A method for correcting engine camshaft deviation

Abstract

The present invention relates to the field of engine technology, and discloses a method for correcting an engine camshaft deviation. When detecting and correcting the camshaft deviation, the engine is first adjusted to a first operating condition. If the actual air intake under the first operating condition is equal to the calibrated air intake, the actual air volume of the throttle under the second operating condition and the third operating condition is obtained respectively, and the air volume deviation is calculated. Then, a relationship between the air volume deviation and the camshaft phase deviation is established, and the corresponding camshaft phase deviation is obtained according to the relationship. Finally, the camshaft phase deviation is applied to the physical position of the camshaft to correct the movement of the camshaft. The present invention can detect and correct the camshaft of the engine at the stage of the vehicle being off the assembly line, which is efficient and convenient, and does not increase the hardware cost, thereby ensuring the design goal of the vehicle. The present invention can also detect and correct the camshaft deviation during the later maintenance of the vehicle, providing an effective method and measure for vehicle maintenance.

Description

Technical Field

[0001] The invention relates to the technical field of engines, and in particular to a method for correcting engine camshaft deviation. Background Art

[0002] The camshaft is a component in a piston engine that controls the opening and closing of the valves. The response of the internal combustion engine to changes in the required engine power or required torque can be improved by means of dynamic control of the camshaft phase.

[0003] The installation accuracy of the camshaft is an important factor affecting the intake accuracy of the automobile engine. The installation deviation of the camshaft is very difficult to measure. If the deviation is too large, it will lead to intake deviation, which will have a direct impact on engine performance, fuel consumption and emissions. In addition, with the increase of usage time and load, the chain between the crankshaft and the camshaft will gradually be stretched, resulting in an increase in the camshaft phase deviation. When it increases to a certain limit, it will cause the engine to fail and become unusable.

[0004] Therefore, how to detect and correct camshaft deviation plays an important role in vehicle design and subsequent vehicle maintenance. Summary of the invention

[0005] Based on the above problems, the purpose of the present invention is to provide an engine camshaft deviation correction method, which can inspect and correct the camshaft of the engine, is efficient and convenient, ensures the design goals of the whole vehicle, and facilitates the later maintenance of the vehicle's camshaft deviation.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for correcting engine camshaft deviation comprises the following steps:

[0008] Adjust the engine to idle speed;

[0009] In an idle state, the engine is adjusted to a first operating condition, a second operating condition, and a third operating condition respectively;

[0010] obtaining a calibrated air intake amount and an actual air intake amount of a throttle valve of the engine under the first working condition, and determining whether the actual air intake amount is equal to the calibrated air intake amount;

[0011] If yes, respectively obtain the actual ventilation volume and the calibrated ventilation volume of the throttle under the second working condition and the third working condition, and calculate the ventilation volume deviation between the actual ventilation volume and the corresponding calibrated ventilation volume;

[0012] Establishing a relationship between the ventilation volume deviation and the camshaft phase deviation of the camshaft, and obtaining the camshaft phase deviation according to the relationship;

[0013] The camshaft phase deviation is applied to the physical position of the camshaft to correct the motion of the camshaft.

[0014] As a preferred embodiment of the engine camshaft deviation correction method of the present invention, the first operating condition is the intake amount stabilization point of the throttle valve, the second operating condition is the intake sensitive point of the throttle valve, and the third operating condition is the exhaust sensitive point of the throttle valve.

[0015] As a preferred embodiment of the engine camshaft deviation correction method of the present invention, when the camshaft is in the first working condition, Ps / Psv≤0.528, wherein Ps is the intake pressure of the throttle valve, and Psv is the exhaust pressure of the throttle valve.

[0016] As a preferred embodiment of the engine camshaft deviation correction method of the present invention, when the camshaft is in the second working condition and the third working condition, the phase of the camshaft satisfies Formula 1, which is:

[0017] InF=InF(IVC), wherein IVC represents the phase of the camshaft.

[0018] As a preferred embodiment of the engine camshaft deviation correction method of the present invention, the relationship between the camshaft phase deviation and the ventilation volume deviation includes Formula 2 and Formula 3;

[0019] The formula 2 is:

[0020] Δrl=ΔInF*Ps, where Ps is the intake pressure of the throttle valve, Δrl=r-r0, r is the actual ventilation volume, r0 is the calibrated ventilation volume, and Δrl is the ventilation volume deviation;

[0021] The formula three is:

[0022] Wherein, ΔIVC is the camshaft phase deviation, It is obtained by the formula 1, and ΔInF is obtained by the formula 2.

