Work tool

Abstract

This work tool (10) comprises a body (11), a grip (12), an electrode (12a), wires (16, 17), a detection circuit (15), and a touch control board (14). Wire (16) is connected to the electrode (12a) of the grip (12). The detection circuit (15) is connected to the electrode (12a) via wire (16) and detects touching of the grip (12). Wire (17) is disposed in line with wire (16) at a prescribed location on the body (11), and has an open end (17a) that is not connected to the electrode (12a). The detection circuit (15) is connected to wire (17) and detects touching of a prescribed location on the body (11). On the basis of the detection results of the detection circuit (15), the touch control board (14) determines that the grip (12) has been touched and / or determines that a prescribed location on the body (11) has been touched.

Description

Working tool

[0001] The present invention relates to a working tool that drives a tip tool by power or air, such as a grinder, a jigsaw, a chainsaw, an electric driver, etc., to perform various operations.

[0002] At work sites and factories, working tools that rotationally drive tip tools such as drills and drivers by a motor to perform desired operations are widely used. Among such working tools, there is a working tool in which an auxiliary handle is attached to the main body so that the user can use the working tool in a stable state. For example, in Patent Document 1, there are steps of determining the charges of the first and second sensor elements, comparing the determined first charge with a defined first threshold value, and comparing the determined second charge with a defined second threshold value, and when a predetermined condition exists between the determined first charge of the first sensor element and the detected second charge of the second sensor element, enabling the operation of the drive device and / or the defined activation of the drive device via a control device. A driving method of a gripping tool including the steps is disclosed.

[0003] US Patent Application Publication No. 2023 / 0170902

[0004] However, the above conventional working tool has the following problems. That is, in the working tool disclosed in the above publication, a touch sensor is provided only on the main body. For this reason, for example, in terms of design, a control board for detecting that the touch sensor has been touched is arranged at a position away from the gripping part, and in a configuration where the touch sensor and the control board are connected using an electric wire or the like, touching the part where the electric wire is arranged results in the same detection result as when touching the touch sensor. Therefore, with the conventional configuration, it has been difficult to determine which part the user is touching.

[0005] An object of the present invention is to provide a working tool capable of discriminating that it has been touched at the gripping part and / or at a location other than the gripping part in a configuration where a control part for detecting that the user has touched the gripping part is arranged at a position separated from the gripping part.

[0006] (Means for solving the problem) The work tool according to the first invention comprises a main body, a gripping part, an electrode, a first electrical component, a first detection circuit, a second electrical component, a second detection circuit, and a control unit. The gripping part is attached to the main body and is gripped by the user when in use. The electrode is provided on the gripping part. The first electrical component is connected to the electrode provided on the gripping part. The first detection circuit is provided on the main body and is connected to the electrode via the first electrical component to detect whether the gripping part has been touched by the user. The second electrical component has at least a portion of it positioned along the first wire at a predetermined location on the main body and has an open end that is not connected to the electrode. The second detection circuit is provided on the main body and is connected to the second electrical component to detect whether the predetermined location on the main body has been touched by the user. Based on the respective detection results of the first detection circuit and the second detection circuit, the control unit makes at least one of the following determinations: whether the user is touching the gripping part and whether the user is touching the predetermined location on the main body.

[0007] Here, for example, in a work tool in which it is recommended to grip both the gripping portion and a predetermined position on the main body during use, a first electrical member connected to an electrode provided on the gripping portion and a second electrical member having an open end that is not connected to the electrode and is positioned at a predetermined position on the main body, in order to determine whether the user is touching one or both of the gripping portion and the predetermined position on the main body.

[0008] Here, the work tools are, for example, grinders, jigsaws, chainsaws, electric screwdrivers, etc., and are driven by electricity or pneumatics. The first detection circuit and the second detection circuit detect when a user is touching the tool, for example, by detecting a change in capacitance. The first electrical component and the second electrical component are, for example, electric wires, elongated electrodes, etc., which electrically connect the electrodes provided on the gripping part to the control unit.

[0009] The predetermined position on the main body where at least a portion of the second electrical component is arranged along the first electrical component is, for example, a position where it is gripped by the user when using a work tool. The gripping portion is an auxiliary handle or the like attached to the main body, and may be detachable from the main body or fixed to the main body.

