EP4667161A1 - Working machine - Google Patents

Abstract

Workability of a working machine is improved. An electric tool 400 includes a motor, a clamp shaft 412, a clamp lever 62, and a tool holding section 430. The tool holding section 430 includes clamps 438 and 448 and an attachment seat 452. Even if an operation force on the clamp lever 62 is released, the tool holding section 430 can be brought into either a fixing state or a temporarily holding state. The temporarily holding state includes a first state and at least one of a second state and a third state. In the first state, rotation of a tip tool 402 and detachment of the tip tool 402 are restricted. In the second state, while the detachment of the tip tool 402 is restricted, the tip tool 402 can be rotated from one rotation position to another rotation position. In the third state, at least one of the attachment of the tip tool 402 to the tool holding section 430 and the detachment of the tip tool 402 from the tool holding section 430 is enabled.

Description

TECHNICAL FIELD
• The present invention relates to a working machine.
BACKGROUND ART
• An electric tool described in Patent Document 1 includes a tool shaft for sandwiching a tip tool from below, paired clamp members which swing around a pin to restrict up-down movement of the tool shaft, and a clamp lever by which an operator can change a state of the clamp members.
RELATED ART DOCUMENTS PATENT DOCUMENTS
• Patent Document 1: Japanese Patent Application Laid-open Publication No. 2021-16917
• Patent Document 2: U.S. Patent Application Laid-open Publication No. 2008/0190259
SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION
• In working machines to/from each of which a tip tool is detachable or in working machines in each of which orientation of the tip tool is changeable, there is a demand for improvement in workability of the work for attaching and detaching the tip tool or the work for changing the orientation thereof. Further, the working machines have various mechanisms for holding the tip tool. A mechanism described in the Patent Document 1 holds the tip tool such that power of a motor is transmitted to the tip tool by engagement between a concave section in the working machine main body and a convex section in the tip tool. A mechanism described in the Patent Document 2 holds the tip tool such that power of a motor is transmitted to the tip tool by engagement between a plurality of protrusions that are formed in the working machine main body and a plurality of holes in the tip tool.
• In this case, when the tip tool is attached or detached in the mechanism described in the Patent Document 1, an operator needs to perform a work for engaging the tool shaft with the paired clamp members, and thus, the workability is low. Even in the mechanism described in the Patent Document 2, a work for attaching and detaching the tool shaft is also needed, and thus, the workability is low.
• Further, in order to change the rotation position of the tip tool, it is necessary to completely pull out the tool shaft after a lever is operated and then reattach it, or necessary to move the tool shaft to a position preventing the complete pulling out of the tool shaft after the lever is operated, and thus, this work is burdensome, and the workability is low. Further, in order to attach the tip tool, it is necessary to operate the tool shaft, and an operation not for the clamp lever is necessary, and this work is burdensome.
• An objective of the present invention is to provide a working machine with improved workability.
MEANS FOR SOLVING THE PROBLEMS
• A working machine according to an embodiment includes: a motor; an output shaft configured to be rotated and driven around an axial line by the motor; an operation section configured to be operated by an operator; and a tool holding section configured to include a clamp movable in response to movement of the operation section, and an attachment seat for holding a tip tool by sandwiching the tip tool between the attachment seat and the clamp in a clamping direction and configured to be held by the output shaft.
• The tool holding section can be brought into a fixing state or a temporarily holding state, the fixing state being a state in which a biasing force in the clamping direction is applied to the tip tool to fix the tip tool to the tool holding section even if an operation force on the operation section is released, the temporarily holding state being a state in which the biasing force in the clamping direction on the tip tool is weaker than the biasing force of the fixing state.
• In the tool holding section in the fixing state, the tip tool can be held at a plurality of rotation positions around the axial line by the clamp.
• The temporarily holding state includes a first state and at least one of a second state and a third state, the first state being a state in which rotation of the tip tool and detachment of the tip tool from the tool holding section are restricted, the second state and the third state being caused by biasing the tip tool held by the tool holding section in the first state.
• In the second state, while the clamp restricts the detachment of the tip tool from the tool holding section, the tip tool is rotatable from one rotation position of the plurality of rotation positions to another rotation position.
• In the third state, movement of the tip tool along the axial line is permitted while the clamp is held by the output shaft, and at least one of attachment of the tip tool to the tool holding section and the detachment of the tip tool from the tool holding section is enabled by biasing the tip tool to perform switching between the first state and the third state.
EFFECTS OF THE INVENTION
• According to the present invention, the workability of the working machine can be improved.
BRIEF DESCRIPTIONS OF THE DRAWINGS
• [FIG. 1] is a perspective view illustrating an electric tool as a working machine according to a first embodiment.
• [FIG. 2] is a perspective view illustrating a tip tool.
• [FIG. 3] is a cross-sectional view (taken along a line A-A of FIG. 1) illustrating an internal structure of the electric tool.
• [FIG. 4] is a cross-sectional view illustrating a front section of the electric tool of FIG. 3 to be enlarged.
• [FIG. 5] is an explanatory diagram illustrating a push piece.
• [FIG. 6] is a cross-sectional view (taken along a line B-B of FIG. 3) illustrating an internal structure of the front section of the electric tool.
• [FIG. 7] is a perspective view illustrating a unit casing.
• [FIG. 8] is a perspective view illustrating a state in which a first clamp member and a second clamp member are supported by a clamp holder.
• [FIG. 9] is a front view illustrating the first clamp member and the second clamp member when viewed from a right side in a right-left direction.
• [FIG. 10] is a perspective view illustrating the first clamp member.
• [FIG. 11] is a perspective view illustrating the second clamp member.
• [FIG. 12] is an explanatory diagram illustrating a state in which the clamps hold the tip tool.
• [FIG. 13] is an explanatory diagram illustrating a middle state of rotation of the first clamp member and the second clamp member toward a close position by rotation of a clamp lever.
• [FIG. 14] is an explanatory diagram illustrating a state in which the first clamp member and the second clamp member temporarily hold the tip tool.
• [FIG. 15] is an explanatory diagram illustrating a state in which the first clamp member and the second clamp member are at a release position (close position) while the tip tool is detached.
• [FIG. 16] is an explanatory diagram illustrating a state in which the clamp lever returns to a holding state while an O-ring biases the first clamp member and the second clamp member.
• [FIG. 17] is an explanatory diagram illustrating a state in which the first clamp member and the second clamp member are inserted from above into a hole of the tip tool.
• [FIG. 18] is an explanatory diagram illustrating a state in which the first clamp member and the second clamp member temporarily hold the tip tool.
• [FIG. 19] is an explanatory diagram illustrating changes in a position of the clamp relative to the hole of the tip tool when viewed in a clamping direction (up-down direction).
• [FIG. 20] is an explanatory diagram illustrating a state in which the clamp holds the tip tool, according to a modification example of the first embodiment.
• [FIG. 21] is an explanatory diagram illustrating a state in which the clamp temporarily holds the tip tool, according to the modification example of the first embodiment.
• [FIG. 22] is an explanatory diagram illustrating a state in which the clamp is at the release position (close position) while the tip tool is detached, according to the modification example of the first embodiment.
• [FIG. 23] is an explanatory diagram illustrating a temporarily holding state (first state) of an electric tool as a working machine according to a second embodiment.
• [FIG. 24] is an explanatory diagram illustrating a first clamp member, a second clamp member, and the like of FIG. 23 to be enlarged.
• [FIG. 25] is an explanatory diagram (A-A cross-sectional view of FIG. 23) illustrating an arrangement relationship between a tool holding section and a tip tool of FIG. 23.
• [FIG. 26] is an explanatory diagram illustrating a temporarily holding state (second state) of the electric tool of FIG. 23.
• [FIG. 27] is an explanatory diagram (B-B cross-sectional view of FIG. 26 and C-C cross-sectional view of FIG. 27) illustrating a middle state of rotation of the tip tool in the electric tool of FIG. 23.
• [FIG. 28] is an explanatory diagram illustrating an end state of the rotation of the tip tool in the electric tool of FIG. 23.
• [FIG. 29] is an explanatory diagram illustrating a state in which a tip tool is fixed to an electric tool as a working machine according to a third embodiment.
• [FIG. 30] is an explanatory diagram illustrating a temporarily holding state of the electric tool of FIG. 29.
• [FIG. 31] is an explanatory diagram illustrating changes of the tip tool in the electric tool of FIG. 29 from the fixing state to the temporarily holding state (first state) and the temporarily holding state (second state).
• [FIG. 32] is an explanatory diagram (D-D, E-E, and F-F cross-sectional views of FIG. 31) illustrating a change from a state in which protrusions of an attachment seat in the electric tool of FIG. 29 are inserted into through-holes of the tip tool to a state in which the protrusions are detached from the through-holes.
• [FIG. 33] is an explanatory diagram illustrating a state in which a tip tool is fixed to an electric tool as a working machine according to a modification example of the third embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
• First, second, and third embodiments and their modification examples of the present invention will be described below with reference to the drawings. The description will be made in assumption that a direction with front and back arrows is a front-back direction, a direction with right and left arrows is a right-left direction, and a direction with upper and lower arrows is an up-down direction throughout the drawings. The front-back direction, the right-left direction, and the up-down direction are perpendicular to one another.
• A direction in which a clamp holder 126 and clamps 158, 178 (FIG. 4) described later sandwich a tip tool 16 is assumed as a clamping direction. The up-down direction is an exemplary clamping direction. An upper side in the up-down direction is a side at which the tip tool 16 is clamped, and a lower side in the up-down direction is a side at which the clamping of the tip tool 16 is unloaded. Note that the up-down direction described below may be described as clamping direction.
• The front-back direction is an exemplary crossing direction crossing with the clamping direction. A side at which the tip tool 16 is positioned is assumed as front side, and a side at which a battery pack 14 described later is positioned is assumed as back side. The right-left direction is an exemplary axial direction crossing with both the clamping direction and the crossing direction.
[Configuration of First Embodiment]
• FIG. 1 illustrates an electric tool 10 as an exemplary working machine. The electric tool 10 includes an outer housing 12 and the battery pack 14, and is configured such that the tip tool 16 is replaceable with other tip tool. The electric tool 10 is a cordless multifunctional tool which is operated by power of the battery pack 14. The electric tool 10, for example, oscillates the tip tool 16 in a direction indicated by an arrow RW.
• The outer housing 12 serves as an exterior of the electric tool 10. The battery pack 14 is provided to be attachable to and detachable from a back end of the outer housing 12. Although described in detail later, in the electric tool 10, the fixing state, the temporarily holding state, and the release state of the tip tool 16 can be switched by operation for only a clamp lever 62. In the electric tool 10, by the operation for only the clamp lever 62, the fixing state can be switched to the release state, and the release state can be switched to the fixing state.
<Tip Tool>
• As illustrated in FIG. 2, the tip tool 16 is a member extending in the front-back direction, and includes a flat plate 17 at the front side and an attachment 18 at the back side. The flat plate 17 is shaped into a plate shape having a surface along the front-back direction. A blade section 17A is formed at the front end of the flat plate 17.
• The attachment 18 includes a plate 19 and a protrusion 21. The plate 19 is positioned obliquely upward from the flat plate 17. The protrusion 21 protrudes upward from an upper surface of the plate 19. An outer periphery 21A of the protrusion 21 is shaped such that a plurality of concave sections 21B and a plurality of protrusions 21C are alternately arranged in a circumferential direction when viewed from above. An upper wall 22 is formed at an upper end of the protrusion 21.
• The upper wall 22 is shaped into a plate shape with a thickness in the up-down direction. Single hole 24 which penetrates the upper wall 22 in the up-down direction and a plurality of through-holes 26 are formed at the center of the upper wall 22. The hole 24 includes an annular insertion section 25 and four cutouts 27 extending radially outward from the insertion section 25. A clamp member 142 (FIG. 4) described later is inserted into the insertion section 25. The through-holes 26 are arranged circumferentially to be distant from one another on the outer periphery of the upper wall 22.
<Outer Housing>
• FIG. 3 illustrates an internal structure of the electric tool 10. The outer housing 12 is, for example, a resin molded body. The outer housing 12 is shaped into a tubular shape with a central axis along the front-back direction. A lower opening 13 is formed at a lower end of the front side of the outer housing 12. An upper opening 15 is formed at an upper end of the front side of the outer housing 12.
• An upper section of the outer housing 12 is provided with the clamp lever 62 described later and a trigger 61. The trigger 61 is connected to a switch 41. When the trigger 61 is operated by the operator, switching between turning on and off in the switch 41 is performed, thereby performing switching between driving and stopping in a motor 52. An inner housing 32, a control board 40, the switch 41, and the like are housed in the outer housing 12.
<Inner Housing>
• As illustrated in FIG. 4, the inner housing 32 is shaped into a bottomed tubular shape which is opened forward. The inner housing 32 is positioned to be distant from an inner surface of the outer housing 12. The inner housing 32 includes, for example, a motor housing 34, a middle housing 35, and a holder 36. A back end of the middle housing 35 is attached to the motor housing 34. The motor 52 is housed in the motor housing 34.
(Holder)
• The holder 36 is a metallic member made of, for example, aluminum. The holder 36 includes an attachment 37, a tube 38, and a support wall 39. The middle housing 35 is attached to the attachment 37. The tube 38 is closer to the front side than the attachment 37. The tube 38 is shaped into a tubular shape with a central axis along the up-down direction. The support wall 39 is provided at an upper end of the tube 38. The support wall 39 supports both ends of a columnar pin 46 in its axial direction. The axial direction of the pin 46 is along the right-left direction. A ball bearing 42, a needle bearing 43, an oil seal 44, and an output shaft 90 described later are provided in the tube 38.
• The ball bearing 42 is closer to the front side and the upper side than a swing arm 88 described later. The ball bearing 42 and the needle bearing 43 have central axes along the up-down direction, respectively. The ball bearing 42 supports a guide 98 described later to be rotatable around the central axis. The needle bearing 43 is closer to the front side and the lower side than the swing arm 88, and supports a container 94 described later to be rotatable. The oil seal 44 is closer to the lower side than the needle bearing 43. The oil seal 44 seals a space between a lower part of the holder 36 and a lower part of the container 94.
• The outer housing 12 supports the tube 38 via a rubber member 48. In other words, the inner housing 32 is floated from the outer housing 12 when being supported by the outer housing 12 via the rubber member 48. The rubber member 48 is shaped into a C shape when viewed in the up-down direction. When the motor 52 described later operates, the rubber member 48 suppresses propagation of oscillation from the holder 36 to the outer housing 12.
<Motor and Others>
• As illustrated in FIG. 3, the motor 52 is positioned at the center of the outer housing 12 in the front-back direction. The motor 52 is a brushless motor. The motor 52 includes a rotary shaft 53. The rotary shaft 53 extends in the front-back direction. A controller, a switching element, and the like, which control driving of the motor 52, are mounted on the control board 40.
<Clamp Lever>
• As illustrated in FIG. 4, the clamp lever 62 is an exemplary operation section which is operable for the operator. The clamp lever 62 includes a lever main body 63 and a push piece 64. The lever main body 63 includes paired base ends 63A and a grip 63B extending backward from the paired base ends 63A. The paired base ends 63A face each other to be distant from each other in the right-left direction. The push piece 64 is fixed between the paired base ends 63A. In this state, the pin 46 penetrates the push piece 64 and the paired base ends 63A in the right-left direction. In other words, the clamp lever 62 is coupled to the support wall 39 to be rotatable around the pin 46 as a central axis.
• The grip 63B is exposed to the outside of the outer housing 12 through the upper opening 15. Thereby, the operator can operate the clamp lever 62. The grip 63B is rotated around the pin 46 when being gripped by the operator. Regarding the operations for rotating the clamp lever 62 in the following description, an operation for rotating the grip 63B forward is called "release operation", and an operation for rotating the grip 63B backward is called "attachment operation." Regarding the rotation directions of the clamp lever 62, a rotation direction in which the grip 63B moves forward is called "+R" direction, and a rotation direction in which the grip 63B moves backward is called "-R" direction.
• The clamp lever 62 can hold a clamp shaft 112 described later at a third position P3 (FIG. 14) between a first position P1 (FIG. 12) and a second position P2 (FIG. 15). More specifically, the clamp shaft 112 described later is configured to move between the first position P1 and the second position P2 in response to the movement of the clamp lever 62. The clamp lever 62 can be held at a position at which the clamp shaft 112 is at the third position P3 (the temporarily holding position) between the first position P1 and the second position P2. The clamp lever 62 can be held at a position between the fixing position at which the clamp member 142 is clamped and the release position at which the clamp member 142 is unloaded when the operation force on the clamp lever 62 is released in the release state of the clamp member 142 described later.
<Push Piece>
• FIG. 5 illustrates a posture of the push piece 64 when the tip tool 16 (FIG. 1) is fixed in the electric tool 10. The posture of the push piece 64 is changed by the rotation of the clamp lever 62. The push piece 64 is a block-shaped metallic member. The push piece 64 is positioned to be in contact with or distant from an upper end surface 115 of the clamp shaft 112 described later. A contact position of the push piece 64 with the upper end surface 115 is changed by the rotation of the clamp lever 6 rotates.
• The push piece 64 is an exemplary moving section which can move the clamp shaft 112 to the third position P3 (FIG. 14) described later. Additionally, in the electric tool 10, by the rotation of the push piece 64 (the clamp lever 62), the tip tool 16 is switched among the fixing (holding) state, the temporarily holding state and the release state. The push piece 64 includes an outer periphery 65 when viewed in the right-left direction as the axial direction of the pin 46.
• The outer periphery 65 includes a non-contact section 66 which is not in contact with the clamp shaft 112 and a contact section 71 which can be in contact with the clamp shaft 112. The non-contact section 66 has a surface 67 along the front-back direction and a surface 68 along the up-down direction. The contact section 71 has a first surface 72, a curved surface 73, and a second surface 74. Additionally, the +R direction corresponds to a rotation direction of the push piece 64 in detachment of the tip tool 16. The -R direction corresponds to a rotation direction of the push piece 64 in attachment of the tip tool 16.
