Control switch mechanism, trigger switch, and electric tool

Provided are a control switch mechanism, a trigger switch, and an electric tool, having vibration resistance and durability and capable of preventing malfunction. The control switch mechanism (20) includes an optical sensor (21) having a light emitting element (21a) and a light receiving element (21b), and a reflector (22) that increases or decreases an amount of light received by the light receiving element (21b). An increase and a decrease in output of an operation device are controlled along with an increase and decrease in amount of light received by the light receiving element (21b) due to relative movement between the optical sensor (21) and the reflector (22).

TECHNICAL FIELD

The present invention relates to a control switch mechanism, a trigger switch, and an electric tool which control an increase and a decrease in output of an operation device.

BACKGROUND ART

A trigger switch is a switch designed for an electric tool such as an electric saw blade, and is called a trigger switch because the shape of its operation unit resembles a trigger. A speed-controllable trigger switch capable of continuously controlling a motor rotational speed has also been developed as the trigger switch. This can, for example, increase and decrease the rotational speed of the electric saw blade.

For example, as illustrated inFIG. 7, there is known a trigger switch as a speed-controllable trigger switch100as described above in which a sliding contact103is slid to a variable resistor102provided on a control circuit board101to control the motor speed by resistance change.

However, in the speed-controllable trigger switch100having adopted the sliding contact103, conduction defects due to mechanical abrasion, mechanical wear, and vibration occur in the sliding contact103and the variable resistor102, to shorten mechanical lives of the sliding contact103and the variable resistor102and make the output unstable.

In order to solve this problem, an electric tool trigger switch disclosed in Patent Document 1 has been proposed.

As illustrated inFIG. 8, an electric tool trigger switch200disclosed in Patent Document 1 includes a sliding operation unit210incorporated in a case201and moving in conjunction with the retracting operation of the trigger lever202. The sliding operation unit210includes a permanent magnet212attached to the side surface of a speed controller211and a circuit board220provided with a magnetic field sensor221at a position facing the permanent magnet212.

In the electric tool trigger switch200, the speed controller211moves in a retracting direction in conjunction with a retracting operation of a trigger lever202. At this time, a signal is generated by a change in magnetic field received by the magnetic field sensor221, and a motor speed is controlled based on the generated signal.

PRIOR ART DOCUMENT

Patent Document

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

However, the electric tool trigger switch200disclosed in conventional Patent Document 1 described above has the following problem.

In the speed-controllable trigger switch using the conventional magnet and magnetic field sensor, it is unnecessary to use the sliding contact in the motor speed controller, but is absolutely necessary to use a magnet for generating magnetic force. In the use of the magnet in an external environment such as a high temperature/high vibration region, the magnetic force or the like might deteriorate over time, resulting in malfunction.

The present invention has been made in view of the above conventional problem, and it is an object of the present invention to provide a control switch mechanism, a trigger switch, and an electric tool, having vibration resistance and durability and capable of preventing malfunction.

Means for Solving the Problem

In order to solve the above problem, a control switch mechanism according to one aspect of the present invention includes: an optical sensor that has a light emitting element and a light receiving element; and a mechanical structure that increases or decreases an amount of light received by the light receiving element. An increase and a decrease in output of an operation device are controlled along with an increase and decrease in amount of light received by the light receiving element due to relative movement between the optical sensor and the mechanical structure.

A trigger switch according to one aspect of the present invention is a trigger switch including the control switch mechanism. The trigger switch includes an output controller that increases or decreases an output of the operation device along with a change in increase or decrease of the amount of light received by the light receiving element, as well as a change in increase or decrease of the amount of light received in conjunction with a retracting operation of the trigger lever.

In order to solve the above problem, an electric tool according to one aspect of the present invention includes the trigger switch.

Effect of the Invention

According to one aspect of the present invention, it is possible to provide a control switch mechanism, a trigger switch, and an electric tool, having vibration resistance and durability and capable of preventing malfunction.

MODES FOR CARRYING OUT THE INVENTION

First Embodiment

In the first embodiment, a description will be given of a case where a control switch mechanism according to one aspect of the present invention is applied to a trigger switch of an electric tool. Note that the application is possible to an electric saw, an electric drill or the like, as the electric tool.

