JP2005248973A - Manufacturing device of locking nut - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of requiring preparation for a tool for retooling and also requiring replacement time for the tools when a nut bites a master screw to come into locked state, resulting in stopping of a machine. <P>SOLUTION: In a manufacturing device of a locking nut, on the basis of the image data of a nut W1 acquired by photographing with a camera, the position of a crescent-shaped image W1d, with the start of a thread as an end, is detected to acquire and store a phase angle α1 from a reference line L1 on the basis of the image data of a ring-like elastic plate W2 acquired by photographing with another camera, and a phase angle β1 of an arc-like cut D2 is acquired and stored. A corrective rotational amount β2 of the ring-like elastic plate is acquired based on the phase difference between the stored phase angle data α1 and β1. The ring-like elastic plate W2 is rotated by the corrective rotational amount β2 to correct a phase, the ring-like elastic plate W2 is transported to the nut W1 placed on a prescribed position, and the peripheral wall of counter sink of the nut W1 on which the ring-like elastic plate W2 is placed is assembled by caulking. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a device for manufacturing a locking nut, and more specifically, the bottom surface of a counterbore hole drilled in the end surface of the nut and the ring-shaped elastic plate placed on the bottom surface of the counterbore hole are each photographed by a camera and processed by image processing. The amount of correction is calculated from the phase angle of each obtained image, and after adjusting each phase by one rotation corresponding to this amount of correction, the ring elastic plate is assembled to the bottom of the counterbore of the nut and caulked to prevent loosening The present invention relates to a nut manufacturing apparatus.

  When a non-rotating washer with a plurality of protruding claw pieces provided at equal intervals on the inner end of the nut is assembled by pressing with a press, it is necessary to align it with the predetermined position of the inner peripheral protruding portion of the non-rotating washer. A device relating to a device for detecting the starting position of threading of a nut is disclosed in Japanese Utility Model Publication No. 7-24176.

  According to this publication, according to this publication, a nut having a washer landing end surface for landing a non-rotating washer on the upper surface is provided in a position concentrically with the jig, which supports the nut so as to be movable and pivotable in the axial direction. A master screw having a shoulder surface with which the end face of the nut washer abuts and a reference male screw portion, and being vertically movable, and for screwing the reference male screw portion of the master screw into the nut A diameter changing means, a moving means for moving the master screw to the upper and lower positions, a mechanism for rotating the nut in contact with the jig, and separating the transmission of the rotational force when the washer landing end face comes into contact with the shoulder surface. And a detecting means for detecting the position at which the washer landing end surface of the nut is in contact with the shoulder surface of the master screw and outputting the detected position to the driving means. And the circumferential position is detected as threaded beginning of the nut.

  As shown in FIG. 7, the nut N is fitted on the working jig 3, and the predetermined number of threads of the half master screws 16, 16 closed so as to reduce the screw diameter of the reference male screw is engaged with the female screw of the nut N. Then, the master screws 16 and 16 are opened by the diameter changing means 14, and the threads of the master screws 16 and 16 are screwed onto the female screw of the nut N. When the nut N is rotated by a driving means (not shown), the nut N rotates and rises, and the washer landing end surface Na comes into contact with the shoulder surfaces 16a of the master screws 16 and 16. When the nut N comes into contact, the load on the driving means increases, the drive contact portion slips, and the rotation of the nut N stops. The master screws 16, 16 are closed and extracted. Since the shoulder surface 16a and the reference male screw parts 16 and 16 are formed so that the screw N start position of the nut N is at a predetermined angular position with respect to the contact stop position of the nut N, the nut N is stopped at the stop position. The predetermined angular position can be detected as the screw cutting start position.

  However, in the idea of the real fair 7-24176, the nut N is fitted to the working jig 3, and the predetermined number of threads of the master screws 16 and 16 closed so as to reduce the screw diameter of the reference male screw is the female screw of the nut N. Then, the master screws 16 and 16 are opened, the threads of the master screws 16 and 16 are screwed into the female threads of the nut N, and the nut N is rotated by rotating the nut N with the driving means. At this time, if the crests and troughs of the master screws 16 and 16 and the nut N do not mesh well, even if the nut N is rotated, the screw bites into the locked state. There is a problem that the machine may stop, and this repair takes time and productivity is lowered. In addition, there are several types of locking nuts, but there is a problem that several types of tools need to be prepared, and there is a problem that setup change time is required to change the tool every time the size changes. . Further, each time the nut N starts to be cut, the master screws 16, 16 are screwed into the nut N, and the male screw surfaces of the master screws 16, 16 are rubbed by the nut N each time, and wear gradually occurs. Therefore, there has been a problem that it is necessary to replace the tool regularly. In addition, since this device operates such that the nut N is screwed into the master screws 16 and 16 every time the nut N threading start position is detected, the time is inevitably required, and it is difficult to shorten the cycle time. It was.

