JPS6319728B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotary drive device using fluid pressure as a drive source, particularly suitable for use as a drive source for industrial robots.

A reciprocating rotary drive that has the same function as human joints is essential for robots. Mechanisms that use fluid pressure to perform such rotational drive include swinging vane motors and mechanisms that combine a rack and pinion. And it was difficult to obtain accurately. In other words, in the conventional technology in which a pinion and a rack are used to operate the reciprocating motion of the rack using a pressure fluid as a driving source, and the pinion is rotated and oscillated via the rack, a rotational oscillation angle of two or more predetermined positions is obtained. There are methods of stopping the rack or pinion at an intermediate position other than the stroke end and methods of changing the stroke end position, but the method of stopping at an intermediate position has the disadvantage that the mechanism is complicated and the stopping position is not accurate. Furthermore, it is difficult to obtain inertia in order to stop a moving object.

The purpose of the present invention is to provide a rotary drive device using a rack and pinion in which the rotation angle (oscillation angle) can be changed within a predetermined range, and the inertia caused by rotation can be eliminated to enable smooth rotational drive. .

The first invention of the present application is a rotation system in which a rack is provided on a drive piston movably provided in a main cylinder hole, and the drive piston moves the rack in a linear reciprocating motion to rotate a pinion meshed with the rack. In the drive device, at least one of the supply and discharge ports communicating with the main cylinder hole is provided to extend in the axial direction at a position approximately on the axis of the cylinder, and the supply and discharge port of the cylinder is located approximately on the axis of the cylinder. An annular control cylinder hole surrounding the supply/discharge port and communicating with the cylinder hole is provided on the side formed in the supply/discharge port, a control piston is movably provided in the control cylinder hole, and the piston rod of the control piston is connected to the supply/discharge port. The cylinder is formed into an annular shape surrounding the port so that its tip can protrude into the main cylinder hole, and the cylinder is provided with a throttle passage that communicates at least the supply/discharge port on the side where the control cylinder is located with the main cylinder hole. The valve body is configured to be movable relative to the drive piston and engage with the end of the piston rod to prevent communication between the main cylinder hole and the supply/discharge port.

The second invention of the present application is a rotation system in which a rack is provided on a drive piston movably provided in a main cylinder hole, and the drive piston moves the rack in a linear reciprocating motion to rotate a pinion meshed with the rack. In the drive device, at least one of the supply and discharge ports communicating with the main cylinder hole is provided to extend in the axial direction at a position approximately on the axis of the cylinder, and the supply and discharge port of the cylinder is located approximately on the axis of the cylinder. An annular control cylinder hole surrounding the supply/discharge port and communicating with the cylinder hole is provided on the side formed in the supply/discharge port, a control piston is movably provided in the control cylinder hole, and the piston rod of the control piston is connected to the supply/discharge port. The cylinder is formed into an annular shape surrounding the port so that its tip can protrude into the main cylinder hole, and the cylinder is provided with a throttle passage that communicates at least the supply/discharge port on the side where the control cylinder is located with the main cylinder hole. is provided with a valve body movable relative to the drive piston that engages with an end of the piston rod to prevent communication between the main cylinder hole and the supply/discharge port, and the cylinder has a control cylinder hole. Another control cylinder hole is provided adjacent to the another control cylinder hole, and another control piston that presses the adjacent control piston is movably provided in the another control cylinder hole, and the stroke of the control piston is moved by the other control piston. It is configured to be larger than the stroke of.

Embodiments of the present invention will be described below with reference to the drawings.

In the figure, an embodiment of a rotary drive device according to the invention is shown. Rotary drive device 1 of this embodiment
is constructed by integrally incorporating a plurality of control cylinders 3, 4, 3a, 4a on both sides of a drive cylinder 2 and a pinion 5 rotated by the drive cylinder into the main body. Note that the control cylinders 3 and 4 and the control cylinders 3a and 4a, respectively, have the same structure and function, except for the arrangement positions, so one of them, 3 and 4, will be explained.

The drive cylinder 2 has a main cylinder hole 21 formed approximately in the center of the main body 10, and a cylindrical drive piston 22 movably disposed within the cylinder hole 21. The drive piston 22 has a rack 23
is formed, and a pinion 5 rotatably supported by the main body is engaged with the rack 23. An axial through hole 24 is formed in the drive piston 22,
A rod 26, which is longer than the drive piston, is inserted into the through hole 24 so as to be movable relative to the drive piston. At both ends of the rod 26 are valve bodies 27, 2 that engage with the ends of the piston rod of the control piston to close the supply/discharge port to the main cylinder hole.
7a is fixed.

