JPS63260756A - Method for controlling driving motor of wire saw device - Google Patents

Abstract

PURPOSE:To promote the simplification of a wire driving system, by periodically inverting the rotary direction of a driving motor and setting the feed direction speed of a wire larger than its return direction speed so that the wire is moved by the amount of that difference. CONSTITUTION:A workpiece 13, fixed on a sawing bed 29, is lifted by a sawing feed mechanism 30, while abrasive grains are supplied to the workpiece 13 coming into contact with a wire 2, and a driving motor 9, if it is driven while periodically inverting its direction of rotation, transmits the rotation to sawing head rollers 10-12 and tension rollers 7, 8, moving the wire 2 in normal and reverse directions to cut the workpiece 13. The driving motor 9, is set during its one cycle with feed direction speed of the wire larger than its return direction speed, successively moves the wire 2 in its feed direction by the amount of that speed difference. In this way, a wire driving system can be simplified reducing a mechanical vibration, and improving sawing accuracy by that amount.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a wire saw device, and more particularly to a method of controlling a wire drive motor.

Prior Art This type of wire saw device is known, for example, from Japanese Patent Publication No. 56-198.
No. 56-199 or JP-A No. 60-532
As seen in No. 73, the wire is fed out from the supply spool and is given reciprocating linear motion in the running direction. This linear reciprocating motion is mainly provided by a seesaw mechanism, a planetary gear mechanism, or a crank mechanism. In other words, these mechanisms apply reciprocating motion to the running wire in the running direction by repeating reciprocating rocking motion during the cutting operation, thereby suppressing the amount of wire fed for one unit of cutting. There is.

However, if such a mechanism is used, the winding of the wire becomes complicated, and the swinging mechanism becomes complicated, resulting in an increase in the size of the wire saw device.

Under these circumstances, an appropriate reciprocating means is desired in place of the above-mentioned mechanism.

OBJECT OF THE INVENTION Accordingly, an object of the present invention is to allow a wire to travel back and forth and to pay out the wire little by little in the feeding direction without using a conventional seesaw mechanism or the like.

Solution to the Invention In view of the above object, the present invention, when driving a wire-driving roller by a drive motor, periodically reverses the rotational direction of the drive motor and changes the wire feeding direction during one cycle. The number of rotations is set higher than the number of rotations in the return direction, so that the wire is sequentially moved in the feeding direction while reciprocating.

In this way, the reciprocating movement of the wire can be performed in the field of electrical control by controlling the rotational direction and rotation speed of the drive motor, so the driving means for reciprocating movement and its control are compared to conventional mechanisms. It can be simplified. Furthermore, since changes in the number of rotations and differences in rotational direction can be easily changed in the electrical field, it is possible to set the most appropriate cutting conditions for various processing materials.

Structure of the Invention First, FIG. 1 shows the winding state of the wire 2 of the wire saw device 1 and its drive system.

The wire 2 is wound in an aligned manner around a pair of left and right glue rules 3.4, between which a pair of left and right weighted dancer rollers 5.6, a tension roller 7.8, and a triangular apex position seen from the front are arranged. It is wrapped multiple times around three processing rollers 10, 11, and 12 with guide grooves.
There is. At an intermediate position between the two processing rollers 11 and 12, the wire 2 is in contact with the workpiece 13 on the processing table 29 having the processing feed mechanism 30 in the upward direction with a predetermined force via the abrasive grains, Due to the relative movement of the two, a predetermined kerf is formed there. And, on the other hand, Noriru 3 is
The wire 2 is driven by the torque motor 14 while being slightly resisted in the sending direction, and the other reel 4
is driven by the torque motor 15 in the direction in which the wire 2 is wound. In addition, in these rolls 3.4,
A traverse mechanism (not shown) is provided, and by its action, the wire 2 is wound around the outer periphery of the reel 3.4 or rewound in an aligned manner.

