Gauge for measuring bottom diameter of milling groove of gear shifting hub

Abstract

The utility model discloses a gear shifting hub milling groove bottom diameter measuring gauge, comprising a bearing disc on which a gear shifting hub with a downward end shaft is arranged; the positioning column extends in the radial direction of the gear shifting hub, and the contact end of the positioning column abuts against the bottom of the positioning milling groove of the gear shifting hub; the extension direction of the dial indicator and the measuring rod is parallel to the positioning column, and the measuring head abuts against the bottom of the detection milling groove of the gear shifting hub. The device further comprises a first limiting strip and a second limiting strip. The first limiting strip and the second limiting strip are fixed in parallel, and the extension direction is parallel to the axial direction of the positioning column; the bearing disc is clamped between the first limiting strip and the second limiting strip and can move. And a circumferential limiting structure and a radial limiting structure for the gear shifting hub are arranged on the bearing disc. The scheme has the beneficial effects that the absolute value measurement is changed into the relative value calculation, and the difficulty that the absolute value is difficult to measure is avoided, so that the detection efficiency is greatly improved on the premise of ensuring the detection precision.

Description

Technical Field

[0001] This utility model relates to the field of measuring equipment, specifically a measuring tool for measuring the bottom diameter of a gear shift hub milling groove. Background Technology

[0002] The shift hub is a core component of a DCT transmission. During gear shifting, the shift hub, through its specific groove profile, interacts with other components in the transmission to achieve the switching between different gears. Specifically, when the shift lever position changes, key components in the shift mechanism, such as the clutch, brake, and one-way overrunning clutch, precisely control the movement of elements in the planetary gear system to change the transmission ratio, thereby completing the gear shift. In this process, the groove profile of the shift hub plays a crucial role, ensuring the accuracy and smoothness of gear shifting. Therefore, the profile of the shift hub needs to be strictly controlled during manufacturing to ensure it meets design requirements. Ideally, the bottom of all grooves in the shift hub lies on an inner cylindrical surface of a standard diameter; therefore, controlling the diameter of the groove bottom is both a key focus and a challenge. This is due to the distribution characteristics of the shift hub grooves. According to the design, there are four grooves distributed on the surface of the shift hub in a near-circular but not simple 360° arrangement. The grooves often exhibit broken lines in their direction, and the directions of adjacent grooves also influence each other. Therefore, it is difficult to guarantee that any point at the bottom of any groove is also at the bottom of the groove at a 180° angle. This makes it impossible to effectively measure the diameter using general-purpose measuring tools (micrometers or calipers). Theoretically, vernier calipers could be used to measure the depth from the outer cylindrical surface of the shift hub to the bottom of the groove for conversion. However, the outer contour of the shift hub is approximately cylindrical, and both the inner and outer cylindrical surfaces are arc surfaces. Measuring the depth at the bottom of the groove would introduce significant errors, and accuracy could not be guaranteed.

[0003] Chinese patent document CN111156872A, published on May 15, 2020, discloses a "Three-coordinate measuring fixture and method for automotive dual-clutch shift hub." The applicant describes a solution comprising a base, a fixed bracket and a movable bracket mounted opposite each other on the base. The fixed bracket is fixedly connected to the base, and the movable bracket is slidably connected to the base. The movable bracket is connected to a pushing mechanism. Both the fixed bracket and the movable bracket have V-shaped fixing blocks at their top ends, and a limit block is also provided at the rear of the V-shaped fixing blocks on the fixed bracket. As disclosed in this solution, the use of a three-coordinate dial indicator and method results in low measurement efficiency, limiting its application to random sampling and preventing its use in full inspection. Summary of the Invention

[0004] Based on the above problems, this utility model provides a measuring tool for measuring the bottom diameter of the milling groove of a gear shift hub. It changes the measurement of absolute values ​​to the calculation of relative values, bypassing the difficulty of measuring absolute values, thereby greatly improving the detection efficiency while ensuring detection accuracy.

[0005] To achieve the purpose of this invention, the present invention adopts the following technical solution: a measuring tool for measuring the bottom diameter of a gear shift hub milling groove, comprising:

[0006] The shift hub, with its end shaft pointing downwards, is placed on the bearing plate.

[0007] The positioning post extends radially along the shift hub, and the contact end of the positioning post abuts against the bottom of the positioning milled groove of the shift hub;

[0008] The dial indicator has its probe extending parallel to the positioning post, and the probe head abuts against the bottom of the milled groove of the shift hub.

[0009] Preferably, the bearing plate is movable along the axial direction of the positioning column.

