A positioning and clamping tool for welding a frame of a working machine

Abstract

The utility model discloses a positioning and clamping tool for engineering machinery frame welding, which comprises: a base assembly; a positioning mechanism mounted on the base assembly, the positioning mechanism comprising a plurality of positioning components corresponding to the key structures of the engineering machinery frame to be welded, a longitudinal positioning component, a front end positioning component and a rear end positioning component, which are used to cooperatively define the spatial attitude of each component of the frame; a clamping mechanism mounted on the base assembly, the clamping mechanism comprising a plurality of clamping units cooperatively matched with the positioning mechanism, which are used to lock the components of the frame in multiple directions at the preset positioning position. The utility model sets a plurality of positioning components corresponding to the key structures of the frame to be welded and a plurality of clamping units locked in multiple directions, thereby constructing a systematic positioning and clamping system, achieving the cooperative definition and firm fixation of the spatial attitude of each component of the frame, and significantly improving the geometric precision of the welded frame and the stability of product quality.

Description

Technical Field

[0001] This utility model relates to the field of engineering machinery manufacturing technology, and in particular to a positioning and clamping fixture for welding engineering machinery frames. Background Technology

[0002] As the core load-bearing structural component of construction machinery such as excavators, the manufacturing quality of the frame directly determines the performance, reliability, and service life of the entire machine. A typical construction machinery frame is usually welded together from multiple irregularly shaped plates and functional components, including left and right longitudinal beams, multiple transverse connecting parts, a front-end working device mounting base, a rear power counterweight mounting area, and a central slewing bearing mounting platform, forming a high-strength open-type box-shaped frame structure. This frame structure is characterized by a large number of parts, irregular shapes, complex functional interfaces, and high precision requirements. Key dimensions such as the levelness and coaxiality of the slewing bearing mounting platform, the positional accuracy of the front-end mounting plate, the parallelism and perpendicularity of the left and right longitudinal beams, and the spatial orientation of the rear box structure directly affect the assembly accuracy of subsequent working devices, the overall slewing performance, and the stress distribution of the structure. Therefore, accurately controlling the spatial relationship of each component during the welding and assembly process to ensure the geometric accuracy and consistency of the welded frame is a core technological challenge in construction machinery manufacturing.

[0003] In existing engineering machinery frame welding production processes, due to the complex frame structure, numerous and irregularly shaped parts, traditional welding fixtures often employ relatively simple support and positioning methods, relying mainly on workers' experience for component placement, alignment, and temporary tack fixing. This traditional production method presents the following technical problems: First, the spatial positioning accuracy of each component, such as the levelness of the slewing bearing mounting platform, the verticality of the longitudinal beam plate, the coordinate position of the front mounting plate, and the spatial orientation of the rear box structure, largely depends on the operator's skill level and visual judgment. Even skilled workers find it difficult to ensure that each frame meets the same high precision requirements when dealing with so many positioning references and complex spatial relationships, resulting in poor product consistency and low pass rate. Second, due to the lack of systematic multi-point positioning and reliable clamping mechanisms, components are prone to displacement during welding due to welding heat deformation, self-weight, or external forces, causing dimensional deviations, torsional deformation, and other quality problems in the welded frame. In severe cases, rework or scrapping may be necessary, increasing production costs. In addition, traditional methods require workers to repeatedly perform operations such as measurement, adjustment, and fixation, which are cumbersome and time-consuming. Furthermore, the positioning of multiple key feature points cannot be completed simultaneously in a single tooling, which increases the turnover time and error accumulation between processes, severely restricting the improvement of production efficiency and the stability of product quality.

[0004] Therefore, how to design a welding fixture that can achieve precise positioning of multiple feature points, reliable clamping in multiple directions, and simple and efficient operation, so as to improve the welding accuracy, product consistency and production efficiency of engineering machinery frames and reduce the dependence on worker skills, is a technical problem that urgently needs to be solved in the current engineering machinery manufacturing field. Utility Model Content

[0005] The technical problem to be solved by this utility model is to address the issues of low positioning accuracy, poor product consistency, easy thermal deformation and displacement during welding, cumbersome procedures, and low production efficiency caused by traditional tooling relying on worker experience in the welding process of existing engineering machinery frames. The present invention provides a positioning and clamping tooling for welding engineering machinery frames that can achieve precise positioning of multiple feature points, reliable clamping in multiple directions, and simple and efficient operation.

