A system and method for identifying the front and back sides of a ring-shaped workpiece

Abstract

The present application relates to the technical field of automatic feeding, and particularly relates to a front and back surface identification system of a ring-shaped workpiece, which is suitable for a ring-shaped workpiece provided with a flange on the outer side or the inner side, and comprises a workpiece conveying mechanism, which is used for conveying the ring-shaped workpiece to a set position according to a reference surface; a detection mechanism, which is used for detecting a ring surface of the ring-shaped workpiece; the distance d2 between the detection area of the detection mechanism and the reference surface is configured as follows: the flange thickness d3 of the ring-shaped workpiece < the distance d2 < the ring surface width d1 of the ring-shaped workpiece; and a controller outputs an identification signal according to the length of the sensor signal. The front surface and the back surface of the workpiece are sensed at a specific position, and the front surface and the back surface of the workpiece are judged through the duration of the signal; even if the size of the workpiece changes beyond the set range, only the preset value in the controller needs to be changed, so that the adjustment can be extremely conveniently completed.

Description

Technical Field

[0001] This invention relates to the technical field of automated feeding, and specifically to a system and method for identifying the front and back sides of a ring-shaped workpiece. Background Technology

[0002] In modern automated production, it is usually necessary to identify the front and back of ring-shaped workpieces, and then arrange them in front or back form to ensure that all shape features are consistent before proceeding with subsequent automated processing steps.

[0003] In existing technologies, the identification of the front and back of a ring-shaped workpiece includes the following methods: ① structural filtering on the channel; ② sensor identification; ③ machine vision identification; ④ human visual identification. Each of these identification methods or structures has some drawbacks, specifically: 1. For structural filtering methods, such as the automatic ring flanging machine disclosed in CN201810100047.3, a channel structure (e.g., using an outer chamfer feature to identify the front and back of the workpiece, or using a recessed feature on the front side to identify the front and back) is used, along with an air blower to flip the material, to achieve the identification of the front and back of the material. This method has high accuracy and speed, but the problem is that each filtering structure is mostly only applicable to products of one size. If the outer diameter of the workpiece changes (larger or smaller), the same structure cannot identify it and needs to be replaced with a corresponding identification structure. If there are many workpiece models with different shapes and sizes, multiple identification structures of different sizes need to be matched.

[0004] 2. For methods using sensors to identify the differences in the front and back of a structure, such as the toothbrush handle front and back detection device disclosed in CN201420551561.6 for a toothbrush bristle feeding machine, an acoustic sensor is used to accurately determine the frequency difference of vibration between the front and back sides to achieve material front and back identification. However, this method is costly and has poor versatility. Another example is using proximity sensors, which are generally only suitable for detecting metal objects (assuming a metal object passes within 3mm), but are generally not suitable for detecting the front and back of materials alone. The thickness of the material is fixed, and detection is triggered regardless of front or back when the material passes through the detection area. Alternatively, two proximity sensors can be used together to detect the front and back of the material. However, additional sensors increase costs and reduce the versatility of identification; the position of additional sensors needs to be adjusted every time the workpiece size changes.

[0005] 3. Regarding machine vision recognition methods, for example, CN202120140295.8 discloses a vision screening mechanism that identifies the front and back of plastic parts through a vision recognition screening mechanism, thereby achieving the screening of the front and back of the material. Machine vision is expensive, and the image processing program will become ineffective after the shape and size of the workpiece changes, requiring the program to be modified again.

[0006] 4. The method of human visual recognition is labor-intensive and the efficiency of human labor is lower than that of automated machines. Careless employees may miss the reverse side of the workpiece. Summary of the Invention

[0007] The purpose of this invention is to provide a front and back identification system with good adaptability, which can be used when the size of the material to be detected varies within a certain range and is also universal.

