WO2023021693A1

WO2023021693A1 - Electric driver device

Info

Publication number: WO2023021693A1
Application number: PCT/JP2021/030608
Authority: WO
Inventors: 貴之高橋; 慎司森
Original assignee: 株式会社バンガードシステムズ
Priority date: 2021-08-20
Filing date: 2021-08-20
Publication date: 2023-02-23
Also published as: JPWO2023021693A1

Abstract

An electric driver device 1 comprises: a driver motor 311 that tightens or loosens a screw by causing an output shaft 312 to rotate; a pressing-force shaft 413 that is disposed on the line of extension of the rotational centerline of the output shaft 312; and a pressing-force motor 411 that imparts, to the pressing-force shaft 413, a force for pressing the driver motor 311 in a direction along the rotational centerline. Due to this configuration, the tightening or loosening of a screw can be performed smoothly.

Description

Electric driver device

The present invention relates to an electric driver device.

A device as shown in Patent Document 1 is known as a device for screwing or loosening screws on a work. Patent Literature 1 describes a screw loosening device in which an electric driver unit provided with a rotary drive motor is linearly driven vertically by an elevating motor. It also describes that the driver bit connected to the output shaft of the rotary drive motor is pressed downward by a spring.

JP-A-2021-53768

In the screw loosening device described in Patent Document 1, it is possible to loosen the screw while pressing the screw using a spring and an elevating motor. It is difficult to regulate the pressure. Further, in the pressing by the lifting motor, since the pressing force is applied from a side position of the electric driver unit, it is inevitable that the pressing force is applied in an oblique direction to the axial direction of the output shaft of the screw or the rotary drive motor. . As a result, an unexpected load is applied to the screw or screw thread, and there is a risk that the screw will be crushed or other abnormalities will occur. In particular, when the size of the screw is very small or when the screw is made of easily deformable material, such a problem is likely to occur.

An object of the present invention is to provide an electric driver that can smoothly tighten or loosen screws.

The present invention provides a driver motor for tightening or loosening a screw by rotating an output shaft, a pressing shaft arranged on an extension line of the rotation center line of the output shaft, and a screw for the driver with respect to the pressing shaft. A first aspect of the present invention provides an electric driver device including a pressing motor that applies a force that presses the motor in a direction along the rotation center line.

According to the electric driver device of the first aspect, since the pressing shaft is arranged on the extension line of the rotation center line of the output shaft of the driver motor, screw tightening or screw loosening is performed by the output shaft of the driver motor. A pressing force can also be applied to the screw in the direction of the center line, so that the screw can be smoothly tightened or loosened.

In the electric driver device of the first aspect, the pressing shaft is connected to the output shaft of the pressing motor, and the output shaft is rotated by the driving of the pressing motor, so that the pressing shaft moves to the rotation center axis. A configuration in which it is possible to move straight along the direction may be adopted as a second aspect.
According to the electric driver device of the second aspect, the rotational driving force of the pressing motor can act as a pressing force on the driver motor.

In the electric driver device of the first or second aspect, a driver bit is connected to the output shaft of the driver motor, and the pressing motor is connected to the driver motor on the side where the driver bit is connected. may be arranged on the extension line of the rotation center line on the opposite side to the third aspect.
According to the electric driver device of the third aspect, the driver motor and the pressing motor can be arranged on a straight line, and the installation space in the width direction can be reduced.

In the electric driver device according to any one of the first to third aspects, a first circuit board provided with a circuit for driving the driver motor and a circuit for driving the pressing motor are provided. and a cable connecting the first circuit board and the second circuit board, wherein the first circuit board is driven by the pressing motor to drive the second circuit board. A first connector for connecting one end side of the cable to the first circuit board, which moves relative to the circuit board along the direction of the rotation center line, is provided on the first circuit board. A second connector provided near the side facing the second circuit board and the side opposite to the side facing the second circuit board for connecting the other end side of the cable to the second circuit board; A configuration may be adopted as a fourth mode in which the first circuit board is provided in the vicinity of the side facing the first circuit board and the side opposite to the first circuit board.

According to the electric driver device of the fourth aspect, it is possible to reduce the bending of the cable due to the movement of the first circuit board, thereby reducing the deterioration and damage of the cable, the first connector, and the second connector. be able to.

The electric driver device according to any one of the first to fourth aspects includes a case member that houses the driver motor, and the case member is capable of housing another driver motor after removing the driver motor. A fifth aspect may employ a configuration in which the position of the output shaft does not change when the other driver motor is attached compared to when the driver motor is attached.

According to the electric driver device of the fifth aspect, even if the driver motor is replaced with another driver motor of a different size, the position of the output shaft does not change, so the position of the driver bit does not change. Therefore, when the electric driver device is attached to the robot arm, there is no need to perform readjustment due to replacement of the driver motor.

The figure which showed the external appearance of the electric driver apparatus which concerns on one Embodiment. 2(A) is a perspective view and FIG. 2(B) is a side view showing the appearance of an electric driver unit of an electric driver device according to an embodiment; FIG. FIG. 2 is a diagram schematically showing the configuration of an electric driver unit of the electric driver device according to one embodiment; 1 is a block diagram showing the configuration of an electric driver device according to one embodiment; FIG. FIG. 4 is a diagram for explaining a screw tightening operation using the electric driver device according to one embodiment; The figure which showed the control flow at the time of the screw tightening operation|movement using the electric driver apparatus which concerns on one Embodiment. FIG. 4 is a diagram for explaining a screw loosening operation using the electric driver device according to one embodiment; The figure which showed the control flow at the time of the screw loosening operation|movement using the electric driver apparatus which concerns on one Embodiment. FIG. 2 is a diagram showing the configuration of a cable that connects two circuit boards in the electric driver device according to one embodiment; FIG. 9A is a configuration diagram according to one embodiment, and FIG. 9B is a configuration diagram according to a comparative example. 4A and 4B are diagrams each showing a state in which two types of driver motors are attached to the electric driver device according to the embodiment; FIG. The block diagram which showed the structure of the electric driver apparatus which concerns on a modification.

