Insert insertion device

Abstract

To propose an insert insertion device which can accurately insert an insert without causing damage to a workpiece.SOLUTION: An insert insertion device 1 includes: a floating part 3 including a movable part 16 having a male screw part 11, and a fixing part 12 which is held by a robot 4 and supports the movable part 16 movably in a vertical direction; reaching sensors 14, 17 which detect a state that a distance between the movable part 16 and the fixing part 12 reaches a predetermined value to output a signal; and a control unit 25 connected to a rotary driver motor 10a and the reaching sensor 17. The control unit 25 reverses a rotation direction of the rotary driver motor 10a if the state that the distance between the movable part 16 and the fixing part 12 reaches the predetermined value is detected by the signal from the reaching sensor 17 when the rotation driver motor 10a is rotated to cause an insert i to threadedly engage with a female screw part T.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an insert insertion device for inserting an insert into a female screw portion of a workpiece.

Background Art

[0002] When fastening a member with a screw to a base material having relatively low strength such as light metal or resin, by pre-attaching an insert to the female screw portion of the base material, the load on the base material during screw fastening can be reduced, preventing damage to the base material and increasing the fastening force. For example, in Patent Document 1, a steel wire having a diamond-shaped cross section is formed into a shape of a cylindrical compression coil spring, an insert provided with a male screw-shaped portion on the outer peripheral portion of the coil and a female screw-shaped portion on the inner peripheral portion, and an insert insertion tool for inserting this insert into a base material (workpiece) are shown.

[0003] In the step of inserting the insert into the workpiece, first, the driver bit (male screw portion) located at the tip of the insertion tool and the female screw-shaped portion in the inner peripheral portion of the insert are screwed together so that the driver bit and the insert are engaged. Then, in that state, the insertion tool is moved to the workpiece, and while inserting the insert into the female screw portion provided in the workpiece, the male screw portion of the insertion tool is rotated, so that the male screw-shaped portion in the outer peripheral portion of the insert is screwed into the female screw portion of the workpiece. After that, the driver bit is rotated in the reverse direction to pull out only the insertion tool from the insert, and thus the insertion of the insert into the workpiece is completed.

[0004] Thus, in the insert insertion process, first, an operator or a working robot approaches and contacts the insert while rotating the driver bit of the insertion tool to screw the two together. On the other hand, since the insert has the properties of both a screw and a spring, there is a risk of deformation if an excessive force is applied.

[0005] In response to such problems, a device has been proposed that includes a floating portion that removes the pressing force so that the insert does not deform due to the pressing force generated by the contact between the insert and the driver bit (see, for example, Patent Document 2). The device disclosed in Patent Document 2 includes, in addition to such a floating portion, a mechanism that suppresses vibrations generated in the floating portion when the insertion tool moves greatly.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] By the way, in the insert insertion process, it is necessary to reliably insert a predetermined amount of the insert into the female screw portion of the workpiece, and various techniques have been proposed for this purpose. For example, the device shown in Patent Document 1 is configured such that a stopper (bearing 50) provided on the driver bit contacts the workpiece in the insert insertion process so that a predetermined amount of the insert is inserted into the female screw portion. However, when using this mechanism, there is a risk of damaging the workpiece when the stopper contacts the workpiece.

[0008] On the one hand, as shown in FIG. 5 of Patent Document 2, the apparatus of Patent Document 2 inserts an insert into a workpiece by driving a robot by a predetermined amount based on teaching data (including a working position). That is, since this apparatus does not use a stopper as in Patent Document 1, damage to the workpiece can be prevented. However, when inserting the insert into the female screw portion of the workpiece, the position of the screw start portion in the female screw portion of the workpiece (the screw groove start position where the male screw portion opens on the workpiece surface) and the position of the screw start portion in the male screw-shaped portion of the insert (the thread start position at the tip of the insert facing the workpiece) are not necessarily always in the same place. Further, even when the positions of the screw start portions in the female screw portion of the workpiece and in the male screw-shaped portion of the insert are aligned, for example, depending on the machining accuracy of the female screw portion or the insert, the insert and the female screw portion may start to engage after the driver bit has rotated several times. That is, there is a possibility that the insert may not be inserted into the female screw portion as set even if the robot is driven according to the teaching data.

