Work equipment

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

[Technical Field]

[0001] The present invention relates to a work machine such as a driving machine. [Background technology]

[0002] 2. Description of the Related Art A known example of a work machine is a driving tool that has a plunger that can move up and down and that strikes a fastener by moving the plunger downward using the biasing force of a coil spring.

[0003] As an example of the above-mentioned driving machine, Patent Document 1 discloses a driving machine that is provided with guide sections on both sides of the plunger that come into contact with the plunger and guide the plunger's movement in the vertical direction, and a buffer section that absorbs the impact when the plunger reaches the bottom dead center. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 087637 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned driving tool, if the spring force of the coil spring is increased to improve the performance of the driving tool, the impact on the buffer part will increase and the lifespan of the buffer part will be shortened. On the other hand, in order to improve the lifespan of the buffer part, it is possible to increase the buffer part's size to increase the buffering effect, but if the buffer part is made larger, it may come into contact with the guide part when it is deformed by the impact, and cracks may form at the contact point, causing the buffer part to break.

[0006] Furthermore, if the guide parts are spaced apart to avoid contact between them and the buffer part, it becomes necessary to change the shape of the plunger, which increases the cost of the driver. Furthermore, the spacing of the guide parts also leads to an increase in the size of the housing.

[0007] An object of the present invention is to provide a work machine that improves performance while maintaining durability and suppressing increases in size and cost. [Means for solving the problem]

[0008] The working machine of the present invention comprises a motor, a coil spring extending in a vertical direction, a striking portion that moves upward while compressing the coil spring when a driving force of the motor is transmitted, and moves downward by the biasing force of the coil spring when the driving force of the motor is cut off, and strikes a stopper, a guide portion that abuts against a side surface of the striking portion and guides the movement of the striking portion in the vertical direction, and a buffer portion that buffers the impact when the striking portion reaches bottom dead center, and the guide portion has an avoidance portion that avoids contact with the buffer portion in a range that overlaps with the buffer portion in the vertical direction, and the guide portion is arranged alongside the buffer section in the left-right direction, and has a first portion located in a range overlapping with the buffer section in the up-down direction, and a second portion located in a range not overlapping with the buffer section in the up-down direction, the first portion forms the avoidance section by making the left-right distance between the end of the first portion on the buffer section side in the left-right direction and the end of the buffer section on the guide section side in the left-right direction larger than the left-right distance between the end of the second portion on the buffer section side in the left-right direction and the end of the buffer section on the guide section side in the left-right direction, and the buffer section When the impact part reaches the bottom dead center The cushioning portion further includes a shaft portion that does not abut against the guide portion around the entire circumference centered on a center line that penetrates the cushioning portion in the vertical direction, is fixed to the guide portion, and penetrates the cushioning portion in the vertical direction. [Effects of the Invention]

[0009] According to the present invention, it is possible to improve the performance of a work machine while maintaining durability and suppressing increases in size and cost. [Brief explanation of the drawings]

