JP2566570B2 - Guide bush device for automatic lathe and method for holding material in automatic lathe - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a guide bush device for an automatic lathe that includes a guide bush and processes a rod-shaped material.

[Conventional technology]

It is well known that the use of a guide bush is extremely effective when turning an elongated workpiece from a rod-shaped material. Generally, automatic lathes equipped with guide bushes are roughly classified into a guide bush support base that holds the guide bushes and a tool rest support base that supports the tool rest, and is fixed to the base or main body to hold the material. In contrast to the headstock moving type in which the headstock with the rotating spindle moves in the axial direction, conversely, the tool rest support equipped with the guide bush and tool post moves in the axial direction, and the headstock is fixed. There is also a fixed headstock fixed type, but in both cases, the turning tool fixed to the tool post is always installed at the mouth of the guide bush by making the set of the guide bush and the tool post relatively close to and away from the headstock. It is exactly the same to place it on the substrate and process it while preventing the material from bending. In the machining cycle, the spindle that grips and rotates the rod-shaped material performs the machining while approaching the guide bush, and normally the cut-off machining is performed at the closest position, after which the spindle releases the grip of the rod-shaped material. , The relative position with respect to the guide bush is fixed from the rear end of the rod-shaped material by pressing the front end of the rod-shaped material against the cutting tool by a material pushing rod provided in a known bar material feeding device,
This is a repetition of the operation of separating the headstock from the guide bush and returning it to the processing start point.

By the way, in recent years, there is an extremely strong demand for shortening the machining time for automatic lathe work, and in addition to reduction of the actual cutting time by high-speed cutting, thorough elimination of non-cutting time is desired.

[Problems to be solved by the invention]

However, in the automatic lathe that processes a bar-shaped material with a conventional guide bush, as described above, after the parting process during the processing cycle, that is, after the completion of the processing of one product, the next processing start point It takes a non-cutting time until the spindle releases the grip of the material, then the spindle and the guide bush are separated from each other, and the spindle again grips the material. Also, in some cases, at this time, the rotation of the spindle is temporarily stopped because the scratches that are likely to occur when re-gripping a material that is rotating by inertia is disliked, and the spindle is restarted after gripping the rod-shaped material. In this case, the non-cutting time further increases. According to the calculation, not only in the conventional cam type automatic lathes but also in NC automatic lathes which have made remarkable progress in recent years, the ratio of the tool change time in the non-cutting time has decreased, so this The ratio of the wasted time required for restarting the machining cycle to the total non-cutting time reaches 1/2 to 2/3.
In order to solve such a problem, conventionally, two headstocks that move in an automatic lathe of a headstock moving type are provided side by side in an array in the axial direction of a rod-shaped material, and while one headstock is processing, the other The headstock of is waiting for return until its machining start point,
By repeating this operation, what eliminates the dead time is put into practical use.

However, in this automatic lathe, two headstocks must be prepared, and as a result, the residual material length of the rod-shaped material, which is the neck of the automatic lathe with the guide bush, becomes longer. It was impossible to do.

An object of the present invention is to provide an automatic lathe that can significantly reduce the non-cutting time in a machining cycle without significantly changing the structure of a conventional automatic lathe, and thereby meet the demand for a reduction in the total machining time. Is what you are trying to do.

[Means for solving problems]

The present invention relates to a spindle that grips and rotates a raw material, a spindle stock that rotatably supports the spindle, a guide bush arranged on the spindle center line in front of the spindle stock, the guide bush and the spindle center line. A rotary shaft that is rotatably supported in an automatic lathe that includes a tool rest support that is relatively fixed in a direction, and a drive unit that relatively moves the headstock and the tool rest support together. A transmission means for driving and rotating the rotary shaft in synchronization with the main shaft; a guide bush fitted in the hollow portion of the rotary shaft and having a variable hole diameter dimension; and a hole diameter of the guide bush during rotation of the guide bush. A guide bushing device for an automatic lathe, characterized by having actuator means for selectively guiding the material in such a manner that the material can be slidably moved in the axial direction or completely gripped by changing the dimensions. By that It has been made to achieve the purpose,
Specifically, a spindle that chucks and rotates a material, a spindle stock that rotatably supports the spindle, a guide bush arranged on the spindle center line in front of the spindle stock, the guide bush and the spindle center line. Hole diameter of the guide bush in an automatic lathe for machining a rod-shaped material, which has a tool rest support that is relatively fixed in the direction, and a drive means that moves the headstock and the tool rest support relatively toward and away from each other. Is variable, and the material is guided slidably in the axial direction by changing the hole diameter of the guide bush, or it is possible to selectively grip the material completely, and the material is gripped by the spindle chuck. Adopting a bar-shaped material gripping method in an automatic lathe characterized by alternately and selectively gripping a material with a guide bush, and further performing cutting processing with the material held by the guide bush. It is those that have achieved the goal I.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings.

