WO2014061807A1

WO2014061807A1 - Driving tool

Info

Publication number: WO2014061807A1
Application number: PCT/JP2013/078383
Authority: WO
Inventors: 瀛楊; 健也 ▲柳▼原
Original assignee: 株式会社マキタ
Priority date: 2012-10-19
Filing date: 2013-10-18
Publication date: 2014-04-24
Also published as: JP2014083601A

Abstract

In the present invention, a nailing machine (100) is configured having: an electric motor (111); a crank shaft (115a) driven by the electric motor (111); a piston (133) driven by the crank shaft (115a); a control device (109) that controls the electric motor (111); a magnetic sensor (150) that detects the position of the crank shaft (115a); and a voltage sensor (160) and current sensor (161) for detecting the operational state of the electric motor (111). The control device (109) is configured in a manner so as to calculate the estimated angular velocity of the crank shaft (115a) corresponding to the state of the crank shaft (115a) on the basis of the detection results of the voltage sensor (160) and current sensor (161). Also, the control device (109) halts the driving of the electric motor (111) when the difference between the estimated angular velocity and the angular velocity of the crank shaft (115a) on the basis of the detection results of the magnetic sensor (150) exceeds a predetermined threshold.

Description

Driving tool

The present invention relates to a driving tool for driving a driving tool.

US Pat. No. 8,079,504 describes a driving tool for driving a driving tool into a workpiece. In the driving tool, the first piston generates compressed air in the first cylinder, and the compressed air is sent to the second cylinder. The compressed air moves the second piston in the second cylinder. Due to the movement of the second piston, the second piston strikes the driving tool. Thereby, the driving tool is driven out toward the workpiece. The driving tool has a sensor that detects the position of the first piston during an operation cycle in which the driving tool is driven. And a control apparatus stops electricity supply to a motor according to the position of the 1st piston detected by the said sensor. This stops the first piston in the proper position for the next operating cycle.

However, in the above driving tool, when the sensor breaks down, there is a possibility that the driving operation of the driving tool may be defective due to insufficient air compression or excessive air compression.

Therefore, an object of the present invention is to provide a further improvement technique related to a detection technique in a driving tool.

The above problem is solved by the invention of claim 1. According to a preferred form of the driving tool according to the present invention, a motor, a crank member driven by the motor, a piston driven by the crank member, a controller for controlling the motor, and a first for detecting the state of the crank member. A driving tool having a sensor and a second sensor for detecting the operation state of the motor is configured. The controller is configured to calculate an estimated crank state information value corresponding to the state of the crank member based on the detection result of the second sensor. The controller is configured to stop driving the motor when the difference between the state information value related to the state of the crank member based on the detection result of the first sensor and the estimated crank state information value exceeds a predetermined threshold. Yes. Note that detecting the state of the crank member means detecting the position, speed, or acceleration of the crank member. That is, the estimated crank state information value means a value corresponding to the position, speed, or acceleration of the crank member calculated based on the detection result of the second sensor. “Detecting the operating state of the motor” means the position and rotational speed of the rotating shaft of the motor, the current and voltage supplied to the motor, or the position and rotation of the component connected to the motor and driven by the motor. It preferably includes detecting the speed.

According to the present invention, since the first sensor that directly detects the state of the crank member and the second sensor that indirectly detects the state of the crank member are provided, the detection is based on the detection results of the first sensor and the second sensor. Whether or not the first sensor is operating normally is detected based on the difference in the state of the crank member. That is, when an abnormality occurs in the first sensor, it is possible to prevent the driving tool from being driven out from the driving tool by stopping the driving of the motor.

According to the further form of the driving tool according to the present invention, the controller is configured to calculate the estimated crank angular velocity of the crank member based on the detection result of the second sensor as the estimated crank state information value. In this case, the first sensor may detect the angular velocity of the crank member. On the other hand, the first sensor may detect the position or angular acceleration of the crank member, and the controller may calculate the angular acceleration of the crank member.

According to this embodiment, whether or not the first sensor is operating normally is confirmed based on the difference in the angular velocity of the crank member obtained from the detection results of the first sensor and the second sensor.