[0009] In view of such problems, an object of the present invention is to provide an insert insertion apparatus capable of accurately inserting an insert without damaging the workpiece.

Means for Solving the Problems

[0010] The present invention relates to an insert insertion device including an insert insertion tool having a male screw portion that screws into a coiled insert and a rotary driver motor that rotates the male screw portion, a robot that lowers the insert insertion tool with respect to a female screw portion provided on a workpiece, and a floating portion having a movable portion having the insert insertion tool and a fixed portion held by the robot and supporting the movable portion so as to be movable in the vertical direction. The insert insertion device includes an arrival sensor that detects that the distance between the movable portion and the fixed portion has reached a predetermined value and outputs a signal, and a control unit connected to the rotary driver motor and the arrival sensor. When the control unit rotates the rotary driver motor to screw the insert into the female screw portion and it is detected from the signal of the arrival sensor that the distance between the movable portion and the fixed portion has reached a predetermined value, the control unit reverses the rotation direction of the rotary driver motor.

[0011] In such an insert supply device, when the control unit rotates the rotary driver motor and it is detected from the signal of the arrival sensor that the distance between the movable portion and the fixed portion has reached a predetermined value, it is preferable to drive the robot to raise the insert insertion tool.

[0012] Also, in such an insert supply device, when screwing the insert into the female screw portion, it is preferable to drive the robot so that the insert insertion tool descends at a speed faster than the insert drawing speed calculated from the rotation speed of the male screw portion and the screw pitch of the insert.

[0013] And when screwing the insert into the female screw portion, it is preferable for the control unit to drive the robot so that the insert insertion tool descends before rotating the rotary driver motor.

[0014] Furthermore, it further includes a torque sensor connected to the control unit and outputting a signal for detecting the torque of the rotary driver motor. When the torque value of the rotary driver motor is within a predetermined range according to the signal from the torque sensor and it is detected by the signal from the arrival sensor that the distance between the movable part and the fixed part has reached a predetermined value, it is preferable to reverse the rotation direction of the rotary driver motor.

Advantages of the Invention

[0015] According to the insert supply device of the present invention, deformation of the insert can be suppressed by the floating part and damage to the workpiece can be prevented. In addition, regarding the movable part and the fixed part constituting the floating part of the insert supply device of the present invention, since it is provided with an arrival sensor that detects that the distance between the movable part having a male screw part and the fixed part held by the robot has reached a predetermined value and outputs a signal, when inserting the insert screwed into the male screw part of the movable part into the female screw part of the workpiece, the arrival sensor can detect that a predetermined amount of the insert has been inserted into the female screw part. Furthermore, when it is detected by the signal from the arrival sensor that the distance between the movable part and the fixed part has reached a predetermined value, the rotation direction of the rotary driver motor is configured to be reversed, and since the male screw part can be reversed when a predetermined amount of the insert has been inserted into the female screw part of the workpiece, the insert can be accurately inserted to a predetermined position with respect to the female screw part of the workpiece.

[0016] In addition, since the detection by the arrival sensor for reversing the rotation direction of the rotary driver motor is performed when the rotary driver motor is rotated, even if the movable part moves due to the vibration of the robot when the robot is driven while the rotary driver motor is stopped, the rotary driver motor will not operate unintentionally due to a false signal from the arrival sensor.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0018] Hereinafter, an insert insertion device 1 which is an embodiment of the insert insertion device according to the present invention will be described with reference to the drawings. In the following description, for convenience, the directions of right, left, front, rear, up, down, and X, Y, Z shown in the drawings will be used for the description.

[0019] As shown in FIG. 1, the insert insertion device 1 of the present embodiment includes an insert insertion tool 2, a floating portion 3 to which the insert insertion tool 2 is attached, a robot 4 to which the floating portion 3 is attached and which three-dimensionally moves the insert insertion tool 2 with respect to a work W, and an insert supply pallet 5 that supplies an insert i (see FIG. 5) to the insert insertion tool 2. The work W of the present embodiment includes a female screw portion T as shown in FIG. 6(a).

[0020] As shown in FIG. 2, the insert insertion tool 2 includes a rotary driver unit 10 incorporating a rotary driver motor 10a (see FIG. 3), and a driver bit (male screw portion) 11 that rotates by the rotary driver motor 10a. As shown in FIG. 5(a), the driver bit 11 has a male screw shape that conforms to a female screw-shaped portion provided inside the insert i. Further, at the tip of the driver bit 11, a hook 11a that engages with a concave notch N provided inside the insert i is provided. The hook 11a is movable toward the inner and outer sides in the radial direction with respect to the driver bit 11, and is biased toward the outer side in the radial direction.

