JPS624408Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an eccentric chuck that automates eccentricity adjustment to accommodate various workpieces having eccentric machining parts.

Conventionally, for eccentric workpieces, the chuck is mounted eccentrically on the eccentric plate that is rotatably mounted eccentrically on the face plate of the spindle, and the chuck is adapted to the workpiece by rotating the face plate and the eccentric plate relative to each other. A mechanism for setting the amount of eccentricity is known. However, all of these methods are manually adjusted and set according to the amount of eccentricity of the machined part or workpiece. Therefore, there was a drawback that adjustment was troublesome and time consuming. Also recent NC
In the case of unmanned automatic operation due to the increasing number of machines, it is not possible to handle workpieces that have concentrically machined parts and eccentrically machined parts, or different types of workpieces that have different amounts of eccentricity. This had become an obstacle.

This idea was created in view of the above, and aims to provide an eccentric chuck that can automatically adjust the amount of eccentricity based on commands by utilizing the functions of an NC lathe. The chuck is mounted eccentrically with respect to this holding center, and has an eccentric mounting plate having one positioning pin hole in the eccentric direction of the chuck or 180 degrees opposite direction, and 1 provided on a circumference centered on the eccentric point, which is the center of rotation of the eccentric mounting plate, and passing through the center of the pin hole.
It is provided with one or more positioning pins and means for fixing the face plate and the eccentric mounting plate, and also serves to pull out the positioning pin from the eccentric mounting plate when adjusting the amount of eccentricity, and also to prevent the eccentric plate from rotating. The chuck drive pin is provided on the tool rest so as to be floating.

Embodiments of this invention will be described below based on the drawings. A mounting disc 3 centered with a shot taper is fastened to the front end of a main shaft 2 rotatably supported on a headstock 1 of an NC lathe by a set screw 4. On this mounting disc 3, a face plate 5 is fixed with a set screw 6, which is centered by a dowel and has a cavity 17 whose inner diameter is used as a proof surface and whose center is at a position eccentric from the center. ing. Further, a plurality of holes 8 are bored in the direction of the rotation axis on the circumference concentric with the cavity 17 on the side surface, and a positioning pin 9 with a small diameter tip for positioning an eccentric mounting plate 13, which will be described later, is inserted into the hole 8 with a spring. 10, it is pushed forward and inserted. The position of this pin 9 is calculated in accordance with the eccentricity of the workpiece so that the necessary eccentricity of the chuck can be obtained when the eccentric mounting plate is positioned. The front surface of the face plate 5 has a dowel that fits into the inner diameter 7 serving as a proof surface, has one through hole 11 into which the positioning pin 9 is inserted, and holds an eccentric mounting plate 13 having a flange 12. Holding plate 1 having a relief and having a diameter larger than the outer diameter of the flange 12
4, it is held relative to the face plate 5 so that it can move only in a direction perpendicular to the axis of rotation. A circular recess 15 is cut at the center of the eccentricity on the rear surface of the eccentric mounting plate 13, and a tightening piece 16 has a diameter smaller than the diameter of the recess by two or more.
is inserted, and a backing plate 18 with a diameter smaller than 2 and having a round window in the center is inserted into the back surface of the eccentric mounting plate 13 by a set screw 19 to accommodate this piece. It is fixed.

This tightening piece 16 is connected to a tightening rod 21 connected to a piston fitted in a hydraulic cylinder 20 provided at the rear end of the main shaft. After the adjustment is completed, the pressurized oil is switched and the tightening piece 16 is sent in the tightening direction to pull the backing plate 18 backward. Further, a chuck 22 is fixed to the front surface of the eccentric mounting plate 13 at a position 180 degrees away from the positioning pin hole 11 (or may be provided in the same direction). This chuck 22 has a well-known structure, and uses compressed air to operate a piston in a built-in cylinder to open and close the chuck pawl 23. Reference numeral 24 denotes an air supply port provided in the chuck 22 at a constant angle (180° in the figure) with respect to the positioning pin hole 11, and communicates with the internal pneumatic cylinder so that the supply port 24 is positioned at the origin position (FIG. 1). When the chuck pawl 23 is opened and closed, the compressed air supply device 25 provided at the corresponding position is connected to open and close the chuck pawl 23. Further, a chuck drive pin 26 is attached to the turret tool rest 27 to release the engagement between the eccentric mounting plate 13 and the face plate during eccentric adjustment and to prevent the mounting plate 13 from rotating.
The rotating turret is provided at one corner of the rotating turret so that it can float in the radial direction. When this pin 26 is indexed to a horizontal position by the turret and positioned with the main axis (Z-axis) direction perpendicular to the main axis (X-axis), the tip of the pin is inserted into the positioning pin hole 11 of the eccentric mounting plate 13. Place the positioning pin 9 on the eccentric mounting plate 13
It has the role of preventing rotation as well as allowing it to escape to the surface. 28 is a tool attached to another tool rest 29, 28-1 is for external cutting, and 28-2 is for boring. Further, 30 is a C-axis indexing unit for indexing the main axis. In addition, C-axis indexing unit 3
Instead of 0, a multi-position indexing unit may be used, as shown in FIG. 4, in which an indexing plate 31 with a plurality of indexing grooves cut into the rear end of the main shaft 2 is fixed and a stop pin 32 is provided for moving in and out.

Next, the operation of the configuration of this invention will be explained. A workpiece having a hole eccentric to the outside diameter is attached to the chuck 22 so that the center of the outside diameter coincides with the center of the spindle. This outer diameter cutting is done using turret 27 or 2.
When the cutting is completed using the tool 28-1 of No. 9, a command for internal machining is issued from the NC device. Therefore, the main shaft 2, which has not yet stopped or is stopped at an undefined position, is indexed at low speed by the C-axis control unit 30, and the chuck 22 is rotated to move the positioning pin hole 11 to the origin position before the horizontal position (see Fig. 1). )
is allocated to.