• The surface 68, the first surface 72, the curved surface 73, the second surface 74, and the surface 67 are positioned in the -R direction in this order. An angle formed between the surface 68 and the first surface 72 is almost a right angle when viewed in the right-left direction. An angle formed between the second surface 74 and the surface 67 is an obtuse angle. The shortest distance L1 between the center C1 of the pin 46 and the first surface 72 is smaller than the shortest distance L2 between the center C1 and the second surface 74. The distance L3 between the center C1 and the curved surface 73 continuously gets larger as being closer from a start point A1 of the curved surface 73 toward an end point A2 thereof in the -R direction. The second surface 74 extends upward and backward from the end point A2.
• A contact section 71 is formed such that the push piece 64 moves the clamp shaft 112 to the third position P3 (FIG. 14) when the clamp shaft 112 is positioned at the second position P2 (FIG. 15) while the operation force on the clamp lever 62 is released.
<<Drive Mechanism>>
• As illustrated in FIG. 4, a drive mechanism 80 includes a spindle 82, a ball bearing 84, an eccentric shaft 86, the swing arm 88, and the output shaft 90. The output shaft 90 includes the clamp shaft 112 and the clamp holder 126, and can swing the clamp shaft 112 around its axis.
<Spindle and Others>
• The spindle 82 is attached to the front of the rotary shaft 53 of the motor 52. The spindle 82 extends in the front-back direction and is rotated together with the rotary shaft 53. The ball bearing 84 is supported by the middle housing 35. The ball bearing 84 rotatably supports the center of the spindle 82 in the front-back direction. The eccentric shaft 86 is provided at the front end of the spindle 82. The central axis of the eccentric shaft 86 is parallel to the central axis of the spindle 82, and deviates from the central axis of the spindle 82.
<Swing Arm>
• The swing arm 88 includes an annular attachment 88A and a U-shaped arm 88B extending backward from the attachment 88A when viewed in the up-down direction. The attachment 88A is fixed to an outer peripheral surface of a unit casing 92 described later. The arm 88B sandwiches the outer periphery of the eccentric shaft 86. That is, the swing arm 88 makes cooperation between the rotation of the eccentric shaft 86 and the movement of the unit casing 92. Specifically, the arm 88B is swung in the right-left direction by the rotation of the eccentric shaft 86. Thereby, the output shaft 90 oscillates in the rotation direction around its axis.
<Output Shaft>
• FIG. 6 illustrates an internal structure of the front of the electric tool 10. Note that hatching is omitted in order to clearly illustrate the shapes of the respective components.
• The output shaft 90 configures a portion which holds the tip tool 16 and oscillates in the electric tool 10. The output shaft 90 includes the unit casing 92, the clamp shaft 112, the clamp holder 126, a support pin 132, a clamp spring 134, an O-ring 136, and the clamp member 142.
(Unit Casing)
• The unit casing 92 includes the container 94, an upper wall 96, the guide 98, a first larger-diameter section 102, and a second larger-diameter section 104. The unit casing 92 includes (or supports) a tool holding section 100.
• The container 94 is a cylindrical member with an axial direction as the up-down direction. The container 94 has an annular outer peripheral surface 94A and an annular inner peripheral surface 94B when viewed in the up-down direction. The swing arm 88 is fixed to the upper part of the container 94. The center of the container 94 in the up-down direction is in contact with an inner ring of the needle bearing 43. The lower part of the container 94 is in contact with the oil seal 44. The clamp holder 126 described later is housed in a portion inside the container 94, the portion being lower than a portion facing the oil seal 44.
• The upper wall 96 is a disk-shaped member, and covers the upper end of the container 94. The guide 98 extends upward from the upper wall 96. The guide 98 is a cylindrical member with a central axis along the up-down direction. The guide 98 is supported by the ball bearing 42 to be rotatable around the central axis along the up-down direction. A through-hole 99 is formed in the upper wall 96 and the guide 98. The through-hole 99 penetrates the upper wall 96 and the guide 98 in the up-down direction.
• The first larger-diameter section 102 extends downward from the lower end of the container 94. The first larger-diameter section 102 is a cylindrical member with the central axis along the up-down direction. The inner diameter of the first larger-diameter section 102 is larger than the inner diameter of the container 94. That is, the first larger-diameter section 102 is increased in its diameter relative to the container 94. Thereby, a step 103 is formed between the container 94 and the first larger-diameter section 102.
• The second larger-diameter section 104 extends downward from the lower end of the first larger-diameter section 102. The second larger-diameter section 104 is a cylindrical member with the central axis along the up-down direction. The inner diameter of the second larger-diameter section 104 is larger than the inner diameter of the first larger-diameter section 102. That is, the second larger-diameter section 104 is increased in its diameter relative to the first larger-diameter section 102. Thereby, a step 105 is formed between the first larger-diameter section 102 and the second larger-diameter section 104.
• As illustrated in FIG. 7, an attachment seat 107 (clamp base) is provided on an inner peripheral surface 104A of the second larger-diameter section 104. The attachment seat 107 engages with the tip tool 16 in a rotation direction with an axis as the up-down direction (an extending direction of a central axis C2 described later). In the attachment seat 107, a plurality of concave sections 107A and a plurality of convex sections 107B are alternately arranged along the circumferential direction of the inner peripheral surface 104A. An inclined surface 108 is formed at the lower end of the inner peripheral surface 104A. The attachment seat 107 can transmit power in the rotation direction around the clamp shaft 112 (FIG. 3) to the tip tool 16 when being in contact with the tip tool 16 (FIG. 2). The through-holes 106, which radially penetrate the center of the second larger-diameter section 104, are formed in the second larger-diameter section 104. The attachment seat 107 is part of the tool holding section 100. The attachment seat 107 holds the tip tool 16 when clamping the tip tool 16 (FIG. 4) in the clamping direction together with the clamps 158, 178 (FIG. 4) described later.
(Clamp Shaft)
• As illustrated in FIG. 6, the clamp shaft 112 moves between the first position P1 and the second position P2 (FIG. 15) in response to the movement of the clamp lever 62. Further, the clamp shaft 112 is an exemplary output shaft extending from the clamp holder 126 described later in the up-down direction. The clamp shaft 112 is a metallic member, and includes a first shaft 114, a second shaft 116, a flange 118, a support section 122, and a guide pin 124. The first shaft 114, the second shaft 116, the flange 118, and the support section 122 are unified.
• The first shaft 114 is shaped into a columnar shape with the central axis C2 along the up-down direction. The first shaft 114 passes through the through-hole 99 from the inside of the container 94, and protrudes upward from the upper end of the guide 98. The outer peripheral surface of the first shaft 114 is in contact with the inner peripheral surface of the through-hole 99. That is, the first shaft 114 is guided along the up-down direction by the guide 98. An upper end surface of the first shaft 114 is assumed as upper end surface 115. The upper end surface 115 is a surface along the front-back direction and the right-left direction. The upper end surface 115 is positioned to be in contact with the outer periphery 65.
• The second shaft 116 extends downward from the lower end of the first shaft 114. The second shaft 116 is shaped into a columnar shape. The outer diameter of the second shaft 116 is, for example, larger than the outer diameter of the first shaft 114.
• The flange 118 is a disk-shaped member which is a radially-outward overhang member from a boundary between the first shaft 114 and the second shaft 116. The flange 118 is positioned inside the container 94 and is lower than the upper wall 96.
• The support section 122 extends downward from the lower end of the second shaft 116. The support section 122 includes a facing wall 122A and a facing wall 122B. The facing wall 122A and the facing wall 122B face each other while being distant from each other in the right-left direction.
• The guide pin 124 is an exemplary pin member. The guide pin 124 is shaped into a columnar shape with the central axis along the right-left direction. The guide pin 124 couples the facing wall 122A and the facing wall 122B in the right-left direction. In other words, the support section 122 supports both ends of the guide pin 124 in the axial direction. As described above, the guide pin 124 is attached to the clamp shaft 112. The guide pin 124 is inserted into link holes 157 and 177 (FIG. 9) of movable sections 156 and 176 (FIG. 9) described later.
(Clamp Holder)
• As illustrated in FIG. 8, the clamp holder 126 includes a base 127, a plurality of longitudinal walls 128, a lateral wall 129, and the support pin 132. The clamp holder 126 is fixed to the lower part of the unit casing 92 (FIG. 6). The clamp holder 126A includes a space therein, which is large enough for permitting movement of the lower part of the support section 122 (FIG. 6) and the clamp member 142.
• The base 127 is shaped into a circular shape when viewed in the up-down direction. The base 127 is positioned inside the second larger-diameter section 104 (FIG. 6). A lower surface 127A along the front-back direction and the right-left direction is formed at the lower end of the base 127. An opening 127B penetrates the base 127 in the up-down direction. The opening 127B is shaped into a rectangular shape having long sides along the front-back direction and short sides along the right-left direction when viewed from the lower side. The opening 127B is large enough for permitting movement of the clamp member 124.
• The plurality of longitudinal walls 128 are upright from the base 127. The plurality of longitudinal walls 128 are positioned to be distant from each other in the circumferential direction and the radial direction. The plurality of longitudinal walls 128 are positioned inside the first larger-diameter section 102 (FIG. 6). A dent 131 dented in the radial direction is formed in the plurality of longitudinal walls 128. The lateral wall 129 couples the upper ends of the plurality of longitudinal walls 128.
(Support Pin)
• The support pin 132 is an exemplary support shaft extending in the right-left direction. The support pin 132 is shaped into a columnar shape. The support pin 132 passes through the center of the base 127, and penetrates the base 127 in the radial direction. The support pin 132 is fixed to the base 127 so as not to rotate. Both ends of the support pin 132 in the right-left direction are fixed to and supported by the second larger-diameter section 104 (FIG. 6).
(Clamp Spring)
• As illustrated in FIG. 6, the clamp spring 134 is provided between the second shaft 116 of the clamp shaft 112 and the inner peripheral surface 94B of the unit casing 92. The clamp spring 134 is expandable along the up-down direction. The upper end of the clamp spring 134 engages with the lower surface of the flange 118. The lower end of the clamp spring 134 is in contact with the lateral wall 129 (FIG. 8) of the clamp holder 126.
• The clamp spring 134 applies a pressing force to the clamp shaft 112 when pressing the flange 118 upward. Thereby, the upward pressing force acts on the guide pin 124. Additionally, since the pressing force of the clamp spring 134 acts on the first shaft 114, the first shaft 114 is held to protrude and be upper than the guide 98.
(O-ring)
• As illustrated in FIG. 8, the O-ring 136 is an exemplary biasing section and an exemplary annular elastic body. The O-ring 136 is an annular rubber member. The O-ring 136 straddles the plurality of longitudinal walls 128, and are fitted into the dent 131. Additionally, a portion of the O-ring 136 positioned in the circumferential direction, the portion being on the front and back sides, is assumed as a pressing section 137. The pressing section 137 is not in contact with the plurality of longitudinal walls 128. The pressing section 137 is elastically deformable at least in the front-back direction.
• The movable sections 156 and 176 (FIG. 9) of the clamp member 142 described later are positioned inside the O-ring 136. Further, when the clamp member 142 is positioned at the unload position, part of the O-ring 136 (the outer periphery of the pressing section 137) is in contact with the inner peripheral surface 94B (FIG. 6). This is because the O-ring 136 is deformed into an oval shape by the movable sections 156 and 176. Here, when the movable sections 156 and 176 are in contact with the pressing section 137, the elastically deformed O-ring 136 biases the movable sections 156 and 176 inward. That is, by a restoring force of the deformed O-ring 136, the movable sections 156 and 176 are biased inward, and the clamps 158 and 178 are biased outward. More specifically, the pressing section 137 biases the movable sections 156 and 176 radially inward (in the front-back direction) by using the restoring force of the O-ring 136 which has been deformed in the front-back direction (radial direction) by the movable sections 156 and 176 moved outward (in the front-back direction) and then has been consequently shaped into the oval shape. Thereby, the pressing section 137 causes the radially inward pressing force (restoring force) to act on the movable sections 156 and 176. As described above, the O-ring 136 is provided in the clamp holder 126 to bias the clamp member 142 radially inward when being in contact with the clamp member 142.
• As illustrated in FIG. 9, the O-ring 136 surrounds the movable sections 156 and 176 of both the first clamp member 144 and the second clamp member 164. The O-ring 136 is an exemplary biasing member for biasing the movable sections 156 and 176 such that the clamps 158 and 178 direct toward an open position described later. In other words, the O-ring 136 biases the clamps 158 and 178 positioned at the close position described later toward the open position (such that the clamps move toward the open position). Specifically, the O-ring 136 biases both the movable section 156 and the movable section 176 inward (toward its center) in the front-back direction. Additionally, the O-ring 136 is provided to continuously bias the clamps 158 and 178 positioned at the open position.
(Clamp Member)
• The clamp member 142 is rotatable around the support pin 132. The clamp member 142 includes the first clamp member 144 and the second clamp member 164 which are rotatable around the support pin 132 in opposite directions to each other. Part of the first clamp member 144 is closer to the right side than part of the second clamp member 164. In the following explanation about the positions of the respective portions of the first clamp member 144 and the second clamp member 164, it is assumed that the clamps 158 and 178 described later are positioned at the close position to be in contact with each other.
• The clamp 142 includes the paired clamp members 158 and 178. The movable sections 156 and 176, which are biased by the O-ring 136, are provided at the other side (upper side) in the clamping direction relative to the support pin 132 of the clamp 142.
• The movable section 156 and the clamp 158 are provided such that either one of them moves to one side (front side) in the front-back direction, thereby moving the other to the other side (back side) in the front-back direction. The movable section 176 and the clamp 178 are provided such that either one of them moves to the front side, thereby moving the other to the back side. The first clamp member 144 and the second clamp member 164 will be specifically described later. The clamp members (particularly clamp) are part of the tool holding section 100.
(First Clamp Member)
• As illustrated in FIG. 10, the first clamp member 144 includes an insertion section 146, an overhang 148, a leg 152, a protrusion 154, the movable section 156, and the clamp 158.
((Insertion Section))
• The insertion section 146 configures the center of the first clamp member 144 in the up-down direction. An annular insertion hole 146A, which penetrates in the right-left direction, is formed in the insertion section 146. The support pin 132 (FIG. 9) is inserted into the insertion hole 146A. A contact surface 147 is formed at the left end of the insertion section 146 and at the left end of the movable section 156. The contact surface 147 is shaped into a planar shape along the up-down direction and the front-back direction.
((Overhang))
• The overhang 148 overhangs leftward from the contact surface 147. An upper surface 148A is formed at the upper end of the overhang 148. A curved surface 149 is formed at the front end of the insertion section 146 and at the front end of the overhang 148. The curved surface 149 is shaped into an arc shape when viewed in the right-left direction.
((Leg))
• The leg 152 extends downward from the lower end of the insertion section 146 and the lower end of the overhang 148. A facing surface 153 is formed at the back end of the leg 152 and at the back end of the clamp 158. The facing surface 153 is shaped into a planar shape along the up-down direction and the right-left direction.
((Protrusion))
• The protrusion 154 protrudes leftward from the front end of the contact surface 147. The protrusion 154 is shaped into a prismatic shape extending in the right-left direction. Additionally, when being in contact with the movable section 176, the protrusion 154 limits the second clamp member 164 (FIG. 11) from rotating forward.
((Movable Section))
• The movable section 156 is provided at the other side (upper side) in the clamping direction relative to the support pin 132 of the first clamp member 144. The movable section 156 is biased by the O-ring 136 (FIG. 9). The movable section 156 extends forward and upward (obliquely upward) from the upper end of the insertion section 146. The link hole 157, which penetrates in the right-left direction, is formed (provided) in the movable section 156. The link hole 157 is an exemplary link section extending in a direction crossing with the clamping direction.
• The link hole 157 includes a long hole section 157A at the front side (upper side) and a larger-width section 157B at the back side (lower side). The long hole section 157A and the larger-width section 157B are formed to be unified, and are continuously formed as a hole. When viewed in the right-left direction, the long hole section 157A is a section having almost the constant hole widths at the respective positions as being closer to the oblique up side. Further, the width of the long hole section 157A is slightly larger than the diameter of the guide pin 124. Thus, when the guide pin 124 is positioned in the long hole section 157A, the movement of the movable section 156 is limited by the guide pin 124. The larger-width section 157B is a trapezoidal section whose hole width is gradually larger as being closer to the oblique down side. While the lower surface of the larger-width section 157B tilts in continuity with the lower surface of the long hole section 157A to be at the same angle as that of the lower surface of the long hole section 157A, the upper surface of the larger-width section 157B tilts at a different angle from that of the upper surface of the long hole section 157A. Specifically, the up-down direction tile angle of the upper surface of the larger-width section 157B is configured to be more obtuse (have an obtuse angle) than that of the upper surface of the long hole section 157A. By the configuration, the width of the larger-width section 157B is made larger than that of the long hole section 157A. Thus, the width of the larger-width section 157B is made larger than the diameter of the guide pin 124. A space is formed between the larger-width section 157B and the guide pin 124. When the guide pin 124 is positioned in the larger-width section 157B, the limitation of the movement of the movable section 156 by the guide pin 124 is weaker than that when the guide pin 124 is positioned in the long hole section 157A. The space between the larger-width section 157B and the guide pin 124 is made larger than 1/5 of the radius of the guide pin 124.
((Clamp))
• The clamp 158 extends downward and forward from the lower end of the leg 152. The clamp 158 is provided at one side (the lower side) in the clamping direction relative to the support pin 132 of the first clamp member 144. The clamp 158 is shaped into a substantially semicircular shape when viewed from below. The clamp 158 protrudes forward from the lower end of the leg 152 while the insertion section 146 protrudes forward from the upper end of the leg 152, thereby forming a U-shaped groove 161. The clamp 158 has, for example, a bottom surface 158A, a tapered surface 158B, a side surface 158C, a holding surface 158D, and the facing surface 153.
