OIL STRAINER

Abstract

A casing includes: a flat portion housing a filter; an oil outlet cylinder projecting from the flat portion, having a cylindrical shape, and being provided with an oil outlet opening at a distal end; and an extension portion extending a flow passage cross section of a proximal end portion of the oil outlet cylinder in a width direction of the flat portion.

Claims

1. An oil strainer comprising: a filter filtering oil; and a casing housing the filter, and having an oil inlet opening through which the oil flows into the casing, and an oil outlet opening through which the oil which has been filtered in the casing flows out of the casing, wherein the casing includes a flat portion having a flat shape with a desired thickness and housing the filter, an oil outlet cylinder projecting from the flat portion, having a cylindrical shape with an inside diameter smaller than a width, of the flat portion, being perpendicular to a direction of an oil flow, and provided with the oil outlet opening at a distal end of the oil outlet cylinder, and an extension portion extending a flow passage cross section of a proximal end portion of the oil outlet cylinder in a width direction of the flat portion.

2. The oil strainer of claim 1, wherein the extension portion is located downstream, in a direction of oil flow, of a housing room provided in the flat portion and housing the filter, and includes hollow space communicating with the proximal end portion of the oil outlet cylinder.

3. The oil strainer of claim 1, wherein the casing is formed by welding together a first casing component and a second casing component which are separate from each other in a thickness direction of the flat portion, the extension portion protrudes from a proximal end portion of a peripheral wall of the first casing component toward an outside of the first casing component, and a rib is formed in a distal end portion of the peripheral wall of the first casing component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a perspective view of an oil strainer according to an embodiment, as viewed from above.

[0028] FIG. 2 is a perspective view of the oil strainer, as viewed from below.

[0029] FIG. 3 is a perspective view of the oil strainer with a lower casing component detached from the oil strainer, as viewed from below.

[0030] FIG. 4 is a perspective view of a filter, as viewed from below.

[0031] FIG. 5 corresponds to a cross-sectional view taken along the line V-V in FIG. 1, and illustrating the oil strainer with the lower casing component detached from the oil strainer.

[0032] FIG. 6 illustrates an upper casing component, as viewed from an oil outlet opening.

[0033] FIG. 7 is a perspective view of the upper casing component, as viewed from above.

[0034] FIG. 8 corresponds to a cross-sectional view taken along the line V-V in FIG. 1, and illustrating the oil strainer as viewed from above.

DETAILED DESCRIPTION

[0035] An embodiment of the present disclosure will be described below in detail with reference to the drawings. Note that the following embodiment is merely a beneficial example in nature, and is not intended to limit the scope, application, or uses of the present disclosure.

[0036] FIG. 1 is a perspective view of an oil strainer 1 according to an embodiment of the present disclosure, as viewed from above. For example, the oil strainer 1 may be arranged in an oil pan (not shown) of an engine or an oil pan (not shown) of an automatic transmission mounted in a vehicle such as an automobile. The oil strainer 1 is configured to filter oil retained in the oil pan, and then, to supply the filtered oil to an oil pump (not shown). Note that the oil strainer 1 may be arranged not only in an engine or an automatic transmission, but also in a machine in which oil is circulated.

[0037] The oil strainer 1 includes a filter 2 (illustrated in FIGS. 2-5 and 8) configured to filter oil, and a casing 3 (illustrated in FIGS. 1 and 2) housing the filter 2. The casing 3 includes a flat portion 3a having a flat shape with an arbitrary thickness, and an oil outlet cylinder 3b. The flat portion 3a is configured to house the filter 2, and corresponds to a portion, of the casing 3, extending horizontally and having a thick plate shape, in this embodiment. The flat portion 3a is shaped to have a greater dimension in a depth direction of the oil strainer 1 than in a width direction of the oil strainer 1. However, the flat portion 3a is not limited to this shape, but may be shaped to have a greater dimension in the width direction of the oil strainer 1 than in the depth width direction of the oil strainer 1. Further, the flat portion 3a may have a substantially rectangular shape, or a shape close to an ellipse or a circle, in plan view.

