阅读说明：本技术 考虑刀具磨损的数控车削批量加工工艺参数节能优化方法 (Numerical control turning batch processing technological parameter energy-saving optimization method considering cutter abrasion ) 是由 李聪波 吕岩 胡曾明 屈世阳 潘建 张友 何吉祥 崔佳斌 余必胜 于 2020-06-19 设计创作，主要内容包括：本发明公开了一种考虑刀具磨损的数控车削批量加工工艺参数节能优化方法,包括以下内容：在分析批量加工过程中刀具磨损和工艺参数协同影响数控车削加工总时间和总能耗机理特性的基础上,以总能耗最低和总时间最短为目标,以不同刀具磨损下的工艺参数集合为变量,建立考虑刀具磨损的数控车削批量加工工艺参数节能优化模型,采用优化算法进行优化求解。然后基于具体实例,进行多目标优化仿真,实现数控车削批量加工中高生产效率与高能源效率之间的平衡,可用于指导企业实际生产。(The invention discloses a numerical control turning batch processing process parameter energy-saving optimization method considering cutter abrasion, which comprises the following steps: on the basis of analyzing the mechanism characteristics that the total time and the total energy consumption of numerical control turning are influenced by tool wear and process parameters in a cooperative mode in the batch processing process, an energy-saving optimization model of the numerical control turning batch processing process parameters considering the tool wear is established by taking the minimum total energy consumption and the shortest total time as targets and taking process parameter sets under different tool wear as variables, and an optimization algorithm is adopted for optimization solution. And then, based on a specific example, multi-objective optimization simulation is carried out, so that the balance between high production efficiency and high energy efficiency in the numerical control turning batch processing is realized, and the method can be used for guiding the actual production of an enterprise.)

1. The numerical control turning batch processing technological parameter energy-saving optimization method considering cutter abrasion is characterized by comprising the following steps of:

on the basis of analyzing the mechanism characteristics that the total time and the total energy consumption of numerical control turning are influenced by tool wear and technological parameters in a cooperative mode in the batch machining process, an energy-saving optimization model of the numerical control turning batch machining technological parameters considering tool wear is established by taking the minimum total energy consumption and the shortest total time as targets, and optimization solution is carried out by adopting an optimization algorithm.

2. The numerical control turning batch processing process parameter energy-saving optimization method considering tool wear according to claim 1, characterized in that: the technological parameters influence cutter abrasion, the technological parameters and the cutter abrasion jointly influence processing energy consumption and processing time, and the numerical control turning batch processing technological parameter energy-saving optimization method considering the cutter abrasion is characterized in that the cutter abrasion is considered in numerical control processing to adjust the technological parameters to realize balance between the processing time and the processing energy consumption; the following assumptions need to be met for adjusting parameters in time for the wear state of the tool to achieve the goals of minimum total energy consumption and minimum time for machining:

1) one batch is processed on one machine tool without being interrupted by other processing tasks, and the cutter for processing the batch can not process other kinds of workpieces;

2) neglecting dimensional and manufacturing errors between each workpiece;

3) errors caused by a production manufacturing process, a machining environment, worker operation and the like to a machining process and a cutter abrasion rule are ignored;

4) each tool task T_jThe processing is started by a new cutter;

5) each tool task tool changing standard is VB_max；

6) The technological parameter standard of each replacement is [ delta VB/delta t ].

3. The numerically controlled turning batch processing process parameter energy-saving optimization model considering tool wear according to claim 1, characterized in that: the method for establishing the multi-objective optimization model comprehensively considering the tool wear and the process parameters by taking the minimum total energy consumption and the minimum total time of the batch processing as the multi-objective in claim 1 comprises the following steps:

defining a batch processing task as a main task T, wherein a workpiece set I of the main task T is { I ═ I_l1, 2, …, N, and a tool set U is U_u1, 2, …, V, and VB_maxOne process parameter set is X (v)_c，f，a_p|VB_jp) The parameter change standard is [ delta VB/delta t]；