• The bottom surface 158A is shaped into a planar shape along the front-back direction and the right-left direction. The tapered surface 158B is an exemplary tapered section, and extends obliquely upward from the outer periphery of the bottom surface 158A. That is, the tapered surface 158B is along an oblique direction crossing with the clamping direction.
• The side surface 158C extends upward from the upper end of the tapered surface 158B. The holding surface 158D extends from the upper end of the side surface 158C toward the outer peripheral surface of the leg 152. The holding surface 158D extends obliquely downward such that the front end thereof is positioned lower than the back end thereof. Additionally, the holding surface 158D is shaped into a planar shape. Thus, when the holding surface 158D is arranged along the front-back direction and the right-left direction (horizontal direction), the holding surface 158D can hold the tip tool 16 (FIG. 1) from below. Additionally, a thickness of the tip tool or the like varies depending on its type, and thus, the holding surface 158D is not necessarily horizontal when holding the tip tool.
(Second Clamp Member)
• As illustrated in FIG. 11, the second clamp member 164 includes an insertion section 166, an overhang 168, a leg 172, a protrusion 174, the movable section 176, and the clamp 178. Additionally, the second clamp member 164 has, for example, the same shape and the same size as those of the first clamp member 144 (FIG. 10). In other words, the second clamp member 164 is equivalent to a member resulted from rotation of the first clamp member 144 by 180 degrees around its axis along the up-down direction. Note that the first clamp member 144 and the second clamp member 164 are different in their arrangements relative to the support pin 132 (FIG. 9) in the front-back direction, and are discriminated from each other by use of the different reference numerals.
((Insertion Section))
• The insertion section 166 configures the center of the second clamp member 164 in the up-down direction. An annular insertion hole 166A, which penetrates in the right-left direction, is formed in the insertion section 166. The support pin 132 (FIG. 9) is inserted into the insertion hole 166A. A contact surface 167 is formed at the right end of the insertion section 166 and at the right end of the movable section 176. The contact surface 167 is shaped into a planar shape along the up-down direction and the front-back direction. The contact surface 167 is in contact with the contact surface 147 (FIG. 10) in the right-left direction.
((Overhang))
• The overhang 168 overhangs rightward from the contact surface 167. An upper surface 168A is formed at the upper end of the overhang 168. A curved surface 169 is formed at the front end of the insertion section 166 and at the front end of the overhang 168. The curved surface 169 is shaped into an arc shape when viewed in the right-left direction.
((Leg))
• The leg 172 extends downward from the lower end of the insertion section 166 and the lower end of the overhang 168. A facing surface 173 is formed at the back end of the leg 172 and at the back end of the clamp 178. The facing surface 173 is shaped into a planar shape along the up-down direction and the right-left direction. The facing surface 173 is configured to face or be in contact with the facing surface 153 (FIG. 10) in the front-back direction.
((Protrusion))
• The protrusion 174 protrudes rightward from the back end of the contact surface 167. The protrusion 174 is shaped into a prismatic shape extending in the right-left direction. Additionally, when being in contact with the movable section 156, the protrusion 174 limits the backward rotation of the first clamp member 144 (FIG. 10).
((Movable Section))
• The movable section 176 is provided at the other side (upper side) in the clamping direction relative to the support pin 132 of the second clamp member 164. The movable section 176 is biased by the O-ring 136 (FIG. 9). The movable section 176 extends backward and upward (obliquely upward) from the upper end of the insertion section 166. The link hole 177, which penetrates in the right-left direction, is formed (provided) in the movable section 176. The link hole 177 is an exemplary link section extending in a direction crossing with the clamping direction.
• A long hole section 177A at the back side and a larger-width section 177B at the front side are formed to be unified in the link hole 177. When viewed in the right-left direction, the long hole section 177A is a section having almost the constant hole widths at the respective positions as being closer to the oblique up side. The larger-width section 177B is a trapezoidal section whose hole width is gradually larger as being closer to the oblique down side. Additionally, a relationship between the diameter of the guide pin 124 and the widths of the long hole section 177A and the larger-width section 177B is similar to that in the first clamp member 144. That is, when the guide pin 124 is positioned in the larger-width section 177B, the limitation of the movement of the movable section 176 by the guide pin 124 is weaker than that when the guide pin 124 is positioned in the long hole section 177A.
((Clamp))
• The clamp 178 extends downward and backward from the lower end of the leg 172. The clamp 178 is provided at one side (lower side) in the clamping direction relative to the support pin 132 of the second clamp member 164. The clamp 178 is shaped into a substantially semicircular shape when viewed from below. The clamp 178 protrudes backward from the lower end of the leg 172 while the insertion section 166 protrudes backward from the upper end of the leg 172, thereby forming a U-shaped groove 181. The clamp 178 has, for example, a bottom surface 178A, a tapered surface 178B, a side surface 178C, a holding surface 178D, and the facing surface 173.
• The bottom surface 178A is shaped into a planar shape along the front-back direction and the right-left direction. The tapered surface 178B is an exemplary tapered section, and extends obliquely upward from the outer periphery of the bottom surface 178A. That is, the tapered surface 178B is along an oblique direction crossing with the clamping direction.
• The side surface 178C extends upward from the upper end of the tapered surface 178B. The holding surface 178D extends from the upper end of the side surface 178C toward the outer peripheral surface of the leg 172. The holding surface 178D extends obliquely downward such that the back end thereof is positioned lower than the front end thereof. Additionally, the holding surface 178D is shaped into a planar shape. Thus, when the holding surface 178D is arranged along the horizontal direction, the holding surface 178D can hold the tip tool 16 from below. Additionally, the holding surface 178D is not necessarily horizontal as similar to the holding surface 158D.
• As illustrated in FIG. 9, the clamps 158 and 178 are provided in the clamp holder 126 (the tool holding section 100) to be rotatable (openable/closable) toward the different sides from each other in the front-back direction in response to the up-down movement of the clamp shaft 112. The clamps 158 and 178 are rotatably supported by the support pin 132, and are switched between the open position and the close position in the front-back direction in response to their rotation. Note that the open position and the close position will be described later. As described above, the clamps 158 and 178 are provided in the clamp holder 126 to be movable in the front-back direction in response to the rotation of the first clamp member 144 and the second clamp member 164.
<Position of Clamp Shaft and Position of Clamp>
• As illustrated in FIG. 12, a state in which the clamps 158 and 178 bias the tip tool 16 toward the clamp holder 126 and the unit casing 92 while the tip tool 16 is fixed is called a clamping state (fixing state) of the clamp members 158 and 178 (the clamp 142). Further, a position of the clamp shaft 112 (the upper end surface 115) in the up-down direction when the tip tool 16 is fixed is assumed as first position P1. In the following explanation, the position of the clamp shaft 112 in the up-down direction is indicated by the position of the upper end surface 115. Additionally, if the position of the clamp shaft 112 that is the member moving in the up-down direction is the same between the state of holding the tip tool 16 and the state of not holding the tip tool 16, the clamping force may not be appropriately applied to the tip tool 16, and thus, the first position P1 may not be the uppermost position of the clamp shaft 112. Specifically, the first position P1 may be slightly lower than the uppermost position of the clamp shaft 112. Further, in this case, upward movement of the clamp shaft 112 at the uppermost position may be limited by the push piece 64 or may be limited inside the unit casing 92.
• When the clamp shaft 112 is positioned at the first position P1, (at least some parts of) the clamps 158 and 178 overlap the tip tool 16 in the clamping direction (the up-down direction parallel to the clamping direction) and are brought into the clamping state (fixing state) (are at the fixing position) to bias the tip tool 16 in the clamping direction (upward). In the clamping state, the tip tool 16 is clamped in the up-down direction.
• As illustrated in FIG. 15, a state in which the biasing of the clamps 158 and 178 to the tip tool 16 is released is called a clamping release state of the clamp members 158 and 178 (the clamp 142). At this time, the clamp members 158 and 178 (the clamp 142) are at the release position. Further, a position of the clamp shaft 112 (the upper end surface 115) in the up-down direction in the clamping release state is assumed as second position P2. Additionally, in the clamping release state, the entire facing surface 153 and the entire facing surface 173 have surface contact with each other in the front-back direction. As described above, by the movement of the clamp shaft 112 from the first position P1 to the second position P2, the clamps 158 and 178 are moved in the direction (front-back direction) crossing with the clamping direction, and are brought into the clamping release state (at the release position) to release the holding of the tip tool 16. Additionally, when the clamp shaft 112 is positioned at the second position P2, the rotations of the first clamp member 144 and the second clamp member 164 are limited by the contact between the facing surface 153 and the facing surface 173 and the contact between the guide pin 124 and the lower surfaces of the link holes (157 and 177), and thus, the clamps 158 and 178 are held at the release position. As described above, when the clamp shaft 112 is positioned at the second position P2, the clamps 158 and 178 are brought into the release state to release the holding of the tip tool 16 when moving in the front-back direction.
• As illustrated in FIG. 14, FIG. 16, and FIG. 17, a state in which the clamps 158 and 178 are movable in the front-back direction is called a temporarily holding state of the clamps 158 and 178. Even if the operation force is released in the temporarily holding state, the clamp lever 62 is held at a predetermined position. In the temporarily holding state in the present embodiment, the clamps 158 and 178 have a degree of freedom of the front-back direction movement, and can bias the tip tool 16 and unload the biasing. That is, in the temporarily holding state, the clamps 158 and 178 can be brought into the state of biasing the tip tool 16 and the state of not biasing it. Further, a position of the upper end surface 115 in the up-down direction in the temporarily holding state is assumed as a third position P3. The third position P3 is between the first position P1 and the second position P2 in the up-down direction. In other words, when the clamp lever 62 holds the clamp shaft 112 at the third position P3, the clamps 158 and 178 are brought into the temporarily holding state to bias the tip tool 16 or unload the biasing. Additionally, in the temporarily holding state, the biasing force on the tip tool 16 is weaker than that in the fixing state since the upward biasing force of the clamp spring 134 is received by the push piece 64. Specifically, in the temporarily holding state, the biasing force on the tip tool 16 by the clamp spring 134 is zero. Further, in the temporarily holding state, a (up-down) biasing force is received as a reaction force from the O-ring 136 when the tip tool 16 is pressed to rotate the first clamp member 144 and the second clamp member 164.
• In the temporarily holding state, positions of the clamps 158 and 178 permitting the tip tool 16 to be attached or detached are assumed as close position. The close position includes the release position. Further, positions of the clamps 158 and 178 for holding the tip tool 16 are assumed as open position. When the clamps 158 and 178 are at the open position, the tip tool 16 is (temporarily) held by the clamps 158 and 178 so as not to be dropped by its weight. The positions of the clamps 158 and 178 illustrated in FIG. 14, FIG. 16, and FIG. 17 are positions of the open position where the clamp 158 is the most distant from the clamp 178.
• When the clamp lever 62 holds the clamp shaft 112 at the third position P3, the clamps 158 and 178 are movable between the close position and the open position. Additionally, the degree of freedom of the clamps 158 and 178 when the clamp shaft 112 is held at the third position P3 means a movable range between the close position and the open position. That is, the presence of the degree of freedom means the presence of the movable range.
• As illustrated in FIG. 14, when the clamps 158 and 178 are at the open position, some parts of the clamps 158 and 178 are aligned with (face) the tip tool 16 in the clamping direction. In other words, when viewed in the up-down direction, the clamps 158 and 178 overlap the tip tool 16. By this positional relationship, the clamps 158 and 178 support and temporarily hold the tip tool 16 from below.
• As illustrated in FIG. 15, when the clamps 158 and 178 are positioned at the close position, the clamps 158 and 178 are not aligned with the tip tool 16 in the clamping direction. In other words, when viewed in the up-down direction, the clamps 158 and 178 do not overlap the tip tool 16. That is, the tip tool 16 is detachable from the clamps 158 and 178 (is detached by its weight).
• As illustrated in FIG. 14 and FIG. 16, when the clamp shaft 112 is positioned at the third position P3 while the clamps 158 and 178 are positioned at the open position, the guide pin 124 is in contact with the lower surfaces of the link holes 157 and 177. Thereby, further opening movement (movement toward the fixed position) of the clamps 158 and 178 in the states of FIG. 14 and FIG. 16 from the open position is limited by the contact between the guide pin 124 and the link holes 157, 177.
• As illustrated in FIG. 17, in the temporarily holding state, the clamps 158 and 178 are moved from the open position to the close position by the transmission of the force from the tip tool 16 to the clamps 158 and 178, thereby attaching or detaching the tip tool 16 in the tool holding section 100. Specifically, the clamps 158 and 178 move toward the close position when the force in the clamping direction is applied to the tapered surfaces 158B and 178B. That is, in the temporarily holding state, the clamps 158 and 178 at the open position can be moved to the close position by pressing the tip tool 16 against the clamps 158 and 178 from below.
• FIG. 18 illustrates a case where the clamp shaft 112 is at the third position P3 (FIG. 14) while the clamps 158 and 179 are at the open position. In this case, the clamps 158 and 178 temporarily hold the tip tool 16 such that the tip tool 16 can be distant from the attachment seat 107 (in the clamping direction). That is, the clamps 158 and 178 are in the temporarily holding state. Further, in this case, the opening movement of the clamps 158 and 178 is limited by the contact between the guide pin 124 and the link holes 157, 177.
• Additionally, a state in which the clamps 158 and 178 are in the clamping state means a state in which the clamps 158 and 178 are at the fixing position to fix the tip tool 16 to the clamp shaft 112. A state in which the clamps 158 and 178 are in the release state means a state in which the clamps 158 and 178 are at the release position.
• A state in which the clamps 158 and 178 are in the temporarily holding state means a state in which the clamps 158 and 178 are at the temporarily holding position which is the inward position of the fixing position in the front-back direction and at which the position of the tip tool 16 can change to a position around the clamp shaft 112.
• The temporarily holding position includes the close position and the open position. As described above, the clamps 158 and 178 can rotate and move to the fixing position, the close position, and the temporarily holding position.
• The tool holding section 100 includes the support pin 132 extending in the axial direction crossing with both the clamping direction and a direction crossing with the clamping direction, and the clamp 142 rotatable around the support pin 132. The tool holding section 100 can hold the tip tool 16 when applying the clamping force in the clamping direction to the tip tool 16.
• The tool holding section 100 may be brought into either the fixing state or the temporarily holding state. The fixing state of the tool holding section 100 is a state in which the clamps 158 and 178 at the fixing position apply the biasing force in the clamping direction to the tip tool 16, thereby fixing the tip tool 16 to the tool holding section 100. The temporarily holding state of the tool holding section 100 is a state in which the clamps 158 and 178 are at a position different from the fixing position, thereby causing the weaker biasing force in the clamping direction on the tip tool 16 than that of the state in which the clamps 158 and 178 are positioned at the fixing position.
• When the tool holding section 100 is in the temporarily holding state, the positions of the clamps 158 and 178 can change between the open position and the close position, and the clamps 158 and 178 can move to the close position in response to the force from the tip tool 16 when being at the open position. The open position of the clamps 158 and 178 is a position at which the tip tool 16 can be held by the tool holding section 100. The close position of the clamps 158 and 178 is a position at which the tip tool 16 can be attached to or detached from the tool holding section 100.
• FIG. 19 illustrates schematic positions of the clamps 158 and 178 relative to the hole 24 of the tip tool 16 in the clamping direction. Four types of positions are illustrated. The positions of the clamps 158 and 178 in the state (release state) in which the clamps 158 and 178 are closest to each other in the front-back direction are illustrated with solid lines. Further, the positions of the clamps 158 and 178 at the open position in the temporarily holding state are illustrated with dashed-dotted lines. Further, the positions of the clamps 158 and 178 in the fixing state are illustrated with dotted lines. Additionally, a position illustrated with broken lines is a position at which the clamps 158 and 178 at the open position in the temporarily holding state move inward such that the outer edges of the clamps 158 and 178 are at almost the same positions as that of the inner surface of the insertion section 25 (slightly inward from the inner surface of the insertion section 25) to permit the clamps 158 and 178 to barely pass through the insertion section 25. Note that the clamps 158 and 178 in FIG. 19 are illustrated as only the positions of the lower surfaces 158A, 178A and the tapered surfaces 158B, 178B. In FIG. 19, the front end position of the clamp 158 is the same as the front end position of the holding surface 158D. Similarly, the back end position of the clamp 178 is the same as the back end position of the holding surface 178D. Additionally, the respective lines indicating the positions of the clamps 158 and 178 are schematic, and do not exactly indicate the outer shapes.
• Although not illustrated in FIGs. 12 to 18, when the tip tool 16 is pressed against the clamps 158 and 178 from below in the temporarily holding state, the clamps 158 and 178 are basically configured not to move to the release position. That is, when the tip tool 16 is pressed against the tapered surfaces 158B and 178B of the clamps 158 and 178 positioned as illustrated with the dashed-dotted lines (in the temporarily holding state at the open position) in FIG. 19, the clamps 158 and 178 move inward, but do not move to the positions illustrated with the solid lines and move to the positions illustrated with the broken lines. This is because the clamps 158 and 178 at the positions illustrated with the broken lines do not overlap the tip tool 16 in the clamping direction at the time of the pressing of the tip tool 16 against the clamps 158 and 178 from below such that the clamps 158 and 178 pass through the hole 24 at this time. The positions illustrated with the broken lines are one of the close positions in the present invention. The fact that the clamps 158 and 178 can pass through the hole 24 at the positions illustrated with the broken lines is clear from, for example, the fact that the inner diameter of the hole 24 is larger than the outer diameters of the clamps 158 and 178 at the release position as illustrated in FIG. 17. Additionally, in the present embodiment, the clamps 158 and 178 can move to the release position even in the temporarily holding state. This is because of the widths of the larger-width sections 157B and 177B. Conversely, the movable range of the clamps 158 and 178 can be adjusted even in the temporarily holding state by adjusting the sizes of the larger-width sections 157B and 177B. For example, when the angles of the upper surfaces of the larger-width sections 157B and 177B are brought to those of the long hole sections 157A and 177A, the clamps 158 and 178 in the temporarily holding state may be prevented from moving to the release position.
