CN211425237U

CN211425237U - Inside diameter go-no go gauge

Info

Publication number: CN211425237U
Application number: CN202020443802.0U
Authority: CN
Inventors: 翟晶晶
Original assignee: De Entropy Electromechanical Technology Shanghai Co ltd
Current assignee: De Entropy Electromechanical Technology Shanghai Co ltd
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2020-09-04
Anticipated expiration: 2030-03-31

Abstract

The utility model relates to an internal diameter leads to no-go gage, include the handle and install respectively at two gauge heads that lead to rule end and no-go gage end of handle, two gauge head shapes are similar, and every gauge head includes along vertical and divide two endocentric spherical arc work sides of putting both sides, along horizontal and divide two lateral plane of putting both sides to and along the handle axial and divide the end plane of putting two parallels at both ends, the spherical diameter of two spherical arc work sides is the same with ordinary specification diameter that leads to the no-go gage and with centre of sphere central symmetry. Compared with the prior art, the utility model discloses can be accurate, swift check out by the oval overproof of survey hole, the local overproof of internal diameter tapering, aperture are in abnormal phenomena such as tolerance critical value overproof state, the operation in-process lead to no-go gage gauge head and be surveyed frictional wear between the hole few, the operation is light, simple swift, accurate reliable, long service life.

Description

Inside diameter go-no go gauge

Technical Field

The utility model belongs to the technical field of the aperture detects, a internal diameter leads to no-go gage is related to.

Background

In the precision machining of parts, for the inspection of important aperture sizes, a check gauge special for a go-no go gauge is generally adopted for inspection, and the detection by using a universal precision measuring tool such as an internal micrometer and an internal micrometer or a CMM measuring machine has the advantages of simple operation, high efficiency, rapidness and the like, but also has the following defects or risks;

when the current common internal diameter go-no go gauge is tested, the standard of go gauge go-no go gauge is used for judging the pass, but the following two types of misjudgment risks generally exist:

1) the qualified product is judged to be unqualified and rejected, when the measured inner bore diameter is close to the lower difference of the technical requirement and within the tolerance range, the common go-no go gauge is used for checking and is easily judged to be unqualified, the wear loss is reserved during the design of the go-no go gauge plus the manufacturing tolerance of the gauge, so the size of the go-no go gauge is normally larger than the lower difference by a plurality of micrometers, when the cylindrical go gauge can be easily inserted into the measured inner bore, the measured inner bore diameter is usually required to be larger than the outer diameter of the go gauge by more than 5 micrometers, so that when the common cylindrical go gauge is used for checking the qualified workpiece with the bore diameter near the lower difference, the pass gauge is easy to be judged to be unqualified and rejected, and the cost of the part processing and manufacturing process is increased in the mis.

2) Judging the unqualified workpiece as qualified and releasing: a) when the aperture of the workpiece to be detected is totally deviated by more than a few microns (the out-of-tolerance is less than 0.01 mm), a certain gap is needed when the no-go gauge passes through the inner aperture to be detected, and the gap is related to the roughness and the cleanliness of the inner aperture to be detected and the surface of the gauge, the micro burr of the aperture and the like, so that the cylindrical no-go gauge is used for checking, the inspection is easy to be misjudged until the gauge is qualified, and the problem that the aperture with larger basic size is more prominent; b) when the inner aperture to be measured is a deep hole, the aperture of the opening part is qualified and is in the middle difference (such as D +/-0.02 mm) of the design requirement, and the aperture of the middle part or the lower part exceeds the upper deviation (such as D +/-0.04 mm), the inner aperture is judged to be qualified by mistake by using the conventional cylindrical no-go gauge, and the reference is shown in the attached figure 8; c) when the measured workpiece hole is an overall ellipse, the minor axis diameter (such as D +/-0.02 mm) is in a tolerance range, and the major axis diameter (such as D +/-0.05 mm) is over poor, the workpiece hole is checked to be qualified for misjudgment by using a conventional pass-stop gauge, and the reference is shown in the attached figure 7. The three misjudgments can cause the unqualified parts to be released incorrectly, and if the unqualified parts cannot be found in the subsequent assembly and use process, the mechanical matching function misused by the unqualified parts can fail in advance in the service process, and finally the whole mechanical product has the risk of failure.

