JP2002079414A - Portable motor-driven cutting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable motor-driven cutting device capable of restraining a saw blade from breaking or damaging floor, etc., because of the sudden start of an electric motor for some reason or other with a safety cover left not returning to a fixed position and the saw blade left exposed. SOLUTION: The restriction means 3 of a restrict the safety cover 1 is made to abut on the lower end of an operation lever 2, and the operation lever 2 is provided in the safety lever 1 such that the lever 2 can be turned a specified quantity, and a start controlling means 4 is provided to permit the electric motor to start while the lever 2 is turned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable electric cutting machine provided with a safety cover (hereinafter, referred to as a portable electric circular saw).

[0002]

2. Description of the Related Art An example of a conventional portable electric circular saw will be described with reference to FIGS.

As shown in FIG. 1, the portable electric circular saw includes a saw blade 5 driven to rotate by an electric motor 15, a main body 13 having a built-in electric motor 15 and rotatably holding the saw blade 5, and a saw blade 5 from the lower end. The base 9 is provided below the main body 13 so that the protruding portion 5 protrudes, and the saw blade 5 is shaped so as to cover part of the outer periphery thereof. Safety cover 1 and body 13
And a stopper 17 which is a restricting means for restricting the position of the safety cover 1 below the base 9 by contacting the safety cover 1.

As shown in FIG. 5, power from an electric motor 15 is transmitted through a gear 14 fixed to a rotating shaft 6 of the saw blade 5.
The rotating shaft 6 is rotatably supported by a rolling bearing 7, and the rolling bearing 7
Is held by a rolling bearing holding portion 8 fixed in the main body 13.

The above-mentioned safety cover 1 is provided on the outer periphery of the rolling bearing holding portion 8 so as to be rotatable on the bearing holding portion 8.
The position of the safety cover 1 on the lower side of the base 9 is regulated by a stopper 17 and is stationary at a predetermined position.

In the portable electric circular saw described above, the saw blade 5 is driven to rotate by turning on a start switch (not shown), and the main body 13 is pushed into the material to be cut in the direction of the arrow as shown in FIG. Pressed against the material to be cut,
By rotating the safety cover 1 upwardly of the base 9 against the urging force of the spring 16, the saw blade 5 is exposed to cut the workpiece.

[0007] In addition, as shown in FIG. 7, in a case where a cut is made at a place other than the end face of the material to be cut, an operation lever 2 provided at the upper end of the safety cover 1 is provided.
The operation is performed by manually rotating the safety cover 1 to expose the saw blade 5 below the base 9.

When the cutting operation is completed and the main body 13 is separated from the material to be cut, the safety cover 1 is rotated downward by the urging force of the spring 16 until it comes into contact with the stopper 17, and the saw blade 5 located below the base 9 is rotated. Cover.

[0009]

In the portable electric circular saw as described above, the safety cover 1 is required at the end of the cutting operation.
Is rotated downward by the urging force of the spring 16 to cover the saw blade 5 below the base 9, so that the saw blade 5 is not exposed before the start of normal work. Safety cover 1 is stopper 17
Even if the saw blade 5 is exposed without rotating until it comes into contact with the motor, if the start switch is turned on, the electric motor 15 starts and the saw blade 5 rotates. If the start switch is suddenly turned on, the saw blade 5 may be damaged or the floor or the like may be damaged.

An object of the present invention is to provide a portable electric circular saw capable of solving the above-mentioned disadvantages and reducing the life of the saw blade, damaging the floor and the like. is there.

[0011]

SUMMARY OF THE INVENTION The object of the present invention is to provide a safety cover in which a contact portion with a regulating means is a lower end of an operating lever, the operating lever is provided on the safety lever so as to be rotatable by a predetermined amount, and the operating lever is in a rotating state. This can be achieved by providing a start control unit that allows the start of the electric motor.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a portable electric circular saw according to the present invention will be described with reference to FIGS. FIG. 1 is a front view showing one embodiment of the portable electric circular saw of the present invention, FIG. 2 is an enlarged view of a part A of FIG. 1 showing one operation state of an operation lever constituting the portable electric circular saw of the present invention, FIG. FIG. 2 is an enlarged view of a portion A in FIG. 1 showing another operation state of the operation lever.

As shown in FIG. 1, an operation lever 2 is provided at the upper end of the safety lever 1. The main body 13 is located below the base 9 of the safety cover 1 at a position where it can contact the lower end of the operation lever 2. A stopper 3 is provided as a restricting means for restricting the rotation of the motor. The safety cover 1 is constantly biased by a spring 16 so as to rotate below the base 9. When the lower end of the operation lever 2 comes into contact with the stopper 3, the rotation of the safety cover 1 is restricted as described above, and 9 to cover the saw blade 5 below.

The operating lever 2 is attached to the safety cover 1 by a pin 2a, and is rotatable about the pin 2a by a predetermined amount (a range between a solid line and a dotted line shown in FIGS. 2 and 3). A start control switch 4 for controlling the start state of the electric motor is connected to the operation lever 2, and the start control switch 4 is in a state in which the operation lever 2 is rotated upward about the pin 2a as shown in FIG. And turns on when the operation lever 2 is rotating downward with the pin 2a as a fulcrum, as shown in FIG. The electric motor and the power supply are electrically disconnected from each other so that the electric motor does not start even if a start switch (not shown) is turned on.

