JPH09300339A - Electrically driven cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent cut chips from being scattered to a rear side operator side by a method wherein subtle control of a cutter main body can be executed by widening a distance between a switch operating grip part of a handle and a grip part of an auxiliary handle. SOLUTION: A switch operating grip part of a handle 19 is positioned near a most rear end of a cutter main body 1, and a grip part of an auxiliary handle 23 is arranged at a shortest position tolerable from a standpoint of safety from a maximum aperture position 25 of a protective cover 15. Thereby, a distance between the switch operating grip part of the handle 19 and the grip part of the auxiliary handle 23 is widened. Further, by forming a dust guard 24 of a rubber elastic component, a size having an interception effect can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric cutter for cutting a stone material such as concrete or a steel material with a tip tool such as a diamond wheel or a cutting grindstone. Japanese Patent Application Laid-Open No. 7-171822 previously filed by the applicant of the present invention. It is an improved version.

[0002]

2. Description of the Related Art In the above-mentioned application, as shown in FIG. 9, an electric motor in which a handle 19, a tip tool 12, and a grip portion of an auxiliary handle 23 are positioned on the axis of an electric motor 3 (not shown) in the cutter body 1. Suggested a cutter.

[0003]

The electric cutter has a handle 19 incorporating a switch 20 and an auxiliary handle 23.
Since the grip portion of the cutter body 1 is arranged above the center of gravity of the cutter body 1, it has the advantage of good stability in the state of holding the cutter body 1, but the handle 19
There is a problem that the distance c between the grip portion of the auxiliary handle 23 and the grip portion is smaller than the shoulder width of the operator (about 20 cm), and it is difficult to delicately control the cutter body 1 when cutting. In the cutting of stone materials such as concrete, there is a problem that the cutting chips are scattered on the cutter body 1 side by the rotation of the tip tool 12 and hit the operator. With respect to this problem in some engine cutters, as shown in FIG. 8, a shield plate 35 made of an iron plate or the like that shields cutting chips is provided below the auxiliary handle 23. However, in this structure, since the lower end of the auxiliary handle 23 is used as a stand when the cutter body 1 is placed on the ground, the size of the blocking plate 35 is naturally restricted, and a sufficient blocking effect cannot be achieved. there were. Further, since the blocking plate 35 is a flat surface and is close to a right angle with respect to the scattered cutting chips, there is a problem that the cutting chips bounce upward and hit the worker. In order to solve this, in the electric cutter, the dust collecting hood 37 made of an elastic body is provided at the lower end of the auxiliary handle 23 so that the dust collecting machine can be connected and used.
However, there is a problem in that operability is difficult due to the large size.

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and provide an electric cutter having good operability.

[0005]

In order to achieve the above object, the present invention provides a switch operating grip portion of a handle near the rear end of a cutter body and a grip portion of an auxiliary handle for safety from an opening of a protective cover. It is located at the shortest allowable position, and is configured to widen the distance between the switch operation grip of the handle and the auxiliary handle. Further, a dust guard formed by an elastic member is provided between the tip tool and the cutter body in order to block cutting chips scattered to the cutter body side. Furthermore, a dust collecting nozzle whose discharge side opening can be connected to the dust collector is attached to one end of the opening of the protective cover so that the suction side opening faces the circumference of the tip tool, and when the dust collector is not used, an air layer is formed on the bottom. The discharge side opening was closed with a nozzle cap fitted with an iron plate.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION FIG. 1 showing an embodiment of the present invention.
~ It demonstrates with reference to FIG. An inner cover 4 is attached to the front surface of a cutter body 1 having a built-in electric motor 3 having a first speed change gear 2 mounted on its shaft end, and a gear cover 5 having a portion extending long forward is attached to the front surface of the inner cover 4. ing. A second transmission gear 6 is housed on the cutter body 1 side of the gear cover 5, a second transmission gear 6 is mounted on the rear end thereof, and a connecting shaft 7 extending forwardly is housed in a long extending portion of the gear cover 5. Further, in front of the gear cover 5, a first bevel gear 8 mounted on the tip of the connecting shaft 7, a second bevel gear 11 meshing with the first bevel gear 8, and the like are housed. A second bevel gear 11 is provided below the tip of the gear cover 5 together with the gear cover 5.
A bearing holder 9 accommodating the like is mounted. The second bevel gear 11 is mounted, and the tip of the spindle 10 supported by the gear cover 5 and the bearing holder 9 is mounted with a tip tool 12 composed of a diamond wheel, a cutting grindstone, etc. by a bolt 14 via a washer 13. There is. The protective cover 15 covering the tip tool 12 is the holder 1
It is rotatably attached to the bearing holder 9 by means of a set screw 16 via 7, and is fixed at an arbitrary rotational position by a set screw 18. A dust collecting nozzle 2 for collecting cutting chips at one end of the opening of the protective cover 15.
6, the suction side opening of the dust collecting nozzle 26 faces the circumference of the tip tool 12, and the discharge side opening is connected to a dust collector (not shown) via the dust collecting hose 32 shown in FIG. When not connected to the dust collector, the discharge side opening of the dust collecting nozzle 26 is closed by the nozzle cap 25. The handle 19 including the power switch 20 is attached to the cutter body 1 so as to be positioned on the axis of the electric motor 3 together with the tip tool 12. An auxiliary handle 23 is attached to the gear cover 5 via a bolt 21 and a set screw 22. The auxiliary handle 23 extends laterally beyond the lateral width of the cutter body 1 so that its grip is located on the axis of the electric motor 3. A dust guard 24 for blocking cutting chips generated during cutting is attached to the bottom of the cutter body 1 by an auxiliary handle 23 and a bolt 21.

