JPH09253902A - Back processing method and back processing device for NC automatic lathe - Google Patents

Abstract

(57) Abstract: Back machining capable of machining the back surface of a workpiece in an NC automatic lathe equipped with a sub-spindle having a simple structure without axis control, without increasing the number of axes of the NC device. A method and a backside processing apparatus are provided. Focusing on the movement of the headstock, the backside processing device is moved toward the subspindle through the material by using the movement of the headstock to move the back surface of the work to the work held on the sub-spindle. To do this, attach a back surface processing device with a simple structure with a return spring to the tool post to perform this, and press the rear end of the back surface processing device depending on the material while holding the back surface of the work on the sub spindle side. I tried to process it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a back surface processing method and a back surface processing apparatus for an NC automatic lathe,
Especially, the round bar material held by the main shaft is processed, cut off while holding it by the sub-spindle that is arranged facing the main shaft, and the end surface (back surface) of this material is processed such as punching. The present invention relates to a back surface processing method and a back surface processing device in an NC automatic lathe to be performed.

[0002]

2. Description of the Related Art Conventionally, in order to perform back surface machining of a work, as described in, for example, Japanese Patent Publication No. 5-49401, the sub-spindle holding the work is moved by NC control and required by a predetermined tool. The back surface is processed. In this way, since the axial movement of the sub-spindle is controlled by NC, the sub-spindle can be moved to an arbitrary position or an arbitrary feed speed can be selected. Therefore, various back surface machining can be performed by combining with a necessary tool. It is a thing. Further, in recent markets, there are increasing demands for low-cost NC automatic lathes, and in order to meet this demand, it is easy to use hydraulic equipment or pneumatic equipment without using NC axis control for moving the sub-spindle. The number of devices using various drive devices is increasing.

[0003]

Among the conventional techniques,
In the former invention disclosed in JP-B-5-49401, since the sub spindle is moved by NC control, the number of NC axes is increased specially for this reason, and the structure becomes complicated. It will be very expensive. Further, the latter one using hydraulic equipment or pneumatic equipment for moving the sub-spindle has a simple structure and is inexpensive. However, the sub-spindle with this simple structure originally can only move in two positions, the forward end toward the spindle side and the reverse end opposite to this, and can be used to support long workpieces or dowel removal when cutting off workpieces. Since it is intended to be used for, the back surface processing of workpieces is extremely difficult except for a fairly limited simple back surface processing, for example, the end surface cutting on the back surface side and the chamfering of holes.

An object of the present invention is to machine a back surface of a workpiece in an NC automatic lathe equipped with a sub-spindle of a simple structure which does not have axis control by the latter NC, without increasing the number of axes of the NC device. It is to provide a back surface processing method and a back surface processing device that enable the above.

[0005]

In order to achieve this object, a back surface machining method for an NC automatic lathe according to the present invention focuses on movement of a headstock to move a headstock with respect to a work held by a sub spindle. The rear surface processing device is moved toward the sub-spindle through the material to process the rear surface of the work.

In order to carry out the above-described machining method, the present invention has a sub-spindle capable of two-position control for advancing and retracting in the spindle centerline direction at a position facing the spindle headstock, and a back surface attached to the tool rest. A back processing device having a processing device and controlling the movement of the back processing device through the material by using the movement of the headstock to process the back face of the workpiece held by the sub spindle. It is a thing.

Further, in the back surface processing apparatus, an inner diameter processing bracket attached to the tool rest, a tool spindle fitted in the inner diameter processing bracket so as to be axially movable, and the tool spindle with respect to the sub spindle. It is provided with a biasing means that is always biased to the backward position,
This urging means is composed of a return spring interposed between one end of the inner diameter processing bracket and one end of the tool spindle.

[0008]

According to the present invention, when the sub-spindle reaches the forward end toward the main spindle side after the necessary processing is performed on the long material held by the main spindle by the tool of the tool post, the sub-spindle Chuck holds the work. Here, while holding the work, the work is separated by a cutting tool and the work moves to the sub spindle side.

The tool rest is moved so that the central axis of the back surface processing device coincides with the central axis of the work. Next, the headstock is moved so that the tip of the material held on the spindle comes into contact with the end surface of the tool spindle, and by further moving the headstock, the return spring is compressed and the tool spindle is moved to the sub-spindle through the material. Advance to the side. Here, the work is rotated by rotating the sub-spindle, and the back surface of the work is perforated as the tool spindle advances. When the machining is finished, the material is also retracted by retracting the headstock, and the tool spindle returns to the original state by the urging force of the return spring.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an appearance of an NC automatic lathe which is a base of the present invention, and FIG. 2 is a perspective view of a tool rest thereof. Reference numeral 1 is a leg on which a bed 2 is provided. An L-shaped support base 5 is mounted on the bed 2, and a headstock 3 is placed so as to be movable in the Z-axis direction. As can be seen from FIG. 3, the headstock 3 is
1 is rotatably supported, and a round bar material W is held by a chuck (not shown) of a main shaft 31.

