JPS5826762Y2 - Work holding device - Google Patents

Description

[Detailed description of the invention] This invention relates to a device for holding a workpiece with low rigidity.The purpose of the invention is to hold the workpiece without distortion, and to hold the workpiece sufficiently and reliably even during heavy cutting operations involving shocking external forces. The objective is to be able to maintain proper work holding.

Conventionally, when holding a workpiece with low rigidity, the plunger that contacts the workpiece and the taper member that fits into the collet chuck are pushed by a cylinder device via a spring, and in accordance with this pushing, the plunger is moved based on the pressing force of the spring. A natural clamp method is used in which the workpiece is held by pressing the plunger against the workpiece and clamping the plunger with a collet chuck.

According to this, in order not to distort the workpiece when holding the workpiece, it is necessary to set the pushing force of the taper member by the spring to a suitably small value, but if this pushing force is small, the clamping action of the plunger by the collet chuck will be reduced. However, when a large impact force such as cutting resistance is applied during machining of a workpiece, the plunger moves back slightly and the workpiece cannot be held stably.

In addition, in order to prevent the plunger that presses the workpiece from retreating, some devices are equipped with a locking means that presses the wedge body in the radial direction of the plunger, but the engagement surface where the wedge body and the plunger engage is pressed in the radial direction. The angle of inclination to the axis was extremely small in order to prevent the pressure from producing any axial force on the plunger.

For this reason, there has been a drawback that the retreat prevention action of the plunger is insufficient, and when the workpiece vibrates during machining, the workpiece holding position of the plunger changes, causing chatter in the workpiece.

Therefore, it is necessary to be able to hold the workpiece without distorting it, and to ensure stable workpiece holding even when a large external force is applied.

The present invention has been developed in view of the above-mentioned conventional needs, and the wedge body that acts to prevent the plunger from retreating has a large inclination angle with respect to the axis of the plunger to achieve a sufficient effect of preventing the retreating. In order to prevent the workpiece from being distorted even when this wedge body is engaged with the plunger, the plunger is clamped by pressing in the radial direction before locking the wedge, and the wedge body does not apply an axial pressing force greater than this clamping force. In this way, the pressing force of the wedge body is limited.

Embodiments of the present invention will be described below based on the drawings.

First, 1 is a base, and on this base 1 is the main body 2 of the work holding device.
is fixed.

A sleeve 3 is fitted onto the main body 2. A plunger 4 is fixed to the sleeve 3 by a pin 5 and is slidably mounted in the vertical direction. A contactor 6 that comes into contact with the workpiece W that is received by the
are integrally fixed.

A sliding rod 7 supported by a pin 5 is slidably fitted into the plunger 4. A spring 9 is inserted between the sliding rod 7 and a screw 8 screwed onto the plunger 4. The plunger 4 is urged in a direction to bring the contactor 6 into contact with the workpiece W.

Further, at the rear end of the plunger 4, a cutout groove 12 (
(See Figure 4) is engraved.

Further, an engagement groove 14 is formed at the rear end of the plunger 4 and has an engagement surface 13 having a gentler inclination angle than the aforementioned engagement surface 11 in a direction perpendicular to the axis of the plunger 4 .

A support member 20 is integrally fixed to the side of the main body 2, and a movable body 21 is supported by the support member 20 so as to be movable in a direction perpendicular to the direction of movement of the plunger 4.

A through hole 21a is formed in the center of this moving body 21,
A detent member 22 fixed to the support member 20 is fitted into the through hole 21a.

A piston rod 24 of a fluid pressure cylinder device 23 mounted on the support member 20 is connected to the rear end of the movable body 21 .

A support plate 25 is integrally coupled to the distal end of the movable body 21, and an actuation rod 26 is supported on the support plate 25 so as to be relatively movable in the moving direction of the movable body 21. It is urged toward the forward end by an interposed spring 27.

Furthermore, this actuating rod 26 is supported by the main body 2 so as to be slidable only, and an engaging protrusion 27 is formed at the tip thereof with an engaging surface 27a that fits into the notch groove 12 and engages with and disengages from the engaging surface 11.
protrudes in the radial direction.

The locking protrusion 27 is also formed with an inclined surface 27b that engages with and disengages from the inclined surface 10.

Further, a screw member 30 is screwed onto the support plate 25, and a support shaft 31 is fitted into the screw member 30 so as to be spaced apart from each other in the axial direction of the actuating rod 26 and the plunger 4 so as to be movable back and forth in directions parallel to each other. ing.

A regulating member 32 that comes into contact with the screw member 30 to regulate the forward end of the supporting shaft 31 is screwed onto the rear end of the supporting shaft 31, and a wedge member 33 is integrally coupled to the tip.

A spring 34 is inserted between the wedge member 33 and the screw member 30, which has a smaller elastic force than the spring 27 and urges the wedge member 33 toward the forward end.

The wedge member 33 is slidably supported by the main body 2 and engages with the engagement groove 14. An inclined surface 33a that engages with and disengages from the inclined surface 13 is formed at the upper end of the wedge member 33.

Next, the operation of the above configuration will be explained.

