JP5536598B2 - Shift switch - Google Patents

Description

  The present invention relates to a shift switch that is attached to a power tool and that can output an electrical signal for increasing or decreasing the amount of power supplied to a motor of the power tool in accordance with the amount of displacement of a switch operation unit.

A related art speed change switch is described in Patent Document 1.
As shown in FIG. 9, a shift switch 100 of Patent Document 1 includes a trigger 102 that is pulled by a finger, a sliding variable resistor (not shown) that is linked to the pulling operation of the trigger 102, and the like. Part 105. The trigger 102 includes a support shaft 103 that protrudes rearward (rightward in the drawing), and the support shaft 103 is supported by a bearing 105j of the switch body 105 in a state in which the support shaft 103 can slide in the axial direction. Further, a spring 105b biased in a direction to return the trigger 102 to the original position (left end position) is provided in the switch body 105.
Therefore, when the trigger 102 is pulled against the force of the spring 105b, the speed change switch 100 is turned on, and the resistance value decreases as the pulling operation amount of the trigger 102 increases. Then, as the resistance value of the shift switch 100 decreases, the amount of power supplied to the motor of the electric tool increases, and the rotational speed of the motor increases. Further, when the trigger 102 is returned to the original position by the force of the spring 105b, the shift switch 100 is turned off, the power supply amount to the motor of the electric tool becomes zero, and the motor stops.

JP 2003-260675 A

  However, since the shift switch 100 described above is configured to change the resistance value of the variable resistor in accordance with the increase or decrease of the pulling operation amount of the trigger 102, the movement amount (stroke) of the trigger 102 relative to the switch body 105 is set to be relatively large. There is a need. For this reason, the speed change switch 100 is enlarged, and the degree of freedom of mounting the speed change switch 100 with respect to the electric tool is reduced. Furthermore, since the stroke of the trigger 102 with respect to the switch body 105 is relatively large, the waterproof structure of the electric tool equipped with the shift switch 100 becomes complicated.

  The present invention has been made to solve the above-described problems, and the problem to be solved by the present invention is to reduce the amount of displacement of the switch operating portion with respect to the switch body and improve the degree of freedom of mounting the shift switch. At the same time, it is to simplify the waterproof structure of the power tool.

The above-described problems are solved by the inventions of the claims.
The invention of claim 1 is a shift switch that is attached to an electric tool and that can output an electric signal for increasing or decreasing the amount of electric power supplied to the motor of the electric tool according to the amount of displacement of the switch operation unit, A switch main body that is housed in the housing of the electric tool and is mounted in a state in which the electric tool cannot be moved relative to the housing, and provided in the switch main body, when the pressing force is received by the load receiving portion and distorted. A load sensor configured to be able to output an electrical signal corresponding to the amount of strain of the switch, and the switch operation unit is attached to the surface of the housing in a state of being relatively displaceable with respect to the housing, Ri Contact includes a load transmitting portion that transmits the pressing force applied to the switch operation unit to the load receiving portion of the load sensor, wherein the load transmitting portion of the switch operating unit load cell The load receiving portion of the sub always held in abutment, the maximum displacement amount of the switch operation unit is characterized in that it is set to 5mm or less.

According to the present invention, the switch operation unit is configured to be able to transmit the pressing force applied to the switch operation unit to the load sensor, and the load sensor converts the amount of distortion when receiving the pressing force into distortion into an electric signal. It is configured to be able to. In other words, the shift switch is configured to output an electric signal corresponding to the pressing force applied to the switch operation unit, and the electric power supply amount to the motor of the electric tool can be increased or decreased by the electric signal.
For this reason, the maximum displacement amount of the switch operation unit is theoretically equal to the maximum strain amount of the load sensor, and the displacement amount (stroke) of the switch operation unit with respect to the switch body unit is greatly increased compared to the conventional variable resistance method. Can be reduced. Thereby, the speed change switch can be reduced in size, and the degree of freedom of the mounting position is improved.
In addition, since the maximum displacement (stroke) of the switch operation section is 5 mm or less, for example, the surface of the housing and the switch operation section can be covered with a film or the like, and the waterproof structure of the electric tool becomes simple. .

According to the second aspect of the present invention, the switch body portion is provided at the base end portion of the handle portion of the electric power tool, the housing including a cylindrical housing body and a handle portion protruding radially from a side surface of the housing body. Is mounted.
That is, since the trigger stroke of the shift switch can be reduced, the operability is improved.

According to the invention of claim 3, the switch main body is mounted on the rear portion of the housing main body of the electric tool, the housing including a cylindrical housing main body and a handle portion protruding radially from the side surface of the housing main body. The switch operation unit is attached to a rear end surface of the housing main body.
For this reason, the speed change operation of the electric tool can be performed by pressing the rear end surface of the housing body, and the usability of the electric tool is improved.

