JP2008142846A - Positioning device for mounting member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for installing a fastening member to a fastening means, capable of correctly placing the fastening member to a prescribed position quickly and securely, and stably performing repeated action for a long time. <P>SOLUTION: As a bolt is positioned to an opening 111, a disc part 106 is rotated, so that a rotation shaft side pin 22 moves inside a cam groove 106a till a link cam 21 rotates around a bolt receiving member side pin 23. At this time, the link cam 21 gets in contact with a bolt inside the opening 111, thereby aligning the bolt. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for aligning an attachment member typified by a fastening member such as a screw at a predetermined position.

  In assembling various products, fastening members such as screws are used to fix various members. Also, in order to increase production speed and pursue cost reduction in the production line, fastening means (for example, bolts) that automatically perform fastening (tightening) of these fastening members using a mechanism such as a robot arm. And a mechanism for further rotating and tightening.

  In the above-described automated fastening means, (1) a fastening member is attached to the fastening means, (2) the fastening means is moved to a fastening position, and (3) the fastening member is attached (for example, screwing into a screw hole or the like). These steps are repeated. As such a technique, for example, those described in Patent Documents 1 and 2 are known.

JP-A-5-237729 JP 2001-179553 A

  By the way, in order to increase productivity, it is required that the steps (1) to (3) described above be performed in as short a time as possible. Further, it is required that the fastening member is mounted on the fastening means (1) without error. In addition, since the above-described steps (1) to (3) are repeatedly performed for a long time, it is necessary to ensure that each step is stably and reliably performed for a long time. In particular, it is necessary to ensure that the fastening member is attached to the fastening means in as short a time as possible.

  In a system in which the mounting of the fastening member to the fastening means is automated, a mechanism is required in which the fastening member is accurately placed at a predetermined position and received by the computer-controlled fastening means. At this time, it is important to perform the process of placing the fastening member accurately at a predetermined position quickly and reliably, and in a repeated operation, stably for a long time.

  Current technology is not sufficient to meet this requirement. Therefore, the present invention is a technique for mounting a fastening member on a fastening means, and can quickly and reliably perform the process of accurately placing the fastening member at a predetermined position, and can be stably performed over a long period of time in repeated operations. The purpose is to provide a technique for performing the operation.

  In the mounting member alignment apparatus of the present invention, a predetermined shaft, an opening for receiving the mounting member at the position of the predetermined shaft is formed, a receiving member rotatable around the predetermined shaft, and the predetermined shaft A rotating member capable of rotating around, a plurality of link cams disposed between the receiving member and the rotating member, and a plurality of cam grooves provided in the rotating member and corresponding to each of the plurality of link cams Each of the plurality of cam grooves, and a plurality of rotation pins that move in the grooves, and the link cam is fixed in a state of being rotatable with respect to the receiving member. Each of the plurality of rotating pins is rotated by rotating the receiving member relative to the rotating member around the predetermined axis. The move each groove, wherein said mounting member located within said opening by said plurality of link cam is sandwiched.

  According to the above configuration, when the attachment member such as a screw is positioned in the opening of the receiving member, when the receiving member and the rotating member are relatively rotated, the rotation pin slides in the cam groove, A plurality of link cams rotate simultaneously in the direction of a predetermined axis center. Accordingly, the attachment member such as a screw is pushed so as to be sandwiched by the plurality of link cams from the circumferential direction of the shaft to the axial center direction, and the shaft of the attachment member can coincide with a predetermined axis in the apparatus. Since this operation is performed using the rotation of the member as a driving force, it is reliably performed in a short time. In addition, since the process of aligning the shaft position of the mounting member is performed by a mechanical mechanism with a simple configuration, it is difficult to break down and a reliable process can be performed stably over a long period of time.

  In the present invention, it is desirable to further include a braking means for braking the rotation of the receiving member and a rotating means for rotating the rotating portion. According to this aspect, the force for rotating the link cam can be effectively generated by the braking force acting on the receiving member and the rotational force acting on the rotating member.

  In the present invention, it is desirable that the attachment member is a screw member. According to this aspect, the axial position of the screw can be easily adjusted, and the efficiency of the screw tightening process can be improved. Examples of the screw member include a bolt, a screw, and a tapping screw.

  Further, in this aspect, the number of link cams is three, and the link cams rotate and approach the screw members from three directions so that the shafts of the screw members coincide with the predetermined axes. It is desirable. According to this aspect, it is possible to obtain a simple and reliable shaft member alignment mechanism.

  Moreover, in this invention, it is desirable for the opening provided in the receiving member to have a diameter expanding structure in which the diameter increases toward the outside. According to this aspect, since the opening has a structure having a taper shape toward the outside, the mounting member is guided to a predetermined position even if the positioning accuracy of the mounting member to the opening is somewhat bad, and the opening is surely performed. An attachment member can be positioned within the interior.

  According to the present invention, in the technique of attaching the fastening member to the fastening means, the process of accurately placing the fastening member at a predetermined position can be performed quickly and reliably, and further, it is stable over a long time in repeated operations. A technique for performing the operation can be provided.

