JPS62208845A - Automatic tool exchanger - Google Patents

Abstract

PURPOSE:To increase speed of the tool exchange operation by providing an arm for gripping tools with two tool holding portions aligned in parallel and providing a cam for vertically moving the arm and a cam for horizontally moving the arm. CONSTITUTION:An arm 15 for tool exchange is provided in the vicinity of the extreme end thereof with two tool holding portions 22, 23 longitudinally aligned in parallel. The tool holding portions 22, 23 are semicircular, and are provided on the opening sides thereof with chuck pawls 22a, 23a for preventing falling-out thereof, respectively. A cam shaft 16 is rotatably supported by a frame 10 at a bearing portion 10a thereof. The cam shaft 16 is rotated by a motor 17 with a speed reducer mounted on the frame 10. Two cams 18, 19 are fitted on the cam shaft 16. The first cam 18 is in abutment at the outer periphery thereof against a cam follower 20 carried by the arm 15, and the second cam 19 is in abutment at the outer periphery thereof against a cam follower 21 carried by a slider 13.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an automatic tool changer that moves between a tool stocker and a main shaft of a machine tool such as a machining center to automatically change tools.

BACKGROUND ART Conventionally, this type of automatic tool changer has been designed to automatically change tools by vertical movement and rotational movement of an arm and by operation of a lock pawl of a tool holder provided on the arm. Usually, as a source of rotational motion of the arm,
Hydraulic and pneumatic cylinders are used.

However, in the hydraulic and pneumatic swing drive of the arm, it is difficult to increase the speed due to the centrifugal force of the arm and the rapid rotation and stopping of the arm. Further, since the above-mentioned turning motion exists, it is difficult to employ a cam drive. Furthermore, when the operating speed is increased, the reliability of operation during stoppages and the like decreases, and the tool change time has been limited to 5 to 6 seconds from tip to tip.

OBJECTS OF THE INVENTION Accordingly, an object of the present invention is to employ a cam drive in the above-mentioned automatic tool changer to increase the operating speed of tool change while making smooth changes, thereby shortening tool change time. The objective is to improve operational reliability and shorten tool change time, for example, to less than 5 seconds from tip to tip.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides two tool holding parts side by side at one end of an arm that grips a tool, a first cam that moves the arm up and down, and a first cam that moves the arm horizontally. By providing a second cam to cause the arm to move in a gate-like manner by rotation of these cams, the arm, which holds a tool in one tool holding part, is brought close to the main spindle, and then the main spindle is first moved. The tool held in the tool stocker is held in the other tool holding part, and then the tool held in one of the tool holding parts is placed in the spindle, and the tool is exchanged between the tool stocker and the spindle. I have to.

Embodiment Structure FIG. 1 schematically shows the overall structure in which an automatic tool changer 1 according to the present invention is incorporated into a machine tool, for example, a machining center 2. As shown in FIG.

The machining center 2 includes a base 3, a workpiece 4 fixed at a machining position, and an x-y
- A main shaft 5 that is movable in the z direction and rotationally driven by an appropriate means, and a known tool stocker 6 that holds a large number of tools and guides a selected tool to a tool loading/unloading position.
and an automatic tool changer 1 of the present invention configured as described below and provided between a spindle 5 and a tool magazine 6.

The automatic tool changer l of the present invention is constructed as shown in FIGS. 2 and 3.

That is, the frame 1o of the automatic tool changer 1 is held by a bearing 9 with respect to a support bracket 8 attached to a base 3 so as to be rotatable, for example, around a vertical axis 7. , and is rotationally driven by a motor 11 with a speed reducer fixed to one of the support brackets 8. The frame 10 is provided with two horizontal guide bars 12 at upper and lower positions of the frame 10. A slider 13 is slidably mounted along these guide bars 12 by upper and lower guide bushes 13a, and is urged rightward in the drawing by a spring 12a. A vertically extending guide bar 14 is attached to the slider 13, and an arm 15 for tool exchange, which will be described later, is supported so as to be slidable along the guide bar 14.

