JP2005305512A - Thread rolling method of screw device, ball screw device, and roller screw device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the thread rolling method of a screw device by which the visual observation of an operator and the measurement of time required for the thread rolling are unnecessary and the completion of the thread rolling is finely detected without being affected by the error of the entire length of a shaft base stock and the difference of elongation by the variation of materials, a ball screw device and a roller screw device. <P>SOLUTION: By this thread rolling method of the screw device, a desired shape is formed on the outer periphery of the shaft base stock 28 by thread rolling with dies 14, 19 by holding the base stock 28 between a pair of the dies 14, 19 while rotating them. In the thread rolling method of the screw device, load F which is applied to at least either of the dies 14, 19 in the thread rolling of the base stock 28 is detected and this detected load F is compared with a preset specified value K1. When the detected load F is smaller than the specified value K1, the thread rolling of the base stock 28 with the dies 14, 19 is completed by releasing the holding of the base stock 28 with the dies 14, 19. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rolling method of a screw device, a ball screw device, and a roller screw device, and in particular, by inserting a shaft material while rotating the die, the ball of the ball screw device and the roller screw device are inserted into the shaft material with the die. The present invention relates to a ball groove on which a roller of the roller rolls, a rolling method of a screw device device that forms the roller groove by rolling, a ball screw device, and a roller screw device.

Many of the screw shafts constituting the ball screw device perform rolling processing on a long shaft material with a rolling device. According to this rolling apparatus, the shaft material is fed into the pair of dies while the pair of dies are rotated, thereby rolling the ball screw with the pair of dies on the shaft material.
As this rolling apparatus, one that rolls a ball screw on a long workpiece with high accuracy has been proposed (see, for example, Patent Documents 1 to 3).
JP 2001-47170 JP 2001-269741 A Japanese Patent Laid-Open No. 10-180385

The ball screw rolling device disclosed in Japanese Patent Application Laid-Open No. 2001-47170 includes a sensor that detects a change in the pressing amount of a die during rolling of a shaft material with a pair of dies. Based on the change in the pressing amount of the die detected by this sensor, the position of the die is corrected and the processing surface position of the die is kept constant.
This makes it possible to roll the ball screw on the shaft material with high accuracy.

In addition, the ball screw rolling device disclosed in Japanese Patent Application Laid-Open No. 2001-269741 includes a plurality of support bushes that support the shaft material, and a support blade that supports the rolling lower diameter portion of the shaft material so as to be retractable. The shaft material supported by the support bush is passed between a pair of dies while rotating, and a ball screw is rolled into the shaft material.
At this time, it is possible to cope with a deformed shaft material by retracting the support blade in accordance with the shape of the shaft material.

  Further, the ball screw rolling device disclosed in Japanese Patent Laid-Open No. 10-180385 includes a hydraulic cylinder that moves the left headstock, and a load switch in the middle of the oil circuit of the hydraulic cylinder. By actuating this load switch, it becomes possible to detect the start of rolling into the shaft material.

By the way, according to the ball screw rolling device of the above publication, when rolling a ball screw on a shaft material, it is necessary for the operator to visually check when the rolling process is completed and stop the ball screw rolling device. There is.
Alternatively, the time required for the rolling process of the ball screw is measured in advance (that is, teaching is performed), and a timer is set in accordance with the measured required time, so that the ball screw rolling is completed when the rolling process is completed. The production equipment needs to be stopped.

However, in the conventional ball screw rolling apparatus, in order to stop the apparatus when the rolling process is completed, it is necessary for an operator to visually confirm the completion of the rolling process.
On the other hand, in order to detect the completion of the rolling process with a timer, it is necessary to measure in advance the time required for the rolling process.
Furthermore, there is a possibility that the timing of completion of the rolling process may be shifted due to an error in the total length of the shaft material or a difference in elongation due to material variations.

  The present invention has been made in view of the above-described problems, and its purpose is not to require visual inspection by the operator or measurement of the time required for the rolling process, and to reduce the total length error of the shaft material or the material. An object of the present invention is to provide a rolling method of a screw device, a ball screw device, and a roller screw device that can satisfactorily detect the completion of the rolling process without being affected by the difference in elongation due to variations.

