JPH0866807A - Clamping device for workpiece having deformed peripheral surface - Google Patents

Abstract

PURPOSE: To make a quick replacement of hold-down piece, when a workpiece is changed, in a chuck restrainingly suppressing the deformed peripheral surface of a part of the workpiece by a hold-down piece for machining the other part of the workpiece. CONSTITUTION: A movable piece 8 is engaged in a freely movable manner along a groove 7 in the radial direction of a chuck body 4'. A reference piece 15 is connected to the movable piece 8. The piece 15 and a binding piece 16 are mortised together in a detachable manner by sticking butting surfaces 17, 18 fast together. When the two are mortised together, a lock protrusion 25 on the end of a clamp lever 21, which is freely oscillating by being pivoted to the reference piece 15, is engaged with a lock recessed part 26 in the binding piece 16 by being pushed with a spring 27 so that the binding piece 16 may not come off from the reference piece 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamping device for a chuck which holds a work piece during cutting by a lathe, and particularly, enables efficient work of exchanging a presser piece for holding a work piece having a deformed outer peripheral surface. Clamp device.

[0002]

The use of lathes for turning workpieces is well known.

The main part of a generally known lathe is shown in FIG.
As shown in (a schematic side view of a lathe), a spindle head 1 is rotatably supported by a spindle 3 via a plurality of bearings 2, 2 and a chuck body 4 is fixed to the tip of the spindle 3. There is. The main shaft 3 is rotationally driven by a variable speed AC inverter motor 6 via a V belt 5.

The axially outer end surface of the chuck body 4 is shown in FIG.
As shown in (front view of the chuck) and FIG. 6 (A-A cross section of FIG. 5), four (some other numbers) radial guide grooves 7, 7 are formed at equal intervals. The moving piece 8 (FIG. 6), which is driven in the radial direction of the chuck body 4 simultaneously and in synchronization with the same direction, is engaged with the groove 7. Moving piece 8
A holding piece 9 (referred to as a claw) that holds and holds the work piece is fixed to the bolt with a bolt 10. Numeral 11 is a tenon for controlling the connecting position of the pressing piece 9. The holding piece 9 holds all the moving pieces 8 in synchronism with the central direction of the chuck body 4 to hold and hold the workpiece and fix it to a predetermined position on the end surface of the chuck body 4, or the moving piece 8 The work piece is released by synchronously moving the work pieces in the opposite direction, and the end of each holding piece 9 corresponds to the work piece outer peripheral surface so that the end portions of the holding pieces 9 fit well to the work piece outer peripheral surface. It is formed into a shape.

[0005]

Generally, when the outer shape of a work piece to be cut is simple and a small number of kinds are mass produced,
Although it is not a problem, it has a complicated outer shape and an asymmetrical shape such as the wheel cylinder case 12 of the automobile brake shown in FIG. 7 (side view of the workpiece) and FIG. 8 (bottom view of FIG. 7). Yes, the cylindrical portion 13 is machined in a workpiece whose outer diameter, size, etc. differ depending on the type of vehicle, wheel size, etc. to which it is mounted, and which requires high accuracy of attachment to the chuck. In this case, a pressing piece 9 suitable for mounting cylinder cases having different outer surface shapes is prepared, and when cutting of the previous cylinder case is stopped and cutting of a different cylinder case is newly started, the pressing piece is suppressed each time. The piece 9 must be exchanged (set change).

However, the pressing piece 9 is attached to the moving piece 8 by the bolt 1
Since it is fixed by 0, in order to replace the pressing piece 9, it is necessary to loosen the bolt 10 to remove the pressing piece 9 and to attach a new pressing piece 9. Therefore, it takes a lot of time (about 15 minutes) for exchanging the presser pieces, resulting in poor work efficiency and high product cost. Therefore, there is a demand for shortening the above-mentioned piece exchange time.

