JPH06254779A - Switch mechanism for power tool - Google Patents

Abstract

PURPOSE:To To improve operability of a switch lever and a regulating member by preventing the occurrence of malfunction through separation of the switch lever from the regulating member for a forcing amount thereof. CONSTITUTION:A gear shifting knob 20 serving as a regulating member for a forcing amount is arranged on the forcing side of a switch lever 6. The gear shifting knob 20 has a rotary shaft 20a rotatably grasped by means of upper and lower covers. A discshaped operation plate 21 exposed to the outside of the upper and lower covers, a flange part 22 positioned on the back of the cover, and a half-moon-shaped plate 23 located further therebelow are integrally formed to the upper end of the rotary shaft 20a. Teeth 23a are formed in the outer periphery of the half-moon-shaped plate 23 and a position where the half-moon-shaped plate 23 is mounted on the rotary shaft 20a is caused not to coincide with the center of an arc of a circle but the half-moon-shaped rotary shaft is eccentrically mounted. Further, the flange part 22 has a side wall 22a chamfered in a polygonal shape. A rubber pin 35 adjoining to the flange part 22 is matched with the chamfered side wall 22a to form a detent, and rotation of the gear shift knob 20 is regulated in a given position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch provided in an electric power tool, and more particularly to a switch mechanism for changing a motor rotation speed according to a pulling margin of a switch lever of a handle.

[0002]

2. Description of the Related Art Among electric power tools, for example, reciprocating saws and the like which require a change in the operating speed of a blade for work, a handle is equipped with a switch mechanism for changing a motor rotation speed. For example, in JP-B-47-19838, a movable contact surface is provided on a trigger attached to a casing, and when the trigger is pushed in, the movable contact surface comes into contact with a fixed contact surface provided on the casing or the trigger. An invention has been disclosed in which the engagement amount is limited by engagement to change the rotation speed of the motor. The embodiment of the present invention also discloses a structure in which a trigger locking mechanism is provided and the trigger can be locked at the pushing position of the trigger.

[0003]

In the above switch mechanism, since the trigger is provided with the regulating member (knob, pin, arm, etc.) for changing the movable contact surface, the pulling margin adjustment may not be necessary. Even if the trigger is operated, the regulating member may be operated by mistake. Also, since the trigger itself is in a difficult-to-see place inside the handle, it is difficult to check the position and state of the regulating member, and it is difficult to operate it.
Adjustment of the pushing amount is troublesome, and it is very difficult to adjust the regulation member especially during work.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention provides a switch mechanism for an electric power tool, which facilitates the operation of the regulating member without affecting the operation of the trigger and is free from the risk of malfunction. The configuration is characterized in that a regulating member that engages with the switch lever and changes a pulling amount thereof is provided in a moving region of the switch lever so that an engaging position with the switch lever can be adjusted from outside the handle. Is.

[0005]

[Function] Since the regulating member for changing the pushing amount of the switch lever is separated from the switch lever, the pushing operation of the switch lever itself is easy, and the pushing amount can be checked because the regulating member is located on the outer surface of the handle for easy visual inspection. The tool is easy to operate, the operation is easy while the tool is in operation, and there is no risk of malfunction.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a reciprocating saw will be described below with reference to the drawings. FIG. 1 is an explanatory view showing a state in which an upper cover is removed in a handle of a reciprocating saw composed of a two-part housing. The lower cover 1 has a switch part 2 and a cord holding part 3 as mounting positions of built-in parts. The control section 4 is integrally molded. The upper and lower covers in this embodiment are commonly used for reciprocating saws and seismic drills, and the switch portion 2 accommodates a gear change switch 5 for switching the motor rotation speed together with a switch lever 6 and a lock button 7. In the case of a seismic drill or the like, the control unit 4 stores the controller and the switching knob in the storage case 10. However, in the reciprocating saw, since the speed is switched by the speed change switch 5, the storage case 10 has a heating element (not shown). The attached heat sink 8 and the plugging member 9 are housed at the switching knob position. The base end 11a of the power cord 11 is connected to the cord holder 3. Reference numeral 12 is a rubber band for preventing the cord group 13 from being dispersed. FIG. 2 is a perspective view showing the details of the switch mechanism. The switch lever 6 has a switch hole 14 formed by combining an upper cover and a lower cover, and a lower end portion 6c of the switch lever 6 is pivotally attached by a pin 15.
The convex portion 6a protruding inside contacts with the tip of the plunger type push button 5a of the speed change switch 5 held by the switch fixing tools 30 to 34 on the bottom surface of the lower cover 1, and the push button 5a is pushed as the switch lever 6 is pushed. Change the pushing amount of. Further, protrusions 6b and 6b are provided on both upper sides of the switch lever 6 so that the convex portion 6a and the push button 5a are in the abutting position when the switch lever 6 is not pushed in. The protrusions 6b and 6b are formed on the inner wall of the switch hole 14. And the lower end 14a of the switch hole 14 contacts the lower end 6c of the switch lever 6 to restrict the rotation of the switch lever 6. A lock button 7 is pivotally supported above the switch lever 6 by a pin 16, and a rear end portion 7a has a spring 18
Is urged by. An engaging recess 6d is formed on the upper surface of the switch lever 6, and when the switch lever 6 is pushed in, when the rear end 7a of the lock button 7 is pushed upward, the tip end 7b engages with the engaging recess 6d, The switch lever 6 is fixed in this position. A shift knob 20 is arranged on the pushing side of the switch lever 6 as a pushing amount regulating member. The gear shift knob 20 includes a through hole 19 formed by fitting the upper and lower covers together, and a support tool 1 projecting from the lower cover 1.
The rotating shaft 20a is rotatably held by 7a and 17b. A disc-shaped operation plate 21 exposed to the outside of the upper and lower covers is provided at the upper end of the rotary shaft 20a, and a flange portion 2 is provided at a position on the back side of the cover.
2. A meniscus 23 is formed integrally therebelow. Teeth 23a are formed on the outer periphery of the meniscus 23, and the meniscus 23 is eccentrically attached to the rotation shaft 20a not at the position where it is attached to the rotation shaft 20a. Further, the side wall 22a of the flange portion 22 is chamfered in a polygonal shape, and the rubber pin 35 adjacent to the flange portion 22 matches the chamfered side wall 22a to prevent rotation.
The rotation of the speed change knob 20 can be restricted at a predetermined position.

