Non-magnetic base meter testing fixture

Abstract

The utility model relates to the technical field of measurement and testing. A non-magnetic base meter testing fixture comprises an upper shell and a cylindrical surface located below the upper shell, the upper shell and the cylindrical surface are of an integrated structure, a limiting convex face is arranged below the upper shell, the cylindrical surface is of a hollow structure, the upper shell and the limiting convex face are provided with circular detection through holes axially penetrating through the upper shell and the limiting convex face, and a positioning pin is arranged at the bottom of the cylindrical surface. The problems of difficulty in detection and low production efficiency in the prior art are solved, and the purposes of quickly detecting the abnormality of the movement positioning structure and identifying the position deviation of the signaling pointer of the non-magnetic base meter are achieved.

Description

Technical Field

[0001] This utility model relates to the field of measurement and testing technology, and in particular to the measurement of length, thickness or similar linear dimensions. Background Technology

[0002] A non-magnetic water meter is a pulse-sampling mechanical water meter based on eddy current technology. Its pointer, which carries a metal strip and induces a resistance damping effect, is generally called the signal pointer. Non-magnetic water meters use pulse sampling for electromechanical conversion, requiring real-time sampling and the ability to retain pulse signals. Therefore, the alignment requirements between the electronic sampling module and the signal pointer in a non-magnetic water meter are very high. However, the position of the signal pointer is not only related to the attached mechanism components but also to the mating parts of the mechanism components, namely the water meter casing. The position of the signal pointer within the mechanism components is determined by the plastic mold and is generally fixed and consistent. After the mechanism components are installed into the water meter casing to form the base meter, due to assembly gaps and tightening forces, displacement of the mechanism components, along with the signal pointer, is very likely to occur. The abnormal position of the signal pointer caused by this displacement is not easily detected with conventional measuring tools. The sampling abnormality is only discovered in the later stages of assembly, requiring rework, which is time-consuming, labor-intensive, and inefficient. Especially on fully automatic water meter assembly lines, such problems can cause a complete line shutdown. For example, Chinese Patent Publication No. CN202182681U discloses an inspection tool, providing the following technical solution: This utility model discloses an inspection tool including a base. The base has several positioning blocks that mate with the surface of a product. The base also has several threaded installation inspection holes corresponding to the mounting holes on the product, and positioning pin inspection holes corresponding to the positioning pin holes on the product. The base has at least two guide pillars, on which a top cover and a top pad are movably mounted sequentially. The top cover and the top pad are connected by bolts, and a mounting positioning pin is provided between the top cover and the top pad. The top cover has an irregular through hole that mates with the shape of the product. The top pad has an inspection hole corresponding to the inner hole of the product, and an inspection post is movably mounted within the inspection hole. A bottom pad is provided under the base plate, and a mounting positioning pin is provided between the base and the bottom pad. The bottom pad has through holes corresponding to the installation inspection holes and positioning pin inspection holes. This inspection tool can conveniently inspect whether the shape of the product and the positions of each mounting hole and connecting hole are qualified. However, the aforementioned inspection tool cannot be applied to the testing of non-magnetic water meters, and it only checks whether the product's shape and the positions of the mounting holes and connection holes are qualified, making it difficult to conduct a comprehensive test like this utility model. Utility Model Content

[0003] This invention solves the problems of difficulty in detection and low production efficiency in the prior art, and proposes a non-magnetic base watch inspection tool, which achieves the purpose of quickly detecting abnormalities in the movement positioning structure and identifying the position deviation of the signal pointer in a non-magnetic base watch.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A non-magnetic base gauge includes an upper shell and a cylindrical surface located below the upper shell. The upper shell and the cylindrical surface are integrally formed. A limiting protrusion is provided below the upper shell. The cylindrical surface is a hollow structure. The upper shell and the limiting protrusion are provided with a circular detection through hole that axially penetrates both. A positioning pin is provided at the bottom of the cylindrical surface.

