An asymmetric three-point internal diameter measuring gauge and method

Abstract

The application discloses a kind of asymmetric three-point inner diameter measuring gauge and method, belong to measuring tool technical field;Including general inner diameter dial gauge, as measuring main body;It further includes auxiliary measurement module, the auxiliary measurement module is connected with the fixed measuring head of general inner diameter dial gauge by lengthening connecting rod, including two self-adapting telescopic measuring rod legs, its root is installed in the tail end of lengthening connecting rod, head and measurement surface contact;And the included angle between two measuring rod legs can be adaptively adjusted, and asymmetric point measurement can be realized.The application takes general inner diameter gauge as measuring main body, can ensure measurement accuracy;Increase auxiliary measurement module on the basis of measuring main body, i.e. two self-adapting telescopic measuring rod legs, and the angle between two measuring rods is adjustable and locked.The gauge can measure the diameter of the side window, opening or odd measurement points with uniform but asymmetric diameter after calibrating the diameter size required for measurement with special calibration ring.

Description

Technical Field

[0001] This invention belongs to the field of measuring tool technology, specifically relating to an asymmetric three-point inner diameter measuring instrument and method. Background Technology

[0002] An internal diameter measuring instrument is a tool for measuring the diameter of an internal hole. Various measurement methods are disclosed in the prior art, listed below:

[0003] 1. Existing general-purpose two-point measuring tools, such as vernier calipers, inside micrometers, and internal micrometers (two-jaw gauges), are used for symmetrical point measurements. They can only measure even-numbered ribs, symmetrical planes, symmetrical edges, and complete inner and outer diameters. They cannot measure side cutouts, openings, or asymmetrical measurement points.

[0004] 2. The general-purpose internal measuring (three-jaw) micrometer can be used to measure the inner diameter of uniformly distributed measuring points that are divisible by three. However, it cannot measure the inner diameter of uniformly distributed measuring points that are not divisible by three, such as (5, 7, 11).

[0005] 3. Fixed measuring tools such as dedicated plug gauges and composite gauges can only determine whether the finished dimensions are within the acceptable tolerance range. They cannot measure specific values ​​during machining and cannot provide a basis for subsequent machining. For parts with large inner diameters, the plug gauges produced are bulky, difficult for a single person to operate, and require a high level of skill from the operator.

[0006] Existing general-purpose two-point or three-point measuring tools can only measure even-numbered measuring points, symmetrical planes, symmetrical edges, and complete inner and outer diameters. They cannot measure side cutouts, openings, or asymmetrical measuring points. Custom-made plug gauges and composite gauges, which are fixed-dimensional measuring tools, can only determine the acceptable range of the measured surface after machining; they cannot measure specific values ​​and cannot provide dimensional basis for subsequent cuts during the machining process. Summary of the Invention

[0007] The technical problem to be solved:

[0008] To overcome the shortcomings of existing technologies, this invention provides an asymmetric three-point inner diameter measuring instrument and method. Using a general-purpose inner diameter gauge as the main measuring body, it ensures measurement accuracy. An auxiliary measuring module is added to the main measuring body, consisting of two adaptive telescopic measuring rod legs, with an adjustable and lockable angle between the two rods. After calibrating the required diameter size using a dedicated calibration ring, this instrument can measure the diameter of side cutouts, openings, or evenly distributed but asymmetrical odd-numbered measuring points (e.g., 5, 7, or 11 ribs evenly distributed).

[0009] The technical solution of the present invention is: an asymmetric three-point internal diameter measuring instrument, including a general internal diameter dial indicator as the measuring body; and an auxiliary measuring module, wherein the auxiliary measuring module is connected to the fixed probe of the general internal diameter dial indicator through an extended connecting rod;

[0010] The auxiliary measurement module includes two adaptive telescopic measuring rod legs, the roots of which are installed at the tail end of the extended connecting rod, and the heads of which are in contact with the measuring surface; and the included angle between the two measuring rod legs can be adaptively adjusted to achieve asymmetric point measurement.

[0011] A further technical solution of the present invention is as follows: the measuring rod support leg includes a support leg, a pressure spring, a telescopic measuring rod, and a contact; a blind hole is opened at one end of the support leg along the central axis, and the pressure spring and the telescopic measuring rod are coaxially installed in sequence in the blind hole; the contact is coaxially installed at the outer end of the telescopic measuring rod; the telescopic measuring rod and the contact can adaptively extend and retract along the axial direction under the force of the pressure spring; the contact contacts the measuring surface and locks it in place after determining the axial position; the outer circumferential surface of the telescopic measuring rod is provided with a scale for measurement during coarse length adjustment;

[0012] The other end of each of the two support legs is connected to the tail end of the extended connecting rod, which can adjust the included angle between the two measuring rod support legs according to the measurement needs, and lock and fix it after the included angle is determined.