A configuration of a trigger switch1including the control switch mechanism in the first embodiment will be described with reference toFIG. 1toFIGS. 3(a) and 3(b).FIG. 1is a perspective view illustrating a configuration of the trigger switch1including a control switch mechanism20according to the first embodiment. InFIG. 1, in order to facilitate understanding of the internal structure, a part of the housing10is illustrated as broken.FIGS. 2(a) and 2(b)are a perspective view and a side view, respectively, illustrating one example of inclination of a reflector22in the trigger switch1.FIGS. 3(a) and 3(b)are a perspective view and a side view, respectively, illustrating another example of inclination of the reflector22in the trigger switch1.

As illustrated inFIG. 1, the trigger switch1of the first embodiment includes a printed board13, a plunger14, a return spring15, and a control switch mechanism20in a housing10formed by combining a first cover11a, a second cover11b, and a third cover11c. A trigger lever16and a bellows-like cylindrical body17are provided outside the housing10.

A circular opening10ais formed on the trigger lever16side of the first cover11aand the second cover11b, and the bellows-like cylindrical body17can be inserted into the circular opening10a.

Hook portions10b,10bare provided at the end of the first cover11a, and hook engaging portions12,12provided on the third cover11care engaged with the hook portions10b,10bof the first cover11aso that the housing10is integrally combined and fixed. Accordingly, the inside of the housing10is sealed and is in the state of not transmitting light.

Inside the housing10, the printed board13, the plunger14, the return spring15, and the control switch mechanism20are provided.

The printed board13is fixed to the third cover11cand the first cover11a, and has a function as an output controller according to one aspect of the present invention. Further, on the lower side of the printed board13, an optical sensor21made up of a light emitting element21aand a light receiving element21bis provided. With this optical sensor21built in the sealed housing10, stray light does not enter.

The plunger14is a movable body which is moved to the third cover11cside with the tip of the bellows-like cylindrical body17abutting against the plunger14via the bellows-like cylindrical body17along with a retracting operation on the trigger lever16. The return spring15made of a coil spring, for example, is provided between the plunger14and the third cover11c. When the plunger14moves to the third cover11cside, against this movement force, the return spring15urges restoration force for returning the plunger14to its original position.

As illustrated inFIGS. 2(a) and 2(b), the reflector22having an inclined surface22ais formed on the side surface of the plunger14in the moving direction, and this reflector22moves forward and backward as the plunger14moves forward and backward.

The reflector22reflects light emitted from the light emitting element21aand causes the light receiving element21bto receive the reflected light, and has a function as the mechanical structure according to one aspect of the present invention.

In the trigger switch1of the first embodiment, the control switch mechanism20is made up of the optical sensor21including the light emitting element21aand the light receiving element21b, and the reflector22. This control switch mechanism20is designed to control an increase and a decrease in output of a motor, not illustrated, being an operation device of an electric tool such as an electric saw, along with an increase and decrease in amount of light received by the light receiving element21bdue to relative movement of the optical sensor21and the reflector22.

That is, in the first embodiment, the plunger14is moved forward to the third cover11cside via the bellows-like cylindrical body17by performing the retracting operation on the trigger lever16. Hence a distance from the light emitting element21ato the inclined surface22aof the reflector22changes. This means that the amount of light received by the light receiving element21bis smaller when the distance from the light emitting element21ato the inclined surface22aof the reflector22is larger, whereas the amount of light received by the light receiving element21bis larger when the distance from the light emitting element21ato the inclined surface22aof the reflector22is smaller. In the first embodiment, for example, the inclined surface22ais inclined such that the distance from the light emitting element21ais larger on the third cover11cside and the distance from the light emitting element21ais smaller on the side opposite to the third cover11cside.

As a result, by performing the retracting operation on the trigger lever16, the plunger14is moved forward to the third cover11cside via the bellows-like cylindrical body17. Thus, the distance from the light emitting element21ato the inclined surface22abecomes small. Therefore, the more the trigger lever16is retracted, the larger amount of light received by the light receiving element21bbecomes.

Further, in the trigger switch1of the first embodiment, an output controller, not illustrated, provided on the printed board13controls an increase or decrease in output of a motor, not illustrated, being the operation device of the electric tool such as the electric saw, along with a change in increase or decrease in amount of light received by the light receiving element21b. As a result, the more the trigger lever16is retracted, the larger the output of the motor becomes and the higher the rotational speed of the electric saw blade, for example, becomes.

