A cavity sphere assembly device and method

Abstract

This invention discloses a cavity ball assembly device and method, belonging to the field of valve parts assembly tooling technology, specifically involving precision assembly tooling for balls of various valves such as ball valves and regulating valves. The device includes a base, positioning and limiting components, a guide component, a push rod component, a drive component, a dual elastic component, a linear guide rail component, and a stroke limiting component. Through the coordinated operation of pre-pressure spacing and pressure-stabilizing reset dual springs, it achieves flexible press-fitting throughout the entire process, preventing drop, preventing part damage, and automatic reset. A dual-slider common rail motion reference plus a central floating ball guide plate compensates for coaxiality deviations, ensuring stable assembly accuracy. The hinged layout near the transmission dead point enables internal closed-loop self-balancing of the press-fitting force, allowing for stable single-handed operation without additional fixing fixtures. This invention has a compact structure, can be specifically adapted to different specifications of workpieces, and is suitable for small-batch continuous production of small-to-medium-sized interference fit balls in valves, as well as new product R&D and trial production scenarios, meeting the flexible production needs of small and medium-sized valve enterprises.

Description

Technical Field

[0001] This invention belongs to the field of valve component assembly tooling technology, specifically relating to a cavity ball assembly device and method. This device is a special tooling for valve ball assembly, suitable for the precision assembly of balls in various valves such as small and medium-sized ball valves and regulating valves, and is especially suitable for small-batch continuous production of small and medium-sized interference fit balls and new product research and development trial production scenarios. Background Technology

[0002] As a core opening and closing component in fluid pipeline systems, the assembly accuracy of ball valves directly affects the sealing reliability and long-term operational stability of the system. The interference fit between the ball and the valve cavity is a critical step in ball valve assembly. Precise control of the coaxiality and pressure during the fit is essential for ensuring the ball valve's sealing performance, smooth operation, and service life.

[0003] Currently, the mainstream implementation schemes for the ball pressing process in the valve industry fall into two categories: one is automated pressing machines adapted to mass standardized production. Although this type of solution can achieve high-precision and high-efficiency continuous production, the initial equipment investment threshold is high and the customization cycle is long. It is only suitable for the mass production of mature and standardized products. For scenarios with rapid new product development and iteration and frequent product structure adjustments, the automated machines are difficult to adjust, have high iteration and transformation costs, and long delivery cycles. Enterprises face extremely high trial and error risks and time costs. At the same time, the equipment occupies a large area and is difficult to adapt to the cost budget and flexible production scenarios of small and medium-sized valve enterprises.

[0004] Another type is manual press-fitting fixtures. This type of solution is widely used by small and medium-sized valve enterprises because of its simple structure, low investment cost, flexible deployment, minimal footprint, and low modification cost when adjusting products. It is especially suitable for single-piece trial production, prototype development, after-sales maintenance, and small-batch production of single specifications.

[0005] However, in small-batch continuous production scenarios where product assembly consistency and production stability are required, existing manual pressing tooling has inherent limitations that are difficult to overcome, specifically:

[0006] First, assembly precision is highly dependent on manual labor, resulting in poor batch stability and high quality risks. Manually press-fitting the ball and valve cavity requires visual inspection or simple tools for alignment. The pressing posture and rhythm rely entirely on the operator's experience and skill. Influenced by differences in operator skill and work fatigue, the consistency of coaxiality between different batches, and even within the same batch, is difficult to guarantee. This can easily lead to quality problems such as poor valve sealing and sluggish operation, increasing rework costs and customer complaint risks.

[0007] Secondly, production efficiency improvements are limited, and the high labor cost per unit of production capacity puts significant pressure on enterprise cost control. Manual operation requires repetitive steps such as workpiece positioning, clamping, alignment adjustment, pressing, and workpiece removal. The assembly of a single workpiece is time-consuming and the production rhythm is inconsistent. In small-batch continuous production scenarios, the bottleneck of manual efficiency is significant. The low efficiency of single workpiece assembly directly leads to an increase in the number of operators required for the same production capacity, pushing up the enterprise's labor costs. Small and medium-sized valve enterprises generally lack economies of scale and brand premium, and have limited profit margins per product. They are extremely sensitive to labor costs and tooling investment costs, making it difficult to increase production capacity by continuously increasing personnel.