1. First embodiment (configuration of the embodiment)
FIG. 1 is a cross-sectional view showing an example of a fastening member alignment apparatus using the present invention, FIG. 2 is a perspective exploded view showing a part thereof, and FIG. 3 is a conceptual diagram for explaining the operation thereof. It is. FIG. 1 shows a bolt shaft alignment device 100 which is an example of a fastening member alignment device.

  The bolt shaft alignment apparatus 100 includes a rotation shaft 101. The rotating shaft 101 is supported by the shaft support portion 102 in a rotatable state. The shaft support portion 102 is fixed to a housing (not shown) that supports the bolt shaft alignment device 100. A pulley 103 is fixed to the lower portion of the rotating shaft 101, and the pulley 103 is driven by a drive belt 104. The drive belt 104 is driven by a drive motor (not shown).

  FIG. 2 shows an exploded structure near the upper portion of the rotating shaft 101. In FIG. 2, the description below the shaft support portion 102 shown in FIG. 1 is omitted. The upper part of the rotating shaft 101 has a disk part 106. The disc portion 106 is provided with three cam grooves 106a to 106c. The cam grooves 106a to 106c are arranged around the rotation axis and have a shape extending obliquely.

  As shown in FIG. 2, the rotating shaft side pin 22 that is a rotating pin is loosely fitted (loosely fitted) into the cam groove 106a, and the rotating shaft side pin 22 is slidable in the longitudinal direction of the cam groove 106a. . The rotary shaft side pin 22 is fitted and fixed in a pin hole 21 a provided at one end of the link cam 21. A pin hole 21b is provided at the other end of the link cam 21, and a bolt receiving member side pin 23 is fitted in a rotatable state. The bolt receiving member side pin 23 is fitted and fixed in a pin hole 109 a provided in the bolt receiving member 109.

  As shown in FIG. 2, the bolt receiving member 109 has a disk shape and includes an opening 111 for receiving a bolt (denoted by reference numeral 110 in FIG. 1) in the center. As shown in FIG. 1, the shape of the vertical cross section at the top of the opening 111 is a diameter-expanded structure (mortar-shaped structure) in which the inner diameter gradually increases upward. By setting it as such a shape, a diameter-expanded part can be functioned as a guide guide for reliably dropping the bolt falling into the opening 111 from above into the opening 111. Further, the minimum diameter inside the opening 111 is set to a value slightly larger than the maximum diameter of the shaft diameter of the bolt to be used.

  FIG. 2 shows one set of the link cam 21, the rotary shaft side pin 22 and the bolt receiving member side pin 23, but two other sets of similar configurations are prepared, each of which is on the rotary shaft side. Pins and bolt receiving member side pins are arranged. That is, the rotating shaft side pin is fixed to one end of another link cam not shown in FIG. 2, and the rotating shaft side pin is loosely fitted in the cam groove 106b. Also, one end of the bolt receiving member side pin is fixed to the other end of the link cam in a rotatable state, and the other end of the bolt receiving member side pin is fitted into the pin hole 109b and fixed. Further, a rotary shaft side pin is fixed to one end of another link cam not shown in FIG. 2, and the rotary shaft side pin is loosely fitted in the cam groove 106c. Also, one end of the bolt receiving member side pin is fixed to the other end of the link cam in a rotatable state, and the other end of the bolt receiving member side pin is fitted and fixed in the pin hole 109c.

  That is, the rotating shaft 101 and the bolt receiving member 109 are engaged with each other by three link cams (only the link cam 201 is shown in FIG. 2). The bolt receiving member 109 is fixed to the outer cylindrical member 112 with the rotating shaft 101 and the bolt receiving member 109 engaged. A disc gear 113 shown in FIG. 1 is fixed to the lower portion of the outer cylindrical member 112. When the outer cylindrical member 112 rotates, the disc gear 113 rotates. The disc gear 113 meshes with the disc gear 114, and a rotary damper 115 is connected to the rotating shaft of the disc gear 114.

  The rotary damper 115 has a structure in which high-viscosity oil is filled therein, and a blade attached to the rotary shaft moves inside the rotary damper 115. When a driving force is transmitted to the rotary damper 115, a resistance force that makes it difficult to drive the rotary shaft of the rotary damper 115 is generated due to the viscosity of the oil.

(Operation of the embodiment)
FIG. 3 is a conceptual diagram showing a cross-sectional structure taken along the plane AA ′ in FIG. 1 as viewed from above. FIG. 3 shows the operation of the bolt alignment apparatus 100 shown in FIG. 1 in stages. 3, the rotary shaft side pin 22 loosely fitted in the cam groove 106a, the link cam 21 with the rotary shaft side pin 22 fixed at one end, and the other end of the link cam 21 are rotatably fixed. The bolt receiving member side pin 23 fixed to the pin hole 109a is shown. Also, in FIG. 3, a rotary shaft side pin 32, which is a rotational pin loosely fitted in the cam groove 106 b, a link cam 31 with the rotary shaft side pin 32 fixed to one end, and the other end of the link cam 31 are rotatable. The bolt receiving member side pin 33 fixed to the pin hole 109b of FIG. 2 is shown. Also, in FIG. 3, a rotation shaft side pin 42 that is a rotation pin loosely fitted in the cam groove 106 c, a link cam 41 with the rotation shaft side pin 42 fixed to one end, and the other end of the link cam 41 are rotatable. A bolt receiving member side pin 43 is shown which is fixed and fixed to the pin hole 109c of FIG.

