JPH11276814A - Oil filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the adhesion of the crest parts of filter paper to each other in the use of a filter element in which the pleated filter paper is rounded into an annulus ring. SOLUTION: The diameter of the end part of an inner cylinder 17 to be put into a filter element 4 is decreased, and the position of a valve holding part 17c at the tip of small-diameter part 17b is arranged to be inside sufficiently from the position of an oil inflow hole 10. The diameter D of the general part 17a of the inner cylinder 17 and the inside diameter of the filter element 4 are enlarged in relation to the diameter (d) of the part 17b to prevent the adhesion of the crest parts of filter paper which forms the filter element 4 to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cartridge type oil filter used for an internal combustion engine, and more particularly to a structure around a check valve for preventing drain back, which is housed in a case together with a filter element.

[0002]

2. Description of the Related Art An example of this type of oil filter is disclosed in Japanese Patent Publication No. 7-114892. As shown in FIG. 7, an inner cylinder 53 serving as a protector is inserted into the inner periphery of an annular filter element 52 housed in a case 51, and a substantially V-shaped valve holding portion 54 is attached to the tip of the inner cylinder 53. The check valve 56 for preventing the drain back is clamped and fixed between the valve holding portion 54 and the cover plate 55 closing the open end of the case 51 itself.

[0003]

In the structure shown in FIG. 7, when the filter element 52 is of a type in which pleated filter paper is rolled into an annular shape, the inner and outer diameters of the filter element 52 are on the inner peripheral side. Due to the difference, the ridges (tops) of the pleated filter paper approach or adhere to each other to increase the filtration resistance. Therefore, in order to suppress the filtration resistance, the inner diameter of the filter element 52, that is, the filter element It is desirable that the diameter of the inner cylinder 53 inserted into the inner periphery of the cylinder 52 is somewhat large.

On the other hand, a plurality of oil inflow holes 57 are formed in the cover plate 55, and these oil inflow holes 57 are formed.
By clamping the base of the valve 56 between the cover plate 55 and the valve holding portion 54 on the inner cylinder 53 side at a position further inside, the inside and outside of the inner cylinder 53 are sealed. Separates oil before and after filtration. However, when the diameter of the inner cylinder 53 is increased in order to respond to the demand for increasing the inner diameter of the filter element 52 as described above, the valve holding portion 54 formed in the inner cylinder 53 necessarily includes the oil inflow hole 57.
, And there is naturally a limit in increasing the diameter of the inner cylinder 53.

[0005] Therefore, in the conventional structure, when it is assumed that a filter element obtained by pleating a filter paper and rolling the filter paper into an annular shape is used, it is necessary to increase the diameter of an inner cylinder inserted into the inner periphery of the filter element. Therefore, there is still room for improvement in reliably preventing the above-mentioned peaks of the filter paper from adhering to each other.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and avoids the above-described positional interference between the seal position and the oil inflow hole, while also preventing the above-described inner diameter of the filter element and, hence, the inner cylinder inserted therein. An object of the present invention is to provide a structure capable of ensuring a sufficiently large diameter.

[0007]

According to the present invention, an annular filter element and a filter element are provided between a cup-shaped case and a cover plate for closing an open end of the case. An oil filter having a structure in which a concentric check valve for preventing drain back adjacent to the element and a check valve are held with the check valve being on the cover plate side, the leaf being mounted on the inner bottom of the case. A filter element formed by rolling a spring and a pleated filter medium into an annular shape, and having an end plate attached to each end face of the filter element so as to protrude toward the inner diameter side of the filter medium; And one end of the filter element projects from the end plate on the cover plate side of the filter element. While, the other end and a cylindrical inner which abuts the end plate of the leaf-spring-side of the filter element.

[0008] At least a portion of the one end of the inner cylinder protruding from the end plate of the filter element is made smaller in diameter than the other portion, and a curling process is applied to the tip of this small diameter portion to form a valve holding portion. The end plate on the leaf spring side of the filter element is pressed against the leaf spring, and the check valve is clamped and fixed between the valve holding portion and the cover plate by the spring force of the leaf spring. And

Therefore, according to the present invention, a valve holding portion is formed by curling at the end of a portion of the inner cylinder inserted into the filter element that protrudes from the filter element, and the valve holding portion and the cover plate form Although it is basically the same as the conventional structure in that the inside and outside of the inner cylinder are sealed by sandwiching the check valve for preventing drain back, the diameter of the portion of the inner cylinder that protrudes from the filter element is By making the diameter relatively small, it is possible to easily cope with the difference between the diameter of the inner cylinder required on the filter element side and the diameter of the inner cylinder required on the seal portion side with only a single inner cylinder. Become. The diameter of a portion of the inner cylinder inserted into the filter element can be set arbitrarily, and the inner diameter of the filter element itself can be made as large as possible.

