JP2021160030A - Driving tool - Google Patents

Abstract

To provide a driving tool with a structure capable of making driving timing of the driver accurate in order to prevent wear caused between the pinion for moving up the driver of the driving tool and the clutch for transmitting the power by releasably engaging with the pinion.SOLUTION: A driving tool 1 comprises a driver 11 provided vertically movably in a main body housing and moving down to strike the driving tool. The driver 11 is provided with a rack 12 for moving up the driver 11. The rack 12 is meshed with a pinion 32, which rotates to move up the driver 11. Moving up the driver 11 causes driving energy to be stored into a driver return mechanism 20. A top dead center detection sensor detects a position of a top dead center of the driver 11. A controller transmits a striking signal in response to a response signal from the top dead center detection sensor. A clutch 33 shuts off a power transmission path 37 between the pinion 32 and an electric motor in response to the striking signal.SELECTED DRAWING: Figure 3

Description

The present invention relates to a driving tool for driving a driving tool such as a nail or a staple into wood or the like.

As the driving tool, for example, a gas spring type and a spring type are known. The gas spring type driving tool disclosed in Patent Documents 1 and 2 has a driver for striking the driving tool, and a rack and a pinion for moving the driver upward. The rack is provided on the driver, which is integrated with the piston. The pinion rotates, the rack, driver and piston retract, and the pressure of the gas in the accumulator that communicates with the cylinder rises. Using the pressure of the gas stored in the accumulator chamber, the piston and driver move forward and the driver hits the driving tool.

The driving tool of Patent Document 2 has a clutch mechanism between the pinion and the motor. The clutch mechanism has an engaging member pressed against the pinion. When the driver rises and the pressure of the gas in the accumulator reaches a predetermined pressure, the engaging member moves away from the pinion by utilizing the inclination of the claw, and the claw is released from the pinion. This cuts off the power from the motor to the pinion and moves the driver down with the rack.

Japanese Patent No. 6260944 Japanese Patent No. 6311930

However, the timing at which the clutch is disengaged depends on the strength of the spring that urges the engaging member, the inclination angle of the claws of the engaging member, the pressure of the gas in the accumulator chamber, and the like. Therefore, it is difficult to accurately release the clutch. Moreover, since the claws of the engaging member are urged by the non-engaging member, they may slide against the pinion that rotates at high speed at the time of disengagement and may be worn. Therefore, there is a demand for a structure that can make the driving timing accurate.

In one feature of the present disclosure, the driving tool has a driver that is movably provided in the housing and moves downward to hit the driving tool. A rack is provided on the driver to move the driver upwards. The pinion engages the rack and rotates to move the driver upwards. Driving energy is stored in the drive mechanism by moving the driver upward. The sensor detects the position of the driver's top dead center. The controller emits a striking signal in response to the response signal from the sensor. The clutch shuts off the power transmission path between the pinion and the motor in response to the striking signal.

Therefore, when the driver reaches top dead center, the force from the pinion to the rack is cut off. As a result, the driver moves downward together with the rack, and the driving work is performed. Since the top dead center of the driver is detected by the sensor, the reproducibility is high and the driving timing can be accurate.

In another feature, the driving tool has a switch that operates by passing an electric current through the solenoid in response to a striking signal. The switch activates the clutch. Therefore, by using a switch, the start time and end time of clutch disengagement can be easily or preferably set. As a result, wear of the clutch can be suppressed.

In another feature, the switch has pins that appear and disappear by solenoids. The switch is configured to convert the force or the amount of displacement due to the displacement of the pin and transmit it to the clutch. Therefore, by converting the force and displacement of the pin moved by the solenoid and transmitting it to the clutch, the clutch can be operated with the optimum settings corresponding to various different conditions. For example, the clutch can be operated with a force larger than the force from the pin. Alternatively, the clutch can be operated with a movement amount larger than the movement amount of the pin.

In another feature, the clutch moves between an engaging position that is located on the pinion's axis of rotation and engages the pinion along the axis of rotation and a disengagement position that separates it from the pinion. Therefore, for example, the clutch can be made relatively small. Alternatively, the clutch can be switched between the engaging position and the disengaging position with a relatively short movement distance.

In another feature, the clutch has meshing teeth on the surface facing the pinion. The pinion has meshing teeth on the surface facing the clutch. Therefore, by moving the clutch on the rotation axis of the pinion, it is possible to switch between a state in which the meshing teeth mesh with each other and a state in which the meshing teeth are separated from each other.

