JPH03219124A - Control type rotational difference sensing coupling - Google Patents

Abstract

PURPOSE:To prevent the characteristic of transmitted torque of each unit from dispersing by providing a means for executing the initial setting of a spool reference position through regulating an attaching position in a direction of rotation of a motor to generate force for returning a motor shaft to a position of a control angle being zero even in the case of an electric source being OFF. CONSTITUTION:In the case of the initially setting of a spool reference position of a control type rotational difference sensing coupling A, which is first kept in a state where force generated by returning force generating means 90 brings a stopper into contact, and the rotation of a motor shaft is checked at a temporary reference position being zero, and a command is given to the motor to made the motor shaft rotatingly move at a relatively large control angle. In this state, a fixed relative rotary speed difference is given to the first rotating shaft 15 and the second rotating shaft 16, and motor case attaching regulating mechanism regulates an attaching position in a direction of rotation of a motor main body to generate transmitting torque corresponding to the given relative rotary speed difference, and the motor is fixed at this position. An electric source for the motor is then turned off to make the means 90 rotatingly move the motor shaft as far as a control angle in its returning direction.

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. 0156γ 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. It shows a rotation differential sensitive joint that converts the amount into fluid pressure through outflow regulation by an orifice, and further converts this fluid pressure into torque transmitted between both shafts, and a spool that is stroked in the axial direction by an externally controlled motor. The opening area of the orifice is changed depending on the relative positional relationship between the motor-driven spool and the orifice.

(Problems to be Solved by the Invention) However, in such a conventional control type differential rotation sensitive joint, the axial position of the spool is based on the position of a spool stopper provided with a rotor. That is,
The reference point is the position where the spool is pressed against the spool stopper by the hydraulic force of the accumulator chamber.

Furthermore, since the motor control angle standard is set to zero at the moment the bushing rod touches the spool,
It has problems as listed below.

■ The characteristics of the joint, which are determined by the relative positional relationship between the orifice and spool, are determined by the accumulation of the positional accuracy of the orifice, the longitudinal accuracy of the spool stopper, and the length accuracy of the spool.To obtain sufficient accuracy, the accuracy of each individual component must be It needs to be made very precisely.

■ When determining the reference position of the motor, the reference position is determined at the moment the bushing rod makes contact with the spool, so it is difficult to judge the moment of contact, and errors are bound to occur.

(2) As shown in FIG. 8, the characteristics of this type of joint are that the transmitted torque is proportional to the square of the orifice opening area. Therefore, as shown in Fig. 9, when the orifice is fully open, the transmitted torque does not change much even if the spool is slightly displaced in the axial direction; rotational displacement of the motor)
The transmitted torque also changes significantly. Therefore, if the reference position is set when the orifice is fully open as in the conventional example, the transmitted torque near the fully closed position will vary greatly depending on the unit.

■ When the power to this system is turned off (the vehicle is not in use), there is nothing actively stopping the rotation of the motor, so if the motor starts rotating for some reason, the next system When the power is turned on, the rotated position is determined to be zero, resulting in a loss of control accuracy.

The present invention has been made with attention to the above-mentioned problems, and is intended to improve the machining accuracy and assembly accuracy of parts in a controlled rotation differential sensitive joint in which the opening area of the orifice can be changed by an externally controlled motor. It is an object of the present invention to eliminate variations in the transmission torque characteristics of individual units while creating a low-cost unit that does not increase the cost, and to always ensure high control accuracy regardless of whether the system power is ON or OFF.

(Means for Solving the Problems) In order to solve the above problems, in the controlled rotation difference sensitive joint of the present invention, the initial setting of the spool reference position is performed by adjusting the mounting position in the rotational direction of the motor, and even when the power is turned off. Means for generating a force in the direction of returning the motor shaft to the zero control angle position is provided.

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 orifice opening area changing means that converts the rotational movement of a motor controlled from the outside into a stroke movement of the spool via a transmission mechanism, and changes the orifice opening area depending on the spool stroke position; A motor case having a stopper for blocking the motor shaft at a certain position and a mounting adjustment mechanism for adjusting the mounting position of the motor body in the rotational direction; and a return force generating means for generating a force in the return direction to press the motor shaft against the stopper. It is characterized by

(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. If you want to change this transmission torque characteristic, apply a predetermined drive command to the motor from the outside and drive it, and the rotational movement of the motor will be converted to the stroke movement of the spool via the transmission mechanism, thereby improving the outflow control effect. The determined orifice opening area is changed depending on the relative positional relationship between the spool and the orifice.

When initializing the spool reference position of this control type rotation difference sensitive joint, first, the stopper is brought into contact with the force of the return force generating means, and the motor shaft rotation is prevented at the temporary zero reference position, and the motor is A command is given to the motor shaft to rotate and displace it at a relatively large control angle. In this state,
A fixed relative rotational speed difference is given between the first rotational shaft and the second rotational shaft, and the rotational direction of the motor body is mounted by the motor case mounting adjustment mechanism so that the transmission torque corresponds to the given relative rotational speed difference. Adjust the position and secure the motor against the motor case at the adjusted position.

