CN-121979093-A - On-line adjusting method for crank clearance in marine crankshaft machining

Abstract

The invention discloses a marine crankshaft measurement and adjustment method based on dynamic priority and multi-support cooperative decoupling, and belongs to the technical field of high-end equipment manufacturing. Aiming at the problems of low adjustment efficiency and insufficient precision caused by complex structure and support coupling effect in the processing of an asymmetric large-scale marine crankshaft, the invention provides the following innovation that 1. A dynamic priority adjustment strategy dynamically calculates the adjustment priority of each journal according to the swing gear difference (delta S) and the runout quantity (delta) detected in real time and preferentially processes the journal in a high-risk area, and 2. A multi-support cooperative decoupling control is realized by modeling a rigidity influence matrix to realize the accurate decoupling of multiple support displacement quantities and eliminate the coupling deformation.

Inventors

• LI SHIMIN
• SHEN CHI

Assignees

• 江苏新恒鼎装备制造有限公司

Dates

Publication Date

20260505

Application Date

20260202

Claims (3)

1. 1. The method for measuring the conditions of the large marine crankshaft based on the cooperative decoupling of the dynamic priority and the multiple supports is characterized by comprising the following steps of: Step one, detecting the swing gear difference (delta S) and the jumping quantity (delta) of each journal in real time, and calculating a dynamic priority index Is shown as a formula (1); Wherein, delta S is the gear-throwing difference and reflects the radial offset of the journal, the coaxiality of the crankshaft is directly influenced, delta is the runout, the circumferential non-uniformity of the journal is represented, the rotation balance is influenced, alpha and beta are weight coefficients of the gear-throwing difference and the runout respectively, and the importance degree of the gear-throwing difference and the runout is represented. Step two, setting a threshold value th Comparing priority index And the magnitude of the threshold value, when ≥ th And when the high-risk journal is judged to be the high-risk journal, the journal is preferentially regulated, and the threshold value can be dynamically regulated according to the actual process requirement. Step three, constructing an asymmetric rigidity influence matrix The interaction of the decoupled multi-support modulation is shown in equation (2): Where k mn is the stiffness influence coefficient, representing the stiffness contribution of the bearing point m to the journal n, delta Represents the adjustment displacement amount delta of the supporting point m Is the throw difference of journal n. Calculating displacement delta of each supporting point 1 ,Δ 2 ,Δ 3 。 Predicting deformation delta S pre in the next few seconds based on the measurement signal of the sensor, and generating a feedforward compensation instruction, wherein the feedforward compensation instruction is shown in a formula (3): In the formula, Representing the predicted step-out difference, K p ,K d is the proportional and differential coefficients respectively, And predicting the change rate of the gear throwing difference. And fifthly, executing closed-loop adjustment until the swing gear difference of each journal is less than or equal to 0.01mm and the jumping amount is less than or equal to 0.03mm.
2. 2. The method according to claim 1, wherein in the first step, if a journal Δ The current sequence is immediately interrupted and the journal is preferentially adjusted upon a sudden increase to 150% of the set threshold.
3. 3. The method of claim 1, wherein the stiffness matrix in step three Through experimental calibration, the calibration method comprises fixing other supporting points, adjusting the support m independently, measuring the deformation delta S of the journal n, and calculating =Δ /Δ 。

Description

On-line adjusting method for crank clearance in marine crankshaft machining Technical Field The invention belongs to the technical field of marine crankshaft precision machining, and particularly relates to a method and a system for adjusting dynamic priority and multi-support cooperative decoupling of an asymmetric large marine crankshaft, which are suitable for efficient and high-precision machining of a large marine diesel engine crankshaft. Background The traditional large-scale marine crankshaft machining and detection adopts fixed sequence point-by-point adjustment (such as 1# to 2# to 3# to 4# to 5# to 6 #), and has the defects that the traditional large-scale marine crankshaft machining and detection cannot respond to sudden deformation to cause error accumulation due to the fact that the traditional large-scale marine crankshaft machining and detection adopts the fixed sequence adjustment, the single point adjustment causes secondary deformation of adjacent journals, the efficiency is low, and the finish machining period is as long as 10 days. Although the prior patent (such as CN 202510158999.0) proposes an online detection technology, the problems of multi-support coordination and dynamic optimization are not solved. Disclosure of Invention In order to solve the technical problems in the prior art, the invention provides an adjusting method based on dynamic priority and multi-support cooperative decoupling, and belongs to the technical field of high-end equipment manufacturing. Aiming at the problems of low adjusting efficiency and insufficient precision caused by complex structure and supporting coupling effect in the processing of the asymmetric large-scale marine crankshaft, the invention is realized by the following technical scheme: Step one, detecting the swing gear difference (delta S) and the jumping quantity (delta) of each journal in real time, and calculating a dynamic priority index Is shown as a formula (1); Wherein, delta S is the gear-throwing difference and reflects the radial offset of the journal, the coaxiality of the crankshaft is directly influenced, delta is the runout, the circumferential non-uniformity of the journal is represented, the rotation balance is influenced, alpha and beta are weight coefficients of the gear-throwing difference and the runout respectively, and the importance degree of the gear-throwing difference and the runout is represented. Step two, setting a threshold valueth Comparing priority indexAnd the magnitude of the threshold value, when≥th And when the high-risk journal is judged to be the high-risk journal, the journal is preferentially regulated, and the threshold value can be dynamically regulated according to the actual process requirement. Step three, constructing an asymmetric rigidity influence matrixThe interaction of the decoupled multi-support modulation is shown in equation (2): Where k mn is the stiffness influence coefficient, representing the stiffness contribution of the bearing point m to the journal n, delta Represents the adjustment displacement amount delta of the supporting point mIs the throw difference of journal n. Calculating displacement delta of each supporting point1,Δ2,Δ3。 Predicting deformation delta S pre in the next few seconds based on the measurement signal of the sensor, and generating a feedforward compensation instruction, wherein the feedforward compensation instruction is shown in a formula (3): In the formula, Representing the predicted step-out difference, K p,Kd is the proportional and differential coefficients respectively,And predicting the change rate of the gear throwing difference. And fifthly, executing closed-loop adjustment until the swing gear difference of each journal is less than or equal to 0.01mm and the jumping amount is less than or equal to 0.03mm. Further, stiffness matrixThrough experimental calibration, the calibration method comprises fixing other supporting points, adjusting the support m independently, measuring the deformation delta S of the journal n, and calculating=Δ/Δ。 Further, in the predictive compensation control, the K p scaling factor and the K d differential factor can be adjusted by the fuzzy adaptive rule. Compared with the prior art, the invention has at least the following beneficial effects or advantages: the invention provides an adjusting method based on dynamic priority and multi-support cooperative decoupling, which solves the problems of adjusting hysteresis, coupling interference and low detection efficiency, improves the detection precision and enhances the robustness of a system. Drawings The invention will be described in further detail below with reference to the accompanying drawings: FIG. 1 is a flow chart of a method of adjusting based on dynamic priority and multi-support cooperative decoupling according to the present invention. FIG. 2 is a schematic illustration of a large marine crankshaft measurement. Detailed Description Taking a six-cylinder crankshaf