Insert insertion device

Abstract

We propose an insert insertion device that prevents damage to the workpiece during insert insertion and allows for precise insertion of the insert. [Solution] The insert insertion device 1A comprises a rotating male screw portion 12 and a robot 3 that moves the male screw portion 12, and inserts a coil-shaped insert i wound by the male screw portion 12 into a female screw portion provided on the workpiece W. The device includes a sensor 27 that detects the relative position between the insert i wound by the male screw portion 12 and the male screw portion 12, and a determination unit 21a that determines whether the relative position is within a predetermined range based on pre-insertion information output from the sensor 27 after the insert i has been wound by the male screw portion 12 and before the insert i has been inserted into the female screw portion.

Description

Technical Field

[0001] The present invention relates to an insert insertion device for inserting a coil-shaped insert into a female screw portion provided on a workpiece.

Background Art

[0002] When fastening a member with a screw to a base material having relatively low strength such as a light metal or a resin, by previously attaching an insert to the female screw portion of the base material, it is possible to reduce the load on the base material during screw fastening, prevent damage to the base material, and increase 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 process 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 on the inner peripheral portion of the insert are screwed together to engage the driver bit and the insert. Then, in that state, the insertion tool is moved to the workpiece, and while inserting the insert into the female screw portion provided on the workpiece, the male screw portion of the insertion tool is rotated to engage the male screw-shaped portion on the outer peripheral portion of the insert with the female screw portion of the workpiece. After that, the driver bit is rotated in the reverse direction to disengage the insertion tool from the insert, thereby completing the insertion of the insert into the workpiece.

[0004] In this way, in the insert insertion process, first, an operator or a work 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 unnecessary force is applied. If the insert is deformed, it cannot be normally inserted into the workpiece, and there is also a concern that the workpiece may be damaged during insertion.

[0005] As a device capable of confirming the insertion state of an insert into a workpiece, the device described in Patent Document 2 is known. Patent Document 2 discloses a coil insert insertion inspection device that includes a forward / backward detection means for detecting the amount of forward / backward movement of a detection shaft provided with a male screw portion at its tip, and can determine insert insertion defects, etc., based on the amount of forward / backward movement. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Special Publication No. 04-038543 [Patent Document 2] Japanese Patent Publication No. 2021-10965 [Overview of the project] [Problems that the invention aims to solve]

[0007] The device described in Patent Document 2 determines whether the insert has been inserted properly by screwing the male threaded portion of the detection shaft into the female threaded portion of the workpiece. In other words, the device described in Patent Document 2 determines whether the insert has been inserted properly when the insert has already been inserted into the workpiece, and therefore is not effective in preventing damage to the workpiece when inserting the insert.

[0008] In view of these points, the present invention aims to provide an insert insertion device that can insert an insert into a workpiece with high precision while preventing damage to the workpiece. [Means for solving the problem]

[0009] The present invention relates to an insert insertion device comprising a rotating male screw portion and a robot for moving the male screw portion, for inserting a coil-shaped insert wound by the male screw portion into a female screw portion provided on a workpiece, characterized in that it comprises a sensor for detecting the relative position between the insert wound by the male screw portion and the male screw portion, and a determination unit for determining whether the relative position is within a predetermined range based on pre-insertion information output from the sensor after the insert has been wound by the male screw portion and before the insert has been inserted into the female screw portion. [Effects of the Invention]

[0010] According to the insert insertion device of the present invention, before inserting the insert into the female thread portion of the workpiece, it is determined whether the pre-insertion information output from the sensor falls within a predetermined range. In other words, if the relative position between the wound insert and the male thread portion is poor, the insert will not be inserted into the workpiece. Only when the relative position between the two is good the insert can it be inserted into the workpiece. This prevents damage to the workpiece and allows for accurate insertion of the insert. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram relating to a first embodiment of an insert insertion device according to the present invention. [Figure 2] Figure 1 is a schematic diagram of the insert supply pallet (the hatched area is a cross-section shown by cutting out a portion of the pallet to indicate the inside of the hole). [Figure 3] Figure 1 is a block diagram of the insert insertion device shown. [Figure 4A] This is an explanatory diagram showing the positional relationship between the light-receiving part of the sensor and the insert wound around the male screw part (showing the state where light from the light-emitting part of the sensor is received by the light-receiving part). [Figure 4B] This is an explanatory diagram showing the positional relationship between the light-receiving part of the sensor and the insert wound around the male screw part (in a state where light from the light-emitting part of the sensor is blocked). [Figure 5A]It is an explanatory diagram regarding the process of winding an insert in the insert insertion device shown in FIG. 1 with a male screw portion. [Figure 5B] It is an explanatory diagram regarding the process subsequent to that shown in FIG. 5A. [Figure 5C] It is an explanatory diagram regarding the process subsequent to that shown in FIG. 5B. [Figure 5D] It is an explanatory diagram regarding the process subsequent to that shown in FIG. 5C. [Figure 6A] It is an explanatory diagram showing the state of detecting the insert wound with the male screw portion by the sensor shown in FIG. 4A (the relative position between the insert and the male screw portion is good). [Figure 6B] It is an explanatory diagram showing the state of detecting the insert wound with the male screw portion by the sensor shown in FIG. 4A (the insert is underwound with respect to the male screw portion and the relative position is poor). [Figure 6C] It is an explanatory diagram showing the state of detecting the insert wound with the male screw portion by the sensor shown in FIG. 4A (the insert is overwound with respect to the male screw portion and the relative position is poor). [Figure 7A] It is an explanatory diagram regarding the process of inserting the insert in the insert insertion device shown in FIG. 1 into the workpiece. [Figure 7B] It is an explanatory diagram regarding the process subsequent to that shown in FIG. 7A. [Figure 7C] It is an explanatory diagram regarding the process subsequent to that shown in FIG. 7B. [Figure 7D] It is an explanatory diagram regarding the process subsequent to that shown in FIG. 7C. [Figure 8] It is a schematic diagram regarding the second embodiment of the insert insertion device according to the present invention. [Figure 9] It is a schematic diagram of the floating mechanism shown in FIG. 8. [Figure 10] It is a block diagram of the insert insertion device shown in FIG. 8. [Figure 11] It is a schematic diagram of the insert supply pallet shown in FIG. 8 (the hatched part is a cross-section shown by cutting a part to show the inside of the hole). [Figure 12A]An explanatory diagram (a diagram corresponding to FIG. 13A) regarding the step of detecting a change in the relative position between a movable part and a fixed part with a sensor. [Figure 12B] An explanatory diagram (a diagram corresponding to FIG. 13B) regarding the step subsequent to that shown in FIG. 12A. [Figure 12C] An explanatory diagram (a diagram corresponding to FIG. 13B) regarding the step subsequent to that shown in FIG. 12B. [Figure 13A] An explanatory diagram regarding the detection recess in the insert supply pallet shown in FIG. 11 (state where the insert wound around the male screw part is positioned directly above the detection recess). [Figure 13B] An explanatory diagram regarding the detection recess in the insert supply pallet shown in FIG. 11 (state where the insert wound around the male screw part contacts the upper surface of the insert supply pallet provided with the detection recess). [Figure 14A] An explanatory diagram showing the state of detecting a change in the relative position between an insert and a male screw part via a floating mechanism with the sensor shown in FIG. 13A (the relative position between the insert and the male screw part is good). [Figure 14B] An explanatory diagram showing the state of detecting a change in the relative position between an insert and a male screw part via a floating mechanism with the sensor shown in FIG. 13A (the insert is under-wound with respect to the male screw part and the relative position is poor). [Figure 14C] An explanatory diagram showing the state of detecting a change in the relative position between an insert and a male screw part via a floating mechanism with the sensor shown in FIG. 13A (the insert is over-wound with respect to the male screw part and the relative position is poor). [Figure 15A] An explanatory diagram regarding the step of inserting an insert into a workpiece with the insert insertion device shown in FIG. 8. [Figure 15B] An explanatory diagram regarding the step subsequent to that shown in FIG. 15A. [Figure 15C] An explanatory diagram regarding the step subsequent to that shown in FIG. 15B. [Figure 15D] An explanatory diagram regarding the step subsequent to that shown in FIG. 15C. [Figure 15E]This is an explanatory diagram of the process that follows Figure 15D. [Figure 15F] This is an explanatory diagram of the process that follows Figure 15E. [Figure 16A] Figure 11 is an explanatory diagram illustrating a modified example of the insert supply pallet shown. [Figure 16B] Figure 16A is an exploded perspective view of the insert supply pallet (the hatched area is a cross-section shown by cutting a portion of it to reveal the inside of the through-hole). [Modes for carrying out the invention]

[0012] Hereinafter, an embodiment of the insert insertion device according to the present invention will be described with reference to the drawings. For convenience, the following description will refer to the right, left, front, rear, up, down, and X, Y, and Z directions shown in the drawings.