[0010] As a result, for example, if only the gripping portion is touched, the second electrical component is not affected, and the detection result in the first detection circuit can be used to detect that the gripping portion has been touched. Also, if only a predetermined position on the main body is touched, both the first and second electrical components are affected, and the detection result in the second detection circuit can be used to detect that the predetermined position has been touched. Furthermore, if both the gripping portion and the predetermined position on the main body are touched, the detection result in the second detection circuit can be used to detect that the predetermined position has been touched, and the first detection circuit can detect a larger change than when only the gripping portion is touched because both the first and second electrical components are affected, making it easy to determine that both have been touched. As a result, with a simple configuration combining a first electrical component connected to an electrode provided on the gripping portion and a second electrical component positioned along the first electrical component at a predetermined position and having an open end, it is possible to determine that the user has touched the electrode and / or a location other than the electrode.

[0011] The working tool according to the second invention is the same as the working tool according to the first invention, and the control unit determines that the gripping part is being touched if the first condition that the detection result in the first detection circuit has changed by a first threshold or more and the second condition that the difference between the detection result in the first detection circuit and the detection result in the second detection circuit is equal to or greater than the second threshold are met. Thus, if the first detection circuit connected to the electrode has changed by a first threshold or more and the condition that the difference between the detection result in the first detection circuit and the detection result in the second detection circuit is equal to or greater than the second threshold are met, it can be determined that the gripping part (electrode) is being touched.

[0012] In other words, if only the gripping part (electrode) is touching, the detection result will change only in the first detection circuit. On the other hand, if only a predetermined position on the main body is touching, the detection result in the first detection circuit will change because the first electrical component located at that predetermined position is connected to the electrode. Therefore, in this work tool, in addition to the first condition that the change in the detection result in the first detection circuit is greater than or equal to the first threshold, a second condition is added to the determination that the difference between the detection result in the first detection circuit and the detection result in the second detection circuit is greater than or equal to the second threshold. By doing so, if the first condition is met but the second condition is not met, it can be inferred that the user is touching the predetermined positions where the first and second electrical components are located, and thus it can be determined that only the main body is being touched. Thus, it is possible to accurately detect that the gripping part (electrode) is being touched while avoiding the erroneous determination that the gripping part (electrode) is being touched when only a predetermined position on the main body is being touched.

[0013] The working tool according to the third invention is the working tool according to the second invention, and the control unit determines that both the gripping portion and the main body portion are in contact if, in addition to the first and second conditions, the third condition is met in which the detection result in the second detection circuit has changed by a third threshold or more. Thus, in addition to the first and second conditions described above, if it is detected that the detection result in the second detection circuit has changed by a third threshold or more, it can be determined that both the gripping portion and the main body portion are in contact.

[0014] The work tool according to the fourth invention is a work tool according to the first or second invention, further comprising a drive unit provided on the main body for driving the tip tool, and a trigger switch provided on the main body for operation by the user to drive the drive unit. The first electrical component and the second electrical component are arranged near the trigger switch provided on the main body. By arranging the first electrical component and the second electrical component near the trigger switch on the main body, it is possible to detect, for example, whether the user is gripping the gripping part with their left hand and gripping the area near the trigger switch on the main body with their right hand. Therefore, the work tool can be used safely by controlling it so that the drive unit is not permitted to operate until this state is detected.

[0015] The work tool according to the fifth invention is the work tool according to the second invention, and the sensitivity for detecting contact with the gripping part, the first electrical component, and the second electrical component is switched by changing at least one of the first threshold and the second threshold. This allows the detection sensitivity and detection distance when the user is touching the components to be adjusted by changing the threshold values, taking into account work efficiency, the form of the work tool, individual differences among users, etc.

[0016] The working tool according to the sixth invention is a working tool according to the first or second invention, wherein the first electrical component and the second electrical component are made of electric wire. This makes it possible to construct a first electrical component that connects the electrode and the first detection circuit, and a second electrical component that connects the open end and the second detection circuit, using inexpensive and simple electric wire.

[0017] The working tool according to the seventh invention is the working tool according to the sixth invention, wherein the first electrical component and the second electrical component are arranged to be twisted together in a spiral manner. This minimizes the directional difference when touching the part in which the first electrical component and the second electrical component are arranged, while enabling high-precision detection of whether or not a user has touched it.

[0018] The eighth working tool according to the eighth invention is a working tool according to the first or second invention, wherein the first detection circuit is positioned at a location spaced apart from the gripping portion in the main body. This allows for detection of the user touching the gripping portion while ensuring flexibility in the layout of the first detection circuit in the main body, by electrically connecting the first detection circuit and the gripping portion via the first electrical component.

