JPH0211902A - Three-position rotary actuator - Google Patents

Abstract

PURPOSE:To simplify motion signals and increase the strength by pinching a swinging body of a rotary actuator by a pair of centering pistons in the middle of swinging. CONSTITUTION:A swing shaft 17 is furnished in the central part of a cylinder 15 of a rotary actuator 11, and pistons 19a, 19b are installed at the ends of a rack 18 to mesh with a pinion 16 of this swing shaft 17. Centering pistons 26a, 26b are put in contact with these pistons 19a, 19b with push rods 26a, 26b interposed. Thereby the rotary actuator can be stopped in three positions by a direction selector valve 13, so that the motion signal is simplified and the strength enlarged.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a three-position rotary actuator used in industrial machinery that uses fluid pressure. This invention relates to a 3-position rotary 7-cut unit suitable for.

[Prior Art] As shown in Fig. 6, a workpiece 2 is conveyed by a conveyor
．． When distributing the workpieces to the left and right conveyors 3 and 4, the device can be simplified by driving the gripper 5 that distributes the workpieces using the three-position rotary actuator 8.

For this purpose, a rotary unit that can be stopped at three positions has been proposed in Japanese Patent Laid-Open No. 83-43008.

However, in the previously proposed rotary unit, since the main piston for swinging the swing shaft and the intermediate piston for stopping the main piston at an intermediate position each take two positions, the positions are substantially equal to four, Therefore, two electromagnetic valves are required to drive these pistons, which complicates the signal.Furthermore, since the two pistons are connected by a small diameter pin, there is a problem that the strength is low.

[Problems to be Solved by the Invention] An object of the present invention is to clamp the oscillating body of the rotary actuator section at an intermediate oscillating position between a pair of centering pistons, thereby providing a simple and strong operating signal. An object of the present invention is to provide a position rotary actuator.

[Means for Solving the Problems] In order to achieve the above object, a three-position rotary actuator of the present invention includes a rotary actuator section that rotates and oscillates with pressure fluid supplied to and discharged from a pressure chamber.

A pair of centering parts for stopping the rotary actuator part at an intermediate swing position, and a directional switching valve for supplying and discharging pressure fluid to and from the rotary actuator part and the pair of centering parts, the pair of centering parts The directional control valve includes a centering pressure chamber and a centering piston that clamps the oscillating body of the rotary actuator section in the pressure chamber, and the directional switching valve has an intermediate switching position where the fluid pressures in the pressure chamber and the centering pressure chamber are equal. It is characterized by

Further, in order to achieve the same objective, it is preferable that the directional control valve is of a pressure center type.

Furthermore, in order to simplify the supply and discharge of pressure fluid, it is preferable to provide a passage that communicates the pressure chamber with the centering pressure chamber.

[Operation] When the directional switching valve is in the intermediate switching position, the swinging body of the rotary actuator is held between a pair of centering pistons and stopped at the swinging middle position.

When switching the directional valve from the intermediate switching position to any other position,
When the pressure fluid in one pressure chamber and the centering pressure chamber is supplied and discharged, the rotary actuator section rotates and swings in either the left or right direction from the intermediate stop position, and the directional switching valve is switched to the intermediate switching position.

It stops again at the mid-swing position.

Therefore, the rotary actuator can be stopped at three positions by the directional switching valve, the operation signal is simple, and there is no need to worry about strength.

Furthermore, when the directional switching valve is of a pressure center type, fluid pressure acts on the pair of centering pistons that sandwich the m moving body at the intermediate switching position, so that the rotary actuator can be reliably stopped at the intermediate swinging position.

Furthermore, if a passage is provided that communicates the pressure chamber of the rotary actuator section with the centering pressure chamber, supply and discharge of pressure fluid becomes easy.

[Embodiment] FIG. 1 shows a first embodiment of the present invention, and this three-position rotary actuator includes a rotary actuator section 11,
It is provided with a pair of centering parts 12A and 12B at both ends thereof, and a directional switching valve 13 for supplying and discharging pressure fluid to these parts.

The cylinder 15 of the rotary actuator section 11 shown schematically includes a swing shaft 17 at the center thereof.
Pistons 193 and 19b provided at both ends of the rack 18 that mesh with the pinion 18 of
It is divided into b.

Cylinders 233, 23 of centering parts 12A, 12B
b is installed on both sides of the cylinder 15 via a partition wall, and the centering pressure chamber 25 is controlled by centering pistons 243 and 24b that slide inside the cylinders 233 and 23b.
3, 25b are partitioned, and a centering piston 24a.

