JPH0120084Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial field of application) This invention relates to a dust collector for cutting waste in an electric circular saw.

(Prior Art) Examples of conventional technologies include, for example, Japanese Utility Model Publication No. 47-36949 and Japanese Utility Model Publication No. 52-28225.

(Problem to be solved by the invention) With a conventional circular saw, when cutting waste is continuously discharged into the dust collection bag attached to the outlet of the cutting waste discharge passage, the amount of cutting waste in the dust collection bag is There was a problem in that the air pressure inside the dust collection bag increased over time due to an increase in air pressure and clogging of the dust collection bag, resulting in a decrease in dust collection efficiency.

An object of the present invention is to provide a dust collecting device for a circular saw that can suppress the increase in air pressure in the dust collecting bag and improve the dust collecting effect.

(Means for Solving the Problems) The present invention provides a dust collecting duct near the rear end which is curved approximately along the cutting edge circle of the saw blade in order to form a dust collecting path through which cutting waste flows. In order to fit a dust collection bag into which the cutting waste discharged from the dust collection path is fed, a mounting opening formed approximately along the tangent of the blade edge circle is provided with the inside of the dust collection bag and the upper part of the saw blade. The gist of the dust collector is a dust collector having a communication path extending through the blade chamber to communicate with the blade chamber in which the blade chamber is housed.

(Function) The dust collector of the present invention constantly cleans the blade chamber in which the saw blade is housed and the dust collection bag attached near the exit of the dust collection path formed along the outer periphery of the blade chamber. This device is configured to automatically flow the air inside the dust bag into the blade chamber when the ventilation characteristics of the dust bag deteriorate, thereby suppressing fluctuations in the air pressure inside the dust bag over time. be.

(Embodiment) Next, an embodiment of the present invention will be described with reference to the drawings. A laterally supported blade shaft 4 is fitted to the blade shaft 2 so as to be able to mesh with a pinion 3 formed on the motor shaft of a motor (not shown).Gears 4 and 5 are fitted to the shaft end of the blade shaft 2. Saw blade 6
This is an outer flange attached to the shaft end of the blade shaft 2 in order to clamp the blade shaft 2 between the inner flange 7 and the inner flange 7. A dust collecting fan 8 is integrally formed with wing pieces 8a to 8a arranged radially.

Reference numeral 9 denotes a base which is placed horizontally at the lower end of the circular saw body M and has a blade opening 9a for inserting the saw blade 6 therethrough;
11 is a movable cover that is rotatably supported on the lower part of the tip of the circular saw body M in order to expose the vicinity of the lower part of the cutting edge of the saw blade 6; 11 is a blade case assembled to the tip of the gear housing 1; Then, the inner surface of this blade case 11 and the gear housing 1
A blade chamber 12 for accommodating the upper part of the saw blade 6 is formed in a substantially semicircular shape from the front. A dust collecting duct 13 is formed in a hollow shape by assembling the two in a butt shape, and the rear end of the dust collecting duct 13 extends horizontally in the tangential direction of the upper end of the cutting edge circle 6a of the saw blade 6.
from the vicinity of the tip of the blade opening 9a to the inside of the dust collection bag 14 inserted through the attachment port 13a at the rear end of the dust collection duct 13.
A dust collection path 1 whose front part is curved approximately along the cutting edge circle 6a of the saw blade 6 and whose rear part extends approximately along the tangent to the upper end of the cutting edge circle 6a in order to change the direction by 90 degrees and guide the dust collecting path 1.
Further, the lower wall 21 of the attachment port 13a of the dust collection duct 13 is connected to the rear end 19b of the partition wall 19 formed to partition the vicinity of the upper end of the blade chamber 12 and the dust collection path 15. ing.

