WORK MACHINE

Abstract

The durability of a working machine is improved. A driving device includes an electric motor, a striking unit (112) configured to strike a fastener by moving towards a lower side in an up-down direction (D1), a clamping unit configured to clamp the striking unit (112) towards the lower side in the up-down direction (D1), and a rotating unit configured to move the striking unit (112) towards an upper side in the up-down direction (D1), and comprising a first gear (151), a second gear (152), and a third gear (153).The rotary unit includes a wheel (150) and several engagement areas designed to engage with the striking unit (112), and the several engagement areas include a second pin (152)a and a third pin (152b) that engage with the striking unit (112) when the striking unit (112) is moved upwards in the up-down direction (D1), and a stop pin (152c) that does not engage with the striking unit (112) when the striking unit (112) is moved upwards in the up-down direction (D1).

Description

TECHNICAL FIELD

[0001] The present invention relates to a working machine, such as a driving device. STATE OF THE ART

[0002] As an example of a working machine, a driving device is known which has a motor, an impact unit capable of striking a fastener, and a rotating unit which is rotated by a driving force of the motor.

[0003] As such a driving device described above, for example, Patent Document 1 describes a driving device having a structure in which a pin wheel is provided as a constituent part of a rotating unit, a plunger is provided as a striking unit, and the plunger is clamped by engaging a pin provided on the pin wheel with the plunger.

[0004] Patent Document 1: Japanese Patent Application Disclosure: JP 2020-19 078 A BRIEF DESCRIPTION OF THE INVENTION Problems to be solved with the invention

[0005] The driving device described in the aforementioned patent document 1 suffers from the problem of idle stroke, in which the plunger unintentionally moves to bottom dead center because the pin provided on the pin wheel breaks or the like. Since the occurrence of idle stroke can lead to plunger breakage, an improvement in the durability of the driving device was desired.

[0006] One objective of the present invention is to provide a working machine with improved durability. Means to solve the problems

[0007] A work machine according to the present invention includes: a drive source; an impact unit configured to strike a fastener by moving to one side in a first direction; a clamping unit configured to clamp the impact unit to the one side in the first direction;and a rotary unit configured to be rotated by a driving force from the drive source, thereby moving the striking unit to the other side in the first direction, the rotary unit comprising a base unit and a plurality of engagement areas provided on the base unit to engage with the striking unit, and the plurality of engagement areas comprising: a first engagement area that engages with the striking unit when the striking unit is moved to the other side in the first direction; and a second engagement area that does not engage with the striking unit when the striking unit is moved to the other side in the first direction. Effect of the invention

