A thread pitch diameter measuring device and its assembling method and using method

Abstract

The present application relates to a kind of thread pitch diameter measuring device and its assembly method, use method;Solve the temperature error introduced by hand-held method, the theoretical position of placement needs to be adjusted repeatedly, time-consuming and labor-consuming, low efficiency and accuracy problem;Device includes first guide pillar, support frame, first connecting column, second connecting column, first positioning piece, second positioning piece, third positioning piece, first positioning ruler, second positioning ruler, first measuring needle, second measuring needle and third measuring needle;Support frame is installed on first guide pillar;First connecting column and second connecting column are installed side by side on support frame;First positioning piece is installed on first connecting column;Second positioning piece and third positioning are installed on second connecting column;First measuring needle, second measuring needle and third measuring needle are respectively installed on first positioning piece, second positioning piece and third positioning piece;First positioning ruler is arranged on the side of first positioning piece, and second positioning ruler is arranged on the side of second positioning piece and third positioning piece;The assembly and use method of device are also proposed.

Description

Technical Field

[0001] This invention belongs to the field of precision measurement technology, and relates to a thread pitch diameter measuring device and its assembly and usage methods. Background Technology

[0002] With the continuous development of the aerospace industry, the requirements for the machinery manufacturing industry are getting higher and higher, especially for threaded fasteners, which are widely used due to their simple structure, reliable connection, and convenient assembly and disassembly.

[0003] To address issues like loose or inaccurate threaded connections, precise thread measurement during manufacturing is essential. Currently, the accurate measurement of the pitch diameter of external threads generally employs the three-needle method, an indirect measurement method. During measurement, two measuring needles of the same diameter are placed in adjacent grooves on one side of the thread being measured, while a third needle is placed in the groove between the two needles on the opposite side. This position is the theoretical position. Measuring instruments for external dimensions include outside micrometers, lever micrometers, and length measuring machines. One end of the measuring instrument contacts two needles, and the other end contacts one needle, obtaining the distance between the two needles and the first needle. Then, based on the pitch, thread angle, and the diameters of the three needles, the thread pitch diameter is calculated.

[0004] Currently, when metrologists use the three-needle method to measure the pitch diameter of threads, they directly hold the three measuring needles by hand, without effectively fixing them in place. This introduces temperature errors, and the theoretical placement of the three needles requires repeated adjustments based on experience. The measurement is time-consuming and laborious, resulting in low work efficiency. In particular, the theoretical placement of the three needles requires a certain amount of training to ensure the accuracy of the measurement.

[0005] Therefore, improving the accuracy and efficiency of the three-needle method for measuring the pitch diameter of threads is an urgent problem to be solved. Summary of the Invention

[0006] The purpose of this invention is to solve the problems of temperature error introduced by the existing method of measuring with three handheld measuring needles, the need for repeated adjustments based on experience to determine the theoretical position of the three measuring needles, the time-consuming and labor-intensive nature of the measurement, low work efficiency, and low measurement accuracy. This invention proposes a thread pitch diameter measuring device and its assembly and usage methods to reduce human error, reduce environmental error, improve measurement accuracy, and increase work efficiency.

[0007] The technical solution adopted in this invention:

[0008] A thread pitch diameter measuring device, which is special in that:

[0009] It includes a first guide post, a support frame, a first connecting post, a second connecting post, a first positioning component, a second positioning component, a third positioning component, a first positioning ruler, a second positioning ruler, a first measuring needle, a second measuring needle, and a third measuring needle;

[0010] The support frame is mounted on the first guide post and can move and be fixed along the axial direction of the first guide post;

[0011] The first connecting column and the second connecting column are installed side by side on the support frame, and the first connecting column can be moved and fixed along the arrangement direction of the first connecting column and the second connecting column. The moving direction of the first connecting column is perpendicular to the moving direction of the support frame.

[0012] The first positioning element is installed on the first connecting column and can move and be fixed along the axial direction of the first connecting column. The moving direction of the first positioning element is perpendicular to the moving direction of the first connecting column and the support frame. The second positioning element and the third positioning element are installed on the second connecting column in order of distance from the support frame and can move along the axial direction of the second connecting column.