An electric driver device 1 according to an embodiment of the present invention will be described below.
FIG. 1 is a diagram showing an appearance of an electric driver device 1. FIG. The electric driver device 1 is composed of a controller 11 and an electric driver unit 12 . The communication line 110 connects the controller 11 and the electric driver unit 12 and is used for data communication between them. The electric driver unit 12 includes a base portion 21 , a driver portion 31 mounted on the base portion 21 , and a pressing portion 41 . The driver bit 51 is connected to the driver portion 31, has a tip portion engaged with a screw, and is used for screw tightening and screw loosening operations.

2A and 2B are diagrams showing the appearance of the electric driver unit 12. FIG. 2A is a perspective view, and FIG. 2B is a side view.
The base portion 21 is configured by a rectangular plate-like member, and has support

portions

212, 213, 214, and 215 provided so as to protrude from the plate-like member. A driver portion 31 and a pressing portion 41 are provided along the longitudinal direction of the base portion 21 .

The driver portion 31 is provided between the support portion 212 and the support portion 213. A driver motor (described later) is provided inside a case member that constitutes the driver portion 31, and the tip side of the output shaft 312 of the driver motor is provided. A driver bit 51 is connected to .
The pressing portion 41 is provided at a position opposite to the side to which the driver bit 51 is connected with respect to the driver portion 31 and is provided between the supporting portion 214 and the supporting portion 215 . A pressing motor (described later) is provided inside a case member that constitutes the pressing portion 41 . The output shaft 412 of the pressing motor in the pressing portion 41 is engaged with the pressing shaft 413 .

A circuit board 315 is attached to the upper surface of the driver section 31 (the surface opposite to the base section 21 side). A circuit board 415 is attached so as to span the upper surface of the support portion 213 and the upper surface of the support portion 214 .

Circuit boards

315 and 415 will be described later.

FIG. 3 is a diagram schematically showing the configuration of the electric driver unit 12. As shown in FIG. A stepping motor is used as the driver motor 311 provided inside the driver section 31 in this embodiment. Further, the pressing motor 411 provided inside the pressing portion 41 also uses a stepping motor in this embodiment.

The output shaft 312 of the driver motor 311 passes through openings provided in the case member of the driver section 31 and the support section 212 , and the tip of the output shaft 312 is connected to the driver bit 51 . The driver bit 51 can be replaced with another driver bit according to the type of screw to be screwed or loosened. When the driver motor 311 is driven, the output shaft 312 rotates, and the driver bit 51 connected to the output shaft 312 also rotates. As the driver bit 51 rotates, the screw engaged with the tip of the driver bit 51 rotates, enabling the workpiece to be tightened or loosened.

The output shaft 412 of the pressing motor 411 in the pressing portion 41 passes through an opening provided in the case member of the pressing portion 41 and the support portion 214 , and the tip side of the output shaft 412 is engaged with the pressing shaft 413 . are doing. The pressing shaft 413 passes through the opening of the support portion 213 and has a distal end connected to the driver portion 31 .

The engagement portion between the output shaft 412 and the pressing shaft 413 constitutes a ball screw. moves straight in the direction of arrow M in FIG. The linear movement of the pressing shaft 413 causes the connected driver portion 31 to linearly move in the arrow M direction. The case member that constitutes the driver portion 31 is configured to be movable along a guide rail formed on the base portion 21 in the direction of arrow M, for example, so that it can move straight. When the driver portion 31 moves straight, the driver motor 311 , the output shaft 312 , and the driver bit 51 move straight together with the driver portion 31 .

In this embodiment, as will be described later, when the driver motor 311 is driven to tighten or loosen the screw on the work, the pressing motor 411 is driven to rotate the pressing shaft 413 . In principle, a pressing force is applied to press the driver portion 31 in the direction of arrow P, which is the pressing direction, and the driver portion 31 is pressed.

In FIG. 3, the center line C is drawn by extending the rotation center axis of the output shaft 312 of the driver motor 311 . In this embodiment, the centerline of the driver bit 51, the centerline of the pressing shaft 413, and the rotation centerline of the output shaft 412 of the pressing motor 411 are aligned with the centerline C. As shown in FIG.

Since the rotation center line of the output shaft 312 of the driver motor 311 (or the center line of the driver bit 51) and the center line of the pressing shaft 413 are aligned with each other, an oblique pressing force is applied to the output shaft 312. Instead, the pressing force is applied only in the direction of the center line of the output shaft 312 . As a result, a force can be applied to press or pull out the screw parallel to the depth direction of the screw hole. Therefore, unnecessary loads applied to the screws and screw holes can be reduced. As a result, the possibility of causing an abnormality such as crushing of the screw or thread is reduced. In particular, when the size of the screw is extremely small, or when the material of the screw or screw hole is easily deformed, how parallel to the depth direction of the screw hole is to push (or pull out) the screw. However, according to the present embodiment, screw tightening and screw loosening can be performed smoothly even in such a case.

Further, although the screw holes are not necessarily formed in the vertical direction, according to the present embodiment, a pressing force can be applied to the screw precisely in parallel with the depth direction of the screw hole. Smooth screw tightening and screw loosening can be achieved even if the direction of pull-out is different from the direction of gravity.

