JP7137447B2 - driving tool - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving tool such as a rechargeable pin tacker, and relates to a mechanical spring type driving tool that utilizes the biasing force of a compression spring as driving force.

Driving tools such as pin tackers, which are mainly used for joining wood and plasterboard, use the thrust of a compressed air-driven cylinder as driving force, and also use the biasing force of an impact spring (compression spring) as driving force. A mechanical spring driven driving tool is provided. A conventional technology relating to the latter mechanical spring type driving tool is disclosed in Patent Document 1 below.

Patent Document 1 below describes a driver return mechanism for returning an impact driver to a rear end position on the rear side in the impact direction against the spring force of an impact spring. An electric motor is used as a drive source for this driver return mechanism. Engagement portions are arranged on respective side surfaces of the first and second return gears rotated by the electric motor, and the first and second engagement portions protrude from the driver pedestal supporting the impact driver. , a configuration is disclosed in which the impact driver is returned to the retracted end position in two steps by sequentially engaging the second engagement receiving portion.

As described above, in the conventional driver return mechanism, in order to secure a large return distance of the impact driver (a large impact force due to a large stroke in the driving direction), the first engagement between the first engaging portion and the first engagement receiving portion is provided. The impact driver is returned to the retracted end position through two stages of engagement states, namely, a engaged state and a second engagement state between the second engaging portion and the second engagement receiving portion.

Further, in a conventional driver return mechanism, both engagement portions are distributed among the two return gears such that the first engagement portion is arranged on the first return gear and the second engagement portion is arranged on the second return gear. By arranging it in the direction of

In the above-described configuration in which the two engaging portions are distributed to the two return gears, for example, when movement of the impact driver in the driving direction is restricted due to a problem such as clogging of the driving tool, the second engagement It is necessary to avoid an engagement state that does not occur in normal operation, such as collision of the first engagement receiving portion with the back side of the first engagement receiving portion. For this reason, in the conventional driver return mechanism, the second engaging portion is made shorter than the first engaging portion, and correspondingly, the amount of projection of the first engaging receiving portion is made larger than that of the second engaging receiving portion. By reducing the size, measures have been taken to prevent the second engaging portion from colliding with the first engagement receiving portion.

JP 2017-87414 A

However, in the above-described conventional driver return mechanism, the first and second engagement receiving portions protruding laterally from the spring axis of the impact spring that biases the driver pedestal are driven back by the electric motor as a drive source. Since it is configured to apply force, the return driving force is applied as a moment to the driver base portion. On the other hand, regarding the distance from the spring axis, the engagement position (first engagement position) of the first engagement portion with respect to the first engagement receiving portion is made closer to the spring axis, while the second engagement portion with respect to the second engagement receiving portion is closer to the spring axis. The engaging position (second engaging position) of the engaging portion was configured to be spaced apart from the spring axis. Therefore, the first stage in which the driver pedestal is positioned closer to the forward end position (the first half stage in which the driver pedestal is returned toward the backward end position by the engagement of the first engaging portion with the first engagement receiving portion). In the second stage (the latter stage in which the driver seat is returned toward the retracted end position due to the engagement of the second engagement portion with the second engagement receiving portion), the moment to the driver seat is larger than the second step. It was.

Moreover, since the load of the impact spring increases as the driver pedestal approaches the retracted end, the spring force (repulsive force) of the impact spring acting on the driver pedestal is greater in the latter half than in the first half. Two steps are bigger. Since the driver pedestal needs to be retracted against a larger spring force, the moment applied to the driver pedestal in the second stage of the latter half is also larger than in the first stage of the first half. In this way, the moment in the second stage becomes extremely large compared to the moment in the first stage, and the sliding frictional force applied to the slide support portion of the driver pedestal greatly changes between the first stage and the second stage, As a result of this being added to the slide support portion as a large return resistance, the durability of the slide support portion is impaired, or the meshing state of the gears changes greatly, easily causing damage to the gears. It also causes deterioration in the durability of the driver returning mechanism for returning to the retracted end position.

As a measure for equalizing the moment applied to the driver base portion in the first stage and the second stage, the first engaging portion and the second engaging portion are arranged in one return gear, and the above-mentioned and Conversely, by setting the second engaging portion longer than the first engaging portion so that the second engaging position with respect to the second engaging receiving portion is closer to the spring axis than the first engaging position. , to suppress the moment in the second stage of the latter half.