[0008] Third, the lack of systematic and coordinated control in the press-fitting process leads to a high risk of component damage and significant hidden costs. Even with the addition of springs to achieve simple force buffering, existing manual tooling can only optimize the press-fitting force at a single point. It cannot achieve multi-dimensional coordinated control of press-fitting force constraints, precise coaxiality control, workpiece positioning and guidance, and stroke limit limits. The force and posture during the press-fitting process cannot form a stable closed loop. Insufficient press-fitting force can easily lead to improper fit and affect sealing, while excessive force may scratch the sealing surface or cause component crushing, increasing scrap rate and rework costs, and driving up the company's long-term hidden production costs.

[0009] In summary, while existing manual pressing fixtures possess core advantages such as low cost, easy deployment, and flexible iteration, they suffer from inherent limitations in small-batch continuous production scenarios, including uncontrollable precision, low efficiency, high labor costs, and a lack of systematic collaborative management of the pressing process. Automated special-purpose machines, on the other hand, face challenges such as high investment thresholds, long customization cycles, inflexible iterative adjustments, and high trial-and-error risks. Small and medium-sized valve enterprises struggle to simultaneously achieve assembly quality, production efficiency, product iteration flexibility, and cost control within limited cost and space constraints. The industry urgently needs an assembly solution that is low-cost, requires minimal space, offers flexible iterative adjustments, and combines high-precision coaxial control, controllable flexible pressing, and multi-dimensional integrated collaborative management capabilities to overcome the core production challenges faced by small and medium-sized valve enterprises. Therefore, this invention proposes a cavity sphere assembly device and method to solve the aforementioned technical problems in an economical, efficient, and reliable manner. Summary of the Invention

[0010] The orientation and terminology used throughout this invention are uniformly defined as follows:

[0011] Orientation definition: The end of this assembly device used to receive the workpiece in the assembly cavity and push the ball is the front end, and the end of this assembly device used to install the operating handle and drive lever is the rear end; the axial direction mentioned throughout the text refers to the direction of the line connecting the front end and the rear end.

[0012] Terminology definition: The angle between the operating lever and the transmission link mentioned throughout the text refers to the angle between the center line of the front end of the operating lever and the center line of the transmission link in the plane of motion.

[0013] This invention aims to overcome the inherent limitations of existing technologies and resolve the core contradictions faced by small and medium-sized valve enterprises regarding cost, efficiency, iterative flexibility, and assembly quality. It provides a cavity sphere assembly device and method that is low-cost, occupies minimal space, allows for flexible iterative adjustments, and combines high-precision coaxial control with multi-dimensional integrated collaborative management capabilities. With extremely low investment costs, it achieves assembly accuracy and production efficiency close to that of automated equipment, making it suitable for the core scenarios of small and medium-sized valve enterprises for small-batch continuous production and new product R&D and trial production.

[0014] To achieve the above objectives, the present invention adopts the following core technical solution:

[0015] A cavity sphere assembly device includes a base, a positioning and limiting component, a guide component, a push rod component, a drive component, a dual elastic component, a linear guide rail component, and a stroke limiting component.

[0016] The base provides installation support for the entire device, featuring a compact structure and minimal footprint, allowing direct placement on a standard workbench. The positioning and limiting assembly is located at the front end of the base, used for circumferential radial positioning and assembly positioning of the cavity parts to be assembled. The guide assembly is slidably mounted on the linear guide assembly, including a push rod ball guide seat and a floating ball guide plate, which can compensate for coaxiality errors through slight radial floating. The push rod assembly is slidably mounted on the linear guide assembly, including an assembly push rod and a push rod slide, used to transmit the press-fit driving force. The drive assembly is hinged at the rear end of the base, including an operating lever, a transmission link, and a link hinge seat. The lever fulcrum and operating handle are used to convert rotational driving force into linear driving force; the dual elastic component is a dual-spring cooperative structure consisting of a pre-compression fixed-distance spring and a stabilizing reset spring, realizing flexible press-fit force control; the linear guide rail assembly includes at least one slide rail and at least two slidingly engaged sliders, used to ensure motion alignment, coaxiality, and operational stability; the stroke limit assembly includes a first stroke limit block, a second stroke limit block, an initial reset limit component, and a press-in limit component, used to precisely control the front and rear limit strokes; through the coordinated layout of the above components, a multi-dimensional closed-loop control integrating positioning guidance, coaxial control, flexible press-fitting, and stroke limit is achieved.

[0017] Furthermore, the positioning and limiting component includes a cavity positioning block and a cavity positioning limit block. The cavity positioning block is used for initial circumferential radial positioning of the cavity part to ensure assembly alignment, and the cavity positioning limit block is used to limit the assembly position of the cavity part to prevent displacement of the part during assembly.

