JP2006082151A - Mist generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably generate oil mist used for a nozzle for semi-dry working without generating coarse drips. <P>SOLUTION: The mist generator comprises a liquid supply passage 6 for drips, a porous liquid flow-out part 8 to which the liquid for drips is fed from the liquid supply passage 6, a piled drip supply part 9 for feeding drips to a gas flow, and an ultrasonic vibrator 10 for applying ultrasonic vibration to the drip supply part 9. The liquid for drips fed from a drip liquid supply passage 4 to the porous liquid flow-out part 8 flows out from the liquid flow-out surface of the porous liquid flow-out part 8 and is dripped at the drip supply part 9. The drips are cut by the vibration of the ultrasonic vibrator 10 and taken in the gas flow to be misted. In this way, fine mist with uniform particle size can be generated and supplied. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mist generator that generates mist such as oil mist used in semi-dry processing.

Conventionally, an oil mist processing method or a semi-dry processing method has been employed for processing a minute lubricating oil. In these methods, the atomized mist is transported to the vicinity of the processing point with compressed air and injected from the nozzle at the tip of the pipe. The amount of air injected from the nozzle is determined from the air flow rate determined from the operating conditions of the lubricating oil device and the flow rate loss due to the length of the pipe and the bent portion. Also, in machining that does not like chip accumulation, such as die machining, or ball end milling where the position of the machining point changes constantly, multiple nozzles are provided so that the lubricating oil is evenly injected, or chips are blown away. As shown in the figure, a nozzle dedicated to air from which only compressed air is injected is provided. In addition, for the purpose of blowing off chips and cooling the processing point, an air increasing nozzle is proposed in which the surrounding air is entrained and the amount of injected air is increased only by supplying compressed air (for example, Patent Document 1). ).
There has also been proposed a mist generating device that impregnates a liquid retaining member with water and oil, and sucks the water and oil impregnated into the liquid retaining member into a pore plate that is resonated by an ultrasonic vibrator to generate mist. (See Patent Document 2).
Japanese Patent Laid-Open No. 7-24685 JP 2003-170332 A

However, as a problem of the conventional lubricating oil system, there is a limit to the amount of supply air used for one nozzle, the mist particle size tends to increase, and it is difficult to generate mist with a fine and uniform particle size. There's a problem. In addition, the air increasing nozzle has a problem that since the air is increased to the mist of air, it is difficult to obtain a mist refining action, which causes oil droplets to be combined and increases the mist particle size.
Further, in the method according to Patent Document 2, the amount of water and oil sucked from the liquid retaining member to the pore plate is limited, and it is difficult to suck water and oil evenly, so that a fine and uniform mist is effective. There is a problem that it is difficult to generate and supply it.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a mist generating device that can effectively supply uniformly atomized mist.

  That is, among the mist generating apparatuses of the present invention, the invention according to claim 1 is a mist generating apparatus that generates a mist in which droplets are finely mixed in a gas flow. A porous liquid outflow part connected to the liquid supply path and supplied with liquid for droplets from the supply path, and a nap that is provided on the liquid outflow surface of the porous liquid outflow part and supplies liquid droplets to the gas flow A liquid droplet supply unit, and an ultrasonic transducer that applies ultrasonic vibration to the liquid droplet supply unit.

  The invention of claim 2 is characterized in that, in the invention of claim 1, the ultrasonic transducer is arranged so as to transmit ultrasonic vibration from a tip of the droplet supply unit. Do

  According to a third aspect of the present invention, in the first or second aspect of the invention, the droplet supply unit has a shape that tapers toward the tip.

  The invention of a mist generator according to claim 4 is the invention according to any one of claims 1 to 3, wherein the mist generator is configured to generate the mist in a nozzle serving as a gas flow path. On the inner peripheral surface of the nozzle, a slit along the circumferential direction is formed toward the downstream direction of the gas flow, and a flow rate increase configured by connecting a compressed gas supply unit that supplies compressed gas to the slit. A mechanism is provided.

  That is, according to the present invention, the liquid for droplets is supplied to the porous liquid outflow portion through the liquid supply passage for liquid droplets, and flows out to the liquid outflow surface through the pores of the porous liquid outflow portion. Further, the liquid for droplets moves on the surface of the liquid droplet supply part standing on the liquid outflow surface of the porous liquid outflow part, and is finely dropletized. Then, ultrasonic vibration is transmitted to the surface of the droplet supply unit by the ultrasonic vibrator, and the droplets on the surface of the droplet supply unit smoothly flow and are further miniaturized. These fine droplets are taken into the gas flow and mist is generated. At that time, for example, uniform droplets having a particle size of 10 μm or less are generated and misted.

