JPH03196962A - Wire saw - Google Patents

Abstract

PURPOSE:To make any force, inclining to up or down, so as not to be added to a wire, and prevent fluctuations in working pressure of the wire from occurring as well as to keep off any vertical variation in a running position of the wire by installing a means holding the wire's running position at a constant position. CONSTITUTION:A weight sum of a work table 54 at the upper part and a workpiece 41' is set to W1 and weight of a weight 62 corresponding to the former to W'1, respectively, as well as a weight sum of a work table 50 in the lower part and a workpiece 41 is set to W2, and weight of a weight 63 corresponding to the former to W'2, respectively, and when pressing force of one side of these workpieces to a wire 46 is set to F, it is set to an equation of W1+W2=W'1+W'2, W1-W2=F, namely, both these work tables 50, 54 unified in one by this pressing force are balanced with the weight sum of both weights 51, 55 as a whole, whereby they come to a state of being floated in the vertical direction. Consequently, during a working process, the wire 46 is prevented from moving in the vertical direction and a running position of the wire 46 is always holdable in a constant position.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a wire saw for machining workpieces made of highly hard materials such as ferrite and ceramics, and particularly to a wire saw suitable for machining with high precision. .

[Conventional technology]

For example, for a VTR magnetic head, etc., as shown in FIG. 5, a long bar-shaped magnetic head material 4101 formed in one body is made into one piece by cutting the part shown by the dotted line, and cutting it into one piece as shown in FIG. 6. One magnetic hood 42 is molded by separating it into one piece.

Since the magnetic helad 42 formed in this way reads and writes information from the tape in the gap 43 at its tip, the height position H from the bottom surface 44 will be determined in the subsequent assembly process.
is very important, and its accuracy is required to be on the order of microns.

Therefore, conventionally, for example, as shown in FIG. 7, one drive roller 48 and two guide rollers 45 and 45', each having grooves 47 formed at equal intervals on its outer peripheral surface, and two guide rollers 45 and 45' were configured to be freely rotatable in a triangular shape. Place the above three rollers 48.45.4
The wires 46 stretched at equal intervals in each groove 47 of 5' are sequentially fed out by the rotational drive of the drive roller 48, and the workpiece (magnetic head material) 41 is attached to the plurality of wires 46 stretched in the horizontal direction. A method has been implemented in which the workpiece 4I is cut by pressing and supplying abrasive grains.

However, in the above method, the relationship between the load applied to each wire 46 and the displacement of the wire 46 is determined by the deviation of the cross-sectional shape of the wire 46 from a perfect circle or the abrasive grain distribution between the wire 46 and the workpiece 41. Due to non-uniformity, the cutting direction and the load direction do not necessarily match, resulting in a problem of poor cutting accuracy and cutting efficiency.

Therefore, as described in, for example, Japanese Unexamined Patent Publication No. 54-163491, the main part of which is shown in FIG. 8, workpieces 41.degree. Then, the workpiece 41 that is pressed against the wire 46 from below to above is attached to the table 50, the table 50 is connected to the weight 5I, and the sum of the weights of the workpiece 41 and the table 50 is calculated from the weight W2 of the weight 51. A system has been implemented in which the force obtained by subtracting W is used as the lifting force for the table 50, and a screw 53 rotated at a constant rate by a motor 52 acts as a stopper.

[Problem to be solved by the invention]

When a plurality of workpieces 41 are provided in the upper and lower directions as in the prior art shown in FIG. A slight variation occurs, and this may cause a difference in the speed at which the wire 46 processes the upper and lower surfaces.

For example, assuming that the top surface is processed at a faster speed than the bottom surface, the wire 46 will move toward the top surface, which is processed at a faster speed, as shown in Figure 1O. This condition frequently occurs during processing, and it becomes impossible to hold it in a fixed position. When the wire 46 is in this state, the tension changes and the wire 4
The machining force exerted by 6 on the workpiece 41 becomes large, and the machining conditions at the time of cutting become unstable. This causes waviness to occur on the cut surface.