With reference to FIGS. 1 and 3, the nut 32 of the headstock 3 is screwed into the ball screw 33, and the ball screw 33
Is rotated by the Z-axis servo motor 4 (FIG. 1) to move the headstock 3 in the Z-axis direction. A groove 2a is formed in the bed 2 over the stroke of the headstock 3. The support base 5 is provided with a guide bush device 9 at a position corresponding to the center of the spindle, and guides the material W so that it is not bent by the cutting force. Further, a pair of rectangular guides 5a is provided on the vertical surface of the support base 5, and the X-axis slide 6 moves in the X-axis direction by being guided by the pair of rectangular guides 5a. Although the driving means for the X-axis slide 6 is not shown, a servomotor and a ball screw are used as in the headstock 3.

As shown in FIG. 2, in this embodiment, the tool rest 7 is such that tools can be attached on both left and right sides, and as an example, a cut-off tool and an outer diameter tool 10 are provided on the left side and a tool on the right side. A plurality of inner diameter processing tool holders 11 are attached to the inner diameter processing tool holder 11 via inner diameter processing brackets 20. The tool rest 7 can move in the vertical vertical direction (T-axis direction) with respect to the X-axis slide 6. Although only the servomotor 8 is shown in FIG. 1, it is driven by a ball screw like the headstock 3 and the X-axis slide 6.

The sub-spindle 12 is arranged on a line whose center line coincides with the center line of the main shaft 31, and is controlled by the hydraulic cylinder mechanism 13 so as to move forward and backward. As shown in FIG. 3, a collet chuck 12a is attached to the tip of the sub-spindle 12 by a chuck nut 12c, and although not shown, the collet chuck 12a is opened and closed by a cylinder mechanism or the like. An ejector 12b is provided in the sub-spindle 12 so as to be able to move back and forth. The ejector 12b moves forward as indicated by an arrow to eject the work W1 held by the collet chuck 12a. Sub spindle 1
2 has a position where the collet chuck 12a holds the work W held by the spindle 31 at the forward end, and a position where the work W1 is subjected to back surface machining at the backward end. Although not shown, the sub-spindle 12 is rotationally driven by a motor or the like while holding the work W1.

Next, the back surface processing apparatus will be described mainly with reference to FIGS. The back surface processing device 21 is attached to the inner diameter processing bracket 20. To attach this, from the inner diameter machining bracket 20 to the inner diameter machining tool holder 11
Do this after removing one of (Fig. 2). 3 and 4 show a state where the back surface processing device 21 is attached to the inner diameter processing bracket 20.

A tool spindle 23 (a drill spindle 23 is shown in the figure) is attached to the sleeve 22 by an anti-rotation key 24 so as to be slidable in the axial direction. A chuck 25 is provided at the tip of the drill spindle 23, and a drill 28 is attached to the chuck 25. A collar 27 is attached to the rear of the drill spindle 23, and a return spring 26 is provided between the collar 27 and the end surface of the sleeve 22.
Is interposed. The back surface processing device 21 thus assembled is inserted into the inner diameter processing bracket 20 so that the drill 28 is on the sub spindle 12 side, and the nut 25
It is attached to the inner diameter processing bracket 20 by tightening.

Next, the operation of the present invention will be described.

First, the round bar material W is passed through the main shaft 31 and held by a chuck so that the tip end of the material W is supported by the guide bush device 9 as shown in FIG. Here, move the tool post 7 in the T-axis direction and select the required tool, then NC
Control the headstock 3 in the Z-axis direction according to the program,
The X-axis slide 6 is controlled in the X-axis direction to perform machining on the spindle side. When the processing is completed, the rotation of the main shaft 31 is stopped, the sub spindle 12 is brought to the forward end, and the collet chuck 12
The work W is held by a. Main spindle 31 and sub spindle 1
Workpiece W is made to rotate by rotating 2 synchronously with the parting cutting tool 10.
And the work W is moved to the sub spindle 12 side (the work moved to the sub spindle 12 side is designated as W1).

