Shaft screening device and screening method

Abstract

The invention belongs to the technical field of shaft workpiece screening, and particularly relates to a shaft screening device and method.The device comprises a feeding device, a screening device body, a workbench and a controller, the screening device body is provided with a screening unit, a driving unit and a position detection unit, and the screening unit comprises a moving part and a fixed part; the driving unit is configured to control the matching position of the movable part and the fixed part, the position detection unit is used for detecting the action state of the driving unit, and the controller is electrically connected with the driving unit, the position detection unit and the power module through wires. The method comprises the steps that by controlling the driving unit, the driving unit can adjust the relative position of the moving part and the fixed part, and then screening of different types of shafts is achieved. The position detection unit is used for accurately detecting the matching position of the movable part and the fixed part, and it is ensured that the screening procedure is normally carried out. The device is low in manufacturing cost and low in false detection rate, can be fully integrated with a production line, and improves the production efficiency and the error-tolerant rate.

Description

Technical Field

[0001] The present invention belongs to the technical field of shaft workpiece screening, and particularly relates to a shaft screening device and a screening method. Background Art

[0002] Shaft workpieces are common parts in the field of mechanical manufacturing. Especially in the field of chain preparation, the quality of shaft parts (pin shafts) is directly related to the overall quality of the chain. Therefore, it is necessary to screen shaft workpieces before assembly to remove unqualified products and allow qualified products to enter the assembly process.

[0003] Existing shaft screening mainly relies on manual labor and vibrating bowls to pass materials through different specifications of sieves for screening. Manual screening has low efficiency, a large labor volume, and is affected by subjective factors. The vibrating sieves used on site are mainly used to screen shaft parts and sundries with obvious differences, and it is difficult to distinguish shaft workpieces with small differences. Currently, there are relatively professional shaft screening devices on the market, such as image screening, but such devices have high manufacturing costs, a high probability of misidentification, and require a separate screening process to complete. Summary of the Invention

[0004] The present invention discloses a shaft screening device and a screening method, aiming to solve the problem of shaft material mixing during the production process. The screening of materials is achieved through the limiting characteristics of the mechanical structure, and it can be connected in series and in parallel with the existing production line to improve the on-site production efficiency, increase the error tolerance rate, and reduce the downtime rate and equipment damage rate caused by material problems on site.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A shaft screening device includes a feeding device, a main body of the screening device, a workbench, and a controller. The main body of the screening device is provided at the top of the workbench. The top of the main body of the screening device is connected to the feeding device through a blanking pipe. A collection box is provided below the workbench. The collection box includes a qualified product collection box and an unqualified product collection box. The main body of the screening device is respectively connected to the qualified product collection box and the unqualified product collection box through a material channel. The main body of the screening device is provided with a screening unit, a driving unit, and a position detection unit. The screening unit includes a moving part and a fixed part. The driving unit is configured to control the cooperation position of the moving part and the fixed part. The position detection unit is used to detect the action state of the driving unit. The controller is respectively electrically connected to the driving unit, the position detection unit, and the power supply module through wires.

[0007] Preferably, the feeding device includes a vibrating bowl. The vibrating bowl is connected to the top of the blanking pipe through a discharge guide rail. The bottom of the blanking pipe is connected to the top of the main body of the screening device. An observation window is provided on the side wall of the blanking pipe.

[0008] Preferably, the fixed part includes a fixed blanking seat and a U-shaped limiting seat, and the movable part includes a slider blanking seat. A semicircular stepped hole is opened at the center of the top of the U-shaped limiting seat, the bottom of the blanking pipe is fixedly connected to the large-diameter hole section at the top of the stepped hole, the inner wall of the small hole section of the stepped hole constitutes a limiting structure, and the open end of the side of the stepped hole passes through the front surface of the top wall of the U-shaped limiting seat, a slider blanking seat is provided below the U-shaped limiting seat, and a fixed blanking seat is provided below the slider blanking seat, a guide hole is provided in the center of the slider blanking seat, and the fixed A blanking hole for unqualified shaft parts with small diameter is provided in the center of the fixed blanking seat, a blanking hole for shaft parts with excessive length is provided on the front side, and a blanking hole for qualified shaft parts is provided on the rear side. In the initial state, the blanking tube, the guide hole, and the blanking hole for unqualified shaft parts with small diameter are coaxially opposed to each other up and down to screen unqualified shaft parts with small diameter; shaft parts with satisfactory length move backward over the limiting structure under the drive of the blanking seat of the slider, and the qualified shaft parts are blanked when they are opposite to the blanking hole of the qualified shaft parts; shaft parts with a length greater than that of the qualified shaft parts move forward under the drive of the blanking seat of the slider to be opposite to the blanking hole of the shaft parts with excessive length, and the blanking of the shaft parts with excessive length is achieved.

