JP3434957B2 - Rotary blade mounting device for power tools - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for attaching a rotary blade to a spindle in an electric tool such as a circular saw.

[0002]

2. Description of the Related Art Conventionally, a mounting device of this type has a structure in which a ring is inserted in a mounting hole (inner peripheral hole) of a rotary blade to mount it on a spindle. Since the diameter varies depending on its outer diameter (size) (usually two types, large diameter and small diameter), when using different rotary blades, replace it with a ring that matches the mounting hole diameter of the rotary blade to be used. The ring was stored separately and could be lost. Therefore, as a conventional technique for solving this problem, for example, there is one disclosed in Japanese Utility Model Publication No. 56-33681. According to this prior art, the inner flange for sandwiching the rotary blade with the outer flange is formed with fitting portions on both sides of which the rotary blades having different mounting hole diameters can be fitted, respectively, and the rotary blade to be used is used. According to the diameter of the mounting hole of the blade, the inner flange is reversed to mount the rotary blade.

[0003]

However, according to the above-mentioned prior art, although the problem of losing the ring on the unused side is solved, it takes time and labor to form the fitting portions on both side surfaces of the inner flange. Further, since it has a shape different from that of the outer flange, it cannot be shared as in the conventional case, which not only complicates parts management, but also raises the cost.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a rotary blade mounting device which does not cause a loss of a ring on an unused side and does not cause a cost increase. To do.

[0005]

Therefore, according to the first aspect of the present invention, a plurality of types of ring members having different outer diameters are prepared corresponding to the difference in the mounting hole diameter of the rotary blade, and the ring hole is adapted to the mounting hole diameter. A device for mounting the rotary blade on a spindle via the ring member, sandwiching the mounted rotary blade with an outer flange and an inner flange, and mounting the rotary blade on the spindle through the sandwiched state. A ring member that does not fit among the plurality of ring members is configured to be fixed on the spindle by using a sandwiching force between the outer flange and the inner flange.

According to the above structure, the ring member that does not fit, that is, the ring member that is not mounted in the mounting hole of the rotary blade,
Since it is fixed on the spindle like a matching ring member, it does not need to be stored separately as in the conventional case, and therefore it is not lost.

Further, since it is not a structure in which fitting portions having different diameters are integrally formed on the inner flange or the outer flange and used in reverse as in the conventional case, both flanges can have the same shape. There is no increase in cost.

The invention according to claim 2 is the mounting device according to claim 1, wherein the sandwiching force between the outer flange and the inner flange is generated only when an incompatible ring member is mounted on the spindle. It is characterized by

According to the above construction, when the incompatible ring member is stored in another place as in the conventional case, the rotary blade cannot be attached, and in this respect, the incompatible ring member can be more reliably prevented from being lost. .

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, one embodiment of the present invention is shown in FIG.
It will be described based on. FIG. 1 is a part of an electric circular saw as an example of an electric tool and shows a mounting device 1 for mounting a rotary blade 2 on a spindle 3.

Reference numeral 4 in the drawing denotes an output gear of the drive motor,
A bevel gear 5 is meshed with the output gear 4, and the bevel gear 5 is attached to the spindle 3 via a key 6. Therefore, when the drive motor is activated, the spindle 3 rotates through the meshing of the gears 4 and 5. The bevel gear 5 is axially fixed by a retaining ring 9 and a collar 3a provided on the spindle 3.

The spindle 3 is supported between the motor case 20 of the circular saw body and the bearing case 10 fixed to the motor case 20 via bearings 7 and 8 so as to be rotatable and immovable in the axial direction. There is. Bearing case 1
On the right side of the inner ring of the bearing 7 housed in
And a retainer 10a fixed to the bearing case 10 is in contact with the left side surface of the outer ring.

In the present embodiment, the rotary blade 2 can be attached to the rotary blade 2 in two types, large and small, with respect to the diameter of the mounting hole 2a.
The ring member fitted in a is also prepared in two sizes, large and small, in terms of outer diameter. Hereinafter, a rotary blade of a type having a large mounting hole 2a is denoted by 2L, and the mounting hole 2a is attached.
2S is attached to the rotary blades of small type to distinguish them.

Although the difference between the outer diameters of the ring members 11 and 12 is not clearly shown in the drawing, a ring member 11 having a small outer diameter (hereinafter referred to as "small ring member") 11 is a rotary blade 2. A state in which a ring member 12 having a large outer diameter (hereinafter, referred to as a “large ring member”) 12 fitted in the mounting hole 2a is sandwiched between the inner flange 13 and the left side surface of the inner ring of the bearing 7 is shown. There is.

That is, the retainer 10 of the spindle 3
A large ring member 12 is first attached to the tip portion protruding leftward from a in the figure, and then an inner flange 13 is attached, and then a small ring member 11 fitted in the attachment hole 2a. The rotary blade 2S is attached via the rotary blade 2S, then the outer flange 14 is attached, and finally, the fixing bolt 15 is tightened on the end surface of the spindle 3 to fix the rotary blade 2S.
Installation of S is completed. The tightening force of the fixing bolt 15, a large ring member 1 2, inner flange 1 3, small ring member 1 1 and the outer flange 14, sandwiched between the left end surface of the inner ring of the bearing 7, thereby, the rotation The blade 2S is sandwiched between the outer flange 14 and the inner flange 13, and the rotary blade 2S is indirectly attached to the spindle 3 so as not to rotate relative to the spindle 3.

A two-face width portion 3b is formed at the tip of the protruding portion of the spindle 3, and although not shown, the two-face width portions 3b correspond to the two-face width portion 3b. The width portion is formed to be bulged so that both flanges 13 and 14 are rotationally fixed to the spindle 3.

