CN109297399B - Timing angle measuring device, method and system - Google Patents

Abstract

Timing angle measuring device, method and system, the engine camshaft timing angle measuring device includes: rotation axis and second inclination measuring device, wherein: the first end of the rotating shaft is connected with an engine cam shaft; the second inclination angle measuring device is fixed at the second end of the rotating shaft and is used for measuring the timing angle of the engine camshaft. According to the scheme, the measurement accuracy of the engine timing angle deviation can be improved.

Description

Timing angle measuring device, method and system

Technical Field

The embodiment of the invention relates to the technical field of engines, in particular to a timing angle measuring device, a timing angle measuring method and a timing angle measuring system.

Background

The standard of the light automobile pollutant emission limit value and the measuring method (Chinese sixth stage) can be simply called as 'Guohu', and the standard of the light automobile pollutant emission limit value and the measuring method (Chinese fifth stage) can be simply called as 'Guohu'. The 'Guohu' is an upgrade to the 'Guohu' standard, and compared with the 'Guohu' standard, the 'Guohu' has more strict emission limit to automobile pollutants, the carbon monoxide emission of the gasoline car is reduced by 50 percent, the emission limit of total hydrocarbon and non-methane total hydrocarbon is reduced by 50 percent, the emission limit of nitrogen oxides is increased by 42 percent, and the method is formally implemented in stages in the next few years under the conditions of eliminating working conditions and testing influences.

Along with the increasingly strict motor vehicle emission requirements and the national policies of energy conservation and emission reduction related methods, the accurate control of timing systems by various car manufacturers is more and more strict, the assembly requirements on engine timing systems are more and more strict, and the detection precision requirements on the assembled timing positions are more and more high.

The engine timing system mainly comprises a camshaft Hall sensor for collecting position signals of an intake camshaft and an exhaust camshaft and a crankshaft position sensor for confirming a Top dead center (Top DEAD CENTER) of one cylinder of the engine. The engine timing system is mainly used for fuel injection control, ignition timing control, variable valve timing technology (Variable VALVE TIMING, VVT), and the like.

Currently, mechanical timing clamps or mechanical timing pointer angle measurement tools are commonly used to detect engine timing position.

However, the mechanical timing clamp is used for detecting the timing position of the engine, so that the accuracy is poor, and the recording timing angle deviation cannot be quantified. The mechanical timing clamp after some improvements can measure and visually read the angle deviation under the cooperation of auxiliary measuring tools, and the precision is still poor and the operation is complex. The accuracy of the engine timing angle deviation measured using the mechanical timing pointer angle measuring tool is also poor.

The timing angle deviation allowed by the engines of different models is different, and the smaller the timing angle deviation of the engine is, the better the timing angle deviation of the engine is, and particularly when the emission limit of the national standard on automobile pollutants is more strict, once the timing position of the engine is deviated or the accuracy is insufficient, the economical efficiency, the dynamic property, the comfort and the pollutant emission of the whole automobile can be influenced.

Disclosure of Invention

The invention solves the technical problem of how to improve the measurement accuracy of the engine timing angle deviation.

In order to solve the above technical problems, an embodiment of the present invention provides an engine camshaft timing angle measurement device, including: rotation axis and second inclination measuring device, wherein: the first end of the rotating shaft is connected with an engine cam shaft; the second inclination angle measuring device is fixed at the second end of the rotating shaft and is used for measuring the timing angle of the engine camshaft.

Optionally, the engine camshaft timing angle measurement device further includes: and the fixed shaft sleeve is sleeved on the rotating shaft.

Optionally, the fixed shaft sleeve is provided with a pin stop hole, and the rotating shaft is provided with a pin stop groove matched with the pin stop hole.

Optionally, the engine camshaft timing angle measurement device further includes: adjusting the rotating shaft sleeve and the adjusting arm, wherein: the adjusting rotating shaft sleeve is sleeved on the rotating shaft; the adjusting arm is detachably connected with the adjusting rotating shaft sleeve and is suitable for rotating the adjusting rotating shaft sleeve to adjust the angle of the engine cam shaft.

Optionally, the engine camshaft timing angle measurement device further includes: and the camshaft sliding support is sleeved on the rotating shaft.

Optionally, the engine camshaft is a double overhead camshaft, including: an intake camshaft and an exhaust camshaft.

Optionally, the rotating shaft includes: the first end of the air inlet cam shaft is connected with the air inlet cam shaft; and the first end of the exhaust camshaft rotating shaft is connected with the exhaust camshaft.

Optionally, the camshaft sliding support includes: intake camshaft sliding support and exhaust camshaft sliding support, wherein: the air inlet cam shaft sliding support is sleeved on the air inlet cam shaft rotating shaft and is clamped with the air outlet cam shaft sliding support; the exhaust camshaft sliding support is sleeved on the exhaust camshaft rotating shaft.

Optionally, one of the intake camshaft sliding support and the exhaust camshaft sliding support is provided with a connecting portion, and the other is provided with a receiving hole for receiving the connecting portion.

Optionally, a groove is formed at the second end of the rotating shaft, the bottom of the groove is a plane and passes through the axis of the rotating shaft, and the second inclination angle measuring device is fixed in the groove.

Optionally, the second inclination measuring device is a capacitive acceleration sensor.

The embodiment of the invention also provides an engine timing angle measuring system, which comprises: the engine camshaft timing angle measurement device of any one of the above, wherein: the engine crankshaft timing measurement apparatus includes: the rotating shaft bracket is provided with a cylinder body reference position positioning hole and a crankshaft reference position positioning hole; one end of the fixed part is fixedly connected with the engine crankshaft, and the other end of the fixed part is connected with the rotating shaft frame and can rotate relative to the rotating shaft frame; and the first inclination angle measuring device is fixed on the rotating shaft frame and is used for measuring the timing angle of the crankshaft of the engine after the upper dead center of one cylinder of the engine is determined through the cylinder body reference position locating hole and the crankshaft reference position locating hole.

Optionally, the engine crankshaft timing measurement device further includes: the cylinder body reference position adapting pin is matched with the cylinder body reference position positioning hole; and the crankshaft reference position adapting pin is matched with the crankshaft reference position positioning hole.

Optionally, the engine crankshaft timing measurement device further includes: the signal wheel positioning hole is arranged on the rotating shaft bracket.

Optionally, the signal wheel positioning hole is located between the cylinder body reference position positioning hole and the crankshaft reference position positioning hole.

Optionally, the fixing part is provided with a protrusion, and the spindle bracket is provided with a groove for accommodating the protrusion.

Optionally, the rotating shaft bracket is provided with a containing part for placing the first inclination angle measuring device.

The embodiment of the invention also provides an engine timing angle measuring method, which comprises the following steps: determining a cylinder top dead center of the engine; the absolute position of the engine camshaft is obtained by adopting the timing angle measuring device of the engine camshaft; an engine timing angle is calculated based on the obtained absolute position of the engine camshaft and the absolute position of the engine crankshaft.

Optionally, the obtaining the absolute position of the engine camshaft by using the engine camshaft timing angle measurement device includes: acquiring the engine camshaft timing offset angle from the second inclination measuring device; and obtaining the absolute position of the cam shaft according to the deviation of the engine base, the rotation angle of the cam shaft, the installation deviation of the second inclination angle measuring device and the timing deviation angle of the cam shaft of the engine.

