JP2017213666A - Driving machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a driving machine which can control timing at which pins arranged at a wheel and racks arranged at a driver blade are engaged with each other, and timing at which the engagement is released.SOLUTION: A driving machine 1 has: a wheel 50 which is rotationally driven by an electric motor 20; a plurality of pins arranged at the wheel 50; a piston 11 which is reciprocally accommodated in a cylinder 10; a driver blade 30 integrally reciprocating together with the piston 11; a plurality of racks arranged at the driver blade 30; and a controller 61 for controlling the electric motor 20. As control modes of the electric motor 20, the controller 61 comprises a first control mode for controlling the electric motor 20 so that the wheel 50 rotates at a first speed, and a second control mode for controlling the electric motor 20 so that the wheel 50 rotates at a second speed which is lower than the first speed. The controller switches these control modes at prescribed timing.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a driving machine for driving a stopper such as a nail or a pin into a material to be driven such as wood or gypsum board.

  The driving machine includes a piston accommodated in a cylinder so as to be reciprocable, and a driver blade integrated with the piston. The piston reciprocates between the top dead center and the bottom dead center in the cylinder, and the driver blade reciprocates as the piston reciprocates. The driving machine further includes a supply mechanism that supplies a stopper to the moving path (injection path) of the driver blade. When the driver blade rises to a predetermined position as the piston moves from the bottom dead center to the top dead center, the supply mechanism supplies a stopper to the injection passage. Thereafter, when the driver blade descends as the piston moves from the top dead center to the bottom dead center, the stop waiting in the injection passage is struck by the driver blade. The hit stopper is driven out from an injection port which is an outlet of the injection passage, and is driven into a wood or a gypsum board.

  As means for reciprocating the piston as described above, there is a driving machine using air pressure (gas spring). The piston in this type of driving machine is driven by an electric motor to move from the bottom dead center to the top dead center, while moving from the top dead center to the bottom dead center by air pressure. For example, a plurality of racks are provided on the side surface of the driver blade along the axial direction thereof. A wheel that is driven to rotate by an electric motor is provided in the vicinity of the driver blade, and a plurality of pins are provided along the circumferential direction of the wheel. When the wheel rotates, each pin provided on the wheel sequentially engages with each rack provided on the driver blade. More specifically, the wheel includes a first pin, a second pin farthest from the first pin in the rotation direction of the wheel, and a plurality of third pins arranged between the first pin and the second pin. Is provided. As the wheel rotates, the first pin first engages the rack of driver blades. Thereafter, the third pin adjacent to the first pin is engaged with the next rack, and another third pin adjacent to the third pin is further engaged with the next rack. Thereafter, each third pin sequentially engages with each rack, and pushes up the driver blade. As a result, the piston integral with the driver blade moves (ascends) from the bottom dead center to the top dead center in the cylinder.

  Thereafter, when the piston reaches top dead center, the engagement between the second pin and the rack is released. That is, the second pin is a pin that is finally engaged with the rack in one cycle, and may be referred to as a “final pin” in the following description. A rack that engages with the second pin may be referred to as a “final rack”.

  When the engagement between the final pin and the final rack is released, the piston moves from the top dead center toward the bottom dead center by the pressure of the air in the cylinder compressed as the piston rises. As the piston moves, the driver blade descends and the stop is hit by the driver blade.

  Here, the distance between the first pin and the final pin (the separation distance along the rotation direction of the wheel) is wider than the distance between the other adjacent pins. That is, the driver blade descends after the engagement between the final pin and the final rack is released and until the first pin and the other rack are re-engaged. In other words, the wheel idles until the first pin is re-engaged with the other rack after the engagement between the final pin and the final rack is released.

JP 2014-108468 A

  In the driving machine as described above, if the first pin and the rack are re-engaged before the driver blade descends to the lowest point, the descent of the driver blade stops at that point. That is, the driver blade does not descend to the lowest point and a driving failure occurs. Further, the pin and the rack are engaged while the driver blade is lowered, and an unintended load is applied to the pin and the driver blade, which may be damaged.

