JP2658724B2 - Spring driven nail driver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plunger, which is biased downward, is lifted and released to drive a plunger and a driver connected thereto with a spring force, and the driver hits a staple provided at an injection port. The present invention relates to a spring-driven nail driving machine for driving into a material to be driven.

[0002]

2. Description of the Related Art A spring-driven nail in which a spring-biased plunger is lifted up against a spring biasing force and then released, and a staple is driven into a material to be driven such as wood by a driver attached to the plunger. A hitting machine has already been proposed, and there is known a tool in which a plunger is pulled up by a motor built in the tool to reduce the plunger pulling effort.

For example, in U.S. Pat. No. 4,811,885, a rotating body and a plunger cooperating with each other via a motor and a speed reduction mechanism are opposed to each other and fixed at a position eccentric from the rotation center of the rotating body. A mechanism for engaging a drive pin and a plunger to raise the plunger by a predetermined stroke is shown. Japanese Patent Laid-Open Publication No. Hei 2-284880 discloses that a predetermined lifting stroke of a plunger is provided by installing two driving pins on a rotating body and forming engaging projections corresponding to the respective driving pins on the plunger. There has been proposed a mechanism capable of reducing the diameter of the rotating body and reducing the size of the tool.

However, in the case of the above-mentioned US patent, since the plunger is lifted up by one drive pin provided on the rotating body, the plunger is moved up to a half rotation of the rotating body as much as possible (while the driving pin moves from the lowermost position to the uppermost position). Therefore, it is necessary to set the eccentricity of the drive pin large in order to move the plunger for a predetermined stroke, and it is necessary to increase the diameter of the rotating body, which increases the size of the tool. Further, since a large maximum torque acts on the motor, there is a problem that a large motor having a large output is required.

The mechanism disclosed in Japanese Patent Application Laid-Open No. 2-284880 solves the problem of the above-mentioned U.S. Pat. Since about 3/4 of the rotation of the body is used for the movement of the plunger, the diameter of the rotation body for a predetermined stroke can be made smaller, and the diameter of the rotation body (the eccentric radius of the drive pin) becomes smaller. Is relatively small, and downsizing is possible. However, the load required to pull up the plunger against the spring force increases as the plunger approaches the top dead center, and a large torque is required at the end of the lifting stroke. On the other hand, in the above-mentioned technology, the two drive pins provided on the rotating body are arranged at the same distance from the rotation center of the rotating body. Requires a larger drive torque than the drive pin that engages with the drive pin. Therefore, in the above mechanism, a motor corresponding to the maximum torque generated at the subsequent drive pin is required, and there is a limit to downsizing of the motor. In other words, since the torque required for the same motor is different between the first half and the second half of the pulling up of the plunger, when a motor corresponding to the maximum torque in the second half is used, it is wasteful to pull up by the driving pin in the first half. I will.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to eliminate the above-mentioned drawbacks and to reduce the load on the motor evenly by equalizing the maximum torque applied to each of the plurality of drive pins when sequentially pulling up the plunger using the plurality of drive pins. Accordingly, it is an object of the present invention to provide a spring-driven nail driver in which the size of a tool can be reduced.

[0007]

To achieve the above object, a spring driven nailer according to the present invention comprises a plunger constantly biased downward by a spring and a driver fixed to the plunger. A nailing machine configured to sequentially launch nails in a magazine, wherein at least two rotating bodies cooperating with a motor via a speed reduction mechanism are arranged side by side along the moving direction of the plunger in opposition to the plunger. A drive pin is provided on each of the rotating bodies so as to protrude toward a side surface of the plunger at a position eccentric from the rotation center of each of the rotating bodies, while a side surface of the plunger is provided with a mechanism corresponding to each of the drive pins. The abutment portion is formed at a position where the driving pin moves in accordance with the rotation of the rotating body and sequentially engages with each driving pin to move the plunger against the spring force. In addition, the amount of eccentricity of the drive pin, which engages with the engagement projection, from the center of the rotating body at the initial stage of the lifting stroke of the plunger is determined by the eccentricity of the drive pin, which later engages with the engagement projection, from the rotation center of the rotation body. The amount is set to be larger than the amount.

