CN213673166U - Mill trace lubricating system - Google Patents

Abstract

The application provides a milling minimal quantity lubrication system, which relates to the field of milling lubrication and comprises an external cooling system and an internal cooling system, wherein the external cooling system and the internal cooling system are jointly connected with a cutting fluid supply source through a reversing device; and comparing the switching threshold values of the internal cooling and the external cooling which are set at the beginning to obtain the most suitable cooling and lubricating mode under the machining working condition of the machine tool, and controlling the internal cooling and external cooling system by the control center according to the obtained result to realize the intelligent switching of the cooling and lubricating modes of the internal cooling and the external cooling.

Description

Mill trace lubricating system

Technical Field

The application relates to the field of milling lubrication, in particular to a milling minimal quantity lubrication system.

Background

The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.

In machining. The cooling and lubricating modes adopted by the milling machine machining center include an internal cooling and lubricating mode and an external cooling and lubricating mode. The cooling and lubricating method of internal cooling is that the cutting fluid is supplied by a cutting fluid supply system, flows into a rotary joint of a machine tool spindle through a cutting fluid pipeline, flows into an internal cooling pipeline of the machine tool spindle through the rotary joint, and is transmitted to an internal cooling pipeline on a cutter, so that the cooling and lubricating of the cutter in the cutting process are realized. The internal cooling lubrication mode can meet the cooling lubrication of processing working conditions such as holes and grooves with large milling depth. However, the internal cooling system is only suitable for cutting under a specific machining working condition, and is expensive because the internal cooling system is a system carried by a machine tool, so that economic waste can be caused when the working condition that internal cooling is not needed in machining. The cooling and lubricating mode of external cooling comprises pouring and micro-lubricating technologies. In the casting type, a cutting fluid is generally supplied from a cutting fluid supply system, and flows into an external cooling nozzle through an external cooling pipe, thereby cooling and lubricating a machining region of a tool-workpiece from the outside. The cooling and lubricating in the mode can well play a role in cooling and lubricating a machining area, and can also play a role in removing chips and cleaning the cutter. Compared with an internal cooling and lubricating mode, the pouring type cooling and lubricating mode cannot meet the cooling and lubricating requirements of machining conditions such as holes and grooves with large milling depths. In addition, the effective cooling lubrication rate of the cutting fluid is low, a large amount of cutting fluid is wasted, economic loss is caused simply, and the life health of operators is influenced because the cutting fluid contains substances harmful to human health.

Compared with a traditional pouring type external cooling lubrication mode, the micro-lubrication technology (MQL) in the field of machining is more suitable for the concepts of green manufacturing and sustainable development. The method is a technology for mixing and atomizing a trace amount of lubricating liquid, water and gas with certain pressure and then spraying the mixture to a cutting area to play a role in cooling and lubricating. The water and the high-pressure gas play a cooling role, and the oil plays a role in lubricating a cutting area and prolonging the service life of the cutter.

The minimal quantity lubrication technology is used as a green quasi-dry processing technology and has the following advantages:

(1) as an effective green manufacturing technique, the MQL oil does not need to be replaced during processing, and only a small amount of pollution-free lubrication sleeve needs to be added into compressed gas periodically. And no waste liquid is discharged in the whole operation process. The produced oil mist can be directly discharged after being purified by equipment, thereby effectively avoiding the pollution of industrial production to the environment.

(2) The cutting condition of the cutter is improved, the cutting heat generated in the machining process is inhibited and reduced, and the service life of the cutter is prolonged. The cutting fluid is supplied by high-speed fog particles, so that the permeability of the lubricant is increased, the cooling and lubricating effects are improved, and the surface processing quality of the workpiece is improved.

(3) The MQL technology is implemented, the consumption of the lubricating medium is extremely low, and the tip consumption per hour is only 0.05-0.1L in general. In contrast, the consumption of the emulsion per hour in the conventional wet machining is about 1000L, and the actual consumption of the cutting fluid in the conventional wet machining is only one ten thousandth of that in the conventional wet machining, so that the cost of the cooling fluid is greatly reduced.

The minimal quantity lubrication supply system can be roughly classified into a single passage type and a double passage type. The difference between the two is that the air and the lubricating oil are mixed to form aerosol at different positions, namely, the aerosol is divided into two forms according to the difference of transmission and atomization of the micro-cutting fluid. Wherein the single-pass type is characterized in that air and lubricating oil are mixed into aerosol in the generating device, and then the aerosol is conveyed to a processing area through a track inside the spray head. The double-channel mode is characterized in that: the air and the lubricating oil are conveyed in different tracks into a mixing chamber near the processing spindle head, an aerosol is formed, and then the aerosol is conveyed to a processing area. Compared with a two-channel system, a single-channel system is easier to manufacture, but the oil mist is easy to disperse when conveying the cooling lubricating oil mist, particularly in a rotating spindle with strong centrifugal action, which often causes the oil mist distribution in a processing area to be uneven, thereby affecting the processing quality. And the distance that the two-channel formula trace lubrication system is carried to the processing region is nearer because after aerosol forms, and its lubricated liquid drop is more tiny than the single channel formula, and lubricated effect will be better, so the range of application is more extensive. The micro-lubricating technology has higher utilization rate of the cutting fluid and less environmental pollution. However, the method is the same as a pouring method, and the problem of insufficient cooling and lubrication of a machining area still exists under the working conditions of machining and milling holes and grooves with large depth and the like. The researchers have made great progress on the improvement of the cooling and lubricating mode of inner cooling and outer cooling, but still have many defects in application.

Although the prior device makes outstanding contributions in the aspects of resource saving, lubricating performance and the like, when a workpiece with a hole with larger depth and a groove with smaller depth is simultaneously processed on a machine tool, the problem of insufficient cooling and lubricating still exists in external cooling. The use of internal cooling machines still presents the problem of being uneconomical. Researchers think that by changing the structure of the tool shank of the tool, the original external cooling lubrication mode mechanism is kept unchanged, and meanwhile, external cooling can be converted into internal cooling. When the actual processing working condition needs an internal cooling lubrication mode, the external cooling can be converted into the internal cooling through the conversion tool holder, and the machine tool is enabled to have the internal cooling lubrication mode under the condition that the external cooling is kept. So as to meet the requirements of actual processing working conditions. Researchers have now conducted this research with significant success.

At present, although the cooling and lubricating mode of external cooling is converted into the cooling and lubricating mode of internal cooling, the machine tool has the cooling and lubricating mode of internal cooling and the cooling and lubricating mode of external cooling, and the conversion of external cooling and internal cooling can be realized through a special structure. The cooling and lubricating requirements of processing the workpieces such as holes and grooves with large depth and processing the workpieces such as holes or processing planes with small depth are met. However, during the actual machining of the machine tool, the operator needs to determine what cooling and lubricating manner is needed for the machining condition at this time according to his own experience, so as to switch between the cooling and lubricating manners of internal cooling and external cooling, which has great limitation. Furthermore, the switching between the cooling and lubrication modes of the internal cooling and the external cooling of the invention needs manual work, and intelligent switching between the internal cooling and the external cooling cannot be realized. Wasting larger human resources.

SUMMERY OF THE UTILITY MODEL

The purpose of this application is to the defect that prior art exists, provide a mill trace lubrication system, through milling the data acquisition of degree of depth to the lathe, will mill the data transmission of degree of depth to control center and carry out the analysis and processing of data, and can compare according to the internal cooling external cooling switching threshold that the initial setting was good, obtain optimum cooling lubrication mode under the lathe processing operating mode this moment, control center controls internal cooling external cooling system according to the result that obtains, realize the intelligence of internal cooling external cooling lubrication mode and switch over.

In order to realize the purpose, the following technical scheme is adopted:

the utility model provides a mill trace lubricating system, includes outer cold system and interior cold system, inserts the cutting fluid supply source through the switching-over device jointly, and outer cold system includes shower nozzle device, flexible arm module and shower nozzle angle module, the shower nozzle device passes through shower nozzle angle module and installs on flexible arm module, and the shower nozzle device can change the relative position with the work piece through flexible arm module and change shower nozzle device output end orientation through shower nozzle angle module, and the shower nozzle device intercommunication air supply for obtain gaseous and mix the cutting fluid back output that obtains from the cutting fluid supply source from the air supply.

Further, the inner cooling system comprises an inner cooling pipeline which is used for being arranged in the machine tool spindle and is communicated with the cutting fluid supply source through the reversing device.

Furthermore, the reversing device comprises a reversing base, a reversing channel is arranged in the reversing base, an inlet of the reversing channel is in butt joint with a cutting fluid supply source through a pipeline, a first outlet of the reversing channel is communicated with an inner cooling system, a second outlet of the reversing channel is communicated with an outer cooling system, a reversing block is installed in the reversing channel, and the reversing block can block the first outlet and/or the second outlet through rotation.