[0006] The technical solution adopted by this utility model to solve its technical problem is: A positioning and clamping fixture for welding the frame of engineering machinery includes: a base assembly; The positioning mechanism is installed on the base assembly. The positioning mechanism includes a reference positioning component, a longitudinal positioning component, a front positioning component, and a rear positioning component, which are set one-to-one with the key structures of the frame of the engineering machinery to be welded. They are used to coordinate and limit the spatial posture of each component of the frame. The clamping mechanism, which is mounted on the base assembly, includes multiple clamping units that cooperate with the positioning mechanism to lock the components of the frame in preset positioning positions in multiple directions.

[0007] Preferably, the base assembly includes: a main bearing plate; multiple reinforcing ribs welded to the bottom of the main bearing plate to enhance the deformation resistance; and multiple sets of reference holes and threaded holes pre-installed on the main bearing plate and matching the key feature points of the engineering machinery frame to be welded.

[0008] Preferably, the cross-section of the reinforcing rib is C-shaped, and a base plate is welded to its bottom surface. The base plate has bolt holes for connecting to the ground.

[0009] Preferably, the reference positioning assembly includes: a circular positioning platform simulating the mounting surface of a slewing bearing; multiple rectangular positioning elements disposed around the circular positioning platform for planar positioning; and a Y-shaped positioning element detachably mounted on the base assembly for horizontal and vertical positioning of the frame.

[0010] Preferably, the circular positioning platform has a stepped structure, including a hollow cylinder and a rectangular mounting block disposed below it; The Y-shaped positioning component includes two forked arms and a bottom surface. The two forked arms are used to pass through the rectangular through holes of the frame and abut against its transverse connecting parts, while the bottom surface is used to abut against the inner side of the bottom surface of the frame.

[0011] Preferably, the longitudinal positioning component includes: a support tower distributed along the length of the frame; and multiple ball bearing seats located on both sides of the support tower for supporting the longitudinal beam plate of the engineering machinery frame to be welded and providing a foundation for horizontal movement.

[0012] Preferably, the front positioning component includes: multiple positioning pins of a rectangular bracket for positioning the mounting plate from the top and sides; a positioning block located at the front end of the rectangular main board for mounting the mounting plate; and several pads located on the base assembly for assisting in fixing the rectangular main board.

[0013] Preferably, the rear positioning component includes: two sets of positioning rod fixtures arranged at different heights along the overall length direction of the base, each set of positioning rod fixtures including multiple bases and positioning rods detachably mounted on the bases, the positioning rods being used to pass through the longitudinal beam plates of the frame; and a manual push plate assembly mounted on the bases for pushing the longitudinal beam plates to achieve lateral positioning, the manual push plate assembly including a control lever and a push plate.

[0014] Preferably, the clamping mechanism includes: a transverse clamping group for transversely fixing the longitudinal beam plate; a vertical clamping group for vertically fixing the longitudinal beam plate from the top; a front clamping group for fixing the front area of ​​the frame; and a rear clamping group for fixing the rear power and counterweight mounting area of ​​the frame.

[0015] Preferably, the lateral clamping group includes a first manual clamping plate group and a second manual clamping plate group, both of which include a control lever and a clamping plate; the vertical clamping group includes multiple clamping rods, each of which includes a hollow rod with threads at both ends and two clamping heads with clamping grooves; the front clamping group includes manual clamping plates that are arranged horizontally and vertically; and the rear clamping group includes an inclined clamping group, which includes multiple F-type clamps.

[0016] The beneficial effects that this utility model can achieve are: 1. By setting up multiple sets of positioning components that correspond one-to-one with the key structures of the frame to be welded, as well as multiple clamping units that lock in multiple directions, a systematic positioning and clamping system was constructed. This system achieved coordinated limitation and firm fixation of the spatial posture of each component of the frame, effectively solving the technical problems of low positioning accuracy and poor product consistency caused by manual visual judgment, and significantly improving the geometric accuracy of the welding frame and the stability of product quality.

[0017] 2. Through the coordinated operation of multiple positioning components and multiple clamping units, all parts are precisely constrained in preset positions and multi-directional clamping forces are applied before welding, forming a high-rigidity integral structure. This effectively suppresses welding thermal deformation and external interference, effectively solving the technical problem of component displacement caused by thermal deformation, self-weight or external force during welding, resulting in dimensional deviation and torsional deformation, and ensuring the dimensional accuracy and geometric tolerance of the frame after welding.