  As described above, the idea of the real fair 7-24176 is that the nut and the master screw bite into a locked state and the machine is stopped, there is a need to prepare a plurality of tools for changing the setup, and the machine It is difficult to shorten the cycle time because it takes time to return to the stop, the time to change the tool when changing the setup, and the time to periodically replace the worn tool. There was a problem.

  Further, although not an invention relating to a device for manufacturing a locking nut, as disclosed in Japanese Patent Laid-Open No. 9-64598, in FIG. 8, at least two or more measurement portions of each of the assembly 10 and the assembly component 11 are shown. The positions of the assembled body 10 and the assembled part 11 are detected to determine the amount of displacement of the assembled part 11 with respect to the assembled position of the assembled body 10 based on the detected results of these attitudes. Then, the XYZ-θ robot 2 moves the position of the assembly component 11 in accordance with the obtained deviation amount, and determines the relative positional relationship between the assembly 10 and the assembly component 11. However, there is an automatic assembly apparatus alignment method that can accurately assemble the assembly component 11 at the assembly position of the assembly 10.

  According to the present invention, the positions of at least two measurement portions of each of the assembly 10 and the assembly component 11 are measured by the television cameras 6 and 7 to detect the postures of the assembly 10 and the assembly component 11, and Based on the detection results of the postures of the assembled body 10 and the assembled part 11, the amount of displacement of the assembled part 11 with respect to the assembled position of the assembled body 10 is obtained, and the assembled part 11 is moved according to the amount of displacement to be assembled. It is characterized by being assembled at 10 assembling positions.

  However, the invention disclosed in Japanese Patent Application Laid-Open No. 9-64598 detects the position of the screw cutting start position from the end face image of the nut photographed by the television camera, obtains the phase angle from the reference, and determines the screw cutting start position. There is no description and no suggestion about what is required. That is, according to the present invention, the position of the crescent-shaped image that appears from the end face image of the nut as an end is detected from the end face image of the nut, the phase angle from the reference line is obtained, and the end face photographed separately by the TV camera is obtained on this nut. There is no description or suggestion regarding the assembly of the ring-shaped elastic plate whose phase angle is obtained from the image so that these phases are matched.

No. 7-24176 Japanese Patent Laid-Open No. 9-64598

  The problem to be solved by the present invention is that a ring-shaped elastic plate having an arc-shaped notch formed on the inner periphery is positioned and placed on the bottom surface of a counterbore hole drilled concentrically with the screw hole from the end face of the nut. In a manufacturing device for a locking nut that attaches the ring-shaped elastic plate in close contact with the bottom surface of the counterbored hole by caulking the peripheral wall of the counterbore hole, the nut and the master screw bite into the locked state The problem of stopping, the need to prepare multiple tools for setup change, as well as the time required to return to machine stop, the time for changing tools at the time of setup change, and the time for periodically changing worn tools It solves the problem that it is necessary and the problem that it is difficult to shorten the cycle time because it takes a screwing time of the nut to detect the position.

  The present invention according to claim 1, after positioning and mounting a ring-shaped elastic plate in which an arc-shaped notch is formed in the inner peripheral portion on the bottom surface of the counterbore hole drilled concentrically with the screw hole from the end surface of the nut, A device for manufacturing a locking nut that attaches the ring-shaped elastic plate in close contact with the bottom surface of the counterbored hole by caulking the peripheral wall of the counterbore hole, and is provided facing the bottom surface of the counterbored hole of the nut. A first photographing means for obtaining image data by photographing the bottom face of the counterbored hole with a camera; and detecting a position of an image of a thread slope that appears as a crescent shape from the image data of the bottom face of the counterbored hole as an end. The ring-shaped elastic plate end surface by a first image processing means for obtaining and storing a phase angle from a reference line in a predetermined direction passing through the center of the nut, and a camera provided facing the end surface of the ring-shaped elastic plate A second photographing means for obtaining image data by photographing, and detecting a position of the arc-shaped notch from the image data of the end surface of the ring-shaped elastic plate and determining a phase angle from a reference line in a predetermined direction passing through the center of the ring-shaped elastic plate; From the second image processing means to be obtained and stored, the phase angle data from the crescent-shaped image reference line obtained by the first image processing means and the arc-shaped notch reference line obtained by the second image processing means Based on the difference from the phase angle data, a calculation unit for obtaining a corrected rotation amount for matching the phase from the reference line of the nut with the phase from the reference line of the ring-shaped elastic plate, A rotating means for correcting the phase by rotating any one of the ring-shaped elastic plates; a transferring means for transferring and placing the ring-shaped elastic plates in a counterbore of the nut placed at a predetermined position; ring Elastic plate is the most important feature that is composed of a crimping means for assembling the caulking the ring-like elastic plates counterbore wall of the placed the nut on the inside and closely fixed to the counterbore bottom.

