Thread detection tool and directional thread detection method

Abstract

The invention relates to a thread detection tool and a directional thread detection method. The thread testing fixture comprises an internal thread angle testing fixture and an external thread angle testing fixture, an internal thread positioned at the front part and an external thread positioning sleeve positioned at the rear part and capable of sliding are arranged in an axial through hole of an external thread testing fixture main body, and an internal thread positioning sleeve, an angle scale sleeve and a locking sleeve are sequentially arranged on the internal thread testing fixture main body in a sleeving manner; the internal thread positioning sleeve and the locking sleeve are in threaded connection with the internal thread testing fixture body, and the angle scale sleeve is in sliding connection with the internal thread testing fixture body. According to the directional thread detection method, the internal thread angle detection tool and the external thread angle detection tool in the thread detection tool are adopted for internal thread detection and external thread detection in directional threads respectively, external thread angle detection is carried out after the external threads are machined, and a due internal thread starting angle is determined; and the internal thread is machined according to the due internal thread starting angle. According to the invention, the processing of directional threads is facilitated, so that the cost is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to a thread inspection tool and a directional thread inspection method. Background Art

[0002] In some scenarios, the purpose of setting the directional / positioning thread is to ensure that the two parts have a set relative angle / posture after being screwed together. For example, after the rotating part is screwed onto the fixed part (the relatively fixed part of the two parts that are screwed together, such as the base), the front of the rotating part and the front of the base are facing the same direction, or a specific point on the rotating part is aligned with a specific point on the fixed part or is located in the same axial direction and has the same angle. Since the starting angle of internal and external thread processing (the angular position of the starting point), thread processing quality, thread fitting clearance, thread pitch and thread nominal diameter all affect the realization of the above-mentioned assembly requirements, the current processing solution is usually to process multiple samples by milling, find the processing data of the sample that meets the assembly requirements, and process according to the processing data of the sample. Therefore, the preparation cycle in production is long, raw materials are seriously wasted, and production costs are high.

[0003] On the other hand, although the existing thread ring gauge and thread plug gauge can be used as internal thread angle gauges and external thread angle gauges to detect the internal and external thread angles in directional threads respectively, after the rotating part and the fixed part are assembled through the directional thread, the relative angle (posture) between the two is affected by many factors. The effect after assembly cannot be determined based solely on the internal and external thread starting angles obtained by the test, and these gauges cannot be used to implement process detection to ensure the assembly effect after directional thread processing. Summary of the Invention

[0004] The purpose of the present invention is to provide a thread inspection tool and a corresponding directional thread inspection method that can be used for process inspection during directional thread processing, so as to facilitate the processing of directional threads, reduce costs and improve production efficiency.

[0005] The technical solution of the present invention is: a thread gauge, including an internal thread angle gauge (thread ring gauge, referred to as internal thread gauge) and an external thread angle gauge (thread plug gauge, referred to as external thread gauge), characterized in that the external thread angle gauge and the internal thread angle gauge are respectively provided with a cylindrical (or tubular, provided with an axial through hole) external thread gauge body and a cylindrical internal thread gauge body, the front part of the axial through hole of the external thread gauge body is provided with an internal thread (the internal thread parameters are determined according to the external thread parameters to be detected), the rear part of the axial through hole of the external thread gauge body (the area behind the front end internal thread in the axial through hole) is slidably connected (for example, with a clearance fit) with an external thread positioning sleeve, the external thread positioning sleeve is provided with a locking mechanism for fixing it to the external thread gauge body, the front end surface of the external thread gauge body constitutes the first positioning surface of the external thread angle gauge (which can be called the A positioning surface of the gauge assembly), and the front end surface of the external thread positioning sleeve constitutes the second positioning surface of the external thread angle gauge (which can be called the A positioning surface of the gauge assembly). (called B positioning surface of the gauge assembly), the internal thread gauge body is provided with an external thread (the external thread parameters are determined according to the internal thread parameters to be detected, for example, the rough-machined internal thread), and an internal thread positioning sleeve (or sleeve), an angle scale sleeve and a locking sleeve are sequentially sleeved on the front and back, the internal thread positioning sleeve and the locking sleeve are both provided with internal threads, which are screwed (threadedly connected) on the internal thread gauge body, and the angle scale sleeve is slidably connected to the internal thread gauge body (a movable connection method that allows the angle scale sleeve to slide on the internal thread angle gauge, for example, a clearance fit), the front end surface of the internal thread gauge body constitutes the first positioning surface of the internal thread angle gauge (which can be called the C positioning surface of the gauge assembly), and the front end surface of the internal thread positioning sleeve constitutes the second positioning surface of the internal thread angle gauge (which can be called the D positioning surface of the gauge assembly), the front end surface of the external thread gauge body and the front end surface of the internal thread gauge body are both planar (located in the same plane) and perpendicular to their respective axes.

