JP2000254916A - Hand cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hand cutter whose wt. is easily balanced. SOLUTION: A hand cutter has an electrically-operated motor 10, a cutter blade 12, a rotating mechanism part 13 for the cutter blade 12 and a dirt pickup device 14. The cutter blade 12 is removably held by a blade holder 24 on the left side of the electrically-operated motor 10. The rotating mechanism part 13 is provided with a driving bevel gear 13a fixed on the apex of a left rotating shaft part 18a and a follower bevel gear 13b mating with the driving bevel gear 13a and a follower rotating shaft 13c fixed at the rotational center of the follower bevel gear 13b. The dirt pickup device 14 is provided with an exhaust fan 14a and a fan casing 14b. The cutter blade 12 and the exhaust fan 14b rotating by linking with the rotating shaft 18 of a rotational driving source (the electrically-operated motor 10) are arranged both end sides in the left and right directions and the exhaust fan 14 is directly connected with the rotating shaft 18 of the rotational driving source (the electrically-operated motor 10).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hand cutter, and more particularly, to an improvement in a dust absorbing structure of a hand cutter.

[0002]

2. Description of the Related Art Hand cutters used for hanging works such as concrete and stone materials are used, for example, when forming a cut of about several centimeters at a boundary portion of hanging work.

[0003] When a notch is formed by a hand cutter, dust is generated along with cutting of concrete or the like by a cutter blade, and there is a concern that surrounding equipment may be contaminated.

[0004] Therefore, a dust suction device is conventionally attached to this type of cutter, and a conventional example of a hand cutter equipped with a dust suction device is shown in FIG. The hand cutter shown in FIG. 1 includes an electric motor 1 serving as a rotary drive source, a cutter blade 3 detachably attached to an output shaft 2 of the motor 1, and a dust suction provided at a rear side of the cutter blade 3. And an exhaust fan 6.

[0005] Between the output shaft 2 and the cutter blade 3, a gear box 2a for changing the direction of rotation is interposed. The exhaust fan 6 is driven to rotate by winding a belt 5 between a pulley 4 provided at the center of rotation of the exhaust fan 6 and a pulley 4 fixed to the output shaft 2.

[0006] The cutter blade 3 has approximately 2 /
The three sides are covered by the blade cover 7. The exhaust fan 6 is rotatably supported by the fan casing 8, and the fan casing 8 covers the outer periphery of the exhaust fan 6,
It is supported on the side surface of the blade cover 7.

In the hand cutter of this construction, the bottom opening of the fan casing 8 serves as a dust suction port 8a.
When cutting is performed by rotating the cutter blade 3 in the direction of the arrow while pressing the dust suction port 8a against the object to be cut W, dust generated by the cutting is sucked and collected in the dust suction port 8a.

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

[0009] However, the conventional hand cutter having such a structure has the following technical problems.

[0010]

That is, in the hand cutter shown in FIG. 3, the electric motor 1 which is a rotary drive source is used.
The cutter blade 3 to be rotated and the exhaust fan 6 are arranged on one side of the device, so that the overall weight balance is hardly obtained.

In the hand cutter shown in FIG. 3,
A pulley 4 provided at the center of rotation of an exhaust fan 6;
A belt 5 is wound between the pulley 4 and the pulley 4, which is fixed to the exhaust fan 6.
In 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 in place of the pulley 4 and the belt 5 is provided, even if a gear is used, the structure shown in FIG. As with, 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 of the present invention is to provide a hand cutter in which a weight balance can be easily obtained.

Another object of the present invention is to provide a hand cutter which hardly causes a mechanical transmission loss when driving a dust suction device and has a simple structure.

[0015]

In order to achieve the above object, the present invention relates to a hand cutter having a cutter blade rotating in connection with a rotating shaft of a rotary drive source and an exhaust fan. Exhaust fans were arranged at both ends of the rotary drive source, and the exhaust fan was directly connected to the rotating shaft. According to the hand cutter configured as described above, since the cutter blade and the exhaust fan that are connected to the rotating shaft of the rotary drive source and rotate are arranged at both ends of the rotary drive source, it is easy to achieve weight balance. . Further, since the exhaust fan is directly connected to the rotary shaft of the rotary drive source, almost no mechanical loss occurs 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, communicates a dust suction port provided in the fan casing with a blade cover that covers an outer periphery of the cutter blade by a dust suction pipe, and is connected to an exhaust port of the blade cover. And a dust collecting portion having a backflow preventing wall. According to this configuration, when the dust in the blade cover is sucked by the rotation of the exhaust fan, part of the dust that could not be sucked can be stored in the accumulation portion without flowing back to the blade cover side. .

