WO2014084222A1

WO2014084222A1 - Pounding tool

Info

Publication number: WO2014084222A1
Application number: PCT/JP2013/081825
Authority: WO
Inventors: 瀛楊; 健也 ▲柳▼原
Original assignee: 株式会社マキタ
Priority date: 2012-11-27
Filing date: 2013-11-26
Publication date: 2014-06-05
Also published as: JP2014104534A

Abstract

[Problem] To logically drive a piston in a pounding tool. [Solution] A nailing machine (100) is configured so as to have a compression cylinder (131), a compression piston (133), a crank mechanism (115), an electric motor (211), and a control device (109). The control device (109) is configured so as to be capable of selectively setting a conduction angle in relation to the electric motor (211) to a first conduction angle and a second conduction angle. The first conduction angle is a conduction angle of 120 to 180 degrees, inclusive. The second conduction angle is a conduction angle of 120 to 180 degrees, inclusive, and is greater than the first conduction angle. In addition, the control device (109) switches the conduction angle between the first conduction angle and the second conduction angle during one cycle of driving the compression piston (133), in which the compression piston (133) moves again to bottom dead center after passing from bottom dead center to top dead center. In addition, the electric motor (211) is driven by setting the conduction angle to both the first and the second conduction angles.

Description

Driving tool

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

US Pat. No. 8,079,504 discloses 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 then 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.

However, in the driving tool described above, there is room for further improvement regarding the driving of the piston driven by the motor.

Therefore, an object of the present invention is to provide a technique for rationally driving a piston in a driving tool.

The above problem is solved by the invention according to claim 1. According to the preferable form of the driving tool according to the present invention, the driving tool for driving the driving tool out of the injection port is configured. The driving tool controls a cylinder, a piston that can slide in the cylinder, a crank mechanism that drives the piston, a three-phase brushless motor that is supplied with current from a battery and drives the crank mechanism, and a three-phase brushless motor. And a controller. In the driving tool, the driving tool is driven out by using the pressure fluctuation of the air in the cylinder caused by the sliding of the piston. The controller can selectively set the energization angle for the three-phase brushless motor to the first energization angle and the second energization angle. The first energization angle is an energization angle of 120 degrees or more and 180 degrees or less. The second energization angle is an energization angle of 120 degrees or more and 180 degrees or less, and is an energization angle larger than the first energization angle. Then, the controller determines that the energization angle is the first energization angle and the second energization angle during one cycle of driving of the piston in which the piston passes from the top dead center to the bottom dead center and moves to the bottom dead center again. And the three-phase brushless motor is driven by setting both the first energization angle and the second energization angle.

According to the present invention, during one cycle of driving the piston, the conduction angle is set to both the first conduction angle and the second conduction angle. By changing the conduction angle, the rotational speed and output torque of the three-phase brushless motor can be changed. Therefore, the driving of the piston in one cycle is rationally performed by using two energization angles.

According to the further form of the driving tool which concerns on this invention, a controller is energized when a piston is located in the 1st area | region close | similar to a top dead center in the compression process which a piston goes from a bottom dead center to a top dead center. The corner is set to the first conduction angle. On the other hand, when the piston is located in the second region farther from the top dead center than the first region, the energization angle is set to the second energization angle.

According to this embodiment, when the three-phase brushless motor is driven at the first energization angle, the output torque is larger than when driven at the second energization angle. Further, the pressure of the air in the cylinder in the compression process increases as the piston approaches the top dead center. Therefore, the output torque can be increased by driving the three-phase brushless motor at the first conduction angle in the first region near the top dead center where the driving force necessary for driving the piston is large. Thereby, the air in a cylinder is compressed appropriately. On the other hand, when the piston is close to bottom dead center, the air pressure in the cylinder is low. That is, a large driving force is not required to drive the piston. Therefore, in the second region near the bottom dead center, the rotational speed can be increased by driving the three-phase brushless motor at the second conduction angle. Thereby, the time of 1 cycle in the drive of a piston is shortened.

According to the further form of the driving tool according to the present invention, the controller sets the conduction angle in the process other than the compression process to the second conduction angle.

According to this embodiment, in a process other than the compression process, a large driving force is not required to drive the piston. Therefore, the rotational speed can be increased by driving the three-phase brushless motor at the second energization angle. Thereby, the time of 1 cycle in the drive of a piston is shortened.

