KR20020059111A - automatic tool quick changer for machining center - Google Patents

Abstract

PURPOSE: A high speed tool exchange device for a machining center is provided to reduce number of components and to obtain high speedy operation by installing a link to be close to a cam surface by a pretensioned spring and setting inclination angle of a cam more gently. CONSTITUTION: A high speed tool exchange device for a machining center comprises a cam(44), a link(50), a pretensioned spring(70), a first cam follower(80), a second cam follower(82), and a home switch(LS10). The cam forwardly and backwardly moves a changer arm(42) rotated by a roller gear cam. The link is supported by a hinge pin(52) as to rotate at a body(60). The pretensioned spring is connected to the link at its one end and is connected to the body at its other end so that the link being in contact with a cam surface(44f). The first cam follower is installed to middle of the link to be in contact with the cam surface to be rolled. The second cam follower moves a shaft(46) forwardly and backwardly by angular movement of the link.

Description

Automatic tool changer for machining centers {automatic tool quick changer for machining center}

The present invention relates to a high-speed automatic tool changer used to automatically change a tool in a machining center, and more particularly, by using a preload spring, the cam follower on the link is always in contact with the cam surface, so that the cam track is a single link. And the cam switch is configured to finish one cycle when the cam is rotated one time, making the cam curve more gentle, reducing the load resistance and at least detecting the starting position of the rotation. When provided, the present invention relates to a high speed automatic tool changer of a machining center capable of motion detection.

In general, alternatives for improving the productivity of machining in machine tools can be divided into shortening cutting time and non-cutting time.

Among these methods, a shorter cutting time can be achieved by improving the feed rate of the feed system, shortening the tool change time by the ATC, or shortening the workpiece change time by the auto pallet changer (APC). It is broken down again.

Such automatic tool changer uses a roller gear cam that is suitable for straight tool and rotational movement.

However, the conventional automatic tool changer is configured to convert rotational motion into linear motion while two links 20 and 22 are simultaneously angularly moved by the cam 30 as shown in the accompanying drawings. The two links 20 and 22 were configured to interlock through the link 24.

However, since the conventional automatic tool changer uses a plurality of links 20, 22 and 24, hinge pins 25 and 26 for supporting the links 20, 22 and 24. And the ends of the cam follower 32 and the connecting pins 34 that accumulate errors and become linear errors. Therefore, when the tool is mounted on the spindle by the changer arm 36, the contact portion between the tool and the spindle There was a problem in that the collision occurs in the stomach damage the tool mounting portion of the spindle.

In addition, as shown in Figure 3, when the roller gear cam is rotated, the swing angles (a, b: tool change) are changed by 48 °, respectively, when tool change of the changer arm 36, which has rotational motion and linear motion, is made. Rotational operation section), the angle on the cam curve corresponding to 180 ° rotation of the actual changer arm 36 is 130 °.

This means that if all the tool changes must be performed within 1 second, a large torque resistance is generated and a large load is applied to the geared motor, the drive system, and the cam, and this operation accumulates and the life of the machine is reduced. Due to the large maneuvering load, acceleration performance is difficult, and thus there is a problem in that it is difficult to speed up.

That is, since the swing angle section formed on the cam 30 makes steep inclination, the load resistance is increased, and acceleration is difficult.

In addition, the conventional automatic tool changer is configured to complete one cycle at 360 ° rotation of the cam, and the swing angle (a) (b) is divided into half before and after the tool change cycle. Tool unclamp switch (LS2) for detecting the clamp operation of the tool after the changer arm 36 is retracted and the changer arm 36 is moved, in addition to the groove switch LS1 for detecting the start position when the start is started. ) And a tool clamp switch (LS3), there is a problem that adds to the complexity of the machine.

The present invention has been made to solve the above problems, the object of which is to simplify the machine by reducing the number of links for converting the rotary motion into a linear reciprocating motion, and to make the slope of the cam curve more gentle initial starting load It is possible to reduce the acceleration performance and tool change time by reducing, and to provide a high speed automatic tool changer of the machining center which can make tool change faster by eliminating the swing angle on the cam curve.

In order to achieve the object of the present invention, the cam having a cam curve cycle for retracting and advancing the changer arm repeatedly by interlocking at the starting and end portions of the changer arm which rotates by the roller gear cam at each rotation, A link supported by the hinge pin to be rotated in the main body, one end is connected to the link, the other end is fixed to the main body, and a preload spring is applied to the pre-load so that the link always comes in contact with the cam face, and the cam face is installed in the middle of the link. A first cam follower which is rolled in contact with the second cam follower, and a second cam follower which is installed at the end of the link and is coupled to a groove on the shaft connected to the changer arm to advance / retract the shaft in a linear direction in the angular motion of the link, It is installed in the main body has a feature consisting of a home switch for detecting the origin of the cam.

1 is a plan view showing the configuration of a conventional automatic tool changer

Figure 2 is a front view showing the configuration of a conventional automatic tool changer

3 is a cam diagram for explaining the operation of the conventional changer arm.

