An adjustable engine crankshaft to camshaft sensor gap measurement tool

Abstract

The application discloses a kind of adjustable engine crankshaft and camshaft sensor gap measurement frock, including positioning clamping mechanism, measurement adjusting mechanism and limit protection mechanism;Positioning clamping mechanism is configured as the depth of sensor flange reference surface to sensor probe end surface;Measurement adjusting mechanism is configured as the total depth of sensor flange reference surface to gear ring top surface;The total depth of flange reference surface to gear ring top surface is subtracted from the depth difference of flange reference surface to sensor probe end surface, and the precise value of air gap is directly obtained by the way of double scale accurate reading, difference calculation, and the measurement error is far lower, can accurately match standard air gap interval requirement, reduce the fault such as engine idle speed jitter, acceleration powerless, misfire, fault light bright and unable to start caused by gap exceeding standard.

Description

Technical Field

[0001] This invention relates to the field of engine component installation technology, and specifically to an adjustable engine crankshaft and camshaft sensor clearance measurement fixture. Background Technology

[0002] Crankshaft and camshaft sensors are core precision detection components of the engine electronic control system. They are mainly used to collect crankshaft speed, angle, and camshaft phase signals in real time, providing core data support for the engine ECU to accurately control fuel injection timing, ignition timing, and valve timing, directly determining engine starting performance, power output, and fuel economy. The installation air gap between the sensor probe and the signal gear ring is a critical assembly parameter. The standard gap range for mainstream models is 0.4~1.8mm. The accuracy of the air gap value directly affects the stability and accuracy of signal acquisition. If the gap is too large, it will lead to weak sensor signals and signal distortion; if the gap is too small, it will easily cause interference and wear between the probe and the gear ring, resulting in many problems such as engine idling vibration, weak acceleration, misfire, and constant malfunction indicator lamp illumination. In severe cases, it can even prevent the engine from starting normally, significantly reducing the overall assembly quality and operational reliability.

[0003] Currently, in engine production line assembly and after-sales maintenance, the measurement of crankshaft / camshaft sensor clearances generally employs traditional manual measuring tools, with two main methods. The first is standard feeler gauge kit measurement, which relies on single feeler gauges of varying thicknesses, manually inserted into the gap between the sensor mounting hole and the signal gear ring. The gap size is determined through trial insertion, and this is currently the most widely used method. The second is a fixed-thickness integrated gauge, which uses a single gauge of standard thickness to determine whether the current clearance is within the acceptable range, achieving qualitative screening of clearance compliance.

[0004] The two types of traditional measuring tools mentioned above are simple in structure and low in cost, and can meet the basic gap detection needs. However, they have many inherent defects in precision assembly, multi-model adaptation and mass production operation scenarios. They generally suffer from low measurement accuracy, lack of direct numerical reading function, easy damage to parts, poor versatility and low operation efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide an adjustable engine crankshaft and camshaft sensor clearance measurement fixture to overcome the above-mentioned shortcomings in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An adjustable engine crankshaft and camshaft sensor clearance measuring fixture includes a positioning clamping mechanism, a measuring adjustment mechanism, and a limit protection mechanism;

[0008] The positioning and clamping mechanism is configured to measure the depth from the sensor flange reference surface to the sensor probe end face;

[0009] The measurement adjustment mechanism is configured to measure the total depth from the reference surface of the sensor flange to the top surface of the gear ring.

[0010] The air gap is the difference between the total depth from the flange reference surface to the top surface of the gear ring and the depth difference from the flange reference surface to the end face of the sensor probe.

[0011] Preferably, the positioning and clamping mechanism includes a positioning and clamping plate and a movable clamping piece, which cooperate to clamp the sensor flange.

[0012] Preferably, it also includes a main measuring rod, which is fixedly connected to a movable clamping piece. The main measuring rod is provided with a main scale, and a scale sleeve is slidably provided on the main measuring rod. When the scale sleeve contacts the end face of the sensor probe, the reading value of the scale sleeve and the main scale is the depth from the flange reference surface to the end face of the sensor probe.

