JP2986676B2 - Blade polishing device with blade edge adjustment function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a blade polishing apparatus having a blade edge adjusting function, and more particularly to an adjustment of a blade edge position when a blade edge of a blade is polished in parallel to a peak.

[0002]

2. Description of the Related Art FIG. 7 shows the overall structure of a conventional blade polishing apparatus. The table 2 is provided on the bed 30. The table 2 can be reciprocated on the bed 30 in the directions of arrows 90 and 91 by forward and reverse rotation of a feed motor. A tool post 6 is fixed on the table 2, and the tool is attached to the tool post 6.

[0003] Above the tool post 6, a rough grindstone 11K and a finishing grindstone 12K are located. The rough grindstone 11K and the finishing grindstone 12K are rotated by the rough grindstone rotating motor 11 and the finishing grindstone rotating motor 12, respectively, and grind the blade fixed to the tool rest 6. The roughing wheel rotation motor 11 and the finishing wheel rotation motor 12 are moved up and down in the directions of arrows 92 and 93 by the wheel lifting motors, respectively.

In the case of polishing a blade, first, the rough grinding wheel rotating motor 11 is driven to rotate the rough grinding wheel 11K, and then the rough grinding wheel rotating motor 11 is lowered in the direction of arrow 93 to bring the rough grinding wheel 11K into contact with the blade. . Then, the feed motor is rotated forward and backward, and reciprocating movement of the table 2 in the directions of arrows 90 and 91 is repeated. As the table 2 reciprocates, the blade is polished over its entire length.

[0005] When the polishing by the rough grindstone 11K is completed, the rough grindstone 11K is raised in the direction of arrow 92, and then the finishing grindstone rotating motor 12 and the finishing grindstone 12K are lowered in the direction of arrow 93. Thereafter, while the table 2 is similarly reciprocated, polishing by the finishing whetstone 12K is performed.

Thus, the arrows 90 and 91 of the table 2
Since the blade is polished as it reciprocates in the direction,
The trajectory line of the tool rest 6 reciprocating with respect to the grindstone is formed as a polishing line. FIG. 8A is a plan view of the tool rest 6. A polishing line L1 is formed along the directions of the arrows 90 and 91, and the cutting edge of the blade is polished along the polishing line L1.

FIGS. 6A and 6B show a blade 10 to be polished. As a knife used for automatic canning machines, etc.,
As shown in FIG. 6B, the cutting edge 10F of the blade 10 and the peak 10
B substantially parallel to each other is used. For this reason, for example, as shown in FIG. 6A, when the blade 10F and the peak 10B are not parallel to each other, when the blade 10 is fixed to the tool rest 6, the polishing line L1 and the peak 10B are positioned in parallel.
Polishing must be performed. Polishing line L1 and peak 10B
Are positioned in parallel, so that the cutting edge 1 to be polished is
OF can be finished in parallel with the peak 10B.

The details of the work of attaching and fixing the blade 10 to the tool post 6 will be described. 8A is a plan view of the tool rest 6, FIG. 8B is a front view, and FIG. 8C is a side view. First, the operator loosens the holding bolt 31 and releases the fixing of the holding plate 32 and each of the fixing plates 33, and then inserts the blade 10 between the fixing plate 33 and the tool rest 6. Then, the protruding length of the cutting edge 10F from the tool post 6 is adjusted.

The adjustment of the protruding length of the cutting edge 10F is described in FIG.
This is performed using a blade set gauge 55 shown in FIG. The mounting surface 55M of the tool set gauge 55 is a magnet, and the mounting surface 55M is attached to the side surface of the tool post 6. The blade set gauge 55 includes a plurality of step-down portions 5.
5G is formed. Then, the stepped portion 55G is selected according to the required protruding length of the cutting edge 10F, and the protruding length is adjusted by bringing the cutting edge 10F into contact with the stepped down portion 55G.

After adjusting the protruding length of the cutting edge 10F in this way, in order to finish the cutting edge 10F in parallel with the peak portion 10B, the polishing line L1 and the peak portion 10B are positioned in parallel. The position of the ridge 10B is adjusted by adjusting a plurality of adjustment screws 50.
This is performed using Each adjusting screw 50 is screwed into and penetrates the screw hole 6W of the tool rest 6 (FIG. 8C).