  Therefore, it is necessary to avoid a situation in which the first pin and the rack are reengaged before the driver blade reaches the lowest point, that is, before the piston reaches the bottom dead center. The time required from the disengagement of the collection pin and the final rack to the engagement of the first pin and another rack depends on the distance between the first pin and the final pin (the separation distance along the wheel rotation direction). To do. Therefore, in order to satisfy the above requirement, it is necessary to extend the distance between the first pin and the final pin. However, all pins including the first pin and the final pin are arranged along the circumference of the wheel. Therefore, if the distance between the first pin and the final pin is increased, the wheel becomes larger in diameter and the entire driving machine is enlarged.

  Further, when the driver blade reaches the top dead center and descends before the supply of the stopper to the injection passage is completed, idle driving occurs. Therefore, it is necessary to secure a necessary and sufficient time to complete the supply of the stopper to the injection passage. That is, it is necessary to secure the loading time of the stopper. In order to secure the loading time of the stopper, it is necessary to increase the idle running distance of the driver blade (the distance from the tip of the driver blade passing through the head of the stopper until reaching the top dead center). . However, if the idling distance is increased, the stroke of the piston becomes longer, so that the entire driving machine is increased in size.

  An object of the present invention is to realize a driving machine capable of controlling a timing at which a pin included in a wheel and a rack included in a driver blade are engaged and a timing at which the engagement is released.

  The driving machine includes a wheel that is rotationally driven by an electric motor, a plurality of pins provided on the wheel along a circumferential direction of the wheel, a piston that is reciprocally accommodated in a cylinder, and the piston. A driver blade that reciprocates integrally, a plurality of racks provided on the driver blade along an axial direction of the driver blade, and a control unit that controls the electric motor. When the wheel is driven to rotate, the pin and the rack are sequentially engaged, the driver blade is pushed up, the piston moves to the top dead center side, and the engagement between the pin and the rack is released. Then, the piston moves to the bottom dead center side, and the driver blade descends. The control unit is configured to control the electric motor so that the wheel rotates at a first speed as a control mode of the electric motor, and a second speed at which the wheel is slower than the first speed. And a second control mode for controlling the electric motor so as to rotate.

  ADVANTAGE OF THE INVENTION According to this invention, the driving machine which can control the timing with which the pin with which a wheel is equipped, and the rack with which a driver blade is equipped, and the timing with which engagement is cancelled | released is implement | achieved.

It is sectional drawing of a driving machine. It is a fragmentary sectional view of a driving machine when a piston exists in a top dead center. It is a fragmentary sectional view of a driving machine when a piston exists in a bottom dead center. It is a block diagram which shows the structure of a driving machine. It is a figure which shows an example of the change of a motor electric current and a piston position. It is a figure which shows another example of the change of a motor electric current and piston position.

(First embodiment)
Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings referred to in the following description, the same or substantially the same members are denoted by the same reference numerals.

  The driving machine 1 shown in FIG. 1 has a housing 2. The housing 2 includes a cylinder case 3, a motor case 4, and a handle 5. The cylinder case 3 contains a cylinder 10, and the motor case 4 contains an electric motor 20. The motor case 4 and the handle 5 extend substantially parallel to each other from the cylinder case 3, and the end of the motor case 4 and the end of the handle 5 are connected to each other by a connecting portion 7. The housing 2 has two housing halves formed of a synthetic resin such as nylon or polycarbonate, and the housing 2 is assembled by abutting the two housing halves.

  A piston 11 is accommodated in the cylinder 10 so as to be able to reciprocate. The piston 11 reciprocates between the top dead center and the bottom dead center along the axial direction of the cylinder 10 inside the cylinder 10. In the cylinder 10, a piston chamber 12 whose volume increases or decreases as the piston 11 reciprocates is defined by the inner peripheral surface of the cylinder 10 and the upper surface of the piston 11.

  On the other hand, a driver blade 30 is connected to the lower surface of the piston 11. The driver blade 30 is integral with the piston 11 and reciprocates together with the piston 11. Specifically, a nose portion 8 is provided at the tip of the cylinder case 3, and an injection passage 9 is provided inside the nose portion 8. The driver blade 30 reciprocates in the injection passage 9 as the piston 11 reciprocates. In the following description, the reciprocating direction of the piston 11 and the driver blade 30 in FIG. That is, the vertical direction in FIG. 1 is defined as the vertical direction.