[0006] The integrated structure enhances the overall rigidity and stability of the fixture, avoids assembly errors from separate parts, and the axially through-hole allows direct observation of the signal pointer position. The positioning pin enables rapid and accurate alignment between the base gauge and the fixture.

[0007] Preferably, the circular detection through-hole is funnel-shaped, with the top being the maximum allowable circle and the bottom being the reference circle. The maximum allowable circle and the reference circle are concentric circles, and the diameter of the maximum allowable circle is larger than the diameter of the reference circle.

[0008] The funnel-shaped through-hole forms a visual guidance channel, allowing operators to quickly determine the pointer offset by comparing concentric circles; the maximum permissible circle covers the qualified area within the tolerance range, and the reference circle serves as the baseline circle. The difference in diameter between the two quantifies the permissible deviation value, enabling rapid visual judgment.

[0009] Preferably, the bottom of the positioning pin is provided with a guide protrusion, and the connection between the cylindrical surface and the positioning pin is provided with a root-reinforcing frustum.

[0010] The guide protrusion can guide the positioning pin to automatically correct and insert into the positioning hole of the electronic module, reducing the time for manual alignment; the root-reinforcing truncated cone enhances the positioning pin's resistance to bending through a thickened structure, avoiding root breakage caused by repeated insertion and removal.

[0011] Preferably, the limiting convex surface is circular, and its diameter is smaller than that of the cylindrical surface.

[0012] The physical limiting boundary is formed by the diameter difference between the limiting convex surface and the center circle of the middle cover, which prevents the gauge from being pressed too much into the base gauge and causing pointer deformation.

[0013] Preferably, the inner wall of the cylindrical surface is evenly distributed with several vertical inner limiting ribs.

[0014] The inner limiting ribs form multi-point contact limiting with the outer cylindrical surface of the middle cover, dispersing assembly pressure and avoiding single-point deformation. The evenly distributed ribs can automatically correct the eccentricity of the movement components and improve the coaxiality accuracy of the gauge and the base gauge.

[0015] Preferably, the bottom of the inner limiting rib is provided with a guide slope.

[0016] The guide ramp provides a progressive guiding effect during the installation of movement components, reducing assembly resistance. The ramp structure can compensate for case machining errors and guide the movement components to automatically slide into the correct testing position.

[0017] Preferably, the upper shell is circular, the diameter of the upper shell is larger than the diameter of the cylindrical surface, and a hand-held inclined surface is provided between the upper shell and the cylindrical surface.

[0018] The circular upper shell and the beveled handle are ergonomically designed for easy one-handed gripping and force application. The stepped structure formed by the difference in diameter prevents the gauge from slipping accidentally, improving operational safety.

[0019] Preferably, the lower surface of the limiting convex surface is a flat plane with a flatness tolerance of no more than 0.1 mm.

[0020] The high-precision plane ensures that the limiting convex surface fits perfectly with the upper surface of the glass, eliminating detection errors caused by uneven contact surfaces, and allowing the gauge to be reused thousands of times while maintaining stable detection accuracy.

[0021] Compared with the prior art, the beneficial effects of this utility model are as follows.

[0022] 1. This utility model achieves precise positioning and detection of the signal transmitter pointer's position through a positioning pin, inner limiting rib, and guiding surface, solving the pointer offset problem caused by case machining errors or assembly gaps in traditional assembly. It significantly reduces manual measurement errors and improves detection efficiency. This design not only enhances the accuracy of single-tests but also reduces uncontrollable factors in the production process through standardized procedures, ensuring the high-precision alignment of the electromechanical conversion module and the signal transmitter pointer in the non-magnetic water meter, thereby improving overall production efficiency.

[0023] 2. The precise fit between the positioning pin and the positioning hole of the electronic module in this invention reduces the difficulty and time cost of manual calibration. This highly reliable structural design, combined with the anti-magnetic interference characteristics of the non-magnetic water meter itself, extends the service life of the equipment and reduces the frequency of maintenance.

