JPH09301580A - Slitter for wall trimming material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slitter for wall trimming material, in which changing work for rotary blade can be easily performed in a short time. SOLUTION: A shaft 5a penetrates and holds an under cutter 3, and its one end is screwed to a drive shaft 10c. The other end is connected to a guide roller 6 through a spacer 6b so as to be rotated together with the spacer 6b and so as to be freely moved in the axial direction of the shaft 5a. An E ring 6a is mounted on the spacer 6b so as to restrict the axial movement. A screw connected to the drive shaft 10c is removed, the shaft 5a or the drive shaft 10c can be axially moved, and a space in which insertion and remove of the under cutter 3 can be performed is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a wallpaper sizing machine for transporting a sheet-shaped wall covering material such as wallpaper while continuously applying a glue to the back surface of the wall covering material. The present invention relates to a slitter for wall covering that cuts the ear of the covering.

[0002]

2. Description of the Related Art FIG. 5 is a schematic diagram of a sizing machine slitter 1 which is mounted on a conventional general wallpaper sizing machine.
As shown in FIG. 5, the slitter 1 mainly includes an over cutter (upper blade) 2, an under cutter (lower blade) 3, a short shaft 4, a long shaft 5, a guide roll 6 and a spring stopper 7. .

The overcutter 2 is formed in a circular shape, and is slidably supported on short shafts 4 mounted separately on the left and right above both ends of the slitter 1. The overcutter 2 is fixed on the short shaft 4 by tightening a set screw (set bolt) 2b attached to a boss 2a provided on the overcutter 2.

The short shaft 4 is the overcutter 2
While slidably supporting the short shaft, one end thereof is fixed inside a front side plate (hereinafter referred to as “overstay”) 12 made of aluminum or the like of the slitter 1, and a bracket for a short shaft (hereinafter, "SS bracket"
Say. ) 14 is rotatably supported, the other end is housed in the gear box 10, and the slitter 1 moves in the direction (arrow Y direction) orthogonal to the wall-equipped material conveying direction (arrow X direction) described later. It is attached above both ends. In addition,
In the gear box 10, a gear included in the long shaft 5 and a gear included in the short shaft 4 described later are housed in a meshed state.

The undercutter 3 is formed in a circular shape, is screwed to the cutter set boss 8 and is fixed to the cutter set boss 8. The undercutter 3 is in contact with the other end of the spring 9 held by the spring stopper 7 via the cutter set boss 8 and is always urged toward the overcutter 2 by the elastic force of the spring 9. ing.

The undercutter 3, the spring stopper 7 and the coil 9 are slidably supported on the long shaft 5, and the undercutter 3 is fixed by tightening a set bolt 7a attached to the spring stopper 7. The spring stopper 7 and the coil 9 are each fixed on the long shaft 5.

Both ends of the long shaft 5 are housed in the gear box 10, and the long shaft 5 is arranged in parallel with the short shaft 4 over both lower ends of the slitter 1.
A long shaft bracket (hereinafter referred to as "LS bracket") fixed inside a rear side plate (hereinafter referred to as "center stay") 13 made of aluminum or the like 1
It is rotatably supported by 5. The short shaft 4, the spring stopper 7, the spring 9, and a guide roll 6 for smoothly feeding the conveyed wall covering material into the main body of the gluing machine described later are pivotally supported.

The slitter 1 has an oversteer-1
Scales (scale plates) 16 are attached at positions corresponding to the overcutters 2 on the outer surfaces of both ends of 2.
In addition, on the inner surface of the oversteer 12, in order to prevent the conveyed wall covering material from bending on the guide roll 6, a tension that presses the wall covering material on the guide roll 6 and that can be opened and closed up and down. A board (not shown) is attached.

A hook 17 is provided on the outer surface of the center stay 13 so that the slitter 1 can be easily attached to or removed from the main body of the gluing machine. A power transmission gear 18 for transmitting the driving force of the gluing machine and driving the slitter 1 when the hook 17 is locked on the back side of the gluing machine is provided on the rear side of one gear box 10. ing.

