A hybrid structure frame for semi-trailer

Abstract

The present invention discloses a hybrid structure frame for a semi-trailer, wherein the plate beam frame at the traction pin adopts a double web structure, and the two longitudinal beams at the plate beam frame at the traction pin have the traction plates covering them as their lower wing plates, and a plurality of groove-shaped reinforcements are arranged between the two longitudinal beams, and the distance between the wing plates on the longitudinal beams or the upper cover plates on the traction pins and the traction plates is less than 90 mm; the through-type cross beams transversely penetrate the webs of the two longitudinal beams of the trapezoidal frame; the upper wing plates of the longitudinal beams at the plate beam frame part at the traction pin are wider than the upper wing plates of the trapezoidal frame part. The semi-trailer transport container of the present invention, which uses the plate beam frame with a total height of 88 mm of the plate beam structure at the traction pin as the skeleton, reduces the center of gravity height of the train by at least 100 mm, greatly reduces the total height of the train operation, and improves the driving stability and safety; in the transportation of large semi-trailer boxes and box-type semi-trailers, the effective volume is greatly increased, and the transportation efficiency is improved; and the transportation of international sea 40-foot standard containers is achieved without overheight.

Description

Technical Field

[0001] The invention relates to a mixed structure frame for a semitrailer, belonging to the technical field of semitrailer production. Background Art

[0002] In the frame design of freight vehicles (including semi-trailers and full trailers), the "ladder frame" is usually used (see Figure 1 ); It is composed of two longitudinal beams and several cross beams separated from each other; the characteristics of the ladder frame are: two longitudinal beams and two side beams with a relatively high “I”-shaped or trough-shaped cross section are designed in the longitudinal direction to bear the vertical load (bending resistance), and a cross beam with a smaller cross section is designed in the transverse direction (between the longitudinal beams and the side beams) to connect the longitudinal beams and the cross beams and bear the transverse load (torsion resistance); the longitudinal beams, side beams and cross beams form a frame with a trapezoidal or rectangular cross section. At present, the chassis of container-specific semi-trailer skeleton vehicles, semi-trailer boxes, van semi-trailer chassis and the chassis of most tank trucks all use the “ladder frame” as the main body for bearing loads, supporting and supporting, and the main body for walking.

[0003] Since the ladder frame adopts the design concept of longitudinal beams resisting bending and transverse beams resisting torsion, it can be known from theoretical mechanics and material mechanics that the load-bearing capacity of longitudinal beams and transverse beams is proportional to their cross-sectional coefficients. To improve their load-bearing (bending moment, torque) capacity, their cross-sectional coefficients must be increased. The cross-sectional coefficient itself is proportional to the cube of the height of the longitudinal beams and transverse beams themselves. Therefore, increasing the height of longitudinal beams and transverse beams has become the simplest and most effective means to increase the load-bearing capacity of longitudinal beams and transverse beams.

[0004] At present, the height of the saddle joint surface of the tractor is limited to a relatively high range by the technical level of the main engine manufacturer, which is basically 1.3 meters to 1.35 meters. The size of the ladder frame at the traction pin, which is the main body of the load-bearing, supporting and walking body, is generally 230 mm to 260 mm due to the strength and rigidity requirements required for bearing. This directly raises the height of the frame bearing surface. At this time, the height dimension available between the upper plane of the ladder frame at the traction pin and the upper limit of 4 meters of the regulations is very limited.

[0005] Although the load-bearing capacity of the chassis frame designed and manufactured in this way is greatly improved, its disadvantages are:

[0006] The high load-bearing plane reduces the effective height and effective carrying volume of the cargo during transportation at the height specified by laws and national standards (4 meters); the center of gravity of the vehicle is increased, and the driving stability is poor.

[0007] The consequences are:

[0008] In the international standard container transportation, the total height of the semi-trailer skeleton truck for containers carrying empty containers exceeds the limit. The height of the international ocean 40-foot standard container is 2.591 meters (8.5 feet), while the height of the international ocean 40-foot ultra-high container is 2.896 meters (9.5 feet); even if the tractor with the lowest traction saddle joint surface height (1.30 meters high) is matched with a skeleton truck with the lowest frame height of 230 mm at the traction pin to transport the standard container of the international ocean 40-foot standard container (2.591 meters high), its total operating height exceeds the national regulation of 4 meters and reaches 4.121 meters. If the tractor with the lowest traction saddle joint surface height (1.3 meters high) is matched with a skeleton truck with the lowest frame height of 230 mm at the traction pin to transport the international ocean 40-foot ultra-high container (2.896 meters high), its total operating height reaches 4.426 meters, which seriously exceeds the 4 meters specified by national regulations, resulting in 100% of the international ocean container trains running on the road exceeding the limit. Exceeding the height limit causes the center of gravity of the vehicle to be too high and driving stability to deteriorate, posing a huge safety hazard to road traffic.

[0009] When transporting a large semi-trailer box that cannot be disassembled, the height of the semi-trailer box at the towing pin will have to be reduced, sacrificing the height of the box directly above the towing pin and reducing the effective volume to meet the regulatory height limit of 4 meters.

[0010] Similarly, in the case of box-type semi-trailers, the height dimension of the box-type semi-trailer at the towing pin position has to be reduced, at the expense of the overall height dimension just above the towing pin and reducing the effective volume, in order to meet the regulatory height limit of 4 meters.

[0011] However, the semi-trailer boxes and van semi-trailers, which are vigorously promoted and advocated by the state and widely used in the logistics industry, have to sacrifice their due volume due to the aforementioned reasons, which directly causes profit loss of cargo owners and vehicle owners, seriously damages their vital interests, and causes a huge waste of social resources.

[0012] In view of the above-mentioned reality, the state has recently updated the corresponding national standards (see GB / T35782-2017 Technical Conditions for Road Trailer Transport Vehicles, Section 5.2.1 for details); for tractors, first of all, it is clearly required that: when the semi-trailer tractor is disconnected from the semi-trailer, the height of the fifth wheel joint surface H (see Figure 2 ) should be 1290mm~1320mm; the height H of the joining surface of the semi-trailer tractor for towing high container transport (see Figure 2 ) should be 1080mm~1110mm.

