A magnetic pre-positioning and anti-deviation combined assembly guide mechanism

Abstract

This invention provides a magnetically attracted pre-positioning and anti-deviation combined assembly guide mechanism, belonging to the technical field of rotary drilling cutter assembly tooling. It includes a split upper guide sleeve and a lower guide sleeve, which are assembled to form a guide assembly. A quick-change mounting base is mounted on the outside of the guide assembly, and the guide assembly is connected to a transmission link and guide groove drive component. The contact surface between the upper and lower guide sleeves is the guide sleeve opening and closing mating surface, with clearance bevels formed at both ends. When the upper and lower guide sleeves are closed, they together enclose a through-hole in the center of the guide sleeve assembly. When separated, a radial clearance gap is formed in the middle. This invention, using the aforementioned magnetically attracted pre-positioning and anti-deviation combined assembly guide mechanism, solves the problems of snap ring material displacement, alignment deviation, press-fitting skew, and workpiece surface scratches during the assembly of existing cutter cutter snap rings.

Description

Technical Field

[0001] This invention relates to the field of rotary drilling cutter assembly tooling technology, and in particular to a magnetic pre-positioning and anti-deviation combined assembly guide mechanism. Background Technology

[0002] As a core wear component of rotary drilling rigs, the rotary cutting pick relies on a C-type retaining spring to engage with the slot in the pick shank to achieve locking and positioning between the pick and the tooth seat. The assembly accuracy of the retaining spring directly determines the stability of the pick in subsequent use. In traditional assembly methods, manual assembly lacks a dedicated guiding and constraint structure, relying solely on visual inspection to align the retaining spring with the pick slot. The inconsistent force and alignment angle during manual operation easily lead to defects such as retaining spring misalignment, incomplete assembly, and retaining spring deformation and breakage. Existing semi-automatic assembly equipment is only equipped with a simple straight-tube guide cylinder, lacking a pre-positioning and correction structure. The retaining spring lacks effective limiting during transport, making it prone to lateral displacement and detachment after material handling. Furthermore, the guide cylinder lacks an internal gradient expansion structure, making it easy to scratch the outer wall of the pick shank when the retaining spring is forcibly pressed in. In addition, the lack of a magnetic fixing structure means that the retaining spring lacks stable constraint at the transport and docking stations, making it prone to radial displacement under pressure.

[0003] Conventional guide structures only have a single through hole and lack segmented, gradually expanding guide channels. The retaining spring experiences uneven force during press-fitting from the outside in, making it prone to unilateral tilting. Furthermore, the guide structure has poor compatibility with the cutting teeth; replacing different tooth specifications requires replacing the entire guide component, resulting in a long adjustment period. The inner wall of traditional guide components is a hard, straight metal surface, which easily causes scratches during retaining spring sliding and press-fitting, affecting the appearance and corrosion resistance of the finished cutting teeth. Additionally, existing guide structures lack an opening and closing clearance mechanism; after press-fitting, there is no radial separation gap between the guide sleeve and the cutting tooth shank, making it easy for the already assembled retaining spring to scrape against the material during discharge, causing assembly failure. Summary of the Invention

[0004] The purpose of this invention is to provide a magnetic pre-positioning and anti-offset assembly guide mechanism, which solves the problems of snap ring material offset, alignment deviation, press-fit skew, and workpiece surface scratches during the assembly of existing tooth snap rings.

[0005] To achieve the above objectives, the present invention provides a magnetic pre-positioning and anti-deviation combined assembly guide mechanism, comprising an upper half guide sleeve and a lower half guide sleeve that are separately coupled together. The upper half guide sleeve and the lower half guide sleeve are assembled together to form a guide assembly. A quick-change mounting base is mounted on the outside of the guide assembly. The guide assembly is connected to a transmission connecting rod guide groove drive assembly. The contact surface between the upper half guide sleeve and the lower half guide sleeve is the guide sleeve opening and closing mating surface. The two ends of the guide sleeve opening and closing mating surface are formed with opening and closing mating surface clearance bevels. After the upper half guide sleeve and the lower half guide sleeve are closed, they together enclose a through guide sleeve central assembly through hole. After the two are separated, a radial clearance gap is formed in the middle after tooling separation.