Moreover, the distance between the wires 46 should be precisely maintained by the grooves 47 of the guide rollers 45 and 45', but when the running position of the wire 46 reaches above the predetermined position as shown in FIG. Since the distance between the wires 46 and 46 is largely restricted by the workpiece 41 above which is processed at a high speed, the distance between the wires 46 fluctuates, causing waviness on the cut surface.

Furthermore, in the prior art shown in FIG. 9, although the amount of rise of the table 50 is controlled by a weight 51, the amount of rise of the table 50 is actually controlled by a screw driven by a motor 52, and is in a floating state. Therefore, if the machining speed of the workpiece 41 changes, the wire 46
The traveling position of the vehicle changed, causing a problem similar to that of the embodiment shown in FIG.

SUMMARY OF THE INVENTION An object of the present invention is to provide a wire saw that eliminates fluctuations in the wire running position that occur during the machining process and prevents waviness of the cut surface.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a wire saw that presses a workpiece against a wire from both sides in a direction perpendicular to the wire running direction and cuts it with abrasive grains, in which the running position of the wire is always maintained at a constant position. A wire holding means is provided.

Further, the wire holding means is constituted by a floating mechanism that floats a work table on which each workpiece is placed in a direction perpendicular to the running direction of the wire.

In addition, in order to balance the sum of the weights of both weights using both tables that are integrated by force, the floating mechanism is designed to balance the weight of the upper work table and the workpiece placed on the upper work table. The sum is W1, the sum of the weights of the lower work table and the workpiece placed on the lower work table is W2, and the weight of the weight corresponding to the upper work table is Wl', the weight corresponding to the lower work table. The wire is constructed so that w, +w, = w, ' + w2 W, -W, = F, where the weight of WZ' is WZ' and the force of the workpiece above pressing against the wire is F. be.

In addition, in order to prevent biased force from being applied to the wire either up or down, the wire holding means is connected simultaneously to a cylinder that moves the work table in a direction perpendicular to the running direction of the wire, and the suction ports of both cylinders. It consists of a common injection port.

Further, in order to keep the running position of the wire constant, the wire holding means includes a workpiece feeding means for feeding the workpiece in a direction perpendicular to the running direction of the wire as processing progresses, and It is composed of a detection means for detecting the position, and a control means for controlling the feeding of the workpiece feeding means based on the detection result of the detection means.

[Effect]

As described above, when the wire moves in the vertical direction during the processing process, the present invention detects this and adjusts the wire to a predetermined position, so that the running position of the wire can always be maintained at a constant position.

Further, in the present invention, the sum of the weights of the upper work table and the workpiece is Wll, the weight of the corresponding weight is Wl', and the sum of the weights of the lower work table and the workpiece is WI,
When the weight of the corresponding weight is W2' and the force with which one workpiece presses against the wire is F, set w, +w, = w, ' +w2 WI Wz=F, that is, the pressing is Both worktables, which are united by the force F, are balanced with the sum of the weights of both weights and are in a vertically floating state, which prevents the wire from moving vertically during the processing process. The running position of the wire can always be maintained at a constant position.

Therefore, there is no change in parameters during the cutting process, and the wire is always positioned on the tangent line of the guide roller, so the spacing is regulated by the grooves formed on the guide roller, which allows precise machining without waviness. I can do it.

〔Example〕

Hereinafter, FIG. 1 showing an embodiment of the present invention will be described.

As shown in FIG. 1, a table 50 is mounted with workpieces 41 and 41' that alternately press the wire 46 from opposite directions by shifting their positions with respect to the running direction of the wire 46.
．． 54 and a weight 51.54 connected to the table 50.54 via a rope. Further, the sum of the weights of the upper table 54 and the workpiece 41' is W, and the weight of the weight 55 is W, the sum of the weights W1 of the lower table 50 and the workpiece 41, and the weight of the weight 50 are W.
2, W 1 + W 3 = W z + W 4, and the maximum force F of the pressing force from the wire 46 acting on the upper workpiece 41' is F=W3-W.