[Function of First Embodiment]
• The operation of attaching and detaching the tip tool 16 in the electric tool 10 will be described with reference to FIGs. 12 to 18. Note that FIGs. 12 to 18 briefly illustrate the components for the operation of attaching and detaching the tip tool 16 in the drive mechanism 80 viewed from the right side in the right-left direction. The description for the components other than the drive mechanism 80 is made with reference to FIGs. 1 to 11, and the respective drawing numbers are omitted.
• As illustrated in FIG. 12, when the clamp lever 62 is positioned along the front-back direction, the first surface 72 is positioned along the front-back direction while the clamps 158 and 178 are in the clamping state. In FIG. 12, the clamp lever 62 (and the push piece 64) is positioned at the initial position. Note that a line "K", which passes through the center of the pin 46 and extends along the first surface 72, is illustrated with a dashed-dotted line. The line K indicates a posture of the clamp lever 62 relative to the horizontal surface. In the clamping state, the upper end surface 115 is positioned at the first position P1 in the up-down direction. Further, the line K is positioned at an angle "θA" from the front-back direction (horizontal surface). The "angle θA = 0°" is set.
• In the clamping state, the tip tool 16 is fixed. Thus, when the motor 52 is driven in the clamping state, the swing arm 88 is swung, and the clamp shaft 112 is swung, thereby oscillating the tip tool 16.
• Further, in the clamping state, the first surface 72 and the upper end surface 115 face each other while being distant from each other by a gap "d" in the up-down direction. That is, the push piece 64 is distant from the clamp shaft 112. The movable sections 156 and 176 are pulled up by the guide pin 124, and come close to each other in the front-back direction. In other words, at least some parts of the movable sections 156 and 176 when viewed in the right-left direction overlap each other in the front-back direction. At this time, the movable sections 156 and 176 are distant from the O-ring 136. The facing surface 173 is at a (back side) position having an angle "θ1" from a reference surface "M" which passes through the center of the support pin 132 and extends along the up-down direction. The facing surface 153 is at a (front side) position symmetric to the position of the facing surface 173 in the front-back direction.
• As illustrated in FIG. 13, when the clamp lever 62 starts being rotated forward, the back end of the curved surface 73 starts being in contact with the upper end surface 115. The clamp shaft 112 moves to a position PA lower than the first position P1 in response to action of a pressing force from the curved surface 73. Note that a gap between the first position P1 and the position PA in the up-down direction is "d2". The clamp shaft 112 and the guide pin 124 move downward, and the guide pin 124 is in contact with the lower surfaces of the link holes 157 and 177, and thus, the movable sections 156 and 176 receive a downward pressing force from the guide pin 124. Thereby, the movable sections 156 and 176 start rotating to be distant from each other in the front-back direction. More specifically, the first clamp member 144 and the second clamp member 164 rotate around the support pin 132 such that the movable sections 156 and 176 are distant from each other in the front-back direction. At this time, the line K is at a position having an angle "θB" (> θA) from the horizontal surface. The facing surface 173 is at a position having an angle "θ2" (< θ1) from the reference surface M. Note that a movement amount (rotation amount) of the movable sections 156 and 176 with respect to a descent amount of the guide pin 124 depends on the tilt angles of the lower surfaces of the link holes 157 and 177.
• As illustrated in FIG. 14, when the clamp lever 62 rotates further forward, the second surface 74 is in contact with the upper end surface 115. The clamp shaft 112 moves to the third position P3 lower than the position PA (FIG. 13) in response to action of a pressing force from the second surface 74. Note that a gap between the first position P1 and the third position P3 in the up-down direction is "d3" (> d2).
• When the movable sections 156 and 176 (the lower surfaces of the link holes 157 and 177) receive the pressing force from the guide pin 124, the movable sections 156 and 176 further move from the state of FIG. 13 to be distant from each other in the front-back direction. Thereby, the movable sections 156 and 176 are in contact with the O-ring 136. Note that this state is the temporarily holding state in which the tips of the clamps 158 and 178 can be in contact with or distant from the periphery of the hole 24 in the up-down direction. If an action direction of the force of gravity is the down side, the tips of the clamps 158 and 178 are brought into contact with the periphery of the hole 24 in the up-down direction by the weight of the tip tool 16. At this time, the line K is at a position having an angle "θC" (> θB) from the horizontal surface. The facing surface 173 is at a position having an angle "θ3" (< θ2) from the reference surface M.
• In the temporarily holding state, the guide pin 124 is positioned in the larger-width sections 157B and 177B, and the limitation on the movement (rotation) of the first clamp member 144 and the second clamp member 164 by the guide pin 124 is weaken. Thus, in the temporarily holding state, the clamps 158 and 178 have a degree of freedom in the rotation direction (open/close direction). That is, when being biased by the O-ring 136, the clamps 158 and 178 are movable in a range between the position (included in the open position) at which the guide pin 124 abuts on the lower surfaces of the link holes 157 and 177 and the position (included in the close position) at which the guide pin 124 abuts on the upper surfaces of the link holes 157 and 177. Therefore, the clamps 158 and 178 move to the close position when being pressed by the periphery of the hole 24, or move to the open position when not being pressed by the periphery of the hole 24. Thereby, in the temporarily holding state, the tip tool 16 can be attached to or detached from (or temporarily held by) the clamps 158 and 178.
• As illustrated in FIG. 15, when the clamp lever 62 rotates further forward, the front of the second surface 74 is in contact with the front of the upper end surface 115. Thereby, the clamp shaft 112 moves to the second position P2 lower than the third position P3 (FIG. 14) in response to action of a pressing force from the second surface 74. Note that a gap between the first position P1 and the second position P2 in the up-down direction is "d4" (> d3).
• When receiving a pressing force from the guide pin 124, the movable sections 156 and 176 further rotate to be distant from each other in the front-back direction. At this time, the line K is at a position having an angle "θD" (> θC) from the horizontal surface. The facing surface 173 is at a position having an angle "θ4 = 0°" from the reference surface M. In other words, the entire facing surface 173 is in contact with the entire facing surface 153 in the front-back direction. The contact between the entire facing surface 153 and the entire facing surface 173 causes the release state. In the release state, the clamps 158 and 178 are at the release position, and the tip tool 16 is detached from the clamps 158 and 178. In the release state, there is no support for the tip tool 16 from below, and thus, the tip tool 16 is detached from the tool holding section 100 (the clamps) by its weight. Thus, the tip tool 16 can be detached from the tool holding section 100 by only the operation for the clamp lever 62.
• Here, a pressing force acts from the clamp spring 134 onto the clamp shaft 112, and thus, a force "F" acts obliquely upward from the upper end surface 115 onto the push piece 64. The force F acts as a rotation force in the -R direction (FIG. 5) for rotating the clamp lever 62 backward. Thereby, the clamp lever 62 rotates to return backward.
• As illustrated in FIG. 16, by the backward rotation of the clamp lever 62, a surface contact state between the second surface 74 and the upper end surface 115 is caused. In this state, the center of the pin 46 is positioned in a direction of action of a force from the upper end surface 115 onto the second surface 74, and thus, the clamp lever 62 is difficult to rotate backward. That is, the temporarily holding state is kept as similar to the state of FIG. 14.
• As illustrated in FIG. 17, in the temporarily holding state, the tip tool 16 can be attached to and detached from (and temporarily held by) the clamps 158 and 178. When the clamp lever 62 rotates backward while the tip tool 16 is temporarily held, the temporarily-held tip tool 16 is brought into the fixing state (FIG. 12).
• As illustrated in FIG. 18, in the temporarily holding state, a space "h" is caused between the inclined surface 108 and the outer periphery 21A in the up-down direction. As described above, a non-contact state between the outer periphery 21A and the attachment seat 107 (a state without engagement in the rotation direction) can be caused, and thus, the position of the tip tool 16 can be freely changed in the swinging direction (in the direction illustrated with an arrow RW in FIG. 11) around the clamp shaft 112. Additionally, the tip tool 16 is adjusted in its position in the swinging direction, and then, the clamps 158 and 178 are brought into the clamping state, thereby fixing the tip tool 16. As described above, the fixing state and the release state of the clamps can be switched by only the operation for the clamp lever 62.
• Further, as supplementarily illustrated in FIG. 19, the clamps 158 and 178 in the temporarily holding state can pass through the hole 24 of the tip tool 16 without moving to the release position. Thereby, a failure due to manufacturing error can be suppressed. Further, a plurality of types of tip tools with differently-sized holes 24 can be attached (temporarily held). In the present embodiment, at least three types of tip tools with different-diameter holes 24 (insertion sections 25) can be attached (temporarily held).
• As described above, when the clamp lever 62 holds the clamp shaft 112 at the third position P3 in the electric tool 10, the clamps 158 and 178 are brought into the temporarily holding state to have a degree of movable freedom in the front-back direction. Thereby, when the clamps 158 and 178 are pressed against the tip tool 16 from above, even if the pressing force is weak, the clamps 158 and 178 move from the open position to the close position, and then, move from the close position to the open position, thereby temporarily holding the tip tool 16. Further, since the clamps 158 and 178 have the degree of freedom, the tip tool 16 in the temporarily holding state can be detached from the clamps 158 and 178 without action of a strong pulling force. As described above, the tip tool 16 in the electric tool 10 can be easily attached and detached, thereby improving the workability.
• In the electric tool 10, the tip tool 16 can be attached by less operations, thereby improving the workability. For example, if the tip tool 16 needs to be replaced after the working, the clamping release state is caused by the rotation of the clamp lever 62, and the tip tool can be detached. Further, the temporarily holding state is caused by placing the tip tool 16 to be replaced, on a working table and then making contact of the tip tool 16 with the clamps 158 and 178, and thus, the tip tool 16 can be attached by the rotation of the clamp lever 62. As described above, the tip tool 16 can be attached and detached by the two operations of pulling up and pushing down the clamp lever 62, and thus, the workability can be improved.
• In the electric tool 10, the clamps 158 and 178 have the degree of freedom, and thus, do not overlap the tip tool 16 in the clamping direction at the close position, and thus, the tip tool 16 can be easily attached.
• In the electric tool 10, the tip tool 16 is in contact with the clamps 158 and 178, thereby moving the clamps 158 and 178 to the close position. As described above, the clamps 158 and 178 can be moved by the force from the tip tool 16, thereby improving the workability.
• In the electric tool 10, the movable sections 156 and 176 are biased by the O-ring 136 to come close to each other in the front-back direction, thereby moving the clamps 158 and 178 to the open position. That is, the clamps 158 and 178 brought into the closed state by the contact with the tip tool 16 can be returned to the open state without any special operation, and thus, the temporarily holding operation for the tip tool 16 can be easily achieved.
• In the electric tool 10, even when the clamps 158 and 178 are positioned at the open position, the biasing force is continuously acted on the movable sections 156 and 176 by the O-ring 136. Thereby, when the clamp lever 62 is operated in order to fix the tip tool 16, the clamps 158 and 178 can be smoothly moved from the open position to the position for the clamping state.
• In the electric tool 10, by the rotation of the clamps 158 and 178 around the support pin 132, the open position and the close position are switched to each other. Thus, the space required for the movement of the clamps 158 and 178 in the front-back direction can be made smaller than that in a configuration in which the clamps 158 and 178 slide in the front-back direction.
• In the electric tool 10, the clamps 158 and 178 are lower than the support pin 132, and the movable sections 156 and 176 are upper than the support pin 132. Additionally, the O-ring 136 biases the movable sections 156 and 176. Thereby, the O-ring 136 does not need to directly bias the clamps 158 and 178, thereby preventing the O-ring 136 from hindering the movement of the clamps 158 and 178 for holding the tip tool 16.
• In the electric tool 10, the O-ring 136 is arranged inside the unit casing 92, and thus, deterioration of the O-ring 136 due to contact with other member or water adhesion can be prevented.
• In the electric tool 10, the O-ring 136 biases both the movable sections 156 and 176. Thereby, for example, the first clamp member 144 is fixed in its position, and the rotation of only the second clamp member 164 is not caused, and thus, deterioration such as abrasion due to rotation of only one of the first clamp member 144 and the second clamp member 164 can be suppressed. Further, the first clamp member 144 and the second clamp member 164 can be suitably held at the open position. Further, one O-ring 136 can bias the movable sections 156 and 176, and thus, a plurality of biasing members are not to be provided.
• In the electric tool 10, the outer diameters of the portion with the tapered surfaces 158B and 178B in the clamps 158 and 178 continuously gets smaller as getting closer to the down side. Thereby, by the action of the upward biasing force from the tip tool 16 onto the tapered surfaces 158B and 178B, the clamps 158 and 178 are easily moved inward because of its component force, and as a result, the clamps 158 and 178 easily pass through the hole 24 of the tip tool 16. Further, the holding surfaces 158D and 178D in the temporarily holding state similarly tilt from the clamping direction (the up-down direction), and have the outer diameters getting larger as getting closer to the down side. Thereby, when the tip tool 16 in the temporarily holding state is biased downward, the clamps 158 and 178 are suitably moved inward by the tilt function of the holding surfaces 158D and 178D, thereby easily detaching the tip tool 16.
• In the electric tool 10, the clamps 158 and 178 hold the tip tool 16 such that the tip tool 16 can be distant from the attachment seat 107. Specifically, while the clamp 142 is kept at the open position (without moving the clamps 158 and 178), the tip tool 16 can be distant from the unit casing 92 and the clamp holder 126. Thereby, the operator can change the orientation of the tip tool 16 while the clamp 142 keeps holding the tip tool 16. That is, the tip tool 16 does not need to be detached every time the orientation of the tip tool 16 changes, and excellent workability is achieved.
• In the electric tool 10, the guide pin 124 is in contact with some parts of the lower walls (lower surfaces) of the link holes 157 and 177 while the clamps 158 and 178 are in the open state. Thereby, the further opening of the clamps 158 and 178 positioned at the open position even without the operation for the clamp lever 62 can be limited, and thus, the difficulty in attaching the tip tool 16 to the clamps 158 and 178 can be suppressed.
• In the electric tool 10, when the operation force on the clamp lever 62 is released while the clamps 158 and 178 are in the release state, the clamps 158 and 178 are brought into the temporarily holding state by the function of the outer periphery 65 of the push piece 64 and the function of the O-ring 136. That is, the release state can be automatically switched to the temporarily holding state, and thus, excellent workability is achieved. Further, the clamps 158 and 178 are brought into the temporarily holding state but are not brought into the clamping state. Thereby, even if a foreign material is present between the tip tool 16 and the clamps 158, 178, the clamping state is caused, and abrasion of the clamps 158, 178 and others can be prevented.
[Modification Example of First Embodiment]
• It is needless to say that the present invention is not limited to the first embodiment, and various modifications can be made within the scope of the present invention.
• A modification example of the first embodiment will be described with reference to FIGs. 20 to 22. Note that FIG. 20 illustrates a modification example of the fixing state, FIG. 21 illustrates a modification example of the temporarily holding state (at the open position), and FIG. 22 illustrates a modification example of the release state. Additionally, the reference signs in FIGs. 20 to 22 are made by addition of 200 to the reference signs of components corresponding to the above embodiment (for example, a reference sign of a unit casing according to the modification example is "292"). Note that a mainly-changed matter in the modification example is the shape of the clamp (the first clamp member 144 and the second clamp member 164). Thus, only the change will be mainly described later, and the explanation for the components with similar functions is omitted. Furthermore, illustration of the first clamp member is omitted in FIGs. 20 to 22.
• In the modification example, a shape of a link hole 357 of the clamp is different from that of the above embodiment. Further, a movable section 376 of the clamp is provided with a protrusion 376A. FIG. 20 illustrates the modification example of the fixing state. (Part of) a guide pin 324 is positioned inside a long hole section 357A. In this state, a clamp spring 334 biases a flange 318 upward, thereby biasing a clamp shaft 312 together with the guide pin 324 upward. Consequently, the guide pin 324 presses the long hole section 357A, a second clamp member 364 rotates clockwise, and a clamp 378 presses the tip tool 16 from the lower surface side. Thereby, the tip tool 16 is clamped in the up-down direction, and is fixed by a tool holding section 300.
• As illustrated in FIGs. 20 to 22, in the link hole 357, a lower surface of a larger-width section 357B has a tilt angle different from that of the elongated hole section 357A. Specifically, the lower surface of the larger-width section 357B is inclined at a greater angle with respect to the clamping direction (the up-down direction) than the lower surface of the elongated hole section 357A. That is, the lower surface of the larger-width section 357B forms a sharper angle with the up-down direction than the lower surface of the elongated hole section 357A.
• Here, the lower surface of the link hole 357 is a portion being in contact with the guide pin 324 when the second clamp member 364 rotates from the fixing position to the temporarily holding position (or the release position), and the tilt angle thereof changes the rotation amount of the second clamp member 364 with respect to the movement amount of the guide pin 324. In the present invention, in order to achieve suitable attachment/detachment of the tip tool, the clamp at the temporarily holding position needs to have a positional relationship in which the tapered section of the clamp abut on the edge (upper edge) of the hole of the unattached tip tool 16 while the holding surface of the clamp abuts on the edge (lower edge) of the hole of the tip tool 16 in the temporarily holding state. Thus, variation in the rotation amount of the clamp with respect to the operation amount of the clamp lever (the movement amount of the guide pin) causes a risk of a failure in the operations.
