Float caliper for measuring the value of the spline M, method for measuring the value of the spline M

Abstract

The present application discloses a float caliper for measuring the M value of a spline, which comprises a main scale, a vernier scale matched with the main scale, a fixed jaw on the main scale, a movable jaw on the float scale matched with the fixed jaw, and a ball measuring rod matched with the spline and detachably mounted on the fixed jaw and the movable jaw. The float caliper further comprises an M value standard block with a standard M value of the spline to be measured. The main scale comprises a main body and a movable adjustable main scale mounted in the main body. The fixed jaw is integrally formed with the main body. The vernier scale is movable on the main body and matched with the adjustable main scale for measurement. The M value standard block is radially positioned by the ball measuring rod. The present application has higher precision and reliability, larger adjustable stroke, similar measurement operation to the common float caliper, lower requirement for the operator, higher universality and practicality, and improved measurement reliability of the M value of the taper spline. The present application further provides a method for measuring the M value of the spline.

Description

Technical Field

[0001] This invention relates to a float caliper for measuring the M value of a spline and a method for measuring the M value of a spline, belonging to the field of spline M value measurement technology. Background Technology

[0002] In gearboxes, there is a shifting mechanism that utilizes a sliding sleeve to disengage or engage with the meshing teeth on different gears at its two ends, achieving different output speeds and torques. To prevent disengagement, the internal spline teeth of the sliding sleeve and the external spline meshing teeth of the gear shifting teeth are designed as inverted conical teeth. To achieve the designed fit, the thickness or M value of the internal and external spline teeth needs to be controlled (tooth thickness and M value can be calculated interchangeably). Current technology typically places a standard ball gauge bar of the same diameter in each of two opposing tooth slots in the internal gear or internal spline hole, and then measures the straight-line distance between the two standard ball gauge bars. The resulting dimension is the bar spacing, referred to in the industry as the M value. M value measurement falls under the category of length dimension measurement, and its accuracy and efficiency mainly depend on the measuring tools and standard ball gauge bars used. Currently, there are two main types of measuring tools used in this industry for M value measurement: vernier calipers and standard gauge blocks. For products with low precision requirements, the M value between two standard ball gauge bars is directly measured using vernier calipers; for products with high precision requirements, a combination of standard gauge blocks is used to measure the M value. While using vernier calipers is simple, it results in significant measurement errors. Using a combination of standard gauge blocks offers high accuracy, but its efficiency is too low and it requires a relatively high level of operator skill. Therefore, the measurement of the M value of splines or gears has the following main drawbacks:

[0003] 1. The same gauge cannot be used interchangeably with internal and external gears;

[0004] 2. The operation process is complex and requires a high level of experience and skill from the operators;

[0005] 3. The adjustable stroke is relatively small, requiring high accuracy from the standard ball measuring rod;

[0006] 4. When measuring bevel splines or gears, it is impossible to guarantee that the M value will be measured at the same cross-sectional position every time, resulting in low measurement reliability.

[0007] The relevant patent documents retrieved include:

[0008] 1. CN201521100665.6 - A measuring tool for measuring the M value of a spline;

[0009] 2. CN201620526356.3 - External spline measuring tool;

[0010] 3. CN201810891029.1 - Measuring device for M-value of internal gears and internal splines;

[0011] 4. CN201811263508.5 - A measuring tool and method for measuring the wear of involute internal splines;

[0012] 5. CN201811368107.6 - A gear M-value measuring device and testing method;

[0013] 6. CN201820298902.1 - Handheld internal spline M-value inspection tool;

[0014] 7. CN202220481103.4 - Measuring device for the M value of small internal splines without positioning reference. Summary of the Invention

[0015] The float caliper for measuring the M-value of splines provided by this invention is simple and easy to operate. Its measurement accuracy is independent of the precision of the ball probe, resulting in higher accuracy and reliability. It offers a larger adjustable stroke and requires less operator skill. Measuring the M-value of splines of different specifications only requires changing the ball probe and the M-value standard block, and adjusting the orientation of the ball tips of the two probes to detect both internal and external splines. This provides greater versatility and practicality, avoiding measurement errors caused by different measurement cross-sectional positions in tapered splines, and improving the reliability of tapered spline M-value measurements. This invention also provides a method for measuring the M-value of splines.