Further, the pressing force (spring force) of the leaf spring is reliably transmitted to the base of the check valve via the end plate on the leaf spring side of the filter element, and is clamped and fixed between the valve holding portion and the cover plate. The sealing performance at the base of the check valve is further improved.

[0011]

According to the present invention, the diameter of the portion of the inner cylinder inserted into the filter element, which protrudes from the filter element and becomes the valve holding portion, is made smaller than that of the other portions. Since the diameter of the portion to be inserted into the filter element can be relatively increased while satisfying the diameter required for the (sealing portion), the inner diameter of the filter element can be set to a necessary and sufficient size, As a result, there is an effect that the pleated folded filter medium is prevented from adhering to each other and the filter performance can be maintained for a long time.

Further, the pressing force of the leaf spring is reliably transmitted to the base of the check valve via the end plate on the leaf spring side of the filter element, and is fixed by the valve holding portion and the cover plate. In addition to further improving the sealing performance at the base of the check valve, the end plates on both end faces of the filter element can be shared with each other. Is eliminated, and there is an effect that the number of man-hours for parts management and the manufacturing cost can be reduced.

[0013]

1 and 2 show a preferred embodiment of the present invention. An oil filter 1 is roughly divided into a cup-shaped case 2 and an open end of the case 2 which is closed. A cover plate 3 having a substantially funnel shape, a filter element 4 housed between the case 2 and the cover plate 3, and a check valve 5 for preventing drain back.

A short leaf spring 6 is inserted in the inner bottom of the case 1 in advance, and one end plate 14 of a filter element 4 described later is engaged with a stepped portion 7 of the leaf spring 6. Thus, the filter element 4 and the check valve 5 are held between the case 2 and the cover plate 3 with the check valve 5 facing the cover plate 3.

A flange plate 8 is fixed to the cover plate 3 in advance by welding so as to overlap with the cover plate 3. By curling the outer periphery of the flange plate 8, the cover plate 3 fixes the flange plate 8. The seal rubber 9 is held by simultaneously performing curling on the inner peripheral side of the flange plate 8. A plurality of oil inflow holes 10 are formed in the cover plate 3 at equal pitches, and an oil outflow hole 13 having a boss portion 11 and a female screw portion 12 at the center thereof is formed.

As shown in FIG. 2, the filter element 4 is formed into an annular shape by rolling a pleated filter paper, and has an annular end plate 14 made of thick filter paper on both end surfaces. Or 15 is stuck.

The inner periphery of the filter element 4 is press-fitted with a pipe-shaped inner cylinder 17 formed by roll-forming a steel plate having a number of holes 16 formed by punching. The end face on the spring 6 side is abutted against the end plate 14, and the end on the opposite side of the cover plate 3 is a filter element 4.
Among the end plates 15 on the cover plate 3 side. At the end on the cover plate 3 side of the inner cylinder 17, the diameter d is reduced by drawing to a diameter D of the general portion 17 a over a predetermined length, and the other end plate 15 is attached to the small diameter portion 17 b. Are inscribed, and a valve holding portion 17c is formed at the tip of the small diameter portion 17b by performing a curling process.

On the other hand, the check valve 5 is formed in a substantially funnel shape with silicone rubber or the like, and is mounted so as to cover the boss portion 11 of the cover plate 3 on which the female screw portion 12 is formed. Thereby, each oil inlet hole 10 is covered with the valve body 5a. As shown in FIG. 3, a plurality of ribs 18 project radially from the valve body 5 a of the check valve 5, and a valve holder 17 on the inner cylinder side is provided on the base 19.
A groove 20 having a substantially semicircular cross-section for engaging with c is formed, and a lip 21 is protruded. Then, the pressing force of the leaf spring 6 acts on the valve holding portion 17c via the end plate 14 and the inner cylinder 17, and the base portion 19 of the check valve 5 is formed by the valve holding portion 17c engaged with the groove 20 and the cover plate 3. Are held to seal the inside and outside of the inner cylinder 17, and the lip 21 is pressed against the end plate 15.

Therefore, according to the oil filter 1 of the present embodiment, the check valve 5 is opened when the oil flows from the oil inflow hole 10 at a predetermined pressure as a basic function.
After the oil passes through the filter element 4, the inner cylinder 17
Through the hole 16 to the inside of the inner cylinder 17 and the oil outflow hole 1
Spill out of 3. When the pressure of the oil increases due to clogging of the filter element 4 or the like, the oil passes directly through the relief valve 22 attached to the leaf spring 6 without passing through the filter element 4.
7 flows into. That is, when the pressure of the oil becomes larger than the pressure set by the coil spring 23, the valve body 24 of the relief valve 22 is pushed down and the inner cylinder 1 is opened from the opening 25.
7 flows into.