The working surface shape of a measuring head at the end of an inner diameter go-no-go gauge is described in the recommended standard of GB/T1957-2006 technical condition of smooth limit gauge, the working surfaces of the inner diameter go-no-go gauges currently used in the market are all cylindrical surface working surfaces selected according to the standard, in the patent CN 105865291A 'one kind of inner diameter go-no-go gauge', the measuring head at the end of the go-no-go gauge is selected from incomplete cylindrical working surfaces recommended in the GB/T1957-2006 standard, and the no-go gauge is still a full cylindrical surface. The working surface of the inner diameter go-no go gauge is a cylindrical surface, in the operation and use process, the contact surface between the working surface of the go-no go gauge and the inner hole to be detected is matched by the cylindrical surface, see the attached drawings of fig. 9 and 10, before the go-no go gauge is used for detection, the cleanliness requirements on the inner hole to be detected and the working surface of the go-no go gauge are higher, the operation technique of a detection operator has certain skill requirements, the situation that a gauge measuring head is clamped in the inner hole of the workpiece to be detected and difficult to advance and retreat is easily caused, the inner hole surface of the workpiece to be detected is easily damaged, particularly when the workpiece made of softer materials is detected, the go-no go gauge and the workpiece are easily occluded and blocked, and the problems that the gauge is heavy in weight, labor-consuming in operation, easy to block, or misjudge the workpiece and the like exist in the common.

The use of the ordinary inside diameter go-no-go gauge for inspection and control has the risks of inspection misjudgment and inspection failure described in the preceding clauses, so for inspection and control of important aperture fit sizes of some key equipment or safety-related mechanical products, in order to ensure that the product quality is qualified and reduce the risk in the actual operation process, enterprises often arrange professional inspectors to use a kilo-dial gauge with higher precision or an inside micrometer or even a three-coordinate measuring instrument to perform 100% detection and confirmation, but the operation has low efficiency and high cost.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an internal diameter leads to no-go gage in order to overcome the defect that above-mentioned prior art exists. Through redesign to the gauge head shape and the working surface shape of logical no-go gage end, compare the single manipulation gimmick of ordinary logical no-go gage straight reciprocating motion, the utility model discloses an internal diameter leads to no-go gage has combined the axial position of gauge head to move and the change of circumference angular position and the operation method of swing logical no-go gage angle can inspect the diameter compliance of the arbitrary position angle of the hole of being surveyed, can be fast accurate discovery be in the critical state among the prior art nonconforming a deviation in excess defective work to avoid judging nonconforming aperture as qualified risk; qualified workpieces with the lower difference critical dimension can be accurately identified, and the waste of misjudging the qualified products into unqualified products is reduced; the requirement of ensuring that the aperture size meets the design requirement and meeting the economic requirement is met; the method can quickly and accurately detect out-of-tolerance manufacturing defects such as inner hole ellipse, inner hole taper and the like, and can partially replace the measurement of an inner diameter scale or a three-coordinate measuring instrument to detect the conformity of the hole diameter.

The purpose of the utility model can be realized through the following technical scheme:

the utility model provides an internal diameter leads to no-go gage, includes the handle and installs respectively at two gauge heads of leading to rule end and no-go gage end of handle, every gauge head includes along vertical and divide two concentric spherical arc working side of putting both sides, along horizontal and divide two side planes of putting both sides to and along the axial of handle and divide two parallel end planes of putting both ends, the diameter of the ball of two spherical arc working side is the same with the specification diameter of ordinary logical no-go gage and with the centrosymmetry of sphere.

Furthermore, the utility model discloses a gauge head shape is lamellar part spheroid.

Furthermore, the end planes of the two plates form a thickness H which is 1/30-1/2 of the nominal diameter D of the measured inner hole.

Furthermore, when the nominal diameter D is 10-20mm, the thickness H is 1/2-1/3 of the nominal diameter D;

when the nominal diameter D is 20-100mm, the thickness H is 1/3-1/10 of the nominal diameter D;

when the nominal diameter D is 100-200mm, the thickness H is 1/8-1/20 of the nominal diameter D;

the thickness H is 1/10-1/30 of the nominal diameter D when the nominal diameter D is 200-500 mm.

