Method for measuring torsional vibration of phase wheel of camshaft of engine pedestal

Abstract

The invention discloses a method for measuring torsional vibration of a phase wheel of an engine pedestal camshaft and belongs to the field of engines. The method comprises the following steps that 1, after engine performance is preliminarily tested to be qualified, subsequent procedures are carried out; step 2, arranging an engine intake and exhaust system and a suspension, and referring to the state of the whole vehicle, installing the engine intake and exhaust system and the suspension on a tested engine pedestal; 3, a first wire harness of the engine is connected to a first ECU, a signal line of the Hall sensor is connected to a second wire harness, the second wire harness is connected to a second ECU, and it is checked that power supply transmission of the engine pedestal to the wire harnesses and the ECUs is normal; 4, connecting the BBM data acquisition system with a test computer through a network cable, and performing data acquisition by using PAK software; and 5, controlling test boundary conditions to meet test requirements. The measuring method can diagnose the spring fracture fault caused by the reduction of the engine oil pressure.

Description

Technical Field

[0001] The present invention belongs to the field of engines and relates to a method for measuring the torsional vibration of a camshaft phase wheel on an engine test bench. Background Art

[0002] At present, on an engine test bench, there is no effective technical means for measuring the torsional vibration of a camshaft. The camshaft phase wheel is located inside the engine, and testing methods such as laser and optoelectronic are not applicable to the actual test process. Moreover, there will be a certain deviation between the simulation calculation value and the actual situation, and there is currently no effective method for determination and evaluation tests. Summary of the Invention

[0003] The purpose of the present invention is to solve the above problems existing in the background art and provide a method for measuring the torsional vibration of a camshaft phase wheel on an engine test bench.

[0004] Since the phase wheel is integrated into the internal structure of the engine, it is difficult for traditional testing means to achieve torsional vibration measurement without disturbing the normal operation of the engine. The measurement method of the present invention, through designing a special fixing tooling and installation method, integrating and arranging Hall sensors, and adopting a dual-ECU power supply system to solve the sensor power supply problem, realizes the accurate measurement of the torsional vibration of the camshaft phase wheel and the dynamic characteristic analysis through test data acquisition and calculation analysis.

[0005] The present invention adopts the following technical solutions to achieve the above purpose: A method for measuring the torsional vibration of a camshaft phase wheel on an engine test bench, comprising the following steps: Step 1: After the engine passes the initial performance test, perform subsequent processes, that is, remove the timing chain cover of the engine, install the Hall sensor on the special tooling, then fix the tooling to the cylinder head inside the engine and ensure that the front end of the Hall sensor is perpendicular to the camshaft phase wheel, lead out the signal wire of the Hall sensor from the front end of the cover, and then restore the engine; Step 2: Install the engine, the engine intake and exhaust systems and the mounts on the test engine test bench with reference to the vehicle state; Step 3: Connect the test harness one of the engine to ECU one, connect the three signal wires of the Hall sensor to the Hall sensor measurement position of the harness two, and then connect the harness two to ECU two, and check to ensure that the power supply transmission of the test engine test bench to the two sets of the harnesses and ECU one (1) and ECU (2) is normal; Use a signal wire with a single-ended BNC connector to connect the three signal wires of the Hall sensor and connect them to PAKMobile MKII, so that the harness two and PAK Mobile MKII are in a parallel state; Step 4: Before officially entering the test, connect the front end of the BBM data acquisition system to the test computer via an Ethernet cable and use the PAK software for data acquisition. Check the engine status. After confirming no abnormalities, connect INCA to warm up the engine. Step 5: Control the test boundary conditions to meet the test requirements; when reaching the test condition, operate PAK and use PAK Mobile MKII to collect the rotational speed signal of the camshaft phaser measured by the Hall sensor. Step 6: Use PAK to calculate the time-domain rotational speed data of the Hall sensor, calculate the root mean square value (RSM) using PAK, output its time-domain raw data, and analyze the data results, that is, compare the data in the original state and the data after adjusting the oil pressure under the same working condition; if the amplitude of the torsional angular velocity of the camshaft phaser is more than twice the amplitude in the original state after adjusting the oil pressure, it can be determined that the abnormal operation of the engine's camshaft is caused by the reduction of the oil pressure under this working condition.

[0006] Furthermore, in Step 1, the initial engine performance test is carried out in accordance with "Automobile Engine Reliability Test Method" GB / T19055-2024.

[0007] Furthermore, in Step 1, the gap between the front end of the camshaft phaser of the Hall sensor and the phaser is 0.5 mm - 1.5 mm.

