JP2023090201A - fastening device - Google Patents

Abstract

To provide a fastening device that can fasten a plurality of types of nuts having different sizes.SOLUTION: A fastening device includes a gripping part 1, a movement mechanism 3, a rotating mechanism and a control unit. The gripping part 1 can grip a plurality of types of nuts. The movement mechanism 3 can position the gripping part 1 relative to a nut. The rotating mechanism rotates the gripping part 1 gripping a nut about a rotation axis of the nut. The control unit controls the gripping part 1, the movement mechanism 3 and the rotating mechanism.SELECTED DRAWING: Figure 7

Description

The present disclosure relates to fastening devices.

Conventionally, fastening devices for fastening nuts are known. For example, Japanese Patent Application Laid-Open No. 2002-18737 discloses a wrench that grips a nut between a pair of fitting surfaces in order to facilitate fitting with a nut and apply it to an automatic machine. A configuration is disclosed in which one longitudinal distance at the mating surfaces of the two is longer than the other longitudinal distance.

Japanese Unexamined Patent Application Publication No. 2002-18737

With the wrench disclosed in Japanese Unexamined Patent Application Publication No. 2002-18737 as a fastening device, it is difficult to fasten a plurality of types of nuts having different sizes. Further, Japanese Patent Application Laid-Open No. 2002-18737 suggests incorporating the wrench into a fastening device such as an automatic machine, but does not disclose a specific configuration of the fastening device.

An object of the present disclosure is to provide a fastening device capable of fastening multiple types of nuts of different sizes.

A fastening device according to the present disclosure includes a gripper, a moving mechanism, a rotating mechanism, and a controller. The gripping portion can grip a plurality of types of nuts. The moving mechanism can position the gripper with respect to the nut. The rotating mechanism rotates the gripping portion that grips the nut about the rotating shaft of the nut. The control section controls the grip section, the moving mechanism, and the rotating mechanism.

According to the above, it is possible to obtain a fastening device capable of fastening a plurality of types of nuts having different sizes.

1 is a schematic cross-sectional view of a fastening device according to Embodiment 1; FIG. 2 is a schematic plan view of a portion of the fastening device shown in FIG. 1; FIG. FIG. 2 is a partial schematic diagram of the fastening device shown in FIG. 1; FIG. 2 is a functional block diagram of the fastening device shown in FIG. 1; It is a partial plane schematic diagram for demonstrating the modification of the fastening device shown in FIG. 2 is a flowchart for explaining a nut fastening method using the fastening device shown in FIG. 1; It is a plane schematic diagram for demonstrating the fastening method of a nut. It is a plane schematic diagram for demonstrating the fastening method of a nut. It is a plane schematic diagram for demonstrating the fastening method of a nut. It is a plane schematic diagram for demonstrating the fastening method of a nut. It is a plane schematic diagram for demonstrating the fastening method of a nut. It is a plane schematic diagram for demonstrating the fastening method of a nut. It is a plane schematic diagram for demonstrating the fastening method of a nut. FIG. 9 is a schematic plan view for explaining a nut fastening method using the fastening device according to the second embodiment; FIG. 9 is a schematic plan view for explaining a nut fastening method using the fastening device according to the second embodiment; FIG. 9 is a schematic plan view for explaining a nut fastening method using the fastening device according to the second embodiment; FIG. 9 is a schematic plan view for explaining a nut fastening method using the fastening device according to the second embodiment; FIG. 9 is a schematic plan view for explaining a nut fastening method using the fastening device according to the second embodiment; FIG. 9 is a schematic plan view for explaining a nut fastening method using the fastening device according to the second embodiment;

Embodiments of the present disclosure will be described below. In addition, the same reference numerals are given to the same configurations, and the description thereof will not be repeated.

Embodiment 1.
<Structure of fastening device>
FIG. 1 is a schematic cross-sectional view of a fastening device according to Embodiment 1. FIG. FIG. 2 is a partial schematic plan view of the fastening device shown in FIG. 13 is a partial schematic diagram of the fastening device shown in FIG. 1. FIG. 4 is a functional block diagram of the fastening device shown in FIG. 1. FIG.

As shown in FIGS. 1 to 4, the fastening device mainly includes a gripping portion 20, a moving mechanism 30, a rotating mechanism 40, a device base 6, and a control portion 10. As shown in FIGS. The gripping portion 20 can grip a plurality of types of nuts N. As shown in FIG. The moving mechanism 30 moves the gripping portion 20 relative to the nut N. As shown in FIG. The moving mechanism 30 can position the grip part 20 with respect to the nut N. As shown in FIG. The rotating mechanism 40 rotates the gripping portion 20 gripping the nut N about the rotating shaft 70 of the nut N. As shown in FIG. The device base 6 supports the grip part 20 , the moving mechanism 30 and the rotating mechanism 40 . The control unit 10 controls the grasping unit 20 , the moving mechanism 30 and the rotating mechanism 40 . The fastening device is arranged so as to face the work target member 90 including the nut N. As shown in FIG.

The gripping portion 20 includes a spanner portion 1 and a drive portion 2 as shown in FIGS. The spanner portion 1 grips the nut N. FIG. 2 is a schematic plan view showing the spanner portion 1, the driving portion 2, and the radial moving portion 3. FIG. The spanner portion 1 includes a pair of arms 1a, a central pin 1b and a spring 1c. A set of arms 1a are arranged so as to extend in one direction and be aligned with each other. Near the center of a pair of arms 1a, these two arms 1a are connected by a central pin 1b. A pair of arms 1a are capable of pivoting about a center pin 1b.

