A female thread gauge

Abstract

The utility model discloses a kind of internal thread testing tools, it is related to machining process technical field, including shaft detection main body, the shaft detection main body is equipped with a section with the continuous outer thread section of cooperation of measured internal thread part;The major diameter size of the continuous outer thread section gradually decreases along its axial direction, and the pitch diameter size of continuous outer thread section gradually increases along its axial direction;Middle diameter scale is also provided on the shaft detection main body, for indicating the pitch diameter value corresponding to different axial positions on the continuous outer thread section.The utility model not only can efficiently judge thread compliance, but also can directly read the quantitative value of pitch diameter by its integrated scale structure, combine qualitative judgment and quantitative measurement into one, greatly improve the information content and practicality of detection.

Description

Technical Field

[0001] This utility model relates to the field of machining technology, and in particular to an internal thread inspection tool. Background Technology

[0002] As a core component of machine tools, the spindle's rotational accuracy is a crucial indicator. High-speed electric spindles, in particular, have extremely high precision requirements for their key components. Specifically, the precision testing requirements for threaded mating parts mainly focus on the pitch and flank angle of the internal and external threads, as well as the fit accuracy and pitch diameter accuracy between the internal and external threads. Furthermore, the positional accuracy of the central axis formed by the threaded surfaces relative to other mating surfaces of the part is also an important testing indicator.

[0003] Currently, the inspection of internal threads mainly relies on the following two methods: Thread plug gauges are the most commonly used inspection tools, including go (T) and no-go (Z) plug gauges. Their advantages are simple operation and high efficiency. However, their disadvantages are very obvious: they can only make qualitative judgments (pass / fail), and cannot provide quantitative data (the specific pitch diameter value); for high-precision threads higher than 6H, plug gauges need to be custom-made, which is costly and time-consuming; and they completely lack the ability to inspect thread positional accuracy.

[0004] Thread measuring machines use methods such as contour probe scanning or laser scanning to accurately measure various parameters of threads. However, their disadvantages are also prominent: the equipment is expensive, with extremely high purchase and maintenance costs; it has high requirements for the operating environment and personnel skills; and its measurement efficiency is low, making it difficult to use for rapid full inspection on the production site.

[0005] Therefore, there is an urgent need in this field for a comprehensive internal thread inspection tool that can quickly determine conformity like a plug gauge, provide quantitative data, take into account positional accuracy detection, and is also low in cost and easy to operate. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide an internal thread inspection tool that can solve the technical problems of existing thread plug gauges being unable to quantitatively detect and having limited functions, as well as the high cost and low efficiency of thread measuring machines.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: An internal thread inspection tool includes a shaft-shaped inspection body, on which a continuous external thread section is provided to mate with the internal thread part being tested; the major diameter of the continuous external thread section gradually decreases along its axial direction, and the pitch diameter of the continuous external thread section gradually increases along its axial direction; the shaft-shaped inspection body is also provided with a pitch diameter scale for indicating the pitch diameter value corresponding to different axial positions on the continuous external thread section.

[0008] Furthermore, the continuous external thread segment has a guide segment and an installation segment at both ends, and the outer diameter of the guide segment and the installation segment is smaller than the minor diameter of the continuous external thread segment.

[0009] Furthermore, the major diameter generatrix of the continuous external thread segment forms a first imaginary conical surface, and the middle diameter generatrix forms a second imaginary conical surface. The taper ratio between the first and second imaginary conical surfaces is between 1:100 and 1:5000.

[0010] Furthermore, the small end of the thread pitch diameter taper of the continuous external thread and the large end of the thread major diameter taper are located on the same side; the large end of the thread pitch diameter taper and the small end of the thread major diameter taper are located on the other side.

[0011] Furthermore, the tooth profile of the continuous external thread gradually transitions from a complete tooth profile on the large end side of its major diameter taper to a truncated tooth profile on the small end side of its major diameter taper.

[0012] Furthermore, the pitch diameter scale is adjustablely mounted on the mounting section. The pitch diameter scale is a plate ruler structure with graduation lines engraved on its body. The graduation value of the graduation line is consistent with the actual pitch diameter value of the corresponding axial position of the continuous external thread section.

