SEMITRAILER SUSPENSION AXLE BEAM

Abstract

The utility model relates to the field of transport engineering, namely to the structural elements of the chassis of semi-trailers, in particular to suspension beams with trunnions made in the form of a solid hollow element of tubular cross-section. The technical result is an increase in the reliability of the axle beam for semi-trailers, which is achieved due to the fact that the axle beam of the semi-trailer suspension, made in the form of a solid hollow element of tubular cross-section, includes a central section, on the sides of which are transition sections, on the sides of which are end sections, at the ends of the beam on the end sections there are trunnions, on the transition sections, in the transition zone from the central section to the trunnions, as well as on the end sections, the inner wall of the beam has a thickening, characterized in that the ratio of the length of the central section to the total length of the beam is from 0.7 to 0.83;the ratio of the length of the end section to the length of the transition and end sections together is from 0.65 to 0.9; the ratio of the internal diameter of the pipe of the central section to the external diameter is from 0.6 to 0.87; the ratio of the minimum external diameter of the end section to the maximum external diameter of the end section is from 0.73 to 0.96. 9 clauses, 7 figs.;

Description

[0001] The utility model relates to the field of transport engineering, namely to the structural elements of the chassis of semi-trailers, in particular to suspension beams with trunnions made in the form of a solid hollow element of tubular cross-section [B60B 35 / 10, B60B 35 / 12, B60G 7 / 00].

[0002] The prior art discloses a METHOD FOR FORMING A SOLID AXLE AND A HORIZONTAL HYDRAULIC PRESS FOR ITS IMPLEMENTATION [CN 1911548 A, publication date: 14.02.2007], which includes the following process steps:

[0003] a) Material selection: determining the diameter and length of the tubular blank for the solid axle;

[0004] b) Forming: Heating one end of the selected pipe blank and forming it with a die (stamp) by extrusion method, then heating the other end and forming it with a die by extrusion method.

[0005] The disadvantage of the analogue is that the formation of journals by extrusion method alternately from both sides of the pipe leads to asymmetry of the stress-strain state of the metal and an increased risk of internal microdefects in the transition zone from the central part to the journal.

[0006] Also known from the prior art is a METHOD FOR MANUFACTURING A SINGLE AXLE HOUSING [EP 0 941 783 A1, publication date: 09 / 15 / 1999] in which a tubular blank in the area of ​​the formed journal is reduced to the journal diameter by mechanical deformation, characterized by the following stages:

[0007] a) securing the tubular workpiece in a workpiece holding device that withstands at least axial compressive forces;

[0008] b) upsetting the tubular blank in the area of ​​the formed journal by axial compression, wherein the wall thickness in the upsetting area increases in comparison with the remaining wall thickness of the tubular blank;

[0009] c) radial forging of the upset zone, whereby the outer diameter of the pipe is reduced to the required journal diameter.

[0010] The disadvantage of the analogue is that the sequential execution of upsetting and radial forging operations leads to an uneven distribution of the metal across the wall thickness and the emergence of zones with increased internal stresses at the transition from the central part to the journal.

[0011] The closest in technical essence is the EQUIPMENT FOR EXTRUSION FORMING OF A SOLID TUBULAR AXLE OF A SEMI-TRAILER AND A FORMING METHOD [CN 102172658 A, publication date: 09 / 07 / 2011] containing a hydraulic press and a medium-frequency induction heating furnace, characterized in that:

[0012] At both ends of the hydraulic press frame, the first slider and the second slider are located respectively,

[0013] The first slider is connected to the first cylinder of the hydraulic press,

[0014] The second slider is connected to the second cylinder of the hydraulic press,

[0015] The first and second sliders are equipped with rotary disks for changing stamps;

[0016] There is also a pipe clamping device on the top of the hydraulic press bed.

