JPS62279814A - Liquid purifying filter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Industrial Application Field] The present invention comprises a two-part plastic case housing a wound filter element therein; At the periphery, they are connected to each other without leaking through irregularly shaped cross-sections that match the inside and outside, and the area surrounding the wound filter element in an annular manner separates the dirty side and clean side inside the case from each other. Relating to a filter for the purification of liquids, the scope of which has upright fins surrounding it in a case.

[Conventional technology]

Such a filter is known from German Patent Application DE 34 25 347 A1, in which a wound filter element is arranged in a plastic case consisting of a double-sided case pot and an associated case lid. Both case parts have contoured cross-sections at their internally and externally engaging peripheral edges, creating an annular gap of Z-shaped cross-section, which is guided radially to the outer circumference of the W element and dispenses the adhesive. A single adhesive point is thus created which surrounds the filter element in an annular manner, connecting the housing parts to each other and separating the dirty and clean sides of the housing from each other. However, in the mass production of fuel filters, it is a disadvantage that a free-flowing two-component adhesive, which hardens at room temperature after the assembly of the two parts, is required for this bonding point. This structure of the filter complicates the handling of its components. Additionally, inaccurate metering of the two-component adhesive in the case pocket can cause too much adhesive to be forced inward from the combination of both case parts, thereby narrowing the rectangular passageway and impeding its flow. It could get worse. Such known wound elements often have a longitudinal seam on their outer periphery consisting of hot melt adhesive.

At the intersection of this longitudinal seam and the annularly surrounding adhesive point, two different types of adhesive meet, which can lead to sealing problems under adverse conditions of use. It should be noted that such wound elements are generally not strictly circular and are also relatively soft, requiring particularly careful handling during assembly.

Furthermore, a disposable filter suitable for mass production is known from German Patent Application No. 2 244 594, whose two-part plastic case houses a disc-shaped filter element. The funnel-shaped case part has aX inside.
It has a fin, and this fin is fixedly and seamlessly welded to the periphery of the disc-shaped filter element by an ultrasonic WE weld.

A disadvantage of this filter is that this structure is not suitable for the insertion of wound filter elements.

[Problem that the invention seeks to solve]

The objective of the present invention is to provide a liquid purification filter suitable for mass production using a wound filter element.

[Means for solving problems]

In order to solve this thickness adjustment, according to the present invention, a stable annular flange made of fusible plastic is formed integrally with the wound filter element, and is formed by both parts in the area of the edge of the irregular cross-section, and is formed in the area of the edge of the case. The sealing point between the dirty side and the clean side is formed by an ultrasonic weld between the fin and the flange, which enters an annular groove-shaped cavity that opens towards the inside.

〔Effect of the invention〕

The filter according to the invention has the advantage that a disposable filter with wound filter elements is obtained which is simple in construction and inexpensive. This arrangement provides a leak-tight seal between the dirty and clean sides, even with a relatively flexible wound filter element, while maintaining its properties, meeting chemical and physical requirements during use. Furthermore, the stability of the wound filter element against deformation is increased, which facilitates its handling during assembly. The encounter of two different types of adhesives is also avoided, thereby reducing the need for sealing. Furthermore, the structure is suitable for automated mass production. Swelling of the adhesive by the fuel to be purified and the resulting internal stresses in the sealing points, as well as peeling of the adhesive bond and leakage points resulting therefrom, are largely prevented.

Advantageous developments and improvements of the filter according to claim 1 are possible with the measures listed in the dependent claims. In the embodiment according to claims 2 and 3, the winding welded into the housing part can be welded into the housing part by using separate welding points for the housing part and for the filter element wound on the housing part. It becomes possible to perform a sealing inspection of the filter element. Furthermore, claim 4
With the above configuration, both types of sonic welding can be performed in a single process. Further advantageous developments emerge from the remaining dependent claims, the drawing and the description thereof.

〔Example〕

Two embodiments of the invention are shown in the drawings and will be described below.

