JP2844027B2 - Machining method for female thread using lathe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for machining a female screw portion using a lathe.

[0002]

2. Description of the Related Art As a conventional lathe, there is known a lathe having two main spindles, that is, a main spindle and a sub spindle, which are coaxially opposed to each other. This type of lathe is disposed between both spindles, is capable of reciprocating in the front-rear direction and the left-right direction, and has a turret equipped with an indexable tool,
The first workpiece to be attached to the main spindle or the second workpiece to be attached to the sub-spindle can be machined by the indexed tool.

[0003]

However, in such a conventional lathe having two main spindles, the first workpiece to be mounted on the main spindle and the second workpiece to be mounted on the sub-spindle are simultaneously placed on the lathe. There is a disadvantage that it is substantially impossible to machine the female screw portion. That is, theoretically, the turret and sub-spindle on which a pair of taps are mounted are moved forward at different speeds in the same direction in synchronization with each other, and at the same time, the main spindle and the sub-spindle are rotationally driven, so that the second spindle mounted on the main spindle is rotated. It is possible to simultaneously machine female threads on one workpiece and the second workpiece mounted on the sub-spindle. However, when the main spindle and the sub-spindle are rotated in the opposite directions to the forward movement when returning after machining, the timing does not match, and a high-precision female screw portion cannot be machined on a pair of workpieces. This is because, for example, the main spindle and the sub-spindle reach a predetermined reverse rotation speed when shifting from forward movement to reverse movement due to a characteristic difference between the rotation drive motor of the main spindle and the rotation drive motor of the sub-spindle. This seems to be due to differences in time, manufacturing errors in turrets and other components, and the like.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional technical problem, and has a structure in which a first cylindrical member is mounted and a first rotary drive motor is provided. A main spindle, which is rotatably driven, and which is arranged coaxially with the main spindle, has a second tubular member attached thereto, and is capable of reciprocating in the front-rear direction by driving the first linear driving device; The sub-spindle, which is rotationally driven by a drive motor, is disposed between the opposed cylindrical members, and can be reciprocated in the front-rear direction by driving the second linear driving device. A first cylindrical member attached to the main spindle and a second cylindrical member attached to the sub-spindle;
A method of machining a female thread portion by a lathe for simultaneously machining a female thread portion with a cylindrical member, comprising: a space between a first tap and a first cylindrical member facing each other; a second tap and a second cylindrical member facing each other; With the main spindle and sub-spindle rotated at the same speed and in the same direction or in the opposite direction, the turret is advanced toward the main spindle at a constant speed, and the sub-spindle is turned toward the turret. To advance at a speed twice as high as the constant speed, and simultaneously machine the female threads on both tubular members. After the machining of both the female threads, rotate the sub-spindle and the main spindle at the same speed and in the opposite direction to the forward movement. At the same time, when the turret and the sub-spindle are moved backward at the same speed in a direction opposite to that at the time of forward movement, and the female screw portions are simultaneously formed on the first tubular member and the second tubular member. The start of driving of the first linear drive device for reverse drive of the drive start and the sub spindle of the second rotary driving motor for rotating the reverse sub-spindle,
A female screw portion formed by a lathe that delays by a predetermined time so as to match timing with the start of driving of the first rotary drive motor for rotating the main spindle in the reverse direction and the start of driving of the second linear drive device for driving the turret backward. It is a processing method.

[0005]

After the machining of both female threads is completed, the second linear drive device and the first linear drive device are driven to retract the turret and the sub-spindle, and the first and second taps are removed from both tubular members. Remove it. At this time, both the main spindle and the sub-spindle are rotated in the opposite direction to the forward rotation. For example, the main spindle and the sub-spindle are rotated in the same direction by the first rotation drive motor and the second rotation drive motor. The return operation of the sub-spindle occurs quickly due to the difference in the time required to reach the number, the production error in the turret or the like, and the female thread formed in the second cylindrical member is damaged. become.