In another feature, the driving tool has a spring that urges the clutch towards the pinion. Therefore, by using a spring, the power transmission between the motor and the pinion can be maintained. That is, the clutch can be held in an inactive state without using electric power.

In another feature, the pinion has multiple teeth all around. Therefore, the pinion can be made smaller in diameter. For example, the pinion described in Patent Document 1 includes a plurality of teeth in the circumferential direction and a non-engagement region having no teeth. The pinion of this feature has a small diameter because it does not have an unengaged region.

In another feature, the pinion is in constant mesh with the rack. Therefore, it is not necessary to consider the timing at which the pinion and the rack engage with each other and the timing at which they are disengaged. That is, since it is not necessary to consider the phase, the degree of freedom in the number of teeth and the size of the diameter of the pinion is high.

It is a vertical cross-sectional view of the driving tool which concerns on this embodiment. This figure shows the driving standby state. FIG. 1 is a cross-sectional view taken along line II-II in FIG. FIG. 2 is a cross-sectional view taken along the line III-III in FIG. It is an exploded perspective view of a clutch mechanism. It is a block diagram which shows each electric part of a driving tool schematicly. FIG. 1 is a vertical cross-sectional view of a driving tool corresponding to a cross-sectional view taken along line II-II in FIG. This figure shows the state immediately before hitting. FIG. 6 is a cross-sectional view taken along the line VII-VII in FIG. FIG. 1 is a vertical cross-sectional view of a driving tool corresponding to a cross-sectional view taken along line II-II in FIG. This figure shows the state of the driver at the start of upward movement after hitting. FIG. 8 is a cross-sectional view taken along the line IX-IX in FIG.

The driving tool 1 according to the embodiment of the present disclosure will be described with reference to FIGS. 1 to 9. In the present embodiment, as the driving tool 1, a gas spring type driving tool that uses the gas pressure of the gas sealed in the accumulator chamber 3a as a thrust for driving the driving tool n is illustrated. As shown in FIG. 1, the driving tool 1 includes a tool main body 10 in which a cylinder 3 is built in a cylindrical main body housing 2. The cylinder 3 supports the striking piston 7 so as to be able to reciprocate up and down. A driver 11 for striking the driving tool n (see FIG. 2) is provided at the center of the lower surface of the striking piston 7. The driver 11 extends long downward. The tip 11a of the driver 11 has entered the driving passage 5a of the driving nose portion 5 provided on the lower surface side of the tool body 10. At the lower end of the driving nose portion 5, an injection port 5b for ejecting the driving tool n is opened. In the following description, the downward direction is defined as the driving direction.

As shown in FIG. 1, a magazine 6 loaded with a large number of driving tools n (see FIG. 2) is coupled to the driving nose portion 5. A handle portion 4 for the user to grip is provided on the side portion of the main body housing 2. A switch lever 8 is provided at the base of the handle portion 4 so as to be pulled by the fingertips of the gripped hand. A battery pack 9 is attached to the tip of the handle portion 4 as a power source. The battery pack 9 can be repeatedly charged by removing it from the handle portion 4 and using a separately prepared charger. The battery pack 9 can be used as a power source for other power tools. The main body housing 2, the handle portion 4, the magazine 6, the switch lever 8, and the battery pack 9 are shown only in FIG. 1, and are not shown in FIGS. 2 and later.

As shown in FIG. 2, the driving nose portion 5 has a driver returning mechanism 20 for integrally returning the striking piston 7 and the driver 11 upward. The driver return mechanism 20 returns the striking piston 7 upward via the driver 11. As a result, the gas pressure in the accumulator chamber 3a on the upper surface side of the striking piston 7 is increased. The striking piston 7 moves downward due to the increased gas pressure in the accumulator chamber 3a. The driver 11 strikes the driving tool n by the downward movement of the striking piston 7. The driver return mechanism 20 stores driving energy (thrust due to the gas pressure in the accumulator chamber 3a) by moving the driver 11 upward. That is, the driver return mechanism 20 constitutes a drive mechanism for the driving tool 1. A damper 3b for absorbing the impact at the lower moving end of the striking piston 7 is arranged in the lower part of the cylinder 3.

