Detection device and method for accurate grinding shaft of cross shaft

Abstract

The invention relates to the technical field of universal joint cross shafts, in particular to a cross shaft accurate grinding shaft detection device and method. The detection device for the accurate grinding shaft of the cross shaft comprises a lever unit, a positioning unit and a detection unit. The lever unit comprises a fixed seat, a swing rod, an abutting part and a measuring part; the oscillating rod and the fixed seat are rotationally connected around a first axis; the abutting part comprises a first ejector pin; the positioning unit comprises a positioning sleeve; the axis of the positioning sleeve is perpendicular to the first axis; an accurate grinding shaft for placing the cross shaft is arranged in the positioning sleeve; the abutting part is positioned on one axial side of the positioning sleeve; the top end surface of the positioning sleeve is a positioning reference surface; the positioning reference surface is used for abutting against a step surface at the root of the fine grinding shaft; the first ejector pin is used for abutting against the fine grinding shaft. The detection unit is used for detecting the height position of the measuring part. In this way, the problem that the detection precision of the axial size and the end face perpendicularity of the cross shaft accurate grinding shaft is insufficient is solved.

Description

Technical Field

[0001] This invention relates to the field of universal joint cross shaft technology, and more specifically, to a cross shaft precision grinding shaft testing device and method. Background Technology

[0002] Universal joints are mechanical components that enable the transmission of power between rotating shafts at varying angles. They are used in locations where the direction of the drive shaft needs to be changed and are a key component of the universal joint transmission device in automotive drive systems. Universal joints can be classified according to their speed characteristics into non-constant velocity universal joints, quasi-constant velocity universal joints, and constant velocity universal joints. A common type of non-constant velocity universal joint is the cross-shaft type. Cross-shaft universal joints mainly consist of a cross shaft, universal joint forks, and needle roller bearings, and are characterized by their simple structure and high reliability. The cross shaft is cross-shaped with four journals that are perpendicular to each other in pairs, providing the foundation for the universal joint's variable angle power transmission. Its assembly principle involves inserting the four journals into the two universal joint fork holes pre-installed with needle roller bearings, and using retaining rings for positioning to achieve flexible swinging and torque transmission. The journals of the cross shaft usually require precision grinding to ensure a precise fit between the journals and the needle roller bearings, reduce friction and wear, improve load-bearing capacity, and thus ensure stable operation and extend the service life of the universal joint.

[0003] After precision grinding, the axial dimensions and end face perpendicularity of the cross shaft need to be inspected. Improving the inspection accuracy is a pressing issue. Summary of the Invention

[0004] To address the problem of insufficient detection accuracy of axial dimensions and end face perpendicularity of precision-ground cross shafts, this invention provides a detection device and method for precision-ground cross shafts.

[0005] In a first aspect, the present invention provides a cross-shaped precision-ground shaft inspection device, which includes:

[0006] A lever unit includes a fixed base, a swing rod, a contact portion, and a measuring portion. The swing rod is rotatably connected to the fixed base about a first axis. The contact portion is connected to one end of the swing rod, and the measuring portion is connected to the other end of the swing rod. The first axis is located between the contact portion and the measuring portion and is horizontally oriented. The contact portion includes a first pin, which is perpendicular to the first axis and perpendicular to the length direction of the swing rod.

[0007] A positioning unit includes a positioning sleeve; the axis of the positioning sleeve is perpendicular to the first axis; a fine grinding shaft for placing a cross shaft is placed inside the positioning sleeve; the abutment portion is located on one side of the axial direction of the positioning sleeve; the top end face of the positioning sleeve is a positioning reference surface; the positioning reference surface is used to abut against the stepped surface at the root of the fine grinding shaft; a first ejector pin is used to abut against the fine grinding shaft, the distance between the first ejector pin and the first axis is a first distance; the distance between the first axis and the axis of the positioning sleeve is a second distance; the first distance and the second distance have a difference; when the first ejector pin abuts against the fine grinding shaft, the angle between the first ejector pin and the axis of the positioning sleeve is less than a threshold value;

[0008] A detection unit is used to detect the height position of the measuring part.

