Adjusting and positioning device for machining crosshead pin of variable-compression-ratio part

Abstract

The utility model relates to an adjusting and positioning device for machining a crosshead pin of a variable compression ratio part. Comprising a basic positioning mechanism arranged on a working table of a vertical turning and milling machine tool of the machine tool, a V-shaped base used for placing the crosshead pin, an adjustable supporting mechanism used for axially positioning the crosshead pin, and a pressing mechanism used for pressing the V-shaped base and the crosshead pin. All positioning and clamping precision of the crosshead pin before finish machining can be effectively controlled during operation, correction and adjustment are convenient and efficient, the surface of the crosshead pin is effectively protected, and it is ensured that all procedures are finished through one-time clamping station finish machining of all profiles of a piston hole of the crosshead pin on a vertical turn-milling machine tool.

Description

Technical Field

[0001] This application relates to the field of parts processing technology, and in particular to an adjustment and positioning device for machining crosshead pins of variable compression ratio parts. Background Technology

[0002] In marine engines, the flexible adjustment of the piston stroke is achieved within the piston bore of the crosshead pin component. While bearing the precise connection between the connecting rod and the piston rod hinge pin, the crosshead pin component's internal cavity must also meet the motion accuracy requirements of the dynamic cylinder piston. The piston motion accuracy within the crosshead pin cavity is closely related to the cyclic reciprocating oscillation accuracy of the crosshead pin's outer diameter within the connecting rod slide bearing. During the manufacturing process, the crosshead pin needs to be clamped and fixed using fixtures. Currently, the manufacturing process of the crosshead pin requires processing using different equipment, necessitating multiple loading and unloading operations on different machine tools. This is complex, time-consuming, and labor-intensive. Furthermore, the fixtures on the corresponding machine tools cannot accurately position the crosshead pin, failing to ensure the coaxiality and perpendicularity accuracy between the crosshead pin and the machining tool, resulting in significant machining errors. Summary of the Invention

[0003] To improve the accuracy and ease of machining crosshead pins, this invention provides an adjustment and positioning device for machining crosshead pins of variable compression ratio parts.

[0004] A calibration and positioning device for machining crosshead pins of variable compression ratio parts includes a basic positioning mechanism set on the worktable of a vertical turning and milling machine, a V-shaped base for placing the crosshead pin, an adjustable support mechanism for axial positioning of the crosshead pin, and a clamping mechanism for clamping the V-shaped base and the crosshead pin.

[0005] Preferably, the basic positioning mechanism includes at least two support components symmetrically arranged on the worktable of the vertical turning and milling machine for supporting the V-shaped base, and chuck components symmetrically arranged on the worktable of the vertical turning and milling machine for adjusting and clamping the outer circular surface of the V-shaped base; the bottom surface of the V-shaped base is placed on the upper plane of the support components.

[0006] Preferably, the support component consists of four symmetrically distributed, equally-height fixed pads, and the claw component consists of four evenly distributed, adjustable claws.

[0007] Preferably, the adjustable chuck includes a chuck frame mounted on the worktable of a vertical turning and milling machine by screws, a chuck block slidably mounted on the chuck frame, a threaded hole on the chuck frame, a clamping screw disposed in the threaded hole, and the clamping screw rotatably mounted on the chuck block.

[0008] Preferably, the adjustable support mechanism includes a positioning seat, a positioning component, a fixing component, and an adjusting component; the positioning seat is close to the stepped surface of the V-shaped base, positioned by the positioning component, and tightened and fixed to the stepped surface of the V-shaped base by the fixing component; the adjusting component is provided on the positioning seat for adjusting and fixing the axial position of the crosshead pin.

[0009] Preferably, the positioning element is two internally threaded cylindrical pins, the fixing element is four internal hexagonal head screws, the adjusting element is a fine-tooth set screw, and the positioning seat and the V-shaped base are both provided with threaded pin holes that cooperate with the internally threaded cylindrical pins and threaded holes that cooperate with the internal hexagonal head screws.