As shown in FIG. 2, the driver 11 has a rack 12 composed of a plurality of meshing teeth 12a. The meshing teeth 12a are arranged at equal pitches along the longitudinal direction (vertical direction) of the rack 12. The meshing teeth 12a are meshed with the outer peripheral teeth 32a of the pinion 32, which will be described later. The lowermost meshing tooth 12a is provided at a position where the driver 11 meshes with the outer peripheral tooth 32a when the driver 11 is located at the top dead center, or below it. The uppermost meshing tooth 12a is provided at a position where the driver 11 meshes with the outer peripheral tooth 32a when the driver 11 is located at the bottom dead center, or above it. In other words, the rack 12 is always in mesh with the pinion 32 regardless of where the driver 11 is located from top dead center to bottom dead center. By rotating the pinion 32 in the winding direction (counterclockwise in FIG. 2), the meshing position with respect to the rack 12 changes and the driver 11 is moved upward.

As shown in FIG. 2, the driver 11 has a detected piece 13 on a side surface above the tip 11a. The detected piece 13 is, for example, a magnet. A standby position detection sensor 46 and a top dead center detection sensor 47 are provided on the inner peripheral surface of the driving passage 5a facing the detected piece 13. The standby position detection sensor 46 is provided so as to be at the same height as the detected piece 13 when the driver 11 is positioned at the standby position in the driving standby state. The top dead center detection sensor 47 is provided so as to be at the same height as the detected piece 13 when the driver 11 is located at the top dead center immediately before driving. The standby position detection sensor 46 and the top dead center detection sensor 47 detect the detected piece 13 when the detected piece 13 comes to the same height, and transmit a detection signal to the controller 45 described later.

As shown in FIG. 1, the driver return mechanism 20 includes an electric motor 21, a reduction gear train 22, and an intermediate shaft 23. The electric motor 21 is started by using the electric power of the battery pack 9 as a power source. The electric motor 21 is activated by pulling the switch lever 8. The rotational output of the electric motor 21 is decelerated by the reduction gear train 22 composed of the planetary gear trains of two rows and output to the intermediate shaft 23. The electric motor 21 is housed in a cylindrical motor case 21a. The reduction gear row 22 is also housed in a cylindrical gear case 22a. A motor case 21a is coaxially coupled to the end of the gear case 22a. The intermediate shaft 23 protrudes from the end of the gear case 22a on the opposite side of the motor case 21a and is housed in the mechanism case 31, which will be described later. A pinion gear 23a is provided at the end of the intermediate shaft 23.

As shown in FIGS. 2 and 3, the driver return mechanism 20 includes a clutch mechanism 30. The clutch mechanism 30 includes a cylindrical mechanism case 31. The mechanism case 31 is held in the holding case 5c of the driving nose portion 5. A gear case 22a is coupled to the end of the mechanism case 31.

As shown in FIG. 4, the clutch mechanism 30 has a pinion 32, a clutch 33, and a spindle 35. The pinion 32, the clutch 33, and the spindle 35 are arranged coaxially on the rotation axis J, respectively. The pinion 32 has a substantially disk shape centered on the rotation axis J. The pinion 32 has a plurality of outer peripheral teeth 32a over the entire circumference of the outer peripheral surface. The outer peripheral teeth 32a are arranged at equal pitches along the outer peripheral surface of the pinion 32.

As shown in FIG. 4, the pinion 32 is arranged adjacent to the clutch 33. The pinion 32 has a plurality of meshing teeth 32b arranged along the circumferential direction on the end surface (left end surface in the drawing) facing the clutch 33. The meshing tooth 32b has an upright surface 32c and an inclined surface 32d. The upright surface 32c extends substantially along the radial direction of the pinion 32 and the direction of the rotation axis J. The inclined surface 32d is gently inclined along the circumferential direction of the pinion 32 so as to extend toward the clutch 33 side in the direction opposite to the winding direction of the pinion 32. The meshing teeth 32b are formed in a chevron shape by the inclined surface 32d and the upright surface 32c, and generally protrude toward the clutch 33. An insertion hole 32e penetrating in the rotation axis J direction is provided at the center of the pinion 32.

