JP2523615Y2 - Dustproof circular saw - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application field] Conventionally, in a dust collecting circular saw, a cutting dust is formed in a space formed by a front portion of a housing, a front side of a saw cover, and an upper front portion of a base. And a dust introduction passage communicating between the inside of the saw cover and the dust collection case so as to guide cutting dust scattered from a rotary blade to the dust collection case. Is Akai Kai
It is known from JP 61-87901.

[Problems to be solved by the invention]

However, in the above-mentioned conventional dust collecting circular saw, since the dust collecting case is installed in the space formed by the front part of the housing, the front side of the saw cover, and the upper front part of the base, it is difficult to cut. The marking line and the sumi line of the material are hidden in the dust collecting case, making it difficult to see.Also, an arc-shaped long hole for guiding and fixing the lower guard is opened in the saw cover, as well as a guide that covers the front of the rotary blade When adjusting the base to reduce the depth of cut by the rotating blade,
Since the gap with the tip (edge) of the rotary blade is widened, dust generated during cutting by the rotary blade is discharged from the long hole and the gap together with the airflow generated at the rotational peripheral speed of the rotary blade. Therefore, there are problems such as poor dust collection efficiency.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the related art, and an object thereof is to provide a dustproof circular saw capable of improving cutting workability and dust collection efficiency. It is assumed that.

[Means for solving the problem]

In order to achieve the above object, a dustproof circular saw according to the present invention includes a housing having a driving motor, a handle attached to the housing, and a rotary saw blade safety cover attached to an end of the housing. A rotary case, which is disposed in the safety cover and driven by the driving motor, and a base disposed below the housing, and a lower portion of the rotary saw blade projects downward. In the saw, a dust case is detachably disposed above the housing and the gear case, and a dust introduction passage is formed between the gear case and the safety cover at a position above the rotary saw blade and above the rotary saw blade. A duct opening for guiding dust and air generated at the time of cutting by the rotary saw blade to the dust case is opened to the upper side of the housing in a tangential direction of the rotary saw blade. An exhaust port is provided adjacent to the duct port and connected to the dust introduction path, and an exhaust path for guiding air in the dust case from the exhaust port to the lower portion of the dust introduction path is provided inside the gear case. The duct opening is defined by a dustproof plate provided, while the safety cover has a cover piece at its tip for covering the tip of the rotary saw blade at a predetermined interval, and the front part of the rotary saw blade is provided. A guide for covering is rotatably pivoted on the same axis as the rotary saw blade so as to be rotatable following the cutting depth adjustment of the base, and an operation lever of a lower guard is mounted coaxially with the guide. I have.

[Action]

By rotary saw blade driven by drive motor,
When the material to be cut is cut, cutting dust is generated. The dust is taken up in the tangential direction of the rotating direction of the rotary saw blade together with the airflow generated at the peripheral speed of the rotary saw blade, and the dust is introduced. After passing through the passage, it is discharged into the dust case from the dust port. Dust entering the dust case is accumulated in the dust case, but the air sent together with the dust is guided from the exhaust port to the lower side of the dust introduction passage along the side surface of the dustproof plate, and the dust is again introduced together with the dust. It passes through the passage and is discharged from the duct opening into the duct case. As a result, the dust case internal pressure drops, so that dust accumulates.

When the base is lowered in order to reduce the cutting depth, the guide covering the front part of the rotary saw blade follows the guide, and the guide is lowered, but the guide moves on the same axis as the center of the rotary saw blade. Since it rotates about the center, the gap between the tip of the rotary saw blade and the guide is kept constant, so that dust is not scattered from the gap, thereby improving dust collection efficiency.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 to 3, the housing 1 has a drive motor 2 built therein. A saw shaft 5 is rotatably mounted horizontally on bearings 6 and 6 in a gear case 4 screwed to a front end (right end in FIG. 3) of the housing 1 as shown in FIG. The saw shaft 5 is linked to the motor shaft 2a via a gear transmission mechanism 7 and is removably fixed to the saw shaft 5 via a receiving bracket 8, a holding bracket 9 and a washer 10 with a tightening bolt 11. Blade 12 is first
It is driven and rotated in the direction of arrow a in the figure.