[0010] [Figure 1]1 is a side view showing a partially cutaway structure of a working machine according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view showing the structure cut along the line AA in FIG. [Figure 3] 2A is a side view showing the state of the transmission mechanism of the working machine shown in FIG. 1 in a maintenance mode, and FIG. 2B is a view of the structure of FIG. 2A as seen from the arrow A. FIG. [Figure 4] 2A is a side view showing the state of the transmission mechanism of the working machine shown in FIG. 1 in normal standby mode, and FIG. 2B is a view of the structure of FIG. 2A as seen from the arrow A. FIG. [Figure 5] 2A is a side view showing the state of the transmission mechanism at the top dead center position of the work machine shown in FIG. 1, and FIG. 2B is a view of the structure of FIG. 2A as seen from the arrow A. FIG. [Figure 6] FIG. 2(a) is a perspective view showing the structure of a guide bar provided in the work machine shown in FIG. 1, and FIG. 2(b) is a rear view showing the structure of the guide bar in FIG. [Figure 7] 7A is a front view showing the structure of the guide bar in FIG. 6, and FIG. 7B is a cross-sectional view showing the structure cut along line AA in FIG. [Figure 8] FIG. 2(a) is a perspective view showing the structure of a bottom holder provided in the work machine shown in FIG. 1, and FIG. 2(b) is a plan view showing the structure of the bottom holder of FIG. [Figure 9] 9(a) is a side view showing the structure of the bottom holder in FIG. 8, and FIG. 9(b) is a bottom view showing the structure of the bottom holder in FIG. [Figure 10] 2(a) is a perspective view showing the structure of a plunger provided in the working machine shown in FIG. 1, and FIG. 2(b) is a bottom view showing the structure of the plunger in FIG. [Figure 11] 11(a) is a rear view showing the structure of the plunger in FIG. 10, and (b) is a side view showing the structure of the plunger in (a). [Figure 12] 2A is a front view showing the positional relationship of a guide bar, a plunger, a plunger damper, and a bottom holder provided in the working machine shown in FIG. 1, and FIG. 2B is a side view of FIG. 2A. [Figure 13]12(a) is a cross-sectional view showing the state before the damper collapses in the structure taken along line AA in FIG. 12(b), and FIG. 12(b) is a cross-sectional view showing the structure taken along line BB in FIG. 12(a). [Figure 14] 12(a) is a cross-sectional view showing the collapsed state of the damper in the structure cut along line AA in FIG. 12(b), and FIG. 12(b) is a cross-sectional view showing the structure cut along line BB in FIG. 12(a). [Figure 15] FIG. 10 is a perspective view showing the positional relationship between 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. [Figure 16] 16(a) is a side view showing the structure of FIG. 15, and FIG. 16(b) is a cross-sectional view showing the structure cut along line BB in FIG. 16(a). [Figure 17] FIG. 10 is a perspective view showing the positional relationship between a guide bar, a plunger, a plunger damper, and a bottom holder provided in a work machine according to a second modified example of the present invention. [Figure 18] 18(a) is a side view showing the structure of FIG. 17, and FIG. 18(b) is a cross-sectional view showing the structure cut along line BB in FIG. 18(a). DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

[0012] In this embodiment, a driving machine will be described as an example of a work machine. The driving machine 100 shown in FIGS. 1 and 2 includes a housing 111, a striking unit 112, a magazine 113, an electric motor (motor) 114, a transmission mechanism 115, a control unit 116, a battery pack 117, and a counterweight 118. The housing 111 includes a cylindrical body 119, a handle 120 connected to the body 119, and a motor case 121 connected to the body 119. A mounting unit 122 is connected to the handle 120 and the motor case 121. The battery pack 117 is attached to the mounting unit 122. An ejection unit 123 having an ejection passage 124 is provided at the tip of the body 119. That is, the ejection unit 123 is fixed to the body 119. This allows an operator to grip the handle 120 and press the tip of the ejection unit 123 against the workpiece W1.

[0013] The motor case 121 is disposed between the handle 120 and the magazine 113 in the direction of the center line E1. The magazine 113 houses a plurality of fasteners 125. The fasteners 125 include nails and are rod-shaped. The magazine 113 has a feeder that sends the fasteners 125 housed in the magazine 113 to the ejection path 124.

[0014] The striking portion 112 is provided on both the inside and outside of the body portion 119. The striking portion 112 has a striking element 112a that includes a plunger 126 disposed inside the body portion 119 and a driver blade 127 attached to the plunger 126. The driver blade 127 is a member used to drive the fastener 125 and is made of metal. The plunger 126 to which the driver blade 127 is attached is made of metal or synthetic resin.

[0015] A guide shaft 128 is provided inside the body 119. A center line E1 passes through the center of the guide shaft 128. The guide shaft 128 is fixed to a top cover 129 and a bottom holder .

[0016] As described above, the driving tool 100 has the electric motor 114, the coil spring 136 that can expand and contract in the first direction (up and down direction) D1, the striking unit 112 that is driven by the driving force of the electric motor 114 and strikes the fastener 125 while moving back and forth in the first direction D1, and the housing 111 that houses the electric motor 114 and the striking unit 112. Here, the first direction D1 includes a third direction D3 in which the striking unit 112 strikes the fastener 125, and a fourth direction D4 that is the direction opposite to the third direction D3.

[0017] The housing 111 also includes a case member 111a having an opening 111e, and a cover member 111b attached to the case member 111a and covering the opening 111e. The opening 111e is formed at an end of the case member 111a in the fourth direction D4.

[0018] Here, striking portion 112 has plunger 126 that abuts against the end of coil spring 136 in the third direction D3 and can strike stopper 125. In other words, striking portion 112 has plunger 126 that moves upward while compressing coil spring 136 when the driving force of electric motor 114 is transmitted, and moves downward by the biasing force of coil spring 136 when the driving force of electric motor 114 is cut off, and strikes stopper 125. Coil spring 136 can be removed from opening 111e when cover member 111b is removed from case member 111a. Note that first direction D1 is the same direction as the expansion and contraction direction of coil spring 136.