As shown in FIG. 4, the clutch 33 has a substantially cylindrical shape centered on the rotation axis J of the pinion 32. The clutch 33 has a plurality of meshing teeth 33a arranged along the circumferential direction on an end surface (right end surface in the drawing) facing the pinion 32. The meshing tooth 33a has an upright surface 33b and an inclined surface 33c. The upright surface 33b extends substantially along the radial direction of the clutch 33 and the direction of the rotation axis J. The inclined surface 33c is gently inclined along the circumferential direction of the clutch 33 so as to extend toward the pinion 32 side toward the winding direction of the pinion 32. The meshing teeth 33a are formed in a chevron shape by the upright surface 33b and the inclined surface 33c, and generally project toward the pinion 32.

The pinion 32 and the clutch 33 are engaged with each other by engaging the meshing teeth 32b and the meshing teeth 33a with each other. The pinion 32 and the clutch 33 are strongly engaged mainly when the upright surface 32c and the upright surface 33b are engaged so as to be pressed against each other. Therefore, for example, when the clutch 33 rotates in the winding direction, the upright surface 32c and the upright surface 33b are pressed against each other. As a result, the pinion 32 is integrally engaged with the clutch 33 to rotate, and the rotational force of the clutch 33 is suitably transmitted to the pinion 32.

Further, when the pinion 32 and the clutch 33 are separated from each other in the rotation axis J direction, they are displaced along the upright surface 32c and the upright surface 33b. Both the upright surface 32c and the upright surface 33b extend in the direction of the rotation axis J. Therefore, when the pinion 32 and the clutch 33 are separated from each other in the rotation axis J direction, the engagement between the meshing teeth 32b and the meshing teeth 33a can be smoothly released.

As shown in FIG. 4, the clutch 33 has a peripheral recess 33d on a side (left side in the drawing) away from the pinion 32 from the meshing teeth 33a. The peripheral recess 33d is recessed between two disc surfaces so as to be sandwiched in the rotation axis J direction. The peripheral recess 33d is formed over the entire circumference along the circumferential direction of the clutch 33. The clutch 33 has a reduction gear 33e on the peripheral surface of the end opposite to the meshing teeth 33a. The reduction gear 33e meshes with the pinion gear 23a of the intermediate shaft 23 shown in FIG. 3 to decelerate and transmit the output of the electric motor 21. The clutch 33 is formed as a spring receiving portion 33f whose end surface opposite to the end surface having the meshing teeth 33a is a substantially flat surface. An insertion hole 33g penetrating in the rotation axis J direction is provided at the center of the clutch 33.

As shown in FIG. 4, the spindle 35 has a substantially cylindrical shape extending long in the rotation axis J direction of the pinion 32. The spindle 35 has a spring receiving portion 35a protruding in the radial direction at an end portion opposite to the pinion 32 (left side in the drawing). A compression spring 34 is provided between the spring receiving portion 35a and the spring receiving portion 33f. The compression spring 34 urges the clutch 33 toward the pinion 32 side. The spindle 35 has a small diameter tip 35b on the pinion 32 side (right side in the drawing). A bearing 36 is attached to the tip 35b. The bearing 36 is arranged between the tip 35b and the inner peripheral surface of the pinion 32.

The spindle 35 shown in FIG. 3 extends in the rotation axis J direction of the pinion 32 and is supported by the mechanism case 31. The spindle 35 is arranged parallel to the intermediate shaft 23 and below the intermediate shaft 23. The spindle 35 is inserted into the insertion hole 32e and the insertion hole 33g. The pinion 32 can rotate about the rotation axis J with respect to the spindle 35 via the bearing 36. The clutch 33 is supported by the spindle 35 so as to be rotatable around the rotation axis J and displaceable in the rotation axis J direction. With the configuration of the driver return mechanism 20 described above, as shown in FIG. 1, a power transmission path 37 in which rotational power is transmitted from the motor shaft 21b to the pinion 32 via the reduction gear train 22, the intermediate shaft 23, and the clutch 33. Is formed.

As shown in FIG. 3, the driving tool 1 has a clutch switch 40 above the driver return mechanism 20. The clutch switch 40 has a solenoid 41, a pin 42, and a bar 43. The clutch switch 40 operates the clutch 33 by supplying a current to the solenoid 41 or interrupting the current supply.

As shown in FIG. 3, the solenoid 41 is housed in a case portion 41a coupled to a side portion of the tool body 10. A plunger 42b is inserted on the inner peripheral side of the solenoid 41. The plunger 42b is arranged so as to extend substantially parallel to the rotation axis J direction of the pinion 32. A spring receiving portion 42c projecting in the radial direction is provided at the left end portion of the plunger 42b in the drawing. A compression spring 44 is provided between the end faces of the spring receiving portion 42c and the case portion 41a. The compression spring 44 urges the plunger 42b to the left in the drawing away from the solenoid 41. The plunger 42b is attracted to the solenoid 41 when a current flows through the solenoid 41. Therefore, the plunger 42b is displaced to the right in the drawing against the urging force of the compression spring 44 (see FIG. 7).

