JP4397677B2 - Power tool switch - Google Patents

Description

  The present invention relates to a switch for an electric tool that can easily change the rotational speed of an electric tool such as an electric drill.

Conventionally, as a power tool switch, for example, a movable contact piece supported by a support member fixed to the switch body and rotating around a central portion, and a movable contact piece disposed on an operation member and always in contact with the movable contact piece. A switch for direct current comprising a slidable pressing member that is pressed, and a fixed contact fixed to the switch body that contacts the movable contact at the end of the movable contact, the end of the movable contact being There is a switch that includes an engaging member disposed in a portion and an elastic member that is provided on the operation member and engages with the engaging member before contacting the fixed contact by pressing of the pressing member. .
JP 2001-155585 A

  In the known technique of Patent Document 1, an engagement member is disposed at the end of the movable contact piece, and the engagement member and the elastic member are elasticized before the movable contact comes into contact with the fixed contact by the pressing member. In this configuration, the movable contact piece is prevented from bouncing when the switch is switched by adopting a structure having a loose insertion mechanism.

  Also, in Patent Document 1, as a conventional technique, a seesaw-type swing switch that switches on / off of a power source by pressing a swing piece that performs a seesaw operation with a common terminal as a fulcrum with a presser disposed on a driving body. Is disclosed.

  A power tool switch provided with this type of seesaw-type swing switch will be described. As shown in FIG. 4, the housing 2 of the power tool switch 1 has a hole 3 formed therein. The operation member 4 is inserted in the part 3 in a slidable state. In the state shown in FIG. 4, the power tool switch 1 is in an off state.

  Since the housing 2 is divided into the housing upper member 2b and the housing bottom member 2c at the joint portion 2a, the operation member is formed in the hole 3 in a state where the housing upper member 2b and the housing bottom member 2c are divided. 4 is disposed, and the housing upper member 2b and the housing bottom member 2c are fitted to each other so that the operation member 4 can be easily inserted into the hole 3 formed in the housing 2. Yes.

  In the end portion 5 on the side of the operation member 4 inserted into the housing 2, an overhang portion 6 having a diameter larger than that of the hole portion 3, and in the direction of the arrow a indicating the traveling direction of the operation member 4. An extension 7 is formed by extending the end 5 of the operation member 4, and the protruding portion 6 is caught on the inner surface of the housing 2, whereby the operation member 4 is formed in the hole 3 formed in the housing 2. To prevent you from getting out of the box.

  For example, a spring or the like is disposed as an elastic body 8 between the inner surface of the housing 2 and the upper side of the extension portion 7 at the end portion 5 of the operation member 4. Therefore, when the pressing force is released after the operating member 4 is artificially pressed and slid in the direction of the arrow a, the operating member 4 is always urged by the elastic body 8. Therefore, the operation member 4 automatically returns to the original position.

  Further, a concave portion 9 is formed on the lower side of the extension portion 7 of the operation member 4, and a pressing member (oscilloscope) 11 urged by an elastic body 10 such as a spring slides in the concave portion 9. It is arranged in a movable state.

  On the other hand, a fixed terminal 12 and a support member 13 are disposed below the operation member 4 in the housing 2. The fixed terminal 12 and the support member 13 are made of a conductive material such as metal, and a part of the fixed terminal 12 and the support member 13 are connected to an electric circuit. For example, the fixed terminal 12 is connected to an electric circuit such as a power source. 13 is connected to an electric circuit such as a load.

  As shown in FIG. 5, the support members 13 are arranged in pairs, and bifurcated support portions 13 a and 13 b are formed on the upper end portion of the support member 13.

  A movable contact piece 14 formed by, for example, bending a plate-shaped metal is disposed on the upper portion of the support member 13, and overhang portions 14 a formed on both sides of the movable contact piece 14 are provided. Since the movable contact piece 14 is rotatably supported between the bifurcated support portions 13a and 13b of the support member 13 arranged in a pair on both sides of the movable contact piece 14, the movable contact piece 14 is The support member 13 does not fall off from the upper part, and can be rotated in a seesaw shape with the upper part of the support member 13 as a fulcrum.

