阅读说明：本技术 一种机床服役周期能效潜力获取方法 (A kind of lathe military service period efficiency potentiality acquisition methods ) 是由 庹军波 刘培基 陈山 谢俊 于 2019-09-26 设计创作，主要内容包括：本发明公开了一种机床服役周期能效潜力获取方法：步骤1：测量待测机床运行过程中的基础能耗数据；步骤2：根据基础能耗数据,建立机床能耗信息描述函数；步骤3：调研与待测机床相同型号的机床在典型代表性生产过程中的运行数据；步骤4：分别拟合待测机床未来服役周期的主轴转速分布与各进给轴的进给速度分布,进而建立相应的概率密度函数；步骤5：拟合待测机床切削功率分布,进而建立切削功率分布的概率密度函数；步骤6：估算待测机床服役周期中各状态时间占比；步骤7：计算机床服役周期能效潜力。本发明能够有效地预测机床未来服役阶段的能量效率,对高能效机床设计和机床采购阶段能效评估均具有重要支撑作用。(The invention discloses a kind of lathe military service period efficiency potentiality acquisition methods: step 1: measuring the basic energy consumption data in lathe operational process to be measured；Step 2: according to basic energy consumption data, establishing lathe consumption information described function；Step 3: operation data of the lathe of investigation and lathe same model to be measured in typical representative production process；Step 4: the feed speed of the speed of mainshaft distribution and each feed shaft that are fitted the military service period in lathe future to be measured respectively is distributed, and then establishes corresponding probability density function；Step 5: being fitted machine cut power distribution to be measured, and then establish the probability density function of cutting power distribution；Step 6: estimating each state for time accounting in the lathe military service period to be measured；Step 7: calculating lathe military service period efficiency potentiality.The present invention can effectively predict the energy efficiency in military service stage in lathe future, all have important support effect to high energy efficiency Machine Tool design and lathe acquisition phase energy efficiency evaluation.)

The period efficiency potentiality acquisition methods 1. a kind of lathe is on active service, which comprises the following steps:

Step 1: measuring the basic energy consumption data in lathe operational process to be measured, including lathe standby power, the speed of mainshaft at different levels Under main shaft starting energy consumption, the main shaft rotary power under the speed of mainshaft at different levels and the feeding shaft power under feed speeds at different levels；

Step 2: according to the basic energy consumption data of measurement, establishing lathe consumption information described function, including main shaft starts energy consumption letter Number, main shaft rotary power function, feed shaft feed power function；

Step 3: investigation obtains the operation data with the lathe of lathe same model to be measured in typical representative production process, packet Include the various processing under the feed speed frequency of use at different levels of speed of mainshaft frequency of use at different levels and feed shaft, the speed of mainshaft at different levels Task machined parameters, available machine time, main shaft starting time, main shaft rotational time, feeding time and cutting time；

Step 4: according to speed of mainshaft frequency of use at different levels and feed shaft in the frequency of use of feed speeds at different levels, being united using mathematics Meter and data fitting method are fitted the speed of mainshaft distribution in military service period in lathe future to be measured and the feeding speed of each feed shaft respectively Degree distribution, so that the probability that the feed speed of the probability density function and each feed shaft of establishing speed of mainshaft distribution respectively is distributed is close Spend function；The probability density function of speed of mainshaft distribution is dependent variable using probability using the speed of mainshaft as independent variable, the speed of mainshaft； The probability density function of feed speed distribution is dependent variable using probability using feed speed as independent variable, feed speed；

Step 5: according to the machined parameters under processing tasks various under the speeds of mainshaft at different levels, calculating the cutting under various processing tasks Power；According to the main shaft rotary power of the minimum speed of lathe to be measured and spindle motor rated power, cutting for lathe to be measured is determined Cut power bracket；Cutting power range is divided into several subintervals, counts every according to the cutting power under various processing tasks The frequency of use in a subinterval, and machine cut power to be measured is fitted according to the frequency of use in each subinterval and is distributed, to build The probability density function that the vertical cutting power using cutting power as independent variable, cutting power probability of occurrence for dependent variable is distributed；