[0006] Preferably, the front end surface of the internally threaded positioning sleeve is planar (located in the same plane) and perpendicular to its axis.

[0007] The axis of the internal thread positioning sleeve and the axis of the internal thread gauge body are located on the same straight line (or overlap).

[0008] Preferably, the outer side of the angle scale sleeve is provided with an angle scale (usually in the form of a scale). The angle scale can generally be around a circle, a 360° scale, or only in a local area in the circumferential direction, depending on actual detection needs.

[0009] The inner diameter of the angle scale sleeve may be larger (slightly larger) than the major diameter of the external thread of the internal thread gauge body, so as to allow the angle scale sleeve to slide on the internal thread gauge body and the fitting clearance is within the allowable range.

[0010] Preferably, the angle scale sleeve is provided with a locking mechanism for fixing it on the internal thread gauge body.

[0011] Preferably, the locking mechanism of the angle scale sleeve is a threaded fastening mechanism. For example, a radially extending fastening screw hole is provided on the side wall of the angle scale sleeve, and an angle scale sleeve clamping screw (or fastening screw) is screwed into the fastening screw hole on the side wall of the angle scale sleeve. The angle scale sleeve clamping screw can be regarded as a jackscrew (tightening screw). When the angle scale sleeve clamping screw is tightened, its inner end presses against the internal thread gauge body, thereby securing the angle scale sleeve to the internal thread gauge body.

[0012] The angle scale sleeve may have one or more locking mechanisms (for example, two symmetrically arranged ones).

[0013] Preferably, the front end surface of the externally threaded positioning sleeve is planar (located in the same plane) and perpendicular to its axis.

[0014] The axis of the external thread positioning sleeve and the axis of the external thread gauge body are located on the same straight line (or overlap).

[0015] Preferably, an angle scale (usually in the form of a scale) is provided at the front end (front end) of the outer side surface (outer circumference) of the external thread gauge body. The angle scale can usually be 360° around the whole circle, or it can be only in a local area in the circumferential direction, depending on actual detection needs.

[0016] The front end outer side surface of the external thread gauge body may be in the shape of a cone (a frustum), and the angle scale at the front end of the outer side surface of the external thread gauge body is arranged on the cone surface.

[0017] The outer diameter of the external thread positioning sleeve is smaller (slightly smaller) than the inner diameter of the axial through hole of the external thread gauge body in the area (active area) where it is located, thereby achieving a sliding connection between the external thread positioning sleeve and the external thread gauge body, and the fitting clearance is within the allowable range.

[0018] Preferably, the locking mechanism of the externally threaded positioning sleeve is a threaded fastening mechanism. For example, a radially extending fastening screw hole (blind hole or through hole) is provided on the side wall of the externally threaded positioning sleeve, and an externally threaded positioning sleeve tightening screw (or tightening screw) is screwed into the fastening screw hole on the side wall of the externally threaded positioning sleeve, and an axially extending strip hole (a hole with a long strip cross section, whose axial size and position should meet the sliding requirements of the externally threaded positioning sleeve) is provided on the side wall of the externally threaded gauge body, and the externally threaded positioning sleeve tightening screw passes through the corresponding strip hole on the side wall of the externally threaded gauge body, and its head is exposed outside the strip hole (or in other words, exposed outside the externally threaded gauge body) and has a size larger than the width of the strip hole (the size in the width direction of the strip hole is larger than the width of the strip hole, that is, a size / shape that does not allow it to pass through the strip hole is adopted). The externally threaded positioning sleeve tightening screw is tightened, and the head of the externally threaded positioning sleeve tightening screw is pressed on the externally threaded gauge body, thereby achieving the fixation of the externally threaded positioning sleeve on the externally threaded gauge body.

[0019] A method for detecting a directional thread, wherein the internal thread angle gauge of any thread gauge disclosed in the present invention is used to detect the internal thread in the directional thread, and the external thread angle gauge of any thread gauge disclosed in the present invention is used to detect the external thread in the directional thread. In the processing of the directional thread, the external thread is first processed. After the external thread processing is completed, the external thread angle gauge (hereinafter referred to as the external thread gauge) is used to detect the external thread angle. According to the external thread angle detection data and the design requirements of the directional thread (the relative angle / posture requirements after the rotating part and the fixing part are screwed together), the required internal thread starting angle is determined, and the internal thread is processed according to the required internal thread starting angle. The external thread angle gauge is provided with a positioning surface (axial positioning surface for screwing together) for screwing together and positioning with the external thread part (the part with the external thread). The axial position of the positioning surface on the external thread angle gauge (the axial distance relative to its front end face, when its front end face is used as the positioning surface, the axial distance can be regarded as zero) is consistent with the axial position of the corresponding positioning surface on the internal thread part (the part with the internal thread).

