JPH0565909A - Air pressure cylinder with intermediate stop mechanism - Google Patents

Abstract

PURPOSE:To provide an air cylinder with intermediate stop mechanism improved in locking efficiency. CONSTITUTION:An intermediate stop mechanism part 13 is provided with a piston rod 9 slidably inserted therein, and a brake metal 23 and a split bush 24, provided with slits 23a, 24a in the holdable state, into double pipe structure. A brake piston 25 provided slidably in the axial direction of the piston rod 9 so as to partition the inside into a spring chamber A1. and a brake release chamber A2 is energized to the brake release chamber A2 side by a brake spring 38 elastically mounted to the spring chamber A1 side. A holding member 30 with rolling bodies 32 disposed in such a way as to be rollable in contact with the outer periphery of the split bush 24 is fitted in the axially slidable state to the outer periphery of the split bush 24. The piston ring 25 is integrally provided with an inclined ring 35 having the inner peripheral surface 36 inclined in the opened state on the brake release chamber A2 side in correspondence with rolling bodies 32. There is further provided a spring 33 for energizing the holding member 30 in the anti-opening direction of the inner peripheral surface 36.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic cylinder with an intermediate stop mechanism for stopping the piston rod when the piston rod of the pneumatic cylinder is sliding or when the working air pressure is exhausted.

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Publication No. 57-43762 discloses an intermediate stopping mechanism of this kind. As disclosed in this publication, as shown in FIG. 4, a lock cylinder 102 provided in a fluid pressure cylinder 101 is attached via a spring 103 to a lock piston 104, which is attached to a lock piston 104. While pressing a plurality of balls 106, the balls 106 are further pressed by the piston rod 1
The brake shoe 108 slidably inserted through 07 is pressed to lock the piston rod 107.

[0003]

However, in the case of such a conventional structure, as shown in FIG.
06 is annularly arranged between a ring 109 provided on the outer peripheral surface of the brake shoe 108 and the tip of the cover 110. When the tightening body 105 moves in the direction of arrow A and the inclined surface 105a contacts the ball 106, a rotational force in the direction of arrow B acts on the ball 106, and the brake shoe 10 moves.
Trying to roll over 8. However, the ball 106 is not only in contact with the inclined surface 105a and the outer periphery of the brake shoe 108 but also pressed against the vertical surface 109a of the ring 109. Therefore, the ball 106 cannot roll on the brake shoe 108, large friction occurs between these surfaces, and the biasing force of the spring 103 is weakened by the torque due to the friction, and the ball 106 brakes the ball 106.
There is a problem in that the action force for pressing is weakened, and the efficiency for locking the piston rod 107 is poor.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above problems and to provide a pneumatic cylinder with an intermediate stop mechanism, which has improved locking efficiency.

[0005]

In order to achieve such an object, the present invention has the following constitution as a means for solving the problem. That is, a pneumatic cylinder with an intermediate stop mechanism, which is provided with an intermediate stop mechanism section that is connected to the pneumatic cylinder section and stops the piston rod, wherein the piston rod is slidable in the center of the intermediate stop mechanism section. A brake metal and a split bush, each of which has a slit through which the piston rod can be held and which can hold the piston rod, are provided in a double tubular shape, and the piston chamber is provided slidably in the axial direction of the piston rod. A brake piston that is divided into two parts is urged toward the brake release chamber by mounting a brake spring on the spring chamber side, and a rolling element that is in contact with the outer circumference of the split bush is rotatably arranged on the split bush. A member is fitted onto the piston rod so as to be slidable in the axial direction, and is provided on the outer periphery of the holding member on the side of the brake release chamber corresponding to the rolling element. An intermediate ring characterized in that an inclined ring having an inner peripheral surface inclined in an open state is provided integrally with the brake piston, and a spring for urging the holding member in a direction opposite to the inner peripheral surface of the brake piston is provided. That is the structure of the pneumatic cylinder with a stop mechanism.

[0006]

In the pneumatic cylinder with the intermediate stop mechanism having the above structure, when compressed air is supplied to the brake release chamber, the brake piston slides against the urging force of the brake spring,
Release the pressure of the rolling element by the inclined ring. The piston rod slides due to the action of compressed air in the pneumatic cylinder section.

On the other hand, when compressed air is exhausted from the brake release chamber, the brake piston slides toward the brake release chamber by the urging force of the brake spring. Then, the inner peripheral surface of the inclined ring contacts the rolling element, causes the rolling element to roll, and moves the holding member in the axial direction of the piston rod against the biasing force of the spring. In addition, the rolling element presses the piston rod through the split bush and the brake metal to lock the piston rod.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the drawings. In the figure, reference numeral 1 is a pneumatic cylinder with an intermediate stop mechanism, which is composed of a pneumatic cylinder section 2 and an intermediate stop mechanism section 13.

