JP3280569B2 - Method of setting processing order in bolt nut automatic attachment / detachment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for automatically attaching / detaching a bolt / nut to / from a bolt / nut fastener.
The present invention relates to a processing order setting method for performing diagonal tightening processing.

[0002]

2. Description of the Related Art A large size bolt has been loosened /
Tightening work is an operation that has been desired for mechanization and automation.However, the target equipment is diverse, and the position and size of the bolts are also different for each equipment. Due to the limitations, automation was slow.

Under these circumstances, in an assembly line of some automobile parts, various automatic bolting devices have been proposed, and an automatic assembling device having a recognition means is disclosed in Japanese Patent Application Laid-Open No. 2-256430. The "automatic assembling apparatus and method" is well known. This device automates the work of attaching tires to the car body drum in an automatic assembly line, recognizes the bolt holes of the tires and the bolts of the car body drum with a vision camera, and uses a robot based on the position information to recognize it. After correcting the posture of the tire to be gripped, the tire is mounted on the drum.

The operation in this case is a simple and repetitive operation of mounting a tire on a drum of a vehicle body by a robot. The size of the tire and the size of the bolt are constant, and the recognition means by the vision camera recognizes only positional information. Only go. Therefore, as described above, the target equipment is diversified and cannot be applied to general mechanical equipment in which the positions and sizes of the bolts are random.

[0005] An attempt to improve this point and automate the bolt loosening / tightening operation by recognizing the position and size of the bolt for machine equipment having the position and size of the bolt at random has been disclosed in Japanese Patent Laid-Open No. H10-163,873. 7-1084
No. 26, "Bolt automatic attachment / detachment device".

FIG. 9 is a front view showing the appearance of a conventional automatic bolt attaching / detaching apparatus. The device shown in FIG. 9 moves the illumination camera 15 and the vision camera 14 provided with the rotation mechanisms 24 and 25 by the camera moving trolley 12 provided with the adjustment movement mechanism in the XYZ directions to photograph each part on the target equipment 16. To identify the bolt 2 by image processing and recognition.
The position and size of the bolt 2 are calculated by calculating the position and size of the bolt 2 in a posture in which the vision camera 14 faces the top of the head.

When a socket (a tool attached to the tip of the tool unit 13) corresponding to the recognized size is mounted on the tool unit 13, a controller (not shown) rotates the rotating mechanism 21 from the tool moving cart 11. , 22, the tool unit 13 is set in a posture corresponding to the posture of the bolt 2, and the tool unit 13 is positioned with respect to the bolt 2 based on the position information of the bolt 2. Thus, the socket attached to the tip of the tool unit 13 is connected to the bolt 2, and the tool unit 13 rotates the socket to loosen or tighten the bolt 2. If the mounted socket does not match the recognized size of the bolt 2, it is selected from the socket table 41s and replaced.

[0008]

However, the apparatus disclosed in Japanese Patent Application Laid-Open No. 7-108426 in the above-mentioned conventional example is a vision camera 14 which is a bolt recognizing means.
As a result, not only the position of the bolt 2 but also the bolt size can be recognized.
This is a remarkable improvement when compared with the method that only recognizes the position of the signal, and opens the way to work automation that was difficult for general machinery and equipment where the position and size of the bolt 2 are randomly provided. However, there is a problem that a method for automatically setting a bolt tightening order is not considered.

Accordingly, an object of the present invention is to enhance the function of the above-mentioned automatic bolt / nut attaching / detaching apparatus by automatically setting a work order such as a tightening order in a bolt tightening operation which is not a simple continuous order. An object of the present invention is to provide a method for setting a processing order in an automatic attaching / detaching apparatus.

[0010]

In order to achieve the above object, the present invention provides, for example, a method for mounting and removing a bolt and a nut on a speed reducer having a parallel axis or an orthogonal axis based on information obtained by a bolt and nut detecting means. The mounting / removing device is configured so that the diagonal tightening order at the initial stage of the tightening operation can be automatically set.

