Plug multi-component collaborative full-automatic assembly and online detection production line and method

Abstract

A plug multi-component cooperative full-automatic assembly and online detection production line and method, the production line comprising a first assembly unit, a plurality of first arc blocks are arranged to splice a first seamless cylindrical outer wall surface, a first pushing sleeve pushes the outer peripheral sealing ring away from the plug shell while the arc blocks are kept in an expanded state; a second assembly unit, two symmetrically arranged second arc blocks are arranged to splice an end surface provided with a guide structure to guide seamless fitting to form a second seamless cylindrical outer wall surface, a pushing device and a driving mechanism are independent, and the slide rod sealing ring is pushed away from the slide rod while the arc blocks are kept in an expanded state; and a third assembly unit, a double-stage coaxial pressing head assembly and a gasket holding device are arranged, a center front guide shaft is first inserted into a shell cavity for centering and guiding and resisting spring counterforce, and a peripheral pressing-in cylinder subsequently pushes the gasket and the snap spring into the cavity simultaneously. The seamless cylindrical surface is expanded and the sealing ring is not contracted for demolding to eliminate assembly damage of the sealing ring, and the double-stage guide pressing-in overcomes the spring counterforce to cause the snap spring to be pressed and assembled to be inclined.

Description

Technical Field

[0001] This invention relates to the field of automated precision assembly technology, specifically to a fully automated production line and method for the collaborative assembly and online testing of multiple plug components. Background Technology

[0002] In fields such as server water cooling systems and industrial connectors, plugs, as critical fluid connection components, directly affect the sealing reliability and service life of the system due to their assembly quality. A typical plug product consists of a plug housing, slide bar, multiple sealing rings, springs, washers, and open retaining rings, requiring multiple precision assembly processes within a narrow hollow cavity to meet extremely high airtightness requirements. Traditional assembly processes typically employ a single-machine, step-by-step operation mode, where multiple independent machines separately complete processes such as housing loading, sealing ring assembly, slide bar pressing, and spring and retaining ring pressing, connected by manual labor or simple conveyor belts. This mode has the following prominent problems.

[0003] First, there is damage during the assembly of the sealing rings. Plug products typically contain two types of elastic sealing rings: an outer sealing ring located on the outer periphery of the housing and a slide sealing ring located on the slide rod. Currently, automated assembly commonly uses multi-lobed opening claws to open the sealing rings. These opening claws consist of several claw pieces distributed circumferentially. However, there are structural gaps between the claw pieces, leaving the sealing ring partially suspended at these gaps. This results in a non-circular profile during opening, and the contact between the claw pieces and the inner wall of the sealing ring is line contact or even point contact. This concentrated stress easily leads to twisting, deformation, or even surface scratches on the sealing ring. The demolding process also has defects: the traditional method is to retract the opening claws, relying on the elastic recoil of the sealing ring itself to detach it from the claw pieces and cover the workpiece. During the retraction process, the direction and magnitude of the frictional force between each claw piece and the inner wall of the sealing ring are inconsistent. The sealing ring is prone to misalignment, flipping, or bouncing during elastic recoil, making it impossible to accurately land in the narrow, stepped installation position.

[0004] Second, the retaining circlip is misaligned within the spring cavity. The spring is placed inside the hollow cavity of the plug housing first, followed by a washer and an open retaining circlip on top of the spring. The retaining circlip is then inserted into the annular groove on the inner wall of the cavity to press the spring and washer together. Because the spring generates uneven counterforce during compression, the washer is prone to tilting during insertion, resulting in a loss of concentricity with the inner wall of the cavity. When the retaining circlip is subsequently pressed in, the open end of the circlip makes uneven contact with the already tilted washer surface, further exacerbating the misalignment. Ultimately, this prevents the retaining circlip from accurately engaging in the inner wall groove, leading to assembly defects such as jamming, bounce-out, or partial engagement. Some processes attempt to use a fixed mandrel that can penetrate the cavity as a positioning guide at the bottom of the housing; however, the mandrel rubs and interferes with the inner wall of the spring, easily causing the spring to twist and deform. Furthermore, removing the mandrel may pull out the spring, causing assembly failure.

[0005] Third, there is a lack of a closed-loop quality control system. In the traditional stand-alone operation mode, the inspection data of each process is scattered across independent equipment, making it impossible to form a full-process quality traceability chain indexed by individual products. Hidden defects such as damaged sealing rings and loose snap rings are often only discovered during the final airtightness test, by which time a large amount of unnecessary processing costs have already been incurred.

[0006] Therefore, there is an urgent need for a precision assembly solution that can systematically solve the two core problems of seal ring assembly damage and spring reaction force causing snap ring misalignment within the same assembly system, and achieve full-process quality data traceability. Summary of the Invention

[0007] This invention aims to provide a fully automated assembly and online testing production line for multi-component plugs, solving the technical problems of seal ring assembly damage and snap ring misalignment in the spring cavity in existing technologies. This invention also provides a precision assembly method for plugs using this system. The technical solutions provided by this invention are as follows.

[0008] A fully automated assembly and online testing production line for multi-component plugs includes: a first assembly unit equipped with an adaptive pressing device for a housing outer circumferential sealing ring, the device comprising: multiple first arc blocks, which are assembled into a first seamless cylindrical outer wall surface in an expanded state; a first pusher sleeve, coaxially fitted around the periphery of the first arc blocks; and a first axial drive component, which drives the first pusher sleeve to slide axially, so as to push the expanded sealing ring away from the first seamless cylindrical outer wall surface while the first arc blocks remain in an expanded state.

[0009] The second assembly unit is equipped with a sliding rod-type sealing ring guided automatic assembly mechanism. This mechanism includes: two symmetrically arranged second arc blocks with mutually cooperating guide structures on their splicing end faces. In the expanded state, the guide structures guide the splicing end faces to fit seamlessly together, forming a second seamless cylindrical outer wall surface; a second pusher sleeve, coaxially fitted around the second arc blocks; and a pusher drive device, independent of the drive mechanism that drives the second arc blocks to expand. The pusher drive device drives the second pusher sleeve to slide axially, so as to push the expanded sealing ring away from the second seamless cylindrical outer wall surface while the second arc blocks remain in the expanded state.

[0010] The third assembly unit is equipped with a retaining ring washer air assembly and a double-stage guide pressing device. This device includes: a double-stage coaxial pressure head assembly, consisting of a central front guide shaft and a peripheral pressing cylinder coaxially and fixedly connected. The lower end of the central front guide shaft protrudes downwards from the lower end face of the peripheral pressing cylinder. A retaining ring limiting groove is provided on the outer circumferential surface of the central front guide shaft near its lower end. The outer diameters of both the central front guide shaft and the peripheral pressing cylinder are smaller than the inner diameter of the hollow cavity of the housing to be assembled; and a washer holding device to hold the washer. The washer is positioned directly above the hollow cavity of the housing to be assembled, and its central axis coincides with the central axis of the hollow cavity. The central guide shaft is configured to pass through the inner hole of the washer with a clearance fit. The driving device drives the double-stage coaxial pressure head assembly to perform a pressing action. During pressing, the central guide shaft is first inserted into the hollow cavity for centering and guidance. Then, the peripheral pressing cylinder moves downward to simultaneously push the washer and the open snap ring embedded in the snap ring limiting groove into the hollow cavity.

[0011] Furthermore, the first assembly unit, the second assembly unit, and the third assembly unit are arranged in sequence, and the assembly units are connected by a segmented conveyor line. The workpiece is carried by a fixture and flows between the assembly units.

[0012] Furthermore, it also includes a slide bar pressing unit disposed between the second assembly unit and the third assembly unit, for pressing the slide bar with the assembled sealing ring into the housing to be assembled.

[0013] Furthermore, the sliding rod-type sealing ring guided automatic assembly mechanism of the second assembly unit also includes a quick-change module. The two symmetrically arranged second arc blocks and the second pusher sleeve are integrated into the quick-change module. The quick-change module is detachably connected to the vertical lifting module that drives its lifting and lowering through a detachable docking interface. The detachable docking interface has an end face positioning structure and a multi-way air quick-connect connector.

[0014] Furthermore, the first arc block of the first assembly unit consists of four independent quarter-circular arc blocks, with the sides of adjacent arc blocks joining and contacting each other in the expanded state to form a gapless first seamless cylindrical outer wall surface; the second arc block of the second assembly unit consists of two symmetrically arranged semi-circular arc blocks.

[0015] Furthermore, the driving mechanism of the second assembly unit is a synchronous wedge linkage mechanism, including a wedge block and a power cylinder connected to the wedge block. The two inclined surfaces of the wedge block slide in contact with the inner inclined surfaces of the two second arc blocks respectively, converting the axial movement of the power cylinder into the synchronous radial movement of the two second arc blocks.

