JP2001179535A - Band sawing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely pinch a band saw blade while smoothly putting the band saw blade in/out of a guide part of an intermediate saw blade guide. SOLUTION: An intermediate saw blade guide 31 can be moved in a direction opposite to a cutting direction of a band saw blade 23 in relation to a material to be cut, and a guide part 41 of a tip can be removed from the band saw blade. The guide part 41 of the tip of the intermediate saw blade guide 31 is formed of a first and a second saw blade pinching members 53, 57 for pinching the band saw blade from the thickness direction, and at least one band saw pinching member 57 of both the first and the second saw blade pinching members 53, 57 can be moved for opening and closing in relation to the other saw blade pinching member 53. The band saw blade removed from between both the first and the second saw blade pinching members 53, 57 can be easily inserted for pinching by opening between the first and the second saw blade pinching members 53, 57.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a band saw provided with two saw blade guides for guiding a band saw blade and a third intermediate saw blade guide for guiding the band saw blade between the two saw blade guides. About the board.

[0002]

2. Description of the Related Art Conventionally, as a band saw machine, for example, a horizontal band saw machine generally has a structure shown in FIG.

[0003] That is, the horizontal band sawing machine 101 includes a box-shaped base 103, and the work table 10 for supporting, for example, an H-shaped steel as an example of the work material W is provided on the base 103.
5 is provided, and the work material W is
A fixed vise 107 serving as a position reference for the workpiece W and a movable vise 109 movable to the left and right directions approaching and moving away from the fixed vise 107 in order to fix the work W at the predetermined position.
Is provided.

The base 103 is provided with a saw blade housing 113 that can swing up and down via a hinge shaft 111. In order to swing the saw blade housing 113, an elevating cylinder 115 is provided at an appropriate position on the base 103, and a piston rod 117 that can freely project upward from the elevating cylinder 115 is
3 at appropriate positions.

A drive wheel 119 and a driven wheel 121 are rotatably provided in the saw blade housing 113. An endless band saw blade 123 is wound around the drive and driven wheels 119 and 121. The drive wheel 119 is a rotary drive device such as a motor (not shown).
It is linked and linked.

A guide bar 125 as a guide member attached to the saw blade housing 113 has a guide bar 125 attached to the saw blade housing 113 in order to maintain the direction of the tip of the band saw blade 123 substantially perpendicular to the work material W supported on the work table 105. A fixed saw blade guide 127, which is one of the fixed saw blade guides, and a movable saw blade guide 129, which is the other saw blade guide that can move in the left-right direction, approaching and separating from the fixed saw blade guide 127, are provided. Have been.

[0007] An intermediate saw blade guide 131 is provided between the fixed saw blade guide 127 and the movable saw blade guide 129 so as to be adjustable in position on a guide bar 125. Is provided at a lower end by its own weight at all times, and the band saw blade 123 is sandwiched and supported by a guide portion 133 at the lower end of the intermediate saw blade guide 131. The guide portion 133 is a fixed groove type guide having an appropriate clearance with respect to the saw thickness of the band saw blade 123.

Therefore, the work material W is moved by the work table 105 by the pair of fixed vice 107 and movable vise 109.
At a predetermined position. Driven by the rotation drive device, the driven wheels 119 and 121 are rotated to rotate the band saw blade 1.
23 is driven. The saw cylinder housing 113 is swung downward by the operation of the lifting cylinder 115. The band saw blade 123 is guided by a pair of fixed saw blade guides 127, moving saw blade guides 129, and intermediate saw blade guides 131, with the root thereof held vertically with respect to the work material W.
As a result, the work material W is cut.

Along with this cutting, the saw blade housing 11
3 is swung downward, the intermediate saw blade guide 131
The lower end of the blade abuts on the upper surface of the work material W to stop the lowering operation.
Is lowered, and as shown in FIG.
23 comes out of the guide portion 133 at the lower end of the intermediate saw blade guide 131.

After the cutting operation is completed, when the saw blade housing 113 is moved upward by the operation of the elevating cylinder 115, the band saw blade 123 is guided by the guide portion 133 at the lower end of the intermediate saw blade guide 131.
And the saw blade housing 113 stops at the rising end.

