JP7650448B2 - Driving Tools - Google Patents

Description

The present invention relates to a driving tool.

There are currently available driving tools that use electricity to drive fasteners such as nails, tacks, staples, and pins (hereafter referred to as "fasteners"). Driving tools use a driver to drive fasteners supplied from a magazine. If the driver is operated without fasteners being supplied from the magazine, there is a risk that the material being driven will be damaged or that the fact that a fastener has not been driven will go unnoticed. For this reason, there have been proposals for driving tools equipped with a mechanism to prevent the driver from operating when there are no fasteners left in the magazine (see, for example, Patent Documents 1 to 4).

The driving tools described in Patent Documents 1 and 2 detect the position of a pusher that presses nails toward the ejection port in a magazine, and are equipped with an anti-idle mechanism that restricts the movement of a contact arm from an OFF position to an ON position when it detects that the pusher has advanced to a specified position. The contact arm is a safety mechanism for the trigger, and when the contact arm is in the ON position, pulling the trigger drives out a fastener. The contact arm is provided at the tip of the tool so that it can be freely protruded and retracted in the driving direction, and moves to the ON position when the driving tool is pressed against the material to be driven.

The driving tool described in Patent Document 3 is equipped with an anti-idle mechanism that prevents the trigger from being pulled by engaging a part of the pusher or a member pressed by the pusher when the pusher advances. The driving tool described in Patent Document 4 is equipped with an anti-idle mechanism that is provided with a switch that detects the position of the pusher, and when it detects that the pusher has advanced to a predetermined position, does not operate the driver even if the contact arm or trigger is turned on.

JP 2020-66117 A Japanese Patent Application Publication No. 8-141933 Japanese Patent Application Publication No. 7-246574 JP 2013-6237 A

However, in a usage mode known as drag driving, in which the nail is continuously driven while the contact arm is pressed against the material being driven, the contact arm may remain in the ON state and the nail may run out. With the contact locking method described in Patent Documents 1 and 2, the contact arm that is already in the ON position cannot be returned to the OFF position and locked, so there is a problem that the blank drive prevention mechanism of the driving tool does not work when used in drag driving.

The trigger lock method described in Patent Document 3 can activate the blank-strike prevention mechanism even when the contact arm cannot move from the on state, but there is a problem that the layout is very restricted. It is not suitable for handheld nail-driving tools that require compact size. The remaining amount detection switch method described in Patent Document 4 increases manufacturing costs by the amount of parts such as switches. In addition, since the dimensions of the fasteners are small, detection accuracy is required to reliably detect the presence or absence of fasteners. If the detection accuracy cannot be guaranteed, it is possible to activate the blank-strike prevention mechanism when it is detected that there are approximately few nails remaining, even if it is not possible to detect whether there are 0 or 3 fasteners remaining. However, with a nail-driving tool with such a setting, when the magazine is opened to load new nails, the small number of nails remaining in the magazine may fall inside the magazine and get stuck in a place other than the intended loading position without the operator noticing. It is preferable to set the blank-strike prevention to operate after all nails are used up.

The present invention was made in consideration of these problems, and aims to provide a driving tool that can be used in a variety of ways, is small and easy to handle, and can accurately and reliably prevent blank strikes.

A driving tool according to one aspect of the present invention includes a contact arm that is movably mounted on the tool body and that is pressed by a driving member to move from an OFF position to an ON position, a contact switch that detects the position of the contact arm, an engagement member that engages with the contact arm that has moved to the ON position and presses the contact switch, a magazine that can store multiple fasteners, and a pusher that moves according to the remaining amount of fasteners stored in the magazine. When the pusher moves to an empty position where the remaining amount of fasteners is less than a predetermined number, the engagement member and the contact switch do not come into contact even if the contact arm moves to the ON position.

According to this embodiment, blank strikes are prevented not by restricting the movement of the contact arm, but by not coming into contact with the contact switch, making it possible to accommodate various usage patterns such as drag striking. There are fewer layout restrictions compared to a structure that restricts the movement of the trigger. A compact, easy-to-handle striking tool can be constructed. Blank strikes can be prevented accurately and reliably because it is not affected by the detection accuracy of electrical components such as switches.

In the above embodiment, when the pusher moves to an empty position where the number of fasteners remaining is less than a predetermined number, the engaging member may retreat to a position where it does not come into contact with the contact switch.

According to this aspect, the engaging member moves to retract, preventing undesired contact between the engaging member and the contact switch and more reliably preventing blank strikes.

In the above embodiment, the engagement member may engage with the contact portion and press the contact switch when the contact arm is in the on-state position and the pusher is not in the empty position, and may be pressed by the pusher to release the engagement with the contact portion when the pusher moves to the empty position.

According to this embodiment, the engagement state of the engagement member can be switched in conjunction with the movement of the pusher.

In the above aspect, the engagement member may include a first member supported by the magazine and a second member supported by the first member, and the second member may engage with the contact arm and press the contact switch when the contact arm is in the on-state position and the pusher is not in the empty position, and when the pusher moves to the empty position, the first member is pressed by the pusher and rotates in a direction that releases the engagement between the contact arm and the second member, and the second member may be configured to be swingable about the first member as a fulcrum in a direction away from the contact switch when the engagement with the contact arm is released.

