JPS61161113A - Filter for fluid - Google Patents

Abstract

PURPOSE:To eliminate breakage at corners which generates in the stage of rolling up a filter medium having corrugated sectional shape by providing notched line on at least sloped surface of the inside peripheral side of the filter medium from its external peripheral side toward the internal peripheral side. CONSTITUTION:Bending lines 12 are applied along a sector of a sectorial filter medium 10 by hot-pressing a line cutting knife held at high temp. to a filter medium 10, etc. then the filter medium 10 is bent by a bending device to give the filter medium corrugated sectional shape. Further, crest parts (a)-(e) are formed on the filter medium 10, and plural numbers of notched lines 14 directing from the top of the crest toward the valley are formed at regular intervals on the inside sloped surface of the crest parts (a)-(e). As the result, the rolling of the filter medium 10 can be executed exactly along the notched lines 14, so the rolling is done to obtain polygonal shape exactly similar to the desired shape.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fluid filter, and is effective for use in, for example, air filters, oil filters, etc. for automobiles.

(Prior Art) Conventionally, as shown in, for example, Japanese Unexamined Patent Publication No. 57-140617, a fluid filtration system has been constructed by continuously bending a fan-shaped or trapezoidal band-shaped filter medium into a cross-sectional shape, and then curving the band-shaped filter medium into a circular shape. In the body, bending lines are attached to the bending position before the body is bent into a wave-like cross-sectional shape. For example, as shown in FIG. 2, the bending lines can be applied by heating the blade 101 to a high temperature and applying the bending line by heat pressing; or simply by attaching the blade 101 to the filter medium 104. There is a method of applying bending lines by pressing.

When a filter medium with bending lines is continuously bent into a wavy cross section and rolled into a circular shape, irregular corner bends occur as shown in Figure 3, resulting in a shaped shape as shown in Figure 4. 10
5, there is a problem in that defects such as tearing of the filter medium and buckling occur as shown in FIG. In addition, Fig. 6 (a
Even if the top surface is well rounded into a circle as shown in Figure 6 (
As shown in C), there is still a problem of corner bending on the lower surface.

(Problems to be Solved by the Invention) The present invention solves the problem of the corner bending phenomenon that occurs when a filter medium that is continuously bent in a wavy manner is rolled up.

(Means for solving the problems) In the present invention, the following measures were taken to solve the above problems. That is, it has a band-shaped filter medium whose length dimension at one end is longer than the length dimension at the other end, and this band-shaped filter medium is bent between the two ends into a wave-shaped cross section, and the one end side is the outer circumferential side and the other end side is the outer circumferential side. A fluid filtration body curved from the end side to the inner circumference side, in which a cut line is provided from the outer circumference side toward the inner circumference side at least on the inner circumference side slope of the filter medium bent in the cross-sectional wave shape. As a body.

(Example) Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a perspective view showing a state immediately after the filter medium 10 is bent into a wave shape. 7 shows a state before the filter medium 10 is bent into a wave shape, and FIG. 8 is an enlarged view of section A in FIG. 7. As can be seen from these figures, the filter medium 10 before being bent has a fan shape, and a plurality of bending lines 12 (11 in this embodiment) are provided along this fan shape. This bending line 12 is made by heating the blade to the filter medium 1.
0 by thermocompression bonding. The filter medium 10 provided with the bending lines 12 in this manner is bent into a wave-like cross-sectional shape by a bending device (not shown), as shown in FIG. In this embodiment, five peaks are formed, and the five peaks are designated by symbols a to e from the inside (FIG. 1). A plurality of incision lines 14 are cut at equal intervals on the inner slopes of the mountain parts a to e, from the top of the mountain part toward the valley. 14 trees in Sui, 16 trees in Yamabe C,
17 pieces are formed in the ridge part d, and 18 pieces are formed in the ridge part e. As can be seen from FIGS. 7 and 8, this cut line 14 has an inclination angle θ (θ=30° in this embodiment) with respect to the normal line 1-12 of the bend line 12. The slope is reversed for each mountain. In addition, if the inclination angle θ is θ=06, the portion N that cannot be bent as shown in the model diagram of FIG.
However, the conventional irregular corner bending phenomenon does not occur. Further, in this embodiment, the thickness of the cut line 14 is 1 mm, the thickness of the filter medium 10 is 3.2 mm, and the cut depth is 0.2 to Q, 5 mm.

