A valve shell assembling and welding device based on pre-tightening clamping structure

Abstract

The present application relates to valve processing technical field, and discloses a kind of valve shell assembly welding device based on pre-tightening clamping structure, including rack with electric guide rail, valve shell assembled in electric guide rail mobile end and with laser welding piece clamping mechanism, clamping mechanism includes concentric shaft with electric push rod in inside, pre-tightening piece and clamping piece.The present application is with concentric shaft as overall reference, by pre-tightening piece, clamping piece division cooperation, first, utilize positioning portion to complete flange rough positioning, then by the radial pre-tightening calibration of flange to the pair of abutting block, again by abutting block two from inside to support tightly valve shell port, force flange, valve shell and concentric shaft three axis keep coincident.Meanwhile, calibration shaft and calibration hole form mechanical check structure, ensure that circumferential each place top travel, stress uniform, completely overcome traditional tool butt joint when coaxiality deviation, butt joint wrong side, assembly gap uneven defects.

Description

Technical Field

[0001] This invention relates to the field of valve processing technology, and more specifically to a valve housing assembly and welding device based on a pre-tightening snap-fit ​​structure. Background Technology

[0002] Valves, as core control components in fluid pipeline systems, are widely used in many industries such as water supply and drainage, thermal power generation, petrochemicals, and long-distance pipelines. According to their structural forming methods, valve shells are mainly divided into two categories: integral casting and separate welded types. For valves with small to medium diameters (DN300 and below) and operating at low to medium pressure, the industry generally adopts the integral casting process for the valve body and flange. This process is simple, has low manufacturing costs, and can meet the needs of conventional operating conditions. However, in the production of large-diameter valves (DN350 and above), the integral casting process has gradually revealed significant drawbacks. The integral casting of large-diameter valve bodies requires large molds, incurs high mold-making costs, and makes casting difficult, easily leading to internal defects such as porosity, shrinkage cavities, and cracks, resulting in a high scrap rate.

[0003] In the welding and assembly process of valve bodies and flanges, snap-fit ​​positioning fixtures are core equipment for ensuring assembly and welding quality. Currently, conventional welding fixtures mostly use ordinary jaws and clamps for workpiece clamping and positioning, which generally have significant shortcomings. On the one hand, traditional snap-fit ​​structures lack a unified centering datum, making it difficult to ensure axis alignment between the flange and valve body ports during assembly. This easily leads to problems such as butt joint misalignment and uneven gaps, resulting in defects such as misalignment, incomplete welds, and slag inclusions after welding, directly affecting the valve's sealing performance and structural strength. On the other hand, most existing fixtures only perform simple clamping without pre-tightening structures, easily leaving assembly gaps on the workpiece mating surfaces. Combined with the effects of vibration and thermal stress during welding, the snap-fit ​​joints are prone to loosening, further exacerbating workpiece displacement and resulting in poor weld quality stability.

[0004] Meanwhile, traditional tooling struggles to achieve integrated operation of flange pre-positioning and valve body internal support fixation, resulting in cumbersome process connections and low overall operational efficiency, failing to meet the demands of high-volume, high-precision valve body welding production. Therefore, developing a valve body assembly and welding device integrating pre-tightening, snap-fit, and coaxial positioning functions, relying on an integrated snap-fit ​​mechanism to ensure precise alignment between the flange and valve body, and improving assembly accuracy and welding quality, has become a pressing technical problem to be solved in this field. Summary of the Invention

[0005] To address the aforementioned shortcomings of existing technologies, this invention provides a valve housing assembly and welding device based on a pre-tightening snap-fit ​​structure. Using a concentric shaft as the overall reference, the device employs pre-tightening and snap-fit ​​components in a coordinated manner. First, the positioning part performs rough positioning of the flange. Then, a pair of clamping blocks perform radial pre-tightening calibration on the flange. Finally, a second clamping block internally tightens the valve housing port, forcing the flange, valve housing, and concentric shaft to maintain their axes of coincidence. Simultaneously, a calibration shaft and calibration holes form a mechanical verification structure, ensuring uniform clamping stroke and force distribution throughout the circumferential direction, thus improving the basic welding accuracy from the source. This effectively solves the problems of low coaxiality, large misalignment, and easy displacement and deformation during the welding process in traditional welding devices.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] The present invention provides a valve housing assembly and welding device based on a pre-tightening snap-fit ​​structure, including a frame with an electric guide rail, a valve housing assembled on the moving end of the electric guide rail, and a snap-fit ​​mechanism with laser welding parts. The snap-fit ​​mechanism includes a concentric shaft with an internal electric push rod, a pre-tightening part, and a snap-fit ​​part.