• Thus, in the modification example, part of the lower surface of the link hole 357 (particularly the lower surface of the larger-width section 357B in the temporarily holding state) is made sharper in the up-down direction than that of the above embodiment. Thereby, in the switching from the fixing state to the temporarily holding state, the rotation amount of the clamp at the sharped part is smaller than that of the above embodiment. Thereby, even if a dimension varies, influence of this variation on the rotation amount of the clamp is small. Therefore, the target rotation amount of the clamp can be achieved without the need of high machining accuracy.
• Further, in the modification example, the movable section 376 of the clamp is provided with the protrusion 376A. As illustrated in FIGs. 21 and 22, at least part of an O-ring 336 in the temporarily holding state or the release state moves outward (in the front-back direction) from a dent 331. However, the up-down direction movement of the moved part of the O-ring 336 is limited by the protrusion 376A, and thus, the O-ring 336 can be continuously held at a predetermined position.
[Configuration of Second Embodiment]
• An electric tool 400 as a working machine according to a second embodiment will be described. Note that the same as or similar components to the components of the electric tool 10 (FIG. 1) according to the first embodiment are denoted with the same reference signs, and will not be described. As described in detail later, the electric tool 400 is different from the electric tool 10 according to the first embodiment in a state of holding the tip tool in the temporarily holding state such that the rotation of the tip tool (particularly, the rotation by its weight) is limited while the rotation position can be changed by biasing the tip tool.
<Outline of Electric Tool>
• FIG. 23 illustrates an output shaft 414, the clamp lever 62, and the like in the electric tool 400. Note that hatching is omitted in order to clearly illustrate the shapes of the respective components. The electric tool 400 is different from the electric tool 10 (FIG. 4) because of including the output shaft 414 instead of the output shaft 90 (FIG. 4) in the drive mechanism 80 and because of using a tip tool 402. The components other than the output shaft 414 are similar to those in the electric tool 10, and will not be illustrated and described.
<Tip Tool>
• The tip tool 402 illustrated in FIG. 25 is a member extending in the front-back direction, and includes a flat plate 403 at the front side and an attachment 404 at the back side. A blade section although not illustrated is formed at the front end of the flat plate 403.
• The attachment 404 includes a plate 405 and a protrusion 406. The protrusion 406 protrudes upward from the upper surface of the plate 405. An outer periphery 406A of the protrusion 406 is shaped such that a plurality of concave sections 406B and a plurality of convex sections 406C are alternately arranged in the circumferential direction when viewed from above. The outer periphery 406A is further provided with a inclined surface 407A and a curved surface 407B.
• As illustrated in FIG. 24, the inclined surface 407A is a surface extending along an oblique direction crossing with the up-down direction. The curved surface 407B is upper than the inclined surface 407A. Additionally, the inclined surface 407A is an exemplary inclined section.
• As illustrated in FIG. 25, an upper wall 408 is formed at the upper end of the protrusion 406. The upper wall 408 is shaped into a plate shape with a thickness in the up-down direction. One hole 409, which penetrates the upper wall 408 in the up-down direction, is formed at the center of the upper wall 408. The hole 409 includes an annular insertion section 409A and two cutouts 409B extending radially outward from the insertion section 409A. A clamp 432 (FIG. 24) described later is inserted into the insertion section 409A.
<Details of Electric Tool>
• The electric tool 400 illustrated in FIG. 23 includes the motor 52 (FIG. 3), a clamp shaft 412, the clamp lever 62, and a tool holding section 430. The electric tool 400 further includes the output shaft 414.
<<Clamp Shaft>>
• The clamp shaft 412 is an exemplary output shaft which is rotated and driven around an axial line "KA" as its axis by the motor 52 (FIG. 3). The clamp shaft 412 extends from the clamp holder 126 in the up-down direction. The clamp shaft 412 is a metallic member, and includes a first shaft 412A, a second shaft 412B, a flange 412C, a support section 412D, and a guide pin 412E. The first shaft 412A, the second shaft 412B, the flange 412C, and the support section 412D are formed to be unified. The guide pin 412E is a different member from the clamp shaft 412, and is fixed to the clamp shaft 412 by press fitting. Additionally, the guide pin 412E may be unified with the clamp shaft 412 to be a single member.
• The clamp shaft 412 moves between the first position P1 and the second position P2 in the up-down direction in response to the rotation of the clamp lever 62. Additionally, the position of the clamp shaft 412 is set as, for example, a position of an upper end surface 413 of the clamp shaft 412. The second position P2 is positioned lower than the first position P1. The third position P3 as an intermediate position is present between the first position P1 and the second position P2.
<<Output Shaft>>
• The output shaft 414 in the electric tool 400 configures a portion holding and oscillating the tip tool 402. The output shaft 414 includes a unit casing 416, a support pin 424, the clamp spring 134, and an O-ring 426. The output shaft 414 is configured to rotate (swing) the clamp shaft 412 around the axial line KA.
• The unit casing 416 includes a container 417, an upper wall 418, a guide 419, a first larger-diameter section 421, and a second larger-diameter section 422. The unit casing 416 supports the tool holding section 430.
• The container 417 is a cylindrical member with an axial direction in the up-down direction. The swing arm 88 (FIG. 6) is fixed to the upper part of the container 417. The center of the container 417 in the up-down direction is in contact with the inner ring of the needle bearing 43 (FIG. 6). The lower part of the container 417 is in contact with the oil seal 44 (FIG. 6). The clamp holder 126 (FIG. 8) is housed inside the container 417.
• The upper wall 418 covers the upper end of the container 417. The guide 419 is a cylindrical member extending upward from the upper wall 418. The guide 419 is supported by the ball bearing 42 (FIG. 6) to be rotatable around the central axis along the up-down direction. A through-hole 419A is formed in the upper wall 418 and the guide 419.
• The first larger-diameter section 421 extends downward from the lower end of the container 417, and has a diameter getting larger as getting closer to the down side. The second larger-diameter section 422 extends downward from the lower end of the first larger-diameter section 421, and has a diameter getting larger as getting closer to the down side. The second larger-diameter section 422 is provided with an attachment seat 452 described later.
• The support pin 424 is an exemplary support shaft extending in the right-left direction. The support pin 424 is shaped into a columnar shape. The support pin 424 is fixed to the clamp holder 126. Both ends of the support pin 424 in the right-left direction are supported by the first larger-diameter section 421.
• The O-ring 426 is an exemplary biasing section and an exemplary annular elastic body. The O-ring 426 is an annular rubber member. When being in contact with movable sections 437 and 447 (FIG. 24) of the clamp 432 described later, the O-ring 426 biases the movable sections 437 and 447 radially inward (to bring them close to each other).
<<Tool Holding Section>>
• The tool holding section 430 includes clamps 438 and 448 of the clamp 432, and the attachment seat 452 of the unit casing 416. Additionally, the tool holding section 430 is held by the clamp shaft 412.
(Clamp Member)
• The clamp 432 illustrated in FIG. 24 is rotatable around the support pin 424. Specifically, the clamp 432 includes a first clamp member 434 and a second clamp member 444 which are rotatable around the support pin 424 in opposite directions to each other. Note that the component positions of the first clamp member 434 and the second clamp member 444 will be described in assuming that the clamps 438 and 448 described later are in contact with each other at the close position.
• The clamp 432 includes the clamps 438 and 448. The movable sections 437 and 447, which are to be biased by the O-ring 426, are provided at the other side (upper side) in the clamping direction relative to the support pin 424 of the clamp 432. Either one of the movable section 437 and the clamp 438 moves forward, and the other moves backward. Either one of the movable section 447 and the clamp 448 moves forward, and the other moves backward.
((First Clamp Member))
• The first clamp member 434 is provided with an insertion section 435, a leg 436, the movable section 437, and the clamp 438.
• The insertion section 435 configures the center of the first clamp member 434 in the up-down direction. An annular insertion hole 435A, which penetrates in the right-left direction, is formed in the insertion section 435. The support pin 424 is inserted into the insertion hole 435A. The leg 436 extends downward from the lower end of the insertion section 435.
• The movable section 437 is provided at the other side (upper side) in the clamping direction relative to the support pin 424 of the first clamp member 434. The movable section 437 is biased by the O-ring 426. A link hole 439, which penetrates in the right-left direction, is formed in the movable section 437. The link hole 439 is an exemplary link section extending in a direction crossing with the clamping direction.
• The link hole 439 includes an elongated hole section 439A at the upper side and a larger-width section 439B at the lower side. The elongated hole section 439A and the larger-width section 439B are formed to be unified. When the guide pin 412E is positioned in the elongated hole section 439A, movement of the movable section 437 is limited by the guide pin 412E.
• The up-down direction tile angle of the upper surface of the larger-width section 439B is configured to be more obtuse (have an obtuse angle) than that of the upper surface of the elongated hole section 439A. A space is formed between the larger-width section 439B and the guide pin 412E. When the guide pin 412E is positioned in the larger-width section 439B, the limitation of the movement of the movable section 437 by the guide pin 412E is weaker than that when the guide pin 412E is positioned in the elongated hole section 439A.
• The clamp 438 extends forward from the lower end of the leg 436. The clamp 438 is provided at one side (the lower side) in the clamping direction relative to the support pin 424 of the first clamp member 434. The clamp 438 has, for example, a bottom surface 438A, a tapered surface 438B, a holding surface 438C, and a facing surface 438D. A protrusion 438E, which protrudes backward, is provided at the lower end of the facing surface 438D.
• The holding surface 438C is shaped into a planar shape. Thus, when the holding surface 438C is arranged along the front-back direction and the right-left direction (horizontal direction), the holding surface 438C can hold the tip tool 402 from below. Additionally, a thickness of the tip tool or the like varies depending on its type, and thus, the holding surface 438C is not necessarily horizontal when holding the tip tool.
(Second Clamp Member)
• The second clamp member 444 includes an insertion section 445, a leg 446, a movable section 447, and a clamp 448.
• The insertion section 445 configures the center of the second clamp member 444 in the up-down direction. An annular insertion hole 166A, which penetrates in the right-left direction although not illustrated, is formed in the insertion section 445. The support pin 424 is inserted into the insertion hole. The leg 446 extends downward from the lower end of the insertion section 445.
• The movable section 447 is provided at the other side (upper side) in the clamping direction relative to the support pin 424 of the second clamp member 444. The movable section 447 is biased by the O-ring 426. The link hole 449, which penetrates in the right-left direction, is formed in the movable section 447. The link hole 449 is an exemplary link section extending in a direction crossing with the clamping direction.
• The link hole 449 includes an elongated hole section 449A at the upper side and a larger-width section 449B at the lower side. The elongated hole section 449A and the larger-width section 449B are formed to be unified. When the guide pin 412E is positioned in the elongated hole section 449A, the movement of the movable section 447 is limited by the guide pin 412E.
• The up-down direction tile angle of the upper surface of the larger-width section 449B is configured to be more obtuse (have an obtuse angle) than that of the upper surface of the elongated hole section 449A. A space is formed between the larger-width section 449B and the guide pin 412E. When the guide pin 412E is positioned in the larger-width section 449B, the limitation of the movement of the movable section 447 by the guide pin 412E is weaker than that when the guide pin 412E is positioned in the elongated hole section 449A.
• The clamp 448 extends forward from the lower end of the leg 446. The clamp 448 is provided at one side (the lower side) in the clamping direction relative to the support pin 424 of the second clamp member 444. The clamp 448 has, for example, a bottom surface 448A, a tapered surface 448B, a holding surface 448C, and a facing surface 448D. A protrusion 448E, which protrudes forward, is provided at the lower end of the facing surface 448D.
• The holding surface 448C is shaped into a planar shape. Thus, when the holding surface 448C is arranged along the front-back direction and the right-left direction (horizontal direction), the holding surface 448C can hold the tip tool 402 from below. Additionally, a thickness of the tip tool or the like varies depending on its type, and thus, the holding surface 448C is not necessarily horizontal when holding the tip tool.
• The clamps 438 and 448 are provided to be rotatable toward the different sides from each other in the front-back direction in response to the movement of the clamp lever 62 (FIG. 23) and the up-down movement of the clamp shaft 412. That is, the clamps 438 and 448 are movable in response to the movement of the clamp lever 62. The clamps 438 and 448 are rotatably supported by the support pin 424, and are switched between the open position and the close position in the front-back direction in response to their rotation. As described above, the clamps 438 and 448 are provided in the clamp holder 126 (FIG. 23) to be movable in the front-back direction in response to the rotation of the first clamp member 434 and the second clamp member 444.
(Attachment Seat)
• The attachment seat 452 and the clamps 438, 448 sandwich the tip tool 402 in the clamping direction (the up-down direction), thereby holding the tip tool 402. The attachment seat 452 is provided on an inner peripheral surface 422A of the second larger-diameter section 422. The attachment seat 452 engages with the tip tool 402 in the rotation direction around the axial line KA.
• As illustrated in FIG. 25, in the attachment seat 452, a plurality of concave sections 452A and a plurality of convex sections 452B are alternately arranged along the circumferential direction of the inner peripheral surface 422A.
• As illustrated in FIG. 24, an inclined surface 454 is formed at the lower part of the attachment seat 452, the lower part being also the lower part of the inner peripheral surface 422A. In other words, the tool holding section 430 (FIG. 23) is provided with the inclined surface 454.
• The inclined surface 454 is tilted to cross the up-down direction. Thus, when the inclined surface 454 is in contact with the tip tool 402, a reaction force, which directs obliquely downward from the inclined surface 454, acts on the tip tool 402. A component force directed inward in a radial direction of the output shaft 414 and a downward component force are acted on the tip tool 402 by the reaction force. That is, the inclined surface 454 is an exemplary reaction-force generation section.
• When the tip tool 402 rotates around the axial line KA while the tool holding section 430 (FIG. 23) is in a first state described later, the inclined surface 454 is in contact with the tip tool 402, thereby, to the tip tool 402, applying a (downward) force bringing it to be distant from the attachment seat 452. When a force in the rotation direction is applied to the tip tool 402 held by the tool holding section 430 in the first state, the inclined surface 454 is in contact with the tip tool 402. Thereby, to the tip tool 402, the inclined surface 454 applies the force bringing it to be distant from the attachment seat 452, thereby consequently causing a second state in which the engagement between the tip tool 402 and the attachment seat 452 in the rotation direction is disengaged. That is, the inclined surface 454 is an exemplary inclined section.
• The attachment seat 452 can transmit power in the rotation direction around the clamp shaft 412 (FIG. 23), to the tip tool 402, while being in contact with the tip tool 402.
<<State of Tool Holding Section>>
• Even if the operation force on the clamp lever 62 is released, the tool holding section 430 illustrated in FIG. 23 can be brought into either the fixing state or the temporarily holding state.
• The fixing state of the tool holding section 430 means a state in which the biasing force in the clamping direction is applied to the tip tool 402 to fix the tip tool 402 to the tool holding section 430. In the tool holding section 430 in the fixing state, the tip tool 402 can be fixed at a plurality of rotation positions around the axial line KA by the clamps 438 and 448. Additionally, the fixing state of the tip tool 402 is equivalent to a state in which the clamp 438 and the clamp 448 are the most distant from each other in the front-back direction while the clamps 438, 448 and the attachment seat 452 sandwich the tip tool 402. The fixing state of the tip tool 402 is similar to the fixing state of the tip tool 16 illustrated in FIG. 12 according to the first embodiment, and thus, will not be illustrated.
• The temporarily holding state of the tool holding section 430 means a state in which the biasing force in the clamping direction on the tip tool 402 is weaker than that of the fixing state. Additionally, the temporarily holding state includes the first state, and at least one of the second state and a third state.
• The first state in the temporarily holding state means a state in which the rotation of the tip tool 402 by its weight is limited while the detachment of the tip tool 402 from the tool holding section 430 is limited. As described above, the temporarily holding state includes the state in which the rotation of the tip tool 402 by its weight is limited and the state in which the detachment of the tip tool 402 from the tool holding section 430 is limited. The limitations described herein do not intend to completely prohibit the movements, and permit the movements under certain conditions. Although described in detail later, in the present embodiment, the tip tool 402 can be rotated and can be detached depending on the magnitude of the force on the tip tool 402 even in the temporarily holding state. The first state is a state in which the clamp 432 (the first clamp member 434 and the second clamp member 444) rotates in a range of 10 degrees or more and less than 20 degrees from the fixing state.
• The second state and the third state in the temporarily holding state are caused by biasing the tip tool 402 held by the tool holding section 430 in the first state.
• In the second state, while the clamps 438 and 448 restrict the detachment of the tip tool 402 from the tool holding section 430, the tip tool 402 can be rotated from one rotation position of the plurality of rotation positions to another rotation position. That is, the tool holding section 430 in the second state in the temporarily holding state rotatably holds the tip tool 402.
• In the tool holding section 430 in the temporarily holding state, the tip tool 402 can be held while the movement from one rotation position of the plurality of rotation positions toward another rotation position is restricted, or the tip tool 402 is held to permit the movement from one rotation position of the plurality of rotation positions to another rotation position when the biasing force in the rotation direction around the axial line KA on the tip tool 402 is a predetermined magnitude or more.
• In the third state, the movement of the tip tool 402 in the direction (up-down direction) along the axial line KA is permitted while the clamps 438 and 448 are held by the clamp shaft 412, and the tip tool 402 is biased to be switched between the first state and the third state, thereby enabling at least one of the attachment of the tip tool 402 to the tool holding section 430 and the detachment of the tip tool 402 from the tool holding section 430. As described above, the temporarily holding state of the tool holding section 430 includes the second state in which the tip tool 402 is rotatable and the third state in which the tip tool 402 is attachable/detachable.
