JPS6056839A - Work fixing system - Google Patents

Abstract

PURPOSE:To increase the holding force while to improve the fixing accuracy, in a fixing system associated with self-lock mechanism, by providing a brake sec- tion functioning against the inner wall of cylinder at the end of cylinder head while constituting such that the brake section will function at the finish position of locking function. CONSTITUTION:Cylinder piston 13 is reciprocated together with a tapered rod 14 in the arrow direction (A) by supply air 27 while a supporting spring 23 will contact against the collet section 20 to reciprocate the cylinder head 16 integral with the collet section 20 through a spring 25. Consequently, the cylinder head 16 will collide against a work 2 and stop. Here, the tapered rod 14 will advance further than an idler 18 to push a ball 28 to the outside through the tapered face 17 thus to enlarge the collet section 20 toward the inner wall of cylinder casing 12. As a result, the cylinder head 16 is locked to the cylinder casing 12. With such structure, it can be fixed at random position with high accuracy irrespective of the size of work.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fixing device used for fixing workpieces, in particular to a pneumatic cylinder with a built-in self-locking mechanism.

BACKGROUND ART AND PROBLEMS In manufacturing equipment, jigs, etc., pneumatic cylinders are often used as means for fixing workpieces at arbitrary positions. Conventionally, as a fixing device using a pneumatic cylinder, for example, as shown in Fig. 1, a workpiece (2) is positioned with an abutting cylinder (1), and a locking cylinder (1) is used to position the workpiece (2).
3) is known in which the position of the rod (cylinder head) (la) of the abutting cylinder (1) is locked (fixed). However, in the case of this fixing device, in the locked state, the rod (1a
) has a weak holding force to hold the cylinder ( There are drawbacks such as a long operating time required to operate 1) and (3).

On the other hand, a pneumatic cylinder with a built-in mechanism that locks the rod of the cylinder directly with hydraulic pressure or spring pressure has been proposed, but this pneumatic cylinder requires separate energy to lock or release the rod. Alternatively, there are drawbacks such as the need to apply a signal from the outside upon release, and furthermore, there is a limit to the holding force.

Purpose of the Invention In view of the above points, the present invention has a simple structure, can obtain a large holding force with low air pressure, and can be fixed at any position with lai accuracy regardless of variations in the size of the workpiece. The present invention provides a workpiece fixing device using a pneumatic cylinder with a built-in self-locking mechanism.

4. Existing Summary of the Invention The present invention has a cylinder head that integrally has a brake part that comes into sliding contact with the inner wall of the cylinder and comes into contact with the workpiece, and a cylinder piston that moves reciprocally and has an integral taber "toad". :1 The free end of the rod is connected to the cylinder inner wall 1-' with a play 5G, and the cylinder head is made to move forward through a spring interposed between the cylinder head and the taber rod.Then, the taber rod A ball is interposed between the brake part and the brake part, and when the Taber rod moves forward, the brake part comes into pressure contact with the inner wall of the cylinder via the ball, thereby fixing the position of the cylinder head.

This fixing device makes contact with the workpiece with low air pressure and provides a large holding force when locked.

In addition, workpieces with varying sizes can be fixed with high viscosity at arbitrary positions.

Embodiment Hereinafter, one embodiment of the workpiece fixing device according to the present invention will be described with reference to FIGS. 2 and 3.

In FIGS. 2 and 3, (2) indicates the workpiece to be fixed, and (11) indicates the entire fixing device according to the present invention. This fixing device (11) includes a cylinder piston (13) that reciprocates within a cylinder casing (12), and a Taber rod (14) that is integrated with the cylinder piston (13).
) and a cylinder head (
16) is incorporated.

The cylinder head (16) has a cylindrical part (16A) that slides on the cylinder inner wall (12a), and a brake part (15) is integrally provided so as to extend from this cylindrical part (16). The cylinder head (1) comes into contact with the workpiece (2).
6) is led out through the cylinder housing (12). The tapered rod (14) has a tapered portion (17) whose outer diameter gradually decreases in the forward movement direction (in direction of the arrow), and its free end (17a) is connected to the cylindrical portion (16) of the cylinder head (16).
16A) with some play. For this connection, a large diameter hole (18) is formed on the cylindrical portion (16Δ) side, and the taber rod free end (17a) is inserted into this hole (18).
) is engaged with the pin (19) provided at the top. In this case, the outer diameter d of the pin (19) and the inner diameter of the hole (18) are d
<Selected for relationship D.

On the other hand, the brake part (15) includes a cylinder head (16)
It is composed of a thin collet part (so-called cylindrical part) (20) that extends with the same outer diameter as the cylindrical part (16A) and is divided into three parts in the circumferential direction. This collet 01 ((
20) has a tapered part (20) on the inner surface facing the tapered part (17) of the taper rod (14) in the same direction as the tapered part (17).
21) is formed so that it can be pushed and expanded toward the cylinder inner wall (12a) by a ball bearing (22), which will be described later. The Taper angles of both the Taper parts (17) and (21) are selected to be the optimum angle in relation to the magnitude of the locking force and the magnitude of the unlocking force.
For example, it is selected to be about 4゛. The taper portion (21) of the collet portion (20) and the taper portion (
17) A ball bearing (22) is interposed between them.

This ball bearing (22) and taper rod (]4)
A pair of support rings (23) and (24) arranged to surround the
), the first spring (25) is interposed between one support ring (23) and the cylinder piston (13), the other support ring (24) and the cylinder head cylindrical part (16A ) is interposed between the second spring (
26). The peripheral edge of one of the support rings (23) is in contact with the end surface of the collet part (20), and when the cylinder piston (13) moves forward, the collet part (20) is connected via the first spring (25). ), and the cylinder head (16) integrated therewith is configured to be moved forward. The spring pressure of the springs (25) and (26) is greater than the sliding resistance between the collet part (20) and the cylindrical part (168) and the cylinder inner wall (12a), and the force does not move the workpiece (2). set smaller. Note that (27) and (28) are air supply holes provided in the cylinder casing (12a).

