Driving tool

Abstract

A drive tool (11) according to the present invention is provided with a drive unit (18), an endless machining belt (52) configured to be rotated by the drive unit (18) and press workpieces (53, 64) to machine the workpieces (53, 64), a tension application unit (32, 43) configured to apply tension to the machining belt (52), a detection unit (39, 54) configured to detect the pressing force of the machining belt (52) against the workpieces (53, 64), and a display unit (26) configured to display the pressing force on the workpieces (53, 64). The display unit (26) is configured so as to display the pressing force detected by the detection units (39, 54).

Description

Technical Field

[0001] The present disclosure relates to a driving tool including an endless processing belt that is rotationally driven by a driving portion and presses a workpiece to process the workpiece. Background Art

[0002] Conventional drive tools of this type include a DC battery-powered handheld tool such as that described in Patent Document 1. This drive tool utilizes an endless belt driven by an electric motor to press a workpiece, thereby processing the workpiece. The drive tool is equipped with a display that indicates the remaining capacity of the DC battery and the overload status.

[0003] Prior art literature Patent Literature Patent Document 1: Japanese Utility Model Application Laid-Open No. 4-102783 Summary of the Invention Technical issues to be solved by the invention

[0004] In the driving tool disclosed in Japanese Utility Model Application Laid-Open No. 4-102783, the user cannot perceive the pressing force generated when the endless belt, which is rotationally driven by the electric motor, presses the workpiece. This is disadvantageous in improving the machining accuracy of the workpiece. Technical solutions adopted to solve technical problems

[0005] A driving tool in one form disclosed herein comprises a driving portion, an endless processing belt, a tension imparting portion, a detection portion, and a display portion. The processing belt is configured to be rotated by the driving portion and to squeeze a workpiece to thereby process the workpiece. The tension imparting portion is configured to impart tension to the processing belt. The detection portion is configured to detect the squeezing force of the processing belt on the workpiece. The display portion is configured to display the squeezing force detected by the detection portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 This is a perspective view of a driving tool according to one embodiment. Figure 2 Yes Figure 1 A three-dimensional view of a driving tool in which a housing cover is removed. Figure 3 Yes Figure 1 Schematic diagram of the structure surrounding the pneumatic motor inside the driving tool. Figure 4 Yes Figure 1 A side sectional view of the main parts of the driving tool. Figure 5 Yes Figure 1 A top sectional view of the main parts of the driving tool. Figure 6Yes Figure 1 Block diagram of the electrical structure of the drive tool. Figure 7 It is a side sectional view of the driving tool according to the first modified example. Figure 8 It is a schematic diagram showing the main part of the functional section of the driving tool according to the second modified example. Figure 9 It is a schematic diagram showing the main part of the functional section of the driving tool according to the third modified example. Figure 10 It is a side sectional view showing the main part of the driving tool according to the fourth modified example. Figure 11 It is a side sectional view showing the main part of the driving tool according to the fifth modified example. DETAILED DESCRIPTION

[0007] Hereinafter, one embodiment of a driving tool will be described with reference to the drawings. <Drive tool 11> like Figure 1 As shown, the driving tool 11 is, for example, a belt sander. The driving tool 11 has a straight-line extending shape. The driving tool 11 includes a grip portion 12 for a user to grip during use and a functional portion 13 that functions as a tool.

[0008] In the following description, Figure 1 The direction in which the driving tool 11 extends is defined as the X direction. The direction facing the distal end of the functional portion 13 is defined as the forward direction, the left-right direction is defined as the Y direction, and the vertical direction (vertical direction) is defined as the Z direction. The X, Y, and Z directions are mutually orthogonal. In the driving tool 11 of this embodiment, the grip portion 12 and the functional portion 13 both extend in the X direction. The distal end of the grip portion 12 is connected to the proximal end of the functional portion 13.