In addition, a single rotating body is disposed in opposition to the plunger in place of the at least two rotating bodies, and at least two drive pins are eccentric to each other from the rotation center of the rotating body. On the side of the plunger, engaging projections respectively corresponding to the respective drive pins are sequentially provided so as to correspond to the respective drive pins when the drive pins move with the rotation of the rotating body. The plunger is formed at a position where the plunger is lifted and moved against the spring force, and at the beginning of the plunger's lifting stroke, the drive pin is engaged with the engagement protrusion from the center of the rotating body of the drive pin. The amount of eccentricity may be set so as to be larger than the amount of eccentricity of the drive pin that later engages with the engagement protrusion.

[0009]

According to the above construction, when the drive pins move with the rotation of the respective rotating bodies driven by the motor, the engagement projections of the plunger are sequentially engaged with the respective drive pins. Move the plunger against the spring force. Then, when the driving pin of the rotating body and the engaging projection which are finally engaged are disengaged, the plunger is driven by the spring force, and the driver hits the nail to drive the nail.

The amount of eccentricity of the drive pin, which engages with the engaging projection at the latter stage of the plunger lifting stroke and lifts the plunger, from the center of rotation of the rotating body is engaged early in the plunger lifting stroke. Since it is set smaller than the eccentric amount of the drive pin, it is not necessary to increase the load on the motor even in the latter half of the plunger lifting stroke in which a large load occurs. Therefore, the maximum torque applied to each drive pin is made uniform throughout the entire lifting stroke of the plunger, so that the load on the motor can be reduced evenly and waste can be reduced, and the size of the motor and the tool can be reduced.

In addition, the amount of pulling up of the plunger in the latter stage of pulling down is reduced due to the decrease in the amount of eccentricity of the drive pin of the upper rotary gear. This can be compensated for by setting the eccentricity of the drive pin large and increasing the amount of pulling, and a sufficient amount of lifting can be secured as a whole.

In addition, a single rotating body is disposed in opposition to the plunger instead of the plurality of rotating bodies,
The same effect can be obtained even when at least two drive pins are provided on the rotating body so as to protrude at positions eccentric from the rotation center of the rotating body.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIGS. 1 and 2 show an embodiment of a spring driven nail driving machine, in which a connecting nail (connecting staple) N is loaded in the front of a tool body 1. FIG. A plunger 4 integrally formed with a magazine 2 and a driver 3 for driving a nail N are provided, a drive mechanism for the plunger 4, and a switch mechanism for operating the drive mechanism.

An ejection port 5 is formed at the front end of the magazine 2, and the leading nail N1 of the connecting nail N is supplied to the ejection port 5 by a supply device (not shown).

The plunger 4 is a cylindrical member having a bottom. A bumper 6 is mounted on the lower bottom, and the driver 3 is connected to the front side surface. The plunger 4 is vertically movable by a guide means such as a cylinder, and is constantly urged downward by a compression spring 7. The tip of the driver 3 is located at the injection port 5 of the tool body 1.

The driving mechanism of the plunger 4 is
And two rotating gears (rotating bodies) 8 and 9 having the same diameter, which are arranged side by side along the moving direction (up and down direction) of the plunger 4.
And a motor 10 linked to the lower rotary gear 8 via a reduction mechanism.

The upper and lower rotating gears 9 and 8 are supported by bearings so as to mesh with each other. One drive pin 12, 11 is provided on each of the rotating gears 9, 8 so as to project toward the side surface of the plunger 4. On the other hand, plunger 4
Are formed on the side surfaces with engaging projections 14, 13 corresponding to the drive pins 12, 11, respectively. When the plunger 4 is at the bottom dead center position as shown in FIG. 2, the lower engagement projection 13 moves the drive pin 11 from the lowermost initial position on the movement locus of the drive pin of the lower rotary gear 8. Drive pin 1 when it starts moving (circular motion) in the circumferential direction and starts to rise
1 is arranged at a position where it engages with the first. Upper engaging projection 1
The upper rotary gear 9 is located just before the plunger 4 moves upward and the drive pin 11 of the lower rotary gear 8 reaches the uppermost position.
In FIG. 3, it is arranged at a position where it engages with the drive pin 12 which starts to rise from the bottom (see FIG. 3 (c)). As described above, the lower engaging projection 13 and the upper engaging projection 14 are connected to each other by the rotation of the upper and lower rotating gears 9, 8.
When the plunger 4 is moved, the plunger 4 is formed at a position where the plunger 4 is lifted up against the spring force by being sequentially engaged with the driving pins 12 and 11.