However, in one aspect of the present invention, this is not necessarily restrictive, and the inclination direction of the inclined surface22acan be reversed. As a result, performing the retracting operation on the trigger lever16enables reduction in amount of light received by the light receiving element21band reduction in output of the motor.

In the first embodiment, the inclination angle of the inclined surface22aof the reflector22is adjusted corresponding to the moving amount of the optical sensor21.

Specifically, as illustrated inFIGS. 3(a) and 3(b), the inclination angle of the inclined surface22aof the reflector22is made large, thereby enabling an immediate increase or decrease in output of the motor even when a relative moving amount of the optical sensor21and the reflector22is small. On the other hand, as illustrated inFIGS. 2(a) and 2(b), the inclination angle of the inclined surface22aof the reflector22is made small, thereby enabling a gentle increase or decrease in output of the motor even when a relative moving amount of the optical sensor21and the reflector22is large.

In the first embodiment, the adjustment made on the inclination angle of the inclined surface22aof the reflector22is described as illustrated inFIGS. 2(a) and 2(b)andFIGS. 3(a) and 3(b). However, not necessarily the inclination angle but also a distance in the depth direction, namely the distance from the optical sensor21to the reflector22can be adjusted. Accordingly, the amount of light received by the light receiving element21bcan greatly vary even with the short movement of the plunger14.

Further, the inclined surface22aof the reflector22is not necessarily flat, and in one aspect of the present invention, it may be curved, for example. Thus, when the sensitivity characteristic of the optical sensor21is nonlinear, it is possible to adjust, to a desired state, the output characteristic of the amount of light received by the light receiving element21bin accordance with the moving amount of the reflector22.

Meanwhile, in the trigger switch1of the first embodiment, the optical sensor21including the light emitting element21aand the light receiving element21bis fixed to the printed board13, while the reflector22is fixed to the plunger14, and the plunger14is moved forward so that the reflector22is moved forward along with the retracting operation on the trigger lever16However, in one aspect of the present invention, this is not necessarily restrictive, and it is also possible to fix the reflector22to the printed board13, fix the optical sensor21to the plunger14, and move the optical sensor21together with the plunger14. Thus, moving the optical sensor21relative to the reflector22enables control of an increase in output of the motor.

Further, in the first embodiment, the output of the motor is increased in accordance with the magnitude of the amount of light received by the light receiving element21b. However, in one aspect of the present invention, this is not necessarily restrictive, and it is also possible to reduce the output of the motor in accordance with the magnitude of the amount of light received by the light receiving element21b.

Further, in the control switch mechanism20of the first embodiment, the reflectance of the reflector22varies by changing a material, surface treatment, or a color of the reflector22. As the material for the reflector, for example, polycarbonate resin, polyprene resin, unsaturated polyester resin, polyethylene terephthalate resin, polyamide resin, or the like can be used. Further, performing the surface treatment enables adjustment of the reflectance such that the amount of light is set for the best sensitivity of the optical sensor21, namely, the range of the amount of light is set in which the amount of light is appropriately changed along with forward movement of the reflector22, and the output of the optical sensor21precisely changes. Furthermore, by using a white color as the color of the inclined surface22a, the reflectance can be improved.

It is also possible to change the surface treatment and the color in accordance with the region of the reflector22. It is thereby possible to change the amount of reflected light to a desired value by forward movement of the reflector22.

A method for operating the trigger switch1having the above configuration will be described.

First, the retracting operation is performed on the trigger lever16. Thereby, the plunger14moves forward to the third cover11cvia the bellows-like cylindrical body17. At this time, the inclined surface22aof the reflector22facing the optical sensor21fixed to the printed board13also moves forward so that the distance between the light emitting element21aand the inclined surface22agradually decreases. As a result, the amount of light received by the light receiving element21bincreases, to increase the output of the motor.

When the pushing operation on the trigger lever16is stopped in the middle and the pushing position is held, the output of the motor corresponding to the position can be obtained. In a state where the trigger lever16is fully pushed in, the motor output becomes the largest. When the pressing force of the trigger lever16is weakened, the trigger lever16returns to the original position by the return spring15.