On the other hand, the pair of tension rollers 7.8 are driven by the drive motor 9.
The relationship is driven by. That is, the rotation of the drive motor 9 is transmitted through the intermediate shaft 1 as one rotation transmission path.
6. Transmitted to the input shaft 19 of the first differential gear mechanism 21 via a pair of gears 17 and 18, further transmitted to one tension roller through its output shaft 20, and as a rotation transmission path for the other , and is branched by a timing belt/pulley 23 in the middle, and is transmitted to the other tension roller 8 via an intermediate shaft 24 . Furthermore, the rotation of the intermediate shaft 16 is transmitted to each machining process via the timing belt pulley 25, the input shaft 26 of the second differential gear mechanism 22, its output shaft 27, and the timing belt pulley 28.
11.12 is transmitted to the drive shaft. Note that the first differential gear mechanism 21 and the second differential gear mechanism 22 are both equipped with control shafts 31 and 32 as third shafts, and tension control motors 33 that are reversibly rotatable at these portions, respectively. , coupled to the phase control motor 34.

Next, FIG. 2 shows an example in which the first differential gear mechanism 21 is constituted by a bevel gear train. The rotation of the human power shaft 19 is caused by a bevel gear 35, two middle bevel gears 36, and an output shaft 20.
The rotation is transmitted in the opposite direction by the bevel gear 37. The intermediate bevel gear 36 is connected to the shaft 3 which is perpendicular to the input shaft 19 and the output shaft 20.
8, it is rotatably supported by a large bevel gear 39. This large bevel gear 39 is connected to the output shaft 2.
0, and meshes with the bevel gear 40 on the control shaft 31 side.

Note that the second differential gear mechanism 22 is also configured in exactly the same manner as the first differential gear mechanism 21, as shown in FIG. Therefore, in FIG. 3, the specific structure is indicated by the same reference numerals as in FIG. 2.

Furthermore, FIG. 4 shows the configuration of the control device 41.

This control device 41 is connected to an operation panel 43 on the input side of a main controller 42, and is connected to a control unit 44, 45, 46 and a tension control unit 4 on an output side.
7 and a phase control unit 48. These control units 44, 45, 46 respectively include a drive motor 9, a torque motor 14 and a driver 49, 50 of the machine 5.
．． 51. In addition, the tension control unit 47
and the phase control unit 48 are both connected to two tension sensors 52, 53 on the input side, and are connected to the drivers 54, 55 of the tension control motor 33 and the phase control motor 34, respectively, on the output side.

Effect of the Invention A cylindrical workpiece 13 such as a semiconductor, for example, is fixed on a processing table 29 with the cutting direction and the direction of the wire 2 aligned, and is raised by the upward feeding action of the processing feed mechanism 30 to be cut. It touches wire 2 at the starting position. At the same time,
Abrasive grains are supplied to the contact area.

When the drive motor 9 is started in this state, its rotation is as follows.
It is transmitted via the intermediate shaft 16, the timing belt pulley 25, the second differential gear mechanism 22 and the timing belt pulley 28 to the three processing rollers 10.11.12. Further, the rotation of the intermediate shaft 16 is transmitted through the gear 17.18, the first differential gear mechanism 21, to one tension roller, and further through the timing belt boot +723.
The other tension roller 8 also has a processing roller 10.
．． It is transmitted as a rotation in the same direction as 11.12.

As shown in FIG. 5, the driving motor 9 rotates in the forward direction at a certain time t1, then reverses at the following time t2, and rotates in the reverse direction, completing the cycle. , we will manipulate this back. The acceleration time and deceleration time in each of these rotational directions are set to be the same.

However, the time of constant speed is long at time t1,
Further, the time period t2 after that is set short.

As a result, as shown in Fig. 6, the wire 2 periodically repeats a high number of rotations in the forward rotation direction followed by a small number of rotations in the reverse direction, and each cycle corresponds to the rotation difference (time difference). The material is sequentially supplied in the sending direction with a feeding amount of In this way, the wire 2 reciprocates in the linear direction, and in the course of the reciprocating movement, a plurality of parallel cuts are formed in the workpiece 13. In the process of this cutting progress, the processing table 29 is raised little by little by the processing feed mechanism 30, and the workpiece 1 is
3 is pressed with a predetermined force.

During this time, the torque motor 14 rotates the reel 3 in the feeding direction, thereby feeding out the wire 2 in the feeding direction. On the other hand, the torque motor 15 sequentially winds up the wire 2 after the cutting operation by rotating the reel 4 with a predetermined torque. These torque motors 14.15 are started and stopped in synchronization with the operation of the drive motor 9, respectively, by voltage control from a control unit 44.45. However, since the wire 2 is fed intermittently while repeating reciprocating motion, a slight difference occurs between the amount of movement of the wire 2 at the cutting position and the amount of movement of the wire 2 on the feeding side or winding side. It is therefore absorbed by the up and down movement of the dancer rollers 5.6. In addition, the play in the wire 2 and fluctuations in the winding force due to the difference in response between the drive motor 9 and the torque motor 14.15 are
It can also be absorbed by the slip of the torque motor 14,15.

