JPH0735149Y2 - Wire clamp device - Google Patents

Description

[Detailed description of the device]

[0001]

This invention relates to a wire clamp device.

[0002]

2. Description of the Related Art Some conventional wire clamp devices utilize the basic structure of the clamp device of Japanese Patent Application No. 60-299423. This wire clamp device is configured by internally fitting a cylindrical shrink sleeve in a cylinder tube and inserting a collet through which the wire rope is inserted into the inner circumference of the shrink sleeve.

The shrink sleeve described above is configured such that one peripheral portion is axially notched, and ends of the notches are slidably overlapped in the circumferential direction so that the shrink sleeve expands and contracts in the circumferential direction. I am doing it. In addition, the collet inserted into the inner circumference of the shrink sleeve is divided into a plurality of unit collets so that the collet can be expanded and shrunk, and the wire rope inserted into the collet is tightened from the outer circumference when contracted. is there.

Then, by applying hydraulic pressure between the shrink sleeve and the inner circumference of the cylinder tube, the shrink sleeve is compressed from the outer circumference, and further the collet inside the sleeve is shrunk so that the wire rope inserted through the collet is inserted. It is configured to clamp.

In addition, a spiral engagement groove that matches the unevenness of the twist pattern formed on the outer circumference of the wire rope is formed on the inner circumference of each unit collet constituting the above collet, and as described above. At the time of tightening the wire rope, the engaging groove is matched with the outer shape of the wire rope so that the wire rope is clamped surely.

[0006]

However, in the wire clamp device configured as described above, since each unit collet divided in the unloaded state is configured to rotate, expansion and contraction of the collet is prevented. During the repetition, the positional relationship in the circumferential direction may be displaced between each unit collet and the wire rope inserted therein. Therefore, when the wire rope is clamped next time, the engagement groove formed on the inner peripheral surface of each unit collet and the unevenness of the twist pattern formed on the outer circumference of the wire rope will not match, which will prevent reliable clamping. The wire rope may slip.

Further, since the collet and the contraction sleeve in which the collet is fitted can freely move in the oil chamber of the cylinder tube, even when the contraction sleeve moves from a fixed position, even the shaft core portion through which the wire rope is inserted. There was a problem that was displaced.

Further, the wire clamp device described above often clamps a wire rope or the like for lifting a heavy object, but since the collet is tightened only by hydraulic pressure, there is a hydraulic leak or a hydraulic system leak during clamping. If a breakage occurs, the tightening by the collet will be loosened and a heavy object will fall, so some kind of safety mechanism should be provided to cope with the drop in hydraulic pressure.

It is an object of the present invention to provide a wire clamp device with a means for tightening a collet which does not change the positional relationship between the unit collet and the wire rope in the process of tightening and releasing, thereby making it possible to prevent slippage. This is to realize a strong and stable clamp and to equip it with a safety mechanism that can cope with a drop in hydraulic pressure during clamping.

[0010]

In order to solve the above-mentioned problems, the wire clamp device of the present invention has a hollow piston rod which is reciprocated by hydraulic pressure inserted into a cylinder tube, and a cone is attached to the inner circumference of the piston rod. A tapered conical surface is formed, and a conical trapezoidal collet that matches the conical tapered surface and is divided into a plurality of unit collets and can be expanded and contracted in the radial direction is inserted into the piston rod. An engagement groove is formed on the inner peripheral surface of each unit collet to match the outer shape of the twist pattern formed on the outer circumference of the wire rope, and the end of the piston rod on the large diameter end side is extended to form a cylinder tube. The lock nut is screwed outside the protruding portion of the piston rod.

[0011]

According to the above means, a hollow piston rod is inserted in the cylinder tube, and further, a conical trapezoid of a plurality of unit collets is divided into a conical tapered surface of the inner circumference of the piston rod. The collet is inserted in a matched state, and the three axes of the cylinder tube, the piston rod, and the collet are maintained in a matched state.