As described above, the control switch mechanism20of the first embodiment includes the optical sensor21having the light emitting element21aand the light receiving element21b, and the mechanical structure which increase or decrease the amount of light received by the light receiving element21b. An increase and a decrease in output of the operation device are controlled along with an increase and decrease in amount of light received by the light receiving element21bdue to relative movement between the optical sensor21and the mechanical structure.

As a result, in the first embodiment, the amount of light received by the light receiving element21bis detected by the non-contact method using the optical sensor21that includes the light emitting element21aand the light receiving element21b. This is thus not a contact type switch, so that vibration resistance, durability and detection accuracy do not deteriorate due to abrasion of contacts. Therefore, in the control switch mechanism20of the first embodiment, the mechanical life of the sliding contact portion in the conventional control switch can be improved. In addition, there is no intermittent contact failure due to an influence of vibration exerted by the sliding contact portion, so that a stable output can be obtained.

Further, in the optical sensor21including the light emitting element21aand the light receiving element21b, deterioration over time does not occur in the use in an external environment such as a high temperature/high vibration region. In addition, the output voltage does not lower or fluctuate due to a decrease in magnetic force, so that malfunction, a change in characteristics, and an increase in variations can be prevented. This enables the quality of the control switch mechanism20to be maintained over a long period of time.

Therefore, it is possible to provide the control switch mechanism20having vibration resistance and durability and capable of preventing malfunction.

When a magnetic field sensor is used as the control switch mechanism, a built-in permanent magnet having a large thickness is preferable since the magnetic force is large and a change over time can be prevented. As a result, a wide space is required for detection. On the other hand, in the case of using the optical sensor21, the light emitting element21a, the light receiving element21b, and the region where light passes may only be those required, and the distances between the reflector22and the light emitting element21a/light receiving element21bmay only be required to be small. As a result, space saving can be realized as compared with the magnetic field sensor method. Considering that the distance between the magnetic field sensor and the permanent magnet is not simple, the use of the optical sensor21makes the structure simpler, the detection accuracy higher, and the handling easier.

In the control switch mechanism20according to the first embodiment, the optical sensor21and the mechanical structure move relative to each other, so that the amount of light received by the light receiving element21bmonotonically increases or decreases.

Accordingly, by relative movement between the optical sensor21and the reflector22having the inclined surface22a, the distance from the light emitting element21ato the reflector22monotonously changes, and the amount of light received by the light receiving element21bmonotonically increases or decreases.

As a result, it is possible to control the output of the operation device to increase or decrease, such as increasing or decreasing the output of the motor, based on a monotonous change in increase or decrease of the amount of light received by the light receiving element21b.

Further, in the control switch mechanism20according to the first embodiment, the optical sensor21is made of the reflection type optical sensor, and the mechanical structure is made of the reflector22provided at a position facing the light emitting element21a.

The control switch mechanism20can thereby be made up of the reflection type optical sensor21.

In the control switch mechanism20of the first embodiment, the reflector22can be inclined at a predetermined angle with respect to a plane vertical to the optical axis of the light emitted from the light emitting element21a.

With the inclination angle of the reflector22being the predetermined angle, the reflector22having a comparatively simple configuration can adjust an increase and a decrease in output of the operation device.

Further, in the control switch mechanism20of the first embodiment, the reflector22is inclined with respect to the plane vertical to the optical axis of the light emitted from the light emitting element21a, and the inclination angle of the reflector22may vary in accordance with a region of the reflector22corresponding to a relative moving amount between the optical sensor21and the reflector22. The meaning of that “the inclination angle of the reflector22varies in accordance with the region of the reflector22” includes that the inclination angle of the reflector22changes in the entire region of the relative moving amount of the reflector22, and includes that the inclination angle of the reflector22changes in a partial region of the relative moving amount of the reflector22.

Thus, by changing the inclination angle of the reflector in the entire region or in the partial region, a rate of change in distance from the light emitting element to the reflector with respect to the relative moving amount can be changed at any time, to adjust an increase and a decrease in output of the operation device. For example, increasing the inclination angle of the reflector enables an immediate increase or decrease in output of the operation device even when the relative moving amount between the optical sensor and the mechanical structure is small. On the other hand, making the inclination angle of the reflector small enables a gentle increase or decrease in output of the operation device even when the relative moving amount between the optical sensor and the mechanical structure is large.