[0023] As a preferred embodiment of the engine camshaft deviation correction method of the present invention, the actual phase of the camshaft and the calibrated phase of the camshaft satisfy Formula 4, which is:

[0024] IVC Act =IVC S +ΔIVC;

[0025] Among them, IVC Act is the actual phase of the camshaft, IVC S is the calibrated phase of the camshaft, and ΔIVC is obtained by formula three.

[0026] As a preferred embodiment of the engine camshaft deviation correction method of the present invention, when the camshaft is in the second operating condition, the actual ventilation volume is the actual intake volume of the throttle valve, the camshaft phase deviation is the intake camshaft phase deviation, and the actual intake volume is related to the intake camshaft phase deviation.

[0027] As a preferred embodiment of the engine camshaft deviation correction method of the present invention, when the camshaft is in the third working condition, the actual ventilation volume is the actual exhaust volume of the throttle valve, the camshaft phase deviation is the exhaust camshaft phase deviation, and the actual exhaust volume is related to the exhaust camshaft phase deviation.

[0028] As a preferred embodiment of the engine camshaft deviation correction method of the present invention, when the camshaft is in the first operating condition, if the actual intake volume is not equal to the calibrated intake volume, correction of the camshaft is stopped.

[0029] As a preferred embodiment of the engine camshaft deviation correction method of the present invention, the first operating condition, the second operating condition and the third operating condition are all obtained by adjusting the air flow of the throttle valve and the ignition angle of the engine.

[0030] The beneficial effects of the present invention are:

[0031] The engine camshaft deviation correction method provided by the present invention, when detecting and correcting the camshaft deviation, first adjusts the engine to an idle state, and adjusts the engine to a first working condition, and measures and obtains the actual intake volume of the throttle under the first working condition. If the actual intake volume is equal to the calibrated intake volume of the engine under the first working condition, it indicates that the camshaft deviation correction can be performed. Specifically, the actual ventilation volume of the throttle under the second working condition and the third working condition is obtained respectively, and the ventilation volume deviation is obtained by subtracting the actual ventilation volume from the calibrated ventilation volume under the corresponding working condition. Then, a relationship between the ventilation volume deviation and the camshaft phase deviation is established, and the camshaft phase deviation under the corresponding working condition is obtained according to the relationship. Finally, the obtained camshaft phase deviation is applied to the physical position of the camshaft to correct the movement of the camshaft. The present invention can detect and correct the camshaft of the engine at the stage of the vehicle going offline, which is efficient and convenient, accurate in detection, and does not increase the hardware cost, thereby ensuring the design goal of the vehicle. At the same time, the present invention can also detect and correct the camshaft deviation during the later maintenance of the vehicle, providing an effective method and measure for vehicle maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0033] Figure 1 is a flow chart of an engine camshaft deviation correction method provided by a specific embodiment of the present invention;

[0034] Figure 2 is a curve diagram showing the relationship between the air intake volume and the pressure ratio of the throttle provided in a specific embodiment of the present invention;

[0035] Figure 3 It is a curve diagram of Formula 1 provided in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0037] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] like Figure 1As shown, this embodiment provides a method for correcting engine camshaft deviation, which specifically includes the following steps:

[0040] S1. Adjust the engine to idle state;

[0041] S2, adjusting the engine to the first operating condition, the second operating condition and the third operating condition respectively in the idle state;

[0042] S3, obtaining a calibrated air intake volume and an actual air intake volume of a throttle valve of the engine under the first working condition, and determining whether the actual air intake volume is equal to the calibrated air intake volume;

[0043] If yes, go to S4;

[0044] S4, respectively obtaining the actual ventilation volume and the calibrated ventilation volume of the throttle valve under the second working condition and the third working condition, and calculating the ventilation volume deviation between the actual ventilation volume and the corresponding calibrated ventilation volume;

[0045] S5, establishing a relationship between the ventilation volume deviation and the camshaft phase deviation of the camshaft, and obtaining the camshaft phase deviation according to the relationship;

[0046] S6. Apply the camshaft phase deviation to the physical position of the camshaft to correct the movement of the camshaft.

[0047] In step S3, if the actual intake air amount is not equal to the calibrated intake air amount, the camshaft correction is stopped.

[0048] The engine camshaft deviation correction method provided in this embodiment, when detecting and correcting the camshaft deviation, first adjusts the engine to the idle state, and adjusts the engine to the first working condition, and measures the actual intake volume of the throttle under the first working condition. If the actual intake volume is equal to the calibrated intake volume of the engine under the first working condition, it indicates that the camshaft deviation correction can be performed. Specifically, the actual ventilation volume of the throttle under the second working condition and the third working condition is obtained respectively, and the ventilation volume deviation is obtained by subtracting the actual ventilation volume from the calibrated ventilation volume under the corresponding working condition. Then, a relationship between the ventilation volume deviation and the camshaft phase deviation is established, and the camshaft phase deviation under the corresponding working condition is obtained according to the relationship. Finally, the obtained camshaft phase deviation is applied to the physical position of the camshaft to correct the movement of the camshaft. This method can detect and correct the camshaft of the engine at the stage of the vehicle being off the assembly line, which is efficient and convenient, accurate in detection, and does not increase the hardware cost, thereby ensuring the design goal of the vehicle. At the same time, this method can also detect and correct the camshaft deviation during the later maintenance of the vehicle, providing an effective method and measure for vehicle maintenance.