Therefore, immediately after the machining of the two internal thread portions, the first
Driving the rotary drive motor and the second rotary drive motor to rotate the main spindle and the sub-spindle at the same speed in the direction opposite to the forward direction, and to drive the second linear drive device and the first linear drive device; When the turret and the sub-spindle are moved backward at the same ratio of speed in the opposite direction to the forward movement and the first and second taps are removed from the first and second tubular members, the second rotary drive motor is used. When the main spindle is driven forward by the first rotary drive motor, the start of driving the sub-spindle in the direction opposite to that of the forward drive and the start of driving of the first linear drive device for driving the sub-spindle in reverse. Is delayed by a predetermined time from the start of driving to rotate in the reverse direction and the start of driving of the second linear driving device that drives the turret backward.

In this way, the timing of the reverse drive of the turret and the reverse rotation of the main spindle is matched with the timing of the reverse drive of the sub-spindle and the reverse rotation of the sub-spindle. Thus, the first tap and the second tap are extracted from the first tubular member and the second tubular member in synchronization.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 show one embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes a main spindle. The main spindle 1 has a first cylindrical member 24 coaxially attached to a grip portion, and a belt 2 driven by a first rotation drive motor 2.
It can be driven to rotate forward and backward through 0. Reference numeral 4 denotes an encoder for detecting the rotation speed of the main spindle 1.

A sub-spindle 5 is arranged so as to face the main spindle 1 so as to coincide with the axis. The sub-spindle 5 has a second cylindrical member 25 coaxially attached to a gripping portion, and can be driven to rotate forward and reverse by a second rotation drive motor 7 via a belt 21. Further, the sub-spindle 5 and the second rotary drive motor 7 are driven by the first linear driving device 8 in the front-rear direction (the arrow Z) which is the axis direction of the sub-spindle 5.
Direction). First linear drive 8
Is constituted by a ball screw 8a, a reduction gear unit 8b, and a servomotor 8c, and the sub-spindle 5 and the second rotary drive motor 7 are integrally formed along a guide 9 by forward and reverse rotation drive of the servomotor 8c. It is driven back and forth.

A turret 10 capable of reciprocating in the front-rear direction (Z-axis direction) and the left-right direction (X-axis direction) is disposed between the spindles 1 and 5. That is, turret 1
0 indicates that reciprocation in the front-rear direction can be performed by the second linear drive device 11 and reciprocation in the left-right direction can be performed by the third linear drive device 12. Second linear drive 1
Reference numeral 1 denotes a ball screw 11a, a reduction gear unit 11b, and a servomotor 11c. The turret 10 is guided by rotation of the servomotor 11c in forward and reverse directions.
3 and is driven back and forth. Third linear drive 1
2 is constituted by a ball screw 12a, a reduction gear unit 12b, and a servomotor 12c, and the turret 10 is guided 1 by a forward / reverse rotation drive of the servomotor 12c.
4 are reciprocated right and left.

Further, the turret 10 includes an indexing device 15
A plurality of tools attached at predetermined intervals in the circumferential direction of the turret 10 can be indexed by both spindles 1, 5
It can be appropriately arranged between them. As the tool, a first tap 16 and a second tap 17 shown in FIGS. 1 and 4, a parting-off tool 22 shown in FIG. 2, and tools 26 and 27 shown in FIG. 3 are attached. The first tap 16 and the second tap 17 and the cutting tools 26 and 27 are coaxially mounted on both front and rear sides of the turret 10.

Next, using the lathe having the above structure, the first cylindrical member 24 attached to the main spindle 1 and the second cylindrical member 25 attached to the sub-spindle 5 are simultaneously screwed into the female thread 2.
Female threaded portions 24a, 2 formed by a lathe processing 4a, 25a
The processing method of 5a will be described. This first tubular member 2
The fourth or second cylindrical member 25 is a material of an adjuster nut used for the automatic clearance adjustment device of the vehicle brake device, and is processed from one cylindrical member 18 shown in FIG. , 25a are formed with reverse threads.