  Hereinafter, a bolt supply feeder, which will be described later, is arranged above the bolt axis aligning device 100 shown in FIG. 1, and the bolt 110 is dropped and received by the bolt receiving member 109, and then the bolt 110 is aligned (axial position). The step of attaching the bolt 110 to the fastening means (bolt fastening device) after the positioning is performed will be described in order.

  First, FIG. 3A shows a state after the bolt 110 (see FIG. 1) has dropped into the opening 111. Since the inner diameter of the opening 111 is slightly larger than that of the bolt 110, the axial center of the bolt 110 is not accurately aligned with the bolt axis aligning device 100 at this stage.

  When the bolt 110 falls into the opening 111, the driving force is transmitted from the driving belt 104 (see FIG. 1), and the pulley 103 is rotated counterclockwise as viewed from above. Since the bolt receiving portion 109 is integrated with the outer cylindrical member 112, and the outer cylindrical member 112 is connected to the rotary damper 115 via the disk gears 113 and 114, the bolt receiving portion 109 is rotated. Shows resistance to the force to be tried. Therefore, when the disk portion 106 is rotated counterclockwise relative to the bolt receiving portion 109 (and the outer cylindrical member 112 integrated therewith) as viewed from above, due to this resistance force, Each of the rotating shaft side pins 22, 32 and 42 moves in the cam grooves 106a to 106c.

  Incidentally, the cam grooves 106a to 106c have a shape extending obliquely toward the rotation axis, and each of the bolt receiving member side pins 23, 33 and 43 is a bolt receiving member 109 (see FIG. 1 or FIG. 3). ). Therefore, according to the movement in the cam grooves 106a-b of the rotary shaft side pins 22, 32, and 42 described above, the link cams 21, 31 and 41 have the bolt receiving member side pins 23, 33 and 43 as axes. Rotate inward so that the cam groove swings the neck. FIG. 3B shows this state.

  By the rotation of the link cams 21, 31 and 41, the link cams 21, 31 and 41 each generate a force for tightening the shaft of the bolt 110 from three directions in the direction from the periphery to the shaft center (FIG. 3C )reference). By the force acting from these three link cams, the position of the bolt 110 is adjusted so as to coincide with the rotation axis of the disc portion 106 (the axis center of the rotation axis 101). That is, by rotating the rotating shaft 101 of FIG. 1, it is possible to align the bolt 110 held with the play in the opening 111 with the bolt aligning device 100.

  When this axial alignment is completed, the position of the bolt 110 where the axial alignment has been performed on the bolt fastening means (means for turning the bolt and fastening using a predetermined screw hole) that moves by multi-joint drive or the like not shown. The bolt head is brought into contact with the bolt holding portion. At this time, the axis of the bolt 110 and the axis of the bolt fastening means (not shown) can be accurately aligned. In this state, when the bolt fastening means (not shown) is slightly pushed in the direction of the bolt 110 and the bolt is rotated slightly, the bolt holding part (for example, hexagonal concave) on the bolt fastening means side and the head of the bolt (for example, hexagonal shape) At the stage when the phase with the portion is matched, the two are coupled (that is, the bolt is attached to the bolt holding portion).

  Thereafter, as shown in FIG. 3D, the rotating shaft 101 (see FIG. 1) is rotated clockwise. Then, the force acting on the bolt from the link cams 21, 31 and 41 is loosened by the reverse action of the case of FIG. Also in this case, the reaction force acting in the counterclockwise direction of the outer cylindrical member 112 due to the clockwise rotation of the disk portion 106 integrated with the rotating shaft 101 due to the resistance force of the rotary damper 115 (in the clockwise direction). A force against the force to rotate) is generated, and the link cams 21, 31 and 41 move in the reverse direction to the case of FIG. That is, the end portions of the link cams 21, 31 and 41 on the cam groove 106 a-c side rotate so as to be separated from the bolt 110. And when this rotation is complete | finished, it returns to the state shown to FIG. 3 (A).

  The bolt 110 can be pulled away from the bolt axis aligning device 100 by pulling up the bolt fastening means (not shown). Thereafter, returning to the state shown in FIG. 3A, the next bolt shaft alignment operation can be performed. By repeating the above operation, the axial position of the bolt can be adjusted, and then the bolt can be held by the fastening means.

(Advantages of the embodiment)
According to the configuration described above, the bolt can be accurately positioned at a preset position, so that the bolt can be reliably held by the computer-controlled fastening means. Moreover, since the accuracy of axis alignment is determined by the dimensional accuracy and assembly accuracy of the members related to the link cam, high accuracy can be ensured. In addition, since the mechanical alignment is performed by the movement of the link cam, it is difficult for a defect to occur in a long-time repetitive operation, and since the number of parts is simple and the structure is simple, an apparatus can be obtained at low cost. In addition, since the accuracy of the position where the bolt 110 is dropped into the opening 111 has a certain range, complicated control is not required, and the equipment cost of the production line can be suppressed in that respect.