The factor is comprehensively considered according to the structural rigidity of the plug gauge measuring head and interference avoidance, and if the thickness is too large or too small, interference or insufficient structural rigidity can be caused in the using process.

Further, the two side planes define a width B of 1/5-4/5 of the nominal diameter D of the measured bore.

Further, when the nominal diameter D is 10-20mm, the width B is 1/2-4/5 of the nominal diameter D;

when the nominal diameter D is 20-100mm, the width B is 1/3-2/3 of the nominal diameter D;

when the nominal diameter D is 100-200mm, the width B is 1/4-2/3 of the nominal diameter D;

the width B is 1/5-1/3 of the nominal diameter D when the nominal diameter D is 200-500 mm.

This is a factor that is convenient for operation in the use process according to the functional requirements of the plug gauge head, and if the width is too large or too small, the operation is difficult or the service life and the effect are influenced.

Furthermore, two inclined planes are arranged between the working side surfaces of the two spherical arcs and the end plane tightly attached to the end part of the handle. Furthermore, the included angle between the inclined plane and the end plane close to the end part of the handle is 20-40 degrees. This is a factor of comprehensive consideration of the structural rigidity of the plug gauge head and avoidance of interference, and if the angle is too small or too large, the processing is difficult or the structural rigidity is insufficient.

Furthermore, the two spherical arc working side surfaces are respectively equal to the R angles of four circular arcs formed between the two large side planes, and the size of the four circular arcs is 1-4 mm.

Furthermore, a counter bore which is through along the axial direction of the handle is processed on the measuring head, and the measuring head is arranged on the go gauge end and the no-go gauge end of the handle through a fixing screw matched with the counter bore. The counter sink is a 90-degree counter sink, and the fixing screw is a 90-degree inner hexagonal counter sink, so that the compactness of the structure and the connection strength and reliability are guaranteed.

Furthermore, the handle is an outer hexagonal metal section, the whole outer surface of the handle is subjected to black coating treatment, an annular groove is processed at a position close to the end of the no-go gauge, and red epoxy resin paint is coated in the annular groove.

Furthermore, the depth and the width of the annular groove are respectively 2-3 mm.

Compared with the prior art, the utility model discloses to the redesign of the gauge head shape and the function of leading to the no-go gage end for gauge head overall dimension obviously reduces, and weight alleviates greatly, and the contact that leads to the gauge head working face of no-go gage end in operation process and between the measurand hole is the arc line of a set of motion, has reduced the cleanliness requirement of measurand hole surface, has reduced to lead to the no-go gage and has been surveyed the frictional wear between the work piece, and life is longer than ordinary leading to the no-go gage, and operation process is laborsaving, simple swift, accurate reliable.

Drawings

Fig. 1 is a schematic structural view of an inner diameter go-no go gauge of the present invention;

fig. 2 is a schematic front view of a probe;

FIG. 3 is a side view of the probe;

FIG. 4 is a schematic view of the operation method of the inner diameter go/no-go gauge of the present invention;

FIG. 5 is a schematic cross-sectional view of the inner diameter no-go gauge of the present invention in terms of its operation principle and operation;

fig. 6 is a schematic view of the inner diameter no-go gauge of the present invention during tilting movement;

FIG. 7 is a schematic view of an overall ellipse of an inner hole, in which a conventional inside diameter go-no-go gauge cannot detect a defect of a poor size;

FIG. 8 is a schematic diagram of a local out-of-tolerance of an internal bore inverted cone where a common internal diameter go-no-go gauge cannot detect a defect of poor size;

FIG. 9 is a schematic structural view of a conventional inside diameter go-no-go gauge;

FIG. 10 is a schematic view showing the operation of a conventional inside diameter go-no-go gauge in simple reciprocating linear movement;

the notation in the figure is:

1-handle, 2-go gauge end, 3-no-go gauge end, 4-measuring head, 5-fixing screw, 6-annular groove, 7-spherical arc working side face, 8-side plane, 9-end plane, 10-inclined plane, 11-countersunk hole, 12-measured inner hole and 13-common go-no-go gauge.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

In the following embodiments, unless otherwise specified, all the component structures that are conventional in the art to achieve the corresponding functions are shown.