[0007]

A clamping device for a workpiece having a modified outer peripheral surface according to the present invention is designed to form a cylindrical surface on a part of the workpiece having the modified outer peripheral surface by a lathe. The outer peripheral surface of the irregular shape existing in the other part is suppressed and held. Such a clamp device for a workpiece having a modified outer peripheral surface of the present invention is fixed to the tip of the main shaft of the lathe concentrically with the main shaft, and is radially arranged on the axial end face of the chuck body that rotates together with the main shaft. A plurality of guide grooves are formed, and a moving piece that is displaced in the radial direction in synchronization with each guide groove is engaged in each guide groove, and a reference piece is superposed on the moving piece and joined. The end surface of the reference piece on the center side of the chuck body is used as a butt surface, and the butt piece that has a butt surface that is in close contact with this butt surface and is in close contact with both of the butt surfaces is connected to the reference piece by a tenon. The connecting piece is detachably connected to the connecting piece, and a curved surface that can hold the deformed outer peripheral surface of the workpiece is formed on the end surface on the center side of the chuck body and a locking recess is formed on the side surface to swing the clamp lever. Pivotally attached to the side of the reference piece, Is formed at the end of the clamp lever of the clamp lever on the center side of the chuck body, and a spring is provided to elastically press the locking projection toward the locking recess. Consists of

[0008]

In the clamp device of the present invention, the reference piece and the connecting piece, which are connected to the moving piece that moves in synchronism with each other in the radial direction along the outer end surface of the chuck body, can be detached by closely contacting the butting surfaces. Since the engaging projection of the clamp lever pivotally attached to the reference piece is engaged with the engaging recess on the side surface of the connecting piece to prevent both pieces from coming off, the clamp lever is connected from the connecting piece. By swinging in the direction of separating, releasing the engagement and pulling the connecting piece toward the center of the chuck body, the tenon connection with the reference piece can be released and the connecting piece can be separated from the reference piece. By operating to, a new connecting piece can be connected to the reference piece. At this time, if the end of the connecting piece on the abutting surface side hits the inclined surface of the engaging protrusion of the clamp lever and pushes the lever open, connection is quickly performed without operating the clamp lever when joining the connecting pieces. be able to.

[0009]

1 to 3 show an embodiment of the present invention, FIG. 1 is a front view of a clamp device, FIG. 2 is a side view of the clamp device shown in FIG. FIG. 3 is a schematic view showing a state in which the clamp lever is pushed open at the time of connecting the connecting pieces. The same parts as those of the above-mentioned conventional example are designated by the same reference numerals and the description thereof will be omitted.

The chuck body 4'is similar to the conventional chuck body 4 shown in FIGS. 4 to 5, and although not shown, it is attached to the tip of the spindle 3 rotatably supported by the headstock 1.
It rotates together with the main shaft 3. This chuck body 4 '
A plurality of (four in this embodiment) guide grooves 7 are formed on the outer end surface in the axial direction in the radial direction from the center, as in the conventional case, and a moving piece 8 of FIG. 6 is formed in each guide groove. Are engaged in this way. The plurality of moving pieces 8, 8 are driven in the radial direction in the groove 7 in synchronization with each other as in the conventional case.

A reference piece 15 is fixed to each moving piece 8 by bolts 10 and 10, like the conventional holding piece 9 shown in FIG. However, the reference piece 15 has a shorter length than the holding piece 9 of FIG. 5, and the connecting piece 16 can be freely connected to the inner end of the holding piece 9 to hold the workpiece. The connection between the reference piece 15 and the connecting piece 16 is performed as follows.

The contact surface between the reference piece 15 and the connecting piece 16 is
The abutting surfaces 17 and 18 (which may be curved surfaces, but flat surfaces in this embodiment) that are in close contact with each other are provided, and two tenons 19 are fixed to the reference piece 15 so as to protrude from the abutting surface 17. The butt surface 18 of the connecting piece 16 is provided with a mortise hole 20 which is tightly fitted in the tenon 19 in a detachable manner. As a result, the tenon 19 is fitted into the tenon hole 20 and the reference piece 15
When the mating surfaces 17, 18 with the connecting piece 16 are brought into close contact,
Both pieces have the same shape as the pressing pieces 9 in FIG. Connecting piece 1
Since the tip of 6 is formed in a shape corresponding to the outer peripheral surface of the work piece, by synchronously moving the moving piece 8 toward the center of the chuck body 4 ', the work piece is surely held and held. become able to. On the contrary to the above, the tenon 19 may be fixed to the connecting piece 16 and the tenon 20 may be formed in the reference piece 15.

