Device and method for detecting rotation of end part of steel pipe bar

Abstract

The invention discloses a steel pipe bar end rotation detection device which is arranged at the tail end of an arm of a six-axis robot and comprises a mounting bottom plate, and a collision buffering mechanism, a rotation detection mechanism and a coarse positioning mechanism which are arranged on the mounting bottom plate, the mounting bottom plate is arranged at the tail end of an arm of the six-axis robot; the collision buffering mechanism is arranged on the mounting bottom plate and is close to the middle position of the mounting bottom plate; the rotation detection mechanism is arranged on the installation bottom plate through an angle adjusting mechanism and located on one side of the collision buffering mechanism. And the coarse positioning mechanism is arranged at the end part of the mounting bottom plate. The invention also discloses a method for detecting the rotation of the end part of the steel pipe bar. The device can adapt to the sizes of various steel pipes and bar products, achieves the 360-degree all-round detection function on the ends of the steel pipes and the bars, and can completely replace a manual detection mode.

Description

TECHNICAL FIELD

[0001] The present application relates to a steel pipe defect detection technology, more particularly to a steel pipe rod end rotation detection device and method. BACKGROUND

[0002] The steel pipe and rod deep processing industry needs to perform machining processes such as external threading, chamfering, end face turning, and boring on the end of the steel pipe and rod during production. After machining, manual measurement of the diameter and other sizes is performed, and manual inspection of the appearance quality such as whether the threading is complete is performed. After the end of the steel pipe and rod is machined, it is transported to subsequent workstations such as a step conveyor and a roller bed for subsequent processes such as flaw detection, rust removal, oiling, marking, and packaging. During the transportation process of the subsequent processes, the machined surface of the end of the steel pipe and rod can come into contact with the conveying components, thereby causing defects such as friction and scratches on the machined surface. Therefore, manual appearance inspection and size measurement of the machined surface are performed again before the steel pipe and rod are packaged to prevent defective products from flowing to the user.

[0003] However, since the end of the steel pipe and rod is a mirror surface product after machining, manual visual inspection is performed, which not only causes missed detection and missed detection, but also causes fatigue of the eyes of the personnel, thereby damaging the health of the personnel. SUMMARY

[0004] In view of the defects in the prior art, the present application aims to provide a steel pipe rod end rotation detection device and method that can adapt to various steel pipe and rod product sizes and achieve 360-degree full-circle detection of the end of the steel pipe and rod, thereby completely replacing manual detection.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] The present application provides a steel pipe rod end rotation detection device in a first aspect, which is arranged on the end of the arm of a six-axis robot and includes a mounting base, a collision buffer mechanism, a rotation detection mechanism, and a coarse positioning mechanism arranged on the mounting base;

[0007] The mounting base is arranged on the end of the arm of the six-axis robot;

[0008] The collision buffer mechanism is arranged on the mounting base, close to the middle position of the mounting base;

[0009] The rotation detection mechanism is arranged on the mounting base through an angle adjustment mechanism and located on one side of the collision buffer mechanism;

[0010] The coarse positioning mechanism is arranged at the end position of the mounting base.

[0011] Preferably, the collision buffering mechanism comprises a buffering seat, a guide column, a reset spring, a collision baffle, a linear bearing seat and a proximity switch.

[0012] The front side of the collision baffle is used to touch the end of the steel pipe;

[0013] One end of the guide column is connected to the rear side of the collision baffle;

[0014] The rear side of the buffering seat is connected to the mounting bottom plate;

[0015] The linear bearing seat is arranged on the front side of the buffering seat;

[0016] The other end of the guide column penetrates into the linear bearing seat and the front side of the buffering seat, and reciprocates in the linear bearing seat;

[0017] The proximity switch is arranged on the buffering seat and cooperates with the guide column;

[0018] The reset spring is sleeved on the guide column and located between the collision baffle and the linear bearing seat;

[0019] The proximity switch is connected with the upper controller to establish data communication connection.

