JPH06246503A - Automatic lathe - Google Patents

Abstract

PURPOSE:To prevent a work from skipping, by disposing a member which supports the work from the whole peripheral direction between a chucking means and a guide bush in an automatic lathe which machines the work by holding the work by a chucking means on the headstock side and also supporting it by the guide bush. CONSTITUTION:At the time of machining a work, a collet chuck 41 is rotated by a main spindle 43, and a guide bush 31 and a nut member 57 also rotate through transmission mechanisms 61, 63. At the same time, a clamping pipe 101 is placed in its driven rotation. The clamping pipe 101 is further energized to the collet chuck 41 side by a coil spring 105. When the headstock 43 goes forward, the clamping pipe 101 moves against energizing force. When the headstock 43 goes backwards, the clamping pipe 101 is moved by the energizing force without being separated from the collet chuck 41. It is thus possible to support the work located between the collet chuck 41 and the guide bush 31 by the clamping pipe 101 from the whole peripheral direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic lathe in which a headstock, an opposed headstock, a guide bush, a tool rest, etc. are arranged on a bed. The work held by the chuck means and supported by the guide bush is prevented from vibrating between the chuck means and the guide bush, thereby improving machining accuracy, preventing damage to the blade, and improving safety.
It relates to products that have improved productivity.

[0002]

2. Description of the Related Art An automatic lathe has a structure as shown in FIG. 4, for example. First, there is a bed 1, and a slide base 3 is fixed on the bed 1. A headstock 5 is mounted on the slide base 1 so as to be movable in the Z-axis direction. The headstock 5 is a headstock feed servomotor 7
The feed is controlled by. A turret slide base 9 is fixed on the bed 1. A first turret 11 and a second turret 13 are mounted on the turret slide base 9. The first tool post 11 and the second tool post 13 move in the X-axis direction orthogonal to the Z-axis. The feed of the first turret 11 and the second turret 13 is controlled by a first turret feed servomotor 15 and a second turret feed servomotor 17 attached to the turret slide base 9. is there.

A first turret 19 and a second turret 21 are attached to the first turret 11 and the second turret 13, respectively, in a rotatable and indexable state. First above
A tool 25 is detachably attached to the turret 19 via a blade holder 23. Further, a tool 29 is detachably attached to the second turret 21 via a blade holder 27. A guide bush 31 is installed on the right side of the headstock 5 in the figure. The guide bush 31 is attached to the guide bush holder 33. The work is gripped by the headstock 5 side and is supported by the guide bush 31 near the machining point.

The structure in the vicinity of the headstock 5 and the guide bush 31 will be described in detail with reference to FIG. First, a spindle 43 is rotatably installed on the spindle stock 5, and a collet chuck 41 as chuck means is attached to the tip of the spindle 43 (on the right side in FIG. 5) via a chuck sleeve 45. A cap 47 is capped on the outside of the chuck sleeve 45. A pushing sleeve 49 is installed on the left side of the chuck sleeve 45 in the figure. The collet chuck 41 is in the form of 30% and can be opened and closed freely.
The work 51 is opened by gripping 1 and opening it in the opposite direction. The collet chuck 41 is opened and closed by advancing and retracting the chuck sleeve 45 in the left-right direction in the figure via a pushing sleeve 49 by a hydraulic cylinder (not shown). That is, the collet chuck 41 is closed by advancing the pushing sleeve 49 and the chuck sleeve 45 to the right in the figure, and the collet chuck 41 is opened by retracting the pushing sleeve 49 and the chuck sleeve 45 to the left in the figure. The main shaft 43 is the bearing member 5 installed inside the housing 53.
It is rotatably supported by 5.

A nut member 57 is provided on the guide bush 31 side, but on the left side of the guide bush 31 in the drawing. The guide bush 31 is also divided into 30%,
By adjusting the screwing amount of the nut member 57, the inner diameter of the support portion at the tip (right end in the figure) of the guide bush 31 is appropriately adjusted. The guide bush 31 and the nut member 57 are provided inside the spindle 59, and a pulley 61 is fixed to the outer peripheral portion of the spindle 59. Also, the spindle 43 on the headstock 5 side
Also, a pulley 63 is fixedly attached, and via the pulley 63, a belt (not shown), another shaft member (not shown), and a belt (not shown), the pulley 61 and the spindle 5
The rotation is transmitted to 9. The spindle 59 is rotatably supported by a bearing member 67 installed in the housing 65 of the guide bush holder 33.