According to a further aspect of the driving tool according to the present invention, the second sensor is configured to detect a current value and a voltage value supplied to the motor. Then, the controller is configured to calculate an estimated crank angular speed as an estimated crank state information value by calculating the rotational speed of the motor from the current value and the voltage value. Therefore, the second sensor preferably has an ammeter and a voltmeter.

According to this embodiment, the angular speed of the crank is calculated from the rotational speed of the motor based on the detection result of the second sensor. The relationship between the motor current value, voltage value, and rotational speed is determined by the motor configuration as the motor drive characteristics. Therefore, the rotation speed of the motor is calculated by detecting the current value and the voltage value by the second sensor. That is, the angular speed of the crank member can be easily calculated based on the rotational speed of the motor.

According to the further form of the driving tool according to the present invention, the controller is configured to calculate the estimated crank position of the crank member based on the detection result of the second sensor as the estimated crank state information value. In this case, the first sensor may detect the position of the crank member. On the other hand, the first sensor may detect the angular velocity or angular acceleration of the crank member, and the controller may calculate the position of the crank member. As a crank position, it is preferable to calculate a crank angle when the initial position of the crank member is 0 degree.

According to this embodiment, whether or not the first sensor is operating normally is confirmed based on the difference in the position of the crank member obtained from the detection results of the first sensor and the second sensor.

According to the further form of the driving tool according to the present invention, the reduction gear is arranged between the motor and the crank member. The second sensor is configured to detect the rotational position of the reduction gear.

According to this embodiment, the rotational speed of the motor is reduced in the reduction gear. Therefore, the rotational position of the reduction gear is accurately detected by the second sensor. Therefore, the position of the crank member is calculated with high accuracy.

According to a further aspect of the driving tool according to the present invention, the controller has an informing means for informing that the driving of the motor has been stopped. As the notification means, it is preferable to use light emitting means, vibration generating means, sound generating means or the like. As the light emitting means, typically, an LED, a laser irradiation device, or the like is used. As the vibration generating means, typically, a means that includes a motor and generates vibration by the rotation of the motor is used. As the sound generation means, typically, a means that includes a speaker and outputs a stored sound source from the speaker is used.

According to this embodiment, it is possible to notify the user that the driving of the motor is stopped by the notification means.

ADVANTAGE OF THE INVENTION According to this invention, the further improvement technique regarding the detection technique in a driving tool can be provided in a driving tool.
Other features, actions, and advantages of the present invention can be readily understood with reference to the specification, claims, and accompanying drawings.

1 is an external view showing an overall configuration of an electro-pneumatic nailer. FIG. It is A arrow directional view of FIG. It is sectional drawing which shows the whole structure of the internal mechanism of a nailing machine. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. FIG. 5 is a sectional view taken along line VV in FIG. 2. FIG. 4 is a cross-sectional view taken along the line VI-VI in FIG. 3 and shows a state where the valve is closed. FIG. 6 shows a nailing state in which the valve is opened and the driving piston is moved forward. FIG. 6 shows a state in which the open state of the valve is maintained, and the driving piston is returned to the vicinity of the rear initial position. It is a block diagram which shows the control system of the nail driver in 1st Embodiment. It is a block diagram which shows the control system of the nail driver in 2nd Embodiment.

The configurations and methods according to the above and the following description are separately or separately from other configurations or methods in order to realize the manufacture and use of the “driving tool” according to the present invention and the use of the components of the “driving tool”. Can be used in combination. Exemplary embodiments of the present invention include these combinations and will be described in detail with reference to the accompanying drawings. The following detailed description is only to teach those skilled in the art with detailed information to implement preferred embodiments of the invention, and the scope of the invention is not limited by the detailed description, but is limited by the scope of the claims. It is determined based on the description. For this reason, combinations of configurations and method steps in the following detailed description are not all essential to implement the present invention in a broad sense, but are described in detail with reference numerals in the accompanying drawings. However, only representative embodiments of the present invention are disclosed.
(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. The first embodiment will be described using an electro-pneumatic nailer as an example of a driving tool. As shown in FIGS. 1 and 2, the nailing machine 100 is configured mainly by a main body housing 101 and a magazine 105 when viewed generally. The main body housing 101 constitutes a tool main body and forms an outline of the nailing machine 100. The magazine 105 is loaded with nails (not shown) that are driven into the workpiece. The main body housing 101 is formed by joining together a pair of substantially symmetrical housings. The main body housing 101 includes a handle portion 103, a driving mechanism housing portion 101A, a compression device housing portion 101B, and a motor housing portion 101C.

