WO2000051785A1

WO2000051785A1 - Hand cutter

Info

Publication number: WO2000051785A1
Application number: PCT/JP1999/001041
Authority: WO
Inventors: Katsunori Komura
Original assignee: Koumu Co., Ltd.
Priority date: 1999-03-04
Filing date: 1999-03-04
Publication date: 2000-09-08

Abstract

A hand cutter, comprising an electric motor (10), a cutter blade (12), a rotating mechanism (13) for the cutter blade (12), and a dust collector (14), the cutter blade (12) being supported detachably by a blade holder (24) located on the left side of the electric motor (10), the rotating mechanism (13) having a driving bevel gear (13a) installed fixedly to the tip end of a counterclockwise rotating shaft part (18a), a driven bevel gear (13b) meshed with the driving bevel gear (18a), and a driven rotating shaft (13c) installed fixedly to the center of rotation of the driven bevel gear (13b), and the dust collector (14) having an exhaust fan (14a) and a fan casing (14b), wherein the cutter blade (12) and the exhaust fan (14b) which are rotated in connection with the rotating shaft (18) of a rotating drive source (electric motor (10)) are disposed on both lateral end sides of the rotating drive source (electric motor (10)), and the exhaust fan (14) is direct-coupled fixedly to the rotating shaft (18) of the rotating drive source (electric motor (10)).

Description

Specification

Technical field of cutter

TECHNICAL FIELD The present invention relates to a hand cutter, and more particularly, to an improvement technology of a dust absorbing structure of a hand cutter. Background art

Hand cutters used for hanging works such as concrete and masonry are used, for example, when forming cuts of several cm at the boundaries of hanging work.

When a notch is formed with a hand cutter, dust may be generated by cutting such as concrete with a power cutter blade, and there is a risk of contaminating surrounding equipment.

Therefore, this type of cutter has conventionally been provided with a dust suction device, and FIG. 3 shows a conventional example of a hand cutter equipped with a dust suction device. The hand cutter shown in the figure has an electric motor 1 as a rotary drive source, a cutter blade 3 removably attached to an output shaft 2 of the motor 1, and a dust suction provided at a rear side of the cutter blade 3. Exhaust fan 6.

A gear box 2a for changing the direction of rotation is interposed between the output shaft 2 and the cutter blade 3. The exhaust fan 6 is driven to rotate by winding a belt 5 between a pulley 4 provided at the rotation center of the exhaust fan 6 and a pulley 4 fixed to the output shaft 2.

The cutter blade 3 is covered with a blade cover 7 on the approximately / side of the outer periphery. The exhaust fan 6 is rotatably supported by a fan casing 8. The fan casing 8 covers the outer periphery of the exhaust fan 6 and is supported by a side surface of the blade cover 7. In the hand cutter of this configuration, the bottom opening of the fan casing 8 serves as a dust suction port 8a, and the cutter blade 3 is rotated in the direction of the arrow while pressing the dust suction port 8a against the workpiece W to be cut. When the cutting is performed, the dust generated by the cutting is sucked and collected in the dust suction port 8a.

The collected dust is housed in a dust bag (not shown) or the like, which is connected via an attachment 9 provided on the rear side of the fan casing 8 and attached to an exhaust pipe 8b.

However, the conventional hand cutter having such a structure has a technical problem described below.

That is, in the hand cutter shown in FIG. 3, the cutter blade 3 to be rotated and the exhaust fan 6 are arranged on one side of the electric motor 1 as a rotation drive source, and the overall weight is balanced. The arrangement was difficult.

Also, in the hand cutter shown in FIG. 3, the belt 5 is wound between a pulley 4 provided at the rotation center of the exhaust fan 6 and a pulley 4 fixed to the output shaft 2 so that the exhaust fan 6 constitutes a rotary drive mechanism, but with this structure, mechanical loss increases due to friction between the belt 5 and the pulley 4, etc., the structure becomes complicated, and the number of components increases.

Although a power transmission mechanism to the exhaust fan 6 using a gear instead of the pulley 4 and the belt 5 is also provided, even if a gear is used, the structure is similar to that shown in FIG. In addition, the mechanical loss increases, the structure becomes complicated, and the number of components increases.

The present invention has been made in view of such conventional problems, and an object thereof is to provide a hand cutter which can easily obtain a weight balance. Another object of the present invention is to provide a dust suction device. An object of the present invention is to provide a hand cutter which hardly causes a mechanical transmission loss when driving a motor and has a simple structure. Disclosure of the invention

The present invention provides a hand cutter having a cutter blade and an exhaust fan that rotate in connection with a rotation shaft of a rotary drive source, wherein the cutter blade and the exhaust fan are arranged at both ends of the rotary drive source. The exhaust fan was directly connected to the rotating shaft. According to the hand cutter configured as described above, the cutter blade and the exhaust fan that are connected to the rotating shaft of the rotary drive source and the exhaust fan are arranged at both ends of the rotary drive source, so that it is easy to achieve weight balance. Become.