• In the present embodiment, the temporarily holding state includes at least the second state. The second state is a state in which the tip tool 402 and the attachment seat 452 are distant from each other to disengage the engagement between the tip tool 402 and the attachment seat 452 in the rotation direction around the axial line KA. In other words, in the temporarily holding state, by the biasing force on the tip tool 402, the tip tool 402 and the attachment seat 452 can be made distant from each other to disengage the engagement between the tip tool 402 and the attachment seat 452 in the rotation direction around the axial line KA. The second state is a state in which the clamp 432 (the first clamp member 434 and the second clamp member 444) rotates in a range of 20 degrees or more and less than 27 degrees from the fixing state.
• Further, in the present embodiment, the temporarily holding state includes both the second state and the third state. The tool holding section 430 in the second state limits the detachment of the tip tool 402, and the third state is caused when the clamps 438 and 448 in the second state are biased via the tip tool 402.
• The third state is a state in which the clamps 448 and 438 are moved by the biasing force on the tip tool 402 to a position permitting them to pass through the hole 24 of the tip tool 402. In other words, in the temporarily holding state, the paired clamps 448 and 438 are movable to the position permitting them pass through the hole 24 of the tip tool 402. The state of FIG. 17 according to the first embodiment is also the third state. The third state is a state in which the clamp 432 (the first clamp member 434 and the second clamp member 444) rotates in a range of 27 degrees or more and 30 degrees or less from the fixing state. Additionally, the state of the rotation by 30 degrees from the fixing state is the same as the position of the clamp in the release state.
• The tool holding section 430 further has the following functions. The tool holding section 430 can hold the tip tool 402 at the plurality of rotation positions around the axial line KA. Additionally, the tool holding section 430 can be brought into a holding state to hold the tip tool 402 and a non-holding state not to hold the tip tool 402. The holding state is a state in which the tip tool 402 is held not to rotate around the axial line KA and not to be detached from the tool holding section 430.
• Furthermore, in the tool holding section 430, by the operation for only the clamp lever 62, the non-holding state can be switched to the holding state to cause the tool holding section 430 to hold the tip tool 402, and the holding state can be switched to the non-holding state to detach (remove) the tip tool 402 from the tool holding section 430 due to its weight. Note that the detachment due to its weight is caused mainly when the downward direction of the electric tool 400 coincides with the direction of gravity.
• Additionally, even if the operation force on the clamp lever 62 is released, when the tool holding section 430 is biased via the tip tool 402, the non-holding state can be switched to the holding state to cause the tool holding section 430 to hold the tip tool 402, and the holding state can be switched to the non-holding state.
• As illustrated in FIGs. 25 and 28, the tool holding section 430 in the fixing state can hold the tip tool 402 at a first position as one of the plurality of rotation positions and a second position adjacent to the first position in the rotation direction. The first position is, for example, a position of the tool holding section 430 having an arrangement relationship of FIG. 25. The second position is, for example, a position of the tool holding section 430 having an arrangement relationship of FIG. 28. Additionally, a second convex section 452B when being distant by one convex section in the rotation direction from a first convex section 452B is adjacent to the first convex section 452B.
• If the biasing force on the tip tool 402 is unloaded when the tip tool 402 is positioned at a predetermined position between the first position and the second position, the tool holding section 430 in the first state is configured such that the tip tool 402 is moved to the first position or the second position by the clamps 438 and 448.
[Function of Second Embodiment]
• As illustrated in FIG. 23, when the surface contact between the entire second surface 74 and the entire upper end surface 413 in the electric tool 400 is caused, the state of the tool holding section 430 is the first state in the temporarily holding state. In the first state, the operator can rotate (swing) the tip tool 402 around the axial line KA. Additionally, in the first state, the tool holding section 430 temporarily holds the tip tool 402, and thus, the rotation of the tip tool 402 and the detachment of the tip tool 402 from the tool holding section 430 due to its weight are limited.
• As illustrated in FIG. 26, in the tool holding section 430, the tip tool 402 can be rotated from one rotation position of the plurality of rotation positions to another rotation position while the detachment of the tip tool 402 from the tool holding section 430 is limited by the clamps 438 and 448. Another rotation position is not limited to the position adjacent to one rotation position, and can be other position than the adjacent position. During the rotation of the tip tool 402, the surface contact between the second surface 74 and the upper end surface 413 does not change.
• Additionally, the tip tool 402 is distant from the attachment seat 452 due to the force of gravity. However, when the electric tool 400 is turned upside down, the tip tool 402 is in contact with (engages with) the attachment seat 452. In the turned state, the tip tool 402 is in contact with the attachment seat 452 but is movable to be distant from the attachment seat 452. Therefore, the operator applies a force to the tip tool 402, thereby rotating the tip tool 402. Further, by part of the clamp facing the holding surface 448C, the upward movement of the tip tool 402 (as coming close to the attachment seat 452) is limited. Thus, in the temporarily holding state, the contact between the tip tool 402 and the attachment seat 452 is not stronger than that in the fixing state.
• As illustrated in FIG. 27, when the tip tool 402 starts rotating around the axial line KA, a convex section 406C is in contact with a convex section 452B in movement of the convex section 406C from a concave section 452A to its adjacent concave section 452A. Then, when the inclined surface 407A is in contact with the inclined surface 454 as illustrated in cross-section C-C, a reaction force "FA" from the attachment seat 452 acts on the tip tool 402.
• The reaction force FA is decomposed into a downward component force F1 and inward component force F2 (toward the axial line KA). The component force F2 is canceled by the other component force F2 acting on an opposite side of the tip tool 402. Thus, by the downward component force F1, the tip tool 402 is made distant downward from the attachment seat 452. That is, the state of the tool holding section 430 is the temporarily holding state, and, at the same time, is the second state in which the engagement in the rotation direction between the tip tool 402 and the attachment seat 452 is disengaged. Additionally, the tool holding section 430 in the second state limits the detachment of the tip tool 402. Specifically, in the second state, the clamps 448 and 438 do not move to the position permitting them to pass through the hole 24 of the tip tool 402.
• In the tool holding section 430, if the biasing force on the tip tool 402 is released when the tip tool 402 is positioned at a predetermined position between the first position and the second position (in the middle of the rotation), the tip tool 402 is moved to the first position or the second position by the clamps 438 and 448. In other words, when receiving the force from the tool holding section 430, the tip tool 402 in the middle of the rotation automatically rotates to the original first position (FIG. 25) or its adjacent second position (FIG. 28). This is because the movement of the clamps 448 and 438 to the open position by the biasing force from the O-ring 426 causes the upward force to be transmitted to the tip tool 402, and thus, the upward-moving tip tool 402 receives the reaction force from the inclined section to cause the component forces for rotating the tip tool 402.
• As illustrated in FIG. 28, when the operator further rotates the tip tool 402 from the position of the middle of the rotation, the tip tool 402 is positioned at the second position adjacent to the position. As described above, the operator can change the position of the tip tool 402 in the temporarily holding state in the rotation direction.
• When the clamps 438 and 448 in the second state are biased by the operator via the tip tool 402, the state of the tool holding section 430 is brought into the third state in the temporarily holding state. This state is similar to that of FIG. 17 according to the first embodiment, and thus, will not be illustrated. Additionally, in the present embodiment, a force toward the next rotation position is caused when the convex section 406C steps over the convex section 452B, and thus, a force for biasing the tip tool 402 downward is unloaded at this time. Thus, the tool holding section 430 is not brought into the third state only by the force in the rotation direction around the axial line KA. Thereby, the dropping off (detachment) of the tip tool 402 at the time of the adjustment of the rotation position is limited. Additionally, the tool holding section 430 may be brought into the third state only by the force in the rotation direction around the axial line KA. The present embodiment is configured such that the operator applies the force in the rotation direction around the axial line KA to the tip tool 402, thereby switching the first state to the second state, and that the operator applies the force along the axial line KA (the up-down direction) to the tip tool 402, thereby switching the first state to the second state or the third state.
• As described in the first embodiment, in the third state, the tip tool 402 can be moved to the attachment seat 452 in the direction (the up-down direction) along the axial line KA while the clamps 438 and 448 are held by the clamp shaft 412. Specifically, in the third state, the clamps 448 and 438 move to the position (the close position) permitting them to pass through the hole 24 of the tip tool 402. Thereby, in the temporarily holding state, when the tip tool 402 is moved upward (as coming close to the attachment seat 452), the tool holding section 430 in the temporarily holding state is switched from the first state to the third state and then to the first state, thereby attaching the tip tool 402 to the tool holding section 430. Further, when the tip tool 402 is moved downward, the tip tool 402 can be detached from the tool holding section 430.
• When the clamps 438 and 448 are moved by the operation for only the clamp lever 62, the tool holding section 430 switches the non-holding state to the holding state, and thus, the tip tool 402 can be held by the tool holding section 430. Further, the tool holding section 430 switches the non-holding state to the holding state, and thus, the tip tool 402 can be detached from the tool holding section 430 by its weight.
• Even if the operation force on the clamp lever 62 is released, when the tool holding section 430 is biased via the tip tool 402 (by, for example, the operator), the non-holding state can be switched to the holding state such that the tip tool 402 can be held by the tool holding section 430, and the holding state can be switched to the non-holding state.
• Specifically, the holding state includes the fixing state and the first state in the temporarily holding state. Further, the non-holding state includes the second and third states in the temporarily holding state and the release state. The operator can perform the switching between the fixing state and the release state by performing the operation for only the clamp lever 62, and can further perform the switching between the first state and the second (or third) state in the temporarily holding state by performing the operation for the tip tool 402 even if the operation force on the clamp lever 62 is released.
• As described above, in the electric tool 400, the position of the tip tool 402 in the rotation direction can be adjusted without being detached, and the tip tool 402 can be detached by its weight, thereby improving the workability.
[Configuration of Third Embodiment]
• An electric tool 460 as a working machine according to a third embodiment will be described. Note that the same or similar configurations as or to the configurations of the first and second embodiments are denoted with the same reference symbols, and will not be described. The similar configurations include configurations which are partially different in shape and dimension but generally similarly function.
• As similar to the configurations described in Patent Document 2, the electric tool 460 illustrated in FIG. 29 is configured such that a rotation force is transmitted by engagement between a plurality of protrusions 492 of an attachment ring 486 (attachment seat) and a plurality of through-holes 458B and their peripheries of a tip tool 456. Further, the electric tool 460 is configured such that the tip tool 456 is clamped and fixed by a tool shaft 482 inserted from the lower side of the clamp shaft 462. Thereby, the electric tool 460 is configured to limit the transmission of the rotation force to the tip tool 456 and to limit the rotation of the tip tool 456 relative to a tool holding section 480.
<Outline of Electric Tool>
• As illustrated in FIG. 29, the electric tool 460 is configured such that the tip tool 456 is replaceable with other tip tool. The electric tool 460 is a cordless multifunctional tool which is moved by power of a battery pack not illustrated. The electric tool 460, for example, oscillates the tip tool 456. Additionally, hatching is omitted in order to clearly illustrate the shapes of the respective components.
<Tip Tool>
• The tip tool 456 illustrated in FIG. 30 is a member extending in the front-back direction, and includes a flat plate 457 at the front side and an attachment 458 at the back side. A blade section not illustrated is formed at the front end of the flat plate 457.
• The attachment 458 is positioned at an oblique upside of the flat plate 457. Single hole 458A and a plurality of through-holes 458B are formed in the attachment 458. The hole 458A is formed at the center of the attachment 458. The plurality of through-holes 458B are positioned outside the hole 458A, and are annularly arranged to surround the hole 458A. The hole 458A has a size permitting a shaft main body 484 of the tool shaft 482 described later to pass therethrough. A plurality of protrusions 492 described later are inserted into the plurality of through-holes 458B. The attachment 458 further has a lower surface 458C and an upper surface 458D.
<Details of Electric Tool>
• The electric tool 460 illustrated in FIG. 29 includes the motor 52, the clamp shaft 462, the clamp lever 62, and the tool holding section 480. The electric tool 460 further includes an outer housing 468 and an output shat 472.
<<Clamp Shaft>>
• The clamp shaft 462 is an exemplary output shaft which is rotated and driven around an axial line "KB" as its axis by the motor 52. The clamp shaft 462 is supported by a unit casing 474 described later. The clamp shaft 462 is made of an upper shaft 463 and a lower shaft 464 which are arranged in the up-down direction.
• The upper shaft 463 is made of a unified member of a column 463A, a tube 463B, and a flange 463C. The column 463A extends in the up-down direction. An upper part of the column 463A protrudes to be upper than a guide 478 described later. An upper end surface 463D of the column 463A is a surface along the front-back direction and the right-left direction. The upper end surface 463D faces the push piece 64 in the up-down direction, and is positioned to be brought into contact with the push piece 64 by the rotation of the clamp lever 62.
• The flange 463C radially overhangs outward from a lower end of the tube 463B. The flange 463C is biased by the clamp spring 134 to be in contact with a lower end of an upper wall 477.
• The lower shaft 464 includes a pillar 464A and a tube 464B. The pillar 464A extends in the up-down direction. An upper part of the pillar 464A is inserted and fixed into the tube 463B. Specifically, a male screw provided on the upper part of the pillar 464A is screwed with a female screw in the tube 463B, thereby fixing the pillar 464A to the tube 463B. Additionally, the upper shaft 463 and the lower shaft 464 may be unified as a single component. A spring 465 is inserted into the tube 464B. Specifically, the spring 465 is pressed and fixed into the tube 464B. Two spiral cam grooves 466 are formed in the tube 464B. The two cam grooves 466 guide the support pin 424 of the tool shaft 482 described later, and support both ends of the support pin 424 in the axial direction.
• The clamp shaft 462 moves between the first position P1 and the second position P2 in the up-down direction in response to the rotation of the clamp lever 62. Additionally, the position of the clamp shaft 462 is illustrated as, for example, the position of the upper end surface 463D. The second position P2 is lower than the first position P1. Further, the third position P3 as an intermediate position is present between the first position P1 and the second position P2.
<<Output Shaft>>
• The output shaft 472 a portion of the electric tool 460, the portion holding and oscillating the tip tool 456. The output shaft 472 includes the unit casing 474, the support pin 424, and the clamp spring 134. The output shaft 472 can rotate (swing) the clamp shaft 462 around the axial line KB.
• The unit casing 474 includes a container 476, the upper wall 477, and the guide 478. The unit casing 474 supports the tool holding section 480.
• The container 476 is shaped into a cylindrical shape with the axial direction as the up-down direction. The swing arm 88 is fixed to the container 476. The center of the container 476 in the up-down direction is in contact with the inner ring of the needle bearing 43. The lower part of the container 476 is in contact with the oil seal 44. The clamp shaft 462, the clamp spring 134, and the shaft main body 484 described later are housed in the container 476. The attachment ring 486 described later is provided at the lower end of the container 476.
• The upper wall 477 covers the upper end of the container 476. The guide 478 is shaped into a cylindrical shape extending upward from the upper wall 477. The guide 478 is supported by the ball bearing 42 to be rotatable around the axial line KB. A through-hole 479 is formed in the upper wall 477 and the guide 478. The column 463A is inserted into the through-hole 479.
<<Tool Holding Section>>
• The tool holding section 480 illustrated in FIG. 30 includes the tool shaft 482, the attachment ring 486, a coil spring 494, and a spiral spring 496. The tool holding section 480 is held by the clamp shaft 462 and the unit casing 474.
(Tool Shaft)
• The tool shaft 482 includes the shaft main body 484, a bottom 485, and the support pin 424. The shaft main body 484, the bottom 485, and the support pin 424 are unified. The tool shaft 482 is an exemplary clamp provided at the lower part of the clamp shaft 462 to be attachable/detachable. When being attached to the clamp shaft 462, the tool shaft 482 supports the tip tool 456 from below.
• The shaft main body 484 is an attachable/detachable shaft to/from the clamp shaft 462. The shaft main body 484 is shaped into a columnar shape being around the axial line KB and extending in the up-down direction. The lower part of the shaft main body 484 has a size permitting it to be inserted into the hole 458A.
• The bottom 485 radially overhangs from the lower end of the shaft main body 484. The bottom 485 is shaped into a disk shape with a predetermined thickness in the up-down direction. An annular dent 485A around the axial line KB is formed at the upper end of the bottom 485. The bottom 485 has a size permitting it to be gripped by the operator.
• The support pin 424 protrudes in the right-left direction from the outer peripheral surface of the shaft main body 484. The support pin 424 can be inserted into the two cam grooves 466. Further, the support pin 424 is supported at the ends of the two cam grooves 466 by the clamp shaft 462. In other words, the tool shaft 482 is coupled to the clamp shaft 462.
(Attachment Ring)
• The attachment ring 486 is an exemplary attachment seat. The attachment ring 486 is provided at the lower end of the unit casing 474. The attachment ring 486 includes a first cylinder 487, a second cylinder 488, and the plurality of protrusions 492.
• The first cylinder 487 and the second cylinder 488 are unified coaxially around the axial line KB. The first cylinder 487 is upper than the second cylinder 488. An inner diameter of the first cylinder 487 is larger than an inner diameter of the second cylinder 488. A lower end of the unit casing 474 is pressed into the first cylinder 487. When the tool shaft 482 is attached to the clamp shaft 462, the lower part of the shaft main body 484 is positioned in the second cylinder 488 radially distant.