A plurality of nut contact portions 1aa and 1ab, which are portions that come into contact with the nut N, are formed on the arm 1a on one side, ie, the distal end side of the arm 1a as viewed from the center pin 1b. The arm 1a shown in FIG. 2 is formed with two nut contact portions 1aa and 1ab. The grip portion 20 includes a plurality of nut contact portions 1aa and 1ab respectively corresponding to a plurality of types of nuts N. As shown in FIG. As shown in FIG. 2, the distance between the two nut contact portions 1aa is greater than the distance between the two nut contact portions 1ab when the tip side (upper side in FIG. 2) of the pair of arms 1a is open. . That is, the size of the nut N gripped by the nut contact portion 1aa is larger than the size of the nut N gripped by the nut contact portion 1ab. In the arm 1a, the nut contact portion 1aa and the nut contact portion 1ab are connected by an inclined surface that is inclined with respect to the surface of the nut contact portion 1aa. The nut contact portion 1aa and the nut contact portion 1ab may be connected by a plane perpendicular to the surface of the nut contact portion 1aa so that the nut contact portion 1aa and the nut contact portion 1ab are adjacent to each other. Since the two nut contact portions 1aa and 1ab are formed in this manner, the spanner portion 1 can grip two types of nuts N having different sizes.

A spring 1c is installed so as to connect a pair of arms 1a on the opposite side (root side) to the tip end side where the nut contact portions 1aa and 1ab are formed when viewed from the center pin 1b. A spring 1c urges the arms 1a so that the root sides of the pair of arms 1a are brought closer to each other. Therefore, the wrench portion 1 is in a state in which the distal end side is open as shown in FIG. 2 in a no-load state.

The drive unit 2 is a device for opening and closing the arm 1a of the spanner unit 1. As shown in FIG. The drive portion 2 includes a wedge portion 2a, a shaft 2b and a shaft drive portion 2c. A shaft 2b is connected to the wedge portion 2a. A shaft drive portion 2c is connected to the side of the shaft 2b opposite to the side connected to the wedge portion 2a. The wedge portion 2a is arranged at a position facing the root side of the pair of arms 1a.

The shaft driving portion 2c moves the wedge portion 2a by moving the shaft 2b in the direction indicated by the arrow 71 in FIG. By inserting the wedge portion 2a between the pair of arms 1a, the wedge portion 2a presses the root side of the arm 1a, and the pair of arms 1a turns about the center pin 1b. As a result, the tip sides of the pair of arms 1a move toward each other. That is, when the wedge portion 2a contacts the base side of the arm 1a, the tip side of the pair of arms 1a moves in the closing direction. On the other hand, when the wedge portion 2a is moved to the position where it does not come into contact with the base side of the pair of arms 1a, that is, the position shown in FIG. Moving. As a result, the tip side of the pair of arms 1a moves in the opening direction. In this manner, the drive unit 2 switches between a state in which the wrench unit 1 grips the nut N and a state in which the nut N is not gripped by opening and closing the arm 1a of the spanner unit 1 .

Any configuration can be adopted as the configuration of the shaft driving portion 2c. The shaft is arranged such that the wedge portion 2a moves radially between a first position where the wedge portion 2a contacts the root side of the arm 1a and a second position where the wedge portion 2a does not contact the root side of the arm 1a. The drive unit 2c operates. For example, a direct-acting actuator can be used as the shaft driving portion 2c, and it is preferable to use an air cylinder in consideration of cost. When a single-acting push-in air cylinder is used as the shaft driving portion 2c, when air as a working fluid is pressure-fed to the shaft driving portion 2c, the cylinder extends and the wedge portion 2a moves to the first position. When the air as the working fluid is removed from the shaft driving portion 2c, the cylinder is contracted and the wedge portion 2a is moved to the second position.

The shape of the arm 1a and the wedge portion 2a is such that when the nut contact portions 1aa and 1ab of the arm 1a have the same width as the width across flats of the nut N, the arm 1a does not rotate around the axis 2b, and as a result, the wedge It is decided that the part 2a is mechanically stopped. The movement amount (stroke) of the shaft driving portion 2c is set so that each of the plurality of nut contact portions 1aa and 1ab can come into contact with the target nut N. For example, in a state in which the nut contact portions 1aa and 1ab are in contact with the nut N, the distance from the position of the wedge portion 2a when the width of the tip portion of the pair of arms 1a is relatively narrow to the second position is The amount of movement is determined so that the wedge portion 2a can move.

The movement mechanism 30 includes a radial movement portion 3 and an axial movement portion 5 . The radial moving portion 3 moves the spanner portion 1 in the radial direction perpendicular to the rotating shaft 70 . The radial moving part 3 moves the wrench part 1 toward the nut N from the radial direction in order to grip the nut N, and adjusts the radial position of the wrench part 1 with respect to the nut N according to the type of the nut N. decide. The radial movement portion 3 moves the spanner portion 1 in the radial direction between a position where the spanner portion 1 can contact the nut N and a position where the spanner portion 1 does not contact the nut N. Specifically, the radial movement portion 3 includes a radial movement base 3a and a movement portion 3b. A grasping portion 20 is fixed to the moving portion 3b. The moving part 3b has a flat plate shape as shown in FIGS. A spanner portion 1 and a driving portion 2 are fixed to the upper surface of the moving portion 3b. More specifically, the center pin 1b of the spanner portion 1 is fixed to the upper surface of the moving portion 3b. Further, the shaft driving portion 2c of the driving portion 2 is fixed to the upper surface of the moving portion 3b.

