JP5288322B2 - Driving machine - Google Patents

Description

  The present invention relates to an impact tool, and more particularly to an electric driving machine.

Spring-driven nailing machines have already been produced in which a spring-biased plunger is pushed up against the spring-biasing force and then released to drive a nail into a material to be driven with an accelerated plunger. The plunger can be pushed up by a mechanism of a motor and a reduction gear built in the tool. Among these tools, there is a driving machine capable of selecting a mode in which one nail is driven by pulling a trigger switch for driving a motor once and a mode in which a plurality of nails are driven in succession. In such a case, in the mode in which one nail is struck each time the trigger is pulled, for example, the cycle end detection switch for detecting that the plunger has reached a predetermined position after the nail is struck once is one cycle. After the end is detected, the motor current is turned off after measuring a preset standby time with a microcomputer (see, for example, Patent Document 1).
Japanese Utility Model Publication No. 7-33575

However, if the cycle end detection switch that detects the position of the plunger or the microcomputer that measures the standby time breaks down, the timing to stop the motor is not detected. May also hit you. In this case, the nail is driven in excessively, the finish may be deteriorated, and there is a problem in terms of safety. Furthermore, the use of a microcomputer to measure the waiting time increases costs. Further, when the battery voltage changes depending on the remaining amount of the battery and the driving time varies, there is a possibility that the single driving is not reliably performed.

  Accordingly, an object of the present invention is to provide an inexpensive, small and lightweight electric driving machine capable of single operation.

  In order to achieve the above object, a driving machine according to claim 1 of the present invention includes a striking portion for striking a striking member, a motor for supplying a driving force for striking the striking portion, A trigger switch that is turned on or off based on a user instruction, an energization switch that controls energization to the motor by turning on or off based on the on or off of the trigger switch, and a time corresponding to the power supply voltage after the trigger switch is turned on Characterized in that it comprises time-counting means for turning off the energization switch after elapse of time, and a holding unit for holding the on-state or off-state of the energization switch so that the state where the energization to the motor is cut off is maintained. .

  According to such a configuration, when the user turns on the trigger switch, the energization switch is turned on, energization of the motor is started and the striking portion moves, whereby the driving material is driven. The time measuring means turns off the energization switch after a predetermined time corresponding to the power supply voltage, and interrupts the energization to the motor.

  The driving machine described in claim 2 is characterized in that, in the invention described in claim 1, the time corresponding to the power supply voltage is longer than the normal driving time for driving the driving member once.

  According to such a configuration, the time measuring means turns off the energizing switch and stops the motor after hitting the driving member once in a normal operation.

  The driving machine described in claim 3 is characterized in that, in the above invention, the time measuring means is constituted by an analog element.

  According to such a configuration, the timing means is inexpensive and simple.

  According to a fourth aspect of the present invention, in the invention of the third aspect, the timekeeping means includes a voltage comparing means using an analog element that outputs a signal corresponding to a difference between the power supply voltage and a predetermined voltage. A capacitor for accumulating electric charge according to the output of the voltage comparison means, a resistor connecting the voltage comparison means and the capacitor, and an analog for outputting a signal for turning off the energization switch when the voltage of the capacitor exceeds a predetermined voltage And a current-carrying means using an element.

  According to such a configuration, the voltage comparison means outputs a signal corresponding to the power supply voltage, and charges the capacitor with a time constant corresponding to the resistance value of the resistor and the capacitance value of the capacitor. The energization cut-off means outputs a signal for turning off the energization switch after elapse of a charging time that changes according to the power supply voltage until the capacitor becomes equal to or higher than a predetermined voltage.

  According to a fifth aspect of the present invention, in the above-described invention, the driving machine further includes a holding portion using an analog element that holds an off state of the energization switch.

  According to such a configuration, after the timing means turns off the energization switch, the off state of the energization switch is maintained.

  According to a sixth aspect of the present invention, in the invention of the fifth aspect, the driving unit is connected to the hitting projection in the first state and is disconnected from the hitting projection in the second state. And a stop switch that is turned on or off in accordance with the position of the moving unit, the drive motor supplies a driving force for movement to the moving unit, and the energizing switch turns on or off the trigger switch, and stops. It is characterized in that it is turned on or off in accordance with the on or off of the switch and the off signal of the time measuring means.

  According to such a configuration, when the moving unit reaches a predetermined position, the stop switch is turned on and the energization switch is turned off. The time measuring means outputs a signal for turning off the energization switch after a time corresponding to the battery voltage after the trigger switch is turned on. The holding unit holds the off state of the energization switch.

  The driving machine described in claim 7 is characterized in that, in the invention described in claim 6, the energizing switch is turned off by at least one of the on / off state of the stop switch and the off signal of the time measuring means. The driving machine according to claim 6.

  According to such a configuration, the stop switch and the time measuring means turn off the energizing switch regardless of the state of each other.

  According to the driving machine of the first aspect of the present invention, since the energization switch is turned off after the time corresponding to the power supply voltage, even if the time required to drive the driving member changes due to the change of the power supply voltage. The power supply to the motor can be cut off as appropriate.

  According to the driving machine of the second aspect, it is possible to avoid a malfunction in which the energization to the motor is interrupted before driving the driving member, and it is possible to perform normal driving reliably.

  According to the driving machine of the third aspect, it is possible to configure the time measuring means at a lower cost compared to the case of configuring with a digital element such as a microcomputer.

  According to the driving machine of the fourth aspect, by suitably selecting the resistance value of the resistor and the capacitance of the capacitor, the voltage of the capacitor can be increased to a predetermined voltage or more after a desired time according to the battery voltage. It becomes possible, and the energizing switch can be turned off before hitting the driving member once and hitting the second shot.

