JPH0741449B2 - Machine Tools - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machine tool that performs cutting such as peripheral surface cutting and grooving while supporting both ends of a shaft work while rotating the work.

Conventional technology Conventionally, for example, NC is used as a machine tool for performing this type of cutting process.
A lathe is used. This NC lathe is composed of a headstock, tailstock, and a tool rest on the feed unit. For example, in the case of a work, the center of the tailstock is moved back and forth with respect to the spindle of the headstock according to the length of the work. The both ends of the work are supported by, and the work is cut by pressing the tool of the tool post from one side of the work peripheral surface while rotating the work and feeding it in the cutting direction or the axial direction. In this case, the turret is, for example, a hexagonal turret head to which a plurality of various tools are attached, and the turret head is indexed and rotated for each tool to perform tool setup change according to various processes. It was

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, according to the conventional method, the turret head has an indexing rotary operation for tool exchange in each process, and a tool approach, relief and cutting feed at the start and end of cutting. Turret head drive unit structure becomes very complicated because it requires three types of drive control systems: forward / backward movement for cutting and feed movement in the axial direction for cutting feed. It took a considerable amount of time, including many times of indexing, and the processing efficiency was poor.

Also, the center slide surface of the tailstock and the slide surface of the tool post are formed on different machine frames, making it difficult to install and adjust, and it takes a very long time to obtain the accuracy of the shaft center. There was also a problem in terms of accuracy.

Object of the Invention Here, an object of the present invention is to perform all operations during machining by two kinds of feeds of a tool holder, a feed in a rotational direction and a feed in an axial direction, and a drive control system for them can be simplified. At the same time, it is to shorten the indexing time and improve the processing efficiency. Further, since the sliding bearing surface of the tool holder and the sliding bearing surface of the center are formed on the same frame, the parallelism between them and the centering accuracy between them and the spindle are very high, and the machining accuracy of the workpiece is high. To improve.

SUMMARY OF THE INVENTION Therefore, in the machine tool of the present invention, in a feed unit frame in which a center opposed to a spindle is provided slidably in an axial direction,
A guide cylinder is formed parallel to the center of rotation of the spindle, and a tool holder that holds multiple tools in the radial and axial directions is rotatably and axially slidably attached to the guide cylinder. The tool holder is configured to feed the tool holder in the rotational direction for relief, approach, cutting feed and tool exchange, and to feed the tool holder in the axial direction for cutting feed.

First Embodiment Referring to FIG. 1, a machine tool 1 of the present invention comprises a spindle 3 rotatably mounted on a headstock 2 for holding one end of a work W to rotate the work W, and a spindle 3 for rotationally driving the spindle 3. A drive motor 4 and a feed unit frame 5 spaced apart from the headstock 2 are provided on the rotation center line L of the spindle 3 so as to face the spindle 3 and to be rotatable and axially slidable. A center 6 that holds the other end of the work W, a center drive unit 7 that is provided in the feed unit frame 5 and feeds and drives the center 6 in the axial direction,
A guide tube portion 8 formed on the feed unit frame 5 and parallel to the rotation center line L of the spindle 3, and a guide tube portion 8 rotatably and slidably supported in the guide tube portion 8 in the axial and radial directions. Tool holder 9 that holds multiple tools T in one direction
And a holder rotation drive unit 10 provided on the feed unit frame 5 for driving the tool holder 9 in the rotating direction to perform relief, approach, infeed of the tool T with respect to the work W, and tool exchange, and the feed unit frame. 5, which drives the tool holder 9 in the axial direction to drive the tool T
Drive unit for holder feed for positioning and cutting feed
It has 11 and.

The spindle driving motor 4 is fixed on a saddle 13 which is slidably provided on the left and right in the drawing with respect to a base 12, and a pulley 14 is attached to the tip of a motor shaft 4a thereof. The rotation of the motor 4 is transmitted from the pulley 14 to the pulley 17 of the lower spindle shaft 16 via the belt 15 and the like to rotate the spindle 3 at the tip. Headstock 2 supporting the spindle shaft 16
Is fixed on the saddle 13 and rotatably supports the spindle shaft 16 by a plurality of bearings 18 fitted therein.