[0018] 3. The core benchmark is established by the circular positioning platform, rectangular positioning parts and Y-shaped positioning parts of the benchmark positioning component. The support tower and ball bearing seat of the longitudinal positioning component limit the parallelism and perpendicularity of the longitudinal beam plate. The positioning pin and positioning block of the front positioning component accurately position the coordinate position of the front mounting plate. The positioning rod tooling and manual push plate assembly of the rear positioning component control the spatial posture of the rear box structure. With the clamping mechanism, the clamping units in multiple directions (lateral, vertical, front and rear) form rigid constraints, realizing the synchronous positioning and reliable fixation of the key feature points of the frame. This effectively solves the problems of cumbersome processes, low production efficiency and accumulation of errors between processes, and improves production efficiency and product quality stability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the working state of a positioning and clamping fixture for welding the frame of engineering machinery in Example 1; Figure 2 This is a schematic diagram of the structure of the engineering machinery frame in Example 1; Figure 3 This is a schematic diagram of a positioning and clamping fixture for welding engineering machinery frames in Example 1; Figure 4 for Figure 3 Enlarged view of point A in the middle; Figure 5 for Figure 3 Enlarged view of point B in the middle.

[0020] Reference numerals: 1. Base assembly; 11. Reinforcing rib; 12. Pad; 2. Positioning mechanism; 3. Clamping mechanism; 4. Reference positioning assembly; 41. Circular positioning platform; 42. Y-shaped positioning component; 43. Rectangular positioning component; 5. Longitudinal positioning assembly; 51. Support tower; 52. Ball bearing seat; 6. Front positioning assembly; 61. Positioning pin; 62. Positioning block; 7. Rear positioning assembly; 71. Positioning rod fixture; 72. Base; 73. Manual push plate assembly; 8. Lateral clamping assembly; 81. First manual clamping plate assembly; 82. Second manual clamping plate assembly; 9. Vertical clamping assembly; 91. Clamping rod Components; 92. Hollow rod; 93. Clamping head; 94. Clamping groove; 10. Front clamping assembly; 101. Manual clamping plate; 11. Rear clamping assembly; 111. F-type clamp; 112. Clamp mounting base; 120. Main frame; 121. Left longitudinal beam plate; 122. Right longitudinal beam plate; 123. Transverse connecting component; 13. Front working device mounting base; 131. Mounting ear plate; 14. Rear power and counterweight mounting area; 141. Semi-enclosed box; 142. Mounting interface; 15. Middle slewing bearing mounting platform; 151. Rectangular through hole; 152. Circular through hole; 16. Mounting support plate. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, but these specific embodiments do not limit the scope of protection of the present invention in any way. Example

[0022] See Figure 1-5 A positioning and clamping fixture for welding engineering machinery frames includes a base assembly 1, a positioning mechanism 2, and a clamping mechanism 3. This fixture is mainly used for precise positioning and reliable clamping during the welding process of engineering machinery frames. It can quickly and accurately control the spatial positional relationship of various components of the frame, ensuring the geometric accuracy and structural stability of the frame after welding.

[0023] See key points Figure 2 In this embodiment, the structure of the engineering machinery frame to be welded includes a main frame 120, a front-end working device mounting base 13, a rear-end power and counterweight mounting area 14, a central slewing bearing mounting platform 15, and auxiliary functional structures. The main frame 120 is composed of a left longitudinal beam plate 121, a right longitudinal beam plate 122, and a transverse connecting member 123, forming an open box-type frame structure. The left longitudinal beam plate 121 and the right longitudinal beam plate 122 are arranged parallel to each other along the length of the frame, and the left longitudinal beam plate 121 and the right longitudinal beam plate 122 are irregularly shaped plate structures. The transverse connecting member 123 is fixedly connected between the left longitudinal beam plate 121 and the right longitudinal beam plate 122, and the transverse connecting member 123 includes multiple reinforcing plates, which are welded together to form a whole.

[0024] The front working device mounting base 13 is located at one end of the frame. The main body of the front working device mounting base 13 is the mounting ear plate 131 extending outward or upward from the left longitudinal beam plate 121 and the right longitudinal beam plate 122 respectively. The mounting ear plate 131 is a pair of thick ear plate structures, and each mounting ear plate 131 is provided with a circular pin hole.

[0025] The rear power and counterweight installation area 14 is located at the other end of the frame. It is a C-shaped plate structure and forms a semi-enclosed box 141 by connecting the left longitudinal beam plate 121 and the right longitudinal beam plate 122. The semi-enclosed box 141 contains multiple planes and installation interfaces 142.