• The plurality of protrusions 492 protrude downward from the lower surface of the second cylinder 488. Each of the plurality of protrusions 492 has, for example, an upper part shaped into a columnar shape and a lower part shaped into a reverse truncated cone shape. Additionally, each of the plurality of protrusions 492 has a size permitting it to be inserted into each of the plurality of through-holes 458B of the tip tool 456 and to be in contact with the hole wall of each of the plurality of through-holes 458B. The plurality of protrusions 492 are positioned to surround the hole 458A when viewed from below.
(Coil Spring)
• The lower part of the shaft main body 484 is inserted into the coil spring 494. The coil spring 494 is positioned between an inner peripheral surface of the second cylinder 488 and an outer peripheral surface of the shaft main body 484. The coil spring 494 is elastically deformable along the up-down direction. The lower end of the coil spring 494 is in contact with the upper surface 458D of the tip tool 456. The upper end of the coil spring 494 is attached to a lower end surface of the unit casing 474. That is, the coil spring 494 is provided to apply a downward force to the tip tool 456.
(Spiral Spring)
• The spiral spring 496 is provided in the dent 485A, and can be housed in the dent 485A. The lower part of the shaft main body 484 is inserted into the spiral spring 496. The spiral spring 496 is elastically deformable along the up-down direction. The lower end of the spiral spring 496 is attached to the bottom surface of the dent 485A. The upper end of the spiral spring 496 is in contact with the bottom surface 458C of the tip tool 456. That is, the spiral spring 496 is provided to apply an upward force to the tip tool 456.
• In the tool holding section 480, the tip tool 456 is sandwiched in the up-down direction between the attachment ring 486, the coil spring 494 and the tool shaft 482, the spiral spring 496, thereby holding the tip tool 456 (in the temporarily holding state and the fixing state).
• In an assumption that a spring load N1 of the clamp spring 134, a spring load N2 of the coil spring 494, and a spring load N3 of the spiral spring 496, the electric tool 460 has a relational expression of "N3 < N2 < N1". Such a spring load means a load (biasing force) which is applied to an object by a spring. Additionally, illustration of the spring loads N1, N2, and N3 is omitted.
• In the electric tool 460, the tip tool 456 is held at a specific position in the rotation direction by the coil spring 494 and the spiral spring 496 arranged at the upper and lower sides of the tip tool 456. Further, the tip tool 456 is held at a specific position also in the up-down direction by the coil spring 494 and the spiral spring 496 arranged at the upper and lower sides thereof. The holding position in the up-down direction can be adjusted by the biasing force of the springs. In this state, when the operator applies the operation force in the rotation direction onto the tip tool 456, the tip tool 456 moves downward against the biasing force of the spiral spring 496. Then, the plurality of protrusions 492 inserted into the plurality of through-holes 458B of the tip tool 456 are detached from the plurality of through-holes 458B, and the rotation position of the tip tool 456 can be adjusted.
<<States of Tool Holding Section>>
• The tool holding section 480 illustrated in FIG. 29 can be brought into either the fixing state or the temporarily holding state even if the operation force on the clamp lever 62 is released.
• The fixing state of the tool holding section 480 means a state in which the tip tool 456 is fixed to the tool holding section 480 by the application of the biasing force in the clamping direction to the tip tool 456. In the tool holding section 480 in the fixing state, the tip tool 456 can be fixed at the plurality of rotation positions around the axial line KB.
• The temporarily holding state of the tool holding section 480 means a state in which the biasing force in the clamping direction on the tip tool 456 is weaker than that of the fixing state. Further, the temporarily holding state includes the first state and the second state.
• The first state of the temporarily holding state means a state in which the rotation of the tip tool 456 by its weight is limited and a state in which the detachment of the tip tool 456 from the tool holding section 480 is limited.
• The second state of the temporarily holding state is a state caused by biasing the tip tool 456 held by the tool holding section 480 in the first state.
• In the second state, while the tool shaft 482 restricts the detachment of the tip tool 456 from the tool holding section 480, the tip tool 456 can be rotated from one rotation position of the plurality of rotation positions toward another rotation position.
• In the tool holding section 480 in the temporarily holding state, the tip tool 456 can be held while the movement from one rotation position of the plurality of rotation positions to another rotation position is limited, or the tip tool 456 is held to permit the movement from one rotation position of the plurality of rotation positions toward another rotation position when the biasing force in the rotation direction around the axial line KB on the tip tool 456 is a predetermined magnitude or more.
• In the present embodiment, the temporarily holding state includes at least the second state. In the second state, the tip tool 456 and the attachment ring 486 can be made distant from each other to disengage the engagement between the tip tool 456 and the attachment ring 486 in the rotation direction around the axial line KB.
• Further, in the present embodiment, the temporarily holding state includes the second state. The tool holding section 480 in the second state limits the detachment of the tip tool 456.
• The tool holding section 480 further has the following functions. The tool holding section 480 can hold the tip tool 456 at the plurality of rotation positions around the axial line KB. Additionally, the tool holding section 480 can be brought into a holding state to hold the tip tool 456 and a non-holding state not to hold the tip tool 456. The holding state is a state in which the tip tool 456 is held not to rotate around the axial line KB and not to be detached from the tool holding section 480.
• Additionally, even if the operation force on the clamp lever 62 is released, when the tool holding section 480 is biased via the tip tool 456, the non-holding state can be switched to the holding state to cause the tool holding section 480 to hold the tip tool 456.
[Function of Third Embodiment]
• A function of the electric tool 460 will be described with reference to FIGs. 29 to 32.
• As illustrated in an upper part of FIG. 31, for example, at the start of working, the tip tool 456 is fixed by the tool holding section 480.
• As illustrated in D-D cross-section of FIG. 32, in the fixing state of the tool holding section 480, the protrusion 492 is inserted into the through-hole 458B, and penetrate the tip tool 456 in the up-down direction.
• Subsequently, as illustrated in FIG. 29, when the clamp lever 62 is rotated to a position illustrated with a dashed double-dotted line by the operator, the push piece 64 is in contact with the clamp shaft 462, thereby moving the clamp shaft 462 downward.
• Thereby, as illustrated in the middle part of FIG. 31, the tool shaft 482 moves (protrudes) downward from the attachment ring 486. In this case, when the tool shaft 482 is rotated by the operator, the tool shaft 482 is detached from the clamp shaft 462, thereby detaching the tip tool 456. That is, the tool holding section 480 is brought into the release state.
• To the contrary, when the tool shaft 482 is not rotated by the operator, the tool holding section 480 is brought into the temporarily holding state. In other words, the tip tool 456 is temporarily held by a balance between the spring load from the coil spring 494 and the spring load from the spiral spring 496. Because of the balance, in the tip tool 456, its rotation position can be changed by the operator's operation while its rotation by its weight is limited. This is because the upward movement of the tip tool 456 is limited by the coil spring 494 while the downward movement thereof is limited by the spiral spring 496. The change in the rotation position is difficult when the tip tool 456 is close to the upper side, and the rotation by its weight is made when the tip tool 456 is close to the lower side.
• As illustrated in E-E cross-section of FIG. 32, in the temporarily holding state of the tool holding section 480, only the lower end of the protrusion 492 is inserted into the through-hole 458B.
• Subsequently, as illustrated in the lower part of FIG. 31, when the operator rotates the tip tool 456, the tip tool 456 moves downward from the attachment ring 486.
• As illustrated in F-F cross-section of FIG. 32, since the tip tool 456 moves downward, the entire protrusion 492 is detached from the through-hole 458B. In this case, when the operator rotates the tip tool 456, the lower end of the protrusion 492 is in contact with the upper surface 456A of the tip tool 456 (including the periphery of the through-hole 458B). Then, the protrusion 492 is inserted into the different through-hole 458B. As described above, in the temporarily holding state of the tool holding section 480, the position of the tip tool 456 in the rotation direction is adjusted.
• Additionally, in the temporarily holding state of the tool holding section 480, the tip tool 456 is forcibly made distant from the plurality of protrusions 492 (the attachment ring 486), and thus, for example, even if the electric tool 460 is turned upside down, the rotation position of the tip tool 456 can be changed.
• As described above, in the electric tool 460 , the position of the tip tool 456 in the rotation direction can be adjusted without the detachment of the tip tool 456, and thus, the workability can be improved.
[Modification Example of Third Embodiment]
• FIG. 33 illustrates a temporarily holding state and a fixing state of an electric tool 500 according to a modification example of the electric tool 460 (FIG. 30) in the third embodiment.
• The electric tool 500 is different from the electric tool 460 in that the electric tool 500 includes a clamp shaft 502 instead of the clamp shaft 462 (FIG. 30) while the coil spring 494 (FIG. 30) is removed therefrom. The other components are similar to those of the electric tool 460.
• The clamp shaft 502 is an exemplary output shaft. The clamp shaft 502 is supported by the unit casing 474. The clamp shaft 502 includes the components similar to those of the clamp shaft 462 except that the tube 464B (FIG. 30) is replaced with a tube 504.
• An up-down length of the tube 504 is larger than an up-down length of the tube 464B. Thereby, in the temporarily holding state of the tip tool 456 in the electric tool 500, a lower end surface 504A of the tube 504 is in contact with the upper surface 458D of the tip tool 456. When the lower end surface 504A is in contact with the upper surface 458D, the lower end of the clamp shaft 502 biases the tip tool 456 downward.
• Further, when the clamp shaft 502 moves upward when receiving a biasing force from the clamp spring 134, the lower end surface 504A moves upward to be distant from the upper surface 458D. Thereby, the plurality of protrusions 492 are completely inserted into the plurality of through-holes 458B, and the tip tool 456 is held by (fixed to) the tool holding section 480.
• As described above, the clamp shaft 502 instead of the coil spring 494 may be in contact with the tip tool 456 (FIG. 30).
[Other Modification Example]
• A modification example not illustrated will be described below.
• In a state in which the tip tool 16 is held by the tool holding section 100 (as having a posture of extension in the front-back or right-left direction), the clamps 158 and 178 at the close position may not overlap (be on line with) the tip tool 16 when viewed in the clamping direction, while the clamps 158 and 178 at the open position may overlap (be on line with) the tip tool 16 when viewed in the clamping direction. For example, in the present embodiment, the clamps 158 and 178 are positioned close to the lower surface of the tip tool 16 after passing through the inside (the hole) of the tip tool 16. However, the clamps may support the lower surface of the tip tool 16 after passing through the outside (the outer periphery) of the tip tool 16.
• When the clamps 158 and 178 move from the open position to the close position, a force may not be transmitted from the tip tool 16 thereto. The clamps are not limited to the rotating members, and may be a pair of slide members sliding linearly (for example, in parallel to the front-back direction). Not the tapered surfaces 158B and 178B but curved surfaces may be formed in the clamps 158 and 178. That is, the clamps 158 and 178 may have a mechanism for converting the upward biasing force toward a direction of the movement of the clamps.
• The O-ring 136 may not bias the clamps 158 and 178 at the close position toward the open position. Further, the O-ring 136 may not bias the clamps 158 and 178 at the open position. The O-ring 136 may bias the clamps 158 and 178 only in the closed state, and may not necessarily bias the clamps 158 and 178 in the open state. The O-ring 136 may be used as an adjustment member for adjusting the pressing force of the tip tool 16 against the clamps 158 and 178 to an appropriate load.
• As other exemplary biasing section or other exemplary elastic body for biasing the movable sections 156 and 176, a spring member such as coil spring or disc spring may be used instead of the O-ring 136. In other words, the biasing member may not be the annular elastic body. The biasing member may bias only either one of the movable section of the first clamp member and the movable section of the second clamp member. In this case, the other movable section may be immovable.
• The support pin 132, which supports the clamps 158 and 178, may be provided to a member different from the clamp holder 126. The clamps and the movable sections may be positioned at the same side relative to the support shaft. The attachment seat 107 may not be provided.
• The link section may be not the through-hole such as the link holes 157 and 177, but may be a bottomed link groove.
• The moving section may be not limited to the member such as the push piece 64 moving the clamp shaft 112 to the third position P3 in response to the arrangement relative to the pin 46, and may be a member different from the push piece 64 to be a pressing member moving the clamp shaft 112 to the third position P3.
• The attachment seat 107 is configured to transmit the rotation force because of the concave-convex structure (the concave section 107A and the convex section 107B) to be engaged with the protrusion 21 with plurality of the concave sections 21B, but is not limited thereto. For example, protrusions may be provided to be inserted into the through-holes 26 formed in the tip tool 16 such that the rotation force is transmitted by the inserted protrusions. Additionally, in the temporarily holding state in this case, the attachment seat 107 may be distant from the first clamp member 144 and the second clamp member 164 (the holding surfaces 158D and 178D) in the up-down direction such that the protrusions are detached from the through-holes 26 (such that the engagement in the rotation direction is disengaged), thereby rotatably adjusting the orientation of the tip tool 16.
• In the electric tool 400, the temporarily holding state may include only the second state and may not include the third state. Alternatively, the temporarily holding state may include the third state and may not include the second state. The tool holding section 430 may not include the reaction force generator.
• The electric tool 400 may not include either one or both of the inclined surface 407A and the inclined surface 454. For example, both the inclined surface 407A and the inclined surface 454 may be curved surfaces.
• The electric tool 400 may be configured such that the tip tool 402 is not moved to the first position or the second position by the clamps 438 and 448 when the biasing force on the tip tool 402 is unloaded.
EXPLANATION OF REFERENCE SYMBOLS
• 10: Electric tool, 12: Outer housing, 13: Lower opening, 14: Battery pack, 15: Upper opening, 16: Tip tool, 17: Flat plate, 17A: Blade section, 18: Attachment, 19: Plate, 21: Protrusion, 21A: Outer periphery, 21B: Concave section, 21C: Protrusion, 22: Upper wall, 24: Hole, 25: Insertion section, 26: Through-hole, 27: Cutout, 32: Inner housing, 34: Motor housing, 35: Middle housing, 36: Holder, 37: Attachment, 38: Tube, 39: Support wall, 40: Control board, 41: Switch, 42: Ball bearing, 43: Needle bearing, 44: Oil seal, 46: Pin, 48: Rubber member, 52: Motor, 53: Rotary shaft, 61: Trigger, 62: Clamp lever, 63: Lever main body, 63A: Base end, 63B: Grip, 64: Push piece, 65: Outer periphery, 66: Non-contact section, 67: Surface, 68: Surface, 71: Contact section, 72: First surface, 73: Curved surface, 74: Second surface, 80: Drive mechanism, 82: Spindle, 84: Ball bearing, 86: Eccentric shaft, 88: Swing arm, 88A: Attachment, 88B: Arm, 90: Output shaft, 92: Unit casing, 94: Container, 94A: Outer peripheral surface 94B: Inner peripheral surface, 96: Upper wall, 98: Guide, 99: Through-hole, 100: Tool holding section, 102: First larger-diameter section, 103: Step surface, 104: Second larger-diameter section, 104A: Inner peripheral surface, 105: Step surface, 106: Through-hole, 107: Attachment seat, 107A: Concave section, 107B: Convex section, 108: Inclined surface, 112: Clamp shaft, 114: First shaft, 115: Upper end surface, 116: Second shaft, 118: Flange, 122: Support section, 122A: Facing wall, 122B: Facing wall, 124: Guide pin, 126: Clamp holder, 127: Base, 127A: Lower surface, 127B: Opening, 128: Longitudinal wall, 129: Lateral wall, 131: Dent, 132: Support pin, 134: Clamp spring, 136: O-ring, 137: Pressing section, 142: Clamp, 144: First clamp member, 146: Insertion section, 146A: Insertion hole, 147: Contact surface, 148: Overhang, 148A: Upper surface, 149: Curved surface, 152: Leg, 153: Facing surface, 154: Protrusion, 156: Movable section, 157: Link hole, 157A: Elongated hole section, 157B: Larger-width section, 158: Clamp, 158A: Bottom surface, 158B: Tapered surface, 158C: Side surface, 158D: Holding surface, 161: Groove, 164: Second clamp member, 166: Insertion section, 166A: Insertion hole, 167: Contact surface, 168: Overhang, 168A: Upper surface, 169: Curved surface, 172: Leg, 173: Facing surface, 174: Protrusion, 176: Movable section, 177: Link hole, 177A: Elongated hole section, 177B: Larger-width section, 178: Clamp, 178A: Bottom surface, 178B: Tapered surface, 178C: Side surface, 178D: Holding surface, 181: Groove, 210: Electric tool, 242: Ball bearing, 246: Pin, 264: Push piece, 272: First surface, 273: Curved surface, 274: Second surface, 280: Drive mechanism, 292: Unit casing, 300: Tool holding section, 312: Clamp shaft, 315: Upper end surface, 318: Flange, 324: Guide pin, 331: Dent, 332: Support pin, 334: Clamp spring, 336: O-ring, 357: Link hole, 357A: Elongated hole section, 357B: Larger-width section, 364: Second clamp member, 376: Movable section, 376A: Protrusion, 378: Clamp, 400: Electric tool, 402: Tip tool, 403: Flat plate, 404: Attachment, 405: Plate, 406: Protrusion, 406A: Outer periphery, 406B: Concave section, 406C: Convex section, 407A: Inclined surface, 407B: Curved surface, 408: Upper wall, 409: Hole, 409A: Insertion section, 409B: Cutout, 412: Clamp shaft, 412A: First shaft, 412B: Second shaft, 412C: Flange, 412D: Support section, 412E: Guide pin, 413: Upper end surface, 414: Output shaft, 416: Unit casing, 417: Container, 418: Upper wall, 419: Guide, 419A: Through-hole, 421: First larger-diameter section, 422: Second larger-diameter section, 422A: Inner peripheral surface, 424: Support pin, 426: O-ring, 430: Tool holding section, 432: Clamp, 434: First clamp member, 435: Insertion section, 435A: Insertion hole, 436: Leg, 437: Movable section, 438: Clamp, 438A: Bottom surface, 438B: Tapered surface, 438C: Holding surface, 438D: Facing surface, 438E: Protrusion, 439: Link hole, 439A: Elongated hole section, 439B: Larger-width section, 444: Second clamp member, 445: Insertion section, 446: Leg, 447: Movable section, 448: Clamp, 448A: Bottom surface, 448B: Tapered surface, 448C: Holding surface, 448D: Facing surface, 448E: Protrusion, 449: Link hole, 449A: Elongated hole section, 449B: Larger-width section, 452: Attachment seat, 452A: Concave section, 452B: Convex section, 454: Inclined surface, 456: Tip tool, 456A: Upper surface, 457: Flat plate, 458: Attachment, 458A: Hole, 458B: Through-hole, 458C: Lower surface, 458D: Upper surface, 460: Electric tool, 462: Clamp shaft, 463: Upper shaft, 463A: Column, 463B: Tube, 463C: Flange, 463D: Upper end surface, 464: Lower shaft, 464A: Column, 464B: Tube, 465: Spring, 466: Cam groove, 468: Outer housing, 472: Output shaft, 474: Unit casing, 476: Container, 477: Upper wall, 478: Guide, 479: Through-hole, 480: Tool holding section, 482: Tool shaft, 484: Shaft main body, 485: Bottom, 485A: Dent, 486: Attachment ring, 487: First cylinder, 488: Second cylinder, 492: Protrusion, 494: Coil spring, 500: Electric tool, 502: Clamp shaft, 504: Tube, 504A: Lower end surface, A1: Start point, A2: End point, C1: Center, C2: Central axis, d1: Gap, d2: Gap, d3: Gap, d4: Gap, F: Force, FA: Reaction force, F1: Component force, F2: Component force, h: Space, K: Line, KA: Axial line, KB: Axial line, L1: Distance, L2: Distance, L3: Distance, M: Reference surface, N1: Spring load, N2: Spring load, N3: Spring load, P1: First position, P2: Second position, P3: Third position, PA: Position, RW: Arrow, θ1: Angle, θ2: Angle, θ3: Angle, θ4: Angle, θA: Angle, θB: Angle, θC: Angle, θD: Angle

