A micro-aperture measurement mechanism

Abstract

The utility model discloses a kind of micro aperture measuring mechanism, comprising: fixed axle seat and floating plate, fixed axle seat is fixedly connected with fixed base plate by strut, flat bearing is sleeved on fixed axle seat, floating plate is sleeved on fixed axle seat by flat bearing, and floating gap is left between the outer diameter of fixed axle seat and the inner hole of floating plate, so that floating plate is floated in horizontal plane relative to fixed axle seat, floating plate is connected with connecting rod, connecting rod is connected with connecting plate, contact type displacement sensor is installed on connecting plate, measuring head and the detection end transmission connection of contact type displacement sensor, floating plate is floated in horizontal plane when being subjected to radial force with measuring head, to automatically compensate the position deviation between the measured hole and measuring head;By the above mode, the utility model can be automatically aligned measuring head and measured hole by horizontal floating, avoid collision and ensure measurement accuracy.

Description

Technical Field

[0001] This utility model relates to the field of aperture measurement technology, and in particular to a micro aperture measurement mechanism. Background Technology

[0002] In fields such as new energy vehicles and precision machinery, components like motor housings have numerous mounting holes requiring high-precision control. To ensure the assembly accuracy and performance of the entire machine, the measurement of these holes' diameter, position, symmetry, and other geometric tolerances is crucial. However, many of these holes are located in narrow and deep cavities, posing a significant challenge to automated measurement.

[0003] Currently, there are several mainstream methods for measuring this type of space: First, manual inspection tools are used. Although this method is low-cost, the inspection process is cumbersome, inefficient, and heavily reliant on the operator's experience. Repeatability and accuracy are difficult to guarantee, making it unsuitable for the batch and real-time inspection needs of production lines.

[0004] Second, non-contact optical measurement is used. Although this method solves the efficiency problem, its core optical sensor is expensive and is sensitive to the environment (such as oil, vibration, and light). Its long-term stability and measurement accuracy are sometimes difficult to match those of robust and reliable mechanical contact measurement.

[0005] Third, employ a mechanical automated measuring mechanism. This is currently the most ideal solution. Mature, dedicated probes (such as the "M1STAR™ Internal Diameter Measuring Instrument") based on the lever principle to convert radial dimensional changes into axial displacement are already available on the market, solving the problem of arranging sensors in confined spaces. However, such automated measuring solutions still have a significant technical bottleneck: to ensure measurement accuracy and probe safety, it is necessary to ensure that the central axis of the probe is highly aligned with the theoretical axis of the hole being measured. In actual production, due to factors such as workpiece machining errors, fixture positioning errors, and repeatability errors of the mechanical system, there is a slight deviation between the actual and theoretical positions of the hole being measured. If the measuring mechanism is rigidly mounted, during high-speed, batch testing, this micron-level positional deviation can easily cause the probe to fail to insert smoothly, or even collide with the hole opening, resulting in probe damage, inaccurate measurement data, and seriously affecting the reliability and stability of automated testing. Utility Model Content

[0006] The main technical problem solved by this utility model is to provide a miniature aperture measuring mechanism that can automatically align the probe with the hole being measured by horizontal floating, avoiding collisions and ensuring measurement accuracy.

[0007] To solve the above-mentioned technical problems, the present invention provides a micro-aperture measuring mechanism, comprising: a fixed shaft seat and a floating plate. The fixed shaft seat is fixedly connected to a fixed base plate via a support rod. A plane bearing is sleeved on the fixed shaft seat. The floating plate is sleeved on the fixed shaft seat via the plane bearing. A floating gap is left between the outer diameter of the fixed shaft seat and the inner hole of the floating plate, so that the floating plate floats in the horizontal plane relative to the fixed shaft seat. The floating plate is connected to a connecting rod, and the connecting rod is connected to a connecting plate. A contact displacement sensor is installed on the connecting plate. The probe is drivenly connected to the detection end of the contact displacement sensor. When the probe is subjected to radial force, the floating plate floats in the horizontal plane to automatically compensate for the positional deviation between the measured hole and the probe.

