JP6836844B2 - Ventilation member - Google Patents

Description

The present invention relates to a ventilation member.

Conventionally, automobile lamps such as headlamps, rear lamps, fog lamps and turn signals, inverters, converters, ECUs (Electronic Control Units), battery boxes and other devices have been ventilated to eliminate the differential pressure generated inside the housing due to temperature changes. Sex is required. In addition, these devices are required to have dust resistance to prevent foreign matter from entering the housing, water resistance to prevent water from entering, oil repellency to prevent oil from entering, and CCT to prevent salt from entering. There is. Therefore, a ventilation member having these functions of breathability, dust resistance, water resistance, oil repellency, and CCT resistance is attached to the device.
For example, in the ventilation cap (ventilation member) described in Patent Document 1, a substantially cylindrical substantially cylindrical body is fitted in a bottomed cylindrical cover component, and the inner circumference of the cover component and the substantially tubular body are formed. A ventilation path is formed between the outer circumference and the bottom surface of the cover component and the bottom of the substantially tubular body, and the top opening of the substantially tubular body is formed in the mounting portion to be mounted on the mounting opening of the device housing. Has been done. Further, the bottom opening of the substantially tubular body is covered with a breathable filter member.

Japanese Unexamined Patent Publication No. 2001-143524

By the way, for example, a ventilation member attached to an automobile part has a function of adjusting the pressure inside the housing by circulating (ventilating) gas between the internal space and the external space of the housing. Specifically, when the pressure in the internal space of the housing is higher than the pressure in the external space of the housing, the gas in the housing is discharged from the internal space of the housing to the external space via the ventilation member. On the contrary, when the pressure in the internal space of the housing is lower than the pressure in the external space of the housing, the gas outside the housing is sucked from the external space of the housing to the internal space via the ventilation member. When a liquid such as oil is contained in the internal space of the housing, floating particles of the liquid such as oil mist are suspended. Then, the pressure in the internal space of the housing is higher than the pressure in the external space of the housing, and when the gas in the housing is discharged from the internal space of the housing to the external space via the ventilation member, it floats. Liquid suspended particles may adhere to the ventilation film (filter member). If a large amount of liquid suspended particles adhere to the porous body (filter member) that prevents the ingress of liquids and solids and allows ventilation, the ventilation may be hindered and the function of adjusting the pressure inside the housing may be impaired. ..
An object of the present invention is to provide a ventilation member capable of suppressing impairing the function of adjusting pressure in a housing due to adhesion of a large amount of liquid suspended particles to a porous body.

For this purpose, the present invention collects the first porous body (10), which prevents the invasion of liquids and solids and has a plurality of pores through which gas permeates, and the liquid and liquid suspended particles, and also gas. A second porous body (20) in which a plurality of holes are formed to allow the permeation of the gas, and between the first porous body (10) and the first porous body (10) without contacting the first porous body (10). The ventilation member (1) is provided with a second porous body (20) arranged so that gas can permeate through the gap.

Here, the second porous body (20) is preferably a film having no portion where the curvature ratio is 1 obtained by dividing the path length of the gas by the thickness.
Further, the pore diameter of the second porous body (20) is preferably larger than the pore diameter of the first porous body (10).
Further, the second porous body (20) is preferably a porous body or foam of at least one of resin, ceramic and metal.

Further, it is attached to the opening of the housing (100) containing the liquid and the liquid floating particles or a member attached to the housing (100), and communicates between the internal space and the external space of the housing (100). It is preferable that the mounting member (30) having the communication hole (33) formed therein is further provided, and the first porous body (10) and the second porous body (20) are held by the mounting member (30). ..
Further, in the housing (100), a driving device that operates smoothly due to the presence of liquid and liquid suspended particles and generates heat by operating is housed, and the second porous body (20) is driven. It is preferable that the first porous body (10) does not come into contact with the first porous body (10) even when the device is operating.

From another point of view, the present invention is attached to the opening of the housing (100) containing the liquid and the liquid suspended particles or a member attached to the housing, and is attached to the internal space of the housing (100). A mounting member (30) having a communication hole (33) for communicating with an external space, and a mounting member (30) mounted on the mounting member (30) so as to cover an opening on the external space side of the communication hole (33). It is mounted on the mounting member (30) on the internal space side of the first porous body (10) so as not to contact the 1 porous body (10) and the first porous body (10), and has a gas path length. The ventilation member (1) is provided with a second porous body (20) having no portion where the curvature ratio is 1 divided by the thickness.

From another point of view, the present invention is attached to an opening of a housing (100) having a liquid and liquid suspended particles in an external space or a member attached to the housing (100), and the housing is mounted. A mounting member (430) having a communication hole (33) for communicating the internal space and the external space, a first porous body (10) mounted on the mounting member (430), and the first porous body. A portion that is mounted on the mounting member (430) on the external space side of the first porous body (10) so as not to come into contact with (10), and has a curvature ratio of 1 obtained by dividing the gas path length by the thickness. The ventilation member (400) is provided with a second porous body (20) in which is not present.

Here, the pore diameter of the second porous body (20 or 420) is preferably larger than the pore diameter of the first porous body (10 or 410).

It should be noted that the above-mentioned reference numerals in this column are exemplarily attached in the description of the present invention, and the present invention is not reduced by these reference numerals.