[0009] In some embodiments, the abutting portion further includes a second ejector pin; the first ejector pin and the second ejector pin are parallel; the height of the first ejector pin is greater than the height of the second ejector pin; the first ejector pin and the second ejector pin have a first height difference; the distance between the second ejector pin and the first axis is a third distance; the third distance has a difference from the second distance; the third distance has a difference from the first distance.

[0010] In some embodiments, the first spacing, the second spacing, and the third spacing decrease sequentially.

[0011] In some embodiments, the distance between the abutting portion and the first axis is adjustable.

[0012] In some embodiments, the positioning unit further includes an adjustment frame; the positioning sleeve is detachably connected to the adjustment frame.

[0013] In some embodiments, the measuring part has a measuring surface; the measuring surface is a convex arc shape; the direction of the convexity of the measuring surface is parallel to the axis of the positioning sleeve; the detection unit abuts against the measuring surface.

[0014] Secondly, the present invention provides a method for detecting a finely ground cross shaft, applicable to the finely ground cross shaft detection device described in any embodiment of the first aspect. The method for detecting a finely ground cross shaft includes:

[0015] Place the fine-grinding shaft of the cross shaft into the positioning sleeve so that the stepped surface at the root of the fine-grinding shaft abuts against the positioning reference surface, and the bottom end face of the fine-grinding shaft abuts against the abutting part;

[0016] Obtain the first height data of the measuring unit;

[0017] Rotate the cross shaft around the axis of the grinding shaft to a preset angle;

[0018] The process of returning to the step of acquiring the first height data of the measuring unit is repeated until multiple sets of the first height data are obtained.

[0019] The first detection result is determined based on multiple sets of the first height data; the first detection result includes the axial dimension and end face perpendicularity of the precision-ground shaft.

[0020] In some embodiments, the abutting portion further includes a second ejector pin; the first ejector pin and the second ejector pin are parallel; the height of the first ejector pin is greater than the height of the second ejector pin; the first ejector pin and the second ejector pin have a first height difference; the distance between the second ejector pin and the first axis is a third distance; the third distance has a difference from the second distance; the third distance has a difference from the first distance.

[0021] The step of determining the first detection result based on multiple sets of the first height data includes:

[0022] Calculate the second height data of the abutment portion corresponding to each set of the first height data based on multiple sets of the first height data;

[0023] Determine the maximum difference between any two of the second altitude data;

[0024] Based on the fact that the maximum difference is less than the first height difference, the first test result is determined to be qualified, and the median or average value among multiple sets of the second height data is determined as the axial dimension of the fine grinding shaft;

[0025] Based on the fact that the maximum difference is greater than or equal to the first height difference, the first test result is determined to be unqualified.

[0026] In some embodiments, the distance between the abutting portion and the first axis is adjustable;

[0027] The cross-shaft precision grinding shaft inspection method also includes:

[0028] Based on the first test result being qualified, the distance between the abutting part and the first axis is adjusted;

[0029] Obtain the third height data of the measuring unit;

[0030] Rotate the cross shaft around the axis of the grinding shaft to a preset angle;

[0031] The process of returning to the step of acquiring the third height data of the measuring unit is repeated until multiple sets of the third height data are obtained.

[0032] The second detection result is determined based on multiple sets of the third height data; the second detection result includes the axial dimension and end face perpendicularity of the precision-ground shaft.

[0033] In some embodiments, determining the second detection result based on multiple sets of the third altitude data includes:

[0034] Calculate the fourth height data of the abutment portion corresponding to each set of the third height data based on multiple sets of the third height data;

[0035] Determine the second maximum difference between any two of the fourth altitude data;

[0036] Based on the fact that the second maximum difference is less than the first height difference, the second test result is determined to be qualified, and the median or average value among multiple sets of the second height data is determined as the axial dimension of the fine grinding shaft;

[0037] Based on the fact that the second maximum difference is greater than or equal to the first height difference, the second test result is determined to be unqualified.

