JPH076375B2 - Filter element - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter element, and more particularly to a filter element in which an oil filter for an internal combustion engine or the like is used for an air cleaner or the like.

(Prior Art) An oil filter of an internal combustion engine removes dust mixed in circulating oil, and an air cleaner supplies dust from the air to supply clean air to a cylinder. Is for removing.

The oil filter and the air cleaner usually have a structure in which a cartridge type filter element formed by bending a paper is contained in an airtight container made of metal.

The conventional oil filter 20, as shown in FIG.
It comprises a filter element 22 housed in an oil filter case 21, a bottom cover 24 supporting the filter element 22, and a reinforcing inner cylinder 25 of the element.

As shown in FIGS. 7 and 8 (FIG. 7 is a perspective view, FIG. 8 is a plan view), the filter element 22 is formed by winding a paper sheet having folds folded in a mountain shape into a cylindrical shape. The cross section is composed of chrysanthemums, and both ends thereof are seal-bonded by plates 23a and 23b made of iron plates. The plates 23a and 23b are processed into a plate shape by press working, and then an adhesive is applied to the internal joints to join the both ends of the filter element 22.

Therefore, the overaction of the oil filter having the filter element configured as described above is shown in FIG. 6 in which the oil sucked from the oil intake port 24 _i formed in the bottom cover 24 of the oil filter 20 is indicated by the arrow mark. Check valve 26
Through the oil filter case 21. Then, the oil flows from the outer end side on the side of the filter element 21 toward the inner end side, passes through the filter element 22, and flows into the center side of the oil filter case 21. At this time, the umbrella by the filter element 22, clean oil dust has been removed is sent to the lubrication process from the oil outlet 21 _o of the lower oil filter.

(Problems to be Solved by the Invention) However, in the filter element formed in the chrysanthemum shape as described above and the plates are adhered to both end portions thereof, as shown by arrows in FIGS. Since the superfluid can only flow from the side of the element, the flow rate of the superfluid gradually increases as the superfluid gradually narrows as it enters from the outer end side of the element to the inner end side of the element. On the contrary, there is a problem that the pressure of the fluid to be superposed continues to decrease, that is, the resistance of the flow path becomes high, and the pressure loss of the superfluid becomes high. Moreover,
Since the flow velocity in each part of the element is not uniform, there is a problem that the flow resistance applied to the element paper is not uniform, and the flow velocity partially passing through the paper is different so that it cannot be uniform.

Further, in the chrysanthemum-shaped filter element as described above, the formation of the chevron-shaped folds is radial from the center as shown in the plan view of FIG.
The distance W between the pleats formed on the outer end side becomes wider as the diameter of the outer cylinder of the filter element increases. Therefore, there is a problem that it is not possible to increase the excess area in which a large number of pleats can be formed. Also, when trying to reduce the diameter of the inner cylinder of the filter element to increase the excess area, it is not possible to increase the number of folds of the interleaving paper due to the interference of the folds formed on the inner end side, and eventually the excess area is increased. Can not do it.

The conventional filter element, which is formed into a chrysanthemum shape and in which the fluid to be infiltrated radially inflows from the side of the element, has various problems as described above. A filter element that flows in the axial direction from one end face of the element toward the other end face has been proposed (September, 1986 by the same applicant as the present applicant).
Application on 17th). This element has a structure in which a filter element formed by winding a paper sheet having a large number of pleats into a tubular shape is formed by joining surfaces of the pleats, which are located on the inner side of both ends of the element, to each other.

However, in the above-mentioned proposed filter element, when the fluid to be passed over flows into the filter element, the area of the flow path sharply decreases, so that the fluid is sharply narrowed. Therefore, there is a problem that the flow path resistance increases and a contraction flow occurs to cause a pressure loss.

The present invention has been made in view of the above circumstances, and an object of the present invention is to avoid an increase in flow path resistance and prevent contraction from occurring when a fluid to be flowed into a filter element. An object of the present invention is to provide a filter element capable of preventing pressure loss of fluid.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a filter element formed by winding a paper having a large number of pleats into a tubular shape, and A funnel-shaped portion is formed between the adjacent folds such that the surfaces located on the inner side are joined to each other and the surfaces located on the outer side of the adjacent folds are axially closer to each other from the joining surface. It is a thing.

