Temperature monitoring device of five-axis precision machining tool based on LabVIEW

Abstract

The utility model relates to a temperature monitoring device, belongs to the technical field of machine tool temperature monitoring, and particularly relates to a temperature monitoring device of a five-axis precision machining machine tool based on LabVIEW. The temperature monitoring device of the five-axis precision machining machine tool based on LabVIEW comprises a machine tool body, a lower computer and an upper computer, the machine tool body comprises a machine tool stand column, a spindle box, a spindle end and a spindle motor, and temperature sensors are installed on the machine tool stand column, the spindle box, the spindle end and the spindle motor respectively. The lower computer adopts a single-chip microcomputer, corresponding pins of the single-chip microcomputer are connected with a plurality of temperature sensors, and temperature measuring circuits are connected between the temperature sensors and the single-chip microcomputer. The upper computer adopts a computer with a LabVIEW interface, and the computer is connected with the single-chip microcomputer and the monitoring module. Temperature data of the temperature sensors at the multiple positions are transmitted to the computer through the single-chip microcomputer, and the computer sends the temperature data and preset data to the monitoring module.

Description

Technical Field

[0001] This utility model relates to a temperature monitoring device, belonging to the field of machine tool temperature monitoring technology, specifically to a temperature monitoring device for a five-axis precision machining tool based on LabVIEW. Background Technology

[0002] With the development of five-axis precision machining technology, five-axis machine tools are being used more and more widely in industries such as aerospace, automotive manufacturing, and mold processing. These industries require extremely high machining accuracy, and the machining accuracy of five-axis precision machine tools depends not only on the mechanical structure, control system, and tool performance, but also on the effects of thermal deformation. In particular, temperature changes in the spindle motor and torque motor can cause thermal expansion of various machine tool components, thus affecting machining accuracy.

[0003] To effectively address these issues, modern five-axis precision machine tools typically employ temperature compensation technology to counteract the effects of thermal expansion caused by temperature changes. Currently, many machine tools use temperature monitoring devices that simply measure the surface temperature of the spindle motor or the temperature of the coolant. While these temperature data can reflect certain temperature trends, they cannot comprehensively and accurately reflect the temperature changes of critical machine tool components, especially the torque motor and other core components.

[0004] Therefore, existing temperature compensation systems typically employ simple, preset temperature compensation models, failing to dynamically adjust based on real-time data under different operating conditions. This static compensation method cannot cope with temperature variations in complex processing environments.

[0005] In view of the above, in order to overcome the above technical problems, this utility model designs a temperature monitoring device for a five-axis precision machining tool based on LabVIEW, which solves the above technical problems. Summary of the Invention

[0006] The technical objective of this invention is to ensure the high precision and stability of a five-axis precision machining tool under different working conditions by collecting temperature data of key machine tool components in real time, using a compensation algorithm for dynamic temperature compensation, and effectively monitoring the operating status of the cooling system.

[0007] To achieve the above-mentioned technical objectives, this utility model provides the following technical solution:

[0008] The present invention provides a temperature monitoring device for a five-axis precision machining tool based on LabVIEW, comprising a machine tool body, a lower-level computer, and a higher-level computer.

[0009] The machine tool body includes a machine tool column on which temperature sensors are respectively installed, a spindle box, a spindle end, and a spindle motor.

[0010] The lower-level machine is a microcontroller, and the corresponding pins of the microcontroller are connected to multiple temperature sensors. A temperature measurement circuit is connected between the temperature sensors and the microcontroller.

[0011] The host computer is a computer with a LabVIEW interface, which is connected to a microcontroller and a monitoring module.

[0012] Temperature data from multiple temperature sensors are transmitted to the computer via a microcontroller. The computer then sends the temperature data and preset data to the monitoring module, which stores and compares the temperature data and preset data.

[0013] The temperature measuring circuit includes a dual operational amplifier, a constant current source, a voltage divider circuit, and a filter circuit. The input terminal of the dual operational amplifier is connected to the output terminal of the voltage divider circuit. The constant current source is used to provide a stable reference voltage for the voltage divider circuit. The input terminal of the voltage divider circuit is connected to the temperature sensor.

[0014] Preferably, the output terminal of the dual operational amplifier is connected to the corresponding pin of the microcontroller, and a filter circuit is connected between the dual operational amplifier and the microcontroller.

[0015] Preferably, the connection circuits of the two single-sided amplifiers of the dual operational amplifier are identical and are used to connect temperature sensors at different locations.

