JP3565704B2 - Round die rolling device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a round die rolling device for rolling a screw, a worm, a serration, a spline, a gear, and the like using a rotating round die, and in particular, while controlling a processing torque acting on the round die during rolling. The present invention relates to a round die-type rolling device that rolls a peripheral surface and an axial direction of a work.
[0002]
[Prior art]
Conventionally, as a concept of a rolling device using a round die of this type, the concept shown in FIG. 6 is known. In this method, a pair of round dies 1a and 1b are moved toward the workpiece 3 while rotating, and rolling is performed by applying rolling pressure in the radial direction of the workpiece 3. The spindles 2a, 2b of the round dies 1a, 1b are controlled to rotate at a constant speed, and the movement of the spindles 2a, 2b is also controlled to maintain a constant pressure or speed.
[0003]
[Problems to be solved by the invention]
By the way, as shown in FIG. 6, when the rolling process is started, the normal dice force Fp and the tangential force Ft act on the round dies 1 a and 1 b on the contact surface with the work 3. In the conventional round die type rolling device, the main shafts 2a and 2b are controlled to rotate at a constant speed and to move at a constant pressure or speed. Both the load Fp and the machining torque T acting on the main shafts 2a, 2b of the round dies 1a, 1b fluctuate. In particular, the main shaft torque T during the rolling process shows a temporary peak that extremely increases during the rolling, and the main shaft torque T at this peak greatly affects the life of the dies 2a and 2b. Then, there is a problem that the life of the dice decreases as the peak value increases.
[0004]
Therefore, the present invention provides a round die-type rolling device capable of preventing the temporary increase in the processing torque acting on the main spindle of the round die during the rolling process, extending the life of the die, and performing the efficient rolling process. The purpose is to do.
[0005]
[Means for Solving the Problems]
That is, in order to solve the above-mentioned problem, a round die-type rolling device according to claim 1 of the present invention is a round die-type rolling device that forms a work by sandwiching a work with a set of round dies. A torque detecting means for detecting a working torque acting on the round die is provided, and at least one of the rotation speed of the round die and the moving speed of the round die is controlled so as to keep the working torque acting on the round die during rolling within a certain range. Features.
[0006]
Further, the round die-type rolling device according to claim 2 of the present invention includes a pair of die moving tables that pivotally support a pair of round dies, and the one pair of rolls around a rolling position of a work by the round dies. A beam shaft extending between two or more dies and a push-in mechanism for bringing the set of dies into close proximity to each other; A round-die rolling device configured to bear a reaction force generated between the pair of round dies by pressure on the beam shaft, and a torque detecting unit that detects a processing torque applied to the round die is provided, At least one of the number of revolutions of the round die and the moving speed of the round die is controlled so that the processing torque acting on the round die during rolling is kept within a certain range.
[0007]
The round die rolling device according to claim 3 of the present invention compares the detected torque value detected by the torque detecting means with a set torque value, and determines that the detected torque value is higher than the set torque value if the detected torque value is higher than the set torque value. While the rotational speed of the dice is increased, when the detected torque value is lower than the set torque value, the rotational speed of the round die is controlled to be decreased.
[0008]
Further, the round die rolling device according to claim 4 of the present invention compares the detected torque value detected by the torque detecting means with a set torque value, and when the detected torque value is higher than the set torque value, While the moving speed of the round die is reduced, when the detected torque value is lower than the set torque value, the moving speed of the round die is controlled to be increased.