According to this embodiment, the movement of the engaging member includes not only the rotation of the first member relative to the magazine, but also the swinging of the second member relative to the first member. Since the engaging member can move more in the direction away from the contact switch, blank firing can be more reliably prevented.

In the above aspect, the portion of the first member that is pressed by the pusher that has moved to the empty position and the portion that supports the second member are located on opposite sides of the support portion, and when the pusher moves to the empty position, the center of rotation of the second member may move in the opposite direction to the pusher.

In this embodiment, movable parts such as the engagement member move in the opposite direction to the movement of the pusher. In conventional contact locking methods, a member that moves in the same direction as the movement of the pusher restricts the movement of the contact arm. The nose section where the contact arm is located has a small space and is subject to significant layout restrictions. With this embodiment, the movable parts move to the opposite side of the nose section, so the space in the nose section is not compressed. A small, easy-to-handle driving tool can be provided.

In the above embodiment, the contact arm has a contact portion that engages with the engaging member, and both the support portion that supports the engaging member and the guide that guides the movement of the contact portion may be provided on the same outer wall member that constitutes the magazine.

In this embodiment, movable parts such as contact parts and engaging members are supported by the same outer wall member. Because it is necessary to detect whether fasteners less than 1 mm wide remain in the magazine, the positional accuracy of the movable parts is important in the strike-free prevention mechanism. When movable parts are arranged across multiple members, the dimensional tolerances of each member accumulate, making it difficult to obtain positional accuracy. However, with this embodiment, such accumulation of tolerances does not occur, so the positional accuracy of the movable parts can be guaranteed.

The present invention provides a driving tool that can be used in a variety of ways, is small and easy to handle, and can accurately and reliably prevent blank strikes.

FIG. 1 is a side view showing a driving tool according to the present embodiment. FIG. 2 is a cross-sectional view showing the driving tool as viewed from the side. FIG. 3 is a perspective view showing the plunger assembly with the coil spring in an expanded state. FIG. 4 is a cross-sectional view showing the plunger assembly with the coil spring in a contracted state. FIG. 5 is a side view showing the internal structure of the driving tool as viewed from the opposite side to that of FIG. FIG. 6 is a partially exploded perspective view of the contact arm shown in FIG. FIG. 7 is a perspective view showing a state in which the contact arm and the like are removed from the magazine shown in FIG. FIG. 8 is a bottom view showing the nose portion as viewed from below with a part cut away. FIG. 9 is a side view showing a state in which the contact arm is waiting in the OFF state position and the contact arm is engaged with the engaging member. FIG. 10 is a side view showing a state in which the contact arm has moved to a position of the ON state and the contact arm and the engaging member are engaged with each other. FIG. 11 is a side view showing a state in which the contact arm is in the on-state position but the engagement between the contact arm and the engagement member is released.

The following describes an embodiment of the present invention with reference to the drawings. The following embodiment is an example for explaining the present invention, and is not intended to limit the present invention to only that embodiment.

[Configuration of driving tool]
Fig. 1 shows a side view of an electric driving tool 10 (however, a partial cross-sectional view of the magazine portion is shown), and Fig. 2 shows a cross-sectional view of the driving tool 10 as seen from the same direction as Fig. 1 (however, the view shows the state after all fasteners F in the magazine 14 have been driven out). This driving tool 10 is an electric nail driver configured to be able to drive nails (an example of "fasteners F") by driving a plunger 32 (shown in Fig. 2) using a motor 20 (shown in Fig. 2).

In this specification, the terms "up and down," "front and back," and "left and right" are based on the position of the driving tool 10 in Figures 1 and 2. The left and right direction of the paper in Figures 1 and 2 is the front and back direction X of the driving tool 10 (the left direction of the paper is the front direction X1 of the driving tool 10, and the right direction of the paper is the rear direction X2 of the driving tool 10), the vertical direction of the paper in Figures 1 and 2 is the left and right direction Y of the driving tool 10, and the up and down direction of the paper in Figures 1 and 2 is the up and down direction Z of the driving tool 10. The downward direction of the paper in Figures 1 and 2 corresponds to the direction in which the fastener F is driven out, so it may be called the driving direction DR1 or the ejection direction DR1, etc., and the opposite upward direction of the paper is the direction away from the ejection port 12A from which the fastener F is driven out, so it may be called the moving away direction DR2.

The driving tool 10 includes a housing 12, a magazine 14 that stores fasteners F to be driven by the driving tool 10, a driver 34 for driving out the fasteners F, a plunger 32 to which the driver 34 is attached, a motor 20 and a gear 22 for moving the plunger 32 from the bottom dead center to the top dead center, a coil spring 36 that applies a driving force for moving the plunger 32 from the top dead center to the bottom dead center, a moving member 38 disposed at the extending end of the coil spring 36, a wire 40 that engages with the plunger 32 and the moving member 38 to link them together, and a pulley 42 around which the wire 40 is hung. The driving tool 10 is further provided with a detachable battery B.

