JPH054144A - Pallet moving device - Google Patents

Abstract

PURPOSE:To lessen the floor area for installation and perform locational control easily by arranging the rotational axis of a cylindrical cam in parallel with the working direction of a guide device, and detaining a follower piece of a pallet with a cam groove. CONSTITUTION:A pallet moving device concerned is composed with a guide device, a pallet 11 on which a follower piece detained with the guide device is placed, a cylindrical cam 8 provided at the periphery with a cam groove 9 stretching in the axial direction, and a drive device for the cylindrical cam 8. The rotational axis of this cylindrical cam 8 is arranged so as to be parallel with the working direction of the guide device, and the follower piece is detained with the cam groove 9. At the two ends of this cam groove 9 a groove is formed stretching perpendicularly to the rotational axis. Thereby the motion characteristics for moving the pallet are made controllable with the shape of the cam groove 9. This facilitates control of the drive device, and also facilitates stopping of the cylindrical cam 8 owing to provision of the grooves in the mentioned places in the mentioned fashion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pallet moving device for placing a work on a machining center or the like.

[0002]

2. Description of the Related Art In order to increase the processing time, it is necessary to shorten the pallet exchange time. Therefore, for example, in Japanese Patent Laid-Open No. 63-207535, a transmission device connected to one of the table itself and a means for driving the table to output a rotational motion, and a linear movement of the table connected to the transmission device. A technique having a speed increasing device that transmits a linear motion of a higher speed and a larger stroke to a pallet is disclosed.
In the above technology, the mechanism is simplified compared to the conventional one, and the movement of the pallet and the table are synchronized,
The pallet exchange time could be shortened.

[0003]

However, in the above technique, the radius of the arm increases as the moving distance of the pallet increases, so that the installation floor area must be increased. An object of the present invention is to solve the above-mentioned problems and to provide a pallet moving device that can reduce the installation floor area and easily perform positioning control.

[0004]

SUMMARY OF THE INVENTION The above-mentioned problems include a guide device, a pallet that engages with the guide device and mounts a follower,
A cylindrical cam having a cam groove formed in the axial direction on the outer periphery and a driving device for the cylindrical cam are provided, the rotation axis of the cylindrical cam is arranged parallel to the guide direction of the guide device, and the follower of the pallet is engaged with the cam groove. It is solved by combining them. Furthermore, if grooves are formed at both ends of the cam groove in the direction perpendicular to the axis of rotation,
More effectively resolved.

[0005]

Since the follower of the pallet is engaged with the cam groove, the movement characteristic when moving the pallet can be controlled by the shape of the cam groove of the cylindrical cam. Therefore, control of the drive device becomes easy. Further, since the grooves in the direction perpendicular to the rotation axis are formed at both ends of the cam groove, the stop control of the cylindrical cam can be facilitated.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will be given below with reference to FIGS. Figure 1
Is a front view of a machining center to which the present invention is applied, FIG. 2 is a plan view, and FIG. 3 is a side view. In the figure, 1 is a bed. A table 2 is movable in the X direction on the bed 1 by a driving means (not shown). A column 3 is movable on the bed 1 in the Y direction. A spindle head 4 is movable on the column 3 in the Z direction. 5 is a spindle for holding a tool. 6 is a motor. A gear box 7 is mounted on the table 2 and transmits the rotation of the motor 6 to the cylindrical cam 8. A cam groove 9 is provided on the outer circumference of the cylindrical cam 8 in the axial direction, and the axis of rotation is in the X direction. As shown in FIG. 4, the expansion curve of the cam groove 9 is a linear area C perpendicular to the axis of rotation, a curved area D that is a part of a sine curve, and a linear area parallel to the area C. It is composed of area e. Also,
In the figure and FIG. 2, a is a machining position and b is an exchange position.