[0017] The main technical issue with the prototype is that it does not provide a high level of beam reliability. The presence of rotating disks for changing dies on the hydraulic press sliders complicates the equipment design and reduces the accuracy of die alignment relative to the workpiece axis, leading to asymmetrical trunnion formation and uneven wall thickness. Furthermore, the prototype does not specify the geometric proportions of the final product that would allow it to withstand various types of loads while maintaining the required reliability.

[0018] The purpose of the utility model is to eliminate the shortcomings of the prototype.

[0019] The technical result is to increase the reliability of the axle beam for semi-trailers.

[0020] The specified technical result is achieved due to the fact that the beam of the axle of the semi-trailer suspension, made in the form of a solid hollow element of tubular section, includes a central section, on the sides of which there are transition sections, on the sides of which there are end sections, at the ends of the beam on the end sections there are trunnions, on the transition sections, in the transition zone from the central section to the trunnions, as well as on the end sections, the inner wall of the beam has a thickening, characterized in that

[0021] The ratio of the length of the central section to the total length of the beam is from 0.7 to 0.83;

[0022] the ratio of the length of the end section to the length of the transition and end sections together is from 0.65 to 0.9;

[0023] the ratio of the inner diameter of the pipe of the central section to the outer diameter is from 0.6 to 0.87;

[0024] The ratio of the minimum outer diameter of the end section to the maximum outer diameter of the end section is from 0.73 to 0.96.

[0025] In particular, the beam is made in the form of a solid metal hollow element.

[0026] In particular, the transition section is made with a step change in the outer diameter of the pipe.

[0027] In particular, at the ends of the beam, stepped transitions are made from a smaller outer diameter at the edge of the pipe to a larger one.

[0028] In particular, the thickening of the inner wall at the transition and end sections is made with a smooth change in the internal diameter of the pipe, while when moving from the central part to one of the ends of the beam, the internal diameter of the pipe first decreases, then increases.

[0029] In particular, the journals have seats for bearings.

[0030] In particular, the trunnions at the ends of the beam and the transition elements are located symmetrically with respect to the vertical axis of symmetry of the beam.

[0031] In particular, the journals and transition elements are made of hot-formed steel.

[0032] In particular, the beam is made of 18KhGT steel.

[0033] In particular, the transitions from one diameter to another between the transition and end elements are made radial.

[0034] Brief description of drawings.

[0035] Fig. 1 shows a general view of a variant of the blank of the axle beam of the semi-trailer suspension.

[0036] Fig. 2 shows a sectional view of a blank of a variant of a beam of an axle of a semi-trailer suspension.

[0037] Fig. 3-4 shows a variant of the beam of the axle of the semi-trailer suspension with stepped transitions for threads at the ends of the beam.

[0038] Fig. 5-6 shows a variant of the axle beam of a semi-trailer suspension with stepped transitions for bearings

[0039] Fig. 7 shows a variant of a radius transition from a transition to an end element.

[0040] In Fig. 1 the following are indicated: 1 – central element; 2 – transition element; 3 – end element.

[0041] In Fig. 2 the following are indicated: D – outer diameter of the central part of the pipe; D1 – minimum outer diameters of the end sections; D2 – maximum outer diameters of the compressed journals of the workpiece (maximum outer diameters of the end sections); D3 – inner diameter of the central part of the pipe; L – beam length; L1 – length of the central part; L2 – length of the transition and end section; L3 – length of the end section.

[0042] In Fig. 3,5 the following are indicated: D – outer diameter of the central part of the pipe; D1 – minimum outer diameters of the end sections (diameter of the axle beam journals for the threads at the ends of the beam); D2 – maximum outer diameters of the end sections (diameters of the axle beam journals for the bearing); D3 – inner diameter of the central part of the pipe; L1 – length of the central part; L2 – length of the transition and end section; L3 – length of the end section (length of the journal for the bearing with the threaded section for the hub nut); L4 – length of the journal for the bearing.

[0043] Implementation of a utility model

[0044] The axle beam with trunnions is a single all-metal element of tubular cross-section with heat-seated and machined stepped trunnions along the outer diameters at the ends of the tube with zones for bearings with variable inner diameters and wall thicknesses.