The driving tool 10 includes a housing 12 (hereinafter, the housing 12 and the part fixed to the housing 12 may be referred to as the "tool body") that houses the main components of the driving tool 10, including the plunger 32. The housing 12 includes a grip portion 12B for the operator to hold, a bridge portion 12C that connects the battery mounting portion to which the battery B is attached and the motor 20, and a nose portion 12D for driving out the fastener F. The grip portion 12B and the bridge portion 12C are each formed, for example, in a columnar shape extending in the front-rear direction X so that the operator can easily hold them. The front end of the housing 12 (and the front end of the driving tool 10) includes a nose portion 12D in which an ejection port 12A for ejecting the fastener F downward is formed. A contact arm 12D1 may be attached to the tip of the nose portion 12D. The contact arm 12D1 is provided on the tool body 12 so that it can move forward and backward, and functions as a safety device that allows the fastener F to be ejected only when the contact arm 12D1 is pressed against the object to be driven and the trigger 12E is pressed down. The ejection port 12A described above is formed, for example, at the tip of the contact arm 12D1.

The housing 12 is provided with a trigger 12E. When the user presses the trigger 12E, it establishes electrical continuity between the battery B and the motor 20. The trigger 12E is exposed on the surface of the grip portion 12B facing downward (the direction of ejection DR1 of the fastener F) and is biased downward by a trigger biasing member 12F such as a spring.

Battery B is configured to be removably attached to the rear end of grip portion 12B and bridge portion 12C. Battery B functions as a DC power source that supplies power to drive a motor, etc., and is configured to output a predetermined DC voltage (e.g., 14V to 20V), for example, a lithium-ion battery. By attaching battery B, the driving tool 10 can be carried and used. However, battery B may be configured to be stored within housing 12, or power may be supplied by means other than a battery.

The driving tool 10 includes a magazine 14 attached to the rear of the nose portion 12D. The magazine 14 is configured to be loaded with a plurality of fasteners F (shown in FIG. 1) arranged in parallel and connected to one another with an adhesive. The magazine 14 includes a pusher 14A that urges the fasteners F toward the nose portion 12D. The pusher 14A is urged by a urging member (not shown) so that when the leading fastener F is driven out by the driver 34, the adjacent fasteners F are supplied to the ejection path of the nose portion 12D.

The driving tool 10 further includes a plunger assembly 30. FIG. 3 is a perspective view showing the plunger assembly 30 with the coil spring 36 in an extended state, and FIG. 4 is a cross-sectional view showing the plunger assembly with the coil spring 36 in a contracted state.

As shown in FIG. 4, the plunger assembly 30 includes, for example, a driver 34, a plunger 32, a coil spring 36, a moving member 38, a wire 40, a pulley 42, a cylinder 44 that houses the coil spring 36, and a pair of guide rails 46 that regulate the movement direction of the plunger 32.

The driver 34 is a member that contacts and strikes the fastener F to drive out the fastener F. The driver 34 is composed of, for example, a rigid metal body formed into a long, thin rod extending in the drive direction DR1 of the fastener F. Since the fastener F is disposed on an extension line of the driver 34, when the driver 34 moves in the drive direction DR1, the front end of the driver 34 strikes the fastener F. The rear end of the driver 34 is connected to the plunger 32 and is configured to move integrally with the plunger 32.

The plunger 32 is a member that moves from the top dead center to the bottom dead center, moving together with the driver 34 to drive out the fastener F. The plunger 32 has four side walls, including a first side wall 32A with which the wire 40 engages, a second side wall 32B that is connected to the first side wall 32A at a substantially right angle and engages one of the guide rails 46, a third side wall 32C that is connected to the second side wall 32B at a substantially right angle and arranged substantially parallel to the first side wall 32A, with which the driver 34 engages, and a fourth side wall 32 that is connected to the third side wall 32C and the first side wall 32A at a substantially right angle, arranged substantially parallel to the second side wall 32B, and engages the other guide rail 46. A cylinder 44, which will be described later, is disposed in the hollow area surrounded by the four side walls.

The outer wall surface of the first side wall portion 32A is provided with gear engagement portions 32A1, which are two convex portions provided at different heights. The plunger 32 is configured to move from the bottom dead center to the top dead center against the elastic force (biasing force) of the coil spring 36 by engaging the gear engagement portion 32A1 with a gear 22 (shown in FIG. 2) described later. The top dead center of the plunger 32 is set in the area on the upper end side of the tool body 12, and the bottom dead center is set in the area between the top dead center and the nose portion 12D. Therefore, when the plunger 32 moves from the top dead center to the bottom dead center, the plunger 32 moves in the ejection direction DR1 approaching the injection port 12A, and when the plunger 32 moves from the bottom dead center to the top dead center, the plunger 32 moves in the departure direction DR2 away from the injection port.

A wire engaging portion 32A2 is further provided on the first side wall portion 32A of the plunger 32. The wire engaging portion 32A2 is formed in a hook shape. The wire engaging portion 32A2 has a first portion formed by protruding inward from the inner wall surface of the first side wall portion 32A (i.e., in a direction approaching the third side wall portion 32C), and a second portion extending from the end of the first portion in a direction approaching the top dead center.