According to the present invention, it is possible to prevent the function of adjusting the pressure in the housing from being impaired due to the attachment of a large amount of liquid suspended particles to the porous body.

It is a figure which shows the schematic structure of the ventilation member which concerns on embodiment. It is sectional drawing of the ventilation member which concerns on embodiment, and is sectional drawing of the part II-II of FIG. It is a schematic diagram which shows the curve ratio. (A) is a schematic view of the experimental apparatus, and (b) is an enlarged view of the IVb portion of (a). It is a figure which showed the appearance result about the oil adhesion to the 1st film when the 2nd film was made different. (A) is a schematic configuration diagram of the ventilation member according to the first modification, and (b) is a cross-sectional view of the VIb-VIb portion of (a). It is sectional drawing of the ventilation member which concerns on modification 2. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a diagram showing a schematic configuration of a ventilation member 1 according to an embodiment.
FIG. 2 is a cross-sectional view of the ventilation member 1 according to the embodiment, and is a cross-sectional view of a portion II-II of FIG.
The ventilation member 1 is attached to a device housing 100 such as a transmission case for accommodating a transmission of an automobile, a cylinder block for accommodating each component constituting an engine, a cylinder head, and a crankcase. That is, the ventilation member 1 is attached to the device housing 100 that houses the drive mechanism that operates smoothly when the liquid intervenes and generates heat when it operates. Alternatively, the ventilation member 1 is mounted on the equipment housing 100 in an environment in which the liquid and the liquid suspended particles are present. In FIG. 2, a two-dot chain line shows a mounted portion 110, which is a portion for mounting the ventilation member 1 and has an open end, which is provided in the device housing 100. Further, the ventilation member 1 may be attached to the tip of a hose or tube attached to the attached portion 110 of the device housing 100.

The liquid contained in the equipment housing 100 includes lubricating oils such as engine oil, gear oil, machine oil, spindle oil, refrigerating machine oil (mineral oil type), cup grease, lithium grease, silicone grease, ATF, and CVT oil. It can be exemplified that there is. Further, as the liquid, it can be exemplified that it is a hydraulic oil such as turbine oil, oil + water emulsion type, water + glycol type, phosphoric acid ester type, silicone type, brake oil, torcon oil and the like. Further, as the liquid, it can be exemplified that it is a fuel such as light oil / kerosene, heavy oil, and gasoline.

The ventilation member 1 has holes that prevent liquids and solids from entering the internal space of the equipment housing 100 and allow gas to flow (permeate) between the internal space and the external space of the equipment housing 100. It has a ventilation film 10 as an example of a plurality of first porous bodies formed. Examples of the liquid that the ventilation membrane 10 can prevent intrusion include water, salt water, muddy water, and washing water.

Further, the ventilation member 1 is arranged closer to the internal space side of the equipment housing 100 than the ventilation membrane 10 so as not to come into contact with the ventilation membrane 10, and collects liquid suspended particles (for example, oil mist) and gas is discharged to the equipment housing. It has a collecting membrane 20 as an example of a second porous body in which a plurality of holes allowing flow (permeation) between the internal space and the external space of 100 are formed. It can be exemplified that the liquid floating particles that can be collected by the collecting film 20 are the liquid liquid floating particles housed in the equipment housing 100 described above. Further, the collecting membrane 20 collects the liquid contained in the equipment housing 100 described above.

Further, the ventilation member 1 is an example of a mounting member mounted on the mounted portion 110 as an example of the opening of the device housing 100, and will be described later that communicates the internal space and the external space of the device housing 100. The communication hole 33 is formed, and the holding member 30 for holding the ventilation film 10 and the collection film 20 is provided.
Further, the ventilation member 1 has a cover member 40 that covers the periphery of the ventilation membrane 10.

<< Ventilation membrane 10 >>
The ventilation film 10 is a disk-shaped film. The outer diameter of the ventilation film 10 is larger than the diameter of the second communication hole 332 described later and smaller than the diameter of the inner peripheral surface of the side wall portion 41 described later of the cover member 40.
The structure and material of the ventilation membrane 10 are not particularly limited as long as it is a membrane that allows the permeation of gas and blocks the permeation of liquid. It can be exemplified that the breathable membrane 10 is a mesh-like or fibrous-like cloth, resin or metal. For example, the breathable film 10 can be exemplified as a woven fabric, a non-woven fabric, a resin mesh, a net, a sponge, a metal porous body, or a metal mesh.

The ventilation membrane 10 according to the present embodiment is a membrane in which a reinforcing layer for increasing the strength of the ventilation membrane 10 is laminated on a resin porous membrane.
Examples of the material of the resin porous film include a fluororesin porous body and a polyolefin porous body that can be produced by a known stretching method or extraction method. Examples of the fluororesin include PTFE (polytetrafluoroethylene), polychlorotrifluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer and the like. Examples of the monomers constituting the polyolefin include ethylene, propylene, 4-methylpentene-1,1 butene, and the polyolefin obtained by polymerizing or copolymerizing these monomers alone is used. Can be done. Further, the material of the resin porous film may be a blend of two or more types of the above-mentioned polyolefins, or may have a layered structure.
Further, as the material of the resin porous membrane, a nanofiber film porous body using polyacrylonitrile, nylon, polylactic acid and the like can be exemplified.

