JPH0325854Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention uses small holes drilled in a thin plate workpiece, which has many small holes drilled on the same circumference, to position it on the spindle of a lathe in a state of three-point support. This invention relates to a clamp structure for thin plate workpieces that can fix the workpiece.

(Prior art) When finishing the inner diameter of a thin disc-shaped workpiece, the workpiece was conventionally attached to a chuck by hand.

Also, when punching a large number of small holes on the pitch circle of such a workpiece, distortion will occur at various places on the inner and outer circumference of the workpiece, so when tracking this, the pitch circle of the small holes will change depending on the position of the distortion. The center of the spindle may become eccentric with respect to the center of the spindle, so it was necessary to be very careful when aligning the center. Further, a chuck for positioning the tire wheel by inserting a tapered member into a hole provided in the tire wheel and pushing out a chuck pin using a push-out member built into the tapered member is known from Japanese Utility Model Application No. 61-81809. There is.

(Problems that the invention aims to solve) When the workpiece is thin or when turning a large number of workpieces, this conventional method is very time-consuming and has variations in finishing accuracy. There was a problem. Also, Utsukai Showa 61-81809
In the chuck described in the publication, it is necessary to attach the workpiece to the chuck manually or with a separate device, and the positioning is also done by moving the chuck pin using a hydraulically operated extrusion member, so it is easy to cause irregularities in the protrusion and high precision is required. Cannot position with. Furthermore, since the fixing is performed by a separate mechanism, there are problems in that the structure is complicated and it is difficult to perform the chuck operation automatically and quickly.

(Means for Solving the Problems) The present invention has been made in order to solve the problems of the conventional art. The purpose is to provide a clamping structure for a workpiece that allows the center of the pitch circle of this small hole to coincide with the center of the spindle, and that can be immediately fixed to the spindle in a state of three-point support. A clamping device for thin plate workpieces that has many small holes drilled in it is equipped with a reference face plate with protrusions at three points on a predefined pitch circle, a pad facing the protrusions, and a clamp fixed to the spindle of a lathe. A reference face plate and a pad whose axes are aligned with the main body are arranged side by side so that they can move forward and backward, and a workpiece insertion/extraction opening is provided above the reference face plate and the pad, and a workpiece insertion/extraction opening is provided below the insertion/extraction opening. The clamp body is provided with a temporary workpiece holder attached to the clamp body, and the workpiece is inserted through the insertion/extraction port and the protrusion is engaged with the small hole of the workpiece, thereby positioning and fixing the workpiece in a three-point supported state. It has a clamp structure for thin plate workpieces.

(Function) In the clamp structure of the present invention, a reference face plate and a pad are arranged side by side with their axes aligned on the clamp body fixed to the spindle, and protrusions are provided on the reference side of the reference face plate at points that divide the pitch circle into three. ing. Furthermore, either the reference face plate or the pad can be moved back and forth.

A clamp having the above structure rotates together with the spindle. This spindle is stopped at a predetermined position by an indexing device, and the workpiece is inserted between the reference face plate and the pad. Then, the reference face plate or the pad is moved back and forth to bring the distance between the two closer together, and the protrusion provided on the reference face plate is inserted into the small hole of the pad. Since the protrusions are provided at three points on the pitch circle that coincides with the center of the spindle, the workpiece pressed against the pad must necessarily align the center of the pitch circle of the small hole with the center of the spindle and be supported at three points. Fixed. When the spindle is rotated in this state, the workpiece rotates together with the clamp, so the inner diameter of the workpiece can be machined concentrically with the pitch circle of the small hole.

Note that the pitch circle of the small hole drilled in the workpiece and the pitch circle of the protrusion are always made to match. Further, the protrusions used are hard ball-shaped or plunger-shaped.

(Example) Examples of the present invention will be described below based on the drawings.

In the clamp 1 of this embodiment, a reference face plate 2 is attached to a clamp body 4 fixed to a spindle 3 of a lathe. In addition, hard balls 5 are provided as protrusions on the spindle 3 side, which is the reference side of the reference face plate 2, at three equal points on the pitch circle. Incidentally, this ball 5 may be attached so as to be rotatable at the attachment point, or may be fixed.

The pad 6 is arranged at a position facing the ball 5,
Shaft hole 7 of clamp body 4 fixed to spindle 3
It is fixed to the tip of the sleeve 8 which is slidably inserted into the sleeve. Further, a drawbar 9 connected to a rotary hydraulic cylinder (not shown) attached to the rear end of the spindle 3 passes through the axis of the spindle 3, and its tip is connected to the sleeve 8.