As shown in FIG. 3, a pin 42 extending substantially parallel to the rotation axis J direction of the pinion 32 is provided at the center of the plunger 42b. The pin 42 projects from the case portion 41a to the right side in the drawing. The first end 43a of the bar 43 is connected to the tip 42a of the pin 42. The bar 43 extends substantially in the vertical direction and is arranged on the side portion of the tool body 10. The bar 43 has a first end portion 43a coupled to the tip end 42a at the upper end. At the lower end of the bar 43, a second end portion 43b that is inserted into the peripheral recess 33d of the clutch 33 and engages with the clutch 33 is provided. The bar 43 has a rotating shaft portion 43c at an intermediate position between the first end portion 43a and the second end portion 43b. The bar 43 is rotatably supported by the mechanism case 31 about the rotation shaft portion 43c. The rotation shaft portion 43c is provided with a length up to the first end portion 43a longer than the length up to the second end portion 43b.

As shown in FIG. 5, the driving tool 1 has a controller 45 inside. The controller 45 is electrically connected to the battery pack 9, the electric motor 21, the solenoid 41, the standby position detection sensor 46, the top dead center detection sensor 47, and the start switch 8a described later. The controller 45 has a timer circuit 45a for counting time. The battery pack 9 supplies electric power to the electric motor 21, the solenoid 41, and the like based on the command of the controller 45. The standby position detection sensor 46 and the top dead center detection sensor 47 transmit a detection signal of the detected piece 13 (see FIG. 2) to the controller 45.

The start switch 8a shown in FIG. 5 is provided inside the switch lever 8 shown in FIG. A contact arm (not shown) that can slide up and down is provided at the tip of the driving nose portion 5. The contact arm moves upward when it comes into contact with the material to be driven. When it is detected that the contact arm has moved upward and the switch lever 8 is pulled in that state, the start switch 8a is turned on and a signal is transmitted to the controller 45. As a result, electric power is supplied from the battery pack 9 to the electric motor 21 to start the electric motor 21. When the pulling operation of the switch lever 8 is stopped, the start switch 8a is turned off and the signal is cut off. As a result, the electric motor 21 is driven until the driver 11 returns to the standby position, and then the power supply from the battery pack 9 is cut off and stopped.

Next, a series of flow of the driving operation of the driving tool 1 will be described. First, in the driving standby state shown in FIGS. 2 and 3, the detected piece 13 is located at the same height as the standby position detection sensor 46. In the driving standby state, the current flowing through the solenoid 41 is cut off. Therefore, the tip 42a of the pin 42 is located at the off position P1 drawn toward the solenoid 41. The bar 43 is in a posture extending substantially parallel to the vertical direction. At this point, the clutch 33 does not receive the urging force for moving the pinion 32 in the rotation axis J direction from the second end portion 43b. Therefore, the clutch 33 is urged toward the pinion 32 by the compression spring 34. As a result, the end face of the clutch 33 facing the pinion 32 is located at the engagement position C1. Then, the meshing teeth 33a and the meshing teeth 32b engage with each other. In this way, the power transmission path 37 is in the connected state in the driving standby state. Therefore, by activating the electric motor 21 (see FIG. 1) from the driving standby state, the pinion 32 can be immediately rotated in the winding direction. Further, in the driving standby state, the reverse rotation prevention mechanism for preventing the reverse rotation of the pinion 32 is working.

When the electric motor 21 is activated by pulling the switch lever 8 (see FIG. 1) from the driving standby state, the pinion 32 rotates in the winding direction (counterclockwise in FIG. 2). The driver 11 is further moved up from the standby position by the rotation of the pinion 32. The driver 11 moves upward, and the driver 11 and the striking piston 7 reach top dead center. When the striking piston 7 reaches the top dead center, the gas pressure in the accumulator chamber 3a is sufficiently increased. The striking piston 7 receives a downward urging force due to the gas pressure in the accumulator chamber 3a.