[0013] Furthermore, the pitch diameter scale is adjustablely mounted on the shaft detection body via an installation structure, the installation structure including a scale limit seat and a locking member; the scale limit seat is slidably mounted on the installation section, and the locking member is used to lock the scale limit seat on the installation section; the pitch diameter scale is mounted on the scale limit seat.

[0014] Furthermore, the mounting section is provided with a mounting hole extending radially therefrom and a limiting groove communicating with the mounting hole; at least a portion of the scale limiting seat is placed in the mounting hole; the locking member is threadedly connected to the scale limiting seat.

[0015] Furthermore, the shaft-shaped detection body has reference portions at both ends. The reference portions are point holes provided on the end faces of the shaft-shaped detection body. The center line connecting the two point holes forms a reference axis, which is coaxial with the axis of the continuous external thread segment.

[0016] Based on the above technical solution, the beneficial effects of this utility model are: 1. This utility model integrates the functions of a go gauge and a no-go gauge onto a thread with continuously varying dimensions, enabling rapid and comprehensive qualitative testing of the internal threads of parts. It not only efficiently determines the thread's conformity but also directly reads the quantitative value of the effective pitch diameter through its integrated scale structure, combining qualitative judgment with quantitative measurement, greatly enhancing the information content and practicality of the test.

[0017] 2. This utility model, through the precise center hole structure at both ends, allows this inspection tool to be immediately converted into a high-precision positioning reference after completing thread inspection, for detecting the positional relationship between the thread axis and other mating surfaces, such as coaxiality and perpendicularity. It is a multi-purpose tool, expanding the functional boundaries of traditional inspection tools.

[0018] 3. The overall structure of this utility model adopts a purely mechanical principle, which is stable and reliable. The manufacturing cost is far lower than that of complex electronic measuring equipment. It is suitable for rapid full inspection and accuracy analysis on the production site, and effectively solves the problem of balancing efficiency, cost and functional completeness in high-precision thread inspection. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is an enlarged view of the taper of the pitch diameter and major diameter of the continuous external thread segment 101; Figure 3 This is a structural diagram of the shaft-shaped detection body 1 of this utility model; Figure 4 This is a structural diagram of the scale limit seat 2 of this utility model; Figure 5 This is a structural diagram of the locking component 3 of this utility model; Figure 6 This is a schematic diagram of the mean diameter reading of this utility model; Figure 7 This is a schematic diagram of the detection structure of Embodiment 2 of this utility model; Figure 8 This is a schematic diagram of the shaft-shaped detection body of Embodiment 3 of this utility model; Figure 9 This is a schematic diagram of the detection structure of Embodiment 3 of this utility model.

[0020] The markings in the diagram are as follows: 1. Shaft-shaped detection body, 101. Continuous external thread section, 102. Handheld section, 103. Guide section, 104. Mounting section, 105. First center hole, 106. Second center hole, 107. Mounting hole, 108. Limiting groove, 109. Limiting step, 2. Scale limiting seat, 201. Internal threaded hole, 3. Locking element, 301. Positioning step, 4. Pitch diameter scale, 5. Cylindrical pin, 6. Internal threaded part, 7. Shaft-type part. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0022] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0023] At the same time, it should be noted that, unless otherwise stated, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] Example 1 like Figure 1-6 As shown, an internal thread inspection tool includes a shaft-shaped inspection body 1. The shaft-shaped inspection body 1 has a handheld section 102, a guide section 103, a continuous external thread section 101, and a mounting section 104 connected sequentially. The handheld section 102, guide section 103, and mounting section 104 are all cylindrical, and the outer diameter of the guide section 103 and mounting section 104 is slightly smaller than the minimum minor diameter of the continuous external thread section 101. The major diameter of the continuous external thread section 101 gradually decreases along its axial direction, while the pitch diameter gradually increases along its axial direction. The generatrix of the major diameter of the continuous external thread section 101 forms a first imaginary conical surface, and the generatrix of the pitch diameter forms a second imaginary conical surface. The taper ratio between the first and second imaginary conical surfaces is between 1:100 and 1:5000.