This arm 15 has a guide bush 15a at its base end.
is slidably supported by the guide bar 14 via the guide bar 14, is biased upward by a spring 14a, and is provided on the slider 13 with a rotation prevention protrusion 15b extending in the vertical direction for rotation prevention. , and is adapted to move in translation relative to the slider 13 in a non-rotating state. Furthermore, this arm 15 has two tool holders 22.2 arranged in parallel in the longitudinal direction near the tip.
It has 3. The tool holding parts 22 and 23 each have a semicircular arc shape, and each has chuck claws 22a and 23a on the opening side to prevent the tool from falling when the tool is being held. These operate in conjunction with tool gripping and release by known drive means.

On the other hand, the bearing of the camshaft 16 on the frame 10 side is rotatably supported by a portion 10a in the frame 10. This camshaft 16 is rotationally driven by a motor 17 with a reduction gear attached to the frame 10. Two cams 18, 19 are each mounted on the camshaft 16. The first cam 18 is in contact with a cam follower 20 provided on the arm 15 at its circumference, and the second cam 19 is in contact with a cam follower 20 provided on the arm 15.
similarly contacts the cam follower 21 provided on the slider 13 at its circumference. In this example, cam 18.1
As shown in FIGS. 4 and 5, the contours of No. 9 are approximately triangular and oval as a whole. Therefore, the cam follower 2° is always aligned with the cam 1 in accordance with the shape of the cam 18 by the spring 14a that urges the arm 15 upward.
The cam front 21 is always in contact with the cam 19 in accordance with the shape of the cam 19 due to the spring 12a that biases the slider 13 to the right, and is driven in the horizontal direction.

Effects of the Embodiment Next, the effects of the embodiment of the present invention constructed as described above will be explained with reference to FIGS. 6 to 16.

When the motor 17 rotates during a tool change, the cam 18.1
9 are slider 13 and arm 1 during one rotation, respectively.
5 is given linear reciprocating motion in an orthogonal direction on a vertical plane against springs 12a and 14a. At this time, the arm 15 moves along a motion trajectory as shown in FIG. 6 as a composite motion of the two linear reciprocating motions. In addition, in the figure, ■ to ■ indicate rotational phases in relation to the circumferential curves of the cams 18 and 19.

°A pivoting movement of the arm 15 by the frame 10 is added to this movement. This turning movement is caused by the -■ part of the cam 18.19.
part, and during the period of movement from part (■) to part (■).

Next, the actual tool exchange operation will be explained step by step with reference to FIGS. 7 to 16.

First, the cam followers 20.21 are connected to the cams 18.1 and 18.1, respectively.
In the state in which the arm 15 is in contact with the 0 portion of the tool 9, the arm 15 is holding the next tool A from the tool stocker 6 in the tool holding portion 23, and is in the raised position and has moved to the first position. In this state, the movement of the spindle 5 causes the used tool B attached to the spindle 5 to fit into the tool holding portion 22 of the arm 15 (see FIG. 7).

Next, when the motor 17 rotates the cam 18.19 and the cam follower 20.21 comes into contact with the part 2 of the cam 18.19, the arm 15 moves to the lowered position while remaining in the first position. The used tool B is thus pulled out from the spindle 5, held by the tool holding portion 22 of the arm 15, and is prevented from being pulled out by the chuck claw 22a (see FIG. 8).

Furthermore, when the motor 17 rotates the cam 18.19 and the cam followers 20, 21 come into contact with the 0 portion of the cam 18.19, the arm 15 moves to the second position while remaining in the lowered position. In this way, a new tool A is attached to the spindle 5.
(see Figure 9).

Then, cam follower 20.21 is 0 of cam 18.19.
When the arm 15 comes into contact with the second position, the arm 15 moves to the raised position while remaining in the second position. The tool A is thus fitted into the spindle 5 and held therein (see Figure 10).
. Here, the main spindle 5 moves to the machining position indicated by the chain line as indicated by the arrow in FIG. 11, and prepares for machining the workpiece 4 with the tool A.