[0013] First, the configuration of the insert insertion device 1A, which is a first embodiment of the insert insertion device according to the present invention, will be described with reference to Figures 1 to 3. The insert insertion device 1A consists of an insert insertion tool 2, a robot 3 that moves the insert insertion tool 2 and the workpiece W in three dimensions relative to each other, and an insert supply pallet 4A that supplies inserts i to the insert insertion tool 2.

[0014] As shown in Figure 2, the insert insertion tool 2 comprises a rotary driver unit 11 with a rotary driver motor 10 (see Figure 3) built in, and a driver bit 12 that rotates with the rotary driver motor 10. As shown in Figure 5A, the driver bit 12 has a male screw shape that fits into a female screw-shaped portion provided on the inside of the insert i, and is the portion corresponding to the "male screw portion" in this specification. The tip of the driver bit 12 is provided with a hook 12a that engages with a concave notch N provided on the inside of the insert i. The hook 12a is movable radially inward and outward relative to the driver bit 12 and is biased radially outward. Here, as shown in Figures 5C and 5D, the state in which the hook 12a engages with the notch N relative to the driver bit 12 and the insert i is wound to the desired position is referred to as the normal insert winding state.

[0015] As shown in Figure 1, robot 3 comprises a robot base 13, a pair of columns 14 located on the left and right sides of the robot base 13, and an arm 15 stretched across the columns 14. The robot base 13 is equipped with a teaching and operation device 16 used by the operator when inputting teaching data and performing various operations. Robot 3 also includes an X-table 17 located on the upper surface of the robot base 13 for moving the workpiece W in the X-axis direction. Furthermore, robot 3 includes a Z-unit 19 that holds a base 18 to which an insert insertion tool 2 is attached and moves the insert insertion tool 2 in the Z-axis direction, and a Y-unit 20 that holds the Z-unit 19 and is movable in the Y-axis direction relative to the arm 15.

[0016] Furthermore, robot 3 is equipped with a robot control unit 21 (see Figure 3) for controlling each part of the insert insertion device 1A. As will be described later, the robot control unit 21 is equipped with a determination unit 21a that makes various judgments as to whether or not the insert i has been wound onto the driver bit 12 as intended. The detailed functions of the determination unit 21a will be described later.

[0017] In this embodiment, the robot control unit 21 is electrically connected to the rotary driver motor 10 described above, as well as to the X drive motor 22, Z drive motor 23, and Y drive motor 24 provided on the X table 17, Z unit 19, and Y unit 20, respectively. The robot control unit 21 is also electrically connected to the teaching and operation device 16 described above, and to the program / teaching data storage unit 25, which stores the program for operating the robot 3 and teaching data input from the teaching and operation device 16, etc. The program / teaching data storage unit 25 also stores reference data used when the judgment unit 21a makes various judgments. Furthermore, the robot 3 is equipped with a notification unit 26 for informing the operator of the operating status of the robot 3. The notification unit 26 may convey information to the operator visually, such as a display, or it may convey information to the operator auditorily, such as a buzzer or speaker. The notification unit 26 is electrically connected to the robot control unit 21.

[0018] As shown in Figure 2, the insert supply pallet 4A in this embodiment comprises a rectangular parallelepiped pallet body 4a and a plurality of circular holes 4b provided on the upper surface of the pallet body 4a. Each of the plurality of holes 4b accommodates an insert i. In this embodiment, the insert supply pallet 4A is provided on the upper surface of the robot base 13 as shown in Figure 1, and more specifically, in a plan view, it is provided at a position where the centers of the plurality of holes 4b coincide with the movement trajectory of the driver bit 12 when the insert insertion tool 2 is moved left and right by the Y unit 20. As will be described later, the insert i housed in the holes 4b is wound up by the driver bit 12 and then pulled up from the holes 4b by the driver bit 12.

[0019] The insert supply pallet 4A is also equipped with a position sensor 27, which corresponds to the "sensor" in this specification. In this embodiment, the position sensor 27 has a light-emitting part (not shown) that emits detection light and a light-receiving part 27a facing the light-emitting part, and is U-shaped in plan view. When the light-receiving part 27a receives detection light, it outputs an electrical signal, or when the light-receiving part 27a receives detection light, the value of the output electrical signal changes (or the output electrical signal stops). The straight line connecting the light-emitting part and the light-receiving part 27a shown in Figure 2 is the optical axis L of the detection light. The position sensor 27 in this embodiment is provided on the upper surface of the insert supply pallet 4A, and more specifically, in a plan view, it is provided at a position where the optical axis L of the detection light intersects with the movement trajectory of the driver bit 12 when the insert insertion tool 2 is moved left and right by the Y unit 20. The position sensor 27 is also electrically connected to the robot control unit 21 as shown in Figure 3. With such a position sensor 27, if an object is interposed between the light-emitting unit and the light-receiving unit 27a, and this blocks the detection light that was being received by the light-receiving unit 27a, the output state of the electrical signal changes, making it possible to detect whether or not there is an object blocking the detection light between the light-emitting unit and the light-receiving unit 27a.

[0020] The position sensor 27 is capable of detecting the insert i wound up by the driver bit 12. The determination unit 21a is also capable of measuring the time from when the driver bit 12 begins to descend toward the position sensor 27 until the position sensor 27 detects the insert i. This point will be explained with reference to Figures 4A and 4B.

[0021] Under the control of the robot control unit 21, the driver bit 12 winds up the insert i housed in the hole 4b and moves upward, then moves in the Y direction by the Y unit 20, moving to above the position sensor 27 as shown in Figure 4A. At this time, the Y-direction positional relationship between the driver bit 12 and the position sensor 27 is set such that the optical axis L of the detection light is located outside the maximum outer diameter portion of the screw-shaped driver bit 12, while the insert i is located directly above the optical axis L. Furthermore, the Z-direction positional relationship between the driver bit 12 and the position sensor 27 at this time is set such that, in the above-described normal insert winding state, the height from the optical axis L to the insert i located directly above the optical axis L is Ha. Note that the height Ha is a design value, and the actual height from the optical axis L to the insert i will vary somewhat from the height Ha due to errors in the shape of individual inserts i, and because the circumferential position of the insert i at the point directly above the optical axis L (the position of the starting end of the spirally extending insert i) is not uniquely determined.

[0022] After the state shown in Figure 4A, the robot control unit 21 lowers the Z unit 19 at a speed Va. As a result, the driver bit 12 with the insert i wound up also lowers, and as shown in Figure 4B, the insert i blocks the light detected by the position sensor 27. Note that the rotation of the driver bit 12 stops when it is lowered. At this time, the determination unit 21a measures the time Ta until the output state of the electrical signal from the position sensor 27 changes, using the state shown in Figure 4A as the starting point.

[0023] Here, the program / teaching data storage unit 25 stores the time information Ta described above. Note that the actual height from the optical axis L to the insert i will vary somewhat from the height Ha set above. For this reason, the time information Ta is set with a range as long as the insertion of the insert i into the workpiece W, which will be described later, is performed normally. Hereinafter, this range of time Ta with a range will be referred to as the first insertable time range. The first insertable time range is stored in the program / teaching data storage unit 25.