Further, in the control switch mechanism20of the first embodiment, the reflectance of the reflector22varies by changing a material, surface treatment or a color of the reflector22. The meaning of that “the reflectance of the reflector22varies in accordance with the region of the reflector22” includes that the material, the surface treatment or the color of the reflector22changes in the entire region of the relative moving amount of the reflector22, and includes that the material, the surface treatment or the color of the reflector22changes in a partial region of the relative moving amount of the reflector22.

Thus, by changing the material, the surface treatment or the color of the reflector22, the reflectance of the reflector22can be changed, to enhance the detection capability of the optical sensor21. In addition, it is possible to make the adjustment so as to obtain an appropriate amount of reflected light in accordance with the characteristics of the optical sensor21. The material of the reflector22also includes the density and the hardness of the material.

Note that the present invention is not restricted to the above embodiment, and a variety of modifications are possible within the scope of the present invention. For example, in the control switch mechanism20of the above embodiment, the reflector22is formed of the inclined surface22a. However, in one aspect of the present invention, this is not necessarily restrictive, and for example, as illustrated inFIG. 4, it is possible to form the reflector22into a staircase shape.

Accordingly, by relative movement between the optical sensor21and the stair-like reflector22, the distance from the light emitting element21ato the reflector22changes stepwise and the amount of light received by the light receiving element21bincreases or decreases stepwise.

As a result, it is possible to control the output of the operation device to increase or decrease, such as increasing or decreasing the output of the motor stepwise based on a stepwise change in increase or decrease in amount of light received by the light receiving element21b.

Another embodiment of the present invention will be described with reference toFIGS. 5 and 6(a) and6(b). Note that configurations other than those described in the second embodiment are the same as those in the first embodiment. Further, for convenience of description, members having the same functions as the members illustrated in the drawings of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

In the trigger switch1of the first embodiment, the optical sensor21is made of a transmission type optical sensor, and the mechanical structure made of the reflector22provided at the position facing the light emitting element21ais adopted. A trigger switch2of the second embodiment is different from the above in that an optical sensor31is made of a transmission type optical sensor and that a mechanical structure made of a shielding plate provided between a light emitting element31aand a light receiving element31bis provided.

The configuration of the trigger switch2provided with a control switch mechanism30in the second embodiment will be described with reference toFIGS. 5 and 6(a) and6(b).FIG. 5is a perspective view illustrating the configuration of the trigger switch2having the control switch mechanism30in the second embodiment. InFIG. 5, in order to facilitate understanding of the internal structure, a part of the housing10is illustrated as broken.FIGS. 6(a) and 6(b)are perspective views illustrating the configuration of the trigger switch2before and after retraction of the trigger lever16, respectively.

As illustrated inFIG. 5, the trigger switch2of the second embodiment is provided with the control switch mechanism30in the housing10in a sealed state.

The control switch mechanism30of the second embodiment includes the shielding plate32as a mechanical structure having a slit33, provided on the side surface of the plunger14in the moving direction, and the optical sensor31including the light emitting element31aand the light receiving element31bprovided on both sides of the shielding plate32. Therefore, in the control switch mechanism30of the second embodiment, the optical sensor31adopts a transmission type optical sensor.

The slit33has a triangular cross section in which the trigger lever16side has a large opening area as compared with that of the third cover11cside. When the plunger14is moved forward to the third cover11cside via the bellows-like cylindrical body17by the retracting operation on the trigger lever16, the shielding plate32having the slit33also moves forward to the third cover11cside.

On the other hand, an optical sensor31including the light emitting element31aand the light receiving element31bprovided on both sides of the shielding plate32is fixed to a printed board13not illustrated.

As a result, as illustrated inFIGS. 6(a) and 6(b), the opening area of the slit33increases along with forward movement of the shielding plate32to the third cover11cside, so as to increase the amount of light transmitted from the light emitting element31ato the light receiving element31bthrough the slit33. Therefore, along with forward movement of the shielding plate32to the third cover11cside, the amount of light received by the light receiving element21bincreases. That is, the more the trigger lever16is retracted, the larger the amount of light received by the light receiving element21bbecomes.

