A variable cross-section hollow half shaft for a heavy truck suspension, its manufacturing process, and a heavy truck suspension structure

Abstract

The present invention relates to a variable cross-section hollow half shaft for a heavy truck suspension, which comprises a shaft body with a hollow structure. There is a through hole running through both ends of the shaft body. The shaft body includes a non-load-bearing section connected to an automotive bracket and a load-bearing section connected to an automotive wheel hub. The through hole sequentially includes a first section, a first transition section, and a second section. The inner diameter of the first section is larger than that of the second section. The first transition section is in the shape of a tapered hole and connects the first section and the second section at both ends. The first section is completely built into the non-load-bearing section, and the junction of the non-load-bearing section and the load-bearing section is arranged corresponding to the second section. Among them, the safety factor at the junction of the non-load-bearing section and the load-bearing section is >2. It has a smaller hole diameter at the position where the stress of the half shaft is the largest, and thus has sufficient wall thickness and strength. At the same time, it has a larger hole diameter in the non-load-bearing section, achieving a better weight reduction effect on the basis of meeting the strength. The present application also provides a manufacturing process for the variable cross-section hollow half shaft of the heavy truck suspension and a heavy truck suspension structure.

Description

Technical Field

[0001] The present invention relates to a suspension assembly of a heavy truck chassis system, and more particularly to a variable cross-section hollow half shaft for a heavy truck suspension, a manufacturing process thereof, and a heavy truck suspension structure. Background Art

[0002] The lightweighting of automobiles means that, on the premise of ensuring the strength and safety performance of automobiles, the overall vehicle mass of automobiles is reduced as much as possible, so as to improve the power performance of automobiles, reduce fuel consumption, and reduce exhaust pollution. Data shows that if the overall vehicle weight of an automobile is reduced by 10%, the fuel efficiency can be increased by 6% - 8%; for every 100 kg reduction in the overall vehicle mass of an automobile, the fuel consumption per 100 km can be reduced by 0.3 - 0.6 liters; due to the needs of environmental protection and energy conservation, the use of new materials, new structures, and new processes for lightweight components has become the trend of the development of the world's automobiles.

[0003] At present, the half shafts in heavy truck suspensions adopt a solid structure. The assembly process is to press the half shaft into the mounting plate holes of the vehicle bracket. The overhanging part of the half shaft installs the wheel hub, and the leaf spring is installed on the wheel hub, and the half shaft bears the load during actual service.

[0004] In order to reduce the weight of the half shaft, generally, the half shaft is processed by hollow lightweighting. However, the following problems need to be solved when adopting the hollow lightweight structure:

[0005] 1. Strength calculation, establishing a finite element model, and analyzing from three boundary conditions of vertical working conditions, turning working conditions, and braking working conditions to meet the load-bearing requirements;

[0006] 2. The bench loading test meets the load-bearing requirements;

[0007] 3. Solve the materials, manufacturing process, and cost of the hollow half shaft.

[0008] In the prior art, the hollow half shafts generally have the following three forms:

[0009] 1. Using large-wall-thickness pipes, which need to be ordered separately in actual production. Due to the influence of end face screw holes, the maximum inner diameter of the pipe reaches φ50mm, and the weight reduction effect is not significant, and even the cost is much higher than that of solid bars; 2. Using welding of solid and pipes such as friction welding. It is found in actual production that the use of the welding method requires additional welding equipment, with high sharing and high cost; 3. Using hollow forgings. Since there are already mature hollow forging manufacturing processes on the market, such as hollow forging of axle tubes, the inner hole forging of the half shaft can be realized, and the weight reduction and cost reduction are significant. However, there is currently no hollow half shaft with both strength and safety performance meeting the usage requirements, and research and development are urgently needed. Summary of the Invention

[0010] Based on the above description, the present invention is provided to solve the technical problems of unreasonable structural design of hollow half shafts in the prior art, resulting in high weight reduction or high cost.

[0011] The technical solution of the present invention to solve the above technical problems is as follows:

[0012] A variable cross-section hollow half shaft for a heavy truck suspension, which includes a shaft body with a hollow structure. There is a through hole running through both ends inside the shaft body. The shaft body includes a non-load-bearing section connected to the vehicle bracket and a load-bearing section connected to the vehicle wheel hub. The through hole successively includes a first section, a first transition section, and a second section. The inner diameter of the first section is larger than that of the second section. The first transition section is in the shape of a tapered hole and connects the first section and the second section at both ends. The first section is completely built inside the non-load-bearing section. The junction of the non-load-bearing section and the load-bearing section is arranged corresponding to the second section. Among them, the safety factor at the junction of the non-load-bearing section and the load-bearing section > 2.