  According to the driving machine of the fifth aspect, since the holding switch holds the off state of the energization switch, it is possible to prevent an unintended driving from being performed after the energization of the motor is once interrupted.

  According to the driving machine of the sixth aspect, since the stop switch turns off the energizing switch, it is possible to reliably perform single driving even if the elements constituting the time measuring means do not operate normally.

  According to the driving machine of the seventh aspect, even when either the stop switch or the timing means does not operate normally, the single driving can be surely performed by one of the operations, and the operation of the driving machine can be prevented. Certainty can be improved.

  As described above, according to the driving machine of the present invention, even when the battery voltage changes depending on the remaining battery level and the driving time varies, or even when the stop switch or the timing means breaks down, the driving machine can reliably Therefore, it is possible to provide a small and inexpensive driving machine.

  Hereinafter, a nail driver 1 according to a first embodiment as a driving machine of the present invention will be described with reference to FIGS. First, the overall configuration of the nailing machine 1 according to the first embodiment will be described with reference to FIGS. 1 and 2. As shown in FIG. 1 and FIG. 2, the nail driver 1 includes a housing 2 that serves as an outer shell, a handle 3, a battery 4, a nose 5 provided on the front end side in the driving direction of the housing 2, and a magazine 6. And mainly includes a controller 100 therein.

  The handle 3 extends from the surface of the housing 2, and a trigger 10 for controlling the operation of the motor 7 is provided at the upper left boundary in FIGS. 1 and 2. A trigger switch 24 is provided in the handle 3 so as to operate adjacent to and in conjunction with the trigger 10.

The magazine 6 is provided across the nose 5 and the tip portion of the housing 2. A plurality of nails 23 as driving members are built in a bundle in the magazine 6, and the nails are supplied into a passage (not shown) of the nose 5. The distance of the passage in the nose 5 is ensured to be larger than the nail length, and constitutes a running section for accelerating the plunger 8 until the nail contacts the driven member. Further, there is a nail remaining amount sensor 26 (not shown) for detecting the remaining amount of nail in the magazine 6.

  The housing 2 includes a motor 7, a plunger 8, a spring 9, a planetary gear 11, a drum 13, a first roller 15, a second roller 14, a wire 16, and the like.

The plunger 8 is disposed so as to be movable between the top dead center side and the bottom dead center side of the housing 2 as a hitting projection . The plunger 8 has a blade 8 a, and the tip of the blade 8 a extends to a passage position defined in the nose 5. Further, a disc-shaped plunger plate 8b is installed on the top dead center side of the end portion of the plunger 8, and its substantially center is connected to the top dead center side tip of the blade 8a.

  The spring 9 is installed between the plunger plate 8b and the left end of the housing 2 in FIG. The motor 7 is provided with a rotating shaft (not shown), and rotates by the electric power supplied from the battery 4 to supply the planetary gear 11 with a rotating force. The planetary gear 11 includes an engaging portion (not shown) and an output shaft 19 (see FIGS. 3A to 3C). The engaging portion is engaged with the rotating shaft of the motor 7 and amplifies the rotational force of the motor 7 and outputs it from the output shaft 19. Thus, since the torque of the motor 7 can be amplified by the planetary gear 11, the small motor 7 is used for the compression mechanism of the spring 9.

  The drum 13 rotates based on the operation of a compression release mechanism (clutch mechanism) described later by the rotational force supplied from the motor 7 via the planetary gear 11. The wire 16 connects the drum 13 and the plate 8 b of the plunger 8 via the first roller 15 and the second roller 14. The wire 16 is a bundle of a plurality of metal wires, and has both flexibility and strength. Further, in order to prevent wear due to contact with the first roller 15 and the second roller 14, the surface of the wire 16 is coated with resin.

  The battery 4 is connected to the connection terminal A (see FIG. 5) of the nailing machine 1 and supplies power to the motor 7 via the controller 100 through a wiring (not shown) arranged in the handle 3. In the present embodiment, the potential of the negative terminal of the battery 4 is set to the GND potential.

  With such a configuration, the nail 23 arranged on the injection path in the nose 5 in the state shown in FIG. 2 (the state where the plunger 8 is located at the top dead center) is in the state shown in FIG. In a state of being positioned at a position), the blade 8a is pushed out from the right end of the nose 5 and driven into the driven member. Further, since the nail driver 1 according to the first embodiment employs a pushless mechanism that does not require the nose 5 to be pressed against the driven member when the nail 23 is driven, it is driven by pressing the nose 5. It is possible to prevent the member from being damaged.

  Next, the structure of the clutch that serves as a compression release mechanism for the spring 9 will be described with reference to the developed views of FIGS. 3 (a) to 3 (c). The compression release mechanism of the spring 9 is configured to include the output shaft 19 of the planetary gear 11, the guide plate 18, the pin support plate 21, the drum hook 22, the drum 13, the power transmission pin 17, the drum 13, and the wire 16.

  The output shaft 19 has a key 20 on its side surface. The guide plate 18 has a guide groove 18a, a guide protrusion 18b, and a through hole 18c. The through hole 18c is formed substantially at the center of the guide plate 18, and the output shaft 19 is inserted therethrough. The guide groove 18a is formed adjacent to the through hole 18c, and the guide protrusion 18b is formed around the through hole 18c so that the distance from the through hole 18c to the guide groove 18a is increased in a part. Yes. Specifically, the guide protrusion 18b has a shape that is expanded about 5 to 15 mm in the radial direction from the center of the through hole 18c.