[0026] The central slewing bearing mounting platform 15 is located in the bottom center area of ​​the frame and is a horizontal steel plate structure. A rectangular through hole 151 is formed in the center of the central slewing bearing mounting platform 15. Multiple connecting pin holes are provided on the circumference of the rectangular through hole 151. A circular through hole 152 is also provided on one side of the rectangular through hole 151, and a rectangular stepped countersunk hole is provided at the other end of the rectangular through hole 151. Multiple circular bolt holes are evenly distributed around the central area.

[0027] The auxiliary functional structures are distributed on the side walls of the left longitudinal beam plate 121 and the right longitudinal beam plate 122. These auxiliary functional structures include mounting plates 16, bosses, and mounting holes, which are pre-set on the surface of the longitudinal beam plates. The mounting plates 16 are located at the bottom of the left longitudinal beam plate 121 and the right longitudinal beam plate 122 on the side with mounting lugs 131, and include a rectangular main plate and two rectangular supports extending from the main plate to both sides. The longitudinal beam plates also have process holes or inspection holes, exhibiting a large, irregularly shaped hole structure.

[0028] See Figure 3-5 To hold the aforementioned engineering machinery frame to be welded, in this embodiment, the base assembly 1 has a rectangular structure, capable of stably supporting the weight of the frame to be welded and each set of positioning and clamping components. The base assembly 1 mainly consists of a heavy steel plate as the main support plate, with several reinforcing ribs 11 welded below the main support plate. The reinforcing ribs 11 adopt a C-shaped cross-section structure and are welded to the main support plate to form a stable connection, significantly improving the base's resistance to torsion and deformation. A pad 12 is welded to the bottom surface of the reinforcing ribs 11, and the pad 12 is connected to the ground by bolts to enhance the stability of the entire positioning and clamping fixture. Multiple sets of precision reference holes and threaded holes are pre-set on the main support plate, and the positions of the reference holes and threaded holes match the positions of the key feature points of the frame to be welded, to achieve precise assembly of the positioning mechanism 2 and the clamping mechanism 3.

[0029] The positioning mechanism 2 corresponds one-to-one with the key structures of the engineering machinery frame to be welded. In this embodiment, the positioning mechanism 2 includes four sets of positioning components, each of which is fixedly installed through the reference holes on the base assembly 1. The reference positioning component 4, the longitudinal positioning component 5, the front positioning component 6, and the rear positioning component 7 work together to define the spatial orientation of the frame. This grouping design allows the positioning fixture to adapt to the complex structural characteristics of the engineering machinery frame.

[0030] exist Figure 4In this assembly, the reference positioning component 4 is installed at the center of one side of the top surface of the base assembly 1, corresponding to the structure of the central slewing bearing mounting platform 15 of the frame to be welded. The main body of the reference positioning component 4 includes a circular positioning platform 41 simulating the slewing bearing mounting base, a Y-shaped positioning element 42, and rectangular positioning elements 43 set at the four corners of the positioning platform. The circular positioning platform 41 has a stepped structure, including a hollow cylinder and a rectangular mounting block set below the hollow cylinder. The rectangular mounting block is installed on the top surface of the base assembly 1 by bolts. The hollow cylinder is set with a circular through hole 152 corresponding to the central slewing bearing mounting platform 15. There are four rectangular positioning elements 43, which are respectively installed at the four corners of the positioning area of ​​the central slewing bearing mounting platform 15 for planar positioning of the central slewing bearing mounting platform 15. The Y-shaped positioning component 42 is detachably installed on the top surface of the base assembly 1. When the frame to be welded is placed on the base assembly 1, the Y-shaped positioning component 42 passes through the rectangular through hole 151, and its two forked arms abut against the reinforcing plate. The bottom surface of the Y-shaped positioning component 42 abuts against the inner side of the bottom surface of the engineering machinery frame, and is used to position the engineering machinery frame in the horizontal and vertical directions.

[0031] See Figure 5 The longitudinal positioning component 5 is installed on the base assembly 1 along the length of the frame to be welded, and is used to define the spatial position and orientation of the left and right longitudinal beam plates 121 and 122 of the frame. The longitudinal positioning component 5 is a rectangular support tower 51 structure. Multiple ball bearing seats 52 are provided on both sides of the support tower 51 from top to bottom. In the process of supporting the sides of the left and right longitudinal beam plates 121 and 122, the ball bearing seats 52 can also provide a sliding base for the horizontal movement of the left and right longitudinal beam plates 121 and 122.

