Support structure for holding filter medium

Abstract: A protector (1) for holding a filter medium (8) thereon is made of resin and composed of a plurality of pillar members (1a). The pillar members (1a) are disposed in parallel with each other in a longitudinal direction thereof and forming a circular shape (1A) with intervals respectively between adjacent two pillar members (1a). Accordingly, the protector (1) can be easily manufactured by molding and can be easily scrapped after its use. The protector (1) further has a positioning member (1D) for positioning the protector (1) in a case (3). Accordingly, a number of parts in a filter device can be reduced, resulting in increase in man-hour for assembling the parts.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention: The present invention relates to a protector for holding a filter medium thereon, which is used for a filter. 2. Related Arts: JP-U-4-118105 discloses an oil filter including a filter member composed of a filter medium member and a protector for holding the filter medium member thereon to reinforce strength of the filter member and to keep a specific shape of the filter medium member. Specifically, the protector is made of a punching metal plate having plural holes and has a cylindrical shape. The protector is disposed on an inner circumference of the filter medium member, thereby forming the filter member. The filter member is located on a specific position within a case by a plate spring. In the above-mentioned oil filter, however, the protector cannot be easily scraped when the filter member is exchanged. The handling of the protector is difficult. This is because the protector is made of metal so that the protector is not burned together with the filter medium member. In addition, in the above-mentioned oil filter, the protector for keeping the shape of the filter medium member and the part (the plate spring) for positioning the filter member are respectively provided, resulting in increase in number of parts. The increase in number of the parts causes increase in man-hour for assembling the parts. Furthermore, DE-A-19 26 357 shows a filter having a protector for holding a filter medium. The protector is made from resin and comprises a plurality of longitudinally extending first pillar members arranged in parallel to each other, and further second pillar members extending in parallel to the first pillar members arranged in a circle The pillar members are adapted to support a filter medium. Moreover, US-A-5 306 424 discloses a fuel filter having a protector for the filter medium, which protector has an elastically deformable positioning member protruding from the protector for positioning the protector in the case of the filter. In view of the above prior art, it is the object of the invention to provide a protector for holding a filter medium, which is suitable for making a compact filter while having improved filtration yield. This object is solved with a protector having the features of independent claim 1 or claim 8. BRIEF DESCRIPTION OF THE DRAWINGS These and other features of the present invention will become more readily apparent from a better understanding of a preferred embodiment described below with reference to the following drawings. FIG. 1 is a cross-sectional view showing a filter device in a preferred embodiment of the present invention; FIG. 2 is a side view showing a protector of the filter device in the embodiment; FIG. 3 is a top end view showing the protector; FIG. 4 is a cross-sectional view taken along a IV-IV line in FIG. 3, partially showing the protector; FIG. 5 is a fragmentary cross-sectional view showing a filter member composed of the protector and a filter medium member in the embodiment; FIG. 6 is a top end view showing the filter member; FIG. 7 is a schematic view showing a suction apparatus for forming the filter medium member on the protector; and FIG. 8 is a fragmentary cross-sectional view for explaining a process for forming the filter medium member on the protector. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A protector 1 in a preferred embodiment of the present invention is used for a filter device 2 for filtering an engine oil as shown in FIG. 1. The filter device 2 has a case 3, a filter member 4, a plate 5, a movable valve member 6 made of rubber, a gasket 7, and the like. The movable valve member 6 serves as a check valve and a relief valve. The case 3 is made of, for example, iron and has a cylindrical shape having a bottom wall at an end thereof and an opening portion at the other end thereof. The filter member 4 includes the protector 1 and a filter medium member 8 held on the protector. The protector 1 will be described later in more detail. The plate 5 holds the filter member 4 together with the case 3. The plate 5 has an oil outlet 5a at a central portion thereof and several oil inlets 5b at a peripheral portion of the oil outlet 5a. The oil flowing from an engine (the oil before filtered) flows