JPH05278621A - Rotation transmitting device - Google Patents

Abstract

PURPOSE:To facilitate the mounting on a base machine with a simple structure and improve a maintenance property. CONSTITUTION:In the middle of the input and output parts of a driving shaft 1 in which a rotation input part 1a by an electric motor 27 and an output part 1b for rotationally driving a load device 4 are integrally formed on the same axial line L, a hydraulic motor 5 consisting of a variable capacity piston motor is arranged, its rotor 5a is spline-connected to the driving shaft 1, and the torque of the hydraulic motor 5 is set proportional to the inclination of a shoe plate 12 with a fixed p-port pressure. A servo valve 20 is driven by the differential output between the output of a torque detector 6 and a preset torque instruction value, and the oil pressures in first and second control cylinders 13, 14 are changed to change the inclination of the shoe plate 12, and the output of the hydraulic motor 5 is increased and decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation amount transmission device provided with a hydraulic device for assisting a rotation torque input by a rotation amount input means in industrial equipment or the like.

[0002]

2. Description of the Related Art As an example of this type of rotation transmission device, there is a power steering device for an automobile. FIG. 6 shows an example of a conventional power steering device. When the vehicle is in a straight traveling state, pressure oil supplied from the hydraulic pump 41 is short-circuited in the control valve 44 from the p port 42 through the annular groove 43. The return port 45 returns to the hydraulic pump 41.

When a handle (not shown) is turned to the right, the input shaft 46 turns to the right and a rack piston 48 having a right-hand threaded portion through a torsion bar 47 causes a ball 49 to move.
Tries to slide to the right through the sector shaft 5
The zero road resistance of the wheel prevents its sliding. Therefore, the torsion bar 47 is twisted and a relative angular displacement is generated between the input shaft 46 and the worm 51. As a result, the position of each groove between the body 44a of the control valve 44 and the spool 44b engaged with the input shaft 46 and the worm 51 is displaced, and the throats 44c and 44e of the valve groove are closed.
d and 44f are opened.

As a result, the pressure oil supplied from the hydraulic pump 41 is supplied to the left cylinder chamber 52a through the p port 42, the annular groove 43 and the throat 44f, and the rack piston 48 is made to slide to the right. The hydraulic auxiliary force is applied. At the same time, the oil in the cylinder chamber 52b on the right side is returned to the return port 45 through the opened throats 44d and 44f.
By returning to the hydraulic pump 41, the torsion bar 47 as the rotation amount input means is controlled so that the twist does not always exceed a predetermined value.

When the handle is turned to the left, the torsion bar 47 is twisted to cause relative angular displacement between the valve body 44a and the valve spool 44b, as in the case of turning to the right, and the throats 44d and 44f are closed. Throat 44
The pressure oil supplied from the hydraulic pump 41 with the c and 44e opened is supplied to the right cylinder chamber 52b through the p port 42 and the annular groove 43, and the rack piston 48 is slid to the left. And apply the hydraulic auxiliary force.

[0006]

However, in such a conventional rotation amount transmission device, after converting the rotational movement of the input shaft into the linear movement of the rack piston, the linear movement of the rack piston is converted into the linear movement of the sector shaft. Since it is designed to be converted into rotary motion, the structure is complicated and it is not easy to attach it to the mother machine, and there is a problem in maintainability. Moreover, since a high pressure sliding seal portion is required in the cylinder, the production cost will be increased.

The present invention has been made in view of the above points, and it is an object of the present invention to easily attach to a mother machine and improve maintainability with an inexpensive and simple structure.

[0008]

In order to achieve the above object, the present invention applies a rotation amount input means, a load device driven by the rotation amount input means, and a rotational torque by hydraulic pressure to the load device. Variable displacement type torque assisting means, torque detecting means for detecting the rotational torque of the rotation amount inputting means, and control means for changing the output of the torque assisting means according to the rotational torque detected by the torque detecting means. In a rotation amount transmission device including: an input unit for inputting a rotation torque by the rotation amount input means;
The present invention provides a rotation amount transmission device in which an output part for driving the load device is integrally provided on the same axis line, and the torque assisting device is arranged between the input part and the output part.