Step 6: when starting time, main shaft rotational time, feeding according to the available machine time in the operation data of investigation acquisition, main shaft Between and the cutting time, estimate lathe to be measured be on active service in the period main shaft starting time, main shaft rotational time, the feeding time and Ratio of the cutting time relative to the available machine time, i.e. main shaft starting time accounting, main shaft rotational time accounting, feeding time account for Than, cutting time accounting；

Step 7: the description indexes of selecting machine tool military service period efficiency potentiality, according to the function model of the description indexes, and The data of above-mentioned measurement and fitting calculate lathe military service period efficiency potentiality.

The period efficiency potentiality acquisition methods 2. lathe according to claim 1 is on active service, which is characterized in that the description indexes For complex energy utilization rate, complex energy utilization rate refers to the ratio of cutting power and input power during lathe military service；It is comprehensive The function model for closing capacity usage ratio U is as follows:

In formula, P_sbIndicate standby power, P_cIndicate cutting power, E_st(n) indicate that main shaft starts energy consumption function, P_r(n) master is indicated Axis rotary power function, P_f(f) feed shaft feed power function is indicated；i_TstIndicate that main shaft starts time accounting, i_TcIndicate cutting Time accounting, i_TnIndicate main shaft rotational time accounting, i_TfIndicate feeding time accounting；C(P_c) it is the probability that cutting power is distributed Density function, C (n) are the probability density function of speed of mainshaft distribution；C (f) is the probability density function of feed speed distribution.

The period efficiency potentiality acquisition methods 3. lathe according to claim 1 is on active service, which is characterized in that lathe in step 2 The creation of consumption information described function includes following characteristics: main shaft starting energy consumption letter is obtained under the speeds of mainshaft at different levels in measurement On the basis of main shaft starts energy consumption, starting energy consumption as independent variable, main shaft using the speed of mainshaft is dependent variable, it is primary obtained by fitting or Person's quadratic function；Main shaft rotary power function is to be turned on the basis of measurement obtains revolving speed main shaft rotary power at different levels with main shaft Speed is independent variable, main shaft rotary power is dependent variable, carries out primary or quadratic function obtained by data fitting；Feed shaft feeding Power function is on the basis of measurement obtains feeding shaft power, is dependent variable by independent variable, feeding shaft power of feed speed, Carry out linear function obtained by data fitting.

The period efficiency potentiality acquisition methods 4. lathe according to claim 1 is on active service, which is characterized in that step 4 and step 5 It is middle using Poisson distribution, be uniformly distributed, Gamma distribution or just too distribution carry out data fitting.

The period efficiency potentiality acquisition methods 5. lathe according to claim 1 is on active service, which is characterized in that speed of mainshaft distribution Independent variable section be [n_s,n_e], and meet the following conditions:

n_min≤n_s< n_m< n_e≤n_max；

In formula, n_minFor the minimum speed of mainshaft of lathe, n_maxRevolving speed, n are used for lathe highest_mFor the most frequently used revolving speed of lathe.

The period efficiency potentiality acquisition methods 6. lathe according to claim 1 is on active service, which is characterized in that various processing tasks Under cutting power be calculated as follows:

For there is the lathe of specific cutting power empirical formula, acquisition is directly calculated according to corresponding empirical equation；

For the lathe of not specific cutting power empirical formula, carried out according to following general-cutting power function model It calculates and obtains:

P_c'=MRR*k；

In formula, P_c' for the cutting power under certain specific processing tasks, MRR is material removal rate, and k is proportionality coefficient.

The period efficiency potentiality acquisition methods 7. lathe according to claim 1 is on active service, which is characterized in that by such as in step 6 Under type estimates cutting time accounting and feeding time accounting: since machine tool chief axis starts the time and idle time is usually very short, And cutting process generally entails feeding process, therefore, the cutting time and feeding the time be approximately main shaft rotational time, cutting Time accounting and feeding time accounting are approximately main shaft rotational time accounting.