According to the further form of the driving tool which concerns on this invention, a controller sets the electricity supply angle in the compression process which a piston goes from a bottom dead center to a top dead center to a 1st electricity supply angle, and supplies electricity in processes other than a compression process. The corner is set to the second conduction angle.

According to the present embodiment, since a large driving force is required to drive the piston in the compression process, the output torque can be increased by driving the three-phase brushless motor at the first conduction angle. Thereby, in a compression process, the pressure in a cylinder is compressed appropriately. On the other hand, in processes other than the compression process, a large driving force is not required to drive the piston, so that the rotational speed can be increased by driving the three-phase brushless motor at the second conduction angle. Thereby, the time of 1 cycle in the drive of a piston is shortened.

According to the further form of the driving tool according to the present invention, the controller selects and sets the first energization angle and the second energization angle according to the pressure value of the air in the cylinder. Preferably, the controller sets the first conduction angle when the pressure value of the air in the cylinder is equal to or greater than the predetermined threshold value, and sets the second pressure value when the pressure value of the air in the cylinder is less than the threshold value. Set to conduction angle.

According to this embodiment, by using two energization angles, the driving of the piston according to the magnitude of the air pressure in the cylinder is rationally performed in one cycle.

According to the further form of the driving tool according to the present invention, the controller sets the timing at which the first energization angle and the second energization angle in one cycle are switched according to the remaining battery level of the battery. Then, at the timing, the first energization angle and the second energization angle are switched, and the three-phase brushless motor is driven. Preferably, a sensor for detecting the remaining battery level is provided. In the compression process in which the piston moves from the bottom dead center to the top dead center, the controller starts moving the piston from the bottom dead center when the remaining battery level detected by the sensor is equal to or greater than a predetermined threshold. The second energization angle is switched to the first energization angle at the timing when the first time has elapsed. On the other hand, when the remaining battery level is less than the threshold, the controller starts from the second energization angle at a timing when a second time longer than the first time elapses after the piston starts moving from the bottom dead center. Switch to 1 conduction angle.

According to this embodiment, the timing at which the energization angle is switched in one cycle is rationally set according to the remaining battery level.

According to the further form of the driving tool according to the present invention, the timing of switching between the first energization angle and the second energization angle set within a predetermined cycle of driving the piston is determined by a plurality of piston driving operations thereafter. This applies to the cycle.

According to this embodiment, the timing for switching between the first energization angle and the second energization angle is set similarly for a plurality of cycles. Therefore, the speed at which the driving tool is driven out is constant in a plurality of cycles. Thereby, the driving tool is stably driven out.

According to the present invention, the driving of the piston is rationalized in the 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 in a first embodiment of the present invention. 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 circuit diagram which shows the control system of a nailing machine. It is a figure which shows the time chart of the voltage of each phase in the conduction angle of 120 degree | times. It is a figure which shows the time chart of the voltage of each phase in the conduction angle of 150 degree | times. It is a figure which shows the time chart of the conduction angle in 1 cycle of a drive of a compression piston. It is a figure which shows the time chart equivalent to FIG. 12 in 2nd Embodiment of this invention.

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. In the first embodiment, an electro-pneumatic nailer will be described 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) as driving tools to be driven into the workpiece. The main body housing 101 is joined together by 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 101 A, the compression device housing portion 101 B, and the motor housing portion 101 C are arranged so as to form a substantially rectangular shape in a side view of the nail driver 100. 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 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). In FIG. 1, the right direction is the nail launch direction. For convenience of explanation, the front end side (right side in FIG. 1) of the nailing machine 100 is referred to as the front side, and the opposite side (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. 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 driven by compressed air supplied to the cylinder chamber 121a and can move linearly in the major axis direction of the cylinder 121. Therefore, the driver 125 moves forward in the driving passage 141a of the driver guide 141, and drives out the nail. 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 on the front end side of the main body housing 101, that is, in front of the compression device housing portion 101 B. This magazine 105 accommodates nails. Further, the magazine 105 is connected to the driver guide 141, and is configured to supply nails to the driving passage 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 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. The compression cylinder 131 and the compression piston 133 are implementation configuration examples corresponding to “cylinder” and “piston” in the present invention, respectively.

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 disposed 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 of the compression piston 133 adjacent to the driving cylinder 121. The compression cylinder 131 includes an atmospheric release valve (not shown), and the compression chamber 131a is configured to be released to the atmosphere. The air release valve is normally kept closed.