[0038] To address the insufficient accuracy in detecting the axial dimensions and end face perpendicularity of precision-ground cross shafts, this invention offers the following advantages:

[0039] By using the positioning sleeve as a positioning reference, the axial dimension of the fine grinding shaft is detected by the swing amplitude of the lever unit. Multiple sets of data can be obtained by rotating the fine grinding shaft at various angles, thus determining the reliability of the axial dimension. Since the first ejector pin abuts at an eccentric position, the perpendicularity of the end face can be detected by rotating the fine grinding shaft, resulting in high detection efficiency. The cross shaft is positioned on the positioning reference surface by gravity, making the process simple and reliable. Attached Figure Description

[0040] Figure 1 A schematic diagram of the structure of a cross-shaped precision grinding shaft inspection device according to one embodiment is shown;

[0041] Figure 2 A schematic diagram of the structure of a cross-shaped precision grinding shaft inspection device according to one embodiment is shown;

[0042] Figure 3 A flowchart illustrating the cross-shaft precision grinding shaft inspection method in Embodiment 2 is shown.

[0043] Reference numerals: 10 Cross-shaped precision grinding shaft detection device; 11 Lever unit; 111 Fixed base; 112 Swing rod; 113 Abutment part; 1131 First ejector pin; 1132 Second ejector pin; 114 Measuring part; 1141 Measuring surface; 115 First axis; 12 Positioning unit; 121 Positioning sleeve; 1211 Positioning reference surface; 122 Adjusting frame; 13 Detection unit; 20 Cross-shaped shaft; 21 Precision grinding shaft; 211 Step surface. Detailed Implementation

[0044] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present disclosure, and are not intended to imply any limitation on the scope of the disclosure.

[0045] As used herein, the term "comprising" and its variations are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "at least partially based on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment". The term "another embodiment" is to be interpreted as "at least one other embodiment". The terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments and are not intended to limit the indicated devices, elements, or components to having a specific orientation or being constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientations or positional relationships; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances. In addition, the terms "installed", "set up", "equipped with", "connected", and "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. Furthermore, the terms "first," "second," etc., are mainly used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0046] Universal joints are mechanical components that enable the transmission of power between rotating shafts at varying angles. The cross-shaft type 20 non-constant velocity universal joint is a type of universal joint, mainly composed of core components such as the cross-shaft 20, the universal joint fork, and needle roller bearings. It features a simple structure and high reliability. The cross-shaft 20 is cross-shaped with four journals that are perpendicular to each other in pairs. The journals of the cross-shaft 20 typically require precision grinding to ensure a precise fit between the journals and the needle roller bearings, reduce friction and wear, and improve load-bearing capacity, thereby ensuring stable operation of the universal joint and extending its service life. After precision grinding of the cross-shaft 20 shaft 21, the axial dimensions and end face perpendicularity need to be inspected. Improving the inspection accuracy is a problem that urgently needs to be solved.

[0047] To address the problem of insufficient detection accuracy of the axial dimension and end face perpendicularity of the precision-ground shaft 21 of the cross shaft 20, this invention provides a cross shaft precision-ground shaft detection device 10 and method.