[0008] The objective of this invention is achieved as follows: A front and back recognition system for a ring-shaped workpiece, applicable to ring-shaped workpieces with flanges on the outer or inner sides, comprising: A workpiece conveying mechanism is used to transport the annular workpiece to a set position along a set trajectory; the trajectory includes at least a straight track, and the straight track is provided with a reference surface; the reference surface is in contact with the outer circular surface of the annular workpiece during its movement. The detection mechanism includes a sensor; the sensor's probe is oriented toward the straight trajectory and is used to detect the annular plane of the annular workpiece; the distance d2 between the detection area and the reference plane is configured such that: the flange thickness d3 of the annular workpiece < distance d2 ≤ the annular width d1 of the annular workpiece; The controller is connected to the sensor and is configured to output an identification signal based on the length of the sensor signal when a sensor signal is received.

[0009] Preferably, the workpiece conveying mechanism includes a fixed base, a slide table, a slide table driving device, and a robot arm; the slide table slides within the fixed base, and the slide table driving device drives the slide table; a robot arm is provided on the slide table, and the robot arm is used to grip or release the annular workpiece.

[0010] Preferably, the workpiece conveying mechanism includes a frame, and a conveying channel is provided inside the frame; the conveying channel is used to constrain the annular workpiece to be inspected, so that the annular workpiece moves along a set trajectory; one side of the conveying channel forms the reference surface.

[0011] Preferably, the width of the conveying channel corresponds to the thickness of the annular workpiece; the conveying channel is used for vertical rolling feeding of the annular workpiece; the bottom surface of the conveying channel forms the reference surface.

[0012] Preferably, the conveying channel is inclined at a certain angle, with the inlet end of the conveying channel being higher and the outlet end being lower.

[0013] Preferably, it further includes: a workpiece speed control device, which is disposed on one side of the frame and is used to control the annular workpiece to pass through the probe at a set speed.

[0014] Preferably, the workpiece speed control device includes a drive motor or an indexer, which drives an actuating component; the actuating component is used to push the annular workpieces one by one; the actuating component is cross-shaped or Y-shaped; the rotation plane of the actuating component is perpendicular to the reference plane.

[0015] Preferably, it further includes an actuating component; the actuating component is used to remove or flip the annular workpiece; the actuating component is disposed on the front side of the conveying direction of the conveying channel; The actuating component includes a cylinder and a push rod. The cylinder pushes the push rod into or out of the conveying channel. When the push rod enters the conveying channel, it pushes the annular workpiece away from the conveying channel. The push rod is mounted on the piston rod of the cylinder or the push rod and the piston rod are integrally formed.

[0016] A method for identifying the front and back of a ring-shaped workpiece, applicable to ring-shaped workpieces with flanges on the outer or inner sides, the method comprising the following steps: A trajectory is constructed for conveying a ring-shaped workpiece; the trajectory includes a straight line; a reference surface is set according to the straight line; the ring-shaped workpiece is moved on the reference surface at a set speed, and the outer circular surface of the ring-shaped workpiece is in contact with the reference surface; A sensor is used to detect the annular plane of the annular workpiece; the distance d2 between the detection area and the reference surface is configured such that: the flange thickness d3 of the annular workpiece < the distance d2 ≤ the annular width d1 of the annular workpiece; The sensor transmits the detected signal to the controller; the controller records the signal duration T of the sensor and compares the signal duration T with a preset value; when the signal duration T ≥ the preset value, the annular workpiece is identified as the front side; when the signal duration < the preset value, the annular workpiece is identified as the back side.

[0017] Preferably, the width of the conveying channel corresponds to the thickness of the annular workpiece; the annular workpiece rolls or translates past the sensor.

[0018] The outstanding and beneficial technical effects of this invention compared to the prior art are: This solution is applicable to ring-shaped workpieces with specific structures. When the workpiece rolls past the sensor, both its front and back positions will trigger a detection signal. However, when sensing the front and back of the workpiece at specific locations, the duration of the signals acquired by the sensor differs significantly. The front and back of the workpiece are determined by the duration of the signals. In particular, it can correctly identify changes in the workpiece's size within a certain range. Even if the workpiece's size changes beyond the set range, calibration can be easily completed by simply changing the preset values ​​within the controller.