[0008] Furthermore, in Step 1, lead out the three red non-connector signal wires of the Hall sensor from the screw holes at the corresponding positions at the front end of the housing, and use sealant to seal the three red non-connector signal wires.

[0009] Furthermore, in Step 1, the tooling is a solid column and is L-shaped. Threaded holes are provided at both the upper and lower ends of the L-shaped special tooling. A connecting handle is provided on the Hall sensor, and a through hole is provided on the connecting handle. The connecting handle is arranged at the upper end of the L-shaped special tooling. The Hall sensor is firmly connected to the threaded hole at the upper end of the L-shaped special tooling through a screw passing through the through hole of the connecting handle; the cylinder head inside the engine is firmly connected to the threaded hole at the lower end of the L-shaped special tooling through a screw.

[0010] Furthermore, in Step 4, before officially entering the test, in PAK, set the signal sampling frequency to 16384 Hz and the analysis bandwidth to 2 - 6400 Hz.

[0011] Furthermore, in step 5, the test boundary conditions include engine speed and torque; the test operating conditions are: 3700 rpm - 182 Nm; the signal acquisition of the rotational speed signal of the camshaft phaser measured by the Hall sensor is performed, including: observing the current engine oil pressure value in INCA, after 30 s of the test, using INCA to adjust ECU-1 to control the engine oil pressure, reducing it by 20 kPa based on the previously observed value, making the engine in a low oil pressure state, and continuing to acquire data for 30 s to complete a set of 60 s data acquisition. Each set of data consists of the first 30 s and the last 30 s, and two sets of measurements are repeated, with each acquisition time being 60 s.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: The measurement method of the present invention can measure and analyze the torsional vibration at the camshaft phaser end on the engine test bench, analyze the data results, and compare the data in the original state and the data after adjusting the oil pressure under the same operating conditions, so as to determine whether the reduction of the engine oil pressure under this operating condition will cause abnormal operation of the engine camshaft.

[0013] This measurement method can diagnose the spring fracture failure caused by the reduction of the engine oil pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is the system structure design diagram of a measurement method for torsional vibration of a camshaft phaser on an engine test bench according to the present invention; Figure 2 is a schematic diagram of the sensor of the present invention fixed on the tooling; Figure 3 is the design diagram of the special tooling for the sensor of the present invention; Figure 4 is a physical diagram of the sensor of the present invention fixed on the tooling; Figure 5 is the original test data of the test measurement results of the present invention; Figure 6 is a partial view of the test data after adjusting the oil pressure of the test measurement results of the present invention; Figure 7 is an overall view of the test data after adjusting the oil pressure of the test measurement results of the present invention. ?

[0015] The component names and reference numerals involved in the above-mentioned drawings are as follows: 1. ECU-1; 2. ECU-2; 3. Hall sensor; 4. Engine; 5. Camshaft phaser; 6. Tooling; 7. Connecting handle. DETAILED DESCRIPTION OF THE INVENTION

[0016] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0017] Specific Embodiment 1: As Figures 1 to 7 shown, this embodiment records a method for measuring the torsional vibration of the camshaft phase wheel of an engine test bench, including the following steps: Step 1: After the engine 4 passes the initial performance test, subsequent processes are carried out, that is, the synchronous chain cover of the engine 4 is removed, the Hall sensor 3 is installed on the special tooling 6, and then the tooling 6 is fixed to the cylinder head inside the engine 4 and it is ensured that the front end of the Hall sensor 3 is perpendicular to the camshaft phase wheel 5. The signal line of the Hall sensor 3 is led out from the front end of the cover, and then the engine 4 is restored; Step 2: Arrange the intake and exhaust systems and mounts of the engine 4, and install them on the test engine test bench with reference to the vehicle state; Step 3: Connect the test harness of the engine 4 to the ECU-1 (the ECU is the engine electronic control unit), connect the three signal lines of the Hall sensor 3 to the Hall sensor 3 measurement position of the harness two, and then connect the harness two to the ECU-2 2. Check to ensure that the power supply transmission of the test engine test bench to the two sets of the harnesses and the ECU-1 (1) and ECU-2 (2) is normal; Use a single-ended BNC connector signal line to connect the three signal lines of the Hall sensor 3 and connect them to the PAKMobile MKII (front-end device of the data acquisition system), so that the harness two and the PAK Mobile MKII (front-end device of the data acquisition system) are in a parallel state (that is, the signal output by the Hall sensor 3 is connected to the harness two and also connected to the PAKMobile MKII (front-end device of the data acquisition system)); Step 4: Before officially entering the test, connect the front end of the BBM data acquisition system to the test computer through a network cable and use the PAK software for data acquisition; Check the engine status. After confirming no abnormality, connect INCA (a vehicle measurement and calibration tool software developed by ETAS company) for warm-up; Step 5: Control the test boundary conditions to meet the test requirements; when reaching the test condition, operate PAK (test analysis software), and use the PAK Mobile MKII (front-end device of the data acquisition system) to collect the rotational speed signal of the camshaft phase wheel 5 measured by the Hall sensor 3; Step 6: Use PAK (test analysis software) to calculate the time-domain rotational speed data of the Hall sensor 3, calculate the root mean square (RMS) value using PAK, output the original time-domain data, and analyze the data results, that is, compare the data in the original state with the data after adjusting the oil pressure under the same working condition; if after adjusting the oil pressure (the data in the last 30 s), the amplitude of the torsional angular velocity of the camshaft phaser 5 is more than twice the amplitude in the original state (the data in the first 30 s) (showing a non-persistent excessive change), it can be determined that the abnormal operation of the camshaft of the engine 4 is caused by the reduction of the oil pressure under this working condition.