Optionally, when the engine camshaft is a dual overhead camshaft, the acquiring the absolute position of the engine camshaft includes: a third inclination angle measuring device and a fourth inclination angle measuring device are respectively arranged on the air inlet camshaft and the air outlet camshaft, the timing deviation angle of the air inlet camshaft is obtained from the third inclination angle measuring device, and the timing deviation angle of the air outlet camshaft is obtained from the fourth inclination angle measuring device; obtaining the absolute position of the air inlet cam shaft according to the deviation of the engine base, the cam shaft rotation angle, the installation deviation of the third inclination angle measuring device and the timing deviation angle of the air inlet cam shaft; and obtaining the absolute position of the exhaust camshaft according to the deviation of the engine base, the rotation angle of the camshaft, the installation deviation of the fourth inclination angle measuring device and the timing deviation angle of the intake camshaft.

Optionally, the determining the top dead center of the engine cylinder includes: mounting an engine crankshaft timing angle measurement device to an engine crankshaft, wherein the engine crankshaft timing angle measurement device comprises: the pivot frame, fixed part, first inclination measuring device, wherein: the rotating shaft frame is provided with a cylinder body reference position positioning hole and a crankshaft reference position positioning hole; the rotating shaft frame is provided with a cylinder body reference position positioning hole and a crankshaft reference position positioning hole; one end of the fixing part is fixedly connected with the engine crankshaft, and the other end of the fixing part is connected with the rotating shaft frame and can rotate relative to the rotating shaft frame; the first inclination angle measuring device is fixed on the rotating shaft bracket and is used for measuring the timing angle of the engine crankshaft; taking an absolute horizontal line as a zero deviation position, positioning a crankshaft mechanical timing position to a reference position, rotating the rotating shaft frame to a first position, determining an engine timing reference position by adopting the cylinder body reference position positioning hole, and reading a first angle displayed by the first inclination angle measuring device; rotating the rotating shaft frame to a second position, determining a crankshaft timing reference position by adopting the crankshaft reference position positioning hole, and reading a second angle displayed by the first inclination angle measuring device; and determining the top dead center position of one cylinder of the engine according to the first angle and the second angle.

Optionally, the first inclination measuring device, the second inclination measuring device, the third inclination measuring device and the fourth inclination measuring device are all capacitive acceleration sensors.

Optionally, the obtaining the engine timing angle according to the obtained absolute position of the engine camshaft and the absolute position of the engine crankshaft includes: the engine timing angle deviation alpha is calculated by adopting the following formula: f=ma; c=epsilon·s/x; f=kx; ax= gsin α, ay= gcos α;

Wherein Ax is a measured value of acceleration in the x-axis direction, ay is a measured value of acceleration in the y-axis direction, az is a measured value of acceleration in the z-axis direction, charge between C electrodes, k is a stiffness coefficient, m is a mass of a mass block, x is displacement, F is force applied to the displacement x, G is gravitational acceleration, G is gravity, alpha is engine timing angle deviation, a is acceleration applied to a capacitive acceleration sensor, alpha _x is an included angle between Ax and gravity G, alpha _y is an included angle between Ay and gravity G, alpha _z is an included angle between Az and gravity G, epsilon is a dielectric constant of a medium between capacitive plates, and S is an area of a capacitive plate.

Optionally, the engine timing angle measurement method further comprises: and rotating the rotating shaft frame to the reference position of the signal wheel to obtain the angle deviation between the timing position of the crankshaft of the engine and the signal wheel.

Compared with the prior art, the technical scheme of the embodiment of the invention has the following beneficial effects:

The rotating shaft is connected with the engine camshaft, the timing angle of the engine camshaft can be directly measured through the second inclination angle measuring device fixed at the second end of the rotating shaft, and compared with the existing manual estimation deviation angle, the accuracy of the engine camshaft timing angle measured by the engine camshaft timing angle measuring device provided by the embodiment of the invention is higher, so that the measuring accuracy of the engine timing angle deviation can be improved.

Furthermore, the correction before the measurement is carried out on the engine crankshaft timing angle measuring device according to the cylinder body reference position locating hole and the crankshaft reference position locating hole on the rotating shaft bracket, and the first inclination angle measuring device is adopted to measure the engine crankshaft timing angle, so that the deviation of a timing system is not required to be determined by collecting signals output by a crankshaft signal wheel and camshaft signals, and manual estimation is not required, and the measuring precision of the engine timing angle deviation can be further improved.

Drawings

FIG. 1 is a schematic diagram of an engine camshaft timing angle measurement device according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of an engine camshaft timing angle measurement device according to an embodiment of the present invention;

FIG. 3 is an exploded view of an engine camshaft timing angle measurement device according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of an engine camshaft timing angle measurement device in accordance with an embodiment of the present invention in conjunction with an engine camshaft;

FIG. 5 is a schematic structural view of a camshaft timing calibration block;

FIG. 6 is a schematic diagram of an engine crankshaft timing angle measurement apparatus according to an embodiment of the present invention;

FIG. 7 is a cross-sectional view of FIG. 6 in the direction A-A;

FIG. 8 is an exploded view of an engine crankshaft timing angle measurement apparatus according to an embodiment of the present invention;

FIG. 9 is a flow chart of a method of engine timing angle measurement in an embodiment of the present invention;

FIG. 10 is a schematic diagram of camshaft timing position with intake camshaft misalignment;

FIG. 11 is a schematic diagram of camshaft timing position with exhaust camshaft misalignment;

FIG. 12 is a schematic diagram of the positional relationship of an engine crankshaft and a crankshaft timing measurement at top dead center;

fig. 13 to 16 are timing position diagrams of the engine in different states;

FIG. 17 is a schematic diagram of a capacitive acceleration sensor according to an embodiment of the present invention;

FIG. 18 is a schematic diagram of the capacitive acceleration sensor operation;

fig. 19 is a schematic diagram of triaxial tilt angle force-bearing decomposition.

Detailed Description

The low measurement accuracy of the measurement deviation of the timing angle of the engine timing system is mainly caused by the following two reasons: 1. assembly deviation of the engine itself; 2. measuring deviation of the measuring tool.

1. Assembly deviation of engine self-equipment

The signal wheel used by the cam shaft of some types of engines is a metal workpiece which is screwed and matched by a shaft hole, and the assembly deviation with the cam shaft angle is easy to exist.

The acquisition of engine crankshaft speed signals of some models requires the reliance on other assemblies that mate with the crankshaft. The mechanical position of the crankshaft timing and the rear oil seal flange assembly have assembly deviation, and the rear oil seal flange assembly and the signal gear ring have assembly deviation. The measured signal is correct only if the mechanical timing position of the rear oil seal flange assembly and the crankshaft is ensured to be correct. However, the oil seal flange assembly after on-line assembly, particularly, assembly deviation exists when the oil seal flange assembly is assembled manually (trial production and repair), and the machining precision of a mechanical tool and the assembly mode are caused to be deviated, and the deviations are accumulated and overlapped, so that the measurement precision of the timing angle of the engine is affected, and the requirement of the timing assembly precision cannot be met.

2. Measuring deviation of measuring tool

The engine cold test equipment station has larger volume and poorer flexibility, and an adapter and related accessories matched with the engine cold test equipment station are required to be manufactured for different engine models. The price of the engine is over millions of RMB, the equipment is long in installation and debugging period and high in maintenance cost, and the method is suitable for mass production detection of the assembly line.

The universal mechanical timing clamp is generally purely mechanically adjusted, and the mechanical timing clamp is fixed after the engine is manually driven to a cylinder top dead center. The mechanical timing clamp cannot measure the timing angle deviation and quantitatively record, and the precision is poor. Furthermore, mechanical timing clamps do not enable static and dynamic engine timing angle offset measurements.

Some mechanical timing clamps also need to be matched with some mechanical measuring tools for measurement or visual detection, and the engine crankshaft is manually driven to a cylinder top dead center, so that the precision is poor, the operation is complex, the cam shaft and the crankshaft timing angle deviation cannot be measured, and the dynamic engine timing angle deviation measurement cannot be realized.