Technical field

The invention belongs to be machined the efficiency potentiality acquisition of manufacturing technology field more particularly to a kind of lathe military service period Method.

Background technique

Lathe has a large capacity and a wide range, and energy consumption total amount is huge, and capacity usage ratio is low, and potential of energy efficiency improvement is very big；Therefore, lathe Efficiency research significance is great.Compared to ordinary electrical home appliance product, lathe is a kind of equipment that the military service period is relatively long, is on active service the period Refer to lathe duration for scrapping or transfer the possession of to lathe since factory, for example, a center lathe CA6140 maintenance compared with Usually up to more than 60 years under conditions of good, lathe whole life cycle energy consumption is primarily generated at lathe and is on active service the period, usually Occupy 80% or more (ISO 14955).The energy consumption research in lathe military service period has become the important of lathe efficiency research Component part.

Originally, masschusetts, U.S.A Polytechnics professor Gutowski D 2006 international production engineering association (CIRP) just It points out the significance of machine tooling operational process energy consumption research, and analyzes the master of power consumption during machine cut Want influence factor.Later, the research of lathe energy efficiency is rapidly growing in the world like the mushrooms after rain, for example, Australia is new The Kara S professor team of southern University of Wales analyzes the resource consumption feature in grinding machine process, and proposes a kind of mill Process Energy efficiency evaluation method is cut, while the energy that also studied constant power consumable components in machine cut process disappears Consumption feature and power-economizing method；The Domfeld D professor team of Univ California-Berkeley has studied lathe energy consumption Automatic monitoring method, milling process energy consumption feature and Energy Saving Strategy；Domestic University Of Chongqing Liu Fei teaches team pair Energy consumption model, the energy efficiency of machining system are obtained and are assessed, the efficiency optimization in workpiece process carries out Research；There are also the Tang Zhongren professors of the Sutherland WJ of Purdue Univ-West Lafayette USA professor team, Zhejiang University for similar team Team etc..These researchs are mainly from academic paper angle, to the energy consumption feature of some specific process and optimization It is studied.

In addition, the research about lathe energy efficiency also progresses into domestic and international patent protection and standard formulation scope. Invention disclosed patent CN102621932A discloses a kind of energy consumption computation model of numerically-controlled machine tool military service process, from starting Period, unloaded period and processing period angle set out and introduce the energy consumption computation model of machining；Published invention is special Sharp " lathe multi-source energy consumption system multi information on-line detecting system " (CN103941081A) carries out machine using multiple power sensors The energy consumption on-line checking of the various energy sources of bed completes machine cut and adds by integrating the energy consumption of each energy source The energy consumption on-line checking of work process.In the world, Russ P (RU2135343C1) discloses a kind of metal cutting process The energy consumption power-economizing method of process carries out realizing that machine cut adds especially by the friction reduced between cutter and workpiece or cutting The power-economizing method of work process.United States Patent (USP) (US7289873B2) discloses a kind of energy sensor-based system for measuring metal cutting The energy consumption of lathe, the sensor-based system by install multiple sensors realize Metal Cutting Machine Tool cut energy consumption measurement and It obtains.

In terms of standard formulation, Japanese Standards Association (JIA) has formulated " Machine tools e test methods For electric power consumption " (JIS TS B 0024-1:2010) standard, for measuring machining center, number Control the energy consumption test of the various types lathe such as lathe and turning center, cylindrical grinder；Comite Internationale de Normalisation (ISO) " the machine tools--environmental evaluation of of ISO 14955 about machine tool environment assessment is formulated Machine tools " series standard, including for carrying out lathe energy-saving design guidance ISO 14955-1:2017, for branch Support the ISO 14955-2:2018 of machine tool assembly energy consumption measurement method and for supporting what Metal Cutting Machine Tool efficiency measured The standards such as ISO 14955-3:2019.Also " machining manufacturing process efficiency key foundation Data Detection side is being formulated in China Method ", " machining manufacturing process energy efficiency evaluation method ", " machining manufacturing process workpiece energy consumption limit formulating method " Etc. relevant criterions, wherein " machining manufacturing process efficiency key foundation data detection method " and " be machined manufacturing process Energy efficiency evaluation method " has been set up the project, and the stage of consulting on is currently under.