A transverse feed stand (not shown) equipped with a tool rest 27 is positioned in the direction perpendicular to the main axis (X-axis), and a saddle (not shown) is sent in the direction of the main axis (Z-axis), and the chuck drive pin 26 is inserted into the positioning pin hole 11. Ru. When the pin is inserted, the positioning pin 9 is pushed out, and at the position where it comes out of the eccentric mounting plate 13, the lock between the face plate 5 and the eccentric mounting plate 13 is released, and Z-axis feeding is stopped.

The oil passage of the hydraulic cylinder 20 is switched, the tightening rod 21 and the tightening piece 16 are released from tightening, and relative rotation between the face plate 5 and the eccentric mounting plate 13 becomes possible.

The main shaft 2 is rotated again at low speed. At this time, since the eccentric mounting plate 13 is prevented from rotating by the chuck drive pin 26, only the face plate 5, which is integral with the main shaft, is rotated. The C-axis control unit 30 determines a pin position that corresponds to the eccentricity of the inner diameter of the workpiece, and the main shaft is stopped. Even if another positioning pin 9 comes above the positioning pin hole 11 during this indexing, it will not be inserted and will pass through the hole because the chuck drive pin 26 is fitted. At this time, the angle of the pin hole 11 with the spindle indexing origin and the distance from the spindle center are stored in the NC device.

When the face plate 5 is indexed, the saddle is sent in the opposite direction of the Z axis, the chuck drive pin 26 comes out, and the positioning pin 9 is inserted into the pin hole 11.

Switch the oil path of the hydraulic cylinder 20 and tighten the tightening piece 16.
Pull the eccentric mounting plate 13 through the contact plate 18 and attach it to the face plate 5.
Fixed to.

The turret tool post 20 or 29 is rotated, the boring tool 28-2 is selected, and the X-axis and Z-axis feeds are applied to perform inner diameter machining of the workpiece.

When the inner diameter machining is completed and the machining of the gripped workpiece is completed, the spindle is indexed and stopped according to the angle at which the chuck is released from eccentricity, that is, the angle between the spindle indexing origin and the pin hole 11 that was previously memorized, and the chuck drive is stopped. The pin 26 is positioned at the previously memorized position in the X-axis direction, the chuck driving pin 26 is inserted into the pin hole 11, and the relative relationship between the main shaft and the chuck is returned to the origin by C-axis control.

A loading device (not shown) grips the workpiece.

The compressed air supply device 25 moves forward and the chuck 22
The chuck pawl 23 is opened by moving a built-in piston connected to the air supply port 24 of the chuck.

The workpiece is removed by the loading device, a new workpiece is transported, the supply path of the compressed air supply device 25 is switched, the piston moves backward, and the chuck pawl 23 is closed. The supply device 25 is retracted.

When machining a workpiece concentrically, a tool is selected and machining begins, and when machining eccentrically, the eccentricity adjustment described above is performed.

As described in detail above, this invention has a mounting plate that is eccentric to the face plate so that its relative position can be changed, a positioning pin hole is provided in the mounting plate, and a check is installed at a position 180° apart from the positioning pin hole by the same amount of eccentricity. is installed, multiple positioning pins are provided on the face plate, and a chuck drive pin is installed on the tool post to release the lock between the face plate and the mounting plate, and prevent the mounting plate from rotating. Eccentricity adjustment is performed using commands from the NC device. As a result, the eccentricity can be adjusted automatically by making full use of the functions of the NC device, making it possible to handle a wide range of workpieces with different eccentricities and different types of workpieces. It has features that greatly contribute to the realization of unmanned driving.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of this invention, FIG. 2 is a partial vertical sectional view of the chuck, FIG. 3 is a front view of the chuck, and FIG. 4 is a schematic diagram of another embodiment of the indexing unit. 2... Main shaft, 5... Face plate, 8... Spring, 9...
Locating pin, 11... Locating pin hole, 13...
...Eccentric mounting plate, 16...Tightening piece, 20...Hydraulic cylinder, 21...Tightening rod, 22...Chuck, 2
3...Chuck pawl, 26...Chuck drive pin, 30...C-axis control unit.

Claims (1)

[Scope of utility model registration request] A chuck mounting face plate fixed to the main shaft of a numerically controlled lathe, an eccentric mounting plate mounted so as to be rotatable relative to the face plate around a point eccentric to the rotation center of the face plate, and a rotation axis attached to the eccentric mounting plate. one locating pin hole drilled in the direction, and one or more holes provided on a circumference centered on a point eccentric by the amount on the side surface of the face plate and passing through the axis of the locating pin hole, respectively. A locating pin that determines the amount of eccentricity by being fitted and urged by a spring in the direction of fitting into the locating pin hole, and a locating pin that is mounted on the eccentric mounting plate in the same direction as the locating pin hole with respect to the eccentric center of the eccentric mounting plate. or a chuck body mounted eccentrically by 180 degrees in the opposite direction, a means for fixing the eccentric mounting plate to the face plate, and a means for fixing the eccentric mounting plate to the face plate, and the eccentric mounting plate is fitted into the positioning pin hole placed at a fixed position. A chuck drive pin provided on the turret to prevent rotation and push out the fitted positioning pin to release the lock between the eccentric mounting plate and the face plate and to float in the cutting direction of the turret, and the main shaft. automatic eccentric chuck comprising low speed rotation and C-axis control means.