METHOD AND DEVICE FOR PHASE DIAGNOSIS

Abstract

Procedures for phase diagnosis, comprehensive: Performing an injection using an injector at top dead center of a compression stroke, when it is recognized that an engine position is valid, Detect (202) whether an engine is accelerating, based on a crankshaft signal detected by a crankshaft position sensor; Performing (203) an injection by means of the injector at the top dead center of an exhaust stroke when no acceleration is detected; Detect (204) whether the engine is accelerating, based on the crankshaft signal detected by the crankshaft position sensor, and; Detecting a camshaft phase deviation of 180 degrees based on a camshaft signal from a camshaft position sensor and the crankshaft signal detected by the crankshaft position sensor when acceleration is detected. including injection at top dead center of the exhaust stroke and detection of whether the engine is accelerating: the injection at the top dead center of the exhaust stroke; Detect whether the engine is accelerating; Detect (205) whether a preset number of injections has been reached when no acceleration is detected; Return to step (203) Performing an injection by means of the injector to top dead center of the exhaust stroke if the preset number of injections has not been reached; Terminate (206) injection when acceleration is detected or the injector reaches the preset number of injections.

Description

TECHNICAL AREA

[0001] The present application relates to the technical field of fault diagnosis, in particular to a method for phase diagnosis and a device for phase diagnosis. BACKGROUND

[0002] A camshaft is an important component of a piston engine, used to control the opening and closing of a valve.

[0003] If a camshaft has a phase deviation of 180 degrees, for example, a camshaft signal plate with a 180-degree deviation is installed. Or the camshaft signal plate is installed normally, but the camshaft's angular calibration deviation is 180 degrees, and camshaft phase deviation can occur, causing improper engine operation.

[0004] However, a camshaft phase deviation of 180 degrees cannot be detected using conventional technology. US 2007 / 0 277 776 A1 discloses a method for starting a direct-injection engine. The method can perform multiple fuel injections to start the engine, even if the absolute position of each piston is unknown. US 7 017 548 B2 discloses an engine control unit. The ignition timing is changed in the direction of advance or retardation, using a value obtained by multiplying the integration value of the engine speed difference by a gain factor as the ignition timing change amount. US 2005 / 0 021 220 A1 discloses an engine control unit in which an acceleration state is detected as quickly as possible during engine start-up. SUMMARY

[0005] In light of this, the present application aims to provide a method and a device for phase diagnosis in order to solve the problem that a camshaft phase deviation of 180 degrees cannot be detected using conventional techniques. This objective is achieved by the subject matter with the features of the independent claims. Advantageous embodiments of the invention are described in the dependent claims.

[0006] The present application provides a method for phase diagnosis, which includes the following: an injector that injects at top dead center (TDC) of a compression stroke when a valid engine position is detected; Detecting whether an engine is accelerating; The injector performs the injection at the top dead center of an exhaust stroke if no acceleration is detected; Detect whether the engine is accelerating; Displays the camshaft phase deviation of 180 degrees when acceleration is detected.

[0007] Optionally, the procedure also includes comprehensively determining whether the engine position is valid: Acquiring a crankshaft signal from a crankshaft position sensor and a camshaft signal from a camshaft position sensor; Determine whether the engine position is valid according to the crankshaft signal and the camshaft signal.

[0008] Optionally, the procedure also includes triggering an alarm if a camshaft phase deviation of 180 degrees is detected.

[0009] The injector injects at top dead center of an exhaust stroke to determine if acceleration is occurring, including: Performing an injection via the injector at the top dead center of the exhaust stroke; Detect whether the engine is accelerating; If no acceleration is detected, determine whether the preset number of injections has been reached; If the preset number of injections is not reached, return to the step of performing an injection using the injector at top dead center of the exhaust stroke; Stop injection when acceleration is detected or the injector has reached the preset number of injections.

[0010] Optionally, the preset detection conditions include: whether a water temperature meets a preset water temperature condition, and whether the suction pressure meets the preset suction pressure condition.

[0011] A phase diagnosis device is provided by an embodiment of the present application, comprising: a first injector unit, designed to control an injector so that it performs the injection at a top dead center of an exhaust stroke when a valid engine position is detected; a first detection unit, designed to detect whether a motor is accelerating; a second injector and detection unit, designed to control the injector so that it performs the injection at the top dead center of the exhaust stroke and detects whether the engine is accelerating; a deviation detection unit designed to indicate that the camshaft phase deviates by 180 degrees when acceleration is detected.