The radial movement base 3a movably supports the movement portion 3b. The moving part 3b is arranged on the radial movement base 3a. The moving part 3b can move in the direction indicated by the arrow 71 in FIG. 2 relative to the radial movement base 3a. Any configuration can be adopted as the configuration for moving the moving portion 3b, and for example, a direct acting actuator can be used. A mechanism for moving the moving portion 3b may be set arbitrarily to the stop position of the moving portion 3b within the moving range (prescribed stroke) of the moving portion 3b, and for example, a direct-acting electric actuator can be used. In this case, the prescribed stroke refers to the position from the position (retracted position) where the moving portion 3b and the spanner portion 1 in the radial direction moving portion 3 are most retracted toward the axial direction moving base 5a side to the position where the spanner portion 1 clamps the nut N. It is the allowable stroke of the electric actuator selected from the distance (movement amount of the moving part 3b) to the position (advance position) to which the moving part 3b moves so as to reach. Radial moving portion 3 moves spanner portion 1 based on a control signal transmitted from control portion 10 . Therefore, the moving mechanism 30 can determine the position of the spanner portion 1 with respect to the nut N according to the type of the nut N as described later by operating the radial direction moving portion 3 . That is, the moving mechanism 30 moves the spanner portion 1 so that one of the plurality of nut contact portions 1aa and 1ab contacts the nut N. As shown in FIG.

The axial movement portion 5 includes an axial movement base 5a and a movement portion 5b. The axial movement base 5 a is fixed to the device base 6 . The device base 6 has, for example, a flat plate shape. The device base 6 supports the grip part 20 , the moving mechanism 30 and the rotating mechanism 40 . The axial movement base 5a is formed so as to protrude from the upper surface of the device base 6. As shown in FIG. The axial movement base 5a has, for example, a flat plate shape. The moving part 5b is movably connected to the axial movement base 5a. The moving part 5b has, for example, a flat plate shape. The moving part 5b is arranged to protrude from the surface of the axially moving base 5a. The moving part 5b is formed so as to extend along the surface of the device base 6. As shown in FIG. The moving part 5b is movable in the direction along the rotating shaft 70 of the nut N along the surface of the axially moving base 5a. A mechanism for moving the moving part 5b with respect to the axially moving base 5a can adopt any configuration. For example, an electric actuator may be used as the mechanism, or a configuration in which a rotating machine such as a motor and a ball screw are combined may be used. As the mechanism, it is sufficient that the moving portion 5b can be fixed at an arbitrary position in the axial direction with respect to the axially moving base 5a.

As shown in FIG. 1 , the gripping portion 20 is supported by the moving portion 5 b via the rotating mechanism 40 and the radial moving portion 3 . Therefore, the axial moving portion 5 can move the spanner portion 1 , the driving portion 2 , the radial moving portion 3 , and the rotary driving portion 4 in the axial direction along the rotation shaft 70 . That is, the axial movement portion 5 can move the spanner portion 1 of the grip portion 20 in the axial direction. The axial movement portion 5 of the movement mechanism 30 can change the position of the spanner portion 1 in the axial direction according to the operation of the rotation mechanism 40, which will be described later.

Here, when tightening and loosening the nut N, it is preferable to move the spanner portion 1 in the axial direction following the thread pitch of the nut N while holding the nut N between the spanner portions 1 . Therefore, the axial moving portion 5 has a floating function in the axial direction (vertical direction). As the floating function, a mechanism for mechanically adjusting the position of the moving portion 5b in the axial direction may be employed, or the position of the moving portion 5b may be adjusted following the thread pitch of the nut N under control from the control portion 10. Fine-tuning controls may also be employed. If such a floating function cannot be implemented in the axially moving portion 5, the work target member 90 is moved axially so that the relative height of the nut N with respect to the spanner portion 1 does not change according to tightening and loosening of the nut N. It is also possible to employ a mechanism that follows and moves the . Any configuration can be adopted as the configuration of the mechanism.

The rotating mechanism 40 is installed in the moving portion 5 b of the axial moving portion 5 . The rotation drive section 4 as the rotation mechanism 40 rotates (revolves) the spanner section 1 around the rotation shaft 70 . The rotary drive unit 4 mainly includes a motor 4a as an actuator, a motor fixing plate 4b, a worm 4d, a worm wheel 4e, and a worm wheel turning base 4f. A worm gear 4c is composed of the worm 4d and the worm wheel 4e. The motor fixing plate 4b and the worm wheel turning base 4f are fixed to the surface of the moving part 5b. A motor 4a is fixed to the motor fixing plate 4b. As the motor 4a, for example, a servomotor whose output torque can be controlled by the control unit 10 can be used. In the motor 4a, the control unit 10 controls the output torque so that the wrench portion 1 generates a tightening torque when the nut N is tightened. The worm 4d is fixed to the rotating shaft (not shown) of the motor 4a. Worm 4d is rotatable by motor 4a. The worm 4d is arranged so as to extend along the surface of the moving portion 5b. A screw structure is formed on the surface of the worm 4d.

A worm wheel 4e is arranged so as to contact the worm 4d. The worm wheel 4e has a plate-like shape. As shown in FIG. 3, the planar shape of the worm wheel 4e is fan-shaped. FIG. 3 is a schematic diagram of the worm wheel 4e viewed from the moving portion 5b side. A gear portion 4ea that meshes with the screw structure 4da (see FIG. 7) of the worm 4d is formed on the end surface of the worm wheel 4e that contacts the worm 4d. The worm wheel 4e is arranged to extend along the surface of the moving portion 5b. A worm wheel turning base 4f is arranged between the worm wheel 4e and the moving portion 5b. The worm wheel 4e is rotatably supported by a worm wheel turning base 4f.