The saddle 13 is driven by a feeding device (not shown) on the base 12, and can be moved and adjusted to a predetermined position according to the length of the work W to be processed.

Further, the feed unit frame 5 is spaced apart from and opposed to the base 12.
Is erected. A cylinder S that constitutes the center drive unit 7 is formed at a position facing the spindle 3 of the feed unit frame 5, and a piston 19 integrally holding the center 6 is slidably inserted therein. There is.

Further, a guide cylinder portion 8 is formed at a position above the cylinder S of the feed unit frame 5 and parallel to the length direction of the cylinder S, that is, parallel to the rotation center line L of the spindle 3. A shaft 19a of the tool holder 9 is rotatably supported by a bush 19 fitted on the inner surface of the guide cylinder 8 and slidably in the axial direction, that is, in the left-right direction.

The holder portion 9b of the tool holder 9 is detachably attached to the shaft portion 9a and can be replaced according to the type of the work W to be processed.

As an example of the tooling of the tool holder 9, when machining the work W having the shape shown in FIG. 3, the first tool T ₁ , the second tool T ₂ , and the second tool T ₂ for cutting the peripheral surface are arranged in a row in the axial direction of the holder portion 9b. Each of the three tools T ₃ is attached to the work W so as to be adjustable in the protruding direction, and the fourth tool T for grooving is provided in a row at an angular position slightly deviated from the above tools T ₁ , T ₂ and T _{3. The 4th} and 5th tool T ₅ are mounted in the same way, and this tool T ₄ , T
6th tool T for spot facing in a row at an angular position slightly offset from _5
6, 7 the tool T ₇ is mounted similarly.

Further, the shaft portion 9a of the tool holder 9 has a screw portion 21 at the rear portion.
And the spline portion 22 are integrally formed.

A feed nut 25, which is rotatably and fixed in the left-right direction, is screwed onto the outer periphery of the screw portion 21 via bearings 23 and 24 mounted in the guide cylinder portion 8.
A gear 26 is integrally fitted to the outer periphery of the.

Further, the feed unit frame 5 is provided with a servomotor M ₁ which constitutes the holder feed drive section 11, and a shaft 28 is connected to the motor shaft 20 via a coupling 27. The shaft 28 is provided in parallel with the shaft portion 9a of the holder 9 and has a bearing 29 mounted in the feed unit frame 5,
It is rotatably supported by 30. A transmission gear 31 that meshes with the gear 26 is integrally attached to the shaft 28, and the rotation of the motor shaft 20 is transmitted by the gear 31 to the screw portion 21 via the gear 26 and the nut 25 so that the holder 9 is axially moved. It is designed to be driven to feed.

A spline tube 32 is engaged with the outer periphery of the spline portion 22 at the rear of the holder 9, and the spline tube 32 is rotatable and left and right via bearings 33 and 34 mounted in the guide tube portion 8. It is fixedly installed in the direction.
A gear 35 is integrally formed on the spline cylinder 32. The gear 35 is a rack shaft perpendicular to the plane of FIG.
36 engaged. As shown in FIG. 2, the rack shaft 36 is connected to a feed screw 37, and the feed screw 37 is moved forward and backward by a servo motor M ₂ forming the holder rotation drive unit 10 formed in the feed unit frame 5. To be done. That is,
The rack shaft 36 is moved in the axial direction together with the feed screw 37 by the rotation of the servomotor M ₂ , and the gear 35 is rotated to drive the holder 9 from the spline tube 32 through the spline portion 22 in the rotational direction. Has become.

Further, dogs 38, 39, 40 for tool position detection are provided at the end of the rack shaft 36, and the peripheral surface cutting tools T ₁ , T ₂ , T ₃ and the groove cutting tool T are provided at each step. ₄ , T ₅ and counterbore tool T ₆ ,
This is for detecting that each T ₇ has been set up at the processing start position.