[0019] The ninth invention is a work tool according to the eighth invention, wherein the first detection circuit and the second detection circuit are located near a power supply unit that is attached to the main body in a replaceable manner. This makes it possible to shorten the power wiring that supplies power from the power supply unit to the first detection circuit and the second detection circuit.

[0020] The work tool according to the tenth invention is a work tool according to the first or second invention, wherein the first detection circuit and the second detection circuit detect whether the user has touched the tool by a change in capacitance. By detecting the change in capacitance in the first detection circuit and the second detection circuit, it is possible to easily determine whether the user has touched the tool and where they have touched it.

[0021] The eleventh invention relates to a work tool according to the first or second invention, wherein the gripping portion can be attached to the main body in a position that can be changed according to the user's dominant hand. This makes it possible to determine whether the user touched the gripping portion or a predetermined position on the main body, even when the position of the detachable gripping portion is changed according to the user's dominant hand.

[0022] The twelfth invention relates to a work tool that is a work tool according to the first or second invention, and is a grinder that polishes, grinds, and cuts an object by rotating a grinding wheel attached to the main body. This makes it possible to control the operation of the drive unit so that when a grinder with a relatively large reaction force during use is used as a work tool, for example, the drive unit is permitted to operate when the gripping part and a predetermined position on the main body are gripped.

[0023] (Effects of the Invention) In the working tool according to the present invention, in a configuration in which a control unit that detects when a user touches the gripping part is positioned at a location separated from the gripping part, it is possible to determine whether the user has touched the gripping part and / or a location other than the gripping part.

[0024] A schematic diagram showing the configuration of a work tool according to one embodiment of the present invention. A schematic diagram showing the configuration of electrodes, detection circuit, touch control board, and wires extracted from the work tool in Figure 1. (a) is a graph showing a comparative example of the detection results in the detection circuit when the gripping part and the main body are gripped, respectively. (b) is a graph showing the detection results in the detection circuit when the gripping part and the main body are gripped, respectively in the work tool of Figure 1. (a) is a schematic diagram showing the state in which the gripping part of the work tool of Figure 1 is gripped. (b) is a schematic diagram showing the state in which the vicinity of the trigger switch of the main body of the work tool of Figure 1 is gripped. (c) is a schematic diagram showing the state in which the gripping part and the vicinity of the trigger switch of the main body of the work tool of Figure 1 are gripped. Graphs showing the change in capacitance corresponding to the touch state shown in Figures 4(a), 4(b), and 4(c). Figures 4(a), 4(b), and 4(c) show the results of determining whether touch detection of the gripping part and / or the main body is met in the touch state shown.

[0025] A working tool according to one embodiment of the present invention will be described below with reference to Figures 1 to 6. In this embodiment, unnecessary detailed explanations may be omitted. For example, detailed explanations of already well-known matters and redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding by those skilled in the art. Furthermore, the applicant provides the accompanying drawings and the following explanation so that those skilled in the art can fully understand the present invention, and does not intend to limit the subject matter described in the claims by means of these.

[0026] (1) Configuration of the work tool 10 The work tool 10 according to this embodiment is, for example, a grinder that polishes, grinds, and cuts an object by rotating a grinding wheel (tip tool) 13 attached to the main body 11. As shown in Figure 1, the work tool 10 comprises a main body 11, a gripping part 12, a grinding wheel 13, a touch control board (control unit) 14, a detection circuit (first detection circuit, second detection circuit) 15, an electric wire (first electrical component) 16, an electric wire (second electrical component) 17, a drive unit 18, and a power supply unit 19.

[0027] As shown in Figure 1, the main body 11 is a housing portion equipped with a drive unit 18 for driving the work tool 10, and a gripping part 12 is detachably attached to its side. A power supply unit 19 is detachably attached to the lower end of the main body 11. The main body 11 is also provided with a trigger switch 18a that is operated when driving the drive unit 18. The gripping part 12 is an auxiliary handle that is attached to either the left or right side of the main body 11 according to the user's dominant hand, and is gripped by the user when in use. As shown in Figure 1, the gripping part 12 is provided with an electrode 12a for detecting when the user grips the gripping part 12.

[0028] As shown in Figure 1, the electrode 12a is provided on the surface of the gripping part 12 that is gripped by the user. The electrode 12a is provided to detect touch to the gripping part 12 by detecting the change in capacitance caused, for example, by the user's fingers touching it. That is, when the user grips the electrode 12a or the wires 16 and 17, their respective capacitances change, and touch to the gripping part 12 and the main body 11 is detected.