[0008] The present invention can improve the durability of a work machine. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a side cross-sectional view showing the structure of a working machine according to an embodiment of the present invention; Fig. 2(a) and Fig. 2(b) are a left side view and a right side view, each showing the construction of a clamping mechanism of the in Fig. 1. Show the working machine shown; Fig. 3(a) and Fig. 3(b) are a front and a rear view, each showing the structure of the in Fig. The clamping mechanism shown in section 2 is shown; Fig. 4 is a cross-sectional view showing the structure of the Fig. 1 shows the working machine along line AA; Fig. 5(a), Fig. 5(b) and Fig. 5(c) are a side view, a front view and a perspective view, each showing a meshing structure of gears in the Fig. The clamping mechanism shown in section 2 is shown; Fig. 6(a), Fig. 6(b) and Fig. 6(c) are a rear view, a right side view and a front view, each showing a state of the in Fig. 2. The clamping mechanism shown is in a bottom dead center position; Fig. 7(a), Fig. 7(b) and Fig. 7(c) are a rear view, a right side view and a front view, each showing a state of the in Fig. 2. Show the clamping mechanism shown at the time of clamping; Fig. 8(a), Fig. 8(b) and Fig. 8(c) are a rear view, a right side view and a front view, each showing a state of the in Fig. 2. Show the clamping mechanism shown at the time of clamping; Fig. 9(a), Fig. 9(b) and Fig. 9(c) are a rear view, a right side view and a front view, each showing a state of a striking unit in a ready position in the Fig. The clamping mechanism shown in section 2 is shown; Fig. 10(a), Fig. 10(b) and Fig. 10(c) are a rear view, a right side view and a front view, each showing a state of the in Fig. 2. The clamping mechanism shown is in a top dead center position; Fig. 11(a), Fig. 11(b) and Fig. 11(c) are a rear view, a right side view and a front view, each showing a state in which a plunger is supported by a second engagement area when the plunger is removed from the in Fig. 9 shown state; Fig. 12(a), Fig. 12(b) and Fig. 12(c) are a rear view, a right side view and a front view, each showing a state in which the plunger is protruded by a second projecting area in which Fig. The clamping mechanism shown in section 2 is pushed upwards; Fig. 13(a), Fig. 13(b) and Fig. 13(c) are a rear view, a right side view and a front view, each showing a state in which the plunger is supported by the second engagement area when the plunger is removed from the Fig. The state shown in 12 is lowered; Fig. 14 is a schematic view showing the projections of the racks of the tappet and the pins of the gear in the Fig. The clamping mechanism shown in section 2 is shown; Fig. 15 is a schematic view showing a positional relationship between the racks of the plunger and the pins of the gear in the first direction in the standby position of the Fig. The clamping mechanism shown in section 2 is shown, and Fig. 16(a) and Fig. 16(b) are a front view and a perspective view each showing a structure of a pin wheel according to an embodiment of the present invention. DESCRIPTION OF THE EMBODIMENTS

[0009] Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

[0010] In the present embodiment, a working machine in the form of a coil spring driving device is described as an example. Fig. 1 to Fig. The driving device 100 shown in Figure 4 includes a housing 111, a striking unit 112, a magazine 113, an electric motor (drive source) 114, a transmission mechanism (tensioning 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 housing 121 connected to the body 119. An attachment unit 122 is connected to the handle 120 and the motor housing 121. The battery pack 117 is attached to the attachment unit 122. Furthermore, a driving unit 123 having a driving path 124 is provided at the tip of the body 119. The driving unit 123 carries a fastening element 125, which is struck by the striking unit 112. The driving unit 123 is attached to the body 119, and a worker can grasp the handle 120 by hand and press the tip of the driving unit 123 onto a workpiece W1.

[0011] The motor housing 121 is arranged between the handle 120 and the magazine 113 in the direction of a center line E1. The magazine 113 is a unit in which a plurality of fasteners 125 are stored. A fastener 125 consists of a nail and has the shape of a rod. The magazine 113 contains a feed device that supplies the fasteners 125 stored in the magazine 113 to the driving path 124.

[0012] The striking unit 112 is an element that extends over the inner and outer surfaces of the body 119 and is capable of striking the fastener 125 by moving it to one side (underside) in an up-and-down direction (first direction) D1. The striking unit 112 includes, in particular, a plunger 126 arranged in the body 119 and a driving blade 127 attached to the plunger 126. The driving blade 127 is an element for driving the fastener 125 and is made of metal. The plunger 126, to which the driving blade 127 is attached, is made of metal or a synthetic resin.

[0013] In body 119 there is a Fig. 4 is provided. The center line E1 passes through the center of the guide shaft 128. The guide shaft 128 is attached to an upper cover 129 and a lower holder 130.

[0014] As in Fig. 1, the driving device 100, as described above, includes the electric motor 114, the impact element 112, which is driven by the driving force of the electric motor 114, impacts the fastener 125, and reciprocates in the up-down direction D1, and the housing 111 in which the electric motor 114 and the impact element 112 are housed. The up-down direction D1 includes an impact direction D2 in which the impact unit 112 impacts the fastener 125, and a return direction D3 opposite to the impact direction D2. When the striking unit 112 strikes the fastening element 125, the striking unit 112 moves in the up-down direction D1 to one side (underside), and when the striking unit 112 returns, the striking unit 112 moves in the up-down direction D1 to the other side (topside).

