JPH0260461B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chuck transfer device;
The purpose is to provide a device that can always position the gripping center at the center of the spindle when simultaneously gripping and conveying chucks on multiple spindles, thereby reliably eliminating troubles caused by misalignment. It is in.

However, like the device we are currently considering, the chuck is rotated every 90 degrees or 180 degrees between the four main axes.
When trying to transfer chucks between the transfer device and each spindle, it is necessary to minimize misalignment between the four spindle centers and the four chuck centers gripped by the transfer device. Troubles are likely to occur due to wear and distortion of component parts, and it is difficult to guarantee long-term accuracy and machine life.

Therefore, the present invention was proposed, and the present invention will be explained below with reference to embodiments shown in the drawings.

The overall structure is described in detail in Japanese Patent Application No. 55-584 "Machine Tool with Actual Chuck Changing Device" filed by the same applicant as a patent related to the present invention.

Its structure is such that a headstock is placed on the bed of a machine tool, and two main shafts are rotatably provided within the headstock parallel to the horizontal line.

A chuck is attached to the end of each main shaft, which is pulled and clamped to the rear of the main shaft via a joint.
Further, in order to process the workpiece attached to this chuck, two tool rests are provided opposite to the two main spindles so as to be movable back and forth in a direction orthogonal to the axis of the main spindles.

A transfer base is placed on the top of the headstock, and within the transfer base, a pivot shaft of the chuck exchange device of the present invention is located on an intermediate portion between the two main shafts.

Although not shown, a box provided on the transfer base is provided with a device for fastening the chuck with a claw.

The present invention forms part of such a mechanical configuration.

The code 1 in the figure is the transfer base (first
(Fig.), a transfer pivot shaft 2 is pivotally supported in the center thereof, and a starting cylinder 3 for operating various members to be described later is attached toward its axis.
Reference numeral 4 denotes a rotating shaft fixed to the base 1 at the tip of the piston rod 3a of the cylinder 3, on which the pawl 5 is supported. The claw body 5 has a concave groove 5a,
A piston rod 3a is formed in the concave groove 5a.
An engagement pin 6 provided at the tip is engaged, and the claw body 5 is rotated around the rotating shaft 4 as the piston rod 3a moves back and forth. 7 is a locate pin.

On the other hand, to continue the explanation with reference to FIG. 4, a transfer body 8 is disposed in front of the base 1 and is supported by the pivot shaft 2.
A positioning hole 9 is formed in the inner peripheral edge of the body 8, and the transfer body 8 can be fitted into and removed from the locate pin 7 by a means for moving the transfer body 8 back and forth (not shown). When changing the position in the circumferential direction, the transfer body 8 is moved forward and removed from the pin 7, and then rotated, for example, 90 degrees in the circumferential direction by a rotating means (not shown), and then moved backward again. Then, the pin 7 is fitted into the positioning hole 9 of the transfer body 8, and the transfer body 8 is positioned.

A disc cam 11 is supported on a central bearing 10 of the body 8, and between the disc cam 11 and the body 8, there are four pairs of dog-shaped chuck holding arms 12, 12' facing each other. 4 chuck holding arm opening/closing cams 13 and 4 chuck pressing arms 1
5 is placed.

Further, four connecting pins 16 are protruded from the base 1 side of the disc cam 11, and when the disc cam 11 retreats to the base 1 side together with the body 8, one of the connecting pins 16
is configured to engage with a groove 5b of the pawl body 5, and as the rod 3a of the cylinder 3 expands, the disc cam 11 is rotated clockwise in FIG. A substantially swastika-shaped claw plate 17 is integrated on the front surface of the disc cam 11, and four engagement recesses 17a are formed around the circumference thereof. Furthermore, a chuck holding arm opening/closing cam 13 is provided on the circumferential surface of the disc cam 11.
A notch 11a is formed in which the cam follower 13a of the cam follower 13a engages.

On the other hand, the chuck holding arm 12 is supported at its center by a pivot shaft 18 projecting from the body 8. Further, a holding protrusion 19 is provided protruding from the tip, and a cam follower 20 is provided protruding from the base. Furthermore, the chuck holding arm opening/closing cam 13 is
A rotating shaft 21 protruding from the body 8 is supported, and symmetrical cam grooves 22, 22' are formed in which the cam followers 20, 20 engage. The chuck pressing arm 15 is supported on a rotary shaft 23 projecting from the body 8 at an offset position. This chuck pressing arm 15 has an engaging piece 15a.
and an elastic pressure receiving piece 15b. Each elastic pressure receiving piece 15b of the chuck pressing arm 15 is connected to a pressing spring 2 disposed in a radial direction from the pivot shaft 2.
4 to press and rotate the pressing arm 15 around the rotating shaft 23 (FIGS. 3 and 7).

Further, the claw plate 17 has three biasing protrusions 17b and one stopper abutment 17c protruding toward the body 8, and each protrusion 17 is pushed by a biasing spring 25 housed in the transfer body 8. The claw plate 17 and the disk cam 11 are urged counterclockwise in FIG. 3 through the forceps (see also FIG. 8). The stopper abutment faces a stopper 26 that is adjustably fixed to the body 8.

