Cam circular interpolation single-sided machining method for precision rotary table

Abstract

This invention belongs to the field of axial offset single-sided machining technology, and in particular, it is a cam circular interpolation single-sided machining method for precision turntables. The method includes the following steps: determining the initial contact state between the cam and the roller; adjusting the center distance L between the cam and the turntable to achieve single-sided contact between the cam and the roller; wherein, in the initial state, the cam and the roller have no contact, and the center distance adjustment formula is: L = L0 - ΔL; This invention, by introducing a dynamic error compensation formula and combining it with precise control of the circular interpolation motion trajectory, can adjust the contact state between the tool and the roller in real time, compensating for errors such as wear and thermal deformation during machining. In the finishing stage, by dynamically adjusting the tool diameter and offset, the single-sided contact error between the cam profile and the roller can be effectively reduced, which is a significant improvement over traditional methods, and significantly improves the motion stability and positioning accuracy of the turntable.

Description

Technical Field

[0001] This invention relates to the field of machining technology for axial offset single-sided wheels, and more particularly to a cam circular interpolation single-sided machining method for precision turntables. Background Technology

[0002] In the manufacturing of precision rotary tables, the cam, as a core transmission component, directly affects the rotary table's motion smoothness, positioning accuracy, and reliability due to its machining precision. Traditional cam machining methods suffer from the following technical defects, making it difficult to meet the stringent requirements of high-precision rotary tables: In existing technologies, cam machining typically employs static compensation or empirical correction methods, which cannot dynamically adjust the contact state between the tool and the roller in real time. Traditional machining methods are not only affected by factors such as tool wear and machine tool thermal deformation, but also fail to achieve 100% conformity to the theoretical surface. This leads to excessive vibration and positioning repeatability errors during turntable movement, making it difficult to meet the core requirements of high-precision turntables for smooth movement and accurate positioning.

[0003] Traditional methods often employ a single-parameter, two-stage "roughing → finishing" approach, lacking dynamic optimization of the cutting process. For example, in the roughing stage, high cutting forces are often used to maximize efficiency, leading to excessive surface waviness; in the finishing stage, to ensure quality, feed rates need to be reduced, resulting in a high proportion of idle travel time and long single-piece machining cycles. This contradiction between efficiency and quality severely restricts the large-scale production efficiency of high-precision rotary tables.

[0004] In existing technologies, the contact design between cams and rollers is mostly fixed, supporting only a single specification of machining requirements. When changing cams or rollers of different specifications, it is necessary to manually adjust the machine tool center distance, change the fixture, and even reprogram the process parameters, resulting in increased equipment downtime. Therefore, to address the above problems, a cam circular interpolation single-sided machining method for precision rotary tables is proposed. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art and solve at least one of the technical problems mentioned in the background art, the present invention proposes a single-sided machining method for cam circular interpolation of precision rotary tables.

[0006] The technical solution adopted by this invention to solve its technical problem is: a single-sided machining method for cam circular interpolation of a precision turntable, comprising the following steps: determining the initial contact state between the cam and the roller, and adjusting the center distance L between the cam and the turntable to achieve single-sided contact between the cam and the roller; wherein, in the initial state, the cam and the roller have no contact, and the center distance adjustment formula is:

[0007] In the formula, The initial center distance, To adjust the amount, ensure that the cam contacts the roller on only one side.

[0008] Preferably, the method includes the following steps: identifying the actual working surface of the cam, wherein the actual working surface is the right side surface of the left half of the cam. The left curved surface of the right half of the cam During processing, only the surface accuracy of the actual contact portion needs to be guaranteed. The surface equation is expressed as:

[0009] Where f and g are surface functions.

[0010] Preferably, the process includes the following steps: When machining the right-side curved surface, the tool is offset by a distance d in the y-direction so that the tool is tangent to the right side of the roller, and the offset distance d satisfies the formula:

[0011] In the formula, Where is the roller radius, The diameter of the cutting tool. The radius of the cam profile.