After fixing the motor in this way, turn off the motor power.
Then, the motor shaft is rotationally displaced in the return direction by the control angle by the return force generating means, and comes into contact with the stopper and stops. This state becomes the reference position when the motor control angle is zero.

By setting the above initial settings at a factory or the like when the unit is shipped, it is possible to eliminate variations in the transmission torque characteristics from unit to unit.

Furthermore, since the motor shaft is fixed to the stopper by the return force generating means when the motor is powered off, disturbances such as vibration and play in the transmission mechanism are eliminated, and high control accuracy can be maintained.

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

First, the configuration will be explained.

FIG. 6 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.

In FIG. 6, 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 binion 12 rotatably supported via a binion shaft 11, a pair of side gears 13 and 14 meshing with the binion 12, and a left drive shaft 15 and a right drive connected to the side gears 13 and 14, respectively. 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 4.

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 A driving piston 50 in a radial arrangement that reciprocates in the radial direction while slidingly contacting the cam surface 31 by rotation, a cylinder chamber 60 whose volume changes as the driving piston 50 reciprocates, and a balance oil passage in the cylinder chamber 60. One end of the spool chamber 7o communicated with the spool chamber 71 via the spool chamber γO is opened, and
It includes an accumulator chamber 90 that communicates with the cylinder chamber 60 via a regulator oil passage 80, and an orifice 100 formed at the opening end of the balance oil passage A1 to the spool chamber 70.

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 pole 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, Talos hole 1
40. Butsch rod 150. Crosslot 160. It includes a slide mechanism 170 and a stepping motor 180.

The spool 120 is arranged in a spool chamber 7 such that the opening area of the orifice 100 can be changed from fully open to fully closed.
0, and is arranged at the axial center position of the rotor 40.

As shown in the cross-sectional view of FIG. 3, this spool 120 is urged by an assist spring 121 in the direction of fully opening the orifice (to the left in the figure).

Note that one end of the assist spring 121 is fixed to a spring retainer Y4 attached to the rotor 40 with a screw Y3. Also, this spring retainer γ
4 is provided with a communication hole 75 for communicating the accumulator chamber 90 and the spool chamber 70. Further, a spool stopper 76 is provided in the spool hole 70 to prevent the spool 120 from popping out due to internal pressure.

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 a 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, and a bearing 172 interposed in the sleeve 171 to prevent relative rotation. It has a follower 173 provided to allow this.

The stepping motor 180 is attached to the differential housing 5 via a motor case 185, and as shown in FIGS. 4 and 5, the stepping motor 180 moves the motor shaft 180a to a specific position by contacting with a shaft stopper 186. It has a case stopper 18γ that prevents it from rotating.

Further, an elongated hole 188 is formed on the motor case 185 side as a mounting adjustment mechanism for adjusting the rotational direction mounting position of the main body of the stepping motor 180 with respect to the motor case 185. The stepping motor 180 is fixed at.

The force in the return direction that presses the shaft stopper 186 of the motor shaft 180a against the case stopper 187 is obtained by the accumulator pressure in the accumulator chamber 90 and the assist spring 121.

A reduction gear mechanism 182 is attached to the motor shaft 180a.
is attached to the output shaft 183 of this reduction gear mechanism 182.
A fork shaft 181 is connected to the fork shaft 181, a substantially U-shaped fork 184 is attached to the fork shaft 181, and the fork 184 is connected to the follower 173.
is placed in contact with the

Next, the effect will be explained.

(Differential limiting effect) When driving on rough roads or when one wheel is stuck, the left and right drive shafts 15.16
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.

(Differential Limit Change Control) The differential limit torque characteristic of the device of this embodiment can be arbitrarily changed by changing the opening area of the orifice 100.

That is, the fork 184 is moved by the stepping motor 180.
When the follower 17 is rotated in the direction of the arrow in FIG.
3 slides to the right in FIG. 1, and accordingly, the slide mechanism 170 moves to the right in the figure and
60, bushing rod 150, and spool 120 are stroked to the right in the figure to reduce the opening area of orifice 100.

When the stepping motor 180 is driven in the opposite direction from this state, the fork 184 rotates in the direction opposite to the arrow, and as a result, the position restriction by the fork 184 with respect to the slide mechanism 100 is eliminated, and the accumulator pressure and assist spring 121 Follower 1
The spool 120 also strokes to the left in the figure while maintaining the contact state between the fork 73 and the fork 184, and the opening area of the orifice 100 increases.

When the opening area of the orifice 100 is reduced in this way, as shown in FIG. As a result, as shown in FIG. 7, a differential limiting torque characteristic is exhibited in which the gain gradually decreases with respect to the relative rotational difference.

Therefore, for example, it is possible to improve turning performance by setting a low-gain differential limiting torque characteristic at the beginning of a turn and a high-gain differential limiting torque characteristic at the late stage of a turn, or by using a high-gain differential limiting torque characteristic when driving on a rough road or when stuck. By controlling the differential limiting torque in accordance with various driving conditions and vehicle conditions, it is possible to obtain the desired optimum driving performance, such as improving all-terrain performance.