FIG. 6 shows a sizing machine 2 to which a slitter 1 is attached.
0 is a schematic configuration diagram on the rear surface side of FIG. 0, and FIG. 7 is an explanatory diagram showing a configuration from the side of the gluing machine to which the slitter 1 of FIG. As shown in FIGS. 6 and 7, the gluing machine 20 is
Mainly, the main body portion 21, the glue tub 22 for holding the glue, the plurality of rolls 23 to 29, the control box 30, and the leg portion 3
1 is comprised.

The main body 21 is an upper structure 21a that can be opened and closed.
And the lower body 21b, and the main body 2
The rear side of 1 is connected by a hinge. This upper structure 2
A ladle 22 and a plurality of rolls 23 to 29 are incorporated in the la or the lower structure 21b. The slitter 1 includes a plurality of rolls 23 to 23 on the rear surface side of the lower structure 21b.
It is attached by locking the hook 17 of the slitter 1 to a metal station (not shown) fixed in parallel with 29.

The leg portion 31 supports the main body portion 21 at a predetermined height and allows the cross core rod 33a of the wall covering material (cross) 33 wound in a roll shape around the cross core rod 33a to rotate. The cross receiving bracket 32 for supporting the leg portion 3
1 is provided on the rear surface side.

The control box 30 has a drive motor and a control device (not shown) inside, an operation panel 30a on the outside, and is detachably attached to one side of the main body 21. The drive motor meshes with a gear attached to a shaft end of a required roll of the plurality of rolls 23 to 29, and drives the rolls so that the rolls interlock with each other at a predetermined peripheral speed ratio. The drive operation of the drive motor is controlled by the control device. A control information signal including an operation command and an operation condition is given to the control device by operating an operation panel 30a installed in the control box 30.

In order to assemble the plurality of rolls 23 to 29, the cloth 33 is attached to the main body 2 in the upper structure 21a.
1. An upper pinch roll 27a to be taken in and a press roll 2 that presses the conveyed cloth from above and rotates following it.
8 and a drive roll 26 for applying a feeding tension to the cloth 33 are arranged in parallel in a state in which gears attached to predetermined shaft ends mesh with each other, and the upper structure 21a
Bearings are directly or via a solid lubricating ring (not shown) formed in a frame side plate made of aluminum or the like.

In the lower structure 21b, the upper pinch roll 27a is arranged to face the upper pinch roll 27a, sandwich the cloth 33, and take the cloth 33 into the main body 21.
A relatively large weight gluing roll 23 for applying glue on the back surface of the cloth to be conveyed, a doctor roll 24 for adjusting the amount of gluing to the gluing roll 23, and a cloth 21 located downstream of the gluing roll 23. The leveling roll 25 for leveling the glue applied to the glue and the glue raising roll that rotates in conjunction with the glue roll 24 in a state of being partially immersed in the glue in the glue tub 22 to lift the glue to the glue roll 24 29 and 29 are arranged in parallel in a state in which gears attached to predetermined shaft ends are meshed with each other, and are directly or in solid lubrication rings (not shown) in holes formed in the frame side plate of the lower structure 21b made of aluminum or the like. ) Is bearing.

In addition, in the pasting work, the operator first cuts the tab of the extra width dimension in order to make the width of the cloth 33 (width in the direction orthogonal to the conveying direction of the cloth) a desired width dimension. While watching the scale plate 16,
The over cutter 2 is moved on the short shaft 4 and the under cutter 3 is moved on the long shaft 5 to set a desired cross width.

In order to set the over cutter 2 and the under cutter 3 to desired cross widths, a set bolt fastened to the boss 2a of the over cutter 2 fixing the over cutter 2 on the short shaft 4. 2b is loosened and the undercutter 3 is attached to the long shaft 5
By loosening the set bolt 7a tightened to the spring stopper 7 fixed above, the over cutter 2 and the under cutter 3 are moved to desired positions, and the set bolts 2b and 7a are tightened again to remove the over cutter. 2 and the undercutter 3 are fixed.

After that, the operator lifts the upper structure 21a upward to open the main body 21 and sets the operation panel 30a of the control box 30 in order to initialize the glue.
Is operated to drive the motor, and the plurality of rolls 23 to 29 and the overcutter 2, the undercutter 3, and the guide roll 6 arranged in the slitter 1 are rotationally driven in accordance with the drive of the motor.

