A measuring device and method for measuring the minor diameter of a spiral internal spline

Abstract

The present invention relates to a measuring device and a measuring method for the minor diameter of a spiral internal spline, comprising an inner diameter indicator, a dial indicator is arranged at one end of a connecting rod of the inner diameter indicator, and a movable measuring head is arranged at the other end, the movable measuring head is perpendicular to the axial direction of the connecting rod, a positioning measuring head is installed at the tail end of the movable measuring head, the central axis of the positioning measuring head and the central axis of the movable measuring head are the same axis, the extended end of the positioning measuring head is a measuring positioning part, a tooth top positioning part is arranged in the middle of the measuring positioning part, the tooth top positioning part abuts against the tooth top of the measured spiral internal spline, keyway positioning parts are symmetrically arranged on both sides of the tooth top positioning part, the keyway positioning part is used to be inserted into the keyway of the measured spiral internal spline, by adopting the measuring device, the technician only needs to judge whether the sum of the reading of the dial indicator and the minor diameter value of the spiral internal spline of the proofreading sample circle is within the size range, so as to know whether the size of the spiral internal spline of the measured part is qualified, the operation is simple, and the measurement accuracy is high.

Description

Technical Field

[0001] The invention relates to the technical field of measuring the minor diameter of an internal spline, and in particular to a measuring device and a measuring method for the minor diameter of a spiral internal spline. Background Art

[0002] Parts with internal helical splines are often needed in some special machinery, and the minor diameter of the internal helical splines must be controlled within the specified maximum and minimum sizes. However, since the internal helical splines are not straight teeth and have a helix angle, when tested with a standard internal diameter indicator, the probe can easily slip from the tooth top to the keyway of the internal spline, and can only measure the minor diameter of the end face of the internal spline, and cannot measure the minor diameter of other positions along the length direction of the internal helical spline, which can easily cause a large error in the size of the internal helical spline, making the part unusable. Summary of the invention

[0003] The purpose of the present invention is to provide a measuring device and method for the minor diameter of a spiral internal spline in view of the deficiencies in the prior art, which can accurately measure the actual size of the minor diameter of the spiral internal spline of the measured part and can quickly determine whether the minor diameter size of the spiral internal spline is qualified. Moreover, the device and method are simple to assemble and easy to operate.

[0004] The technical solution of the present invention is: a device for measuring the minor diameter of a spiral internal spline, comprising an inner diameter indicator, a dial indicator is arranged at one end of a connecting rod of the inner diameter indicator, and a movable measuring head is arranged at the other end, the movable measuring head is perpendicular to the axial direction of the connecting rod, a positioning measuring head is installed at the tail end of the movable measuring head, the central axis of the positioning measuring head and the central axis of the movable measuring head are the same axis, the extended end of the positioning measuring head is a measuring positioning part, a tooth top positioning part is arranged in the middle of the measuring positioning part, the tooth top positioning part abuts against the tooth top of the measured spiral internal spline, keyway positioning parts are symmetrically arranged on both sides of the tooth top positioning part, the keyway positioning part is used to be inserted into the keyway of the measured spiral internal spline.

[0005] The arc radius R1 of the keyway positioning portion is 0.1 to 0.2 mm smaller than half of the minimum value of the major diameter D1 of the spiral internal spline being measured.

[0006] The width L1 of the keyway positioning portion is 0.1-0.2 mm smaller than half of the minimum value of the keyway width L0 of the measured spiral internal spline, and the curvature of the facing sides of the two keyway positioning portions is consistent with the curvature of the tooth root of the measured spiral internal spline.

[0007] The arc radius R2 of the tooth top positioning portion is 3 to 5 mm smaller than half of the minimum value of the measured spiral internal spline minor diameter D2.

[0008] The tail end of the movable measuring head is provided with a threaded hole, the upper end of the positioning measuring head is a mounting portion provided with an external thread, and the positioning measuring head is threadedly connected with the movable measuring head through the mounting portion.

