JP3130952B2 - Free lock mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a free lock mechanism for fixing and releasing a slide of a telescopic rod at an arbitrary position.

[0002]

2. Description of the Related Art As a conventional free lock mechanism, Japanese Unexamined Utility Model Publication No. 63-25809 discloses a groove formed in a rod which is slidably inserted into an outer cylinder, and a ball held by the outer cylinder is applied to the groove. There is disclosed a free lock mechanism in which the movement of the rod is stopped by pushing the ball from the outside of the outer cylinder, or the rod is released by releasing the ball.

However, in this case, the lock cannot be released remotely, whereas the one disclosed in Japanese Patent Application Laid-Open No. Sho 62-237108 has a structure in which the lock is released by hydraulic pressure or the like. Thereby, the movement of the rod can be remotely controlled.

[0004]

However, in this device, since the lock is released using hydraulic pressure or the like, the mechanism is complicated, and the size of the device is unavoidable. There was a problem in terms of cost.

An object of the present invention is to provide a free lock mechanism which can be remotely operated, has a simple structure, and operates reliably.

[0006]

Accordingly, the present invention provides an outer cylinder
Rod freely inserted into the rod and formed around the rod
Locking groove and a cylindrical shape outside the rod,
And the guide held in the guide hole of this guide
Ball or pin with ball or pin facing locking groove
Lock sleeve with a cam surface
Return spring that urges sleeve to locking position
And the lock sleeve against this return spring
And a solenoid that moves to the release position.
Insert a rod through the inner periphery of the bobbin,
Mount the leave coaxially with the rod, and use the solenoid
Move lock sleeve to select ball or pin
In the free lock mechanism that locks in the locking groove, the guide
Place a ring-shaped leaf spring on the inner circumference of the
Lock the ball or pin with the spring
While biasing toward the inner circumference of the cam surface of the
Shape a retaining hole through which part of the ball or pin passes.
Done.

[0007]

When the solenoid is not energized, the lock sleeve is returned by the return spring and the ball or pin is pushed into the locking groove to lock the rod. When the solenoid is energized, the lock sleeve is pulled, the ball or pin is released, and the rod is free to move. Ma
In addition, the leaf spring is
Press the tool or pin against the cam surface of the lock sleeve from inside.
Press to ensure that the ball or pin is unlocked from the locking groove
To do.

[0008]

1 and 2 show a first embodiment, in which a rod 2 is slidably inserted into a cylinder (outer cylinder) 1. FIG. The rod 2 is a bearing 3 fixed to the end of the cylinder 1
Then, the bobbin 5 of the solenoid 4 fixed to the bearing 3 is slidably penetrated. The bearing 3 is fixed to the end of the cylinder 1 by caulking, the extended end of the cover 6 of the solenoid 4 is fitted to the bearing 3, and the fitted portion is fixed to the bearing 3 by caulking.

A plurality of locking grooves 7 are formed in the outer periphery of the intermediate portion of the rod 2 in the axial direction. A pair of balls 8 selectively fitted into the locking grooves 7 It is held by a pair of guide holes 11 formed in a cylindrical guide 10 extending along the outer periphery. The depth of the guide hole 11 is smaller than the diameter of the ball 8, and a part of the ball 8 is
Get out of

A lock sleeve 12 is slidably fitted to the outside of the guide 10, and the lock sleeve 12
Is formed with a stepped cam surface 13 for pressing or releasing the ball 8. A seat 14 for adsorbing the lock sleeve 12 is provided at an end of the solenoid 4, and is fixed to a fitting portion 16 formed on the bobbin 5. Further, a return spring 15 for urging the lock sleeve 12 to the lock position is interposed between the return spring 15 and the end surface of the bobbin 5.

The rod 2, bobbin 5, cover 6, lock sleeve 12, and seat portion 14 are made of a magnetic material.
The guide 10 is made of a non-magnetic material. Therefore, when the solenoid 4 is excited, the lock sleeve 12 normally pressed by the return spring 15 moves against the spring force and is attracted to the seat portion 14.

As shown in FIG. 2, a leaf spring 17 is mounted on the inner periphery of the guide 10 so as to press and float the ball 8 inserted into the guide hole 11 of the guide 10 from the inside. . A retaining hole 18 smaller than the diameter of the ball 8 is formed in the leaf spring 17 formed in a ring shape in accordance with the position of the ball 8.
Is partially fitted.

At the ends of the rod 2 and the cylinder 1, mounting brackets 19 and 20 each having a rubber cushion 21 are provided.

The operation will be described next. Now, when power is supplied to the solenoid 4, the rod 2,
The bobbin 5, the cover 6, the seat portion 14, and the lock sleeve 12 are magnetized, and the lock sleeve 12 is attracted to the seat portion 14 against the return spring 15 (the lower cross section in FIG. 1 shows this state).

For this reason, the large-diameter cam surface 13 of the lock sleeve 12 comes to the position of the ball 8 and the guide hole 1 of the guide 10
The ball 8 guided by 1 is pushed up radially by the leaf spring 17 until it comes into contact with the large-diameter cam surface 13. As a result, the ball 8 comes off from the locking groove 7 of the rod 2, the lock is released, and the rod 2 enters a free state in which it can slide freely along the cylinder 1.

