JP2023006687A - work machine - Google Patents

Abstract

To maintain durability and suppress increase in size and cost while improving a performance of a work machine.SOLUTION: A driving machine includes: a motor; a coil spring which extends in a first direction (vertical direction) D1; and a plunger 126 which strikes a fastening tool by moving upward while compressing the coil spring when driving force of the motor is transmitted and receiving energizing force of the coil spring and moving downward when the driving force of the motor is shut off. The driving machine further includes: a guide bar 131 which guides the movement of the plunger 126 in the first direction D1; a plunger damper 138 which buffers shock when the plunger 126 reaches a bottom dead point. The guide bar 131 has a notch section 132 for avoiding contact with the plunger damper 138 at a position in a range overlapping the plunger damper 138 in the first direction D1.SELECTED DRAWING: Figure 12

Description

The present invention relates to a working machine such as a driving machine.

BACKGROUND ART As an example of a working machine, a driving machine is known which has a vertically movable plunger that moves downward by the biasing force of a coil spring to strike a fastener.

For example, Patent Document 1 describes a driving tool as described above. A driving tool is disclosed that is provided with a buffer that absorbs the impact when it reaches a point.

WO2019/087637

In the aforementioned fastening tool, if the spring force of the coil spring is increased in order to improve the performance of the fastening tool, the shock applied to the buffering portion increases, and the life of the buffering portion is shortened. On the other hand, in order to improve the life of the cushioning part, it is conceivable to enlarge the cushioning part and increase the cushioning action. It may come into contact with the contact, cracking from the contact point and damaging the cushioning part.

Further, if the guide portion is left and right separated to avoid contact between the guide portion and the cushioning portion, it becomes necessary to change the shape of the plunger, which leads to an increase in the cost of the driving tool. Furthermore, the distance between the guide portions leads to an increase in the size of the housing.

SUMMARY OF THE INVENTION An object of the present invention is to provide a work machine that maintains durability while improving performance, and that suppresses an increase in size and cost.

The work machine of the present invention includes a motor, a coil spring extending vertically, and when the driving force of the motor is transmitted, the working machine moves upward while compressing the coil spring, and when the driving force of the motor is cut off. a striking portion that moves downward under the biasing force of the coil spring and strikes the fastener; a guide portion that abuts on a side surface of the striking portion and guides the vertical movement of the striking portion; and a buffering portion that buffers the impact when the striking portion reaches the bottom dead center, and the guide portion is provided in a portion of a range overlapping the buffering portion in the vertical direction to avoid contact with the buffering portion. have a part.

ADVANTAGE OF THE INVENTION According to this invention, durability can be maintained and size increase and cost increase can be suppressed, improving the performance of a working machine.

BRIEF DESCRIPTION OF THE DRAWINGS It is a side view which shows partially broken structure of the working machine of embodiment of this invention. FIG. 2 is a cross-sectional view showing the structure taken along line AA of FIG. 1; (a) is a side view showing the state of the transmission mechanism in the maintenance mode of the work machine shown in FIG. 1, and (b) is a view of the structure of (a) viewed from arrow A. FIG. (a) is a side view showing the state of the transmission mechanism during normal standby of the working machine shown in FIG. (a) is a side view showing the state of the transmission mechanism at the top dead center position of the work machine shown in FIG. (a) is a perspective view showing the structure of a guide bar provided in the work machine shown in FIG. 1, and (b) is a rear view showing the structure of the guide bar of (a). 7(a) is a front view showing the structure of the guide bar of FIG. 6, and (b) is a cross-sectional view showing the structure taken along line AA of (a). FIG. (a) is a perspective view showing the structure of a bottom holder provided in the work machine shown in FIG. 1, and (b) is a plan view showing the structure of the bottom holder of (a). (a) is a side view showing the structure of the bottom holder in FIG. 8, and (b) is a bottom view showing the structure of the bottom holder in (a). (a) is a perspective view showing the structure of a plunger provided in the work machine shown in FIG. 1, and (b) is a bottom view showing the structure of the plunger of (a). (a) is a rear view showing the structure of the plunger of FIG. 10, and (b) is a side view showing the structure of the plunger of (a). (a) is a front view showing the positional relationship of a guide bar, a plunger, a plunger damper, and a bottom holder provided in the work machine shown in FIG. 1, and (b) is a side view of (a). (a) is a cross-sectional view showing the state before the damper is crushed in the structure cut along the line AA in FIG. 12(b), and (b) is the structure cut along the line BB in (a). It is a sectional view showing. (a) is a cross-sectional view showing the damper collapsed state in the structure taken along line AA in FIG. 12(b), and (b) is a cross-section showing the structure taken along line BB in (a). It is a diagram. FIG. 5 is a perspective view showing the positional relationship among a guide bar, a plunger, a plunger damper, and a bottom holder provided in a work machine according to a first modified example of the present invention; (a) is a side view showing the structure of FIG. 15, and (b) is a cross-sectional view showing the structure taken along line BB of (a). FIG. 11 is a perspective view showing the positional relationship among a guide bar, a plunger, a plunger damper and a bottom holder provided in a working machine according to a second modified example of the present invention; 18(a) is a side view showing the structure of FIG. 17, and (b) is a sectional view showing the structure taken along line BB of (a).

Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

In this embodiment, a driving machine will be described as an example of a working machine. The driving tool 100 shown in FIGS. 1 and 2 has a housing 111 , a striking section 112 , a magazine 113 , an electric motor (motor) 114 , a transmission mechanism 115 , a control section 116 , a battery pack 117 and a counterweight 118 . The housing 111 has a cylindrical body portion 119 , a handle 120 connected to the body portion 119 , and a motor case 121 connected to the body portion 119 . A mounting portion 122 is connected to the handle 120 and the motor case 121 . Battery pack 117 is attached to mounting portion 122 . In addition, an injection section 123 having an injection path 124 is provided at the tip of the body section 119 . That is, the injection section 123 is fixed to the body section 119 . Thereby, the operator can hold the handle 120 by hand and press the tip of the injection part 123 against the workpiece W1.

Also, the motor case 121 is arranged between the handle 120 and the magazine 113 in the direction of the centerline E1. The magazine 113 is a portion that accommodates a plurality of fasteners 125 . Fastener 125 includes a nail and is bar-shaped. The magazine 113 has a feeder that feeds the fasteners 125 contained in the magazine 113 to the injection path 124 .

The hitting part 112 is provided over the inside and outside of the body part 119 . The striking portion 112 has a striking member 112 a with a plunger 126 located within the barrel 119 and a driver blade 127 attached to the plunger 126 . The driver blade 127 is a member for driving the stopper 125, and is made of metal. A plunger 126 to which a driver blade 127 is attached is made of metal or synthetic resin.

A guide shaft 128 is provided in the trunk portion 119 . Centerline E1 passes through the center of guide shaft 128 . Guide shaft 128 is fixed to top cover 129 and bottom holder 130 .

The driving tool 100 is driven by the electric motor 114, the coil spring 136 that can be expanded and contracted in the first direction (vertical direction) D1, and the driving force of the electric motor 114, as described above, to strike the stopper 125. and a housing 111 that accommodates the electric motor 114 and the striking portion 112 therein. Here, the first direction D1 includes a third direction D3 in which the hitting part 112 hits the stopper 125 and a fourth direction D4 opposite to the third direction D3.

The housing 111 also includes a case member 111a having an opening 111e, and a lid member 111b attached to the case member 111a and covering the opening 111e. The opening 111e is formed at the end of the case member 111a in the fourth direction D4.

Here, the hitting part 112 has a plunger 126 that abuts on the end of the coil spring 136 in the third direction D3 and can hit the stopper 125 . In other words, the striking portion 112 moves upward while compressing the coil spring 136 when the driving force of the electric motor 114 is transmitted, and receives the biasing force of the coil spring 136 when the driving force of the electric motor 114 is cut off. It has a plunger 126 which moves downward by force and strikes the stop 125 . The coil spring 136 can be removed from the opening 111e when the cover member 111b is removed from the case member 111a. Note that the first direction D1 is the same direction as the direction in which the coil spring 136 expands and contracts.

Further, as shown in FIG. 2, the case member 111a is mounted facing the first case member 111c in a second direction D2 that intersects with the first direction D1. and a second case member 111d.

That is, in the driving tool 100, as shown in FIGS. 1 and 2, the housing 111 is composed of three case members: a first case member 111c, a second case member 111d, and a lid member 111b. That is, the housing 111 is divided into a first case member 111c and a second case member 111d divided into left and right sides with respect to the center line E1 of the body portion 119, and the first case member 111c and the second case member 111d. and a lid member 111b capable of covering the opening 111e formed at the end of the body portion 119 in the fourth direction D4 in a state where the is fixed. In other words, the housing 111 that holds the power unit including the coil spring 136, the counterweight 118, etc. has a three-division structure that is divided into a first case member 111c, a second case member 111d, and a lid member 111b. .

As a result, when carrying out maintenance of the fastening tool 100, that is, replacement of expendable parts, etc., simply by removing the cover member 111b, the body portion 119 such as the coil spring 136, the counterweight 118 and the plunger 126 can be removed from the opening 111e. Maintenance can be easily performed by taking out the parts housed in the housing.