[0008] The pre-tightening component includes an annular frame that coincides with the axis of the concentric shaft. The annular frame is provided with several positioning parts and several abutting blocks. The positioning parts are used to position and support the flange, and the abutting blocks are driven to move radially by an electric push rod and abut against the inner surface of the flange to achieve precise positioning of the flange.

[0009] The snap-fit ​​component includes several clamping blocks 2. After the pre-tightening component completes the flange pre-tightening, the several clamping blocks 2 are driven to move radially by an electric push rod and abut against the inner surface of the valve body port, so that the axes of the concentric shaft, flange and valve body coincide.

[0010] The laser welding component includes an annular guide rail and a laser welding head that moves in annular motion along the annular guide rail. The laser welding head is used to weld the annular weld between the flange and the valve body.

[0011] Furthermore, the moving end of the electric guide rail is fixed with a mounting base, and the top of the mounting base is provided with a positioning groove D that matches the number of legs of the valve housing base;

[0012] An electric locking plate is installed on the mounting base. The locking part of the electric locking plate can extend to the top of the base support leg to press down and lock the base support leg embedded in the positioning groove D.

[0013] After the base support leg is embedded in the positioning groove D, an adjustment gap is reserved between the outer wall of the support leg and the groove wall to allow the valve body to achieve four-way micro-position fine adjustment.

[0014] Furthermore, the annular frame is fixed to the outer surface of the concentric shaft by a fixed bracket, and several positioning parts are fixed in an annular shape at equal intervals on the side of the annular frame. The positioning parts are rod-shaped structures and are inserted into the mounting holes of the flange to complete the rough positioning of the flange.

[0015] The ring frame has several grooves equidistantly spaced along the radial direction. Several abutting blocks are slidably assembled inside the grooves. The abutting end of the abutting block is set in a stepped shape to abut against the corner of the inner surface of the flange.

[0016] Furthermore, each of the positioning parts has a calibration hole J inside, and each of the clamping blocks has a calibration shaft fixed on it; when the clamping block moves radially and abuts against the inner surface of the flange, the calibration shaft is inserted into the calibration hole J to complete the position calibration.

[0017] Furthermore, the second abutting block is composed of a telescopic frame S1 and a telescopic block S2. The telescopic block S2 is slidably assembled inside the telescopic frame S1. An elastic layer is provided between the telescopic block S2 and the bottom of the telescopic frame S1. A rubber abutting layer is provided on the outer end face of the telescopic block S2.

[0018] Each of the telescopic sleeves S1 is fixed to the end of the concentric shaft by a telescopic frame. Several telescopic frames are arranged in a ring at equal intervals. The telescopic frame drives the two pressing blocks to move radially and press against the valve body port from the inside to the outside.

[0019] Each of the first abutment blocks is equipped with a limiting unit for locking the position of the second abutment block after radial displacement.

[0020] Furthermore, the limiting unit includes a limiting hole X, a limiting rod, and a lifting cylinder, wherein the limiting hole X is opened inside the telescopic block S2;

[0021] The limiting rod is slidably installed at the bottom of the first abutment block via a sleeve. The lifting cylinder is fixed on the first abutment block and its driving end is connected to the limiting rod. The lifting cylinder drives the limiting rod to move horizontally and insert into the limiting hole X, thereby achieving the locking and positioning of the second abutment block.

[0022] Furthermore, a sliding frame is axially slidably mounted on the concentric shaft, and a wedge-shaped transmission structure is assembled between the sliding frame and several abutting blocks.

[0023] The sliding frame is connected to the electric push rod via a spring assembly. The electric push rod axially pushes the sliding frame, and the axial motion is converted into radial motion through a wedge-shaped transmission structure, driving the clamping block to extend radially to complete the flange pre-tightening operation.

[0024] Furthermore, an axial hinge bracket is provided inside the concentric shaft. The hinge bracket includes a hinge seat and an inclined hinge rod. The hinge seat is fixed to the telescopic end of the electric push rod, and the two ends of the hinge rod are respectively hinged to the telescopic part of the hinge seat and the telescopic frame.