  According to a second aspect of the present invention, in the locking nut manufacturing apparatus according to the first aspect, a main line provided with a plurality of steps in which the supplied nuts are sequentially conveyed, and the supplied ring The sub-line is provided with a plurality of steps in which the elastic plate is sequentially conveyed, and the sub-line is provided with a step of photographing the end surface of the ring-shaped elastic plate that has been conveyed and positioned by the camera with the second photographing means. The main line includes a step of photographing the bottom face of the counterbored hole of the nut positioned and conveyed by the camera with the first photographing means, and a step of the counterbored hole of the nut conveyed to the predetermined position from this step. The ring-shaped elastic plate whose end face is photographed by the second photographing means in the sub-line is rotated by the correction means by the rotating means. A step of being transferred and placed by the transferring means, and a ring-shaped elastic member that is further caulked by the caulking means on the peripheral wall of the nut that is further transported from this step and on which the ring-like elastic plate is placed. And a step of assembling the plate in close contact with the bottom surface of the counterbore hole.

  According to a third aspect of the present invention, in the locking nut manufacturing apparatus according to the first or second aspect, the position of the image of the thread slope appearing as the crescent shape is obtained by the first image processing means. The most important feature is the center of gravity of the crescent-shaped image.

  According to a fourth aspect of the present invention, in the locking nut manufacturing apparatus according to the first or second aspect, the position of the image of the thread slope that appears as the crescent shape is obtained by the first image processing means. The most important feature is the position where the radial width of the crescent-shaped image is maximum.

  According to a first aspect of the present invention, there is provided the locking nut manufacturing apparatus according to the first image processing means, starting from the start of threading, from the image data of the bottom face of the counterbore of the nut obtained by photographing with the camera of the first photographing means. The position of the crescent-shaped image is detected, the phase angle from the reference line is obtained and stored, and from the image data of the end face of the ring-shaped elastic plate obtained by photographing with the camera of the second photographing means, the second image processing means The position of the arc-shaped notch is detected and the phase angle from the reference line is obtained and stored. Based on the phase difference between the stored phase angle data of the crescent-shaped image and the phase angle data of the arc-shaped notch, the nut The correction rotation amount that matches the phase from the reference line of the ring and the phase from the reference line of the ring-shaped elastic plate is obtained, and the rotating means rotates either the nut or the ring-shaped elastic plate by this correction rotation amount. Correct the phase, transfer the ring-shaped elastic plate to the counterbore of the nut placed at a predetermined position by the transfer means, and place the ring-shaped elastic plate around the counterbore of the nut on which the ring-shaped elastic plate is mounted by the caulking means The ring-shaped elastic plate was caulked inward and fixed to the bottom face of the counterbore and assembled.

  As a result, it is possible to determine the difference between the phase angles of the ring-shaped elastic plate while detecting the position direction of the crescent-shaped image with the start of threading as the end, and the position direction of the ring-shaped elastic plate, without contact. The arc-shaped notch position or arc-shaped protrusion position of the ring-shaped elastic plate can be positioned at a predetermined position and combined with the nut threading start position, and these detections and calculations can be performed instantaneously. Therefore, the time required for detection and calculation is shortened, and positioning with a short cycle time is possible. In addition, if there is no need for a tool and image processing means corresponding to each of the multiple locking nuts is prepared, the screws will bite into a locked state and the machine will not stop, and there will be multiple setup replacements. There is an advantage that it is possible to manufacture a locking nut without the necessity of preparing the tool of the present invention and without the need to change the tool when changing the setup. As a result, the machine stop time is reduced, and the cycle time is shortened, so that the productivity is increased.

  According to a second aspect of the present invention, there is provided the locking nut manufacturing apparatus according to the first aspect, wherein the first locking means is used to sequentially photograph the bottom face of the counterbored hole by the camera and the subline. And a step in which the ring-shaped elastic plate whose end face is photographed by the camera in the second photographing means is rotated by the rotating means by the correction rotation amount and then transferred and placed on the bottom face of the counterbored hole of the nut by the conveying means, and the nut by the caulking means The process of caulking the peripheral wall of the counterbore hole and assembling the ring-shaped elastic plate on the bottom surface of the counterbore hole is continuously provided on the main line, so each automatically supplied nut and ring-shaped elastic plate can be photographed. After being performed at the same time, the nut is transported to a predetermined position, and the ring-shaped elastic plate is rotated by the corrective rotation amount, and then from the subline to the main line Transported positioned on the positional nut, then there is an advantage that the ring-shaped elastic plate can be carried out automatically and continuously the series of operations to be assembled Shimete or the counterbore bottom surface of the nut.