[0009] Preferably, the screening device body also includes a base, the fixed blanking seat is fixedly installed on the rear part of the base, the blanking holes for small-diameter unqualified shaft parts, the blanking holes for over-length shaft parts, and the blanking holes for qualified shaft parts extend downward, and respectively pass through the base and the workbench, and are respectively connected to the top of the material channel, the unqualified product collection box includes a small-diameter unqualified shaft part collection box and an over-length shaft part collection box, and the tops of the small-diameter unqualified shaft part collection box and the over-length shaft part collection box are respectively connected to the bottom of the corresponding material channel.

[0010] Preferably, the driving unit includes a first cylinder and a second cylinder, the telescopic end of the first cylinder is fixedly connected to the middle of the front end of the slider blanking seat, the bottom of the slider blanking seat is slidably connected to the top of the fixed blanking seat, the bottom of the first cylinder is slidably connected to the middle of the base through the cylinder fixing seat, the second cylinder is fixedly connected to the front of the base, the telescopic end of the second cylinder is fixedly connected to the rear end center of the cylinder fixing seat, and in the initial state, the first cylinder is in the retraction device and the second cylinder is in the extension state.

[0011] Preferably, the base is a U-shaped plate-like structure, which is fixedly connected to the workbench. A controller is provided on one side of the workbench, and the controller is electrically connected to a human-machine interaction device. The two arms of the U-shaped limit seat are respectively connected to the two side walls of the base by bolts. A plurality of bolt holes are provided longitudinally on the two side walls of the base. The U-shaped limit seat adjusts the distance between the lower surface of its top and the top end of the slider fixing seat by connecting to different bolt holes. Pin holes are respectively provided at the tops of the two side walls of the base and at both sides of the top of the U-shaped limit seat, and the two pin holes on the same side are connected by a positioning pin.

[0012] Preferably, the position detection unit includes a first position sensor for detecting the position of the end of the piston rod of the first cylinder and a second position sensor for detecting the position of the end of the piston rod of the second cylinder; a photoelectric sensor is installed on the hole wall of the blanking hole for small-diameter unqualified shaft parts, and the photoelectric sensor is used to detect that the small-diameter unqualified shaft parts completely enter the blanking hole for small-diameter unqualified shaft parts.

[0013] Preferably, both the first cylinder and the second cylinder are magnet-attached cylinders, and both the first position sensor and the second position sensor are magnetic induction switches provided on the cylinder barrels of the first cylinder and the second cylinder.

[0014] A screening method for a shaft screening device includes the following steps:

[0015] Step 1: In the initial state, the shaft parts fall through the blanking pipe and the guiding hole. If this shaft part is a small-diameter unqualified shaft part, the shaft part falls through the blanking hole for small-diameter unqualified shaft parts, passes through the base and the workbench, and falls into the small-diameter unqualified shaft part collection box via the material channel; the controller judges that the small-diameter unqualified shaft part completely enters the blanking hole for small-diameter unqualified shaft parts according to the information of the photoelectric sensor. At this time, keep the first cylinder stationary; when there is no information feedback from the photoelectric sensor after the blanking of the blanking pipe starts for a set time, it is judged that the shaft part is not a small-diameter unqualified shaft part, and the controller starts the first cylinder to push the slider blanking seat backward by a set distance;