[0009] <Grip 12> like Figure 2 and Figure 3 As shown, the gripping portion 12 includes a cylindrical first gripping portion 14 and a second gripping portion 15. The base end of the gripping portion 12 is the second gripping portion 15. The second gripping portion 15 is rotatably connected to the first gripping portion 14 about an axis extending in the X direction. A connecting pipe 16 is provided at the end of the second gripping portion 15 opposite the first gripping portion 14. This connecting pipe 16 is connected to the front end of an air hose extending from an air compressor. The air compressor and air hose are not shown.

[0010] A main valve 17 is arranged in the second gripping portion 15. The main valve 17 is connected to the first end of the connecting tube 16. The second end of the connecting tube 16 is connected to the front end of the above-mentioned air hose. The main valve 17 is configured to be able to be opened and closed by rotating the second gripping portion 15 in both clockwise and counterclockwise directions relative to the first gripping portion 14. A pneumatic motor 18 and an air flow control valve 19 are arranged side by side in the X direction in the first gripping portion 14, wherein the pneumatic motor 18 serves as an example of a driving portion, and the air flow control valve 19 adjusts the flow rate of compressed air supplied to the pneumatic motor 18. The pneumatic motor 18 is a motor driven by the supply of compressed air.

[0011] The air flow control valve 19 is located between the pneumatic motor 18 and the main valve 17. The main valve 17 and the air flow control valve 19 are connected to each other via a first connecting pipe 20. The pneumatic motor 18 and the air flow control valve 19 are connected to each other via a second connecting pipe 21. An output shaft 22 is provided at the end of the pneumatic motor 18 adjacent to the functional unit 13. This output shaft 22 protrudes toward the functional unit 13.

[0012] <Functional section 13> like Figures 1 to 3 As shown, the functional portion 13 has a housing 23, which is located on the base end side of the functional portion 13. A housing opening 24 is formed at one end of the housing 23 in the X direction. The other end of the housing 23 in the X direction is connected to the first gripping portion 14, that is, the front end of the gripping portion 12. The housing 23 has a plate-shaped cover 25, which is configured to be freely attached to and detached from one end in the Y direction. A display portion 26 is provided on the upper surface of the housing 23 in the Z direction. A rotating shaft 27 extending in the Y direction is arranged near the first gripping portion 14 in the housing 23.

[0013] The rotating shaft 27 is rotatably supported by the housing 23. The rotating shaft 27 has a first end and a second end in the Y direction. The first end is located closer to the first gripping portion 14, and the second end is located farther from the first gripping portion 14. A first bevel gear 28 is provided at the first end of the rotating shaft 27. This first bevel gear 28 rotates integrally with the rotating shaft 27 about an axis extending in the Y direction. A drive pulley 29 is provided at the second end of the rotating shaft 27. This drive pulley 29 rotates integrally with the rotating shaft 27 about an axis extending in the Y direction. The drive pulley 29 is offset from the first gripping portion 14 in the Y direction.

[0014] A second bevel gear 30 is disposed within the housing 23. This second bevel gear 30 is provided at the distal end of the output shaft 22 of the pneumatic motor 18 and meshes with the first bevel gear 28. The second bevel gear 30 has fewer teeth than the first bevel gear 28. The second bevel gear 30 rotates integrally with the output shaft 22 about an axis extending in the X direction.

[0015] When compressed air is supplied from the air compressor to the pneumatic motor 18 via the air hose and connecting tube 16, the output shaft 22 and the second bevel gear 30 rotate integrally about an axis extending in the X direction. In this way, the rotational force of the second bevel gear 30 is transmitted to the rotating shaft 27 via the first bevel gear 28. As a result, the rotating shaft 27, the first bevel gear 28, and the drive pulley 29 rotate integrally about an axis extending in the Y direction. In this embodiment, because the second bevel gear 30 has fewer teeth than the first bevel gear 28, the rotation speed of the first bevel gear 28 is slower than that of the second bevel gear 30.