[0009]
Further, the round die type rolling device according to claim 5 and claim 6 of the present invention sets a plurality of rotation angle acceleration / deceleration corresponding to the set torque value, and sets the rotation angle acceleration / deceleration or acceleration / deceleration. The rotational speed or the moving speed of the round die is controlled based on the following.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a round die type rolling device according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of a round die type rolling device according to the present invention. As shown in this figure, the round die rolling device 5 sandwiches the work 7 between a pair of round dies 6a and 6b, and moves the round dies 6a and 6b so as to approach while rotating. It is to be made. On the base 8, left and right symmetrical die moving bases 10a and 10b are mounted so as to be slidable in the left-right direction. Is done. Dice pushing mechanisms 11a and 11b are fixed to both sides of the die moving tables 10a and 10b on the base 8. The pushing mechanisms 11a and 11b move the round dies 6a and 6b toward the center of the axis of the work 7, and include a hydraulic cylinder, a pneumatic cylinder, a motor, a spline, and the like. The cylinder shafts 12a and 12b of the pushing mechanisms 11a and 11b and the die moving tables 10a and 10b are fixed. The spindles 9a and 9b are connected to drive sources 14a and 14b such as servo motors. Although not shown, two or more round dies 9a and 9b may be provided on each of the die moving tables 10a and 10b, and one round die 9a or 9b is fixed and the other round die 9b or 9a is fixed. Only the case may move. When the round dies 9a and 9b are pressed in the radial direction of the work 7 while rotating, and the rolling pressure is applied, the work 7 rolls and repeats local plastic deformation, thereby forming grooves in the work 7.
[0011]
Rotation angle detecting means 15a and 15b for detecting a rotation angle are mounted on the axes of the main shafts 9a and 9b, respectively. The signals from the rotation angle detecting means 15a and 15b are fed back to numerically control the rotation of the spindles 9a and 9b. Further, a distance detecting means 18 for detecting a distance between the moving tables is mounted between the moving tables 10a and 10b. The signal from the distance detecting means 18 is also fed back, and the distance between the moving tables, that is, the distance between the spindles is numerically controlled. Further, torque detecting means 16a, 16b are attached to each of the spindles 9a, 9b, and a load detecting means 17 for measuring a die load during rolling is attached to an end of the die moving base 10a. As the torque detecting means 16a and 16b, for example, a torque meter for directly measuring a torque value, a means for detecting a load of a servomotor by a current or a voltage, and calculating a torque value are used.
[0012]
FIG. 2 shows an example of a control system configuration according to the embodiment. The control system processes the program stored in the memory 46 and the measurement data from each of the detection means by the CPU 45, and then, through the communication control unit 48 connected to the same bus line 43, the servo motor 14 for rotating the spindle. And transmission to the actuators of the pushing mechanisms 11a and 11b. Each of these actuators has a driver circuit, and the plurality of drivers and the I / O port 47 are connected to a communication control unit 48. A plurality of drivers, an I / O port 47 and a communication control unit 48 are connected by a serial communication line 44.
[0013]
FIG. 3 shows a change in torque when the torque control method according to the present invention is performed. The horizontal axis shows the rolling time, and the vertical axis shows the torque value detected by the torque detecting means 16a, 16b. The dashed line in the figure indicates the set torque value. This set torque value is set in consideration of the detected values of the die load and the die torque generated when rolling is performed with the rotation speed and the moving speed of the spindles 9a and 9b kept constant.
[0014]
First, a method of controlling the processing torque within a certain range by controlling the rotation speed of the spindles 9a and 9b will be described. In general, when the number of revolutions of the spindles 9a and 9b is increased, the number of rolling of the workpiece 7 during rolling increases, and the amount of cut decreases to reduce the generated torque. On the other hand, when the number of rotations is reduced, the number of rolling of the work 7 is reduced, and the generated torque is increased. The present invention uses this relationship to perform control to keep the generated torque constant. Upper and lower limiters are set for the rotation speeds of the main shafts 9a and 9b, and the main shafts 9a and 9b are automatically changed within the range of the limiters. At the point (1) in the figure immediately after the start of rolling, the spindles 9a and 9b rotate at a preset initial rotation speed. The generated torque gradually increases, and the torque control is started at the point (2) in the figure when the torque approaches the set torque value. Here, first, the torque value detected by the torque detecting means 16a, 16b is compared with the set torque value and determined. If the detected torque value is lower than the set torque value, a negative rotation angle deceleration is given to the main shafts 9a and 9b, and control is performed so that the rotation speed is reduced and the torque value is increased. When the torque further increases and exceeds the set torque value ((3) in the figure), a positive rotation angular acceleration is applied to the spindles 9a and 9b to increase the rotation speed and control the torque value to decrease. In the case where the torque is further increased by such control ((4) in the figure), the upper limit rotation speed of the limiter is set. As the rolling approaches the end while controlling the torque in this way, the torque is reduced, so the torque control is ended ([5] in the figure). The rotation speed of the main shafts 9a and 9b is set to the lower limit rotation speed of the limiter. In addition, by setting a plurality of rotation angle acceleration / deceleration in steps so as to sequentially increase in correspondence with departure from the set torque value, when the detected torque departs from the set torque value, the detected torque is quickly approached to the set torque value. When the torque approaches the set torque value, the fluctuation range of the torque can be reduced.