The center of the pressing shaft 413 does not necessarily have to be exactly aligned with the center line C (the central axis of the output shaft 312), but it is said that a force parallel to the axial direction is applied to the output shaft 312 as much as possible. From a viewpoint, it is preferable to provide the pressing shaft 413 at a position where the center line C passes through the interior of the pressing shaft 413 .

FIG. 4 is a block diagram showing the configuration of the electric driver device 1. As shown in FIG.
The electric driver unit 12 includes a driver motor 311 , a pressing motor 411 , an encoder 421 and an input/output control circuit 121 . The encoder 421 is provided in the pressing portion 41 and detects the rotational position of the rotor of the pressing motor 411 (that is, the rotational position of the output shaft 412).

The input/output control circuit 121 communicates with the controller 11 via the communication line 110 . In addition, the input/output control circuit 121 outputs a drive signal and a stop signal to the driver motor 311 and the pressing motor 411 according to the signal from the controller 11 . The input/output control circuit 121 also receives a detection signal from the encoder 421 and transmits rotational position information of the pressing motor 411 to the controller 11 . Based on this rotational position information, the controller 11 detects the position of the driver bit 51 . The input/output control circuit 121 also monitors the output current of the driver motor 311 and transmits current value information to the controller 11 . Based on this current value information, the controller 11 detects the torque of the driver motor.

The input/output control circuit 121 is specifically provided in the electric driver unit 12 as the circuit board 315 and the circuit board 415 in FIG. Of the configuration of the input/output control circuit 121, the configuration related to input/output of signals to the driver motor 311 is provided on the circuit board 315, and the configuration related to input/output of signals to the pressing motor 411 and the encoder 421 is provided on the circuit board 415. be provided.

The controller 11 is composed of a processor, memory, keyboard, display, etc. The controller 11 shown in FIG. 4 shows a functional configuration realized by those hardware configurations of the computer. The functional configuration of the controller 11 will be described below.

The driver motor control section 111 of the controller 11 outputs a drive signal and a stop signal to the electric driver unit 12 to control driving and stopping of the driver motor 311 . The pressing motor control section 112 outputs a drive signal and a stop signal to the electric driver unit 12 to control driving and stopping of the pressing motor 411 .

The driver bit position detector 113 acquires rotational position information (based on the detection result of the encoder 421) of the pressing motor 411 from the electric driver unit 12, and detects the current position of the driver bit 51 in the direction along the center line C. To detect. The position of the driver bit 51 changes with the position of the driver portion 31 (the position in the direction along the center line C in FIG. 3). A position where the driver part 31 has moved toward the pressing part 41 is defined as an initial position, and the position of the driver bit 51 is determined by the amount of movement in the straight direction (direction M, that is, the direction along the center line C) from the initial position. (position of tip) is calculated. That is, if the amount of movement of the pressing shaft 413 in the straight direction per rotation of the output shaft 412 by the pressing motor 411 is known, the rotational position information of the pressing motor 411 (the number of rotations from the initial position) by the encoder 421 ), the position of the driver bit 51 can be calculated. Driver bit position detector 113 outputs the calculated position information of driver bit 51 to calculator 115 .

The torque detection unit 114 acquires the output current value information of the driver motor 311 from the electric driver unit 12 and estimates the torque value of the driver motor 311 . Since the output current value increases as the output torque of the driver motor 311 increases, the output torque can be estimated. Torque detector 114 outputs the estimated torque value information to calculator 115 .

The calculation unit 115 acquires the position information of the driver bit 51 from the driver bit position detection unit 113 and the torque value information from the torque detection unit 114, and controls the driving of the driver motor 311 and the pressing motor 411. It determines whether it is necessary to change the driving state, and outputs an instruction signal to the driver motor control section 111 and the pressing motor control section 112 .

The storage unit 116 stores information for calculating and estimating values by the driver bit position detection unit 113, the torque detection unit 114, and the calculation unit 115, and determining whether or not an operation is necessary. For example, the storage unit 116 stores the rotational position of the pressing motor 411 at the initial position, the output shaft 412 of the pressing motor 411, and the information necessary for calculating the position of the driver bit 51 in the driver bit position detection unit 113. It stores information such as the amount of movement of the pressing shaft 413 in the rectilinear direction per one rotation. Storage unit 116 also stores coefficients and the like for estimating the torque value from the output current value in torque detection unit 114 . The storage unit 116 also stores various types of information for determining drive control of the driver motor 311 and the pressing motor 411 in the calculation unit 115 . For example, it stores threshold information for judging the completion of screw tightening based on the torque value, and predetermined position information for judging the start and completion of screw tightening and screw loosening according to the position of the driver bit 51 .

The input unit 117 is a device such as a keyboard and a mouse that can be input by the user, and allows the user to input information to be stored in the storage unit 116 . The display unit 118 is a display device, and displays the operation status of the input unit 117, the state of the electric driver unit 12, and the like so that the user can visually recognize it.

FIG. 5 is a diagram for explaining a screw tightening operation using the electric driver device 1, and FIG. 6 is a diagram showing a control flow during the screw tightening operation using the electric driver device 1. FIG. The operations described below are realized by storing a program for realizing the operations shown in the flowchart of FIG.
Before starting the screw tightening operation, the pressing motor control section 112 of the controller 11 outputs a driving start signal to the electric driver unit 12 to start the driving of the pressing motor 411 to move the driver section 31 straight. Move to the initial position.

The initial position may be the side where the driver part 31 is closest to the pressing part 41 in the movable range. For example, when the driver unit 31 reaches the end of the movement range on the side closer to the pressing unit 41, it cannot move any further. can be detected by the driver bit position detector 113 . The position information detected by the driver bit position detection unit 113 in the initial position state is stored in the storage unit 116 .

