CN112051801B

CN112051801B - Redundancy strategy method for monitoring overload of main shaft without sensor

Info

Publication number: CN112051801B
Application number: CN202010784530.5A
Authority: CN
Inventors: 何江涛; 罗宗兰; 李丹丹; 赵然
Original assignee: Beijing Beiyi Machine Tool Co ltd
Current assignee: Beijing Beiyi Machine Tool Co ltd
Priority date: 2020-08-06
Filing date: 2020-08-06
Publication date: 2022-05-17
Anticipated expiration: 2040-08-06
Also published as: CN112051801A

Abstract

A redundancy strategy method for monitoring spindle overload without a sensor belongs to the technical field of monitoring of electromechanical matching of a numerical control machine. The method comprises the steps of utilizing self-defined permanent storage parameters and monitoring state data resources and sensorless structure identification, namely identifying the current configuration of a spindle and a spindle motor, calculating a current motor operation early warning value according to a power torque curve commonly used by the spindle, and avoiding spindle overload by adopting a redundancy function subprogram embedded with real-time monitoring. The invention has the advantages that: according to the strategy method and the PLC program built in the system, the redundancy function subprogram is embedded, under the condition that specific spindle configuration parameters, functional application parameters and specific modes are defined, the PLC subprogram can circularly monitor and calculate the current spindle load in real time, and can safely and reliably meet the functional requirements of different numerical control systems.

Description

Redundancy strategy method for monitoring overload of main shaft without sensor

Technical Field

The invention relates to a redundancy strategy method for monitoring spindle overload without a sensor, belonging to the technical field of monitoring of electromechanical matching of a numerical control machine.

Background

In the process of performing rough machining (rough machining or semi-finish machining) by using a numerical control machine tool, the phenomenon of tool jamming (spindle locked rotation) of a spindle tool often occurs, the tool is damaged or damaged if the tool is light, and a machine tool or personnel is damaged if the tool is heavy. Conventional machine tool monitoring is generally ineffective in avoiding this problem. The load monitoring of a general numerical control machine tool spindle is realized through a driver load function of a spindle motor, the load monitoring is limited according to 200% of motor overload, and a system executes shutdown alarm processing after the motor does not generate heat, so that the motor is protected, and the problems of safety hazard and economic loss caused by cutter damage and the like due to the 'tool smoldering' phenomenon are not solved. The existing numerical control system lacks electromechanical matching monitoring strategies corresponding to various factors such as a cutter, cutting parameters, a machine tool spindle structure and the like aiming at a numerical control machine tool.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a redundancy strategy method for monitoring spindle overload without a sensor.

A redundancy strategy method for monitoring main shaft overload without a sensor comprises the following steps; the method comprises the steps of utilizing self-defined permanent storage parameters and monitoring state data resources and sensorless structure identification, namely identifying the current configuration of a spindle and a spindle motor, calculating a current motor operation early warning value according to a power torque curve commonly used by the spindle, and avoiding spindle overload by adopting a redundancy function subprogram embedded with real-time monitoring.

The invention has the advantages that: according to the strategy method and the PLC program built in the system, the redundancy function subprogram is embedded, under the condition that specific spindle configuration parameters, functional application parameters and specific modes are defined, the PLC subprogram can circularly monitor and calculate the current spindle load in real time, and can safely and reliably meet the functional requirements of different numerical control systems.

Drawings

A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein the accompanying drawings are included to provide a further understanding of the invention and form a part of this specification, and wherein the illustrated embodiments of the invention and the description thereof are intended to illustrate and not limit the invention, as illustrated in the accompanying drawings, in which:

FIG. 1 is a flow chart of the present invention.

The invention is further illustrated with reference to the following figures and examples.

Detailed Description

It will be apparent that those skilled in the art can make many modifications and variations based on the spirit of the present invention.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element, component or section is referred to as being "connected" to another element, component or section, it can be directly connected to the other element or section or intervening elements or sections may also be present. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art.

Example 1: as shown in fig. 1, a redundancy strategy method for sensorless monitoring of spindle overload includes the following steps; and embedding a main shaft load redundancy monitoring subprogram in a PLC program built in the system.

The main shaft load redundancy monitoring subprogram comprises the following steps: data which can be obtained in the spindle structure parameters, the spindle motor parameters and the like are configured in a program self-defined parameter area; starting a program: starting a function effective bit and a main shaft rotation instruction and speed reaching activation function; and (3) stopping the program: the spindle stall command skips this function subroutine.

A main shaft load redundancy monitoring subprogram creating and circulating operation flow:

step 1, calculating the rotating speed of a motor according to the rotating speed of a main shaft at the current gear; judging whether the rotating speed of the motor reaches the rated rotating speed (a monitoring judgment node): when the current motor rated power is lower than the rated rotation speed branch, calculating the current motor rated power, comparing the current motor rated power with the current motor rated power, calculating the actual power according to the load rate, and judging the current motor rated power to be overloaded when the set overload and delay are met; judging actual power according to the rated power of the motor and the load rate, and judging the motor to be overloaded when the set overload and delay are high or equal to the rated rotating speed branch; the overload signal triggers feed hold and gives an alarm.

Step 2, if the main shaft rotating speed value with the specific structure limitation exists, the feeding holding is directly triggered and an alarm is given when the instruction is given;

and 3, if the rated power of the main shaft with the specific structure limit exists, directly replacing the rated power of the original motor with the corresponding parameter, and operating according to the flow starting. The situation that different numerical control systems are configured on the numerical control machine tool can be responded, the redundant monitoring strategy can be implemented according to the system resources without additionally adding a sensor, and satisfactory effects can be obtained.