[0018] Specific Embodiment 2: As Figures 1 to 7 shown, this embodiment is a further description of Specific Embodiment 1. In Step 1, the initial performance test of the engine 4 is carried out in accordance with "Automobile Engine Reliability Test Method" GB / T19055-2024.

[0019] Specific Embodiment 3: As Figures 1 to 7 shown, this embodiment is a further description of Specific Embodiment 1. In Step 1, the clearance between the front end of the Hall sensor 3 and the camshaft phaser 5 is 0.5 mm - 1.5 mm.

[0020] Specific Embodiment 4: As Figures 1 to 7 shown, this embodiment is a further description of Specific Embodiment 1. In Step 1, the three red non-connector signal wires of the Hall sensor 3 are led out from the screw holes at the corresponding positions at the front end of the housing, and sealant is used to seal the three red non-connector signal wires.

[0021] Specific Embodiment 5: As Figures 1 to 7 shown, this embodiment is a further description of Specific Embodiment 1. In Step 1, the tooling 6 is a solid column and is L-shaped. Threaded holes are provided at both the upper and lower ends of the L-shaped special tooling 6. A connecting handle 7 is provided on the Hall sensor 3, and a through hole is provided on the connecting handle 7. The connecting handle 7 is arranged at the upper end of the L-shaped special tooling 6. The Hall sensor 3 is fixedly connected to the threaded hole at the upper end of the L-shaped special tooling 6 by a screw passing through the through hole of the connecting handle 7; the cylinder head inside the engine 4 is fixedly connected to the threaded hole at the lower end of the L-shaped special tooling 6 by a screw.

[0022] Specific Embodiment 6: As Figures 1 to 7 shown, this embodiment is a further description of Specific Embodiment 1. In Step 4, before officially entering the test, in PAK (test analysis software), set the signal sampling frequency to 16384 Hz and the analysis bandwidth to 2 - 6400 Hz.

[0023] Specific Embodiment 7: As Figures 1 to 7As shown, this embodiment is a further description of the first specific embodiment. In step 5, the test boundary conditions include the engine 4 speed and torque; the test conditions are: 3700 rpm - 182 Nm (engine 4 speed 3700 rpm / min, torque 182 Nm); the rotational speed signal of the camshaft phaser 5 measured by the Hall sensor 3 is collected; it includes: observing the current engine oil pressure value in INCA (a vehicle measurement and calibration tool software developed by ETAS), after 30 s of the test, using INCA (a vehicle measurement and calibration tool software developed by ETAS) to adjust ECU-1 to control the engine oil pressure of the engine 4, reducing it by 20 kPa based on the previously observed value, making the engine 4 in a low oil pressure state, and continuing to collect data for 30 s to complete a set of 60 s data collection. Each set of data consists of the first 30 s (original state) and the last 30 s (adjusted oil pressure state). Repeat two sets of measurements, and the collection time for each set is 60 s.

[0024] The working principle of the present invention is: design a new measurement method, fix the Hall sensor inside the engine using a fixed tooling, measure the rotational speed signal of the camshaft phaser using the Hall sensor, use PAK (test analysis software) of PAK MobileMKII (front-end device of the data acquisition system) to calculate the time-domain rotational speed data of the Hall sensor, the software calculates the effective value RSM, outputs its time-domain original data, and analyzes the test data to achieve the purpose of diagnosing the faults of the engine camshaft phaser.

[0025] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent conditions of the claims are intended to be encompassed by the present invention. Any reference signs in the claims should not be regarded as limiting the claimed claims.

