A method and tool for measuring external threads

Abstract

The application provides a stepped external thread measuring method and a measuring tool. The stepped external thread measuring tool comprises a threaded section TH1, a threaded section TH2, a threaded section ZH1, a threaded section ZH2 and a threaded section ZH3. The threaded section TH1 is used for judging whether the third flank profile, the second flank profile and the fifth flank profile are out of the tolerance band range. The threaded section TH2 is used for judging whether the first flank profile and the fifth flank profile are out of the tolerance band range. The threaded section ZH1 is used for judging whether the third flank profile and the fifth flank profile are out of the tolerance band range. The threaded section ZH2 is used for judging whether the second flank profile and the fifth flank profile are out of the tolerance band range. The threaded section ZH3 is used for judging whether the first flank profile and the fifth flank profile are out of the tolerance band range. The measuring tool does not need auxiliary equipment to participate, and the measuring process is simple. The measuring efficiency can be improved, and the measuring cost can be effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical manufacturing, and particularly relates to a stepped external thread measuring method and a measuring tool. BACKGROUND

[0002] Threaded connection structures are widely used in the fields of machinery, transportation, construction, aviation, aerospace, ships, furniture, etc. due to the advantages of low cost, convenient disassembly and assembly, and large connection force. However, in the actual use process, the threaded connection structure is very easy to loosen due to various complex working conditions such as vibration and impact. Thread loosening not only reduces the connection force, leading to connection failure, but also causes serious safety accidents. Therefore, it is necessary to adopt certain anti-loosening measures.

[0003] A Chinese invention ZL2020207103546 discloses a kind of anti-loosening thread containing stepped structure, which is referred to as stepped thread here, the stepped thread has excellent anti-loosening effect and can effectively solve the loosening problem of threaded connection. However, due to the small size of the step in the stepped structure, the measurement of the stepped thread is difficult, which directly affects the product quality and production efficiency. SUMMARY

[0004] The present application provides a stepped external thread measuring method and a measuring tool to solve the technical problem that the measurement process of the stepped thread is difficult.

[0005] The first aspect of the present application provides a pin thread measuring tool for measuring a pin thread, the tooth profile line of the pin thread comprising a first flank profile line, a second flank profile line, a third flank profile line, a fourth crest profile line, a fifth flank profile line and a sixth root profile line connected in sequence; wherein the first flank profile line, the second flank profile line and the third flank profile line are sequentially connected to form a stepped generatrix; characterized in that the pin thread measuring tool comprises a through-end ring gauge and a dead-end ring gauge; the through-end ring gauge comprises a threaded segment TH1 and a threaded segment TH2; wherein the threaded segment TH1 is used to determine whether the second flank profile line, the third flank profile line and the fifth flank profile line of the tooth profile line of the pin thread exceed the tolerance band range from the side of the maximum solid tooth profile of the pin thread; the threaded segment TH2 is used to determine whether the first flank profile line and the fifth flank profile line of the tooth profile line of the pin thread exceed the tolerance band range from the side of the maximum solid tooth profile of the pin thread; the dead-end ring gauge comprises a threaded segment ZH1, a threaded segment ZH2 and a threaded segment ZH3; wherein the threaded segment ZH1 is used to determine whether the third flank profile line and the fifth flank profile line of the tooth profile line of the pin thread exceed the tolerance band range from the side of the minimum solid tooth profile of the pin thread; the threaded segment ZH2 is used to determine whether the second flank profile line and the fifth flank profile line of the tooth profile line of the pin thread exceed the tolerance band range from the side of the minimum solid tooth profile of the pin thread; the threaded segment ZH3 is used to determine whether the first flank profile line and the fifth flank profile line of the tooth profile line of the pin thread exceed the tolerance band range from the side of the minimum solid tooth profile of the pin thread.

[0006] In some possible implementation manners, the profile line of the design tooth profile of the threaded segment TH1 comprises a flank profile line TH1-1, a flank profile line TH1-2, a flank profile line TH1-4 and a root profile line TH1-5; wherein, in the case that the pin thread and the threaded axis of the threaded segment TH1 coincide: the flank profile line TH1-1 can completely contain the third flank profile line of the maximum solid tooth profile of the pin thread, and at the same time the flank profile line TH1-2 completely contains the second flank profile line of the maximum solid tooth profile of the pin thread, and at the same time the flank profile line TH1-4 partially coincides with the fifth flank profile line of the maximum solid tooth profile of the pin thread, and at the same time the root profile line TH1-5 has a first preset distance from the fourth crest profile line of the maximum solid tooth profile of the pin thread.

[0007] In some possible implementation manners, the profile line of the design tooth profile of the threaded segment TH1 further comprises a crest profile line TH1-3, the crest profile line TH1-3 being connected between the flank profile line TH1-2 and the flank profile line TH1-4, and the crest profile line TH1-3 being outside the tolerance band of the pin thread.

[0008] In some possible implementation manners, the profile line of the design tooth profile of the threaded segment TH2 includes a flank profile line TH2-1, a flank profile line TH2-3, a crest profile line TH2-2, and a root profile line TH2-4; wherein, in the case that the thread axis of the stepped-out thread and the threaded segment TH2 coincide: the flank profile line TH2-1 can completely contain the first flank profile line of the maximum solid tooth profile of the stepped-out thread, and meanwhile the flank profile line TH2-3 completely contains the fifth flank profile line of the maximum solid tooth profile of the stepped-out thread, and meanwhile the crest profile line TH2-2 is outside the tolerance band of the stepped-out thread, and meanwhile the root profile line TH2-4 has a second preset distance from the fourth crest profile line of the maximum solid tooth profile of the stepped-out thread.