As shown in FIGS. 1 and 3, a linear protrusion 4h having an arcuate planar shape is formed on the surface (back surface) of the worm wheel 4e facing the worm wheel turning base 4f. An arc-shaped groove 4i in which the linear projection 4h is arranged is formed on the surface of the worm wheel turning base 4f. The worm wheel 4e is rotatable around the rotating shaft 70 of the nut N while the linear projection 4h is guided by the groove 4i. That is, the worm wheel 4e turns about the rotation shaft 70 by rotating the worm 4d by the motor 4a. The linear projection 4h of the worm wheel 4e and the worm wheel turning base 4f having the groove 4i form a mechanism that defines the turning locus of the worm wheel 4e. The configuration of the mechanism is not limited to the configuration described above, and other configurations may be employed as long as the turning trajectory of the worm wheel 4e can be defined. For example, a groove 4i may be formed on the worm wheel 4e side, and a linear projection 4h may be formed on the worm wheel turning base 4f side. Further, instead of the linear projections 4h described above, a plurality of projections that are discretely arranged in an arc and that can be inserted into the grooves 4i may be formed. Further, the linear projection 4h may not be formed over the entire circumferential direction of the worm wheel 4e as shown in FIG. 3, and may be partially formed in the circumferential direction.

A radially moving portion 3 is fixed to the surface of the worm wheel 4e (the upper surface opposite to the back surface facing the worm wheel turning base 4f). That is, the radially moving base 3a of the radially moving portion 3 is fixed to the surface of the worm wheel 4e. A grasping portion 20 is supported by the radially moving portion 3 . Therefore, the rotating mechanism 40 can turn (rotate) the grasping portion 20 around the rotating shaft 70 . The rotation angle (turning angle) at which the gripping portion 20 is turned may be 60° or more or 120° or more when the nut N is a hexagonal nut, for example. In this case, for example, the spread angle of the worm wheel 4e as viewed from the rotating shaft 70 is set to 60° or more, more preferably 120° or more.

As shown in FIG. 4, the control section 10 is connected to an axial drive section controller 2d, a radial movement section controller 3c, a motor controller 4g and an axial movement section controller 5c. The axis drive section controller 2d is connected to the axis drive section 2c and controls the axis drive section 2c. The radial movement part controller 3c is connected to the radial movement base 3a and controls the movement of the movement part 3b. The motor controller 4g is connected to the motor 4a and controls the motor 4a. The axial movement part controller 5c is connected to the axial movement base 5a and controls the movement of the movement part 5b. The control unit 10 controls each device described above by transmitting control signals to each of the axial driving unit controller 2d, the radial movement unit controller 3c, the motor controller 4g, and the axial movement unit controller 5c. Specifically, the axis driving section controller 2d controls the movement direction and movement start timing of the wedge section 2a by controlling the axis driving section 2c. The radial moving portion controller 3 c controls the moving direction, moving amount, movement start timing, and the like of the moving portion 3 b in the radial moving portion 3 . The motor controller 4g controls the direction of rotation of the motor 4a, the timing of starting rotation, the amount of rotation, the output torque of the motor 4a, and the like. The axial movement section controller 5c controls the movement direction, movement start timing, movement amount, and the like of the movement section 5b of the axial movement section 5. FIG. The control unit 10 is, for example, a programmable controller (also called a programmable logic controller: PLC).

In the fastening device described above, two nut contact portions 1aa and 1ab are formed on the arm 1a of the spanner portion 1, but the number of nut contact portions may be three or more as shown in FIG. . FIG. 5 is a schematic partial plan view for explaining a modification of the fastening device shown in FIG. 1. FIG. In the spanner portion 1 shown in FIG. 5, an arm 1a is formed with three nut contact portions 1aa, 1ab, and 1ac. In this case, three different sizes of nuts N can be tightened or removed with the same fastening device. By forming a plurality of nut contact portions in this manner, a plurality of types of nuts N can be easily operated in the fastening device.

If three or more nut contact portions 1aa, 1ab, and 1ac are prepared in the wrench portion 1 as described above, the nut can be assembled with a fastening device having the same configuration without temporarily stopping production of the fastening device and replacing the equipment. A plurality of types of nuts N can be tightened or loosened according to the number of contact portions. However, in order to accommodate more kinds of nuts N, it is necessary to increase the length of the arm 1a in order to form a plurality of nut contact portions corresponding to the number of kinds of nuts N. When the length of the arm 1a is increased in this way, the arm 1a may interfere with a portion of the work target member 90 other than the nut N or other jigs. If such interference occurs, the workability of processing the nut N using the fastening device is reduced. Therefore, it is preferable to design the wrench portion 1 by determining the number of types of nuts N to be manipulated by considering the number of types of nuts N to be manipulated by a fastening device of a single configuration and the shape of the work target member 90 .

<fastening method>
FIG. 6 is a flow chart for explaining a nut fastening method using the fastening device shown in FIG. 7 to 12 are schematic plan views for explaining a nut fastening method. A method of fastening a nut using the fastening device shown in FIG. 1 will be described below. 7 to 12 show the spanner portion 1, driving portion 2, radial movement portion 3, worm wheel 4e and worm 4d of the fastening device.

First, in the fastening device shown in FIG. 1, which is an automatic nut fastening device, each unit constituting the fastening device is assumed to be placed at the origin position when the device is started at the start of production or when the device is stopped at the end of production. do. The origin position of each unit in the fastening device refers to, for example, the following arrangement. Regarding the driving portion 2, the wedge portion 2a is completely pulled out from the root side of the arm 1a, and the position where the shaft 2b is most retracted toward the shaft driving portion 2c is the origin position. The origin position of the wrench portion 1 is the position where the distal end side of the arm 1a is opened most by the restoring force of the spring 1c. Regarding the radial direction moving portion 3, the position where the moving portion 3b is most retracted toward the axial direction moving base 5a is the origin position. The origin position of the rotary drive unit 4 is the position at which the center of the outer peripheral portion of the worm wheel 4e in the circumferential direction coincides with the center of the fastening device. As for the axial moving part 5, the position where the moving part 5b is lowered to an arbitrary position (for example, the position closest to the device base 6) is the origin position.