First, each end of one tubular member 18 is gripped by each gripping portion of the main spindle 1 and the sub spindle 5. In this state, the driving of the lathe is started, and the second cylindrical member 2 to be used on one of the left and right sides in the vehicle width direction of the vehicle is determined by the parting tool 22 determined by the indexing device 15.
The identification groove 2 shown in FIGS.
8 is formed, the outer surface is finished, and then the center is cut to form a first tubular member 24 and a second tubular member 25. Thereafter, the sub spindle 5 and the turret 10 are returned and indexed.

As shown in FIG. 3, a pair of bytes 26, 27
And chamfered portions 24b and 25b shown in FIGS. 5 and 6 are formed on the opposite end surfaces of both tubular members 24 and 25. At that time, the turret 10 is first advanced, and one of the cutting tools 26
To form a chamfered portion 24b in the first tubular member 24,
Next, a chamfered portion 25b is formed on the second tubular member 25 by the other cutting tool 27. When the double-sided portions 24b and 25b are formed, the turret 10 and the sub spindle 5 are returned.

Next, as shown in FIGS. 1 and 4, the first tap 16 and the second tap 17 are indexed,
The female screw portions 24a and 25a are simultaneously formed on the opposing ends of the fourth and fourth ends. At this time, the distance between the first tap 16 and the first tubular member 24 and the distance between the first tap 16 and the first tubular member 24 and the second tap 17 and the second The main spindle 1 and the sub-spindle 5 are rotated at the same speed and in the same direction by matching the interval with the cylindrical member 25. In this state, the second linear driving device 11 is driven to direct the turret 10 toward the main spindle 1 at a constant speed.
At the same time, the first linear driving device 8 is driven to move the sub spindle 5 toward the turret 10 at a speed twice as high as the constant speed. The female screw part 24a composed of a left-hand thread and the female screw part 25a composed of a right-hand thread are simultaneously processed.

When the machining of both female screw portions 24a and 25a is completed, the second linear drive device 11 and the first linear drive device 8
To move the turret 10 and the sub-spindle 5 with the arrow A
The first tap 16 and the second tap 17 are withdrawn from the tubular members 24 and 25 by being retracted in the opposite direction. At this time, the main spindle 1 and the sub-spindle 5 are both rotated in the opposite direction to the forward direction. For example, the main spindle 1 and the sub-spindle are rotated by the first rotary drive motor 2 and the second rotary drive motor 7. 5 differ in the time required to reach the same reverse speed, turret 1
The return operation of the sub-spindle 5 occurs quickly due to a manufacturing error or the like, and the female screw portion 25a formed on the second cylindrical member 25 is damaged. Such a situation occurs even when the first rotation drive motor 2 and the second rotation drive motor 7 are simultaneously instructed to perform reverse rotation drive.

Therefore, immediately after the machining of the female screw portions 24a and 25a, the first rotary drive motor 2 and the second rotary drive motor 7 are driven to rotate the main spindle 1 and the sub spindle 5 by the same rotation in the direction opposite to the forward direction. And the second linear driving device 11 and the first linear driving device 8 are driven to move the turret 10 and the sub-spindle 5 backward at the same ratio of speed in the reverse direction to that of the forward movement. Tap 16
When the second tap 17 is removed from the first tubular member 24 and the second tubular member 25, the second rotary drive motor 7 starts the sub-spindle 5 in a direction opposite to the direction in which the sub-spindle is advanced. When the first linear drive device 8 for driving the spindle 5 backward is started, the first rotary drive motor 2 starts driving the main spindle 1 to rotate in the opposite direction to the forward direction, and the turret 10 is driven backward. It is delayed by a predetermined time from the start of driving of the second linear driving device 11.

In this manner, the timing of the reverse drive of the turret 10 and the reverse rotation drive of the main spindle 1, the reverse drive of the sub spindle 5 and the sub spindle 5
With the timing of the reverse rotation drive of Thus, the first tap 16 and the second tap 17 are extracted from the first tubular member 24 and the second tubular member 25 in synchronization. When the first tap 16 and the second tap 17 are extracted from the first tubular member 24 and the second tubular member 25, the state is returned to the processing start state.

