An assembling tool and adjusting method of a ship diesel engine output end angle encoder

Abstract

This invention belongs to the field of marine diesel engine monitoring and control technology, and relates to an assembly fixture and adjustment method for an angle encoder at the output end of a marine diesel engine. The assembly fixture includes an arc-shaped positioning body with a T-shaped cross-section. One end has a first semi-circular slot and a second semi-circular slot, and the other end has a mounting through hole and a positioning bolt. The axial distance between the two semi-circular slots is S = (n + 3 / 4) × CJ, where CJ is the tooth pitch of the trigger signal ring. During adjustment, the circular runout of the flywheel semi-circular ring and the trigger signal ring is checked first. The positions of the main control and redundant sensors are adjusted sequentially. Then, the assembly fixture is used to simultaneously limit the radial clearance and phase difference between the two main control sensors and the two redundant sensors, precisely ensuring their relative positions. This invention solves the problems of improving sensor installation accuracy and signal stability, avoiding unexpected diesel engine shutdowns due to signal loss, simplifying the on-site debugging process, and enhancing the redundancy reliability of the encoder system.

Description

Technical Field

[0001] This invention belongs to the field of marine diesel engine monitoring and control technology, and relates to an assembly tooling and adjustment method for an angle encoder at the output end of a marine diesel engine. Background Technology

[0002] Currently, with the widespread adoption of shaft-driven generators and other equipment in marine diesel engines, traditional angle encoders often cannot be installed due to the free end being occupied. Instead, distributed angle encoder systems are installed at the main engine output end: i.e., on the flywheel side. For example... Figures 1 to 5 As shown: The angle encoder at the output end of the marine diesel engine consists of two groups of eight proximity sensors: a main control sensor group and a redundant sensor group. The main control sensor group and the redundant sensor group monitor each other. The main control sensor group includes a first main control sensor MMA, a second main control sensor MSA, a third main control sensor Q1A, and a fourth main control sensor Q2A. The first main control sensor MMA and the second main control sensor MSA are fixedly installed at the output end of the marine diesel engine through MSA and MMA probe boxes 21. The third main control sensor Q1A and the fourth main control sensor Q2A are fixedly installed at the output end of the marine diesel engine through Q1A probe boxes 31 and Q2A probe boxes 32, respectively. The redundant sensor... The system comprises: a first redundant sensor MMB, a second redundant sensor MSB, a third redundant sensor Q1B, and a fourth redundant sensor Q2B. The first and second redundant sensors MMB and MSB are fixedly mounted on the output end of the marine diesel engine via MSB and MMB probe boxes 22. The third and fourth redundant sensors Q1B and Q2B are fixedly mounted on the output end of the marine diesel engine via Q1B probe boxes 33 and Q2B probe boxes 34, respectively. Two sets of semicircular rings are installed on the flywheel 1 mounted on the diesel engine body 100. One set of semicircular rings, the inner semicircular ring 11, is closer to the flywheel 1, and the other set, the outer semicircular ring 12, is closer to one side of the diesel engine body 100. When the flywheel 1 is rotated until the pointer is at the top dead center (0°) of cylinder #1, the probe of the first main control sensor MMA should just enter the semicircular ring near the flywheel. Within the 0-180° range, the first main control sensor MMA detects a signal, and the sensor indicator light illuminates. When the crankshaft is cranked until the flywheel pointer is at 90°, the second main control sensor MSA should just enter the outer semicircular ring 12 of the flywheel. Within the range of 90-270°, the second main control sensor MSA detects a signal, and the sensor indicator light illuminates. Combining the detection signals from the third main control sensor Q1A and the fourth main control sensor Q2A, the actual rotation angle and speed of the crankshaft 3 are calculated and transmitted to the diesel engine main control system for controlling the diesel engine start-up, fuel injection, exhaust valve opening and closing, and fuel injector filling, etc.

[0003] However, in the actual installation and commissioning process of existing technologies, the adjustment of such encoders has significant drawbacks. First, due to the variety of sensors used in angle encoders—M12 marking probes and M18 speed probes are mixed together and installed in dispersed locations—traditional commissioning methods rely on repeated manual adjustments to the radial clearance and axial position of each probe, making it difficult to guarantee accuracy. In particular, the phase difference requirement between the two speed sensors in the same group—the third main control sensor Q1A and the fourth main control sensor Q2A—is extremely strict. They must precisely maintain a relative distance of 1 / 4 of the trigger signal ring tooth pitch to determine forward and reverse movement. However, effective positioning methods are often lacking on-site, and relying solely on visual inspection or feeler gauge measurements is prone to errors. Second, the vibration and thermal expansion of the diesel engine during operation can cause changes in the probe clearance. If the initial installation is improper, such as too small or too large a clearance, or misalignment of the probes, alarms such as signal corruption, excessive angle deviation, or signal loss are likely to occur during high-speed operation. Once both the main control and redundant signal sets fail simultaneously, the diesel engine will trigger a safety shutdown, seriously affecting the ship's navigation safety and operational efficiency. Therefore, there is an urgent need for a standardized and high-precision adjustment method to solve the problems of difficult assembly, cumbersome debugging and poor reliability in existing technologies. Summary of the Invention

[0004] This invention addresses the problems of complex adjustment methods and inconsistent accuracy of existing angle encoders installed at the output end of marine diesel engines, leading to alarms such as signal malfunctions, excessive angle deviations, or signal loss during high-speed engine operation. The invention proposes an assembly fixture for an angle encoder at the output end of a marine diesel engine, comprising: an arc-shaped positioning body, which includes mutually perpendicular arc-shaped and straight sections with a T-shaped cross-section; wherein the arc-shaped section has an arc-shaped structure; the inner and outer arc surfaces of the arc-shaped section are coaxial and parallel to each other; the straight section is a flat thin plate structure; one end of the arc-shaped section is provided with a first semi-circular slot and a second semi-circular slot for respectively engaging with the probes of the fourth main control sensor Q2A and the third main control sensor Q1A of the marine diesel engine output angle encoder; the axes of the first and second semi-circular slots are both perpendicular to the outer arc surface of the arc-shaped section.