The worm wheel 4e has a fan-shaped planar shape as shown in FIG. It is determined. Further, the arrangement of the fastening device is determined so that the center of the turning motion of the worm wheel 4e defined by the linear protrusions 4h and the grooves 4i of the worm wheel 4e overlaps with the rotating shaft 70. As shown in FIG.

As shown in FIG. 6, in the nut fastening method according to the present embodiment, first, a step (S1) of raising and lowering the wrench portion to the height of the nut is performed. In this step (S1), the axial moving portion 5 is operated to raise the moving portion 5b, thereby moving the spanner portion 1, the driving portion 2, the radial moving portion 3, and the rotary driving portion 4 to the position of the nut N. raise to When the height of the arm 1a of the spanner portion 1 reaches the same height as the height of the nut N to be tightened, the movement of the moving portion 5b is stopped. The nut N here is a hexagonal nut. In the step (S1), the work target member 90 is arranged at a position facing the fastening device as shown in FIG. The arrangement of the work target member 90 is determined so that the relative position of the nut N with respect to the device base 6 is a preset position.

Next, the step (S2) of inserting the spanner portion into the nut is performed. In this step (S2), as shown in FIG. 7, the spanner portion 1 is moved by the radial movement portion 3 so that the nut contact portion 1aa of the arm 1a of the spanner portion 1 reaches the position of the nut N. . The spanner portion 1 moves toward the nut N from a radial direction perpendicular to the rotating shaft 70 of the nut N. As for the movement amount (movement distance) for moving the wrench part 1, the movement amount of the wrench part 1 for each type of nut N is registered in the control part 10 of the fastening device in advance.

Since the wrench portion 1 approaches the nut N in the radial direction perpendicular to the rotating shaft 70 of the nut N, as shown in FIG. It is possible to easily operate the nut N on the work target member 90 where there is an object.

Next, the step (S3) of closing the arms of the spanner portion and clamping the nut is performed. In this step (S3), the shaft driving portion 2c of the driving portion 2 inserts the wedge portion 2a into the root side of the arm 1a. As a result, as shown in FIG. 8, the distance between the bases of the pair of arms 1a increases against the force of the spring 1c, and the distance between the ends of the pair of arms 1a narrows. That is, the tip side of the arm 1a is closed.

Next, the step (S4) of rotating the spanner portion while closing the arm of the spanner portion is performed. In this step (S4), after the arm 1a is closed until it clamps the nut N, the wedge portion 2a is inserted between the arms 1a by the shaft 2b to close the tip side of the arm 1a, and the motor 4a is operated. Rotate the worm wheel 4e.

Next, a step (S5) of determining whether the arm is completely closed is performed. In this step (S5), the wrench portion 1 is rotated in the direction of tightening the nut N about the rotation shaft 70 (see FIG. 1) of the nut N. As shown in FIG. Then, the wedge portion 2a is inserted between the arms 1a until the movement of the wedge portion 2a stops mechanically. Specifically, when the wedge portion 2a can be moved, it is determined as NO in the step (S5), and the process returns to the step (S4). On the other hand, when the wedge portion 2a cannot move, the two faces of the nut N are clamped by a pair of arms 1a as shown in FIG. As a result, YES is determined in step (S5).

Next, when it is judged as YES in the step (S5), the step (S6) of tightening the nut by turning the entire wrench portion while the arm is closed is performed. In this step (S6), as shown in FIG. 10, the nut N can be tightened by rotating the wrench portion 1 further in the direction in which the nut N is tightened by the rotary drive portion 4 .

At this time, the mechanism from the spanner portion 1 to the rotary drive portion 4 follows the movement of the nut N in the direction of the rotating shaft 70 by the axial movement portion 5 . That is, the moving mechanism 30 can change the position of the spanner portion 1 in the direction of the rotating shaft 70 according to the operation of the rotating mechanism 40 . Therefore, the function (floating function) of the moving mechanism 30 allows the wrench portion 1 to follow the movement (vertical movement) of the nut N in the direction of the rotating shaft 70 . Such a function can be realized, for example, by controlling the operation of the axial movement section 5 according to the rotation angle of the worm wheel 4 e in the rotation mechanism 40 by the control section 10 .

Next, a step (S7) of determining whether or not the nut N has reached a specified tightening torque is carried out. In this step (S7), it is determined whether or not the tightening torque of the nut N has reached an arbitrarily specified specified tightening torque. In the step (S7), the control unit 10 determines whether or not the tightening torque has reached the specified tightening torque, depending on whether the output torque of the motor 4a has reached a preset reference value, for example.

In the fastening device described above, a large number of mechanisms are interposed between the motor 4a, which is the power source, and the spanner portion 1, which is the driving portion. Therefore, the relationship between the output torque of the motor 4a and the tightening torque of the nut N may not be obtained simply by power calculation. Therefore, it is preferable to perform verification using an actual machine before tightening the nut N using the work target member 90 (product) whose tightening torque is uniquely determined. Specifically, it is preferable to confirm in advance the output torque of the motor 4a when securing the necessary tightening torque of the nut N with this fastening device, and to set the reference value.