In the trigger switch2of the embodiment, an output controller, not illustrated, provided on the printed board13, not illustrated, controls an increase or decrease in output of a motor, not illustrated, being the operation device of the electric tool such as the electric saw, along with a change in increase or decrease in amount of light received by the light receiving element21b. As a result, the more the trigger lever16is retracted, the larger the output of the motor becomes and the higher the rotational speed of the electric saw blade, for example, becomes.

However, in one aspect of the present invention, this is not necessarily restrictive, and the direction of the triangular opening of the slit33can be reversed with respect to the direction of moving forward and backward. As a result, performing the retracting operation on the trigger lever16enables reduction in amount of light received by the light receiving element21band reduction in output of the motor.

As described above, in the control switch mechanism30of the second embodiment, the slit33through which the light emitted from the light emitting element31apasses is formed in the shielding plate32and the opening area of the slit33in the shielding plate32varies in accordance with the region of the shielding plate32, corresponding to the relative moving amount between the optical sensor31and the shielding plate32. The meaning of that “the opening area of the slit33in the shielding plate32varies in accordance with the region of the shielding plate32” includes that the opening area of the slit in the shielding plate32changes in the entire region of the relative moving amount of the shielding plate32, and includes that the opening area of the slit33in the shielding plate32changes in a partial region of the relative moving amount of the shielding plate32.

As a result, the size of the opening area of the slit33in the shielding plate32changes with respect to the relative moving amount between the optical sensor31and the shielding plate32, whereby it is possible to control an increase and a decrease in amount of light received by the light receiving element21band adjust an increase and a decrease in output of the motor.

In the trigger switch2of the embodiment, the optical sensor31including the light emitting element31aand the light receiving element31bis fixed to the printed board13, while the shielding plate32is fixed to the plunger14, and the plunger14is moved forward so that the shielding plate32is moved forward along with the retracting operation on the trigger lever16. However, the present invention is not necessarily restricted thereto, and it is also possible to fix the shielding plate32to the printed board13, fix the optical sensor31to the plunger14, and move the optical sensor31forward and backward together with the plunger14. Therefore, moving the optical sensor31relative to the shielding plate32enables control of an increase in output of the motor.

Further, in the second embodiment, the output of the motor is increased in accordance with the magnitude of the amount of light received by the light receiving element31b. However, in one aspect of the present invention, this is not necessarily restrictive, and it is also possible to reduce the output of the motor in accordance with the magnitude of the amount of light received by the light receiving element31b.

In the above description, the shielding plate32has the slit33, but it does not mean that the slit33is necessarily required. For example, the shielding plate32without the slit33can also shield the space between the light emitting element31aand the light receiving element31b. This also enables control of an increase and a decrease in amount of light received by the light receiving element21b. Specifically, when there is no slit33in the shielding plate32, a transmittance of the shielding plate32is changed by changing the material, the surface treatment or the color of the shielding plate32, so that an increase and a decrease in amount of light received by the light receiving element31bcan be controlled. In this case, the meaning of that “the transmittance of the shielding plate32is changed” includes that the material, the surface treatment, or the color of the shielding plate32is changed in the entire region of the relative moving amount of the shielding plate32, and includes that the material, the surface treatment, or the color of the shielding plate32is changed in a partial region of the relative moving amount of the shielding plate32.

As described above, in the control switch mechanism30of the second embodiment, the optical sensor31is made of a transmission type optical sensor. The mechanical structure is made up of the shielding plate32which is provided between the light emitting element31aand the light receiving element31band which increases or decreases the amount of light received by the light receiving element31bby relative movement between the optical sensor31and the mechanical structure.

Accordingly, the control switch mechanism30can be made up of the transmission type optical sensor31by using the transmission type optical sensor.

As described above, the trigger switches1,2and the electric tool according to the embodiments are provided with the control switch mechanisms20,30.

It is thus possible to provide the trigger switches1,2and the electric tool provided with the control switch mechanisms20,30having vibration resistance and durability and capable of preventing malfunction.

As described above, in order to solve the above problem, a control switch mechanism according to one aspect of the present invention includes: an optical sensor that has a light emitting element and a light receiving element; and a mechanical structure that increases or decreases an amount of light received by the light receiving element. An increase and a decrease in output of an operation device are controlled along with an increase and decrease in amount of light received by the light receiving element due to relative movement between the optical sensor and the mechanical structure.