[0011]

By the way, in the conventional horizontal band sawing machine 101, the band saw blade 123 comes out of the guide portion 133 of the intermediate saw blade guide 131 during the cutting process, and returns to the guide portion 133 after the cutting process is completed. When trying, since the guide portion 133 of the intermediate saw blade guide 131 is of a fixed groove type, it cannot be returned and is caught, and pushes up the whole of the intermediate saw blade guide 131 or the band saw blade 1.
There has been a problem that 23 itself comes off from the other fixed saw blade guide 127 and moving saw blade guide 129.

If the groove width of the guide portion 133 of the intermediate saw blade guide 131 is widened, the above-described troubles can be solved. In this case, however, the intermediate saw blade guide 131 does not function. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to smoothly move a band saw blade into and out of a guide portion of an intermediate saw blade guide, and to provide an intermediate member for securely holding the band saw blade. An object of the present invention is to provide a band sawing machine capable of achieving both functions of a saw blade guide.

[0014]

According to a first aspect of the present invention, there is provided a band sawing machine according to the present invention, which rotatably supports a driven wheel and a driven wheel around which an endless band saw blade is wound and has a cover. Two saw blade guides each having a guide portion for guiding the band saw blade at a distal end thereof are provided in a saw blade housing that is movable in a direction of cutting into a work material, and the band saw blade is guided between the two saw blade guides. In a band sawing machine provided with an intermediate saw blade guide having a guide portion at a tip portion, the intermediate saw blade guide can be moved relative to the saw blade housing in a direction opposite to a direction in which the band saw blade cuts a work material. And the guide part of the tip part is provided so as to be detachable from the band saw blade, and the guide part of the tip part of the intermediate saw blade guide is composed of first and second saw blade holding members for holding the band saw blade in the thickness direction, This first, At least the first saw blade holding member can be freely opened and closed with respect to the second saw blade holding member so that the band saw blade detached from between the two saw blade holding members is inserted and held again between the first and second saw blade holding members. The opening and closing movement means is provided.

Therefore, since the band saw blade is always held between the two saw blade guides and the first and second saw blade holding members at the distal end of the intermediate saw blade guide, the band saw blade is held against the work material. It is guided vertically and cuts in a stable state. Since the guide portion at the tip of the intermediate saw blade guide comes into contact with the work material during cutting, the band saw blade moves from the guide portion of the intermediate saw blade guide as the band saw blade moves further in the direction of cutting the work material. Get out. At the end of the cutting process, at least the first saw blade holding member moves and the space between the first and second saw blade holding members is widely opened, so that when the band saw blade returns to the original position, the band saw blades are moved to the first and second positions. It is smoothly inserted between the two saw blade holding members. Then, at least the first saw blade holding member moves, and the band saw blade is reliably held between the first and second saw blade holding members.

According to a second aspect of the present invention, in the band sawing machine according to the first aspect, the opening / closing movement means includes a first saw blade holding member on the first saw blade holding member side and a second saw blade holding member. And a reciprocating fluid pressure cylinder which is driven forward and backward.

Therefore, the first saw blade holding member can be easily opened and closed toward the second saw blade holding member by the reciprocally movable hydraulic cylinder.

According to a third aspect of the present invention, in the band sawing machine according to the first aspect, the opening and closing movement means includes a first saw blade holding member on the first saw blade holding member side and a second saw blade holding member. And a biasing means for pressing the first saw blade holding member against the forward or backward direction of the hydraulic cylinder. It is.

Therefore, the first saw blade holding member is normally urged by the urging means in the forward or backward direction toward the second saw blade holding member, but only by controlling the fluid pressure cylinder in one direction. Thus, the first saw blade holding member is easily opened and closed toward the second saw blade holding member.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings. Although a horizontal band saw machine was adopted as the band saw machine, the present invention is not limited to this model, and a vertical band saw machine or the like is also possible. Illustration and description are omitted. In this embodiment, H is used as the material to be cut.
Although the description will be made with reference to a section steel, for example, a channel section steel or the like may be used, and the invention is not limited to the above materials.

