Energy saving method of spindle deceleration in no-load process between adjacent cutting activities of CNC machine tool

Abstract

An energy saving method of spindle deceleration in a no-load process between adjacent cutting activities of a CNC machine tool is provided. The spindle speed during no-load operation of the CNC machine tool is decreased but not stopped, to reduce the energy consumption in the no-load process of the machine tool, so as to improve the energy utilization rate of the machine tool, while at the same time avoiding the loss service life of a main transmission system and motor caused by frequent start and stop of the machine tool.

Description

ENERGY SAVING METHOD OF SPINDLE DECELERATION IN NO-LOAD PROCESS BETWEEN ADJACENT CUTTING ACTIVITIES OF CNC MACHINE TOOL Technical Field The present invention belongs to the technical field of mechanical manufacture, and particularly relates to an energy saving method of spindle deceleration in a no-load process between adjacent cutting activities of a CNC machine tool. Background As a main energy consumption and carbon emission in the mechanical manufacturing industry, a CNC machine tool plays a critical role in energy saving and emission reduction. Meanwhile, a large number of research results indicate that the average energy utilization rate of machine tool equipment is low, and is less than 30% on average. Thus, the exploration of the energy saving problem of machine tool equipment has very important theoretical guidance significance and practical application value, and is conducive to the smooth promotion of energy saving and emission reduction of the mechanical manufacturing industry. Because the CNC machine tool has a no-load movement process of feeding, retracting and changing during workpiece processing, a machine tool main transmission system is not in a processing state at this time, which is a process of complete waste of energy and also one of the main reasons for low energy utilization rate of the machine tool equipment. Thus, the invention patent disclosed by CN200810070302.0 and titled "an energy-saving implementation method of shutdown during no-load operation between adjacent process steps of a CNC machine tool" discloses an energy-saving method of shutdown during no-load operation of a CNC machine tool. The method uses a mode of stopping and restarting to reduce the time and the energy consumption of the machine tool during no-load operation in the mechanical manufacturing process, so as to achieve the purpose of energy saving. The invention patent disclosed by CN202011128991.3 and titled "method for determination of energy saving critical time of spindle shutdown of a CNC machine tool and energy saving" provides an energy saving method of spindle shutdown during no-load operation of a CNC machine tool, and can accurately calculate the critical time and the energy saving effect of spindle shutdown energy saving according to the initial speed and the target speed of a spindle. Although the above energy saving methods in the no-load operation process of the CNC machine tool can achieve the effect of energy saving regardless of machine tool shutdown energy saving or spindle shutdown energy saving, in the actual processing operation of a workshop, the frequent start and stop of the machine tool may have a certain impact on the machine tool main transmission system and a machine tool motor, and even may affect the service life. The energy saving effect at the cost of sacrificing the service life of the machine tool doesn't pay. Therefore, in view of the problem of energy waste in the no-load operation process of the CNC machine tool, there is still a lack of an effective energy saving solution. Summary To solve the above technical problem, the present invention proposes an energy saving method of spindle deceleration in a no-load process between adjacent cutting activities of a CNC machine tool. The spindle speed during no-load operation of the CNC machine tool is decreased to reduce the energy consumption in the no-load process of the machine tool, so as to improve the energy utilization rate of the machine tool, and thus avoid the loss of the main transmission system and the motor caused by frequent start and stop of the machine tool. To achieve the above purpose, the present invention provides an energy saving method of spindle deceleration in a no-load process between adjacent cutting activities of a CNC machine tool, comprising: collecting spindle state speed and no-load interval time between adjacent cutting activities; acquiring the energy consumption of the CNC machine tool in each motion state; acquiring energy consumption of the machine tool in a no-load motion process and energy consumption when a spindle deceleration strategy is implemented based on the spindle state speed and the energy consumption of the CNC machine tool in each motion state; presetting energy saving prerequisites; acquiring the energy saving critical time of spindle deceleration after the energy consumption of the machine tool in the no-load motion process, the energy consumption when the spindle deceleration strategy is implemented and the no-load interval time satisfy the energy saving prerequisites; and conducting spindle deceleration in a no-load interval when the no-load interval time is greater than the energy saving critical time of spindle deceleration. Further, the spindle state speed comprises: initial spindle speed, target spindle speed and spindle speed after deceleration. Further, the energy consumption of the CNC machine tool in each motion state comprises: the energy consumption of a machine tool foundation module, the energy consumption of a machine tool spindle in constant-speed rotation motion and the energy consumption of the machine tool spindle in accelerating motion; the energy consumption of the machine tool foundation module is: [Image disponible dans le document PDF, Image available in the PDF document] wherein <com:Math><semantics>Estandby<annotation encoding="application / x-tex">E_{standby}< / annotation>< / semantics>< / com:Math> is the energy consumption of the machine tool foundation module, <com:Math><semantics>Pstandby<annotation encoding="application / x-tex">P_{standby}< / annotation>< / semantics>< / com:Math> is a power when the operation of the machine tool