The handle portion 103, the driving mechanism housing portion 101A, the compression device housing portion 101B, and the motor housing portion 101C are arranged so as to form a substantially square shape in a side view. The handle portion 103 is a long member extending at a predetermined length. One end side of the handle portion 103 is connected to one end side of the driving mechanism housing portion 101A, and the other end side of the handle portion 103 is connected to one end side of the motor housing portion 101C. On the other hand, the compression device housing portion 101 </ b> B is disposed so as to extend substantially parallel to the handle portion 103. One end side of the compression device accommodating portion 101B is connected to the other end side of the driving mechanism accommodating portion 101A, and the other end side of the compression device accommodating portion 101B is connected to the other end side of the motor accommodating portion 101C. Thus, the nailing machine 100 forms a space S surrounded by the handle portion 103, the driving mechanism housing portion 101A, the compression device housing portion 101B, and the motor housing portion 101C.

As shown in FIG. 1, in the nailing machine 100, a driver guide 141 and an LED 107 are arranged at the tip (right end in FIG. 1). The direction toward the right side of FIG. 1 is the nail launch direction. For convenience of explanation, the front end side (the right side in FIG. 1) of the nailing machine 100 is referred to as the front side, and the opposite side (the left side in FIG. 1) is referred to as the rear side. Further, in the nailing machine 100, the connection side (upper side in FIG. 1) of the handle portion 103 with the driving mechanism housing portion 101A is the upper side, and the connection side (lower side in FIG. 1) of the handle portion 103 with the motor storage portion 101C is down. Called the side.

As shown in FIG. 3, the driving mechanism accommodating portion 101A accommodates the nail driving mechanism 120. The nail driving mechanism 120 is mainly composed of a driving cylinder 121 and a driving piston 123.

The driving cylinder 121 accommodates a driving piston 123 for driving a nail so as to be slidable in the front-rear direction (long axis direction). The driving piston 123 has a piston main body 124 and a driver 125. The piston main body 124 is slidably accommodated in the driving cylinder 121. The driver 125 is a long member. The driver 125 is provided integrally with the piston main body 124 and is disposed so as to extend forward. The piston main body 124 and the driver 125 are configured to be driven by compressed air supplied to the cylinder chamber 121a and move linearly in the long axis direction of the cylinder 121. Thus, the driver 125 is configured to drive out the nail by moving forward in the driving passage 141a of the driver guide 141. The driving cylinder chamber 121 a is formed as a space surrounded by the inner wall surface of the driving cylinder 121 and the rear surface of the piston main body 124. The driver guide 141 is disposed at the tip of the driving cylinder 121 and includes a driving passage 141a having a nail injection port at the tip.

As shown in FIG. 1, the magazine 105 is disposed in front of the compression device housing portion 101 </ b> B that is the distal end side of the main body housing 101. The magazine 105 is connected to the driver guide 141, and is configured to supply nails to the driving path 141a. As shown in FIG. 3, the magazine 105 is provided with a pusher plate 105a for pushing the nail in the supply direction (upward in FIG. 3). By this pusher plate 105a, nails are supplied one by one from the direction intersecting the driving direction into the driving passage 141a of the driver guide 141.

As shown in FIG. 3, the compression device accommodating portion 101 </ b> B accommodates the compression device 130. The compression device 130 is mainly configured by a compression cylinder 131, a compression piston 133, and a crank mechanism 115. The compression piston 133 is arranged to be slidable in the vertical direction within the compression cylinder 131. This compression piston 133 is an implementation structural example corresponding to the "piston" in this invention.

The compression cylinder 131 is disposed along the magazine 105, and the upper end side of the compression cylinder 131 is connected to the front end portion of the driving cylinder 121. The compression piston 133 is arranged so as to slide up and down along the magazine 105. The operation direction of the compression piston 133 is substantially orthogonal to the operation direction of the driving piston 123. As the compression piston 133 slides in the vertical direction, the volume of the compression chamber 131a that is the internal space of the compression cylinder 131 changes. That is, the compression piston 133 moves upward to reduce the volume of the compression chamber 131a, thereby compressing the air in the compression chamber 131a. The compression chamber 131 a is formed on the upper side close to the driving cylinder 121. The compression cylinder 131 includes an atmospheric release valve (not shown), and is configured to be able to release the compression chamber 131a to the atmosphere. The air release valve is normally kept closed.