In FIG. 5A, the driver bit 51 is moved in the direction of arrow P from the initial position and the pressing motor 411 is driven so as to approach the workpiece W, and the screw 53 is moved to the predetermined position. It shows a state in which it is adsorbed to the tip. In FIG. 5A, the predetermined position indicates that the tip of the driver bit 51 is at a distance L1 from the work W surface.

For example, if the distance between the tip portion of the driver bit 51 at the initial position and the surface of the workpiece W is stored in advance in the storage unit 116, the calculation unit 115 calculates the difference between the distance and the distance L1 to obtain the pressing force. Driver bit 51 can be moved to the position shown in FIG.
The controller 11 is in a standby state until the screw 53 is sucked as shown in FIG. ).

For example, an input signal to the controller 11 from the outside (such as a screw feeder) recognizes that the screw 53 has been sucked. As means for attracting the screw 53 to the driver bit 51, a method of magnetizing the driver bit 51 and attracting the screw 53 by magnetic force can be employed.

Subsequently, the pressing motor control section 112 of the controller 11 outputs a drive signal to the electric driver unit 12 so as to move the driver bit 51 in the direction of arrow P in FIG. 5, and drives the pressing motor 411 (step S602). ). Subsequently, the driver motor control unit 111 outputs a driving signal for rotating the driver bit 51 in the direction of tightening the screw 53, outputs it to the electric driver unit 12, and drives the driver motor 311 (step S603). ).
By controlling the driving of the pressing motor 411 and the driver motor 311 in this manner, the screw 53 approaches the work W while rotating, reaches the surface of the work W, and is then tightened to the work W. I'm getting lost.

FIG. 5(B) shows a state in which the screw 53 has reached the surface of the work W, and FIG. 5(C) shows a state in which the screw 53 is being tightened into the work W. Even in the states of FIGS. 5B and 5C, the pressing motor 411 continues to be driven, so that the driver bit 51 continues to receive a force that presses the screw 53 in the direction of the workpiece W (the direction of the arrow P). . Therefore, even if the screw 53 is tightened into the work W by the rotation of the driver bit 51, the tip of the driver bit 51 can continue to be engaged with the screw 53 without being separated from the screw 53, and can continue to apply rotational force. .

In the states of FIGS. 5(B) and 5(C), the torque detection unit 114 of the controller 11 acquires the output current value of the driver motor 311 to continue detecting the torque value. The calculation unit 115 compares the torque value detected by the torque detection unit 114 with a threshold value stored in advance in the storage unit 116 . Then, it is determined whether or not the screw 53 has reached the screw tightening completion position by determining whether or not the torque value exceeds the threshold value (step S605).

FIG. 5(D) shows a state in which the screw 53 has been tightened to the screw tightening completion position. In this state, the screw 53 and the driver bit 51 cannot continue to rotate, so the torque of the driver motor 311 increases and the output current increases. As a result, the torque value detected by the torque detector 114 exceeds the threshold. If the torque value exceeds the threshold (step S605: YES), the position of the driver bit 51 is detected by the driver bit position detector 113 (step S606). If the detected torque value is equal to or less than the threshold (step S605: NO), torque detection is continued while the driver motor 311 and the pressing motor 411 are driven.

The calculation unit 115 compares the position information of the driver bit 51 detected by the driver bit position detection unit 113 with the allowable range information of the position of the driver bit 51 at the completion of screw tightening stored in the storage unit 116 in advance. (step S607).
If the position of the driver bit 51 is within the allowable range, it is determined that screw tightening has been completed normally (step S607: YES), and the screw tightening operation is terminated. to reverse driving, and the driver bit 51 is returned to the initial position. FIG. 5(E) shows a state in which screw tightening is completed and the driver bit 51 is moved to the initial position.

If the position of the driver bit 51 is not within the allowable range (step S607: NO), it is determined that screw tightening has not been completed normally, and inspection processing is performed by the user (step S608). A conceivable cause is that the screw 53 becomes unable to rotate before it reaches the state shown in FIG.

In the screw tightening operation as described above, the pressing force in the direction of the arrow P by the pressing motor 411 is applied by the pressing shaft 413, but the center line of the pressing shaft 413 and the center line C of the driver bit 51 do not coincide. (the center line C in FIG. 5) and coincides with the center line of the screw 53 as well. Therefore, no force is applied to the screw 53 in a direction other than the direction of the center line, so that the screw can be smoothly tightened.

FIG. 7 is a diagram for explaining a screw loosening operation using the electric driver device 1, and FIG. 8 is a diagram showing a control flow during the screw loosening operation using the electric driver device 1. FIG. The operations described below are realized by storing a program for realizing the operations shown in the flowchart of FIG.
As in the case of the screw tightening operation, before starting the screw tightening operation, the pressing motor control section 112 of the controller 11 outputs a drive start signal for causing the electric driver unit 12 to start driving the pressing motor 411. , the driver unit 31 is moved straight to the initial position.

FIG. 7(A) shows the state where the driver bit 51 is waiting at the initial position. FIG. 7A shows that the initial position is a position where the tip of the driver bit 51 is at a distance L2 from the work W surface. In this state, the pressing motor control section 112 of the controller 11 outputs a driving signal to the electric driver unit 12 so as to move the driver bit 51 in the direction of the arrow P, thereby driving the pressing motor 411 (step S801). By driving the pressing motor 411, the driver bit 51 approaches the screw 53 tightened in the work.