[0005] The other end of the arc section is provided with a mounting through hole; the axis of the mounting through hole is perpendicular to the arc surface of the arc section; a positioning bolt is inserted into the mounting through hole, and the positioning bolt is used to screw into the tooth groove of the trigger signal ring of the angle encoder at the output end of the marine diesel engine, so as to realize the detachable positioning connection between the assembly fixture and the trigger signal ring.

[0006] The first and second semicircular slots are blind holes; the distances between the bottom surface of the first and second semicircular slots and the inner arc surface of the arc section are equal to the distances between the probe end face of the fourth main control sensor Q2A and the probe end face of the third main control sensor Q1A and the tooth tip of the trigger signal ring, respectively, so as to limit the radial clearance between the probe end face of the fourth main control sensor Q2A and the probe end face of the third main control sensor Q1A and the tooth tip of the trigger signal ring of the angle encoder at the output end of the marine diesel engine;

[0007] The distance S between the axis of the first semicircular slot and the axis of the second semicircular slot satisfies: S = (n + 3 / 4) × CJ, where n is a non-negative integer and CJ is the tooth pitch of the trigger signal ring;

[0008] The assembly fixture engages with the toothed groove of the trigger signal ring via the positioning bolt, and sequentially engages the probes of the fourth main control sensor Q2A and the third main control sensor Q1A, thereby precisely defining the relative circumferential phase difference between the two sensor probes and the radial clearance between each probe and the tooth tip of the trigger signal ring.

[0009] According to the assembly fixture for the output angle encoder of a marine diesel engine described above, the diameters of the first semicircular slot and the second semicircular slot are respectively matched with the diameters of the probes of the fourth main control sensor Q2A and the third main control sensor Q1A, forming a clearance fit, so that the sensor probes can be freely inserted or withdrawn.

[0010] According to the assembly fixture for the output angle encoder of a marine diesel engine described above, the bottom surface of the first semicircular slot and the bottom surface of the second semicircular slot are arc surfaces coaxial with the trigger signal ring, and their arc radius is greater than the tooth tip circle radius of the trigger signal ring.

[0011] According to the above-described assembly fixture for an angle encoder at the output end of a marine diesel engine, the head of the positioning bolt is provided with an internal hexagonal hole, and its end is a smooth rod, which is used to insert into the bottom of the tooth groove of the trigger signal ring, while ensuring that the fixture can be finely adjusted along the tooth groove direction of the trigger signal ring before being locked.

[0012] According to the assembly fixture of the angle encoder at the output end of a marine diesel engine described above, the thickness of the flat thin plate structure of the positioning body is 4mm-6mm. The flat thin plate structure is used to fit the tooth tip circle surface of the trigger signal ring during assembly and provide support.

[0013] According to the above-described assembly fixture for an angle encoder at the output end of a marine diesel engine, the assembly fixture further includes a detachable hand handle, which is connected to the other end of the positioning body via a snap-fit ​​structure, for holding and positioning the assembly fixture in a confined space.

[0014] According to the above-described assembly fixture for an angle encoder at the output end of a marine diesel engine, the assembly fixture is made of wear-resistant metal material, and its surface is treated with rust prevention. The inner walls and bottom surfaces of the first and second semicircular slots are all polished.

[0015] According to the above-described assembly fixture for an angle encoder at the output end of a marine diesel engine, the positioning body is provided with a direction mark, which is used to indicate that the fixture is facing the fuel side during installation.

[0016] A method for adjusting a marine diesel engine output angle encoder, using any of the above-described assembly fixtures for marine diesel engine output angle encoders, includes the following steps:

[0017] Step S1: Perform a circular runout check on the inner and outer semicircular rings of the flywheel installed on one side of the flywheel to ensure that their circular runout tolerance is <0.5mm, and mark their highest points;

[0018] Step S2: Perform a circular runout check on the trigger signal loop to ensure that its circular runout tolerance is <0.5mm, and mark its highest point;

[0019] Step S3: Rotate the machine to the 0° position and adjust the position of the first main control sensor MMA so that the distance between the end face of the probe of the first main control sensor MMA and the outer wall of the inner semicircular ring of the flywheel is 2mm-4mm. Ensure that the central axis of the probe of the first main control sensor MMA coincides with the end face of the starting end of the inner semicircular ring of the flywheel and is perpendicular to the ring surface of the inner semicircular ring of the flywheel.

[0020] Rotate the rotor to the 45° position and adjust the position of the second main control sensor MSA so that the distance between the end face of the probe of the second main control sensor MSA and the outer wall of the inner semicircular ring of the flywheel is 2mm-4mm. Ensure that the central axis of the probe of the second main control sensor MSA coincides with the end face of the starting end of the inner semicircular ring of the flywheel and is perpendicular to the ring surface of the inner semicircular ring of the flywheel.

[0021] Rotate the wheel to the 90° position and adjust the probe of the first main control sensor MMA so that the distance between the end face of the probe of the first main control sensor MMA and the outer wall of the outer semicircular ring of the flywheel is 2mm-4mm. Ensure that the central axis of the probe of the first main control sensor MMA coincides with the end face of the starting end of the outer semicircular ring of the flywheel and is perpendicular to the ring surface of the outer semicircular ring of the flywheel.

[0022] Rotate the rotor to the 135° position and adjust the probe of the second redundant sensor MSB so that the distance between the end face of the probe of the second redundant sensor MSB and the outer wall of the outer semicircular ring of the flywheel is 2mm-4mm. Also, ensure that the central axis of the probe of the second redundant sensor MSB coincides with the end face of the starting end of the outer semicircular ring of the flywheel and is perpendicular to the ring surface of the outer semicircular ring of the flywheel.

[0023] Step S4: Use the assembly fixture for the output angle encoder of a marine diesel engine described above to position and adjust the probe of the fourth main control sensor Q2A and the probe of the third main control sensor Q1A;

[0024] Rotate the machine to 0° and insert the probe of the fourth main control sensor Q2A into the second semi-circular slot of the positioning body;

[0025] Screw the positioning bolt on the mounting through hole into the tooth groove of the trigger signal ring closest to the probe axis of the fourth main control sensor Q2A, so that it can be locked in place by the assembly fixture.