[0016] Furthermore, the retaining ring washer air assembly and double-stage guided pressing device of the third assembly unit also includes a pressure sensor and a judgment module; the pressure sensor is connected in series between the force-applying end of the driving device and the double-stage coaxial pressure head assembly, used to detect the reaction force in real time during the pressing process and generate a displacement-pressure curve; the judgment module is configured to determine whether the assembly is qualified based on the characteristic fluctuation inflection point generated at the moment the open retaining ring enters the groove in the displacement-pressure curve. It should be noted that the "characteristic fluctuation inflection point" mentioned in this invention refers to the specific local curve fluctuation pattern on the displacement-pressure curve, where the pressure value briefly decreases and then rises sharply at the moment the open retaining ring enters the groove.

[0017] Furthermore, the washer holding device of the third assembly unit includes a receiving cylinder with openable and closable grippers. When the grippers are closed, they form a positioning hole for holding the washer. When pressed in, the outer pressing cylinder moves downward to contact and push the grippers open, so that the grippers give way and release the washer.

[0018] Furthermore, it also includes a springback force detection unit disposed after the third assembly unit, for detecting the compression springback force of the spring in the housing to be assembled; and / or includes an airtightness detection unit, for performing airtightness detection on the finished product.

[0019] This invention also provides a method for precision assembly of multiple plug components, using the fully automated assembly and online testing production line for multiple plug components as described above, comprising the following steps: Step S1, in the first assembly unit, the plug housing is positioned, the first arc block is expanded and assembled to form a first seamless cylindrical outer wall surface to support the outer peripheral sealing ring, and the first pusher sleeve pushes the outer peripheral sealing ring away and fits into the stepped groove of the plug housing while the first arc block is in an expanded state; Step S2, in the second assembly unit, the slide rod is positioned, the second arc block is expanded and guided by a guide structure to fit the splicing end face to form a second seamless cylindrical outer wall surface to support the slide rod sealing ring, and the second pusher sleeve pushes the outer peripheral sealing ring away and fits into the stepped groove of the plug housing while the first arc block is in an expanded state; Step S2, in the second assembly unit, the slide rod is positioned, the second arc block is expanded and guided by a guide structure to fit the splicing end face to form a second seamless cylindrical outer wall surface to support the slide rod sealing ring, and the second pusher sleeve pushes the outer peripheral sealing ring away and fits into the stepped groove of the second arc block. In step S3, while maintaining the expanded state, push the sliding rod sealing ring away and fit it onto the sliding rod; in step S4, press the sliding rod with the sliding rod sealing ring already assembled into the hollow cavity of the plug housing; in step S5, in the third assembly unit, the central guide shaft picks up the open snap ring and embeds it into the snap ring limiting groove, and aligns the central guide shaft coaxially with the washer held by the washer retaining device and the hollow cavity of the plug housing; drive the double-stage coaxial pressure head assembly downward, the central guide shaft first inserts into the hollow cavity for centering and guidance and resists the internal spring reaction force, and then the outer pressing cylinder moves downward to push the washer and the open snap ring into the hollow cavity simultaneously, so that the open snap ring is engaged in the inner wall groove.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: First, it eliminates seal ring expansion damage. By replacing the traditional multi-claw discrete support with a seamless cylindrical outer wall formed by multiple first arc blocks or two second arc blocks, the inner ring of the seal ring experiences a continuous and uniform radial support force throughout its circumference when expanded. This fundamentally eliminates localized stress concentration, torsion, and tensile deformation caused by gaps between the claws. Those skilled in the art before the application date could not have foreseen that forming a seamless cylindrical surface with arc blocks could fundamentally solve the seal ring expansion damage problem, because traditionally, multi-claw expansion was considered the industry standard, and increasing the number of segments only improved, not eliminated, uneven expansion.

[0021] Second, it eliminates demolding scratch damage. An independently driven pusher sleeve pushes the sealing ring axially away while the arc block remains in an expanded state. The supporting component does not shrink throughout the process, fundamentally eliminating friction and scratching between the supporting component and the inner wall of the sealing ring during traditional shrinkage demolding, as well as sealing ring misalignment, flipping, and bouncing caused by inconsistent frictional forces. Those skilled in the art before the application date could not have foreseen that demolding while the supporting component remains expanded would achieve reliable detachment and precise positioning of the sealing ring. This is because there has long been a technical bias in the field that demolding cannot be achieved in the expanded state, requiring the supporting component to shrink first to make way. Research and development have generally focused on optimizing shrinkage parameters and surface treatments to reduce scratching, rather than completely avoiding the shrinkage action itself.

[0022] Third, it overcomes the misalignment of the retaining ring caused by the spring reaction force. By inserting the central guide shaft into the hollow cavity of the housing to be assembled before the washer and the open retaining ring, a radial positioning reference is established throughout all parts. The uneven upward reaction force of the spring is absorbed and canceled by the clearance fit between the central guide shaft and the inner wall of the cavity, and no longer acts on the radial direction of the parts, fundamentally eliminating the generation of misalignment torque. Subsequently, the outer pressing cylinder moves down along the central guide shaft, pushing the washer and the open retaining ring into the cavity simultaneously. Throughout the entire process of being pushed in, the parts are always radially constrained by the central guide shaft, ensuring the absolute concentric pressing of the washer and the retaining ring in the narrow cavity. Those skilled in the art before the application date could not have foreseen that the spring reaction force, a traditionally recognized disadvantage, would actually be transformed into a stabilizing force pressing the washer and the retaining ring against the lower end face of the outer pressing cylinder after the central guide shaft is inserted. This transformation of disadvantage into advantage breaks through the inherent thinking in the field.

[0023] Fourth, the dual-lobed design offers a superior advantage in terms of continuous expansion with minimal seams. The second assembly unit uses only two semi-circular blocks joined together to form a seamless cylindrical surface, reducing the number of seams to a theoretical minimum. This achieves maximum cylindrical surface continuity with minimal seams. Each seam is a potential point of failure for cylindrical surface continuity. While increasing the number of arc blocks can reduce the size of individual seams, the total number of seams increases, leading to a greater accumulation of micro-suspended areas of the sealing ring at the seams. The dual-lobed design maximizes the continuous support area of ​​the cylindrical surface while ensuring the expansion function—a technical effect that cannot be achieved by multi-lobed designs using three or four or more arc blocks. Those skilled in the art could not have foreseen before the application date that this choice of achieving optimal expansion uniformity with the fewest lobes would break through the conventional thinking that more lobes equate to more uniform expansion.

[0024] Fifth, the quick-change module enables efficient model changeover. When further including a detachable docking interface, by integrating the second arc block and the second pusher sleeve into a standardized quick-change module, and with the end-face positioning structure and multi-channel pneumatic quick-connect connector, the model changeover operation is simplified to a module-level overall replacement, significantly shortening the model changeover time. Furthermore, the end-face positioning structure ensures repeatable installation accuracy, eliminating the need for recalibration. Those skilled in the art before the application date could not have foreseen that integrating the precision opening and demolding components into a standardized quick-change module, along with the integrated pneumatic and electrical quick-connect interface, would enable rapid model changeovers within minutes.

[0025] Sixth, online non-destructive full inspection. When further including pressure sensors and a judgment module, by recording the displacement-pressure curve throughout the pressing process in real time, the inflection point of the characteristic fluctuation generated by the sudden drop in resistance and the sharp rise in elastic reset at the moment the open retaining ring enters the groove is used to determine whether the assembly is qualified. Non-destructive online full inspection of each product can be achieved without additional inspection stations. Those skilled in the art before the application date could not have foreseen that the minute mechanical characteristic signal of the retaining ring entering the groove could be effectively identified and separated in the background reaction force of the continuously increasing spring. This discovery breaks through the technical prejudice that the spring reaction force would drown out the retaining ring entering the groove signal.

[0026] Seventh, the system-level effect of the three-unit collaboration. The quality of the outer peripheral sealing ring assembled by the first assembly unit affects the final airtightness; the quality of the sliding rod sealing ring assembled by the second assembly unit affects the sealing reliability after the sliding rod is pressed in; the pressing quality of the snap ring in the third assembly unit intercepts defective products through online judgment, preventing them from flowing into subsequent processes and causing ineffective processing. The assembly quality of the three assembly units is coupled with each other, and the convergence of full-process inspection data forms a full life-cycle quality traceability chain indexed by a single product. This system-level collaborative effect exceeds the sum of the effects of each assembly unit used individually, resulting in an overall yield improvement that exceeds expectations. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 The first half of the 2D planar process layout diagram of the entire production line of this invention shows the series relationship from station 1 to station 4 from left to right, including the station layout of plug shell feeding and outer peripheral sealing ring assembly, slide rod feeding and slide rod sealing ring assembly, plug assembly assembly, and spring washer and snap ring feeding and pressing.

