JPH0885Y2 - Tail sleeve locking mechanism - Google Patents

Description

TECHNICAL FIELD The present invention relates to a tailstock sleeve of a tailstock used for a lathe, etc. More specifically, when the hydraulic pressure stops acting on the drive piston, the drive piston is mechanically operated. Lock it,
The present invention relates to a locking mechanism for a tailstock sleeve that prevents a work piece from falling.

(B) Conventional Technique FIG. 2 shows an operation mechanism of a tailstock sleeve of a tailstock that is generally used in the past.

In the figure, the steel ball 17 in the block 16 is biased by a spring 18 and acts as a check valve. The top 19 can be slid to the left and right by hydraulic pressure.

When the solenoid valve SOL is turned off, oil enters the block 16 from A, pushes away the steel ball 17, flows out from B, and flows into the C chamber of the cylinder 3. The hydraulic pressure causes the piston 5 to move forward, and the tailstock sleeve 6 integrally connected to the piston 5 also moves forward. And cylinder 3
Oil flows out of the D chamber, and returns to the oil tank T through E and F of the block 16.

When the solenoid valve SOL is turned ON, oil will block 16
Through F and E, and flows into the D chamber of the cylinder 3. At this time, in the block 16, the top 19 moves to the steel ball 17 side by hydraulic pressure, its tip hits the steel ball 17, and the steel ball 17 presses the spring 22 and moves to the right (points to the right in the same figure). .

Then, the piston 5 and the tailstock sleeve 6 are retracted by the oil flowing into the D chamber of the cylinder 3. At this time, oil flows out from the chamber C of the cylinder 3 and enters the block 16 from B, but since the steel ball 17 is moving to the right, the oil reaches A and returns to the oil tank T.

With the above-described structure and operation, the tailstock sleeve 6
To move the workpiece forward and backward, and thereby the work (not shown)
It was designed to be pressed and held and released.

(C) Problems to be solved by the invention As described above, the tailstock sleeve is moved forward by hydraulic pressure.
In a tailstock such as a lathe to be retracted, in order to press and hold a work at the center of the tailstock, hydraulic pressure must be applied so that the tailing sleeve always keeps the advanced state. However, if the pressure is weakened or interrupted due to some reason, the pressure holding force of the tailstock sleeve is lost, and the tailpiece sleeve moves backward due to the self-weight of the work, and the work may fall. It happens.

Further, in such a tailing sleeve drive mechanism,
When the tailstock sleeve moves forward and the hydraulic pressure stops working while pressing and holding the work, the steel ball does not move because the top does not operate even when trying to retract the tailstock sleeve, so the oil moves from B of the block. The hydraulic pressure is held between B and C without flowing to A, and the tailstock sleeve is locked.

Strictly speaking, however, oil seeps out from the minute gap between the contact surface of the steel ball and the block, so that the tailing sleeve gradually retracts, and the work may drop after a long time.

D. Means for Solving the Problems The present invention has been made in view of the circumstances of the above-mentioned prior art, and as a solution thereof, when the hydraulic pressure stops acting on the drive piston integrally connected with the tailstock sleeve, the tailstock sleeve is provided. Mechanically locks the drive piston to prevent
(EN) A locking mechanism for a tailstock sleeve that prevents a work piece from dropping. The structure is the same as that of the tailstock sleeve drive mechanism in which the drive piston of the oil pressure cylinder moves forward and backward. A sub-cylinder chamber is provided in the sub-cylinder chamber, and a flange with a taper hole into which the rod of the drive piston is loosely fitted is provided in the sub-cylinder chamber. A collet having a split taper portion, an elastic member that urges the taper portion of the collet into close contact with the tapered hole, and a floating piston that pushes back the collet by hydraulic pressure against the urging force of the elastic member. And a pipe for supplying the hydraulic pressure to the sub-cylinder chamber is connected.

E action When the hydraulic pump is operating, the tailing sleeve moves forward to hold the work by the drive piston of the hydraulic cylinder, and the hydraulic pressure is supplied to the sub cylinder chamber by the pipe and floats by the hydraulic pressure. The piston is pushed to the flange side, contacts the flange and stops. At the same time, the floating piston pushes the collet back against the urging force of the elastic member, so that the tapered portion of the collet is kept out of contact with the tapered hole of the flange.