[0015] Furthermore, the body 119 contains a spring (tensioning unit) 136, which can expand and contract in the up-down direction D1 and tensions the striking unit 112 in the up-down direction D1 to one side (underside), as well as the plunger 126, which abuts the end region of the spring 136 in the up-down direction D2 and can strike the fastening element 125. Specifically, the plunger 126, the spring 136, the guide shaft 128, and the counterweight 118, which rests against the end region of the spring 136 in the return direction D3, are housed in the body 119 of the casing 111. In addition, the transmission mechanism 115 is provided in the body 119, which is driven by the driving force of the electric motor 114, biases the plunger 126 toward the end portion of the spring 136 in the return direction D3, and biases the counterweight 118 toward the end portion of the spring 136 in the impact direction D2 to compress the spring 136.The transmission mechanism 115 here includes, for example, a first gear 151, a second gear 152 and a third gear 153, as shown in . Fig. 2 and Fig. Figure 3 shows that the first gear 151, the second gear 152, and the third gear 153 are each fitted with a pin and form a rotary unit, also known as a pin-wheel assembly. The rotary unit includes a wheel 150, which serves as the base unit, and a multitude of engagement areas on the wheel 150 that can be engaged with the striking unit 112. The first gear 151, the second gear 152, and the third gear 153 are rotated by the driving force of the electric motor 114 to move the striking unit 112 in the up-down direction D1 to the other side (top). The transmission mechanism 115 is supported on both sides by a guide rod 131. In other words, the movement of the striking unit 112 is guided by the guide rod 131. As shown in Figure 3, the movement of the striking unit 112 is guided by the guide rod 131. Fig. 2, a lock 132, which restricts the movement of the counterweight 118, is rotatably mounted on the guide rod 131. It should be noted that a weight buffer 137, against which the counterweight 118, released from the clamping force of the transmission mechanism 115, can rest, and a plunger buffer 138, against which the plunger 126 can rest, are provided in the body 119, as shown in Fig. 4 shown.

[0016] The function and operation of the individual elements in connection with the insertion of the fastening element 125 into the driving device 100 are described in detail below.

[0017] As in Fig. 4, the plunger 126 is fixed to the outer peripheral surface of the guide shaft 128 and can be moved in the direction of the center line E1 along the guide shaft 128. The guide shaft 128 positions the plunger 126 in the radial direction around the center line E1. Fig. The driving blade 127 shown in Figure 3 can be actuated together with the plunger 126 parallel to the center line E1. The driving blade 127 is in the Fig. 1 shown driving path 124 can be actuated.

[0018] The counterweight 118 is an element that suppresses the recoil absorbed by the housing 111 and is attached to the guide shaft 128. The counterweight 118 can be moved along the guide shaft 128 in the direction of the centerline E1. The guide shaft 128 positions the counterweight 118 in the radial direction around the centerline E1.

[0019] Furthermore, the spring 136 is provided in the body 119 as described above, and the spring 136 is arranged between the plunger 126 and the counterweight 118 in the direction of the center line E1. For example, a compression spring in which a metal wire is wound helically can be used as the spring 136. The spring 136 can expand and contract in the direction of the center line E1. An end region of the spring 136 on the side that is provided with the lower holder 130 in the direction of the center line E1 comes into direct or indirect contact with the plunger 126.

[0020] On the other hand, an end portion of the spring 136 on the side provided with the top cover 129 in the direction of the center line E1 comes into direct or indirect contact with the counterweight 118. The spring 136 receives a compressive force in the direction of the center line E1 and stores elastic energy. Note that the spring 136 is an example of a tensioning mechanism that tensions the impact unit 112 and the counterweight 118.

