Patent ID: 12234162

DESCRIPTION OF EMBODIMENTS

A. First Embodiment

A first embodiment of a water purification cartridge according to the present invention will be described below with reference to the diagrams.FIG.1is an external perspective view of a water purification cartridge (which may be hereinafter referred to simply as a cartridge)1according to the present embodiment, andFIG.3Ais a front view ofFIG.1. In the following, for convenience of description, the vertical direction inFIG.3Ais referred to as “above (up, upper etc.)/below (down, lower etc.)”, the left-right direction inFIG.3Ais referred to as “left/right” or “horizontal”, and the paper plane direction inFIG.3Ais referred to as “front/back”, and the description is given based on these directions.

<1. Summary of Water Purification Cartridge>

The cartridge1is mainly used in a pot-type (server-type) water purifier in which raw water passes through the cartridge1due to the weight of the raw water.FIG.13Ashows an example of the water purifier. As shown inFIG.13A, this water purifier100includes a housing101that has an opening S1in an upper portion. The housing101contains a tank102, which is open in an upper portion. The tank102is a portion for storing raw water, and raw water can be poured into the tank102through an upper opening S2. An opening S4is formed in a bottom portion of the tank102, and the cartridge1is attached together with a packing104so as to seal a peripheral portion of the opening S4. Raw water in the tank102flows into the cartridge1. Note that since the opening S2is formed to be smaller than the opening S1, the opening S1is divided into the opening S2and an opening S3.

After passing through the inside of the cartridge1, raw water flows out, as purified water, from a lower side of the cartridge1, and is stored in a server space103below the tank102. The opening S3functions as an outlet for taking out purified water from the server space103.

As shown inFIGS.1to4, the cartridge1according to the present embodiment has a tubular shape as a whole, and typically has a substantially cylindrical shape. The cartridge1includes a casing2and a filter member3that has a substantially cylindrical shape that is accommodated within the casing2. The cartridge1of the present embodiment is an in-out type cartridge in which raw water that has flowed into a hollow portion of the filter member3passes through the filter member3outward in the radial direction, and flows out, as purified water, into a space between an outer circumferential face320of the filter member3and a side wall portion of the casing2.

The filter member3is a member for filtering raw water and make the raw water into purified water. As shown inFIG.2, the filter member3has, at the center, a hollow portion34that has a substantially circular shape as viewed from above, and has a first face31and a second face33at respective ends in the axial direction. The filter member3further has a side circumferential portion32that is continuous with the first face31and the second face33and extends in the axial direction. The filter member3is accommodated in the casing2in an orientation in which the first face31faces upward and the second face33faces downward. This state is referred to as an accommodated state. The outer diameter of the filter member3is smaller than the inner diameter of the side wall portion21of the casing2. Thus, in the accommodated state, an annular space230is formed between the outer circumferential face320of the filter member3and the side wall portion21of the casing2, as shown inFIG.4.

<2. Casing>

The casing2includes a first cover portion that covers the first face31of the filter member3, a second cover portion that covers the second face33of the filter member3, and a side wall portion that covers the outer circumferential face320of the filter member3. As shown inFIG.2, the casing2of the present embodiment is constituted by a first cover portion20that covers the first face31of the filter member3and the second cover portion22that covers the second face33of the filter member3, and the first cover portion20and the second cover portion22are connected to each other so as to be able to, or not able to, be detached from each other, as will be described later. The side wall portion21is constituted by a side wall portion200of the first cover portion20and a side wall portion220of the second cover portion22that will be described later. In the following, a state where the first cover portion20and the second cover portion22are connected is referred to as a connected state. In the connected state, a space for accommodating the filter member3is formed within the casing2.

The first cover portion20has the side wall portion200that has a substantially cylindrical shape, and an inflow portion207that is surrounded by the side wall portion200. The inflow portion207is a portion that puts the inside and the outside of the cartridge1in communication with each other. That is to say, in the state shown inFIG.13A, raw water in the tank102flows into the cartridge1via the inflow portion207. As shown inFIG.4, the inflow portion207has a face203that is continuous from the side wall portion200and formed to have a flat-bottomed container shape that is recessed downward, and opposes the internal space in the casing2. A circular open hole207afor raw water to flow into the cartridge1is formed at the center of the face203. In the accommodated state, the hollow portion34of the filter member3is located generally immediately below the open hole207a, and raw water flows from the open hole207ainto the hollow portion34of the filter member3. The face203of the first face cover portion in the accommodated state can come into intimate contact with the first face31of the filter member3. Particularly, in the water purification cartridge according to the present invention, the filter member3is accommodated within the casing2in a state where the filter member3is elastically deformed by pressing force of a first contact portion of the first cover portion20and a second contact portion of the second cover portion22, as will be described later. With this configuration, raw water that has flowed into the hollow portion34of the filter member3can be prevented from passing through a gap between the first face31and the first cover portion20and a gap between the second face33and the second cover portion22, and the passage of raw water through the filter member3can be promoted, without an elastic member being provided between a molded water purification material and a casing and lid as in the water purification cartridge described in Patent Literature 1.

The side wall portion200is formed so as to extend in the vertical direction from a position at which the face203is formed. A flange204for attaching the cartridge1to a peripheral portion of the opening S4is formed at a portion on the outer side of the side wall portion200and above the open hole207a. A groove210that extends in the circumferential direction is formed at the center in the vertical direction of the flange204. The groove210is a portion to which the packing104for sealing a gap between the cartridge1and the peripheral portion of the opening S4is fitted when the cartridge1is attached to the peripheral portion of the opening S4.