[0013] Article 4.1.3.3 of GB / T1589-2016 External dimensions, axle loads and mass limits for automobiles, trailers and automobile trains also specifies in detail the height limits of the saddle of a semi-trailer tractor transporting standard containers when it is unloaded: The height of the saddle of a semi-trailer tractor transporting standard containers when it is unloaded (the height of the center position of the traction kingpin) shall meet the following requirements:

[0014] The height of a semi-trailer tractor transporting a standard container with a height of 2591 mm should not exceed 1320 mm;

[0015] The height of a semi-trailer tractor transporting a standard container with a height of 28961mm should not exceed 1110mm.

[0016] At the same time, for semi-trailers, the standard GB / T35782-2017 Technical Conditions for Road Trailer Transport Vehicles, Section 6.2.3, the standard more clearly requires the corresponding size limits of the corresponding matching semi-trailers: "When the semi-trailer is unloaded, the height of the traction pin seat plate from the ground should be 1230mm~1250mm, and the height of the high container transport semi-trailer should be 1020mm~1040mm", and the closed-loop dimension chain formed in height when the vehicle is in operation (the tractor and the semi-trailer are connected) (see Figure 3 ), the mathematical expression of its dimension chain is: total height 4 meters ≥ H1 tractor's fifth wheel joint surface height (also the height of the semi-trailer's fifth wheel seat plate from the ground) + A (total height of the chassis frame at the fifth wheel plate) + B (height of the upper box or tank, etc.).

[0017] After the total height is limited, H1 is only smaller than the H value specified in the standard by the compression amount of the tractor's elastic element (leaf spring or airbag and tire) (generally between 60mm and 120mm, depending on the size of the load directly above); the dimension that truly produces actual economic benefits is the B value (the height of the upper box or tank, etc.); in order to increase the economically beneficial height dimension B, for height-sensitive professional container transport models, (corresponding international standards: the height of an ordinary standard 40-foot container is 2591mm; the height of a 40-foot ultra-high container is 2896mm), the National Announcement Management Regulations for Vehicles have added a mandatory maximum limit of A (the total height of the chassis frame at the towing pin plate): "For container transport semi-trailers that transport 40-foot and larger containers, if the upper plane of the frame is in a complete horizontal plane, the total height of the frame at the towing pin should not exceed 90mm".

[0018] For conventional ladder-shaped frames, it is almost impossible to reach the total height limit of the frame at the traction pin and realize the proper load-bearing and transportation functions by using the existing design ideas and the current mature ladder-shaped frame technical solutions. Under the current technical conditions, both government management departments and practitioners in the logistics industry are in urgent need of a breakthrough in the trailer technology in lowering the height of the traction part of the trailer frame to solve the problems existing in the existing technology. Summary of the invention

[0019] In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides a hybrid structure frame for a semi-trailer.

[0020] In order to achieve the above technical objectives, the technical solution adopted by the present invention is: a hybrid structure frame for a semi-trailer, which is composed of a plate beam frame at a traction pin, a ladder frame, and a through-type cross beam. The plate beam frame at the traction pin adopts a double web structure, and the two longitudinal beams located at the plate beam frame at the traction pin have the traction plates covering them as their lower wing plates, a front cross beam is arranged at the front ends of the two longitudinal beams, and a plurality of groove-shaped reinforcements are arranged between the two longitudinal beams. The traction pin upper cover plate is arranged between the longitudinal beam upper wing plates, and the distance height between the longitudinal beam upper wing plate or the traction pin upper cover plate and the traction plate is less than 90 millimeters; at the front part of the ladder frame near the connection between the plate beam frame and the traction pin, a through-type crossbeam transversely penetrates the webs of the two longitudinal beams of the ladder frame, and the length of the through-type crossbeam is less than or equal to the maximum outer width of the vehicle; below the rear part of the plate beam frame at the traction pin, two tail wing panels formed by the opening at the rear part of the traction plate cover the lower plane of the lower wing panels of the longitudinal beams on both sides of the ladder frame from the bottom; above the rear part of the plate beam frame at the traction pin, the traction pin upper cover plate is extended and consolidated with the through-type crossbeam; the upper wing panel of the plate beam frame part of the longitudinal beam at the traction pin is wider than the upper wing panel of the trapezoidal frame part.

[0021] Furthermore, the through-type cross beam is one or a combination of channel steel, I-beam, C-shaped steel, round steel, round tube, rectangular tube, square tube; and a plurality of reinforcing ribs or connecting blocks are respectively arranged between the two ends of the through-type cross beam and the side webs.

[0022] Furthermore, at the plate beam frame at the traction pin, two front longitudinal reinforcements parallel to the longitudinal beams, two rear longitudinal reinforcements parallel to the longitudinal beams, a traction pin cross reinforcement perpendicular to the two longitudinal beams and connecting the front longitudinal reinforcements and the rear longitudinal reinforcements, and a plate beam tail cross beam perpendicular to the two longitudinal beams and connecting the rear longitudinal reinforcements are arranged between the two longitudinal beams; the lower plane of the traction pin upper cover plate covers the front longitudinal reinforcements, the traction pin cross reinforcements, the rear longitudinal reinforcements, and the plate beam tail cross beam, and they are fixed together by plug welding to form a complete plate beam structure.

[0023] Furthermore, the front longitudinal reinforcement, the traction pin cross reinforcement, the rear longitudinal reinforcement, and the tail cross beam of the plate beam are all bent steel plates; the traction plate and the traction pin upper cover plate are cut from steel plates, the front longitudinal reinforcement is located between the two longitudinal beams and symmetrically located on both sides of the traction pin, the front longitudinal reinforcement is continuously welded to the traction plate, and is continuously welded to the combined front cross beam; the rear longitudinal reinforcement is located between the two longitudinal beams and symmetrically located on both sides of the traction pin, the rear longitudinal reinforcement is continuously welded to the traction plate, the rear longitudinal reinforcement is continuously welded to the traction pin cross reinforcement, the rear longitudinal reinforcement and the tail cross beam of the plate beam are continuously welded, and the tail cross beam of the plate beam and the traction plate are continuously welded.

[0024] Furthermore, the traction pin transverse reinforcement is located directly above the traction pin.

[0025] Furthermore, the upper plane of the traction pin upper cover plate is flush with the upper plane of the upper wing plates of the two longitudinal beams, and the left and right sides are connected to the inner sides of the upper wing plates of the two longitudinal beams. The distance height between the upper wing plate or the traction pin upper cover plate and the traction plate is equal, which is 88 mm.