[0019] Also, as shown in FIG. 2, the case member 111a includes a first case member 111c and a second case member 111d that is attached opposite the first case member 111c in a second direction D2 that intersects with the first direction D1.

[0020] 1 and 2, the driving tool 100 has a housing 111 that is made up of three case members: a first case member 111c, a second case member 111d, and a cover member 111b. Specifically, the housing 111 is made up of the first case member 111c and the second case member 111d, which are divided into left and right halves based on the center line E1 of the body 119, and the cover member 111b, which can close an opening 111e formed at the end of the body 119 in the fourth direction D4 when the first case member 111c and the second case member 111d are fixed together. In other words, the housing 111, which holds the power unit including the coil spring 136, the counterweight 118, etc., has a three-part structure that can be divided into the first case member 111c, the second case member 111d, and the cover member 111b.

[0021] As a result, when performing maintenance on the driving tool 100, i.e., replacing consumable parts, etc., maintenance can be easily performed by simply removing the cover member 111b and taking out the parts housed in the body 119, such as the coil spring 136, counterweight 118, and plunger 126, through the opening 111e.

[0022] A plunger 126, a coil spring 136, a guide shaft 128, and a counterweight 118 that abuts against the end of the coil spring 136 in the fourth direction D4 are provided within a body 119 of the housing 111. Further, a transmission mechanism 115 is provided within the body 119. The transmission mechanism 115 is driven by the driving force of the electric motor 114 to urge the plunger 126 toward the end of the coil spring 136 in the fourth direction D4 and to urge the counterweight 118 toward the end of the coil spring 136 in the third direction D3, thereby compressing the coil spring 136. Here, the transmission mechanism 115 is, for example, a first gear 150, a second gear 151, and a third gear 152. Also provided within the body 119 are a weight damper 137 against which the counterweight 118, released from the biasing force of the transmission mechanism 115, can come into contact, and a plunger damper (buffer part) 138 against which the plunger 126 can come into contact.

[0023] Next, the function and operation of each member involved in striking the fastener 125 in the driving tool 100 will be described in detail.

[0024] 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 positions the plunger 126 radially about the center line E1. The driver blade 127 is operable together with the plunger 126 in a direction parallel to the center line E1. The driver blade 127 is operable within the injection path 124.

[0025] The counterweight 118 is a member that suppresses the reaction force received by the housing 111, and is attached to a guide shaft 128. The counterweight 118 is movable in the direction of the center line E1 along the guide shaft 128. The guide shaft 128 positions the counterweight 118 radially relative to the center line E1.

[0026] As described above, the coil spring 136 is provided within the body 119 and is disposed between the plunger 126 and the counterweight 118 in the direction of the center line E1. For example, the coil spring 136 may be a compression coil spring in which a metal wire is wound in a spiral shape. The coil spring 136 is expandable and contractible in the direction of the center line E1. The end of the coil spring 136 on the bottom holder 130 side in the direction of the center line E1 directly or indirectly contacts the plunger 126. 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 112a is driven by the force of the coil spring 136.

[0027] Meanwhile, the end of the coil spring 136 on the top cover 129 side in the direction of the center line E1 directly or indirectly contacts the counterweight 118. The coil spring 136 receives a compressive force in the direction of the center line E1 and stores elastic energy. The coil spring 136 is an example of a biasing mechanism that biases the striker 112a and the counterweight 118.

[0028] The plunger 126 receives a biasing force from the coil spring 136 in a third direction D3 that moves it toward the bottom holder 130 in the direction of the center line E1. The counterweight 118 receives a biasing force from the coil spring 136 in a fourth direction D4 that moves it toward the top cover 129 in the direction of the center line E1. The third direction D3 and the fourth direction D4 are opposite to each other and are parallel to the center line E1. The plunger 126 and the counterweight 118 receive a biasing force from the coil spring 136, which is the same physical element.

[0029] A weight damper 137 and a plunger damper 138 are also provided inside the body 119. The weight damper 137 is disposed between the top cover 129 and the counterweight 118. The plunger damper 138 is disposed between the bottom holder 130 and the plunger 126. The weight damper 137 and the plunger damper 138 are both made of synthetic rubber.

[0030] In the driving tool 100, the movement of the striker 112a, the plunger 126, or the counterweight 118 in the third direction D3 is referred to as a downward movement. The movement of the striker 112a or the counterweight 118 in the fourth direction D4 is referred to as an upward movement. The striker 112a and the counterweight 118 can each reciprocate in the direction of the center line E1.