Example 2: as shown in fig. 1, a redundancy strategy method for sensorless monitoring of spindle overload includes the following steps;

initial conditions of the procedure: defining and configuring special variables for machine tools with different structures according to different CNC system resources, such as rated power P11 of a spindle motor configured by the machine tool, variable G of a gear ratio of a multi-gear spindle structure and the like, wherein the data can be obtained through initial setting or system variables;

step 1, when the program function configuration condition is met, starting the strategy algorithm;

step 2, the program obtains the special variable value according to the current state,

step 3, judging a: whether the gear ratio G of the main shaft gear shifting mechanism is 1 or not;

and 4, judging that a is Y (true), and assigning a variable: the spindle speed (n23) is equal to the motor speed (n 12); judging a to be N (false), and assigning a variable: main shaft rotation speed (n23) is equal to motor rotation speed (n 12)/speed ratio G;

step 5, judging b: whether the actual rotating speed of the spindle motor is greater than the rated rotating speed of the spindle motor or not;

step 6, judging that b is Y, assigning a variable: the current rated power (P21) of the spindle motor is equal to the rated power (P11) of the spindle motor; judging b to be N, and assigning a variable: the current rated power (P21) of the spindle motor is motor rated power (P11) motor speed (n 12)/motor rated speed (n 11);

step 7, judging that: whether a program start condition is satisfied;

step 8, judging that c is Y, and starting a main shaft monitoring function (function activation); judging that c is N, skipping the main shaft monitoring function (function is invalid), and circularly running the program;

step 9, judging d: whether the spindle mechanism needs to be limited (set) in rotation speed;

step 9.1, judging d 1: whether the main shaft command rotation speed (n24) is less than the main shaft limit rotation speed (n 22);

step 10, judging d to be Y, and starting 9.1 branch judgment; judging d to be N, and starting 11 branches for judgment;

step 10.1, judging d1 to be Y, and starting 11 branch judgment; judging that d1 is N, and giving an alarm for the main shaft instruction speed limit;

step 11, judging e: whether the spindle mechanism requires power limitation;

step 12, judging that e is Y, and starting 13 branch judgment; judging that e is N, and skipping the power monitoring of the main shaft;

step 13, judging f: whether the main shaft mechanism requires power is quantitatively limited;

step 13.1, judging f 1: whether the main shaft limited power (P22) is smaller than P23 according to the main shaft current rated power (P23) which is the motor current rated power (P21) and the main shaft motor load (Q13);

step 14, judging that f is Y, and starting 13.1 branch judgment; judging f to be N, and starting 15 branches for judgment;

step 14.1, judging that f1 is Y, and alarming by limiting the quantitative power of the main shaft; judging f1 to be N, and starting a branch 15 judgment;

step 15, judging g: whether the spindle mechanism requires load limiting (setting);

step 16, judging g to be Y, and starting 15.1 branch judgment; judging that g is N, skipping the main shaft load monitoring function, and circularly running the program;

step 15.1, judging that g 1: whether the spindle defining load (Q) is less than the spindle motor load (Q13);

step 16.1, judging that g1 is Y, and circularly running the program; and judging that g1 is N, and giving an alarm for the limitation of the main shaft load.

As described above, although the embodiments of the present invention have been described in detail, it will be apparent to those skilled in the art that many modifications are possible without substantially departing from the spirit and scope of the present invention. Therefore, such modifications are also all included in the scope of protection of the present invention.

Claims

1. A redundancy strategy method for monitoring spindle overload without a sensor is characterized by comprising the following steps: utilizing self-defined permanent storage parameters and monitoring state data resources and sensorless structure identification, namely identifying the current configuration of a spindle and a spindle motor, calculating the running early warning value of the current motor according to a power torque curve commonly used by the spindle, adopting a redundancy function subprogram embedded in a numerical control system and monitored in real time, and creating, circulating running contents, starting/stopping program conditions and triggering alarm levels of the subprogram, thereby achieving the purpose of avoiding the overload of the spindle;

the subprogram creating and circulating operation process comprises the following steps:

step 1, calculating the rotating speed of a motor according to the rotating speed of a main shaft and a current gear; judging whether the rotating speed of the motor reaches the rated rotating speed: when the current motor rated power is lower than the rated rotation speed branch, calculating the current motor rated power, comparing the current motor rated power with the current motor rated power, calculating the actual power according to the load rate, and judging the current motor rated power to be overloaded when the set overload and delay are met; judging actual power according to the rated power of the motor and the load rate, and judging the motor to be overloaded when the set overload and delay are high or equal to the rated rotating speed branch; the overload signal triggers the feeding to keep and sends out an alarm;

step 3, if the rated power of the main shaft with the specific structure limitation exists, the rated power of the original motor can be directly replaced by corresponding parameters, and the operation is started according to the flow; the method can deal with the situation that the numerical control machine tool is configured with different numerical control systems, and can obtain satisfactory effect only according to system resources without additionally adding a sensor.

2. The redundancy strategy method for sensorless monitoring of spindle overload according to claim 1, wherein the redundancy function subroutine includes:

setting defined parameters, a spindle power algorithm and functional application conditions;

starting a program: after the self-defined function configuration, when the numerical control system receives a main shaft rotation instruction and a speed reaching signal thereof, the program is automatically started, and related functions are also activated;

and (3) stopping the program: when the numerical control system receives a main shaft stop instruction signal, the automatic cycle operation function stops.

3. The redundancy strategy method for sensorless monitoring of spindle overload according to claim 1, wherein a redundancy function subroutine is embedded in a PLC program built in the system.