A cam curve zoom lens barrel high-precision milling processing clamp

Abstract

The present application belongs to the field of processing tools of cam curve lens barrel, disclose a kind of cam curve zoom lens barrel high-precision milling clamps, including zoom lens barrel body, mandrel, centering ring, tool base, mandrel outer circle is designed with the angle guide groove four groups with bottom surface, for the filling of molten wax, the centering ring in the present application is placed in tool base, after being pressed, the change of inner hole and outer circle diameter, cooperate with mandrel outer circle and tool base;Through mandrel outer circle and tool base end face to zoom lens barrel body positioning, guarantee the rigidity and machining precision when zoom lens barrel body processing;Through the design of pin hole on zoom lens barrel body, ensure the starting position determination of cam curve milling when sub-clamping.This application simple structure, compact, operability is strong;Solved the low rigidity problem when zoom lens barrel cam curve milling.

Description

Technical Field

[0001] This invention belongs to the field of machining tools for cam curve lens barrels, specifically relating to a fixture for high-precision milling of a cam curve zoom lens barrel using a four-axis or five-axis machining center. Background Technology

[0002] The cam-curve zoom lens barrel is a crucial component in an optical zoom system. Its structure consists of two or more curved grooves of a certain angle and length wound around the circumference of the barrel wall. These curved grooves can be formed by milling. However, the structural characteristics of the zoom lens barrel reduce the rigidity of the workpiece during milling, and coupled with the cutting forces, it becomes difficult to guarantee the high-precision design requirements of the workpiece. Summary of the Invention

[0003] (I) Purpose of the Invention

[0004] The purpose of this invention is to provide a fixture for high-precision milling of zoom lens barrels with cam curves, which can accurately position the lens barrel body, perform low-stress clamping, and increase the rigidity of the zoom lens barrel body during cam curve milling, thereby improving the machining accuracy of the zoom lens barrel body.

[0005] (II) Technical Solution

[0006] To solve the above-mentioned technical problems, the present invention provides a fixture for high-precision milling of a cam curve zoom lens barrel, comprising: a mandrel 2, a centering ring 3, and a fixture base 4; the centering ring 3 is placed in a countersunk hole in the fixture base 4, one end of the mandrel 2 is installed in a hole in the centering ring 3, the inner cylindrical surface interface of one end of the zoom lens barrel body 1 mates with the outer cylindrical surface of the middle part of the mandrel 2, and one end face of the zoom lens barrel body 1 and the end face of the fixture base 4 are fixed by screws 8. During the fixing process, the centering ring 3 is compressed, causing changes in the inner and outer diameters, and the inner hole is compressed. The diameter is reduced and contacts the outer circle of one end of the mandrel 2. The outer circle pressure hole diameter is increased and matches the countersunk hole of the tooling base 4. The mandrel cover 5 is fixed to the other end face of the mandrel 2 by screws 8. An annular gap is formed between the outer wall of the other end of the mandrel 2 and the inner wall of the other end of the zoom lens barrel body 1. After the fixture is preheated, molten filling wax 6 is poured into the gap. After the molten filling wax 6 is solidified, the zoom lens barrel body 1 together with the tooling base 4 is installed on the worktable. Finally, a pin 11 is inserted between the mating end faces of the zoom lens barrel body 1 and the tooling base 4 for milling and positioning.

[0007] (III) Beneficial Effects

[0008] The fixture for high-precision milling of cam curve zoom lens barrel provided by the above technical solution has a simple and compact structure, which facilitates clamping and disassembly during operation. The device can effectively improve the rigidity of the part during milling and reduce the influence of cutting force while reducing clamping stress, thereby improving the machining accuracy of the cam curve and realizing high-precision milling. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the structure of a fixture for high-precision milling of a cam-curve zoom lens barrel proposed in this invention.

[0010] Figure 2 for Figure 1 A sectional view;

[0011] Figure 3 This is a schematic diagram of the zoom lens barrel.

[0012] Figure 4 This is a schematic diagram of the mandrel structure.

[0013] Figure 5 This is a schematic diagram of the centering ring.

