JPH08207014A - Portable electric circle saw - Google Patents

Abstract

(57) [Summary] [Purpose] In a portable electric circular saw, prevent the cutting chips from being blown out from the viewing window provided to visually check the tooth tips during cutting work. [Structure] An air blowout hole 10 is provided on a side portion of a gear casing portion 2a, and a wind generated by a fan of the motor through the air blowout hole 10 is cut into a blade case 2 for visually observing a cut portion. The discharge is performed toward the vicinity of the formed viewing window 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable electric circular saw, and more particularly to a structure for blowing off chips in the vicinity of a viewing window.

[0002]

2. Description of the Related Art When a cutting operation is performed using an electric circular saw, when the circular saw is grasped in an appropriate direction, the back side of the blade is shielded by the blade case, so that the tooth tip, that is, the cutting point cannot be visually observed. Therefore, conventionally, a peep window is cut out at an appropriate portion, for example, the front portion of the back surface of the blade case, so that the operator can see the cut portion on the back surface side of the blade case.

[0003]

However, in the case where the viewing window is simply cut out as described above,
There is a problem that cutting chips are blown out from the viewing window during the cutting work and are blown toward the worker. Here, by shielding the viewing window with a transparent resin plate or the like, the problem of blowing chips is solved, and it is also possible to visually check the tooth tips. Since it will not function as a peep window immediately after adhering to, it is necessary to wipe off the adhering chips often, but this wiping work is said to have a very small gap between the blade and the blade case. For structural reasons, it is not possible without removing the blade, and therefore, using a transparent resin plate for the viewing window is not a realistic solution.

The present invention has been made in view of the above problems, and there is no problem as in the case where the viewing window is shielded by the transparent resin plate as described above, and the tooth tips can be visually observed through the viewing window. Moreover, it is an object of the present invention to provide a portable electric circular saw that can prevent the chips blown from the viewing window from being blown to an operator.

[0005]

Therefore, according to the invention of claim 1, an air blowout hole is provided in a side portion of the gear casing part, and the wind generated by the fan of the motor is passed through the air blowout hole, The present invention is characterized in that the blade is discharged toward the vicinity of a viewing window formed in a notch in the blade case for visually observing the cut portion.

[0006]

According to the structure of the first aspect, the chips blown from the viewing window are blown forward in the cutting direction by the air discharged from the air blowing holes. Note that the peep window is usually provided in the front part of the back surface of the blade case for that purpose, so that the gear casing part provided with the air blowing hole is located behind the peep window. Therefore, the air discharged from the air blowing hole toward the vicinity of the viewing window becomes a flow of air toward the front in the cutting direction, forming a kind of air curtain. Also, if the operator grips the circular saw in an appropriate direction, the operator will be positioned behind the circular saw in the cutting direction, so if the chips discharged from the viewing window are blown forward in the cutting direction, the chips will be cut off. It will not be sprayed on the worker.

[0007]

According to the first aspect of the present invention, the chips blown out from the viewing window provided to visually check the tooth tips are blown forward in the cutting direction, so that they are not blown to the operator. , The tip of the tooth is easier to see.

[0008]

Next, an embodiment of the present invention will be described with reference to FIGS. The figure shows the front part of the electric circular saw 1 (the front part in the cutting direction, the same applies hereinafter). Reference numeral 2 in the drawing denotes a blade case in which a gear casing 2a is integrally formed on the back surface (the surface on the front side in the drawing), and a disk-shaped blade 3 is mounted inside the blade case 2. Reference numeral 4 is a base, and the base 4 is attached rotatably in the vertical direction via a rotation support portion 2b at the front end portion of the blade case 2, whereby the cutting depth can be adjusted. There is.

The rotation supporting portion 2b of the blade case 2
Immediately behind (on the right side in the figure), the tooth tip (cutting point,
A viewing window 5 is formed in a notch at a side portion of the same. An operator located on the rear side in the cutting direction can see the tooth tips from the back side (front side in the drawing) of the blade case 2 through the viewing window 5.

On the side of the viewing window 5 (front side in the drawing),
A plurality of arch-shaped shielding fences 6 to 6 are provided at appropriate intervals (illustrated by three in the figure) within a range that does not significantly obstruct the line of sight of the operator. It is designed to prevent the cutting chips blown out from No. 5 from being blown sideways as they are. An inside of the shielding fence 6 (on the side of the peep window 5) serves as a ventilation path 7 along the front and rear in the cutting direction.
The air (wind) discharged from is smoothly blown from the rear to the front in the cutting direction.