The utility model provides an internal diameter leads to no-go gage, its structure is referred to as fig. 1 and is shown, including handle 1, and install respectively at handle 1 lead to rule end 2 and two gauge heads 4 of no-go gage end 3, every gauge head 4 includes along vertical and two concentric spherical arc service side 7 of branch putting both sides, along horizontal and two lateral plane 8 of branch putting both sides, and along 1 axial of handle and divide the end plane 9 of putting two parallels at both ends, the spherical diameter of two spherical arc service side 7 is the same with the ordinary specification diameter that leads to no-go gage 13 as shown 9 and with centre of sphere central symmetry.

In a specific embodiment of the present invention, please refer to fig. 2, the shape of the probe 4 of the present invention is a sheet-shaped partial sphere.

In a specific embodiment of the present invention, the thickness H formed by the two end planes 9 is 1/30-1/2 of the nominal diameter D of the measured inner hole 12, and when the nominal diameter D is 10-20mm, the thickness H is 1/2-1/3 of the nominal diameter D; when the nominal diameter D is 20-100mm, the thickness H is 1/3-1/10 of the nominal diameter D; when the nominal diameter D is 100-200mm, the thickness H is 1/8-1/20 of the nominal diameter D; the thickness H is 1/10-1/30 of the nominal diameter D when the nominal diameter D is 200-500 mm.

In a specific embodiment of the present invention, the width B formed by the two side planes 8 is 1/5-4/5 of the nominal diameter D of the measured inner hole 12.

In a more specific embodiment, the width B is 1/2-4/5 of the nominal diameter D when the nominal diameter D is 10-20 mm.

In a more specific embodiment, the width B is 1/3-2/3 of the nominal diameter D when the nominal diameter D is 20-100 mm.

In a more specific embodiment, the width B is 1/4-2/3 of the nominal diameter D when the nominal diameter D is 100-200 mm.

In a more specific embodiment, the width B is 1/5-1/3 of the nominal diameter D when the nominal diameter D is 200-500 mm.

In a specific embodiment of the present invention, please refer to fig. 2 and fig. 3 again, two inclined planes 10 are further provided between the two spherical arc working side surfaces 7 and the end plane 9 closely attached to the end of the handle 1. Furthermore, the included angle theta between the inclined surface 10 and the end plane 9 tightly attached to the end part of the handle 1 is 20-40 degrees. In a more specific embodiment, the two spherical arc working sides 7 are respectively equal to the four circular arc R angles formed by the side planes 8, and the size of the four circular arc R angles is 1-4 mm.

In a specific embodiment of the present invention, please refer to fig. 1 again, the measuring head 4 is provided with a counter bore 11 axially penetrating along the handle 1, and is mounted on the go gauge end 2 and the no-go gauge end 3 of the handle 1 through a fixing screw 5 matching with the counter bore 11.

In a specific embodiment of the present invention, please refer to fig. 1 again, the handle 1 is an outer hexagonal metal section, and an annular groove 6 is processed at a position close to the no-go gauge end 3, and red epoxy paint is coated in the annular groove 6.

In a more specific embodiment, the depth and width of the annular groove 6 are 2-3mm, respectively.

The above embodiments may be implemented individually, or in any combination of two or more.

The above embodiments are described in more detail below with reference to specific examples.

Example 1:

the embodiment provides an inner diameter go-no-go gauge, the structure of which is shown in fig. 1, and the inner diameter go-no-go gauge comprises a handle 1 and two measuring heads 4 respectively installed at a go-no-go gauge end 2 and a no-go gauge end 3 of the handle 1, the two measuring heads 4 are similar in shape, each measuring head 4 comprises two concentric spherical arc working side surfaces 7 which are longitudinally and separately arranged at two sides, two side planes 8 which are transversely and separately arranged at two sides, and two parallel end planes 9 which are axially and separately arranged at two ends of the handle 1, and the spherical diameters of the two spherical arc working side surfaces 7 are the same as the specification diameter of a common go-no-go gauge 13 and are symmetrical about the center of a sphere.