[0016] Various types of high-precision temperature sensors (PT1000, PT100 RTD, PCT thermistor, and KTY84 semiconductor temperature sensor) are used at different locations for temperature monitoring of the machine tool column, spindle box, spindle end, and spindle motor. The temperature sensors are installed in appropriate positions to ensure the representativeness and comprehensiveness of the collected temperature data. Sensor selection is based on their temperature measurement accuracy, response speed, and adaptability, enabling them to withstand high temperatures and mechanical vibrations. The temperature signals collected by the sensors are transmitted to the main controller in real time via a data transmission interface (Modbus standard communication protocol).

[0017] Preferably, the constant current source is a TL431, and the TL431 and resistors R20 and R21 generate a 3V reference voltage. The temperature sensor is a PT1000, PT100 RTD, PCT thermistor, or KTY84 semiconductor temperature sensor. Resistors R18, R17, and R19, along with the Pt1000 temperature sensor, form a measuring bridge, wherein resistors R18 and R17 have equal resistance values.

[0018] When the resistance value of the temperature sensor and the resistance value of R19 are not equal, the measuring bridge outputs a millivolt-level differential voltage signal. The differential voltage signal is amplified by a single-sided amplifier of a dual operational amplifier and outputs a voltage signal of the desired magnitude. The voltage signal is then input to the microcontroller.

[0019] Preferably, the output terminals of the measuring bridge are connected to the positive and negative terminals of the single-sided amplifier, and the positive and negative terminals of the single-sided amplifier are respectively connected in series with resistors R9 and R7 of equal resistance. The output terminals of resistors R9 and R7 are respectively connected in parallel with resistors R10 and R15 of equal resistance.

[0020] Preferably, the output terminal of the resistor R15 is connected in series with the output terminal of the single-sided amplifier, and is connected to the microcontroller through a filter circuit.

[0021] Preferably, the filter circuit includes a 100nF capacitor C2, which is connected in parallel to the output of the single-sided amplifier.

[0022] After receiving the signal, the host computer processes the data using a preset message protocol to obtain the temperature and displays the temperature curve in real time. Simultaneously, it stores the current temperature in an Excel spreadsheet for easy monitoring of the machine's operating status later. The host computer can also monitor the cooling system's operating status in real time. By setting a coolant temperature range, the host computer will issue an alarm signal when the coolant temperature exceeds the limit, alerting the operator to take timely action.

[0023] The monitoring module includes a PLC controller and an alarm. The input terminal of the PLC controller is connected to a computer, and the output terminal is connected to the alarm, which is used to control the alarm to start.

[0024] Preferably, the alarm is an indicator light with a buzzer U3.

[0025] Compared to existing technologies, the temperature monitoring device for a five-axis precision machine tool based on LabVIEW described above has the following advantages:

[0026] This invention utilizes various types of high-precision temperature sensors installed on the machine tool column, spindle box, spindle end, and spindle motor. The sensors are strategically positioned to ensure the representativeness and comprehensiveness of the collected temperature data. The temperature signals collected by the sensors are transmitted in real-time to the main controller via a data transmission interface (Modbus standard communication protocol). This system enables real-time acquisition of temperature data from key machine tool components, utilizes advanced compensation algorithms for dynamic temperature compensation, and includes a monitoring module to ensure timely system shutdown when the temperature exceeds the limit, thus improving system safety. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] The above and other aspects of the present invention will now be described by way of example only, with reference to the accompanying drawings, in which:

[0029] Figure 1 This is a schematic diagram of the machine tool of this utility model;

[0030] Figure 2 This is a schematic diagram of the system flow of this utility model;

[0031] Figure 3 This is the flowchart of the host computer system of this utility model;

[0032] Figure 4 This is a flowchart of the lower-level machine of this utility model;

[0033] Figure 5 This is a schematic diagram of the temperature measuring circuit of this utility model;

[0034] Figure 6 This is the circuit diagram of the alarm device of this utility model. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0037] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0038] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0039] In the description of this utility model, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end", "first end", "tail end", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of this utility model and simplify the description. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0040] like Figures 1-5 As shown, this embodiment provides a temperature monitoring device for a five-axis precision machining tool based on LabVIEW, including the machine tool body and a microcontroller. A host computer developed based on LabVIEW is responsible for data processing and real-time display of the temperature of various parts of the machine tool, and triggers an alarm when the temperature is outside the set range. The microcontroller, using CH32F103C8T6 as its core control unit, is responsible for data acquisition and transmission to the host computer for the entire system.