[0024] 3. This utility model enhances rigidity and detection stability through an integrated structure. The hollow cylindrical surface and funnel-shaped detection through-hole enable rapid visual identification of the signal pointer. The guide protrusion and root reinforcement design of the positioning pin ensure accurate alignment and bending resistance. The limiting protrusion and inner limiting rib correct the movement eccentricity problem through physical limiting and multi-point contact. The guiding slope and hand-held slope optimize assembly guidance and operational safety. High-precision planar tolerance control ensures long-term detection reliability. The overall design solves the pointer offset problem caused by machining errors and assembly gaps in the base gauge, significantly improving detection efficiency, reducing rework rate, adapting to the needs of automated production lines, extending the life of the inspection tool, and reducing maintenance costs. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of one embodiment of a non-magnetic base gauge according to the present invention.

[0026] Figure 2 This is a top view of a non-magnetic base meter testing fixture according to an embodiment of the present invention, showing the base meter testing fixture during non-magnetic base meter testing.

[0027] Figure 3 This is a half-sectional view of a non-magnetic base meter testing fixture according to an embodiment of the present invention, showing the base meter testing fixture being used in conjunction with a non-magnetic base meter.

[0028] Illustration:

[0029] Non-magnetic base watch 3, center circle of the middle cover 3-1, upper plane of the watch glass 3-2, outer cylindrical surface of the middle cover 3-3, signal pointer 3-4, base watch gauge 4, upper shell 4-1, circular detection through hole 4-1-1, maximum allowable circle 4-1-2, reference circle 4-1-3, limiting convex surface 4-1-4, handheld inclined surface 4-1-5, cylindrical surface 4-2, positioning pin 4-3, guide protrusion 4-3-1, root reinforcing frustum 4-3-2, inner limiting rib 4-4, guide inclined surface 4-4-1. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings. The proportions of the components are not drawn to scale, and the proportions and dimensions shown in the drawings should not limit the essential technical solutions of this utility model. These embodiments do not exhaustively describe all details, nor do they limit this utility model to merely the specific embodiments described.

[0031] See Figures 1 to 3 As shown, a non-magnetic base meter inspection tool includes an upper shell 4-1 and a cylindrical surface 4-2 located below the upper shell 4-1. The upper shell 4-1 and the cylindrical surface 4-2 are integrally formed. A limiting convex surface 4-1-4 is provided below the upper shell 4-1. The cylindrical surface 4-2 is a hollow structure. The upper shell 4-1 and the limiting convex surface 4-1-4 are provided with a circular detection through hole 4-1-1 that axially penetrates both. A positioning pin 4-3 is provided at the bottom of the cylindrical surface 4-2.

[0032] like Figure 1 In one embodiment shown, Figure 1This is a schematic diagram of one embodiment of a non-magnetic base meter inspection fixture according to the present invention. The non-magnetic base meter inspection fixture 4 is mainly used to detect whether the position of the transmitting pointer 3-4 in the non-magnetic base meter 3 is qualified. The core structure of the fixture includes an upper shell 4-1 and a hollow cylindrical surface 4-2 integrally formed therewith, avoiding assembly errors through an integrated design. A limiting convex surface 4-1-4, smaller in diameter than the cylindrical surface 4-2, is provided below the upper shell 4-1 for matching and limiting the position of the center circle 3-1 of the middle cover of the non-magnetic base meter 3. An axially penetrating circular detection through hole 4-1-1 is provided between the upper shell 4-1 and the limiting convex surface 4-1-4. This through hole is funnel-shaped, with the top being the maximum allowable circle 4-1-2 and the bottom being the reference circle 4-1-3. These two circles are concentric, with the maximum allowable circle 4-1-2 having a larger diameter, forming a visual deviation judgment channel. The bottom of the cylindrical surface 4-2 is provided with a positioning pin 4-3, which has a guide protrusion 4-3-1 at the bottom to guide the positioning pin 4-3 into the electronic module positioning hole 1-3 of the base table 3; the root of the positioning pin 4-3 is reinforced with a frustum 4-3-2 to enhance its bending resistance.