  A magazine 41 that houses a number of fasteners 40 is attached to the housing 2. The stoppers 40 accommodated in the magazine 41 are supplied to the injection passage 9 one by one by a supply mechanism provided in the magazine 41. The driver blade 30 strikes the head 40 a of the stopper 40 that is sequentially supplied to the injection passage 9. The stopper 40 struck by the head 40 a passes through the injection passage 9, is driven out from an injection port that is an outlet of the injection passage 9, and is driven into a material to be driven such as wood or gypsum board.

  Here, the piston 11 shown in FIGS. 1 and 2 is located at the top dead center, and the tip 30a (FIG. 2) of the driver blade 30 is at the upper limit position. On the other hand, the piston 11 shown in FIG. 3 is located at the bottom dead center, and the tip 30a of the driver blade 30 is at the lower limit position. In other words, the upper limit position is the position of the tip 30a of the driver blade 30 when the piston 11 is at the top dead center, and the lower limit position is the tip of the driver blade 30 when the piston 11 is at the bottom dead center. It is the position of 30a. A rubber or urethane damper 15 is provided at the bottom of the cylinder 10. The damper 15 receives the piston 11 that has reached the bottom dead center, and avoids a collision between the piston 11 and the cylinder 10. The driver blade 30 extending downward from the piston 11 passes through the damper 15 and protrudes from the cylinder 10 through a through hole provided in the bottom of the cylinder 10.

  As shown in FIGS. 2 and 3, a wheel 50 is provided in the vicinity of the driver blade 30. The wheel 50 is fixed to a drive shaft 51 that is rotatably supported, and a plurality of pins 52 are attached to the wheel 50 at intervals along the circumferential direction. On the other hand, the driver blade 30 is provided with a plurality of racks 32 along the axial direction thereof.

  Refer to FIG. 1 again. The motor case 4 houses an electric motor 20 that is a drive source of the wheel 50, and an output shaft 21 of the electric motor 20 is connected to a drive shaft 51 of the wheel 50 via a planetary gear type reduction mechanism. Yes. The electric motor 20 is operated by electric power supplied from the battery 60 attached to the connecting portion 7 of the housing 2. In addition, a controller 61 as a control unit is accommodated in the connecting unit 7. The controller 61 is a microcomputer composed of a CPU, ROM, RAM, and the like, and controls the electric motor 20. Specifically, the electric motor 20 is a brushless motor, and the controller 61 changes the duty ratio of the motor current supplied to the electric motor 20 according to the control mode. That is, the controller 61 controls the electric motor 20 by PWM (Pulse Width Modulation). The control of the electric motor 20 will be described in detail later.

  Above the cylinder 10, a pressure accumulation container (chamber) 14 that forms a pressure accumulation chamber 13 is provided, and the pressure accumulation chamber 13 communicates with the piston chamber 12. The piston chamber 12 and the pressure accumulating chamber 13 are preliminarily filled with high-pressure gas (compressed air in this embodiment). When the piston 11 at the position (bottom dead center) shown in FIG. 3 is moved to the position (top dead center) shown in FIG. 2, the electric motor 20 (FIG. 1) is controlled based on the control of the controller 61 (FIG. 1). Operates. When the electric motor 20 is operated, the wheel 50 shown in FIG. 3 rotates counterclockwise in the drawing. That is, the wheel 50 is rotationally driven by the electric motor 20.

  When the wheel 50 rotates, the first pin 52a and the first rack 32a are engaged. Thereafter, as the wheel 50 rotates, the plurality of pins 52 on the downstream side in the rotation direction of the wheel 50 with respect to the first pins 52a and the plurality of racks 32 on the lower side with respect to the first rack 32a are sequentially engaged. Then, the driver blade 30 is gradually pushed up, and the piston 11 moves from the bottom dead center toward the top dead center. That is, the driver blade 30 and the piston 11 are raised. Thereafter, as shown in FIG. 2, when the wheel 50 is rotated until the second pin 52b located on the most downstream side in the rotation direction and the second rack 32b located on the lowermost side are engaged, the driver blade 30 is moved to the uppermost position. The piston 11 is pushed up to the position, and the piston 11 reaches the top dead center. In other words, until the second pin 52b farthest from the first pin 52a in the rotational direction of the wheel 50 and the second rack 32b farthest from the first rack 32a in the moving direction of the driver blade 30 are engaged. When the wheel 50 rotates, the driver blade 30 is pushed up to the uppermost position, and the piston 11 reaches the top dead center. When the driver blade 30 is pushed up to the uppermost position, the tip 30a of the driver blade 30 reaches the upper limit position.