As described above, since the diameter D of the general portion 17a of the inner cylinder 17 is larger than the diameter d of the small diameter portion 17b, the filter element 4 into which the general portion 17a is press-fitted. The inner diameter D is also made larger than before in accordance with that. As a result, the position of the seal portion formed by sandwiching the check valve 5 between the valve holding portion 17c and the cover plate 3 is kept inside the position of each oil inflow hole 10 while the position of the inner cylinder 17 is maintained. The contradictory requirement that the diameter D of the general portion 17a and thus the inner diameter D of the filter element 4 be larger than the diameter d of the seal portion is realized by only the single inner cylinder 17. As a result, as shown in FIG. 2, the ridges 4a on the inner side of the pleated filter paper do not adhere to each other, and the original filter performance can be maintained for a long time.

As is apparent from FIG. 1, the edge 17d of the valve holding portion 17c and the tip of the base portion 19 of the check valve 5 are flush with each other so that the heights of the two are uniform. In addition to preventing the check valve 5 from cracking or breaking due to the portion 17d, the load required for the leaf spring 6 (while absorbing the dimensional error of the filter element 4 by pressing the lip 21 against the end plate 15). (Elastic force) can be relatively reduced.

In addition, both end plates 14 and 15 adhered to both end surfaces of the filter element 4 can be of the same size, and both end plates 14 and 15 can be used in common.

FIG. 4 is a view showing a second embodiment of the present invention. As is apparent from comparison with FIG. 1, the amount of entanglement of the valve holding portion 27 formed by curling is increased. The edge 27a faces inward. Thereby, the edge portion 27 of the valve holding portion 27
There is an advantage that it is possible to more reliably prevent the check valve 5 from being cracked due to a.

FIG. 5 shows a third embodiment of the present invention. As apparent from comparison with FIG. 1, the shapes of the cover plate 33 and the check valve 35 are changed. This is exactly the same as that shown in FIG.

Here, in the above-described first to third embodiments, as shown in FIG. 6, a bead having a substantially semicircular cross section along the circumferential direction is provided at two places of the general portion 17a of the inner cylinder 17. Part 28
May be formed as a bulge, and this bead portion 28 may be used as a pressure contact portion of the inner cylinder 17 against the filter element 4. By doing so, a predetermined gap G is secured between the filter element 4 and the inner cylinder 17, and the flow resistance of oil flowing from the filter element 4 through the hole 16 to the inner cylinder 17 can be reduced. In addition, there is an advantage that the rigidity of the inner cylinder 17 itself is increased.

[Brief description of the drawings]

FIG. 1 is a full sectional view showing a first embodiment of an oil filter according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1;

FIG. 3 is a perspective view of the check valve shown in FIG. 1;

FIG. 4 is an essential part cross-sectional view showing a second embodiment of the oil filter according to the present invention.

FIG. 5 is a half sectional view showing a third embodiment of the oil filter according to the present invention.

FIG. 6 is a half sectional view showing still another embodiment of the oil filter according to the present invention.

FIG. 7 is a half sectional view showing an example of a conventional oil filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Oil filter 2 ... Case 3 ... Cover plate 4 ... Filter element 5 ... Check valve 6 ... Leaf spring 10 ... Oil inflow hole 13 ... Oil outflow hole 14, 15 ... End plate 16 ... Hole 17 ... Inner cylinder 17a ... General Part 17b ... Small diameter part 17c ... Valve holding part 19 ... Base part 20 ... Groove part 21 ... Lip 27 ... Valve holding part 28 ... Bead part 33 ... Cover plate 35 ... Check valve

Claims (1)

[Claims] 1. An annular filter element and a concentric check valve for preventing drain back adjacent to the filter element are provided between a cup-shaped case and a cover plate for closing an open end of the case. An oil filter having a structure in which the check valve is sandwiched and held with the check valve facing the cover plate, and is formed by rolling a leaf spring mounted on the inner bottom of the case and a pleated filter medium into an annular shape. At the same time, a filter element having an end plate attached to both end faces thereof so as to project toward the inner diameter side of the filter medium, and a plurality of holes formed in the cylindrical surface while being inserted into the inner periphery of the filter element. One end protrudes from the end plate on the cover plate side of the filter element, and the other end An inner cylinder abutted against the end plate on the side of the leaf spring, wherein at least a portion of one end of the inner cylinder protruding from the end plate of the filter element has a smaller diameter than the other portion, and A curling process is performed on the tip of the filter element to form a valve holding portion.The end plate on the leaf spring side of the filter element is pressed against the leaf spring, and the valve holding portion and the cover plate are formed by the spring force of the leaf spring. An oil filter characterized in that a check valve is clamped and fixed between them.