[0038] As illustrated in FIGS. 5 and 8, the flat portion 3a includes therein a filter housing room R in which the filter 2 is housed and through which the oil flows. The flat portion 3a has a longitudinal cross-section shape, taken along a line perpendicular to the depth direction, which is long in the horizontal direction. As illustrated in FIG. 2, the flat portion 3a has a lower wall 21. In the lower wall 21, an oil inlet opening 5 communicating with the filter housing room R is provided close to a far side and a left side. Thus, the oil in the oil pan enters a far side portion of the flat portion 3a. The oil inlet opening 5 may be circular or elliptic.

[0039] As illustrated in FIG. 1, the oil outlet cylinder 3b projects horizontally from an upper left portion, of the flat portion 3a, located close to the near side. Therefore, the oil that has flowed through the oil inlet opening 5 into the flat portion 3a, passes through the filter 2, while flowing inside the flat portion 3a from the far side to the near side, and then, flows out of an upper portion of the flat portion 3a. The upstream side and downstream side in the direction of the oil flow in the oil strainer 1 correspond to the far side and the near side, respectively.

[0040] The oil outlet cylinder 3b has a circular cross section in a portion between its center in the direction in which the oil outlet cylinder 3b projects (hereinafter referred to as the cylinder projecting direction) and its distal end. The inside diameter of the distal end portion of the oil outlet cylinder 3b is smaller than a width dimension, of the flat portion 3a, being perpendicular to the oil flow direction. As can be seen, the distal end portion of the oil outlet cylinder 3b has a circular cross section, whereas the flat portion 3a has a cross-section shape that is long in the horizontal direction. Thus, the oil outlet cylinder 3b and the flat portion 3a differ from each other significantly in their cross-sectional shapes.

[0041] The oil outlet cylinder 3b has, at its distal end in the cylinder projecting direction, an oil outlet opening 4 which has a circular shape. The oil outlet opening 4 communicates with the filter housing room R via the inside of the oil outlet cylinder 3b, and is configured to allow the filtered oil that has passed through the filter 2 to flow out. The oil outlet opening 4 is connected to a suction port of an oil pump (not shown). The oil outlet opening 4 and the oil inlet opening 5 have substantially the same opening area.

[0042] As illustrated in FIG. 1, an upper end of the distal end portion of the oil outlet cylinder 3b in the cylinder projecting direction is located above the upper surface of the flat portion 3a. A lower end of the distal end portion of the oil outlet cylinder 3b in the cylinder projecting direction is located above the lower surface of the flat portion 3a.

[0043] A first rib 3c projects radially outwardly from, and extends continuously and circumferentially on, the distal end portion of the oil outlet cylinder 3b in the cylinder projecting direction. Further, between the first rib 3c and a proximal end of the oil outlet cylinder 3b, a second rib 3d which is spaced from the first rib 3c projects radially outwardly from, and extends continuously and circumferentially on, the distal end portion of the oil outlet cylinder 3b in the cylinder projecting direction. A sealing member (not shown) may be fitted between the first and second ribs 3c and 3d.

[0044] The oil outlet cylinder 3b has, at a portion between its center in the cylinder projecting direction and the proximal end, an upper inclined wall portion 3e forming part of the upper wall of the oil outlet cylinder 3b. As illustrated in FIG. 5, the upper inclined wall portion 3e is inclined downwardly from the near side to the far side, i.e., toward the proximal end of the oil outlet cylinder 3b in the cylinder projecting direction. The oil outlet cylinder 3b has, at a portion between its center in the cylinder projecting direction and the proximal end, a lower inclined wall portion 3f forming part of the lower wall of the oil outlet cylinder 3b. The lower inclined wall portion 3f is inclined upwardly toward the proximal end of the oil outlet cylinder 3b in the cylinder projecting direction. Due to the formation of the upper and lower inclined wall portions 3e and 3f, the oil outlet cylinder 3b has, between the center in the cylinder projecting direction and the proximal end, a cross-sectional area decreasing toward the proximal end.