The over-cutter 2, the under-cutter 3 and the guide roll 6 disposed in the slitter 1 are engaged with a gear mounted on the shaft end of a required roll of the plurality of rolls 23 to 29. It is adapted to be rotationally driven via the transmission gear 18.

Then, pull out the tip of the cloth 33,
The tip of the cloth 33 is passed through the gap between the overcutter 2 and the undercutter 3 which are rotating, and the excess cloth is cut off and dropped on the front side of the gluing machine main body 21 to stop the driving of the motor. Then, the upper structure 21a is closed.

After that, the operator further cuts the tip portion of the cloth 33 which is not glued along the cutter guide 34 arranged in the lower structure 21b, and completes the glueing initial setting.

After the gluing initialization is completed, the operator
A desired cross length is input from the operation panel 30a, and a plurality of rolls 23 to 2 are connected by gears by driving a motor.
9 and the overcutter 2, the undercutter 3, and the guide roll 6 rotate at a predetermined peripheral speed ratio so as to have a desired cross width.
While being transported inside, the glue tub 22 is moved by the glue raising roll 29.
The glue inside is applied to the gluing roll 23, and the gluing roll 2
The glue applied to No. 3 is adjusted by the doctor roll 24, and the glue on the surface of the gluing roll 23 is applied to the back surface of the conveyed cloth 33 under the effect of the pressing roll 28.

The glued cloth 33 is then pulled by the drive roll 26 and the leveling roll 25 while being given a proper tension, and sent out to the front surface of the main body 21. At this time, the leveling action of the glue surface is given by the peripheral speed difference of the leveling roll 25. Then, when the desired cross length appears on the front surface, the driving of the motor is temporarily stopped, the cloth 33 is cut along the cutter guide 34 with a cutter, and the cloth 33 is accumulated on the tray 35 provided on the front surface of the main body 21. Then, the glued cloth 33 is folded. The worker repeats this work.

In this way, the conventional wallpaper sizing machine slitter 1 is attached to the rear surface side of the sizing machine main body 21 and is set to set the over cutter 2 and the under cutter 3 to a desired cross width dimension. By operating the bolts 2b and 7a, the short shaft 4 and the long shaft 5 are slidably moved and positioned, and the ears of the conveyed cloth 33 are cut.

The conventional slitter for wallpaper gluing machine is
The slitter is not limited to the slitter that is driven in conjunction with the gluing machine, and has a slitter-specific drive motor that rotationally drives the overcutter 2 and the undercutter 3 to cut the ears of the conveyed cloth 33. There is also one.

[0026]

The over-cutter 2 and the under-cutter 3 gradually deteriorate in sharpness as they are used for a long period of time, and in some cases a good cut surface cannot be obtained. In addition, the sharpness is deteriorated even if the idling operation is performed in which the device is not mounted with the wall covering, or the blade tip is broken by hitting a hard object on the over cutter 2 and the under cutter 3. In such a case, it is necessary to replace the over cutter 2 or the under cutter 3 with a new sharp one.

Replacement of the cutter in the conventional apparatus will be described with reference to FIG. FIG. 4 is a schematic diagram when FIG. 5 is viewed from above. In the case of the overcutter 2, the screw for fixing to the short shaft 4 is loosened and the overcutter 2 is slid to the SS bracket 14 side. After that, the SS bracket 14 is removed and the short stay 4
Further, by removing from the SS bracket 14, the overcutter 2 can be removed and a new one can be inserted.

When replacing the undercutter 3, after removing the bearing cover covering the periphery of the gear box 10,
Remove the undercutter gear 10b from the long shaft 5. Moreover, since the long shaft 5 penetrates the entire inside of the slitter 1, it is necessary to remove the bearing cover and the undercutter gear on the side opposite to the side to be replaced as well. Then, the E-ring 6a for restraining the axial movement of the long shaft 5 is removed, and the long shaft 5 is further axially moved to the opposite side to the side where the long shaft 5 is replaced, to secure a space for removing the under cutter 3. This makes it possible to replace the undercutter 3 for the first time.

As described above, in the replacement work, apart from the overcutter 3, when the undercutter 4 is replaced, it is necessary to remove the bearing cover and the gear which do not need to be replaced. Since the work also extends to the opposite side of the undercutter, the work content is extremely complicated and the work time becomes long.