While the driver bit is moving, the driver bit position detector 113 detects the position of the driver bit (step S802). Based on the position information detected by the driver bit position detector 113, the calculator 115 determines whether the tip of the driver bit 51 has reached a predetermined position near the screw 53 (step S803). .

FIG. 7(B) shows a state in which the driver bit 51 has reached a predetermined position near the screw 53 . FIG. 7(B) shows that the predetermined position near the screw 53 is a position moved in the arrow P direction by a distance L3 from the initial position. Information indicating the distance L3 is stored in the storage unit 116 in advance. Based on the position information detected by the driver bit position detection unit 113 and the information on the distance L3 stored in the storage unit 116, the calculation unit 115 determines whether the tip of the driver bit 51 reaches a predetermined position near the screw 53. It is possible to determine whether or not

When it is determined that the driver bit 51 has not reached the predetermined position (step S803: NO), the operations of steps S802 and S803 are repeated. When it is determined that the driver bit 51 has reached the predetermined position (step S803: YES), the driver motor control unit 111 moves the screw 53 in the loosening direction (opposite to the screw tightening described with reference to FIGS. 5 and 6). direction) to drive the driver motor 311 (step S804). At this time, as in the case of screw tightening control, the driver bit 51 is caused to start an operation for attracting the screw 53 .

The pressing motor control unit 112 continues control to drive the pressing motor 411 (step S805). The driver bit 51 approaches the screw 53 while rotating, and the tip of the driver bit 51 contacts the head of the screw 53 and engages with a cross recess (or slot) formed in the head of the screw 53. . FIG. 7(C) shows a state where the tip of the driver bit 51 is engaged with the cross recess of the head of the screw 53 .

7(B) to FIG. 7(C), the driver bit 51 is controlled by the driver motor controller 111 so that the tip of the driver bit 51 smoothly engages the screw 53. It is preferable that the rotational torque applied to 51 be smaller than the rotational torque for screw loosening in FIGS.

Similarly, when the state shown in FIG. 7B shifts to the state shown in FIG. It is preferable that the rotational torque applied is smaller than that in the states shown in FIGS. 7A to 7B. By doing so, the moving speed of the driver bit 51 in the direction of arrow P when shifting from the state of FIG. 7B to the state of FIG. , and the tip of the driver bit 51 can be smoothly engaged with the screw 53 .

In steps S804 and S805, the screw 53 fastened to the workpiece W is loosened by starting control to drive the driver motor 311 and the pressing motor 411 with a suitable torque for screw loosening. FIG. 7(D) shows a state in which the screw 53 is loosened and is rising with respect to the work W surface.
When the screw 53 is loosened, the pressing force in the direction of the arrow P with which the driver bit 51 presses the screw 53 by driving the pressing motor 411 is such that the screw 53 does not prevent the screw 53 from rising with respect to the surface of the work W. The pressing motor control unit 112 controls the torque of the pressing motor 411 so that the magnitude of .

The driver bit position detection unit 113 detects the position of the driver bit while the screw is being loosened as shown in FIG. 7(D) (step S806). Based on the positional information detected by the driver bit position detector 113, the calculator 115 determines whether or not the tip of the driver bit 51 reaches a predetermined position before the lower end of the screw 53 exits the workpiece W. It judges (step S807).

FIG. 7(E) shows a state in which the lower end of the screw 53 has reached a predetermined position before coming out of the workpiece W. The predetermined position may be set regardless of the characteristics of the screw or the tightening conditions, or may be set regardless of the screw's structural characteristics such as the length of the screw, the pitch of the screw thread, the strength of the screw, and the diameter of the screw, or the rotational speed and the pressing force. It may be determined depending on control parameters. As an example, it is preferable to set the position at which the screw 53 reaches a position where about two more threads of the thread of the screw 53 have not escaped from the workpiece W as the predetermined position. In short, the predetermined position should be determined so that the screw can be loosened reliably and smoothly, as will be described later.

FIG. 7(E) shows that the predetermined position in this case is the position where the tip of the driver bit 51 is separated from the initial position by the distance L4 in the arrow P direction. Information indicating the distance L4 is stored in the storage unit 116 in advance. Based on the position information detected by the driver bit position detection unit 113 and the information on the distance L4 stored in the storage unit 116, the calculation unit 115 positions the tip of the driver bit 51 at the predetermined position shown in FIG. 7(E). It can be determined whether or not it has reached.

When it is determined that the driver bit 51 has not reached the predetermined position (step S807: NO), the operations of steps S806 and S807 are repeated. When determining that the driver bit 51 has reached the predetermined position (step S807: YES), the pressing motor control section 112 outputs a drive signal for reversing the rotation direction of the pressing motor 411 (step S808). .

That is, in the state of FIG. 7(E), the rotation direction of the pressing motor 411 is reversed. Since the driver bit 51 continues to rotate in the same direction, loosening of the screw 53 continues. FIG. 7(F) shows a state in which the screw 53 is entirely removed from the workpiece W and the loosening of the screw is completed. 7(E), the direction of rotation of the pressing motor 411 is reversed, so that the driver bit 51 no longer exerts a pressing force in the direction of arrow P. A force acts to move in the opposite direction. As a result, the screw 53 can be smoothly pulled out from the work W without fluttering due to the screw 53 being pressed in the surface direction of the work W when the screw has been loosened as shown in FIG. 7(F). .

The calculation unit 115 determines whether or not the driver bit 51 has reached the position shown in FIG. 7(F) based on the position information detected by the driver bit position detection unit 113 (step S809). If not reached (step S809: NO), the process of step S809 is repeated while the driver motor 311 and the pressing motor 411 are driven. If it has reached (step S809: YES), the pressing motor control section 112 performs control to return the driver bit 51 to the initial position, and ends the process. In this case, the driver motor control section 111 may perform control to stop driving the driver motor.