Referring to FIG. 4, a horizontal band sawing machine 1 used in the present embodiment includes a box-shaped base 3.
Is provided with a work table 5 for supporting, for example, an H-section steel as an example of the work material W, and the work material W
Is fixed to a predetermined position on the work table 5, a fixed vise 7 serving as a position reference of the work W, and a movement movable in the left and right direction (the left and right direction in FIG. 4) approaching and moving away from the fixed vise 7 A vise 9 is provided.

The base 3 is provided with a saw blade housing 13 which can swing up and down via a hinge shaft 11. In order to swing the saw blade housing 13, an elevating cylinder 15 is provided at an appropriate position on the base 3.
A piston rod 17 that can project upward from the lift cylinder 15 is connected to an appropriate position of the saw blade housing 13.

The drive wheel 1 is housed in the saw blade housing 13.
9 and a driven wheel 21 are rotatably provided, and an endless band saw blade 23 is wound around the driving and driven wheels 19 and 21. And the drive wheel 19
Is linked to a rotary drive device (not shown) such as a motor.

A guide bar 25 as a guide member attached to the saw blade housing 13 has a guide bar 25 attached to the saw blade housing 13 in order to maintain the direction of the tip of the band saw blade 23 substantially perpendicular to the work material W supported on the work table 5. A fixed saw blade guide 27, which is one of the fixed saw blade guides, and the fixed saw blade guide 2
A moving saw blade guide 29 is provided, which is the other saw blade guide that can move in the left-right direction that approaches and separates from the moving blade 7. Saw blade guides 27G and 29G for guiding and supporting the band saw blade 23 are provided at the distal ends of the two saw blade guides 27 and 29, respectively.

With the above configuration, the workpiece W is fixed at a predetermined position on the work table 5 by the pair of fixed vice 7 and movable vise 9. The driving and the driven wheels 19 and 21 are rotated by the driving of the rotary driving device, and the band saw blade 23 is driven to travel. The saw blade housing 13 swings downward by the operation of the lifting cylinder 15. The band saw blade 23 includes a pair of fixed saw blade guides 27 and a movable saw blade guide 29, and the work material W
The tooth root is held vertically and is guided with respect to the band saw blade 2.
By 3, cutting (cutting) of the work material W is performed.

Referring again to FIG. 4, the fixed saw blade guide 2
An intermediate saw blade guide 31 is provided between the movable saw blade guide 7 and the movable saw blade guide 29 so as to be adjustable in position on a guide bar 25 as a guide member.
Thus, the band saw blade 23 is guided and supported. The intermediate saw blade guide 31 is configured to move along the guide bar 25 by rotation of a screw rod 35 (ball screw) rotated by a drive motor 33 such as a servomotor.

The above-mentioned intermediate saw blade guide 31 will be described in more detail. Referring to FIGS. 5 and 6, FIG. 5 shows the intermediate saw blade guide 31 of the horizontal band sawing machine shown in FIG. It is the drawing which looked at the part from the back side.

Referring to FIG. 5, the intermediate saw blade guide 31 includes an intermediate saw blade guide body 37 as a guide member that is movable in the longitudinal direction of the guide bar 25 along the guide bar 25, for example. A guide body 39 is provided in the blade guide body 37 so as to be movable up and down (in a direction intersecting with the guide member). The guide body 39 has a leading end serving as a guide section for guiding and supporting the band saw blade. For example, a saw blade guide portion 41 is provided.

The intermediate saw blade guide body 37 is provided with the guide bar 2.
5, a plurality of guide rails 43 provided to extend in the longitudinal direction.
Is provided so as to be movable in the left-right direction and adjustable in position through a plurality of guides 45. The drive system for moving the intermediate saw blade guide body 37 includes a guide bar 25.
A screw rod 35 operatively connected to a drive motor 33 provided on the lifting cylinder 15 side is provided in parallel with the guide rail 43, and a nut member 47 screwed to the screw rod 35 is integrated with the intermediate saw blade guide body 37. It is provided in.

When the driving motor 33 is driven, the screw rod 35 rotates, and the intermediate saw blade guide body 37 is moved in the left-right direction along the guide bar 25 via the nut member 47 screwed to the screw rod 35. Moved to and positioned.

On both sides of the guide main body 39, guide rails 51 engaged with a plurality of vertical guides 49 provided on the intermediate saw blade guide main body 37 are provided extending vertically.
The guide body 39 is vertically movable by its own weight with respect to the intermediate saw blade guide body 37.