into the oil inlets 5b, and the oil filtered by the filter member 4 (filter medium member 8) is discharged from the oil outlet 5a. The inner circumferential surface of the oil outlet 5a serves as a female screw 5c that is to be engaged with a male screw provided on a mounting base (not shown) on an engine side. The movable valve member 6 is disposed between the plate 5 and the filter member 4 and opens and closes the oil inlets 5b of the plate 5. More specifically, the movable valve member 6 opens the oil inlets 5b only when the oil flowing from the engine flows into the oil inlets 5b. The gasket 7 is made of, for example, rubber, and disposed on the opening portion of the case 3 for hermetically sealing the case 3 with respect to the mounting base on the engine side. Then, the filter member 4 composed of the protector 1 and the filter medium member 8 will be explained. The protector 1 is molded from resin, and has heat resistance and oil resistance. As shown in FIGS. 2 and 3, the protector 1 has a plurality of pillar members 1a arranged with a comb-like shape in a side view and with a stellate shape in a cross-sectional view. The pillar members 1a form a protector body in this embodiment. The arrangement of the comb-like shape means that the pillar members 1a are arranged substantially in parallel with each other (in a vertical direction in FIG. 2) with intervals respectively between adjacent two ones. The arrangement of the stellate shape is as follows. As shown in FIG. 3, some of the pillar members 1a are arranged with a circular shape, thereby forming a cylindrical portion 1A as a central portion of the stellate shape. The other of the pillar members 1a are arranged with several U-shapes to form several (nine in this embodiment) protruding portions 1B of the stellate shape, which protrude outside from an outer circumference in a radial direction of the cylindrical portion 1A. The pillar members 1a forming the cylindrical portion 1A are connected to a cylinder member 1C shown in FIG. 2 on a plate side. The pillar members 1a forming the cylindrical portion 1A are further connected to a circular connecting member 1b (see FIG. 2) at a generally central portion in a longitudinal direction thereof. Accordingly, the pillar members 1a are fixed in a circumferential direction thereof by the circular connecting member 1b. The connecting member 1b has protruding portions for connecting the pillar members 1a forming the protruding portions 1B as well (see FIGS. 3 and 4). Further, as shown in FIG. 3, several ribs 1c elongating in a radial direction of the cylindrical portion 1A and a circular rib 1d connecting the ribs 1c are provided on an upper end face of the cylindrical portion 1A. The cylindrical portion 1A and the protruding portions 1B are explained in more detail. In FIG. 3, a part of the pillar members 1a-1 to 1a-8 are hatched for the explanation. The cylindrical part 1A includes three types of pillar members 1a-1 to 1a-3 having generally plate-like shapes and radially arranged to form a part of the circular shape in cross-section of the cylindrical part 1A. The pillar members 1a-1 and 1a-3 are connected to the ribs 1c on upper ends thereof, while the pillar member 1a-2 is independent on an upper end thereof. All of the pillar members 1a-1 to 1a-3 are, as mentioned above, connected to the cylinder member 1C at lower ends thereof. Each of the protruding portions 1B has five pillar members 1a-4 to 1a-8, and the pillar members 1a-4 to 1a-8 are connected to a plate-like member 1e at upper ends thereof, and are independent at lower end thereof. As mentioned above, all of the pillar members 1a-1 to 1a-8 are connected to the connecting member 1b at the center portion in a longitudinal direction thereof, and elongate in upper and lower directions with respect to the connecting members 1b. Further, each of the protruding portions 1B has a positioning member 1D for positioning the protector 1 on a specific location within the case 3. As shown in FIG. 4, the positioning member 1D elongates in an upper direction from an outer circumference on an upper end of the protruding portion 1B and then bends to protrude outside in the radial direction of the cylindrical portion 1A. The thus formed positioning member 1D is disposed on the protruding portion 1B such that it can be elastically deformed with respect to the protruding portion 1B. The outer surface 1f of the bent portion of the positioning member 1D abuts an inside surface of the case 3 so that the protector 1 is positioned at a specific portion in the case 3 (see FIG. 1). The cylinder member 1C is, as shown in FIG. 1, engaged with the movable valve member 6 with air-tightness. Accordingly, the cylinder member 1C serves as a valve seat that moves together with the movable valve member 6 and divides the filter medium member 8 into an upstream side (before filtering) and a downstream side (after filtering). The cylinder member 1C serving as a second circular connecting member is