[0016] Step 2: If there is no obstacle when the first cylinder drives the slider blanking seat to move backward and it reaches the position, the shaft screening device enters the second state. At this time, the shaft part is opposite to the blanking hole for qualified shaft materials, and the qualified shaft parts pass through the blanking hole for qualified shaft materials, pass through the base and the workbench, and enter the qualified shaft part collection box via the material channel; if there is an obstacle when the first cylinder drives the slider blanking seat to move backward, at this time, it is judged that the length of the shaft part exceeds the standard, and the top end of the shaft part is stuck on the inner wall of the small hole section of the stepped hole at the top of the U-shaped limit seat. Within a set time period, the controller does not receive the information that the piston rod of the first cylinder moves backward to the in-place position detected by the position sensor or continuously detects the distance that the piston rod of the first cylinder stops at the stuck position. At this time, the controller starts the first cylinder to contract to the initial position, and then starts the second cylinder to move the cylinder fixing seat forward;

[0017] Step 3: The second cylinder drives the cylinder fixing seat to move forward by a distance. At this time, the shaft member is opposite to the blanking hole of the shaft member with excessive length. The shaft member passes through the blanking hole of the shaft member with excessive length, passes through the base and the workbench, and enters the collection box for shaft members with excessive length through the material channel.

[0018] Step 4: The controller starts the second cylinder to extend, so that the slider blanking seat returns to the initial position, and steps 1 to 4 are repeated to screen the shaft members.

[0019] The beneficial effects of an axial screening device and a screening method of the present invention are as follows:

[0020] 1. The present invention solves the problem of mixing of axial materials during the production process, realizes the screening of materials through the limiting characteristics of the mechanical structure, and can be connected in series and parallel with the existing production line, improving the on-site production efficiency, increasing the error tolerance rate, and reducing the downtime rate and equipment damage rate caused by material problems on site.

[0021] 2. Compared with commercially available products, the present invention adopts a pure mechanical screening mode, has the advantages of low manufacturing cost and low false screening rate, and can be fully integrated with the existing production line, without the need to set up a separate screening process outside the production line. Description of the Drawings

[0022] Figure 1 : Flow chart of the screening method of the present invention.

[0023] Figure 2 : Exploded structural schematic diagram of the main body of the screening device of the present invention.

[0024] Figure 3 : Overall structural schematic diagram of the present invention.

[0025] 1. First cylinder; 2. Second cylinder; 3. Blanking pipe; 4. U-shaped limiting seat; 5. Slider blanking seat; 51. Material guiding hole; 6. Cylinder fixing seat; 7. Base; 8. Fixed blanking seat; 81. Blanking hole for small-diameter unqualified shaft parts; 82. Blanking hole for qualified shaft parts; 83. Blanking hole for shaft parts with excessive length; 9. Positioning pin; 91. Pin hole; 10. Sensor; 11. Observation window; 12. Step hole; 13. Silo; 14. Vibrating screen; 15. Discharge guide rail; 16. Human-machine interaction device; 17. Workbench; 18. Material channel; 19. Collection box; 01. Main body of the screening device. Detailed Embodiments

[0026] The following description is only for the preferred embodiments of the present invention and is not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0027] The following embodiments can be understood as expressing a part of the local structure or method of the present invention alone, or can also be understood as the combination of embodiments explaining the connotation of the structure or method of a larger scope of the present invention.

[0028] Embodiment 1

[0029] A shaft screening device, as Figures 1 - 3 shown, includes a feeding device, a screening device main body 01, a workbench 17, and a controller. The screening device main body 01 is provided at the top of the workbench 17. The top of the screening device main body 01 is connected to the feeding device through a blanking pipe 3. A collection box 19 is provided below the workbench 17. The collection box 19 includes a qualified product collection box and a non-qualified product collection box. The screening device main body 01 is respectively connected to the qualified product collection box and the non-qualified product collection box through a material channel 18. The screening device main body is provided with a screening unit, a driving unit, and a position detection unit. The screening unit includes a moving part and a fixed part. The driving unit is configured to control the mating position of the moving part and the fixed part. The position detection unit is used to detect the action state of the driving unit. The controller is electrically connected to the driving unit, the position detection unit, and the power supply module through wires respectively.

[0030] In this embodiment, by controlling the driving unit, the driving unit can adjust the relative position of the moving part and the fixed part, thereby realizing the screening of different types of shaft parts, including shaft parts with unqualified outer diameters, shaft parts with unqualified lengths, and the screening of qualified shaft parts. The position detection unit is used to accurately detect the mating position of the moving part and the fixed part to ensure the normal progress of the screening process.