[0013] Compared with the prior art, the technical solution of the present application has the following beneficial technical effects:

[0014] For the variable cross-section hollow half shaft for a heavy truck suspension provided by the present application, since the inner diameter of the first section is larger than that of the second section, and the first section is completely built inside the non-load-bearing section, the junction of the non-load-bearing section and the load-bearing section is arranged corresponding to the second section, and the safety factor at the junction of the non-load-bearing section and the load-bearing section > 2, it has a smaller hole diameter at the position where the stress of the half shaft is the largest, that is, at the junction of the non-load-bearing section and the load-bearing section, and thus has sufficient wall thickness and strength. At the same time, in the non-load-bearing section, it has a larger hole diameter, achieving a better weight reduction effect on the basis of meeting the strength requirements.

[0015] Based on the above technical solution, the present invention can be further improved as follows.

[0016] Further, the through hole further includes a second transition section and a threaded hole section. The threaded hole section is completely built inside the load-bearing section and the inner diameter is smaller than that of the second section. The second transition section is in the shape of a tapered hole and connects the second section and the threaded hole section at both ends.

[0017] Further, a number of flange connection holes are formed on the end face of the load-bearing section.

[0018] The present application also provides a manufacturing process for a variable cross-section hollow half shaft for a heavy truck suspension. First, forge the blank of the hollow variable cross-section half shaft, then machine the blank by turning. After quenching and tempering treatment, finish turning the blank, then drill threaded holes on the end face of the load-bearing section, and then perform surface induction hardening on the workpiece. After flaw detection, grind the outer circle structure to form.

[0019] The present application also provides a heavy truck suspension structure, which is characterized in that it includes a suspension main body, a vehicle bracket, a wheel hub, and the above-mentioned variable cross-section hollow half shaft for a heavy truck suspension;

[0020] The vehicle bracket is installed on both sides of the suspension body. The wheel hub is correspondingly connected to the outside of the vehicle bracket through the half shaft. The vehicle bracket is correspondingly connected to the non-load-bearing section of the shaft body, and the wheel hub is correspondingly connected to the load-bearing section of the shaft body. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 FIG. 1 is a schematic structural diagram of a variable cross-section hollow half shaft of a heavy truck suspension provided in Embodiment 1 of the present invention;

[0022] Figure 2 FIG. 2 is a schematic structural diagram of a heavy truck suspension structure provided in Embodiment 2 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. Embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present application is thorough and comprehensive.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of the present application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0025] It can be understood that spatial relationship terms such as "under", "below", "lower", "beneath", "above", "upper", etc. can be used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that in addition to the orientation shown in the figure, spatial relationship terms also include different orientations of the devices during use and operation. For example, if the device in the figure is flipped, the element or feature described as "under other elements" or "beneath it" or "under it" will be oriented "above" other elements or features. Therefore, the exemplary terms "under" and "beneath" can include both the upper and lower orientations. In addition, the device can also include other orientations (such as rotating 90° or other orientations), and the spatial description language used herein is accordingly interpreted.

[0026] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediate element. In the following embodiments, "connection", if there is an electrical signal or data transmission between the connected circuits, modules, units, etc., should be understood as "electrical connection", "communication connection", etc.

[0027] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising", "including" or "having", etc. specify the presence of the stated features, integers, steps, operations, components, parts or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts or combinations thereof.

[0028] Embodiment 1

[0029] As Figure 1 shown, Embodiment 1 of the present application provides a variable cross-section hollow half shaft for a heavy truck suspension. The hollow half shaft includes a shaft body 1 with a hollow structure. A through hole 1a runs through both ends of the shaft body 1. The shaft body 1 includes a non-load-bearing section 11 connected to the vehicle bracket and a load-bearing section 12 connected to the vehicle wheel hub.

[0030] Wherein, the through hole 1a successively includes a first section a1, a first transition section a12 and a second section a2. The inner diameter of the first section a1 is larger than that of the second section a2. The first transition section a12 is in the shape of a tapered hole and connects the first section a1 and the second section a2 at both ends, thus forming a variable cross-section hollow structure.

[0031] Since the aperture of the first section a1 is larger, it is completely placed inside the non-load-bearing section. On the basis of meeting the strength requirements, more weight reduction design can be carried out, thereby reducing the self-weight of the half shaft.

[0032] The junction of the non-load-bearing section 11 and the load-bearing section 12 corresponds to the junction of the vehicle bracket and the wheel hub. Due to the force on the wheel hub, the stress of the half shaft is most concentrated at this junction. Therefore, the second section a2 with a smaller aperture is arranged at this junction. Among them, to ensure the strength and meet the vertical bending working condition under extreme conditions, through finite element boundary analysis, the up and down forces reach 36 tons, and the safety factor at the junction of the non-load-bearing section and the load-bearing section > 2.

[0033] More preferably, in this embodiment, the through hole 1a further includes a second transition section a23 and a threaded hole section a3. The threaded hole section a3 is completely placed inside the load-bearing section 12 and the inner diameter size is smaller than that of the second section 12. The second transition section a23 is in the shape of a tapered hole and connects the second section a2 and the threaded hole section a3 at both ends. The first transition section a12 and the second transition section a23 can ensure the smooth change of the cross-sectional size inside the through hole 1a, reduce the internal stress concentration points, and prevent excessive internal stress.