Vents205are formed at a position below the flange204of the side wall portion200and above the face203. The inside and the outside of the casing2are in communication with each other through the vents205. When raw water flows into the cartridge1, air in the cartridge1(casing2) is discharged via the vents205, allowing water passing through the cartridge1to move more smoothly. The vents205are arranged so as to be located within the server space103in a state where the cartridge1is attached to the peripheral portion of the opening S4and to be located above the first face31of the filter member3.

As shown inFIG.2, a thin region R, in which the thickness of the side wall portion200is smaller than that in the other portion, is formed at a position on the outer side of the side wall portion200and below the vents205. A plurality of claw portions206, each of which protrudes outward in the radial direction and has a substantially rectangular shape, are formed at intervals in the circumferential direction in the thin region R. The claw portions206enable the first cover portion20and the second cover portion22to be connected to each other by engaging with later-described window portions222of the second cover portion22. Note that the connecting means using the claw portions206and the window portions222has been described merely as an example of a means for connecting the first cover portion20and the second cover portion to each other, and the connecting means is not specifically limited thereto. Another example may be connection using welding or adhesion, or connection using screw fitting, for example.

As shown inFIG.4, a first protrusion208, which protrudes from the face203toward the internal space of the casing2and has an annular shape, is formed in the face203of the first cover portion20. In the accommodated state, the first protrusion208annularly comes into contact with the first face31of the filter member so as to surround the hollow portion34of the filter member3, and presses the filter member3in the axial direction to elastically deform the filter member3. In this case, the first protrusion208serves as the first contact portion that annularly comes into contact with the first face31of the filter member3so as to surround the outer circumferential face of the hollow portion34, and presses the filter member3in the axial direction to elastically deform the filter member3. In the water purification cartridge of the present invention, the face203may alternatively be a face that does not have a protrusion. For example, the face203may be flat. In this case, the face203serves as the first contact portion that annularly comes into contact with the first face31of the filter member3so as to surround the outer circumference of the hollow portion34, and presses the filter member3in the axial direction to elastically deform the filter member3. The cross-sectional shape of the first protrusion208is not specifically limited, but may be a substantially triangular shape, a substantially rectangular shape, a substantially semicircular shape, a substantially semi-oval shape, or the like. Corners of the substantially triangular shape and the substantially rectangular shape may be rounded.

The second cover portion22has a bottom portion227and a side wall portion220that continuously rises from the bottom portion227, and has a substantially cylindrical external appearance as a whole. As shown inFIG.3D, a plurality of open holes223afor purified water to be discharged to the outside of the cartridge1are formed at intervals in the circumferential direction in a peripheral portion of the bottom portion227. The plurality of open holes223aare collectively referred to as an outflow portion223. As shown inFIG.4, in the accommodated state, the open holes223aare formed so as to be located generally immediately below the space230between the outer circumferential face320of the filter member3and the side wall portion21of the casing2.

As shown inFIG.4, a face221of the second cover portion22in the accommodated state can come into contact with the second face33of the filter member3. Particularly, in the water purification cartridge according to the present invention, the filter member3is accommodated within the casing2in a state where the filter member3is elastically deformed by a pressing force of the first contact portion and the second contact portion, as will be described later, and thus, raw water that has flowed into the hollow portion34of the filter member3can be prevented from passing through a gap between the first face31and the first cover portion20and a gap between the second face33and the second cover22, and the passage of raw water through the filter member3can be promoted, without an elastic member being provided between a molded water purification material and a casing and lid as in Patent Literature 1. Here, the face221is a face of the bottom portion227that opposes the internal space of the casing2. A second protrusion224, which protrudes from the face221toward the internal space of the casing2and has an annular shape, is formed in the face221. In the accommodated state, the second protrusion224annularly comes into contact with the second face33of the filter member3so as to surround the circumference of the hollow portion34of the filter member3, and presses the filter member3in the axial direction to elastically deform the filter member3. In this case, the second protrusion224serves as the second contact portion that annularly comes into contact with the second face33of the filter member3so as to surround the circumference of the hollow portion34, and presses the filter member3in the axial direction to elastically deform the filter member3. In the water purification cartridge of the present invention, the face221may alternatively be a face that does not have a protrusion. For example, the face221may be flat. In this case, the face221serves as the second contact portion that annularly comes into contact with the second face33of the filter member3so as to surround the circumference of the hollow portion34, and presses the filter member3in the axial direction to elastically deform the filter member3. The cross-sectional shape of the second protrusion224is not specifically limited, but may be a substantially triangular shape, a substantially rectangular shape, a substantially semicircular shape, a substantially semi-oval shape, or the like. Corners of the substantially triangular shape and the substantially rectangular shape may be rounded.

The side wall portion220is formed to have a substantially cylindrical shape with generally the same diameter as that of the side wall portion200of the first cover portion20. In an upper portion of the side wall portion220, the same number of window portions222, each of which is a substantially rectangular opening, as the claw portions206are formed at positions in the circumferential position that correspond to the claw portions206. With this configuration, when the thin region R is inserted into the second cover portion22from above the second cover portion22, and the claw portions206and the window portions222are engaged with each other in one-to-one correspondence, a connected state in which the first cover portion20and the second cover portion22are connected to each other can be achieved. In the connected state, the side wall portion200and the side wall portion220are generally flush with each other, and form the side wall portion21of the casing2. Note that the second cover portion22can be removed from the first cover portion20by disengaging the window portions222and the claw portions206from each other. That is to say, the first cover portion20and the second cover portion22can be detachably connected to each other, and can also be connected to each other in an undetachable manner.