foundation module is maintained, <com:Math><semantics>Pstandbyi<annotation encoding="application / x-tex">P_{standby_i}< / annotation>< / semantics>< / com:Math> is a power value of the machine tool foundation module collected at an ith time by an experimental device, N is the number of data collection, and <com:Math><semantics>Tstandby<annotation encoding="application / x-tex">T_{standby}< / annotation>< / semantics>< / com:Math> is a time for maintaining the operation of the machine tool foundation module. the energy consumption of the machine tool spindle in constant-speed rotation motion is: [Image disponible dans le document PDF, Image available in the PDF document] wherein <com:Math><semantics>Espindle<annotation encoding="application / x-tex">E_{spindle}< / annotation>< / semantics>< / com:Math> is the energy consumption of the machine tool spindle in constant-speed rotation motion, <com:Math><semantics>Pspindle<annotation encoding="application / x-tex">P_{spindle}< / annotation>< / semantics>< / com:Math> is the power of the machine tool spindle in constant-speed rotation motion, <com:Math><semantics>n<annotation encoding="application / x-tex">n< / annotation>< / semantics>< / com:Math> is the spindle speed, <com:Math><semantics>Asp<annotation encoding="application / x-tex">A_{sp}< / annotation>< / semantics>< / com:Math> and <com:Math><semantics>Bsp<annotation encoding="application / x-tex">B_{sp}< / annotation>< / semantics>< / com:Math> are the coefficients of the formula, and <com:Math><semantics>Tspindle<annotation encoding="application / x-tex">T_{spindle}< / annotation>< / semantics>< / com:Math> is a time for maintaining the constant-speed rotation motion of the spindle; the energy consumption of the machine tool spindle in accelerating motion is: [Image disponible dans le document PDF, Image available in the PDF document] wherein <com:Math><semantics>ESRA<annotation encoding="application / x-tex">E_{SRA}< / annotation>< / semantics>< / com:Math> is the energy consumption of the machine tool spindle in accelerating motion, <com:Math><semantics>Ts<annotation encoding="application / x-tex">T_s< / annotation>< / semantics>< / com:Math> is an equivalent acceleration torque of a spindle system to the spindle, <com:Math><semantics>α<annotation encoding="application / x-tex">\alpha< / annotation>< / semantics>< / com:Math> is a spindle angular acceleration, <com:Math><semantics>n1<annotation encoding="application / x-tex">n_1< / annotation>< / semantics>< / com:Math> is the initial spindle speed, <com:Math><semantics>n2<annotation encoding="application / x-tex">n_2< / annotation>< / semantics>< / com:Math> is the target spindle speed, <com:Math><semantics>TSRA1<annotation encoding="application / x-tex">T_{SRA1}< / annotation>< / semantics>< / com:Math> is a time from the start of spindle acceleration to a power peak period, and <com:Math><semantics>TSR42<annotation encoding="application / x-tex">T_{SR42}< / annotation>< / semantics>< / com:Math> is a time of transition from the power peak to a stable power period. Further, acquiring the energy consumption of the machine tool in the no-load motion process and the energy consumption when the spindle deceleration strategy is implemented comprises: acquiring the time of a spindle rotation acceleration process; acquiring the energy consumption of the machine tool in the no-load motion process based on the initial spindle speed, the target spindle speed, the energy consumption of the CNC machine tool in each motion state and the time of the spindle rotation acceleration process; acquiring the energy consumption when the spindle deceleration strategy is implemented based on the spindle speed after deceleration, the target spindle speed, the energy consumption of the CNC machine tool in each motion state and the time of the spindle rotation acceleration process. Further, the time of the spindle rotation acceleration process is obtained based on the time from the start of spindle acceleration to the power peak period and the time of transition from the power peak to the stable power period. Further, the energy consumption of the machine tool in the no-load motion process is: [Image disponible dans le document PDF, Image available in the PDF document] wherein <com:Math><semantics>Enoload<annotation encoding="application / x-tex">E_{no\ load}< / annotation>< / semantics>< / com:Math> is the energy consumption of the machine tool in the no-load motion process and <com:Math><semantics>TO<annotation encoding="application / x-tex">T_O< / annotation>< / semantics>< / com:Math> is the no-load interval time. Further, the energy consumption when the spindle deceleration strategy is implemented is: [Image disponible dans le document PDF, Image available in the PDF document] wherein <com:Math><semantics>Edeceleration<annotation encoding="application / x-tex">E_{deceleration}< / annotation>< / semantics>< / com:Math> is the energy consumption when the spindle deceleration strategy is implemented, and <com:Math><semantics>ni<annotation encoding="application / x-tex">n_i< / annotation>< / semantics>< / com:Math> is the spindle speed after deceleration. Further, the energy saving prerequisites are: the energy consumption when the spindle deceleration strategy is implemented is less than the energy consumption of the machine tool in the no-load motion process, and the time of the spindle rotation acceleration process is less than the no-load interval time. Further, the energy saving critical time of spindle deceleration is: a time required when an energy demand of the machine tool during operation in an original processing operating state is equal to an energy demand when the spindle is decelerated and then accelerated to the target speed. Further, the energy saving for the spindle deceleration in the no-load interval is: [Image disponible dans le document PDF, Image available in the PDF document] wherein <com:Math><semantics>Esaving<annotation encoding="application / x-tex">E_{saving}< / annotation>< / semantics>< / com:Math> is the energy saving, <com:Math><semantics>Enoload<annotation encoding="application / x-tex">E_{no\ load}< / annotation>< / semantics>< / com:Math> is the energy consumption of the machine tool in the no-load motion process and <com:Math><semantics>Edeceleration<annotation encoding="application / x-tex">E_{deceleration}< / annotation>< / semantics>< / com:Math> is the energy consumption when the spindle deceleration strategy is implemented. In accordance with an aspect of at least one embodiment, there is provided an energy saving method of spindle deceleration in a no-load process between adjacent cutting activities of a CNC machine tool, comprising: collecting spindle state speed and no-load interval time between adjacent cutting activities; acquiring the energy consumption of the CNC machine tool in each motion state; acquiring energy consumption of the machine tool in a no-load motion process and energy consumption when a spindle deceleration strategy is implemented based on the spindle state speed and the energy consumption of the CNC machine tool in each motion state; presetting energy saving prerequisites; acquiring the energy saving critical time of spindle deceleration after the energy consumption of the machine tool in the no-load motion process, the energy consumption when the spindle deceleration strategy is implemented and the no-load interval time satisfy the energy saving prerequisites; and conducting spindle deceleration in a no-load interval when the no-load interval time is greater than the energy saving critical time of spindle deceleration; wherein the energy consumption of the CNC machine tool in each motion state comprises: the energy consumption of a machine tool foundation module, the energy consumption of a machine tool spindle in constant-speed rotation motion and the energy consumption of the machine tool spindle in accelerating motion; the energy consumption of the machine tool foundation module is: [Image disponible dans le document PDF, Image available in the PDF document] wherein <com:Math><semantics>Estandby<annotation encoding="application / x-tex">E_{standby}< / annotation>< / semantics>< / com:Math> is the energy consumption of the machine tool foundation module, <com:Math><semantics>Pstandby<annotation encoding="application / x-tex">P_{standby}< / annotation>< / semantics>< / com:Math> is a power when the operation of the machine tool foundation module is maintained, <com:Math><semantics>Pstandbyi<annotation encoding="application / x-tex">P_{standby i}< / annotation>< / semantics>< / com:Math> is a power value of the machine tool foundation module collected at an ith time by an experimental device, N is the number of data collection, and <com:Math><semantics>Tstandby<annotation encoding="application / x-tex">T_{standby}< / annotation>< / semantics>< / com:Math> is a time for maintaining the operation of the machine tool foundation module; the energy consumption of the machine tool spindle in constant-speed rotation motion is: [Image disponible dans le document PDF, Image available in the PDF document] wherein <com:Math><semantics>Espindle<annotation encoding="application / x-tex">E_{spindle}< / annotation>< / semantics>< / com:Math> is the energy consumption of the machine tool spindle in constant-speed rotation motion, <com:Math><semantics>Pspindle<annotation encoding="application / x-tex">P_{spindle}< / annotation>< / semantics>< / com:Math> is the power of the machine tool spindle in constant-speed rotation motion, n is the spindle speed, <com:Math><semantics>Asp<annotation encoding="application / x-tex">A_{sp}< / annotation>< / semantics>< / com:Math> and <com:Math><semantics>Bsp<annotation encoding="application / x-tex">B_{sp}< / annotation>< / semantics>< / com:Math> are the coefficients of the formula, and <com:Math><semantics>Tspindle<annotation encoding="application / x-tex">T_{spindle}< / annotation>< / semantics>< / com:Math> is a time for maintaining the constant-speed rotation motion of the spindle; the energy consumption of the machine tool spindle in accelerating motion is: [Image disponible dans le document PDF, Image available in the PDF document] wherein <com:Math><semantics>ESRA<annotation encoding="application / x-tex">E_{SRA}< / annotation>< / semantics>< / com:Math> is the energy consumption of the machine tool spindle in accelerating motion, <com:Math><semantics>Ts<annotation encoding="application / x-tex">T_s< / annotation>< / semantics>< / com:Math> is an equivalent acceleration torque of a spindle system to the spindle, <com:Math><semantics>α<annotation encoding="application / x-tex">\alpha< / annotation>< / semantics>< / com:Math> is a spindle angular acceleration, <com:Math><semantics>n1<annotation encoding="application / x-tex">n_1< / annotation>< / semantics>< / com:Math> is the initial spindle speed, <com:Math><semantics>n2<annotation encoding="application / x-tex">n_2< / annotation>< / semantics>< / com:Math> is the target spindle speed, <com:Math><semantics>TSRA1<annotation encoding="application / x-tex">T_{SRA1}< / annotation>< / semantics>< / com:Math> is a time from the start of spindle acceleration to a power peak period, and <com:Math><semantics>TSRA2<annotation encoding="application / x-tex">T_{SRA2}< / annotation>< / semantics>< / com:Math> is a time of transition from the power peak to a stable power period; wherein the energy consumption when the spindle deceleration strategy is implemented is: [Image disponible dans le document PDF, Image available in the PDF document] wherein <com:Math><semantics>Edeceleration<annotation encoding="application / x-tex">E_{deceleration}< / annotation>< / semantics>< / com:Math> is the energy consumption when the spindle deceleration strategy is implemented, and <com:Math><semantics>ni<annotation encoding="application / x-tex">n_i< / annotation>< / semantics>< / com:Math> is the spindle speed after deceleration; wherein the energy saving prerequisites are: the energy consumption when the spindle deceleration strategy is implemented is less than the energy consumption of the machine tool in the no-load motion process, and the time of the spindle rotation acceleration process is less than the no-load interval time; wherein the energy saving critical time of spindle deceleration is: a time required when an energy demand of the machine tool during operation in an original processing operating state is equal to an energy demand when the spindle is decelerated and then accelerated to the target speed; and the energy saving critical time of spindle deceleration is: [Image disponible dans le document PDF, Image available in the PDF