  According to a third aspect of the present invention, there is provided the locking nut manufacturing apparatus according to the first or second aspect, wherein the crescent-shaped image centroid position obtained by the first image processing means is calculated as a crescent-shaped image. Since the position is set, there is an advantage that the position of the crescent moon shape can be accurately obtained, and further, the screw cutting start position can be accurately obtained with reference to this position.

  The locking nut manufacturing apparatus according to claim 4 is the locking nut manufacturing apparatus according to claim 1 or 2, wherein the crescent-shaped image obtained by the first image processing means has a maximum radial width. Therefore, there is an advantage that the position of the crescent moon can be accurately obtained, and further, the screw cutting start position can be accurately obtained with reference to this position.

  The problem that the nut and master screw bite into a locked state and the machine stops, the problem that it is necessary to prepare multiple tools for setup change, the time required to return to the machine stop, the tool required at the time of setup change In order to solve the problem that the replacement time and the periodic replacement time of the worn tool are necessary, and the problem that the screwing time of the nut is required for position detection and it is difficult to shorten the cycle time, the image is taken with a camera. A ring-shaped elastic plate obtained by detecting the position of a crescent-shaped image whose end is the start of thread cutting from the obtained end face image data of the nut, obtaining the phase angle from the reference line, storing it, and photographing it with another camera The phase angle of the arc-shaped notch is obtained and stored from the end face image data, and the corrected rotation amount of the ring-shaped elastic plate based on the phase difference of each stored phase angle data The phase is corrected by rotating the ring-shaped elastic plate by this corrected rotation amount, the ring-shaped elastic plate is transferred and placed on the upper surface of the nut placed at a predetermined position, and the nut on which the ring-shaped elastic plate is placed The peripheral wall of the counterbore hole was caulked and assembled.

  FIG. 1 is a plan view schematically showing the apparatus of the present invention. (Hereinafter, in the description of the drawings related to the present invention, there are some overlapping with the description numbers of the above-mentioned prior art figures, but the following numbers are used only for the present invention.) Includes an 8-index rotary table 2 that sequentially positions and conveys a nut W1 of a part to be assembled between processes of a main line composed of a plurality of processes, and a ring-shaped assembly part in each process of a subline composed of a plurality of processes. A four-index rotary table 3 for sequentially positioning and conveying the elastic plate W2, a three-axis robot 4 for transferring and placing a sub-line ring-shaped elastic plate W2 on a nut W1 at a predetermined position on the main line, a main line, A plurality of units for each process constituting each subline are arranged. The turntable 2 and the turntable 3 are disposed adjacent to each other, and the periphery of the turntable 2 is supplied with a nut W1 from a not-shown parts feeder, step 1 shown by 11, and step 12 indicated by an inspection of the nut W1. 2. Step 3 shown in 13 in which image data is obtained by photographing the nut W1 with the camera of the first photographing means. The sub-line ring-shaped elastic plate W2 is transferred by the three-axis robot 4 and placed on the counterbore surface of the nut W1. 14, step 4 shown by idle 14, step 5 shown by 15 for attaching the ring-shaped elastic plate W 2 to the nut W 1 by caulking, step 7 shown by 16 for inspecting the assembly, and step 17 for taking out the assembly. Eight units are arranged radially.

  Further, in the periphery of the turntable 3, a ring-shaped elastic plate W2 is supplied from a part feeder (not shown), step 1 shown by 18, a step 2 shown by idle 19 and the ring-shaped elastic plate W2 as a camera of the second photographing means. Step 3 indicated by 20 in which image data is obtained by photographing, and Step 4 indicated by 21 in which the ring-shaped elastic plate W2 is gripped by the three-axis robot 4 and transferred to the main line are arranged radially. Between the rotary table 3 and the rotary table 2, the ring-shaped elastic plate W2 is gripped and transferred from the step 4 of the rotary table 3 to the step 4 of the rotary table 2, and the orientation direction of the gripped ring-shaped elastic plate W2, ie, A triaxial robot 4 to which a rotating means for changing the phase is attached is arranged.

  Jigs 31 are attached to the outer edge of the rotary table 2 at positions equally divided into eight on the same circumference, and a screw hole of a nut W1 is fitted on the upper surface of the jig 31 as shown in FIG. A shaft portion 31a having an outer diameter capable of positioning the nut N1 protrudes. The shaft portion 31a is provided with one key groove-shaped notch portion (not shown) on the outer periphery, and a leaf spring (not shown) presses a nut W1 fitted to the shaft portion 31a to the key groove-shaped notch portion. And the brake is applied so that the nut W1 does not rotate. In addition, jigs 41 are attached to the outer edge of the rotary table 3 at positions equally divided into four on the same circumference, and on the upper surface of the jig 41, as shown in FIG. A hole having an inner diameter capable of positioning the ring-shaped elastic plate W2 by fitting the outer periphery and a hole having an inner diameter slightly smaller than the hole are formed in a stepped manner, and the stepped portion of these holes is formed in the ring-shaped elastic plate W2. It is flat so that it can be supported stably.