  In the process of moving (raising) the piston 11 as described above, the air in the piston chamber 12 is sent into the pressure accumulating chamber 13 and compressed. When the wheel 50 shown in FIG. 2 further rotates and the engagement between the second pin 52b and the second rack 32b is released, the pressure (air pressure) of the compressed air in the piston chamber 12 and the pressure accumulating chamber 13 is released. The piston 11 moves from the top dead center to the bottom dead center, and the driver blade 30 is lowered.

  Thus, the first pin 52a and the first rack 32a are the pin 52 and the rack 32 that are initially engaged when the piston 11 at the bottom dead center is moved to the top dead center. On the other hand, the second pin 52b and the second rack 32b are the pin 52 and the rack 32 that are finally engaged when the piston 11 at the bottom dead center is moved to the top dead center. Therefore, in the following description, the second pin 52b is called “final pin 52b”, and the second rack 32b is called “final rack 32b”. In the present embodiment, the final pin 52b is slightly thicker than the other pins 52 including the first pin 52a. Further, the interval (separation angle) between the first pin 52a and the final pin 52b along the rotation direction of the wheel 50 is 60 degrees, and the interval between the other pins 52 is 30 degrees.

  Referring to FIG. 1 again, the nose portion 8 is provided with a push lever 62. The push lever 62 is held so as to be movable in the vertical direction, and is always urged downward by a coil spring. When the push lever 62 is pressed against the driven member and moves upward against the urging force of the coil spring, the push lever switch 62a (FIG. 4) is operated and the first signal is output. Further, the handle 5 is provided with a trigger lever 63. When the trigger lever 63 is operated, the trigger switch 63a (FIG. 4) built in the handle 5 is operated and the second signal is output.

  As shown in FIG. 4, the first signal output from the push lever switch 62 a and the second signal output from the trigger switch 63 a are input to the controller 61. When both the first signal and the second signal are input, the controller 61 turns on / off the switching element of the inverter circuit 64 to supply a motor current to the electric motor 20 to operate the electric motor 20. Thereby, the wheel 50 is rotationally driven as described above, the driver blade 30 is pushed up, and the piston 11 moves from the bottom dead center to the top dead center. Thereafter, the piston 11 moves from the top dead center to the bottom dead center, and the driver blade 30 is lowered. That is, the piston 11 makes one reciprocation between the bottom dead center and the top dead center, and the stop blade 40 (FIG. 1) is hit by the driver blade 30 and the stop 40 is driven out. In other words, the driving operation is executed once.

  As shown in FIG. 4, the controller 61 also receives a detection signal output from a position sensor 65 that detects the position of the pin 52 (FIGS. 2 and 3) provided on the wheel 50. The controller 61 can detect the rotation angle of the wheel 50 based on the detection signal, can also detect the position of the piston 11 based on the detected rotation angle of the wheel 50, and these detection results are also taken into account. Then, the inverter circuit 64 is controlled.

  When the driving operation is executed once, the controller 61 executes a predetermined stop control in either case of single shot or continuous shot. Specifically, the controller 61 maintains the operation of the electric motor 20 until the tip 30a of the driver blade 30 moves to the standby position, and then stops the electric motor 20. Whether or not the tip 30a of the driver blade 30 has moved to the standby position is determined based on the rotation amount (rotation angle) of the wheel 50. The rotation amount of the wheel 50 is based on a detection signal output from the position sensor 65. Detected.

