JP2722404B2 - Spindle moving type automatic lathe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a spindle moving type automatic lathe.

[Conventional technology]

Spindle-moving lathes are roughly classified into cam-type automatic lathes and NC-type automatic lathes according to their control forms.

In the case of the cam type, the selection and cutting of the blade, the movement of the spindle, and other operations are all performed by the cam. The cam has a unique shape on the camshaft as many as the number of
It is provided in the range of 0 °. Therefore, since it has a quick response and a short processing cycle, it is suitable for processing a product having a relatively simple shape and which can be processed in a short time, and is particularly suitable for high-volume production processing. It is also highly reliable.

For example, such a cam type is described on page 48 of an automatic lathe handbook (Industrial Research Institute Co., Ltd., issued on September 30, 1968). In this method, the driving force of one motor rotates the main shaft, and also rotates the camshaft via the transmission to select and cut the blade.
Each operation such as feed during cutting is also performed by each cam on the cam shaft.

In the case of the NC type, the above various operations are performed by independent driving elements according to a program. Therefore, by changing the program, it is possible to freely cope with a change in the shape of the product. For example, Japanese Patent Publication No. 60-59763 discloses an example in which the selection of a cutting tool is made by an NC.
In this known device, a plurality of tool rests are arranged radially with respect to the main shaft, and each of the tool rests can freely move toward and away from the main shaft by a cylinder attached thereto. To select a tool, a predetermined cylinder is driven by a signal from the NC to drive one tool post toward the main spindle to bring it to a processing position, and the other tool post is maintained at a retracted standby position.

Next, in Japanese Utility Model Application Laid-Open No. 63-103901, a selection mechanism consisting of a cylinder is provided for each of the connecting rods and swivel arms for cutting provided on each of a plurality of tool rests, and a selection mechanism comprising a cylinder is provided. A predetermined cylinder is operated to select a corresponding tool rest. In addition, Tokiko 46-26
The 392 is provided with each clutch instead of the above selection mechanism, and a predetermined tool rest is selected by operating only one of them.

[Problems to be solved by the invention]

However, the above-described conventional apparatus has the following problem.

First, in the case of the cam type, the incision (X
Both axial movement) and main shaft feed (Z-axis movement) are performed by respective cams provided on one camshaft. Therefore, the shape of the cam is such that, for example, when the blade is cutting, the main shaft is not fed, so that when one of the cams is a cam angle for feeding, the other cam does not operate. Since the cam normally makes one cycle within 360 °, the available cam angle is reduced accordingly. Incidentally, performing a large amount of feed at a narrow cam angle is not preferable in terms of cam design. Therefore, the amount of feed and the complexity of processing are limited.

In addition, when the product changes, a new cam must be designed and manufactured for the product, and the cam set must be changed, so the so-called product manufacturing startup time is much longer than that of the NC machine. It is not suitable for small lot production.

In the case of the NC system, there is no such restriction.
It can easily cope with a change in the product which can be said to be a disadvantage of the cam type, that is, a small amount of various kinds of processing. However, it takes time to operate and confirm a cylinder, a clutch, and the like as an actuator, and machining of a component having a relatively simple shape reduces machining efficiency. In addition, since an actuator is required for each tool post, the apparatus becomes expensive.

An object of the present invention is to solve the above problems and to provide an extremely inexpensive and highly efficient spindle moving type automatic lathe utilizing only the advantages of both the cam type and the NC type.

[Means for solving the problem]

According to the present invention, the above object is to provide a main shaft that is rotatably and slidably guided by a bush and that is rotated by rotating the main body, the main shaft being movable in the Z-axis direction, and a plane perpendicular to the Z-axis. A lathe having a plurality of turrets that advance with respect to the main spindle so that a predetermined one can be selected, a first servo mechanism for moving the main spindle in a Z direction by a setting program, and the plurality of turrets. A plurality of cams corresponding to each turret are provided for selecting the turret and cutting the knives, respectively, and a cam shaft which receives rotation by the second servo mechanism under a setting program is provided, The multiple cams provided on the camshaft are set at angular positions so that their cam angles are sequentially continuous, making it possible to make the setting program for the first servo mechanism and the setting program for the second servo mechanism independent of each other. Going on, it is achieved by.

[Action]

In the present invention as described above, the movement of the spindle in the Z direction, that is, the movement of the material, is performed by a servo mechanism. On the other hand, the selection of the blade and the cutting of the blade (movement in the X-axis direction) are performed by a cam in the same manner as in the conventional cam type. At this time, unlike an NC machine using a conventional cam, the cam does not return to the starting point when the operation of one blade is completed, but goes sequentially from one cam to the next cam. Will be Further, in the present invention, since the movement in the Z direction and the movement in the X direction are completely separated from each other, a cam angle which is not utilized for the cam for the movement in the X direction occurs during the movement in the Z direction in the conventional cam type. The problem has been resolved. Further, according to the present invention, by using a standard cam for the cam, the cost for designing and manufacturing the cam can be reduced.