As shown in FIGS. 6 and 7, when the driver 11 is located at the top dead center, the top dead center detection sensor 47 and the detected piece 13 are at the same height. The controller 45 (see FIG. 5) receives the detection signal of the top dead center detection sensor 47 and passes a current through the solenoid 41. As a result, the plunger 42b and the pin 42 are attracted to the solenoid 41 and displaced to the right in FIG. 7. The tip 42a of the pin 42 is displaced to the on position P2 to the right of the off position P1 in FIG. The tip 42a pushes the first end 43a of the bar 43 to the right. The bar 43 tilts about the rotation shaft portion 43c. The length from the first end portion 43a to the rotating shaft portion 43c is longer than the length from the rotating shaft portion 43c to the second end portion 43b. Therefore, using the principle of leverage, the second end 43b is displaced to the left in FIG. 7 by a small pressing force of the tip 42a. Here, if the relationship between the length from the first end portion 43a to the rotating shaft portion 43c and the length from the second end portion 43b to the rotating shaft portion 43c is reversed, the moving amount larger than the moving amount of the tip 42a. The clutch 33 can be displaced with. By converting the force and the amount of displacement of the tip 42a moved by the solenoid 41 and transmitting the force and the amount of displacement to the clutch 33 in this way, it is possible to operate the clutch 33 with the optimum settings corresponding to various different conditions.

As shown in FIG. 7, the second end 43b displaces the clutch 33 to the left in the drawing away from the pinion 32 against the urging force of the compression spring 34. As a result, the end face of the clutch 33 facing the pinion 32 is located at the cutting position C2. Then, the meshing teeth 33a and the meshing teeth 32b are separated from each other. The power transmission path 37 is cut off, and the pinion 32 becomes freely rotatable. The pinion gear 23a of the intermediate shaft 23 is provided longer in the rotation axis J direction than the reduction gear 33e of the clutch 33. Therefore, regardless of whether the clutch 33 is located at the engaging position C1 or the disengaging position C2, the meshing state of the pinion gear 23a and the reduction gear 33e is always maintained. At this point, the activation of the electric motor 21 is continued, and the clutch 33 continues to rotate in the winding direction.

When the pinion 32 shown in FIG. 6 can rotate freely, there is no force to move the driver 11 upward due to the engagement between the pinion 32 and the rack 12. On the other hand, the driver 11 is pushed downward together with the striking piston 7 by the gas pressure in the accumulator chamber 3a. Therefore, the driver 11 instantly moves down to the bottom dead center shown in FIG. The tip 11a strikes and launches the driving tool n (see FIG. 6) in the driving passage 5a. When the driver 11 moves downward, the pinion 32 rotates in the direction opposite to the winding direction (clockwise in the figure) according to the engagement with the rack 12.

As shown in FIG. 8, when the driver 11 moves downward, the current is continuously supplied to the solenoid 41. Therefore, the tip 42a of the pin 42 is located at the on position P2 shown in FIG. The end face of the clutch 33 facing the pinion 32 is located at the cutting position C2. Therefore, the clutch 33 and the pinion 32 remain separated from each other.

When the timer circuit 45a shown in FIG. 5 counts a predetermined time, the controller 45 cuts off the current flowing through the solenoid 41. The predetermined time is the time from when the driver 11 shown in FIG. 6 starts to move downward to when it reaches the bottom dead center, launches the driving tool n, and further jumps up due to the reaction of the launching, for example, 0.1 second. When the current flowing through the solenoid 41 is cut off, the tip 42a of the pin 42 returns to the off position P1 as shown in FIG. The bar 43 is in a posture extending substantially parallel to the vertical direction, and the force of the second end portion 43b for urging the clutch 33 in the direction opposite to the pinion 32 is released. Therefore, the clutch 33 is urged to the right in the drawing by the compression spring 34. As a result, the end face of the clutch 33 facing the pinion 32 returns to the engagement position C1. The meshing tooth 33a and the meshing tooth 32b are engaged again. Even at this point, the output of the electric motor 21 is continuously transmitted to the clutch 33. Therefore, the clutch 33 and the pinion 32 rotate in the winding direction. The rotation of the pinion 32 causes the driver 11 to move upward via the rack 12.

As shown in FIG. 2, when the driver 11 moves up to the standby position, the detected piece 13 is located at the same height as the standby position detection sensor 46. The controller 45 (see FIG. 5) cuts off the power supply to the electric motor 21 when the detection signal of the standby position detection sensor 46 is received. As a result, the driver 11 stops at the standby position. This completes one cycle of the driving operation of the driving tool 1.