Further, the reversing base is provided with a pressure regulating structure and a pressure relief structure, and the pressure regulating structure and the pressure relief structure are communicated with the reversing channel.

Further, the pressure regulating structure comprises a pressure regulating valve core, a pressure regulating spring and a pressure regulating nut, the pressure regulating valve core and the pressure regulating spring are both installed in a pressure regulating channel preset in the reversing base, the pressure regulating channel is communicated with the reversing channel, and the pressure regulating nut is matched with the pressure regulating valve core and used for changing the plugging area of the pressure regulating valve core on the reversing channel.

Furthermore, the telescopic arm module is a three-axis mechanical arm, the output tail end of the telescopic arm module is connected with the spray head angle module, and the other end of the telescopic arm module is fixed on the machine tool.

Furthermore, the telescopic arm module comprises a telescopic arm support, an X-axis actuating arm, a Y-axis actuating arm and a Z-axis actuating arm, the X-axis actuating arm is installed on the telescopic arm support through the Z-axis actuating arm, the Y-axis actuating arm is installed on the telescopic arm support, and the spray head angle module is installed at the output end of the Y-axis actuating arm through magnetic force.

Further, the nozzle device comprises a gas pipe, a liquid pipe and a gas-liquid pipe, one end of the gas pipe is communicated with a gas source, the other end of the gas pipe is communicated with the gas-liquid pipe, the axis of the gas-liquid pipe is a set included angle with the axis of the gas-liquid pipe, one end of the liquid pipe is communicated with a cutting liquid supply source through a reversing device, the other end of the liquid pipe is in coaxial butt joint with the gas-liquid pipe, a gas-liquid mixing cavity is formed inside the gas-liquid pipe.

Further, the one end that the liquid pipe was kept away from to the gas-liquid pipe is equipped with the baffle, and the baffle center is equipped with the through-hole as the spout, and the gas-liquid mixing chamber passes through the through-hole output.

Furthermore, the nozzle angle module comprises a first rotating module and a second rotating module, the nozzle device is installed at the output end of the second rotating module, and the second rotating module is installed at the output end of the first rotating module and used for changing the orientation of the output end of the nozzle device, so that liquid drops sprayed by the nozzle device can spread into a liquid film along the surface of the heat source after impacting the surface of the heat source.

Compared with the prior art, the application has the advantages and positive effects that:

(1) the milling depth data of the machine tool is acquired, the milling depth data are transmitted to a control center for data analysis and processing, the most suitable cooling and lubricating mode under the machining working condition of the machine tool is obtained by comparing the milling depth data with the internal cooling and external cooling switching threshold value which is set at the beginning, and the control center controls an internal cooling and external cooling system according to the obtained result to realize the intelligent switching of the internal cooling and external cooling and lubricating modes;

(2) the lubricating mode control center can send corresponding lubricating mode signals to the motor control center according to the optimum cooling and lubricating mode under the milling working condition, and the motor control center controls the angular rotation of a stepping motor in the reversing device by controlling the number of pulse signals so as to realize intelligent switching of internal cooling and external cooling;

(3) the pretightening force of the pressure regulating spring 1 is regulated by regulating the pressure regulating handle 1, so that the cutting fluid pressure of a pressure reducing port, namely the pressure of the inner cooling channel and the outer cooling channel can be regulated; the pressure of the cutting fluid at this time, namely, the overflow pressure, is adjusted by adjusting the pretightening force of the pressure adjusting spring 2. By adjusting the relief pressure, the relief pressure can be made less than the maximum pressure that the reversing device can withstand. The system can be protected;

(4) in a nozzle gas-liquid pipeline of an external cooling mechanism of the system, more detailed mechanical analysis is carried out on the atomization of liquid drops in the selected nozzle gas-liquid pipeline, the effective liquid drop proportion when the atomized liquid drops reach the surface of a workpiece is calculated and analyzed, and the most appropriate nozzle structure is selected;

(5) the telescopic arm module of the external cooling mechanism of the system can realize position movement in X, Y, Z three directions, and the spray head angle module can realize angle rotation around the Y axis and the Z axis; the internal cooling and the external cooling are intelligently switched, the manual switching of the internal cooling and the external cooling in the working process of the machine tool by workers is not needed, and the labor force is greatly saved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application.

FIG. 1 is a distribution diagram of a micro-lubricating intelligent spray head system on an internal-cooling external-cooling milling machine tool in embodiments 1 and 2;

FIG. 2 is a general configuration diagram of a visual system according to embodiments 1 and 2;

FIG. 3 is a schematic diagram of intelligent switching between internal cooling and external cooling in examples 1 and 2;

FIG. 4 is an exploded view of the reversing device according to embodiments 1 and 2;

FIG. 5(a) is a front view of the reversing device in embodiments 1 and 2; FIG. 5(b) is a side view of a direction changing device according to embodiments 1 and 2; FIG. 5(c) is a top view of the reversing device in examples 1 and 2;

FIG. 6 is an internal assembly view of the reversing device according to embodiments 1 and 2;

fig. 7(a) is a front view of a commutation block in embodiments 1 and 2; FIG. 7(b) is a side view of a commutation block in embodiments 1 and 2; FIG. 7(c) is a top view of a commutation block in embodiments 1 and 2;

FIG. 8 is a bottom view of an upper base of the reverser in accordance with embodiments 1 and 2;

FIG. 9 is a plan view of a lower base of the reversing device in embodiments 1 and 2;

FIG. 10 is a bottom view of an upper base of the reverser in accordance with embodiments 1 and 2;

fig. 11 is an overall configuration diagram of the external cooling apparatus in embodiments 1 and 2;

fig. 12 is a structural view of a telescopic arm module in embodiments 1 and 2;

FIG. 13 is an exploded view of the telescopic arm according to embodiments 1 and 2;

FIG. 14 is an exploded view of the nozzle angle module of examples 1 and 2;

FIG. 15 is an assembly view of the head holder according to examples 1 and 2;

FIG. 16 is an assembly view of the left base of the first base of the head according to embodiments 1 and 2;

fig. 17(a) is a front view of a head angle module in examples 1 and 2:

FIG. 17(b) is a left side view of a nozzle angle block in examples 1 and 2

FIG. 17(c) is a plan view of a nozzle angle block in examples 1 and 2

FIG. 18 is an assembly view of the head unit according to examples 1 and 2;

FIG. 19 is a block diagram of information transmission of the micro-lubrication intelligent nozzle system according to embodiments 1 and 2;

fig. 20(a) shows the working state of the reversing device when the reversing block rotates 0 ° or 360 ° in embodiments 1 and 2;

fig. 20(b) shows the working state of the reversing device when the reversing block rotates 90 ° in embodiments 1 and 2;

fig. 20(c) shows the working state of the commutation device when the commutation block rotates 180 ° in embodiments 1 and 2;

fig. 20(d) shows the working state of the reversing device when the reversing block rotates 270 ° in embodiments 1 and 2;

FIG. 21(a) is a schematic view showing the operation of the reversing device in examples 1 and 2 before decompression;

FIG. 21(b) is a schematic view showing the operation of decompressing the reverser in examples 1 and 2;

FIG. 21(c) is a schematic diagram showing the operation of the reversing device in the embodiment 1 or 2 for overflow;

FIG. 22(a) shows a first embodiment of a gas-liquid line of the showerhead of examples 1 and 2;

FIG. 22(b) shows a second embodiment of the gas-liquid line of the head in examples 1 and 2;

FIG. 22(c) shows a third embodiment of the gas-liquid line of the head in examples 1 and 2;

FIG. 23 is a flow chart of the crushing and atomizing of the gas-liquid pipeline of the nozzle in examples 1 and 2;

FIG. 24 is a graph showing the force applied to the cutting fluid droplets in examples 1 and 2;

FIG. 25 is a sectional view taken through Bernoulli's equation of a gas-liquid pipeline of the sprinkler in embodiments 1 and 2;

FIG. 26(a) is a graph showing force analysis of the cutting fluid droplets in examples 1 and 2;

FIG. 26(b) is a graph showing the analysis of the direction of the viscous force exerted on the cutting fluid in examples 1 and 2;

FIG. 27 is a view showing the positional relationship between a nozzle and a workpiece in examples 1 and 2;

FIG. 28 is a probability density distribution diagram of spray droplets in examples 1 and 2.

In the figure, a vision system I, an internal cooling system II, an external cooling system III, an external cooling cutting night storage device II-1 and a reversing device II-2; and an external cold compressed air storage device III-1.

The I-1 vision system comprises a camera, an I-2 lighting device, an I-3 self-stabilizing pan-tilt, an I-4 image acquisition control center, an I-5 image acquisition control center wireless transmission device, an I-6 lubrication mode control center, an I-7 lubrication mode control center wireless transmission device, an I-8 motor control center, an I-9 motor control center wireless transmission device, an I-10 support and an I-11 vision system bolt.