(Operation) According to the present invention, by the above-mentioned means, the superfluous fluid flows in from one end face wound in a cylindrical shape, and at the time of this inflow, a contraction flow is generated in the fluid by the funnel-shaped portion formed between the adjacent folds. Can be prevented. Then, through this funnel-shaped portion, a uniform flow velocity flows in the axial direction from one end surface of the element to the other end surface, and the fluid to be passed passes from the outer side to the inner side of the element during this axial flow. To be passed. Therefore, it is possible to reduce the pressure loss compared to the conventional element in which the excess fluid flows in from the side of the element and flows in from the outer end side to the inner end side, and the uniform flow velocity in each part of the filter element It is possible to evenly pass over and improve over-efficiency.

(Embodiment) An embodiment of the filter element according to the present invention will be described below with reference to FIGS. 1 to 5.

FIG. 1 is a cross-sectional view of an oil filter. The oil filter 1 includes an oil filter case 2, a filter element 3 housed in the oil filter case 2, and a bottom cover 8 that supports the filter element 3. And a reinforcing inner cylinder 9 of the element.

As shown in FIG. 2, the filter element 3 is formed by bending a sheet of paper to form a large number of pleats 4 and winding it in a tubular shape. Then, at both ends of the tubular filter element, the sealing portions 5 are formed by joining the surfaces of the pleats 4 located inside the filter element to each other. This joining is performed by superposing ultrasonic waves on the facing surfaces of the pleats 4 or ultrasonically, or by interposing an adhesive on the bonding surfaces.

On the other hand, at both ends of the element, as shown in FIG. 4, funnel-shaped portions 6 are formed between the adjacent folds so that the outer surfaces of the adjacent folds are axially closer to each other from the joint surface. To do. The funnel-shaped portion 6 is formed to have substantially the same curvature as the natural streamline of the fluid.

Further, each fold 4 formed radially is formed. The pair of corrugated surfaces 4a, 4a are corrugated as shown in the enlarged cross-sectional view of FIG. 5, and the height h of this corrugation is from the inner end side to the outer end side of the element. It is set so as to gradually increase as it goes, and the pitch p thereof is set to be constant. The wave pitch p can be increased from the inner end side to the outer end side of the element.

Then, since the pair of pleated surfaces 4a, 4a of each pleats 4 are corrugated so as to project to the outer surface of the paper, even if the pleats 4 are joined at both ends of the element 3, the inner surfaces of the paper are mutually It can prevent close contact.

In the filter element 3 configured as described above,
Small-diameter plates 7 and 7 are adhesively sealed to the inner ends of both ends of the element to fill the gap on the inner side of the element.

Next, the operation of the filter element according to the present invention constructed as described above will be described.

In FIGS. 1 and 2, the oil sucked from the oil intake port 8 _i formed in the bottom cover 8 of the oil filter 1 flows into the oil filter case 2 through the check valve 10 as shown by the arrow. . As shown by the arrow in FIG. 1, the oil flows upward from below on the element outside of the filter element 3, and the oil passes through the filter element 3 during the upward flow from below to the element. Flows into the inside of the. At this time, the umbrella by the filter element 3, clean oil dust has been removed is sent to the lubrication process from the oil outlet 2 _o of the lower oil filter.

Therefore, in the filter element 3 of the present embodiment, the excess fluid flows axially from the lower side to the upper side of the element, passes through the element during this axial flow, and is passed inside the element. . Therefore, the inflow port of the fluid to be passed over the entire annular end surface of the element 3, the inflow port area is extremely large, and the fluid to be inflowed from the lower end surface of the element 3 flows along the axial direction of the element. The flow velocity is uniform and there is no pressure loss.

Further, a funnel-shaped portion 6 is formed at the inflow port portion 3 _i at the lower end portion of the filter element 3, that is, the funnel-shaped portion 6 is formed.
Is formed with almost the same curvature as the natural streamline of the fluid, and the fluid is gradually squeezed by the funnel-shaped portion 6 and the pressure loss at the time of inflow of the element can be minimized without contraction. .