However, in the driver return mechanism that realizes two-stage engagement states with one return gear, if an attempt is made to secure a large return stroke while avoiding an increase in the diameter of the one return gear, the first engagement receiving portion Not only does the distance between the second engagement receiving portion and the second engagement receiving portion increase, but the forward end position (stop position) of the driver pedestal must be set to the front side of the electric motor. As for the position, the degree of freedom of arrangement is greatly restricted. If the stop position of the driver pedestal is set on the front side of the electric motor, the arrangement of the front members of the driving tool becomes cramped, and the grip portion is arranged on the front side closer to the injection port, resulting in product balance ( A problem arises that the operability of the driving tool is impaired.

The present invention provides a driver return mechanism that returns a driver pedestal to a retracted end position by means of an engagement state of an engaging portion with an engagement receiving portion generated by rotation of a return gear, wherein the driver pedestal can be arranged with respect to an electric motor. Aim to raise.

One feature of the present disclosure is a driving tool that uses the biasing force of a striking spring to move an impact driver in a driving direction to strike a driving tool. Such a driving tool includes an electric motor having a motor axis in a direction intersecting the driving direction, and a grip portion arranged behind the electric motor in the driving direction and extending along the motor axis. The driving tool also includes a driver return mechanism that uses an electric motor as a drive source and returns the impact driver to a rear end position on the rear side in the driving direction against the biasing force of the impact spring.

The driver return mechanism includes a return gear rotated by an electric motor, an engaging portion provided on the return gear, and an engagement receiving portion provided on the driver base portion that supports the impact driver and with which the engaging portion is engaged. and so that the driver seat is returned to the rearward end position by the engagement state of the engagement portion with the engagement receiving portion generated by the rotation of the return gear. Further, in this driver return mechanism, the rotational output of the electric motor is transmitted to the return gear via the idle gear.

According to one feature of the present disclosure, since the rotation output of the electric motor is transmitted to the return gear via the idle gear, the return gear is driven into the electric motor by the amount of the idle gear. In this way, the engaging portion provided on the return gear can be arranged further away from the electric motor, and the driver pedestal provided with the engagement receiving portion with which the engaging portion is engaged. The stop position can be set further rearward with respect to the electric motor.

By interposing the idle gear in this way, the stop position of the driver pedestal can be set to the rear side with respect to the electric motor. degree of freedom can be increased. By increasing the degree of freedom in arranging the driver pedestal, it becomes easier to configure the driver pedestal to be returned to the rearward end position by one return gear in a two-stage engagement state. By using one return gear to return the driver pedestal to the retracted end position in two stages of engagement, the moment applied to the driver pedestal is made uniform, and the peripheral structure such as the slide support portion is improved. Durability can be improved.

Another feature of the present disclosure is a configuration in which the idle gear is arranged with the rotation center at a position off the line connecting the output center of the electric motor and the rotation center of the return gear.

According to the above feature, in addition to the gear diameter of the idle gear, the arrangement of the idle gear increases the degree of freedom in the arrangement of the driver base.

Another feature of the present disclosure is that the driver return mechanism includes one return gear.

According to the above feature, compared to a configuration having two return gears, the configuration can be made more compact, and in this respect as well, the degree of freedom in arranging the one return gear is increased.

Another feature of the present disclosure is that one return gear is provided with at least two engaging portions, the driver base portion is provided with at least two engagement receiving portions corresponding to the engaging portions, and the engaging portions are engaged. The configuration is such that the driver base portion is returned to the retracted end position by a plurality of stages of engagement with the joint receiving portion.

According to the above feature, when the rotation of one return gear generates, for example, a two-step engagement state to return the driver pedestal to the rearward end position, the spring force of the impact spring is increased in two steps. The moment load applied to the eye can be made smaller than the moment load applied in the first step, so that the moment load applied to the driver pedestal can be uniformed. By equalizing the moment load in the process of retracting the driver pedestal, it is possible to reduce the abrasion of the slide support and peripheral structures and increase the durability thereof.

Another feature of the present disclosure is that the rotational output of the electric motor is reduced by a planetary gear train and transmitted to an idle gear.

According to the above feature, compared to a configuration in which the rotation output of the electric motor is reduced by the spur gear train, the configuration of the power transmission path from the electric motor to the return gear can be simplified. The degree of freedom in gear arrangement is increased.

Another feature of the present disclosure is that a space is generated on the front side in the driving direction by displacing the return gear rearward in the driving direction due to the interposition of the idle gear. In this driving tool, a contact arm is provided which is displaceably supported along the driving direction with respect to a driving nose section in which an impact driver is guided. A microswitch for detecting the ON position of this contact arm is arranged in the above space.

According to the above feature, the idle gear is interposed between the motor and the return gear, so that the return gear is arranged on the rear side in the driving direction, and the space generated by this on the front side in the driving direction can be effectively utilized. can. A driving tool of this type is provided with a contact arm mainly for the purpose of preventing malfunction. By arranging the microswitch for detecting the operation state of the contact arm in the space generated on the front side in the driving direction by interposing the idle gear, the configuration on the front side in the driving direction can be made compact. be able to.

1 is an overall side view of a driving tool according to this embodiment; FIG. This figure shows the internal structure. FIG. 11 is a side view of the striking mechanism and driver return mechanism; This drawing shows the state immediately before the impact driver is returned to the backward end position after reaching the forward end position. FIG. 3 is a plan view of the driver return mechanism seen from the direction of arrow (III) in FIG. 2 after the impact driver reaches the forward end position and immediately before being returned to the backward end position; FIG. 11 is a side view of the striking mechanism and driver return mechanism; This figure shows a stage during which the impact driver is being returned to the retracted end position. FIG. 5 is a plan view of the driver return mechanism seen from the direction of the arrow (V) in FIG. 4 at a stage in which the impact driver is being returned to the retracted end position; FIG. 11 is a side view of the striking mechanism and driver return mechanism; This figure shows a stage during which the impact driver is being returned to the retracted end position. FIG. 7 is a plan view of the driver return mechanism in the stage where the impact driver is being returned to the retracted end position and the return operation is transferred from the first stage to the second stage, as seen from the direction of the arrow (VII) in FIG. be. FIG. 11 is a side view of the striking mechanism and driver return mechanism; This figure shows the stage in which the percussion driver has been returned to the retracted end position. FIG. 9 is a plan view of the driver return mechanism when the impact driver is returned to the retracted end position, viewed from the direction of the arrow (IX) in FIG. 8; FIG. 10 is a side view of the percussion driver and driver return mechanism; This figure shows the state immediately after the striking driver has reached the forward end position and the striking operation has been performed. FIG. 11 is a plan view of the driver return mechanism as seen from the direction of the arrow (XI) in FIG. 10 immediately after the impact driver reaches the forward end position and the driving operation is performed;

An embodiment of the present invention will now be described with reference to FIGS. 1 to 11. FIG. As shown in FIG. 1, in the present embodiment, as the driving tool 1, a mechanical spring type and rechargeable finishing nailer that utilizes the biasing force of a compression coil spring as a striking force (driving force) is exemplified. The driving tool 1 of this embodiment includes a tool main body 10, a motor accommodating portion 12 containing an electric motor 13 as a drive source, a grip portion 16 to be gripped by a user, and a large number of driving tools T. magazine 19 and a power supply unit 20 . The tool main body 10 has a configuration in which a driver return mechanism 30 and a striking mechanism 40 are provided inside a main body housing 11 . In the following description, the driving direction of the driving tool is the front side, the counter driving direction is the rear side, and the lateral direction is based on the user.

A driving nose portion 2 that guides the impact driver 3 in the driving direction is provided on the front portion of the tool body portion 10 . As the impact driver 3 for impacting the driving tool moves forward in the driving passage 2a of the driving nose portion 2, the driving tool T is impacted and ejected from the ejection port 4 at the tip thereof. One driving tool driven out from the injection port 4 is driven into the material W to be driven as it is.

The driving nose portion 2 is provided so as to be displaceable within a certain range in the front-rear direction (the driving direction) with respect to the tool body portion 10 . The driving operation is performed only in a state in which the injection port 4 is pressed against the workpiece W and the driving nose portion 2 is retracted relative to the tool main body portion 10.例文帳に追加Therefore, the driving nose portion 2 also functions as a contact arm that is operated to allow the driving operation. An actuating arm portion 5 is coupled to the driving nose portion 2 . The operating arm portion 5 is displaced back and forth integrally with the driving nose portion 2 .

A single microswitch 6 is arranged behind the actuating arm portion 5 and at the front portion of the body housing 11 . When the driving nose portion 2 is retracted (turned on), the microswitch 6 is pushed by the operating arm portion 5 and turned on. One of the conditions is that the microswitch 6 for detecting the ON operation is in the ON state, and the driving operation is performed. A microswitch 7 for detecting the retraction end position of the impact driver 3 is arranged in the rear part of the body housing 11 . The microswitch 7 for detecting the backward end will be further described later.

The motor accommodating portion 12 and the grip portion 16 are provided in a state of protruding downward from the lower portion of the tool body portion 10 . The motor accommodating portion 12 is provided on the front side, and the grip portion 16 is provided on the rear side so as to extend substantially parallel to each other. An electric motor 13 that is a driving source of the driver return mechanism 30 is housed in the motor housing portion 12 on the front side. As shown in FIG. 1, the motor axis M of the electric motor 13 extends vertically in a direction intersecting (perpendicular to) the driving direction (front-rear direction). Details of the driver return mechanism 30 will be described later.

A magazine 19 is connected to the driving nose portion 2 . The magazine 19 extends downward along the front side of the motor accommodating portion 12 from the lower surface of the driving nose portion 2 . The magazine 19 is a case into which a plate-like connected driving tool in which a large number of driving tools T are temporarily fixed in parallel can be loaded. It has a function of feeding the driving tools T one by one into the driving passage 2a by pitch feeding to the nose portion 2 side.

Between the motor housing portion 12 on the front side and the grip portion 16 on the rear side, a space is provided for the user to insert one hand. The grip portion 16 is firmly grasped by the finger inserted into this space. A trigger-type switch lever 17 is provided on the upper portion of the grip portion 16 . A switch body 18 is installed behind the switch lever 17 . By pulling the switch lever 17, the switch body 18 is turned on and the electric motor 13 is started. The electric motor 13 can be started by pulling the switch lever 17 with the fingertip of the hand holding the grip portion 16 in a state in which the driving nose portion 2 is retracted to the ON position.

When the pulling operation of the switch lever 17 is released, the switch body 18 is turned off and the electric motor 13 is stopped. Further, even if the switch lever 17 is still being pulled, the electric motor 13 is automatically stopped after a certain period of time when the driver base 41 is returned to the rearward end and the rearward end sensor is turned on.

A power supply unit 20 is provided between the tip end portions of the motor housing portion 12 and the grip portion 16 . A battery mounting portion 21 is provided on the lower surface side of the power supply portion 20 . One battery pack 22 is attached to the battery attachment portion 21 . Electric power of the battery pack 22 is mainly supplied as a power source for the electric motor 13 .

A pair of left and right rail portions for mechanically coupling the battery pack 22 and positive and negative terminal plates for electrical connection are arranged in the battery mounting portion 21 . The battery pack 22 is a lithium-ion battery with an output voltage of 18V, and is a slide-mounted battery pack that can be removed by sliding it backwards and mounted on the battery mounting part 21 by sliding it forwards. The battery pack 22 can be used repeatedly by removing it from the battery mounting portion 21 and charging it with a separately prepared charger. Also, the battery pack 22 is a highly versatile battery pack that can be used as a power source for other power tools such as a rechargeable screwdriver and a cutting tool. Inside the battery mounting portion 21, a controller 23 having a control circuit board for controlling the operation of the electric motor 13 and a power supply circuit board is accommodated.

Details of the driver return mechanism 30 and the striking mechanism 40 are shown in FIG. 2 onwards. As shown in FIG. 2, the impact mechanism 40 housed in the tool main body 10 includes a driver seat portion 41 that supports the impact driver 3, and an impact spring 42 that biases the driver seat portion 41 in the driving direction. . A compression coil spring having a relatively large wire diameter and winding diameter is used for the impact spring 42 . The rear portion of the impact driver 3 is connected to the upper portion of the driver base portion 41 via the connecting pin 3a. The impact driver 3 is an elongated plate member and is always inserted into the impact passage 2a so as to be able to move forward and backward without rattling.

The driver base portion 41 is integrally provided with a cylindrical support portion 41a extending in the front-rear direction. On the other hand, the body housing 11 is provided with a round bar-shaped support shaft portion 43 . The support shaft portion 43 extends substantially over the entire length from the front portion to the rear portion of the main body housing 11 . A front portion and a rear portion of the support shaft portion 43 are coupled to the body housing 11 so as not to be displaceable in the axial direction and around the axis, respectively. An impact spring 42 is interposed around the support shaft portion 43 .

The driver pedestal 41 is slidably supported back and forth with respect to the body housing 11 by inserting the support shaft 43 radially into the inner peripheral side of the cylindrical support 41a without rattling. Further, the driver pedestal portion 41 is slidably supported in the front-rear direction while the displacement of the support shaft portion 43 about the axis is restricted. One impact spring 42 is interposed between the driver base portion 41 and the rear portion of the body housing 11 . The impact spring 42 biases the driver pedestal 41 and the impact driver 3 in the driving direction. Due to the urging force of the impact spring 42 , one driving tool T supplied into the driving passage 2 a is impacted by the impact driver 3 and ejected from the ejection opening 4 .

A forward end damper 44 is provided in the front portion of the body housing 11 to absorb the impact at the forward end position of the driver pedestal portion 41 . The forward end damper 44 has a cylindrical shape and is arranged along the periphery of the support shaft portion 43 . A cylindrical retaining sleeve 45 is arranged at the rear portion of the body housing 11 . The retaining sleeve 45 is arranged on the rear inner peripheral side of the impact spring 42 . As shown in FIG. 8, when the impact driver 3 is returned to the retracted end position and the impact spring 42 is contracted to the maximum, the holding sleeve 45 prevents the impact spring 42 from being caught due to bending or deformation.

The impact driver 3 is returned to the retracted end position by a driver return mechanism 30 that uses the electric motor 13 as a drive source. The rotation output of the electric motor 13 is reduced in speed by the planetary gear train 14 and output to the output gear 15 . The output gear 15 is meshed with one idle gear 31 (idle gear that does not have a speed-up/down function). The idle gear 31 is meshed with one return gear 32 . The idle gear 31 and the return gear 32 are rotatably supported on the upper surface side of the mechanism base 33 . The mechanism base 33 is a thin plate-shaped pedestal portion that extends forward and backward, and is fixed below the impact mechanism 40 and along the lower portion of the main body housing 11 .

The rotational output of the electric motor 13 is transmitted to the return gear 32 via the idle gear 31 . The rotation axis R of the return gear 32 is shifted rearward with respect to the output axis (motor axis M) of the electric motor 13 due to the interposition of the idle gear 31 . Further, as shown in FIG. 3, the rotation axis C (rotation center) of the idle gear 31 is shifted to the left from the line connecting the rotation axis R (rotation center) of the return gear 32 and the motor axis M (output center). It is arranged to be the position. By appropriately setting the number of teeth and the position of the idle gear 31, the position of the return gear 32 in the front-rear direction is set at a position at an appropriate distance from the motor axis M. As shown in FIG. The speed reduction ratio of the return gear 32 is determined by the gear ratio with the output gear 15, and is not affected by the interposition of the idle gear 31 as an idler gear. In addition, the rotational direction of the return gear 32 matches that of the output gear 15 due to the engagement of one idle gear 31 . In this embodiment, the direction of rotation of the return gear 32 is set to the counterclockwise direction as indicated by the outline arrow in FIG.

A first engaging portion 34 and a second engaging portion 35 are provided on the upper surface of the return gear 32 . The first engaging portion 34 and the second engaging portion 35 are cylindrical protrusions having substantially the same diameter, and are provided in a state of protruding upward. As shown in FIG. 2, the amount of upward protrusion of the first engaging portion 34 is approximately half that of the second engaging portion 35, and is low. Further, as shown in FIG. 3, the first engaging portion 34 and the second engaging portion 35 are arranged eccentrically by substantially the same distance from the rotation axis R of the return gear 32 . The first engaging portion 34 is arranged forward of the second engaging portion 35 by approximately 100° in the rotational direction. The interval in the rotational direction between the first engaging portion 34 and the second engaging portion 35 is appropriately set according to the timing of engagement with an engagement receiving portion, which will be described later.

A first engagement receiving portion 36 and a second engagement receiving portion 37 are integrally provided on the lower surface of the driver base portion 41 of the striking mechanism 40 so as to correspond to the first engaging portion 34 and the second engaging portion 35 . ing. The first engagement receiving portion 36 is arranged on the rear side, and the second engagement receiving portion 37 is arranged on the front side of the first engagement receiving portion 36 by a certain distance. The first engagement receiving portion 36 and the second engagement receiving portion 37 move back and forth integrally with the driver base portion 41 .

The first engagement receiving portion 36 and the second engagement receiving portion 37 are provided so as to project downward from the lower surface of the driver base portion 41 . As shown in FIG. 2, the amount of downward protrusion of the first engagement receiving portion 36 on the rear side is greater than the amount of downward protrusion of the second engagement receiving portion 37 on the front side. The first engagement receiving portion 36 protrudes further downward so that the lower first engaging portion 34 is engaged, while the second engagement receiving portion 37 protrudes downward so that the higher second engaging portion 35 is engaged. It protrudes downward by a sufficient protruding amount to be engaged.

Therefore, only the first engagement portion 34 is engaged with the first engagement receiving portion 36 on the rear side during the entire process of the displacement of the impact driver 3 in the striking direction and the return operation in the anti-striking direction. , and only the second engaging portion 35 is engaged with the second engaging receiving portion 37 on the front side. At any stage, the first engaging portion 34 with a small amount of upward protrusion is not engaged with the second engagement receiving portion 37 on the front side with a small amount of downward protrusion. The relative positions of the two are appropriately set so that the second engaging portion 35 projecting higher upward does not engage with the rear first engaging receiving portion 36 projecting greatly in the entire process. ing.

A first stage in which the first engaging portion 34 is engaged with the first engagement receiving portion 36, and a second stage in which the first engaging portion 34 is engaged with the first engagement receiving portion 36, and the second engaging portion 36 is a return operation stage of the impact driver 3 performed by one rotation of the return gear 32. By successively performing the second stage in which the joining portion 35 is engaged with the second engagement receiving portion 37, the driver base portion 41 and thus the impact driver 3 resists the urging force of the impact spring 42 and moves to the forward end. position to the retracted end position.

1, 2 and 3 show the state immediately after the driver return mechanism 30 is activated in the initial state (non-operating state) in which the impact driver 3 reaches the forward end position by the biasing force of the impact spring 42. FIG. there is The driver return mechanism 30 is activated prior to the driving operation. The driving nose portion 2 as a contact arm is retracted to turn on the microswitch 6, and the switch lever 17 is pulled to turn on the switch body 18. is turned on. When the switch body 18 is turned on, power supply to the electric motor 13 is started and the electric motor 13 is activated. When the electric motor 13 is activated, the driver return mechanism 30 starts operating.

When the electric motor 13 is activated, the return gear 32 begins to rotate counterclockwise as indicated by the white arrow in FIG. As the return gear 32 rotates, the first engagement portion 34 is pressed against the front surface of the first engagement receiving portion 36 . When the first engaging portion 34 is displaced rearward by the rotation of the return gear 32 while being pressed against the first engagement receiving portion 36, the driver base portion 41 moves toward the impact spring 42 as shown in FIGS. It is pushed backward against the biasing force. By pushing the driver base portion 41 rearward, the impact driver 3 is returned to the retreat end position side. In the first stage in which the first engaging portion 34 engages with the first engagement receiving portion 36 and the impact driver 3 is returned, the second engaging portion 35 gradually approaches the second engagement receiving portion 37. It has become.

Subsequently, the return operation shifts from the first stage to the second stage by rotating the return gear 32 counterclockwise. As shown in FIGS. 6 and 7, in this transitional stage, the first engaging portion 34 moves away from the front surface of the first engaging receiving portion 36, while the second engaging portion 35 moves away from the second engaging receiving portion 37. It will be in a state of being pushed forward. The drive source for the return operation due to the rotation of the return gear 32 is transferred from the first engagement portion 34 to the second engagement portion 35, and the return operation shifts from the first stage to the second stage. In the second stage of the return operation, the second engaging portion 35 is displaced rearward, so that the driver base portion 41 continues to retreat against the biasing force of the impact spring 42, and the impact driver 3 moves to the retracted end position. directed back.

8 and 9 show the stages in which the percussion driver 3 has been returned to the retracted end position. Immediately after the impact driver 3 is returned to the retracted end position, the second engaging portion 35 is separated from the second engagement receiving portion 37 by further rotating the return gear 32 . When the second engaging portion 35 separates from the second engaging receiving portion 37, the power to return the driver base portion 41 to the retracted end position side against the biasing force of the impact spring 42 is interrupted. And as shown in FIG. 11, the driver pedestal 41 advances due to the biasing force of the impact spring 42, so that the impact driver 3 moves forward in the driving passage 2a. The driving tool T is struck by the impact driver 3 and driven into the workpiece W while the impact driver 3 advances in the driving passage 2a.

As shown in FIGS. 8 and 9, when the driver pedestal 41 reaches the rearward end position, the first engaging portion 34 turns on the microswitch 7 as the rearward end sensor. When the microswitch 7 is turned on, the power supply to the electric motor 13 is interrupted and the electric motor 13 is stopped. When the electric motor 13 is stopped, the return gear 32 is stopped, so the displacement of the first engaging portion 34 and the second engaging portion 35 is stopped, and the driver return mechanism 30 is stopped. As shown in FIGS. 10 and 11, the impact driver 3 is positioned at the forward end position by the biasing force of the impact spring 42, and the stop state of the driver return mechanism 30 in which the electric motor 13 is stopped corresponds to the initial state of the driving tool 1. do.

According to the driving tool 1 according to the present embodiment configured as described above, in the driver return mechanism 30 that returns the impact driver 3 to the retracted end position, during one rotation of one return gear 32, the first engagement receiving portion A first step in which the first engaging portion 34 is engaged with 36 and a second step in which the second engaging portion 35 is engaged with the second engagement receiving portion 37 are successively stepped. As a result, the driver base portion 41 supporting the impact driver 3 is returned to the retracted end position with a large stroke. By ensuring a large stroke of the impact driver 3, the biasing force of the impact spring 42 can be effectively exerted and a large impact force can be received.

In the two-stage driver return mechanism 30 , the rotation output of the electric motor 13 as a drive source is transmitted to the return gear 32 via the idle gear 31 . By interposing the idle gear 31, the inter-axis distance between the rotation axis R of the return gear 32 and the motor axis M is made larger without increasing the diameter of the return gear 32 as compared with a configuration in which the idle gear 32 is not interposed. can be set, thereby placing the return gear 32 in a more rearward position.

Since the return gear 32 can be arranged further rearward with respect to the electric motor 13, the first and second engaging portions 34, 35 provided on the return gear 32 are arranged further rearward with respect to the electric motor 13. As a result, the forward end positions of the first engagement receiving portion 36 and the second engagement receiving portion 37 can be set further rearward.

Since the forward end positions of the first and second engagement receiving portions 36 and 37 are set on the rear side, the forward end position (stop position) of the driver pedestal portion 41 integrally having them is set by the electric motor. It can be set further back.

By interposing the idle gear 31 between the output gear 15 and the return gear 32 of the electric motor 13 in this manner, the stop position of the driver base portion 41 can be set further rearward with respect to the electric motor 13. By appropriately setting the arrangement of the gear 31 or the gear diameter, the degree of freedom in setting the stroke range of the driver base portion 41 can be increased. By increasing the degree of freedom in arranging the driver pedestal mainly for the forward end position, it becomes easy to configure the driver pedestal 41 to be returned to the backward end position by one return gear 32 in a two-stage engagement state.

By providing the first and second engaging portions 34 and 35 on one return gear 32 and creating a configuration in which two stages of engagement are generated in one rotation of the return gear 32, the engagement position in the second half of the second stage ( The engagement position between the higher second engaging portion 35 and the lower second engagement receiving portion 37) is the first half engagement position (the lower first engaging portion 34 and the higher 1 engagement position with the engagement receiving portion 36), the line of action of the impact spring 42 (the axis of the cylindrical support portion 41a passing through the center of the impact spring 42) is closer. Therefore, when the driver pedestal 41 is returned to the retracted end position, the moment applied to the cylindrical support portion 41a in the second stage, in which the resilience of the impact spring 42 increases, is reduced to the second stage, in which the resilience of the impact spring 42 decreases. It can be made smaller than the moment applied to the cylindrical support portion 41a in one step.

By reducing the moment of the second stage in which the elasticity of the impact spring 42 increases, the sliding resistance of the cylindrical support portion 41a with respect to the support shaft portion 43 can be made more uniform between the first half and the second half. It is possible to reduce uneven wear of the slide support portion (the cylindrical support portion 41a and the support shaft portion 43) of the portion 41 and the peripheral structure thereof, thereby enhancing the durability.

According to the driver return mechanism 30 of the present embodiment, the first and second engaging portions 34 and 35 are moved to the one return position in order to rotate one return gear 32 and generate two-step engagement states. It is arranged on the gear 32 so that the relative position does not change. In this respect, conventionally, the two return gears that are meshed with each other are provided with one engaging portion each to change the relative position. Therefore, immediately after the impact driver 3 starts moving in the driving direction from the retracted end position, both the first and second engaging portions 34 and 35 are aligned with the movement paths of the first and second engagement receiving portions 36 and 37. It becomes easier to place them appropriately so that they are evacuated to an area away from the . 9 and 11, immediately after the second engaging portion 35 is disengaged from the front surface of the second engagement receiving portion 37 and the impact driver 3 starts moving forward, the second While the first and second engaging portions 34 and 35 are retracted to the area on the right side with respect to the impact driver 3 (the sliding center of the driver base portion 41), the first and second engagement receiving portions 36 and 37 are retracted to the left side. Displace the region in the implant direction. For this reason, for example, when the impact driver 3 stops in the middle of movement due to a trouble such as jamming of the driving tool, the first or second engaging portions 34 and 35 do not move to the rear surfaces of the first or second engaging receiving portions 36 and 37. It is possible to reliably avoid a phenomenon such as interference with the

Further, according to the exemplified driver return mechanism 30, the axis line deviating from the line connecting the motor axis line M (output center) of the electric motor 13 and the rotation axis line R (rotation center) of the return gear 32 is the rotation axis line C (rotation center). Since the idle gear 31 is arranged as , in addition to the gear diameter of the idle gear 31 , the arrangement increases the degree of freedom in arranging the driver base portion 41 and the degree of freedom in setting the slide range.

Further, the illustrated driver return mechanism 30 is configured to return the impact driver 3 to the backward end position by two-step engagement states generated by one rotation of one return gear 32. In comparison with a configuration that realizes the engaged state of (1), the configuration can be made more compact, and the degree of freedom in arranging the one return gear can be increased.

Furthermore, since the rotation output of the electric motor 13 is reduced by the planetary gear train 14 and coaxially output from the output gear 15, it is compared to a structure in which the speed is reduced by a spur gear train instead of the planetary gear train 14. , the configuration of the power transmission path from the electric motor 13 to the return gear 32 can be simplified.