Further, in order to prevent the connecting piece 16 connected to the reference piece 15 as described above from coming off from the reference piece 15, a clamp lever 21 is provided. The clamp lever 21 inserts the arm 23 formed in the middle portion into the notch recess 22 formed in the side surface of the reference piece 15, and the pivot bolt 24
Is pivotally attached to the reference piece 15, and the lever 21 is swung about the bolt 24 so that the locking projection 25 at the tip can be engaged with or disengaged from the locking recess 26 formed on the side surface of the connecting piece 16. . A spring 27 is hooked on the lever 21 so that the locking projection 25 at the tip of the lever 21 engages with the locking recess 26 of the connecting piece 16.
The lever 21 is caused to exert an elastic force in the direction of engaging with.
This spring is as shown in FIG. 1 (not shown in FIG. 2).
Not only a wire bent into a U shape, but also a pivot bolt 2
The coil spring fitted to 4 has both ends locked to the reference piece 15 and the clamp lever 21, and a coil spring or a leaf spring is interposed between the base of the clamp lever 21 and the reference piece 15 by compression. Ordinary spring device such as one in which both ends of the coil-shaped tension spring are locked to the clamp levers 21, 21 on both sides of the reference piece 15 so that the locking projections 25, 25 of both levers are drawn can do. The clamp levers 21 are provided on both sides of the reference piece 15,
The locking projections 25 are locked on both sides of the connecting piece 16 so that the connecting piece 16 does not come off the reference piece 15.

In addition, the structure in which the clamp lever 21 is pivotally attached to the reference piece 15 is also provided on the outside by the notch recess 22 and the arm 23.
The step portion is laterally projected from the reference piece 15 in a shelf shape, and the clamp lever 21 is pivotally attached to this step portion, or the arm 23 of the clamp lever is pivotally attached to the upper surface of the reference piece 15, so that the clamp lever 2
1 is bent into a stepped shape, and when the connecting pieces 16 are joined, the locking projections 25 at the ends are locking recesses 2 on the side surfaces of the connecting pieces 16.
It can also be configured to engage 6.

Because of this structure, the bases of the two clamp levers 21, 21 (radial outer ends in FIG. 1)
By pushing the two toward each other
Is released from the locking recesses 26, 26, and the connecting piece 16 is pulled out toward the center of the chuck body 4'and the tenon 19,
If the mortise hole 20 is removed, the previously used connecting piece 16
Can be separated from the reference piece 15 and removed from the chuck body 4 '.

Next, a new set of connecting pieces is attached to each reference piece 15.
, A new work piece can be attached to the chuck body 4 '. That is, a new connecting piece whose tip has a shape that matches the outer peripheral surface of a new workpiece is formed with a butt surface that is in close contact with the butt surface 17 of the reference piece, and matches the tenon 19 of the reference piece. By forming a tenon to be formed and fitting the tenon into the tenon 19, a new workpiece can be reliably held. Since this new connecting piece is also formed with a locking recess that engages with the locking projection 25 of the clamp lever 21, the new connecting piece is joined to the reference piece 15 in exactly the same manner as the previous connecting piece. As a result, a new workpiece can be securely held on the chuck body.

In this way, the tips of the clamp levers 21, 21 are opened to release the locking projections 25, 25 from the locking recesses 26, and the connecting piece 16 used previously is pulled out to remove the reference piece 15.
Then, a new connecting piece is attached to the reference piece 15 and is prevented from coming off by the clamp lever 21, so that the connecting piece can be replaced in an extremely short time (about 3 minutes).