[0025] When the electric push rod moves axially, it drives the telescopic frame to extend and retract through the hinge rod, which in turn drives the abutment block two to move radially and abut against the inner surface of the valve body port.

[0026] Furthermore, each of the positioning parts is provided with a clamping part on the outer side that fits against the outer side of the flange, and a self-locking unit is provided inside the positioning part; the self-locking unit realizes anti-displacement self-locking during the flange support stage, and automatically retracts and resets after the pre-tightening component completes the flange pre-tightening calibration.

[0027] Furthermore, the self-locking unit includes a hidden groove inside the positioning part and three sets of T-shaped clamping frames arranged in a 120° ring.

[0028] The T-shaped clamping frame is radially slidably installed on the positioning part. An elastic anti-slip layer is provided on the contact surface of the T-shaped clamping frame. The tail of the T-shaped clamping frame extends into the hidden groove and fixes the fan-shaped block. A metal spring sheet is fixed between the fan-shaped block and the inner wall of the hidden groove.

[0029] When the flange is supported by the positioning part, the upper T-shaped clamping frame sinks under the weight of the flange, and pushes the other two sets of T-shaped clamping frames to extend radially through the wedge surface of the sector block, clamping against the inner wall of the flange mounting hole to achieve self-locking; after the flange completes the axis alignment, the metal spring drives the sector block and T-shaped clamping frame to reset, releasing the self-locking state.

[0030] The technical solution provided by this invention has the following advantages compared with the prior art:

[0031] 1. This invention uses a concentric shaft as the overall reference. Through the coordinated operation of pre-tightening and snap-fit ​​components, the positioning part first performs rough positioning of the flange, then the pair of clamping blocks perform radial pre-tightening calibration on the flange, and finally, the second clamping block internally tightens the valve body port, forcing the flange, valve body, and concentric shaft to maintain their axes coincidence. Simultaneously, a calibration shaft and calibration holes form a mechanical verification structure, ensuring uniform clamping stroke and force distribution throughout the circumference. This completely overcomes the defects of traditional tooling, such as large coaxiality deviations, misaligned edges, and uneven assembly gaps, thus improving the basic welding accuracy from the source.

[0032] 2. This invention, on the one hand, uses a combination of a mounting base, positioning groove, and electric locking plate to mechanically press down and lock the bottom legs of the valve body, limiting the overall displacement of the valve body; on the other hand, the second clamping block is equipped with an independent limiting unit, which uses the insertion and cooperation of the limiting rod and the limiting hole to achieve mechanical locking, which can resist the influence of vibration and thermal stress generated by laser welding operations and prevent the workpiece from loosening, shifting, or deforming during the welding process. In addition, the positioning part has a built-in self-weight self-locking unit, which automatically achieves anti-slip and anti-wobbling during the flange loading and support stage, ensuring the stability of the workpiece position throughout the entire process.

[0033] 3. The self-locking unit built into the positioning part of this invention can automatically lock the flange using its own weight, preventing the flange from shifting or falling and other dangers. After the flange has completed pre-tightening calibration, the self-locking can be automatically released. The structure is simplified and the operation logic is coherent. This design eliminates the need for manual assistance in fixing, simplifies the work process, and improves the overall automation level of the equipment. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of the present invention;

[0036] Figure 2 This is a schematic diagram of the fixing of the valve body of the present invention;

[0037] Figure 3 This is a schematic diagram of the valve body and flange to be welded according to the present invention;

[0038] Figure 4 This is a partial sectional view of the valve body and flange assembly of the present invention;

[0039] Figure 5 This is an exploded view of the snap-fit ​​mechanism, valve body, and flange of the present invention;

[0040] Figure 6 This is a schematic diagram of the pre-tightening of the flange by the snap-fit ​​mechanism of the present invention;

[0041] Figure 7 For the present invention Figure 6 A cross-sectional schematic diagram;

[0042] Figure 8 This is a schematic diagram illustrating the fit between the pre-tightening component and the snap-fit ​​component of the present invention;

[0043] Figure 9 This is a schematic diagram of the positioning part and flange of the present invention to be positioned;

[0044] Figure 10 For the present invention Figure 9 A schematic diagram of the radial section of the central positioning part.