As shown in FIG. 3, the motor housing portion 101 </ b> C houses the electric motor 111. The electric motor 111 is arranged so that the rotation axis of the motor shaft is substantially parallel to the long axis of the driving cylinder 121. Therefore, the rotation axis of the electric motor 111 is orthogonal to the operation direction of the compression piston 133. A battery mounting area is formed on the lower side of the motor housing 101C, and a rechargeable battery pack 110 that supplies power to the electric motor 111 is detachably mounted.

As shown in FIG. 3, the rotational output of the electric motor 111 is transmitted to the crank mechanism 115 after being decelerated by the planetary gear type reduction mechanism 113. The rotational motion of the electric motor 111 is converted into a linear motion by the crank mechanism 115 and transmitted to the compression piston 133. The speed reduction mechanism 113 and the crank mechanism 115 are accommodated in the inner housing 102. The inner housing 102 is disposed between the compression device housing portion 101B and the motor housing portion 101C.

The crank mechanism 115 is mainly composed of a crankshaft 115a, an eccentric pin 115b, and a connecting rod 115c. The crankshaft 115a is connected to a planetary gear type reduction mechanism 113. That is, the crankshaft 115a is rotated by the rotation of the electric motor 111 decelerated by the speed reduction mechanism 113. The eccentric pin 115b is provided at a position eccentric from the rotation center of the crankshaft 115a. One end of the connecting rod 115c is connected to the eccentric pin 115b so as to be relatively rotatable, and the other end is connected to the compression piston 133 so as to be relatively rotatable. The crank mechanism 115 is disposed below the compression cylinder 131. With the above-described configuration, a reciprocating compression device mainly including the compression cylinder 131, the compression piston 133, and the crank mechanism 115 is configured as the compression device 130. This electric motor 111 is an implementation configuration example corresponding to the “motor” in the present invention.

The handle portion 103 is provided with a trigger 103a, a trigger switch 103b, and a control device 109. The electric motor 111 is controlled by the control device 109 according to the operation of the trigger 103 a provided in the handle portion 103 and the driver guide 141 provided in the distal end region of the main body housing 101. When the trigger 103a is pulled, the trigger switch 103b is turned on. On the other hand, the trigger switch 103b is turned off by releasing the pulling operation of the trigger 103a.

Further, the driver guide 141 as a contact arm is disposed in the front end region of the main body housing 101 so as to be movable in the front-rear direction of the nailing machine 100. As shown in FIG. 6, the driver guide 141 is urged forward by an urging spring 142. When the driver guide 141 is positioned forward, the contact arm switch 143 is turned off. On the other hand, when the driver guide 141 is moved to the main body housing 107 side, the contact arm switch 143 is turned on. The electric motor 111 is energized when both the trigger switch 103b and the contact arm switch 143 are switched on, and the electric motor 111 is stopped when either one of the switches is switched off.

As shown in FIG. 5, the nail driver 100 includes an air passage 135 and a valve chamber 137 a that connect the compression chamber 131 a of the compression cylinder 131 and the cylinder chamber 121 a of the driving cylinder 121. The air passage 135 mainly includes a communication port 135a, a communication port 135b, a communication passage 135c, an annular groove 121c, and a valve chamber 137a. As shown in FIG. 4, the communication port 135 a is formed in the cylinder head 131 b of the compression cylinder 131. The communication port 135a communicates with the compression chamber 131a. As shown in FIG. 5, the communication port 135 b is formed in the cylinder head 121 b of the driving cylinder 121. The communication port 135b communicates with the valve chamber 137a. The communication path 135c connects the communication port 135a and the communication port 135b. The communication path 135 c extends linearly in the front-rear direction along the driving cylinder 121.

As shown in FIG. 5, the communication port 135b communicates with an annular groove 121c formed in the peripheral surface of the valve chamber 137a. The annular groove 121c communicates with the valve chamber 137a. Further, the valve chamber 137a communicates with the cylinder chamber 121a. Thus, the communication port 135b communicates with the cylinder chamber 121a via the annular groove 121c and the valve chamber 137a. An electromagnetic valve 137 that opens and closes the air passage 135 is accommodated in the valve chamber 137a.