[0013] The first measuring needle, the second measuring needle, and the third measuring needle are respectively mounted on the first positioning member, the second positioning member, and the third positioning member, and the first measuring needle, the second measuring needle, and the third measuring needle are parallel to the first guide post;

[0014] The first positioning ruler is located on one side of the first positioning component to mark the position of the first measuring needle. The second positioning ruler is located on one side of the second and third positioning components to mark the positions of the second and third measuring needles. By adjusting the first, second, and third positioning components, the first, second, and third measuring needles are moved to their theoretical positions, and accurate readings can be obtained using the first and second positioning rulers. This thread pitch diameter measuring device is easy to adjust and use, improves measurement speed (increases work efficiency), enhances measurement stability, reduces the difficulty of manual operation for operators, reduces the impact of human factors on measurement quality (reduces human error), eliminates the influence of temperature fluctuations (reduces environmental error), and improves measurement accuracy.

[0015] Furthermore, in order to achieve the adjustment and measurement of the optimal position of different thread profile angles, a base and a swing block are also included;

[0016] A semi-circular notch is provided on one side of the base, and the shape of one side of the swing block is adapted to the semi-circular notch. One side of the swing block is coaxially set in the semi-circular notch of the base by a fixing member and can rotate around the fixing member. The other side is connected to the first guide post, and the axis of the first guide post is perpendicular to the axis of the semi-circular notch.

[0017] The base is provided with main engravings around its semi-circular notch, and an indicator line is provided in the middle of the corresponding position of the corner block.

[0018] Furthermore, the first positioning component includes a first bracket, a first connecting rope, a first hook mounted on the first bracket, and a first fixing component;

[0019] The first bracket is sleeved on the first connecting post and can slide and be fixed along the axial direction of the first connecting post. One end of the first connecting rope passes through the needle hole provided on the end of the first measuring needle and is connected to the other end to form a closed loop, and is then suspended on the first hook. The first fixing member is provided on the first bracket to fix the position of the first measuring needle.

[0020] Furthermore, the first positioning scale includes a first main scale and a first vernier scale;

[0021] The first main scale is mounted on the support frame and parallel to the first connecting column, and the first vernier scale is set at the corresponding position of the first bracket and the first main scale.

[0022] Furthermore, the first fixing member includes a first fixing rope and a first adjusting knob;

[0023] The first adjustment knob is installed on the side of the first bracket away from the first measuring needle. The first adjustment knob is provided with a winding groove. The first bracket is provided with a wire hole. One end of the first fixing rope is fixed and wound in the winding groove, and the other end passes through the wire hole, goes around the first measuring needle, passes through the wire hole again, and is fixed on the first bracket.

[0024] Furthermore, the first hook is mounted on the first bracket via a first slider. The first bracket is provided with a groove, and the first slider is disposed in the groove and can slide along the groove and be fixed in position. The sliding direction of the first slider is parallel to the axis of the first measuring needle.

[0025] Furthermore, the support frame includes a second guide post, a first mounting base, and a second mounting base;

[0026] The second mounting base is sleeved on the first guide post and can move and be fixed along the axial direction of the first guide post;

[0027] The second guide post is mounted on the second mounting base, the first mounting base is sleeved on the second guide post and can slide and be fixed along the axial direction of the second guide post, the first connecting post is mounted on the first mounting base, and the second connecting post is mounted on the second mounting base;

[0028] The second guide post, the first guide post, and the first connecting post are perpendicular to each other;

[0029] The first main scale is mounted on the first mounting base.

[0030] Furthermore, the structures of the second positioning member and the third positioning member are the same as those of the first positioning member; the second and third supports of the second and third positioning members, corresponding to the first support, are sequentially sleeved on the second connecting column from near to far, and can slide along the axial direction of the second connecting column;

[0031] The second positioning scale includes a second main scale and two second vernier scales;

[0032] The second main scale is installed on the second mounting base and is parallel to the second connecting column. The two second vernier scales are respectively installed at the corresponding positions of the second bracket and the third bracket in the second positioning component and the third positioning component.