[0026] Furthermore, the trapezoidal frame includes two longitudinal beams and a plurality of transverse beams installed between the two longitudinal beams, each of the longitudinal beams includes a longitudinal beam upper wing plate, two longitudinal beam reinforcing webs, a longitudinal beam web plate, and a longitudinal beam lower wing plate; the two longitudinal beam reinforcing webs are arranged in parallel and vertically installed on the lower plane of the longitudinal beam upper wing plate; the longitudinal beam web plate is connected between the longitudinal beam upper wing plate and the longitudinal beam lower wing plate, and a lower wing plate inclined toward the longitudinal beam upper wing plate is arranged at each end of the longitudinal beam lower wing plate, so that the longitudinal beam lower wing plate forms a trapezoid.

[0027] Furthermore, the height H of the plate beam frame at the traction pin is 88 mm, the thickness t1 of the upper wing plate or the upper cover plate of the traction pin is 16 mm, the thickness t2 of the traction plate is 16 mm, the thickness t3 of the front longitudinal reinforcement or the rear longitudinal reinforcement is 10 mm, the height h1 between the upper wing plate and the traction plate is equal to the height h2 between the upper cover plate of the traction pin and the traction plate. At this time, the width B of the plate beam frame at the traction pin is less than or equal to any value within the vehicle width of 2550 mm.

[0028] Furthermore, the hybrid structure frame for a semi-trailer, wherein the semi-trailer refers to: a container frame semi-trailer, a semi-trailer box semi-trailer, a van semi-trailer or a semi-trailer.

[0029] Furthermore, the manufacturing method of the hybrid structure frame for a semi-trailer comprises the following steps:

[0030] First, on the tooling, the manufactured traction plate and traction pin assembly are welded together according to the process requirements to complete the assembly of the traction plate and traction pin assembly of the traction part plate beam frame in the frame;

[0031] Second, on the tooling, the combined front cross beam is manufactured according to the design requirements, and the manufactured front cross beam, the traction plate and traction pin assembly manufactured in the previous process, as well as the front longitudinal reinforcement, the traction pin upper cross reinforcement, the rear longitudinal reinforcement, and the tail cross beam of the plate beam are assembled and welded according to the design requirements to complete the manufacturing of the plate beam body at the traction pin;

[0032] Third, on the tooling, assemble and weld the prepared longitudinal beam upper wing plate, longitudinal beam lower wing plate, longitudinal beam web plate, and longitudinal beam reinforcement web plate according to the design requirements to complete the production of the longitudinal beam;

[0033] Fourth, on the tooling, assemble and weld the two longitudinal beams and several cross beams according to the design requirements to complete the production of the ladder frame;

[0034] Fifth, on the tooling, assemble and weld the finished plate beam body at the traction pin and the finished trapezoidal frame together according to the design dimensions and process requirements to complete the production of the main frame structure;

[0035] Sixth, on the tooling, the completed traction pin upper cover is welded and fixed to the completed frame main structure according to the design requirements to complete the production of the frame.

[0036] The beneficial technical effects of the present invention are:

[0037] 1. The semi-trailer transports containers with a plate beam frame with a total height of 88 mm at the traction pin as the skeleton, which reduces the center of gravity height of the train by at least 100 mm, greatly reduces the total height of the train, and improves driving stability and safety;

[0038] 2. For large semi-trailer boxes that cannot be disassembled for transportation, the overall height of the semi-trailer box can be increased by at least 100 mm on the existing basis (under the same tractor); according to the national standard GB / T1589-2016, the width shall not exceed 2.55 meters and the length shall not exceed 13.75 meters, which can increase the internal volume by at least 3.32 cubic meters; for box-type semi-trailers, the national standard GB / T1589-2016 for box-type semi-trailers can also increase the internal volume by at least 3.32 cubic meters, greatly increasing the effective volume and improving transportation efficiency.

[0039] 3. A tractor with a traction saddle joint surface height of 1.32 meters that complies with national standards is used to transport 40-foot standard international shipping containers (2.591 meters high). The total operating height is only 3.999 meters, and the compression of elastic components such as suspension and tires has not yet been taken into account. It already meets the requirement of less than 4 meters, thus achieving the goal of not exceeding the height for transporting 40-foot standard international shipping containers. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The present invention is further described below in conjunction with the accompanying drawings.

[0041] Figure 1 It is a schematic diagram of a frame structure in the prior art;

[0042] Figure 2 It is a schematic diagram of the vehicle height size structure in the prior art;

[0043] Figure 3 It is a schematic diagram of a height dimension chain in the prior art;

[0044] Figure 4 It is a schematic top view of the structure of the present invention;

[0045] Figure 5 It is a schematic diagram of the main structure of the present invention;

[0046] Figure 6 For the present invention Figure 5 AA cross-sectional view of ;

[0047] Figure 7 It is a structural schematic diagram of the longitudinal beam assembly of the present invention;

[0048] Figure 8 AA cross-sectional structural schematic diagram of the longitudinal beam assembly of the present invention;

[0049] Fig. 9 It is a schematic diagram of the BB cross-sectional structure of the longitudinal beam assembly of the present invention;

[0050] Fig.10 It is a schematic diagram of the traction plate and traction pin structure of the present invention;

[0051] Fig.11 It is a schematic diagram of the local structure of the plate beam frame at the traction pin of the present invention;

[0052] Fig.12 It is a schematic diagram of the structure of the through-type crossbeam connection part of the present invention.

[0053] In the figure: 1. Plate beam frame at traction pin, 110. Front cross beam, 111. traction plate, 112. Upper cover plate of traction pin, 113. Front longitudinal reinforcement, 114. Cross reinforcement of traction pin, 115. Rear longitudinal reinforcement, 116. Tail cross beam of plate beam, 120. traction pin assembly, 2. Through cross beam, 210. Longitudinal beam, 211. Upper wing plate of longitudinal beam, 212. Strengthened web plate of longitudinal beam, 213. Web plate of longitudinal beam, 214. Lower wing plate of longitudinal beam, 3. Ladder frame. DETAILED DESCRIPTION