[0009]

By configuring the rotation amount transmission device according to the present invention as described above, it is possible to supplement the driving force insufficient by the rotation amount input means for driving the load device with the output torque of the torque assisting means. And since the input and output parts are integrally provided on the same axis, the bearing mechanism etc. can be shared,
The structure can be simplified and the production cost can be reduced, and it can be easily attached to the mother machine.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be specifically described below with reference to the drawings. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is an explanatory view of its operation, and FIG. 3 is a block diagram showing its control system.

In FIG. 1, the input portion 1a is located on the same axis L.
The drive shaft 1 integrally formed with the output unit 1b is rotatably supported by the common bearings 2 and 3, and the load device 4 is connected to the output unit 1b side to connect the input unit 1a and the output unit 1b. In the middle,
As the torque assisting means, a hydraulic motor 5 such as a known variable displacement piston motor is arranged. Also, the input unit 1a
A well-known torque detector 6 for detecting the rotational torque by optically or magnetically measuring the amount of strain generated on its surface is provided between the hydraulic motor 5 and the hydraulic motor 5.

The hydraulic motor 5 has a rotor 5a that is spline-coupled to the drive shaft 1. Inside the rotor 5a, a plurality of cylinders 7 are provided at equal intervals parallel to the axial direction and on the same circumference. A pressure oil source 30 (see FIG. 2) on the high pressure side via a valve plate 8 having arc-shaped grooves for oil supply and oil discharge.
The low pressure side is connected to the tank 9. These cylinders 7
Each of the pistons 10 is slidably loosely inserted in the piston 10, and a shoe 11 constituting a ball joint bearing is rotatably attached to the tip end portion of the piston 10, and the shoe 11 is attached to a point X on the axis L of the drive shaft 1. Shoe plate 12 with variable tilt angle in the center
Slidably pressed against.

Further, the hydraulic motor 5 is provided with first and second control cylinders 13 and 14 on the upper and lower sides in FIG. 1, and shoes 17 and 18 rotatably mounted on the tip ends of the respective pistons 15 and 16. Are pressed against the shoe plate 12 by springs 19 and 19 (only one is shown in FIG. 1), the control cylinder 13 is connected to the port A of the servo valve 20, and the control cylinder 14 is connected to the port B. The position of the spool 20a of the valve 20 is changed by the electromagnetic actuator 21.

The electromagnetic actuator 21 is controlled by the control device 22, and the output of the control device 22 is the difference between the preset predetermined torque command value T1 and the output T2 of the torque detector 6. Compensation is performed by the compensation element 23, the servo valve 20 is driven so that the output T2 becomes constant, the inclination angle of the shoe plate 12 is controlled, and the input shaft torque is maintained at a predetermined value. In FIG. 1, reference numeral 24 is a spherical bearing that presses the shoe plate 12 via the pin 26 by the urging force of the spring 25.

In the embodiment configured as described above, as shown in the operation explanatory view of FIG. 2, the electric motor 27 is used as the rotation amount input means to drive the load device 4 in rotation, and the pressure oil source 30 is used. A case where pressure oil is constantly supplied to the p port of the servo valve 20 using the accumulator 31 and the auxiliary pump 32 that supplies pressure oil to the accumulator 31 will be described. Since a current corresponding to the load torque flows through such an electric motor, the output of the current sensor 33 that converts the current value into a signal can be used as the torque detecting means. Therefore, in the operation explanatory view of FIG. 2, an inexpensive current sensor is used instead of the usual expensive strain gauge type torque detector.

Assuming that the p port pressure supplied from the accumulator 31 is P and the inclination angle of the shoe plate 12 is θ, the output torque T of the variable displacement hydraulic motor 5 is T.
= P · θ. Therefore, it can be seen that the output torque T is proportional to the inclination angle θ when the p port pressure P is kept constant. That is, the control device 22 controls the predetermined torque command value T
When the input torque (current value) becomes larger than 1, the deviation amount becomes the operation amount to the servo valve 20 through the compensation element 23.

On the other hand, the spool valve 20a of the servo valve 20 is displaced by a distance d in the axial direction according to its operation amount,
Inflow or outflow of pressure oil to the ports a and b is performed, the control cylinders 13 and 14 are displaced accordingly, and the inclination angle θ of the shoe plate 12 is changed. When the inclination angle θ increases, the rotation torque increases and the rotation speed decreases, and when the inclination angle θ decreases, the rotation torque decreases and the rotation speed increases, which is in phase with the rotation amount of the input shaft 1 and becomes the load device. By rotating 4 the input torque is always kept at a constant value.