[0006] Preferably, the guide sleeve has a central assembly through hole that is sequentially formed along the axial direction with an expansion groove large-diameter press-fit guide section, a gradually changing arc expansion section, and an expansion groove small-diameter inlet end, with the three sections forming a smooth and continuous transition.

[0007] Preferably, both the upper and lower guide sleeves have embedded mounting grooves for permanent magnet blocks on their inner walls. Arc-shaped permanent magnet positioning blocks are fixedly assembled in the embedded mounting grooves. The inner side of the arc-shaped permanent magnet positioning blocks is formed with the outer ring of the retaining spring for adsorption and contact. Multiple arc-shaped permanent magnet positioning blocks are evenly arranged circumferentially along the central mounting through hole of the guide sleeve. The arc-shaped permanent magnet positioning blocks are completely embedded in the embedded mounting grooves of the permanent magnet blocks and do not extend into the central mounting through hole of the guide sleeve.

[0008] Preferably, the inner wall of the guide sleeve is hot-pressed to fit a flexible anti-scratch protective layer on the inner wall of the guide sleeve through hole at the center, and the flexible anti-scratch protective layer on the inner wall of the guide sleeve can be removed separately.

[0009] Preferably, the lower end of the guide assembly is integrally provided with an axial positioning end face for the guide sleeve.

[0010] Preferably, the connecting rod guide groove drive assembly is equipped with a drive cylinder, and the connecting rod guide groove drive assembly is connected to the guide assembly for transmission.

[0011] Preferably, the guiding mechanism is driven by the production line cylinder-driven connecting rod guide groove drive assembly to achieve D-shaped compound motion. It first moves laterally to receive the C-type snap ring, and then lifts axially to complete the magnetic pre-positioning before being transferred to the cutting tooth pre-assembly station, where it cooperates with the pressing actuator to complete the snap ring pressing.

[0012] Therefore, the present invention employs the above-mentioned magnetic attraction pre-positioning and anti-deviation combined assembly guide mechanism, and the technical effects are as follows: 1. Relying on magnetic pre-positioning combined with a D-type composite trajectory guide structure, the circlip material picks up and transfers material simultaneously to complete lateral correction and limiting. With the help of tooling elastic limiting and fixing cutting teeth, it solves the problems of circlip skewing and circlip slot misalignment caused by the lack of a guide structure in traditional assembly.

[0013] 2. The guiding mechanism can automatically adjust the posture of the cutting teeth and stably support the snap ring, eliminating the need for manual adjustment of the workpiece position and removing workpieces with abnormal posture; in conjunction with the fully automated feeding, sorting, pressing and unloading operation, it eliminates the need for manual alignment and transfer processes, gets rid of the capacity limitations caused by manual operation, and continuously improves the efficiency of batch assembly.

[0014] 3. The guide positioning fixture adopts a quick-change structure, and the change of cutting tooth specifications can be completed in a short time. The guide rail width is adjustable and can be adapted to various models of cutting teeth. Attached Figure Description

[0015] Figure 1 This is a schematic cross-sectional view of the overall structure of the magnetic pre-positioning and anti-deviation combined assembly guide mechanism of the present invention; Figure 2This is a partially enlarged view of the magnetic pre-positioning component on the inner wall of the guide sleeve of the present invention; Figure 3 This is a schematic diagram of the gradient buffer expansion groove structure of the present invention; Figure 4 This is a schematic diagram of the tooling separation clearance structure of the present invention.

[0016] Figure Labels 1. Upper guide sleeve; 2. Lower guide sleeve; 3. Guide sleeve opening and closing mating surface; 4. Opening and closing mating surface clearance angle; 5. Cutting tooth shank; 6. Cutting tooth groove; 7. C-type retaining ring; 8. Guide sleeve axial positioning end face; 9. Guide sleeve center assembly through hole; 10. Arc-shaped permanent magnet positioning block; 11. Permanent magnet block embedded mounting groove; 12. Flexible anti-scratch protective layer on the inner wall of the guide sleeve; 13. Small diameter inlet end of the expansion groove; 14. Gradient arc expansion section; 15. Large diameter press-fit guide section of the expansion groove; 16. Radial clearance after tooling separation; 17. Retaining ring outer ring adsorption and contact surface. Detailed Implementation