If NO is determined in the step (S7), a step (S12) of determining whether the wrench portion has reached the turning limit angle is carried out. In this step (S12), it is determined whether or not the turning angle of the wrench portion 1, that is, the turning angle of the worm wheel 4e has reached a preset turning limit angle. Any method can be used for this determination. For example, the position of the worm wheel 4e is detected by a sensor or the rotation speed of the motor 4a is measured. You may judge whether it reached. The control of the steps (S7) and (S12) is performed by the control unit 10 shown in FIG. 4 controlling the motor controller 4g and the like. That is, in this fastening device, the control section 10 controls the operation of the rotating mechanism 40 according to the rotational torque when the grip section 20 rotates about the rotating shaft 70 of the nut N. As shown in FIG.

If the determination in step (S12) is NO, the processes after step (S6) are performed again. On the other hand, if the determination in step (S12) is YES, the step (S13) of opening the arm and releasing the nut is performed. In this step (S13), as shown in FIG. 11, the wedge portion 2a is extracted from between the pair of arms 1a by the shaft driving portion 2c, thereby increasing the distance between the tip portions of the pair of arms 1a. Enlarge, that is, open the arm 1a. As a result, the nut N is released from the spanner portion 1 .

Next, a step (S14) of rotating the spanner portion in the opposite direction is performed. In this step, the motor 4a of the rotary drive unit 4 is operated to rotate the worm wheel 4e. The direction of rotation of the motor 4a in step (S14) is opposite to the direction of rotation of the motor in step (S4). Therefore, the worm wheel 4e turns in a direction opposite to the turning direction in step (S4). The turning angle in step (S14) is, for example, 120° when the nut N is a hexagonal nut. As a result, as shown in FIG. 12, the wrench portion 1 is rotated counterclockwise from the position in step (S2). After that, the processes after the step (S3) are repeated until the judgment result in the step (S7) becomes YES.

If YES is determined in the step (S7), the step (S8) of completely opening the arm and releasing the nut is carried out. In this step (S8), as shown in FIG. 11, the wedge portion 2a is removed from between the pair of arms 1a by the shaft driving portion 2c, thereby reducing the distance between the tip portions of the pair of arms 1a. Enlarge, that is, open the arm 1a. As a result, the nut N is released from the spanner portion 1 .

After that, the step (S9) of pulling out the spanner portion from the nut is carried out. In this step (S9), the wrench portion 1 is pulled out from the nut N by moving the moving portion 3b of the radially moving portion 3 in a direction away from the nut N. As shown in FIG.

Next, a step (S10) of turning the spanner portion to its original position is performed. In this step (S10), the motor 4a of the rotary drive unit 4 is operated to rotate the worm gear 4c. The direction of rotation of the motor 4a in step (S10) is opposite to the direction of rotation of the motor in step (S4). Therefore, the worm wheel 4e turns in a direction opposite to the turning direction in step (S4). As a result, the spanner portion 1 returns to the position in step (S2).

Next, the step (S11) of returning the wrench portion to the lower height is performed. In this step (S11), the axial movement portion 5 is operated to lower the movement portion 5b (to move toward the device base side), thereby rotating the spanner portion 1, the drive portion 2, the radial movement portion 3, and the rotary drive. The part 4 is returned to the position at the start of step (S1). When step (S11) ends, the nut fastening method shown in FIG. 6 ends.

By doing so, the nut N can be tightened to any specified tightening torque by the tightening device according to the present embodiment. Further, when the nut N is loosened by the fastening device, the nut N can be loosened. Further, in this case, in step (S7), it is determined whether the nut N is sufficiently loosened, not whether the specified tightening torque has been reached. Specifically, for example, it is possible to determine whether or not the nut N is sufficiently loosened by determining whether or not the total number of revolutions of the motor 4a has reached a specified value.

7 to 12, for example, a nut N relatively smaller in size than the nut N shown in FIG. 7 as shown in FIG. It can be carried out. FIG. 13 is a schematic plan view for explaining a nut fastening method.

In this case, in the step (S2) described above, as shown in FIG. move 1. After that, the nut N can be tightened or loosened by performing the steps after the step (S3).

Thus, according to the fastening device described above, even if the size of the nut N (for example, the outer diameter) is different, it is possible to tighten or loosen the nut N with the same device. Further, the fastening device is configured by combining simple mechanisms, and operations such as tightening of the nut N can be realized by a device with a relatively low manufacturing cost. Moreover, it is possible to tighten the nut N with an arbitrary specified tightening torque or more. Therefore, it is possible to automatically tighten the nut N in the product using the fastening device.

<Action>
A fastening device according to the present disclosure includes a gripping portion 20 , a moving mechanism 30 , a rotating mechanism 40 and a control portion 10 . The gripping portion 20 can grip a plurality of types of nuts N. As shown in FIG. The moving mechanism 30 can position the gripping portion 20 with respect to the nut N. As shown in FIG. The rotating mechanism 40 rotates the gripping portion 20 gripping the nut N about the rotating shaft 70 of the nut N. As shown in FIG. The control unit 10 controls the grasping unit 20 , the moving mechanism 30 and the rotating mechanism 40 .

In this way, since a plurality of types of nuts N can be gripped by the gripping portion 20, a plurality of types of nuts N having different sizes can be tightened and fixed to the work target member 90 by a single fastening device, or can be removed from the work target member 90. It can be removed by loosening the nut N.