[0020] Preferably, the rotation detection mechanism comprises a measuring instrument box and a connecting plate;

[0021] The 2D camera and the 3D camera are installed in the measuring instrument box;

[0022] The upper end of the connecting plate is connected to the bottom of the measuring instrument box, and the lower end is connected to the angle adjustment mechanism.

[0023] Preferably, the angle adjustment mechanism comprises a mounting plate and an angle motor;

[0024] The mounting plate is arranged on the mounting bottom plate;

[0025] The angle motor is arranged on the mounting plate;

[0026] The lower end of the connecting plate is connected to the angle motor.

[0027] Preferably, the coarse positioning mechanism comprises a ranging rod and a point laser sensor;

[0028] One end of the ranging rod is connected to the end position of the mounting bottom plate;

[0029] The point laser sensor is arranged on the other end of the ranging rod.

[0030] The second aspect of the present invention provides a method for detecting the rotation of the end of a steel pipe or bar, wherein the following steps are performed using the device for detecting the rotation of the end of a steel pipe or bar provided in the first aspect of the present invention:

[0031] S1, coarse positioning;

[0032] S2, calculate and generate the composite trajectory;

[0033] S3, the angle and posture adjustment of the rotation detection mechanism;

[0034] S4, begin measurement;

[0035] S5, measurement data generates the position of the steel pipe;

[0036] S6, precise positioning and measurement.

[0037] Preferably, step S1 specifically includes:

[0038] The six-axis robot moves forward while holding the device for detecting the rotation of the steel pipe end. When the collision buffer mechanism contacts the end of the steel pipe, the upper controller receives a signal from the proximity switch, and the six-axis robot stops moving forward.

[0039] While the six-axis robot holds the steel pipe bar end rotation detection device and rotates around the steel pipe, the point laser sensor emits a point laser and projects it onto the end surface of the steel pipe to measure the surface position and diameter of the steel pipe.

[0040] Preferably, step S3 specifically includes:

[0041] The relative position and angle between the measuring instrument box and the steel pipe are adjusted by the angle motor to change the measuring range of the measuring instrument box and the end contact angle of the steel pipe.

[0042] When the measuring instrument box is in the 0-degree position, it is used to measure the end face of the steel pipe;

[0043] When the measuring instrument box is at a 45-degree position, it is used to measure the end edge of the steel pipe;

[0044] When the measuring instrument box is in the 90-degree position, it is used to measure the cylindrical surface of the steel pipe.

[0045] Preferably, steps S4 and S6 are both achieved through the combined rotation of the steel pipe bar end rotation detection device.

[0046] Preferably, the composite rotation for the steel pipe / bar end rotation detection device specifically includes:

[0047] The six-axis robot, holding the steel pipe bar end rotation detection device, moves in a concentric circle around the axis of the steel pipe, performing circular trajectory motion.

[0048] The six-axis robot rotates 360 degrees around the axis of the six-axis robot while holding the end rotation detection device for steel pipes and bars.

[0049] This invention provides a device and method for rotating the ends of steel pipes and bars. The rotating detection device enables rotational detection of the ends of steel pipes and bars, and can complete 360-degree full-coverage detection of the cylindrical surface, edges, end faces, and inner hole edges of the ends. It also has the following beneficial effects:

[0050] (1) The measuring angle of the rotating detection mechanism can be adjusted to achieve detection of various parts and the best detection effect.

[0051] (2) The measuring instrument box is equipped with a 3D camera and a 2D camera, which can measure the 3D shape of the end of the steel pipe and take photos of the end appearance at the same time.