disposed on an inner side in the radial direction of the cylindrical portion A compared with the connecting member 1b serving as a first circular connecting member. Therefore, the two circular connecting members can be molded by a die capable of being separated in an axial direction thereof. Further, the cylindrical portion 1A has the ribs 1c radially elongating on the upper end face thereof and disposed on an inner side with respect to the cylinder member 1C to connect several pillar members 1a. Therefore, the shape of the protector 1 is retained with sufficient strength. The plate-like members 1e are disposed on an upper ends of the protruding portions 1B to respectively surround the protruding portions of the connecting member 1b in a projected state, thereby retaining the shapes of the protruding portions 1B. The filter medium member 8 is, as shown in FIGS. 5 and 6, disposed on the side, upper, and lower surfaces of the protector 1. That is, the filter medium member 8 is disposed on the outer surfaces of the assembled member (protector) composed of a plurality of the pillar members 1a. Accordingly, the protector 1 provides a passage space for the oil inside of the filter medium member 8 while retaining the shape of the filter medium member 8. The filter medium member 8 is disposed on the protector 1 in the following way by using a suction apparatus 9 shown in FIG. 7. Specifically, the suction apparatus 9 has a water tank 10 filled with slurry including fibers, an agitator 11 for agitating the slurry within the water tank 10, a suction jig 12 immersed in the slurry within the water tank 10, a suction pump 15, a suction pipe 13 connecting the suction jig 12 and the suction pump 15, a discharge pipe 14, and the like. The suction pump 15 sucks the slurry from the water tank 10 through the suction jig 12 and the suction pipe 13 and brings the slurry back into the water tank 10 through the discharge pipe 14. The fibers for the filter medium member 8 is preferably made of polyester useful for obtaining high oil resistivity, acrylic useful for obtaining high filtering property, pulp capable of reducing cost, or the like. As shown in FIG. 8, the suction jig 12 has a suction core 12A having a cylindrical shape, and the protector 1 is attached to the outer circumference of the suction core 12A. That is, the protector 1 is used as a part of the suction jig 12 as a suction base. Next, processes for forming the filter medium member 8 will be explained. Firstly, fibers that are finely cut by a mixer (not shown) or the like in advance are mixed with binder fibers (thermally fusing fibers), put into the water tank 10, and then agitated by the agitator 11 such that a concentration of the fibers in the slurry within the water tank 10 becomes uniform. Subsequently, the suction jig 12 is immersed into the slurry. Then, the suction pump 15 is operated. Accordingly, the slurry within the water tank 10 circulates in a route of the water tank 10 → the suction jig 12 → the suction pipe 13 → the suction pump 15 → the discharge pipe 14 → the water tank 10. As a result of this suction process, a part of the fibers contained within the slurry are attached on the surface of the protector 1, and successively other fibers are deposited on the fibers attached on the protector 1 to form a layer (see FIG. 8). Consequently, a filter medium body 80 for the filter medium member 8 covering the protector 1 is obtained (see FIGS. 5 and 6). After forming the filter medium body 80, the filter medium body 80 is detached from the suction jig 12 together with the protector 1 and taken out from the water tank 10. Then, the filter medium body 80 and the protector 1 are dehydrated and heated at a specific temperature such that the filter medium body 80 is dried and hardened. Subsequently, after binder resin is impregnated into the filter medium body 80, the filter medium body 80 is heated again at a specific temperature along with the protector 1 such that the binder resin is hardened. As a result, the filter member 4 composed of the protector 1 and the filter medium member 8 is obtained. The binder resin is thermosetting resin such as phenol resin or the like. In the thus formed filter member 4, as shown in FIG. 5, the positioning members 1D are embedded in the filter medium member 8 while exposing the outer surfaces 1f of the bent portions thereof. Therefore, when the filter member 4 is positioned in the case, the outer surfaces 1f of the positioning members 1D abut the inside surface of the case 3 to position the filter member 4 within the case 3. Accordingly, positioning accuracy of the filter member 4 is improved. In this embodiment, the several positioning members 1D are symmetrically disposed in the protector 1, so that the positioning accuracy of the protector 1 (filter member 4) is further improved. Further, in this case, no stress is applied to the filter medium member 8 within the case 3. That is, the filter medium member 8 is held only by the protector 1 