[0026] Adjust the probe end face of the fourth main control sensor Q2A to just contact the bottom surface of the first semi-circular slot, and ensure that the positioning body can be freely pulled out. After adjusting the position of the fourth main control sensor Q2A, lock and fix it by its back cap.

[0027] Remove the positioning body and positioning bolts, move the positioning body to the third main control sensor Q1A and use the positioning bolts to engage the tooth groove of the signal transmitting ring;

[0028] Fine-tune the probe of the third master control sensor Q1A so that it can be freely inserted into the second semi-circular slot on the positioning body. This is equivalent to the relative position between the third master control sensor Q1A and the fourth master control sensor Q2A being an integer number of trigger signal ring tooth pitches plus 3 / 4 tooth pitch.

[0029] Adjust the probe end face of the third main control sensor Q1A to just contact the bottom surface of the second semi-circular slot, and ensure that the positioning body can be freely pulled out. Then lock the back cap of the third main control sensor Q1A. At this point, the position adjustment of the third main control sensor Q1A and the fourth main control sensor Q2A is completed.

[0030] Step S5: Use the assembly fixture for the output angle encoder of a marine diesel engine described above to position and adjust the probe of the fourth redundant sensor Q2B and the probe of the third redundant sensor Q1B.

[0031] Rotate the wheel to 45°. At this point, the central axis of the probe of the second main control sensor MSA coincides with the end face of the starting end of the inner semi-circular ring of the flywheel.

[0032] Insert the probe of the fourth redundant sensor Q2B into the first semi-circular slot of the positioning body.

[0033] Screw the positioning bolt on the mounting through hole into the tooth groove of the trigger signal ring so that the positioning bolt is properly locked in the assembly fixture.

[0034] Adjust the probe end face of the fourth redundant sensor Q2B to just contact the bottom surface of the first semi-circular slot, and ensure that the positioning body can be freely pulled out. After adjusting the position of the fourth redundant sensor Q2B, lock and fix it by its back cap.

[0035] Remove the positioning body and positioning bolts, move the positioning body to the third redundant sensor Q1B and use the positioning bolts to engage the tooth groove of the signal transmitting ring;

[0036] Fine-tune the probe of the third redundant sensor Q1B so that it can be freely inserted into the second semi-circular slot on the positioning body, and make the relative position between the third redundant sensor Q1B and the fourth redundant sensor Q2B an integer number of trigger signal ring tooth pitches plus 3 / 4 tooth pitch.

[0037] Adjust the probe end face of the third redundant sensor Q1B to just contact the bottom surface of the second semi-circular slot, and ensure that the positioning body can be freely pulled out. Then lock the back cap of the third redundant sensor Q1B. At this point, the position adjustment of the third redundant sensor Q1B and the fourth redundant sensor Q2B is completed.

[0038] Step S6: Rotate the machine around once to verify the trigger range of each probe signal, ensuring that the light is on within the specified angle and there is no trigger signal at other positions.

[0039] According to the above-described method for adjusting the angle encoder at the output end of a marine diesel engine, in step S2, the circular runout of the trigger signal ring is checked using a dial indicator. If the circular runout is >0.5mm, the outer circle of the trigger signal ring needs to be machined.

[0040] In step S3, the probe of the first master control sensor MMA is adjusted when the crankshaft is rotated to 0°, so that the distance between the end face of the probe of the first master control sensor MMA and the outer wall of the inner semicircular ring of the flywheel is 3mm; the probe of the first master control sensor MMA is adjusted when the crankshaft is rotated to 90°, so that the distance between the end face of the probe of the first master control sensor MMA and the outer wall of the outer semicircular ring of the flywheel is 3mm, ensuring that it can detect signals in the range of 90° to 270° to assist in determining the crankshaft position; the probe of the second master control sensor MSA is adjusted when the crankshaft is rotated to 45°, so that the distance between the end face of its probe and the outer wall of the inner semicircular ring of the flywheel is 3mm, covering the signal range of 45° to 225°; the probe of the second redundant sensor MSB is adjusted when the crankshaft is rotated to 135°, so that the distance between the end face of its probe and the outer wall of the outer semicircular ring of the flywheel is 3mm, covering the signal range of 135° to 315°.

[0041] The beneficial effects of this invention are as follows:

[0042] 1. Significantly improves installation accuracy, avoids critical phase errors, solves the phase error problem, and ensures accurate forward and reverse vehicle judgment. This invention addresses the pain point of difficulty in controlling the 1 / 4 trigger signal ring tooth pitch between the third main control sensor Q1A and the fourth main control sensor Q2A in existing technologies. Through a dedicated assembly fixture, utilizing its precise slot center distance S=(n+3 / 4)×CJ, it transforms traditional visual movement into fixture positioning. Compared with existing technologies, this method completely eliminates visual and tactile errors caused by manual probe movement, strictly ensuring a precise 90° difference in the electrical phase angle between the two speed probes, ensuring absolute accuracy in forward and reverse vehicle judgment, and fundamentally preventing angle calculation errors caused by inaccurate phase.

[0043] 2. Optimizing the gap setting improves operational stability, enhances vibration and thermal stability, and reduces signal loss. Existing technologies have excessively small radial gaps between the probe end face and the trigger signal ring tooth tip (e.g., 1mm), which can easily lead to rubbing during high-speed operation. Conversely, excessively large gaps can result in signal loss. This invention, based on theoretical detection distances of 0.1-6mm and practical experience, optimizes the marking probe's installation gap to an optimal range of 2.5-3.0mm. Furthermore, the thickness of the assembly tooling's arc surface strictly ensures the consistency of the speed probe's gap. This improvement effectively compensates for the radial runout and thermal expansion of the flywheel during diesel engine operation, resolving the signal drift and signal loss alarm problems caused by vibration and gap variations in existing technologies, and significantly improving signal transmission stability.