Referring again to fig. 2 and 3, the probe 4 is shaped as a partial sphere in the form of a thin sheet. The width B formed by the two side planes 8 is 1/5-4/5 of the nominal diameter D of the measured inner hole 12, and the relation between the specific width B and the nominal diameter D can be selectively adjusted within a limited range according to actual conditions, such as 1/2-4/5 of the nominal diameter D when the nominal diameter D is 10-20 mm. The width B is 1/3-2/3 of the nominal diameter D when the nominal diameter D is 20-100 mm. The width B is 1/4-2/3 of the nominal diameter D when the nominal diameter D is 100-200 mm. The width B is 1/5-1/3 of the nominal diameter D when the nominal diameter D is 200-500 mm. The thickness H formed by the end planes 9 of the two ends is 1/30-1/2 of the nominal diameter D of the measured inner hole 12, and when the nominal diameter D is 10-20mm, the thickness H is 1/2-1/3 of the nominal diameter D; when the nominal diameter D is 20-100mm, the thickness H is 1/3-1/10 of the nominal diameter D; when the nominal diameter D is 100-200mm, the thickness H is 1/8-1/20 of the nominal diameter D; the thickness H is 1/10-1/30 of the nominal diameter D when the nominal diameter D is 200-500 mm.

Two inclined planes 10 are also arranged between the two spherical arc working side surfaces 7 and an end plane 9 which is tightly attached to the end part of the handle 1. The included angle between the inclined surface 10 and the end plane 9 tightly attached to the end part of the handle 1 is 20-40 degrees. The two spherical arc working side surfaces 7 are respectively equal to four circular arc R angles formed between the two side planes 8, and the size of the two circular arc working side surfaces is 1-4 mm. The measuring head 4 is provided with a counter bore 11 which is through along the axial direction of the handle 1, and is arranged on the go gauge end 2 and the no-go gauge end 3 of the handle 1 through a fixing screw 5 which is matched with the counter bore 11. The handle 1 is an outer hexagonal metal section, an annular groove 6 is processed at a position close to the no-go gauge end 3, and red epoxy resin paint is coated in the annular groove 6. The depth and width of the annular groove 6 are 2-3mm respectively.

The working process of the inside diameter go-no-go gauge of the embodiment is specifically as follows:

referring to fig. 4 to 6 again, in the operation and use process, the contact between the working surface (i.e. the spherical arc working side surface 7) of the measuring head 4 of the go-no go gauge and the inner hole of the workpiece to be inspected is a set of continuously moving circular arc lines between the spherical surface and the cylindrical surface, and the circular arc diameter is the diameter of the go-no go gauge and the inner hole to be measured. Put into the bore 12 footpath internal orifice position of being surveyed that needs the inspection after the gauge head 4 that leads to rule end 2 inclines slightly earlier, sway handle 1 in order to confirm whether 4 working faces of gauge head sway through being surveyed bore 12, if the accessible, then this position leads to the rule qualified, otherwise this position diameter leads to the rule unqualifiedly, rotate certain angle again, sway the inspection and judge, accomplish the logical rule inspection of this degree of depth position different angles one by one and judge, move the logical rule to the different degree of depth positions position different degree of depth position again, accomplish the logical rule inspection of different angles one by one and judge, take out the logical rule finally. When the diameters of all the positions and angles of the go gauge inspection can pass, the go gauge inspection is judged to be qualified, if a certain position and angle exist, the go gauge cannot pass, and the position and angle range which cannot pass through the go gauge needs to be clearly recorded. Similarly, the measuring head 4 of the no-go end 3 is slightly inclined and then placed at the position of the inner opening of the diameter of the measured inner hole 12 to be checked, the handle 1 is swung to confirm whether the working surface of the measuring head 4 of the no-go end 3 swings through the measured inner hole 12, if not, if the no-go gauge can swing to pass through, the diameter of the part is unqualified, the part rotates by a certain angle, the inspection and the judgment of the swing are carried out, the inspection and the judgment of the no-go gauge at different angles of the depth position are finished one by one, the no-go gauge is moved to the part with different depths of the inner hole 12 to be tested, the inspection and the judgment of the no-go gauge at different angles are finished one by one, finally, the no-go gauge is taken out, when all the position angles of the no-go gauge inspection can be stopped, if the position and the angle of the no-go gauge pass, the position and the angle range which can pass by the no-go gauge are required to be recorded clearly, therefore, the inside diameter no-go gauge of the present embodiment can detect a non-cylindrical inner hole as shown in fig. 7 and 8. The normal go/no-go gauge 13 shown in fig. 9 is generally applicable only to diameter detection of a cylindrical inner hole as shown in fig. 10, and only a single operation method of linear reciprocating movement is available.