[0045] The beam is formed from a heat-compressed blank, which has the following characteristics: the length of the central section 1 is related to the total length of the beam L as L1 / L = 0.7…0.83. The length of the end section 3 is related to the length of the transition section 2 and the end section 3 together as L3 / L2 = 0.6…0.9. The minimum outer diameter of the end section 3 is related to the maximum outer diameter of the end section 3 (the degree of narrowing of the journal) as D1 / D2 = 0.92…0.98. The inner diameter of the pipe of the central section 1 is related to the outer diameter of the central section 1 as D3 / D = 0.6…0.87.

[0046] The D1 / D2 range of 0.92 to 0.98 is selected to ensure a smooth transition and metal accumulation in the thickening zone. These values ​​create a molding slope, which also serves to improve uniform pressing and facilitate removal of the axle beam from the mold after heat pressing.

[0047] The axle beam of the semitrailer suspension comprises a central section 1, two transition sections 2 located on the sides of the central section 1, and two end sections 3 located on the sides of the transition sections 2. The end sections 3 are provided with trunnions. The transition sections 2 connect the central section 1 with the end sections 3. The inner wall of the beam has a thickening on the transition sections 2 in the transition zone from the central section 1 to the trunnions, as well as on the end sections 3.

[0048] The beam is made in the form of a solid hollow element of tubular section.

[0049] The heat-compressed machined beam (Fig. 3-6) has the following characteristics:

[0050] The length of the central section 1 is related to the total length of the beam L as L1 / L = 0.7…0.83.

[0051] The length of end section 3 is related to the length of transition section 2 and end section 3 together as L3 / L2 = 0.65…0.9.

[0052] The inner diameter of the pipe of the central section 1 is related to the outer diameter of the central section 1 as D3 / D = 0.6…0.87.

[0053] The maximum outer diameter of end section 3 is related to the minimum outer diameter of end section 3 as D1 / D2 = 0.73…0.96.

[0054] The dimensions of the axle beam lengths depend on the wheel track size, and the bearing diameters, hub nut threads and wall thickness depend on the design load.

[0055] In the embodiment, the beam is made in the form of a solid metal hollow element.

[0056] In the embodiment, the transition section 2 is made with a stepwise change in the outer diameter of the pipe.

[0057] In the embodiment, at the ends of beam 3, stepped transitions are made from a smaller outer diameter from the edge of the pipe to a larger one, under the thread at the ends of the beam (Fig. 3-4).

[0058] In the embodiment, cylindrical elements are made at the ends of beam 3 in front of the sections for threading (Fig. 5-6).

[0059] In the embodiment, the ends of beam 3 are provided with multidirectional threads to minimize the likelihood of self-loosening.

[0060] In the embodiment, the thickening of the inner wall at the transition 2 and end 3 sections is made with a smooth change in the inner diameter of the pipe, while when moving from the central part 1 to one of the ends of the beam 3, the inner diameter of the pipe first decreases, then increases.

[0061] In the embodiment, bearing seats are made on the journals.

[0062] In the embodiment, the trunnions at the ends of the beam and the transition elements are arranged symmetrically relative to the vertical axis of symmetry of the beam.

[0063] In the embodiment, the journals and transition elements 2 are made of hot-deformed steel.

[0064] In the embodiment, the beam can be made of 18KhGT steel and other grades with a yield strength of σ 0,2 = 785…1275 N / mm 2, tensile strength σ в = 835…1200 N / mm 2 .

[0065] In an embodiment, in order to avoid stress concentrators, the transitions from one diameter to another between the transition 2 and end 3 elements can be made radial (without corners) (Fig. 7).

[0066] In the embodiment, the beam may have the following dimensions: L - 1890-2615 mm (with a wall thickness of 11 mm to 32 mm), thread D1 (in the range from M72 to M100), D (in the range from 146 to 160 mm), D3 (in the range from 95 to 124 mm).