[0029] The grinding wheel (tip tool) 13 is a type of tool attached to the tip of the work tool 10 and is rotationally driven by the drive unit 18. The touch control board (control unit) 14 is located at the bottom of the main body 11, as shown in Figure 1. Based on the detection result in the detection circuit 15, the touch control board 14 determines whether the user is touching at least one of the gripping part 12 and the area near the trigger switch 18a on the main body 11.

[0030] The details of the touch detection process on the touch control board 14 will be described in detail later. As shown in Figure 1, the detection circuit (first detection circuit, second detection circuit) 15 is located on the touch control board 14 which is positioned at the lower end of the main body 11, and is electrically connected to the electrode 12a via the wire 16. The detection circuit 15 detects when the gripping part 12 is touched by the user by detecting a change in capacitance. The detection circuit 15 is also connected to the wire 17 and detects when the area near the trigger switch 18a (a predetermined position) on the main body 11 is touched by the user.

[0031] Furthermore, the detection circuit 15 is located in the main body 11 at a position spaced apart from the gripping portion 12, and is positioned near the power supply unit 19, which is attached to the main body 11 in a replaceable manner. Therefore, as shown in Figure 2, the electrode 12a provided on the gripping portion 12 and the detection circuit 15 are electrically connected via the electric wire 16. Although the detection circuit 15 is shown as a single circuit connected to the electric wires 16 and 17 respectively, it may also be configured in which a detection circuit connected to the electric wire 16 and a detection circuit connected to the electric wire 17 are provided separately.

[0032] As shown in Figure 1, the first end of the electric wire (first electrical component) 16 is connected to an electrode 12a provided on the gripping portion 12, and the second end opposite to the first end is connected to the detection circuit 15. As shown in Figure 1, at least a portion of the electric wire (second electrical component) 17 is arranged along the electric wire 16 near the trigger switch 18a on the main body portion 11. As shown in Figure 2, the first end of the electric wire 17 is not connected to the electrode 12a and is an open end 17a, and the second end opposite to the first end is connected to the detection circuit 15.

[0033] As shown in Figure 2, the wires 16 and 17 are twisted cables arranged by twisting them together in a spiral shape. This minimizes the directional difference when touching the area where the wires 16 and 17 are located, while allowing for highly accurate detection of whether or not a user has touched the area. The wires 16 and 17 are also located near the trigger switch 18a in the main body 11.

[0034] As a result, the detection circuit 15 can detect when the user is gripping the main body 11 while operating the trigger switch 18a with their right hand, as shown in Figure 1. In other words, when the gripping part 12 is gripped, a change in capacitance at the electrode 12a can be detected. On the other hand, when the area around the trigger switch 18a of the main body 11 is gripped, a change in capacitance at the wires 16 and 17 can be detected.

[0035] The drive unit 18 is, for example, an electric motor driven by power supplied from the power supply unit 19, and as shown in Figure 1, is provided on the main body 11 to rotate the grinding wheel (tip tool) 13. The drive unit 18 is driven by the user operating a trigger switch 18a provided on the main body 11. As shown in Figure 1, the trigger switch 18a is provided on the side (rear side in the figure) of the main body 11, and the wires 16 and 17 are arranged in its vicinity. As shown in Figure 1, the power supply unit 19 is detachably attached to the bottom of the main body 11 and supplies power to the drive unit 18. A touch control board 14 (detection circuit 15) is arranged in the vicinity of the power supply unit 19. This makes it possible to shorten the power wiring connecting the power supply unit 19 and the touch control board 14.

[0036] <Touch Detection Processing> In the work tool 10 of this embodiment, the detection circuit 15 detects, as shown in Figure 1, that the user has touched the electrode 12a provided on the gripping part 12 (hand A), and that the user has touched the vicinity of the trigger switch 18a on the main body part 11 (hand B), based on the change in capacitance.

[0037] Here, we will examine the configuration of a comparative example in which only the electric wire 16 is provided, in which, for example, the electrode 12a provided on the gripping portion 12 and the detection circuit 15 are positioned at a distance from each other. In the comparative example configuration in which only the electric wire 16 is provided, as shown in Figure 3(a), when the user touches the electrode 12a provided on the gripping portion 12 (hand A) and when the user touches the vicinity of the trigger switch 18a on the main body portion 11 (hand B), a change in capacitance exceeding the threshold set for touch detection is observed, but the touch detection value (capacitance) changes in the same way.