[0017] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0019] Example 1 like Figures 1-4 As shown, this invention provides a magnetic pre-positioning and anti-deviation combined assembly guide mechanism. This guide mechanism consists of an upper guide sleeve 1 and a lower guide sleeve 2 that fit together to form a split guide assembly. The contact surface where the upper guide sleeve 1 and the lower guide sleeve 2 fit together is the guide sleeve opening and closing mating surface 3. An opening and closing mating surface clearance angle 4 is machined at both ends of the opening and closing mating surface to ensure no rigid interference during the opening and closing movement of the upper and lower guide sleeves. After the upper guide sleeve 1 and the lower guide sleeve 2 fit together, a through guide sleeve central assembly through hole 9 is formed inside. The guide sleeve central assembly through hole 9 is segmented along the axial direction into a small-diameter expansion groove inlet end 13, a gradually changing arc expansion section 14, and a large-diameter expansion groove press-fit guide section 15. The three sections transition smoothly and continuously, forming a dedicated gradually changing guide channel for snap ring press-fitting.

[0020] Both the upper guide sleeve 1 and the lower guide sleeve 2 have embedded permanent magnet mounting grooves 11 on their inner walls. Arc-shaped permanent magnet positioning blocks 10 are fixedly installed within these grooves. An arc-shaped outer ring of the retaining spring is formed on the inner side of each arc-shaped permanent magnet positioning block 10 for adsorption and contact. Multiple sets of arc-shaped permanent magnet positioning blocks 10 are evenly arranged circumferentially along the central mounting through hole, forming a ring-shaped magnetic positioning area. A flexible anti-scratch protective layer 12 is attached to the entire inner wall surface of the central mounting through hole 9 of the guide sleeve. This flexible protective layer completely covers the magnetic positioning area and the gradually expanding channel area, preventing direct contact between the hard metal and the cutting teeth and retaining spring.

[0021] The lower end of the guide sleeve assembly is provided with an axial positioning end face 8, which abuts against and limits the end face of the cutting tooth shank 5. An annular cutting tooth groove 6 is opened on the outer wall of the cutting tooth shank 5. The C-type retaining spring 7 is guided and pressed into the cutting tooth groove 6 through the central assembly through hole 9 of the guide sleeve. After the upper and lower guide sleeves complete the pressing operation, they separate outwards, and a radial clearance gap 16 is formed between the upper half guide sleeve 1 and the lower half guide sleeve 2 after tooling separation. The entire guide sleeve can be smoothly lifted and removed along the axial direction of the cutting tooth shank 5 without touching the assembled C-type retaining spring 7.

[0022] The entire guiding mechanism is linked to the connecting rod guide groove drive assembly of the production line. Driven by the production line cylinder, it completes a "D"-shaped compound motion trajectory. First, it moves laterally to receive the C-type retaining spring 7, then it is axially lifted to complete the magnetic pre-positioning. Subsequently, it moves to the cutting tooth pre-assembly station and cooperates with the pressing actuator to complete the retaining spring pressing. The entire process is synchronously controlled by the PLC system for opening, closing, translation, and lifting actions. The arc-shaped permanent magnet positioning block 10 is fixed inside the permanent magnet block embedded mounting groove 11 by an embedded fastening method, without occupying the effective guiding space of the central through hole. The flexible anti-scratch protective layer 12 on the inner wall of the guide sleeve is attached to the inner surface of the guide sleeve by a hot-press bonding process. It can be disassembled and replaced separately, making maintenance convenient. The upper half guide sleeve 1 and the lower half guide sleeve 2 are equipped with quick-change mounting bases to adapt to different diameter cutting tooth shanks 5. When changing product specifications, the whole assembly can be quickly disassembled and assembled without recalibrating the guide alignment reference.

[0023] The upper guide sleeve 1 and the lower guide sleeve 2 are combined to form a complete closed guide cylinder. The split opening and closing structure can achieve radial clearance. After the press is completed, the tooling is separated to form a radial clearance gap 16, which avoids the guide sleeve scraping the retaining spring when it is removed. The split structure facilitates the disassembly and maintenance of the internal arc-shaped permanent magnet positioning block 10 and the flexible anti-scratch protective layer.