A plunger 126 , a coil spring 136 , a guide shaft 128 , and a counterweight 118 that abuts on the end of the coil spring 136 in the fourth direction D<b>4 are provided in the trunk portion 119 of the housing 111 . Furthermore, inside the trunk portion 119, the drive force of the electric motor 114 drives the plunger 126 toward the end of the coil spring 136 in the fourth direction D4, and the counterweight 118 is pushed toward the coil spring 136. A transmission mechanism 115 is provided that compresses the coil spring 136 by urging it toward the end in the third direction D3. Here, the transmission mechanism 115 is a first gear 150, a second gear 151 and a third gear 152, for example. In addition, a weight damper 137 with which the counterweight 118 released from the biasing force of the transmission mechanism 115 can abut, and a plunger damper (buffer portion) 138 with which the plunger 126 can abut are provided in the trunk portion 119 . It is

Next, the details of the function and operation of each member involved in striking the fastener 125 in the fastening tool 100 will be described.

The plunger 126 is attached to the outer peripheral surface of the guide shaft 128 and is operable along the guide shaft 128 in the direction of the center line E1. The guide shaft 128 radially positions the plunger 126 about the centerline E1. Driver blade 127 is operable with plunger 126 parallel to centerline E1. A driver blade 127 is operable within the injection path 124 .

Also, the counterweight 118 is a member that suppresses reaction received by the housing 111 and is attached to the guide shaft 128 . The counterweight 118 is operable along the guide shaft 128 in the direction of the centerline E1. The guide shaft 128 radially positions the counterweight 118 with respect to the centerline E1.

The body portion 119 also includes the coil spring 136 as described above, and the coil spring 136 is disposed between the plunger 126 and the counterweight 118 in the direction of the centerline E1. For the coil spring 136, for example, a compression coil spring in which a metal wire is spirally wound can be used. The coil spring 136 can expand and contract in the direction of the center line E1. An end of the coil spring 136 on the side of the bottom holder 130 in the direction of the center line E1 contacts the plunger 126 directly or indirectly. That is, the end of the coil spring 136 on the bottom holder 130 side is provided on the plunger 126 side of the striker 112a. Therefore, the striker 112 a is driven by the force of the coil spring 136 .

On the other hand, the end of the coil spring 136 on the side of the top cover 129 in the direction of the center line E1 contacts the counterweight 118 directly or indirectly. The coil spring 136 receives compressive force in the direction of the center line E1 and accumulates elastic energy. Note that the coil spring 136 is an example of a biasing mechanism that biases the striker 112a and the counterweight 118. As shown in FIG.

The plunger 126 receives a biasing force in a third direction D3 from the coil spring 136 to approach the bottom holder 130 in the direction of the center line E1. The counterweight 118 receives from the coil spring 136 a biasing force in a fourth direction D4 that approaches the top cover 129 in the direction of the centerline E1. The third direction D3 and the fourth direction D4 are opposite to each other, and the third direction D3 and the fourth direction D4 are parallel to the centerline E1. Plunger 126 and counterweight 118 are biased by the same physical element, coil spring 136 .

Also, a weight damper 137 and a plunger damper 138 are provided in the trunk portion 119 . Weight damper 137 is arranged between top cover 129 and counterweight 118 . A plunger damper 138 is arranged between the bottom holder 130 and the plunger 126 . Both weight damper 137 and plunger damper 138 are made of synthetic rubber.

In the tool 100, the actuation of the striker 112a or the plunger 126 or the counterweight 118 respectively in the third direction D3 is called lowering. Actuation of the striker 112a or the counterweight 118, respectively, in the fourth direction D4 is referred to as raising. The striker 112a and the counterweight 118 can each reciprocate in the direction of the centerline E1.

The battery pack 117 in the driving tool 100 can be attached to and removed from the mounting portion 122 . The battery pack 117 is a DC power supply, and the electric power of the battery pack 117 can be supplied to the electric motor 114 . That is, the electric motor 114 is driven by the electric power of the battery pack 117 . Also, the control section 116 of the fastening tool 100 is provided in the mounting section 122 .

The driving tool 100 is provided with a trigger 142 and a trigger switch 143 on the handle 120, and when the operator applies an operating force to the trigger 142, the trigger switch 143 is turned on. When the operator releases the operating force applied to the trigger 142, the trigger switch 143 is turned off.

The electric motor 114 has a rotor and stator (not shown), and a motor shaft 146 is attached to the rotor. Electric motor 114 rotates motor shaft 146 when power is supplied from battery pack 117 . A speed reducer (not shown) arranged in the motor case 121 has a plurality of sets of planetary gear mechanisms, an input element 148 and an output element 149 . Input element 148 is connected to motor shaft 146 .