In view of the fact that the ventilation membrane 10 according to the present embodiment can obtain a sufficient ventilation amount even in a small area and has a high function of preventing water and dust from entering the inside of the device housing 100, the PTFE porous body is porous. A quality membrane is used.

It can be exemplified that the average pore diameter of the pores formed in the ventilation membrane 10 is in the range of 0.01 μm or more and 100 μm or less. Within this range, the average pore diameter is preferably in the range of 0.1 μm or more and 50 μm or less, and more preferably in the range of 0.1 μm or more and 5 μm or less.

When the average pore diameter formed on the ventilation membrane 10 is less than 0.01 μm, it becomes difficult for air to pass through the ventilation membrane 10. On the other hand, when the average pore diameter of the ventilation membrane 10 exceeds 100 μm, liquids and solids easily enter the inside of the equipment housing 100 through the ventilation membrane 10.

The thickness of the ventilation membrane 10 is not particularly limited, but for example, it can be exemplified that it is in the range of 10 μm or more and 1000 μm or less.
If the thickness of the ventilation film 10 is excessively thin, the strength of the ventilation film 10 tends to decrease. On the other hand, if the thickness of the ventilation film 10 is excessively thick, the size of the ventilation member 1 tends to be large.

The surface of the breathable membrane 10 (particularly, the outer portion) may be subjected to a liquid repellent treatment such as a water repellent treatment or an oil repellent treatment. By applying the liquid repellent treatment to the ventilation film 10, adhesion of dirt and the like to the ventilation film 10 is suppressed. As a result, clogging of the ventilation membrane 10 is suppressed.
The liquid repellent treatment of the breathable membrane 10 includes, for example, a hydrocarbon group (perfluoroalkyl group) saturated with fluorine in the side chain and a compound whose main chain is acrylic, methacrylic, silicone or the like. This can be done by applying a liquid agent to the surface of the air-permeable membrane 10. The method of applying the liquid repellent to the surface of the ventilation film 10 is not particularly limited, and for example, gravure coating, spray coating, kiss coating, dipping and the like can be adopted.
The oil-repellent treatment is not particularly limited as long as it can form an oil-repellent film containing a polymer having a perfluoroalkyl group. Examples of the forming method include coating a polymer solution or dispersion having a perfluoroalkyl group by an air spray method, an electrostatic spray method, a dip coating method, a spin coating method, a roll coating method, a curtain flow coating method, an impregnation method, or the like. , A film forming method by an electrodeposition coating method or a plasma polymerization method can be exemplified.

<< Collection Membrane 20 >>
The collecting membrane 20 is a membrane formed in a disk shape. The outer diameter of the collecting membrane 20 is larger than the diameter of the first communication hole 331 described later and smaller than the diameter of the second communication hole 332.
The material of the collecting membrane 20 is particularly limited as long as it is a membrane that collects liquid suspended particles (for example, oil mist) and has a plurality of pores that allow gas to permeate in the state where the liquid suspended particles are collected. Not done. Collecting the liquid suspended particles means that the liquid suspended particles are absorbed inside the plurality of pores formed in the collecting membrane 20 so as not to permeate the collecting membrane 20.

FIG. 3 is a schematic view showing the curve ratio r.
From the viewpoint of collecting liquid suspended particles (for example, oil mist), the collecting membrane 20 divides the path length l of the gas or liquid suspended particles formed in the pores by the thickness d of the collecting membrane 20. It is desirable that the film does not have a portion where the bending ratio r (= l / d) is 1.
Since the path length l and the thickness d are the same in the portion where the curve ratio r is 1, it can be regarded as a straight through hole formed in the thickness direction. In a straight through hole having a curve ratio r of 1, it is considered that the liquid suspended particles proceed in the thickness direction through the straight through hole and easily pass through the membrane without colliding with the wall surface around the through hole. Be done.
Therefore, the fact that there is no portion where the curvature ratio r is 1 means that there is only a portion where the path length l is larger than the thickness d, so that the liquid suspended particles are present on the wall surface around the pores in the collection membrane 20. It becomes easy to collide. Then, the liquid suspended particles collide with the wall surface around the pores in the collecting film 20 and are collected by the collecting film 20, simulated, and coarsened. In other words, the film that does not have a portion where the curvature ratio r is 1 has a function of collecting, simulating, and coarsening the liquid suspended particles, and also has the function of coarsening the liquid suspended particles. Has a function of liquefying and returning the particles to the inside of the device housing 100 by its own weight.

Further, a liquid film is formed by adhering coarsened and liquefied liquid floating particles to the surface of the pores of the collection film 20. The liquid film absorbs liquid suspended particles. Since the liquid film is formed on the surface of the pores of the collecting film 20, the liquid suspended particles are absorbed by the liquid film and it becomes difficult to pass through the collecting film 20.
As described above, the collecting membrane 20 has a function of collecting, simulating, coarsening, liquefying, and returning the liquid suspended particles to the inside of the device housing 100 by its own weight at the initial stage of use. Further, the collecting film 20 has a function of absorbing the liquid floating particles in the liquid film at a stage after the liquefied liquid floating particles form the liquid film.