[0049] In step S2, the first operating condition is the intake amount stable point of the throttle valve, the second operating condition is the intake sensitive point of the throttle valve, and the third operating condition is the exhaust sensitive point of the throttle valve.

[0050] In this embodiment, the first working condition, the second working condition and the third working condition are all obtained by adjusting the ventilation volume of the throttle valve and the ignition angle of the engine. That is, each working condition needs to meet the requirements of the intake (exhaust) flow rate and intake (exhaust) pressure stability of the throttle valve. If the requirements are not met, the ventilation volume and ignition angle of the throttle valve need to be readjusted until the requirements of each working condition are met. For the second working condition, the ventilation volume of the throttle valve is the intake volume, and for the third working condition, the ventilation volume of the throttle valve is the exhaust volume.

[0051] In step S3, when the camshaft is in the first working condition, Ps / Psv≤0.528, where Ps is the intake pressure of the throttle valve and Psv is the exhaust pressure of the throttle valve. Figure 2 In the figure, the horizontal axis is Ps / Psv, and the vertical axis is the mass flow ratio (the ratio of flow velocity to sound speed). In the first working condition, the value of Ps / Psv is artificially controlled to make Ps / Psv≤0.528. Since the flow velocity is equal to the sound speed at this time, the actual intake flow of the throttle is only related to the throttle opening, and it is not affected by the camshaft phase deviation. Therefore, if the actual intake volume of the throttle under the first working condition is equal to the calibrated intake volume, it proves that only the deviation of the camshaft affects the intake volume of the throttle, and the camshaft can be corrected by the camshaft phase deviation. If the actual intake volume of the throttle under the first working condition is not equal to the calibrated intake volume, it means that there are other factors affecting the throttle intake volume of the engine, so the camshaft cannot be corrected by the camshaft phase deviation.

[0052] In step S4 and step S5, when the camshaft is in the second working condition and the third working condition, the phase of the camshaft satisfies formula 1, which is:

[0053] InF=InF(IVC), wherein IVC represents the phase of the camshaft and InF is an introduced intermediate variable.

[0054] like Figure 3 As shown, the relationship curve of formula one is given.

[0055] Furthermore, the relationship between the camshaft phase deviation and the ventilation volume deviation includes formula 2 and formula 3;

[0056] Formula 2 is:

[0057] Δrl=ΔInF*Ps, where Ps is the intake pressure of the throttle, Δrl=r-r0, r is the actual ventilation volume, r0 is the calibrated ventilation volume, and Δrl is the ventilation volume deviation;

[0058] Formula three is:

[0059] Where, ΔIVC is the camshaft phase deviation, It is obtained by formula 1, and ΔInF is obtained by formula 2.

[0060] In formula 2, the actual ventilation volume r of the throttle can be obtained by measurement, and the calibrated ventilation volume r0 of the throttle is a known value (the value of r0 is different under different working conditions). The ventilation volume deviation can be calculated by Δrl=r-r0, and the intake pressure Ps of the throttle can be measured by a sensor and is also a known value. Therefore, ΔInF can be obtained by formula 2.

[0061] In formula 3, ΔInF has been calculated, and formula 1 is a known relationship curve. Formula 1 can be used to obtain (Under different working conditions The value of is different), so the camshaft phase deviation ΔIVC can be calculated according to formula 3.

[0062] In this embodiment, the actual phase of the camshaft and the calibrated phase of the camshaft satisfy Formula 4, which is:

[0063] IVC Act =IVC S +ΔIVC;

[0064] Among them, IVC Act is the actual phase of the camshaft, IVC S is the calibrated phase of the camshaft (a known value, different calibrated phases correspond to different working conditions), and ΔIVC is obtained by formula 3.

[0065] like Figure 3 As shown, different ΔInF corresponds to different Different ΔIVCs can be obtained. After the ΔIVC under the second working condition and the ΔIVC under the third working condition are calculated respectively, the actual phase IVC of the camshaft is calculated by formula 4. Act . IVC Act Applied to the physical position of the camshaft, the physical rotation amount of the camshaft includes the camshaft phase deviation value, thereby realizing the deviation correction of the camshaft.