  When the driving operation is finished, the piston 11 is at the bottom dead center, and thus the tip 30a of the driver blade 30 is at the lower limit position. When ending the driving operation, the controller 61 operates the electric motor 20 until the tip 30a of the driver blade 30 moves (rises) to a standby position set between the lower limit position and the upper limit position, and then the electric motor. 20 is stopped. As a result, the piston 11 moves (rises) to an intermediate position between the bottom dead center and the top dead center. In other words, the intermediate position of the piston 11 is the position of the piston 11 when the tip 30a of the driver blade 30 is in the standby position.

  The standby position is set between the lower limit position and the head 40a of the stopper 40 supplied to the injection passage 9 in the next driving operation. In other words, the standby position is a position that is higher than the lower limit position and lower than the head 40a of the stopper 40 that is supplied to the injection passage 9 during the next driving operation. In other words, the standby position is a position that is higher than the lower limit position and lower than the head 40a of the stopper 40 located at the head among the plurality of stoppers 40 held by the magazine 41. is there.

  The stop control has the following significance, for example. That is, when performing the driving operation next time, it is sufficient to move the tip 30a of the driver blade 30 from the standby position to the upper limit position. On the other hand, when the tip of the driver blade 30 is at the lower limit position, the tip 30a of the driver blade 30 must be moved from the lower limit position to the upper limit position when the next driving operation is executed. That is, if stop control is executed to move the tip 30a of the driver blade 30 to the standby position in advance, the movement distance (stroke) of the driver blade 30 necessary for executing the next driving operation is shortened, and the response Improves. In the present embodiment, the stop control is executed to make the tip 30a of the driver blade 30 stand by at a position lower than the head 40a of the leading stop 40. In this configuration, the supply of the stopper 40 to the injection passage 9 is restricted by the driver blade 30.

  The above is the basic operation of the driving machine 1 according to the present embodiment. That is, when the predetermined condition is satisfied, the electric motor 20 operates and the wheel 50 rotates under the control of the controller 61. Then, the plurality of pins 52 provided on the wheel 50 and the plurality of racks 32 provided on the driver blade 30 are sequentially engaged, and the driver blade 30 is pushed up. At the same time, the piston 11 moves from the bottom dead center side toward the top dead center side in the cylinder 10. Thereafter, when the piston 11 reaches the top dead center and the engagement between the final pin 52b and the final rack 32b is released, the piston 11 is moved from the top dead center side to the bottom dead center side by the air pressure (gas spring). The driver blade 30 moves down and the stopper 40 is driven out. Thereafter, the above operation is repeated as long as the predetermined condition is satisfied, while the operation is stopped when the predetermined condition is not satisfied. When the driving operation is finished, the tip 30a of the driver blade 30 is moved to the standby position to prepare for the next driving operation.

  The controller 61 that controls the electric motor 20 to realize the operation as described above has at least two control modes of a first control mode and a second control mode as control modes of the electric motor 20.

  When the first control mode is selected, the controller 61 controls the electric motor 20 so that the wheel 50 rotates at the first speed (V1). On the other hand, when the second control mode is selected, the controller 61 controls the electric motor 20 so that the wheel 50 rotates at a second speed (V2) lower than the first speed (V1). The controller 61 selectively switches between the first control mode and the second control mode, and while the piston 11 reciprocates between the bottom dead center and the top dead center, the first control mode and the second control mode are switched. Is switched at least once. That is, switching between the first control mode and the second control mode is performed at least once in one cycle.

  FIG. 5 shows the relationship between the change in the motor current supplied to the electric motor 20 under the control of the controller 61 and the change in the position of the piston 11. Hereinafter, changes in the motor current and the piston position during execution of the driving operation will be described, and the change in the position of the driver blade 30 will also be clarified.

  When the push lever 62 shown in FIG. 1 is pushed and the trigger lever 63 is operated, the driving operation is disclosed. The stop control is executed at the end of the previous driving operation. Therefore, at the start of the driving operation, the piston 11 is in the intermediate position, and the tip 30a (FIGS. 2 and 3) of the driver blade 30 is in the standby position.