When mounting a rotary blade 2L of a type having a large diameter mounting hole 2a, the fixing bolt 15 is removed and both the flanges 13 and 14 and the large and small ring members 12 and 11 are removed from the spindle 3. First, the small ring member 1
1 is mounted on the spindle 3, and then the inner flange 1
3 is mounted, then the rotary blade 2L in which the large ring member 12 is fitted in the mounting hole 2a is mounted, and then the outer flange 14 is mounted, and finally the fixing bolt 15 is tightened. 2L installation is completed.

As described above, according to this embodiment, two types of rotary blades 2L and 2S of large size and small size can be mounted with respect to the diameter of the mounting hole 2a, and a ring member (small size in the drawing is suitable for the mounting hole 2a of the mounting type). The ring member 11) is fitted into the mounting hole 2a and used directly for mounting the rotary blade 2 as in the prior art. However, the ring member (large ring member 12 in the figure) that does not fit is the inner flange 13 and the bearing 7. It is sandwiched between the inner ring. As a result, there is no need to store the incompatible ring member 12 (or 11) in another place as in the conventional case, and therefore there is no risk of loss, and both ring members 11 and 12 have inner flange 13 or Since it is formed separately from the outer flange 14, when the fitting portions corresponding to the silling members 11 and 12 are integrally formed with the inner flange as in the prior art (the technique disclosed in Japanese Utility Model Publication No. 56-33681). Since it is possible to maintain the two flanges 11 and 12 as a common component, it is possible to reduce the manufacturing cost because there is no need to take the labor of machining in step 1.

According to the configuration of this embodiment, the spindle 3
Since the movement of the spindle 3 in the slip-out direction is blocked by the collar portion 3a, the spindle 3 can be firmly fixed in the slip-out direction, and the spindle 3 can be incorporated without looseness in the axial direction.

Further, in this embodiment, the ring member 12 (or 11) which is not directly used for mounting the rotary blade 2 is arranged so as to be interposed between the inner flange 13 and the bearing 7, and the fixing bolt 15 is tightened. By sandwiching it between the inner flange 13 and the bearing 7 using the inserting force,
It is configured to have a function of generating a sandwiching force between the outer flange 14 and the inner flange 13 by tightening the fixing bolt 15.

Further, the ring blade 12 (or 11) which does not fit is configured to be completed by sandwiching the ring member 12 (or 11) which does not fit between the inner flange 13 and the bearing 7. When the flanges 13 and 14 and the rotary blade 2 are mounted and the fixing bolts 15 are tightened without sandwiching 11) between the inner flange 13 and the bearing 7, the inner flange 13 causes the inner flange 13 to move.
Since it comes into contact with a, it interferes with the rotation of the rotary blade 2.
Thus, the incompatible ring member 12 (or 11)
Since the rotary blade 2 is not attached unless it is set to the predetermined position without fail, the ring member 12 (or 11) that is not suitable in this respect can be surely prevented from being lost.

However, various modifications can be made to the illustrated embodiment. For example, the flange portion of the spindle is set on the left side of the bearing 7 and the inner flange 13 is attached to the flange portion as in the conventional case. The ring member 12 (or 11) that does not fit may be directly pressed and fixed by tightening the fixing bolt 15 on the back side (left side in the drawing) of the outer flange 14, and in this case also, the ring is not used. Since it is not necessary to store the member in another place, there is no risk of loss as in the conventional case.

Further, in this case, the thread depth is set so that the fixing bolt 15 cannot be completely tightened unless the ring member 12 (or 11) that does not fit is provided on the back side of the outer flange 14. It is effective to keep the ring member 12 (or 11) that is not compatible with the ring member 12 (or 1).
The loss of 1) can be reliably prevented.

Further, in the illustrated embodiment, two types of rotary blades 2S and 2L can be attached with respect to the diameter of the attachment hole 2a, and thus two types of ring members 1 having different outer diameters.
Although the example in which 1 and 12 are exchanged is used, for example, the dimensions and the like of each part are set so that the rotary blade 2 can be attached by sandwiching three or more ring members between the inner flange 13 and the bearing 7. Therefore, the present invention is similarly applicable to three or more types of rotary blades, and thus three or more types of ring members with respect to the mounting hole diameter.

Further, instead of screwing the fixing bolt 15 into the tip end surface of the spindle 3, a screw shaft portion is formed at the tip end portion of the spindle 3, and a fixing nut is screwed into the screw shaft portion, whereby the outer flange 14 and the inner flange 14 are screwed together. Flange 13
The same can be applied to a mounting device having a configuration in which the rotary blade 2 is sandwiched between and.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a rotary blade attaching device according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Rotary blade mounting device 2 ... rotary blade, 2a ... mounting hole 3 ... Spindle 7 ... Bearing 9 ... Retaining ring 11 ... Small ring member 12 ... Large ring member 13 ... Inner flange 14 ... Outer flange 15 ... Fixing bolt

Claims (2)

(57) [Claims] 1. Corresponding to the difference in the mounting hole diameter of the rotary blade,
A plurality of types of ring members with different outer diameters are prepared, the rotary blade is mounted on the spindle via a ring member suitable for the mounting hole diameter, the rotary blade in the mounted state is sandwiched by the outer flange and the inner flange, and the sandwiched A device for attaching the rotary blade to the spindle through a state, wherein an incompatible ring member of the plurality of ring members can be fixed on the spindle. Blade mounting device. 2. The electric device according to claim 1, wherein the clamping force between the outer flange and the inner flange is generated only when a ring member that does not fit is mounted on the spindle. Device for mounting rotary blades on tools.