  In particular, the structure in which three link cams are arranged can effectively obtain a pivoting action with a simple configuration. Further, since the inner diameter of the flange portion of the opening 111 can be made slightly larger than the shaft diameter of the bolt 110, a plurality of types of shaft diameters of the bolt 110 can be used. For example, in a continuous bolt tightening process, it is assumed that a certain part is a 5 mm diameter bolt and the other part is a 6 mm diameter bolt. In this case, the opening 111 corresponds to a bolt with a diameter of 6 mm, and the shape and size of a portion that expands in a mortar shape can hold a bolt with a diameter of 5 mm. Then, even if the bolt supplied to the bolt fastening means has a diameter of 5 mm or 6 mm, the axis alignment function shown in FIGS. 3 (A) to 3 (D) works and rotates regardless of the axis diameter. The axis of the bolt 110 can be aligned with the axis of the axis 101 (see FIG. 1). That is, versatility corresponding to different shaft diameters can be obtained without requiring a complicated control mechanism.

(Modification of embodiment)
In the example described above, the example in which the bolt 110 is dropped into the opening 111, the bolt 110 is held there, and then the axis is aligned is described. However, the bolt 110 is held in the opening 111 by the robot mechanism. You can also. Although an example in which a bolt is used as the fastening member has been described here, other screw members such as screws and tapping screws, or rivets can be used as the fastening member. Further, the number of link cams may be two or four or more.

2. Second Embodiment (Configuration of Embodiment)
An example when the bolt alignment apparatus 100 shown in FIG. 1 is applied to a machine tool used on a production line will be described. FIG. 4 is a conceptual diagram showing an example of a machine tool using the present invention. FIG. 4 shows a conceptual view of a machine tool having a function of tightening a bolt to a product being assembled using a robot arm having a multi-joint mechanism as viewed from above.

  The machine tool shown in FIG. The fixed base 401 is fixed to the floor surface on which the machine tool shown in FIG. 4 is installed. A bolt supply mechanism 402 </ b> A is disposed on the fixed base 401. The bolt supply mechanism 402A includes a parts feeder 402, a bolt supply line 403, and a bolt slide mechanism 405. A large number of bolts 404 are accommodated in the parts feeder 402, and the bolts 404 are supplied to the preset unit 406 via the bolt supply line 403 and the bolt slide mechanism 405. That is, the bolt supply line 403 sequentially sends the bolts 404 sent from the parts feeder 402 to the bolt slide mechanism 405. The bolt slide mechanism 405 slides the bolts one by one with a slide mechanism (not shown), and finally drops them to the preset unit 406 positioned below at a predetermined timing.

  The preset unit 406 has a rotatable disk shape and is installed on the movable base 407. The preset unit 406 includes six bolt holding means 408. The bolt holding means 408 has a funnel shape, receives a bolt that has dropped from the end of the bolt slide mechanism 405, temporarily holds it, and releases this holding state and further drops the bolt downward. It has.

  The movable pedestal 407 is movable in the vertical direction in the figure by the moving mechanism 430 with respect to the fixed base 401. That is, the moving mechanism 430 includes a cylinder 432 and a piston 434. The piston 434 is driven by hydraulic pressure and moves in the vertical direction in the figure with respect to the cylinder 432.

  FIG. 5 is a side view showing an outline of the moving mechanism 430. FIG. 5 shows an outline of the moving mechanism 430 in the state shown in FIG. As shown in FIG. 5, in the cylinder 432, a fixing portion 433 at the end of the main body is fixed to the bracket 431 by a pin 431a. The bracket 431 is fixed to a fixing member 436 fixed to the fixing base 401, and includes a hole for allowing the pin 431a to pass therethrough. The tip of the piston 434 is fixed to the support members 409a and 409b via the fixing members 435a and b. The support members 409a and 409b constitute a U-shaped frame structure, and the tip portion (near the upper end portion in the figure) supports the lower portion of the movable base 407. The support members 409a and 409b are supported by the fixed base side support members 415a and 415b so as to be movable in the vertical direction in the figure. This support structure is realized by a ball slide mechanism. With these structures, the movable pedestal 407 is movable with respect to the fixed base 401 in the vertical direction in the figure.

  As shown in FIG. 5, a rail 437 is fixed to the lower portion of the support member 409a. The rail 437 is supported by the fixed base side support member 415a by a ball slide mechanism so as to be slidable along the extending direction. A fixing member 435a is fixed to the tip of the piston 434, and a fixing member 435b is fixed to the fixing member 435a. The fixing member 435b is fixed inside the support members 409a and 409b.

  In the configuration shown in FIGS. 4 and 5, when the piston 434 enters and exits the cylinder 432, the movable base 407 moves in the vertical direction of FIG. 4 with respect to the fixed base 401. As an example, FIG. 4A shows a state where the piston 434 is accommodated in the cylinder 432 and the movable base 407 is positioned on the fixed base 401. 4B, the piston 434 extends upward from the state shown in FIG. 4A with respect to the cylinder 432, and accordingly, the movable base 407 is connected to the phase shifting unit 421 described later. The state moved to the overlapping position is shown.

