JP2000218493A - Wire saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire saw which can surely prevent leakage of machining fluid or cut chips during cutting of a workpiece and facilitate the maintenance thereof. SOLUTION: A double cover assembly for covering a machining chamber in which a grooved roller is provided, is composed of an inner cover and an outer cover 62. Further, a slide plate, a hinged door and a foldable door are provided in the inner cover, and a foldable door 94 and a slide door 96 are provided in the outer cover 62. Further, a wire cover is attached to a wire between the grooved roller and a wire reel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a wire saw.
In particular, the present invention relates to a wire saw for cutting brittle materials such as silicon, glass, and ceramic.

[0002]

2. Description of the Related Art A wire saw cuts a workpiece into a thin wafer by pressing an ingot while supplying a working liquid (slurry) to a wire row formed by winding wires around a plurality of groove rollers. It is a device to do. The wire saw covers the processing chamber in which the groove roller is installed with a cover, and prevents the slurry and cutting dust scattered during cutting from leaking to the outside of the wire saw. When the cutting of the ingot is completed, the cover is opened, the cut ingot is removed, and the processing chamber is cleaned.

[0003]

However, in the conventional wire saw, during cutting of the ingot, slurry or cutting dust leaks from a gap at the boundary between the body of the wire saw and the cover, thereby contaminating the outside of the wire saw. There are drawbacks. Further, in the conventional wire saw, since the slurry is scattered in the entire processing chamber, there is a disadvantage that a large amount of labor and time are required for cleaning the processing chamber.

The present invention has been made in view of such circumstances, and a wire saw capable of reliably preventing leakage of machining fluid and cutting dust during cutting of a workpiece and facilitating each maintenance. The purpose is to provide.

[0005]

According to the present invention, in order to achieve the above object, a wire between a pair of wire reels is wound around a plurality of groove rollers to form a wire array, and the wire is run and In a wire saw that cuts the workpiece into a number of wafers by pressing the workpiece held by a feeder against a cutting portion of the wire row while supplying a processing liquid to the wire row, the plurality of groove rollers are A cover for covering the installed processing chamber is formed as a double cover with an outer cover and an inner cover, and a pair of support plates supporting the plurality of groove rollers form a part of the inner cover. It is characterized by the following.

According to the first aspect of the present invention, since the cover for covering the processing chamber in which the plurality of groove rollers are installed is doubled with the outer cover and the inner cover, the cover is formed during cutting of the workpiece. Leakage of generated working fluid and cutting dust can be reliably prevented. Further, according to the first aspect of the present invention, since the pair of support plates supporting the plurality of groove rollers constitute a part of the inner cover, the volume of the inner cover can be reduced. This reduces the area in which the machining liquid or cutting dust scatters, so that the machining chamber can be easily cleaned.

According to the second aspect of the present invention, the inner cover has an opening for attaching the workpiece to the feeder, and an opening / closing member for opening and closing the opening. Therefore, the work of attaching the workpiece can be performed only by opening and closing the opening with the opening and closing member. According to the third aspect of the present invention, the inner cover has an opening for winding a wire around the plurality of groove rollers, and an opening / closing member for opening and closing the opening. Therefore, the wire winding operation can be performed only by opening and closing the opening with the opening and closing member.

According to the fourth aspect of the present invention, since a window through which the cut portion is visible is formed in the inner cover, the state of the cut portion can be easily grasped. According to the fifth aspect of the present invention, since the feeder is inserted into the inside of the inner cover from the upper opening of the inner cover, and the scraper is slidably attached to the inner wall of the inner cover. When the feeder is moved toward the wire row, the scraper removes the machining fluid and cutting dust attached to the side wall of the inner cover, preventing the machining fluid and cutting dust from leaking from the upper part of the inner cover. I do.

According to the sixth aspect of the present invention, since the inner cover is provided with a wire cover that covers the wire between the wire reel and the wire row, the machining liquid attached to the wire is scattered. Can be prevented.
According to the invention as set forth in claim 7, the outer cover is provided with an opening for exposing the inner cover and an opening / closing member for opening and closing the opening is provided. The inner cover can be exposed simply by opening and closing the cover. Thereby, the work of attaching the workpiece, the work of winding the wire, the visual recognition of the cut portion, and the like can be easily performed through the opening formed in the inner cover.