The universal mechanical timing pointer angle measuring tool has to remove the ignition coil and the spark plug of the engine to find the position of the top dead center of one cylinder of the engine, manually dial the engine crankshaft, and determine the top dead center of one cylinder by reading the scales through the pointer dial of the mechanical timing pointer angle measuring tool. However, the mechanical timing pointer angle measuring tool cannot measure the timing angle deviation of the cam shaft, and the timing angle deviation of the cam shaft corresponding to the cam shaft cannot be measured, so that the precision is poor. In addition, mechanical timing pointer angle measurement tools are relatively complex to use and operate, and dynamic engine timing angle deviation measurement cannot be achieved.

The oscilloscope method uses the oscilloscope to detect the signals of the camshaft and the crank shaft position sensor and compare the signals with the theoretical values to confirm the angle deviation values, however, the correction measure must be based on a complete engine system, and meanwhile, the broken line measurement must be carried out, so that the integrity and the safety of the engine are affected. In addition, the instrument cannot be used as a rework tool.

When the engine timing system is assembled (manufactured and reworked), the visual detection of the marks or the casting marks is required to be carried out on related parts, and the deviation among the parts in the assembly process of the engine timing system is larger and the errors are accumulated due to the existence of mark processing errors, artificial visual errors and the length tolerance of a timing chain (timing belt), so that the stability and the accuracy of the whole structure of the engine are directly influenced. The tool must manually drive the engine crankshaft to a cylinder top dead center, is relatively complex to operate, and cannot measure cam shaft and crankshaft timing angle deviations.

In the embodiment of the invention, the rotating shaft is connected with the engine camshaft, the timing angle of the engine camshaft can be directly measured through the second inclination angle measuring device fixed at the second end of the rotating shaft, and compared with the existing manual estimation deviation angle, the accuracy of the engine camshaft timing angle measured by the engine camshaft timing angle measuring device provided by the embodiment of the invention is higher, so that the measuring accuracy of the engine timing angle deviation can be improved.

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments accompanied with figures are described in detail below.

The engine camshaft timing angle measurement device may include a rotating shaft and a second inclination measurement device. The first end of the rotating shaft is connected with an engine cam shaft, and the second end of the rotating shaft is fixed with the second inclination angle measuring device. The second inclination measuring device is used for measuring the timing angle of the engine camshaft.

By adopting the engine camshaft timing angle measuring device provided by the embodiment of the invention, the engine camshaft timing angle measuring device is arranged on the engine camshaft, and the engine camshaft timing angle measuring device is rotated, so that the angle reading can be read from the second inclination angle measuring device, and the angle of the engine camshaft is obtained.

In an implementation, the engine camshaft timing angle measurement device may further include: and fixing the shaft sleeve. The fixed shaft sleeve can be sleeved on the rotating shaft, and the fixed shaft sleeve can increase the stability of the connection between the rotating shaft and the cam shaft. The waist hole is formed in the fixed shaft sleeve, so that the fixed shaft sleeve can be matched with different types of engines and different shapes of cylinder head covers, the engine camshaft timing measuring device can be freely adjusted and fixed in the Z-axis direction, and the universality of the engine camshaft timing measuring device is improved.

In specific implementation, the fixed shaft sleeve is provided with a pin stopping hole, and the rotating shaft is provided with a pin stopping groove matched with the pin stopping hole. Bolts can be used to penetrate through the pin stopping holes and the pin stopping grooves to fix the fixed shaft sleeve and the rotating shaft. After determining engine timing using a conventional mechanical clamp, an engine base offset may be determined through the stop pin slot and the stop pin hole, and after determining the engine base offset, the engine camshaft timing angle is measured using the engine camshaft timing angle measuring device.

In an embodiment of the present invention, the engine camshaft timing angle measurement device may further include: and adjusting the rotating shaft sleeve and the adjusting arm. The adjusting rotating shaft sleeve can be sleeved on the rotating shaft. The adjusting arm can be detachably connected with the adjusting rotating shaft sleeve. The shaft head of the adjusting arm can be provided with threads, and can be matched with the threaded holes on the adjusting rotating shaft sleeve, so that when the adjusting arm is connected with the adjusting rotating shaft sleeve, the adjusting rotating shaft sleeve can be rotated by the adjusting arm to adjust the angle of the engine cam shaft.

In an implementation, the engine camshaft timing angle measurement device may further include: and the camshaft sliding support is sleeved on the rotating shaft.

In an implementation, the engine camshaft timing angle measurement device may further include: and the camshaft sliding support is sleeved on the rotating shaft. The camshaft sliding support can fix the engine camshaft timing angle measuring device.

When the engine camshaft is a single overhead camshaft, the number of the rotating shafts is 1, the number of the fixed shaft sleeves can be 1, and the adjusting rotating shaft sleeve and the adjusting arm are both one.

Fig. 1 shows a schematic structural diagram of an engine camshaft timing angle measurement device according to an embodiment of the present invention, fig. 2 shows a cross-sectional view of an engine camshaft timing angle measurement device according to an embodiment of the present invention, fig. 3 shows a disassembled view of an engine camshaft timing angle measurement device according to an embodiment of the present invention, and fig. 4 shows a schematic structural diagram of an engine camshaft timing angle measurement device according to an embodiment of the present invention, which is relatively positioned with respect to an engine camshaft. The engine camshaft timing angle measuring device will be described in detail below with reference to fig. 1 to 4, when the engine camshaft is a double overhead camshaft.

When the engine camshaft is a double overhead camshaft, the rotating shaft includes an intake camshaft and an exhaust camshaft. The engine camshaft timing angle measuring device includes: the device comprises an air inlet camshaft rotating shaft 141, an air inlet fixed shaft sleeve 151 and an air inlet adjusting rotating shaft sleeve 161, wherein the air inlet fixed shaft sleeve 151 and the air inlet camshaft rotating shaft 141 are coaxially fixed, the air inlet fixed shaft sleeve 151 can be matched with cylinder head covers of different shapes according to the types of engines, and the degree of freedom in the Z-axis direction is realized, and the whole camshaft timing angle measuring device is fixed; an adjusting arm threaded hole is formed in the outer circle of the air inlet adjusting rotating shaft sleeve 161 and can be matched with the adjusting arm 171, so that the angle of the engine camshaft can be manually adjusted; an exhaust camshaft rotating shaft 142, an exhaust fixing shaft sleeve 152 and an exhaust adjusting rotating shaft sleeve 162, wherein the exhaust fixing shaft sleeve 152 and the exhaust camshaft rotating shaft 142 are coaxially fixed, the exhaust fixing shaft sleeve 152 can be adapted to cylinder head covers of different shapes according to the types of engines, and the degree of freedom adjustment in the Z-axis direction is realized and the whole camshaft timing angle measuring device is fixed; an adjusting arm threaded hole is formed in the outer circle of the exhaust adjusting rotating shaft sleeve 162 and can be matched with the adjusting arm 172, and therefore the angle of the engine camshaft can be adjusted manually.

In a specific implementation, the air intake fixing shaft sleeve 151 is provided with a pin stop hole 1511, the air intake camshaft rotating shaft 141 is provided with a pin stop groove 1411, the pin stop hole 1511 is matched with the pin stop groove 1411, and the air intake camshaft rotating shaft 141 can be telescopic to adjust the relative position of the air intake camshaft rotating shaft 141 and the air intake camshaft. A pin hole (not shown) is formed in the exhaust fixing sleeve 152, a pin stopping groove 1421 is formed in the exhaust camshaft rotary shaft 142, the pin stopping hole is matched with the pin stopping groove 1421, and the relative position of the exhaust camshaft rotary shaft 142 and the exhaust camshaft can be adjusted by telescoping the exhaust camshaft rotary shaft 142.