The material of the first cover portion20may be plastic. This plastic may be ABS resin (acrylonitrile butadiene styrene), PE (polyethylene), PP (polypropylene), AS resin (acrylonitrile styrene), PS (polystyrene), PET (polyethylene terephthalate), or PLA (polylactic acid) resin. Moe specifically, this plastic is selected from a group consisting of PP (polypropylene) and ABS resin (acrylonitrile butadiene styrene). The hardness of the first cover portion20is 95 to 100, which is higher than the later-described hardness of the filter member3. Note that the hardness of ABS resin is 95, the hardness of PP is 100, and the hardness of PET is 97.

The material of the second cover portion22may be plastic. This plastic may be ABS resin (acrylonitrile butadiene styrene), PE (polyethylene), PP (polypropylene), AS resin (acrylonitrile styrene), PS (polystyrene), PET (polyethylene terephthalate), or PLA (polylactic acid) resin. More specifically, this plastic is selected from a group consisting of PP (polypropylene) and ABS resin (acrylonitrile butadiene styrene). The hardness of the second cover portion22is 95 to 100, which is higher than the later-described hardness of the filter member3. Note that the hardness of ABS resin is 95, the hardness of PP is 100, and the hardness of PET is 97.

If the hardness of the first cover portion20is higher than the hardness of the filter member3, and the hardness of the second cover portion22is higher than the hardness of the filter member3, the first cover portion20and the second cover portion22may be made of the same material, or may be made of different materials. Note that measurement of the hardness in the present specification is conducted with a measurement device that is a hardness meter GS701G manufactured by TECLOCK using a method provided in JIS S 6050 “Plastic erasers”, and an average value at N=5 is regarded as the hardness.

FIG.5Ais a right side view of the casing2, andFIG.5Bis a cross-sectional view ofFIG.5Ataken along a line B-B.FIG.5Cis a right side view of the casing2, andFIG.5Dis a cross-sectional view ofFIG.5Ctaken along a line D-D. As illustrated inFIG.5, at least one of the first cover portion20and the second cover portion22may have, on the inner wall face, ribs240or241for positioning the filter member3. As shown inFIG.5B, the ribs240that protrude toward the internal space of the casing2and extend in the vertical direction (the axial direction of the filter member3) are formed on the inner wall face of the first cover portion20. As shown inFIG.5D, four ribs240are formed on the inner wall face of the first cover portion20and are arranged at generally equal intervals in the circumferential direction. Note that the ribs240shown inFIGS.5B and5Dare merely an example. The positions at which the ribs240are formed, the shape of each rib240, the number of ribs240, and so on, are not limited to the mode shown inFIGS.5B and5Dand can be changed as appropriate.

FIG.5Eis a right side view of the casing2, andFIG.5Fis a cross-sectional view ofFIG.5Etaken along a line F-F. As shown inFIG.5B, the ribs241that protrude toward the internal space of the casing2and extend in the vertical direction (the axial direction of the filter member3) are formed on the inner wall face of the second cover portion22. As shown inFIG.5F, four ribs241are formed on the inner wall face of the second cover portion22and are arranged at generally equal intervals in the circumferential direction.FIG.5Gis a cross-sectional view ofFIG.5Etaken along in a line F-F in the accommodated state. As shown inFIG.5G, the ribs241positions the filter member3such that the center of the filter member3is generally aligned with the center of the casing2in the accommodated state. Note that the ribs241shown inFIGS.5B and5Fare merely an example. The positions at which the ribs241are formed, the shape of each rib241, the number of ribs241and so on, are not limited to the mode shown inFIGS.5B and5Fand can be changed as appropriate.

In the accommodated state, the ribs240and241position the filter member3such that the space230is formed between the outer circumferential face320of the filter member3and the side wall portion of the casing2, and such that the center axis of the filter member3is generally aligned with the center axis of the casing2. As a result of the filter member3being thus positioned at an appropriate position with respect to the casing2, the relative positions of the hollow portion34, the inflow portion207, and the outflow portion223are appropriately maintained, and the space230for purified water is appropriate secured. With this configuration, water uniformly moves within the cartridge1, and thus the efficiency of water purification is maintained.

The casing2may further have a first resisting portion that serves as a resistance against a flow of purified water that has flowed out to the space230, between the outer circumferential face320of the filter member3and the outflow portion223. The first resisting portion stops the flow of purified water that has flowed out of the filter member3when the pressure of the purified water flowing out of the filter member3weakens to some extent. As a result, purified water can be prevented from becoming droplets and dropping from the outflow portion223.

FIG.7shows an example of the first resisting portion. In the example shown inFIG.7, a plurality of openings223b, which constitutes the outflow portion223, are formed at intervals in the circumferential direction at a lower portion of the second cover portion22. The openings223bare open laterally and downward of the second cover portion22. Ribs250, which protrude upward from the face221, are formed in correspondence with the positions in the circumferential direction of the openings223b, at a peripheral portion of the bottom portion227.

FIG.8is an enlarged cross-sectional view of an area around a rib250. As shown inFIG.8, each rib250is located outward, in the radial direction, of the outer circumferential face320of the filter member3, and is configured to close a lower portion of the corresponding opening223bfrom the inner side thereof in the radial direction. Thus, each rib250functions as the first resisting portion.

The maximum height of the ribs250based on the face221of the bottom portion227that serves as a reference can be set as appropriate in accordance with the filtering capacity of the filter member3, for example. The maximum height of the ribs250is preferably a height that does not affect at all, or hardly affects, the overall flow of water if the pressure of purified water is greater than or equal to a certain pressure, and with which an outflow of purified water can be stopped if the pressure of the purified water is such that the purified water drips from the outflow portion223.

Furthermore, a plurality of ribs250may be formed in the circumferential direction of the casing2to also serve as ribs for positioning the filter member3. That is to say, the ribs250may also have the function of at least either the ribs240or the ribs241for positioning the filter member3, and thus the ribs240or the ribs241may be omitted.