[0048] Example 1:

[0049] This embodiment provides a cross-shaft precision grinding shaft inspection device 10, which is used to inspect the axial dimension and end face perpendicularity of the cross-shaft 20 precision grinding shaft 21. Figure 1 As shown, the cross shaft 20 includes a fine-grinding shaft 21, and the fine-grinding shaft 21 includes a stepped surface 211; a cross shaft fine-grinding shaft detection device 10 includes a lever unit 11, a positioning unit 12, a detection unit 13, and a base, wherein the lever unit 11, the positioning unit 12, and the detection unit 13 are all along the... Figure 1 The lever unit 11 is arranged vertically and connected to the base. It includes a fixed base 111, a swing rod 112, a contact part 113, and a measuring part 114. The swing rod 112 is rotatably connected to the fixed base 111 about a first axis 115. The length direction of the fixed base 111 is parallel to the direction of gravity. During the preparation stage of the test, the length direction of the swing rod 112 can be parallel to the horizontal direction. The contact part 113 is connected to one end of the swing rod 112, and the measuring part 114 is connected to the other end of the swing rod 112. The first axis 115 is located between the contact part 113 and the measuring part 114. The first axis 115 is horizontally arranged, as shown in the diagram. Figure 1 As shown, the first axis 115 is perpendicular to the length direction of the fixed base 111, and the first axis 115 is perpendicular to the length direction of the swing rod 112; the abutment part 113 includes a first ejector pin 1131; the first ejector pin 1131 is perpendicular to the first axis 115; the first ejector pin 1131 is perpendicular to the length direction of the swing rod 112; in this way, when the first ejector pin 1131 is subjected to an external force and rotates around the first axis 115, the measuring part 114 can be driven to rotate through the swing rod 112.

[0050] The positioning unit 12 includes a positioning sleeve 121; the axis of the positioning sleeve 121 is perpendicular to the first axis 115; the positioning sleeve 121 is used to place the fine grinding shaft 21 of the cross shaft 20; the abutment part 113 is located on one side of the axial direction of the positioning sleeve 121; the top end face of the positioning sleeve 121 is the positioning reference surface 1211; the positioning reference surface 1211 is used to abut against the stepped surface 211 at the root of the fine grinding shaft 21; in this way, the fine grinding shaft 21 of the cross shaft 20 can be inserted into the positioning sleeve 121 along the direction of gravity, and then abut against the stepped surface 211 through the positioning reference surface 1211, thereby supporting the cross shaft 20 on the positioning sleeve 121. The first ejector pin 1131 is used to abut against the fine grinding shaft 21. The distance between the first ejector pin 1131 and the first axis 115 is the first distance; the distance between the first axis 115 and the axis of the positioning sleeve 121 is the second distance; the first distance and the second distance have a difference; that is, when the first ejector pin 1131 abuts against the end face of the fine grinding shaft 21, the first ejector pin 1131 is deviated from the axis of the positioning sleeve 121. Since the rocker arm unit is fixedly set, and the relative position of the positioning sleeve 121 and the rocker arm unit is fixed, when the first ejector pin 1131 abuts against the end face of the fine grinding shaft 21 and swings around the first axis 115, the first ejector pin 1131 will slide and rub against the end face of the fine grinding shaft 21 along the length of the rocker arm 112. When the first ejector pin 1131 is in contact with the fine grinding shaft 21, the angle between the first ejector pin 1131 and the axis of the positioning sleeve 121 is less than a threshold value. This can prevent the axial dimension of the fine grinding shaft 21 being too long, which would cause the first ejector pin 1131 and the end face of the fine grinding shaft 21 to have an excessively long sliding friction distance, thereby reducing the wear of the first ejector pin 1131 and the end face of the fine grinding shaft 21.

[0051] The detection unit 13 is used to detect the height position of the measuring unit 114. In this way, the height difference can be measured by the detection unit 13 after the measuring unit 114 rotates around the first axis 115 and changes in height.

[0052] By using the positioning sleeve 121 as the positioning reference, the axial dimension of the fine grinding shaft 21 is detected by utilizing the swing amplitude of the lever unit 11 and the detection unit 13. By rotating the fine grinding shaft 21 at multiple angles, multiple sets of data can be obtained, thereby determining the reliability of the axial dimension. Since the first ejector pin 1131 abuts at an eccentric position, the perpendicularity of the end face can be detected by rotating the fine grinding shaft 21, resulting in high detection efficiency. Furthermore, the setup of using the gravity of the cross shaft 20 to position the fine grinding shaft 21 on the positioning reference surface 1211 is simple and reliable.