[0052] (3) The six-axis robot clamping device is used for the rotation detection of the end of steel pipes and bars. It can adapt to steel pipes and bars of different diameters, adopt the best motion trajectory, and ensure that the measured part is within the best measurement range of the camera. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the overall structure of the steel pipe bar end rotation detection device of the present invention;

[0054] Figure 2 This is a schematic diagram of the collision buffer mechanism in the steel pipe bar end rotation detection device of the present invention;

[0055] Figure 3 This is a schematic diagram of the rotating detection mechanism and coarse positioning mechanism in the rotating detection device for the end of steel pipes and bars of the present invention;

[0056] Figure 4 This is a schematic diagram of the composite motion of the steel pipe / bar end rotation detection device of the present invention;

[0057] Figure 5 This is a schematic flowchart of the method for detecting the end rotation of steel pipe bars according to the present invention;

[0058] Figure 6 This is a schematic diagram of step S3 in the method for detecting the rotation of the end of a steel pipe bar according to the present invention. (a) shows the adjustment to 0 degrees, (b) shows the adjustment to 45 degrees, and (c) shows the adjustment to 90 degrees.

[0059] Figure 7This is a schematic diagram of a 2D camera taken in the steel pipe and bar end rotation detection device of the present invention;

[0060] Figure 8 This is a schematic diagram of the model created by the 3D camera in the steel pipe and bar end rotation detection device of the present invention.

[0061] Figure 9 This is a schematic diagram of the present invention used in the rotating detection device for the end of steel pipes and bars to measure and acquire three-dimensional data points on the surface of the object to be measured, and then calculate the curvature. Detailed Implementation

[0062] To better understand the above-mentioned technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0063] Combination Figure 1 As shown, the present invention provides a rotating detection device for the end of a steel pipe / bar, which is mounted on the end arm of a six-axis robot 100. The six-axis robot 100 holds the rotating detection device and rotates it 360 degrees around the end center of the steel pipe 500 to achieve dimensional measurement and visual imaging of the end of the steel pipe 500. The rotating detection device for the end of the steel pipe / bar includes a mounting base plate 1, and a collision buffer mechanism 200, a rotating detection mechanism 300, and a coarse positioning mechanism 400 mounted on the mounting base plate 1.

[0064] Mounting base plate 1 is installed on the end of the arm of the six-axis robot 100.

[0065] The collision buffer mechanism 200 is installed on the mounting base plate 1 and is installed near the middle of the mounting base plate 1.

[0066] The rotation detection mechanism 300 is mounted on the mounting base plate 1 via the angle adjustment mechanism 600 and is located on one side of the collision buffer mechanism 200.

[0067] The coarse positioning mechanism 400 is installed at the end of the mounting base plate 1.

[0068] Combination Figure 2 As shown, the collision buffer mechanism 200 includes a buffer seat 201, a guide post 202, a return spring 203, a collision baffle 204, a linear bearing seat 205, and a proximity switch 206.

[0069] The front side of the collision baffle 204 is used to contact the end of the steel pipe 500.

[0070] One end of the guide post 202 is connected and fixed to the rear side of the collision baffle 204.

[0071] The rear side of the buffer seat 201 is connected and fixed to the mounting base plate 1.

[0072] The linear bearing housing 205 is mounted on the front side of the buffer housing 201.

[0073] The other end of the guide post 202 passes through the front side of the linear bearing housing 205 and the buffer housing 201, and reciprocates along the inside of the linear bearing housing 205.

[0074] The proximity switch 206 is mounted on the buffer seat 206 and forms a mating relationship with the guide post 202.

[0075] The reset spring 203 is mounted on the guide post 202 and is located between the collision baffle 204 and the linear bearing seat 205.

[0076] The proximity switch 206 establishes a data communication connection with the host controller.

[0077] When the collision buffer mechanism 200 moves toward the steel pipe 500, the collision baffle 204 contacts the steel pipe. The collision baffle 204 and the guide post 202 move together toward the opposite direction of the steel pipe 500, while compressing the reset spring 203. After running a certain distance, the guide post 202 enters the sensing range of the proximity switch 206. The proximity switch 206 sends a signal, and the upper controller receives the signal from the proximity switch 206 and controls the six-axis robot 100 to stop moving.