[0044] 3. Simplified operation process and improved commissioning efficiency. Traditional commissioning requires two skilled technicians to work together, repeatedly maneuvering, measuring, and trial-and-error, often taking several hours and yielding unstable results. This invention standardizes the complex eight-probe adjustment process into a single step: first checking for runout, then aligning the markings, and finally using assembly fixtures to determine the phase. In particular, by utilizing assembly fixtures to simultaneously set the gap and phase of the third main control sensor Q1A and the fourth main control sensor Q2A, operators can quickly and accurately complete the installation without requiring specialized measurement experience. Compared with existing technologies, this method greatly simplifies the operation, reduces the commissioning time by more than 70%, and significantly improves the installation efficiency during ship construction or maintenance.

[0045] 4. Enhanced reliability of redundant structures, preventing unexpected shutdowns. This invention improves the adjustment accuracy of both the main control group sensors and the redundant group sensors by using the same assembly tooling and adhering to the same standards. By ensuring that the signals from both encoders are accurate within their respective operating ranges, the deviation between the two systems is minimal in hot standby mode. When the main control group sensors fail, the redundant group sensors can seamlessly switch over, effectively solving the problem in existing technologies where large adjustment deviations in the redundant group sensors lead to unusable backup signals after the main control group sensors fail. This completely eliminates unexpected diesel engine shutdowns caused by a complete failure of the angle encoders, ensuring safe navigation for the ship.

[0046] 5. Establish a full-process quality control method to ensure assembly accuracy. This invention breaks through the limitations of traditional methods that only focus on sensor-to-point measurements, moving assembly accuracy control forward to the machining and assembly stages of mechanical components. Before using the assembly fixture, steps S1 and S2 mandate the inspection and precision machining of the inner semicircular ring of the flywheel, the outer semicircular ring of the flywheel, and the trigger signal ring to ensure that the accuracy of the basic mechanical components meets the standards. Compared with the existing technology that ignores mechanical runout and only adjusts the sensors, this invention, through full-process quality control of "checking runout first, then using the fixture," ensures that subsequent electrical debugging is based on a solid mechanical foundation. This solves the problem of inconsistent signal quality during later operation caused by ignoring mechanical runout and only adjusting sensors in the existing technology, ensuring the stability and consistency of assembly accuracy. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the sensor installation structure for the angle encoder at the output end of a marine diesel engine.

[0048] Figure 2 The upper half of the AA cross-sectional view is a schematic diagram of the installation structure of the sensor for the angle encoder at the output end of a marine diesel engine.

[0049] Figure 3 This is a perspective view of the lower half of the AA sectional view of the sensor installation structure of the angle encoder at the output end of a marine diesel engine.

[0050] Figure 4 This is an enlarged view along the M direction of the upper half of the AA sectional view of the sensor installation structure of the angle encoder at the output end of a marine diesel engine.

[0051] Figure 5 This is an enlarged perspective view (N direction) of the lower half of the AA sectional view of the sensor installation structure of the angle encoder at the output end of a marine diesel engine.

[0052] Figure 6 This is a partial enlarged view of the trigger signal loop of the angle encoder at the output end of a marine diesel engine.

[0053] Figure 7 This is a front view of a structural schematic diagram of an assembly fixture for an angle encoder at the output end of a marine diesel engine according to the present invention.

[0054] Figure 8 This is a C-axis sectional view of the main view of an assembly tooling for an angle encoder at the output end of a marine diesel engine, according to the present invention.

[0055] Figure 9 This is a top view of the structural schematic diagram of an assembly fixture for an angle encoder at the output end of a marine diesel engine according to the present invention.

[0056] Figure 10 This is a top view and a DD-direction sectional view of a structural schematic diagram of an assembly tooling for an angle encoder at the output end of a marine diesel engine according to the present invention.

[0057] Figure 11 This is a schematic diagram of the assembly of the positioning body and positioning bolts of the assembly fixture for an angle encoder at the output end of a marine diesel engine according to the present invention.

[0058] Figure 12 This is a schematic diagram of the assembly fixture and trigger signal loop for an angle encoder at the output end of a marine diesel engine according to the present invention.

[0059] In the diagram: 1-Flywheel, 11-Inner semicircular ring of flywheel, 12-Outer semicircular ring of flywheel, 2-Trigger signal ring, 21-MSA, MMA probe box, 22-MSB, MMB probe box, 3-Crankshaft, 31-Q1A probe box, 32-Q2A probe box, 33-Q1B probe box, 34-Q2B probe box, 100-Diesel engine block, 110-Fuel side, 120-Exhaust side, 4-Positioning body, 41-First semicircular slot, 42-Second semicircular slot, 43-Mounting through hole, 44-Positioning bolt. Detailed Implementation

[0060] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0061] like Figures 1 to 5As shown: In this embodiment, the angle encoder installed at the output end of the marine diesel engine consists of four proximity sensors in each group, for a total of two groups: a main control sensor group and a redundant sensor group. The main control sensor group and the redundant sensor group monitor each other. The main control sensor group includes a first main control sensor MMA, a second main control sensor MSA, a third main control sensor Q1A, and a fourth main control sensor Q2A. The first main control sensor MMA and the second main control sensor MSA are fixedly installed at the output end of the marine diesel engine through MSA and MMA probe boxes 21. The third main control sensor Q1A and the fourth main control sensor Q2A are fixedly installed at the output end of the marine diesel engine through Q1A probe boxes 31 and Q2A probe boxes 32, respectively.

[0062] The redundant sensor group includes: a first redundant sensor MMB, a second redundant sensor MSB, a third redundant sensor Q1B, and a fourth redundant sensor Q2B; the first redundant sensor MMB and the second redundant sensor MSB are fixedly installed at the output end of the marine diesel engine through MSB and MMB probe boxes 22; the third redundant sensor Q1B and the fourth redundant sensor Q2B are fixedly installed at the output end of the marine diesel engine through Q1B probe boxes 33 and Q2B probe boxes 34, respectively.

