JPH06277903A - Lathe and machining method for bar material in lathe - Google Patents

Abstract

PURPOSE:To facilitate high speed machining work where a workpiece having fixed length is machined from a thin long raw material by machining process including cutting-off work carried out by a lathe. CONSTITUTION:In a lathe having a main spindle 3 provided with a through hole 2 for supplying a bar material 7, a freely rotatable chuck 22 being opposite to a main spindle chuck 4 is provided so that it may be movingly driven and evacuated from the machining domain A of the lathe. In machining the bar material 7, the tip of the bar material 7 fed in through the through hole 2 of the main spindle is grasped by the freely rotatable chuck 22 advancing into the machining domain, and the main spindle 3 is rotated to cut off the tip of the bar material 7, and then the main spindle chuck 4 is opened to make the bar material 7 evacuate, and a work piece 32 cut off from the bar material 7 is delivered from the freely rotatable chuck 22 to the main spindle chuck 4, and then the freely rotatable chuck 22 is made evacuate from the machining domain A for turning the work piece 32. In addition, two-main spindle opposite lathe can be operated without providing the freely rotatable chuck.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for processing a bar material fed into a processing region through a through hole provided in a shaft center of a main shaft into a workpiece of a predetermined length by a processing operation including a cut-off processing. The present invention relates to a lathe and its processing method.

[0002]

2. Description of the Related Art As a method of processing a work piece of a predetermined length from a long and narrow material (bar material), a bar feeder that intermittently transfers a material that is freely rotatably supported by a predetermined length to a main shaft of a lathe. The tip of the bar material is fed into the machining area of the lathe through the through hole provided, the bar material is gripped by the spindle chuck, the tip of the bar material fed into the machining area is turned, and then the tip of the processed bar material A processing method of cutting off a part by parting off is adopted. If such a processing method is adopted, there is an advantage that a long material can be directly supplied to a lathe to process a work piece of a desired length, and a cutting step of the material as a pre-processing is unnecessary, so that the material can be transported and lathed. There is a feature that it is easy to automate the supply to.

[0003]

However, in the above-mentioned conventional method, since the entire long material rotates during the turning of the work, the whirling of the material and the supporting rigidity of the material on the bar feeder side cannot be increased. In addition, the rotation speed of the spindle cannot be increased and the processing speed cannot be increased.
In recent lathes, it is not uncommon to perform machining by rotating the spindle at a rotational speed of 6000 rpm or more in order to improve the machining efficiency, but if the above-mentioned machining method is adopted, It is impossible to perform processing at such high rotation. The bar feeder is equipped with a vibration suppression unit that prevents whirling of the material to prevent whirling of the material.However, as the number of rotations increases, the vibrating force that acts from the material becomes extremely large and vibration is suppressed. If the belt of the unit breaks, processing becomes impossible.

That is, the conventional processing method for processing a workpiece of a predetermined length from a long material by processing including parting-off processing cannot cope with the speedup of a lathe, and a lathe capable of high-speed rotation and high-speed cutting are possible. Even if such a tool is used, there has been a problem that the machining efficiency cannot be improved. Therefore, it is an object of the present invention to obtain a technical means capable of speeding up the process of processing a workpiece of a predetermined length from an elongated material by a process including a parting process.

[0005]

A lathe according to the present invention is a lathe in which a through hole 2 serving as a passage for feeding a bar material 7 into a processing region A is provided in the shaft center of a spindle 3,
A free-rotating chuck 22 is provided on the axis of the spindle, facing the spindle chuck 4 attached to the tip of the spindle. The free-rotating chuck 22 can be driven to move in the axial direction of the spindle 3 and can be retracted from the machining area A of the lathe. It is characterized by being provided.