[0053] In this embodiment, a cross-shaped precision grinding shaft detection device 10 further includes a protective screw, the protective screw being flush with the base along the... Figure 1The vertical connection is shown. A tip is provided at the top of the protective screw, the height of which is close to and lower than the side of the lever unit 11 closest to the measuring section 114. There is an overlap between the side of the lever unit 11 where the measuring section 114 is located and the projection of the protective screw in the vertical direction. Thus, when the side of the lever unit 11 where the measuring section 114 is located abuts against the tip, after the cross shaft 20 is inserted into the positioning sleeve 121, the first ejector pin 1131 is pushed by the cross shaft 20 and rotates around the first axis 115, thereby causing the measuring section 114 to rotate around the first axis 115. Because the height of the tip is close to and lower than the side of the lever unit 11 where the measuring section 114 is located, the angle of rotation of the measuring section 114 around the first axis 115 is small. This reduces damage to the detection unit 13 when the measuring section 114 abuts against the detection unit 13. Furthermore, the height of the protective screw is adjustable, thus adapting to the needs of lever units 11 of different lengths and achieving the protection of the detection unit 13.

[0054] In some embodiments, the detection unit 13 can be a dial indicator, a micrometer, or a distance sensor. When the detection unit 13 is set as a distance sensor, a torsion spring can be provided at the first axis 115 to lift the compressed abutment portion 113, or a compression spring can be installed below the abutment portion 113, which can also serve to lift the abutment portion 113.

[0055] In other embodiments, the first ejector pin 1131 is deviated from the axis of the positioning sleeve 121. This can be because the first ejector pin 1131 is deviated from the axis of the positioning sleeve 121 along the length direction of the swing rod 112, or the first ejector pin 1131 is deviated from the axis of the positioning sleeve 121 along the direction of the first axis 115 on the swing rod 112.

[0056] Furthermore, such as Figure 2As shown, the abutment portion 113 also includes a second ejector pin 1132; the first ejector pin 1131 and the second ejector pin 1132 are parallel; the height of the first ejector pin 1131 is greater than the height of the second ejector pin 1132; the first ejector pin 1131 and the second ejector pin 1132 have a first height difference; the distance between the second ejector pin 1132 and the first axis 115 is a third distance; the third distance has a difference from the second distance; the third distance has a difference from the first distance. That is, both the first ejector pin 1131 and the second ejector pin 1132 are offset from the axis of the positioning sleeve 121 and have different distances from the first axis 115. In this way, when the perpendicularity of the end face of the fine grinding shaft 21 being tested deviates significantly from the tolerance range of the design size, the lower height of the second ejector pin 1132 can be used to abut against the end face of the fine grinding shaft 21. This reduces the swing amplitude of the abutment part 113 at the beginning of the test. At this time, the test can be completed by the second ejector pin 1132 rubbing against the end face of the fine grinding shaft 21 over a short distance along the length of the swing rod 112. This avoids the situation where only the first ejector pin 1131 can be used for long-distance friction, thus extending the service life of the abutment part 113.

[0057] Furthermore, such as Figure 2 As shown, the first, second, and third spacings decrease sequentially. Since the end face perpendicularity of the precision-ground shaft 21 of the cross shaft 20 processed in the same batch is usually more qualified than unqualified, this setting allows the frequently used first ejector pin 1131 to be positioned further away from the first axis 115 when inspecting precision-ground shafts 21 with qualified end face perpendicularity. This increases the swing radius of the first ejector pin 1131, thereby reducing the horizontal swing angle of the first ejector pin 1131 at the same descent height, thus reducing the horizontal displacement and consequently reducing the wear of the frequently used first ejector pin 1131.