[0009] In some possible implementation manners, the profile line of the design tooth profile of the threaded segment ZH1 includes a flank profile line ZH1-1, a flank profile line ZH1-3, a crest profile line ZH1-2, and a root profile line ZH1-4; wherein, in the case that the thread axis of the stepped-out thread and the threaded segment ZH1 coincide: the flank profile line ZH1-1 can partially coincide with the third flank profile line of the minimum solid tooth profile of the stepped-out thread, and meanwhile the flank profile line ZH1-3 partially coincides with the fifth flank profile line of the minimum solid tooth profile of the stepped-out thread, and meanwhile the crest profile line ZH1-2 does not intersect the second flank profile line of the minimum solid tooth profile of the stepped-out thread, and meanwhile the crest profile line ZH1-2 also does not intersect the second flank profile line of the maximum solid tooth profile of the stepped-out thread, and meanwhile the root profile line ZH1-4 has a third preset distance from the fourth crest profile line of the maximum solid tooth profile of the stepped-out thread.

[0010] In some possible implementation manners, the profile line of the design tooth profile of the threaded segment ZH2 includes a flank profile line ZH2-1, a flank profile line ZH2-2, a flank profile line ZH2-4, and a root profile line ZH2-5; wherein, in the case that the thread axis of the stepped-out thread and the threaded segment ZH2 coincide: the flank profile line ZH2-2 can partially coincide with the second flank profile line of the minimum solid tooth profile of the stepped-out thread, and meanwhile the flank profile line ZH2-4 partially coincides with the fifth flank profile line of the minimum solid tooth profile of the stepped-out thread, and meanwhile the distance between the flank profile line ZH2-1 and the third flank profile line of the maximum solid tooth profile of the stepped-out thread in the direction of the thread axis is greater than the width of the tolerance band of the stepped-out thread in the direction of the thread axis, and meanwhile the root profile line ZH2-5 has a fourth preset distance from the fourth crest profile line of the maximum solid tooth profile of the stepped-out thread.

[0011] In some possible implementation manners, the profile line of the design tooth profile of the threaded segment ZH2 further includes a crest profile line ZH2-3, which is connected between the flank profile line ZH2-2 and the flank profile line ZH2-4.

[0012] In some possible implementation manners, the profile line of the designed tooth profile of the thread segment ZH3 includes a flank profile line ZH3-1, a flank profile line ZH3-3, a crest profile line ZH3-2, and a root profile line ZH3-4; and in the case where the thread axis of the step-out thread and the thread segment ZH3 coincide, the flank profile line ZH3-1 can completely contain the first flank profile line of the minimum solid tooth profile of the step-out thread, and at the same time, the flank profile line ZH3-3 completely contains the fifth flank profile line of the minimum solid tooth profile of the step-out thread, and at the same time, the root profile line ZH3-4 has a fifth preset distance with the fourth crest profile line of the maximum solid tooth profile of the step-out thread.

[0013] The step-out thread measuring tool provided in the first aspect of the present application can detect different tooth profile lines of the measured step-out thread by combining the gauges, without the participation of auxiliary equipment, and the measuring process is simple, which can improve the measuring efficiency and effectively reduce the measuring cost. Moreover, the step-out thread measuring tool is designed in the form of a combined gauge, which can effectively ensure the service life.

[0014] The step-out thread measuring method provided in the second aspect of the present application is applied to the step-out thread measuring tool provided in the first aspect, and is used for measuring a step-out thread. The step-out thread measuring method includes the following steps: the through-end ring gauge and the dead-end ring gauge are respectively screwed with the step-out thread; when the two thread segments of the through-end ring gauge can be screwed into the step-out thread, and the three thread segments of the dead-end ring gauge cannot be screwed into the step-out thread, it is determined that the actual size of the step-out thread is within the allowable tolerance range.

[0015] In some possible implementation manners, the step-out thread measuring method further includes the following steps: when any one of the thread segments of the through-end ring gauge cannot be screwed into the step-out thread, or any one of the thread segments of the dead-end ring gauge can be screwed into the step-out thread, it is determined that the actual size of the step-out thread is not within the allowable tolerance range.

[0016] The step-out thread measuring method provided in the second aspect of the present application can conveniently and quickly determine whether the size of the measured step-out thread is qualified, has the advantages of high measuring accuracy and high efficiency, and is simple, easy to implement, and convenient to operate, and does not require any auxiliary equipment, thereby effectively reducing the measuring cost. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, other drawings can also be obtained by those skilled in the art without any creative labor under the premise of these drawings.

[0018] Figure 1is a design tooth profile structure schematic diagram of a stepped external thread provided by an embodiment of the present application;

[0019] Figure 2 is a tolerance band structure schematic diagram of a stepped external thread provided by an embodiment of the present application;

[0020] Figure 3 is a cross-sectional schematic diagram of a through-thread axis of a go gauge provided by an embodiment of the present application;

[0021] Figure 4 is a cross-sectional schematic diagram of a through-thread axis of a stop gauge provided by an embodiment of the present application;

[0022] Figure 5 is a design tooth profile structure schematic diagram of a threaded segment TH1 provided by an embodiment of the present application;

[0023] Figure 6 is a design tooth profile structure schematic diagram of a threaded segment TH2 provided by an embodiment of the present application;

[0024] Figure 7 is a design tooth profile structure schematic diagram of a threaded segment ZH1 provided by an embodiment of the present application;

[0025] Figure 8 is a design tooth profile structure schematic diagram of a threaded segment ZH2 provided by an embodiment of the present application;

[0026] Figure 9 is a design tooth profile structure schematic diagram of a threaded segment ZH3 provided by an embodiment of the present application;

[0027] Figure 10 is a flow schematic diagram of a stepped external thread measurement method provided by an embodiment of the present application.