[0029] Figure 2 The second half of the 2D planar process layout diagram of the entire production line of this invention shows the series relationship from station 5 to station 8 from left to right, including the layout of the stations for plug assembly spring force detection, plug outer O-ring assembly, plug finished product coding and scanning traceability, helium inspection equipment and material unloading, as well as the division of material supply areas at each level.

[0030] Figure 3 This is a 3D isometric drawing of the entire production line of the present invention, showing the physical appearance of the front-end SCARA robot, the segmented frame, and the rear vibrating feeding system.

[0031] Figure 4 This is a schematic diagram of the overall three-dimensional structure of the adaptive pressing device for the outer circumferential sealing ring of the shell in the first assembly unit, showing the overall layout of the basic frame, the lateral displacement drive assembly, the Z-axis vertical lifting drive module, and the sealing ring opening and demolding assembly.

[0032] Figure 5 for Figure 4 The side view of the device shows the assembly height relationship of each functional module along the vertical direction. The enlarged view below shows the fit between the inclined inner wall of the quarter-circle block and the sealing ring when it is wrapped around the outer edge of the cylindrical surface.

[0033] Figure 6 for Figure 4 The schematic diagram of the device shows the supporting frame formed by the vertical support columns and the horizontal cantilever beams of the basic frame, the transmission cooperation between the guide rod cylinder and the slide in the horizontal displacement drive assembly, and the power transmission structure of the servo motor driving the vertical slide in the Z-axis vertical lifting drive module.

[0034] Figure 7 This is a three-dimensional structural diagram of the first assembly unit from another perspective, showing the state of the sealing ring opening the demolding component installed at the end of the Z-axis module, as well as the spatial layout of the feeding component relative to the base frame and the overall coordination relationship of each motion axis.

[0035] Figure 8 This is a schematic diagram of the overall structure of the sliding rod-type sealing ring guided automatic assembly mechanism in the second assembly unit, showing the spatial layout of the quick-change module, vertical lifting module, horizontal moving module and vibrating feeding channel.

[0036] Figure 9 for Figure 8 A schematic diagram of the overall structure of the mechanism shown from another perspective.

[0037] Figure 10 for Figure 8 The enlarged portion and structural diagram of the mechanism shown illustrate the structural details of the multi-way quick-connect air connector with detachable docking interface, the guide structure of the semi-circular block splicing end face, and the synchronous wedge linkage mechanism.

[0038] Figure 11 This is a schematic diagram of the overall structure of the circlip washer air assembly and double-stage guide pressing device in the third assembly unit, showing the assembly relationship of the double-stage coaxial pressure head assembly, washer holding device, circlip supply device and drive device.

[0039] Figure 12 for Figure 11 The enlarged schematic diagram of a partial detail of the device shows the retaining groove structure at the lower end of the central guide shaft.

[0040] Figure 13 for Figure 11 The enlarged schematic diagram of a partial detail of the device shows the structural details of the openable gripper of the gasket retainer and the receiving cylinder.

[0041] The correspondence between the numbers and component names in the diagram is as follows: 1000 Adaptive pressing device for outer perimeter sealing ring of housing; 1001 Basic frame; 1011 Vertical support column; 1012 Horizontal cantilever beam; 1002 Horizontal displacement drive assembly; 1021 Guide rod cylinder; 1022 Slide table; 1003 Z-axis vertical lifting drive module; 1031 Servo motor; 1032 Vertical slide table; 1004 Sealing ring opening and demolding assembly; 1041 Base; 1042 First arc. Block, 1421 Inclined surface, 1043 Power mechanism, 1044 First pusher sleeve, 1045 First axial drive component, 1046 Limiting block, 1005 Sealing ring feeding assembly, 1051 Linear vibrating feeder, 1052 Distributing cylinder, 1006 Sealing ring, 2000 Slide rod type sealing ring guide automatic assembly mechanism, 2001 Detachable docking interface, 2011 Multi-channel air quick connector, 2002 Second arc block, 2021 Guide structure, 200 3. Second pusher sleeve; 2004. Quick-change module; 2005. Drive mechanism; 2051. Wedge block; 2052. Power cylinder; 2006. Pusher drive device; 2061. Independent cylinder; 2007. Vertical lifting module; 2008. Lateral movement module; 2009. Vibrating feeding channel; 3000. Snap ring washer aerial assembly and double-stage guide pressing device; 3001. Double-stage coaxial pressure head assembly; 3011. Central front guide shaft; 3111. Snap ring limiting groove; 3012. Peripheral pressing. Cylinder, 3002 Washer retaining device, 3021 Receiving cylinder, 3211 Gripper, 3003 Snap ring supply device, 3031 Straight vibrating material channel, 3032 Pneumatic shift fork material distribution mechanism, 3004 Drive device, 3041 Y-axis transverse movement mechanism, 3042 Z-axis lifting mechanism, 4001 Segmented conveyor line, 4002 Fixture, 4003 SCARA robot, 4004 Vibrating feeding system, 4005 Slide bar pressing unit, 4006 Rebound force detection unit. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of this invention, and are not intended to limit the scope of protection of this invention. In the description of this invention, it should be understood that the terms "upper," "lower," "horizontal," "vertical," "axial," and "radial," etc., indicate the orientation or positional relationship based on the orientation or positional relationship of the device under normal operating conditions. They are only for the convenience and simplification of description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0043] This embodiment provides a fully automated assembly and online testing production line for multiple plug components, comprising a first assembly unit, a second assembly unit, and a third assembly unit arranged sequentially. The assembly units are connected by a segmented conveyor line 4001, and the workpieces are carried by a dedicated fixture 4002 and flow between the assembly units. In one embodiment, the segmented conveyor line 4001 has a linear layout, with the first, second, and third assembly units arranged sequentially along a straight line. In another embodiment, the segmented conveyor line 4001 has a circular layout, with the first, second, and third assembly units distributed along a circular trajectory. Empty fixtures 4002 automatically return to the beginning of the line via the lower return section of the circular conveyor line 4001, saving equipment space. In yet another embodiment, the segmented conveyor line 4001 has a U-shaped layout, with the first and second assembly units located on one arm of the U, and the third assembly unit located on the other arm. A sliding rod pressing unit 4005 is located at the bottom bend of the U, allowing the operator to simultaneously monitor the operating status of multiple assembly units from the open side of the U.

[0044] The first assembly unit is used to load the plug housing and precisely assemble the outer sealing ring. The second assembly unit is used to load the slide rod and precisely assemble the slide rod sealing ring. The third assembly unit is used to precisely press the spring, washer, and open retaining ring into the housing with the pre-installed slide rod. Between the second and third assembly units, there is a slide rod pressing unit 4005, used to press the slide rod with the assembled sealing ring into the hollow cavity of the plug housing. Following the third assembly unit, there are sequentially a spring force detection unit 4006 and an airtightness detection unit, used to detect whether the spring compression spring force meets the standard and whether the finished product airtightness is qualified, respectively.

[0045] The first assembly unit is equipped with a housing outer circumferential sealing ring adaptive pressing device 1000. This device includes a base frame 1001, a lateral displacement drive assembly 1002, a Z-axis vertical lifting drive module 1003, and a sealing ring opening and demolding assembly 1004. The sealing ring opening and demolding assembly 1004 includes multiple first arc blocks 1042. In one embodiment, the first arc blocks 1042 are four independent quarter-arc blocks, each with a central angle of 90 degrees. In the expanded state, the sides of adjacent arc blocks are in contact, and the outer arc surfaces collectively define a gapless first seamless cylindrical outer wall surface. In another embodiment, the first arc blocks 1042 are six independent one-sixth arc blocks, each with a central angle of 60 degrees. Compared to the four-lobed structure, the six-lobed structure has a smaller outer diameter in the folded state, facilitating the insertion of a sealing ring with a smaller inner diameter. In another embodiment, the first arc block 1042 consists of three independent arc blocks, each with a central angle of 120 degrees. This three-part structure has fewer parts and a simpler mechanism, making it suitable for large-sized sealing rings with relatively low assembly precision requirements. In the above multi-part structure, the number of arc blocks can be selected based on the inner diameter of the sealing ring to be assembled and the assembly precision requirements.