[0034] Wherein, a plurality of flange connection holes 12a are formed on the end face of the load-bearing section 12 for connecting flanges or other wheel hub components.

[0035] The hollow half shaft provided by this embodiment can be processed by the following manufacturing process:

[0036] First, use the die forging process to machine the blank of the hollow variable cross-section half shaft, then rough turn the blank, subject the machined blank to quenching and tempering treatment and then perform finish turning. Next, drill threaded holes at the end face of the load-bearing section, and finally perform surface induction hardening on the workpiece. After passing the internal flaw detection, grinding the outer circle structure can complete the shaping.

[0037] The hollow half shaft provided by this embodiment has a smaller hole diameter at the position where the half shaft stress is the largest, and thus has sufficient wall thickness and strength. At the same time, it has a larger hole diameter in the non-load-bearing section, achieving a better weight reduction effect on the basis of meeting the strength requirements.

[0038] During the actual vehicle assembly and use, it is measured that the weight reduction of the compared solid half shaft is about 6 Kg, and the weight reduction of the whole vehicle is about 12 Kg. Comprehensive comparison shows that the cost of each hollow half shaft is reduced by about 35 yuan compared with the solid half shaft. While effectively reducing the weight, the cost is reduced, creating huge economic benefits for the automobile manufacturing plant.

[0039] Embodiment Two

[0040] The embodiment of the present application provides a structural design for assembling and using the above-mentioned hollow half shaft, that is, a heavy truck suspension structure, which includes a suspension main body 10, a vehicle bracket 20, a wheel hub 30, and the above-mentioned variable cross-section hollow half shaft 40 of the heavy truck suspension.

[0041] Among them, the vehicle bracket 20 is installed on both sides of the suspension main body 10. The non-load-bearing section of the shaft body of the hollow half shaft 40 is pressed into the installation hole of the vehicle bracket 20, and the load-bearing section of the hollow half shaft 40 extends outside the vehicle bracket 20. The wheel hub 30 is installed on the load-bearing section of the hollow half shaft 40.

[0042] After the installation is completed, test the suspension structure according to the test standard. If there is no damage when the preset pressure is loaded to the preset number of times, it indicates that it is qualified. For example, in the middle of a specific suspension structure for a heavy truck chassis, load a load pressure of +4T to +36T at the leaf spring seat of the wheel hub, and it is required that there is no damage after 600,000 times.

[0043] The above suspension structure adopts the above-mentioned structural design of the variable cross-section hollow half shaft of the heavy truck suspension, realizing the lightweight of the automobile suspension structure while ensuring the structural strength of the suspension structure, and saving the manufacturing cost.

[0044] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A variable cross-section hollow half shaft for a heavy truck suspension, characterized in that, It includes a shaft body with a hollow structure. There is a through hole running through both ends inside the shaft body. The shaft body includes a non-load-bearing section connected to an automotive bracket and a load-bearing section connected to an automotive wheel hub. The through hole sequentially includes a first section, a first transition section, and a second section. The inner diameter of the first section is larger than that of the second section. The first transition section is in the shape of a tapered hole and connects the first section and the second section at both ends. The first section is completely built inside the non-load-bearing section. The junction of the non-load-bearing section and the load-bearing section is arranged corresponding to the second section. The through hole also includes a second transition section and a threaded hole section. The threaded hole section is completely built inside the load-bearing section and the inner diameter is smaller than that of the second section. The second transition section is in the shape of a tapered hole and connects the second section and the threaded hole section at both ends. Among them, the safety factor at the junction of the non-load-bearing section and the load-bearing section > 2.

2. The variable cross-section hollow half shaft of the heavy truck suspension according to claim 1, characterized in that A number of flange connection holes are formed on the end face of the load-bearing section.

3. A manufacturing process of the variable cross-section hollow half shaft for a heavy truck suspension as claimed in claims 1-2, which comprises the following steps: First, forge the blank of the hollow variable cross-section half shaft by die forging, then machine the blank by turning. After quenching and tempering treatment, finish turning the blank. Then drill threaded holes on the end face of the load-bearing section. Then perform surface induction hardening on the workpiece. After flaw detection, grind the outer circular structure to form.

4. A heavy truck suspension structure, characterized in that, It includes a suspension main body, an automotive bracket, a wheel hub, and the variable cross-section hollow half shaft for a heavy truck suspension as claimed in claims 1-2; The automotive bracket is installed on both sides of the suspension main body. The wheel hub is correspondingly connected to the outside of the automotive bracket through the half shaft. The automotive bracket is correspondingly connected to the non-load-bearing section of the shaft body. The wheel hub is correspondingly connected to the load-bearing section of the shaft body.

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