[0033] The present invention also proposes an assembly method for the above-mentioned thread pitch diameter measuring device, which is characterized by including the following steps:

[0034] Step 1: Install the support frame on the first guide post;

[0035] Step 2: Install the first connecting column and the second connecting column side by side on the support frame, ensuring that the first connecting column is perpendicular to the first guide column;

[0036] Step 3: Install the first positioning component on the first connecting post, and at the same time install the second and third positioning components on the second connecting post, and install the first positioning ruler and the second positioning ruler in the corresponding positions;

[0037] Step 4: Install the first measuring needle, the second measuring needle, and the third measuring needle onto the corresponding first positioning component, the second positioning component, and the third positioning component, respectively, to complete the assembly of the thread pitch diameter measuring device.

[0038] The present invention also proposes a method for using the above-mentioned thread pitch diameter measuring device, which is characterized by including the following steps:

[0039] Step 1: Adjust and fix the positions of the first measuring needle and the second measuring needle so that the plane containing the axes of the first measuring needle and the second measuring needle is perpendicular to the first connecting post. Obtain the initial position X of the first measuring needle through the first positioning ruler and the initial position Y of the second measuring needle through the second positioning ruler.

[0040] Step 2: Based on the pitch P of the threaded part being tested, adjust the position of the third measuring needle to (Y+P), and at the same time adjust the position of the first measuring needle to (X+P / 2).

[0041] Step 3: According to the diameter D of the threaded part being tested, adjust the positions of the first, second, and third measuring needles so that the first, second, and third measuring needles are respectively embedded in the thread profile of the threaded part being tested. Measure and record the distance m between the far end of the first measuring needle and the plane containing the far ends of the second and third measuring needles.

[0042] Step 4: Based on m, calculate the mean diameter of the external thread of the threaded part being tested.

[0043] The beneficial effects of this invention are:

[0044] 1. This invention employs an indirect measurement method to achieve rapid and accurate measurement of the pitch diameter of external threads. By adjusting the first, second, and third positioning components, the first, second, and third measuring needles are moved to their theoretical positions, and precise readings can be obtained using the first and second positioning rulers. This thread pitch diameter measuring device is easy to adjust and use, improving measurement speed (increasing work efficiency), enhancing measurement stability, reducing the difficulty of manual operation for operators, reducing the impact of human factors on measurement quality (reducing human error), eliminating the influence of temperature fluctuations (reducing environmental errors), and improving measurement accuracy.

[0045] 2. In this invention, the measurement of external threads with different diameters and pitches can be completed by adjusting the positions of the first positioning component, the second positioning component and the third positioning component.

[0046] 3. In this invention, the optimal position of different thread profile angles can be adjusted and measured by setting the base and the swing block (the so-called optimal position is to make the axis of the measuring needle coincide with the angle bisector of the thread profile angle, which can be achieved by the swing of the swing block for different thread profile angles).

[0047] 4. In this invention, the first bracket is provided to provide support, and the first connecting rope ensures that the first, second, and third measuring needles are always in a natural suspension state when using the three-needle bracket adjustment device, avoiding hand operation, reducing the influence of temperature error, and improving measurement accuracy.

[0048] 5. In this invention, a vernier caliper structure is formed by the first main scale and the first vernier scale, thereby improving measurement accuracy.

[0049] 6. In this invention, the first measuring needle is fixed by a first fixing rope and a first adjusting knob, which has a simple structure and ensures that the measuring needle is in a stable state.

[0050] 7. In this invention, the height of the measuring needle can be adjusted by the set slide groove and slider structure, so that the middle part of the working surface of the measuring needle can be embedded in the thread profile of the threaded part being measured.

[0051] 8. In this invention, the second positioning scale includes a second main scale and two second vernier scales. The distance between the second measuring needle and the third measuring needle can be positioned more accurately through the same second main scale, thereby improving the accuracy of the measurement.

[0052] 9. In this invention, by moving the bracket in the first positioning member, the second positioning member, and the third positioning member, the position formed by the first measuring needle, the second measuring needle, and the third measuring needle can be any shape including an isosceles triangle, which is applicable not only to ordinary thread measurement but also to other thread measurements.

