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CN-118699864-B - Parameterized regulation and control system and method for gas jet cooling metal cutting zone

CN118699864BCN 118699864 BCN118699864 BCN 118699864BCN-118699864-B

Abstract

The invention relates to the field of cooling jet flow forms of compressed gas cooling, in particular to a parameterized regulation and control system and a parameterized regulation and control method for a gas jet flow cooling metal cutting area. A parameterized regulation and control method for a gas jet cooling metal cutting area is used for determining the diameter of the tail end of a cooling jet Mach disk according to requirements and preliminarily setting the front end parameters of the cooling jet. The actual position of the end of the Mach disk, the diameter and the stagnation pressure at that position are measured separately for this parameter. And calculating the coefficients k and alpha in the calculation model by combining the constructed calculation model. And then adjusting the front-end parameter pressure and the size of the nozzle caliber until the diameter of the tail end of the Mach disk is adjusted to meet the actual requirement. On the basis, the mass flow is adjusted to adjust the temperature of the jet flow until the temperature of the tail end of the Mach disk meets the minimum cooling requirement. Through the parameter adjusting thought, the region with the strongest jet cooling capacity can be fully utilized to rapidly and uniformly cool the heat generating region of the metal cutting region.

Inventors

  • ZHU LIBIN
  • XIA JIAWEI
  • PENG KAIYUAN
  • HUANG HAIHONG
  • LIU ZHIFENG

Assignees

  • 合肥工业大学

Dates

Publication Date
20260512
Application Date
20240723

Claims (10)

