CN111786614A - High-precision coordinate boring servo motor temperature active control device and control method - Google Patents

Abstract

The high-precision coordinate boring servo motor temperature active control device comprises a servo motor body, wherein an adjustable mounting support is arranged on the outer side of the servo motor body, a control proportional valve is arranged on the adjustable mounting support and is arranged at a cooling gas path main outlet, an annular gas path is connected to the rear portion of the control proportional valve and is used for forming a redundant cooling pipeline, an adjustable gas blowing opening is formed in the adjustable mounting support, the rear end of the direction adjustable gas blowing opening is connected with a gas flow monitoring element, the gas flow monitoring element is used for detecting the actual gas flow of each cooling opening, the gas flow monitoring element is connected to the main annular gas path through a pipeline, cooling gas flow is output to the annular gas path through the control proportional valve, and the direction adjustable gas blowing opening carries out covering cooling on the servo motor body.

Description

High-precision coordinate boring servo motor temperature active control device and control method

technical field

The invention relates to the technical field of high-precision numerical control horizontal coordinate boring machines, in particular to a high-precision coordinate boring servo motor temperature active control device and a control method thereof.

Background technique

High-precision CNC horizontal coordinate boring machines have extremely strict requirements on the use of ambient temperature, ambient temperature field, and the high temperature and temperature rise speed of the machine tool's own rotating heating parts. If the ambient temperature, ambient temperature field, and the temperature of the rotating heating parts of the machine tool are greatly disturbed or continuously changed, it will greatly affect the actual performance of the machine tool, and ultimately affect the comprehensive cutting accuracy of the machine tool, which will seriously affect the position of the workpiece to be processed. Deviations result in the scrapping of the workpiece.

The traditional high-precision CNC horizontal coordinate boring machine is used in a constant temperature workshop. Due to the strict control of the external ambient temperature and temperature field, the fluctuation of the external temperature field has little effect on the performance of the machine tool. At the same time, the machine body is also independently equipped with a variety of temperature control systems for rotating heating components. For example, the feed shaft screw is equipped with a central water-cooled screw, the screw seat and bearing are equipped with a water-cooling device, and the spindle is equipped with a circulating oil-cooling or water-cooling system, which is strictly controlled. The heat generated by the rotating heating parts of the machine tool itself during the movement. A passive temperature compensation device is also configured for each feed axis to compensate for the coordinate drift caused by temperature and temperature field changes, so as to ensure the positioning and repeated positioning accuracy of the machine tool. However, in all kinds of temperature control, there is no effective active control of the heat generated by the servo motor of the feed axis and spindle during use, and the heat generated during operation is allowed to have an impact on the performance of the machine tool. It performs effective closed-loop control to mitigate and ultimately eliminate the effects.

SUMMARY OF THE INVENTION

In order to overcome the deficiencies of the above-mentioned prior art, the object of the present invention is to provide a high-precision coordinate boring servo motor temperature active control device and a control method thereof, and the temperature of the servo motor in different states is fused with the ambient temperature according to different control methods, And accelerate the fusion of the microscopic annular temperature field around the servo motor, and finally control the temperature rise and speed of the motor, greatly reducing the thermal deformation of the machine tool caused by the temperature rise of the motor, thereby ensuring the machining accuracy of the machine tool.

In order to achieve the above object, the technical scheme adopted in the present invention is:

The high-precision coordinate boring servo motor temperature active control device includes a servo motor body 1, an adjustable mounting bracket 2 is arranged on the outside of the servo motor body 1, and a control proportional valve 3 is arranged on the adjustable mounting bracket 2 , the control proportional valve 3 is arranged at the total outlet of the cooling air circuit, and the rear part of the control proportional valve 3 is connected to the annular air circuit 4 to form a redundant cooling pipeline. The adjustable mounting bracket 2 is provided with adjustable debugging The air blowing port 6, the rear end of the air blowing port 6 is connected to the gas flow monitoring element 5, the gas flow monitoring element 5 is used to detect the actual air flow rate of each cooling port, and the gas flow monitoring element 5 is connected to the total annular gas path 4 through a pipeline, The cooling airflow is output to the annular air path 4 through the control proportional valve 3 , and the direction adjustable air blowing port 6 performs cover cooling on the servo motor body 1 .

The adjustable mounting brackets 2 are L-shaped, and there are four of them, which are fixedly mounted on the servo motor body 1 through adjustable bolts and nuts.

The corners of the four L-shaped adjustable mounting brackets 2 are respectively provided with four directions adjustable air blowing ports 6 .