On the other hand, when the power supply to the solenoid 4 is stopped, the lock sleeve 12 is pushed back by the return spring 15 (the upper cross section in FIG. 1 shows this state).

For this reason, the ball 8 is pushed along the guide hole 11 by the small-diameter cam surface 13 of the lock sleeve 12 and a part thereof is locked in the locking groove 7 of the rod 2 to fix the movement of the rod 2. .

In this manner, the movement of the rod 2 can be restrained or released by turning on and off the exciting current to the solenoid 4. When the rod 2 is locked, the stroke position of the rod 2 is determined by the position of the locking groove 7 into which the ball 8 fits.

Since the mounting brackets 19 and 20 at the ends of the rod 2 and the cylinder 1 are provided with rubber cushions, the shock when the rod 2 is locked while moving can be reduced.

Next, another embodiment will be described.

In the embodiment shown in FIG. 3, the lock sleeve 12 is
It comprises a sleeve portion 12A having a cam surface 13 and a disk portion 12B which comes into contact with the return spring 15. In order to reduce the axial length of the lock mechanism, the return spring 15 is connected to the solenoid 4 The bobbin 5 is in contact with the opposite end face.

The mounting brackets 19 and 20 are formed in a circular shape, and a collar 22 is provided at the center of the rubber cushion 21.
Is fitted.

Incidentally, the lock sleeve 12 can be constituted by a disk portion 12B partially fitted into the sleeve portion 12A as in the embodiment of FIG.

In the embodiment shown in FIG. 5, the solenoid 4 is disposed on the cylinder 1 side and the lock mechanism is disposed on the outside, and the bearing 3 of the cylinder 1 is constituted by a flange 3A.

Further, in the embodiment shown in FIG. 6, a pin 23 is used instead of the ball 8 to lock the rod 2, and the guide 10
Is inserted into the guide hole 11 of the first embodiment.

Also in this case, the pin 23 is fitted in the locking groove 7 of the rod 2 like the ball 8, and the movement of the rod 2 can be restrained.

FIGS. 7 and 8 show another example of the pin 23. FIG.
FIG. 7 shows two balls 25, 26 inside a cylindrical member 24.
Are arranged so that the end portions of the respective balls come into contact with the cam surface 13 and the locking grooves 7, respectively, thereby improving the smoothness of operation.

In FIG. 8, large and small balls 28, 29 are embedded at both ends of the pin member 27, and the smooth operation is also ensured.

According to the present invention, the inside of the cylinder 1 may be constituted by a hydraulic damper, and may be constituted as a free lock mechanism for fixing the movement of the piston rod as required. As a hydraulic damper for this purpose, for example, Japanese Utility Model Application No. 2-84198 can be used. In this case, the locking groove 7 formed in the rod 2 may be provided at one position. Of course, a plurality can be provided as necessary, but in any case, it is necessary to set a position where the locking groove 7 does not enter the inside of the damper.

[0030]

As described above, according to the present invention, the leafs
The ball inserted into the guide hole of the guide by pulling
Press the pin against the cam surface of the lock sleeve from inside.
Lock work between ball or pin and locking groove
Since the operation is reliable and stable, and the unlocking operation is performed by controlling the energization of the solenoid, control with good responsiveness is realized, and the overall configuration can be simplified and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

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

FIG. 3 is a sectional view of a second embodiment.

FIG. 4 is a sectional view showing a main part of a third embodiment.

FIG. 5 is a sectional view of a fourth embodiment.

FIG. 6 is a sectional view of a fifth embodiment.

FIG. 7 is a sectional view showing a main part of a sixth embodiment.

FIG. 8 is a sectional view showing a main part of a seventh embodiment.

[Explanation of symbols]

 Reference Signs List 1 cylinder 2 rod 4 solenoid 5 bobbin 7 locking groove 8 ball 10 guide 12 lock sleeve 13 cam surface 14 seat part 15 return spring 17 leaf spring 23 pin

Claims (1)

(57) [Claims] A rod slidably inserted into an outer cylinder;
Locking groove formed on the outer circumference of the rod and cylindrical on the outside of the rod
And a guide fixed to the outer cylinder side
The ball or pin held by the guide hole and the ball or pin
Lox with a cam surface that moves the pin toward the locking groove
And a rib for urging the lock sleeve to the locking position.
Turn spring and against this return spring
Solenoid to move the lock sleeve to the release position
The rod around the inner periphery of the solenoid bobbin
Attach the rod and the rod coaxially to the rod,
Use the solenoid to move the lock sleeve to
Is a free lock mechanism that selectively locks the pin in the locking groove
A ring-shaped leaf spring on the inner circumference of the guide
The ball or pin by the leaf spring.
Biasing the lock sleeve toward the inner circumference of the cam surface of the lock sleeve.
Through the leaf spring and part of the ball or pin
Free lock characterized by forming holding holes
mechanism.