JP2662817B2 - Cylinder stop device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a cylinder stopping device that locks and stops a piston rod of a hydraulic cylinder at an arbitrary position.

<Prior art> The present inventors have disclosed JP-A-59-83810 and JP-A-61-233.
Japanese Patent Publication No. 209 proposes a cylinder stopping device that can lock a piston rod of a fluid pressure cylinder at an arbitrary position without deformation of the rod or wear of a bearing.

This cylinder stopping device axially divides a thick cylinder having an eccentric outer peripheral portion and an inner peripheral portion into a maximum thickness portion and a minimum thickness portion to form two semi-cylindrical brake members. The brake member is rotatably disposed in the housing, the piston rod is disposed inside the two brake members, and the semi-cylindrical brake members are rotated in mutually opposite directions by a coil spring or the like, thereby rotating the piston rod. It is configured to lock.

<Problem to be Solved by the Invention> The cylinder stopping device having the two semi-cylindrical brake members can reliably lock the piston rod without giving a problem such as shearing force to the piston rod. Because the members are locked by the force of the coil spring, the size of the coil spring increases, and the actuator that moves in the direction to release the lock against the urging force of the coil spring also increases in size. Will protrude from Further, since high-precision machining is required for the semi-cylindrical brake member, there is a problem that the machining of the member is costly.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and a cylinder stop that can reduce the size of a coil spring for urging a brake member in a locking direction, has a simple structure, and can easily process a member. It is intended to provide a device.

<Means for Solving the Problems> In order to achieve the above object, a cylinder stop device of the present invention is provided with an eccentric brake member formed in the form of a friction wheel in the form of a continuous wheel, and is eccentrically supported by a shaft. An eccentric brake member is disposed at right angles to the axial direction of the rod so as to sandwich both sides of the piston rod and to be able to contact the outer periphery of the rod, and the thicker portions of the eccentric brake members on both sides enter between the piston rod and the eccentric brake member. A spring for biasing the eccentric brake member in the direction in which the spring is biased, and an actuator for releasing the brake by rotating the eccentric brake member in a direction opposite to the direction in which the spring is biased is provided. .

<Operation> The spring urges the eccentric brake member to rotate in a direction to press the eccentric brake member against the outer peripheral portion of the piston rod when the actuator is not operated. For this reason, when the piston rod attempts to move in the direction opposite to the eccentric direction of the eccentric brake member, the eccentric brake members on both sides rotate so as to follow the eccentric brake member, and the thicker portion enters between the eccentric brake member and the piston rod. It acts like a bite. Accordingly, the piston rod is strongly pinched and locked by the eccentric brake members on both sides, and stops.

On the other hand, when the eccentric brake member is rotated in the direction opposite to the biasing direction of the spring by the operation of the actuator, a gap is generated between the piston rod and the eccentric brake member, or the frictional resistance therebetween becomes extremely small, and the piston rod is eccentric. The brake is released when it is possible to freely move between the brake members.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view of a cylinder stopping device mounted on the hydraulic cylinder 20, and FIG. 2 is a longitudinal sectional view thereof.

Numeral 9 denotes a box-shaped casing, which is fixed to the front end of the fluid pressure cylinder 20, and is arranged in the casing 9 so as to sandwich a piston rod 21 projecting from the cylinder as shown in the sectional view of FIG. A pair of eccentric brake members 1, 1 of a conical friction wheel type provided and a hydraulic actuator 10 for urging the eccentric brake members 1, 1 in a brake releasing direction are provided.

A pair of eccentric brake members 1, 1 of a conical friction wheel type
A pair of shafts 2, which have a hook-shaped body which abuts with a curved surface having the same curvature as the outer peripheral surface of the piston rod 21, and is provided on both sides of the piston rod 21 in a direction perpendicular to the rod, that is, vertically. 2 eccentrically fixed on its axis 2, 2
The upper and lower parts of the casing 9 are rotatably supported by metal bearings. The eccentric brake members 1 and 1 are made of metal, and are eccentric to the right (return direction of the piston rod 21) with respect to the shafts 2 and 2 in a plane (FIG. 1).

Pins 3, 3 are horizontally protruded from the upper portions of the outer circumferences of the shafts 2, 2, respectively. A small coil spring 4 is pulled between the pins 3, 3 to pull the shafts 2, 2 and the eccentric brake member. Hooks 1 and 1 are turned in the direction of the arrow in FIG. That is,
A coil spring 4 is hung on the pins 3 and 3 so that the shafts 2 and 2 are rotated in a direction in which a thicker portion of the eccentric brake members 1 and 1 enters the piston rod 21 (a direction in which braking is applied). Can be

Further, just above the eccentric brake members 1, 1 on the outer peripheral portions of the shafts 2, 2, other pins 5, 5 are erected horizontally facing each other inward. The pins 5, 5 are pushed rightward in the figure by the actuator 10, and the shafts 2, 2, that is, the eccentric brake members 1, 1 are moved in the direction opposite to the biasing direction by the coil spring 4 (brake release direction). Operate to rotate.