The transmission mechanism 115 converts the rotational force of the output element 149 into the operating force of the striking portion 112 and the operating force of the counterweight 118 . Transmission mechanism 115 has first gear 150 , second gear 151 and third gear 152 .

As shown in FIGS. 3A and 3B, the outer diameter of the first gear 150, the outer diameter of the second gear 151, and the outer diameter of the third gear 152 are the same. The second gear 151 meshes with the first gear 150 and the third gear 152 . A cam roller 157 is provided on the first gear 150 , two cam rollers 158 and 202 are provided on the second gear 151 , and two cam rollers 159 and 203 are provided on the third gear 152 . The cam roller 157 can rotate with respect to the first gear 150 . The two cam rollers 158, 202 are arranged on the same circumference. The two cam rollers 158 and 202 are rotatable relative to the second gear 151, respectively. The two cam rollers 159 and 203 are rotatable with respect to the third gear 152, respectively.

Next, a usage example of the fastening tool 100 shown in FIGS. 1 and 2 will be described with reference to FIGS. 3 to 5. FIG. 3 shows the state of the transmission mechanism in the maintenance mode of the fastening tool 100, FIG. 4 shows the state of the transmission mechanism during normal standby, and FIG. 5 shows the state of the transmission mechanism at the top dead center position.

The tool 100 has an operating mode called maintenance mode. In the maintenance mode, as shown in FIGS. 3(a) and 3(b), the weight arm portion 135 of the counterweight 118 and the cam roller 159 of the third gear 152 are not engaged with each other, and the counter The weight 118 is arranged near the end of the guide shaft 128 in the fourth direction D4 shown in FIG.

When the operator presses the tip of the injection part 123 against the workpiece W1 and the controller detects that the trigger switch 143 is turned on, the controller supplies power to the electric motor 114 to rotate the motor shaft 146 forward. Let The rotational force of the motor shaft 146 is amplified by a speed reducer (not shown) and transmitted to the first gear 150 to rotate the first gear 150 counterclockwise.

When the first gear 150 rotates counterclockwise, the second gear 151 rotates clockwise and the third gear 152 rotates counterclockwise. When the first gear 150 rotates counterclockwise and the cam roller 157 engages the first arm 167, the plunger 126 operates in the fourth direction D4 shown in FIG. 1 against the biasing force of the coil spring 136. do. That is, the striking part 112 rises. 4A and 4B, the third gear 152 rotates counterclockwise, and when the cam roller 159 engages the weight arm portion 135, the counterweight 118 moves in the third direction D3. works with That is, the counterweight 118 is lowered.

While the first gear 150 and the second gear 151 are rotating, one cam roller 158 is engaged with the second arm 160 (engagement portion 126c) while the cam roller 157 is engaged with the first arm 167 . After that, the cam roller 157 is released from the first arm 167 . Also, when one cam roller 158 is engaged with the second arm 160 (engagement portion 126c), the other cam roller 202 is engaged with the second arm as shown in FIGS. 160 (engagement portion 126c). Next, the cam roller 158 previously engaged with the second arm 160 (engaging portion 126c) is released from the second arm 160 (engaging portion 126c).

Then, when the counterweight 118 descends, the plunger 126 ascends. The counterweight 118 then reaches bottom dead center and the plunger 126 is further raised. Then, as shown in FIGS. 5(a) and 5(b), the plunger 126 reaches the top dead center. As a result, the energy of the coil spring 136 is maximally stored. After that, the two cam rollers 158 and 202 are both released from the second arm 160 (engagement portion 126c), and the coil spring 136 is also released accordingly. When the coil spring 136 is released, the plunger 126 descends due to the biasing force of the coil spring 136 . Then, when the plunger 126 begins to descend, the counterweight 118 begins to ascend due to the biasing force of the coil spring 136 .

When the plunger 126 descends, that is, when the striking portion 112 descends, the driver blade 127 strikes the stopper 125 located in the injection path 124 shown in FIG. The stopper 125 is driven into the driven material W1. After driver blade 127 hits stop 125 , plunger 126 hits plunger damper 138 . Plunger damper 138 absorbs a portion of the kinetic energy of striking portion 112 . Also, the counterweight 118 collides with the weight damper 137 . Weight damper 137 absorbs a portion of the kinetic energy of counterweight 118 .

Thus, when the striking portion 112 operates in the third direction D3 shown in FIG. 1 to strike the stopper 125, the counterweight 118 operates in a fourth direction D4 opposite to the third direction D3. do. Therefore, it is possible to reduce the recoil when the hitting part 112 hits the stopper 125 .

As shown in FIG. 2, a top cover 129 housing a weight damper 137 that absorbs part of the kinetic energy of the counterweight 118 is attached to the lid member 111b.