According to the driving tool 1 described above, the main body housing 2 is provided with a driver 11 that is vertically movable and moves downward to hit the driving tool n. A rack 12 is provided on the driver 11 to move the driver 11 upward. The pinion 32 engages with the rack 12 and rotates to move the driver 11 upward. The driving energy is stored in the driver return mechanism 20 by moving the driver 11 upward. The top dead center detection sensor 47 detects the position of the top dead center of the driver 11. The controller 45 transmits a striking signal in response to the response signal from the top dead center detection sensor 47. The clutch 33 shuts off the power transmission path 37 between the pinion 32 and the electric motor 21 in response to the striking signal.

Therefore, when the driver 11 reaches the top dead center, the force from the pinion 32 to the rack 12 is cut off. As a result, the driver 11 moves downward together with the rack 12, and the driving work is performed. Since the top dead center of the driver 11 is detected by the top dead center detection sensor 47, the reproducibility is high and the driving timing can be made accurate.

Further, the driving tool 1 has a clutch switch 40 that operates by flowing a current through the solenoid 41 in response to a striking signal. The clutch switch 40 activates the clutch 33. Therefore, by using the clutch switch 40, the start time and end time of disengagement of the clutch 33 can be easily or preferably set. As a result, wear of the clutch 33 can be suppressed.

Further, the clutch switch 40 has a pin 42 that appears and disappears due to the solenoid 41. The clutch switch 40 has a configuration in which a force or a displacement amount due to the displacement of the pin 42 is converted and transmitted to the clutch 33. Therefore, by converting the force and the amount of displacement of the pin 42 moved by the solenoid 41 and transmitting it to the clutch 33, the clutch 33 can be operated with the optimum settings corresponding to various different conditions. For example, the clutch 33 can be operated with a force larger than the force from the pin 42. Alternatively, the clutch 33 can be operated with a movement amount larger than the movement amount of the pin 42.

Further, the clutch 33 moves between the engagement position C1 which is arranged on the rotation axis J of the pinion 32 and engages with the pinion 32 along the rotation axis J, and the cutting position C2 which is separated from the pinion 32. Therefore, for example, the clutch 33 can be made relatively small. Alternatively, the clutch 33 can be switched between the engaging position C1 and the disengaging position C2 with a relatively short moving distance.

Further, the clutch 33 has meshing teeth 33a on the surface facing the pinion 32. The pinion 32 has meshing teeth 32b on the surface facing the clutch 33. Therefore, by moving the clutch 33 on the rotation axis J of the pinion 32, it is possible to switch between a state in which the meshing teeth 32b and 33a mesh with each other and a state in which the meshing teeth 32b and 33a are separated from each other.

Further, the driving tool 1 has a compression spring 34 that urges the clutch 33 toward the pinion 32. Therefore, by using the compression spring 34, the power transmission between the electric motor 21 and the pinion 32 can be maintained. That is, the clutch 33 can be held in an inactive state without using electric power.

Further, the pinion 32 has a plurality of outer peripheral teeth 32a over the entire circumference. Therefore, the pinion 32 can be made smaller in diameter. For example, a conventional driving tool pinion has a plurality of teeth in the circumferential direction and a toothless non-engagement region. The pinion 32 of this feature has a small diameter because it does not have a non-engagement region. By reducing the diameter of the pinion 32, the mechanical case 31 can also be made compact.

Further, the pinion 32 is always in mesh with the rack 12. Therefore, it is not necessary to consider the timing at which the pinion 32 and the rack 12 engage with each other and the timing at which they are disengaged. That is, since it is not necessary to consider the phase, there is a high degree of freedom in the number of outer peripheral teeth 32a and the size of the diameter of the pinion 32.

Various changes can be made to the embodiments described above. For example, a configuration in which the vertical position of the driver 11 is detected by the standby position detection sensor 46 and the top dead center detection sensor 47 is illustrated. Instead of this, for example, the controller 45 may determine the vertical position of the driver 11 by detecting the phase of the pinion 32 from the start of winding. Alternatively, for example, the controller 45 may determine the vertical position of the driver 11 based on the elapsed time from the start of winding by utilizing the fact that the rotation speed of the pinion that rotates by the output of the electric motor 21 is constant. ..

