JPH03189426A - Control type rotation difference sensitive coupling - Google Patents

Abstract

PURPOSE:To improve the durability and reliability of a seal member and reduce the slide resistance of a spool by making the opening area of an orifice variable with the spool land of the spool at the side of an accumulator, and providing the seal member on a spool land at an opposite side. CONSTITUTION:When a spool 120 is stroked with a stepping motor 180 in changing transmission torque characteristics, the opening area of an orifice 100 governing a flowing restriction effect is changed with a relative position between the spool 120 and the orifice 100. In the aforesaid transmission torque change control, the orifice 100 is opened and closed with the first spool land 123 formed with an annular groove 121 at the side of an accumulator chamber 90. Pressure in an oil passage continuous to the orifice 100, therefore, acts on the first spool land 123, and only pressure in the accumulator chamber 90 continuous to the side of the second spool via an oil passage within the spool 120 acts on the side of the second spool land 124 having seal members 126 and 127.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is a control type device used as a drive force distribution device of a multi-wheel drive vehicle such as a four-wheel drive vehicle, a differential limiting device between front and rear wheels, left and right wheels, etc. Related to improvement of rotation difference sensitive joints.

(Prior art) As a conventional control type rotation difference sensitive joint, Japanese Patent Application Laid-Open No. 63-1
A joint as described in the publication No. 01567 is known.

This conventional source includes a first rotating shaft and a second rotating shaft that are coaxially arranged so as to be relatively rotatable, and a fluid that is discharged according to the relative rotational speed difference between the first and second rotating shafts. The figure shows a rotation differential sensitive joint that converts the flow rate into fluid pressure through outflow regulation using an orifice, and further converts this fluid pressure into transmission torque between both shafts, and a spool that strokes in the axial direction driven by an actuator. The orifice opening area is changed depending on the relative positional relationship between the driven spool and the orifice.

(Problem to be Solved by the Invention) However, in such a conventional control type rotation difference sensitive joint, the orifice opening area is changed depending on the relative positional relationship between the accumulator chamber side end surface of the spool and the orifice. Therefore, as shown in Figure 10, near the closing of the orifice where the pressure in the oil passage from the cylinder chamber becomes high due to outflow regulation, this high pressure is transferred from the orifice to the outer circumferential surface of the sprue and the inner wall of the rotor's spool chamber. The pressure is directly transmitted to the seal groove through the gap, and the inside of the seal groove where the O-ring and slipper seal are provided becomes high pressure.

As a result, the pressure difference between the front and back of the seal portion increases, which increases leakage from the seal portion and also reduces the durability and reliability of the seal member.

In addition, the slipper seal is pressed against the spool by the pressure within the seal groove, increasing the force that moves the spool in the axial direction, and as a result, an actuator with high torque performance is required as an actuator for operating the spool.

The present invention has been made with attention to the above-mentioned problems, and is intended to reduce leakage from the seal portion of the spool and to reduce leakage from the seal member in a controlled rotation differential sensitive joint in which the opening area of the orifice can be changed by an external actuator. The objective is to improve durability and reliability while reducing the sliding resistance of the spool.

(Means for Solving the Problems) In order to solve the above problems, in the controlled rotation difference sensitive joint of the present invention, the orifice opening area is changed in the spool land on the accumulator chamber side, which is formed by an annular groove provided in the spool. Thus, a sealing member was provided on the spool land portion on the opposite side from the accumulator chamber.

That is, a first rotating shaft and a second rotating shaft are coaxially arranged so as to be relatively rotatable; A rotation difference sensitive joint that converts the flow rate discharged according to the relative rotational speed difference of the second rotating shaft into fluid pressure through outflow regulation using an orifice, and further converts this fluid pressure into a transmission torque between the two shafts; An annular groove that is disposed at the orifice position and can communicate with the orifice is formed on the outer periphery, and the annular groove communicates with the accumulator chamber through an oil path inside the spool, and a first spool on the accumulator chamber side formed by the annular groove. The orifice is opened and closed by a land, and includes a spool provided with a sealing member on the second spool land side opposite to the accumulator chamber, and orifice opening area changing means for stroking the spool by an external actuator. characterized by things.

(Function) When a relative rotation speed difference occurs between the first rotation shaft and the second rotation shaft, the flow rate discharged according to the relative rotation speed difference is converted into fluid pressure by outflow regulation by the orifice. , Furthermore, this fluid pressure is converted into a transmission torque between both shafts.

When changing this transmission torque characteristic, when the spool is stroked by an external actuator, the orifice opening area, which determines the outflow regulating effect, is changed depending on the relative positional relationship between the spool and the orifice.