Further, as shown in FIG. 6, the pivot shaft 18 has its base side and tip side eccentric by a dimension P, and by rotating and positioning it in the circumferential direction, the holding arm 1
2 and 12' can be adjusted.

In the device configured in this way, when the body 8 is in the retracted position, the connecting pin 1 is inserted into the groove 5b.
6 engages. In this state, the piston rod 3a
moves backward and the pawl body 5 rotates clockwise around the rotating shaft 4, the disc cam 11 and the pawl plate 17 release the spring 25, that is, the pawl plate 17
It rotates counterclockwise in the figure and stops when it hits the stopper 26. Due to this rotation, the pressing arm 15
Since the engaging piece 15a engages with the engaging recess 17a, it is pressed against the chuck C by the pressing spring 24. And the key 15c of the pressing arm 15
fits into the groove of the chuck C, fixing the chuck C in the circumferential direction and the front-rear direction (see FIG. 10).

Further, as the disk cam 11 rotates, the opening/closing cam 13 is rotated so that its cam follower 13a is connected to the notch 11a.
Since it is engaged with the rotation axis 21, it rotates around the rotation axis 21. As a result, the cam followers 20, 20 of the holding arms 12, 12' follow the cam grooves 22, 22,
Holding arms 12, 12' rotate around pivots 18, 18 and hold chuck C via holding portions 19, 19. Therefore, chuck C is the holding arm 1
It is gripped at three points by 2, 12' and the pressing arm 15.

When this clamping of the chuck C is completed, the transfer body 8 is moved forward by a forward and backward movement means (not shown), and the connection between the disc cam 11 and the cylinder 3 as an actuator is released. However, as can be seen from FIG. 3, since the opening/closing cam 13 and the pressing arms 12, 12' (or the cam follower 20 and the cam groove 22) are self-locked, the holding arms 12, 12 are Since the chuck C is still held and the disc cam 11 is clamped and fixed by the spring 25 and the stopper 26, the pressing arm 15 is also still in the pressed state. Therefore, even while the transfer body 8 moves forward and rotates in the circumferential direction, the chuck C is maintained in a clamped state.

On the other hand, it is desirable for the center position of the chuck held by the holding arm to coincide with the center of each main shaft of the chuck transfer device, but due to manufacturing errors, it is difficult to do so in practice. In other words, there is a slight distance difference between the pivot axis of the chuck transfer device and the respective main shaft axes. To correct this deviation, there is a method of repeatedly correcting the spacer by grinding the spacer in order to match the rotation axis and each spindle center, but there are disadvantages such as the need for a large amount of labor for the correction work. be.

In the present invention, the pivot shaft 18 holding the holding arm 12 is an eccentric shaft, and the eccentric dimension P of this pivot shaft 18 is
By changing the position of the chuck held by the holding arm, the position of the chuck can be matched with the position of each main shaft. That is, by sequentially adjusting the eccentric dimension P of the pivot shaft 18 of the holding arm with reference to the main shaft position of the longest distance between the turning axis and each main shaft, the axis of the chuck held by the chuck transfer device and each main shaft can be adjusted. Since the deviation from the axis can be minimized, simple and highly efficient correction work is now possible.

Further, misalignment between each chuck core clamped by the chuck transfer and each main shaft center can be absorbed by the deflection of the pressing spring of the pressing arm.

As described above, the present invention allows the pivot position of the chuck holding arm to be variably adjusted, and also allows the chuck pressing chuck to be compressed.
Misalignment between the centers of the plurality of clamped chucks and the centers of each main shaft can be easily matched.

[Brief explanation of the drawing]

Fig. 1 is a front view of the base portion of the device of the present invention, Fig. 2 is a front view of the disc cam and the pressing arm, and Fig. 3 is a front view of the base portion of the device of the present invention.
The figure is a partially cutaway front view with the transfer body and chuck holding arm also assembled, Figure 4 is a perspective view of the device of the present invention, and Figure 5 is a perspective view of the transfer body seen from different angles. , FIGS. 6 and 7 are longitudinal sectional views, FIGS. 8 and 9 are sectional views taken along the lines -- and -, respectively, and FIG. 10 is a sectional view showing the relationship between the pressing arm and the chuck. 1...Base, 2...Swivel axis, 3...Start cylinder,
8...Transfer body, 11...Disc cam, 1
2, 12'...Chuck holding arm, 13...Chuck holding arm opening/closing cam, 15...Chuck pressing arm, 17...claw plate, 18...pivot, 24...pressing spring.

Claims (1)

[Scope of Claims] 1. In a chuck changing device for an NC lathe, which holds and clamps a plurality of chucks and rotates them in the circumferential direction so that a chuck attached to a main shaft can be automatically replaced with another chuck, the chuck is supported on a base. A transfer body is rotatable in the circumferential direction, and a plurality of pairs of chuck holding arms and a plurality of chuck pressing arms are pivotally connected at fixed positions around the transfer body, and the chuck holding arms hold the chuck and The chuck is held at a predetermined position where it can engage with the main shaft of the main body, and the chuck pressing arm elastically presses the chuck and presses the chuck toward the holding arm, thereby holding the chuck holding arm and pushing the chuck. The pressing of the chucks is made to operate in conjunction with each other, and the pivot position of each of the chuck holding arms can be adjusted.
Chuck changing device for NC lathe.