The large-diameter side end of the piston rod is extended and protrudes from the cylinder tube, and a lock nut is screwed into this protrusion. Further, the lock nut moves in the axial direction by being rotated, and comes into contact with the end surface of the cylinder tube when the piston rod moves to the smaller diameter side.

When the piston rod moves toward the end on the small diameter side of the collet, a lock screwed to the outside of the protrusion contacts the end surface of the cylinder tube. The wire rope is inserted into the collet so that it can be pulled in the direction of the small diameter of the conical tapered surface.

When the piston rod is moved toward the larger diameter side of the collet by the hydraulic pressure applied to the tightening side in the cylinder tube, the inner diameter of the conical tapered surface formed on the inner circumference of the piston rod is changed. The collet moves toward the smaller diameter side, whereby the collet is compressed from the outer periphery and each unit collet contracts, and the wire rope inserted into the collet is tightened.

An engaging groove is formed on the inner peripheral surface of each unit collet described above, and in the clamped state, the engaging groove and the outer shape of the twist pattern formed on the outer periphery of the wire rope inserted through the collet are matched. In this condition, the collet tightens.

Further, when the lock nut screwed to the outside of the protruding portion of the piston rod is rotated and brought into contact with the end surface of the cylinder tube while the collet is tightened, the movement of the piston rod is restricted in the tightened state. The collet fitted and inserted in the conical tapered surface of the piston rod is also locked in a clamped state. For example, even if the hydraulic pressure that pressurizes the piston rod toward the tightening side in the locked state decreases, the piston rod maintains the tightened state by the support by the lock nut, and the clamp is prevented from loosening.

The lock nut in the above state is unlocked by moving the piston rod in the tightening direction until the lock nut floats from the end surface of the cylinder tube and then turning it back toward the end of the protruding portion.

On the contrary, when the piston rod moves toward the small diameter side of the collet due to the hydraulic pressure applied to the return side in the cylinder tube, the inner diameter of the fitting portion of the conical tapered surface of the inner circumference of the piston rod moves toward the large diameter side. After the transfer, each unit collet is expanded and the tightening of the wire rope by the collet is released.

As described above, even when the piston rod moves, the collet inserted into the conical taper surface of the piston rod in a state of matching with the conical taper surface expands and contracts radially in accordance with the transition of the conical taper surface. However, there is no change in the positional relationship between the collet and the wire rope.

The tightening force by the collet increases / decreases in inverse proportion to the inclination angle of the conical taper surface, while the reaction force from the wire rope applied from the collet to the piston rod increases / decreases in proportion to the inclination angle. To be done. Therefore,
By setting the inclination angle of the conical taper surface to a sufficiently small value, the tightening force of the collet generated for a certain hydraulic pressure can be increased, and conversely it acts to return the piston rod via the collet. The reaction force from the wire rope can be reduced.

Further, the wire rope inserted into the collet is pulled toward the small diameter direction of the conical taper surface by the tensile load, but once the tensile load is applied to the wire rope, the load is the collet in the clamped state. Since the conical tapered surface acts like a wedge on the small diameter side, the tightening force by the collet is strengthened in proportion to the tensile load applied to the wire rope.

[0022]

Since the present invention is constructed as described above, it has the following effects.

Since the collet does not rotate when the collet is expanded and contracted by the hydraulic movement of the piston rod, the position between each unit collet and the wire rope is repeated in the process of repeatedly clamping and releasing the wire rope. It is possible to prevent the relationship from changing, thereby always maintaining the matching state between the engagement groove on the inner circumference of the unit collet and the outer shape of the twist pattern formed on the outer circumference of the wire rope,
A reliable clamp that does not slip can be performed.

Further, since the tightening of the wire rope by the collet can be mechanically locked by providing the lock nut for restricting the movement of the piston rod in the clamped state, the hydraulic pressure is lowered during the clamping, for example. Even in such a case, the lock by the lock nut can prevent the wire clamp from loosening and ensure work safety.