[0024] Such an insert insertion device 1A can insert the insert i into the workpiece W using the procedure shown in Figures 5A to 7D.

[0025] First, the insert insertion device 1A drives the Y drive motor 24 based on the control of the robot control unit 21 to move the insert insertion tool 2 so that the driver bit 12 is positioned directly above the hole 4b in which the insert i is housed (see the insert insertion tool 2 on the right in Figure 2 and Figure 5A).

[0026] Next, the robot control unit 21 rotates the rotary driver motor 10 and drives the Z drive motor 23 to lower the Z unit 19. As a result, the driver bit 12 rotates and contacts the top of the insert i, as shown in Figure 5B, and the female threaded portion on the inner circumference of the insert i is wound onto the driver bit 12. As shown in Figure 5C, the hook 12a of the driver bit 12 engages with the notch N of the insert i, and the insert i is wound onto the driver bit 12 to the desired position (insert normal winding state). Subsequently, the robot control unit drives the Z drive motor 23 to raise the Z unit 19, causing the insert i to rise from the hole 4b together with the driver bit 12, as shown in Figure 5D.

[0027] Subsequently, the robot control unit 21 drives the Y drive motor 24 to move the driver bit 12 above the position sensor 27 (see the insert insertion tool 2 on the left in Figure 2 and Figure 6A). In Figure 6A, the insert i is wound onto the driver bit 12 in the normal winding state, and the wound insert i is positioned at a height h1 from the optical axis L. The height h1 is a height that falls within the range of variation in height Ha mentioned above. Then, with the rotation of the driver bit 12 stopped, the robot control unit 21 drives the Z drive motor 23 to lower the Z unit 19 at a speed Va. The determination unit 21a measures the time t1 from when the Z unit 19 begins to descend until the output state of the electrical signal from the position sensor 27 changes, and determines whether this time t1 falls within the first insertable time range stored in the program / teaching data storage unit 25. As mentioned above, the height h1 is a height that falls within the range of variation in height Ha, and therefore, the time t1 falls within the first insertable time range. Therefore, the determination unit 21a determines that the measured time t1 falls within the first insertable time range. Based on the determination by the determination unit 21a, the robot control unit 21 determines that the state shown in Figure 6A allows for the normal insertion of the insert i into the workpiece W and proceeds with the insertion process of the insert i into the workpiece W, which will be described later.

[0028] Furthermore, the insert i is not always wound onto the driver bit 12 in the correct winding state. For example, even if the driver bit 12 contacts the top of the insert i, it may rotate freely for a while, resulting in a state where the insert i is not completely wound onto the driver bit 12 (hereinafter referred to as the under-winding state), as shown in Figure 6B. Alternatively, the driver bit 12 may rotate onto the insert i even after the hook 12a engages with the notch N, resulting in a state where the insert i is excessively wound onto the driver bit 12 (hereinafter referred to as the over-winding state), as shown in Figure 6C. If an attempt is made to insert the insert i into the workpiece W in such an under-winding state, a part of the insert i may deform during insertion, potentially damaging the workpiece W. Similarly, if an attempt is made to insert the insert i into the workpiece W in an over-winding state, a part of the driver bit 12 may contact the bottom of the female thread before the insert i is fully inserted into the female thread of the workpiece W, also potentially damaging the workpiece W. However, the insert insertion device 1A of this embodiment can prevent such problems with the judgment unit 21a.

[0029] In the under-winding state shown in Figure 6B, the insert i wound by the driver bit 12 is positioned at a height h2 from the optical axis L. Note that height h2 is lower than the range of variation at height Ha. When the robot control unit 21 drives the Z drive motor 23 to lower the Z unit 19 at speed Va, the judgment unit 21a measures the time t2 from when the Z unit 19 begins to descend until the output state of the electrical signal from the position sensor 27 changes, and determines whether time t2 is included in the first insertable time range stored in the program / teaching data storage unit 25. Time t2 is the value obtained by dividing height h2 by speed Va (t2 = h2 / Va), and since height h2 is lower than the range of variation at height Ha, time t2 is shorter than the first insertable time range. Therefore, the judgment unit 21a determines that the measured time t2 is not included in the first insertable time range. Based on this determination, the robot control unit 21 of this embodiment temporarily suspends its operation, determining that the state shown in Figure 6B prevents the insertion of the insert i into the workpiece W from being performed correctly. It then activates the notification unit 26 to inform the operator that the insert i has not been properly wound onto the driver bit 12.

[0030] Furthermore, in the overwinding state shown in Figure 6C, the insert i wound by the driver bit 12 is located at a height h3 from the optical axis L. Note that height h3 is higher than the range of variation at height Ha. When the robot control unit 21 drives the Z drive motor 23 to lower the Z unit 19 at speed Va, the judgment unit 21a measures the time t3 from when the Z unit 19 begins to descend until the output state of the electrical signal from the position sensor 27 changes, and determines whether time t3 is included in the first insertable time range stored in the program / teaching data storage unit 25. Time t3 is the value obtained by dividing height h3 by speed Va (t3 = h3 / Va), and since height h3 is higher than the range of variation at height Ha, time t3 is longer than the first insertable time range. Therefore, the judgment unit 21a determines that the measured time t3 is not included in the first insertable time range. Based on this determination, the robot control unit 21 in this embodiment temporarily suspends operation, determining that the state shown in Figure 6C prevents the insertion of the insert i into the workpiece W from being performed correctly. Furthermore, it activates the notification unit 26 to inform the operator that the insert i has not been properly wound onto the driver bit 12.

[0031] On the other hand, in the case of the insert in the normal winding state shown in Figure 6A, the robot control unit 21 performs the insert insertion process of the workpiece W shown in Figures 7A to 7D, based on the determination of the determination unit 21a that the measured time t1 falls within the first insertable time range. First, the robot control unit 21 drives the X drive motor 22 and the Y drive motor 24 to move the workpiece W and the insert insertion tool 2, positioning the driver bit 12 directly above the female screw portion of the workpiece W as shown in Figure 7A. Next, the robot control unit 21 drives the rotary driver motor 10 and the Z drive motor 23 to rotate and lower the driver bit 12 as shown in Figure 7B. As a result, the male screw-shaped portion provided on the outer circumference of the insert i is screwed into the female screw portion of the workpiece W. Furthermore, if the speed at which the Z-drive motor 23 drives the Z-unit 19 to lower the driver bit 12 differs from the speed at which the rotary driver motor 10 drives the insert i to screw into the female thread portion of the workpiece W, thereby drawing the insert i into the workpiece W, an excessive load will be placed on the insert i. For this reason, the speed at which the Z-unit 19 lowers is set to a speed calculated from the lead amount of the male thread-shaped portion of the insert i and the rotational speed of the driver bit 12.

[0032] Subsequently, the robot control unit 21 drives the rotary driver motor 10 and the Z drive motor 23 so that the driver bit 12 rotates in the reverse direction and rises, as shown in Figure 7C. The speed of the Z unit 19 when raising the driver bit 12 is calculated from the lead amount of the male screw-shaped part of the driver bit 12 and the rotation speed of the driver bit 12, so as not to put an excessive load on the insert i. As the driver bit 12 detaches from the insert i through this operation, the insert i can be inserted into the workpiece W, as shown in Figure 7D.

[0033] As described above, the determination unit 21a of the insert insertion device 1A of this embodiment measures the time from when the Z unit 19 begins to descend based on the electrical signal output from the position sensor 27 (corresponding to "pre-insertion information" in this specification) after the insert i has been wound up with the driver bit 12 and before the insert i is inserted into the female screw portion of the workpiece W, until the output state of the electrical signal from the position sensor 27 changes, and determines whether this time is included in the first insertable time range (corresponding to the "predetermined range" in this specification). In other words, if it is determined that the time obtained from the electrical signal from the position sensor 27 is not included in the first insertable time range, the process of notifying the operator that an abnormality has occurred without performing the process of inserting the insert i into the workpiece W can be carried out, so that damage to the workpiece W can be prevented even if the above-mentioned under-winding or over-winding conditions occur.