[0031] The battery pack 117 in the driving machine 100 can be attached to and detached from the mounting part 122. The battery pack 117 is a DC power source, and the power of the battery pack 117 can be supplied to the electric motor 114. In other words, the electric motor 114 is driven by the power of the battery pack 117. The mounting part 122 also includes a control part 116 of the driving machine 100.

[0032] The driving tool 100 has a trigger 142 and a trigger switch 143 provided on the handle 120, and when the operator applies an operating force to the trigger 142, the trigger switch 143 turns on. When the operator releases the operating force applied to the trigger 142, the trigger switch 143 turns off.

[0033] The electric motor 114 has a rotor and a stator (not shown), and a motor shaft 146 is attached to the rotor. When electric motor 114 receives power from a battery pack 117, the motor shaft 146 rotates. A reducer (not shown) disposed in the motor case 121 has multiple sets of planetary gear mechanisms, an input element 148, and an output element 149. The input element 148 is connected to the motor shaft 146.

[0034] The transmission mechanism 115 converts the rotational force of the output element 149 into an operating force of the striking portion 112 and an operating force of the counterweight 118. The transmission mechanism 115 has a first gear 150, a second gear 151, and a third gear 152.

[0035] As shown in FIGS. 3(a) and 3(b), 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 is rotatable relative to the first gear 150. The two cam rollers 158 and 202 are arranged on the same circumference. The two cam rollers 158 and 202 are each rotatable relative to the second gear 151. The two cam rollers 159 and 203 are each rotatable relative to the third gear 152.

[0036] Next, an example of how to use the driving tool 100 shown in Figures 1 and 2 will be described with reference to Figures 3 to 5. Figure 3 shows the state of the transmission mechanism when the driving tool 100 is in maintenance mode, Figure 4 shows the state of the transmission mechanism during normal standby, and Figure 5 shows the state of the transmission mechanism at the top dead center position.

[0037] The driving tool 100 has an operation mode called a maintenance mode. In the maintenance mode, as shown in Figures 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 counterweight 118 is positioned near the end of the guide shaft 128 in the fourth direction D4 shown in Figure 1.

[0038] 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 on, the controller supplies power to the electric motor 114, causing the motor shaft 146 to rotate forward. The rotational force of the motor shaft 146 is amplified by a reducer (not shown) and transmitted to the first gear 150, causing the first gear 150 to rotate counterclockwise.

[0039] 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 with 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. In other words, the striking portion 112 rises. Also, as shown in FIGS. 4(a) and (b), when the third gear 152 rotates counterclockwise and the cam roller 159 engages with the weight arm portion 135, the counterweight 118 operates in the third direction D3. In other words, the counterweight 118 descends.

[0040] During rotation of first gear 150 and second gear 151, when cam roller 157 is engaged with first arm 167, one cam roller 158 engages with second arm 160 (engagement portion 126c). Thereafter, cam roller 157 is released from first arm 167. Furthermore, when one cam roller 158 is engaged with second arm 160 (engagement portion 126c), as shown in FIGS. 4(a) and 4(b), another cam roller 202 engages with second arm 160 (engagement portion 126c). Next, cam roller 158 that was previously engaged with second arm 160 (engagement portion 126c) is released from second arm 160 (engagement portion 126c).

[0041] Then, as the counterweight 118 descends, the plunger 126 ascends. Next, the counterweight 118 reaches its bottom dead center, and the plunger 126 ascends further. Then, as shown in FIGS. 5(a) and 5(b), the plunger 126 reaches its top dead center. This causes the energy of the coil spring 136 to be stored to its maximum. After that, both cam rollers 158, 202 are released from the second arm 160 (engagement portion 126c), and the coil spring 136 is also released accordingly. With the coil spring 136 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.

[0042] When the plunger 126 descends, that is, when the striking portion 112 descends, the driver blade 127 strikes the fastener 125 located in the injection path 124 shown in FIG. 2. The fastener 125 is driven into the workpiece W1. After the driver blade 127 strikes the fastener 125, the plunger 126 collides with the plunger damper 138. The plunger damper 138 absorbs part of the kinetic energy of the striking portion 112. The counterweight 118 also collides with the weight damper 137. The weight damper 137 absorbs part of the kinetic energy of the counterweight 118.

[0043] 1 to strike the stopper 125, the counterweight 118 also acts in a fourth direction D4 opposite to the third direction D3, thereby reducing the recoil generated when the striking portion 112 strikes the stopper 125.