The tightening performed through the conical taper surface of the inner circumference of the piston rod can effectively give a large tightening force to the collet due to the wedge effect, and the tensile load applied to the wire rope is in the clamped state. Since the collet on the side of the cone acts like a wedge into the conical taper surface to act to further strengthen the tightening force of the collet, the clamp is securely prevented from loosening even when a high tensile load is applied. be able to.

Since the axes of the cylinder tube, the piston rod and the collet are inevitably aligned,
The wire rope to be inserted into the collet can be clamped at the shaft core at all times.

Further, the reaction force acting to return the piston rod through the collet which receives the tensile load of the wire rope in the clamped state can be reduced by the reverse wedge effect, so that the damage of the jack due to the reaction force can be suppressed. be able to.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

1 to 3 show a wire clamp device embodying the present invention, in which a hollow piston rod 2 which reciprocates by hydraulic pressure is fitted inside a cylinder tube 1, and a wire rope a is inserted in the piston rod 2. The collet 3 for tightening is attached and configured.

The cylinder tube 1 is formed in a cylindrical shape, and a receiving seat 4 having a base plate 4a for installation at one end thereof is coupled by bolting, and a hair ring cover 5 is provided at the other end of the cylinder tube 1, and the cover is provided. Flange 5a of 5
The outer peripheral portion of the cylinder tube 1 and the outer peripheral portion of the end surface of the cylinder tube 1 are connected by eight connecting rods 12 to form a device main body through which the shaft core portion passes.

A ring-shaped guide 1a is screwed into one end of the cylinder tube 1 so that the piston rod 2 is slidably inserted into the cylinder tube 1 and a guide hole 1b. Larger diameter cylinder chamber 1
c is formed. Then, a tightening port port 10a and a return port port 10b for communicating with a hydraulic pressure source (not shown) are bored in the outer peripheral portion of the cylinder tube 1, and these are communicated with one end and the other end of the cylinder chamber 1c. I am allowed.

The piston rod 2 fitted in the above-mentioned cylinder tube 1 is formed in a hollow shape, and a conical tapered surface 2b is formed on the inner circumference of the piston rod 2 so as to expand from one end to the other end. Then, the guide hole 1b of the cylinder tube 1
A piston 2a having a large diameter is formed approximately at the center of the outer peripheral portion to be fitted with, and the piston 2a is reciprocally slidably inserted into the cylinder chamber 1c.

The O-rings 11a and 11b are mounted on the outer peripheral portion of the piston 2a and the inner periphery of the guide hole 1b of the cylinder tube 1, respectively.
11b keeps the oiltightness of the sliding surface between the inner circumference of the cylinder tube 1 and the outer circumference of the piston rod 2.

Further, the other end of the piston rod 2 is extended so as to project from the end of the cylinder tube 1, and a ring-shaped lock nut 16 is screwed into a threaded portion provided on the outer periphery of the projecting portion 2c. is there. An insertion hole 16a is formed on the outer periphery of the lock nut 16, and a rod-shaped tool is inserted through the insertion hole 16a to insert the lock nut 1 from between the connecting rods 12.
6 can be rotated. The lock nut 16
Is configured to come into contact with the end surface of the cylinder tube 1 by tightening toward one end.

A collet 3 is inserted inside the conical tapered surface 2b formed on the inner circumference of the piston rod 2.

As shown in FIGS. 3 and 4, the collet 3 has a conical tapered surface 2b on the inner circumference of the piston rod 1 described above.
Is formed in a truncated cone diameter that matches with the above, and the shaft core portion is formed with an insertion hole 3a through which the wire rope a is inserted, and the vertical dividing groove 3b is formed in a cross shape so as to be equally divided in the circumferential direction. The unit collet 3'is divided and configured.