It is said that Therefore, the upper workpiece 41' tries to move downward by the force F, but the amount of movement of the upper table 54 is regulated by the screw 57 which is rotated at a constant rate by the motor 56. Therefore, the running position of the wire 46 may shift as shown in FIG. 10 during the processing process. Therefore, the present invention provides a position sensor 72 that detects when the running position of the wire 46 deviates, and drive control means 74, 74 based on the detection result of the position sensor 72.
Control means 73 are provided for controlling the rotation of the motor 56.52 via '.

Therefore, according to this embodiment, when the wire 46 moves in the vertical direction during the machining process, the position sensor 72 detects this, and the control means 73 controls the motor 52.56 via the drive control means 74.74'. Rotate the upper table 54,
Since the position of the lower table 50 is adjusted, the running position of the wire 46 can be always maintained at a constant position.

Next, FIG. 2 showing another embodiment of the present invention will be described.

In the embodiment shown in FIG.
．． Upper table 54 and lower table 5 with 41' attached
08. A weight 62.63 is provided which is connected to the table 50.54 via a rope. The weight 62.6
The relationship between the weights w, ', w2' of 3, the sum W1 of the weights of the upper table 54 and the workpiece 41, and the sum W2 of the weights of the lower table 50 and the workpiece 41 is W, as in the case of FIG. +Wz=Wl' +Wt W, -W, =F is made to be satisfied. Therefore, the upper table 5
0 moves downward, but the upper table 54 and the lower table 50 each have a cylinder 6 fixed at a fixed position.
The liquid inlet 6 of the cylinder 65.67 is fixed to the tips of the pistons 66, 68 sliding inside the cylinder
9.70 is connected to the liquid supply a (not shown) via the common injection lower 1, so that the upper table 54 and the lower table 50 are in a floating state.

Next, FIGS. 3 and 4 showing still another embodiment of the present invention will be described.

As shown in FIG. 3, the wire 2 is connected to a certain number of guide plates 5 between a guide roller 3, only a portion of which is shown in the figure, and a drive roller 4 installed above the guide roller 3.
, 6, and the drive roller 4 is rotatably supported by a bearing 7 fixed to the guide plate 6, and is driven by a shaft 8 connected to a power transmission mechanism (not shown) at its tip. Therefore, the wire 2 runs in the front and rear directions in the figure while pressing the workpieces 1 and 1', and supplies abrasive grains to the workpiece 1.1.
′ is cut. The workpiece 1゜1' is placed on a sample stage 1 facing vertically so that the wire 2 is inserted therein.
0.10', and the sample stage 10.10' is fixed to a fixed stage 11.11'. The fixed stages 11 and 11' are an upper stage 12 and a lower stage 1, respectively.
3, and the upper stage 12 and lower stage 13 are respectively fitted into the guide surfaces on both sides of the guide post 14 so as to be slidable in the vertical direction.

The guide boss 4 is connected to the column 3 fixed on the base 30.
1 includes an upper guide joint 16 and a lower joint 15.
A through hole 14a is formed approximately in the center of the lever 14a, which is large enough to allow a lever 20 (described later) to swing in the vertical direction. Further, the upper stage 12 and the lower stage 13 are connected to weights (not shown) through ropes 17 and 18 at their rear ends, and as will be described later, the weights of the weights apply force in a direction toward each other so that the upper stage 12 and the lower stage 13 maintain a floating state. In addition, the lower end of the receiver 22 fixed to the opposite side of the lower stage 13 of the upper stage 12 is swingably supported at one end by the lower stage 13 via a pin 19 by a weight as shown by the dashed line. Protrusion 2 of lever 20
1, and thereby the upper stage 12
is integrated with the lower stage 13, and the whole is balanced and in a floating state. Lever 2 above
0 rotatably supports a roller 23 at the other end, and the roller 23 is inserted into a recess of a slider 24.