[0008] Preferably, a disc spring and a locking nut are provided on the fixed shaft seat. The disc spring is located between the plane bearing and the locking nut. The disc spring is locked by the locking nut. Under the pressure of the locking nut, the disc spring provides axial elastic preload to the floating plate and the plane bearing.

[0009] Preferably, the planar bearing includes a first planar bearing and a second planar bearing, which are respectively arranged on both sides of the floating plate. The first planar bearing is arranged between the floating plate and the base of the fixed bearing seat, and the second planar bearing is arranged between the disc spring and the floating plate.

[0010] Preferably, a first washer is arranged on one side of the disc spring, and the first washer is arranged between the second planar bearing and the disc spring.

[0011] Preferably, a second washer is arranged on the other side of the disc spring, and the second washer is arranged between the locking nut and the disc spring.

[0012] Preferably, the connecting plate has a mounting hole, the contact displacement sensor is installed in the mounting hole, the connecting plate has a threaded hole communicating with the mounting hole, a locking screw extending into the mounting hole is provided in the threaded hole, a copper sleeve is provided between the contact displacement sensor and the mounting hole, and the locking screw fixes the contact sensor in the mounting hole of the connecting plate by tightening the copper sleeve.

[0013] Preferably, it also includes a driving device, which, together with a fixed base plate, is used to drive the probe to move along its axial direction.

[0014] The beneficial effects of this invention are as follows: By using a floating plate, a plane bearing, and a fixed shaft seat, traditional rigid measurement is transformed into flexible measurement with adaptive capabilities. When there is a slight positional deviation between the probe and the measured hole, the radial force applied by the hole opening to the probe can drive the entire floating measurement assembly to smoothly translate and float in the horizontal plane, achieving automatic centering. This fundamentally avoids the risk of rigid collision between the probe and the hole opening, effectively protecting the precision probe. Simultaneously, the pre-tightening structure using a combination of disc springs and locking nuts completely eliminates axial movement clearance and ensures the stability of the axial dimensional chain. Finally, this mechanism, combined with the drive device, achieves complete automation of the measurement process. This not only significantly improves detection efficiency and shortens the measurement cycle time, but also, with its high repeatability, high reliability, and excellent stability, is particularly suitable for online, batch automated production lines, solving the long-standing problem of automated measurement of precision hole diameters in confined spaces. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is the front view of this utility model; Figure 3 This is a cross-sectional view of the present invention; Figure 4 yes Figure 3 Enlarged schematic diagram of section A in the middle.

[0016] The components in the attached diagram are labeled as follows: 1. Fixed base plate; 2. Fixed shaft seat; 21. Disc spring; 22. Locking nut; 23. Support rod; 3. Floating plate; 31. Connecting rod; 4. Connecting plate; 41. Threaded hole; 42. Locking screw; 43. Copper sleeve; 5. Contact displacement sensor; 61. First planar bearing; 62. Second planar bearing; 71. First gasket; 72. Second gasket; 8. Probe. Detailed Implementation

[0017] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0018] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0020] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0021] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0022] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0023] Unless otherwise specified, physical quantities in formulas should be understood as basic quantities of SI base units, or derived quantities derived from basic quantities through mathematical operations such as multiplication, division, differentiation, or integration.

[0024] Example: refer to Figures 1-4 A miniature aperture measuring mechanism includes a fixed bearing 2 and a floating plate 3. A fixed base plate 1 serves as the mounting foundation for the entire mechanism. The fixed bearing 2 is rigidly connected to the fixed base plate 1 via a strut 23, forming a stable support frame. The floating plate 3 is fitted onto the fixed bearing 2 through its inner hole, with a small gap between them. This gap ensures that the floating plate 3 does not lock up, thus providing physical space for floating. To make the translation of the floating plate 3 more stable and smooth in the horizontal plane relative to the axis of the fixed bearing 2, the floating plate 3 is fitted onto the fixed bearing 2 via a planar bearing. The planar bearing is precisely installed on the fixed bearing 2 and assembled with the floating plate 3, allowing the floating plate 3 to smoothly translate in any direction within the horizontal plane perpendicular to the axis of the fixed bearing 2.