The surface of the first part of the wire engaging part 32A2 facing the top dead center becomes a pressure receiving surface for applying a force from the wire 40 to the plunger 32 in the launch direction DR1. In addition, the second part of the wire engaging part 32A2 restricts the wire 40 from shifting in a direction approaching the third side wall part 32C. Furthermore, by forming the first part to protrude in a direction approaching the third side wall part 32C, it is possible to extend the wire 40 that engages with the pressure receiving surface of the first part along the inner wall surface of the first side wall part 32A. Therefore, it is also possible to suppress the wire 40 from shifting in a direction away from the third side wall part 32C. In addition, the wire engaging part 32A2 is formed parallel to a plane that approximates the second side wall part 32B and the fourth side wall part 32D. With this configuration, it is possible to suppress the plunger 32 from tilting due to an imbalance of the force acting on the plunger 32 from the wire 40.

As shown in FIG. 3, the cylinder 44 is a member that houses the coil spring 36 and guides the movement direction of the pin 38A that is part of the moving member 38. The cylinder 44 according to this embodiment includes a cylindrical portion 44A formed in a cylindrical shape and a cap portion 44C that corresponds to a lid for the cylindrical portion 44A. The cylinder 44 penetrates the hollow area surrounded by the four side walls of the plunger 32 and is fixed to the housing 12 (base portion 30A of the plunger assembly 30) so that the movement direction of the plunger 32 and the central axis C of the cylinder 44 are approximately parallel.

As shown in FIG. 4, the inside of the cylinder 44 contains a coil spring 36 made of a compression spring that can expand and contract in the direction (also called the central axis direction or the expansion direction) A of the central axis C of the cylinder 44, i.e., in the movement direction of the plunger 32. One end 36A of the coil spring 36 is fixed to the bottom surface of the cylinder on the injection port side (bottom dead center side of the plunger 32). A moving member 38 is arranged on the other end 36B of the coil spring 36, and tension is applied to the one end 36A side (lower side) of the moving member 38 by a wire 40. Therefore, both the other end 36B of the coil spring and the moving member 38 are configured to be movable, and when the coil spring 36 compresses from an expanded state, the other end 36B of the coil spring 36 and the moving member 38 move in the ejection direction DR1, and when the coil spring 36 expands from a compressed state and restores, the other end 36B of the coil spring and the moving member 38 move in the moving direction DR2 away from the injection port 12A. As shown in FIG. 3, a pair of holes 44B are formed in the wall of the cylinder 44, which extend parallel to the central axis C, i.e., parallel to the expansion and contraction direction A of the coil spring 36.

As shown in FIG. 4, the moving member 38 directly or indirectly engages with a portion of the wire 40, thereby moving the wire 40 together with the expansion and contraction of the coil spring 36 (movement of the other end 36B). The moving member 38 in this embodiment includes a cylindrical portion 38B disposed at the other end 36B of the coil spring, and a pin 38A fixed to the cylindrical portion 38B and with which both ends of the wire 40 are engaged.

As shown in FIG. 4, the wire 40 is a member that is attached to the moving member 38 and the plunger 32 to link the moving member 38 and the plunger 32. In this embodiment, the wire 40 has one end formed in a ring shape, and the pin 38A is inserted into the ring-shaped portion to engage with the pin 38A. The wire 40 that engages with the pin 38A passes through an axial hole in the cylindrical portion 38B of the moving member 38 and extends in the thrust direction DR1 along the central axis C of the coil spring 36, passes through a hole formed in the bottom surface of the cylinder 44, and then changes direction by being wrapped around the pulley 42, extends in the separation direction DR2, and engages with the pressure-receiving surface of the wire engagement portion 32A2 of the plunger 32. The wire 40 then extends in the thrust direction DR1, changes direction by being wrapped around the pulley 42, and extends in the separation direction DR2 along the central axis of the coil spring 36. The other end of the wire 40 is formed into a ring shape, and the wire 40 engages with the pin 38A by inserting the pin 38A through the ring-shaped portion. Therefore, both ends of the wire 40 engage with the pin 38A, and the middle portion of the wire 40 engages with the plunger 32.

That is, the wire 40 includes a first portion 40A including one end that engages with the moving member 38, a second portion 40B that is connected to the first portion 40A and includes a portion extending in the launch direction DR1, a third portion 40C that is connected to the second portion 40B and includes a portion extending approximately in the receding direction DR2, a fourth portion 40D that is connected to the third portion 40C and engages with the plunger 32, a fifth portion 40E that is connected to the fourth portion 40D and includes a portion extending approximately in the launch direction DR1, a sixth portion 40F that is connected to the fifth portion 40E and includes a portion extending in the receding direction DR2, and a seventh portion 40G that is connected to the sixth portion 40F and includes the other end that engages with the moving member 38.

As shown in FIG. 2, the drive mechanism for moving the plunger 32 from the bottom dead center to the top dead center is composed of a motor 20 and a gear 22. The motor 20 according to this embodiment is composed of a three-phase DC brushless motor, and is arranged, for example, in the bridge portion 12C so that the output shaft of the motor 20 is approximately perpendicular to the launch direction DR1 and the separation direction DR2. A gear having the output shaft of the motor 20 as a rotation axis meshes with the first gear 22A constituting the gear 22, and the first gear 22A meshes with the second gear 22B constituting the gear 22. The first gear 22A is arranged in the separation direction DR2 with respect to the gear of the output shaft of the motor 20, and the second gear 22B is arranged in the separation direction DR2 with respect to the first gear 22A. The first gear 22A and the second gear 22B are each provided with a torque roller (not shown) that is parallel to the rotation axis and protrudes in a direction approaching the outer wall surface of the first side wall portion 32A of the plunger 32. The torque roller rotates around the central axis of the first gear 22A (second gear 22B) as the first gear 22A (second gear 22B) rotates. Since the central axis of the first gear 22A (second gear 22B) is parallel to the output shaft of the motor 20, the torque roller reciprocates in the striking direction DR1 and the separating direction DR2 as the first gear 22A (second gear 22B) rotates. When the plunger 32 is near the bottom dead center, the torque roller of the first gear 22A engages with one of the convex portions provided on the bottom dead center side as the gear engaging portion 32A1. Then, the torque roller moves in the separating direction DR2 as the first gear 22A rotates, and the gear engaging portion 32A1 of the plunger 32 is pushed up in the separating direction DR2, so that the plunger 32 can be moved in the separating direction DR2. When the torque roller of the first gear 22A moves to the farthest position in the separation direction DR2, the torque roller of the second gear 22B engages with the other convex portion provided on the top dead center side as the gear engagement portion 32A1. As the second gear 22B rotates, the torque roller moves in the separation direction DR2, pushing the gear engagement portion 32A1 of the plunger 32 further in the separation direction DR2, making it possible to move the plunger 32 further in the separation direction DR2. When the torque roller of the second gear 22B moves to the farthest position in the separation direction DR2, the plunger 32 reaches the top dead center, and the engagement between the gear engagement portion 32A1 and the second gear 22B is released.

In addition, various techniques can be used to move the plunger using a gear or the like driven by a motor, and at the top dead center, disengage the gear or the like from the plunger to move the plunger toward the bottom dead center.

The driving tool 10 further includes a control unit (not shown) for driving the motor 20. The control unit is mounted on a PCB board 24 (shown in FIG. 2) disposed in the gap between the motor 20 and the battery B in the bridge portion 12C. The control unit includes a non-volatile semiconductor memory (e.g., a flash memory) for storing a computer program for executing the arithmetic processing described in this embodiment, such as a control program for the motor 20, a volatile semiconductor memory (SRAM and DRAM) for temporarily storing data such as the results of the arithmetic processing, a microcontroller for executing the computer program read from the semiconductor memory and generating a control command (a PWM signal supplied to the base (or gate) of the inverter circuit), and a driver circuit for generating a drive signal based on the control command. The driver circuit is composed of a three-phase bridge-connected inverter circuit provided between the DC busbars connected to the positive and negative terminals, which are the output terminals of the battery B. The output terminals of the driver circuit are connected to the three-phase windings constituting the stator of the motor 20.

[How to insert]
The following describes a driving method using the driving tool 10. In the initial state, the plunger 32 is in a standby position between the top dead center and the bottom dead center. In this state, when the operator holds the grip portion 12B and presses the tip of the contact arm 12D1, in which the injection port 12A is formed, against the driving member and then presses the trigger 12E, the battery B and the motor 20 are electrically connected, and the rotor of the motor 20 starts to rotate.

When the rotor of the motor 20 starts to rotate, the first gear 22A, which meshes with the gear directly connected to the output shaft of the motor 20, and the second gear 22B, which meshes with the first gear 22A, start to rotate. The torque roller provided on the second gear 22B contacts the gear engagement portion 32A1 of the plunger 32 and pushes the plunger 32 up in the separation direction DR2. Because the plunger 32 is connected to the moving member 38 by the wire 40, in conjunction with the movement of the plunger 32 in the separation direction DR2, the moving member 38 moves in the ejection direction DR1 while compressing the coil spring 36. The closer the plunger 32 is to the top dead center, the more the coil spring 36 is compressed, and the biasing force of the coil spring 36 becomes greater.

When the plunger 32 reaches the top dead center, the engagement between the plunger 32 and the gear (torque roller) 22 is released. As a result, the coil spring 36, which is in a compressed state, expands all at once. The moving member 38 moves together with the other end 36B of the coil spring 36 in the separation direction DR2, which is the direction in which the coil spring 36 expands. Since the moving member 38 is connected to the plunger 32 by the wire 40, the plunger 32 and the driver 34 move in the ejection direction DR1 in conjunction with the movement of the moving member 38 in the separation direction DR2. When the plunger 32 descends toward the bottom dead center, the driver 34, which moves in the ejection direction DR1 together with the plunger 32, ejects the fastener F supplied to the nose portion 12D in the ejection direction DR1. The fastener F is ejected from the injection port 12A.

Next, the rotor of the motor 20 starts to rotate in order to move the plunger 32, which is near the bottom dead center, to the standby position. The torque roller provided on the first gear 22A contacts the gear engagement portion 32A1 of the plunger 32 and pushes the plunger 32 upward in the separation direction DR2. To ensure the safety of the user, when the plunger 32 reaches the standby position, the rotor of the motor 20 stops rotating to prevent continuous operation, so that the rotor stops after each cycle. When the trigger 12E is released once and pressed again, the rotor of the motor 20 rotates again and the above-mentioned operation is repeated, repeatedly driving out the fastener F.

[Anti-run-through mechanism]
The driving tool 10 of this embodiment is equipped with an anti-empty strike mechanism that does not operate the driver 34 (plunger 32) when the magazine 14 runs out of fasteners F. One of the features of the anti-empty strike mechanism according to this embodiment is that it does not prevent empty strikes by restricting the movement of the contact arm 12D1, but rather prevents empty strikes by disengaging the engagement member 100 that presses the contact switch 124 from the contact arm 12D1, thereby preventing the driving operation of the fastener F by the driving method described above. An example of the anti-empty strike mechanism will be described below.

Figure 5 is a side view showing the internal structure of the driving tool 10 with the right half of the housing 12 removed, and shows the magazine 14 as seen from the outer wall side opposite the inner wall side shown in Figure 1. When the contact arm 12D1 is in the ON state position P2 shown in Figure 5, pulling the trigger 12E activates the driver 34 and drives out the fastener F, whereas when the contact arm 12D1 is in the OFF state position P1 shown in Figures 1 and 2, pulling the trigger 12E does not activate the driver 34.

As shown in FIG. 5, a blank-strike prevention mechanism is arranged on the outer wall side of the magazine 14, which is composed of a contact switch 124 that detects positions P1, P2 of the contact arm 12D1, and various parts that press the contact switch 124. The contact switch 124 forms an AND circuit with a trigger switch that detects the position of the trigger 12E on the circuit. The fastener F is not driven in unless the contact switch 124 and the trigger switch are simultaneously in the ON state.

In addition to the contact arm 12D1 described above, the nose portion 12D further comprises a flat base plate 111 fixed to the front end of the magazine 14, and a cover plate 112 fixed to the base plate 111 and positioned so as to sandwich the contact arm 12D1 between the base plate 111 and the cover plate 112.

Figure 6 is a partially exploded perspective view of the contact arm 12D1 shown in Figure 5. As shown in Figure 6, the contact arm 12D1 includes a nose plate 121, a guide plate 122, and an arm 123. The nose plate 121 slides up and down along a guide rail 111A (shown in Figures 7 and 8) of a base plate 111 fixed to the magazine 14.

When the tip of the nose plate 121 comes into contact with and is pressed against the workpiece, the contact arm 12D1 moves to position P2, which is the ON state. The guide plate 122 is fixed near the tip of the nose plate 121. A groove for guiding the fastener F is formed between the nose plate 121 and the guide plate 122.

The arm 123 extends rearward from the nose plate 121. As shown in FIG. 6, the arm 123 is composed of parts such as a shaft portion 125, a contact portion 126, a coil spring 127, and an adjustment dial 128. The shaft portion 125 is formed in a generally rod-like shape that penetrates the tip of the arm 123 from top to bottom, including the tip and a portion in the vicinity thereof, and has a threaded portion 1251 formed with a male thread that screws into the arm 123, and a tip portion 1252 that is inserted into a bottomed hole in the adjustment dial 128. The tip portion 1252 is formed in a cylindrical shape that can accommodate the coil spring 127. The coil spring 127 biases the arm 123 downward, that is, in the direction from the on-state position P2 to the off-state position P1.

The outer peripheral surface of the tip 1252 is processed to prevent rotation so that the adjustment dial 128 can slide in the Z-axis direction in FIG. 6, which is the axial direction of the shaft 125, but cannot rotate in the circumferential direction around the Z-axis. In the example shown, a pair of flat surfaces that face each other at 180° are formed on the outer peripheral surface of the tip 1252 (D-cut on both sides). The anti-rotation processing is not limited to the example shown, and may be D-cut on only one side or key groove processing. A known structure may be selected as appropriate. The bottomed hole of the adjustment dial 128 is formed to follow the outer peripheral surface of the tip 1252.

The adjustment dial 128 is exposed to the outside of the housing 12 through an opening formed in the housing 12. When the user operates the adjustment dial 128 to rotate it around the Z axis, the shaft portion 125, which is treated to prevent rotation, moves along with the adjustment dial 128. When the shaft portion 125 rotates, the arm 123 that screws into the threaded portion (feed screw) 1251 moves up and down relative to the threaded portion 1251. This makes it possible to adjust the driving depth of the fastener F.

In conventional machines, the member equivalent to shaft 125 and the adjustment dial for adjusting the driving depth were integrated into one structure, so the adjustment dial would move up and down every time contact arm 12D1 moved up and down between OFF position P1 and ON position P2. This meant that a large opening had to be formed in the member equivalent to housing 12 to expose the adjustment dial. The larger the opening, the more easily dust and other particles could enter the housing.

In contrast, in this embodiment, the adjustment dial 128 and the shaft portion 125 slide and are not fixed by a D-cut, so the opening formed in the housing 12 can be minimized. This improves the effectiveness of the housing 12 in suppressing the intrusion of dust and the like. In addition, since the position of the adjustment dial 128 does not move up and down, it can be positioned higher than before. The lower portion (tip portion) of the tool body 12 can be made slimmer, making it easier to work in tight spaces. Since the adjustment dial 128 is located away from the injection port 12A, it can be operated more safely.

Figure 7 is an oblique view showing the magazine 14 shown in Figure 5 with the contact arm 12D1, cover plate 112, etc. removed. As shown in Figure 7, a base plate 111 is fixed to the front end of an outer wall member 140 that constitutes the outer wall of the magazine 14. A spring 111B is attached to the base plate 111 to bias the contact arm 12D1 from the ON state position P2 toward the OFF state position P1.

In addition to the pusher 14A described above, the magazine 14 further includes an outer wall member 140. The outer wall member 140 of the magazine 14 includes a bearing 141 that supports the lower end of the shaft portion 125 of the arm 123, a bearing 142 that supports the upper end of the shaft portion 125, a guide 143 that guides the contact portion 126, and a support portion 144 that supports the engagement member 100.

Figure 8 is a bottom view showing nose portion 12D as viewed from below, with a portion cut away. As shown in Figure 8, outer wall member 140 is formed from a single plate material. Bearings 141, 142, guide 143, and support portion 144 shown in Figure 7, which support the moving parts, are all provided in the same outer wall member 140, so the tolerances of multiple parts do not accumulate, and the positional accuracy of the moving parts can be guaranteed.

Referring again to FIG. 7 for further explanation. In the illustrated example, the guide 143 is configured as a pair of ridges that sandwich the connection portion 123 from the front and rear and extend vertically in parallel. The contact portion (slider) 126 is formed, for example, from a metal material and slides vertically along the guide 143. An engagement member 100 that can engage with the contact arm 12D1 is provided on the outer wall of the magazine 14. When the contact arm 12D1 is in the on-state position P2 and the contact portion 126 and the engagement member 100 are engaged, the engagement member 100 presses the contact switch 124.

The engaging member 100 is rotatably supported by the support portion 144. In the illustrated example, the support portion 144 is configured as a shaft portion that is inserted into a bearing provided on the engaging member 100. The support portion 144 may be a bearing into which a shaft portion protruding from the engaging member 100 is inserted. In the illustrated example, the engaging member 100 includes a first member 101 rotatably supported by the support portion 144, and a second member 102 rotatably supported by the first member 101. The first member 101 is biased toward the contact portion 126 by a coil spring 145 attached to the outer wall of the magazine 14.

When the number of fasteners F remaining in the magazine falls below a predetermined number, the pusher 14A advances to the empty position. Until the pusher 14A reaches the empty position, the engaging member 100 biased by the coil spring (an example of a biasing member) 145 is engaged with the contact portion 126 of the contact arm 12D1. Figure 9 is a side view showing the state in which the contact arm 12D1 is waiting in the OFF position P1 and the contact portion 126 of the contact arm 12D1 is engaged with the engaging member 100. In the OFF position P1, the engaging member 100 does not press the contact switch 124.

Figure 10 is a side view showing the state in which the contact arm 12D1 has moved to the on-state position P2 and the contact portion 126 of the contact arm 12D1 is engaged with the engagement member 100. As shown in Figure 10, when the contact arm 12D1 is in the on-state position P2 and the contact portion 126 is engaged with the engagement member 100, the upper surface of the second member 102 of the engagement member 100 presses the contact switch 124.

When the trigger 12E is pulled in this state, the driver 34 is actuated to drive out the fastener F. On the inner wall side of the magazine 14, the pusher 14A advances according to the remaining amount of fasteners F contained in the magazine 14. As the pusher 14A advances, on the outer wall side of the magazine 14, the lever 14B, which moves in conjunction with the movement of the pusher 14A, approaches the engaging member 100. In the illustrated example, the lever 14B is formed integrally with the pusher 14A. In other words, the lever 14B constitutes a part of the pusher 14A. However, the structure of the lever 14B is not limited to the illustrated example, and the pusher 14A and the lever 14B may be formed separately.

Figure 11 is a side view showing the state in which the contact arm 12D1 is in the on-state position P2, but the contact portion 126 of the contact arm 12D1 is disengaged from the engaging member 100. When the pusher 14A advances to an empty position where the remaining number of fasteners F is less than a predetermined number (for example, the 0 fasteners position shown in Figure 2), the lever 14B presses the lower end of the first member 101 of the engaging member 100, as shown in Figure 11.

When pressed, the first member 101 rotates around the support portion 144 against the biasing force of the coil spring 145. In the illustrated example, the first member 101 rotates counterclockwise. When the lever 14B advances and presses the lower end portion 101A of the first member 101, the upper end portion 101B on the opposite side to the lower end portion 101A across the support portion 144, which is the center of rotation, retreats in the opposite direction to the tip of the lever 14B. As a result, the second member 102 of the engagement member 100 is released from engagement with the contact portion 126 and retreats to a position where it does not contact the contact switch 124.