[0021] The floating portion 3 includes a base 12 that is attached to the Z unit 23 of the robot 4, which will be described later. The base 12 of the present embodiment is plate-shaped, and a circular through-hole 12a is provided at the center in the left-right direction thereof, as shown in the drawing. Further, the base 12 has circular holes on both the left and right sides with the through-hole 12a interposed therebetween, and a columnar slide shaft 13 is attached to these holes in a state of being directed in the vertical direction. In the present embodiment, the slide shaft 13 is held by the base 12 with a set screw S1. And a shielding plate 14 is provided on the right side surface of the base 12. The shielding plate 14 of the present embodiment includes a portion attached to the right side surface of the base 12 and a plate-shaped portion extending upward from this portion.

[0022] The floating portion 3 also includes coiled compression springs 15 that are respectively inserted into the two slide shafts 13.

[0023] Furthermore, the floating portion 3 has two holes through which the two slide shafts 13 are respectively inserted, and includes a movable plate 16 that is movable in the vertical direction with respect to the slide shafts 13. As shown in the drawing, the movable plate 16 is inserted through the slide shaft 13 with the compression spring 15 interposed therebetween and the base 12. That is, the movable plate 16 is supported in a state of being biased upward by the compression spring 15.

[0024] The movable plate 16 in this embodiment also has a hole in the center in the left-right direction, and the rotary driver unit 10 is inserted into this hole with the driver bit 11 facing downward. The rotary driver unit 10 inserted into this hole is then tightened with a setscrew S1, whereby the insert insertion tool 2 is held by the movable plate 16. As shown in the figure, the insert insertion tool 2 held by the movable plate 16 is inserted into the through-hole 12a of the base 12.

[0025] An optical sensor 17 is attached to the right side of the movable plate 16. The optical sensor 17 is U-shaped in plan view, with a light emitting section provided on one of two opposing protrusions, and a light receiving section that outputs an electrical signal when light is received on the other. If there is an obstruction between the two opposing protrusions of the optical sensor 17, the emitted light is blocked and the light receiving section cannot receive the light, and the output electrical signal changes. This allows detection of whether or not an obstruction exists between the light emitting section and the light receiving section. The above-mentioned shielding plate 14 is attached to the base 12 so as to be located between the front and rear parts of the optical sensor 17.

[0026] As described above, the movable plate 16 is movable in the vertical direction relative to the slide shaft 13. In other words, the movable plate 16 to which the insert insertion tool 2 is attached is not fixed in the vertical direction, but is stationary at a position where the weight of the movable plate 16, the insert insertion tool 2, etc., is balanced with the biasing force of the compression spring 15, so that it is kept in a floating state, so to speak. Therefore, when an upward or downward force is applied to the insert insertion tool 2 in this state, even if the magnitude of the force is minute, the insert insertion tool 2 moves upward or downward relative to the base 12, and therefore the applied force can be absorbed.

[0027] When the insert i is not inserted into the female screw portion T of the workpiece W, the movable plate 16 is relatively far away from the base 12 as shown in FIG. 2, and the shielding plate 14 is not blocking the light from the light emitting portion of the optical sensor 17. On the other hand, when the insert i is being inserted into the female screw portion T as shown in FIG. 6(d), the movable plate 16 approaches the base 12, and the shielding plate 14 blocks the light from the light emitting portion of the optical sensor 17. Note that the position where the shielding plate 14 blocks the light from the light emitting portion of the optical sensor 17 as shown in FIG. 6(d) is set at the point where a predetermined amount of the insert i is inserted into the female screw portion T.

[0028] Note that the shielding plate 14 and the optical sensor 17 of the present embodiment correspond to the "arrival sensor" in this specification. Also, the base 12, the slide shaft 13, and their peripheral members correspond to the "fixed portion" in this specification, and the movable plate 16 and its peripheral members correspond to the "movable portion" in this specification.

