JP2000308937A - Air operating type ball plunger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air operating type ball plunger which can position and fix a positioned member surely and high accurately over a long period. SOLUTION: A ball pressing piston 6 and a ball 7 are arranged in a cylinder hole 2B of a plunger housing 2. When pressure air is supplied fro a pressure air source 11 in the outside through an air introducing path 9 into the cylinder hole, the ball pressing piston is pressed to a side of a cylinder hole opening 2C by a pressure of air, the ball is supported to a ball contact surface 6B hollowly formed in cone shape in the ball pressing piston, the ball is partly protruded from the cylinder hole opening and fitted into a positioning recessed part 3A formed in a positioned member 3, and it is fixedly positioned. Fixing of the positioned member can be released by releasing air in the cylinder hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball plunger for positioning and fixing a rotating body, and more particularly, to an air for inserting a ball into an engagement recess formed on a member to be positioned by the pressure of pressurized air. The present invention relates to an operation type ball plunger.

[0002]

2. Description of the Related Art Conventionally, a ball plunger widely used for positioning and fixing a rotating body at a predetermined angular position is disclosed in, for example, Japanese Unexamined Utility Model Publication No. 6-15951. The positioning member is positioned and fixed by being fitted into a positioning recess formed in the positioning member by pressure.

FIG. 4 shows an example of such a conventional spring-type ball plunger. A ball plunger A1 is mounted at a fixed position near the outer periphery of a rotating body A2 as a member to be positioned. It is used by being fixed to the member A3.

The ball plunger A1 is formed by screwing a male screw formed on the outer peripheral surface of the plunger housing A4 into a screw hole A5 formed in the mounting member A3, and further stopping the rotation with a lock nut A6. Attached to.

[0005] Inside the plunger housing A4, there is formed a recess A7 having an opening M on the end face on the side facing the rotating body A2, and a compression coil spring A8 and a ball A9 are formed in the recess A7. Is housed.

The ball A9 is urged by a compression coil spring A8 so that a part thereof always projects from the opening M. The periphery of the opening M is narrowed slightly to a diameter smaller than the diameter of the ball A9 to prevent the ball A9 from falling off.

On the other hand, on the outer peripheral surface of the rotating body A2, four conical positioning recesses N into which the balls A9 are fitted are formed at equal intervals in the circumferential direction, and the rotating shaft on which the rotating body A2 is fixed. Each time A10 rotates 90 °, the ball A9 biased by the compression coil spring A8 fits into the positioning recess N to position and fix the rotating body A2.

[0008]

In the conventional ball plunger configured as described above, when the ball is released from the positioning recess of the positioning member such as the rotating body, the ball resists the urging force of the compression coil spring. Since the ball is forcibly released by pushing it back, it is necessary to apply a large torque to the rotating body and the like. there were.

Also, since the spring force of the compression coil spring cannot be increased beyond a predetermined limit in order to make the ball detachable from the positioning recess, it is difficult to firmly fix the member to be positioned and the ball is accommodated. Since a slight clearance is provided between the inner peripheral surface of the concave portion of the ball plunger and the ball to smoothly move the ball, the positioning member is positioned by fitting the ball into the positioning concave portion. Even in the fixed state, there is a problem that the positioning target member slightly rattles due to the presence of the clearance, and the positioning accuracy is low.

It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide an air-operated ball plunger capable of positioning and fixing a member to be positioned reliably and with high accuracy for a long period of time. I do.

[0011]

In order to achieve the above object, an air-operated ball plunger of the present invention has a bottomed cylinder hole opened to the outside, and an external pressurized air source is provided in the cylinder hole. A plunger housing connected to an air introduction passage connected to the cylinder hole and a ball slidably fitted into the cylinder hole and having a conical concave ball contact surface facing the cylinder hole opening side. A pressurizing piston, and a ball provided so as to be in contact with the ball contacting surface of the ball pressing piston, and a part of which can freely move out of the cylinder hole to the outside of the opening; The air is used to push the ball pressing piston with the ball in the cylinder hole to the opening side, so that a part of the ball projects from the cylinder hole opening.