For example, a conventional control switch mechanism of a sliding contact type is present, but has a problem where the mechanical life of the sliding contact is short and the output is unstable. Further, a control switch mechanism of a magnet type is present, but has the problem of deterioration over time such as magnetic force deterioration. In any case, the durability performance is inferior.

In contrast, in one aspect of the present invention, the control switch mechanism includes an optical sensor having a light emitting element and a light receiving element, and a mechanical structure that increases or decreases the amount of light received by the light receiving element. Then, an increase and a decrease in output of the operation device is controlled along with an increase and decrease in amount of light received by the light receiving element due to relative movement between the optical sensor and the mechanical structure.

As a result, in one aspect of the present invention, the amount of light received by the light receiving element is detected by the non-contact method using an optical sensor that includes the light emitting element and the light receiving element. This is thus not a contact type switch, so that durability does not deteriorate due to abrasion of contacts.

Further, in the optical sensor including the light emitting element and the light receiving element, deterioration over time does not occur in the use in an external environment such as a high temperature/high vibration region, and malfunction does not occur.

Therefore, it is possible to provide a control switch mechanism having vibration resistance and durability and capable of preventing malfunction.

In the control switch mechanism according to one aspect of the present invention, in the control switch mechanism, the mechanical structure is formed so as to monotonically increase or decrease the amount of light received by the light receiving element by relative movement between the optical sensor and the mechanical structure.

As the mechanical structure, for example, a reflector having an inclined surface on the surface facing the light emitting element can be installed. Accordingly, by relative movement between the optical sensor and the reflector having the inclined surface, the distance from the light emitting element to the reflector monotonously changes, and the amount of light received by the light receiving element monotonically increases or decreases.

As a result, it is possible to control the output of the operation device to increase or decrease, such as increasing or decreasing the output of the motor, based on a monotonous change in increase or decrease of the amount of light received by the light receiving element.

In the control switch mechanism according to one aspect of the present invention, in the control switch mechanism, the mechanical structure is formed so as to increase or decrease stepwise the amount of light received by the light receiving element by relative movement between the optical sensor and the mechanical structure.

As the mechanical structure, for example, a reflector that changes its distance stepwise can be installed on the surface facing the light emitting element. Accordingly, by relative movement between the optical sensor and the reflector that changes its distance stepwise, the distance from the light emitting element to the reflector changes stepwise and the amount of light received by the light receiving element increases or decreases stepwise.

As a result, it is possible to control the output of the operation device to increase or decrease, such as increasing or decreasing the output of the motor stepwise, based on a stepwise change in increase or decrease of the amount of light received by the light receiving element.

In the control switch mechanism according to one aspect of the present invention, in the control switch mechanism, the optical sensor is made of a reflection type optical sensor, and the mechanical structure is made of a reflector provided at a position facing the light emitting element.

The control switch mechanism can thereby be made up of the reflection type optical sensor by using the reflection type optical sensor.

Further, in the control switch mechanism according to one aspect of the present invention, the reflector is inclined at a predetermined angle with respect to a plane vertical to an optical axis of light emitted from the light emitting element.

With the inclination angle of the reflector being the predetermined angle, the reflector having a comparatively simple configuration can adjust an increase and a decrease in output of the operation device.

In the control switch mechanism according to one aspect of the present invention, in the control switch mechanism, the reflector is inclined with respect to a plane vertical to an optical axis of light emitted from the light emitting element, and an inclination angle of the reflector varies in accordance with a region of the reflector in accordance with a relative moving amount between the optical sensor and the mechanical structure. The meaning of that “the inclination angle of the reflector varies in accordance with a region of the reflector” includes that the inclination angle of the reflector changes in the entire region of the relative moving amount of the reflector, and includes that the inclination angle of the reflector changes in a partial region of the relative moving amount of the reflector.

Thus, by changing the inclination angle of the reflector in the entire region or in the partial region, a rate of change in distance from the light emitting element to the reflector with respect to the relative moving amount can be changed at any time, to adjust an increase and a decrease in output of the operation device. For example, increasing the inclination angle of the reflector enables an immediate increase or decrease in output of the operation device even when the relative moving amount between the optical sensor and the mechanical structure is small. On the other hand, making the inclination angle of the reflector small enables a gentle increase or decrease in output of the operation device even when the relative moving amount between the optical sensor and the mechanical structure is large.