[0054] like Figure 4 , 5As shown, a hybrid structure frame for a semitrailer is composed of a plate beam frame 1 at a traction pin, a ladder frame 3, and a through-type cross beam 2. The plate beam frame 1 at the traction pin adopts a double web structure. Two longitudinal beams 210 located at the plate beam frame 1 at the traction pin have a traction plate 111 covering them as their lower wing plates. A front cross beam 110 is arranged at the front ends of the two longitudinal beams 210 located at the plate beam frame 1 at the traction pin. A plurality of groove-shaped reinforcements are arranged between the two longitudinal beams. A traction pin upper cover plate 112 is arranged between the longitudinal beam upper wing plates 211. The longitudinal beam upper wing plates 211 or the traction pin upper cover plate 112 and the traction plate The height of the distance between the plate beam frame 111 is less than 90 mm; at the front of the ladder frame 3 near the plate beam frame 1 connection at the traction pin, the through-type cross beam 2 horizontally penetrates the web 213 of the two longitudinal beams 210 of the ladder frame 3, and the length of the through-type cross beam 2 is less than or equal to the maximum outer width of the whole vehicle; below the tail of the plate beam frame 1 at the traction pin, two tail wing plates formed by the opening of the tail of the traction plate 111 cover the lower plane of the lower wing plate 214 of the longitudinal beams 210 on both sides of the ladder frame 3 from the bottom; above the tail of the plate beam frame 1 at the traction pin, the traction pin upper cover plate 112 is extended and fixed together with the through-type cross beam 2. Thus, the front plate beam structure of the frame and the rear trapezoidal structure are firmly and organically connected in three dimensions to form a complete semi-trailer assembly; the upper wing plate of the longitudinal beam 210 at the plate beam frame 1 at the traction pin is wider than the upper wing plate of the ladder frame 3.

[0055] The hybrid structure frame for a semi-trailer, wherein the semi-trailer refers to: a container frame semi-trailer, a semi-trailer box semi-trailer, a van semi-trailer or a semi-trailer.

[0056] like Fig.12 As shown, the through-type cross beam 2 is composed of one or a combination of channel steel, I-beam, C-shaped steel, round steel, round tube, rectangular tube, square tube; a number of reinforcing ribs or connecting blocks are respectively arranged between the two ends of the through-type cross beam 2 and the side web 213.

[0057] like Figure 4 , 10 As shown in 11, at the plate beam frame 1 at the traction pin, two front longitudinal reinforcements 113 parallel to the longitudinal beams, two rear longitudinal reinforcements 115 parallel to the longitudinal beams, a traction pin transverse reinforcement 114 perpendicular to the two longitudinal beams and connecting the front longitudinal reinforcements 113 and the rear longitudinal reinforcements 115, and a plate beam tail cross beam 116 perpendicular to the two longitudinal beams and connecting the rear longitudinal reinforcement 115 are arranged between the two longitudinal beams 210; the lower plane of the traction pin upper cover plate 112 covers the front longitudinal reinforcement 113, the traction pin transverse reinforcement 114, the rear longitudinal reinforcement 115, and the plate beam tail cross beam 116, and they are fixed together by plug welding to form a complete plate beam structure.

[0058] The front longitudinal reinforcement 113, the traction pin cross reinforcement 114, the rear longitudinal reinforcement 115, and the plate beam tail cross beam 116 are all bent steel plate parts; the traction plate 111 and the traction pin upper cover plate 112 are cut from steel plates; the front longitudinal reinforcement 113 is located between the two longitudinal beams and symmetrically located on both sides of the traction pin, the front longitudinal reinforcement 113 is continuously welded to the traction plate 111, and is continuously welded to the combined front cross beam 110; the rear longitudinal reinforcement 115 is located between the two longitudinal beams and symmetrically located on both sides of the traction pin, the rear longitudinal reinforcement 115 is continuously welded to the traction plate 111, the rear longitudinal reinforcement 115 is continuously welded to the traction pin cross reinforcement 114, the rear longitudinal reinforcement 115 and the plate beam tail cross beam 116 are continuously welded, and the plate beam tail cross beam 116 and the traction plate 111 are continuously welded.

[0059] The traction pin cross reinforcement 114 is located directly above the traction pin 120 .

[0060] The upper plane of the traction pin upper cover plate 112 is flush with the upper plane of the upper wing plates 211 of the two longitudinal beams 210, and the left and right sides are connected to the inner sides of the upper wing plates 211 of the two longitudinal beams 210. The distance between the upper wing plates 211 or the traction pin upper cover plate 112 and the traction plate 111 is equal in height, which is 88 mm.

[0061] like Figure 7 , 8 As shown in Figure 9, the trapezoidal frame 3 includes two longitudinal beams 210 and a plurality of cross beams installed between the two longitudinal beams, each of the longitudinal beams 210 includes a longitudinal beam upper wing plate 211, two longitudinal beam reinforcing webs 212, a longitudinal beam web 213, and a longitudinal beam lower wing plate 214; the two longitudinal beam reinforcing webs 212 are arranged in parallel and vertically installed on the lower plane of the longitudinal beam upper wing plate 212; the longitudinal beam web 213 is connected between the longitudinal beam upper wing plate 211 and the longitudinal beam lower wing plate 214, and a lower wing plate inclined toward the longitudinal beam upper wing plate is arranged at each end of the longitudinal beam lower wing plate 214, so that the longitudinal beam lower wing plate forms a trapezoid.

[0062] like Figure 6 As shown, the height H of the plate beam frame at the traction pin is 88 mm, the thickness t1 of the upper wing plate or the upper cover plate of the traction pin is 16 mm, the thickness t2 of the traction plate is 16 mm, the thickness t3 of the front longitudinal reinforcement or the rear longitudinal reinforcement is 10 mm, the height h1 between the upper wing plate and the traction plate is equal to the height h2 between the upper cover plate of the traction pin and the traction plate, and at this time, the width B of the plate beam frame at the traction pin is less than or equal to any value within the vehicle width of 2550 mm.