  The pin support plate 21 is formed with a through hole having a key groove 21b in the main body portion, and an extending portion having a pin support slide portion 21a extends from the main body portion. The key groove 21b is engaged with the key 20 of the output shaft 19 inserted through the through hole.

  The power transmission pin 17 includes a guide groove contact portion 17a and a pin contact portion 17b. The guide groove contact portion 17 a can be engaged with the guide groove 18 a of the guide plate 18. Therefore, the moving direction and moving amount of the power transmission pin 17 are controlled by the shape of the guide groove 18a. The pin contact portion 17b has the same height as a hook portion 22a of a drum hook 22 described later in a state where the compression release mechanism is combined. The right side surface in FIG. 3C of the pin contact portion 17 b of the power transmission pin 17 is slidably supported by the pin support slide portion 21 a of the pin support plate 21.

  With such a configuration, the pin support plate 21 and the power transmission pin 17 always rotate in synchronization with the output shaft 19.

  The drum hook 22 includes a cylindrical main body portion 22c and a hook portion 22a extending from the side surface of the main body portion 22c. The bearing 22b is disposed so as to contact the inner peripheral surface of the main body 22c. Since the output shaft 19 is inserted into the drum hook 22 via the bearing 22b, the output shaft 19 and the drum hook 22 do not necessarily rotate in synchronization. The hook portion 22 a extends from the main body portion 22 c in a direction substantially perpendicular to the output shaft 19, and can contact the pin contact portion 17 b of the power transmission pin 17. Accordingly, the power transmission pin 17 always rotates in synchronization with the pin support plate 21. However, the drum hook 22 is only in the case where the pin contact portion 17b of the power transmission pin 17 contacts the hook portion 22a. It rotates in synchronization with the support plate 21 and the power transmission pin 17.

  The drum 13 has an annular shape. The body portion 22c of the drum hook 22 is press-fitted into the through hole formed at the approximate center of the drum 13. Thereby, the drum 13 and the drum hook 22 rotate in synchronization. The damper collision portion 13 a is provided so as to protrude from the drum 13 in the axial direction of the output shaft 19.

  The wire 16 is disposed so as to be able to be wound around the side surface of the drum 13, and connects the drum 13 and the plunger 8 (see FIG. 1), and is wound around the side surface according to the rotation of the drum 13. The plunger 8 is moved.

  Next, the operation at the time of nailing will be described with reference to FIGS. 4A to 4D which are operation diagrams of the spring compression release mechanism. When the operator pulls the trigger 10, electric power is supplied from the battery 4 to the motor 7 by the trigger switch 24 and the controller 100, and the motor 7 rotates. The rotational force is transmitted to the pin support plate 21 and the power transmission pin 17 via the planetary gear 11 and the output shaft 19.

  The initial state of the spring compression release mechanism is shown in FIG. 4A. When the pin contact portion 17b and the hook portion 22a contact each other, the power transmission pin 17 and the drum hook 22 are engaged and moved simultaneously. It has become. Therefore, the pin support plate 21 rotates and the drum hook 22 and the drum 13 also rotate.

  FIG. 4B shows a state in which the pin support plate 21 is rotated about 135 degrees counterclockwise from the state of FIG. In synchronization with the rotation of the pin support plate 21, the drum 13 is also rotated 135 degrees, and one end of the wire 16 is wound around the side surface. When the wire 16 is wound, the plunger 8 connected to the other end of the wire 16 is pulled and moved toward the top dead center, and the plunger plate 8b provided at the end of the plunger 8 compresses the spring 9.

  As the pin support plate 21 rotates from FIG. 4B to FIG. 4C, the guide protrusion 18b installed in the guide groove 18a and the end of the power transmission pin 17 come into contact with each other. The guide protrusion 18b has a shape that swells about 5 to 15 mm in the radial direction from the center of the rotation axis. As the pin support plate 21 rotates, the power transmission pin 17 follows the shape of the guide protrusion 18b and supports the pin. It moves radially outward along the slide portion 21a.

  When the pin support plate 21, that is, the drum 13 is rotated about 270 degrees from the state shown in FIG. 4A to the state shown in FIG. 4C, the plunger 8 moves to the top dead center, and the spring 9 is compressed most. It becomes a state. At the same time, the power transmission pin 17 moves about 5 to 15 mm radially outward, and the engagement between the power transmission pin 17 and the hook portion 22a is released.

  When the engagement between the power transmission pin 17 and the hook portion 22a is released, the compressed spring 9 is released and the plunger 8 moves to the bottom dead center side. When the plunger 8 moves to the bottom dead center side, the drum 13 and the drum hook 22 start to rotate in reverse by being pulled by the wire 16. (Fig. 4 (d))

  When the plunger 8 reaches the bottom dead center by the opening force of the compressed spring 9, the nail 23 in the passage (not shown) of the nose 5 is pushed out from the tip of the nose 5 by the blade 8a and driven into the material to be driven. . When the drum 13 returns to the initial state, the damper collision portion 13a engages with a drum damper (not shown) fixed in the housing 2, and the drum 13 and the drum hook 22 are fixed at the initial position.

  Next, the controller 100 will be described with reference to FIG. 5 which is a circuit diagram and FIG. 6 which is an operation time chart. The controller 100 has a timekeeping function and a holding function for preventing continuous driving with the trigger 10 pulled once, and a connection terminal of the nailing machine 1 with the trigger 10 pulled. It has a detection / shut-off function to prevent driving when it is connected to A.