[0018] Furthermore, the first and second travel limit blocks are respectively located on the front and rear sides of the push rod ball guide seat, cooperating with the initial reset limit component. When the device resets backward, the initial reset limit component, together with the travel limit blocks, limits the backward maximum rotational travel of the operating lever; when the device presses forward, the two travel limit blocks move freely synchronously with the push rod ball guide seat, without constraining the pressing travel; only when pressed to the limit position is the maximum rotation angle of the operating lever constrained by the pressing limit component.

[0019] Furthermore, the floating ball guide plate is positioned at the center of the ball guide seat of the push rod, working in conjunction with the assembly push rod to ensure the coaxiality of the initial position of the ball with the ball loading cavity during placement. During assembly, the ball is always constrained within a coaxiality range of ±0.03mm by the floating ball guide plate and the assembly push rod, preventing jamming due to part position deviations. The floating ball guide plate is positioned by circumferential and axial limiting structures, without radial rigid constraints, allowing for slight radial floating to compensate for coaxiality and centering errors. The circumferential and axial limiting structures are positioning pins.

[0020] Furthermore, the push rod ball guide seat is an integral structure with a guide coaxial cavity and guide inclined surface at the front end that fits with the outer periphery of the cavity part, a ball feeding cavity in the middle, and a push rod assembly guide hole inside, which can simultaneously realize the functions of ball bearing guidance, cavity coaxial centering, and push rod linear guidance.

[0021] Furthermore, the front end of the assembly push rod abuts against the outer circle of the ball to be assembled, which can limit the position of the two sides of the ball and work with the floating ball guide plate to ensure that the ball groove and the valve stem are accurately aligned; the tail end of the assembly push rod is detachably fixedly connected to the push rod slide, and the push rod slide is fixedly mounted on the slider of the linear guide assembly.

[0022] Furthermore, the operating lever and transmission link adopt a special hinged layout. When the ball is assembled and pressed into the station, the included angle between the two is 175°-180°. When the pressing ends, it is in a position close to the transmission dead point, and the pressing force reaches its peak. The operating torque has been optimized, making the operation convenient and labor-saving. The pressing force is mainly converted into a closed-loop axial thrust of internal interaction of the device, which ultimately acts on the assembly push rod. The radial and axial components of the force on the base and the worktable are minimal, and stable operation can be achieved without additional clamps.

[0023] Furthermore, the two ends of the pressure-stabilizing reset spring are respectively provided with replaceable elastic adjustment shims, and the spring pre-compression can be adjusted by increasing or decreasing the number of shims to adapt to the assembly requirements of small and medium interference ball parts of corresponding workpiece specifications.

[0024] Furthermore, the assembly push rod and push rod slide adopt a detachable structure with precise positioning and fit, and the corresponding matching parts can be replaced for workpieces of different specifications without the need for overall tooling reconstruction; the core functional components of the device adopt a modular layout, which is convenient for maintenance and has a compact and stable structure.

[0025] The present invention also provides a cavity sphere assembly method, which is implemented using the above-mentioned cavity sphere assembly device. The core steps are: reset loading, workpiece positioning, pre-fitting guidance, press assembly, and reset unloading. The entire process can be completed with a single handle.

[0026] Compared with existing technologies, this invention has the following outstanding substantive features and significant progress, effectively breaking the core production dilemma of small and medium-sized valve enterprises:

[0027] First, it achieves multi-dimensional closed-loop control, completely resolving the inherent defects of existing tooling single-point optimization. This invention, through the coordinated layout of positioning and limiting components, guiding components, dual elastic components, linear guide rail components, and stroke limiting components, systematically integrates workpiece positioning and guidance, precise coaxiality control, flexible press-fitting force control, and stroke limit limiting, achieving closed-loop control of the entire press-fitting process, rather than the single-point optimization of existing technologies. This fundamentally solves the core pain point of unstable posture and force values ​​during the press-fitting process.

[0028] Secondly, assembly accuracy and batch stability are significantly improved, completely eliminating reliance on manual labor. This invention ensures basic coaxiality and alignment through a dual-slider common-rail motion reference, coupled with a dual coaxiality guarantee mechanism that compensates for alignment deviations by radial micro-floatation of floating ball guide plates. Stable coaxiality control can be achieved without repeated manual alignment adjustments, completely solving the core pain points of existing manual tooling that rely on manual precision and have poor batch stability. It significantly reduces the risk of parts scratching and damage, and greatly improves the yield and delivery stability of small and medium batch continuous production.