[0016] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0017] A float caliper for measuring the M value of a spline includes a main scale, a vernier scale that mates with the main scale, a fixed jaw on the main scale, a movable jaw on the float scale that aligns with the fixed jaw, and a ball measuring rod that detachably mates with the spline being measured and can be mounted on both the fixed and movable jaws. The caliper is characterized by further including an M-value standard block having the standard M value of the spline being measured. The main scale includes a measuring instrument body and a movable adjustable main scale housed within the measuring instrument body. The fixed jaw is integrally formed with the measuring instrument body. The vernier scale is movable and fitted onto the measuring instrument body, mates with the adjustable main scale for measurement, and the M-value standard block is radially positioned as the ball measuring rod extends into the instrument body.

[0018] Preferably, the measuring instrument body has a main scale guide groove, an adjustable main scale guide fitting is installed in the main scale guide groove, a vernier scale guide fitting is sleeved on the measuring instrument body, and an adjustment and positioning component is installed on the adjustable main scale. The adjustable main scale moves on the measuring instrument body as the adjustment and positioning component is adjusted, and is positioned as the adjustment and positioning component is positioned.

[0019] Preferably, the adjustable main scale has a convex cross-section, and the side of the adjustable main scale with the scale lines is flush with the outer surface of the measuring instrument body. The scale lines of the vernier scale are set below the scale lines of the adjustable main scale. Tightening the knurled locking screw on the vernier scale will position the float on the measuring instrument body.

[0020] Preferably, the adjustment and positioning assembly includes a screw fixed to one end of the adjustable main scale, a knurled adjusting nut threaded with the screw, and a second knurled locking screw threaded with the adjustable main scale. The measuring instrument body has a through hole for the screw to pass through and a groove for accommodating the knurled adjusting nut. The screw passes through the through hole and is fixed to the adjustable main scale. As the knurled adjusting nut rotates, the screw drives the adjustable main scale to move in the guide groove of the main scale. The second knurled locking screw is located at both ends of the adjustable main scale. The adjustable main scale is positioned as the second knurled locking screw is tightened.

[0021] Preferably, the ball testing rod consists of a threaded rod body and a detection ball head integrally formed at one end of the rod body and mating with the spline being tested. The lower ends of the fixed claw and the movable claw are provided with mounting holes that mate with the rod body. When mating with the internal spline, the detection ball heads of the two ball testing rods are arranged opposite each other, and when mating with the external spline, the detection ball heads of the two ball testing rods are arranged back to back.

[0022] Preferably, the fixed jaw and the movable jaw are both rectangular in cross-section. Both the fixed jaw and the movable jaw are equipped with a measuring section control block that can contact the end face of the spline being measured. The measuring section control block is guided and fitted onto the fixed jaw and the movable jaw, and is positioned on the fixed jaw and the movable jaw by knurled locking screws.

[0023] Preferably, the M-value standard block is divided into an internal spline M-value standard block with internal splines and an external spline M-value standard block with external splines.

[0024] The method for measuring the spline M value, using the float caliper described above, is characterized by the following steps:

[0025] S1: Select the corresponding ball probe and M-value standard block according to the M-value measurement requirements of the spline being measured, and then install the ball probe on the fixed jaw and the movable jaw;

[0026] S2: Place the M-value standard block between the fixed jaw and the movable jaw, move the vernier scale so that the ball measuring rods on the fixed jaw and the movable jaw respectively extend into the spline groove of the M-value standard block, and position the M-value standard block radially with the positioning float.

[0027] S3: Move the adjustable main scale on the main body of the measuring instrument so that the reading measured by the adjustable main scale and the float scale is the standard M value of the M value standard block, and position the adjustable main scale on the main body of the measuring instrument.

[0028] S4: Loosen the positioning of the float scale, remove the M-value standard block, place the spline to be measured between the fixed jaw and the movable jaw, move the vernier scale so that the ball measuring rods on the fixed jaw and the movable jaw extend into the spline groove of the spline to be measured, and position the float scale radially to position the spline to be measured.