[0063] Two sets of semicircular rings are installed on the flywheel 1 mounted on the diesel engine block 100. One set of semicircular rings, the inner semicircular ring 11, is closer to the flywheel 1, and the other set, the outer semicircular ring 12, is closer to the side of the diesel engine block 100. When the cranking is turned until the pointer of the flywheel 1 is at the top dead center (0°) of cylinder #1, the probe of the first main control sensor MMA should just enter the semicircular ring near the flywheel. Within the range of 0-180°, the first main control sensor MMA detects a signal, and the sensor indicator light illuminates. When the cranking is turned until the pointer of the flywheel is at 90°, the second main control sensor MSA should just enter the outer semicircular ring 12 of the flywheel. Within the range of 90-270°, the second main control sensor MSA detects a signal, and the sensor indicator light illuminates. Combining the detection signals of the third main control sensor Q1A and the fourth main control sensor Q2A, the actual rotation angle and speed signal of the crankshaft 3 are calculated and transmitted to the diesel engine main control system for controlling the diesel engine start-up, fuel injection, exhaust valve opening and closing, and fuel injector filling, etc.

[0064] This embodiment of a method for adjusting the angle encoder at the output end of a marine diesel engine includes the following steps:

[0065] Step S1: Pre-inspection and processing of the inner semicircular ring 11 and the outer semicircular ring 12 of the flywheel;

[0066] Before installing the sensor, the accuracy of the mechanical components must first be checked. Rotate the flywheel 1 of the diesel engine and use a dial indicator to measure the circular runout of the inner semicircular ring 11 and the outer semicircular ring 12 of the flywheel. The circular runout tolerance must be strictly controlled within 0.5mm to prevent erroneous signals caused by drastic changes in the gap between the sensor and the ring surface due to excessive ring oscillation. Clearly mark the measured highest point with a marker.

[0067] Step S2: Fine machining of trigger signal loop 2;

[0068] The trigger signal ring 2 is a key component for generating speed pulses. Since this ring is typically composed of multiple arc-shaped blocks, it is prone to deformation after assembly. This method requires that the overall circular runout be checked on a grinding machine after the ring is assembled. If the dial indicator shows a runout exceeding 0.5mm, the outer circle of the ring, i.e., the addendum circle, must be machined as a whole until the tolerance requirements are met. This step is a prerequisite for ensuring a uniform and stable speed probe signal.

[0069] Step S3: Mark the phase and gap adjustment of the first master control sensor MMA, the second master control sensor MSA, the first redundant sensor MMB, and the second redundant sensor MSB;

[0070] The aforementioned sensor is used to determine the absolute angle range of crankshaft 3, and its installation position must strictly correspond to the inner semicircular ring 11 and the outer semicircular ring 12 of the flywheel.

[0071] First, rotate the flywheel 1 until the pointer points to 0°, which is the top dead center of cylinder #1. Then, adjust the first main control sensor MMA. During adjustment, ensure that the central axis of the probe of the first main control sensor MMA coincides exactly with the end face of the starting end of the inner semicircular ring 11 of the flywheel, and the probe must be perpendicular to the ring surface. Adjust the radial distance of the probe so that the gap between its end face and the outer wall of the ring is 2mm-4mm, preferably 3mm in this embodiment. At this point, rotate the probe to confirm that the indicator light should illuminate precisely at the 0° position, indicating that it has just entered the sensing zone.

[0072] When the rotation reaches 45°, adjust the second main control sensor MSA to ensure that its central axis coincides with the starting end face of the inner semicircular ring 11, and adjust the gap to 3mm to ensure that it can sense within the range of 45° to 225°.

[0073] When the flywheel is rotated to 90°, adjust the first main control sensor MMA so that it is aligned with the starting end of the outer semicircular ring 12 of the flywheel, and adjust the gap to 3mm to ensure that it can sense within the range of 90° to 270°.

[0074] When the flywheel is rotated to 135°, adjust the second redundant sensor MSB so that it is aligned with the starting end of the outer semicircular ring 12 of the flywheel, and adjust the gap to 3mm to ensure that it can sense within the range of 135° to 315°.

[0075] After all adjustments are completed, the engine must be rotated at least one full turn, and the illumination range of each probe indicator light must be visually checked to ensure it conforms to the above range. False triggering in other angle areas is strictly prohibited.

[0076] Step S4: Precisely adjust the phase difference between the fourth master control sensor Q2A and the third master control sensor Q1A.

[0077] The fourth main control sensor Q2A and the third main control sensor Q1A are used to generate pulse counts and determine the direction of rotation. Their relative position accuracy is the key to determining the function of the encoder.

[0078] First, rotate the probe markings of both the fourth main control sensor Q2A and the third main control sensor Q1A to face the forward direction of the vehicle, i.e., the fuel side 110, with the other side of the fuel side 110 being the exhaust side 120. Rotate the vehicle to the 0° position. At this point, the central axis of the first main control sensor MMA probe coincides with the starting end face of the inner semicircular ring 11. Use this as a reference to begin adjusting the fourth main control sensor Q2A.

[0079] This embodiment uses an assembly fixture for an angle encoder at the output end of a marine diesel engine for auxiliary positioning. For example... Figures 7 to 12 As shown, an assembly fixture for a marine diesel engine output angle encoder according to this embodiment includes: an arc-shaped positioning body 4, which includes an arc-shaped part and a straight part that are perpendicular to each other, and its cross-section is T-shaped; wherein the arc-shaped part is an arc-shaped structure; the inner arc surface and the outer arc surface of the arc-shaped part are coaxial and parallel to each other; the straight part is a flat thin plate structure; one end of the arc-shaped part is provided with a first semi-circular slot 41 and a second semi-circular slot 42 for respectively adapting and engaging with the probes of the fourth main control sensor Q2A and the third main control sensor Q1A of the marine diesel engine output angle encoder; the axis of the first semi-circular slot 41 and the axis of the second semi-circular slot 42 are both perpendicular to the outer arc surface of the arc-shaped part;

[0080] The other end of the arc section is provided with a mounting through hole 43; the axis of the mounting through hole 43 is perpendicular to the arc surface of the arc section; a positioning bolt 44 is inserted into the mounting through hole 43, and the positioning bolt 44 is used to screw into the tooth groove of the trigger signal ring 2 of the angle encoder at the output end of the marine diesel engine, so as to realize the detachable positioning connection between the assembly fixture and the trigger signal ring 2.