As shown in FIG. 3, when the connecting piece 16 is connected to the reference piece 15, the corner 18a of the abutting surface 18 contacts the inclined surface 25a of the locking projection 25 and the clamp lever 21.
If it is configured to push open, the abutting surfaces 17, 1
Since the locking projection 25 automatically engages with the locking recess 22 due to the spring 27 when 8 is in close contact, when the connecting piece 16 is connected to the reference piece 15, the clamp lever 21
This eliminates the need to operate the and makes this connection quick.

Since the moving piece 8 and the reference piece 15 are always connected to each other, they can be formed in the same body and the connecting piece 16 can be attached to and detached from them.

[0020]

Since the clamping device for a workpiece having a modified outer peripheral surface of the present invention is constructed and operates as described above, workpieces having different outer shapes and sizes are attached to the chuck body. The holding piece can be converted very quickly by replacing the new connecting piece with the previously used connecting piece and connecting it to the reference piece. Therefore, the time loss is remarkably reduced as compared with the conventional work, the work efficiency is lowered, and the product cost is suppressed. or,
In the past, the holding piece 9 for holding down the work piece was remade every time the work piece changed.
Since it is divided into the connecting pieces 16 and only the connecting pieces are remade, the effect of reducing the material cost and the processing cost of the pieces is great.

[Brief description of drawings]

FIG. 1 is a front view of a clamp device according to an embodiment of the present invention.

FIG. 2 is a side view of the clamp device shown in FIG. 1 excluding the left side pieces, the clamp lever, and the like.

FIG. 3 is a schematic view showing a state in which a clamp lever is pushed open at the time of connecting connecting pieces.

FIG. 4 is a schematic side view showing a configuration of a main part of a conventional lathe.

FIG. 5 is a front view of a conventional chuck.

6 is a cross-sectional view taken along the line AA of FIG.

FIG. 7 is a side view illustrating a workpiece.

8 is a bottom view of the work piece viewed from the lower side of FIG. 7. FIG.

[Explanation of symbols]

 1 Headstock 2 Bearing 3 Spindle 4, 4'Chuck body 5 V-belt 6 Inverter motor 7 Guide groove 8 Moving piece 9 Holding piece 10 Bolt 11 Mortise 12 Wheel cylinder case 13 Cylindrical part 15 Reference piece 16 Connecting piece 17, 18 Butt Surface 18a Corner 19 Mortise 20 Mortise 21 Clamp lever 22 Notch recess 23 Arm 24 Axis bolt 25 Locking projection 25a Sloping surface 26 Locking recess 27 Spring

Claims (2)

[Claims] 1. A clamp device for a workpiece, which holds a deformed outer peripheral surface existing in another portion of the workpiece so as to form a cylindrical surface on a part of the workpiece having the deformed outer peripheral surface by a lathe. A plurality of guide grooves are formed in the radial direction on the axial end surface of the chuck body that is fixed concentrically to the main shaft of the lathe and rotates together with the main shaft,
A moving piece that is displaced radially in synchronism with each other along each guide groove is engaged in each guide groove, and a reference piece is superposed on the moving piece and joined together. The connecting piece detachably connected to the chuck body center side of the reference piece by having the abutting surface in close contact with this abutting surface and bringing the both abutting surfaces into close contact with each other to join the tenon with the reference piece. Has a curved surface capable of holding the deformed outer peripheral surface of the workpiece on the end surface on the center side of the chuck body and a locking concave portion on the side surface, and the clamp lever is pivotally attached to the reference piece so as to swing. At the end of the clamp lever on the center side of the chuck body, a locking projection that engages with the locking recess of the connecting piece is formed, and a spring that elastically presses the locking projection toward the locking recess is provided. Clamping device for workpieces with irregular outer peripheral surface 2. The clamp device for a workpiece having a deformed outer peripheral surface according to claim 1, wherein the moving piece and the reference piece bolted to the moving piece are integrally formed.