[0015]
In this way, by controlling the processing torque during rolling to be close to the preset torque value, it is possible to prevent the maximum value of the temporary spindle torque from being generated at the peak time, and to reduce the life of the rolling die. It can be greatly extended compared to the ones. Also, by controlling the torque, it is possible to form a thin hollow member by rolling. The above-described method of controlling the torque of the spindles 9a and 9b can also be applied to a differential speed rolling machine in which the workpiece 7 is pushed by a feeder without moving the spindles of the round dies 6a and 6b.
[0016]
Next, a method of controlling the spindle moving speed to control the processing torque acting on the spindles 9a and 9b to approach the set torque value will be described. In this case, when the spindle moving speed is reduced, the number of rollings of the workpiece 7 during rolling increases, and the amount of cut decreases, so that the generated torque decreases. On the other hand, when the spindle moving speed is reduced, the number of rolling of the work decreases, and the generated torque increases. The present invention performs control to keep the generated torque constant using this relationship. Similarly to the spindle speed described above, the upper limit and the lower limit of the main shaft moving speed are defined, and the main shaft moving speed is automatically varied within the limiter range. As shown in FIG. 3, at the point (1) in the figure immediately after the start of rolling, the spindles 9a and 9b move at a constant initial speed set in advance. The generated torque gradually increases, and the torque control is started at the point (2) in the figure when the torque approaches the set torque value. Here, first, the detected torque value detected by the torque detecting means 16 is compared and determined with the set torque value. If the detected torque value is lower than the set torque value, acceleration is applied to the movement of the spindle to increase the moving speed and control is performed so that the torque value increases. On the other hand, when the machining torque further increases and exceeds the set torque value ((3) in the figure), control is performed such that the deceleration is given to the spindle movement to increase the movement speed, and the torque value is reduced. If the torque is further increased by this control ([4] in the figure), the lower limit of the moving speed of the limiter is set. As the rolling approaches the end while controlling the torque in this way, the torque is reduced, so the torque control is ended ([5] in the figure). Then, the lower limit value of the limiter is set as the spindle moving speed, and the spindles 9a and 9b move at a constant speed. Similarly to the case of the rotation angle acceleration / deceleration described above, the detection torque is set in a plurality of steps so that the acceleration / deceleration of the main shaft movement is sequentially increased in accordance with the deviation from the set torque value. Can be quickly brought close to the set torque value. It should be noted that torque control can be performed with both the spindle moving speed and the above-described spindle rotation speed.
[0017]
Next, another embodiment of the round die type rolling device utilizing the torque control of the spindles 9a and 9b will be described with reference to FIGS. Note that the same members as those of the round die-type rolling device shown in FIG. The round dies 6a and 6b in this embodiment slide toward each other by the die moving table moving mechanism. The die moving stage moving mechanism includes a first die moving stage 10a, a second die moving stage 10b, and a pressure plate 26 disposed outside the second die moving stage 10b, which are arranged in parallel on the base 8. Things. Each of the die moving tables 10a and 10b and the pressure plate 26 is attached to a pair of slide rails 28 fixed on the base 8 so as to be slidable in the left-right direction. Further, four beam shafts 29 having the same circular cross-section are bridged between the first die moving stage 10a and the pressure plate 26 at four corners of the inner surface facing each other, and both ends of the beam shaft 29 are the first shaft. It is fixed to the die moving table 10a and the pressure plate 26, respectively. Therefore, the first die moving base 10a and the pressure plate 26 slide integrally on the slide rail 28 without changing the relative position. The positions of the four beam shafts 29 are all equidistant from the rolling position of the work 7 by the round dies 6a and 6b, and are equally spaced in the circumferential direction. Further, the rigidity of each of the four beam shafts 29 is set to be equal.
