JPH01188721A - Clutch - Google Patents

Abstract

PURPOSE:To produce a compact clutch unexpensively by mounting both a pump part which sucks and discharges fluid by the cam effect which functions according to the relative turning action between two members receiving and transmitting torque and a flow rate control part which limits the intake amount and permits discharge according to the operation variable of a clutch. CONSTITUTION:During the inoperative period of a clutch, a flow control valve 18 permits intake action of a pump part 7 and inhibits the discharge action thereof. Each pump plunger 10 may freely execute the intake stroke by the load of a spring 12, however, is not able to execute the discharge stroke by the force of a cam face 5a. The plunger 10 is therefore engaged in the turning direction with respect to the cam face 5a to drive a cam ring 5 and a flange 8 in engagement with each other, whereby causing the clutch engagement between an engine crank shaft 1 and a transmission input shaft 2. During the operating period of the clutch, a valve 18 limits the intake action of the pump part 7 and allows the pump-out operation freely. Such clutch operation is executed against the load of a return spring 18a.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a latch useful for connecting and disconnecting power between an engine and a transmission of an automobile.

(Prior Art) As this type of clutch, it is customary to use a so-called dry single-plate clutch.

(Problem to be solved by the invention) However, with a dry single-plate clutch, the clutch operation is performed against a large spring force to maintain the clutch engagement state, so a large operating force is required, and the clutch operation stroke is large. Combined with this, this leads to driver fatigue.

Therefore, it has been proposed to use a fluid clutch as a substitute, as seen in Japanese Unexamined Patent Publication No. 61-189329, but this fluid clutch is expensive and large, and is disadvantageous in terms of cost and space.

(Means for Solving the Problems) The present invention attempts to solve the above-mentioned problems by providing a novel latch, which uses a cam action according to the relative rotation between two members to transfer torque. It is characterized by a clutch structure that includes a pump section that sucks in and discharges fluid, and a flow rate control section that limits the suction and allows the discharge depending on the amount of clutch operation.

By the way, the pump part consists of a plunger that is slidably fitted into one of the two members to which torque is to be transferred, a cam surface set on the other of the two members, and an elastic member that urges the plunger toward the cam surface. It can be composed of means.

Further, the flow rate control section sets the clutch engagement position to allow the above-mentioned suction and prohibit the above-mentioned discharge when the clutch is not operated, and to allow the above-mentioned suction during clutch operation and gradually release the prohibition of the above-mentioned discharge as the amount of clutch operation increases. The flow control valve can be configured with a flow control valve having a half-clutch position and a clutch cut-off position that prohibits the suction and allows the discharge while the clutch is fully operated.

It is also preferable to insert a rectifier between the pump section and the flow rate control section so that the pump section communicates with the suction port of the flow rate control section during suction and through the discharge port of the flow rate control section during discharge.

Note that it is advantageous to provide a plurality of pump sections and to connect the pump sections that perform suction and discharge in the same phase to the flow rate control section through a common circuit.

(Function) When the clutch is not operated, the flow rate control section allows the pump section to suck in and prohibits discharge. Therefore, when the pump section sucks in and discharges fluid by a cam action corresponding to the relative rotation between the two members that are to transfer torque, the pump section can freely suck in fluid, but cannot discharge it. Therefore, the pump part eliminates the above-mentioned cam action and enters a locked state in which the two members are rotationally engaged, thereby achieving a clutch engaged state in which power is transferred between these two members.

During clutch operation, the flow control section restricts suction from the pump section and allows discharge according to the amount of operation, and when fully operated, the flow control section prohibits suction from the pump section and allows discharge to occur freely. Become.

Therefore, the engagement force of the pump part is gradually reduced to the part that performs the cam action, and a half-clutch state that restricts the transfer of power between the two members can be obtained, and eventually the pump part becomes the part that performs the cam action. In contrast, it is possible to obtain a clutch disengaged state in which the clutch is in a free state and no power is transferred between the two members.

By the way, the clutch operation described above is performed against the return spring of the clutch operating member, so the operating force is small, and this also eliminates the need to increase the clutch operation stroke, which reduces driver fatigue. can be reduced.

(Example) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

1 to 3 show an embodiment of the clutch of the present invention, where l indicates an engine crankshaft and 2 indicates a transmission input shaft, and the clutch of this embodiment is arranged between the crankshaft 1 and the transmission input shaft 2. The clutch housing 3 is constructed such that it can be connected and disconnected, and is housed in the clutch housing 3.

A flywheel 4 is coupled to a crankshaft 1, and a cam ring 5 is fitted to a transmission input shaft 2 so as to be relatively rotatable.

The flywheel 4 and the cam ring 5 are then drivingly connected via a well-known torsional damper 6 such as a dry single plate clutch.