[0019] The front and back recognition system of this technical solution has low cost and a lot of room for expansion; the typical application of ring-shaped workpieces is the skeleton of oil seals. Oil seals are low value-added products and come in a wide variety of sizes. Attached Figure Description

[0020] Figure 1 This is one of the overall structural schematic diagrams of the present invention.

[0021] Figure 2 This is the second schematic diagram of the overall structure of the present invention.

[0022] Figure 3 This is the third schematic diagram of the overall structure of the present invention.

[0023] Figure 4 This is a schematic diagram of the annular workpiece of the present invention with the reverse side facing upwards.

[0024] Figure 5 This is a schematic diagram of the annular workpiece of the present invention with its front side facing upwards.

[0025] Figure 6 This is one of the schematic diagrams of the probe sensing the reverse side of the annular workpiece according to the present invention.

[0026] Figure 7 This is one of the schematic diagrams of the probe of the present invention sensing the front of a ring-shaped workpiece.

[0027] Figure 8 This is the second schematic diagram of the probe sensing the reverse side of the annular workpiece according to the present invention.

[0028] Figure 9 This is the second schematic diagram of the probe sensing the front of the annular workpiece according to the present invention.

[0029] Figure 10 This is a schematic diagram of the signal transmitted through the probe to the reverse side of the annular workpiece according to the present invention.

[0030] Figure 11 This is a schematic diagram of the signal from the front of the annular workpiece passing through the probe head according to the present invention.

[0031] Figure 12 This is one of the schematic diagrams of another workpiece conveying mechanism used in this invention.

[0032] Figure 13 This is a second schematic diagram of another workpiece conveying mechanism used in this invention.

[0033] Figure 14 This is a schematic diagram of the reference plane for another workpiece conveying mechanism used in this invention. Detailed Implementation

[0034] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0035] Example 1, as Figure 1-11 As shown, a front and back recognition system for annular workpieces is applicable to annular workpieces 20 with flanges 202 on the outer or inner sides, comprising: A workpiece conveying mechanism is used to transport a ring-shaped workpiece to a set position along a set trajectory. The trajectory includes at least a straight section with a reference surface. The reference surface is in contact with the outer circular surface 203 of the ring-shaped workpiece during its movement, and the reference surface defines the movement trajectory of the ring-shaped workpiece. Specifically, the workpiece conveying mechanism includes a frame 10, which has a conveying channel 103 inside. The conveying channel 103 is the straight trajectory. The conveying channel is used to constrain the ring-shaped workpiece 20 to be inspected, so that the ring-shaped workpiece moves along the set trajectory. One side of the conveying channel is set as the reference surface 1031. In this embodiment, the width of the conveying channel 103 corresponds to the thickness of the ring-shaped workpiece 20. The conveying channel is used for vertical movement of the ring-shaped workpiece. The material is fed to a rolling feeder; therefore, the reference surface 1031 is essentially the bottom surface of the conveying channel 103. In this case, even if the size of the annular workpiece changes, it will naturally conform to the reference surface under the action of gravity. Moreover, the upper part of the conveying channel 103 is freely open, and the outer diameter of the annular workpiece is not limited. Generally, the identification system described herein is used in conjunction with a chain plate elevator during actual operation. The chain plate elevator feeds the annular workpiece into the conveying channel, and the continuously fed annular workpiece pushes the annular workpiece in the conveying channel. The conveying channel 103 can also be set with a certain inclination, with the feed end of the conveying channel being high and the discharge end being low, so that the annular workpiece can roll more smoothly in the conveying channel along the set direction.