According to the invention described in claim 8, since the opening / closing member formed on the outer cover is supported by the outer cover above the opening / closing member, the opening / closing operation of the door is impaired by the fixation of the working fluid. Never be. According to the ninth aspect of the invention, since the workpiece can be cut only when all the doors formed on the outer cover are closed, the workpiece is cut in a state where the cut portion is exposed. Is not performed, and is excellent in safety.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the wire saw according to the present invention will be described below in detail with reference to the accompanying drawings. FIG.
It is a perspective view of the wire saw 10 of the embodiment of the present invention,
FIG. 2 is a perspective view in which main components of the wire saw main body 11 shown in FIG. 1 are exposed.

As shown in these figures, the wire saw 10
Is composed of a wire saw main body 11, a processing liquid supply device 44, a processing liquid recovery tank 40, a cleaning liquid tank 76, and an overflow tank 56. In the wire saw body 11,
A wire reel 12 is provided, and a wire 14 wound around the wire reel 12 has a large number of guide rollers 16, 16.
, Are wound around the four groove rollers 18A, 18B, 18C, 18D a plurality of times via the wire running path on one side, and the wires 14 form parallel wire rows 20. The wire 14 forming the wire row 20 is formed symmetrically with respect to the wire row 20 and wound on a wire reel (not shown) via the other wire running path having the same structure as the one wire running path. Can be

A wire guide device 22 and a dancer roller 24 are provided on each of the wire running paths formed on both sides of the wire array 20 (only one side is shown), and the wire 14 is moved by the wire guide device 22 to the wire reel 12. From a fixed pitch. A weight (not shown) of a predetermined weight is provided on the dancer roller 24, and a constant tension is applied to the traveling wire 14 by the weight. Further, a wire cleaning device (not shown) is provided on the wire traveling path, and a processing liquid (slurry) attached to the wire 14 is sprayed from the wire 14 by spraying a cleaning liquid onto the wire 14 traveling in the wire cleaning device. Removed.

The four groove rollers 18A to 18D around which the wire 14 is wound are rotatably supported by a pair of brackets 42, 42 at opposite ends thereof. It is arranged at a rectangular position. The pair of brackets 42, 42
It is installed above an oil pan 36 described later. The groove roller 18C and the pair of wire reels 12 are respectively driven by motors 26,
It is connected to. The wire 14 reciprocates at high speed between the pair of wire reels 12 by driving these motors 26 and 28.

A work feed table 30 (feeding device) is slidably mounted on a feed base 32 above and below the wire row 20 so as to be vertically slidable.
Work feed table 3 by motor 33 provided in
0 vertically moves with respect to the wire row 20. An ingot (not shown) is held below the work feed table 30 in a state where the crystal orientation is aligned.

An oil pan 36 is provided below the wire row 20, and the working fluid supplied to the wire row 20 is collected by the oil pan 36. An inclined surface is formed inside the oil pan 36, and a recovery pipe 38 (see FIG. 5) is connected to a lower end of the inclined surface. The recovery pipe 38 has a tip guided to the processing fluid recovery tank 40.
Thus, the working fluid collected in the oil pan 36 is stored in the working fluid collection tank 40 via the collection pipe 38.

The working fluid supply unit 44 is constructed by mounting a working fluid tank 46, a heat exchanger 50, a supply pump 52, a flow meter 54, and the like on a movable carriage 48. A pipe (not shown) is connected to the processing fluid tank 46, and a tip of the pipe is connected to the recovery pump 4 above the processing liquid recovery tank 40.
1 is detachably connected. Thus, the processing liquid stored in the processing liquid recovery tank 40 is pumped up by the recovery pump 41 and collected in the processing liquid tank 46. The processing liquid collected in the processing liquid tank 46 is supplied to a supply pump 52.
, And is sprayed onto the wire row 20 from a working fluid nozzle (not shown) installed above the wire row 20. The injected working fluid is collected by the oil pan 36 as described above, returned to the working fluid tank 46 via the working fluid recovery tank 40, and circulated and supplied. The working fluid circulated and supplied is adjusted to a constant temperature by the heat exchanger 50.