In the main task T, a tool U is used_jMachining, defined as tool task T_jAt tool task T_jFirstly, the technological parameter X is used_j(v_c，f，a_p)＝{X_jp(v_c，f，a_p|VB_jp)|p＝1，2，…，Q_jIs processed, wherein Q_jThe number of the technological parameters used in the tool task is [ delta VB/delta t ]]_jp≥[ΔVB/Δt]When, the replacement process parameter is X_j(p+1)(v_c，f，a_p|VB_j(p+1)) When it is VB_j≥VB_maxWhile changing the cutter U_j+1Processing is carried out;

(1) decision variables

The method comprises the following steps: considering the state of wear of the tool, the cutting speed v_cFeed speed f, back draft a_pThree parameters are used as optimization variables, and the decision variable array is X (v)_c，f，a_p|VB_jp)＝{X_jp(v_c，f，a_p|VB_jp)|j∈(1，t)，p∈(1，Q_j)}；

(2) Objective function

1) Total energy consumption objective function for batch processing

In the formula: e_totalIs the total energy consumption of the main task T of the machine tool,

2) total time objective function for batch processing

In the formula: t is t_totalIn order to provide a total time for the batch processing,

(3) constraint conditions

1) Process parameter ranges

①v_c-min≤v_c≤v_c-max，v_c-minAnd v_c-maxAllowing minimum and maximum cutting speeds for the machine tool, respectively; and v is_c-jp≥v_c-j(p+1)，v_c-jpIs a process parameter X_jp(v_c，f，a_p|VB_jp) Corresponding to the cutting speed;

②f_min≤f≤f_max，f_minand f_maxAllowing minimum and maximum feed amounts for the machine tool, respectively;

③a_p-min≤a_p≤a_p-max，a_p-minand a_p-maxRespectively allowing minimum and maximum back-cut quantities for the machine tool;

2) threshold value of machine tool performance during machining

④P_c≤ηP_maxη is a machine toolPower efficiency factor, P_maxThe maximum power of the machine tool;

⑤C_F、X_F、Y_F、n_F、K_Ffor the corresponding cutting force influence index, F_cmaxThe maximum cutting force can be provided for the numerical control machine tool;

⑥M_sthe maximum cutting torque allowed by the rigidity of the main shaft;

3) number of workpieces and requirements for surface roughness of the work

⑦

⑧VB≤VB_maxthe abrasion loss of the cutter is within the cutter changing standard;

⑨r₍₎is the radius of the cutting edge, [ R ]_a]The roughness requirement is indicated for the finished workpiece.

4. The numerical control turning batch processing process parameter energy-saving optimization method considering tool wear according to claim 1, characterized in that: and performing optimization solution by using an optimization algorithm, including but not limited to an evolutionary algorithm, and processing by using the optimized processing parameters.

Technical Field

The invention relates to the field of mechanical cutting machining, in particular to a numerical control machining energy consumption prediction energy-saving optimization method.

Background

Numerical control turning batch processing is a very common processing mode in workshop production, and process parameter selection has obvious influence on total energy consumption and processing efficiency in the batch production process. Meanwhile, along with the batch processing, the machine tool cutter can be worn or even damaged, and further the energy consumption of the machine tool is increased and the energy utilization rate is reduced. Therefore, the influence of the process parameters and the tool wear on the numerical control turning batch processing energy consumption and the processing efficiency is considered comprehensively, and the problem to be solved is needed urgently. At present, the research on the wear state and the technological parameters of the cutter mainly aims at analyzing the energy consumption mechanism of a single workpiece machining process, discretizing the wear state of the cutter, and researching the influence of the single specific wear state and the technological parameters on the energy consumption of the machining process. In a large-batch processing process, the wear state of the cutter can be continuously changed along with the processing, and the analysis of the total energy consumption mechanism of the batch processing aiming at the continuous change of the wear state of the cutter is rarely reported, so that the development of the energy consumption model research considering the change of the cutter state and facing the whole batch processing process has important practical significance. Therefore, the method takes numerical control turning batch processing as an example, and researches the problem of optimizing the technological parameters of the numerical control turning batch processing facing energy consumption under the continuous change of the abrasion state of the cutter. Firstly, the system analyzes the mechanism characteristics of the total time and the total energy consumption of the numerical control turning batch processing comprehensively considering the cooperative influence of the cutter abrasion and the process parameters; on the basis, the numerical control turning batch processing process parameter optimization model is established by taking the total batch processing time and the total energy consumption as targets and taking the process parameter sets under different cutter wear as variables.