[0041] like Figure 1 As shown, the machine tool body includes a machine tool column on which temperature sensors are respectively mounted, a spindle box, a spindle end, and a spindle motor; as shown Figure 1 As shown, T1 is the temperature at the lower end of the spindle bearing, T2 is the temperature of the spindle motor, T3 is the temperature of the spindle box, and T4 is the ambient temperature.

[0042] The lower-level machine uses a CH32 microcontroller, and four temperature sensors are connected to the corresponding pins of the microcontroller. A temperature measurement circuit is connected between the temperature sensors and the microcontroller.

[0043] The host computer communicates with the CH32 microcontroller on the temperature acquisition board via RS485 and Modbus protocols, parses the received messages, displays the current temperature of each part, and triggers alarms based on set thresholds. The temperature data is stored in a table. The CH32 microcontroller is connected to five-axis lathe motor temperature sensors PT1000, PT100, PCT, and KTY84. The host computer is a computer with a LabVIEW interface, which is connected to the microcontroller and the monitoring module.

[0044] In this embodiment, the microcontroller is powered by a lithium battery, and a high-power DC-DC power module is connected to the lithium battery. The high-power DC-DC power module is connected to the CH32 microcontroller. Specifically, the CH32 microcontroller's chip model is CH32F103C8T6.

[0045] The LabVIEW-based host computer uses the VISA serial port to implement the Modbus protocol, processes the acquired data, and displays it in real time. It calculates the compensation temperature based on a compensation function and issues an alarm when the temperature exceeds a high-temperature threshold. Temperature data from four temperature sensors is transmitted to the computer via a CH32 microcontroller. The computer then sends the temperature data and preset data to the monitoring module, which stores and compares the temperature data and preset data.

[0046] like Figure 5 As shown, the temperature measuring circuit includes a dual operational amplifier, a constant current source, a voltage divider circuit, and a filter circuit. The input terminal of the dual operational amplifier is connected to the output terminal of the voltage divider circuit. The constant current source is used to provide a stable reference voltage for the voltage divider circuit. The input terminal of the voltage divider circuit is connected to the temperature sensor.

[0047] The PT1000 temperature sensor works by measuring its resistance and then calculating the temperature change. The resistance of the PT1000 changes with temperature, typically approximated by a linear relationship. The resistance-temperature relationship of the PT1000 can be expressed by the following formula: R = R0(1 + AT + BT) 2 ).

[0048] In the formula: R0 is the resistance value at 0 degrees Celsius; A and B are both scale constants.

[0049] The output of the dual operational amplifier is connected to the corresponding pin of the microcontroller, and a filter circuit is connected between the dual operational amplifier and the CH32 microcontroller.

[0050] The two single-sided amplifiers of the dual operational amplifier have the same connection circuit and are used to connect temperature sensors in different locations.

[0051] The constant current source uses a TL431, which, along with resistors R20 and R21, generates a 3V reference voltage. The temperature sensor uses a PT1000, PT100 RTD, PCT thermistor, and KTY84 semiconductor temperature sensor. Resistors R18, R17, and R19, along with the Pt1000 temperature sensor, form a measuring bridge, where resistors R18 and R17 have equal resistance values.

[0052] When the resistance values ​​of the temperature sensor and R19 are not equal, the measuring bridge outputs a millivolt-level differential voltage signal. After the differential voltage signal is amplified by the single-sided amplifier of the dual operational amplifier, it outputs a voltage signal of the desired magnitude, which is then input to the microcontroller.

[0053] The output terminals of the measuring bridge are connected to the positive and negative terminals of a single-sided amplifier, respectively. The positive and negative terminals of the single-sided amplifier are also connected in series with resistors R9 and R7 of equal resistance, respectively. The output terminals of resistors R9 and R7 are also connected in parallel with resistors R10 and R15 of equal resistance, respectively.

[0054] The output of resistor R15 is connected in series with the output of the single-sided amplifier, and is connected to the microcontroller through a filter circuit.

[0055] The filter circuit includes a 100nF capacitor C2, which is connected in parallel to the output of the single-sided amplifier.

[0056] like Figure 6 As shown, the monitoring module includes a PLC controller and an alarm. The input terminal of the PLC controller is connected to the computer for communication, and the output terminal is connected to the alarm for communication, used to control the alarm to start. The alarm is specifically configured with an indicator light and a buzzer U3. One end of the buzzer U3 is connected to the power supply, and the other end is connected to the emitter of a PNP transistor Q1. The base of transistor Q1 is connected in series with a protective resistor and then connected to the output port of the PLC controller. The collector of transistor Q1 is grounded.