In the method for processing a bar material in the lathe according to the present invention, the tip of the bar material 7 is fed into the processing area A through the through hole 2 provided in the main shaft 3 for a predetermined length, and the main shaft chuck 4 mounted on the main shaft 3 and The bar material 7 is gripped by the free-rotating chuck 22 that has advanced to the position facing the tip of the bar material 7, and the main shaft 3 is rotated to rotate the main shaft chuck 4 and the free-rotating chuck 2 described above.
2, the tip of the bar material 7 is cut off, the spindle chuck 4 is opened to retract the bar material 7, the free rotation chuck 22 is moved to the spindle side by a predetermined amount, and then the spindle chuck 4 is closed to close the bar material. The cutting side end of the work piece 32 separated from 7 is gripped, then the free rotation chuck 22 is detached from the tip of the work piece 32 and retracted from the processing area A, and then the spindle 3 is rotated to rotate the work piece 32. It is characterized by performing turning.

The bar material processing method in the two-spindle facing lathe according to the present invention is carried out by using the bar material 7 through the through hole 2 provided in the spindle 3.
The front end of the bar material 7 is fed into the processing region A by a predetermined length, and the bar material 7 is grasped by the main shaft chuck 4 mounted on the main shaft 3 and the counter shaft chuck 41 which is advanced to a position facing the front end of the bar material 7, and the main shaft 3 and the counter shaft 3 Is rotated synchronously, the tip of the bar member 7 is cut off between the main shaft chuck 4 and the counter shaft chuck 41, the main shaft chuck 4 is opened to retract the bar member 7, and the counter shaft chuck 4
After moving 1 to the spindle side by a predetermined amount, the spindle chuck 4 is closed to grip the cutting side end of the workpiece 32 separated from the bar material 7, and then the opposing shaft chuck 41 is separated from the tip of the workpiece 32. It is characterized in that the workpiece 32 is evacuated from the machining area A, and then the spindle 3 is rotated to perform the turning of the workpiece 32.

In the above-described two types of bar material processing methods, the tip of the bar material 7 is fed into the processing area A by a predetermined amount, and the bar material 7 is gripped by the spindle chuck 4 to form the outer shape of the tip portion of the bar material 7. Then, the free rotation chuck 2 is attached to the tip of the bar member 7.
2 or the opposed shaft chuck 41 can be faced, and the free-rotating chuck 22 or the opposed shaft chuck 41 can hold the tip end portion of the bar material after the outer shape processing, and then perform the cut-off operation.

[0009]

In the above-described machining method of the present invention, the tip of the bar material inserted in the machining area A is cut off from the bar material by the cut-off processing at an early stage of machining, and then the bar material is retracted from the machining area. The separated work piece 32 is gripped by the spindle chuck 4 and a predetermined turning process is performed.

Therefore, when the workpiece 32 is turned, since the workpiece 32 is no longer separated from the tip of the bar member 7, the bar member 7 does not rotate, and the problem of whirling of the elongated material is eliminated. Does not happen. Therefore, in the above-described processing of the present invention, the rotation speed of the spindle 3 is restricted by the whirling of the bar material 7 until the cut-off processing is completed. Since it is performed immediately after being inserted into the bar material, or after performing a simple outer peripheral processing (peeling) on the tip end portion of the bar material 7, the processing time until the workpiece 32 is separated from the tip end of the bar material 7 is the whole. Since the machining time is extremely short and most of the machining can be performed at a high spindle rotation speed, it becomes possible to increase the spindle rotation and improve the machining efficiency of the work.

Moreover, since the axial cutting of the material is performed by the cut-off processing, no preprocessing is required and the supply of the material to the lathe does not become complicated. The outer peripheral processing of the tip of the bar material 7 before the cut-off processing is performed so that the tip of the bar material 7 can be accurately grasped by the free rotation chuck 22 or the counter shaft chuck 41. In the case of a polished steel rod or the like, such outer peripheral processing is unnecessary.