[0024] In the guide sleeve opening and closing mating surface 3 and the opening and closing mating surface clearance angle 4, the opening and closing mating surface ensures that the rear end faces of the upper and lower guide sleeves fit tightly together and maintains the roundness of the central assembly through hole; the clearance angle eliminates corner collision interference when the guide sleeve moves laterally and opens and closes, ensuring that the mechanism moves smoothly without jamming.

[0025] The axial positioning end face 8 of the guide sleeve serves as an axial limiting reference, fitting snugly against the end face of the cutting tooth shank 5 to precisely lock the axial relative position of the guide sleeve and the cutting tooth groove 6, preventing misalignment caused by the guide sleeve moving up and down during the pressing process. The through hole 9 in the center of the guide sleeve provides a passage for the transfer and pressing of the C-type retaining spring 7. The internal segmented gradually expanding structure achieves a smooth transition from the relaxed adsorption state to the precise closing and locking into the groove.

[0026] The arc-shaped permanent magnet positioning block 10, the permanent magnet embedded mounting groove 11, and the outer ring adsorption and bonding surface 17 of the snap ring work together. The arc-shaped permanent magnet positioning block 10 is embedded in the mounting groove, and the circumferential multi-point magnetic attraction forms a ring adsorption force field. The outer ring adsorption and bonding surface 17 of the snap ring completely adheres to the outer wall of the C-shaped snap ring. The snap ring is pre-positioned by magnetic force. During the transportation process, the radial position of the snap ring is continuously constrained, and the snap ring is prevented from shifting or falling off from the source.

[0027] The flexible anti-scratch protective layer 12 on the inner wall of the guide sleeve isolates the metal guide sleeve from the cutting tooth shank 5 and the C-type retaining spring. During the press-fitting and sliding process, it eliminates hard scratches, protects the integrity of the workpiece surface, and reduces the defect rate.

[0028] The expansion groove small diameter inlet end 13, the gradual arc expansion section 14, and the expansion groove large diameter press-fit guide section 15 form a three-section gradual channel that gradually converges the retaining spring. The large diameter section accommodates the retaining spring in a magnetically opened state, the arc section shrinks smoothly, and the small diameter end precisely constrains the outer diameter of the retaining spring, guiding the retaining spring to accurately align with the cutting tooth groove 6, avoiding unilateral force and skewing.

[0029] After the tooling is separated, the radial clearance 16 is the radial gap formed after the upper and lower guide sleeves are separated. When the guide sleeve is lifted and removed, it avoids the protruding part of the snap ring to prevent the finished snap ring from being scraped and popped out by the guide sleeve.

[0030] This mechanism relies on a split-type opening and closing guide structure combined with a ring magnetic pre-positioning system, and combined with a segmented gradually expanding guide channel to achieve automatic material picking, magnetic correction, precise alignment, non-damaging pressing, and interference-free removal of C-type snap rings throughout the entire process of guidance and constraint. The complete working process is divided into four stages: snap ring material picking and magnetic pre-positioning, station transfer and docking, graded guidance and pressing, and guide sleeve separation and removal.

[0031] The first stage is the magnetic pre-positioning of the snap ring. The production line drive assembly moves the guide sleeve assembly laterally along the guide groove. The large-diameter press-fit guide section 15 of the expansion groove of the through hole 9 in the center of the guide sleeve is aligned with the end of the snap ring distribution slide. The C-shaped snap ring 7 slides into the large-diameter area inside the guide sleeve. The circumferentially evenly arranged arc-shaped permanent magnet positioning blocks 10 simultaneously attract the outer ring of the snap ring through the snap ring's outer ring adsorption contact surface 17. The multi-point magnetic constraint makes the snap ring automatically center and correct, completely eliminating the snap ring's lateral offset and tilting problems, and completing the magnetic pre-positioning without manual intervention. The flexible anti-scratch protective layer 12 on the inner wall of the guide sleeve wraps around the outer wall of the snap ring to avoid scratches caused by metal contact. At this time, the upper half of the guide sleeve 1 and the lower half of the guide sleeve 2 are completely closed, and the opening and closing mating surfaces 3 of the guide sleeves are tightly fitted. The opening and closing mating surfaces give way to the oblique angle 4 to avoid collision with the side wall of the slide during lateral movement. The snap ring is stably constrained inside the guide channel, and there will be no failure of transfer and falling off.