In the screw loosening operation as described above, the pressing force in the direction of the arrow P by the pressing motor 411 is applied by the pressing shaft 413 in the same manner as in the screw tightening operation. The centerline C of the bit 51 matches (the centerline C in FIG. 7), and the centerline of the screw 53 also matches. Therefore, no force is applied to the screw 53 in a direction other than the direction of the center line, and the screw can be loosened smoothly.
7(C) to (E), since the screw 53 is loosened while being pressed, the tip of the driver bit 51 continues to engage with the screw 53, and the driver bit 51 and the screw 53 do not separate from each other. is carried out smoothly.

FIG. 9 is a diagram showing a configuration of a cable that connects two circuit boards in the electric driver unit 12 of the electric driver device 1. As shown in FIG. FIG. 9A is a configuration diagram according to this embodiment, and FIG. 9B is a configuration diagram according to a comparative example.
In FIG. 9, the members denoted by the same reference numerals as those in FIGS. 1 to 3 are the same members as those shown in FIGS.

The circuit board 315 is attached to the driver section 31 as described above, and is provided with a circuit for inputting/outputting signals to/from the driver motor 311 . As described above, the circuit board 415 is attached across the upper surface of the support portion 213 and the upper surface of the support portion 214, and is provided with a circuit for inputting/outputting signals to/from the pressing motor 411 and the encoder 421. there is Since the circuit board 315 is attached to the driver portion 31 , it moves integrally with the driver portion 31 in the arrow M direction when the driver portion 31 is moved in the arrow M direction by driving the pressing motor 411 . Since the circuit board 415 is fixed to the base portion 21, its position relative to the base portion 21 does not change.

As can be seen from FIG. 2A, the

circuit boards

315 and 415 are rectangular (rectangular in this embodiment) plate-like members. As shown in FIGS. 2 and 9, the

circuit boards

315 and 415 are installed so that one sides of each rectangle face each other. As shown in FIG. 9A, each of the

circuit boards

315 and 415 is provided with

connectors

315a and 415a near the side opposite to the side facing the other circuit board.

Also, the

connectors

315a and 415a are provided near the corners of the respective circuit boards. Although only one connector 315a of the circuit board 315 is shown in FIG. 9A, this is the connector 315a provided at the front corner, and there is also a connector 315a at the rear corner. is provided. Similarly, the connector 415a of the circuit board 415 is also provided at the front corner and the back corner.

Both ends of the cable 317 are connected to

connectors

315a and 415a. The cable 317 is configured by bundling a plurality of wires such as signal lines and power lines. The circuit board 315 side of the cable 317 is installed along the side surface of the base section 21 through the space between the driver section 31 and the support section 212 from the connector 315a. A portion of the cable 317 installed along the side surface of the base portion 21 is accommodated in a groove portion 217 provided on the side surface of the base portion 21 . The groove portion 217 is closed by a lid member in a state in which a portion of the cable 317 is accommodated.

The circuit board 415 side is provided extending from the groove 217 to the connector 415a through the space between the support 214 and the support 215 . The cable 317 is provided on the back side in the same manner as that provided on the front side in FIG. 9A, and is connected to

connectors

315a and 415a provided on the back side. The groove portion 217 is also provided on the opposite side surface of the base portion 21 .

FIG. 9(B) is a diagram showing a configuration according to a comparative example. Each of the

circuit boards

315 and 415 is provided with

connectors

315b and 415b near the side facing the other circuit board. Both ends of the cable 317A are connected to the

connectors

315b and 415b. The cable 317A in FIG. 9B is shorter than the cable 317 in FIG. 9A, and the space required for installation of the cable 317A is smaller than in FIG. 9A.

During the screw tightening or screw loosening operation, the driver unit 31 moves straight in the direction of the arrow M, so the distance between the

circuit boards

315 and 415 also changes. In the case of the configuration shown in FIG. 9B, the length of the cable 317A is set so that the cable 317A is not subject to tension even when the distance between the

circuit boards

315 and 415 is increased. When the distance between the

circuit boards

315, 415 is reduced, the cable 317A is greatly bent. Due to the repeated linear movement of the driver portion 31, the cable 317A repeatedly deforms between the extended state and the bent state, which causes a durability problem. Also, the connecting portions of the cable 317A with the

connectors

315b and 415b at both ends are affected by the deformation of the cable 317A and easily damaged.

In FIG. 9(A),

connectors

315a and 415a are provided in the vicinity of the opposite sides of the

circuit boards

315 and 415 with respect to FIG. 9(B) to connect cables 317. Cable 317 is longer than cable 317A in FIG. 9B, and cable 317 can be installed in a sufficiently wide space near

connectors

315a and 415a. Therefore, the bending of the cable 317 due to the linear movement of the driver section 31 is smaller than that of the cable 317A shown in FIG. Alternatively, the

connectors

315a and 415a are less likely to be damaged.

10A and 10B are diagrams showing states in which two types of driver motors are attached to the electric driver unit 12 of the electric driver device 1. FIG.
As shown in FIG. 10A, a driver motor 311 is provided inside the case member forming the driver section 31 .

Depending on the size of the screw used when screwing or loosening the workpiece. It is necessary to prepare an electric driver unit having a driver motor capable of generating a torque suitable for the screw size. In such a case, in this embodiment, the driver motor 311 of the electric driver unit 12 can be replaced.

