valve for ensuring reliable operation of the clutch.

The oilfield operating clutch has an oilfield operating chamber, and the clutch can be engaged and disengaged by supplying and discharging hydraulic oil to the oilfield operating chamber.

When oil is supplied to this hydraulic chamber from the inside in the radial direction, centrifugal force acts on the hydraulic oil in the hydraulic chamber when the clutch is rotating, so the hydraulic oil is supplied from the hydraulic chamber. Oil tends to remain in the hydraulic chamber even if you try to drain it.

This residual oil is subjected to centrifugal force and acts on the clutch piston, resulting in clutch dragging and engagement.

This tendency is particularly noticeable in clutches where the diameter of the hydraulic chamber is large and the rotational speed of the clutch is high.

A leaf spring type check valve has conventionally been known as one means for discharging this residual oil, but with this leaf spring type, even if the supply pressure is set to 0 when the clutch is released, the oil in the hydraulic chamber does not centrifuge. In order to overcome the force, it is necessary to set the opening force so that it opens even at the maximum rotation of the clutch.

However, if this setting is made, when hydraulic oil is supplied to the hydraulic chamber, the check valve will not close until the pressure in the hydraulic chamber reaches a high enough pressure to close the leaf spring type check valve, prolonging clutch drag. This causes problems such as accelerated wear of the clutch friction plates, and also causes problems in which hydraulic oil continues to leak until the check valve closes, resulting in a drop in oil pressure in the hydraulic system.

In order to improve this problem, if the hydraulic pump is made larger, it will become a load after the clutch is engaged, leading to a decrease in overall efficiency, and it will also be necessary to suddenly supply a large amount of hydraulic oil into the oilfield operating chamber and close the clutch valve all at once. As a result, there was a problem in which the oil field rose inside the hydraulic chamber, causing a large locking shock.

These problems are most noticeable at low rotation speeds when centrifugal force is less active.

The object of the present invention is to solve the above problems and obtain a check valve that opens and closes reliably, and also to reduce shift shock and increase durability when used in automatic transmissions for vehicles. That is.

To explain this with reference to the illustrated embodiment, 1 is a drive shaft, 2 is a driven shaft, 3 is a hydraulically operated clutch, and the clutch 3 has a clutch cylinder 4 connected to the drive shaft 1;
A clutch bub 5 connected to the driven shaft 2, and a friction material 6 consisting of drive plates 6a and driven plates 6b arranged alternately between the cylinder 4 and the bub 5, and the friction material 6 are engaged with each other. Clutch cylinder 4 to fit
A return spring that returns the clutch piston 7 to a hydraulic operating chamber 9 defined by the clutch piston T, the clutch piston 7 and the clutch cylinder 4 and connected to the hydraulic pressure supply path 8 provided in the drive shaft 1. 10, and the hydraulic working chamber 9 is provided with a check valve 11 to discharge residual oil, and the valve 11 connects the leak hole 12 provided through the wall of the working chamber 9 with its The clutch piston is a leaf spring type consisting of a leaf spring 13 provided opposite to the clutch piston so as to be opened by spring force, and the leak hole 12 is in contact with the friction material 6.

The leaf spring 13 is located on the piston 7 side and is located inside the annular bulge 7a provided protruding from the clutch piston 7. The leaf spring 13 is located in the radial direction of the hydraulic chamber 9, and its inner end is connected to the clutch piston with a rivet 14. 7, and its outer end extends beyond the leak hole 12.

A mass 15 is provided in the inner recess 7b formed in the annular bulge 7a, which receives centrifugal force and applies a force in a direction to assist the opening force of the leaf spring.

In the figure, reference numeral 16 indicates a stone or a par that restricts movement of the leaf spring 13 in the opening direction due to centrifugal force.

The mass 15 may be attached with a weight separate from the leaf spring 19 as shown in FIGS. 1 and 3, or the free end of the leaf spring may be bent as shown in FIG. Further, the mass 15 may be provided so as to be accommodated in the recess 7b provided in the clutch piston 7 as shown in FIGS. 14 and 2, or may be provided so as not to be accommodated in the recess 7b as shown in FIG. Frequently, the check valve may also be located on the side of the cylinder opposite to the piston side of the illustrated embodiment.