[0032] The second stage involves composite trajectory transport and cutting tooth alignment. A linkage mechanism drives the guide sleeve to complete a "D"-shaped composite motion, first axially lifting and then laterally returning to its original position, transporting the guide sleeve assembly with the snap ring to the cutting tooth pre-assembly station. The cutting tooth body is aligned to an upward-facing position by a pre-positioned attitude adjustment mechanism, and the clamping cylinder fixes the cutting tooth shank 5. The axial positioning end face 8 of the guide sleeve falls against the upper end face of the cutting tooth shank 5, locking the axial height of the guide sleeve and the cutting tooth groove 6. This ensures precise coaxiality between the small-diameter inlet end 13 of the expansion groove and the cutting tooth groove 6, completing the pre-assembly benchmark alignment without the need for manual fine-tuning.

[0033] The third stage involves precise press-fitting with tiered guidance. The upper press-fitting head feeds downwards, pushing the C-shaped retaining ring 7 downwards along the central assembly through-hole 9 of the guide sleeve. The retaining ring first passes through the large-diameter press-fitting guide section 15 of the expansion groove to maintain a magnetically centered state, then smoothly enters the gradually curved expansion section 14. The curved surface slowly closes the outer diameter of the retaining ring, evenly distributing the press-fitting force and preventing unilateral deformation of the retaining ring. Finally, the retaining ring completes radial positioning through the small-diameter inlet end 13 of the expansion groove, precisely aligning with the tooth groove 6 on the outer wall of the cutting tooth shank 5. The press-fitting head continuously applies pressure to completely insert the C-shaped retaining ring 7 into the groove. A pressure sensor monitors the press-fitting load in real time, stopping the machine immediately in case of overload. Combined with a flexible anti-scratch protective layer, the outer wall of the cutting tooth and the surface of the retaining ring will not be scratched throughout the process.

[0034] The fourth stage involves the opening and closing of the guide sleeve and the unloading of the workpiece. After a single pressing operation, the drive mechanism causes the upper guide sleeve 1 and the lower guide sleeve 2 to separate along the opening and closing mating surface, forming a radial clearance gap 16 between them after tooling separation. The gap width is greater than the outer ring protrusion size of the C-type retaining spring 7 after assembly. Subsequently, the guide sleeve as a whole is lifted upward along the axial direction of the cutting tooth shank 5 and withdrawn. The separation gap avoids the inner wall of the guide sleeve from touching the assembled retaining spring, preventing the retaining spring from falling off or the assembly from failing. After the guide sleeve is reset, it moves laterally to the retaining spring slide again to carry out the next set of cutting tooth retaining spring guide assembly operations.

[0035] The entire guiding mechanism relies on a purely mechanical, split-type opening and closing structure combined with permanent magnet magnetic positioning to achieve all correction and guiding functions, eliminating the need for complex auxiliary positioning cylinders and reducing potential failure points. It comes with a quick-change mounting base; when changing to different specifications of cutting teeth, only the guide sleeve assembly with the corresponding inner diameter needs to be replaced, completing the specification switch within five minutes. This adapts to the flexible mass production of multiple models of rotary drilling cutting teeth. The entire mechanism is housed inside the equipment's dust cover, preventing dust from entering the central mounting through hole 9 of the guide sleeve and avoiding dust jamming that could cause misalignment of the retaining spring. Long-term continuous operation ensures stable and reliable guiding and positioning accuracy.