According to a first aspect of the present invention, there is provided a bolt-nut detecting means for detecting the coordinates and size of a bolt-nut to be loosened with respect to a bolt-nut fastener. In a bolt and nut automatic attachment / detachment device equipped with bolt / nut attachment / detachment means for attaching / detaching a bolt / nut to / from the bolt / nut fastener based on information obtained by the detection means, the initial tightening operation is performed irrespective of changes in external dimensions and size. Automatically setting the diagonal tightening order based on the coordinate points of each bolt and nut, the centroid of a figure formed by connecting the coordinate points, and the size information of each bolt and nut. In the way.

According to this configuration, the diagonal tightening order of the initial work in the bolt nut fastener or the like is determined by the coordinate points of each bolt and nut, the figure and centroid connecting the coordinate points, and the size of each bolt and nut of four. It can be set automatically based on the point information.

[0013] A specific configuration for realizing the object of the invention according to the present application is characterized in that the bolt and nut fastener is a speed reducer having a parallel axis or a perpendicular axis. A method for setting a processing order in a bolt / nut attaching / detaching apparatus according to claim 1.

According to this configuration, the casing tightening initial operation of the speed reducer having the parallel axis or the orthogonal axis can be automatically set to the diagonal tightening sequence incorporating the know-how of the human operation.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an in-plane imaging diagram of a speed reducer according to an embodiment of the present invention. FIG. 2 is a view showing the positions and sizes of bolt nuts in one plane of the speed reducer shown in FIG. FIG. 3 is a diagram showing a figure created by tying all the bolt nuts shown in FIG. FIG. 4 is a diagram showing a rectangle circumscribing the figure shown in FIG.

Specifically, in this embodiment, the speed reducer casing having the parallel axis or the orthogonal axis shown in FIG. 1 is bolted diagonally to a bolt shown in FIG. An example of automatically fastening using an automatic attaching / detaching device (robot) will be described.

In FIG. 1, reference numeral 1 denotes one plane, such as the top surface of a casing of the speed reducer, which is imaged by the vision camera 14, and 2 denotes a plurality of types of bolts therein. A represents an image frame of the vision camera 14, and X and Y are coordinate axes of the robot imaging system.

In FIG. 2, the position and size of the bolt and nut 2 existing in one plane of the speed reducer 1 are detected by bolt and nut detecting means described later. Here, the bolt size 3 is classified into a large size 3a, a medium size 3b, and a small size 3c, but in the speed reducer 1, if the left side of the drawing is the output shaft side and the right side is the input shaft side,
The bolt size configuration shows that the size of the bolt 2 on the output shaft side having a large operating force is large.

In FIG. 3, reference numeral 4 denotes a figure created by connecting all the detected positions of the bolt and nut 2, and reference numeral 5 denotes a centroid of the figure 4. Here, when creating FIG. 4,
A coordinate value is obtained by dividing the sum of the respective X and Y coordinate values of the bolt and nut 2 by the number of bolt and nut, and for each line created by connecting the coordinate value and each of the bolt and nut coordinates, for example, in a counterclockwise direction. May be specified in descending order of angle, and bolts and nuts may be tied in that order.

In FIG. 4, reference numeral 6 denotes a rectangle circumscribing FIG. 4 and formed so as to have a minimum area.
0 and Y0 are bolt-nut-side coordinate axes drawn in parallel to each side of the rectangle 6, and are different from the coordinate axes X and Y of the previous imaging system.

FIG. 5 shows NO from the bolt coordinate axis shown in FIG.
It is explanatory drawing at the time of selecting 1, NO2 volt. FIG. 6 is a diagram showing coordinate points when the NO1 volt shown in FIG. 5 is selected. FIG. 7 shows the N1 and NO2 volts shown in FIG.
It is explanatory drawing at the time of selecting O3 and NO4 volts. FIG.
FIG. 8 is a diagram showing conversion of the bolt and nut coordinate points shown in FIG. 7 into imaging system coordinates.

