JPH02275123A - Hydraulic power transmission coupling - Google Patents

Abstract

PURPOSE:To obtain a power transmission coupling having such transfer torque character that may satisfy required performance of a vehicle by collecting delivery fluid into one chamber, and providing a hydraulic pressure detecting mechanism moving in accordance with pressure and changing a sectional area of a variable orifice in a delivery passage therefrom. CONSTITUTION:A plunger 5 is housed into a plunger chamber 4 formed in a rotor 2, and oil generated by the plunger 5 on account of relative rotation of a cam housing 1 and the rotor 2 is collected in a main passage 7 via a delivery passage 8 and a delivery valve 10. An orifice valve 14 is movably housed into the main passage 7 via a pressure setting spring 11, a needle valve 17 fixed to the rotor 2 is inserted into the hole thereof for constituting a variable orifice mechanism, oil inflow rate into a low pressure chamber 16 communicated to an inlet passage 19 is changed, and reaction of the plunger 5 is changed. Thereby torque character variously varying in accordance with transfer torque can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydraulic power transmission joint used for distributing driving force in a vehicle.

[Prior Art] Examples of conventional vehicle hydraulic power transmission joints include the following.

That is, this hydraulic power transmission joint includes a first rotating member that is formed integrally with one of the input/output shafts and has a cam surface on the inner circumference, and a first rotating member that is formed integrally with the other input/output shaft and has a cam surface on the inner circumference. a second rotating member inserted into the second rotating member; a cam body that is supported by the second rotating member and slides on the cam surface and reciprocates in the radial direction when the two rotating members rotate relative to each other; and a reciprocating motion of the cam body. The fluid chamber is provided with a plurality of fluid chambers whose volume changes as the fluid moves, and a fluid path formed in the second rotating member and connecting the fluid chambers via an orifice (see Japanese Patent Laid-Open No. 62-286838).

[Problems to be Solved by the Invention] In such a conventional hydraulic power transmission joint, the transmission torque T is equal to 2 of the rotational speed difference ΔN as shown in FIG.
The torque characteristic is proportional to the power of the joint, and the torque transmission characteristic is determined by the orifice specific to the joint. Therefore, it may not always be suitable for distributing driving force in a vehicle.

For example, the left and right wheels 51.5 driven as shown in FIG.
When this joint 53 is used between the left and right wheels 51.5
Since a sudden change in torque occurs in response to a difference in rotational speed between the two, there is a problem in that the vehicle undergoes a sudden change in behavior, resulting in a reduction in safety.

In addition, the front and rear wheels of a four-wheel drive vehicle as shown in Fig. 8 are 54.5
When the joint 53 is used to distribute the driving force between 5.51.52, on slippery roads, the difference in rotational speed of the joint may become excessive and the temperature of the joint becomes too high, or excessive slippage of the drive wheels may cause There were problems such as reduced running performance.

Regarding this problem, the applicant has proposed a mechanism that closes the orifice and locks the joint when the transmitted torque exceeds a predetermined value, but the torque characteristics in the process of locking the joint are unique to the orifice. There was a problem that this characteristic did not necessarily match the required performance of the vehicle.

The present invention has been made in view of these conventional problems, and provides a hydraulic power transmission joint that has transmission torque characteristics that meet performance requirements that vary depending on the location of use of the joint and the characteristics of the vehicle. It is intended to.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a flow rate system that is provided between input and output shafts that are relatively rotatable, and that flows an amount of fluid according to the rotational speed difference between the two shafts. In a torque transmission joint that includes a generating means and a means for generating flow resistance of the fluid, and in which the transmission torque between the input and output shafts is controlled by the flow resistance of the fluid, the discharged fluid is collected in one room. In addition, a hydraulic pressure detection mechanism that moves according to the discharge pressure and a variable orifice mechanism that changes the cross-sectional area of the orifice by movement of the hydraulic pressure detection mechanism are provided in the discharge path from the chamber.