[0029] Next, the robot 4 will be described. The robot 4 of the present embodiment includes a robot base 18, a pair of columns 19 provided on the left and right of the robot base 18, and an arm 20 spanned across the columns 19 as shown in FIG. 1. A teaching / operation device 21 used when an operator inputs teaching data (teaching data) or performs various operations is provided on the robot base 18. The robot 4 also includes an X table 22 provided on the upper surface of the robot base 18 for moving the workpiece W in the X-axis direction. Further, the robot 4 includes a Z unit 23 to which the base 12 of the insert insertion tool 2 is attached for moving the insert insertion tool 2 in the Z-axis direction, and a Y unit 24 that holds the Z unit 23 and is movable in the Y-axis direction with respect to the arm 20.

[0030] The robot 4 also includes a robot control unit 25 shown in FIG. 3. The robot control unit 25 is contemplated as the "control unit" in this specification. The robot control unit 25 is electrically connected to the X drive motor 22a, Z drive motor 23a, and Y drive motor 24a provided in the above-described X table 22, Z unit 23, and Y unit 24. The robot control unit 25 is also electrically connected to the above-described teaching / operation device 21 and a program / teaching data storage unit 26 that stores a program for operating the robot 4 and teaching data input from the teaching / operation device 21 and the like. Further, the robot control unit 25 is electrically connected to the above-described rotary driver motor 10a and optical sensor 17.

[0031] FIG. 4 shows an example of the teaching data stored in the program / teaching data storage unit 26. In the teaching data shown in FIG. 4, for each point number, the position coordinates of the X table 22, Y unit 24, and Z unit 23, the speed conditions during its movement, and the commands that the robot control unit 25 executes (outputs) after the movement are set. The numbers attached to the position coordinates XYZ shown in FIG. 5 and the numbers attached to the speed condition V mean that they correspond to the numbers attached to the point number P, and even if the attached numbers are different, the position coordinates and speed may not change. For example, the position coordinate Y1 at the point number P1 and the position coordinate Y2 at the point number P2 are the same position in the following description. Then, the robot control unit 25 reads this teaching data in the order of the point numbers and sequentially issues commands corresponding to each point number to cause the insert tool 2 and the robot 4 to execute a predetermined operation.

[0032] In addition, in the "Instructions" shown in FIG. 4, the operations of the rotary driver motor 10a indicated by the point numbers P0 to P4 and P6 indicate that they are automatically executed when the movement of the Z unit 23 or the like is completed. For example, when the command of the point number P1 is transmitted, the robot control unit 25 moves the X table 22 to the position X1, moves the Y unit 24 to the position Y1, moves the Z unit 23 to the position Z1, and then continues to rotate the rotary driver motor 10a. On the other hand, the robot control unit 25 of the present embodiment is configured to rotate the rotary driver motor 10a in the reverse direction when the optical sensor 17 is OFF (the light from the light emitting unit is blocked by the shielding plate 14) while the rotary driver motor 10a is ON (rotating). And the "Instruction" of the point number P5 indicates that after moving the X table 22 to the position X5, moving the Y unit 24 to the position Y5, and moving the Z unit 23 to the position Z5, the rotation operation of the rotary driver motor 10a at the point number P4 continues, and the rotary driver motor 10a is rotated in the reverse direction when the optical sensor 17 becomes OFF.

[0033] Next, the insert supply pallet 5 will be described. The insert supply pallet 5 of the present embodiment is provided on the upper surface of the robot base 18 as shown in FIG. 1. The insert supply pallet 5 is circular in plan view and includes a plurality of hole portions 5a into which the inserts i are inserted in a state where the inserts i are directed in the vertical direction.

[0034] Next, the process of inserting the insert i into the female screw portion T of the workpiece W by the insert insertion device 1 of the present embodiment will be described with reference to FIGS. 5 and 6.

[0035] First, at the start of the insertion operation, the X table 22 on which the work W is placed and the insert insertion tool 2 are waiting at the home position (the position X0 of the X table 22 in the X-axis direction, the positions Y0 and Z0 of the Y unit 24 and the Z unit 23 in the Y-axis and Z-axis directions) based on the teaching data of the point number P0 shown in FIG. 4. Also, in this state, the rotation driver motor 10a is OFF (rotation stopped), and the rotation of the driver bit 11 has stopped. And the optical sensor 17 is in the ON state (light from the light emitting part is detected by the light receiving part, and there is no object that blocks light between the light emitting part and the light receiving part). As described above, the robot control unit 25 of the present embodiment is configured to reverse the rotation driver motor 10a when the optical sensor 17 becomes OFF (light from the light emitting part is blocked by the shielding plate 14) while the rotation driver motor 10a is ON (rotating). However, since the rotation driver motor 10a is OFF at the point number P0, such an operation is not performed.