[0078] When the collision buffer mechanism 200 separates from the steel pipe 500, the reset spring 203 is released, driving the collision baffle 204 to move toward the steel pipe 500 and return to its initial position.

[0079] Combination Figure 3 As shown, the rotating detection mechanism 300 includes a measuring instrument box 301 and a connecting plate 302.

[0080] The measuring instrument box 301 is equipped with a 2D camera and a 3D camera. The end of the steel pipe 500 is located within the measuring range 303 of the 3D camera. The 2D camera and the 3D camera are used to scan the end position of the steel pipe 500 and take pictures.

[0081] The upper end of the connecting plate 302 is connected to the bottom of the measuring instrument box 301, and the lower end is connected to the angle adjustment mechanism 600.

[0082] The angle adjustment mechanism 600 includes a mounting plate 601 and an angle motor 602.

[0083] Mounting plate 601 is connected and fixed to mounting base plate 1.

[0084] Angle motor 602 is mounted on mounting plate 601.

[0085] The lower end of the connecting plate 302 is connected and fixed to the angle motor 602, and the measuring instrument box 301 can be adjusted arbitrarily between 0 degrees and 90 degrees through the angle motor 602.

[0086] The coarse positioning mechanism 400 includes a ranging rod 401 and a point laser sensor 402.

[0087] One end of the ranging rod 401 is connected and fixed to the end position of the mounting base plate 1.

[0088] The point laser sensor 402 is installed at the other end of the ranging rod 401, facing the steel pipe 500.

[0089] The point laser sensor 402 emits a point laser 403 which is emitted onto the steel pipe 500 to measure the position and diameter of the upper surface of the steel pipe 500.

[0090] Combination Figure 5 As shown, the present invention also provides a method for detecting the rotation of the ends of steel pipes and bars. The following steps are performed using the device for detecting the rotation of the ends of steel pipes and bars of the present invention:

[0091] S1, coarse positioning;

[0092] S2, calculate and generate the composite trajectory;

[0093] S3, 300° angle adjustment of the rotating detection mechanism;

[0094] S4, begin measurement;

[0095] S5, measurement data generates the position of the steel pipe;

[0096] S6, precise positioning and measurement.

[0097] The above step S1 specifically includes:

[0098] The six-axis robot 100 grips the steel pipe bar end rotation detection device of the present invention and moves forward. When the collision baffle 204 in the collision buffer mechanism 200 contacts the end of the steel pipe 500, the collision baffle 204 and the guide post 202 move together in the opposite direction of the steel pipe 500, and at the same time compress the reset spring 203. After running a certain distance, the guide post 202 enters the sensing range of the proximity switch 206. The proximity switch 206 sends a signal, and the upper controller receives the signal from the proximity switch 206 and controls the six-axis robot 100 to stop moving.

[0099] The six-axis robot 1 holds the steel pipe bar end rotation detection device of the present invention and rotates around the steel pipe 500 for one revolution. At the same time, the point laser sensor 402 emits a point laser 403 which is projected onto the end surface of the steel pipe 500 to measure the surface position (height) and diameter of the steel pipe 500.

[0100] The above step S3 specifically includes:

[0101] The relative position and angle between the measuring instrument box 301 and the steel pipe 500 are adjusted by the angle motor 602 to change the measuring range of the measuring instrument box 301 and the end contact angle of the steel pipe 500, thereby achieving the best measurement results. Furthermore, adjusting the angle of the angle motor 602 allows for measurements at different positions on the end of the steel pipe 500.

[0102] When the measuring instrument box 301 is in the 0-degree position, it is used to measure the end face of the steel pipe 500, such as... Figure 6 As shown in (a).

[0103] When the measuring instrument box 301 is in the 45-degree position, it is used to measure the end edge of the steel pipe 500, such as... Figure 6 As shown in (b).