Also, as shown in FIG.
Of the drive pin 11 of the upper rotary gear 9 is set to be larger than the amount of eccentricity of the drive pin 12 of the upper rotary gear 9 eccentric from the rotation center.

According to the plunger drive mechanism, when the motor 10 is started, the driving force is transmitted from the output shaft to the upper and lower rotary gears 9 and 8 via the speed reduction mechanism. , 8 simultaneously begin to rotate in opposite directions. When the lower rotary gear 8 rotates, the drive pin 11
Also moves and begins to rise from the bottom, as shown in Fig. 3 (a).
As shown in (b), the lower surface of the engaging projection 13 of the plunger 4 is engaged with the lower surface, so that the plunger 4 is lifted up against the compression spring 7 as the lower rotary gear 8 rotates. Then, as shown in FIG. 3C, immediately before the drive pin 11 reaches the uppermost part, the drive pin 12 of the upper rotary gear 9 starts to rise from the lowermost part, and the engagement protrusion 14 on the upper part of the plunger 4 Since the plunger 4 is engaged with the lower surface, the plunger 4 is continuously moved up. When the drive pin 12 of the upper rotary gear 9 is disengaged from the upper engaging projection 14 beyond the state shown in FIG. 4D, the plunger 4 loses its support, and is lowered by the compression spring 7. Driven. At this time, the driver 3 coupled to the plunger 4 strikes the nail supplied to the injection port 5 and strikes the nail toward an external material to be driven (not shown), thereby completing one cycle of the nail driving operation.

A drive circuit including a motor 10, a battery 15 and a micro switch 16 is incorporated in the tool body 1. The operation of the motor 10 is started by turning on the micro switch 16 for opening and closing the drive circuit. The micro switch 16 is turned off after the plunger 4 is operated only for one cycle, and is controlled by a switch mechanism. The switch mechanism is configured to be operable only by a pulling operation of the trigger lever 17 and a sensing operation of the contact member 18 for sensing that the material to be driven is present at the tip of the injection port 5.

First, a switch operation unit 19 is arranged between the trigger lever 17 and the microswitch 16. As shown in FIG. 4, the switch operation unit 19 turns the switch operating member 22 around a vertical support shaft 23 on a support 21 pivotally mounted on a rear end portion of the trigger lever 17 via a horizontal support shaft 20. It is pivotally connected. An engagement piece 24 protruding upward is formed on one side in front of the support 21, an engagement portion 25 is bent at an upper end thereof, and a stopper 26 is formed on a side of the support 21. ing. The switch operating member 22 is formed in an L shape, a hanging piece 27 is formed from a front end, and a bearing hole 28 of a support shaft 23 provided perpendicular to the support base 21 is formed at a rear end. The switch operating member 22 is always engaged with the stopper piece 26 of the support base 21 by a torsion coil spring 29 (see FIG. 1) wound around the support shaft 23, and the upper surface thereof is the switch of the microswitch 16. It is urged to be located below the button 30.

Next, the switch operation unit 19
The switch operating member 22 is urged by a spring 31 provided on the tool body 1 so as to be separated from the switch button 30 of the micro switch 16, and the engaging portion 25 of the engaging piece 24 of the support base 21 is Member 18
The hanging piece 27 of the switch operating member 22 is formed to engage with the switch release pin 31 of the upper rotary gear 9 (see FIGS. 1 and 2).

The contact member 18 has a contact arm 18b projecting rearward from an upper end of an operating portion 18a projecting downward from the injection port 5 together with the driver 3 and is arranged on the tool body 1 so as to be vertically movable. The tip of the contact arm 18b is connected to the switch operation unit 1
It is arranged so as to engage with the lower surface of the engaging portion 25 of the engaging piece 24 of the support stand 9 to support the front end of the switch operation unit 19.