  A bolt supply mechanism 410 </ b> A is disposed on the fixed base 401. The bolt supply mechanism 410A includes a parts feeder 410, a bolt supply line 411, and a bolt slide mechanism 412. A preset unit 413 is disposed on the movable base 407, and six bolt holding means 414 are disposed on the preset unit 413. Since these are the same configurations as the above-described bolt supply mechanism 402A and preset unit 406, description thereof will be omitted.

  The movable base 407 can be rotated 180 degrees around the shaft 407a. According to this mechanism, for example, when a bolt with a diameter of 6 mm is supplied from the bolt supply mechanism 402A and a bolt with a diameter of 5 mm is supplied from the bolt supply mechanism 410A, the movable pedestal 407 is appropriately rotated 180 around the axis 407a. The bolts having different diameters can be mixed and held in each preset unit by rotating the angle and supplying the bolts to the preset units 406 and 413.

  The machine tool shown in FIG. 4 includes a robot carriage 420. The robot carriage 420 is integrated with the phase matching unit 421 and is movable on the rails 422a and 422b. Robots 423 and 424 are arranged on the robot carriage 420. Details of the robots 423 and 424 will be described later.

  The positional relationship between the phase matching unit 421 is set so that the phase matching unit 421 is positioned below the movable base 407. In the phase alignment unit 421, six bolt alignment devices 425 and six bolt removal devices 426 having the structure shown in FIG. 1 are arranged. The bolt alignment device 425 has the structure shown in FIGS. 1 and 2 and performs the basic operation shown in FIG.

  The bolt removing device 426 can remove the bolt held by the holder for tightening the bolt, which will be described later, by hooking the thread portion of the bolt into the gap between the two hinge-shaped plate members. The bolt removing device 426 is used for removing, for example, when there is a defect in fastening of the bolt and the bolt remains in the holder for fastening the bolt.

  The phase matching unit 421 is provided with six bolt alignment devices 427 and six bolt removal devices 428. The bolt shaft aligning device 427 is the same as the bolt shaft aligning device 425, and the bolt removing device 428 is the same as the bolt removing device 426.

  Details of the robots 423 and 424 will be described below. FIG. 6 is a perspective view showing an outline of the bolt fastening device 1 attached to the tips (hand end portions) of the robots 423 and 424. FIG. 7 is a side view showing an outline of a part of the configuration shown in FIG. The bolt fastening apparatus 1 shown in FIG. 6 includes a multi-joint mechanism 10, a socket switching mechanism 200, a feed mechanism 300, and a tightening nut runner 500. The multi-joint mechanism 10 includes a plurality of joint mechanisms other than those shown in the figure, but these are not shown in FIG.

  The multi-joint mechanism 10 includes a robot arm unit 11, and a mounting bracket 12 is attached to the tip thereof. The multi-joint mechanism 10 includes a plurality of rod-like members (not shown) and a plurality of joints, and can guide the bolt fastening device 1 to a target position. A socket switching mechanism 200 and a feed mechanism 300 are attached to the mounting bracket 12.

  The socket switching mechanism 200 is attached to the distal end portion of the robot arm unit 11 via the mounting bracket 12 and includes a socket switching motor 210 and a socket folder 220. The socket switching motor 210 is fixed to the mounting bracket 12, and the socket folder 220 is connected to the rotating shaft thereof. The socket folder 220 is formed in a substantially cylindrical body, and can be rotated in the arrow A direction or the arrow B direction by the socket switching motor 210.

  On the same circumference outside the cylindrical body of the socket folder 220, six clamping sockets 230 and one sensing unit 240 are attached at equal intervals. The tightening socket 230 includes a socket shaft 232 having a socket 231 attached to the tip. The socket shaft 232 is held by the tightening socket 230 so as to be movable in the axial direction and rotatable about the axis. The fastening socket 230 has a base portion 230 a fixed to the socket folder 220.

  The socket shaft 232 is biased forward by a spring member, and when the socket 231 is pressed against an appropriate member, the socket 231 is retracted elastically, and at the same time, a force pressing the member elastically is applied. . That is, as shown in FIG. 7, the socket shaft 232 is elastically supported by the base portion 230 a of the clamping socket 230 by the floating mechanism 233. The floating mechanism 233 includes a spring 233a, and presses the socket 231 forward and absorbs an overload on the screw S caused by being pushed by the feed mechanism 300. A rotating shaft 237 is coaxially arranged with respect to the socket shaft 232. The rotating shaft 237 is configured to transmit a rotational force to the socket shaft 232 by an engagement structure (not shown) and to move in the axial direction with respect to the socket shaft 232. The rotating shaft 237 is fixed to the socket folder 220 so as to be axially movable and rotatable by a socket feed mechanism 234 having a ball spline 234a. Further, the socket 231 has a hexagonal recess corresponding to the hexagonal portion of the bolt S head, and is magnetic. The bolt S is held (attached) to the socket 231 by attracting the head (hexagonal part) of the bolt S containing an iron component by magnetism to the hexagonal recess.