  First, a circuit configuration relating to the clocking function and the holding function will be described with reference to the circuit diagram of FIG. The controller 100 includes an FET 101 that is an energization switch, and a PNP transistor 110 and an NPN transistor 111 that are holding units. In this embodiment, an Nch FET is used as the FET 101.

  The FET 101 is connected in series with the battery 4, the trigger switch 24, and the motor 7. A diode 104 that suppresses the generation of flyback voltage is connected between both terminals of the motor 7. A resistor 103 is connected between the gate and source of the FET 101. A resistor 102 is further connected to the gate of the FET 101.

  A smoothing circuit including a resistor 105 and a capacitor 106 is connected to the high-voltage side terminal of the motor 7, and the output side of the smoothing circuit is connected to the gate terminal of the FET 101 via the resistor 107 and the resistor 102. . Thus, when the trigger switch 24 is turned on, a smooth voltage is applied to the gate terminal of the FET 101, so that the FET 101 is also turned on and a current flows through the motor 7.

  A nail remaining amount switch 26 is connected in parallel with the FET 101 between the output-side terminal of the resistor 107 and the negative terminal of the battery 4. The nail remaining amount switch 26 is turned on when the remaining amount of the nail 23 becomes a predetermined value or less. When the nail remaining amount switch 26 is turned on, the FET 101 is turned off because the gate potential of the FET 101 becomes the GND potential. In this way, the nail driver 1 is prevented from operating when the remaining amount of the nail 23 falls below a predetermined value.

  The output side of the smoothing circuit is also connected to the emitter of the PNP transistor 110. A resistor 109 is connected between the base and emitter of the PNP transistor 110. Further, the base of the PNP transistor 110 is connected to the collector of the NPN transistor 111 via the resistor 108, and the collector of the PNP transistor 110 is connected to the base of the NPN transistor 111 via the resistor 113. A resistor 112 and a capacitor 114 are connected in parallel between the base and emitter of the NPN transistor 111. The emitter of the NPN transistor 111 is further connected to the negative terminal of the battery 4. The collector of the NPN transistor 111 is connected to the gate terminal of the FET 101 via the resistor 102.

  Further, a resistor 136 and a constant voltage diode 137 are connected in series on the output side of the smoothing circuit. A connection point between the resistor 136 and the constant voltage diode 137 is connected via a resistor 138 to the negative input terminal of the operational amplifier 133 which is the center of the voltage comparison means for realizing the time measuring function. A resistor 134 and a resistor 135 are connected in series to the plus terminal and the minus terminal of the battery 4. The connection point of the resistor 134 and the resistor 135 is connected to the plus terminal of the operational amplifier 133 via the resistor 140. Further, it is connected to the negative terminal of the battery 4 through the resistor 141. The output terminal of the operational amplifier 133 is connected to the negative terminal via the resistor 139 to form a negative feedback. That is, the operational amplifier 133 and the resistors 138, 139, 140, and 141 form a general differential amplifier circuit. The negative input voltage of the differential amplifier circuit is a voltage determined by the constant voltage diode 137, the positive input voltage of the differential amplifier circuit is a voltage obtained by dividing the battery voltage by the resistors 134 and 135, and the output voltage of the operational amplifier 133 Is a voltage corresponding to the difference between the negative input voltage and the positive input voltage.

  The output terminal of the operational amplifier 133 is also connected to the negative terminal of the operational amplifier 143 via the diode 142 and the resistor 144. The operational amplifier 143 is a main configuration of the energization cutoff unit that realizes a timekeeping function. The negative terminal of the operational amplifier 143 is connected to the negative terminal of the battery 4 via the capacitor 145. The positive terminal of the operational amplifier 143 is applied with a voltage obtained by dividing the output voltage of the smoothing circuit obtained by smoothing the output of the battery 4 by the resistor 146 and the resistor 147. Further, the positive input terminal is connected to the output terminal via a resistor 148 and a diode 149, and constitutes a Schmitt trigger circuit for positive feedback. A capacitor 145 that is charged via a resistor 144 is connected to the negative input terminal. The output terminal of the operational amplifier 143 is connected to the gate resistor 102 of the FET 101 via the diode 150. Although not shown, a smoothing voltage is applied as a power source for the operational amplifiers 133 and 143.

  Next, the holding function and the time measuring function of the controller 100 configured as described above will be described with reference to FIGS. 5 and 6. FIG. 6 shows a time chart for explaining the operation.

  First, when the trigger switch 24 is turned on (FIG. 6, t0), a smoothing potential smoothed by the resistor 105 and the capacitor 106 is applied to the gate terminal of the FET 101 via the resistor 107 and the resistor 102. Therefore, the FET 101 is turned on and a current flows through the motor 7. Thereby, the motor 7 rotates and the drum 13 also starts rotating. In order to prevent the PNP transistor 110 from being turned on only by turning on the trigger switch 24, the resistor 103 has a value sufficiently larger than the resistors 108 and 109 (about 10 times in this embodiment). Yes. That is, even if the trigger switch 24 is turned on and a smooth voltage is applied, no current flows through the base of the NPN transistor 111 until the capacitor 114 is charged, so the NPN transistor 111 is not turned on, and the base of the PNP transistor 110 -Since no current flows between the emitters, the PNP transistor 110 is not turned on. In this state, the collector of the PNP transistor 110 has the same potential as the negative terminal of the battery 4, and the collector of the NPN transistor 111 has the same potential as the smoothing voltage. That is, a voltage close to the smoothing voltage is applied to the gate of the FET 101, and the FET 101 is turned on. That is, when the trigger switch 24 is turned on (FIG. 6, t0), a voltage is applied to the gate of the FET 101 and the FET 101 is turned on.