In this state, if the hydraulic pressure stops working due to power interruption or the like, the hydraulic pressure in the sub-cylinder chamber also stops working, so that the collet pushes the floating piston back by the biasing force of the elastic member and contacts the tapered hole of the flange. By this contact, a force is exerted on the collet toward the axial center of the tailstock sleeve, and the collet is elastically deformed to grip the drive piston and fix it in the axial direction of the tailstock sleeve. Therefore, the tailstock sleeve is fixed in the axial direction with respect to the tailstock, so that the tailstock sleeve presses and holds the workpiece to prevent its fall regardless of the hydraulic pressure of the hydraulic cylinder.

F. Embodiment An embodiment of the locking mechanism for the tailstock sleeve according to the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a tailstock to which a flange 2, a cylinder 3 and a cylinder cover 4 are fastened and fixed by screws (not shown). A drive piston 5 is inserted into the cylinder 3 so as to be capable of reciprocating in the axial direction of the tailstock sleeve 6, and the drive piston 5 has a flange 7
In addition to being screwed in, the set screw 8 prevents the screw portion of the drive piston 5 from loosening. Since the flange 7 is screwed to the rear end surface of the tailing sleeve 6, the tailing sleeve 6 and the flange 7 are integrally connected to the drive piston 5, so that the tailing sleeve 6 operates in conjunction with the drive piston 5. To do.

The flange 2 and the concave portion of the cylinder 3 that is in contact with the flange 2 form a sub-cylinder chamber 9 that is coaxial with the hydraulic cylinder 3. A taper hole into which the rod 5a of the drive piston 5 is loosely fitted is provided in the sub cylinder chamber 9.
A flange 10 provided with a small diameter portion 10a is fastened to the cylinder 3 with a set screw 10b. In addition, the sub-cylinder chamber 9
Inside, the outer peripheral taper portion 1 is slidably fitted to the rod 5a and has a slit-like shape similar to the tapered hole 10a of the flange 10.
Collet 11 having 1a and tapered portion of the collet 11
A disc spring 12 as an elastic member for urging and tightly adhering 11a to the taper hole 10a and a floating piston 13 slidably fitted in the flange 2 and slidably fitted in the rod 5a are provided. There is. Further, the sub cylinder chamber 9 is connected with a pipe 14 for directly supplying hydraulic oil from the pump P to the sub cylinder chamber 9.

Further, to the piston head side chamber 3a and the piston rod side chamber 3b of the cylinder 3, oil valves 15a and 15b communicating with the solenoid valve SOL, the hydraulic pump P and the oil tank T are connected, respectively.

The locking mechanism of the tailing sleeve configured as described above operates as follows.

That is, when the solenoid valve SOL is turned off, the oil tank T
The hydraulic oil sent from the hydraulic pump P from the oil pipe 15a
Through the piston head side chamber 3a, the hydraulic pressure causes the drive piston 5 to move forward, and the flange 7 and the tailstock sleeve 6 that are integrally connected to the drive piston 5 advance in conjunction with the center 6a at the tip of the tailstock sleeve 6. A work (not shown) is pressed and held.

Further, when the solenoid valve SOL is switched to ON, hydraulic oil enters the piston rod side chamber 3b through the oil pipe 15a, the hydraulic pressure thereof causes the drive piston 5 to retract, and the flange 7 and tailstock sleeve 6 that are integrally connected thereto. Moves backward in conjunction with each other, and the pressure holding of the center 6a against the work is released.

At the same time, the hydraulic oil in the piston head side chamber 3a is pushed by the drive piston 5 and returns to the oil tank T via the oil pipe 15a and the solenoid valve SOL.

Normally, since hydraulic pressure is constantly acting, hydraulic oil enters the sub cylinder chamber 9 from the hydraulic pump P through the pipe 14 and
The hydraulic pressure pushes the floating piston 13 toward the flange 10 side, contacts the flange 10 and stops. At the same time, the floating piston 13 pushes the collet 11 back to the cylinder 3 side against the urging force of the disc spring 12, so that the taper portion 11 of the collet 11 is pressed.
a maintains a non-contact state with the tapered hole 10a of the flange 10.