[0063] The purpose of the present invention is to develop a chassis for container transport skeleton vehicles, semi-trailer box chassis and van semi-trailer chassis, which has a traction plate beam structure with a total frame height of 88mm at the traction pin plate and a semi-trailer chassis with a trapezoidal structure at the rear. Figure 4 , Figure 5 As shown. The traction part (traction pin) plate beam structure frame has a total height of 88 mm. The frame chassis is similar to the traditional ladder frame (such as Figure 1 ) are similar; however, we first made a thinner design on the frame plate beam structure at the traction pin and correspondingly improved the bending and shear resistance (such as Figure 4 , Figure 5 , Figure 6 As shown in FIG. 1 ), a double web structure is adopted in the longitudinal beam part on both sides, and the upper wing plate is widened. The upper wing plate of the plate beam frame 1 part of the longitudinal beam 210 at the traction pin is wider than the upper wing plate of the trapezoidal frame 3 part, and the lower wing plate is omitted (as shown in FIG. Figure 4 , 8 As shown); the longitudinal beam 210 directly shares the traction plate 111 as its lower wing plate. In the middle of the two longitudinal beams 210, two groove-shaped bending parts and rear longitudinal reinforcements 115 are longitudinally arranged on the traction plate 111. Between the longitudinal beam upper wing plates, a traction pin upper cover plate 112 is arranged. The upper plane of the traction pin upper cover plate 112 is flush with the upper wing plate planes of the two longitudinal beams 210, and the left and right sides are connected to the inner side surfaces of the upper wing plates of the two longitudinal beams 210; the lower plane of the traction pin upper cover plate 112 covers the upper front longitudinal reinforcement 113, the traction pin transverse reinforcement 114, the rear longitudinal reinforcement 115 and the tail cross beam 116 of the plate beam; and the traction pin upper cover plate 112 is fixedly connected with the front longitudinal reinforcement 113, the traction pin transverse reinforcement 114, the rear longitudinal reinforcement 115 and the tail cross beam 116 of the plate beam in the form of plug welding to form a complete integral plate beam structure. Whether it is the longitudinal beams 210 on both sides or the groove-shaped bending part in the middle, the total height including the traction plate 111 and the traction pin upper cover plate 112 after being welded with the traction plate 111 and the traction pin upper cover plate 112 is 88 mm. In this way, under the premise of ensuring normal load-bearing, the total height of the plate beam structure frame of the traction pin part is 88 mm, which meets the national standard of less than 90 mm. In the middle front part of the trapezoidal frame, the through-type cross beam 3 transversely penetrates the webs 213 of the left and right longitudinal beams of the trapezoidal frame, and four web reinforcement plates 212 are fixedly connected to both sides of the front end of the through-type cross beam 3 close to the traction pin. Thereby, a firm and organic connection between the front plate beam structure and the rear trapezoidal structure frame in three dimensions is achieved, thereby forming a complete semi-trailer assembly.

[0064] The longitudinal beam reinforcement web is cut from a steel plate or a steel strip; the overlapping portion of the traction plate 111 and the longitudinal beam lower wing plate 214 can be connected by plug welding, continuous welding, or plug welding plus continuous welding; the traction plate upper cover plate 112 and the through cross beam 3 are continuously welded; the longitudinal beam upper wing plate 211 and the longitudinal beam reinforcement web 212 are continuously welded; the longitudinal beam upper wing plate 211 and the traction pin upper cover plate 112 are continuously welded; the longitudinal beam reinforcement web 212 and the traction plate 111 are continuously welded; the plate beam front longitudinal reinforcement 113 and the traction pin upper cross reinforcement 114 are continuously welded; the traction pin upper cross reinforcement 114 and the traction plate There is a continuous welding between 111; the vertical edge of the traction pin upper transverse reinforcement 114 is welded to the longitudinal beam web reinforcement plate 212 of the longitudinal beams on both sides; the transverse edge of the traction pin upper transverse reinforcement 114 is welded to the longitudinal beam upper wing plate 211 of the longitudinal beams on both sides; there is an intermittent circular plug weld between the traction pin upper cover plate 112 and the front longitudinal reinforcement 113 on the plate beam; there is an intermittent circular plug weld between the traction pin upper cover plate 112 and the traction pin upper transverse reinforcement 114; there is an intermittent circular plug weld between the traction pin upper cover plate 112 and the rear longitudinal reinforcement 115 on the plate beam; there is an intermittent circular plug weld between the traction pin upper cover plate 112 and the tail cross beam 116 of the plate beam.

[0065] The processing method is as follows:

[0066] First, on the tooling, the manufactured traction plate 111 and the purchased traction pin assembly 120 are welded together according to the process requirements to complete the assembly and production of the traction plate and traction pin welding assembly of the traction part plate beam frame in the hybrid frame;

[0067] Second, on the tooling, the combined front cross beam 110 manufactured according to the design requirements, the traction plate 111 manufactured in the previous process and the traction pin fixing cap are welded together, the front longitudinal reinforcement 113, the traction pin upper cross reinforcement 114, the rear longitudinal reinforcement 115, and the plate beam tail cross beam 116 are assembled and welded according to the design requirements to complete the manufacturing of the main body of the plate beam frame 1 at the traction pin;

[0068] Third, on the tooling, assemble and weld the manufactured longitudinal beam upper wing plate 211, longitudinal beam lower wing plate 214, longitudinal beam web plate 213, and longitudinal beam reinforcement web plate 212 according to the design requirements to complete the manufacture of the longitudinal beam 210;

[0069] Fourth, on the tooling, assemble and weld the two longitudinal beams 210 and a plurality of cross beams according to the design requirements to complete the manufacture of the ladder frame 3;

[0070] Fifth, on the tooling, the main body structure of the plate beam frame 1 at the traction pin that has been manufactured is assembled and welded with the ladder frame 3 that has been manufactured according to the design dimensions and process requirements to complete the manufacture of the main body structure of the frame;

[0071] Sixth, on the tooling, the completed traction pin upper cover plate 112 is welded and fixed to the completed frame main structure according to the design requirements to complete the manufacture of the frame.

[0072] From the structure of the car, we know that the main load-bearing part of the vehicle is the chassis frame; all external loads on the vehicle are resisted, absorbed and borne by the chassis frame. The ability of the chassis frame to resist, absorb and bear the bending moment, torque and shear stress is the symbol of the chassis frame's load-bearing capacity, which is also the symbol of the vehicle's load-bearing capacity.

[0073] From theoretical mechanics and material mechanics, we know that when a vehicle is running with external loads, all external input loads (cargo mass, ground support reaction force transmitted from the suspension, tire braking force, bumps and impacts caused by uneven road surface, and left and right unbalanced moments, etc.) are converted into bending moments, torques, and shear stresses of the vehicle's load-bearing body - the chassis frame.

[0074] Under the same external loads, operating conditions and materials used to manufacture the chassis frame, the ability of the chassis frame to resist bending, torsion and shear is an indicator of the chassis frame's load-bearing capacity and its advancement.