Next, a connection structure between the bottom holder 130 and the top cover 129 in the fastening tool 100 will be described. As shown in FIG. 2 , the bottom holder 130 and top cover 129 are connected via a guide bar (guide portion) 131 . The bottom holder 130 and the top cover 129 are restricting portions that receive the biasing force of the coil spring 136 and restrict the amount of extension of the coil spring 136 when the coil spring 136 is extended. 129 is an upper regulation portion. The guide bars 131 are located on both sides of the coil spring 136 in the second direction D2 and are connecting portions that connect the top cover 129 and the bottom holder 130 . Further, the guide bar 131 abuts on the side surface of the plunger 126 (striking portion 112) and guides the movement of the plunger 126 in the first direction D1 (vertical direction). That is, the guide bar 131 is also an elongated rail that guides the vertical movement of the plunger 126 . Also, the guide bar 131 is attached to the bottom holder 130 with screws 133 .

Further, a plunger damper (buffer portion) 138 is provided in the case member 111a to buffer the impact when the plunger 126 reaches the bottom dead center. The plunger damper 138 is arranged between the bottom holder 130 and the plunger 126 in the first direction D1 (vertical direction). Accordingly, when the plunger 126 reaches the bottom dead center and collides with the plunger damper 138 , the plunger damper 138 is crushed to absorb the impact from the plunger 126 .

The guide bar 131 of the fastening tool 100 has a notch (avoidance portion) 132 for avoiding contact with the plunger damper 138 in a portion overlapping the plunger damper 138 in the first direction D1 (vertical direction). ing. As shown in FIGS. 6 and 7, the guide bar 131 includes a first portion 131a located in a range overlapping the plunger damper 138 shown in FIG. and a second portion 131b located in a range not overlapping the plunger damper 138 at D1. In other words, the guide bar 131 has a first portion 131a and a second portion 131b, the first portion 131a overlapping the plunger damper 138, and the second portion 131b overlapping the plunger damper 138. Absent. Further, as shown in FIGS. 6B and 7A, the guide bar 131 is formed with a plurality of through holes 131e for fixing screws.

In addition, the guide bar 131 has a vertical wall portion 131c facing the plunger damper 138 shown in FIG. As shown in FIGS. 7(a) and 7(b), a notch portion 132 is provided as an avoidance portion for avoiding contact with the plunger damper 138 in the first portion 131a of the standing wall portion 131c. That is, the notch 132 is a portion that is recessed from the upper end portion 131 d of the notch 132 and is also a portion that is recessed in the direction away from the plunger damper 138 . Note that the cutout portion 132 is provided in the first portion 131a of the standing wall portion 131c, but is not provided in the second portion 131b.

Next, the structure of the bottom holder 130 will be described with reference to FIGS. 8 and 9. FIG. The bottom holder 130 includes a substantially circular damper mounting portion 130c on which the plunger damper 138 shown in FIG. 130b and . As shown in FIGS. 8(b) and 9(b), the two connection portions 130b are provided at positions facing each other on the outer periphery of the damper mounting portion 130c. A guide bar 131 is screwed.

Further, as shown in FIGS. 8A and 9A, two support portions 130a are provided on the outer peripheral portion of the damper mounting portion 130c. These two support portions 130a are guide portions that support the plunger damper 138 when the plunger damper 138 receives an impact from the plunger 126 and is crushed. Therefore, the two support portions 130a are formed in a curvature shape with a relatively large radius so that the plunger damper 138 will not be damaged when the collapsed plunger damper 138 comes into contact with them.

Next, the structure of the plunger 126 will be described with reference to FIGS. 10 and 11. FIG. The plunger 126 moves in a first direction D1 (vertical direction) along a guide shaft 128 shown in FIG. and an abutment surface 126h located on the opposite side of the spring holding portion 126i and in contact with the plunger damper 138. As shown in FIG. In addition, the plunger 126 is provided on the outer periphery of the spring holding portion 126i and is provided on the outer periphery of the two side engaging portions 126b and the spring holding portion 126i. 4, and an engaging portion 126c that engages with the cam roller 202 shown in FIG. Further, the plunger 126 is provided on the outer periphery of the spring holding portion 126i and has a protrusion 126d that engages with the cam roller 157 shown in FIG. and a blade holding portion 126g for holding the driver blade 127 shown in FIG. The projecting portion 126d is provided to project downward from the spring holding portion 126i of the plunger 126. As shown in FIG.