Further, each pleated surface 4a of the filter element 3 is corrugated, and the wave height h in corrugation is increased from the inner end side to the outer end side of the element to increase the excess area. ing. That is, in a chrysanthemum-shaped element, the distance between the adjacent folds becomes wider from the inner side to the outer side in the radial direction of the element. Can be big. The corrugated surface 4a of the filter element 3 is corrugated to prevent the paper from coming into close contact with the suction negative pressure of the pump. That is, when the fluid having a high viscosity or the material is clogged, the suction negative pressure of the pump causes the paper to come into close contact with the flow path, resulting in an increase in pressure loss. Also, in such a case, where the material strength is weak,
In some cases, pressure may be concentrated to cause damage such as breakage of the material, resulting in a bad effect on the over-action.

〔Experimental result〕

Next, an experimental result of the filter element according to the present embodiment will be described in comparison with a conventional filter element.
The filter element is made of 70% chemical fiber, 5% pulp, 5% inorganic fiber, 0.80 mm thick paper and phenol resin as a binder.

The oil filter used in the experiment has an outer diameter of 65 mm and a height of 65 mm.
Is. The outer diameter of the filter element inside this oil filter is φ62, and the outer diameter of the reinforcing inner cylinder of the element is φ.
28, element height is 44 mm.

Under the design conditions as described above, a comparative experiment was performed between the conventional filter element formed in a chrysanthemum cross section and the filter element according to the present invention.

The experimental conditions of this comparative experiment were performed under the conditions shown in JIS D3904. The oil used at this time was an additive-free oil equivalent to SAE # 30, the oil temperature was 80 ° C, and the test flow rate was 10 / min.

According to the experimental results under the above conditions, although the pressure loss is conventional filter element is a 0.45 kg / cm ^2, the filter element of the present embodiment is 0.30 kg / cm ^2, the pressure loss is drastically reduced did. The life of the filter element is 45 hours in the conventional one, whereas it is 60 hours in the present embodiment, and the life can be extended. The over-efficiency of the conventional filter element is 78%, whereas the over-efficiency of this embodiment is 83%, which is about 5%.
Over-effect improved.

〔The invention's effect〕

As is apparent from the description of the embodiments above, the present invention is a filter element formed by winding a paper sheet having a large number of pleats formed into a tubular shape, and a surface located on the inner side of both ends of each pleated element. Since the funnel-shaped portions are formed between the adjacent folds by joining the folds to each other and making the surfaces located on the outer side of the adjacent folds closer to each other in the axial direction from the joining surface, the fluid to be superposed is one end surface of the element. The fluid gradually narrows down by the funnel-shaped portion and flows inward in the axial direction of the element at the time of this inflow, that is, pressure loss and head loss at the time of element inflow without contraction in the funnel-shaped portion. It can be kept to a minimum.

[Brief description of drawings]

FIG. 1 is a sectional view of an oil filter equipped with a filter element according to the present invention, FIG. 2 is a perspective view of the filter element according to the present invention, FIG. 3 is a plan view of the filter element, and FIG. Fig. 5 is a sectional view taken along line IV-IV in the figure, Fig. 5 is an enlarged transverse sectional view of an essential part of the filter element, Fig. 6 is a sectional view of an oil filter equipped with a conventional filter element, and Fig. 7 is FIG. 8 is a perspective view of a conventional filter element, and FIG. 8 is a plan view of the filter element. 1 ... Oil filter, 2 ... Oil filter case,
3 ... filter element, 4 ... fold, 4a ... fold surface, 5 ... sealing surface, 6 ... funnel-shaped portion, 8 ... bottom cover, 9 ... reinforced inner cylinder.

Claims (1)

[Claims] 1. A filter element formed by winding a paper having a large number of folds into a tubular shape, wherein the surfaces of the respective folds located on the inner sides of both ends of the element are joined to each other and the outer sides of adjacent folds are joined together. A filter element characterized in that a funnel-shaped portion is formed between adjacent folds such that the surfaces located at the positions are close to each other in the axial direction from the joint surface.