  FIG. 2 is a side view showing the first photographing means in the main line process 3. As the rotary table 2 is indexed and rotated, a screw hole is fitted into the shaft portion 31a of the jig 31, is pressed and held by a leaf spring, is placed and positioned in close contact with the upper surface of the jig 31, and is conveyed from step 2. The nut W1 is annularly irradiated from the upper outer peripheral direction by the light source 33, and is photographed from above by the camera 32 installed above the light source and directly above the nut W1. The nut W1 is formed with a counterbore of a predetermined depth from the surface on the upper surface side, and is focused on this counterbore surface.

  The end face image data of the nut W1 photographed by the camera of the first photographing means is subjected to image processing by a first image processing means provided in a control unit (not shown). The first image processing means includes a preprocessing function for binarizing image data, an analysis processing function for analyzing the binarized data, a calculation function for numerically calculating and correcting a position of the analysis processing result according to a program, And a storage function for storing image data and calculation results. The binarized image data and the analysis result are displayed on the monitor.

  This image processing will be described with reference to FIG. As shown in FIG. 5A, the binarized image of the nut W1 includes an outer peripheral hexagonal portion W1a and a white annular image portion of a counterbore peripheral wall where a predetermined amount of the wall rises in a cylindrical shape immediately inside the outer peripheral hexagonal portion W1a. W1b, a black planar image portion W1c showing a processing surface that is processed at a predetermined depth inside thereof and is perpendicular to the screw hole, and a black circular image portion W1e showing an innermost through screw hole, Then, a white crescent-shaped image portion W1d at an eccentric position with the start of screw cutting as an end, in which a spirally cut thread slope between the flat image portion W1c and the circular image portion W1e is projected. It consists of and.

  Next, similarly, the first image processing means obtains the annular center based on the annular image portion W1b, and this center is regarded as the center position O1 of the nut W1. Next, the center-of-gravity position P1 of the crescent moon-shaped image portion W1d with the start of threading as an end is obtained. A line that passes through the center position O1 of the nut W1 and the center of gravity position P1 of the crescent-shaped image portion W1d is determined with respect to a reference line L1 that passes through the center position O1 of the nut W1 and is set in the center direction of the rotary table 2. Or its phase angle α1 is measured and stored as phase angle data α1. Here, it is known that the gravity center position P1 of the crescent-shaped image portion W1d can be expressed using, for example, the moment of inertia when the image density or luminance is considered as mass, and is obtained as follows. Considering XY coordinates including the crescent-shaped image portion W1d and having the center position O1 of the nut W1 as the origin, the coordinates (x, y) of the position P1 of the center of gravity are represented by x = My / S and y = Mx / S. . Here, My is the primary moment of inertia with respect to the y-axis of the crescent-shaped image portion W1d, Mx is the primary moment of inertia with respect to the x-axis of the crescent-shaped image portion W1d, and S is the area of the crescent-shaped image portion W1d. Mx and My sequentially add the coordinate values of the X and Y coordinates of the effective pixels in the measurement target window, and S can be obtained as the sum of the effective pixels.

  FIG. 3 is a side view showing the second photographing means in the subline process 3. Along with the indexing rotation of the turntable 3, the ring-shaped elastic plate W2 positioned by the jig 41 and conveyed from the step 2 is irradiated from directly below by the light source 43, and from directly above by the camera 42 installed immediately above it. Taken. As a result, the inner edge hole portion of the ring-shaped elastic plate W2 is projected as a white silhouette by the transmitted light.

  The end face image data of the ring-shaped elastic plate W2 photographed by the camera of the second photographing means is subjected to image processing by a second image processing means provided in a control unit (not shown). The second image processing means includes a preprocessing function for binarizing the image data, an analysis processing function for analyzing the binarized data, a calculation function for numerically calculating and correcting the position of the analysis processing result according to a program, And a storage function for storing image data and calculation results. The binarized image data and the analysis result are displayed on the same monitor that displays the image data and the analysis result of the nut W1, and can be switched arbitrarily.

  This image processing will be described with reference to FIG. The end face image data of the ring-shaped elastic plate W2 photographed by the camera of the second photographing means is binarized by the second image processing means, and the binarized image of the end face of the ring-shaped elastic plate W2 is shown in FIG. As shown in (b), the light is irradiated from the light source 43 from below, and is composed of a silhouette image portion W2b of the inner edge hole portion that appears white and a black shadow image portion W2a of the outer edge.