[0034] In conventional insert insertion devices, when the driver bit is rotated in reverse to detach it from the insert, there is a rare possibility that the insert inserted into the workpiece may not be removed from the driver bit and may be pulled up from the workpiece while still wound around the driver bit. In this regard, the insert insertion device 1A of this embodiment can detect this malfunction as follows.

[0035] After the process shown in Figure 7D, the robot control unit 21 moves the driver bit 12 above the position sensor 27 shown in Figure 6A. As described above, the Y-direction positional relationship between the driver bit 12 and the position sensor 27 in Figure 6A is such that the optical axis L of the detection light is located outside the maximum outer diameter portion of the male screw-shaped driver bit 12. The determination unit 21a also has a function to determine whether or not the output state of the electrical signal from the position sensor 27 changes when the Z unit 19 is lowered at a predetermined speed for a predetermined time. The "predetermined speed" and "predetermined time" for the Z unit 19 are appropriately selected under the condition that the insert i remains wound around the driver bit 12 without detaching from it, and that the insert i is detected by the position sensor 27 when the Z unit 19 is lowered from the position shown in Figure 6A.

[0036] The robot control unit 21 then lowers the Z unit 19 from the position shown in Figure 6A, and the determination unit 21a determines whether or not the output state of the electrical signal from the position sensor 27 changes. If the output state of the electrical signal from the position sensor 27 does not change, it can be determined that the insert i has been removed from the driver bit 12 and that the insert i has been properly inserted into the workpiece W. On the other hand, if the output state of the electrical signal from the position sensor 27 changes, it can be determined that the insert i has not been removed from the driver bit 12, so the robot control unit 21 temporarily stops its operation and activates the notification unit 26 to notify the operator that the insert i remains in the driver bit 12.

[0037] As described above, the determination unit 21a of the insert insertion device 1A of this embodiment determines whether the insert i has been removed from the driver bit 12 using the electrical signal output from the position sensor 27 (corresponding to "post-insertion information" in this specification) after inserting the insert i into the female screw portion of the workpiece W. In other words, if it is determined that the insert i has not been removed from the driver bit 12 when determined using the electrical signal from the position sensor 27, the operator can be notified that an abnormality has occurred, as described above, thereby preventing problems such as proceeding to the winding of a new insert i while the insert i remains on the driver bit 12.

[0038] Next, the configuration of insert insertion device 1B, which is a second embodiment of the insert insertion device according to the present invention, will be described with reference to Figures 8 to 11. Insert insertion device 1B includes the insert insertion tool 2 and robot 3 described above, and further includes a floating mechanism 5 provided between the insert insertion tool 2 and the robot 3. Insert insertion device 1B also includes an insert supply pallet 4B instead of the insert supply pallet 4A described above. Insert insertion device 1B is equipped with a reach sensor 35 shown in Figure 10, and the reach sensor 35 is electrically connected to a robot control unit 21 provided in the robot 3.

[0039] As shown in Figure 9, the floating mechanism 5 includes a floating base 30 attached to the Z unit 19 of the robot 3. The floating base 30 is plate-shaped and has a circular through hole 30a in its center in the left-right direction. The floating base 30 also has circular holes on both the left and right sides of the through hole 30a, and a cylindrical slide shaft 31 is attached to these holes in a vertically oriented manner. In this embodiment, the slide shaft 31 is held to the floating base 30 by a set screw S1. A shielding plate 32 is provided on the right side of the floating base 30. The shielding plate 32 in this embodiment has a portion attached to the right side of the floating base 30 and a plate-shaped portion extending upward from this portion.

[0040] The floating mechanism 5 also includes coil-shaped compression springs 33 that are inserted through each of the two slide shafts 31.

[0041] Furthermore, the floating mechanism 5 has two holes through which two slide shafts 31 are inserted, and is equipped with a movable plate 34 that can move vertically relative to the slide shafts 31. As shown in the figure, the movable plate 34 is inserted onto the slide shafts 31 with a compression spring 33 interposed between it and the floating base 30. That is, the movable plate 34 is supported while being biased upward by the compression spring 33.

[0042] In this embodiment, the movable plate 34 also has a hole in the center in the left-right direction, into which the rotary driver part 11 is inserted with the driver bit 12 facing downwards. The insert insertion tool 2 is held in place by the movable plate 34 by tightening the rotary driver part 11 inserted into this hole with the set screw S1. As shown in the figure, the insert insertion tool 2 held in place by the movable plate 34 is inserted through the through hole 30a of the floating base 30.

[0043] A reach sensor 35 is attached to the right side of the movable plate 34. Similar to the position sensor 27 described above, the reach sensor 35 has a light-emitting part that emits detection light and a light-receiving part opposite the light-emitting part, and is U-shaped in plan view. The electrical signal output changes depending on whether or not the detection light is received by the light-receiving part. A shielding plate 32 is positioned in the gap in the front-to-back direction of the U-shaped part of the reach sensor 35, and the reach sensor 35 is movable vertically relative to the shielding plate 32. That is, when the shielding plate 32 is interposed between the light-emitting part and the light-receiving part, the detection light that was being received by the light-receiving part is blocked by the shielding plate 32, and when the shielding plate 32 moves out from between the light-emitting part and the light-receiving part, the detection light is received by the light-receiving part. As a result, the output state of the electrical signal from the reach sensor 35 changes, and it is detected whether or not the shielding plate 32 is present between the light-emitting part and the light-receiving part.

[0044] In this embodiment, the vertical positional relationship between the shielding plate 32 and the arrival sensor 35 is such that, as shown in Figure 12A, when the insert i is wound onto the driver bit 12, the upper end of the shielding plate 32 is located at a distance d1 higher than the height at which the light-emitting and light-receiving parts of the arrival sensor 35 are located.

[0045] As described above, the movable plate 34 is movable vertically relative to the slide shaft 31. That is, the movable plate 34 to which the insert insertion tool 2 is attached is not fixed vertically, but remains stationary at a position where the weight of the movable plate 34 and the insert insertion tool 2, etc., balances with the biasing force of the compression spring 33, and is, so to speak, floating. Therefore, if an upward or downward force is applied to the insert insertion tool 2 in this state, even if the magnitude of the force is small, the insert insertion tool 2 will move upward or downward relative to the floating base 30, and thus can absorb the applied force.

[0046] In this embodiment, the shielding plate 32 and the arrival sensor 35 correspond to the term "sensor" as defined in this specification. Furthermore, the floating base 30, the slide shaft 31, and their surrounding members correspond to the term "fixed part" as defined in this specification, while the movable plate 34 and its surrounding members correspond to the term "movable part" as defined in this specification.

[0047] The insert supply pallet 4B, like the insert supply pallet 4A described above, comprises a pallet body 4a and a plurality of holes 4b. Each of the plurality of holes 4b accommodates an insert i. Similar to the insert supply pallet 4A, the insert supply pallet 4B is also positioned so that, in a plan view, the centers of the plurality of holes 4b coincide with the movement trajectory of the driver bit 12 when the insert insertion tool 2 is moved left and right by the Y unit 20, relative to the upper surface of the robot base 13.

[0048] Furthermore, the insert supply pallet 4B has a detection recess 36 that is circular in shape in plan view, located to the left of the leftmost hole 4b on the upper surface of the pallet body 4a. As shown in Figures 11, 12A, and 13A, the driver bit 12 is movable directly above the detection recess 36. The inner diameter D1 of the detection recess 36 is set to be larger than the outer diameter D2 of the maximum outer diameter of the male screw-shaped driver bit 12, and smaller than the outer diameter D3 of the insert i wound around the driver bit 12. Furthermore, the detection recess 36 corresponds to the "contact portion" in this specification. Since the detection recess 36 (insert supply pallet 4B) is attached to the robot base 13, it can be said to be an immovable component compared to the driver bit 12, which is movable relative to the workpiece W.