  As shown in FIG. 4, when the push lever 62 is pushed in and the trigger lever 63 is operated, the first signal output from the push lever switch 62a and the second signal output from the trigger switch 63a are controlled by the controller. 61 is input. The controller 61 to which these signals are input controls the electric motor 20 in the first control mode. Specifically, the controller 61 starts supplying motor current to the electric motor 20 so that the wheel 50 rotates at the first speed (V1) that is the normal speed (point A in FIG. 5). Then, the wheel 50 rotates at the first speed (V1), the driver blade 30 is pushed up, and the piston 11 rises from the intermediate position toward the top dead center (point a → b in FIG. 5). Then, as the piston 11 rises, the pressure in the piston chamber 12 and the pressure accumulating chamber 13 increases. As a result, the load of the electric motor 20 gradually increases, and the motor current also gradually increases (point A → point B in FIG. 5).

  Thereafter, when the piston 11 reaches the top dead center and the engagement between the final pin 52b and the final rack 32b is released, the piston 11 moves from the top dead center toward the bottom dead center (b in FIG. 5). From point to point c), the driver blade 30 is lowered. When the engagement between the final pin 52b and the final rack 32b is released, the load of the electric motor 20 is reduced, so that the motor current is also reduced (point B → point C in FIG. 5).

  Thereafter, the controller 61 switches the control mode of the electric motor 20 from the first control mode to the second control mode when a predetermined time (t1) elapses after the piston 11 starts moving toward the bottom dead center. In other words, the controller 61 switches the control mode of the electric motor 20 from the first control mode to the second control mode while the piston 11 is moving from the top dead center toward the bottom dead center. As a result, the motor current supplied to the electric motor 20 further decreases (point D → point E in FIG. 5). In FIG. 5, for comparison, the motor current when the first control mode is continued is indicated by a broken line extending from the point D to the right side.

  That is, the controller 61 reduces the rotational speed of the wheel 50 from the first speed (V1) to the second speed (V2) while the piston 11 is moving from the top dead center toward the bottom dead center.

  Next, the controller 61 switches the control mode of the electric motor 20 from the second control mode to the first control mode after the piston 11 reaches bottom dead center. In other words, the controller 61 returns the control mode of the electric motor 20 to the first control mode when a predetermined time (t2) elapses after the piston 11 reaches the bottom dead center. As a result, the motor current supplied to the electric motor 20 increases (point F → point G in FIG. 5). That is, the controller 61 increases the rotational speed of the wheel 50 from the second speed (V2) to the first speed (V1) when a predetermined time (t2) has elapsed since the piston 11 reached the bottom dead center. When the piston 11 reaches the bottom dead center, the first pin 52a is not re-engaged with the first rack 32a, and the driver blade 30 is not started to be pushed up. This is apparent from the fact that the position of the piston 11 is constant for a while after the piston 11 reaches the bottom dead center (point c → point d in FIG. 5). That is, the controller 61 switches the control mode again after the piston 11 reaches the bottom dead center and before the first pin 52a is re-engaged with the first rack 32a, so that the rotation speed of the wheel 50 is increased. Increase.

  Thereafter, when the first pin 52a is reengaged with the first rack 32a, a load is applied to the electric motor 20, and the motor current increases (point H → point I in FIG. 5). Next, as the wheel 50 rotates, the driver blade 30 is pushed up, and the piston 11 starts moving from the bottom dead center toward the top dead center (point d → point e in FIG. 5). Then, as the piston 11 moves up, the pressure in the piston chamber 12 and the pressure accumulating chamber 13 increases, the load on the electric motor 20 gradually increases, and the motor current also gradually increases (point I → point J in FIG. 5).

  The electric motor 20 is substantially in a no-load state from when the engagement between the final pin 52b and the final rack 32b is released until the first pin 52a and the first rack 32a are re-engaged. In other words, the wheel 50 idles. Therefore, during the period, the motor current changes as the control mode is switched, but the change is not proportional. That is, the motor current is constant in each of the section from the point C to the point D, the section from the point E to the point F, and the section from the point G to the point H in FIG.