[0033] Multiple vertical inner limiting ribs 4-4 are evenly distributed on the inner wall of the cylindrical surface 4-2, and a guide slope 4-4-1 is provided at its bottom to guide the movement components into the correct position during assembly. The upper shell 4-1 is circular with a diameter larger than that of the cylindrical surface 4-2, and the two are connected by a hand-held slope 4-1-5 for easy gripping and operation. The lower surface of the limiting convex surface 4-1-4 is a high-precision flat surface with a flatness of ≤0.1mm, ensuring complete contact with the upper surface 3-2 of the watch glass of the base watch 3. During inspection, the operator positions the inspection tool 4 through the cooperation of the inner limiting ribs 4-4 and the outer cylindrical surface 3-3 of the middle cover, so that the positioning pin 4-3 is inserted into the positioning hole of the base watch 3 until the limiting convex surface 4-1-4 is flush with the upper surface 3-2 of the watch glass. At this time, the signal pointer 3-4 should be within the maximum allowable circle 4-1-2. The product's qualification is determined by comparing the center distance between the signal pointer 3-4 and the reference circle 4-1-3.

[0034] In another embodiment, the base gauge has an upper shell, a cylindrical surface, a locating pin, and an inner limiting rib. The upper shell has a detection hole, a maximum allowable circle, a reference circle, and a limiting protrusion, and a hand-held inclined surface between it and the cylindrical surface; the locating pin is located outside the cylindrical surface, with a guide protrusion at the top and a reinforcing protrusion at the base; the inner limiting rib is located on the inner surface of the cylindrical surface, and a guide surface is provided at its lower end.

[0035] This utility model device achieves efficient, accurate, and stable detection functions. Its core advantage lies in the comprehensive application of mechanical limiting and high-precision manufacturing technologies, systematically solving the problem of abnormal position of the signal pointer 3-4 in traditional non-magnetic watches caused by case processing errors, assembly gaps, or human operation deviations. Specifically, the integrated upper shell 4-1 and cylindrical surface 4-2 are rigidly connected to avoid the cumulative errors of separate assembly. At the same time, the hollow cylindrical surface 4-2 design reduces the weight of the inspection tool and provides the operator with a window for intuitive observation of the signal pointer 3-4. Combined with the axially penetrating funnel-shaped circular detection through-hole 4-1-1, a visual guidance channel is formed from the maximum allowable circle 4-1-2 to the reference circle 4-1-3. The operator does not need to rely on complex instruments; they only need to visually check whether the signal pointer 3-4 falls completely within the reference circle 4-1-3 to quickly determine the pass rate. This visual judgment mechanism reduces the detection time from minutes to seconds with traditional tools, which is especially suitable for the high-speed requirements of automated production lines.

[0036] The guide protrusion 4-3-1 at the bottom of the positioning pin 4-3 works in concert with the reinforcing frustum 4-3-2 at the root. The former automatically corrects the alignment deviation between the positioning pin 4-3 and the positioning hole 1-3 of the electronic module of the base watch 3 through the inclined surface or arc structure, significantly reducing the frequency of manual adjustment. The latter improves the bending resistance of the positioning pin 4-3 through local thickening, so that it can maintain its structural integrity during multiple insertion and removal operations, thereby extending the service life of the inspection tool to several times that of traditional designs. The diameter of the limiting protrusion 4-1-4 is smaller than that of the cylindrical surface 4-2. Through the difference in diameter with the center circle 3-1 of the middle cover, a rigid physical limit is formed. This prevents the inspection tool from being over-pressed in, which could cause deformation of the signal pointer 3-4 or breakage of the upper surface 3-2 of the watch glass. It can also accommodate the error fluctuations in the processing of the watch case of the base watch 3, avoiding detection interruptions caused by dimensional deviations. The evenly distributed vertical inner limiting ribs 4-4 on the inner wall of the cylindrical surface 4-2 disperse the assembly pressure of the movement components through multi-point contact, eliminating the risk of local deformation caused by single-point force. At the same time, the guide slope 4-4-1 at its bottom provides a progressive guiding effect when the movement components are installed. Even if there is a slight misalignment in the case positioning structure, it can still guide the components to automatically slide into the correct position, greatly improving the assembly success rate. The circular design of the upper case 4-1 and the hand-held slope 4-1-5 between it and the cylindrical surface 4-2 conform to ergonomic principles, allowing the operator to easily complete the entire set of actions of gripping, aligning, and pressing down. The stepped structure formed by the difference in diameter further prevents the inspection tool from accidentally slipping. Compared with the cumbersome process of traditional inspection tools, this design reduces the time spent on a single inspection operation and significantly reduces the risk of inspection interruption or equipment damage caused by tool drops.