In the figure, 10 is a rotation stopper for the sleeve 8, 11 is an insertion/extraction port for the workpiece 12 provided in the clamp body 4, 13 is a workpiece temporary holder attached to the clamp body 4 at a position opposite to the insertion/extraction port 11, and 14 is a temporary workpiece holder. A small hole is drilled on the pitch circle of the workpiece 12, 15 is the chamfered part of the small hole 14, 16 is the axis of the spindle 3, 1
7 is an insertion hole for the cutting tool 18.

In order to grip the workpiece 12 with this clamp 1, first stop the spindle 3 at a predetermined position using an indexing device (not shown), and then insert the workpiece 12 into the insertion/extraction port 11.
send in. In advance, attach pad 6 to spindle 3.
When the workpiece 12 is moved back to the side to leave a space between it and the ball 5, the workpiece 12 falls between the reference face plate 2 and the pad 6 and is held by the workpiece temporary holder 13. Next, when the drawbar 9 is pushed out using a rotary hydraulic cylinder, the pad 6 advances toward the reference face plate 2 and the ball 5 moves into the small hole 14.
The work piece 12 is inserted into the pad 6 and is brought into close contact with the chamfered part 15 so that the pitch center of the small hole 14 coincides with the center of the spindle 3, and the work piece 12 is pressed against the pad 6 and fixed. In this state, the spindle 3 is rotated, the cutting tool 18 is inserted through the insertion hole 17, and the inner diameter of the workpiece 12 is machined. After processing, the spindle 3 is stopped at a predetermined position by an indexing device, and the workpiece 12 is dropped by its own weight.

Therefore, this clamp 1 can automatically accept, center, fix, process, and release a workpiece after processing.

Although the embodiment of the present invention has been described above, the specific configuration of the present invention is not limited to this embodiment.

For example, although the protrusion is a ball 5, the present invention is not limited to this, and may be in the form of a plunger 31 biased toward the pad 6 by a spring 30, as shown in FIG.

In this case, when the workpiece is thin or made of aluminum or the like, there is an advantage that the shock during pressing is softened and the small hole etc. are not deformed.

Further, the reference face plate 2 is fixed to the clamp body 4, and the pad 6 is made to move forward and backward.
As shown in FIGS. 7 and 7, the reference face plate 2 may be made retractable and the pad 6 may be fixed to the clamp body 4. In this case, there is an advantage that even if chips or the like adhere to the projections, they can be easily removed.

Further, the shape of the protrusion is not limited to a ball shape or a plunger shape, but may be any shape that conforms to the shape of the small hole 14. In addition, in the example, the three points are provided at trisecting points on the pitch circle, but the three points do not necessarily have to be at the trisecting points, and as long as they are on the pitch circle, they can be approximate dividing points. There is no difference.

(Effects of the invention) As described above, according to the invention, a workpiece inserted into an arbitrary position of the workpiece temporary holder is supported at three points by the three protrusions provided on the reference face plate, and the center of the spindle and the workpiece are supported at three points. The centers can be matched and fixed to the spindle at the same time.

In addition, this alignment, support, and fixing can be performed accurately by simply moving either the reference face plate or the pad forward or backward, so it can be fully automated, resulting in uniform finishing accuracy and increased work efficiency. can do.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 is a front view, Fig. 3 is a sectional view taken along line A-A in Fig. 1, and Fig. 4 is a sectional view showing an embodiment of the present invention.
The figure is a front view of the workpiece, and FIGS. 5 to 7 are sectional views showing other embodiments. 1... Clamp, 2... Reference face plate, 3... Spindle, 4... Clamp body, 5... Ball, 6
... Pad, 9 ... Drawbar, 12 ... Work, 14 ... Small hole, 16 ... Axis, 31 ... Plunger.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a clamping device for a thin plate workpiece in which a large number of small holes are drilled on the same circumference, a reference face plate provided with protrusions at three points on a predefined pitch circle;
A pad facing the protrusion is provided, and one of the pads and a reference face plate whose axis is aligned with the clamp body fixed to the spindle of the lathe are arranged in parallel so that they can move forward and backward, and the upper part between the reference face plate and the pad is provided. A workpiece insertion/extraction opening is provided at the insertion/extraction position, a workpiece temporary holder attached to the clamp body is provided below the insertion/extraction opening, the workpiece is inserted through the insertion/extraction opening, and the protrusion is engaged with the small hole of the workpiece to remove the workpiece. A clamp structure for thin plate workpieces, which is characterized by positioning and fixing with three-point support. 2. A clamping structure for a thin plate work according to claim 1 of the utility model registration claim, wherein the protrusion is ball-shaped. 3. A clamping structure for a thin plate work according to claim 1, wherein the protrusion has a plunger shape.