The bushing rods 263 and 28b screwed onto 24b are
The tips of the pistons 203 and 20b, which extend through the partition wall in an airtight manner, are brought into contact with the pistons lea and 19b by the biasing force of the centering springs 273 and 27b.

In this case, the bushing rod 26a is shown in FIG.

Although the protrusion length of 28b into the pressure chambers 203 and 20b is equal to L, one may be longer than the other.

Further, the cylinders 15, 233, 23b have ports 283, 28b, 28c, 2 for supplying and discharging pressure fluid to the pressure chambers 203, 20b and the centering pressure chambers 253, 25b.
8d has been established.

The directional control valve 13 has port 2 in the intermediate switching position.
Pressure fluid is supplied to solenoid 8a to 28d, and one solenoid 1
The solenoid 3a is energized to communicate the ports 28b and 28d to the outside, and the energization of the other solenoid 13b causes the ports 28a and 28c to be communicated to the outside.

Next, the operation of the first embodiment will be described.

FIG. 1 shows a state in which the directional control valve 13 is in the intermediate switching position and pressure fluid is supplied to the pressure chambers 203, 20b and 253, 25b, and the acting force of the fluid pressure in the pressure chambers 203, 20b is equal. Therefore, the rack 18 is connected to the center link part +2A by the bushing rods 283 and 28b.
The centering portion 12B is held at an intermediate swing position where the sum of the fluid pressure acting force of the centering pressure chamber 25a and the biasing force of the centering spring 27a is equal to the sum of the same force in the centering portion 12B.

In this state, when the solenoid 13a is excited, the fluid in the pressure chambers 20b and 25b is discharged to the outside, so the rack 18 moves to the left by a stroke L in the figure due to the fluid pressure in the pressure chamber 2Qa, and the swing shaft 17 rotates. Solenoid 13
When the solenoid is energized, the fluid pressure in the pressure chamber 20b moves the stroke to the right as shown in the figure, and the swing shaft 17 rotates in the opposite direction. and stops at the mid-swing position.

Therefore, the solenoid in the 3-position directional valve 13! By energizing and de-energizing 3a and 13b, the swing shaft 17 can be rotated left and right about the middle swing position.

FIG. 2 shows a second embodiment of the present invention, and this three-position rotary actuator includes a rotary seven-actuator section (not shown) having the same configuration as the rotary actuator section of the first embodiment, and a pair of centering sections. 30.30
(only one is shown), and the cylinder tube 31 of the rotary actuator section, the cylinder 32 of the centering section 30, the intermediate plate 33 between both cylinders, and the end cover 34 are integrally assembled by appropriate means.

The centering piston 35 sliding inside the cylinder 32 is moved from the intermediate plate 3 by a centering spring 37 compressed in the centering pressure chamber 3B on the end cover side.
A bushing rod 38, which is biased toward the centering piston 35 and screwed onto the centering piston 35, passes through the intermediate plate 33 in an airtight manner and extends into a pressure chamber 39 of the rotary actuator section. The pressure chambers 3B and 39 are connected to the bush rod 3
The pressure chambers 3B and 3 communicate with each other through a passage 38a formed in the axial direction of the pressure chambers 3B and 3 through a port 40 opened in the end cover 34.
9 can be supplied with and discharged from pressure fluid. The other centering portions in the second embodiment have a mirror image relationship with the centering portion 30 described above.

The other configurations and operations of the second embodiment are the same as those of the first embodiment, so detailed explanations will be omitted.

FIGS. 3 and 4 show a third embodiment of the present invention, and this three-position rotary actuator includes a rotary actuator section 43 made of a vane-type rotary actuator and centering sections 44A and 44B.

The bodies 45 of the centering parts 44A, 44B are provided with centering pressure chambers 483, 48b in which the centering pistons 473, 47b slide, and a recess 45a around the swing shaft 43a of the vane type rotary actuator, and these are provided with covers 483, 48b. , 48c.

The centering pistons 473, 47b have recesses 45
a slidable bushing rod 49a extending into a.

49b, centering springs 503, 5(l
The centering pressure chambers 463, 48b and the pressure chambers (not shown) of the rotary actuator section 43 communicate with each other through passages 523, 52b formed in the body 45. . In addition, the stopper block 5 screwed to the swing shaft 43a
4 includes a radial stopper 55 fixed by adhesive, brazing, or the like.

