CN204123200U - A kind of supersonic speed low-temperature airflow generating means for cutting process cooling - Google Patents

Abstract

The utility model discloses a supersonic low-temperature airflow generating device used for cooling in the cutting process, which comprises a high-pressure gas cylinder or an air compressor, and the output pipeline of the high-pressure gas cylinder or the air compressor is sequentially connected with a pressure reducing valve and a solenoid valve , flow valve, pressure gauge, temperature regulator, one-way valve, the one-way valve is connected to the injection assembly through a metal hose; the injection assembly includes the injection conversion joint, the contraction expansion nozzle, the contraction expansion nozzle includes the nozzle contraction section, the nozzle Three sections of throat and nozzle expansion section. It can obtain the low-temperature airflow with supersonic outlet speed, which has the characteristics of high jet speed, which improves the efficiency of cutting heat convection, and the high-speed jet has a good auxiliary effect on chip breaking and chip removal of materials. Compared with other refrigeration methods, the utility model can reduce the cost, and the consumable is low-cost high-pressure gas, and the acquisition method is simple.

Description

A supersonic low-temperature airflow generating device for cooling in cutting process

technical field

The utility model relates to the technical field of cutting processing, in particular to a supersonic low-temperature airflow generating device used for cooling in the cutting processing process.

Background technique

Efficient and clean machinery manufacturing is the future development direction of the manufacturing industry. There are many efficient and clean cutting methods in the field of cutting processing. One of the important methods is to use low-temperature gas instead of cutting fluid as the cooling medium for cutting processing. As we all know, cutting fluids are serious environmental pollution, endangering the health of operators, and some materials are difficult to break and remove chips. The use of low-temperature gas cooling cutting is of great significance especially for high-speed cutting and ultra-high-speed cutting. Due to the short life of high-speed cutting and ultra-high-speed cutting tools, more cutting heat is generated, and the low-temperature airflow can quickly take away the cutting heat and keep the tool temperature at a reasonable level. range, so that the tool maintains a high strength.

Low temperature gas cooling cutting can reduce environmental pollution, reduce product cost and improve product quality. Its core technology lies in the development of low-temperature gas generators. At present, the commonly used methods mainly include: indirect refrigeration using low-boiling point media. Since low-boiling point media such as liquid nitrogen are prepared externally, the operating cost of the entire system is high and it is not practical; indirect refrigeration with cycle compression , the refrigeration procedure is complicated and the cost is high; the vortex tube directly refrigerates, and the refrigeration efficiency is low.

Utility model content

The purpose of this utility model is to solve the above problems, to provide a supersonic low-temperature airflow generating device for cooling in the cutting process, through which the low-temperature supersonic airflow can be provided, and the used airflow is air, nitrogen, argon, helium Any one of the gas; according to different environments and processing materials, select the appropriate air flow for cutting, efficiently take away the cutting heat, and spray the cutting area with supersonic air flow, due to the high speed of the air flow, the cutting process The chip breaking and chip removal of the material are beneficial. It not only replaces the impact of the cutting fluid on the chips, but also can be sprayed to the surface of the tool at high speed, which also has an effect on inhibiting the generation of built-up edge.

In order to achieve the above object, the utility model adopts the following technical scheme: a supersonic low-temperature airflow generating device for cooling in the cutting process, including a high-pressure gas cylinder for providing high-pressure airflow, and the outlet gas transmission pipeline of the high-pressure gas cylinder is connected with High-pressure pressure relief valve, the outlet of the high-pressure pressure relief valve is connected to the solenoid valve through the gas pipeline, the solenoid valve controls the on-off of the gas circuit, and the gas pipeline at the exit of the solenoid valve is connected with a flow valve and a pressure gauge in turn, and the flow valve can adjust the air flow The flow rate, the pressure gauge is used to indicate the airflow pressure; the pressure gauge is connected to the temperature regulator that adjusts the airflow temperature through the gas transmission pipeline, and the output pipeline of the temperature regulator has a check valve to prevent backflow, and the check valve is connected to the airflow through a metal hose. Jet assembly is connected.

When the air flow used is air, the high-pressure gas cylinder is replaced by an air compressor, and other structures remain unchanged.

The nozzle assembly is fixed on the machine tool through a bracket.

The injection assembly includes a spray conversion joint and a contraction-expansion nozzle. The contraction-expansion nozzle includes three sections: a nozzle constriction section, a nozzle throat, and a nozzle expansion section; The throat is a circular arc transition, and the expansion section of the nozzle is a straight wall conical shape.