[0009] The total length of the measuring and positioning portion is greater than the diameter of the positioning and measuring head, and the width of the measuring and positioning portion is less than the diameter of the positioning and measuring head.

[0010] The distance between the vertex of the tooth top positioning portion and the center of the measured spiral internal spline is smaller than the distance between the vertex of the keyway positioning portion and the center of the measured spiral internal spline, and the distance between the vertex of the tooth top positioning portion and the center of the measured spiral internal spline is half of the minor diameter D2 of the measured spiral internal spline.

[0011] A method for measuring the minor diameter of a spiral internal spline comprises the following steps:

[0012] 1) Thread the measuring and positioning part of the positioning measuring head into the movable measuring head of the inner diameter indicator;

[0013] 2) Insert one end of the inner diameter indicator with the measuring head into the spiral internal spline of a calibration sample circle, so that the tooth top positioning part and the top of the movable measuring head respectively press against the two opposite tooth tops, and the two keyway positioning parts are respectively inserted into the keyways for positioning;

[0014] 3) Adjust the dial indicator of the inner diameter indicator to zero;

[0015] 4) Take out the calibrated inner diameter indicator from the calibration sample circle and insert it into the spiral internal spline of the measured part, so that the tooth top positioning part and the top of the movable measuring head respectively press against the two opposite tooth tops, and the two keyway positioning parts are respectively inserted into the keyway for positioning;

[0016] 5) Move the inner diameter indicator along the spiral direction of the spiral internal spline to the position where measurement is required, and record the reading of the dial indicator;

[0017] 6) Add the reading of the dial indicator in step 5) to the minor diameter value of the spiral internal spline of the calibration sample circle, which is the minor diameter value of the spiral internal spline of the tested part;

[0018] 6-1) If the sum of the dial indicator reading and the minor diameter of the spiral internal spline of the calibration sample ring is within the size range, the size of the tested part is qualified;

[0019] 6-2) If the sum of the dial indicator reading and the minor diameter of the spiral internal spline of the calibration sample ring is not within the size range, the size of the measured part is unqualified.

[0020] The above technical solution is adopted: the tail end of the movable measuring head is installed with a positioning measuring head, and the positioning measuring head is used to replace the standard replaceable measuring head of the inner diameter indicator, and the positioning measuring head and the movable measuring head are placed on the same central axis to ensure the measurement accuracy. A tooth top positioning part is provided in the middle of the measuring positioning part, and keyway positioning parts are symmetrically provided on both sides of the tooth top positioning part. When in use, the end of the inner diameter indicator provided with the measuring head is inserted into the spiral internal spline of the measured part, so that the tooth top positioning part of the positioning measuring head and the top of the movable measuring head are respectively against two opposite tooth tops, and the two keyway positioning parts are respectively inserted into the keyway for positioning, and then the inner diameter indicator is moved to the position to be measured along the spiral direction of the spiral internal spline to perform measurement. In the process of moving the inner diameter indicator for measurement, the positioning measuring head always maintains three-point positioning in the spiral internal spline through the tooth top positioning part and the two keyway positioning parts, and no deviation occurs, so as to prevent the tooth top positioning part from slipping from the tooth top to the keyway, thereby ensuring the measurement accuracy. Moreover, the two keyway positioning parts are respectively inserted into the keyways to guide the moving inner diameter indicator, ensuring that the inner diameter indicator can move along the spiral direction of the spiral internal spline. The measuring device has a simple structure, high measurement accuracy, is easy for technicians to operate, and can greatly improve work efficiency.

[0021] The arc radius of the keyway positioning part is 0.1-0.2 mm smaller than half of the minimum major diameter of the spiral internal spline to be measured, so as to prevent the arc bottom end of the keyway positioning part from interfering with the keyway bottom of the spiral internal spline during measurement.

