Hole-based out-of-plane feature measurement apparatus and method

Abstract

The application discloses a kind of hole-based out-of-plane feature measuring device and measuring method, belong to mechanical parts geometric quantity measurement technical field.To solve the problems of unstable reference positioning of existing measuring tool, inflexible out-of-plane adjustment, low precision and poor universality, the device includes adjustable reference positioning assembly, support assembly, sliding rotation assembly and sliding measurement assembly;Adjustable reference positioning assembly adopts three-jaw self-centering structure to insert reference hole and automatically center;Support assembly is provided with first linear guide groove;Sliding rotation assembly can slide and rotate;Sliding measurement assembly is used to measure out-of-plane feature.The application also discloses a corresponding measuring method.The application is convenient to operate, accurate in positioning, strong in universality, and can realize fast and accurate measurement.

Description

Technical Field

[0001] This invention relates to the field of geometric measurement technology for mechanical parts, specifically to a measuring device and method that uses the reference hole of the part under test as a positioning reference to measure the position, distance and other parameters of non-coplanar features, and is suitable for small-batch production inspection of mechanical parts such as boxes, brackets and shells. Background Technology

[0002] In the field of mechanical manufacturing, many parts (such as engine blocks, gearbox housings, machine tool supports, etc.) have non-coplanar features, such as holes, planes, grooves, steps, etc., that are at a certain angle to a reference plane. During machining and assembly, it is often necessary to use a reference hole as a reference to measure the relative positional accuracy of these non-coplanar features to ensure the assembly quality and performance of the product.

[0003] Currently, existing technologies mainly employ the following methods to address this type of measurement need: 1. Coordinate Measuring Machine Coordinate measuring machines (CMMs) are currently widely used precision measuring devices, offering high accuracy and comprehensive functions. However, CMMs also suffer from drawbacks such as high cost, complex operation, the need for specialized personnel, and low measurement efficiency, making them unsuitable for the batch inspection needs of production lines. Especially in small-batch, multi-variety production models, frequent clamping, programming, and measurement significantly increase inspection costs and time.

[0004] 2. Specialized inspection tools Specialized gauges designed for specific parts have the advantages of high measurement efficiency and ease of operation. However, these gauges have poor versatility. When the part model or specifications change, new gauges need to be redesigned and manufactured, resulting in long production cycles and high costs, making it difficult to adapt to the needs of rapid product iteration.

[0005] 3. General measuring tools When using common measuring tools such as calipers, micrometers, and dial indicators, the lack of a structure for precise positioning with a reference hole makes it difficult to ensure consistency between the measurement reference and the design reference. Especially when measuring across surfaces, the direction and position of the measuring force are difficult to control, resulting in large measurement errors. Furthermore, the measurements are easily affected by human factors, leading to poor repeatability and reproducibility of the measurement results.

[0006] 4. Visual Measurement Methods In recent years, visual measurement technology (such as Chinese patent CN104897062A) has been applied to the measurement of non-linear features. This type of method uses a binocular camera to acquire images of the part, extracts features through image processing, and reconstructs 3D information. However, visual measurement systems are costly, sensitive to ambient lighting, and difficult to achieve positioning measurements using a reference hole as a physical reference, thus limiting their application on production lines.

[0007] 5. Measuring fixtures for non-planar features of shaft parts For non-circular features such as oblique holes on shaft-type parts, some specialized mechanical inspection tools exist in the prior art (such as patent CN 110220436 A, a tool for measuring the positional accuracy of oblique holes on the outer wall of a shaft). These tools use a sliding mechanism in conjunction with a dial indicator for measurement, but their positioning datum is usually the outer circle or end face of the shaft-type part, making them unsuitable for measurement scenarios where a reference hole is used as the positioning datum (such as for box-type or shell-type parts). Furthermore, these tools are typically only applicable to a single type of non-circular feature, limiting their versatility.