[0029] Third, it significantly improves assembly efficiency, effectively reduces labor costs, and alleviates production capacity pressure for enterprises. This invention adopts a single-handle integrated operation design, allowing the entire pressing process to be completed with a single workpiece positioning. There is no need for repeated clamping or repetitive alignment adjustments, which greatly shortens the assembly time for a single workpiece, ensures a unified and stable production rhythm, and significantly reduces the number of operators required for the same production capacity. This effectively reduces enterprise labor costs, alleviates production capacity pressure for small-batch continuous production, and achieves capacity improvement without increasing personnel.

[0030] Fourth, the entire process of flexible press fitting is controllable, reducing hidden production costs at the source. This invention forms a layered collaborative force control mechanism through a special layout of pre-compression fixed-distance springs and pressure-stabilizing reset springs. This mechanism works in conjunction with coaxial guides and stroke limits to achieve precise force control of fixed-distance pre-tightening, pressure stabilization and buffering, and automatic reset throughout the pre-fitting, press fitting, and reset processes. This completely solves the pain point of existing manual tooling press fitting without stable closed-loop control of force, avoids damage to the workpiece caused by rigid tops and force fluctuations, significantly reduces the scrap rate of parts and rework costs, and significantly reduces the hidden production costs of enterprises.

[0031] Fifth, it offers flexible iteration and adjustment with extremely low trial-and-error costs, making it suitable for new product development scenarios. The core functional components of this invention adopt a modular and detachable design. When adjusting the product structure or iterating specifications, only the corresponding positioning, guiding components, and assembly push rods need to be replaced to complete the tooling adaptation. There is no need to reconstruct the main structure of the device. The iteration and modification costs are low, and the adjustment cycle is short, which greatly reduces the trial-and-error risks and time costs of new product development, perfectly adapting to production scenarios with frequent product iterations.

[0032] Sixth, it features a compact structure, minimal footprint, and extremely low investment cost, making it suitable for the budgets of small and medium-sized enterprises. The invention boasts a streamlined overall structure, with an investment far lower than that of automated press-fitting machines. Its small size and minimal footprint allow it to be placed directly on a standard workbench, requiring no dedicated space or fixed installation. It fully inherits the core advantages of traditional manual tooling—low cost and easy deployment—while completely overcoming the inherent limitations of manual tooling. This helps small and medium-sized valve enterprises achieve multiple improvements in assembly quality, production efficiency, and iterative flexibility within a limited cost budget. Attached Figure Description

[0033] Figure 1 Overall isometric structural schematic diagram of the present invention

[0034] Figure 2 Another perspective is the isometric structural schematic diagram of this invention.

[0035] Figure 3 Full cross-sectional view of the present invention in the press-fitted state.

[0036] Figure 4 A partially enlarged sectional view of the initial state of the front-end assembly station of this invention.

[0037] Figure 5 A partially enlarged sectional view of the front-end assembly station in the press-fitting state of this invention.

[0038] The corresponding reference numerals and component names in the attached drawings are as follows:

[0039] 1-Base

[0040] 2-Cavity positioning limit block

[0041] 3-Cavity positioning block

[0042] 4-Pushstick ball guide seat

[0043] 401-Guide Coaxial Cavity

[0044] 402-Guide Inclined Surface

[0045] 403 - Spring Mounting Hole

[0046] 404-Spherical Feeding Chamber

[0047] 5-Floating Sphere Guide Plate

[0048] 6-Push Rod Slide

[0049] 7- Assemble the push rod

[0050] 8-Connecting rod

[0051] 9-Linkage Hinge Seat

[0052] 10-Operating Lever

[0053] 11-Lever fulcrum seat

[0054] 12-First Stroke Limit Block

[0055] 13-Second Stroke Limit Block

[0056] 14-Buffer pad

[0057] 15-Slide rail

[0058] 16-Slider

[0059] 17-Hinged Shaft

[0060] 19-Operating handle

[0061] 20-Voltage Regulating Reset Spring

[0062] 21-Elastic Adjustment Shim

[0063] 22-Equal Height Bolt

[0064] 23-Metal Washer

[0065] 24-Preloaded fixed-distance spring

[0066] 31-Initial Reset Limiting Component

[0067] 32-Press-in limit stop

[0068] 38-Sphere

[0069] 39-Workpiece to be assembled into a cavity

[0070] 3901 - Workpiece spherical receiving cavity

[0071] 40-valve stem Detailed Implementation

[0072] The present invention will be further described in detail below with reference to the accompanying drawings. The described embodiments are preferred embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0073] The cavity ball assembly device provided in this embodiment is a special device for assembling ball valves of corresponding specifications. The core components adopt a modular layout and are installed on a long strip of 6061 aluminum alloy base 1. Other metal materials such as 304 stainless steel and 45 steel can also be used. The surface of the base 1 is anodized to provide stable installation support for all components. The overall structure is compact, small in size and occupies very little space. It can be directly placed on a regular workbench without the need for additional clamps and does not occupy a dedicated production space.