The present invention has been made in order to solve the above problems, and an object of the present invention is to obtain a slitter for wall coverings which can easily replace an overcutter or an undercutter in a short time. To do.

[0031]

According to the invention as set forth in claim 1, an end portion of the sheet-shaped wall covering material is constituted by a pair of upper and lower rotary blade members arranged near the end portion of the conveyed sheet-like wall covering material. In a slitter for wall covering material that cuts, a shaft member that penetrates and holds the center of the rotary blade member, a bearing portion that holds an end portion side of the shaft member, and the bearing portion of the shaft member sandwiched therebetween. A drive gear member provided on the opposite side of the rotary blade member, and the shaft member is detachably connected to a drive unit including the drive gear member, and the connection with the drive unit is released. In the opened state, there is provided a blade exchange space forming means for forming a space in which the rotary blade member can be inserted and removed between the tip of the shaft member and the inside of the bearing portion.

That is, after the connection with the drive unit is released,
The rotary blade member is inserted into and removed from the shaft member by utilizing the space formed between the tip of the shaft member and the inside of the bearing portion by the blade replacement space forming means, and the rotary blade member can be replaced. become.

The blade replacement space forming means may be, for example, a means for moving the shaft member side in the axial direction or a means for moving the driving portion side in the axial direction, as long as the moving amount is equal to or larger than the thickness of the rotary blade member. The rotary blade member can be inserted and removed as it is. Further, this means may form a space by removing a part of the shaft member instead of forming a space by moving in the axial direction. Even in this case, the space formed by the removal is the rotary blade member. More than the thickness of
The rotary blade member can be inserted and removed as it is. Further, a combination of these, that is, a combination of the one by moving and the one by removing may be combined to form a space for exchanging the rotary blade. In any case, with the shaft member and the drive unit disconnected,
It is preferable that the bearing cover and the gear are not individually removed.

The connecting position of the shaft member and the drive portion including the drive gear member may be on the rotary blade member side or the drive gear member side of the bearing portion, but in the former case, the drive portion is removed from the bearing portion. There is no need, and replacement work becomes easier. In the latter case, it is preferable that the connection can be released without removing the bearing cover.

The shaft member may be an integral type in which one shaft penetrates the entire slitter for wall covering, but two pairs of upper and lower rotary blade members are provided at both ends of the sheet-like wall covering. In the case of the wall-mounting material slitters located near each other, the shaft member can be composed of two shafts arranged coaxially, and in addition, the two shafts can be separated to some extent in the axial direction. It is also possible to dispose them so that they are open and allow movement in the axial direction. In this case, if the amount of movement of the shaft is equal to or greater than the thickness of the rotary blade member, workability is further improved.

In the invention described in claim 2, claim 1
In the wall-mounting material slitter described in (1), the blade-replacement space forming means is configured such that the shaft member is axially movable to such an extent that the space can be formed.

That is, which is one of the modes of the blade-replacement space forming means, the space in which the rotary blade member can be inserted and removed is formed by the shaft member moving in the axial direction. Therefore, this movement amount must be at least larger than the thickness of the rotary blade to be replaced. In addition, depending on the structure of the slitter, the cover of the drive unit may be an obstacle when moving in the axial direction, and in this case, the cover is configured to be removable. Also in this invention, the rotating blade can be easily replaced.

According to the invention described in claim 3, claim 1
In the wall-mounting material slitter described in (1), the drive portion has a drive shaft portion that interlocks with the drive gear member, the shaft member is connected to the drive shaft portion, and the connection position is the bearing Is formed on the rotary blade member side with respect to a portion, and in the blade replacement space forming means, at least one of the shaft member and the drive portion is configured to be movable in the axial direction. .

Since the connecting position between the shaft member and the drive shaft portion is formed on the rotary blade member side (inner side) with respect to the bearing portion, it is necessary to remove the cover of the drive portion at the time of the work of releasing this connection. Absent.

The blade-replacement space forming means is based on the movement in the axial direction, and the object to be moved may be either the shaft member or the drive shaft portion. However, when the tip of the shaft member is formed closer to the rotary blade member than the bearing, if the shaft member is moved, the drive unit including the drive shaft does not need to be removed and is held by the bearing unit. Since the work can be performed in this state, the assembly after replacement can be easily performed.