The pneumatic cylinder section 2 has a head cover 4 having ports 5 and 7 at both ends of a cylinder tube 3.
And an intermediate cover 6 are fitted to each other, a piston 8 is slidably fitted into the cylinder tube 3, and a piston rod 9 is attached to the piston 8. It is slidably inserted into an insertion hole 10 penetrating therethrough and extends toward the intermediate stop mechanism portion 13 side. A receiving recess 11 for a brake metal 23, which will be described later, is formed on the outer periphery of the insertion hole 10 on the surface of the intermediate cover 6 on the intermediate stop mechanism 13 side, and the intermediate stop mechanism 13 is formed on the outer periphery of the same surface. Receiving recess 1 into which the cylinder tube 22 is fitted
2 is formed.

Reference numeral 13 denotes the above-mentioned intermediate stop mechanism section,
The intermediate stop mechanism portion 13 is provided with a rod cover 14 facing the intermediate cover 6. This rod cover 14
Bosses 15 and 16 are formed on both sides of the center of the boss, and an insertion hole 17 through which the piston rod 9 is inserted is provided at the center of the boss. In addition, the insertion hole 1 of the boss portion 16
A receiving recess 18 of the brake metal 23 is formed on the outer circumference of the brake cover 7 in correspondence with the receiving recess 11 of the intermediate cover 6.

A ring-shaped convex portion 19 is formed on the outer periphery of the surface of the rod cover 14 on the boss portion 16 side, and a cylinder tube formed on the outer periphery of the intermediate cover 6 on the outer peripheral side of the convex portion 19. A receiving recess 20 is formed corresponding to the receiving recess 12 of 22, and a recess 21 is formed inside. A cylinder tube 22 is provided between the receiving recesses 12 and 20 between the rod cover 14 and the intermediate cover 6, and a brake metal 23 is provided between the receiving recesses 11 and 18 between the boss portion 16 and the intermediate cover 6. It is installed. Further, a split bush 24 is fitted on the outer periphery of the brake metal 23, and a brake piston 25 is slidably installed inside the cylinder tube 22.

Reference numeral 23 is the above-mentioned brake metal,
The brake metal 23 is made of a soft and wear-resistant material such as a bearing alloy, and is formed in a tubular shape having an inner diameter through which the piston rod 9 can be inserted, and a slit 23a is formed over the entire length in the axial direction. , The inner diameter of which can be reduced. In addition, the split bush 24
Is made of steel (heat treatable),
The brake metal 23 is formed in a tubular shape to be fitted onto the brake metal 23, and a slit 24a is formed over the entire length in the axial direction of the brake metal 23 so that the inner diameter can be reduced.

Reference numeral 25 denotes a brake piston, which is slidably guided in the piston chamber A formed by the cylinder tube 22 along the piston tube 22 and the boss portion 16, and is slidable via a brake spring 38. It is equipped with ammunition. In this brake piston 25, a piston body 26 that slides between the brake tube 22 and the boss portion 16 and a skirt portion 27 are integrally formed.
As a result, the piston chamber A becomes a spring chamber A1 and a brake release chamber A2.
It is divided into and. Further, a concave portion 28 having a predetermined width is provided on the inner peripheral surface of the skirt portion 27, and a brake operating portion 29 is interposed between the concave portion 28 and the split bush 24.

Reference numeral 30 denotes a holding member for the brake actuating portion 29, which is formed in a tubular shape so as to be slidably fitted on the outer circumference of the split bush 24. The holding member 30 is made of a steel ball in this embodiment. A plurality of rolling elements 32 used are formed in a substantially annular shape, and a plurality of rows (in this embodiment, three rows are illustrated) r1,
Since the rolling elements 32 are arranged in r2 and r3,
A receiving hole 30 is provided so as to be rollably received while being in contact with the outer periphery of the. The inner thickness of the holding member 30 is formed such that a part of the rolling element 32 protrudes from the outer periphery of the holding member 30 by a predetermined height when the rolling element 32 is housed in the receiving hole 31.

A spring 33 is interposed between the holding member 30 and the piston body 26 provided in this way, and the holding member 3 is provided.
0 is urged in the anti-expansion direction of the inner peripheral surface 36 described later. In addition, the concave portion 2 formed on the inner peripheral surface of the skirt portion 27
A tubular elastic body 34 made of, for example, synthetic rubber or the like is fitted to the inner wall of the recessed portion 8, and a plurality (in this example, a plurality of rows r1, r2, r3) of the plurality of rolling elements 32 are arranged inside the recess 28. The tilt ring 35 (three illustrated) is housed.