[0053] 10. The device proposed in this invention solves the problem that the theoretical positions of the three measuring needles can only be adjusted based on experience without data reference. It is not only applicable to micrometers but also to length measuring instruments such as length measuring machines. Attached Figure Description

[0054] Figure 1 This is a three-dimensional structural schematic diagram (I) of an embodiment of the present invention;

[0055] Figure 2 This is a three-dimensional structural schematic diagram (II) of an embodiment of the present invention;

[0056] Figure 3 This is a schematic diagram of the structure of the second positioning member and the third positioning member (including the second connecting column) in an embodiment of the present invention;

[0057] Figure 4 This is a schematic diagram of the structure of the first positioning member and the first positioning ruler in an embodiment of the present invention (including the second guide post, the first mounting base and the first connecting post);

[0058] Figure 5 This is a schematic diagram of the rear end structure of the first positioning member and the first positioning ruler (including the first connecting post) in an embodiment of the present invention;

[0059] Figure 6 This is a schematic diagram of the structure of the base and the swing block (including the first guide post) in an embodiment of the present invention;

[0060] In the diagram, 1. First guide post; 2. Support frame; 21. Second guide post; 22. First mounting base; 23. Second mounting base; 3. First connecting post; 4. Second connecting post; 5. First positioning component; 51. First bracket; 52. First connecting rope; 53. First hook; 54. First fixing component; 541. First fixing rope; 542. First adjusting knob; 6. Second positioning component; 7. Third positioning component; 8. First positioning scale; 81. First main scale; 82. First vernier scale; 9. Second positioning scale; 91. Second main scale; 92. Second vernier scale; 10. First measuring needle; 11. Second measuring needle; 12. Third measuring needle; 13. Base; 14. Swing block; 15. Main engraving line; 16. Indicator line; 17. First slider; 18. Second bracket; 19. Second fixing rope; 20. Third bracket. Detailed Implementation

[0061] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0062] This invention proposes a thread pitch diameter measuring device, such as... Figures 1-5 As shown, it includes a first guide post 1, a support frame 2, a first connecting post 3, a second connecting post 4, a first positioning component 5, a second positioning component 6, a third positioning component 7, a first positioning ruler 8, a second positioning ruler 9, a first measuring needle 10, a second measuring needle 11, a third measuring needle 12, a base 13, a swing block 14, and fasteners for fixing the base 13 and the swing block 14, the fasteners being fastening screws.

[0063] The composition and connection method of each component are as follows:

[0064] The first measuring needle 10, the second measuring needle 11, and the third measuring needle 12 have the same structure (same diameter).

[0065] The first positioning component 5, the second positioning component 6, and the third positioning component 7 have the same structure.

[0066] The first positioning component 5 includes a first bracket 51, a first connecting rope 52, a first slider 17, a first hook 53, and a first fixing component 54; the first fixing component 54 includes a first fixing rope 541 and a first adjusting knob 542; definition: the structure corresponding to the first bracket 51 in the second positioning component 6 is the second bracket 18, and the structure corresponding to the first fixing rope 541 is the second fixing rope 19; the structure corresponding to the first bracket 51 in the third positioning component 7 is the third bracket 20.

[0067] The first positioning ruler 8 includes a first main scale 81 and a first vernier scale 82; the support frame 2 includes a second guide post 21, a first mounting base 22 and a second mounting base 23; the second positioning ruler 9 includes a second main scale 91 and two second vernier scales 92.

[0068] The connection methods for each component are as follows:

[0069] like Figure 1 and Figure 6 As shown, the base 13 has an L-shaped structure with a semi-circular notch on one side. The swing block 14 has a semi-cylindrical structure on one side that matches the shape and size of the semi-circular notch, and a flat surface on the other side. The height of the swing block 14 is less than the distance between the lowest point of the semi-circular notch of the L-shaped structure and the other side of the L-shaped structure. One side of the swing block 14 is set inside the semi-circular notch and fixed by a fastening screw. The position of the swing block 14 can be adjusted by adjusting the tightness of the fastening screw. The other side of the swing block 14 is connected to the first guide post 1. The axis of the first guide post 1 is perpendicular to the axis of the semi-circular notch. The base 13 has a main engraving line 15 around its semi-circular notch. The minimum division value of the main engraving line 15 is 1°, and the engraving line is from -50° to +50°. An indicator line 16 is set in the middle of one side of the swing block 14.