Next, the principle of how the filter medium 10 can be reliably bent into a regular polygon without causing corner bending by providing the cut lines 14 will be explained using a simple model diagram.

In order to reliably bend all of the cut lines 14, it is necessary to have ease of bending at the initial stage of bending and difficulty in bending after bending to prevent only one cut line from bending too much. That is, as shown in the model diagram of FIG. 1O, when a bending moment M + acts on the filter medium 10 and bends at the notch line 14, a bending stop moment Mz is generated to stop the bending progress.
Therefore, as shown in FIG. 11, if a cut line 14 having an inclination angle θ is provided, when a moment M that tends to round the filter medium 10 acts on the cut line 14, this moment M will be applied to the cut line 14. It is decomposed into a moment M when the filter medium 10 tries to bend along the same direction, and a moment M2 when the bending stops.In other words, the above-mentioned ease of bending and the difficulty of bending after bending exist at the same time. When folded, it will look like Figure 12, and the cut line 1
It is regularly bent into a regular polygon along 4.

Although one embodiment of the present invention has been described above, the notch line 14
Various other modifications of the shape are possible. For example, as shown in FIG. 13, the incision lines 14 may be stopped in the middle of the slope instead of extending over the entire slope of the mountain. Also,
The cut streaks 14 may have a mountain wave shape as shown in FIG. 14, or may have a continuous semi-ellipse shape as shown in FIG. 15. Further, in the above-described embodiment, the directions of the notches 14 were reversed for each ridge, but they may all be oriented in the same direction. Furthermore, the bending line 12. The scoring method for the cut streaks 14 is a heating press method, a dielectric method,
Possible methods include a cold press method, an ultrasonic tracing method, a roller reinforcement method, and a movable spatula method.

As an example, FIG. 16 shows a cross section of a streak S formed by the hot pressing method, and FIG. 17 shows a cross section of a streak S formed by the cold pressing method. The filter medium 10 is composed of three layers: a dense layer 10a, an intermediate layer 1-Ob, and a coarse layer 10c.

Although the rounded shape of the filter medium 10 is a regular polygon M that approximates a perfect circle R as shown in FIG. 18, it is also possible to form a polygon that approximates an ellipse.

(Function) In the present invention, when the filter medium is rolled up, the cut lines act as a kite, and the filter medium is accurately rolled along the cut lines.

(Effects of the Invention) Therefore, it is possible to round the polygon into an accurate polygon that approximates the desired shape without causing the irregular corner bending phenomenon that occurs in the conventional case.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a filter medium according to an embodiment of the present invention, FIG. 2 is a perspective view showing a conventional example, FIG. 3 is a plan view of the conventional example, and FIG. 4 is a perspective view showing the conventional example during shaping. Fig. 5 is a partial sectional view showing a conventional example, Fig. 6 shows a conventional example, where (a) is a plan view, (b) is a front view, (C) is a bottom view, and Fig. 7 is a diagram of the embodiment. 8 is a detailed view of part A in FIG. 7, FIG. 9 is a model diagram of the filter medium, and FIGS. 10, 11, and 12 are model diagrams for explaining rounding of the filter medium. FIGS. 13, 14, and 15 are diagrams showing modified examples of the cut streaks, FIGS. 16 and 17 are cross-sectional views of the streaks, and FIG. 18 is a model diagram showing a rounded shape. 10... Filter medium, 12... Bending line, 14... Cutting line.

Claims (1)

[Claims] having a band-shaped filter medium whose length dimension at one end is longer than the length dimension at the other end, and bending the band-shaped filter medium between the two ends into a wave-like cross-sectional shape;
Further, in the fluid filter body which is curved so that the one end side is the outer circumferential side and the other end side is the inner circumferential side, the filter medium bent in the cross-sectional wave shape has at least an inner circumferential slope from the outer circumferential side to the inner circumferential side. Fluid filtration body with cut lines directed towards.