  As shown in FIG. 7, the fastening socket 230 includes a socket return mechanism 235. The socket return mechanism 235 includes a spring 235a, and after tightening the screw S, when the tightening nut runner 500 is retracted by the action of the feed mechanism 300, the socket 231 is retracted accordingly. In FIG. 6, the spring 235a is omitted. A joint portion 236 is disposed at the rear end of the rotation shaft 237. The joint portion 236 is divided into four tips, and the divided tips are formed into a substantially convex shape having a tapered shape.

  Returning to FIG. 6, the sensing unit 240 is a CCD camera, and the attached position of the bolt S is optically detected by image analysis of the captured image by an image analysis device (not shown). The feed mechanism 300 is fixed to the mounting bracket 12 and moves the tightening nut runner 500 attached to the feed mechanism 300 forward (leftward in FIG. 1) or backward (rightward in FIG. 1). With this mechanism, the feed mechanism 300 can push the socket 231 forward via the tightening nut runner 500.

  As shown in FIG. 7, the feed mechanism 300 includes a pair of feed cylinders 310 and a pair of slide guides 320. In one of the pair of feed cylinders 310, the right side portion of the feed cylinder 310 is fixed to the side surface of the mounting bracket 12 on the right side of the tightening nut runner 500 when viewed from the front of the screw tightening device 1 (left direction in FIG. 1). The other of the pair of feed cylinders 310 has the left side of the feed cylinder 310 fixed to the side of the mounting bracket 12 on the left side of the tightening nut runner 500 when viewed from the front of the screw tightening device 1 (left direction in FIG. 1). Yes. That is, the feed cylinders 310 are fixed to the opposing side surfaces of the pair of mounting brackets 12, respectively.

  Each of the pair of feed cylinders 310 includes a piston 311 and can move the piston 311 back and forth. When the piston 311 moves back and forth, the tightening nut runner 500 provided in the feed mechanism 300 moves back and forth.

  The pair of slide guides 320 are fixed to the same positions as the pair of feed cylinders 310, that is, the side surfaces of the pair of mounting brackets 12 that face each other. Each of the slide guides 320 includes a slide column 321 and an opening 322 (see FIG. 6). Then, the slide column 321 is inserted into the opening 322 of the slide guide 320 and slides back and forth, thereby assisting the operation of the tightening nut runner 500 provided in the feed mechanism 300 to move back and forth.

  The tightening nut runner 500 is attached to the feed mechanism 300 and includes a rotating portion 510. The distal end of the rotating portion 510 is divided into four in the same manner as the joint portion 236, and the separated distal end is formed into a substantially convex shape having a tapered shape. The shapes of the joint portion 236 and the tip of the rotating portion 510 are such that when they are opposed to each other and pressed against each other, the two mesh together.

  FIG. 7 shows a socket switching motor 210. The socket switching motor 210 has a lower surface of the socket switching motor 210 fixed to the feed cylinder 310. That is, the socket switching motor 210 is fixed to the mounting bracket 12 via the feed cylinder 310. The socket switching motor 210 includes a servo motor 211 and a speed reducer 212. The output shaft 212 a of the speed reducer 212 is connected to the rotation center portion of the socket folder 220. The servo motor 211 generates power according to a control signal of a servo mechanism (not shown), and rotates the socket folder 220 clockwise or counterclockwise via the speed reducer 211.

  In the state shown in FIG. 6, the optical axis of the sensing unit 240 and the rotation axis of the rotating unit 510 coincide with each other. When the socket folder 220 rotates from the state shown in FIG. 6 and the socket shaft 232 of the arbitrary socket folder 230 and the rotation shaft of the rotation unit 510 are aligned, the rotation unit 510 is moved forward by the action of the feed mechanism 300. The tip of the rotating part 510 is coupled to the joint part 236 of the fastening socket 230. In this state, when the rotating unit 510 is rotated, the bolt S is rotated. The tightening nut runner 500 is configured to stop the rotation of the rotating portion 510 when the tightening torque becomes a predetermined value or more when the bolt S is tightened, and the tightening torque does not exceed the predetermined value. When a certain time has elapsed, the tightening operation of the bolt S is set to end.

(Operation of the embodiment)
Hereinafter, an example of the operation of the machine tool shown in FIG. 4 will be described. FIG. 4 shows an example of a state in which a product (for example, an automobile) moves on the production line (not shown) from the right to the left in the drawing, and the robots 423 and 424 attach bolts to the product in the process. Has been. In this example, since each of the robots 423 and 424 can attach 6 bolts, a total of 12 bolts can be attached to the product.

  Here, FIG. 4A shows a state immediately before the bolts are attached to the products not shown and the robots 423 and 424 return to the right on the rails 422a and 422b. In the process leading to this stage (that is, while the bolt is attached in the previous stage), the bolt is supplied from the parts feeder 402 to the bolt holding means 408 via the bolt supply line 404 and the bolt slide mechanism 405. . At this time, the preset unit 406 rotates intermittently in accordance with the supply timing of the bolts from the bolt slide mechanism 405, and the bolts are sequentially held by the six bolt holding means 408. This operation is also performed simultaneously on the preset unit 413 side.