[0029] S5: Read the reading obtained by combining the adjustable main scale and the float scale, which is the M value of the spline being measured.

[0030] Preferably, step S1 specifically refers to:

[0031] When measuring the M value of an external spline, first select the corresponding ball probe and external spline M value standard block according to the measurement requirements of the M value of the spline being measured, and then install the ball probe on the fixed jaw and the movable jaw and set the detection ball heads of the two ball probes relative to each other;

[0032] When measuring the M value of an internal spline, first select the corresponding ball probe and internal spline M value standard block according to the measurement requirements of the spline being measured. Then, install the ball probe on the fixed jaw and the movable jaw and set the detection ball heads of the two ball probes back to back.

[0033] Preferably, in step S4, after removing the M-value standard block, the position of the measuring section control block on the fixed jaw and the movable jaw is adjusted according to the measurement position of the M-value of the spline being tested, so that the distance between the measuring section control block and the center of the detection ball head is equal to the distance from the position where the detection ball head mates with the spline being tested to the upper end face of the spline being tested. Then, the spline being tested is placed between the fixed jaw and the movable jaw, so that when the spline being tested is radially positioned, its upper end face contacts the measuring section control block.

[0034] The beneficial effects of the invention are:

[0035] The float caliper of the present invention for measuring the M value of a spline includes a main measuring body and an adjustable main scale. Both the adjustable main scale and the vernier scale are movable on the measuring body. The M value standard block cooperates with the ball probes on the fixed jaws and the movable jaws to form radial positioning. When measuring the M value of a spline, the M value standard block of the spline to be measured is first radially positioned between the two ball probes. Then, the adjustable main scale is moved on the measuring body so that the reading measured by the adjustable main scale and the float scale is the standard M value of the M value standard block. Positioning the adjustable main scale forms the calibration of the standard M value of the spline to be measured. After that, the M value of the spline to be measured is performed. During the measurement process, only the float scale needs to be moved, and the measured value of the adjustable main scale and the float scale after the movement is read, which is the M value of the spline to be measured. The adjustable main scale is used for calibration of the standard M value, and then the vernier scale is moved to measure the M value of the spline being measured. The operation is simple and easy to perform. The measurement accuracy is determined by the scale of the adjustable main scale, the scale of the vernier scale, and the standard M value of the M value standard block. It does not depend on the accuracy of the ball measuring rod, so the measurement accuracy and reliability are higher. The adjustable stroke is determined by the length of the adjustable main scale, and the adjustable stroke is larger. The measurement operation is similar to that of ordinary float calipers, and the requirements for operators are low. To measure the M value of splines of different specifications, only the ball measuring rod and the M value standard block need to be replaced. The fixed jaw and the movable jaw are respectively equipped with ball measuring rods. Only by adjusting the orientation of the ball heads of the two ball measuring rods can the detection of internal splines and external splines be achieved, which has higher versatility and practicality.

[0036] Measurement section control blocks are installed on the fixed and movable jaws respectively. The positions of the measurement section control blocks on the fixed and movable jaws are adjustable. When measuring straight splines, the measurement section control blocks contact the end face of the spline being measured, ensuring that the axis of the spline being measured is parallel to the fixed jaws without tilting, thus improving the accuracy of the measurement. When measuring tapered splines, the measurement section control blocks contact the end face of the spline being measured, ensuring that the ball probe is aligned with the section at the same distance from the end face for each measurement of the same specification product. This ensures that the section position is the same for each measurement, avoiding measurement errors caused by different measurement section positions for tapered splines, and improving the reliability of the measurement of the M value of tapered splines. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of a float caliper used to measure the M value of a spline when the ball measuring rod is fitted with a standard block for the M value of the internal spline.

[0038] Figure 2 This is a schematic diagram showing the fit between the ball measuring rod and the standard block with the M value of the internal spline.

[0039] Figure 3 This is a schematic diagram of a float caliper used to measure the M value of a spline when the ball measuring rod is used in conjunction with a standard block for the M value of an external spline.