FIG. 1 shows an embodiment of a guide bush device for an automatic lathe according to the present invention.

A headstock 3 slidable along a support guide path 2 formed on the upper surface of a bed 1 having a peripheral structure by a feed screw or the like (not shown). A spindle 4 is rotatably supported on a spindle head 3 by bearings 4 and the like, and a front end portion of the spindle 5 is axially operated by a well-known chuck opening / closing driving means driven by a hydraulic device or the like (not shown). A chuck sleeve 6 is fitted therein, and a collet chuck 7 and its return spring 8 are inserted therein. On the other hand, a cap nut 9 is screwed onto the outer periphery of the front end of the main spindle, which prevents the collet chuck 7 from protruding, and the chuck sleeve 6 is pushed forward, so that the inner diameter taper surface of the collet chuck 7 is reduced. When the material 10 is gripped by sliding the inner diameter portion of the chuck 10 onto the taper surface of the outer diameter of the chuck sleeve 6 and the pushing force to the front of the chuck sleeve 6 is released, the chuck spring 6 is moved backward by the return spring 8. At the same time, the outer diameter taper surface of the collet chuck 7 is released and the material 10
Is released.

The main shaft 5 is provided with a timing pulley 11 at its rear end, and is fitted in a spline portion formed on the rear end side of a counter shaft 14 provided in the bed 1 and rotatably supported by bearings 12 and 13. A timing belt 16 is laid between a timing pulley 15 which is slidable in the axial direction. This counter shaft 14 has, for example, a pulley at the center thereof.
A belt 20 is connected to a pulley 19 provided on an output shaft of a main electric motor 18 to which 17 is fixed and is supported by the bed 1, so that the main shaft 5 can be rotated.
As a result, the headstock 3 can freely slide with respect to the sliding motion and can be rotated by being driven by the main motor 18 in the rotational direction.

On the upper surface of the bed 1, in front of the headstock 3, is a tool rest support.
21 are provided. A guide bush housing 22 is fixed to the tool rest support 21 on the center line of the spindle 5. The guide bush housing 22 has a bearing
The hollow rotary shaft 24 is rotatably supported thereby. A timing pulley 24a is integrally formed in the central portion of the rotary shaft 24.
The timing belt 26 is interlocked with the timing pulley 25 provided at the front end of the rotary shaft 24, whereby the rotary shaft 24 rotates at exactly the same speed as the main shaft 5 rotates as the counter shaft 14 rotates.

A taper hole is formed at the front end of the hollow portion of the rotary shaft 24, and a guide bush 27 is fitted therein. An adjusting screw 28 is screwed on the rear end of the guide bush 27. Rotating shaft 24
The rear end portion is provided with two windows 24b facing each other on the outer periphery thereof, and each of the windows 24b is provided with a lever 30 swingably supported by a pin 29 planted on the rotary shaft 24. ing. One end of the lever 30 is in contact with the flange portion 28a of the adjusting screw 28, and the other end is projected to the outer peripheral surface of the rotary shaft 24.

On the other hand, a bobbin 31 is slidably fitted in the axial direction on the outer peripheral surface of the rear end portion of the rotary shaft 24 so as to overlap the window 24b, and the inner diameter portion is tapered on the left side in the drawing. Surface, and the other end of the lever 30 is in contact with this tapered surface. The bobbin 31 is held at its outer peripheral end face by two pins 34, 35 which are supported by a pivot 32 provided on the tool rest support 21 and are planted at one end of a swingable opening / closing lever 33. The open / close lever 33 is also a tool rest support
The lever 37 is connected to the piston 37 of the hydraulic cylinder 36 supported by the other end at the other end, and is swung by the reciprocating motion of the piston 27. As a result, the bobbin 31 moves in the axial direction and contacts the tapered surface. It is possible to rock the adjustment screw 28 rearward by swinging 30 and to release the pressure.

Next, the operation of the guide bush device of the automatic lathe having such a configuration will be described.

The material 10 in which the spindle 5 and the collet chuck 7 are inserted from the rear of the headstock 3 is further inserted into the guide bush 27 and protrudes into the processing area. At this time, the hydraulic cylinder 36 is the piston
Move 37 to the push side, swing the open / close lever 33 counterclockwise to slide the bobbin 31 backward (to the right in the figure), and slide the lever 30 forward (to the left in the figure) with the adjusting screw. Swing in the direction of movement. In this state, rotate the adjusting screw 28 to create an appropriate gap between the inner diameter of the guide bush 27 and the material 10 to prevent the material 10 from bending in the radial direction during normal processing, and Is adjusted to allow sliding.

Next, the piston 37 of the hydraulic cylinder 36 is operated to the pull-in side, the guide bush 27 grips the material, and the headstock 3 is moved backward by the machining length of the product to be machined, and this is used for cutting. Use as a starting point.

