Preferred embodiments of the invention will be described below with reference to the accompanying drawings. An oil filter (described later) is an embodiment adapted to an oil filter of an automobile engine.
With reference to
The base 4 includes a cylinder (tubular portion) 4a. The cylinder 4a includes a female screw 4b formed in the inner circumference and a male screw 5b formed on the end of a fitting portion 5a of the cap 5. The female screw 4b is screwed with the male screw 5b, thus connecting the cap 5 and the base 4 to each other. The cap 5 includes an O-ring 7 serving as seal means fitted to the outer circumference of the fitting portion 5a. The O-ring 7 tightly contacts the inner circumference of the cylinder 4a, thereby sealing the joint portion of the cap 5 and the base 4. The cap 5 has, between the top and the bottom thereof, a flange 5c abutting against the end surface of the cylinder 4a, thereby positioning the cap 5 in the axial direction of the cylinder 4a.
The base 4 defines an inlet port 12 and an outlet port 13 each having one end opened to a mounting surface 4c and the other end extending in a direction orthogonal to the axis of the cylinder 4a. When the base 4 is connected to, for example, the engine block of a vehicle, the mounting surface 4c tightly contacts the connected surface of the engine block. The inlet port 12 is connected to a discharge port for discharging oil from the engine. The outlet port 13 is connected to a feeding port led to a lubrication position of the engine.
The base 4 includes a fitting tube 8 inside thereof. The fitting tube 8 is positioned coaxially with the cylinder 4a. The fitting tube 8 includes an oil-introduction channel 15 located on the outer circumference and communicating with the inlet port 12. Meanwhile, an oil-feeder channel 16 functioning as an oil channel is formed below the fitting tube 8. The oil-feeder channel 16 communicates with the outlet port 13 and linearly extends downward, coinciding with the cylinder 4a in axis. The interior of the fitting tube 8 is slightly larger in inner opening diameter than the oil-feeder channel 16. The interior of the fitting tube 8 communicates with the oil-feeder channel 16, with a stepped portion 9 placed therebetween. The oil-introduction channel 15 is formed in the base 4 as an annular groove surrounding the oil-feeder channel 16. The oil-feeder channel 16 functions as the oil channel. The fitting tube 8 functions as a holding portion.
The oil-feeder channel 16 includes a drain channel 17 formed below the oil-feeder channel 16, coinciding with the oil-feeder channel 16 in axial direction, and extending in the axial direction of the cylinder 4a. The drain channel 17 communicates with the oil-feeder channel 16 and discharges the oil inside the filter case 2 to the outside of the oil filter 1. The drain channel 17 communicates with an oil pan of the engine.
The filter element 3 contained in the filter case 2 is formed into a generally tubular shape as a whole by folding a filtering member of a paper filter into continuous peaks and troughs so that the peaks and the troughs are alternately aligned circumferentially. Both axial ends of the filter element 3 are bonded to a seal plate 28 using, for example, an adhesive agent. The seal plate 28 is made of a material, e.g., a paper filter or an unwoven fabric, having a filtering function similarly to the filtering member. The filter element 3 is positioned coinciding with the cylinder 4a in axis.
The filter element 3 includes an inner tube 31 fitted to the inner circumference of the filter element 3. The inner tube 31 includes an inner-tube extension 36 joined to the lower end of the inner tube 31. The inner-tube extension 36 is movable in the axial direction of the cylinder 4a with respect to the inner tube 31. The upper end of the inner-tube extension 36 is engaged with the stepped portion 9. The lower portion of the inner-tube extension 36 is inserted in the oil-feeder channel 16. The joint portion having the inner tube 31 and the inner-tube extension 36 joined each other is fitted in the fitting tube 8 for holding. As shown in
The inner tube 31 includes a pair of tubes 32 and 33 arranged on the both ends, respectively. The inner tube 31 includes, for example, four longitudinal ribs 34 extending in the axial direction to connect the tubes 32 and 33 to each other. The inner tube 31 includes ring-shaped transverse ribs 35 arranged at substantially equal intervals between the tubes 32 and 33.
The inner-tube extension 36 includes the engagement portion 37 arranged on the outer circumference of the upper end of the inner-tube extension 36 and engaged with the stepped portion 9. The inner-tube extension 36 includes a spindle 38 extending in the axial direction of the lower cylinder 4a. The spindle 38 includes an O-ring 39 serving as a seal member fitted to the outer circumference of the lower end of the spindle 38. The O-ring 39 tightly contacts the inner circumference of the lower end of the oil-feeder channel 16.