[0066] In this embodiment, when the camshaft is in the second working condition, the actual air flow is the actual air flow of the throttle valve, the camshaft phase deviation is the intake camshaft phase deviation, the actual air flow is related to the intake camshaft phase deviation, the intake flow deviation is obtained according to the measured actual air flow and the known calibrated air flow under the second working condition, and then the intake camshaft phase deviation is obtained according to Formula 2 and Formula 3, and then the actual phase IVC of the camshaft under the second working condition is calculated. Act , in order to correct the deviation of the intake camshaft.

[0067] When the camshaft is in the third working condition, the actual ventilation volume is the actual exhaust volume of the throttle valve, and the camshaft phase deviation is the exhaust camshaft phase deviation. The actual exhaust volume is related to the exhaust camshaft phase deviation. The exhaust volume deviation is obtained according to the measured actual exhaust volume and the calibrated exhaust volume under the known third working condition, and then the exhaust camshaft phase deviation is obtained according to Formula 2 and Formula 3, and then the actual phase IVC of the camshaft under the third working condition is calculated. Act , in order to correct the deviation of the exhaust camshaft.

[0068] The engine camshaft deviation correction method provided in this embodiment can detect and correct the engine camshaft when the vehicle is off the production line, and can also detect and correct the camshaft deviation during the later maintenance of the vehicle. It is efficient and convenient, with accurate detection, and does not increase hardware costs.

[0069] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for correcting engine camshaft deviation, characterized in that: The following steps are involved: Adjust the engine to idle speed; In an idle state, the engine is adjusted to a first operating condition, a second operating condition, and a third operating condition respectively; obtaining a calibrated air intake amount and an actual air intake amount of a throttle valve of the engine under the first working condition, and determining whether the actual air intake amount is equal to the calibrated air intake amount; If yes, respectively obtain the actual ventilation volume and the calibrated ventilation volume of the throttle under the second working condition and the third working condition, and calculate the ventilation volume deviation between the actual ventilation volume and the corresponding calibrated ventilation volume; Establishing a relationship between the ventilation volume deviation and the camshaft phase deviation of the camshaft, and obtaining the camshaft phase deviation according to the relationship; applying the camshaft phase deviation to the physical position of the camshaft to correct the movement of the camshaft; When the camshaft is in the second working condition and the third working condition, the phase of the camshaft satisfies Formula 1, which is: InF=InF(IVC), wherein IVC represents the phase of the camshaft; The relationship between the camshaft phase deviation and the ventilation volume deviation includes formula 2 and formula 3; The formula 2 is: Δrl=ΔInF*Ps, where Ps is the intake pressure of the throttle valve, Δrl=r-r0, r is the actual ventilation volume, r0 is the calibrated ventilation volume, and Δrl is the ventilation volume deviation; The formula three is: Wherein, ΔIVC is the camshaft phase deviation, It is obtained by the formula 1, and ΔInF is obtained by the formula 2; The actual phase of the camshaft and the calibrated phase of the camshaft satisfy Formula 4, which is: IVC Act =IVC S +ΔIVC; Among them, IVC Act is the actual phase of the camshaft, IVC S is the calibrated phase of the camshaft, and ΔIVC is obtained by formula three.

2. The engine camshaft deviation correction method according to claim 1, characterized in that: The first operating condition is an intake amount stable point of the throttle valve, the second operating condition is an intake sensitive point of the throttle valve, and the third operating condition is an exhaust sensitive point of the throttle valve.

3. The engine camshaft deviation correction method according to claim 2, characterized in that: When the camshaft is in the first operating condition, Ps / Psv≤0.528, wherein Ps is the intake pressure of the throttle valve, and Psv is the exhaust pressure of the throttle valve.

4. The engine camshaft deviation correction method according to claim 2, characterized in that: When the camshaft is in the second working condition, the actual air flow is the actual air intake of the throttle valve, the camshaft phase deviation is the intake camshaft phase deviation, and the actual air intake is related to the intake camshaft phase deviation.

5. The engine camshaft deviation correction method according to claim 2, characterized in that: When the camshaft is in the third working condition, the actual ventilation volume is the actual exhaust volume of the throttle valve, the camshaft phase deviation is the exhaust camshaft phase deviation, and the actual exhaust volume is related to the exhaust camshaft phase deviation.

6. The engine camshaft deviation correction method according to claim 1, characterized in that: When the camshaft is in the first operating condition, if the actual intake amount is not equal to the calibrated intake amount, the correction of the camshaft is stopped.

7. The engine camshaft deviation correction method according to any one of claims 1 to 6, characterized in that: The first operating condition, the second operating condition and the third operating condition are all obtained by adjusting the air flow of the throttle valve and the ignition angle of the engine.

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