JP2000312807A - Filter element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter element which is a type of being internally and externally pressurized and simplified in the whole structure while the surface area of a filter paper sheet being remarkably widened and the manufacturing cost being suppressed. SOLUTION: This filter element 2 comprises a large hollow cylindrical body 18 made by folding a filter paper sheet 22 in approximately a chrysanthemum-like shape, an inflow route 12 formed in the axial part of the large hollow cylindrical body 18, and four small hollow cylindrical bodies 20 each of which is installed in the large hollow cylindrical body 18, formed by folding a filter paper sheet 24 in approximately a chrysanthemum, so positioned as to keep the axial part approximately at equal distance from the axial part of the large hollow cylindrical body 18 in the radius direction and provided with an outflow route 14 in the axial part. Water is supplied through the inflow route 12 to fill the inside of the large hollow cylindrical body 18 and a part of the water is passed through and filtered by the large hollow cylindrical body 18 to flow out the filter element and a part of the rest is passed through and filtered by the respective small hollow cylindrical bodies 20 and discharged through the respective outflow routes 14. The durability of the filter element can be improved attributed to that the surface area of the filter element and the filtration surface area are thus enlarged and that filtration is carried out by externally pressurizing type filtration, which causes a slight pressure load.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter element used for filtering a gas or a liquid (hereinafter referred to as "fluid"), and more particularly to a filter element using a so-called chrysanthemum flower element.

[0002]

2. Description of the Related Art In a wire electric discharge machine and an NC electric discharge machine, a filtration device for purifying a fluid (particularly, a liquid) used in machining iron or wire is used.

[0003] In these filtration devices, filter elements are housed, and these filter elements perform a substantial filtration function.

[0004] In these filter elements, it is required to filter as much fluid as possible in the same time, and for that purpose, it is a proposition to increase the filtration area of the filter element. That is, it is required that the surface area of the filter element be as large as possible.

The chrysanthemum-shaped filter element is classified into a so-called internal pressure type and an external pressure type.

[0006] In the case of the internal pressure type, since the fluid to be filtered passes from the inside to the outside, pressure is applied from the inside to the outside. The chrysanthemum-shaped element is longer at the outer circumference than at the inner circumference.Therefore, when viewed from the inside, the entrance between the peaks of the folded filter paper is narrow and the depth is wide. When the fluid passes, a pressure load is likely to be applied to the entire filter element. However, since this type accumulates dirt inside the element, it is convenient when replacing the element because the element can be taken out while retaining the dirt inside.

In the case of the external pressure type, since the fluid to be filtered passes from the outside to the inside, pressure is applied from the outside to the inside. Since the outer periphery of the chrysanthemum-shaped element is longer than the inner periphery, when viewed inward from the outside, the entrance between the peaks of the folded filter paper is wide and the depth is narrow. In addition, when the fluid to be filtered passes through, the pressure on the entire filter element is less likely to be imposed. However, since this type accumulates dirt outside the element, when the element is replaced, the dirt on the outside tends to spill when the element is taken out.

In recent years, there has been developed a filter element in which the pressure balance between the internal and external pressures is adjusted as a whole in consideration of the advantages and disadvantages of the internal pressure type and the external pressure type. In the internal / external pressure type, the above-mentioned filtration area can be increased, and the entire filter element is evenly pressurized, so that the durability of the entire filter element is improved.

Conventionally, among the internal and external pressure types, there is a coupler type as shown in FIG. This coupler type is
In the cylindrical filter element 102, a chrysanthemum flower-shaped outer filter paper 106 and a chrysanthemum flower-shaped inner filter paper 108 provided in the center of the filter element are provided. The fluid that is filtered through 106 and flows out of the element (i.e., due to the internal pressure) and the fluid that is filtered through the inner filter paper 108 and flows out through an outlet passage 110 provided in the shaft of the inner filter paper 108 ( That is, it is divided into those based on external pressure). In some cases, a shaft is provided instead of the coupler. According to the internal / external pressure coupler type, the filtration area can be relatively large, but the filtration area has not been dramatically increased and the filtration efficiency has not been improved.

On the other hand, among the internal and external pressure types, the center shaft type as shown in FIG. 2 has a cylindrical filter element 112, a chrysanthemum-shaped outer filter paper 114, and a chrysanthemum-shaped filter paper provided at the center of the filter element. Inner filter paper 116
The fluid to be filtered flows in from the center shaft 118, and the fluid that has passed through the upper part 120 inside the element is filtered through the outer filter paper 114 and flows out of the element (that is, due to the internal pressure). ) And inner filter paper 1
The fluid is filtered through the outlet 16 and flows out through the outlet passage 122 provided around the center shaft (that is, by the external pressure). In some cases, a coupler is attached instead of the center shaft 118. Although the inner and outer pressure center shaft type can provide a relatively large filtration area, the filtration area has not been increased yet, and the filtration efficiency has not been significantly improved. In addition, the structure of the upper part inside the element becomes complicated, and costs increase.