[0046] The radial expansion and contraction of the first arc block 1042 are driven by a power mechanism 1043. In one embodiment, the power mechanism 1043 includes a conical push block and a miniature cylinder that drives the conical push block to move axially. The conical push block has an outer conical surface, and the inner walls of the four first arc blocks 1042 are respectively provided with inclined surfaces 1421 that cooperate with the outer conical surface of the conical push block. When the miniature cylinder drives the conical push block to move downward, the outer conical surface pushes the inclined surface 1421, converting the axial motion into a synchronous radial outward expansion motion of the first arc block 1042. The cone angle of the outer conical surface of the conical push block is smaller than the self-locking friction angle. When the conical push block moves to the lower dead center, a mechanical self-lock occurs between the outer conical surface and the inclined surface 1421. Even if the miniature cylinder is de-aired, the first arc block 1042 can still be stably maintained in the expanded state. In another embodiment, the power mechanism 1043 uses a stepper motor in conjunction with a lead screw and nut mechanism to directly drive the axial movement of the conical push block. The radial expansion of the arc block is precisely adjusted by a controller to accommodate sealing rings of different inner diameters. In yet another embodiment, the power mechanism 1043 employs a cam mechanism. The cam is continuously rotated by a micro motor, periodically driving the push rod through a contour curve to push the conical push block and achieve radial movement. The cam curve can be designed to have three working stages: expansion, holding, and contraction. In yet another embodiment, the power mechanism 1043 driving the radial expansion of the first arc block 1042 is hydraulically driven, including a micro hydraulic cylinder and a hydraulic pump station. The piston rod of the micro hydraulic cylinder is connected to the conical push block, and the hydraulic pump station supplies oil to the hydraulic cylinder through pipelines, pushing the conical push block to move axially. Hydraulic oil has extremely low compressibility, and the conical push block can maintain a stable force at any intermediate position. Position locking can be achieved at any expansion amount of the first arc block 1042 without relying on the self-locking of the conical surface. The expansion amount of the first arc block 1042 can be infinitely adjusted, and one mechanism can adapt to sealing rings with various inner diameter specifications.

[0047] The first pusher sleeve 1044 is coaxially fitted around the cylindrical surface formed by the first arc block 1042. The first pusher sleeve 1044 has an annular cylindrical structure, with its inner diameter slightly larger than the outer diameter of the cylindrical surface, forming a clearance fit. In one embodiment, the inner peripheral edge of the first pusher sleeve 1044 is a right-angled sharp edge. When moving downwards, this sharp edge directly presses against the inner edge of the top surface of the sealing ring, using concentrated force to push the sealing ring away from the cylindrical surface, which is suitable for sealing rings made of harder materials. In another embodiment, the inner peripheral edge of the first pusher sleeve 1044 has an inwardly facing annular protrusion. The lower surface of this protrusion is a plane. When pushing material, the annular plane presses against the top surface of the sealing ring, increasing the pressing contact area, which is suitable for soft materials or sealing rings with strict appearance requirements. In another embodiment, the inner peripheral edge of the first pusher sleeve 1044 is a tapered transition structure that gradually expands downward. The small end of the tapered surface is connected to the inner wall of the first pusher sleeve 1044, and the large end faces the sealing ring. When pushing the material, the tapered surface gradually guides the sealing ring to the radially outward, further reducing the vertical impact of the sealing ring falling when it leaves the cylindrical surface.

[0048] The first axial drive component 1045 is connected to the first pusher sleeve 1044 and drives its axial sliding. The first axial drive component 1045 is independent of the power mechanism 1043 that drives the first arc block 1042. In one embodiment, the first axial drive component 1045 is an external cylinder, and its stroke can be controlled by adjusting the cylinder intake pressure or the limit stop 1046. In another embodiment, the first axial drive component 1045 is a motor-driven lead screw and nut pair. When the motor rotates, the lead screw and nut move linearly along the axial direction, driving the first pusher sleeve 1044 to slide axially along the outer wall of the arc block. The axial displacement, speed, and thrust of the first pusher sleeve 1044 can be precisely controlled by the motor parameters. In yet another embodiment, the first axial drive component 1045 is a voice coil motor. The mover of the voice coil motor is directly connected to the upper end of the first pusher sleeve 1044, forming a force closed-loop control with a force sensor, accurately sensing the force change at the moment the sealing ring detaches from the cylindrical surface during the pushing process.

[0049] The second assembly unit is equipped with a sliding rod-type sealing ring guided automatic assembly mechanism 2000. This mechanism includes two symmetrically arranged second arc blocks 2002. Each second arc block 2002 is a semi-circular arc block with a central angle of 180 degrees, and the radius of curvature of its outer wall surface is consistent with the radius of the cylindrical surface required in the unfolded state. The two semi-circular arc blocks are mounted on the base of the quick-change module 2004 via linear guide rails at the bottom, allowing for precise linear sliding in the radial direction.

[0050] The splicing end faces of the two second arc blocks 2002 are respectively provided with mutually cooperating guide structures 2021. In one embodiment, the guide structure 2021 is a V-shaped groove and a V-shaped ridge. One end face is machined with a V-shaped groove extending axially, and the other end face is machined with a corresponding V-shaped ridge. The mating surfaces of the V-shaped groove and the V-shaped ridge are precision ground. When the two second arc blocks 2002 expand radially to their limit positions, the V-shaped ridge is embedded in the V-shaped groove, automatically correcting the relative positions of the two arc blocks. In another embodiment, the guide structure 2021 is a tapered pin hole and a tapered pin. When the tapered pin is inserted into the tapered pin hole, the self-centering function of the tapered surface achieves a seamless fit. In yet another embodiment, the guide structure 2021 is a stepped overlapping guide. One splicing end face is machined as an L-shaped stepped surface that is concave inward along the radial direction, and the other splicing end face is machined as a corresponding convex L-shaped stepped surface. In the expanded state, the convex step is embedded in the concave step. In another embodiment, the guide structure 2021 is an arc-shaped tooth meshing guide, with two splicing end faces respectively machined with mutually meshing arc-shaped tooth structures. The teeth extend axially, and in the expanded state, the two sides of the teeth interlock and mesh. In yet another embodiment, the guide structure 2021 adopts an elastic pre-tightening guide structure, including an axially extending convex key disposed on the splicing end face of one side of the second arc block 2002, and a corresponding groove disposed on the splicing end face of the other side of the second arc block 2002. The width of the groove is slightly larger than the width of the convex key at the entrance, and gradually narrows at the bottom to form a transition fit or a slight interference fit with the convex key. When the two second arc blocks 2002 expand radially to near the splicing position, the convex key first enters the wide opening area of ​​the groove, and then, during the continued expansion process, the convex key is gradually guided by the narrowing sidewall of the groove, and finally, in the fully expanded state, the convex key forms a tight fit with the bottom of the groove, eliminating the splicing seam. The narrowed area of ​​the groove has elastic deformation capability. Even if there are minor processing errors in the key and the groove, the elastic deformation of the narrowed area can compensate for the error and ensure a seamless fit of the splicing end faces.

[0051] The radial drive of the second arc block 2002 is achieved by the drive mechanism 2005. In one embodiment, the drive mechanism 2005 is a synchronous wedge linkage mechanism, which includes a wedge block 2051 and a power cylinder 2052 connected to the upper end of the wedge block 2051. The wedge block 2051 is located at the center between the two second arc blocks 2002, and symmetrical inclined surfaces are machined on both sides. The inner bottom of the two second arc blocks 2002 is correspondingly machined with inner inclined surfaces that match the inclined surfaces of the wedge block 2051. When the power cylinder 2052 drives the wedge block 2051 to move downward along the axial direction, the inclined surfaces of the wedge block 2051 push the two second arc blocks 2002 to expand radially outward synchronously through sliding contact. Unlike the cone-face pusher scheme that uses a single outer cone surface to simultaneously drive multiple arc blocks, the two inclined surfaces of the wedge block 2051 independently drive a second arc block 2002, with a one-to-one force transmission path. The machining area and fitting accuracy of the driving surface are precisely matched to the double-lobed structure. In another embodiment, the drive mechanism 2005 adopts an electrical synchronization scheme, with two independent servo motors connected to the corresponding second arc block 2002 via ball screw pairs. The control system achieves radial motion synchronization through a high-speed synchronous control algorithm. In yet another embodiment, the drive mechanism 2005 adopts a double eccentric cam mechanism, with a single motor driving the camshaft, and two cams driving the corresponding second arc block 2002 to perform synchronous radial motion.

[0052] The second pusher sleeve 2003 is coaxially fitted around the two second arc blocks 2002, forming a complete circular ring structure. The fit clearance between the inner diameter of the second pusher sleeve 2003 and the outer diameter of the cylindrical outer wall formed by the two second arc blocks 2002 is controlled within the range of 0.02mm to 0.05mm. This clearance is less than one-tenth of the diameter of a conventional sealing ring, so the sealing ring cannot be squeezed into this clearance during the pushing process. In one embodiment, the lower edge of the second pusher sleeve 2003 is machined with a rounded corner transition structure to prevent local stress concentration or scratches on the top surface of the sealing ring during the pushing process.