FIG. 10(B) shows a state where the driver motor 311 provided in the driver section 31 of the electric driver unit 12 is removed and the driver motor 311A is newly installed. The driver motor 311A is a motor capable of generating torque higher than that of the driver motor 311, and is therefore larger in size than the driver motor 311. As shown in FIG. As shown in FIGS. 10A and 10B, the driver motor 311A has a radial length D2 longer than the radial length D1 of the driver motor 311, which is longer than D1.

In the present embodiment, as shown in FIG. 10(A), the driver motor 311 is mounted in the case member of the driver unit 31 so that a predetermined space is secured around the driver motor 311 (upper and lower in the drawing). 311 is attached.
Therefore, as shown in FIG. 10(B), it is possible to mount a driver motor 311A having a large size inside the case member of the driver section 31 .

In this embodiment, the position of the output shaft 312 does not change between when the driver motor 311 is mounted in the case member of the driver section 31 and when the driver motor 311A is mounted. That is, the distance E from the bottom surface of the base portion 21 to the center of the output shaft 312 is the same regardless of which of the

driver motors

311 and 311A is attached. Although not shown in FIG. 10, the position of the support portion 212 of the output shaft 312 in the depth direction is also the same as in FIGS. 10(A) and 10(B).

Here, the ideal output torque characteristics of the motor used may differ depending on the screw size, composition, tightening conditions, etc. According to the above configuration, when the electric driver unit 12 is attached to the robot arm, the positional relationship of the driver bit 51 with respect to the robot arm does not change regardless of which of the

driver motors

311 and 311A having different torque characteristics is used. Therefore, even when the torque of the driver motor is changed, there is no need to adjust the positional relationship between the robot arm and the driver bit 51 . Therefore, using the electric driver device 1, it is possible to cope with different tightening conditions and the like by simply replacing the driver motor as appropriate.

For example, if a different electric driver unit is used to change the torque of the driver motor, the position of the driver bit with respect to the robot arm may change. , readjustment due to torque change of the driver motor becomes unnecessary.

[Modification]
Various modifications can be made to the embodiments described above. Examples of these modifications are shown below. In addition, the embodiment described above and the modifications described below may be appropriately combined.

(1) Although the encoder 421 is provided in the pressing portion 41 in the above embodiment, the encoder may be provided in the driver portion 31 . Also, the torque detection unit 114 of the controller 11 detects the torque of the driver motor 311 , but may detect the torque of the pressing motor 411 .
FIG. 11 is a block diagram showing the configuration of an electric driver device 1A according to a modification. In FIG. 11, the components denoted by the same reference numerals as those in FIG. 4 are the same as those in FIG. 4, so description thereof will be omitted.

A controller 11A of an electric driver device 1A shown in FIG. 11 differs from the controller 11 shown in FIG. 4 in that it includes a driver motor torque detector 114A and a pressing motor torque detector 114B. Also, the electric driver unit 12A differs from the electric driver unit 12 shown in FIG. 4 in that an encoder 321 is provided.
The encoder 321 of the electric driver unit 12A is provided in the driver section 31 and detects the rotational position of the rotor of the driver motor 311 (that is, the rotational position of the output shaft 312).

A driver motor torque detector 114A of the controller 11A acquires the output current value information of the driver motor 311 from the electric driver unit 12A and estimates the torque value of the driver motor, similarly to the torque detector 114 of FIG. do. The pressing motor torque detector 114B acquires the output current value information of the pressing motor 411 from the electric driver unit 12A and estimates the torque value of the pressing motor 411 .
11, the input/output control circuit 121 transmits the rotation position information of the driver motor 311 based on the detection signal from the encoder 321 and the current value information obtained by monitoring the output current of the pressing motor 411 to the controller 11A. Send.

The driver bit position detection unit 113 of the controller 11A acquires the rotational position information of the driver motor 311 (based on the detection result of the encoder 321) in addition to the rotational position information of the pressing motor 411 from the electric driver unit 12A. Accordingly, the position information of the driver bit 51 can be calculated based on the rotational position information of the pressing motor 411 and the position information of the driver bit 51 can be calculated based on the rotational position information of the driver motor 311 . Calculation of the position information of the driver bit 51 based on the rotational position information of the driver motor 311 can be calculated based on the rotational position information and the pitch information of the thread of the screw 53 pre-stored in the storage unit 116 . can.

According to the electric driver device 1A according to the modified example described above, it is possible to change the screw tightening or screw loosening control operation in the electric driver device 1 according to the above-described embodiment.
In the screw tightening control of the above embodiment, whether or not the screw 53 has reached the screw tightening completion position in steps S604 and S605 of FIG. However, it may be performed depending on whether the torque value of the pressing motor 411 exceeds the threshold value.

As shown in FIG. 5(D), when the screw 53 is tightened to the screw tightening completion position, the pressing shaft 413 cannot continue to move straight, so the output current of the pressing motor 411 increases. As a result, the torque value detected by the pressing motor torque detection unit 114B exceeds the threshold, so it can be determined that the screw 53 has reached the screw tightening completion position.

In the above-described embodiment, the driver bit position detector 113 detects whether or not the position of the driver bit 51 is within the allowable range when it is determined that screw tightening is completed in steps S606 and S607 of FIG. The positional information of the driver bit 51 based on the rotational positional information of the pressing motor 411 is used. This determination may be made based on the position information of the driver bit 51 based on the rotation position information of the driver motor 311 (according to the detection result of the encoder 321).

In this case, the driver bit position detection unit 113 acquires rotational position information of the driver motor 311 based on the detection result of the encoder 321 . Then, the position of the driver bit 51 is estimated from the number of rotations of the driver motor 311 from the state of FIG. This can be compared with information on the permissible range of the position of the driver bit 51 at the time of completion of screw tightening stored in advance in 116 .