[0075] 1. From the material mechanics, we know that: apart from the material factor, the bending resistance of a certain position of the chassis frame is proportional to the bending resistance coefficient of the cross section at that position; that is, the larger the bending resistance coefficient of the cross section at a certain position of the chassis frame, the stronger the bending resistance of the chassis frame at this cross section position. The bending resistance coefficient of the cross section is only related to the shape and size of the cross section; from the material mechanics, we know that the bending resistance coefficient of the cross section at any position is proportional to the width dimension of the cross section, proportional to the cube of the distance dimension from the farthest point in the height direction of the cross section to the neutral axis of the cross section; and proportional to the first power of the width dimension of the cross section. Because of this relationship, in the usual design, the method of increasing the cross section dimension is used to improve the bending resistance of the chassis frame; although the cubic relationship of the height dimension is simple and efficient, the consequence is that the load-bearing surface is too high. In the case of limiting the height dimension of the cross section, the bending resistance of the chassis frame at this position can also be improved by widening the width dimension of the cross section; it just needs to be based on the first power relationship. In other words, by compressing the height dimension of the cross section and stretching the width dimension of the cross section, the shape of the cross section becomes flat, that is, a plate-type beam structure is made. As long as the width dimension is sufficient, the bending section coefficient of the cross section can be kept unchanged or even increased; thereby improving the bending resistance of the chassis frame. The argument is as follows:

[0076] Under the current regulations and national standards, the total mass of a semi-trailer (deadweight + load) is not allowed to exceed 40 tons (GB / T1589-2017 Table 4 Maximum allowable total mass limit for automobiles, trailers and automobile trains); the minimum deadweight is set at 4 tons, and the maximum load is 36 tons; from theoretical mechanics, it can be seen that under extreme conditions, the vertical load at the semi-trailer traction pin will not exceed 16 tons. When the dynamic load coefficient is taken to 1.5, the vertical load at the traction pin is 24 tons; the maximum bending moment acting on it is the product of the vertical load and the front overhang, which is 24000X9.8 Newtons*1.593 meters (according to GB1589-2016 Section 4.1.3 .1 The front turning radius of the semi-trailer should not be greater than 2040mm, and the width of 2550mm in the maximum limit of the outer dimensions of other vehicles, trailers and vehicle trains in Table 2, and the maximum front overhang is deduced to be 1592.4mm) According to the high-strength steel material Q690M (yield limit = 690Mpa when the thickness is ≤16mm; extracted from GB1591-2018 low-alloy high-strength structural steel) commonly used in the current market for making chassis frames, and in accordance with the dimensions specified in Table 2 (maximum limits of the outer dimensions of other vehicles, trailers and vehicle trains) of GB / T1589-2016 (outer width not greater than 2550mm) to design and manufacture the chassis frame:

[0077] From the material mechanics, we know that in the longitudinal force plane of the vehicle (forward direction), the frame as a whole can be simplified as a simply supported beam with a cantilever. The fulcrums correspond to the traction pin and the suspension fulcrum respectively. As for the bending resistance: According to the aforementioned theoretical mechanics analysis and material mechanics calculations, it can be concluded that: at this time, when the bending section coefficient of the cross section of the plate beam frame at the traction pin meets the vehicle curb mass of 40 tons, its minimum bending section coefficient is:

[0078] 1): not less than 791 cm³----when the plate thickness is ≤16mm (yield limit = 690Mpa, the allowable stress is 0.7 times the yield limit). When selecting the general high-strength steel Q690M, combined with Figure 4 , Figure 6 As shown, under the condition that the height is limited to 88mm and under current regulations, the value of B can be any value within the range of less than or equal to the maximum vehicle width limit of 2550mm.

[0079] 2): When B=900mm; H=88mm; t1=16mm; t2=16mm; t3=10mm, h1=h2=56mm; according to material mechanics calculations, it can be seen that the bending section coefficient of the cross-section of the plate beam frame at the traction pin has reached 882 cm³, which is 1.15 times the minimum bending section coefficient of 791 cm³ under extreme conditions.

[0080] 3): When B=1200mm; H=88mm; t1=16mm; t2=16mm; t3=10mm, h1=h2=56mm; according to material mechanics calculations, the bending section coefficient of the plate beam frame cross section at the traction pin has reached 1169 cm³, which is 1.47 times the minimum bending section coefficient of 791 cm³ under extreme conditions.

[0081] From the above calculation results, it can be seen that: under the condition of meeting the vehicle curb mass of 40 tons, the bending resistance required when the total height of the plate beam frame at the traction pin is 88mm can be easily achieved by adjusting the width of the plate beam.

[0082] 2. As for the torsion resistance, it is known from material mechanics that the torsion resistance of a certain position of the chassis frame is proportional to the torsion resistance section coefficient of the section; and the torsion resistance section coefficient of the cross section is also a quantity related only to the size of the section. Its torsion resistance section coefficient is proportional to the cube of its diameter of rotation. For the chassis frame, the external load is bending moment in the longitudinal direction and torque in the transverse direction; its torsion resistance is reflected in its ability to resist the torsional stress along the longitudinal center (line or plane) of the frame. In other words, the wider the chassis frame is, the stronger its ability to resist torsional moment. Therefore, to reduce the height dimension of a certain position of the chassis frame and maintain or even increase the torsion resistance of the chassis frame at that position, it is only necessary to increase the width dimension of the components that make up the cross section at the cross section perpendicular to the longitudinal direction of the chassis frame and the thickness specification of the components themselves, so as to maintain or even improve the torsion resistance of the position. This is precisely the advantage of the plate beam. The specific arguments are as follows:

[0083] According to theoretical mechanics and material mechanics, under the extreme working conditions of the national standard, the plate beam frame at the traction pin is subjected to torque in the width direction, which is equivalent to the bending moment generated by the couple formed by the torque applied on the longitudinal center plane of the plate beam frame; the maximum force value is the aforementioned 24 tons including the impact load, and the moment is half of the vehicle width, 1275mm; the maximum bending moment is: 24000 Newtons * 1.275 meters; under this working condition, according to the aforementioned theoretical mechanics analysis and material mechanics calculation, it can be concluded that: combined with Figure 4 , Figure 6 , Figure 7 At this time, when the bending section coefficient of the longitudinal center plane of the plate beam frame at the traction pin meets the vehicle curb mass of 40 tons, its minimum bending section coefficient is:

[0084] 1): Not less than 634cm³---When the plate thickness is ≤16mm (yield limit = 690Mpa, the allowable stress is 0.7 times the yield limit).