[0013] Preferably, the measurement and adjustment mechanism includes an extension rod slidably mounted on the main measuring rod. The extension rod is provided with a scale, and a measuring head is fixedly mounted on the extension rod. The measuring head extends into the sensor mounting hole. When the measuring head contacts the top surface of the gear ring, the extension scale of the extension rod is read, which is the total depth from the flange reference surface to the top surface of the gear ring.

[0014] Preferably, a simulation block is fixedly installed on the main measuring rod. The simulation block is used to simulate the sensor mounting flange. When the measuring head contacts the top surface of the gear ring, the simulation block abuts against the entrance of the sensor mounting hole.

[0015] Preferably, the limiting and protective mechanism includes an abutment pin slidably disposed on the main measuring rod, the abutment pin being in contact with the extension rod;

[0016] An elastic element is provided between the abutment pin and the main measuring rod.

[0017] Preferably, the elastic element is a spring, and the two ends of the spring are fixedly connected to the abutment pin and the main measuring rod, respectively.

[0018] Preferably, the positioning clamping plate is provided with a rectangular clearance groove.

[0019] Preferably, both the positioning clamping plate and the movable clamping piece are provided with anti-slip textures, and the anti-slip textures abut against the two sides of the sensor flange.

[0020] Preferably, the scale sleeve is provided with anti-slip texture, and the anti-slip texture abuts against the end face of the sensor probe.

[0021] The adjustable engine crankshaft and camshaft sensor clearance measuring fixture provided by the present invention has the following advantages in the above technical solutions:

[0022] 1. The precise air gap value is obtained directly through dual-scale accurate reading and difference calculation. The measurement error is much lower, which can accurately match the standard air gap range requirements and reduce faults such as engine idling vibration, weak acceleration, misfire, malfunction light illumination and inability to start caused by excessive gap.

[0023] 2. No need for repeated trial insertions and comparisons. Two sets of depth parameters can be directly read through the scales of the main measuring rod and the extension rod. The air gap value can be obtained by simple difference calculation. At the same time, it supports adding or removing shims in place after measurement and checking the gap in real time, which greatly shortens the time for gap detection and adjustment of a single set of sensors.

[0024] 3. The limit protection mechanism achieves sliding limit and buffer protection, eliminating hard interference and squeezing wear between the probe and the signal tooth ring and sensor hole wall during the measurement process, avoiding damage to parts caused by improper operation, and reducing equipment wear and maintenance costs.

[0025] 4. It adopts an adjustable structure with sliding clamping and telescopic measurement, which can be adapted to crankshaft and camshaft sensors of different specifications and flange sizes. It breaks through the shortcomings of traditional fixed gauges that can only be adapted to a single model and feeler gauges that have limited compatibility, and greatly improves the versatility of tooling.

[0026] 5. This fixture can independently complete the entire process of sensor clamping and positioning, working condition simulation, data reading, air gap calculation, gasket adjustment, and gap re-inspection using a single device. Its functions are highly integrated, requiring no auxiliary tools, effectively simplifying the testing process, reducing manual operation steps, and avoiding alignment deviations and operational errors caused by switching between multiple tools.

[0027] It should be understood that the foregoing general description and the following detailed description are exemplary and illustrative only, and are not intended to limit this disclosure.

[0028] This application provides an overview of various implementations or examples of the technology described in this disclosure, and is not a full disclosure of the entire scope or all features of the disclosed technology. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0030] Figure 1 This is a schematic diagram of the overall structure provided for an embodiment of the present invention;

