JPH0131438Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to a hand-held cutting device, and in particular to a tool for cutting wood, rubber plates, carpets, fireproof boards, etc. by swinging a thin blade in one plane. .

Conventional technology Generally speaking, there are few examples of this type of hand-held cutting device.
There is one shown in FIG. 2, which is known from Japanese Utility Model Application Laid-Open No. 60-85903. However, recently, strong and disposable thin-bladed knives (cutter knives) have become commercially available at low cost, and cutting machines using thin-bladed knives have been developed.

As shown in Fig. 2, its structure is such that an eccentric cam 21 is fixedly mounted on an output shaft 20, and a knife-shaped thin blade 14 is attached to a swinging arm 22 that engages with the eccentric cam. In order to control the movement, an oblong hole 23 is bored approximately in the middle of the swinging arm 22 and is engaged with a shaft 24 fixed to the main body, with this shaft serving as the swinging center fulcrum. Since the action of this pivot center fulcrum is point contact between the shaft and the oval hole, wear is likely to occur, and as a result, the cutting mechanism is prone to early rattling and galling, and the oval hole is not machined. This included problems such as high manufacturing costs for parts due to the need for precision.

Problems to be Solved by the Invention The object of the invention is to provide a hand-held cutting device that eliminates the above-mentioned problems associated with the conventional structure, and eliminates the point contact action at the pivot center fulcrum. The swing arm is characterized in that the swing arm is connected to an external fulcrum of the swing arm using a lever structure.

Means for Solving the Problems That is, the present invention includes a main body having a guide plate integrally fixed to the lower part of a motor housing, a gear case, etc., and uses a deceleration device to reduce the rotation of an electric motor housed in the motor housing. an eccentric cam is provided on the output shaft, a thin blade is attached to the lower end of a swinging arm whose upper end is engaged with the eccentric cam, and one end is rotatably supported on the main body. A part of the swinging arm is rotatably supported on the other end of the lever, and the thin blade is projected downward through the elongated hole of the guide plate.

Therefore, according to the structure of the present invention, a lever crank mechanism is constructed by the swinging arm and the lever, and a toggle device is provided to eliminate point contact and to adjust the operation and force size of the thin-blade knife to be suitable for cutting. Make it something new.

Embodiments The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 shows a hand-held cutting device that is an embodiment of the present invention.
A guide plate 4 is integrally fixed to the lower part of the gear case 3.

A pinion 6 is attached to the tip of the armature shaft 5 of the electric motor incorporated in the motor housing 2, and an eccentric cam 9 is fixed to the output shaft 8 of the gear 7 that meshes with the pinion 6. The other end of the movable arm 10 is rotatably coupled to one end of a lever 11 within the rocking motion plane, and the other end of the lever 11 is rotatably coupled to a support shaft 12 fixed to the main body. . Swing arm 1
A thin-blade knife 14 is attached to the lower end of the swing arm at a predetermined angle, for example, 20 degrees, with respect to the center line of the swinging arm.
4 protrudes below the guide plate 4 through this hole.

To cut a wood board with the above-mentioned cutting device, the guide plate 4 is brought into contact with the wood, and while the thin blade is moved up and down by the mechanism driven by the electric motor, the wood board is cut by the blade part protruding below the guide plate. do.

Further, the cutting action will be explained in detail using the skeleton diagram shown in FIG. 3. The lengths of the links are respectively +<+ and -+>. The AD link is fixed, the AB link makes a crank motion centered on A, the CD link makes a swinging motion centered on D, and the BC link moves at points B and C, respectively.
It is connected with AB link and CD link in a rotational pair. Point C is the center point of the thin blade operated by this mechanism.

In FIG. 4, if crank AB rotates in the direction of the arrow, point C will move along the loop diagram in the figure, for example, although it varies depending on the link ratio.

That is, while the conventional mechanism is a swinging slider crank mechanism, the one of the present invention is a lever crank mechanism and utilizes a toggle device.

Effects of the Invention As can be seen from the above explanation, according to the configuration of the present invention, the rotation of the electric motor housed in the motor housing is transmitted to the output shaft via the reduction gear, and the output shaft is provided with an eccentric cam. A thin blade is attached to the lower end of the swinging arm whose upper end is engaged with the eccentric cam, one end is rotatably supported on the main body, and a part of the swinging arm is rotatably supported at the other end of the lever. The thin blade protrudes downward through the elongated hole in the guide plate, which eliminates point contact in the mechanism and increases durability.In addition, in order to reduce the cutting resistance caused by the thin blade, it is possible to A toggle effect can be applied at times when the load is large, allowing rational use of the motor output.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main parts showing the entire hand-held cutting device according to the present invention, FIG. 2 is a sectional view of the main parts showing the entire conventional cutting machine, FIG. 3 is a skeleton diagram explaining the cutting action, and FIG. 4 is a closed curve diagram drawn by the center point of a thin-edged knife. 1: Main body, 2: Motor housing, 3: Gear case, 4: Guide plate, 8: Output shaft, 9: Eccentric cam,
10: Swinging arm, 11: Lever, 14: Thin blade knife.

Claims (1)

[Scope of utility model registration request] The main body 1 has a guide plate 4 integrally fixed to the lower part of a motor housing 2, a gear case 3, etc., and transmits the rotation of an electric motor installed in the motor housing 2 to an output shaft 8 via a speed reduction device. An eccentric cam 9 is provided on the output shaft, a thin blade 14 is attached to the lower end of a swinging arm 10 whose upper end is engaged with the eccentric cam, and a lever 11 whose one end is rotatably supported on the main body. A hand-held cutting device characterized in that a part of the swinging arm 10 is rotatably supported at the end thereof, and the thin-blade knife 14 projects downward through a long hole in the guide plate 4.