JPS6347578B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an automatic tool changer for a machine tool,
In particular, the present invention relates to an improvement in an automatic tool changer that indexes and rotates a tool magazine storing a plurality of tools for automatic tool change by rotation of the main shaft of a machine tool.

In machine tools equipped with automatic tool changers,
Various methods have been adopted for automatic tool change. One example of an automatic tool changer that indexes and rotates the tool magazine by rotating the machine spindle is a spindle head that can rotate and move up and down, as shown in Figure 1. 10 and this spindle head 10
A tool magazine 16 is provided with a magazine body 14 that is rotatable around a magazine shaft 12 having an axis inclined in a direction relative to the upper and lower axes. The spindle head 10 can be moved up and down relative to the tool magazine 16 by the provided slide mechanism 18, and one end of the spring is fixed to the top of a bracket 10a that is integrally fixed to the spindle head 10. The other end of the tool magazine 20 is locked to the tool magazine 16. A bevel gear 24 that rotates integrally with the main shaft 22 is provided at the lower end of the main spindle head 10 and is concentric with a tool receiving hole (not shown) formed at the lower end of the main shaft 22. A bevel gear 26 that can mesh with the gear is provided. Further, in the main body 14 of the tool magazine 16, a plurality of tools T are rotatably received by rotary bearings 28, and when any tool T is indexed to the lowest position of the spindle head 10, The tool can be inserted into the tool receiving hole of the main spindle 22. FIG. 1 shows a state in which one tool T stored in the magazine body 14 of the tool magazine 16 is inserted into the tool receiving hole of the spindle 22 in the spindle head 10. descends with the tool magazine 16, the machining position is reached, and the spindle 2
2 is rotatably received in the magazine body 14, and the tool T inserted into the lower end of the main shaft 22 is driven to rotate to perform machining operations. On the other hand, move the spindle head 1 from the position shown in FIG.
0 rises with the tool magazine 16, and the tool magazine 16 is attached to the stopper 30 attached to the machine body.
From the moment when the spindle head 10 comes into contact with the slide mechanism 1
8 further rises relative to the tool magazine 16, the tool T received in the magazine main body 14 is detached from the tool receiving hole of the main spindle 22, and at this time, the main spindle head 10 is attached to the bevel gear 26 of the magazine main body 14.
The bevel gears 24 reach an engaged state. Therefore, by rotating the spindle 22 of the spindle head 10 over a desired angle with the spindle motor, the magazine body 14 is indexed to a position directly below the spindle 22 through the engagement of the bevel gears 24 and 26. It can be rotated to In this way, when the spindle head 10 descends after the indexing of the next tool T is completed, the engagement of the bevel gears 24 and 26 is released and the spindle 2 is moved again.
The next tool T of the tool magazine 16 is inserted into the tool receiving hole No. 2, and the automatic tool exchange is completed.
After this, if the spindle head 10 and the tool magazine 16 are brought together again and lowered to the machining position, machining can be resumed using the new tool T that has been replaced. However, in the automatic tool changer configured as described above, a pair of bevel gears 24 and 26 are used to rotate the tool magazine 16 by the rotation of the main shaft 22, and the tool T is inserted into the tool receiving hole of the main shaft 22. In order to attach and detach, it is necessary to engage and disengage the pair of bevel gears 24 and 26. Therefore, when assembling the automatic tool changer, when indexing and mounting any of the plurality of tools stored in the tool magazine 16 onto the spindle 22, the spindle head 1
A method is adopted in which the bevel gear 24 of the tool magazine 16 and the bevel gear 26 of the tool magazine 16 are adjusted and assembled in advance so that they always mesh and disengage smoothly. In this case, the machine tool is equipped with a so-called orientation function in which the spindle 22 of the spindle head 10 stops at a certain angular position when it receives a certain command signal, and the main spindle 22 stops at the above-mentioned certain angular position. The bevel gear 24 of the main shaft and the bevel gear 26 of the tool magazine are adjusted so that they mesh and disengage smoothly. Further, during the adjustment and assembly of both bevel gears 24 and 26, adjustment using a jig must be performed so that each tool receiving center of the magazine body 14 is concentric with the center of the tool receiving hole of the main shaft 22. Therefore, such adjustment and assembly is a cumbersome operation, which is a factor that hinders the productivity of the automatic tool changer, and also causes an increase in production costs.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an automatic tool changer that does not use a gear mechanism to drive indexing rotation of a magazine body by rotation of a main shaft, in order to eliminate the above-mentioned problems. be.