A high-precision numerical control horizontal coordinate boring servo motor temperature active control method, comprising the following steps;

When the machine tool is powered on, the servo motor body 1 transmits the actual temperature value of the servo motor body 1 to the drive module through the motor control cable, and stores this data in the drive parameter R35 of the numerical control system. The parameters of the secondary development system are connected to the data energy block. And call the PLC program function block to read the data through the NC drive bus and store it in the PLC data area. Through the motor room temperature monitoring sensor arranged near the servo motor body 1, the ambient temperature of the micro temperature field where the servo motor body 1 is located is calculated. Input into the analog input module through the analog signal cable; at this time, the PLC program analyzes and judges the collected motor temperature and room temperature data;

If the temperature of the servo motor body 1 is lower than the room temperature at this time, it is judged again whether the temperature of the servo motor body 1 is lower than the room temperature by 2°C. At this time, if the temperature of the servo motor body 1 is lower than the room temperature by 2°C, the calculation is performed by the PLC program and controlled by the control bus. The analog output module sends out the control voltage corresponding to the program, and controls the proportional valve 3 through the analog control cable, so that the state is not connected or closed, so that the annular air path 4 has no cooling airflow, and is connected to the adjustable valve. The direction on the mounting bracket 2 can be adjusted. The air outlet 6 has no cooling airflow output; if the temperature of the servo motor body 1 is lower than room temperature but not lower than room temperature by 2°C, the PLC program controls the output of the minimum set value through the analog output module 1. The voltage value of the cooling quantity is controlled by the analog control cable to control the proportional valve 3 to be in the set minimum cooling open state, and is connected to the direction-adjustable air outlet 6 installed on the adjustable mounting bracket 2 through the annular air path 4 without cooling Airflow output, continuous pre-cooling, if the temperature of servo motor body 1 is higher than room temperature, then judge again whether the motor temperature is 2°C higher than room temperature, if the temperature of servo motor body 1 is not higher than room temperature 2°C, the PLC program will use PID control The mode adjusts the output voltage of the control proportional valve 3 in real time, and the final control direction can debug the cooling flow of the air blowing port 6; if the temperature of the servo motor body 1 is 2°C higher than the room temperature, the PLC program will control the control proportional valve 3 to fully open, and use strong The cooling airflow forces the motor to cool down, reducing the temperature of the motor to a controllable range in a short period of time.

Beneficial effects of the present invention:

The active temperature control device of the servo motor combined with the traditional screw cooling, bearing cooling and passive temperature compensation can fully guarantee the accuracy of the high-precision horizontal CNC coordinate boring machine. It is a system integration technology that combines mechanical design, electrical control, and pneumatic control. Different from the traditional control method of letting the temperature of the motor rise and then compensating for the change, the active temperature control of the servo motor can clamp the temperature rise and speed of the motor and preprocess the temperature in advance. And in the environment where the spindle motor is installed, the microscopic temperature field is accelerated to achieve equilibrium through the disturbance of cooling airflow, and the influence caused by the increase of motor temperature is alleviated from the root cause.

Servo motor temperature active control device has been popularized and applied in the company's TGK46 series, THM46 series, TGK65 series and many other high-precision CNC horizontal coordinate boring series products, which has improved the usability of the machine tool and achieved good social and economic benefits. At the same time, this cooling control method can be applied to screw and bearing cooling instead of the traditional cooling method. However, because the servo motor temperature active control device uses a large number of analog signals, it needs to configure a considerable number of analog input and output modules, which makes the manufacturing cost too high. In ordinary CNC machine tools whose use accuracy is not very strict, the detection and control components can not be used. Equipped with the cooling device body, it can also achieve a good effect of clamping the temperature rise of the motor.

Description of drawings

FIG. 1 is a schematic diagram of the overall structure of the present invention.

FIG. 2 is an interconnection diagram of the electrical control of the active temperature control device of the servo motor according to the present invention.

Fig. 3 is the PLC control flow chart of the active temperature control device of the servo motor according to the present invention.

FIG. 4 is a schematic diagram of the adjustable mounting bracket 2 .

FIG. 5 is a schematic diagram of the adjustable air blowing port 6 .

FIG. 6 is a schematic diagram of the gas flow monitoring element 5 .