The switch release pin 31 is provided on the side of the upper rotary gear 9 opposite to the drive pin 12 so as to protrude from an extension of a line connecting the rotation center and the drive pin 12. It moves in the circumferential direction as it rotates. When the switch release pin 31 engages with the hanging piece 27 of the switch operating member 22 while the upper rotating gear 9 is rotating as shown in FIG. 4, the hanging piece 27 moves in the rotating direction with the rotation of the upper rotating gear 9. Moved. For this reason, the switch operating member 22 rotates about the support shaft 23 on the support base 21, and the upper surface moves so as to be disengaged from the switch button 30 of the microswitch 16.

According to the switch mechanism having the above-described structure, when the lower end of the contact member 18 is pressed against the material to be driven to move the contact member 18 upward with respect to the tool body 1, FIG.
As shown in (a), the tip of the contact arm 18b pushes up the engaging portion 25 of the support 21 of the switch operation unit 19, and rotates the front end of the support 21 so as to move upward. In this state, when the trigger lever 17 is further pulled upward to move the rear end of the support 21 upward as shown in FIG. 4B, the entire switch operation unit 19 moves upward. The upper surface of the operating member 22 presses the switch button 30 of the micro switch, and the driving mechanism of the plunger 4 starts operating. In contrast, simply pressing the contact member 18 against the material to be driven or operating only the trigger lever 17 merely tilts the switch operating member forward or backward, and does not turn on the microswitch 16.

Next, when the microswitch 16 is turned on and the motor 10 operates, the driver 3 is driven as described above and the nail driving operation is completed. However, the motor 10 continues to rotate and rises from below. As shown in FIG. 6 (a), the switch release pin 31 of the upper rotating gear 9 engages with the hanging piece 27 of the switch operating member 22.
Is pushed laterally to rotate the switch actuating member 22, so that the upper surface is disengaged from the switch button 30 of the micro switch as shown in FIG. Stops at the initial position shown in FIG. 1 and the next nail driving is prepared.

As described above, according to the spring-driven nailing machine having the above-described structure, the driving pin 12 which engages with the upper engaging projection 14 in the later stage of the lifting stroke of the plunger 4 to raise the plunger 4. Is set smaller than the amount of eccentricity of the drive pin 11 engaged with the lower engaging projection 13, so that the eccentric amount of the plunger 4 at the later stage of the lifting stroke of the plunger 4 where a large load occurs is set. There is no need to increase the load on the motor 10. Therefore, the maximum torque applied to the upper and lower drive pins 12 and 11 can be made uniform throughout the entire lifting stroke of the plunger 4, thereby reducing the load on the motor 10 evenly and reducing waste. Can be reduced in size.

In addition, the amount of pulling of the plunger 4 in the latter stage of the pulling is reduced due to the decrease in the amount of eccentricity of the drive pin 12 of the upper rotary gear 9, but this decreases at the beginning of the pulling stroke. This can be compensated for by setting the eccentricity of the drive pin 11 of the lower rotary gear 8 to be large and increasing the amount of pulling, thereby ensuring a sufficient amount of pulling as a whole.

The rotating body does not need to be a gear. An arm may be used as long as it rotates. Further, the number of rotating bodies for lifting and moving the plunger 4 is not necessarily limited to two. There may be three or more, or one. 3
In the case of more than one, it may be configured in the same manner as described above.

In the case of a single rotating body, FIGS. 7 (a), (b) and (c)
As shown in (d), the rotating body 32 has two drive pins 3.
The first and second drive pins 33 and 34 having a large eccentricity from the rotation center and a first driving pin 33 having a small eccentricity are provided on the side surface of the plunger 4. What is necessary is just to comprise so that the upper engaging protrusion 35 and the lower engaging protrusion 36 respectively corresponding to the 2 drive pins 34 may be formed. Also in this case, the upper engagement projection 35 and the lower engagement projection 36 are connected to each other when the first drive pin 33 and the second drive pin 34 move with the rotation of the rotating body 32. The plunger 4 is formed at a position where it is engaged with the pins 33 and 34 in sequence to lift the plunger 4 against the spring force. That is, the upper engaging protrusion 35 is disposed at a position where the rotating body 32 rotates and starts to ascend from the lowermost position to engage with the first drive pin 33, and the lower engaging protrusion 36 is
The plunger 4 is pulled up against the spring force and the first
Immediately before the drive pin 33 reaches the uppermost position, it is arranged at a position where it engages with the second drive pin 34 which starts to rise from the lowermost position.