document] wherein, <com:Math><semantics>Tsaving<annotation encoding="application / x-tex">T_{saving}< / annotation>< / semantics>< / com:Math> is the energy saving critical time of spindle deceleration, <com:Math><semantics>ESRA<annotation encoding="application / x-tex">E_{SRA}< / annotation>< / semantics>< / com:Math> is the energy consumption of the machine tool spindle in accelerating motion, <com:Math><semantics>n1<annotation encoding="application / x-tex">n_1< / annotation>< / semantics>< / com:Math> is the initial spindle speed, <com:Math><semantics>n2<annotation encoding="application / x-tex">n_2< / annotation>< / semantics>< / com:Math> is the target spindle speed, <com:Math><semantics>Pspindle<annotation encoding="application / x-tex">P_{spindle}< / annotation>< / semantics>< / com:Math> is the power of the machine tool spindle in constant-speed rotation motion, <com:Math><semantics>ni<annotation encoding="application / x-tex">n_i< / annotation>< / semantics>< / com:Math> is the spindle speed after deceleration and <com:Math><semantics>TSRA<annotation encoding="application / x-tex">T_{SRA}< / annotation>< / semantics>< / com:Math> is the time of the spindle rotation acceleration process, in unit of s. Compared with the prior art, the present invention has the following advantages and technical effects: The present invention focuses on the problem of energy waste in the no-load process of the CNC machine tool. The spindle speed during no-load operation of the machine tool is decreased to reduce the energy consumption in the no-load process of the machine tool, so as to improve the energy utilization rate of the machine tool, and thus avoid the loss of the machine tool main transmission system and the motor caused by the traditional energy saving method of spindle shutdown. The method of the present invention has the characteristics of accurate energy saving prediction calculation, and convenient popularization and application, and can help engineers and managers to better manage the energy saving of the machine tool equipment, so as to provide theoretical guidance for the energy saving and emission reduction and benefit improvement of enterprises. Description of Drawings Drawings forming a part of the present application are used for providing further understanding of the present application. Exemplary embodiments of the present application and the description are used for explaining the present application, but do not constitute an improper limitation to the present application. In the figures: Fig. 1 is a flow chart of an energy saving method in an embodiment of the present invention; Fig. 2 is a schematic diagram of spindle deceleration in an embodiment of the present invention; Fig. 3 is a schematic diagram of an energy saving effect in an embodiment of the present invention. Detailed Description It should be explained that if there is no conflict, the embodiments in the present application and the features in the embodiments can be mutually combined. The present application will be described in detail below by reference to the drawings and in conjunction with the embodiments. It should be noted that the steps shown in the flow chart of the figure can be executed in a computer system such as a set of computer-executable instructions, and although the logical sequence is shown in the flow chart, in some cases, the steps shown or described can be executed in a sequence different from the sequence here. Embodiments The present embodiment provides an energy saving method of spindle deceleration in a no-load process between adjacent cutting activities of a CNC machine tool, comprising: collecting spindle state speed and no-load interval time between adjacent cutting activities; acquiring the energy consumption of the CNC machine tool in each motion state; acquiring energy consumption of the machine tool in a no-load motion process and energy consumption when a spindle deceleration strategy is implemented based on the spindle state speed and the energy consumption of the CNC machine tool in each motion state; presetting energy saving prerequisites; acquiring the energy saving critical time of spindle deceleration after the energy consumption of the machine tool in the no-load motion process, the energy consumption when the spindle deceleration strategy is implemented and the no-load interval time satisfy the energy saving prerequisites; and conducting spindle deceleration in a no-load interval when the no-load interval time is greater than the energy saving critical time of spindle deceleration. Further, the spindle state speed comprises: initial spindle speed, target spindle speed and spindle speed after deceleration. Further, the energy consumption of the CNC machine tool in each motion state comprises: the energy consumption of a machine tool foundation module, the energy consumption of a machine tool spindle in constant-speed rotation motion and the energy consumption of the machine tool spindle in accelerating motion; the energy consumption of the machine tool foundation module is: [Image disponible dans le document PDF, Image available in the PDF document] wherein <com:Math><semantics>Estandby<annotation encoding="application / x-tex">E_{standby}< / annotation>< / semantics>< / com:Math> is the energy consumption of the machine tool foundation module, <com:Math><semantics>Pstandby<annotation encoding="application / x-tex">P_{standby}< / annotation>< / semantics>< / com:Math> is a power when the operation of the machine tool foundation module is maintained, <com:Math><semantics>Pstandbyi<annotation encoding="application / x-tex">P_{standby i}< / annotation>< / semantics>< / com:Math> is a power value of the machine tool foundation module collected at an ith time by an experimental device, N is the number of data collection, and <com:Math><semantics>Tstandby<annotation encoding="application / x-tex">T_{standby}< / annotation>< / semantics>< / com:Math> is a time for maintaining the operation of the machine tool foundation module; the energy consumption of the machine tool spindle in constant-speed rotation motion is: [Image disponible dans le document PDF, Image available in the PDF document] wherein <com:Math><semantics>Espindle<annotation encoding="application / x-tex">E_{spindle}< / annotation>< / semantics>< / com:Math> is the energy