Next, the saw blade guide portion 4 provided at the lower end of the intermediate saw blade guide 31 constituting the main part of the embodiment of the present invention.
1 will be described in detail.

Referring to FIG. 1, FIG. 2 and FIG. 3, a saw blade guide portion 41 provided at the lower end of the guide body 39 has two opposing faces for sandwiching the band saw blade 23 from the thickness direction of the band saw blade 23. And at least one of the saw blade holding members is configured to be freely opened and closed with respect to the other saw blade holding member.

The saw blade guide portion 41 includes, for example, a plurality of bolts on one side of a groove 55 formed at the lower end of the guide body 39 by, for example, a fixed insert 53 as one saw blade holding member (second saw blade holding member). For example, a moving side insert 57 as another saw blade holding member (first saw blade holding member) capable of pressing the band saw blade 23 in opposition to the fixed side insert 53 is provided in addition to the groove 55. The movable side insert 57 is configured to be able to pinch or release the band saw blade 23 by, for example, a small cylinder 59 operated by fluid pressure.

The cylinder body 61 of the small cylinder 59 is
The groove 55 of the guide main body 39 is fixed to the outside of the left guide side piece 63 in FIG. 1, and the piston rod 65 of the small cylinder 59 is fixed to the guide side piece 63.
The piston rod 65 is inserted into a through hole 67 and protrudes into the groove 55, and a moving-side insert 57 is integrally screwed to the tip of the piston rod 65.

A spring chamber 7 in which, for example, a coil spring 69 as urging means for urging in the opposite direction against the pressing force of the piston rod 65 is mounted on the guide side piece 63.
1 is provided, and in the present embodiment, the piston rod 65 is configured to pass through a coil spring 69 housed in a spring chamber 71. A flange 73 is protruded from the outer periphery substantially at the center of the piston rod 65, and the piston rod 65 is constantly urged leftward in FIG. 1 by the urging force of the coil spring 69 via the flange 73. That is, the moving side insert 57
Are always urged in the direction of opening away from the fixed insert 53.

Further, a stepped portion 75 is formed on the left side wall surface of the groove portion 55 of the guide body 39 in FIG. 1, and the movable side insert 57 of the small-sized cylinder 59 within the range of the stroke S of FIG. , The upper surface slides on the upper wall surface of the stepped portion 75 and is guided.

In addition, as shown in FIG. 1, a part of the fixed side insert 53 or the lower end of the guide side piece 63 of the guide body 39 is normally closer to the work side than the tooth base of the band saw blade 23. It is projected as preceding. Therefore, when the work W is cut, the protrusion of the fixed-side insert 53 or the guide-side piece 63 of the guide body 39 is used.
Forms a workpiece abutment part, and the workpiece W
It is a structure that comes into contact with

With the above configuration, the operation is as shown in FIG.
, The intermediate saw blade guide body 37 is located substantially at an intermediate position between the fixed saw blade guide 27 and the movable saw blade guide 29,
The guide body 39 is located at the lower limit, and the guide body 3
The band saw blade 2 is provided by the saw blade guide 41 provided at the lower end of the band saw 9.
No. 3 is guided by pinching.

That is, in FIG. 1, fluid pressure is supplied into the pressurizing chamber 77 of the small cylinder 59 and the piston rod 65
1 is pressed rightward in FIG. 1 against the urging force of the coil spring 69 and moves.
7 approaches the fixed side insert 53, and the band saw blade 23 is sandwiched between the moving side insert 57 and the fixed side insert 53.

The piston rod 65 is connected to the flange 7
3 comes into contact with the left end surface of the spring chamber 71 in FIG. 1 and stops, so that the distance between the moving side insert 57 and the fixed side insert 53 in the state of the stop position is the band saw blade 23.
Is desirably set in advance so as not to press strongly.

As described above, when the saw blade housing 13 is lowered in the direction of the work W in order to cut the work W while the band saw blade 23 is being nipped and guided by the saw blade guide portion 41 of the intermediate saw blade guide 31. Then, one flange portion of the H-section steel as the work material W is cut by the band saw blade 23. The saw blade housing 13 further lowers continuously and the cutting process proceeds, and the saw blade guide portion 41 provided at the lower portion of the guide body 39
When the lower end of the guide body 39 contacts the upper surface of the web of the workpiece W, the lowering operation of the guide body 39 stops at the upper surface of the web.