Next, the sub-spindle 12 is moved to the retracted end, the X-axis slide 6 and the tool rest 7 are moved in the X-axis and T-axis, and the axis of the drill spindle 23 is aligned with the center of the spindle. As a result, the drill 28 also coincides with the axis of the work W1 on the sub spindle 12 side. Spindle 31
Is stopped and the headstock 3 is advanced toward the sub-spindle 12 side, the spindle 31 also advances while holding the material W, and the leading end of the material W hits the rear end of the drill spindle 23. When the headstock 3 is further advanced, the drill spindle 23 is pushed out toward the sub spindle 12 side through the material W while compressing the return spring 26, so that the work W1
The back surface of the can be drilled. Headstock 3
Since the movement of the drill is NC controlled and this movement is transmitted to the drill spindle 23 as it is through the material W, the feed speed and the cutting depth of the drill 28 are accurate, and moreover, according to the processing conditions. Any numerical value can be selected.

After drilling the work W1 to a predetermined depth in this way (FIG. 4), the headstock 3 is retracted and the tip of the material W is returned to its original position. It returns to its original position by the urging force of the return spring 26 (FIG. 3). Now, open the collet chuck 12a,
The work W1 is discharged by the ejector 12b, and a series of processing is completed. After that, the X-axis slide 6 and the tool rest 7 again
Is moved for X-axis and T-axis, the tool is indexed for the next processing, and the same processing is performed on the material W held by the spindle 31 as described above.

In addition to the drill spindle 23, a tap spindle or the like having the same structure is attached to the inner diameter machining bracket 20, and the tap spindle is centered on the spindle after drilling a hole by selecting and machining this. It is also possible to perform tapping by making the sub-spindle 12 rotate forward and backward in accordance with the above, and the range of processing is expanded. Further, although the tool rest 7 has a structure in which tools are attached to both left and right sides, the present invention is not limited to this, and a turret type tool rest can sufficiently implement the present invention.

[0021]

As described above, according to the back surface processing method and the back surface processing apparatus of the present invention, the following effects can be obtained. 1. Backside machining can be performed on a work held by a sub spindle by using the movement of a headstock through a material by simply attaching a backside machining device having a simple structure including a return spring. 2. Since it is not necessary to increase the number of control axes of the NC device and the simple sub-spindle is used as it is, the structure is simple and inexpensive. 3. Since the movement of the NC-controlled headstock is used, the feed rate and depth of cut of the back surface machining device are accurate, and arbitrary numerical values can be selected.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of an NC automatic lathe which is a base of the present invention.

FIG. 2 is a perspective view showing a tool rest and a sub spindle.

FIG. 3 is a schematic partial cross-sectional view showing a back surface processing method and a back surface processing apparatus of the present invention.

FIG. 4 is a partial cross-sectional view showing a state where the backside processing is performed by the backside processing method and the backside processing apparatus of the present invention.

[Explanation of symbols]

 3 Headstock 31 Main spindle 5 Support stand 6 X-axis slide 7 Tool post 9 Guide bush device 12 Sub-spindle 13 Hydraulic cylinder mechanism 20 Inner diameter machining bracket 21 Back surface machining device 22 Sleeve 23 Drill spindle 26 Return spring 27 Color 28 Drill W material W1 work

Claims (4)

[Claims] 1. An NC automatic lathe having a headstock having a spindle for holding a material and movable in its own axial direction, and an NC automatic lathe having a sub-spindle arranged opposite to the headstock, utilizing movement of the headstock. A back surface processing method in an NC automatic lathe, characterized in that a back surface processing device is moved toward a sub spindle through a material to process a back surface of a work held by the sub spindle. 2. A headstock having a spindle for holding a material and movable in its own axial direction, a sub-spindle arranged opposite to the headstock, and a cutter provided between the headstock and the sub-spindle. In an NC automatic lathe that has a base and the two-position control in which the sub-spindle moves forward and backward in the spindle centerline direction at a position facing the headstock, control is performed via the material by using the movement of the headstock. And a back surface processing apparatus for processing the back surface of the work held by the sub-spindle, the back surface processing apparatus in an NC automatic lathe. 3. The rear surface processing apparatus includes an inner diameter processing bracket attached to a tool rest, a tool spindle that is axially movably fitted to the inner diameter processing bracket, and the tool spindle with respect to a sub spindle. The back surface processing apparatus for an NC automatic lathe according to claim 2, further comprising a biasing means for biasing the position to always retract. 4. The NC according to claim 3, wherein the urging means comprises a return spring interposed between one end of the inner diameter machining bracket and one end of the tool spindle.
Back processing equipment for automatic lathes.