<3. Filter Member>

As mentioned above, the filter member3is a member for filtering raw water that has flowed into the hollow portion34by letting the raw water pass through the side circumferential portion32outward in the radial direction and making the raw water into purified water. The filter member3has the first face31and the second face33at respective ends in the axial direction. The filter member3is made of an elastic material. For this reason, the filter member3can come into intimate contact with harder objects, such as the first cover portion20and the second cover portion22.

A distance L1(seeFIG.2) between the first face31and the second face33in a state before the filter member3is accommodated in the casing (i.e., in a state before the filter member3is pressed in the axial direction and elastically deformed) is longer than a distance L3between a leading end portion209of the first protrusion208and a leading end portion225of the second protrusion224in the connected state (i.e., the distance L3between the first contact portion and the second contact portion; seeFIG.4). Thus, at the first face31of the filter member3in the accommodated state, the first protrusion208pierces and engages with a region outward, in the radial direction, of the hollow portion34, a force that compresses the filter member3in the axial direction is applied to the filter member3, and a gap between the first face31and the face203of the first cover portion20is shut. Similarly, in the second face33of the filter member3in the accommodated state, the second protrusion224pierces and engages with a region outward, in the radial direction, of the hollow portion34, a force that compresses the filter member3in the axial direction is applied to the filter member3, and a gap between the second face33and the face221of the second cover portion22is shut. With this configuration, the passage of water via the two end faces of the filter member3is suppressed, and raw water in the hollow portion34and purified water in the space230are separated from each other.

That is to say, the first protrusion208, which is the first contact portion, annularly comes into contact with the first face31of the filter member3so as to surround the outer circumferential face of the hollow portion34and presses the filter member3in the axial direction to elastically deform the filter member3, and the second protrusion224, which is the second contact portion, annularly comes into contact with the second face33of the filter member3so as to surround the circumference of the hollow portion34and presses the filter member3in the axial direction to elastically deform the filter member3. With this configuration, it is possible to prevent raw water that has flowed into the hollow portion of the filter member from passing through a gap between the first face31and the first cover portion and a gap between the second face33and the second cover portion, and to promote the passage of raw water through the filter member3, without an elastic member being provided between a molded water purification material and a casing and lid as in the water purification cartridge described in Patent Literature 1.

The compression ratio (L3/L1×100(%)) of the length L1of the filter member3between the contact portions in the accommodated state is preferably 98% or less, more preferably 96 to 98%, and more preferably 97 to 98%. When the compression ratio (L3/L1×100(%)) of the filter member3in the accommodated state is in the above range, the proportion (L2/L1×100(%)) of the distance L2to the length L1of the filter member3is, for example, 98% or more, preferably 98 to 101%, and more preferably 99 to 101%, from the viewpoint of reducing the area of contact portions and readily increasing the pressure that presses the filter member3in the axial direction and elastically deforms the filter member3in the accommodated state.

From the viewpoint of more reliably blocking the passage of water, it is preferable that a sealant is applied to at least one of the first face31of the filter member and the second face33of the filter member. It is more preferable that a sealant is applied to both the first face31and the second face33of the filter member. In the present embodiment, a hot melt adhesive is applied as a sealant to the first face31and the second face33. The main component of the hot melt adhesive is, for example, ethylene vinyl acetate (EVA), olefin, rubber, or the like. The application thickness of the sealant is 10 μm to 1000 μm, and the amount of sealant is 1 to 100 (mg/cm2), for example. Note that the sealant can be applied in advance and solidified before the filter member3is accommodated in the casing2.

Main streams of water that passes within the cartridge1are indicated by arrows shown inFIG.6. At first, raw water flows into the cartridge1via the inflow portion207of the first cover portion20. The raw water that flows into the cartridge1flows into the hollow portion34and is temporarily stored. Here, the first protrusion208and the second protrusion224engage, respectively, with an upper peripheral edge and a lower peripheral edge of the hollow portion34, and presses the filter member3in the axial direction to elastically deform the filter member3. For this reason, the raw water does not flow out to the space230via the first face31and the second face33. The raw water stored in the hollow portion34passes outward in the radial direction through the side circumferential portion32, and flows out, as purified water, to the space230. Subsequently, the purified water is discharged from the space230to the outside of the cartridge1via the outflow portion223.

The filter member3is made of a material that contains fibrous activated carbon, and is elastic. The hardness of the filter member3is lower than the hardness of the casing2, that is, the hardness of the first cover portion20and the hardness of the second cover portion22. The hardness of the filter member3is preferably 86 or less, and more preferably about 65 to 80. Note that the hardness measurement is conducted using the method provided in JIS S 6050 “Plastic erasers”, and an average value at N=5 is regarded as the hardness.

<4. Method for Manufacturing Filter Member>

In the present embodiment, the filter member3is manufactured from a sheet300, which is made of a mixture of fibrous activated carbon and thermally bonded fiber. As shown inFIG.12, the sheet300is wound around a core301until a predetermined thickness is reached. As a result of the core301around which the sheet300is wound being put into a furnace and heat-treated, the laminated sheet layers are integrated with each other, and a cylindrical intermediate molded body302wound around the core301is formed. The filter member3can be obtained by removing this intermediate molded body302from the core301and cutting the intermediate molded body302at a predetermined length. Here, the aforementioned hot melt adhesive may be applied to at least one of the first face31and the second face33of the filter member3obtained by cutting the intermediate molded body302.

