JPH0730248Y2 - Mechanism to prevent tilting of workpiece on broaching machine - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to improvement of a work piece mounting portion of a broaching machine, and more specifically, to prevent the work piece from tilting during inner surface broaching to improve its processing accuracy. The present invention relates to an improvement for making it possible to improve.

[Conventional technology]

The broaching machine can finish the inner surface or the surface of the work piece into a predetermined shape at one time, and can quickly make compatible products with good finished surfaces, which is indispensable for mass production. It has become a thing. FIG. 5 is a drawing showing a state in which an inner surface broaching is performed by a conventional broaching machine. As shown in the drawing, the conventional inner surface broaching is a bushing a formed in conformity with the mounting surface of the workpiece W.
Is attached to the broaching machine face plate b, and the workpiece W is brought into contact with the bushing a so that the insertion hole c of the bushing a and the prepared hole d previously formed in the workpiece W are aligned with each other, and the front guide portion of the brooch e is attached. By passing f through the prepared hole d and the insertion hole c, grasping it with the chuck g, and pulling it out, it is possible to perform the cutting work according to the shape of the cutting edge portion h of the broach e in one operation. There is.

[Problems to be solved by the device]

However, in the conventional broaching machine as described above, when the contact surface of the workpiece W contacting the bush a is not perpendicular to the axial center line of the prepared hole d formed in the workpiece W, ,
As shown in FIG. 5, it is set with a gap s between the bush a and the contact surface of the workpiece W, and when the broach e is pulled out in this state, the bush a is pulled due to the pulling force. The workpiece W gradually inclines in the direction in which the contact surface of the workpiece W comes into close contact, and as a result, the axial center line j of the prepared hole d deviates from the axial center line i of the broach e as shown in FIG. There is a problem that the processing hole that should originally be formed along the axial center line j of the prepared hole d is deviated from the center line j and the processing accuracy deteriorates.

The present invention attempts to solve the above problems and attempts to improve the problems. An object of the present invention is to prevent tilting of a workpiece having a bad squareness of the contact surface when cutting the workpiece. The specific means and actions are as follows.

[Means for Solving the Problems]

A cylindrical bush is attached to the front side of the broach insertion hole formed in the broaching machine face plate, and a plurality of cylinder chambers are provided in the bush along the axial direction. While the heads of the piston pins are inserted into the cylinder chambers, the heads of the pistons projecting forward are retractably inserted into the cylinder chambers, and the oil sumps are filled with oil. A disc-shaped shim plate is interposed between the part and the workpiece.

[Action]

If the contact surface of the work piece is not a right angle, a part of the contact surface of the work piece biases the shim plate unevenly, causing multiple piston pins that interlock via hydraulic pressure to move forward and backward according to the pressing force. Then, the shim plate is inclined so that the contact surface of the workpiece is evenly contacted with the shim plate. As a result, the gap between the contact surface of the workpiece and the shim plate is eliminated, and tilting of the workpiece can be prevented.

〔Example〕

Specific embodiments of the present invention will be described below with reference to the accompanying drawings. 1 and 4 are drawings showing an embodiment of the present invention, in which 1 is a vertical broaching machine, 2 is a broaching machine face plate constituting the broaching machine, and the center of the broaching machine face plate 2 An insertion hole 3 is opened in the vertical direction, and a large-diameter recess 4 is formed on the upper side of the insertion hole 3 via a step. The recess 4 has a cylindrical bushing. 5 is fitted. An insertion hole 7 for the brooch 6 is vertically formed through the bush 5 at the central portion thereof, while a plurality of cylinder chambers 8 are formed in the peripheral portion of the bush 5 with an opening 8'on the surface side of the bush 5. The holes are drilled at regular intervals. An oil sump 9 is formed at the back of each cylinder chamber 8 ...
Thus, the cylinder chambers 8 ... Are provided so as to communicate with each other. A cover plate 10 is fixed to the front surface side of the bush 5,
A window hole 11 is opened in the cylinder 10 at a position corresponding to the opening 8'of each cylinder chamber 8. A piston pin 12 is inserted into each cylinder chamber 8 ... Same piston pin
The head 12 'of 12 is formed to have a small diameter through the step portion 13,
12 'is projected from the window hole 11 so as to be retractable. The back side of each piston pin 12, that is, the oil reservoir 9 is filled with oil, and each piston pin 12 is provided so as to advance and retreat in conjunction with each other via the hydraulic pressure of the oil. Reference numeral 14 is a shim plate interposed between each piston pin 12 and the workpiece W, and has a disc-like shape with an insertion hole 14 'in the center thereof. The broach 6 includes a shank 6a, a front guide portion 6b, and a cutting edge portion in order from the front end.
A chuck 15 for pulling the broach 6 is connected to the shank 6a by forming a rear guide portion 6d and a rear guide portion 6d.