In the fastening device described above, the gripping portion 20 may include the spanner portion 1 and the driving portion 2 . The spanner portion 1 grips the nut N. The drive unit 2 switches between a state in which the wrench portion 1 grips the nut N and a state in which the nut N is not gripped by opening and closing the wrench portion 1 . The movement mechanism 30 may include a radial movement portion 3 and an axial movement portion 5 . The radial moving portion 3 moves the spanner portion 1 in the radial direction perpendicular to the rotating shaft 70 . The axial moving part 5 moves the spanner part 1 in the axial direction along the rotating shaft 70 .

In this case, the operation of gripping the nut N by the gripping portion 20 or releasing the nut N from the gripping portion 20 can be easily performed. Moreover, the position of the nut N with respect to the work target member can be easily adjusted by the moving mechanism 30 .

In the fastening device described above, the moving mechanism 30 may be capable of changing the position of the spanner portion 1 in the axial direction according to the operation of the rotating mechanism 40 . In this case, even if the position of the nut N in the axial direction changes when the nut N gripped by the spanner portion 1 is rotated by the rotating mechanism 40, the spanner portion is arranged so as to follow the change in the position of the nut N. 1 position can be changed. Therefore, even if the operation of rotating the nut N is continuously performed, the wrench portion 1 can appropriately grip the nut N.

In the fastening device described above, the moving mechanism 30 may be capable of determining the position of the spanner portion 1 with respect to the nut N according to the type of the nut N. In this case, the nut N can be gripped at an appropriate portion of the spanner portion 1 when the portion of the spanner portion 1 that contacts the nut N (the nut contact portions 1aa, 1ab, and 1ac) differs for each type of nut N.

In the fastening device described above, the grip portion 20 may include a plurality of nut contact portions 1aa, 1ab, and 1ac respectively corresponding to a plurality of types of nuts N. The moving mechanism 30 may move the spanner portion 1 so that one of the plurality of nut contact portions 1aa, 1ab, and 1ac contacts the nut N.

In this case, the nut N can be gripped by appropriate nut contact portions 1aa, 1ab, and 1ac according to the type of nut N.

In the fastening device described above, the nut N may be a hexagonal nut. The rotating mechanism 40 may be capable of rotating the grip part 20 by 60° or more around the rotating shaft 70 .

In this case, the gripping portion 20 (the nut N) can be rotated by 60° or more by the rotating mechanism 40 while the gripping portion 20 grips the nut N, which is a hexagonal nut. After that, the gripping portion 20 is rotated in the opposite direction after the gripping portion 20 does not grip the nut N, and the gripping portion 20 is rotated by 60° or more by the rotating mechanism 40 while gripping the nut N again. Let By repeating such operations, the nut N can be fixed to the work target member.

In the fastening device described above, the control section 10 may control the operation of the rotating mechanism 40 according to the rotational torque when the grip section 20 rotates about the rotating shaft 70 of the nut N. Here, the rotational torque has a correlation with the tightening torque when the nut N is fixed to the work target member. Therefore, the tightening torque of the nut N can be set to a value equal to or greater than the specified value by operating the rotation mechanism 40 until the rotational torque becomes equal to or greater than the specified value.

Embodiment 2.
<Structure of fastening device>
14 to 19 are schematic plan views for explaining the configuration of a fastening device according to Embodiment 2 and a nut fastening method using the fastening device. 14 to 19 correspond to FIGS. 7 to 12, respectively.

The fastening device shown in FIGS. 14-19 basically has the same configuration as the fastening device shown in FIGS. The shape and setting of the turning angle of the worm wheel 4e are different from the fastening device shown in FIGS. That is, in the fastening device shown in FIGS. 14 to 19, the width of the worm wheel 4e in the turning direction (circumferential direction) is wider than the width of the worm wheel 4e of the fastening device shown in FIGS. ing. Further, in the fastening device shown in FIGS. 14 to 19, the nut N to be operated is a square nut, so the turning angle of the worm wheel 4e is set to 90° or more. That is, in the rotating mechanism 40 of the fastening device, it is possible to rotate the grip portion 20 (see FIG. 1) including the wrench portion 1 by 90° or more about the rotating shaft 70 (see FIG. 1).

<fastening method>
A nut fastening method using the fastening device described above is basically the same as the nut fastening method shown in FIGS. That is, as in the nut fastening method shown in FIG. 6, in the nut fastening method according to the present embodiment, first, the step (S1) of raising and lowering the wrench portion to the height of the nut is performed.

Next, the step (S2) of inserting the spanner portion into the nut is performed. In this step (S2), as shown in FIG. 14, the spanner portion 1 is moved by the radial direction moving portion 3 so that the nut contact portion 1aa of the arm 1a of the spanner portion 1 reaches the position of the nut N. .

Next, the step (S3) of closing the arms of the spanner portion and clamping the nut is performed. In this step (S3), the shaft driving portion 2c of the driving portion 2 inserts the wedge portion 2a into the root side of the arm 1a. As a result, as shown in FIG. 15, the tip side of the arm 1a is closed.

Next, the step (S4) of rotating the spanner portion while closing the arm of the spanner portion is performed. In this step (S4), after the arm 1a is closed until it clamps the nut N, the wedge portion 2a is inserted between the arms 1a by the shaft 2b to close the tip side of the arm 1a, and the motor 4a (FIG. 1) is rotated. ) is operated to rotate the worm wheel 4e.

Next, a step (S5) of determining whether the arm is completely closed is performed. In this step (S5), the wrench portion 1 is rotated in the direction of tightening the nut N about the rotation shaft 70 (see FIG. 1) of the nut N. As shown in FIG. Then, the wedge portion 2a is inserted between the arms 1a until the movement of the wedge portion 2a stops mechanically. Specifically, when the wedge portion 2a can be moved, it is determined as NO in the step (S5), and the process returns to the step (S4). On the other hand, when the wedge portion 2a cannot be moved, the two faces of the nut N are clamped by a pair of arms 1a as shown in FIG. As a result, YES is determined in step (S5).