[0014] In the diagram: 1-Zoom lens barrel body, 2-Spindle, 3-Centering ring, 4-Tooling base, 5-Spindle cap, 6-Filling wax, 7-Spindle weight reduction hole, 8-Screw, 9-Curved groove, 10-Drainage channel, 11-Pin Detailed Implementation

[0015] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0016] See Figure 1-5 As shown, the high-precision milling fixture for the zoom lens barrel of this embodiment includes a zoom lens barrel body 1, a mandrel 2, a centering ring 3, and a tooling base 4.

[0017] like Figure 1As shown, the centering ring 3 is placed in the countersunk hole of the tooling base 4, and one end of the mandrel 2 is installed in the hole of the centering ring 3. The inner cylindrical surface interface of one end of the zoom lens barrel body 1 mates with the outer cylindrical surface of the middle part of the mandrel 2. The end face of one end of the zoom lens barrel body 1 and the end face of the tooling base 4 are fixed by screws 8. During the fixing process, the centering ring 3 is compressed, causing the inner and outer diameters to change. The inner diameter is reduced by the pressure and contacts the outer diameter of one end of the mandrel 2, while the outer diameter is increased by the pressure and mates with the countersunk hole of the tooling base 4. The mandrel cover 5 is fixed to the other end face of the mandrel 2 by screws 8. An annular gap is formed between the outer wall of the other end of the mandrel 2 and the inner wall of the other end of the zoom lens barrel body 1. After the fixture is preheated, molten filling wax 6 is poured into the gap. After the molten filling wax 6 is cured, the zoom lens barrel body 1 and the tooling base 4 are installed as a whole on the worktable. Finally, a pin 11 is inserted between the mating end faces of the zoom lens barrel body 1 and the tooling base 4 for milling and positioning.

[0018] In this embodiment, the flatness requirement of both end faces of the tooling base 4 is 0.01 to 0.02; the perpendicularity requirement of the countersunk hole of the tooling base 4 to the assembly end face of one end of the zoom lens barrel body 1 is 0.01 to 0.02; the coaxiality requirement of the outer circle of the middle part of the mandrel 2 that mates with the zoom lens barrel body 1 and the outer circle of the end part of the mandrel 2 that mates with the centering ring 3 is 0.01 to 0.02; the perpendicularity requirement of the installation of the outer circle of the middle part of the mandrel 2 that mates with the zoom lens barrel body 1 and the outer circle of the end part of the mandrel 2 that mates with the centering ring 3 to the end face of the mandrel 2 and the tooling base 4 is 0.01 to 0.02. The positional tolerance of the outer circle of the middle part of the mandrel 2 and the zoom lens barrel body 1 is H7 / h6. These technical requirements are all to ensure the positioning accuracy of the zoom lens barrel body 1 during the clamping process.

[0019] In this embodiment, the radius of the annular gap between the outer circle of the other end of the mandrel 2 and the zoom lens barrel body 1 is 3mm; four sets of guide grooves 10 are designed at intervals along the parallel axial direction on the outer cylindrical surface of the other end of the mandrel 2. The bottom of each set of guide grooves is designed with a slope structure with an angle of 2° to 3°, which fully ensures the flow and filling of the molten filling wax 6, ensures the rigidity of the workpiece during milling and the adhesion between the filling wax 6 and the mandrel 2, and prevents the filling wax 6 from loosening during the milling process.

[0020] To improve operability and usability, a weight-reducing countersunk hole 7 is designed in the center of the mandrel 2 to achieve the purpose of weight reduction; furthermore, the mandrel cover 5 is assembled with the mandrel 2 to prevent the molten filling wax 6 from flowing into the opening side of the weight-reducing countersunk hole 7 during wax pouring, thereby reducing the waste of raw materials and improving work efficiency.

[0021] like Figure 5As shown, the ratio of the inner and outer diameters of the centering ring 3 is designed to be 9 / 14, the wall thickness is 1.5mm, and the material is 65Mn. It is placed in the countersunk hole of the tooling base 4. After axial compression, the inner diameter decreases and the outer diameter increases, which achieves the purpose of automatic centering and also reduces weight. The inner hole of the centering ring 3 matches the outer circle of the mandrel 2, and the outer circle of the centering ring 3 matches the inner hole of the tooling base 4 to ensure the machining accuracy of the zoom lens barrel body 1.

[0022] In this embodiment, a pin 11 is designed between any two screws 8 between one end face of the zoom lens barrel body 1 and the end face of the tooling base 4, for determining the starting position when multiple clamping operations are performed on the curved groove 9 on the outer circle of the zoom lens barrel body 1.