[0010] Preferably, the end of the fine-tooth set screw is spherical with a hexagonal outer circle. The spherical end of the fine-tooth set screw is used to adjust and fix the axial position of the crosshead pin during the rotational feed motion.

[0011] Preferably, the clamping mechanism includes a first clamping component for pressing the V-shaped base onto the upper plane of the support component and a second clamping component for pressing the crosshead pin onto the V-shaped inclined surface of the V-shaped base; the V-shaped base is provided with a threaded connection part, and the second clamping component cooperates with the threaded connection part to clamp the crosshead pin.

[0012] Preferably, the threaded connection includes two double-ended bolts arranged symmetrically along the axial direction of the V-shaped base;

[0013] The second clamping component includes two elongated pressure plates. The elongated pressure plates have waist-shaped grooves at both ends for two double-headed bolts to pass through. An arc-shaped copper plate is embedded in the middle of the elongated pressure plates. The two elongated pressure plates press the crosshead pin against the two V-shaped inclined surfaces of the V-shaped base by tightening four double-headed bolts and hexagonal nuts.

[0014] Preferably, the first clamping component includes T-slots evenly spaced along the circumference of the vertical turning and milling machine table, a T-nut slidably disposed in the T-slot, a double-ended screw connected inside the T-nut, a height pad that mates with the double-ended screw on the vertical turning and milling machine table, a rectangular pressure plate placed on the height pad, a waist-shaped groove formed on the rectangular pressure plate, the double-ended screw passing through the waist-shaped groove, a clamping nut at the upper end of the double-ended screw, and a washer fitted on the T-nut located between the clamping nut and the rectangular pressure plate.

[0015] Beneficial effects

[0016] The calibration and positioning device for crosshead pin machining designed in this invention can effectively control all positioning and clamping accuracy before the crosshead pin finish machining. The calibration is convenient and efficient, and it effectively protects the surface of the crosshead pin, ensuring that all processes of the crosshead pin piston hole are completed in one clamping station on a vertical milling machine.

[0017] The adjustable support mechanism's fine-tooth set screw allows for precise adjustment of the crosshead pin's axial position, while the clamping mechanism provides double clamping to prevent component displacement.

[0018] Each component is easy to adjust and can accommodate crosshead pins and V-shaped bases of different sizes and specifications.

[0019] The arc-shaped copper plate protects the surface of the parts, and precise positioning and clamping improve processing quality. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a three-dimensional structural diagram of this application.

[0022] Figure 2 This is a structural diagram of the V-shaped base, adjustable support mechanism, double-headed bolt, long pressure plate and hexagonal nut of this application.

[0023] Figure 3 This application Figure 1 A magnified view of part a.

[0024] Figure 4 This application Figure 1 A magnified view of section b.

[0025] Figure 5 This application Figure 1 A magnified view of a portion at point c.

[0026] Explanation of reference numerals in the attached drawings: 1. Vertical milling machine worktable; 2. Adjustable chuck; 3. Adjustable support mechanism; 3-1. Positioning seat; 3-2. Socket head cap screw; 3-3. Internal threaded cylindrical pin; 3-4. Fine-tooth set screw; 5. Double-ended bolt; 6. Long pressure plate; 6-2. Arc-shaped copper plate; 7. V-shaped base; 8. Hex nut; 14. Phillips head pin; 15. Equal height fixing block; 16. Rectangular pressure plate. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0028] like Figures 1 to 5 As shown: A calibration and positioning device for machining crosshead pins of variable compression ratio parts: including a basic positioning mechanism on the worktable 1 of a vertical milling and turning machine tool, a V-shaped base 7 for placing the crosshead pin 14, an adjustable support mechanism 3 for axial positioning of the crosshead pin 14, and a clamping mechanism for clamping the V-shaped base 7 and the crosshead pin 14. The adjustable support mechanism 3 ensures rapid calibration and positioning of the crosshead pin 14's length symmetry center with the center of the worktable 1 of the vertical milling and turning machine tool during operation.