  Since the pressing surface 15 of the pressing member 11 is in contact with the movable contact piece 14 and the pressing member 11 is biased by the elastic body 10, the pressing surface 15 of the pressing member 11 is always movable. The piece 14 is pressed.

  Therefore, when the operating member 4 is artificially pressed and slid in the direction of the arrow a, the pressing member 11 disposed in the concave portion 9 of the operating member 4 also moves together with the operating member 4, so that FIG. As shown in FIG. 2, the movable contact piece 14 pressed against the pressing surface 15 of the pressing member 11 rotates in the direction of the arrow b, and the end of the movable contact piece 14 comes into contact with the fixed terminal 12. .

  As described above, when the fixed terminal 12 and the end of the movable contact piece 14 come into contact with each other, the fixed terminal 12 and the support member 13 are electrically connected via the movable contact piece 14. The switch 1 is turned on.

  At this time, a contact 16 or the like may be provided at the end of the movable contact piece 14 to facilitate contact with the fixed terminal 12.

  When the pressing force of the operating member 4 is released, the operating member 4 is automatically returned to the original position by the elastic body 8, and the pressing member 11 moves along with the operating member 4. Is rotated in the direction opposite to the arrow b, the contact between the end of the movable contact piece 14 and the fixed terminal 12 is released, and the power tool switch 1 returns to the OFF state.

  Since this electric tool switch 1 is generally used for a so-called single speed switch that does not adjust the rotational speed, as shown in FIG. 7, the sliding distance (stroke) of the operation member 4 and the switch The distance between ON / OFF of the power tool switch 1 is improved, and the stroke in which the operation member 4 can slide is short when the power tool switch 1 is ON.

  As a modification of the prior art, for example, in order to change the rotational speed of the electric tool motor, the position of the fulcrum is moved horizontally toward the hole 3, that is, the position of the support member 13 is changed to the hole 3. FIG. 8 shows a case where the stroke in which the operating member 4 is slidable is extended over a wide range while the power tool switch 1 is kept in the ON state.

  Thus, by making the position of the fulcrum closer to the hole 3, the slidable length between the operation member 4 and the pressing member 11 is lengthened, that is, the stroke when the power is turned on is long and wide. Will be able to.

  However, in the modification of the prior art, as shown in FIG. 9, the movable contact piece is moved by the pressing member 11 as the operating member 4 slides and is pressed against the pressing surface 15 of the pressing member 11. When the end of the movable contact piece 14 comes into contact with the fixed terminal 12 and further makes a full stroke, the distance between the fixed terminal 12 and the support member 13 serving as a fulcrum is separated. The pressure with respect to the contact between the contact piece 14 and the support member 13 is reduced.

  Therefore, if the modified example of the prior art is used for a switch that requires a large current, such as a power tool, the movable contact piece 14 bounces due to vibrations generated from the power tool. For example, it is necessary to add parts such as an auxiliary brush to prevent the bounce.

  Further, when it is attempted to improve the operability by shortening the distance at which the power tool switch 1 is switched from OFF to ON by operating the operation member 4, it is necessary to dispose the pressing member 11 near the fixed terminal 12 in advance. Therefore, there arises a problem that the stroke in which the operation member 4 can slide is shortened.

  That is, the distance by which the power tool switch 1 is switched from OFF to ON by operating the operation member 4 is shortened, and the stroke in which the operation member 4 can slide while the power tool switch 1 is maintained ON. Since there is a contradictory relationship with making the power tool long and wide, it is difficult to shorten the distance at which the power tool switch 1 is switched from OFF to ON and to make the stroke over which the operation member 4 can slide long and wide. It is.

  Therefore, in the conventional power tool switch, the contact state between the end of the movable contact piece and the fixed terminal is improved without increasing the number of components, and the power switch is switched from OFF to ON by operating the operation member. Therefore, there is a problem to be solved by shortening the sliding distance of the operating member for the purpose and making the slidable stroke of the operating member long and wide while maintaining the ON state of the switch.