Next, the operation of this fixing device i\(11) will be explained.

When compressed air is supplied from the air supply hole (27) in the original position i of FIG. 2, the cylinder piston (13) moves forward in the direction of the arrow along with the Taber rod (14).

At the same time, since the support ring (23) is in contact with the collet part (20), the cylinder head (16) integrated with the collet part (20) also moves forward via the first spring (25).

When the cylinder head (16) comes into contact with the workpiece (2) (see Figure 3), the weight of the first spring (25) is applied to the workpiece (2) without moving it. Due to the weaker setting, the cylinder head (16)
i! 7 in j1! ;(Stop.On the other hand, the cylinder head (1
6) and the cable shaft (14) are connected with play, so the cylinder head (16) is connected to the workpiece (2).
) (for you too, the taper rod (14) moves forward further.Then, when the bottle (19) does not come into contact with the front edge of the hole (18), the tip i<+ rod (1
The taper part (17) of 4) enters and the hall bearing (
28) is pushed, and the C collet portion (20) is pushed and expanded by this ball bearing (28). As a result,
As shown in FIG. 2, the outer circumferential surface of the col/reverse part (20) comes into pressure contact with the cylinder inner wall (12a), applying a so-called brake, and locking the position of the cylinder head (16).

Next, when the solenoid valve is switched and compressed air is supplied from the air supply hole (28), the cylinder piston (13) moves back in the direction of arrow 13, and the taper part (17) of the taper rod (14) retreats, causing the collet part (20) returns to its normal state, and the cylinder head (16) is unlocked. At the same time, the bottle (I9) comes into contact with the rear edge of the hole (18) due to the return movement of the taber lower t' (14), and the bottle (I9) comes into contact with the rear edge of the hole (18).
19), the cylinder head (16) returns to its original position as shown in FIG.

In this configuration, the collet part (2(1)) is pushed apart by the entry of the taber rod (14) and the cylinder head (16) is held I:I, so the holding force of the cylinder head (16) is large in the locked state. Become.

That is, since the ball hair ring <2+3> is interposed between the taper part (21) of the collet part (20) and the taper part (17) of the taper rod (14), a so-called wedge effect is produced when the taper rod (14) enters. arise.

This wedge effect increases the force and the cylinder piston (13
) The direction of the force is the direction that strengthens the lock, so a large holding force can be obtained with low air pressure.

Then, the cylinder head (16) and Taber rod (14)
) are connected with some play, so after the cylinder head (16) comes into contact with the workpiece (2), only the Taber rod (14) moves independently of the cylinder head (16). lock. Therefore, the workpiece (2) can be fixed at any position with surface accuracy regardless of variations in the size of the workpiece (2). At the same time, excessive force is not applied to the workpiece (2) during locking, so there is no risk of deforming the workpiece (2).

In addition, since the spring pressure of the springs (25) and (26) is set to be weaker than the force without moving the workpiece (2), when the cylinder head (16) comes into contact with the workpiece (2), This never fails. Further, since the built-in self-locking mechanism is operated by compressed air without moving the cylinder piston (13), there is no delay in the operation of the locking mechanism. Further, no separate energy or actuator is required for locking or unlocking, and no external signal is required. The overall structure is therefore simplified and miniaturized.

Although the IIJ locking mechanism is integrally disposed within the common cylinder housing on the two sides, it is also possible to construct the cylinder piston separately, for example, in a separate cylinder housing.

Effects of the Invention As described above, according to the present invention, the fixing device itself automatically determines the optimum stroke of the cylinder head depending on the workpiece, and the cylinder head can be strongly locked at that position. In particular, the Taber rod is integrally formed with the cylinder piston, and the brake part that slides on the cylinder inner wall is provided integrally with the cylinder head, and when the Taber rod moves forward, the brake part is pressed against the cylinder inner wall via the ball, so the lock is secured. As for the holding force of the cylinder head in this condition, a larger holding force can be obtained with lower air pressure.

Further, since the taber rod and the cylinder head are connected with some play, excessive force is not applied to the workpiece during locking, and the workpiece is not deformed. In addition, the workpiece can be fixed with surface precision regardless of variations in the size of the workpiece. Further, since the cylinder body and the so-called self-locking mechanism are integrated, the structure of the entire device is simplified and downsized.

[Brief explanation of the drawing]

FIG. 1 is a front view of an example of a conventional fixing device, FIG. 2 is a sectional view showing an embodiment of the fixing device of the present invention, and FIG. 3 is a side view for explaining its operation. (2) is the workpiece, (12) is the cylinder casing, (13)
is the cylinder piston, (14) is the Taber rod, (15
) is the brake part, (16) is the cylinder head, (25)
, C26) is a spring, and (28) is a ball hair ring. Figure 2 Figure 3

Claims (1)

[Claims] A cylinder head that has an integrated brake part that slides on the inner wall of the cylinder and that comes into contact with the workpiece, and a reciprocating cylinder piston that has an integrated taber rod, and the free end of the taber rod has play in the cylinder head. A ball is interposed between the Taber rod and the brake part, and the cylinder head is moved forward via a spring interposed between the cylinder head and the Taber rod, and when the Taber rod moves forward, the cylinder head is moved forward through the ball. A device for fixing a workpiece, wherein the brake portion presses against the inner wall of the cylinder to fix the position of the cylinder head.