First, when holding the workpiece W placed on the worksheet S, the workpiece pressing indicated by the imaginary line is performed by operating the fluid pressure cylinder device 23 with the device P descending and pressing the workpiece W onto the worksheet S. As a result, the movable body 21 is moved forward to the right from the rearward end position shown in FIG.

As a result, the actuating rod 26 and the wedge member 33 are moved forward together with the movable body 21, and the plunger 4 is moved forward by the spring 9.
Due to the elastic force, the tag contactor 6 rises toward the workpiece W and comes into contact with the workpiece W without distorting it.

Following this contact, the engaging surface 27a of the actuating rod 26 separates from the engaging surface 11 of the plunger 4, and then the inclined surfaces 10 and 27b engage with each other as shown in FIG.
7, the plunger 4 is pressed by the actuating rod 26 from a direction perpendicular to its sliding direction, and is clamped against the main body 2.

Thereafter, as the movable body 21 moves further forward, the actuating rod 26 is retracted relative to the movable body 21, as shown in FIG. While engaging with the inclined surface 13 and being pressed by the spring 34, the regulating member 32 is separated from the screw member 30.

In this way, the plunger 4 is firmly wedge-locked by the wedge member 33.

When the moving body 21 reaches the forward end as shown in FIG. 2 and the holding operation of the workpiece W is completed, the workpiece W is clamped to the worksheet S and the plunger 4 by an unillustrated clamping device, and then the workpiece In the pressing process, the upper surface of the workpiece W is cut after the device P is raised.

Even if cutting resistance acts in the direction of retreating the plunger 4 from the workpiece W during this machining, the plunger 4 is pressed and clamped in the radial direction by the actuating rod 26 and wedge-locked in the axial direction by the wedge member 33. Therefore, the plunger 4 never retreats from the workpiece W, the workpiece holding position of the plunger 4 can be reliably maintained, and distortion or chatter of the workpiece W is completely prevented.

When releasing the hold on the workpiece W that has been processed in this way, the movable body 21 is moved back from the state shown in FIG. 2 by the operation of the fluid pressure cylinder device 23.

As a result, the regulating member 32 is brought into contact with the screw member 30, the wedge member 33 is retracted, and the inclined surface 33a of the wedge member 33 is separated from the inclined surface 13 of the plunger 4.

Thereafter, the actuating rod 26 is retracted by contact with the support plate 25, and the inclined surface 27b is separated from the inclined surface 10, thereby releasing the clamp of the plunger 4.

Further, due to the engagement of the engagement surface 11.27a, the plunger 4 is lowered against the spring 9 and separated from the workpiece W.

When the movable body 21 returns to the rearward end position as shown in FIG. 1, the operation of releasing the holding of the workpiece W is completed.

As described above, in the present invention, the plunger is brought into contact with the workpiece by a spring, the workpiece is held, the plunger is pressed in the radial direction for friction clamping, and then the plunger is held by a wedge member that presses the plunger toward the workpiece. Since it is a wedge-locked take-off, the plunger can be reliably defined by the wedge lock without distorting the workpiece, and is particularly effective even when an impactful external force such as cutting resistance that occurs during heavy cutting of the workpiece is applied to the plunger. In addition to the clamp provided by the actuating rod, the wedge lock provided by the wedge member is applied to the plunger, so that the plunger does not displace in any way in the direction of detachment from the workpiece, and the workpiece is reliably maintained to prevent chatter or vibration of the workpiece. Distortion can be completely prevented.

[Brief explanation of the drawing]

The drawings show a workpiece holding device according to the present invention, in which FIG. 1 is a longitudinal cross-sectional view showing a state where the workpiece is released, FIG. 2 is a longitudinal cross-sectional view showing the workpiece holding state, and FIG. FIG. 4 is an enlarged view of the lower part of the plunger in FIGS. 1 and 2, viewed from the right. 2... Main body, 4... Plunger, 7... Sliding rod, 9... Spring, 10, 13... Inclined surface, 1
DESCRIPTION OF SYMBOLS 1... Engagement surface, 21... Moving body, 23... Fluid pressure cylinder device, 25... Support plate, 26... Actuation rod, 27... Spring, 27a... Engagement Surface, 27b... Inclined surface, 33... Wedge member, 33a
... Inclined surface, 34... Spring, W... Work.

Claims (1)

[Scope of utility model registration request] A plunger is mounted on the main body so as to be slidable toward the workpiece and biased by a spring in the direction of contacting the workpiece, and a moving body is supported on the main body so as to be slidable in a direction intersecting the moving direction of the plunger. , a fluid pressure cylinder device for moving the movable body is provided, and an actuating rod and a wedge member are supported on the main body so as to be spaced apart in the axial direction of the plunger and slidable in mutually parallel directions; The members are linked to the movable body so as to be relatively movable by a predetermined amount, and first and second springs are separately inserted between the actuating rod and wedge member and the movable body, so that the actuating rod and the wedge member are The wedge member is biased toward the plunger, the actuating rod is formed with an inclined surface that presses and clamps the plunger in a radial direction as the movable body moves forward, and the wedge member is configured to engage with the plunger after being clamped by the actuating rod. Forming a wedge surface that presses this plunger in the axial direction toward the workpiece,
A work holding device characterized in that the pressing force of the second spring that presses the wedge member is set smaller than that of the first spring that presses the operating rod.