Butterfly-shaped staggered-tooth pressing clamp for machining curved cylindrical parts
By designing a butterfly malfunctioning tooth pressing clamp, the mandrel positioning and the butterfly pressing ring inclined into the lens barrel is solved, and the problems of spiral groove deformation, tool interference and cutting vibration in the processing of curved barrel parts are achieved, and high-precision and high-quality spiral groove processing are achieved.
Patent Information
- Application Number
- CN202421957938.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-13
- Publication Date
- 2025-06-10
- Estimated Expiration
- 2034-08-13
AI Technical Summary
The existing methods of processing curved barrel parts have problems such as spiral groove deformation, tool interference and cutting vibration, resulting in poor machining accuracy and quality.
Design a butterfly malfunctioning tooth pressing clamp, which adopts the mandrel positioning and the butterfly pressing ring inclined into the lens barrel to avoid applying axial compression force above the parts and ensures no interference in processing.
Reliable compression and interference-free processing of parts are achieved, the machining accuracy and quality of the spiral groove are improved, tool interference and cutting vibration are reduced, and processing efficiency is improved.
Smart Images
Figure CN222958070U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of tooling fixtures, and particularly relates to a butterfly-shaped staggered-tooth pressing fixture for machining curved cylinder parts. Background Technique
[0002] Curved cylinder parts are widely used in continuous optical zoom systems. Most of these parts are key components of optical zoom systems. In order to achieve a certain degree of automatic continuous zoom, several spiral grooves are usually machined on the circumference of cylindrical parts such as lens barrels. Moreover, the machining accuracy requirements of the spiral grooves are very high. Therefore, no axial force can be applied during the clamping of the parts, otherwise the machining accuracy cannot be guaranteed.
[0003] The existing machining method usually adopts a mandrel positioning method on a horizontal machining center, with slight pressing at the upper end, and milling multiple spiral grooves in rough and finish machining. However, there are the following problems with such a machining method:
[0004] (1) Multiple spiral grooves are distributed on the circumferential side wall of the lens barrel, and the starting angles of most of them exceed 180°. After machining, the pressing force applied to the upper end of the curved cylinder part will be damaged, causing the part to deform and loosen, resulting in part scrapping.
[0005] (2) When pressing with a lower-end edge pressing plate, due to the interference of the pressing position of the pressing plate, the tool cannot be fed during machining, and the pressing position of the pressing plate needs to be changed multiple times and the feed needs to be paused midway. The pauses during machining will leave tool marks on the side walls of the precision spiral grooves, resulting in out-of-tolerance surface roughness.
[0006] (3) At the same time, due to the interference of the pressing plate, in order to avoid the pressing plate on the lower end face, the length of the tool needs to be increased, which reduces the tool rigidity, and cutting vibration will occur during machining, affecting the machining accuracy and quality.
[0007] Therefore, it is urgent to design a tooling fixture that is more suitable for machining curved cylinder parts, so as to better machine the spiral grooves on the circumferential surface of curved cylinder parts. Content of the Utility Model
[0008] In view of the above situation, the utility model provides a butterfly-shaped staggered-tooth pressing fixture for machining curved cylinder parts, which presses on the bottom step of the curved lens barrel with a staggered-tooth butterfly pressing ring, can ensure the reliable pressing of the part and interference-free machining, and avoid the deformation of the spiral groove caused by applying axial pressing force above the part.
[0009] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0010] A butterfly-shaped staggered-tooth pressing fixture for machining curved cylindrical parts, comprising a workpiece body to be machined and a tooling fixture for positioning and clamping the workpiece body onto a machine tool workbench. The workpiece body is a vertical cylindrical part, and an annular outward convex upper step surface and a lower step surface are respectively fixed at its upper and lower ends. The tooling fixture consists of a positioning mandrel and a butterfly-shaped pressing ring that are cooperatively and tightly screwed together. The positioning mandrel is coaxially and fixedly connected from top to bottom by a mandrel part, a tightening part, and a base part with gradually increasing diameters. Both the mandrel part and the tightening part are vertical circular columnar structures, and the base part is a circular disc-shaped structure. A stepped diameter surface is provided at the connection between the mandrel part and the tightening part of the positioning mandrel, and an external thread is provided on the outer side wall of the upper end of the tightening part. During the machining operation, the workpiece body is coaxially sleeved outside the mandrel part of the positioning mandrel and placed above the stepped diameter surface of the positioning mandrel. The butterfly-shaped pressing ring includes a circular tightening pressing ring and three butterfly-shaped claws fixedly connected at intervals. An internal thread matching the external thread is provided on the inner side wall of the tightening pressing ring. The inner ends of the three butterfly-shaped claws extend radially inward along the tightening pressing ring and exceed the inner circular surface of the tightening pressing ring for pressing the lower step surface of the workpiece body.