The high-pressure gas cylinder is used to provide high-pressure air flow, which is adjusted to a suitable pressure through the pressure reducing valve, and the solenoid valve is used to control the on-off of the entire air circuit. According to different cutting conditions, the air flow is adjusted through the flow valve. The airflow temperature of the nozzle is constant and adjustable, and the subsonic airflow with constant flow, pressure and temperature flows into the shrinking and expanding nozzle through the metal hose and the nozzle conversion joint. The airflow in the shrinking section of the shrinking and expanding nozzle is continuously accelerated, and the pressure and temperature decrease accordingly. And reach the speed of sound at the throat, and continue to accelerate in the expansion section, so that the low-temperature supersonic airflow is obtained at the outlet, and it is sprayed at the cutting area.

The output pressure of the pressure reducing valve is calculated according to the aerodynamic formula (1), so as to ensure that the outlet of the contracting and expanding nozzle is a supersonic airflow.

$<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; Ma</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\frac{\mathrm{<span\; class="notranslate">\; dV</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; D</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

In the formula, Ma is the gas Mach number, V is the gas flow rate, and A is the area of the pipeline.

The basic principle of shrinking and expanding nozzles to achieve supersonic airflow: From formula 1, it can be seen that when the Mach number Ma<1, Ma ² -1<0, when the nozzle area shrinks, so It must be greater than 0, that is, the speed of the subsonic airflow increases with the reduction of the area; when the Mach number Ma>1, Ma ² -1>0, when the nozzle area expands, so It must be greater than 0, that is, the speed of the supersonic airflow increases with the increase of the area.

The temperature regulator ensures that the inlet air temperature of the contracting and expanding nozzle can be adjusted, and the air inlet temperature and outlet temperature meet the gas dynamics formula (2). According to the required supersonic air flow temperature, the required inlet temperature is calculated, and the temperature is used Regulator adjustment.

$\frac{\mathrm{<span\; class="notranslate">\; T</span>}}{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; Me</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

In the formula, k is the specific heat ratio of the gas, T is the total temperature of the gas inlet, _Te is the static temperature of the gas outlet, and Me is the Mach number at the exit of the shrinking and expanding nozzle.

In this device, the outlet pressure of the shrinking and expanding nozzle is atmospheric pressure, so the inlet pressure and outlet pressure of the shrinking and expanding nozzle satisfy the formula (3), and the inlet pressure of the shrinking and expanding nozzle is calculated from this formula.

$\frac{\mathrm{<span\; class="notranslate">\; P</span>}}{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; Me</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}^{\frac{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

In the formula, P is the total pressure at the inlet of the shrinking and expanding nozzle, _Pe is the static pressure at the outlet of the nozzle, k is the specific heat ratio of the gas, and Me is the Mach number at the outlet of the shrinking and expanding nozzle.

The size of the shrinking and expanding nozzle is calculated according to the gas dynamics isentropic area formula (4) gas dynamics isentropic theory.

$\frac{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}}{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; Me</span>}}{<span\; class="notranslate">\; [</span><span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>}^{\frac{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

In the formula, A _e is the outlet area of the nozzle, and A _t is the throat area of the nozzle.

To obtain airflow at the desired temperature and velocity, the conditions that need to be met are:

1. The shrinking and expanding nozzle designed and processed according to the isentropic area formula (4).

2. The nozzle is supplied with gas at a certain temperature and pressure calculated according to formulas (2) and (3), and the temperature adjustment is completed by the temperature regulator in the system, and the pressure adjustment is controlled by the pressure reducing valve.

The beneficial effects of the utility model:

1. The device of the present invention can obtain low-temperature airflow, and can adjust the temperature and flow rate of the outlet airflow according to different pressure, temperature, and nozzle size parameters.

2. The utility model can obtain supersonic airflow at the exit speed, and has the characteristics of high spray speed, thereby improving the efficiency of cutting heat convection, and the high-speed spray has a better auxiliary effect on chip breaking and chip removal of materials.

3. The supersonic airflow sprays the cutting area. Due to the high speed of the airflow, it can be sprayed onto the surface of the tool at high speed, which also has an effect on inhibiting the generation of built-up edge.

4. A variety of gases can be used to meet different cutting conditions and cutting materials;

5. Compared with other refrigeration methods, the utility model can reduce the cost, and the consumables are low-cost high-pressure gas, and the acquisition method is simple.