The thermally bonded fiber contained in the sheet300is preferably thermally bonded fiber that is made of polymers of two or more components with different melting points or softening points. Particularly, it is preferable to use fiber that has a core sheath structure in which a high-melting point polymer is a core component and a low-melting point polymer is a sheath component, in terms of ease of heat treatment. More specifically, examples of the fiber include polyolefin fibers with a polypropylene core and a modified polyethylene sheath, fibers with a polyethylene terephthalate core and a polyolefin sheath, and polyester fibers with a polyethylene terephthalate core and a low-melting-point polyester sheath.

<5. Characteristics>

When the cartridge1is manufactured, the distance (the length of the filter member3) L1between the first face31and the second face33of the filter member3is in the aforementioned range with respect to the distance L2between the face203of the first cover portion20and the face221of the second cover portion22in the connected state. Further, the length L1of the filter member3is longer than the distance L3between the leading end portion209of the first protrusion208and the leading end portion225of the second protrusion224in the connected state. With this configuration, at the first face31of the filter member3in the accommodated state, the first protrusion208pierces and engages with a region outward, in the radial direction, of the hollow portion34, a force that compresses the filter member3in the axial direction is applied to the filter member3, and a gap between the first face31and the face203of the first cover portion is shut. Similarly, in the second face33of the filter member3in the accommodated state, the second protrusion224pierces and engages with a region outward, in the radial direction, of the hollow portion34, a force that compresses the filter member3in the axial direction is applied to the filter member3, and a gap between the second face33and the face221of the second cover portion22is shut. With this configuration, the passage of water via the two end faces of the filter member3is suppressed, and raw water in the hollow portion34and purified water in the space230are separated from each other.

Furthermore, as a result of a sealant being applied to the first face31and the second face33themselves, raw water that has flowed into the cartridge1can be more reliably inhibited from flowing into the space230via the first face31and the second face33of the filter member3, and the aforementioned effect can be further enhanced.

The filter member3is elastic due to containing fibrous activated carbon. With this configuration, the filter member3is unlikely to collapse even if a force that compresses the filter member3in the vertical direction is applied thereto via the first cover portion20and the second cover portion22, and there is little possibility that fragments are formed. That is to say, there is little possibility that water in the cartridge1is contaminated, and thus the quality of purified water is maintained. Further, since the filter member3is elastic, the filter member3can be deformed in accordance with the shapes of the protrusions208and224when the protrusions208and224of the first cover portion20and the second cover portion22engage with the filter member3. That is to say, the protrusions208and224and the filter member3can be brought into intimate contact with each other. With this configuration, the aforementioned effect of shutting out raw water can be further improved.

In contrast, for example, a filter member that does not contain fibrous activated carbon but is made only of granular activated carbon is not elastically deformed by a pressing force of the first contact portion and the second contact portion. If pressing force is forcibly applied to such a filter member, the granular activated carbon partially collapses, and there is possibility that the filter member no longer functions. Further, repulsive force is not generated even if a pressing force is applied, and the two end faces of the filter member do not come into intimate contact with the first and second cover portions. For this reason, to prevent raw water that has flowed into the hollow portion of the filter member from passing through a gap between the first face and the first cover portion and a gap between the second face and the second cover portion, an elastic member for sealing these gaps is separately needed.

Compared with an out-in type cartridge that has a filter member3with the same configuration, the in-out type cartridge1has a characteristic that the water filtration rate is fast. In addition, since it is not necessary to ensure liquid tightness at the outer circumferential face of the casing2, the first cover portion20and the second cover portion22can be configured in a detachable manner, and an operation to replace the filter member3can be easily performed.

If the cartridge1has the first resisting portion such as the ribs250, when the pressure of purified water flowing out from the filter member3weakens to a certain degree, purified water that has flowed out into the space230is stopped by the first resisting portion. Since the stopped purified water remains within the casing2, the purified water is unlikely to become droplets and drip from the outflow portion223. Thus, the cartridge1can give a user an impression that the cartridge1is watertight and has a short filtration time.

B. Second Embodiment

A second embodiment of a water purification cartridge according to the present invention will be described below with reference to the diagrams.FIG.9is an external perspective view of a water purification cartridge (which may be hereinafter referred to simply as a cartridge)1according to the present embodiment, andFIG.10is a cross-sectional view. In the following, for convenience of description, the vertical direction inFIG.10is referred to as “above (up, upper etc.)/below (down, lower etc.)”, the left-right direction inFIG.10is referred to as “left/right” or “horizontal”, and the paper plane direction inFIG.10is referred to as “front/back”, and the description is given based on these directions.

The water purification cartridge according to the second embodiment differs from the first embodiment in the configuration of a casing2. More specifically, the cartridge1of the present embodiment is an out-in type cartridge in which raw water that has flowed into a gap between a side wall portion of the casing2and an outer-circumferential face320of a filter member3passes through the filter member3inward in the radial direction, and flows out, as purified water, from the hollow portion of the filter member3. In the following, the same constituent elements are assigned the same reference signs, and a description thereof is omitted.

<1. Casing>

The casing2includes a first cover portion that covers a first face31of the filter member3, a second cover portion that covers a second face33of the filter member3, and a side wall portion that covers the outer circumferential face320of the filter member3. In the present embodiment, as shown inFIG.9, the casing2is configured by connecting the first cover portion20, which covers the first face31of the filter member3, and the second cover portion22, which covers the second face33of the filter member3, are connected to each other, and the side wall portion21is constituted by a side wall portion of the first cover portion20and a side wall portion of the second cover portion22that will be described later. In the following, a state where the second cover portion22is connected to the first cover portion20is referred to as a connected state. In the connected state, a space for accommodating the filter member3is formed within the casing2.