[0022] The width of the keyway positioning portion is 0.1 to 0.2 mm smaller than half of the minimum value of the keyway width of the measured spiral internal spline, and the curvature of the opposite sides of the two keyway positioning portions matches the curvature of the tooth root of the measured spiral internal spline, thereby preventing the side walls of the keyway positioning portions from interfering with the keyway groove walls of the spiral internal spline during measurement, and the arc-shaped side edges on the opposite sides of the two keyway positioning portions have a certain clamping force on the tooth root of the spiral internal spline, thereby further ensuring the accuracy of the measurement.

[0023] The arc radius of the tooth top positioning part is 3 to 5 mm smaller than half of the minimum minor diameter of the spiral internal spline to be measured, ensuring that the bottom end of the arc of the tooth top positioning part can contact the tooth top of the spiral internal spline while preventing the arc of the tooth top positioning part from interfering with the tooth top of the spiral internal spline during measurement.

[0024] A threaded hole is provided at the tail end of the movable measuring head, and the upper end of the positioning measuring head is a mounting portion provided with an external thread. The positioning measuring head is threadedly connected to the movable measuring head through the mounting portion. The threaded connection allows positioning measuring heads of different sizes to be replaced as needed, which has better applicability.

[0025] The distance between the vertex of the tooth top positioning portion and the center of the spiral internal spline to be measured is smaller than the distance between the vertex of the keyway positioning portion and the center of the spiral internal spline to be measured, and the distance between the vertex of the tooth top positioning portion and the center of the spiral internal spline to be measured is half of the minor diameter D2 of the spiral internal spline to be measured, further ensuring that the positioning measuring head can be accurately positioned on the tooth top and in the keyway.

[0026] The above-mentioned measuring method is adopted: the positioning measuring head of the present invention is used to replace the standard replaceable measuring head of the inner diameter indicator, and then the end of the inner diameter indicator installed with the measuring head is inserted into the spiral internal spline of the proofreading sample circle, so that the tooth top positioning part and the top end of the movable measuring head are respectively against the two opposite tooth tops, and the two keyway positioning parts are respectively inserted into the keyway for positioning, and then the dial indicator of the inner diameter indicator is adjusted to zero, that is, the pointer of the inner diameter indicator is calibrated to zero with the proofreading sample circle as the standard; then the inner diameter indicator is taken out, inserted into the spiral internal spline of the measured part, positioned by the measuring positioning part of the positioning measuring head, the inner diameter indicator is moved along the spiral direction of the spiral internal spline to the position to be measured, and the reading of the dial indicator is recorded; at this time, the sum of the reading of the dial indicator and the minor diameter value of the spiral internal spline of the proofreading sample circle is the measured minor diameter size of the measured part, and it is only necessary to judge whether the sum of the reading of the dial indicator and the minor diameter value of the spiral internal spline of the proofreading sample circle is within the size range to know whether the size of the measured part is qualified. The operation steps are very simple, and technicians can complete the measurement at the work site, which can not only improve measurement accuracy but also improve work efficiency.

[0027] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the present invention;

[0029] Figure 2 It is a structural schematic diagram of the positioning measuring head of the present invention;

[0030] Figure 3 is a cross-sectional view of a positioning measuring head of the present invention;

[0031] Figure 4 It is a schematic diagram of the structure of the tested spiral internal spline.

[0032] In the accompanying drawings, 1 is a positioning measuring head, 1-1 is a keyway positioning part, 1-2 is a tooth top positioning part, 2 is a spiral internal spline to be measured, 2-1 is a keyway, 2-2 is a tooth top, 3 is an inner diameter indicator, 3-1 is a dial indicator, 3-2 is a connecting rod, and 3-3 is a movable measuring head. DETAILED DESCRIPTION