[0049] When the driver bit 12 is lowered, the insert i wound around the driver bit 12 comes into contact with the upper surface of the pallet body 4a where the detection recess 36 is provided. The shielding plate 32 and the arrival sensor 35 described above can detect the change in the relative position between the floating base 30 and the movable plate 34 that occurs when the insert i comes into contact with the upper surface of the pallet body 4a. The determination unit 21a can measure the time it takes for the relative position between the floating base 30 and the movable plate 34 to change by a predetermined amount, starting from the point when the driver bit 12, located directly above the detection recess 36, begins to be lowered. This point will be explained with reference to Figures 12A to 13B.

[0050] Under the control of the robot control unit 21, the driver bit 12 moves in the Y direction by the Y unit 20 after winding up the insert i housed in the hole 4b, and then moves to directly above the detection recess 36 (see the left insert insertion tool 2 shown in Figure 11, Figures 12A and 13A). At this time, the Z-direction positional relationship between the detection recess 36 and the driver bit 12 is set such that, in the normal insert winding state described above, the height of the lower end of the insert i is Hb, with the upper surface of the pallet body 4a where the detection recess 36 is located as the reference point. Note that the height Hb is a design value, and the actual height from the upper surface of the pallet body 4a where the detection recess 36 is located to the lower end of the insert i will vary somewhat from the height Hb due to variations in the dimensions of individual inserts i.

[0051] After the states shown in Figures 12A and 13A, the robot control unit 21 lowers the Z unit 19 at a speed Vb. When lowering the Z unit 19, the rotation of the driver bit 12 is stopped in this embodiment. When the Z unit 19 is lowered, as shown in Figure 13B, the lower end of the insert i contacts the upper surface of the pallet body 4a where the detection recess 36 is provided. As described above, the inner diameter D1 of the detection recess 36 is smaller than the outer diameter D3 of the insert i wound around the driver bit 12. Therefore, even if the Z unit 19 is lowered further after the insert i contacts the upper surface of the pallet body 4a, the insert insertion tool 2 that wound the insert i and the movable plate 34 that holds the insert insertion tool 2 do not move downward. For this reason, the floating base 30 attached to the Z unit 19 moves downward relative to the movable plate 34, as shown in Figure 12C, and the distance between them increases. Consequently, the shielding plate 32 attached to the floating base 30 moves downward relative to the reach sensor 35 attached to the movable plate 34. Here, the robot control unit 21 moves the Z unit 19 until the output state of the electrical signal from the arrival sensor 35 changes (that is, with respect to the distance d1 from the upper end of the shielding plate 32 to the position of the light-emitting and light-receiving parts of the arrival sensor 35, as shown in Figure 12A, until the distance d1 becomes 0, as shown in Figure 12C). At the same time, the judgment unit 21a of the robot control unit 21 measures the time Tb from the moment the Z unit 19 begins to descend at speed Vb until the output state of the electrical signal from the arrival sensor 35 changes. In other words, time Tb is the time it takes for the Z unit 19 to move a distance (Hb+d1) at speed Vb.

[0052] Here, the program / teaching data storage unit 25 stores the information regarding the time Tb described above. Note that the actual height from the top surface of the pallet body 4a to the bottom end of the insert i at the location where the detection recess 36 is provided will vary somewhat from the height Hb set as described above. For this reason, the information regarding the time Tb is set with a range as long as the insertion of the insert i into the workpiece W, which will be described later, is performed normally. Hereinafter, this range of time Tb with a range will be referred to as the second insertable time range. The second insertable time range is stored in the program / teaching data storage unit 25.

[0053] Similar to the insert insertion device 1A described above, this insert insertion device 1B can wind up the insert i housed in the hole 4b with the driver bit 12 using the procedure shown in Figures 5A to 5D. After detecting that the insert i has been wound up correctly using the procedure shown in Figures 12A to 14C, the insert i can be inserted into the workpiece W using the procedure shown in Figures 15A to 15F.

[0054] The robot control unit 21 raises the driver bit 12, which has wound up the insert i, from the hole 4b, and then drives the Y drive motor 24 to move the driver bit 12 directly above the detection recess 36, as shown in Figure 14A. The Z-direction positional relationship between the detection recess 36 and the driver bit 12 at this time is set so that the height of the lower end of the insert i is h4, with reference to the upper surface of the pallet body 4a where the detection recess 36 is provided in the insert normal winding state described above. The height h4 is a height that falls within the range of variation of the height Hb described above. When the robot control unit 21 drives the Z drive motor 23 to lower the Z unit 19 at a speed Vb with the rotation of the driver bit 12 stopped, the determination unit 21a measures the time t4 from when the Z unit 19 starts to descend until the output state of the electrical signal from the arrival sensor 35 changes, and determines whether this time t4 falls within the second insertable time range stored in the program / teaching data storage unit 25. Time t4 is also the time it takes for the Z unit 19 to move a distance (h4 + d1) at a speed Vb. As mentioned above, height h4 is a height that falls within the range of variation in height Hb, and therefore time t4 falls within the second insertable time range. Accordingly, the determination unit 21a determines that the measured time t4 falls within the second insertable time range. Based on the determination by the determination unit 21a, the robot control unit 21 determines that the state shown in Figure 14A allows for the normal insertion of insert i into workpiece W and proceeds with the insertion process of insert i into workpiece W, which will be described later.

[0055] In this embodiment as well, the determination unit 21a can prevent malfunctions that occur in under-winding or over-winding conditions.

[0056] In the underwinding state shown in Figure 14B, the insert i wound by the driver bit 12 is located at a height h5 from the top surface of the pallet body 4a where the detection recess 36 is provided. Note that height h5 is lower than the range of variation at height Hb. When the robot control unit 21 drives the Z drive motor 23 to lower the Z unit 19 at speed Vb, the judgment unit 21a measures the time t5 from when the Z unit 19 begins to descend until the output state of the electrical signal from the arrival sensor 35 changes, and determines whether time t5 falls within the second insertable time range stored in the program / teaching data storage unit 25. Time t5 is the time it takes for the Z unit 19 to move a distance (h5+d1) at speed Vb (t5=(h5+d1) / Vb), and since height h5 is lower than the range of variation at height Hb, time t5 is shorter than the second insertable time range. Therefore, the determination unit 21a determines that the measured time t5 is not included in the second insertable time range. Based on this determination, the robot control unit 21 of this embodiment temporarily suspends operation, determining that the state shown in Figure 14B means that the insert i cannot be inserted into the workpiece W normally. Furthermore, it activates the notification unit 26 to notify the operator that the insert i has not been wound properly onto the driver bit 12.

[0057] Furthermore, in the overwinding state shown in Figure 14C, the insert i wound by the driver bit 12 is located at a height h6 from the upper surface of the pallet body 4a where the detection recess 36 is provided. Note that height h6 is higher than the range of variation at height Hb. When the robot control unit 21 drives the Z drive motor 23 to lower the Z unit 19 at speed Va, the determination unit 21a measures the time t6 from when the Z unit 19 begins to descend until the output state of the electrical signal from the arrival sensor 35 changes, and determines whether time t6 is included in the second insertable time range stored in the program / teaching data storage unit 25. Time t6 is the time (t6=(h6+d1) / Vb) when the Z unit 19 moves a distance (h6+d1) at speed Vb, and since height h6 is higher than the range of variation at height Hb, time t6 is longer than the second insertable time range. Therefore, the determination unit 21a determines that the measured time t6 is not included in the second insertable time range. Based on this determination, the robot control unit 21 of this embodiment temporarily suspends operation, determining that the state shown in Figure 14C does not allow for the normal insertion of the insert i into the workpiece W. Furthermore, it activates the notification unit 26 to notify the operator that the insert i has not been properly wound onto the driver bit 12.

