A new involute spline mandrel sector support device and method of use thereof

Abstract

The application belongs to the technical field of high-precision grinding of a core shaft of a large extrusion granulator unit, and discloses a novel involute spline core shaft sector support device and a use method thereof. Locking pressing plates are mounted on both sides of the bottom of the sector support body and positioned on a sliding rail; a side support adjusting device adjusts the extension and retraction amount of a side support column; a lower support adjusting device adjusts the extension and retraction amount of a lower support column; the other end of the lower support column is connected with a sector support tile body; the sector support tile body is made of nylon; the sector arc of the sector support tile body is an interval of 10° to 20°; a spherical positioning rod has one end connected with the sector support tile body and the other end respectively clamped in two semicircular grooves on a 10° inclined surface at the front end of the side support column. The application solves the problem that high-precision involute spline core shafts cannot be supported for high-precision and stable machining after hobbing, realizes high-precision grinding effect, and comprehensively solves the high-precision grinding problem of high-precision involute spline parts.

Description

Technical Field

[0001] This invention relates to the field of high-precision grinding technology for mandrels of large extrusion granulation units, and particularly to a novel fan-shaped support device for involute spline mandrels and its usage method. Background Technology

[0002] High-precision involute spline mandrel machining technology is a key project for domestic production. There is no domestic industry experience or innovative methods to draw upon. The goal is to completely solve the pain points and difficulties in machining key core components for large extrusion granulation units in the petrochemical industry. Currently, there are four companies internationally capable of producing "350" and "380" large units: two in Japan, one in Germany, and China's Daxiang Plastics Group. The high-precision involute spline mandrel is 13 meters long. The highest international standard for part machining accuracy is a straightness requirement of 0.15mm and a concentricity requirement of 0.03mm across the entire length. To achieve international high-precision machining standards, it is essential to solve the problem of stable support for the involute spline mandrel after gear hobbing. Summary of the Invention

[0003] After gear hobbing, high-precision involute spline mandrels require high-precision grinding. Because the involute spline on the outer diameter of the mandrel is already machined, and the outer diameter has discontinuous tooth surfaces, direct support grinding is not feasible. This prevents the optimal machining process from being successfully implemented, resulting in the mandrel's machining data failing to meet the highest international standards. To address the accuracy and stability issues in grinding high-precision involute spline mandrels after gear hobbing, a fan-shaped surface support principle is used to improve machining positioning stability, thereby increasing machining efficiency and accuracy. This comprehensively solves the problem of machining accuracy for domestically produced high-precision involute spline mandrels. A novel fan-shaped support device for involute spline mandrels and its application method are proposed.

[0004] The technical solution of the present invention is as follows: A novel involute spline mandrel sector support device, comprising a sector support body 1, a side support adjustment device 2, a lower support adjustment device 3, a locking pressure plate 4, a lower support column 5, a sector support tile 6, a side support column 7, and a spherical positioning rod 8;

[0005] The fan-shaped support body 1 has two sides that form an angle of 2° with the vertical line; locking pressure plates 4 are installed on both sides of the bottom to adjust and fix the position of the fan-shaped support body 1 on the slide rail.

[0006] The side of the fan-shaped support body 1 is respectively equipped with a side support adjustment device 2 and a lower support adjustment device 3;

[0007] The side support adjustment device 2 is connected to one end of the side support column 7 and is used to adjust the extension and retraction of the side support column 7; the other end of the side support column 7 is connected to the side of the fan-shaped support tile body 6.

[0008] One end of the lower support adjustment device 3 is in contact with one end of the lower support column 5 and is used to adjust the extension and retraction of the lower support column 5; the other end of the lower support column 5 is connected to the fan-shaped support tile body 6.

[0009] The fan-shaped support tile 6 is made of nylon; the fan-shaped arc of the fan-shaped support tile 6 is in the range of 174° to 178°, ensuring that the number of teeth wrapped by the new involute spline mandrel fan-shaped support device exceeds 48% of the total number of teeth of the involute spline mandrel.

[0010] Two spherical positioning rods 8 are provided. One end is connected to the fan-shaped support tile 6, and the other end is respectively stuck in two semi-circular grooves on the 10° inclined surface at the front end of the side support column 7. Only two spherical positioning rods 8 are used for single positioning in the radial rotation direction, ensuring that the fan-shaped support tile 6 is automatically centered when it is attached to the outer circle of the spline mandrel, and ensuring a contact rate of more than 90% with the spline tooth surface of the part.

[0011] The contact surface between the lower support adjustment device 3 and the lower support column 5 is an inclined surface.

[0012] The arc length of the fan-shaped support tile 6 extends towards the grinding contact point between the grinding wheel and the spline mandrel, and the extension angle from the vertical line connecting the center of the arc to the grinding contact point between the grinding wheel and the spline mandrel is 59.4°.