[0008] In summary, the existing technology has the following technical problems: inaccurate benchmark positioning or unsuitability for hole benchmark scenarios, inflexible adjustment between different surfaces, low measurement accuracy, poor versatility, high cost or complicated operation, resulting in high production and testing costs and difficulty in guaranteeing product qualification rate. Summary of the Invention

[0009] (a) Technical problems to be solved The present invention aims to overcome the shortcomings of the prior art and provide a device and method for measuring non-planar features based on a hole. It solves the technical problems of unstable reference positioning, inflexible non-planar adjustment, low measurement accuracy, and poor versatility of existing measuring tools when measuring non-planar features with reference holes. It enables rapid and accurate measurement of reference holes of different specifications and non-planar features at different angles.

[0010] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: A non-planar feature measuring device based on a hole, comprising: An adjustable reference positioning component is used to insert into the reference hole of the part being measured and automatically center it; A support component, the first end of which is fixedly connected to the adjustable reference positioning component, and the support component is provided with a first linear guide groove along its length direction; A sliding rotation assembly includes a sliding rotation block and a pin. The sliding rotation block is slidably engaged with a first linear guide groove of the support assembly via the pin, and the sliding rotation block is rotatable relative to the support assembly about the pin. A sliding measurement component, which slides in conjunction with the sliding rotation component, is used to measure the non-planar features of the part being measured.

[0011] Furthermore, the adjustable reference positioning component includes a disk body, a plurality of claws evenly distributed on the disk body in the circumferential direction, and a drive mechanism for driving the plurality of claws to move radially in sync. Each of the plurality of claws is provided with a positioning part for abutting against the inner wall of the reference hole.

[0012] Furthermore, the drive mechanism of the adjustable reference positioning component includes a chuck screw and a bevel gear. The bevel gear is connected to the chuck screw, and the chuck screw cooperates with the plurality of jaws. When the bevel gear is rotated, the chuck screw drives the plurality of jaws to move radially in sync.

[0013] Furthermore, the plurality of jaws consists of three jaws, which are evenly distributed at 120° intervals along the circumference of the disc.

[0014] Furthermore, the sliding rotation assembly is provided with a second linear guide groove along its length direction, and the sliding measurement assembly slides in conjunction with the second linear guide groove via a round-headed flat key.

[0015] Furthermore, the sliding measurement assembly includes a ruler body, a secondary ruler, a boundary measuring block, and a limiting screw. The secondary ruler is slidably disposed on the ruler body, which has a main scale and a vernier scale. The boundary measuring block is fixed to the end of the secondary ruler for alignment with the non-planar features of the part being measured. The limiting screw is used to lock the relative position of the secondary ruler and the ruler body.

[0016] Furthermore, the adjustable reference positioning component has a positioning aperture adjustment range of φ6mm-φ20mm and a positioning accuracy of 0.01mm-0.03mm; the main scale has an accuracy of 0.1mm and the secondary scale has an accuracy of 0.02mm.

[0017] The present invention also provides a method for measuring non-planar features based on a hole using the above-described device, comprising the following steps: Step 1, Reference Positioning: Insert the adjustable reference positioning component into the reference hole of the part to be measured, and drive multiple jaws to move radially synchronously through the drive mechanism, so that the positioning part on the jaws abuts against the inner wall of the reference hole, thereby realizing the automatic centering of the adjustable reference positioning component and the reference hole. Step 2, Attitude Adjustment: Based on the spatial position of the measured non-surface feature relative to the reference hole surface, adjust the sliding rotation component to slide along the first linear guide groove of the support component to the target position, and rotate it around the pin to the target angle; Step 3, Measurement and Adjustment: Based on the distance between the measured non-linear feature and the reference hole, adjust the sliding measurement component to slide along the second linear guide groove of the sliding rotation component to the target position, and then slide the vernier scale to align the boundary measurement block with the measured non-linear feature; Step 4: Reading and Recording: Read the readings of the main scale and the vernier scale on the sliding measurement assembly, and record the position measurement value of the measured non-surface feature relative to the reference hole.

[0018] (III) Beneficial Effects Compared with the prior art, the present invention has the following beneficial effects: 1. Precise benchmark positioning and strong versatility The adjustable reference positioning assembly adopts a three-jaw self-centering structure. Through bevel gears and chuck screws, the three jaws move radially synchronously, achieving automatic centering of reference holes with different diameters (φ6mm-φ20mm) with a positioning accuracy of 0.01mm-0.03mm. This structure ensures the consistency of the measurement reference with the design reference for each measurement and eliminates the need to replace positioning elements for different hole diameters, significantly improving versatility.