Further, since the exhaust fan is directly connected to the rotary shaft of the rotary drive source, there is almost no mechanical loss when transmitting the rotary drive force, the number of parts is small, and the structure is simplified.

The exhaust fan is installed in a fan casing, and communicates with a dust suction port provided in the fan casing and a blade cover covering an outer periphery of the cutter blade by a dust suction pipe, and an exhaust port of the blade cover. A dust accumulation section having a backflow prevention wall was provided in the section.

According to this configuration, when the dust in the blade cover is sucked by the rotation drive of the exhaust fan, part of the dust that could not be sucked is stored in the accumulation portion without flowing back to the blade cover side. be able to. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a fragmentary plan view showing an embodiment of a hand cutter according to the present invention.

FIG. 2 is a fragmentary side view of FIG.

FIG. 3 is a side view in a cutting state showing an example of a conventional hand cutter. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 and 2 show an embodiment of a hand cutter according to the present invention. Is shown.

The hand cutter shown in the figure has an electric motor 10 as a rotary drive source, a cutter blade 12, a rotating mechanism 13 of the cutter blade 12, and a dust suction device 14. .

The electric motor 10 has a main body 16 and a rotary shaft 18. The motor cover 20 in which the electric motor 10 is built has a left rotary shaft portion 18 of the rotary shaft 18 protruding on both sides of the main body 16. a and the right rotation shaft 18b are rotatably supported.

The member indicated by reference numeral 22 in FIG. 1 is a cable for supplying electric power to the electric motor 10. The cutter blade 12 is, for example, a disk plate obtained by sintering diamond particles. In the case of the present embodiment, the two first and second cutter blades 12 a and b are connected to the electric motor 10. On the left side of the blade, it is detachably held by the blade holder 24 so as to be parallel at a predetermined interval.

The rotating mechanism 13 of the cutter blade 12 includes a driving bevel gear 13 a fixed to the tip of the left rotating shaft 18 a, and a driven bevel gear 1 meshing with the driving bevel gear 18 a. 3b and a driven rotating shaft 13c fixed to the rotation center of the driven bevel gear 13b. The driven rotation shaft 13 c is rotatably supported by the motor cover 20, and is arranged so that the axis is orthogonal to the axis of the rotation shaft 18. The blade holder 24 includes a base sleeve 24 a fitted substantially in the middle of the driven rotary shaft 13 c, an intermediate sleeve 24 b fitted below the base sleeve 24 a, and an intermediate sleeve 2. It has a top sleeve 24c fitted below 4b, and a nut 24d screwed to the driven rotary shaft 13c.

The first power cutter blade 12a is sandwiched between the base sleeve 24a and the intermediate sleeve 24b, and the second cutter blade 12b is disposed between the intermediate sleeve 24b and the top sleeve 24c. The nut 24 d is screwed onto the driven rotary shaft 13 c, and the upper end of the nut 24 c is brought into contact with the lower end of the top sleeve 24 c, thereby forming two cutter blades 1. 2a and 2b are fixedly supported so as to be parallel to each other with an interval corresponding to the length of the intermediate sleeve 24b. More than half of the outer peripheral edges of the two cutter blades 12 a and b are covered with the blade cover 26, and a part of the lower part is exposed downward from the blade cover 26. The blade cover 26 has an internal force bar 26a and an external force bar 26b each having a shape in which a part of a circular concave cup is cut out, and a partition plate 26c. The inner cover 26a is fixed to the motor cover 20 side, the open end of the external force bar 26b is overlapped with the open end of the internal force bar 26a, and both are fixed by screws. During this fixing, the partition plate 26c is held between the covers 26a and 26b.

The partition plate 26c is provided with a through hole through which an intermediate sleeve 24b fitted to the outer periphery of the driven rotary shaft 13c can be inserted into the center portion, and a predetermined hole is provided in the blade cover 26. It is located between two cutter blades 12a and b arranged in parallel at an interval, and when the cutter blades 12a and b are driven to rotate, the airflow generated by rotation is generated. Provided to prevent mutual interference, but not required.

Further, an exhaust port 28 is provided on the outer periphery of the blade cover 26 in which the external force bars 26a and 26b are overlapped in the half-split state, as shown in detail in FIG. I have. The exhaust port portion 28 is formed by extending the outer circumference of the inner and outer force bars 26 a and 26 b into a cylindrical shape. In the case of the present embodiment, the upper portion of the circular blade cover 26 is provided. And extends in the substantially tangential direction of the circle.

Further, a backflow prevention wall 30 is formed inside the exhaust port portion 28. The backflow prevention wall 30 is formed so as to protrude along an arc of a circular blade cover 26 so as to narrow the cross section of the exhaust port 28, and the back side of the backflow prevention wall 30 holds dust. The ball is 3 1.