[0023] After the zoom lens barrel body 1, spindle 2, centering ring 3 and tooling base 4 are assembled, they are placed in a resistance furnace for preheating to ensure that the wax filling process is fully filled.

[0024] After the zoom lens barrel body 1 and the fixture have been preheated, molten filling wax 6 is poured into the gap between the zoom lens barrel body 1 and the mandrel 2. After the wax pouring stage is completed and cooled, pins 11 are inserted into the process pin holes of the zoom lens barrel body 1 to ensure the positioning of the curved groove 9 during multiple clamping and milling. Finally, the entire assembly is pressed onto the worktable with the end face of the tooling base 4 before the rigid milling of the curved groove 9 can be performed to ensure the machining accuracy of the curved groove 9.

[0025] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A fixture for high-precision milling of a cam-curve zoom lens barrel, characterized in that, include: The mandrel (2), centering ring (3), and tooling base (4) are arranged in a countersunk hole in the tooling base (4). One end of the mandrel (2) is installed in the hole of the centering ring (3). The cylindrical interface of the inner hole of one end of the zoom lens barrel body (1) is fitted with the outer cylindrical surface of the middle part of the mandrel (2). The end face of one end of the zoom lens barrel body (1) and the end face of the tooling base (4) are fixed by screws (8). During the fixing process, the centering ring (3) is compressed, causing the inner hole and outer circle diameters to change. The inner hole is compressed, the diameter decreases, and it contacts the outer circle of one end of the mandrel (2). The outer circle is compressed. The pressure hole diameter is increased and matched with the countersunk hole of the tooling base (4); the mandrel cover (5) is fixed to the other end face of the mandrel (2) by screws (8); an annular gap is formed between the outer wall of the other end of the mandrel (2) and the inner wall of the other end of the zoom lens barrel body (1). After the fixture is preheated, molten filling wax (6) is poured into the gap. After the molten filling wax (6) is solidified, the zoom lens barrel body (1) together with the tooling base (4) is installed on the worktable. Finally, a pin (11) is inserted between the mating end faces of the zoom lens barrel body (1) and the tooling base (4) for milling and positioning. Four sets of guide grooves (10) are designed at intervals along the parallel axial direction on the outer cylindrical surface of the other end of the mandrel (2). The bottom of each set of guide grooves is designed with a slope structure with an angle of 2°~3°. The mandrel (2) is designed with a weight-reducing countersunk hole (7) in the center. The mandrel cover (5) is assembled with the mandrel (2) and covers the opening side of the weight-reducing countersunk hole (7). The centering ring (3) is designed with an inner-to-outer diameter ratio of 9 / 14, a wall thickness of 1.5 mm, and is made of 65Mn material; Between one end face of the zoom lens barrel body (1) and the end face of the tooling base (4), a pin (11) is designed between any two screws (8) to determine the starting position when multiple clamping and machining of the curved groove (9) on the outer circle of the zoom lens barrel body (1).

2. The fixture for high-precision milling of cam-curve zoom lens barrels as described in claim 1, characterized in that, The radius of the annular gap between the outer circle of the other end of the spindle (2) and the zoom lens barrel body (1) is 3mm.

3. The fixture for high-precision milling of cam curve zoom lens barrel as described in claim 2, characterized in that, The flatness requirement of both ends of the tooling base (4) is 0.01~0.02; the perpendicularity requirement of the countersunk hole of the tooling base (4) and the end face of the zoom lens barrel body (1) is 0.01~0.

02.

4. The fixture for high-precision milling of cam-curve zoom lens barrels as described in claim 3, characterized in that, The coaxiality requirement between the outer circle of the middle part of the mandrel (2) that mates with the zoom lens barrel body (1) and the outer circle of the end part of the mandrel (2) that mates with the centering ring (3) is 0.01~0.

02.

5. The fixture for high-precision milling of cam curve zoom lens barrel as described in claim 4, characterized in that, The verticality requirement for the end face of the mandrel (2) that mates with the zoom lens barrel body (1) and the end face of the mandrel (2) that mates with the centering ring (3) is 0.01~0.

02.

6. The fixture for high-precision milling of cam curve zoom lens barrel as described in claim 5, characterized in that, The positional tolerance between the outer circle of the middle part of the spindle (2) and the zoom lens barrel body (1) is H7 / h6.

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