  Next, the center of the outer circumferential arc is obtained by the second image processing means based on the arc-shaped notched outer circumferential arcs D2 and D2 of the ring-shaped elastic plate W2, and this center is the center position O2 of the ring-shaped elastic plate W2. Is regarded as Next, the center position P2 on the arc-shaped notch outer peripheral arc D2 is obtained. A line passing through the center position O2 of the ring-shaped elastic plate W2 and the center position P2 on the arc-shaped cutout outer peripheral arc D2 is set in the center direction of the turntable 3 through the center position O2 of the ring-shaped elastic plate W2. The phase angle β1 of the angle relative to the reference line L2 is measured and stored as phase angle data β1.

  Next, in a calculation unit provided in a control unit (not shown), phase angle data α1 from the reference line of the center of gravity position P1 of the crescent moon shaped image portion W1d obtained by the first image processing unit and the second image processing unit A difference (α1−β1) from the phase angle data β1 from the reference line of the center position P2 on the obtained arcuate cutout outer peripheral arc D2 is obtained, and based on this difference (α1−β1), a difference from the predetermined phase angle θ is obtained. The difference, corrected rotation amount β2 = ((α1−β1) ± θ) is obtained. Here, for the phase angles α1 and β1, the counterclockwise direction with respect to the reference lines L1 and L2 is +, and the clockwise direction is −. In this embodiment, θ = 45 °. If the smaller absolute value is selected, the correction rotation time can be shortened. Further, the value of θ may be appropriately changed in accordance with the characteristics after the loosening nut is assembled.

  In this way, the nut W1 and the ring-shaped elastic plate W2 photographed in the main line process 3 and the subline process 3 are respectively transferred to the next process, and the nut W1 is positioned at a predetermined position in the main line process 4, while the ring W From the subline process 4, the cylindrical elastic plate W2 is adsorbed and held by the vacuum chuck 51 attached to the tip of the rotation R axis of the X axis, Y axis and R axis triaxial robot 4 shown in FIG. (Y-axis direction) The cylinder 57 for driving and the driving cylinder 58 in the left-right direction (X-axis direction) are transferred and mounted on the counterbore surface of the nut W1 positioned at a predetermined position in the main line process 4. During this transfer, the rotation R axis is rotated by the servo motor 56 through the speed reduction means 55 by the angle of the corrected rotation amount β2 obtained by the calculation unit. As a result, when placed on the nut W1, as shown in FIG. 5 (c), the center position P2 on the arc-shaped notch of the ring-shaped elastic plate W2 is the center of gravity of the crescent-shaped image portion W1d of the nut W1. The phase difference is adjusted to the predetermined phase angle θ with respect to the position P1.

  Next, the nut W1 and the ring-shaped elastic plate W2 positioned and mounted on the counterbore surface are transported and positioned in the caulking process 6 after passing through the idle process 5 of the main line. In this caulking step 6, as shown in FIG. 1, a caulking unit 61 is installed that caulks the counterbore peripheral wall of the nut W1 inward by lowering of the caulking tool attached to the lower surface of the ram that moves up and down by hydraulic pressure. . When the nut W1 and the ring-shaped elastic plate W2 positioned and placed in phase with the counterbore surface are conveyed and positioned in this process, the ram is lowered and the counterbore peripheral wall of the nut W1 is caulked inward. The ring-shaped elastic plate W2 is assembled in close contact with the bottom surface of the counterbore hole. As a result, the assembly of the locking nut is completed, in which the arc-shaped notch position of the ring-shaped elastic plate is positioned at a predetermined position with respect to the screw start position of the nut W1. That is, the arcuate protrusion position is also positioned at a predetermined position with respect to the threading start position of the nut W1. When this assembling is completed, it is transported to the next process, and the caulking inspection is performed in the process 7 shown in 16 for inspecting the assembly, and further transported to the next process and the process in the process 8 shown in 17 for taking out the assembly. Based on the inspection result in 7, the product is sorted into non-defective product and defective product and discharged.