[0020] Furthermore, when the matching relationship between the internal and external threaded parts is that the bottom surface of the external thread and the top surface of the internal thread are positioned in contact, the first positioning surface of the external thread gauge is used as the positioning surface of the external thread gauge (the actual positioning surface during external thread detection), and the axial position of the external thread positioning sleeve is adjusted so that it does not interfere with the detection or the locking mechanism of the external thread positioning sleeve is loosened to allow the external thread positioning sleeve to move; when the matching relationship between the internal and external threaded parts is that the top surface of the external thread and the bottom surface of the internal thread are positioned, the second positioning surface of the external thread gauge is used as the positioning surface of the external thread gauge, and the axial position of the external thread positioning sleeve is adjusted or set so that the distance between the second positioning surface and the first positioning surface on the external thread gauge is equal to the designed distance between the top surface of the internal thread and the bottom surface of the internal thread on the internal threaded part (the designed depth of the internal threaded hole).

[0021] Preferably, the internal thread processing is divided into two processes (or processing steps) of internal thread rough processing and internal thread finishing, or is a single process (single internal thread processing process).

[0022] Preferably, when the internal thread processing is divided into two processes (or processing steps) of internal thread rough processing and internal thread finishing, after the internal thread rough processing is completed, an internal thread angle gauge (referred to as internal thread gauge) adapted to the corresponding internal thread size (for example, the middle diameter) is used to perform angle detection of the internal thread, and the internal thread starting angle difference (the difference between the actual starting angle and the expected starting angle, or error) is determined. According to the internal thread starting angle difference, the adjustment method (including adjustment parameters) of the internal thread starting angle during the internal thread finishing is determined, and the internal thread angle gauge is provided with a positioning surface (axial positioning surface for screwing) for screwing and positioning with the internal thread part, and the axial position (axial distance relative to its front end face) of the positioning surface on the internal thread angle gauge is consistent with the axial position of the corresponding positioning surface on the external thread part.

[0023] Furthermore, when the matching relationship between the internal and external threaded parts is that the bottom surface of the internal thread and the top surface of the external thread are in abutment and positioned, the first positioning surface of the internal thread gauge is used as the positioning surface of the internal thread gauge (the positioning surface when implementing the corresponding internal thread inspection), and the axial position of the internal thread positioning sleeve (and the angle scale sleeve, etc.) is adjusted so that it does not hinder the inspection; when the matching relationship between the internal and external threaded parts is that the bottom surface of the internal thread and the bottom surface of the external thread are in abutment and positioned, the second positioning surface of the internal thread gauge is used as the positioning surface of the internal thread gauge (the positioning surface when implementing the corresponding internal thread inspection), and the axial position of the internal thread positioning sleeve is adjusted or set so that the distance between the second positioning surface and the first positioning surface on the internal thread gauge is equal to the design distance between the top surface and the bottom surface of the external thread on the external threaded part (the design height of the external thread).

[0024] Preferably, the difference detection calibration (calibration for short) of the internal thread angle gauge is implemented based on the external thread angle gauge, and the positioning surface on the external thread angle gauge and the positioning surface on the internal thread angle gauge are set / determined according to the positioning surfaces on the internal and external threaded parts (the positioning surface setting / determination method on each gauge is consistent with the positioning surface setting / determination method when the corresponding thread detection is implemented respectively), the internal thread angle gauge is screwed onto the external thread angle gauge (the corresponding positioning surfaces are aligned), and the angle scale sleeve on the internal thread angle gauge is rotated so that its 0° scale line is aligned with the scale line on the external thread angle gauge (which can be regarded as the reference line of the angular position, or the polar axis) and the angle scale sleeve is fixed in this position (for example, fixed by a locking mechanism, and / or, the locking sleeve is appropriately tightened).

[0025] Furthermore, the scale lines on the external thread angle gauge are scale lines or scale line positions that align with the scale lines on the external thread component after the external thread angle gauge is screwed onto the external thread component. After the internal and external thread components are screwed together, the scale lines on the internal and external thread components are aligned. Depending on the product design, the scale lines on the internal and external thread components can be set at any alignment position after the internal and external thread components are screwed together.

[0026] Preferably, when inspecting the internal thread after rough machining, the internal thread angle gauge body of the internal thread angle gauge that has been calibrated by difference detection is screwed into the internal thread hole of the internal thread part, so that the positioning surface of the internal thread angle gauge is aligned with the positioning surface of the internal thread part, and the angle between the scale line on the internal thread part and the 0° scale line on the angle scale sleeve is read. This angle is the starting angle difference of the internal thread obtained by the detection, that is, the angle difference value of the internal thread fine machining adjustment.