6. Solve the pollution problem of cutting fluid, and at the same time achieve the effect of reducing the temperature of the cutting zone.

7. The purpose of using metal hose is to ensure that the spray assembly can move with the movement of the machine tool spindle, and the spray assembly is fixed on the bracket to ensure the relative position of the nozzle and the tool.

Description of drawings

Fig. 1 is a structural schematic diagram of a low-temperature supersonic air flow generating device;

Fig. 2 is a schematic diagram of a support structure;

Fig. 3 is a schematic diagram of an injection assembly;

Fig. 4 is a structural schematic diagram of a nozzle adapter;

Fig. 5 is a schematic diagram of the nozzle structure.

Among them, 1. Air compressor, 2. Pressure reducing valve, 3. Solenoid valve, 4. Flow valve, 5. Pressure gauge, 6. Temperature regulator, 7. Check valve, 8. Metal hose, 9. Bracket , 10, nozzle adapter, 11, contraction expansion nozzle, 11a, nozzle contraction section, 11b, nozzle throat, 11c, nozzle expansion section, 12, workpiece, 13, tool, 14, machine tool.

detailed description

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

As shown in Figure 1, a supersonic low-temperature airflow generating device used for cooling the cutting process, the airflow used is air, the device includes an air compressor 1 and a high-pressure pressure reducing valve 2 at its outlet, used to control the entire air circuit The on-off solenoid valve 3 determines the working and stopping status of the system. The air flow in the pipeline is adjusted through the flow valve 4, the pressure gauge 5 indicates the air flow pressure, and the temperature regulator 6 is used to adjust the air flow temperature so that the air flow temperature meets the contraction and expansion requirements. The relationship between the airflow temperature between the inlet and outlet of the type nozzle 11, the outlet of the temperature regulator 6 is connected to the one-way valve 7 to prevent the backflow of the airflow, and the output of the one-way valve 7 is connected to the metal hose 8 to ensure that the contraction and expansion nozzle 11 moves with the bed 14 The stroke is sufficient, the end of the metal hose 8 is connected to the nozzle conversion joint 10, and the other end of the nozzle conversion joint 10 is connected to the contraction and expansion nozzle 11.

As shown in Figure 2-4, the nozzle conversion joint 10 is fixed on the bracket 9, and the shrinkable expansion nozzle 11 is threaded on the nozzle conversion joint 10, so that the low-temperature airflow is aimed at the cutting area of the workpiece 12 and the tool 12, and the bracket 9 is fixed on the On the machine tool 14, a boss is provided in the middle of the nozzle conversion joint 10 to adjust the air flow ejected from the inside of the metal hose 8 to ensure that the air flow enters the contracting and expanding nozzle 11 along the axial direction.

As shown in FIG. 5 , the contracting and expanding nozzle 11 includes three sections: a nozzle contracting section 11 a , a nozzle throat 11 b , and a nozzle expanding section 11 c . During use, according to the requirements for the temperature and velocity of the supersonic airflow, the internal dimensions of the shrinking and expanding nozzle 11 are calculated according to the aerodynamic isentropic area formula (4), and the shrinking and expanding nozzle 11 can be manufactured, and simultaneously can be calculated according to the formula (2) , (3) Calculate the temperature and pressure required for the inlet airflow.

The output pressure of the pressure reducing valve is calculated according to the following aerodynamic formula, so as to ensure that the outlet of the shrinking and expanding nozzle is a supersonic flow.

$<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; Ma</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\frac{\mathrm{<span\; class="notranslate">\; dV</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; D</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}$

In the formula, Ma is the gas Mach number, V is the gas flow rate, and A is the area of the pipeline.

The size of the shrinking and expanding nozzle is calculated according to the following formula of gas dynamic isentropic area: gas dynamic isentropic theory.

$\frac{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}}{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; Me</span>}}{<span\; class="notranslate">\; [</span><span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>}^{\frac{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

In the formula, A _e is the outlet area of the nozzle, and A _t is the throat area of the nozzle.