Further, a work transfer device 41 such as a transfer device is provided between the base 12 and the feed unit frame 5, and both ends of the work W are gripped by the two left and right transfer claws 42 and 43 for processing positions. To the above spindle 3 and center 6
Work W is handed over in the meantime. After the processing is completed, the work W is received from between the spindle 3 and the center 6 and further carried out to the next processing station.

Operation of the Embodiment First, before machining is started, the holder 9 is moved to the starting position of the peripheral surface cutting which is the first step as shown in FIG. 3 by the tools T ₁ , T ₂ and T _3.
Is located at a relief angle position that does not interfere with the work W. At this time, the dog 38 hits the detection switch 45 and detects that the tools T ₁ , T ₂ , and T ₃ have been set up.

In this state, the work W is carried in by the transfer device 41, and when one end of the work W is inserted into the spindle 3, the other center 6 advances by the action of the cylinder S and supports the other end of the work W. After that, the transfer claws 42 and 43 are retracted from the work W.

Then, the spindle 3 is rotationally driven by the drive of the spindle driving motor 4 to rotate the work W. Next, the servo motor M ₂ rotates to move the rack shaft 36 and rotate the holder 9 through the spline portion 22 by a predetermined angle. This is the approach motion of the tool T. That is, the tool T ₁ ,
T ₂ and T ₃ come into contact with the peripheral surface of the work W and the cutting is started. At the same time, the servomotor M ₂ is stopped, so that the rotation of the holder 9 is locked. In this way, the motor M ₁ is driven while keeping the cut amount constant, and the holder 9 is driven through the shaft 28, the gears 31, 26, the nut 25, and the screw portion 21.
Cutting feed in the axial direction. By moving the holder 9 forward to the position shown by the chain double-dashed line in FIG. 3, the tool T ₁ is on the peripheral surface of the work W, the tool T ₂ is on the peripheral surface of the work W, and the tool T ₃ is on the peripheral surface of the work W. The motor M ₁ is stopped after cutting the face c.

Next, the second step, grooving, is performed. When the cylinder S is actuated to rotate the holder 9 by a set angle for tool exchange from the state where the first process is completed, the tool is changed as shown in FIG.
At the same time that T ₄ and T ₅ are located on the peripheral surface of the workpiece W,
T ₁ , T ₂ and T ₃ are set up at relief angle positions that escape from the peripheral surface of the work W. At this time, the dog 39 of the rack shaft 36
Strikes the detection switch 45 and detects that the tool has been set in the tool in the second step.

It should be noted that the NC control simultaneously drives the rotation of the servo motor M ₂ and simultaneously drives the motor M ₁ to impart a rotation in the same direction as the rotation direction of the holder 9 to the nut 25 so that the holder 9 is rotated.
A compensation operation is added so that the feed in the axial direction becomes 0 even if the is rotated.

From this state, when the holder 9 is further rotated by the set amount by the action of the servo motor M ₂ , the blade edges of the tools T ₄ and T ₅ are moved in the cutting direction and set on the peripheral surface of the rotating work W. The depth of cut is processed. When this grooving is completed, the process moves to the third step, which is a spot facing process.

When the servomotor M ₂ is actuated from the state where the second step is completed and the holder 9 is rotated by the set angle for tool exchange, the tools T ₆ and T ₇ are positioned on the peripheral surface of the work W as shown in FIG. At the same time, the tools T ₄ and T ₅ are set up to the relief angle that escapes from the peripheral surface of the work W. At this time, the dog 40 of the rack shaft 36 strikes the detection switch 46 to detect that the dog 40 has been set in the tool of the third step.

Then, from this state, when the holder 9 is further rotated a set amount by the action of the servo motor M ₂ , the cutting edges of the tools T ₆ and T ₇ are moved in the cutting direction, and the edge edge of the rotating work W, The counterbore processing of the depth of cut set in g is performed.