From the viewpoint of collecting liquid suspended particles, it is desirable that the pore size of the collecting film 20 is small. On the other hand, from the viewpoint of allowing the permeation of gas in the state where the liquid suspended particles are collected, it is desirable that the pore size of the collecting membrane 20 is large.
At the stage after the liquid film is formed, it is considered that the liquid escapes from the large pore diameter portion (thick and short pore portion) and becomes a gas flow path. On the other hand, in the small pore diameter portion (thin and long pore portion), although it is considered that the liquid falls due to its own weight, it is considered that the liquid film is still formed in order to newly absorb the liquid suspended particles.
As a result of diligent studies by the present inventors, the pore size of the collecting membrane 20 is preferably in the range of 1 μm or more and 400 μm or less, and the average pore diameter of the collecting membrane 20 is preferably in the range of 5 μm or more and 60 μm or less. I found. If the average pore diameter is less than 5 μm, the liquid film formed on the surface of the pores does not allow gas to pass through and clogging is likely to occur. When the average pore size exceeds 60 μm, it is considered that the liquid suspended particles easily pass through without colliding with the wall surface or the liquid film around the pores.
Further, the collecting membrane 20 allows the permeation of gas in a state where the floating liquid particles are collected, and the ventilation membrane 10 prevents the invasion of liquid and solid into the internal space of the equipment housing 100 and allows the permeation of gas. From the viewpoint of this, it is desirable that the pore size of the collecting membrane 20 is larger than the pore diameter of the ventilation membrane 10.

Further, from the viewpoint of collecting the liquid suspended particles and allowing the permeation of gas in the state where the liquid suspended particles are collected, the porosity of the collecting membrane 20 is in the range of 10% or more and 99% or less. Can be exemplified. As a result of diligent studies by the present inventors, it has been found that the porosity of the collecting membrane 20 is preferably in the range of 25% or more and 90% or less. If the porosity is too large, the liquid suspended particles will pass through and it will be difficult to collect them. If the porosity is too small, it will be difficult to allow gas to permeate in the state where the liquid suspended particles are collected. is there.

It can be exemplified that the collection membrane 20 is a porous body or foam of at least one of resin, ceramic and metal.
As the resin, it can be exemplified that it is an ultrahigh molecular weight resin from the viewpoint of sintering and the like. The ultra-high molecular weight resin is usually in the form of powder and may be used alone or in combination of two or more.
Examples of the ultra-high molecular weight resin include ultra high molecular weight polyethylene (hereinafter referred to as “UHMWPE”), ultra high molecular weight polypropylene, and ultra high molecular weight polyamide. The molecular weight (measured by the viscosity method) of an ultra-high molecular weight resin is much larger than that of a normal resin. For example, the molecular weight of ordinary polyethylene or polypropylene is about 100,000 or less, whereas the molecular weight of UHMWPE or ultra-high molecular weight polypropylene is about 500,000 or more. Further, while the molecular weight of ordinary polyamide is 5000 or less, the molecular weight of ultra-high molecular weight polyamide is about 40,000 or more.

It can be exemplified that the collecting membrane 20 according to the present embodiment is manufactured by using UHMWPE, for example, as follows. That is, first, UHMWPE powder is filled in a mold, heated at a temperature lower than the melting point of UHMWPE, and then pressure-compressed at a predetermined pressure to form a premolded product. Next, while the preformed product is placed in the mold, it is heated to a temperature equal to or higher than the melting point of UHMWPE and sintered to form a porous sintered body. Next, after taking out the produced porous sintered body from the mold, it is cut into a sheet having a predetermined thickness using a lathe or the like to obtain a porous sheet. A pair of smooth surfaces of a transfer base material such as a polyester film having a smooth surface are superposed on the sheet surface of the obtained porous sheet, and the surface is heated to a predetermined temperature (the melting point of UHMWPE or a temperature near the melting point). It is sandwiched between hot plates and allowed to elapse for a predetermined time. Then, the smooth surface of the transfer base material is thermally transferred to the sheet surface of the porous sheet, then cooled and taken out from between the hot plates. The porous sheet obtained as described above is cut into a sheet having a thickness of 0.03 to 3 mm by cutting with a lathe or the like to obtain a disk-shaped collecting film 20.
By manufacturing in this way, the thickness becomes uniform. Further, continuous pores are formed by sintering UHMWPE powder particles with each other, and high air permeability is provided.
Further, the porosity and the pore diameter of the collecting membrane 20 can be adjusted by adjusting the particle diameter of the UHMWPE powder and the degree of pressurization during sintering.

In the above-mentioned production method, after heating at a temperature lower than the melting point of UHMWPE, a premolded product is formed by pressurizing at a predetermined pressure, but it is not always necessary to go through this step. A mold filled with UHMWPE powder may be directly heated to a temperature equal to or higher than the melting point of UHMWPE and then sintered to obtain a porous body.
Further, in the above-mentioned manufacturing method, the smooth surface of the transfer base material is pressure-welded to the sheet surface of the porous sheet for thermal transfer. At that time, the porous sheet may be heated and softened in advance. ..
Further, the pressurization performed when the premolded product is formed is adjusted according to the air permeability of the target porous body, but is preferably 0.3 to 40 kg / cm ² .