In the third embodiment, the centering pressure chambers 463, 4
When pressure fluid is supplied to the pressure chambers of the centering pressure chambers 4e3 and 4ftb and the vane-type actuator, the bu and shrods 493 and 49b sandwich the stopper 55 to stop the swing shaft 43a at the middle swing position, and the centering pressure chambers 4e3 and 4ftb and the pressure chambers When either one of the pressure fluids is discharged, the centering piston on the discharge side slides due to the biasing force of the centering spring, releases the grip of the stopper 55, and moves the pivot shaft 43.
a rotates in that direction.

FIG. 5 shows a fourth embodiment of the present invention, and this three-position rotary actuator includes a rotary actuator portion B1 and centering portions 82A and 82B.

The rotary actuator section 61 includes pistons 653 and 8 that slide inside a cylinder installed parallel to the body 84.
5b, and a rocking shaft 6B having a pinion that meshes with a rack formed on these pistons, and includes a piston 653,
Pressure chambers 87a, 88b and 8 divided by 85b
8a and 67b communicate with each other through a passage (not shown).

The centering parts 82A and 82B are centering pistons 703 and 703 that slide within a cylinder formed on the axis of the cylinder of the rotary actuator part 61, respectively. Oh, and the centering pressure chamber? bushing rods 733, 7 integral with centering pistons 703, 70b;
3b extends to pressure chambers 873 and 88a, and pressure chamber 7! a.

71b and the pressure chambers 673, 88a communicate by axial passages 743, 74b formed in the piston and bushing rod.

Are the symbols 783 and 76b in Fig. 5 centering pressure chambers?
Boat supplying and discharging pressure fluid to 13, 71b, 773, ?
7b is a stopper for the pistons 653 and 85b.

The other structure and operation of the fourth embodiment is that the pair of pistons 853 and 85b slide due to the supply and discharge of pressure fluid.
Since this is the same as the embodiment, detailed explanation will be omitted.

[Effects of the Invention] The three-position rotary actuator of the present invention stops the rotary actuator at an intermediate swinging position when the directional switching valve is switched to the intermediate switching position, and rotates and swings left and right when the directional switching valve is switched to another position. The operation signal of the directional control valve is extremely simple and the operability is good because the rotary actuator's oscillating body is held between a pair of centering pistons and stopped at an intermediate oscillating position.

Since the operation is reliable and the strength is high, the life of the actuator can be extended.

Further, since the three-position directional switching valve is of the center pressure type, the rotary actuator can be reliably stopped at the mid-swing position by the acting force of the pressure fluid supplied to the centering pressure chamber.

Furthermore, since the pressure chamber of the rotary actuator section and the centering pressure chamber are communicated with each other through the passage, supply and discharge of pressure fluid is easy.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of the first embodiment of the present invention, and FIG.
FIG. 3 is a vertical cross-sectional view showing the main parts of the third embodiment, FIG. 4 is a cross-sectional view taken along line A-A in FIG. 3, and FIG. 5 is the fourth embodiment. FIG. 6 is a plan view showing an example of the mode of use of the present invention. II, 43, 81φ・Rotary actuator part, 12
A, 12B, 30.44A, 44B, 82A
, 82B...centering section. 253, 25b, 3G, 483, 4[ib,? 13, 7
1b... Senkling pressure chamber, 383, 523, 52b, 743, 74b ・0 passage. NISMC Co., Ltd. 13... Directional switching valves 203, 20b, 39,873, 67b, 883, 88
bφ・Pressure chamber, 243, 24b, 35.473, 47b
, 703, 70bφ centering piston. Diagram

Claims (1)

[Scope of Claims] 1. A rotary actuator section that rotates and oscillates by pressure fluid supplied to and discharged from a pressure chamber, a pair of centering sections for stopping the rotary actuator section at an intermediate position of oscillation, and the rotary actuator section. and a directional switching valve for supplying and discharging pressure fluid to and from the pair of centering parts, the pair of centering parts having a centering pressure chamber,
The directional control valve includes a centering piston that clamps the oscillating body of the rotary actuator section in the pressure chamber, and the directional control valve has an intermediate switching position where fluid pressures in the pressure chamber and the centering pressure chamber are equal. 3 position rotary actuator. 2. The three-position rotary actuator according to claim 1, wherein the directional switching valve is of a pressure center type. 3. The three-position rotary actuator according to claim 1 or 2, further comprising a passage that communicates the centering pressure chamber with the pressure chamber.