In a specific implementation, when the engine camshaft is a dual overhead camshaft, the camshaft sliding support includes: an intake camshaft sliding bracket 181 and an exhaust camshaft sliding bracket 182, wherein: the intake camshaft sliding bracket 181 is sleeved on the intake camshaft rotating shaft 141 and is clamped with the exhaust camshaft sliding bracket 182; the exhaust camshaft sliding bracket 182 is sleeved on the exhaust camshaft rotating shaft 142.

In a specific implementation, the spacing between the intake camshaft and the exhaust camshaft of different models of engines is different. To improve the versatility of the engine timing angle measurement system, in one embodiment of the present invention, one of the intake camshaft sliding bracket 181 and the exhaust camshaft sliding bracket 182 is provided with a connecting portion 1811, and the other is provided with a receiving hole 1821 for receiving the connecting portion. By adjusting the length of the connection portion 1811 extending into the receiving hole 1821, the distance between the intake camshaft and the exhaust camshaft can be adjusted, thereby achieving degree of freedom adjustment in the X-axis direction to accommodate different types of engines. For example, the intake camshaft sliding bracket 181 is provided with a connection portion 1811, and the exhaust camshaft sliding bracket is provided with a receiving hole 1821.

In an embodiment of the present invention, a groove is provided at a second end of the rotating shaft, a bottom of the groove is a plane and passes through an axis of the rotating shaft, and the second inclination angle measurement device is fixed in the groove. This may reduce the computational complexity of the engine timing angle measurement system.

The embodiment of the invention also provides an engine timing angle measuring system which can comprise an engine crankshaft timing angle measuring device and an engine camshaft timing angle measuring device. The structure and the working flow of the engine camshaft timing angle measuring device can be referred to the description in the engine crankshaft timing angle measuring device provided by any embodiment of the invention. The structure and the operation flow of the engine crankshaft timing angle measuring device are described below.

Fig. 6 is a schematic view showing the structure of an engine crank timing angle measuring device according to an embodiment of the present invention, fig. 7 is a sectional view of fig. 6 in A-A direction, and fig. 8 is a disassembled view of an engine crank timing angle measuring device according to an embodiment of the present invention. The structure of the engine crankshaft timing angle measuring device will be described in detail with reference to fig. 6 to 8.

In particular implementations, the engine crankshaft timing angle measurement device may be mounted at a rear end of the crankshaft, where the rear end of the crankshaft refers to an end proximate to the flywheel portion. The engine crankshaft timing angle measurement apparatus may include: a spindle bracket 12, a fixing portion 11, and a first inclination measuring device 13. One end of the fixing part 11 is fixedly connected with the engine crankshaft, and the other end is connected with the rotating shaft frame 12 and can rotate relative to the rotating shaft frame 12. The first inclination measuring device 13 may be fixed to the rotating shaft frame 12. Bolts may be used to secure the engine timing angle measurement device to the rear end of the crankshaft. For example, the fixing portion 11 is fixed to the crankshaft by a bolt.

In an embodiment of the present invention, the fixing portion 11 may be provided with a protrusion 111, and the rotating shaft frame 12 may be provided with a groove for receiving the protrusion 111. When the protrusion 111 is engaged with the groove, the rotating shaft frame 12 rotates relative to the fixing portion 11 when the protrusion 111 rotates in the groove.

In an embodiment of the present invention, the rotating shaft frame 12 may be provided with a receiving portion 128, and the first inclination measuring device 13 is disposed in the receiving portion 128. The plane of the accommodating portion 128 may pass through the axis of the rotating shaft frame 12, so that the first inclination angle measuring device 13 is installed and placed, which can reduce the computational complexity in the process of measuring the timing angle of the engine crankshaft.

In a specific implementation, the rotating shaft frame 12 may be provided with a cylinder reference position positioning hole 121 and a crankshaft reference position positioning hole 123. The cylinder block reference position positioning hole 121 and the crankshaft reference position positioning hole 123 can determine the crankshaft cylinder top dead center.

In one embodiment of the present invention, a cylinder reference position adapting pin 122 that mates with the cylinder reference position locating hole 121 and a crankshaft reference position adapting pin 124 that mates with the crankshaft reference position locating hole 123 may be used to determine the position of a cylinder top dead center of the crankshaft.

Specifically, after the engine crankshaft timing angle measuring device is fixed to the rear end of the crankshaft, the turret 12 is rotated, and when the cylinder block reference position positioning hole 121 is opposed to the machining reference position positioning hole of the engine cylinder block, the cylinder block reference position adapting pin 122 is inserted into the cylinder block reference position positioning hole and stays for a while, at which time the first inclination angle measuring device 13 obtains a first angle, which is also the reference position of the crankshaft timing. Then, the cylinder block reference position adapting pin 122 is taken out, the rotation of the rotating shaft bracket 12 is continued, and when the crankshaft reference position positioning hole 123 is opposite to the third unequally spaced hole at the rear end of the crankshaft, the crankshaft reference position adapting pin 124 is inserted and stays for a while, and at this time, the first inclination angle measuring device 13 obtains the second angle. After the two positioning steps, the position of the top dead center of one cylinder of the crankshaft can be determined according to the obtained first angle and the second angle.

In an embodiment of the present invention, the first inclination measuring device 13 is a capacitive acceleration sensor. The inclination angle error of the engine can be effectively eliminated by utilizing the sensing characteristic of the capacitive acceleration sensor to the G gravity direction.

After determining the engine cylinder top dead center through the cylinder block reference position positioning hole 121 and the crankshaft reference position positioning hole 123, the first inclination angle measurement device 13 may measure the engine crankshaft timing angle.

From the above, the calibration of the engine crankshaft timing angle measuring device is performed according to the cylinder body reference position locating hole and the crankshaft reference position locating hole on the rotating shaft bracket, and the first inclination angle measuring device is adopted to measure the engine crankshaft timing angle, so that the deviation of the timing system is determined without collecting signals output by the crankshaft signal wheel, and the manual estimation is also not needed, and the confirmation of the top dead center of one cylinder of the engine can be realized only through the existing cylinder body reference position locating hole and the crankshaft reference position locating hole of the engine, so that the measurement precision of the engine timing angle deviation can be improved.

In particular embodiments, some engine speed sensors are mounted on the rear oil seal flange assembly, and engine crankshaft speed signal acquisition is dependent on another assembly member that mates with the crankshaft, and the mechanical position of the crankshaft timing is offset from the rear seal flange assembly. Only when the mechanical timing position of the rear oil seal flange assembly and the crankshaft is correct, the measured signal is correct, and the assembly deviation exists in the process of on-line assembly of the rear oil seal flange assembly, particularly in the process of manual assembly (trial production and repair), and the assembly deviation is accumulated and overlapped due to the machining precision of a mechanical tool and the assembly mode, so that the requirement of the engine timing assembly precision cannot be met.

To solve the above-described problem, in an embodiment of the present invention, the engine crankshaft timing angle measurement apparatus may further include: the signal wheel positioning hole 125 and the signal wheel timing detection fitting pin 126. The signal wheel positioning hole 125 is disposed on the rotating shaft frame 12, the rotating shaft frame 12 rotates, the signal wheel positioning hole 125 is opposite to the timing signal hole on the rear sealing flange assembly, the signal wheel timing detection adapting pin 126 is inserted into the timing signal hole on the rear sealing flange assembly, at this time, the angle measured by the first inclination angle measuring device 13 is the angle deviation between the crankshaft timing position and the signal wheel, so that the mechanical position of the crankshaft timing and the rear sealing flange assembly have assembly deviation or the angle deviation caused by the defects of the parts.