Next, when the motor 11 rotates the frame 10 by, for example, 180 degrees in the direction of the arrow in FIG. 11, the arm 15 moves to the area of the tool loading/unloading position of the tool/car 6 and stops. Thereafter, when the cam follower 20.21 comes into contact with the 0 part of the cam 18.19 due to the rotation of the cam 18.19, the arm 15 moves to the first position while being in the lowered position. Then, the used tool B is guided to the tool loading/unloading position of the tool stocker 6 (see FIG. 12).

Then, the cam followers 20 and 21 move to 0 of the cam 18 and 19.
When the arm 15 comes into contact with the first position, the arm 15 moves to the raised position. In this way, the used tool B is inserted into the tool loading/unloading position of the tool stocker 6 (first
(See Figure 3). Here, the motor 11 moves the frame 10 to the first
The arm 15 is retracted from the tool stocker 6 by rotating it by an appropriate angle in the direction of the arrow in FIG. 4, for example, counterclockwise.

Thereafter, the tool stocker 6 is driven to index the next tool C to be used. By this indexing operation, the next tool C to be used is guided to the tool loading/unloading position of the tool stocker 6.

Then, cam follower 20.21 is 0 of cam 18.19.
When the cam follower 21 comes into contact with the arm 15, the cam follower 21 moves the arm 15 to the second position. From this state, motor 1
1 rotates the frame 10 clockwise and moves the arm 15 again to the tool loading/unloading position area of the tool stocker 6, the next tool C to be used fits into the tool holding portion 23 of the arm 15 (15th (see figure).

Next, when the cam follower 20.21 comes into contact with the 0 part of the cam 18.19, the cam follower 20
5 to the lowered position. Thus, the next tool C to be used
is pulled out from the tool loading/unloading position of the tool stocker 6 and held by the tool holding portion 23 (see FIG. 16).

Finally, the motor 11 rotates the frame 10 in the direction opposite to the arrow in FIG. When it comes into contact with the 0 part of the cam 18, 19, the arm 15 moves into the first position in the raised position and prepares for the next exchange operation.

By repeating the above operations, predetermined necessary tools are sequentially replaced and mounted on the main spindle 5.

According to the embodiment configured in this way, the tool replacement time is expected to be approximately 4.75 seconds for the tip, toe, and knob, and by increasing the rotational speed of the cam and adopting a transition curve. , for example, a tool change time of about 4.35 seconds is also possible.

Modification of the Invention As a modification of the embodiment described above, the cam 18.1
9 may be a positive cam. In this case, the tool change is
This is done at higher operating speeds and with greater reliability. Further, the locking of the chuck jaws and the clamping of the pull stand can also be performed by cam drive.

Effects of the Invention As described above, according to the present invention, two tool holding parts are provided side by side on an arm that grips a tool, a first cam that moves the arm up and down, and a second cam that moves the arm horizontally. is installed, and the tool is exchanged by the gate-type movement of the arm, so compared to the conventional automatic tool changer driven by hydraulic and pneumatic drive, the tool change on the main shaft is performed by linear motion and cam drive. , it becomes possible to increase the operation speed of tool exchange, and the reliability of tool exchange operation can also be improved.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing a machining center incorporating an automatic tool changer according to the present invention, Fig. 2 is a side view showing an embodiment of the automatic tool changer, and Fig. 3 is a cross-sectional view of the embodiment of Fig. 2. The top view, Figures 4 and 5 show the first arm drive
FIG. 6 is a locus diagram of the arm, and FIGS. 7 to 16 are explanatory diagrams of the arm replacement operation. 1. Automatic tool changer, 2. Machining center,
4. Workpiece, 5. Spindle, 6. Tool stocker,
7...Axis, 10...Frame, 11...Motor, 13
...Slider, 15...Arm, 16...Camshaft, 17
...Motor, 18.°first cam, 19..second cam, 22.23.tool holder. Figure 7 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 10 Figure 77 Figure 73 Figure 9 to 74 Figure 9 Figure 12 Figure 75

Claims (1)

[Claims] In a device that automatically exchanges tools by moving between a tool stocker and a spindle, an arm that grips a tool is provided with two tool holding parts side by side, and a first part that moves the arm up and down is provided.
An automatic tool changer comprising: a cam; and a second cam for horizontally moving the arm, and tools are exchanged by gate-like movement of the arm.