Disclosure of Invention

The invention provides an energy-saving optimization method for numerical control turning batch processing technological parameters considering cutter abrasion.

The technical scheme adopted for achieving the aim of the invention is that the energy-saving optimization method for the numerical control turning batch processing technological parameters considering the cutter abrasion comprises the following steps:

on the basis of analyzing the mechanism characteristics that the total time and the total energy consumption of numerical control turning are influenced by tool wear and technological parameters in a cooperative mode in the batch machining process, an energy-saving optimization model of the numerical control turning batch machining technological parameters considering tool wear is established by taking the minimum total energy consumption and the shortest total time as targets, and optimization solution is carried out by adopting an optimization algorithm.

Preferably, the technological parameters influence cutter abrasion, the technological parameters and the cutter abrasion jointly influence processing energy consumption and processing time, and the numerical control turning batch processing technological parameter energy-saving optimization method considering the cutter abrasion is characterized in that the cutter abrasion is considered in numerical control processing to adjust the technological parameters to realize balance between the processing time and the processing energy consumption; the following assumptions need to be met for adjusting parameters in time for the wear state of the tool to achieve the goals of minimum total energy consumption and minimum time for machining:

1) one batch is processed on one machine tool without being interrupted by other processing tasks, and the cutter for processing the batch can not process other kinds of workpieces;

2) neglecting dimensional and manufacturing errors between each workpiece;

3) errors caused by a production manufacturing process, a machining environment, worker operation and the like to a machining process and a cutter abrasion rule are ignored;

4) each tool task T_jThe processing is started by a new cutter;

5) each tool task tool changing standard is VB_max；

6) The technological parameter standard of each replacement is [ delta VB/delta t ].

Preferably, the numerical control turning batch processing technological parameter energy-saving optimization model considering cutter abrasion is characterized in that: the process of establishing the multi-objective optimization model comprehensively considering the cutter abrasion and the process parameters by taking the minimum total energy consumption and the minimum total time of the batch processing as the multi-objective is as follows:

defining a batch processing task as a main task T, wherein a workpiece set I of the main task T is { I ═ I_l1, 2, …, N, and a tool set U is U _u1, 2, …, V, and VB_maxOne toolThe technological parameter group is X (v)_c，f，a_p|VB_jp) The parameter change standard is [ delta VB/delta t]；

In the main task T, a tool U is used_jMachining, defined as tool task T_jAt tool task T_jFirstly, the technological parameter X is used_j(v_c，f，a_p)＝{X_jp(v_c，f，a_p|VB_jp)|p＝1，2，…，Q_jIs processed, wherein Q_jThe number of the technological parameters used in the tool task is [ delta VB/delta t ]]_jp≥[ΔVB/Δt]When, the replacement process parameter is X_j(p+1)(v_c，f，a_p|VB_j(p+1)) When it is VB_j≥VB_maxWhile changing the cutter U_j+1Processing is carried out;

(1) decision variables

The method comprises the following steps: considering the state of wear of the tool, the cutting speed v_cFeed speed f, back draft a_pThree parameters are used as optimization variables, and the decision variable array is X (v)_c，f，a_p|VB_jp)＝{X_jp(v_c，f，a_p|VB_jp)|j∈(1，t)，p∈(1，Q_j)}；

(2) Objective function

1) Total energy consumption objective function for batch processing

In the formula: e_totalIs the total energy consumption of the main task T of the machine tool,energy consumption of the acceleration stage is started for each workpiece main shaft,the energy consumption in the idle load stage is the energy consumption,in order to consume energy in the idle cutting stage,in order to consume energy in the cutting stage,the energy consumption of the machine tool in the stage of disassembling and clamping the workpiece,

in order to adjust the energy consumption of the parameter stage,energy consumption is achieved in the tool changing stage for blunting;

energy consumption in tool changing stage of blunt grinding

When the cutter reaches the cutter changing standard VB_maxThe machine tool needs to be stopped for replacing the cutter when the machine tool is required to be stopped, the process of sharpening and changing the cutter comprises cutter detaching, cutter installing and cutter aligning, wherein the machine tool is in a standby state in the cutter detaching and cutter installing stages, and the standby power is P_stThe machine tool is in the idle stage in the tool setting stage, and the idle power of the tool setting is P_u：

Wherein a is₀、a₁、a₂Are the corresponding coefficients;

dull milling cutter changing time is unit dull milling cutter changing time in cutter task T_jThe energy consumption at the blunt tool changing stage is calculated as follows:

wherein:

wherein, t_adtoolFor sharpening the total time of the tool-changing stage, Dint [ A | B ]]Indicating that a or B occurred rounded down.