[0027] The beneficial effects of the present invention are as follows: since the internal thread angle gauge and the external thread angle gauge are provided, the internal thread angle detection and the external thread angle detection in the directional thread can be realized respectively; by coordinating with a reasonable processing procedure, after the external thread is processed, the starting angle of the internal thread processing is determined according to the detection data of the external thread starting angle and the assembly requirements, so that the internal thread and the external thread meet the set starting angle relationship, and meet the angle / posture requirements between the two parts that are screwed together after the product is assembled; since the internal and external thread angle gauges are both provided with axially adjustable positioning sleeves, the axial position of the positioning sleeve can be adjusted according to the design requirements of the thread, thereby effectively expanding The invention has a wide range of adaptability; since the angle scale sleeve of the internal thread angle gauge is rotatable, the difference detection and calibration can be performed according to the process detection requirements of the directional thread. The internal thread angle gauge after calibration can directly read the difference of the internal thread starting angle, which reduces the data processing flow and is convenient for use; since it is only necessary to determine the parameters of the processing starting point based on the thread detection data during the rough processing and fine processing of the internal thread, there is no need to use different starting angles to process several different samples for comparison, thereby saving the time and processing costs consumed for processing the samples, and can obtain higher accuracy and precision through precise measurement and calculation, which helps to improve product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the internal thread angle gauge involved in the present invention;

[0029] Figure 2 This is a schematic diagram of the external thread angle gauge according to the present invention;

[0030] Figure 3 The invention discloses a flow chart of directional thread processing and detection involving thread detection during directional thread processing using the thread detection tool of the present invention.

[0031] Markings in the figure: 10, external thread gauge body; 11, front end face of external thread gauge body; 12, strip hole; 13, front end of the outer side face of external thread gauge body; 15, internal thread in front of the axial through hole of external thread gauge body; 20, external thread positioning sleeve; 21, front end face of external thread positioning sleeve; 24, external thread positioning sleeve clamping screw; 30, internal thread gauge body; 31, front end face of internal thread gauge body; 35, external thread on internal thread gauge body; 40, internal thread positioning sleeve; 41, front end face of internal thread positioning sleeve; 50, angle scale sleeve; 54, angle scale sleeve clamping screw; 60, locking sleeve. DETAILED DESCRIPTION

[0032] See also Figures 1 to 3 This thread gauge is an internal and external thread angle gauge assembly (or gauge assembly), including an internal thread angle gauge and an external thread angle gauge, the external thread angle gauge is provided with an external thread gauge body 10, and the internal thread angle gauge is provided with an internal thread gauge body 30. For any internal and external thread angle gauge assembly, there can be one external thread angle gauge and two internal thread angle gauges, one for rough machining internal thread angle gauge, and one for fine machining internal thread angle gauge. The thread pitch diameter of the rough machining internal thread angle gauge is smaller than the thread pitch diameter of the fine machining internal thread angle gauge, for example, 0.6mm smaller, as a fine machining allowance. The thread pitch diameters of the external thread angle gauge and the fine machining internal thread angle gauge are based on the inspection requirements of the corresponding thread design. The rough machining internal thread angle gauge can be used for process measurement after the rough machining of the internal thread is completed to determine the starting angle of the internal thread required for rough machining, and the fine machining internal thread angle gauge is used for quality inspection of the internal thread after fine machining is completed. The inspection fixture assembly may not be provided with an internal thread angle inspection fixture. Other suitable inspection fixtures may be used to inspect the quality of internal threads according to actual needs.

[0033] The external thread gauge body is cylindrical, and the front part of the axial through hole of the external thread gauge body is provided with an internal thread 15. The rear part of the axial through hole of the external thread gauge body is slidably connected (for example, with clearance fit) with an external thread positioning sleeve 20. The external thread positioning sleeve is provided with a locking mechanism for fixing it to the external thread gauge body. The front end surface 11 of the external thread gauge body constitutes the first positioning surface of the external thread angle gauge, and the front end surface 21 of the external thread positioning sleeve constitutes the second positioning surface of the external thread angle gauge.

[0034] An angle scale is provided on the front end 13 of the outer side surface of the external thread gauge body.