[0036] Therefore, the present invention employs the aforementioned magnetic pre-positioning and anti-deviation combined assembly guide mechanism, which consists of upper and lower guide sleeves joined together to form a complete guide cylinder. The mating area between the two sleeves is provided with an opening and closing mating surface and a clearance angle to eliminate motion interference. A segmented, gradually expanding central assembly through-hole is provided inside the cylinder. Multiple sets of arc-shaped permanent magnet positioning blocks are circumferentially embedded in the inner wall of the through-hole to form an annular magnetic adsorption area. The inner wall of the through-hole is fully covered with a flexible anti-scratch protective layer to prevent workpiece scratches. The lower end of the guide sleeve is provided with an axial positioning end face for locking with the cutting tooth shank and cutting tooth slot. The axial assembly reference is established, and the upper and lower guide sleeves can form a radial clearance after separation to facilitate the removal of the workpiece without interference. The entire guide assembly is equipped with a quick-change base to adapt to multiple specifications of cutting teeth. It achieves a D-shaped composite motion trajectory by relying on the connecting rod guide groove drive. It completes the pre-positioning and correction of the circlip transfer by relying on the built-in magnetic attraction structure. It achieves smooth circlip retraction and precise alignment with the slot press-fit by using the segmented gradual expansion channel. The whole system solves the problems of circlip assembly misalignment, scratches, and collisions during removal by the coordinated structure of multiple structures such as split opening and closing, magnetic pre-positioning, gradient guidance, and radial clearance.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A magnetic pre-positioning and anti-deviation assembly guide mechanism, characterized in that, It includes an upper half guide sleeve and a lower half guide sleeve that are set separately and fit together. The upper half guide sleeve and the lower half guide sleeve are assembled together to form a guide assembly. A quick-change mounting base is mounted on the outside of the guide assembly. The guide assembly is connected to a transmission connecting rod guide groove drive assembly. The contact surface between the upper half guide sleeve and the lower half guide sleeve is the guide sleeve opening and closing mating surface. The two ends of the guide sleeve opening and closing mating surface are formed with opening and closing mating surface clearance bevels. After the upper half guide sleeve and the lower half guide sleeve are closed, they together enclose to form a through guide sleeve central assembly through hole. After the two are separated, a radial clearance gap is formed in the middle after tooling separation.

2. The magnetic pre-positioning and anti-deviation combined assembly guide mechanism according to claim 1, characterized in that, The guide sleeve is assembled with a through hole at the center, and the expansion groove, the large diameter press-fit guide section, the gradually changing arc expansion section, and the small diameter inlet end of the expansion groove are formed sequentially along the axial direction. The three sections are smoothly and continuously transitioned.

3. The magnetic pre-positioning and anti-deviation assembly guide mechanism according to claim 1, characterized in that, Both the upper and lower guide sleeves have embedded mounting slots for permanent magnet blocks on their inner walls. Arc-shaped permanent magnet positioning blocks are fixedly assembled in the embedded mounting slots. The inner side of the arc-shaped permanent magnet positioning blocks is formed with the outer ring of the retaining spring for adsorption and contact. Multiple arc-shaped permanent magnet positioning blocks are evenly arranged around the central mounting through hole of the guide sleeve. The arc-shaped permanent magnet positioning blocks are completely embedded in the embedded mounting slots of the permanent magnet blocks and do not extend into the central mounting through hole of the guide sleeve.

4. The magnetic pre-positioning and anti-deviation combined assembly guide mechanism according to claim 1, characterized in that, The guide sleeve is assembled with a through hole in the center, and the inner wall of the guide sleeve is hot-pressed to form a flexible anti-scratch protective layer. The flexible anti-scratch protective layer of the guide sleeve can be removed separately.

5. The magnetic pre-positioning and anti-deviation combined assembly guide mechanism according to claim 1, characterized in that, The guide sleeve axial positioning end face is integrally set at the lower end of the guide assembly.

6. The magnetic pre-positioning and anti-deviation combined assembly guide mechanism according to claim 1, characterized in that, The connecting rod guide groove drive assembly is equipped with a drive cylinder, and the connecting rod guide groove drive assembly is connected to the guide assembly for transmission.

7. The magnetic pre-positioning and anti-deviation combined assembly guide mechanism according to claim 1, characterized in that, The guiding mechanism is driven by the production line cylinder-driven connecting rod guide groove drive assembly to achieve D-type compound motion. It first moves laterally to receive the C-type snap ring, and then lifts axially to complete the magnetic pre-positioning before being transferred to the cutting tooth pre-assembly station, where it cooperates with the pressing actuator to complete the snap ring pressing.

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