within the case 3, and there is no need that the filter medium member 8 is pushed against the inside surface of the case 3. Furthermore, there is no need to use an extra part for positioning the protector 1 within the case 3, resulting in decrease in number of the parts and decrease in man-hour for assembling the parts. In this embodiment, the positioning members 1D are formed to be elastically deformed with respect to the protruding portions 1B. Therefore, deviation in positioning of the protector 1 in the case 3 can be absorbed by elastic deformation of the positioning members 1D. According to this embodiment, the protector 1 is made of resin. Therefore, the filter member 4 can be easily scrapped (burned) after its use, so that the handling of the filter member 4 becomes easy compared to a conventional filter member including a protector made of metal. The protector 1 is composed of a plurality of the pillar members 1a arranged with the comb-like shape. Therefore, when the protector 1 is molded by a die, the protector 1 is easily taken out from the die in the axial direction thereof. That is, the protector 1 has good moldability. In addition, when forming the filter medium member 8 on the protector 1, the protector 1 is used as the suction base. Therefore, although the filter medium body 80 is in a sorbet-like state or a cotton-like state just after deposited, the filter medium body 80 can be easily detached from the suction jig 12 together with the protector 1 by holding the protector 1. Further, the protector 1 has the connecting member 1b connecting the pillar members 1a of the cylindrical portion 1A and the pillar members 1a of the protruding portions 1B. The protector 1 further has the ribs 1c and the cylinder member 1C connecting the pillar members 1a of the cylindrical portion 1A on the upper and lower ends of the cylindrical portion 1A. Accordingly, the pillar members 1a are reinforced, so that the strength (stiffness) of the protector 1 is improved. As a result, the strength of the filter member 4 is improved. Further, the cylinder member 1C of the protector 1 is engaged with the movable valve member 6 and serves as the valve seat. Simultaneously, the cylinder member 1C sandwiches the movable valve member 6 in cooperation with the plate 5, so that the upstream side and the downstream side of the filter medium member 8 is hermetically divided by the movable valve member 6. In this case, the movable valve member 6 serves as a sealing member. In this embodiment, when forming the protector 1 by molding, the protector 1 composed of a plurality of the pillar members 1a is taken out from the die in the axial direction thereof, however, it is not necessary for the protector 1 to be taken out from the die in the axial direction. The protector 1 may have a shape capable of being taken out from a die in a radial direction or the like. In this embodiment, the connecting member 1b is adopted to the protector 1 for connecting the pillar members 1a at the generally central portion in the longitudinal direction of the pillar members 1a. Alternatively, several connecting members for connecting the pillar members may be disposed at several portions in the longitudinal direction of the pillar members 1a. In this case, the strength of the protector 1 is more improved. Further, by disposing the several connecting members in different positions in the radial direction of the cylindrical portion 1A, the protector 1 can be easily molded In this embodiment, although the filter medium member 8 is formed form the filter medium body 80 deposited on the protector by the suction process, a filter paper folded into a chrysanthemum-like shape or the like may be used as the filter medium member 8. In this embodiment, the pillar members 1a of the protector 1 are arranged with the satellite shape having the cylindrical portion 1A and the protruding portions 1B, and the positioning members 1D are respectively disposed on the protruding portions 1B. However, it is not always necessary that the protector 1 has the protruding portions 1B. When the protector 1 only has the cylindrical portion 1A, the positioning members 1D may be disposed on the upper end face of the cylindrical portion 1A, and may be connected to the upper end face of the cylindrical portion 1A directly or through some members. A protector (1) for holding a filter medium (8) thereon is made of resin and composed of a plurality of pillar members (1a). The pillar members (1a) are disposed in parallel with each other in a longitudinal direction thereof and forming a circular shape (1A) with intervals respectively between adjacent two pillar members (1a). Accordingly, the protector (1) can be easily manufactured by molding and can be easily scrapped after its use. The protector (1) further has a positioning member (1D) for positioning the protector (1) in a case (3). Accordingly, a number of parts in a filter device can be reduced, resulting in increase in man-hour for assembling the parts.