[0036] When the robot control unit 25 receives a work start command by an operation from the teaching / operation device 21, based on the teaching data of the point number P1 stored in the program / teaching data storage unit 26, it moves the X table 22 to the position X1 at the speed V1, and moves the Y unit 24 and the Z unit 23 to the positions Y1 and Z1 at the speed V1. After the movement, the driver bit 11 of the insert insertion tool 2 is positioned directly above one of the holes 5a into which the insert i in the insert supply pallet 5 is inserted (see Fig. 5(a)). Note that in the state where the robot 4 is moving the Y unit 24 and the Z unit 23 to the positions Y1 and Z1, the rotation of the rotary driver motor 10a is stopped, and the rotary driver motor 10a rotates after the Y unit 24 and the Z unit 23 have moved to the positions Y1 and Z1. That is, when the robot 4 moves the X table 22, the Y unit 24, and the Z unit 23, there is a possibility that the shielding plate 14 approaches the optical sensor 17 and the optical sensor 17 turns OFF due to vibrations generated by the robot 4 causing the movable plate 16 to move in the vertical direction. However, since the operation of rotating the rotary driver motor 10a in the reverse direction is performed when the rotary driver motor 10a is rotating, the operation of rotating the rotary driver motor 10a in the reverse direction is not performed in the immediately preceding state shown in Fig. 5(a).

[0037] Next, the robot control unit 25 lowers the Z unit 23 at a speed V2 based on the teaching data of the point number P2 stored in the program-teaching data storage unit 26 (see Fig. 5(b)). Since the rotary driver motor 10a is rotating during the lowering, the female-threaded portion provided on the inner peripheral portion of the insert i engages with the driver bit 11, and the driver bit 11 is drawn into the insert i. On the other hand, depending on the variation in the shape of the insert i and the posture of the insert i when it is supplied by the insert supply pallet 5, the amount by which the driver bit 11 is actually drawn into the insert i may deviate slightly from the lowering amount of the Z unit 23 based on the teaching data. However, since the movable plate 16 is in a state where it can move freely in the vertical direction, this deviation is absorbed and no excessive force is applied to the insert i from the movable plate 16. Then, as the screwing of the driver bit 11 and the insert i progresses, the hook 11a provided at the tip of the driver bit 11 engages with the notch N of the insert i. Then, when the Z unit 23 has moved to Z2, the robot control unit 25 stops the rotation of the rotary driver motor 10a.

[0038] Thereafter, the robot control unit 25 raises the Z unit 23 at a speed V3 based on the teaching data of the point number P3 stored in the program-teaching data storage unit 26 (see Fig. 5(c)). Even during the raising and even when the raising is completed and the insert i is lifted from the insert supply pallet 5 (see Fig. 5(d)), since the rotary driver motor 10a is OFF, the rotation of the rotary driver motor 10a is stopped. Therefore, even if the movable plate 16 moves in the vertical direction due to vibrations or the like generated in the robot 4, and as a result, the shielding plate 14 approaches the optical sensor 17 and the optical sensor 17 turns OFF, the operation of rotating the rotary driver motor 10a in the reverse direction is not performed.

[0039] Thereafter, the robot control unit 25 moves the insert insertion tool 2 at a speed V4 based on the teaching data of the point number P4 stored in the program / teaching data storage unit 26. As a result, the driver bit 11 with the insert i screwed thereon moves directly above the female screw portion T of the workpiece W. Note that when the driver bit 11 moves directly above the female screw portion T, since the rotary driver motor 10a is OFF, the operation of reversely rotating the rotary driver motor 10a is not performed. After moving the driver bit 11 directly above the female screw portion T, the robot control unit 25 turns ON the rotary driver motor 10a (the rotation direction is clockwise CW). As a result, the driver bit 11 with the insert i screwed thereon rotates clockwise (see Fig. 6(a)).