Next, the operation will be described with reference to the drawings. First, the speed reducer 1 is arranged at the position of the target equipment 16 using the automatic bolt attachment / detachment apparatus shown in FIG.
To take an entire one-dimensional image from the upper surface as shown in FIG. In this case, the image of the speed reducer 1 is taken with the screen inclined to facilitate the pattern matching with respect to the coordinates X and Y of the imaging system. FIG. 1 shows the overall arrangement of the bolts and nuts 2.

Now, even if the shape is a hexagon bolt,
In this state, the outline of the head of each bolt may not be clear. Then, the vision camera 14 is directly faced to the top of each bolt 2 and zoomed. An image of a bolted image with shadows illuminated from two directions is taken, and the image processing circuit (not shown) performs a logical OR operation on the images to extract the head shape of the hexagonal bolt from which the shadow portion has been removed and extracted. The shape of the bolt 2 is automatically recognized by the collation judgment of the contour feature for confirming the 120 ° angle from the hexagonal shape. Also, the camera 14
The distance to the bolt 2 is measured from the position coordinates, trigonometry, zoom magnification, etc. of the bolt 2 by calculating the actual length and size of the hexagonal portion by matching the shape of the bolt 2 previously recognized. Automatically recognize position and size. The operation of the bolt / nut detecting means has been described above, whereby the position and size of all bolts are detected. This state is shown in FIG.
In FIG. 2, these recognized bolt sizes 3 are divided into large, medium, and small 3a, 3b, and 3c.

Next, as shown in FIG. 3, a figure 4 connecting all the bolts and nuts 2 is created from the detected all bolt and nut position information, and a centroid 5 of this figure is calculated. Where CRT
An image of all bolts and nuts may be presented above, and a person (operator) may input how to tie each individual bolt and nut. Subsequently, as shown in FIG. 4, a rectangle 6 circumscribing the created figure 4 and having the smallest area is created, and two straight lines passing through the centroid 5 parallel to each side of the rectangle 6 are defined as X0 and Y0. . This avoids calculation errors,
The previous coordinates X and Y of the imaging system are converted to independent bolt and nut side coordinates X.
The coordinates are once converted to 0 and Y0.

Next, the diagonal tightening bolts NO1 to NO
4 will be described.

(1) Selection of NO1 volt As shown in FIG. 5, the position of NO1 volt is determined by comparing the two bolts (four shown) included in the maximum size 3a detected in FIG. Elect. The collation determination processing will be described with reference to FIG. FIG. 6 (a)
Is a quadrant display within the coordinates X0, Y0 of the bolt and nut,
The coordinate points of the bolt 2 are divided by the first to fourth quadrants. That is, the coordinate point table shown in FIG. 6B shows “maximum size bolt position” in the left column, “NO1 bolt coordinate” in the right column, and “maximum size bolt position” is the maximum as shown in FIG. The quadrant NO indicates which quadrant and which quadrant the bolt 2 of size 3a is in. In the example of FIG. 5, the number of bolts included in the maximum size 3a is four, and two bolts are present at the top and bottom, that is, two bolts are present in the second and third quadrants. The eye quadrant NO is "2,
In this case, the "NO1 bolt coordinate" in the right column is (X0min, Y0max). When these coordinates are viewed on FIG. 5, the leftmost point on the X0-axis side on the X0- side and the uppermost point on the Y0 + side on the Y0 axis. The intersection of the points, that is, the position of NO1.

If the “maximum size bolt position” is “1, 2” as shown in the first row of the table, the first quadrant and the second quadrant are present. (X0
max, Y0max), and in FIG. 5, at the upper right position in the figure, a point that is point-symmetric with the coordinate point of the previous NO1 volt position with respect to the Y0 straight line is selected as the NO1 volt position in this case. become. As described above, the “maximum size bolt position” also indicates the direction of the speed reducer 1, so that the direction of the speed reducer 1 can be recognized.

(2) Selection of NO2 bolts First, when the position of the NO1 bolt to be tightened is determined, then, as shown in FIG. Of the bolts and nuts 2 present near the position
O2 volts.

