CN108168497B

CN108168497B - Method for measuring timing angle of engine

Info

Publication number: CN108168497B
Application number: CN201711458929.9A
Authority: CN
Inventors: 程敏; 张宝秀; 何一太; 邱鹏; 杨新月; 陈建伟
Original assignee: Jiangxi Tengle Power Co Ltd
Current assignee: Jiangxi Tengle Power Co Ltd
Priority date: 2017-12-28
Filing date: 2017-12-28
Publication date: 2019-12-13
Anticipated expiration: 2037-12-28
Also published as: CN108168497A

Abstract

a measuring method of an engine timing angle belongs to the technical field of automobile engine assembly, and comprises the steps of selecting a cylinder cover as a reference surface A, selecting a plane where a camshaft signal wheel is located as a detection surface B1, and selecting a crankshaft end face as a detection surface B2; measuring an included angle a between a connecting line of an identification point of an camshaft signal wheel on the detection surface B1 and a central line of a camshaft and the reference surface A, and measuring an included angle B between a connecting line of a positioning pin on a crankshaft and the central line of the crankshaft and the reference surface A; compare a with i₁/i₂B, judging the correctness of the timing angle, wherein the measuring method takes the surface of the cylinder cover as a reference surface, and compares the sizes of the included angles between the mark connecting lines on the camshaft and the crankshaft and the reference surface and the installation theoretical value through the relation between the measured mark connecting lines on the three-coordinate measuring instrument and the reference surface, so that the checking is more convenient and can be finished without starting an engine.

Description

Method for measuring timing angle of engine

Technical Field

The invention relates to the technical field of automobile engine assembly, in particular to a method for measuring a timing angle of an engine.

background

The timing driving system is the heart of the engine and ensures correct opening time of the intake valve and the exhaust valve, thereby controlling good combustion state and strong performance output of the engine. The timing driving system is a linkage system, an engine is usually designed by taking the top dead center of a piston as a reference and arranging an intake mechanical installation angle and an exhaust mechanical installation angle, but since a camshaft and a crankshaft related to the timing angle are both arranged in a cylinder head and a cylinder block, a method for directly measuring the timing driving system is unavailable. When the performance of the engine deviates, the analysis is checked according to whether the timing angle is correct, so that the measurement is troublesome, and the problem of the engine is very disadvantageously checked.

Disclosure of Invention

in order to solve the technical problems, the invention provides a method for measuring the timing angle of an engine, which mainly solves the problem that the timing angle of the engine is difficult to measure after the engine is operated, so that the troubleshooting analysis is difficult.

In order to achieve the purpose, the technical scheme adopted by the invention for solving the technical problems is as follows: the method for measuring the timing angle of the engine is characterized by comprising the following steps of:

1) selecting a cylinder cover as a reference surface A, and selecting a plane where a camshaft signal wheel is located as a detection surface B₁selecting the end face of the crankshaft end as a detection face B₂；

2) Measuring the test surface B₁Measuring the included angle a between the connecting line of the mark point of the upper camshaft signal wheel and the central line of the camshaft and the reference surface A, and measuring the detection surface B₂An included angle b between a connecting line of the upper positioning pin and the central line of the crankshaft and the reference surface A;

3) According to the transmission ratio i of camshaft to crankshaft₁:i₂Comparing a with i₁/i₂B to determine the correctness of the timing angle.

Further, the identification point of the camshaft signal wheel is arranged on one of the gear teeth of the camshaft signal wheel.

further, the method for judging the correctness of the timing angle in the step 3) is as follows: if a-i₁/i₂·b>Theoretical value, the timing angle is larger; if a-i₁/i₂·b<the timing angle is smaller according to a theoretical value; a-i₁/i₂B is a theoretical value, the timing angle meets the installation requirement.

Further, the measuring tool used for measuring the included angle a and the included angle b in the step 2) is a three-coordinate measuring instrument.

Further, the step of measuring the included angle a and the included angle b by the three-coordinate measuring instrument is as follows:

1) Placing the engine on a workbench of a three-coordinate measuring instrument, enabling a reference surface A to be vertical to the workbench, and controlling a telescopic measuring head to measure three-dimensional coordinate values of an identification point of a camshaft signal wheel and a positioning pin on a crankshaft relative to the reference surface A respectively;

2) And the microcomputer analyzes and processes the three-dimensional coordinate values and calculates the values of the included angle a and the included angle b.

The invention has the beneficial effects that:

The measuring method takes the surface of the cylinder cover as a datum plane, the three-coordinate measuring instrument is used for measuring the included angles between the mark connecting lines on the camshaft and the crankshaft and the datum plane respectively, and whether the checking right angle is correct or not is judged through comparison between the size of the two included angles and the relation between the mounting theoretical values.