[0044] As shown in FIG. 2, a top cover 129 that houses a weight damper 137 that absorbs part of the kinetic energy of the counterweight 118 is attached to the lid member 111b.

[0045] Next, the connection structure between the bottom holder 130 and the top cover 129 in the driving tool 100 will be described. As shown in FIG. 2, the bottom holder 130 and the 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, when the coil spring 136 is extended, receive the biasing force of the coil spring 136 and restrict the amount of extension of the coil spring 136, with the bottom holder 130 being the lower restricting portion and the top cover 129 being the upper restricting portion. The guide bar 131 is located on both sides of the coil spring 136 in the second direction D2 and is a connecting portion that connects the top cover 129 and the bottom holder 130. The guide bar 131 abuts against the side of the plunger 126 (striking portion 112) and guides the movement of the plunger 126 in the first direction D1 (up and down direction). That is, the guide bar 131 also serves as a long, thin rail that guides the vertical movement of the plunger 126. The guide bar 131 is attached to the bottom holder 130 by screws 133.

[0046] Furthermore, a plunger damper (buffer) 138 that buffers the impact when the plunger 126 reaches the bottom dead center is provided inside the case member 111a. The plunger damper 138 is disposed between the bottom holder 130 and the plunger 126 in the first direction D1 (vertical direction). As a result, when the plunger 126 reaches the bottom dead center and collides with the plunger damper 138, the plunger damper 138 collapses, thereby buffering the impact from the plunger 126.

[0047] The guide bar 131 of the driving tool 100 has a notch (avoidance portion) 132 that avoids contact with the plunger damper 138 in a portion that overlaps with the plunger damper 138 in the first direction D1 (vertical direction). As shown in Figures 6 and 7, the guide bar 131 has a first portion 131a located in a portion that overlaps with the plunger damper 138 shown in Figure 2 in the first direction D1 (vertical direction), and a second portion 131b located in a portion that does not overlap with the plunger damper 138 in the first direction D1. In other words, the guide bar 131 has the first portion 131a and the second portion 131b, and the first portion 131a overlaps with the plunger damper 138, while the second portion 131b does not overlap with the plunger damper 138. As shown in FIGS. 6(b) and 7(a), the guide bar 131 is formed with a plurality of through holes 131e for fastening screws.

[0048] 2 in a second direction D2 (left-right direction) intersecting the first direction D1 (up-down direction), and a notch 132 is provided in a first portion 131a of the standing wall portion 131c as an avoidance portion for avoiding contact with the plunger damper 138, as shown in FIGS. 6(a) and 7(b). That is, the notch 132 is a portion recessed from an upper end portion 131d of the notch 132 and is also a portion recessed in a direction away from the plunger damper 138. The notch 132 is provided in the first portion 131a of the standing wall portion 131c but not in the second portion 131b.

[0049] Next, the structure of the bottom holder 130 will be described with reference to Figures 8 and 9. The bottom holder 130 includes a substantially circular damper mounting portion 130c on which the plunger damper 138 shown in Figure 2 is disposed, a protruding support portion 130a that supports the plunger damper 138, and a connecting portion 130b that is connected to the guide bar 131. As shown in Figures 8(b) and 9(b), the two connecting portions 130b are provided at positions facing each other on the outer periphery of the damper mounting portion 130c, and the guide bar 131 is fixed to each connecting portion 130b with a screw.

[0050] 8(a) and 9(a), two support portions 130a are provided on the outer periphery 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 is crushed by an impact from the plunger 126. 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 crushed plunger damper 138 comes into contact with them.

[0051] Next, the structure of the plunger 126 will be described with reference to Figures 10 and 11. The plunger 126 moves in a first direction D1 (vertical direction) along a guide shaft 128 shown in Figure 2 and includes a plunger shaft 126a into which the guide shaft 128 is inserted, a spring holding portion 126i that holds a coil spring 136 shown in Figure 2, and an abutment surface 126h that is located on the opposite side of the spring holding portion 126i and comes into contact with the plunger damper 138. The plunger 126 also includes two side engaging portions 126b that are provided on the outer periphery of the spring holding portion 126i and are positioned opposite to each other, and an engaging portion 126c that is provided on the outer periphery of the spring holding portion 126i and engages with a cam roller 202 shown in Figure 4. Furthermore, plunger 126 is provided with protrusion 126d that is provided on the outer periphery of spring holding portion 126i and engages with cam roller 157 shown in Fig. 3, and blade holding portion 126g that is provided on the outer periphery of spring holding portion 126i and holds driver blade 127 shown in Fig. 3. Protrusion 126d is provided to protrude below spring holding portion 126i of plunger 126.