  Here, the positional relationship between the gravity center position P1 of the crescent-shaped image of the nut W1 and the screw start position will be described. In the case of a female thread of a metric thread defined by the thread standard, for example, the JIS standard, the apex portion of the screw thread is actually a flat surface instead of the apex. According to the JIS standard, in the case of M8 screws, the length of the plane portion is 1/4 of the screw pitch. Therefore, when the cross section is perpendicular to the screw hole, the thread slope part that sinks spirally from the cut surface is essentially a crescent-shaped ring with no cuts on the entire circumference. A crescent-shaped image having a cut portion at a part of the crescent ring according to the length ratio (1/4) of the plane and having the start of screw cutting as an end appears. The angle of the cut portion is 1/4 of the entire circumference, that is, 90 °, which is the same as the length ratio of the flat surface of the thread apex portion. The position of the center of gravity of the crescent-shaped image, that is, the position having the largest width is the valley portion of the screw, and the cut portion on the opposite side to 180 ° is the apex portion of the screw thread. That is, the angle from the center of gravity P1 of the crescent-shaped image to the screw start position is 135 °. Therefore, if the center of gravity P1 of the crescent-shaped image, that is, the position P1 ′ having the largest crescent-shaped width can be detected, the position is the bottom of the screw, and the position of the arc-shaped protrusion of the ring-shaped elastic plate W2 is determined with respect to it. The position can be determined, and the angle can be determined based on the gravity center position P1. Then, when the male thread is screwed into this locking nut by positioning the arc-shaped notch or the arc-shaped protrusion of the ring-shaped elastic plate W2 at a predetermined position and assembling it, as shown in FIG. The thread of the male screw smoothly transfers to the ring-shaped elastic plate W2 to bend the arc-shaped protrusion of the ring-shaped elastic plate W2, and the surface pressure can apply a frictional force to the threaded slope of the male screw. . In this way, the nut can be prevented from rotating.

  In Example 2, the center of gravity position P1 of the crescent moon-shaped image portion W1d in Example 1 is at an angle with respect to the reference line L1 set in the center direction of the rotary table 2 through the center position O1 of the nut W1. There is only a difference in the method for obtaining the phase angle, and the others are the same as those in the first embodiment. Therefore, only the method for obtaining the phase angle will be described.

  Image data of the nut W1 photographed by the camera of the first photographing means is subjected to image processing by the first image processing means. As shown in FIG. 5A, the image of the nut W1 binarized by the first image processing means is a counterbore with an outer peripheral hexagonal portion W1a and a cylindrical wall immediately inside the outer peripheral hexagonal portion W1a. A white annular image portion W1b of the peripheral wall of the hole, a black planar image portion W1c showing a processing surface which is processed at a predetermined depth inside thereof and is perpendicular to the screw hole, and an innermost through screw hole are shown. An eccentric position with the start of threading as an end, in which the threaded slope of the spiral cut is projected between the black circular image portion W1e and the flat image portion W1c and the circular image portion W1e. And a white crescent-shaped image portion W1d.

  First, the first image processing means obtains the annular center based on the annular image portion W1b, and this center is regarded as the center position O1 of the nut W1. Next, the image is rotated about O1 by a predetermined rotation angle γ °, the width of the crescent moon-shaped image portion W1d on the reference line L1 is measured, and the width and the number of rotations n by γ ° are stored. Then, the position where the measured width value is maximum is obtained as the position P1 'of the maximum width portion of the crescent moon-shaped image portion W1d. The line passing through the center position O1 of the nut W1 and the maximum width position P1 ′ of the crescent-shaped image portion W1d passes through the center position O1 of the nut W1 with respect to the reference line L1 set in the center direction of the turntable 2. Or the phase angle α1 is obtained as the product of the rotation angle γ and the number of rotations n and stored as phase angle data α1. After that, similarly to the first embodiment, the correction rotation is performed with the phase angle β1 with respect to the reference line L2 set in the center direction of the turntable 3 through the center position O2 of the ring-shaped elastic plate W2 obtained and stored in the sub-line. The quantity β2 is determined. The rest is the same as in the first embodiment, and is omitted.

  Since it did in this way, while the manufacturing apparatus of the locking nut W1 of this invention is non-contact, it detects the position direction of the crescent moon shape which appears with the start of threading as an end, and the position direction of the ring-shaped elastic board W2, The difference between the phase angles can be obtained, and the arcuate notch position or the arcuate protrusion position of the ring-shaped elastic plate W2 is positioned at a predetermined position with respect to the screw cutting start position of the nut W1. Can be combined. Further, since these detection and calculation can be performed instantaneously, the time required for detection and calculation is shortened, and positioning with a short cycle time is possible. In addition, if there is no need for a tool and image processing means corresponding to each of the multiple locking nuts is prepared, the screws will bite into a locked state and the machine will not stop, and there will be multiple setup replacements. There is no need to prepare the tool, and there is no need to change the tool when changing the setup.

  The automatically supplied nut W1 and ring-shaped elastic plate W2 are simultaneously photographed, then the nut W1 is conveyed to a predetermined position, and the ring-shaped elastic plate W2 is rotated by the correction rotation amount β2. The series of operations in which the ring-shaped elastic plate W2 is caulked and assembled to the bottom surface of the counterbore of the nut W1 can be performed automatically and continuously. There is an effect. In the first embodiment, the position of the crescent-shaped image can be accurately obtained as the center of gravity position, and the screw cutting start position can be accurately obtained with reference to this position.