[0058] Furthermore, such as Figure 1 As shown, the distance between the abutment portion 113 and the first axis 115 is adjustable. Since the height difference of the first ejector pin 1131 swinging downwards under pressure remains constant, reducing the distance between the abutment portion 113 and the first axis 115 increases the height difference of the measuring portion 114 rotating around the first axis 115. This enhances the amplification effect of the lever unit 11 on the axial dimension detection of the fine grinding shaft 21.

[0059] Furthermore, such as Figure 1 As shown, the positioning unit 12 also includes an adjustment frame 122; the positioning sleeve 121 is detachably connected to the adjustment frame 122. In this way, by adjusting the height of the adjustment frame 122 and replacing different positioning sleeves 121, the axial dimension and end face perpendicularity of the precision-ground shaft 21 of the cross shaft 20 of different sizes can be detected, thereby improving the applicability of the cross shaft precision-ground shaft detection device 10.

[0060] Furthermore, such as Figure 1 As shown, the measuring unit 114 has a measuring surface 1141; the measuring surface 1141 is a convex arc shape; the direction of the convexity of the measuring surface 1141 is parallel to the axis of the positioning sleeve 121; the detection unit 13 abuts against the measuring surface 1141. This makes the contact between the detection unit 13 and the measuring surface 1141 a point contact, thereby improving the measurement accuracy.

[0061] Furthermore, such as Figure 3 As shown, a method for detecting the precision-ground shaft 21 of the cross shaft 20 includes steps S10-S50, which are described in detail below:

[0062] Step S10: Place the fine grinding shaft 21 of the cross shaft 20 into the positioning sleeve 121 so that the stepped surface 211 at the root of the fine grinding shaft 21 abuts against the positioning reference surface 1211, and the bottom end face of the fine grinding shaft 21 abuts against the abutting part 113.

[0063] Step S20: Obtain the first height data of the measuring unit 114;

[0064] Step S30: Rotate the cross shaft 20 around the axis of the fine grinding shaft 21 to a preset angle;

[0065] Step S40: Return to the step of acquiring the first height data of the measuring unit 114 and repeat until multiple sets of first height data are obtained;

[0066] Step S50: Determine the first detection result based on multiple sets of first height data; the first detection result includes the axial dimension and end face perpendicularity of the precision-ground shaft 21.

[0067] This allows the axial dimension of the fine grinding shaft 21 to be detected by using the positioning sleeve 121 as a positioning reference and the swing amplitude of the lever unit 11. By rotating the fine grinding shaft 21 at multiple angles, multiple sets of data can be obtained, thereby determining the reliability of the axial dimension. Since the first ejector pin 1131 abuts at an eccentric position, the perpendicularity of the end face can be detected by rotating the fine grinding shaft 21, resulting in high detection efficiency.

[0068] Furthermore, such as Figure 2 As shown, the abutment portion 113 further includes a second ejector pin 1132; the first ejector pin 1131 and the second ejector pin 1132 are parallel; the height of the first ejector pin 1131 is greater than the height of the second ejector pin 1132; the first ejector pin 1131 and the second ejector pin 1132 have a first height difference; the distance between the second ejector pin 1132 and the first axis 115 is a third distance; the third distance has a difference from the second distance; the third distance has a difference from the first distance.

[0069] Step S50 includes steps S51-S54, which are explained in detail below:

[0070] Step S51: Calculate the second height data of the abutment part 113 corresponding to each set of first height data based on multiple sets of first height data; the second height data can be obtained by taking the average value after statistical processing of the first height data.

[0071] Step S52: Determine the maximum difference between any two second altitude data points;

[0072] Step S53: Based on the fact that the maximum difference is less than the first height difference, the first test result is determined to be qualified, and the median or average value among multiple sets of second height data is determined as the axial dimension of the precision grinding shaft 21;

[0073] Step S54: Based on the maximum difference being greater than or equal to the first height difference, determine that the first test result is unqualified. Thus, by setting the second ejector pin 1132 and comparing the maximum difference with the first height difference, it is possible to determine whether the first test result is qualified.