As a specific means for solving the problems of the conventional example described above, the switch for an electric tool according to the present invention includes an operation member that is slidably inserted into a hole formed in the housing, and is formed on the operation member. A pressing member disposed in the recessed portion, a projecting portion, a movable contact piece that rotates in a seesaw shape with the position of the projecting portion serving as a fulcrum, and that the pressing surface of the pressing member contacts and presses, and the movable contact A switch for an electric tool comprising a support member that engages with an overhanging portion of the piece and supports the movable contact piece in a rotatable state, and a fixed terminal that comes into contact with an end of the movable contact piece. In the pressing member, the pressing surface is formed by a flat low level pressing portion having the same width or substantially the same width and a high level pressing portion formed in a convex shape, and the high level pressing portion is engaged with the support member. Abut the projecting part near the fulcrum As the operation member slides, the high-level pressing portion passes through a fulcrum and rotates the movable contact piece, so that the end of the movable contact piece contacts the fixed terminal, and then the low-level pressing portion. Is to maintain the contact state between the end of the movable contact piece and the fixed terminal by maintaining the state in contact with the movable contact piece.

As described above, the power tool switch according to the present invention is disposed in the operating member inserted in a slidable manner in the hole formed in the housing, and the recess formed in the operating member. A pressing member and an overhanging portion are provided. The movable contact piece rotates in a seesaw shape with the position of the overhanging portion serving as a fulcrum, and the pressing surface of the pressing member contacts and presses, and the overhanging portion of the movable contact piece is engaged and a support member for supporting at rotatable state the movable contact piece, a switch for a fixed terminal, the electric power tool consisting in contact with an end portion of the movable contact piece, wherein the pressing member is pressed The surface is formed by a flat low-level pressing portion having the same width or substantially the same width and a high-level pressing portion formed in a convex shape, and the vicinity of the overhanging portion serving as a fulcrum where the high-level pressing portion is engaged with the support member As the operating member slides. The high-level pressing part passes through the fulcrum, the movable contact piece is rotated, the end of the movable contact piece comes into contact with the fixed terminal, and then the low-level pressing part comes into contact with the movable contact piece. Maintaining the contact state between the end of the movable contact piece and the fixed terminal by maintaining the state improves the contact state between the end of the movable contact piece and the fixed terminal without increasing the number of parts. In addition, the sliding distance of the operating member for switching the power switch from OFF to ON by operating the operating member is shortened, and the slidable stroke of the operating member is extended over a wide range while maintaining the ON state of the switch. It has an excellent effect that it can be made.

Next, the present invention will be described in detail based on specific embodiments.
The switch for electric tools which concerns on embodiment of this invention is demonstrated using FIGS. 1-3. In the embodiment of the present invention, the shape of the pressing member 11 of the prior art is changed, and the other configuration is the same as the prior art, and therefore the same configuration as the prior art. Since the description of these portions is duplicated, the same reference numerals are given to facilitate understanding of the drawings, and detailed description thereof will be omitted.

  FIG. 1 is a cross-sectional view schematically showing a power tool switch. The operating member 4 is slidably inserted through the hole 3 formed in the housing 2 of the power tool switch 21 and urged in a direction protruding from the housing 2 by the elastic body 8. Has been.

  On the inner peripheral surface of the hole 3, for example, a lubricating material 22 such as a synthetic resin material is disposed to reduce resistance due to friction between the hole 3 and the operation member 4. You may make it the structure which is easy to slide and into which dust does not penetrate | invade easily.

  A recess 9 is formed on the lower side of the extension 7 formed on the side of the operation member 4 inserted in the housing 2. The recess 9 is formed by an elastic body 10 such as a spring, for example. The urging pressing member 23 is arranged in a state where it can appear and disappear. As the pressing member 23, for example, an oscilloscope or the like can be used.

  A pressing surface 24 is formed at the end of the pressing member 23, and the pressing surface 24 is always in contact with the movable contact piece 25. Since the pressing member 23 is always urged by the elastic body 10, the pressing surface 24 of the pressing member 23 always abuts against the movable contact piece 25 and presses the movable contact piece 25. .