[0013] The novel involute spline mandrel fan-shaped support device is provided in multiple configurations, with the straightness between them within 0.30mm error, and the roundness and concentricity error of the fan-shaped support tile body controlled within 0.05mm.

[0014] A method for using a novel involute spline mandrel sector support device includes the following steps:

[0015] Step 1: Install the fan-shaped support body 1, side support adjustment device 2, lower support adjustment device 3, lower support column 5, and side support column 7. Install multiple fan-shaped support devices evenly on the equipment track at a spacing of 2500mm, and fix them with locking pressure plate 4, ensuring that the straightness is controlled within 0.30mm.

[0016] Step 2: Using the spherical positioning rod 8, install the sector-shaped support tile 6 onto the side support column 7 and the lower support column 5. Fix the dial indicator on the grinding wheel head frame to check and verify the roundness and concentricity of the four sector-shaped support tiles. The accuracy is controlled within 0.05mm. During the grinding process, the four sector-shaped support tiles 6 complete the self-positioning function; the positioning of the involute spline mandrel sector-shaped support device is completed.

[0017] Step 3: Before grinding, use a dial indicator to check the spline mandrel. Use the side support adjustment device 2 and the lower support adjustment device 3 to align the upper generatrix and side generatrix. Check the accuracy values ​​of the spline mandrel without any degree of freedom constraint, and control them within 0.10mm. Use high-precision rotary elastic centers for the support at both ends. The spline mandrel positioning is complete.

[0018] Step 4: Using the new type of involute spline mandrel sector support device, locate the original support reference point for spline mandrel grinding. Use a dial indicator to check and verify that the support reference points of the four sector support devices are consistent with the reference points of the two end centers, and the accuracy is controlled within 0.02mm.

[0019] Step 5: During the grinding process, the side support adjustment device 2 and the lower support adjustment device 3 should be continuously fine-tuned to ensure the stability and accuracy requirements of the spline mandrel during grinding.

[0020] The beneficial effects of this invention: The high-precision involute spline mandrel sector-shaped support device is an industry-unique and original technology, and a unique processing technology solution has been developed, filling the gap in domestic processing technology for ultra-long, high-precision involute spline parts. It solves the problem of high-precision, stable processing support for high-precision involute spline mandrels after gear hobbing, achieving high-precision grinding results. To comprehensively improve the stability and engagement rate of the grinding support, the sector-shaped support body is made of flexible and ductile nylon (polyamide Nylon), upgrading and optimizing the traditional columnar support method, thus comprehensively solving the high-precision grinding processing problem of high-precision involute spline parts. During the grinding process, fine adjustments are made through side and lower support columns to ensure the constant support force of the sector-shaped support device on the mandrel sector surface, ensuring that all processing precision reaches the highest industry standards. Through the application of the sector-shaped support device, the domestic processing technology upgrade for high-precision involute spline mandrels is ultimately achieved, making it an industry first. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a novel involute spline mandrel fan-shaped support device.

[0022] Figure 2 This is a schematic diagram of the working structure of a novel involute spline mandrel sector support device.

[0023] Figure 3 This is a schematic diagram of the combined use of a novel involute spline mandrel fan-shaped support device.

[0024] In the diagram: 1-fan-shaped support body; 2-side support adjustment device; 3-lower support adjustment device; 4-locking pressure plate; 5-lower support column; 6-fan-shaped support tile; 7-side support column; 8-spherical positioning rod. Detailed Implementation

[0025] This invention proposes a novel sector-shaped support device for involute spline mandrels, such as... Figure 1 As shown: It consists of 1 fan-shaped support body, 1 side support adjustment device 2, 1 lower support adjustment device 3, 2 locking pressure plates 4, 1 lower support column 5, 1 fan-shaped support tile body 6, 1 side support column 7, and 2 spherical positioning rods 8.

[0026] The specific implementation method is as follows: Before finishing, high-precision equipment is used to check and verify information such as straightness, roundness, concentricity, and bending trend value. The straightness between the fan-shaped support devices should be within 0.30mm, the roundness of the fan-shaped support pad should be within 0.05mm, and the concentricity of the fan-shaped support pad should be within 0.05mm. This device is suitable for situations where the bending trend value of the spline mandrel is within 60°. Using the high-precision fan-shaped support device, the original support reference point is positioned, and the accuracy values ​​of various aspects are checked and controlled within 0.10mm when the mandrel is not constrained by any degree of freedom. High-precision rotary elastic centers are used for the two ends to support the mandrel. The advantage is that it reduces the increase of friction in the center hole and increases the support toughness and buffer force. The middle support of the mandrel uses an involute spline mandrel fan-shaped support device. The fan-shaped support pad is made of polyamide (Nylon), which has strong toughness and wear resistance, good support stability, and is not prone to wear and tear on the mandrel surface. The mandrel is supported by four sector-shaped support devices during machining (e.g., Figure 3 As shown), before grinding, a dial indicator should be used to align the upper and side generatrices of the mandrel to ensure the straightness of the grinding process. During use, the fan-shaped support body of the fan-shaped support device should extend 59.4° from the reference point below the vertical line of the arc center towards the grinding side. The number of teeth enclosed by the fan-shaped support device should exceed 48% of the total number of teeth on the involute spline mandrel. The fan arc should be between 174° and 178°. The fan-shaped support body and the side and bottom support columns are designed separately, using only two spherical positioning rods for single radial rotation positioning, ensuring a contact rate of over 90% with the spline tooth surface of the part (e.g., ...). Figure 2 (As shown).