[0012] Optionally, the device also includes: a detection unit designed to detect a crankshaft signal from a crankshaft position sensor and a camshaft signal from a camshaft position sensor; a first determination unit, designed to determine whether the engine position is valid according to the crankshaft signal and the camshaft signal.

[0013] The device also includes: an alarm unit that triggers when a camshaft phase deviation of 180 degrees is detected.

[0014] Optionally, the device also includes: a second injector sub-unit, designed to control an injector so that it performs the injection at the top dead center of a compression stroke; a second detection sub-unit, designed to detect whether the engine is accelerating; a third detection subunit, designed to detect whether the preset number of injections has been reached when no acceleration is detected; a repetition unit designed to return to perform an injection by means of the injector at the top dead center of the exhaust stroke if the preset number of injections has not been reached; an injection terminal unit designed to stop injection when acceleration is detected or the injector has reached the preset number of injections.

[0015] Optionally, preset detection conditions can include: whether a water temperature meets a preset water temperature condition, and whether a suction pressure meets a preset suction pressure condition.

[0016] The embodiment provided by the present application provides a method and a device for phase diagnosis. After verifying that the engine position is valid, an injector performs an injection at top dead center of the compression stroke. If no acceleration is detected after the injection, this indicates that a fault has occurred. To detect whether the fault is a camshaft phase deviation of 180 degrees, the injector performs an injection at top dead center of the exhaust stroke, and the presence of acceleration is detected. If acceleration is detected, this indicates that the camshaft phase deviation of 180 degrees is present. In this way, the problem of the prior art, namely that the phase deviation cannot be detected when the camshaft phase deviates by 180 degrees, is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] To better illustrate embodiments of the present application or the technical solutions in conventional technology, the drawings used in describing the embodiments or the conventional technology are briefly described below. Obviously, the drawings in the following description represent only some embodiments of the present application. A person skilled in the art can create other drawings based on the provided drawings without any creative effort. Fig. Figure 1 shows a schematic flowchart of a phase diagnosis method provided by an embodiment of the present application; Fig. Figure 2 shows a schematic flowchart of a phase diagnosis method provided by another embodiment of the present application; Fig. Figure 3 shows a schematic structure diagram of a phase diagnostic device provided by the embodiment of the present application. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0018] The following description of the preferred embodiment is only exemplary and in no way constitutes a limitation of the present application and its application or use.

[0019] Referring to Fig. Figure 1 shows a schematic flowchart of a phase diagnosis method provided by an embodiment of the present application. In this embodiment, the method comprises: S101: When it is detected that an engine position is valid, an injector performs injection at top dead center of a compression stroke; For engine control, it is important to find a mechanical position of the engine that can be used to determine the top dead center of a piston in order to perform precise injection. In this embodiment, the engine position is determined by a crankshaft signal and a camshaft signal, which are detected by a crankshaft sensor and a camshaft sensor, respectively.

[0020] The crankshaft signal detected by the crankshaft position sensor can be used to determine the engine's rotational position, and the camshaft position signal detected by the camshaft position sensor can be used to determine the top dead center (TDC) of the compression stroke and the exhaust stroke. Once these positions are confirmed, the engine position is correct, and fuel injection can be performed at TDC of the compression stroke.

[0021] S102: Determine whether the engine accelerates or not.

[0022] In this configuration, the engine can accelerate after injection under normal circumstances. If there is no acceleration, it means the engine is malfunctioning. However, there are many faults that can cause a lack of acceleration after injector injection. But technicians usually overlook the case where the camshaft phase is off by 180 degrees (that is, the detected camshaft phase deviation is 180 degrees).

[0023] The case where the camshaft phase deviates by 180 degrees cannot be verified with conventional technology.

[0024] To solve the problems mentioned above, the following steps are used to check whether the camshaft phase deviates by 180 degrees or not.

[0025] S103: If no acceleration is detected, the injector performs the injection at TDC of the exhaust stroke.

[0026] If the camshaft phase deviates by 180 degrees, the determined TDC of the compression stroke and the TDC of the exhaust stroke of the engine are reversed, that is, the determined TDC of the compression stroke is in reality the determined TDC of the exhaust stroke, and the determined TDC of the exhaust stroke is in reality the TDC of the compression stroke.