consumption of the machine tool spindle in constant-speed rotation motion, <com:Math><semantics>Pspindle<annotation encoding="application / x-tex">P_{spindle}< / annotation>< / semantics>< / com:Math> is the power of the machine tool spindle in constant-speed rotation motion, n is the spindle speed, <com:Math><semantics>Asp<annotation encoding="application / x-tex">A_{sp}< / annotation>< / semantics>< / com:Math> and <com:Math><semantics>Bsp<annotation encoding="application / x-tex">B_{sp}< / annotation>< / semantics>< / com:Math> are the coefficients of the formula, and <com:Math><semantics>Tspindle<annotation encoding="application / x-tex">T_{spindle}< / annotation>< / semantics>< / com:Math> is a time for maintaining the constant-speed rotation motion of the spindle; the energy consumption of the machine tool spindle in accelerating motion is: [Image disponible dans le document PDF, Image available in the PDF document] wherein <com:Math><semantics>ESRA<annotation encoding="application / x-tex">E_{SRA}< / annotation>< / semantics>< / com:Math> is the energy consumption of the machine tool spindle in accelerating motion, <com:Math><semantics>Ts<annotation encoding="application / x-tex">T_s< / annotation>< / semantics>< / com:Math> is an equivalent acceleration torque of a spindle system to the spindle, <com:Math><semantics>α<annotation encoding="application / x-tex">\alpha< / annotation>< / semantics>< / com:Math> is a spindle angular acceleration, <com:Math><semantics>n1<annotation encoding="application / x-tex">n_1< / annotation>< / semantics>< / com:Math> is the initial spindle speed, <com:Math><semantics>n2<annotation encoding="application / x-tex">n_2< / annotation>< / semantics>< / com:Math> is the target spindle speed, <com:Math><semantics>TSRA1<annotation encoding="application / x-tex">T_{SRA1}< / annotation>< / semantics>< / com:Math> is a time from the start of spindle acceleration to a power peak period, and <com:Math><semantics>TSR42<annotation encoding="application / x-tex">T_{SR42}< / annotation>< / semantics>< / com:Math> is a time of transition from the power peak to a stable power period. Further, acquiring the energy consumption of the machine tool in the no-load motion process and the energy consumption when the spindle deceleration strategy is implemented comprises: acquiring the time of a spindle rotation acceleration process; acquiring the energy consumption of the machine tool in the no-load motion process based on the initial spindle speed, the target spindle speed, the energy consumption of the CNC machine tool in each motion state and the time of the spindle rotation acceleration process; acquiring the energy consumption when the spindle deceleration strategy is implemented based on the spindle speed after deceleration, the target spindle speed, the energy consumption of the CNC machine tool in each motion state and the time of the spindle rotation acceleration process. Further, the time of the spindle rotation acceleration process is obtained based on the time from the start of spindle acceleration to the power peak period and the time of transition from the power peak to the stable power period. Further, the energy saving prerequisites are: the energy consumption when the spindle deceleration strategy is implemented is less than the energy consumption of the machine tool in the no-load motion process, and the time of the spindle rotation acceleration process is less than the no-load interval time. Further, the energy saving critical time of spindle deceleration is: a time required when an energy demand of the machine tool during operation in an original processing operating state is equal to an energy demand when the spindle is decelerated and then accelerated to the target speed. Further, the energy saving for the spindle deceleration in the no-load interval is: [Image disponible dans le document PDF, Image available in the PDF document] wherein <com:Math><semantics>Esaving<annotation encoding="application / x-tex">E_{saving}< / annotation>< / semantics>< / com:Math> is the energy saving, <com:Math><semantics>Enoload<annotation encoding="application / x-tex">E_{no\ load}< / annotation>< / semantics>< / com:Math> is the energy consumption of the machine tool in the no-load motion process and <com:Math><semantics>Edeceleration<annotation encoding="application / x-tex">E_{deceleration}< / annotation>< / semantics>< / com:Math> is the energy consumption when the spindle deceleration strategy is implemented. The present invention proposes an energy saving method of spindle deceleration in a no-load process between adjacent cutting activities of a CNC machine tool, comprising: collecting spindle state speed and no-load interval time between adjacent cutting activities; acquiring the energy consumption of the CNC machine tool in each motion state; acquiring energy consumption of the machine tool in a no-load motion process and energy consumption when a spindle deceleration strategy is implemented based on the spindle state speed and the energy consumption of the CNC machine tool in each motion state; presetting energy saving prerequisites; acquiring the energy saving critical time of spindle deceleration after the energy consumption of the machine tool in the no-load motion process, the energy consumption when the spindle deceleration strategy is implemented and the no-load interval time satisfy the energy saving prerequisites; and conducting spindle deceleration in a no-load interval when the no-load interval time is greater than the energy saving critical time of spindle deceleration. The flow chart is shown in Fig. 1. Taking a CNC lathe with model CK6153i as an example, the above energy saving method of spindle deceleration is explained in detail, and the specific process is as follows: 1. Acquisition of energy consumption of a CNC machine tool in each motion state Formula of the energy consumption of a machine tool foundation module (a fan, illumination, a display and a control panel) is: After the CNC machine tool is started, a power value for maintaining the operation of the CNC machine tool foundation module is basically stable. Therefore, the average value of N measured power values can be used for calculating the basic energy demand of the CNC machine tool. According to the experimental data (measured values of the operating