As shown in FIG. 1, the switch operating grip of a handle 19 having a built-in power switch 20 is attached to the cutter body 1.
A trigger for operating the power switch 20 is provided at the rear of the handle 19 so as to be located near the rear end of the handle. Further, the grip portion of the auxiliary handle 23 is at the shortest position allowed for safety from the maximum opening position 27 of the protective cover 15, that is, the distance a at which the finger does not touch the tip tool 12 even if the finger is extended with the grip portion of the auxiliary handle 23 held. (About 15 cm).
The maximum opening position 27 of the protective cover 15 is a position indicated by a broken line of the protective cover 15 when cutting at the tip portion (right end portion in FIG. 1) of the tip tool 12. As a result of such a configuration, the distance b between the switch operation grip of the handle 19 and the grip of the auxiliary handle 23 can be set to a value around the shoulder width (about 30 cm) of the operator who has the best operability. The delicate control of the cutter body 1 at the time of cutting becomes possible, and the operability can be improved.

The dust guard 24 is made of rubber which is an elastic member. Therefore, even if the cutter body 1 is placed on the ground, the dust guard 24 is elastically deformed freely, so that it can be formed in a size capable of sufficiently blocking the cutting chips 28. Further, as shown in FIG. 4, since the surface on which the cutting chips 28 come into contact is formed into a convex curved surface, the cutting chips 28 can be rebounded downward and can be largely prevented from scattering to the operator side.
FIG. 5 shows high-temperature cutting chips 28 generated when cutting a steel material.
Another embodiment of the dust guard 24 that can be used, however, is a synthetic resin sheet such as a fluororesin sheet 29 having heat resistance and elasticity on the surface on which the cutting chips 28 come into contact.
Is glued. Therefore, the dust guard 24 is not burned even by the high temperature cutting chips 28, and the elasticity can be maintained. In addition, the fluorocarbon resin sheet 29 is attached to the dust guard 2
4 When bonded by integral baking at the time of molding, rubber generally has a higher heat shrinkage rate than fluororesin, so the dust guard 24 shrinks greatly after molding and a convex curved surface is automatically formed. The effect that it can be easily manufactured can also be obtained.

The dust collecting nozzle 26 is provided at one end of the opening of the protective cover 15, and the suction side opening is at the tip tool 12.
Since it is opposed to the circumference of, the cutting chips 28 can smoothly flow to the dust collecting hose 32 via the dust collecting nozzle 26, and high dust collecting efficiency can be obtained and the dust collecting structure can be made compact. As a result, the operability of the electric cutter itself can be improved. When the nozzle cap 25 is made of heat-resistant rubber having a low thermal conductivity, such as fluororubber, the risk of damage to the cutting chips 28 at high temperatures is reduced. However, since fluororubber is very expensive, there is a cost problem. FIG. 7 shows an example of a rubber cap 25 that can be formed of inexpensive rubber having low heat resistance. An iron plate 33 having high heat resistance is provided on the bottom through an air layer 34, and high temperature cutting chips 28 are The nozzle cap 25 is designed so as not to directly hit the nozzle cap 25. Further, even if the iron plate 33 is heated to a high temperature by a large amount of high temperature cutting chips 28, the air layer 34
Thus, there is an advantage that a heat insulating effect is obtained, the nozzle cap 25 is not damaged, and the nozzle cap 25 can be manufactured at low cost.

[0010]

As described above, according to the present invention, the distance between the handle with a built-in switch and the auxiliary handle can be made the shoulder width of the operator who has the best operability. Control becomes possible.
Further, since the dust guard is formed by the elastic member, the dust guard can be formed large and the cutting chips scattered to the cutter body side, that is, the worker side can be effectively blocked. Become.