In this transmission torque change control, since the orifice is opened and closed by the first spool land on the accumulator chamber side formed by the annular groove, the pressure of the oil passage communicating with the orifice acts on the first spool land, Only the accumulator chamber pressure communicated via the oil passage inside the spool acts on the second spool land side opposite to the accumulator chamber where the seal member is provided.

Therefore, even when the orifice is close to its closed position, where the pressure in the oil passage communicating with the orifice becomes high, only the low pressure in the accumulator chamber is applied to the seal portion.

(Example) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First, the configuration will be explained.

FIG. 7 is a schematic diagram showing the power train and differential limiting control system of a rear wheel drive vehicle to which the controlled rotation difference sensitive joint A of the embodiment is applied. ,
It is installed between RW and used as a differential limiting device with a built-in differential differential.

In FIG. 7, reference numeral 180 is a stepping motor that changes the differential limiting torque characteristic of the controlled rotation difference sensitive joint A, and this stepping motor 180 is driven and controlled by the controller 200.

This controller 200 includes a vehicle speed sensor 20.
1. Right rear wheel rotation sensor 202, left rear wheel rotation sensor 203
, a steering angle sensor 204, an accelerator opening sensor 205, a brake switch 206, etc. are connected, and these sensor signals are used as input information to adjust the differential limiting torque characteristics according to the rotational speed difference between the left and right rear wheels, the accelerator opening, etc. Change control is performed, and differential limit torque release control is performed when the brake is applied.

FIG. 1 is a cross-sectional view showing a differential 1 in which a controlled rotation difference sensitive joint A is built-in. 10
A pinion 12 rotatably supported via a pinion shaft 11, a pair of side gears 13 and 14 meshing with the pinion 12, and two left drive shafts 15 and a right drive connected to the side gears 13 and 14. A shaft 16 is provided.

The drive torque is equally distributed to the left and right drive shafts 15 and 16 when no differential rotation occurs, and when differential rotation occurs, the drive torque is driven by the differential limited torque by the control type rotation difference sensitive joint A. Torque is transmitted from the high rotation side to the low rotation side.

Hereinafter, the configuration of the control type rotation difference sensitive joint A will be explained with reference to FIGS. 1 to 6.

Among the control type rotation difference sensitive joints A, the rotation difference sensitive joint 20 exhibiting a rotation difference sensitive joint function is one of the left drive shaft 15 (first rotation shaft) and the right drive shaft 16 (second rotation shaft). A cam surface 31 formed on the inner surface of a drive housing 30 spline-coupled to one left drive shaft 15, a rotor 40 spline-coupled to the other right drive shaft 16, and a differential rotation A driving piston 50 in a radial arrangement that reciprocates in the radial direction while slidingly contacting the cam surface 31, a cylinder chamber 60 whose volume changes as the driving piston 50 reciprocates, and the cylinder chamber 6.
0 through a balance oil passage 71.
0, one end of the spool chamber 70 is opened, an accumulator chamber 90 is communicated with the cylinder chamber 60 via the regulator oil passage 80, and an accumulator chamber 90 is formed at the opening end of the balance oil passage 71 with respect to the spool chamber 70. Orifice 1
00.

In addition, 32 is a drive housing cover, 41 is a cylinder hole, 42 is a relief valve hole, 51 is a seal ring, 8
1 is a ball one-way valve, 91 is an accumulator piston, 92 is a spring retainer, and 93 is a return spring.

Orifice opening area changing means 1 of the orifice 100
10 is a spool 120. Center hole 130, cross hole 1
40. Butsch rod 150. Cross rod 160. It includes a slide mechanism 170 and a stepping motor 180.

The spool 120 has a spool chamber 70 formed at the axial center position of the rotor 40, as shown in FIGS. 3 and 4.
The annular groove 121 is slidably housed in the spool, and an annular groove 121 that can communicate with the orifice 100 is formed on the outer periphery. The orifice 100 is opened and closed by a first spool land 123 on the side of the accumulator chamber formed by 121, and a seal groove 125 is formed on the other side of the second spool land 124, consisting of a slipper seal 126 and an O-ring 127. A sealing member is provided, and a spool stopper plate 128 is provided at the boundary between the spool chamber 70 and the accumulator chamber 90.
is fixed.

The orifice 100 is fully opened when the spool 120 is displaced farthest from the accumulator chamber 90, and the orifice 100 is fully opened when the spool 120 is displaced most toward the accumulator chamber 90 (FIGS. 3 and 4).

The center hole 130 communicates with the spool chamber 70,
It is formed at the axis of the rotating shaft 15.

The cross hole 140 is formed to penetrate from the end of the center hole 130 in the radial direction of the left drive shaft 15.
The width of the spool 120 is set to be equal to the required stroke amount of the spool 120 and the distance between the paths.