The inclined ring 35 is made of, for example, a steel material (which can be heat-treated) or the like, has an outer diameter of a predetermined diameter, and an inner diameter of the brake opening chamber A2 as shown in the drawing.
A substantially cone-shaped inner peripheral surface 36 that is inclined at a predetermined angle in a widened manner is formed on the side, and a slit 37 is provided in a part of the inner peripheral surface 36 so that the diameter can be increased or decreased. In this way, the brake piston 2 in which the brake operating unit 29 is interposed
5 is slidably mounted by a brake spring 38 and is urged toward the brake release chamber A2, and the spring chamber A1 defined by the piston 25 has an exhaust hole 39 provided in the intermediate cover 6.
Is vented to the atmosphere through the brake release chamber A2
Is a brake release port 4 provided on the rod cover 14.
It is connected to 0.

Next, the operation and effect of this embodiment configured as described above will be described. The forward / backward movement of the piston rod 9 is performed forward / backward by supplying / discharging compressed air from the ports 5 and 7. During the forward / backward movement of the piston rod 9, the compressed air supply source of the same system as the pneumatic cylinder unit 2 is used. Compressed air is supplied to the brake release chamber A2 from the brake release port 40, and the brake piston 25 is pushed against the brake spring 38 toward the intermediate cover 6 side and stopped in a state of being in contact with the intermediate cover 6. Then, the plurality of inclined rings 35 fitted in the recesses 28 formed on the inner peripheral surface of the skirt portion 27 of the brake piston 25 are also moved integrally.

On the other hand, the holding member 30 is urged by the spring 33 and is in contact with the intermediate cover 6 in the same manner. In this case, each rolling element 32 and the inner peripheral surface 36 of each inclined ring 35 are in contact with each other. The brake metal 23 and the split bush 2 are in contact with each other or separated from each other with a slight gap.
The widths of the slits 23a and 24a of No. 4 are also kept in the normal state, the piston rod 9 is slidable, and the stop is released.

When the compressed air in the brake release chamber A2 is exhausted in the state where the stop is released, the brake piston 25 is moved to the brake release chamber A2 side by the brake spring 38, and the tilt ring 35 is also moved integrally. To be done. Due to the movement of the brake piston 25, the rolling element 32, which faces the inclined ring 35, comes into contact with the inner peripheral surface 36 of the inclined ring 35, and the contact state shifts from the large diameter side to the small diameter side.

In this process, the rolling element 32 is passed through the inner peripheral surface 36.
In addition, in accordance with the biasing force of the brake spring 38, a horizontal component force in the axial direction of the piston rod 9 and a large vertical component force in the radial direction due to the wedge effect act. By the action of this horizontal component force, the rolling element 32 rotates in the direction of arrow D and rolls on the split bush 23, as shown in FIG. And the holding member 3
0, and the holding member 30 slides in the axial direction of the piston rod 9 against the biasing force of the spring 33.

Further, the rolling direction of the rolling element 32 is a direction in which the rolling element 32 moves in a small diameter direction with respect to the inner peripheral surface 36, and the rolling element 32 relatively moves in the small diameter direction of the inner peripheral surface 36.
As a result, the vertical component force that acts on the rolling elements 32 increases. The vertical component force acting on the rolling element 32 presses the outer circumference of the split bush 24 in the radial direction.

As the rolling element 32 moves in the direction of the smaller diameter of the inner peripheral surface 36, the vertical component force increases, and the brake spring 3
When the urging force of No. 8 and the resistance of the rolling element 32 against the rolling in the small diameter direction are in a balanced position, the rolling of the rolling element 32 stops. Due to the large vertical component force at this time, the outer circumferences of the split bush 24 and the brake metal 23 are pressed to reduce the widths of the slits 24a and 23a, and the outer circumference of the piston rod 9 is pressed into a grip shape to cause friction resistance to the piston rod. 9 is stopped and locked.

On the other hand, when compressed air is supplied to the brake release chamber A2 in this state, the brake piston 25 is pushed toward the intermediate cover 6 side against the brake spring 38, and stops in the state of contacting the intermediate cover 6. To be done. At this time, the rolling elements 32 are in contact with the inner peripheral surface 36 of the inclined ring 35 or are separated with a slight clearance, and the widths of the slits 23a, 24a of the brake metal 23 and the split bush 24 are also normal. The lock is released by returning to the state of.