[0032] exist Figure 5 In this assembly, the front-end positioning component 6 is installed on the base assembly 1 in the area corresponding to the mounting plate 16 of the frame to be welded. Its main body includes multiple positioning pins 61 and positioning blocks 62. The positioning pins 61 are used to position the two rectangular supports of the mounting plate 16. Each rectangular support is fixed by three positioning pins 61, one of which fixes the top surface of the rectangular support, and the other two fix the sides. The positioning blocks 62 are located at the front end of the rectangular main plate and, together with several pads on the base assembly 1, fix the rectangular main plate to the base assembly 1, precisely defining the spatial position of the front-end mounting plate 16.

[0033] exist Figure 4In the middle, the rear positioning component 7 is installed on the base assembly 1 in the area corresponding to the rear power and counterweight installation area 14 of the frame to be welded. Its main body includes two sets of positioning rod fixtures 71 at different heights, which are arranged sequentially along the length of the base assembly 1. The lower set of positioning rod fixtures 71 includes four bases 72 arranged in pairs on both sides of the base assembly 1. The top of the base 72 is provided with a detachable positioning rod, and two positioning rods pass through the entire left longitudinal beam plate 121 and right longitudinal beam plate 122 respectively. The higher set of positioning rod fixtures 71 includes four bases 72 arranged in pairs on both sides of the base assembly 1. The top of the base 72 is provided with a detachable positioning rod, and two positioning rods pass through the entire left longitudinal beam plate 121 and right longitudinal beam plate 122 respectively. The rear positioning component 7 also includes a manual push plate component 73 mounted on the base 72. The manual push plate component 73 has a control lever on one side of the base 72 and a push plate on the other side. By rotating the control lever, the push plate can move forward or backward in the direction of the longitudinal beam plate, which is used to achieve lateral positioning of the left longitudinal beam plate 121 and the right longitudinal beam plate 122.

[0034] See Figure 3-5 The clamping mechanism 3 works in conjunction with the positioning mechanism 2 to securely lock all components of the frame to be welded in the preset positioning positions, preventing displacement due to thermal deformation, vibration, or external forces during the welding process. The clamping mechanism 3 includes four sets of clamping units with different functions. Each set of clamping units is fixedly installed through the threaded holes or reference holes of the base assembly 1, and its clamping direction matches the positioning reference of the positioning mechanism 2.

[0035] See Figure 4-5 The transverse clamping assembly 8 includes a first manual clamping plate assembly 81 disposed on opposite sides of the longitudinal positioning assembly 5 and a second manual clamping plate assembly 82 disposed in front of the rear positioning assembly 7. The first manual clamping plate assembly 81 includes a lever and a clamping plate for clamping the left longitudinal beam plate 121 and the right longitudinal beam plate 122 between the clamping plate and the ball bearing seat 52. The second manual clamping plate assembly 82 includes a lever and a clamping plate for pressing and clamping the left longitudinal beam plate 121 and the right longitudinal beam plate 122 inward.

[0036] The vertical clamping assembly 9 includes three clamping rods 91 for fixing and clamping the left longitudinal beam plate 121 and the right longitudinal beam plate 122 from their top ends. Each clamping rod 91 includes a hollow rod 92 with a double-ended threaded structure and two clamping heads 93 threaded to both ends of the hollow rod 92. The clamping heads 93 are provided with clamping grooves 94, which fix the distance between the left longitudinal beam plate 121 and the right longitudinal beam plate 122 through the two clamping grooves 94, thereby achieving vertical clamping of the longitudinal beam plates.

[0037] exist Figure 5In the middle, the front clamping group 10 is set at the corresponding position of the front end of the left longitudinal beam plate 121 and the right longitudinal beam plate 122, including two horizontally arranged manual clamping plates 101 and two longitudinally parallel arranged manual clamping plates 101, which are used to clamp the side and end faces of the left longitudinal beam plate 121 and the right longitudinal beam plate 122 respectively, so as to realize multi-directional fixation of the front end area.

[0038] exist Figure 4 In the middle, the rear clamping group 11 is located inside the rear positioning component 7, including two inclined clamping groups. Each clamping group has two F-type clamps 111 arranged in parallel front and rear. The F-type clamp seat is mounted on the clamp mounting base 112. The clamp mounting base 112 is inclinedly set on the platform of the base assembly 1. The F-type clamps 111 pass through the mounting interface 142 of the C-shaped plate structure to clamp the C-shaped plate structure, so as to achieve stable clamping of the rear box structure.