[0052] 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 its rotation in the circumferential direction is also restricted by the guide bar 131. Specifically, the movement of the side engaging portion 126b of the plunger 126 in the first direction D1 (vertical direction) is guided by the standing wall portion 131c of the guide bar 131 shown in Fig. 6, and its rotation in the circumferential direction is also restricted by the standing wall portion 131c.

[0053] Further, a right rib 126j, a left rib 126k, and a rear rib 126l are provided on the outer periphery of the spring holding portion 126i of the plunger 126, standing from the spring holding portion 126i in the first direction D1 (vertical direction). The right rib 126j and the left rib 126k are provided between each of the two side engaging portions 126b and the blade holding portion 126g in the circumferential direction centered on the plunger shaft 126a so as to sandwich the blade holding portion 126g, and the rear rib 126l including the second arm 160 (engaging portion 126c) is provided. In other words, the right rib 126j, the side engaging portion 126b, the rear rib 126l, the side engaging portion 126b, and the left rib 126k are provided in succession in this order from the blade holding portion 126g in the circumferential direction centered on the plunger shaft 126a, surrounding the entire outer periphery of the spring holding portion 126i. Furthermore, an inclined rib 126m is provided to bridge between the second arm 160 (the engaging 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 (the vertical direction) so as to connect the upper end of the second arm 160 (the engaging portion 126c) and the upper surface of the spring holding portion 126i. With the above configuration, damage to the plunger 126 due to an impact during operation can be suppressed. In the plunger 126, 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. Therefore, there is a risk that the spring holding portion 126i may bend in the vertical direction and be damaged due to an impact during operation. However, the spring holding portion 126i is reinforced by the right rib 126j, the left rib 126k, the rear rib 126l, and the inclined rib 126m, which suppresses damage.

[0054] Due to the respective structures of the guide bar 131, bottom holder 130, and plunger 126 described above, the positional relationship between the guide bar 131, bottom holder 130, plunger 126, and plunger damper 138 is as shown in Fig. 12. That is, the plunger 126, plunger damper 138, and bottom holder 130 are disposed between two guide bars 131 disposed opposite each other, and the plunger damper 138 is disposed between the plunger 126 and bottom holder 130 in the first direction D1 (vertical direction).

[0055] 13 shows the state immediately before plunger 126 reaches bottom dead center and before plunger damper 138 is crushed, and FIG. 14 shows the state after plunger 126 reaches bottom dead center and plunger damper 138 is crushed. In driving tool 100 of this embodiment, notch 132 is provided in upright wall portion 131c of first portion 131a of guide bar 131 shown in FIG. 6. Therefore, first portion 131a of guide bar 131 is farther away from plunger damper 138 than second portion 131b of guide bar 131. 13(b), in the upright wall portion 131c of the guide bar 131, a notch position P2 of the upright wall portion 131c is farther from the plunger damper 138 than an upper end position P1 of the upright wall portion 131c, and a distance L2 in the left-right direction between the notch position P2 and the plunger damper 138 is greater than a distance L1 in the left-right direction between the upper end position P1 and the plunger damper 138. That is, the position of the bottom 132a of the notch portion 132 (notch position P2) shown in FIG. 6 is farther from the plunger damper 138 than the upper end position P1 of the upright wall portion 131c. In other words, the planar shape of the plunger damper 138 is circular. The position of the bottom 132a of the notch 132 of the guide bar 131 (notch position P2) is located farther from the outer periphery of the circular plunger damper 138 than the upper end position P1 of the standing wall portion 131c. In other words, the position of the bottom 132a of the notch 132 (notch position P2) is located farther from the center C1 of the circular plunger damper 138 than the upper end position P1 of the standing wall portion 131c. In other words, 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 portion 131c.

[0056] As a result, as shown in FIG. 14 , even if the plunger 126 reaches the bottom dead center and applies an impact to the plunger damper 138, causing the plunger damper 138 to collapse, the outer periphery of the plunger damper 138 does not come into contact with the notch 132 provided in the vertical wall portion 131c of the first portion 131a of the guide bar 131. As a result, damage to the plunger damper 138 is suppressed. Furthermore, since the distance from the outer periphery 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 outer periphery of the plunger damper 138 to the upper end position P1 of the vertical wall portion 131c, the planar shape of the plunger damper 138 can be enlarged. This reduces vibration of the driving tool body, thereby improving the performance of the driving tool 100. Furthermore, the increased size of the plunger damper 138 contributes to maintaining the durability of the driving tool 100. In other words, the performance of the driving tool 100 can be improved while maintaining its durability.