As shown in FIG. 3, the motor housing portion 101 C houses an electric motor 211. The electric motor 211 is configured as a three-phase brushless motor. The electric motor 211 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 211 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 current to the electric motor 211 is detachably mounted.

As shown in FIG. 3, the rotation of the electric motor 211 is transmitted to the crank mechanism 115 after being decelerated by the planetary gear type reduction mechanism 113. The rotation of the electric motor 211 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 electric motor 211 is an implementation configuration example corresponding to the “three-phase brushless motor” in the present invention.

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 115 a is driven by the rotation of the electric motor 211 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 crank mechanism 115 is an implementation configuration example corresponding to the “crank mechanism” in the present invention.

The handle 103 is provided with a trigger 103a and a trigger switch 103b. The electric motor 211 is controlled in accordance with the operation of the trigger 103 a provided on the handle portion 103 and the driver guide 141 provided on 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 101 side, the contact arm switch 143 is turned on. Further, as shown in FIG. 3, a control device 109 is disposed below the crank mechanism 115. The electric motor 211 is controlled by the control device 109 in accordance with the operation of the trigger 103 a provided on the handle portion 103 and the driver guide 141 provided on the distal end region of the main body housing 101. That is, the electric motor 211 is energized when both the trigger switch 103b and the contact arm switch 143 are switched on, and is stopped when 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. Then, by switching energization to the electromagnet 138, the electromagnetic valve 137 moves in the front-rear direction. 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 is in contact with the inner wall surface of the valve chamber 137a in front of the annular groove 121c and blocks 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 when the crank angle is 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. The Hall element 152 detects the position of the crankshaft 115a, and the control device 109 defines the state where the compression piston 133 is located at the bottom dead center as the initial state. This 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 211 is driven. Thereby, 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 at the upper end position (top dead center) at a crank angle of 180 degrees, the control device 109 controls the electromagnet 138 and moves the electromagnetic valve 137 backward. . 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 waiting in 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 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. 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 energization to the electric motor 211 is cut off and the electric motor 211 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.

As shown in FIG. 9, the nailing machine 100 is provided with a switching circuit 255 and a position sensor 260 for driving an electric motor 211 that is a three-phase brushless motor. The switching circuit 255 is provided with six switch elements 255a to 255f. Three position sensors 260 are arranged at predetermined positions in the circumferential direction of the rotor so as to detect the position of the rotor of the electric motor 211. The position sensor 260 is arranged, for example, every 120 degrees in the circumferential direction of the rotor.

When driving the electric motor 211, the control device 109 controls the switching circuit 255 based on the position of the rotor detected by the position sensor 260. That is, the control device 109 drives the electric motor 211 by controlling the current to be supplied to the stator coils 211U, 211V, and 211W based on the position of the rotor. That is, the control device 109 drives the electric motor 211 by switching ON / OFF of each switch element as follows. By turning on only the

switch elements

255a and 255d, current is supplied from the stator coil 211U to the stator coil 211V. By turning on only the

switching elements

255a and 255f, current is supplied from the stator coil 211U to the stator coil 211W. By turning on only the

switch elements

255c and 255f, current is supplied from the stator coil 211V to the stator coil 211W. By turning on only the switching

elements

255c and 255b, a current is supplied from the stator coil 211V to the stator coil 211U. By turning on only the

switching elements

255e and 255b, a current is supplied from the stator coil 211W to the stator coil 211U. By turning on only the

switch elements

255e and 255d, current is supplied from the stator coil 211W to the stator coil 211V.

As shown in FIGS. 10 and 11, the control device 109 controls the voltages applied to the 212U, 212V, and 212W as the U, V, and W phase terminals 212 so as to change in a rectangular waveform. FIG. 10 is a voltage waveform in a state where the conduction angle is set to 120 degrees. FIG. 11 shows a voltage waveform in a state where the conduction angle is set to 150 degrees. The control device 109 is configured so that the energization angle can be selectively set to 120 degrees and 150 degrees. 10 and 11, the horizontal axis represents the mechanical angle of the rotor, and the vertical axis represents the voltage of each phase. This conduction angle of 120 degrees is an implementation configuration example corresponding to the “first conduction angle” in the present invention. Further, the conduction angle of 150 degrees is an implementation configuration example corresponding to the “second conduction angle” in the present invention.