[0031] Figure 2 This is an overall side sectional view provided for an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the abutment pin structure provided in an embodiment of the present invention.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Positioning clamping plate; 11. Simulation block; 2. Movable clamping piece; 3. Scale sliding sleeve; 4. Main measuring rod; 401. Main scale; 5. Measuring head; 6. Extension rod; 7. Locking screw; 8. Abutment pin; 81. Spring; 9. Anti-slip texture; 101. Rectangular clearance groove. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0036] Please refer to 1-3. An adjustable engine crankshaft and camshaft sensor gap measuring fixture includes a positioning and clamping mechanism, a measurement and adjustment mechanism, and a limit protection mechanism. The positioning and clamping mechanism is configured to measure the depth from the sensor flange reference surface to the sensor probe end face. The measurement and adjustment mechanism is configured to measure the total depth from the sensor flange reference surface to the top surface of the gear ring. The difference between the total depth from the flange reference surface to the top surface of the gear ring and the depth from the flange reference surface to the sensor probe end face is the air gap. The sensor flange reference surface is a unified measurement reference. The positioning and clamping mechanism accurately measures the "depth from the flange reference surface to the sensor probe end face," and the measurement and adjustment mechanism accurately measures the "total depth from the flange reference surface to the top surface of the gear ring." Using the difference between the total depth and the probe end face depth, the actual installation air gap between the sensor probe and the signal gear ring is accurately calculated. Combined with the limit protection mechanism, the measurement process is ensured to be safe and stable, thus constructing a core architecture for accurate quantitative measurement of the air gap and realizing accurate quantification of the air gap value. The three mechanisms work together to balance measurement accuracy, operational stability, and component protection, effectively reducing problems such as low measurement accuracy, lack of quantified data, and easy damage to parts.

[0037] Specifically, the positioning and clamping mechanism includes a positioning clamping plate 1 and a movable clamping piece 2. The positioning clamping plate 1 and the movable clamping piece 2 work together to clamp the sensor flange. The positioning and clamping mechanism is composed of the positioning clamping plate 1 and the movable clamping piece 2 and adopts a bidirectional clamping structure. The fixed positioning clamping plate 1 is attached to one side of the sensor flange, and the sliding movable clamping piece 2 is attached to the other side of the flange, so as to achieve overall clamping and positioning of the sensor flange. This achieves rapid positioning and stable clamping of the sensor flange, effectively avoiding measurement reference deviation caused by sensor offset and shaking during the measurement process, ensuring the reference consistency of two depth measurements, and greatly improving the accuracy of air gap calculation. At the same time, the split clamping structure can be adapted to sensor flanges of different thicknesses and widths, initially improving the tooling adaptability.

[0038] It also includes a main measuring rod 4, which is fixedly connected to the movable clamping piece 2. The main measuring rod 4 is provided with a main scale 401, and a scale sleeve 3 is slidably provided on the main measuring rod 4. When the scale sleeve 3 contacts the end face of the sensor probe, the reading value of the scale sleeve 3 and the main scale 401 is the depth from the flange reference surface to the end face of the sensor probe. In this embodiment, the main measuring rod 4 and the movable clamping piece 2 are fixed as one piece to ensure that the clamping positioning and the measurement reference are synchronized. The main measuring rod 4 is provided with a main scale 401, and the scale sleeve 3 can slide freely along the main measuring rod 4. During measurement, the scale sleeve 3 is attached to the end face of the sensor probe. With the flange reference surface as the zero point, the accurate depth value is directly read through the main scale 401, which is the depth from the flange reference surface to the end face of the sensor probe. The integrated fixed structure eliminates the reference misalignment error between clamping and measurement. The scale sliding structure is adapted to sensors with different probe extension lengths to ensure the accuracy and stability of the measurement data.