(3) Selection of NO3 and NO4 bolts Once the coordinate points of the NO1 and NO2 bolt nuts are determined, a straight line parallel to the X0 and Y0 straight lines is passed through the coordinates of the NO1 and NO2 bolts as shown in FIG. Pull out and select two bolt nuts near the intersection except for the positions of the NO1 and NO2 bolts among the four possible intersections. Since the third quadrant is within 3a, a large-sized bolt near the intersection is designated as NO.
In the first quadrant, the larger bolt on the shaft side near the intersection is selected as NO4.

When the coordinate points NO1 to NO4 are determined, the coordinate conversion is performed again as shown in FIG. 8 to return the X0 and Y0 coordinates to the X and Y coordinates. The controller controls the tool unit 13 to perform diagonal tightening in the order of NO1-NO2-NO3-NO4 bolts, and then sequentially tightens all other intermediate bolts 2 to reduce the speed of the reduction gear 1
The fastening of the casing is ended. When the bolts are loosened and the bolts 2 are removed, the procedure is reversed, and the removed bolts 2 are arranged side by side on the bolt table 41 in order. If the diagonal tightening is automatically performed as described above, an average weight-adding type tightening operation can be performed, and an inconvenience such as a failure in tightening can be avoided.

[0031]

As described above, according to the present invention,
This is a bolt nut automatic attachment / detachment device that attaches / detaches bolt / nuts to / from bolted nuts such as reduction gears.The diagonal tightening sequence at the beginning of the tightening work regardless of changes in external dimensions and size, etc. Automatically set based on the centroid of the figure formed by connecting the points and the size information of each bolt and nut, so that the know-how of human work such as diagonal tightening is incorporated into the automation work to ensure reliable tightening and assembly work And saves energy by enabling these to be automatically set, and versatility is improved by using unspecified number of symmetrical workpieces such as reduction gears, axial flow pumps, fluid couplings, etc. It is possible to consolidate equipment.

[Brief description of the drawings]

FIG. 1 is an in-plane imaging diagram of a speed reducer according to an embodiment of the present invention.

FIG. 2 is a view showing positions and sizes of bolts and nuts in one plane of the speed reducer shown in FIG. 1;

FIG. 3 is a diagram showing a view in which all bolts and nuts shown in FIG. 2 are tied and created.

FIG. 4 is a diagram showing a rectangle circumscribing the graphic shown in FIG. 3;

FIG. 5 is an explanatory diagram for selecting NO1 and NO2 bolts from the bolt coordinates shown in FIG. 4;

FIG. 6 is a view showing coordinate points of the NO1 volt shown in FIG. 5;

FIG. 7 shows NO3 and NO3 bolts shown in FIG.
It is explanatory drawing at the time of selecting NO4 volt.

8 is a diagram showing conversion of the bolt coordinate points shown in FIG. 7 into imaging system coordinates.

FIG. 9 is a front view showing the appearance of a conventional automatic bolt attaching / detaching apparatus.

[Explanation of symbols]

 1 speed reducer 2 bolt nut 3 bolt size 4 figure connecting all bolt nuts 5 centroid 6 rectangle

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Toshiyuki Naoi 1421 Hitomi Kimitsu City (56) References JP-A-7-108426 (JP, A) JP-A-2-256430 (JP, A) JP JP-A-4-101737 (JP, A) JP-A-7-276158 (JP, A) JP-A-60-56874 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23P 19 / 06

Claims (2)

(57) [Claims] The present invention further comprises a bolt and nut detecting means for detecting the coordinates and size of a bolt and nut to be loosened and tightened with respect to the bolt and nut fastener, and the bolt and nut fastener is attached to the bolt and nut fastener based on information obtained by the detecting means. In a bolt and nut automatic attaching / detaching device equipped with a bolt and nut attaching / detaching means for attaching and detaching, the diagonal tightening order at the initial tightening operation is determined by connecting the coordinate points of each bolt and nut to the coordinate point regardless of changes in external dimensions and sizes. A processing sequence setting method in an automatic bolt and nut attaching / detaching apparatus, wherein the processing sequence is automatically set based on a centroid of a possible figure and size information of each bolt and nut. 2. The method according to claim 1, wherein the bolt and nut fastener is a speed reducer having a parallel axis or an orthogonal axis.