[0053] The pusher drive device 2006 and the drive mechanism 2005 are independent of each other. In one embodiment, the pusher drive device 2006 is an independent cylinder 2061, which is fixedly installed on the side wall of the quick-change module 2004. Its piston rod is connected to the second pusher sleeve 2003 through a connecting bracket. The air circuit of the independent cylinder 2061 and the air circuit of the power cylinder 2052 are controlled by different solenoid valves, and the stroke, speed, and action sequence of both can be set independently. In another embodiment, the pusher drive device 2006 uses a motor-driven lead screw and nut pair. When the motor rotates, the lead screw and nut move linearly along the axial direction, driving the second pusher sleeve 2003 to slide axially along the outer wall of the second arc block 2002. The speed and thrust can be precisely set through motor parameters. In yet another embodiment, the pusher drive device 2006 uses a voice coil motor, which has the characteristics of fast response speed and high force control accuracy. Real-time closed-loop control of the pushing force can be achieved through current feedback. In another embodiment, the independence of the pusher drive device 2006 and the drive mechanism 2005 is further demonstrated by the following structure: the pusher drive device 2006 and the drive mechanism 2005 are respectively mounted on different mounting reference surfaces of the quick-change module 2004, and their drive force transmission paths are completely separated in space. The power cylinder 2052 of the drive mechanism 2005 is mounted on the upper base of the quick-change module 2004, and its driving force is transmitted vertically downward to the wedge block 2051, and then converted into the radial movement of the second arc block 2002; the independent cylinder 2061 of the pusher drive device 2006 is mounted on the side wall of the quick-change module 2004, and its driving force is transmitted vertically downward to the second pusher sleeve 2003. The two drive paths are arranged orthogonally or parallel but not intersecting in space, and there are no shared transmission components between them. This spatially separated drive layout not only achieves the independence of control and action, but also allows the pusher drive device 2006 and the drive mechanism 2005 to use different types of power sources respectively.

[0054] The quick-change module 2004 integrates two second arc blocks 2002 and a second pusher sleeve 2003 into one unit, and is detachably connected to the vertical lifting module 2007 that drives its lifting and lowering via a detachable docking interface 2001. The detachable docking interface 2001 has an end face positioning structure. In one embodiment, the end face positioning structure is a stop positioning structure, where the inner cylindrical surface of the stop and the outer cylindrical surface of the upper end of the quick-change module 2004 form a precision clearance fit to ensure the radial position accuracy of the quick-change module 2004 after each installation. In another embodiment, the end face positioning structure is in the form of a flange face plus a positioning pin. The positioning pin on the upper end face of the quick-change module 2004 is inserted into the positioning pin hole on the lower end face of the end face positioning structure to achieve precise radial positioning. After the flange faces are fitted, they are locked by a quick-clamping buckle. The detachable docking interface 2001 also integrates a multi-channel pneumatic quick-connect connector 2011 and an electrical signal interface, which are used to transmit the pneumatic circuits for driving the second arc block 2002 and driving the second pusher sleeve 2003, as well as to transmit the position detection signal of the second arc block 2002 and the position detection signal of the second pusher sleeve 2003, so as to realize the integrated quick docking of the pneumatic circuit and the electrical signal.

[0055] When the product model changes and a different specification of slide bar seal ring needs to be replaced, the following changeover procedure should be followed. First, the control system issues a changeover command, and each assembly unit pauses operation after completing the assembly of the current workpiece. The operator removes the quick-change module 2004 entirely from the detachable docking interface 2001. The end face positioning structure can be separated without tools, and the multi-channel pneumatic quick-connect connector 2011 and the electrical signal interface are simultaneously disconnected. Then, the operator installs another quick-change module 2004 adapted to the new specification seal ring onto the detachable docking interface 2001. The end face positioning structure ensures the radial position accuracy after installation. Simultaneously, the operator adjusts the stroke parameters of the first axial drive component 1045 in the first assembly unit according to the cross-sectional diameter and hardness of the new specification outer peripheral sealing ring, or replaces the first pusher sleeve 1044 with an adapted inner diameter and edge structure, and accordingly adjusts the stroke of the conical push block in the power mechanism 1043 or replaces the first arc block 1042 of the corresponding specification; according to the outer diameter of the new specification gasket and the specification of the open retaining ring, the operator replaces the gripper 3211 in the third assembly unit to obtain an adapted positioning hole diameter, or replaces the entire double-stage coaxial pressure head assembly 3001 to adapt to different cavity depths and retaining ring sizes, and updates the preset qualified threshold window parameters in the judgment module accordingly. After completing the above mechanical adjustments, the operator selects the pre-stored new specification product program through the control system, and the control system automatically calls the corresponding motion parameters, pressure thresholds, and judgment criteria. If the quick-change module 2004 is equipped with a module identification element, the control system reads the specification information in the module identification element and automatically matches the corresponding preset motion parameters to achieve one-click automatic parameter switching. After the changeover is completed, the first piece is assembled and tested for confirmation, and continuous production resumes after confirmation of qualification. The entire changeover process can be completed in minutes without recalibrating the center position of each assembly unit.

[0056] The third assembly unit is equipped with a snap ring washer air assembly and a double-stage guide pressing device 3000. This device includes a double-stage coaxial pressure head assembly 3001, a washer holding device 3002, a snap ring supply device 3003, and a drive device 3004.

[0057] The dual-stage coaxial indenter assembly 3001 is coaxially and fixedly connected by a central guide shaft 3011 and a peripheral indentation cylinder 3012, forming a stepped cylinder. The central guide shaft 3011 is located at the lower end of the assembly, its diameter is smaller than the diameter of the peripheral indentation cylinder 3012, and it protrudes downward from the lower end face of the peripheral indentation cylinder 3012. A retaining ring limiting groove 3111 is provided on the outer peripheral surface of the central guide shaft 3011 near its lower end. In one embodiment, the retaining ring limiting groove 3111 is an annular groove, the bottom diameter of which is less than or equal to the inner diameter of the open retaining ring in its free state. The outer peripheral diameter of the central guide shaft 3011 in the areas above and below the retaining ring limiting groove 3111 is larger than the free inner diameter of the open retaining ring, so that when the open retaining ring reaches the groove position, its open end contracts and embeds into the groove under its own elastic restoring force, achieving radial and axial stable fixation. In another embodiment, the retaining ring limiting groove 3111 consists of multiple circumferentially distributed arc-shaped groove segments, with the bottom of each groove segment being circular. This reduces the amount of groove machining while still providing stable retaining ring insertion and fixation. The outer diameters of the central guide shaft 3011 and the peripheral press-in cylinder 3012 are both smaller than the inner diameter of the hollow cavity of the housing to be assembled, and both form a clearance fit with the inner wall of the cavity. The axial distance between the lower end face of the central guide shaft 3011 and the lower end face of the peripheral press-in cylinder 3012 is greater than the sum of the thickness of the washer and the thickness of the open retaining ring, ensuring that after the central guide shaft 3011 has been inserted into the cavity to a sufficient depth and completed centering and guidance, the washer and the open retaining ring are still located below the lower end face of the peripheral press-in cylinder 3012. In one embodiment, the central guide shaft 3011 and the peripheral press-in cylinder 3012 of the double-stage coaxial pressure head assembly 3001 adopt a split structure, which is connected by a sliding fit and has an independent drive source to control the axial movement of each. The central guide shaft 3011 is driven to extend first by an independent power source, and the peripheral pressing cylinder 3012 is driven to descend subsequently by the Z-axis lifting mechanism 3042. This changes the timing control of the centering and pushing actions from relying on geometric dimensions to relying on independent power control, making timing adjustments more flexible. In another embodiment, the upper end of the central guide shaft 3011 is provided with an external thread section, and the upper part of the central hole of the peripheral pressing cylinder 3012 is provided with a corresponding internal thread section. The central guide shaft 3011 is screwed into the peripheral pressing cylinder 3012 through the thread. The protrusion length of the central guide shaft 3011 is changed by adjusting the screwing depth. After adjustment, it is locked by a lock nut. This allows it to adapt to housing cavities of different depths without replacing the entire double-stage coaxial pressure head assembly 3001.

[0058] The gasket holding device 3002 is used to hold the gasket directly above the hollow cavity of the housing to be assembled, with the central axis of the held gasket coinciding with the central axis of the hollow cavity. In one embodiment, the gasket holding device 3002 includes a receiving cylinder 3021 with openable and closable grippers 3211. The grippers 3211 consist of two symmetrical claws. In the closed state, the front ends of the two claws together form a positioning hole for holding the gasket, which is suspended and fixed within the positioning hole. The grippers 3211 have built-in elastic elements that apply a preload force to make the grippers 3211 tend to close. When the outer pressing cylinder 3012 moves downward and contacts the outer inclined surface of the grippers 3211, the grippers 3211 overcome the elastic force of the elastic elements and open outward, releasing the gasket. After the outer pressing cylinder 3012 moves upward and retracts, the elastic elements drive the grippers 3211 to automatically reset and close. In another embodiment, the gasket retaining device 3002 employs a vacuum adsorption method, featuring a suction cup with an adsorption hole. The lower end face of the suction cup has a groove for accommodating the gasket, and the gasket is adsorbed and fixed to the top of the housing by negative pressure. In yet another embodiment, the gasket retaining device 3002 employs an elastic sleeve, which is a cylindrical sleeve with at least two slits along the axial direction. The slits divide the lower end of the sleeve into multiple radially elastically deformable lobes. The inner wall surfaces of each lobe together form a clamping hole for accommodating the gasket, and the gasket is clamped in the clamping hole by the elastic lobes with an interference fit. In yet another embodiment, the gasket retaining device 3002 employs a magnetic retaining method, suitable for gaskets made of ferromagnetic materials. The gasket retaining device 3002 includes an electromagnet and a positioning ring fixed to the lower end face of the electromagnet. The inner diameter of the positioning ring matches the outer diameter of the gasket, and the lower end face of the positioning ring has a shallow groove for accommodating the gasket. When the electromagnet is energized, it generates a magnetic field that attracts the washer into the shallow groove, and the washer is suspended and held directly above the hollow cavity of the housing to be assembled.