The second rotary drive motor 7 and the first
The delay operation of the sub spindle 5 by the linear driving device 8 is as follows.
In practice, this is done by incorporating a timer into a micro computer that controls the lathe. In the above embodiment, the main spindle 1 and the sub-spindle 5 are driven to rotate in the same direction, and the female screw 24a of the first cylindrical member 24 and the female screw 25a of the second cylindrical member 25 are reversed. Direction, the main spindle 1 and the sub-spindle 5 are driven to rotate in opposite directions, and the female screw portions 24a, 24
It is also possible to form a screw in the same direction on 5a.

【The invention's effect】

As can be understood from the above description, according to the method of machining a female screw portion by a lathe according to the present invention,
In a lathe having two main shafts, the timings of the first tap and the second tap with respect to the first tubular member and the second tubular member at the time of reversing coincide with each other. The female thread can be accurately machined. As a result, work efficiency is remarkably improved as compared with a case where both female screw portions are machined as separate steps.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a lathe according to one embodiment of the present invention.

FIG. 2 is a view showing a parting-off process.

FIG. 3 is a view similarly showing a chamfering step.

FIG. 4 is a view showing a process of forming a female screw portion in the same manner.

FIG. 5 is a cross-sectional view showing the first cylindrical member.

FIG. 6 is a cross-sectional view showing the second cylindrical member.

[Explanation of symbols]

1: Main spindle 2: First rotation drive motor, 5:
Sub-spindle, 7: second rotary drive motor, 8: first linear drive, 10: turret, 11: second linear drive, 12: third linear drive, 15: indexing device, 1
6: first tap, 17: second tap, 18: cylindrical member,
24: 1st cylindrical member, 24a: female screw part, 25: 2nd cylindrical member, 25a: female screw part.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-2-24023 (JP, A) JP-A-63-34018 (JP, A) JP-A-59-88203 (JP, A) (58) Investigation Field (Int.Cl. ⁶ , DB name) B23G 1/20 B23G 3/00

Claims (1)

(57) [Claims] 1. A main spindle to which a first tubular member is attached and which is driven to rotate by a first rotation drive motor;
It is arranged coaxially with the main spindle, has a second tubular member attached thereto, is capable of reciprocating in the front-rear direction by driving the first linear drive device, and is rotationally driven by a second rotary drive motor. The first and second taps are coaxially mounted on the front and rear sides of the sub-spindle, and are disposed between the sub-spindle and the opposed cylindrical members, and can be reciprocated in the front-rear direction by driving the second linear driving device. A method for machining a female screw portion by a lathe, wherein the female screw portion is formed on a first cylindrical member attached to a main spindle and a second cylindrical member attached to a sub-spindle at the same time. The main spindle and the sub-spindle are rotated at the same speed and in the same direction or in the opposite direction when the distance between the second spindle and the first cylindrical member is matched with the distance between the second tap and the second cylindrical member. ,Previous The turret is advanced toward the main spindle at a constant speed, and the sub-spindle is advanced toward the turret at twice the speed of the constant speed. After machining, the sub-spindle and the main spindle are rotated at the same speed and in the opposite direction to that at the time of forward movement, and the turret and the sub-spindle are moved backward at the same speed in the direction opposite to that at the time of forward movement, so that the first tubular member and the second When machining the female screw portion on the cylindrical member at the same time, when the drive of the second rotary drive motor for rotating the sub-spindle in the reverse direction is started and when the drive of the first linear drive device for driving the sub-spindle backward is started, the main spindle is moved. At the start of driving of the first rotary drive motor for rotating in the reverse direction and at the start of driving of the second linear drive device for driving the turret backward. Processing method of the internal thread portion by lathe, characterized in that delaying by a predetermined time so as to match the timing with.