[0029] The basic positioning mechanism includes at least two support components symmetrically arranged on the worktable 1 of the vertical turning and milling machine for supporting the V-shaped base 7, and chuck components symmetrically arranged on the worktable 1 of the vertical turning and milling machine for adjusting and clamping the outer circular surface of the V-shaped base 7; the bottom surface of the V-shaped base 7 is placed on the upper plane of the support components.

[0030] The V-shaped base 7 is made of ductile iron QT400. After rough machining, it undergoes heat treatment to relieve stress. The semi-finishing and finishing of the V-shaped base 7 are carried out in separate steps. The flatness of the bottom plane of the V-shaped base is strictly controlled to be ≤0.01mm, and the parallelism between the V-shaped surface and the bottom surface is controlled to be ≤0.02mm. The two V-shaped surfaces are guaranteed to have consistent angles with the bottom surface, and the symmetry with respect to the outer circle of the V-shaped base 7 is ≤0.02mm. This ensures that the crosshead pin 14 can be quickly adjusted, positioned, and clamped on the V-shaped base 7.

[0031] The supporting components include four equal-height fixing blocks 15 arranged on the worktable 1 of the vertical turning and milling machine tool. Before the V-shaped base 7 is turned, the upper surface of the equal-height fixing blocks 15 is precision-machined by the turning tool of the vertical turning and milling machine tool to ensure that the height error of the fixing blocks is ≤0.005mm. The chuck components are four adjustable chucks 2 independently arranged on the worktable 1 of the vertical turning and milling machine tool. The four adjustable chucks 2 are used to adjust and clamp the rotational coaxiality between the outer circle of the V-shaped base 7 and the worktable 1 of the vertical turning and milling machine tool. After the worktable 1 of the vertical turning and milling machine tool tool is corrected to ≤0.01mm on the outer circle of the V-shaped base 7, it clamps and constrains the outer circle of the V-shaped base 7. At the same time, four sets of rectangular pressure plates 16 are used to press the V-shaped base firmly onto the equal-height fixing blocks 15.

[0032] The adjustable chuck 2 includes a chuck frame that is screwed onto the worktable 1 of the vertical milling and turning machine. A chuck block is slidably mounted on the chuck frame. A threaded hole is provided on the chuck frame, and a clamping screw is provided in the threaded hole. The clamping screw is rotatably mounted on the chuck block.

[0033] The adjustable support mechanism 3 includes a positioning seat 3-1, a positioning component, a fixing component, and an adjusting component; the positioning seat 3-1 is close to the stepped surface of the V-shaped base 7, positioned by the positioning component, and tightened and fixed to the stepped surface of the V-shaped base 7 by the fixing component; the adjusting component is provided on the positioning seat 3-1.

[0034] The positioning component is two internally threaded cylindrical pins 3-3, the fixing component is four internal hexagonal head screws 3-2, and the adjusting component is a fine-tooth set screw 3-4;

[0035] The fine-tooth set screw 3-4 is mounted on the positioning seat 3-1 via a threaded connection. The end of the fine-tooth set screw 3-4 is spherical with a hexagonal outer circle. Rotating the fine-tooth set screw 3-4 allows the spherical end to be used to adjust and fix the axial position of the crosshead pin 14 during the rotary feed motion.

[0036] The crosshead pin 14 is placed on the V-shaped inclined surface of the V-shaped base 7 by hoisting. At this time, due to the positioning in the previous step and the guarantee of its own dimensional accuracy and geometric tolerance accuracy, the outer circle axis of the crosshead pin 14 is aligned with the symmetrical center line of the vertical turning and milling machine table 1. By adjusting the fine tooth set screws 3-4 in the adjustable support mechanism 3 at both ends, the symmetrical center line of the length of the crosshead pin 14 is made to coincide with the symmetrical center line of the vertical turning and milling machine table 1. Then, a dial indicator is used to correct the levelness of the piston hole plane of the crosshead pin 14 to ≤0.02mm.