[0016] like Figure 2 and Figure 4 As shown, a support cylinder 31 extending in the X direction is fixed to a position within the housing 23, some distance from the drive pulley 29 toward the housing opening 24. The support cylinder 31 is arranged side by side with the drive pulley 29 in the X direction. Approximately half of the base end of the support cylinder 31 is located within the housing 23, and the distal end of the support cylinder 31 protrudes from the housing opening 24 toward the outside of the housing 23. A sliding member 32, serving as an example of a displacement unit, is inserted into the support cylinder 31 and is capable of sliding in the X direction. The sliding member 32 is rod-shaped and extends in the X direction.

[0017] like Figure 4 and Figure 5 As shown, the length of the sliding member 32 in the X direction is set, for example, to be approximately twice the length of the support tube 31 in the X direction. The support tube 31 has a first end and a second end in the X direction, with the first end being closer to the drive pulley 29 and the second end being opposite the first end. The support tube 31 includes a first tubular portion 33, a second tubular portion 34, and a third tubular portion 35, each having an inner diameter that gradually increases from the first end toward the second end.

[0018] Specifically, the inner diameter of the first cylindrical portion 33 is smaller than the inner diameter of the second cylindrical portion 34, and the inner diameter of the second cylindrical portion 34 is smaller than the inner diameter of the third cylindrical portion 35. The length of the first cylindrical portion 33 in the X direction is smaller than the length of the second cylindrical portion 34 in the X direction. The length of the second cylindrical portion 34 in the X direction is smaller than the length of the third cylindrical portion 35 in the X direction.

[0019] A cylindrical first sleeve 36 is provided on the inner surface of the first cylindrical portion 33. A cylindrical pad 37 is provided on the inner surface of the second cylindrical portion 34 at the end adjacent to the first cylindrical portion 33. The inner diameter of the first sleeve 36 is the same as the inner diameter of the pad 37. A second sleeve 38 is provided at each of the two ends in the X direction of the inner surface of the third cylindrical portion 35. The inner diameter of the second sleeve 38 is larger than the inner diameters of the first sleeve 36 and the pad 37.

[0020] A displacement sensor 39 is provided on the inner surface of the third cylindrical portion 35 at the center in the X direction. This displacement sensor 39 detects the displacement of the sliding member 32 in the X direction. The inner surface of the displacement sensor 39 facing the sliding member 32 is located radially outward of the inner surface of the second sleeve 38 relative to the central axis of the sliding member 32. Therefore, the displacement sensor 39 does not contact the sliding member 32.

[0021] like Figure 4 and Figure 5 As shown, the sliding member 32 includes a cylindrical first sliding portion 40 and a cylindrical second sliding portion 41. The first sliding portion 40 is inserted into the first cylindrical portion 33 and the second cylindrical portion 34, and the second sliding portion 41 is inserted into the third cylindrical portion 35. The first sliding portion 40 is guided by the first sleeve 36 and the pad 37, and the second sliding portion 41 is guided by the two second sleeves 38. The outer diameter of the first sliding portion 40 is smaller than the outer diameter of the second sliding portion 41.

[0022] A step 42 is formed at the boundary between the first sliding portion 40 and the second sliding portion 41. A coil spring 43 is placed within the second cylindrical portion 34 and is slightly compressed by being inserted through the first sliding portion 40. One end of the coil spring 43 in the X direction contacts the pad 37, while the other end contacts the step 42. Therefore, the coil spring 43 constantly urges the sliding member 32 forward at the step 42.

[0023] The end of the first sliding portion 40, closest to the drive pulley 29, is a protrusion 44 that penetrates the first cylindrical portion 33 and protrudes toward the drive pulley 29. A cylindrical restricting portion 45 is fixed to the protrusion 44 to maintain a fitted state. The outer diameter of the restricting portion 45 is larger than the inner diameter of the first cylindrical portion 33. The restricting portion 45 contacts the end surface of the first end portion of the support cylinder 31, thereby restricting further forward movement of the sliding member 32.

[0024] A rectangular block portion 46 extending in the X-direction is provided at the end of the second sliding portion 41 opposite the drive pulley 29. A plate-shaped protective pad 47 is provided on the lower surface of the block portion 46 in the Z-direction. A shaft support portion 49 is provided at the end of the block portion 46 opposite the drive pulley 29. This shaft support portion 49 supports a shaft 48 extending in the Y-direction. The shaft 48 is provided with a driven pulley 51 via a bearing 50, and is rotatable about its axis extending in the Y-direction.