  As described above, in the driving machine 1 according to the present embodiment, the wheel 11 is rotated at the relatively high first speed (V1), and the piston 11 is moved from the bottom dead center (the first intermediate position) to the top dead center. After the piston 11 reaches the top dead center, the rotational speed of the wheel 50 is changed to a relatively low second speed (V2). In other words, after the engagement between the final pin 52b and the final rack 32b is released, the rotational speed of the wheel 50 is temporarily reduced. In other words, the rotational speed of the wheel 50 is temporarily reduced while the piston 11 is moving from the top dead center to the bottom dead center. As a result, the time (T1) required for the first pin 52a to re-engage with the first rack 32a after the engagement between the last pin 52b and the last rack 32b is reduced from the top dead center. It becomes longer than the time (T2) required to move to the dead point. Therefore, before the piston 11 reaches the bottom dead center (before the driver blade 30 reaches the lowest point), the first pin 52a is re-engaged with the first rack 32a, and the piston 11 and the driver blade 30 are lowered. Will not be hindered. Thus, in the present embodiment, the idle running time of the wheel 50 is adjusted by the control of the electric motor 20 (control of the motor current), and the driver blade 30 is provided on the wheel 50 before reaching the lowest point. The situation where the pin 52 and the rack 32 provided on the driver blade 30 are engaged is avoided. Further, since the decrease in the rotation speed of the wheel 50 is temporary, the continuous hitting speed does not decrease.

  The time (T1) can be made longer than the time (T2) by temporarily stopping the rotation of the wheel 50 while the piston 11 is moving from the top dead center to the bottom dead center. . That is, the second control mode includes a control in which the electric motor 20 is temporarily stopped and the rotation speed of the wheel 50 is temporarily set to 0 (zero). In other words, the second speed (V2) includes 0 (zero).

  In the present embodiment, switching between the first control mode and the second control mode is performed based on the elapse of a predetermined time (t1, t2). However, it is also possible to detect the position of the piston 11 based on the detection result of the position sensor 65 shown in FIG. 4 and switch between the first control mode and the second control mode based on this. Further, it is possible to detect that the piston 11 has reached the top dead center based on a change in motor current accompanying a load change of the electric motor 20. Furthermore, for example, it can be detected that the piston 11 has reached the bottom dead center by an impact sensor. Therefore, the position of the piston 11 can be detected based on detection results of various sensors, and switching between the first control mode and the second control mode can be performed based on the detection results.

(Second Embodiment)
Hereinafter, another example of the embodiment of the present invention will be described in detail with reference to the drawings. However, the driving machine according to the present embodiment is different from the driving machine 1 according to the first embodiment only with respect to the switching timing of the control mode of the electric motor 20, and the other points are common. Therefore, only differences from the driving machine 1 according to the first embodiment will be described below. In addition, the same reference numerals are used for the components already described, and redundant description is omitted.

  The controller 61 included in the driving machine according to the present embodiment controls the electric motor 20 in the first control mode to move the piston 11 to the top dead center side, and before the piston 11 reaches the top dead center, The control mode of the motor 20 is switched from the first control mode to the second control mode. Therefore, as shown in FIG. 6, the motor current decreases before the piston 11 reaches the top dead center (point B → point C in FIG. 6). Therefore, the rotational speed of the wheel 50 decreases before the piston 11 reaches top dead center (V1 → V2). As a result, the time required for the piston 11 to reach the top dead center after the stopper 40 can be supplied to the injection passage 9 is reduced to the injection passage 9 after the stopper 40 can be supplied to the injection passage 9. The time required for the stopper 40 to be actually supplied can be made longer. That is, the loading time of the stopper 40 can be ensured.

  In order to supply the stopper 40 to the injection passage 9, it is necessary to move the tip 30a of the driver blade 30 above the head 40a of the stopper 40. In other words, the stopper 40 can be supplied to the injection passage 9 after the tip 30 a of the driver blade 30 passes through the head 40 a of the stopper 40. Therefore, the stopper 40 is from when the tip 30a of the driver blade 30 passes the head 40a of the stopper 40 until the driver blade 30 starts to descend, that is, until the piston 11 reaches top dead center. It is necessary to complete the loading.

  Therefore, in the driving machine according to the present embodiment, the control mode of the electric motor 20 is changed from the first control mode to the second control mode before the piston 11 moving toward the top dead center reaches the top dead center. And the loading time of the stopper 40 is secured.