[0037] The clamping mechanism includes a first clamping component for pressing the V-shaped base 7 onto the upper plane of the support component and a second clamping component for pressing the crosshead pin 14 onto the V-shaped inclined surface of the V-shaped base 7; the V-shaped base 7 is symmetrically provided with two sets of threaded connection parts, and the second clamping component is disposed on the two sets of threaded connection parts. The second clamping component cooperates with the two sets of threaded connection parts to clamp the crosshead pin 14, and the first clamping component is disposed on the worktable 1 of the vertical milling and turning machine.

[0038] The first clamping component includes T-slots evenly opened around the circumference of the worktable 1 of the vertical turning and milling machine tool. A T-nut is slidably arranged in the T-slot, and a double-ended screw is connected in the T-nut. A height pad that cooperates with the double-ended screw is provided on the worktable 1 of the vertical turning and milling machine tool. A rectangular pressure plate 16 is placed on the height pad. A waist-shaped groove is opened on the rectangular pressure plate 16. The double-ended screw passes through the waist-shaped groove. A clamping nut is provided at the upper end of the double-ended screw, and a washer is fitted on the T-nut located between the clamping nut and the rectangular pressure plate 16.

[0039] Before clamping the V-shaped base 7, the equal height fixing pad 15 is precision machined to ensure the equal height of the clamping base plane. After adjusting the outer circle of the V-shaped base 7, the rectangular pressure plate 16 is pressed firmly onto the equal height fixing pad 15 by the cooperation of the clamping nut and the double-ended screw. In this state, the two ends of the rectangular pressure plate 16 are located on the V-shaped base 7 and the height pad respectively.

[0040] The threaded connection includes two double-ended bolts 5 arranged symmetrically along the axial direction of the V-shaped base 7. The second clamping component consists of two elongated pressure plates 6. The elongated pressure plates 6 have waist-shaped grooves at both ends for the double-ended bolts 5 to pass through. An arc-shaped copper plate 6-2 is embedded in the middle of the elongated pressure plates 6. The two elongated pressure plates 6 are tightened by four double-ended bolts 5 and hexagonal nuts 8 to press the crosshead pin 14 onto the two V-shaped inclined surfaces of the V-shaped base 7.

[0041] When the piston hole is precision machined, the outer diameter of the crosshead pin 14 is semi-finish ground with a allowance of Φ1mm, but the cylindricity of the outer diameter of the semi-finish ground crosshead pin 14 is guaranteed to be ≤0.01mm. After the piston hole is precision machined, the outer diameter of the crosshead pin 14 is finely ground and polished to the finished product after adjustment based on the semi-finished outer diameter. Therefore, the slight bumps or pressure marks caused by the outer diameter of the crosshead pin 14 being placed on the V-shaped surface of the V-shaped base 7 do not affect the final surface quality because there is still a margin. The long pressure plate 6 used to clamp the crosshead pin 14 is designed as an arc-shaped copper plate 6-2 for contact with the crosshead pin 14, which expands the clamping surface for fastening. Moreover, the hardness of the copper plate material is much lower than that of the crosshead pin material, so it does not cause indentation damage to the outer diameter of the crosshead pin.

[0042] Two sets of elongated pressure plates 6 are used to press the crosshead pin 14 and secure it to the V-shaped inclined surface of the V-shaped base 7. The arc-shaped copper plate 6-2 is in direct contact with the outer circle of the crosshead pin 14 to protect the outer circle surface from pressure mark damage.

[0043] After the crosshead pin 14 is positioned and secured on the V-shaped base 7, the vertical milling machine tool first selects a cutting tool to perform precision turning on the non-quenched surface and the rounded R-corner inside the piston hole. Then, the cutting tool post is removed from the machine tool slide spindle, the milling spindle is installed, and the quenched hole surface and end face inside the piston hole are precision ground with a suitable grinding head, tool holder and grinding wheel to ensure that all surfaces of the piston hole are precision machined in one clamping station.