[0070] like Figure 1 and Figure 2 As shown, the upper end of the first guide post 1 is provided with a first planar notch along the axial direction. The first planar notch serves two purposes: firstly, to fix the position of the second mounting seat 23, and secondly, to limit the stroke of the second mounting seat 23. The second mounting seat 23 is sleeved on the upper end of the first guide post 1 and can slide along the axial direction of the first guide post 1. One end of the fastening screw is connected to the second mounting seat 23 and passes through the second mounting seat 23 to abut against the first planar notch of the first guide post 1, thereby fixing the position of the second mounting seat 23.

[0071] The second guide post 21 is mounted on the second mounting base 23 and is perpendicular to the first guide post 1. The end of the second guide post 21 away from the second mounting base 23 has a second planar notch along the axial direction. The second planar notch is used to fix the position of the first mounting base 22 and to limit the stroke of the first mounting base 22. The first mounting base 22 is sleeved on the end of the second guide post 21 away from the second mounting base 23 and can slide along the axial direction of the second guide post 21. One end of the fastening screw is connected to the first mounting base 22 and passes through the first mounting base 22 to abut against the second planar notch of the second guide post 21, thereby fixing the position of the first mounting base 22.

[0072] like Figure 4 and Figure 5 As shown, the first connecting post 3 is mounted on the first mounting base 22, and the first connecting post 3 is perpendicular to the second guide post 21 and the first guide post 1. The side of the first connecting post 3 away from the second mounting base 23 is a plane. The first bracket 51 is sleeved on the first connecting post 3. The fastening screw is threaded to the first bracket 51 and passes through the first bracket 51 to abut against the plane side of the first connecting post 3. The upper end of the first bracket 51 is provided with a sliding groove with an open upper end. The first slider 17 is provided inside the sliding groove and is fixed by the corresponding fastening screw. The sliding direction of the first slider 17 is parallel to the sliding direction of the second mounting base 23. The first hook 53 is mounted on the upper end of the first slider 17 and can move with the movement of the first slider 17. The first measuring needle 10 is located on the first bracket 51 near the second mounting base 22. On one side, one end of the first connecting rope 52 passes through the needle hole of the first measuring needle 10, and the two ends are knotted to form a closed loop and hung on the first hook 53. The first adjusting knob 542 is installed on the side of the first bracket 51 away from the first measuring needle 10. The first adjusting knob 542 is provided with a winding groove. The first bracket 51 is provided with a wire hole. One end of the first fixing rope 541 is wound and fixed in the winding groove, and the other end passes through the wire hole and around the first measuring needle 10, and then passes through the wire hole again and is fixed on the first bracket 51. The first vernier scale 82 is set on the first bracket 51 and is located above the other end of the first fixing rope 541. One end of the first main scale 81 is installed on the first mounting base 22. The first main scale 81 is parallel to the first connecting post 3 and is located below the first vernier scale 82.

[0073] like Figure 3As shown, the second connecting post 4 is installed on the second mounting base 23 and is parallel to the first connecting post 3. The third positioning member 7 and the second positioning member 6 are installed on the second positioning post in the same manner as the first positioning member 5, in the direction away from the second mounting base 23. The second main scale 91 is installed on the second mounting base 23 and is parallel to the second connecting post 4. The two second vernier scales 92 are respectively installed at the corresponding positions of the second bracket 18 and the third bracket 20. The second measuring needle 11 and the third measuring needle 12 are respectively set on the corresponding second bracket 18 and the third bracket 20.

[0074] Based on the above-mentioned adjustment device, the present invention also proposes an assembly method for the above-mentioned adjustment device, comprising the following steps:

[0075] 1. For example Figure 1 and Figure 6 As shown, a semi-cylindrical swing block 14 is installed on the base 13. A main engraving line 15 is engraved on one side of the base 13. The minimum division value of the main engraving line 15 is 1°. The engraving line is from -50° to +50°. An indicator line 16 is engraved on one side of the swing block 14. The indicator line 16 can indicate the angle of swing of the swing block 14. The swing position can be fixed with fastening screws.

[0076] 2. The upper end of the swing block 14 is fixedly connected to the first guide post 1. The second mounting base 23 is fitted onto the first guide post 1 and fixed at any position by fastening screws. It is necessary to ensure that when the fastening screws are loosened, the second mounting base 23 can slide along the axial direction of the first guide post 1. The adjacent sides of the second mounting base 23 are respectively connected to the mutually perpendicular second connecting post 4 and the second guide post 21. The second connecting post 4 and the second guide post 21 are both perpendicular to the first guide post 1, so that the second connecting post 4, the second guide post 21 and the first guide post 1 form a three-dimensional structure (X, Y, Z axes) and can move along any axis.