[0039] Each positioning component is interconnected via the base assembly 1, forming a complete positioning system. The reference positioning component 4 is located at the center of one side of the base assembly 1. The longitudinal positioning components 5 are distributed along the length of the frame. The front positioning component 6 and the rear positioning component 7 are located at the front and rear ends of the base assembly 1, respectively, maintaining appropriate spacing to avoid interference during the positioning process. Each clamping unit cooperates with each other via the base assembly 1. The transverse clamping group 8 corresponds to the longitudinal positioning component 5, the vertical clamping group 9 is distributed at key positions on the top of the frame, the front clamping group 10 is integrated into the front positioning area, and the rear clamping group 11 is integrated into the rear positioning area to ensure coordinated clamping. The entire device has a compact and reasonable structure, with clear and defined connections between components, ensuring smooth welding operations.

[0040] The working principle and method of the above-mentioned positioning and clamping fixture for welding engineering machinery frames are as follows: The first step is for the operator to place the central slewing bearing mounting platform 15 on the reference positioning component 4 of the base assembly 1, so that the circular through hole 152 of the central slewing bearing mounting platform 15 matches the hollow cylinder of the circular positioning platform 41, and at the same time, the positioning areas at the four corners of the central slewing bearing mounting platform 15 match the four rectangular positioning parts 43 precisely.

[0041] In the second step, after the initial positioning of the central slewing bearing mounting platform 15 is completed, the operator installs the Y-shaped positioning component 42 above the rectangular through hole 151 of the central slewing bearing mounting platform 15, so that the two forked arms of the Y-shaped positioning component 42 extend upwards, preparing for the subsequent positioning of the reinforcing plate. Then, the left longitudinal beam plate 121 and the right longitudinal beam plate 122 of the frame to be welded are placed on both sides of the support tower 51 of the longitudinal positioning assembly 5, so that the inner sides of the left longitudinal beam plate 121 and the right longitudinal beam plate 122 are respectively attached to the ball bearing seats 52 on both sides of the support tower 51, ensuring that the length direction of the longitudinal beam plate is consistent with the length direction of the base assembly 1.

[0042] Thirdly, the operator places the reinforcing plate in the transverse connecting piece 123 at a preset position between the left longitudinal beam plate 121 and the right longitudinal beam plate 122, so that the end of the reinforcing plate is in contact with the inner surface of the longitudinal beam plate. At this time, the two forked arms of the Y-shaped positioning piece 42 abut against the reinforcing plate, and the bottom surface of the Y-shaped positioning piece 42 abuts against the inner side of the bottom surface of the construction machinery frame, realizing the precise positioning of the construction machinery frame in the horizontal and vertical directions, which is used to ensure that the relative positional relationship between the reinforcing plate and the central slewing bearing mounting platform 15 is accurate.

[0043] Fourth, the operator places the mounting plate 16 of the front-end working device mounting base 13 into the positioning area of ​​the front-end positioning component 6. First, the front end of the rectangular main plate of the mounting plate 16 mates with the positioning block 62. Then, the two rectangular brackets of the mounting plate 16 are placed in the corresponding positioning pins 61. Each rectangular bracket is precisely positioned by three positioning pins 61. One positioning pin 61 fixes the top surface of the rectangular bracket, and the other two positioning pins 61 fix the sides of the rectangular bracket, which completely defines the spatial posture of the mounting plate 16.

[0044] Fifth, the operator places the semi-enclosed housing 141 of the rear power and counterweight installation area 14 into the positioning area of ​​the rear positioning assembly 7. First, the left longitudinal beam plate 121 and the right longitudinal beam plate 122 are passed through the two positioning rods of the lower set of positioning rod fixtures 71, ensuring the positioning rods pass through the entire left and right longitudinal beam plates 121 and 122, achieving vertical positioning of the longitudinal beam plates at this position. Then, the left and right longitudinal beam plates 121 and 122 are passed through the two positioning rods of the higher set of positioning rod fixtures 71, again ensuring the positioning rods pass through the entire left and right longitudinal beam plates 121 and 122, achieving vertical positioning of the longitudinal beam plates at this position. The cooperation of the two sets of positioning rod fixtures 71 at different heights ensures the spatial stability of the longitudinal beam plates in the rear area. Subsequently, the operator rotates the control lever of the manual push plate assembly 73, causing the push plate to move towards the longitudinal beam plates, pushing the left and right longitudinal beam plates 121 and 122 against the positioning reference surface, thus completing the lateral positioning of the rear area.