That is, according to the present invention, the tools in the tool magazine are indexed directly below the spindle by rotating the tool magazine by the rotation of the spindle in the spindle head,
and an automatic tool changer for a machine tool that attaches and detaches a tool to the spindle by moving the spindle head up and down relative to the tool magazine, a first rotating body that rotates integrally with the spindle of the spindle head; , a second rotary body that rotates integrally with the tool magazine is provided, and the spindle head is placed upwardly with respect to the tool magazine.
When the tool magazine moves downward and reaches a fixed position where the first and second rotating bodies come into contact with each other, the first and second rotating bodies form a pair of friction transmission wheels; An automatic tool changer for a machine tool is provided, characterized in that a rotation amount detection means is provided in the tool magazine. Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 2 is a mechanical diagram of main parts showing an embodiment of an automatic tool changer for a machine tool according to the present invention, and the same reference numerals as in FIG. 1 in this figure indicate the same functional elements or the same functional parts.

Now, in the embodiment shown in FIG. 2, a main shaft wheel 34 having a conical peripheral surface 34a is provided at the lower end of the main shaft head 10 to form a first rotating body, and this main shaft wheel 34 rotates the main shaft 22. Therefore, it is mounted coaxially with the main shaft 22 at the lower end of the extension of the main shaft. The conical peripheral surface 34a of the main shaft wheel 34 may be adhesively coated with or coated with a suitable high-friction resin material on a metal base so that the conical peripheral surface 34a has a relatively high coefficient of friction. Alternatively, the main shaft wheel 34 may be machined using a metal material, and only the conical peripheral surface 34a may be roughened to have a high coefficient of friction.