[0018]
The second die moving base 10b is slidably mounted on the slide rail 28 between the first die moving base 10a and the pressure plate 26, and has a through hole through which the four beam shafts 29 are inserted. It is provided at the four corners of the side. The pushing mechanism 11 such as a hydraulic cylinder is fixed to the pressure plate 26. The pushing mechanism 11 includes a cylinder shaft 12 that expands and contracts in the same direction as the die moving table 10b, and the tip of the cylinder shaft 12 is fixed to the outer surface of the second die moving table 10b.
[0019]
As shown in FIG. 5, when the pushing mechanism 11 is operated to extend the cylinder shaft 12, the second die moving table 10b is pushed and moves toward the work 7 on the slide rail 28 in the direction (1) in the figure. Slide to. On the other hand, a rack and pinion is provided between the second die moving table 10b and the pressure plate 26, and the pressure plate 26 is positioned opposite to the moving direction of the second die moving table 10b in the figure (2). In the same direction as the second die moving table 10b. At this time, the first die moving table 10a connected to the pressure plate 26 by the four beam shafts 29 also moves by the same distance toward the workpiece 7 in the same direction as the pressure plate 26 in the direction (1) in the figure. . Therefore, the first die moving base 10a and the second die moving base 10b slide toward each other by the same distance toward the work 7 and approach each other. In this embodiment, the right and left die moving tables 10a and 10b are brought close to each other by one pushing mechanism 11 by using the die moving table moving mechanism having the above-described configuration, and the round dies 6a and 6b are moved from both sides. 7 can be rolled. Further, by providing the rack and pinion, the center line S of the work 7 can always be kept constant, and the supply and discharge of the work 7 can be easily automated.
[0020]
When a rolling pressure is applied to the work 7, the pair of round dies 6 a and 6 b receive a reaction force P from the work 7, and the reaction force P is borne by the four beam shafts 29 via the cylinder shaft 12. Since the four beam shafts 29 are equally arranged above and below the work 7 with equal rigidity, the reaction force P is equally divided and shared by the four beam shafts 29. As a result, the beam shaft 29 slightly extends in the axial direction. However, since all four beams are equally well-balanced, the die moving tables 10a and 10b open upward and the upper portions of the round dies 6a and 6b are partially expanded. The workpiece 7 can be subjected to high-precision rolling without escaping.
[0021]
The rotation angle detecting means 15a, 15b and the torque detecting means 16a, 16b, which are arranged on the axes of the spindles 9a, 9b, and the distance detecting means 18 attached between the first and second die moving tables 10a, 10b, Since it is the same as the above embodiment, detailed description is omitted.
[0022]
【The invention's effect】
As described above, according to the round-die rolling device according to the first aspect of the present invention, the processing torque at the time of rolling that acts on the round die is detected, and the detected torque is brought close to a predetermined set torque value. As described above, since at least one of the rotation speed and the moving speed of the round die is controlled, it is possible to prevent the die torque from temporarily increasing as in the related art, thereby extending the life of the rolling die and improving the efficiency of the rolling. Fabrication processing is obtained.
[0023]
Further, according to the round die rolling device according to claim 2 of the present invention, two or more beam shafts are provided between the pair of die moving tables around the rolling position of the work by the round die. Since the die moving base is guided by the beam shaft to approach the beam shaft, and the reaction force generated between the pair of round dies is caused to be applied to the beam shaft by the rolling pressure, so that the round die is opened at the time of rolling. The cutting amount of the round die into the work can be controlled with high precision. For this reason, in addition to being able to control the processing torque acting on the round die, the cutting depth can be controlled with high accuracy, and the rolling accuracy can be further increased.