[0011]

SUMMARY OF THE INVENTION The present invention is a durable internal / external pressure type which does not apply an excessive load to a filter element. The structure of the entire filter element is simplified while the surface area of the filter element is greatly increased. It is an object of the present invention to obtain a filter element which can be reduced in manufacturing cost.

[0012]

According to a first aspect of the present invention, there is provided a filter element for filtering a fluid, wherein a cross section of a filter paper which is continuously folded in a W shape and formed into a pleated shape has a substantially chrysanthemum flower shape. A large hollow cylindrical body, an inflow passage provided inside the large hollow cylindrical body for supplying a fluid to be filtered, and provided inside the large hollow cylindrical body, and continuous with a W shape. A plurality of small hollow cylindrical bodies, wherein the folded and folded pleated filter paper is formed to have a substantially chrysanthemum flower-shaped cross section and an outflow passage is formed in the substantially chrysanthemum flower-shaped shaft portion. And a filter element characterized by the following.

According to the first aspect of the present invention, the fluid to be filtered is supplied from the inflow passage, and the supplied fluid to be filtered fills the large hollow cylindrical body, and a part of the large hollow cylindrical body is filled. The water passes through the small hollow cylindrical body and is filtered by passing through each small hollow cylindrical body, and is discharged through the respective outflow passages of the shaft.

When the fluid to be filtered is going to pass through the large hollow cylindrical body, the fluid to be filtered exerts pressure on the chrysanthemum-shaped large hollow cylindrical body from the radially inner side to the outer side.
The large hollow cylindrical body has a longer length at the outer periphery of the chrysanthemum flower than at the inner periphery. Since the number of bends of the filter paper of the large hollow cylindrical body is the same at the outer circumference and the inner circumference, the gap between the ridges is large on the outer circumference and smaller on the inner circumference. The fluid to be filtered first tries to pass through the filter paper by passing between the ridges of the inner fold, so it will enter from a narrow entrance and pass through the folds, forming a large hollow cylindrical body. Will be subjected to considerable pressure from inside to outside.

The fluid to be filtered filled in the large hollow cylinder tends to pass through the filter paper of each small hollow cylinder. At this time, the fluid to be filtered exerts pressure on the chrysanthemum-shaped small hollow cylindrical body from the outside in the radial direction to the inside. The outer periphery of the chrysanthemum flower has a longer length than the inner periphery of the small hollow cylindrical body. Since the number of folds of the filter paper of the small hollow cylindrical body is the same at the outer circumference and the inner circumference, the gap between the ridges is large on the outer circumference and small on the inner circumference. The fluid to be filtered first tries to pass through the filter paper by passing between the peaks of the outer fold, so that it enters from the wide entrance and passes through the folds, from the outside of the small hollow cylindrical body to the inside. The pressure applied to the filter is moderate and not excessively large, and the fluid to be filtered passes smoothly through the filter paper, so that the effective filtration area can be increased.

According to the first aspect of the present invention, a large hollow cylindrical body is applied with a considerable internal pressure (pressure from inside to outside), but a small hollow cylindrical body is subjected to a not so strong external pressure (pressure from outside to inside). Since there are a plurality of bodies, the pressure of the entire filter element is balanced, and the passage of the fluid through the entire filter element is smooth, that is, the filtration efficiency is improved and the durability is improved. Furthermore, since a plurality of small hollow cylindrical bodies are provided, not only can the surface area of the filter element be significantly increased, but also a considerable amount of the fluid to be filtered is filtered through the small hollow cylindrical bodies, so that the pressure burden is reduced. It is possible to increase the filtration area by the external pressure filtration with a small amount, and further contribute to the durability of the filter element.

According to a second aspect of the present invention, there is provided the filter element according to the first aspect, wherein the inflow passage is provided in a shaft portion of the large hollow cylindrical body.

According to the second aspect of the present invention, since the inflow passage is provided in the shaft portion of the large hollow cylindrical body, the fluid to be filtered is supplied from the center of the large hollow cylindrical body. The fluid to be filtered is uniformly filled in each direction in the large hollow cylindrical body, and is efficiently filtered through the large hollow cylindrical body and each small hollow cylindrical body.

According to a third aspect of the present invention, each of the plurality of small hollow cylindrical bodies is disposed at a position substantially equidistant in a radial direction from a shaft part of the large hollow cylindrical body. 2. The filter element according to claim 1, comprising four small hollow cylindrical bodies.

According to the third aspect of the present invention, the four small hollow cylindrical members are arranged such that each shaft portion is located at substantially the same radial distance from the shaft portion of the large hollow cylindrical member. Are arranged, the chrysanthemum-shaped small hollow cylindrical bodies are arranged at a predetermined distance from each other at the same distance from the shaft portion of the large hollow cylindrical body. When the fluid to be filtered flows from the inflow passage in the large hollow cylindrical body, the supplied fluid to be filtered fills the large hollow cylindrical body. The four small hollow cylinders are arranged at a predetermined interval from each other, and the intervals between the four small hollow cylinders and the large hollow cylinder are also equal, so that The supplied fluid to be filtered reaches each cylindrical body without being largely retained in the large hollow cylindrical body, and is smoothly filtered. By arranging four chrysanthemum-shaped small hollow cylindrical bodies, the effective filtration area can be increased and the filtration efficiency can be improved. The reason why four small hollow cylinders are provided is that three small hollow cylinders are not enough to increase the filtration area.
If the number of the filter elements is five, the pitch (ie, the length in the radial direction) of each filter paper becomes small, and the filter paper area cannot be fully filled as a whole filter element. Also, the filter paper used is a chrysanthemum flower shape for both the large hollow cylindrical body and the four small hollow cylindrical bodies, so that a conventional W-shaped one can be used, which is convenient and inexpensive.