In the wire saw 10 configured as described above, the ingot is cut as follows. First, the ingot is held on the work feed table 30 with the crystal orientation aligned. Then, after the wire 14 reciprocates at a high speed, the work feed table 30 is lowered toward the wire row 20, and the ingot is pressed against the cut portion of the wire row 20. At this time, a processing liquid is supplied to a cut portion of the wire row 20 from a processing liquid tank 46 via a nozzle (not shown), and the ingot is subjected to a lapping action of abrasive grains contained in the processing liquid to form a plurality of wafers. Be cut off at once.

By the way, the inner cover 60 and the outer cover 62 cover the processing chamber for cutting the workpiece.
It is composed of two layers. FIG. 3 is a perspective view of the wire saw main body 11 shown in FIG. As shown in the figure, an outer cover 62 is provided on the wire saw main body 11, and the inside and the outside of the wire saw main body 11 are shut off by the outer cover 62. A folding door 94 is formed on the front of the outer cover 62 as viewed in the direction of arrow A in FIG. 3, and sliding doors 96 are formed on the left and right side surfaces, respectively. The outer cover 62 opens the folding door 94 or the sliding door 96 to open the inner cover 6.
0 is configured to be exposed. 114 is the outer cover 6
The door is detachably attached to the work feed table 2, and is removed when the work feed table 30 is maintained. The specific configuration of the folding door 94 and the sliding door 96 will be described later in detail.

FIG. 4 is a perspective view showing the inner cover 60, and FIG. 5 is a perspective view in which doors formed on the inner cover 60 shown in FIG. 4 are opened. The inner cover 60 shown in FIG.
The front surface of the inner cover 60 is formed in a box shape, and is formed by one of the pair of brackets 42, 42 and a front plate 64 as viewed in the direction of arrow A in FIG. The front plate 64 includes the bracket 4
The slide plate 68 is attached to the columns 66, 66 supported by the support 2 and the lower part at the center. The slide plate 68 is
It is attached to the front plate 64 via the guide rails 70 on both sides, and is slidably installed in the vertical direction. The slide plate 68 is provided with a fixing screw 72, and the slide plate 68 is slid upward and screwed into the screw hole 74 formed in the front plate 64, as shown in FIG. As described above, the slide plate 68 can be fixed upward to form the window 76 in which the cut portion can be viewed.

The left and right sides of the inner cover 60 are constituted by a hinged door 78, a folding door 80, a wire cover 82 and a side plate 84, respectively. The side plate 84 is provided at the lower end of the pair of brackets 42, 42, and the lower end is in close contact with the oil pan 36. A wire cover 82 is attached to an upper portion of the side plate 84. The wire cover 82 is configured to cover the wire 14 between the wire reel 12 and the groove rollers 18A to 18D, and includes a cover 88 and a cover 89. The cover 88 is detachably mounted on a fixed plate 86 protruding from the bracket 42. The cover 89 includes a lower cover 89B formed in a concave cross section and an upper cover 8 that covers the lower cover 89B.
9A, the upper cover 89A is attached to the fixed lower cover 89B so as to be rotatable in the direction of arrow 93. Accordingly, the wire 14 between the groove rollers 18A to 18D and the wire reel 12 can be exposed by removing the cover 88 from the fixing plate 86 and rotating the upper cover 89A.

A folding door 80 is provided above the wire cover 82. The folding door 80 includes a pair of upper and lower plates 8.
0A, 80B attached by hinges, and the lower plate 8
0A is detachably attached to the bracket 42 by a screw member or the like. Thereby, the folding door 80
The upper plate 80A can be rotated in the direction of arrow 91, and the lower plate 80B is
And the folding door 80 itself can be removed.

A swing door 78 is provided above the folding door 80. The hinged door 78 includes a right swing door 78A and a left swing door 78B, and the right swing door 78A and the left swing door 78B are rotatably attached to columns 66, 66 supported by the bracket 42, respectively. In addition, the right swing door 78A and the left swing door 78B are each configured by hingedly attaching two left and right plates. This allows
Each of the right swing door 78A and the left swing door 78B can be opened while being folded as shown in FIG.