According to a fourth aspect of the present invention, the switch operating portion includes an operating portion main body disposed outside the housing, a shaft portion that is passed through the opening of the housing, and a pressing force applied to the load sensor inside the housing. The shaft portion is formed of an elastic material and seals the opening of the housing.
According to the invention of claim 5, the switch operating portion includes an operating portion main body arranged outside the housing, a shaft portion passed through the opening of the housing, and a pressing force inside the housing to the load sensor. A load transmitting portion for transmitting, the operation portion main body, the shaft portion, and the load transmitting portion are integrally formed of an elastic material, and the shaft portion seals an opening of the housing. To do.
As described above, the waterproof structure of the electric tool is simplified, so that the cost can be reduced.

  According to the present invention, the degree of freedom of attachment of the speed change switch to the electric tool is improved, and the waterproof structure is simplified.

It is a whole perspective view of an electric tool provided with the speed change switch concerning Embodiment 1 of the present invention. It is a whole longitudinal cross-sectional view of the said electric tool. It is a side view of the speed change switch. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3. It is a schematic circuit diagram of the load sensor used with the said shift switch. It is a graph showing the relationship between the load applied to the load sensor used in the shift switch and the output. It is a model side view of the speed change switch concerning the example of a change. It is a side view showing the example of a change of an electric tool provided with a speed change switch. It is a side view showing the conventional speed change switch.

[Embodiment 1]
Hereinafter, the shift switch 30 according to the first embodiment of the present invention will be described with reference to FIGS. The shift switch 30 according to the present embodiment is a switch used for the impact driver 10 (hereinafter referred to as the electric tool 10), and the DC motor 20 of the electric tool 10 according to the amount of displacement of the switch operation unit (trigger 31). It is configured to output an electric signal for increasing or decreasing the amount of power supplied to the.
Here, front and rear, right and left, and top and bottom in the figure correspond to front and rear, right and left and top and bottom of the power tool 10.

<About the outline of the electric tool 10>
Before describing the shift switch 30 according to the present embodiment, an outline of the electric power tool 10 will be described.
The housing 11 of the electric power tool 10 is formed in a hollow closed cross-sectional shape by fitting the left and right housing pieces formed in a halved shape at the center in the width direction. As shown in FIG. 1, the housing 11 includes a cylindrical housing main body 12 and a handle portion 15 formed so as to protrude in a radial direction (downward) from a side portion (lower portion in FIG. 1) of the housing main body 12. It consists of and.
As shown in FIG. 2, the housing body 12 accommodates a DC motor 20, a planetary gear mechanism 24, a spindle 25, a striking force generating mechanism 26, and an anvil 27 in order from the rear side. The DC motor 20 is a driving source of the electric tool 10, and the rotation of the DC motor 20 is transmitted to the spindle 25 after being decelerated by the planetary gear mechanism 24. Then, the rotational force of the spindle 25 is converted into a rotational impact force by the impact force generating mechanism 26 including a hammer 26 h and a compression spring 26 b and transmitted to the anvil 27. The anvil 27 is a portion that rotates around an axis in response to the rotational impact force, and is supported by a bearing 12j provided at the tip of the housing body 12 so as to be rotatable about the axis and not displaceable in the axial direction.
A chuck portion 27t for mounting a driver bit, a socket bit or the like (not shown) is provided at the tip of the anvil 27.

The handle portion 15 of the housing 11 is a portion that is gripped when the user uses the electric power tool 10, and includes a grip portion 15h and a battery connecting portion 15p that is located on the protruding end (lower end) side of the grip portion 15h. It is composed of The grip portion 15h is formed with a relatively small diameter so that the user can easily grip it, and the shift switch 30 according to the present embodiment is attached to the base end portion (upper end portion) of the grip portion 15h.
Further, the battery connecting portion 15p of the handle portion 15 is configured to expand mainly in the lower front direction with respect to the grip portion 15h, and the connecting portion (not shown) of the battery 19 slides from the front to the rear. It is comprised so that it may engage.

<About shift switch 30>
As shown in FIGS. 2, 3, etc., the shift switch 30 includes a trigger 31 that is pulled by a user with a fingertip, a switch main body portion 33 housed in the handle portion 15 of the housing 11, and the switch main body portion 33. And a load sensor 35 that receives a pressing force from the trigger 31.
As shown in FIG. 3, the trigger 31 includes a trigger main body 312, a shaft portion 314, a flange portion 316, and a load transmission portion 317. The trigger main body 312 is a portion on the outside of the handle portion 15 where a finger is hung, and is formed in a substantially square plate shape as shown in FIG. Then, as shown in FIG. 3, the surface 310 of the trigger body 312 is formed in a concave arc surface so that the finger can be easily applied, and is formed in a flat shape so that the back surface is in surface contact with the surface of the handle portion 15. Has been.