[0006]

The above-mentioned conventional structure has the following problems. For example, when the work 51 is processed by the automatic lathe having the above configuration, as shown in FIG. 5, the base end of the work 53 is gripped by the collet chuck 41 on the headstock 5 side, and the tip of the work 53 is held. Is supported by the guide bush 31, and in that state, desired processing is performed by the blade 25 (or 29). At that time, the collet chuck 41 and the guide bush 3
Between 1 and 1, the work 51 is in a free state,
Therefore, when the main shaft 43 is rotated, the work 51 is deformed into a bow by the action of the centrifugal force as shown by the phantom line in FIG. This becomes more remarkable as the outer diameter of the work 51 becomes smaller and the rigidity of the material of the work 51 becomes lower. Vibration occurs in the work 51 due to such a rope jumping phenomenon,
If the vibration propagates to the blade 25 (or 29),
There is a problem in that the processed surface has poor roughness and dimensional defects, which lowers the processing accuracy. Also, the blade 25
(Or 29) was also a concern. Further, when the amplitude of the rope jumping phenomenon increases and exceeds the rigidity limit of the work piece 51, the work piece 51 breaks, and the fragments scatter around and the safety of the worker is impaired. There was also such a problem. Therefore, conventionally, in order to prevent such a situation from occurring, it has been forced to operate by reducing the rotation speed of the main spindle 43, and therefore, it is not possible to obtain an appropriate cutting condition (peripheral speed), and the production The sex has deteriorated. Incidentally, with respect to such a problem, a means as disclosed in JP-A-4-250902 has been proposed. However, the means shown here is basically intended to support the work from the left and right by protruding and retracting the pair of holders from the left and right. It was difficult to install in the space.

The present invention has been made on the basis of such a point, and an object of the present invention is to prevent the occurrence of a rope jump phenomenon of a work between the chuck means on the headstock side and the guide bush, thereby improving the machining accuracy. It is to provide an automatic lathe capable of improving the tool life, extending the life of the tool, improving safety and productivity.

[0008]

In order to achieve the above object, an automatic lathe according to the present invention is constructed such that a work is gripped by a chuck means on the headstock side and is supported by a guide bush and processed. The automatic lathe is characterized in that a work supporting member for supporting the work in the entire circumferential direction is provided between the chuck means and the guide bush. At that time, it may be considered that the work supporting member is a steady rest pipe arranged so as to cover the work. Further, it is conceivable that the work supporting member is a bush installed in a nut member for adjusting the inner diameter of the work supporting portion of the guide bush.

[0009]

That is, the work supporting member for supporting the work from the entire circumferential direction is provided between the chuck means and the guide bush to suppress the rope jumping phenomenon of the work during processing. As the work supporting member, for example, a steady rest pipe may be considered. In this case, the work is supported from the outer periphery in a wide area in the longitudinal direction to prevent the runout.
Further, when the work support member is a bush built in a nut member for adjusting the inner diameter of the work support portion of the guide bush, the work is locally supported from the outer periphery between the chuck means and the guide bush. Therefore, the deflection of the work is suppressed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first embodiment of the present invention will be described below with reference to FIGS.
An example will be described. Incidentally, the same parts as those of the conventional one are designated by the same reference numerals and the description thereof will be omitted. Collet chuck 41
A steady rest pipe 101 as a work supporting member is interposed between the guide bush 31 and the guide bush 31. The steady rest pipe 101 is composed of a shaft portion 101a and a collar portion 101b. The collar portion 101b is brought into contact with the collet chuck 41 side, and the shaft portion 101a is attached to the nut member 57 and the rear end of the guide bush 31. It is installed in the state of being inserted inside. A nut member 103 is screwed and joined to the tip of the shaft portion 101a. When the nut member 103 contacts the right end surface of the nut member 57 in the drawing, the steady pipe 101 is moved toward the collet chuck 41 side. I try to prevent it from coming off. The steady rest pipe 101 is constantly urged toward the collet chuck 41 by a coil spring 105. The inner diameter of the steady rest pipe 101 is slightly larger than the outer diameter of the workpiece 51.