[0019] 2. Flexible and adaptable to different surfaces Through the combined design of a support component, a sliding rotation component, and a sliding measurement component, adjustment of three degrees of freedom is achieved: sliding along the first linear guide groove in the direction of the support component, rotation around the pin shaft, and sliding along the second linear guide groove in the direction of the sliding rotation component. This structure can flexibly adapt to the measurement needs of non-planar features at different angles and distances, solving the problem of inflexible non-planar adjustment in existing measuring tools.

[0020] 3. High measurement accuracy and convenient operation Employing a vernier reading mechanism with a main scale and a vernier scale working in tandem, the main scale has an accuracy of 0.1mm, and the vernier scale has an accuracy of 0.02mm, meeting the conventional accuracy requirements in the machining field. Furthermore, the measuring device is compact in structure and easy to operate, requiring no professional training to complete measurements quickly, making it suitable for batch inspection on production lines.

[0021] 4. Low cost and wide applicability Compared to coordinate measuring machines (CMMs) and vision measurement systems, this invention employs a purely mechanical structure, eliminating the need for sensors, motors, or image processing equipment, thus significantly reducing costs. Furthermore, this invention is particularly suitable for measuring the non-planar features of box-shaped and shell-like parts that use a reference hole as a positioning datum, filling a gap in existing mechanical inspection tools for this type of application.

[0022] 5. Purely mechanical structure, highly adaptable to various environments. This invention does not rely on electricity, sensors or optical components, has low sensitivity to the field environment (such as oil, dust, vibration), and has high reliability and durability. Attached Figure Description

[0023] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0024] Figure 1 This is a schematic diagram of the non-planar feature measuring device based on a hole in the embodiment. Figure 2 This is an exploded view of the adjustable reference positioning component in the embodiment; Figure 3 This is a schematic diagram of the supporting components in the embodiment; Figure 4 This is an exploded view of the sliding rotation assembly in the embodiment; Figure 5 This is an exploded view of the slip measurement component in the embodiment; Figure 6 This is a schematic diagram of the sliding measurement component in the embodiment; Figure 7 This is a schematic diagram of the working state of the non-planar feature measuring device based on the hole in the embodiment. Figure 8 This is a schematic diagram of the structure at the bevel gear in the embodiment; The reference numerals in the attached figures are explained as follows: 1-Adjustable reference positioning component; 11-Claw; 11a-Positioning part; 12-Disc body; 13-Claw screw; 14-Bevel gear; 15-Pressure cover; 16-Positioning pin; 17-Screw; 2-Support assembly; 21-First linear guide groove; 3-Sliding and rotating assembly; 31-Sliding and rotating block; 32-Pin; 33-Second linear guide groove; 4-Sliding measuring assembly; 41-Scale body; 42-Round head flat key; 43-Auxiliary scale; 44-Boundary measuring block; 45-Limit screw. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0026] Example 1 like Figures 1 to 7 As shown, this embodiment provides a non-plane feature measuring device based on a hole, including an adjustable reference positioning component 1, a support component 2, a sliding rotation component 3, and a sliding measurement component 4.

[0027] like Figure 1 , Figure 2 and Figure 8 As shown, the adjustable reference positioning assembly 1 is used to insert into the reference hole of the part being measured and automatically center it. It adopts a three-jaw self-centering structure, specifically including a disc body 12, a pressure cap 15, three jaws 11 evenly distributed circumferentially on the disc body 12, and a drive mechanism for synchronously moving the three jaws 11 radially. The three jaws 11 are evenly distributed at 120° intervals along the circumference of the disc body 12, and each jaw 11 is provided with a positioning part 11a, which is used to abut against the inner wall of the reference hole. The disc body 12 and the pressure cap 15 are connected by screws 17. The drive mechanism includes a chuck screw 13 and a bevel gear 14. The chuck screw 13 is located inside the disc body 12 and is rotatably connected to the pressure cap 15. The bevel gear 14 is rotatably connected to the side of the disc body 12. A positioning pin 16 positions the bevel gear 14 to prevent it from disengaging from the disc body 12. The bevel gear 14 is drively connected to the chuck screw 13. The chuck screw 13 engages with three jaws 11. The back of the chuck screw 13 has a flat thread that meshes with the teeth at the bottom of the jaws 11. During operation, a square-headed wrench is used to rotate the bevel gear 14. The bevel gear 14 drives the chuck screw 13 to rotate around the central axis of the pressure cap 15. The chuck screw 13 drives the three jaws 11 to move radially synchronously along the limiting groove of the disc body 12, causing the positioning part 11a on the jaws 11 to expand outwards until it tightly abuts against the inner wall of the reference hole, thus achieving automatic centering of the adjustable reference positioning component 1 and the reference hole. The adjustable reference positioning component 1 has a positioning aperture adjustment range of φ6mm-φ20mm and a positioning accuracy of 0.01mm-0.03mm, which can adapt to the reference positioning needs of various parts with different apertures.