FIG. 5 is a sectional view taken along line I--I in FIG. 1, that is, an end sectional view of the cylindrical cam 8. 10 is a cylindrical cam 8
It is fixed to the table 2 by a bracket that rotatably supports the. A pallet 11 is movable in the X direction on a track 12 fixed to the table 2. A roller support 13 is fixed to the end of the pallet 11. A roller 14 is engaged with the cam groove 9. 15 is a frame fixed to the bed 1. A pallet exchange table 16 is movable on the frame 15 in the Y direction. The pallet exchange table 16
Two tracks 17 and 18 are provided on the pallet, and two pallets, that is, the pallet 11 and the pallet 19 can be placed. The operation from the state of FIG. 1, that is, when the machining of the workpiece (not shown) fixed to the pallet 11 is just finished and the spindle 5 returns to the standby position will be described below. The roller 14 is assumed to be at the midpoint A of the area C in FIG. Further, both ends of the area D are referred to as points B and C, and the middle point of the area E is referred to as a point D.
Further, the distance between the points B and C, that is, the distance between the machining position and the exchange position is L.

The motor 7 is driven to rotate the cylindrical cam 8, that is, the cam groove 9. When the cam groove 9 rotates, the roller 14 that engages with the cam groove 9, that is, the pallet 11, moves as follows. (1) Between A and B: Stop at position a. (2) Between B and C: Move along a sine curve. Ie point B
Is gradually accelerated. Then, after reaching the maximum speed at the position of L / 2, the speed is gradually reduced and the vehicle stops at point C. (3) Between C and D: Stop. (The position of the pallet 11 is shown by a chain double-dashed line in FIG. 2.) Then, when the roller 14 reaches the position of the midpoint D, the motor 6 is moved.
To stop the rotation of. Since the track 17 is pre-aligned with the track 12, the pallet 11 moves smoothly to the track 17. Since the cam groove 9 is at a right angle to the rotation axis near the midpoint D, the roller 14 can be moved in the Y direction as shown in FIG. Then, the pallet exchange table 16 is continuously moved in the Y direction to align the track 18 with the track 12. When the motor 6 is rotated in the opposite direction to the above, the pallet 19 moves in the opposite direction. When the roller 14 reaches the midpoint A, the motor 6
To stop. Thereafter, this operation is repeated to position the pallet 11 or the pallet 19 with respect to the machining position, that is, the spindle 5.

In this embodiment, the pallet 11
The motor 6 was stopped at the midpoint D when moving the
It is sufficient that the roller 14 can be separated from the cam groove 9 as shown in FIG. Similarly, it goes without saying that the motor 6 may be stopped immediately when the roller 14 crosses the point B when positioning the pallet 19 on the table 2. Further, although the cam groove 9 has a sine curve in the present embodiment,
Not limited to this, a trapezoidal curve or the like can be arbitrarily selected. Further, in the present embodiment, the cylindrical cam is placed on the table 2 in order to facilitate the positioning to the processing position and the structure, but it may be placed on the bed 1.

[0010]

As described in detail above, according to the present invention,
The floor area hardly changes regardless of the moving distance of the pallet, and the positioning can be easily controlled by the grooves provided at both ends of the cam groove in the direction perpendicular to the rotation axis. Further, there is an effect that the acceleration / deceleration characteristics when moving the pallet can be made appropriate by selecting the shape of the cam groove.

[Brief description of drawings]

FIG. 1 is a front view of a machining center to which the present invention is applied.

FIG. 2 is a plan view of FIG.

FIG. 3 is a side view of FIG.

FIG. 4 is a development curve of a cam groove.

5 is a cross-sectional view taken along line I-I of FIG.

[Explanation of symbols]

6: Motor 8: Cylindrical cam 9: Cam groove 11, 19: Palette 12, 17, 18: Orbit 13: Roller support 14: Laura

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koichi Sato             2100 Kamiimaizumi Stock Association, Ebina City, Kanagawa Prefecture             Inside Hitachi Seiko Pretec

Claims (2)

[Claims] 1. A cylindrical cam comprising: a guide device; a pallet that engages with the guide device and mounts a follower; a cylindrical cam having a cam groove formed in an outer peripheral axial direction; and a cylindrical cam drive device. A pallet moving device characterized in that a rotary shaft center is arranged parallel to a guide direction of a guide device and a follower of the pallet is engaged with a cam groove. 2. The pallet moving device according to claim 1, wherein grooves are formed at both ends of the cam groove in a direction perpendicular to the axis of rotation.