In the air-operated ball plunger of the present invention, the ball contact surface is formed as a bottom surface of a cylindrical concave portion formed on an end surface of the ball pressing piston facing the cylinder hole opening side, and is provided in the cylindrical concave portion. It is desirable that a part of the ball be fitted and held.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An air-operated ball plunger according to the present invention positions and fixes a member to be positioned at a fixed position, similarly to a conventionally used ball plunger having a structure in which a ball is pressed and urged by a spring force. Or a load limiting mechanism such as a torque limiter.

The positioning member includes a rotating member such as a rotary table and a member that slides linearly. The air-operated plunger of the present invention is used for positioning and fixing the rotation angle and the sliding position. Used for

[0015] The air-operated ball plunger of the present invention comprises:
The ball is placed at a fixed position with the ball facing the side surface perpendicular to the moving direction of the member to be positioned. A conical or wedge-shaped positioning recess for fitting the ball is formed on the surface of the member to be positioned facing the ball.

An air introduction passage communicating with the inside of the cylinder hole of the plunger housing is connected to a pressurized air source such as a high-pressure air tank by piping, and when pressurized air is introduced into the cylinder hole from the pressurized air source, the ball presses. The piston moves with the ball to the opening side of the cylinder hole under this pressure,
A part of the ball projects from the opening of the cylinder hole and abuts on the opposing surface of the member to be positioned.

Here, if the positioning member is moved so that the positioning recess is substantially opposed to the ball, the ball is pushed by the ball pressing piston and fitted into the positioning recess, and the positioning member is moved to this position. Positioned and fixed.

In this state, since the ball is held on the conical ball contact surface of the ball pressing piston, there is no play in the plunger housing, and the member to be positioned is positioned with high precision. Fixed. The higher the air pressure introduced into the cylinder hole, the stronger the position of the member to be positioned is fixed.

Further, by releasing the air pressure in the cylinder hole of the plunger housing, the ball pressing piston can be easily retracted. In this state, if an external force is applied to the member to be positioned, the ball is pressed into the positioning recess. , And the positioning and fixing state is released.

Such an operation is performed, for example, by interposing a three-port two-position switching valve in the middle of an air introduction passage communicating between the pressurized air source and the cylinder hole of the plunger housing, and switching the switching valve to one position. When the air of the pressurized air source flows into the cylinder hole through the air introduction path,
When the position is switched to the other position, the connection between the inside of the cylinder hole and the pressurized air source is cut off, and the air in the cylinder hole is opened to the atmosphere instead.

Further, if a pressure adjusting valve for adjusting the air pressure supplied to the air introduction passage is provided in the middle of the air pipe, the holding force for positioning and fixing the member to be positioned can be adjusted. In this case, between the ball plunger and the member to be positioned, a torque limiter or an overload prevention mechanism capable of remotely adjusting the allowable torque and the allowable load can be configured.

Further, in the air-operated ball plunger of the present invention, a structure is employed in which a part of the ball is fitted and held in a cylindrical concave portion formed in the ball pressing piston, so that a small air pressure can be obtained. The pressing force of the ball against the positioning recess of the member to be positioned can be increased, and the member to be positioned can be reliably positioned and fixed.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing a first embodiment of an air-operated ball plunger (hereinafter, simply referred to as a ball plunger) of the present invention, and FIG. 2 is an exploded view of the ball plunger.
In the ball plunger 1 of the present invention, similarly to the conventional ball plunger shown in FIG. 4 described above, the plunger housing 2 is fixed to a mounting member 4 provided at a fixed position near the outer periphery of the rotating body 3.

In this embodiment, the plunger housing 2
Has a structure in which a male screw 2A formed on the outer peripheral surface thereof is screwed into a screw hole 4A formed in the mounting member 4, and the screwing position is fixed by a lock nut 5. The structure for fixing the plunger housing 2 to the mounting member 4 may be other than this.

The plunger housing 2 has a cylindrical bottomed cylinder hole 2B formed therein. The cylinder hole 2B has an opening 2C at one axial end of the plunger housing 2 and is open to the outside.

In the cylinder hole 2B, a ball pressing piston 6 is incorporated on the back side, and a ball 7 is incorporated adjacent to the opening 2C, and part of the ball 7 protrudes and retracts from the opening 2C. It is possible.