[0085] 2): When H=88mm; t1=16mm; t2=16mm; t3=10mm, h1=h2=56mm; According to material mechanics calculation, the bending section coefficient of the longitudinal center plane of the plate beam frame at the traction pin has exceeded 3336 cm³; it is more than 5.26 times the minimum bending section coefficient of 634 cm³ under extreme conditions. That is, when the length of the lower traction plate 111 and the traction pin upper cover plate 112 is not less than 3462mm (such as Figure 7 As shown in the figure), the longitudinal torsional section of its plate beam frame is sufficiently safe.

[0086] 3): Based on the minimum bending section coefficient of 634 cm³, the minimum length of the traction plate 111 and the upper cover of the traction pin is inferred, and the length of the traction plate 111 and the upper cover of the traction pin is 641mm; however, combined with the maximum allowable axle load limits of single-axle, two-axle group and three-axle group of automobiles and trailers in Table 3 of "GB / T1589-2016 External Dimensions, Axle Loads and Mass Limits of Automobiles, Trailers and Automobile Trains", and the provisions of clause 4.1.3.2: "The horizontal distance from the center axis of the semi-trailer traction pin to the rear end of the semi-trailer vehicle length should not be greater than 12000mm (except for semi-trailers transporting 45ft containers)"; it can be known that the front overhang of the traction pin will not be less than 450mm, and the traction plate size behind the traction pin will not be less than 400mm long (required for the combined area with the traction saddle). Therefore, the length of the traction plate 111 and the length of the upper cover of the traction pin will be greater than 850mm at the minimum. That is, in the minimum state, the longitudinal torsion section of the plate beam structure at the traction pin is safe enough.

[0087] 3. As for the shear resistance, it is known from the mechanics of materials that the shear resistance of any section on the chassis frame is only related to the size of its cross-sectional area; the larger the cross-sectional area, the stronger the shear resistance of the section. In short, if you need to reduce the height of a section without reducing its shear resistance, you only need to increase the width of the section or increase the thickness of the cross-sectional components to keep the area of ​​the entire section unchanged.

[0088] According to theoretical mechanics and material mechanics, under the extreme working conditions of the national standard, the maximum vertical load borne by the plate beam frame at the traction pin is 24 tons including the impact load. Under this working condition, according to the theoretical mechanics analysis and material mechanics calculation, it can be concluded that: Figure 4 , Figure 6 At this time, when the shear cross-sectional area of ​​the plate beam frame at the traction pin meets the vehicle curb mass of 40 tons, its minimum cross-sectional area is:

[0089] 1): Not less than 6.95cm² --- Plate thickness ≤ 16mm (yield limit = 690Mpa, allowable shear stress is 0.5 times the yield limit).

[0090] 2): When B=900; H=88mm; t1=16mm; t2=16mm; t3=10mm, h1=h2=56mm; according to material mechanics calculations, the shear cross-sectional area of ​​the longitudinal center plane of the plate beam frame at the traction pin has exceeded 310 cm², which is more than 44 times the minimum shear cross-sectional area of ​​6.95 cm² under extreme conditions.

[0091] 4. Comprehensive analysis of the above three capabilities shows that reducing the height of any section of the chassis frame while maintaining or even improving the bending, torsion and shearing capabilities of the original section can be achieved by widening the width of the components of the section perpendicular to the longitudinal direction of the chassis frame and adjusting the thickness of the components themselves, that is, making a plate-type beam structure. By analogy, any section of the chassis frame in the longitudinal direction can be reduced in height by the above means while maintaining or even improving the bending, torsion and shearing capabilities of the original section. Even if all of them are replaced by plate-type beam structures, the bearing capacity of the original section can be maintained or even improved.

[0092] The beneficial technical effects of the present invention are:

[0093] 1. The semi-trailer transporting containers with a plate beam frame with a total height of 88 mm at the traction pin as the skeleton can greatly reduce the total height of the train. The tractor with a traction saddle joint surface height of 1.32 meters that meets the national standard is used to transport the international shipping 40-foot standard container (2.591 meters high). The total operating height is only 3.999 meters. At this time, the compression of elastic components such as suspension and tires has not been taken into account, which has met the requirement of less than 4 meters, and the transportation of international shipping 40-foot standard containers does not exceed the height.

[0094] The height of the 40-foot ultra-high container for international shipping is 2.896 meters (9.5 feet); if a tractor with a traction saddle joint surface height of 1.08 to 1.11 meters that meets the national standard is used to transport the standard container (2.896 meters high) of the 40-foot standard container for international shipping, its total operating height is only 4.064 meters to 4.096 meters. This height is the geometric superposition of the dimensions under the unloaded state, and does not take into account the result of the elastic suspension and elastic rubber tires of the tractor and semi-trailer due to the compression under the load. In the actual operation process, the elastic suspension and elastic rubber tires will definitely be compressed, and the compression amount when unloaded will also exceed 65 mm. Therefore, the overall height of the train can not exceed the 4-meter height specified by national regulations.

[0095] 2. For transporting large semi-trailer boxes that cannot be disassembled, the overall height of the semi-trailer box can be increased by at least 100 mm on the existing basis (under the same tractor); under the current national standard (GB / T1589-2016), the width does not exceed 2.55 meters, and the length does not exceed 13.75 meters; at least 3.32 cubic meters of internal volume can be increased (length 13.55 meters * width 2.45 meters * height 0.1 meters). This greatly increases the effective volume and improves transportation efficiency.

[0096] 3. Similarly, in terms of van semi-trailers, under the current national standard (GB / T1589-2016), the internal volume of van semi-trailers can also be increased by at least 3.32 cubic meters (length 13.55 meters * width 2.45 meters * height 0.1 meters), which greatly increases the effective volume and improves transportation efficiency.

[0097] 4. The center of gravity of the train is lowered by at least 100mm, improving driving stability and safety.

[0098] The above embodiments are merely used as explanations of the technical solutions of the present invention and cannot be used as limitations of the technical solutions of the present invention. Any simple improvements based on the present invention fall within the protection scope of the present invention.