[0033] See also Figures 1 to 4A device for measuring the minor diameter of a spiral internal spline comprises an inner diameter indicator 3, a dial indicator 3-1 is arranged at one end of a connecting rod 3-2 of the inner diameter indicator 3, and a movable measuring head 3-3 is arranged at the other end, and the movable measuring head 3-3 is axially perpendicular to the connecting rod 3-2. A positioning measuring head 1 is installed at the tail end of the movable measuring head 3-3, and the positioning measuring head 1 is used to replace the standard replaceable measuring head of the inner diameter indicator 3. A threaded hole is arranged at the tail end of the movable measuring head 3-3, and the upper end of the positioning measuring head 1 is a mounting part 1-3 with an external thread. The positioning measuring head 1 is threadedly connected to the movable measuring head 3-3 through the mounting part 1-3. By adopting the threaded connection, the positioning measuring head 1 of different sizes can be replaced as needed, and the applicability is better. The central axis of the positioning measuring head 1 is the same axis as the central axis of the movable measuring head 3-3, so that the positioning measuring head 1 is also axially perpendicular to the connecting rod 3-2, thereby ensuring the accuracy of the measurement. The extended end of the positioning measuring head 1 is a measuring positioning part, and a tooth top positioning part 1-2 is arranged in the middle of the measuring positioning part, and the tooth top positioning part 1-2 abuts against the tooth top 2-2 of the spiral internal spline 2 to be measured. Keyway positioning parts 1-1 are symmetrically arranged on both sides of the tooth top positioning part 1-2, and the keyway positioning part 1-1 is used to be inserted into the keyway 2-1 of the spiral internal spline 2 to be measured. The keyway positioning part 1-1 plays a positioning role when inserted into the keyway 2-1, and also plays a guiding role when the inner diameter indicator moves. The arc radius R1 of the keyway positioning part 1-1 is 0.1 to 0.2 mm smaller than half of the minimum value of the major diameter D1 of the spiral internal spline 2 to be measured, so as to prevent the arc bottom end of the keyway positioning part 1-1 from interfering with the keyway bottom of the spiral internal spline during measurement. The width L1 of the keyway positioning portion 1-1 is 0.1 to 0.2 mm smaller than half of the minimum value of the keyway width L0 of the measured spiral internal spline 2, and the curvature of the opposite sides of the two keyway positioning portions 1-1 is consistent with the curvature of the tooth root of the measured spiral internal spline 2, further ensuring the accuracy of the measurement and preventing the side wall of the keyway positioning portion 1-1 from interfering with the keyway groove wall of the spiral internal spline during measurement, and the arc-shaped side edges of the opposite sides of the two keyway positioning portions 1-1 have a certain clamping force on the tooth root of the spiral internal spline, thereby ensuring the reliability of positioning. The distance between the vertex of the tooth top positioning part 1-2 and the center O of the spiral internal spline 2 to be measured is less than the distance between the vertex of the keyway positioning part 1-1 and the center O of the spiral internal spline 2 to be measured, and the distance between the vertex of the tooth top positioning part 1-2 and the center O of the spiral internal spline 2 to be measured is half of the minor diameter D2 of the spiral internal spline 2 to be measured, so that the structure of the measuring positioning part and the spiral internal spline are complementary, ensuring that the measuring positioning part can be accurately positioned on the tooth top 2-2 of the spiral internal spline 2 to be measured and in the keyway 2-1. The arc radius R2 of the tooth top positioning part 1-2 is 3 to 5 mm smaller than half of the minimum value of the minor diameter D1 of the spiral internal spline 2 to be measured, so that the bottom end of the arc of the tooth top positioning part 1-2 can contact the tooth top of the spiral internal spline, ensuring the measurement accuracy while preventing the arc of the tooth top positioning part 1-2 from interfering with the tooth top of the spiral internal spline during measurement.The total length of the measuring and positioning part is greater than the diameter of the positioning and measuring head 1, and the width of the measuring and positioning part is less than the diameter of the positioning and measuring head 1, so as to ensure that the measuring and positioning part can be effectively positioned and leave space for the measuring and positioning part to move in the spiral internal spline. In the process of moving the inner diameter indicator 3 for measurement, the positioning and measuring head 1 always maintains three-point positioning in the spiral internal spline of the part through the tooth top positioning part 1-2 and the two keyway positioning parts 1-1, and there will be no deviation, so as to prevent the tooth top positioning part 1-2 from slipping from the tooth top to the keyway, thereby realizing the measurement of the minor diameter of the spiral internal spline and ensuring the accuracy of the measurement.