[0028] Illustration mark:

[0029] 21-first tooth flank profile line; 22-second tooth flank profile line; 23-third tooth flank profile line; 24-fourth tooth crest profile line; 25-fifth tooth flank profile line; 26-sixth tooth root profile line; L1-thread axis;

[0030] Minimum solid tooth flank: 21-1-first tooth flank profile line; 22-1-second tooth flank profile line; 23-1-third tooth flank profile line; 24-1-fourth tooth crest profile line; 25-1-fifth tooth flank profile line; 26-1-sixth tooth root profile line;

[0031] Maximum solid tooth flank: 21-2-first tooth flank profile line; 22-2-second tooth flank profile line; 23-2-third tooth flank profile line; 24-2-fourth tooth crest profile line; 25-2-fifth tooth flank profile line; 26-2-sixth tooth root profile line;

[0032] TH - end ring gauge; TH1, TH2 - threaded section of the end ring gauge; ZH - end ring gauge; ZH1, ZH2, ZH3 - threaded section of the end ring gauge. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments of the present application, other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0034] Hereinafter, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", and the like can explicitly or implicitly include one or more features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0035] In addition, in the present application, the orientation terms such as "upper", "lower", "inner", "outer" and the like are defined with respect to the orientation of the components shown in the drawings, and it should be understood that these directional terms are relative concepts, which are used for relative description and clarification, and can be changed accordingly according to the change of the orientation of the components placed in the drawings.

[0036] The threaded connection structure is widely used in the fields of machinery, transportation, construction, aviation, aerospace, shipbuilding, furniture and the like due to its low cost, easy disassembly and assembly, and large connection force. However, in actual use, due to various complex working conditions such as vibration and impact, the threaded connection structure is very easy to loosen. Thread loosening not only reduces the connection force and causes connection failure, but also causes serious safety accidents, so it is necessary to adopt certain anti-loosening measures.

[0037] There is a step-shaped anti-loosening thread in the existing design, which is referred to as a step thread in the present application, which has excellent anti-loosening effect and can effectively solve the loosening problem of threaded connection. The step thread includes a step external thread and a step external thread. Due to the small size of the step, the measurement of the step thread is difficult, which can easily lead to the missed detection of unqualified products, and also limits the equipment debugging speed during production, resulting in low production efficiency.

[0038] In order to solve the above technical problems, the present application provides a step external thread measurement method, which has the advantages of simple and easy operation, convenient operation, high measurement accuracy, low cost and high efficiency.

[0039] Firstly, the terms related to threads used in the present application are defined as follows.

[0040] The stepped thread described in the present application refers to the thread provided with a stepped structure described in Chinese invention ZL2020207103546, specifically, it can be the thread of the third threaded part or the fourth threaded part described in Chinese invention ZL2020207103546 when provided with a stepped structure. Specifically, the stepped thread in the present application is a stepped external thread.

[0041] Figure 1 is a schematic diagram of the design tooth profile structure of a stepped external thread provided by an embodiment of the present application.

[0042] Referring to Figure 1 , the tooth profile line of the stepped external thread includes a first tooth flank profile line, a second tooth flank profile line, a third tooth flank profile line, a fourth tooth crest profile line, a fifth tooth flank profile line, and a sixth tooth root profile line; wherein the first tooth flank profile line, the second tooth flank profile line, and the third tooth flank profile line are sequentially connected to form a stepped generatrix, i.e. the profile shape of the tooth flank containing a step in the axial plane of the stepped external thread; the fifth tooth flank profile line is the profile shape of the tooth flank not containing a step in the axial plane of the stepped external thread.

[0043] Various terms related to conventional threads and stepped threads used in the present application, if provided in the national standard GB / T14791-2013, then in the absence of special instructions, the definitions in the national standard GB / T 14791-2013 can be adopted, such as tooth root, tooth flank, tooth crest, pitch, major diameter, minor diameter, tooth body, tooth profile, design tooth profile, etc. These thread-related terms are also common knowledge to those skilled in the art, and their specific definitions will not be repeated here.

[0044] The special terms related to stepped threads described in the present application, if provided in Chinese invention ZL2020207103546, then in the absence of special instructions, the definitions in Chinese invention ZL2020207103546 are preferred, such as stepped structure, stepped generatrix, etc. The specific definitions of these terms will not be repeated here.

[0045] It needs to be specially pointed out that the tooth flanks of the stepped thread in the present application refer to the helical surfaces on both sides of the tooth body of the stepped thread, and the stepped thread in the present application has two tooth flanks, one of which is a tooth flank not containing a step (i.e. a tooth flank not containing a stepped structure), and the other of which is a tooth flank containing a step (i.e. a tooth flank containing a stepped structure). The two tooth flanks of the conventional thread are both linear in the axial plane, the tooth flank of the stepped thread not containing a step is linear in the axial plane, and the tooth flank containing a step is curved in the axial plane, specifically, it contains the stepped generatrix described in Chinese Invention ZL2020207103546, i.e. the stepped generatrix described in the present application.

[0046] The axial plane in the present application refers to a plane containing the thread axis, i.e. a cross section containing the thread axis, and the conventional thread and the stepped thread both have their respective axial planes.

[0047] Figure 2 is a structural schematic diagram of a tolerance band of a stepped external thread provided by an embodiment of the present application.