[Function] In the present invention, the discharge fluid is stored in one room (high pressure chamber).
In addition, a hydraulic pressure detection mechanism that moves according to the discharge pressure (pressure in the high pressure chamber) and a variable orifice mechanism that changes the orifice cross-sectional area by the movement of the hydraulic pressure detection mechanism are provided in the discharge path from the chamber. By providing this, the following effects can be obtained.

In other words, the transmitted torque is proportional to the discharge pressure, and the torque characteristics are determined by the cross-sectional area of the orifice. Therefore, by appropriately designing the movement characteristics of the detection mechanism with respect to the oil pressure and the change characteristics of the orifice cross-section with respect to the movement of the detection mechanism, the joint It is possible to obtain a hydraulic power transmission joint that has transmission torque characteristics that meet different performance requirements depending on the location of use and the characteristics of the vehicle.

[Example] Embodiments of the present invention will be described below based on the drawings.

1 to 6 are diagrams showing a first embodiment of the present invention.

First, to explain the configuration, in FIGS. 1 and 2, 1 is a cam housing with a cam surface IA formed on its inner surface, and the cam housing 1 is connected to an input shaft or an output shaft, and It rotates as one.

A rotor 2 is rotatably housed in the cam housing 1. The rotor 2 is connected to an output shaft or an input shaft, and rotates integrally with the output shaft or input shaft. Note that 3 is an oil seal interposed between the cam housing 1 and the rotor 2.

A plurality of plunger chambers 4 are formed in the rotor 2 in the axial direction, and a plurality of plungers 5 are slidably housed in the plunger chamber 4 via a return spring 6.

Further, a main passage 7 is formed in the center of the rotor 2, and the main passage 7 and the plunger chamber 4 communicate with each other via a discharge passage 8. A discharge valve ] 0 is interposed in the discharge passage 8 by a return spring 9 to allow oil to flow in one direction.

As a result, the plurality of plunger chambers 4 in the discharge stroke
All the discharge fluid collects in the main passage 7.

An orifice valve 14 as a hydraulic pressure detection mechanism is movably housed in the main passage 7 via a pressure setting spring 11, and a needle valve 17, which is fixed and does not move, is inserted into a hole in the orifice valve 14 to adjust the pressure. It constitutes an orifice mechanism.

This variable orifice mechanism defines a high pressure chamber 15 on one side of the main passage 7 and a low pressure chamber 16 on the other side.

When the discharge pressure P of the high pressure chamber 15 acts on the orifice valve 14, a force F that is the product of the pressure receiving area S of the orifice valve 14 and the discharge pressure P acts on the orifice valve 14.

F=PXS This acting force F is the setting load P1 of the pressure setting spring 11
, the orifice valve 14 moves to the right,
Move to a position where the spring load and acting force F are balanced.

This relationship is shown in FIG.

Since the needle valve 17 is tapered, the cross-sectional area of the orifice changes as the orifice valve 14 moves.

In the first embodiment, the orifice cross-sectional area is set to increase as the discharge pressure increases.

Further, an oil circulation groove 18 is formed at an intermediate position of the plunger chamber 4 on the outer diameter of the rotor 2 (see FIG. 2), and the low pressure chamber 16 and the suction passage 19 communicate with each other through the oil circulation groove 18. However, the suction passage 19 communicates with the plunger chamber 4 via a suction valve 20, which will be described later. Therefore, the oil circulates around the outer diameter side of the rotor 2.

21 is a piston, 22 is a holding member, and the piston 21
A return spring 23 is interposed between the holding member 22 and the holding member 22 . Further, a relief valve 26 is provided in a passage 24 that communicates the high pressure chamber 15 and the low pressure chamber 16 with a spring 25 to prevent excessive torque.

Reference numeral 27 indicates a shutoff valve provided at an outlet for discharging oil from the high pressure chamber 15, 28 indicates a shutoff valve provided at an inlet for filling oil, and 29 indicates a shutoff valve provided at an outlet for discharging oil. This is a shut-off valve.

In addition, 30 is an oil seal, 31 is a stop ring, 3
2 is a thrust washer, and 33 and 34 are mounting holes for input and output shafts.

Next, I will explain the effect.

When there is no difference in rotation between the cam housing 1 and the rotor 2, the plunger 5 does not operate and no torque is transmitted.