[0036] A detection mechanism 50 is disposed on one side of the conveying channel 103. The detection mechanism 50 includes a sensor, the sensor's probe 501 facing the conveying channel, and the probe's detection area used to detect the annular plane of the annular workpiece. In this document, the annular plane refers to the front or back of the annular workpiece. In this embodiment, the sensor is a proximity sensor, a reflective photoelectric sensor, or a laser sensor. The proximity sensor is suitable for detecting metal parts, while the reflective photoelectric sensor and laser sensor are suitable for detecting both metal and non-metal parts. The distance d2 between the detection area and the reference surface is configured such that: the flange thickness d3 of the annular workpiece < distance d2 ≤ the annular width d1 of the annular workpiece. Within this range, one sensor can complete the measurement. Taking the annular workpiece with an outer flange as an example: if the distance d2 > the annular width d1 of the annular workpiece, when the front workpiece passes by, the sensor signal will also experience a break, and the signal duration will be truncated, leading to misjudgment. If the distance d2 ≤ the flange thickness d3 of the annular workpiece, then when the front and back workpieces pass by, the sensor signals are consistent and cannot be distinguished. The detection area 502 mentioned in this article refers to the area where a sensor signal is triggered when a ring-shaped workpiece enters. For the sensor, the detection area 502 is a cylindrical region extending from the probe head. The diameter of this cylindrical region is the same as that of the probe head, and the length of this cylindrical region is determined by the actual sensor parameters. Taking Panasonic's single-distance sensor GX-112MA as an example, the maximum working distance is 2mm ± 10%, and the corresponding length of the cylindrical region is 2mm ± 10% (the stable detection range of this sensor is 0mm to 1.6mm, and it works best within the range of 0mm to 1.6mm). In simple terms, the distance from the probe head to the plane where the reference surface is located can be equated to the distance d2 between the detection area and the reference surface. The controller is connected to the sensor and is configured to: output an identification signal based on the length of the sensor signal when a sensor signal is received; the controller displays the front or back side through the identification signal and controls the subsequent actions of the execution unit 40. The controller can be a programmable logic controller (PLC) or a microcontroller, etc. An actuating component 40 is used to reject or flip the annular workpiece 20. The actuating component 40 is located at the front of the conveying channel in the conveying direction and close to the probe head 501. The actuating component includes a cylinder 402 and a push rod 401. The cylinder pushes the push rod into or out of the conveying channel. When the push rod enters the conveying channel, it pushes the annular workpiece 20 away from the conveying channel. The push rod is mounted on the piston rod of the cylinder or the push rod and piston rod are integrally formed. When the workpiece is determined to be on the front side, the actuating component 40 drives the push rod 401 backward, allowing the front workpiece to enter the next process. When the workpiece is determined to be on the back side, the actuating component 40 does not move, the push rod 401 blocks the workpiece from flowing into the next process, and the on the back workpiece rolls down the feeding trough. As an alternative, the actuating component can also be a hydraulic cylinder with a push rod, a motor with a rotating paddle, or a blower.

[0037] A workpiece speed control device 30 is disposed on one side of the frame 10 and is used to control the annular workpiece 20 to pass through the probe at a set speed. The workpiece speed control device 30 includes a drive motor 301 and an actuating element 302. The actuating element is mounted on the motor shaft of the drive motor and is used to push the annular workpieces one by one. The workpiece speed control device is an optional component for more accurate detection. When a robotic arm is used to grip and feed a single workpiece, the workpiece speed control device is not required.

[0038] Preferably, the actuating element 302 is cross-shaped; the rotation plane of the actuating element is perpendicular to the reference plane 1031. At the start of each operation, the drive motor 301 rotates the actuating element (stopping cross) 1 / 4 turn (90°), causing the foremost annular workpiece to pass through the actuating element and enter the sensor's detectable area. The actuating element controls the orderly entry of the annular workpieces, and the drive motor, controlled by the controller, also assists in accurately identifying each annular workpiece. The drive motor can also be replaced with a 90-degree or 120-degree indexer (e.g., a cam divider). The actuating element can also be Y-shaped. Generally, a cross shape corresponds to a 90-degree indexing, and a Y shape corresponds to a 120-degree indexing.