[0040] Figure 4 This is a schematic diagram showing the fit between the ball measuring rod and the standard block with the M value of the internal spline.

[0041] Figure 5 This is a schematic diagram showing the relative positioning of the measuring ball head on the ball measuring rod of the fixed jaw and the movable jaw.

[0042] Figure 6 A cross-sectional schematic diagram of the assembly of the main scale, adjustable main scale, and vernier scale of the measuring instrument. Detailed Implementation

[0043] The following is combined Figures 1-6 The embodiments of the present invention will be described in detail below.

[0044] A float caliper for measuring the M value of a spline includes a main scale 1, a vernier scale 2 that mates with the main scale 1, a fixed jaw 3 on the main scale 1, a movable jaw 4 aligned with the fixed jaw 3 on the float scale 2, and a ball measuring rod 5 detachably mounted on both the fixed jaw 3 and the movable jaw 4 to mate with the spline being measured. The caliper is characterized by further including an M-value standard block 6 with the standard M value of the spline being measured. The main scale 1 includes a measuring instrument body 7 and a movable adjustable main scale 8 housed within the measuring instrument body 7. The fixed jaw 3 is integrally formed with the measuring instrument body 7. The vernier scale 2 is movable and fitted onto the measuring instrument body 7, mates with the adjustable main scale 8 for measurement, and the M-value standard block 6 is radially positioned as the ball measuring rod 5 extends into the instrument.

[0045] The float caliper described above for measuring the M value of a spline includes a main scale 1 comprising a measuring body 7 and an adjustable main scale 8. Both the adjustable main scale 8 and the vernier scale 2 can move on the measuring body 7. The M value standard block 6 cooperates with the ball measuring rods 5 on the fixed jaw 3 and the movable jaw 4 to form radial positioning. When measuring the M value of a spline, the M value standard block 6 of the spline to be measured is first radially positioned between the two ball measuring rods 5. Then, the adjustable main scale 8 is moved on the measuring body 7 so that the reading measured by the adjustable main scale 8 and the float scale 2 is the standard M value of the M value standard block. Positioning the adjustable main scale 8 forms the calibration of the standard M value of the spline to be measured. After that, the M value of the spline to be measured is performed. During the measurement process, only the float scale 2 needs to be moved, and the measured value of the adjustable main scale 8 and the float scale 2 after the movement is read, which is the value of the spline to be measured. M-value: The adjustable main scale 8 is moved to calibrate the standard M-value, and the vernier scale 2 is moved to measure the M-value of the spline being measured. The operation is simple and easy to perform. The measurement accuracy is determined by the scale of the adjustable main scale 8, the scale of the vernier scale 2, and the standard M-value of the M-value standard block 6, and does not depend on the accuracy of the ball measuring rod 5. The measurement accuracy and reliability are higher. The adjustable stroke is determined by the length of the adjustable main scale 8, and the adjustable stroke is larger. The measurement operation is similar to that of ordinary float calipers, and the requirements for operators are low. To measure the M-value of splines of different specifications, only the ball measuring rod 5 and the M-value standard block 6 need to be replaced. The fixed jaw 3 and the movable jaw 4 are respectively equipped with ball measuring rods 5. Only the orientation of the ball heads of the two ball measuring rods 5 needs to be adjusted to realize the detection of internal splines and external splines. The versatility and practicality are higher.

[0046] The measuring instrument body 7 has a main scale guide groove 71. An adjustable main scale 8 is guided and fitted into the main scale guide groove 71. A vernier caliper 2 is guided and fitted onto the measuring instrument body 7. An adjustment and positioning component 9 is mounted on the adjustable main scale 8. The adjustable main scale 8 moves along the measuring instrument body 7 as the adjustment and positioning component 9 is adjusted, and is positioned accordingly. Both the adjustable main scale 8 and the vernier caliper 2 are guided and fitted with the measuring instrument body 7, allowing them to move along the measuring instrument body 7. The adjustment and positioning component 9 drives the adjustable main scale 8 to perform guided movement on the measuring instrument body 7. When calibrating the M-value standard block, the adjustable main scale 8 is moved by adjusting the positioning component 8, so that the reading measured by the adjustable main scale 8 and the vernier caliper 2 is the standard M-value of the M-value standard block. Then, the adjustable main scale 8 is positioned so that when measuring splines, the adjustable main scale 8 remains stationary, and only the vernier caliper 2 moves. After the adjustable main scale 8 is positioned, splines of the same specification can be measured. When it is necessary to measure splines of different specifications, the adjustable main scale 8 is calibrated using the M-value standard block 6 with the standard M-value of the spline to be measured. After calibrating the position of the adjustable main scale 8, the spline is measured. The adjustable main scale 8 can move and be positioned in the measuring instrument body 7 with the adjustment and positioning component 9. It is convenient to measure the M-value of splines of different specifications by simply calibrating the adjustable main scale 8 to determine the standard M-value of the spline to be measured, and then measuring the spline to be measured. This enables the measurement of splines of different specifications, and the operation is simple and highly practical.

[0047] The adjustable main scale 8 has a convex cross-section. The side of the adjustable main scale 8 with graduation lines is flush with the outer surface of the measuring instrument body 7. The graduation lines of the vernier scale 2 are positioned below the graduation lines of the adjustable main scale 8. Tightening the knurled locking screw 21 on the vernier scale 2 positions the float on the measuring instrument body 7. As shown in the attached diagram, the adjustable main scale 8 has a convex cross-section. The cross-section of the main scale guide groove 71 matches the adjustable main scale 8, confining the adjustable main scale 8 within the measuring instrument body 7. It can only move along the main scale guide groove 71, ensuring the reliability of the engagement between the adjustable main scale 8 and the float 2. The matching arrangement of the graduation lines of the adjustable main scale 8 and the float 2 is the same as the positional distribution of the main scale graduation lines and vernier scale graduation lines in a conventional vernier caliper. During calibration and measurement, the matching of the graduation lines of the adjustable main scale 8 and the float 2 enables the reading of values.

[0048] The adjustment and positioning assembly 9 includes a screw 91 fixed to one end of the adjustable main scale 8, a knurled adjusting nut 92 threaded with the screw 91, and a knurled locking screw 93 threaded with the adjustable main scale 8. The measuring instrument body 7 has a through hole 72 for the screw 91 to pass through and a groove 73 for accommodating the knurled adjusting nut 92. The screw 91 passes through the through hole 72 and is fixed to the adjustable main scale 8. As the knurled adjusting nut 92 rotates, the screw 91 drives the adjustable main scale 8 to move in the main scale guide groove 71. The knurled locking screw 93 is located at both ends of the adjustable main scale 8. The adjustable main scale 8 is positioned as the knurled locking screw 93 is tightened. The knurled adjusting nut 92 can only rotate within the groove 73, driving the screw 91 to move within the through hole 72. The screw 91 then drives the adjustable main scale 8 to move within the main scale guide groove 71, adjusting its position. After the adjustable main scale 8 is in place, the knurled locking screw 93 is tightened to position the adjustable main scale 8, preventing it from moving during spline measurement. The movement of the adjustable main scale 8 calibrates the standard M value of the M value standard block 6, ensuring that the measurement accuracy of the spline is determined by the accuracy of the scale lines of the adjustable main scale 8, the accuracy of the scale lines of the vernier caliper 2, and the dimensional accuracy of the M value standard block 6. This eliminates the dependence on the accuracy of the ball measuring rod 5, thus reducing the requirement for its accuracy and effectively improving measurement accuracy.

[0049] The ball measuring rod 5 consists of a threaded rod body 51 and a detection ball head 52 integrally formed at one end of the rod body 51 and mating with the spline being measured. The lower ends of the fixed jaw 3 and the movable jaw 4 are both provided with mounting holes that mate with the rod body 51. When mating with an internal spline, the detection ball heads 52 of the two ball measuring rods 5 are positioned opposite each other; when mating with an external spline, the detection ball heads 52 of the two ball measuring rods 5 are positioned back-to-back. The rod body 51 passes through the mounting holes and is secured with a nut, making the measuring rod 5 detachable and adaptable to different keyway distributions of internal and external splines. When the detection ball heads 52 of the two ball measuring rods 51 are positioned opposite each other, they mate with the internal spline; when positioned back-to-back, they mate with the external spline. Measuring internal and external splines can be achieved simply by adjusting the position of the detection ball heads 52 in the ball measuring rod 5, making it convenient and practical.

[0050] The fixed jaw 3 and the movable jaw 4 both have rectangular cross-sections. Each jaw is equipped with a measuring section control block 10 that contacts the end face of the spline being measured. The measuring section control block 10 is guided and fitted onto the fixed jaw 3 and the movable jaw 4, and is positioned on them by knurled locking screws 11. The position of the measuring section control block 10 on the fixed jaw 3 and the movable jaw 4 is adjustable. When measuring a spur spline, the measuring section control block 10 contacts the end face of the spline being measured, ensuring that the axis of the spline being measured is parallel to the fixed jaw and does not tilt, thus improving measurement accuracy. When measuring a tapered spline, the measuring section control block 10 contacts the end face of the spline being measured, ensuring that the ball probe 5 is always positioned at the same distance from the end face for each measurement of the same specification product. This ensures that the cross-sectional position is the same for each measurement, avoiding measurement errors caused by different measuring section positions for tapered splines, and improving the reliability of the M-value measurement for tapered splines.

[0051] The M-value standard block 6 is divided into an internal spline M-value standard block 61 with internal splines and an external spline M-value standard block 62 with external splines. For each specification of the spline being tested, an internal spline standard block 61 and an external spline M-value standard block 6 must be provided for calibration of internal and external splines of various specifications.

[0052] This invention also protects a method for measuring the M value of a spline, which uses the float caliper described above for measuring the M value of a spline, characterized by comprising the following steps:

[0053] S1: Select the corresponding ball probe 5 and M value standard block 6 according to the M value measurement requirements of the spline to be measured, and then install the ball probe 5 on the fixed jaw 3 and the movable jaw 4;

[0054] S2: Place the M-value standard block 6 between the fixed jaw 3 and the movable jaw 4, move the vernier scale 2 so that the ball measuring rods on the fixed jaw 3 and the movable jaw 4 respectively extend into the spline groove of the M-value standard block 3, and position the M-value standard block radially, so that the M-value standard block 6 of the spline to be measured is radially positioned between the two ball measuring rods 5.

[0055] S3: Move the adjustable main scale 8 on the measuring instrument body 7 so that the reading measured by the adjustable main scale 8 and the float scale 2 is the standard M value of the M value standard block 6. Position the adjustable main scale 8 on the measuring instrument body 7 to form a scale calibration for the standard M value of the spline being measured.

[0056] S4: Loosen the positioning of the float ruler 2, remove the M value standard block 6, and then place the spline to be measured between the fixed jaw 3 and the movable jaw 4. Move the vernier ruler 2 so that the ball measuring rod 5 on the fixed jaw 3 and the movable jaw 4 respectively extend into the spline groove of the spline to be measured. Position the float ruler 2 to radially position the spline to be measured.

[0057] S5: Read the reading obtained by combining the adjustable main scale 8 and the float scale 2, which is the M value of the spline being measured.

[0058] When measuring the M value of a spline, first, the M value standard block 6 of the spline to be measured is radially positioned between the two ball measuring rods 5. Then, the adjustable main scale 8 is moved on the main body 7 of the measuring instrument so that the reading measured by the adjustable main scale 8 and the float scale 2 is the standard M value of the M value standard block. Positioning the adjustable main scale 8 forms the calibration of the standard M value of the spline to be measured. After that, the M value of the spline to be measured is performed. During the measurement process, only the float scale 2 needs to be moved, and the measured value of the adjustable main scale 8 and the float scale 2 after the movement is read. This is the M value of the spline to be measured. The measurement process is simple and easy to operate. To measure a spline of a certain specification, the adjustable main scale 8 is calibrated once, which can form an accurate measurement. The operation is convenient and simple, and it is highly practical.

[0059] Specifically, step S1 refers to:

[0060] When measuring the M value of an external spline, first select the corresponding ball probe 5 and external spline M value standard block 62 according to the measurement requirements of the M value of the spline being measured. Then, install the ball probe 5 on the fixed jaw 3 and the movable jaw 4 and set the detection ball heads 52 of the two ball probes 5 relative to each other.

[0061] When measuring the M value of an internal spline, first select the corresponding ball probe 5 and internal spline M value standard block 61 according to the measurement requirements of the M value of the spline being measured. Then, install the ball probe 5 on the fixed jaw 3 and the movable jaw 4 and set the detection ball heads 52 of the two ball probes 5 back to back.

[0062] For each specification of spline under test, the corresponding M-value standard block 6 must be equipped with an internal spline standard block 61 and an external spline M-value standard block 62 for calibration of internal and external splines of various specifications.

[0063] In step S4, after removing the M-value standard block 6, the position of the measuring section control block 10 on the fixed jaw 3 and the movable jaw 4 is adjusted according to the measurement position of the M-value of the spline being tested. This is done so that the distance between the measuring section control block 6 and the center of the detection ball head 52 is equal to the distance from the position where the detection ball head 52 mates with the spline being tested to the upper end face of the spline being tested. Then, the spline being tested is placed between the fixed jaw 3 and the movable jaw 4 so that its upper end face contacts the measuring section control block 10 when the spline being tested is radially positioned. The distance between the measuring section control block 6 and the center of the detection ball head 52 is equal to the distance from the position where the detection ball head 52 mates with the spline being measured to the upper end face of the spline being measured. This ensures that when measuring a tapered spline, the measuring section control block 10 is in contact with the upper end face of the spline being measured. The distance between the measuring section control block 6 and the center of the detection ball head 52 remains constant, ensuring that the ball probe 5 mates with the section at the same distance from the end face during each measurement of the same specification product. This ensures that the section position is the same for each measurement, avoids measurement errors caused by different measuring section positions of the tapered spline, and improves the measurement reliability of the M value of the tapered spline.

[0064] The technical solutions of the embodiments of the present invention have been fully described above with reference to the accompanying drawings. It should be noted that the described embodiments are only a part of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

Claims

1. A float caliper for measuring the M value of a spline, comprising a main scale, a vernier scale cooperating with the main scale, a fixed jaw on the main scale, a movable jaw on the float scale aligned with the fixed jaw, and a ball measuring rod detachably mounted on both the fixed jaw and the movable jaw to cooperate with the spline being measured, characterized in that: Also include the M value standard block with the measured spline standard M value, the main ruler includes the measuring ruler body and the movable adjustable main ruler installed in the measuring ruler body, the fixed jaw is integrally formed with the measuring ruler body, the vernier ruler is movably sleeved on the measuring ruler body, and the standard M value of the M value standard block is radially positioned with the extension of the ball measuring rod; The measuring ruler body is provided with a main ruler guide groove, the adjustable main ruler is guided and matched and installed in the main ruler guide groove, the vernier ruler is guided and matched and sleeved on the measuring ruler body, the adjustable main ruler is provided with an adjusting and positioning assembly, the adjustable main ruler is guided and moved on the measuring ruler body with the adjustment of the adjusting and positioning assembly, and the adjustable main ruler is positioned with the positioning of the adjusting and positioning assembly; The adjustable main ruler is provided with the adjusting and positioning assembly, the cross section of the adjustable main ruler is in the shape of a Chinese character "K", one side of the adjustable main ruler provided with scale lines is flush with the outer surface of the measuring ruler body, the scale lines of the vernier ruler are matched and arranged below the scale lines of the adjustable main ruler, and the knurled locking screw on the vernier ruler is screwed to position the float ruler on the measuring ruler body; The cross sections of the fixed jaw and the movable jaw are both in the shape of a rectangle, the fixed jaw and the movable jaw are both provided with a measuring section control block capable of being in contact with the end surface of the measured spline, the measuring section control block is guided and matched and sleeved on the fixed jaw and the movable jaw, and is positioned on the fixed jaw and the movable jaw through the knurled locking screw three. The reading of the measurement of the adjustable main ruler and the float ruler is the standard M value of the M value standard block, the adjustable main ruler is positioned to form the sizing and calibration of the standard M value of the measured spline, and then the M value measurement of the measured spline is performed, in the measurement process, only the float ruler needs to be moved, and the measurement value of the adjustable main ruler and the float ruler after the movement is read, that is, the M value of the measured spline.

2. The float caliper for measuring the value of the spline M according to claim 1, characterized in that: The adjusting and positioning assembly comprises a screw rod fixed with one end of the adjustable main ruler, a knurled adjusting nut threadedly matched with the screw rod, and a knurled locking screw two threadedly matched with the adjustable main ruler, the measuring ruler body is provided with a through hole through which the screw rod passes and a groove accommodating the knurled adjusting nut, the screw rod is fixed with the adjustable main ruler by passing through the through hole, the screw rod guides and moves the adjustable main ruler in the main ruler guide groove with the rotation of the knurled adjusting nut, and the knurled locking screw two is arranged at two ends of the adjustable main ruler, and the adjustable main ruler is positioned with the screwing of the knurled locking screw two.

3. The float caliper for measuring the value of the spline M according to claim 1, characterized in that: The ball measuring rod is composed of a threaded rod body and a detection ball head integrally formed at one end of the rod body and matched with the measured spline, the lower ends of the fixed jaw and the movable jaw are both provided with an installation hole matched with the rod body, the detection ball heads of the two ball measuring rods are oppositely arranged when matched with the internal spline, and the detection ball heads of the two ball measuring rods are oppositely arranged when matched with the external spline.

4. The float caliper for measuring the value of the spline M according to claim 1, characterized in that: The M value standard block is divided into an internal spline M value standard block with an internal spline and an external spline M value standard block with an external spline.

5. A method of measuring the M value of splines, using the float caliper for measuring the M value of splines according to any one of claims 1 to 4, characterized in that, The method comprises the following steps: S1: selecting corresponding ball measuring rods and M value standard blocks according to the M value measurement requirements of the measured spline, and then installing the ball measuring rods on the fixed jaw and the movable jaw; S2: placing the M value standard block between the fixed jaw and the movable jaw, moving the vernier ruler to make the ball measuring rods on the fixed jaw and the movable jaw respectively extend into the spline groove of the M value standard block, and positioning the float ruler to radially position the M value standard block; S3: Move the adjustable main ruler on the gauge body, make the adjustable main ruler and the float ruler cooperate to measure the reading as the standard M value of the M value standard block, and position the adjustable main ruler on the gauge body; S4: Loosen the positioning of the float ruler, take down the M value standard block, and then place the measured spline between the fixed jaw and the movable jaw, move the cursor ruler to make the ball measuring rods on the fixed jaw and the movable jaw respectively extend into the spline groove of the measured spline, position the float ruler to position the measured spline radially; S5: Read the reading of the adjustable main ruler and the float ruler cooperating to measure, which is the M value of the measured spline.

6. The method of measuring the M value of splines according to claim 5, characterized in that: Step S1 is specifically: When measuring the M value of the outer spline, first select the corresponding ball measuring rod and the outer spline M value standard block according to the M value measurement requirement of the measured spline, then install the ball measuring rod on the fixed jaw and the movable jaw and make the detection ball heads of the two ball measuring rods oppositely arranged; When measuring the M value of the inner spline, first select the corresponding ball measuring rod and the inner spline M value standard block according to the M value measurement requirement of the measured spline, then install the ball measuring rod on the fixed jaw and the movable jaw and make the detection ball heads of the two ball measuring rods oppositely arranged.

7. The method of measuring the spline M value according to claim 5, characterized by: In step S4, after taking down the M value standard block, according to the measurement position of the M value of the measured spline, adjust the position of the measurement section control block on the fixed jaw and the movable jaw, so that the distance between the measurement section control block and the center of the detection ball head is equal to the distance from the position where the detection ball head cooperates with the measured spline to the upper end surface of the measured spline, and then place the measured spline between the fixed jaw and the movable jaw, so that when the measured spline is positioned radially, its upper end surface is in contact with the measurement section control block.

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