Normally, the oil-feeder channel 16 does not communicate with the drain channel 17 because the O-ring 39 tightly contacts the inner circumference of the lower end of the oil-feeder channel 16. On the other hand, during replacement of the filter element 3 with a new filter element 3, the inner-tube extension 36 is pulled out upward. Therefore, the oil-feeder channel 16 communicates with the drain channel 17. At the time of communication therebetween, the oil contained in the filter case 2 is returned to the oil pan via the drain channel 17.
The upper end of the inner-tube extension 36 includes a sliding member 41 extending upward along the axis of the cylinder 4a. The sliding member 41 slides on the inner circumference of the tube 33 provided on the lower end of the inner tube 31. The sliding member 41 has a distal end with a pawl 42. The pawl 42 is arranged in a groove 33a formed above the tube 33 provided on the lower end of the inner tube 31. The pawl 42 is engaged with the upper end of the tube 33 for assembly, thereby preventing both the pawl 42 and the tube 33 from coming off from each other in the axial direction of the cylinder 4a.
The upper end of the inner-tube extension 36 is formed in a circular shape. The sliding member 41 is arranged on the circumference of the circular upper end of the inner-tube extension 36. The inner circumferential surface of the tube 33 functioning as a ring portion according to the embodiment of the invention is fitted in the outer circumference of the sliding member 41. The sliding member 41 functions as a sliding portion. The tube 33 functions as a ring portion.
The tube 33 is movably held between the lower end of the sliding member 41, i.e., the upper end of the engagement portion 37 of the inner-tube extension 36 and the pawl 42 on the upper end of the sliding member 41 for restricting movement of the tube 33. Likewise, the movement of the inner-tube extension 36 is restricted. The pawl 42 and the engagement portion 37 act as stoppers restricting movement between the inner tube 31 and the inner-tube extension 36.
The inner tube 31 and the inner-tube extension 36 are movable in the axial direction of the cylinder 4a by mutual sliding of the tube 33 provided on the lower end of the inner tube 31 and the outer circumferential surface of the sliding member 41 of the inner-tube extension 36.
The sliding member 41 is made of an elastically deformable material. The distal end of the sliding member 41 is deformed in the radial direction of the tube 33 with respect to the proximal end of the sliding member 41. The pawl 42 on the distal end of the sliding member 41 is elastically deformed and arranged on the groove 33a above the tube 33. The pawl 42 is engaged with the upper end of the tube 33, thereby allowing the inner tube 31 and the inner-tube extension 36 to be detachable and attachable. This structure allows the inner-tube extension 36 to be joined to the inner tube 31 with one touch, and thus facilitates joining of the inner-tube extension 36 to the inner tube 31.
The upper end of the inner tube 31 includes a valve seat member 50. The valve seat member 50 has a fitting portion 51 positioned on the lower end, the fitting portion 51 being fitted into the outer circumference of the tube 32 positioned on the upper end of the inner tube 31. The valve seat member 50 includes a filter presser 52 extending circumferentially and larger in diameter than the fitting portion 51.
If the inner tube 31 is inserted into the cylinder 4a and thrust into the base 4 with the inner tube 31 being fitted to the cap 5, then the valve seat 50 tightly contacts the seal plate 28, and the filter element 3 is pushed in the axial direction of the cylinder 4a. As a result, the filter element 3 is held between the end surface of the fitting tube 8 and the filter presser 52 of the valve seat member 50, being positioned coaxially with the cylinder 4a. The inner circumferential side and the outer circumferential side of the filter element 3 are thereby liquid-tightly sealed from each other, thus separating the interior of the filter case 2 into a dirty side S1 and a clean side S2.