[0067] The device operates as follows.

[0068] The semitrailer suspension beam is manufactured from tubular blanks using hot-swaging at the ends, followed by machining of the seating surfaces and threads. As the semitrailer moves, the beam, through the trunnions at the ends, absorbs vertical, longitudinal, and lateral loads transmitted from the wheels through the hub assemblies. The beam functions as an elastic rod of variable cross-section, subject to bending and torsion along its entire length. The central section bears the primary bending loads arising from the weight of the vehicle and the cargo being transported.

[0069] When wheels hit road imperfections, alternating dynamic loads occur, causing cyclic deformations of the beam. Transition sections provide a connection between the central section and the end zones. Thickening the inner wall in the transition and end sections alters the stress distribution in these zones. As the tube moves from the central section to the end, the inner diameter first increases and then decreases, accompanied by a corresponding change in wall thickness.

[0070] The end sections with journals transferred forces from the wheel bearing assemblies to the beam. The stepped shape of the journals with bearing seats and threaded sections ensures the rotation of the hub components. Through rolling bearings, radial and axial forces are transferred to the journals, which absorb these loads through their outer surfaces.

[0071] During torsional stresses caused by opposite vertical wheel movements (for example, during turns or diagonal collisions with obstacles), the hollow tubular cross-section with a closed contour resists torsional moments. Stepped transitions of the outer diameters and radial joints between sections ensure a smooth change in stiffness along the beam's length.

[0072] The stated technical result: increased reliability of the axle beam for semi-trailers, achieved by the semi-trailer suspension beam being a solid, hollow element of tubular cross-section, the structure of which consists of a central, transition, and end sections with trunnions at the ends. This technical result is achieved by selecting all dimensional and geometric parameters of the beam within strictly defined, interconnected ranges, the combined observance of which ensures optimal distribution of rigidity, strength, and metal content along the length of the product.

[0073] The ratio of the central section length to the overall beam length, ranging from 0.7 to 0.83, determines the length of the zone with the maximum cross-section. Combined with a ratio of the end section length to the length of the transition and end sections combined, ranging from 0.65 to 0.9, this ensures a smooth transition in load-bearing capacity from the central section to the end zones. These length ratios create a beam geometry in which the length of the zones with variable cross-section is sufficient to redistribute loads between the central and end sections without creating abrupt changes in stiffness.

[0074] At the same time, the ratio of the inner diameter of the central section pipe to its outer diameter, ranging from 0.6 to 0.87, determines the wall thickness in the most heavily loaded central zone. This range of values ​​ensures the required load-bearing capacity of the hollow section while maintaining acceptable metal consumption. The specified wall thickness of the central section, in conjunction with the length of this section, sets the baseline flexural rigidity of the entire beam.

[0075] The ratio of the minimum outer diameter of the end section to the maximum outer diameter of the end section, ranging from 0.73 to 0.96, characterizes the degree of compression of the journals at the beam ends. This parameter, in combination with the aforementioned length ratios and the ratio of the diameters of the central section, determines the nature of the change in the outer diameter and wall thickness along the entire length of the beam. Moreover, the thickening of the inner wall at the transition sections from the central section to the journals, as well as at the end sections, achieved as a result of the selected ratios of the outer and inner diameters, provides reinforcement of the most stressed areas of the cross-sectional mating.

[0076] Thus, it is precisely the comprehensive adherence to all the stated geometric parameter ratios—section lengths, the internal and external diameters of the central section, and the minimum and maximum external diameters of the end sections—that enables the production of a beam whose central section has sufficient load-bearing capacity, whose transition zones ensure a smooth cross-sectional change, and whose end sections with trunnions possess the necessary strength with a minimum overall structural weight. The interrelationship of these structural elements within the specified numerical ranges ensures the achievement of the technical result as a unified whole, not reducible to the action of any single parameter in isolation.

[0077] The specified ranges of geometric parameters of the product were obtained on the basis of analytical models and confirmed by the results of simulation modeling and full-scale experiments.