[0058] On the other hand, in the case of the insert in the normal winding state shown in Figure 14A, the robot control unit 21 performs the insert insertion process of the workpiece W shown in Figures 15A to 15F, based on the determination of the determination unit 21a that the measured time t4 falls within the second insertable time range. First, the robot control unit 21 drives the X drive motor 22 and the Y drive motor 24 to move the workpiece W and the insert insertion tool 2, positioning the driver bit 12 directly above the female screw portion of the workpiece W as shown in Figure 15A. Next, the robot control unit 21 drives the Z drive motor 23 to lower the Z unit 19 at a speed Vb. As a result, as shown in Figure 15B, the lower end of the insert i wound on the driver bit 12 comes into contact with the upper end of the female screw portion provided on the workpiece W. As described above, the insert insertion device 1B of this embodiment is equipped with a floating mechanism 5, and since the force with which the insert i presses against the workpiece W is small, damage to the workpiece W due to contact can be prevented.

[0059] The robot control unit 21 further lowers the Z unit 19 at a speed Vb from the state shown in Figure 15B. Here, the insert insertion tool 2 that has wound the insert i, and the movable plate 34 that holds the insert insertion tool 2, do not move downward, so the floating base 30 attached to the Z unit 19 moves downward relative to the movable plate 34, as shown in Figure 15C. The shielding plate 32 attached to the floating base 30 also moves downward relative to the arrival sensor 35 attached to the movable plate 34. In this embodiment, the robot control unit 21 lowers the Z unit 19 until the upper end of the shielding plate 32 is located at a distance d2 lower than the height at which the light-emitting and light-receiving parts of the arrival sensor 35 are located, as shown in Figure 15D. The distance d2 is the depth to which the insert i is inserted into the female screw portion of the workpiece W (the vertical length from the state in Figure 15D where the lower end of the insert i is in contact with the upper end of the female screw portion of the workpiece W, to the state in Figure 15E where the upper end of the insert i is located below the upper surface of the workpiece W).

[0060] In this embodiment, the robot control unit 21 can detect that the Z unit 19 has actually moved to the position shown in Figure 15D using the arrival sensor 35. Specifically, when the Z unit 19 is descending at a speed Vb, the robot control unit 21 starts measuring time t7 from the point when the upper end of the shielding plate 32 shown in Figure 15C becomes lower than the height at which the light-emitting and light-receiving parts of the arrival sensor 35 are located (when the output state of the electrical signal from the arrival sensor 35 changes). Here, the distance that the Z unit 19 moves from the position shown in Figure 15C to the position shown in Figure 15D is the distance d2 mentioned above, and at this time the Z unit 19 is moving at a speed Vb. That is, the robot control unit 21 can detect that the Z unit 19 has actually moved to the position shown in Figure 15D by assuming that time t7 is the value of d2 / Vb.

[0061] When the Z unit 19 moves to the position shown in Figure 15D, the robot control unit 21 stops the Z drive motor 23 and drives the rotary driver motor 10. As a result, the male screw-shaped portion on the outer circumference of the insert i screws into the female screw portion of the workpiece W, and the insert i is pulled into the workpiece W. Consequently, the insert insertion tool 2, the movable plate 34, and the reach sensor 35 move downward along with the insert i.

[0062] As the reach sensor 35 moves downward, and the upper end of the shielding plate 32 reaches the height where the light-emitting and light-receiving parts of the reach sensor 35 are located, as shown in Figure 15E, the output state of the electrical signal from the reach sensor 35 changes. The robot control unit 21 of this embodiment can detect this change in output state. When the output state of the electrical signal from the reach sensor 35 changes, the insert i is positioned below the upper surface of the workpiece W, as shown in Figure 15E. In other words, the robot control unit 21 can detect that the insert i is positioned at the desired depth relative to the workpiece W due to the change in the output state of the electrical signal from the reach sensor 35. Furthermore, when the robot control unit 21 detects the change in the electrical signal from the reach sensor 35, it drives the rotary driver motor 10 so that the driver bit 12 rotates in the reverse direction, and drives the Z drive motor 23 so that the Z unit 19 rises. Due to these actions, the driver bit 12 detaches from the insert i, and the insert i can be inserted into the workpiece W, as shown in Figure 15F.

[0063] As described above, in this embodiment, after the insert i is wound up by the driver bit 12 and before inserting the insert i into the female thread portion of the workpiece W, the determination unit 21a measures the time from when the Z unit 19 begins to descend until the output state of the electrical signal from the arrival sensor 35 changes, based on the electrical signal output from the arrival sensor 35 (corresponding to the "pre-insertion information" in this specification), and determines whether this time is included in the second insertable time range (corresponding to the "predetermined range" in this specification). In other words, if it is determined that the time obtained from the electrical signal from the arrival sensor 35 is not included in the second insertable time range, the process of notifying the operator that an abnormality has occurred without performing the process of inserting the insert i into the workpiece W can be carried out, so that damage to the workpiece W can be prevented even if the above-mentioned under-winding or over-winding conditions occur.

[0064] Furthermore, in the insert insertion device 1B of this embodiment, it is possible to determine whether the insert i has been removed from the driver bit 12 after inserting the insert i into the female thread portion of the workpiece W. This point will be explained below.

[0065] After the process shown in Figure 15F, the robot control unit 21 moves the driver bit 12 directly above the detection recess 36 shown in Figure 14A. As described above, the inner diameter D1 of the detection recess 36 is larger than the outer diameter D2 of the maximum outer diameter part of the male screw-shaped driver bit 12, and smaller than the outer diameter D3 of the insert i wound around the driver bit 12. The determination unit 21a also has a function to determine whether the output state of the electrical signal from the arrival sensor 35 changes when the Z unit 19 is lowered at a predetermined speed for a predetermined time. The "predetermined speed" and "predetermined time" for the Z unit 19 are appropriately selected under the condition that the insert i remains wound around the driver bit 12 without being detached from it, the Z unit 19 is lowered from the position shown in Figure 14A so that the insert i contacts the upper surface of the pallet body 4a, and as a result the shielding plate 32 rises together with the insert insertion tool 2, etc., and is detected by the arrival sensor 35.

[0066] The robot control unit 21 then lowers the Z unit 19 from the position shown in Figure 14A, and the determination unit 21a determines whether or not the output state of the electrical signal from the arrival sensor 35 changes. If the output state of the electrical signal from the arrival sensor 35 does not change, it can be determined that the insert i has been removed from the driver bit 12 and that the insert i has been properly inserted into the workpiece W. On the other hand, if the output state of the electrical signal from the arrival sensor 35 changes, it can be determined that the insert i has not been removed from the driver bit 12, so the robot control unit 21 temporarily stops its operation and activates the notification unit 26 to notify the operator that the insert i remains in the driver bit 12.

[0067] As described above, the determination unit 21a of the insert insertion device 1B of this embodiment determines whether the insert i has been removed from the driver bit 12 using the electrical signal output from the arrival sensor 35 (corresponding to "post-insertion information" in this specification) after inserting the insert i into the female thread portion of the workpiece W. In other words, if it is determined that the insert i has not been removed from the driver bit 12 when determined using the electrical signal from the arrival sensor 35, the operator can be notified that an abnormality has occurred, as described above, thereby preventing problems such as proceeding to the winding of a new insert i while the insert i remains on the driver bit 12.

[0068] The first embodiment of the insert insertion device 1A and the second embodiment of the insert insertion device 1B, which embody the present invention, have been described above, but these embodiments can be modified as appropriate.

[0069] For example, the position sensor 27 of the insert insertion device 1A was provided on the insert supply pallet 4A, and the arrival sensor 35 of the insert insertion device 1B was provided on the insert supply pallet 4B. However, the position sensor 27 and the arrival sensor 35 may be provided in places other than the insert supply pallets 4A and 4B (for example, the robot base 13 or the X table 17).