Next, when a rotation difference occurs between the cam housing 1 and the rotor 2, the plunger 5, which is in the discharge stroke, is pushed in the axial direction by the cam surface IA of the cam housing 1.

Therefore, the plunger 5 pushes out the oil in the plunger chamber 4 from the discharge passage 8 to the high pressure chamber 15 via the discharge valve 10, and the suction valve 2o closes the suction passage 19. The oil pushed out into the high pressure chamber 15 is supplied to the low pressure chamber 16 through the variable orifice 13. At this time variable orifice 1
Due to the resistance 3, the hydraulic pressure in the high pressure chamber 15 and the plunger chamber 4 increases, and a reaction force is generated in the plunger 5. By rotating the cam housing 1 against this plunger reaction force, torque is generated, and the cam housing 1 and rotor 2
Torque is transmitted between.

Furthermore, when the cam housing 1 rotates, the plunger 5 enters the suction stroke, and the oil in the low pressure chamber 16 is sucked into the plunger chamber 4 via the oil circulation groove 18, the suction passage 19, and the suction valve 20, and the plunger 5 enters the suction stroke. Return along the cam surface IA of the cam housing 1.

Here, as shown in FIG. 4, when the discharge pressure P is below the predetermined value P1, the force F acting on the orifice valve 14 is smaller than the set load of the pressure setting spring 11, so the orifice valve 14 does not move. At this time, the cross-sectional area of the orifice created by the needle valve 17 is small, and the torque characteristics
The characteristics are as shown in A in FIG.

Next, when the discharge pressure P reaches the predetermined discharge pressure P2, the drain valve 14 moves to the right by ΔT, as shown in FIG. In this case, the cross-sectional area of the orifice formed by the needle valve 17 is of a medium size, and the torque characteristics are as shown in B in FIG. 6.

Next, when the discharge pressure P exceeds the predetermined discharge pressure P3, the orifice valve 14 further moves to the right, and the cross-sectional area of the orifice formed by the needle valve 17 increases. The torque characteristics in this case are as shown in C in FIG.

In this way, in the torque range where sudden torque changes greatly affect the behavior of the vehicle, it is possible to set the transmitted torque T to change gradually with respect to the rotational speed difference ΔN, thereby improving the stability of the vehicle. be able to.

Next, FIGS. 10 to 12 show a second embodiment of the present invention.

10 and 11, reference numeral 35 is a needle valve constituting a variable orifice mechanism, and a stepped portion 36 with a different diameter is formed at the tip of the needle valve 35, and a stopper portion 37 is connected to the needle valve 35. A hole 38 is formed. Orifice valve 391 into which needle valve 35 is inserted. :t, a stepped portion 40 is formed, and a variable orifice 4 is formed between the orifice valve 39 and the needle valve 35.
1 is formed. In FIG. 10, 11 indicates a pressure setting spring.

Therefore, as shown in FIG. 12, the characteristic A, the characteristic B via C, and the characteristic D as a substitute for the relief mechanism are obtained depending on the rotational speed difference ΔN.

Next, FIG. 13 is a diagram showing a third embodiment of the present invention.

In FIG. 13, 42 is a needle valve that functions as an oil pressure detection mechanism, and the needle valve 42 forms a variable first orifice 44 between it and the communication hole 43 of the rotor 2. 11 is a pressure setting spring.

When the discharge pressure P of the high pressure chamber 15 acts on the needle valve 42, the needle valve 42 moves, and as the needle valve 42 moves, the orifice cross-sectional area changes, and when the discharge pressure P exceeds a predetermined value, the variable orifice 44 moves. Closed and locked.

In this embodiment, since the second cylinder 42 also has the function of an oil pressure detection mechanism, the entire apparatus can be made smaller.

Next, FIGS. 14 and 15 are diagrams showing a fourth embodiment of the present invention.

In FIGS. 14 and 15, 45 is a two-needle valve, and this needle valve 45 is inserted into the rotor 2 and fixed thereto. 46 is a communication hole formed in the rotor 2 (see FIG. 15).