[0013] A further technical solution of the present invention is as follows: the other end of each of the two support legs is a lug structure with a through hole, which is connected to the tail end of the extended connecting rod through a base; the base is a U-shaped structure, and the fastening screw passes through the through hole on the bottom surface and is threadedly connected to the tail end of the extended connecting rod; a light hole is opened on one side wall of the base, and a threaded hole is opened on the other side wall; the two lugs are inserted between the two side walls, and the through hole, light hole and threaded hole on the lugs are coaxial, and are tightened and fixed by a multi-functional locking shaft installed coaxially.

[0014] A further technical solution of the present invention is: the head of the multifunctional locking shaft is a clamping part, the middle part is a smooth shaft, and the tail is threaded. It coaxially passes through the smooth hole of the base and the through holes of the two lugs in sequence, and is screwed into the threaded hole of the base. After determining the angle, it is tightened to realize the locking and fixing of the two measuring rod legs.

[0015] A further technical solution of the present invention is as follows: a cylindrical protrusion is provided on the outer end face of the bottom surface of the base, and a through hole in the bottom surface penetrates the cylindrical protrusion; a threaded blind hole is opened along the axial direction at the tail end of the extended connecting rod, the upper smooth hole portion of the threaded blind hole is fitted with the cylindrical protrusion of the base, and the bottom end is a threaded hole portion; a fastening screw passes through the through hole of the bottom surface of the base and the cylindrical protrusion, and is screwed into the bottom end of the threaded blind hole to fix the base and the tail end of the extended connecting rod; the connection strength of the fastening screw is enhanced by the cylindrical protrusion provided on the bottom surface.

[0016] A further technical solution of the present invention is: one end of the support leg has a radial threaded hole, and the fastening screw is screwed into the threaded hole radially to apply radial pressure to the telescopic measuring rod, thereby fixing the axial position of the telescopic measuring rod.

[0017] A further technical solution of the present invention is: the auxiliary measurement module further includes an arc-shaped angle indicator, which is an arc-shaped flat plate structure with angle markings engraved on its surface. An arc-shaped through groove is opened between its inner and outer arc surfaces. Two fastening screws are respectively installed on the two reduced measuring rod legs through the arc-shaped through groove. The angle between the two reduced measuring rod legs is adjusted by the sliding of the two fastening screws in the arc-shaped through groove. After the angle is determined, the arc-shaped angle indicator is fixed and the angle is locked by tightening the two fastening screws.

[0018] A further technical solution of the present invention is that the axial direction of the universal inner diameter dial indicator is perpendicular to the plane containing the central axis of the two adaptive telescopic measuring rod legs.

[0019] A further technical solution of the present invention is: the contact end between the contact and the measuring surface is a spherical structure; multiple pairs of spherical contacts of different lengths are provided according to the measurement needs.

[0020] A measurement method for an asymmetric three-point inner diameter measuring instrument, characterized by the following specific steps:

[0021] Step 1: Assemble the measuring tools;

[0022] Select an extended connecting rod of appropriate length according to the drawing requirements of the part to be measured. Install a universal internal diameter dial indicator at one end and a base at the other end. The two measuring rod legs are hinged to the base through a multi-functional locking shaft. After adjusting the included angle to match the angle of the measured point, lock and fix the arc-shaped angle indicator and the multi-functional locking shaft.

[0023] Step 2: Calibrate the measuring tools;

[0024] After the measuring tool is assembled, it is placed in the calibration ring; the measuring rod legs extend and retract adaptively under the action of the internal pressure spring. After the contact is pressed against the inner wall of the calibration ring, the radially set fastening screws are tightened to fix the axial position of the telescopic measuring rod, and the dial indicator scale is adjusted to the "0" position.

[0025] Step 3: Measuring with measuring tools;

[0026] After the measuring tool is calibrated, it is placed inside the part being machined or has been machined to measure the inner diameter. The measuring tool can measure the inner diameter of side cutouts, openings, or evenly distributed but asymmetrical odd-numbered measuring points, and the reading difference can be directly used as the basis for subsequent machining.