If the lathe used is a two-spindle facing lathe,
The processing method of the present invention can be implemented only by changing the control program. In the case of a single-spindle lathe, the lathe according to the present invention is used in which a free-rotating chuck 22 that can freely move forward and backward is provided at a position facing the main spindle chuck 4.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cross-sectional side view of essential parts showing an embodiment of a lathe according to the present invention. A spindle 3 having a through hole 2 at its axial center is rotatably supported on the spindle headstock 1, and a spindle chuck 4 is attached to the tip thereof. The rotary drive mechanism of the main shaft 3 is omitted in the figure. In the through hole 2 of the spindle 3, the bar feeder 5
A cantilevered sleeve 6 is inserted so that it can freely rotate on its side. The sleeve 6 has an inner diameter corresponding to the outer diameter of the inserted bar member 7, and the sleeve 6 and the main shaft 3 are held in a non-contact state.

Below the spindle chuck 4, there is provided a swivel bracket 9 which is freely rotatable around a swivel shaft 8 in the vertical direction, and two parallel guide rods 10 extend from this swivel bracket 9. The ends of the two guide rods are connected by an end plate 11. The two guide rods 10 are arranged in the direction perpendicular to the paper surface of FIG.
Shows only one on the front side. A swivel cylinder 12 is provided on a side surface of the headstock 1, and a tip of a rod of the swivel cylinder 12 and a pin 13 provided vertically to a side of the swivel bracket 9 (front side of the swivel shaft 8 in the drawing). The pivot bracket 9 is reciprocally pivoted by the forward / backward movement of the cylinder 12 to reciprocally move the free rotation chuck 22 to a position on the axis of the main shaft 3 and a retracted position.

A slide block 16 is slidably supported on the two guide rods 10 in the axial direction of the guide rod 10, and a guide rod 10 is mounted on a cylinder 17 formed in a guide rod penetrating portion of the slide block 16. The piston 18 fixed to is fitted. By supplying pressure fluid to the cylinder chambers 19 and 20 formed on both sides of the piston 18, the sliding block 16 reciprocates along the guide rod 10.

The sliding block 16 is provided with a freely rotating chuck 22 that advances to a position facing the spindle chuck 4. The free-rotating chuck 22 shown in FIG. 1 has a structure in which a freely rotatable roller 23 parallel to the main shaft 3 is axially supported at three vertex positions of an equilateral triangle centered on the shaft center of the main shaft 3.
The distances from the main shaft center of the three rollers 23 are adjusted to the outer diameter of the tips of the bar members 7, and the tips of the bar members 7 can be just inserted between the three rollers 23. It has a positional relationship.

A knockout cylinder 26 is formed in a portion on the extension of the shaft center of the main shaft 3 when the sliding block 16 advances, and a piston 28 having a piston rod as a knockout pin 27 is fitted therein. In the swing cylinder 12, the free-rotating chuck 22 is opposed to the main spindle chuck 4 and the main spindle 3
The guide rod 10 becomes parallel to the main shaft 3 when it is advanced to the axis of, and the revolving cylinder 12 is moved to the retreat side, so that the free rotating chuck 22 retreats from the machining area A of the lathe. It comes to the position of 4 side (front side of the figure). A bellows 29 is mounted between the sliding block 16 and the end plate 11 to prevent cutting chips from adhering to the guide rod 10. It should be noted that FIG. 1 shows a state immediately before the parting process in which the parting bite 31 mounted on the turret 30 is indexed to the processing position.

Next, a method of processing the bar material 7 in the lathe shown in FIG. 1 will be described. At a predetermined timing, the bar material 7 is intermittently moved by an axial feed device (not shown) of the bar feeder 5, and the tip of the bar material 7 is supplied to the processing area A of the lathe for a predetermined length. Then, the bar material 7 is gripped by the spindle chuck 4, and if necessary, an external turning tool is indexed by the turret 30, and the outer circumference of the tip 7a of the bar material is adjusted so as to have an outer diameter corresponding to the roller 23 of the free rotation chuck 22. Perform processing.