[0025] The outer diameter of the driven pulley 51 is smaller than that of the driving pulley 29. The driven pulley 51 is arranged parallel to the driving pulley 29 in the X direction. A grinding belt 52, an example of an endless processing belt, is wound around the driven pulley 51 and the driving pulley 29. The grinding belt 52 is made of, for example, sandpaper. The outer surface of the grinding belt 52 serves as a grinding surface.

[0026] like Figures 3 to 5 As shown, when the driving pulley 29 is rotated by the pneumatic motor 18, the grinding belt 52 rotates along the outer circumferences of the driven pulley 51 and the driving pulley 29. While rotating, the grinding belt 52 presses against the workpiece 53 via the grinding surface corresponding to the protection pad 47, thereby grinding the workpiece 53. When pressing against the workpiece 53, the grinding belt 52 receives the reaction force from the workpiece 53 and is pushed inward.

[0027] In this embodiment, the polishing belt 52 has little elasticity. Therefore, the aforementioned reaction force acts as follows: the polishing belt 52 causes the sliding member 32 to move rearward against the biasing force of the coil spring 43. Specifically, the sliding member 32 moves toward the drive pulley 29 in response to the reaction force generated by the polishing belt 52 pressing against the workpiece 53.

[0028] Therefore, the greater the pressing force of the grinding belt 52 on the workpiece 53, the greater the displacement of the sliding member 32 toward the drive pulley 29. Therefore, the pressing force of the grinding belt 52 on the workpiece 53 can be detected based on the displacement of the sliding member 32 toward the drive pulley 29.

[0029] The sliding member 32 applies the biasing force of the coil spring 43 to the polishing tape 52 via the driven pulley 51 as tension for the polishing tape 52. Therefore, in this embodiment, the tension applying portion for applying tension to the polishing tape 52 is composed of the sliding member 32 and the coil spring 43.

[0030] <Electrical Structure of Driving Tool 11> like Figure 6 As shown, the driving tool 11 includes a control unit 54 that performs overall control of the driving tool 11. The control unit 54 is composed of a computer. The control unit 54 includes a CPU, ROM, and RAM, which are not shown. The ROM stores setting values ​​(threshold values), various information, programs, etc., which will be described later. The RAM temporarily stores various data such as the calculation results and processing results of the CPU. The control unit 54 can also be composed of a hardware circuit such as an ASIC (Application Specific Integrated Circuit). The control unit 54 of the processing circuit can include one or more processors that operate according to a computer program, one or more hardware circuits such as an ASIC, or a combination of these.

[0031] An input interface (not shown) of the control unit 54 is electrically connected to the displacement sensor 39. An output interface (not shown) of the control unit 54 is electrically connected to the display unit 26 and the air flow control valve 19. The control unit 54 calculates the pressing force of the polishing tape 52 on the workpiece 53 based on the signal output from the displacement sensor 39 and displays the calculated pressing force on the display unit 26.

[0032] like Figure 1 As shown, the display unit 26 displays the pressing force analogically, i.e., continuously, using a measuring rod ranging from 0 to 100. In this embodiment, the control unit 54 and the displacement sensor 39 constitute a detection unit for detecting the pressing force of the polishing belt 52 on the workpiece 53.

[0033] The control unit 54 controls the air flow control valve 19 based on the calculated extrusion force, thereby controlling the driving of the air motor 18. Specifically, the control unit 54 controls the air flow control valve 19 to adjust the flow rate of compressed air supplied to the air motor 18, thereby adjusting the output of the air motor 18. When the extrusion force exceeds the set value (threshold), the control unit 54 controls the air flow control valve 19 to reduce the output of the air motor 18. For example, if the set value (threshold) is set to 100 and the extrusion force exceeds 100, the control unit 54 reduces the output of the air motor 18.