[0039] Specifically, the measurement and adjustment mechanism includes an extension rod 6 slidably mounted on the main measuring rod 4. The extension rod 6 has a scale, and a measuring head 5 is fixedly mounted on it. The measuring head 5 extends into the sensor mounting hole. When the measuring head 5 contacts the top surface of the gear ring, the extension rod 6's protrusion scale is read, which represents the total depth from the flange reference surface to the top surface of the gear ring. The scaled extension rod 6 is slidably mounted on the main measuring rod 4, and the measuring head 5 is fixed at the end of the extension rod 6. During measurement, the measuring head 5 extends into the sensor mounting hole and fits against the top surface of the signal gear ring. Relying on the scale markings on the extension rod 6, and using the flange reference surface as a reference, the total depth from the flange reference surface to the top surface of the gear ring is directly read. Combined with the probe depth value of claim 3, the air gap is accurately calculated through the difference. This achieves accurate quantitative reading of the reference depth of the gear ring top surface, and, in conjunction with the dual-scale measurement system, completes accurate quantitative calculation of the air gap. The slidable and telescopic structure of the extension rod 6 adapts to sensor mounting holes of different depths and gear ring mounting positions of different models, solving the problem of poor versatility of traditional fixed gauges. Simultaneously, the telescopic structure is easy to operate, effectively improving the efficiency of the inspection operation.

[0040] A simulation block 11 is fixedly mounted on the main measuring rod 4. The simulation block 11 is used to simulate the sensor mounting flange. When the measuring head 5 contacts the top surface of the gear ring, the simulation block 11 abuts against the entrance of the sensor mounting hole. The simulation block 11, which simulates the sensor mounting flange, is fixedly mounted on the main measuring rod 4. During measurement, after the measuring head 5 is in contact with the top surface of the gear ring, the simulation block 11 abuts against the entrance of the sensor mounting hole, accurately simulating the flange fit state after the sensor is actually assembled, locking the measurement reference position, and avoiding excessive insertion of the tooling or positional deviation during the measurement process. This accurately reproduces the actual assembly condition of the sensor, eliminates measurement errors caused by improper tooling insertion depth or reference deviation, and further improves the accuracy of air gap measurement.

[0041] In a further embodiment of the present invention, the limiting and protective mechanism includes an abutment pin 8 slidably disposed on the main measuring rod 4, the abutment pin 8 being in contact with the extension rod 6; an elastic element is disposed between the abutment pin 8 and the main measuring rod 4, the abutment pin 8 being slidably disposed on the main measuring rod 4 and being able to abut with the extension rod 6, and the elastic element is assembled between the abutment pin 8 and the main measuring rod 4, the elastic tension of the elastic element is used to achieve adaptive fitting of the abutment pin 8, and the sliding stroke of the extension rod 6 is elastically limited, thereby achieving buffering and positioning during the extension and retraction process of the extension rod 6.

[0042] The limiting and protective mechanism consists of a sliding abutment pin 8 and an elastic element. The abutment pin 8 is slidably mounted on the main measuring rod 4 and forms an abutment with the extension rod 6. Relying on the elastic preload of the elastic element, it forms a flexible clamping limit on the extension rod 6 under normal conditions, restricting the free sliding amount of the extension rod 6 and ensuring that the position of the extension rod 6 is stable and does not move during the measurement state. When the measuring head 5 is inserted into the sensor mounting hole and accidentally contacts the hole wall, the gear ring, or encounters significant resistance, the extension rod 6 can overcome the preload of the elastic element and push the abutment pin 8 in the opposite direction, compressing the elastic element to achieve adaptive retraction. This provides a controllable retraction stroke for the extension rod 6, thereby buffering the hard contact pressure and avoiding rigid collisions. On the one hand, the elastic and flexible limiting structure effectively limits the shaking, offset, and movement of the extension rod 6 during operation, ensuring the accuracy of scale reading and measurement stability, and improving the consistency of test data. On the other hand, it has a passive retraction protection function. When there is a measurement alignment deviation, hole wall interference, or excessive resistance to the gear ring tightening, the elastic retraction can release the buffer stroke to avoid hard squeezing, bumping, and rigid contact between the measuring head 5, the extension rod 6, the inner wall of the sensor mounting hole, and the signal gear ring. This completely eliminates the problems of scratches, deformation, and wear of parts, achieving non-destructive measurement, while effectively protecting the tooling structure and extending the tooling service life.