The rotation speed of the electric motor 211 increases and the output torque decreases as the energization angle increases. That is, when the electric motor 211 is driven at an energization angle of 150 degrees, the rotational speed is higher (the rotation speed is higher) and the output torque is lower than when the electric motor 211 is driven at an energization angle of 120 degrees. Therefore, in the first embodiment, in one cycle of driving the compression piston 133, the control device 109 performs control so that the energization angle of the electric motor 211 is selectively switched between 120 degrees and 150 degrees.

In the compression process in which the compression piston 133 moves from the bottom dead center to the top dead center, the air in the compression chamber 131a is compressed and the pressure gradually increases. Therefore, the closer the position of the compression piston 133 is to the bottom dead center, the smaller the driving force required to drive the compression piston 133. On the other hand, the closer the position of the compression piston 133 is to top dead center, the greater the driving force required to drive the compression piston 133. In addition, the driving force required to drive the compression piston 133 is small except for the compression process.

Therefore, as shown in FIG. 12, when the compression piston 133 starts moving from the bottom dead center to the top dead center in the compression process in which the crank angle is 0 degree to 180 degrees, the control device 109 has the conduction angle. Is set to 150 degrees (A2), and the electric motor 211 is controlled. That is, when the compression piston 133 is located in a region near the bottom dead center, the control device 109 sets the energization angle to 150 degrees and drives the electric motor 211. Note that the horizontal axis in FIG. 12 indicates the crank angle.

When the compression piston 133 starts moving and a predetermined time elapses, the control device 109 controls the electric motor 211 by switching the conduction angle from 150 degrees (A2) to 120 degrees (A1). That is, when the compression piston 133 is located in a region close to top dead center, the control device 109 sets the energization angle to 120 degrees and drives the electric motor 211. In the first embodiment, the predetermined time after the compression piston 133 starts moving from the bottom dead center as the timing at which the conduction angle is switched is set as the time corresponding to the crank angle of 90 degrees from the crank angle of 0 degrees. Has been. Thereby, during the compression process of the compression piston 133, the electric motor 211 is driven by switching the conduction angle from 150 degrees to 120 degrees.

After the compression piston 133 passes the top dead center (crank angle 180 degrees), the control device 109 controls the electric motor 211 by switching the conduction angle from 120 degrees (A1) to 150 degrees (A2). Then, the control device 109 stops driving the electric motor 211 so that the compression piston 133 is located at the bottom dead center (crank angle 0 degree).

When switching the energization angle of the electric motor 211 from 120 degrees to 150 degrees, the control device 109 controls the energization angle to be increased while the energization start timing is advanced, and then the energization start timing is maintained. On the other hand, when switching the energization angle of the electric motor 211 from 150 degrees to 120 degrees, the control device 109 performs control so as to reduce the energization angle while maintaining the energization start timing and then delay the energization start timing.

As described above, the control device 109 of the nailing machine 100 switches the energization angle of the electric motor 211 between 120 degrees and 150 degrees in one cycle of driving the compression piston 133. The switching of the energization angle is set so as to be similarly switched in a plurality of cycles in which the compression piston 133 is driven. That is, in each cycle of the compression piston 133, the conduction angle is switched at the same timing.

According to the first embodiment described above, when the compression piston 133 is located in a region near the bottom dead center where the driving force necessary to drive the compression piston 133 is small, the control device 109 supplies the electric motor 211 with power. The electric motor 211 is driven with the angle set to 150 degrees. Therefore, the rotational speed of the electric motor 211, that is, the moving speed of the compression piston 133 is increased. As a result, the time required for one cycle in driving the compression piston 133 is shortened. Therefore, when nails are driven out continuously, the number of nails that can be driven out per unit time increases.

In addition, according to the first embodiment, when the compression piston 133 is located in a region near the top dead center where the driving force necessary for driving the compression piston 133 is large, the control device 109 causes the energization angle of the electric motor 211 to be increased. Is set to 120 degrees to drive the electric motor 211. Therefore, the output torque of the electric motor 211 can be increased. Thereby, the air in the compression chamber 131a is compressed appropriately.

Further, according to the first embodiment, in a process other than the compression process of the compression piston 133, the control device 109 sets the energization angle of the electric motor 211 to 150 degrees and drives the electric motor 211. Therefore, the rotational speed of the electric motor 211, that is, the moving speed of the compression piston 133 is increased. As a result, the time required for one cycle in driving the compression piston 133 is shortened.