power of the machine tool foundation module in Table 1) collected by a power collection experimental device, the energy consumption of the foundation module of the CK6153i CNC lathe is further obtained: [Image disponible dans le document PDF, Image available in the PDF document] (1) In the formula, <com:Math><semantics>Pstandby<annotation encoding="application / x-tex">P_{standby}< / annotation>< / semantics>< / com:Math> is a power for maintaining the operation of the machine tool foundation module, in unit of W; <com:Math><semantics>Pstandbyi<annotation encoding="application / x-tex">P_{standby i}< / annotation>< / semantics>< / com:Math> is a power value of the machine tool foundation module collected at an ith time by the experimental device, in unit of W; N is the number of data collection; and <com:Math><semantics>Tstandby<annotation encoding="application / x-tex">T_{standby}< / annotation>< / semantics>< / com:Math> is a time for maintaining the operation of the machine tool foundation module, in unit of s, and obtained through a numerical control procedure. Table 1 [Image disponible dans le document PDF, Image available in the PDF document] (2) Energy consumption of the machine tool spindle in constant-speed rotation motion The power for maintaining the operation of the CNC machine tool foundation module is subtracted from the collected total spindle rotation power of the CK6153i CNC lathe at different speeds to obtain the spindle rotation power. According to the experimental data (measured values of spindle rotation power at different speeds in Table 2), <com:Math><semantics>Asp<annotation encoding="application / x-tex">A_{sp}< / annotation>< / semantics>< / com:Math>=41.12 and <com:Math><semantics>Bsp<annotation encoding="application / x-tex">B_{sp}< / annotation>< / semantics>< / com:Math>=1.09 are obtained from the fitting results, so the energy consumption of the spindle in constant-speed rotation motion is further obtained. [Image disponible dans le document PDF, Image available in the PDF document] (2) In the formula, <com:Math><semantics>Pspindle<annotation encoding="application / x-tex">P_{spindle}< / annotation>< / semantics>< / com:Math> is the power of the machine tool spindle in constant-speed rotation motion, in unit of W; n is the spindle speed, in unit of r / min; <com:Math><semantics>Asp<annotation encoding="application / x-tex">A_{sp}< / annotation>< / semantics>< / com:Math> and <com:Math><semantics>Bsp<annotation encoding="application / x-tex">B_{sp}< / annotation>< / semantics>< / com:Math> are the coefficients of the formula, and are obtained by linear fitting of experimental data; <com:Math><semantics>Tspindle<annotation encoding="application / x-tex">T_{spindle}< / annotation>< / semantics>< / com:Math> is a time for maintaining the constant-speed rotation motion of the spindle, in unit of s, and obtained through a numerical control procedure. Table 2 [Image disponible dans le document PDF, Image available in the PDF document] (3) Formula of energy consumption of the machine tool spindle in accelerating motion The CK6153i CNC lathe has four gears, which are AH, BH, AL and BL from high speed to low speed, corresponding to four transmission chains, wherein the AH gear has the widest processing range and is commonly used. The present embodiment takes the AH gear as an example to carry out a spindle acceleration experiment. The coefficients <com:Math><semantics>Ts=28.42Ngm<annotation encoding="application / x-tex">T_s = 28.42 \text{Ngm}< / annotation>< / semantics>< / com:Math> and <com:Math><semantics>α=39.78rad / s2<annotation encoding="application / x-tex">\alpha = 39.78 \text{rad / s}^2< / annotation>< / semantics>< / com:Math> of an AH gear transmission chain are obtained according to a spindle starting experiment and in combination with a statistical analysis method. Therefore, the time of a spindle rotation acceleration process can be represented as: [Image disponible dans le document PDF, Image available in the PDF document] (3) In the formula, <com:Math><semantics>TSRA<annotation encoding="application / x-tex">T_{SRA}< / annotation>< / semantics>< / com:Math> is the time of the spindle rotation acceleration process, in unit of s; <com:Math><semantics>TSRA1<annotation encoding="application / x-tex">T_{SRA1}< / annotation>< / semantics>< / com:Math> is a time from the start of spindle acceleration to a power peak period, in unit of s; <com:Math><semantics>TSRA2<annotation encoding="application / x-tex">T_{SRA2}< / annotation>< / semantics>< / com:Math> is a time of transition from the power peak to a stable power period, in unit of s. Similarly, the formula of the energy consumption of the machine tool spindle in accelerating motion is further obtained: [Image disponible dans le document PDF, Image available in the PDF document] (4) According to formula (1), formula (2), formula (3), formula (4), the initial spindle speed <com:Math><semantics>n1<annotation encoding="application / x-tex">n_1< / annotation>< / semantics>< / com:Math> of the CNC machine tool and the target spindle speed <com:Math><semantics>n2<annotation encoding="application / x-tex">n_2< / annotation>< / semantics>< / com:Math>, the energy consumption of the machine tool in the no-load motion process at any speed can be calculated. In the present embodiment, with an example that the initial spindle speed is less than the target speed, the expression of the energy consumption <com:Math><semantics>Enoload<annotation encoding="application / x-tex">E_{no\ load}< / annotation>< / semantics>< / com:Math> in the no-load process is: [Image disponible dans le document PDF, Image available in the PDF document] (5) Similarly, according to formula (1), formula (2), formula (3), formula (4), the speed <com:Math><semantics>ni<annotation encoding="application / x-tex">n_i< / annotation>< / semantics>< / com:Math> of the CNC machine tool after spindle deceleration and the target spindle speed <com:Math><semantics>n2<annotation encoding="application / x-tex">n_2< / annotation>< / semantics>< / com:Math>, the energy consumption <com:Math><semantics>Edeceleration<annotation encoding="application / x-tex">E_{deceleration}< / annotation>< / semantics>< / com:Math> when the spindle deceleration strategy is implemented can be calculated, with the expression as follows: [Image disponible dans le document PDF, Image available in the PDF document] (6) The energy saving critical time <com:Math><semantics>Tsaving<annotation encoding="application / x-tex">T_{saving}< / annotation>< / semantics>< / com:Math> of implementing the spindle deceleration strategy in the no-load process between adjacent cutting activities of the CNC machine tool is further calculated according to formula (5) and formula (6), with the expression as follows: [Image disponible dans le document PDF, Image available in the PDF document] (7) Similarly, the energy saving effect <com:Math><semantics>Esaving<annotation encoding="application / x-tex">E_{saving}< / annotation>< / semantics>< / com:Math> of implementing the spindle deceleration strategy in the no-load process between adjacent cutting activities of the CNC machine tool is further calculated according to formula (5) and formula (6), with the expression as follows: [Image disponible dans le document PDF, Image available in the PDF document] (8) In addition, for a given machine tool model, the above formulas are constant and available for a long time. 2. Energy saving decision of machine tool spindle deceleration When a part is processed by the CK6153i CNC lathe, it is necessary to turn the end surface at a speed of 500 r / min and turn the outer circle at a speed of 1000 r / min according to the processing requirements. There are no-load motion stages of retracting and feeding between adjacent cutting activities, with a total duration of 10 seconds, i.e., <com:Math><semantics>T0=10<annotation encoding="application / x-tex">T_0 = 10< / annotation>< / semantics>< / com:Math>s. Specific decision steps are as follows: (1) <com:Math><semantics>n1=500r / min<annotation encoding="application / x-tex">n_1 = 500 \text{r / min}< / annotation>< / semantics>< / com:Math> and <com:Math><semantics>n2=1000r / min<annotation encoding="application / x-tex">n_2 = 1000 \text{r / min}< / annotation>< / semantics>< / com:Math> are substituted into formula (5) to calculate the energy consumption <com:Math><semantics>Enoload<annotation encoding="application / x-tex">E_{no\ load}< / annotation>< / semantics>< / com:Math> of the machine tool in the no-load process between the adjacent cutting activities as 12185.79J. (2) It is assumed that the spindle speed after deceleration is <com:Math><semantics>ni=200r / min<annotation encoding="application / x-tex">n_i = 200 \text{r / min}< / annotation>< / semantics>< / com:Math>, which is substituted into formula (6) to calculate the energy consumption <com:Math><semantics>Edeceleration<annotation encoding="application / x-tex">E_{deceleration}< / annotation>< / semantics>< / com:Math> when the spindle deceleration strategy is implemented between the adjacent cutting activities as 10359.14J. (3) The spindle speed <com:Math><semantics>ni=200r / min<annotation encoding="application / x-tex">n_i = 200 \text{r / min}< / annotation>< / semantics>< / com:Math> after deceleration and the target speed <com:Math><semantics>n2=1000r / min<annotation encoding="application / x-tex">n_2 = 1000 \text{r / min}< / annotation>< / semantics>< / com:Math> are substituted into formula (3) to calculate the time demand <com:Math><semantics>TSRA<annotation encoding="application / x-tex">T_{SRA}< / annotation>< / semantics>< / com:Math> when the spindle is decelerated and then accelerated to the target speed as 1.50s. (4) If <com:Math><semantics>Eno_load>Edeceleration<annotation encoding="application / x-tex">E_{no\_load} > E_{deceleration}< / annotation>< / semantics>< / com:Math> and <com:Math><semantics>TO>TSRA<annotation encoding="application / x-tex">T_O > T_{SRA}< / annotation>< / semantics>< / com:Math>, it indicates that in this case, the prerequisite that the implementation of the spindle deceleration strategy of the machine tool can achieve the energy saving effect is satisfied. In the present embodiment, <com:Math><semantics>Enoload=12185.79J>Edeceleration=10359.14J<annotation encoding="application / x-tex">E_{no\ load} = 12185.79 J > E_{deceleration} = 10359.14 J< / annotation>< / semantics>< / com:Math> and <com:Math><semantics>TO=10<annotation encoding="application / x-tex">T_O = 10< / annotation>< / semantics>< / com:Math>s > <com:Math><semantics>TSRA=1.50<annotation encoding="application / x-tex">T_{SRA} = 1.50< / annotation>< / semantics>< / com:Math>s, i.e., the prerequisite is satisfied. (5) <com:Math><semantics>n1=500r / min<annotation encoding="application / x-tex">n_1 = 500 \text{r / min}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>n2=1000r / min<annotation encoding="application / x-tex">n_2 = 1000 \text{r / min}< / annotation>< / semantics>< / com:Math> and <com:Math><semantics>ni=200r / min<annotation encoding="application / x-tex">n_i = 200 \text{r / min}< / annotation>< / semantics>< / com:Math> are substituted into formula (7) to calculate the energy saving critical time <com:Math><semantics>Tsaving<annotation encoding="application / x-tex">T_{saving}< / annotation>< / semantics>< / com:Math> when the spindle deceleration strategy is implemented between the adjacent cutting activities as 4.41s. It indicates that if the no-load interval time between two adjacent cutting activities is greater than 4.41s, the spindle deceleration strategy can be implemented in the no-load interval to achieve the purpose of energy saving, as shown in Fig. 2, wherein in the present embodiment, <com:Math><semantics>T0=10s<annotation encoding="application / x-tex">T_0 = 10s< / annotation>< / semantics>< / com:Math>. 6 [Image disponible dans le document PDF, Image available in the PDF document] are substituted into formula (8) to calculate the energy saving effect <com:Math><semantics>Esaving<annotation encoding="application / x-tex">E_{saving}< / annotation>< / semantics>< / com:Math> when the spindle deceleration strategy is implemented in the no-load process between the adjacent cutting activities as 1826.65J, as shown in Fig. 3. The above only describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any change or replacement contemplated easily by those skilled in the art familiar with the technical field within the technical scope disclosed by the present application shall be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be determined by the protection scope of the claims.