[0025] refer to Figures 1-4 A floating plate 3 is connected to a connecting rod 31, which in turn is connected to a connecting plate 4. A contact displacement sensor 5 is mounted on the connecting plate 4. The probe 8 is connected to the detection end of the contact displacement sensor 5, thus forming a floating whole with the connecting plate 4, the contact displacement sensor 5 and the probe 8 mounted on it, and the floating plate 3. When the probe 8 is subjected to radial force, the floating plate 3 floats in the horizontal plane to automatically compensate for the positional deviation between the measured hole and the probe 8.

[0026] refer to Figures 1-4When the probe 8 approaches the hole under the drive of the drive device, if there is a positional deviation, the edge of the hole will apply a radial force to the probe 8. This radial force is transmitted to the floating plate 3 through the connecting plate 4 and the connecting rod 31, forcing the floating assembly to slide on the plane bearing until the axis of the probe 8 is aligned with the axis of the hole, thus smoothly guiding it into the hole. This floating process automatically compensates for positional deviations caused by workpiece positioning, fixture errors, etc., thereby transforming the traditional rigid measuring mechanism into a flexible measuring mechanism with adaptive capabilities. It can automatically eliminate micron-level positional errors accumulated during installation and positioning, fundamentally avoiding the risk of rigid collision between the probe 8 and the hole, effectively protecting the expensive precision probe 8. At the same time, it ensures that every measurement is performed when the probe 8 and the hole are in optimal alignment, laying a solid foundation for obtaining highly repeatable and reliable measurement data, making it particularly suitable for high-speed, batch automated production lines.

[0027] refer to Figures 1-4 A disc spring 21 and a locking nut 22 are provided on the fixed shaft seat 2. The disc spring 21 is sleeved on the fixed shaft seat 2 and installed between the plane bearing and the locking nut 22. The disc spring 21 is locked by the locking nut 22. Under the pressure of the locking nut 22, the disc spring 21 provides axial elastic preload to the floating plate 3 and the plane bearing. This compresses all the components (including the plane bearing, floating plate 3, disc spring 21, etc.) mounted on the fixed shaft seat 2. As a precision elastic element, the disc spring 21 is compressed under the pressure of the locking nut 22, thereby generating a continuous and stable reverse axial elastic preload.

[0028] refer to Figures 1-4 The cooperation between the disc spring 21 and the locking nut 22 completely eliminates the axial movement clearance of the floating plate 3 and its plane bearing, ensuring the stability of the axial dimensional chain during measurement. Furthermore, compared to purely rigid locking, the elastic characteristics of the disc spring 21 avoid the risk of crushing the plane bearing balls due to excessive tightening, ensuring that the floating plate 3 can still move flexibly and smoothly in the horizontal plane while bearing enormous axial driving forces. In addition, the disc spring 21 can automatically compensate for the minute gaps caused by wear over long-term use, ensuring the accuracy and stability of the mechanism during long-term use.

[0029] refer to Figures 2-4The planar bearings are arranged symmetrically, specifically including a first planar bearing 61 and a second planar bearing 62. The first and second planar bearings 61 and 62 are respectively attached to both sides of the floating plate 3. The first planar bearing 61 is attached between the floating plate 3 and the base of the fixed bearing 2, meaning it is located below the floating plate 3 and directly contacts the base of the fixed bearing 2. The second planar bearing 62 is attached between the disc spring 21 and the floating plate 3, meaning it is located above the floating plate 3. Thus, the floating plate 3 is precisely clamped between these two planar bearings. This symmetrical support structure ensures that the floating plate 3 receives a uniform and stable support reaction force when subjected to radial force from any direction. As a preferred embodiment, a shallow annular positioning groove can be machined on the upper and lower surfaces of the floating plate 3 where it contacts the first and second planar bearings 61 and 62, allowing the outer ring of the planar bearing to be partially embedded in these grooves.

[0030] refer to Figures 2-4 The symmetrical arrangement of two planar bearings, one above the other, significantly improves the rigidity and stability of the floating plate 3 during movement. This effectively resists the overturning moment caused by uneven force on the probe 8, preventing the floating plate 3 from jamming or warping, and ensuring smooth translational movement within the horizontal plane. The positioning grooves on the floating plate 3 provide precise radial positioning of the planar bearings, preventing accidental radial movement or rotation during operation, further enhancing the overall repeatability and long-term reliability of the floating system.