An upper seat of an II-2-1 reversing device, a lower seat of an II-2-2 reversing device, an II-2-3 reversing block, an II-2-4 adjusting sleeve 1, an II-2-5 adjusting sleeve 2, an II-2-6 pressure regulating nut 1, an II-2-7 pressure regulating nut 2, an II-2-8 adjusting screw 1, an II-2-9 adjusting screw 2, an II-2-10 spring seat 1, an II-2-11 spring seat 2, an II-2-12 pressure regulating spring 1, an II-2-13 pressure regulating spring 2, an II-2-14 spring seat 1, an II-2-15 spring seat 2, an II-2-16 valve core 1, an II-2-17 valve core 2, an II-2-18 reversing motor, The bearing of the II-2-3-1 reversing block, the bolt gasket of the II-2-2-1 reversing device, the bolt of the II-2-2-2 reversing device, the bolt gasket of the II-2-18-1 directional motor, the bolt of the II-2-18-2 reversing motor and the coupler of the II-2-18-3 reversing motor.

II-2-2-3 reversing device bolt holes, an A inner cooling device pipeline, B outer cooling device pipeline, II-2-18-4 reversing motor bolt holes, a III-2-1X, Y, Z telescopic arm module, a III-2-2 spray head angle module, a III-2-1-1X direction telescopic arm, a III-2-1-2Y direction telescopic arm, a III-2-1-3Z direction telescopic arm, a III-2-1-4X and Z direction telescopic arm connector, a III-2-1-5Z and Y direction telescopic arm connector, a III-2-1-6X direction telescopic arm motor, a III-2-1-7Y direction telescopic arm motor, a III-2-1-8Z direction telescopic arm motor,

III-2-1-1-1 telescopic arm wall support, III-2-1-1-2 telescopic arm end cover, III-2-1-1-3 movable sliding block, III-2-1-4 screw rod, III-2-1-5 bolt, III-2-1-1-6 coupler, III-2-1-7 coupler bolt, III-2-1-1-8 screw rod, III-2-1-9 support gasket, III-2-1-1-10 support bolt, III-2-1-1-3 movable sliding block, III-2-1-4 screw rod, III-2-1-5 bolt, III-2-1-1-6 movable sliding block, III-,

III-2-2-1 spray head first base right base, III-2-2-2 spray head first base left base, III-2-2-3 spray head second base right base, III-2-2-4 spray head second base left base, III-2-2-5 spray head bracket, III-2-2-6 spray head device, III-2-2-7 first base motor, III-2-2-8 second base motor, III-2-2-9 spray head first base bolt, III-2-2-10 spray head second base bolt, III-2-2-11 first base bearing, III-2-2-12 bracket bearing, III-2-2-13 first base bolt, III-2-2-14 second base bolt, III-2-2-15 first base coupler, III-2-2-16 second base coupler, III-2-2-6-1 spray head shell and III-2-2-6-2 spray head gas-liquid pipeline.

1 cutting fluid storage tank, 2 hydraulic pumps, 3 pressure regulating valves, 4 throttling valves, 5 overflow valves, 6 cutting fluid recovery tanks, 7 air compressors, 8 filters, 9 air storage tanks, 10 pressure gauges, 11 pressure regulating valves, 12 throttling valves, 13 overflow valves and 14 compressed air recovery tanks.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an", and/or "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof;

for convenience of description, the words "up", "down", "left" and "right" in this application, if any, merely indicate that the directions of movement are consistent with those of the figures themselves, and are not limiting in structure, but merely facilitate the description of the invention and simplify the description, rather than indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting in this application.

As described in the background art, in the prior art, the switching between the cooling and lubricating modes of the internal cooling and the external cooling needs to be performed manually, and the intelligent switching between the internal cooling and the external cooling cannot be realized; in view of the above, the present application provides a milling minimal quantity lubrication system.

Example 1

In an exemplary embodiment of the present application, a milling minimal quantity lubrication system is presented, as shown in fig. 1-28.

The distribution of the system on the machine tool is shown in figure 1, and the system comprises a vision system I and an external cooling system III.

The vision system I is used for monitoring the milling state of a machine tool cutter in real time, acquiring a real-time milling depth image of a workpiece milled by the cutter, and transmitting the acquired real-time milling depth image of the workpiece milled by the cutter to the control system through the wireless transmission device;

the overall structure of the vision system is shown in fig. 2, and the vision system comprises a camera I-1, a lighting device I-2, a self-stabilizing pan-tilt I-3, an image acquisition control center I-4 and an image acquisition control center wireless transmission device I-5. And a lubricating mode control center I-6, a lubricating mode control center wireless transmission device I-7, a motor control center I-8, a motor control center wireless transmission device I-9 and a support I-10 are also arranged on the self-stabilizing pan-tilt I-4. The self-stabilizing holder I-3 is connected through a vision system bolt I-11 and is arranged on a left base III-2-2-4 of the second base of the spray head; the camera I-1 and the image acquisition control center I-4 are arranged, the lighting device I-2 is arranged above the camera I-1, and the image acquisition control center wireless transmission device I-5 is arranged on the image acquisition control center I-4.

The camera I-1 is used for shooting a real-time image of a workpiece milled by the cutter, and aims to acquire milling depth information of the cutter. The lighting device I-2 is used for lighting the working condition, so that the picture taken by the camera I-1 is clearer, and the picture taking under the dark working condition can be met. The self-stabilizing pan-tilt I-3 can automatically adjust the absolute horizontal attitude of the camera I-1, and can realize the high stability of the camera I-1 under a proper swing amplitude. The camera I-1 is kept in a relatively stable state with the target object at all times, so that the stability of the shot image is ensured. On one hand, the image acquisition control center I-4 receives a shooting starting instruction sent by the lubrication mode control center I-6 through the image acquisition control center wireless transmission device I-5, and controls the camera I-1 to shoot images; on the other hand, the device is used for storing the image information shot by the camera I-1 and transmitting the image information to the lubricating mode control center I-6 through the image acquisition control center wireless transmission device I-5 in a wireless mode.

The lubricating mode control center I-6 is installed on the self-stabilizing holder I-3, receives the real-time image of the workpiece milled by the cutter through the lubricating mode control center wireless transmission device I-7, and obtains the real-time milling depth data of the cutter through analyzing and processing the real-time image of the workpiece milled by the cutter through the lubricating mode control center I-6. And a milling depth threshold value for converting an internal cooling and external cooling lubrication mode is arranged in the lubrication mode control center I-6. The lubricating mode control center I-6 compares the obtained real-time milling depth data of the cutter with a set milling depth threshold value, obtains the lubricating mode under the machining working condition according to the comparison result, and transmits the result to the motor control center I-8 in the form of analog signal quantity through the lubricating mode control center wireless transmission device I-7.

The motor control center I-8 is arranged on the self-stabilizing pan head I-3, receives an analog signal quantity which contains a lubricating mode required under the milling working condition and is sent by the lubricating mode control center I-6 through the motor control center wireless transmission device I-9, analyzes and processes the analog signal quantity, controls the angle of a reversing motor II-2-18 in the reversing device in a mode of controlling the quantity of pulse signals through the motor control center wireless transmission device I-9, controls the angle of a reversing block II-2-3 in the reversing device II-2 through the reversing motor II-2-18, further realizes the switching of the cutting fluid to an inner cooling device pipeline A or an outer cooling device pipeline B, and realizes the switching of an inner cooling system and an outer cooling system, therefore, the most suitable lubrication mode conversion under the working condition of milling the workpiece by the machine tool at the moment is realized.

And the inner cooling system II and the outer cooling system III are used for executing a mechanism for switching between inner cooling and outer cooling sent by the control system. The inner cooling system comprises an inner cooling outer cooling cutting night storage device II-1, a reversing device II-2 and an inner cooling device II-3. The external cooling system comprises an internal cooling external cooling cutting night storage device II-1, an external cooling compressed air storage device III-1, a reversing device II-2 and an external cooling device III-2.

The internal cooling and external cooling cutting fluid storage device II-1 is used for conveying cutting fluid to the internal cooling device II-3 and the external cooling device III-2 through the reversing device II-2, and the external cooling compressed air storage device III-1 is used for conveying compressed gas to the external cooling device III-2 through a pipeline. As shown in fig. 3, the internal-cooling external-cooling cutting fluid storage device II-1 includes a cutting fluid storage tank 1, a hydraulic pump 2, a pressure regulating valve 3, a throttle valve 4, an overflow valve 5, and a cutting fluid recovery tank 6. The external cooling compressed air storage device III-1 comprises an air compressor 7, a filter 8, an air storage tank 9, a pressure gauge 10, a pressure regulating valve 11, a throttle valve 12, an overflow valve 13 and a compressed air recovery tank 14.