Since the present invention is constructed as described above, when the clutch 3 is rotating, the check valve 11 (the valve opening force Fl based on the self-sufflating force of the moss leaf spring 13 and the mass 15 due to the centrifugal force) When the line pressure Pl is supplied to the hydraulic chamber 9, a centrifugal force acts on the hydraulic fluid in the hydraulic chamber 9, which causes the leaf spring 13 to act on the valve opening force Fm. Valve closing force Ff
cause

The valve opening force Fm acting on the mass 15 due to the command force and the valve closing force Ff based on the centrifugal force of the hydraulic oil are approximately equal, that is, F f :
If the mass 15 is selected so that Fm, then when the force Fp due to the hydraulic pressure applied from the line pressure P7 in the hydraulic chamber 9 becomes larger than the opening/closing force FV due to the spring force of the leaf spring 13, that is, Fp> The check valve 11 closes immediately when Fl becomes Fl, and thus the opening/closing force Fl due to the leaf spring's own spring force
By selecting , the clutch piston 7 can be operated quickly even if the hydraulic pressure in the hydraulic chamber is low, and the line pressure PA
When Pl=O, leaf spring 13
Since the valve opening force acting on the leaf spring 13, ie, FV+Fm, is greater than the valve closing force, ie, Ff, acting on the leaf spring 13, the leak hole 12 is opened by the force of the leaf spring.

As described above, according to the present invention, in the leaf spring type check valve provided in the hydraulic operating chamber of the hydraulic clutch, the leaf spring receives centrifugal force and applies a force in a direction that promotes the opening force of the spring. Since the centrifugal force due to the residual oil in the hydraulic chamber is offset by the centrifugal force exerted by the mass, the valve opening force due to the leaf spring's own spring force can be reduced, resulting in low speed. Reliable operation can be obtained even at rotational speeds and low operating oil pressure.This eliminates the need for a larger hydraulic pump, and there is no fluctuation due to a drop in oil pressure due to leaks, allowing the oil pressure in the hydraulic chamber to rise at a fixed level from a low pressure. This eliminates shift shock and eliminates unnecessary drag, which helps improve durability.Furthermore, when a stopper is provided to restrict the movement of the leaf spring in the opening direction, the stopper is connected to the leaf spring. Since the gap between the leak holes can be narrowed, the closing force of the leaf spring that tries to close due to the negative pressure generated on the side of the leaf spring due to the flow of hydraulic oil leaking from the leak hole is reduced instantly. This makes it easier to close the leak hole at the start of operation, and when the mass is accommodated in the recess provided in the piston, the clutch can be formed compactly without increasing the dimensions of the clutch due to the provision of the mass. .

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is a longitudinal sectional view, Fig. 2 is a sectional view showing another embodiment of the main part, and Fig. 3 shows still another embodiment of the main part. Cross-sectional view, Figure 4 is A of Figure 1.
-A line arrow view. 1... Drive shaft, 2... Driven shaft, 3...
...Oil field operating clutch, 9...Hydraulic operating chamber, 11...Check valve, 13...
Leaf spring, 15...mass.

Claims (1)

[Scope of Claims] 1. A leaf spring-type check valve is provided in a hydraulic chamber of a hydraulically operated clutch that engages and disengages a drive shaft and a driven shaft, in which the leaf spring is applied with a centrifugal force to cause the spring to open. A check valve for an oil field operating clutch characterized by having a mass that promotes valve force. 2. The leaf spring is arranged in the radial direction of the hydraulic chamber and is fixed to the chamber wall at its inner end. A check valve for a hydraulically operated clutch according to claim 1, wherein the mass is fixed to the outer end of the leaf spring. 3. The check valve for an oil field operated clutch according to claim 2, wherein a stopper is provided in the hydraulic operation chamber to restrict movement of the leaf spring in the opening direction due to centrifugal force. 4. The check valve for a hydraulically operated clutch according to claim 2, wherein the leaf spring is provided on the piston side of the hydraulically operating chamber, and four parts for accommodating mass are provided on the piston side.