At the end of the gear case 4 (the left end in FIG. 2), a safety cover 13 that covers a substantially upper half of the rotary saw blade 12 is provided, and is provided between the safety cover 13 and the side wall 4a of the gear case 4. Further, a dust introduction passage 14 is formed at a position above the rotary saw blade 12 from the front.

At the upper end of the dust introduction passage 14, a duct port 15 is provided in the tangential direction of the rotation direction of the rotary saw blade 12, and an exhaust port 23 is provided in front of the duct port 15 on the upper side of the housing 1 (upper side in FIG. 3). ).

A dust case 16 is removably mounted on the housing 1 and the gear case 4 by screws or the like.
The dust case 16 is fitted to the housing 1 and a handle 18 fixed to the rear end (left end in FIG. 1) of the housing 1 with screws 17. 7 is formed so that it can be stably mounted on the upper part of the gear case 4 and does not protrude upward, and has an opening 19 at one side. And is airtightly connected to the duct port 15.

Here, the dust case 16 can be freely opened and closed by the hinge 20 on the lid 16b of the main body 16a so that dust accumulated inside can be discharged even when the dust case 16 is mounted on the housing 1 and the upper part of the gear case 4. In addition, it is preferable to be formed so as to be pivotally attached so as to be able to close the lid in an airtight manner, and to be formed of a transparent member so that dust can be seen through from the outside.

Also, inside the gear case 4, as shown in FIG. 1 to FIG.
Are fixed by screws 22..., Whereby the upper end communicates with the exhaust port 23, the lower end communicates with the lower end of the dust introduction passage 14, and is separated from the duct port 15. The air introduced together with the dust into the dust case 16 flows from the exhaust port 23 through the inner surface 21a of the dustproof plate 21 through the exhaust port 23 as shown by the dashed arrow b in FIG. 1 and the arrow c in FIG.
An exhaust passage 24 is formed to flow down along the gap and exhaust the dust to the lower end of the dust introduction passage 14.

The air discharged from the dust case 16 together with the dust passes through the dust introduction passage 14 in the direction indicated by an arrow d shown by a solid line in FIG.
And is introduced into the dust case 16 from the duct opening 15.

The safety cover 13 is provided with a dust hose mounting port 25 to which a dust hose (not shown) is connected when a dust collector (not shown) is used, as shown by a two-dot chain line in FIGS. 1 and 3. .

Below the housing 1, a base 26 is pivotally connected at its front end (right end in FIG. 1) to the safety cover 13 by a shaft 27, and is rotatably arranged in a vertical direction around the shaft 27 as a fulcrum. ing.

The base 26 has a long hole 26a protruding downward from the lower portion of the rotary saw blade 12 formed long in the front-rear direction,
At the rear end (the left end in FIG. 1), a curved guide plate 28 is fixed in a vertically long shape, and the tightening screw 29 inserted into a guide hole (not shown) which is long in the longitudinal direction of the guide plate 28 is inserted. Protrude outward from the safety cover 13 and tighten the tightening screw 29.
The adjusting knob 30 is screwed on the rim.

Thus, by loosening the adjustment knob 30, the base 26
As shown in FIG. 5, the shaft 27 can be rotated in the vertical direction as a fulcrum, whereby the depth of cut of the workpiece (not shown) by the rotary saw blade 12 can be arbitrarily adjusted to be deep or shallow. By tightening the knob 30, the base 26 is fixed at the adjusted position.

Further, a lower guard 31 for opening and closing the lower part of the rotary saw blade 12 is provided at the end of the gear case 4 so as to be rotatable on the same axis as the rotary saw blade 12 and covers the rotary saw blade 12. The lower guard 31 is held in contact with a stopper 37 against the urging force of the spring 32.

Since the lower guard 31 needs to hold the rotary saw blade 12 in an exposed state depending on the cutting mode of the workpiece, the guide 33 and the operation lever 34 supporting the lower guard 31 are provided inside the safety cover 13. And third as external arrangement
As shown in the figure, the safety cover 13 is rotatably supported by a screw 35 on an extension of the axis of the rotary saw blade 12. Specifically, the operation lever 34 and the guide 33 are integrally connected by a screw 35, and the operation lever 34 is rotated around the extension of the saw shaft 5 so that the lower guard is 31 is rotated so that the rotary saw blade 12 is exposed or shielded.