  1) In order to achieve the above-described object, the rolling process method of the screw device of the present invention includes a pair of dies rotating the pair of dies to sandwich the shaft material, so that In a rolling method in which a ball groove in which a ball of a ball screw device rolls is formed by rolling, a load applied to at least one of the pair of dies during the rolling of the shaft material is detected, and the detected load Is compared with a preset set value, and when the detected load becomes smaller than the set value, or during the rolling process of the shaft material, the cutting position for at least one shaft material of the pair of dies Detecting a displacement from a normal rolling processing position, comparing the detected displacement with a preset set value, and when the detected displacement becomes larger than the set value, the pair of dies To release the nipping of the shaft blank with is characterized in that to complete the rolling of the shaft blank by the pair of dies.

  2) Further, in the rolling method of the screw device of the present invention, the roller of the roller screw device is rolled on the outer periphery of the shaft material by the pair of dies while sandwiching the shaft material while rotating the pair of cylindrical dies. In a rolling method of a screw device that forms a moving roller groove by rolling, a load applied to at least one of the pair of dies during rolling of the shaft material is detected, and the detected load is Compared to the set value, when the detected load is smaller than the set value, or during the rolling process of the shaft material, regarding the cutting position for at least one shaft material of the pair of dies, normal The displacement with the rolling processing position is detected, the detected displacement is compared with a preset set value, and when the detected displacement becomes larger than the set value, the shaft element by the pair of dies is used. To release the nipping of the is characterized in that to complete the rolling of the shaft blank by the pair of dies.

3) The ball screw device of the present invention is characterized by being processed by the rolling method of the screw device described in 1).
4) Further, the roller screw device of the present invention is characterized by being processed by the rolling method of the screw device described in 2).

Here, when the shaft material is rolled at a fixed position through the pair of dies, there is a characteristic that the rolling load is reduced when the shaft material is just rolled.
Therefore, the present invention uses this characteristic to control the rolling process using a die.
That is, in the rolling method of the screw device of the present invention, the load applied to the die during the rolling process of the shaft material is detected, and when this detected load becomes smaller than a preset set value, the shaft material by the die is used. We decided to complete the rolling process.

This eliminates the need for the operator to visually confirm the completion of the rolling process. Alternatively, it is not necessary to measure the time required for the rolling process in advance and set a timer according to the measured time required.
In addition, there is no possibility that the timing of completion of the rolling process is shifted due to an error in the total length of the shaft material or a difference in elongation due to material variations.

According to the present invention, it is possible to obtain an effect that the operator's visual observation is unnecessary, and the trouble of measuring the time required for the rolling process in advance can be saved.
Furthermore, the effect that the completion of the rolling process can be satisfactorily detected without being affected by an error in the total length of the shaft material or a difference in elongation due to variations in the material can be obtained.
Moreover, it becomes easy to process shaft materials having different overall lengths that are processed using the same die.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view showing a rolling processing apparatus for carrying out the rolling processing method for a screw device according to the first embodiment of the present invention, and FIG. 2 shows a load applied to the die during the rolling processing of the first embodiment. Graph, FIG. 3 is a flowchart showing the rolling method of the screw device of the first embodiment, FIG. 4 is a diagram for explaining the state before the shaft material is sandwiched in the rolling method of the screw device of the first embodiment, FIG. 5 is a diagram for explaining a rolling process start state in the rolling method for the screw device according to the first embodiment, and FIG. 6 is a diagram for explaining a rolling process completed state in the rolling method for the screw device according to the first embodiment. It is.

As shown in FIG. 1, the rolling processing apparatus 10 of the first embodiment has a fixed bracket 12 attached to a stationary headstock 11, and a cylindrical fixed die 14 is attached to the fixed bracket 12 via a support shaft 13. The support shaft 13 is connected to a fixed drive mechanism 15, and a movable bracket 17 is attached to the movable head stock 16. A cylindrical movable die 19 is attached to the movable bracket 17 via a support shaft 18. The support shaft 18 is connected to the movable drive mechanism 21, the feed mechanism 22 is connected to the movable head stock 16, and the feed mechanism 22 is attached to the fixed wall 23.
The drive mechanism 15 and the drive mechanism 21 include a drive motor and a speed reducer, respectively.

  Further, the rolling processing apparatus 10 attaches the movable bracket 17 to the movable side headstock 16 so that the movable bracket 17 can be moved in the left-right direction with a slight gap, and a load cell (load detection unit) is attached to the movable side headstock 16. ) 25 and a load applied to the movable die 19 can be detected by the load cell 25 by abutting the left end portion of the load cell 25 to the movable bracket 17.