In the portable electric circular saw of this embodiment, if the start switch is turned on when the start control switch 4 is in the ON state and the motor is started, then the start control switch 4 is turned off. Also, the electric connection between the electric motor and the power supply is maintained while the start switch is turned on.

With the above-described configuration, as shown in FIG.
When the lower end of the operation lever 2 is in contact with the stopper 3 and the rotation of the safety cover 1 is restricted, the operation lever 2 is moved to the pin 2a as shown in FIG. Is rotated upward with the fulcrum as a fulcrum, whereby the start control switch 4 is turned on. Therefore, when the start switch is turned on, the electric motor can be started and the cutting operation can be performed.

On the other hand, when the safety cover 1 is pivoted upwardly of the base 9 against the spring 16 for some reason, the operating lever 2 supports the pin 2a by its own weight as shown in FIG. As the start control switch 4 is OFF, the electric motor does not start even if the start switch is turned on, so that the saw is suddenly started with the 5 exposed. By turning on the switch, the saw blade 5
Can be prevented from being damaged, or damage to a mating material such as a floor can be suppressed.

Further, even in the case where a cut is made in a place other than the end face of the material to be cut as shown in FIG. 7, the safety lever 1 is turned upward through the operation lever 2 through the operation lever 2. At this time, push the operating lever 2
When the motor is rotated upward with the fulcrum as a fulcrum, the start-up control switch 4 can be turned on to allow the start-up of the motor, and the motor can be started up by turning on the start-up switch.

In the above embodiment, the operation lever 2 is rotated downward by its own weight when the lower end of the operation lever 2 is not in contact with the stopper 3. However, the operation lever 2 is always rotated downward. A configuration may be provided in which an urging means (not shown) for urging is provided. In such a configuration, it is necessary to set the urging force of the urging means for urging the operation lever 2 to be smaller than the urging force of the spring 16 as the urging means for urging the safety cover 1. .

In principle, electric power is supplied to the motor only when the switch 4 is ON. When some external force is applied and the switch 4 is turned off, the power supply to the electric motor is cut off. However, once the motor is driven, switch 4
Is turned off, the power supply is not interrupted. When the motor stops, power transmission to the motor is turned off again by the switch 4.
N is limited.

In the electric cutting machine having the above-described power transmission control function, the electric motor cannot be started when the protective cover 1 is not at a predetermined position, that is, when the operating lever 2 is separated from the stopper 3 and the cutting tool 5 is exposed. Will be. Conversely, when the protective cover 1 is at a predetermined position, the electric motor can be started. Once the motor starts,
Even if the protective cover 1 is brought into contact with the material and turned to turn off the switch 4 of the lever portion, the power is not cut off.
The cutting operation can be continued by exposing the cutting tool 5.

Further, even when the operating lever 2 is directly pulled up by hand, the switch 4 is turned on, so that the electric motor can be started. In other words, the above-described cutting operation performed by directly opening the protective cover 1 can be performed without any problem.

[0023]

According to the present invention, the portion of the safety cover that comes into contact with the regulating means is the lower end of the operation lever, and the operation lever is provided on the safety lever so as to be rotatable by a predetermined amount. Providing a portable electric circular saw capable of suppressing a reduction in the life of a saw blade, damage to a floor or the like by providing a start control unit that allows starting of an electric motor. become able to.

[Brief description of the drawings]

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

FIG. 2 is an enlarged view of a part A of FIG. 1 showing one operation state of an operation lever.

FIG. 3 is an enlarged view of a portion A in FIG. 1 showing another operation state of the operation lever.

FIG. 4 is a front view showing an example of a conventional portable electric circular saw.

FIG. 5 is a sectional side view showing an example of a conventional portable electric circular saw.

FIG. 6 is a perspective view showing one working state of a conventional portable electric circular saw.

FIG. 7 is a perspective view showing one working state of a conventional portable electric circular saw.

[Explanation of symbols]

1 is a safety cover, 2 is an operation lever, 2a is a pin, 3 is a stopper, 4 is a start control switch, 5 is a saw blade,
9 is a base, 15 is an electric motor, and 16 is a spring.

Claims (2)

[Claims] 1. A saw blade rotatably driven by an electric motor, a main body containing the electric motor and rotatably holding the saw blade, and a lower part of the main body provided so that the saw blade protrudes from a lower end. A base, a saw cover provided on the main body and configured to cover substantially the upper half of the outer periphery of the saw blade located on the upper surface of the base, and a shape configured to cover a part of the outer periphery of the saw blade; A safety cover biased to be located on the lower side, an operation lever provided on a part of the safety cover, located above the base, provided on the main body, and abutting on the safety cover, A portable electric cutting machine having regulating means for regulating a base lower side position of a safety cover, wherein a portion of the safety cover contacting the regulating means is The operating lever is provided at the lower end, and the operating lever is provided on the safety lever so as to be rotatable by a predetermined amount, and a starting control means is provided for allowing the starting of the electric motor when the operating lever is in a rotating state. Portable electric cutting machine. 2. The method according to claim 1, wherein the activation control means allows the electric motor to be activated when the operation lever rotates upward, and always urges the operation lever to rotate downward. 2. The portable electric cutting machine according to claim 1, wherein a biasing means is provided, and a biasing force of the biasing means is set smaller than a biasing force of the biasing means for biasing the safety lever.