[0078] Justification of the value ranges used:

[0079] L1 / L=0.7…0.83: The length of the compressed section relative to the overall beam length. The lower limit (0.7) is determined by the minimum length required to accommodate the bearing seats and suspension arms. The upper limit (0.83) is limited by the fact that excessively increasing the uncompressed zone leads to an unjustified increase in the beam's weight without increasing its load-bearing capacity, and also increases energy costs for heating and compressing.

[0080] D3 / D=0.6…0.87: the ratio of the inner to outer diameter of the pipe. This range is determined by the required wall thickness in the central part of the beam. The lower limit (0.6) corresponds to the maximum permissible wall thickness at which the technological possibility of crimping without loss of stability is still preserved. The upper limit (0.87) is limited by the minimum wall thickness ensuring strength under a given load;

[0081] D1 / D2=0.73…0.96: The ratio of the minimum to maximum journal diameter (the journal taper ratio). Values ​​less than 0.73 create stress concentration zones due to the sharp diameter difference. Values ​​greater than 0.96 result in insufficient taper, preventing the required bearing seat diameter from being achieved without increasing the journal outside diameter, which increases the metal consumption.

[0082] L3 / L2 = 0.65…0.9: the ratio of the end section length to the total length of the transition and end sections. This range determines the distribution of length between the mating zone (transition section) and the end section with the journal (end section). The lower limit (0.65) is determined by the need to ensure sufficient end section length to accommodate the seating surfaces for the bearings and the threaded section for the hub nut, as well as to withstand the loads transmitted through the hub assembly. When the end section length decreases below the specified value, the bearing surface of the journal is reduced, which reduces the service life of the bearing assembly. The upper limit (0.9) is limited by the fact that an increase in the share of the end section leads to a reduction in the length of the transition zone, through which a smooth change in the cross-section from the central part to the journal occurs.Excessive increases in this ratio reduce the effectiveness of stress redistribution between the central and end sections, and also increase the metal consumption of the beam ends without increasing their load-bearing capacity, since the main load from the semitrailer's mass is supported by the central zone. The selected range ensures an optimal balance between the end section length required for installing the wheel assemblies and the length of the transition zone, sufficient for a smooth change in stiffness along the beam's length.

[0083] Justification of the possibility of achieving the technical result in particular implementation cases.

[0084] 1. The all-metal hollow design eliminates welds and joints, which are the initiation sites for fatigue cracks under cyclic loads on semi-trailers. The monolithic design ensures continuous force transfer from the trunnions to the central section without weakening in the connecting areas. A single material throughout the entire length guarantees uniform elastic properties at any cross-section under dynamic loads under real road conditions.

[0085] 2. The stepped change in the outer diameter at the transition section creates distinct zones of varying load-bearing capacity, simplifying the positioning and securing of mating suspension components during installation. This design ensures more precise adherence to design dimensions during machining compared to smooth conical transitions, which is especially important for the serial production of beams with specified seat diameters. The stepped geometry helps concentrate material in areas of maximum bending moments, which occur in the transition region when a fully loaded semitrailer is operating on uneven roads.

[0086] 3. Stepped transitions from a smaller outer diameter at the end of the tube to a larger one at the beam ends ensure a clear separation between the threaded portion for the hub nut and the bearing seat, allowing each section to be formed with the required precision during machining. This design eliminates the need for welding or installing additional bushings to transition from the threaded diameter to the bearing diameter, which is especially important for semi-trailers with high axle loads, where the reliability of the hub assembly is critical.

[0087] 4. The smooth change in the inner wall thickness, with an initial increase and then a decrease from the center to the end, creates a situation in which the metal in the transition zone from the central section to the journal is redistributed such that the maximum thickness occurs in the area of ​​greatest bending stress. This internal cavity geometry allows the outer bearing seat diameters and threads at the end sections to be maintained without increasing the overall journal outer dimensions, which is important for standardizing the hub assemblies of various semitrailer models. Under dynamic loading conditions when driving with a load, the smooth profile of the inner wall eliminates sharp changes in rigidity, ensuring an even distribution of deformations along the length of the transition and end zones, increasing the beam's service life under cyclic alternating loads.