[0057] Furthermore, by providing the cutout portion 132 in the upright wall portion 131c of the guide bar 131, it is possible to increase the size of the plunger damper 138 without increasing the installation distance between the two opposing guide bars 131. This makes it possible to improve the performance of the driving tool 100 while suppressing increases in size and cost of the driving tool 100.

[0058] Furthermore, the notch 132 of the guide bar 131 is provided in the first portion 131a of the upright wall portion 131c, but not in the second portion 131b. As shown in FIG. 6, the length of the first portion 131a of the guide bar 131 is much shorter than the length of the second portion 131b. Because the impact of the plunger 126 colliding with the plunger damper 138 is also applied to the guide bar 131, it is preferable that the guide bar 131 have high rigidity. In other words, by making the length of the first portion 131a much shorter than the length of the second portion 131b, it is possible to minimize a decrease in the rigidity of the guide bar 131. Furthermore, because the notch 132 is not provided in the second portion 131b, it is possible to ensure the function of the guide bar 131 of restricting the rotation of the plunger 126 in the circumferential direction.

[0059] As shown in FIG. 6 , in guide bar 131, upper end 131d of upright wall 131c and bottom 132a of notch 132 are connected by inclined portion 132b, which gradually moves away from plunger damper 138 from upper end 131d toward bottom 132a. That is, in notch 132 of upright wall 131c, upper end 131d and bottom 132a are connected by inclined portion 132b, which is inclined relative to upper end 131d or bottom 132a. In other words, the change in cross-sectional area of notch 132 can be made gentle. This can reduce stress concentration at notch 132 when an impact from plunger 126 propagates to guide bar 131. As a result, damage to guide bar 131 can be reduced.

[0060] 10(b), the protrusion 126d of the plunger 126 is provided with an arc-shaped notch 126e centered on the center C1 of the plunger damper 138. The notch 126e is a relief portion that prevents the outer periphery of the plunger damper 138 from interfering with the protrusion 126d when the plunger damper 138 is crushed by the impact of the plunger 126. As shown in FIG. 3(b), the protrusion 126d is a member that engages with the cam roller 157 to lift the plunger 126 against the biasing force of the coil spring 136 when the plunger 126 is lifted. Therefore, the protrusion 126d also needs to have high rigidity. Therefore, by providing an arc-shaped notch 126e in the protrusion 126d centered on the center C1 of the plunger damper 138, it is possible to minimize the volume of the portion of the protrusion 126d that is to be scraped off, while preventing the outer periphery of the plunger damper 138 from coming into contact with the protrusion 126d and damaging the plunger damper 138.

[0061] Next, a modification of this embodiment will be described.

[0062] In the first modified example shown in FIGS. 15 and 16, the guide bar 131 is a plate-shaped member that does not have the upright wall portion 131c shown in FIG. 6. In the structure shown in FIG. 15, a first portion 131a of the guide bar 131 is provided with an avoidance portion that avoids interference with the plunger damper 138. The avoidance portion in the structure shown in 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. This allows the stepped portion 131f of the guide bar 131 to be spaced apart from the plunger damper 138, as shown in FIG. 16(b). Note that the guide bar 131 is formed with a slit 131g, as shown in FIG. 16(a). The engaging portion 126f of the plunger 126 engages with the slit 131g, allowing the plunger 126 to move in the first direction D1 while being guided by the guide bar 131. As described above, in the first modified example, interference between plunger damper 138 and guide bar 131 can be suppressed, thereby preventing damage to plunger damper 138. Furthermore, it is possible to increase the size of plunger damper 138, thereby improving the performance of the driving tool.

[0063] 17 and 18, the guide bar 131 is also a plate-shaped member, and does not have the standing wall portion 131c shown in FIG. 6. In the structure shown in FIG. 17, a avoidance portion is provided in the first portion 131a of the guide bar 131 to avoid interference with the plunger damper 138. 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 a result, as shown in FIG. 18(b), by providing the through hole 131h in the first portion 131a of the guide bar 131, interference between the guide bar 131 and the plunger damper 138 can be suppressed. 18(a), a slit 131g is formed in the guide bar 131, and when the engaging portion 126f of the plunger 126 engages with this slit 131g, the plunger 126 is guided by the guide bar 131 and moves in the first direction D1. As described above, in the second modified example, interference between the plunger damper 138 and the guide bar 131 can be suppressed, and therefore damage to the plunger damper 138 can be suppressed. Furthermore, the plunger damper 138 can be made larger, improving the performance of the driving tool.