The valve seat member 50 includes a through-hole 53 at the center of the fitting portion 51. The valve seat member 50 includes a relief valve 55. The relief valve 55 is provided movably in the axial direction of the cylinder 4a. The relief valve 55 includes a valve 57 abuttable with the opening of the lower end of the through-hole 53. The relief valve 55 includes a valve support member 58 extending upward via the inner circumferential surface of the through-hole 53 of the valve member 50. The relief valve 55 includes pawl 59 formed on the distal end of the valve support member 58. The relief valve 55 includes coil spring 60 provided on the respective pawl 59 and on a spring shoe 54 provided on the upper end of the valve seat member 50. The coil spring 60 urges the valve 57 toward the opening of the lower end of the through-hole 53. If a pressure difference between the dirty side S1 and the clean side S2 is within a predetermined value, the through-hole 53 formed in the valve seat member 50 is closed by the valve 57. If a pressure of the clean side S2 rises to be equal to or higher than a predetermined value, the valve 57 separates from the valve seat member 50, thereby opening the through-hole 53. The opened through-hole 53 releases the pressure from the clean side S2 to the dirty side S1.
The upper end of the valve seat member 50 includes a support 67 that is engaged with the pawl 5a extending downwardly from the upper end of the cap 5. The support 67 urges the valve seat member 50 downwardly in the axial direction of the cylinder 4a using a coil spring 65. The support 67 includes an opening 67a formed on the side surface of the valve seat member 50. The opening 67a allows the oil flowing from the through-hole 53 formed in the valve seat member 50 to flow into the dirty side S1. The oil flowing from the clean side S2 into the dirty side S1 through the opening 67a returns again to the clean side S2 through the filter element 3.
In the oil filter 1 described above, the inner tube 31 and the inner-tube extension 36 are fitted into the cap 5, with the support 67, the relief valve 55, and the valve seat member 50 located in the cap 5. The inner tube 31 and the inner-tube extension 36 together with the filter element 3 are inserted into the base 4. Thereafter, the cap 5 is thrust into the base 4 until the flange 5c abuts against the cylinder 4a of the base 4. As a result, the oil filter 1 illustrated in
In the assembly illustrated in
When the vehicle engine is started and the pressurized oil is introduced to the inlet port 12 in this state, the oil flows into the dirty side S1. The oil radially passes through the filter element 3 and flows into the clean side S2 through the clearances of the inner tube 31. Further, the oil is introduced to a predetermined lubrication position through the oil-feeder channel 16 and the outlet port 13. At this time, oil-caused pressure is applied to the lower end of the inner-tube extension 36, thereby pulling out the inner-tube extension 36 downward. On the other hand, as shown in
When the engine is stopped and the pressure of the oil introduced into the inlet port 12 falls, the dirty side S1 and the clean side S2 enclose the oil therein. In this state, the cap 5 is loosened so as to remove the filter element 3. The support 67, the relief valve 55, the valve seat member 55, the inner tube 31, and the inner-tube extension 36 fitted to the cap 5 are separated from the base 4 to follow the loosening of the cap 5. Accordingly, the oil-feeder channel 16 communicates with the drain channel 17, thereby returning the oil contained in the base 4 to the oil pan of the engine.
After removing the cap 5, pulling of the filter element 3 off permits only the used filter element 3 to be disposed. A new filter element 3 is arranged in the base 4. The inner tube 31 and the inner-tube extension 36 fitted to the cap 5 are inserted into the inner circumferential side of the filter element 3 for assembly, thus fitting the cap 5 to the base 4.
The invention is not limited to the embodiment described above and is carried out in various manners. For example, the invention is not limited to the oil filter used in the vehicle engine but also applicable to various oil filters such as a working fluid filter used in an automatic transmission. The sliding member 41 is arranged on the inner circumference of the tube 33a. While, the sliding member 41 may be arranged on the outer circumference of the tube 33a. In this alternative, the pawl 42 on the distal end of the sliding member 41 is arranged to direct inward. In another alternative, the sliding member 41 may be provided in the inner-tube extension 36 and the tube 33 sliding on the sliding member 41 may be provided in the inner tube 31. In still another alternative, the sliding member 41 may be provided in the inner tube 31 and the tube 33 sliding on the sliding member 41 may be provided in the inner-tube extension 36. In this alternative, the members that function as stopper restricting movement of the tube 33 may be provided on the upper and lower both ends of the sliding member 41, respectively.
Although the invention has been described above by reference to certain embodiments of the invention, the invention is not limited to the embodiments described above. Modifications and variations of the embodiments described above will occur to those skilled in the art, in light of the above teachings. The scope of the invention is defined with reference to the following claims.
Number | Date | Country | Kind |
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2006-247689 | Sep 2006 | JP | national |