[0021] The plunger 126 receives a tension force from the spring 136 in the striking direction D2, which approaches the lower holder 130 in the direction of the center line E1. The counterweight 118 receives a tension force from the spring 136 in the return direction D3, which approaches the upper cover 129 in the direction of the center line E1. The striking direction D2 and the return direction D3 are opposite to each other, and the striking direction D2 and the return direction D3 are parallel to the center line E1. The plunger 126 and the counterweight 118 are tensioned by the same element, namely the spring 136.

[0022] Furthermore, as in Fig. As shown in Figure 4, the weight buffer 137 and the plunger buffer 138 are provided in the body 119. The weight buffer 137 is arranged between the upper cover 129 and the counterweight 118. The plunger buffer 138 is arranged between the lower holder 130 and the plunger 126. Both the weight buffer 137 and the plunger buffer 138 are made of synthetic rubber.

[0023] The battery pack 117 in the Fig. The drive-in device 100 shown in Figure 1 can be attached to and removed from the mounting unit 122. The battery pack 117 is a DC power source, and the electrical energy from the battery pack 117 can be supplied to the electric motor 114. That is, the electric motor 114 is driven by the electrical energy from the battery pack 117. Furthermore, the control unit 116 of the drive-in device 100 is housed in the mounting unit 122.

[0024] The driver 100 includes a trigger (operating unit) 142 and a trigger switch 143 on the handle 120. The trigger 142 is operated by the worker. When the worker applies an operating force to the trigger 142, the trigger switch 143 is turned on. When the worker releases the operating force applied to the trigger 142, the trigger switch 143 is turned off.

[0025] The electric motor 114 includes a rotor and a stator (not shown), and a motor shaft 146 is attached to the rotor. When current is supplied from the battery pack 117, the motor shaft 146 of the electric motor 114 rotates. A reduction unit (not shown) housed in the motor casing 121 has several sets of planetary gears, an input element 148, and an output element 149. The input element 148 is connected to the motor shaft 146. The transmission mechanism 115 converts the rotational force of the output element 149 into the actuating force of the impact unit 112 and the actuating force of the counterweight 118.

[0026] The following section describes in detail the structure and function of the transmission mechanism 115, which is provided as a clamping mechanism in the driving device 100. As in Fig. 5(a), Fig. 5(b) and Fig. As shown in Figure 5(c), the transmission mechanism 115 includes the first gear 151, the second gear 152, and the third gear 153. The outer diameter of the first gear 151, the outer diameter of the second gear 152, and the outer diameter of the third gear 153 are identical. The second gear 152 meshes with the first gear 151 and the third gear 153. Thus, when the first gear 151 rotates in direction R1 due to the driving force of the electric motor 114, the second gear 152 rotates in direction R2. And when the second gear 152 rotates in direction R2, the third gear 153 rotates in direction R3.

[0027] Furthermore, the first gear 151 is provided with a first pin 151a, the second gear 152 is provided with a second pin (first engagement portion, second protruding portion) 152a and a third pin (first engagement portion, first protruding portion) 152b, and the third gear 153 is provided with a fourth pin 153a and a fifth pin 153b that can engage with the counterweight 118. These pins are also called cam followers. Note that the second pin 152a and the third pin 152b are different pins, and the third pin 152b is longer (has a greater projection) than the second pin 152a. In addition, the second gear 152 is provided with a pin (second engagement portion) 152c. The pin 152c is a pin with the same shape as the second pin 152a. The pin 152c and the second pin 152a are pins with the same length (protrusion).Furthermore, in the second gear 152, the second pin 152a, the third pin 152b, and the stop pin 152c are arranged on the same circumference. The stop pin 152c is located on the back side of the second pin 152a in the direction of rotation R2 of the second gear 152. Additionally, the stop pin 152c is located between the second pin 152a and the third pin 152b in the direction of rotation R2 of the second gear 152. In the third gear 153, the fourth pin 153a and the fifth pin 153b are also arranged on the same circumference. Each pin is arranged so that it is rotatable with respect to each gear.