[0034] A method for measuring the minor diameter of a spiral internal spline comprises the following steps:

[0035] 1) Remove the standard replaceable measuring head on the inner diameter indicator gauge 3.

[0036] 2) Thread the measuring and positioning part of the positioning measuring head 1 and the movable measuring head 3-3 of the inner diameter indicator 3;

[0037] 2) Insert one end of the inner diameter indicator 3 with the measuring head installed into the spiral internal spline of the calibration sample ring, so that the tooth top positioning part 1-2 and the top of the movable measuring head 3-3 respectively press against the two opposite tooth tops, and the two keyway positioning parts 1-1 are respectively inserted into the keyways for positioning. The size of the spiral internal spline of the calibration sample ring is the same as the minimum size of the spiral internal spline of the measured part.

[0038] 3) Use the size of the calibration sample ring as the measurement reference for the size of the part being measured, and adjust the dial indicator 3-1 of the inner diameter indicator 3 to zero.

[0039] 4) Take out the calibrated inner diameter indicator 3 from the calibration sample circle and insert it into the spiral internal spline of the measured part, so that the tooth top positioning part 1-2 of the positioning measuring head 1 and the top of the movable measuring head 3-3 respectively rest against the two opposite tooth tops, and the two keyway positioning parts 1-1 are respectively inserted into the keyways for positioning.

[0040] 5) Guided by the two keyway positioning parts 1-1, move the inner diameter indicator 3 to the position to be measured along the spiral direction of the spiral internal spline, and record the reading of the dial indicator 3-1 at this time.

[0041] 6) Add the reading of dial gauge 3-1 in step 5) to the minor diameter value of the spiral internal spline of the calibration sample circle, which is the minor diameter value of the spiral internal spline of the tested part;

[0042] 6-1) If the sum of the reading of dial indicator 3-1 and the minor diameter of the spiral internal spline of the calibration sample ring is within the size range, the size of the tested part is qualified;

[0043] 6-2) If the sum of the reading of dial indicator 3-1 and the minor diameter of the spiral internal spline of the calibration sample ring is not within the size range, the size of the tested part is unqualified.

[0044] In the measurement process of the present invention, the tooth top positioning part 1-2 and the two keyway positioning parts 1-1 of the positioning measuring head 1 always maintain three-point positioning in the spiral internal spline, so when the inner diameter indicator 3 moves spirally, the tooth top positioning part 1-2 will not slide into the keyway, ensuring the accuracy of the measurement result, and the inner diameter indicator 3 moves spirally under the guidance of the keyway positioning part 1-1, which is convenient for technicians to measure different positions of the spiral internal spline, greatly improving work efficiency. The structure of the positioning measuring head is simple, and the factory can make positioning measuring heads of different sizes according to actual needs, so that the measuring device is suitable for spiral internal splines of different sizes. Moreover, the measuring method of the present invention is easy to operate. The technician only needs to judge whether the sum of the reading of the dial indicator and the minor diameter value of the spiral internal spline of the proofreading sample circle is within the size range, and then it can be known whether the size of the spiral internal spline of the measured part is qualified. The measuring device is easy to carry, and the operation steps are very simple. The technician can complete the measurement at the work site, which can improve the measurement accuracy and work efficiency.