When the adjusting screw 50 is tightened, the adjusting screw 50 advances in the direction of the arrow 94, and the tip portion 50T comes into contact with the ridge portion 10B to partially press the cutting tool 10. By sequentially performing such tightening work for the plurality of adjustment screws 50, the parallel positional relationship between the polishing line L1 and the peak portion 10B can be controlled. In this case, the operator performs the adjustment while checking the parallelism between the polishing line L1 and the peak 10B by visual measurement. After such parallel adjustment of the ridge 10B, the holding bolt 31 is tightened to fix the position of the blade 10.

[0012]

The following problems have been encountered in adjusting the cutting edge of a conventional blade polishing apparatus. Conventionally, in order to finish the cutting edge 10F in parallel with the ridge 10B, a plurality of adjusting screws 50 are conventionally tightened, and the ridge 10B is connected to the polishing line L1.
It is adjusted by eye measurement so that it is almost parallel to. For this reason, there is a problem that the operation of positioning the polishing line L1 and the peak portion 10B in parallel is not easy, and it is difficult to accurately adjust the position.

When adjusting the length of protrusion of the cutting edge 10F using the blade set gauge 55 (FIG. 8C), the blade 10
Is required to be inserted deeply in the direction of the arrow 95, so that the plurality of adjustment screws 50 must be sufficiently retracted in the direction of the arrow 95. After the blade 10 is inserted, the adjusting screw 50 is advanced in the direction of the arrow 94, and the blade 10F is brought into contact with the stepped-down portion 55G of the blade set gauge 55 as described above to adjust the protruding length of the blade 10F.

Here, in order to advance or retreat the adjusting screw 50 in the directions of arrows 94 and 95, the adjusting screw 50 must be rotated and tightened or loosened. Therefore, the cutting edge 1
At the time of adjusting the projecting length of 0F, there is a problem that it takes time and effort to move the adjusting screw 50 forward and backward greatly, and the work efficiency is reduced. When the object to be polished is replaced with a new blade 10 and set on the tool rest 6, the ridge 10B is moved from the blade edge 10F.
If the width up to is significantly different from the previous blade, the adjustment screw 50
Also increase the amount of retreat. In this case as well, there is a problem that the working efficiency is reduced.

Therefore, the present invention makes it possible to easily and surely polish the cutting edge by positioning the cutting edge of the cutting tool substantially parallel to the ridge.
Moreover, it is an object of the present invention to provide a blade polishing apparatus having a blade edge adjusting function capable of avoiding a decrease in work efficiency.

[0016]

According to a first aspect of the present invention, there is provided a blade polishing apparatus having a blade edge adjusting function, comprising: a blade fixing portion to which the blade is mounted; and a blade edge of the blade mounted to the blade fixing portion.
A polishing section for polishing along a predetermined polishing line, an adjustment plate having a contact surface that comes into contact with a ridge of a blade, wherein the contact surface is positioned substantially parallel to the polishing line, and the contact surface and the polishing line And an adjustment plate slidably attached to the blade fixing portion so as to move while maintaining the parallel state, and a fixture for fixing the position of the adjustment plate in the blade fixing portion.

According to a second aspect of the present invention, there is provided a blade polishing apparatus having a blade edge adjusting function according to the first aspect of the present invention, wherein scales for parallel movement are formed at two or more locations of the blade fixing portion. The two or more parallel movement scales are respectively associated substantially parallel to the polishing line, and indicate a reference for parallel movement of the adjustment plate with respect to the polishing line.

According to a third aspect of the present invention, there is provided a blade polishing apparatus having a blade edge adjusting function, wherein the adjusting plate is detachably attached to a blade fixing portion. , Is characterized.

[0019]

According to the first aspect of the present invention, there is provided a blade polishing apparatus having a blade edge adjusting function, wherein an adjusting plate having a contact surface that comes into contact with a ridge of the blade is provided, and the contact surface of the adjusting plate is substantially parallel to the polishing line. It is located in. And
The adjustment plate is slidably attached to the blade fixing portion so as to move while maintaining a parallel state between the contact surface and the polishing line. The fixture fixes the position of the adjustment plate in the blade fixing portion.