As described above, in the first embodiment, since the control device 109 switches the conduction angle of the electric motor 211 in accordance with the air pressure in one cycle of the compression piston 133, the compression piston 133 of the nail driver 100 is rationalized. Can be driven automatically. In other words, therefore, rational compression of the compression chamber 131a and shortening of the time of one cycle are compatible within one cycle.

In the first embodiment described above, the control device 109 is configured to switch the conduction angle from 150 degrees to 120 degrees when the compression piston 133 starts moving from the bottom dead center and a predetermined time has elapsed. However, it is not limited to this. For example, the control device 109 may be configured to switch the energization angle according to the position of the compression piston 133 detected by the magnetic sensor 150. In this case, for example, the energization angle is set to 150 degrees from the crank angle 0 degree (bottom dead center) to the crank angle 90 degrees, and the energization is performed from the crank angle 90 degrees to the crank angle 180 degrees (top dead center). The angle is set to 120 degrees. In the above, the timing at which the energization angle is switched is not limited to the crank angle of 90 degrees, and may be, for example, a crank angle of 120 degrees or a crank angle of 150 degrees. In the above description, the control device 109 is configured to switch the energization angle based on the elapsed time or the crank angle, but is not limited thereto. For example, a sensor that detects the pressure of air in the compression chamber 131a may be provided, and the control device 109 may be configured to switch the conduction angle based on the pressure of air in the compression chamber 131a.

In the first embodiment, the energization angle is switched at the same timing in each of a plurality of cycles of the compression piston 133. However, the present invention is not limited to this. For example, a sensor that detects the remaining battery level of the battery pack 110 may be provided, and the control device 109 may be configured to switch the energization angle based on the remaining battery level. That is, when the remaining battery level decreases, the voltage value for driving the electric motor 211 decreases. Therefore, the rotation speed of the electric motor 211 is slower than when the battery level is high. In other words, even with the same energization angle, the rotation speed of the electric motor 211 varies depending on the remaining battery level. Therefore, when the remaining battery level is less than the predetermined threshold, the predetermined time from when the compression piston 133 starts moving from the bottom dead center to when the control device 109 switches the energization angle is increased. May be.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the timing at which the control device 109 switches the energization angle of the electric motor 211 is different from that in the first embodiment. The description of the same configuration as that of the first embodiment is omitted.

As shown in FIG. 13, in the second embodiment, in the compression process, the control device 109 sets the energization angle of the electric motor 211 to 120 degrees (A1) and drives the electric motor 211. On the other hand, after the compression piston 133 passes the top dead center, the control device 109 sets the energization angle of the electric motor 211 to 150 degrees (A2) and drives the electric motor 211.

According to the second embodiment described above, in the compression step of the compression piston 133, the control device 109 drives the electric motor 211 with the energization angle set to 120 degrees. Therefore, the output torque of the electric motor 211 is increased. Thereby, the air in the compression chamber 131a is compressed appropriately.

Further, according to the second embodiment, in a process other than the compression process of the compression piston 133, the control device 109 drives the electric motor 211 with the energization angle set to 150 degrees. Therefore, the rotational speed of the electric motor 211, that is, the moving speed of the compression piston 133 is increased. Thereby, the time of 1 cycle in the drive of the compression piston 133 is shortened.

In the above, the case where the conduction angle is 120 degrees and 150 degrees has been described, but the present invention is not limited to this. That is, any two energization angles between 120 degrees and 180 degrees may be set as the energization angles.

In the above description, it is possible to rationally set the conduction angle based on the pressure of air in the compression chamber 131a in one cycle of driving the compression piston 133, which is limited to the above embodiment. is not.

In view of the gist of the above invention, the driving tool according to the present invention can be configured as follows. Each embodiment can be used alone or in combination with the claimed invention.
(Aspect 1)
The controller sets the first energization angle when the pressure value of air in the cylinder is equal to or greater than a predetermined threshold, and when the pressure value of air in the cylinder is less than the threshold, A driving tool configured to be set to the second conduction angle.
(Aspect 2)
In the compression process in which the piston moves from the bottom dead center to the top dead center, the controller starts moving the piston from the bottom dead center when the remaining battery level is equal to or greater than a predetermined threshold. When the first time elapses, the second energization angle is switched to the first energization angle. When the remaining battery level is less than the threshold, the piston is at the bottom dead center. The driving is characterized in that it is configured to switch from the second energization angle to the first energization angle when a second time longer than the first time has elapsed since the start of movement. tool.