[0011] Preferably, the positioning mandrel is a machined part formed integrally, and its mandrel part, tightening part, and base part are all machined by turning a solid round steel.
[0012] Further, two U-shaped notches are symmetrically provided on the outer peripheral edge of the base part, facilitating the clamping and fixing of the positioning mandrel onto the machine tool workbench using bolts.
[0013] Preferably, two ratchet-shaped notches are symmetrically provided on the outer peripheral surface of the tightening pressing ring, facilitating the forward tightening or reverse loosening of the tightening pressing ring using a hook wrench.
[0014] Further, the two notches are respectively located between two of the three butterfly-shaped claws of the tightening pressing ring, and the three butterfly-shaped claws of the tightening pressing ring are in a completely symmetric structure as a whole.
[0015] The present utility model further includes other components that enable its normal use, all of which are conventional means in the art. In addition, for the devices or components not defined in the present utility model, the existing technologies in the art are adopted.
[0016] The beneficial effects of the present utility model are as follows:
[0017] The butterfly-shaped staggered-tooth pressing fixture for machining curved cylindrical parts provided by the present utility model uses mandrel positioning, and the butterfly-shaped pressing ring is obliquely sleeved into the lens barrel and screwed tightly with the thread on the mandrel to press the lower step of the curved cylinder, thereby pressing the lower end surface of the part against the positioning surface to ensure that no clamping force is applied to the upper part of the spiral groove.
[0018] The thickness of the three clamping claws of the butterfly tooth ensures reliable clamping force and effectively avoids tool interference during machining. There is no need to increase the tool length any more. The shortening of the tool length increases the tool rigidity and greatly improves the machining efficiency.
[0019] Clamped once on a horizontal machining center, rough machining and finish machining are adopted in the process to machine multiple precision spiral grooves, and the machining quality is detected to be stable and reliable. Moreover, this clamping fixture is easy to operate, quick and reliable to clamp, with stable processability and high yield. Brief Description of the Drawings
[0020] Figure 1 It is a front view structural schematic diagram of the curve cylinder part to be machined in the embodiment.
[0021] Figure 2 It is Figure 1 a top view structural schematic diagram of the curve cylinder part in
[0022] Figure 3 It is Figure 2 a sectional structural schematic diagram of the curve cylinder part along the C-C direction in
[0023] Figure 4 It is a front view structural schematic diagram of the positioning mandrel of the tooling fixture in the embodiment.
[0024] Figure 5 It is Figure 4 a sectional structural schematic diagram of the positioning mandrel along the A-A direction in
[0025] Figure 6 It is Figure 4 a top view structural schematic diagram of the positioning mandrel in
[0026] Figure 7 It is a top view structural schematic diagram of the butterfly pressing ring of the tooling fixture in the embodiment.
[0027] Figure 8 It is Figure 7 a sectional structural schematic diagram of the butterfly pressing ring along the B-B direction in
[0028] Figure 9 It is an overall three-dimensional structural schematic diagram of clamping the curve cylinder part to the tooling fixture in the embodiment.
[0029] Figure 10 It is Figure 9 an overall top view structural schematic diagram of the curve cylinder part and the tooling fixture in
[0030] Figure 11 It is Figure 10 a sectional structural schematic diagram along the D-D direction in Detailed Implementation Modes
[0031] The technical solution of the present utility model will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only partial embodiments of the present utility model, rather than all embodiments.
[0032] Embodiment
[0033] A butterfly-shaped staggered-tooth clamping fixture for machining curved cylindrical parts includes a workpiece body 1 to be machined and a tooling fixture for positioning and clamping the workpiece body onto the machine tool worktable (not shown in the figure) of a numerical control machining center. The curved cylindrical parts, the numerical control machining center for machining the curved cylindrical parts, and the machine tool worktable are all prior arts, and their specific settings will not be elaborated here.