[0059] The drive unit 3004 is connected to the double-stage coaxial pressure head assembly 3001 and is used to drive the double-stage coaxial pressure head assembly 3001 to perform the pressing action. In one embodiment, the drive unit 3004 includes a Y-axis traverse mechanism 3041 and a Z-axis lifting mechanism 3042 mounted on the drive end of the Y-axis traverse mechanism 3041. The Y-axis traverse mechanism 3041 drives the pressure head assembly to move horizontally between the discharge position of the snap ring supply device 3003 and the assembly position, and the Z-axis lifting mechanism 3042 drives the pressure head assembly to move vertically. In another embodiment, the Z-axis lifting mechanism 3042 of the drive unit 3004 adopts a pneumatic slide table connected in series with a hydraulic damper. The pneumatic slide table provides a large stroke movement for rapid downward and upward movement, and the hydraulic damper provides speed damping at the end of the pressing stroke.

[0060] In one embodiment, the third assembly unit further comprises a pressure sensor and a determination module. The pressure sensor is connected in series between the force application end of the driving device 3004 and the two-stage coaxial indenter assembly 3001, and is configured to detect the reaction force in real time during the press-fitting process and generate a displacement-pressure curve. The determination module is configured to determine whether the assembly is qualified according to the characteristic fluctuation inflection point generated at the moment when the split circlip enters the groove in the displacement-pressure curve. In the normal press-fitting process, the curve first shows a gradually rising trend as the spring is compressed. When the split circlip reaches the position of the clamping groove, its open end springs into the clamping groove instantly, the contact force drops sharply for a short time, then the lower end face of the circlip comes into contact with the washer to bear force, and the curve rises steeply. This non-linear inflection point that first drops and then rises is the characteristic fluctuation inflection point. The determination module analyzes the curve in real time, and when the characteristic fluctuation inflection point is detected and its time position and amplitude fall into the preset qualified threshold window, the assembly is determined to be qualified. In another embodiment, the determination module adopts a dual-threshold window determination logic. A displacement window and a pressure window are preset on the displacement-pressure curve, and the determination module detects whether the actual curve has a step change in which the pressure value jumps into the pressure window within the displacement window, and if so, the assembly is determined to be qualified. This solution has higher tolerance to signal noise, and is suitable for working conditions with fast press-fitting speed and limited curve sampling density. In yet another embodiment, the determination module adopts a machine learning-assisted determination logic to replace the preset threshold determination. The determination logic includes a pre-trained neural network model. The input features of the model include multiple dimensions such as the local gradient of the displacement-pressure curve, the curvature change rate, the pressure peak value and the displacement position corresponding to the peak value, and the output is the probability value of qualified assembly. When the probability value is higher than the preset confidence threshold, the assembly is determined to be qualified.

[0061] The precision assembly method for multiple plug components provided in this embodiment uses the above-mentioned assembly system, and specifically includes the following steps.

[0062] Step S1: In the first assembly unit, the plug housing is loaded and precisely positioned on the fixture 4002. The first arc block 1042 is in a contracted state, with its outer diameter smaller than the inner diameter of the outer circumferential sealing ring. The first arc block 1042 smoothly passes through the inner hole of the outer circumferential sealing ring. The power mechanism 1043 drives the first arc block 1042 to expand, and multiple first arc blocks 1042 expand radially outward synchronously until they are assembled into the outer wall surface of the first seamless cylinder, evenly spreading the outer circumferential sealing ring. The lateral displacement drive assembly 1002 moves the first arc block 1042 carrying the outer circumferential sealing ring to directly above the installation position of the plug housing. The first axial drive member 1045 drives the first pusher sleeve 1044 to move downward along the outer wall surface of the first seamless cylinder. The inner circumferential edge of the first pusher sleeve 1044 pushes the top surface of the outer circumferential sealing ring, evenly pushing the outer circumferential sealing ring away from the outer wall surface of the first seamless cylinder. The outer circumferential sealing ring falls smoothly into the stepped groove of the plug housing in a complete circular shape. The first pusher sleeve 1044 rises and resets, and the first arc block 1042 retracts and resets. In a preferred system layout, the first assembly unit and the second assembly unit share the same fixture 4002 positioning reference. A traveling fixture 4002 is provided on the segmented conveyor line 4001. The fixture 4002 simultaneously provides a first positioning part for positioning the plug housing and a second positioning part for positioning the slide rod. The relative positional accuracy between the first and second positioning parts is ensured by the machining accuracy of the fixture 4002. When the fixture 4002, carrying the plug housing with the assembled outer peripheral sealing ring, flows from the first assembly unit to the second assembly unit, the plug housing is still precisely held by the first positioning part, eliminating the need for re-clamping; simultaneously, the second positioning part provides precise positioning for the slide rod. This layout, sharing the positioning reference of the fixture 4002, ensures that the relative positional accuracy between the outer peripheral sealing ring assembled in the first assembly unit and the slide rod sealing ring assembled in the second assembly unit is guaranteed at once by the machining accuracy of the fixture 4002, avoiding the accumulation of secondary positioning errors caused by repeated clamping of the workpiece between different assembly units.

[0063] Step S2: In the second assembly unit, the slide bar is loaded and precisely positioned on the fixture 4002. The second arc block 2002 is in a contracted state, with its outer diameter smaller than the inner diameter of the slide bar sealing ring. The second arc block 2002 smoothly passes through the inner hole of the slide bar sealing ring. The drive mechanism 2005 drives the second arc block 2002 to expand. The two second arc blocks 2002 are guided by the guide structure 2021 to seamlessly fit their splicing end faces, forming the outer wall surface of the second seamless cylinder, which evenly expands the slide bar sealing ring. While the second arc block 2002 remains in an expanded state, the pusher drive device 2006 drives the second pusher sleeve 2003 to move axially, pushing the slide bar sealing ring away from the outer wall surface of the second seamless cylinder, allowing it to fit into the designated installation position of the slide bar. The second pusher sleeve 2003 moves upward to reset, and the second arc block 2002 contracts and resets.

[0064] Step S3: In the slide bar pressing unit 4005, align the slide bar with the slide bar sealing ring with the hollow cavity of the plug housing with the outer peripheral sealing ring. The servo press drives the pressing head to move downward and press the slide bar smoothly into the hollow cavity. The pressing depth is monitored by the displacement sensor.

[0065] Step S4: In the third assembly unit, the spring has been pre-placed in the hollow cavity of the plug housing. The snap ring supply device 3003 delivers the open snap ring to the discharge position. The drive device 3004 moves the double-stage coaxial pressure head assembly 3001 directly above the discharge position. The Z-axis lifting mechanism 3042 drives the pressure head assembly downwards, and the lower end of the central guide shaft 3011 passes through the inner hole of the open snap ring. Under its own elastic restoring force, the open snap ring retracts and embeds into the snap ring limiting groove 3111. The drive device 3004 moves the double-stage coaxial pressure head assembly 3001 with the embedded open snap ring directly above the assembly station. The washer holding device 3002 holds the washer directly above the hollow cavity of the plug housing. At this time, the axis of the double-stage coaxial pressure head assembly 3001, the axis of the washer, and the axis of the hollow cavity of the plug housing coincide. The Z-axis lifting mechanism 3042 drives the double-stage coaxial pressure head assembly 3001 downwards smoothly. The central guide shaft 3011 first passes downward through the inner hole of the washer and directly inserts into the hollow cavity of the plug housing, providing centering guidance and effectively resisting the uneven upward reaction force of the spring inside the cavity. Subsequently, the outer pressing cylinder 3012 descends, its lower end contacting the portion of the open retaining ring protruding from the outer circumference of the central guide shaft 3011, pushing the open retaining ring out of the retaining ring limiting groove 3111, and simultaneously pushing the washer and open retaining ring downward along the central guide shaft 3011 into the hollow cavity. When the open retaining ring reaches the axial position of the pre-reserved groove on the inner wall, the open end of the open retaining ring expands outward under its own elastic action, springing into the groove to complete the locking. Throughout the pressing process, the pressure sensor detects the reaction force in real time and generates a displacement-pressure curve. The judgment module determines whether the assembly is qualified based on the characteristic fluctuation inflection point.