[0045] Step 6: After all components are positioned, the operator begins the clamping operation. First, the transverse clamping assembly 8 is activated. The operating lever of the first manual clamping plate assembly 81 is rotated, causing the clamping plates to push the left longitudinal beam plate 121 and the right longitudinal beam plate 122 from the outside in, clamping the longitudinal beam plates between the clamping plate and the ball bearing seat 52, thus achieving transverse fixation of the longitudinal beam plates at the position of the longitudinal positioning assembly 5. Simultaneously, the operating lever of the second manual clamping plate assembly 82 is rotated, causing the clamping plates to press the left longitudinal beam plate 121 and the right longitudinal beam plate 122 from the outside in, thus achieving transverse clamping at the front position of the rear positioning assembly 7.

[0046] Step 7: The operator adjusts the three clamping rods 91 of the vertical clamping assembly 9. By rotating the threaded structure on the hollow rod 92, the distance between the two clamping heads 93 is adjusted so that the clamping grooves 94 on the two clamping heads 93 respectively engage the tops of the left longitudinal beam plate 121 and the right longitudinal beam plate 122, fixing the distance between the left longitudinal beam plate 121 and the right longitudinal beam plate 122. At the same time, pressure is applied from above downwards to make the bottom of the longitudinal beam plate tightly fit the support point of the base assembly 1, thereby achieving vertical fixation of the longitudinal beam plate.

[0047] Step 8: The operator activates the front clamping assembly 10 and rotates the operating mechanism of the two horizontally arranged manual clamping plates 101, causing the clamping plates to push the sides of the left longitudinal beam plate 121 and the right longitudinal beam plate 122 from the outside, achieving side clamping. At the same time, the operator rotates the operating mechanism of the two longitudinally parallel manual clamping plates 101, causing the clamping plates to push the end faces of the left longitudinal beam plate 121 and the right longitudinal beam plate 122, achieving end face clamping.

[0048] Step 9: The operator activates the rear clamping assembly 11 and adjusts the two tilted clamping assemblies. Each clamping assembly contains two F-type clamps 111 arranged side by side. The operator passes the F-type clamps 111 through the mounting interface 142 of the semi-enclosed housing 141 and clamps the semi-enclosed housing 141 by rotating the threaded adjustment mechanism of the F-type clamps 111. This clamps the rear housing structure from multiple angles, ensuring stable clamping of the rear power and counterweight mounting area 14.

[0049] Step 10: After all clamping mechanisms are locked, the entire frame is precisely assembled and fixed by the tooling, and the spatial position and orientation of each component no longer change. The operator checks the status of each positioning and clamping point to confirm that all components are tightly fitted to their corresponding positioning surfaces and securely clamped, ensuring the required positioning accuracy before welding. At this point, the welder can perform welding operations on each weld seam of the frame according to the preset welding process, including the weld seam between the longitudinal beam plate and the reinforcing plate, the weld seam between the mounting support plate 16 and the longitudinal beam plate, and the weld seam between the semi-enclosed box 141 and the longitudinal beam plate. Because the tooling completely defines the position of each component and provides rigid support, the thermal deformation generated during welding is suppressed by the clamping force and rigid structure of the tooling, preventing component displacement and directly ensuring welding accuracy.

[0050] Step 11: After all welding operations are completed and the welds have cooled sufficiently, the operator releases each clamping mechanism in the reverse order of clamping. The fixture can then be immediately put into the positioning and clamping of the next machine frame without additional adjustment or calibration. The operator cleans the welding slag or debris from the surface of the fixture, checks the working status of each positioning and clamping component, and confirms that key components such as the positioning pin 61, positioning block 62, ball bearing seat 52, clamping plate, and F-type clamp 111 are intact, in preparation for the positioning and clamping of the next workpiece.

[0051] Throughout the welding process, the use of four sets of positioning components corresponding one-to-one with the key feature points of the frame, along with a multi-directional, multi-point clamping mechanism, ensures a high degree of standardization, ease of operation, and reliable welding accuracy. The collaborative positioning method—establishing a core benchmark with the reference positioning component 4, defining the longitudinal beam plate posture with the longitudinal positioning component 5, precisely positioning and installing the support plate 16 with the front positioning component 6, and controlling the rear structure with the rear positioning component 7—not only guarantees the spatial accuracy of individual components but also ensures the relative positional relationship and assembly accuracy between components. This is difficult to achieve with traditional welding fixtures, providing more comprehensive and accurate quality assurance. Simultaneously, the multi-directional clamping of the transverse clamping group 8, vertical clamping group 9, front clamping group 10, and rear clamping group 11 effectively suppresses welding thermal deformation and displacement caused by external forces, preventing dimensional deviations or torsional deformation of the frame after welding, thus greatly improving the stability and consistency of welding quality.