[0012] Preferably, the method includes the following steps: the tool rotates at a constant speed around a rotation center, with a rotation angle of θ, while the tool rotation center performs circular interpolation motion, the trajectory formula of which is:

[0013] In the formula, R is the circular interpolation radius, ω is the angular velocity, Φ is the initial phase, λ is the attenuation coefficient, t is the time variable, and d is the offset distance in the y direction.

[0014] Preferably, the process includes the following steps: during finishing, the tool size is kept equal to the roller diameter, i.e. = And an error compensation formula is used to optimize machining accuracy:

[0015] In the formula, The compensation coefficient is n, where n is the current number of processing operations and N is the total number of processing operations.

[0016] Preferably, the process includes the following steps: A step-by-step processing method is adopted, gradually reducing the offset d(t) in the y-axis direction to narrow the processing range from both ends of the cam towards the center; the dynamic adjustment formula for the offset is:

[0017] In the formula, t is the initial bias, μ is the decay rate, and t is the processing time.

[0018] Preferably, the process includes the following steps: during the rough machining of the left curved surface, the center distance is set to... The diameter of the cutting tool is It satisfies the formula:

[0019] In the formula, α is the difference in roughing radius on the left, m is the current number of machining steps, and M is the total number of steps.

[0020] Preferably, the method includes the following steps: during the rough machining of the right curved surface, the center distance is set to... The diameter of the cutting tool is It satisfies the formula:

[0021] In the formula, β is the difference in roughing radius on the right, m ​​is the current number of machining steps, and M is the total number of steps.

[0022] Preferably, the process includes the following steps: during the finishing of the right curved surface, the center distance is adjusted to... The diameter of the cutting tool is And fix the tool rotation center offset to the left by a distance Δx, satisfying the formula:

[0023]

[0024] In the formula, γ and δ are dynamic adjustment coefficients.

[0025] Preferably, the process includes the following steps: during the finishing of the left curved surface, the offset is reduced to zero, i.e. =0, adjust the center distance to The diameter of the cutting tool is It satisfies the formula:

[0026]

[0027] In the formula, The final adjustment is given by ζ and η, which are optimization coefficients, and T is the total processing time.

[0028] Compared with the prior art, the present invention provides a single-sided machining method for cam circular interpolation of precision rotary tables, which has the following beneficial effects: This precision rotary table uses a cam circular interpolation single-sided machining method. By introducing a dynamic error compensation formula and combining it with precise control of the circular interpolation motion trajectory, the contact state between the tool and the roller can be adjusted in real time to compensate for errors such as wear and thermal deformation during the machining process. In the finishing stage, by dynamically adjusting the tool diameter and offset, the single-sided contact error between the cam profile and the roller can be effectively reduced, which is a significant improvement over traditional methods and significantly improves the motion stability and positioning accuracy of the rotary table.

[0029] This precision rotary table employs a cam circular interpolation single-sided machining method. By adopting a "step-by-step machining + dynamic offset" strategy and combining phased parameter adjustments for roughing and finishing, it achieves a smooth transition from both ends to the center. This method reduces idle travel time, shortens the machining cycle of a single cam, and avoids surface waviness problems caused by sudden changes in cutting force in traditional methods by controlling the cutting force in stages.

