JP3176257B2 - Dustproof structure of small switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small switch used for, for example, a portable electric drill and other electric tools, and more particularly, to a switch for switching the rotation of a motor in the electric tool or the like in forward and reverse directions. The present invention relates to a dustproof structure between a rotor and a switch body.

[0002]

2. Description of the Related Art Conventionally, a small switch such as a power tool used for business or home use has a rotor for switching between forward and reverse rotations of a motor.

That is, as shown in FIGS. 3 and 4, a conventional small switch 1 has an arc-shaped through-hole formed in a top surface of a switch body 2 formed of a synthetic resin insulator. 3 are provided.

[0004] A boss 4 of a rotor 4a for switching the rotation of the motor in the forward / reverse (clockwise and counterclockwise) directions by switching the flow of electric current is projected from the through hole 3 to the outside.

[0005] A switching lever 6 having an engaging hole 5 at the tip end for engaging with the boss 4 is rotated by a rotating shaft 7 fitted into a fitting hole 2 a provided on the upper surface of the switch body 2. The switch body 2 is freely provided.

When the switching lever 6 is rotated about the rotation shaft 7 as shown by an arrow in FIG. Rotated to both ends, the rotor 4a rotates within a predetermined angle range around the support shaft 4b as a rotation center. As a result, the connection of the terminals is switched, and the rotation direction of the motor is switched.

[0007]

However, in the small switch 1 according to the prior art, the boss through-hole 3 provided on the upper surface of the switch body 2 is a hole directly opened to the outside. In the case where a power tool is used for drilling holes in mortar or concrete, dust scattered around enters the inside of the switch body 2 through the through holes 3,
There is a problem that it may further adhere to the switch contacts and cause poor contact between the contacts.

As described above, the dustproof structure of the conventional small switch for switching has a problem to be solved in terms of dustproof measures.

[0009]

The gist of the present invention for solving the above-mentioned problems of the dustproof structure for a small switch according to the present invention is to provide a switching rotor rotatably provided inside a switch body, and a switching rotor. A boss protruding from a position away from the support shaft of which the tip projects outward from the through hole of the switch body, and engaging the tip of the boss with the boss around the support shaft of the rotor. And a switching lever that rotates on a rotation shaft fitted to the switch body so as to rotate the switch body, wherein at least a boss of the switch body penetrates between the switch body and the switching lever. A dustproof cover that covers the hole and rotates coaxially with the support shaft of the switching rotor is provided.

[0010] The dust-proof cover is formed in a disk shape, and is provided on its outer peripheral edge with a protruding peripheral wall that fits into a peripheral groove provided in the switch main body; The peripheral groove provided in the dust-proof cover has a tapered surface on one side; the dust-proof cover has a rotating shaft protruding at the center of rotation thereof, and the switch body has the dust-proof cover. Are provided in correspondence with the rotation shafts.

[0011]

According to the miniature switch according to the present invention, the through-hole for projecting the boss of the switching rotor to the outside is closed by the dustproof cover, so that the dust scattered around the switch enters the switch body. Intrusion is suppressed, and failure due to poor contact is improved.

Further, by providing the dust-proof cover with the peripheral wall, the dust intrusion path is lengthened accordingly and the intrusion prevention action is enhanced. If one side of the peripheral groove of the switch main body has a tapered surface, it is easy to remove dust accumulated therein. Further, by providing the dustproof cover with a rotating shaft for rotation, the dustproof cover can be smoothly rotated.

[0013]

Next, an embodiment according to the present invention will be described in detail with reference to the drawings. For easy understanding, portions corresponding to the conventional example will be denoted by the same reference numerals as those in the conventional example.

The first embodiment of the present invention, as shown in FIG. 1 and FIG. 2, is a small switch 8 for switching, comprising an electric connection switch for turning on / off a motor drive in an electric tool, and a rotation of the motor. And a switching means for switching between forward and reverse directions.

The switching means includes a switching rotor 4a having a contact for switching, and supporting shafts 4b, 4b are provided at a central portion of the switching rotor 4a, and are rotatable around the axis thereof. ing.

The rotor 4a is usually formed of a plastic circular flat plate, and a columnar boss 4 is integrally protruded from a peripheral portion of an upper surface thereof.

The tip of the boss 4 is inserted from below into an arc-shaped through hole 3 provided on the upper surface of the switch body 2 and further projects outside.

A fitting hole for rotatably supporting the support shafts 4b, 4b of the rotor 4a is provided on the switch body 2, and the upper fitting hole is a through hole in the upper surface of the switch body 2. 2b.

Next, a dustproof cover 9 is provided on the upper surface of the switch body 2 to cover at least the entire through hole 3 for the boss 4.

The dustproof cover 9 is a plastic disc having a rotary shaft 11 at its center, which is rotatably fitted in the through hole 2b of the switch body 2. A through hole 9a is provided so as to allow the tip of the boss 4 to pass therethrough.

When the boss 4 is inserted, the gap between the through hole 9a and the outer peripheral surface of the boss 4 is set to be as small as possible to prevent dust from entering.

Further, along the outer peripheral edge of the dustproof cover 9,
A peripheral wall 10 protruding toward the switch body 2 is provided. Correspondingly, a peripheral groove 12 is also provided on the switch body 2 side.

As shown in FIG. 2, the outer peripheral wall surface of the peripheral groove 12 is formed as a tapered surface 13.