Further, according to the illustrated driver return mechanism 30, the idle gear 31 is interposed so that the return gear 32 is displaced rearward in the driving direction, thereby expanding the space on the front side in the driving direction. In the illustrated embodiment, a microswitch 6 for detecting the ON position of the driving nose portion 2 as a contact arm is arranged in the space on the front side in the driving direction, so that the space is effectively utilized, and the front side in the driving direction is used. The compactness of the configuration is achieved.

Further modifications can be added to the embodiments described above. For example, although the configuration in which one idle gear 31 is interposed between the output gear 15 and the return gear 32 is illustrated, a configuration in which a plurality of idle gears are interposed may be employed.

Further, although the configuration for returning the driver pedestal 41 to the retraction end position through the two-step engagement state has been exemplified, even in the configuration for returning to the retraction end position by the one-step engagement state, the output gear 15 of the electric motor and the return position are also possible. A configuration in which one or a plurality of idle gears 31 are interposed between the gear 32 can be employed.

In addition, although the configuration in which the two-stage engagement state is generated by one return gear 32 is illustrated, one engagement portion is provided for each of the two return gears, and the two-stage engagement state is generated by the two return gears. , the rotational power of the electric motor is transmitted to the return gear via the idle gear, thereby increasing the degree of freedom in setting the range of movement or the stop position of the driver pedestal.

In addition, the initial position of the driver pedestal, the timing of stopping the electric motor, etc., which is the initial state of the driving operation, can be appropriately changed and set in addition to the exemplified configuration.

Furthermore, although the DC power supply type driving tool 1 using the battery pack 22 as the power supply is illustrated, the driving tool using an AC power supply such as a commercial 100V power supply can be similarly applied.

T: Driving tool W: Material to be driven 1: Driving tool (rechargeable pin tacker)
2 Drive-in nose portion 2a Drive-in passage 3 Strike driver 4 Injection port 5 Actuating arm 6 Microswitch (for detecting ON operation of contact arm)
7 ... Microswitch (for detecting the backward end position of the driver pedestal)
DESCRIPTION OF SYMBOLS 10... Tool main-body part 11... Main-body housing 12... Motor accommodating part 13... Electric motor 14... Planetary gear train 15... Output gear M... Motor axis line 16... Grip part 17... Switch lever 18... Switch main body 19... Magazine 20... Power supply part 21... Battery mounting portion 22... Battery pack 23... Controller 30... Driver return mechanism 31... Idle gear (idle gear)
C... Rotational axis of idle gear 32... Return gear R... Rotational axis of return gear 33... Mechanism base 34... First engagement part 35... Second engagement part 36... First engagement receiving part 37... Second engagement Receiving portion 40 Impact mechanism 41 Driver base portion 41a Cylindrical support portion 42 Impact spring 43 Support shaft portion 44 Advance end damper 45 Holding sleeve

Claims (6)

A driving tool that strikes a driving tool by moving an impact driver in a driving direction by a biasing force of an impact spring,
An electric motor having a motor axis in a direction intersecting the driving direction, and a grip portion disposed on the rear side of the driving direction with respect to the electric motor and extending along the motor axis,
a driver return mechanism that uses the electric motor as a drive source and returns the impact driver to a rear end position on the rear side in the impact direction against the biasing force of the impact spring;
The driver return mechanism is
a return gear rotated by the electric motor;
an engaging portion provided on the return gear;
an engagement receiving portion provided on a driver pedestal portion that supports the striking driver and with which the engaging portion is engaged;
The driver pedestal is returned to the retracted end position by the engagement state of the engagement portion with the engagement receiving portion generated by the rotation of the return gear,
A driving tool configured such that a rotational output of the electric motor is transmitted to the return gear via an idle gear meshed between an output gear provided coaxially with the motor axis and the return gear . The driving tool of claim 1, comprising:
A driving tool in which the idle gear is arranged with the rotation center at a position deviated from the line connecting the output center of the electric motor and the rotation center of the return gear. The driving tool according to claim 1 or 2,
The driver return mechanism is a driving tool with one return gear. A driving tool according to claim 3,
The one return gear is provided with at least two engaging portions, the driver base portion is provided with at least two engagement receiving portions corresponding to the engaging portions, and the engaging portion is adapted to the engagement receiving portion. A driving tool configured such that the driver pedestal is returned to the retracted end position by a plurality of stages of engagement. A driving tool according to any one of claims 1 to 4,
A driving tool configured such that the rotational output of the electric motor is reduced by a planetary gear train and transmitted to the idle gear. A driving tool according to any one of claims 1 to 5,
The impact driver is guided in a space on the front side in the driving direction generated by displacing the return gear to the rear side in the driving direction due to the interposition of the idle gear, in the driving direction with respect to the driving nose portion. a driving tool having a microswitch disposed thereon for sensing the ON position of a contact arm displaceably supported along the .

Images