[0034] <Function of the driving tool 11> like Figure 3 and Figure 4 As shown, when compressed air from an air compressor (not shown) is supplied to the pneumatic motor 18, the output shaft 22 of the pneumatic motor 18 rotates integrally with the second bevel gear 30. As the second bevel gear 30 rotates, the rotational force of the second bevel gear 30 is transmitted to the first bevel gear 28, causing the first bevel gear 28, the rotating shaft 27, and the drive pulley 29 to rotate integrally. In this manner, the polishing belt 52 rotates along the outer circumferential surfaces of the driven pulley 51 and the drive pulley 29.

[0035] In this state, the grip 12 of the driving tool 11 is held and the polishing surface of the polishing tape 52 corresponding to the protection pad 47 is pressed against the workpiece 53. The polishing surface of the polishing tape 52 then polishes the workpiece 53. At this time, the inner surface of the polishing tape 52 slides against the protection pad 47.

[0036] Furthermore, the display unit 26 displays the pressing force of the grinding tape 52 on the workpiece 53 in real time. Therefore, the user can grind the workpiece 53 while visually observing the display unit 26. In this way, the user can easily maintain the pressing force of the grinding tape 52 on the workpiece 53 at an optimal level, thereby enabling the workpiece 53 to be ground with higher precision.

[0037] Furthermore, if the rotating grinding belt 52 presses the workpiece 53 too hard, and the pressing force of the grinding belt 52 on the workpiece 53 exceeds a set value (threshold), the output of the air motor 18 is reduced. This can thereby suppress excessive loads on the air motor 18 and the grinding belt 52.

[0038] <Effects of implementation> According to the embodiment described in detail above, the following effects can be achieved. (1) The driving tool 11 includes a driving portion, an endless grinding belt 52, a tension imparting portion, a detection portion, and a display portion. The grinding belt 52 is rotated by the driving portion and presses the workpiece 53 to grind the workpiece 53. The tension imparting portion imparts tension to the grinding belt 52. The detection portion detects the pressing force of the grinding belt 52 on the workpiece 53. The display portion 26 displays the pressing force detected by the detection portion.

[0039] According to the above configuration, since the display unit 26 displays the pressing force of the grinding tape 52 on the workpiece 53, the user can perform the grinding operation on the workpiece 53 while visually observing the pressing force of the grinding tape 52 on the workpiece 53. Therefore, since the user can easily maintain the pressing force of the grinding tape 52 on the workpiece 53 at an optimal state, the workpiece 53 can be ground with higher precision.

[0040] (2) In the driving tool 11, the tension applying portion includes the sliding member 32, which is displaced by the reaction force generated when the polishing tape 52 presses the workpiece 53. The detecting portion detects the pressing force based on the displacement of the sliding member 32.

[0041] According to the above configuration, since the detection portion detects the pressing force based on the displacement amount of the sliding member 32 , the pressing force can be detected with high accuracy using a relatively simple configuration. (3) The driving tool 11 includes a control unit 54 that controls the driving of the driving unit based on the pressing force detected by the detection unit. When the pressing force exceeds a set value (threshold), the control unit 54 reduces the output of the driving unit.

[0042] According to the above configuration, when the pressing force exceeds a set value (threshold value), the output of the driving unit is reduced, thereby suppressing excessive burden on the driving unit, the polishing tape 52, and the like.

[0043] (4) In the driving tool 11 , the driving portion is constituted by the pneumatic motor 18 . According to the above configuration, the output of the driving unit can be increased compared to a case where the driving unit is constituted by an electric motor.

[0044] <Change Example> The above embodiment can also be implemented with modifications as follows: The above embodiment and the following modifications can be implemented in combination with each other within the scope of no technical contradiction.

[0045] like Figure 7As shown, a detachable auxiliary passive pulley unit 60 may be provided on the lower surface of the support cylinder 31 in the Z direction. The auxiliary passive pulley unit 60 includes a shaft 61 extending in the Y direction, a shaft support portion 62 supporting the shaft 61, and an auxiliary passive pulley 63 rotatable along the shaft 61 and supported by the shaft 61. The auxiliary passive pulley 63 contacts the inner surface of the polishing belt 52.