Also in the case of the above construction, the first engagement with the upper engagement projection 35 in the latter half of the stroke of the plunger 4 is also possible.
The second drive pin 34 engaging with the lower engagement projection 36 than the drive pin 33 has a larger load for pulling up the plunger 4, but a large amount of eccentricity allows a large drive torque to be obtained. Therefore, the maximum torque applied to the upper and lower drive pins is made uniform throughout the entire lifting stroke of the plunger 4, so that the load on the motor 10 can be reduced evenly and waste can be reduced. In addition, by setting the eccentric amounts of the drive pins 33 and 34 of the rotating body 32 to be engaged with the engagement projections 35 and 36 of the upper and lower portions at the beginning of the lifting stroke and increasing the lifting amount, the entire amount is sufficiently increased. A large amount of lifting can be secured.

Also in this example, three or more drive pins having different eccentric amounts and corresponding drive pins may be arranged.

In another embodiment of the present invention, in addition to the above, a plurality of rotating bodies may be provided, and one or more of the rotating bodies may be provided with a plurality of driving pins.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a spring driven nail driver according to the present invention.

FIG. 2 is a cross-sectional view taken along line XX of FIG.

FIGS. 3 (a), (b), (c) and (d) are explanatory views of the manner of raising the plunger.

FIG. 4 is a perspective view of a switch operation unit.

FIGS. 5 (a) and 5 (b) are explanatory diagrams of an operation mode of a switch-on operation of a switch operation unit.

FIGS. 6 (a) and 6 (b) are explanatory diagrams of an operation mode of a switch-off operation of a switch operation unit.

FIGS. 7 (a), (b), (c) and (d) are explanatory views of an operation mode of another example of a spring driven nail driver.

[Explanation of symbols]

 2 Magazine 4 Plunger 7 Compression Spring 8 Rotating Gear 9 Rotating Gear 10 Motor 11 Drive Pin 12 Drive Pin 13 Engagement Projection 14 Engagement Projection 33 First Drive Pin 34 Second Drive Pin 35 Upper Engagement Projection 36 Lower engaging projection

Claims (2)

(57) [Claims] 1. A nailing machine in which a plunger constantly urged downward by a spring and a nail fixed in the plunger punches out nails in a magazine sequentially, the motor being driven through a speed reduction mechanism. At least two rotating bodies cooperating with the plunger are arranged side by side along the moving direction of the plunger in opposition to the plunger, and a drive pin is provided on each of the rotating bodies at a position eccentric from the rotation center of each rotating body. On the side of the plunger, an engaging protrusion corresponding to each of the drive pins is provided on the side of the plunger, and each drive pin is moved when the drive pin moves with the rotation of the rotating body. The plunger is formed at a position where the plunger is moved against the spring force and is engaged with the engaging projection at the beginning of the lifting stroke of the plunger. A spring driven nail, wherein the amount of eccentricity of the pin from the center of the rotating body is set to be larger than the amount of eccentricity of the driving pin to be later engaged with the engagement protrusion from the center of rotation of the rotating body. Hammer. 2. A single rotating body is disposed in opposition to the plunger in place of the at least two rotating bodies, and at least two drive pins are eccentric to each other from a rotation center of the rotating body. On the side of the plunger, engaging projections respectively corresponding to the respective drive pins are sequentially provided so as to correspond to the respective drive pins when the drive pins move with the rotation of the rotating body. The plunger is formed at a position where the plunger is lifted and moved against the spring force, and at the beginning of the plunger's lifting stroke, the drive pin is engaged with the engagement protrusion from the center of the rotating body of the drive pin. 2. The spring-driven nailer according to claim 1, wherein the amount of eccentricity is set to be larger than the amount of eccentricity of the drive pin which is later engaged with the engaging projection.