  In FIG. 6, for comparison, the motor current when the first control mode is continued is indicated by a broken line. Further, in this embodiment in which switching from the first control mode to the second control mode is executed before the piston 11 reaches top dead center, the piston 11 continues to rise even after switching to the second control mode. . Therefore, the motor current also increases in the section from point C to point D in FIG. Thereafter, when the piston 11 reaches top dead center, the electric motor 20 becomes substantially unloaded, and the motor current decreases again (point D → point E in FIG. 6). Subsequent changes in the motor current are substantially the same as those in the first embodiment.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, either the speed at the time of hoisting from the bottom dead center to the standby position, the speed at the time of hoisting from the top dead center to the bottom dead center, or both of them are waited by the second control mode of the present invention. By performing at a lower speed than the hoisting speed in the first control mode from the position to the top dead center, it is possible to select a rotation region in which driving and heat radiation are balanced when the electric motor 20 is driven during hoisting. become. This is particularly preferable in that the effect of reducing the thermal load of the heat generating components such as the motor and the switching element is obtained when the operator continuously performs the driving operation.

DESCRIPTION OF SYMBOLS 1 Driving machine 2 Housing 3 Cylinder case 4 Motor case 5 Handle 7 Connection part 8 Nose part 9 Injection passage 10 Cylinder 11 Piston 12 Piston chamber 13 Accumulation chamber 15 Damper 20 Electric motor 21 Output shaft 30 Driver blade 30a Tip 32 Rack 32a First 1 rack 32b 2nd rack (final rack)
40 Stopper 40a Head 41 Magazine 50 Wheel 51 Drive shaft 52 Pin 52a First pin 52b Second pin (final pin)
60 Battery 61 Controller 62 Push lever 62a Push lever switch 63 Trigger lever 63a Trigger switch 64 Inverter circuit 65 Position sensor

Claims (8)

A wheel driven to rotate by an electric motor;
A plurality of pins provided along the circumferential direction of the wheel on the wheel;
A piston housed in a reciprocating manner in a cylinder;
A driver blade that reciprocates integrally with the piston;
A plurality of racks provided on the driver blade along the axial direction of the driver blade;
A control unit for controlling the electric motor,
When the wheel is driven to rotate, the pin and the rack are sequentially engaged, the driver blade is pushed up, the piston moves to the top dead center side,
When the engagement between the pin and the rack is released, the piston moves to the bottom dead center side, and the driver blade descends,
The control unit is configured to control the electric motor so that the wheel rotates at a first speed as a control mode of the electric motor, and a second speed at which the wheel is slower than the first speed. A second control mode for controlling the electric motor to rotate at
Driving machine. The control unit performs switching between the first control mode and the second control mode at least once while the piston reciprocates once between a bottom dead center and a top dead center.
The driving machine according to claim 1. The control unit changes a duty ratio of a motor current supplied to the electric motor according to the control mode.
The driving machine according to claim 2. The control unit controls the electric motor in the first control mode to move the piston to the top dead center side, and after the piston reaches the top dead center, the control mode of the electric motor is changed to the first control mode. Switching from the control mode to the second control mode;
The driving machine according to any one of claims 1 to 3. The plurality of pins include a first pin and a second pin that is farthest from the first pin in the rotational direction of the wheel,
The control unit switches the control mode of the electric motor from the first control mode to the second control mode after the piston has reached top dead center, thereby engaging the second pin with the rack. The time required for the first pin and the rack to be engaged after being released is longer than the time required for the piston to move from top dead center to bottom dead center.
The driving machine according to claim 4. The control unit controls the electric motor in the first control mode to move the piston to the top dead center side, and before the piston reaches the top dead center, the control mode of the electric motor is changed to the first control mode. Switching from one control mode to the second control mode,
The driving machine according to any one of claims 1 to 3. The controller can supply a stopper to the injection passage by switching the control mode of the electric motor from the first control mode to the second control mode before the piston reaches top dead center. The time required for the piston to reach top dead center is longer than the time required for supplying the stopper to the injection passage until the stopper is supplied to the injection passage. ,
The driving machine according to claim 6. The second control mode includes control for temporarily stopping the electric motor and temporarily setting the rotation speed of the wheel to 0 (zero).
The driving machine according to any one of claims 1 to 7.

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