The side engaging portion 126b of the plunger 126 is guided by the guide bar 131 to move in the first direction D1 (vertical direction), and the guide bar 131 also restricts the plunger 126 from rotating in the circumferential direction. Specifically, the side engaging portion 126b of the plunger 126 is guided in movement in the first direction D1 (vertical direction) by the standing wall portion 131c of the guide bar 131 shown in FIG. Rotation in the circumferential direction is also restricted.

A right side rib 126j, a left side rib 126k, and a rear side rib 126l are provided on the outer periphery of the spring holding portion 126i of the plunger 126 so as to stand from the spring holding portion 126i in the first direction D1 (vertical direction). Between each of the two side engaging portions 126b and the blade holding portion 126g in the circumferential direction about the plunger shaft 126a, a right rib 126j and a left rib 126k are provided so as to sandwich the blade holding portion 126g. A rear rib 126l including a second arm 160 (engaging portion 126c) is provided. In other words, a right rib 126j, a side engaging portion 126b, a rear rib 126l, a side engaging portion 126b, and a left rib 126k are continuously provided from the blade holding portion 126g in the circumferential direction about the plunger shaft 126a. and surrounds the entire circumference of the spring holding portion 126i. Further, an inclined rib 126m is provided so as to bridge the second arm 160 (engagement portion 126c) and the spring holding portion 126i. The upper end of the inclined rib 126m is inclined with respect to the first direction D1 (vertical direction) so as to connect the upper end of the second arm 160 (engagement portion 126c) and the upper surface of the spring holding portion 126i. According to the above configuration, it is possible to prevent the plunger 126 from being damaged by an impact during operation. The plunger 126 operates because the radial distance L3 from the axis of the plunger shaft 126a to the apex of the blade holding portion 126g is longer than the radial distance L4 from the axis of the plunger shaft 126a to the apex of the engaging portion 126c. There is a risk that the spring holding portion 126i may be bent vertically and damaged due to the impact of the time, but the spring holding portion 126i is reinforced by the right rib 126j, left rib 126k, rear rib 126l, and inclined rib 126m, so the spring holding portion 126i is not damaged. is suppressed.

Due to the respective structures of the guide bar 131, the bottom holder 130 and the plunger 126 as described above, the positional relationship between the guide bar 131, the bottom holder 130, the plunger 126 and the plunger damper 138 is as shown in FIG. It's becoming That is, the plunger 126, the plunger damper 138, and the bottom holder 130 are arranged between two guide bars 131 arranged to face each other. It is arranged between the plunger 126 and the bottom holder 130 .

Here, FIG. 13 shows the state immediately before the plunger 126 reaches the bottom dead center and before the plunger damper 138 is crushed, and FIG. 138 indicates a collapsed state. In the fastening tool 100 of the present embodiment, a cutout portion 132 is provided in the vertical wall portion 131c of the first portion 131a of the guide bar 131 shown in FIG. Accordingly, the first portion 131a of the guide bar 131 is further away from the plunger damper 138 than the second portion 131b of the guide bar 131 is. Specifically, as shown in FIG. 13(b), in the standing wall portion 131c of the guide bar 131, the notch position P2 of the standing wall portion 131c is located farther from the plunger damper 138 than the upper end position P1 of the standing wall portion 131c. The distance L2 between the notch position P2 and the plunger damper 138 in the horizontal direction is greater than the distance L1 between the upper end position P1 and the plunger damper 138 in the horizontal direction. That is, the position of the bottom portion 132a of the notch portion 132 (notch portion position P2) shown in FIG. In other words, the plunger damper 138 has a circular planar shape. The position of the bottom portion 132a of the notch portion 132 of the guide bar 131 (notch portion position P2) is located farther from the outer peripheral portion of the circular plunger damper 138 than the upper end portion position P1 of the standing wall portion 131c. In other words, the position of the bottom portion 132a of the notch portion 132 (notch portion position P2) is located farther from the center C1 of the circular plunger damper 138 than the upper end portion position P1 of the standing wall portion 131c. . That is, the distance from the center C1 of the plunger damper 138 to the position of the bottom 132a of the notch 132 (notch position P2) is longer than the distance from the center C1 of the plunger damper 138 to the upper end position P1 of the standing wall 131c.

As a result, as shown in FIG. 14, even if the plunger 126 reaches the bottom dead center and impacts the plunger damper 138 and the plunger damper 138 is crushed, the outer peripheral portion of the plunger damper 138 is The notch 132 provided in the vertical wall portion 131c of the first portion 131a of the guide bar 131 is not contacted. As a result, damage to the plunger damper 138 can be suppressed. In addition, the distance from the outer peripheral portion of the plunger damper 138 to the position of the bottom portion 132a of the notch portion 132 (notch portion position P2) is longer than the distance from the outer peripheral portion of the plunger damper 138 to the upper end portion position P1 of the standing wall portion 131c. , the planar shape of the plunger damper 138 can be enlarged. As a result, the vibration of the fastening tool main body can be reduced, so the performance of the fastening tool 100 can be improved. Furthermore, the increased size of the plunger damper 138 allows the durability of the fastening tool 100 to be maintained. That is, it is possible to maintain the durability while improving the performance of the fastening tool 100 .