[0088] 5. Bearing seats located directly on the journals ensure high-precision alignment of the bearing inner races, eliminating the need for additional adapter sleeves or mounting rings. This design reduces the number of mating parts in the hub assembly, improving connection reliability and reducing the labor intensity of semitrailer assembly. In operating conditions with frequent wheel changes and bearing assembly maintenance (typical for heavy-duty semitrailers), the bearing seats ensure consistent bearing clearances and preload, regardless of beam heating during long hauls.

[0089] 6. The symmetrical arrangement of the trunnions and transition elements relative to the vertical beam axis ensures identical elastic and strength characteristics for the left and right sides of the suspension, eliminating differences in wheel behavior when cornering and driving over uneven road surfaces. For semi-trailers operating with frequent lane changes and maneuvers on high-speed highways, this solution guarantees equal service life for the bearing assemblies and even tire wear on both sides of the axle.

[0090] 7. Hot-formed steel provides a fine-grained structure for the trunnions and transition elements, increasing resistance to fatigue failure under cyclic bending loads that occur in these areas during semitrailer operation. This design maintains high strength characteristics in areas with the highest stress concentrations, especially during sudden temperature changes during winter operation.

[0091] 8. Steel grade 18KhGT ensures wear resistance of bearing seats and threaded sections of journals under conditions of abrasive wear from contact with dirt and sand when operating semi-trailers off-road.

[0092] 9. The radiused transitions between diameters at the junction of the transition and end sections eliminate sharp edges and abrupt cross-sectional changes, which act as stress concentrators during bending and torsional deformations that occur during the movement of a loaded semitrailer. This geometry ensures a smooth flow of force from the central section to the journal, reducing peak stresses in the diameter junction area, which is especially important for semitrailers operating on frequently uneven roads and with significant dynamic suspension loads.

Claims

1. A beam of a semi-trailer suspension axle, made in the form of a solid hollow element of tubular cross-section, includes a central section, on the sides of which transition sections are located, on the sides of which end sections are located, at the ends of the beam on the end sections there are trunnions, on the transition sections, in the transition zone from the central section to the trunnions, as well as on the end sections, the inner wall of the beam has a thickening, characterized in that the ratio of the length of the central section to the total length of the beam is from 0.7 to 0.83; the ratio of the length of the end section to the length of the transition and end sections together is from 0.65 to 0.9; the ratio of the internal diameter of the pipe of the central section to the external one is from 0.6 to 0.87; the ratio of the minimum external diameter of the end section to the maximum external diameter of the end section is from 0.73 to 0.

96.

2. A beam according to paragraph 1, characterized in that it is made in the form of a solid metal hollow element.

3. A beam according to item 1, characterized in that the transition section is made with a stepped change in the outer diameter of the pipe.

4. A beam according to paragraph 1, characterized in that at the ends of the beam there are stepped transitions from a smaller outer diameter at the edge of the pipe to a larger one.

5. A beam according to paragraph 1, characterized in that the thickening of the inner wall at the transition and end sections is made with a smooth change in the inner diameter of the pipe, while when moving from the central part to one of the ends of the beam, the inner diameter of the pipe first decreases, then increases.

6. A beam according to paragraph 1, characterized in that the journals are provided with bearing seats.

7. A beam according to claim 1, characterized in that the journals at the ends of the beam and the transition elements are located symmetrically relative to the vertical axis of symmetry of the beam.

8. A beam according to paragraph 1, characterized in that the journals and transition elements are made of hot-deformed steel.

9. A beam according to paragraph 1, characterized in that it is made of grade 18KhGT steel.

10. A beam according to paragraph 1, characterized in that the transitions from one diameter to another between the transition and end elements are made radial.

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