[0074] The positioning and limiting assembly is located at the front end of the base 1 and is positioned by positioning pins and fixed by fastening screws. It includes a cavity positioning block 3 and a cavity positioning limit block 2, both of which are made of 304 stainless steel. The upper end of the cavity positioning block 3 has a square positioning groove that matches the outer periphery of the cavity part of the corresponding specification. The end face edge is chamfered at 30° and polished to achieve the initial introduction and precise circumferential and radial positioning of the cavity workpiece 39 to be assembled, ensuring the alignment of the assembly. The cavity positioning limit block 2 is located at the front end of the cavity positioning block 3. Its limiting end face is aligned with the assembly reference end face of the cavity workpiece 39 to be assembled, which is used to limit the assembly position of the cavity part and prevent the part from moving forward or backward during the assembly process.

[0075] The slide rail 15 of the linear guide rail assembly is fixedly installed in the middle of the upper end face of the base 1 along the front-back direction of the base 1 by fastening screws. The slide rail is provided with positioning pins on the side for precise positioning against the surface. In this embodiment, a slide rail 15 and two slidingly engaged sliders 16 are used. The two sliders 16 are arranged in front and back along the length of the slide rail 15 and are fixedly connected to the bottom of the push rod ball guide seat 4 and the push rod slide seat 6, respectively. The sliders themselves have positioning pin holes. The two are precisely positioned by pins to ensure the centering, coaxiality and running stability of the two movements, and to ensure the coaxiality of the assembly from the motion reference level.

[0076] The guiding assembly includes a push rod ball guide seat 4 and a floating ball guide plate 5. The push rod ball guide seat 4 is an integral 304 stainless steel structure, or it can be made of other wear-resistant materials with surface hardening treatment. Its lower end is fixedly connected to the front slider 16 by screws. The front end is provided with a guide coaxial cavity 401 and a guide inclined surface 402 that fits against the outer periphery of the cavity part of the corresponding specification. The middle part is provided with a ball feeding cavity 404, and the interior is provided with a guide hole that fits with the assembly push rod 7 with clearance. It can simultaneously realize the triple functions of ball bearing guidance, cavity coaxial centering, and push rod linear guidance. The floating ball guide plate 5 is a wear-resistant thin plate structure. Its front end is adapted to the internal structure of the cavity. During press-fitting, it can approach the valve stem 40 to ensure that the ball is smoothly introduced and transitioned to the valve stem without falling off during the press-in process. The floating ball guide plate 5 is set in the center of the push rod ball guide seat 4, and its center surface coincides with the axis of the assembly push rod 7 to ensure the centering of the two.

[0077] The floating ball guide plate 5 is positioned using circumferential and axial limiting structures: In this embodiment, two positioning pins are used for limiting, and axial limiting is achieved through the pin holes inside the push rod ball guide seat 4. A floating gap of 0.04mm is reserved in the radial direction. Without radial rigid constraint, a radial micro-float of ±0.02mm can be achieved to compensate for coaxiality and centering errors, avoiding jamming due to part position deviations during assembly. Prototype testing has verified that this floating range can achieve stable coaxiality control and effectively avoid scratch damage to parts.

[0078] The front end of the assembly push rod 7 of the push rod assembly passes through the guide hole of the push rod ball guide seat 4 and abuts against the outer circle of the ball 38 to be assembled, which can limit the front and rear sides of the ball and work together with the floating ball guide plate 5 to ensure the precise alignment of the ball groove and the valve stem 40; the tail end of the assembly push rod 7 and the push rod slide 6 adopt a detachable structure with precise positioning, and the corresponding matching assembly push rod can be replaced for different specifications of workpieces. The lower end of the push rod slide 6 is fixedly connected to the rear slider 16 by a pin and screw.

[0079] The lever fulcrum seat 11 of the drive assembly is vertically fixed to the upper rear end of the base 1 by screws and positioning pins. The middle part of the operating lever 10 is hinged to the upper end of the lever fulcrum seat 11 through the hinge shaft 17. The two ends of the transmission link 8 are respectively hinged to the rear end of the link hinge seat 9 and the push rod slide 6 through the hinge shaft. The operating handle 19 is fixedly installed at the rear end of the operating lever 10 by threads to receive manual operating force. The operating lever 10 and the transmission link 8 adopt a special hinge layout. When the assembly press-in station is in place, the angle between the two is 175°-180°. When the press-in is terminated, it is in a position close to the transmission dead point, and the press-in force reaches its peak. The operating torque during the non-press-in stroke is optimized, making operation convenient and labor-saving. The press-in force is mainly converted into a closed-loop axial thrust of internal interaction of the device, which finally acts on the assembly push rod 7. The radial and axial components of the base 1 and the worktable are very small, and stable operation can be achieved without additional clamps.