Furthermore, since the notch portion 132 is provided in the standing wall portion 131c of the guide bar 131, the size of the plunger damper 138 can be increased without widening the installation interval between the two guide bars 131 arranged to face each other. . As a result, the performance of the fastening tool 100 can be improved by suppressing an increase in the size and cost of the fastening tool 100 .

Further, the notch portion 132 of the guide bar 131 is provided in the first portion 131a of the standing wall portion 131c, but is not provided in the second portion 131b. As shown in FIG. 6, in the guide bar 131, the length of the first portion 131a is much shorter than the length of the second portion 131b. Since the impact when the plunger 126 collides with the plunger damper 138 is also applied to the guide bar 131, the guide bar 131 preferably has high rigidity. In other words, since the length of the first portion 131a is much shorter than the length of the second portion 131b, the decrease in rigidity of the guide bar 131 can be minimized. In addition, since the notch 132 is not provided in the second portion 131b, the function of restricting the circumferential rotation of the plunger 126 of the guide bar 131 can be ensured.

As shown in FIG. 6, in the guide bar 131, the upper end 131d of the vertical wall portion 131c and the bottom 132a of the notch 132 are inclined away from the plunger damper 138 gradually from the upper end 131d toward the bottom 132a. are connected by a portion 132b. That is, in the cutout portion 132 of the standing wall portion 131c, the upper end portion 131d and the bottom portion 132a are connected by an inclined portion 132b inclined with respect to the upper end portion 131d or the bottom portion 132a. In other words, the change in the cross-sectional area of the notch 132 can be smoothed. As a result, stress concentration at the notch 132 when the impact from the plunger 126 propagates to the guide bar 131 can be suppressed. As a result, damage to the guide bar 131 can be suppressed.

Further, as shown in FIG. 10(b), the protrusion 126d of the plunger 126 is provided with an arc-shaped notch 126e around the center C1 of the plunger damper 138. As shown in FIG. Note that the notch portion 126e is a relief portion for preventing the outer peripheral portion of the plunger damper 138 from interfering with the projecting portion 126d when the plunger damper 138 is crushed by the impact of the plunger 126. 3(b), the protrusion 126d is a member that engages with the cam roller 157 to lift the plunger 126 against the urging force of the coil spring 136 when the plunger 126 is lifted. . Therefore, the protrusion 126d also requires high rigidity. Therefore, by providing an arcuate cutout portion 126e around the center C1 of the plunger damper 138 in the projection portion 126d, the volume of the portion to be removed in the projection portion 126d is minimized, and the outer peripheral portion of the plunger damper 138 protrudes. Damage to the plunger damper 138 due to contact with the portion 126d can be suppressed.

Next, a modified example of this embodiment will be described.

A first modification shown in FIGS. 15 and 16 is a case where the guide bar 131 is a plate-like member and does not have the vertical wall portion 131c shown in FIG. In the structure shown in FIG. 15 as well, the first portion 131a of the guide bar 131 is provided with an avoidance portion for avoiding interference with the plunger damper 138. As shown in FIG. The avoidance portion in the structure of FIG. 15 is a stepped portion 131f formed by bending the first portion 131a of the guide bar 131 in a direction away from the plunger damper 138. As shown in FIG. Thereby, as shown in FIG. 16(b), in the guide bar 131, the stepped portion 131f can be kept away from the plunger damper 138. As shown in FIG. As shown in FIG. 16(a), the guide bar 131 is formed with a slit 131g, and the engaging portion 126f of the plunger 126 is engaged with the slit 131g, so that the plunger 126 is guided. Guided by the bar 131, it moves in the first direction D1. As described above, even in the first modification, it is possible to suppress the interference of the plunger damper 138 with the guide bar 131, so that the damage of the plunger damper 138 can be suppressed. In addition, it is possible to increase the size of the plunger damper 138, thereby improving the performance of the fastening tool.