During such cutting, the contact force of the wire 2 against the workpiece 13 must always be constant in view of the quality of the cut surface. This requires setting and maintaining an appropriate tension in the wire 2, which is accomplished by the tension control unit 4.
This is made possible by 7.

That is, this tension control unit 47 receives a signal from the tension sensor 52 or 53 as an input, and rotates the tension control motor 33 in a predetermined direction by the necessary amount according to the deviation between the signal and the target value. , giving a phase difference, that is, a difference in rotation speed, between the pair of tension rollers 7.8.

Specifically, in the process in which the rotation of the drive motor 9 is transmitted to one tension roller rough, the input shaft 19 and the output shaft 20 of the first differential gear mechanism 21 may have the same rotation speed in different directions. For example, the pair of tension rollers 7.8 always rotate with no difference in rotational speed. This kind of condition is
It can be set by stopping the tension control motor 33. Now, assuming that the control shaft 31 is stopped, the large bevel gear 39 is also stopped, so the bevel gear 35 on the input side
The rotation is converted in the opposite direction by the intermediate bevel gear 36 and transmitted to the output side bevel gear 37 at a transmission ratio of 1.

However, the tension control motor 33 rotates in a predetermined direction,
When the large bevel gear 39 is rotated, for example, in the opposite direction to the output shaft 20 and stopped in that state, the output shaft 20 rotates in the opposite direction to the input shaft 1.
As shown in FIG. 7, the rotation continues with a delay of the phase angle θ. Therefore, the tension roller 7 on the sending side continues to rotate with a delay of the phase angle θ with respect to the tension roller 8 on the winding side. As a result, the wire 2 is stretched between the pair of tension rollers 7.8 with a high tension corresponding to the phase angle θ. Moreover, by performing the opposite operation, that is, by rotating the large bevel gear 39 in the same direction as the output shaft 20, the tension can be lowered. In this way, the wire 2 cuts into the workpiece 13 with a constant tension, regardless of changes in the cut edge of the workpiece 13 as the cutting progresses.

The tension control motor 33 is a pulse motor, and therefore the tension control unit 47 gives the tension control motor 33 rotation in the necessary correction direction as a pulse number, which corresponds to the pulse number.

The tension control motor 33 is rotated as much as possible, and then automatically stopped in that state. In this way, the tension side<B unit 47 automatically adjusts the tension of the wire 2 to the target value by inputting the signals from the tension sensors 52 and 53 and controlling the rotation direction and rotation amount of the tension control motor 33. We will make corrections accordingly.

In this tension control process, the pair of tension rollers 7
．． 8 and the three machining hend rollers 1O111 and 12, and as this accumulates, the difference in the detection amounts of the left and right tension sensors 52 and 53 gradually increases, and this is due to a part of the wire 2. creating abnormal tension on the wire, leading to the risk of wire breakage. In such a state, tension sensors 52 and 53 are activated as well as tension control.
It can be detected by the signal difference between Therefore, when such misalignment occurs, the phase control unit 48 rotates the phase control motor 34 in one of the correction directions, and the second differential gear mechanism 22 causes the pair of tension rollers 7.
8 and the three processing hend rollers 10 and 1112, and keep the tension of the wire 2 near the left and right tension sensors 52 and 53 at almost the same value, while the wire 2 is running in the forward and reverse directions. Even if there is a change in the tension of the wire 2 due to some reason, it is maintained in a state where it can be sufficiently absorbed. Here, similarly to the tension control motor 33, the phase control unit 48 controls the amount of rotation of the phase control motor 34 by controlling the number of pulses.