The ball pressing piston 6 is formed so that the maximum diameter portion of the outer peripheral surface thereof has an outer diameter that allows smooth sliding in the cylinder hole 2B in the axial direction without rattling, and a part of the outer peripheral surface includes: An annular groove 6A for mounting an O-ring 8 for sealing between the cylinder hole 2B and the inner peripheral surface is formed.

A conical concave ball contact surface 6B is formed at the end of the ball pressing piston 6 facing the opening 2C side of the cylinder hole 2B.
The ball 7 comes into contact with B in a fitted state.

The periphery of the opening 2C of the cylinder hole 2B is narrowed slightly smaller than the diameter of the ball 7 to prevent the ball from dropping out of the plunger housing 2, and only a part of the ball 7 is opened. It is possible to project outside 2C.

On the other hand, the opening 2C of the plunger housing 2
A pipe connection screw hole 2E for connecting an air pipe is formed between the end face on the side opposite to the side and the bottom face 2D of the cylinder hole 2B, and an air pipe forming an air introduction passage is formed here. 9 (see FIG. 1), a connection portion (not shown) provided on the distal end side is screwed and fixed.

The air pipe 9 is connected to a pressurized air source 11 with a switching valve 10 at a position of 3 ports 2 interposed therebetween. The pressurized air source 11 is composed of an air compressor and an accumulator (not shown in detail), and can always supply a constant air pressure to the air pipe 9.

The switching valve 10 shuts off the first position shown in FIG. 1 for supplying pressurized air from the pressurized air source 11 into the cylinder hole 2B and the inflow of air from the pressurized air source 11. The switching operation can be performed to a second position for releasing the air pressure in the cylinder hole 2B to the outside.

On the other hand, conical positioning recesses 3A in which the balls 7 are fitted are formed in four places at equal intervals in the circumferential direction in the rotating body 3, and pressurized air is formed in a cylinder hole 2B as shown in FIG. When the pressurized air is supplied from the source 11, the ball pressing piston 6 is pressed toward the opening 2C by the air pressure.

Accordingly, the ball 7 is urged by the ball contact surface 6B of the ball pressing piston 6 so as to protrude from the opening 2A to the outside of the plunger housing 2, and one of the positioning recesses 3A of the rotating body 3 is moved When the ball 7 comes to a position opposing the position, the ball 7 fits into the positioning recess 3A,
The rotating body 3 is positioned and fixed in the state shown in FIG.

At this time, the positioning recess 6B of the rotating body 3 is formed in a conical shape or a wedge shape so that the positioning recess 6B is formed.
If the ball 7 is centered with the ball 7
Is positioned and fixed at a predetermined position.

Further, since the ball 7 itself is also held on the conical concave ball contact surface 6B of the ball pressing piston 6, the rotating body 3 can be positioned and fixed with high precision without rattling.

Next, the operation of releasing the positioning and fixing of the rotating body 3 is performed by switching the switching valve 10 to the second position for releasing the air pressure in the cylinder hole 2B to the outside. That is, when the switching valve 10 is switched to the second position, the air supply from the pressurized air source 11 is cut off,
The air pressure in the cylinder hole 2B is released to the outside, and the ball pressing piston 6 can move freely.

Therefore, when a small rotational force is applied to the rotating body 3, the ball 7 easily escapes from the concavity recess 3A, enters the cylinder hole 2B, and rotates the rotating body 3 freely. Can be.

Next, FIG. 3 is a sectional view showing a second embodiment of the air-operated ball plunger of the present invention.
Indicates a immersed state of the ball, and (b) indicates a protruded state. The basic operation principle of the ball plunger 21 of this embodiment is the same as that of the first embodiment described above, and includes a plunger housing 22, a ball pressing piston 26, a ball 27 and the like.

The ball pressing piston 26 has a cylindrical outer peripheral surface, and an O-ring 28 that seals a part of the outer peripheral surface with the inner peripheral surface of the cylinder hole 22 B of the plunger housing 22.
An annular groove 26 </ b> A is formed for mounting the groove.