[0030] This precision rotary table employs a cam-based circular interpolation single-sided machining method. Through its single-sided contact design and dynamic center distance adjustment formula, it is compatible with rollers and cams of different specifications, eliminating the need for frequent fixture changes or machine parameter adjustments. Furthermore, the formulaic parameter control reduces reliance on operator skills, significantly improving the stability of mass production, making it particularly suitable for fields with extremely high reliability requirements, such as aerospace and semiconductor equipment. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the machining process for a single-sided cam circular interpolation machining method for a precision rotary table proposed in this invention. Figure 2 This is a schematic diagram of the initial state of the precision rotary table and cam assembly in the single-sided machining method of cam circular interpolation for a precision rotary table proposed in this invention. Figure 3 This is a schematic diagram showing the comparison between the center distance between the cam and the roller before and after adjustment in a single-sided machining method for cam circular interpolation of a precision rotary table proposed in this invention. Figure 4 This is a schematic diagram of the actual working surface of the cam in the single-sided machining method of cam circular interpolation for a precision rotary table proposed in this invention; Figure 5This is a schematic diagram of the tool offset and cutting contact relationship during the machining of the right curved surface in a single-sided machining method for cam circular interpolation of a precision rotary table proposed in this invention. Figure 6 This is a schematic diagram of the circular interpolation motion trajectory of the tool rotation center in a single-sided machining method using a cam circular interpolation for a precision rotary table proposed in this invention. Figure 7 This invention provides a dynamic compensation curve for the tool diameter during the finishing stage of a single-sided machining method using cam circular interpolation for precision rotary tables. Figure 8 This invention provides an adjustment curve for the difference in the radii of the left and right curved surfaces during the roughing stage of a single-sided machining method for a precision rotary table using cam circular interpolation. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example like Figures 1-8 As shown, one embodiment of the present invention proposes: A specific implementation method for a single-sided machining method using cam circular interpolation for a precision rotary table: In the initial state, the cam and roller are not in contact. The center distance L between the cam and the turntable is adjusted by the CNC system using the following formula:

[0035] Among them, the initial center distance Set to 250mm, adjustment amount Calculated based on the roller diameter (e.g., 30mm) and cam design parameters, for example, taking... =18mm, then after adjustment the center distance L=232mm, ensuring that the cam and roller achieve single-sided contact.

[0036] In this invention, the actual working surface of the cam, including the right side surface of the left half, is identified using 3D modeling software. and the left curved surface of the right half During processing, only the actual contact surface is machined with high precision. The surface equation is obtained through reverse engineering fitting, for example: (Right half of the curved surface) During processing, only regions satisfying y≥0 are processed.

[0037] In this invention, when machining the right-side curved surface, the offset distance d of the tool in the y-direction is calculated using the following formula:

[0038] Taking a roller diameter of 30mm, a cutter diameter of 16mm, and a cam profile radius of 50mm as an example, we calculate that d=7.4mm so that the cutter is tangent to the right side of the roller.

[0039] In this invention, the tool rotates at a constant speed by an angle θ around the rotation center, while the tool rotation center performs circular interpolation motion, and the trajectory formula is:

[0040] Set the circular interpolation radius R=20mm, angular velocity ω=2πrad / s, initial phase Φ=0, and attenuation coefficient λ=0.5 to achieve smooth interpolation motion.

[0041] In this invention, during finishing, the diameter of the cutting tool is equal to the diameter of the roller, that is... = =30mm, and the error compensation formula is used:

[0042] Set compensation coefficient =0.001, current machining count n=5, total machining count N=10, dynamically adjust tool diameter to compensate for wear.

[0043] In this invention, during step-by-step processing, the dynamic adjustment formula for the bias d(t) is:

[0044] initial bias =10mm, attenuation rate μ=0.2, processing time t increases from 0 to 10 seconds, the offset gradually decreases to zero, realizing the processing transition from both ends to the center.

[0045] In this invention, during the rough machining of the left curved surface, the center distance... =232mm, tool diameter =16mm, the radius difference formula is: Set the roughing radius difference on the left side =-7.4mm, adjustment coefficient α=0.1, current step m=3, total steps M=6, gradually adjust the processing parameters.

[0046] In this invention, during the rough machining of the right-side curved surface, the center distance... =232mm, tool diameter =16mm, the radius difference formula is:

[0047] Set the roughing radius difference on the right side =7.4mm, adjustment coefficient β=0.15, current step m=2, total steps M=5, optimize processing path.

[0048] In this invention, the center distance adjustment formula is as follows during the finishing of the right curved surface:

[0049] set up =2mm, dynamic adjustment coefficient γ=0.3, processing time t=5 seconds, center distance gradually adjusted to =230mm; the offset formula is: Cutting tool diameter =30mm, adjustment coefficient δ=0.05, to achieve precise offset.