4 is a plan view showing the configuration of an automatic tool changer according to the present invention;

5 is a front view showing the configuration of an automatic tool changer according to the present invention;

6 is a cam diagram for explaining the operation of the changer arm according to the present invention;

* Explanation of Signs of Major Parts of Drawings *

42: changer arm 44: cam

52: hinge pin 60: main body

50: link 44f: cam surface

70: preload spring 80: the first cam followers

46: shaft 46a: groove

82: second cam follower LS10: home switch

90: Preload adjusting bolt 92: Lock nut

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIGS. 4 and 5, the cam 44 is interlocked at the beginning and the end of the rotation of the changer arm 42 which is rotated by the roller gear cam every time it is rotated. ) Is configured to have a cam curve cycle that allows it to be retracted / advanced repeatedly.

Thus, one rotation of the cam 44 is detected by the switch dog 100 formed in the cam 44 and the home switch LS10 provided in the main body 60.

That is, as shown in FIG. 6, the swing angle as in the prior art is excluded, and the tilt angle of the cam surface 44f is greatly reduced by, for example, increasing the use angle to 250 °.

On the other hand, the link 50 is composed of one, it is rotatably installed on the main body 60 by a hinge pin 52, the other end is fixed to the main body 60, one end to the link 50 The first cam follower 80 provided in the middle of the link 50 is connected to the cam surface 44f by the preload spring 70 connected thereto.

In addition, the preload spring 70 may be composed of, for example, a tension spring.

Then, the preload spring 70 as described above is fixed to the end of the preload adjustment bolt 90 is screwed to the main body 60, the preload spring 70 is stretched by rotating the preload adjustment bolt 90 The preload was configured to be adjusted to a proper line, and the lock nut 92 was screwed to the preload adjusting bolt 90 to prevent the preload adjusting bolt 90 from loosening after the preload adjustment.

At the end of the preload adjustment bolt 90 may be composed of a rotatable joint to prevent rotation with the preload spring (70).

Further, a second cam follower 82 is installed at the end of the link 50, and the second cam follower 82 is cloud-coupled to the groove 46a on the shaft 46 connected to the changer arm 42. When the link 50 is angularly moved so that the shaft 46 can be moved forward or backward in a linear direction.

In the figure, reference numeral 120 denotes a geared motor.

Hereinafter, the operation according to the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIGS. 4 and 5, when a command for exchanging a tool mounted on the spindle is issued from the control device, a signal for unclamping the tool is generated, wherein the geared motor 120 is rotated. Cam 44 is rotated.

In this process, the shaft 46 supporting the changer arm 42 is rotated and reversed by 180 ° as shown in FIG. 6, and is axially reversed by the link 50 at the start and end of the rotational motion, respectively. And forward movement.

That is, when the cam 44 makes one rotation, the link 50 is angularly moved at a predetermined angle in conjunction with the cam 44. At this time, the second cam follower 82 makes a cloud coupling to the end of the link 50. The linear shaft 46 and the changer arm 42 are pushed back and forth by the link 50.

When the cam 44 is rotated one time as described above, the origin of the switch dog 100 formed on the cam 44 approaches the home switch LS10 provided in the main body 60.

On the other hand, when adjusting the preload that the link 50 has by adjusting the tension force of the preload spring 70, first, when the preload adjusting bolt 90 is turned in the forward or reverse direction with the lock nut 92 loosened When one end of the tension spring, which is the preload spring 70, is pulled or loosened, the preload is finely adjusted, and when the lock nut 92 is tightened to maintain the adjusted preload, the preload adjusting bolt 90 is the main body 60. Is fixed to.

In the present invention as described above, since the link moving by the cam is always installed in close contact with the cam surface by the preload spring, it is possible to configure a single link so that the number of components can be reduced and the cam rotates once. At this time, since one cycle of tool change is completed, it can be operated only by the home switch for detecting the origin of the cam.In particular, since the cam angle is increased and the cam inclination is set to be gentle, The load is reduced, and at the same time, the acceleration is increased to enable high speed, and the load on the geared motor or the cam mechanism is reduced according to the high speed, so that the operation is smoothed.

Claims (2)

A cam 44 which retracts / advances the changer arm 42 which rotates by the roller gear cam; A link 50 supported by the hinge pin 52 to rotate in the main body 60; One end is connected to the link 50, the other end is fixed to the main body 60, the preload spring 70 for applying a preload so that the link 50 is always in contact with the cam surface (44f); A first cam follower 80 installed in the middle of the link 50 to be in contact with the cam surface 44f and rolling; A second cam follower 82 installed at an end of the link 50 to be cloud-coupled to the shaft 46 connected to the changer arm 42 to advance / retract the shaft 46 by the angular movement of the link 50; The high speed automatic tool changer of the machining center, which is installed in the main body (60) and comprises a groove switch (LS10) for detecting the origin of the cam (44). The high speed automatic tool changer of a machining center according to claim 1, further comprising a preload adjusting bolt (90) for adjusting the preload of the preload spring (70), and a lock nut (92).