The slider 24 is threadedly supported by a screw shaft 25, and the screw shaft 25 is connected to a motor 26. The motor 26 is fixed to a bracket 26a which is fixed to the rear end of the lower stage 13 and connected to a weight via a rope 18. Therefore, when the motor 26 is driven and the screw shaft 25 rotates, the other end of the lever 20 moves vertically via the slider 24 around the pin 19 at one end.
The upper stage 12 moves in the vertical direction via the protrusion 21 and the receiver 22 to adjust the distance between the two workpieces 1 and 1' and the position relative to the wire 2. .1' machining feed can be performed. Furthermore, when the tip of the lever 20 is moved in the vertical direction by the motor 26, the protrusion 21, which is at a position that is reduced in length with respect to the length up to the tip, moves the receiver 22 in the vertical direction. The amount of vertical movement of the receiver 22 is smaller than the amount of vertical movement of the tip of the lever 20 caused by the motor 26, which causes speed fluctuations caused by the motor 26 and the screw shaft 2.
Smooth reception by reducing fluctuations caused by machining errors in step 5.2
2 can be moved, the processing accuracy of the workpiece 1.1' can be improved.

Next, the total weights W, , W2 of the upper stage 12 and lower stage 13 and the weights w,', w2 of the weights are set so as to satisfy the following conditions.

J+W2=Wl'+W2' ・・・・・・・・・
(1) W2-w, =w, -w, =f...
(2) However, f is the maximum value of the force that the workpieces 1, 1' press against the wire 2. Therefore, the upper stage 12
is heavier than the weight, so it moves downward, and the lower stage 13 has less weight than the weight, so it moves upward, so that the lower end of the receiver 22 is always in contact with the protrusion 21 of the lever 20.

Next, the actual method of use will be explained with reference to FIG.

Basically, the upper stage 12 and the lower stage 13 are floated as shown in Fig. 3, and the workpiece 1 during machining is
, 1' are sent by the motor 26. However, in actual use, it is necessary to carry out the following steps, including setup.

An arm 373 is attached to the upper stage 12 and the lower stage 13.
7' is installed. The arm 37.37' is provided with a slider 32.32' in its longitudinally intermediate position. The sliders 32, 32' are supported by brackets 32a, 32a' fixed to the column 31, respectively, and have threaded shafts 34, 34' rotated by motors 33, 33'.
The arms 37 and 37' are moved vertically by the motors 33 and 33'. Also, screws 35 and 35' are attached to the tips of the arms 37 and 37', respectively.
and a length measuring machine 36, 36'. The screw 3
5.35' is manually rotated to come into contact with the upper and lower surfaces of the block 38 fixed to the column 31, and when the arm 5.35' is rotated manually, the upper stage 12 and the lower stage 13 are moved in the vertical direction via the arm 37.37'. Moving. The above length measuring machine 36
．． When the tip of the arm 36' is brought into contact with the upper and lower surfaces of the block 38, the arm 36' is connected to the upper stage 12 via the arm 37 and 37'.
and the position of the lower stage 13 are displayed on a display device (not shown) to notify the operator.

Next, the processing procedure will be explained.

First, the motor 33 is driven to move the slider 32 downward, and the motor 33' is driven to move the slider 32' upward.
2 and the lower stage 13 are separated from the wire (not shown), and the workpiece (not shown) to be processed is moved to the upper stage 1.
2 and the lower stage 13.

Thereafter, the motors 33, 33' are driven in the opposite direction to move the upper stage 12 and lower stage 13 toward each other via the slider 32, 32' and the arm 37, 37, thereby moving the workpiece 1. .1' to the machining start position.

Next, the motor 26 is driven to bring the lower end of the receiver 22 into contact with the protrusion 21. At this time, the positions of the upper stage 12 and the lower stage 13 are detected by the length measuring devices 36 and 36'. After detection, the motors 33, 33' are driven to move the slider 32, 32' away from the arm 37, 37' so that it does not come into contact with the arm 37, 37' during processing.

Further, the feed amount of the upper stage 12 and the lower stage 13 is set in advance, and the downward movement amount of the slider 24 corresponding to the predetermined feed amount of the upper stage 12 and the lower stage 13 is set in advance.

After that, when the motor 26 is driven and the slider 24 is moved downward by a preset amount, the lever 20
The upper stage 12 and lower stage 13 move toward each other via the receiver 22 to process the workpiece.