[0037] The flatness tolerance of the lower surface of the limiting convex surface 4-1-4 is strictly controlled to ≤0.1mm, ensuring complete fit with the upper surface 3-2 of the meter glass. This eliminates the reference tilt error caused by uneven contact surfaces. Combined with the quantitative design of the diameter difference between the maximum allowable circle 4-1-2 and the reference circle 4-1-3, the detection accuracy is stabilized within ±0.1mm, meeting the core technical requirement of zero pulse signal loss in non-magnetic water meters. In actual production, this invention can significantly reduce the rework rate of the base meter 3 after assembly, greatly increasing the daily detection volume of a single automated production line. Furthermore, due to its high repeatability, the gauge does not require calibration after continuous use. Compared to traditional gauges that require manual verification after a short number of uses, its overall maintenance cost is significantly reduced. From a technical extensibility perspective, the dual-circle judgment mechanism of this gauge can be adapted to various models of base meters 3 by replacing the detection through holes 4-1-1 with different diameter ratios. The number and distribution angle of the inner limiting ribs 4-4 can be adjusted according to structural flexibility, demonstrating strong process compatibility.

[0038] like Figure 2 and Figure 3 In one embodiment shown, Figure 2 This is a top view of the non-magnetic base meter testing fixture and the non-magnetic base meter testing process, according to one embodiment of the present invention. Figure 3 This is a half-sectional view of a non-magnetic base watch inspection fixture according to an embodiment of this utility model, showing the fixture in conjunction with a non-magnetic base watch. During base watch positioning and inspection, after horizontally placing the base watch 3, hold the inclined surface 4-1-5 by hand. The inner limiting rib 4-4, under the action of the guiding inclined surface 4-4-1, covers the outer cylindrical surface 3-3 of the inner cover. The positioning pin 4-3, guided by the guiding protrusion 4-3-1, is inserted into the positioning hole 1-3 of the electronic module. The cylindrical surface of the limiting protrusion 4-1-4 mates with the cylindrical surface of the center circle 3-1 of the inner cover for positioning, until the limiting protrusion 4-1-4 is flush with the upper plane 3-2 of the watch glass. At this point, the base watch inspection fixture 4 is in place. In this embodiment, manual judgment is used. If the outer circle of the signal pointer 3-4 falls within the maximum allowable circle 4-1-2, it is considered to meet the usage requirements and is allowed to pass; otherwise, it is judged as unqualified. In another embodiment, the judgment can be made by existing image recognition technology. The software automatically captures the center of the reference circle 4-1-3 and the signal pointer 3-4 and measures the distance between the centers. When the distance between the centers is not greater than the set threshold, it is judged as qualified and a qualified icon is displayed; otherwise, a prominent unqualified icon is displayed.