[0050] In this invention, during the finishing of the left curved surface, the offset amount =0, the center distance adjustment formula is: Set the final adjustment amount =1mm, optimization coefficient ζ=0.4, processing time t=8 seconds, center distance adjusted to =229mm; the formula for tool diameter is: Set the optimization coefficient η=0.02 and the total processing time T=10 seconds to ensure processing accuracy.

[0051] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for single-sided machining of a cam-based circular interpolation system for a precision rotary table, characterized in that, Includes the following steps: Determine the initial contact state between the cam and the roller. Adjust the center distance L between the cam and the turntable to achieve unilateral contact between the cam and the roller. Initially, there is no contact between the cam and the roller; the center distance adjustment formula is: ； In the formula, The initial center distance, To adjust the amount, ensure that the cam contacts the roller on only one side.

2. The method for single-sided machining of a cam circular interpolation for a precision rotary table according to claim 1, characterized in that, Includes the following steps: Identify the actual working surface of the cam, which is the right side surface of the left half of the cam. The left curved surface of the right half of the cam During processing, only the surface accuracy of the actual contact portion needs to be guaranteed. The surface equation is expressed as: ； Where f and g are surface functions.

3. The method for single-sided machining of a cam circular interpolation for a precision rotary table according to claim 1, characterized in that, Includes the following steps: When machining the right-side curved surface, the tool is offset by a distance d in the y-direction so that the tool is tangent to the right side of the roller. The offset distance d satisfies the formula: ； In the formula, Where is the roller radius, The diameter of the cutting tool. The radius of the cam profile.

4. The method for single-sided machining of a cam circular interpolation for a precision rotary table according to claim 3, characterized in that, Includes the following steps: The tool rotates at a constant speed around its rotation center at an angle of θ. Simultaneously, the tool's rotation center undergoes circular interpolation motion, the trajectory of which is formulated as follows: ； In the formula, R is the circular interpolation radius, ω is the angular velocity, Φ is the initial phase, λ is the attenuation coefficient, t is the time variable, and d is the offset distance in the y direction.

5. The method for single-sided machining of a cam circular interpolation for a precision rotary table according to claim 1, characterized in that, The process includes the following steps: During finishing, the tool size is kept equal to the roller diameter, i.e. = And an error compensation formula is used to optimize machining accuracy: ； In the formula, The compensation coefficient is n, where n is the current number of processing operations and N is the total number of processing operations.

6. The method for single-sided machining of a cam circular interpolation for a precision rotary table according to claim 1, characterized in that, The process includes the following steps: A step-by-step machining method is adopted, gradually reducing the y-axis offset d(t) to narrow the machining range from both ends of the cam towards the center; the dynamic adjustment formula for the offset is: ； In the formula, t is the initial bias, μ is the decay rate, and t is the processing time.

7. The method for single-sided machining of a cam circular interpolation for a precision rotary table according to claim 1, characterized in that, Includes the following steps: When rough machining the left curved surface, set the center distance to [value]. The diameter of the cutting tool is It satisfies the formula: ； In the formula, α is the difference in roughing radius on the left, m is the current machining step number, and M is the total number of steps.

8. The method for single-sided machining of a cam circular interpolation for a precision rotary table according to claim 1, characterized in that, Includes the following steps: When rough machining the right-side curved surface, set the center distance to... The diameter of the cutting tool is It satisfies the formula: ； In the formula, β is the difference in roughing radius on the right, m ​​is the current number of machining steps, and M is the total number of steps.

9. A single-sided machining method for cam circular interpolation of a precision rotary table according to claim 1, characterized in that, Includes the following steps: When finishing the curved surface on the right side, adjust the center distance to... The diameter of the cutting tool is And fix the tool rotation center offset to the left by a distance Δx, satisfying the formula: ； ； In the formula, γ and δ are dynamic adjustment coefficients.

10. A single-sided machining method for cam circular interpolation of a precision rotary table according to claim 1, characterized in that, Includes the following steps: During the finishing of the left curved surface, the offset is reduced to zero, i.e. =0, adjust the center distance to The diameter of the cutting tool is It satisfies the formula: ； ； In the formula, The final adjustment is given by ζ and η, which are optimization coefficients, and T is the total processing time.

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