  1. 1. A parameterized control method for a gas jet cooled metal cutting zone, comprising the steps of: (1) Connecting a gas jet cooling device with a PLC feedback controller, and constructing a calculation model of a distance L M between the tail end position of a Mach disk formed by injecting cooling gas from the gas jet cooling device and a cooling gas outlet and a diameter d M of the tail end position of the Mach disk in the PLC feedback controller, wherein the expression is as follows (1) (2) (3) Wherein k is a proportionality coefficient, d n is the diameter of a nozzle in the gas jet cooling device, and P 0 is stagnation pressure in the gas jet cooling device; Is the ambient pressure, alpha is an empirical coefficient, gamma is a specific heat ratio, c P is a constant pressure specific heat capacity, and c V is a constant specific heat capacity; (2) Determining a diameter d M of an end position of a Mach disk required for covering a heat source according to the size of a heat generating region in a metal cutting region, wherein the Mach disk is formed by gas sprayed by the gas jet cooling device; (3) Preliminarily setting the front-end jet flow parameter of the gas jet flow cooling device when the diameter is d M , wherein the pressure of the gas in the front-end jet flow parameter when the gas is sprayed out is P, the caliber of a nozzle is d n , and the mass flow is And opening a control valve in the gas jet cooling device; (4) The actual pressure of the gas jet is regulated by a pressure stabilizing constant valve, the pressure value is controlled to be stabilized at a set pressure P, the actual mass flow of the gas jet is regulated by a mass flow controller, and the mass flow is controlled to be stabilized at a set value ; (5) Measuring the distance L M,0 between the end position of the mach disk actually formed after the cooling gas is sprayed and the cooling gas outlet and the diameter d M,0 of the end position of the mach disk actually formed by using a high-speed camera under the parameters set in the step (3); (6) Measuring the actual stagnation pressure P M,0 of the end position of the Mach disc through a temperature pressure sensor, and calculating according to the front end parameters set in the step (3) to obtain coefficients k and alpha in a calculation model of the distance L M between the end position of the Mach disc and the cooling gas outlet and the diameter d M of the end position of the Mach disc; (7) Defining a variable i, and initializing i=1; (8) The PLC feedback controller obtains the diameter of the end position of the Mach disc measured for the ith time as d M,i , and makes a difference with the diameter d M of the end position of the Mach disc which is expected to cover the heat generating area of the metal cutting area, and sets the regulation precision as delta d, and compares d M,i －d M with delta d, when d M,i －d M <0, or d M,i ＞d M and d M,i －d M > delta d, the step (9) is executed, and when d M,i ＞d M and d M,i －d M < delta d, the step (11) is executed; (9) According to the calculation model of the distance between the end position of the Mach disk and the cooling gas outlet and the diameter of the end position of the Mach disk in the step (1), and by combining the coefficients k and alpha of the calculation model in the step (6), adjusting the pressure P or the nozzle d n to change the diameter of the end of the Mach disk so that the diameter of the end position of the Mach disk meets the condition of the step (8); (10) Assigning the value of i+1 to i and returning to said step (8); (11) The PLC feedback controller obtains various parameters finally obtained in the step (9), wherein the various parameters comprise the actual pressure P at the inlet of the nozzle at the moment and the size d n of the nozzle, and the distance L M,i between the tail end position of the Mach disc and the cooling gas outlet at the moment is calculated by combining the coefficient k obtained by the calculation in the step (6); (12) Defining a variable j, and initializing j=1; (13) Measuring a stagnation temperature T M,j of the end position of the jth measured Mach disk by a temperature sensor, making a difference with an expected stagnation temperature T M , setting a regulation precision as DeltaT, comparing T M －T M,j with DeltaT, and executing the step (14) if T M,j ＞T M or T M ＞T M,j and T M －T M,j are larger than DeltaT, and executing the step (16) if T M ＞T M,j and T M －T M,j are smaller than DeltaT; (14) Increasing the mass flow of the gas jet cooling device jet by a mass flow controller To reduce stagnation temperature of the gas jet at the end position of the mach disk; (15) Assigning the value of j+1 to j, and returning to the step (13); (16) The PLC feedback controller obtains the front end parameters of the adjusted Mach disc, namely the actual pressure P at the inlet of the nozzle, the size d n of the nozzle and the mass flow of the adjusted gas And the distance L M between the end position of the mach disk and the cooling gas outlet, the diameter d M of the end position of the mach disk, and the actual stagnation temperature T M of the end position of the mach disk, and applying the adjusted parameters to the cooling of the actual metal cutting zone.
  2. 2. The parameterized control method for a gas jet cooled metal cutting zone of claim 1, wherein the Δd ranges from 5% to 20% of d M ; and/or the value range of the delta T is 5% -20% of the value range of the T M %.
  3. 3. The parameterized tuning method for gas jet cooling metal cutting zones of claim 1, wherein the Δd has a value of 5% of d M %; And/or, the value of Δt is 5% of T M .
  4. 4. A parameterized conditioning system for a gas jet cooled metal cutting zone conditioned by a parameterized conditioning method for a gas jet cooled metal cutting zone according to any of claims 1-3, characterized in that the parameterized conditioning system for a gas jet cooled metal cutting zone comprises: The gas jet cooling device comprises an injection device (1), a parameter adjusting device and an acquisition device, wherein the injection device (1) is arranged on the parameter adjusting device, the acquisition device is arranged on one side of the parameter adjusting device, a jet field (4) is formed between the acquisition device and the parameter adjusting device by gas injected by the injection device (1), a cutting area in metal cutting is arranged in the jet field (4), the injection device (1) is used for injecting cooling gas into the jet field (4) and forming a Mach disc in the jet field (4) to realize cooling of the metal cutting area, and the parameter adjusting device is used for adjusting various parameters in the process of injecting the cooling gas by the injection device (1) so that the diameter of the injection device (1) at the tail end position of a Mach disc formed by the jet field (4) can cover a heat generating area in the metal cutting area; The PLC feedback controller is respectively connected with the spraying device (1), the parameter adjusting device and the acquisition device, and is used for receiving data collected by the acquisition device and controlling various parameters of the parameter adjusting device to the spraying device (1) in the process of spraying cooling gas through the received data.
  5. 5. Parameterized conditioning system for gas jet cooling metal cutting zones according to claim 4, characterized in that the injection device (1) comprises a gas delivery pipe (11), a nozzle exchange device (12) and a nozzle (13), one end of the nozzle exchange device (12) is connected to the gas delivery pipe (11), the other end of the nozzle exchange device (12) is connected to the nozzle (13), the gas delivery pipe (11) is used for delivering compressed gas to the nozzle (13) through the nozzle exchange device (12), the nozzle (13) is used for injecting cooling gas to the jet field (4), and the injected gas is used for forming a mach disk in the jet field (4) for cooling metal cutting zones placed in the jet field (4).
  6. 6. The parameterized control system for a gas jet cooling metal cutting zone according to claim 5, wherein the parameter adjusting means comprises a mass flow controller (2), a steady-state valve (3) and a control valve (8), the control valve (8) is installed at an inlet of the gas delivery pipe (11), the control valve (8) is used for controlling opening and closing of the gas delivery pipe (11), the steady-state valve (3) is installed on the gas delivery pipe (11) and is arranged between the control valve (8) and the nozzle replacing device (12), the steady-state valve (3) is used for adjusting the pressure of cooling gas entering the nozzle (13) on the gas delivery pipe (11), the mass flow controller (2) is installed on the gas delivery pipe (11), the steady-state valve (3) is arranged between the steady-state valve (2) and the nozzle replacing device (12), and the mass flow controller (2) is used for controlling the mass flow of the gas delivery pipe (11) to be small.
  7. 7. The parameterized control system for gas jet cooling metal cutting areas according to claim 5, wherein the gas jet cooling device further comprises a sliding table (7), the injection device (1) is provided with a sliding plate (14), the nozzle changing device (12) is fixedly mounted on the sliding plate (14), the sliding plate (14) is slidably mounted on the sliding table (7), and the sliding plate (14) is used for adjusting the distance between the nozzle (13) and the collecting device.
  8. 8. The parameterized control system for gas jet cooling metal cutting area according to claim 7, wherein the collecting device comprises a high-speed camera (6), a temperature pressure sensor (51), a sensor fixing device (9) and a signal collecting card (5), wherein the high-speed camera (6) is arranged along the vertical direction of the central axis of the sliding table (7), the high-speed camera (6) faces the jet field (4), the temperature pressure sensor (51) is mounted on the sensor fixing device (9) and is connected with the signal collecting card (5), the signal collecting card (5) is arranged on one side of the high-speed camera (6) far away from the nozzle (13), the sensor fixing device (9) is arranged on the central axis of the sliding table (7), the temperature pressure sensor (51) faces the nozzle (13), the temperature sensor (51) is used for measuring the temperature of the end position of a disk formed after the gas is jetted by the nozzle (13) and the end position of the disk, and the diameter of the disk is used for measuring the end position of the disk (13) and the end position of the disk (1) is used for measuring the diameter of the end position of the disk.
  9. 9. Parameterized conditioning system for gas jet cooling metal cutting zones according to claim 8, characterized in that the high speed camera (6) is highly uniform with the nozzle (13) in the vertical direction of the jet field (4); And/or the center of the cooling gas sprayed by the nozzle (13) at the tail end position of the Mach disk formed by the jet field (4) coincides with the center of the temperature and pressure sensor (51).
  10. 10. The parameterized control system for gas jet cooling metal cutting zones according to claim 8, characterized in that the distance between the nozzle (13) and the temperature pressure sensor (51) is 0 mm-3 mm.