[0016]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
1 and 2 show an embodiment of the hand cutter according to the present invention.

The hand cutter shown in FIG. 1 includes an electric motor 10 as a rotary drive source and a cutter blade 12.
, A rotation mechanism 13 of the cutter blade 12, and a dust suction device 14.

The electric motor 10 includes a main body 16 and a rotating shaft 18.
And a motor cover 20 in which the
In addition, a left rotating shaft portion 18a and a right rotating shaft portion 18b of a rotating shaft 18 protruding from both sides of the main body 16 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.
The second cutter blades 12a and 12b are detachably held on the blade holder 24 so as to be parallel at a predetermined interval on the left side of the electric motor 10.

The rotation mechanism 13 of the cutter blade 12
Is the driving bevel gear 1 fixed to the tip of the left rotating shaft portion 18a.
3a and the driven bevel gear 1 meshing with the driving bevel gear 18a
3b, and a driven rotation shaft 13c fixed to the rotation center of the driven bevel gear 13b.

The driven rotation shaft 13c 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 24a fitted substantially at the center of the driven rotary shaft 13c, an intermediate sleeve 24b fitted below the base sleeve 24a, and a top sleeve fitted below the intermediate sleeve 24b. 24c, and a nut 24d screwed to the driven rotation shaft 13c.

The first cutter blade 12a is sandwiched between the base sleeve 24a and the intermediate sleeve 24b,
The second cutter blade 12b is sandwiched between the intermediate sleeve 24b and the top sleeve 24c, and has a nut 24d.
Is screwed to the driven rotation shaft 13c, and the upper end side of the nut 24c is brought into contact with the lower end of the top sleeve 24c. Fixedly supported so as to be parallel.

The two cutter blades 12a and 12b have at least half of their outer peripheral edges covered by the blade cover 26, and a lower part thereof is exposed downward from the blade cover 26.

The blade cover 26 has an inner cover 26a and an outer cover 26b, each of which is formed by cutting out a part of a circular concave cup, and a partition plate 26c. The inner cover 26a is fixed to the motor cover 20 side, the opening end of the outer cover 26b is overlapped with the opening end of the inner cover 26a, and both are fixed by screws. Partition plate 2 between 26b
6c is clamped.

The partition plate 26c has a through hole through which the intermediate sleeve 24b fitted on the outer periphery of the driven rotary shaft 13c can be inserted.
6 is located between two cutter blades 12a and 12b arranged in parallel at a predetermined interval, and air generated as the cutter blades 12a and 12b are driven to rotate. This is provided to prevent the flows from interfering with each other, but is not always necessary.

The inner and outer covers 26a, 26
2b is superimposed on the outer periphery of the blade cover 26 on which
An exhaust port 28 is provided as shown in FIG.

The exhaust port 28 has inner and outer covers 26a,
The outer periphery of the cylindrical blade cover 26b is extended in a cylindrical shape. In the case of the present embodiment, the outer periphery of the circular blade cover 26b is provided on the upper side of the circular blade cover 26 and extends in a substantially tangential direction of the circular shape.

Further, a backflow prevention wall 30 is formed inside the exhaust port 28. This backflow prevention wall 30
Is formed so as to protrude along the arc of the circular blade cover 26 so as to narrow the cross section of the exhaust port portion 28, and the back side of the backflow prevention wall 30 is a dust accumulation portion 31.

That is, the backflow prevention wall 3 having such a shape is used.
If 0 is provided in the exhaust port portion 28, when the exhaust fan 14a of the dust suction device 14 described below is rotationally driven to generate the dust suction air flow A as indicated by an arrow in FIG. ,
Since the backflow preventing wall 30 is provided so as to narrow the cross section of the exhaust port portion 28, the flow velocity of the air flow increases when passing through the tip of the backflow preventing wall 30, and the dust moves quickly to the exhaust port portion 26 side. Can be done.

The airflow A passing through this portion so as to bypass the front end side of the backflow prevention wall 30 is
A sudden increase in the cross-sectional area on the back side of the turbulent flow causes a turbulent flow. The turbulent flow collides with the prevention wall 30 and the exhaust port portion 28, and the flow velocity decreases. To the back side of the
It becomes 1.

That is, the backflow prevention wall 30 of the present embodiment functions as a wall for preventing the dust moved along with the air flow A on the back side from returning to the blade cover 26 side, and also forms the dust accumulation portion 31. It also functions as a separating wall.