[0025] In the continuous external thread segment 101, the small end of the thread pitch diameter taper and the large end of the thread major diameter taper are located on the same side; the large end of the thread pitch diameter taper and the small end of the thread major diameter taper are located on the other side. Specifically, the large end diameter of the major diameter taper of the continuous external thread segment 101 is equivalent to the maximum major diameter of the corresponding grade of the go gauge; the small end diameter of the major diameter taper is equivalent to the minimum major diameter of the corresponding grade of the no-go gauge; the large end diameter of the thread pitch diameter taper is equivalent to the maximum thread pitch diameter of the corresponding grade of the no-go gauge, and the small end diameter of the thread pitch diameter taper is equivalent to the minimum thread pitch diameter of the corresponding grade of the go gauge. The section on one side where the small end of the thread pitch diameter taper and the large end of the thread major diameter are located corresponds to the go end of the corresponding grade of the gauge; the section on the other side where the large end of the thread pitch diameter taper and the small end of the thread major diameter are located corresponds to the no-go end of the corresponding grade of the gauge.

[0026] Furthermore, the tooth profile of the continuous external thread section 101 gradually transitions from the complete tooth profile on one side, which corresponds to the go end of the plug gauge, to the truncated tooth profile on the other side, which corresponds to the no end of the plug gauge. The internal threaded part should be able to be completely screwed in from the side of the complete tooth profile, and after being screwed in, it should not be able to be completely screwed out from the side of the truncated tooth profile, which is considered qualified.

[0027] In practical applications, the diameter of the large end of the tapered portion of the continuous external thread segment 101 can be adjusted so that its thread pitch diameter is smaller than the maximum thread pitch diameter of the highest precision grade no-go plug gauge, and its small end of the tapered portion is larger than the minimum thread pitch diameter of the highest precision grade go plug gauge; this further reduces the tolerance range of the thread pitch diameter of the internal thread of the part, resulting in better batch consistency of the internal thread pitch diameter of the measured part.

[0028] Furthermore, the shaft-shaped detection body 1 is also equipped with a pitch diameter scale 4, which is used to indicate the pitch diameter value corresponding to different axial positions on the continuous external thread section 101. The pitch diameter scale 4 is adjustablely mounted on the mounting section 104. Specifically, the pitch diameter scale 4 is a plate ruler structure, and its body is engraved with scale lines. The scale value of the scale lines is consistent with the actual pitch diameter value of the corresponding axial position of the continuous external thread section 101.

[0029] Specifically, the mean diameter scale 4 is adjustablely mounted on the mounting section 104 of the axial detection body 1 via the scale limit seat 2 and the locking member 3. The mounting section 104 is provided with a mounting hole 107 extending radially therein and a limiting groove 108 communicating with the mounting hole 107. The scale limit seat 2 has a square cross-section and can slide through the mounting hole 107. An internal threaded hole 201 is provided along the axial direction of the scale limit seat 2. The locking member 3 passes through the limiting groove 108 on the cylindrical surface 104, moves into the mounting hole 107, and screws into the internal threaded hole 201 on the scale limit seat 2. The locking member 3 is fixed to the scale limit seat 2 by the limiting step 109 at the end of the limiting hole 107 and the positioning step 301 on the locking member 3. The pitch diameter scale 4 is mounted on the scale limit seat 2. One end of the pitch diameter scale 4 has a pin hole, and the end of the scale limit seat 2 extending out of the mounting hole 107 has two corresponding pin holes. The cylindrical pin 5 is passed sequentially through one pin hole on the scale limit seat 2, the pin hole on the pitch diameter scale 4, and the other pin hole on the scale limit seat 2, thus fixing the pitch diameter scale 4 on the scale limit seat 2. By rotating the locking member 3, the scale limit seat 2 can be adjusted to rise or fall, thereby raising or lowering the pitch diameter scale 4.

[0030] A first center hole 105 and a second center hole 106 are respectively provided on the end face of the handheld section 102 and the mounting section 104 away from the continuous external thread section 101. The center line connecting the two center holes forms a reference axis, which is coaxial with the axis of the continuous external thread section 101.

[0031] Specifically, when the internal threaded part 6 is screwed into the small end of the pitch diameter taper of the continuous external thread section 101, if the internal threaded part 6 cannot be screwed in or cannot be fully screwed into the small end of the pitch diameter, it is equivalent to the internal threaded part 6 not being able to pass through the plug gauge end, which indicates that the functional pitch diameter and major diameter of the internal thread of the part are unqualified.