[0064] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, in the above-described embodiment, the avoidance portion is provided in the first portion 131a of the guide bar 131. However, the avoidance portion may be provided not only in the first portion 131a but also in the second portion 131b of the guide bar 131. [Explanation of symbols]

[0065] 100...driving machine (work machine), 111...housing, 111a...case member, 111b...lid member, 111c...first case member, 111d...second case member, 111e...opening, 112...striking portion, 112a...striker, 113...magazine, 114...electric motor (motor), 115...transmission mechanism, 116...control portion, 117...battery pack, 118...counterweight, 119...body portion, 120...handle, 121...motor case, 122...mounting portion, 123...ejection portion, 124...ejection path, 125...fastener, 126...plunger, 126a...plunger shaft, 126b...side engaging portion, 126c...engaging portion, 126d...projection portion, 126e...notch portion, 126f...engaging portion, 126g...blade holding portion, 126h...butting surface, 126i...spring holding portion, 126j...right side rib, 126k...left side rib, 126l...rear side rib, 126m...inclined rib, 127...driver blade, 128...guide shaft, 129...top cover (upper restricting portion), 130...bottom holder (lower restricting portion), 130a...support portion, 1 30b...connection portion, 130c...damper mounting portion, 131...guide bar (guide portion, connecting portion), 131a...first portion, 131b...second portion, 131c...standing wall portion, 131d...upper end portion, 131e...through hole, 131f...step portion (avoidance portion), 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 portion), 1 42...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...Upper end position, P2...Notch position, W1...Workpiece to be driven

Claims

1. A motor; A coil spring that extends vertically, a striking portion that moves upward while compressing the coil spring when the driving force of the motor is transmitted, and moves downward by the biasing force of the coil spring when the driving force of the motor is cut off, and strikes the stopper; a guide portion that contacts a side surface of the hitting portion and guides the movement of the hitting portion in the up and down direction; a buffering section that buffers the impact when the striking section reaches the bottom dead center; and the guide portion has an avoidance portion that avoids contact with the buffer portion in a range that overlaps with the buffer portion in the up-down direction, the guide portion is arranged next to the buffer portion in the left-right direction, and has a first portion located in a range overlapping with the buffer portion in the up-down direction, and a second portion located in a range not overlapping with the buffer portion in the up-down direction, the first portion forms the avoidance portion by making the left-right distance between an end of the first portion on the buffer portion side in the left-right direction and an end of the buffer portion on the guide portion side in the left-right direction larger than the left-right distance between an end of the second portion on the buffer portion side in the left-right direction and an end of the buffer portion on the guide portion side in the left-right direction, When the impact portion reaches the bottom dead center, the buffer portion does not come into contact with the guide portion over the entire circumferential direction about a center line that passes through the buffer portion in the up-down direction, The work machine further includes a shaft portion fixed to the guide portion and passing through the buffer portion in the up-down direction.

2. an upper regulating portion and a lower regulating portion that, when the coil spring is extended, receive the biasing force of the coil spring and regulate the extension amount of the coil spring; the guide portion is a connecting portion located to 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 disposed between the lower restricting portion and the striking portion in the up-down direction.

3. the connecting portion includes a standing wall portion that stands in the left-right direction toward the buffer portion, The work machine according to claim 2 , wherein the first portion of the standing wall portion is provided with a notch as the avoidance portion.

4. The work machine according to claim 3 , wherein the upper end of the standing wall portion and the bottom of the notch portion are connected by an inclined portion that gradually moves away from the buffer portion from the upper end toward the bottom.

5. a gear portion to which the driving force of the motor is transmitted, and a cam roller provided in the gear portion, the impact portion includes a protrusion that protrudes downward from the impact portion so as to be positioned in a range that overlaps with the buffer portion in the up-down direction when the impact portion is positioned at the bottom dead center, and that engages with the cam roller to move the impact portion upward; The buffer portion has a circular planar shape, 5. The work machine according to claim 1, wherein the protrusion has an arc-shaped notch centered on the center of the buffer portion, the arc-shaped notch being positioned in a range that overlaps with the buffer portion in the vertical direction and that is arranged so as not to interfere with the buffer portion when the buffer portion is crushed by the impact of the striking portion.

Images