JPH01148502A - Dust collecting mechanism of portable dust collecting circular saw - Google Patents

Abstract

PURPOSE: To prevent the discharge of dust to the rear of a base by providing the cooling air emitting orifice of an electromotor to the inner wall part of a gear cover and emitting cooling air to the air curtain groove provided so as communicate with the cooling air emitting orifice. CONSTITUTION: The almost upper peripheral part of a rotary edge tool is covered with a gear cover 2 and a saw cover 9 and the almost lower falf peripheral part thereof is covered with the shafety cover 8 shaken centering around an output shaft. The dust cut by the rotary edge tool 7 is discharged to a dust collecting case 1 from a dust discharge port 5 to be accumulated therein. Herein, since cooling air sent from the cooling fan 10 of an electromotor is sprayed on the side surface and outer peripheral part of the rotary edge tool 7 from a cooling air emitting orifice 3 through an air curtain groove 4, the gap between the gear cover 2 and the rotary edge tool 7 is partitioned by the air curtain of cooling air and the dust not perfectly discharged to the dust discharge port 5 to be ready to flow out to the rear of a base 6 is prevented in advance by the air curtain groove 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a dust collection mechanism in a portable dust collection circular saw.

[Background of the invention]

A conventional dust collection circular saw is shown in Figure 3. Most of the dust cut by the rotary blade 7 is discharged into the dust collection case 1 from the dust discharge port 5 as indicated by the thick arrow. At this point, the dust that is not discharged into the dust collection case 1 is scattered toward the rear of the base 6 as indicated by the thin arrow, resulting in a disadvantage that the dust collection performance is degraded.

[Purpose of the invention]

The purpose of the present invention is to eliminate the drawbacks of the prior art mentioned above,
Our objective is to provide a circular saw with high dust collection efficiency.

[Summary of the invention]

The present invention prevents dust from being discharged to the rear of the base by providing a cooling air outlet for the electric motor on the inner wall of the gear cover and discharging the cooling air into an air curtain groove that is connected to the air curtain groove. It was devised.

[Embodiments of the invention]

An embodiment of the invention is shown in FIGS. 1 and 2.

A rotary cutter 7 is fixed to an output shaft to which power is transmitted from an electric motor via gears or the like. Approximately the upper half of the rotary cutter 7 is covered with a gear cover 2 and a saw cover 9, and the upper half of the rotary cutter 7 is covered with a safety cover 8 that swings around the output shaft. The dust cut by the rotary blade 7 is discharged from the dust discharge port 5 to the dust collection case 1 and accumulated therein.

Cooling air blown from the cooling fan 10 of the electric motor is blown from the cooling air outlet 3 through the air curtain groove 4 to the side surface and outer circumference of the rotary cutter 7.

Therefore, the gap between the gear cover 2 and the rotary cutter 7 is partitioned off by an air curtain created by the cooling air.

As a result, the dust that cannot be completely discharged to the dust outlet 5 and attempts to flow out to the rear of the base 6 is prevented from advancing by the air curtain groove.

〔Effect of the invention〕

According to the present invention, since the cooling air outlet of the electric motor and the air curtain groove are provided on the inner wall of the gear cover, the gap between the gear cover and the rotary cutter is partitioned by the cooling air, and the outflow of dust from here to the rear is prevented. can be prevented.

No. ll81! J shows the pros and cons of L due to non-freezing, Fig. 2 is a partial sectional view taken along line A-A in Fig. 1, and Fig. 3 is a front view showing a conventional Hayabusa circular saw. .

1 is a dust collection case, 2 is a gear cover, 3 is a cooling air outlet, 4 is an air curtain groove, 5 is a dust outlet, 6 is a base, 7 is a rotary knife, 8 is a safety cover, 9 is a saw cover, ]-〇 is It is a cooling fan.

Patent applicant name: Hitachi Koki Co., Ltd. 26th Figure

Claims (1)

[Claims] In a portable dust-collecting circular saw consisting of a rotary blade driven by an electric motor, a gear cover that covers the rotary blade, a base for setting the cutting depth, and a dust collection case for accumulating cutting dust, the inner wall of the gear cover is A portable dust collection circular saw dust collecting mechanism, characterized in that a cooling air outlet of the electric motor is provided, and an air curtain groove communicating with the cooling air outlet is provided facing toward the outer circumference of the rotary cutter.