[0027] Beneficial effects

[0028] The beneficial effects of this invention are as follows: The asymmetric three-point inner diameter measuring instrument of this invention has an auxiliary measuring module installed on the measuring body. The auxiliary measuring module measures asymmetric measuring points by adjusting the included angle between the legs of the two adaptive telescopic measuring rods. The adaptive telescopic measuring rod is connected to the telescopic measuring rod through a built-in pressure spring. A spherical contact probe is installed at the end of the telescopic measuring rod. Under the force of the pressure spring, the contact probe is pressed tightly against the measuring wall surface. After calibrating the required diameter size through a special calibration ring, the diameter of side cutouts, openings, or evenly distributed but asymmetrical odd-numbered measuring points (such as 5, 7, or 11 evenly distributed ribs) can be measured.

[0029] After measuring the inner diameter of evenly distributed but asymmetrical measuring points (such as 5, 7, and 11 ribs) using the measuring tool of this invention, the readings can be directly used as the basis for subsequent machining cuts, providing a reliable measurement method for machining such parts and improving the pass rate of these parts. At the same time, it reduces the skill requirements for operators, shortens the machining cycle of components, and improves production efficiency.

[0030] In production practice, this measuring tool and method have been applied to the machining of side-cut windows, open shells, and end caps produced in the branch factory. This has reduced the difficulty of inspection and improved processing efficiency. It also avoids the production costs associated with customizing dedicated plug gauges and coordinate measuring machine (CMM) equipment for prototype machining. Attached Figure Description

[0031] Figure 1 This is an exploded view of the parts of an asymmetric three-point inner diameter measuring tool according to the present invention.

[0032] Figure 2 This is an exploded isometric view of a part of an asymmetric three-point inner diameter measuring tool according to the present invention.

[0033] Figure 3 This is an isometric view of the assembly of parts for an asymmetric three-point inner diameter measuring tool according to the present invention;

[0034] Figure 4 This is a schematic diagram illustrating the application scenario of an asymmetric three-point inner diameter measuring tool according to the present invention;

[0035] Explanation of reference numerals in the attached drawings: 1. Extended connecting rod; 2. Base; 3. Multifunctional locking shaft; 4. Arc-shaped angle indicator; 5. Telescopic measuring rod; 6. Measuring rod support leg; 7. Spherical contact; 8. Fastening screw; 9. Calibration ring; 10. Universal inside dial indicator; 11. Pressure spring. Detailed Implementation

[0036] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0037] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0038] In the processing of side-cut window end cap parts produced in the branch factory, the asymmetric three-point inner diameter measuring tool described in this invention is used for measurement, avoiding the production cost of customizing special plug gauges and coordinate measuring machines in the processing of prototypes.

[0039] Reference Figure 1-4 As shown, the present invention provides an asymmetric three-point inner diameter measurement method comprising a universal inner diameter dial indicator 10, an extended connecting rod 1, and an auxiliary measurement module. The universal inner diameter dial indicator serves as the main measuring component. The auxiliary measurement module is connected to the fixed probe of the universal inner diameter dial indicator via the extended connecting rod. The auxiliary measurement module includes two adaptive telescopic measuring rod legs 6, the roots of which are mounted at the tail end of the extended connecting rod 1, with their heads contacting the measuring surface. The included angle between the two measuring rod legs 6 can be adaptively adjusted to achieve asymmetric point measurement.

[0040] The extended connecting rod 1 is a hollow cylindrical stepped rod structure. Depending on the diameter of the part being measured, a connecting rod group of appropriate length can be selected for use. The outer circumference of the stepped section at the large end of the extended connecting rod 1 has a keyway for directional fastening to the flat key in the universal internal dial indicator 10. It is fixedly connected to the base 2 at the small end face by fastening screws 8. The keyway on the small end face, with its directional function, ensures that the two measuring rod legs 6 are horizontally stable on the same horizontal plane, guaranteeing measurement accuracy.

[0041] The measuring rod support leg 6 includes a support leg, a pressure spring 11, a telescopic measuring rod 5, and a spherical contact 7. One end of the support leg has a blind hole along its central axis. The pressure spring 11 and the telescopic measuring rod 5 are coaxially installed in the blind hole. The spherical contact 7 is coaxially installed on the outer end of the telescopic measuring rod 5. Under the force of the pressure spring 11, the telescopic measuring rod 5 and the spherical contact 7 can adaptively extend and retract along the axial direction. After the spherical contact 7 contacts the measuring surface and determines its axial position, it is locked and fixed. The outer circumferential surface of the telescopic measuring rod 5 is provided with a scale for measurement during coarse length adjustment. The other end of both support legs has a lug structure with a through hole, which is connected to the tail end of the extended connecting rod 1 through the base 2. One end of the support leg has a radial threaded hole. The fastening screw is screwed into the threaded hole radially to apply radial pressure to the telescopic measuring rod, thereby fixing the axial position of the telescopic measuring rod.