The first cover portion20is constituted by parts that are an upper cover portion20aand a lower cover portion20bthat is integrally connected to a lower end of the upper cover portion20a. As shown inFIG.10, the upper cover portion20ahas a side wall portion231that has a substantially cylindrical shape, and an upper face portion232that is continuous with the side wall portion231and has a substantially circular shape. A plurality of open holes207afor raw water to flow into the cartridge1are formed at intervals in the circumferential direction in a peripheral portion of the upper face portion232, and an inflow portion207in which the plurality of open holes207aare annularly arranged is formed as a whole. A flange204for the cartridge1to be attached to a peripheral portion of an opening S4of a water purifier is formed at an upper outer portion of the side wall portion231. A groove210to which a packing104is fitted is formed at the center in the vertical direction of the flange204.FIG.13Bshows an example of the water purifier. A water purifier100shown inFIG.13Bis the same as that shown inFIG.13Aexcept for the configuration of the cartridge1, and therefore a description of the water purifier100is omitted.

The lower cover portion20bhas a side wall portion233that has a substantially cylindrical shape, and a face portion203′ that is formed within the side wall portion233and has a substantially circular shape. As shown inFIG.10, a plurality of open holes234aare formed in a peripheral portion of the face portion203′ at intervals in the circumferential direction at positions corresponding to the open holes207athat form the inflow portion207, and bring the inside and the outside of the casing2into communication with each other. A face of the face portion203′ that opposes the internal space of the casing2is referred to as a face203. A first protrusion208that has an annular shape is formed on the face203so as to be surrounded by the plurality of open holes234a. That is to say, the first protrusion208is formed inward, in the radial direction, of the open holes207a. In the accommodated state, the first protrusion208annularly comes into contact with the first face31of the filter member3so as to surround the hollow portion34of the filter member3, and presses the filter member3in the axial direction to elastically deform the filter member3. In this case, the first protrusion208serves as the first contact portion that annularly comes into contact with the first face31of the filter member3so as to surround the circumference of the hollow portion34and presses the filter member3in the axial direction to elastically deform the filter member3. In the water purification cartridge of the present invention, the face203may alternatively be a face that does not have a protrusion. For example, the face203may be flat. In this case, the face203serves as the first contact portion that annularly comes into contact with the first face31of the filter member3so as to surround the circumference of the hollow portion34and presses the filter member3in the axial direction to elastically deform the filter member3. The cross-sectional shape of the first protrusion208is not specifically limited, but may be a substantially triangular shape, a substantially rectangular shape, a substantially semicircular shape, a substantially semi-oval shape, or the like. Corners of the substantially triangular shape and the substantially rectangular shape may be rounded.

A ventilation path235, which extends in the front-back direction and has a rectangular cross-section, is formed in the face portion203′ on the side opposing the upper face portion232. The ventilation path235is in communication with vents205that are formed in the side wall portion233and have a rectangular cross-section. The ventilation path235is defined by two side faces that rise from the face portion203′ and are substantially parallel, and an upper face that is continuous with the two side faces, and is therefore isolated from the flow path of water that passes within the cartridge1.

The second cover portion22has a bottom portion227and a side wall portion220that continuously rises from the bottom portion227, and has a substantially cylindrical external appearance as a whole. The side wall portion220is formed to have a substantially cylindrical shape with generally the same diameter as that of the side wall portion231and the side wall portion233. An outflow portion223for purified water to flow out of the cartridge1is formed at a center portion of the bottom portion227. The outflow portion223of the present embodiment is constituted by a circular open hole223a. A face of the bottom portion227that opposes the internal space of the casing2is referred to as a face221. In the face221, a second protrusion224that has an annular shape is formed at a position outward, in the radial direction, of the outflow portion223so as to surround the outflow portion223.

The casing2may also have a second resisting portion that serves as a resistance against a flow of purified water between the hollow portion34of the filter member3and the outflow portion223. The second resisting portion in the present embodiment is a rib251(seeFIG.11) that rises from the face221. The rib251of the present embodiment has an annular shape as viewed from above, and defines the open hole223aon the inner side in the radial direction of the hollow portion34. The rib251is stops purified water from flowing out from the open hole223awhen the pressure of purified water flowing out to the hollow portion34weakens to a certain degree. As a result, purified water can be prevented from becoming droplets and dropping from the outflow portion223.

The maximum height of the rib251based on the face221serving as a reference can be set as appropriate in accordance with the filtering capacity of the filter member3, for example. The maximum height of the ribs251is preferably a height that does not affect at all, or hardly affects, an overall flow of water if the pressure of purified water is greater than or equal to a certain pressure, and with which an outflow of purified water can be stopped if the pressure of the purified water is such that the purified water drips from the outflow portion223.

In the present embodiment, the upper cover portion20aand the lower cover portion20bare connected to each other, and the first cover portion20is connected to the second cover portion22, such that these connecting portions keep liquid tightness. As shown inFIG.9, in the connected state where the first cover portion20and the second cover portion22are connected to each other, the side wall portion231, the side wall portion233, and the side wall portion220are generally flush with each other and form the side wall portion21of the casing2. Ultrasonic bonding or the like is used to connect the upper cover portion20aand the lower cover portion20bto each other and connect the first cover portion20and the second cover portion22to each other.

In the accommodated state, the outer diameter of the filter member3is slightly smaller than the inner diameter of the side wall portion21of the casing2. Thus, in the accommodated state, an annular space230is formed in a gap between the side circumferential portion32and the side wall of the casing2similarly to the first embodiment.

A flow path of water that passes through the cartridge1will be described more specifically below. Main streams of water within the cartridge1are indicated by arrows shown inFIG.11. At first, raw water flows from the tank102into the cartridge1via the inflow portion207, that is, the first cover portion20. The raw water that flows in from the inflow portion207passes through the open holes234aand is temporarily stored in the space230. The raw water stored in the space230passes inward in the radial direction through the side circumferential portion32of the filter member3, and flows, as purified water, into the hollow portion34. The purified water that flows into the hollow portion34is discharged from the outflow portion223to the outside of the cartridge1.