Claims (15)

1. A working machine comprising:

   a motor;

   an output shaft configured to be rotated and driven around an axial line by the motor;

   an operation section configured to be operated by an operator; and

   a tool holding section held by the output shaft, including a clamp movable in response to movement of the operation section, and an attachment seat for holding a tip tool by sandwiching the tip tool between the attachment seat and the clamp in a clamping direction,

   wherein the tool holding section is configured to be in either a fixing state or a temporarily holding state, the fixing state being a state in which a biasing force in the clamping direction is applied to the tip tool to fix the tip tool to the tool holding section even if an operation force on the operation section is released, the temporarily holding state being a state in which the biasing force in the clamping direction on the tip tool is weaker than the biasing force of the fixing state,

   in the tool holding section in the fixing state, the tip tool can be held at a plurality of rotation positions around the axial line by the clamp,

   the temporarily holding state includes a first state and at least one of a second state and a third state, the first state being a state in which rotation of the tip tool and detachment of the tip tool from the tool holding section are limited, the second state and the third state being caused by biasing the tip tool held by the tool holding section in the first state,

   in the second state, while the clamp limits the detachment of the tip tool from the tool holding section, the tip tool is rotatable from one rotation position of the plurality of rotation positions to another rotation position, and

   in the third state, movement of the tip tool along the axial line is permitted while the clamp is held by the output shaft, and at least one of attachment of the tip tool to the tool holding section and the detachment of the tip tool from the tool holding section is enabled by biasing the tip tool to perform switching between the first state and the third state.
2. The working machine according to claim 1,
   wherein, in the second state when the temporarily holding state includes the second state, the tip tool and the attachment seat can be made distant from each other to position engagement between the attachment seat and the tip tool in a rotation direction is disengaged.
3. The working machine according to claim 1,

   wherein the temporarily holding state includes both the second state and the third state, and

   the tool holding section in the second state limits the detachment of the tip tool, and is configured to be in the third state when the clamp in the second state is biased via the tip tool.
4. The working machine according to claim 1,

   wherein the tool holding section includes a reaction force generating section, and

   when the tool holding section in the first state rotates the tip tool around the axial line, the reaction force generating section is in contact with the tip tool, thereby applying, to the tip tool, a force in a direction of being distant from the attachment seat.
5. The working machine according to claim 1,

   wherein an inclined section is formed in at least one of the attachment seat and the tip tool, and

   when a force in a rotation direction is applied to the tip tool held by the tool holding section in the first state, the inclined section applies a force in a direction of being distant from the attachment seat to the tip tool, and, as a result, causes the second state in which engagement between the tip tool and the attachment seat in the rotation direction is disengaged.
6. The working machine according to claim 1,

   wherein, in the tool holding section in the fixing state, the tip tool can be held at a first position as one of the plurality of rotation positions or at a second position adjacent to the first position in a rotation direction, and

   in the tool holding section in the first state, when a biasing force on the tip tool is unloaded when the tip tool is positioned at a predetermined position between the first position and the second position, the tip tool is moved to the first position or the second position by the clamp.
7. A working machine comprising:

   an operation section configured to be operated by an operator; and

   a tool holding section including paired clamp members configured to open and close in response to movement of the operation section and an attachment seat configured to hold a tip tool by sandwiching the tip tool between the attachment seat and the clamp members in a clamping direction,

   wherein the tool holding section is configured to be in a fixing state or a temporarily holding state, the fixing state being a state in which the clamp members are positioned at a fixing position while a biasing force in the clamping direction is applied to the tip tool to fix the tip tool to the tool holding section, the temporarily holding state being a state in which the clamp members are positioned at a position different from the fixing position while the biasing force in the clamping direction on the tip tool is weaker than the biasing force caused when the clamp members are positioned at the fixing state,

   in the tool holding section in the temporarily holding state, the positions of the clamp members are changeable between an open position at which the tip tool can be held by the tool holding section and a close position at which the tip tool is attachable to the tool holding section or is detachable from the tool holding section, and the clamp members at the open position are movable to the close position in response to a force applied by the tip tool.
8. The working machine according to claim 7,
   wherein when the tip tool is held by the tool holding section, the clamp members at the close position do not overlap the tip tool when being viewed in the clamping direction, and the clamp members at the open position overlap the tip tool position when being viewed in the clamping direction.
9. The working machine according to claim 7,
   wherein, in the temporarily holding state, by transmission of a force from the tip tool, the clamp members can be moved from the open position to the close position to permit attachment or detachment of the tip tool to or from the tool holding section.
10. The working machine according to claim 9, further comprising
    a biasing member configured to bias and move the clamp members positioned at the close position to the open position.
11. The working machine according to claim 10,

    wherein the tool holding section includes:

    a support shaft extending in an axial direction that intersects both the clamping direction and a crossing direction crossing with the clamping direction; and

    a clamp configured to rotate around the support shaft,

    the clamp members are provided at one side in the clamping direction relative to the support shaft of the clamp, and

    a movable section configured to be biased by the biasing member is provided at the other side in the clamping direction relative to the support shaft of the clamp.
12. The working machine according to claim 11, further comprising:

    a clamp shaft configured to move between a first position and a second position in response to movement of the operation section,

    wherein when the clamp shaft is positioned at the first position, the clamp members are positioned at the fixing position,

    when the clamp shaft is positioned at the second position, the clamp members are positioned at a release position at which the holding of the tip tool is released,

    when the clamp shaft is positioned at a third position between the first position and the second position, the clamp members are brought into the temporarily holding state,

    a pin member is attached to the clamp shaft,

    the movable section is provided with a link section extending in a direction crossing with the clamping direction, and the pin member is inserted into the link section, and

    when the clamp shaft is positioned at the third position while the clamp members are positioned at the open position, open movement of the clamp members is limited by contact between the pin member and the link section.
13. A working machine comprising:

    an operation section configured to be operated by an operator;

    a clamp shaft configured to move between a first position and a second position in response to movement of the operation section;

    a tool holding section configured to hold a tip tool by applying a clamping force in a clamping direction to the tip tool; and

    a clamp provided in the tool holding section and being movable in a crossing direction crossing with the clamping direction in response to the movement of the clamp shaft,

    wherein when the clamp shaft is positioned at the first position, the clamp overlaps the tip tool in the clamping direction and is brought into a fixing state in which the tip tool is biased in the clamping direction,

    when the clamp shaft is positioned at the second position, the clamp moves in the crossing direction and is brought into a release state in which the holding of the tip tool is released, and

    by an operation for only the operation section, the fixing state can be switched to the release state, and the release state can be switched to the fixing state.
14. A working machine comprising:

    a motor;

    an output shaft configured to be rotated and driven around an axial line by the motor;

    an operation section configured to be operated by an operator; and

    a tool holding section including a clamp movable in response to movement of the operation section, and an attachment seat for holding a tip tool by sandwiching the tip tool between the attachment seat and the clamp in a clamping direction and configured to be held by the output shaft,

    wherein the tool holding section is configured to hold the tip tool at a plurality of rotation positions around the axial line, and is brought into a holding state or a non-holding state, the holding state being a state in which the tip tool is held not to permit rotation around the axial line and detachment from the tool holding section, the non-holding state being a state in which the tip tool is not held,

    in the tool holding section,

    by an operation for only the operation section, the non-holding state can be switched to the holding state to cause the tool holding section to hold the tip tool, and the holding state can be switched to the non-holding state to detach the tip tool from the tool holding section by a weight of the tip tool, and

    even when an operation force on the operation section is released, by biasing via the tip tool, the non-holding state can be switched to the holding state to cause the tool holding section to hold the tip tool, and the holding state can be switched to the non-holding state.
15. A working machine comprising:

    a motor;

    an output shaft configured to be rotated and driven around an axial line by the motor;

    an operation section configured to be operated by an operator; and

    a tool holding section configured to include a clamp movable in response to movement of the operation section, and an attachment seat for holding a tip tool by sandwiching the tip tool between the attachment seat and the clamp in a clamping direction, and configured to be held by the output shaft,

    wherein even when an operation force on the operation section is released, the tool holding section can be brought into either a fixing state or a temporarily holding state, the fixing state being a state in which a biasing force in the clamping direction is applied to the tip tool to fix the tip tool to the tool holding section, the temporarily holding state being a state in which the biasing force in the clamping direction on the tip tool is weaker than the biasing force of the fixing state, and

    in the tool holding section in the fixing state, the tip tool can be fixed at a plurality of rotation positions around the axial line by the clamp,

    in the tool holding section in the temporarily holding state, the tip tool can be held while movement from one rotation position of the plurality of rotation positions to another rotation position is limited, or the tip tool is held to permit the movement from one rotation position of the plurality of rotation positions to another rotation position when the biasing force in the rotation direction around the axial line on the tip tool is a predetermined magnitude or more.