  When the motor 7 rotates and the rotation angle of the drum 13 reaches about 270 degrees (FIG. 6, t1), the contact between the pin contact portion 17b of the power transmission pin 17 and the hook portion 22a of the drum hook 22 is released, The drum 13 starts to rotate in reverse by the urging force of the spring 9 and returns to 0 degrees. At this time, the plunger 8 moves from the top dead center toward the bottom dead center, pushes out the nail 23 arranged in the injection path in the nose 5 to the outside by the blade 8b, and drives it into the workpiece.

  On the other hand, as described above, the operational amplifier 133 receives a predetermined constant voltage corresponding to the constant voltage diode 137 at the negative terminal, and a voltage obtained by dividing the voltage of the battery 4 by the resistors 134 and 135 at the positive terminal. The differential amplifier is formed. Therefore, when the operational amplifier 133 turns on the trigger switch 24 (FIG. 6, t0), the operational amplifier 133 outputs a value obtained by amplifying the difference between the voltage of the battery 4 and a predetermined constant voltage. This output charges the capacitor 145 through the diode 142 and the resistor 144, and this charging voltage is input to the negative terminal of the operational amplifier 143 (FIG. 6, t0 to t2). At this time, the charging time of the capacitor 145 depends on a time constant corresponding to the product of the resistance value of the resistor 144 and the capacitance of the capacitor 145. As described above, the operational amplifier 133 corrects the time from when the trigger 10 is operated to when the energization switch 101 is turned off (hereinafter referred to as the cutoff standby time) based on the voltage of the battery 4 and a predetermined voltage. A signal corresponding to the difference from the voltage is output.

  The positive terminal voltage of the operational amplifier 143 is a value obtained by dividing the voltage obtained by smoothing the output from the battery 4 by the above-described smoothing circuit by the resistor 146 and the resistor 147. Until the capacitor 145 is charged, the input voltage at the positive input terminal is higher than the input voltage at the negative input terminal, so the output terminal of the operational amplifier 143 outputs high (FIG. 6, t0 to t2). The output voltage is then blocked by diodes 149 and 150.

  When the voltage of the capacitor 145, that is, the input voltage of the negative input terminal becomes equal to the input voltage of the positive input terminal (FIG. 6, t2), the output voltage of the operational amplifier switches to low and outputs 0V. As a result, the gate voltage of the FET 101 is reduced to 0 V via the diode 150 and the gate resistor 102, and the FET 101 is turned off to cut off the current of the motor 7. Furthermore, in order not to make the output of the operational amplifier 143 unstable via the diode 149 and the resistor 148, the voltage at the positive input terminal of the operational amplifier 143 is also lowered (FIG. 6, t3), so that it does not become a high output again. . Thereafter, the motor 7 stops after rotating due to inertia (t3 in FIG. 6).

  If the trigger switch 24 is turned off (FIG. 6, t4), the PNP transistor 110 is turned off, so that the hold of the FET 101 in the off state can be released. Then, when the trigger switch 24 is turned on again, the FET 101 can be turned on and the motor 7 can be started.

  The time until the output terminal of the operational amplifier 143 changes from high to low, that is, the cutoff standby time (t2 in FIG. 6) is the voltage dividing ratio between the resistor 146 and the resistor 147, the capacitance of the capacitor 145, and the resistance value of the resistor 144. And the output voltage of the operational amplifier 133. Therefore, by setting the blocking standby time longer than the normal driving time, one nail can be driven reliably for one trigger operation. Further, by setting the time until the motor 7 stops before the second shot starts, unintentional driving is prevented.

  FIG. 7 shows the relationship between the remaining battery level of the battery 4, the battery voltage, and the driving time. The horizontal axis represents the ratio of the remaining battery level to the battery voltage of the battery 4 when fully charged, and the vertical axis represents the battery voltage and the driving time for driving one nail. As shown in FIG. 7, since the battery voltage decreases as the remaining battery level decreases, the motor speed decreases and the driving time increases with the decrease. The driving time when the remaining battery level is low is nearly twice as long as the driving time when fully charged. Therefore, when the interruption waiting time from when the trigger 10 is operated to when the power supply to the motor 7 is stopped is made constant, two shots may be shot continuously or stopped before the first shot is shot. is there.

  Thus, as described above, the operation output voltage of the battery voltage by the operational amplifier 133 is used as the charging voltage of the RC charging circuit by the resistor 144 and the capacitor 145 to correct the cut-off waiting time, so that the battery voltage is fully charged. When the battery voltage is high, the set time is shortened, and when the remaining battery level is low, that is, when the battery voltage is low, the set time is lengthened.

  Next, the detection / shut-off function of the controller 100 will be described. The controller 100 further includes a PNP transistor 125 and an NPN transistor 130 which are detection / shut-off units.

  The emitter of the PNP transistor 125 is connected to the positive terminal of the battery 4 via the diode 124, and the base of the PNP transistor 125 is connected to the negative terminal of the battery 4 via the resistor 127 and the resistor 129. A capacitor 128 is connected in parallel to the resistor 129. The resistor 129 is set to a sufficiently large value (100 times in this embodiment) as compared with the resistors 126 and 127. A resistor 126 is connected between the base and emitter of the PNP transistor 125. The collector of the PNP transistor 125 is connected to the base of the NPN transistor 130 via the resistor 132.

  The emitter of the NPN transistor 130 is connected to the negative terminal of the battery 4. A resistor 131 is connected between the base and emitter of the NPN transistor 130. Further, the collector of the NPN transistor 130 is connected to the gate of the FET 101 via the resistor 102.