The upper part of the folding door 80 is configured to overlap the lower part of the hinged door 78. Thus, when the folding door 80 is closed after the closing of the hinged door 78, the opening and closing of the hinged door 78 can be locked by the folding door 80. In addition, by rotating the upper plate 80A of the folding door 80 in the direction of the arrow 91 and opening the hinged door 78, a large opening can be formed around the wire row 20 as shown in FIG. As a result, the ingot is inserted through the opening and the work feed table 30 is inserted.
Can be attached to

The back surface of the inner cover 60 is composed of the other bracket 42 and the feed base 32. As described above, the work feed table 30 is installed on the feed base 32 so as to be slidable in the vertical direction. By driving the motor 33, the work feed table 30 is inserted into a cylindrical side wall formed by the front, left and right side surfaces, and the back surface of the inner cover 60.
At the lower end of the work feed table 30, brushes 90 are attached to the front and left and right side surfaces as scrapers, so that the brush 90 slides on the side wall when the work feed table 30 is inserted into the side wall.
As a result, when the work feed table 30 is moved up and down, the brush 90 wipes off the working fluid attached to the front and left and right side surfaces, thereby preventing leakage of the working fluid and cutting dust from the gap between the work feed table 30 and the side wall. can do.

The lower surface of the inner cover 60 is formed by an oil pan 36. That is, as described above, the pair of brackets 42 are mounted on the oil pan 36, and the side plate is in close contact with the oil pan 36. As a result, the lower surface of the inner cover 60 is sealed except for the connection between the oil pan 36 and the recovery pipe 38.

As described above, the inner cover 60 of the wire saw 10
Surrounds the cut portion by the upper surface, the lower surface, the front surface, the left and right side surfaces, and the rear surface, so that the machining fluid and
Does not leak. Hereinafter, the above-described outer cover 62
The folding door 94 and the sliding door 96 will be described in detail. FIG.
It is explanatory drawing explaining the structure of the folding door 94, and is sectional drawing of the right end part of the board 94B of the right side of the folding door 94.

The folding door 94 is formed at the front of the outer cover 62 as viewed in the direction of arrow A in FIG. 3, and is configured so that the front of the inner cover 60 is exposed by opening the folding door 94. The folding door 94 is composed of two left and right plates 94A and 94B that are hinged, and the left plate 94A is rotatably attached to the outer cover 62. Further, as shown in FIG. 6, a support bar 97 is attached to the right end of the right plate 94B, as shown in FIG. A rotation shaft 95 is rotatably supported by the support rod 97 in the direction of arrow 99, and a roller 98 is attached to the rotation shaft 95 by an arrow 101.
It is supported rotatably in the direction. In addition, the outer cover 62
A rail 100 is formed above the folding door 94,
The roller 98 is configured to engage with the rail 100 to travel. Also, the folding door 9 of the outer cover 62
A groove 102 is formed at the lower part of the plate 4 so that a round bar 104 attached to a lower end of the right plate 94B is engaged.

The folding door 94 thus configured is
As shown in FIG. 3, the inner cover 60 is opened while being folded to expose the front surface of the inner cover 60. Thus, by opening the folding door 94, the cut portion can be visually recognized from the window 76 of the slide plate 68, and maintenance around the bracket 42 can be performed. Further, since the folding door 94 is supported by the outer cover 62 at the upper portion, the working fluid attached to the rail 100 does not adhere to the folding door 94 and does not hinder the opening and closing of the folding door 94.

FIG. 7 is a structural view of the sliding door 96 of the outer cover 62. The sliding doors 96 of the outer cover 62 are formed on the left and right side surfaces of the wire saw main body 11, respectively, and include four plates 96.
A, 96B, 96C, and 96D. Each board 96
Rollers 106 are rotatably supported on the upper portions of A to 96D, respectively, as shown in FIG. The outer cover 62 is formed with four rails 108, 108,. Further, a groove 110 is formed on the lower surface of each of the plates 96A to 96D. The outer cover 62 has a ridge 111 that engages with the groove 110. Thereby, each plate 96A-96D of the sliding door 96 becomes slidable in the direction of arrow 112, and as shown by the solid line in FIG.
6A to 96D can be overlapped in one place, and the left and right side surfaces of the inner cover 60 can be exposed. Further, since each of the plates 96A to 96D of the sliding door 96 is supported on the upper part by the outer cover 62, even if the processing liquid adheres to the sliding door 96 and the abrasive grains in the processing liquid adhere, the opening and closing of the sliding door 96 is performed. Operation is not impaired.