[0080] The dual elastic component is a dual-spring cooperative structure consisting of a preloaded distance spring 24 and a pressure-stabilizing reset spring 20. The preloaded distance spring 24 is sleeved on the outside of the push rod ball guide seat 4, with its two ends respectively abutting the limiting step inside the spring mounting hole 403 at the rear end of the push rod ball guide seat 4 and the front end face of the metal washer 23. The metal washer 23 can slide on the rod of the equal-height bolt 22. The push rod slide seat 6 has an equal-height bolt clearance hole, the diameter of which is smaller than the outer diameter of the metal washer 23. This allows for fixed distance control by spring force during clamping and a larger distance separation during reset. The preloaded distance spring 24 provides a flexible preload thrust to push the push rod ball guide seat 4 into contact with the stroke limiting component and into the cavity. A safety gap of 0.1-0.3mm is maintained at the end face of the part to guide the cavity parts to slide smoothly into the guide coaxial cavity 401, avoiding hard pushing or hard pushing that could cause scratches and damage to the parts. At the same time, in the initial state, the floating ball guide plate 5 and the assembly push rod 7 cooperate to form a limiting contact space, forming a limit at the rear end of the ball loading cavity 404 to prevent the ball from falling out of the ball loading cavity 404. The pressure stabilizing and reset spring 20 is sleeved on the outside of the transmission connecting rod 8, with its two ends abutting against the front end of the connecting rod hinge seat 9 and the rear end hinge seat of the push rod slide 6, respectively, to provide a stable pressing force and avoid hard pushing that could damage the parts. At the same time, after the assembly is completed, the spring force is released, and the drive device automatically resets when the operating handle 19 is pulled back.

[0081] The pressure-stabilizing reset spring 20 is provided with replaceable spring force adjustment shims 21 at both ends. The pre-compression of the spring can be adjusted by increasing or decreasing the number of shims to meet the assembly requirements of small and medium interference ball parts of corresponding workpiece specifications.

[0082] The first stroke limiting block 12 and the second stroke limiting block 13 of the stroke limiting assembly are respectively located on the front and rear sides of the push rod ball guide seat 4, and cooperate with the initial reset limiting component 31. The initial reset limiting component 31 and the pressing limit limiting component 32 are fixed to the side of the base 1 by nut posts, respectively limiting the front and rear limit strokes of the operating lever 10. When the device resets backward, the initial reset limiting component 31 cooperates with the corresponding stroke limiting block to limit the rearward limit rotation stroke of the operating lever 10, ensuring that sufficient workpiece loading space is reserved after the device resets. When the device presses forward, the two stroke limiting blocks move freely synchronously with the push rod ball guide seat 4, without constraining the pressing stroke. Only when the pressing reaches the limit position is the pressing limit limiting component 32 constrained by the maximum rotation angle of the operating lever 10 to prevent the lever from crossing the transmission dead point and ensure stable output of the maximum pressing force. Preferably, the limiting end face of the stroke limiting assembly can be provided with a buffer pad 14 to reduce the contact impact and reduce operating noise, or a rigid limiting end face can be directly used to achieve the limiting function.

[0083] The cavity sphere assembly method described in this embodiment includes the following steps:

[0084] 1. Reset loading: Pull the operating handle 19 backward to the limit position of the initial reset limit piece 31, and the device returns to the initial position, leaving space for loading the ball and the workpiece.

[0085] 2. Workpiece positioning: Place the workpiece 39 to be assembled into the square positioning groove of the cavity positioning block 3, with the front end abutting against the cavity positioning limit block 2 to complete the circumferential radial positioning, and place the ball 38 to be assembled into the ball feeding cavity 404 of the push rod ball guide seat 4.

[0086] 3. Pre-fitting guide: Move the operating handle 19 forward, and drive the push rod slide 6 to move forward along the slide rail 15 through the transmission link 8. The push rod slide 6 pushes the push rod ball guide seat 4 to fit into the stroke limit component through the pre-compression distance spring 24, and guides the cavity parts to slide smoothly into the guide coaxial cavity 401 to complete the coaxial alignment.