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1: It includes four adjustable mounting brackets 2 connected in combination, and is fixed on the servo motor body 1 with adjustable bolts and nuts. Adjust the installation of the adjustable mounting bracket 2 according to the actual size of the motor. size, to ensure stable and reliable connection, the control proportional valve 3 is installed at the general outlet of the cooling air circuit, fixed on the adjustable mounting bracket 2, and its rear is connected to the annular air circuit 4, which is used to form a redundant cooling pipeline. The corners of the four L-shaped adjustable mounting brackets 2 are respectively provided with four direction-adjustable air blowing ports 6, and the rear end of the direction-adjustable air blowing ports 6 is connected to a gas flow monitoring element 5 for detecting the actual air flow of each cooling port. The flow monitoring element 5 is connected to the general annular gas circuit 4 by means of pipes. The cooling airflow is output to the annular air path 4 through the control proportional valve 3, and through the detection feedback of the gas flow monitoring element 5, and finally the direction adjustable air blowing port 6 is used to cover the cooling of the servo motor.

The servo motor body is equipped with a mounting bracket that can be freely adjusted according to the size of the motor to adapt to any type of servo motor configured by different numerical control systems. The whole bracket is divided into four parts and connected with bolts. According to the actual size of the motor configured by different CNC systems, it is adjusted with connecting bolts, which can be reliably fixed to the outside of the servo motor. The four vertices of the mounting bracket are equipped with cooling output ports that can freely adjust the cooling direction, which are used to output the cooling airflow for all-round coverage cooling of the servo motor. The connection between each cooling outlet adopts a redundant design to form a ring-shaped pipeline connection to prevent the normal blowing and cooling caused by the blockage of the single-point pipeline. A gas flow monitoring element is installed at each cooling outlet to monitor the pressure air flow of each cooling outlet in real time to form a closed-loop monitoring of the gas circuit. The proportional valve is arranged at the output port of the total gas path. The PLC program reads the state of each state and outputs the corresponding control signal according to the set control model to control the opening state of the proportional valve.

As shown in Figure 2: a set of servo motor temperature active control device is equipped with one analog temperature sensor, four analog gas flow sensors, and one analog control proportional valve. All servo motors of the machine tool are equipped with a set of motor temperature active control The device will use a lot of analog input and output modules. Connect four analog gas flow sensors configured on a single device to one analog input module using shielded cables; connect a total of six analog temperature sensors configured on all devices to detect room temperature to two using shielded cables Analog input modules; connect a total of six analog control proportional valves for controlling cooling flow in all unit configurations to two analog output modules using shielded cables; this can significantly save the use of modules.

It is connected to each axis drive module by the NC drive bus, and then connected to each feed axis and spindle servo motor by the motor control cable and feedback cable. It is read in the PLC program control and borrowed from the numerical control system. The driver collects data from the internal temperature sensor of the servo motor. The received temperature signal is no longer arranged for the motor temperature sensor.

As shown in Figure 3: Using the PLC program to control the active temperature control device of the servo motor can precisely control the temperature rise and the speed of the servo motor, and effectively alleviate the influence of the heat generated by the operation of the servo motor on the machine tool. The PLC control algorithm of the servo motor temperature active control device is divided into 4 modes for discussion:

Mode 1: When the motor temperature is lower than room temperature and the temperature difference is greater than or equal to 2°C, the proportional valve is closed.

Mode 2: When the temperature of the motor is lower than room temperature and the temperature difference is less than 2°C, the proportional valve opens according to the set minimum cooling amount.

Mode 3: When the motor temperature is higher than room temperature and the temperature difference is less than 2℃, the proportional valve is controlled in real time according to the PID control mode.

Mode 4: When the motor temperature is higher than room temperature and the temperature difference is greater than 2°C, the proportional valve is fully opened, and the forced cooling mode is turned on.

When the machine tool starts to run in a normal cold state, it first reads the internal temperature of the servo motor and the ambient temperature of the actual machine tool, and compares the two temperature values to determine whether the current motor temperature is lower than the room temperature; at this time, the machine tool was powered off earlier. In the shutdown state, the detected motor temperature is the same as the room temperature, and will not be lower than the room temperature without external cooling; at this time, the PLC program outputs the proportional valve control signal according to the set minimum cooling flow to clamp the temperature rise of the servo motor. , and prevent and control the temperature rise of the motor in advance. If the machine tool is still energized and static at this time, and any feed axis and spindle do not move, the motor temperature will not increase further, but the motor temperature will be lower than room temperature with the cooling operation. When the PLC detects the motor temperature When the temperature is 2°C lower than the room temperature, the proportional valve output is closed and the cooling is cut off, because the motor temperature is too much lower than the room temperature, which will also affect the performance of the machine tool.