Therefore, by moving the adjusting plate in parallel and pressing the ridge of the blade with the contact surface of the adjusting plate, the ridge can be positioned substantially parallel to the polishing line. Further, since the adjustment plate is slidable with respect to the blade fixing portion, it can be easily and quickly moved. Further, since the fixing tool is provided, the adjustment plate can be fixed on the blade fixing portion with the peak of the blade positioned substantially parallel to the polishing line.

According to a second aspect of the present invention, there is provided a blade polishing apparatus having a blade edge adjusting function, wherein two or more parallel scales are formed at two or more locations of the blade fixing portion. It is associated substantially parallel to the polishing line, and indicates a reference for parallel movement of the adjustment plate with respect to the polishing line.

Therefore, by moving the adjustment plate along the parallel movement scale, the adjustment plate can be moved while reliably maintaining the parallel state with the polishing line.

In the blade polishing apparatus having a blade edge adjusting function according to the third aspect, the adjustment plate is detachably attached to the blade fixing portion.

Therefore, when the peak of the blade does not need to be positioned parallel to the polishing line, the work can be performed by removing the adjusting plate from the blade fixing portion.

[0025]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a blade polishing apparatus having a blade edge adjusting function according to the present invention. Hereinafter, first, the outline of the polishing operation of the blade polishing apparatus will be described, and then the details of the blade edge adjusting operation will be described.

[Outline of Polishing Operation] FIG. 1 is an overall front view of a polishing apparatus according to the present embodiment, and FIG. 2 is an overall side view. The bed 2 is provided with a table 2.
Is a bed 3 by forward and reverse rotation of a feed motor (not shown).
It is possible to reciprocate in the directions of arrows 90 and 91 on 0. A tool post 6 as a tool fixing portion is fixed on the table 2, and the tool is attached to the tool post 6.

FIG. 4 is a view showing the details of the tool rest 6, and FIG.
Is a plan view and B is a front view. When fixing the blade 10 to the tool rest 6, the holding bolt 31 is loosened and the holding plate 32,
After the fixing of each fixing plate 33 is released, the cutter 10 is inserted between the fixing plate 33 and the tool post 6. Then, the protrusion length of the cutting edge 10F from the tool post 6 is adjusted, and the parallel angle of the peak 10B is adjusted.

The adjustment of the protruding length of the cutting edge 10F is described in FIG.
A is performed using a blade set gauge 55 shown in FIG. FIG. 5A
Is a side view of the tool rest 6. The mounting surface 55M of the tool set gauge 55 is a magnet, and the mounting surface 55M is attached to the side surface of the tool post 6. The blade set gauge 55 has a plurality of stepped-down portions 55G. Then, the stepped portion 55G is selected according to the required protruding length of the cutting edge 10F, and the cutting edge 1G is added to the stepped portion 55G.
Adjust the protruding length by bringing 0F into contact.

At the same time as adjusting the protruding length, the cutting edge 10F
Is polished almost parallel to the peak 10B.
Is adjusted. Here, the peak portion is a portion of the back of the cutting tool 10 with respect to the cutting edge 10F. The details of the blade edge adjustment operation will be described later. After the blade edge adjustment, the holding bolt 31 is tightened to fix the blade 10 on the tool rest 6. Next, the angle adjustment handle 35 (FIG. 1) is turned to adjust the inclination angle of the tool rest 6 with respect to the grindstone in the direction of arrow 99 (FIG. 2), and the fixed handles 34 provided at both ends of the table 2 (FIG. 1). ) To fix the inclination angle.

Above the tool post 6, a rough grinding stone 11K and a finishing grinding stone 12K are located as polishing portions. The rough whetstone 11K and the finishing whetstone 12K are respectively
1. The tool rest 6 which is rotated by the finishing wheel rotating motor 12
The blade 10 fixed to is ground. Further, the roughing wheel rotation motor 11 and the finishing wheel rotation motor 12 are moved up and down in directions of arrows 92 and 93 by a wheel lifting motor (not shown), respectively.

When the blade 10 is polished, first, the rough grinding wheel rotating motor 11 is driven to rotate the rough grinding wheel 11K, and then the rough grinding wheel rotating motor 11 is lowered in the direction of arrow 93 to bring the rough grinding wheel 11K into contact with the blade 10. Let it. Then, the feed motor is rotated forward and backward, and reciprocating movement of the table 2 in the directions of arrows 90 and 91 is repeated. As the table 2 reciprocates, the blade 10 is polished over its entire length.