[0087] 4. Press-fit assembly: Continue to operate the handle 19 to the constraint position of the press-in limit limit piece 32. The push rod slide 6 compresses the pre-compression distance spring 24 to ensure stable workpiece positioning and ensure the coaxiality of the process of the ball entering the workpiece ball receiving cavity 3901 and the process of pressing in the valve stem, so as to avoid product scratches. At the same time, it drives the assembly push rod 7 to push the ball 38 to complete the press-fit. The floating ball guide plate 5 compensates for the coaxiality error through radial floating, avoids part wear, and ensures assembly accuracy.

[0088] 5. Reset and unloading: Pull the operating handle 19 backward. The first stroke limit block 12 and the second stroke limit block 13 work together to limit the push rod ball guide seat 4 and the push rod slide seat 6 to move back to the initial position. The pressure stabilizing reset spring 20 releases its elastic force, and the drive device automatically resets to the initial position. The workpiece can then be removed and the next assembly cycle can begin.

[0089] For workpieces of different specifications and structures, tooling adaptation can be completed simply by replacing the corresponding modular components such as cavity positioning blocks, assembly push rods, and floating ball guide plates. There is no need to reconstruct the main structure of the device. The iteration and adjustment cycle is short, the transformation cost is low, and it is suitable for production scenarios with frequent product iterations and multiple specifications in small batches.

[0090] Those skilled in the art should understand that the present invention is not limited to the above embodiments. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A cavity sphere assembly device, characterized in that, It includes a base, positioning and limiting components, guide components, push rod components, drive components, dual elastic components, linear guide rail components, and stroke limiting components; The positioning and limiting component is located at the front end of the base and is used for circumferential radial positioning and assembly positioning of the cavity parts to be assembled. The guide assembly is slidably mounted on the linear guide assembly, including a push rod ball guide seat and a floating ball guide plate. The push rod ball guide seat is used to realize the synchronous guidance of the assembled push rod and the ball to be assembled. The floating ball guide plate is limited in the middle of the push rod ball guide seat and can radially float slightly to compensate for coaxiality error, ensuring the coaxiality of the ball and the cavity mounting hole, and the alignment of the ball groove and the valve stem boss. The push rod assembly is slidably mounted on the linear guide assembly, and includes an assembly push rod and a push rod slide. The assembly push rod is used to push the ball to move, and the push rod slide is used to connect the assembly push rod and the drive assembly. The drive assembly is hinged at the rear end of the base and includes an operating lever, a transmission link, a link hinge seat, a lever fulcrum seat, and an operating handle. The operating lever is hinged on the lever fulcrum seat, and the two ends of the transmission link are respectively hinged to the operating lever and the push rod slide, which is used to convert the rotational driving force into the linear driving force of the push rod slide. The dual elastic component is a dual-spring cooperative structure consisting of a pre-compression fixed-distance spring and a pressure-stabilizing reset spring. The pre-compression fixed-distance spring is sleeved on the push rod ball guide seat to provide a flexible pre-tightening thrust, pushing the push rod ball guide seat to fit into the stroke limit component, maintaining a safe gap with the end face of the cavity part, and guiding the cavity part to smoothly slide into the guide coaxial cavity of the push rod ball guide seat, avoiding hard pushing or hard pressing that could cause scratches and damage to the part, while maintaining the preset distance between the push rod ball guide seat and the push rod slide to prevent the ball from falling off; the pressure-stabilizing reset spring is sleeved on the transmission connecting rod to provide a stable pressing force, avoiding hard pressing that could damage the part, and the drive device automatically resets when the operating handle is pulled back; The linear guide assembly includes at least one slide rail and at least two slidingly engaged sliders. The slide rail is fixedly arranged along the front-back direction of the base, and the sliders are respectively connected to the push rod ball guide seat and the push rod slide seat to ensure motion alignment, coaxiality and stability. The stroke limiting component includes a first stroke limiting block, a second stroke limiting block, an initial reset limiting component, and a pressing limit limiting component. The initial reset limiting component is used to limit the backward limit stroke of the operating lever to ensure the preset feeding distance between the push rod ball guide seat and the assembly push rod and the workpiece feeding space. The pressing limit limiting component is used to limit the forward limit stroke of the operating lever to avoid the lever going past the dead point, which would cause the pressing stroke to shorten and the force value to decrease.

2. The cavity sphere assembly device according to claim 1, characterized in that, The positioning and limiting assembly includes a cavity positioning block and a cavity positioning limit block. The cavity positioning block is used for initial circumferential radial positioning of the cavity part to ensure assembly alignment, and the cavity positioning limit block is used to limit the assembly position of the cavity part to prevent displacement of the part during assembly.