[0028] As in Fig. 6 to Fig. As shown in Figure 13, the plunger 126 includes a first rack 126a, which can engage with the first pin 151a of the first gear 151, and a second rack (first engagement area) 126b, which can engage with the second pin 152a of the second gear 152. Furthermore, the plunger 126 also includes a third rack (second engagement area) 126c, which can engage with the third pin 152b of the second gear 152.

[0029] As in Fig. As shown in Figure 14, the second pin 152a and the stop pin 152c are made from pins of the same shape, so that the projections of the second pin 152a and the stop pin 152c from the second gear 152 are of the same size. Since the second pin 152a can engage in the second rack 126b of the plunger 126, the stop pin 152c can also engage in the second rack 126b (part P2). Because both the second pin 152a and the stop pin 152c are short pins, the second pin 152a and the stop pin 152c are not engaged with the first rack 126a and the third rack 126c of the plunger 126 (sections P1 and P3).The pin 152c is arranged such that during the normal clamping process (movement of the striking unit 112 towards the top in the up-down direction D1) of the transmission mechanism 115, it does not engage with the first rack 126a and the third rack 126c, nor does it engage with the second rack 126b at the time of the normal clamping process. In other words, the pin 152c is not engaged with any rack during the normal clamping process, and the normal clamping process is not hindered by the pin 152c.

[0030] As described above, the driving device 100, according to the present embodiment, comprises a plurality of pins (engagement areas) provided on the respective gears of the transmission mechanism 115, the second pin 152a and the third pin 152b, which engage with the striking unit 112 when the striking unit 112 is moved upwards in the up-down direction D1, and the stop pin 152c, which does not engage with the striking unit 112 when the striking unit 112 is moved upwards in the up-down direction D1. Specifically, pin 152c engages the second rack 126b of the plunger 126 when the second pin 152a and the third pin 152b are released from the plunger 126 and the plunger 126 moves downwards in the up-down direction D1.

[0031] This describes a situation in which the pin 152c and the second rack 126b of the plunger 126 are engaged with each other. The plunger 126 is in a ready state with the third pin 152b (ready state shown in Fig. 9) in engagement, in which the trigger 142 is not actuated. That is, the plunger 126 rests on the third pin 152b in the ready position when the trigger 142 is not actuated. At this time, a ready position in which the striking unit 112 is in the ready position is a position between the top dead center and the bottom dead center of the up-down direction D1 of the striking unit 112. If the plunger 126 in this ready position is lowered, for example due to a breakage or the like of the third pin 152b, the stop pin 152c is engaged with the second rack 126b of the plunger 126 to stop the lowering of the plunger 126, as in Fig. 11. Namely, when the plunger 126 is lowered due to a breakage or the like of the third pin 152b in the standby state, the second rack 126b of the plunger 126 and the stopper pin 152c engage with each other, and the second rack 126b of the plunger 126 catches on the stopper pin 152c. In this way, the plunger 126 can be prevented from falling. When the plunger 126 is lowered due to a breakage or the like of the second pin 152a in a state in which the second pin 152a is engaged with the second rack 126b of the plunger 126 to hold the plunger 126 at the time of the clamping operation of the Fig. To push upwards the transmission mechanism 115 shown in Figure 12, the stop pin 152c engages with the second rack 126b of the plunger 126 to stop the plunger 126 from lowering, as shown in Figure 12. Fig. Figure 13 shows that if the plunger 126 is lowered due to a breakage or similar issue of the second pin 152a in a state where the second pin 152a pushes the plunger 126 upwards, the second rack 126b of the plunger 126 engages with the stop pin 152c, and the second rack 126b of the plunger 126 remains engaged with the stop pin 152c. This prevents the plunger 126 from falling.

[0032] Next, the clamping process of the transmission mechanism 115 will be described with reference to Fig. 6 to Fig. 10 and Fig. 12 described.