  If the ultrasonic vibration is transmitted to the tip side of the droplet supply unit, the ultrasonic vibration is transmitted to the unconstrained side, so that the vibration level of the droplet supply unit increases and the liquid droplets are refined. Becomes larger. Further, if the droplet supply portion is tapered toward the tip, the vibration level on the tip side can be further increased, and the droplet miniaturization effect can be further increased.

  Further, if a slit along the circumferential direction is formed on the inner peripheral surface of the nozzle in the downstream direction of the gas flow, and a flow rate increasing mechanism for supplying the compressed gas to the slit is provided, the compressed gas injected from the nozzle Entrains the surrounding gas from the upstream side of the slit, effectively increasing the gas flow. If this flow rate increasing mechanism is provided on the upstream side of the droplet supply section, the droplets are directly taken into the increased gas flow, so that it is difficult for the droplets to combine, and the shearing force of the increased gas flow is further increased. As a result, the effect of further miniaturizing the droplet can be obtained.

  A typical example of the fluid that forms liquid droplets with the mist includes a lubricating oil. However, the present invention is not limited to this, and paints, adhesives, and the like can be misted. In addition, air is usually provided as a gas in the mist, but a gas such as nitrogen, oxygen, carbon dioxide, or the like can be used as necessary, and the present invention is not limited to a specific gas.

  In addition, porous bodies, such as a foam metal, foam ceramics, a sintered filter, are used for the porous liquid outflow part used by this invention. However, the present invention is not limited to the porous material described above, and may be a porous material made of other materials. However, the porous liquid outflow part needs to be able to move the liquid supplied from the liquid supply path for liquid droplets to the liquid outflow surface of the outflow part, and the movement of the liquid is achieved by having a porous continuity. The

  In addition, a fiber body such as a chemical fiber, an animal fiber, or a plant fiber can be used for the nap-like droplet supply unit used in the present invention. However, the present invention is not limited to the materials described above, and may be made of other materials. Further, as described above, it is desirable that the shape of the droplet supply unit be tapered toward the tip. The thickness and length of the droplet supply unit are not particularly limited, and can be appropriately determined depending on the area of the porous liquid outflow unit and the size and amount of the supplied droplet. For example, a thing with a diameter of 50-100 micrometers and a length of 0.1-1 mm can be mentioned.

  Furthermore, the ultrasonic transducer used in the present invention is disposed so as to give the ultrasonic transducer to the droplet supply unit, and the structure and frequency of the ultrasonic wave are not particularly limited. However, as described above, it is desirable to arrange so as to apply ultrasonic waves to the tip of the droplet supply unit, so that the droplets can be efficiently taken into the fluid from the droplet supply unit. Instead, it is desirable to dispose it on the tip direction side of the droplet supply section.

  As described above, according to the present invention, in a mist generating device that generates mist in which droplets are finely mixed in a gas flow, the droplet liquid supply path is connected to the droplet liquid supply path, A porous liquid outflow part to which liquid for liquid droplets is supplied from a supply path; and a nail-like liquid droplet supply part that is installed on the liquid outflow surface of the porous liquid outflow part and supplies liquid droplets to the gas flow; An ultrasonic vibrator that applies ultrasonic vibration to the liquid droplet supply unit, so that liquid droplets having a fine and uniform particle diameter can be generated and misted. The liquid is smoothly supplied through the porous liquid outflow portion and the droplet supply portion. That is, it becomes possible to stably generate and supply a mist having a fine and uniform particle diameter.

  In addition, a slit along the circumferential direction is formed on the inner peripheral surface of the nozzle serving as a gas flow path in the downstream direction of the gas flow, and a compressed gas supply unit that supplies the compressed gas to the slit is connected. By configuring the flow rate increasing mechanism, it is possible to generate a mist of a fluid that contains fine droplets and is increased.

In particular, when oil mist for processing is generated, if the mist is generated in the nozzle, fine and uniform mist can be stably supplied near the discharge side.
In addition, in the present invention, there is an effect that oil droplets having a fine particle diameter are generated, but if the oil droplets are small, the weight thereof is lightened. For this reason, when it is necessary to break through the air layer generated by the rotation of the tool and allow the mist to enter the machining point, the penetration force may not be sufficient. However, if the flow rate increasing mechanism is provided as described above, the invasion force is increased, and oil droplets having a fine particle diameter can reach the processing point. That is, the present invention provided with the flow rate increasing mechanism also has a feature that the lubrication function is improved by utilizing the features of the mutual elements.
That is, since the present invention can effectively lubricate and cool the machining point with a simple structure having only one nozzle, for example, it can be expected to improve machining efficiency, improve machining quality, and extend tool life.