The above-mentioned energy consumption about lathe military service process science and technical research mainly for some specific period, Or in the energy efficiency of lathe some specific work pieces process；However, since lathe is a kind of stronger production equipment of versatility, Its following processing tasks is ever-changing, and energy consumption and energy efficiency are even more multifarious, therefore, certain above-mentioned operational process or certain The energy efficiency of work pieces process is difficult to represent lathe and is entirely on active service the energy efficiency potentiality in stage, so that Machine Tool design person and management Person can not accurately predict that lathe is entirely on active service the energy efficiency in period, be that consumer in the acquisition phase carries out lathe Energy Efficiency Ratio Difficulty is brought compared with decision, meanwhile, also for international standard, " ISO 14955-1-2014 lathe-machine tool environment evaluates-the 1 Point: high energy efficiency machine tool design method " implementation bring problem, the standard execute the first step be " general life- cycle assessment”。

Summary of the invention

In view of the above shortcomings of the prior art, the present invention provides a kind of lathe military service period efficiency potentiality acquisition methods, energy The energy consumption in enough effectively prediction military service stages in lathe future, purchases the efficiency optimization design and lathe in Machine Tool design stage Stage energy efficiency evaluation all has important support effect.

In order to solve the above technical problems, technical scheme is as follows: a kind of lathe military service period efficiency potentiality acquisition Method, comprising the following steps:

Step 1: measuring the basic energy consumption data in lathe operational process to be measured, including lathe standby power, main shaft at different levels Main shaft starting energy consumption, the main shaft rotary power under the speed of mainshaft at different levels and the feeding shaft work under feed speeds at different levels under revolving speed Rate；

Step 2: according to the basic energy consumption data of measurement, establishing lathe consumption information described function, including main shaft starts energy Consume function, main shaft rotary power function, feed shaft feed power function；

Step 3: investigation obtains the operation number with the lathe of lathe same model to be measured in typical representative production process According to each under feed speed frequency of use at different levels, the speed of mainshaft at different levels including speed of mainshaft frequency of use at different levels and feed shaft Kind processing tasks machined parameters, available machine time, main shaft starting time, main shaft rotational time, feeding time and cutting time；

Step 4: according to speed of mainshaft frequency of use at different levels and feed shaft in the frequency of use of feed speeds at different levels, utilizing number Learn statistics and data fitting method, be fitted respectively lathe future to be measured be on active service the period speed of mainshaft distribution and each feed shaft into To VELOCITY DISTRIBUTION, to establish the general of the feed speed distribution of the probability density function and each feed shaft of speed of mainshaft distribution respectively Rate density function；The speed of mainshaft distribution probability density function using the speed of mainshaft as independent variable, the speed of mainshaft using probability be because Variable；The probability density function of feed speed distribution is dependent variable using probability using feed speed as independent variable, feed speed；

Step 5: according to the machined parameters under processing tasks various under the speeds of mainshaft at different levels, calculating under various processing tasks Cutting power；According to the main shaft rotary power of the minimum speed of lathe to be measured and spindle motor rated power, lathe to be measured is determined Cutting power range；Cutting power range is divided into several subintervals, is united according to the cutting power under various processing tasks The frequency of use in each subinterval is counted, and machine cut power to be measured is fitted according to the frequency of use in each subinterval and is distributed, from And establish the probability density letter that the cutting power using cutting power as independent variable, cutting power probability of occurrence for dependent variable is distributed Number；

Step 6: according to investigation obtain operation data in available machine time, main shaft starting the time, main shaft rotational time, into To time and cutting time, estimate lathe to be measured be on active service in the period main shaft starting time, main shaft rotational time, the feeding time, And ratio of the cutting time relative to the available machine time, i.e. main shaft start time accounting, main shaft rotational time accounting, feeding time Accounting, cutting time accounting；

Step 7: selecting machine tool is on active service the description indexes of period efficiency potentiality, according to the function model of the description indexes, And the data of above-mentioned measurement and fitting, calculate lathe military service period efficiency potentiality.