[0104] When the measuring instrument box 301 is in the 90-degree position, it is used to measure the cylindrical surface of the steel pipe 500, such as... Figure 6 As shown in (c).

[0105] Steps S4 and S6 above are both achieved through the composite rotation of the steel pipe bar end rotation detection device of the present invention.

[0106] Combination Figure 4 As shown, the present invention is used for the composite rotation of the steel pipe bar end rotation detection device to adapt to different diameters D of the steel pipe 500, ensuring that the target measurement area is within the effective measurement range of the measuring instrument box 301.

[0107] Specifically, it includes:

[0108] 1) Circular trajectory motion A: The six-axis robot 100 clamps the steel pipe / bar end rotation detection device of this invention and moves it along a concentric circle around the axis 501 of the steel pipe 500. This trajectory is circular trajectory motion A, and the radius of circular trajectory motion A is 'a'. The value of 'a' is calculated based on the radius of the steel pipe 500 and the angle of the measuring instrument box 301 adjusted by the angle motor 602. The calculated circular trajectory of the overall movement of the steel pipe / bar end rotation detection device of this invention must ensure that the target measurement area of ​​the steel pipe 500 is within the measurement range of the measuring instrument box 301.

[0109] 2) Rotational motion B: The six-axis robot 100 clamps the steel pipe / bar end rotation detection device of this invention and rotates it 360 degrees around the axis 101 of the six-axis robot 100. The rotation trajectory is rotational motion B. Rotational motion B must ensure that the point laser 403 of the laser sensor 402 is in the radial plane of the steel pipe 500 passing through the center of the steel pipe 500, so as to ensure that the measuring plane of the point laser 403 is parallel to the normal of the outer surface of the steel pipe 500.

[0110] By coordinating the various mechanisms of the rotating detection device for the ends of steel pipes and bars according to this invention, the target measurement area can be precisely located within the optimal measurement range of both the 3D and 2D cameras, achieving optimal imaging quality and measurement accuracy. This invention allows the rotating detection device for the ends of steel pipes and bars to rotate one revolution, generating 2D images from the 2D camera and 3D data models from the 3D camera, as shown in the diagram. Figure 7 and Figure 8 As shown.

[0111] The surface of a steel pipe or bar is a smooth curved surface. After 2D and 3D cameras measure and acquire three-dimensional data points on the surface of the object being measured, a three-dimensional curved surface can be obtained. By calculating the curvature of all points on the surface, if the curvature is abnormal, it is determined to be a defect.

[0112] Combination Figure 9 As shown, each direction of the surface has a normal curvature, and therefore a minimum and a maximum normal curvature. These minimum and maximum values ​​are the principal curvatures, denoted as K1 and K2, respectively. The tangent direction of the curve at that point is the direction of the principal curvature. Calculate the difference between the minimum and maximum values ​​of a point Pn, i.e., the curvature difference: Dkn = K2 - K1.

[0113] The surface to be measured is divided into multiple grids, each grid having n points. The sum of the curvature differences Sn of the n points in each grid is calculated one by one.

[0114] Sn=Dk1+Dk2+....Dkn

[0115] The surface of the defect is an irregular, abnormal surface. The deeper the defect, the larger its area, and the larger the Sn of the defect location. The defect alarm threshold is T; a defect is identified when Sn > T. The value of T is determined based on the type of object being tested, using an empirical value.

[0116] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A device for detecting the rotation of the end of a steel pipe or bar, mounted on the end of the arm of a six-axis robot, characterized in that: It includes a mounting base plate, and a collision buffer mechanism, a rotation detection mechanism and a coarse positioning mechanism disposed on the mounting base plate; The mounting base plate is located on the end of the arm of the six-axis robot; The collision buffer mechanism is located on the mounting base plate, near the middle of the mounting base plate; The rotation detection mechanism is mounted on the mounting base plate via an angle adjustment mechanism and is located on one side of the collision buffer mechanism; The coarse positioning mechanism is located at the end of the mounting base plate.