The explosion diagram of the reversing device II-2 is shown in figure 4. The reversing device II-2 is a device used for realizing an internal cooling and external cooling switching command sent by a control system in an internal cooling and external cooling system, and transmits cutting fluid to the reversing device II-2 from the internal cooling and external cooling cutting night storage device II-1 through a pipeline. A three-dimensional view of the reversing device II-2 is shown in fig. 5. The device comprises an upper seat II-2-1 of a reversing device, a lower seat II-2-2 of the reversing device, a reversing block II-2-3, an adjusting sleeve 1II-2-4, an adjusting sleeve 2II-2-5, a pressure regulating nut 1II-2-6, a pressure regulating nut 2II-2-7, an adjusting screw 1II-2-8 and an adjusting screw 2II-2-9, the spring seat comprises a spring seat 1II-2-10, a spring seat 2II-2-11, a pressure regulating spring 1II-2-12, a pressure regulating spring 2II-2-13, a spring base 1II-2-14, a spring base 2II-2-15, a valve core 1II-2-16, a valve core 2II-2-17 and a reversing motor II-2-18.

The internal assembly of the reversing device II-2 is shown in figure 6, the three views of the reversing block II-2-3 are shown in figure 7, the bottom view of the upper seat II-2-1 of the reversing device is shown in figure 8, and the top and bottom views of the lower seat II-2-2 of the reversing device are shown in figures 9 and 10. The reversing block II-2-3 is arranged in the upper seat II-2-1 and the lower seat II-2-2 of the reversing device through a reversing block bearing II-2-3-1. The reversing device upper seat II-2-1 and the reversing device lower seat II-2-2 are connected together through a reversing device bolt gasket II-2-2-1, a reversing device bolt II-2-2-2 and a reversing device bolt hole II-2-2-3; the adjusting sleeve 1II-2-4 and the adjusting sleeve 2II-2-5 are provided with threads and are connected and installed on the upper seat II-2-1 of the reversing device through the threads; the pressure regulating nut 1II-2-6 and the pressure regulating nut 2II-2-7 are respectively arranged on the regulating sleeve 1II-2-4 and the regulating sleeve 2 II-2-5; an adjusting screw 1II-2-8, a spring seat 1II-2-10 and a pressure regulating spring 1II-2-12 are sequentially arranged in an adjusting sleeve 1II-2-4, the tail end of the pressure regulating spring 1II-2-12 is arranged on a spring base 1II-2-14 and is connected with a valve core 1 II-2-16; an adjusting screw 2II-2-9, a spring seat 2II-2-11 and a pressure regulating spring 2II-2-13 are sequentially arranged in an adjusting sleeve 2II-2-5, and the tail end of the pressure regulating spring 2II-2-13 is arranged on a spring base 2II-2-15 and is connected with a valve core 2 II-2-17.

The cutting fluid pressure reducing device is formed in a cavity of an upper seat II-2-1 of the reversing device by an adjusting sleeve 1II-2-4, a pressure adjusting nut 1II-2-6, an adjusting screw 1II-2-8, a spring seat 1II-2-10, a pressure adjusting spring 1II-2-12, a spring base 1II-2-14 and a valve core 1II-2-16, and the pressure of the cutting fluid in the cavity is adjusted by adjusting the pretightening force of the adjusting screw 1 II-2-8; the adjusting sleeve 2II-2-5, the pressure adjusting nut 2II-2-7, the adjusting screw 2II-2-9, the spring seat 2II-2-11, the pressure adjusting spring 2II-2-13, the spring base 2II-2-15 and the valve core 2II-2-17 form a cutting fluid overflow device in the reversing device upper seat II-2-2, and the maximum pressure of the cutting fluid in the cavity is controlled by the pretightening force of the adjusting screw 2II-2-9, so that the reversing device is protected.

The reversing motor II-2-18 is a stepping motor and is arranged on the outer side of the lower seat of the reversing device through a reversing motor bolt gasket II-2-18-1, a reversing motor bolt II-2-18-2 and a reversing motor bolt hole II-2-18-3. The reversing motor II-2-18 is connected with one end of the reversing block II-2-3 through a reversing motor coupler II-2-18-3. The reversing motors II-2-18 are used as actuating mechanisms of the motor control center I-8 and rotate angularly by receiving the number of pulse signals. The reversing motor II-2-18 provides power for the reversing block II-2-3 to drive the reversing block II-2-3 to rotate in the reversing device II-2, and switching between the internal cooling device pipeline A and the external cooling device pipeline B by the reversing block II-2-3 is realized.

The overall structure of the external cooling device III-2 is shown in FIG. 11. The external cooling device III-2 is used for conveying the cutting fluid to the spray head device III-2-2-6 through a pipeline, and spraying the cutting fluid to cool the cutter and the processing workpiece through a nozzle. The external cooling device comprises X, Y, Z telescopic arm module III-2-1 and spray head angle module III-2-2.

The structure of the telescopic arm module III-2-1 is shown in fig. 12. The telescopic arm module III-2-1 comprises an X-direction telescopic arm III-2-1-1, a Y-direction telescopic arm III-2-1-2, a Z-direction telescopic arm III-2-1-3, an X-direction and Z-direction telescopic arm connector III-2-1-4, a Z-direction and Y-direction telescopic arm connector III-2-1-5, an X-direction telescopic arm motor III-2-1-6, a Y-direction telescopic arm motor III-2-1-7 and a Z-direction telescopic arm motor III-2-1-8.

An explosive diagram of the telescopic arm III-2-1-1 is shown in figure 13, and the X-direction telescopic arm, the Y-direction telescopic arm and the Z-direction telescopic arm comprise telescopic arm wall supports III-2-1-1-1, telescopic arm end covers III-2-1-1-2, movable sliding blocks III-2-1-1-3 and screw rods III-2-1-1-4. The X-direction telescopic arm motor III-2-1-6, the Y-direction telescopic arm motor III-2-1-7 and the Z-direction telescopic arm motor III-2-1-8 are step motors and are connected and installed on the outer side of a telescopic arm end cover III-2-1-1-2 through bolts III-2-1-5, the step motors are connected with one end of a screw rod III-2-1-4 through a step motor coupler III-2-1-6, the other end of the screw rod III-2-1-4 is installed on a telescopic arm support III-2-1-1 through a telescopic arm bearing III-2-1-1-8, and the step motors provide power for the screw rod III-2-1-1-4, thereby driving the movable sliding block III-2-1-1-3 to move on the telescopic arm bracket III-2-1-1-1 and controlling the movement of the spray head in X, Y, Z three directions. The telescopic arm wall support III-2-1-1-1 is fastened with a telescopic arm end cover III-2-1-1-2 through a support gasket III-2-1-1-9 and a support bolt III-2-1-1-10.

The exploded view of the nozzle angle module III-2-2 is shown in fig. 14. The nozzle angle module III-2-2 comprises a nozzle first base right base III-2-2-1, a nozzle first base left base III-2-2-2, a nozzle second base right base III-2-3, a nozzle second base left base III-2-4, a nozzle support III-2-2-5, a nozzle device III-2-2-6, a first base motor III-2-2-7 and a second base motor III-2-2-8.

An assembly view of the head holder III-2-2-5 is shown in FIG. 15, and an assembly view of the head first base, left base III-2-2, is shown in FIG. 16. The right base III-2-2-1 of the first base of the spray head and the left base III-2-2-2 of the first base of the spray head are connected together through a bolt III-2-2-9 of the first base of the spray head. The right base III-2-2-3 of the second base of the spray head and the left base III-2-2-4 of the second base of the spray head are connected together through a bolt III-2-2-10 of the second base of the spray head. The right base of the second base of the spray head is arranged on the first base of the spray head through a first base bearing III-2-2-11, and the spray head bracket is arranged on the second base of the spray head through a bracket bearing III-2-2-12.

The three views of the nozzle angle module III-2-2 are shown in FIG. 17, the first base motor III-2-2-7 and the second base motor III-2-2-8 are stepping motors, the first base bolt III-2-2-13 and the second base bolt III-2-2-14 are connected and respectively installed on the outer sides of the right base III-2-1 and the right base III-2-2-3 of the first base of the spray head and the second base of the spray head, the first base motor III-2-2-7 is connected with the spray head support through a first base coupler III-2-2-15, and the second base motor III-2-8 is connected with the left base III-2-2-2 of the first base of the spray head through a second base coupler III-2-2-16. The first base motor III-2-2-7 and the second base motor III-2-2-8 are used for controlling the rotating angle of the spray head.

An assembly view of the spray head device III-2-2-6 is shown in FIG. 18. The spray head device III-2-2-6 comprises a spray head shell III-2-2-6-1 and a spray head gas-liquid pipeline III-2-2-6-2. The spray head gas-liquid pipeline is arranged in the spray head shell and comprises a hollow pipe 3, a gas pipe 2 and a liquid pipe 1. The liquid pipe 1 is connected with the hollow pipe 3, the liquid pipe 1 is provided with an opening with a bulge, and one end of the air pipe 2 is inserted into the opening of the liquid pipe 1 in a bending way; the spray head outer shell III-2-2-6-1 is connected to the spray head support III-2-2-5 through threads.