  When all the bolt holding means 408 and 414 hold the bolt, the movable base 407 is moved upward in the drawing. At that timing, the robot carriage and the phase matching unit 421 are moved to the position shown in FIG. Then, the relative positions of the movable base 407 and the phase alignment unit 421 are adjusted, and the positions of the bolt holding means 408 and the bolt axis alignment device 425 and the positions of the bolt holding means 414 and the bolt axis alignment device 427 are adjusted. FIG. 4B shows this state.

  Next, the mechanism for holding the bolts of the bolt holding means 408 and the bolt holding means 414 is released, and the bolts are dropped down. As a result, each of the six bolts held in the preset unit 406 and the preset unit 413 falls toward the six bolt axis aligning devices 425 and the six bolt axis aligning devices 427 located therebelow. Thereafter, the bolt shaft alignment adjustment in the bolt shaft alignment devices 425 and 427 is performed by the mechanism described with reference to FIG. That is, the axial position of each bolt is adjusted by rotating the disk portion 106 (see FIG. 1 or FIG. 3) in each axis alignment device in the state shown in FIG. At this time, the operation of aligning the shaft positions of the total twelve bolts is performed simultaneously.

  When the operation of aligning the axial positions of the bolts with respect to the bolt alignment devices 425 and 427 is completed, the bolt tightening device 1 (see FIG. 6) attached to the tip portions of the robots 423 and 424 is brought close to the phase alignment unit 421 and further By performing the position adjustment that has been set, the socket 231 at the tip of each tightening socket 230 shown in FIG. 6 is brought close to each of the bolt alignment devices 425 and 427. At this time, since the position of the axis of each bolt in the phase alignment unit 421 is accurately determined, the robots 423 and 424 that are fixed relative to the phase alignment unit 421 correctly connect the socket 231 to the bolt. It can be adjusted to the position of the head.

  Then, in a state in which the rotating state of the disc portion 106 (see FIG. 1 or FIG. 3) shown in FIG. 3C is continued, the socket 231 shown in FIG. 6 is connected to the bolts on the bolt alignment devices 425 and 427. Lightly touch the head. Then, the phase of the hexagonal portion of the head of the bolt and the hexagonal concave portion of the socket 231 matches at an appropriate rotational angle position. Since the socket 231 elastically pushes the bolt, the bolt is fitted into the socket 231 at this stage, and the head of the bolt is held in the socket 231. Since the socket 231 is magnetized, the bolt is attracted to the socket 231 by the magnetic force, and the held state is maintained. The holding of the bolt in the socket 231 is performed simultaneously for all 12 bolts.

  Next, by the mechanism shown in FIG. 3D, the bolt holding function of the bolt shaft aligning devices 425 and 427 is released, and the bolt fastening device 1 shown in FIG. Then, bolts are tightened on a product (not shown) by the bolt tightening device 1 using the two robots 423 and 424.

  Hereinafter, an example of the bolt tightening procedure by the bolt tightening device 1 shown in FIG. 6 will be described. Here, an example in which six bolts are sequentially assembled will be described. First, the steps described above are performed, and the bolts S are held in all the sockets 231 of the bolt fastening device 1. Next, the multi-joint mechanism 10 is moved, and the bolt fastening device 1 is moved to the initial bolt fastening position. Then, an image is taken by the sensing unit 240 in a state where the optical axis of the sensing unit 240 is aligned with the axis of the tightening nut runner 500 (on the axis of the rotating unit 510) (state of FIG. 6). Then, by analyzing the captured image, accurate coordinates of the position of the bolt hole (hole to which the bolt is attached) are acquired, and fine adjustment is performed so that the bolt hole comes on the axis of the tightening nut runner 500. This fine adjustment is performed by moving the multi-joint mechanism 10.

  Next, the socket folder 220 is rotated, and the first tightening socket 230 is positioned on the axis of the tightening nut runner 500. That is, the socket folder is rotated to a position where the axis of the first socket 230 coincides with the axis of the tightening nut runner 500 (the axis of the rotating portion 510). Next, the rotating portion 510 is advanced by the action of the feed mechanism 300, the rotating portion 510 is coupled to the joint portion 236, and the socket 231 is further advanced into the bolt hole. Then, the rotating unit 510 is rotated, the bolt S is screwed into the bolt hole, and the bolt S is attached. When the predetermined torque is detected, the rotating unit 510 is stopped and the rotating unit 510 is moved backward. Then, the socket 231 moves backward by the action of the socket return mechanism 235 shown in FIG. At this time, the bolt S held by the magnetic force is detached from the socket 231.