However, as described above, when the solenoid valve SOL is turned off, the drive piston 5 moves forward, and the tailstock sleeve 6a presses and holds the workpiece, if the hydraulic pressure stops due to power interruption or the like, the sub cylinder Since the hydraulic pressure in the chamber 9 also does not act, the collet 11 pushes back the floating piston 13 by the urging force of the disc spring 12 and also the taper portion thereof.
11a contacts the tapered hole 10a of the flange 10. Due to this contact, a force is exerted on the collet 11 toward the axial center of the tailstock sleeve 6, and the collet 11 is elastically deformed and the drive piston 5 is moved.
Then, the drive piston 5 is fixed in the axial direction of the tailstock sleeve 6 by gripping the rod 5a. Therefore, since the tailstock sleeve 6 is axially fixed to the tailstock 1, the tailstock sleeve 6 reliably and long-terms the work regardless of the hydraulic pressure of the piston head side chamber 3a of the hydraulic cylinder 3. It is possible to prevent the work from dropping even if there is oil leakage in the hydraulic cylinder 3 by pressing and holding it.

In order to release the fixation of the drive piston 5 by the collet 11, the hydraulic oil is sent to the sub cylinder chamber 9 again, and the fixation of the drive piston 5 is released by the action opposite to the above.

In addition, the flange 10 and collet 1 provided in the sub cylinder chamber 9
1, the disc spring 12 and the floating piston 13 and the pipe 14 connected to the auxiliary cylinder chamber 9 may be arranged in the opposite arrangement and direction from the above embodiment, or the driving piston may be provided outside the piston head side chamber. It is also possible to provide an extending rod, provide the sub cylinder chamber as described above in the rod portion, and provide the collet 11 and other related parts in the sub cylinder chamber.

Further, in the above embodiment, hydraulic pressure is used as the driving force,
Pneumatic pressure can be used instead of hydraulic pressure.

As described above, the locking mechanism for the tailing sleeve according to the present invention is provided with a sub-cylinder chamber coaxially with the hydraulic cylinder, and in the sub-cylinder chamber, a flange with a tapered hole and the taper thereof are provided. Provided with a collet having a tapered portion similar to the hole and having a slitting shape, an elastic member for urging the collet, and a floating piston for pushing back the collet by hydraulic pressure against the urging force of the elastic member. Therefore, while the work piece is being pressed and held by the tailstock sleeve, even if the hydraulic pressure does not act on the drive piston, the tailstock sleeve integrally connected to the drive piston is not retracted mechanically. Since it locks, it can maintain its fixing force for a long time regardless of oil leakage from the cylinder, etc., and it is possible to reliably prevent the work from falling, which is an extremely important factor in work safety. Te is beneficial.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view of an essential part of an embodiment of the present invention, and FIG. 2 is an operation mechanism diagram of a conventional tailstock sleeve. 1 ... tailstock, 2 ... flange, 3 ... cylinder, 3a
...... Piston head side chamber, 3b ...... Piston rod side chamber,
4 ... Cylinder cover, 5 ... Drive piston, 5a ... Rod, 6 ... Sleeve, 6a ... Center, 7 ... Flange, 8 ... Set screw, 9 ... Sub-cylinder chamber, 10 ... Flange, 10a ... Tapered hole, 10b ... Set screw, 11 ... Collet, 11a ... Tapered part, 12 ... Disc spring, 13 ... Floating piston, 14 ... Pipe, 15a, 15b ... Oil pipe, 16 ...
Block, 17 …… Steel ball, 18 …… Spring, 19 …… Top, P…
… Pump, T… Oil tank, SOL… Solenoid valve.

Claims (1)

[Scope of utility model registration request] 1. A drive mechanism for a tailstock sleeve in which a drive piston of an oil pressure cylinder moves forward and backward, a sub cylinder chamber is provided coaxially with the oil pressure cylinder, and the drive piston of the drive piston is provided in the sub cylinder chamber. With a flange with a tapered hole where the rod fits loosely,
A collet slidably fitted on the rod and having a tapered portion similar in shape to the tapered hole and having a slitting shape, and an elastic member for urging the tapered portion of the collet into close contact with the tapered hole, A locking mechanism for a tailing sleeve, comprising: a floating piston that pushes back the collet by hydraulic pressure against an urging force of an elastic member, and further connects a pipe that supplies the hydraulic pressure to the sub-cylinder chamber. .