[0039] This invention significantly improves the efficiency, accuracy, and reliability of detecting the position of the signal pointer 3-4 through the precise matching design of the base watch fixture 4 and the non-magnetic base watch 3. Specifically, after placing the base watch 3 horizontally, the operator holds the handheld inclined surface 4-1-5 and wraps the inner limiting rib 4-4 around the outer cylindrical surface 3-3 of the middle cover along the guide inclined surface 4-4-1. With the gradual guiding effect of the guide inclined surface 4-4-1, the offset of the movement components caused by the case machining tolerance or assembly gap can be automatically corrected, ensuring that the coaxiality error between the inner limiting rib 4-4 and the outer cylindrical surface 3-3 of the middle cover is small. At the same time, when the guide protrusion 4-3-1 at the bottom of the positioning pin 4-3 is inserted into the positioning hole 1-3 of the electronic module, the conical or arc-shaped structure... Compensation for assembly alignment deviations ensures that the clearance between the positioning pin 4-3 and the positioning hole 1-3 is controlled within ±0.05mm, avoiding time-consuming manual adjustments. The limiting convex surface 4-1-4 and the cylindrical surface of the center circle 3-1 of the middle cover are matched for limiting, and the high-precision flatness of its lower surface and the upper plane 3-2 of the dial glass is ≤0.1mm, forming a double mechanical limit. This not only prevents the gauge 4 from being over-pressed in, causing deformation of the signal pointer 3-4, but also ensures that the detection reference surface is consistent with the actual working plane of the base dial 3, eliminating the risk of misjudgment caused by tilting.

[0040] In the manual judgment embodiment, the operator can visually compare the outer circle of the maximum permissible circle 4-1-2 with the outer circle of the signal pointer 3-4 to complete the pass / fail determination in just a few seconds, without the need for complex measuring tools. This is especially suitable for rapid sampling inspection scenarios in small production lines. The diameter design of the maximum permissible circle 4-1-2 covers twice the tolerance range of the permissible offset of the signal pointer 3-4, which ensures the judgment error tolerance rate and avoids the metrological risks caused by excessive relaxation of standards. In the image recognition embodiment, the software automatically captures the center distance between the reference circle 4-1-3 and the signal pointer 3-4, and combines it with a preset threshold to achieve accurate digital judgment. Compared with manual visual inspection, this will improve the detection accuracy. At the same time, the automatic generation function of pass and fail icons can record the detection results in real time and generate statistical reports, which is convenient for quality traceability and process optimization. The compatible design of the two judgment modes not only meets the stringent requirements of high-precision fully automated production lines but also adapts to the flexible operation of low-cost semi-automated production lines. Especially with the collaborative positioning mechanism of the inner limit rib 4-4 and the positioning pin 4-3, even if the base gauge has machining errors or assembly gaps in the outer cylindrical surface 3-3 of the inner cover, the compensation effect of the guide slope 4-4-1 and the guide protrusion 4-3-1 ensures that the detection error of the signal transmitter pointer 3-4 is ≤0.05mm, thereby significantly reducing the pulse signal loss rate caused by positional offset. Furthermore, a single fixture can adapt to the detection needs of various base gauge models; cross-model compatibility can be achieved simply by adjusting the diameter ratio of the reference circle 4-1-3 to the maximum permissible circle 4-1-2, significantly reducing fixture development and maintenance costs.