In addition, the rolling processing apparatus 10 receives the detected load detected by the load cell 25 by the control unit 26, and the detected load is compared with a predetermined value (set value) set in advance by the control unit 26. When it becomes smaller than the specified value, the feed mechanism 22 is controlled to retract the movable die 19 from the rolling position to the standby position.
The rolling processing apparatus 10 includes a specified value input unit 27 for inputting a specified value to the control unit 26.
In addition, the site | part which provides the load cell 25 is not restricted to the main spindle 16 of the movable side, It is also possible to provide in other sites. In short, what is necessary is just to provide in the site | part which detects the load applied to the movable die 19. FIG.

  The feed mechanism 22 includes a servo motor as an example. By driving the servo motor, the pushing shaft (not shown) of the servo motor protrudes toward the fixed die 14 and the movable die 19 faces the fixed die 14. Thus, it is possible to move to the rolling processing position, and to retract from the rolling processing position to the standby position.

Although the load cell 25 is illustrated as the load detection unit, the load cell 25 can be replaced with, for example, a hydraulic pressure detection device provided on the pushing shaft of the feed mechanism 22, and the torque of the servo motor of the feed mechanism 22 can be detected. It is also possible to detect with.
Further, instead of the detection method of the load cell 25, it is also possible to detect by the load or torque applied to the rotation input shaft of the fixed die 14 or the movable die 19.

  In addition, the constant pressure / through rolling has a characteristic that the cutting positions of the fixed die 14 and the movable die 19 move in the cutting direction just before the rolling process is completed. Therefore, by detecting the displacement of the fixed die 14 and the movable die 19 with respect to the normal rolling processing position, it is possible to obtain the same effect as the effect of detecting the load with the load cell 25 or the like.

  According to the rolling processing apparatus 10, the fixed die 14 is rotated by the fixed drive mechanism 15, and the movable die 19 is rotated by the movable drive mechanism 21. Furthermore, the movable die 19 is moved to the machining position by moving the movable head stock 16 in the direction of the arrow by the feed mechanism 22.

  As a result, the shaft material (work) 28 is sandwiched between the fixed die 14 and the movable die 19 while rotating the fixed die 14 and the movable die 19, so that the fixed die 14 and the movable die 19 are placed on the outer periphery of the shaft material 28. A ball groove and a ball screw in which a ball of the ball screw device rolls are formed by rolling.

When rolling the ball groove or roller groove on which the ball of the ball screw device or the roller of the roller screw device rolls on the outer periphery of the shaft material 28 with the fixed die 14 and the movable die 19, the fixed die 14 and the movable die 19 are moved. A load F (kN) is applied.
Here, the load applied to the fixed die 14 and the movable die 19 and the rolling state of the shaft material 28 will be described based on the graph of FIG.

In the graph shown in FIG. 2, the vertical axis represents the load F (kN) applied to the fixed die 14 and the movable die 19, and the horizontal axis represents time.
As shown in the graph of FIG. 2, when the pinching of the shaft material 28 is started between the fixed die 14 and the movable die 19 at T1, the load F (kN) starts to act on the fixed die 14 and the movable die 19.

When the pinching of the shaft material 28 is completed between the fixed die 14 and the movable die 19 at T2, the load F (kN) applied to the fixed die 14 and the movable die 19 is maximized.
By rolling the shaft material 28 between the fixed die 14 and the movable die 19, rolling processing is started on the shaft material 28.
Thereafter, the shaft material 28 is continuously rolled by the fixed die 14 and the movable die 19, so that the load F (kN) applied to the fixed die 14 and the movable die 19 is kept substantially constant.

At T3, when the rolling process of the shaft material 28 is completed, the load F (kN) applied to the fixed die 14 and the movable die 19 decreases.
Therefore, when the load F (kN) decreases, the load F is set to a specified value (set value) K1 (kN), and this set difference K1 is input from the specified value input unit 27 (see FIG. 1) to the control unit 26. To do.

Thus, when the shaft material 28 is rolled at a fixed position and through the fixed die 14 and the movable die 19, the rolling load is reduced when the rolling of the shaft material 28 is completed (T3). is there.
Therefore, the rolling process by the fixed die 14 and the movable die 19 is controlled using this characteristic.
The control method of 1st Embodiment is demonstrated based on the flowchart of FIG. 3, and FIGS. 4-6.