Further, the description indexes are complex energy utilization rate, and complex energy utilization rate refers to lathe military service process The ratio of middle cutting power and input power；The function model of complex energy utilization rate U is as follows:

In formula, P_sbIndicate standby power, P_cIndicate cutting power, E_st(n) indicate that main shaft starts energy consumption function, P_r(n) table Show main shaft rotary power function, P_f(f) feed shaft feed power function is indicated；i_TstIndicate that main shaft starts time accounting, i_TcIt indicates Cutting time accounting, i_TnIndicate main shaft rotational time accounting, i_TfIndicate feeding time accounting；C(P_c) it is cutting power distribution Probability density function, C (n) are the probability density function of speed of mainshaft distribution；C (f) is the probability density letter of feed speed distribution Number.

Further, step 4 in step 5 use Poisson distribution, be uniformly distributed, Gamma distribution or just too distribution counted According to fitting.

Further, the independent variable section of speed of mainshaft distribution is [n_s,n_e], and meet the following conditions:

n_min≤n_s< n_m< n_e≤n_max；

In formula, n_minFor the minimum speed of mainshaft of lathe, n_maxRevolving speed, n are used for lathe highest_mFor the most frequently used revolving speed of lathe.

Further, cutting power refers to process increased power demand due to material removal, generally includes material Power and additional load loss power are removed, since additional load loss power is smaller, therefore cutting power is approximately material removal Cutting power under the various processing tasks of power is calculated as follows:

For there is the lathe of specific cutting power empirical formula, is directly calculated and obtained according to corresponding empirical equation It takes；

For the lathe of not specific cutting power empirical formula, according to following general-cutting power function model Carry out calculating acquisition:

P_c'=MRR*k；

In formula, P_c' for the cutting power under certain specific processing tasks, MRR is material removal rate, and k is proportionality coefficient.

Investigate and estimate lathe be on active service during main shaft starting time accounting, main shaft rotational time accounting, feeding the time account for Than having the feature that choosing typical representative production process can be one day, a week or one when, cutting time accounting Month；Available machine time is that lathe opens power supply to the duration closed during power supply, and it is the speed of mainshaft from zero to mesh that main shaft, which starts the time, Marking institute between revolving speed, time-consuming, and main shaft rotational time is the duration that runs under rotating speed of target of main shaft, the cutting time be cutter with Workpiece contacts and carries out the duration that machining is consumed, and the feeding time is feed system duration in operating status；Main shaft opens Dynamic time accounting, main shaft rotational time accounting, feeding time accounting, cutting time accounting are the typical representative production process phase Between main shaft start the time, main shaft rotational time, cutting time, feeding the time respectively with the ratio of available machine time.

Further, cutting time accounting and feeding time accounting are estimated in step 6 as follows: due to machine tool chief axis Start the time and idle time be usually very short, and cutting process generally entails feeding process, therefore, the cutting time and the feeding time Being is approximately main shaft rotational time；Cutting time accounting and feeding time accounting are equal to main shaft rotational time accounting.

Compared with prior art, the invention has the following advantages:

1, lathe of the invention be on active service period efficiency potentiality be entirely be on active service towards lathe the stage complex energy consumption and Energy efficiency and the concept proposed.Ever-changing processing tasks are to lathe energy consumption during the present invention fully considers lathe military service It influences, by being split to lathe energy consumption composition, fitting of distribution, the processes such as remerging, establishes military service stage efficiency potentiality Model and obtaining step, the energy consumption in the lathe following entire stage of being on active service can be effectively predicted, to the Machine Tool design stage Efficiency optimization design and lathe acquisition phase energy efficiency evaluation all have important support effect.

2, the big factor of efficiency far-reaching three during the present invention is for the first time on active service to lathe, the i.e. speed of mainshaft, feeding speed The distribution of degree, cutting power is studied；And by utilizing data statistics and probability theory method, a kind of lathe military service is established The acquisition methods that period revolving speed is distributed using distribution, feed speed using distribution and cutting power.