On the pressing surface 24 of the pressing member 23, a high-level pressing portion 24 a is formed at the front end side in the direction of the operation member 4 having the same width or substantially the same width , that is, in the direction of the arrow a. A lower pressing portion 24b is formed on the rear end side.

  The high pressure portion 24a is higher than the low pressure portion 24b (located below the low pressure portion 24b in FIG. 1). For example, the high pressure portion 24a may be formed in a convex shape or the like. It is preferable to form, and the low level pressing portion 24b may be formed lower than the high level pressing portion 24a (in FIG. 1, located above the high level pressing portion 24a). Is preferred.

  When the operating member 4 is artificially pressed and slid in the moving direction of the operating member 4, that is, in the direction of the arrow a, the pressing member 23 disposed in the concave portion 9 of the operating member 4 is also operated. As the member 4 slides, it moves in the direction of the arrow a. At that time, the movable contact piece 25 is formed on the distal end side of the pressing surface 24 of the pressing member 23 in the traveling direction of the operation member 4. The high-order pressing portion 24a contacts and presses the movable contact piece 25.

  When the pressing member 23 moves closer to the fixed terminal 12, the movable contact piece 25 pressed by the high-order pressing portion 24 a of the pressing surface 24 of the pressing member 23 rotates in the direction of the arrow b, and the movable contact piece 25. The contact 16 disposed at the end of the contact is in contact with the fixed terminal 12.

In other words, the higher the pressing portion 24a of the pressing surface 24 of the pressing member 23 that is formed in the advance direction of the distal end side of the operating member 4, i.e., because it is in contact with the projecting portion 25c vicinity, the operating member 4 Even when the operation, that is, the sliding distance is short, the power tool switch 21 can be easily switched from OFF to ON, so that the time for switching the power tool switch 21 from OFF to ON can be shortened.

  For this reason, it is preferable that the high-level pressing portion 24a of the pressing surface 24 of the pressing member 23 is disposed in advance in the vicinity of the position where the movable contact piece 25 starts to rotate in the direction of the arrow b. Even when the high pressure portion 24a of the pressure surface 24 of the pressure member 23 is not disposed in the vicinity of the position where the rotation starts, the high pressure portion 24a is located on the distal end side of the operation member 4 in the traveling direction. Therefore, the time for switching the power tool switch 21 from OFF to ON can be shortened.

  Subsequently, when the operating member 4 is pressed and slid in the traveling direction, that is, in the direction of the arrow a to move the pressing member 23, the high-order pressing portion 24 a of the pressing member 23 is contacted with the contact end portion 25 a of the movable contact piece 25. However, since the higher pressing portion 24a moves beyond the contact end portion 25a of the movable contact piece 25, the movable contact piece 25 cannot be pressed. As shown in FIG. 2, instead of the high-order pressing portion 24 a, the low-order pressing portion 24 b of the pressing member 23 keeps pressing against the contact end portion 25 a of the movable contact piece 25.

  As described above, when the fixed terminal 12 comes into contact with the end portion (contact 16) of the movable contact piece 25, the fixed terminal 12 and the support member 13 are electrically connected via the movable contact piece 25. The power tool switch 21 is turned on.

  In short, when the power tool switch 21 is in an off state, that is, when the fixed terminal 12 and the end portion (contact 16) of the movable contact piece 25 are not in contact, the high-order pressing portion 24a of the pressing member 23 is moved to the movable contact piece. When the operation member 4 is operated and pressed in the advancing direction, the power tool switch 21 is turned on from OFF even if the sliding distance of the operation member 4 is short, as shown in FIG. Therefore, when the operation member 4 is operated and pressed in the advancing direction, the lower position pressing portion 24b of the pressing member 23 is applied. Since the pressure can be kept in contact, the stroke when the power is turned on is longer and wider than the contact end portion 25a of the movable contact piece 25 by the distance that the higher pressing portion 24a has moved closer to the fixed terminal 12. It is possible to be.