The first control cylinder 3 has a control cylinder hole 31 formed in the main body 10 near one end of the main cylinder hole (the right end in the figure) and communicating with the main cylinder hole through an annular hole 32, and a control cylinder hole 31 inside the control cylinder hole 31. It has an annular first control piston 33 which is movably disposed in the control piston 33 . A tubular piston rod 34 fixed to the control piston 33 extends through the annular hole 32 so that the end surface of the piston rod 34 is substantially flush with the right end surface of the main cylinder hole 21 when the control piston 33 is at the right end position as shown. It's getting old.

The second control cylinder 4 has a second control cylinder hole 41 formed in the main body 10 adjacent to one end (right end in the figure) of the main cylinder hole and communicating with the first control cylinder hole through an annular hole 42. , an annular second control piston 43 movably disposed in the auxiliary cylinder bore 41. Tubular piston rod 44 fixed to control piston 43
When the extension control piston 43 is at the right end position as shown in the figure, the piston rod 4 is inserted through the annular hole 42.
The end face of the cylinder 4 is substantially flush with the right end face of the first control cylinder hole 31.

The main body 10 has a pair of supply/discharge ports 1 that open at both ends of the main cylinder hole inside the annular piston.
1, 11a and its supply/discharge ports 11 and 11a
and the main cylinder hole respectively through variable apertures 6 and 6a.
A pair of throttle passages 12 and 12 communicating through
a is formed. Supply/discharge ports 11 and 11a
is connected to a fluid pressure source via one switching valve 7,
By alternately switching the switching valve, fluid pressure is alternately supplied and discharged, thereby causing the drive piston 23 to reciprocate.

The body 10 further includes first and second control ports 15, 15 communicating with the first and second control cylinder holes.
a and 16, 16a are formed, which are respectively connected to separate control valves 8, 8a and 9, 9a, respectively.

Next, the operation of the rotary drive device of this embodiment will be explained.

If you want to operate the drive piston at its maximum stroke and maximize the rotation angle, control valves 8 and 8
Only the switching valve 7 is operated without operating any of the valves a, 9, and 9a. In this way, the supply/discharge port 1 is connected to the chambers A and B on both sides of the drive piston 23.
1 and 11a, the driving piston reciprocates, and the pinion also reciprocates at the maximum angle. Near the end of the movement of the drive piston, a valve body 62 or 62a (protruding in the traveling direction due to the folding of the drive piston) is attached to the drive piston and is located on the exhaust side.
comes into contact with the end wall of the main cylinder hole and the supply/discharge port 11
or 11a, so that the subsequently discharged fluid is discharged only through the throttle passage 12 or 12a, and the drive piston is braked and its inertia is reduced when it stops rotating.

Next, when you want to reduce the rotation angle of the pinion by one step, the control valve 9 or 9a for the second control cylinder
is operated to supply fluid pressure to chamber E or F, and
and second control cylinders 3 and 4 or 3a and 4
The control piston a is moved toward the drive piston by the stroke of the second control piston.

For example, if the control valve 9a is now operated to supply fluid pressure to the chamber F of the second control cylinder 4a, the first
The control pistons of the second control cylinders 3a, 4a move toward the drive cylinder by the stroke of the second control piston, and the piston rod of the first control cylinder 3a protrudes into the main cylinder chamber by that amount. Limit movement. Therefore, the stroke of the drive piston 22 is
(one control piston), and the rotation angle of the pinion also becomes proportionally smaller.

Even in this case, when the drive piston moves leftward and the valve body 27a protruding toward the chamber B comes into contact with the tip of the piston rod, the valve body 27a is connected to the chamber B and the supply/discharge port 1.
Since the communication with 1a is cut off and the fluid in chamber B is discharged only through the throttle passage 12a, braking is applied to the drive piston, and the inertial force is reduced until it stops.

Thereafter, as necessary, in the same manner as described above, both of the second control cylinders 4 and 4a, one of the second control cylinders (for example 4) and the other of the first control cylinders (for example 3a), or the second control cylinder Both control cylinders of one can be selectively operated to limit the stroke of the drive piston and change the angle of rotation of the pinion.