[0035] The locking mechanism of the externally threaded positioning sleeve is a threaded fastening mechanism. For example, a radially extending fastening screw hole is provided on the side wall of the externally threaded positioning sleeve, and a externally threaded positioning sleeve clamping screw 24 is screwed into the fastening screw hole on the side wall of the externally threaded positioning sleeve. An axially extending strip hole 12 is provided on the side wall of the externally threaded gauge body. The externally threaded positioning sleeve clamping screw passes through the corresponding strip hole on the side wall of the externally threaded gauge body, with its head exposed outside the strip hole and larger than the width of the strip hole. When the externally threaded positioning sleeve clamping screw is tightened, the head of the externally threaded positioning sleeve clamping screw is pressed against the externally threaded gauge body, thereby fixing the externally threaded positioning sleeve to the externally threaded gauge body.

[0036] Typically, when machining internal and external threads, the default starting angle is 0°. Internal and external threads are screwed in opposite directions during installation, with a 180° difference between their starting points. Therefore, to facilitate external thread machining on workpieces, the starting angle of the external thread angle gauge is set to 180°.

[0037] The main body of the external thread angle gauge includes: an angle scale for checking the angle value; an internal thread structure, which is an important part of the measurement; and the A positioning surface of the gauge, which plays a positioning role in measurement and calibration.

[0038] The external thread positioning sleeve is removable and can measure the angle of external threads with a length of 10-60mm. The B positioning surface of the gauge plays a positioning role in measurement and calibration.

[0039] The compression screw is used to secure the externally threaded positioning sleeve.

[0040] General usage of external thread angle gauge:

[0041] 1) When the internal thread positioning surface of the angle gauge is used as the positioning surface, the angle of the external thread to be measured can be directly detected and the angle deviation value can be read;

[0042] 2) When the external thread positioning surface of the angle gauge is used as the positioning surface, the external thread positioning sleeve should be adjusted to the required position first, the compression screw should be fixed, and then the angle of the external thread should be detected to read the angle deviation value.

[0043] The internal thread gauge body is provided with external threads 35, and is fitted with an internal thread positioning sleeve 40, an angle scale sleeve 50, and a locking sleeve 60 in sequence. Both the internal thread positioning sleeve and the locking sleeve are internally threaded and screwed onto the internal thread gauge body. The angle scale sleeve is slidably connected to the internal thread gauge body. The front end face 31 of the internal thread gauge body forms the first positioning surface of the internal thread angle gauge, while the front end face 41 of the internal thread positioning sleeve forms the second positioning surface of the internal thread angle gauge.

[0044] The locking mechanism of the angle scale sleeve is a threaded fastening mechanism. For example, a radially extending fastening screw hole is provided on the side wall of the angle scale sleeve. The angle scale sleeve clamping screw 54 is screwed into the fastening screw hole on the side wall of the angle scale sleeve. The angle scale sleeve clamping screw can be regarded as a jackscrew. When the angle scale sleeve clamping screw is tightened, its inner end presses against the internal thread gauge body, thereby securing the angle scale sleeve to the internal thread gauge body.

[0045] In the internal thread angle gauge, the positioning scale sleeve and the gauge body are separate, so the thread starting angle of the internal thread angle gauge does not need to be considered during the processing.

[0046] Internal thread angle gauge includes:

[0047] 1) The main body of the gauge, including: the external thread structure, which is an important part involved in measurement; the C positioning surface of the gauge, which plays a positioning role in measurement and calibration;

[0048] 2) Internal thread positioning sleeve: It moves by rotating the thread and can measure the internal thread angle of 10-60mm depth. The D positioning surface of the gauge plays a positioning role in measurement and calibration.

[0049] 3) Angle scale sleeve: rotate to adjust to zero and check the angle value;

[0050] 4) Compression screw: After the angle scale sleeve is rotated and adjusted to zero, it is used to fix it to the internal thread positioning sleeve;

[0051] 5) Locking sleeve: used to fix the internal thread positioning sleeve after calibration.

[0052] Common methods for internal thread angle gauges:

[0053] The processing flow of directional thread can be as follows: first use the rough processing gauge to make a preliminary measurement of the internal thread angle, make fine adjustments, and then perform fine processing, and then use the fine processing gauge to measure the internal thread angle; the thread diameter of the rough processing gauge is 0.6mm smaller than the normal one, which is the allowance for fine processing.

[0054] When the external thread positioning surface of the angle gauge is used as the positioning surface, the positioning sleeve of the external thread angle gauge should be adjusted to the required position first, and the internal thread angle gauge should be screwed into it. After tightening, the positioning scale sleeve of the internal thread angle gauge should be fitted with the external thread angle gauge, and the 0° scale line on the positioning scale sleeve should be aligned with the 0° scale line on the external thread angle gauge. Then, the tightening screw on the internal thread angle gauge should be tightened. Finally, the internal thread angle should be detected and the angle deviation value should be read.