② energy consumption of parameter adjusting stage

When reaching the parameter changing point [ delta VB/delta t]The process parameter set X needs to be stopped_j(p-1)(v_c，f，a_p|VB_j(p-1)) Adjusting to a process parameter set X_jp(v_c，f，a_p|VB_jp) Processing the next workpiece, and adjusting the parameters while the machine tool is in a standby state with standby power P_stTherefore, the energy consumption in the parameter adjusting stage is as follows:

wherein:

wherein the content of the first and second substances,

the abrasion value when the jth knife is processed by using the pth group of process parameters reaches delta VB/delta t for a variable of 0-1]When the temperature of the water is higher than the set temperature,otherwise

Energy consumption in stage of disassembling and clamping workpiece

When a workpiece is machined, the machine tool is in a standby state, the standby power is P_stTherefore, the energy consumption in the stage of disassembling and clamping the workpiece is as follows:

fourthly, energy consumption of the main shaft in the starting acceleration stage

Every time a workpiece is machined, the main shaft needs to be started and accelerated to the workpiece task T_jpiCorresponding spindle speed n_jpThe main shaft starting acceleration power is as follows:

the time for accelerating the main shaft to the stable rotating speed is as follows:

comprises the following steps:

therefore, the energy consumption of the main shaft in the starting acceleration stage is as follows:

in the formula:v_cfor a set of process parameters X_jp(v_c，f，a_p|VB_jp) The corresponding cutting speed.

Energy consumption in no-load stage

The idle stage comprises two processes of fast feeding of the machine tool and fast retracting of a tool of the machine tool, wherein in the two processes, a main shaft of the machine tool is in an idle state, and the idle power of the main shaft is as follows:

the motion time of the feeding system is short, the feeding power is small and can be ignored, so the energy consumption in the no-load stage is as follows:

energy consumption in blank cutting stage

In the idle cutting stage, the main shaft rotates at a speed n_jpSteady rotation while the feed system is at feed speed f_jpGradually moving towards the workpiece, wherein the idle cutting power is as follows:

therefore, the energy consumption in the no-load stage is as follows:

seventhly, energy consumption in the cutting stage

Cutting phase tool and workpiece surface contact to remove material, for different tool wear states VB_jpDifferent subtasks T_jpSelecting different technological parameter sets X_jp(v_c，f，a_p|VB_jp) Processing the part, and considering that the wear state of the tool is not changed in one workpiece processing time^[9]. Therefore the subtask T_jpCutting power ofIs a technological parameter set X_jp(v_c，f，a_p|VB_jp) And wear extent VB_jpAs a function of (c). At the same time, the additional load power is always generated in the cutting process, and the cutting power

Corresponding additional load power

Comprises the following steps:

therefore, the energy consumption in the cutting stage is as follows:

wherein:

in the formula: uint [ A ]]Rounded up for A, and VB when p is 1_jp＝0；M_jpFrom VB for tool wear value_jpTo VB_j(p+1)The interval is divided into equal parts by taking delta VB as an interval;

for tool wear at [ VB_jp+(m-1)×ΔVB，VB_jp+m×ΔVB]The number of processed pieces therebetween;

in summary, the total energy consumption objective function

Wherein t is_wsrFor stage time of dismantling-clamping work pieces, P_stFor standby power, n_jpThe spindle rotation speed a corresponding to the p sub-task in the jth tool task₀、a₁、a₂For no-load work of tool settingCoefficient of rate response, L_spStarting an accelerating power system structure constant value parameter for a main shaft, wherein t is time,