The cam ring 5 is a pump member 7 that constitutes the main part of the present invention.
It fits into the transmission input shaft 2 so as to straddle the flange 8 integrally formed on the transmission input shaft 2. Inside the cam ring 5 is a cam surface 5 that surrounds the outer peripheral surface of the flange 8.
a to define a chamber 9 between it and the outer peripheral surface of the flange 8, and the cam surface 5a is symmetrical with respect to a single plane passing through the axis of the flange 8, as shown in FIG.

The flange 8 is further formed with a plurality of radial blind holes 8a opening on its outer peripheral surface, and these holes are arranged symmetrically with respect to the center line of the flange 8. Plunger 10 in each blind hole 8, a
are slidably fitted to define a pump chamber 11, and each plunger 10 is pressed against the cam surface 5a by a spring 12. At this time, in order to reduce Hertzian stress and wear, the tip of the plunger 10 has a radius of curvature of R2 in the central region α, as shown in FIG.
do. The plunger 10 is moved forward and backward by the cam surface 5a during relative rotation of the cam ring 5 and the flange 8, and performs a pumping action to suck hydraulic oil into the chamber 11 and discharge hydraulic oil from the chamber 11. The cam ring 5 is formed with a recess 5b through which hydraulic oil is transferred, and a recess 5c through which hydraulic oil is transferred to and from the chamber 9.

The recesses 5b associated with the pump chamber 11 that performs suction and discharge in the same phase are connected to the oil passages 54 and 5e, and the recess 5c is connected to the oil passage 5f. Also, oil passage 5d.

5e and 5f are connected to circuits 14 to 16 via fixed couplers 13.

The circuit 14 connects the flow control valve 1 via check valves 17a and 17b.
8 discharge port E and suction port! and connect to circuit 15
is connected to the discharge port E and suction port 1-1 of the flow control valve 18 via the check valves 17c and 17d, and the check valve 17a-
17b constitutes the rectifying section 17. The circuit 16 is connected to a suction circuit 19 that communicates with the suction port T of the flow control valve 18, and the 0 circuit 19 provided by connecting the discharge circuit 20 to the discharge port C of the flow control valve 18 leads directly into the reservoir tank 21. , the circuit 20 leads to a reservoir tank 21 via an oil cooler 22. Also, the discharge port E is the relief valve 2.
It is also connected to a relief circuit 24 having 3.

As shown in FIG. 3, the flow control valve 18 is normally operated by a spring 1.
8a to the position shown in FIG. 3(a) and the discharge port) E.
C is cut off, and suction ports T and 1 are communicated with each other.

During clutch operation by depressing the clutch pedal 25, the spool 18b is pushed in as shown in FIG.
, C is increased according to the amount of clutch operation. For this purpose, the discharge port C is designed as shown in Fig. 3(d).
The spool is elongated in the axial direction. At the maximum pushing limit of the spool 18b due to the maximum depression of the clutch pedal 25, the suction ports T and 1 are cut off, and the discharge port C is fully open and communicates with the discharge port E, as shown in FIG. 3(C).

The operation of the above embodiment will be explained next.

First, the discharge rate and suction rate of hydraulic oil by the pump plunger IO (discharge amount and suction amount with respect to the relative rotation angle between the cam ring 5 and the flange 8) will be explained when the flow of hydraulic oil to and from the pump chamber 11 is not restricted at all. Fifth
The horizontal axis in the figure indicates the relative rotation angle when the flange 8 rotates relative to the cam ring 5 in the direction of the arrow in FIG. 2, and the pair of plungers lO in the left and right direction in FIG. The ejection rate and suction rate are changed as shown at 10a. The pair of plungers 1O located at the upper right and lower left in FIG. 2 each exhibit a characteristic in which the phase is 60 @ ahead of the solid line 10a, as shown by the dotted line 10b in the middle of FIG.
A pair of plungers 10 located at the upper left and lower right in Fig. 2
As shown by the dashed-dotted line 10c in FIG. 5, each exhibits a characteristic in which the phase lags the solid line 10a by 60@. Therefore, the sum of these three characteristics is the same at any relative rotation angle.

When the clutch pedal 25 is released and the clutch is not operated, the flow control valve 18 is in the state shown in FIG. 3(a) and the suction port T is closed.
, 1 are communicated with each other, and discharge ports E and C are blocked off. Therefore, each pump plunger 10 can freely perform a suction stroke using the spring 12, but cannot perform a discharge stroke using the cam surface 5a. Therefore, the plunger 10 has a cam surface 5
a in the rotational direction, drivingly engages the cam ring 5 and the flange 8, and enables clutch engagement between the engine crankshaft 1 and the transmission input shaft 2.