A shaft portion 314 is formed at the center of the back surface of the trigger main body 312 at a right angle to the back surface, and the shaft portion 314 is inserted into the opening 15w of the handle portion 15 as shown in FIG. . Here, the opening 15w of the handle portion 15 is formed at the center position of the front upper portion of the handle portion 15 at the fitting position of the left and right handle pieces 151, 152 as shown in FIGS. For this reason, when fitting the left and right handle pieces 151, 152, the shaft portion 314 of the trigger 31 can be passed through the opening 15 w of the handle portion 15. Here, the shaft portion 314 is formed of an elastic body, and is configured to be able to seal the opening 15w while being passed through the opening 15w of the handle portion 15.
A flange portion 316 that presses the periphery of the opening 15 w of the handle portion 15 from the inside of the handle portion 15 is fixed coaxially with the shaft portion 314 at the tip of the shaft portion 314. A hemispherical load transmitting portion 317 is provided coaxially with the shaft portion 314 at the center of the surface of the flange portion 316 (on the side opposite to the shaft portion 314).
Thus, since the shaft portion 314 of the trigger 31 is passed through the opening 15w formed in the center of the front surface of the handle portion 15, the trigger 31 can be relatively displaced in the axial direction (front-rear direction) of the shaft portion 314. In this state, it is attached to the front surface of the handle portion 15.

The switch body 33 is an electric circuit board provided with a load sensor 35, and is fixed to the inside of the handle portion 15 in a state of facing the back surface of the trigger 31, as shown in FIGS. That is, the left and right handle pieces 151, 152 of the handle portion 15 are formed with longitudinal grooves 151m, 152m in which the left end edge and the right end edge of the switch body portion 33 are fitted at predetermined positions. Then, the left and right edges of the switch body 33 are fitted into the longitudinal grooves 151m and 152m of the left and right handle pieces 151 and 152, so that the switch body 33 is opposed to the trigger 31 and the handle 15 It comes to be fixed inside.
On the surface of the switch body 33, the load sensor 35 is positioned at a position where the load transmitting portion 317 of the trigger 31 abuts. The load sensor 35 is provided with a load receiving portion 35r, and the load receiving portion 35r is configured to receive a pressing force from the load transmitting portion 317 of the trigger 31. The load receiving portion 35r of the load sensor 35 receives a pressing force from the load transmitting portion 317 of the trigger 31, so that the load sensor 35 is distorted, and the resistance value of the load sensor 35 is changed by the amount of the distortion. ing. That is, as shown in the schematic diagram of FIG. 5, the load sensor 35 is represented by a resistance bridge circuit, and is configured such that the resistance ratio changes in accordance with the amount of strain. Therefore, when a predetermined voltage is applied to the power supply terminal of the bridge circuit by the electric circuit of the switch body 33, a voltage signal proportional to the pressing force (distortion amount) is output from the output terminal as shown in FIG. It becomes like this.
That is, when the trigger 31 is pulled and the pressing force applied to the trigger 31 is applied from the load transmitting portion 317 of the trigger 31 to the load receiving portion 35r of the load sensor 35, the load sensor 35 (shift switch 30) is A voltage signal proportional to the pressing force can be output.
Here, the maximum displacement when the trigger 31 is pulled is set to 5 mm or less.
That is, the trigger 31 corresponds to the switch operation unit of the present invention, and the trigger main body 312 corresponds to the operation unit main body of the present invention.

The output signal of the shift switch 30 is input to a control circuit (not shown) of the electric tool 10. The control circuit is configured so that the power supplied to the DC motor 20 can be adjusted by PWM control based on the output signal (voltage signal) of the shift switch 30. That is, by pulling the trigger 31 of the speed change switch 30, when the pressing force applied to the trigger 31 increases, the output voltage of the speed change switch 30 increases and the power supplied to the DC motor 20 increases. As a result, the rotational speed of the DC motor 20 increases.
On the contrary, when the pressing force applied to the trigger 31 is loosened, the output voltage of the speed change switch 30 is lowered, the power supplied to the DC motor 20 is reduced, and the rotational speed is lowered.