[0048] In actual production, the actual size of the stepped thread may have a machining error, and the allowable machining error range of the stepped external thread (i.e. the tolerance band of the stepped external thread) is as shown in Figure 2 Specifically, the actually machined stepped external thread should be between its maximum solid tooth profile and minimum solid tooth profile. The minimum solid tooth profile is the tooth profile when the solid part is the smallest during the machining process when the machined object is the stepped external thread, i.e. the cut part is relatively more during machining. The maximum solid tooth profile is the tooth profile when the solid part is the largest during the machining process when the machined object is the stepped external thread, i.e. the cut part is relatively less during machining. Both the maximum solid tooth profile and the minimum solid tooth profile include the six-segment tooth profile lines of the stepped external thread, which are the first tooth flank profile line 21-1, the second tooth flank profile line 22-1, the third tooth flank profile line 23-1, the fourth tooth crest profile line 24-1, the fifth tooth flank profile line 25-1 and the sixth tooth bottom profile line 26-1 of the minimum solid tooth profile; and the first tooth flank profile line 21-2, the second tooth flank profile line 22-2, the third tooth flank profile line 23-2, the fourth tooth crest profile line 24-2, the fifth tooth flank profile line 25-2 and the sixth tooth bottom profile line 26-2 of the maximum solid tooth profile.

[0049] In actual production, the stepped external thread product processed needs to be measured to confirm whether the actual processing size falls within the allowed tolerance range, and only then can it be considered as a qualified product. If the actual processing size does not fall within the allowed tolerance range, the processing parameters of the machine tool need to be optimized according to the measurement results until the actual processing size falls within the allowed tolerance range. Since the stepped external thread structure is complex, the measurement is difficult, and the traditional thread measurement method cannot complete the fast and accurate measurement of the stepped external thread.

[0050] Figure 3 is a cross-sectional view of a through-end ring gauge passing through the thread axis.

[0051] Figure 4 is a cross-sectional view of a through-end ring gauge passing through the thread axis.

[0052] The embodiment of the present application provides a stepped external thread measuring tool, which is a combined measuring tool, comprising a through-end ring gauge TH and a dead-end ring gauge ZH. Wherein, referring to Figure 3 , the through-end ring gauge TH comprises two thread segments, namely a thread segment TH1 and a thread segment TH2. Referring to Figure 4 , the dead-end ring gauge ZH comprises three thread segments, namely a thread segment ZH1, a thread segment ZH2 and a thread segment ZH3. Specifically, the thread segment TH1, the thread segment TH2, the thread segment ZH1, the thread segment ZH2 and the thread segment ZH3 are all internal threads.

[0053] When the two thread segments of the through-end ring gauge TH can be screwed into the measured stepped external thread respectively, and the three thread segments of the dead-end ring gauge ZH cannot be screwed into the measured stepped external thread, it can be determined that the actual size of the measured stepped external thread is within the allowed tolerance range; when any one of the thread segments of the through-end ring gauge TH cannot be screwed into the measured stepped external thread, or any one of the thread segments of the dead-end ring gauge ZH can be screwed into the measured stepped external thread, it can be determined that the actual size of the measured stepped external thread is not within the allowed tolerance range.

[0054] It is worth noting that, as shown in Figure 3 , the through-end ring gauge TH can comprise a through-end main body, and the thread segment TH1 and the thread segment TH2 can be symmetrically arranged at two ends of the through-end main body. In other specific implementation manners, the thread segment TH1 and the thread segment TH2 can also be arranged on the through-end main body in other forms, for example, in the form of an included angle. The included angle can be any angle, for example, 30°, 60° or 90°.

[0055] Similarly, as shown in Figure 4The shown end ring gauge ZH can include an end body, thread segments ZH1, ZH2 and ZH3 arranged in a form that the included angle between the thread axes of any two thread segments is 120°, and in other specific implementations, the thread segments ZH1, ZH2 and ZH3 can also be arranged on the end body in other forms. For example, the included angle between the thread segments ZH1 and ZH2, and the included angle between the thread segments ZH2 and ZH3 are both in a form of 90°.

[0056] Figure 5 is a design tooth profile structure schematic diagram of a thread segment TH1 provided by an embodiment of the present application. Wherein, Figure 5 The thread axis L1 of the measured external thread and the thread axis of the thread segment TH1 coincide.

[0057] Referring to Figure 5 , the profile line of the design tooth profile of the thread segment TH1 of the through end ring gauge TH includes tooth flank profile line TH1-1, tooth flank profile line TH1-2, tooth flank profile line TH1-4 and tooth root profile line TH1-5, and in the case where the thread axis L1 of the measured external thread and the thread axis of the thread segment TH1 coincide: the tooth flank profile line TH1-1 can completely contain the third tooth flank profile line 23-2 of the maximum solid tooth profile of the measured external thread, and at the same time the tooth flank profile line TH1-2 completely contains the second tooth flank profile line 22-2 of the maximum solid tooth profile of the measured external thread, and at the same time the tooth flank profile line TH1-4 partially coincides with the fifth tooth flank profile line 25-2 of the maximum solid tooth profile of the measured external thread, and at the same time the tooth root profile line TH1-5 has a first preset distance with the fourth tooth top profile line 24-2 of the maximum solid tooth profile of the measured external thread, that is, the tooth root profile line TH1-5 is outside the tolerance band of the measured external thread.

[0058] Optionally, the profile line of the design tooth profile of the thread segment TH1 of the through end ring gauge TH further includes a tooth top profile line TH1-3, the tooth top profile line TH1-3 is connected between the tooth flank profile line TH1-2 and the tooth flank profile line TH1-4, and the tooth top profile line TH1-3 is outside the tolerance band of the measured external thread.

[0059] Optionally, the tooth flank profile line TH1-1, the tooth flank profile line TH1-2, the tooth top profile line TH1-3, the tooth flank profile line TH1-4 and the tooth root profile line TH1-5 are sequentially connected.

[0060] Figure 6 is a design tooth profile structure schematic diagram of a thread segment TH2 provided by an embodiment of the present application. Wherein, Figure 6 The thread axis L1 of the measured external thread and the thread axis of the thread segment TH2 coincide.