[0045] The labels in the diagram represent:

[0046] 10. Frame; 11. Electric guide rail; 12. Mounting base; 13. Electric locking plate;

[0047] 20. Card receiving mechanism;

[0048] 21. Concentric shaft; 211. Electric actuator; 212. Sliding frame; 213. Wedge-shaped transmission structure; 214. Hinge bracket;

[0049] 22. Preload; 221. Ring frame; 222. Positioning part; 2221. T-shaped clamping frame; 2222. Sector block; 2223. Metal spring; 223. Clamping block one; 224. Calibration shaft;

[0050] 23. Clip-on component; 231. Second clamping block; 232. Telescopic frame; 233. Limiting rod; 234. Lifting cylinder;

[0051] 30. Valve body; 40. Flange; 50. Laser welding head; 51. Circular guide rail. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0053] The present invention will be further described below with reference to embodiments.

[0054] Example 1:

[0055] Please see Figures 1 to 10 This invention discloses a valve housing assembly and welding device based on a pre-tightening snap-fit ​​structure, mainly composed of four modules: a frame 10, a valve housing 30, a snap-fit ​​mechanism 20, and a laser welding assembly. The frame 10 serves as the base for the entire machine, and an electric guide rail 11 is mounted on the top surface of the frame 10. The electric guide rail 11 adopts a servo linear module, which has high-precision linear feed capability and can drive the valve housing 30 to complete the station translation, realizing the station flow of loading, docking, welding, and unloading.

[0056] The clamping mechanism 20 is the core positioning fixture of this device, integrating multiple functions such as centering, pre-tightening, and clamping. Its main body is a concentric shaft 21, which is hollow and houses an electric push rod 211. The electric push rod 211 serves as the unified power source for the entire mechanism, simplifying the power layout and ensuring synchronized movements. The clamping mechanism 20 is divided into two main actuation units: a pre-tightening component 22 and a clamping component 23, which respectively complete the positioning and coaxial calibration of the flange 40.

[0057] The pre-tightening component 22 uses the ring frame 221 as the mounting base. The ring frame 221 and the concentric shaft 21 keep their axes coincident, ensuring a unified overall centering reference. The ring frame 221 is circumferentially equidistantly assembled with multiple sets of positioning parts 222 and clamping blocks 223: the rod-shaped positioning parts 222 are mainly used to insert into the standard mounting holes of the flange 40 to support and roughly position the flange 40, initially defining the radial and circumferential positions of the flange 40; the clamping blocks 223 are driven by the electric push rod 211 to make radial extension movements, and finally abut against the inner surface of the flange 40, relying on multi-point radial clamping to complete the precise positioning and pre-tightening of the flange 40, eliminating assembly gaps.

[0058] The snap-fit ​​component 23 is equipped with multiple sets of clamping blocks 231. The operation process follows the logic of pre-tightening followed by snap-fitting: after the pre-tightening component 22 completes the positioning of the flange 40, the electric push rod 211 continues to drive the clamping blocks 231 to extend radially and clamp the inner wall of the valve body 30 from the inside. By using a multi-point internal support method, the axes of the concentric shaft 21, the flange 40, and the valve body 30 are forced to completely coincide, achieving the high-precision coaxiality requirement and solving the industry problem of misalignment and large misalignment between the split valve body and the flange 40.

[0059] The laser welding assembly consists of an annular guide rail 51 and a laser welding head 50. The annular guide rail 51 is fixed on the outside of the annular frame 221 and can drive the laser welding head 50 to move at a uniform speed along the annular weld seam between the flange 40 and the valve body. The laser fusion welding process is used to complete the continuous welding of the annular weld seam. The welding heat input is small, the weld seam is beautiful and the welding strength is high, which is suitable for the welding process requirements of large-diameter valve shells.

[0060] See attached document Figure 1 and Figure 2 The sliding end of the electric guide rail 11 is rigidly fixed to the mounting base 12, which serves as a dedicated support platform for the valve body 30. The top surface of the mounting base 12 has multiple positioning grooves D corresponding to the number and position of the bottom legs of the valve body 30. The shape of the groove matches the outer contour of the leg. After the leg falls into the groove, the initial circumferential and radial limiting of the valve body can be completed to prevent the valve body from slipping.

[0061] The mounting base 12 is fitted with an electric locking plate 13 on its top. The electric locking plate 13 consists of a drive cylinder, a sliding sleeve, and a locking block. Its telescopic end can extend horizontally, allowing the locking part to move directly above the valve body support leg and press down, firmly locking the support leg inside the positioning groove D, thus achieving rigid fixation of the valve body 30 and preventing valve body vibration and displacement during welding. The bottom surface of the locking part of the electric locking plate 13 is machined as a guide slope, which allows for slight guidance and correction of the support leg during pressing down, and also increases the vertical clamping force, improving locking reliability.