Then, when the machining is completed, the sliders 32 and 32 move again in the direction of separating them from each other, so that the workpieces are removed from the upper stage 12 and lower stage 13. At this time, it is desirable that the sliders 32, 32' contact the arms 37, 37 at the same time, but unless special precautions are taken, one of the sliders 32, 32' will contact the arms 37, 37' first. However, if this is done, one of the stages 12 and 13 will begin to move first, and the wire 2 will come into strong contact with the workpiece 1' or 1' attached to the other stage 13. To avoid this, the screws 35, 35' must be manually tightened when separating the upper stage 12 and lower stage 13 from the workpiece 1.1'. The upper stage 12 and the lower stage 13 are moved until the wire 2 is separated from the machined groove of the workpieces 1, 1', and then the motors 33, 33' are driven to move the wire 2 away from the machined grooves of the workpieces 1, 1'.

Upper stage I2 and lower stage 13 are moved to the removable position of 1'.

Therefore, it is possible to prevent the wire 2 from undulating and perform precise processing.

〔Effect of the invention〕

According to the present invention, in a wire saw that simultaneously processes a plurality of workpieces from the vertical direction perpendicular to the running direction of the wire, no upward or downward biased force is applied to the wire. Prevents fluctuations in machining pressure,
It is possible to prevent vertical fluctuations in the running position of the wire. Moreover, the pitch of the wire is also regulated by the guide roller, so that an accurate state can be maintained. Therefore, precise machining without waviness can be performed.

[Brief explanation of drawings]

Fig. 1 is a schematic front view of a wire saw showing one embodiment of the present invention, Fig. 2 is a schematic front view of a wire saw showing another embodiment of the invention, and Fig. 3 is a schematic front view of a wire saw showing another embodiment of the invention. A longitudinal cross-sectional view of a wire saw showing an example, FIG. 4 is a side view, FIG. 5 is a perspective view showing the target workpiece, FIG. 6 is a perspective view showing the state of the workpiece when completed, and FIG. 7 is a conventional 8 is a schematic front view showing an example of a conventional wire saw, FIG. 9 is a schematic front view showing another example of a conventional wire saw, and FIG. 10 is a schematic front view showing the wire running of a conventional wire saw. It is an explanatory view showing a movement state of a position. 1.1'... Workpiece, 3... Guide roller, 10
゜10'...Sample stage, 11.11'...Fixed stage, 12...Upper stage, 13...Lower stage, 1
4...Guide post, 19...Bin, 20...Lever, 21...Protrusion, 22...Receiver, 23...
Roller, 24...Slider, 32.32'...Slider, 33.33'...Motor, 34.34'...
Screw shaft, 35.35'...screw, 36.36'...
Length measuring machine, 37.37'...arm, 38...flock.

Claims (1)

[Claims] 1. In a wire saw that presses a workpiece against a wire from both sides in a direction perpendicular to the wire running direction and supplies abrasive grains to the processed part to cut the workpiece, the wire running position is always kept at a constant position. A wire saw equipped with a wire holding means for holding the wire. 2. The wire saw according to claim 1, wherein the wire holding means is constituted by a floating mechanism that floats a work table on which each workpiece is placed in a direction perpendicular to the running direction of the wire. 3. The floating mechanism calculates the sum of the weights of the upper work table and the workpiece placed on the work table by W.
_1. The sum of the weights of the lower work table and the workpiece placed on the lower work table is W_2, and the weight of the weight corresponding to the upper work table is W_1' The weight of the weight corresponding to the lower work table. W_2'
and the force that the upper workpiece presses against the wire is F
The wire saw according to claim 2, wherein the wire saw is configured to satisfy W_1+W_2=W_1'+W_2' W_1-W_2=F. 4. The wire holding means includes a cylinder for moving the work table in a direction perpendicular to the running direction of the wire, and a common injection port connected at the same time to the suction ports of both cylinders. wire saw. 5. The wire holding means includes a workpiece feeding means for feeding the workpieces in the running direction of the wire, a detection means for detecting the running position of the wire, and a detection means for moving the workpieces based on the detection result of the detection means. The wire saw according to claim 1, further comprising a control means for controlling the feeding of the material feeding means.