[0031] Embodiment 2

[0032] As Figure 3 shown, the feeding device includes a vibrating bowl. The vibrating bowl is connected to the top of the blanking pipe 3 through a discharge guide rail 15. The bottom of the blanking pipe 3 is connected to the top of the screening device main body. As Figure 2 shown, an observation window 11 is provided on the side wall of the blanking pipe 3.

[0033] In this embodiment, the vibrating bowl is a prior art. As Figure 3 shown, it generally includes a feed bin 13 and a vibrating screen 14. Under the vibration of the vibrating screen, the shaft parts rise along the spiral guide rail on the top of the vibrating bowl and are finally output from the discharge guide rail 15 through the limit of the guide rail. The vibrating bowl of the present invention can select commercially available products, and the content not described is solved by the prior art solution. An observation window is provided on the side wall of the blanking pipe 3, which is convenient for observing the blanking state of the shaft parts and timely discovering problems in blanking, such as blockage and empty feeding.

[0034] Embodiment 3

[0035] AsFigure 2 As shown, the fixed part includes a fixed blanking seat 8 and a U-shaped limiting seat 4, and the movable part includes a slider blanking seat 5. A semicircular stepped hole 12 is opened at the center of the top of the U-shaped limiting seat 4, and the bottom of the blanking tube 3 is fixedly connected to the large-diameter hole section at the upper part of the stepped hole 12. The inner wall of the small hole well section of the stepped hole 12 constitutes a limiting structure. The open end of the side of the stepped hole 12 passes through the front surface of the top wall of the U-shaped limiting seat. A slider blanking seat 5 is provided below the U-shaped limiting seat 4, and a fixed blanking seat 8 is provided below the slider blanking seat 5. A guide hole 51 is provided at the center of the slider blanking seat 5. A blanking hole 81 for unqualified shaft parts with small diameter is provided in the center of the fixed blanking seat 8, a blanking hole 83 for shaft parts with excessive length is provided on the front side, and a blanking hole 82 for qualified shaft parts is provided on the rear side. In the initial state, the blanking tube 3, the guide hole 51, and the blanking hole 81 for unqualified shaft parts with small diameter are coaxially opposed to each other up and down to screen unqualified shaft parts with small diameter; shaft parts with satisfactory length move backward over the limiting structure under the drive of the blanking seat 5 of the slider, and the qualified shaft parts are blanked when they are opposite to the blanking hole 82 for qualified shaft parts; shaft parts with a length greater than that of qualified shaft parts move forward under the drive of the blanking seat 5 of the slider to be opposite to the blanking hole 83 for shaft parts with excessive length, and the blanking of shaft parts with excessive length is achieved.

[0036] Example 4

[0037] like Figure 2 , Figure 3 As shown, the screening device body also includes a base 7, and the fixed blanking seat 8 is fixedly installed on the rear part of the base 7. The small-diameter unqualified shaft blanking hole 81, the over-length shaft blanking hole 83, and the qualified shaft blanking hole 82 extend downward, and respectively pass through the base 7 and the workbench 17 (that is, the base and the workbench are provided with coaxial holes with the same inner diameter), and are respectively connected to the top of the material channel 18. The unqualified product collection box includes a small-diameter unqualified shaft collection box and an over-length shaft collection box. The tops of the small-diameter unqualified shaft collection box and the over-length shaft collection box are respectively connected to the bottom of the corresponding material channel.

[0038] Example 5

[0039] like Figure 2 As shown, the driving unit includes a first cylinder 1 and a second cylinder 2. The telescopic end of the first cylinder 1 is fixedly connected to the middle of the front end of the slider blanking seat 5 to drive the slider blanking seat 5 to move forward and backward. The bottom of the slider blanking seat 5 is slidably connected to the top of the fixed blanking seat 8. The bottom of the first cylinder 1 is slidably connected to the middle of the base 7 through the cylinder fixing seat 6. The second cylinder 2 is fixedly connected to the front of the base 7. The telescopic end of the second cylinder 2 is fixedly connected to the rear end center of the cylinder fixing seat 6. In the initial state, the first cylinder 1 is in the retraction device and the second cylinder 2 is in the extension state.