FIG. 3 is a control block diagram of the above rotation amount transmission device. When the input portion 1a of the drive shaft 1 is rotationally driven by the rotation amount input means, the torque detector 6 (current in the above embodiment is a current). The rotational torque is detected by the torque detection means 6'comprising the sensor 33). The servo valve 20 is displaced by the compensating element 23 composed of the deviation amount between the output T2 of the torque detecting means 6'and the preset torque command value T1, and the capacity 5'of the hydraulic motor 5 is changed to respond to the input rotational torque. Generates auxiliary torque.

As a result, the rotation amount input to the input portion 1a of the drive shaft 1 and the rotation amount compensated by the auxiliary torque are added on the output portion 1b side. At this time, the rotation amount of the output unit 1b is fed back to the input unit 1a side, and the displacement of the hydraulic motor 5 changes so that the rotation amount of the input unit and the rotation amount of the output unit have the same phase.

Next, FIG. 4 shows another example in which a part of the above-mentioned control system is modified. An arbitrary function input means 34 is inserted between the torque detecting means 6'and the compensating element 23. , The input torque is made to work at an arbitrary value. Therefore, various higher-level controls can be performed by changing this arbitrary function.

FIG. 5 conceptually shows another embodiment of the present invention in which the control system shown in FIG. 4 can be effectively used. A manual handle 35 is used in place of the electric motor 27 in the previous embodiment. The configuration is the same as that of the previous embodiment except that the torque sensor 6 of the strain gauge type or the like is provided on the input portion 1a side of the drive shaft 1 instead of the current sensor 33.

If this embodiment is applied to, for example, a power steering device of an automobile and the vehicle speed is introduced into the arbitrary function input means 34 described above, a speed-sensitive type power steering device can be obtained, and steering at low speed traveling can be obtained. It is possible to reduce the force to improve the steerability and to increase the steering force during high-speed traveling to stabilize the traveling. In this case, the manual handle 34 is attached to the steering wheel,
The load devices 4 are used as steering devices, respectively. Although the axial type piston motor is used as the variable displacement type torque assisting means in the above embodiment, a radial type or other hydraulic motor may be used.

[0023]

As described above, in the rotation amount transmitting device according to the present invention, the rotary torque input portion and the output portion are integrally provided on the same axis, and the torque assisting means is provided in the middle of the input / output portion. In addition, the structure is simplified and the material can be supplied at a low cost, can be easily attached to the mother machine, and can be applied to the continuous rotary motion part. Especially, it is easy to install and remove the input side equipment and it is easy to maintain, and the output shaft that requires strength can be made thicker and the input shaft that does not need strength can be made thinner to make the device smaller and lighter. ..

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is also an explanatory diagram of its operation.

FIG. 3 is a block diagram showing the control system of the same.

FIG. 4 is a block diagram showing another example of a control system.

FIG. 5 is an explanatory view conceptually showing another embodiment of the present invention.

FIG. 6 is an explanatory diagram showing an example of a conventional rotation amount transmission device.

[Explanation of symbols]

1 Drive shaft 1a Drive shaft input part 1b Drive shaft output part 2,3 Bearing 4 Load device 5 Hydraulic motor (torque auxiliary device) 6 Torque detector 7 Cylinder 8 Valve plate 9 Tank 10 Piston 11 Shoe 12 Shoe plate 13th 1 control cylinder 14 2nd control cylinder 15,16 Piston 17,18 Shoe 19 Spring 20 Servo valve 21 Electromagnetic actuator 22 Control device 23 Compensation element 24 Spherical bearing 27 Electric motor 30 Pressure oil source 31 Accumulator 32 Auxiliary pump 33 Current sensor 34 Arbitrary Function Input Means 35 Manual Handle

Claims (1)

[Claims] 1. A rotation amount input means, a load device driven by the rotation amount input means, a variable displacement type torque assisting means for applying a rotation torque by hydraulic pressure to the load device, and the rotation amount input means. In a rotation amount transmission device including a torque detection unit that detects a rotation torque and a control unit that changes the output of the torque assisting unit according to the detected rotation torque, the rotation torque is input by the rotation amount input unit. A rotation amount transmitting device characterized in that an input section and an output section for driving the load device are integrally provided on the same axis, and the torque assisting means is arranged between the input section and the output section.