The electromagnetic valve 137 is a columnar member having substantially the same diameter as the piston main body 124 of the driving piston 123. The electromagnetic valve 137 is disposed so as to be movable in the front-rear direction within the valve chamber 137a. An electromagnet 138 is disposed behind the electromagnetic valve 137. The electromagnetic valve 137 moves in the front-rear direction by switching energization to the electromagnet 138 and switching off the energization. On the outer periphery of the electromagnetic valve 137, two O-

rings

139a and 139b are arranged at a predetermined interval in the front-rear direction. The electromagnetic valve 137 moves rearward to open the annular groove 121c, and moves forward to close the annular groove 121c.

Specifically, as shown in FIG. 6, the front O-ring 139a contacts the inner wall surface of the valve chamber 137a in front of the annular groove 121c, thereby blocking communication between the annular groove 121c and the cylinder chamber 121a. . Further, as shown in FIG. 7, when the O-ring 139a moves into the region of the annular groove 121c, the annular groove 121c communicates with the cylinder chamber 121a. The rear O-ring 139b prevents the compressed air from leaking outside from the communication port 135b. That is, the O-ring 139b is not involved in opening / closing the annular groove 121c. Thus, the electromagnetic valve 137 that opens and closes the air passage 135 is provided in the air passage 135 on the connection side of the driving cylinder 121 with the cylinder chamber 121a.

As shown in FIG. 6, the electromagnetic valve 137 is always disposed in front of the annular groove 121 c closed by the electromagnet 138. The stopper 136 is disposed in front of the electromagnetic valve 137 and restricts the movement of the electromagnetic valve 137 forward. The stopper 136 is formed by a flange-like member protruding in the radial direction in the cylinder chamber 121a. Further, the stopper 136 defines the rear end position of the driving piston 123 that moves rearward.

Next, the operation of the nailing machine 100 will be described. As shown in FIG. 3, the nailing machine 100 has an initial position in which the driving piston 123 is located at the rear end position (left end position in FIG. 3) and the compression piston 133 is located at the lower end position (bottom dead center). It is defined as. That is, the initial state is defined as a crank angle of 0 degrees (bottom dead center).

Specifically, as shown in FIG. 3, the nail driver 100 includes a magnetic sensor 150. The magnetic sensor 150 is mainly composed of a magnet 151 and a hall element 152. The magnet 150 is provided on the crankshaft 115a. On the other hand, the hall element 152 is provided at a position facing the magnet 151 of the compression device housing portion 101B. The hall element 152 is electrically connected to the battery pack 110 and further connected to the control device 109. Hall element 152 detects the position of crankshaft 115a. This magnetic sensor 150 is an implementation configuration example corresponding to the “first sensor” in the present invention. The control device 109 is an implementation configuration example corresponding to the “controller” in the present invention.

In the initial state shown in FIG. 3, the driver guide 141 is pressed against the workpiece and the contact arm switch 143 (see FIG. 6) is turned on, and the trigger 103a is pulled and the trigger switch 103b is turned on. When switched to, the electric motor 111 is energized. As a result, the crank mechanism 115 is driven via the speed reduction mechanism 113, and the compression piston 133 moves upward. At this time, since the electromagnetic valve 137 closes the air passage 135, the air in the compression chamber 131a is compressed by the movement of the compression piston 133.

When the magnetic sensor 150 detects that the compression piston 133 is positioned at the upper end position (top dead center) where the crank angle is 180 degrees, the control device 109 controls the electromagnet 138 and moves the electromagnetic valve 137 backward. Move to. That is, when the compressed air in the compression chamber 131a is in the maximum compressed state, the electromagnetic valve 137 is opened. Thereby, the annular groove 121c communicates with the cylinder chamber 121a, and the compressed air in the compression chamber 131a is supplied into the cylinder chamber 121a through the air passage 135. When compressed air is supplied into the cylinder chamber 121a, the driving piston 123 is moved forward by the action of the air spring by the compressed air, as shown in FIG. Then, the driver 125 of the driving piston 123 moved forward hits the nail of the driving passage 141a (see FIG. 3). Thereby, a driving operation for driving out the nail is performed.