[0045] As illustrated in FIGS. 1 and 2, the casing 3 is formed by welding together an upper casing component 10 and a lower casing component 20 which are separate from each other. These casing components are welded to each other at an intermediate point in the vertical direction, i.e., in the thickness direction of the flat portion 3a. The oil outlet cylinder 3b is formed on the upper casing component 10. Each of the upper and lower casing components 10 and 20 is formed by injection-molding a resin material.

[0046] The upper casing component 10 has an upper wall 11 and a peripheral wall 12 extending downward from a peripheral edge of the upper wall 11. A left portion of the upper wall 11 protrudes upward to be located above a right portion of the upper wall 11. An upper flange 12a which projects toward the outside of the casing 3 extends circumstantially on a lower end portion of the peripheral wall 12. The upper flange 12a has a plurality of portions recessed upward, and these portions function as jig engagement portions 12b. A jig (not shown) is engaged with the jig engagement portions 12b to be employed when the upper and lower casing components 10 and 20 are welded together. As illustrated in FIG. 3, a weld rib 12f extends over the entire periphery of a lower surface of the upper flange 12a. The weld rib 12f is welded to a peripheral edge of the lower casing component 20. The welding may be performed by hot plate welding, for example. However, the welding is not limited to this, and may be performed by vibration welding, for example.

[0047] As illustrated in FIG. 7, the peripheral wall 12 of the upper casing component 10 has, on its inner surface, a step portion 12d onto which the filter 2 is fitted. As illustrated in FIG. 4, the filter 2 is a plate-shaped one formed by injection-molding a resin material. The filter 2 has a mesh portion 2a for filtering oil which passes therethrough, a frame 2b surrounding the mesh portion 2a, and a plurality of reinforcement members 2c. The mesh portion 2a is made of the resin material and is meshed finely enough to filter oil. The frame 2b is fitted onto the step portion 12d on the inner surface of the peripheral wall 12 of the upper casing component 10. The outer peripheral surface of the frame 2b is entirely in contact with the inner surface of the peripheral wall 12 of the upper casing component 10. As illustrated in FIG. 5, the mesh portion 2a is located above the frame 2b. As illustrated in FIGS. 3 and 4, the frame 2b has a plurality of notches 2d which are arranged circumstantially and spaced from each other. The reinforcement members 2c are rod-like members which extend in longitudinal and transverse directions inside the frame 2b and are integral with the mesh portion 2a to reinforce the mesh portion 2a.

[0048] As illustrated in FIG. 4, the filter 2 has a curved plate portion 2e. The curved plate portion 2e is provided in a near side left corner portion in the frame 2b. As illustrated in FIG. 3, the curved plate portion 2e is positioned in a vicinity of the proximal end of the oil outlet cylinder 3b of the casing 3 in a state where the filter 2 has been mounted to the casing 3.

[0049] The curved plate portion 2e has no mesh portion, and the oil is not allowed to pass through the curved plate portion 2e.

[0050] As illustrated in FIGS. 5 and 8, the curved plate portion 2e of the filter 2 is curved smoothly so as to become lowered as it approaches the near side of the casing 3 in a state where the filter 2 has been mounted to the casing 3. The curved plate portion 2e is arranged such that its end located close to the near side is continuous with the lower wall of the oil outlet cylinder 3b. Further, another end, of the curved plate portion 2e, located close to the far side, is at the same height as, and continuous with, the mesh potion 2a.

[0051] The curved plate portion 2e having the thus curved shape and being formed at the filter 2 may introduce part of the oil, which is flowing in the flat portion 3a and is going to enter the oil outlet cylinder 3b, also to a lower portion of the oil outlet cylinder 3b.