In an implementation, the signal wheel alignment hole 125 may be located between the cylinder reference position alignment hole 121 and the crankshaft reference position alignment hole 123. It will be appreciated that the relative positions of the signal wheel alignment holes 125, the cylinder block reference position alignment holes 121 and the crankshaft reference position alignment holes 123 will be different depending on the type of engine, as long as the positions of the corresponding holes on the engine are matched.

When the engine timing angle measuring system provided by the embodiment of the invention is used for measuring the engine timing angle deviation, the engine timing angle can be obtained by reading the first inclination angle measuring device 13 and the engine camshaft timing angle can be read by reading the second inclination angle measuring device without disassembling parts in the engine.

The first inclination angle measuring device 13 and the second inclination angle measuring device in the engine timing angle measuring system provided by the embodiment of the invention are respectively arranged on the crankshaft and the camshaft. The first inclination angle measuring device and the second inclination angle measuring device can rotate along with the timing system, and can collect angle rotation signals of the crankshaft and the camshaft to realize static and dynamic measurement. When the first inclination angle measuring device and the second inclination angle measuring device are both capacitive acceleration sensors, the inclination angle error of the engine can be effectively eliminated by utilizing the sensing characteristic of the capacitive acceleration sensors to the G gravity direction, and the conversion of the timing angle deviation of the absolute position between the crankshaft and the camshaft is realized. The capacitive acceleration sensor integrates a wireless data signal transmitter, is matched with a terminal wireless data signal receiver, can realize wireless data transmission, and displays corresponding values at the terminal.

The engine timing angle measuring system provided by the embodiment of the invention can rapidly, accurately and effectively measure the engine timing deviation angle at any position of the crankshaft and the camshaft, so as to diagnose and analyze whether faults are caused by defects of engine parts, assembly reasons, bench tests, whole vehicle tests and the like. Meanwhile, the engine timing angle measuring system can realize the degree of freedom adjustment in the X, Y axial direction so as to adapt to flexible operation of different types and different types of engines and static and dynamic measurement of timing angles, can also analyze and monitor collected data, improves the assembly quality of the engine, and can be used as a repair type engine timing adjusting tool.

In addition, when the engine timing angle measuring system provided by the embodiment of the invention is used for detecting the engine timing angle, broken line measurement is not needed, and the integrity and the safety of the engine are not affected. The engine timing angle measurement system is small in size, flexible and convenient in use process and convenient for mass production. The crankshaft timing angle measuring device and the camshaft timing angle measuring device in the engine timing angle measuring system can be used independently and respectively as a crankshaft timing angle measuring tool and a camshaft timing angle measuring tool. The engine timing angle measurement system can realize bidirectional measurement of crankshaft timing and camshaft timing at any position within plus or minus 90 degrees (180 degrees absolute value) of a cylinder top dead center. The engine timing angle measurement system can also measure the assembly deviation of the timing gear ring of the engine rear flange assembly, including dynamic measurement and static measurement. The engine timing angle measurement system can also be used as an auxiliary measurement tool for compression ratio measurement, engine valve lift measurement, overlap angle measurement and the like.

The embodiment of the invention also provides an engine timing angle measuring method, and the method is described in detail below with reference to the accompanying drawings.

Referring to fig. 9, a flowchart of a method of measuring engine timing angle in an embodiment of the invention is provided. The engine timing angle measurement method may include the following steps.

Step 91, determining a cylinder top dead center of the engine.

To improve the accuracy of the absolute position determination of the engine crankshaft. And simplifying the operation, in one embodiment of the present invention, the engine timing angle measuring device provided in the above embodiment of the present invention may be used to determine the engine crankshaft timing angle and absolute position. Specifically, the fixing portion 11 of the crankshaft timing angle measuring device is connected to the rotating shaft frame 12, the fixing portion 11 is fixed to the engine crankshaft, the rotating shaft frame 12 is rotatable with respect to the fixing portion 11, and the second inclination angle measuring device is fixedly mounted on the rotating shaft frame 12. After the installation, the relative position of the engine crankshaft and the engine crankshaft timing angle measuring device at the top dead center of a cylinder can be referred to as fig. 12, wherein the first inclination angle measuring device is Sensor1.

When the crankshaft timing angle measuring device is installed, the crankshaft can be positioned at any position, the absolute horizontal line is taken as a zero deviation position after the crankshaft timing angle measuring device is installed, the mechanical timing position of the crankshaft is positioned at a reference position, the rotating shaft bracket 12 is rotated to a first position, the cylinder body reference position positioning hole 121 is used for determining the engine timing reference position, namely, the cylinder body reference position adapting pin 122 is inserted into the engine timing reference hole and is also the reference position of the crankshaft timing. And taking out the cylinder body reference position adapting pin 122, continuing to rotate the rotating shaft frame 12 to the third non-equidistant hole at the rear end of the crankshaft, and inserting and confirming the crankshaft reference position adapting pin 124 when the crankshaft reference position positioning hole 123 is coincident with the third non-equidistant hole at the rear end of the crankshaft.

After the two measurement positions are confirmed, the sensing characteristic of the capacitive acceleration sensor on the G gravity direction is utilized, the inclination angle error of the engine can be effectively eliminated, and the top dead center position of the crankshaft cylinder is determined according to the first angle corresponding to the first position and the second angle corresponding to the second position of the first inclination angle measuring device. The absolute crankshaft position θ _kw is read from the first inclination measuring device.

θ_kw＝θ_m+θ_s1+θ₁； (1)

Wherein, θ _kw is the output value of the first inclination angle measurement device; θ _m is the engine base offset; θ _s1 is the first inclination measuring device installation deviation; θ ₁ is the position of the crankshaft relative to a cylinder top dead center.

In an embodiment of the present invention, the first inclination measuring device, the second inclination measuring device, the third inclination measuring device and the fourth inclination measuring device may be capacitive acceleration sensors.

In a specific implementation, in measuring the timing deviation angle of the engine in the actual state, it is necessary to calculate the position deviation angle of the engine in the actual state, and the installation deviation angles of the crankshaft rotation angle, the camshaft rotation angle, the first inclination angle measuring device, the third inclination angle measuring device and the fourth inclination angle measuring device. Referring to fig. 13 to 16, reference symbol OT denotes a reference position of the engine, an intake camshaft 1, an exhaust camshaft 2, and a crankshaft 50. Taking a double overhead camshaft as an example, there are mainly the following cases.

When the engine is in the state shown in fig. 13, the engine is at an ideal position, i.e., the engine base has no deviation, and the crankshaft timing has no deviation, at which time θ _m＝0,θ₁ =0.

When the engine is in the state shown in fig. 14, there is no deviation in the crank timing, and at the same time, there is a deviation in the engine base, which can be obtained by a capacitive acceleration sensor.

When the engine is in the state shown in fig. 15, the engine base has no deviation, that is, θ _m =0. The deviation of the crankshaft timing can be measured by an engine crankshaft timing angle measuring device, namely, theta ₁≠0,θ_s1 is the installation deviation of the first inclination angle measuring device, and calibration records can be obtained. The ideal real position of the engine is that the center of the passing crankshaft is parallel to the ground, the Y-axis and the g-gravity axis of the center of the passing crankshaft are perpendicular to the ground, namely, the position of the upper dead center of one cylinder of the crankshaft is deviated from the measured crankshaft timing position, and the corresponding deviation value can be calculated through a capacitive acceleration sensor and a deviation algorithm.