[0010] Preferably, it also includes a first limiting strip and a second limiting strip; the first limiting strip and the second limiting strip are fixed in parallel, and the pressing extension direction is parallel to the axial direction of the positioning column; the bearing plate is movable and clamped between the first limiting strip and the second limiting strip.

[0011] Preferably, the bearing plate is provided with a circumferential limiting structure and a radial limiting structure for the shift hub.

[0012] Preferably, the circumferential limiting structure includes a positioning hole located at the center of the bearing plate, the shape and size of which are adapted to the shape and size of the end shaft.

[0013] Preferably, the radial limiting structure includes a limiting ring protruding from the upper surface of the bearing plate, the diameter of which is adapted to the outer diameter of the shift hub.

[0014] Preferably, it also includes a dial indicator mounting base, with the positioning column fixed on the dial indicator mounting base; during measurement, the bearing plate moves to its limit along the axial direction of the positioning column, and a gap is provided between the bearing plate and the dial indicator mounting base.

[0015] Preferably, the dial indicator is fixed on the dial indicator mounting bracket.

[0016] Preferably, the positioning column and / or dial indicator are height-adjustable on the dial indicator mounting base.

[0017] As a preferred embodiment, the fixture base plate is also included; the first limit bar, the second limit bar, and the dial indicator fixing seat are all fixed on the fixture base plate.

[0018] The beneficial effect of this solution is that by changing the measurement of absolute values ​​to the calculation of relative values, the difficulty of measuring absolute values ​​is bypassed, thereby greatly improving the detection efficiency while ensuring detection accuracy. Attached Figure Description

[0019] Figure 1 This is the left view of this utility model;

[0020] Figure 2 This is a top view of the present invention;

[0021] Figure 3 This is a perspective view of the present invention;

[0022] Figure 4 yes Figure 2 AA partial sectional view;

[0023] Figure 5 This is an axial sectional view of the gear shift hub;

[0024] Figure 6 This is a partial sectional view of the present invention in use, with the dotted line indicating the shift hub.

[0025] The components include: 1. Inspection base plate, 21. First limiting strip, 22. Second limiting strip, 3. Bearing plate, 31. Positioning hole, 32. Limiting ring, 4. Dial indicator fixing seat, 5. Positioning column, 6. Dial indicator, 61. Measuring rod, G. Shift hub, G0. Positioning milling groove, G1. Inspection milling groove, G2. End shaft. Detailed Implementation

[0026] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0027] Example 1

[0028] Example 1 details a measuring tool specifically designed for the bottom diameter of the milling groove in a gear shift hub. This tool is widely used in a transmission manufacturing company and plays a key role in improving product quality and production efficiency.

[0029] Before delving into this embodiment, let's first gain a basic understanding of the shift hub G. For example... Figure 5 Clearly illustrated, the shift hub G, as a core component of the DCT (dual-clutch) transmission, has an overall cylindrical design with a smooth outer cylindrical surface. Four milled grooves are meticulously milled onto this outer cylindrical surface using precision milling technology. These grooves cleverly encircle, bend, and merge on the outer cylindrical surface, forming a complex geometric shape. Crucially, despite the varied shapes of the milled grooves, the bottom of each groove must precisely lie on a pre-designed inner cylindrical surface. This inner cylindrical surface maintains a precise coaxial relationship with the outer cylindrical surface, ensuring the stable operation of the shift hub G within the transmission.

[0030] Furthermore, the design of the shift hub G also considers ease of installation and stability. An end shaft G2 protrudes axially from one end face of its outer cylinder. This design not only enhances the structural strength of the shift hub G but also facilitates subsequent precise positioning and installation. The cross-sectional shape of the end shaft G2 adopts a non-circular design; in this example, it is a common superior arc shape. This design satisfies functional requirements while also possessing a certain aesthetic appeal. Of course, those skilled in the art can flexibly adjust the cross-sectional shape and dimensions of the end shaft G2 according to actual design needs to achieve the best performance.

[0031] Thanks to advanced CNC machining technology, the machining accuracy of the outer cylindrical surface of the shift hub G has been significantly improved, ensuring it meets stringent manufacturing requirements. In this process, not only is the overall smoothness and dimensional accuracy of the outer cylindrical surface guaranteed, but the groove shape and dimensions of each milled groove also strictly conform to design requirements without deviation. However, while pursuing overall accuracy, special attention must be paid to a crucial detail: ensuring the consistency of the depth of each milled groove. This means that each milled groove must precisely fall on an inner cylindrical surface of a preset diameter to guarantee the performance and reliability of the shift hub G in practical applications.

[0032] As detailed earlier, the unique arrangement of the milled grooves on the outer cylindrical surface makes directly measuring the diameter of the inner cylindrical surface exceptionally difficult. This arrangement not only increases the complexity of the measurement but also can lead to inaccurate results due to minute errors during the measurement process. Therefore, while ensuring the machining accuracy of the outer cylindrical surface and the milled grooves, effectively verifying the consistency of the depth of each milled groove becomes a problem that requires careful consideration and resolution.