When the machining is completed after the completion of the third step, the servo motor M ₂ acts in reverse to rotate the holder 9 in the opposite direction, so that all the tools T _{1 to} T ₇ interfere with the work W in the rotation direction and the axial direction. The relief angle position is not set, and the holder M is retracted by the drive of the motor M ₁ to return to the initial position shown in FIG.

Then, when the transfer claws 42, 43 of the transfer device 41 are raised and grip both ends of the work W, the cylinder S acts to retract the center 6 and pull out the front end 6a from the work W. Transport claws 42, 43
Removes the work W from the spindle 3 while holding the work W, and carries the work W to the next processing station.

Modified Example As shown in FIG. 6, a plurality of feed unit frames 5 having the same headstock 2 and the same holder 9 are arranged side by side, and the drive motor 4 is attached to the gear 17 ′ of each headstock 2. Wheel 14
In addition, a plurality of belts 15 'corresponding to the number of units are connected to each other as shown by the two-dot chain line in FIG. ₁ , and the driving of each holder 9 is also transmitted by the servomotors M ₁ and M ₂ , respectively. It is possible to process individual workpieces W at the same time, and it is possible to perform very compact and efficient processing.

Further, if the tooling of the holder 9 is variously changed according to the shape of the work W, it is possible to easily cope with various processing.

As described above, according to the machine tool of the present invention, the cutting feed is performed by the feed control in the axial direction of the tool holder, the tool change is performed by the feed control in the rotation direction of the tool holder, the tool approach to the work, Since cutting and relief operations can be performed, drive control is greatly simplified, the indexing time for tool setup change is minimized, and multiple points can be set by multiple tools in one process. Since the processing can be performed simultaneously, the number of steps can be reduced and the processing time can be shortened significantly.

Further, since the sliding guide portion of the center and the guide cylinder portion of the tool holder are formed in the same feed unit frame, the parallelism between them can be reliably maintained, and therefore the machining accuracy can be improved.

Further, by changing the tooling according to various works, it is possible to easily cope with works having complicated shapes, and there are many advantages such as versatility and extremely efficient machining.

[Brief description of drawings]

1 is a vertical sectional view showing a machine tool of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a tool holder tooling and a front view showing the position of the tool holder during the first step. Fig. 4 is a front view showing the position of the tool holder during the second step, Fig. 5 is a front view showing the position of the tool holder during the third step, and Fig. 6 is a modified example of the holder arrangement. FIG. 1 ... Machine tool, 2 ... Headstock, 3 ... Spindle, 4
...... Spindle drive motor, 5 …… Feeding unit frame,
6 ... Center, 6a ... Tip part, 7 ... Center drive part, 8
…… Guide cylinder, 9 …… Tool holder, 10 …… Holder rotation drive unit, 11 …… Holder feed drive unit, T …… Tool, L …… Rotation center line, W …… Workpiece.

Claims (1)

[Claims] 1. A spindle rotatably mounted on a spindle head for gripping one end of the workpiece to rotate the workpiece, a spindle drive motor for rotatably driving the spindle, and a feed provided separately from the spindle head. A unit frame is provided on the rotation center line of the spindle and has a rotatable tip portion for holding the other end of the work, the center being slidably provided in the axial direction, and the center provided on the feed unit frame. A center drive part for axially driving the center, a guide cylinder part formed in the feed unit frame and parallel to the rotation center line of the spindle, and rotatable in the guide cylinder part and slidable in the axial direction. A tool holder that is supported by and holds a plurality of tools in the axial direction and the radial direction, and is provided with the feed unit frame to drive the tool holder in the rotating direction to relieve the tool with respect to the workpiece, It was equipped with a drive unit for holder rotation that performs a plouch, a cutting feed, and a tool change, and a holder feed drive unit that is provided in the feed unit frame and drives the tool holder in the axial direction to drive and position the tool and feed the cutting. A machine tool characterized by that.