[0055] When the internal thread positioning surface of the angle gauge is used as the positioning surface, the above method must also be used. First calibrate and then perform internal thread angle detection to read the angle deviation value.

[0056] When internal thread machining is divided into two steps, roughing and finishing, the internal thread angle is initially measured using an internal thread angle gauge suitable for the rough-machined internal thread. In the subsequent finishing process, the starting angle is fine-tuned based on the preliminary measurement data. After finishing, the internal thread angle is measured again using an internal thread gauge suitable for the finished internal thread. The pitch diameter of the internal thread gauge used after roughing is 0.6mm smaller than that used for normal thread inspection (for example, after finishing). This is the finishing allowance.

[0057] Processing and inspection process of directional thread:

[0058] 1. External threaded parts

[0059] 1) External thread milling and measurement: The dimensional accuracy of the external thread of the part is measured using a thread ring gauge of relevant accuracy. The go gauge is required to pass and the stop gauge is required to stop. When machining the external thread first, the preset value of the thread machining starting angle can be set to 0°.

[0060] 2) According to the matching relationship, use the external thread angle inspection tool to inspect the finished external thread parts.

[0061] i) When the fitting relationship is that the bottom surface of the external thread of the part is in contact with the top surface of the internal thread, first loosen the two clamping screws on the external thread angle gauge, then screw the external thread of the part completely into the external thread angle gauge so that the bottom surface of the external thread of the part is in contact with the positioning surface A of the gauge, read the angle scale value, and then calculate the starting angle of the internal thread processing according to the assembly angle requirements of the drawing;

[0062] ii) When the fitting relationship is that the top surface of the external thread of the part is positioned against the bottom surface of the internal thread, first loosen the two clamping screws on the external thread angle gauge, adjust the external thread positioning sleeve of the gauge so that the dimension between the positioning surface A and the positioning surface B of the gauge is consistent with the depth dimension of the internal thread hole to be measured, then tighten the two clamping screws on the external thread angle gauge, and then screw the external thread of the part into the main body of the external thread angle gauge so that the top surface of the external thread of the part is firmly positioned against the positioning surface B of the gauge, read the angle scale value, and then calculate the starting angle for internal thread processing according to the assembly angle requirements of the drawing.

[0063] 2. Internal thread parts

[0064] 1) The calculation method for the starting angle of internal thread rough machining is: internal thread rough machining starting angle = 180° ± the angle measured by the external thread angle gauge ± the assembly angle.

[0065] 2) Use the calculated internal thread roughing starting angle to perform rough milling on the internal thread, leaving a 0.3mm margin on one side, and use the roughing internal thread starting angle gauge for process measurement.

[0066] 3) Process measurement: According to the matching relationship, use the external thread angle gauge to calibrate the internal thread angle gauge.

[0067] i) When the mating relationship is that the bottom surface of the internal thread of the part is positioned in contact with the upper end surface of the external thread:

[0068] a) First, loosen the two clamping screws on the external thread angle gauge, adjust the position of the external thread positioning sleeve of the gauge so that the size between the positioning surface of the gauge A and the positioning surface of the gauge B is consistent with the internal thread depth size of the part, then tighten the two clamping screws on the external thread angle gauge, and then screw the internal thread angle gauge body into the external thread angle gauge body so that the positioning surface C of the internal thread angle gauge is firmly positioned with the positioning surface B of the external thread gauge. Adjust the position of the internal thread positioning sleeve and the angle scale sleeve so that the positioning surface D of the gauge is 3-5mm away from the positioning surface A of the gauge, and tighten the locking sleeve to fix it. Then loosen the clamping screw on the internal thread angle gauge, align the 0° scale line of the angle scale sleeve with the scale line of the external thread angle gauge (check the drawing requirements), and finally tighten the clamping screw to complete the calibration of the internal thread angle gauge.

[0069] b) Screw the calibrated internal thread angle gauge body into the threaded inner hole of the part to be measured, so that the positioning surface C of the gauge is firmly attached to the bottom surface of the threaded hole of the part. Read the difference between the angle mark on the part (reference line / base line of the angle position) and the 0° line of the gauge to obtain the angle difference value for the internal thread finishing.