[0033] See Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown in the figure, this embodiment details the structure and application of a gauge for measuring the bottom diameter of a gear shift hub milling groove. This gauge mainly includes core components such as a bearing plate 3, a positioning pin 5, and a dial indicator 6.

[0034] The support plate 3 serves as the base of the entire measurement system and is specifically designed to stably support the shift hub G. In actual operation, the end shaft G2 of the shift hub G must be placed downwards, and appropriate adjustments must be made to ensure that the shift hub G is vertically and stably seated on the support plate 3. The specific shape and size of the support plate 3 can be customized according to actual measurement needs. Those skilled in the art can flexibly design and manufacture a support plate 3 that meets the requirements based on the specifications and measurement accuracy requirements of the shift hub G.

[0035] The locating pin 5 plays a crucial role in precise positioning. It is typically a slender, wear-resistant metal rod whose axis strictly follows the axis of the shift hub G. The base of the locating pin 5 is firmly fixed to the appropriate position on the fixture, while its contact point precisely contacts the bottom of a pre-defined milled groove on the shift hub G—the locating groove G0. The material and machining precision of the locating pin 5 must also be customized according to the measurement requirements to ensure measurement accuracy. Furthermore, technicians can choose functionally similar components as substitutes for the locating pin 5 when necessary.

[0036] The dial indicator 6 is a crucial tool in the measurement process. It adopts a standard dial indicator design, suitable for both mechanical and digital displays, but its key feature is the telescopic function of its probe. The probe 61 of the dial indicator 6 is carefully fixed in a position parallel to the axis of the positioning column 5 to ensure measurement accuracy. During measurement, the probe of the dial indicator 6 will contact the bottom of another pre-set milled groove on the shift hub G—the detection milled groove G1. To ensure measurement synchronization, the fixed position of the dial indicator 6 needs to be pre-adjusted so that when the contact end of the positioning column 5 touches the bottom of the positioning milled groove G0, the probe of the dial indicator 6 can also precisely touch the bottom of the detection milled groove G1.

[0037] In practical applications, when using this gear shift hub milling groove bottom diameter measuring fixture to inspect batches of gear shift hubs, a specific procedure must be followed: First, a standard part must be measured to obtain a baseline value; then, each product to be tested is measured individually, and the measurement values ​​for each product are recorded; finally, by comparing the difference between the measured values ​​and the baseline value, it can be determined whether the product meets the tolerance requirements, thereby confirming its qualification. This procedure not only ensures the accuracy of the measurement but also greatly improves the inspection efficiency. Details are as follows:

[0038] 1. Place the standard shift hub G smoothly on the bearing plate 3 with the end shaft G2 facing downward and the axial direction vertical;

[0039] 2. Move the bearing plate 3 along the axial direction of the positioning post 5 so that the contact end of the positioning post 5 touches the bottom of the positioning milling groove G0;

[0040] 3. At this time, the probe of dial indicator 6 also touches the bottom of the groove in the milling groove G1;

[0041] 4. Use the reading on dial indicator 6 as the baseline value;

[0042] 5. Return the bearing plate 3, remove the standard shift hub G, replace it with the shift hub G to be moved, and repeat steps 1, 2, and 3.

[0043] 6. Read the reading on dial indicator 6 as the measured value;

[0044] 7. Compare the difference between the measured value and the benchmark value to see if it meets the standard.

[0045] This embodiment is the basic version of this solution. Subsequent embodiments will be further optimized based on this embodiment.

[0046] Example 2

[0047] Example 2 demonstrates an improved and optimized gauge for measuring the bottom diameter of milled grooves in a gear shift hub, based on Example 1. The specific improvements are as follows: Two key components, a first limiting strip 21 and a second limiting strip 22, are cleverly added to the original structure. These two limiting strips extend parallel to each other and are aligned with the axial direction of the positioning post 5, ensuring structural stability and consistency. The support plate 3 is cleverly clamped between the first limiting strip 21 and the second limiting strip 22, forming a stable clamping structure. Simultaneously, the support plate 3 can move smoothly along the axial direction of the positioning post 5 to meet measurement requirements.

[0048] To achieve this function, the sides of the carrier plate 3 that contact the first limiting strip 21 and the second limiting strip 22 are specially designed as corresponding straight edges. This design not only improves the accuracy of the contact surface, but more importantly, it can easily and effectively restrict the movement direction of the carrier plate 3, ensuring that it can only move along a predetermined path. In this way, the carrier plate 3 will not deviate when measuring different shift hubs G, thus guaranteeing the accuracy and reliability of the measurement results.