Detailed description of the invention

Fig. 1 is the flow chart of lathe military service period efficiency potentiality acquisition methods；

Fig. 2 is the power curve schematic diagram in hobbing process；

Fig. 3 is main shaft starting energy consumption function curve diagram；

Fig. 4 is main shaft rotary power function curve diagram；

Fig. 5 is feed shaft feed power function curve diagram；

Fig. 6 is the probability density function curve graph of speed of mainshaft distribution；

Fig. 7 is the probability density function curve graph of Z axis feed speed distribution；

Fig. 8 is the probability density function curve graph of cutting power distribution.

Specific embodiment

Using the prediction technique of lathe provided by the present invention military service period efficiency potentiality, referring to process as shown in Figure 1 Figure, is tested the military service period efficiency potentiality of YS3118CNC5 chain digital control gear hobbing machine, detailed process is as follows:

Step 1: the basic energy consumption data of lathe operational process to be measured is measured

Standby power refers to that lathe opens the power demand to lathe during main shaft start-up course from main power switch, works as tool When there are multiple discrete values, take from standby power value measured by the nearest at the time of point of main shaft Startup time；Main shaft starts energy consumption Energy consumed by axis system during referring to machine tool chief axis from zero speed to rotating speed of target；Main shaft rotary power refers to that lathe is run Power demand for maintaining main shaft to rotate, also referred to as spindle power in the process；Feeding shaft power is used during referring to machine tool feed In the power demand for maintaining feed system movement, also referred to as empty feed power；The meaning of each parameter is referring to attached drawing 2.

By in-site measurement, standby (running comprising the hydraulic system) power of YS3118CNC5 chain digital control gear hobbing machine is 3.11kW。

Through investigating, the normal revolution section of YS3118CNC5 chain digital control gear hobbing machine is 100~1000r/min, therefore, to this turn The starting energy consumption and main shaft rotary power in fast section are measured, and the results are shown in Table 1.In hobbing process, Z axis direction of feed For main work direction of feed, therefore select Z axis as representing, in common feed speed range (frequency of use is higher than 80%) Z axis feed power measured, measurement result is shown in Table 2.

Main shaft starting energy consumption and main shaft rotary power under the revolving speed at different levels of table 1.

Z axis system feed power under the feed speed at different levels of table 2

Z axis feed speed (mm/min)	100	200	300	400	500	600	700	800
									Z axis system feed power (kW)	0.058	0.122	0.182	0.186	0.201	0.223	0.295	0.356

Step 2: lathe consumption information described function to be measured is established

Present case uses quadratic function and is fitted to main shaft starting energy consumption, sees Fig. 3；I.e. main shaft starts energy consumption function Are as follows:

E_st(n)=5.26 × 10^-6n²+1.67×10^-3n+0.59,n∈[100,1000] (1)

Present case uses linear function and is fitted to main shaft rotary power, sees Fig. 4；That is main shaft rotary power function Are as follows:

P_r(n)=1.95 × 10^-3N+0.15, n ∈ [100,1000] (2)

Present case uses linear function and is fitted to Z axis feed power, sees Fig. 5；That is Z axis system feed power letter Number are as follows:

P_f(f_v)=3.68*10^-4f_v+ 0.037, f_v∈[100,900] (3)

Step 3: operation data of the lathe of investigation and lathe same model to be measured in typical representative production process

Typical representative production process can be a shift, one day, a week or one month.Available machine time is lathe Open power supply to close power supply during duration, main shaft starting the time by the speed of mainshaft from zero to rotating speed of target time-consuming Long, main shaft rotational time is the duration that main shaft is first run in current revolving speed, and the cutting time is that cutter is contacted and cut with workpiece It cuts and processes consumed duration, the feeding time is feed system duration in operating status；Main shaft starts time accounting, main shaft rotation Turn main shaft during time accounting, feeding time accounting, cutting time accounting are the typical representative production process and starts the time, it is main Axis rotational time, cutting time, feeding the time respectively with the ratio of available machine time.