[0027] However, in conventional technology, when detecting the valid engine position, the camshaft phase deviates by 360 degrees relative to the crankshaft if a camshaft signal plate is installed incorrectly by 180 degrees. Given that the camshaft signal plate is correctly installed, let the crankshaft phase angle at detection point a be and the camshaft phase angle at detection point b be . In a case where the camshaft signal plate is installed incorrectly by 180 degrees, when the crankshaft rotates 360 degrees and the camshaft rotates 180 degrees, then at detection point a the crankshaft phase angle is still a and the camshaft phase angle is still b.This means that if, with conventional technology, the camshaft signal plate is installed 180 degrees backwards or the phase calibration deviates by 180 degrees, the deviation cannot be detected.

[0028] In this embodiment, to detect whether the camshaft deviation is 180 degrees or not, after the injector performs the injection at TDC of the compression stroke, if no acceleration is detected, the injection is performed at a reversed position of TDC of the compression stroke. The reversed position of TDC of the compression stroke is TDC of the exhaust stroke.

[0029] S104: Detect whether the engine is accelerating or not;

[0030] S105: When an acceleration is detected that indicates a camshaft phase deviation of 180 degrees.

[0031] If, in this embodiment, no acceleration is detected after the injector performs the injection at top dead center (TDC) of the exhaust stroke, this means that there is no malfunction in the form of a camshaft phase deviation of 180 degrees. However, if acceleration is detected, this means that the camshaft phase is off by 180 degrees.

[0032] In this embodiment, once the engine position is confirmed to be correct, the injector performs the injection at top dead center (TDC) of the compression stroke. If no acceleration is detected after injection, this indicates a malfunction. To determine whether the malfunction is a camshaft phase deviation of 180 degrees, the injector performs the injection at TDC of the exhaust stroke and detects whether acceleration occurs. If acceleration is detected, this indicates a 180-degree camshaft phase deviation. This solves the problem of conventional technology, where the phase deviation cannot be detected when the camshaft phase is off by 180 degrees.

[0033] With reference to Fig. Figure 2 shows a schematic flowchart of a phase diagnosis method which is provided for in another embodiment of the present application.

[0034] To improve the effectiveness of detecting whether the camshaft phase deviation is 180 degrees, the number of injections can be adjusted. For example, the number of injections can be a minimum of one, and the specific number can be set according to the actual situation. The procedure includes: S201: When it is detected that an engine position is valid, an injector performs the injection at TDC of a compression stroke; S202: Detects whether an engine is accelerating; S203: if no acceleration is detected, the injector performs the injection at TDC of an exhaust stroke; S204: Detect whether the engine is accelerating; S205: If no acceleration is detected, detect whether a preset number of injections has been reached; S206: If the preset number of injections is not reached, the injector performs the injection again at TDC of the exhaust stroke and returns to executing the detection of whether acceleration is detected; S207: If acceleration is detected or the injector reaches the preset number of injections, injection is stopped.

[0035] In this embodiment, once the engine position is confirmed to be correct, the injector performs the injection at top dead center (TDC) of the compression stroke. If no acceleration is detected after injection, this indicates a malfunction. To determine whether the malfunction is due to a 180-degree camshaft phase deviation, the injector performs the injection at TDC of the exhaust stroke and detects whether acceleration occurs. If acceleration is detected, this indicates a 180-degree camshaft phase deviation. This solves the problem in conventional technology where the phase deviation cannot be detected when the camshaft phase is off by 180 degrees.

[0036] Referring to Fig.Figure 3 shows a schematic structure diagram of a phase diagnostic device provided by an embodiment of the present application. In this embodiment, the device comprises: a first injector unit 301, designed to control an injector so that it performs the injection at TDC of a compression stroke when a valid engine position is detected; a first detection unit 302, designed to detect whether a motor is accelerating or not; a second injector unit 303, designed to control the injector so that it performs the injection at TDC of an exhaust stroke when acceleration is detected; a second detection unit, designed to detect whether the engine is accelerating or not; a deviation determination unit 304, designed to indicate that the camshaft phase deviates by 180 degrees when acceleration is detected.

[0037] Optionally, the device also includes: an alarm unit designed to be triggered when a camshaft phase deviation of 180 degrees is detected.

[0038] Alternatively, the second unit of determination may also include: a second detection subunit, designed to detect whether the engine is accelerating or not, after the injector has first performed the injection at TDC of the exhaust stroke; a third detection subunit, designed to detect whether a preset number of injections has been reached when no acceleration is detected; an execution repeat unit designed to return to perform an injection by means of the injector at top dead center of the exhaust stroke if the preset number of injections is not reached, and to execute in order to detect whether the engine is accelerating or not; an injection terminal unit designed to terminate injection when acceleration is detected or the injector reaches the preset number of injections.