That is, if the backflow prevention wall 30 having such a shape is provided in the exhaust port portion 28, the exhaust fan 14a of the dust suction device 14 to be described later is rotationally driven, and is indicated by an arrow in FIG. As shown in the figure, when the dust suction air flow A is generated, the backflow prevention wall 30 is provided so as to narrow the cross section of the exhaust port 28, so that the backflow prevention wall 30 passes through the tip of the backflow prevention wall 30. When the air flow speed increases, dust can move quickly to the exhaust port 26 side. Monkey

The airflow A passing through this part bypasses the front end of the backflow prevention wall 30 and becomes turbulent due to the sudden increase in cross-sectional area on the back side of the backflow prevention wall 30. The flow velocity is reduced by colliding with the prevention wall 30 and the exhaust port 28, causing the entrained dust to fall on the back side of the backflow prevention wall 30. It becomes 1.

In other words, the backflow prevention wall 30 of the present embodiment functions as a wall that prevents the dust that has moved along with the airflow A on the back side from returning to the blade cover 26, and has a dust accumulation portion 3. It also functions as a separating wall.

On the other hand, the dust suction device 14 includes an exhaust fan 14a and a fan casing 14b. The exhaust fan 14a is formed in an annular shape, and the right rotation shaft 18b penetrates the center of the exhaust fan 14a, and a nut is screwed onto the shaft 18b to form the right rotation shaft 18b. It is directly connected and fixed.

That is, in the case of the present embodiment, the cutter blade 12 and the exhaust fan 14 b rotating in connection with the rotating shaft 18 of the rotary drive source (electric motor 10), the exhaust fan 14 b, the force S, and the rotary drive source (electric The motor 10) is disposed on both left and right sides in the left-right direction, and the exhaust fan 14 is directly connected and fixed to the rotating shaft 18 of the rotary drive source (the electric motor 10). The rotation of the rotation axis 18 is the same.

When the exhaust fan 14 is driven to rotate by the rotation shaft 18, an air flow A is generated from the center to the outer periphery. The fan casing 14b is formed so as to cover the entire outer periphery of the exhaust fan 14a, and the dust suction port 14c communicating with the center of the exhaust fan 14a and the outer periphery of the exhaust fan 14a. A connecting dust collector 14 d is provided.

The dust suction port 14 c and the exhaust port 28 are connected by a dust suction pipe 32. A dust bag (not shown) is connected to the exhaust port 14 d. The members indicated by reference numeral 34 in FIGS. 1 and 2 are rollers that roll by contacting the object W to be cut when the hand cutter is used, and the roller 36 uses the hand cutter. When the operator grips It is a handle part.

The hand cutter configured as described above supplies electric power to the electric motor 10 and is used as shown in FIG. In the band cutter of this embodiment, as shown in FIG. 2, the cutter blade 12 cuts the workpiece W while contacting the workpiece W from the lower side to the upper side. In this state, it is driven to rotate by the electric motor 10.

In such a cutting state, dust accompanying the cutting is scattered in the direction of rotation of the cutter blade 12, that is, upward from below. The dust scattered in this way is first stored in the blade cover 26 whose lower side is open.

At this time, in the blade cover 26, the exhaust fan 14a of the dust suction device 14 is driven to rotate, so that the air flows from the exhaust port 28 to the dust suction port 14c via the dust suction pipe 32. Since the airflow A is generated, the dust is sucked and moved toward the exhaust fan 14a by the airflow A, and is collected in the dust collection bag via the exhaust fan 14d.

According to the hand cutter configured as described above, both ends of the rotary drive source (electric motor 10) are connected to the rotary shaft 18 of the rotary drive source (electric motor 10) to rotate. Since the cutter blade 12 and the exhaust fan 14a are arranged, a weight balance can be easily obtained.

Also, since the exhaust fan 14a is directly connected to the rotary shaft 18 of the rotary drive source (electric motor 10), almost no mechanical loss occurs when transmitting the rotary drive force, and Fewer points and simpler structure.

Further, in the case of the present embodiment, the exhaust fan 14a is installed inside the fan casing 14b, and the exhaust port 14c provided in the fan casing 14b and the cutter blade 12 are provided. A blade cover 26 covering the outer periphery is communicated with a dust suction pipe 32, and a dust collecting portion 31 having a backflow prevention wall 30 is provided at an exhaust port 28 of the blade cover 26.

For this reason, when the dust in the blade cover 26 is sucked by the rotation drive of the exhaust fan 14 b, part of the dust that could not be sucked flows back to the blade cover 26 side It can be accommodated in the pool part 31 without any need. Industrial applicability

The hand cutter according to the present invention can easily achieve a weight balance, so that the handling performance can be improved, and the mechanical loss due to dust absorption is reduced, thereby contributing to energy saving.

Claims

The scope of the claims

1. In a hand cutter equipped with a cutter blade and an exhaust fan that rotate in connection with the rotation axis of the rotary drive source,

A hand cutter, wherein the power cutter blade and the exhaust fan are arranged at both ends of the rotary drive source, and the exhaust fan is directly connected to the rotating shaft.

2. The exhaust fan is installed in a fan casing, and communicates a dust suction port provided in the fan casing with a blade cover that covers an outer periphery of the power cutter blade through a dust suction pipe.

2. The hand cutter according to claim 1, wherein a dust accumulation portion having a backflow prevention wall is provided at an exhaust port of the blade cover.