The switching rotor 4a and the dustproof cover 9 are rotated through the boss 4 in a required range around the axis of the support shaft 4b and the rotating shaft 11 arranged coaxially therewith. Is what you do.

Next, the switching lever 6a is a slender plastic plate as a whole, and the boss 4
Is provided with an engagement hole 5 that engages with the front end of the first hole. The engagement hole 5 is formed as a through hole to reduce the plate thickness of the switching lever 6a, but may not be penetrated in some cases.

The switching lever 6a is connected to a rotary shaft 7 fitted in a fitting hole 2a provided in the switch body 2.
Thus, the rotary shaft 7 is manually rotated around the rotary shaft 7 within a required range.

When the small switch 8 formed as described above is used, the switching lever 6a is rotated about the rotation shaft 7 so that the boss 4 is formed in the engagement hole 5 at the tip end.
Is rotated about the support shafts 4b, 4b, and at the same time, the switching rotor 4a is rotated.

When the boss 4 rotates, the boss 4 comes into contact with the wall surface of the through hole 9a through which the boss 4 is inserted.
The dustproof cover 9 is rotated about the rotation shaft 11.

By rotating the switching rotor 4a, the rotation direction of a motor such as an electric tool can be arbitrarily switched.

When the concrete switch or the like is drilled by the small switch 8 according to the present invention, fine dust scattered around may enter the switch body 2 of the small switch 8. A gap between the switching lever 6a and the switch body 2 from the outside, a gap between the bottom surface of the peripheral groove 12 and the bottom surface of the peripheral wall 10, and an inner peripheral wall surface of the peripheral wall 10 and one peripheral wall forming the peripheral groove 12. Must be passed through, so that the intrusion path is lengthened and the intrusion of dust into the switch body 2 is prevented.

As a result, poor contact of the switch due to intrusion of dust or the like into the small switch 8 is prevented, thereby increasing the commercial value and reliability of the power tool and the like.

[0032]

As described above, the dustproof structure for a small switch according to the present invention comprises a switching rotor rotatably provided inside a switch body, and a position distant from the support shaft of the switching rotor. A boss, the tip of which protrudes from the through hole of the switch body to the outside, and the switch engages with the tip of the boss to rotate the boss about the support shaft of the rotor. A small switch consisting of a switching lever that rotates on a rotation shaft fitted to the main body,
A dustproof cover is provided between the switch body and the switching lever to cover at least the boss through hole of the switch body and to rotate coaxially with the support shaft of the switching rotor. As a result, the possibility of dust intrusion is eliminated, the switch contact failure is eliminated, and an excellent effect of increasing the commercial value and reliability of the power tool or the like is achieved.

The dust-proof cover is formed in a disk shape, and is provided on its outer peripheral edge with a protruding peripheral wall that fits into a peripheral groove provided in the switch body, so that dust can be prevented from entering. It has an excellent effect that it can be reliably prevented.

Since the peripheral groove provided in the switch body has a tapered surface on one peripheral wall, even if dust is stored in this portion, the dust is easily discharged to the outside because of the tapered surface. An excellent effect is achieved.

The dustproof cover has a rotating shaft protruding at the center of rotation thereof, and the switch body has a corresponding fitting hole into which the rotating shaft of the dustproof cover is fitted. When the switching lever is rotated, the dustproof cover, which is made via the boss, is smoothly rotated, thereby improving the operability.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a dustproof structure of a small switch according to the present invention.

FIG. 2 is a partial longitudinal sectional view of a dustproof structure of the small switch according to the present invention.

FIG. 3 is a perspective view of a main part of a dustproof structure of a small switch according to a conventional example.

FIG. 4 is a partial vertical sectional view of a dustproof structure of the small switch according to the conventional example.

[Explanation of symbols]

 1, 8 small switch, 2 switch body, 3 switch body through hole, 4 boss, 4a switching rotor, 4b support shaft, 5 engagement hole, 6, 6a switching lever, 7 axis, 9 dustproof cover, 10 Surrounding wall, 11 rotating shaft, 12 circumferential groove, 13 tapered surface.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Sho 63-184529 (JP, U) Japanese Utility Model Sho 63-26935 (JP, U) Japanese Utility Model Sho 55-40923 (JP, U) Japanese Utility Model Sho 60- 116096 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 21/08 H01H 19/06

Claims (4)

(57) [Claims] A switching rotor rotatably provided in a switch body; and a switching rotor protruding from a support shaft of the switching rotor, the tip of which is externally connected to a through hole of the switch body. And a switching lever that rotates on a rotating shaft fitted to the switch body to engage the tip of the boss and rotate the boss about the support shaft of the rotor. A small-sized switch, wherein a dustproof cover that covers at least a boss through hole of the switch body and that rotates coaxially with a support shaft of the switching rotor is provided between the switch body and the switching lever. Dustproof structure for small switches. 2. The dustproof cover is formed in a disk shape, and is provided on its outer peripheral edge with a protruding peripheral wall that fits into a peripheral groove provided in the switch body. The dustproof structure of the small switch according to claim 1. 3. The dustproof structure for a small switch according to claim 2, wherein the peripheral groove provided in the switch body has a tapered surface on one peripheral wall. 4. The dustproof cover has a rotation shaft protruding from the center of rotation of the dustproof cover, and the switch body has a fitting hole corresponding to the rotation shaft of the dustproof cover. The dustproof structure for a small switch according to claim 2 or 3, wherein: