On-line measuring device for chamfer of inner hole of gear spline of differential mechanism

Abstract

The invention relates to the technical field of angle measurement, in particular to an on-line measuring device for a chamfer of a spline inner hole of a differential gear, and solves the problems that the measurement of the chamfer of the spline inner hole of the differential gear in the prior art needs a long time and cannot meet the on-line production requirement and the like. The measuring head is used as a fixed positioning point for positioning an angle surface, and the measuring head on the lever is used as a movable measuring point for measuring angle change; the distance between the positioning point and the movable measuring point is 1.72 mm; the bottom plate is inclined by 67.5 degrees, a groove used for installing a measuring support is machined in the bottom plate, and the measuring support and the bottom plate are inclined by 67.5 degrees; the large-end shaft diameter of the positioning seat is provided with a positioning groove used for being in sliding fit with the measuring support, and the small-end shaft diameter of the positioning seat is used for positioning a spline inner hole of a to-be-measured product. The display device is connected with a transmission measuring point at the other end of the lever and used for displaying angle changes measured by the movable measuring point. The device disclosed by the invention is simple in online measurement operation, and rapid, accurate and stable in measurement.

Description

Technical Field

[0001] This invention relates to the field of angle measurement technology, and specifically to an online measuring device for the chamfer of the spline inner hole of a differential gear. Background Technology

[0002] In the automotive manufacturing industry, the differential is one of the most crucial components. 99% of cars rely on differentials to operate; therefore, the quality of the differential directly affects whether a car can run. The differential structure consists of a differential housing, gears, planetary gears, and a ring gear. Both the gears and planetary gears are bevel gears. Because the differential has a ball-cage structure, the gears and planetary gears are installed inside. Two gears are on one axis, and the planetary gears are on another axis, with the two shafts perpendicularly intersecting. Each gear meshes with two planetary gears. Since the contact surface between the planetary gears and the differential housing is spherical, and the gears are bevel gears, the two pairs of meshing gears and planetary gears within the differential are called bevel gears. The gear's inner bore is an internal spline bore, which transmits power to the car wheels through a splined shaft connection. In the connection between the spline bore and the splined shaft, the spline bore insertion end has a guide angle (matching the splined shaft), and the angle of this guide angle must be precisely controlled during manufacturing.

[0003] In existing technologies, differential production is basically customized for automobiles, so its production is characterized by large-scale automated production. The machining time for a gear may be one minute. Using traditional methods, a coordinate measuring machine or profile measuring instrument is used to detect the angle. When the measuring instrument has no other measurement tasks, the detection time is about ten minutes. However, when the measuring instrument has other measurement tasks, the detection time becomes uncertain. If the measurement result is not finalized, differential production must be stopped. The resulting economic loss is unacceptable to the manufacturer. Therefore, a measuring device that can quickly detect within one minute is one of the best options at present.

[0004] In summary, existing methods for measuring the guide angle using coordinate measuring machines or profile measuring instruments are time-consuming and cannot meet the needs of online production. Therefore, there is an urgent need to develop a universal internal hole angle measuring device. Summary of the Invention

[0005] This invention addresses the problem that measuring the chamfer of the spline inner hole of a differential gear requires a long time and cannot meet the needs of online production, by providing an online measuring device for the chamfer of the spline inner hole of a differential gear.

[0006] An online measuring device for the chamfering of the spline inner hole of a differential gear, the online measuring device comprising a base plate, a measuring support, a probe, a positioning seat, a lever, and a display device; The probe and lever are mounted on the measuring support to form an integrated structure. The probe serves as a fixed positioning point to locate the angle surface, while the probe on the lever serves as a movable measuring point to measure changes in the angle surface. The distance between the positioning point and the movable measuring point is 1.72 mm. The base plate is tilted at 67.5°; a groove is machined on the base plate for mounting a measuring support, the measuring support being tilted at 67.5° relative to the base plate; The positioning seat is configured as a stepped shaft structure, with a positioning groove machined on the large end shaft diameter for sliding fit with the measuring support, and the small end shaft diameter for positioning the spline inner hole of the product being measured; The display device is connected to the other end of the lever to transmit the measuring point, and is used to display the angle change measured by the active measuring point.

[0007] The beneficial effects of this invention are: The online measuring device of the present invention has a fixed probe installed on the measuring support and a probe with a movable measuring point installed by a lever. This ensures that the distance between the probe and the movable measuring point is 1.72mm, avoiding the instability caused by the two measuring points due to non-integrated installation, which affects the measurement results.

[0008] The online measuring device of the present invention integrates the measuring support, the probe, and the lever into a single structure, which ensures that the positional relationship between the movable measuring points on the probe and the lever is fixed. Since the two measuring points are integrated into one component, the overall integrity is good, which is conducive to installation on the base plate. After installation, the distance between the two measuring points is 1.72mm and will not change, thus ensuring the accuracy of the measurement.

[0009] The online measuring device of the present invention is designed with a measuring support thickness of 12mm, which matches the width of the positioning groove at the center of the positioning seat, thus ensuring the measurement result of the normal angle of the cone hole.

[0010] The online measuring device described in this invention can be applied to measure the chamfer angle of the internal spline hole of different test parts. Since the chamfer surface lengths and angles vary among different test parts, and the measuring point must avoid the tooth groove position, a corresponding positioning seat is designed for each different test part. The positioning seat is equipped with a positioning pin hole with a positioning tooth groove, which ensures that the fixed point probe and the moving measuring point fall on the inner surface of the cone, while also ensuring that the measuring point measures the angle passing through the center plane.

[0011] The online measuring device of the present invention uses a base plate made of low-carbon steel through carburizing and quenching process to ensure high surface hardness and soft core, with good machinability of the core. The base plate is machined at a certain tilt angle to facilitate operation by the operator.

[0012] The online measurement device described in this invention is simple to operate, fast, accurate and stable in online measurement. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of an online measuring device for the chamfering of the spline inner hole of a differential gear according to the present invention; Figure 2 In order to be in Figure 1 A structural diagram showing the addition of the tested product component; Figure 3 A schematic diagram illustrating the principle of measuring the chamfer of the inner hole of the differential spline; Figure 4 This is the front view of the base plate; Figure 5 This is a top view of the base plate; Figure 6 This is the front view of the measuring support; Figure 7 for Figure 6 The left view; Figure 8 for Figure 6 The right view; Figure 9 This is a schematic diagram of the lever structure; Figure 10 This is a schematic diagram of the probe's structure; Figure 11 A schematic diagram showing the structure for mounting the probe and lever on the measuring support; Figure 12 This is the front view of the positioning seat; Figure 13 for Figure 12 Side view; Figure 14 for Figure 12 Top view.

[0014] In the diagram: 1. Support plate, 2. Base plate, 2-1. Groove, 3. Measuring support, 3-1. Mounting hole, 3-2. Fixing hole, 3-3. Pin hole, 3-4. Through hole, 3-5. M4 screw hole, 3-6. Locking hole, 4. Probe, 5. Positioning seat, 5-1. Positioning groove, 5-2. Positioning pin hole, 5-3. Positioning probe, 5-4. Threaded locking hole, 6. Product being measured, 7. Lever, 7-1. Moving measuring point, 7-2. Transfer measuring point, 8. Dial indicator. Detailed Implementation

[0015] Combination Figure 1 This embodiment describes an online measuring device for the chamfer of the spline inner hole of a differential gear, which can also be used as a general-purpose inner hole angle measuring device.

[0016] Because the chamfer angle of the differential spline inner hole varies among different tested product parts, generally ranging from 15° to 30°, the angle tolerance range for the same product is required to be ±0.5° to ±3°; the length of the chamfer angle surface varies among different tested product parts, ranging from 2.5mm to 6mm, and the gear inner hole is a spline hole; the chamfer angle surface is not a continuous surface, so the measurement point must avoid the position of the internal spline tooth groove and measure the tooth thickness to ensure measurement accuracy; the size of the spline inner hole varies among different tested product parts, with the inner hole diameter ranging from 24mm to 50mm.

[0017] This embodiment addresses the aforementioned characteristics of the chamfered spline inner hole by designing a fixed positioning point and a movable measuring point that rotates around the positioning point. When the distance between the two points is 1.72mm, the positioning point remains fixed, and the movable measuring point rotates 1° around the fixed positioning point as its axis. The displacement arc length of the movable measuring point is 0.03mm, or 30μm. When the central angle corresponding to this arc is relatively small (the arc angle is small), the arc length corresponding to any 1′ angle within this arc is theoretically equal. That is, for the dimensional change of the arc length from 0° to 1° in the Y-axis direction and the dimensional change of the arc length from 9° to 10° in the Y-axis direction, as shown... Figure 3 As shown, one is 0.03001mm and the other is 0.02956mm. They can be considered approximately equal. When a dial indicator measures the change in the center angle of the two arc segments, the change is the same for each minute, and the error is too small to distinguish. Therefore, by using a dial indicator or displacement sensor to measure the displacement change of a moving point, the angle value can be measured. During measurement, a corresponding calibration piece is needed to mark the standard angle. For different tested product parts, a corresponding locating seat with the appropriate angle is also required. During measurement, if the displacement of the moving measuring point is 1μm, which is 1 / 30 of 1°, the displayed angle change is 2′.

[0018] The online measurement device of this embodiment adopts a measurement method based on dial indicator and sensor to collect and measure linear displacement changes, and displays the dimensional changes in the Y-axis direction. Therefore, a measuring support 3 is designed, on which a fixed probe 4 is installed and a probe with a movable measuring point is installed via lever 7. This ensures that the distance between the probe 4 and the movable measuring point is 1.72mm, avoiding the instability caused by the non-integrated installation affecting the measurement results.

[0019] like Figure 1 and Figure 2 As shown, the online measuring device described in this embodiment includes a support plate 1, a base plate 2, a measuring support 3, a probe 4, a positioning seat 5, a lever 7, and a dial indicator 8; like Figures 4 to 11As shown, the base plate 2 is mounted on the support plate 1 at a 67.5° inclination. A groove 2-1 is machined on the base plate 2. The measuring support 3 is fixedly connected to the groove 2-1 and is also inclined at a 67.5° angle to the base plate 2. The groove is 35mm long and 12mm wide, and it fits the width and thickness of the measuring support 3 without clearance. The 67.5° inclination of the groove 2-1 relative to the base plate 2 mainly depends on the cone hole half-angle of the measured product part 6, which is between 15° and 30°. When the cone angle is 22.5°, the corresponding measurement point of the probe 4 and the lever 7 is 0°, while the corresponding measurement point of 15° and 30° is 0°. The 0° angle relationship between the measuring points of probe 4 and lever 7 is ±7.5°, so its arc length projected onto the Y-axis is also a sine value that can be approximately equal. In addition, the distance between the center of the movable measuring point 7-1 of lever 7 and the base plate 2 is 20mm. Since the measuring device of this embodiment is a universal type, it can adjust the measuring position for different tested product parts 6. When the measuring angle surface of the tested product part 6 is high, the measurement can be achieved by thinning the end face of the positioning seat 5. There are also two ø6 pin holes on the base plate 2 for fastening the base plate 2 and the measuring support 3 into an integral structure.

[0020] like Figures 6 to 8 As shown, the measuring support 3 is provided with a mounting hole 3-1 for mounting the probe 4 and a fixing hole 3-2 for fixing with an M4 screw; a pin hole 3-3 and a locking hole 3-6 for mounting the lever 7; a through hole 3-4 for mounting the display device; and an M4 screw hole 3-5 for fixing the display device on the side of the measuring support 3 perpendicular to the through hole. like Figures 9 to 11 As shown, the probe 4 is mounted on the measuring support 3 through the mounting hole 3-1 and fixed by passing an M4 screw through the fixing hole; the lever 7 is mounted on the measuring support 3 through the pin hole 3-3. When the distance between the probe 4 and the movable measuring point 7-1 on the lever 7 is 1.72mm, it is locked by the locking hole 3-6. The probe 4 and the lever 7 are mounted on the measuring support 3 and form an integral structure with the measuring support 3.

[0021] In this embodiment, the probe 4 serves as a fixed positioning point on the angular plane, and the probe on the lever 7 serves as a movable measuring point 7-1 to measure the change in the angular plane. The 1.72mm is obtained through theoretical calculation. 1° equals 60′, and a circular angle is 360°. Assuming that 1′ corresponds to an arc length of 1μm, the circumference is equal to 0.001×60×360=21.6, and the radius is equal to 21.6÷2π=3.438. Half of the radius is 1.72mm.

[0022] like Figures 12 to 14As shown, the positioning seat 5 is configured as a stepped shaft structure. A positioning groove 5-1, 12mm wide, is machined into the large end of the shaft diameter to allow for sliding clearance with the thickness of the measuring support 3. The positioning groove 5-1 ensures that the movable measuring point 7-1 of the probe 4 and lever 7 can penetrate into the tapered hole of the tested product part 6 to measure the chamfer angle, while also ensuring the measurement of the normal angle through the center. The small end diameter is used to position the spline inner hole of the tested product part 6, and a positioning pin hole 5-2 through the center is located on the small end shaft diameter. A positioning probe 5-3 with a positioning spline tooth groove is installed inside the positioning pin hole 5-2. A threaded locking hole is machined on the small end shaft diameter on the other side perpendicular to the positioning pin hole 5-2. A screw is used to lock the probe through the threaded locking hole 5-4, thus completing the positioning of the product part 6 under test. When the number of teeth on the product part 6 under test is even, the axis of the positioning pin hole 5-2 is parallel to the center plane of the positioning groove 5-1. When the number of teeth on the product part 6 under test is odd, the axis of the positioning pin hole 5-2 is inclined relative to the center plane of the positioning groove 5-1. Because it is a tapered hole machined from a spline hole, the measurement point must avoid the spline tooth groove. The diameter of the positioning seat 5 depends on the size of the spline hole of the product part under test. Therefore, a corresponding positioning seat is required for different product parts under test (the calibration parts for the calibration angle are shared).

[0023] In this embodiment, the display device includes a dial indicator or a sensor device; When using a dial indicator 8 to display the measured angle, the dial indicator 8 rod passes through the through hole 3-4 of the measuring support 3 and abuts against the other end of the lever 7, the measuring point 7-2. The lever 7 adopts an isosceles right triangle structure, so that the angle change value measured by the moving measuring point 7-1 is proportionally displayed through the measuring point 7-2 at the end of the dial indicator 8.

[0024] The measurement principle of the online measurement device described in this embodiment: During measurement, the large end shaft diameter of the positioning seat 5 is placed on the measuring support 3. The positioning groove 5-1 at the center of the large end shaft diameter ensures that the movable measuring point 7-1 of the probe 4 and the lever 7 can be inserted into the cone hole to measure the cone hole angle, while ensuring that the normal angle is measured through the center. When the angle of the tested product part 6 changes from 15° to 30°, its midpoint angle is 22.5°. Therefore, the measuring support 3 is installed on the base plate 2 at a tilt of 67.5°. At this time, the two measuring points on the probe 4 and lever 7 installed on the measuring support 3 are theoretically measuring the value of 0° angle when measuring the 22.5° hole (half angle). Thus, the two points on the probe 4 and lever 7 have an apparent value change of 0° to ±7.5° when measuring the angle from 15° to 30°. 22.5° corresponds to 0°, and 15° and 30° correspond to 7.5° apparent value change. The splined inner hole of the product part 6 under test is fixed on the small end shaft diameter of the positioning seat 5. When the distance between the two measuring points is 1.72mm, it is locked through the locking holes 3-6. At this time, the lever 7 transmits the relative change between the two measuring points to the dial indicator 8. The dial indicator 8 then displays the angle measurement result, that is, the angle is 2′ for every 1μm change of the dial indicator. Assuming that the dial indicator is set to 0 using a 15° calibration piece, the angle of the product part 6 under test is 17°36′, and the dial indicator reading is 78μm. If the angle of the product part 6 under test is 25°... The reading of dial indicator 8 is 307μm or 308μm. If dial indicator 8 is replaced with a sensor device, the actual angle value can be displayed through software programming. Using a 15° calibration piece, the display shows 15°. When the angle of the tested product part 6 is 17°36′, the sensor device's display shows 17.6° or 17°36′. Similarly, when the angle of the tested product part 6 is 25°15′, the sensor device's display shows 25.2° or 25°15′.

[0025] The online measuring device described in this embodiment can be applied to measure the chamfer angle of the internal spline hole of different tested product parts. Considering the different chamfer surface lengths and angles of different tested product parts, and the need for measurement points to avoid the tooth groove positions, a corresponding positioning seat 5 is designed for each different tested product part. A positioning probe 5-3 with a positioning tooth groove is installed on the positioning seat 5. This ensures that the fixed point probe 4 and the movable measuring point 7-1 fall on the inner surface of the conical hole, and also ensures that the measuring point measures the angle passing through the center plane. The diameter of the positioning seat 5 depends on the size of the spline hole of the tested product part.

[0026] In this embodiment, the base plate 2 is made of low-carbon steel through carburizing and quenching process to ensure high surface hardness and soft core, with good machinability of the core. The base plate 2 is machined at a certain tilt angle to facilitate operator operation.

[0027] In this embodiment, the measuring support 3, the probe 4, and the lever 7 are designed as an integrated structure, which ensures that the positional relationship between the movable measuring points on the probe 4 and the lever 7 is fixed, that is, the distance between the two measuring points is 1.72mm. At the same time, the lever 7 transmits the relative changes of the two measuring points to the dial indicator or sensor. Since the two measuring points are integrated into one component, the integrity is good, which is conducive to installation on the base plate 2. After installation, the positional distance of the two measuring points will not change at 1.72mm, ensuring accurate measurement. The measuring support 3 is designed with a thickness of 12mm, which matches the center positioning groove of the positioning seat 5 to ensure the measurement result of the cone hole normal angle.

[0028] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0029] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An online measuring device for the chamfer of the spline inner hole of a differential gear, characterized in that: The online measuring device includes a base plate (2), a measuring support (3), a probe (4), a positioning seat (5), a lever (7), and a display device; The probe (4) and lever (7) are mounted on the measuring support (3) to form an integral structure. The probe (4) serves as a fixed positioning point for positioning the angle surface, and the probe on the lever (7) serves as a movable measuring point (7-1) for measuring the change of the angle surface. The distance between the positioning point and the movable measuring point (7-1) is 1.72 mm. The base plate (2) is tilted at 67.5°; a groove (2-1) is machined on the base plate (2) for installing a measuring support (3), the measuring support (3) being tilted at 67.5° relative to the base plate (2); The positioning seat (5) is configured as a stepped shaft structure, with a positioning groove (5-1) machined on the large end shaft diameter for sliding fit with the measuring support (3); the small end shaft diameter is used to position the spline inner hole of the product being measured. The display device is connected to the other end of the lever (7) to transmit the measuring point (7-2) and is used to display the angle change measured by the active measuring point (7-1).

2. The online measuring device for the chamfer of the spline inner hole of a differential gear according to claim 1, characterized in that: The groove (2-1) on the base plate (2) is 35mm long and 12mm wide, and is used to fit the width and thickness of the measuring support (3) without gap.

3. The online measuring device for the chamfer of the spline inner hole of a differential gear according to claim 1, characterized in that: The measuring support (3) is provided with a mounting hole (3-1) for mounting the probe (4) and a fixing hole (3-2) for fixing with an M4 screw; a pin hole (3-3) and a locking hole (3-6) for mounting the lever (7); a through hole (3-4) for mounting the display device and an M4 screw hole (3-5) for fixing the display device.

4. The online measuring device for the chamfer of the spline inner hole of a differential gear according to claim 1, characterized in that: The display device includes a dial indicator (8) or a sensor device; When the dial indicator (8) is used to measure the angle, the rod of the dial indicator (8) passes through the through hole (3-4) of the measuring support (3) and abuts against the other end of the lever (7) at the transmission measuring point (7-2). The angle change value measured by the moving measuring point (7-1) is proportionally displayed through the end of the dial indicator (8) via the transmission measuring point (7-2).

5. The online measuring device for the chamfer of the spline inner hole of a differential gear according to claim 1, characterized in that: The positioning groove (5-1) of the positioning seat (5) is 12mm wide and is used to slide with the thickness of the measuring support (3). At the same time, the moving measuring point (7-1) of the probe (4) and the lever (7) is inserted into the spline hole of the product part (6) to measure the chamfer angle.

6. The online measuring device for the chamfer of the spline inner hole of a differential gear according to claim 1, characterized in that: The positioning base (5) has a positioning pin hole (5-2) at the center of its small end shaft diameter. A positioning probe (5-3) for positioning the tooth groove of the product part (6) being tested is installed in the positioning pin hole (5-2).

7. The online measuring device for the chamfer of the spline inner hole of a differential gear according to claim 1, characterized in that: The distance between the center of the active measuring point of the lever (7) and the base plate (2) is 20mm; the lever (7) adopts an isosceles right triangle structure.

8. The online measuring device for the chamfer of the spline inner hole of a differential gear according to claim 1, characterized in that: When the online measuring device measures different test parts (6), it sets up corresponding positioning seats (5). The diameter of the positioning seat (5) depends on the size of the spline inner hole of the test part (6).

9. The online measuring device for the chamfer of the spline inner hole of a differential gear according to claim 1, characterized in that: The online measuring device measures the product part (6) whose angle varies from 15° to 30°. When the middle angle is 22.5°, the angle relationship between the moving measuring points of the probe (4) and the lever (7) is 0°. When the corresponding angles are 15° and 30°, the angle relationship between the moving measuring points of the probe (4) and the lever (7) is ±7.5°.

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