When the engine is in the state shown in fig. 16, the crankshaft is biased, while the engine base is biased. The total deviation value of the engine base and the crankshaft timing can be calculated through a capacitive acceleration sensor, the cylinder reference hole is locked by using the cylinder reference position adapting pin 122 to determine the angle relation between the crankshaft and the position of the engine timing (a cylinder Top dead center Top DEAD CENTER), and then the crankshaft reference position is locked by using the crankshaft reference position adapting pin 124. And then the ideal timing position of the engine crankshaft is that the center X axis is parallel to the ground, and the center Y axis and g gravity axis are perpendicular to the ground, namely the difference value of the ideal timing deviation of the engine crankshaft and the condition that the crankshaft timing deviation exists is calculated.

In particular embodiments, a conventional mechanical crankshaft timing clamp or marker may be used to run the engine crankshaft near Top dead center (Top DEAD CENTER) of a cylinder, and then the conventional mechanical crankshaft timing clamp is mounted to the rear end of the crankshaft to complete the confirmation of Top dead center of a cylinder of the engine. Depending on the type of engine, a marker method may also be used to determine engine cylinder top dead center.

The absolute horizontal line is taken as a zero deviation position, the mechanical timing position of the crankshaft is positioned at a reference position, and the clockwise direction is taken as a positive direction. When the traditional mechanical crankshaft timing clamp or marking method is adopted to confirm the top dead center of one cylinder of the crankshaft,

Θ ₁: the crankshaft has no timing deviation from the mechanical top dead center rotational angle θ ₁ =0, i.e., the default engine crankshaft portion has no timing deviation, so the timing deviation is zero.

Θ _s1: since there is no capacitive acceleration sensor such as a conventional mechanical jig or a labeling method, the capacitive acceleration sensor has a mounting deviation θ _s1 =0.

Θ _kw、θ_m: the crankshaft absolute position θ _kw is equal to the engine base offset θ _m. Similarly, a crankshaft cylinder top dead center has been determined in which θ _kw＝θ_m, where engine base offset θ _m can be calculated from the capacitive acceleration sensor on the camshaft, i.e., the camshaft portion alone can be self-calculated for engine base offset.

Step 92, an absolute position of an engine camshaft is obtained using an engine camshaft timing angle measurement device.

When determining the top dead center of a crankshaft cylinder by using a conventional mechanical crankshaft timing clamp, the engine timing position needs to be calibrated by using a camshaft timing calibration block before the absolute position of the engine camshaft is acquired by using an engine camshaft timing angle measurement device, wherein the structure of the camshaft timing calibration block can be seen in fig. 5.

Specifically, before each measurement of engine camshaft offset, whether intake camshaft timing offset or exhaust camshaft timing offset is measured, a camshaft timing calibration block is mounted on the camshaft to calibrate the engine timing position. Specifically, the intake camshaft 1 is connected to the shaft hole 3 of the camshaft timing calibration block, and the exhaust camshaft 2 is connected to the shaft hole 4 of the camshaft timing calibration block. When the camshaft timing calibration block can be properly mounted on the engine camshaft, the engine is in a timing position. Then, an engine camshaft timing angle measurement device is mounted to the engine camshaft, and a reading of the second inclination measurement device is taken, thereby obtaining an absolute position of the engine camshaft.

In a specific implementation, an engine camshaft timing angle measurement device is mounted to an engine camshaft, wherein the engine camshaft timing angle measurement device comprises: the first end of the rotating shaft is connected with the engine cam shaft, and the second inclination angle measuring device is fixed at the second end of the rotating shaft; acquiring the engine camshaft timing offset angle from the second inclination measuring device; and obtaining the absolute position of the cam shaft according to the engine deviation, the cam shaft rotation angle, the installation deviation of the inclination angle measuring device and the timing deviation angle of the cam shaft of the engine.

In an embodiment of the present invention, when the camshaft is a double overhead camshaft, a third inclination angle measurement device is installed on the intake camshaft, the intake camshaft timing deviation angle is obtained from the third inclination angle measurement device, a fourth inclination angle measurement device is installed on the exhaust camshaft, and the exhaust camshaft timing deviation angle is obtained from the fourth inclination angle measurement device. The absolute position of the intake camshaft can be obtained using equation (2). And (3) obtaining the absolute position of the exhaust camshaft by adopting the formula.

Wherein alpha _ni is the absolute position of the intake camshaft, theta _m is the engine base deviation, theta _s2 is the third inclination angle measuring device installation deviation,For intake camshaft rotation angle, θ _ni is intake camshaft timing offset, θ ₁ is crankshaft relative mechanical top dead center rotation angle, α _no is exhaust camshaft absolute position, θ _s3 is fourth inclination measuring device installation offset, and θ _n0 is exhaust camshaft timing offset.

If the engine has no deviation, the confirmation of the top dead center of one cylinder of the engine is completed.

Fig. 10 shows a schematic view of the timing position of the camshaft when the intake camshaft is deviated, and fig. 11 shows a schematic view of the timing position of the camshaft when the exhaust camshaft is deviated, wherein the third inclination angle measuring device is Sensor2, and the fourth inclination angle measuring device is Sensor3.

Step 93, calculating an engine timing angle according to the obtained absolute position of the engine camshaft and the absolute position of the engine crankshaft.

In an implementation, the intake camshaft relative crankshaft position deviation θ _ni may be derived using equation (4).

The exhaust camshaft relative crankshaft position deviation θ _no can be found using equation (5).

The relative positional deviation θ _io of the intake camshaft and the exhaust camshaft can be obtained by using the formula (6).

θ_io＝a_ni-a_no-θ_s2+θ_s3 (6)

Wherein θ _m is the first inclination angle measurement device output value, a _ni is the third inclination angle measurement device output value, and a _no is the fourth inclination angle measurement device output value.

In a specific implementation, the first inclination angle measuring device, the second inclination angle measuring device, the third inclination angle measuring device and the fourth inclination angle measuring device all adopt capacitive acceleration sensors. The working principle of the capacitive acceleration sensor is as follows:

Referring to fig. 17, a schematic structural diagram of a capacitive acceleration sensor according to an embodiment of the present invention is given. Fig. 18 is a schematic diagram of the operation of the capacitive acceleration sensor. The operation principle of the capacitive acceleration sensor will be described with reference to fig. 17 and 18.

In a specific implementation, a capacitive acceleration sensor generally adopts a spring-mass system, in which one electrode is fixed, and the other changing electrode is an elastic diaphragm, and when the mass moves under the action of acceleration, the gap between the mass and the fixed electrode is changed, so that the capacitance value is changed. The wireless data signal transmitter is integrated in the capacitive acceleration sensor, and wireless data transmission can be realized by matching with the terminal wireless data number limiting receiver.

Based on newton's second law f=ma, when the capacitive acceleration sensor is placed stationary horizontally on a plane, the capacitive acceleration sensor receives only G gravity and the reaction force of the plane to itself.

When the capacitive acceleration sensor is used to measure the tilt angle α of an object, which is generated by the capacitive acceleration sensor with respect to the direction of earth gravity, the tilt angle may be determined by using the gravity vector and its projection onto the capacitive acceleration sensor axis due to gravity. Then, the angle value is detected by the sensing element, or the gravity acceleration vertical to the ground is converted into the strain quantity of the sensing element to be output into an electric signal. As shown in fig. 17, the mass m is known, and the capacitive acceleration sensor receives gravity when it is placed stationary, so there is a gravitational acceleration of 1 g. By taking advantage of this property, the tilt angle in the vertical plane can be calculated by measuring the component of the gravitational acceleration on the X, Y axis. The gravity acceleration has a component acting on the direction of the sensitive axis Ax of the sensor and satisfies the following conditions:

sinα＝Ax/g (7)

Ax=g sin α (8)

Where Ax is a measure of acceleration, g is gravitational acceleration, and α is the engine timing measurement angle.