[0070] Furthermore, both insert insertion devices 1A and 1B change the output state of the electrical signals from the position sensor 27 and the arrival sensor 35 by lowering the driver bit 12, but this is not limited to this. For example, in insert insertion device 1A, an actuator is provided to move the position sensor 27 upward, and the output state of the electrical signal from the position sensor 27 may be changed by raising the position sensor 27 relative to the driver bit 12 using the actuator. In insert insertion device 1B, an actuator is provided to move the insert supply pallet 4B upward, and the output state of the electrical signal from the position sensor 27 may be changed by raising the position sensor 27 relative to the driver bit 12 using the actuator.

[0071] Furthermore, in the insert insertion device 1B of the second embodiment, in order to detect the change in the relative position between the floating base 30 and the movable plate 34 with the arrival sensor 35, a detection recess 36 was provided in the insert supply pallet 4B as shown in Figure 14A, and the insert i wound on the driver bit 12 was brought into contact with the upper surface of the pallet body 4a where the detection recess 36 was provided. However, the detection recess 36 and the upper surface of the pallet body 4a may be the male screw portion of the workpiece W and the upper surface of the workpiece W as shown in Figure 15A, as will be explained below.

[0072] To detect the change in the relative position between the floating base 30 and the movable plate 34 using the male thread portion of the workpiece W and the upper surface of the workpiece W, as shown in Figure 15A, the driver bit 12 with the insert i wound around it is moved directly above the male thread portion of the workpiece W. At this time, the height from the upper surface of the pallet body 4a to the lower end of the insert i is h4. Then, with the rotation of the driver bit 12 stopped, the Z unit 19 is lowered at a speed Vb. Here, since the inner diameter of the male thread portion of the workpiece W is smaller than the outer diameter of the insert i, as the Z unit 19 is lowered, the lower end of the insert i wound around the driver bit 12 comes into contact with the upper surface of the workpiece W, as shown in Figure 15B. As the Z unit 19 continues to be lowered, the shielding plate 32 moves relatively downward with respect to the arrival sensor 35, and the output state of the electrical signal from the arrival sensor 35 changes as shown in Figure 15C. At this time, the determination unit 21a measures the time t4 from when the Z unit 19 begins to descend until the output state of the electrical signal from the arrival sensor 35 changes, and determines whether this time t4 is included in the second insertable time range stored in the program / teaching data storage unit 25. In other words, the method of detecting changes in the relative position between the floating base 30 and the movable plate 34 using the detection recess 36 and the upper surface of the pallet body 4a, as explained with reference to Figures 12A to 13B, can also be used when using the male screw portion of the workpiece W and the upper surface of the workpiece W, as explained with reference to Figures 15A to 15C.

[0073] Furthermore, the detection recess 36 of the insert insertion device 1B is not limited to the one shown in the figure, and is not linked to the movement of the driver bit 12 when the driver bit 12 is lowered (it is immobile), and does not contact the driver bit 12 but contacts the wound insert i. An example of such a device is the insert supply pallet 4C shown in Figures 16A and 16B. The insert supply pallet 4C, like the insert supply pallet 4B described above, has a pallet body 4a and a plurality of holes 4b in which the insert i is accommodated. To the left of the leftmost hole 4b, there is a fixed block 4c and a movable block 4d facing the fixed block 4c. The movable block 4d has an elongated hole that penetrates the movable block 4d vertically and extends horizontally, and a fixing screw 4e for fixing the movable block 4d to the pallet body 4a is inserted into the elongated hole. The fixed block 4c has a through hole that extends horizontally, as shown in Figure 16B, and an adjustment screw 4f is inserted into the through hole. Furthermore, a groove for attaching an E-type retaining ring is provided at the left end of the adjustment screw 4f. By attaching the E-type retaining ring, the adjustment screw 4f is held in place in a rotatable state relative to the fixed block 4c, preventing it from coming loose.

[0074] In the insert supply pallet 4C, the adjustment screw 4f is rotated with the fixing screw 4e loosened to set the gap Gx between the fixed block 4c and the movable block 4d to be larger than the outer diameter D2 of the maximum outer diameter portion of the driver bit 12 shown in Figure 13A, and smaller than the outer diameter D3 of the insert i wound around the driver bit 12. That is, by lowering the driver bit 12 wound around the insert i toward the gap Gx located between the fixed block 4c and the movable block 4d, the lower end of the insert i comes into contact with the upper surfaces of the fixed block 4c and the movable block 4d, thereby changing the relative position between the floating base 30 and the movable plate 34, and this change can be detected by the arrival sensor 35. Since the length of the gap Gx can be changed by the adjustment screw 4f, the insert supply pallet 4C is suitable when using inserts of various sizes in the insert insertion device 1B.

[0075] Furthermore, the insert insertion devices 1A and 1B determine whether the relative position between the insert i and the driver bit 12 is in the correct state by using the time it takes for the output state of the electrical signals from the position sensor 27 and the arrival sensor 35 to change, but the determination regarding the relative position between the two may also be made using other information. A robot 3, such as those provided in the insert insertion devices 1A and 1B, has a robot control unit 21 that knows the amount of movement of the Z unit 19 and the position coordinates of the Z unit 19, so it is possible to detect the relative position between the insert i and the driver bit 12 using this amount of movement and position coordinates. Specifically, when the driver bit 12 is located as shown in Figure 6A, the robot control unit 21 determines the amount of movement of the driver bit 12 from this state until the output state from the position sensor 27 changes after the Z unit 19 is lowered. Here, the program / teaching data storage unit 25 stores a predetermined range of the amount of movement of the driver bit 12 when the insert i is wound in the correct insert winding state relative to the driver bit 12. The determination unit 21a then determines whether the amount of movement of the driver bit 12 until the output state from the position sensor 27 changes is within a predetermined range stored in the program / teaching data storage unit 25. In this way, the amount of movement of the Z unit 19, as grasped by the robot control unit 21, can also be used to determine whether the relative position between the insert i and the driver bit 12 is in a normal state. Alternatively, the position coordinates of the Z unit 19 can be used instead of the amount of movement of the Z unit 19 as described above to determine whether the relative position between the insert i and the driver bit 12 is in a normal state.

[0076] In the above embodiment, a position sensor 27 or a reach sensor 35 was used as a "sensor" to detect the relative position between the insert i wound by the driver bit 12 and the driver bit 12, but other configurations are also possible. For example, in the insert insertion device 1A, the insert i wound by the driver bit 12 may be imaged with a camera, and it may be determined from the image data based on the information output from the camera whether the relative position between the insert i and the driver bit 12 falls within a predetermined range. Alternatively, a contact-type sensor may be used, and the relative position between the insert i and the driver bit 12 may be detected by bringing the insert i wound by the driver bit 12 into contact with the actuator of the sensor. In the insert insertion device 1B, the relative position between the insert i and the driver bit 12 can be detected by the distance between the floating base 30 and the movable plate 34, so the distance between them may be detected with a laser displacement meter or a contact-type sensor, or the gap between the floating base 30 and the movable plate 34 may be imaged with a camera, and the distance between them may be detected from the image data based on the information output from the camera.