On the other hand, the magazine body 14 of the tool magazine 16a
A magazine wheel 36 is rotatably attached to the magazine shaft 12 via a rotation bearing 32 and is fixed to the bearing box 14a of the magazine body 14.
forms a second rotating body having a conical peripheral surface 36a. The conical circumferential surface 36a of this magazine wheel 36 also has a structure similar to that of the first rotating body described above so as to have a relatively high coefficient of friction. The conical peripheral surface 36a of the magazine wheel 36 allows the spindle head 10 to slide into the sliding mechanism 18 with respect to the tool magazine 16.
2, the conical peripheral surface 34a of the main shaft wheel 34 moves up and down relative to the
It is formed so as to be in surface contact engagement with the main shaft head 10 and to be able to transmit rotational force from the spindle head 10 to the magazine body 14 when the two are in surface contact with each other. In other words,
According to the present invention, unlike the pair of bevel gears 24 and 26 in the conventional automatic tool changer shown in FIG.
A configuration is adopted in which rotational force is transmitted from the main shaft 22 of the main spindle head 10 to the magazine body 14 of the tool magazine 16 using a pair of friction wheels (first and second rotating bodies). Therefore, in the case of this pair of friction wheels, unlike the meshing engagement of the teeth of the bevel gears 24 and 26, the conical circumferential surface 34a of the main shaft wheel 34 and the conical circumferential surface 36a of the magazine wheel 36 engage in surface contact engagement. As soon as the position is reached, the transmission of rotational force can begin.
However, in order to position and index each tool T of the magazine body 14 directly below the main shaft 22, a configuration for detecting the amount of rotation of the magazine body 14 is required. For this purpose, in this embodiment, a toothed wheel 38 is attached to the outer periphery of the bearing box 14a of the magazine body 14, and a toothed belt 40 engaged with this toothed wheel 38 is attached to the input shaft of a position coder 42. toothed wheel 44
The position coder 42 itself is fixedly attached to an arm plate 46 fixed to the magazine shaft 12. Therefore, the amount of rotation of the magazine body 14 is determined by the rotation amount of the toothed wheel 38, the toothed belt 40, and the toothed wheel 44.
It is configured to be detected by the position coder 42 via a rotation transmission mechanism consisting of the following.
According to the rotation amount of the magazine body 14 detected by the position coder 42, the rotation amount of the spindle 22 of the spindle head 10 is controlled by a control device (for example, an NC machine tool).
If controlled by a control device), the magazine body 1
The four tools T can be controlled so as to reach directly below the spindle 22. In other words, it is possible to easily replace the used tool T in the magazine body 14 with another new tool T. Note that instead of the above-described configuration using the rotation transmission mechanism consisting of the toothed wheels 38, 44 and the toothed belt 40 and the position coder 42, the amount of rotation of the magazine body 14 is detected by using a well-known resolver element or the like. It is also possible. According to the automatic tool changer of the present invention having the above-described configuration, since a friction transmission mechanism consisting of a pair of main shaft wheels 34 and a magazine wheel 36 is used, adjustment and assembly work required for assembling a conventional bevel gear is required. The problem is significantly reduced, and it is only necessary to perform some adjustment work so that the conical circumferential surface 34a of the main shaft wheel 34 and the conical circumferential surface 36a of the magazine wheel 36 are brought into accurate surface contact engagement. Furthermore, if a friction transmission mechanism is used, there is no need for the machine tool itself to have an orientation function that stops the spindle 22 of the spindle head 10 at a fixed angular position, and therefore the machine's ability for automatic tool change is improved. Since it can be simplified, it can also contribute to cost reduction. In addition, in the conventional system using bevel gears, a special gear cutting machine is used to cut the bevel gears, and a long machining time is required, which tends to increase the cost of the components of the automatic tool changer. According to the friction transmission mechanism, the main shaft wheel 34 and the magazine wheel 36 can be machined by simple machining, which also contributes to cost reduction.

[Brief explanation of the drawing]

FIG. 1 is a mechanical diagram showing the configuration of a conventional main part of an automatic tool changer for a machine tool, and FIG. 2 is a mechanical diagram showing the main part structure of an embodiment of the present invention in the same automatic tool changer. 10... Spindle head, 12... Magazine shaft, 14...
...Magazine body, 16...Tool magazine, 18...
...Slide mechanism, 22... Main shaft, 34... Main shaft wheel, 34a... Conical peripheral surface, 36... Magazine wheel,
36a...Conical peripheral surface, 38...Toothed wheel, 40...Toothed belt, 44...Toothed wheel, 42...Position coder, T...Tool.

Claims (1)

[Claims] 1. By rotating the tool magazine by rotating the spindle in the spindle head, the tools in the tool magazine are indexed directly below the spindle, and the tools in the tool magazine are indexed directly below the spindle, and the spindle head is moved up and down relative to the tool magazine. An automatic tool changer for a machine tool that attaches and detaches a tool to a main spindle by moving the tool, comprising: a first rotating body that rotates integrally with the main axis of the spindle head; and a second rotating body that rotates integrally with the tool magazine. , when the spindle head moves up and down with respect to the tool magazine and reaches a fixed position where the first and second rotating bodies come into contact, a pair of An automatic tool changing device for a machine tool, characterized in that a friction transmission wheel is formed and a rotation amount detecting means for the tool magazine is provided in the tool magazine. 2. The automatic tool changer for a machine tool according to claim 1, wherein the rotation amount detection means comprises a position coder.