[0077] 3. The first mounting base 22 is fitted onto the second guide post 21 and can slide on the second guide post 21. The first mounting base 22 is fixed at any position on the second guide post 21 by fastening screws. The first main scale 81 is fixed onto the first mounting base 22 by fastening screws. The first connecting post 3 is directly fixed onto the first mounting base 22. The first main scale 81 is parallel to the first connecting post 3.

[0078] 4. For example Figure 2 and Figure 4As shown, one end of the first bracket 51 is fitted onto the first connecting post 3 and can slide on the first connecting post 3, and is positioned by a fastening screw; the other end is provided with a first vernier scale 82 above the first main scale 81, and a groove is opened above the first vernier scale 82. The first slider 17 is set in the groove and can slide along the groove. The first slider 17 can be fixed at any position in the groove by a fastening screw. The upper end of the first slider 17 is fixedly connected to the first hook 53; the first connecting rope 52 passes through the needle hole of the first measuring needle 10, is knotted and hung on the first hook 53, and at the same time, the first fixing rope 541 is looped on the first measuring needle 10. One end of the rope 541 is fixed to the first bracket 51 through the wire hole, and the other end of the first fixing rope 541 is wound around the winding groove of the first adjusting knob 542 through the wire hole, and the first adjusting knob 542 is fixed to the first bracket 51. The tension of the first fixing rope 541 is adjusted by the first adjusting knob 542. The size of the first fixing rope 541 should be slightly larger than the diameter of the first measuring needle 10. The height of the first measuring needle 10 can be adjusted by sliding the first slider 17 on the groove. The height position can be fixed by the fastening screw. The first bracket 51 can be moved to the theoretical position by pushing and pulling the first bracket 51 and reading the value on the first main scale 81.

[0079] 5. For example Figure 3 As shown, the second main scale 91 is fixed to the second mounting base 23 by fastening screws, and the second main scale 91 is parallel to the second connecting post 4; one end of the second bracket 18 and the third bracket 20 are sequentially fitted onto the second connecting post 4 and can slide on the second connecting post 4, and the positions of the second bracket 18 and the third bracket 20 are fixed by fastening screws respectively; the other end is provided with a second vernier scale 92 above the second main scale 91. The structure of the second bracket 18 and the third bracket 20 is exactly the same as that of the first bracket 51, and the second measuring needle 11 and the third measuring needle 12 are installed and fixed in the same way. By pushing and pulling the second bracket 18 and the third bracket 20 and reading on the second main scale 91, the second measuring needle 11 and the third measuring needle 12 can be moved to the theoretical position.

[0080] Based on the above-described adjustment device and its assembly method, the present invention also proposes a method for applying the above-described device, comprising the following steps:

[0081] 1. First, hang the first measuring needle 10, the second measuring needle 11, and the third measuring needle 12. Move the first mounting base 22 and the first bracket 51 so that the plane containing the axis of the first measuring needle 10 and the axis of the second measuring needle 11 is perpendicular to the first connecting post 3. Secure the first bracket 51 and the second bracket 18. Read the initial position X of the first measuring needle 10 on the first vernier 82 and the initial position Y of the second measuring needle 11 on the second vernier 92.

[0082] 2. Assuming the pitch of the threaded part being tested is P, first loosen the third bracket 20 on the second connecting post 4, move the third bracket 20 to the (Y+P) position and then tighten it. Move the first bracket 51 on the first connecting post 3 to the (X+P / 2) position and then tighten it. At this time, the first measuring needle 10, the second measuring needle 11 and the third measuring needle 12 are all in the theoretical position.

