A type selection and checking method of the main bearing cap bolts of an automobile engine

A technology for automobile engines and main bearing caps, applied in computer-aided design, instrumentation, geometric CAD, etc., can solve the problems of safety risks of main bearing cap bolts and insufficient design methods of main bearing cap bolts

Active Publication Date: 2022-04-15
DONGFENG MOTOR CORP HUBEI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The invention provides a type selection and checking method for main bearing cap bolts of an automobile engine, which is used to solve the technical problem that the design method of the main bearing cap bolts in the prior art is not perfect enough to cause safety risks in the use of the main bearing cap bolts

Method used

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  • A type selection and checking method of the main bearing cap bolts of an automobile engine
  • A type selection and checking method of the main bearing cap bolts of an automobile engine
  • A type selection and checking method of the main bearing cap bolts of an automobile engine

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Effect test

Embodiment 1

[0047] This embodiment provides a type selection and verification method for the main bearing cap bolts of an automobile engine, which is used to solve the technical problem that the existing technology is not perfect in the type selection method for the main bearing cap bolts of the engine, which leads to safety risks during use. Specifically, in the existing design methods for the bolts of the main bearing cap of the engine, the actual conditions such as the friction coefficient dispersion, yield strength dispersion, specifications and dimensions of the bolts are not considered, and most of the bolts of different specifications are selected according to different specifications. The selection is made by trial and error. Due to the above reasons, the pretightening force of the selected bolts may not meet the requirements, and the selection and verification process is complicated and error-prone, so that the selected bolts have a greater safety risk when used.

[0048] Such as ...

Embodiment approach

[0068] The present embodiment is as a kind of exemplary embodiment of embodiment 1, as follows:

[0069] Step 1.1: The maximum engine burst pressure P is known max 98.5MPa, cylinder block 6 cylinder hole diameter d g is 82mm, calculate the maximum working load F of the engine by formula 1 g =52.02kN.

[0070] Step 1.2: Calculate the maximum dynamic load F of the bearing shell on the main bearing cap 2 by formula 2 b = 34.85kN.

[0071] Step 1.3: Know the bearing thickness t bs is 1.8mm, the main bearing pad width w bs is 21.2mm, the allowable contact stress σ of the bearing material bs is 351MPa, calculate the pretightening force F required to prevent the bearing bush from being opened by formula 3 V = 26.79kN.

[0072] Step 1.4: Calculate the pretightening force F to be provided by a single bolt 1 on the main bearing cap 2 through formula 4 n = 30.82 kN.

[0073] Step 1.5: The main bearing cap 2 is ductile iron, the flatness of the bearing surface is required to be ...

Embodiment 3

[0079] This embodiment is used as a practical embodiment of the present invention. In this embodiment, the calculation function of the EXCEL form is used to execute the method in the above-mentioned embodiment, that is, to input formula 1 to formula 9 into the EXCEL form and associate them. When a corresponding input value is input, a corresponding output value is obtained, so that the accuracy and efficiency of the calculation of the above method can be improved.

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Abstract

The invention relates to a method for selecting and checking bolts of a main bearing cap of an automobile engine, and belongs to the technical field of vehicle manufacturing. The method provided by this application obtains the maximum working load of the engine and further obtains the maximum dynamic load of the bearing pad of the main bearing cap through the maximum explosion pressure of the engine, and considers the preload force required to prevent the main bearing pad from opening under static assembly conditions, According to the predetermined safety factor determined by the attenuation of the axial force, it is simplified to the pretightening force provided by a single bolt to fasten the bearing pad, and then the bolt is positively selected, and then the bolt is in the state of mass production. According to the specification and size, friction coefficient dispersion, yield strength dispersion and the actual situation, the actual maximum pre-tightening force and the actual minimum pre-tightening force of the bolts are calculated accurately, and finally checked. The method can accurately select the bolts of the main bearing cap of the automobile engine. The method is simple and well considered, and the selected bolts are more in line with the actual situation of the operation of the automobile engine.

Description

technical field [0001] The invention belongs to the technical field of vehicle manufacturing, in particular to a method for selecting and checking bolts of a main bearing cover of an automobile engine. Background technique [0002] The main bearing cap bolts are mainly used for the fastening connection between the engine block, crankshaft, main bearing shell and main bearing cap. By tightening, the main bearing cap will generate uniform and appropriate axial preload, and the crankshaft will be tightened on the cylinder block. Support and positioning. During the operation of the engine, the main bearing cap bolts are fastened so that the main bearing cap is not easy to loosen; and a proper and uniform lubricating oil film gap is formed between the main bearing hole and the diameter of the crankshaft main bearing to ensure the crankshaft is reliable when it runs at high speed. and durability. The bolts of the main bearing cap shall have sufficient rigidity and fatigue streng...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G06F30/17G06F30/15G06F111/10G06F119/14G06F119/18
CPCG06F30/17G06F30/15G06F2119/14G06F2119/18G06F2111/10
Inventor 张继杨唐元媛黄洪浪王静秋徐天添
Owner DONGFENG MOTOR CORP HUBEI
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