[0040] Example 6

[0041] As Figure 2 、 3 shown, the base 7 is in a U-shaped plate structure, and the second cylinder 2, the cylinder fixing seat 6, and the fixed blanking seat 8 are all arranged inside the base; the base 7 is fixedly connected to the workbench 17, a controller is arranged on one side of the workbench 17, the controller is electrically connected to a human-computer interaction device 16, the two arms of the U-shaped limiting seat 4 are respectively connected to the two side walls of the base 7 by bolts, and a plurality of bolt holes (as Figure 2 shown, not marked in the figure) are arranged longitudinally on the two side walls of the base 7, and the U-shaped limiting seat 4 adjusts the distance F between the lower surface of its top and the top end of the slider fixing seat 5 by connecting with different bolt holes. Pin holes 91 are respectively arranged at the tops of the two side walls of the base 7 and at the two sides of the top of the U-shaped limiting seat 4, and the two pin holes 91 on the same side are connected by a positioning pin 9.

[0042] In this embodiment, for the length range of the length-exceeding shaft parts to be detected, the distance F can be adjusted. Generally, the length exceeding the qualified shaft part length + 0.1 mm is the length exceeding the standard. By adjusting the distance F, when the length-exceeding shaft part moves backward, it can be blocked and limited by the inner wall of the small-hole section of the stepped hole. Among them, the height of the inner wall of the small-hole section should match the height range of the top end of the length-exceeding shaft part.

[0043] Example 7

[0044] As Figure 2 shown, the position detection unit includes a first position sensor for detecting the position of the end of the piston rod of the first cylinder 1 and a second position sensor for detecting the position of the end of the piston rod of the second cylinder 2; a photoelectric sensor is installed on the hole wall of the blanking hole for small-diameter unqualified shaft parts, and the photoelectric sensor is used to detect that the small-diameter unqualified shaft parts completely enter the blanking hole for small-diameter unqualified shaft parts.

[0045] In this embodiment, the positions of the piston rods of the first and second cylinders can be detected by a variety of sensors, including a resistive displacement sensor (one end is connected to the cylinder barrel and the other end is connected to the end of the piston rod), and a photoelectric sensor (which can be arranged on the side wall of the base or on the top of the fixed blanking seat). The detection of the piston rod position can assist the controller to accurately control each blanking position.

[0046] Example 8

[0047] As Figure 2 shown, the first cylinder 1 and the second cylinder 2 are both magnet-attached cylinders, and the first position sensor and the second position sensor are both magnetic induction switches arranged on the cylinder barrels of the first cylinder and the second cylinder.

[0048] This embodiment provides a more convenient implementation method. By means of the cooperation between the magnet at the end of the piston rod of the magnet-attached cylinder and the magnetic induction switch on the cylinder barrel, the detection of the position of the end of the piston rod can be realized.

[0049] Embodiment 9

[0050] Based on the above embodiments, this embodiment discloses a screening method for a shaft screening device, as Figures 1 - 3 shown, including the following steps:

[0051] Step 1: In the initial state, the shaft parts (shaft pieces) fall through the blanking pipe 3 and the material guiding hole 51. If the shaft piece is a small-diameter unqualified shaft piece, the shaft piece falls through the small-diameter unqualified shaft piece blanking hole 81, passes through the base 7 and the workbench 17 and falls into the small-diameter unqualified shaft piece collection box via the material channel 18; the controller judges that the small-diameter unqualified shaft piece completely enters the small-diameter unqualified shaft piece blanking hole according to the information of the photoelectric sensor. At this time, the first cylinder is kept stationary; when there is no information feedback from the photoelectric sensor after the blanking of the blanking pipe starts for a set time, it is judged that the shaft piece is not a small-diameter unqualified shaft piece, and the controller starts the first cylinder to push the slider blanking seat 5 backward by a set distance; of course, if the photoelectric sensor is not set, after the machine is started, it can be observed through the observation window whether there is a shaft piece in the blanking pipe. If there is a shaft piece, it means that the shaft piece entering the material guiding hole through the blanking pipe is not a small-diameter unqualified shaft piece, and its diameter is larger than the aperture of the small-diameter unqualified shaft piece blanking hole and is propped above the fixed blanking seat; thus, the controller is started to perform the next action;