[0070] ii) When the matching relationship is that the upper end face of the internal thread of the part is in contact with the lower bottom face of the external thread:

[0071] a) First, loosen the two clamping screws on the external thread angle gauge, adjust the position of the external thread positioning sleeve of the gauge so that the size between the positioning surface of the gauge A and the positioning surface of the gauge B is consistent with the external thread height size of the part, then tighten the two clamping screws on the external thread angle gauge, and then screw the internal thread angle gauge body into the external thread angle gauge body so that the positioning surface C of the internal thread angle gauge is firmly positioned with the positioning surface B of the external thread gauge, adjust the position of the internal thread positioning sleeve and the angle scale sleeve so that the positioning surface D of the gauge is also firmly positioned with the positioning surface A of the gauge, and tighten the locking sleeve to fix it, then loosen the clamping screw on the internal thread angle gauge, align the 0° scale line of the angle scale sleeve with the scale line of the external thread angle gauge (check the drawing requirements), and finally tighten the clamping screw to complete the calibration of the internal thread angle gauge;

[0072] b) Screw the calibrated internal thread angle gauge body into the threaded inner hole of the part to be measured, so that the D positioning surface of the gauge is firmly attached to the bottom surface of the threaded hole of the part, read the difference between the angle mark on the part and the 0° line of the gauge, and obtain the angle difference value adjusted for internal thread finishing.

[0073] 4) Compare the internal and external thread angle gauge values, determine the difference, and calculate the starting angle for the finished thread. The calculation method is: the starting angle for the finished thread = the angle value of the rough milled internal thread ± the angle difference measured by the roughing gauge.

[0074] 5) Based on the calculated finishing angle parameters, correct the value of the thread machining starting point in the CNC machining program within the finishing allowance range. The calculation method is: Adjustable angle range = ± (single-side finishing allowance × tan30 × 360 / pitch). Adjustments outside the adjustable angle range will result in scrap.

[0075] 6) Measure the dimensional accuracy of the internal thread processing and use a thread plug gauge of relevant accuracy for inspection. The go gauge is required to pass and the stop gauge is required to stop. Measure the assembly angle of the internal thread and use the internal thread angle gauge for fine processing for inspection. The calibration process and measurement method are the same as those for the internal thread angle gauge for rough processing, so they will not be repeated here. One thing to note here is that when the angle of the measured result is out of tolerance, if the 0° line of the gauge is to the right of the angle mark of the part, it cannot be adjusted and the part will be scrapped. If the 0° line of the gauge is to the left of the angle mark of the part, the assembly angle can be slightly adjusted using the following method.

[0076] 7) Micro-adjustment of angle after finishing. The specific method is as follows:

[0077] i) If the internal thread machining dimensional accuracy is qualified but does not meet the assembly angle requirement, the upper side of the thread profile needs to be adjusted. The formula is: Upper side profile adjustment = minimum angle difference / 360 × pitch, where the minimum angle difference refers to the minimum angle movement on the current angle deviation to meet the angle range required on the drawing. For example, if the minimum angle difference is 10° and the pitch is 1.5mm, then the upper side profile adjustment = 10 / 360 × 1.5 ≈ 0.042mm, that is, the machine tool Z axis should be raised 0.042mm before processing;

[0078] If the assembly angle requirement has been met but the thread size accuracy has not been met, the lower side needs to be corrected while ensuring the thread depth. That is, the Z axis of the machine tool should be lowered by a certain value before processing. The specific value depends on the actual situation.

[0079] External thread processing process flow chart:

[0080]

[0081]

[0082] External thread processing process flow chart:

[0083]

[0084]

[0085] The milling process referred to in the present invention includes commonly known milling process, and also includes other processing means capable of performing the required thread processing.

[0086] Unless otherwise specified or when one preferred or optional technical means is a further limitation of another technical means, the preferred and optional technical means disclosed in the present invention can be arbitrarily combined to form several different specific implementation methods.

Claims

1. Thread gauge, including internal thread angle gauge and external thread angle gauge, characterized by The external thread angle gauge and the internal thread angle gauge are respectively provided with a cylindrical external thread gauge body and a cylindrical internal thread gauge body, the front part of the axial through hole of the external thread gauge body is provided with an internal thread, the rear part of the axial through hole of the external thread gauge body is provided with an external thread positioning sleeve, the external thread positioning sleeve is provided with a locking mechanism for fixing it to the external thread gauge body, the front end surface of the external thread gauge body constitutes the first positioning surface of the external thread angle gauge, the internal thread gauge body is provided with an external thread, and is sleeved in sequence front and back. There are an internal thread positioning sleeve, an angle scale sleeve and a locking sleeve. The internal thread positioning sleeve and the locking sleeve are both provided with internal threads and screwed onto the internal thread gauge body. The angle scale sleeve is slidably connected to the internal thread gauge body. The front end surface of the internal thread gauge body constitutes the first positioning surface of the internal thread angle gauge, and the front end surface of the internal thread positioning sleeve constitutes the second positioning surface of the internal thread angle gauge. The front end surface of the external thread gauge body and the front end surface of the internal thread gauge body are both planar and perpendicular to their respective axes.