for the fast movement time of the feeding system,

in order to realize the quick retraction time of the cutter,free cutting distance, f, for the p-th subtask i-th workpiece task of the j-th tool task_jpFor the feed speed, P, corresponding to the P sub-task of the j tool task_auxTo assist system power, N_jpThe number of parts to be machined for the pth subtask of the jth tool task,

the cutting power of the ith workpiece task of the p subtask of the jth tool task, c0 and c1 are corresponding coefficients of additional load power,for tool wear at [ VB_j(p-1)+(m-1)×ΔVB，VB_j(p-1)+m×ΔVB]Number of working pieces in between, t_jpiMachining time, t, for the p-th sub-task of the jth tool task and the ith workpiece task_adparIn order to adjust the parameter phase time,is a variable from 0 to 1, and is,

in order to realize the quick retraction time of the cutter,in order to grind the time for mounting the cutter,

for sharpening tool settingM, T_jTo be cut by a cutter U_jThe task of the tool for the machining is carried out,the cutting time for the jth tool task.

2) Total time objective function for batch processing

In the formula: t is t_totalIn order to provide a total time for the batch processing,in order to dull polish the time for detaching the knife,in order to grind the time for mounting the cutter,for dull tool setting time, t_adparTo adjust the parameter phase time, t_wsrIn order to disassemble and clamp the stage time of the workpiece,starting the acceleration stage time for each workpiece spindle,

for the fast movement time of the feeding system,

in order to realize the quick retraction time of the cutter,in order to realize the time of the idle cutting stage,is the cutting stage time;

(3) constraint conditions

1) Process parameter ranges

①v_c-min≤v_c≤v_c-max，v_c-minAnd v_c-maxAllowing minimum and maximum cutting speeds for the machine tool, respectively; and v is_c-jp≥v_c-j(p+1)，v_c-jpIs a process parameter X_jp(v_c，f，a_p|VB_jp) Corresponding to the cutting speed;

②f_min≤f≤f_max，f_minand f_maxAllowing minimum and maximum feed amounts for the machine tool, respectively;

③a_p-min≤a_p≤a_p-max，a_p-minand a_p-maxRespectively allowing minimum and maximum back-cut quantities for the machine tool;

2) threshold value of machine tool performance during machining

④P_c≤ηP_maxη is the machine power efficiency coefficient, P_maxThe maximum power of the machine tool;

⑤C_F、X_F、Y_F、n_F、K_Ffor the corresponding cutting force influence index, F_cmaxThe maximum cutting force can be provided for the numerical control machine tool;

⑥

M_sthe maximum cutting torque allowed by the rigidity of the main shaft;

3) number of workpieces and requirements for surface roughness of the work

⑦The total number of pieces of processing should be within the batch requirement number;

⑧VB≤VB_maxthe abrasion loss of the cutter is within the cutter changing standard;

⑨

r₍₎is the radius of the cutting edge, [ R ]_a]The roughness requirement is indicated for the finished workpiece.

Preferably, the numerical control turning batch processing technological parameter energy-saving optimization method considering cutter abrasion is characterized in that: and performing optimization solution by using an optimization algorithm, including but not limited to an evolutionary algorithm, and processing by using the optimized processing parameters.

Drawings

FIG. 1 is a schematic view of a batch process

FIG. 2 Power Profile of the machining Process

FIG. 3 tool cutting path diagram

FIG. 4 data acquisition platform

FIG. 5 analysis of tool wear and process parameter significance

FIG. 6 is a drawing of a detail of an end cap and a drawing of an embodiment thereof

FIG. 7 optimization result diagram

Detailed Description

The present invention will be further described with reference to the accompanying drawings and examples, but it should not be construed that the scope of the above-described subject matter is limited to the examples. Various substitutions and alterations can be made without departing from the technical idea of the invention and the scope of the invention is covered by the present invention according to the common technical knowledge and the conventional means in the field.

In the case, a CHK560 numerically controlled lathe produced by a certain machine tool group in Chongqing and a software and hardware integrated machine tool energy efficiency monitoring system independently developed by Chongqing university are taken as platforms, the equipment can acquire and display the total power of the machine tool in real time in the operation process, and simultaneously, a super-depth-of-field three-dimensional microscope system is used for measuring the wear value of the rear tool face of a turning tool, and the data acquisition platform is shown in figure 5.