[0052] Step 2: If the first cylinder 1 drives the slider blanking seat 5 to move backward without obstruction and reaches the position, the shaft screening device enters the second state. At this time, the shaft piece is opposite to the qualified shaft material blanking hole 82, and the qualified shaft piece passes through the qualified shaft piece blanking hole 82, passes through the base 7 and the workbench 17 and enters the qualified shaft piece collection box via the material channel 18; when the first cylinder 1 drives the slider blanking seat 5 to move backward and is obstructed, at this time, it is judged that the length of the shaft piece exceeds the standard, and the top of the shaft piece is stuck on the inner wall of the small hole section of the top step hole of the U-shaped limit seat 4. Within a set time period, the controller does not receive the information that the piston rod of the first cylinder 1 moves backward to the in-place position detected by the position sensor or continuously detects the distance that the piston rod of the first cylinder 1 stops at the stuck position. At this time, the controller starts the first cylinder 1 to contract to the initial position, and then starts the second cylinder 2 to move the cylinder fixing seat 6 forward;

[0053] Step 3: The second cylinder 2 drives the cylinder fixing seat 6 to move forward by a set distance. At this time, the shaft piece is opposite to the length-exceeding-standard shaft piece blanking hole 83, and the shaft piece passes through the length-exceeding-standard shaft piece blanking hole 83, passes through the base 7 and the workbench 17 and enters the length-exceeding-standard shaft piece collection box via the material channel 18;

[0054] Step 4: The controller starts the second cylinder 2 to extend, so that the slider blanking seat 5 returns to the initial position, and steps 1 to 4 are repeated for shaft part screening.

Claims

1. A shaft screening device, characterized by: It includes a feeding device, a screening device body, a workbench, and a controller. The screening device body is provided on the top of the workbench, and the top of the screening device body is connected to the feeding device through a drop pipe. A collecting box is provided under the workbench, and the collecting box includes a qualified product collection box and a failed product collection box. The screening device body is connected to the qualified product collection box and the failed product collection box through a material channel, respectively. The screening device body is provided with a screening unit, a driving unit, and a position detection unit. The screening unit includes a moving part and a fixed part. The driving unit is configured to control the matching position of the moving part and the fixed part. The position detection unit is used to detect the action state of the driving unit. The controller is electrically connected to the driving unit, the position detection unit, and the power module through wires, respectively.

2. A shaft screening device as claimed in claim 1, characterized in that: The feeding device comprises a vibrating plate, the vibrating plate is connected to the top of the drop tube through a discharge guide rail, the bottom of the drop tube is connected to the top of the screening device body, and an observation window is arranged on the side wall of the drop tube.

3. A shaft screening device as claimed in claim 2, characterized in that: The fixed part includes a fixed blanking seat and a U-shaped limiting seat, and the movable part includes a slider blanking seat. A semicircular stepped hole is opened at the center of the top of the U-shaped limiting seat, and the bottom of the blanking pipe is fixedly connected to the large-diameter hole section at the upper part of the stepped hole. The inner wall of the small hole well section of the stepped hole constitutes a limiting structure, and the open end of the side of the stepped hole passes through the front surface of the top wall of the U-shaped limiting seat. A slider blanking seat is provided below the U-shaped limiting seat, and a fixed blanking seat is provided below the slider blanking seat. A guide hole is provided at the center of the slider blanking seat. A blanking hole for unqualified small-diameter shafts is provided in the center of the material seat, a blanking hole for shafts with excessive length is provided on the front side, and a blanking hole for qualified shafts is provided on the rear side. In the initial state, the blanking tube, the guide hole, and the blanking hole for unqualified small-diameter shafts are coaxially opposed to each other up and down to screen unqualified small-diameter shafts; shafts with satisfactory length move backward over the limiting structure under the drive of the slider blanking seat, and the qualified shafts are blanked when they are opposite to the blanking hole for qualified shafts; shafts with lengths greater than qualified shafts move forward under the drive of the slider blanking seat to be opposite to the blanking hole for shafts with excessive length, and the blanking of shafts with excessive length is achieved.

4. A shaft screening device as claimed in claim 3, characterized in that: The screening device body also includes a base, the fixed blanking seat is fixedly installed on the rear part of the base, the small diameter unqualified shaft blanking hole, the over-length shaft blanking hole, and the qualified shaft blanking hole extend downward, and respectively pass through the base and the workbench, and are respectively connected to the top of the material channel, the unqualified product collection box includes a small diameter unqualified shaft collection box and an over-length shaft collection box, and the tops of the small diameter unqualified shaft collection box and the over-length shaft collection box are respectively connected to the corresponding bottom of the material channel.