[0031] refer to Figure 3 and Figure 4 A first washer 71 is arranged on one side of the disc spring 21, between the second plane bearing 62 and the disc spring 21. A second washer 72 is arranged on the other side of the disc spring 21, between the lock nut 22 and the disc spring 21. The first washer 71 and the second washer 72 are usually made of wear-resistant materials such as hardened steel, and their surfaces are finely ground to achieve a high degree of smoothness. The first washer 71 evenly transmits the concentrated preload generated by the disc spring 21 to the outer ring of the second plane bearing 62, while preventing the end face of the disc spring 21 from directly rubbing against the bearing ring. The second washer 72 isolates the rotating lock nut 22 from the disc spring 21. When the nut is tightened, the washer rotates with it, while the disc spring 21 remains stationary, preventing the nut from scratching or torsional deforming the surface of the disc spring 21.

[0032] refer to Figure 3 and Figure 4The first shim 71 and the second shim 72, though small components, play a crucial role in protection and optimizing force transmission. As wear-resistant media, they effectively prevent precision components such as the disc spring 21 and the plane bearing from being scratched or dented during preload and operation, extending their service life. Simultaneously, they ensure that the axial preload is applied evenly and perpendicularly to the bearing and disc spring 21, avoiding uneven loading caused by uneven force distribution. This guarantees the uniformity and stability of the preload effect, resulting in smoother floating motion and more durable mechanism performance.

[0033] refer to Figures 1-4 The connecting plate 4 has a mounting hole, and the contact displacement sensor 5 is installed in the mounting hole. The connecting plate 4 has a threaded hole 41 communicating with the mounting hole. A locking screw 42, which can extend into the mounting hole, is threaded into the threaded hole 41. A copper sleeve 43 is provided between the contact displacement sensor 5 and the mounting hole. The copper sleeve 43 can be fitted or locked onto the outer wall of the contact displacement sensor 5. The locking screw 42 secures the contact sensor in the mounting hole of the connecting plate 4 by tightening the copper sleeve 43. The contact displacement sensor 5 is installed in the mounting hole through a copper sleeve 43. The copper sleeve 43, as a vulnerable and replaceable transition fitting, has a tight fit between its outer wall and the mounting hole, and a sliding fit between its inner hole and the outer wall of the sensor. The copper sleeve 43 achieves non-destructive, high-rigidity clamping of the contact displacement sensor, avoiding potential pressure marks caused by the locking screw directly pressing against the sensor housing. After the contact displacement sensor 5 is adjusted to the appropriate position, the locking screw 42 is tightened, and its end directly presses against the outer wall of the copper sleeve 43. The copper sleeve 43 undergoes a slight elastic deformation under the action of radial force, thereby gripping the contact displacement sensor 5 and achieving a firm fixation without slippage.

[0034] refer to Figures 1-4 The measuring mechanism also includes a driving device (not shown in the figure). The driving device can be a cylinder. The driving device is connected to the fixed base plate 1 and is used to drive the probe 8 to move along its axial direction, thereby inserting it into the hole to be measured and detecting the hole, thereby further improving the degree of automation, shortening the measurement cycle, and improving the detection efficiency.

[0035] Working process: At the start of measurement, the drive device is activated, and its piston rod extends, pushing the floating plate 3, connecting rod 31, connecting plate 4, contact displacement sensor 5, and probe 8 along the axial direction of the fixed shaft seat 2 towards the hole to be measured on the workpiece. When the probe 8 approaches the hole opening, if there is a slight positional deviation between the central axis of the hole being measured and the initial central axis of the probe 8, the edge of the hole opening will contact the tip of the probe 8, applying a radial force to the probe 8. This radial force is transmitted to the floating plate 3 through the connecting plate 4 and connecting rod 31.