[0077] Furthermore, in the insert insertion device 1A of the first embodiment, the operation of the driver bit 12 when changing the output state of the electrical signal from the position sensor 27 was simply to lower the driver bit 12, but it may also be a movement that combines the lowering operation with the horizontal (left-right) movement. For example, when using a small diameter insert i (for example, when the outer diameter of the insert i wound around the driver bit 12 is φ2, and the driver bit 12 has an outer diameter of φ1), the difference between the outer diameter of the insert i and the outer diameter of the driver bit 12 becomes small, so if the driver bit 12 is simply lowered, the position sensor 27 may not be able to detect this difference. In this case, first, the driver bit 12 wound around the insert i is positioned so that the lower end of the insert i is slightly away from the optical axis L of the detection light in the position sensor 27 in the left-right direction and slightly away from the optical axis L, and also slightly away from the optical axis L, and also slightly above. In the following explanation, it is assumed that insert i is wound onto driver bit 12 in the normal winding state, and that the lower end of driver bit 12 is located slightly below the lower end of insert i and at the same height as the optical axis L of the detection light. Under the control of the robot control unit 21, the driver bit 12 is lowered by a predetermined amount, and then moved horizontally toward the position sensor 27 to detect the amount of horizontal movement when the output state of the electrical signal from the position sensor 27 changes. This operation is repeated to detect the amount of horizontal movement when the output state of the electrical signal from the position sensor 27 changes at each height. The program / teaching data storage unit 25 stores the amount of horizontal movement when the output state of the position sensor 27 changes when the above operation is performed with only the driver bit 12. The determination unit 21a checks which of the horizontal movement amounts detected at each height deviates from the horizontal movement amount stored in the program / teaching data storage unit 25, and determines that the height of the driver bit 12 when the horizontal movement amount deviates is the height at which the lower end of insert i is located. The program / teaching data storage unit 25 also stores the height of the driver bit 12 in the under-winding state shown in Figure 6B, and the height of the driver bit 12 in the over-winding state shown in Figure 6C.The determination unit 21a determines that the insert i is wound to the driver bit 12 in the correct winding state if the height of the driver bit 12 determined as described above is higher than a predetermined amount based on the height of the driver bit 12 in the underwinding state stored in the program / teaching data storage unit 25, for example, and lower than a predetermined amount based on the height of the driver bit 12 in the overwinding state. With this configuration, it is possible to confirm whether the insert i is wound to the driver bit 12 in the correct winding state even when the difference between the outer diameter of the insert i and the outer diameter of the driver bit 12 is small.

[0078] Furthermore, in the insert insertion devices 1A and 1B, the driver bit 12 may be interchangeable in order to allow the use of inserts i of various sizes. In the insert insertion device 1A, for example, when the device is started or when the driver bit 12 is replaced, it is possible to check whether the driver bit 12 is the correct one using the position sensor 27. That is, by moving the driver bit 12 horizontally relative to the position sensor 27, the outer diameter of the driver bit 12 can be determined by the difference between the position coordinates of the Y unit 20 grasped by the robot control unit 21 at the start of movement and the position coordinates of the Y unit 20 when the output state from the position sensor 27 changes. In other words, with the insert insertion device 1A, it is possible to check the relative position between the insert i and the driver bit 12 and to check the size of the driver bit 12 using a single position sensor 27.

[0079] (Note) This specification discloses the following technologies in one aspect. The reference numerals listed below correspond to those used in the accompanying drawings, but are provided as examples only and are not intended to limit the inventions of this application.

[0080] (Technology 1) An insert insertion device (1A) comprising a rotating male screw portion (12) and a robot (3) that moves the male screw portion (12), inserts a coil-shaped insert (i) wound by the male screw portion (12) into a female screw portion provided on a workpiece (W), A sensor for detecting the relative position between the insert (i) wound around the male screw portion (12) and the male screw portion (12), An insert insertion device (1A) comprising: a determination unit (21a) that determines whether the relative position is within a predetermined range based on pre-insertion information output from the sensor after the insert (i) has been wound up by the male screw portion (12) and before the insert (i) has been inserted into the female screw portion.

[0081] This technology prevents damage to the workpiece and allows for precise insertion of the insert. If the relative position of the wound insert and the male thread portion is poor, the insert will not be inserted into the workpiece. If the relative position of the two is good, the insert will only be inserted into the workpiece.

[0082] (Technology 2) The insert insertion device (1A) according to Technical Reference 1, wherein the determination unit (21a) makes the determination based on the pre-insertion information output from the sensor when the rotation of the male screw portion (12) has stopped.

[0083] This technology allows for highly accurate detection of the relative position between the insert and the male thread portion using sensors, thus more effectively preventing damage to the workpiece and enabling precise insertion of the insert.

[0084] (Technology 3) The sensor is a position sensor (27) that detects whether or not an object exists at a predetermined position, The insert insertion device (1A) according to Technology 1 or 2, wherein the position sensor (27) detects the relative position between the insert (i) and the male screw portion (12) by moving the male screw portion (12) that has wound the insert (i) relative to the position sensor (27).

[0085] This technology allows for the prevention of workpiece damage, as described above, to be achieved using relatively inexpensive position sensors, thereby reducing the cost of the insert insertion device.

[0086] (Technology 4) The floating mechanism (5) includes a movable part having the male screw portion (12) and a fixed part provided on the robot (3) that movably supports the movable part. The sensor detects changes in the relative position between the fixed part and the movable part. The insert insertion device (1A) according to Technology 1 or 2, wherein the determination unit (21a) makes the determination based on the change in the relative position between the fixed part and the movable part caused by the robot (3) moving the male screw part (12) via the floating mechanism (5) and bringing the tip of the insert (i) into contact with the immovable contact part.

[0087] This technology allows the relative position between the insert and the male thread portion to be detected by sensors used in the floating mechanism, thus reducing the number of sensors required, lowering the cost of the insert insertion device, and simplifying the device's configuration.

[0088] (Technology 5) The insert insertion device (1A) according to claim 1 or 2, wherein the determination unit (21a) determines whether the insert (i) has been removed from the male threaded portion (12) using post-insertion information output from the sensor after the insert (i) has been inserted into the female threaded portion.

[0089] This technology allows for detection even if the insert has not been removed from the male thread section after insertion into the workpiece, thus preventing problems such as proceeding to the winding of a new insert while an insert remains on the male thread section.

[0090] Although one embodiment of the present invention has been described above, the present invention is not limited to such specific embodiments, and unless otherwise specifically limited in the above description, various modifications and changes are possible within the scope of the spirit of the present invention as described in the claims. For example, the configuration of the above-described embodiment can be added or deleted as appropriate, and the configuration of one embodiment can be provided in other embodiments. Furthermore, the effects in the above-described embodiment are merely illustrative of the effects that may result from the present invention. In other words, the effects of the present invention are not limited to the above-described effects, and additional effects may also be produced in addition to the above-described effects. [Explanation of Symbols]

[0091] 1A, 1B: Insert insertion device; 3: Robot; 5: Floating mechanism 12: Driver bit (male screw part) 21a: Judgment unit 27: Position sensor (sensor) 35: Reach Sensor (Sensor) W: Work i: Insert

Claims

1. An insert insertion device comprising a rotating male screw portion and a robot for moving the male screw portion, wherein a coil-shaped insert wound by the male screw portion is inserted into a female screw portion provided on a workpiece, A sensor for detecting the relative position between the insert wound around the male screw portion and the male screw portion, An insert insertion device comprising: a determination unit that determines whether the relative position falls within a predetermined range based on pre-insertion information output from the sensor after the insert has been wound around the male thread portion and before the insert has been inserted into the female thread portion.

2. The insert insertion device according to claim 1, wherein the determination unit makes the determination based on the pre-insertion information output from the sensor when the rotation of the male screw portion has stopped.

3. The sensor is a position sensor that detects whether or not an object exists at a predetermined position, The insert insertion device according to claim 1 or 2, wherein the position sensor detects the relative position between the insert and the male screw portion by moving the male screw portion, which has the insert wound up, relative to the position sensor.

4. The floating mechanism comprises a movable part having the aforementioned male screw portion and a fixed part provided on the robot that movably supports the movable part, The sensor detects changes in the relative position between the fixed part and the movable part. The insert insertion device according to claim 1 or 2, wherein the determination unit makes the determination based on the change in the relative position between the fixed part and the movable part caused by the robot moving the male screw part via the floating mechanism and bringing the tip of the insert into contact with the immovable contact part.

5. The insert insertion device according to claim 1 or 2, wherein the determination unit determines whether the insert has been removed from the male threaded portion using post-insertion information output from the sensor after the insert has been inserted into the female threaded portion.

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