5. A shaft screening device as claimed in claim 4, characterized in that: The driving unit includes a first cylinder and a second cylinder. The telescopic end of the first cylinder is fixedly connected to the middle of the front end of the slider blanking seat, the bottom of the slider blanking seat is slidably connected to the top of the fixed blanking seat, the bottom of the first cylinder is slidably connected to the middle of the base through the cylinder fixing seat, the second cylinder is fixedly connected to the front of the base, the telescopic end of the second cylinder is fixedly connected to the rear end center of the cylinder fixing seat, and in the initial state, the first cylinder is in the retraction device and the second cylinder is in the extension state.

6. A shaft screening device as claimed in claim 5, characterized in that: The base is a U-shaped plate structure, the base is fixedly connected to the workbench, a controller is provided on one side of the workbench, the controller is electrically connected to the human-computer interaction device, the two arms of the U-shaped limit seat are respectively connected to the two side walls of the base by bolts, the two side walls of the base are provided with a plurality of bolt holes in the longitudinal direction, the U-shaped limit seat adjusts the distance between the lower surface of its top and the top of the slider fixing seat by connecting with different bolt holes, pin holes are respectively provided on the top of the two side walls of the base and on both sides of the top of the U-shaped limit seat, and the two pin holes on the same side are connected by positioning pins.

7. A shaft screening device as claimed in claim 6, characterized in that: The position detection unit includes a first position sensor for detecting the end position of the piston rod of the first cylinder and a second position sensor for detecting the end position of the piston rod of the second cylinder; a photoelectric sensor is installed on the wall of the small diameter unqualified shaft blanking hole, and the photoelectric sensor is used to detect whether the small diameter unqualified shaft has completely entered the small diameter unqualified shaft blanking hole.

8. A shaft screening device as claimed in claim 7, characterized in that: The first cylinder and the second cylinder are both cylinders with magnets, and the first position sensor and the second position sensor are both magnetic induction switches arranged on the cylinder barrels of the first cylinder and the second cylinder.

9. A screening method for a shaft screening device as claimed in claim 8, characterized in that: The steps include: Step 1. In the initial state, the shaft falls through the blanking tube and the guide hole. If the shaft is a small-diameter unqualified shaft, the shaft passes through the small-diameter unqualified shaft blanking hole, passes through the base and the workbench, and falls into the small-diameter unqualified shaft collection box through the material channel; the controller determines that the small-diameter unqualified shaft has completely entered the small-diameter unqualified shaft blanking hole based on the information of the photoelectric sensor, and at this time, the first cylinder is kept stationary; when the blanking tube starts to drop for a set time, and there is no information feedback from the photoelectric sensor, it is determined that the shaft is not a small-diameter unqualified shaft, and the controller starts the first cylinder to push the slider blanking seat to move backward a set distance; Step 2: If the first cylinder drives the slider to move backward without obstruction and the blanking seat is in place, the shaft screening device enters the second state. At this time, the shaft is opposite to the blanking hole of qualified shaft material, and the qualified shaft passes through the qualified shaft blanking hole, the base and the workbench and the material channel into the qualified shaft collection box; if the first cylinder drives the slider to move backward and is obstructed, at this time, it is judged that the length of the shaft exceeds the standard, and the top end of the shaft is stuck on the inner wall of the small hole section of the stepped hole at the top of the U-shaped limit seat. Within the set time period, the controller does not receive the information detected by the position sensor that the piston rod of the first cylinder has moved backward into place or continuously detects the distance at which the piston rod of the first cylinder stops at the stuck position. At this time, the controller starts the first cylinder to retract to the initial position, and then starts the second cylinder to move the cylinder fixing seat forward; Step 3: The second cylinder drives the cylinder fixing seat to move forward a set distance, at which time the shaft part is opposite to the blanking hole of the shaft part with excessive length, and the shaft part passes through the blanking hole of the shaft part with excessive length, passes through the base and the workbench, and enters the collection box for the shaft part with excessive length through the material channel; Step 4: The controller starts the extension of the second cylinder to return the slider blanking seat to the initial position, and repeats steps 1 to 4 to screen the shaft parts.

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