[0057] The specific operating steps of the above-mentioned temperature monitoring device for a five-axis precision machine tool based on LabVIEW are as follows:

[0058] S1. System Initialization: The LabVIEW host computer startup, CH32 microcontroller startup, communication interface configuration, sensor and actuator initialization are executed sequentially, and a system self-test is performed.

[0059] S2. Then, the lithium battery is activated to prepare for power supply;

[0060] S3. Collect various data through sensors, then preprocess the collected data, and filter and calibrate the collected data;

[0061] S4. During operation, the system status is monitored, and the temperature status of the spindle motor and column is monitored in real time.

[0062] S5. After detecting an anomaly, implement the corresponding handling measures;

[0063] S6. User interaction: A host computer based on LabVIEW, providing a user interface to display the temperature of each part in real time and provide high and low temperature alarms.

[0064] S7. Data recording and analysis: Record operational data and perform data analysis to optimize system performance;

[0065] S8. System shutdown, safely shut down the system, shut down the temperature detection system, and perform a safety check.

[0066] Although the present disclosure has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to the embodiments of the present disclosure, which will be obvious to those skilled in the art. Therefore, such modifications or improvements made without departing from the spirit of the present disclosure are all within the scope of protection claimed by the present disclosure.

[0067] The above is merely a description of the present disclosure, and modifications may be made to the present invention in light of the above detailed description. The terminology used in the appended claims should not be construed as limiting the present invention to the specific embodiments disclosed in the specification. Rather, the scope of the present invention will be fully defined by the appended claims, which will be interpreted according to established principles of claim interpretation.

Claims

1. A temperature monitoring device for a LabVIEW-based five-axis precision machining machine tool, characterized in that, The machine tool body and the single-chip microcomputer are included. The machine tool body includes a machine tool column, a spindle box, a spindle end and a spindle motor, and the machine tool column, the spindle box, the spindle end and the spindle motor are all installed with temperature sensors. The single-chip microcomputer is connected with a plurality of temperature sensors through corresponding pins, and a temperature measurement circuit is connected between the temperature sensors and the single-chip microcomputer. The temperature measurement circuit includes a double operational amplifier, a constant current source, a voltage dividing circuit and a filter circuit, the input end of the double operational amplifier is connected with the output end of the voltage dividing circuit, the constant current source is used to provide a stable reference voltage for the voltage dividing circuit, and the input end of the voltage dividing circuit is connected with the temperature sensor. The output end of the double operational amplifier is connected with the corresponding pin of the single-chip microcomputer, and the filter circuit is connected between the double operational amplifier and the single-chip microcomputer. The connection circuits of the two single-side amplifiers of the double operational amplifier are the same and are used to connect temperature sensors at different positions.

2. The temperature monitoring device for LabVIEW based 5-axis precision machining tool according to claim 1, wherein, The constant current source adopts TL431, the constant current source TL431 and resistors R20 and R21 generate a reference voltage of 3V; the temperature sensor adopts PT1000, resistors R18, R17 and R19 and the temperature sensor Pt1000 constitute a measurement bridge, wherein the resistances of resistors R18 and R17 are equal. When the resistance value of the temperature sensor Pt1000 and the resistance value of R19 are not equal, the measurement bridge outputs a millivolt-level differential pressure signal, the differential pressure signal is amplified by the single-side amplifier of the double operational amplifier to output a voltage signal of an expected size, and the voltage signal is input into the single-chip microcomputer.

3. The temperature monitoring device for LabVIEW based 5-axis precision machining tool as claimed in claim 2, wherein, The output end of the measurement bridge is connected with the positive and negative ends of the single-side amplifier respectively, and the positive and negative ends of the single-side amplifier are further connected with resistors R9 and R7 with equal resistance values in series respectively, and the output ends of the resistors R9 and R7 are further connected with resistors R10 and R15 with equal resistance values in parallel respectively.

4. The temperature monitoring device for LabVIEW based 5-axis precision machining tool according to claim 3, wherein, The output end of the resistor R15 is connected with the output end of the single-side amplifier in series, and is connected with the single-chip microcomputer through the filter circuit.

5. The temperature monitoring device for LabVIEW based 5-axis precision machining tool as claimed in claim 4, wherein, The filter circuit includes a 100nF capacitor C2, and the capacitor C2 is connected in parallel with the output end of the single-side amplifier.

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