[0046] This increases the distance between the polishing tape 52 and the protective pad 47, making it easier for the polishing tape 52 to follow a circular or curved workpiece 64. This makes polishing a circular or curved workpiece 64 easier. If the auxiliary driven pulley unit 60 is no longer needed, it can simply be removed from the support cylinder 31.

[0047] like Figure 8 As shown, a displacement sensor 70 may be used instead of the displacement sensor 39, and the functional portion 13 may be configured as follows. Specifically, the functional portion 13 is divided into two parts, namely a first functional portion 65 and a second functional portion 66, wherein the first functional portion 65 includes the drive pulley 29 and the second functional portion 66 is located closer to the front end side than the first functional portion 65. The first functional portion 65 and the second functional portion 66 are rotatably connected by a shaft 67 located in the center of the Z direction and extending in the Y direction. A gap 68 is formed between the first functional portion 65 and the second functional portion 66. The first functional portion 65 and the second functional portion 66 are connected by a spring 69 on the lower side of the shaft 67 in the Z direction. The first functional portion 65 is provided with a displacement sensor 70 on the upper side of the shaft 67 in the Z direction for detecting the width of the gap 68.

[0048] In this way, if the grinding belt 52 presses the workpiece 53, Figure 8 A reaction force in the direction indicated by the arrow acts on the second functional portion 66. In this way, since the second functional portion 66 rotates via the shaft 67 against the biasing force of the spring 69, the spring 69 elastically deforms and the width of the portion of the gap 68 corresponding to the displacement sensor 70 becomes narrower. The degree to which the width of the gap 68 has narrowed, that is, the displacement of the second functional portion 66, is detected by the displacement sensor 70. Then, a signal indicating the degree to which the width of the gap 68 has narrowed is output from the displacement sensor 70 to the control unit 54. In this way, the control unit 54 calculates the pressing force of the grinding tape 52 on the workpiece 53 based on the signal output from the displacement sensor 70, and displays the calculated pressing force on the display unit 26. If the grinding tape 52 leaves the workpiece 53, the elastic restoring force of the spring 69 returns the second functional portion 66 to its original position before rotation.

[0049] like Figure 9 As shown above Figure 8In the functional portion 13 , a pressure sensor 71 may be arranged above the shaft 67 in the gap 68 instead of the displacement sensor 70 . In this way, if the grinding belt 52 presses the workpiece 53, Figure 9 A reaction force in the direction indicated by the arrow acts on the second functional portion 66. In this way, as the second functional portion 66 rotates via the shaft 67 against the biasing force of the spring 69, the spring 69 elastically deforms, and the width of the portion of the gap 68 corresponding to the pressure sensor 71 narrows. As the width of the gap 68 narrows, the pressure applied to the pressure sensor 71 by the second functional portion 66 is detected by the pressure sensor 71 and output as a signal from the pressure sensor 71 to the control unit 54. In this way, the control unit 54 calculates the pressing force of the polishing tape 52 on the workpiece 53 based on the signal output from the pressure sensor 71 and displays this calculated pressing force on the display unit 26. If the polishing tape 52 separates from the workpiece 53, the elastic restoring force of the spring 69 returns the second functional portion 66 to its original position before rotation.

[0050] like Figure 10 As shown, a pressure sensor 72 may be disposed adjacent to the inner side surface of the protection pad 47 instead of the displacement sensor 39 . In this manner, the pressure generated when the polishing tape 52 presses the workpiece 53 is detected by the pressure sensor 72. The control unit 54 calculates the pressing force of the polishing tape 52 on the workpiece 53 based on the signal output from the pressure sensor 72.