After the launch operation, the compression piston 133 moves toward the bottom dead center. At that time, the volume of the compression chamber 131a is increased, and the air in the compression chamber 131a becomes a negative pressure lower than the atmospheric pressure. The negative pressure generated in the compression chamber 131a is driven through the air passage 135 and the cylinder chamber 121a and acts on the piston 123. Thereby, as shown in FIG. 8, the driving piston 123 is sucked and moved rearward. The driving piston 123 is in contact with the stopper 136 and is located at the initial position. When the magnetic sensor 150 detects that the position of the compression piston 133 is a bottom dead center with a crank angle of 0 degrees, the control device 109 controls the electromagnet 138 and moves the electromagnetic valve 137 forward. As a result, the air passage 135 is closed. Note that when the compression piston 133 returns to the initial position, even if the trigger switch 103b and the contact arm switch 143 are maintained in the ON state, the power supply to the electric motor 111 is cut off and the electric motor 111 is stopped. In this way, one cycle of the launching operation is completed. During the launching operation, the LED 107 irradiates the tip region of the driver guide 141.

In the nailing machine 100 described above, if the magnetic sensor 150 fails, the position of the compression piston 133 may not be detected or the position of the compression piston 133 may not be detected accurately. When the position of the compression piston 133 cannot be detected, the control device 109 performs control so that the nail driver 100 is not driven. On the other hand, if the position of the compression piston 133 cannot be accurately detected due to a malfunction of the magnetic sensor 150, a problem may occur in the launching operation. For example, when the compression piston 133 is not stopped at the bottom dead center, when the launching operation is started, the compression amount of the compressed air generated by the compression piston 133 differs depending on the position of the compression piston 133 at the start of the launching operation. . For this reason, the speed of the nail to be launched for each launch operation is not constant, and the amount of nail to be driven into the workpiece is different.

Therefore, in the first embodiment, as shown in FIG. 9, a voltage sensor 160 and a current sensor 161 for detecting the voltage value and current value of the electric motor 111 are provided. The relationship between the current value, voltage value, and rotational speed of the electric motor 111 is uniquely determined by the configuration of the electric motor 111 as drive characteristics of the electric motor 111. Therefore, the control device 109 calculates the rotation speed of the electric motor 111 from the voltage value and current value detected by the voltage sensor 160 and the current sensor 161. Furthermore, the control device 109 calculates the estimated angular velocity of the crankshaft 115a from the rotation speed of the electric motor 111 and the reduction ratio of the reduction mechanism 113. This crankshaft 115a is an implementation structural example corresponding to the "crank member" in this invention. In addition, the voltage sensor 160 and the current sensor 161 that detect the voltage value and the current value, which are the operating states of the electric motor 111, are implementation configuration examples corresponding to the “second sensor” in the present invention. That is, the “second sensor” has two sensors. Further, the estimated angular velocity of the crankshaft 115a calculated based on the detection results of the voltage sensor 160 and the current sensor 161 is an implementation configuration example corresponding to the “estimated crank state information value” in the present invention.

Meanwhile, the control device 109 calculates the angular velocity of the crankshaft 115a based on the position (detection result) of the crankshaft 115a detected by the magnetic sensor 150 every predetermined time. The angular velocity of the crankshaft 115a calculated based on the detection result of the magnetic sensor 150 is an implementation configuration example corresponding to the “state information value” in the present invention.

Then, the control device 109 calculates the difference between the angular velocity of the crankshaft 115a calculated based on the detection result of the magnetic sensor 150 and the estimated angular velocity of the crankshaft 115a calculated based on the detection results of the voltage sensor 160 and the current sensor 161. Is calculated. When the difference between the angular velocity of the crankshaft 115a and the estimated angular velocity exceeds a predetermined threshold, the control device 109 indicates that any one of the magnetic sensor 150, the voltage sensor 160, and the current sensor 161 has failed. Assuming that the supply of electric current to the electric motor 111 is stopped. That is, the control device 109 stops driving the electric motor 111.