Drawings

The contents of the expressions in the various figures of the present specification and the labels in the figures are briefly described as follows:

FIG. 1 is a schematic mechanical diagram of an engine;

FIG. 2 is a schematic diagram of the measurement principle of the present invention;

The labels in the above figures are: 1. the cylinder cover, 2, camshaft signal wheel, 3, bent axle, 4 locating pin.

Detailed Description

the following description of preferred embodiments of the invention will be made in further detail with reference to the accompanying drawings.

The specific implementation scheme of the invention is as follows: as shown in fig. 1 and fig. 2, a method for measuring an engine timing angle includes the following steps:

1) Selecting a cylinder cover 1 as a reference surface A and selecting a plane where a camshaft signal wheel 2 is located as a detection surface B₁Selecting the end face of the shaft end of the crankshaft 3 as a detection face B₂；

2) Measuring the test surface B₁Connecting line and reference surface of identification point of upper camshaft signal wheel 2 and camshaft central lineAn included angle a between A, and an included angle b between a connecting line of a positioning pin 4 on the crankshaft 3 and a central line of the crankshaft 3 and a reference plane A; in order to measure the size of the included angle a conveniently, the identification point of the camshaft signal wheel 2 is arranged on one gear tooth of the camshaft signal wheel 2; in order to make the measurement more accurate, the measuring tool used for measuring the included angle a and the included angle b is a three-coordinate measuring instrument, and the specific steps are as follows: the engine is placed on a workbench of a three-coordinate measuring instrument, a reference surface A is perpendicular to the workbench, the telescopic measuring head is controlled to measure three-dimensional coordinate values of the identification point of the camshaft signal wheel 2 and the positioning pin 4 on the crankshaft 3 relative to the reference surface A respectively, then a microcomputer is used for analyzing and processing the three-dimensional coordinate values, and the values of the included angle a and the included angle b are calculated.

3) According to the transmission ratio i of camshaft and crankshaft 3₁:i₂Comparing a with i₁/i₂B, judging the correctness of the timing angle, namely judging whether the timing angle is installed correctly when the engine is installed or whether a tooth jumping phenomenon occurs when the engine works, wherein the specific method comprises the following steps: if a-i₁/i₂·b>Theoretical value, the timing angle is larger; if a-i₁/i₂·b<The timing angle is smaller according to a theoretical value; a-i₁/i₂B is the theoretical value, the timing angle is in accordance with the mounting requirements.

In conclusion, the measuring method takes the surface of the cylinder cover as a reference surface, the three-coordinate measuring instrument is used for measuring the included angles between the connecting lines of the marks on the camshaft and the crankshaft and the reference surface respectively, whether the timing angle is correct or not is judged through comparison between the size of the two included angles and the relation between the mounting theoretical values, the checking is convenient and rapid, the measurement is accurate, and the engine can be started without the need of starting the engine.

While the foregoing is directed to the principles of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

1. A method for measuring the timing angle of an engine is characterized by comprising the following steps:

1) Selecting a cylinder cover (1) as a reference surface A, and selecting a plane where a camshaft signal wheel (2) is located as a detection surface B₁Selecting the end face of the shaft end of the crankshaft (3) as a detection face B₂；

2) Measuring the test surface B₁An included angle a between a connecting line of an identification point of the upper camshaft signal wheel (2) and a central line of the camshaft and the reference surface A is measured, and a detection surface B is measured₂An included angle b between a connecting line of the upper positioning pin (4) and the central line of the crankshaft (3) and the reference plane A;

3) According to the transmission ratio i of the camshaft and the crankshaft (3)₁:i₂comparing a with (i)₁/i₂) B to determine the correctness of the timing angle.

2. The timing angle measuring method according to claim 1, characterized in that: the identification point of the camshaft signal wheel (2) is arranged on one of the gear teeth of the camshaft signal wheel (2).

3. The timing angle measuring method according to claim 1, characterized in that: the method for judging the correctness of the timing angle in the step 3) comprises the following steps: if a- (i)₁/i₂)·b>theoretical value, the timing angle is larger; if a- (i)₁/i₂)·b<the timing angle is smaller according to a theoretical value; a- (i)₁/i₂) B is a theoretical value, the timing angle meets the installation requirement.

4. the timing angle measuring method according to claim 2, characterized in that: and 2) measuring the included angle a and the included angle b by using a measuring tool which is a three-coordinate measuring instrument.

5. The timing angle measuring method according to claim 4, characterized in that: the step of measuring the included angle a and the included angle b by the three-coordinate measuring instrument is as follows:

1) placing the engine on a workbench of a three-coordinate measuring instrument, enabling a datum plane A to be vertical to the workbench, and controlling a telescopic measuring head to measure three-dimensional coordinate values of an identification point of a camshaft signal wheel (2) and a positioning pin (4) on a crankshaft (3) relative to the datum plane A respectively;