3. The cavity sphere assembly device according to claim 1, characterized in that, The first stroke limit block and the second stroke limit block are respectively located on the front and rear sides of the push rod ball guide seat, and cooperate with the initial reset limit component. When the device resets backward, the initial reset limit component and the stroke limit block limit the backward maximum rotation stroke of the operating lever. When the device presses forward, the two stroke limit blocks move freely synchronously with the push rod ball guide seat, and do not constrain the pressing stroke. Only when the device is pressed to the limit position, the maximum rotation angle of the operating lever is constrained by the pressing limit component.

4. The cavity sphere assembly device according to claim 1, characterized in that, The floating ball guide plate is located at the center of the ball guide seat of the push rod. It works in conjunction with the assembly push rod to limit the radial displacement of the ball, ensuring the coaxiality of the ball and the workpiece to be assembled, and avoiding jamming due to part position deviation during assembly. The floating ball guide plate is positioned by circumferential and axial limiting structures. It has no radial rigid constraint and can achieve slight radial floating to compensate for coaxiality and centering errors. The circumferential and axial limiting structures are positioning pins.

5. The cavity sphere assembly device according to claim 1, characterized in that, The preloaded fixed-distance spring is sleeved on the outside of the push rod ball guide seat, with its two ends abutting the limiting step at the rear end of the push rod ball guide seat and the front end face of the metal washer, respectively. The metal washer can slide on the rod of the equal-height bolt. The push rod slide has an equal-height bolt clearance hole with a diameter smaller than the outer diameter of the metal washer.

6. The cavity sphere assembly device according to claim 1, characterized in that, The push rod ball guide seat is an integral structure. The front end is provided with a guide coaxial cavity and guide inclined surface that fits with the outer periphery of the cavity part, and the middle part is provided with a ball feeding cavity. The interior is provided with a push rod assembly guide hole, which can simultaneously realize the functions of ball bearing guidance, cavity coaxial centering, and push rod linear guidance.

7. The cavity sphere assembly device according to claim 1, characterized in that, The front end of the assembly push rod abuts against the outer circle of the ball to be assembled, which can limit the position of the two sides of the ball and work with the floating ball guide plate to ensure that the ball groove and the valve stem are accurately aligned; the tail end of the assembly push rod is detachably fixedly connected to the push rod slide, and the push rod slide is fixedly mounted on the slider of the linear guide assembly.

8. The cavity sphere assembly device according to claim 1, characterized in that, The operating lever and transmission link adopt a hinged layout close to the transmission dead point. When the assembly press-in station is used, the included angle between the two is 175°-180°. The pressing force is mainly converted into a closed-loop axial thrust of interaction within the device, which ultimately acts on the assembly push rod. The radial and axial components of the force on the base and the worktable are very small, and stable operation can be achieved without additional clamps.

9. The cavity sphere assembly device according to claim 1, characterized in that, The pressure-stabilizing reset spring is equipped with replaceable elastic adjustment shims at both ends. The spring pre-compression can be adjusted by increasing or decreasing the number of shims, which is suitable for assembling small to medium interference ball parts of corresponding workpiece specifications. The assembly push rod and push rod slide adopt a detachable structure with a precision positioning and threaded connection, which can be quickly replaced to adapt to different workpiece specifications. The core functional components of the device adopt a modular layout, which is convenient to maintain and has a compact and stable structure.

10. A method for assembling a cavity sphere, characterized in that, The cavity ball assembly device according to any one of claims 1 to 9 is implemented by the following steps: pulling the operating handle backward to the limit position of the initial reset limiting component, so that the device returns to the initial working position, reserving space for loading the ball and the workpiece; placing the cavity part on the positioning limiting component to complete the positioning; placing the ball to be assembled into the ball loading cavity of the push rod ball guide seat; pulling the operating handle forward, driving the push rod slide forward along the slide rail of the linear guide assembly through the transmission linkage; the push rod slide pushes the push rod ball guide seat and the stroke limiting component into place through the pre-compressed distance spring. Maintain a safe clearance with the end face of the cavity part to guide the cavity part to slide smoothly into the guide coaxial cavity of the push rod ball guide seat; continue to move the operating handle to the constraint position of the pressing limit limit piece, the push rod slide compresses the pre-compression fixed distance spring, and drives the assembly push rod to push the ball to complete the pressing. The floating ball guide plate compensates for coaxiality error through radial floating, and at the same time avoids the wear of parts caused by jamming and sliding friction during the assembly process, ensuring assembly accuracy; pull the operating handle back, the pressure stabilizing reset spring drive device automatically resets to the initial position, and the workpiece can be removed to enter the next assembly cycle.

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