In ST10 shown in FIG. 3, the rolling processing apparatus 10 is set to an operating state, and a shaft material feed mechanism (not shown) is driven.
With this shaft material feed mechanism, the shaft material 28 is fed in the direction of arrow A as shown in FIG.
In ST11, when the tip 28A of the shaft material 28 reaches the rolling processing position (position shown in FIG. 4), the tip 28A of the shaft material 28 is detected by a detecting means (not shown).

  In ST12, based on the detection signal of the rolling processing position, the fixed die 14 is rotated by the fixed driving mechanism 15 of the rolling processing apparatus 10 shown in FIG. 4, and the movable die 19 is rotated by the movable driving mechanism 21. Rotate.

In ST13, the movable die 19 is moved to the machining position by moving the movable head stock 16 in the arrow B direction by the feed mechanism 22 shown in FIG.
Then, as shown in FIG. 5, the shaft material 28 is sandwiched between the fixed die 14 and the movable die 19.

In ST 14, the load F (kN) starts to act on the fixed die 14 and the movable die 19 by sandwiching the shaft material 28 between the fixed die 14 and the movable die 19.
The load F (kN) is detected by the load cell 25 and the load F (kN) detected by the load cell 25 is transmitted to the control unit 26.

In ST15, the control unit 26 compares the detected load F with a preset specified value K1.
As a result of comparison, when the detected load F is less than the specified value K1, the pinching of the shaft material 28 by the fixed die 14 and the movable die 19 is not completed.
Therefore, the process of feeding back to ST13 and sandwiching the shaft material 28 between the fixed die 14 and the movable die 19 is continued.
On the other hand, when the detected load F is equal to or greater than the specified value K1, since the pinching of the shaft material 28 by the fixed die 14 and the movable die 19 has been completed, the step ST16 is performed.

  In ST16, as shown in FIG. 5, the shaft material 28 is fed in the direction of arrow A. Therefore, when the pinching of the shaft material 28 is completed, the rolling process of the shaft material 28 is started.

In ST17, the detection load F detected by the load cell 25 is received by the control unit 26, and the control unit 26 compares the detection load F with a preset specified value K1.
As a result of the comparison, when the detected load F exceeds the specified value K1, the rolling process of the shaft material 28 is continued by feeding back to ST16.
On the other hand, when the detected load F is less than the specified value K1, as shown in FIG. 6, the rolling process of the shaft material 28 is completed. In this case, step ST18 is performed.

In ST18, a retract signal is transmitted from the control unit 26 to the feed mechanism 22, and a stop signal is transmitted to the fixed drive mechanism 15 and the movable drive mechanism 21.
That is, that the detected load F is less than the specified value K1 indicates that T3 shown in the graph of FIG. 2 has been reached. At this time, a retreat signal is transmitted from the control unit 26 to the feed mechanism 22, and a stop signal is transmitted to the fixed drive mechanism 15 and the movable drive mechanism 21.

By transmitting a retract signal from the control unit 26 to the feed mechanism 22, the feed mechanism 22 shown in FIG. 6 is driven to move the movable die 19 in the direction of arrow C from the rolling position to the retracted position.
Thereby, the pinching of the shaft material 28 by the fixed die 14 and the movable die 19 is released.
Further, a stop signal is transmitted from the control unit 26 to the driving mechanisms 15 and 21 on the fixed side and the movable side. The driving mechanisms 15 and 21 on the fixed side and the movable side are stopped, and the rotation of the fixed die 14 and the movable die 19 is stopped. Thereby, the rolling process of the shaft raw material 28 by the rolling processing apparatus 10 is completed.

As described above, when the rolling process of the shaft material 28 is performed, the rolling process of the shaft material 28 is controlled by using the characteristic that the rolling load F decreases when the rolling process is completed (T3). There is no need for the operator to visually confirm the completion of the rolling process.
Alternatively, it is not necessary to measure the time required for the rolling process in advance and set a timer according to the measured time required.
In addition, it is possible to prevent the rolling processing completion timing from deviating due to an error in the total length of the shaft material 28 or a difference in elongation due to material variation.