[0028] like Figure 1 and Figure 3 As shown, the first end of the support component 2 is fixedly connected to the adjustable reference positioning component 1, and the support component 2 is provided with a first linear guide groove 21 along its length. The stroke of the first linear guide groove 21 can be configured according to the product size. In this embodiment, the stroke is 0-75mm, which is used to achieve precise adjustment of displacement.

[0029] like Figure 1 and Figure 3 The sliding rotation assembly 3 includes a sliding rotation block 31 and a pin 32. The sliding rotation block 31 is slidably engaged with the first linear guide groove 21 of the support assembly 2 via the pin 32, and the sliding rotation block 31 can rotate relative to the support assembly 2 around the pin 32. Specifically, the sliding rotation block 31 can slide along the first linear guide groove 21 within a range of 0-75mm, and can rotate around the pin 32, thereby adjusting to the corresponding position and angle according to the spatial position of the measured non-surface feature. The sliding rotation assembly 3 is also provided with a second linear guide groove 33 along its length.

[0030] like Figure 1 , Figure 5and Figure 6 As shown, the sliding measurement component 4 and the sliding rotation component 3 are slidably engaged to measure the non-planar features of the measured part. The sliding measurement component 4 includes a scale body 41, a vernier scale 43, a boundary measuring block 44, and a limiting screw 45. The scale body 41 is equipped with a main scale, and the vernier scale 43 is slidably mounted on the scale body 41. The vernier scale 43 is equipped with a vernier scale. The accuracy of the main scale is 0.1 mm, and the accuracy of the vernier scale 43 is 0.02 mm. The two together form a vernier reading mechanism. The boundary measuring block 44 is fixed to the end of the vernier scale 43 and is used to align with the non-planar features of the measured part. The limiting screw 45 is used to lock the relative position of the vernier scale 43 and the scale body 41 for easy reading and recording. The sliding measurement component 4 is slidably engaged with the second linear guide groove 33 of the sliding rotation component 3 via a round-headed flat key 42. The stroke of the second linear guide groove 33 is 0-100 mm. Sliding components of appropriate length can be configured according to the product size to achieve precise displacement adjustment.

[0031] Example 2 This embodiment provides a method for measuring non-planar features based on holes using the device described in Embodiment 1, comprising the following steps: Step 1: Baseline Positioning like Figure 7 As shown, the adjustable reference positioning component 1 is inserted into the reference hole of the part being measured. A square-headed wrench is used to rotate the bevel gear 14, which drives the chuck screw 13 to rotate. The chuck screw 13 drives the three jaws 11 to move radially in sync, causing the positioning portion 11a on the jaws 11 to expand outwards until it tightly abuts against the inner wall of the reference hole, thus achieving automatic centering of the adjustable reference positioning component 1 and the reference hole. At this time, the measuring reference of the measuring device completely coincides with the design reference (center of the reference hole) of the part being measured, and the positioning accuracy can reach 0.01mm-0.03mm.

[0032] Step 2: Posture Adjustment Based on the spatial position of the measured non-surface feature relative to the reference hole surface, firstly, adjust the sliding rotation assembly 3 to slide along the first linear guide groove 21 of the support assembly 2 to the target position, and then rotate the sliding rotation block 31 around the pin 32 to the target angle. Through the combined adjustment of sliding and rotation, the boundary measuring block 44 of the sliding measuring assembly 4 can be aligned with the approximate direction of the measured non-surface feature.