[0039] Preferably, the annular workpiece 20 is an annular metal sheet, and the inner or outer edge of the metal sheet extends to one side to form a flange (i.e., a flange formed by stamping).

[0040] The working principle of this invention is as follows: When the annular workpiece rolls over the detectable area, the different orientations of the annular workpiece will cause the sensor to generate different detection signals. Both detection signals will appear, but the duration will vary greatly. Whether the annular part rolls over or moves across the sensor, it is essentially the same at a specific moment. The following explanation will take moving across as an example.

[0041] like Figure 6 As shown in Figures 8 and 10, the detected signal is disconnected when the annular workpiece is in the reverse position: The first trigger signal time t1 occurs when the flanged position a1 enters the detectable area, and is close to the sensor position, causing the sensor to output a detection signal; such as Figure 6 The state shown corresponds to time t1; The first stop signal time t2 occurs when the flipped edge position a2 leaves the detectable area and is far from the sensor position, which will cause the sensor to stop signal; When the second trigger signal is triggered at time t3, the flange position a3 enters the detectable area and is close to the sensor position, which will cause the sensor to output a detection signal. The second stop signal occurs at time t4. When the flipped edge position a4 leaves the detectable area, it is far from the sensor position, which will cause the sensor to stop. like Figure 7 As shown in Figures 9 and 11, when the annular workpiece is in the front position, the detected signal is continuous: The first trigger signal occurs at time t1. When the main body b1 of the annular workpiece enters the detectable area, it is close to the sensor, causing the sensor to output a detection signal; for example... Figure 7 The state shown corresponds to time t1; The first stop signal occurs at time t4. When the main body of the ring-shaped workpiece b4 leaves the detectable area, it is far from the sensor position, which will cause the sensor to stop signal. By comparing the time characteristics of the sensor output signals when the workpiece passes through from the front and back, when the workpiece passes through from the front, the sensor outputs a continuous signal (assuming a value of 100 time units); when the workpiece passes through from the back, the sensor outputs two short, discontinuous signals (assuming values ​​of 20 time units each). Through the programming of the programmable logic controller (PLC), the on (output) time of the sensor is counted. If the output time is greater than 50 time units, the workpiece is determined to be from the front; if the output time is less than 50 time units, the workpiece is determined to be from the back.

[0042] Advantages of this design: When the outer diameter of the workpiece changes, there is no need to change the front and back recognition structure and features. For the same type of workpiece with an outer diameter of 100mm or 60mm, there is a difference in the connection signal between the front and back sensors, so there is no need to change the structure and features, making it highly versatile. Similarly, when the sensor position is fixed, the distance d2 between the detection area and the reference surface is also a fixed value. In this case, for ring-shaped workpieces of different specifications, as long as the flange thickness d3 and the ring width d1 of the ring workpiece meet the conditions, they can be directly applied to this system. For example, if the program is set to allow the sensor output time to be greater than 50 seconds, it can detect the passage of a workpiece from the front. If the program is set to allow the passage time to be less than 50 seconds, it can detect the passage of a workpiece from the back. The time difference between the front and back workpieces passing through the sensor is large and significant, and the programmable processor can accurately compare them, thus ensuring high accuracy in front / back recognition. Even if fine-tuning is required, it is only necessary to reset the preset values ​​through the controller to recognize front and back, providing high flexibility.

[0043] <Modification>: As a variation, the annular workpiece 20 can also be transported laterally. In this case, the width of the conveying channel 103 needs to be set to be greater than or equal to the width of the annular workpiece 20 when it is placed laterally (assuming that after the equipment is finalized, it can only accommodate smaller annular workpieces and not larger ones). In this case, the reference surface 1031 is the side wall of the conveying channel; that is, it needs to be ensured that the annular workpiece passes through the detectable area while adhering to the side wall of the conveying channel. In this solution, the bottom surface of the conveying channel can be slightly tilted towards the side reference surface at 5~10° to ensure that the annular workpiece adheres to the reference surface. Alternatively, a tension belt assembly can be provided on the other side to ensure that the annular workpiece adheres to the reference surface.