[0081] The first semicircular slot 41 and the second semicircular slot 42 are blind holes; the distance between the bottom surface of the first semicircular slot 41 and the bottom surface of the second semicircular slot 42 and the inner arc surface of the arc strip is equal to the distance between the probe end face of the fourth main control sensor Q2A and the probe end face of the third main control sensor Q1A and the tooth tip of the trigger signal ring 2, respectively, so as to limit the radial clearance between the probe end face of the fourth main control sensor Q2A and the probe end face of the third main control sensor Q1A and the tooth tip of the trigger signal ring 2 of the marine diesel engine output angle encoder;

[0082] The distance S between the axis of the first semicircular slot 41 and the axis of the second semicircular slot 42 satisfies: S = (n + 3 / 4) × CJ, where n is a non-negative integer and CJ is the tooth pitch of the trigger signal ring 2;

[0083] The assembly fixture engages with the toothed groove of the trigger signal ring 2 via the positioning bolt 44, and sequentially engages the probes of the fourth main control sensor Q2A and the third main control sensor Q1A, so as to precisely limit the relative circumferential phase difference between the two sensor probes and the radial gap between each of them and the tooth tip of the trigger signal ring 2.

[0084] like Figure 6 As shown, in this embodiment, the tooth pitch CJ of the trigger signal ring 2 is 25.22mm, so we take 1 / 4 tooth pitch, approximately 6.3mm.

[0085] During operation: First, insert the probe of the fourth main control sensor Q2A into the first semi-circular slot 41;

[0086] Next, screw the positioning bolt 44 on the mounting through hole 43 at one end of the positioning body 4 into the tooth groove of the trigger signal ring 2, which is closest to the probe axis of the fourth main control sensor Q2A, so that the positioning body 4 can be reliably locked in place.

[0087] Next, adjust the probe end face of the fourth main control sensor Q2A so that it just contacts the bottom surface of the first semi-circular slot 41 of the positioning body 4. At this time, the gap between the probe of the fourth main control sensor Q2A and the tooth tip of the trigger signal ring 2 is precisely guaranteed by the distance between the bottom surface of the first semi-circular slot 41 and the inner arc surface of the arc strip, and controlled between 1mm and 2.1mm. Then, lock the back cap of the fourth main control sensor Q2A.

[0088] Remove the positioning body 4 and positioning bolt 44, move the positioning body 4 to the third main control sensor Q1A and use the positioning bolt 44 to engage the tooth groove of the signal transmitting ring 2;

[0089] Finally, insert the probe of the third master control sensor Q1A into the second semi-circular slot 42, and adjust the probe of the third master control sensor Q1A so that its end face contacts the bottom surface of the second semi-circular slot 42. At this time, the positions of the third master control sensor Q1A and the fourth master control sensor Q2A ensure the precise relationship of (n+3 / 4) ×CJ. Tighten the back cap of the third master control sensor Q1A, and the position adjustment of the master control sensor group is completed.

[0090] Step S5: Phase difference adjustment of the third redundant sensor Q1B and the fourth redundant sensor Q2B;

[0091] The adjustment steps for the redundant sensor group are the same as those for the main control group, only the reference phase is different. First, rotate the sensor to a 45° position. At this point, the probe centerline of the second main control sensor MSA should coincide with the starting end face of the inner semicircular ring 11 of the flywheel. Using this as a reference, sequentially fix the positions of the fourth redundant sensor Q2B and the third redundant sensor Q1B using assembly fixtures, ensuring that their relative positions also maintain a phase difference of (n+3 / 4) × CJ, and that the end face gap meets the requirements.

[0092] Step S6: Overall functional verification;

[0093] After all mechanical adjustments are completed, rotate the engine again and verify each signal group using the MOP interface or indicator lights. Check the angle encoder function according to Table 1. Start the diesel engine and wait for the main unit to stabilize at approximately 50% load. Perform the PMI 0-diagram calibration to measure the actual dead-point offset (Triger A offset ahead) of the main encoder A and input it into the control system. Finally, observe the Tacho Alignment Deviation parameter through the MOP interface to confirm that its displayed value is close to 0° and the Delta Tacho B deviation is within the allowable range (±1°). The adjustment is now complete.

[0094] like Figure 7 , Figure 8 As shown: The assembly fixture also includes a detachable handle, which is connected to the other end of the positioning body 4 via a snap-fit ​​structure. The snap-fit ​​structure at one end of the handle matches the shape of the positioning body 4 and is made of elastic material. The snap-fit ​​structure at one end of the handle engages with and securely connects to the other end of the positioning body 4, used for positioning the assembly fixture in confined spaces. The other end of the handle has a grip for holding. Table 1: Inspection Angle Encoder Function Operation Table

[0095]

[0096] Top dead center (TDC) is the position of the piston in the cylinder of a diesel engine when it reaches its highest position. For cylinder #1 of a diesel engine, this position is marked as 0°. The TDC of other cylinders varies depending on the number of cylinders and the firing order of the diesel engine. For example, in a 6-cylinder engine with a firing order of 1-5-3-4-2-6, the TDC of cylinder #5 is 60°, cylinder #3 is 120°, and so on.

[0097] The purpose of PMI 0-diagram calibration is to reduce the fuel injection quantity of each cylinder to 0 in sequence, so that no more fuel is injected and burned in the cylinder to do work, leaving only compression pressure, thereby calculating the actual top dead center angle position of each cylinder.

[0098] Delta Tacho B is the deviation of the actual angle between the redundant group angle encoder and the main control group angle encoder.

[0099] Triger A offset ahead is the deviation between the actual 0° measured by the master angle encoder after the diesel engine is running and the theoretical cylinder angle before the diesel engine is running.