Next, the sliding block 16 is attached to the guide rod 10.
In the state of being moved to the tip end side of the guide rod 10, the revolving cylinder 12 is operated to advance the free rotation chuck 22 in the retracted position to a position facing the spindle chuck 4, and then the cylinder 17 formed in the penetrating portion of the guide rod 10. Is supplied with a working fluid to move the free-rotating chuck 22 toward the spindle chuck 4. By this operation, the tip of the bar material 7 is inserted between the three rollers 23 of the free-rotating chuck 22,
It is in a state of being held by the free rotation chuck 22. When the main shaft 3 is rotated in this state, the bar member 7 rotates,
Work piece 3 from the tip of the bar material 7 with a parting tool 31
Separate 2 During the parting process, the tip of the bar material supported by the free-rotating chuck 22 can be freely rotated by the rotation of the roller 23.

Since the work piece 32 separated from the tip of the bar material 7 is held by the roller 23, the spindle chuck 4 is opened in this state, and the axial feeding device of the bar feeder 5 is retracted to move the bar material 7 The tip of the is retracted from the inside of the spindle chuck 4. Next, the sliding block 16 is further moved to the spindle 3 side, and the cut end side of the workpiece 32 is inserted into the spindle chuck 4. After the spindle chuck 4 is lightly closed, working fluid is supplied to the knockout cylinder 26, the knockout pin 27 is advanced, and the cut end of the work piece 32 is pressed against the bottom portion of the spindle chuck 4. Is closed and the workpiece 32 is gripped with a predetermined force.

Next, the sliding block 16 is attached to the guide rod 10.
After moving to the front end side of the spindle 3, the revolving cylinder 12 retracts the free-rotating chuck 22 from the axis of the spindle 3. After the free rotation chuck 22 is retracted from the processing area A, the spindle 3 is rotated at a high speed, and the workpiece 32 is processed by using the blade attached to the turret 30.

In a lathe equipped with a Z-axis drive device for the tail stock that automatically moves the position of the tail stock of the lathe, as shown in FIG. The lathe of the invention can be constructed and processing can be performed by the method of the invention. That is, as shown in FIG.
After the tip of the bar material 7 is supplied to the processing area A, the tail stock 35 is advanced toward the main shaft 3 to freely rotate the chuck 22 attached to the tail stock 35.
While holding the tip of the bar material 7 with
The bar material is gripped by and the spindle 3 is rotated to separate the workpiece 32 from the tip of the bar material 7. Then, after the tip of the bar member 7 is retracted from the spindle chuck 4 as in the first embodiment, the tail stock 35 is moved to the spindle 3 side and the cut end portion of the separated work piece 32 is inserted into the spindle chuck 4. Then, the spindle chuck 4 is closed, the free rotation chuck 22 is then opened to retract the tail stock 35 from the machining area A, and the spindle 3 is rotated at a high speed to machine the workpiece 32.

In the example of FIG. 2, a structure is shown in which the tail stock 35 is moved forward and backward by the feed screw 37 which is rotationally driven by the servo motor 36.
The structure and processing method of the present invention can be realized even in the structure in which the hydraulic cylinder is moved back and forth.

Opposing shaft 40 facing the main shaft 3 on the same axis.
And a drive mechanism for this opposing shaft is provided, and both
In a two-spindle facing lathe that allows 40 to be closely spaced,
The processing method of the present invention can be carried out without adding a special chuck. That is, as shown in FIG.
The tip end of the bar material inserted into the processing area A from the through hole provided in the main spindle 3 is gripped by the main spindle chuck 4 and the counter shaft chuck 41 moved to the main shaft 3 side, and the drive motor 42 on the main shaft side and the counter shaft side The main shaft 3 is rotated in a state in which the opposed shaft 40 is freely rotatable by synchronously rotating the drive motor 43, or by disposing a clutch in the drive system on the opposed shaft side and disengaging the clutch, and the main shaft 3 is rotated. Separate the workpiece 32 from the tip of 7. Then, after the tip of the bar member 7 is retracted from the spindle chuck 4, the opposing shaft 40 is further advanced to the spindle side and the cut end of the work piece 32 that has been cut is inserted into the spindle chuck 4 and gripped. 41 is opened, the opposing shaft 40 is retracted, and the spindle 3 is rotated at high speed to process the workpiece 32.