[0052] After welding is completed, the operator removes the formed frame, inspects the welding quality and dimensional accuracy, and prepares for the positioning and clamping of the next workpiece. The entire positioning, clamping, and welding process is fast and efficient, greatly improving the production efficiency and quality control level of engineering machinery frame manufacturing.

[0053] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any innovative improvements or substitutions based on this utility model should fall within the scope of the claims of this utility model. Furthermore, the parameters, materials, and processes mentioned in the above embodiments are not unique. Without departing from the technical essence of this utility model, those skilled in the art can make various alternative choices, and these alternative solutions should also be considered to fall within the scope of protection of this utility model.

Claims

1. A positioning and clamping fixture for welding the frame of engineering machinery, characterized in that, include: Base assembly; The positioning mechanism is installed on the base assembly. The positioning mechanism includes a reference positioning component, a longitudinal positioning component, a front positioning component, and a rear positioning component, which are set one-to-one with the key structures of the frame of the engineering machinery to be welded. They are used to coordinate and limit the spatial posture of each component of the frame. The clamping mechanism, which is mounted on the base assembly, includes multiple clamping units that cooperate with the positioning mechanism to lock the components of the frame in preset positioning positions in multiple directions.

2. The positioning and clamping fixture according to claim 1, characterized in that, The base assembly includes: Main supporting plate; Multiple reinforcing ribs welded to the underside of the main bearing plate to enhance resistance to deformation; Multiple sets of reference holes and threaded holes are pre-set on the main bearing plate and match the key feature points of the engineering machinery frame to be welded.

3. The positioning and clamping fixture according to claim 2, characterized in that, The reinforcing rib has a C-shaped cross-section and a base plate welded to its bottom surface. The base plate has bolt holes for connecting to the ground.

4. The positioning and clamping fixture according to claim 1, characterized in that, The reference positioning component includes: A circular positioning platform simulating the mounting surface of a slewing bearing; Multiple rectangular positioning components are located on the periphery of a circular positioning platform to achieve planar positioning; A Y-shaped positioning element that is detachably mounted on the base assembly for horizontal and vertical positioning of the frame.

5. The positioning and clamping fixture according to claim 4, characterized in that, The circular positioning platform has a stepped structure, including a hollow cylinder and a rectangular mounting block disposed below it; The Y-shaped positioning component includes two forked arms and a bottom surface. The two forked arms are used to pass through the rectangular through holes of the frame and abut against its lateral connecting parts. The bottom surface is used to abut against the inner side of the bottom surface of the frame.

6. The positioning and clamping fixture according to claim 1, characterized in that, The longitudinal positioning component includes: Support towers distributed along the length of the frame; Multiple ball bearing seats located on both sides of the support tower are used to support the longitudinal beam plates of the engineering machinery frame to be welded and provide a foundation for horizontal movement.

7. The positioning and clamping fixture according to claim 1, characterized in that, The front-end positioning component includes: Multiple locating pins for a rectangular bracket used to position the mounting plate from the top and sides; A positioning block located at the front end of the rectangular main board of the mounting bracket; Several pads are provided on the base assembly to assist in fixing the rectangular motherboard.

8. The positioning and clamping fixture according to claim 1, characterized in that, The backend positioning component includes: Two sets of positioning rod fixtures with different heights are arranged front and back along the overall length direction of the base. Each set of positioning rod fixtures includes multiple bases and positioning rods detachably mounted on the bases. The positioning rods are used to pass through the longitudinal beam plates of the frame. A manual push plate assembly, mounted on the base, for pushing the longitudinal beam plate to achieve lateral positioning, the manual push plate assembly includes a control lever and a push plate.

9. The positioning and clamping fixture according to claim 1, characterized in that, The clamping mechanism includes: The transverse clamping assembly is used to fix the longitudinal beam plate laterally; Vertical clamping assembly, used to fix the longitudinal beam plate vertically from the top; Front clamping assembly, used to secure the front area of ​​the frame; The rear clamping assembly is used to secure the rear power and counterweight mounting area of ​​the frame.

10. The positioning and clamping fixture according to claim 9, characterized in that, The lateral clamping assembly includes a first manual clamping plate assembly and a second manual clamping plate assembly, both of which include a control lever and a clamping plate; The vertical clamping assembly includes multiple clamping rods, each clamping rod comprising a hollow rod with threads at both ends and two clamping heads with clamping grooves; The front clamping assembly includes a manual clamping plate that is horizontally arranged and vertically parallel arranged; The rear clamping assembly includes an inclined clamping group, which includes multiple F-type clamps.

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