[0044] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A calibration and positioning device for machining crosshead pins of variable compression ratio parts, characterized in that, It includes a basic positioning mechanism on the worktable of a vertical milling and turning machine tool, a V-shaped base for placing the crosshead pin, an adjustable support mechanism for axial positioning of the crosshead pin, and a clamping mechanism for clamping the V-shaped base and the crosshead pin. The basic positioning mechanism includes at least two support components symmetrically arranged on the worktable of the vertical turning and milling machine for supporting the V-shaped base, and chuck components symmetrically arranged on the worktable of the vertical turning and milling machine for adjusting and clamping the outer circular surface of the V-shaped base; the bottom surface of the V-shaped base is placed on the upper plane of the support components.

2. The adjustment and positioning device for machining crosshead pins of variable compression ratio parts according to claim 1, characterized in that, The support component consists of four symmetrically distributed, equally-height fixed pads, and the claw component consists of four evenly distributed, adjustable claws.

3. The adjustment and positioning device for machining crosshead pins of variable compression ratio parts according to claim 2, characterized in that, The adjustable chuck includes a chuck frame mounted on the worktable of a vertical milling and turning machine tool by screws. A chuck block is slidably mounted on the chuck frame. A threaded hole is opened on the chuck frame, and a clamping screw is installed in the threaded hole. The clamping screw is rotatably mounted on the chuck block.

4. The adjustment and positioning device for machining crosshead pins of variable compression ratio parts according to claim 1, characterized in that, The adjustable support mechanism includes a positioning seat, a positioning component, a fixing component, and an adjusting component; the positioning seat is close to the stepped surface of the V-shaped base, positioned by the positioning component, and tightened and fixed to the stepped surface of the V-shaped base by the fixing component; the adjusting component is set on the positioning seat.

5. The adjustment and positioning device for machining crosshead pins of variable compression ratio parts according to claim 4, characterized in that, The positioning component consists of two internally threaded cylindrical pins, the fixing component consists of four internal hexagonal head screws, and the adjusting component consists of a fine-tooth set screw.

6. The adjustment and positioning device for machining crosshead pins of variable compression ratio parts according to claim 5, characterized in that, The fine-tooth set screw is mounted on the positioning seat via a threaded connection. The end of the fine-tooth set screw is spherical with a hexagonal outer circle. Rotating the fine-tooth set screw allows the spherical end to be used to adjust and fix the axial position of the crosshead pin during the rotary feed motion.

7. The adjustment and positioning device for machining crosshead pins of variable compression ratio parts according to claim 1, characterized in that, The clamping mechanism includes a first clamping component for pressing the V-shaped base onto the upper plane of the support component and a second clamping component for pressing the crosshead pin onto the V-shaped inclined surface of the V-shaped base; the V-shaped base is symmetrically provided with two sets of threaded connection parts, the second clamping component is disposed on the two sets of threaded connection parts, the second clamping component cooperates with the two sets of threaded connection parts to clamp the crosshead pin, and the first clamping component is disposed on the worktable of the vertical turning and milling machine.

8. The adjustment and positioning device for machining crosshead pins of variable compression ratio parts according to claim 7, characterized in that, The threaded connection includes two double-ended bolts arranged symmetrically along the axial direction of the V-shaped base. The second clamping component includes two elongated pressure plates. The elongated pressure plates have waist-shaped grooves at both ends for two double-headed bolts to pass through. An arc-shaped copper plate is embedded in the middle of the elongated pressure plates. The two elongated pressure plates press the crosshead pin against the two V-shaped inclined surfaces of the V-shaped base by tightening four double-headed bolts and hexagonal nuts.

9. A calibration and positioning device for machining crosshead pins of variable compression ratio parts according to claim 8, characterized in that, The first clamping component includes T-slots evenly spaced along the circumference of the worktable of the vertical turning and milling machine. A T-nut is slidably disposed in the T-slot, and a double-ended screw is connected inside the T-nut. A height pad that mates with the double-ended screw is disposed on the worktable of the vertical turning and milling machine. A rectangular pressure plate is placed on the height pad. A waist-shaped groove is formed on the rectangular pressure plate. The double-ended screw passes through the waist-shaped groove. A clamping nut is disposed at the upper end of the double-ended screw, and a washer is fitted on the T-nut located between the clamping nut and the rectangular pressure plate.

Images