[0040] Next, the robot control unit 25 lowers the Z unit 23 at a speed V5 based on the teaching data of the point number P5 stored in the program / teaching data storage unit 26 (see Fig. 6(b)). Since the driver bit 11 rotates during the lowering, the male-threaded portion provided on the outer peripheral portion of the insert i and the female-threaded portion T of the workpiece W are screwed together, and the driver bit 11 holding the insert i is drawn into the female-threaded portion T at a speed proportional to the rotation speed of the driver bit 11 and the pitch amount p of the female-threaded portion T (see Fig. 6(b)). Here, the speed at which the driver bit 11 is drawn into the female-threaded portion T (insert drawing speed) is referred to as "speed Vα". In the present embodiment, the speed V5 at which the Z unit 23 descends is set to be higher than the speed Vα at which the driver bit 11 is drawn into the female-threaded portion T (that is, V5 > Vα). Since the speed V5 at which the Z unit 23 descends is different from the speed Vα at which the driver bit 11 is drawn into the female-threaded portion T in this way, the floating portion 3 functions and the distance between the base 12 and the movable plate 16 increases. That is, the distance d0 (see Fig. 6(a)) between the light-emitting portion of the optical sensor 17 and the upper end portion of the shielding plate 14 before the driver bit 11 is drawn into the female-threaded portion T increases as shown in Fig. 6(c) when the driver bit 11 is drawn into the female-threaded portion T. Here, the distance between the light-emitting portion of the optical sensor 17 and the upper end portion of the shielding plate 14 when the Z unit 23 has moved to the position Z5 based on the teaching data of the point number P5 is referred to as "distance d1". Note that the position of the thread start portion in the female-threaded portion T (the position where the thread groove starts at the opening of the female-threaded portion T on the surface of the workpiece W) and the position of the thread start portion in the male-threaded portion provided on the outer peripheral portion of the insert i (the position where the thread crest starts at the tip of the insert i facing the workpiece W) are not necessarily at the same place every time. Also, even when the position of the thread start portion in the female-threaded portion T and the position of the thread start portion in the male-threaded portion provided on the outer peripheral portion of the insert i match, for example, due to the machining accuracy of the female-threaded portion T or the insert i, etc., the insert i and the female-threaded portion T may start to be screwed together after the driver bit 11 rotates several times. That is, the amount by which the driver bit 11 is actually drawn into the female-threaded portion T may deviate somewhat from the descending amount of the Z unit 23 based on the teaching data, so the distance d1 is not necessarily constant.

[0041] As described above, even after the Z unit 23 has moved to the position Z5 based on the teaching data of the point number P5, the rotational operation of the rotary driver motor 10a continues. Therefore, the driver bit 11 holding the insert i is drawn into the female screw portion T at the speed Vα. Accordingly, the distance d1 between the light emitting portion of the optical sensor 17 and the upper end portion of the shielding plate 14 shown in FIG. 6(c) decreases.

[0042] FIG. 6(d) shows a state in which the driver bit 11 holding the insert i is further drawn into the female screw portion T and the insert i is inserted into the female screw portion T by a predetermined amount. The shielding plate 14 of the present embodiment is set to block the light from the light emitting portion of the optical sensor 17 when the insert i is inserted into the female screw portion T by a predetermined amount in this way. Therefore, since it is detected that the signal from the optical sensor 17 has changed in the state shown in FIG. 6(d), the robot control unit 25 reversely rotates the rotary driver motor 10a (from clockwise CW to counterclockwise CCW) at this timing. As a result, only the driver bit 11 starts to rise with the insert i engaged with the female screw portion T.

[0043] That is, as described above, when the Z unit 23 moves to the position Z5 based on the teaching data of the point number P5, the amount by which the driver bit 11 is actually drawn into the female screw portion T may deviate slightly from the descending amount of the Z unit 23 based on the teaching data. However, in the insert insertion device 1 of the present embodiment, since the driver bit 11 starts to disengage from the insert i when the insert i is inserted into the female screw portion T by a predetermined amount, it is not affected by the above-described positional deviation. Therefore, according to the insert insertion device 1 of the present embodiment, the insert i can be accurately inserted to a position determined with respect to the female screw portion T.