[0049] Of course, this solution is not limited to the specific implementation described above, and other alternative solutions are also possible. For example, two slide rails can be used to replace the first limiting strip 21 and the second limiting strip 22, and the carrier plate 3 can be designed to slide only on these two slide rails. Such a design can also achieve the purpose of limiting the movement direction of the carrier plate 3, and may have greater flexibility and adaptability. Those skilled in the art can flexibly design the required limiting and moving structure according to the actual application scenario and needs to meet different measurement requirements.

[0050] Same as Example 1.

[0051] Example 3

[0052] Example 3 is another measuring fixture for the bottom diameter of the milled groove in the shift hub. The improvements in this example mainly lie in the design and optimization of the support plate 3: the center of the support plate 3 is carefully designed as a small hole, namely the positioning hole 31, a crucial design. The position of the positioning hole 31 is precisely calculated, and its size and cross-sectional shape perfectly match and fit the end shaft G2 of the shift hub G. When the shift hub G is accurately installed, its end shaft G2 can be securely inserted into the positioning hole 31. This effectively restricts the circumferential rotation of the shift hub G, ensuring its stability and reliability during operation.

[0053] Furthermore, the surface of the support plate 3 is cleverly raised upwards, forming a limiting ring 32. The dimensions of this limiting ring 32 are also carefully designed, perfectly matching the outer diameter of the shift hub G, creating a just-right containment space. This design allows the shift hub G to be stably placed within this space, effectively constrained both axially and radially, further enhancing overall stability and safety.

[0054] Same as Example 2.

[0055] Example 4

[0056] In another improved design of the gauge for measuring the bottom diameter of the milled groove in embodiment 4, two major components, the gauge base plate 1 and the dial indicator mounting base 4, are added to further improve the accuracy and stability of the measurement. The gauge base plate 1 is carefully designed as a stable and reliable flat plate structure, which not only provides a solid support foundation but also ensures that all components installed on it maintain a high degree of positional accuracy. The first limiting strip 21 and the second limiting strip 22, these two key limiting structures, as well as the newly added dial indicator mounting base 4, are all firmly fixed in the predetermined positions on the gauge base plate 1. This layout is both compact and reasonable.

[0057] In this example, the dial indicator mounting base 4 is presented as a vertically positioned column, firmly standing on the fixture base plate 1, providing a precise positioning point for subsequent measurements. Of particular note is the cleverly designed positioning pin 5, which is positioned slightly below the center of the dial indicator mounting base 4. This design facilitates precise alignment of the shift hub during measurement. The dial indicator 6, as the core component for measurement, is precisely mounted on the upper part of the dial indicator mounting base 4, ensuring accurate capture of the diameter data at the bottom of the groove during measurement.

[0058] Furthermore, to ensure that the accuracy of the measurement is not affected by any external factors, the dial indicator mounting base 4 and the carrier plate 3 are carefully designed to maintain a certain gap at all times. The existence of this gap is crucial, as it effectively prevents any unnecessary contact between the two, thereby avoiding the negative impact on the measurement progress caused by friction or interference, and ensuring the smoothness and accuracy of the entire measurement process.

[0059] This embodiment is a more complete preferred embodiment of the proposed solution. For the final structure, please refer to [link / reference]. Figure 4 As shown, the detection status can be found in [reference needed]. Figure 6 As shown. Further optimization is possible, for example, by making the heights of the positioning column 5 and the dial indicator 6 adjustable to meet the testing requirements of different models of shift hub G.

[0060] The beneficial effect of this solution is that by changing the measurement of absolute values ​​to the calculation of relative values, the difficulty of measuring absolute values ​​is bypassed, thereby greatly improving the detection efficiency while ensuring detection accuracy.

Claims

1. 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The shift drum groove bottom diameter measuring gauge according to claim 1, wherein, ​ 3. The shift drum groove bottom diameter measuring gauge of claim 2, wherein, ​ 4. The shift hub groove bottom diameter measuring gauge according to claim 1 or 2 or 3, characterized in that, ​ 5. The shift drum groove bottom diameter measuring gauge of claim 4 wherein, ​ 6. A shift drum groove bottom diameter measuring gauge as set forth in claim 4, wherein, ​ 7. A shift drum groove bottom diameter measuring gauge according to claim 1 or 2 or 3, characterized in that, ​ 8. The shift drum groove bottom diameter measuring gauge of claim 7, wherein, ​ 9. A shift drum groove bottom diameter measuring gauge as set forth in claim 8, wherein, ​ 10. The shift drum groove bottom diameter measuring gauge of claim 7, wherein, ​

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