[0062] A reasonable adjustment gap is reserved between the outer wall of the valve body support leg and the wall of the positioning groove D. When the electric guide rail 11 drives the valve body 30 to move and connect with the flange 40, if there is a slight coaxial deviation between the two, the pre-tightening structure of the flange 40 will generate a corrective force. With the help of the gap, the valve body can achieve four-way micro-adaptive fine adjustment and automatically complete the axis alignment. After calibration, the electric locking plate 13 is activated to complete the final locking, taking into account both assembly flexibility and fixed reliability.

[0063] See attached document Figure 6 and Figure 7 The ring frame 221 is rigidly sleeved on the outer circle of the concentric shaft 21 by a special fixed bracket to ensure the coaxiality of the two. Multiple rod-shaped positioning parts 222 are evenly distributed around the circumference of the ring frame 221. They adopt an insertion positioning method. During operation, the positioning parts 222 are directly inserted into the standard mounting holes of the flange 40. The hole-shaft cooperation is used to complete the suspension support and coarse positioning of the flange 40. The structure is simple and the positioning efficiency is high.

[0064] Multiple radial grooves are equidistantly spaced along the circumference of the ring body of the ring frame 221. The clamping block 223 is slidably assembled inside the grooves and can freely expand and contract radially. The working end of the clamping block 223 is designed with a stepped structure. This structure can accurately fit the inner corner position of the flange 40, increase the contact area, and distribute the force evenly when multiple points are simultaneously clamped. This can achieve radial precision positioning of the flange 40 and avoid local deformation of the flange 40 caused by stress concentration at a single point.

[0065] See attached document Figure 7 and Figure 8 Each positioning part 222 has an axially oriented calibration hole J inside its rod body, and the outer end face of each clamping block 223 is vertically fixed to the calibration shaft 224. When the electric push rod 211 drives the clamping block 223 to extend radially and press against the inner surface of the flange 40 to complete the pre-tightening action, the calibration shaft 224 will be simultaneously and accurately inserted into the corresponding calibration hole J.

[0066] This set of holes and shafts together constitutes a mechanical synchronous calibration mechanism. On the one hand, it can verify whether the extension stroke of each clamping block 223 is consistent, ensuring uniform circumferential multi-point clamping force. On the other hand, it further constrains the relative position between the ring frame 221, the positioning part 222, and the clamping block 223, improving the coaxiality and circumferential accuracy of the overall positioning of the flange 40, and avoiding the flange 40 skew problem caused by the asynchronous extension of a single set of clamping blocks.

[0067] See attached document Figure 7 and Figure 8The second abutment block 231 is a composite telescopic structure, consisting of a telescopic sleeve frame S1 and a telescopic block S2 nested together. A rubber abutment layer is laminated to the outer end face of the telescopic block S2. The rubber material provides flexible cushioning and increases friction, preventing hard metal from scratching the inner wall of the valve body 30 port and improving anti-slip performance after abutment. The telescopic block S2 is slidably assembled inside the telescopic sleeve frame S1, with an elastic layer filling the space between the two cavities. This allows for elastic adaptive abutment, compensating for port roundness errors and ensuring uniform multi-point contact.

[0068] Each set of telescopic sleeves S1 is fixed to the end of the concentric shaft 21 by the telescopic frame 232, and all the clamping blocks 231 are arranged at equal intervals along the circumference; the telescopic frame 232 can drive the entire set of clamping blocks 231 to make radial telescopic movements, and tighten them from the inside of the valve body 30 port to the outside, and use the internal support method to complete the centering and clamping of the valve body port.

[0069] Meanwhile, each clamping block 223 is equipped with a limiting unit. When clamping block 231 extends and completes the internal support operation, the limiting unit is activated to mechanically lock its position, preventing welding vibration from causing the clamping block to retract and fail to position.

[0070] See attached document Figure 7 A sliding frame 212 is axially slidably mounted on the rod of the concentric shaft 21. The sliding frame 212 and each set of abutting blocks 223 establish a transmission relationship through a wedge-shaped transmission structure 213. The end face of the sliding frame 212 is connected to the telescopic end of the built-in electric push rod 211 through a spring assembly. The spring assembly plays the roles of buffering, force transmission and reset.