2. The thread gauge according to claim 1, characterized in that The angle scale sleeve is provided with a locking mechanism for fixing it on the internal thread gauge body.

3. The thread gauge according to claim 1, characterized in that The front end surface of the internal thread positioning sleeve is planar and perpendicular to its axis.

4. The thread gauge according to claim 1, characterized in that The front end surface of the external thread positioning sleeve is planar and perpendicular to its axis.

5. Directional thread detection method, characterized in that The internal thread angle gauge in the thread gauge according to any one of claims 1 to 4 is used to detect the internal thread in the directional thread, and the external thread angle gauge in the thread gauge according to any one of claims 1 to 4 is used to detect the external thread in the directional thread. In the processing of the directional thread, the external thread is processed first, and after the external thread processing is completed, the external thread angle gauge is used to detect the external thread angle. According to the external thread angle detection data and the design requirements of the directional thread, the required internal thread starting angle is determined, and the internal thread is processed according to the required internal thread starting angle. The external thread angle gauge is provided with a positioning surface for screwing and positioning with the external thread part, and the axial position of the positioning surface on the external thread angle gauge is consistent with the axial position of the corresponding positioning surface on the internal thread part.

6. The directional thread detection method according to claim 5, characterized in that When the matching relationship between the internal and external threaded parts is that the bottom surface of the external thread and the top surface of the internal thread are positioned in contact, the first positioning surface of the external thread gauge is used as the positioning surface of the external thread gauge, and the axial position of the external thread positioning sleeve is adjusted so that it does not interfere with the inspection or the locking mechanism of the external thread positioning sleeve is loosened to allow the external thread positioning sleeve to move; when the matching relationship between the internal and external threaded parts is that the top surface of the external thread and the bottom surface of the internal thread are positioned, the second positioning surface of the external thread gauge is used as the positioning surface of the external thread gauge, and the axial position of the external thread positioning sleeve is adjusted or set so that the distance between the second positioning surface and the first positioning surface on the external thread gauge is equal to the designed distance between the top surface of the internal thread and the bottom surface of the internal thread on the internal threaded part.

7. The directional thread detection method according to claim 5, characterized in that Internal thread processing is divided into two processes: internal thread rough processing and internal thread finishing, or is one process. Under the circumstance that the internal thread processing is divided into two processes: internal thread rough processing and internal thread finishing, after the internal thread rough processing is completed, an internal thread angle gauge adapted to the corresponding internal thread size is used to detect the angle of the internal thread to determine the difference in the starting angle of the internal thread. The adjustment method of the starting angle of the internal thread during the internal thread finishing is determined based on the difference in the starting angle of the internal thread. The internal thread angle gauge is provided with a positioning surface for screwing and positioning with the internal thread part, and the axial position of the positioning surface on the internal thread angle gauge is consistent with the axial position of the corresponding positioning surface on the external thread part.

8. The directional thread detection method according to claim 5, characterized in that When the matching relationship between the internal and external threaded parts is that the internal thread bottom surface and the external thread top surface are fitted and positioned, the first positioning surface of the internal thread gauge is used as the positioning surface of the internal thread gauge, and the axial position of the internal thread positioning sleeve is adjusted so that it does not hinder the detection; when the matching relationship between the internal and external threaded parts is that the internal thread bottom surface and the external thread bottom surface are fitted and positioned, the second positioning surface of the internal thread gauge is used as the positioning surface of the internal thread gauge, and the axial position of the internal thread positioning sleeve is adjusted or set so that the distance between the second positioning surface and the first positioning surface on the internal thread gauge is equal to the designed distance between the external thread top surface and the external thread bottom surface on the external threaded part.

9. The directional thread detection method according to claim 5, characterized in that Based on the external thread angle gauge, the difference detection and calibration of the internal thread angle gauge is implemented. The positioning surfaces on the external thread angle gauge and the positioning surfaces on the internal thread angle gauge are set / determined according to the positioning surfaces on the internal and external threaded parts. The internal thread angle gauge is screwed onto the external thread angle gauge. The angle scale sleeve on the internal thread angle gauge is rotated so that its 0° scale line is aligned with the scale line on the external thread angle gauge and the angle scale sleeve is fixed in this position.

10. The directional thread detection method according to claim 9, characterized in that When inspecting the internal thread after rough machining, screw the internal thread angle gauge body of the internal thread angle gauge that has been calibrated by difference detection into the internal thread hole of the internal thread part, so that the positioning surface of the internal thread angle gauge is aligned with the positioning surface of the internal thread part, and read the angle between the scale line on the internal thread part and the 0° scale line on the angle scale sleeve. This angle is the starting angle difference of the internal thread obtained by the detection, that is, the angle difference adjusted for internal thread finishing.

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