[0042] The base 2 has a U-shaped structure. A fastening screw passes through a through-hole on the bottom surface and is threaded to the end of the extended connecting rod 1. One side wall of the base 2 has a smooth hole, and the other side wall has a threaded hole. Two lugs are inserted between the two side walls, with the through-hole, smooth hole, and threaded hole on the lugs coaxial. A multi-functional locking shaft 3, installed coaxially, is tightened and fixed. The multi-functional locking shaft 3 has a clamping head, a smooth shaft in the middle, and an external thread at the tail. It passes coaxially through the smooth hole and the through-holes of the two lugs in sequence, and is screwed into the threaded hole of the base. After determining the angle, it is tightened to lock and fix the two measuring rod legs. The multi-functional locking shaft 3 is machined to the appropriate dimensions through grinding and quenching processes. A slotted structure is provided on the end face of its clamping part for manual locking. The base 2 has a cylindrical protrusion on its outer bottom surface, and a through hole in the bottom surface passes through the cylindrical protrusion. The tail end of the extended connecting rod 1 has a threaded blind hole along the axial direction. The upper smooth hole in the threaded blind hole mates with the cylindrical protrusion of the base, and the bottom end is a threaded hole. The fastening screw passes through the through hole in the bottom surface of the base and the cylindrical protrusion, and is screwed into the bottom end of the threaded blind hole to fix the base and the tail end of the extended connecting rod. The cylindrical protrusion on the bottom surface enhances the connection strength of the fastening screw.

[0043] The auxiliary measurement module also includes an arc-shaped angle indicator 4, which is a flat arc-shaped structure with angle markings engraved on its surface. An arc-shaped through groove is opened between its inner and outer arc surfaces. Two fastening screws pass through the arc-shaped through groove and are installed on the two reduced measuring rod legs. The sliding of the two fastening screws in the arc-shaped through groove drives the adjustment of the included angle between the two reduced measuring rod legs. After the included angle is determined, the arc-shaped angle indicator 4 is fixed and the included angle is locked by tightening the two fastening screws, thus completing the coarse angle adjustment.

[0044] The spherical contact 7 has paired contacts of different lengths. The fastening screw 8 is a standard hexagonal head screw used to fasten the extended connecting rod and base. Alternatively, the fastening screw 8 has a Torx head and is manually tightened for locking the arc-shaped angle indicator 4 and the telescopic measuring rod 5. The calibration ring 9 is machined according to the basic inner hole dimensions required by the drawings, and the actual values ​​obtained through metrological testing are used for subsequent dimensional calibration.

[0045] The product housing and end caps measured in this embodiment both have 11 ribs and windows. During machining, the inner diameter of these areas cannot be directly measured, hindering subsequent tooling and easily leading to out-of-tolerance or scrapped parts. The accompanying comprehensive gauge can only determine the current condition of the part after machining, without providing specific adjustment values. Using this measurement method, the readings can be directly used as the basis for subsequent machining, successfully solving the problem and significantly improving the pass rate of this model's housing and end cap parts. This measuring tool and method provide a reliable measurement method for the preliminary research of similar products with odd-numbered or asymmetrical measuring points. It also reduces the skill requirements for operators, shortens the processing cycle of components, and improves production efficiency.