[0044] The transverse transport of the annular workpiece 20 can be achieved using a conveyor belt structure; the conveyor belt is located at the bottom of the conveying channel and on the side of the conveying channel (the conveyor belt is positioned opposite to the reference plane); the moving power can be provided by the conveyor belt under the conveying channel or by the conveying power provided by the conveyor belt on the side of the conveying channel.

[0045] The transverse transport of the annular workpiece 20 can also be carried out by a pusher cylinder. For example, if the conveying channel is provided with a right-angle area, the pusher cylinder is located at the right angle and pushes one annular workpiece forward each time.

[0046] Example 2, this embodiment is as follows Figure 12-14 As shown, the workpiece conveying mechanism includes a fixed base 90, a slide table 60, a slide table drive device (e.g., a cylinder direct drive or a servo motor driving a ball screw component) and a robot arm 70; the slide table 60 slides within the fixed base 90, and the slide table drive device drives the slide table; the robot arm 70 is provided on the slide table, and the robot arm 70 is used to grip or release the annular workpiece 20.

[0047] In this embodiment, the annular workpieces 20 are stacked in the storage bin 80. A robotic arm moves to the storage bin to grasp each workpiece individually and moves it to a designated position. The robotic arm transports the annular workpieces to the designated position along a predetermined trajectory. This trajectory includes at least a straight section with a reference surface 901. The reference surface is in contact with the outer circular surface 203 of the annular workpiece during its movement. During the movement, the workpiece passes through a detection mechanism 50. The detection mechanism identifies the front and back of the annular workpiece. If the identification fails, the robotic arm is released midway, allowing the annular workpiece to fall into a recycling bin (not shown). Relatively speaking, the workpiece conveying mechanism in this embodiment is less efficient than in Embodiment 1. When the workpiece size changes, the position of the robotic arm and the gripping structure also need to be adjusted. In this embodiment, the reference surface 901 is tangent to the outer circular surface 203 of the annular workpiece and parallel to the straight trajectory.

[0048] This application also claims protection for a method for identifying the front and back of a ring-shaped workpiece, wherein the ring-shaped workpiece is a ring-shaped sheet 201, and the outer or inner side of the metal sheet extends to one side to form a flange 202. The method includes the following steps: (1) Construct a trajectory for conveying the annular workpiece; the trajectory includes a straight line trajectory; set a reference surface according to the straight line trajectory; the annular workpiece is attached to the reference surface 1031; (2) A sensor is used to detect the passing ring-shaped workpiece; the sensor is oriented toward the ring plane of the ring-shaped workpiece; the distance d2 between the detection area and the reference plane is configured such that the flange thickness d3 of the ring-shaped workpiece is less than the distance d2 and the ring width d1 of the ring-shaped workpiece. (3) The sensor transmits the detected signal to the controller; the controller records the signal duration T of the sensor and compares the signal duration T with a preset value; when the signal duration T ≥ the preset value, the annular workpiece is identified as the front side; when the signal duration < the preset value, the annular workpiece is identified as the back side.

[0049] The width of the conveying channel corresponds to the thickness of the annular workpiece; the annular workpiece rolls or translates past the sensor. In step (1), the annular workpiece is controlled by a workpiece speed control device to pass through the probe head one by one at a set speed.