<2. Characteristics>

The configurations of the filter member3, the face203, the face221, the first protrusion208, and the second protrusion224of the second embodiment are the same as those of the first embodiment. Accordingly, the characteristics achieved by the configurations thereof are as described in the description of the first embodiment. Characteristics unique to the second embodiment are described below.

In the cartridge1of the second embodiment, water is filtered inward in the radial direction through the side circumferential portion32of the filter member3. For this reason, another type of filter, such as a hollow fiber membrane, can be further arranged in the hollow portion34, which is an area in which purified water is present. By arranging another type of filter in the hollow portion34, a compact water purification cartridge with higher filtering performance can be provided without increasing the volume of the cartridge1.

If the cartridge1has the second resisting portion such as the rib251, purified water that has flowed into the hollow portion34is stopped by the second resisting portion when the pressure of purified water flowing out from the filter member3weakens to a certain degree. Since the stopped purified water remains within the casing2, the purified water is unlikely to become droplets and drip from the outflow portion223. Thus, the cartridge1can give a user an impression that the cartridge1is watertight and has a short filtration time.

C. Variations

Although the embodiments of the present invention have been described so far, the present invention is not limited to the above embodiments, and various modifications may be made without departing from the gist of the present invention. For example, the following modifications may be made. The gist of the following modifications may be combined as appropriate.

<1>

Although the cartridge1of the above embodiments is mainly attached to a pot-type water purifier when used, the present invention is not limited thereto, and the cartridge1can also be applied to a water purifier of a type that is attached to a water faucet portion or the like when used, for example.

<2>

In the above embodiments, the filter member3is manufactured from a sheet that is made of a mixture of fibrous activated carbon and thermally bonded fiber, but the method for manufacturing the filter member3is not limited thereto. For example, the elastic filter member3can alternatively be manufactured by means of a wet molding method. In the wet molding method, for example, granular activated carbon and a pre-beaten fibrous binder (pulp) are mixed in water. The thus-obtained slurry is suctioned into a mold that has a substantially cylindrical cavity and is molded into the shape of the filter member3. Subsequently, by drying a molded product removed from the mold, the filter member3that is a molded body can be manufactured. In the wet molding method, the hardness of the filter member3can be adjusted using the blending ratio of the pulp used as a binder. In this method, a filter member with a hardness of about 77 can be formed, for example.

<3>

In the above embodiments, the vents205are formed in the side face of the casing2, but the formation of the vents205can be omitted.

<4>

The modes of the inflow portion207and the outflow portion223are not limited to the modes described in the above embodiments. For example, the numbers of open holes207aand open holes223aand the shapes thereof can be changed as appropriate. For example, the inflow portion207in the first embodiment does not need to be formed to have a flat-bottomed container shape that is recessed downward, and may alternatively be formed to have a flat shape as a whole, or a cylindrical shape that protrudes upward. The open holes223ain the first embodiment may be formed on the lower side of the side wall portion220rather than in the bottom portion227. For example, the inflow portion207in the second embodiment is formed in the upper face portion232and is flat as a whole, but may alternatively be formed in a flat-bottomed container shape that is recessed downward from the upper face portion232, or may contrarily be formed to protrude upward. Furthermore, the outflow portion223in the second embodiment may be formed to have a cylindrical shape that protrudes downward from the bottom portion227, for example.

<5>

In the first embodiment, the first cover portion20and the second cover portion22can be detached from each other, but the first cover portion20and the second cover portion22can alternatively be configured to not be able to be detached from each other. Various connection mechanisms other than the engagement between the claw portions206and the window portions222can be employed as the connection mechanism for connecting the first cover portion20and the second cover portion22. Further, the shapes of the first cover portion20and the second cover portion22are not limited to the above-described shapes. The shapes of the first cover portion20and the second cover portion22can be changed as appropriate as long as the first cover portion20has the first contact portion that comes into contact with the first face31of the filter member3and presses the filter member3in the axial direction to elastically deform the filter member3, and the second cover portion22has the second contact portion that comes into contact with the second face33of the filter member3and presses the filter member3in the axial direction to elastically deform the filter member3. For example, the second cover portion22does not need to have the side wall portion220, and may only have the bottom portion227.

<6>

In the second embodiment, the first cover portion20is constituted by the upper cover portion20aand the lower cover portion20b, but the method for forming the first cover portion20is not limited thereto. For example, the upper cover portion20aand the lower cover portion20bmay be integrally formed to constitute the first cover portion20. The shapes of the first cover portion20and the second cover portion22are not limited the above-described shapes, and may be changed as appropriate as long as the first cover portion20comes into intimate contact with the first face31of the filter member3, and the second cover portion22comes into intimate contact with the second face33of the filter member3. For example, the second cover portion22does not need to have the side wall portion220, and may only have the bottom portion227.

<7>

The number of first protrusions208and second protrusions224is not limited to one as in the above embodiments. For example, two or more first protrusions208and second protrusions224may be formed concentrically. In this case, the number of first protrusions208formed may differ from the number of second protrusions224.