While depressing the clutch pedal 25, the flow control valve 18
In the state shown in FIG. 3(b), the suction ports T and 1 are kept in communication, but the degree of communication between the discharge ports 8.0 and 8.0 is adjusted according to the amount of depression of the clutch pedal. Therefore, each plunger 10 can freely carry out the suction stroke by the spring 12, but allows the discharge stroke by the cam surface 5a at a speed depending on the degree of communication between the discharge ports E and C, that is, the clutch operation amount. Therefore, each plunger 10 has a cam surface 5a.
During this time, power can be transmitted between the cam ring 5 and the flange 8, and a half-clutch state can be obtained by following this cam surface while being restricted from being pushed in by the cam ring. In addition, in this half-clutch state, even if the clutch pedal is depressed at the same clutch pedal depression position, as the engine speed increases and the pushing frequency of plunge''+10 increases, the clutch engagement force increases, making it impossible to obtain clutch characteristics equivalent to a fluid clutch. can.

When the clutch pedal 25 is fully depressed, the flow control valve 1
8 is in the state shown in FIG. 3(C), and the suction port T is in the state shown in FIG.

1, and the discharge port C communicates with the discharge port E in a fully open state. Therefore, although each plunger 10 can freely perform a discharge stroke using the cam surface 5a, the spring 1
It becomes impossible to perform the suction stroke according to 2, separates from the cam surface 5a, and power cannot be transferred between the cam ring 5 and the flange 8, resulting in a clutch disengaged state.

Note that the rise of the transmitted torque at the time of switching from the clutch disengaged state to the clutch engaged state in which the clutch pedal 25 is released can be made smooth by the well-known function of the torsional damper 6, and the shock can be reduced.

Also, in case of a shock that cannot be alleviated even with this, the pressure at the discharge port E, which becomes abnormally high at this time, is removed by the relief valve 2.
3, the rotation can be absorbed through the relative rotation between the cam ring 5 and the flange 8.

In the illustrated example, the cam surface 5a and the plunger 10 are arranged in the radial direction, but it goes without saying that they may be arranged in the axial direction.

(Effects of the Invention) Thus, with the configuration of claim 1, the clutch of the present invention performs clutch operation against only the return spring 18a of the member for that purpose (clutch pedal 25 in the illustrated example), and the clutch operation force is small. Therefore, there is no need to increase the clutch operation stroke, and the fatigue of clutch operation can be reduced.

Further, according to the configurations of claims 2 and 3, since the fluid device is of a positive displacement type, the pump member 7 and the flow control section (in the illustrated example, the flow control valve 1
8) can be made simple, inexpensive, and compact, which is more advantageous than the conventional solution using a fluid clutch.

Furthermore, when the rectifier 17 is provided as in claim 4, the flow rate controller 18 can obtain a predetermined effect even when the torque transmission direction is reversible, and the pump section can be Even when the pump is configured with several pumps, only one flow rate control section 1B is sufficient.

Furthermore, when the pump section is constituted by a plurality of pumps as in claim 5, the torque transmission capacity of the clutch increases, resulting in a clutch that can be used in a transmission system that transmits large torque.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing one embodiment of the clutch of the present invention, Fig. 2 is a cross-sectional view of the pump section of the same embodiment, and Fig. 3 shows the specific structure of the flow control valve in the same embodiment. a)～
(C) is a longitudinal cross-sectional view for explaining its function, (d) is a cross-sectional view of the discharge port, Fig. 4 is a partial view showing the tip shape of the pump plunger in the same example, and Fig. 5 is a diagram of the pump part in the same example. It is a phase characteristic diagram. l...Crankshaft 2...Transmission input shaft 4
...Flywheel 5...Cam ring 5a.
...Cam surface 6...Torsional damper 7...Pump part 8...
・Flange 10...Plunger 12...
・Spring 17... Rectifying section 18... Flow rate control valve (flow rate control section) 19... Suction circuit 20... Discharge circuit 2
3... Relief valve 25... Clutch pedal patent applicant Nissan Motor Co., Ltd. Fig. 2 qpi■ Fig. 3 Fig. 4

Claims (1)

[Scope of Claims] 1. A pump section that sucks in and discharges fluid by a cam action according to the relative rotation between two members to which torque is to be transferred; A clutch comprising: a flow rate control section that allows 2. The pump section is configured with a plunger slidably fitted into one of the two members, a cam surface set on the other of the two members, and an elastic means for biasing the plunger toward the cam surface. Clutch according to claim 1. 3. A clutch engagement position where the flow rate control section allows the suction and prohibits the discharge while the clutch is not operated;
The clutch has a half-clutch position in which the suction is allowed during clutch operation and the prohibition of the discharge is gradually released as the clutch operation amount increases, and a clutch disengaged position in which the suction is prohibited and the discharge is permitted during full clutch operation. The clutch according to claim 1 or 2, which is a flow control valve. 4. A rectifying section is provided between the pump section and the flow control section, which communicates the suction pump section of the pump section with the suction port of the flow control section, and the discharge pump section of the pump section with the discharge port of the flow control section. A clutch according to any one of claims 1 to 3. 5. The clutch according to any one of claims 1 to 4, wherein the pump section is composed of a plurality of pumps, and the pumps that perform suction and discharge in the same phase are connected to the flow rate control section through a common circuit.