Next, the operation will be described.

Each piston pin protruding from the bush 5 as shown in FIG.
A shim plate 14 is interposed between the head 12 'of 12 ... and the workpiece W, and the front guide portion 6b of the broach 6 is inserted into a prepared hole d formed along the axial center line of the workpiece W. And
In a state where the shank 6a of the broach 6 is inserted into the insertion holes 14 ', 7, 3 and the chuck 15 is connected to the tip of the insertion hole 14', 7, 3, the contact surface of the workpiece W with the shim plate 14 is the workpiece W. In the case where it is not formed at right angles to the axial center line of the prepared hole d (the contact surface is usually not perfectly right because an error occurs due to the machining accuracy of the machine tool). As shown in the figure, the contact surface of the workpiece W is set so that only a part thereof abuts on the shim plate 14 and the other part is lifted from the shim plate 14 with a gap s. When the broach 6 is driven in the pulling direction to perform the broaching in this state, the workpiece W is pushed by the pulling force of the broach 6 into the bush 5.
It is pressed to the side, but first its tensile force is the workpiece W.
Since a part of the contact surface of the contact portion is concentrated on the portion of the shim plate 14 with which it abuts, the piston pin 12 (the piston pin 12 on the left side in the drawing) located on the rear surface of the portion is in contact with the cylinder chamber 8.
As the piston pin 12 is pushed in, the other piston pins 12 are pushed out by the hydraulic pressure in the oil sump 9 as much as the piston pin 12 is pushed in.
As shown in FIG. 4, the shim plate 14 is inclined by the advancing and retreating action of the ... And evenly abuts against the abutting surface of the work W, and the shim plate 14 holds the work W without tilting it to prepare a pilot hole. It is possible to accurately perform broaching of the workpiece W based on d.

Although the vertical broaching machine has been described in the above embodiment, the tilting prevention mechanism for the workpiece according to the present invention can be incorporated in the horizontal broaching machine.

[Effect of device]

The present invention is configured as described above, and the shim plate is inclined by the advancing / retreating action of the plurality of piston pins that are interlocked via the hydraulic pressure as described above, and the shim plate is evenly contacted with the contact surface of the workpiece. By bringing them into contact with each other and holding them, it is possible to prevent the tilting of the work piece whose contact surface is not at right angles to the axial center line of the prepared hole, and to improve the working accuracy. I arrived.

[Brief description of drawings]

1 to 4 are drawings showing an embodiment of the present invention. FIG. 1 is a side sectional view of a broaching machine according to the present invention, and FIG.
FIG. 4 is a plan view of the bush, FIG. 3 is a side sectional view of the bush, FIG. 4 is an explanatory view of the operating state of FIG. 1, and FIGS. 5 and 6 are drawings showing a conventional example. FIG. 5 is a side sectional view of a conventional broaching machine, and FIG. 6 is an operation state explanatory view of FIG. W ... Jig, d ... Pilot hole, s ... Gap, 1 ... Broaching machine, 2 ...
Broaching machine face plate, 3 ... insertion hole, 4 ... recessed part, 5 ... bush, 6 ... brooch, 6a ... shank, 6b ... front guide part, 6c
... cutting edge part, 6d ... rear guide part, 7 ... insertion hole, 8 ... cylinder chamber, 8 '... opening part, 9 ... oil sump part, 10 ... lid plate, 11 ... window hole, 12 ... piston pin, 12' ... head, 13 ... step, 14 ... shim plate, 14 '... insertion hole, 15 ... chuck.

Claims (1)

[Scope of utility model registration request] 1. A cylindrical bush is attached to the front side of a broach insertion hole formed in a broaching machine face plate, and a plurality of cylinder chambers are provided in the bush along the axial direction. While communicating with each other through the oil sump formed in the, the piston pin that protrudes the head toward the front side is inserted into each cylinder chamber so that it can move back and forth.
A mechanism for preventing tilting of a workpiece in a broaching machine, in which the oil sump portion is filled with oil and a disk-shaped shim plate is interposed between the head of each piston pin and the workpiece.