The Chongqing machine tool is adopted to produce the CHK560 numerical control lathe, the specific parameters are shown in the table 1,

TABLE 1 lathe parameters

An excircle turning tool with the model number of CNMG120412-TMT9125 is adopted, and the specific parameters are shown in Table 2.

TABLE 2 tool parameters

The workpiece is used for acquiring relevant data of the experiment, and specific parameters are shown in Table 3

TABLE 3 part parameters

The optimization model parameter configuration comprises the following steps:

(1) cutting power and parasitic load power fit

Cutting power

With additional load powerThe relationship is complex, and the data is difficult to be extracted independently, so the method is toAndthe fitting is carried out on the whole body,the expression is as follows:

while taking into account the tool wear value pair

The influence is the tool wear VB and the process parameters (cutting speed vc, feed f, back bite ap)Each factor sets three levels. The details are shown in Table 4.

TABLE 4 cutting power and additional load power factor level table

The L27(34) orthogonal table with a large number of tests is selected for carrying out the experiment, and the experimental result is shown in the table 5, whereinThe power of the machine tool in the idle time period,for the cutting period of the machine tool, thenComprises the following steps:

TABLE 5 cutting Power and parasitic load Power test results

Cutting power taking into account tool wear

The expression is as follows:

to obtain finallyThe expression is as follows:

(2) machine tool no-load power coefficient acquisition

The machine tool spindle is in an idle state, the idle rotation speed N of the machine tool and the corresponding idle power Pu are recorded, and the experimental result is shown in table 6.

TABLE 6 main shaft idle speed and corresponding idle power

The no-load power expression obtained by fitting is as follows:

(3) tool wear time-varying data acquisition

Fig. 5 is a result of analyzing influence of three process parameters on tool wear, wherein one process parameter is set to be a fixed value in sequence, and influence of the remaining two process parameters on tool wear is analyzed. As can be seen from the figure, under the same processing conditions, the cutting speed has the greatest influence on the tool wear, and the feeding speed and the back-cut amount are the second factor among the three process parameters; therefore, when the feed speed and the back-cut amount are small, the variation in the wear characteristics of the tool is mainly affected by the cutting speed.

Ten sets of cutting speeds (vc is 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, unit m/min) are selected, each set of cutting speeds starts to cut a workpiece by using a new cutter under the same cutting conditions, and cutter wear values are measured at the same time interval delta t, so that time and wear values corresponding to parameter change under each set of cutting speeds are obtained, and are shown in table 7.

TABLE 7 Point Change for Point wear and time

(4) Processing information configuration

Table 8 shows the configuration of machining information such as standby power and auxiliary system power during the cutting process.

TABLE 8 Process information parameter configuration

The experimental environment is adopted to finish the batch processing of the excircle of the bearing end cover shown in fig. 6, and the processing process is the first step of processing the part, namely 45 steel, which is counted by 2000. The model is solved by Matlab, FIG. 7 is a result graph of the synthetic optimization of Etotal & ttotal and the individual optimization of Etotal and ttotal in the processing process, and comparative analysis is shown in Table 9

TABLE 9 comparative analysis results

From the optimization results of fig. 7 and table 9, the following points can be found:

(1) the total time of the individual optimization of ttotal is reduced by 7.17 percent and the total energy consumption is increased by 29.75 percent compared with the comprehensive optimization of Etotal & ttotal.

(2) The total energy consumption of the individual optimization Etotal is reduced by 22.16 percent and the total time is increased by 9.74 percent compared with the comprehensive optimization Etotal & ttotal.

Therefore, the balance between high production efficiency and high energy efficiency in the numerical control turning batch processing is realized through multi-objective optimization, the enterprise is facilitated to pursue and select a more flexible production solution according to different objectives in actual production, and the method has important guiding significance for the sustainable development of the enterprise.

The energy-saving optimization method provided by the invention adjusts the process parameters according to the wear state of the cutter in the batch processing process, thereby prolonging the service life of the cutter, reducing the use number of the cutter, reducing the total processing time, simultaneously enabling the cutter to process more workpieces in a low wear area, and effectively reducing the consumption of the total energy. Compared with a fixed process parameter processing method, the variable process parameter batch processing considering the cutter abrasion has higher energy efficiency and processing efficiency.