[0061] Referring toFigure 6 The design profile of the thread segment TH2 of the go end ring gauge TH includes the flank profile TH2-1, the flank profile TH2-3, the crest profile TH2-2, and the root profile TH2-4. When the thread axis L1 of the measured stepped external thread and the thread axis of the thread segment TH2 coincide: the flank profile TH2-1 can completely contain the first flank profile 21-2 of the maximum material profile of the measured stepped external thread, and at the same time, the flank profile TH2-3 completely contains the fifth flank profile 25-2 of the maximum material profile of the measured stepped external thread, and at the same time, the crest profile TH2-2 is outside the tolerance zone of the measured stepped external thread, and at the same time, the root profile TH2-4 has a second preset distance from the fourth crest profile 24-2 of the maximum material profile of the measured stepped external thread. That is to say, the root profile TH2-4 is outside the tolerance zone of the measured stepped external thread.

[0062] Optionally, the lateral profile TH2-1, the crest profile TH2-2, the lateral profile TH2-3, and the floor profile TH2-4 are connected sequentially.

[0063] Specifically, the thread section TH1 of the go end ring gauge TH is based on the fifth flank profile 25 of the measured stepped external thread, and measures the positions of the third flank profile 23 and the second flank profile 22. If they conform to... Figure 5 If the thread segment TH1, which meets the design tooth profile requirements, can be screwed into the measured stepped external thread, it indicates that the third flank profile 23, the second flank profile 22, and the fifth flank profile 25 of the measured stepped external thread do not exceed the tolerance zone from the side of the maximum material tooth profile of the stepped external thread; conversely, if it meets the requirements... Figure 5 If the thread segment TH1, which meets the design tooth profile requirements, cannot be screwed into the measured stepped external thread, it means that the third tooth profile 23, the second tooth profile 22, or the fifth tooth profile 25 of the measured stepped external thread exceeds the tolerance zone from the side of the maximum material tooth profile of the stepped external thread, i.e., the product is unqualified.

[0064] The thread section TH2 of the go end ring gauge TH is based on the fifth flank profile 25 of the stepped external thread being measured, and the position of the first flank profile 21 is measured. If it conforms to... Figure 6 If the thread segment TH2, which meets the design tooth profile requirements, can be screwed into the measured stepped external thread, it indicates that neither the first flank profile 21 nor the fifth flank profile 25 of the measured stepped external thread exceeds the tolerance zone from the side of the maximum material tooth profile of the stepped external thread; conversely, if it meets the requirements... Figure 6 If the thread segment TH2, which meets the design tooth profile requirements, cannot be screwed into the measured stepped external thread, it means that the first tooth profile 21 or the fifth tooth profile 25 of the measured stepped external thread exceeds the tolerance zone from the side of the maximum material tooth profile of the stepped external thread, i.e., the product is unqualified.

[0065] It should be noted that the two threaded segments TH1 and TH2 are used to measure different flank profiles on the through-end ring gauge TH, instead of measuring all flanks at the same time by an internal thread segment that is completely consistent with the maximum basic profile of the external stepped thread, in order to facilitate the machining of the through-end ring gauge TH. In order to ensure long-term use of the ring gauge, the ring gauge is usually made of very hard material, and thus needs to be machined by grinding process. It is difficult to machine an internal thread segment that is completely consistent with the maximum basic profile of the external stepped thread by grinding process. The through-end ring gauge TH provided in the present application can achieve the measurement effect and facilitate the machining and manufacturing of the through-end ring gauge TH.

[0066] Figure 7 is a schematic diagram of a design profile structure of a threaded segment ZH1 provided in an embodiment of the present application. Wherein, Figure 7 the thread axis L1 of the measured external stepped thread coincides with the thread axis of the threaded segment ZH1.

[0067] Referring to Figure 7 , the design profile of the threaded segment ZH1 of the end ring gauge ZH includes a flank profile ZH1-1, a flank profile ZH1-3, a crest profile ZH1-2, and a root profile ZH1-4. In the case where the thread axis L1 of the measured external stepped thread coincides with the thread axis of the threaded segment ZH1: the flank profile ZH1-1 can partially coincide with the third flank profile 23-1 of the minimum basic profile of the measured external stepped thread, and at the same time, the flank profile ZH1-3 partially coincides with the fifth flank profile 25-1 of the minimum basic profile of the measured external stepped thread, and at the same time, the crest profile ZH1-2 does not intersect the second flank profile 22-1 of the minimum basic profile of the measured external stepped thread, and at the same time, the crest profile ZH1-2 also does not intersect the second flank profile 22-2 of the maximum basic profile of the measured external stepped thread, and at the same time, the root profile ZH1-4 has a third preset distance from the fourth crest profile 24-2 of the maximum basic profile of the measured external stepped thread, that is, the root profile ZH1-4 is outside the tolerance band of the measured external stepped thread.

[0068] Optionally, the flank profile ZH1-1, the crest profile ZH1-2, the flank profile ZH1-3, and the root profile ZH1-4 are sequentially connected.

[0069] Figure 8 is a schematic diagram of a design profile structure of a threaded segment ZH2 provided in an embodiment of the present application. Wherein, Figure 8 the thread axis L1 of the measured external stepped thread coincides with the thread axis of the threaded segment ZH2.

[0070] Referring to Figure 8In the case that the thread axis L1 of the measured external stepped thread coincides with the thread axis of the thread segment ZH2, the tooth flank profile ZH2-2 can partially coincide with the second tooth flank profile 22-1 of the minimum solid profile of the measured external stepped thread, and at the same time the tooth flank profile ZH2-4 partially coincides with the fifth tooth flank profile 25-1 of the minimum solid profile of the measured external stepped thread, and at the same time the tooth flank profile ZH2-1 is at a distance D1 in the thread axis direction from the third tooth flank profile 23-2 of the maximum solid profile of the measured external stepped thread, which is greater than the width D2 of the tolerance band of the measured external stepped thread in the thread axis direction, and at the same time the tooth root profile ZH2-5 is at a fourth preset distance from the fourth tooth crest profile 24-2 of the maximum solid profile of the measured external stepped thread, that is, the tooth root profile ZH2-5 is outside the tolerance band of the measured external stepped thread.