  Next, the operation of the detection / shut-off function of the controller 100 having such a configuration will be described with reference to FIGS. FIG. 8 is a time chart of the operation of the controller 100 for the detection / shut-off function when the battery 4 is connected to the connection terminal A of the nailing machine 1 with the trigger switch 24 turned on. FIG. 9 is a time chart of the operation of the controller 100 for the detection / shut-off function when the trigger switch 24 is turned on after the battery 4 is connected to the connection terminal A of the nailing machine 1.

  When the battery 4 is connected to the connection terminal A (FIG. 8, t11) with the trigger switch 24 turned on (FIG. 8, t10), the PNP transistor 125 is turned on, and at the same time, the capacitor 128 via the resistors 126 and 127. Is charged. Even if the battery 4 is connected to the connection terminal A with the trigger switch 24 turned on, the trigger switch 24 may be turned on almost simultaneously with the connection of the battery 4 to the connection terminal A.

  When the PNP transistor 125 is turned on, a current flows to the base of the NPN transistor 130, and the NPN transistor 130 is turned on. When the NPN transistor 130 is turned on, the potential of the FET 101 connected to the collector of the NPN transistor 130 also becomes the GND potential, so that the smoothing voltage is not applied to the gate of the FET 101. Therefore, the FET 101 remains off and the nail driver 1 does not operate. At this time, the PNP transistor 110 is turned on when the output side of the resistor 108 becomes the GND potential. Then, the capacitor 114 is charged through the resistor 113, and the NPN transistor 111 is also turned on.

  Here, as described above, since the resistor 129 is set to a larger value than the resistors 126 and 127, when the charging of the capacitor 128 is completed, the PNP transistor 125 is interposed between the base and the emitter of the PNP transistor 125. Does not generate a potential difference that turns on the PNP transistor 125, and the PNP transistor 125 is turned off (t12 in FIG. 8). Then, the NPN transistor 130 is also turned off, and a smoothing voltage can be applied to the gate of the FET 101.

  However, in this case as well, the PNP transistor 110 and the NPN transistor 111 continue to be on, and the FET 101 is kept off. Therefore, even if the NPN transistor 130 is turned off, the FET 101 is off unless the trigger switch 24 is turned off. Is not released.

  On the other hand, after the battery 4 is connected to the connection terminal A (FIG. 9, t20), when the trigger switch 24 is turned on after a predetermined time has elapsed (FIG. 9, t22), the capacitor 128 completes charging, and the above-mentioned Thus, since the PNP transistor 125 is off (FIG. 8, t21), the NPN transistor 130 is also not on, and the FET 101 is in a state where a smooth voltage can be applied, and the nail operation can be performed normally. it can.

  With such a configuration, when the battery 10 is connected to the connection terminal A with the trigger 10 pulled, that is, with the trigger switch 24 turned on, the FET 101 is not turned on. 1 can be prevented from operating.

  As described above in detail, according to the nail driver 1 according to the first embodiment, when the user pulls the trigger 10, the nail 23 is driven into the driven material from the tip of the nose 5. After driving the nail 23, the FET 101 is turned off after the shut-off waiting time when the voltage of the capacitor 145 charged in accordance with the voltage of the battery 4 becomes a predetermined value or more, and the drive of the motor 7 is stopped. Therefore, the nail 23 can be driven into the driving material in a single shot.

  When the battery 4 is connected with the trigger switch 24 turned on, the FET 101 is not turned on due to the off signal of the NPN transistor 130 and the holding function of the PNP transistor 110 and the NPN transistor 111. It is not included.

  Therefore, it is possible to reduce the finishing defect caused by driving a plurality of nails 23 in the same place, the risk of an accident caused by unintended driving, and the like, and the operation reliability can be increased. Furthermore, since an expensive circuit such as a special mechanism or a microcomputer is not required with the above configuration, the small nailing machine 1 can be manufactured easily and inexpensively.

  Next, a nail driver 50 according to a second embodiment will be described with reference to FIGS. The nail driver 50 according to the second embodiment has a stop switch 25 that is not included in the nail driver 1 according to the first embodiment and has a controller configuration that is different from that of the nail driver 1 according to the first embodiment. Most configurations are the same. Therefore, the same component number is attached | subjected about the same structure, and detailed description is abbreviate | omitted.

  As shown in FIG. 10, the stop switch 25 which is the main configuration of the stop function in the nailing machine 50 according to the second embodiment is provided in the vicinity of the drum 13. The stop switch 25 is turned on / off with the rotation of the drum 13, and the controller 200 controls the supply of electric power to the motor 7 based on the on / off of the stop switch 25.

  Specifically, as shown in FIG. 12, the stop switch 25 is off in the initial state (t0), and is turned on by the damper collision portion 13c when the drum 13 rotates about 240 degrees from the initial state (t1 ′). , Designed to remain on until about 270 degrees (t1). When the contact between the pin contact portion 17b of the power transmission pin 17 and the hook portion 22a of the drum hook 22 is released at about 270 degrees and the drum 13 returns to about 240 degrees, the stop switch 25 is turned off again. Become.

  It should be noted that the stop switch 25 may be turned on / off as long as the drum 13 is rotated without depending on the damper collision portion 13c. For example, the extending part of the pin support plate 21 may be used.

  The controller 200 according to the second embodiment has a stop function by a stop switch in addition to the timekeeping function, the holding function, and the detection / shut-off function of the controller 100 according to the first embodiment. First, the circuit configuration of the stop function of the controller 200 will be described with reference to FIG.