[0038] Therefore, in the comparative example configuration, it was difficult to determine whether hand A or hand B, as shown in Figure 1, was touching the gripping portion 12 or the main body portion 11. On the other hand, in the work tool 10 of this embodiment, when only hand A, as shown in Figure 1, is gripping the gripping portion 12, a difference occurs between the change in capacitance on the electrode 12a side detected by the detection circuit 15 and the change in capacitance on the electric wires 16 and 17 side, as shown in Figure 3(b).

[0039] On the other hand, when only hand B as shown in Figure 1 is gripping the main body 11, as shown in Figure 3(b), there is almost no difference between the change in capacitance on the electrode 12a side detected by the detection circuit 15 and the change in capacitance on the wires 16 and 17 side. As a result, in the work tool 10 of this embodiment, the electrode 12a of the gripping part 12 and the detection circuit 15 are connected via the wire 16, and the first end of the wire 17, of the wires 16 and 17 provided near the trigger switch 18a of the main body 11, is left as an open end and the second end is connected to the detection circuit 15, thereby making it possible to distinguish between the state in which the gripping part 12 is being gripped and the state in which the main body 11 is being gripped.

[0040] More specifically, the work tool 10 of this embodiment can distinguish between the state in which hand A, as shown in Figure 4(a), is gripping only the gripping portion 12; the state in which hand B, as shown in Figure 4(b), is gripping only the main body portion 11; and the state in which hands A and B, as shown in Figure 4(c), are gripping both the gripping portion 12 and the main body portion 11, respectively. For example, in the state in which hand A, as shown in Figure 4(a), is gripping only the gripping portion 12, the capacitance detected by the detection circuit 15 is such that, as shown in section B of Figure 5, the change in capacitance at electrode 12a is greater than threshold A (first threshold), and the difference with the capacitance at the main body portion 11 (electric wires 16, 17) is greater than or equal to threshold B (second threshold).

[0041] Next, in the state shown in Figure 4(b) where hand B is gripping only the main body 11, the capacitance detected by the detection circuit 15 is such that, as shown in section D of Figure 5, the change in capacitance at electrode 12a is greater than threshold A (first threshold), and the difference with the capacitance at the main body 11 (wires 16, 17) is less than threshold B (second threshold). This is because the wire 16, which is located in the gripping portion of the main body 11 (near the trigger switch 18a), is connected to electrode 12a, so even when the main body 11 is gripped, the same capacitance difference as when electrode 12a is gripped occurs.

[0042] Next, in the state shown in Figure 4(c) where hands A and B are gripping the gripping part 12 and the main body part 11 respectively, the capacitance detected by the detection circuit 15 is such that, as shown in section F of Figure 5, the change in capacitance at electrode 12a and the change in capacitance at the main body part 11 (wires 16, 17) are greater than threshold A (first threshold), and the difference with the capacitance at the main body part 11 (wires 16, 17) is greater than or equal to threshold B (second threshold).

[0043] That is, when the touch control board 14 satisfies the first condition that the detection result in the detection circuit 15 has changed by a threshold value A (first threshold value) or more, and the second condition that the difference between the detection result on the gripping part 12 side and the detection result on the main body part 11 side in the detection circuit 15 is a threshold value B (second threshold value) or more, it is determined that the electrode 12a is touched. Thereby, while avoiding erroneously determining that the electrode 12a is touched even though only the vicinity of the trigger switch 18a in the main body part 11 is touched, it is possible to accurately detect that the gripping part 12 (electrode 12a) is touched.

[0044] In addition, when the touch control board 14 satisfies the third condition that the detection result in the detection circuit 15 has changed by a threshold value A (third threshold value) or more in addition to the first condition and the second condition, it is determined that both a predetermined position in the electrode 12a and the main body part 11 are touched. Thereby, in addition to the first condition and the second condition described above, when it is detected that the detection result on the main body part 11 side in the detection circuit 15 has changed by a threshold value A (third threshold value) or more, it is possible to accurately determine that both the electrode 12a and the vicinity of the trigger switch 18a in the main body part 11 are in a state of being touched.

[0045] Note that the threshold value A (first threshold value, third threshold value) and the threshold value B (second threshold value) can switch the touch sensitivity for detecting that the electrode 12a and the main body part 11 (electric wires 16, 17) are touched by changing the values. More specifically, in the section A shown in FIG. 5, since the working tool 10 is not being touched, as shown in FIG. 6, all of the above-described conditions 1, 2, and 3 are not satisfied, and it becomes "False". Therefore, the touch detection for both the gripping part 12 and the main body part 11 becomes "not detected".