[0039] Optionally, the preset detection conditions include: whether a water temperature meets a preset water temperature condition, and whether a suction pressure meets a preset suction pressure condition.

[0040] In this embodiment, once the engine position is verified to be correct, the injector performs the injection at top dead center (TDC) of the compression stroke. If no acceleration is detected after injection, this indicates a malfunction. To detect whether the malfunction is in the form of a 180-degree camshaft phase deviation, the injector performs the injection at TDC of the exhaust stroke and detects whether acceleration occurs. If acceleration is detected, this indicates a 180-degree camshaft phase deviation. This solves the problem of conventional technology, where the phase deviation cannot be detected if the camshaft phase is off by 180 degrees.

[0041] The above embodiments are described step by step. Each embodiment focuses primarily on describing its differences from other embodiments, and reference may be made between these embodiments with respect to identical or similar parts.

[0042] The above description of the disclosed embodiments should enable a person skilled in the art to implement or use the present application. Various modifications to the embodiments are obvious to a person skilled in the art, and the general principle contained herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments described herein but should be in accordance with the broadest possible scope of application compatible with the principle disclosed herein and the novel features.

Claims

[1] Phase diagnosis procedures, including: Performing an injection using an injector at top dead center of a compression stroke, when it is recognized that an engine position is valid, Detect (202) whether an engine is accelerating, based on a crankshaft signal detected by a crankshaft position sensor; Performing (203) an injection by means of the injector at the top dead center of an exhaust stroke when no acceleration is detected; Detect (204) whether the engine is accelerating, based on the crankshaft signal detected by the crankshaft position sensor, and; Detecting a camshaft phase deviation of 180 degrees based on a camshaft signal from a camshaft position sensor and the crankshaft signal detected by the crankshaft position sensor when acceleration is detected. including injection at top dead center of the exhaust stroke and detection of whether the engine is accelerating: the injection at the top dead center of the exhaust stroke; Detect whether the engine is accelerating; Detect (205) whether a preset number of injections has been reached when no acceleration is detected; Return to step (203) Performing an injection by means of the injector to top dead center of the exhaust stroke if the preset number of injections has not been reached; Terminate (206) injection when acceleration is detected or the injector reaches the preset number of injections. [2] Method according to claim 1, wherein the detection of whether the motor position is valid comprises: Capturing the crankshaft signal from the crankshaft position sensor and the camshaft signal from the camshaft position sensor; Determine whether the engine position is valid according to the crankshaft signal and the camshaft signal. [3] Method according to claim 1, further comprising: Alarm triggered when a camshaft phase deviation of 180 degrees is detected. [4] Method according to claim 1, wherein preset detection conditions comprise: whether a water temperature meets a preset water temperature condition, and whether a suction pressure meets a preset suction pressure condition. [5] Phase diagnosis device, comprising: a first injector unit (301) configured to control an injector such that it performs the injection at a top dead center of an exhaust stroke when a valid engine position is detected; a first detection unit (302) designed to detect whether a motor is accelerating; a second injector and detection unit (303) designed to control the injector so that it performs the injection at the top dead center of the exhaust stroke and to detect whether the engine is accelerating; a deviation determination unit (304) configured to indicate that the camshaft phase is off by 180 degrees, based on a camshaft signal from a camshaft position sensor and the crankshaft signal detected by the crankshaft position sensor when acceleration is detected, and an alarm unit that triggers when a camshaft phase deviation of 180 degrees is detected. [6] Phase diagnosis device according to claim 5, further comprising: a detection unit designed to detect the crankshaft signal from the crankshaft position sensor and the camshaft signal from the camshaft position sensor; a first determination unit, designed to determine whether the engine position is valid according to the crankshaft signal and the camshaft signal. [7] Phase diagnosis device according to claim 5, comprising: a second injector sub-unit, designed to control an injector so that it performs the injection at the top dead center of a compression stroke; a second detection sub-unit, designed to detect whether the engine is accelerating; a third detection subunit, designed to detect whether a preset number of injections has been reached when no acceleration is detected; a repetition unit designed to return to perform an injection by means of the injector at the top dead center of the exhaust stroke if the preset number of injections has not been reached; an injection terminal unit designed to stop injection when acceleration is detected or the injector has reached the preset number of injections. [8] Phase diagnosis device according to claim 5, wherein preset detection conditions comprise: whether a water temperature meets a preset water temperature condition, and whether a suction pressure meets a preset suction pressure condition.

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