When the drive motor 9 shifts from normal rotation to reverse rotation, a predetermined reverse rotation torque is applied, the speed decreases, the rotation changes to reverse rotation after passing a stop point, and when the predetermined speed is reached, this torque disappears. In this case, on the unwinding and winding sides, a reversing torque is simultaneously applied to the torque motor 14.15, and each reel 3.4 undergoes a process of deceleration, stop, and reversal, and performs a reversal operation. The magnitude of the reversal torque in this case is not constant depending on the amount of wire 2 remaining on the reel 3.4,
It is related to the number of times the wire 2 repeats forward and reverse rotations after the start of processing. The main controller 42 calculates this number of times and the wire feed amount, and transmits the necessary commands to the control units 45 and 46. Therefore, the control units 45, 46 receive this instruction and the signal when the drive motor 9 starts the reverse operation, and instruct the driver 50, 51 to generate the required torque. In response to this, the feeding and winding sides are controlled with appropriate reverse torque, and although theoretically there should be no slack or excessive tension in the wire 2, the slight speed that occurs on the cutting mechanism side Fluctuations and unwinding Any fluctuations in the winding section itself will cause slight slack or tension in the wire 2, and this inconvenience is absorbed by the dancer rollers 5.6. That is, the dancer rollers 5.6 are lowered when slack occurs, and raised when tension occurs. and,
Although not shown, a potentiometer paired with each dancer roller 5.6 detects the position of each dancer roller 5.6 and provides feedback to each control unit, so each control unit can In response to this, the torque applied to each torque motor 14.15 is finely adjusted to return the dancer roller 5.6 to its original position. This mm adjustment operates not only when the drive motor 9 is reversed but also during steady rotation. In this manner, on the feeding and winding side, the action of the dancer roller 5.6 and the feedback control constantly stabilizes the feeding and winding of the wire 2 and stabilizes the tension of the wire 2.

Modifications of the Invention In the above embodiment, a common drive motor 9 drives the pair of tension rollers 7.8 and the three processing head rollers 10, 11.12. Therefore, the second differential gear mechanism 22 is interposed between the drive motor 9 and the drive shaft 30. However, if the drive source of the roller l0111.12 for these processes is different from the drive motor 9, such a second differential gear mechanism 22
This can be omitted.

Further, in the above embodiment, the first differential gear mechanism 21 is configured by a bevel gear train, but such a differential gear mechanism may also be configured by a planetary gear train or the like.

Effect of the invention The present invention has the following unique effects.

Since the reciprocating movement of the cutting wire in the feeding direction is performed by controlling the rotation direction and rotation amount of the drive motor,
A complicated seesaw mechanism like the conventional one is not required, and the wire drive system can be simplified.

Additionally, since there is no reciprocating drive mechanism such as a rank and pinion or crank mechanism, machine vibrations are reduced and machining accuracy is improved accordingly.

Furthermore, pattern control such as wire processing speed, processing feed, and wire tension throughout the cutting process can be easily set or changed in the electrical field, making it possible to cut under the processing conditions most suitable for the material of the workpiece. Accidents such as wire breakage during cutting are also prevented, which can be expected to improve processing efficiency.

[Brief explanation of the drawing]

Fig. 1 is a schematic perspective view of the wire winding state and drive system of the wire saw device according to the present invention, Figs. 2 and 3 are skeleton diagrams of the differential gear mechanism, and Fig. 4 is a block diagram of the control device. FIG. 5 is a pattern diagram of the rotation control of the drive motor, FIG. 6 is an explanatory diagram of the movement status of the wire, and FIG. 7 is an explanatory diagram of the phase difference between a pair of tension rollers. 1. Wire saw device, 2. Wire, 3.4. Reel, 5.6. Dancer roller, 7.8. Tension roller, 9. Drive motor, 1O111, 12. Processing head roller, 13... Workpiece, 21... First differential gear mechanism, 22... Second differential gear mechanism, 29... Processing table, 33... Tension control motor, 34... Phase control motor.
41...control device, 47...tension control unit, 48...
・Phase control unit, 52.53...Tension sensor. Patent Applicant: Nichitoyama Co., Ltd. Attorney: Kunio Nakagawa Figure 5

Claims (1)

[Claims] In a wire saw device that cuts a workpiece by moving the cutting wire back and forth in a straight line while pressing it against the workpiece, a wire-driving roller is rotated by a drive motor, and the direction of rotation of the drive motor is periodically changed. A method for controlling a drive motor for a wire saw device, characterized in that the wire is reversed, the number of rotations in the feeding direction of the wire is made larger than the number of rotations in the return direction, and the wire is moved in the feeding direction by the difference in the number of rotations.