[0046] In section B shown in FIG. 5, as shown in FIG. 6, since it is in a state of touching the gripping portion 12 shown in FIG. 4(a), as shown in FIG. 6, the above-mentioned conditions 1 and 2 are satisfied, condition 1 and 2 are "True", and condition 3 is "False". Therefore, the touch detection on the gripping portion 12 is "detected", and the touch detection on the main body portion 11 and the gripping portion 12 is "not detected". In section C shown in FIG. 5, as shown in FIG. 6, similar to section A, since it is not touching the working tool 10, as shown in FIG. 6, the above-mentioned conditions 1, 2, and 3 are not all satisfied and become "False". Therefore, the touch detections on both the gripping portion 12 and the main body portion 11 are both "not detected".

[0047] In section D shown in FIG. 5, as shown in FIG. 6, since it is only touching near the trigger switch 18a of the main body portion 11 shown in FIG. 4(b), as shown in FIG. 6, the above-mentioned conditions 1 and 3 are satisfied, condition 1 and 3 are "True", and condition 2 is "False". Therefore, the touch detection on the main body portion 11 is "detected", the touch detection on the gripping portion 12 is "not detected", and the touch detection on the main body portion 11 and the gripping portion 12 is "not detected".

[0048] In section E shown in FIG. 5, as shown in FIG. 6, similar to section A, since it is not touching the working tool 10, as shown in FIG. 6, the above-mentioned conditions 1, 2, and 3 are not all satisfied and become "False". Therefore, the touch detections on both the gripping portion 12 and the main body portion 11 are both "not detected". In section F shown in FIG. 5, as shown in FIG. 6, since it is touching both the gripping portion 12 and near the trigger switch 18a of the main body portion 11 shown in FIG. 4(c), as shown in FIG. 6, all of the above-mentioned conditions 1, 2, and 3 are satisfied, and condition 1, 2, and 3 are "True". Therefore, the touch detection on the main body portion 11, the touch detection on the gripping portion 12, and the touch detection on the main body portion 11 and the gripping portion 12 are all "detected".

[0049] In section G shown in Figure 5, as shown in Figure 6, the working tool 10 is not being touched, similar to section A. Therefore, as shown in Figure 6, all of the above conditions 1, 2, and 3 are not met, resulting in "False". Thus, touch detection to both the gripping portion 12 and the main body portion 11 is "not detected". From the above, in the working tool 10 of this embodiment, if the above conditions 1 and 2 are met but condition 3 is not met, the touch control board 14 can determine that only the gripping portion 12 is being gripped.

[0050] Next, if conditions 1 and 3 described above are met but condition 2 is not met, the touch control board 14 can determine that only the area around the trigger switch 18a of the main body 11 is being gripped. If all of conditions 1, 2, and 3 described above are met, the touch control board 14 can determine that both the area around the trigger switch 18a of the main body 11 and the gripping part 12 are being gripped.

[0051] <Main Features> The work tool 10 of this embodiment comprises a main body 11, a gripping part 12, an electrode 12a, an electric wire 16, a detection circuit 15, an electric wire 17, and a touch control board 14. The gripping part 12 is attached to the main body 11 and is gripped by the user when in use. The electrode 12a is provided on the gripping part 12. The electric wire 16 is connected to the electrode 12a provided on the gripping part 12. The detection circuit 15 is provided on the main body 11 and is connected to the electrode 12a via the electric wire 16 to detect when the gripping part 12 is touched by the user. At least a portion of the electric wire 17 is arranged along the electric wire 16 at a predetermined position on the main body 11 and has an open end 17a that is not connected to the electrode 12a. The detection circuit 15 is provided on the main body 11 and is connected to the electric wire 17 to detect when a predetermined position on the main body 11 is touched by the user. The touch control board 14 determines, based on the respective detection results in the detection circuit 15, whether or not the user is touching the gripping portion 12 and whether or not the user is touching a predetermined position on the main body portion 11.

[0052] As a result, for example, if only the gripping part 12 is touched, the wire 17 is not affected, so the detection result in the detection circuit 15 can be used to detect that the gripping part 12 is being touched. Also, if only the area around the trigger switch 18a on the main body 11 is touched, both the wires 16 and 17 are affected, so the detection result in the detection circuit 15 can be used to detect that the area around the trigger switch 18a is being touched. Furthermore, if both the gripping part 12 and the area around the trigger switch 18a on the main body 11 are being touched, the detection result in the detection circuit 15 can be used to detect that the area around the trigger switch 18a is being touched, and the detection circuit 15 can detect a larger change than when only the gripping part 12 is being touched because both the wires 16 and 17 are affected, making it easy to determine that both are being touched.