Further, in the above-mentioned production method, it is preferable that the heating in the step of obtaining the porous sintered body is performed in the range of the melting point of UHMWPE to (melting point of UHMWPE + 50 ° C.).
Further, as the surface-smooth transfer substrate used for thermal transfer, a synthetic resin film, a mirror-surfaced metal whose metal surface is polished like a mirror surface, or the like can be used. Of these, it is preferable to use a synthetic resin film. The synthetic resin film is not particularly limited, but a polyester film or the like is preferable.
Further, the above-mentioned manufacturing method corresponds to the manufacturing method disclosed in Japanese Patent Application No. 7-333518 according to the application of the present applicant. Further, it may be manufactured by using the manufacturing method disclosed in Japanese Patent Application No. 2009-99962 according to the application of the present applicant.

The surface of the collecting film 20 may be subjected to a liquid repellent treatment such as a water repellent treatment or an oil repellent treatment. By applying the liquid repellent treatment to the collecting film 20, adhesion of dirt and the like to the collecting film 20 is suppressed. As a result, clogging of the collecting membrane 20 is suppressed. It can be exemplified that the liquid-repellent treatment and the oil-repellent treatment on the collecting membrane 20 are the same treatments as the liquid-repellent treatment and the oil-repellent treatment on the ventilation membrane 10 described above.

<< Holding member 30 >>
As shown in FIGS. 1 and 2, the holding member 30 has a cylindrical cylindrical portion 31 and an outer protruding portion 32 protruding outward from the cylindrical portion 31. The inside of the cylindrical portion 31 functions as a communication hole 33 that communicates the internal space and the external space of the device housing 100.
The cylindrical portion 31 has an inner protruding portion 34 protruding from the inner peripheral surface toward the center over the entire circumference. The communication hole 33 is composed of a first communication hole 331 formed inside the inner protrusion 34 and a second communication hole 332 formed on the outer space side of the first communication hole 331.

The holding member 30 holds the ventilation film 10 at the end 31a on the outer space side in the direction of the center line CL in the cylindrical portion 31 (hereinafter, may be referred to as “center line direction”). The ventilation film 10 covers the opening on the outer space side in the center line direction in the cylindrical portion 31. That is, the ventilation film 10 is fixed to the holding member 30 so as to close the second communication hole 332. The method of fixing the ventilation membrane 10 to the cylindrical portion 31 will be described in detail later.

The holding member 30 holds the collecting membrane 20 on the internal space side of the ventilation membrane 10. The holding member 30 holds the collecting membrane 20 at a position where the ventilation membrane 10 and the collecting membrane 20 do not come into contact with each other. More specifically, the holding member 30 holds the collecting film 20 at the end 34a on the outer space side in the center line direction of the inner protruding portion 34. The collecting membrane 20 is fixed to the holding member 30 so as to close the first communication hole 331. There is a second communication hole 332 through which gas flows in the gap between the ventilation membrane 10 and the collection membrane 20. The method of fixing the collecting membrane 20 to the cylindrical portion 31 will be described in detail later.

A chamfer 31c is formed at an inner portion of the cylindrical portion 31 on the side of the end portion 31b on the internal space side. Then, the holding member 30 is mounted on the device housing 100 by press-fitting the end 31b on the internal space side of the cylindrical portion 31 in the direction of the center line into the mounted portion 110 of the device housing 100. That is, the holding member 30 may fall off from the mounted portion 110 of the device housing 100 due to the contact pressure generated between the inner peripheral surface of the cylindrical portion 31 on the end portion 31b side on the internal space side and the device housing 100. It is suppressed.

The outer protruding portion 32 is a portion that protrudes outward from the outer peripheral surface 31d of the cylindrical portion 31. A plurality of outer protrusions 32 (four in the present embodiment) are formed at equal intervals in the circumferential direction. When the plurality of outer protrusions 32 are cut along a plane orthogonal to the center line CL, the outer peripheral surfaces 32a of the plurality of outer protrusions 32 are formed on substantially the same circle. The outer peripheral surface 32a of the outer protruding portion 32 is a surface substantially parallel to the center line direction. However, as shown in FIGS. 1 and 2, the end portion of the outer protruding portion 32 on the outer space side in the center line direction is larger than the center line CL as it goes from the outer space side in the center line direction to the inner space side. A chamfer 32b is formed in which the size gradually increases.

It can be exemplified that the material of the holding member 30 is a thermoplastic resin that is easy to mold. For example, polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polysulfone (PS), polypropylene (PP), polyethylene (PE), ABS resin, thermoplastic elastomer, or a composite material thereof can be exemplified. it can. Further, as the material of the holding member 30, in addition to the above-mentioned thermoplastic resin, a reinforcing material such as glass fiber or carbon fiber or a metal is compounded with the thermoplastic resin to improve heat resistance, dimensional stability, rigidity and the like. Composite materials may be used. Further, as the material of the holding member 30, a metal or a synthetic rubber such as NBR (nitrile rubber), EPDM (ethylene-propylene rubber), silicone rubber, fluorine rubber, acrylic rubber, or hydride nitrile rubber may be used.
The molding method of the holding member 30 is not particularly limited, and examples thereof include injection molding and cutting.

The surface of the holding member 30 (particularly, the outer portion) may be subjected to a liquid repellent treatment such as a water repellent treatment or an oil repellent treatment. By applying the liquid repellent treatment to the holding member 30, adhesion of dirt or the like to the holding member 30 is suppressed. It can be exemplified that the liquid repellent treatment and the oil repellent treatment on the holding member 30 are the same treatments as the liquid repellent treatment and the oil repellent treatment on the ventilation film 10 described above.