  Further, in the second embodiment, the position where the radial width of the crescent-shaped image obtained by the first image processing unit is the maximum is set as the position of the crescent-shaped image, so that the position of the crescent-shaped image is accurately obtained. In addition, there is an effect that the screw cutting start position can be accurately obtained with reference to this position.

  In the present invention, the end face of the nut is photographed, and the position direction of the crescent shape starting from the start of threading is detected from the image shape to determine the start of threading. The present invention can also be applied to detecting the start of screw cutting from a photographed image shape.

It is a top view which shows the outline of the apparatus of this invention. It is a side view which shows a 1st imaging | photography means. It is a side view which shows a 2nd imaging | photography means. It is a front view which shows a transfer means. (A) is a nut W1, (b) is a ring-shaped elastic board W2, (c) is a top view of the state which crimped and assembled the ring-shaped elastic board W2 to the nut W1. It is side surface sectional drawing which shows the effect | action of a locking nut. 1 is a side cross-sectional view of a prior art device. 1 is a perspective view of a prior art device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 2 Rotary table 3 Rotary table 4 3-axis robot 31 Jig 32 Camera 41 Jig 42 Camera 51 Vacuum chuck 56 Servo motor 57 Vertical drive cylinder 58 Horizontal drive cylinder W1 Nut W2 Ring-shaped elastic board

Claims (4)

A ring-shaped elastic plate with an arc-shaped notch formed on the inner periphery is positioned and placed on the bottom surface of the counterbore hole drilled concentrically with the screw hole from the end face of the nut, and then the peripheral wall of the counterbore hole is caulked inward. A device for producing a locking nut that attaches the ring-shaped elastic plate to the bottom face of the counterbore in close contact with each other,
First photographing means for obtaining image data by photographing the bottom face of the counterbore hole by a camera provided facing the bottom face of the counterbore hole of the nut;
A first image for detecting and storing a phase angle from a reference line in a predetermined direction passing through the nut center by detecting the position of an image of a thread slope that appears as a crescent shape from the image data of the bottom face of the counterbore hole. Processing means;
Second imaging means for obtaining image data by imaging the end surface of the ring-shaped elastic plate with a camera provided opposite to the end surface of the ring-shaped elastic plate;
Second image processing means for detecting the position of the arc-shaped notch from the image data of the end surface of the ring-shaped elastic plate and determining and storing a phase angle from a reference line in a predetermined direction passing through the center of the ring-shaped elastic plate;
Based on the difference between the phase angle data from the reference line of the crescent moon shape image obtained by the first image processing means and the phase angle data from the reference line of the arc-shaped notch obtained by the second image processing means, A calculation unit for obtaining a correction rotation amount for matching the phase from the reference line of the nut and the phase from the reference line of the ring-shaped elastic plate;
Rotating means for correcting the phase by rotating either the nut or the ring-shaped elastic plate by this correction rotation amount;
Transfer means for transferring and placing the ring-shaped elastic plate in a counterbore of the nut placed at a predetermined position;
A caulking means for caulking the counterbore hole peripheral wall of the nut on which the ring-shaped elastic plate is placed inward and fixing the ring-shaped elastic plate to the bottom surface of the counterbore, and assembling;
An apparatus for producing a locking nut, comprising:   The main line is provided with a plurality of steps in which the supplied nuts are sequentially conveyed, and the subline is provided with a plurality of steps in which the supplied ring-shaped elastic plates are sequentially conveyed. Includes a step of photographing the end surface of the ring-shaped elastic plate that has been transported and positioned by the camera with the second photographing unit, and the main line includes the bottom surface of the counterbored hole of the nut that has been transported and positioned in the first photographing. A step of photographing with a camera by means, and the ring-shaped elastic plate whose end face is photographed by the camera with the second photographing means in the sub-line in the counterbore of the nut transferred to the predetermined position from this step. A step of being transferred and placed by the transfer means while being rotated by a correction rotation amount by the rotation means; A step of caulking the counterbore hole peripheral wall of the nut on which the ring-shaped elastic plate is placed inwardly by the caulking means, and fixing the ring-shaped elastic plate to the bottom surface of the counterbore and assembling the nut. 2. A device for manufacturing a locking nut according to claim 1, wherein   The position of the image of the thread slope that appears as the crescent shape is the position of the center of gravity of the crescent-shaped image obtained by the first image processing means, The locking nut according to claim 1 or 2, manufacturing device.   The position of the image of the thread slope that appears as the crescent shape is a position where the radial width of the crescent-shaped image obtained by the first image processing means is maximized. A device for producing a locking nut according to claim 1.

Images