The voltage sensor 160 and the current sensor 161 may detect not only the voltage value and current value of the electric motor 111 but also the voltage value and current value of the driving circuit of the nailing machine 100. In such a configuration, not only the failure of the sensor but also the failure of the control device 109 or the like can be detected.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. The second embodiment differs from the first embodiment in “motor”, “second sensor”, and “state information value” and “estimated crank state information value” calculation methods. In the second embodiment, the description of the same configuration as in the first embodiment is omitted.

As shown in FIG. 10, in the second embodiment, a brushless motor 211 is used as a motor. In the brushless motor 211, the stator has a stator coil. A position sensor 260 for detecting the position of the rotor is disposed outside the rotor of the brushless motor 211. The position sensor 260 is arranged at three positions at predetermined positions in the circumferential direction of the rotor. Then, the control device 109 controls the drive of the brushless motor 211 by energizing the stator coil in accordance with the position of the rotor detected by the position sensor 260. In FIG. 10, the position sensor 260 is simply illustrated.

The control device 109 calculates the estimated position of the crankshaft 115a based on the position of the rotor detected by the position sensor 260. On the other hand, the position of the crankshaft 115 a is detected by the magnetic sensor 150. Then, the control device 109 calculates the difference between the position of the crankshaft 115a based on the detection result of the magnetic sensor 150 and the estimated position of the crankshaft 115a calculated based on the detection result of the position sensor 260. When the difference between the position of the crankshaft 115a and the estimated position exceeds a predetermined threshold value, the control device 109 regards that either the magnetic sensor 150 or the position sensor 260 has failed, and the brushless motor The supply of current to 211 is stopped. That is, the control device 109 stops driving the brushless motor 211.

Therefore, the control device 109 can calculate the estimated position of the crankshaft 115a based on the detection result of the position sensor 260 used to drive the brushless motor 211. Thereby, a failure is detected in either the magnetic sensor 150 or the position sensor 160. That is, the position sensor 260 has both a function for driving the brushless motor 211 and a function for detecting a failure of the magnetic sensor 150.

In the first embodiment and the second embodiment described above, the control device 109 turns on the

LEDs

107 and 108 when driving of the electric motor 111 and the brushless motor 211 is stopped. Thereby, it is notified that the driving of the electric motor 111 is stopped. Note that the control device 109 may not only light the

LEDs

107 and 108 but also blink them. The control device 109 may be configured to change the color of light emitted by the

LEDs

107 and 108. Further, the control device 109 may be configured to turn on or blink only one of the

LEDs

107 and 108.

According to the first and second embodiments described above, the magnetic sensor 150 that directly detects the position and angular velocity of the crankshaft 115a and the position and angular velocity of the crankshaft 115a are indirectly detected. A voltage sensor 160, a current sensor 161, and a position sensor 260 for detection are included. Therefore, the magnetism is determined based on the difference between the position and angular velocity of the crankshaft 115a based on the detection result of the magnetic sensor 150 and the estimated position and angular velocity of the crankshaft 115a based on the detection results of the voltage sensor 160, current sensor 161, and position sensor 260. Whether or not the sensor 150 is operating normally can be detected. Thereby, when abnormality occurs in the magnetic sensor 150, the driving of the nail driver 100 is stopped. That is, in the nailing machine 100, the nail is prevented from being unintentionally driven out.

In the above first embodiment, the voltage sensor 160 and the current sensor 161 are provided, but the present invention is not limited to this. If the resistance value of the electric motor 111 is set in advance, only one of the voltage sensor 160 and the current sensor 161 may be provided. That is, the current value and voltage value of the electric motor 111 are detected by calculating the current value or voltage value according to Ohm's law.

In the second embodiment described above, the position (rotational position) of the rotor of the brushless motor 211 is detected, but the present invention is not limited to this. For example, the rotational position of the speed reduction mechanism 113 that reduces the rotational speed of the motor may be detected. In the speed reduction mechanism 113, since the rotational speed of the motor is decelerated, the rotational position of the speed reduction mechanism 113 is detected with higher accuracy than when the position of the rotor is detected.

In the above, the control device 109 is configured to calculate the estimated angular velocity of the crankshaft 115a or the estimated position of the crankshaft 115a, but is not limited thereto. For example, the control device 109 may be configured to calculate the estimated angular acceleration of the crankshaft 115a. The control device 109 may be configured to calculate the estimated angular acceleration of the crankshaft 115a from the detection result of the magnetic sensor 150.