[0033] Step 3: Measurement and Adjustment Based on the distance between the measured non-uniform feature and the reference hole, adjust the sliding measuring component 4 to slide along the second linear guide groove 33 of the sliding rotating component 3 to the target position, and then slide the vernier scale 43 to precisely align the boundary measuring block 44 with the measured non-uniform feature. After the boundary measuring block 44 contacts and aligns with the measured non-uniform feature (such as the edge of a hole, a plane, a groove, etc.), tighten the limit screw 45 to lock the relative position of the vernier scale 43 and the scale body 41.

[0034] Step 4: Recording Readings Read the readings of the main scale and the vernier scale 43 on the sliding measurement assembly 4. Since the main scale and the vernier scale 43 constitute a vernier reading mechanism, the accuracy of the main scale is 0.1 mm and the accuracy of the vernier scale 43 is 0.02 mm. Through the vernier principle, the distance value of the boundary measuring block 44 relative to the center of the reference hole can be accurately read, that is, the position measurement value of the measured non-surface feature relative to the reference hole. Application Examples Application Example 1: Measuring the position of heterogeneous faces A certain engine block part has a reference hole. A slanted hole, forming a 45° angle with the reference surface, needs to be machined at a certain distance from this reference hole. When using the measuring device of this invention, firstly, the adjustable reference positioning component 1 is inserted into the reference hole, and the bevel gear 14 is rotated to automatically center it. Then, according to the design angle of the slanted hole, the sliding rotating block 31 is rotated 45° around the pin 32 and slid along the first linear guide groove 21 to its approximate position. Next, the sliding measuring component 4 is slid along the second linear guide groove 33 to align the boundary measuring block 44 with the edge of the slanted hole. Finally, the readings on the scale body 41 and the vernier scale 43 are read to obtain the precise position of the slanted hole center relative to the reference hole center. The entire measurement process can be completed within 1 minute, and the measurement accuracy meets the machining requirements.

[0035] Application Example 2: Measuring the distance between heterogeneous faces like Figure 7 As shown, a bracket part has a reference hole, and it is necessary to measure the distance of a hole on the side wall of the bracket part relative to the reference hole. When using the measuring device of this invention, firstly, the adjustable reference positioning component 1 is inserted into the reference hole and automatically centered. Then, according to the orientation of the side wall plane, the sliding rotating block 31 is rotated 90° around the pin 32 and slid along the first linear guide groove 21 to its approximate position, so that the boundary measuring block 44 of the sliding measuring component 4 faces the side wall hole. Next, the sliding measuring component 4 is slid along the second linear guide groove 33 until the boundary measuring block 44 contacts the edge of the side wall hole. Finally, the readings on the scale body 41 and the vernier scale 43 are read to obtain the distance value of the side wall hole relative to the center of the reference hole.

[0036] Beneficial effects verification To verify the beneficial effects of the present invention, the measuring device of the present invention was compared with existing technologies such as a coordinate measuring machine, a special inspection tool, and a common caliper. The test objects were 10 engine block parts from the same batch, and the measurement item was the distance from the center of the reference hole to the center of the 45° inclined hole. The test results are shown in the table below: Test results show that the present invention significantly improves measurement efficiency, reduces equipment costs and operational difficulty while maintaining measurement accuracy, and is especially suitable for on-site rapid testing needs in small-batch, multi-variety production modes.

[0037] Structural Deformation Examples The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Those skilled in the art will understand that various improvements and modifications can be made to the present invention without departing from its principles. For example: The number of grippers can be set to two, four or more, as long as synchronous radial movement and automatic centering can be achieved. The drive mechanism can adopt other forms of transmission structure, such as worm gears, racks and pinions, etc. The stroke of the first linear guide groove and the second linear guide groove can be adaptively adjusted according to the actual application scenario; The accuracy of the main scale and the vernier scale can be configured according to the measurement accuracy requirements; The boundary measurement block can be replaced with probes of different shapes, such as conical probes, planar probes, and V-shaped probes, depending on the type of feature being measured.

[0038] These improvements and modifications should also be considered within the scope of protection of this invention.