FIG. 1 shows a fuel filter 10, whose case 11 includes a cup-shaped case bowl 12 and an attached case lid! Consists of 3. Both parts of the case 11 are made of plastic. An inflow connecting tube piece 14 is coaxially provided on the case lid 13 which is formed in a funnel shape. Bottom 1 of pot-shaped case bowl 12
5 has a radial fin on the inside! 6 is provided, and an outflow connection tube piece 17 is provided coaxially with respect to the inflow connection tube piece I4. Inside the housing 11, between the two inflow and outflow connection pieces 14 and 17, a wound filter element 18 is provided, through which the fuel is passed axially. In this wound filter element 18, a filter paper strip with a V-shaped cross section is wound spirally around a central tube 19 with the addition of a sealing strip, forming two spiral spaces that open toward opposite end faces. is formed. The wound filter element 18 rests on the fin 16 on the one hand and on the case lid 13 via a cap 21 that closes the central tube 19 on the other hand.

The case bowl 12 has a first cylindrical section 2 starting from its bottom 15.
2, this cylindrical section transitions via a radially extending step 23 into a second widened cylindrical section 24. On the inside of this second cylindrical section 24 an inclined shoulder 25 is provided, on which a corresponding opposite shoulder 26 of the case lid 13 is provided.
is listed. For this purpose, the case lid 13 inserted into the case pot 12 has a contoured outer circumferential edge, and the second cylindrical section 24 has a corresponding inner circumferential edge of a contoured cross-section.

Both case parts 12 and 13 have their shoulders 25, 26
Since they are fixedly connected to each other by the sonic welding portion 27, the inside of the case 11 is tightly sealed from the outside, as shown in detail in FIG. 2.

The case II
An annular groove-shaped cavity 29 is formed that opens toward the inside of the housing. An upright fin 31 which is preferably arranged starting from the step 23 and surrounding the first cylindrical section 22 in an annular manner and on the diameter of the first cylindrical section 22.
has entered this void 29. It is advantageous if the diameter of the tip of this fin is equal to or larger than the outer diameter of the first cylindrical section 22.

As shown in detail in FIG. 2, an annular flange 32 provided on the wound filter element 18 extends into the cavity 29. This flange 32 is made of polyamide, is integrally injection molded around the outer periphery of the wound filter element, and is further formed in an annular shape to form a flat stop surface 33 extending preferably at right angles to the longitudinal axis of the filter. There is.

The integrally injection molded flange 32 forms a reliable leak-tight connection with the wound filter element 18.

In particular, the thickness and width of this flange 32 are chosen such that it is generally dimensionally stable and therefore provides great dimensional stability even to flexible wound filter elements. For this purpose, the width of the flange 32 in a plane extending at right angles to the # axis of the filter is equal to the width of the first cylindrical section 22
The thickness is selected to be about three times the wall thickness of the case pot 12 in the range of , and its thickness is about twice. The annular flange 32 rests on the annular fin 31 with its stopper surface 33 and is fixedly and seamlessly connected thereto by a second ultrasonic weld 34 . With respect to the end face 28 and with respect to the second cylindrical section 24, the flange 32 is designed with a slight play. Since the annular flange 32 has no cavity inside and forms a flat stopper surface 33 on the outside, the wound filter element 18 and the cup-shaped case bowl 12 are easily separated during ultrasonic welding.
A perfect leak-tight connection is created between the two. An integral injection molded surface 3 having a thickness of approximately 2@ with respect to the thickness of the flange 32
5 ensures a stable and leak-free coupling of the picture components, so that the flow cross-section of the wound filter element 18 is hardly adversely affected.

When assembling the fuel filter 10, use the cup-shaped case bowl]2
The hemlocked filter element 18, together with the flange 32 formed integrally therewith, is inserted until its stop surface 33 abuts the tip of the fin 31. Next, the ultrasonic 'Fj contact part 34
This provides a seal between the wound filter element 18 and the case bowl 12. If necessary, the sealing properties of the ultrasonic weld 34 can be tested by a subsequent bubble test. Then the case lid I3 is inserted into the second cylindrical section 24,
In the second step both shoulders 25, 26 are attached to the ultrasonic weld 27
They are fixedly connected to each other without shaking.

Fuel filter 10 is used in a known manner.

The gasoline or diesel fuel to be purified flows via the inlet connection piece 14 to the dirty side of the filter, is purified axially through the wound filter element 18 and reaches the outlet connection piece 17 from the clean side.