<8>

The modes of the ribs250and openings223bare not limited to the example shown inFIGS.7and8. That is to say, the mode of the ribs250and the mode of the openings223bcan be changed in any combination. For example, the ribs250may alternatively be formed so as to be continuous with the side wall portion21at two ends in the circumferential direction as shown inFIGS.7and8, or may be formed to have a wall shape that rises from the bottom portion227independently of the side wall portion21. From the viewpoint of maintaining the strength of the ribs250, at least some of the ribs250are preferably formed so as to be continuous with the side wall portion21. Further, the cross-sectional shape of the ribs250is not limited to the shape shown inFIGS.7and8, and may be changed as appropriate. In the example shown inFIGS.7and8, the openings223bare open laterally and downward of the second cover portion22, but the mode of the openings223bis not limited thereto. For example, the open holes223bmay be open only downward of the second cover portion22, as the open holes223ashown inFIG.3Dare. In another example, the openings223bmay be open only laterally of the second cover portion22. In this case, the openings223bmay be formed above the face221of the bottom portion227, and a portion of the side wall portion21that is sandwiched between the face221and a lower end of the openings223bmay be the first resisting portion.

<9>

The modes of the rib251and the open hole223aare not limited to the example shown inFIG.11. That is to say, the mode of the rib251and the mode of the open hole223acan be changed in any combination. For example, in the example inFIG.11, the rib251defines the open hole223a. However, a rib251may be formed that rises from the face221independently of a peripheral portion that defines the open hole223a. If a plurality of open holes223aare formed, the rib251may be provided at a peripheral edge of each open hole223a, or the rib251may be provided so as to surround the plurality of open holes223a. Further, the cross-sectional shape of the rib251is not limited to the shape shown inFIG.11, and may be changed as appropriate.

EXAMPLES

Examples and a comparative example will be given below to describe the present invention in detail. However, the present invention is not limited to the examples.

Six types of water purification cartridges that are the same as the above-described first embodiment were prepared as examples 1 to 6. All of the filter members of the water purification cartridges in the examples 1 to 6 were formed with a sheet that is made of a mixture of fibrous activated carbon and thermally bonded fiber, and were manufactured by the manufacturing method illustrated inFIG.12. In the filter members of the water purification cartridges in the examples 1 to 3, a sealant (a hot melt adhesive containing ethylene vinyl acetate (EVA) as a main component) was applied to the first face and the second face, and the hardness of the filter members was 86. The water purification cartridges in the examples 1 to 3 had a common configuration and were formed to have the same dimensions except that the length L1of the filter member differed as shown in Table 1 below. In the filter members of the water purification cartridges in the examples 4 to 6, the sealant was not applied to the first face or the second face, and the hardness of the filter member was 65. The water purification cartridges in the examples 4 to 6 had a common configuration and were formed to have the same dimensions except that the length L1of the filter member differed as shown in the table 1 below.

As a comparative example 1, the same casing as those of the examples 1 to 6, and a filter member that is formed by compressing a material that is made of granular activated carbon and thermosetting resin (binder) and does not contain fibrous activated carbon, were prepared. The shape of this filter member was the same as those of the filter of the examples 1 to 6, and the sealant was not applied to the first face or the second face. The hardness of the filter member in the comparative example 1 was 90.

The configuration and the dimensions of the casing are common to the examples 1 to 6 and the comparative example 1. The material of the casing was ABS resin, and the hardness thereof was 95. L2and L3of the casing were 53 mm and 51.2 mm, respectively. The characteristics of the examples 1 to 6 and the comparative example 1 are as collectively shown in Table 1.

TABLE 1ComparativeExamplesexampleNumber1234561FilterSheet-shaped mixture of fibrous activated carbon andMixture ofmemberthermally bonded fibergranularactivatedcarbon andthermosettingresinHardness866590of filtermemberApplicationAppliedNot appliedNot appliedof sealantL1 (mm)52.452.653.052.452.653.052.4L2/L1 × 100101.1100.8100.0101.1100.8100.0(%)L3/L1 × 10097.797.396.697.797.396.6(%)
(Experiment)

Water containing free residual chlorine with an initial concentration of 2 mg/L was passed through each of the water purification cartridges of the examples 1 to 6 and the comparative example 1, and the presence of leakage was checked. Also, with the water purification cartridges in the examples 1 to 6, the filter member was removed from the casing after passing the water therethrough, the distance L4between a portion of the casing that came into contact with the first contact portion (first protrusion) and a portion of the casing that came into contact with the second contact portion (second protrusion) was measured, and the degree of elastic recovery of the filter member was evaluated based on the proportion W (%) of the distance L4to the length L1.

(Experimental Results)

Examples 1 to 3: Water containing free residual chlorine with an initial concentration of 2 mg/L was passed through the water purification cartridges, and no leakage was found. That is to say, it was confirmed that raw water that flowed into the hollow portion of the filter member can be prevented from passing through a gap between the first face and the first cover portion and a gap between the second face and the second cover portion, and that the passage of the raw water through the filter member can be promoted. The proportion W was 99.5%, and the filter member elastically recovered substantially to almost the same degree as before the water was passed through the water purification cartridges.

Examples 4 to 6: Water containing free residual chlorine with an initial concentration of 2 mg/L was passed through the water purification cartridges, and no leakage was found. That is to say, it was confirmed that raw water that flowed into the hollow portion of the filter member can be prevented from passing through a gap between the first face and the first cover portion and a gap between the second face and the second cover portion, and that the passage of the raw water through the filter member can be promoted. The proportion W was about 98 to 99%.

Comparative example 1: When the filter member was attempted to be accommodated in the casing, the filter member was hardly elastically deformed and therefore cannot be sufficiently compressed, and the first face and the second face was partially scraped and partially collapsed. As a result of the filter member being accommodated in this state in the casing and water being passed therethrough, raw water leaked.

REFERENCE SIGNS LIST

1Cartridge2Casing3Filter member20First cover portion21Side wall portion22Second cover portion31First face32Side circumferential portion33Second face34Hollow portion203Face207Inflow portion208First protrusion (first contact portion)221Face223Outflow portion224Second protrusion (second contact portion)230Space300Sheet