[0071] Optionally, the profile line of the design tooth profile of the thread segment ZH2 of the end ring gauge ZH further comprises a tooth crest profile ZH2-3, which is connected between the tooth flank profile ZH2-2 and the tooth flank profile ZH2-4.

[0072] Optionally, the tooth flank profile ZH2-1, the tooth flank profile ZH2-2, the tooth crest profile ZH2-3, the tooth flank profile ZH2-4 and the tooth root profile ZH2-5 are sequentially connected.

[0073] Figure 9 is a schematic diagram of a design tooth profile structure of a thread segment ZH3 provided by an embodiment of the present application. Wherein, Figure 9 The thread axis L1 of the measured external stepped thread coincides with the thread axis of the thread segment ZH3.

[0074] Referring to Figure 9The thread profile of the thread segment ZH3 of the stop ring gauge ZH includes the flank profile ZH3-1, flank profile ZH3-3, crest profile ZH3-2, and root profile ZH3-4. When the thread axis L1 of the measured stepped external thread coincides with the thread axis of the thread segment ZH3: the flank profile ZH3-1 completely encompasses the first flank profile 21-1 of the minimum material profile of the measured stepped external thread; simultaneously, the flank profile ZH3-3 completely encompasses the fifth flank profile 25-1 of the minimum material profile of the measured stepped external thread; and simultaneously, the root profile ZH3-4 has a fifth preset distance from the fourth crest profile 24-2 of the maximum material profile of the measured stepped external thread. In other words, the root profile ZH3-4 is outside the tolerance zone of the measured stepped external thread. The first, second, third, fourth, and fifth preset distances can be the same or different.

[0075] Optionally, the tooth lateral contour line ZH3-1, tooth crest contour line ZH3-2, tooth lateral contour line ZH3-3, and tooth floor contour line ZH3-4 are connected sequentially.

[0076] Specifically, the thread segment ZH1 of the stop ring gauge ZH is based on the fifth tooth flank profile 25 of the measured stepped external thread, and the position of the third tooth flank profile 23 is measured. If it conforms to... Figure 7 If the thread segment ZH1, which meets the design tooth profile requirements, cannot be screwed into the measured stepped external thread, it indicates that the third flank profile 23 and the fifth flank profile 25 of the measured stepped external thread do not exceed the tolerance zone from the minimum material tooth profile side of the stepped external thread; conversely, if it meets the requirements... Figure 7 If the thread segment ZH1, which meets the design tooth profile requirements, can be screwed into the measured stepped external thread, it means that the third tooth profile 23 or the fifth tooth profile 25 of the measured stepped external thread exceeds the tolerance zone from the side of the minimum material tooth profile of the stepped external thread, i.e., the product is unqualified.

[0077] The thread section ZH2 of the stop ring gauge ZH is based on the fifth tooth flank profile 25 of the measured stepped external thread. The position of the second tooth flank profile 22 is measured. If it conforms to... Figure 8 If the thread segment ZH2, which meets the design tooth profile requirements, cannot be screwed into the measured stepped external thread, it indicates that neither the second flank profile 22 nor the fifth flank profile 25 of the measured stepped external thread extends beyond the tolerance zone from the minimum material tooth profile side of the stepped external thread; conversely, if it meets the requirements... Figure 8 If the thread segment ZH2, which meets the design tooth profile requirements, can be screwed into the measured stepped external thread, it means that the second tooth flank profile 22 or the fifth tooth flank profile 25 of the measured stepped external thread exceeds the tolerance zone from the side of the minimum material tooth profile of the stepped external thread, i.e., the product is unqualified.

[0078] The thread segment ZH3 of the end ring gauge ZH is measured based on the fifth flank profile line 25 of the measured external thread, and the position of the first flank profile line 21 is measured. If the thread segment ZH3 of the design tooth profile requirement can be screwed into the measured external thread, it indicates that the first flank profile line 21 and the fifth flank profile line 25 of the measured external thread are both not out of the tolerance band range from the side of the minimum solid tooth profile of the external thread. Figure 9 If the thread segment ZH3 of the design tooth profile requirement can be screwed into the measured external thread, it indicates that the first flank profile line 21 or the fifth flank profile line 25 of the measured external thread is out of the tolerance band range from the side of the minimum solid tooth profile of the external thread, that is, the product is unqualified. Figure 9 If the thread segment ZH3 of the design tooth profile requirement can be screwed into the measured external thread, it indicates that the first flank profile line 21 or the fifth flank profile line 25 of the measured external thread is out of the tolerance band range from the side of the minimum solid tooth profile of the external thread, that is, the product is unqualified.

[0079] It should be noted that the three thread segments ZH1, ZH2 and ZH3 are used to measure different flank profile lines on the end ring gauge ZH, instead of using an internal thread segment that is completely consistent with the minimum solid tooth profile of the external thread to measure all flanks at the same time, in order to facilitate the machining of the end ring gauge ZH. In order to ensure the long-term use of the ring gauge, the ring gauge is usually made of very hard material, so it needs to be processed by grinding process. It is difficult to process an internal thread segment that is completely consistent with the minimum solid tooth profile of the external thread by grinding process. The end ring gauge ZH scheme provided by the present application can not only achieve the measurement effect, but also facilitate the machining and manufacturing of the end ring gauge ZH.