[0074] Furthermore, such as Figure 1 As shown, the distance between the abutment portion 113 and the first axis 115 is adjustable;

[0075] The method for detecting the precision-ground shaft 21 of the cross shaft 20 also includes step S60, which includes steps S61-S65, as detailed below:

[0076] Step S61: Based on the first test result being qualified, adjust the distance between the abutment part 113 and the first axis 115;

[0077] Step S62: Obtain the third height data of the measuring unit 114;

[0078] Step S63: Rotate the cross shaft 20 around the axis of the fine grinding shaft 21 to a preset angle;

[0079] Step S64: Return to the step of acquiring the third height data of the measuring unit 114 and repeat until multiple sets of third height data are obtained;

[0080] Step S65: Determine the second detection result based on multiple sets of third height data; the second detection result includes the axial dimension and end face perpendicularity of the fine-grinding shaft 21. This allows for the acquisition of multiple sets of third height data by changing the distance between the abutment part 113 and the axis of the fine-grinding shaft 21 before measurement, thus improving the reliability of the measurement data. Given that the height difference of the first ejector pin 1131 swinging downwards under pressure remains constant, reducing the distance between the abutment part 113 and the first axis 115 increases the height difference of the measuring part 114 rotating around the first axis 115. This strengthens the amplification effect of the lever unit 11 on the axial dimension detection of the fine-grinding shaft 21, making the measurement data closer to the true value.

[0081] Furthermore, step S65 includes steps S651-S654, which are explained in detail below:

[0082] Step S651: Calculate the fourth height data of the abutment part 113 corresponding to each set of third height data based on multiple sets of third height data;

[0083] Step S652: Determine the second maximum difference between any two fourth altitude data points;

[0084] Step S653: Based on the fact that the second maximum difference is less than the first height difference, the second test result is determined to be qualified, and the median or average value among multiple sets of second height data is determined as the axial dimension of the precision grinding shaft 21;

[0085] Step S654: Based on the fact that the second maximum difference is greater than or equal to the first height difference, the second test result is determined to be unqualified. In this way, by adjusting the distance between the abutment part 113 and the first axis 115, and comparing the second maximum difference with the first height difference, it can be determined whether the second test result is qualified.

[0086] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes can be made in form and detail without departing from the scope of this disclosure.

Claims

1. A cross-shaped precision-ground shaft testing device, characterized in that, The cross-shaft precision grinding shaft testing device includes: A lever unit includes a fixed base, a swing rod, a contact portion, and a measuring portion. The swing rod is rotatably connected to the fixed base about a first axis. The contact portion is connected to one end of the swing rod, and the measuring portion is connected to the other end of the swing rod. The first axis is located between the contact portion and the measuring portion and is horizontally oriented. The contact portion includes a first pin, which is perpendicular to the first axis and perpendicular to the length direction of the swing rod. A positioning unit includes a positioning sleeve; the axis of the positioning sleeve is perpendicular to the first axis; a fine grinding shaft for placing a cross shaft is placed inside the positioning sleeve; the abutment portion is located on one side of the axial direction of the positioning sleeve; the top end face of the positioning sleeve is a positioning reference surface; the positioning reference surface is used to abut against the stepped surface at the root of the fine grinding shaft; a first ejector pin is used to abut against the fine grinding shaft, the distance between the first ejector pin and the first axis is a first distance; the distance between the first axis and the axis of the positioning sleeve is a second distance; the first distance and the second distance have a difference; when the first ejector pin abuts against the fine grinding shaft, the angle between the first ejector pin and the axis of the positioning sleeve is less than a threshold value; A detection unit is used to detect the height position of the measuring part.