When the polishing by the rough grindstone 11K is completed, the rough grindstone 11K is raised in the direction of arrow 92, and then the finishing grindstone rotating motor 12 is driven to rotate the finishing grindstone 12K.
The finishing grindstone rotation motor 12 and the finishing grindstone 12K
Lower in three directions. Thereafter, while the table 2 is similarly reciprocated, polishing by the finishing whetstone 12K is performed.
As described above, the blade 10 is polished by the rough grindstone 11K and the finish grindstone 12K.

[Details of Blade Edge Adjustment Operation] As described above, the blade is polished as the table 2 reciprocates in the directions of arrows 90 and 91, so that the trajectory line of the tool rest 6 that reciprocates with respect to the grindstone is adjusted. It is formed as a polishing line. That is, as shown in FIG. 4A, a polishing line L1 is formed in the directions of arrows 90 and 91, and the cutting edge 10F of the cutting tool 10 is polished along the polishing line L1.

FIGS. 6A and 6B show the blade 10 to be polished. As a knife used for automatic canning machines, etc.,
As shown in FIG. 6B, the cutting edge 10F of the blade 10 and the peak 10
B substantially parallel to each other is used. There is a blade 10 to be polished, for example, as shown in FIG. 6A, in which the blade edge 10F and the peak 10B are not parallel. For this reason, when the blade 10 is fixed to the tool post 6, it is necessary to perform polishing by positioning the polishing line L1 and the peak 10B in parallel. By positioning the polishing line L1 and the peak 10B in parallel, the blade edge 10F to be polished can be finished in parallel with the peak 10B.

The adjustment of the parallel position of the ridge 10B with respect to the polishing line L1 and the adjustment of the protruding length of the cutting edge 10F are performed using the adjustment plate 4. The adjustment plate 4 is attached to the tool post 6 as shown in FIG.
It is slidable in 4,95 directions. FIG. 3 shows details of the adjustment plate 4. 3A is a plan view, and FIG. 3B is a front view. The adjustment plate 4 has two arm sections 40 at both ends of the main body section 42. As shown in FIG. 3A, the two arm portions 40 are located at substantially 90 degrees with respect to the main body portion 42. Further, as shown in FIG. 3B, an upright wall 40K is formed outside the arm portion 40 by bending, and a portion excluding the upright wall 40K is formed as an insertion surface 43.

On the other hand, insertion grooves 6G are formed at both ends of the tool rest 6, as shown in FIG. 4B, and the insertion surfaces 43 of the adjustment plates 4 are inserted into the respective insertion grooves 6G. As the insertion surface 43 slides along the insertion groove 6G of the tool rest 6, the adjustment plate 4 slides in the directions of arrows 94 and 95. With the insertion surface 43 of the adjustment plate 4 inserted into the insertion groove 6G, the contact surface 4M of the adjustment plate 4 (FIG. 3)
A) is located substantially parallel to the polishing line L1. In addition, the contact surface 4M is located so as to be able to contact the peak 10B of the blade 10.

As described above, the tool 1 is attached to the tool rest 6.
When fixing 0, the holding bolt 31 is loosened, and the blade 10 is inserted between the fixing plate 33 and the tool post 6. In this case, the adjustment plate 4 is sufficiently retracted in the direction of the arrow 95,
The knife 10 is once inserted deeply. Thereafter, the tool set gauge 55 shown in FIG. 5A is attached to the side surface of the tool post 6. In this state, the operator moves the adjustment plate 4 in the direction of the arrow 94, and presses the ridge 10B of the blade 10 with the entire contact surface 4M. Upon receiving this pressure, the blade 10 also advances in the direction of arrow 94.

Here, in the adjustment plate 4, since the insertion surfaces 43 located at both ends slide along the insertion grooves 6G of the tool post 6, the parallel state of the contact surface 4M and the polishing line L1 is maintained. That is, the blade 10 that moves by receiving the pressure of the contact surface 4M also moves in the direction of the arrow 94 with the peak portion 10B kept parallel to the polishing line L1. As described above, since the peak 10B can be positioned substantially parallel to the polishing line L1, the cutting edge 10F polished along the polishing line L1 can be finished almost parallel to the peak 10B.