<Advantages of Shift Switch 30 According to this Embodiment>
According to the speed change switch 30 according to the present embodiment, the trigger 31 is configured to be able to transmit the pressing force applied to the trigger 31 to the load sensor 35, and the load sensor 35 is distorted when receiving the pressing force and distorting. It is configured to convert the quantity into an electrical signal. That is, the shift switch 30 is configured to output an electrical signal corresponding to the pressing force applied to the trigger 31, and configured to increase or decrease the amount of power supplied to the DC motor 20 of the electric tool 10 by the electrical signal. Has been.
For this reason, the maximum displacement amount of the trigger 31 is theoretically equal to the maximum strain amount of the load sensor 35 and the like, and the displacement amount of the trigger 31 relative to the switch main body 33 compared with the conventional variable resistance type shift switch ( Stroke) can be greatly reduced. Thereby, the speed change switch 30 can be reduced in size and the freedom degree of the attachment position of the speed change switch 30 improves.
Further, since the maximum displacement (stroke) of the trigger 31 is 5 mm or less, the waterproof structure of the electric power tool 10 is simplified as shown in FIG.

<Example of change>
Here, the present invention is not limited to the above-described embodiment, and can be modified without departing from the gist of the present invention. For example, in the present embodiment, as shown in FIG. 3 and the like, the trigger 31 of the speed change switch 30 includes a trigger body 312, a shaft portion 314, a flange portion 316, and a load transmission portion 317, and the shaft portion 314 is handled as a handle. An example is shown in which the trigger 31 is attached to the surface of the handle portion 15 in a state where the trigger 31 can be relatively displaced with respect to the handle portion 15 by passing through the opening 15w of the portion 15. However, as shown in FIG. 7, an opening 15w through which the trigger 31 is passed is formed on the front surface of the handle portion 15, and the trigger 31 is placed on the back side of the rubber plate 37 in a state where the opening 15w is closed with a rubber plate 37 or the like. A fixed configuration is also possible. For this reason, the waterproof structure is further simplified.
Further, in the present embodiment, the trigger-type shift switch 30 configured to be disposed on the front upper portion of the handle portion 15 of the power tool 10 is illustrated. However, as shown in FIG. 8, a push button-like switch operation unit 38 is provided instead of the trigger 31, and the shift switch 30 is installed in the rear part of the housing body 12 so that the switch operation part 38 is provided on the rear end surface of the housing body 12. It is also possible to arrange. Thereby, the shifting operation of the electric power tool 10 can be performed by pressing the rear end surface of the housing main body 12, and the usability of the electric power tool 10 is improved.
Further, as shown in FIG. 8, the switch operation unit 38 can be disposed on the side surface of the housing body 12, or can be disposed on the side surface of the handle unit 15.

10 ... Electric tool 11 ... Housing 12 ... Housing body 15 ... Handle part 20 ... DC motor (motor)
30... Shift switch 31... Trigger (switch operation unit)
312 ... trigger body (operation unit body)
314 ... Shaft 317 ... Load transmission part 33 ... Switch body 35 ... Load sensor 35r ... Load receiving part 38 ... Switch operation part

Claims (5)

A shift switch that is attached to the power tool and can output an electrical signal for increasing or decreasing the amount of power supplied to the motor of the power tool according to the amount of displacement of the switch operation unit,
A switch main body housed in a housing of the electric tool and attached in a state in which the electric tool cannot move relative to the housing;
A load sensor that is provided in the switch body and configured to output an electrical signal corresponding to the amount of strain when the load is received by the load receiving portion and distorted;
The switch operation unit includes a load transmission unit that is attached to a surface of the housing so as to be relatively displaceable with respect to the housing and transmits a pressing force applied to the switch operation unit to a load receiving unit of the load sensor. Te it is,
The shift switch characterized in that the load transmitting portion of the switch operation portion and the load receiving portion of the load sensor are always kept in contact with each other, and the maximum displacement amount of the switch operation portion is set to 5 mm or less. . The shift switch according to claim 1,
The switch main body is mounted on a base end portion of the handle portion of the electric power tool including the housing having a cylindrical housing main body and a handle portion protruding in a radial direction from a side surface of the housing main body. Shift switch. The shift switch according to claim 1 ,
The switch body portion is mounted on the rear portion of the housing body of an electric tool, wherein the housing is composed of a cylindrical housing body and a handle portion protruding radially from a side surface of the housing body.
The switch according to claim 1, wherein the switch operating portion is attached to a rear end surface of the housing body. A shift switch according to any one of claims 1 to 3,
The switch operation unit includes an operation unit main body disposed outside the housing, a shaft portion that is passed through an opening of the housing, and a load transmission unit that transmits a pressing force to the load sensor inside the housing. Configured,
A transmission switch characterized in that the shaft portion is formed of an elastic material and seals an opening of the housing. A shift switch according to any one of claims 1 to 3,
The switch operation unit includes an operation unit main body disposed outside the housing, a shaft portion that is passed through an opening of the housing, and a load transmission unit that transmits a pressing force to the load sensor inside the housing. A speed change switch comprising: the operation portion main body, the shaft portion, and the load transmitting portion are integrally formed of an elastic material, and the shaft portion seals an opening of the housing.

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