The operation will be described based on the above configuration. First, at the time of processing, the collet chuck 41 is rotated by the rotation of the main shaft 43, and the guide bush 31 and the nut member 57 are transmitted via the transmission mechanism including the pulleys 63 and 61.
Also rotates. Further, the steady rest pipe 101 does not rotate in synchronization with the collet chuck 41 and the guide bush 31, but it rotates along with them. The steady rest pipe 101 is constantly urged toward the collet chuck 41 by the coil spring 105.
When the headstock 5 side gradually advances from the state shown in FIG. 1 toward the guide bush 31 side, the state shown in FIG. 2 is entered. That is, the steady rest pipe 101 is moved toward the guide bush 31 side against the spring force of the coil spring 105. Also, from that state, the headstock 5
When the side retracts to the side opposite to the guide bush 31 side, the steady rest pipe 101 is urged toward the collet chuck 41 side by the spring force of the coil spring 105.
The state shown in FIG. 1 is entered without separating from the collet chuck 41. During such a series of operations, the work 51 between the collet chuck 41 and the guide bush 31 is in a state of being supported by the steady rest pipe 101 over substantially the entire area in the lengthwise direction, so that the rope jumping phenomenon Outbreak will be effectively suppressed.

According to this embodiment, the following effects can be obtained. That is, by installing the steady rest pipe 101, the work 51 which has been a problem in the past
It is possible to prevent the rope jumping phenomenon from occurring. Especially, since the work 51 is supported from the entire circumferential direction,
A higher effect can be expected. As described above, by preventing the rope jumping phenomenon of the work 51, the vibration of the work is suppressed first, so that the propagation of the vibration to the tools 25 and 29 is eliminated, and the machined surface roughness, dimensional accuracy, etc. are improved. It is possible to improve the processing accuracy. Further, it is possible to prevent damage to the tools 25 and 29 and extend the life of the tools. or,
Since the spindle 43 can rotate at high speed, the time required for processing can be shortened and the productivity can be improved. or,
It is possible to prevent breakage of the work 51 and improve safety.

Next, a second embodiment of the present invention will be described with reference to FIG. In the case of this embodiment, the guide bush 31
A bush 107 as a work supporting member is provided inside the nut member 57 for adjusting the inner diameter of the gripping portion of the work piece 51, and the work piece 51 is supported by the bush 107 to suppress the rope jump phenomenon. .

The present invention is not limited to the above embodiments. First, in the first embodiment, the shape and length of the steady rest pipe are not particularly limited. Further, the inner diameter may be appropriately changed so as to correspond to the outer diameter of the work 51. Further, as the work supporting member, the steady rest pipe and the bush are shown as an example, but other structures may be used as long as they support the work 51 from the entire circumference.

[0015]

As described above in detail, according to the automatic lathe according to the present invention, the work supporting member for supporting the work from the entire circumference is provided between the chuck means and the guide bush. By supporting the work, it is possible to suppress the rope jumping phenomenon of the work at the time of machining, thereby improving the machining accuracy, extending the life of the tool, shortening the machining time based on the high speed rotation of the spindle, and safety Can be improved. If a steady pipe is used as the work support member,
Since the work can be supported from the outer periphery in a wide area in the longitudinal direction to prevent the work from swinging, the above-described effect can be further ensured.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of a part of a headstock, a guide bush, and the vicinity thereof in a view showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a part of a headstock, a guide bush, and the vicinity thereof, showing a first embodiment of the present invention.

FIG. 3 is a sectional view showing a configuration of a part of a headstock, a guide bush and its vicinity in a view showing a second embodiment of the present invention.

FIG. 4 is a plan view showing a schematic configuration of an automatic lathe, showing a conventional example.

FIG. 5 is a cross-sectional view showing a configuration of a part of a headstock, a guide bush, and the vicinity thereof in a conventional example.

[Explanation of symbols]

 5 Headstock 31 Guide bush 41 Collet chuck (chuck means) 51 Work 57 Nut member 101 Steady stop pipe (work support member) 107 Bush (work support member)

Claims (3)

[Claims] 1. An automatic lathe configured to hold a work by chuck means on the headstock side and support the work by a guide bush to perform machining. An automatic lathe that is equipped with a work support member that supports it in the circumferential direction. 2. The automatic lathe according to claim 1, wherein the work supporting member is a steady rest pipe arranged to crown the work. 3. The automatic lathe according to claim 1, wherein the work supporting member is a bush installed in a nut member for adjusting the inner diameter of the work supporting portion of the guide bush.