For example, for a nozzle with Mach number Me=3 at the nozzle outlet, given the nitrogen gas (k=1.4) whose total inlet temperature is T=500K, and the outlet is atmospheric pressure, that is, P _e =1 bar, substituting into formulas (2) and (3) respectively, Formula (5), (6)

$\frac{\mathrm{<span\; class="notranslate">\; 500</span>}}{\mathrm{<span\; class="notranslate">\; Te</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1.4</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; 3</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

$\frac{\mathrm{<span\; class="notranslate">\; P</span>}}{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1.4</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; 3</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}^{\frac{\mathrm{<span\; class="notranslate">\; 1.4</span>}}{\mathrm{<span\; class="notranslate">\; 1.4</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

After calculation, the required total inlet pressure is P=36.73bar, Te=178.6K (-94.6°C), so it is only necessary to pass qualified high-pressure gas into the milling cutter to obtain an airflow at 3 times the speed of sound at -94.6°C.

To obtain airflow at the desired temperature and velocity, the conditions that need to be met are:

1. The shrinking and expanding nozzle designed and processed according to the isentropic area formula (4).

2. The nozzle is supplied with gas at a certain temperature and pressure calculated according to formulas (2) and (3), and the temperature adjustment is completed by the temperature regulator in the system, and the pressure adjustment is controlled by the pressure reducing valve.

Low-temperature milling Ti-6Al-4V experiments show that low-temperature milling can significantly improve the service life of the tool; low-temperature cutting nickel-based superalloy experiments show that this method can greatly improve the service life of the tool and the quality of the machined surface.

Although the specific implementation of the utility model has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the utility model. Those skilled in the art should understand that on the basis of the technical solution of the utility model, those skilled in the art do not need to Various modifications or deformations that can be made with creative efforts are still within the protection scope of the present utility model.

Claims (6)

1. the supersonic speed low-temperature airflow generating means for cutting process cooling, it is characterized in that, comprise gas cylinder, described gas cylinder outlet is connected with pressure-reducing valve entrance by air delivering pipeline, described pressure-reducing valve outlet is by the magnetic valve of the whole gas path on-off of air delivering pipeline connection control, described magnetic valve is connected with flow valve by air delivering pipeline, described flow valve outlet is by air delivering pipeline Bonding pressure table, described Pressure gauge connects the thermoregulator regulating gas flow temperature by air delivering pipeline, the air delivering pipeline of described thermoregulator outlet is connected with check valve, described check valve is connected with ejection assemblies by metal hose,

Described ejection assemblies comprises injection crossover sub, shrinkage expansion type nozzle, and described shrinkage expansion type nozzle comprises nozzle contraction section, nozzle throat, nozzle divergence section three sections; Described nozzle contraction section is the taper of linear pattern wall, and described nozzle throat is arc transition, described nozzle divergence section is the taper of linear pattern wall;

Described thermoregulator ensures that shrinkage expansion type nozzle entrance gas flow temperature is adjustable.

2. the supersonic speed low-temperature airflow generating means for cutting process cooling, it is characterized in that, comprise air compressor, described air compressor outlet is connected with pressure-reducing valve entrance by air delivering pipeline, described pressure-reducing valve outlet is by the magnetic valve of the whole gas path on-off of air delivering pipeline connection control, described magnetic valve is connected with flow valve by air delivering pipeline, described flow valve outlet is by air delivering pipeline Bonding pressure table, described Pressure gauge connects the thermoregulator regulating gas flow temperature by air delivering pipeline, the air delivering pipeline of described thermoregulator outlet is connected with check valve, described check valve is connected with ejection assemblies by metal hose,

Described ejection assemblies comprises injection crossover sub, shrinkage expansion type nozzle, described shrinkage expansion type nozzle comprises nozzle contraction section, nozzle throat, nozzle divergence section three sections, described nozzle contraction section is the taper of linear pattern wall, and described nozzle throat is arc transition, described nozzle divergence section is the taper of linear pattern wall;

Described thermoregulator ensures that shrinkage expansion type nozzle entrance gas flow temperature is adjustable.

3. as claimed in claim 1 a kind of for cutting process cooling supersonic speed low-temperature airflow generating means, it is characterized in that, the air-flow main component in described gas cylinder is any one in nitrogen, argon gas, helium.

4. as claimed in claim 2 a kind of for cutting process cooling supersonic speed low-temperature airflow generating means, it is characterized in that, air-flow used is air.

5. as claimed in claim 1 or 2 a kind of for cutting process cooling supersonic speed low-temperature airflow generating means, it is characterized in that, described injection crossover sub is connected by screw thread with shrinkage expansion type nozzle.

6. as claimed in claim 1 or 2 a kind of for cutting process cooling supersonic speed low-temperature airflow generating means, it is characterized in that, described nozzle crossover sub inside middle is provided with boss.