The visual system is connected and installed on a left base III-2-2-4 of the second base of the spray head through a support through a visual system bolt I-11 and a bolt hole III-2-2-17, the left base III-2-2-4 of the second base of the spray head is connected through magnetic force, and the spray head angle module III-2-2 is installed on the telescopic arm module III-2-1.

The milling depth data of the machine tool is acquired, the milling depth data are transmitted to the control center for data analysis and processing, the most suitable cooling and lubricating mode under the machining working condition of the machine tool is obtained by comparing the milling depth data with the internal cooling and external cooling switching threshold value which is set at the beginning, and the control center controls the internal cooling and external cooling system according to the obtained result to realize the intelligent switching of the internal cooling and external cooling and lubricating modes.

Example 2

In another exemplary embodiment of the present application, as shown in fig. 1 to 28, a method for internal-cooling and external-cooling switched milling minimal quantity lubrication is provided, which uses the milling minimal quantity lubrication system described in example 1, and includes the following steps:

the method comprises the following steps:

the vision system acquires a real-time milling depth image of the workpiece and transmits the real-time milling depth image to the lubrication mode controller for processing;

setting a threshold value according to the milling depth of the lubrication mode controller, judging the lubrication mode of the working condition at the moment, and controlling the reversing device to act to enable the internal cooling system or the external cooling system to work;

the internal cooling system conveys the lubricating liquid to an internal cooling pipeline of the cutter, and cooling and lubrication are realized through circulating heat exchange;

the external cooling system sprays the mixed gas of the lubricating liquid to a workpiece machining position through the nozzle device to realize cooling and lubrication, and liquid drops output by the external cooling system impact the surface of a heat source and then spread into a liquid film along the surface of the heat source to exchange heat on the surface of the heat source.

Specifically, the detailed steps are described in conjunction with example 1:

the information transmission block diagram is shown in fig. 19. When the machining starts, the lubrication mode control center I-6 receives a machining instruction and controls the visual system I to work. And after the visual system I works, transmitting the acquired image of the workpiece milled by the cutter to a lubricating mode control center I-6. And analyzing and processing the image of the workpiece milled by the tool to obtain real-time milling depth data of the tool. The milling depth threshold value converted by the internal cooling and external cooling lubrication mode is arranged in the lubrication mode control center I-6. The lubricating mode control center I-6 compares the obtained real-time milling depth data of the cutter with a set milling depth threshold value, obtains the lubricating mode under the machining working condition at the moment according to the comparison result, and transmits the result to the motor control center I-8 in the form of analog signal quantity. The motor control center I-8 is used for receiving the analog signal quantity which is sent by the lubricating mode control center I-6 and contains the lubricating mode required under the milling working condition at the moment, analyzing and processing the analog signal quantity, controlling the rotation of the reversing motor II-2-18 in a mode of different pulse signal quantities, and controlling the angular rotation of a reversing block II-2-3 in a reversing device II-2 in the internal cooling and external cooling system, so that the switching of the cutting fluid to the pipeline A of the internal cooling device or the pipeline B of the external cooling device is realized, and the switching of the internal cooling and external cooling system is completed. The cutting fluid flows out from the internal cooling and external cooling storage device II-1, and when the cutting fluid flows through the reversing device II-2, the cutting fluid flows to the internal cooling device II-3 or the external cooling device II-2 according to the opening and closing state of the pipeline A of the internal cooling device or the pipeline B of the external cooling device in the reversing device II-2 which is adjusted under the actual processing working condition. The most suitable lubrication mode conversion under the working condition of milling the workpiece by the machine tool at the moment is realized.

The switching of the internal cooling and external cooling lubricating system is realized by the rotation angle of a reversing block II-2-3 in a reversing device II-2. The angle adjustment of the reversing block II-2-3 is realized by receiving the number of pulse signals of a motor control center I-8 by a driver of a reversing motor II-2-18 to perform angle rotation of the reversing motor II-2-18, so that the angle rotation of the reversing block II-2-3 is controlled, and the switching of internal cooling and external cooling of a lubricating system is realized.

Each stepper motor has its fixed step angle θ, which is the mechanical angle the stepper motor rotates through to receive a pulse signal without a reduction gear. The specific algorithm is as follows:

wherein n is_cNumber of rotor teeth of step motor, n_cThe running beat number of the stepping motor.

The number N of pulse signals required when the stepping motor rotates for one circle_306°The algorithm is as follows:

the number N of pulse signals required when the stepping motor rotates at any angle_rThe algorithm is as follows:

wherein, theta_rThe stepping motor is rotated by any angle.

The above equation can be converted into: theta_r＝N_r×θ

Thus, the pulse signal number N given to the step motor driver of the reversing motor of the reversing device II-2 by the motor control center I-8 can be adjusted according to the formula_rThe rotating angle of a reversing block II-2-3 in the reversing device II-2 is adjusted to realize the switching of an internal cooling and external cooling lubricating system.

According to the shape of the reversing block designed in the embodiment, the reversing device II-2 has four working states as shown in FIG. 20:

(1) as shown in fig. 20(a), at this time, the working state of the reversing device II-2 is that neither the internal cooling channel a nor the external cooling channel a is open, and the rotation angle of the reversing block II-2-3 may be 0 ° or 360 ° when the internal cooling and external cooling lubrication system is in the stop working state; when the angle of the reversing block II-2-3 is 0 degree, namely the reversing motor II-2-18 does not rotate, the motor control center I-8 does not give pulse signals to the stepping motor driver. When the angle of the reversing block is 360 degrees, namely the reversing motor II-2-18 rotates for a circle, the number of pulse signals given to the stepping motor driver by the motor control center I-8 is as follows:

(2) as shown in fig. 20(B), the operation state of the reversing device II-2 is that the internal cooling passage a is opened, the external cooling passage B is closed, and the internal cooling and external cooling lubrication system is switched to the internal cooling operation state. The rotation angle of the reversing block II-2-3 is 90 degrees, namely the reversing motor II-2-18 rotates 90 degrees, and the number of pulse signals given by the motor control center I-8 to the stepping motor driver is as follows:

(3) as shown in FIG. 20(c), the operation state of the reversing device II-2 is the inner cooling passageAnd the A and the external cold channel B are not communicated, and the internal cold and external cold lubrication system is switched to a stop working state. The rotation angle of the commutation block II-2-3 is 180 degrees. When the angle of the reversing block II-2-3 is 180 degrees, namely the reversing motor II-2-18 rotates 180 degrees, the number of pulse signals given by the motor control center I-8 to the stepping motor driver is as follows:

(4) as shown in fig. 20(d), the operation state of the reversing device II-2 is that the external cooling passage B is opened, the internal cooling passage a is closed, and the internal cooling and external cooling lubrication system is switched to the external cooling operation state. The rotation angle of the reversing block II-2-3 is 270 degrees, namely the reversing motor II-2-18 rotates 270 degrees, and at the moment, the number of pulse signals given by the motor control center I-8 to the stepping motor driver is as follows:

n is equal to 0 DEG and N_180°Or N_360°When the oil is in a static state, the internal and external cold lubrication systems are in a static state, and N is equal to N_90°When the system is in the inner cooling working state, N is equal to N_270°When the internal-cooling and external-cooling lubricating system is in an external-cooling working state, the motor control center can be controlled to respectively give pulse signal quantity to the reversing device stepping motor driver: 0 degree and (N)_180°Or N_360°)、N_90°、N_270°The free switching of the inner cooling and the outer cooling is realized.

The operation principle of the reversing device II-2 of the present embodiment is shown in FIG. 21, and when the inner cooling pipe A or the outer cooling pipe B is opened, the pressure is p as shown in FIG. 21(a)₁The cutting fluid enters the decompression working cavity of the reversing device II-2 from the fluid inlet P and enters the output hydraulic branch after passing through the decompression port. Since a pressure loss occurs when the cutting fluid passes through the gap of the pressure reducing port, the cutting fluid pressure p passing through the pressure reducing port₂Cutting fluid pressure p lower than the fluid inlet₁. After the cutting fluid passes through the pressure reducing port, a part of the cutting fluid flows into the lower cavity of the valve core 1II-2-16 through the side through hole, and an upward thrust p is generated₂A₁Wherein A is₁Is the effective working area of the left end of the valve core 1 II-2-16. When the cutting fluid acts on the bottom end of the valve core 1II-2-16, the rightward thrust generated is smaller than the pretightening force F of the pressure regulating spring 1II-2-12_s1When the valve core 1II-2-16 is at the leftmost position, the pressure reducing port is fully opened and does not play a role of reducing pressure, and at the moment, p is₁≈p₂。

Further, the pressure p is obtained after passing through the pressure reducing port₂The cutting fluid flows leftwards and flows to the lower end of the valve core 2II-2-17 through the valve core 2II-2-17 and the damping hole 2 to generate an upward thrust p₂A₂Wherein A is₂The effective working area of the lower end of the valve core 2II-2-17 and the pretightening force of the pressure regulating spring 2II-2-13 at the upper end of the valve core 2II-2-17 are F_s2. When pressure p of the cutting fluid₂Generated axial thrust p₂A₂Less than spring pre-tightening force F_s2The dead weight G of the valve core 2II-2-17 and the friction force F between the valve core 2II-2-17 and the inner cavity of the reversing device_fWhen the overflow device is in operation, the left outlet is closed.