The bushing rod 150 has one end connected to the spool 12.
0 and is inserted into the center hole 130 so as to be slidable in the axial direction.

The cross rod 160 is connected to the bush rod 150.
It is fixed to the other end, and both ends are connected to the rotating shaft 1 through the cross hole 140.
5 and is provided so as to protrude slightly from the outside.

The slide mechanism 170 includes an inner sleeve 171 connected to the cross rod 160 and provided on the outer periphery of the left drive shaft 15 so as to be slidable in the left-right direction in the figure;
An outer sleeve 173 is provided on the outer periphery of the outer sleeve 1 with a pole bearing 172 interposed therebetween to allow relative rotation.

As shown in FIG. 3, the stepping motor 180 is attached to the differential housing 5 and is connected to a fork shaft 181 connected to the motor shaft 184.
A letter-shaped fork 182 is attached, and this fork 1
The cam surface 183a of the cam portion 183 of 82 is disposed in contact with the cam follower surface 173a of the outer sleeve 173.

Then, as shown in FIGS. 5 and 6, the fork shaft 1
A pinion 185 is fixed to the end of 81, and this pinion 185 meshes with a rack 186. This rack 186 is biased by a spring 187 to force the spool 120 to the fully open position against the accumulator chamber pressure.

Note that 188 is a spring retainer.

Next, the effect will be explained.

(a) Differential limiting control effect Left and right drive shafts 15.16 when driving on rough roads or when one wheel is stuck, etc.
When a difference in rotational speed occurs between the left and right rear wheels RW and RW connected to the RW, relative rotation also occurs between the drive housing 30 and the rotor 40, and due to this relative rotation, the driving piston 50 in sliding contact with the cam surface 31 changes in diameter. reciprocating in the direction,
When the volume of the cylinder chamber 60 is reduced by moving toward the center of the rotation axis during this reciprocating motion, the pressure inside the cylinder chamber 60 increases due to the flow resistance caused by the outflow restriction by the spool 120, and this generated oil pressure and the pressure receiving area of the piston 50 The combined hydraulic pressure becomes a force that presses the driving piston 50 against the cam surface 31, and this pressing force acts as a differential limiting torque, and in the distribution of driving torque, the high speed rotation side is reduced from the equal torque distribution. Therefore, the differential is limited to increase the low speed rotation side.

The differential limiting torque characteristic of the device of this embodiment can be arbitrarily changed by changing the opening area of the orifice 100.

That is, by giving a predetermined motor rotation angle θ to the stepping motor 180, the axial position of the spool 120 is determined, and the orifice opening area is changed from fully open (θ=0°) to fully closed (
θ=&JAX), thereby setting the differential limiting torque characteristic with respect to the relative rotation difference to the optimum characteristic corresponding to the running condition, as shown in the differential limiting torque characteristic in FIG.

(b) Hydraulic action at the orifice part Figure 3 shows the belt-shaped groove 121 of the spool 120 and the orifice 1.
00 and the like, indicating the orifice fully open, but when driving on a low μ road, etc., a command to stroke the spool 120 to the left in the drawing is output, and as shown in Fig. 9, the orifice opening area becomes small. When the area becomes large, the regulation of oil outflow through the orifice 100 is increased, and the oil pressure in the cylinder chamber 60 and the balance oil passage 71 becomes high pressure.

However, since the orifice 100 is opened and closed by the first spool land 123 of the accumulator chamber 90 formed by the annular groove 121, the pressure in the balance oil passage 71 communicating with the orifice 100 is limited to the first spool land 123. It acts on

Then, the first subur land 12 is placed on both sides of the annular groove 121.
The same oil pressure acts on the seal groove 125 provided on the second spool land 124 side opposite to the annular groove 121 into which the oil whose pressure has dropped through the orifice opening flows. On the other hand, this annular groove 121 communicates with the accumulator chamber 90 via a communication oil passage 122 inside the spool.

That is, as a result, only the same low accumulator pressure as the accumulator chamber 90 acts on the slipper seal 126 and the O-ring 127 provided in the seal groove 125.

(c) Orifice opening area changing effect The orifice opening area can be changed using the stepping motor 18.
This is done by converting the rotation at 0 to the stroke of the spool 120, and by applying torsional torque to the fork shaft 181 by the spring 187, rack 186, and pinion 185, the spool 120 is adjusted to the accumulator chamber pressure via the fork 182, etc. Overcome stopper plate 12
8 to keep the orifice opening area fully open.

Therefore, the force required for the stepping motor 180 is assisted by the spring 187 that overcomes the accumulator chamber pressure when moving the spool 120 in the direction of increasing the orifice opening area (toward the right in the drawing), while the force required for the stepping motor 180 is assisted in the direction of closing the orifice opening area (toward the left in the drawing). ), the force required by the spring 187 to overcome the accumulator chamber pressure is required.