  Thus, the first bolt is tightened. Next, the multi-joint mechanism 10 is moved again, and the bolt fastening apparatus 1 is moved to the next bolt fastening position. Then, the socket folder 220 is rotated, the optical axis of the sensing unit 240 is aligned with the axis of the tightening nut runner 500 (on the axis of the rotating unit 510), and sensing is performed again. Thereafter, the same operation is repeated, and the second and subsequent bolts S are sequentially tightened. In the apparatus shown in FIG. 4, since there are two robots, the two robots move simultaneously, and two bolts are tightened. In the bolt tightening process, the workpiece (product being assembled) is moved from the right to the left in the drawing, and the robot carriage 420 is also moved from the right to the left in the drawing in accordance with the movement. . Thus, returning to the state shown in FIG. 4A, the same process as described above is performed again, whereby the bolt is assembled to the next workpiece.

  In the above-described bolt tightening, if a specified torque cannot be detected, it is determined that the tightening is defective. In this case, the multi-joint mechanism 10 is moved after the tightening operation in all the six sockets 231 (see FIG. 6) is completed, and the bolt tightening device 1 is moved to the phase matching unit 421. Then, the position of each socket 231 is adjusted to the position of the bolt removing device 426 (or 428), and the tip of each socket 231 is brought close to the bolt removing device 426 (or 428). If a bolt remains in the socket 231, the thread portion of the residual bolt is caught on the bolt removing device 426 (or 428), and the bolt is removed from the socket 231. Thereafter, the process returns to the state shown in FIG. 4A, and the work for the next workpiece is performed.

  Here, an example is shown in which six bolts are attached by one robot, but the number of bolts to be attached may be 5 or less. Moreover, what has a different diameter may be included in the plurality of bolts. Further, although the case where two robots move simultaneously has been described, the number of robots may be one, or may be three or more. In the above example, the configuration in which the disc portion 106 is rotated and the bolt receiving member 109 side is braked has been described. However, the disc portion 106 may be braked and the bolt receiving member 109 side may be rotated. Further, the means for generating the reaction force (braking force) against the rotation is not limited to the oil damper 115, but is a simple weight, a servo motor for generating the rotational force in the reverse direction, an appropriate friction means, a biasing means such as a spring, etc. Etc. Moreover, although the example of the fastening member (bolt in this example) was demonstrated as a member to attach, various components (for example, electronic components etc.) other than a fastening member can also be utilized. In addition, although a multi-joint mechanism is exemplified as the robot, the present invention can also be applied to a configuration in which a bolt fastening device (fastening means) moves on an XY plane and fastens a bolt.

  INDUSTRIAL APPLICABILITY The present invention can be used for a mechanism that supplies a fastening member to a fastening means for fastening fastening members such as bolts and screws.

It is sectional drawing which shows the outline | summary of the axial alignment apparatus of the volt | bolt using invention. It is a perspective exploded view showing an outline of a part of a bolt alignment device using the invention. It is a conceptual diagram which shows the operation state of the axis alignment apparatus of a volt | bolt using invention. It is a conceptual diagram which shows an example of the machine tool using invention. It is a side view which shows a part of structure shown in FIG. It is a perspective view which shows the outline | summary of the bolt fastening apparatus in the machine tool shown in FIG. It is a side view which shows a part of mechanism of the bolt fastening apparatus shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... Bolt axis alignment apparatus, 101 ... Rotating shaft, 102 ... Shaft support part, 103 ... Pulley, 106 ... Disc part, 106a-106c ... Cam groove, 109a-109c ... Pin hole, 109 ... Bolt receiving member, 110 ... Bolt, 111 ... opening, 112 ... outer cylindrical member, 113 ... disc gear, 114 ... disc gear, 115 ... rotary damper, 21 ... link cam, 21a ... pin hole, 21b ... pin hole, 22 ... rotating shaft side pin (Rotating pin), 23 ... bolt receiving member side pin, 31 ... link cam, 32 ... rotating shaft side pin (rotating pin), 33 ... bolt receiving member side pin, 41 ... link cam, 42 ... rotating shaft side pin (Rotating pin), 43... Bolt receiving member side pin.

Claims (5)

A given axis,
An opening for receiving the attachment member is formed at the position of the predetermined axis, and the receiving member is rotatable around the predetermined axis;
A rotating member rotatable around the predetermined axis;
A plurality of link cams disposed between the receiving member and the rotating member;
A plurality of cam grooves provided in the rotating member and corresponding to each of the plurality of link cams;
A plurality of pivot pins fixed to each of the link cams and moving in the grooves in each of the plurality of cam grooves;
A receiving member-side pin that fixes the link cam in a rotatable state with respect to the receiving member;
With
By rotating the receiving member relative to the rotating member around the predetermined axis, each of the plurality of rotating pins moves within each of the plurality of cam grooves, The mounting member positioning apparatus, wherein the mounting member positioned in the opening is sandwiched between the plurality of link cams. Braking means for braking rotation of the receiving member;
The mounting member positioning apparatus according to claim 1, further comprising: a rotating unit that rotates the rotating member.   The mounting member positioning apparatus according to claim 1, wherein the mounting member is a screw member. The number of the plurality of link cams is three,
The attachment member according to claim 3, wherein the three link cams rotate and approach the screw member from three directions so that the axis of the screw member coincides with the predetermined axis. Alignment device.   The said opening has an enlarged diameter structure in which a diameter expands toward an outer side, The positioning apparatus of the attachment member in any one of Claims 1-4 characterized by the above-mentioned.

Images