[0080] In addition, the end ring gauge ZH and the end ring gauge ZH provided by the present application do not measure the fourth crest profile line 24 and the sixth root profile line 26 of the external thread, because the measurement of the actual accuracy of these two profile lines can be realized by other conventional technologies, and is not the problem to be solved by the present application.

[0081] The external thread measuring tool provided by the embodiment of the present application can detect different tooth profile lines of the measured external thread by combining the gauge, without the participation of auxiliary equipment, and the measurement process is simple, which can not only improve the measurement efficiency but also effectively reduce the measurement cost. Moreover, the external thread measuring tool is designed in the form of a combined gauge, which can effectively ensure the service life.

[0082] Corresponding to the foregoing embodiment of the external thread measuring tool, the present application also provides an embodiment of an external thread measuring method. The measuring method adopts the measuring tool provided by the foregoing embodiment.

[0083] Figure 10 is a flowchart of an external thread measuring method provided by the embodiment of the present application.

[0084] Referring to Figure 10 , the measuring method can be realized by the following steps S1 to S3.

[0085] S1: screw the through-end ring gauge and the end-stop ring gauge with the external stepped thread respectively.

[0086] In step S1, the through-end ring gauge TH includes two threaded segments TH1 and TH2, and the end-stop ring gauge ZH includes three threaded segments ZH1, ZH2 and ZH3. The threaded segments TH1, TH2, ZH1, ZH2 and ZH3 are all internal threads, and the threaded segments TH1, TH2, ZH1, ZH2 and ZH3 can be screwed with the measured external stepped thread in any order.

[0087] S2: when both threaded segments of the through-end ring gauge can be screwed into the measured external stepped thread, and all three threaded segments of the end-stop ring gauge cannot be screwed into the measured external stepped thread, it can be determined that the actual size of the external stepped thread is within the allowed tolerance range.

[0088] In step S2, when both threaded segments TH1 and TH2 can be screwed into the measured external stepped thread, and all threaded segments ZH1, ZH2 and ZH3 cannot be screwed into the measured external stepped thread, the measured external stepped thread meets the design requirements, and the product is qualified.

[0089] S3: when any threaded segment of the through-end ring gauge cannot be screwed into the measured external stepped thread, or any threaded segment of the end-stop ring gauge can be screwed into the measured external stepped thread, it can be determined that the actual size of the external stepped thread is not within the allowed tolerance range.

[0090] In step S3, when both threaded segments TH1 and TH2 cannot be screwed into the measured external stepped thread, and any one of the threaded segments ZH1, ZH2 and ZH3 can be screwed into the measured external stepped thread, the measured external stepped thread does not meet the design requirements, and the product is unqualified.

[0091] In the above measurement method, the geometric characteristics of the through-end ring gauge and the end-stop ring gauge meet the description of the stepped thread measurement tool in the foregoing embodiments, which will not be repeated here.

[0092] By the above method, it can be determined whether the size of the measured external stepped thread is qualified conveniently and quickly, which has the advantages of high measurement accuracy and high efficiency, and the measurement method is simple, easy to operate, and does not require any auxiliary equipment, effectively reducing the measurement cost.

[0093] It is understood that other embodiments of the application will become readily apparent to those skilled in the art from the disclosure herein, namely, from the description, claims, and drawings. The application is intended to embrace all such alterations, modifications, and variations that fall within the scope of the application, along with all of its general or specific statements where in the knowledge and predilections of one of ordinary skill in the art are factors to be considered.

[0094] It is to be understood that the application is not limited to particular details described herein and / or illustrated in the drawings. Rather, the application can be practiced with other embodiments that are apparent to, or readily ascertained by, those of ordinary skill in the art, given the disclosure herein, namely, the best mode for carrying out the application. The true scope of the application is, therefore, indicated by the appended claims.

Claims

1. A pin thread measuring tool for measuring a pin thread, the pin thread having a profile comprising, in order, a first flank profile, a second flank profile, a third flank profile, a fourth crest profile, a fifth flank profile and a sixth root profile; wherein, The first tooth flank profile line, the second tooth flank profile line and the third tooth flank profile line are sequentially connected to form a stepped generatrix; characterized in that the stepped external thread measuring tool comprises a through-end ring gauge TH and a dead-end ring gauge ZH; The through-end ring gauge TH comprises a threaded segment TH1 and a threaded segment TH2; wherein the threaded segment TH1 is used to judge whether the second tooth flank profile line, the third tooth flank profile line and the fifth tooth flank profile line of the tooth profile line of the stepped external thread exceed the tolerance band range from the side of the maximum solid tooth profile of the stepped external thread; and the threaded segment TH2 is used to judge whether the first tooth flank profile line and the fifth tooth flank profile line of the tooth profile line of the stepped external thread exceed the tolerance band range from the side of the maximum solid tooth profile of the stepped external thread; The dead-end ring gauge ZH comprises a threaded segment ZH1, a threaded segment ZH2 and a threaded segment ZH3; wherein the threaded segment ZH1 is used to judge whether the third tooth flank profile line and the fifth tooth flank profile line of the tooth profile line of the stepped external thread exceed the tolerance band range from the side of the minimum solid tooth profile of the stepped external thread; the threaded segment ZH2 is used to judge whether the second tooth flank profile line and the fifth tooth flank profile line of the tooth profile line of the stepped external thread exceed the tolerance band range from the side of the minimum solid tooth profile of the stepped external thread; and the threaded segment ZH3 is used to judge whether the first tooth flank profile line and the fifth tooth flank profile line of the tooth profile line of the stepped external thread exceed the tolerance band range from the side of the minimum solid tooth profile of the stepped external thread.