(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 shown 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 nailing machine 100 is an example of a configuration corresponding to the “driving tool” of the present invention.
The control device 109 is an example of a configuration corresponding to the “controller” of the present invention.
The crank mechanism 115 is an example of a configuration corresponding to the “crank mechanism” of the present invention.
The compression cylinder 131 is an example of a configuration corresponding to the “cylinder” of the present invention.
The compression piston 133 is an example of a configuration corresponding to the “piston” of the present invention.
The electric motor 211 is an example of a configuration corresponding to the “three-phase brushless motor” of the present invention.
The conduction angle of 120 degrees is an example of a configuration corresponding to the “first conduction angle” of the present invention.
The conduction angle of 150 degrees is an example of a configuration corresponding to the “second conduction angle” 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 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 body 125 Driver 130 Compression device 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 With drive-in passage 142 Force spring 143 Contact arm switch 150 Magnetic sensor 151 Magnet 152 Hall Element 211 Electric motor 212

Terminals

212U, 212V, 212W Terminals 255 Switching circuits 255a to 255f Switch element 260 Position sensor A1 Energization angle 120 degrees A2 Energization angle 150 degrees

Claims

A driving tool for driving a driving tool from an injection port,
A cylinder,
A piston slidable in the cylinder;
A crank mechanism for driving the piston;
A three-phase brushless motor that is supplied with current from a battery and drives the crank mechanism;
A controller for controlling the three-phase brushless motor,
It is configured to drive out the driving tool by utilizing the pressure fluctuation of the air in the cylinder caused by the sliding of the piston,
The controller can selectively set the energization angle for the three-phase brushless motor to a first energization angle and a second energization angle,
The first conduction angle is a conduction angle of 120 degrees or more and 180 degrees or less,
The second energization angle is an energization angle of 120 degrees or more and 180 degrees or less, and an energization angle larger than the first energization angle,
The controller changes the conduction angle between the first conduction angle and the second conduction during one cycle of driving of the piston, in which the piston passes from the top dead center to the bottom dead center and moves to the bottom dead center again. The three-phase brushless motor is driven by switching between the first conduction angle and the second conduction angle and switching between the first conduction angle and the second conduction angle. Driving tool.
The driving tool according to claim 1,
In the compression process in which the piston moves from the bottom dead center to the top dead center, the controller sets the conduction angle to the first conduction when the piston is located in a first region close to the top dead center. When the piston is located in a second region farther from the top dead center than the first region, the conduction angle is set to the second conduction angle. A driving tool characterized by that.
The driving tool according to claim 2,
The controller is configured to set the energization angle in a process other than the compression process to the second energization angle.
The driving tool according to claim 1,
The controller sets the energization angle in the compression process in which the piston moves from the bottom dead center to the top dead center as the first energization angle, and sets the energization angle in a process other than the compression process to the second energization angle. A driving tool configured to be set to a conduction angle.
The driving tool according to any one of claims 1 to 4,
The driving tool is configured to select and set the first energization angle and the second energization angle according to a pressure value of air in the cylinder.
The driving tool according to claim 5,
The controller sets the first energization angle when the pressure value of air in the cylinder is equal to or greater than a predetermined threshold, and when the pressure value of air in the cylinder is less than the threshold, A driving tool configured to be set to the second conduction angle.
The driving tool according to any one of claims 1 to 6,
The controller is configured to set a timing at which the first energization angle and the second energization angle in the one cycle are switched in accordance with a remaining battery level of the battery.
The driving tool configured to drive the three-phase brushless motor by switching the first energization angle and the second energization angle at the timing.
The driving tool according to claim 7,
A sensor for detecting the remaining battery capacity;
In the compression process in which the piston moves from the bottom dead center to the top dead center, the controller determines that the piston is moved from the bottom dead center when the remaining battery level detected by the sensor is equal to or greater than a predetermined threshold. When the first energization angle is switched from the second energization angle to the first energization angle at a timing when a first time has elapsed since the start of movement, and when the remaining battery level is less than the threshold, The second energization angle is switched from the second energization angle to the first energization angle at a timing when a second time longer than the first time elapses after the piston starts moving from the bottom dead center. A driving tool characterized by that.
The driving tool according to any one of claims 1 to 8,
The timing for switching the first energization angle and the second energization angle set within a predetermined cycle of driving the piston is applied to a plurality of subsequent cycles of driving the piston. A driving tool characterized by comprising.