[0100] Tacho Alignment Deviation is the deviation between the theoretical angle and the actual angle of the entire angle encoder system.

[0101] When the engine is running at about 50% load, after PMI system TDC calibration, the TDC of each cylinder is the actual value measured by the system. Input the Triger A offset ahead angle value measured by the system into the main control system. It must be within ±1° range. If it exceeds the range, the TDC of the angle encoder needs to be readjusted. At this time, the Tacho Alignment Deviation of angle encoders A and B on the MOP interface should show about 0°.

[0102] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An assembly fixture for an angle encoder at the output end of a marine diesel engine, characterized in that, include: The positioning body (4) is an arc-shaped positioning body, which includes an arc-shaped part and a straight part that are perpendicular to each other, and its cross-section is T-shaped. The arc section has an arc-shaped structure; the inner and outer arc surfaces of the arc section are coaxial and parallel to each other; the straight section has a flat thin plate structure; one end of the arc section is provided with a first semi-circular slot (41) and a second semi-circular slot (42) for respectively fitting and engaging with the probes of the fourth main control sensor Q2A and the third main control sensor Q1A of the angle encoder at the output end of the marine diesel engine; the axis of the first semi-circular slot (41) and the axis of the second semi-circular slot (42) are both perpendicular to the outer arc surface of the arc section; The other end of the arc section is provided with a mounting through hole (43); the axis of the mounting through hole (43) is perpendicular to the arc surface of the arc section; a positioning bolt (44) is inserted into the mounting through hole (43), and the positioning bolt (44) is used to screw into the tooth groove of the trigger signal ring (2) of the angle encoder at the output end of the marine diesel engine, so as to realize the detachable positioning connection between the assembly tooling and the trigger signal ring (2); The first semicircular slot (41) and the second semicircular slot (42) are blind holes; the distance between the bottom surface of the first semicircular slot (41) and the bottom surface of the second semicircular slot (42) and the inner arc surface of the arc strip is equal to the distance between the probe end face of the fourth main control sensor Q2A, the probe end face of the third main control sensor Q1A and the tooth tip of the trigger signal ring (2), respectively, so as to limit the radial gap between the probe end face of the fourth main control sensor Q2A, the probe end face of the third main control sensor Q1A and the tooth tip of the trigger signal ring (2) of the marine diesel engine output angle encoder; The distance S between the axis of the first semicircular slot (41) and the axis of the second semicircular slot (42) satisfies: S = (n + 3 / 4) × CJ, where n is a non-negative integer and CJ is the tooth pitch of the trigger signal loop (2); The assembly fixture engages with the toothed groove of the trigger signal ring (2) via the positioning bolt (44) and sequentially engages the probe of the fourth main control sensor Q2A and the probe of the third main control sensor Q1A, so as to precisely limit the relative circumferential phase difference between the two sensor probes and the radial gap between each of them and the tooth tip of the trigger signal ring (2).

2. The assembly fixture for a marine diesel engine output angle encoder according to claim 1, characterized in that, The diameters of the first semicircular slot (41) and the second semicircular slot (42) are respectively matched with the diameters of the probes of the fourth main control sensor Q2A and the third main control sensor Q1A, forming a clearance fit, so that the sensor probes can be freely inserted or withdrawn.

3. The assembly fixture for a marine diesel engine output angle encoder according to claim 1, characterized in that, The bottom surface of the first semicircular slot (41) and the bottom surface of the second semicircular slot (42) are arc surfaces coaxial with the trigger signal ring (2), and their arc radius is greater than the tooth tip circle radius of the trigger signal ring (2).

4. The assembly fixture for a marine diesel engine output angle encoder according to claim 1, characterized in that, The head of the positioning bolt (44) is provided with an internal hexagonal hole and its end is a smooth rod, which is used to insert into the bottom of the tooth groove of the trigger signal ring (2) and at the same time ensure that the tooling can be finely adjusted along the tooth groove direction of the trigger signal ring (2) before being locked.

5. The assembly fixture for a marine diesel engine output angle encoder according to claim 1, characterized in that, The thickness of the flat thin plate structure of the positioning body (4) is 4mm-6mm. The flat thin plate structure is used to fit the tooth tip circle surface of the trigger signal ring (2) during assembly to provide support.

6. The assembly fixture for a marine diesel engine output angle encoder according to claim 1, characterized in that, The assembly fixture also includes a detachable hand handle, which is connected to the other end of the positioning body (4) via a snap-fit ​​structure, for gripping and positioning the assembly fixture in a confined space.

7. The assembly fixture for a marine diesel engine output angle encoder according to claim 1, characterized in that, The assembly fixture is made of wear-resistant metal material and its surface is treated with anti-rust treatment. The inner walls and bottom surfaces of the first semi-circular slot (41) and the second semi-circular slot (42) are all polished.

8. The assembly fixture for a marine diesel engine output angle encoder according to claim 1, characterized in that, The positioning body (4) is provided with a direction mark, which is used to indicate that the tooling is facing the fuel side (110) when it is installed.