Claims

1. An energy saving method of spindle deceleration in a no-load process between adjacent cutting activities of a CNC machine tool, comprising: collecting spindle state speed and no-load interval time between adjacent cutting activities; acquiring the energy consumption of the CNC machine tool in each motion state; acquiring energy consumption of the machine tool in a no-load motion process and energy consumption when a spindle deceleration strategy is implemented based on the spindle state speed and the energy consumption of the CNC machine tool in each motion state; presetting energy saving prerequisites; acquiring the energy saving critical time of spindle deceleration after the energy consumption of the machine tool in the no-load motion process, the energy consumption when the spindle deceleration strategy is implemented and the no-load interval time satisfy the energy saving prerequisites; and conducting spindle deceleration in a no-load interval when the no-load interval time is greater than the energy saving critical time of spindle deceleration; wherein the energy consumption of the CNC machine tool in each motion state comprises: the energy consumption of a machine tool foundation module, the energy consumption of a machine tool spindle in constant-speed rotation motion and the energy consumption of the machine tool spindle in accelerating motion; the energy consumption of the machine tool foundation module is: [Image disponible dans le document PDF, Image available in the PDF document] wherein E s t a n d b y E_{standby} is the energy consumption of the machine tool foundation module, P s t a n d b y P_{standby} is a power when the operation of the machine tool foundation module is maintained, P s t a n d b y i P_{standby i} is a power value of the machine tool foundation module collected at an ith time by an experimental device, N is the number of data collection, and T s t a n d b y T_{standby} is a time for maintaining the operation of the machine tool foundation module; the energy consumption of the machine tool spindle in constant-speed rotation motion is: [Image disponible dans le document PDF, Image available in the PDF document] wherein E s p i n d l e E_{spindle} is the energy consumption of the machine tool spindle in constant-speed rotation motion, P s p i n d l e P_{spindle} is the power of the machine tool spindle in constant-speed rotation motion, n n is the spindle speed, A s p A_{sp} and B s p B_{sp} are the coefficients of the formula, and T s p i n d l e T_{spindle} is a time for maintaining the constant-speed rotation motion of the spindle; the energy consumption of the machine tool spindle in accelerating motion is: [Image disponible dans le document PDF, Image available in the PDF document] wherein E S R A E_{SRA} is the energy consumption of the machine tool spindle in accelerating motion, T s T_s is an equivalent acceleration torque of a spindle system to the spindle, α \alpha is a spindle angular acceleration, n 1 n_1 is the initial spindle speed, n 2 n_2 is the target spindle speed, T S R A 1 T_{SRA1} is a time from the start of spindle acceleration to a power peak period, and T S R A 2 T_{SRA2} is a time of transition from the power peak to a stable power period; wherein the energy consumption when the spindle deceleration strategy is implemented is: [Image disponible dans le document PDF, Image available in the PDF document] wherein E d e c e l e r a t i o n E_{deceleration} is the energy consumption when the spindle deceleration strategy is implemented, and n i n_i is the spindle speed after deceleration; wherein the energy saving prerequisites are: the energy consumption when the spindle deceleration strategy is implemented is less than the energy consumption of the machine tool in the no-load motion process, and the time of the spindle rotation acceleration process is less than the no-load interval time; wherein the energy saving critical time of spindle deceleration is: a time required when an energy demand of the machine tool during operation in an original processing operating state is equal to an energy demand when the spindle is decelerated and then accelerated to the target speed; and the energy saving critical time of spindle deceleration is: [Image disponible dans le document PDF, Image available in the PDF document] wherein, T s a v i n g T_{saving} is the energy saving critical time of spindle deceleration, E S R A E_{SRA} is the energy consumption of the machine tool spindle in accelerating motion, n 1 n_1 is the initial spindle speed, n 2 n_2 is the target spindle speed, P s p i n d l e P_{spindle} is the power of the machine tool spindle in constant-speed rotation motion, n i n_i is the spindle speed after deceleration and T S R A T_{SRA} is the time of the spindle rotation acceleration process, in unit of s.

2. The energy saving method of spindle deceleration in the no-load process between adjacent cutting activities of the CNC machine tool according to claim 1, wherein the spindle state speed comprises: initial spindle speed, target spindle speed and spindle speed after deceleration.

3. The energy saving method of spindle deceleration in the no-load process between adjacent cutting activities of the CNC machine tool according to claim 1, wherein acquiring the energy consumption of the machine tool in the no-load motion process and the energy consumption when the spindle deceleration strategy is implemented comprises: acquiring the time of a spindle rotation acceleration process; acquiring the energy consumption of the machine tool in the no-load motion process based on the initial spindle speed, the target spindle speed, the energy consumption of the CNC machine tool in each motion state and the time of the spindle rotation acceleration process; acquiring the energy consumption when the spindle deceleration strategy is implemented based on the spindle speed after deceleration, the target spindle speed, the energy consumption of the CNC machine tool in each motion state and the time of the spindle rotation acceleration process.

4. The energy saving method of spindle deceleration in the no-load process between adjacent cutting activities of the CNC machine tool according to claim 3, wherein the time of the spindle rotation acceleration process is obtained based on the time from the start of spindle acceleration to the power peak period and the time of transition from the power peak to the stable power period.

5. The energy saving method of spindle deceleration in the no-load process between adjacent cutting activities of the CNC machine tool according to claim 3, wherein the energy consumption of the machine tool in the no-load motion process is: [Image disponible dans le document PDF, Image available in the PDF document] wherein E n o l o a d E_{no\ load} is the energy consumption of the machine tool in the no-load motion process and T O T_O is the no-load interval time.

6. The energy saving method of spindle deceleration in the no-load process between adjacent cutting activities of the CNC machine tool according to claim 1, wherein the energy saving for the spindle deceleration in the no-load interval is: [Image disponible dans le document PDF, Image available in the PDF document] wherein E s a v i n g E_{saving} is the energy saving, E n o _ l o a d E_{no\_load} is the energy consumption of the machine tool in the no-load motion process and E d e c e l e r a t i o n E_{deceleration} is the energy consumption when the spindle deceleration strategy is implemented.