In the invention described in claim 4, claim 1
In the slitter for wall covering material according to the above item, the rotary blade member has two sets of rotary blade members arranged so as to be located near both ends of the sheet-like wall covering material, and the shaft member is It has two shaft members for holding each of the rotary blade members at both ends, further comprising a holding means for holding the two shaft members coaxially with a predetermined interval in the substantially central portion, The blade replacement space forming means is characterized in that the holding means is configured to allow the axial movement of the respective shaft members.

That is, two pairs of upper and lower rotary blade members are used to cut both ends of the sheet-shaped wall covering material.
Further, since the number of shaft members arranged coaxially is two, one rotary blade member is penetratingly held by one shaft member. These shaft members are spaced at a predetermined distance, and are allowed to move in the axial direction,
It is held by holding means.

As described above, since the shaft members can be separately moved in the axial direction, the replacement work can be further facilitated.

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A shows one of the embodiments of the present invention and shows the mechanism of the undercutter part. Since it is simpler than that, it may be performed according to FIG.

Under cutter 3 which is a lower rotary blade member
Are screwed to the cutter set boss 8. A spring stopper 7 is fixed to the shaft 5a, which is the first shaft member for the lower rotary blade member, and the undercutter 3 is held by the shaft 5a with a coil 9 interposed. The shaft 5a is formed and arranged so that its outer tip is located inside the bearing plate 10a of the bearing portion, but the tip may be located outside the bearing plate 10a. In this embodiment, the shaft member for the lower rotary blade is coaxially composed of two shaft members, and this figure shows one of the shaft members. The opposite side is symmetrical with this figure.

The shaft 5a is screwed so as to be coaxial with the drive shaft 10c which is the drive shaft portion of the drive portion.
It is connected with 0d. Therefore, when the screw 10d is removed, the connection between the shaft 5a and the drive shaft 10c (drive unit) is released. The position of the screw 10d is inside the bearing plate 10a in the present embodiment, but may be outside. The drive shaft 10c
Both ends are held by a bearing plate 10a and a cover 10e, and are connected to a drive unit (not shown) via an undercutter gear 10b, and the rotational force from the drive unit is transmitted to the shaft 5a. .

When the drive shaft 10c is moved axially outward with the drive shaft 10c and the shaft 5a disconnected from each other, a space d in which the undercutter 3 can be inserted and removed.
Since the space is formed, the lower rotary blade 3 can be replaced by using this space d. This state is shown in FIG. In consideration of workability at the time of replacement, the gear box 10 is covered with the cover 10e, and the under cutter gear 10b is difficult to remove and difficult to assemble. It is preferable to move the side inward in the axial direction.

The other end on the center side of the shaft 5a is rotatably held by a guide roll 6, a spacer 6b, and an E ring 6a as holding means. That is, the spacer 6b is inserted in the guide roll 6, and the movement thereof is restricted in the axial direction by the E ring 6a. The shaft 5a rotates integrally with the spacer 6b in the circumferential direction while being movable in the restraint axis direction while the spacer 6b moves.
Has been inserted. This state is shown in FIG. FIG. 2 shows a sectional view taken along the line AA of FIG. A key groove is provided so as to be integrated with the spacer 6b when rotating.

Further, the shaft 5a is provided with a limiting means for limiting the movement in the axial direction during use. This is to ensure stable operation during operation. In the present embodiment, specifically, the drive shaft 10 via the screw 10d is used.
The axial connection is restricted by the screw connection with c.

Therefore, by removing the above-mentioned screw 10d, the shaft 5a can be moved in the axial direction,
As a result, a space d'where the undercutter 3 can be inserted and removed is created. This state is shown in FIG.

The structure on the opposite side (not shown) may be arranged in the opposite direction to the structure of this embodiment. In this case, the guide roll 6 may be arranged substantially at the center, and the two shafts 5a may be arranged coaxially with a distance larger than the thickness of the undercutter 3 to be inserted and removed. Thereby, the workability can be further improved.

In this embodiment, the guide roller constitutes the holding means for the shaft member of the lower rotary blade. That is, since the inside of the guide roller itself may be a simple space, the space is used as a holding means for the two shafts. It should be noted that the space between the two shafts inside may be such that a space sufficient for replacing the lower blade can be formed.