In this state, the material 10 is gripped by the collet chuck 7 and at the same time, the gripping of the guide bush 27 is released to start the main electric motor 18, and the main shaft 5 and the rotary shaft 24 rotate to rotate the material 10. The material 10 is subjected to the required turning process by the radial movement of the tool 38 arranged near the front end portion of and the longitudinal movement by the sliding of the headstock 3.

When one cycle of the turning process is completed by the cut-off process, the piston 37 is operated in the direction in which the hydraulic cylinder 36 is pulled in, the opening / closing lever 33 is swung clockwise, and the bobbin 31 is slid forward. Is swung by being pressed by the tapered surface of the inner diameter of the bobbin 31, and as a result, the adjusting screw 28
The guide bush 27 is pulled rearward (to the right in the figure) via. At this time, the tapered outer peripheral surface at the front end portion of the guide bush 27 slides against the tapered inner peripheral surface of the rotary shaft 24, so that the inner diameter portion thereof is displaced inward and the guide bush 27 can grip the material 10. I can.

After that, the collet chuck 7 on the spindle side is opened, the spindle stock 3 is returned to the machining start point while the spindle 5 is rotated, and the collet chuck 7 is closed again, so that the next machining cycle can be started immediately. At this time, even if the collet chuck 7 is opened, the material 10 is gripped by the guide bush 27 and is rotated by the power, so that it continues to rotate synchronously with the collet chuck 7.
Even if the collet chuck 7 is opened / closed while the main shaft 5 is rotating, relative slippage in the rotational direction does not occur between the material 10 and the collet chuck 7, and therefore the outer periphery of the material 10 is not scratched. In other words, when the machining cycle is repeated, there is no need to stop and start the spindle, and the dead time caused thereby can be completely eliminated.

Further, according to the guide bush device of the present invention, it is not necessary to feed the material 10 in the longitudinal direction at the time of the parting process, so that the material 10 is gripped by the guide bush 27 and is rotated by power. It is also possible to carry out a parting process by giving. According to this method, the headstock 3 opens the collet chuck 7 and returns to the processing start point while the parting operation is being performed, and further the collet chuck 7 can be closed to stand by. It is possible to restart the next processing cycle immediately. In this case, needless to say, not only the dead time of stopping / rotating the spindle but also the dead time of opening / closing the collet chuck 7 and returning the headstock 3 to the machining start point can be completely eliminated.

Although the present embodiment has been described based on the well-known headstock moving type automatic lathe structure, it is obvious that there is no problem in applying the present invention to the headstock fixed type.

[Effects of the Invention] As described above, the guide bush device for an automatic lathe according to the present invention has the following great effects.

(1) It is possible to almost safely eliminate the dead time associated with the end and restart of the machining cycle in the case of continuous machining of rod-shaped materials, reduce the non-cutting time, and thus greatly reduce the total machining time. To do.

(2) It is extremely easy to machine a product having a length exceeding the headstock stroke by repeatedly returning to the machining starting point by opening the collet chuck while gripping the material with the guide bush. Can be done.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a guide bush device for an automatic lathe according to the present invention. 1 …… Bed, 3 …… Spindle head, 5 …… Spindle, 7 …… Collet chuck, 10 …… Material, 14 …… Counter shaft, 21 …… Turret support, 24 …… Rotary axis, 27 …… Guide bush, 28 …… adjustment screw, 30 …… lever, 33 …… opening / closing lever, 36 …… hydraulic cylinder, 37 …… piston.

Claims (2)

(57) [Claims] 1. A spindle for holding and rotating a raw material, a spindle stock for rotatably supporting the spindle, a guide bush arranged on the spindle center line in front of the spindle stock, the guide bush and the spindle center. In an automatic lathe equipped with a tool rest support that is relatively fixed in the line direction and a drive means that relatively moves the headstock and the tool rest support away from each other, a hollow rotation that is rotatably supported. A shaft, a transmission means for driving and rotating the rotary shaft in synchronization with the main shaft, a guide bush fitted in the hollow portion of the rotary shaft and having a variable hole diameter, and a hole for the guide bush during rotation of the guide bush. A guide bush device for an automatic lathe having an actuator means for selectively guiding the material so that the material can be slidably guided in the axial direction or completely grasped by changing the diameter dimension. 2. A spindle for chucking and rotating a material, a spindle stock for rotatably supporting the spindle, a guide bush arranged on the spindle center line in front of the spindle stock, the guide bush and the spindle center line. Hole diameter of the guide bush in an automatic lathe for machining rod-shaped materials, which has a tool rest support that is relatively fixed in the direction and a drive means that relatively moves the headstock and the tool rest support toward and away from each other. The dimensions are variable and the hole diameter of the guide bush is changed to guide the material so that it can slide in the axial direction, or it is possible to selectively hold it completely. , A method of gripping a rod-shaped material in an automatic lathe, characterized by alternately and selectively gripping a material with a guide bush.