[0036] Since the floating plate 3 is mounted on the fixed bearing 2 via the first plane bearing 61 and the second plane bearing 62, and the disc spring 21 and the locking nut 22 provide an elastic preload that can eliminate axial clearance and ensure flexible floating, under the action of radial force, the floating plate 3, the connecting rod 31, the connecting plate 4, the contact displacement sensor 5 and the probe 8 are forced to produce adaptive translational floating in the horizontal plane, thereby driving the probe 8 to finely adjust its position until its axis is aligned with the axis of the hole, so that the probe 8 can be smoothly and without interference completely inserted into the hole to be measured, completing the key automatic centering process.

[0037] After the probe 8 enters the hole, its internal mechanical structure, such as evenly distributed steel balls and wedges, contacts the hole wall, converting the radial displacement reflecting the hole diameter into axial displacement through a lever principle. The probe can be an M1 STAR™ type or other existing probes. This axial displacement is transmitted to the detection end of the contact displacement sensor 5 via the transmission mechanism inside the probe 8. The contact displacement sensor 5 accurately captures this axial displacement and converts it into an electrical signal output. The system processes this signal to obtain the actual diameter of the measured hole.

[0038] After the measurement is completed, the piston rod of the drive device retracts, and the probe 8 exits the measured hole axially. Under the uniform action of the restoring force of the disc spring 21 and the low friction characteristics of the plane bearing, it can stably return to the initial center position, preparing for the next high-precision measurement cycle.

[0039] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A micro aperture measuring mechanism, characterized in that, include: A fixed bearing (2) and a floating plate (3) are provided. The fixed bearing (2) is fixedly connected to the fixed base plate (1) by a support rod (23). A plane bearing is sleeved on the fixed bearing (2). The floating plate (3) is sleeved on the fixed bearing (2) by the plane bearing. A floating gap is left between the outer diameter of the fixed bearing (2) and the inner hole of the floating plate (3), so that the floating plate (3) floats in the horizontal plane relative to the fixed bearing (2). The floating plate (3) is connected to a connecting rod (31), the connecting rod (31) is connected to a connecting plate (4), a contact displacement sensor (5) is installed on the connecting plate (4), the probe (8) is connected to the detection end of the contact displacement sensor (5) in a transmission connection, the floating plate (3) floats in the horizontal plane when the probe (8) is subjected to radial force, so as to automatically compensate for the positional deviation between the measured hole and the probe (8).

2. The micro aperture measuring mechanism according to claim 1, characterized in that: The fixed shaft seat (2) is provided with a disc spring (21) and a locking nut (22). The disc spring (21) is located between the plane bearing and the locking nut (22). The disc spring (21) is locked by the locking nut (22). Under the pressure of the locking nut (22), the disc spring (21) provides axial elastic preload to the floating plate (3) and the plane bearing.

3. The micro aperture measuring mechanism according to claim 2, characterized in that: The planar bearing includes a first planar bearing (61) and a second planar bearing (62). The first planar bearing (61) and the second planar bearing (62) are respectively arranged on both sides of the floating plate (3). The first planar bearing (61) is arranged between the floating plate (3) and the base of the fixed bearing seat (2). The second planar bearing (62) is arranged between the disc spring (21) and the floating plate (3).

4. The micro aperture measuring mechanism according to claim 3, characterized in that: A first washer (71) is arranged on one side of the disc spring (21), and the first washer (71) is arranged between the second planar bearing (62) and the disc spring (21).

5. The micro aperture measuring mechanism according to claim 4, characterized in that: A second washer (72) is arranged on the other side of the disc spring (21), and the second washer (72) is arranged between the locking nut (22) and the disc spring (21).

6. A micro aperture measuring mechanism according to any one of claims 1-5, characterized in that: The connecting plate (4) has a mounting hole, the contact displacement sensor (5) is installed in the mounting hole, the connecting plate (4) has a threaded hole (41) communicating with the mounting hole, the threaded hole (41) is provided with a locking screw (42) extending into the mounting hole, a copper sleeve (43) is provided between the contact displacement sensor (5) and the mounting hole, and the locking screw (42) fixes the contact sensor in the mounting hole of the connecting plate (4) by tightening the copper sleeve (43).

7. A micro aperture measuring mechanism according to claim 6, characterized in that: It also includes a drive device, which, together with the fixed base plate (1), is used to drive the probe (8) to move along its axial direction.

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