[0044] The robot control unit 25 reversely rotates the rotary driver motor 10a and simultaneously raises the Z unit 23 at a speed V6 based on the teaching data of point number P6 stored in the program and teaching data storage unit 26 (see Fig. 6(d)). Then, when the driver bit 11 detaches from the insert i, the floating unit 3 returns to its initial state as shown (see Fig. 6(e)). Note that the timing for raising the Z unit 23 does not necessarily have to be simultaneous with the reverse rotation of the rotary driver motor 10a. However, the later the timing for raising the Z unit 23 becomes, the more the movable plate 16 rises with respect to the base 12. Therefore, it is preferable to raise the Z unit 23 at an appropriate timing.

[0045] When the raising of the Z unit 23 is completed, the robot control unit 25 turns off the rotary driver motor 10a, and one operation of inserting the insert i into the workpiece W is completed. If the operation of inserting the next insert i is subsequently performed, the robot control unit 25 executes the steps of point numbers P1 to P6 again. After all operations are completed, the robot control unit 25 executes the step of point number P0 and notifies the operator that all operations are completed.

[0046] As described above, embodiments embodying the present invention have been exemplified. However, the present invention is not limited to such specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims, unless otherwise particularly limited in the above description. For example, the configurations of the above-described embodiments can be added or deleted as appropriate, and the configuration of one embodiment can also be provided in another embodiment. Also, the effects in the above embodiments are merely examples of the effects resulting from the present invention, and it does not mean that the effects of the present invention are limited to the above effects.

[0047] For example, in the above-described embodiment, the arrival sensor was composed of the shielding plate 14 and the optical sensor 17. However, any sensor that can identify that the base 12 (or the Z unit 23) and the movable plate 16 (or the insert insertion tool 2) have reached a predetermined distance may be used, and the configuration is not limited to the above. The arrival sensor may use, for example, a contact switch, a linear encoder, a laser distance meter, or a configuration that measures the distance between the base 12 (or the Z unit 23) and the movable plate 16 (or the insert insertion tool 2) using a camera (image recognition device) or the like.

[0048] Also, in the above-described embodiment, the descending speed V5 of the Z unit 23 was set to be faster than the speed Vα at which the driver bit 11 is drawn into the female screw portion T (i.e., V5 > Vα). However, the same effect can be achieved by other methods. For example, by setting V5 = Vα and changing the timing of operating each part, the above-described effect can be obtained. Specifically, for example, when the Z unit 23 is lowered at the speed V5 based on the teaching data of the point number P5 (see Fig. 6(b)), after setting V5 = Vα, the rotation of the rotary driver motor 10a is started a predetermined time after the lower end of the insert i contacts the female screw portion T, and the above-described effect can be obtained.

[0049] And the teaching data in the above-described embodiment was teaching data mainly based on points (position information) as shown in Fig. 4. However, it may be teaching data and a drive program in a so-called robot language mainly based on command information, for example.

[0050] Also, in the above-described embodiment, the relative position of the base 12 and the movable plate 16 approaches the initial state, so that the shielding plate 14 blocks the light of the optical sensor 17 and the signal from the optical sensor 17 changes. However, the configuration is not limited to this, and for example, the configuration shown in Fig. 7 may be used.

[0051] In the embodiment shown in FIG. 7, the floating portion 30 includes a base 31 attached to the Z unit 23. The base 31 is plate-shaped, and a circular through-hole 31a is provided at the center in the left-right direction thereof. Further, the base 31 has circular holes on both the left and right sides sandwiching the through-hole 31a, and a columnar slide shaft 32 is inserted into these holes so as to be movable in the vertical direction. And the above-described optical sensor 17 is attached to the right side surface of the base 31.

[0052] The floating portion 30 includes a movable plate 33 located below the base 31. The movable plate 33 has a hole into which the rotary driver portion 10 is inserted at the center in the left-right direction, and on the left and right of this hole, it has two holes to which two slide shafts 32 are respectively attached. The rotary driver portion 10 and the two slide shafts 32 are held by the movable plate 33 by being tightened with set screws S1. And a shielding plate 34 is provided on the right side surface of the movable plate 33.

[0053] Further, the floating portion 30 includes coiled tension springs 35 respectively inserted into two slide shafts 13 and connecting the movable plate 33 and the base 31. That is, the embodiment shown in FIG. 2 has a configuration in which the movable plate 16 floats with respect to the base 12 via the compression spring 15, while the embodiment shown in FIG. 7 has a configuration in which the movable plate 33 is suspended with respect to the base 31 via the tension spring 35.