Since the saw blade housing 13 descends further continuously and the band saw blade 23 descends together with the fixed saw blade guide 27 and the moving saw blade guide 29, the guide body 39 is moved to the band saw blade 23.
Relative to When the band saw blade 23 further descends and cuts into the workpiece W, the guide body 39 further rises relatively, and the band saw blade 23 separates from the saw blade guide portion 41 of the guide body 39 and further descends.

Further, the cutting of the work W proceeds and the band saw blade 2
When 3 reaches the lower end and the cutting is completed, the end of cutting is detected by a sensor (not shown), and the band saw blade 23 moves upward.

At this time, the fluid pressure of the pressurizing chamber 77 of the small cylinder 59 is discharged from the moving insert 57 of the saw blade guide portion 41 provided in the guide body 39 by a switching valve (not shown) such as a solenoid valve. As a result, the pressure in the pressurizing chamber 77 is reduced, and the piston rod 65 is moved to the left in FIG. 1 by the urging force of the coil spring 69. Opened in a clamped state.

When the band saw blade 23 rises as the saw blade housing 13 rises, the guide body 39 is lowered relative to the band saw blade 23 by its own weight. In other words, even if the saw blade housing 13 is raised, the guide side piece 63 at the lower end of the guide body 39 and the lower end of the fixed insert 53 are in contact with the upper surface of the web of the workpiece. Therefore, the raised band saw blade 23 is easily and reliably inserted between the inserts 53 and 57 in the unclamped state.

When the band saw blade 23 is further raised, the guide body 39 is at the lower limit position and the band saw blade 23 is
57 and is raised together with the saw blade housing 13 while being inserted. And the small cylinder 59
When the fluid pressure is supplied into the pressurizing chamber 77, the band saw blade 23 is clamped so as to be sandwiched again by the inserts 53 and 57, and the next cutting operation is performed.

Next, another embodiment of the intermediate saw blade guide 31 will be described. Note that components having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

Referring to FIG. 7, the moving side insert 57
Is a piston rod 81 of a small cylinder 79 that can reciprocate freely.
And is configured to be reciprocally movable. Control is performed such that fluid pressure is alternately supplied to the pressurizing chamber 83 and the back pressure chamber 85 of the small cylinder 79 by an electromagnetic valve 87.

Therefore, the movable insert 57 can be easily opened and closed with respect to the other fixed insert 53 by the small cylinder 79.

In the embodiment shown in FIGS. 1 and 7, the right side is the fixed side insert 53 and the left side is the movable side insert 57 in FIGS. 1 and 7, but the reverse is also possible. Absent.

Further, as shown in FIG. 8, both the inserts on both sides as the first and second saw blade holding members may be constituted by the movable inserts 89. For example, in FIG. 8, both side inserts 89 are connected to the piston rod 81 of the small cylinder 79 which can reciprocate and can reciprocate synchronously, similarly to the moving side insert 57 shown in FIG. The pressure chamber 83 and the back pressure chamber 85 of the two small cylinders 79 are controlled so that fluid pressure is alternately supplied by one electromagnetic valve 87.

The drive mechanism of the movable insert 57 shown in FIG. 1 is such that the movable insert 57 is constantly biased by the biasing force of the coil spring 69 in a direction in which the movable insert 57 is opened with respect to the fixed insert 53. Conversely, the moving-side insert 57 is constantly biased by the biasing force of the coil spring 69 in a direction in which it is closed with respect to the fixed-side insert 53, and the small cylinder 59 is opened against the biasing force of the coil spring 69. May be configured to be controlled.

In the combination of the biasing force of the coil spring 69 and the small cylinder 59 as described above, the moving side insert 57 normally moves forward or backward toward the other fixed side insert 53 by the biasing force of the coil spring 69. The movable side insert 57 can be easily opened and closed with respect to the other fixed side insert 53 simply by controlling the piston of the small cylinder 59 in one direction.