Furthermore, as an application, a signal indicating completion of the rolling process of the shaft material 28 is sent to a part having a loading function or another machine, so that the new shaft material 28 is moved to a position where the rolling process can be performed, and a new If the shaft material 28 is started, a plurality of shaft materials 28 can be continuously and automatically processed.
In addition, using the same die (fixed die 14 and movable die 19), it becomes easy to process various shaft materials 28 having different overall lengths.

Next, a second embodiment will be described.
In the graph shown in FIG. 7, the vertical axis indicates the position P (mm) of the movable die 19, and the horizontal axis indicates time.
As shown in the graph of FIG. 7, at T1, the movable die 19 starts to move from the position P1 toward the fixed die 14.

  At T <b> 2, the movable die 19 reaches the position P <b> 2, and the shaft material 28 is sandwiched between the fixed die 14 and the movable die 19. Thus, the shaft material 28 is rolled by the fixed die 14 and the movable die 19.

When the rolling process of the shaft material 28 by the fixed die 14 and the movable die 19 is completed at T3, the position P of the movable die 19 becomes smaller than a preset specified value (set value) K2 (mm).
Therefore, the specified separation K2 is input from the specified value input unit 27 (see FIG. 1) to the control unit 26.

As described above, when the shaft material 28 is rolled at a fixed position and through the fixed die 14 and the movable die 19, the position P of the movable die 19 is preliminarily set when the rolling of the shaft material 28 is completed (T3). There is a characteristic that becomes smaller than the set specified value K2.
Therefore, the rolling process by the fixed die 14 and the movable die 19 is controlled using this characteristic.
The control method of 2nd Embodiment is demonstrated based on the flowchart of FIG. 8, and FIGS. 9-10.

In ST20 shown in FIG. 8, the rolling processing apparatus 10 is set in an operating state, and a shaft material feed mechanism (not shown) is driven.
With this shaft material feed mechanism, the shaft material 28 is fed in the direction of arrow A as shown in FIG.
In ST21, when the tip 28A of the shaft material 28 reaches the rolling position (position shown in FIG. 9), the tip 28A of the shaft material 28 is detected by a detection means (not shown).

In ST22, a rolling start signal is transmitted to the rolling processing apparatus 10 based on the detection signal of the rolling processing position.
The fixed die 14 is rotated by the fixed drive mechanism 15 of the rolling processing apparatus 10 shown in FIG. 9 and the movable die 19 is rotated by the movable drive mechanism 21.

In ST23, the movable die 19 is moved to the machining position by moving the movable head stock 16 in the arrow B direction by the feed mechanism 22 shown in FIG.
As a result, as shown in FIG. 10, the shaft material 28 is sandwiched between the fixed die 14 and the movable die 19, and the rolling process of the shaft material 28 is started.

In ST24, the position P of the movable die 19 is detected by, for example, a position detection scale (position detection unit) 29. The position P (mm) detected by the position detection scale 29 is transmitted to the control unit 26.
In the position detection scale 29, a magnet 29A is attached to the movable head stock 16, and a scale portion is attached to the base. Therefore, when the magnet 29 </ b> A moves integrally with the movable die 19, the position detection scale 29 detects the position at the position P of the movable die 19.

In ST25, the control unit 26 compares the detection position P with a preset specified value K2. That is, the displacement with the normal rolling process position is detected, and this detected displacement is compared with a preset specified value (set value) K2.
As a result of comparison, when the detected position P exceeds the specified value K2, that is, when the detected displacement becomes larger than the specified value, the rolling process of the shaft material 28 is continued by feeding back to ST23.
On the other hand, when the detection position P is less than the specified value K2, the rolling process of the shaft material 28 is completed as shown in FIG. 5, and the process of ST26 is performed.

In ST26, when the detection position P becomes less than the specified value K2, a retract signal is transmitted from the control unit 26 to the feed mechanism 22, and a stop signal is transmitted to the fixed drive mechanism 15 and the movable drive mechanism 21.
That is, that the detection position P is less than the specified value K2 indicates that T3 shown in the graph of FIG. 7 has been reached. At this time, a retreat signal is transmitted from the control unit 26 to the feed mechanism 22, and a stop signal is transmitted to the fixed drive mechanism 15 and the movable drive mechanism 21.

By transmitting a retract signal from the control unit 26 to the feed mechanism 22, the feed mechanism 22 is driven to move the movable die 19 in the direction of arrow C (see FIG. 5) from the rolling position to the retract position. Thereby, the pinching of the shaft material 28 by the fixed die 14 and the movable die 19 is released.
Further, a stop signal is transmitted from the control unit 26 to the driving mechanisms 15 and 21 on the fixed side and the movable side.