Claims

1. A device for measuring the minor diameter of a spiral internal spline, comprising an inner diameter indicator (3), a dial indicator (3-1) being arranged at one end of a connecting rod (3-2) of the inner diameter indicator (3), and a movable measuring head (3-3) being arranged at the other end, the movable measuring head (3-3) being axially perpendicular to the connecting rod (3-2), characterized in that: A positioning measuring head (1) is installed at the tail end of the movable measuring head (3-3); the central axis of the positioning measuring head (1) is the same as the central axis of the movable measuring head (3-3); the extended end of the positioning measuring head (1) is a measuring positioning portion; a tooth top positioning portion (1-2) is provided in the middle of the measuring positioning portion; the tooth top positioning portion (1-2) abuts against the tooth top (2-2) of the spiral internal spline (2) to be measured; keyway positioning portions (1-1) are symmetrically provided on both sides of the tooth top positioning portion (1-2); the keyway positioning portion (1-1) is used to be inserted into the keyway (2-1) of the spiral internal spline (2) to be measured; The arc radius R1 of the keyway positioning portion (1-1) is 0.1 to 0.2 mm smaller than half of the minimum value of the major diameter D1 of the measured spiral internal spline (2); The width L1 of the keyway positioning portion (1-1) is 0.1 to 0.2 mm smaller than half of the minimum value of the keyway width L0 of the measured spiral internal spline (2), and the curvature of the facing sides of the two keyway positioning portions (1-1) matches the curvature of the tooth root of the measured spiral internal spline (2); The arc radius R2 of the tooth top positioning portion (1-2) is 3 to 5 mm smaller than half of the minimum value of the minor diameter D2 of the measured spiral internal spline (2); The total length of the measuring and positioning portion is greater than the diameter of the positioning and measuring head (1), and the width of the measuring and positioning portion is less than the diameter of the positioning and measuring head (1); The distance between the vertex of the tooth top positioning portion (1-2) and the center of the spiral internal spline (2) to be measured is smaller than the distance between the vertex of the keyway positioning portion (1-1) and the center of the spiral internal spline (2) to be measured, and the distance between the vertex of the tooth top positioning portion (1-2) and the center of the spiral internal spline (2) to be measured is half of the minor diameter D2 of the spiral internal spline (2) to be measured.

2. A device for measuring the minor diameter of a spiral internal spline according to claim 1, characterized in that: The rear end of the movable measuring head (3-3) is provided with a threaded hole, the upper end of the positioning measuring head (1) is a mounting portion (1-3) provided with an external thread, and the positioning measuring head (1) is threadedly connected to the movable measuring head (3-3) via the mounting portion (1-3).

3. The method for measuring the minor diameter of a spiral internal spline using the measuring device as claimed in claim 1 is characterized in that: The following steps are involved: 1) Thread the measuring and positioning part of the positioning measuring head and the movable measuring head of the inner diameter indicator; 2) Insert one end of the inner diameter indicator with the measuring head into the spiral internal spline of a calibration sample circle, so that the tooth top positioning part and the top of the movable measuring head respectively press against the two opposite tooth tops, and the two keyway positioning parts are respectively inserted into the keyways for positioning; 3) Adjust the dial indicator of the inner diameter indicator to zero; 4) Take out the calibrated inner diameter indicator from the calibration sample circle and insert it into the spiral internal spline of the measured part, so that the tooth top positioning part and the top of the movable measuring head respectively press against the two opposite tooth tops, and the two keyway positioning parts are respectively inserted into the keyway for positioning; 5) Move the inner diameter indicator along the spiral direction of the spiral internal spline to the position where measurement is required, and record the reading of the dial indicator; 6) Add the reading of the dial indicator in step 5) to the minor diameter value of the spiral internal spline of the calibration sample circle, which is the minor diameter value of the spiral internal spline of the tested part; 6-1) If the sum of the dial indicator reading and the minor diameter of the spiral internal spline of the calibration sample ring is within the size range, the size of the tested part is qualified; 6-2) If the sum of the dial indicator reading and the minor diameter of the spiral internal spline of the calibration sample ring is not within the size range, the size of the measured part is unqualified.

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