As explained above, the controlled rotation difference sensitive joint A of the embodiment has the following features.

■ The orifice opening area is changed in the first spool land 123 on the accumulator chamber side, which is formed by the annular groove 121 provided in the spool 120, and the seal groove 125 and seal member are provided in the other second spool land 124. , only the maximum accumulator chamber pressure acts on the seal portion of the spool 120, and it is possible to reduce leakage from the seal portion of the spool 120, improve the durability and reliability of the seal member, and reduce the sliding resistance of the spool 120. .

■ A spring 187 is provided in a part of the orifice opening area changing means 110 that controls the axial displacement of the spool 120, so that the orifice opening area can be kept fully open by overcoming the accumulator chamber pressure even when there is no force from the stepping motor 180. Since a preload is applied to the spool 120, in the event of a failure such as a wire breakage, it becomes a normal differential device and safety can be ensured.

(2) If the biasing force of the spring 187 is set to a value slightly larger than the accumulator chamber pressure, the characteristics change slowly in the event of a failure, and sudden changes in the behavior of the vehicle can be prevented.

In addition, a stepping motor 180 which is an actuator
The required torque due to this can be the difference between the biasing force of the spring 187 and the accumulator chamber pressure, so the size of the actuator can be reduced.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and even if there are design changes within the scope of the gist of the present invention, they are included in the present invention. It will be done.

For example, in the embodiment, an example was shown in which the controlled rotation difference sensitive joint of the present invention is applied to a differential limiting device for left and right axles, but it is also applicable to a drive force distribution device of a four-wheel drive vehicle, a differential for left and right axles, and a differential for front and rear wheels. It may be used as a device or a differential limiting device for front and rear wheels.

Further, in the embodiment, an example is shown in which a stepping motor is used as the actuator, but other actuators such as a DC motor may be used.

Further, the orifice 100 is not limited to a rectangular shape, and may have any shape such as a circle, a triangle, or an ellipse.

Furthermore, in the embodiment, an example was shown in which the driving of the stepping motor 180 is automatically controlled by the controller 200;
The drive may be controlled manually by the driver's switch operation, or may be controlled either automatically or manually.

(Effects of the Invention) As described above, the present invention provides an accumulator chamber formed by an annular groove provided in a spool in a controlled rotation differential sensitive joint in which the opening area of an orifice can be changed by an external actuator. The orifice opening area is changed on the spool land on the side, and a sealing member is provided on the spool land on the opposite side, which reduces leakage from the spool seal, improves the durability and reliability of the sealing member, and reduces spool sliding. This provides the effect of reducing dynamic resistance.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional plan view showing a differential to which a control type rotation difference sensitive joint according to an embodiment of the present invention is applied, FIG. 2 is a longitudinal sectional front view of the rotation difference sensitive joint taken along line I-I in FIG. The figure is an enlarged sectional view showing the orifice opening area changing part of the embodiment joint, FIG. The figure is a sectional view taken along the line ■-■ in Figure 5, Figure 7 is a schematic diagram showing the engine drive system and control system to which the embodiment joint is applied, and Figure 8 is a differential limiting torque characteristic diagram by the embodiment joint. FIG. 9 is an explanatory diagram of the hydraulic action at the orifice portion in the embodiment, and FIG. 10 is an explanatory diagram of the hydraulic action at the orifice portion in the prior art. A... Control type rotation difference sensitive joint 15... Left drive shaft (first rotation shaft) 16... Right drive shaft (second rotation shaft) 20... Rotation difference sensitive joint 70... Spool chamber 00... Orifice 10... Orifice opening area changing means 20... Spool 21... Annular groove 22... Communication oil passage (oil passage) 23... First spool land 24... Second spool land 25...Seal groove 26...Slipper seal (seal member) 27...
0-ring (sealing member) 180...Stepping motor (actuator) Fig. 2

Claims (1)

[Claims] A first rotating shaft and a second rotating shaft that are coaxially arranged so as to be relatively rotatable, and a flow rate discharged according to a relative rotational speed difference between the first and second rotating shafts. a rotation difference sensitive joint that converts the fluid pressure into fluid pressure through outflow regulation by an orifice, and further converts this fluid pressure into a transmission torque between the two shafts, and a rotation difference sensitive joint disposed at the orifice position,
An annular groove that can communicate with the orifice is formed on the outer periphery, and the annular groove communicates with the accumulator chamber through an oil path inside the spool, and the orifice is opened and closed by the first spool land on the accumulator chamber side formed by the annular groove. A control type comprising: a spool provided with a sealing member on the second spool land side opposite to the accumulator chamber; and orifice opening area changing means for stroking the spool by an external actuator. Rotation difference sensitive joint.