The inside diameter go-no-go gage of this embodiment is axial parallel translation or angular rotational position in-process and measured work piece hole nearly contactless in being surveyed hole 12, compares the face of cylinder cooperation contact's in the general go-no-go gage 13 use easy card extremely, and the go-no-go gage operation process of this embodiment is lighter swift, and the frictional wear between go-no-go gage and the measured work piece is showing and is reducing, has effectively prolonged the life of the go-no-go gage of this embodiment.

Example 2:

according to the embodiment 1, the inner diameter go-no-go gauge with specific size is provided, the technical requirement on the diameter of the measured inner hole 12 is 92(+0.05/0) mm, the diameters of the measuring heads 4 of the go-no-go gauge are respectively designed to be 92.002-92.005mm (namely the diameter of the measuring head 4 of the go-no-go end 2), the diameter of the no-go gauge is 92.047-92.050mm (namely the diameter of the measuring head 4 of the no-go end 3), the contour precision of the working surface of the go-no-go gauge is less than 0.003mm, the total thickness H of the measuring head 4 is 10mm, the width B of the measuring head 4 is 40mm, the arc width H1 of the spherical arc working side surface 7 is 5mm, and the radius of four arcs R is 3. Handle 1 is outer hexagonal hard aluminum alloy section bar, and the surface oxidation blackens and handles, and opposite side distance S equals 17mm, length 100mm, and 3 mark recesses of no-go gage end are 3mm wide, the 2mm degree of depth, apart from the no-go gage end 325mm, connect fixed gauge head 4 handle 1 with M8' S hexagon socket head cap 90 countersunk screw.

The embodiments described above are intended to facilitate the understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention according to the disclosure of the present invention.

Claims

1. The utility model provides an internal diameter leads to no-go gage, its characterized in that includes the handle, and installs two gauge heads at the logical rule end and the no-go gage end of handle respectively, and every gauge head includes along vertical and divide two concentric spherical arc work sides of putting both sides, along horizontal and divide two parallel side planes of putting both sides to and along the axial of handle and divide two parallel end planes of putting both ends, the sphere diameter of two spherical arc work sides is the same with the specification diameter of ordinary logical no-go gage and with the centrosymmetry of sphere.

2. An id go-no-go gauge as claimed in claim 1, wherein the end flats of the two define a thickness H of 1/30-1/2 of the nominal diameter D of the bore being measured.

3. An internal diameter no-go gauge according to claim 2, wherein when the nominal diameter D is 10-20mm, the thickness H is 1/2-1/3 of the nominal diameter D;

4. An id go/no-go gauge as claimed in claim 1, wherein the two side planes define a width B of 1/5-4/5 of the nominal diameter D of the bore being measured.

5. An internal diameter no-go gauge according to claim 4, wherein when the nominal diameter D is 10-20mm, the width B is 1/2-4/5 of the nominal diameter D;

6. An inner diameter go-no-go gauge according to claim 1, wherein two inclined planes are further provided between the two spherical arc working side surfaces and the end plane close to the end of the handle, and the included angle between the inclined planes and the end plane close to the end of the handle is 20-40 °.

7. An internal diameter no-go gauge according to claim 1, wherein the two spherical arc working sides are respectively equal to the R-angles of the four circular arcs formed between the two side planes, and have a size of R1-4 mm.

8. An internal diameter go-no-go gauge as claimed in claim 1, wherein the handle is a hexagonal metal section and is formed with an annular groove near the end of the no-go gauge, and the annular groove is coated with red epoxy paint.

9. An internal diameter go-no-go gauge according to claim 8, wherein the distance from the annular groove to the end face of the no-go gauge is 15-35mm, and the depth and width of the annular groove are 2-3mm, respectively.

10. An inner diameter go-no-go gauge according to claim 1, characterized in that the measuring head is provided with a countersunk hole which is axially communicated with the handle, and the countersunk hole is mounted on the go-no-go end and the no-go end of the handle through a fixing screw matched with the countersunk hole, wherein the countersunk hole is a 90-degree countersunk hole, and the fixing screw is a 90-degree hexagon socket countersunk screw.