[0046] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. An asymmetric three-point internal diameter measuring gauge comprising a universal internal diameter dial gauge as a measuring body; characterized in that: The auxiliary measurement module is connected with the fixed measuring head of the universal inside diameter dial gauge through an extended connecting rod; The auxiliary measurement module comprises two self-adapting telescopic measuring rod legs, the roots of which are installed at the tail end of the extended connecting rod, and the heads of which are in contact with the measuring surface; and the included angle between the two measuring rod legs can be adaptively adjusted to realize the measurement of asymmetric points. The measuring rod leg comprises a leg, a pressure spring, a telescopic measuring rod and a contact head; a blind hole is formed in one end of the leg along the central axis, and the pressure spring and the telescopic measuring rod are coaxially installed in the blind hole in sequence; the contact head is coaxially installed at the outer end of the telescopic measuring rod; the telescopic measuring rod and the contact head can be self-adaptively telescopic along the axial direction under the action of the pressure spring; the contact head is locked and fixed after being in contact with the measuring surface and determining the axial position; a scale is arranged on the outer circumferential surface of the telescopic measuring rod for measuring the length during coarse adjustment; the other end of the two legs is connected with the tail end of the extended connecting rod, and the included angle between the two measuring rod legs can be adjusted according to the measurement requirement, and the included angle is locked and fixed after being determined. The other end of the two legs is a lug structure with a through hole, which is connected with the tail end of the extended connecting rod through a base; the base is a U-shaped structure, a fastening screw is screwed into the tail end of the extended connecting rod through the through hole in the bottom surface and is threadedly connected with the tail end of the extended connecting rod; a light hole is formed in one side wall surface of the base, a threaded hole is formed in the other side wall surface, the two lugs are inserted between the two side wall surfaces, and the through hole in the lug is coaxial with the light hole and the threaded hole, and the multifunctional locking shaft is coaxially installed and is tightened to be fixed. The auxiliary measurement module further comprises an arc-shaped angle indicating scale, which is a circular arc type flat plate structure with angle scale lines marked on the surface, and a circular arc type through slot is formed between the inner and outer arc surfaces; two fastening screws are installed on the two telescopic measuring rod legs through the circular arc type through slot respectively, and the adjustment of the included angle between the two telescopic measuring rod legs is driven by the sliding of the two fastening screws in the circular arc type through slot; after the included angle is determined, the two fastening screws are tightened to realize the fixation of the arc-shaped angle indicating scale and the locking of the included angle.

2. The asymmetric three-point inner diameter measuring gauge of claim 1, wherein: The head of the multifunctional locking shaft is a clamping part, the middle part is a light rod shaft, and the tail end is provided with external threads; the multifunctional locking shaft is coaxially passed through the light hole of the base, the through holes of the two lugs in sequence, and is screwed into the threaded hole of the base; after the angle is determined, the multifunctional locking shaft is tightened to realize the locking and fixation of the two measuring rod legs.

3. The asymmetric three-point inner diameter measuring gauge of claim 1, wherein: A cylindrical protrusion is arranged on the outer end surface of the bottom surface of the base, and the through hole in the bottom surface penetrates the cylindrical protrusion; a threaded blind hole is formed in the tail end of the extended connecting rod along the axial direction, the upper end light hole part of the threaded blind hole is matched and installed with the cylindrical protrusion of the base, and the bottom end is a threaded hole part; a fastening screw is passed through the through hole of the cylindrical protrusion and the bottom surface of the base, and is screwed into the bottom end of the threaded blind hole to fixedly connect the base with the tail end of the extended connecting rod; the connection strength of the fastening screw is enhanced by the cylindrical protrusion arranged on the bottom surface.

4. The asymmetric three-point inner diameter measuring gauge of claim 1, wherein: A radial threaded hole is formed in one end of the leg, and a fastening screw is screwed into the threaded hole along the radial direction to apply radial pressure to the telescopic measuring rod, so as to fix the axial position of the telescopic measuring rod.

5. The asymmetric three-point inner diameter measuring gauge of claim 1, wherein: The axial direction of the universal inside diameter dial gauge is perpendicular to the plane in which the central axes of the two self-adapting telescopic measuring rod legs are located.

6. The asymmetric three-point inner diameter measuring gauge of claim 1, wherein: The contact end of the contact with the measuring surface is a spherical structure; a plurality of pairs of spherical contacts with different lengths are provided according to the measuring requirement.

7. A method of measuring with a non-symmetrical three-point inside diameter measuring gauge according to claim 5 or 6, characterized in that The specific steps are as follows: Step 1: assemble the gauge; According to the drawing requirement of the measured part, select the appropriate length of the extended connecting rod, install the universal inside diameter dial indicator at one end and the base at the other end; the two measuring rod legs are hinged to the base through the multifunctional locking shaft, and the included angle is adjusted to conform to the measured point angle, then the arc angle indicating scale and the multifunctional locking shaft are locked and fixed; Step 2: check the gauge; After the gauge is assembled, it is placed in the checking ring; the measuring rod legs are self-adaptingly stretched and contracted under the action of the internal pressure spring, the contact is tightly attached to the inner wall of the checking ring, then the axial position of the telescopic measuring rod is fixed by tightening the radially arranged fastening screw, and the dial indicator scale is adjusted to "0" position; Step 3: gauge measurement; After the gauge is checked, it is placed in the measured part being processed or processed to measure the inside diameter; the gauge can measure the inside diameter of the odd measuring points on the side window, opening or uniform but asymmetric part, and the reading difference can be directly used as the basis for subsequent processing feed.

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