[0033] The driving device 100 is in a standby state in which the worker does not activate the trigger 142. The in Fig. The state shown in Figure 9 is the ready state. In the ready state, the plunger 126 is in the ready position between top dead center and bottom dead center in the up-down direction D1, and the third rack 126c of the plunger 126 is held by the third pin 152b so that the plunger 126 does not fall. In the ready position, the driving blade 127 is located on the upper side in the up-down direction D1 relative to the fastening element 125, which is held by the Fig. The drive unit 123 shown in Figure 1 is carried in the ready position of the plunger 126 in the present embodiment. In this embodiment, the ready position of the plunger 126 is a position in which the drive blade 127 is located on the top of the fastening element 125 and is set to a high position near top dead center. Furthermore, in the ready position, the second rack 126b of the plunger 126 does not intersect with the second pin 152a in the up-down direction and does intersect with the stop pin 152c in the up-down direction. As shown in Figure 1, the drive unit 126 is carried in the ready position. Fig. As shown in Figure 15, in the ready position, the second rack 126b of the plunger 126, viewed in the up-down direction, does not intersect with the second pin 152a and intersects with the stop pin 152c at a part S1. If the plunger 126 falls down in the ready position due to a breakage or similar issue of the third pin 152b, the stop pin 152c is therefore engaged with the second rack 126b of the plunger 126, thus stopping the lowering of the plunger 126.

[0034] In a case where the worker performs the driving process with the driving device 100 described above, the worker presses the tip of the in Fig. 1 is applied to the workpiece W1, and the controller detects that the trigger switch 143 is switched on, whereupon the controller supplies power to the electric motor 114 to rotate the motor shaft 146 forward. The rotational force of the motor shaft 146 is amplified by the reduction gear (not shown) and transmitted to the first gear 151, and the Fig. The first gear 151 shown in Figure 9 rotates counterclockwise (direction of rotation R1).

[0035] When the first gear 151 rotates counterclockwise, the second gear 152 rotates clockwise (rotation direction R2), and the third gear 153 rotates counterclockwise (rotation direction R3). When the third gear 153 rotates counterclockwise, the plunger 126 moves against the clamping force of the Fig. 1 shown spring 136 in the return direction D3. As shown in Fig. As shown in Figure 10, the plunger 126 rises. At this point, the third pin 152b is engaged in the third rack 126c on the plunger 126 to push the plunger 126 upwards, but the stop pin 152c cannot be engaged in the third rack 126c. As shown in Fig. As shown in Figure 14, the pin 152c cannot engage with the third rack 126c due to its short length.

[0036] If the third gear 153 rotates counterclockwise, the counterweight 118 moves in the direction of impact D2. That is, the counterweight 118 is lowered.

[0037] Then, when the counterweight 118 is lowered, the plunger 126 rises. Subsequently, the counterweight 118 reaches bottom dead center, the plunger 126 continues to rise, and the plunger 126 then reaches top dead center. In this state, the energy of the spring 136 is maximally accumulated.

[0038] When the third rack 126c and the third pin 152b are released after the plunger 126 reaches top dead center, the third rack 126c is released, and the spring 136 is released accordingly. When the spring 136 is released, the plunger 126 is lowered by the biasing force of the spring 136. Then, as the plunger 126 begins to descend, the counterweight 118 begins to rise due to the biasing force of the spring 136.

[0039] When the plunger 126 is lowered, i.e., the striking unit 112 is lowered and the in Fig. When the bottom dead center position shown in section 6 is reached, the driving blade 127 strikes the fastening element 125, which is located in the Fig. The driving path 124 shown in Figure 1 is located. In this way, the fastener 125 is driven into the workpiece W1. After the driving blade 127 strikes the fastener 125, the ram 126 collides with the ram buffer 138. The ram buffer 138 absorbs some of the kinetic energy of the striking unit 112. The counterweight 118 also collides with the weight buffer 137. The weight buffer 137 absorbs some of the kinetic energy of the counterweight 118.

[0040] When the striking unit 112 acts on the fastening element 125 in the direction of impact D2 as described above, the counterweight 118 acts in the return direction D3 in the opposite direction to the direction of impact D2. Therefore, it is possible to reduce the recoil when the striking unit 112 hits the fastening element 125.