The opening 22C of the cylinder hole 22B
A cylindrical depression C is formed in the end face of the ball pressing piston 26 facing the side, and a part of the ball 27 is fitted and supported therein.

The peripheral edge of the opening of the cylindrical recess C is a ball 27.
Is slightly smaller than the diameter of the ball pressing piston 26 so that the ball 27 does not fall off the ball pressing piston 26. The bottom surface of the cylindrical recess C is formed as a conical ball contact surface 26B, and the ball 27 can be slightly moved in the cylindrical recess C in the axial direction.

The periphery of the opening 22C of the cylinder hole 22B is narrowed down to a slightly smaller diameter than the outer diameter of the cylindrical ball pressing piston 26, so that the ball pressing piston 26 does not come out of the plunger housing 22. ing.

In this embodiment, since the outer diameter of the ball pressing piston 26 is larger than the diameter of the ball 27 and the pressure receiving area of the pressurized air is large, even when the pressure of the supplied pressurized air is small, the rotation The pressing force of the ball 27 against the positioning recess of the positioning member such as the body can be increased, and there is an advantage that the positioning and fixing can be performed reliably.

[0045]

As described above, according to the first aspect of the present invention, since the ball is fitted into the positioning recess of the member to be positioned by using air pressure, the ball is pressed against the positioning recess. The force can be adjusted freely.

When the positioning is released, the pressure of the ball against the member to be positioned can be released by releasing the air pressure in the plunger housing, so that the abrasion of the positioning recess formed on the ball and the member to be positioned is reduced. In addition, since the ball is brought into contact with the conical ball holding surface formed on the ball pressing piston and pressed against the positioning recess of the member to be positioned, rattling of the ball against the plunger housing can be suppressed. As a result, the member to be positioned can be reliably and accurately positioned and fixed for a long period of time.

Further, since the ball is operated by air pressure, the ball can be suitably used in equipment in an explosive atmosphere, food machines requiring a clean environment, and the like.

According to the second aspect of the present invention, since the maximum diameter portion of the ball pressing piston slidably fitted in the plunger receiving hole is formed larger than the ball diameter, a source of pressurized air is provided. Even when the supply pressure is low, the pressing force of the ball against the positioning recess of the member to be positioned can be increased, and the positioning can be reliably fixed.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of an air-operated ball plunger according to the present invention.
It is a figure showing an example.

FIG. 2 is an exploded sectional view of the air-operated ball plunger of the present invention.

FIG. 3 shows a second embodiment of the air-operated ball plunger of the present invention.
It is sectional drawing which shows an Example, (a) shows the immersion state of the ball, (b) shows the protruding state, respectively.

FIG. 4 is a diagram showing an example of a conventional ball plunger.

[Explanation of symbols]

1,21 ball plunger, 2,22 plunger housing, 2A male screw, 2B, 22B
Cylinder bore, 2C, 22C opening, 2D bottom,
2E Pipe connection screw hole, 3 rotating body, 4
Mounting member, 4A screw hole, 5 lock nut,
6, 26 Ball pressing piston, 6A, 26A
Annular groove, 6B, 26B Ball contact surface, 7, 27
Ball, 8, 28 O-ring, 9 air piping (air introduction path), 10 switching valve, 11 pressurized air source, C cylindrical recess.

Claims (2)

[Claims] A plunger housing having a bottomed cylinder hole opened to the outside, and an air introduction passage connected to an external pressurized air source in the cylinder hole, and a slide in the cylinder hole. A ball pressing piston, which is movably inserted and has a conical concave ball contact surface facing the cylinder hole opening side, and is provided so as to contact the ball contact surface of the ball pressing piston; A ball that is partially retractable from the inside of the cylinder hole to the outside of the opening. The ball pressing piston is pushed to the opening side of the cylinder hole with the ball by the pressurized air introduced into the cylinder hole from the air introduction path. The air-operated ball plunger is configured so that a part thereof protrudes from a cylinder hole opening. 2. A ball contact surface is formed as a bottom surface of a cylindrical concave portion formed on an end surface of the ball pressing piston facing the cylinder hole opening side, and a part of the ball is fitted and held in the cylindrical concave portion. An air-operated ball plunger.