(Initial setting of spool reference position) When initializing the spool reference position of this control type rotation difference sensitive joint, first, both stoppers 186 are
, 187 are in contact with each other, and the rotation of the motor shaft 180a is prevented at the temporary zero reference position, and a command is given to the stepping motor 180 to control the motor shaft 180a at a relatively large control angle θ. (The orifice opening area is also relatively small)
Rotate and displace.

In this state, there is a constant relative rotational speed difference N between the left and right drive shafts 15 and 16. differential limiting torque T corresponding to the given relative rotational speed difference No. kg·m, loosen the bolts 189 and adjust the mounting position of the stepping motor 180 in the rotational direction using the elongated hole 188 of the motor case 185, and fix the stepping motor 180 to the motor case 185 at the adjusted position.

After the stepping motor 180 is fixed in this way, when the power to the stepping motor 180 is turned off, the motor shaft 180a is moved to the above-mentioned control angle e due to the accumulator pressure and the biasing force of the assist spring 121. It is rotationally displaced in the lifting direction and comes into contact with both stoppers 186, 187 and stops.

This state is the state where the motor control angle θ is truly zero, and after that,
The stepping motor 180 has a control angle θ. When a command is given, if a relative rotational speed difference N0 occurs, the relative rotational speed difference N. Differential limiting torque T corresponding to .

This is the reference position from which kg・m can be obtained.

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

■ By setting the above initial spool reference position at the factory, etc. when the unit is shipped, the length accuracy of the orifice 100, the accuracy of the spool 120, and the accuracy of the spool stopper 76 can be adjusted.
Even if there is a slight error in the differential limiting torque characteristics for each unit, it is possible to eliminate variations in the differential limiting torque characteristics.

As a result, units with the same characteristics and no variations can be mass-produced.

■ When the stepping motor 180 is powered off, the motor shaft 180a is fixed by the contact between the stoppers 186 and 187 due to the accumulator pressure and the biasing force of the assist spring 121, so even if there is a disturbance such as vibration, the motor shaft 180a always remains in its initial position. In addition, it is possible to eliminate the influence of play in the link mechanism and reduction gear mechanism 182, and the control accuracy can be dramatically improved.

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 the present invention may be modified without departing from the gist of the present invention. included.

For example, in the embodiment, an example was shown in which the controlled rotation difference sensitive joint of the present invention was applied to a differential limiting device for left and right 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 motor, but other motors such as a DC motor may be used.

Further, in the embodiment, an example was shown in which accumulator pressure and spring biasing force were used together as the return force generating means, but
Exactly the same effect can be obtained by using either one of the means to generate the return force.

(Effects of the Invention) As explained above, in the controlled type rotational difference sensitive joint of the present invention, the spool The initial setting of the reference position is performed by adjusting the mounting position in the motor's rotational direction, and a means is provided to generate force in the direction of returning the motor shaft to the zero control angle position even when the power is turned off, thereby improving the machining accuracy and assembly of parts. It is possible to obtain the effects of eliminating variations in the transmission torque characteristics of individual units while providing a low-cost unit that does not increase accuracy, and ensuring high control accuracy at all times regardless of whether the system power is ON or OFF.

[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 means and orifice part of the embodiment joint, Figure 4 is a sectional view showing the stepping motor and fork part of the embodiment joint, and Figure 5 is taken along the line ■-■ in Figure 4. 6 is a schematic diagram showing the engine drive system and control system to which the embodiment coupling is applied. FIG. 7 is a differential limiting torque characteristic diagram using the embodiment coupling. FIG. 9 is a transmission torque characteristic diagram with respect to the orifice opening area in a controlled rotation difference sensitive joint. FIG. 9 is a transmission torque characteristic diagram with respect to the relative rotation difference using the orifice opening area as a parameter. 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 90...accumulator chamber (return force generating means) 100
... Orifice 110 ... Orifice opening area changing means 120 ...
Spool 121... Assist spring (return force generating means) 80... Stepping motor 80a... Motor shaft 85... Morta case 86... Shaft stopper (stopper) 87... Case stopper (stopper) 88... ...Elongated hole (installation adjustment mechanism) 89...Bolt (installation adjustment mechanism)

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. is converted into fluid pressure by regulating outflow through an orifice, and a rotation differential sensitive joint that converts this fluid pressure into transmission torque between both shafts, and a transmission mechanism that transmits the rotational movement of an externally controlled motor to the spool. orifice opening area changing means for converting into a stroke operation and changing the orifice opening area according to the spool stroke position; and a stopper for preventing rotation of the motor shaft of the motor at a specific rotational position, and a rotational direction mounting position of the motor body. A controlled rotation difference sensitive joint comprising: a motor case having a mounting adjustment mechanism for adjustment; and a return force generating means for generating a force in a return direction to press the motor shaft against a stopper.