Next, when it is judged as YES in the step (S5), the step (S6) of tightening the nut by turning the entire wrench portion while the arm is closed is performed. In this step (S6), as shown in FIG. 17, the nut N can be tightened by rotating the wrench portion 1 further in the direction in which the nut N is tightened by the rotary drive portion 4 .

Next, a step (S7) of determining whether or not the nut N has reached a specified tightening torque is carried out. In this step (S7), it is determined whether or not the tightening torque of the nut N has reached an arbitrarily specified specified tightening torque.

If NO is determined in the step (S7), a step (S12) of determining whether the wrench portion has reached the turning limit angle is carried out. In this step (S12), it is determined whether or not the turning angle of the wrench portion 1, that is, the turning angle of the worm wheel 4e has reached a preset turning limit angle.

If the determination in step (S12) is NO, the processes after step (S6) are performed again. On the other hand, if the determination in step (S12) is YES, the step (S13) of opening the arm and releasing the nut is performed. In this step (S13), as shown in FIG. 18, the wedge portion 2a is removed from between the pair of arms 1a by the shaft driving portion 2c, thereby increasing the distance between the tip portions of the pair of arms 1a. Enlarge, that is, open the arm 1a. As a result, the nut N is released from the spanner portion 1 .

Next, a step (S14) of rotating the spanner portion in the opposite direction is performed. In this step, the motor 4a of the rotary drive unit 4 is operated to rotate the worm wheel 4e. The direction of rotation of the motor 4a in step (S14) is opposite to the direction of rotation of the motor in step (S4). Therefore, the worm wheel 4e turns in a direction opposite to the turning direction in step (S4). The turning angle in step (S14) is, for example, 90° when the nut N is a square nut. As a result, as shown in FIG. 19, the wrench portion 1 is turned counterclockwise from the position shown in FIG. 14 in step (S2). After that, the processes after the step (S3) are repeated until the judgment result in the step (S7) becomes YES.

If YES is determined in step (S7), steps (S8), (S9), (S10), and (S11) are performed in the same manner as in the fastening method shown in FIG. When the step (S11) ends, the nut fastening method using the fastening device according to the present embodiment ends.

By doing so, the same effect as the fastening method in the first embodiment can be obtained. Further, when the nut N is loosened by the fastening device, the nut N can be loosened. Further, in this case, in step (S7), it is determined whether the nut N is sufficiently loosened, not whether the specified tightening torque has been reached.

In the fastening device described above, the shape of the arm 1a and the shape of the worm wheel 4e may be determined according to the shape of the nut N to be operated. The turning angle of the worm wheel 4e may also be set according to the shape of the nut N.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. As long as there is no contradiction, at least two of the embodiments disclosed this time may be combined. The basic scope of the present disclosure is indicated by the scope of claims rather than the above description, and is intended to include all changes within the scope and meaning of equivalents of the scope of claims.

Reference Signs List 1 spanner portion 1a arm 1aa, 1ab, 1ac nut contact portion 1b center pin 1c spring 2 drive portion 2a wedge portion 2b shaft 2c shaft drive portion 2d shaft drive portion controller 3 radial movement portion , 3a radial direction movement base, 3b, 5b movement portion, 3c radial direction movement portion controller, 4 rotation drive portion, 4a motor, 4b motor fixing plate, 4c worm gear, 4d worm, 4da screw structure, 4e worm wheel, 4ea gear portion , 4f worm wheel swivel base, 4g motor controller, 4h linear projection, 4i groove, 5 axial movement unit, 5a axial movement base, 5c axial movement unit controller, 6 device base, 10 control unit, 20 gripping unit, 30 moving mechanism, 40 rotating mechanism, 70 rotating shaft, 71 arrow, 90 work target member, N nut.

Claims (8)

a gripping portion capable of gripping multiple types of nuts;
a moving mechanism capable of positioning the gripping portion with respect to the nut;
a rotation mechanism that rotates the gripping portion that grips the nut around the rotation axis of the nut;
A fastening device comprising a control section that controls the grip section, the moving mechanism, and the rotating mechanism. The gripping part is
a spanner portion that grips the nut;
a drive unit that switches between a state in which the wrench portion grips the nut and a state in which the nut is not gripped by opening and closing the wrench portion;
The moving mechanism is
a radial moving portion that moves the spanner portion in a radial direction perpendicular to the rotating shaft;
2. The fastening device according to claim 1, further comprising an axial movement portion for moving said spanner portion in an axial direction along said rotation axis. The fastening device according to claim 2, wherein the moving mechanism can change the position of the spanner portion in the axial direction according to the operation of the rotating mechanism. The fastening device according to claim 2 or 3, wherein the moving mechanism can determine the position of the spanner portion with respect to the nut according to the type of the nut. The gripping portion includes a plurality of nut contact portions corresponding to each of the plurality of types of nuts,
The fastening device according to claim 4, wherein the moving mechanism moves the spanner portion such that one of the plurality of nut contact portions contacts the nut. the nut is a hexagonal nut,
The fastening device according to any one of claims 1 to 5, wherein the rotating mechanism is capable of rotating the gripping portion by 60° or more about the rotating shaft. The nut is a square nut,
The fastening device according to any one of claims 1 to 5, wherein the rotating mechanism is capable of rotating the gripping portion by 90° or more about the rotating shaft. 8. The control unit according to any one of claims 1 to 7, wherein the control unit controls the operation of the rotating mechanism in accordance with rotational torque when the gripping unit rotates around the rotation axis of the nut. fastening device.

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