(Embodiment 1)
Below, one Embodiment of this invention is described based on FIGS.
As shown in FIG. 1, the mist generator has a nozzle 1 having a gas flow path 2 therein.
The gas flow path 2 has a gas flow path upstream opening 2a that is largely open at an upstream end (right side in FIG. 1), and a gas flow path discharge opening 2c at a downstream end. The gas flow path 2 is narrowed in a tapered shape from the gas flow path upstream portion 2a toward the downstream side, and the gas flow path narrowing portion 2b is located at about 1/3 of the upstream side in the length direction of the nozzle 1. have. Further, the gas flow path 2 is formed in a tapered shape having a large diameter from the throttle portion 2b toward the gas flow path outlet 2c.

In addition, a slit 3 is formed on the inner peripheral surface of the nozzle 1 on the upstream side of the gas flow passage restricting portion 2b and directed to the downstream side over the entire circumference. A buffer chamber 4 formed in an annular shape in the nozzle 1 communicates with the slit 3 over the entire circumference, and a compressed fluid supply path 5 that opens to the outer peripheral surface of the nozzle is connected to the buffer chamber 4. Yes. The compressed gas supply path 5 is connected to a compressed gas supply unit (not shown). Examples of the compressed gas supply unit include a compressor and a blower. The above-described slit, compressed gas supply path, and compressed gas supply section constitute the flow rate increasing mechanism of the present invention.
As shown in FIG. 2, the nozzle 1 can be composed of an upstream nozzle member 1a and a downstream nozzle member 1b that are divided in the axial direction along the shape of the slit 3. The slit 3 can be formed by providing a gap between the slope 3a of the upstream nozzle member 1a and the slope 3b of the downstream nozzle member 1b.

  Further, as shown in FIGS. 1 and 3, a lubricating oil supply pipe 6 corresponding to the fluid supply path for liquid droplets of the present invention is disposed on the downstream side of the gas flow path narrowing portion 2b. One end of the lubricating oil supply pipe 6 opens on the outer peripheral surface of the nozzle 1, extends from the opening to the center of the nozzle 1 along the radial direction, and is deflected upstream in the axial direction at the center. ing. The one end of the lubricating oil supply pipe 6 is connected to a lubricating oil supply unit (not shown) through an opening in the outer peripheral surface of the nozzle. The lubricating oil supply unit includes an oil storage tank, a pump, and the like.

In addition, a porous liquid outflow portion 8 is connected and fixed to the opening at the tip of the lubricating oil supply pipe 6 inside the nozzle 1 on the downstream side of the gas flow passage restricting portion 2b. The lubricating oil supply pipe 6 and the porous liquid outflow portion 8 can be fixed by brazing, welding, adhesion, or the like.
The porous liquid outflow portion 8 is formed in a columnar shape by a porous body such as foam metal, and is arranged so that the central axis is along the axial direction of the nozzle 1. The outer peripheral surface and the downstream end surface are covered with the resin 8a except for the connecting portion with the lubricating oil supply pipe 6. The porous liquid outflow portion 8 is formed such that micropores are dispersed inside and on the surface and the pores are continuous with each other. Therefore, the upstream end surface of the porous liquid outflow portion 8 to which the lubricating oil is supplied becomes the liquid outflow surface.

A plurality of droplet supply portions 9 are planted and arranged in a brush shape on the upstream tip surface (liquid outflow surface) of the porous liquid outflow portion 8 in a raised state. The droplet supply unit 9 has a shape with a small diameter toward the tip, and can be constituted by a fibrous body, for example.
An ultrasonic transducer 10 is disposed on the tip side of the droplet supply unit 9, and the vibration surface of the ultrasonic transducer 10 comes into contact with the tip of the droplet supply unit 9 so that the ultrasonic vibration of the ultrasonic transducer 10 is dropped. It is comprised so that it may be transmitted to a supply part.
The droplet supply unit 9 and the ultrasonic transducer 10 are located in a cylindrical holding case 11 and are held by the case 11 (the holding mechanism is omitted). The holding case 11 is held by a holding member 11a. It is attached to the inner peripheral surface of the nozzle 1.