[0053] As a result, a simple configuration combining a wire 16 connected to the electrode 12a provided on the gripping portion 12 and a wire 17 arranged along the wire 16 near the trigger switch 18a of the main body portion 11 and having an open end 17a makes it possible to determine whether the user has touched the electrode 12a and / or a location other than the electrode 12a.

[0054] [Other Embodiments] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention. (A) In the above embodiment, the vicinity of the trigger switch 18a on the main body 11 was given as an example of a predetermined position on the main body 11 that detects when the user has touched it. However, the present invention is not limited thereto. For example, the predetermined position on the main body that detects when the user has touched it may be a position on the main body that is spaced away from the trigger switch and is held when in use.

[0055] (B) In the above embodiment, an example was given in which electric wires were used as the first electrical component (electric wire 16) and the second electrical component (electric wire 17). However, the present invention is not limited thereto. For example, the first electrical component and the second electrical component may be other components such as elongated electrodes instead of electric wires.

[0056] (C) In the above embodiment, an example was described in which the first threshold for detecting touch on the gripping portion 12 side and the third threshold for detecting touch on the main body portion 11 (electric wires 16, 17) side are set to the same value (threshold A in Figure 5). However, the present invention is not limited thereto. For example, the first threshold and the third threshold may be set to different values ​​to perform touch detection.

[0057] (D) In ​​the above embodiment, an example was given in which touch to a predetermined position on the main body 11, on which the electrodes 12a and wires 16 and 17 are provided, is detected from the change in capacitance detected in the electrodes 12a and wires 16 and 17. However, the present invention is not limited thereto. For example, a configuration may be used to detect touch to a predetermined position on the electrodes and main body based on detection results other than capacitance.

[0058] (E) In the above embodiment, an example was given in which the gripping portion 12 is detachably attached to both the left and right sides of the main body portion 11 according to the user's dominant hand. However, the present invention is not limited thereto. For example, the gripping portion may be configured to be attached to only one side of the main body portion, or it may be configured to be fixed to the main body portion in a non-detachable manner.

[0059] (F) In the above embodiment, an example in which the present invention is applied to a grinder as the work tool 10 was described. However, the present invention is not limited thereto. For example, the present invention may be applied to work tools other than grinders, such as jigsaws, chainsaws, and electric screwdrivers, which drive the tip tools to perform various tasks.

[0060] (G) In the above embodiment, a work tool 10 that rotates the drive unit 18 by power from the power supply unit 19 was described as an example. However, the present invention may also be applied to work tools that are driven using forces other than electricity, such as pneumatic pressure.

[0061] <Note> The work tool according to the first invention comprises: a main body; a gripping portion attached to the main body and gripped by the user when in use; an electrode provided on the gripping portion; a first electrical component connected to the electrode provided on the gripping portion; a first detection circuit provided on the main body and connected to the electrode via the first electrical component, which detects that the gripping portion has been touched by the user; a second electrical component having an open end that is not connected to the electrode and at least a portion of which is positioned along the first electrical component at a predetermined position on the main body; a second detection circuit provided on the main body and connected to the second electrical component, which detects that a predetermined position on the main body has been touched by the user; and a control unit that, based on the detection results of the first detection circuit and the second detection circuit, performs at least one of the following: determining whether the gripping portion has been touched by the user and determining whether the predetermined position on the main body has been touched by the user.

[0062] The work tool according to the second invention is the same as the work tool according to the first invention, wherein the control unit determines that the gripping portion is being touched when the first condition is met, which is that the detection result in the first detection circuit has changed by a first threshold or more, and the second condition is met, which is that the difference between the detection result in the first detection circuit and the detection result in the second detection circuit is equal to or greater than a second threshold.

[0063] The work tool according to the third invention is the work tool according to the second invention, wherein the control unit determines that both the gripping portion and the predetermined position on the main body are being touched if, in addition to the first and second conditions, a third condition is met in which the detection result in the second detection circuit has changed by a third threshold or more. The work tool according to the fourth invention is the work tool according to any one of the first to third inventions, further comprising: a drive unit provided on the main body for driving the tip tool; and a trigger switch provided on the main body for being operated by the user to drive the drive unit, wherein the first electrical component and the second electrical component are arranged near the trigger switch provided on the main body.