[0071] When the electric push rod 211 extends axially, it first pushes the sliding frame 212 to translate axially along the concentric shaft 21 through the spring assembly. The axial displacement of the sliding frame 212 is converted into radial displacement through the wedge transmission structure 213, which drives all the abutting blocks 223 to extend outward synchronously along the slide groove, and finally press against the inner surface of the flange 40, thus completing the pre-tightening and precision positioning of the flange 40.

[0072] The wedge transmission structure 213 consists of two sets of wedge frames that fit together, which are fixed on the sliding frame 212 and the abutting block 223 respectively. It achieves motion mode conversion by relying on inclined plane transmission, and has the characteristics of smooth transmission, stroke amplification and good synchronization. It is suitable for circumferential multi-point synchronous drive conditions.

[0073] See attached document Figure 7 A hinged bracket 214 is axially arranged inside the concentric shaft 21. The hinged bracket 214 consists of a central hinge seat and multiple inclined hinge rods. The central hinge seat is fixed to the telescopic end of the electric push rod 211. The end of each inclined hinge rod is hinged to the movable end of the corresponding telescopic frame 232, forming a linkage transmission mechanism.

[0074] When the electric actuator 211 extends or retracts axially, it simultaneously drives the hinge seat to move axially. The tilting hinge rod then swings, converting the axial power into radial thrust, which drives the telescopic frame 232 to complete the telescopic action. This, in turn, drives the second abutment block 231 to extend radially, achieving the internal support and abutment of the valve body 30 port. This device adopts a design where a single electric actuator 211 drives two sets of mechanisms in a time-sharing manner, sequentially completing the two actions of flange 40 pre-tightening and valve body internal support. The power components have a high degree of integration, and the action sequence is controllable, reducing equipment manufacturing costs and control difficulty.

[0075] Example 2: The difference from Example 1 is that;

[0076] See attached document Figure 7 and Figure 8 This embodiment refines the design of the limiting unit structure. The limiting unit consists of a limiting hole X, a limiting rod 233, and a lifting cylinder 234: the limiting hole X is axially opened inside the telescopic block S2; the limiting rod 233 is vertically mounted on the bottom of the first abutment block 223 through a sliding sleeve, and can slide axially along the sleeve; the lifting cylinder 234 is fixed on the outside of the first abutment block 223, and the telescopic end of the cylinder is connected to the limiting rod 233, serving as the power source for the limiting action.

[0077] After the second clamping block 231 extends radially and completes its internal support and clamping of the valve body 30, the lifting cylinder 234 extends, pushing the limiting rod 233 to move horizontally and insert into the limiting hole X inside the telescopic block S2. The hole-shaft cooperation achieves mechanical locking, restricting the retraction displacement of the telescopic block S2. This structure features purely mechanical limiting, strong vibration resistance, and can maintain a clamping state under continuous vibration conditions during laser welding, ensuring consistent coaxial accuracy. After the process is completed, the lifting cylinder 234 retracts, the limiting rod 233 exits the limiting hole X, and the second clamping block 231 resets under the action of the internal elastic layer.

[0078] Example 3: The difference from Example 1 is that;

[0079] See attached document Figure 9 and Figure 10 Each rod-shaped positioning part 222 has a clamping part on its outer side, which can fit and limit the flange 40's movement, further restricting the flange 40's flipping and displacement. The positioning part 222 integrates a self-locking unit, which automatically activates during the initial suspension and support stage of the flange 40 to prevent the flange 40 from slipping or shifting. After the pre-tightening part 22 completes the alignment and pre-tightening of the flange 40's axis, the self-locking unit can automatically retract and reset, without affecting subsequent welding operations.

[0080] The self-locking unit is embedded within the positioning part 222, and its structure includes a hidden groove, three sets of T-shaped clamping brackets 2221, sector blocks 2222, and metal springs 2223. A closed hidden groove is formed inside the positioning part 222. The three sets of T-shaped clamping brackets 2221 are evenly distributed circumferentially at 120°, with their tails extending into the hidden groove and fixed to the sector blocks 2222. The three sector blocks 2222 are joined in pairs to form a complete ring. A metal spring 2223 is installed between each sector block 2222 and the inner wall of the hidden groove. Under normal conditions, the metal spring 2223 provides a restoring elastic force. The contact surface of the T-shaped clamping brackets 2221 has a composite elastic anti-slip layer to increase friction and prevent scratching the inner wall of the flange 40 mounting hole.