As a method of fixing the ventilation film 10 and the collection film 20 to the holding member 30, when the holding member 30 is a thermoplastic resin, heat welding such as iron welding, ultrasonic welding, laser welding or the like is preferable. Further, the ventilation film 10 and the collection film 20 may be fixed to the holding member 30 by using insert molding in which the resin is flowed while the ventilation film 10 and the collection film 20 are set in the mold.
The ventilation film 10 and the collection film 20 are the same as the internal space and the external space of the equipment housing 100 even if the ventilation film 10 and / or the collection film 20 is thickened or bent due to thermal expansion. Even if it bends under the pressure of the gas flowing between them, it is fixed in a position where it does not come into contact.

<< Cover member 40 >>
As shown in FIGS. 1 and 2, the cover member 40 has a cylindrical side wall portion 41 and a disk-shaped top portion 42 provided at an end portion of the side wall portion 41 on the external space side in the center line direction.
The size of the inner diameter of the side wall portion 41 is substantially the same as the size of the outer peripheral surface 32a of the outer protruding portion 32 of the holding member 30.
As shown in FIG. 2, a plurality of protrusions 43 protruding toward the internal space side (three in the present embodiment) are formed at equal intervals in the circumferential direction on the end surface of the top portion 42 on the internal space side in the center line direction. ing.

The cover member 40 is assembled so that a plurality of protrusions 43 formed on the top portion 42 come into contact with the ventilation membrane 10. In other words, the cover member 40 is pushed against the holding member 30 until the plurality of protrusions 43 of the cover member 40 abut on the ventilation film 10. Then, with the cover member 40 assembled, the inner peripheral surface of the side wall portion 41 of the cover member 40 comes into contact with the outer peripheral surface of the outer protruding portion 32 of the holding member 30, and the cover member 40 falls off from the holding member 30. Is suppressed.

Then, as shown in FIG. 2, in a state where the protrusion 43 of the cover member 40 and the ventilation film 10 are in contact with each other, the communication hole 33 formed in the holding member 30, between the top 42 of the cover member 40 and the ventilation film 10. The gap between the inner peripheral surface of the side wall portion 41 of the cover member 40 and the outer peripheral surface of the cylindrical portion 31 of the holding member 30 is such that the gas is between the internal space and the external space of the equipment housing 100. It functions as a circulating air passage F.

<< Action / effect of ventilation member 1 >>
In the ventilation member 1 configured as described above, when heat is generated due to friction or the like caused by the operation of the drive mechanism in the device housing 100, the air in the device housing 100 expands. Then, when the pressure in the internal space of the device housing 100 becomes larger than the pressure in the external space of the device housing 100 due to the expanded air, the air in the device housing 100 passes through the ventilation member 1 through the device housing 100. It is released into the external space of the body 100.

Further, in the ventilation member 1 configured as described above, when the air in the equipment housing 100 is discharged to the external space of the equipment housing 100, the ventilation member 1 is provided closer to the internal space side of the equipment housing 100 than the ventilation film 10. The collected collecting film 20 collects liquid suspended particles (for example, oil mist) from the internal space of the device housing 100 toward the external space of the device housing 100. Therefore, in the ventilation member 1 according to the present embodiment, it is suppressed that the liquid suspended particles reach the ventilation membrane 10 when the air in the equipment housing 100 is discharged to the external space of the equipment housing 100. Even if the liquid floating particles permeate the collecting membrane 20, it is difficult for the liquid floating particles to reach the ventilation membrane 10 because there is a space between the collecting membrane 20 and the ventilation membrane 10. Further, since the ventilation membrane 10 is not in contact with the collection membrane 20 that collects the liquid suspended particles, the liquid suspended particles collected by the collection membrane 20 are suppressed from directly moving to the ventilation membrane 10. .. As a result, clogging of the ventilation membrane 10 due to the liquid floating particles reaching the ventilation membrane 10 and the ventilation membrane 10 collecting the liquid suspension particles is suppressed.

On the other hand, when the operation of the drive mechanism in the device housing 100 is stopped, the air in the device housing 100 contracts. Then, the pressure in the internal space of the device housing 100 becomes a negative pressure with respect to the pressure in the external space of the device housing 100, and the air in the external space of the device housing 100 passes through the ventilation member 1 to the device housing 100. Is drawn into the interior space of.
When the ventilation film 10 of the ventilation member 1 guides the air in the external space of the equipment housing 100 to the internal space of the equipment housing 100, liquids and solids flow from the external space of the equipment housing 100 to the internal space of the equipment housing 100. Prevent intrusion. Therefore, the ventilation member 1 prevents water, dust, and the like from entering the internal space of the device housing 100. Further, when the air in the external space of the device housing 100 is guided to the internal space of the device housing 100, the collected liquid floating particles and the coarsened and liquefied liquid floating particles fall off from the collecting film 20. In addition, the liquid adhering to the collecting film 20 falls under its own weight. As a result, a gas flow path in the collecting membrane 20 is secured. That is, since the collecting membrane 20 allows the permeation of gas while collecting the liquid suspended particles, the collecting membrane 20 is clogged due to the collecting of the liquid suspended particles. Is suppressed.