[0064] The working tool according to the fifth invention is the working tool according to the second invention, wherein the sensitivity for detecting contact with the gripping portion, the first electrical component, and the second electrical component is switched by changing at least one of the first threshold and the second threshold. The working tool according to the sixth invention is the working tool according to any one of the first to fifth inventions, wherein the first electrical component and the second electrical component are made of electric wires.

[0065] The working tool according to the seventh invention is the working tool according to the sixth invention, wherein the first electrical member and the second electrical member are arranged to be twisted together in a spiral manner. The working tool according to the eighth invention is the working tool according to any one of the first to seventh inventions, wherein the first detection circuit is arranged in the main body at a position spaced apart from the gripping portion.

[0066] The ninth invention is a work tool according to the eighth invention, wherein the first detection circuit and the second detection circuit are located near a power supply unit which is attached to the main body in a replaceable manner. The tenth invention is a work tool according to any one of the first to ninth inventions, wherein the first detection circuit and the second detection circuit detect when a user has touched it by a change in capacitance.

[0067] The eleventh invention is a work tool according to any one of the first to tenth inventions, wherein the gripping portion can be attached to the main body in a position that can be changed according to the user's dominant hand. The twelfth invention is a work tool according to any one of the first to eleventh inventions, which is a grinder that polishes, grinds, and cuts an object by rotating a grinding wheel attached to the main body.

[0068] The present invention provides the advantage of being able to determine whether the user has touched the gripping part or / or another part of the tool, as the control unit for detecting when the user touches the gripping part is positioned at a distance from the gripping part. Therefore, it is widely applicable to various work tools that are recommended to be used while being held with both hands.

[0069] 10. Working tool 11. Main body 12. Gripping part 12a. Electrode 13. Grinding wheel (tip tool) 14. Touch control board (control unit) 15. Detection circuit (first detection circuit, second detection circuit) 16. Electric wire (first electrical component) 17. Electric wire (second electrical component) 17a. Open end 18. Drive unit 18a. Trigger switch 19. Power supply unit

Claims

1. A work tool comprising: a main body; a gripping portion attached to the main body and gripped by the user during use; an electrode provided on the gripping portion; a first electrical component connected to the electrode provided on the gripping portion; a first detection circuit provided on the main body and connected to the electrode via the first electrical component, for detecting when the gripping portion is touched by the user; a second electrical component having an open end that is not connected to the electrode and at least a portion of which is positioned along the first electrical component at a predetermined position on the main body; a second detection circuit provided on the main body and connected to the second electrical component, for detecting when a predetermined position on the main body is touched by the user; and a control unit that, based on the detection results of the first and second detection circuits, determines whether the gripping portion is touched by the user and whether the predetermined position on the main body is touched by the user, or at least one of these.

2. The work tool according to claim 1, wherein the control unit determines that the gripping portion is being touched when it satisfies a first condition that the detection result in the first detection circuit has changed by a first threshold or more, and a second condition that the difference between the detection result in the first detection circuit and the detection result in the second detection circuit is equal to or greater than a second threshold.

3. The work tool according to claim 2, wherein the control unit determines that both the gripping portion and the main body portion are being touched if, in addition to the first and second conditions, a third condition is met in which the detection result in the second detection circuit has changed by a third threshold or more.

4. The work tool according to claim 1 or 2, further comprising: a drive unit provided in the main body for driving a tip tool; and a trigger switch provided in the main body for being operated by a user to drive the drive unit, wherein the first electrical component and the second electrical component are arranged near the trigger switch provided in the main body.

5. The work tool according to claim 2, wherein the sensitivity for detecting contact with the gripping portion, the first electrical component, and the second electrical component is switched by changing at least one of the first threshold and the second threshold.

6. The work tool according to claim 1 or 2, wherein the first electrical component and the second electrical component are made of electric wires.

7. The work tool according to claim 6, wherein the first electrical member and the second electrical member are arranged to be twisted together in a spiral manner.

8. The work tool according to claim 1 or 2, wherein the first detection circuit is located in the main body at a position spaced apart from the gripping portion.

9. The work tool according to claim 8, wherein the first detection circuit and the second detection circuit are located near a power supply unit that is attached to the main body in a replaceable manner.

10. The first detection circuit and the second detection circuit detect when a user touches the tool by a change in capacitance, as described in claim 1 or 2.

11. The work tool according to claim 1 or 2, wherein the attachment position of the gripping portion to the main body portion can be changed according to the user's dominant hand.

12. A grinder that polishes, grinds, and cuts an object by rotating a grinding wheel attached to the main body, according to claim 1 or 2.

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