[0081] Operating principle: When the positioning part 222 is inserted into the mounting hole of the flange 40 and the flange 40 is supported by the top surface of the rod, the flange 40 exerts downward pressure on the T-shaped clamping frame 2221 above, causing it and the corresponding sector block 2222 to sink into the hidden groove together; the sinking sector block 2222 uses the wedge surfaces on both sides to squeeze the other two sets of sector blocks 2222, causing them to expand outward in the radial direction, driving the remaining two sets of T-shaped clamping frames 2221 to press against the left and right sides of the inner wall of the mounting hole. The three-point clamping achieves automatic self-locking during the flange 40 support stage, preventing the flange 40 from slipping or swaying.

[0082] When the clamping block 223 completes the pre-tightening of the flange 40 and the axis of the flange 40 is completely aligned with the positioning part 222, the weight of the flange 40 no longer acts alone on the T-shaped clamping frame 2221 above. At this time, all the sector blocks 2222 retract under the elastic restoring force of the metal spring 2223, and the three sets of T-shaped clamping frames 2221 retract into the hidden grooves in sync. The self-locking state is automatically released, which does not hinder the subsequent welding and workpiece unloading process, realizing the fully automatic logic of self-weight triggering and calibration reset.

[0083] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A valve housing assembly and welding device based on a pre-tightening snap-fit ​​structure, comprising a frame (10) with an electric guide rail (11), a valve housing (30) mounted on the moving end of the electric guide rail (11), and a snap-fit ​​mechanism (20) with laser-welded components, characterized in that: The locking mechanism (20) includes a concentric shaft (21) with an internal electric push rod (211), a pre-tightening member (22), and a locking member (23). The pre-tightening component (22) includes an annular frame (221) that coincides with the axis of the concentric shaft (21). The annular frame (221) is provided with a plurality of positioning parts (222) and a plurality of abutting blocks (223). The plurality of positioning parts (222) are used to position and support the flange (40). The plurality of abutting blocks (223) are driven to move radially by an electric push rod (211) and abut against the inner surface of the flange (40) to achieve precise positioning of the flange (40). The snap-fit ​​component (23) includes several clamping blocks (231). After the pre-tightening component (22) completes the pre-tightening of the flange (40), the several clamping blocks (231) are driven to move radially by the electric push rod (211) and abut against the inner surface of the valve body (30) port, so that the axes of the concentric shaft (21), the flange (40), and the valve body (30) coincide. The laser welding component includes an annular guide rail (51) and a laser welding head (50) that moves in annular motion along the annular guide rail (51). The laser welding head (50) is used to weld the annular weld between the flange (40) and the valve body (30).

2. The valve housing assembly and welding device based on a pre-tightening snap-fit ​​structure according to claim 1, characterized in that: The moving end of the electric guide rail (11) is fixed with a mounting base (12), and the top of the mounting base (12) is provided with a positioning groove D that matches the number of legs of the valve body (30) base. An electric locking plate (13) is installed on the mounting base (12). The locking part of the electric locking plate (13) can extend to the top of the base support leg and press down to lock the base support leg embedded in the positioning groove D. After the base support leg is embedded in the positioning groove D, an adjustment gap is reserved between the outer wall of the support leg and the groove wall so that the valve body (30) can achieve four-way micro-position fine adjustment.

3. The valve housing assembly and welding device based on a pre-tightening snap-fit ​​structure according to claim 1, characterized in that: The ring frame (221) is fixed to the outer surface of the concentric shaft (21) by a fixed bracket. Several positioning parts (222) are fixed in a ring at equal intervals on the side of the ring frame (221). The positioning parts (222) are rod-shaped structures and are inserted into the mounting holes of the flange (40) to complete the rough positioning of the flange (40). The ring frame (221) has several grooves equidistantly arranged in the radial direction, and several abutting blocks (223) are slidably assembled inside the grooves. The abutting end of the abutting block (223) is set in a stepped shape to abut against the corner position of the inner surface of the flange (40).

4. The valve housing assembly and welding device based on a pre-tightening snap-fit ​​structure according to claim 3, characterized in that: Each of the positioning parts (222) has a calibration hole J inside, and each of the clamping blocks (223) has a calibration shaft (224) fixed on it. When the clamping block (223) moves radially and clamps against the inner surface of the flange (40), the calibration shaft (224) is inserted into the calibration hole J to complete the position calibration.