[0052] As illustrated in, for example, FIG. 1, an extension potion 13 is provided on the peripheral wall 12 of the upper casing component 10. The extension portion 13 is provided to extend, in the width direction of the flat portion 3a, i.e., in the rightward direction in this embodiment, a flow passage cross section of the proximal end portion of the oil outlet cylinder 3b in the cylinder projecting direction. The extension portion 13 is provided on a portion, of the peripheral wall 12 of the upper casing component 10, located close to the near side and extending in the width direction, such that the extension portion 13 is adjacent to the right side of the oil outlet cylinder 3b. The extension portion 13 protrudes from a proximal end portion (an upper portion) of the peripheral wall 12 toward the outside of the upper casing component 10. Thus, the extension portion 13 is located downstream, in the oil flow direction, of the room, inside the flat portion 3a, where the filter 2 is housed, i.e., downstream of the filter housing room R. The extension portion 13 has a greater dimension in the width direction than in the vertical direction. A left part of the extension portion 13 is integral with a wall of the proximal end portion of the oil outlet cylinder 3b in the cylinder projecting direction. A right part of the extension portion 13 is located close to the right end of the casing 3.

[0053] The extension portion 13 includes therein a hollow space S which communicates with the proximal end portion of the oil outlet cylinder 3b in the cylinder projection direction. This hollow space S is long in the width direction, and a left portion of the hollow space S communicates with at least part of the portion, of the oil outlet cylinder 3b, in which the upper inclined wall portion 3e is provided.

[0054] As illustrated in FIG. 3, the peripheral wall 12 of the upper casing component 10 has, below the extension portion 13, i.e., near the distal end of the peripheral wall 12, a protrusion 15 which protrudes toward the outside of the casing 3. Like the extension portion 13, the protrusion 15 is long in the width direction. The protrusion 15 does not protrude as much as the extension portion 13. Thus, the distal end of the extension portion 13 in its protruding direction is located outward with respect to the distal end of the protrusion 15 in its protruding direction.

[0055] As illustrated in FIG. 7, a plurality of ribs 15a is formed in a distal end portion of the peripheral wall 12 of the upper casing component 10. These ribs 15a extend in the vertical direction inside the protrusion 15, and are spaced from each other in the width direction. That is to say, the ribs 15a are arranged directly under the extension portion 13. Upper and lower ends of each rib 15a are continuous with the inner surface of the protrusion 15. In this manner, the strength of the protrusion 15 is increased, and consequently, the strength of the peripheral wall 12 is increased. A single rib 15a may be provided.

[0056] As illustrated in FIG. 1, the peripheral wall 12 of the upper casing component 10 has a projecting plate portion 14 which projects toward the outside of the casing 3. The projecting plate portion 14 projects from the distal end of the extension portion 13 in the protruding direction, and is integral with the wall of the proximal end portion of the oil outlet cylinder 3b.

[0057] As illustrated in FIG. 2, the lower casing component 20 has the lower wall 21 which covers a lower opening of the upper casing component 10. The lower casing component 20 further includes a peripheral wall 22 extending upwardly from a peripheral edge of the lower wall 21. A lower flange 22a which projects toward the outside of the casing 3 extends circumstantially on an upper end portion of the peripheral wall 22. The lower flange 22a and the upper flange 12a face each other and are spaced from each other in the vertical direction. The lower flange 22a has a plurality of jig engagement portions 22b curving downward. The jig engagement portions 22b of the lower flange 22a are at the same location as the jig engagement portions 12b of the upper flange 12a in the circumstantial direction of the casing 3. A weld rib 22f illustrated in FIG. 1 extends over the entire periphery of an upper surface of the lower flange 22a. The weld rib 22f is welded to the weld rib 12f of the upper casing component 10, thereby joining the upper and lower casing components 10 and 20 together in a fluid-tight manner.

[0058] Next, it is described how the thus configured oil strainer 1 is fabricated. First, a filter 2 is fitted onto a step portion 12d of an upper casing component 10 such that the filter 2 becomes integral with the upper casing component 10. Thereafter, the upper casing component 10 and a lower casing component 20 are each held by a weld jig such that the openings of the upper and lower casing components 10 and 20 face each other. A hot plate is inserted between the upper and lower casing components 10 and 20 to heat the casing components 10 and 20. In this heating process, although the filter 2 is also heated, the curved plate portion 2e, which is the portion placed closer to the hot plate than any other portion of the filter 2 is, does not has a mesh structure, and therefore, the filter 2 of the present disclosure is more resistant to melting than in a case where the curved plate portion 2e has a mesh structure.