According to hooke's law f= -K x, i.e. the force F experienced by the mass at a point x away from the equilibrium position of the spring is proportional to the displacement magnitude and the opposite direction is called linear restoring force. The capacitive acceleration sensor can be seen from a mechanical point of view as a mass-spring-damper system. When the sensor generates an inclination angle relative to the earth gravity direction, the sensor is obtained by measuring a mass-spring-damping system:

F＝-kx＝ma； (9)

a＝k/m*x； (10)

a＝d^2x/dt^2； (11)

C＝(ε·S)/x； (12)

According to the formula (10) and the formula (12), the acceleration a born by the capacitive acceleration sensor is inversely proportional to the electric charge C between the electrodes.

a＝k/m*(ε·S)/C； (13)

The acceleration a can be obtained by measuring the displacement x and integrating the displacement x, so that the force F applied to the displacement x is obtained, and f=ax.

Ax＝gsinα,Ay＝gcosα； (14)

α＝arctan Ax/Ay； (15)

Where k is the stiffness coefficient, m is the mass, and x is the displacement.

However, in practical applications, it is difficult to ensure that the inclination occurs in the X-Y plane, and referring to the triaxial inclination force decomposition schematic diagram shown in fig. 19, when the inclination measurement calculation formula of three capacitive acceleration sensors is adopted in the X-Y-Z plane, the following can be expanded:

Wherein Ax is a measured value of acceleration in the x-axis direction, ay is a measured value of acceleration in the y-axis direction, az is a measured value of acceleration in the z-axis direction, alpha _x is an included angle between Ax and gravity G, alpha _y is an included angle between Ay and gravity G, alpha _z is an included angle between Az and gravity G, charges between C electrodes, k is a stiffness coefficient, m is a mass of the mass block, x is displacement, F is force applied to the displacement x, G is gravity acceleration, G is gravity, alpha is engine timing angle deviation, epsilon is dielectric constant of a medium between capacitor plates, and S is area of the capacitor plates.

In an embodiment of the present invention, after the engine timing is calibrated by using the camshaft timing calibration block, the engine camshaft timing angle measurement device provided in the above embodiment of the present invention may be used to measure the engine timing deviation in the following manner, which is described in detail below with reference to fig. 3.

The camshaft timing angle measuring device is fixed to the engine by waist holes and fasteners on the intake fixing boss 151 and the exhaust fixing boss 152, and at this time, the engine camshaft is not connected to the intake camshaft rotating shaft 141 and the exhaust camshaft rotating shaft 142, the pin-stopping groove 1411 on the intake camshaft rotating shaft 141 is not fastened to the pin-stopping hole 1511 on the intake fixing boss 151 by bolts, and the pin-stopping groove 1421 on the exhaust camshaft rotating shaft 142 is not fastened to the pin-stopping hole on the exhaust fixing boss 152 by bolts. And respectively reading the third inclination angle measuring device and the fourth inclination angle measuring device, and calculating the triaxial inclination angles by adopting formulas (16), (17), (18) and (19), namely determining the inclination angle of the engine base of the plane where the third inclination angle measuring device is positioned and the inclination angle of the engine base of the plane where the fourth inclination angle measuring device is positioned after the measurement of Ax, ay and Az.

Pushing the camshaft timing angle measuring device, inserting the exhaust camshaft rotating shaft 142 into the exhaust camshaft 2, inserting the intake camshaft rotating shaft 141 into the intake camshaft 1, and changing the relative positions of the stop groove 1411 and the stop hole 1511 when pushing the intake camshaft rotating shaft 141 because the groove-shaped length of the stop groove 1411 is longer than the aperture of the stop hole 1511; accordingly, when the exhaust camshaft rotational shaft 142 is pushed, the relative positions of the pin stopping groove 1421 and the pin stopping hole on the exhaust fixing boss 152 change. The pin-stopping groove 1411 on the intake camshaft rotation shaft 141 and the pin-stopping hole 1511 on the intake fixing boss 151 are fixed by bolts, and the pin-stopping groove 1421 on the exhaust camshaft rotation shaft 142 and the pin-stopping hole on the exhaust fixing boss 152 are fixed by bolts. And measuring the timing deviation of the intake camshaft of theta _ni and the timing deviation of the exhaust camshaft of theta _n0. The ideal timing position of the engine camshaft is that the X axis passing through the center of a circle is parallel to the ground, the Y axis passing through the center of a circle is perpendicular to the ground with the g gravity axis, and finally the algebraic sum of the ideal timing deviation of the engine camshaft and the condition that the camshaft timing deviation exists is calculated through formulas (16), (17), (18), (19), (2) and (3). The relative positional deviation of the intake camshaft and the exhaust camshaft can be calculated by the formula (6).

The deviation algorithm of the cam shaft timing angle measuring device is used for calculating the timing deviation of the intake cam shaft relative to the top dead center of one cylinder of the crank shaft through the formula (4) and the formula (5), and the position deviation of the exhaust cam shaft relative to the crank shaft can be displayed at the PC end through wireless transmission, wherein the cam shaft can be a double overhead DOHC-intake and exhaust cam shaft or a single overhead OHC-single cam shaft.

Those of ordinary skill in the art will appreciate that all or part of the steps in the various methods of the above embodiments may be implemented by a program to instruct related hardware, the program may be stored in a computer readable storage medium, and the storage medium may include: ROM, RAM, magnetic or optical disks, etc.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be assessed accordingly to that of the appended claims.

Claims (21)

1. An engine camshaft timing angle measurement device, comprising: rotation axis and second inclination measuring device, wherein:

the first end of the rotating shaft is connected with an engine cam shaft;

The second inclination angle measuring device is fixed at the second end of the rotating shaft and is used for measuring the timing angle of the engine camshaft;

Further comprises: the fixed shaft sleeve is sleeved on the rotating shaft;

The fixed shaft sleeve is provided with a pin stopping hole, the rotating shaft is provided with a pin stopping groove matched with the pin stopping hole, and after the engine timing is determined by adopting a traditional mechanical clamp, the deviation of the engine base is determined through the pin stopping groove and the pin stopping hole.

2. The engine camshaft timing angle measurement device according to claim 1, further comprising: adjusting the rotating shaft sleeve and the adjusting arm, wherein:

The adjusting rotating shaft sleeve is sleeved on the rotating shaft;

the adjusting arm is detachably connected with the adjusting rotating shaft sleeve and is suitable for rotating the adjusting rotating shaft sleeve to adjust the angle of the engine cam shaft.

3. The engine camshaft timing angle measurement device according to claim 1, further comprising: and the camshaft sliding support is sleeved on the rotating shaft.

4. The engine camshaft timing angle measurement device of claim 3, wherein the engine camshaft is a dual overhead camshaft, comprising: an intake camshaft and an exhaust camshaft.

5. The engine camshaft timing angle measurement device according to claim 4, wherein the rotating shaft includes:

The first end of the air inlet cam shaft is connected with the air inlet cam shaft; and the first end of the exhaust camshaft rotating shaft is connected with the exhaust camshaft.

6. The engine camshaft timing angle measurement device according to claim 5, wherein the camshaft sliding bracket includes: intake camshaft sliding support and exhaust camshaft sliding support, wherein:

the air inlet cam shaft sliding support is sleeved on the air inlet cam shaft rotating shaft and is clamped with the air outlet cam shaft sliding support;

The exhaust camshaft sliding support is sleeved on the exhaust camshaft rotating shaft.