5. The valve housing assembly and welding device based on a pre-tightening snap-fit ​​structure according to claim 1, characterized in that: The second abutting block (231) is composed of a telescopic frame S1 and a telescopic block S2. The telescopic block S2 is slidably assembled inside the telescopic frame S1. An elastic layer is provided between the telescopic block S2 and the bottom of the telescopic frame S1. A rubber abutting layer is provided on the outer end face of the telescopic block S2. Each of the telescopic sleeves S1 is fixed to the end of the concentric shaft (21) by a telescopic frame (232). Several telescopic frames (232) are arranged in a ring at equal intervals. The telescopic frame (232) drives the abutment block two (231) to move radially and abut against the valve body (30) port from the inside to the outside. Each of the first abutment block (223) is equipped with a limiting unit for locking the position of the second abutment block (231) after radial displacement.

6. The valve housing assembly and welding device based on a pre-tightening snap-fit ​​structure according to claim 5, characterized in that: The limiting unit includes a limiting hole X, a limiting rod (233) and a lifting cylinder (234), wherein the limiting hole X is opened inside the telescopic block S2; The limiting rod (233) is slidably installed at the bottom of the first abutment block (223) via a sleeve. The lifting cylinder (234) is fixed on the first abutment block (223) and its driving end is connected to the limiting rod (233). The lifting cylinder (234) drives the limiting rod (233) to move and insert into the limiting hole X, thereby achieving the locking and positioning of the second abutment block (231).

7. The valve housing assembly and welding device based on a pre-tightening snap-fit ​​structure according to claim 1, characterized in that: A sliding frame (212) is axially slidably mounted on the concentric shaft (21), and a wedge-shaped transmission structure (213) is assembled between the sliding frame (212) and several abutting blocks (223). The sliding frame (212) is connected to the electric push rod (211) via a spring assembly. The electric push rod (211) pushes the sliding frame (212) axially, and the axial motion is converted into radial motion through the wedge-shaped transmission structure (213), driving the first abutment block (223) to extend radially to complete the pre-tightening operation of the flange (40).

8. A valve housing assembly and welding device based on a pre-tightening snap-fit ​​structure according to claim 5, characterized in that: The concentric shaft (21) is axially provided with a hinge bracket (214). The hinge bracket (214) includes a hinge seat and an inclined hinge rod. The hinge seat is fixed to the telescopic end of the electric push rod (211). The two ends of the hinge rod are respectively hinged to the telescopic part of the hinge seat and the telescopic frame (232). When the electric push rod (211) moves axially, it drives the telescopic frame (232) to extend and retract through the hinge rod, driving the second abutment block (231) to move radially and abut against the inner surface of the valve body (30) port.

9. A valve housing assembly and welding device based on a pre-tightening snap-fit ​​structure according to claim 4, characterized in that: Each of the positioning parts (222) is provided with a clamping part that fits against the outer side of the flange (40) on the outside. The positioning part (222) is provided with a self-locking unit inside. The self-locking unit realizes anti-displacement self-locking during the flange (40) support stage and automatically retracts and resets after the pre-tightening member (22) completes the pre-tightening calibration of the flange (40).

10. A valve housing assembly and welding device based on a pre-tightening snap-fit ​​structure according to claim 9, characterized in that: The self-locking unit includes a hidden groove inside the positioning part (222) and three sets of T-shaped clamping frames (2221) arranged in a 120° ring. The T-shaped clamping bracket (2221) is radially slidably mounted on the positioning part (222). The contact surface of the T-shaped clamping bracket (2221) is provided with an elastic anti-slip layer. The tail of the T-shaped clamping bracket (2221) extends into the hidden groove and fixes the fan-shaped block (2222). The fan-shaped block (2222) is fixed with the inner wall of the hidden groove with a metal spring sheet (2223). When the flange (40) is supported by the positioning part (222), the upper T-shaped clamping frame (2221) sinks under the weight of the flange (40), and pushes the other two sets of T-shaped clamping frames (2221) to extend radially through the wedge surface of the sector block (2222), and clamps against the inner wall of the mounting hole of the flange (40) to achieve self-locking; after the flange (40) completes the axis alignment, the metal spring (2223) drives the sector block (2222) and the T-shaped clamping frame (2221) to reset, and release the self-locking state.

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