[0043] Furthermore, the elastic element is a spring 81. Both ends of the spring 81 are fixedly connected to the abutment pin 8 and the main measuring rod 4, respectively. As an elastic element, the spring 81, with its two ends fixedly connected to the abutment pin 8 and the main measuring rod 4, utilizes its elastic properties to provide a stable elastic clamping force to the abutment pin 8, achieving flexible abutment limiting when the extension rod 6 slides. The spring 81 is also used as a dedicated elastic buffer reset component. With both ends fixedly connected to the abutment pin 8 and the main measuring rod 4, the spring 81, relying on its elastic extension properties, continuously provides a constant elastic preload to the abutment pin 8 under normal conditions, ensuring that the abutment pin 8 always fits against the extension rod 6, achieving stable flexible limiting. When the measuring head 5 encounters resistance and the extension rod 6 is compressed and retracted, the spring 81 can stably compress and deform to provide clearance. After the resistance disappears, the elastic reset of the spring 81 can quickly return the abutment pin 8 and the extension rod 6 to their initial limiting state, ensuring subsequent continuous measurement operations.

[0044] Furthermore, a rectangular clearance groove 101 is provided on the positioning clamping plate 1. The rectangular clearance groove 101 is opened on the positioning clamping plate 1. Relying on the hollow structure of the clearance groove, the protruding structure, wire harness connector, mounting bolt and other interference structures around the sensor flange are avoided, so as to ensure that the clamping plate can completely fit the reference surface of the sensor flange.

[0045] Both the positioning clamping plate 1 and the movable clamping piece 2 are provided with anti-slip textures 9, which abut against the two sides of the sensor flange. The scale sliding sleeve 3 is also provided with anti-slip textures 9, which abut against the end face of the sensor probe. The anti-slip textures 9 on the clamping contact surfaces of the positioning clamping plate 1 and the movable clamping piece 2 increase the contact friction with the two sides of the sensor flange. During clamping operations, the anti-slip textures 9 ensure tight contact with the flange surface, preventing relative sliding or displacement between the sensor flange and the clamping plate / piece during measurement, thus ensuring proper clamping. To maintain positioning stability, anti-slip textures 9 are provided on the contact end face of the scale sleeve 3. During measurement, the anti-slip textures 9 are in close contact with the end face of the sensor probe, increasing the friction of the contact surface and preventing relative slippage between the scale sleeve 3 and the end face of the probe. The flexible anti-slip textures 9 have both a high coefficient of friction and flexible buffering characteristics. During measurement, they can fit tightly against the end face of the sensor probe, and the large friction force prevents the scale sleeve 3 from slipping. At the same time, the flexible material can adapt to the fine morphology of the end face of the probe. Even if a small amount of relative slippage occurs during operation, it will not produce hard friction and scratches, avoiding damage to the precision probe end face.

[0046] The sensor mounting holes and gear rings mentioned in this invention are internal structures of the engine and are existing technologies. Their structural features are common knowledge to those skilled in the art and will not be described in detail.

[0047] Working principle: The positioning clamping plate 1 is attached to one side of the sensor mounting flange, the sliding movable clamping piece 2 is used to clamp the other side of the flange, and the locking screw 7 is tightened to make it abut against the main measuring rod 4, thus completing the fixation between the positioning clamping plate 1 and the movable clamping piece 2. The anti-slip texture 9 improves the clamping stability and prevents the sensor mounting flange from slipping. The measuring head 5 is pulled out and the extension rod 6 is slid, and the spring 81 and the abutment pin 8 are used for abutment and limit. The measuring head 5 is inserted into the sensor mounting hole of the engine by pushing the main measuring rod 4 until the end face of the measuring head 5 is attached to the tooth top of the signal gear ring. The pushing continues and the flange simulation block 11 abuts against the entrance of the sensor mounting hole. The depth from the flange reference surface to the sensor probe end face is read through the observation window of the graduated sliding sleeve 3. The main measuring rod 4 is then retracted slightly, and the value on the extension rod 6 is read using the analog block 11 as a reference. This value represents the total depth from the flange reference surface to the top surface of the gear ring. Subtracting the depth difference between the flange reference surface and the sensor probe end face from this total depth directly yields the real-time air gap value between the sensor probe end face and the gear ring. Simultaneously, while maintaining the tooling state, installation shims are added or removed from the extension rod 6 according to the read gap value. These shims compensate for the contact between the analog block 11 and the sensor mounting hole inlet. The gap is then checked again until the value meets the standard range. When installing the sensor, a shim of the same specification is installed at the sensor flange to ensure the proper air gap between the sensor probe and the signal gear ring after sensor installation.