The guide 36 has a cover piece 36a at its distal end which covers the distal end of the rotary saw blade 12 at a predetermined interval e.

That is, the guide 36 rotates following the rotation of the base 26 (adjustment of the cutting depth by the rotary saw blade), and the rotary saw blade 12
And the interval e is always constant.

[Effect of the invention]

Since the present invention is configured as described above,
By arranging the dust case 16 above the housing 1 and the gear case 4, a wide field of view in front of the circular saw can be secured, so that the marking line can be easily seen and the cutting workability of the circular saw can be improved. Can be improved.

Further, the dust that is wound up together with the air flow generated at the rotation speed of the rotary saw blade 12 passes through the dust introduction passage 14 and passes through the duct port 15.
Is introduced into the dust case 16 and accumulates, and the air is discharged from the exhaust port 23 defined by the duct port 15 to the lower portion of the dust introduction path 14 through the exhaust path 24, and again from the duct port 15 together with the dust. Although introduced into the dust case 16, the duct port 15 is provided in the position where the dust collection efficiency is the best in the tangential direction of the rotation direction of the rotary saw blade 12, and the Guide 36 that covers the front part is based
Rotate following the cutting depth adjustment operation of 26, and rotate the saw blade 12
Not only always covers the front part, but also has a constant distance e from its predecessor, and the safety cover 13 does not have a long hole for the operating lever of the lower guard 31 as in the conventional example. In addition to this, the scattering of dust is prevented, so that a dustproof circular saw with high dust collection efficiency can be provided.

[Brief description of the drawings]

FIG. 1 is a side view showing a dust-proof circular saw according to the embodiment of the present invention with a safety cover removed, FIG. 2 is a front view partially showing the embodiment, and FIG. 3 is the embodiment. FIG. 4 is a plan view showing a part of the dust case, FIG.
FIG. 5 is a sectional view showing an exhaust port and an exhaust passage, FIG. 5 is a side view showing the relationship between the rotary saw blade, a base and a guide in the embodiment, and FIG. FIG. 7 is a cross-sectional view showing the relationship between the plate and the guide, and FIG. 7 is a perspective view showing the dust case of the embodiment. DESCRIPTION OF SYMBOLS 1 ... Housing, 2 ... Drive motor 4 ... Gear case, 12 ... Rotary saw blade 13 ... Safety cover, 14 ... Dust introduction passage 15 ... Dust port, 16 ... Dust case 18 ... Handle, 21 ... Dustproof plate 23 ... Exhaust port , 24 ... Exhaust passage 26 ... Base, 31 ... Lower guard 34 ... Operation lever, 36 ... Guide

Claims (1)

(57) [Scope of request for utility model registration] 1. A housing containing a driving motor,
A gear case having a handle attached to the housing, a rotating saw blade safety cover attached to an end of the housing, and a rotating saw blade disposed in the safety cover and driven by the driving motor. A circular saw comprising a base disposed below the housing and having a lower portion of the rotary saw blade protruding downward, a dust case is removably disposed above the housing and the gear case, and the gear case and the A dust introduction passage is formed between the safety cover and an upper portion from the front of the rotary saw blade, and a duct opening for guiding dust and air generated at the time of cutting by the rotary saw blade to the dust case is provided on the rotary saw blade. Opening at the upper side of the housing in the tangential direction to the dust introduction passage, and providing an exhaust port adjacent to the duct port; An exhaust passage that guides the air in the air from the exhaust opening to the lower portion of the dust introduction passage is defined by the dust opening provided by the dust-proof plate provided inside the gear case. A guide that has a cover piece that covers the tip of the rotary saw blade at a predetermined interval and covers a front portion of the rotary saw blade is rotatable in accordance with adjustment of a cutting depth of a base, and is rotatable in the same manner as the rotary saw blade. A dustproof circular saw which is pivotally mounted on an axis and has a lower guard operating lever mounted coaxially with the guide.