[0050] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A front and back identification system for a ring-shaped workpiece, applicable to a ring-shaped workpiece (20) with a flange (202) on its outer or inner side, characterized in that, include: workpiece A conveying mechanism is used to transport the annular workpiece to a set position along a set trajectory; the trajectory includes at least a straight track, and the straight track is provided with a reference surface; the reference surface is in contact with the outer circular surface (203) of the annular workpiece during its movement. The detection mechanism (50) includes a sensor; the sensor's probe (501) faces the straight trajectory, and the probe's detection area is used to detect the annular plane of the annular workpiece; the distance d2 between the detection area and the reference surface is configured such that the flange thickness d3 of the annular workpiece < the distance d2 ≤ the annular width d1 of the annular workpiece. The controller is connected to the sensor and is configured to output an identification signal based on the length of the sensor signal when a sensor signal is received.

2. The front and back recognition system for a ring-shaped workpiece according to claim 1, characterized in that, The workpiece conveying mechanism includes a fixed base, a slide table, a slide table drive device, and a robot arm; the slide table slides within the fixed base, and the slide table drive device drives the slide table; a robot arm is provided on the slide table, and the robot arm is used to grip or release the annular workpiece.

3. The front and back recognition system for a ring-shaped workpiece according to claim 1, characterized in that, The workpiece conveying mechanism includes a frame (10) and a conveying channel (103) is provided inside the frame (10); the conveying channel is used to constrain the annular workpiece (20) to be inspected, so that the annular workpiece moves along a set trajectory; one side of the conveying channel forms the reference surface (1031).

4. The front and back recognition system for a ring-shaped workpiece according to claim 3, characterized in that, The width of the conveying channel (103) corresponds to the thickness of the annular workpiece (20); the conveying channel is used for vertical rolling feeding of the annular workpiece; the bottom surface of the conveying channel forms the reference surface (1031).

5. The front and back recognition system for a ring-shaped workpiece according to claim 4, characterized in that, The conveying channel (103) is inclined at a certain angle, with the feed end of the conveying channel being high and the discharge end being low.

6. A front and back identification system for a ring-shaped workpiece according to any one of claims 1, 3-5, characterized in that, Also includes: A workpiece speed control device (30) is provided on one side of the frame (10) and is used to control the annular workpiece (20) to pass through the probe at a set speed.

7. The front and back recognition system for a ring-shaped workpiece according to claim 6, characterized in that, The workpiece speed control device (30) includes a drive motor (301) or an indexer, which drives a pusher (302); the pusher (302) is used to push the annular workpiece one by one; the pusher (302) is cross-shaped or Y-shaped; the rotation plane of the pusher is perpendicular to the reference plane (1031).

8. The front and back recognition system for a ring-shaped workpiece according to claim 3, characterized in that, It also includes an execution component (40); the execution component (40) is used to remove or flip the annular workpiece (20); the execution component (40) is disposed on the front side of the conveying direction of the conveying channel; The actuator includes a cylinder (402) and a push rod (401). The cylinder pushes the push rod into or out of the conveying channel. When the push rod enters the conveying channel, it pushes the annular workpiece (20) away from the conveying channel. The push rod is mounted on the piston rod of the cylinder or the push rod is integrally formed with the piston rod.

9. A method for identifying the front and back of a ring-shaped workpiece, applicable to ring-shaped workpieces (20) with flanges (202) on the outer or inner sides, characterized in that, The method includes the following steps: (1) The annular workpiece is moved on the reference surface at a set speed, and the outer circular surface (203) of the annular workpiece is in contact with the reference surface; (2) A sensor is used to detect the annular plane of the annular workpiece; the distance d2 between the sensor's detection area and the reference surface is configured such that: the flange thickness d3 of the annular workpiece < the distance d2 ≤ the annular width d1 of the annular workpiece; (3) The sensor transmits the detected signal to the controller; the controller records the signal duration T of the sensor and compares the signal duration T with a preset value; when the signal duration T ≥ the preset value, the annular workpiece is identified as the front side; when the signal duration < the preset value, the annular workpiece is identified as the back side.

10. The method for identifying the front and back of a ring-shaped workpiece according to claim 9, characterized in that, The width of the reference surface corresponds to the thickness of the annular workpiece; the annular workpiece rolls or translates past the sensor.

Images