[test]
Subsequently, the operation of the ventilation member 1 will be described in more detail with reference to an experimental example.
FIG. 4A is a schematic view of the experimental device 200. FIG. 4B is an enlarged view of the IVb portion of FIG. 4A.
FIG. 5 is a diagram showing the appearance results of oil adhesion to the first film when the second film is different.
FIG. 6 is a diagram showing the results of ventilation performance of the first membrane when the second membrane is different.

The ATI oil mist generator (aerosol generator) (product number "TDA-4B"), which is the experimental device 200, was filled with Toyota genuine ATF autofluid type T-IV manufactured by Toyota Motor Corporation. After that, the inlet side was connected to the airline and the air pressure of the regulator was set to 5 psi (175 kPa). Further, after connecting to a jig provided with a vent portion 210 on the outlet side, a flow meter 220 manufactured by STEC (part number "SEF-51") was connected.

The vent portion can be inserted up to two membranes.
As shown in FIG. 5, in the experimental example, the first membrane 211 is a PTFE porous membrane, the second membrane 212 is a UHMWPE porous membrane, the thickness is 0.2 mm, the average pore diameter is 17 μm, and the porosity is 30%. It is a membrane. In the comparative example, only the first membrane 211 of the PTFE porous membrane is inserted, and the second membrane 212 is not inserted.
Both the first film 211 and the second film 212 are punched out to have a diameter of 47 mm and inserted into the vent portion 210.
Various dimensions such as the distance between the first film 211 and the second film 212 are as shown in FIG.

[Experimental result]
FIG. 5 is a result of visually confirming the appearance of the determination result regarding the oil adhesion to the first film 211.
As shown in FIG. 5, in the comparative example in which the second film 212 is not provided, the first film 212 is provided on the upstream side of the first film 211 as compared with the case where the second film 212 of the UHMWPE porous film is provided. It was confirmed that a large amount of oil was attached to the film 211. When the second film 212 of the UHMWPE porous film is provided as in the experimental example, the amount of oil adhering to the first film 211 is small because the second film 212 collects the oil mist. After conducting the test for 30 minutes, the air permeability of the first membrane 211 was measured according to JIS P 8117. As shown in FIG. 5, it is clear that the air volume is reduced in the comparative example.

<Modification example 1>
FIG. 6A is a schematic configuration diagram of the ventilation member 300 according to the first modification. FIG. 6B is a cross-sectional view of the VIb-VIb portion of FIG. 6A.
The ventilation member 300 according to the first modification is a holding member 330 that holds the ventilation membrane 310, the collection membrane 320, and the ventilation membrane 310 and the collection membrane 320 so that the ventilation membrane 310 and the collection membrane 320 do not come into contact with each other. And have.

The ventilation membrane 310 and the collection membrane 320 are the same as the ventilation membrane 10 and the collection membrane 20 described above, respectively. However, the ventilation membrane 310 and the collection membrane 320 are formed so that the outer diameters are substantially the same.
The holding member 330 is a thin, donut-shaped member that holds the ventilation membrane 310 on one surface and the collection membrane 320 on the other surface. It can be exemplified that the holding member 330 is, for example, a double-sided tape.

The ventilation member 300 according to the first modification is mounted on the equipment housing 100 so that the collection film 320 is on the internal space side of the equipment housing 100 and the ventilation membrane 310 is on the external space side of the equipment housing 100. For example, it is illustrated that the ventilation member 300 according to the first modification is adhered to the opening of the mounted portion 110 of the device housing 100 and the opening of the hose or tube mounted on the mounted portion 110. Can be done. Alternatively, it may be attached to the opening of the mounted portion 110 of the device housing 100 or the opening of the hose or tube mounted on the mounted portion 110 via a member that supports the ventilation member 300 according to the first modification. Can be exemplified.

The thickness of the holding member 330 increases or bends due to thermal expansion due to heat generated by the ventilation membrane 310 and / or the collection membrane 320 due to friction caused by the operation of the drive mechanism in the equipment housing 100. Even if it does, even if it bends due to the pressure of the gas flowing between the internal space and the external space of the equipment housing 100, it is determined that the ventilation membrane 310 and the collection membrane 320 do not come into contact with each other. ing.

The ventilation member 300 according to the modified example 1 configured as described above can also exhibit the same action and effect as the ventilation member 1 according to the above-described embodiment.

<Modification 2>
In the ventilation member 1 according to the above-described embodiment and the ventilation member 300 according to the modification 1, the liquid is present in the opening of the equipment housing 100 that houses the liquid in the internal space (liquid suspended particles are present). The collecting films 20 and 320 are arranged on the internal space side (generated), and the ventilation films 10 and 310 are arranged on the external space side, but the present invention is not particularly limited. When the ventilation members 1, 300 are mounted on the housing in which the liquid exists on the external space side, the collecting films 20 and 320 are placed on the external space side where the liquid exists (many liquid floating particles are generated) in the internal space. It is preferable to arrange the ventilation films 10, 310 on the side.

FIG. 7 is a cross-sectional view of the ventilation member 400 according to the second modification.
The ventilation member 400 according to the second modification is a holding member 430 that holds the ventilation membrane 410, the collection membrane 420, and the ventilation membrane 410 and the collection membrane 420 so that the ventilation membrane 410 and the collection membrane 420 do not come into contact with each other. And have.