On the other hand, the dust suction device 14 is provided with 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 is directly connected and fixed to the right rotation shaft 18b by screwing a nut to the shaft 18b.

That is, in the case of the present embodiment, the cutter blade 12 and the exhaust fan 14b which rotate in connection with the rotary shaft 18 of the rotary drive source (electric motor 10) are connected to the rotary drive source (electric motor 10). The exhaust fan 1 is disposed on both ends in the left-right direction, and is attached to a rotation shaft 18 of a rotation drive source (electric motor 10).
4 is directly connected and fixed, and the exhaust fan 14 rotates in the same manner as the rotating shaft 18 of the electric motor 10.

When the exhaust fan 14 is driven to rotate by the rotating shaft 18, an air flow A from the center to the outer periphery is generated. The fan casing 14b includes an exhaust fan 14a
Is formed so as to cover the entire outer periphery of the exhaust fan 14.
a suction port 14c communicating with the center of the exhaust fan 14a;
And a dust discharge port 14d connected to the outer periphery of each of them.

The dust suction port 14c and the exhaust port 28 are connected to each other by a dust suction pipe 32. A dust bag (not shown) is connected to the dust outlet 14d. 1 and 2, reference numeral 3
The member denoted by reference numeral 4 is a roller which rolls by contacting the object W to be cut when the hand cutter is used.
Is a handle portion that an operator grips when using the hand cutter.

The hand cutter constructed as above is
The electric motor 10 is supplied with electric power and used as shown in FIG. In the band cutter of the present embodiment, as shown in FIG. 2, the cutter blade 12 cuts the workpiece W while contacting the workpiece W upward from below. It is rotationally driven by the electric motor 10.

In such a cutting state, the dust accompanying the cutting is rotated in the direction of rotation of the cutter blade 12, ie,
It flies upward from below. The dust scattered in this manner is, first, the blade cover 26 having an open lower side.
Housed within.

At this time, the exhaust fan 14a of the dust suction device 14 is rotationally driven into the blade cover 26, so that the exhaust fan 28 is moved from the exhaust port 28 through the dust suction pipe 32 to the dust suction port 14c.
Is generated, the air flow A is generated.
As a result, the dust is sucked and moved toward the exhaust fan 14a, and is collected in the dust bag via the dust outlet 14d.

According to the hand cutter constructed as described above, the cutter which is connected to the rotating shaft 18 of the rotary drive source (electric motor 10) is provided at both ends of the rotary drive source (electric motor 10). Since the blade 12 and the exhaust fan 14a are arranged, it is easy to balance the weight.

The exhaust fan 14a is a rotary drive source.
Since it is directly connected to the rotating shaft 18 of the (electric motor 10),
There is almost no mechanical loss when transmitting the rotational driving force, the number of parts is small, and the structure is simplified.

Further, in the case of the present embodiment, the exhaust fan 14a is installed inside the fan casing 14b,
A dust suction port 14c provided in the fan casing 14b;
Blade cover 26 covering the outer periphery of cutter blade 12
Through a dust suction pipe 32 and the blade cover 26
A dust collecting portion 31 having a backflow preventing wall 30 is provided in the exhaust port portion 28 of FIG.

For this reason, when the dust in the blade cover 26 is sucked by the rotation of the exhaust fan 14b, a part of the dust that could not be sucked does not flow back to the blade cover 26, but remains in the accumulation portion 31. Can be accommodated.

[0043]

As described above in detail in the embodiments,
ADVANTAGE OF THE INVENTION Since the hand cutter of this invention can easily take a weight balance, it can aim at the improvement of handling performance, and also can contribute to energy saving since the mechanical loss accompanying dust absorption decreases.

[0044]

[Brief description of the drawings]

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 a main part of FIG.

FIG. 3 is a side view in a cutting state showing an example of a conventional hand cutter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Electric motor 12 Cutter blade 14 Dust-absorbing device 16 Main body 18 Rotating shaft 20 Motor cover 24 Blade holder

Claims (2)

[Claims] 1. 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, A hand cutter wherein the exhaust fan is directly connected to a rotating shaft. 2. The exhaust fan is installed in a fan casing and communicates a dust cover provided in the fan casing with a blade cover covering an outer periphery of the cutter blade by a dust suction pipe. 2. The hand cutter according to claim 1, wherein a dust collecting portion having a backflow prevention wall is provided at the exhaust port portion.