[0032] When the internal threaded part 6 is screwed into the small end of the pitch diameter taper of the continuous external thread section 101, and the internal threaded part 6 is fully screwed into the small end of the pitch diameter taper and can be fully screwed out from the large end of the pitch diameter taper, it is equivalent to the internal threaded part 6 being able to pass through the go end and the no end of the plug gauge, which indicates that the single pitch diameter of the internal thread of the part is unqualified.

[0033] The internal threaded part 6 is screwed into the small end of the pitch diameter taper of the continuous external thread section 101. When the internal threaded part 6 is fully screwed into the small end of the pitch diameter taper and cannot be fully screwed out from the large end of the pitch diameter taper, it is equivalent to the internal threaded part 6 being able to pass through the go end of the plug gauge but not through the stop end of the plug gauge, which indicates that the internal thread of the part is qualified.

[0034] When the internal threaded part 6 is screwed into the small end of the pitch diameter taper of the continuous external thread section 101, and the internal threaded part 6 is fully screwed into the small end of the pitch diameter taper but cannot be fully screwed out from the large end of the pitch diameter taper, the internal threaded part 6 will be locked at a certain position of the continuous external thread section 101 due to the pitch diameter taper of the continuous external thread section 101. This is equivalent to the effective pitch diameter of the internal thread of the part being equal to the pitch diameter of the part at that position in the continuous external thread section 101. The pitch diameter value of the internal thread of the internal threaded part 6 can then be read from the corresponding position on the pitch diameter scale 4.

[0035] This invention integrates the functions of a go gauge and a no-go gauge onto a thread with continuously varying dimensions, enabling rapid and comprehensive qualitative testing of the internal threads of parts. It not only efficiently determines thread conformity but also directly reads the quantitative value of the effective pitch diameter through its integrated scale structure, combining qualitative judgment with quantitative measurement, greatly enhancing the information content and practicality of the test.

[0036] Example 2 like Figure 7 As shown, an internal thread inspection tool is basically the same as in Embodiment 1. Further, after confirming that the internal thread part 6 is qualified, the scale limit seat 2, locking member 3, and pitch diameter scale 4 are removed. A first center hole 105 and a second center hole 106 are respectively provided on the end face of the handheld section 102 and the mounting section 104 away from the continuous external thread section 101. The center line connecting the two center holes forms a reference axis, which is coaxial with the axis of the continuous external thread section 101. The two center holes serve as reference parts, used to fix the center to a runout instrument or a machining equipment with double centers, and are used to detect the coaxiality error of other inspection surfaces relative to the central axis of the internal thread.

[0037] Specifically, after the internal threaded part 6 passes inspection, the scale limit seat 2, locking part 3, and pitch diameter scale 4 are removed. The shaft-shaped testing body 1 is placed between the two centers of the runout instrument through the first center hole 105 and the second center hole 106. The shaft-shaped testing body 1 is rotated, causing the internal threaded part 6 to rotate together, and the runout value of the outer circle of the internal threaded part 6 is tested. That is, the maximum runout of the pointer is the coaxiality error of the outer circle relative to other testing surfaces of the internal thread center axis.

[0038] Example 3 like Figure 7 As shown, an internal thread inspection tool is basically the same as in Embodiment 2. Further, after confirming that the internal thread part 6 is qualified, the internal thread part 6 is locked in a certain position at the continuous external thread end 101. The shaft-shaped inspection body 1 is fixed on a processing equipment with double centers, with the first center hole 105 and the second center hole 106 as positioning references. The shaft-shaped inspection body 1 is rotated, which drives the internal thread part 6 to rotate, and further processes other mating surfaces of the internal thread part 6. That is, it is equivalent to processing other mating surfaces of the internal thread segment of the internal thread part 6 with relative positional relationship with the continuous external thread segment 101 as reference. The force direction of the machined surface of the internal thread part 6 should be consistent with the thread locking direction to achieve the required relative positional accuracy.

[0039] This utility model, through the precise center hole structure at both ends, allows the gauge to be immediately converted into a high-precision positioning reference after completing thread inspection. It is used to detect the positional relationship between the thread axis and other mating surfaces, such as coaxiality and perpendicularity. This multi-purpose tool expands the functional boundaries of traditional gauges.