[0083] 3. Based on the diameter of the threaded part being measured, move the second mounting base 23 to coarsely adjust the vertical positions of the first measuring needle 10, the second measuring needle 11, and the third measuring needle 12 so that the center of the working surface of the measuring needle coincides as much as possible with the center of the threaded part being measured. Then, adjust the positions of the sliders 17 corresponding to the first measuring needle 10, the second measuring needle 11, and the third measuring needle 12, and finely adjust the vertical positions of the first measuring needle 10, the second measuring needle 11, and the third measuring needle 12 so that the center of the working surface of the measuring needle coincides with the center of the threaded part being measured. Then, rotate... Turn the corresponding first adjustment knob 542 to fix the positions of the first measuring needle 10, the second measuring needle 11, and the third measuring needle 12 via the corresponding first fixing rope 541. Move the first mounting base 22 to embed the first measuring needle 10, the second measuring needle 11, and the third measuring needle 12 into the thread profile respectively. Use a micrometer, length measuring machine, or other length measuring instruments to measure the distance m between the plane containing the distal end of the first measuring needle 10 and the distal ends of the second and third measuring needles 11. Calculate the pitch diameter of the external thread of the threaded part being measured using the following formula:

[0084]

[0085] Where m represents the measurement value given by the micrometer or instrument, and d D The values ​​represent the diameter of the measuring needle, α is the tooth profile angle, P is the pitch, A1 is the helix angle correction value, and A2 is the measuring force correction value.

[0086] In this invention, different thread diameters can be measured by adjusting the distance between the first mounting base 22 and the second mounting base 23.

[0087] Different pitch sizes can be measured by adjusting the distance between the first bracket 51, the second bracket 18 and the third bracket 20.

[0088] The optimal position for different thread profile angles can be adjusted and measured by the tilting of the tilting block 14.

Claims

1. A thread pitch diameter measuring device, characterized in that: It includes a first guide post (1), a support frame (2), a first connecting post (3), a second connecting post (4), a first positioning component (5), a second positioning component (6), a third positioning component (7), a first positioning ruler (8), a second positioning ruler (9), a first measuring needle (10), a second measuring needle (11), and a third measuring needle (12); The support frame (2) is mounted on the first guide post (1) and can move and be fixed along the axial direction of the first guide post (1); The first connecting column (3) and the second connecting column (4) are installed side by side on the support frame (2), and the first connecting column (3) can move along the arrangement direction of the first connecting column (3) and the second connecting column (4). The moving direction of the first connecting column (3) is perpendicular to the moving direction of the support frame (2). The first positioning element (5) is installed on the first connecting column (3) and can move and be fixed along the axial direction of the first connecting column (3). The moving direction of the first positioning element (5) is perpendicular to the moving direction of the first connecting column (3) and the support frame (2). The second positioning element (6) and the third positioning element (7) are installed on the second connecting column (4) from near to far from the support frame (2) and can move along the axial direction of the second connecting column (4). The first measuring needle (10), the second measuring needle (11) and the third measuring needle (12) are respectively installed on the first positioning member (5), the second positioning member (6) and the third positioning member (7), and the first measuring needle (10), the second measuring needle (11) and the third measuring needle (12) are parallel to the first guide post (1); The first positioning ruler (8) is set on one side of the first positioning member (5) to mark the position of the first measuring needle (10). The second positioning ruler (9) is set on one side of the second positioning member (6) and the third positioning member (7) to mark the positions of the second measuring needle (11) and the third measuring needle (12). The first positioning component (5) includes a first bracket (51), a first connecting rope (52), a first hook (53), and a first fixing component (54); The first bracket (51) is sleeved on the first connecting post (3) and can slide along the axial direction of the first connecting post (3). The first hook (53) is installed on the first bracket (51) through the first slider (17). The first bracket (51) is provided with a sliding groove. The first slider (17) is provided in the sliding groove and can slide along the sliding groove and fix its position. The sliding direction of the first slider (17) is parallel to the axial direction of the first measuring needle (10). One end of the first connecting rope (52) passes through the needle hole provided on the end of the first measuring needle (10) and is connected to the other end to form a closed loop, and is then suspended on the first hook (53). The first fixing member (54) is provided on the first bracket (51) and is used to fix the position of the first measuring needle (10). The first fixing member (54) includes a first fixing rope (541) and a first adjusting knob (542); The first adjustment knob (542) is installed on the side of the first bracket (51) away from the first measuring needle (10). The first adjustment knob (542) is provided with a winding groove. The first bracket (51) is provided with a wire hole. One end of the first fixing rope (541) is fixed and wound in the winding groove. The other end passes through the wire hole and around the first measuring needle (10), then passes through the wire hole again and is fixed on the first bracket (51). The structure of the second positioning member (6) and the structure of the third positioning member (7) are the same as the structure of the first positioning member (5); the second bracket (18) and the third bracket (20) of the second positioning member (6) and the third positioning member (7) corresponding to the first bracket (51) are sequentially sleeved on the second connecting column (4) from near to far with reference to the support frame (2) and can slide and be fixed along the axis of the second connecting column (4); The first positioning scale (8) includes a first main scale (81) and a first vernier scale (82); The first main scale (81) is mounted on the support frame (2) and parallel to the first connecting column (3), and the first vernier scale (82) is set at the corresponding position of the first bracket (51) and the first main scale (81); The second positioning scale (9) includes a second main scale (91) and two second vernier scales (92); The second main scale (91) is installed on the support frame (2) and is parallel to the second connecting column (4). The two second vernier scales (92) are respectively installed at the corresponding positions of the second bracket (18) and the third bracket (20) in the second positioning component (6) and the third positioning component (7).