Next, the operation of the mist generator will be described.
Lubricating oil is supplied to the lubricating oil supply pipe 6 from a lubricating oil supply unit (not shown). Then, the lubricating oil is supplied to the porous liquid outflow portion 8 through the lubricating oil supply pipe 6 and flows out to the liquid outflow surface through the pores of the porous liquid outflow portion 8. As shown in FIGS. 3 and 4, the lubricating oil that has flowed out to the liquid outflow surface is formed into droplets while smoothly flowing on the surface of the droplet supply unit 9. The droplet supply unit 9 is less likely to drop oil droplets in the process of generating oil droplets regardless of the orientation of the nozzle, and can efficiently supply droplets into the gas.
In addition, ultrasonic vibration is applied to the droplet supply unit 9 by the ultrasonic vibrator 10, and the tip side that is not restrained by the base end side that is restrained by the droplet supply unit 8 has a greater vibration level. It vibrates to become. Further, since the droplet supply unit 9 has a shape that tapers toward the tip, it tends to vibrate toward the tip based on the shape, and the difference in the vibration level becomes more remarkable. FIG. 5 shows a change in the particle size of the droplet (lubricating oil) depending on the position of the droplet supply unit 9 in the length direction. The vibration level is larger on the tip side than on the base side, and the droplet size is It can be seen that it is significantly smaller. The droplet 20 of the droplet supply unit 9 is refined as it moves toward the tip, and is finally taken in as mist 21 in the gas.
The nap-like droplet supply unit 9 is easy to vibrate and is independent of each other rather than being an integrated object. Therefore, the vibration area is widened and oil droplets can easily flow, so that mist can be generated efficiently.

On the other hand, compressed air as compressed fluid is supplied to the compressed fluid supply pipe 5 from a compressor or a blower (not shown). The compressed air is accommodated in the buffer chamber 4 and then injected through the slit 3 into the nozzle 1 and toward the downstream side. Then, the upstream air is drawn in as the drawn-in air by the jetted compressed air, and the air flow is increased and jetted downstream. The increased air flow is squeezed by the gas flow passage restricting portion 2b as the gas flow passage 2 is moved downstream, and the flow velocity is increased, and the inside and outside of the holding case 11 is moved downstream. The air flow that moves in the holding case 11 takes in the mist 21 generated as described above, moves to the downstream side, and merges with the air flow that moves on the outer peripheral side of the holding case 11. In addition, the air flow which took in mist is moving in the gas flow path 2 which becomes large diameter gradually, and it becomes difficult to produce | generate the coupling | bonding of mist, and the discharge air containing fine mist is gas flow. It discharges outside from the road discharge port 2c. Further, a shearing force acts on the mist by the sufficiently accelerated air flow, and an effect of further miniaturizing the droplet can be obtained.
That is, in this mist generating apparatus, fine oil droplets can be generated stably, and mist can be generated stably without generating coarse oil droplets.
Further, in this embodiment, since the amount of gas can be increased without causing mist coarsening, even when it is necessary to break through the air layer around the processing tool and allow the mist to enter the processing point, fine particles Oil droplets having a diameter can easily reach the processing point.

Next, an example in which the shape of the holding case is changed will be described with reference to FIG. In addition, about the structure similar to the structure demonstrated in the said embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
In FIG. 6, a cylindrical holding case 12 is disposed on the outer peripheral side of the porous liquid outflow portion 8, the droplet supply portion 9, and the ultrasonic transducer 10 as in the above description. The holding case 12 has a tapered shape having a large inner diameter on the upstream side and a small inner diameter on the downstream side. By having such a tapered shape, a throttling action is given to the fluid flowing into the holding case 12, and there is an effect of increasing the flow rate of the fluid toward the downstream side. Thereby, there exists an effect | action which refines | miniaturizes mist further.

It is principal part sectional drawing which shows the mist generator of one Embodiment of this invention. Similarly, it is the disassembled perspective view which cut down the part which shows a nozzle. Similarly, it is an enlarged view which shows a part of mist generator. Similarly, it is a figure which shows a mist production | generation process. Similarly, it is a correlation diagram of a mist particle size and a vibration level. It is an enlarged view which shows a part of other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nozzle 2 Gas flow path 3 Slit 5 Compressed fluid supply path 6 Lubricating oil supply pipe 8 Porous liquid outflow part 9 Droplet supply part 10 Ultrasonic vibrator 11 Holding case 12 Holding case 20 Droplet 21 Mist

Claims (4)

In a mist generator that generates mist in which droplets are finely mixed in the gas flow,
A liquid supply path for liquid droplets, a porous liquid outflow portion connected to the liquid supply path for liquid droplets and supplied with liquid for droplets from the supply path, and a liquid outflow surface of the porous liquid outflow section. A mist generating apparatus comprising: a nap-like droplet supply unit that supplies droplets to a gas flow; and an ultrasonic transducer that applies ultrasonic vibrations to the droplet supply unit.   2. The mist generating apparatus according to claim 1, wherein the ultrasonic transducer is arranged to transmit ultrasonic vibration from a tip of the droplet supply unit.   The mist generating apparatus according to claim 1, wherein the droplet supply unit has a shape that tapers toward a tip.   A mist generating device for generating the mist in a nozzle serving as a gas flow path, wherein a slit along the circumferential direction is formed on the inner peripheral surface of the nozzle in the downstream direction of the gas flow. The mist generator according to any one of claims 1 to 3, further comprising a flow rate increasing mechanism configured by connecting a compressed gas supply unit that supplies compressed gas to the slit.

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