[0040] Example 4 like Figure 8-9 As shown, an internal thread inspection tool is basically the same as in Embodiment 1, but further, the taper of the continuous external thread section 101 is increased, the length of the continuous external thread section 101 is shortened, the hand-held section 102 and the guide section 103 are removed, and the mounting section 104 is lengthened, for inspecting shaft parts 7 with internal threads.

[0041] Specifically, the continuous external thread section 101 is screwed into the internal thread hole of the shaft part 7 and locked. The outer circle of the shaft part 7 is supported by a center frame. The shaft part 7 is rotated, and the runout value of the mounting section 104 of the shaft shape detection body 1 is measured with a dial indicator. The coaxiality of the internal thread hole of the shaft part 7 relative to the outer diameter of the shaft part 7 can be obtained.

[0042] The overall structure of this utility model adopts a purely mechanical principle, which is stable and reliable. Its manufacturing cost is far lower than that of complex electronic measuring equipment. It is suitable for rapid full inspection and accuracy analysis on the production site, and effectively solves the problem of balancing efficiency, cost and functional completeness in high-precision thread inspection.

[0043] It should be noted that the above embodiments are only used to illustrate the present utility model, but the present utility model is not limited to the above embodiments. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. An internal thread inspection tool, characterized in that: The device includes a shaft-shaped detection body (1), on which a continuous external thread section (101) is provided to cooperate with the internal thread part (6) being tested; the major diameter of the continuous external thread section (101) gradually decreases along its axial direction, and the pitch diameter of the continuous external thread section (101) gradually increases along its axial direction; the shaft-shaped detection body (1) is also provided with a pitch diameter scale (4) to indicate the pitch diameter value corresponding to different axial positions on the continuous external thread section (101).

2. The internal thread inspection tool according to claim 1, characterized in that: The continuous external thread section (101) has a guide section (103) and an installation section (104) at both ends, respectively. The outer diameter of the guide section (103) and the installation section (104) is smaller than the minor diameter of the thread of the continuous external thread section (101).

3. The internal thread inspection tool according to claim 2, characterized in that: The large diameter generatrix of the continuous external thread segment (101) forms a first imaginary conical surface, and the medium diameter generatrix forms a second imaginary conical surface. The taper ratio between the first and second imaginary conical surfaces is between 1:100 and 1:5000.

4. The internal thread inspection tool according to claim 1, characterized in that: The small end of the thread pitch diameter taper of the continuous external thread segment (101) and the large end of the thread major diameter taper are located on the same side; the large end of the thread pitch diameter taper and the small end of the thread major diameter taper are located on the other side.

5. The internal thread inspection tool according to claim 4, characterized in that: The tooth profile of the continuous external thread segment (101) gradually changes from the complete tooth profile on the large end side of its major diameter taper to the truncated tooth profile on the small end side of its major diameter taper.

6. The internal thread inspection tool according to claim 2, characterized in that: The pitch diameter scale (4) is adjustablely installed on the mounting section (104). The pitch diameter scale (4) is a plate ruler structure with scale lines engraved on its body. The scale value of the scale line is consistent with the actual pitch diameter value of the corresponding axial position of the continuous external thread section (101).

7. An internal thread inspection tool according to claim 6, characterized in that: The mean diameter scale (4) is adjustablely mounted on the shaft detection body (1) via an installation structure, which includes a scale limit seat (2) and a locking member (3). The scale limit seat (2) is slidably mounted on the installation section (104), and the locking member (3) is used to lock the scale limit seat (2) on the installation section (104). The mean diameter scale (4) is mounted on the scale limit seat (2).

8. An internal thread inspection tool according to claim 7, characterized in that: The mounting section (104) is provided with a mounting hole (107) extending radially therein and a limiting groove (108) communicating with the mounting hole (107); at least a portion of the scale limiting seat (2) is placed in the mounting hole (107); the locking member (3) is threadedly connected to the scale limiting seat (2).

9. An internal thread inspection tool according to claim 1, characterized in that: The shaft-shaped detection body (1) has reference parts at both ends. The reference parts are top holes set on the end faces of both ends of the shaft-shaped detection body (1). The center line of the two top holes forms a reference axis. The reference axis is coaxial with the axis of the continuous external thread segment (101).

Images