[0054] In the embodiment shown in FIG. 7, as shown in FIGS. 6(a) and 6(b), just before the insert i is inserted into the female screw portion T of the work W, the light from the light emitting portion of the optical sensor 17 is blocked by the shielding plate 34. However, as shown in FIG. 6(c), when the driver bit 11 holding the insert i is drawn into the female screw portion T, the light from the light emitting portion of the optical sensor 17 is received by the light receiving portion. That is, in the embodiment shown in FIG. 7, by reversing the rotation of the rotary driver motor 10a at the timing when the signal from the optical sensor 17 changes from OFF to ON, the same operation as the above-described embodiment can be realized.

[0055] In the above-described embodiment, the electrical connection of each part was as shown in the block diagram of FIG. 3, but it may be configured as shown in FIG. 8. In the embodiment shown in FIG. 8, the insert insertion tool 2 includes a torque sensor 10b that detects the load when the rotary driver motor 10a rotates. Also, the "command" at point number P5 is set to reverse-rotate the rotary driver motor 10a when the signal at the optical sensor 17 changes and the torque of the rotary driver motor 10a detected by the torque sensor 10b is within a predetermined range. For example, when the insert i is not properly inserted into the female screw portion T of the workpiece W, the load when the rotary driver motor 10a rotates increases. Therefore, by configuring as shown in FIG. 8, the operation can be continued only when the insert i is properly inserted into the female screw portion T of the workpiece W. In addition, in the case of any of the block diagrams shown in FIGS. 3 and 8, since an error is configured to be notified when the signal at the optical sensor 17 does not change even after a predetermined time has elapsed in the operation at point number P5, there will be no problem such as rotating the insert i more than necessary. Also, such error notification may be configured to be issued when the torque detected by the torque sensor 10b exceeds a predetermined range. Further, instead of the torque sensor 10b, the load when the rotary driver motor 10a rotates may be detected by detecting the current value consumed by the rotary driver motor 10a.

Explanation of Reference Numerals

[0056] 1: Insert insertion device 2: Insert insertion tool 3, 30: Floating part 4: Robot 10a: Rotary driver motor 10b: Torque sensor 11: Driver bit (male screw portion) 12, 31: Base (fixed part) 14, 34: Shielding plate (arrival sensor) 16: Movable plate (movable part) 17: Optical sensor (proximity sensor) 25: Robot control unit (control unit) T: Female screw part W: Workpiece i: Insert

Claims

1. An insert insertion device comprising: an insert insertion tool having a male screw portion that screws into a coiled insert and a rotary driver motor that rotates the male screw portion; a robot that lowers the insert insertion tool with respect to a female screw portion provided on a workpiece; and a floating portion having a movable portion having the insert insertion tool and a fixed portion held by the robot and supporting the movable portion so as to be movable in the vertical direction. An arrival sensor that detects that the distance between the movable portion and the fixed portion has reached a predetermined value and outputs a signal. A control unit connected to the rotary driver motor and the arrival sensor. The control unit reverses the rotation direction of the rotary driver motor when it is detected by a signal from the arrival sensor that the distance between the movable portion and the fixed portion has reached a predetermined value when the rotary driver motor is rotated to screw the insert into the female screw portion. The insert insertion device described above.

2. The control unit drives the robot to raise the insert insertion tool when it is detected by a signal from the arrival sensor that the distance between the movable portion and the fixed portion has reached a predetermined value while the rotary driver motor is rotating. The insert insertion device according to claim 1.

3. The control unit drives the robot so that the insert insertion tool descends at a speed faster than the insert drawing speed calculated from the rotation speed of the male screw portion and the screw pitch of the insert when screwing the insert into the female screw portion. The insert insertion device according to claim 1.

4. The control unit drives the robot so that the insert insertion tool descends before rotating the rotary driver motor when screwing the insert into the female screw portion. The insert insertion device according to claim 1.

5. Further comprising a torque sensor connected to the control unit and outputting a signal for detecting the torque of the rotary driver motor. The control unit reverses the rotation direction of the rotary driver motor when it is detected by a signal from the torque sensor that the torque value of the rotary driver motor is within a predetermined range and by a signal from the arrival sensor that the distance between the movable portion and the fixed portion has reached a predetermined value. The insert insertion device according to claim 1.

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