Actuator 10 arranged at the front in casing 9
Is constructed by inserting a piston 11 movably along a piston rod 21 into a cylinder portion formed in a casing, and an elongated operating piece 12 is inserted at the tip of the piston 11 into pins 5, 5 of the eccentric brake members 1, 1. Protruding toward. A coil spring for biasing the piston 11 to the left (in the direction opposite to the pins 5, 5) in FIGS.
13 are arranged. Pressurized air is introduced into the cylinder portion of the actuator 10 from an upper air supply port 14, and the piston 11 moves to the right by this pressure, and the operating piece 12 at the tip of the piston 11 pushes the pins 5, 5 to push the shafts 2, 2. That is, the eccentric brake members 1 and 1 are rotated in the brake release direction.

Further, a metal bearing 15 for slidably supporting the piston rod 21 and a packing 16 for sealing a sliding portion of the piston rod 21 are provided in the casing 9.

When the actuator 10 is not operated, the eccentric brake members 1 and 1 push the piston rod 21 of the hydraulic cylinder 20 in the direction in which the piston rod 21 is pushed out (to the left in FIGS. 1 and 2). Only lock and stop.

That is, as shown in FIG. 4, when the piston rod 21 receives an operating force in the leftward direction, that is, in the pushing direction, the eccentric brake members 1, 1 are driven to move the thicker portion into the space between the piston rod 21 and the piston rod. Act on. By this,
A large frictional force is generated between the eccentric brake members 1 and 1 and the piston rod 21, and the outer periphery of the piston rod 21 is locked so as to be clamped from both sides, so that the movement of the piston rod 21 in the pushing direction is completely locked.

The coil spring 4 only urges the shafts 2 and 2, that is, the eccentric brake members 1 and 1 with a weak force in the direction of the arrow in FIG. 4 and only presses the eccentric brake members 1 and 1 against the piston rod. It does not directly generate braking force.

On the other hand, when releasing the brake, pressurized air is supplied to the air supply port 14 of the actuator 10, and the piston 11 is moved rightward in FIG. As a result, the operating piece 12 at the tip moves in the same direction and pushes the pins 5, 5, and the eccentric brake members 1, 1 are moved in the direction of the arrow in FIG. 4 through the pins 5, 5, as shown in FIG. Is rotated in the opposite direction to reduce the friction between the eccentric brake members 1 and 1 and the piston rod 21 (or to create a gap between them).

Thus, the piston rod 21 of the fluid pressure cylinder 20 can be freely pushed out (retracted).

When the fluid pressure cylinder 20 operates by air pressure, the pressure air supplied to the actuator 10 when the brake is released can use the air pressure supplied for the pushing operation to the cylinder as it is, and the conventional cylinder stopping device On the other hand, there is an advantage that the electromagnetic switching valve for operating the actuator and the air line can be simplified.

In the above embodiment, the piston rod 21 is locked when it is pushed out. However, if the eccentric direction of the pair of eccentric brake members 1 is reversed and the direction of the actuator is reversed, the piston rod 21 is pulled back. It can be designed to lock it only in the direction. in this way,
A stop device that locks the movement of the piston rod only in one direction is, for example, a hydraulic cylinder installed vertically,
It is used only when the piston rod moves downward due to the gravity and when it is necessary to apply the brake.

FIG. 6 shows another embodiment. In this cylinder stopping device, a pair of the above eccentric brake members is further provided so that the piston rod 21 can be locked in both directions of movement.

In the casing 30 of this stopping device, an actuator is provided.
The two pairs of eccentric brake members 1, 1 and 31, 31 are arranged opposite to each other with 40 interposed therebetween. That is, the pair of eccentric brake members 1 and 1 are disposed in the casing 30 in exactly the same manner as described above, and the other pair of eccentric brake members 31 and 31 are locked on the left side of the actuator 40 when the piston rod 21 is pulled back. In such a manner, the piston rod 21 is supported by a shaft 32 so as to sandwich the piston rod 21 in the casing 30.

Each eccentric brake member 31 has exactly the same shape and structure as the eccentric brake member 1, and as shown in FIG. 6, a pair of eccentric brake members 31, 31 is composed of a pair of right eccentric brake members 1, 1, the pin 33 and the coil spring 34 are arranged so as to face the distal end of the piston rod 21.