A diaphragm 47 functions as an oil pressure detection mechanism, and a variable orifice 49 is formed between a hole 48 formed in the diaphragm 47 and the needle valve 45.

When the discharge pressure P of the high pressure chamber 15 acts on the diaphragm 47, the diaphragm 47 deforms and the orifice cross-sectional area changes. When the discharge pressure P exceeds a predetermined value, the variable orifice 4
9 is closed and becomes locked.

In the first to third embodiments, if the gap between the sliding part between the orifice valve and the rotor 2 was clogged with foreign matter, the movement of the orifice valve deteriorated, resulting in unstable torque characteristics. In this example, such a problem can be overcome.

Note that the present invention is applicable not only to axial plunger type pumps but also to radial plunger type pumps.

[Effects of the Invention] As described above, according to the present invention, a collecting means for collecting the discharged fluid in one room (high pressure chamber) is provided, and a discharge passage from the room is provided with a collection means for collecting the discharge fluid in one room (high pressure chamber). The following effects can be obtained by providing an oil pressure detection mechanism that moves according to the pressure (pressure) and a variable orifice mechanism that changes the cross-sectional area of the orifice as the oil pressure detection mechanism moves.

That is, since the transmitted torque is proportional to the discharge pressure and the torque characteristic is determined by the orifice cross-sectional area, by appropriately designing the movement characteristics of the detection mechanism with respect to the oil pressure and the change characteristics of the orifice cross-section area with respect to the movement of the detection mechanism,
It is possible to obtain torque characteristics that vary in various ways depending on the transmitted torque.

This makes it possible to provide a hydraulic power transmission joint that has transmission torque characteristics that satisfy performance requirements that vary depending on the location of use of the joint and the characteristics of the vehicle.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing one embodiment of the present invention, Fig. 2 is another sectional view, Fig. 3 is a graph showing spring characteristics, Figs. 4 and 5 are explanatory diagrams of each main part, Fig. 6 Figure 7 is a graph showing torque characteristics, Figure 7 is a diagram showing a conventional application example, Figure 8 is a diagram showing another conventional application example, Figure 9 is a graph showing conventional torque characteristics, and Figure 10 is a graph showing conventional application examples. 11 is a diagram showing a part of the stopper; FIG. 12 is a graph showing torque characteristics; FIG. 13 is a main part showing a third embodiment of the invention. 14 is a cross-sectional view of a main part showing a fourth embodiment of the present invention, and FIG. 15 is a view showing a communication hole of a rotor. In the figure, 1...Cam housing, IA...Cam surface, 2...Rotor, 3...Oil seal, 4...Plunger chamber, 5...Plunger 6...Return spring, 7... Main passage, 8... Discharge path, 9... Return spring, 10... Discharge valve, 11... Pressure setting spring, 13.41, 44.49... Variable orifice, 14 ．．
39... Orifice valve, 15... High pressure chamber, 16... Low pressure chamber, 17.35.42.45... Needle valve, 18.
...Oil circulation groove, 19...Suction path, 20...Suction valve, 21...Piston, 22...Holding member, 23...Return spring, 24...Passage, 25... Spring, 26... Relief valve, 27.28.29... Closing valve, 30... Oil seal, 31... Stop ring, 32... Thrust washer, 33.34... Mounting hole, 36.40...Step part, 37...Part of stopper, 38.43.46...Communication hole, 47...Diaphragm, 48...hole. Patent applicant: Fuji Iron Works Co., Ltd.

Claims (1)

[Scope of Claims] A flow rate generating means provided between input and output shafts that are relatively rotatable, and causing a flow of fluid in an amount corresponding to a rotational speed difference between the two shafts, and a means for generating flow resistance of the fluid. In the torque transmission joint in which the transmission torque between the input and output shafts is controlled by the flow resistance of the fluid, a collection means for collecting the discharged fluid in one chamber is provided, and a discharge path from the chamber is provided with a discharge pressure. 1. A hydraulic power transmission joint comprising: a hydraulic pressure detection mechanism that moves according to the hydraulic pressure detection mechanism; and a variable orifice mechanism whose orifice cross-sectional area changes according to the movement of the hydraulic pressure detection mechanism.