[0034] The tooling fixture is designed according to the principle of process concentration to meet the requirements of machining precision curved cylindrical parts. According to the machining process requirements, after the workpiece body of the curved cylindrical part to be machined is clamped onto the tooling fixture, the tooling fixture is then installed onto the machine tool worktable of a horizontal numerical control machining center for precision machining.
[0035] As Figures 1-3 shown, the workpiece body is a vertical cylindrical part, specifically the lens barrel part of an optical zoom device, and upper and lower end stepped surfaces 1-1 and 1-2 with annular outward protrusions are respectively fixedly provided at its upper and lower ends. According to the process requirements, two spiral grooves 1-3 with a width of 4 + 0 0.02 need to be machined on the circumferential side wall of the lens barrel, and the requirements of various geometric tolerances need to be ensured.
[0036] The tooling fixture is composed of a positioning mandrel 2 and a butterfly-shaped pressing ring 3 that are tightly screwed together in cooperation.
[0037] As Figures 4-6 shown, the positioning mandrel is coaxially and fixedly connected from top to bottom by a mandrel part 2-1, a tightening part 2-2, and a base part 2-3 with gradually increasing diameters.
[0038] Both the mandrel part and the tightening part are vertical circular columnar structures, and the base part is a circular disc-shaped structure. A stepped diameter surface 2-4 is provided at the connection between the mandrel part and the tightening part of the positioning mandrel, and external threads are provided on the outer side wall of the upper end of the tightening part. Two U-shaped notches 2-5 are symmetrically provided on the outer peripheral edge of the base part, which is convenient for using bolts to clamp and fix the positioning mandrel onto the machine tool worktable.
[0039] During the processing operation, the workpiece body is coaxially sleeved outside the mandrel part of the positioning mandrel and placed above the stepped diameter surface of the positioning mandrel.
[0040] As Figures 7-8As shown, the butterfly pressure ring includes a circular tightening pressure ring 3-1 and three butterfly claws 3-2 fixedly connected to the tightening pressure ring at annular intervals.
[0041] Two ratchet-shaped bayonet holes 3-3 are symmetrically arranged on the outer peripheral surface of the tightening and pressing ring, so as to facilitate the use of a hook-type spanner to tighten the tightening and pressing ring in a positive direction or to loosen the tightening and pressing ring in a reverse direction.
[0042] The two bayonet holes are respectively located between two of the butterfly claws of the tightening ring, and the three butterfly claws of the tightening ring are completely symmetrical in structure as a whole. The butterfly claw in the middle is a flat key shape, and the other two butterfly claws are symmetrical butterfly wing shapes.
[0043] The size and distribution of the claws allow them to be inserted from the top of the lens barrel part at an angle of 45°, and then tightened with the external threads on the core shaft after being aligned, thereby pressing the upper edge of the step surface at the lower end of the lens barrel to achieve a positive clamping effect.
[0044] An internal thread matching the external thread is provided on the inner side wall of the tightening ring, and the inner ends of the three butterfly claws extend radially inwardly along the tightening ring and exceed the inner circular surface of the tightening ring to tighten the lower end step surface of the workpiece body.
[0045] The positioning mandrel is an integrally formed machined part, and its mandrel part, tightening part and base part are all made by turning solid round steel. It is required to ensure that the matching clearance between the outer cylinder of the Φ28 positioning mandrel and the lens barrel is controlled within 0.02 mm, and the lower end is processed with an M45X1.5 external tightening thread for tightening with a butterfly pressure ring to complete the tightening of the lens barrel parts.
[0046] Use the outer circle and the lower end face of the positioning core shaft to position, insert the butterfly pressure ring at an angle of 45° from the top of the lens barrel part, and tighten the lens barrel part with the external thread on the core shaft after alignment. During the tool setting process of the horizontal machining center, the processing of the spiral groove at the lower end can avoid the initial position of the clamping claw as the tool setting point and the zero point of the machine tool rotary table, and complete the processing of the part by rough and fine milling.