The actuator 40 is inserted into a cylinder portion formed in the casing 30 so as to move the two pistons 41 and 42 to both sides, and an air supply port 49 is provided at a central portion. On the both ends of the pistons 41 and 42, elongated operating pieces 43 and 44 are respectively provided toward the pins 5, 5 and the pins 35 and 35, and the coil springs 45 and 46 return the pistons 41 and 42 to the center. It is arranged to urge in the direction.

When the piston rod 21 of the fluid pressure cylinder 20 receives a force to move in the pushing direction in a state where the pressurized air is not supplied to the actuator 40, the eccentric brake members 1, 1 are driven to move as shown in FIG. The thicker portion acts to bite between the piston rod 21 and the piston rod 21 is locked and stopped. Also, when the piston rod 21 tries to move in the retraction direction, the tip 1
The pair of eccentric brake members 31, 31 act to bite the thicker portion between the eccentric brake members 31 and the piston rod 21 in the same manner as described above, and the piston rod 21 is locked.

On the other hand, when pressurized air is supplied from the air supply port 49, the pistons 41, 42 of the actuator 40 move in the left and right directions in FIG. 6, and the pins 5, 35 are moved right and left by the respective operating pieces 43, 44. Press Then, the shafts 2 and 2 rotate in the direction opposite to the arrow in FIG. 4, and the shafts 32 and 32 further rotate in the opposite direction to the eccentric brake members 1, 1 and 3 eccentrically supported by them.
1 and 31 are not in contact with the piston rod 21, or the frictional resistance therebetween is extremely reduced. Thus, the brake is released, and the piston rod 21 can move in both directions.

As the coil spring 4 for urging the eccentric brake member 1, another spring such as a compression coil spring can be used. For example, the eccentric brake member is pressed between the pin 3 and the casing 9 against the outer peripheral surface of the rod. It may be urged in the direction, or may be urged directly to a part of the eccentric brake member 1 without being applied to the pin 3 protruding from the shaft 2. In addition, actuator 10, 40
Alternatively, the eccentric brake member may be rotated in the brake release direction using an engagement member or a link member other than the operating piece and the pin.

<Effects of the Invention> As described above, according to the cylinder stopping device of the present invention, the eccentric brake member formed in the form of a friction wheel is eccentrically supported by the shaft, and the pair of eccentric brake members is connected to the piston rod. The eccentric brake is disposed at right angles to the axial direction of the rod so that both sides of the eccentric brake member can be in contact with the outer peripheral portion of the rod, and the thicker portions of the eccentric brake members on both sides enter the gap between the eccentric brake member and the piston rod. A spring for biasing the member is provided, and an actuator for releasing the brake by rotating the eccentric brake member in a direction opposite to the direction in which the spring is biased is provided. If the eccentric brake member moves in the braking direction, the eccentric brake members on both sides are driven to move so that the thicker portion of the member bites into the piston rod. As a result, the eccentric break members on both sides are strongly pinched and locked.

As described above, since the piston rod is applied with its own moving force as a strong braking force and is braked, there is no need to apply a strong braking force from others. Therefore, since the spring for urging the eccentric brake member toward the brake side does not directly apply a braking force, the spring can be made extremely small and weak, and accordingly, the eccentric brake member is opposed to the spring. Accordingly, the actuator that urges the brake release side can be downsized, and the entire stop device can be downsized.

Further, since the piston rod is consequently braked so as to be clamped from both sides by the eccentric brake member, no bending force or twisting force which adversely affects the rod is generated on the piston rod. Further, the machining accuracy of the eccentric brake member and the like is not required to be so high, and the eccentric brake member can be easily and inexpensively manufactured.

[Brief description of the drawings]

Fig. 1 shows an embodiment of the present invention. Fig. 1 is a plan view of a cylinder stopping device, Fig. 2 is a sectional view thereof, Fig. 3 is a sectional view taken along line III-III of Fig. 2, and Fig. 4 is Fig. 2. 5 is a cross-sectional view when the brake is released, and FIG. 6 is a cross-sectional view of another embodiment. 1 ... eccentric brake member, 2 ... shaft, 3 ... pin, 4 ...
... Coil spring, 5 ... Pin, 10 ... Actuator, 21
…… Piston rod.

Claims (2)

(57) [Claims] An eccentric brake member formed in the form of a friction wheel with an eccentric shape is eccentrically supported by a shaft, and a pair of the eccentric brake members abut both sides of a piston rod and abut against an outer peripheral portion of the rod. A spring is disposed at right angles to the axial direction of the rod, and biases the eccentric brake member in a direction in which thicker portions of the eccentric brake members on both sides enter the piston rod. And an actuator for releasing the brake by rotating the eccentric brake member in a direction opposite to a direction in which the spring is urged. 2. The eccentric brake member of two pairs is pivotally supported along both sides of the piston rod, and the eccentric brake members of each pair are disposed in directions opposite to each other in the eccentric direction. The cylinder stopping device according to claim 1, wherein