  As shown in FIG. 11, one end of the stop switch 25 is connected to a smoothing circuit composed of a resistor 105 and a capacitor 106, and a smoothing voltage is applied thereto. The other end of the stop switch 25 is connected to the negative terminal of the battery 4 via the resistor 122. Further, a backflow prevention diode 118, a current limiting resistor 119, and a capacitor 121 are connected in series between the other end of the stop switch 25 and the negative terminal of the battery 4. The output side of the resistor 119 is further connected to the emitter of the PNP transistor 115. A resistor 116 is connected between the base and emitter of the PNP transistor 115, and the base of the PNP transistor 115 is further connected to the other end of the stop switch 25 via a resistor 117 and a diode 120. The collector of the PNP transistor 115 is connected to the collector of the PNP transistor 110.

  Next, the operation of the stop function of the controller 200 having such a configuration will be described with reference to FIGS. FIG. 12 is a time chart of the operation of the controller 200 including the stop function.

  First, when the trigger switch 24 is turned on (FIG. 12, t0), a smooth potential is applied to the gate of the FET 101, so that the FET 101 is turned on and a current flows through the motor 7. Thereby, the motor 7 rotates and the drum 13 also starts rotating. As described in the first embodiment, the PNP transistor 110 is not turned on only when the trigger switch 24 is turned on.

  When the motor 7 rotates and the rotation angle of the drum 13 reaches about 240 degrees (FIG. 12, t1 '), the stop switch 25 is turned on as described above. When the stop switch 25 is turned on, the capacitor 121 is charged. When the rotation angle of the drum 13 reaches about 270 degrees (FIG. 6, t1), the contact between the pin contact portion 17b of the power transmission pin 17 and the hook portion 22a of the drum hook 22 is released, and the spring 9 is attached. The drum 13 starts reverse rotation by the force.

  While the stop switch 25 is on, the emitter potential of the PNP transistor 115 is lower than the cathode potential of the diode 120, and no potential difference is generated between the base and emitter of the PNP transistor 115 to turn on the PNP transistor 115. 115 remains off.

  The drum 13 then returns to 0 degrees by reverse rotation. That is, since the rotation angle of the drum 13 is less than 240 degrees, the stop switch 25 is turned off again (FIG. 6, t1). When the stop switch 25 is turned off, the base of the PNP transistor 115 is connected to the GND potential via the resistor 117, the diode 120, and the resistor 122, and therefore, between the emitter of the PNP transistor 115 connected to the charged capacitor 121. A potential difference occurs in As a result, the PNP transistor 115 is turned on, and the charge accumulated in the capacitor 121 flows into the capacitor 114 via the resistor 113.

  At this time, the potential at the base of the NPN transistor 111 rises and the NPN transistor 111 is turned on. When the NPN transistor 111 is turned on, the potential of the gate of the FET 101 becomes the GND potential, so that the FET 101 is turned off and no current flows through the motor 7. Thus, when the stop switch 25 is turned off again, the drive of the motor 7 is stopped (FIG. 12, t2). Thereafter, the motor 7 rotates due to inertia, but then stops (FIG. 12, t3).

  Here, as described in the first embodiment, since the holding function of the PNP transistor 110 and the NPN transistor 111 operates, a smoothing voltage is applied to the base of the NPN transistor 111 as long as the trigger switch 24 is on. As a result, the NPN transistor 111 continues to be turned on. Therefore, once the NPN transistor 111 is turned on, the NPN transistor 111 can be kept in the on state, that is, the FET 101 can be kept off even if all the electric charge stored in the capacitor 121 is discharged.

  It should be noted that the time from when the stop switch 25 is turned off until the FET 101 is held off is defined by the values of the resistor 113 and the capacitor 114. In addition, it is desirable to make the capacity of the capacitor 121 larger than the capacity of the capacitor 114.

  If the trigger switch 24 is turned off (FIG. 12, t4), the PNP transistor 110 is turned off, so that the holding of the off state of the FET 101 can be released. Then, when the trigger switch 24 is turned on again, the FET 101 can be turned on and the motor 7 can be started.

  Further, the controller 200 has a clocking function similar to the controller 100 according to the first embodiment. As shown in FIG. 12, the GND voltage is supplied from the operational amplifier 143 to the gate of the FET 101 at time t2, and the FET 101 is turned off. Let

  Therefore, when the stop switch 25 cannot be pressed due to a mechanical failure or the output of the stop switch 25 is not output due to a mechanical / electrical failure of the stop switch 25, the stop function by the stop switch 25 causes the FET 101 to Although it is not turned off, the power supply to the motor 7 is stopped after a shut-off waiting time corresponding to the voltage value of the battery 4 by the time measuring function.

  By setting this shut-off waiting time longer than the normal driving time, the stop switch 25 operates faster in normal driving (FIG. 6, t1 ′), and the FET 101 is turned off as described above. Then, the driving of the motor 7 is stopped.

  As described in detail above, according to the nail driver 50 according to the second embodiment, when the plunger 8 reaches a predetermined position, the stop switch 25 is turned on and the FET 101 is turned off. After being inserted, the power supply to the motor 7 can be cut off. On the other hand, since the operational amplifier 143 outputs a signal for turning off the FET 101 after the energization cut-off time corresponding to the voltage of the battery 4 after the trigger switch 24 is turned on, the operational amplifier 143 supplies the motor 7 with a desired time according to the voltage of the battery 4. The energization can be cut off.