[0047] Through the positioning of the precision lens barrel mandrel, the butterfly pressure ring is inserted into the lens barrel at an angle, and tightened with the thread on the mandrel to press the lower end step of the curve barrel, thereby applying pressure to the lower end surface of the part on the positioning surface to ensure that the upper end part of the spiral groove is not subject to any clamping force.
[0048] The thickness of the three claws of the butterfly gear effectively avoids the interference of the tool during processing. The fixture achieves accurate positioning, reliable clamping, guaranteed processing accuracy without interference, and solves the problem of deformation of spiral groove clamping during processing of curved tube parts.
[0049] The specific processing steps of the utility model are as follows:
[0050] like Figures 9-11 As shown, the curved lens barrel part is inserted into the positioning mandrel and positioned with the outer circle and lower end surface of the Φ28 positioning mandrel. After installation, the matching clearance between the curved lens barrel parts is required to be less than 0.02 mm.
[0051] Tilt the butterfly pressure ring 45° and insert it from the top of the lens barrel part. Then straighten the butterfly pressure ring and tighten it with the M45X1.5 external thread on the positioning mandrel. Use the three butterfly claws to cooperate with each other to press the lower end step surface of the lens barrel part, and make sure the pressing force is moderate.
[0052] Then determine the zero point of the rotary table of the horizontal machining center. Through trial cutting and dry running, the processing of the lower end spiral groove can avoid the initial position of the claw as the cutting point, thereby determining the zero point of the rotary table.
[0053] After completing the clamping and positioning of the curved tube parts and the fixtures, use the horizontal machining center to compile a program for rough and fine milling and high-speed cutting to complete the processing of two precision spiral grooves in one process.
[0054] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. Without departing from the scope and spirit of the described embodiments, many modifications and changes are obvious to ordinary technicians in this technical field. Any technical deformation made within the spirit and principles of the present invention falls within the protection scope of the present invention.
Claims
1. A butterfly-shaped staggered-tooth clamping fixture for processing curved cylindrical parts, comprising a workpiece body to be processed, and a fixture for positioning and clamping the workpiece body on a machine tool workbench, wherein the workpiece body is a vertical cylindrical part, and an annular convex upper end step surface and a lower end step surface are respectively fixed at the upper and lower ends thereof, and characterized in that: The tooling fixture consists of a positioning core shaft and a butterfly pressure ring that are pressed and screwed together with each other. The positioning core shaft consists of a core shaft part, a tightening part and a base part with gradually increasing diameters, which are coaxially fixed from top to bottom. The core shaft part and the tightening part are both vertical circular columnar structures, and the base part is a circular disc-shaped structure. A reducing step surface is provided at the connection between the core shaft part and the tightening part of the positioning core shaft, and an external thread is provided on the outer side wall of the upper end of the tightening part; the butterfly pressure ring includes a circular tightening pressure ring, and three butterfly claws fixed to the tightening pressure ring at annular intervals, an internal thread matching the external thread is provided on the inner side wall of the tightening pressure ring, and the inner end parts of the three butterfly claws extend inwardly along the radial direction of the tightening pressure ring and exceed the inner circular surface of the tightening pressure ring.
2. The butterfly-shaped staggered-tooth clamping fixture for processing curved tube parts according to claim 1 is characterized in that: The positioning mandrel is a machined part formed in one piece from solid round steel.
3. The butterfly-shaped staggered-tooth clamping fixture for processing curved tube parts according to claim 2 is characterized in that: Two U-shaped notches are symmetrically provided on the outer peripheral edge of the base portion, so as to facilitate the use of bolts to clamp and fix the positioning mandrel onto the machine tool workbench.
4. The butterfly-shaped staggered-tooth clamping fixture for processing curved tube parts according to claim 1 is characterized in that: Two ratchet-shaped bayonet holes are symmetrically arranged on the outer peripheral surface of the tightening and pressing ring, so as to facilitate the use of a hook-type spanner to tighten the tightening and pressing ring in a positive direction or to loosen the tightening and pressing ring in a reverse direction.
5. The butterfly-shaped staggered-tooth clamping fixture for processing curved tube parts according to claim 4 is characterized in that: The two bayonet holes are respectively located between two butterfly-shaped claws of the tightening pressure ring.