[0041] As in Fig. As shown in Figure 7, when the first gear 151 rotates counterclockwise (rotation direction R1) after the impact unit 112 impacts the fastening element 125, the first rack 126a is tensioned by the first pin 151a, and the plunger 126 rises. That is, the plunger 126 moves in the return direction D3. When the second gear 152 continues to rotate clockwise (rotation direction R2) while the plunger 126 rises, the second rack 126b is supported by the second pin 152a, as shown in Figure 7. Fig. 12 shown, and the plunger 126 is then pushed upwards, as in Fig. 8 shown. Then the raised plunger 126 goes into the Fig. The standby position shown in 9 is transferred to the standby state. When the plunger 126 is in a state in which the in Fig. If the second pin 152a shown in Figure 12 pushes the plunger 126 upwards, and falls down due to a break or the like of the second pin 152a, the stopper pin 152c is engaged with the second rack 126b of the plunger 126, thereby stopping the lowering of the plunger 126.

[0042] Since the 152c pen is a short pen, the 152c pen is used in the Fig. 6 to Fig. The clamping process of the ram 126 shown in Figure 10 (movement of the striking unit 112 towards the top in the up-down direction D1) does not engage with the first rack 126a and the third rack 126c, as described above. Furthermore, the pin 152c is positioned such that it does not engage with the second rack 126b during the normal clamping process. Therefore, the pin 152c shown in Figure 10 is not clamped. Fig. 6 to Fig. 10 The clamping process of the plunger 126 shown is not hindered by the pin 152c.

[0043] In the driving device 100 of the present embodiment, the pin 152c is provided with a short length (small projection) on the second gear 152. If the plunger 126 falls into the ready position due to a breakage or similar issue of the third pin 152b, the stop pin 152c is therefore engaged with the second rack 126b of the plunger 126, thus stopping the plunger 126 from lowering. If the plunger 126 falls into a state where the second pin 152a is pushing the plunger upwards due to a breakage or similar issue of the second pin 152a, the stop pin 152c is engaged with the second rack 126b of the plunger 126, thus stopping the plunger 126 from lowering. In this way, the occurrence of idle strokes, in which the tappet 126 accidentally moves to bottom dead center, can be reduced.Since the occurrence of idle stroke can lead to breakage of the plunger 126, the durability of the driving device 100 can be improved by reducing the occurrence of idle stroke.

[0044] Since the lowering of the plunger 126 by the pin 152c can also be stopped when the plunger 126 falls into the ready position, the ready position of the plunger 126 can be set to a high position near top dead center. In this way, the time until the plunger 126 reaches top dead center from the ready position when the worker activates the trigger 142 can be reduced, and the recoil of the driving device 100 can be improved when the worker activates the trigger 142.

[0045] Furthermore, the pin 152c and the second pin 152a are pins that have the same shape and the same length (projection). By attaching the stopper pin 152c to the second gear 152, the gear and the pin can be used together. That is, the components can be used together.

[0046] Next, a modification of the present embodiment will be described.

[0047] Fig.Figure 16 shows the structure of the second gear 152 (gear 150) according to the modification of the present embodiment. An arcuate projecting area 152d is provided as a second engagement area at a location between the second pin 152a and the third pin 152b of the second gear 152. The arcuate projecting area 152d can be formed integrally with the second gear 152. Even when using the second gear 152 with the arcuate projecting area 152d, the durability and responsiveness of the driving device 100 can be improved. Since the arcuate projecting area 152d can be formed integrally with the second gear 152, the number of parts can also be reduced compared to the case where the pin 152c is provided as the second engagement area on the second gear 152.

[0048] If the second pin 152a and the projecting area 152d are designed as an integrated projecting area, the projecting area is used to clamp the plunger 126, so there is a risk of fatigue accumulation and impairment of durability. To ensure sufficient strength when the plunger 126 is dropped, the second pin 152a and the projecting area 152d are expediently designed separately so that they project independently of each other, rather than being designed as an integrated projecting area extending from the second gear 152.