When carrying out the method of the present invention on a two-spindle facing lathe, the facing shaft 40 is cut after the workpiece 32 is cut off and before the workpiece is transferred to the spindle chuck 4.
It is also possible to complete turning on the cut end side of the workpiece 32 on the side. In this case, the workpiece 32, which has undergone the turning process on the cut end side, is transferred to the spindle chuck 4 side and processed on the spindle chuck 4 side.

[0026]

According to the present invention described above, in a machining method for continuously machining a workpiece of a predetermined length from a long material, the machining efficiency of the workpiece can be improved by rotating the spindle of the lathe at high speed. Since the workpiece is cut off from the tip of the material at an early stage of processing, the processing is performed with the material stopped, so that the load on the bar feeder is significantly reduced. Further, according to the lathe of the present invention, there is an effect that the processing method of the present invention can be carried out in a single-axis lathe.

[Brief description of drawings]

FIG. 1 is a partial sectional side view schematically showing a main part of a first embodiment.

FIG. 2 is a sectional view schematically showing a second embodiment.

FIG. 3 is a plan view schematically showing a third embodiment.

[Explanation of symbols]

 2 Through hole 3 Spindle 4 Spindle chuck 7 Bar material 22 Free rotation chuck 32 Workpiece 41 Opposing axis chuck 42 Drive motor A Lathe machining area

Claims (4)

[Claims] 1. A bar material (7) is machined in the shaft center of the spindle (3).
In a lathe provided with a through hole (2) that serves as a passage for feeding into (A), a free-running chuck (4) that faces the spindle chuck (4) mounted at the tip of the spindle on the axis of the spindle (3). 22) is provided, and this free rotation chuck (22) is
(3) Can be driven and moved in the axial direction, and the machining area of the lathe (A)
A lathe that is provided so that it can be retracted from. 2. The spindle chuck (4) mounted on the spindle (3) by feeding the tip of the bar material (7) into the processing area (A) by a predetermined length through a through hole (2) provided in the spindle (3) and Grasp the bar material (7) with the free-rotating chuck (22) that has advanced to the position facing the tip of the bar material (7) and rotate the spindle (3) to rotate the spindle chuck (4).
The free end of the bar material (7) between it and the above-mentioned free-rotating chuck (22), open the spindle chuck (4) to retract the bar material (7), and move the free-rotating chuck (22) to the spindle side. After moving a predetermined amount, the spindle chuck (4) is closed to grasp the cutting side end of the workpiece (32) separated from the bar material (7), and then the free rotating chuck (22) is attached to the workpiece (32). ) Of the lathe according to claim 1, characterized in that the work piece (32) is turned by rotating the main shaft (3) after the work piece (32) is withdrawn from the working area (A). Processing method. 3. The spindle chuck (4) mounted on the spindle (3) by feeding the tip of the bar material (7) into the processing area (A) by a predetermined length through a through hole (2) provided in the spindle (3) and Hold the bar material (7) with the opposing shaft chuck (41) that has advanced to the position facing the tip of the bar material (7), and rotate the spindle (3) and the opposing shaft synchronously to rotate the spindle chuck (4) and the opposing shaft. Bar material (7) with chuck (41)
Cut off the tip of the bar, open the spindle chuck (4) and open the bar material (7).
Of the workpiece (32) separated from the bar material (7) by retracting the counter shaft chuck (41) to the spindle side by a predetermined amount and then closing the spindle chuck (4). Then, the opposing shaft chuck (41) is detached from the tip of the workpiece (32) and retracted from the processing area (A), and then the spindle (3)
A method for processing a bar material in a two-spindle facing lathe, which comprises rotating the workpiece to rotate the workpiece (32). 4. The bar material (7) has a predetermined amount of processing area (A) at the tip thereof.
The bar material (7) with the spindle chuck (4) and the outer shape of the tip of the bar material (7) is processed.
The free rotation chuck (22) or the counter shaft chuck (4
1), facing the free-rotating chuck (22) or the opposing shaft chuck (41) to grip the tip of the bar material after the outer shape processing, and then perform the parting operation according to claim 2 or 3. The method for processing a bar material according to claim 2 or 3, characterized in that.