When the inner cooling pipeline A or the outer cooling pipeline B is opened, the cutting fluid pressure p passing through the pressure reducing port₂The pretightening force F is larger than that of the pressure regulating spring 1II-2-12_s1When, namely: p is a radical of₂≥F_s1When the pressure reducing valve is used, the valve core 1II-2-16 overcomes the pre-tightening force of the pressure regulating spring 1II-2-12 to move towards the right side under the action of the cutting hydraulic pressure of the left side cavity, so that the pressure reducing port is reduced, as shown in fig. 21 (b). At this time, the pressure loss generated when the cutting fluid passes through the pressure reducing port makes the cutting fluid pressure p passing through the pressure reducing port₂The counter force range of the pressure regulating spring 1II-2-12 is reduced and stabilized.

According to the balance relation between the outlet pressure and the pressure regulating spring 1 II-2-12: p is a radical of₂A₁＝k₁(x₀₁+Δx)

The cutting fluid pressure p through the pressure relief opening can be determined₂Comprises the following steps:

wherein k is₁For adjusting the spring rate, x, of the spring 1II-2-12₀₁Is a pressure regulating spring 1II-2-12The precompression amount, Δ x, is the amount of change in displacement of the pressure-reducing port.

As can be seen from the above formula, the displacement variation quantity delta x of the pressure reducing port is far smaller than the precompression quantity x of the pressure regulating spring 1II-2-12₀₁The cutting fluid pressure p passing through the pressure reducing port₂Can remain substantially stable. The pretightening force F of the pressure regulating spring 1II-2-12 can be adjusted by adjusting the pressure regulating nut 1II-2-6_s1The cutting fluid pressure p of the pressure reducing port can be adjusted₂。

At this time, the pressure p of the cutting fluid₂Generated axial thrust p₂A₂Less than spring pre-tightening force F_s2The dead weight G of the valve core 2II-2-17 and the friction force F between the valve core 2II-2-17 and the inner cavity of the reversing device_fAnd the left outlet is closed, and the overflow device does not work.

When the inner cooling line A and the outer cooling line B are closed as shown in FIG. 21(c), the pressure p of the cutting fluid passing through the pressure reducing port₂Will rise, and the following will occur in the cavity in which the valve core 2II-2-17 is located:

(1) pressure p of cutting fluid₂The thrust p of the cutting fluid acting on the bottom end of the valve core 2II-2-17 is raised₂A₂Increase to just overcome the pre-tightening force F of the spring_s2The dead weight G of the valve core 2II-2-17 and the friction force F between the valve core 2II-2-17 and the inner cavity of the reversing device_fWhen the cutting fluid is pushed by the cutting fluid, the valve core 2II-2-17 starts to move upwards, and according to the stress balance relation of the valve core 2 II-2-17: p is a radical of_kA₂＝F_s2+G

Critical opening pressure of valve port

Wherein k is₂For adjusting the spring rate, x, of the spring 2II-2-13₀₂The spring pre-tightening amount of the pressure regulating spring 2II-2-13 is adjusted.

(2) Pressure p of cutting fluid₂And when the valve core 2II-2-17 continues to rise, the valve core moves upwards, the valve port is opened, and the cutting fluid flows into the cutting fluid storage device through the left outlet, namely, the cutting fluid starts to overflow. When the valve core 2II-2-17 moves upwards and is in a certain balance position,the pressure regulating spring 2II-2-13 will be compressed a certain distance x, at which time the force balance equation of the spool 2II-2-17 becomes: p is a radical of₂A₂＝k₂(x₀₂+x)+G+F_f

I.e. the pressure p of the cutting fluid at this time₂Comprises the following steps:

as can be seen from the above formula, when the overflow occurs, the pressure p of the cutting fluid at that time₂The valve core is not influenced by flow change, and is influenced by the spring stiffness and the pretightening force of the pressure regulating spring 2II-2-13, the self weight of the valve core 2II-2-17 and the sliding friction force. Wherein the spring stiffness of the pressure regulating spring 2II-2-13, the self weight of the valve core 2II-2-17 and the sliding friction force are constant values after the reversing device is built, so the pretightening force F of the pressure regulating spring 2II-2-13 can be adjusted_s2To adjust the pressure p of the cutting fluid at this time₂I.e. the overflow pressure. By adjusting the relief pressure, the relief pressure can be made less than the maximum pressure that the reversing device can withstand. The reversing device can be protected.

The sprayer device comprises a sprayer shell and a sprayer gas-liquid pipeline. The spray head gas-liquid pipeline is arranged in the spray head shell and comprises a hollow pipe, a gas pipe and a liquid pipe. As shown in fig. 19. The external cooling supply adopts a micro-lubricating mode, the cutting fluid flowing out through an external cooling pipeline of the reversing device flows into a liquid pipe in a spray head gas-liquid pipeline in the spray head device through a pipeline, high-pressure gas flows into a gas pipe in the spray head gas-liquid pipeline through a pipeline, and finally the high-pressure gas in the gas pipe and the cutting fluid in the liquid pipe form mist liquid drops through the hollow pipe to be sprayed outwards. Under the condition of ensuring that the length of the air pipe is not changed, the position relation of the hollow pipe, the air pipe and the liquid pipe can be designed into three forms as shown in figure 22.

First, as shown in fig. 22(a), the end of the liquid tube is bent at 30 °, the end of the air tube is also bent at 30 °, and the end of the air tube is inserted into the end of the liquid tube and inserted into the left end of the hollow tube. According to the fact that the cutting fluid passes through the bending zone in the process of flowing to the hollow pipe in the fluid pipe, and when the cutting fluid passes through the bending zone, vortexes and air pockets are generated, strong impact and other phenomena occur, so that the friction resistance of the flowing fluid is increased, and local pressure loss is caused; in addition, the liquid has viscosity, and friction is generated between the liquid and the pipeline due to relative movement of the liquid and the pipeline caused by the viscosity, so that the liquid can cause pressure loss along the pipeline in the flowing process. Similarly, for gases, pressure losses are also caused when passing through the trachea.

(1) The on-way pressure loss of the cutting fluid in the fluid pipe can be divided into two parts, as shown in fig. 22(a), and one part is the pressure loss of the cutting fluid in the horizontal straight pipe before the cutting fluid is bent; some of them are pressure losses caused in the inclined pipe by the cutting fluid after the bending until the gas-liquid mixing point P. Calculating the on-way pressure loss of the two parts of the cutting fluid in the fluid pipe can be calculated by the following formula:

wherein, lambda is the on-way resistance coefficient, and the material of the liquid pipe of this embodiment selects metal to make, on-way resistance coefficient

l₁Length of horizontal straight pipe of liquid pipe before bending, v₁Flow rate of cutting fluid before bending₂The length of the inclined pipeline of the liquid pipe is before the gas-liquid mixing point P after bending, v₂The flow rate of the cutting fluid after bending, v₁≈v₂。d₁Is the diameter of the liquid pipe, p₁Is the cutting fluid density.

(2) When the cutting fluid passes through the bent portion in the fluid tube, the fluid movement resistance increases due to the bending, resulting in a pressure loss, as shown in fig. 22 (a). Calculating the local pressure loss of the cutting fluid at the bending part can be calculated by the following formula:

where ξ is the local drag coefficient. ξ is 0.13.

From the above analysis, it can be known that the total pressure loss of the cutting fluid in the nozzle gas-liquid pipeline is:

the gas may generate a certain heat exchange with the outside through the pipeline in the process of flowing in the gas pipe, and the gas is often treated as an isothermal process due to relatively uniform temperature. To simplify the calculations, flow resistance is often considered to be an incompressible fluid. The pressure loss per meter of tube length of the gas in the gas tube can be calculated by the following formula:

wherein q is_mIs the mass flow rate of the gas, lambda is the on-way drag coefficient, d₂Is the diameter of the trachea. Rho₂Is the gas density.

The total pressure loss is then:

the total loss of pressure caused for the gas-liquid lines of the showerhead of the type one shown is:

the second form: as shown in fig. 22(b), the end of the liquid tube is bent at 30 °, the air tube is a horizontal straight tube, and the end of the liquid tube is inserted into the air tube and connected to the left end of the hollow tube along with the air tube. According to the fact that the cutting fluid passes through the bending zone in the process of flowing to the hollow pipe in the fluid pipe, and when the cutting fluid passes through the bending zone, vortexes and air pockets are generated, strong impact and other phenomena occur, so that the friction resistance of the flowing fluid is increased, and local pressure loss is caused; in addition, the liquid has viscosity, and friction is generated between the liquid and the pipeline due to relative movement of the liquid and the pipeline caused by the viscosity, so that the liquid can cause pressure loss along the pipeline in the flowing process. Similarly, for gases, pressure losses are also caused when passing through the trachea.