It is prosperous at, Chongqing Shen Jiansijia gear manufacture enterprise by investigation Chongqing orchid black pigment used by women in ancient times to paint their eyebrows, Chongqing autumn fields, Chongqing, it obtains YS3118CNC5 normal revolution section [100,200], (200,300], (300,400], (400,500], (500,600], (600,700], (700,800], (800,900], (900,1000] frequency of use of (r/min) is respectively 0.007,0.035, 0.181,0.239,0.299,0.212,0.013,0.011,0.003；Similarly, Z axis system common feed speed section [100, 200], (200,300], (300,400], (400,500], (500,600], (600,700], (700,800], (800,900] (mm/min) frequency of use is respectively 0.122,0.228,0.313,0.163,0.097,0.054,0.022,0.001.

In batch production process, single Gear Processing averagely takes around 3min (random investigation Chongqing orchid black pigment used by women in ancient times to paint their eyebrows, Chongqing mind arrow Two enterprise production process estimations obtain), it is calculated according to a shift 8h, removes noon 2h, averagely to produce 120 gears.It presses According to each gear stand-by time 5s, main shaft starts time 1s.

Step 4: revolving speed and the feed speed distribution in lathe military service period to be measured are fitted

Based on above-mentioned investigational data, using just too distribution carry out the speed of mainshaft and Z axis feed system feed speed be distributed into The probability density C (f) of the fitting of row data, the probability density function C (n) and the distribution of Z axis feed speed that obtain speed of mainshaft distribution divides Shown in cloth such as following formula (4) and formula (5), specific fit procedure is shown in Fig. 6 and 7 respectively.

Step 5: it is fitted the cutting power distribution in lathe military service period to be measured

According to the machined parameters under the various processing tasks of the speeds of mainshaft at different levels and various processing tasks, various processing are calculated Cutting power under task；According to the rotary power and spindle motor rated power under lathe minimum speed to be measured, determine to be measured The cutting power range of lathe；Cutting power range is divided into several subintervals, according to the cutting power under various processing tasks Rate counts the frequency of use in each subinterval, and is fitted machine cut power point to be measured according to the frequency of use in each subinterval Cloth, so that it is close to establish the probability that the cutting power using cutting power as independent variable, cutting power using probability for dependent variable is distributed The motor rated power for spending function machine tool chief axis is 7.5kw, and the rotary power under minimum speed 100 is 0.295kW, therefore maximum is cut Cutting power is 7.5-0.295=7.205kW, and the cutting power range of lathe selected by present case is [0,7.205] (kW), in investigation Enterprise is stated, lathe is as shown in table 3 in the load distribution of the cutting power range.

The distribution of 3 cutting power of table

According to above-mentioned investigational data, the probability density of the lathe military service period cutting power distribution of just too fitting of distribution is carried out Shown in function such as formula (6), fit procedure is shown in Fig. 8.

Step 6: each operating status time accounting in the lathe military service period to be measured is estimated

Feeding time and cutting time be approximately main shaft rotational time calculate the average shift operation of case lathe when Between be respectively as follows: starting time 2min, stand-by time 10min, main shaft rotational time, feeding the time and the cutting time be 348min.Therefore main shaft starts time accounting 0.006, main shaft rotational time accounting, feeding time accounting and cutting time accounting are equal It is 0.97.

Step 7: based on measurement and fitting data, the efficiency potentiality in lathe military service period to be measured are calculated

By the standby power in step 1, the main shaft in step 2 starts energy consumption function, main shaft rotary power function, Z axis system The speed of mainshaft in system feed power function, step 4 is distributed, cuts in the probability density function of Z axis feed speed distribution, step 5 Cut power distribution probability density function and step 6 in main shaft starting the time account for, main shaft rotational time accounting, feeding when Between accounting and cutting time accounting, bring efficiency potentiality calculation formula into, it is as follows:

In conclusion the efficiency potentiality of YS3118CNC5 chain digital control gear hobbing machine are 26.4%.