Next, another embodiment is shown in FIG. In this embodiment, a connecting member 5b that connects the tip of the shaft 5a and the drive unit is provided. In the present embodiment, by loosening the screws 5c and 10b and removing the connecting member 5b, a space d ″ in which the undercutter 3 can be inserted and removed.
Is formed. When this connecting member is used, a means for moving the shaft or the drive unit is not particularly necessary. Further, there is an advantage that the lower blade can be easily replaced even if one long shaft that holds the left and right rotary blades is used.

[0054]

According to the invention described in claim 1, the number of parts required for the replacement work of the rotary blade is reduced, and the work can be easily performed.

According to the invention described in claim 2, since the structure that moves in the axial direction is adopted, the workability can be further improved.

According to the invention described in claim 3, since the connecting position of the shaft member and the drive shaft is inside the bearing portion, the disassembling and assembling work is facilitated and the rotary blade is easily replaced. Can be done.

According to the invention described in claim 4, since the shaft member is divided into two, the rotary blade can be removed and attached very easily and in a short time.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a main part of a slitter for wall covering material according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a partial cross-sectional view (A-A cross-sectional view) of a slitter for wall covering material according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a main part configuration of a slitter for wall covering material according to another embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a configuration of a main part of a conventional slitter for wall covering material.

FIG. 5 is an explanatory view showing a schematic configuration of a conventional slitter for wall covering material.

FIG. 6 is a schematic configuration view seen from the rear surface side of a gluing machine to which a conventional slitter for wall covering is attached.

FIG. 7 is a schematic configuration view of a conventional gluing machine to which a slitter for a wall covering material is attached as seen from a side.

[Explanation of symbols]

 3 ・ ・ Under cutter 5a ・ ・ ・ ・ ・ Shaft 6 ・ ・ ・ ・ ・ ・ Guide roll 6a ・ ・ ・ E-ring 7 ・ ・ ・ ・ Spring stopper 8 ・ ・ ・ ・ Cutter Set boss 9 ... ・ Coil 10a ・ ・ ・ ・ Bearing plate 10b ・ ・ ・ ・ Under cutter gear 10c ・ ・ ・ ・ Drive shaft 10d ・ ・ ・ ・ Screw 10e ・ ・ ・ ・ Cover

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Ikeshima 70 Honjo, Fukuoka Town, Nishitonami-gun, Toyama Prefecture Yayoi Chemical Industry Co., Ltd.

Claims (4)

[Claims] 1. A wall mounting material slitter for cutting an end portion of a sheet-shaped wall covering material by a pair of upper and lower rotating blade members arranged in the vicinity of an end portion of a sheet-shaped wall covering material to be conveyed, wherein the rotating blade member. A shaft member that penetrates through the center of the shaft member, a bearing portion that holds the end portion side of the shaft member, and a drive gear member that is provided on the opposite side of the rotary blade member with the bearing portion of the shaft member interposed therebetween. The shaft member is detachably connected to a drive unit including the drive gear member, and in a state where the connection with the drive unit is released, a tip of the shaft member and the bearing unit are A slitter for wall covering, comprising a blade exchange space forming means for forming a space into and from which the rotary blade member can be inserted and removed. 2. The wall mounting material according to claim 1, wherein the blade-replacement space forming means is configured such that the shaft member is axially movable to such an extent that the space can be formed. Slitter. 3. The drive unit has a drive shaft unit that is interlocked with the drive gear member, the shaft member is connected to the drive shaft unit, and the connecting position of the drive member is greater than that of the bearing unit. The blade forming member is formed on the blade member side, and at least one of the shaft member and the driving unit is configured to be axially movable in the blade replacing space forming unit. Slitter for wall covering. 4. The rotary blade member has two sets of rotary blade members arranged so as to be located near both ends of the sheet-shaped wall covering, respectively, and the shaft member has rotary blades at both ends thereof. A blade exchange space forming means further comprising two shaft members for holding each of the members, and a holding means for coaxially holding the two shaft members at a predetermined interval in a substantially central portion. The wall mounting material slitter according to claim 1, wherein the holding means is configured to allow movement of the respective shaft members in the axial direction.