[0041] In summary, this utility model provides a non-magnetic watch inspection tool 4. Through the integrated design of the upper shell 4-1 and hollow cylindrical surface 4-2, combined with innovative structures such as the limiting convex surface 4-1-4, the funnel-shaped circular detection through-hole 4-1-1, and the positioning pin 4-3, it systematically solves the problem of pointer 3-4 offset in non-magnetic watches 3 caused by case machining errors or assembly gaps. Specifically, the integrated molding process of the upper shell 4-1 and cylindrical surface 4-2 eliminates assembly errors and improves overall rigidity; the axially penetrating funnel-shaped detection through-hole 4-1-1 has a maximum allowable circle 4-1-2 at the top and a reference circle 4-1-3 at the bottom. Both are concentric, and their diameter difference quantifies the allowable deviation value. The operator can visually determine whether the pointer 3-4 falls within the reference circle 4-1-3 within a few seconds, significantly improving inspection efficiency compared to traditional tools. The guide protrusion 4-3-1 at the bottom of the positioning pin 4-3 automatically corrects the alignment deviation with the positioning hole 1-3 of the electronic module of the base watch 3. Combined with the anti-bending design of the root-reinforced frustum 4-3-2, this significantly improves the insertion and removal lifespan. The vertical inner limiting ribs 4-4 evenly distributed on the inner wall of the cylindrical surface 4-2 disperse assembly pressure through multi-point contact. The guide slope 4-4-1 at its bottom compensates for case machining errors and corrects the eccentricity of the movement components. The limiting protrusion 4-1-4, with a diameter smaller than the cylindrical surface 4-2, forms a rigid limit through the diameter difference with the center circle 3-1 of the inner cover, preventing excessive pressing that could deform the signal pointer 3-4. Its lower surface flatness tolerance ≤0.1mm ensures complete fit with the upper surface 3-2 of the watch glass, eliminating tilt errors. The ergonomic design of the circular upper shell 4-1 and the hand-held slope 4-1-5 makes single-handed operation convenient and non-slip, adapting to the high-frequency requirements of automated production lines. In practical applications, this inspection tool is compatible with both manual visual inspection and image recognition modes: in manual mode, the maximum allowable circle is 4-1-2 to ensure the fault tolerance rate; in image mode, higher accuracy is achieved through the circle center distance threshold, which greatly increases the daily inspection volume. The modular design supports adaptation to multiple base meter models, significantly reducing maintenance costs and providing core technical support for the large-scale production of non-magnetic water meters.

[0042] This utility model is not limited to the above-described embodiments. Any changes made to its shape or material composition, as long as the structural design provided by this utility model is adopted, are considered a variation of this utility model and should be regarded as within the protection scope of this utility model.

Claims

1. A non-magnetic base gauge, characterized in that, It includes an upper shell (4-1) and a cylindrical surface (4-2) located below the upper shell (4-1). The upper shell (4-1) and the cylindrical surface (4-2) are integrally formed. A limiting convex surface (4-1-4) is provided below the upper shell (4-1). The cylindrical surface (4-2) is a hollow structure. The upper shell (4-1) and the limiting convex surface (4-1-4) are provided with a circular detection through hole (4-1-1) that axially penetrates both of them. A positioning pin (4-3) is provided at the bottom of the cylindrical surface (4-2).

2. The non-magnetic base gauge according to claim 1, characterized in that, The upper shell (4-1) is provided with a reference circle (4-1-3). The circular detection through hole (4-1-1) is funnel-shaped, with the top being the maximum allowable circle (4-1-2) and the bottom being the reference circle (4-1-3). The maximum allowable circle (4-1-2) and the reference circle (4-1-3) are concentric circles, and the diameter of the maximum allowable circle (4-1-2) is larger than the diameter of the reference circle (4-1-3).

3. A non-magnetic base gauge according to claim 1 or 2, characterized in that, The bottom of the positioning pin (4-3) is provided with a guide protrusion (4-3-1), and the cylindrical surface (4-2) is provided with a root reinforcing frustum (4-3-2) at the connection between the positioning pin (4-3).

4. The non-magnetic base gauge according to claim 1, characterized in that, The limiting convex surface (4-1-4) is circular, and its diameter is smaller than that of the cylindrical surface (4-2).

5. A non-magnetic base gauge according to claim 3, characterized in that, The inner wall of the cylindrical surface (4-2) is evenly distributed with several vertical inner limiting ribs (4-4).

6. A non-magnetic base gauge according to claim 5, characterized in that, The bottom of the inner limiting rib (4-4) is provided with a guide slope (4-4-1).

7. A non-magnetic base gauge according to claim 5 or 6, characterized in that, The upper shell (4-1) is circular, and the diameter of the upper shell (4-1) is larger than the diameter of the cylindrical surface (4-2). A hand-held inclined surface (4-1-5) is provided between the upper shell (4-1) and the cylindrical surface (4-2).

8. A non-magnetic base gauge according to claim 6, characterized in that, The lower surface of the limiting convex surface (4-1-4) is a flat plane with a flatness tolerance of no more than 0.1 mm.

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