[0051] like Figure 11 As shown, a pressure sensor 73 can also be used instead of the displacement sensor 39. In this case, the entire first gripping portion 14 is covered by a cylindrical gripping portion cover 74. The length of the gripping portion cover 74 in the X direction is approximately the same as that of the first gripping portion 14. At both ends of the first gripping portion 14 in the X direction, elastic cylindrical spacers 75 are respectively placed between the first gripping portion 14 and the gripping portion cover 74. The inner surface of the spacer 75 is in contact with the outer surface of the first gripping portion 14, and the outer surface of the spacer 75 is in contact with the inner surface of the gripping portion cover 74. A plate-shaped protrusion 76 protruding inward is provided on the inner surface of the gripping portion cover 74 at the center in the X direction and on the side opposite to the protection pad 47 in the Z direction, that is, on the upper side. A plate-shaped pressure sensor 73 is arranged between the front end surface of the protrusion 76 and the outer surface of the first gripping portion 14. One surface of the pressure sensor 73 is in contact with the front end surface of the convex portion 76 , and the other surface is in contact with the outer surface of the first gripping portion 14 .

[0052] In this manner, when the polishing tape 52 is pressed against the workpiece 53, the spacer 75 elastically deforms, and the pressure sensor 73 is pressed against the protrusion 76. In this manner, the pressure generated when the polishing tape 52 is pressed against the workpiece 53 is detected by the pressure sensor 73. The control unit 54 calculates the pressing force of the polishing tape 52 against the workpiece 53 based on the signal output from the pressure sensor 73.

[0053] When the extrusion force exceeds the set value (threshold), the control unit 54 may control the air flow control valve 19 to stop driving the air motor 18. At this time, since the air flow control valve 19 is completely closed, the flow rate of compressed air passing through the air flow control valve 19 becomes zero, and thus compressed air is not supplied to the air motor 18 at all.

[0054] The pressing force of the polishing tape 52 on the workpiece 53 is not only displayed on the display unit 26 , but can also be notified to the user by making the display unit 26 illuminate or emit a sound such as a buzzer or melody.

[0055] The display unit 26 can also digitally display the pressing force of the grinding belt 52 on the workpiece 53, that is, display it in stages. The direction of the display unit 26 can also be changed.

[0056] The tension applying portion may also include a locking mechanism that can lock the sliding member 32 while it is moving in the X direction, thereby bringing the driven pulley 51 closer to the driving pulley 29. In this way, the polishing tape 52 can be replaced in a loose state, making it easy to replace the polishing tape 52.

[0057] The driving tool 11 may also include an input unit for the user to input and set the setting value (threshold value). In this way, the user can arbitrarily change the setting value (threshold value).

[0058] The driving unit may also be an electric motor. In this case, the output of the electric motor is adjusted by adjusting the driving current supplied to the electric motor. When the driving of the electric motor is to be stopped, the driving current supplied to the electric motor is simply stopped.

[0059] As long as the driving tool processes the workpiece by pressing the workpiece via a rotationally driven processing belt, a driving tool other than a belt sander may be used. The term "cylindrical" used in this specification refers to any structure having a circular, elliptical, or polygonal cross-sectional shape having an acute or obtuse angle, but is not limited thereto.

Claims

1. A driving tool comprising a driving unit, an endless processing belt, a tension applying unit, a detecting unit, and a display unit. The processing belt is configured to be rotated by the driving unit and press the workpiece to process the workpiece. The tension applying portion is configured to apply tension to the processing belt. The detection unit is configured to detect the pressing force of the processing belt on the workpiece. The display unit is configured to display the pressing force detected by the detection unit.

2. The driving tool according to claim 1, wherein The tension applying portion includes a displacement portion configured to be displaced by a reaction force generated when the processing belt presses the workpiece. The detection unit is configured to detect the pressing force based on a displacement amount of the displacement unit.

3. The driving tool according to claim 1 or claim 2, wherein: A control unit is provided, which is configured to control the driving of the driving unit according to the pressing force detected by the detection unit, The control unit is configured to reduce the output of the driving unit or stop driving the driving unit when the pressing force exceeds a set value.

4. The driving tool according to any one of claims 1 to 3, wherein: The driving unit is composed of a pneumatic motor.

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