Description

Parameterized regulation and control system and method for gas jet cooling metal cutting zone Technical Field The invention relates to the field of cooling jet flow morphology of compressed gas cooling, in particular to a parameterized regulation and control system and a parameterized regulation and control method for a gas jet flow cooling metal cutting area. Background Metal cutting is a material removal additive method in metal forming processes, which still occupies a significant proportion in today's machine manufacturing. The metal cutting process is the process of interaction of a workpiece and a prop. The cutter cuts redundant metal from the workpiece to be processed, and on the premise of controlling the production rate and the cost, the workpiece is enabled to obtain geometric precision, dimensional precision and surface quality which meet the design and process requirements. To achieve this, a relative movement, i.e. a cutting movement, is required between the workpiece and the tool, which is provided by a metal cutting machine. The machine tool, the clamp, the tool and the workpiece form a machining process system. The gas jet cooling technology is a high-efficiency cooling technology which applies compressed gas to cooling. According to the Joule-Thom effect, the technology realizes the heat removal of the metal cutting area by spraying compressed gas into the air and expanding and absorbing the heat from high pressure to normal pressure. In the prior art, the metal cutting area is cooled by gas jet, and the parameters such as the jet field temperature or the gas flow rate in the gas jet cooling device are generally adjusted by manual experience so as to achieve the aim of improving the cooling effect. However, the manual parameter adjustment mode in the prior art has low efficiency, and the gas jet cooling device after adjusting the parameters still has difficulty in rapidly cooling the metal cutting area, so that the cooling effect of the whole gas jet device is poor. Disclosure of Invention In order to solve the problem that the metal cutting area can not be well cooled by the gas jet cooling device after the parameters such as the jet field temperature or the gas flow rate are regulated in the prior art, the invention provides a regulating method for regulating the parameters of the gas jet cooling metal cutting area. In order to achieve the aim, the technical scheme adopted by the invention is that the method for regulating and controlling the parameters of the gas jet cooling metal cutting area comprises the following steps: (1) Connecting a gas jet cooling device with a PLC feedback controller, and constructing a calculation model of a distance L M between the tail end position of a Mach disk formed by injecting cooling gas from the gas jet cooling device and a cooling gas outlet and a diameter d M of the tail end position of the Mach disk in the PLC feedback controller, wherein the expression is as follows (1) (2) (3) Wherein k is a proportionality coefficient, d n is the diameter of a nozzle in the gas jet cooling device, and P 0 is stagnation pressure in the gas jet cooling device; Is the ambient pressure, alpha is an empirical coefficient, gamma is a specific heat ratio, c P is a constant pressure specific heat capacity, and c V is a constant specific heat capacity; (2) Determining a diameter d M of an end position of a Mach disk required for covering a heat source according to the size of a heat generating region in a metal cutting region, wherein the Mach disk is formed by gas sprayed by the gas jet cooling device; (3) Preliminarily setting the front-end jet flow parameter of the gas jet flow cooling device when the diameter is d M, wherein the pressure of the gas in the front-end jet flow parameter when the gas is sprayed out is P, the caliber of a nozzle is d n, and the mass flow is And opening a control valve in the gas jet cooling device; (4) The actual pressure of the gas jet is regulated by a pressure stabilizing constant valve, the pressure value is controlled to be stabilized at a set pressure P, the actual mass flow of the gas jet is regulated by a mass flow controller, and the mass flow is controlled to be stabilized at a set value ; (5) Measuring the distance L M,0 between the end position of the mach disk actually formed after the cooling gas is sprayed and the cooling gas outlet and the diameter d M,0 of the end position of the mach disk actually formed by using a high-speed camera under the parameters set in the step (3); (6) The actual stagnation pressure P M,0 of the end position of the Mach plate is measured by a temperature pressure sensor, and coefficients k and alpha in a calculation model of the distance L M between the end position of the Mach plate and the cooling gas outlet and the diameter d M of the end position of the Mach plate are calculated according to the front end parameters set in the step (3). (7) Defining a variable i, and initializing i=1; (8) T