Claims: A protector (1) for holding a filter medium (8) for separating particulate matter from fluid, the protector (1) being made of resin and comprising a plurality of first pillar members (Fig. 3; 1a-1 to 1a-3) disposed in parallel with each other in a longitudinal direction of the first pillar members (Fig. 3; 1a-1 to 1a-3) and forming a circular shape (Fig. 3; 1A) with intervals respectively between adjacent two pillar members (1a) and a plurality of protruding portions (Fig. 3; 1B) protruding from the circular shape (Fig. 3; 1A) of the plurality of first pilar members (Fig. 3; 1a-1 to 1a-3) in a radial direction, each of which being formed of second pilar members (Fig. 3; 1a-4 to 1a-8), characterized in that each of protruding portions (Fig. 3; 1B) are formed of a plurality of second pilar members (Fig. 3; 1a-4 to 1a-8). The protector (1) according to claim 1, further comprising a first circular connecting member (1b) connecting the first pillar members (1a) in a circumferential direction of the circular shape (1A). The protector (1) according to claim 2, further comprising a second circular connecting member (1C) connecting the first pillar members (1a) in the circumferential direction of the circular shape (1A) and disposed at a position different from that of the first circular connecting member (1b) in a longitudinal direction of the first pillar members (1a) and in a radial direction of the circular shape (1A). The protector (1) according to claim 3, wherein the second circular connecting member (1C) has a cylindrical shape and connects the first pillar members (1a) at end portions in the longitudinal direction of the first pillar members (1a). The protector (1) according to claim 1, further comprising a positioning member (1D) for positioning the protector (1) within a case (3) by abutting the case (3) when the protector (1) is held in the case (3), the positioning member (1D) made of resin and integrally connected to the pillar members (1a). The protector (1) according to claim 1, further comprising a positioning member (1D) for positioning the protector (1) in a case (3) by abutting the case (3) when the protector (1) is held in the case (3), wherein: the first pillar members (1a) are arranged to substantially form a cylindrical shape (1A) with intervals between adjacent two pillar members (1a); and the positioning member (1D) is disposed on an end in an axial direction of the cylindrical shape (1A) of the first pillar members (1a) and connected to the first pillar members (1a) to protrude from a side surface of the cylindrical shape of the first pillar members (1a). The protector (1) according to claim 6, wherein the positioning member (1D) is connected to the protruding portion of the plurality of second pillar members (1a). A protector (1) for holding a filter medium (8) for separating particulate matter from fluid, the protector (1) being held in a case (3) and comprising a protector body (1A, 1B) for holding the filter medium (8) and a positioning member (1D) integrally connected to the protector body (1A, 1B) for positioning the protector (1) within the case (3), wherein the positioning member (1D) is elastically deformable, and protrudes from the protector body (1A, 1B), characterized in that the positioning member (1D) is embedded in the filter medium (8) while exposing an outer surface (1f) for abutting the case (3). The protector (1) according to claim 8, wherein: the protector body (1A, 1B) includes a plurality of pillar members (1a) disposed in parallel with each other to have a cylindrical shape (1A) with intervals respectively between adjacent two pillar members (1a); and the positioning member (1D) is disposed on an end of the cylindrical shape of the pillar members (1a) and integrally connected to the pillar members (1a) to protrude from a side face of the cylindrical shape of the pillar members (1a). The protector (1) according to claim 9, wherein the positioning member (1D) includes several positioning portions disposed along an outer circumference of the cylindrical shape of the pillar members (1a). The protector (1) according to claim 8, wherein the positioning member (1D) is elastically deformed with respect to the protector body (1A, 1B). The protector (1) according to claim 8, wherein the filter medium (8) is held only by the protector (1) in the case (3). The protector (1) according to claim 8, wherein the protector (1) abuts the case (3) only through the positioning member (1D).

Inventors: SANAMI YOSHIHISA, TAKAHARA TOSHIHIRO, YAMAGUCHI SHUJI, SANAMI, YOSHIHISA, TAKAHARA, TOSHIHIRO, YAMAGUCHI, SHUJI
Applicants: DENSO CORP, DENSO CORPORATION
Application year: 1998
Main classification: B01D27
IPC codes: B01D29, B01D27