[0026] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for measuring the torsional vibration of the camshaft phase wheel on an engine test bench, characterized in that: The method includes the following steps: Step 1: After the engine (4) passes the initial performance test, proceed with the subsequent processes. That is, remove the synchronous chain cover of the engine (4), install the Hall sensor (3) on the special tooling (6), then fix the tooling (6) to the cylinder head inside the engine (4), and ensure that the front end of the Hall sensor (3) is perpendicular to the camshaft phaser (5). Lead out the signal wire of the Hall sensor (3) from the front end of the cover, and then restore the engine (4). Step 2: Arrange the engine intake and exhaust systems and mounts, and install them on the test engine (4) bench with reference to the vehicle state. Step 3: Connect the test harness of the engine (4) to the ECU-1 (1). Connect the three signal wires of the Hall sensor (3) to the measurement position of the Hall sensor (3) on the harness-2, and then connect the harness-2 to the ECU-2 (2). Check to ensure that the power supply transmission of the test engine (4) bench to the two sets of the harnesses and the ECU-1 (1) and ECU-2 (2) is normal. Use a signal wire with a single-ended BNC connector to connect the three signal wires of the Hall sensor (3) and connect them to the PAKMobile MKII, so that the harness-2 and the PAK Mobile MKII are in a parallel state. Step 4: Before officially entering the test, connect the front end of the BBM data acquisition system to the test computer through a network cable and use the PAK software for data acquisition. Check the state of the engine (4). After confirming no abnormalities, connect INCA for warm-up. Step 5: Control the test boundary conditions to meet the test requirements. When reaching the test condition, operate PAK and use the PAKMobile MKII to collect the rotational speed signal of the camshaft phaser (5) measured by the Hall sensor (3). Step 6: Use PAK to calculate the time-domain rotational speed data of the Hall sensor (3), calculate the effective value RSM using PAK, output its time-domain original data and analyze the data results, that is, compare the data in the original state and the data after adjusting the oil pressure under the same working condition. If the amplitude of the torsional angular velocity of the camshaft phaser (5) is more than twice the amplitude of the original state after adjusting the oil pressure, it can be determined that the abnormal operation of the camshaft of the engine (4) is caused by the reduction of the oil pressure under this working condition.

2. The method for measuring the torsional vibration of the camshaft phase wheel of an engine test bench according to claim 1, wherein: In Step 1, the initial performance test of the engine (4) is carried out in accordance with the "Automobile Engine Reliability Test Method" GB / T19055-2024.

3. The method for measuring the torsional vibration of the camshaft phase wheel on the engine test bench according to claim 1, wherein: In Step 1, the gap between the front end of the Hall sensor (3) and the camshaft phaser (5) is 0.5 mm - 1.5 mm.

4. The method for measuring the torsional vibration of the camshaft phase wheel of an engine test bench according to claim 1, characterized in that: In Step 1, lead out the three red non-connector signal wires of the Hall sensor (3) from the screw holes at the corresponding positions at the front end of the cover, and use sealant to seal the three red non-connector signal wires.

5. The method for measuring the torsional vibration of the camshaft phaser on the engine test bench according to claim 1, wherein: In Step 1, the tooling (6) is a solid column and is L-shaped. Threaded holes are provided at both the upper and lower ends of the L-shaped special tooling (6). A connecting handle (7) is provided on the Hall sensor (3), and a through hole is provided on the connecting handle (7). The connecting handle (7) is arranged at the upper end of the L-shaped special tooling (6). The Hall sensor (3) is fixedly connected to the threaded hole at the upper end of the L-shaped special tooling (6) by a screw passing through the through hole of the connecting handle (7); the cylinder head inside the engine (4) is fixedly connected to the threaded hole at the lower end of the L-shaped special tooling (6) by a screw.

6. The method for measuring the torsional vibration of the camshaft phase wheel on the engine test bench according to claim 1, wherein: In Step 4, before the formal test, in the PAK, set the signal sampling frequency to 16384 Hz and the analysis bandwidth to 2 - 6400 Hz.

7. The method for measuring the torsional vibration of the camshaft phaser on the engine test bench according to claim 1, wherein: In Step 5, the test boundary conditions include the engine (4) speed and torque; the test working condition is: 3700 rpm - 182 Nm; Collect the rotational speed signal of the camshaft phase wheel (5) measured by the Hall sensor (3); including: observe the current engine oil pressure value in INCA. After the test has been carried out for 30 s, use INCA to adjust ECU-1 (1) to control the engine oil pressure of the engine (4) to decrease by 20 kPa based on the previously observed value, so that the engine (4) is in a low oil pressure state, and continue to collect data for 30 s to complete a set of 60 s data collection. Each set of data consists of the first 30 s and the last 30 s. Repeat the measurement twice, and the collection time for each set is 60 s.

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