Each unit collet 3'is provided with a vertical dividing groove 3b.
The fixing pin 7 and the spring 8 are connected by being fitted and inserted between the joint surfaces facing each other with the pin in between, and in this state, the fixing pin 7 and the spring 8 are inserted in the conical taper surface 2b of the cylinder tube 1 in an elastic state, The cylinder tube 1 is held so that it can be expanded and contracted in the radial direction.

The collet 3 constructed as described above is loosely fitted to the bearing 13 of the bearing holding cover 4b in which the shaft support portion 3c at one end is integrally fitted to the seat 4, and at the other end. The bearing 3 is attached to the shaft support 3d.
By similarly inserting the bearing 12 provided inside, the radial holding at both ends is performed.

At the same time, the collet 3 brings the end face of the support portion 3c at one end into contact with the thrust bearing 15 mounted in the holding cover 4b of the receiving seat 4, and the end face of the outer peripheral portion at the other end. By abutting on one end surface of the bearing 5, it is sandwiched between the thrust bearing 15 and the bearing cover 5, and movement in the thrust direction is prohibited.

An engagement groove 9 is formed on the inner peripheral surface of the insertion hole 3a formed along the axial center of the collet 3. The engaging groove 9 is a spiral groove that matches the outer shape of the twisted pattern appearing on the outer circumference of the wire rope a, and when the collet 3 is tightened, the engaging groove 9 matches the outer shape of the twisted pattern on the outer circumference of the wire rope a. The wire rope a is securely prevented from slipping.

The wire clamp device constructed as described above may be used alone or as a component of a hoisting device using a wire rope, and in any case, the substrate of one end of the cylinder tube 1 is used. 4a is fixed to the installation place by bolting, and further, both the tightening side and return side port ports 10a, 10 of the cylinder 1
Each b is connected to a hydraulic source (not shown). 1 and 5 show an example in which the wire clamp device A is installed upright on the pedestal B and the wire rope a to be clamped is vertically inserted into the wire clamp device A. The case where the wire rope a is pulled downward by the load is shown.

The wire rope a is inserted into the collet 3 with the collet 3 opened, and then the clamp 3 is tightened to clamp the wire rope a.

Therefore, in the wire clamp device described above, when hydraulic pressure is applied from the tightening port port 10a,
The piston 2a of the piston rod 2 moves toward the large diameter side of the collet 3 by the hydraulic pressure on the one end side of the cylinder chamber 1c,
The inner diameter of the fitting portion of the conical tapered surface 2b formed on the inner circumference of the piston rod 2 shifts toward the smaller diameter side. As a result, the collet 3 is compressed from the outer periphery and each unit collet 3'contracts, and the wire rope a inserted into the collet 3 is tightened to be in a clamped state.

In the clamped state, the engaging groove 9 formed on the inner peripheral surface of each unit collet 3'matches the outer shape of the twist pattern formed on the outer circumference of the wire rope a inserted into the collet 3, and as described above. Tightening without slip is performed.

On the contrary, when the piston rod 2 moves toward the small diameter side of the collet 3 by the hydraulic pressure applied from the return side port 10b to the return side in the cylinder chamber 1c, the conical taper surface 2b of the inner circumference of the piston rod 2 is fitted. The inner diameter of the joint portion shifts toward the large diameter side, and each unit collet 3'expands, and the tightening of the wire rope a performed by the collet 3 is released.

When locking the wire rope a in a clamped state, as described above, the tightening port port 1
From the state in which hydraulic pressure is applied from 0a, the lock nut 16 screwed into the projecting portion 2c of the piston rod 2 is rotated to abut against the end surface of the cylinder tube 1, and a tightening tool is inserted into the insertion hole 16a and tightened. Then, as described above, the lock nut 16 comes into contact with the end surface of the cylinder tube 2, whereby the movement of the piston rod 2 and the conical taper surface 2b, which are integrated with the lock nut 16, toward the small diameter side is regulated, whereby the above The collet 3 fitted and inserted in the inner circumference of the conical taper surface 2b is mechanically locked while the wire rope is being tightened.