1, 7 and 8, the drive mechanism for the moving inserts 57 and 89 is a combination of the small cylinder 59 and the coil spring 69 of the embodiment shown in FIG. Or a reciprocating small cylinder 7 according to the embodiment of FIG.
9 may be used.

The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes.

[0057]

As will be understood from the above description, according to the first aspect of the present invention, the band saw blade is always provided with two saw blade guides and the first and second end portions of the intermediate saw blade guide. Since it is held by the saw blade holding member, it can be cut by the band saw blade which is guided vertically to the work material and is stable. The band saw blade comes out of the guide portion of the intermediate saw blade guide because the guide portion at the tip of the intermediate saw blade guide comes into contact with the work material at the time of cutting, but at the end of the cutting process, at least the first saw blade is held. Move the member and
Since the space between the second saw blade holding members can be widely opened,
When the band saw blade returns to the original position, the band saw blade can be smoothly inserted between the first and second saw blade holding members, and no trouble occurs. Then, by moving at least the first saw blade holding member, the band saw blade can reliably hold the band saw blade with the first and second saw blade holding members.

According to the second aspect of the present invention, the first saw blade holding member can be easily opened and closed toward the second saw blade holding member by the reciprocally movable fluid pressure cylinder.

According to the third aspect of the present invention, the first saw blade holding member is normally urged by the urging means in the direction of moving forward or backward toward the second saw blade holding member. By simply controlling the cylinder in one direction, the first saw blade holding member can be easily opened and closed toward the second saw blade holding member.

[Brief description of the drawings]

FIG. 1 is a side view of a guide portion provided on an intermediate saw blade guide according to an embodiment of the present invention.

FIG. 2 is a bottom view taken along line II-II in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a front view of a horizontal band saw machine as an example of the band saw machine according to the embodiment of the present invention.

FIG. 5 is an explanatory rear view showing an intermediate saw blade guide portion.

FIG. 6 is an operation explanatory view.

FIG. 7 is a side view of a guide portion provided on an intermediate saw blade guide according to another embodiment of the present invention.

FIG. 8 is a side view of a guide portion provided on an intermediate saw blade guide according to another embodiment of the present invention.

FIG. 9 shows a conventional example and is a front view of a general horizontal band saw machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Horizontal band sawing machine 5 Work table 13 Saw blade housing 15 Elevating cylinder 23 Band saw blade 25 Guide bar (guide member) 27 Fixed saw blade guide 27G Saw blade guide part (guide part) 29 Moving saw blade guide 29G Saw blade guide part (guide) 31) Intermediate saw blade guide 41 Saw blade guide section (guide section) 53 Fixed side insert (saw blade sandwiching member) 55 Groove section 57 Moving side insert (saw blade sandwiching member) 59 Small cylinder 63 Guide side piece 69 Coil spring ( Biasing means) 71 spring chamber 79 small cylinder 83 pressurizing chamber 85 back pressure chamber

Claims (3)

[Claims] A guide portion for guiding a band saw blade into a saw blade housing that rotatably supports a drive wheel and a driven wheel around which an endless band saw blade is wound and that is movable in a direction of cutting into a work material. A band sawing machine provided with two saw blade guides provided at a distal end portion and an intermediate saw blade guide provided at a distal end portion with a guide portion for guiding the band saw blade between the two saw blade guides; A saw blade guide is provided to be movable with respect to the saw blade housing in a direction opposite to a direction in which the band saw blade cuts the work material, and a guide portion at a distal end portion is detachable from the band saw blade. The first and second saw blade holding members for holding the band saw blade in the thickness direction, and the first and second saw blade holding members are separated from the first and second saw blade holding members again. Between the second saw blade holding members Band saw characterized by comprising providing a freely opening and closing movement means closing the second saw blade clamping member at least the first saw blade clamping member so as to input and pinching. 2. The reciprocating fluid pressure cylinder for moving the first saw blade holding member toward the second saw blade holding member on the side of the first saw blade holding member. The band saw machine according to claim 1, wherein: 3. A fluid pressure cylinder in which the opening / closing movement means moves the first saw blade holding member forward or backward toward the first saw blade holding member toward the second saw blade holding member. The band sawing machine according to claim 1, further comprising: urging means for pressing the first saw blade holding member against a forward or backward direction.