The sliding door 96 has an open / close sensor 12.
0, the folding door 94 is provided with an opening / closing sensor 122, and the CPU 124 performs interlock control.
FIG. 8 is a block diagram illustrating a control system of the wire saw 10. The sensor 120 can output a signal indicating the information to the CPU 124 when the sliding door 94 is completely closed. Similarly, the sensor 122 can output the information when the folding door 94 is completely closed. Can be output to the CPU 124. The CPU 12
Reference numeral 4 denotes each motor 2 which is a driving source of the wire saw 10 only when the information is output from both the sensors 120 and 122.
6, 28, 33, each motor 26,
Drives 28 and 33 are controlled. Therefore, sliding door 9
6. When one of the folding doors 94 is open, the start switch 126 of the wire saw 10
Is turned on, the wire saw 10 is not started and the sliding door 9 is turned on.
6. The wire saw 10 is started only when the folding door 94 is closed. Thereby, the safety of the worker by opening the sliding door 96 and the folding door 94 is achieved.

As described above, in the wire saw 10 of the present embodiment, the cutting portion for cutting the ingot is covered by the inner cover 60 and the outer cover 62, so that the machining fluid and the cutting dust during the cutting of the ingot are cut. Leakage can be reliably prevented. Further, since the inner cover 60 is configured to surround the cut portion using the brackets 42, 42, the volume of the inner cover 60 is reduced. This reduces the scattering area of machining fluid and cutting dust,
Cleaning work can be easily performed. Also, the inner cover 6
As the volume of 0 becomes smaller, the scattering area of the processing liquid whose temperature has increased becomes smaller, so that it is possible to prevent thermal deformation of equipment outside the processing chamber.

The inner cover 60 and the outer cover 62 of the wire saw 10 according to the present embodiment have windows and doors of appropriate shapes formed at appropriate positions, so that a work to attach a workpiece, a work to wind a wire, In addition, it is possible to easily recognize the cut portion. Hereinafter, each operation will be described separately. In the ingot mounting operation, first, the sliding door 96 of the outer cover 62 is slid and overlapped at one place to expose the left and right side surfaces of the inner cover 60. Then, after the upper plate 80A of the folding door 80 of the inner cover 60 is rotated to unlock the hinged door 78, the hinged door 78 is opened right and left. Thereby, the periphery of the wire row 20 can be exposed, and the ingot can be inserted above the wire row 20 and attached to the lower portion of the work feed table 30. As described above, the portion necessary for the ingot mounting operation can be easily exposed, so that the ingot mounting operation can be easily performed.

The winding operation of the wire 14 is performed when the worn wire 14 is replaced or when the worn groove roller 18 is replaced.
This is performed when replacing A to 18D. In this case, first, the sliding door 96 of the outer cover 62 is slid and overlapped at one place to expose the left and right side surfaces of the inner cover 60. Then, after the folding door 80 is removed from the bracket 42, the hinged door 78 is opened, and each of the groove rollers 18A to 1A is opened.
Expose 8D. Then, the wire cover 82 is removed, and the wire cover 89A is rotated in the direction of arrow 91,
The wire 14 between the wire reel 12 and the groove rollers 18A to 18D is exposed. Thereby, the wire 14 between the wire reel 12 and the groove rollers 18A to 18D and the wire 14 wound around the groove rollers 18A to 18D can be exposed, and the work of replacing the wire 14 can be easily performed. it can.

The cut portion of the wire row 20 is visually recognized, for example, when checking whether the machining liquid is being supplied to the wire row 20 before cutting the ingot or when checking the cutting state during cutting of the ingot. Will be in this case,
First, the folding door 94 of the outer cover 62 is opened and the inner cover 60 is opened.
Expose the front of At this time, the folding door 94 of the outer cover 62 protrudes outside the wire saw 10, but since this protruding portion is located above the working fluid recovery tank 40 and the like, it is not necessary to separately secure a space for that portion. Then, the slide plate 68 exposed by folding the folding door 80 is slid upward to check the appearance of the cut portion of the wire row 20. In this manner, by simply opening the folding door 94 and sliding the slide plate 68, the cut portion of the wire row 20 can be easily visually recognized. If long-term visual recognition is necessary, the fixing screw 72 is screwed into the screw hole 74,
The slide plate 68 may be fixed upward.