In the above description, the

LEDs

107 and 108 are provided as notification means. However, only one LED may be provided. Further, a buzzer for generating sound or an actuator for generating vibration may be provided as the notification means.

In the above description, the magnetic sensor 150 for detecting the position of the crankshaft 115a is provided. However, a sensor such as a photosensor may be provided. Moreover, it is not restricted to the structure which detects the position of the crankshaft 115a, You may be comprised so that the position of the eccentric pin 115b and the connecting rod 115c may be detected among crank mechanisms.

(Correspondence between each component of this embodiment and each component of the present invention)
The correspondence between each component of the present embodiment and each component of the present invention is as follows. In addition, this embodiment shows an example of the form for implementing this invention, and this invention is not limited to the structure of this embodiment.
The control device 109 is an example of a configuration corresponding to the “controller” of the present invention.
The electric motor 111 is an example of a configuration corresponding to the “motor” of the present invention.
The crankshaft 115a is an example of a configuration corresponding to the “crank member” of the present invention.
The compression piston 133 is an example of a configuration corresponding to the “piston” of the present invention.
The magnetic sensor 150 is an example of a configuration corresponding to the “first sensor” of the present invention.
The voltage sensor 160 is an example of a configuration corresponding to the “second sensor” of the present invention.
The current sensor 161 is an example of a configuration corresponding to the “second sensor” of the present invention.
The brushless motor 211 is an example of a configuration corresponding to the “motor” of the present invention.
The position sensor 260 is an example of a configuration corresponding to the “second sensor” of the present invention.

DESCRIPTION OF SYMBOLS 100 Nailing machine 101 Main body housing 101A Driving mechanism accommodating part 101B Compressor accommodating part 101C Motor accommodating part 102 Inner housing 103 Handle part 103a Trigger 103b Trigger switch 105 Magazine 105a Pusher plate 107 LED
108 LED
109 Control device 110 Battery pack 111 Electric motor 113 Planetary gear type reduction mechanism 115 Crank mechanism 115a Crank shaft 115b Eccentric pin 115c Connecting rod 120 Nail driving mechanism 121 Driving cylinder

121a Cylinder chamber

121b Cylinder head 121c Annular groove 123 Driving piston 124 Piston main body 125 Driver 130 Compressor 131 Compression cylinder 131a Compression chamber 131b Cylinder head 133 Compression piston 135 Air passage

135a Communication port

135b Communication port

135c Communication passage 136 Stopper 137 Electromagnetic valve 137a Valve chamber 138 Electromagnet 139a O-ring 139b O-ring 141 Driver guide 141a Driving Passage 142 Energizing spring 143 Contact arm switch 150 Magnetic sensor 151 Magnet 152 Hall element 160 Voltage sensor 161 Current sensor 211 Brushless motor 260 Position sensor

Claims

A driving tool for driving a driving tool from an injection port,
A motor,
A crank member driven by the motor;
A piston driven by the crank member;
A controller for controlling the motor;
A first sensor for detecting a state of the crank member;
A second sensor for detecting an operating state of the motor,
The controller is configured to calculate an estimated crank state information value corresponding to the state of the crank member based on a detection result of the second sensor,
The controller stops driving the motor when the difference between the state information value related to the state of the crank member based on the detection result of the first sensor and the estimated crank state information value exceeds a predetermined threshold value. A driving tool characterized by comprising.
The driving tool according to claim 1,
The driving tool is configured to calculate an estimated crank angular velocity of the crank member based on a detection result of the second sensor as the estimated crank state information value.
The driving tool according to claim 2,
The second sensor is configured to detect a current value and a voltage value supplied to the motor,
The controller is configured to calculate the estimated crank angular speed as the estimated crank state information value by calculating a rotation speed of the motor from the current value and the voltage value. tool.
The driving tool according to claim 1,
The driving tool is configured to calculate an estimated crank position of the crank member based on a detection result of the second sensor as the estimated crank state information value.
The driving tool according to claim 4,
A reduction gear is disposed between the motor and the crank member,
The driving tool according to claim 2, wherein the second sensor is configured to detect a rotational position of the reduction gear.
The driving tool according to any one of claims 1 to 5,
A driving tool comprising notification means for notifying that the controller has stopped driving the motor.