Claims

1. A novel sector-shaped support device for an involute spline mandrel, characterized in that, The novel involute spline mandrel fan-shaped support device includes a fan-shaped support body (1), a side support adjustment device (2), a lower support adjustment device (3), a locking pressure plate (4), a lower support column (5), a fan-shaped support tile (6), a side support column (7), and a spherical positioning rod (8). The fan-shaped support body (1) has two sides that form an angle of 2° with the vertical line; locking plates (4) are installed on both sides of the bottom to adjust and fix the position of the fan-shaped support body (1) on the slide rail. The side of the fan-shaped support body (1) is respectively equipped with a side support adjustment device (2) and a lower support adjustment device (3); The side support adjustment device (2) is connected to one end of the side support column (7) and is used to adjust the extension and retraction of the side support column (7); the other end of the side support column (7) is connected to the side of the fan-shaped support tile (6); One end of the lower support adjustment device (3) is in contact with one end of the lower support column (5) to adjust the extension and retraction of the lower support column (5); the other end of the lower support column (5) is connected to the fan-shaped support tile (6); The fan-shaped support tile (6) is made of nylon; the fan-shaped arc of the fan-shaped support tile (6) is in the range of 174° to 178°, ensuring that the number of teeth wrapped by the new involute spline mandrel fan-shaped support device exceeds 48% of the total number of teeth of the involute spline mandrel. Two spherical positioning rods (8) are provided. One end is connected to the fan-shaped support tile (6), and the other end is respectively stuck in the two semi-circular grooves on the 10° inclined surface at the front end of the side support column (7). Only two spherical positioning rods (8) are used for single positioning in the radial rotation direction, ensuring that the fan-shaped support tile (6) automatically centers when it is attached to the outer circle of the spline mandrel, ensuring a contact rate of more than 90% with the spline tooth surface of the part.

2. The novel involute spline mandrel sector support device according to claim 1, characterized in that, The contact surface between the lower support adjustment device (3) and the lower support column (5) is an inclined surface.

3. The novel involute spline mandrel sector support device according to claim 1 or 2, characterized in that, The arc length of the fan-shaped support tile (6) extends towards the grinding contact point between the grinding wheel and the spline mandrel, and the extension angle from the vertical line connecting the center of the arc to the grinding contact point between the grinding wheel and the spline mandrel is 59.4°.

4. The novel involute spline mandrel sector support device according to claim 3, characterized in that, The novel involute spline mandrel fan-shaped support device is provided in multiple units, with the straightness between them within 0.30mm error, and the roundness and concentricity error of the fan-shaped support tile (6) controlled within 0.05mm.

5. A method of using the novel involute spline mandrel sector support device according to claim 4, characterized in that, The steps include the following: Step 1: Install the fan-shaped support body (1), side support adjustment device (2), lower support adjustment device (3), lower support column (5), and side support column (7). Install multiple fan-shaped support devices evenly on the equipment track at a spacing of 2500mm, and fix them with locking plates (4), ensuring that the straightness is controlled within 0.30mm. Step 2: Using the spherical positioning rod (8), install the fan-shaped support tile (6) onto the side support column (7) and the lower support column (5). Fix the dial indicator on the grinding wheel head frame to check and verify the roundness and concentricity of the four fan-shaped support tiles. The accuracy is controlled within 0.05mm. During the grinding process, the four fan-shaped support tiles (6) complete the self-positioning function; the positioning of the involute spline mandrel fan-shaped support device is completed. Step 3: Before grinding, use a dial indicator to check the spline mandrel. Use the side support adjustment device (2) and the lower support adjustment device (3) to align the upper generatrix and side generatrix. Check the accuracy values ​​of the spline mandrel without degree of freedom constraint and control them within 0.10mm. Use high-precision rotary elastic centers for the two ends to support the mandrel. The spline mandrel positioning is completed. Step 4: Using the new type of involute spline mandrel sector support device, locate the original support reference point for spline mandrel grinding. Use a dial indicator to check and verify that the support reference points of the four sector support devices are consistent with the reference points of the two end centers, and the accuracy is controlled within 0.02mm. Step 5: During the grinding process, the side support adjustment device (2) and the lower support adjustment device (3) should be continuously fine-tuned to ensure the stability and accuracy requirements of the spline mandrel during grinding.

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