In the locked state as described above, mechanical locking is performed by the lock nut 16 simultaneously with tightening by hydraulic pressure. Therefore, even if the hydraulic pressure applied to the tightening boat port 10a decreases and the tightening by the hydraulic pressure is released, the piston rod 1 is supported by the lock nut 16 to maintain the tightened state and prevent the clamp from loosening. The safety of is secured.

When the lock nut 16 is unlocked, the hydraulic pressure applied to the tightening port 10a is increased to move the piston rod 2 in the tightening direction until the lock nut 16 is slightly lifted from the end surface of the cylinder tube 1. Just turn it back to the end of the protrusion.

By the way, when the piston rod 2 reciprocates in the axial direction as described above, the collet 3 which is inserted into the conical tapered surface 2b of the piston rod 2 in a fitted state has a conical tapered surface. With the transition of 2b, the piston rod 2 is simply expanded and contracted in the radial direction while keeping the axial center of the piston rod 2 aligned. Therefore, the axial center of the collet 3 does not shift in the radial direction, and the positional relationship between the collet 3 and the wire rope a does not change.

Thus, even if the tightening and releasing by the collet 3 is repeated, the outer shape of the twisted pattern on the outer circumference of the wire rope a and the engagement groove 9 formed on the inner circumference of each unit collet 3'can be always matched. This makes it possible to reliably prevent the wire rope a pulled downward from slipping.

Further, during clamping, the tightening force obtained through the collet 3 increases or decreases in inverse proportion to the inclination angle Θ of the conical tapered surface 2b, and at that time, the collet 3
The reaction force applied from the piston rod 2 is increased or decreased in proportion to the tilt angle Θ. Therefore, by setting the inclination angle Θ of the conical taper surface 2b to be sufficiently small, the tightening force of the collet obtained from a constant hydraulic pressure can be increased, and conversely, the piston rod 2 can be inserted through the collet 3. The reaction force that acts to return the is reduced, and the damage to the jack can be reduced.

Further, the wire rope a inserted through the collet 3 is pulled toward the small diameter direction of the conical taper surface 2b by the downward pulling load, but once the pulling load is applied to the wire rope a, the load is reduced. Since the collet 3 in the clamped state acts like a wedge on the small diameter side of the conical tapered surface 2, the tightening force by the collet 3 is rational in proportion to the increase in the tensile load applied to the wire rope a. Be strengthened.

As described above, the conical tapered surface 2b and the collet 3 have a wedge-shaped tightening effect, so that the tightening force is extremely strong and increases with a high load. .

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a wire clamp device embodying the present invention.

FIG. 2 is a sectional view taken along line XX in FIG.

3 is a sectional view taken along line YY in FIG.

FIG. 4 is a vertical cross-sectional view of a collet.

FIG. 5 is a vertical sectional view showing the wire clamp device in a state where the collet is expanded.

6 is a sectional view taken along line ZZ in FIG.

[Explanation of symbols]

 A ... Wire clamp device a ... Wire rope 1 ... Cylinder tube 2 ... Piston rod 2b ... Conical taper surface 2c ... Projection part 3 ... Clamp 3 '... Unit Clamp 16 ・ ・ ・ Lock nut

Claims (1)

[Scope of utility model registration request] 1. A hollow piston rod that reciprocates hydraulically is inserted into a cylinder tube, and a conical taper surface is formed on the inner circumference of the piston rod, and a conical taper surface is formed in the piston rod. In addition, a truncated cone-shaped collet that can be expanded and contracted in the radial direction by being divided into a plurality of unit collets is inserted, and the outer circumference of the twist pattern formed on the outer circumference of the wire rope on the inner peripheral surface of each unit collet of this collet. A wire clamp in which the end of the piston rod on the large diameter end side of the piston rod is extended and protruded from the cylinder tube while the matching engagement groove is formed, and a lock nut is screwed to the outside of the protrusion of the piston rod. apparatus.