Claims

1. A hybrid structure frame for a semi-trailer, consisting of a plate beam frame at a traction pin, a ladder frame, and a through-type cross beam, characterized in that: The plate beam frame at the traction pin adopts a double web structure, and the traction plate as its lower wing plate covers the two longitudinal beams located at the plate beam frame at the traction pin. A front crossbeam is arranged at the front end of the two longitudinal beams. A plurality of groove-shaped reinforcements are arranged between the two longitudinal beams. A traction pin upper cover plate is arranged between the longitudinal beam upper wing plates. The distance between the longitudinal beam upper wing plate or the traction pin upper cover plate and the traction plate is less than 90 mm. At the front of the trapezoidal frame near the connection between the plate beam frame at the traction pin, a through crossbeam transversely penetrates the webs of the two longitudinal beams of the trapezoidal frame. The length of the through crossbeam is The width is less than or equal to the maximum outer width of the vehicle; below the tail of the plate beam frame at the traction pin, two tail wing panels formed by the opening of the tail of the traction plate cover the lower plane of the lower wing panels of the longitudinal beams on both sides of the trapezoidal frame from the bottom; above the tail of the plate beam frame at the traction pin, the traction pin upper cover plate is extended and consolidated with the through-type cross beam; the upper wing panel of the longitudinal beam at the plate beam frame part at the traction pin is wider than the upper wing panel of the trapezoidal frame part; at the plate beam frame at the traction pin, two front longitudinal reinforcements parallel to the longitudinal beams and two rear longitudinal reinforcements parallel to the longitudinal beams are arranged between the two longitudinal beams. reinforcement, a traction pin transverse reinforcement perpendicular to the two longitudinal beams and connecting the front longitudinal reinforcement and the rear longitudinal reinforcement, and a plate beam tail cross beam perpendicular to the two longitudinal beams and connecting the rear longitudinal reinforcement; the lower plane of the traction pin upper cover plate covers the front longitudinal reinforcement, the traction pin transverse reinforcement, the rear longitudinal reinforcement, and the plate beam tail cross beam, and is fixed together by plug welding to form a complete plate beam structure; the traction pin transverse reinforcement is located directly above the traction pin; the upper plane of the traction pin upper cover plate is flush with the upper plane of the two longitudinal beams, and the left and right sides are flush with the inner sides of the upper wing plates of the two longitudinal beams The upper wing plate or the upper cover plate of the traction pin is connected to the traction plate, and the distance height between the upper wing plate or the upper cover plate of the traction pin is equal to 88 mm; the height H of the plate beam frame at the traction pin is 88 mm, the thickness t1 of the upper wing plate or the upper cover plate of the traction pin is 16 mm, the thickness t2 of the traction plate is 16 mm, the thickness t3 of the front longitudinal reinforcement or the rear longitudinal reinforcement is 10 mm, the height h1 between the upper wing plate and the traction plate is equal to the height h2 between the upper cover plate of the traction pin and the traction plate, and at this time, the width B of the plate beam frame at the traction pin is less than or equal to any value within the vehicle width of 2550 mm.

2. The hybrid structure frame for a semi-trailer according to claim 1, characterized in that: The through-type cross beam is made of one or a combination of channel steel, I-beam, C-shaped steel, round steel, round tube, rectangular tube, square tube; a plurality of reinforcing ribs or connecting blocks are respectively arranged between the two ends of the through-type cross beam and the side webs.

3. The hybrid structure frame for a semi-trailer according to claim 1, characterized in that: The front longitudinal reinforcement, the traction pin cross reinforcement, the rear longitudinal reinforcement, and the tail cross beam of the plate beam are all bent steel plates; the traction plate and the traction pin upper cover plate are cut from steel plates, the front longitudinal reinforcement is located between the two longitudinal beams and symmetrically located on both sides of the traction pin, the front longitudinal reinforcement is continuously welded to the traction plate, and is continuously welded to the combined front cross beam; the rear longitudinal reinforcement is located between the two longitudinal beams and symmetrically located on both sides of the traction pin, the rear longitudinal reinforcement is continuously welded to the traction plate, the rear longitudinal reinforcement is continuously welded to the traction pin cross reinforcement, the rear longitudinal reinforcement and the tail cross beam of the plate beam are continuously welded, and the tail cross beam of the plate beam and the traction plate are continuously welded.

4. The hybrid structure frame for a semi-trailer according to claim 1, characterized in that: The trapezoidal frame includes two longitudinal beams and a plurality of transverse beams installed between the two longitudinal beams, each of the longitudinal beams includes an upper longitudinal wing plate, two longitudinal beam reinforcing webs, a longitudinal beam web, and a longitudinal beam lower wing plate; the two longitudinal beam reinforcing webs are arranged in parallel and vertically installed on the lower plane of the longitudinal beam upper wing plate; the longitudinal beam web is connected between the longitudinal beam upper wing plate and the longitudinal beam lower wing plate, and a lower wing plate inclined toward the longitudinal beam upper wing plate is arranged at each end of the longitudinal beam lower wing plate, so that the longitudinal beam lower wing plate forms a trapezoid.

5. The hybrid structure frame for a semi-trailer according to claim 1, characterized in that: The hybrid structure frame for a semi-trailer, wherein the semi-trailer refers to: a container frame semi-trailer, a semi-trailer box semi-trailer, a van semi-trailer or a semi-trailer.

6. The method for manufacturing a hybrid structure frame for a semitrailer according to claim 1, characterized in that: Here are the steps: First, on the tooling, the manufactured traction plate and traction pin assembly are welded together according to the process requirements to complete the assembly of the traction plate and traction pin assembly of the traction part plate beam frame in the frame; Second, on the tooling, the combined front cross beam is manufactured according to the design requirements, and the manufactured front cross beam, the traction plate and traction pin assembly manufactured in the previous process, as well as the front longitudinal reinforcement, the traction pin upper cross reinforcement, the rear longitudinal reinforcement, and the tail cross beam of the plate beam are assembled and welded according to the design requirements to complete the manufacturing of the plate beam body at the traction pin; Third, on the tooling, assemble and weld the prepared longitudinal beam upper wing plate, longitudinal beam lower wing plate, longitudinal beam web plate, and longitudinal beam reinforcement web plate according to the design requirements to complete the production of the longitudinal beam; Fourth, on the tooling, assemble and weld the two longitudinal beams and several cross beams according to the design requirements to complete the production of the ladder frame; Fifth, on the tooling, assemble and weld the finished plate beam body at the traction pin and the finished trapezoidal frame together according to the design dimensions and process requirements to complete the production of the main frame structure; Sixth, on the tooling, the completed traction pin upper cover is welded and fixed to the completed frame main structure according to the design requirements to complete the production of the frame.

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