[0066] This system establishes a complete quality data flow throughout the entire assembly process. The first assembly unit is equipped with a first quality inspection sensor to detect appearance defects or dimensional deviations after the outer circumferential sealing ring is assembled. The inspection data is then linked to the current fixture 4002 number or the product's unique identifier and uploaded to the central controller of the data linkage control system. The second assembly unit is equipped with a second quality inspection sensor to detect appearance defects or dimensional deviations after the slide bar sealing ring is assembled, and similarly uploads the inspection data to the central controller. The displacement-pressure curve generated by the pressure sensor in the third assembly unit and the judgment results from the judgment module are also uploaded to the central controller. Displacement sensor data from the slide bar pressing unit 4005, rebound force values ​​from the rebound force detection unit 4006, and leakage rate data from the airtightness detection unit are all uploaded to the central controller in a unified data format. The central controller uses the fixture 4002 number or the product's unique identifier as an index key to aggregate and correlate all quality data from each assembly unit and each detection unit, forming a full lifecycle quality data archive indexed by a single product. This quality data archive can be retrieved and traced via QR codes engraved on the product surface using a laser marking machine or identification codes read by a barcode scanner. When any detection data received by the central controller exceeds a preset threshold, the central controller sends a control command to the corresponding assembly unit or subsequent assembly unit to mark the workpiece, skip subsequent processes, or reject it, preventing defective products from continuing to occupy processing resources in subsequent processes. This end-to-end data linkage control elevates the physical coupling of the three assembly units from a mechanical level to an information-level quality closed loop, ensuring that the end-to-end assembly quality data of every product leaving the factory is traceable. In a further preferred embodiment, the data linkage control system also includes a host computer running MES or production management software to perform statistical analysis, trend warnings, and report generation on the data collected by the central controller, providing data support for process optimization and quality management.

[0067] It is understood that the above embodiments are described in the form of a production line consisting of a first assembly unit, a second assembly unit, and a third assembly unit connected in series. However, the plug multi-component collaborative fully automated assembly and online testing production line of the present invention is not limited to the working mode in which the three assembly units must be physically connected in series. In another embodiment, the first assembly unit, the second assembly unit, and the third assembly unit can each be used independently as a workstation, and the workpiece is transferred between the workstations by manual or automated guided vehicles. In this case, the first assembly unit can independently complete the precision assembly of the outer circumferential sealing ring of the plug shell. Its core function of using the first arc block 1042 to fit a seamless cylindrical surface to open the sealing ring and the first pusher sleeve 1044 to demold without shrinkage operates independently of other assembly units. Similarly, the second assembly unit can independently complete the precision assembly of the slide bar seal ring. Utilizing the seamless cylindrical outer wall formed by the splicing of two second arc blocks 2002 and the independently driven second pusher sleeve 2003, it achieves non-destructive opening and non-shrinkage demolding of the slide bar seal ring. Its quick-change module 2004 allows the second assembly unit to still have the ability to quickly change shapes within minutes when used alone. The third assembly unit can independently complete the precision pressing of the retaining ring washer within the spring cavity. Utilizing the dual-stage coaxial pressure head assembly 3001, which uses a two-stage guiding logic—first entering and centering with the central guide shaft 3011, and then pushing with the outer pressing cylinder 3012—it overcomes the skewing caused by spring reaction force. Furthermore, it achieves online non-destructive full inspection of each product through pressure sensors and a judgment module. When each assembly unit works independently, its respective power mechanism 1043, drive mechanism 2005, drive device 3004, and control system can all operate independently, without relying on the presence or cooperation of other assembly units. In this independent working mode, the beneficial effects of each assembly unit include: the first assembly unit, when used alone, can eliminate the expansion damage to the outer peripheral seal ring and demolding scratches; the second assembly unit, when used alone, can eliminate the expansion damage to the slide bar seal ring and demolding scratches, and has rapid changeover capability; the third assembly unit, when used alone, can overcome the misalignment of the snap ring press caused by the spring reaction force, and achieve online full inspection. This independent working mode allows the system to be flexibly configured for manufacturing scenarios with different production scales: for production lines with smaller capacity requirements, only one or two assembly units can be configured, and the remaining processes can be completed manually or with conventional equipment; for production lines with larger capacity requirements, the three assembly units can be connected in series through a segmented conveyor line 4001 to form a fully automated production line. In another embodiment, any two of the three assembly units can be combined to form a partially automated production line, with the remaining processes completed by independent workstations, thus achieving a flexible balance between automation level and equipment investment.

[0068] The core of this invention lies in overcoming several long-standing technical biases in the field. Bias 1: It is generally believed that the sealing ring opening assembly mechanism must radially retract during demolding to allow for proper positioning; otherwise, the opening component will prevent the sealing ring from falling into the workpiece's stepped groove. This invention, through an independently driven pusher sleeve, pushes the sealing ring axially and evenly away while the opening component remains expanded, completely avoiding the scratching and misalignment problems caused by shrinkage demolding, contrary to traditional understanding. Bias 2: It is generally believed that in the press-fitting of the retaining ring within the spring cavity, the uneven upward reaction force of the spring is a detrimental factor causing part misalignment, requiring a fixed mandrel from below to counteract it. This invention, through a central guide shaft inserted into the cavity from above, transforms the unfavorable factor of the spring reaction force into a stable auxiliary force that presses the washer and retaining ring outwards into the lower end face of the cylinder, achieving a breakthrough in understanding that transforms a disadvantage into an advantage. Bias 3: It is generally believed that in multi-lobed opening schemes, the more lobes, the better the opening uniformity. Through in-depth analysis, this invention reveals that each splicing seam is a potential point of disruption to the continuity of the cylindrical surface. While increasing the number of lobes can reduce the size of individual seams, it increases the total number of seams. The double-lobed scheme achieves the maximum degree of cylindrical surface continuity with the fewest seams, obtaining a counterintuitive optimal solution in terms of uniformity of expansion. This breakthrough in overcoming technical bias was not something that a person skilled in the art could have foreseen through conventional experiments or logical reasoning before the application date, and constitutes an inventive contribution of this invention relative to the prior art.

[0069] To verify the beneficial effects of the technical solution of this invention compared with traditional assembly methods, comparative tests were conducted under the same experimental conditions. Comparative Test 1: The traditional three-lobed metal expansion claw shrinkage demolding scheme and the quarter-circle arc block and push-sleeve assembly scheme of the first assembly unit of this embodiment were used to expand and demold the outer circumferential sealing ring, respectively. Multiple assembly tests were performed for each scheme, and the misalignment rate and surface damage of the sealing ring after assembly were recorded. The results show that the traditional scheme has a high misalignment rate due to uneven suspended force caused by the gap between the lobes and the frictional rebound during shrinkage demolding, and obvious dot-like indentations are visible on the surface of the sealing ring. The solution of this application, through continuous support across the entire circumference and uniform axial push-material, significantly reduces the misalignment rate and significantly improves the surface damage. This comparative result confirms that, in the specific technical problem of elastic sealing ring assembly, the combination of full-circumferential expansion and uniform axial push-material is not a simple superposition of two known methods, but rather produces a synergistic technical effect of reducing the misalignment rate and surface damage. Comparative Test 2: Using both the traditional step-by-step pressing method and the two-stage guided pressing method of the third assembly unit in this embodiment, washers and open retaining rings were pressed into the housing of the built-in spring. Multiple assembly tests were performed for each method, recording the success rate of the retaining ring's insertion and the consistency of the spring's compression and rebound force after assembly. The results show that the traditional method suffers from washer misalignment due to spring reaction force, resulting in an unsatisfactory success rate of retaining ring insertion and dispersed rebound force values. The proposed method, through a two-stage guidance system of first centering with the central guide shaft 3011 and then pushing with the outer pressing cylinder 3012, significantly improves the success rate of retaining ring insertion, concentrates the rebound force values, and demonstrates significantly better assembly consistency than the traditional method.

[0070] Because the expansion of the first arc block 1042 in the first assembly unit can be adjusted by changing the stroke of the conical push block or by replacing the arc block with one of different specifications to accommodate outer circumferential sealing rings with different inner diameters; the quick-change module 2004 in the second assembly unit can be directly replaced as a whole to accommodate sliding rod sealing rings of different specifications; and the outer diameters of the central guide shaft 3011 and the outer pressing cylinder 3012 of the double-stage coaxial pressure head assembly 3001 in the third assembly unit are both smaller than the inner diameter of the hollow cavity in the housing, only the clamping jaw 3211 or the double-stage coaxial pressure head assembly 3001 needs to be replaced when switching specifications. Therefore, this system has a high degree of compatibility with multiple specifications, low changeover costs, and high production flexibility.