2. The device for detecting the end rotation of steel pipe bars according to claim 1, characterized in that: The collision buffer mechanism includes a buffer seat, a guide post, a return spring, a collision baffle, a linear bearing seat, and a proximity switch; The front side of the collision baffle is used to contact the end of the steel pipe; One end of the guide post is connected to the rear side of the collision baffle; The rear side of the buffer seat is connected to the mounting base plate; The linear bearing housing is located on the front side of the buffer housing; The other end of the guide post passes through the front side of the linear bearing housing and the buffer housing, and reciprocates along the inside of the linear bearing housing; The proximity switch is mounted on the buffer seat and engages with the guide post. The reset spring is fitted onto the guide post and is located between the collision baffle and the linear bearing seat; The proximity switch establishes a data communication connection with the host controller.

3. The device for detecting the end rotation of steel pipe bars according to claim 1, characterized in that: The rotating detection mechanism includes a measuring instrument box and a connecting plate; The measuring instrument box is equipped with a 2D camera and a 3D camera; The upper end of the connecting plate is connected to the bottom of the measuring instrument box, and the lower end is connected to the angle adjustment mechanism.

4. The device for detecting the end rotation of steel pipe bars according to claim 3, characterized in that: The angle adjustment mechanism includes a mounting plate and an angle motor; The mounting plate is disposed on the mounting base plate; The angle motor is mounted on the mounting plate; The lower end of the connecting plate is connected to the angle motor.

5. The device for detecting the end rotation of steel pipe bars according to claim 1, characterized in that: The coarse positioning mechanism includes a rangefinder and a point laser sensor; One end of the ranging rod is connected to the end of the mounting base plate; The point laser sensor is located on the other end of the ranging rod.

6. A method for detecting the rotation of the end of a steel pipe or bar, characterized in that, The following steps are performed using the steel pipe / bar end rotation detection device as described in any one of claims 1-5: S1, coarse positioning; S2, calculate and generate the composite trajectory; S3, the angle and posture adjustment of the rotation detection mechanism; S4, begin measurement; S5, measurement data generates the position of the steel pipe; S6, precise positioning and measurement.

7. The method for detecting end rotation of steel pipe bars according to claim 6, characterized in that, Step S1 specifically includes: The six-axis robot moves forward while holding the device for detecting the rotation of the steel pipe end. When the collision buffer mechanism contacts the end of the steel pipe, the upper controller receives a signal from the proximity switch, and the six-axis robot stops moving forward. While the six-axis robot holds the steel pipe bar end rotation detection device and rotates around the steel pipe, the point laser sensor emits a point laser and projects it onto the end surface of the steel pipe to measure the surface position and diameter of the steel pipe.

8. The method for detecting end rotation of steel pipe bars according to claim 6, characterized in that, Step S3 specifically includes: The relative position and angle between the measuring instrument box and the steel pipe are adjusted by the angle motor to change the measuring range of the measuring instrument box and the end contact angle of the steel pipe. When the measuring instrument box is in the 0-degree position, it is used to measure the end face of the steel pipe; When the measuring instrument box is at a 45-degree position, it is used to measure the end edge of the steel pipe; When the measuring instrument box is in the 90-degree position, it is used to measure the cylindrical surface of the steel pipe.

9. The method for detecting end rotation of steel pipe bars according to claim 6, characterized in that: Both steps S4 and S6 are achieved through the combined rotation of the device for detecting the rotation of the ends of steel pipe bars.

10. The method for detecting end rotation of steel pipe bars according to claim 9, characterized in that, The composite rotation used in the steel pipe / bar end rotation detection device specifically includes: The six-axis robot, holding the steel pipe bar end rotation detection device, moves in a concentric circle around the axis of the steel pipe, performing circular trajectory motion. The six-axis robot rotates 360 degrees around the axis of the six-axis robot while holding the end rotation detection device for steel pipes and bars.

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