Further, in the control switch mechanism according to one aspect of the present invention, a reflectance of the reflector varies in accordance with a region of the reflector by changing a material, surface treatment, or a color of the reflector. The meaning of that “the reflectance of the reflector varies in accordance with the region of the reflector” includes that the material, the surface treatment, or the color of the reflector is changed in the entire region of the relative moving amount of the reflector, and includes that the material, the surface treatment, or the color of the reflector is changed in a partial region of the relative moving amount of the reflector.

Thus, by changing the material, the surface treatment or the color of the reflector, the reflectance of the reflector can be changed, to enhance the detection capability of the optical sensor. In addition, it is possible to make the adjustment so as to obtain an appropriate amount of reflected light in accordance with the characteristics of the optical sensor.

Further, in the control switch mechanism according to one aspect of the present invention, in the control switch mechanism, the optical sensor is a transmission type optical sensor, and the mechanical structure is made of a shielding plate which is provided between the light emitting element and the light receiving element, and increases or decreases the amount of light received by the light receiving element by relative movement between the optical sensor and the mechanical structure.

Accordingly, the control switch mechanism can be made up of the transmission type optical sensor by using the transmission type optical sensor.

There is an on/off type switch that includes a transmission type optical sensor and shields light emitted from the light emitting element with the shielding plate. However, there is no control switch mechanism for increasing or decreasing the amount of light received by the light receiving element by relative movement between the light emitting element and the shielding plate.

In the control switch mechanism according to one aspect of the present invention, in the control switch mechanism, a slit through which light emitted from the light emitting element passes is formed in the shielding plate, and an opening area of the slit in the shielding plate varies in accordance with the region of the shielding plate, corresponding to relative moving amount between the optical sensor and the mechanical structure. The meaning of that “the opening area of the slit in the shielding plate varies in accordance with the region of the shielding plate” includes that the opening area of the slit in the shielding plate changes in the entire region of the relative moving amount of the shielding plate, and includes that the opening area of the slit in the shielding plate changes in a partial region of the relative moving amount of the shielding plate.

As a result, the size of the opening area of the slit in the shielding plate changes with respect to the relative moving amount between the optical sensor and the mechanical structure, whereby it is possible to control an increase and a decrease in amount of light received by the light receiving element and adjust an increase and a decrease in output of the operation device.

In the control switch mechanism according to one aspect of the present invention, in the control switch mechanism, a transmittance of the shielding plate varies in accordance with the region of the shielding plate by changing a material, surface treatment or color of the shielding plate. The meaning of that “the transmittance of the shielding plate varies in accordance with the region of the shielding plate” includes that the material, the surface treatment, or the color of the shielding plate is changed in the entire region of the relative moving amount of the shielding plate, and includes that the material, the surface treatment, or the color of the shielding plate is changed in a partial region of the relative moving amount of the shielding plate.

Thus, when there is no opening in the shielding plate, by changing the material, surface treatment or color of the shielding plate, the transmittance of the shielding plate can be changed and the amount of light received by the light receiving element can be increased or decreased.

In order to solve the above problem, a trigger switch according to one aspect of the present invention is a trigger switch including the control switch mechanism described above, and includes an output controller that increases or decreases an output of the operation device along with a change in increase or decrease of the amount of light received by the light receiving element, as well as a change in increase or decrease of the amount of light received in conjunction with a retracting operation on the trigger lever.

According to one aspect of the invention, the trigger switch includes the control switch mechanism according to one aspect of the present invention. Therefore, when the retracting operation is performed on the trigger lever, the amount of received light increases or decreases due to the mechanical structure in conjunction with the retracting operation on the trigger lever. The output controller then increases or decreases the output of the operation device by the change in increase or decrease of the amount of light received by the light receiving element.

As a result, it is possible to provide a trigger switch that includes a control switch mechanism having vibration resistance and durability.

In order to solve the above problem, an electric tool according to one aspect of the present invention includes the trigger switch.

According to one aspect of the present invention, it is possible to provide an electric tool such as an electric saw or an electric drill provided with a trigger switch that includes a control switch mechanism having vibration resistance and durability.

The present invention is not restricted to each of the embodiments described above, but can be subjected to a variety of changes in the scope shown in the claims. An embodiment obtained by appropriately combining technical units disclosed respectively in different embodiments is also included in a technical scope of the present invention.

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