Claims

1. A device for measuring non-planar features based on a hole, characterized in that, include: An adjustable reference positioning component (1) is used to insert into the reference hole of the part being measured and automatically center it; The support component (2) has its first end fixedly connected to the adjustable reference positioning component (1), and the support component (2) has a first linear guide groove (21) along its length direction. A sliding rotation assembly (3) includes a sliding rotation block (31) and a pin (32). The sliding rotation block (31) is slidably engaged with the first linear guide groove (21) of the support assembly (2) via the pin (32), and the sliding rotation block (31) is rotatable relative to the support assembly (2) about the pin (32). The sliding measurement component (4) is slidably engaged with the sliding rotation component (3) and is used to measure the non-planar features of the part being measured.

2. The non-planar feature measuring device based on a hole according to claim 1, characterized in that, The adjustable reference positioning component (1) includes a disk body (12), a plurality of claws (11) evenly distributed on the disk body (12) in the circumferential direction, and a driving mechanism for driving the plurality of claws (11) to move synchronously in the radial direction. Each of the plurality of claws (11) is provided with a positioning part (11a) for abutting against the inner wall of the reference hole.

3. The non-planar feature measuring device based on a hole according to claim 2, characterized in that, The drive mechanism of the adjustable reference positioning component (1) includes a chuck screw (13) and a bevel gear (14). The bevel gear (14) is connected to the chuck screw (13) for transmission. The chuck screw (13) cooperates with the plurality of jaws (11). When the bevel gear (14) is rotated, the chuck screw (13) drives the plurality of jaws (11) to move radially synchronously.

4. The non-planar feature measuring device based on a hole according to claim 2, characterized in that, The multiple claws (11) are three claws, which are evenly distributed at 120° intervals along the circumference of the disc body (12).

5. The non-planar feature measuring device based on a hole according to claim 2, characterized in that, The sliding rotation component (3) is provided with a second linear guide groove (33) along its length direction, and the sliding measurement component (4) slides in cooperation with the second linear guide groove (33) through a round-headed flat key (42).

6. The non-planar feature measuring device based on a hole according to claim 5, characterized in that, The sliding measurement assembly (4) includes a ruler body (41), a secondary ruler (43), a boundary measuring block (44), and a limiting screw (45). The secondary ruler (43) is slidably disposed on the ruler body (41). The ruler body (41) is provided with a main scale, and the secondary ruler (43) is provided with a vernier scale. The boundary measuring block (44) is fixed to the end of the secondary ruler (43) and is used to align with the non-planar features of the part being measured. The limiting screw (45) is used to lock the relative position of the secondary ruler (43) and the ruler body (41).

7. The non-planar feature measuring device based on a hole according to claim 6, characterized in that, The adjustable reference positioning component (1) has a positioning aperture adjustment range of φ6mm-φ20mm and a positioning accuracy of 0.01mm-0.03mm; the main scale has an accuracy of 0.1mm and the secondary scale (43) has an accuracy of 0.02mm.

8. A method for measuring non-planar features based on a hole using the apparatus of claim 6 or 7, characterized in that, Includes the following steps: (1). Reference positioning: Insert the adjustable reference positioning component (1) into the reference hole of the part to be measured, and drive multiple jaws (11) to move radially synchronously through the drive mechanism, so that the positioning part (11a) on the jaw (11) abuts against the inner wall of the reference hole, thereby realizing the automatic centering of the adjustable reference positioning component (1) and the reference hole. (2). Attitude adjustment: Based on the spatial position of the measured non-surface feature relative to the reference hole surface, adjust the sliding rotation component (3) to slide along the first linear guide groove (21) of the support component (2) to the target position, and rotate around the pin (32) to the target angle; (3). Measurement and adjustment: Based on the distance between the measured non-surface feature and the reference hole, adjust the sliding measurement component (4) to slide along the second linear guide groove (33) of the sliding rotation component (3) to the target position, and then slide the auxiliary scale (43) to align the boundary measurement block (44) with the measured non-surface feature; (4). Reading and recording: Read the readings of the main scale and the auxiliary scale (43) on the sliding measurement component (4) and record the position measurement value of the measured non-surface feature relative to the reference hole.

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