(1) The on-way pressure loss of the cutting fluid in the fluid pipe can be divided into two parts, as shown in fig. 22(b), and one part is the pressure loss of the cutting fluid in the horizontal straight pipe before the cutting fluid is bent; some of them are pressure losses caused in the inclined pipe by the cutting fluid after the bending until the gas-liquid mixing point P. Calculating the on-way pressure loss of the two parts of the cutting fluid in the fluid pipe can be calculated by the following formula:

(2) when the cutting fluid passes through the bent portion in the fluid tube, the fluid movement resistance increases due to the bending, resulting in a pressure loss, as shown in fig. 22 (b). Calculating the local pressure loss of the cutting fluid at the bending part can be calculated by the following formula:

where ξ is the local drag coefficient.

From the above analysis, it can be known that the total pressure loss of the cutting fluid in the nozzle gas-liquid pipeline is:

the pressure loss for the gas in the trachea is:

the total pressure loss is then:

the total loss of pressure caused for the jet head gas-liquid line shown in form two is:

the third form: as shown in fig. 22(c), the end of the trachea is bent at 30 °, the liquid tube is a horizontal straight tube, and the end of the trachea is inserted into the liquid tube and connected with the left end of the hollow tube along with the liquid tube. According to the cutting fluid in the process of flowing to the hollow tube in the liquid pipe, liquid has the viscidity, because the viscidity makes liquid inside, because of relative motion between liquid and the pipeline produce the friction, so liquid also can cause along journey pressure loss in the flow process of pipeline. Similarly, for gases, pressure losses are also caused when passing through the trachea.

The on-way pressure loss of the cutting fluid in the fluid pipe can be calculated by the following formula:

the pressure loss for the gas in the trachea is:

the total pressure loss is then:

the total loss of pressure caused for the spray head gas-liquid line shown in the third form is:

comparing the total pressure loss of the three forms of nozzle gas-liquid pipeline structures, the delta P can be easily seen₂＞ΔP₁＞ΔP₃。

Therefore, in this embodiment, it is preferable that the end of the trachea is bent at 30 °, the liquid tube is a straight horizontal tube, and the end of the trachea is inserted into the liquid tube and connected to the left end of the hollow tube together with the liquid tube.

After the cutting fluid and the high-pressure gas are fused at the point P, the cutting fluid can be atomized under the action of the high-pressure gas, and the atomization of the cutting fluid can be divided into two modes of jet atomization and crushing atomization.

Jet atomization refers to that when lubricating oil is sprayed out in a continuous liquid form through an oil spray hole, the external air is stirred to enable the jet surface to form vibration waves. As the amplitude of the vibration wave increases, the jet will break up into flaky liquid and large diameter droplets. When the droplet diameter exceeds a critical value, it is broken into a large number of fine droplets. The droplet size depends on the nozzle configuration, the gas flow conditions, and the ambient conditions, among others.

Fragmentation and atomization as shown in fig. 23, which means that liquid droplets are broken into small oil droplets in various forms under the aerodynamic action of a high-speed air flow. Initially the droplets gradually changed to ellipsoidal, cup-shaped and semi-hydrated forms under the action of gas pressure. If the relative velocity of the high velocity gas stream and the droplets is large, above a critical value, the top of the semi-spherical droplets break first into an annular band of liquid that varies in thickness and contains 70% of the mass of the large diameter spherical droplets. Under the further tearing action of the airflow, the outer edge of the annular liquid band is separated into sheets, the central part is cracked into a large number of small liquid bubbles, and finally, the small liquid bubbles or the small liquid bubbles with different sizes are completely cracked.

In the gas-liquid pipeline structure of the third type of the spray head, the stress condition of the cutting liquid drops is as shown in figure 24,

wherein:

is the resultant force to which the droplet is subjected;

the viscous force of the airflow on the fog drops;

acting force of pressure gradient on the fog drops;

the force to which the cutting liquid drops are subjected under the action of pressure;

is gravity.

For the

In any event, there is a relative velocity of the ambient air flow and the movement of the droplets

The viscous force is then:

wherein: a. the_PIs the droplet frontal area; rho_fIs the gas density;

is the droplet velocity;

is the air flow velocity; c_DIs the coefficient of resistance.

Definition of Reynolds number as

Then

Wherein, mu_fIs the kinematic viscosity coefficient of the fluid; d_eThe diameter of the oil drop.

Setting velocity of air flow

With pressure gradient in the direction

Then

Because oil drops are sparse suspended phases, the airflow field is not disturbed due to the existence of fog drops, and the Navier-Stokes equation is still obeyed:

due to d_eVery small, the above formula can be simplified to

Then

As shown in FIG. 25, the section I-I and section II-II are taken at the position where the cutting fluid just enters the fluid pipe and the point P, respectively, and the Bernoulli equation of the two sections is shown

Then p'₂＝p₂+ρ₁g(h₁-h₂)-Δp_w

Wherein p is₂For the cutting fluid just enteringPressure in the liquid line, for form three, h₁-h₂＝0

Then:

the direction coincides with the drop velocity direction.

The self-gravity of the liquid drop is as follows:

wherein m is_pFor droplet mass, the direction of the droplet's own gravity is vertically downward.

The total resultant force experienced by the droplet is

Wherein the content of the first and second substances,

is a unit vector and is at an angle of 30 degrees downward from the positive x-axis half.

Being a unit vector, the direction points to the negative y-axis half.

The x and y directions of the droplets of the format three were subjected to force analysis, and the results are shown in fig. 26 (a).

According to the formula, it can be known

Is at an angle η to the horizontal coordinate X. Angle eta and air velocity

And the velocity of the cutting fluid droplets

In this regard, the force pattern is shown in FIG. 26(b),

direction and air velocity of

The consistency is kept between the first and the second,

direction of and speed of cutting fluid droplets

Consistent, gravitational force

Vertically downwards.

F_{3y is positive}＝F_{Dy plus}+F_{Py is positive}＝F_D sinη°+F_P sin30°

F_{3y is negative}＝F_W

F_{3x is}＝F_{Dx is positive}+F_{Px is}+F_Q＝F_D cosη°+F_Pcos30°+F_Q

Then a resultant force

Is of a size of

Then a resultant force

In the direction of

Resultant force to which cutting fluid droplets are subjected

Promoting the breaking of the droplet, wherein the critical force of the critical breaking point of the cutting fluid droplet is F_LThen a resultant force

Is different from the force of the critical breaking point of the droplet by the magnitude of (F)_AEffect of break-up of large and small reaction droplets:

F_A＝|F_∑-F_L|

as shown in FIG. 25, sections I-I and III-III were taken at the point where the gas just entered the trachea and at the point P, respectively, and Bernoulli's equation for both sections is presented

Then p'_q＝p_q+ρ₂g(h₃-h₂)-Δq

Wherein p is_qPressure of gas just entering trachea, h₃-h₂＝-l₂ sin30°

p′_q＝p_q-ρ₂gl₂sin30°-Δq

After the point P, the gas can drive the crushed cutting fluid droplets to flow into the hollow pipe, and the gas-liquid mixing pressure is

p₃＝p′₂+p′_q＝p₂-Δp_w+p_q-ρ₂gl₂sin30°-Δq＝p₂+p_q-ρ₂gl₂sin30°-ΔP₃

Let the flow rate of gas-liquid mixture be v₃。

When the gas-liquid two-phase flow flows to the nozzle, the orifice throttling phenomenon can occur because the pipe diameter is sharply reduced. As shown in fig. 25. At this point, the sections IV-IV and V-V are taken at locations where no constriction occurs in the entry and exit orifices, respectively, according to Bernoulli's equation:

in the formula h₂＝h₄；v₄Is much greater than v₃And thus v is ignored₃. ρ is the density of the gas-liquid two-phase flow, and ρ is ρ₂(1-ε)+ρ₁Epsilon. The flow of the constrictions exhibits turbulence, p₄Is the pressure behind the orifice; alpha is alpha₂Taking 1; Δ p_w1For local loss, take

The velocity of the gas-liquid two-phase flow at the nozzle outlet is:

the velocity of the droplet is also v₄。

Researchers have found, according to bernoulli's equation, that the gravity of the droplet itself is very small relative to the ambient air resistance to which the droplet is subjected before it hits the micro-grinding zone, and thus the gravity to which the droplet is subjected is negligible, taking into account the effect of the ambient air viscous resistance on the droplet. From the aerodynamic principle, the resistance of the air surrounding the droplet to the droplet is known:

in the formula: v. of_aIs the ambient air velocity; gamma ray_aIs the air gravity; s_fIs the liquid drop head-on area; c_DIs the air resistance coefficient; g is the acceleration of gravity.