An example shows a rack 12 in which the meshing teeth 12a are arranged at an equal pitch and a pinion 32 in which the outer peripheral teeth 32a are arranged at an equal pitch. Instead, the meshing teeth 12a and the outer peripheral teeth 32a may have unequal pitches and can be freely set under conditions of constant meshing.

An example is a clutch switch 40 provided on the outside of the mechanical case 31 and utilizing the principle of leverage. Instead of this, for example, the clutch switch 40 for operating the clutch 33 may be housed in the mechanism case 31 together with the clutch mechanism 30.

Although the gas spring type driving tool 1 that uses the gas pressure of the gas sealed in the accumulator chamber 3a as the thrust for driving is illustrated, the same applies to the mechanical spring type driving tool that uses the urging force of the compression spring as the thrust. Can be done.

n ... Driving tool 1 ... Driving tool 2 ... Main body housing (housing)
3 ... Cylinder, 3a ... Accumulation chamber, 3b ... Damper 4 ... Handle part 5 ... Driving nose part, 5a ... Driving passage, 5b ... Injection port, 5c ... Holding case 6 ... Magazine 7 ... Hitting piston 8 ... Switch lever, 8a ... Start switch 9 ... Battery pack 10 ... Tool body 11 ... Driver, 11a ... Tip 12 ... Rack, 12a ... Meshing teeth 13 ... Detected piece 20 ... Driver return mechanism (drive mechanism)
21 ... electric motor, 21a ... motor case, 21b ... motor shaft 22 ... reduction gear train, 22a ... gear case 23 ... intermediate shaft, 23a ... pinion gear 30 ... clutch mechanism 31 ... mechanism case 32 ... pinion 32a ... outer peripheral teeth, 32b ... meshing Tooth, 32c ... Standing surface, 32d ... Inclined surface, 32e ... Insertion hole J ... Pinion rotation axis 33 ... Clutch, 33a ... Engaging tooth, 33b ... Standing surface, 33c ... Inclined surface 33d ... Peripheral recess, 33e ... Reduction gear, 33f ... Spring receiving part, 33g ... Insertion hole C1 ... Clutch engaging position, C2 ... Clutch disengaging position 34 ... Compression spring 35 ... Spindle, 35a ... Spring receiving part, 35b ... Tip 36 ... Bearing 37 ... Power transmission path 40 ... Clutch switch (switch)
41 ... Solenoid, 41a ... Case 42 ... Pin, 42a ... Tip, 42b ... Plunger, 42c ... Spring receiving part P1 ... Off position, P2 ... On position 43 ... Bar, 43a ... First end, 43b ... Second end Unit, 43c ... Rotating shaft portion 44 ... Compression spring 45 ... Controller, 45a ... Timer circuit 46 ... Standby position detection sensor 47 ... Top dead center detection sensor

Claims (8)

It ’s a driving tool,
A driver that is provided on the housing so that it can move up and down and hits the driving tool by moving downward.
A rack provided on the driver to move the driver upward,
A pinion that moves the driver upward by engaging with the rack and rotating,
A drive mechanism that stores driving energy by moving the driver upward,
A sensor that detects the position of the top dead center of the driver and
A controller that emits a striking signal in response to a response signal from the sensor,
A driving tool having a clutch that cuts off a power transmission path between the pinion and a motor in response to the impact signal. The driving tool according to claim 1.
A driving tool having a switch that operates by flowing an electric current through the solenoid in response to the impact signal, and the switch operates the clutch. The driving tool according to claim 2.
The switch has a pin that appears and disappears from the solenoid.
The switch is a driving tool having a configuration in which a force or a displacement amount due to a displacement of the pin is converted and transmitted to the clutch. The driving tool according to any one of claims 1 to 3.
The clutch is a driving tool that is arranged on the rotation axis of the pinion and moves between an engagement position that engages with the pinion along the rotation axis and a cutting position that is separated from the pinion. The driving tool according to claim 4.
The clutch has meshing teeth on the surface facing the pinion.
The pinion is a driving tool having meshing teeth on the surface facing the clutch. The driving tool according to claim 4 or 5.
A driving tool having a spring that urges the clutch toward the pinion. The driving tool according to any one of claims 1 to 6.
The pinion is a driving tool having a plurality of teeth over the entire circumference. The driving tool according to claim 7.
The pinion is a driving tool that is constantly engaged with the rack.

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