2. The external thread measuring tool of claim 1 wherein, The profile line of the design tooth profile of the threaded segment TH1 comprises a tooth flank profile line TH1-1, a tooth flank profile line TH1-2, a tooth flank profile line TH1-4 and a tooth bottom profile line TH1-5; wherein, in the case that the threaded axis of the threaded segment TH1 coincides with the stepped external thread, the tooth flank profile line TH1-1 can completely contain the third tooth flank profile line of the maximum solid tooth profile of the stepped external thread, and at the same time, the tooth flank profile line TH1-2 completely contains the second tooth flank profile line of the maximum solid tooth profile of the stepped external thread, and at the same time, the tooth flank profile line TH1-4 partially coincides with the fifth tooth flank profile line of the maximum solid tooth profile of the stepped external thread, and at the same time, the tooth bottom profile line TH1-5 has a first preset distance from the fourth tooth top profile line of the maximum solid tooth profile of the stepped external thread.

3. The stepped external thread measuring tool according to claim 2, characterized in that The profile line of the design tooth profile of the threaded segment TH1 further comprises a tooth top profile line TH1-3, which is connected between the tooth flank profile line TH1-2 and the tooth flank profile line TH1-4, and the tooth top profile line TH1-3 is outside the tolerance band of the stepped external thread.

4. The stepped external thread measuring tool according to claim 1, characterized in that The profile line of the design tooth shape of the thread segment TH2 includes a flank profile line TH2-1, a flank profile line TH2-3, a crest profile line TH2-2 and a root profile line TH2-4; wherein, in the case that the thread axis of the stepped external thread and the thread segment TH2 coincide: the flank profile line TH2-1 can completely contain the first flank profile line of the maximum solid tooth shape of the stepped external thread, and at the same time the flank profile line TH2-3 completely contains the fifth flank profile line of the maximum solid tooth shape of the stepped external thread, and at the same time the crest profile line TH2-2 is outside the tolerance band of the stepped external thread, and at the same time the root profile line TH2-4 has a second preset distance from the fourth crest profile line of the maximum solid tooth shape of the stepped external thread.

5. The stepped external thread measuring tool according to claim 1, wherein, The profile line of the design tooth shape of the thread segment ZH1 includes a flank profile line ZH1-1, a flank profile line ZH1-3, a crest profile line ZH1-2 and a root profile line ZH1-4; wherein, in the case that the thread axis of the stepped external thread and the thread segment ZH1 coincide: the flank profile line ZH1-1 can partially coincide with the third flank profile line of the minimum solid tooth shape of the stepped external thread, and at the same time the flank profile line ZH1-3 partially coincides with the fifth flank profile line of the minimum solid tooth shape of the stepped external thread, and at the same time the crest profile line ZH1-2 does not intersect the second flank profile line of the minimum solid tooth shape of the stepped external thread, and at the same time the crest profile line ZH1-2 also does not intersect the second flank profile line of the maximum solid tooth shape of the stepped external thread, and at the same time the root profile line ZH1-4 has a third preset distance from the fourth crest profile line of the maximum solid tooth shape of the stepped external thread.

6. The stepped external thread measuring tool according to claim 1, wherein, The profile line of the design tooth shape of the thread segment ZH2 includes a flank profile line ZH2-1, a flank profile line ZH2-2, a flank profile line ZH2-4 and a root profile line ZH2-5; wherein, in the case that the thread axis of the stepped external thread and the thread segment ZH2 coincide: the flank profile line ZH2-2 can partially coincide with the second flank profile line of the minimum solid tooth shape of the stepped external thread, and at the same time the flank profile line ZH2-4 partially coincides with the fifth flank profile line of the minimum solid tooth shape of the stepped external thread, and at the same time the distance between the flank profile line ZH2-1 and the third flank profile line of the maximum solid tooth shape of the stepped external thread in the direction of the thread axis is greater than the width of the tolerance band of the stepped external thread in the direction of the thread axis, and at the same time the root profile line ZH2-5 has a fourth preset distance from the fourth crest profile line of the maximum solid tooth shape of the stepped external thread.

7. The stepped external thread measuring tool according to claim 6, wherein, The profile line of the design tooth shape of the thread segment ZH2 further comprises a crest profile line ZH2-3, which is connected between the flank profile line ZH2-2 and the flank profile line ZH2-4.

8. The premium thread measuring tool according to claim 1, wherein, The profile line of the design tooth shape of the thread segment ZH3 comprises a flank profile line ZH3-1, a flank profile line ZH3-3, a crest profile line ZH3-2 and a root profile line ZH3-4; wherein, in the case that the thread axis of the premium thread and the thread segment ZH3 coincide: the flank profile line ZH3-1 can completely contain the first flank profile line of the minimum solid tooth shape of the premium thread, and at the same time the flank profile line ZH3-3 completely contains the fifth flank profile line of the minimum solid tooth shape of the premium thread, and at the same time the root profile line ZH3-4 has a fifth preset distance with the fourth crest profile line of the maximum solid tooth shape of the premium thread.

9. A method of measuring a premium external thread, characterized in that The premium thread measuring method is applied to the premium thread measuring tool according to any one of claims 1-8, and is used for measuring the premium thread, and the premium thread measuring method comprises: The through end ring gauge and the end ring gauge are respectively screwed with the premium thread; When the two thread segments of the through end ring gauge can be screwed into the premium thread respectively, and the three thread segments of the end ring gauge cannot be screwed into the premium thread, it can be determined that the actual size of the premium thread is within the allowable tolerance range.

10. The pin thread measurement method of claim 9 wherein, The premium thread measuring method further comprises: When any one thread segment of the through end ring gauge cannot be screwed into the premium thread, or any one thread segment of the end ring gauge can be screwed into the premium thread, it can be determined that the actual size of the premium thread is not within the allowable tolerance range.

Images