[0059] After the weld rib 12f of the upper casing component 10 and the upper end portion of the peripheral wall 22 of the lower casing component 20 have molten, the hot plate is removed and the weld rib 12f of the upper casing component 10 is brought into contact with, and welded to, the weld rib 22f of the peripheral wall 22 of the lower casing component 20. In this manner, the oil strainer 1 is fabricated. When the weld rib 12f of the upper casing component 10 is brought into contact with the weld rib 22f of the peripheral wall 22 of the lower casing component 20, vertical compressive force acts on the peripheral wall 12 of the upper casing component 10. In this embodiment, since the peripheral wall 12 of which the strength is reduced by the formation of the extension portion 13 is reinforced by the ribs 15a formed in the protrusion 15, a warp which could occur in the peripheral wall 12 may be reduced. As a result, the weld rib 12f of the upper casing component 10 may be tightly pressed onto the weld rib 22f of the peripheral wall 22 of the lower casing component 20. Thus, the upper casing component 10 may be reliably welded to the lower casing component 20, and a decrease in the weld strength may be substantially prevented.

[0060] Since the oil strainer 1 fabricated in the above-described manner houses the filter 2 in the flat portion 3a that is flat in the horizontal direction, the oil strainer 1 may be thin. As a result, the oil strainer 1 may be arranged in a thin oil pan, and at the same time, interference with various parts arranged in the oil pan may be prevented. Further, the filter 2, which is housed in the flat portion 3a, has a sufficient effective filtration area, thereby enhancing the filtration capability.

[0061] After having entered the filter housing room R of the flat portion 3a through the oil inlet opening 5, the oil passes through the mesh portion 2a of the filter 2 to be filtered, while flowing upwardly toward the near side. Thereafter, the oil flows into the oil outlet cylinder 3b. Here, since the proximal end portion of the oil outlet cylinder 3b has a flow passage cross section extended due to the formation of the extension portion 13, even if the cross-sectional shape of the flat portion 3a significantly differs from that of the oil outlet opening 4, the presence of the extension portion 13 provided between the flat portion 3a and the oil outlet opening 4 makes the abrupt change in the cross-sectional shape gradual. As a result, the oil is allowed to flow smoothly from the flat portion 3a to the oil outlet opening 4, and flow resistance of the oil decreases.

[0062] Further, the extension portion 13 is located downstream, in the oil flow direction, of the filter housing room R, and has the hollow space S which communicates with the proximal end portion of the oil outlet cylinder 3b in the cylinder projecting direction. This configuration allows the oil to flow even more smoothly from the flat portion 3a to the oil outlet opening 4.

[0063] Note that although the oil outlet cylinder 3b of this embodiment projects from a left portion of the flat portion 3a, the oil outlet cylinder 3b may project from a central portion in the width direction or a right portion of the flat portion 3a. If the oil outlet cylinder 3b projects from the central portion in the width direction of the flat portion 3a, an extension portion is provided on each of the left and right sides of the oil outlet cylinder 3b (not shown).

[0064] In this manner, the flow passage cross section of the proximal end portion of the oil outlet cylinder 3b may be extended toward the left and right ends in the width direction of the flat portion 3a. If the oil outlet cylinder 3b projects from a right portion of the flat portion 3a, an extension portion is formed on the left side of the oil outlet cylinder 3b (not shown). In this manner, the flow passage cross section of the proximal end portion of the oil outlet cylinder 3b may be extended in the leftward direction of the flat portion 3a.

[0065] In the embodiment described above, the flat portion 3a of the oil strainer 1 extends in the horizontal direction. However, the flat portion 3a is not limited to this shape, and may extend in the vertical direction.

[0066] The above-described embodiment is illustrative only and should not be interpreted in any way to limit the present disclosure. All variations and modifications within a scope equivalent to the scope of the claims are encompassed in the scope of the present disclosure.

[0067] As described above, the oil strainer of the present disclosure is useful in an oil pan of an engine or an automatic transmission mounted in an automobile, for example.