The shape and material of the holding member 430 are the same as the shape and material of the holding member 30 of the ventilation member 1 according to the above-described embodiment.
However, the holding member 430 holds the ventilation film 410 at the end 34a on the outer space side in the center line direction of the inner protruding portion 34. The ventilation film 410 is fixed to the holding member 430 so as to close the first communication hole 331. Further, the holding member 430 holds the collecting film 420 at the end portion 31a on the external space side of the cylindrical portion 31. The collecting membrane 420 covers the opening on the outer space side in the center line direction in the cylindrical portion 31. That is, the collecting membrane 420 is fixed to the holding member 430 so as to close the second communication hole 332. Then, in the gap between the ventilation membrane 410 and the collection membrane 420, there is a second communication hole 332 through which gas flows. The method for fixing the ventilation membrane 410 and the collection membrane 420 to the holding member 430 is as described above.

The ventilation membrane 410 and the collection membrane 420 are the same as the ventilation membrane 10 and the collection membrane 20 described above, respectively. However, the outer diameter of the collecting membrane 420 is formed to be larger than the outer diameter of the ventilation membrane 410.

The ventilation member 400 according to the second modification is attached to the opening of the equipment housing 100 in which there are more liquids and liquid suspended particles in the outer space than in the inner space. Further, the ventilation member 400 according to the second modification may be attached to the tip of a hose or a tube attached to the attached portion 110 of the equipment housing 100 having the liquid and the liquid floating particles in the external space. That is, in the ventilation member 400 according to the second modification, the equipment housing 100 or the equipment housing is such that the collection film 420 is on the external space side of the equipment housing 100 and the ventilation membrane 410 is on the internal space side of the equipment housing 100. It is attached to the tip of a hose or tube attached to the attached portion 110 of 100.

In the ventilation member 400 according to the second modification configured as described above, the pressure in the external space of the equipment housing 100 is relative to the pressure in the internal space of the equipment housing 100 due to the expanded air outside the equipment housing 100. When it becomes large, the air outside the device housing 100 is drawn into the internal space of the device housing 100 via the ventilation member 400.
Further, in the ventilation member 400 according to the modified example 2 configured as described above, when the air outside the equipment housing 100 is drawn into the internal space of the equipment housing 100, the equipment housing 100 is more than the ventilation film 410. The collecting film 420 provided on the external space side collects liquid suspended particles (for example, oil mist) from the external space of the equipment housing 100 toward the internal space of the equipment housing 100. Therefore, in the ventilation member 400 according to the second modification, the liquid suspended particles are suppressed from reaching the ventilation membrane 410 when the air outside the equipment housing 100 is drawn into the internal space of the equipment housing 100. Even if the liquid suspended particles permeate the collecting membrane 420, it is difficult for the liquid suspended particles to reach the ventilation membrane 410 because there is a space between the collecting membrane 420 and the ventilation membrane 410. Further, since the ventilation membrane 410 is not in contact with the collection membrane 420 that collects the liquid suspended particles, it is suppressed that the liquid suspended particles collected by the collection membrane 420 move directly to the ventilation membrane 410. .. Further, by mounting the collecting membrane 420 so as to be lower than the ventilation membrane 410, the liquid collected by the collecting membrane 420 falls off to the external space side by its own weight. As a result, it is possible to prevent the air-permeable membrane 410 from being clogged due to the liquid suspended particles reaching the air-permeable membrane 410 and the air-permeable membrane 410 collecting the liquid suspended particles.

1,300,400 ... Ventilation member, 10,310,410 ... Ventilation membrane, 20,320,420 ... Collection membrane, 30,430 ... Holding member, 31 ... Cylindrical part, 32 ... Outer protrusion, 40 ... Cover Member, 100 ... Equipment housing, 110 ... Mounted part

Claims (5)

A first porous body that blocks the ingress of liquids and solids and has a plurality of pores through which gas permeates.
A number of holes are formed that allow the liquid and the floating liquid particles to be collected and the gas to permeate in the collected state of the floating liquid particles, and have a function of liquefying the floating liquid particles and dropping them by their own weight. A second porous body which is a two-porous body and is arranged so that a gas permeates through a gap between the first porous body and the first porous body without contacting the first porous body.
A mounting member that is mounted on an opening of a housing containing liquids and liquid floating particles or a member attached to the housing and has a communication hole that communicates between the internal space and the external space of the housing. Prepare,
The first porous body is held by the mounting member so as to cover the opening on the external space side of the communication hole.
The second porous body is a ventilation member characterized in that the second porous body is held by the mounting member on the internal space side of the first porous body. The ventilation member according to claim 1, wherein the second porous body is a membrane in which a portion having a curvature ratio of 1 obtained by dividing the gas path length by the thickness does not exist. The ventilation member according to claim 1 or 2, wherein the pore diameter of the second porous body is larger than the pore diameter of the first porous body. The ventilation member according to any one of claims 1 to 3, wherein the second porous body is at least one porous body or foam of resin, ceramic and metal. A drive device that operates smoothly due to the presence of liquid and liquid suspended particles and generates heat by operating is housed in the housing.
The ventilation member according to any one of claims 1 to 4, wherein the second porous body does not come into contact with the first porous body even when the driving device is operating.

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