2. The cross-shaped precision grinding shaft testing device according to claim 1, characterized in that, The abutting part further includes a second ejector pin; the first ejector pin and the second ejector pin are parallel; the height of the first ejector pin is greater than the height of the second ejector pin; the first ejector pin and the second ejector pin have a first height difference; the distance between the second ejector pin and the first axis is a third distance; the third distance has a difference from the second distance; the third distance has a difference from the first distance.

3. The cross-shaped precision grinding shaft testing device according to claim 2, characterized in that, The first spacing, the second spacing, and the third spacing decrease sequentially.

4. The cross-shaped precision grinding shaft testing device according to claim 1, characterized in that, The distance between the abutting part and the first axis is adjustable.

5. The cross-shaped precision grinding shaft testing device according to claim 1, characterized in that, The positioning unit also includes an adjustment frame; the positioning sleeve is detachably connected to the adjustment frame.

6. The cross-shaped precision grinding shaft testing device according to claim 1, characterized in that, The measuring part has a measuring surface; the measuring surface is a raised arc shape; the direction of the raised measuring surface is parallel to the axis of the positioning sleeve; the detection unit abuts against the measuring surface.

7. A method for inspecting a finely ground cross shaft, applied to the finely ground cross shaft inspection device according to any one of claims 1-6, characterized in that, Place the fine-grinding shaft of the cross shaft into the positioning sleeve so that the stepped surface at the root of the fine-grinding shaft abuts against the positioning reference surface, and the bottom end face of the fine-grinding shaft abuts against the abutting part; Obtain the first height data of the measuring unit; Rotate the cross shaft around the axis of the grinding shaft to a preset angle; The process of returning to the step of acquiring the first height data of the measuring unit is repeated until multiple sets of the first height data are obtained. The first detection result is determined based on multiple sets of the first height data; the first detection result includes the axial dimension and end face perpendicularity of the precision-ground shaft.

8. The method for detecting a precision-ground cross shaft according to claim 7, characterized in that, The abutting part further includes a second ejector pin; the first ejector pin and the second ejector pin are parallel; the height of the first ejector pin is greater than the height of the second ejector pin; the first ejector pin and the second ejector pin have a first height difference; the distance between the second ejector pin and the first axis is a third distance; the third distance has a difference from the second distance. The third spacing has a difference from the first spacing; The step of determining the first detection result based on multiple sets of the first height data includes: Calculate the second height data of the abutment portion corresponding to each set of the first height data based on multiple sets of the first height data; Determine the maximum difference between any two of the second altitude data; Based on the fact that the maximum difference is less than the first height difference, the first test result is determined to be qualified, and the median or average value among multiple sets of the second height data is determined as the axial dimension of the fine grinding shaft; Based on the fact that the maximum difference is greater than or equal to the first height difference, the first test result is determined to be unqualified.

9. The method for detecting a precision-ground cross shaft according to claim 8, characterized in that, The distance between the abutting part and the first axis is adjustable; The cross-shaft precision grinding shaft inspection method also includes: Based on the first test result being qualified, the distance between the abutting part and the first axis is adjusted; Obtain the third height data of the measuring unit; Rotate the cross shaft around the axis of the grinding shaft to a preset angle; The process of returning to the step of acquiring the third height data of the measuring unit is repeated until multiple sets of the third height data are obtained. The second detection result is determined based on multiple sets of the third height data; the second detection result includes the axial dimension and end face perpendicularity of the precision-ground shaft.

10. A method for detecting a precision-ground cross shaft according to claim 9, characterized in that, The determination of the second detection result based on multiple sets of the third altitude data includes: Calculate the fourth height data of the abutment portion corresponding to each set of the third height data based on multiple sets of the third height data; Determine the second maximum difference between any two of the fourth altitude data; Based on the fact that the second maximum difference is less than the first height difference, the second test result is determined to be qualified, and the median or average value among multiple sets of the second height data is determined as the axial dimension of the fine grinding shaft; Based on the fact that the second maximum difference is greater than or equal to the first height difference, the second test result is determined to be unqualified.

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