If the machine tool is not in a static state but performs machining and cutting motion after starting, and the motor temperature rises but does not exceed the room temperature by 2 °C, the PLC program uses the FB58 "TCONT_CP" function block in the OB35 organization block to control the continuous signal. In the temperature processing process, the FB58 function block GAIN is set to a negative value for pure cooling operation, and PID operation is enabled at the same time to control the opening state position of the proportional valve according to the actual motor temperature and room temperature as input variables for precise control. If it is detected that the motor temperature rise is too large and the motor temperature exceeds the room temperature by 2 °C, the PID adjustment function will be turned off, and the proportional valve control value will be set to the maximum value, and the cooling will be fully turned on to force the motor. Control the temperature rise of the motor to return the motor temperature to the controlled range. In this way, by adopting different control modes under different working conditions, the working condition temperature of the servo motor can be kept within a certain range, so as to alleviate the continuous change of the local temperature field of the machine tool itself caused by the temperature rise of the motor. Its local temperature field achieves a rapid equilibrium effect to ensure the consistency of machine tool performance.

Claims (4)

1. A high-precision coordinate boring servo motor temperature active control device, characterized in that it comprises a servo motor body (1), and an adjustable mounting bracket (2) is provided on the outside of the servo motor body (1), and the adjustable mounting bracket (2) is provided on the outside of the servo motor body (1). A control proportional valve (3) is arranged on the adjustable mounting bracket (2), the control proportional valve (3) is arranged at the general outlet of the cooling air circuit, and the rear of the control proportional valve (3) is connected to the annular air circuit (4), which is used for A redundant cooling pipeline is formed, the adjustable mounting bracket (2) is provided with a debuggable air blowing port (6), and the rear end of the direction-adjustable air blowing port (6) is connected to a gas flow monitoring element (5), The gas flow monitoring element (5) is used to detect the actual gas flow of each cooling port, the gas flow monitoring element (5) is connected to the total annular gas path (4) through a pipeline, and the cooling airflow is output to the annular gas path through the control proportional valve (3) (4), the direction-adjustable air blowing port (6) can coverly cool the servo motor body (1). 2. The high-precision coordinate boring servo motor temperature active control device according to claim 1, wherein the adjustable mounting bracket (2) is L-shaped, and is provided with four, through adjustable bolts and The nut is fixed on the servo motor body (1). 3. The high-precision coordinate boring servo motor temperature active control device according to claim 1, characterized in that, four directions of adjustable blowers are respectively arranged at the corners of the four L-shaped adjustable mounting brackets (2). Air port (6). 4. based on the high-precision numerical control horizontal coordinate boring servomotor temperature active control method of claim 1, is characterized in that, comprises the following steps; When the machine tool is powered on, the servo motor body (1) transmits the actual temperature value of the servo motor body (1) to the drive module through the motor control cable, and stores this data in the drive parameter R35 of the numerical control system, and the secondary development system parameters Connect the data energy block and call the PLC program function block to read the data through the NC drive bus and store it in the PLC data area. The ambient temperature of the microscopic temperature field at the location is input to the analog input module through the analog signal cable; at this time, the PLC program analyzes and judges the collected motor temperature and room temperature data; If the temperature of the servo motor body (1) is lower than the room temperature at this time, judge again whether the temperature of the servo motor body (1) is 2°C lower than the room temperature. Calculate and control the analog output module through the control bus to send out the control voltage corresponding to the program, and control the proportional valve (3) through the analog control cable, so that the state is not connected or closed, so that the annular gas circuit (4) has no cooling Air flow is connected to the direction-adjustable air outlet (6) installed on the adjustable mounting bracket (2) without cooling air output; if the temperature of the servo motor body (1) is lower than room temperature but not lower than room temperature 2 ℃, this At the same time, the PLC program controls the output of the set minimum cooling voltage value through the analog output module (1), and controls the proportional valve (3) to the set minimum cooling open state through the analog control cable. 4) Connect to the direction-adjustable air outlet (6) installed on the adjustable mounting bracket (2) without cooling air output, and continue pre-cooling. If the temperature of the servo motor body (1) is higher than room temperature at this time, judge again Whether the motor temperature is 2°C higher than room temperature, if the temperature of the servo motor body (1) is not higher than room temperature 2°C, the PLC program will use the PID control mode to adjust the output voltage of the proportional valve (3) in real time, and the final control direction can be debugged The cooling flow of the air blowing port (6); if the temperature of the servo motor body (1) is 2°C higher than the room temperature, the PLC program will control the proportional valve (3) to fully open, and the motor will be forcedly cooled with a strong cooling airflow. Reduce the motor temperature to a manageable range.

Images