As shown in FIG. 4A, scale portions 7a and 7b as scales for parallel movement are formed at both ends of the tool rest 6. The graduations in the graduations 7a, 7b are associated with the polishing line L1 almost in parallel, and the adjustment plate 4
Is a reference for the parallel movement. Since the scale portions 7a and 7b are formed, the adjustment plate 4 can be moved while reliably maintaining the parallel state, and the protrusion length of the cutting edge 10F can be accurately adjusted. The scale for parallel movement in the present invention is not limited to the scale portions 7a and 7b, and may employ another configuration as long as the scale is substantially parallel to the polishing line and indicates a reference for parallel movement of the adjustment plate. May be.

As described above, the blade 10 is moved in the direction of the arrow 94, and the blade tip 10F is brought into contact with the step 55G of the blade set gauge 55 (see FIG. 5A). Then, in this state, the holding bolt 31 is tightened and the blade 10 is moved to the tool rest 6.
Fix on top. Since the adjustment plate 4 can be slid and moved in the directions of the arrows 94 and 95, the adjustment plate 4 can be easily and quickly moved, and a decrease in work efficiency can be avoided.

Subsequently, fixing bolts 8 as fixing tools provided at both ends of the tool post 6 are tightened, and the adjusting plate 4
Fix the position of. FIG. 5B is an enlarged view of the vicinity of the fixing bolt 8.
Shown in The fixing bolt 8 is screwed into the end piece 6N of the tool post 6,
It penetrates so that the bolt tip 8T protrudes toward the insertion groove 6G.

By tightening the fixing bolt 8, the bolt tip 8T presses the insertion surface 43 of the adjustment plate 4 in the direction of arrow 93. The tightening of the fixing bolts 8 is performed on both ends of the tool post 6, and the positions are fixed by pressing the insertion surfaces 43 on both sides of the adjustment plate 4 (see FIG. 4).

Since the position of the adjusting plate 4 is fixed by using the fixing bolt 8, the position of the adjusting plate 4 during the operation can be stabilized. For example, even if the tool rest 6 is tilted in the direction of arrow 99 (FIG. 2) with respect to the grindstone by turning the angle adjusting handle 35 (FIG. 1), the adjusting plate 4 does not move.

After the polishing operation is completed, the holding bolt 31 is loosened while the tool rest 6 is inclined, and the blade 10 is cut.
May be released. Even in such a case, since the position of the adjustment plate 4 is fixed, the blade 10 does not fall in the arrow 95 direction. When the adjustment plate 4 is moved, the fixing bolt 8 is loosened and the pressurization by the bolt tip 8T is released.

The adjustment plate 4 is detachable from the tool post 6, and can be removed when the adjustment plate 4 is unnecessary. When removing, the adjustment plate 4 is pulled out in the direction of arrow 94 (FIG. 4A), and the insertion groove 6 of the tool rest 6 is removed.
Pull out the insertion surface 43 of the adjustment plate 4 from G. In the present embodiment, as shown in FIGS.
Three hooks 30F are provided. The adjustment plate 4 is hooked on the hook 30F, and the removed adjustment plate 4 does not hinder the work.

The blade polishing apparatus having a blade edge adjusting function according to the present invention is not limited to the above embodiment. For example, the adjusting plate is not limited to the shape and structure shown in FIG. 3, and other configurations may be adopted as long as the contact surface slides while maintaining a state parallel to the polishing line. Further, the fixing device in the present invention is not limited to the fixing bolt 8,
Other mechanisms may be used as long as the position of the adjustment plate can be securely fixed.

[0047]

According to the first aspect of the present invention, there is provided a blade polishing apparatus having a blade edge adjusting function, wherein an adjusting plate having a contact surface which comes into contact with a ridge of the blade is provided. They are located almost parallel. The adjustment plate is slidably attached to the blade fixing portion so as to move while maintaining the parallel state between the contact surface and the polishing line. The fixture fixes the position of the adjustment plate in the blade fixing portion.

That is, the adjustment plate is moved in parallel,
By pressing the ridge of the blade with the contact surface of the adjustment plate, the ridge can be positioned substantially parallel to the polishing line. Therefore, it is possible to easily and surely polish the cutting edge of the blade substantially parallel to the ridge.