The second member 102 is configured to be able to swing around a shaft portion provided at the upper end portion 101B of the first member 101. When the engagement between the contact portion 126 and the second member 102 is released, the free second member 102 swings in a direction away from the contact switch 124, i.e., downward.

According to the driving tool 10 of this embodiment configured as described above, blank strikes are prevented not by restricting the movement of the contact arm 12D1 from the OFF position P1 to the ON position P2, but by disengaging the engagement member 100, which presses the contact switch 124, from the contact arm 12D1, the contact arm 12D1 is prevented from pressing the contact switch 124, thereby preventing blank strikes.

This allows it to be used in a variety of ways, including drag driving. Compared to structures that restrict the movement of the trigger 12E, there are fewer layout restrictions on the internal structure of the driving tool 10. Since it is not affected by the detection accuracy of electrical components such as switches, blank strikes can be prevented with high precision. Since movable components such as the contact portion 126 and the engagement member 100 are supported by the same outer wall member 140, the tolerances of multiple components do not accumulate, and the positional precision of the movable components can be guaranteed.

The engaging member 100 includes a first member 101 supported by a support portion 144 and a second member 102 supported by the first member 101. In addition to the rotation of the first member 101 relative to the magazine 14, the movement of the engaging member 100 also includes the swinging of the second member 102 relative to the first member 101, so that the engaging member 100 can move a large amount in the direction in which it retreats from the contact switch 124. Because the movable part moves to the side opposite the nose portion 12D, it does not take up space in the nose portion 12D.

The above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. The elements of the embodiments, as well as their arrangements, materials, conditions, shapes, sizes, etc., are not limited to those exemplified, and may be modified as appropriate. Furthermore, configurations shown in different embodiments may be partially substituted or combined.

10 Driving tool 12 Housing (tool body)
12A Injection port 12B Grip portion 12C Bridge portion 12D Nose portion 12E Trigger 12F Trigger biasing member 14 Magazine 14A Pusher 14B Lever 20 Motor 22 Gear 22A First gear 22B Second gear 24 PCB board 30 Plunger assembly 30A Base 32 Plunger 32A First side wall portion 32A1 Gear engagement portion 32A2 Wire engagement portion 32B Second side wall portion 32C Third side wall portion 32C1 Driver engagement portion 32D Fourth side wall portion 34 Driver 36 Coil spring 36A One end of coil spring 36B The other end of coil spring 38 Moving member 38A Pin 38B Cylindrical portion 40 Wire 42 Pulley 44 Cylinder 44A Cylindrical portion 44B Hole 44C Cap portion 46 Guide rail 100 Engagement member 101 First member 101A Lower end portion 101B Upper end portion 102 Second member 111 Base plate 111A Guide rail 111B Coil spring 112 Cover plate 121 Nose plate 122 Guide plate 123 Arm 124 Contact switch 125 Shaft portion 1251 Threaded portion 1252 Tip portion 126 Contact portion 127 Coil spring 128 Spring seat member 140 Outer wall member 141 Bearing 142 Bearing 143 Guide 144 Support portion 145 Coil spring A Extension/contraction direction (central axis direction)
X Front-rear direction Y Left-right direction Z Up-down direction C Center axis B Battery DR1 Launch direction DR2 Separation direction F Fastener

Claims (4)

a contact arm provided on the tool body so as to be movable forward and backward, and which is pressed by the driving member to move from an OFF state position to an ON state position;
a contact switch that detects the position of the contact arm;
an engagement member that engages with the contact arm that has moved to the on-state position to press the contact switch;
a magazine capable of accommodating a plurality of fasteners;
a pusher that moves according to the remaining amount of fasteners contained in the magazine,
When the pusher moves to an empty position where the remaining amount of fasteners is equal to or less than a predetermined number, the engaging member retreats to a position where it does not come into contact with the contact switch, so that even if the contact arm moves to the on-state position, the engaging member and the contact switch do not come into contact with each other.
Driving tool. The contact arm has a contact portion that engages with the engagement member,
The engaging member is
When the contact arm is in the on position and the pusher is not in the empty position, the contact engages the contact to depress the contact switch;
When the pusher moves to the empty position, the pusher is pressed to release the engagement with the contact portion.
The driving tool according to claim 1 . the engaging member includes a first member supported by the magazine and a second member supported by the first member,
the second member engages with the contact arm to press the contact switch when the contact arm is in the on-state position and the pusher is not in the empty position;
when the pusher moves to the empty position, the first member is pressed by the pusher and rotates in a direction to release the engagement between the contact arm and the second member;
the second member is configured to be pivotable about the first member in a direction away from the contact switch when the second member is disengaged from the contact arm.
The driving tool according to claim 1 or 2 . The contact arm has a contact portion that engages with the engagement member,
a support portion for supporting the engaging member and a guide for guiding the movement of the contact portion are both provided on a same outer wall member constituting the magazine;
The driving tool according to any one of claims 1 to 3 .

Images