[0048] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. An adjustable engine crankshaft and camshaft sensor clearance measuring fixture, characterized in that, This includes a positioning and clamping mechanism, a measuring and adjusting mechanism, and a limit protection mechanism; The positioning and clamping mechanism is configured to measure the depth from the sensor flange reference surface to the sensor probe end face; The measurement adjustment mechanism is configured to measure the total depth from the reference surface of the sensor flange to the top surface of the gear ring. The air gap is the difference between the total depth from the flange reference surface to the top surface of the gear ring and the depth difference from the flange reference surface to the end face of the sensor probe.

2. The adjustable engine crankshaft and camshaft sensor clearance measuring fixture according to claim 1, characterized in that, The positioning and clamping mechanism includes a positioning clamping plate (1) and a movable clamping piece (2), which cooperate to clamp the sensor flange.

3. The adjustable engine crankshaft and camshaft sensor clearance measuring fixture according to claim 2, characterized in that, It also includes a main measuring rod (4), which is fixedly connected to the movable clamping piece (2). The main measuring rod (4) is provided with a main scale (401), and a scale sleeve (3) is slidably provided on the main measuring rod (4). When the scale sleeve (3) contacts the end face of the sensor probe, the reading value of the scale sleeve (3) and the main scale (401) is the depth from the flange reference surface to the end face of the sensor probe.

4. The adjustable engine crankshaft and camshaft sensor clearance measuring fixture according to claim 3, characterized in that, The measurement and adjustment mechanism includes an extension rod (6) that is slidably mounted on the main measuring rod (4). The extension rod (6) is provided with a scale. A measuring head (5) is fixedly mounted on the extension rod (6). The measuring head (5) extends into the sensor mounting hole. When the measuring head (5) contacts the top surface of the gear ring, the extension scale of the extension rod (6) is read, which is the total depth from the flange reference surface to the top surface of the gear ring.

5. The adjustable engine crankshaft and camshaft sensor clearance measuring fixture according to claim 4, characterized in that, A simulation block (11) is fixedly installed on the main measuring rod (4). The simulation block (11) is used to simulate the sensor mounting flange. When the measuring head (5) contacts the top surface of the gear ring, the simulation block (11) abuts against the entrance of the sensor mounting hole.

6. The adjustable engine crankshaft and camshaft sensor clearance measuring fixture according to claim 4, characterized in that, The limiting and protective mechanism includes an abutment pin (8) that is slidably disposed on the main measuring rod (4), and the abutment pin (8) is in contact with the extension rod (6); An elastic element is provided between the abutment pin (8) and the main measuring rod (4).

7. The adjustable engine crankshaft and camshaft sensor clearance measuring fixture according to claim 6, characterized in that, The elastic element is a spring (81), and the two ends of the spring (81) are fixedly connected to the abutment pin (8) and the main measuring rod (4) respectively.

8. The adjustable engine crankshaft and camshaft sensor clearance measuring fixture according to claim 2, characterized in that, The positioning clamping plate (1) is provided with a rectangular clearance groove (101).

9. The adjustable engine crankshaft and camshaft sensor clearance measuring fixture according to claim 2, characterized in that, Both the positioning clamping plate (1) and the movable clamping piece (2) are provided with anti-slip textures (9), and they abut against the two sides of the sensor flange through the anti-slip textures (9).

10. The adjustable engine crankshaft and camshaft sensor clearance measuring fixture according to claim 3, characterized in that, The scale slide (3) is provided with anti-slip texture (9), and the anti-slip texture (9) abuts against the end face of the sensor probe.

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