9. A method for adjusting the angle encoder at the output end of a marine diesel engine, characterized in that, The assembly fixture using the marine diesel engine output angle encoder according to any one of claims 1 to 8 includes the following steps: Step S1: Perform a circular runout check on the inner semicircular ring (11) and the outer semicircular ring (12) of the flywheel (1) installed on one side of the flywheel to ensure that their circular runout tolerance is <0.5mm and mark their highest point; Step S2: Perform a circular runout check on the trigger signal loop (2) to ensure that its circular runout tolerance is <0.5mm, and mark its highest point; Step S3: Rotate the machine to the 0° position and adjust the position of the first main control sensor MMA so that the distance between the end face of the probe of the first main control sensor MMA and the outer wall of the inner semicircular ring (11) of the flywheel is 2mm-4mm. Ensure that the central axis of the probe of the first main control sensor MMA coincides with the end face of the starting end of the inner semicircular ring (11) of the flywheel and is perpendicular to the ring surface of the inner semicircular ring (11) of the flywheel. Rotate the wheel to the 45° position and adjust the position of the second main control sensor MSA so that the distance between the end face of the probe of the second main control sensor MSA and the outer wall of the inner semicircular ring (11) of the flywheel is 2mm-4mm. Ensure that the central axis of the probe of the second main control sensor MSA coincides with the end face of the starting end of the inner semicircular ring (11) of the flywheel and is perpendicular to the ring surface of the inner semicircular ring (11) of the flywheel. Rotate the wheel to the 90° position and adjust the probe of the first main control sensor MMA so that the distance between the end face of the probe of the first main control sensor MMA and the outer wall of the outer semicircular ring (12) of the flywheel is 2mm-4mm. Ensure that the central axis of the probe of the first main control sensor MMA coincides with the end face of the starting end of the outer semicircular ring (12) of the flywheel and is perpendicular to the ring surface of the outer semicircular ring (12) of the flywheel. Rotate the wheel to the 135° position, adjust the probe of the second redundant sensor MSB so that the distance between the end face of the probe of the second redundant sensor MSB and the outer wall of the outer semicircular ring (12) of the flywheel is 2mm-4mm, and ensure that the central axis of the probe of the second redundant sensor MSB coincides with the end face of the starting end of the outer semicircular ring (12) of the flywheel and is perpendicular to the ring surface of the outer semicircular ring (12) of the flywheel. Step S4: Use the assembly fixture of the marine diesel engine output angle encoder to position and adjust the probe of the fourth main control sensor Q2A and the probe of the third main control sensor Q1A. Rotate the machine to 0° and insert the probe of the fourth main control sensor Q2A into the first semi-circular slot (41) of the positioning body (4); Screw the positioning bolt (44) on the mounting through hole (43) into the tooth groove of the trigger signal ring (2) closest to the probe axis of the fourth main control sensor Q2A, so that it can be locked in place. Adjust the probe end face of the fourth main control sensor Q2A to just contact the bottom surface of the first semi-circular slot (41), and ensure that the positioning body (4) can be freely pulled out. After adjusting the position of the fourth main control sensor Q2A, lock it in place with its back cap. Remove the positioning body (4) and positioning bolt (44), move the positioning body (4) to the third main control sensor Q1A and use the positioning bolt (44) to lock the tooth groove of the signal ring (2); Fine-tune the probe of the third master control sensor Q1A so that it can be freely inserted into the second semi-circular slot (42) on the positioning body (4), which is equivalent to the relative position between the third master control sensor Q1A and the fourth master control sensor Q2A being an integer number of trigger signal ring (2) tooth pitches plus 3 / 4 tooth pitches. Adjust the probe end face of the third main control sensor Q1A to just contact the bottom surface of the second semi-circular slot (42), and ensure that the positioning body (4) can be freely pulled out. Then lock the back cap of the third main control sensor Q1A. At this point, the position adjustment of the third main control sensor Q1A and the fourth main control sensor Q2A is completed. Step S5: Use the assembly fixture of the marine diesel engine output angle encoder to position and adjust the probe of the fourth redundant sensor Q2B and the probe of the third redundant sensor Q1B. Rotate the wheel to 45°. At this time, the central axis of the probe of the second main control sensor MSA coincides with the end face of the starting end of the inner semicircular ring (11) of the flywheel. Insert the probe of the fourth redundant sensor Q2B into the first semi-circular slot (41) of the positioning body (4); Screw the positioning bolt (44) on the mounting through hole (43) into the tooth groove of the trigger signal ring (2) so that the positioning bolt (44) is properly locked in the assembly fixture. Adjust the probe end face of the fourth redundant sensor Q2B to just contact the bottom surface of the first semi-circular slot (41), and ensure that the positioning body (4) can be freely pulled out. After adjusting the position of the fourth redundant sensor Q2B, lock it in place with its back cap. Remove the positioning body (4) and positioning bolt (44), move the positioning body (4) to the third redundant sensor Q1B and use the positioning bolt (44) to lock the tooth groove of the signal ring (2); Fine-tune the probe of the third redundant sensor Q1B so that it can be freely inserted into the second semi-circular slot (42) on the positioning body (4), so that the relative position between the third redundant sensor Q1B and the fourth redundant sensor Q2B is separated by an integer number of trigger signal ring (2) tooth pitch plus 3 / 4 tooth pitch. Adjust the probe end face of the third redundant sensor Q1B to just contact the bottom surface of the second semi-circular slot (42), and ensure that the positioning body (4) can be freely pulled out. Then lock the back cap of the third redundant sensor Q1B. At this point, the position adjustment of the third redundant sensor Q1B and the fourth redundant sensor Q2B is completed. Step S6: Rotate the machine around once to verify the trigger range of each probe signal, ensuring that the light is on within the specified angle and there is no trigger signal at other positions.

10. The method for adjusting the angle encoder at the output end of a marine diesel engine according to claim 9, characterized in that, In step S2, the circular runout of the trigger signal ring (2) is checked using a dial indicator. If the circular runout is greater than 0.5 mm, the outer circle of the trigger signal ring (2) needs to be machined. In step S3, the probe of the first master control sensor MMA is adjusted when the crankshaft is rotated to 0°, so that the distance between the end face of the probe of the first master control sensor MMA and the outer wall of the inner semicircular ring (11) of the flywheel is 3mm; the probe of the first master control sensor MMA is adjusted when the crankshaft is rotated to 90°, so that the distance between the end face of the probe of the first master control sensor MMA and the outer wall of the outer semicircular ring (12) of the flywheel is 3mm, ensuring that it can detect signals in the range of 90° to 270° to assist in determining the crankshaft position; the probe of the second master control sensor MSA is adjusted when the crankshaft is rotated to 45°, so that the distance between the end face of its probe and the outer wall of the inner semicircular ring (11) of the flywheel is 3mm, covering the signal range of 45° to 225°; the probe of the second redundant sensor MSB is adjusted when the crankshaft is rotated to 135°, so that the distance between the end face of its probe and the outer wall of the outer semicircular ring (12) of the flywheel is 3mm, covering the signal range of 135° to 315°.

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