Since the flow velocity of the air around the liquid droplets is much smaller than that of the high-velocity liquid droplets, the air around the liquid droplets is regarded as a stationary state, and the formula can be expressed as

When the spray boundary is a sealThe closed ellipse maximizes the droplet population coverage. Total number of drops N_t：

In the formula: q_fSupplying liquid flow to the spraying device; f is the frequency of the liquid supply of the minimal quantity lubrication device; v_d32Has a particle diameter of d₃₂The drop volume of (a). d₃₂The physical meaning of the particle size is a Sauter mean particle size (Sauter mean particle size): the ratio of the volume mean of all droplets to the area mean of all droplets produced by the spray. The particle diameter d is commonly adopted by researchers₃₂The droplet group of (2) is substituted for the original droplet group, and the total volume and surface area of the droplet group are equal to those of the original droplets. d₃₂General expression of (a):

in the formula: sigma_tIs the surface tension coefficient of the droplet; mu is the dynamic viscosity of the spraying medium; rho_aIs the density of the nozzle outlet ambient medium; d₀Is the nozzle diameter.

Assuming that the spray droplets fall uniformly on the workpiece surface, the number of droplets falling in the machining zone:

in the formula: s_gThe area of cutting processing; s_eIs the spray boundary elliptical area.

The description of the initial droplet size uses the χ 2-distribution:

in the formula:

to determine degrees of freedom

Corresponds to chi²-the maximum of the distribution.

The Weber criterion number (called We number for short) and the Laplace number (La number) are used for controlling the result after the liquid drop collides with the surface of the heat source:

in the formula: rho_fIs the density of the spray cooling medium; v. of₆Is the velocity component of the droplet perpendicular to the heat source surface; sigma flow stress of the first deformation zone corresponding to the minimum chip thickness; mu spray medium dynamic viscosity; d, spray droplet size.

As shown in fig. 27, the horizontal distance from the nozzle to the workpiece is X, the angle between the nozzle and the horizontal surface is δ, and according to the energy conservation:

vertical velocity v at which the droplet lands on the surface of the workpiece by velocity analysis₆Is composed of

As shown in fig. 28, the 3 behaviors of bouncing, spreading and splashing occur in sequence with the gradual increase of the number of incident droplets We. When the initial droplet energy is low, the droplet rebounds; when the liquid drops impact the surface of a heat source with high energy, a crown-shaped liquid drop splash is formed, and the liquid drops fly away from the edge of the crown shape and are broken into a plurality of small liquid drops. In both cases, the liquid drops can not effectively participate in heat exchange, and only when the liquid drops spread, namely the liquid drops impact the surface of the heat source and then spread into a liquid film along the surface of the heat source, the effective heat exchange can be carried out on the surface of the heat source. The drop where spreading occurs, its critical We number:

2.0×10⁴×La^-0.2≤We≤2.0×10⁴×La^-1.4

the range of the droplet particle diameter D which can be effectively subjected to heat exchange and spread can be calculated according to the formula: d_min≤D≤D_max. Therefore, the proportion of effective heat exchange liquid drops is as follows:

in the formula:

to determine degrees of freedom

Correspond to

Probability maximum of distribution

Number of droplets for effective heat exchange:

N_e＝N_z·P(D)

the base liquid and high-pressure gas sprayed from the nozzle to the surface of the heat source are regarded as two streams of fluid and high-pressure gas. Carrying out probability statistical analysis according to the counted effective heat exchange liquid drops in the processing interval, and calculating the heat exchange coefficient of a single fluid liquid drop so as to obtain the heat exchange coefficient of the fluid; the heat exchange coefficient of the high-pressure gas jet is added, namely the convective heat exchange coefficient under the spray cooling condition of the external cooling micro-lubricating jet in the internal cooling and external cooling system.

For a single fluid droplet, the heat transfer coefficient h_sSatisfies the following conditions:

in the formula: j is the heat exchange amount of a single liquid drop; c. C_fIs the specific heat capacity of the liquid drop; delta T is heat exchange temperature difference；q_sHeat flux density for heat exchange of a single droplet; t is t_sThe heat exchange time is; m is_dIs the mass of the droplet; a' is the spreading area of the droplet.

Based on the calculation of the number of effective liquid drops in the processing area, the heat exchange coefficients of all effective heat exchange liquid drops can be known:

convective heat transfer coefficient h between high-pressure gas jet and heat source surface_a：

In the formula: nu is the Nu-seoul number, which is related to the reynolds number (Re), prandtl number (Pr):

in the formula: k is a radical of_aIs the thermal conductivity of air; mu.s_aIs a aerodynamic viscosity; c. C_aThe isobaric specific heat capacity of air.

Convection heat transfer coefficient under the spray cooling condition of external cooling micro-lubricating jet in the internal cooling and external cooling system: h is h_n+h_a

The information transmission modes are wireless transmission and can be transmitted by using the Internet, such as GPRS, 2G, 3G, 4G and the like. The wireless transmission technology is mature technology, and the wireless transmission technology is provided with a complete working module and can be directly used.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (10)

1. The utility model provides a mill trace lubricating system, characterized by includes outer cold system and interior cold system, inserts the cutting fluid supply source through the switching-over device jointly, and outer cold system includes shower nozzle device, flexible arm module and shower nozzle angle module, the shower nozzle device passes through shower nozzle angle module and installs on flexible arm module, and the shower nozzle device can change the relative position with the work piece through flexible arm module and change shower nozzle device output end orientation through shower nozzle angle module, and the shower nozzle device intercommunication air supply for obtain gaseous and mix the cutting fluid of obtaining from the cutting fluid supply source back output from the air supply.

2. The milling minimal lubrication system according to claim 1, wherein the internal cooling system comprises an internal cooling conduit for disposition within a spindle of a machine tool, the internal cooling conduit communicating with a supply of cutting fluid through a reversing device.

3. The milling minimal quantity lubrication system as claimed in claim 1, wherein the reversing device comprises a reversing base, a reversing channel is arranged in the reversing base, an inlet of the reversing channel is in butt joint with a cutting fluid supply source through a pipeline, a first outlet of the reversing channel is communicated with an internal cooling system, a second outlet of the reversing channel is communicated with an external cooling system, a reversing block is arranged in the reversing channel, and the reversing block can seal the first outlet and/or the second outlet through rotation.

4. The milling minimal quantity lubrication system according to claim 3, wherein the reversing base is provided with a pressure regulating structure and a pressure relief structure, and the pressure regulating structure and the pressure relief structure are both communicated with the reversing channel.

5. The milling minimal quantity lubrication system according to claim 4, wherein the pressure regulating structure comprises a pressure regulating valve core, a pressure regulating spring and a pressure regulating nut, the pressure regulating valve core and the pressure regulating spring are both installed in a pressure regulating channel preset in the reversing base, the pressure regulating channel is communicated with the reversing channel, and the pressure regulating nut is matched with the pressure regulating valve core and used for changing the plugging area of the reversing channel by the pressure regulating valve core.

6. The milling minimal lubrication system according to claim 1, wherein the telescopic arm module is a three-axis robotic arm, the output end is connected to the spray head angle module, and the other end is adapted to be fixed to a machine tool.

7. The milling minimal quantity lubrication system according to claim 6, wherein the telescopic arm module comprises a telescopic arm support, an X-axis actuating arm, a Y-axis actuating arm and a Z-axis actuating arm, the X-axis actuating arm is mounted on the telescopic arm support through the Z-axis actuating arm, the Y-axis actuating arm is mounted on the telescopic arm support, and the spray head angle module is mounted at an output end of the Y-axis actuating arm through magnetic force.

8. The milling minimal quantity lubrication system as claimed in claim 1, wherein the nozzle device comprises a gas pipe, a liquid pipe and a gas-liquid pipe, one end of the gas pipe is communicated with a gas source, the other end of the gas pipe is communicated with the gas-liquid pipe, the axis of the gas pipe and the axis of the gas pipe form a set included angle, one end of the liquid pipe is communicated with a cutting fluid supply source through a reversing device, the other end of the liquid pipe is coaxially butted with the gas pipe, a gas-liquid mixing cavity is formed inside the gas pipe, and the gas-liquid mixing cavity is communicated.

9. The milling minimal quantity lubrication system as claimed in claim 8, wherein a baffle is arranged at one end of the gas-liquid pipe away from the liquid pipe, a through hole serving as a spraying hole is arranged in the center of the baffle, and the gas-liquid mixing cavity is output through the through hole.

10. The milling minimal lubrication system according to claim 1, wherein the spray head angle module comprises a first rotation module and a second rotation module, the spray head device being mounted at an output end of the second rotation module, the second rotation module being mounted at an output end of the first rotation module for changing an orientation of the output end of the spray head device.

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