  That is, since the stop switch 25 and the operational amplifier 143 turn off the FET 101 by at least one of the operations regardless of the state of each other, even if one of the functions is lost due to a failure or the like, it is possible to reliably perform a single shot. Thus, the operation reliability can be improved. Further, with such a configuration, an expensive circuit such as a special mechanism or a microcomputer is not required, so that the small nailing machine 50 can be easily and inexpensively manufactured.

  As described above, according to the nailing machine of the present invention, a single operation with high reliability can be realized without providing a special mechanism. That is, a simple and inexpensive electric driving machine can be provided.

  Note that the driving machine of the present invention is not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the gist of the present invention.

  For example, in the above embodiment, the motor 7 and the trigger switch 24 are connected in series, but may be connected in parallel. According to such a configuration, since a large current flowing through the motor 7 does not flow through the trigger switch 24, the capacity of the trigger switch 24 can be reduced.

  Further, a transistor may be used instead of the FET used in the above embodiment, or an FET may be used instead of the transistor.

  Further, in the above embodiment, an operational amplifier is used as a configuration for realizing a timekeeping function, but a microcomputer may be used.

  As a mechanism for driving the plunger, the plunger 8 is moved from the top dead center to the bottom dead center using the spring 9, the drum 13, and the like. For example, the rotational energy is accumulated in the flywheel based on the rotation of the motor. Other configurations such as driving the plunger by connecting via a clutch can also be used. Further, each element of the circuit constituting the controller is not limited to the above, and any element having the same action and effect may be used.

Partial perspective side view according to the first embodiment of the present invention showing the driving machine when the plunger reaches the bottom dead center Partial perspective side view according to the first embodiment of the present invention representing the driving machine when the plunger reaches top dead center The perspective view of the spring compression release mechanism which concerns on the 1st Embodiment of this invention. The perspective view which expanded a part of spring compression release mechanism concerning a 1st embodiment of the present invention. The perspective view which fully developed the spring compression release mechanism which concerns on the 1st Embodiment of this invention. The perspective view of the spring compression release mechanism which removed the drum which concerns on the 1st Embodiment of this invention. The perspective view of the spring compression release mechanism which removed the drum which concerns on the 1st Embodiment of this invention. The perspective view of the spring compression release mechanism which removed the drum which concerns on the 1st Embodiment of this invention. The perspective view of the spring compression release mechanism which removed the drum which concerns on the 1st Embodiment of this invention. 1 is a circuit diagram of a controller according to a first embodiment of the present invention. The operation | movement time chart explaining the time measuring function of the controller concerning the 1st Embodiment of this invention. The figure explaining the relationship between the battery remaining amount, battery voltage, and driving time concerning one Embodiment of this invention. The operation | movement time chart explaining the detection and interruption | blocking function of the controller concerning the 1st Embodiment of this invention. The operation | movement time chart explaining the detection and interruption | blocking function of the controller concerning the 1st Embodiment of this invention. Partial perspective side view according to the second embodiment of the present invention showing the driving machine when the plunger reaches the bottom dead center The circuit diagram of the controller concerning the 2nd Embodiment of this invention. The operation | movement time chart explaining the stop function of the controller concerning one Embodiment of this invention.

Explanation of symbols

1: Nailer 2: Housing 3: Handle 4: Battery 5: Nose 6: Magazine 7: Motor 8: Plunger 8a: Blade 8b: Plunger plate 9: Spring 10: Trigger 11: Planetary gear 12: Drum 13: Damper collision Part 13a: 14: Second roller 15: First roller 16: Wire 17: Power transmission pin 17a: Guide groove engaging part 17b: Pin engaging part 18: Guide plate 18a: Guide groove 18b: Guide protrusion 19: Output shaft 20: Key 21: Pin support plate 21a: Pin support slide part 21b: Key groove 22: Drum hook 22a: Hook part 22b: Bearing 23: Nail 24: Trigger switch 25: Stop switch 100: Controller 133, 143: Operational amplifier

Claims (7)

A striking portion for striking the driving member;
A motor for supplying a driving force for hitting to the hitting portion;
A trigger switch that is turned on or off based on a user instruction;
An energization switch that controls energization to the motor by turning on or off based on on or off of the trigger switch; and
A time measuring means for turning off the energization switch after elapse of time according to a power supply voltage after the trigger switch is turned on;
A holding unit that holds an on state or an off state of the energization switch so that the state where the energization to the motor is cut off is held;
A driving machine characterized by comprising:   2. The driving machine according to claim 1, wherein the time corresponding to the power supply voltage is longer than a normal driving time for driving the driving member once.   3. The driving machine according to claim 1, wherein the time measuring means is configured by an analog element. The timing means is
Voltage comparison means using an analog element that outputs a signal corresponding to a difference between the power supply voltage and a predetermined voltage,
A capacitor for accumulating electric charge according to the output of the voltage comparison means;
A resistor connecting the voltage comparing means and the capacitor;
When the voltage of the capacitor is equal to or higher than a predetermined voltage, an energization cutoff means by an analog element that outputs a signal for turning off the energization switch;
The driving machine according to claim 3, wherein:   The driving machine according to any one of claims 1 to 4, further comprising a holding portion by an analog element that holds an off state of the energization switch. A moving part that is connected to the striking protrusion in a first state and is disconnected from the striking protrusion in a second state;
A stop switch that is turned on or off according to the position of the moving unit;
Further comprising
The drive motor supplies a driving force for movement to the moving unit,
6. The driving switch according to claim 5, wherein the energization switch is turned on or off in response to on or off of the trigger switch, on or off of the stop switch, and an off signal of the time measuring means. Machine.   7. The driving machine according to claim 6, wherein the energization switch is turned off by at least one of an on / off state of the stop switch and an off signal of the time measuring means.

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