  Thus, by maintaining the power-on state and making the sliding movement stroke of the operation member 4 long and wide, a contact piece for speed switching (not shown) attached to the operation member 4 and the contact piece Since the number of contact portions can be increased between a substrate (not shown) having a plurality of contact portions that slide and come into contact with each other, it is possible to set the switching of the rotational speed in a further multistage manner. It is useful for improving the function of the power tool.

  Further, even when the stroke when the power is turned on is long and wide, the end of the movable contact piece 25 and the fixed terminal 12 are reliably brought into contact with each other and the end of the movable contact piece 25 is fixed. Since the contact state with the terminal 12 can be improved, the bounce of the movable contact piece can also be prevented. At this time, the number of parts is not increased, and the cost can be reduced.

  And when the high level press part 24a of the press member 23 is formed in the mountain-shaped convex shape, the movement of the low level press part 24b from the high level press part 24a of the press member 23 which contacts the movable contact piece 25 is performed smoothly. Therefore, it is possible to prevent bounce and the like from occurring.

  Further, when the fixed terminal 12 and the end portion (contact point 16) of the movable contact piece 25 are welded, when the operation member 4 is released and the operation member 4 attempts to return to the original position, the operation is performed. Since the lower end portion 26 of the member 4 presses the protruding piece 25b of the movable contact piece 25, a strong force can be applied to the movable contact piece 25, and the fixed terminal 12 and the end portion of the movable contact piece 25 are separated from each other. Even when a strong force is applied to the movable contact piece 25, the projecting portion 25c of the movable contact piece 25 is supported by the bifurcated support portions 13a and 13b of the support member 13, so that the movable contact piece 25 falls off. There is no.

It is sectional drawing which showed schematically the state in which the switch for electric tools which concerns on this invention is OFF. It is sectional drawing which showed the state in which the switch for the electric tools was turned on schematically. It is the graph which showed the relationship between the sliding distance (stroke) of the operation member of the switch for electric tools, and ON / OFF of the switch for electric tools. It is sectional drawing which showed schematically the state in which the switch for electric tools of a prior art example was OFF. It is the perspective view which showed schematically the periphery in which the movable contact piece of the switch for electric tools was arrange | positioned. It is sectional drawing which showed the state in which the switch for the electric tools was turned on schematically. It is the graph which showed the relationship between the sliding distance (stroke) of the operation member of the switch for electric tools, and ON / OFF of the switch for electric tools. It is sectional drawing which showed schematically the state in which the switch for electric tools which is a modification of a prior art example is OFF. It is sectional drawing which showed the state in which the switch for the electric tools was turned on schematically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 21 Switch 2 for electric tools Housing 2a Joint part 2b Housing upper member 2c Housing bottom member 3 Hole part 4 Operation member 5 End part 6 of operation member 7 Extension part 8 Elastic body 9 Recess 10 Elastic body 11, 23 Press member 12 Fixed terminal 13 Support members 13a and 13b Fork support portions 14 and 25 Movable contact pieces 14a and 25c Overhang portions 15 and 24 Press surface 16 Contact 22 Lubricant 24a High press portion 24b Low press portion 25a Contact end portion 25b Projection piece 26 Lower end

Claims (1)

An operation member inserted in a slidable state in a hole formed in the housing;
A pressing member disposed in a recess formed in the operating member;
A movable contact piece provided with an overhanging portion, rotating in a seesaw shape with the position of the overhanging portion serving as a fulcrum, and contacting and pressing the pressing surface of the pressing member;
A support member that engages with the projecting portion of the movable contact piece and supports the movable contact piece in a rotatable state;
A fixed terminal that contacts an end of the movable contact piece;
A switch for an electric tool comprising:
In the pressing member, a pressing surface is formed by a flat low-level pressing portion having the same width or substantially the same width and a high-level pressing portion formed in a convex shape, and the high-level pressing portion is engaged with the support member. As the operating member slides, the high-order pressing part passes through the fulcrum and rotates the movable contact piece, so that the end of the movable contact piece Electric contact characterized by maintaining the contact state between the end of the movable contact piece and the fixed terminal by contacting the fixed terminal and then maintaining the state in which the lower pressing portion is in contact with the movable contact piece. Tool switch.

Images