[0049] The present invention is not limited to the embodiment described above, and various modifications within this scope can be made without departing from the core of the present invention. For example, in the embodiment described above, the driving device 100 was described as being in the form of a coil spring, but the driving device 100 could also be a gas spring that lowers the striking unit using compressed air. REFERENCE MARK LIST 100 Driving device (working machine) 111 housings 112 striking units 113 Magazine 114 Electric motor (power source) 115 Transmission mechanism 116 Control unit 117 Battery pack 118 Counterweight 119 bodies 120 handle 121 Engine housing 122 Mounting unit 123 Driving unit 124 Drive-in path 125 Fastening element 126 pestles 126a first rack 126b second rack (first engagement area) 126c third rack (second engagement area) 127 Drive-in blade 128 Guide shaft 129 top cover 130 lower holder 131 Guide rod 132 Locking mechanism 136 Spring (tensioning unit) 137 weight buffers 138 plunger buffers 142 Trigger (control unit) 143 Release switches 146 Motor shaft 148 Input element 149 Starting element 150 wheels (base unit) 151 first gear (rotary unit) 151a first pen 152 second gear (rotary unit) 152a second pin (first engagement area, second protruding area) 152b third pin (first engagement area, first protruding area) 152c Stopper pin (second intervention area) 152d preceding area (second intervention area) 153 third gear (rotary unit) 153a fourth pen 153b fifth pen D1 Up-down direction (first direction) E1 Center line R1, R2, R3 Direction of rotation W1 workpiece QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2020-19 078 A

[0004]

Claims

[1] Work machine which has the following: a power source; an impact unit configured to strike a fastener by moving to one side in a first direction; a tensioning unit configured to tension the impact unit to the one side in the first direction; and a rotating unit configured to be rotated by a driving force of the driving source, thereby moving the striking unit to the other side in the first direction, wherein the rotary unit comprises a base unit and a plurality of engagement portions provided on the base unit so as to be engageable with the impact unit, and wherein the plurality of engagement areas comprises: a first engagement portion that engages with the impact unit when the impact unit is moved to the other side in the first direction; and a second engagement portion that does not engage with the impact unit when the impact unit is moved to the other side in the first direction. [2] The working machine according to claim 1, wherein the second engagement portion is engaged with the impact unit when the first engagement portion and the impact unit are disengaged from each other and the impact unit is moved to one side in the first direction. [3] A work machine according to claim 2, further comprising an operating unit operated by a worker, wherein the first engagement portion has a first protruding portion and a second protruding portion different from the first protruding portion, and wherein the impact unit is engaged with the first projecting portion in a standby state in which the operating unit is not operated. [4] A working machine according to claim 3, wherein a standby position in which the impact unit is arranged in the standby state is located between a top dead center position and a bottom dead center position in the movement of the impact unit in the first direction. [5] The working machine according to claim 4, further comprising a driving unit configured to support the fastener to be struck by the impact unit, the impact unit being disposed on the other side in the first direction relative to the fastener held by the driving unit in the standby position. [6] Working machine according to claim 4 or 5, wherein the impact unit has a first engagement portion engaged with the second projecting portion, and wherein the first engagement region does not overlap with the second projecting region when viewed in the first direction and overlaps with the second engagement region when viewed in the first direction in the standby position. [7] Working machine according to claim 6, wherein the first projecting portion engages with a second engagement portion provided on the impact unit when the impact unit is moved in the first direction to the other side, and wherein the second engagement portion is not engageable with the second engagement portion. [8] A working machine according to any one of claims 3 to 7, wherein the second engagement portion is arranged on a rear side of the second projecting portion in a rotation direction of the rotary unit. [9] A working machine according to any one of claims 3 to 8, wherein the second engaging portion and the second projecting portion are made of members having the same shape.

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