Reference numeral 16 indicates an upper partition wall which is protruded from the inner surface of the blade case 11 and is formed in a curved manner so as to surround the fan 8 almost halfway around and be connected to the front end 19a of the partition wall 19; A lower partition wall protrudes from the side surface and is curved approximately parallel to the front lower part of the upper partition wall 16; 18 is a guide path defined between the upper and lower partition walls 16 and 17 and communicated with the dust collection path 15; Then, the wind K1 generated by the rotation of the fan 8 is introduced into the dust collection path 15 from below, and merges with the wind K2 generated by the rotation of the saw blade 6 slightly above the entrance portion 15a of the dust collection path 15. In order to achieve this, the saw blade 6 is curved into a substantially arc shape from the vicinity of the rotation center to the vicinity of the cutting edge circle 6a, and is connected to the dust collection path 15 in a substantially spiral curve shape, and is connected to the dust collection path 15 near the entrance portion 15a. is decompressed by the wind force of wind K1 and the blade mouth 9a
Nearby cutting debris is sent into the entrance portion 15a together with the wind K2 generated by the saw blade 6. And the entrance part 15a
The cutting waste sent in with the saw blade 6 is guided into the guide path 1.
When passing near the exit part 18a of 8, the guide path 1
Wind K1 flowing into the dust collection path 15 from 8 in a swirling manner
The dust is blown away in the tangential direction of the cutting edge circle 6a, circulates through the dust collection path 15, and is sent into the dust collection bag 14.

Reference numeral 20 denotes a lower wall 21 of the attachment port 13a of the dust collection duct 13 for communicating the inside of the dust collection bag 14 and the inside of the blade chamber 12 to suppress an increase in air pressure inside the dust collection bag 14.
It is a communication path that crosses through the dust collection bag 14, and is used for dust collection when a large amount of cutting waste is fed into the dust collection bag 14 or when the dust collection bag 14 is clogged and the ventilation characteristics of the dust collection bag 14 are deteriorated. The air in the bag 14 is automatically discharged into the blade chamber 12 through the communication path 20 based on the pressure difference with the air pressure in the blade chamber 12, and the air pressure in the dust collection bag 14 is maintained stably.

Next, the operation and effects of the embodiment having the above configuration will be explained.

In this example, the dust is discharged from the dust collection path 15 near the rear end of the dust collection duct 13 which is curved approximately along the cutting edge circle 6a of the saw blade 6 to form the dust collection path 15 through which cutting debris flows. The inside of the dust collection bag 14 and the vicinity of the upper part of the saw blade 6 are accommodated in the attachment opening 13a formed almost along the tangent of the cutting edge circle 6a in order to fit the dust collection bag 14 into which the cutting chips are fed. blade chamber 1
A communication passage 20 is formed to communicate with the inside of the dust collection bag 14 to suppress an increase in air pressure inside the dust collection bag 14.

Therefore, a large amount of cutting waste may accumulate in the dust collection bag 14 due to the cutting operation of the saw blade 6, and the dust collection bag 14 may
Even if the ventilation characteristics of the dust collection bag 14 deteriorate over time due to clogging, the air pressure inside the dust collection bag 14 is prevented from increasing due to the wind flowing from inside the dust collection bag 14 into the blade chamber 12. The dust collection efficiency is improved by accurately suppressing the backflow of cutting waste from inside the dust collection bag 14 into the dust collection path 15 and the decrease in the wind power that discharges the cutting waste from the inside of the dust collection path 15 into the dust collection bag 14. It has the effect of increasing

(Effect of the invention) In other words, the present invention provides a dust collection path near the rear end of the dust collection duct, which is curved approximately along the cutting edge circle of the saw blade, to form a dust collection path through which cutting waste flows. The inside of the dust collection bag and the vicinity of the upper part of the saw blade are accommodated in the mounting opening formed almost along the tangent line of the blade edge circle in order to fit the dust collection bag into which the cutting chips discharged from the saw blade are fed. By installing a communication passage through the blade chamber, the air pressure inside the dust collection bag is prevented from rising, and the wind power that discharges the cutting debris into the dust collection bag is constantly generated. It has an effect that can be ensured.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is a longitudinal sectional view of the main part, Fig. 2 is a partially cutaway front view of a circular saw, and Fig. 3 is a cross section taken along line X-X of Fig. 1. It is a diagram. 6... Saw blade, 6a... Cutting edge circle, 12... Blade chamber, 13... Dust collection duct, 13a... Installation port,
14...Dust collection bag, 15...Dust collection path, 20...Communication path.

Claims (1)

[Scope of utility model registration request] The cutting waste discharged from the dust collection path is fed into the vicinity of the rear end of the dust collection duct, which is curved approximately along the cutting edge circle of the saw blade to form a dust collection path through which the cutting waste flows. The mounting opening, which is formed almost along the tangent of the blade edge circle for fitting the dust collection bag, has a mounting hole for communicating between the inside of the dust collection bag and the blade chamber in which the upper portion of the saw blade is accommodated. A dust collection device for a circular saw, characterized by having a communication passage provided therethrough.