In the switch mechanism constructed as described above, the rotation speed of the motor changes depending on the amount of depression of the switch lever 6, but the amount of depression is determined by the position of contact with the shift knob 20. That is, as shown in FIG. 3A, when the contact point between the center of the rotating shaft 20a of the meniscus plate 23 of the speed change knob 20 and the engaging projection 6e provided at the tip of the switch lever 6 on the pressing side is farthest, the amount of pressing of the switch lever 6 is increased. Is the smallest, and when the shift knob 20 is rotated clockwise by the operation plate 21, the distance L between the contact point between the tooth 23a of the meniscus 23 and the engaging projection 6e and the center of the rotary shaft 20a is gradually reduced, and the switch lever 6 is rotated. When the shift knob 20 is further rotated, the switch lever 6 is separated from the meniscus plate 23 and can be pushed to the position closest to the rotary shaft 20a (FIG. 3b). At this time, the chamfered side wall 22a of the flange portion 22 of the speed change knob 20 contacts the rubber pin 35 on each surface, so the speed change knob 20
The rotation of can be restricted at a predetermined position. As described above, the pushing amount of the switch lever 6 can be easily adjusted by the operation plate 21 of the speed change knob 20 exposed on the upper portion of the handle, and the position thereof is also easy to confirm, so that there is no fear of erroneous operation. Further, when the rear end 7a of the lock button 7 is pushed upward, the switch lever 6 is locked so that the tip portion 7b descends with the pin 16 as a fulcrum, and the tip portion 7b is inserted into the engaging recessed portion 6d of the switch lever 6 as described above. Engage with each other to prevent the switch lever 6 from returning and enter a locked state. To release the lock, push the switch lever 6 a little further, and the spring 18 urges the rear end 7a of the lock button 7.
Returns to the lower position, the engagement with the locking recess 6d is released, and the switch lever 6 and the push button 5a also return to their original positions. Therefore, according to the lock mechanism of the present embodiment, when the switch lever 6 is pushed in, it is possible to easily operate the lock button 7 by pushing it up with, for example, the index finger, so that the switch lever 6 and the lock button 7 can be operated with one hand. Is possible.

The restricting member in the present invention is not limited to the gear shift knob of the above embodiment, and for example, a member having a step portion or an inclined surface capable of changing the contact position with the switch lever may be provided in a sliding manner. For example, the design can be arbitrarily changed without departing from the spirit of the present invention.

[0009]

As described above, according to the present invention, by separating the motor rotation speed regulating member and the switch lever, an extra member provided on the switch lever can be eliminated and the operability of the switch lever itself is improved. . Further, since the regulating member is also arranged at a position where it is easy to operate and confirm, the malfunction of the motor rotation speed switching is eliminated, and the workability of the tool itself is improved.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a handle of a reciprocating saw to which a switch mechanism in the above embodiment is applied.

FIG. 2 is a perspective view showing details of the switch mechanism of the above embodiment.

FIG. 3A is an explanatory diagram showing a pushing operation of a switch lever. (B) It is explanatory drawing which shows the pushing operation of a switch lever.

[Explanation of symbols]

1 ... Lower cover, 2 ... Switch part, 3 ... Cord holding part, 4 ... Control part, 5 ... Gear change switch, 6 ...
・ Switch lever, 7 ・ ・ Lock button, 8 ・ ・ Heat radiator plate, 9 ・ ・ Plug member, 10 ・ ・ Accommodation case, 11 ・ ・ Power cord, 12 ・ ・ Rubber band, 13 ・ ・ Cord group, 1
4 ··· Switch hole, 15, 16 · · Pin, 17 · · Supporting tool, 18 · · Spring, 19 · · Through hole, 20 · · Shift knob, 21 · · Operating plate, 22 · · Flange portion, 23 ·
・ Menrical plate, 30-34 ・ ・ Switch fixture, 35 ・ ・ Rubber pin.

Claims (1)

[Claims] 1. An electric power tool having a speed control mechanism capable of controlling a rotation speed of a motor according to a pulling margin of the switch lever, wherein the electric power tool is engaged with the switch lever within a moving area of the switch lever. A switch mechanism for an electric power tool, wherein a regulating member for changing a pulling margin is provided so that an engaging position with a switch lever can be adjusted from outside the handle.