[0024]
Further, according to the round die rolling device according to claim 3 of the present invention, the detected torque value detected by the torque detecting means is compared with the set torque value, and when the detected torque value is higher than the set torque value, If the detected torque value is lower than the set torque value while increasing the rotation speed of the round die, the detected torque is reduced to the set torque value by lowering the rotation speed of the round die. Can be kept constant, and the rolling time can be kept constant, which is suitable for mass production of workpieces.
[0025]
According to the round-die rolling device according to claim 4 of the present invention, the detected torque value detected by the torque detecting means is compared with the set torque value, and when the detected torque value is higher than the set torque value, If the detected torque value is lower than the set torque value while decreasing the moving speed of the round dies, the detected torque is close to the set torque value by increasing the moving speed of the round dies. Can be kept constant, and the ideal rolling time for each work can be known.
[0026]
Further, according to the round-die rolling device according to claims 5 and 6 of the present invention, a plurality of rotation angle acceleration / deceleration are set in accordance with the set torque value, and the rotation angle acceleration / deceleration or Since the rotation speed or the moving speed of the round die is controlled based on the acceleration / deceleration, even when the detected torque value is apart from the set torque value, the detected torque value can quickly approach the set torque value, thereby improving the reliability of the torque control. Can be.
[Brief description of the drawings]
FIG. 1 is a plan view showing one embodiment of a round-die rolling device according to the present invention.
FIG. 2 is a configuration diagram of a control system of the round die rolling device.
FIG. 3 is a graph showing a relationship between a rolling time and a generated torque.
FIG. 4 is a plan view showing another embodiment of the round-die rolling device according to the present invention.
FIG. 5 is a front view of the round die-type rolling device in FIG. 4 during rolling.
FIG. 6 is a conceptual diagram of a conventional round die rolling device.
[Explanation of symbols]
5 Round die type rolling device 6a, 6b Round die 7 Work 9a, 9b Main shaft 10a, 10b Die moving base 11 Pushing mechanism 16a, 16b Torque detecting means 29 Beam shaft

Claims (6)

In a round die type rolling device that rolls a work with a set of round dies,
Providing torque detecting means for detecting the processing torque acting on the round die, controlling at least one of the rotation speed of the round die or the moving speed of the round die so as to keep the processing torque acting on the round die during rolling within a certain range. A round die-type rolling device characterized by the following. A set of die slides that support a set of round dies, a beam shaft that is bridged between the pair of die slides around a rolling position of the work by the round dies, A pushing mechanism for bringing the set of die moving bases closer to each other, and guiding the die moving base to the beam shaft to approach the same, and a reaction force generated between the set of round dies by the rolling pressure is applied to the beam shaft. A round die type rolling device configured to bear a load,
Providing torque detecting means for detecting the processing torque acting on the round die, controlling at least one of the rotation speed of the round die or the moving speed of the round die so as to keep the processing torque acting on the round die during rolling within a certain range. A round die-type rolling device characterized by the following. The detected torque value detected by the torque detecting means is compared with a set torque value, and when the detected torque value is higher than the set torque value, the rotation speed of the round die is increased, while when the detected torque value is lower than the set torque value. 3. The round-die rolling device according to claim 1, wherein the rotation speed of the round die is controlled to decrease. The detected torque value detected by the torque detecting means is compared with a set torque value, and when the detected torque value is higher than the set torque value, the moving speed of the round die is decreased, while when the detected torque value is lower than the set torque value. 3. The rolling device according to claim 1, wherein the moving speed of the round die is controlled to increase. 4. A round die rolling according to claim 3, wherein a plurality of rotation angle acceleration / deceleration are set in accordance with the set torque value, and the number of rotations of the round die is controlled based on the rotation angle acceleration / deceleration. apparatus. The round die rolling device according to claim 4, wherein a plurality of acceleration / decelerations are set in accordance with the set torque value, and a moving speed of the round die is controlled based on the acceleration / deceleration.

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