Further, since the adjustment plate is slidable with respect to the blade fixing portion, it can be easily and quickly moved. Therefore, it is possible to avoid the trouble of moving the adjustment plate and to reduce the work efficiency.

Further, since the fixing tool is provided, the ridge of the blade is positioned substantially parallel to the polishing line.
The adjustment plate can be fixed on the blade fixing part.
Therefore, the position of the adjustment plate on the blade fixing portion during the operation can be stabilized.

According to a second aspect of the present invention, there is provided a blade polishing apparatus having a blade edge adjusting function, wherein two or more parallel scales are formed at two or more portions of the blade fixing portion. It is associated substantially parallel to the polishing line, and indicates a reference for parallel movement of the adjustment plate with respect to the polishing line.

That is, by moving the adjustment plate along the parallel movement scale, the adjustment plate can be moved while reliably maintaining the parallel state with the polishing line. Therefore, it is possible to more reliably polish the cutting edge of the blade substantially parallel to the ridge.

In the blade polishing apparatus having the blade edge adjusting function according to the third aspect, the adjustment plate is detachably attached to the blade fixing portion.

Therefore, when it is not necessary to position the peak of the blade parallel to the polishing line, the work can be performed by removing the adjustment plate from the blade fixing portion.

[Brief description of the drawings]

FIG. 1 is an overall front view showing an embodiment of a blade polishing apparatus having a blade edge adjusting function according to the present invention.

FIG. 2 is an overall side view of the blade polishing apparatus shown in FIG.

FIG. 3 is a view showing an adjustment plate in the blade polishing apparatus shown in FIG. 1, wherein A is a plan view and B is a front view.

FIG. 4 is a view showing a tool rest in the tool polishing apparatus shown in FIG. 1, wherein A is a plan view and B is a front view.

5A is a side view of a tool post in the tool polishing apparatus shown in FIG. 1, and FIG. 5B is an enlarged view near a fixing bolt in FIG. 4B.

FIG. 6 is a plan view showing a blade.

FIG. 7 is an overall front view showing a conventional polishing apparatus.

8 is a view showing a tool rest in the polishing apparatus shown in FIG. 7, wherein A is a plan view, B is a front view, and C is a side view.

[Explanation of symbols]

 4 Adjustment plate 4M Contact surface 6 Tool rest 7a, 7b Scale part 8 Fixing bolt 10 Tool 10F ···· Cutting edge 10B ···· Mineral part L1 ··· Polishing line

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-101357 (JP, A) JP-A-57-73053 (JP, U) JP-A-59-162203 (JP, U) JP-A-59-162203 42051 (JP, U) Japanese Utility Model Showa 56-166139 (JP, U) Japanese Utility Model Showa 57-131239 (JP, U) Japanese Utility Model Utility Model 4-133563 (JP, U) Japanese Utility Model Utility Model 5-72358 (JP, U) Jikken Sho 31-14992 (JP, Y1) Jikken Sho 41-20957 (JP, Y1) (58) Fields investigated (Int. Cl. ⁶ , DB name) B24B 3/36 B24B 41/06

Claims (3)

(57) [Claims] An adjustment plate having a blade fixing portion to which a blade is mounted, a polishing portion for polishing a blade edge of the blade mounted on the blade fixing portion along a predetermined polishing line, and a contact surface which comes into contact with a ridge portion of the blade. An adjustment plate having a contact surface positioned substantially parallel to the polishing line and slidably attached to the blade fixing portion so as to move while maintaining a parallel state between the contact surface and the polishing line. And a fixture for fixing the position of the adjustment plate in the blade fixing portion. 2. A blade polishing apparatus having a blade tip adjusting function according to claim 1, wherein two or more parallel scales are formed at two or more positions of the blade fixing portion, wherein the two or more parallel scales are: A blade polishing apparatus having a cutting edge adjustment function, which is associated with the polishing line substantially in parallel, and indicates a reference for parallel movement of the adjustment plate with respect to the polishing line. 3. The blade polishing apparatus having a blade edge adjusting function according to claim 1, wherein the adjusting plate is detachably attached to the blade fixing portion. apparatus.