2. The thread pitch diameter measuring device according to claim 1, characterized in that: It also includes a base (13) and a corner block (14); The base (13) has a semi-circular notch on one side, and the shape of the swing block (14) on one side is adapted to the semi-circular notch. One side of the swing block (14) is coaxially set in the semi-circular notch of the base (13) through a fixing member and can rotate around the fixing member. The other side is connected to the first guide post (1). The axis of the first guide post (1) is perpendicular to the axis of the semi-circular notch. The base (13) has a main engraving line (15) circumferentially arranged around its semi-circular notch, and the corner block (14) has an indicator line (16) in the middle of the corresponding position.

3. The thread pitch diameter measuring device according to claim 1, characterized in that: The support frame (2) includes a second guide post (21), a first mounting base (22), and a second mounting base (23); The second mounting base (23) is sleeved on the first guide post (1) and can move and be fixed along the axial direction of the first guide post (1); The second guide post (21) is mounted on the second mounting base (23), the first mounting base (22) is sleeved on the second guide post (21) and can slide and be fixed along the axial direction of the second guide post (21), the first connecting post (3) is mounted on the first mounting base (22), and the second connecting post (4) is mounted on the second mounting base (23); The second guide post (21), the first guide post (1), and the first connecting post (3) are perpendicular to each other; The first main scale (81) is mounted on the first mounting base (22).

4. A method for assembling the thread pitch diameter measuring device according to any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Install the support frame (2) on the first guide post (1); Step 2: Install the first connecting column (3) and the second connecting column (4) side by side on the support frame (2), ensuring that the first connecting column (3) is perpendicular to the first guide column (1); Step 3: Install the first positioning piece (5) on the first connecting post (3), and at the same time install the second positioning piece (6) and the third positioning piece (7) on the second connecting post (4), and install the first positioning ruler (8) and the second positioning ruler (9) in the corresponding positions; Step 4: Install the first measuring needle (10), the second measuring needle (11) and the third measuring needle (12) on the corresponding first positioning part (5), the second positioning part (6) and the third positioning part (7) respectively to complete the assembly of the thread pitch diameter measuring device.

5. A method of using the thread pitch diameter measuring device according to any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Adjust and fix the positions of the first measuring needle (10) and the second measuring needle (11) so that the plane containing the axes of the first measuring needle (10) and the second measuring needle (11) is perpendicular to the first connecting column (3). Obtain the initial position X of the first measuring needle (10) through the first positioning ruler (8) and the initial position Y of the second measuring needle (11) through the second positioning ruler (9). Step 2: According to the pitch P of the threaded part being tested, adjust the position of the third measuring needle (12) to (Y+P), and at the same time adjust the position of the first measuring needle (10) to (X+P / 2). Step 3: According to the diameter D of the threaded part being tested, adjust the positions of the first measuring needle (10), the second measuring needle (11), and the third measuring needle (12) so that the first measuring needle (10), the second measuring needle (11), and the third measuring needle (12) are respectively embedded in the thread profile of the threaded part being tested. Measure and record the distance m between the plane where the far end of the first measuring needle (10) is located and the far ends of the second measuring needle (11) and the third measuring needle (12). Step 4: Based on m, calculate the mean diameter of the external thread of the threaded part being tested.

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