It should be noted that it is possible to install two or more control cylinders in series on one side of the drive cylinder, in which case their strokes must increase in the order of proximity to the drive cylinder, but The strokes of the left and right control pistons do not necessarily have to be the same, and can be selected as desired.

Furthermore, since the movement of the drive piston is regulated by the control piston, if fluids of the same pressure are used, the pressure receiving area of the control piston must be larger than that of the drive piston.

Furthermore, although the above embodiment describes the case where the rotation angle is changed, it is possible to make the pressure receiving area (or working fluid pressure) of the control piston very small compared to that of the drive piston so that the control piston can be pushed back by the drive piston. For example, the braking start position of the drive piston can be selectively changed while keeping the stroke of the drive piston constant.

As described above, in the rotary drive mechanism of the present invention, since the rotational drive mechanism of the present invention is reliably stopped by the mechanical stopping means, the rotation angle can be reliably controlled, and at the same time, the inertia can be reduced by applying braking at the time of stopping.

[Brief explanation of the drawing]

The figure is a sectional view of an embodiment of a rotational drive device according to the present invention. 1: Rotary drive device, 2: Drive cylinder, 23:
Drive piston, 3, 4, 3a, 4a: control piston, 33, 43: control piston, 34, 44: piston rod, 5: pinion, 62: valve body.

Claims (1)

[Scope of Claims] 1. A rotary drive device in which a rack is provided on a drive piston movably provided in a main cylinder hole, and the drive piston moves the rack in a linear reciprocating motion to rotate a pinion meshed with the rack. , at least one of the supply and discharge ports communicating with the main cylinder hole is provided to extend in the axial direction at approximately the axial center of the cylinder, and the supply and discharge port of the cylinder is formed approximately at the axial center. An annular control cylinder hole surrounding the supply/discharge port and communicating with the cylinder hole is provided on the side where the supply/discharge port is provided, a control piston is movably provided in the control cylinder hole, and the piston rod of the control piston is connected to the supply/discharge port. A surrounding annular shape is formed so that the tip can protrude into the main cylinder hole,
The cylinder is provided with a throttle passage that communicates at least the supply/discharge port on the side where the control cylinder is located with the main cylinder hole, and the drive piston is provided with a throttle passage that communicates with the main cylinder hole by engaging with an end of the piston rod. A rotary drive device characterized in that a valve body for blocking communication with the supply/discharge port is provided so as to be movable relative to the drive piston. 2. The control cylinder holes are provided on both sides of the main cylinder hole, the control piston is movably provided in each of the control cylinder holes, the throttle passage is provided on both sides of the main cylinder hole, and the valve body is provided with the drive The rotary drive device according to claim 1, characterized in that the rotary drive device is provided on both sides of the piston. 3. A rotary drive device in which a rack is provided on a drive piston that is movably provided in a main cylinder hole, and the drive piston moves the rack in a linear reciprocating manner to rotate a pinion that meshes with the rack. At least one of the supply and discharge ports communicating with the cylinder is provided extending in the axial direction at a position approximately on the axis of the cylinder, and a side of the cylinder where the supply and discharge port is formed approximately on the axis is provided with a supply and discharge port extending in the axial direction. An annular control cylinder hole surrounding the supply/discharge port and communicating with the cylinder hole is provided, a control piston is movably provided in the control cylinder hole, and a piston rod of the control piston is formed into an annular shape surrounding the supply/discharge port with a tip end thereof. capable of protruding into the main cylinder hole;
The cylinder is provided with a throttle passage that communicates at least the supply/discharge port on the side where the control cylinder is located with the main cylinder hole, and the drive piston is provided with a throttle passage that communicates with the main cylinder hole by engaging with an end of the piston rod. A valve body for blocking communication with the supply/discharge port is provided to be movable relative to the drive piston, and the cylinder is provided with another control cylinder hole adjacent to the control cylinder hole to provide another control cylinder. A rotary drive device characterized in that another control piston that presses the adjacent control piston is movably provided in the cylinder hole, and the stroke of the control piston is made larger than the stroke of the other control piston. 4. the control cylinder hole and another control cylinder hole are provided on opposite sides of the main cylinder hole, respectively, and the control piston and another control piston are respectively movably provided in each of the control cylinder hole and the other control cylinder hole, 4. The rotary drive device according to claim 3, wherein the throttle passage is provided on both sides of the main cylinder hole, and the valve body is provided on both sides of the drive piston.