The air blow-out hole 10 is provided at a side portion of the gear casing portion 2a on the front side in the cutting direction, which is substantially rearward of the ventilation passage 7. As shown in FIG. 2, a motor 12 as a drive source of the marunoco 1 is internally housed in a motor case 11 connected to the gear casing 2a, and an output shaft 12a of the motor 12 has a motor 12a. A cooling fan 13 is attached. By the rotation of the fan 13, the motor case 1
External air is sucked in from the rear surface (not shown) of the No. 1 and the sucked air flows forward (upward in the drawing) while cooling the motor 12, and then into the air chamber 15 in front of the fan 13. Pour in. This air is the air blowing hole 10
After that, it is discharged toward the vicinity of the sight glass 5 located in the front. This flow of air (exhaust air) is indicated by a white arrow in the figure. In addition, this air blowing hole 10
Is a circular hole having a small diameter, and is provided with a relatively small opening area, so that it is narrowed further than in the air chamber 15 and is blown out strongly.

A rib 16 is formed on the back surface of the blade case 2 so as to extend above the ventilation path extending from the air blowing hole 10 to the ventilation path 7.
The air blown out from the air blowing hole 10 is guided by 6 while being suppressed from being diffused, and efficiently reaches the inlet of the ventilation passage 7. However, this rib 1
Reference numeral 6 is formed so as to extend in a range that does not block the line of sight of the operator located at the rear during the cutting work to the peep window 5.

According to the portable electric circular saw of the present embodiment configured as described above, when the motor 12 is rotated, the exhaust air is exhausted from the air blowing hole 10 toward the front, that is, in the vicinity of the sight window 5. . That is, the air discharged forward from the air blowing holes 10 is guided by the ribs 16 and efficiently flows into the ventilation passage 7. On the other hand, at the time of cutting work, a part of the chips scattered from the vicinity of the tooth tip is blown out through the observation window 5 to the back surface side of the blade case 2, that is, in the ventilation passage 7. However, in the ventilation passage 7, a flow of air blown from the rear to the front by the flow of the air discharged from the air blowing holes 10 (a flow indicated by a white arrow in the figure) is formed, and the air curtain is closed. Since it is formed, the chips blown out through the viewing window 5 ride on this air flow and are immediately blown forward from the front exit of the ventilation passage 7. Further, even if the cutting chips blown out through the peep window 5 during the cutting work are slightly discharged to the side through the gap between the shielding fences 6 and 6, they are blown forward by the air discharged from the air blowing holes 10. , It will not be sprayed on the worker.

The viewing window 5 is simply the blade case 2
Since it is formed by cutting out, the chips do not adhere as in the case of being shielded by the transparent resin plate,
The function as a viewing window can be maintained without any trouble.

In the present embodiment, the description has been given by taking as an example a type of circular saw in which the gear casing 2a is integrally provided on the blade case 2, but this gear casing is not integrally provided on the blade case 2 side but on the motor case 11 side. Even if it has a provided structure, it is applicable similarly.

[Brief description of drawings]

FIG. 1 is a perspective view showing a front part of a circular saw according to an embodiment of the present invention.

FIG. 2 is likewise a plan view showing the front part of the circular saw.

FIG. 3 is likewise a rear view showing the front part of the circular saw.

[Explanation of symbols]

 2 ... Blade case, 2a ... Gear casing part 5 ... Peep window, 6 ... Shield fence, 7 ... Ventilation path 10 ... Air blowing hole 11 ... Motor case, 13 ... Fan, 15 ... Air chamber 16 ... Rib

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Masahiko Ono 3-11-8 Sumiyoshi-cho, Anjo City, Aichi Prefecture Makita Co., Ltd. (72) Inventor Noda Ariya 3-11-8 Sumiyoshi-cho, Anjo City, Aichi Prefecture Stock Company Makita

Claims (1)

[Claims] 1. An air blowout hole is provided on a side portion of a gear casing part, and a notch is formed in a blade case for visually observing a cut portion of the wind generated by a fan of the motor through the air blowout hole. A portable electric circular saw that is configured to discharge toward the vicinity of the viewing window.