[0071] It is understood that although the above embodiments use a water-cooled connector plug as an example to illustrate the assembly system and method of the present invention, the technical solution of the present invention is also applicable to other products with similar assembly requirements. For example, in the assembly scenario of a hydraulic valve body, the valve body also has a hollow cavity, requiring the insertion of washers and retaining rings after a spring is built into the cavity. Simultaneously, sealing rings also need to be assembled on the outer periphery of the valve body and the internal valve stem. The first assembly unit of the present invention can be used for the precision assembly of the outer periphery sealing ring of the valve body, the second assembly unit can be used for the precision assembly of the valve stem sealing ring, and the third assembly unit can be used for the two-stage guided press-fitting of the spring, washer, and retaining ring inside the valve body. In the assembly scenario of pneumatic components, the cylinder end cover also involves the assembly of the outer periphery sealing ring and the internal retaining ring. In the assembly scenario of automotive parts, products such as brake master cylinders and clutch slave cylinders all have similar multi-component precision assembly requirements. The three assembly units of this invention can be selectively configured and combined according to the assembly requirements of specific products. The number of arc blocks, the size of the push sleeve, the specifications of the pressure head assembly, and other parameters of each assembly unit can be adjusted according to the part size of different products without deviating from the core technical principle of seamless cylindrical surface expansion without shrinkage demolding and double-stage guided pressing of this invention.

[0072] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A fully automated assembly and online testing production line for multi-component plugs, characterized in that, include: The first assembly unit is equipped with a self-adaptive press-fit device (1000) for the outer circumferential sealing ring of the housing. This device includes: - Multiple first arc blocks (1042) are assembled into a first seamless cylindrical outer wall surface in an expanded state; - The first pusher sleeve (1044) is coaxially fitted around the first arc block (1042); - The first axial drive member (1045) drives the first pusher sleeve (1044) to slide axially so as to push the opened sealing ring away from the outer wall surface of the first seamless cylinder while the first arc block (1042) remains in an expanded state. The second assembly unit is equipped with a sliding rod-type sealing ring guided automatic assembly mechanism (2000), which includes: - Two symmetrically arranged second arc blocks (2002) have a guide structure (2021) on their splicing end face. In the expanded state, the guide structure (2021) guides the splicing end face to fit seamlessly, forming a second seamless cylindrical outer wall surface. - The second pusher sleeve (2003) is coaxially fitted around the second arc block (2002); - The pusher drive device (2006) is independent of the drive mechanism (2005) that drives the second arc block (2002) to expand. The pusher drive device (2006) drives the second pusher sleeve (2003) to slide axially so as to push the opened sealing ring away from the outer wall surface of the second seamless cylinder while the second arc block (2002) remains in an expanded state. The third assembly unit is equipped with a retaining ring washer air assembly and a double-stage guide pressing device (3000), which includes: - The dual-stage coaxial pressure head assembly (3001) is composed of a central front guide shaft (3011) and an outer pressing cylinder (3012) coaxially and fixedly connected. The lower end of the central front guide shaft (3011) protrudes downward from the lower end face of the outer pressing cylinder (3012). The outer peripheral surface of the central front guide shaft (3011) near the lower end is provided with a snap ring limiting groove (3111). The outer diameter of the central front guide shaft (3011) and the outer diameter of the outer pressing cylinder (3012) are both smaller than the inner diameter of the hollow cavity of the housing to be assembled. - A washer holding device (3002) holds the washer directly above the hollow cavity of the housing to be assembled, and the central axis of the held washer coincides with the central axis of the hollow cavity. The central guide shaft (3011) is configured to pass through the inner hole of the washer with clearance fit. - The driving device (3004) drives the dual-stage coaxial pressure head assembly (3001) to perform the pressing action. During pressing, the central front guide shaft (3011) is first inserted into the hollow cavity for centering and guidance. Then, the peripheral pressing cylinder (3012) moves downward to push the washer and the open snap ring embedded in the snap ring limiting groove (3111) into the hollow cavity simultaneously.

2. The fully automated assembly and online testing production line for multi-component plugs according to claim 1, characterized in that, The first assembly unit, the second assembly unit and the third assembly unit are arranged in sequence, and the assembly units are connected by a segmented conveyor line (4001). The workpiece is carried by a fixture (4002) and flows between the assembly units.

3. The fully automated assembly and online testing production line for multi-component plugs according to claim 1 or 2, characterized in that, It also includes a slide bar pressing unit (4005) disposed between the second assembly unit and the third assembly unit, for pressing the slide bar with the assembled sealing ring into the housing to be assembled.

4. The fully automated assembly and online testing production line for multi-component plugs according to claim 1, characterized in that, The sliding rod-type sealing ring guided automatic assembly mechanism (2000) of the second assembly unit also includes a quick-change module (2004). The two symmetrically arranged second arc blocks (2002) and the second pusher sleeve (2003) are integrated in the quick-change module (2004). The quick-change module (2004) is detachably connected to the vertical lifting module (2007) that drives its lifting and lowering through a detachable docking interface (2001). The detachable docking interface (2001) has an end face positioning structure and a multi-way air quick-connect connector (2011).

5. The fully automated assembly and online testing production line for multi-component plugs according to claim 1, characterized in that, The first arc block (1042) of the first assembly unit consists of four independent quarter arc blocks. In the expanded state, the sides of adjacent arc blocks are joined together to form the first seamless cylindrical outer wall surface without gaps. The second arc block (2002) of the second assembly unit consists of two symmetrically arranged semi-circular arc blocks.

6. The fully automated assembly and online testing production line for multi-component plugs according to claim 1, characterized in that, The drive mechanism (2005) of the second assembly unit is a synchronous wedge linkage mechanism, including a wedge block (2051) and a power cylinder (2052) connected to the wedge block (2051). The two inclined surfaces of the wedge block (2051) slide in contact with the inner inclined surfaces of the two second arc blocks (2002), respectively, converting the axial movement of the power cylinder (2052) into the synchronous radial movement of the two second arc blocks (2002).

7. The fully automated assembly and online testing production line for multi-component plugs according to claim 1, characterized in that, The snap ring washer air assembly and double-stage guide pressing device (3000) of the third assembly unit also includes a pressure sensor and a judgment module; the pressure sensor is connected in series between the force application end of the drive device (3004) and the double-stage coaxial pressure head assembly (3001) to detect the reaction force in real time during the pressing process and generate a displacement-pressure curve; The determination module is configured to determine whether the assembly is qualified based on the characteristic fluctuation inflection point generated when the open snap ring enters the slot in the displacement-pressure curve.

8. The fully automated assembly and online testing production line for multi-component plugs according to claim 1, characterized in that, The washer holding device (3002) of the third assembly unit includes a receiving cylinder (3021) with an openable gripper (3211). When the gripper (3211) closes, it forms a positioning hole for holding the washer. When pressed in, the outer pressing cylinder (3012) moves down to contact and push open the gripper (3211), so that the gripper (3211) gives way and releases the washer.

9. The fully automated assembly and online testing production line for multi-component plugs according to any one of claims 1 to 8, characterized in that, It also includes a spring force detection unit (4006) disposed after the third assembly unit, for detecting the compression spring force of the spring in the housing to be assembled; and / or includes an airtightness detection unit for performing airtightness detection on the finished product.

10. A method for precision assembly of multiple plug components, using a fully automated assembly and online testing production line for multiple plug components as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Step S1: In the first assembly unit, the plug housing is positioned, the first arc block (1042) is expanded and assembled into the outer wall of the first seamless cylinder to open the outer peripheral sealing ring, and the first pusher sleeve (1044) pushes the outer peripheral sealing ring away and fits it into the stepped groove of the plug housing while the first arc block (1042) is in the expanded state. In step S2, in the second assembly unit, the slide rod is positioned, the second arc block (2002) expands and is guided by the guide structure (2021) to fit the splicing end face to form the outer wall of the second seamless cylinder to open the slide rod sealing ring, and the second pusher sleeve (2003) pushes the slide rod sealing ring away and fits into the slide rod while the second arc block (2002) is in the expanded state; Step S3: Press the slide rod with the slide rod sealing ring already assembled into the hollow cavity of the plug housing; In step S4, in the third assembly unit, the central guide shaft (3011) picks up the open snap ring and embeds it into the snap ring limiting groove (3111). The central guide shaft (3011) is coaxially aligned with the washer held by the washer retaining device (3002) and the hollow cavity of the plug housing. The double-stage coaxial pressure head assembly (3001) is driven to move downward. The central guide shaft (3011) is first inserted into the hollow cavity for centering and guidance and resists the internal spring reaction force. Then, the outer pressing cylinder (3012) moves downward and pushes the washer and the open snap ring into the hollow cavity simultaneously, so that the open snap ring is engaged in the inner wall groove.

Images