At this time, the ultrasonic welding section 27 seals the dirty side from the outside, and the second ultrasonic welding section 34 separates the dirty side inside the filter 10 from the clean side.

FIG. 3 shows a second practical example of a fuel filter 40 which differs from the fuel filter according to FIG. 1 in the following respects.

In the second filter 40, the radial step 23 does not have a fin that penetrates into the cavity 29, so that the step 23 has a flat support surface 4
1, and a lower stopper surface 3 of the flange 32 is formed thereon.
3 is crowned. The end face 28 of the case lid 42 of the filter 40 is now provided with a fin 43 that extends into the cavity 29 . The fin 43 is supported on the upper part 44 of the flange 32;
There is formed a sonic weld portion 45 that separates the dirty side of the case 11 from the clean side.

The second filter 4θ has the advantage of being simple to assemble. The wound filter element 18 is inserted into the pot 12 and is self-centered.

The flat stop surface 33 of the flange 32 is in close contact with the flat annular support surface 41 . The case lid 42 is then introduced into the case pot and both ultrasonic welds 45 and 27 are made simultaneously in a single step. In this case, the forces exerted by the fins 43 on the flange 32 are transmitted from the flange 32 to the step 23, so that no harmful forces are introduced into the wound filter element 18.

It is of course possible to modify the illustrated filter without departing from the spirit of the invention.

The design according to the invention can also be applied to filters in which, instead of the illustrated conduit filter design, both the inflow and outflow connection pieces are provided in the same housing part. It is also possible to form an inclined chamfer in the stop surface 33 of FIGS. 1 to 3, which extends at right angles to the longitudinal axis of the filter.

It is particularly important here that the flange 32 be designed as a geometrically stable element that allows a flat stop surface suitable for satisfactory ultrasonic welding. Instead of pure polyamide for the integrally injection molded flanges, other suitable soluble plastics can be chosen.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a first actual example of the filter, FIG. 2 is an enlarged sectional view of a portion thereof, and FIG. 3 is a longitudinal sectional view of a portion of a second actual example of the filter. 10, 40...Fuel filter, 11...Case, 1
2, 13...Case part, 18...Wound filter element, 29...Vacancy, 31.43...Fin, 32...
・Flange, 34.45...Yomane y! welded part.

Claims (1)

[Scope of Claims] 1. A plastic case consisting of two parts houses a wound filter element therein, and both parts of the case are seamlessly connected to each other at the periphery of the case through a contoured cross-section that matches the inside and the outside, A sealing point surrounding the wound filter element in an annular manner separates the dirty side and the clean side of the interior of the case from each other, and in the area of the sealing point there is an upright fin that surrounds the inside of the case. An annular flange (32) is integrally formed on the wound filter element (18) and extends in both parts (12, 1) in the area of the profiled edge.
The sealing point between the dirty side and the clean side is formed by the fins (31, 43) and the flange (32). ) A filter for purifying liquid, characterized in that it is formed by ultrasonic welding parts (34, 45) with 2. The two case parts (12, 13) are connected to each other in a leak-tight and fixed manner by means of an ultrasonic weld (27) at the shoulders (25, 26) where they abut against each other. The filter described in range 1. 3. The filter according to claim 1, characterized in that the fin (31) is provided on an overhanging step (23) of a cup-shaped case pot (12) as one case part. 4. According to claim 1, the fin (43) is provided on the end surface (28) of the case lid (42) as the other case part that partitions the cavity (29). filter. 5. The width of the flange (32) extending in the radial direction with respect to the longitudinal axis of the filter (10, 40) is greater than the wall thickness of the cup-shaped case bowl (22) as a case part, especially the wall thickness of 1.5 to 3. 2. A filter according to claim 1, characterized in that the filter is twice as large. 6. characterized in that the flange (32) has a substantially rectangular cross section and has a flat stop surface (33),
A filter according to claim 5. 7. characterized in that the fins (31, 43) are on a diameter equal to or larger than the outer diameter in the area of the first cylindrical section (22) of the cup-shaped case pot (12) as case part, A filter according to claim 1, 3, or 4. 8. Filter according to claim 1 or 5 or 6, characterized in that the flange (32) consists of polyamide. 9. Filter according to claim 4, characterized in that the ultrasonic weld (27, 45) is formed on the case lid (42) and is made in one step.