As described above, the wire saw 1 according to the present embodiment
In the case of No. 0, since doors and windows of an appropriate shape are formed in the appropriate positions of the outer cover 62 and the inner cover 60, it is possible to easily perform the work of attaching the ingot, the work of winding the wire 14, and the work of visually confirming the cut portion. it can. In addition, when performing maintenance on devices around the cutting section, the inner cover 60 may be used as necessary.
The work can be easily performed by opening the door or window formed on the outer cover 62 or the outer cover 62. For example, when performing maintenance on the bracket 42, the bracket 42 is largely exposed only by opening the folding door 94 of the outer cover 62, so that the work can be easily performed.

The doors and windows formed on the inner cover 60 and the outer cover 62 are not limited to the above-described embodiment.

[0038]

As described above, according to the wire saw of the present invention, since the cover for covering the cutting portion for cutting the workpiece is doubled, the leakage of the working fluid and the cutting dust can be surely prevented. Can be prevented. Further, according to the wire saw of the present invention, since the pair of support plates supporting the groove roller constitute a part of the inner cover, the capacity of the inner cover can be reduced, and the scattering area of the machining liquid can be reduced. Can be smaller. Thereby, the cleaning operation of the working fluid can be facilitated, and the thermal influence of the working fluid can be prevented. Further, according to the present invention, since doors and windows having an appropriate structure are formed at appropriate positions on the inner cover and the outer cover, it is possible to easily perform operations such as winding a wire and attaching an ingot.

[Brief description of the drawings]

FIG. 1 is a perspective view of a wire saw according to an embodiment of the present invention.

FIG. 2 is a perspective view of the wire saw exposing components of the wire saw main body shown in FIG. 1;

FIG. 3 is a perspective view showing an outer cover of the wire saw shown in FIG. 1;

FIG. 4 is a perspective view of an inner cover of the wire saw according to the embodiment of the present invention.

FIG. 5 is a perspective view in which doors and windows formed on the inner cover shown in FIG. 4 are opened.

FIG. 6 is an explanatory view illustrating the structure of the folding door shown in FIG.

FIG. 7 is an explanatory view illustrating the structure of the sliding door shown in FIG.

FIG. 8 is a block diagram showing a control system of the wire saw according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Wire saw 14 ... Wire 20 ... Wire row 42 ... Bracket 60 ... Inner cover 62 ... Outer cover 68 ... Slide plate 78 ... Spring door 80 ... Folding door (of inner cover) 82 ... Wire cover 94 ... Folding door (of outer cover) 96 ... Sliding door

Claims (9)

[Claims] 1. A wire array formed by winding a wire between a pair of wire reels around a plurality of groove rollers, running the wires and supplying a working fluid to the wire arrays while holding a wire by a feeder. A wire saw for cutting the workpiece into a number of wafers by pressing the workpiece against the cutting portion of the wire row, wherein a cover covering a processing chamber in which the plurality of groove rollers are installed is an outer cover and an inner cover. And a pair of support plates that support the plurality of groove rollers form a part of the inner cover. 2. An inner cover having an opening for attaching the workpiece to the feeder and an opening / closing member for opening and closing the opening. 1. The wire saw according to 1. 3. An inner cover having an opening for winding a wire around the plurality of groove rollers and an opening / closing member for opening and closing the opening. Item 3. The wire saw according to item 1 or 2. 4. The wire saw according to claim 1, wherein a window through which the cut portion is visible is formed in the inner cover. 5. A scraper which is inserted into the inner cover from an upper open portion of the inner cover and which is slidably contacted with an inner wall of the inner cover. The wire saw according to 1, 2, 3, or 4. 6. The inner cover is provided with a wire cover for covering a wire between the wire reel and the plurality of groove rollers.
The wire saw according to 3, 4 or 5. 7. An outer cover is provided with an opening for exposing the inner cover, and an opening / closing member for opening and closing the opening.
The wire saw according to 4, 5, or 6. 8. The wire saw according to claim 7, wherein the opening / closing member formed on the outer cover is supported by the outer cover above the opening / closing member. 9. The wire saw according to claim 7, wherein the workpiece can be cut only when all the doors formed on the outer cover are closed.