5B (the state where the lower end of the screw 53 reaches the surface of the workpiece W) can be determined based on the position information of the driver bit 51 based on the rotation position information of the pressing motor 411. can. Further, it may be determined that the state shown in FIG. 5B is reached from fluctuations in the torque value calculated by the driver motor torque detection section 114A or the pressing motor torque detection section 114B.

Further, in the screw loosening control of the above-described embodiment, in step S807 of FIG. 8, the determination that the driver bit 51 has reached the position shown in FIG. The position information of the driver bit 51 based on the rotation position information of the pressing motor 411 is used. This determination may be made based on the position information of the driver bit 51 based on the rotation position information of the driver motor 311 (according to the detection result of the encoder 321).

In this case, the driver bit position detection unit 113 acquires rotational position information of the driver motor 311 based on the detection result of the encoder 321 . Then, the position of the driver bit 51 is estimated from the number of rotations of the driver motor 311 from the state of FIG. 51 has reached the position shown in FIG. 7(E).

The state of FIG. 7C (the state in which the driver bit 51 is engaged with the screw 53) can be determined based on the positional information of the driver bit 51 based on the rotational positional information of the pressing motor 411. . Further, it may be determined that the state shown in FIG. 7C is obtained from fluctuations in the torque value calculated by the driver motor torque detection section 114A or the pressing motor torque detection section 114B.

Further, in the above-described embodiment, in step S809 of FIG. 8, the determination that the driver bit 51 has reached the position shown in FIG. The position information of the driver bit 51 based on the rotational position information of . This determination may be made based on the position information of the driver bit 51 based on the rotation position information of the driver motor 311 (according to the detection result of the encoder 321).

In this case, the driver bit position detection unit 113 acquires rotational position information of the driver motor 311 based on the detection result of the encoder 321 . 7(C) (or the state of FIG. 7(E)) and information on the number of threads of the screw 53 pre-stored in the storage unit 116. By estimating the position of the bit 51, it can be determined that the driver bit 51 has reached the position shown in FIG. 7(F).

(2) In the above-described embodiment, the controller 11 includes functional components such as the driver motor control unit 111, the pressing motor control unit 112, the driver bit position detection unit 113, the torque detection unit 114, the calculation unit 115, the storage unit 116, and the like. However, these functional configurations may be included in the electric driver unit 12 . For example, the circuit board 315 or the circuit board 415 of the electric driver unit 12 is provided with a CPU, a memory, etc., and includes a driver motor control section 111, a pressing motor control section 112, a driver bit position detection section 113, a torque detection section 114, and a calculation section. 115, storage unit 116 and the like.

(3) In the above-described embodiment, part of the cable 317 is housed in the groove 217 provided on the side surface of the base 21, but the cable 317 is It is not necessary to provide a groove for storage if it is prevented from contacting or catching on other members. For example, a plurality of portions of the cable 317 may be fixed to the base portion 21 with pin-shaped members or the like.

(4) In the above-described embodiment, as shown in FIG. The motor 311 may be replaced with a smaller (lower torque) driver motor than the driver motor 311 .

(5) In the above-described embodiments, stepping motors are used as the driver motor and the pressing motor. motor, etc.) may be used.

1, 1A: electric driver device, 11, 11A: controller, 12, 12A: electric driver unit, 21: base portion, 31: driver portion, 41: pressing portion, 51: driver bit, 53: screw, 110: communication Line 111: Driver motor control unit 112: Pressing motor control unit 113: Driver bit position detection unit 114: Torque detection unit 114A: Driver motor torque detection unit 114B: Pressing motor torque detection unit 115: Arithmetic unit, 116: Storage unit, 117: Input unit, 118: Display unit, 121: Input/output control circuit, 212, 213, 214, 215: Support unit, 217: Groove, 311: Driver motor, 312: Output shaft 315: Circuit board 315a: Connector 321: Encoder 317: Cable 411: Pressing motor 412: Output shaft 413: Pressing shaft 415: Circuit board 415a: Connector 421: Encoder W :work.

Claims

a driver motor for tightening or loosening screws by rotating the output shaft;
a pressing shaft arranged on an extension of the rotation center line of the output shaft;
An electric driver device comprising: a pressing motor that applies a force to the pressing shaft to press the driver motor in a direction along the rotation center line.
The pressing shaft is connected to an output shaft of the pressing motor, and the pressing shaft can be linearly moved in a direction along the rotation center line by driving the pressing motor to rotate the output shaft. The electric driver device according to claim 1.
A driver bit is connected to the output shaft of the driver motor, and the pressing motor is on an extension line of the rotation center line at a position opposite to the side where the driver bit is connected with respect to the driver motor. The electric driver device according to claim 1 or 2, wherein the electric driver device is arranged in the
a first circuit board provided with a circuit for driving the driver motor;
a second circuit board provided with a circuit for driving the pressing motor;
A cable connecting the first circuit board and the second circuit board,
The first circuit board is driven by the pressing motor to move relative to the second circuit board along the rotation center line direction,
A first connector for connecting one end of the cable to the first circuit board is positioned near the side of the first circuit board facing the second circuit board and the side opposite to the second circuit board. provided in
A second connector for connecting the other end of the cable to the second circuit board is located near the side of the second circuit board opposite to the side facing the first circuit board. The electric driver device according to any one of claims 1 to 3, provided at a position.
comprising a case member in which the driver motor is housed,
the case member is capable of housing another driver motor by removing the driver motor,
The electric driver device according to any one of claims 1 to 4, wherein when the other driver motor is attached, the position of the output shaft does not change from when the driver motor is attached.