In the second modification shown in FIGS. 17 and 18 as well, the guide bar 131 is a plate-like member and does not have the vertical wall portion 131c shown in FIG. In the structure shown in FIG. 17 as well, the first portion 131a of the guide bar 131 is provided with an avoidance portion for avoiding interference with the plunger damper 138. As shown in FIG. The avoidance portion is a through hole 131h provided in the first portion 131a of the guide bar 131 to avoid interference with the plunger damper 138. As shown in FIG. Accordingly, as shown in FIG. 18(b), interference between the guide bar 131 and the plunger damper 138 can be suppressed by providing the through hole 131h in the first portion 131a of the guide bar 131. As shown in FIG. As shown in FIG. 18A, the guide bar 131 is formed with a slit 131g, and the engaging portion 126f of the plunger 126 is engaged with the slit 131g, so that the plunger 126 can be guided. Guided by the bar 131, it moves in the first direction D1. As described above, even in the second modification, it is possible to suppress the interference of the plunger damper 138 with the guide bar 131, so that the damage of the plunger damper 138 can be suppressed. In addition, it is possible to increase the size of the plunger damper 138, thereby improving the performance of the fastening tool.

The present invention is not limited to the above embodiments, and can be modified in various ways without departing from the scope of the invention. For example, in the above-described embodiment, the guide bar 131 has the avoidance portion provided in the first portion 131a. may also be provided.

DESCRIPTION OF SYMBOLS 100... Driving machine (working machine), 111... Housing, 111a... Case member, 111b... Lid member, 111c... First case member, 111d... Second case member, 111e... Opening, 112... Impact part, DESCRIPTION OF SYMBOLS 112a... Striker, 113... Magazine, 114... Electric motor (motor), 115... Transmission mechanism, 116... Control part, 117... Battery pack, 118... Counterweight, 119... Body part, 120... Handle, 121... Motor case , 122... Mounting part 123... Ejection part 124... Ejection path 125... Stopper 126... Plunger 126a... Plunger shaft 126b... Side engaging part 126c... Engaging part 126d... Protruding part 126e... Notch portion 126f Engagement portion 126g Blade holding portion 126h Collision surface 126i Spring holding portion 126j Right rib 126k Left rib 126l Rear rib 126m Inclined rib 127 Driver blade 128 Guide shaft 129 Top cover (upper regulation part) 130 Bottom holder (lower regulation part) 130a Support part 130b Connection part 130c Damper mounting part 131 Guide bar (Guiding part, connecting part) 131a... First part 131b... Second part 131c... Standing wall part 131d... Upper end part 131e... Through hole 131f... Stepped part (avoidance part) 131g... Slit 131h... Through hole (avoidance portion) 132 Notch portion (avoidance portion) 132a Bottom portion 132b Inclined portion 133 Screw 135 Weight arm portion 136 Coil spring 137 Weight damper 138 Plunger damper ( buffer part), 142... trigger, 143... trigger switch, 146... motor shaft, 148... input element, 149... output element, 150... first gear, 151... second gear, 152... third gear, 157, 158, 159, 202, 203 Cam rollers 160 Second arm 167 First arm C1 Center D1 First direction (vertical direction) D2 Second direction (horizontal direction) D3 Third direction, D4... fourth direction, E1... center line, L1, L2, L3, L4... distance, P1... top end position, P2... notch position, W1... workpiece to be driven

Claims (6)

a motor;
A coil spring extending vertically,
When the driving force of the motor is transmitted, it moves upward while compressing the coil spring, and when the driving force of the motor is interrupted, it moves downward under the biasing force of the coil spring, a striking part that strikes the
a guide portion that abuts on the side surface of the hitting portion and guides the vertical movement of the hitting portion;
a buffering portion that buffers the impact when the hitting portion reaches the bottom dead center;
has
The work machine, wherein the guide part has an avoidance part that avoids contact with the buffer part in a range overlapping the buffer part in the vertical direction. an upper restricting portion and a lower restricting portion that receive the biasing force of the coil spring and restrict the amount of extension of the coil spring when the coil spring is extended;
the guide portion is a connecting portion positioned on the side of the coil spring and connecting the upper restricting portion and the lower restricting portion;
The work machine according to claim 1, wherein the buffer portion is arranged between the lower regulating portion and the striking portion in the vertical direction. The connecting portion is arranged side by side in the left-right direction with respect to the buffering portion. having a portion and
The work machine according to claim 2, wherein the first portion forms the avoidance portion by being separated from the buffer portion in the lateral direction by a distance greater than that of the second portion. The connecting portion includes an upright wall portion that stands upright in the left-right direction toward the buffer portion,
The work machine according to claim 3, wherein the first portion of the standing wall portion is provided with a notch portion as the avoidance portion. 5. The working machine according to claim 4, wherein the upper end portion of said standing wall portion and the bottom portion of said notch portion are connected by an inclined portion gradually separating from said buffer portion from said upper end portion toward said bottom portion. The hitting part has a protrusion projecting downward from the hitting part,
The buffer portion has a circular planar shape,
The working machine according to any one of claims 1 to 5, wherein an arcuate notch centered on the center of the cushioning portion is formed in the protrusion.

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