At this time, the holding member 30 is pushed toward the intermediate cover 6 side by the urging force of the spring 33, the rolling element 32 rolls on the split bush 24, and the holding member 32 abuts on the intermediate cover 6. Then, the initial state is restored. The spring 3
It is sufficient for 3 to have a small biasing force that can move the holding member 30 to the side of the intermediate cover 6. In this way, by biasing the holding member 30 with the spring 33, the rolling element 32 is returned to the initial state, and the brake piston 25 is repeatedly slid to repeatedly lock and release the piston rod 9. The rolling element 32 does not roll on the split bush 24 and continuously move in the axial direction of the piston rod 9.

In this way, by exhausting the compressed air in the brake release chamber A2, the piston rod 9 can be stopped at any position of the reciprocating operation. Further, this means that the piston rod 9 can be stopped even when the supply operation of the compressed air supply source is stopped for some reason, and when the compressed air supply source is restored, the piston rod 9 is transferred to the pneumatic cylinder section 2. At the same time that the compressed air is supplied, the compressed air is also supplied to the brake release chamber A2, the stopped state is immediately released, and the piston rod 9 is operated.

Therefore, in the pneumatic cylinder with the intermediate stop mechanism of this embodiment, the rolling element 32 is allowed to freely roll. Therefore, when the piston rod 9 is locked, the rolling element 32 is set in the inclined ring 35. It abuts the peripheral surface 36, rolls on the split bush 24, and moves from the large diameter side of the inner peripheral surface 36 to the small diameter side. Then, at a position balanced with the brake spring 38, the movement is stopped while being sandwiched between the inner peripheral surface 36 and the split bush 24.

A large vertical component force corresponding to the urging force of the brake spring 38 acts on the split bush 24 and the brake metal 23 via the rolling elements 32. At this time, the holding member 30
Comes into contact with the rolling elements 32 by the urging force of the springs 33, but the urging force of the springs 33 is weak and the rolling elements 32 and the holding member 3
The frictional force between 0 and 0 does not weaken the acting force that presses the brake metal 23 toward the center, and the efficiency for locking the piston rod 9 does not decrease.

The present invention is not limited to the embodiments as described above, and can be carried out in various modes without departing from the scope of the present invention.

[0029]

As described above in detail, in the pneumatic cylinder with the intermediate stop mechanism of the present invention, the rolling elements are arranged so that they can roll. Therefore, when locking, the rolling elements roll on the split bush,
Stop at a position that balances with the urging force of the brake spring. Therefore, since the vertical component force acting on the split bush and the brake metal is not reduced by the frictional force between the rolling element and the holding member, the efficiency for locking the piston rod is improved. Produce an effect.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a pneumatic cylinder with an intermediate stop mechanism as an embodiment of the present invention.

FIG. 2 is a sectional view taken along line EE of FIG.

FIG. 3 is an enlarged cross-sectional view of a brake actuating portion of this embodiment.

FIG. 4 is a partial cross-sectional view showing a conventional example.

FIG. 5 is an enlarged cross-sectional view of a conventional tightening body, ball, ring, and brake shoe.

[Explanation of symbols]

1 ... Pneumatic cylinder with intermediate stop mechanism 2 ... Pneumatic cylinder section 9 ... Piston rod 13 ... Intermediate stop mechanism section
23 ... Brake metal 23a ... Slit 24 ... Split bush
24a ... Slit 25 ... Brake piston 26 ... Piston body
27 ... Skirt part 29 ... Brake operating part 30 ... Holding member
32 ... Rolling element 33 ... Spring 35 ... Inclined ring
36 ... Inner peripheral surface 38 ... Brake spring

Claims (1)

[Claims] 1. A pneumatic cylinder with an intermediate stop mechanism, which is provided with an intermediate stop mechanism portion that is connected to an air pressure cylinder portion to stop a piston rod, wherein the piston rod is slid at the center of the intermediate stop mechanism portion. A brake metal and a split bush, each of which has a slit so that the piston rod can be held movably and which can hold the piston rod, are provided in a double tubular shape. A brake piston that is partitioned into an open chamber is mounted on the spring chamber side to urge the brake spring toward the brake open chamber side, and at the same time, a rolling element that is in contact with the split bush and the outer circumference of the split bush can be rolled. The arranged holding member is externally fitted so as to be slidable in the axial direction of the piston rod, and the brake is opened on the outer periphery of the holding member in correspondence with the rolling element. An inclined ring having an inner peripheral surface that inclines in a diverging manner on the chamber side is integrally provided on the brake piston, and a spring for urging the holding member in the anti-expansion direction of the inner peripheral surface is provided. A pneumatic cylinder with an intermediate stop mechanism.