Further, a dust collecting nozzle is provided at one end of the opening of the protective cover so that the suction side opening faces the circumference of the tip tool so that cutting chips can be smoothly guided.
The dust collection efficiency can be improved, the dust collection structure can be made compact, and the operability of the electric cutter can be further improved.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of an electric cutter of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

FIG. 3 is a front view of FIG.

FIG. 4 is a side view showing a cutting state by the electric cutter of FIG. 1.

FIG. 5 is a side view of a main part showing another embodiment of the dust guard.

FIG. 6 is a side view showing a state in which the dust collector is connected and disconnected.

FIG. 7 is a cross-sectional view of main parts showing another embodiment of the dust collection nozzle.

FIG. 8 is a side view showing a cutting state by a conventional engine cutter.

FIG. 9 is a side view showing a conventional electric cutter.

[Explanation of symbols]

1 is a cutter body, 2 and 6 are speed change gears, 3 is an electric motor, 7 is a connecting shaft, 8 and 11 are bevel gears, 10 is a spindle, 12 is a tip tool, 15 is a protective cover, 19 is a handle, 20 is a power switch , 23 is an auxiliary handle, 24 is a dust guard, 25 is a nozzle cap, 26 is a dust collecting nozzle, 28 is cutting chips, 29 is a fluororesin sheet, 32 is a dust collecting hose, 33 is an iron plate, and 34 is an air layer. .

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takashi Odajima 1060 Takeda, Hitachinaka City, Ibaraki Prefecture Hitachi Koki Co., Ltd.

Claims (8)

[Claims] 1. A cutter body having a built-in electric motor, a handle with a built-in switch, which extends along the axial direction of the electric motor and is attached to the cutter body, and a handle provided in a direction perpendicular to the electric motor shaft to change the rotation of the electric motor. A plurality of speed change gears, an end portion on the electric motor side and the other end fixed to one of the speed change gears and the first bevel gear, respectively, and a connecting shaft extending along the axial direction of the electric motor,
A spindle fixed to a second bevel gear that meshes with the first bevel gear, a tip tool such as a cutting grindstone or a diamond wheel attached to the spindle, a protective cover for covering the tip tool, and a tip tool end of the cutter body. In the electric cutter with the auxiliary handle, the switch operation grip of the handle is located near the rear end of the cutter body, and the grip of the auxiliary handle is located at the shortest position allowed for safety from the protective cover opening.
An electric cutter characterized by widening the distance between the switch operation handle of the handle and the handle of the auxiliary handle. 2. A cutter body having a built-in electric motor, a handle having a built-in switch, which extends along the axial direction of the electric motor and is attached to the cutter main body, and is provided in a direction perpendicular to the electric motor shaft to change the rotation of the electric motor. A plurality of speed change gears, an end portion on the electric motor side and the other end fixed to one of the speed change gears and the first bevel gear, respectively, and a connecting shaft extending along the axial direction of the electric motor,
A spindle fixed to a second bevel gear that meshes with the first bevel gear, a tip tool such as a cutting grindstone or a diamond wheel attached to the spindle, a protective cover for covering the tip tool, and a tip tool end of the cutter body. In an electric cutter equipped with an auxiliary handle, a dust guard that blocks cutting chips scattered on the cutter body side is formed by an elastic member, and the dust guard is attached to the tip tool end of the cutter body. Cutter. 3. The electric cutter according to claim 2, wherein a surface of the dust guard against which the cutting chips come into contact is formed into a convex curved surface. 4. The electric cutter according to claim 2, wherein a heat-resistant elastic member having a heat shrinkage ratio smaller than that of an elastic member forming the dust guard is bonded to a surface of the dust guard on which the cutting chips come into contact. . 5. The electric cutter according to claim 4, wherein the heat-resistant elastic member is adhered to the dust guard by baking. 6. The electric cutter according to claim 4, wherein the dust guard is formed of rubber and the heat-resistant elastic member is formed of a fluororesin sheet. 7. A cutter main body having a built-in electric motor, a handle having a built-in switch, which extends along the axial direction of the electric motor and is attached to the cutter main body, and is provided in a direction perpendicular to the electric motor shaft for changing the rotation of the electric motor. A plurality of speed change gears, an end portion on the electric motor side and the other end fixed to one of the speed change gears and the first bevel gear, respectively, and a connecting shaft extending along the axial direction of the electric motor,
A spindle fixed to a second bevel gear that meshes with the first bevel gear, a tip tool such as a cutting grindstone or a diamond wheel attached to the spindle, a protective cover for covering the tip tool, and a tip tool end of the cutter body. An electric cutter having an auxiliary handle, wherein a dust collecting nozzle having a suction side opening facing the circumference of the tip tool is attached to one end of the opening of the protective cover. 8. The electric cutter according to claim 7, wherein the discharge side opening of the dust collecting nozzle is closed by a nozzle cap having an iron plate attached to the bottom through an air layer.