〔Example〕

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

In FIG. 1, reference numeral 1 denotes a spindle, which is rotatably supported by a headstock 2. The main shaft 1 is made of a material such as a bar (not shown).
(See FIG. 2) is provided in the Z direction shown in FIG. A pulley 3 is provided on the main shaft 1, and a driving force is transmitted to the main shaft 1 by a belt 5 stretched between the pulley 3 and a pulley 4A. In addition,
As the main shaft 1 moves in the Z direction, the belt 5
On the pulley 4A in the same direction.

A bracket 6 for containing a ball nut 7 is attached to the headstock 2, and a ball screw 8 is threadedly engaged with the ball nut 7. This ball screw 8 has bearings at both ends.
It is rotatably supported by 9 and 10, and has one end connected to the shaft of the servo motor 11. The servo motor 11
Is rotated by the signal of the setting program, and the ball screw 8
That is, the headstock 2 is moved in the Z direction. A tension spring 12 is stretched between one end of the headstock 2 and a fixed portion, and a return force to the left in the figure is urged.

A bush 13 that guides the material in a rotating and slidable manner in the Z direction is provided on an immovable frame 14 at a position forward (rightward) in the Z direction of the main shaft 1. A plurality of tool rests 16 each having a tool 15 are provided on the frame 14 so as to be movable toward the bush 13. However, only one tool post 16 is shown in the figure. A link for driving the tool post is provided at the end (the upper end in the illustrated case) of each tool post 16.
The link 17 is driven by a cam 20 via a rod 18 and a cam follower 19. Cam 20
The camshaft 24 is rotatably supported by bearings 21, 22, and 23. This camshaft 24 corresponds to each of the above turrets,
Each cam (not shown) is provided, and the tool post is driven by a mechanism including a similar link, rod, and cam follower. Each of the above cams is Z
It is shaped only by the process in the X direction regardless of the movement in the axial direction, and there is no cam angle that does not function due to the movement in the Z axis direction.

The camshaft is rotationally driven via a worm 26 and a worm wheel 27 by an X-axis servo motor 25 which rotates according to a set program. At the right end of the cam shaft 24, a cam 28 for a lever 27 for pushing out the attachment spindle 26 in the Z-axis direction is also provided. Further, a sensor 29 for detecting the origin of one rotation of the cam shaft 24 is provided at the left end of the cam shaft 24.

The camshaft 24 is also provided with a cam 31 for operating a lever 30 that opens and closes the chuck of the main shaft 1 for each rotation of the camshaft 24.

Next, in the apparatus of the present embodiment as described above, processing is performed as follows.

The servomotors 11 and 25 operate independently according to a program set when the Z-axis and X-axis feeds are required.

First, the headstock 2 is moved to a predetermined Z-direction position by the servo motor 11, and the material is brought to the machining start position.
The servomotor 11 stops at this point.

Next, when the servo motor 25 rotates, one cam 20 operates the corresponding cam follower 19 to select a predetermined tool rest 16, and the tool 15 starts cutting (moving in the X direction). Then, when the cam shaft 24 is cut by a predetermined amount, the cam shaft 24 stops, the servo motor 11 rotates again, the main shaft 1 moves in the Z direction, the blade is fed in the Z direction, and the material is processed in the same direction. When the machining is performed in the Z direction by a predetermined amount, the servo motor 11 stops.

Next, when another cutting tool is selected or cutting is performed again with the same cutting tool, a cam whose camshaft 24 is rotated by the servomotor 25 moves the corresponding tool rest.

Thus, by independently driving the servo motors 11 and 25, the Z-axis and X-axis feeds can be separately performed, so that the cam does not generate a useless cam angle due to the Z-axis feed.
It is designed as a standard cam that effectively utilizes 0mm.

〔The invention's effect〕

According to the present invention, since the Z-axis drive is separated from the camshaft and servo-driven as described above, a useless cam angle is not generated on the camshaft by that amount, so that the advantages of the cam such as high reliability and high reliability are achieved. The advantage is that complicated machining can be dealt with by effectively using the cam angle while maintaining the productivity as it is.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an apparatus according to an embodiment of the present invention. 1 Spindle 11 Servo mechanism (servo motor) 13 Bush 16 Turret 20 Cam 24 Cam shaft 25 Servo mechanism (servo motor)

Claims (1)

(57) [Claims] 1. A main shaft which is rotatably and slidably guided by a bush and is rotated by rotating the main body. The main shaft is movable in the Z-axis direction, and the main shaft is moved in a plane perpendicular to the Z-axis. In a lathe having a plurality of tool rests that have advanced and a predetermined one can be selected, a first servo mechanism for moving the main spindle in the Z direction by a setting program, and a plurality of tool rests respectively corresponding to the plurality of tool rests, A plurality of cams corresponding to each tool post are provided for selection of the tool post and cutting of the tool, and a cam shaft which is rotated by the second servo mechanism under a setting program is provided. The angular positions of the plurality of cams are set so that their cam angles are sequentially continuous, so that the setting program of the first servo mechanism and the setting program of the second servo mechanism can be made independent. This Movable main spindle automatic lathe according to claim.