The driving mechanisms 15 and 21 on the fixed side and the movable side are stopped, and the rotation of the fixed die 14 and the movable die 19 is stopped. Thereby, the rolling process of the shaft raw material 28 by the rolling processing apparatus 10 is completed.
Thereby, according to the rolling method of the screw device of 2nd Embodiment, the effect similar to the rolling method of the screw device of 1st Embodiment can be acquired.

In the above embodiment, the example in which the shaft material is rolled by two dies, the fixed die 14 and the movable die 19, has been described, but the number of dies is not limited to two.
In the embodiment, the ball groove and the roller groove on which the ball of the ball screw device and the roller of the roller screw device roll are described as examples of the desired shape to be rolled on the peripheral surface of the shaft material 28. For example, the present invention can be applied to the processing of bolts and is not limited to this.

  In addition, the material, shape, size, form, number, location, etc. of the fixed die 14, the movable die 19, and the shaft material 28 exemplified in the above-described embodiment are arbitrary as long as they can achieve the present invention, and are limited. Not.

It is a side view which shows the rolling processing apparatus which enforces the rolling processing method of the screw apparatus of 1st Embodiment which concerns on this invention. It is a graph which shows the load concerning a die during rolling processing of a 1st embodiment. It is a flowchart which shows the rolling process method of the screw apparatus of 1st Embodiment. It is a figure explaining the state before pinching | interposing a shaft raw material in the rolling method of the screw device of 1st Embodiment. It is a figure explaining the rolling process start state in the rolling process method of the screw device of a 1st embodiment. It is a figure explaining the rolling processing completion state in the rolling processing method of the screw device of a 1st embodiment. It is a graph which shows the load concerning a die during rolling processing in the rolling processing method of the screw device of a 2nd embodiment concerning the present invention. It is a flowchart which shows the rolling process method of the screw apparatus of 2nd Embodiment. It is a figure explaining the state before pinching | interposing the shaft raw material in the rolling processing method of the screw device of 2nd Embodiment. It is a figure explaining the rolling process start state in the rolling process method of the screw device of 2nd Embodiment.

Explanation of symbols

10 Rolling processing equipment 14 Fixed dies (dies)
15 Drive mechanism on the fixed side 19 Movable dice (die)
21 Drive mechanism on movable side 22 Feed mechanism 25 Load cell (load detector)
26 Control unit 28 Shaft material 29 Position detection scale (position detection unit)
F Load (Detected load)
K1, K2 Specified value (set value)
P position (detection position)

Claims (4)

Rolling of a screw device that forms a ball groove in which a ball of a ball screw device rolls on the outer periphery of the shaft material by a pair of dies while sandwiching the shaft material while rotating a pair of cylindrical dies. In the processing method,
When a load applied to at least one of the pair of dies during the rolling process of the shaft material is detected, the detected load is compared with a preset set value, and the detected load becomes smaller than the set value. ,
Alternatively, during the rolling process of the shaft material, the displacement with respect to the normal rolling process position is detected with respect to the cutting position for at least one of the pair of dies, and the detected displacement is set in advance. When the detected displacement is larger than the set value compared with the value,
A rolling method of a screw device, wherein the pinching of the shaft material by the pair of dies is released, and the rolling process of the shaft material by the pair of dies is completed. Rolling of a screw device that forms a roller groove in which a roller of a roller screw device rolls on the outer periphery of the shaft material by a pair of dies while sandwiching the shaft material while rotating a pair of cylindrical dies. In the processing method,
When a load applied to at least one of the pair of dies during the rolling process of the shaft material is detected, the detected load is compared with a preset set value, and the detected load becomes smaller than the set value. ,
Alternatively, during the rolling process of the shaft material, the displacement with respect to the normal rolling process position is detected with respect to the cutting position for at least one of the pair of dies, and the detected displacement is set in advance. When the detected displacement is larger than the set value compared with the value,
A method for rolling a screw device, wherein the pinching of the shaft material by the pair of dies is released to complete the rolling process of the shaft material by the pair of dies.   A ball screw device processed by the rolling method of the screw device according to claim 1.   A roller screw device processed by the rolling method of the screw device according to claim 2.

Images