7. The engine camshaft timing angle measurement device according to claim 6, wherein one of the intake camshaft sliding bracket and the exhaust camshaft sliding bracket is provided with a connecting portion, and the other is provided with a receiving hole for receiving the connecting portion.

8. The engine camshaft timing angle measurement device of claim 1, wherein the second end of the rotating shaft is provided with a groove, the bottom of the groove is a plane and passes through the axis of the rotating shaft, and the second inclination angle measurement device is fixed in the groove.

9. The engine camshaft timing angle measurement device of claim 1, wherein the second inclination angle measurement device is a capacitive acceleration sensor.

10. An engine timing angle measurement system, comprising: the engine camshaft timing angle measurement device, and the engine crankshaft timing angle measurement device according to any one of claims 1 to 9, wherein: the engine crankshaft timing measurement apparatus includes:

the rotating shaft bracket is provided with a cylinder body reference position positioning hole and a crankshaft reference position positioning hole;

one end of the fixed part is fixedly connected with the engine crankshaft, and the other end of the fixed part is connected with the rotating shaft frame and can rotate relative to the rotating shaft frame;

the first inclination angle measuring device is fixed on the rotating shaft frame and is used for measuring the timing angle of the crankshaft of the engine after the upper dead center of one cylinder of the engine is determined through the cylinder body reference position positioning hole and the crankshaft reference position positioning hole;

The signal wheel positioning hole is arranged on the rotating shaft bracket.

11. The engine timing angle measurement system of claim 10, wherein the engine crankshaft timing measurement device further comprises:

The cylinder body reference position adapting pin is matched with the cylinder body reference position positioning hole;

and the crankshaft reference position adapting pin is matched with the crankshaft reference position positioning hole.

12. The engine timing angle measurement system of claim 10, wherein the signal wheel alignment hole is located between the cylinder block reference position alignment hole and the crankshaft reference position alignment hole.

13. The engine timing angle measurement system of claim 10, wherein the stationary portion is provided with a boss and the spindle carrier is provided with a recess for receiving the boss.

14. The engine timing angle measurement system of claim 10, wherein the pivot bracket is provided with a receiving portion for receiving the first inclination measuring device.

15. An engine timing angle measurement method, characterized by comprising:

Determining a cylinder top dead center of the engine;

acquiring an absolute position of an engine camshaft using the engine camshaft timing angle measurement device according to any one of claims 1 to 9;

an engine timing angle is calculated based on the obtained absolute position of the engine camshaft and the absolute position of the engine crankshaft.

16. The engine timing angle measurement method of claim 15, wherein said employing said engine camshaft timing angle measurement device to obtain an absolute position of an engine camshaft comprises:

Acquiring the engine camshaft timing offset angle from the second inclination measuring device;

And obtaining the absolute position of the cam shaft according to the deviation of the engine base, the rotation angle of the cam shaft, the installation deviation of the second inclination angle measuring device and the timing deviation angle of the cam shaft of the engine.

17. The engine timing angle measurement method according to claim 16, wherein when the engine camshaft is a double overhead camshaft, the obtaining the absolute position of the engine camshaft includes:

A third inclination angle measuring device and a fourth inclination angle measuring device are respectively arranged on the air inlet camshaft and the air outlet camshaft, the timing deviation angle of the air inlet camshaft is obtained from the third inclination angle measuring device, and the timing deviation angle of the air outlet camshaft is obtained from the fourth inclination angle measuring device;

obtaining the absolute position of the air inlet cam shaft according to the deviation of the engine base, the cam shaft rotation angle, the installation deviation of the third inclination angle measuring device and the timing deviation angle of the air inlet cam shaft;

and obtaining the absolute position of the exhaust camshaft according to the deviation of the engine base, the rotation angle of the camshaft, the installation deviation of the fourth inclination angle measuring device and the timing deviation angle of the intake camshaft.

18. The engine timing angle measurement method of claim 17, wherein said determining engine cylinder top dead center comprises:

Mounting an engine crankshaft timing angle measurement device to an engine crankshaft, wherein the engine crankshaft timing angle measurement device comprises: the pivot frame, fixed part, first inclination measuring device, wherein: the rotating shaft frame is provided with a cylinder body reference position positioning hole and a crankshaft reference position positioning hole;

One end of the fixing part is fixedly connected with the engine crankshaft, and the other end of the fixing part is connected with the rotating shaft frame and can rotate relative to the rotating shaft frame;

The first inclination angle measuring device is fixed on the rotating shaft bracket and is used for measuring the timing angle of the engine crankshaft;

taking an absolute horizontal line as a zero deviation position, positioning a crankshaft mechanical timing position to a reference position, rotating the rotating shaft frame to a first position, determining an engine timing reference position by adopting the cylinder body reference position positioning hole, and reading a first angle displayed by the first inclination angle measuring device;

Rotating the rotating shaft frame to a second position, determining a crankshaft timing reference position by adopting the crankshaft reference position positioning hole, and reading a second angle displayed by the first inclination angle measuring device;

determining the top dead center position of a cylinder of the engine according to the first angle and the second angle;

wherein, the engine crankshaft timing angle measuring device further includes: the cylinder body reference position adapting pin is matched with the cylinder body reference position positioning hole; a crankshaft reference position adapting pin matched with the crankshaft reference position positioning hole;

After the engine crankshaft timing angle measuring device is fixed at the rear end of the crankshaft, the rotating shaft frame is rotated, when the cylinder body reference position positioning hole is opposite to the machining positioning reference hole of the engine cylinder body, the cylinder body reference position adapting pin is inserted into the cylinder body reference position positioning hole and stays for a period of time, the first inclination angle measuring device obtains the first angle, the position of the rotating shaft frame is the first position when the first angle is obtained, the cylinder body reference position adapting pin is taken out, the rotating shaft frame is continuously rotated, when the crankshaft reference position positioning hole is opposite to the third non-equidistant hole of the rear end of the crankshaft, the crankshaft reference position adapting pin is inserted, and stays for a period of time, and the first inclination angle measuring device obtains the second angle, so that the position of the rotating shaft frame is the second position when the second angle is obtained.

19. The engine timing angle measurement method according to claim 18, wherein the first inclination angle measurement device, the second inclination angle measurement device, the third inclination angle measurement device, and the fourth inclination angle measurement device are all capacitive acceleration sensors.

20. The engine timing angle measurement method of claim 19, wherein the deriving the engine timing angle from the obtained absolute position of the engine camshaft and the absolute position of the engine crankshaft comprises:

The engine timing angle deviation alpha is calculated by adopting the following formula:

F＝ma；

C＝ε·S/x；

F＝-kx；

Ax＝gsinα,Ay＝gcosα；

Wherein Ax is a measured value of acceleration in the x-axis direction, ay is a measured value of acceleration in the y-axis direction, az is a measured value of acceleration in the z-axis direction, charge between C electrodes, k is a stiffness coefficient, m is a mass of a mass block, x is displacement, F is force applied to the displacement x, G is gravitational acceleration, G is gravity, alpha is engine timing angle deviation, a is acceleration applied to a capacitive acceleration sensor, alpha _x is an included angle between Ax and gravity G, alpha _y is an included angle between Ay and gravity G, alpha _z is an included angle between Az and gravity G, epsilon is a dielectric constant of a medium between capacitive plates, and S is an area of a capacitive plate.

21. The engine timing angle measurement method according to claim 18, characterized by further comprising:

And rotating the rotating shaft frame to the reference position of the signal wheel to obtain the angle deviation between the timing position of the crankshaft of the engine and the signal wheel.