[0021]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 3 is a perspective view showing a filter element 2 to which the present invention is applied. The filter element 2 has a cylindrical shape as a whole, and has an upper plate 4 on the top surface, a bottom plate 6 on the bottom surface, and an outer cylinder 10 on the side surface. FIG.
FIG. 4 is a sectional view taken along line AA of the filter element of FIG. 3. The upper plate 4 has an overall shape in which an inflow passage 28 having a round hole is formed in the center, and four outflow passages 30 having a round hole smaller than the inflow passage 28 are formed at a predetermined distance in each of four directions in the radial direction from the inflow passage 28. Is a disk-shaped member. The bottom plate 6 is a disc-shaped member as a whole having a round hole inlet port 28 formed in the center. Both the top plate 4 and the bottom plate 6 are provided around the filter element 2 so as to be fixed when attached to the outer cylinder 10.
The brim in the height direction is slight. The outer cylinder 10 is formed by punching a thin metal plate with round punching over the entire surface (in FIGS. 3 and 5, punching is shown only at the center of the side).
The outer cylinder 10 is usually made of a galvanized iron plate. In the outer peripheral portion of the outer cylinder 10, a metal band 8 closely surrounds the outer cylinder 10 in the middle of the height direction of the filter element 2. A welded portion 32 exists on the band 8 at a predetermined distance in the longitudinal direction of the band 8. The welding portion 32 is formed by welding the band 8 and the outer cylinder 10 at each point at a predetermined distance.

A cylindrical inner cylinder 26 for forming the inflow passage 12 is provided so as to surround the central axis of the filter element 2. The inner cylinder 26 is a thin metal plate obtained by performing round punching on the entire surface of the plate to form a cylinder. The inner cylinder 26 is also made of a rust-proof zinc-iron plate. The lower end of the inner cylinder 26 is fixed to the bottom plate 6.

FIG. 4 is a view showing the filter element 2 of FIG.
It is a B sectional view. Along the inner circumference of the outer cylinder 10, a filter paper 22, which is continuously folded in a W shape and formed into a pleated shape, is formed and arranged in a substantially chrysanthemum flower shape as shown in FIG. It is body 18. The outer peripheral portion of the large hollow cylindrical body 18 is almost in contact with the inner periphery of the outer cylinder 10. The large hollow cylindrical body 18 is formed by bending a single piece of rectangular filter paper into a W-shape as described above to form a pleated shape. It has been stopped. The width of the fold of the filter paper 22 in the direction of the inner cylinder 26 (the length in the radial direction of a substantially chrysanthemum flower) is referred to as a pitch.

Inside the large hollow cylindrical body 18, there is provided a small hollow cylindrical body 20 in which a filter paper 24, which is continuously folded into a W shape and formed into a pleated shape, is formed so as to have a substantially chrysanthemum-shaped cross section. It is arranged individually. An outflow passage 1 is provided on the inner periphery of each small hollow cylindrical body 20.
A cylindrical middle cylinder 16 forming the cylinder 4 is erected. Middle cylinder 1
Reference numeral 6 denotes a thin metal plate obtained by performing round punching on the entire surface of the plate to form a cylinder. The middle cylinder 16 is also made of a rust-proof zinc-iron plate. The lower end of the middle cylinder 16 is fixed to the bottom plate 6. The outer peripheral portion of the middle cylinder 16 is almost in contact with the inner periphery of the small hollow cylindrical body 20. The pitch of the filter paper of the small hollow cylindrical body 20 is ／ −3 of the pitch of the filter paper of the large hollow cylindrical body 18 because the size of the cylindrical body itself is smaller than that of the large hollow cylindrical body 18.
It is about 1/2 size. The inner diameter of the outflow passage 30 is smaller than the inner diameter of the outflow passage 14.

The four small hollow cylinders 20 are arranged such that the middle cylinders 16 are located at substantially equal distances in the radial direction from the shaft portion of the large hollow cylinder 18. Each middle cylinder 16
Are substantially equal in the circumferential direction, and a square is formed by connecting the central axes of the respective middle cylinders 16 with a line on a horizontal plane.

With the above configuration, fluid can move between the inner periphery of the chrysanthemum-shaped filter paper 22 of the large hollow cylindrical body 18 and the outer periphery of the chrysanthemum-shaped filter paper 24 of each small hollow cylindrical body 20. Some voids are formed. This gap is made up of four small hollow cylindrical bodies 20.
From any of the above, the size is substantially equal to the inner circumference of the large hollow cylindrical body 18. In addition, a certain gap is formed between the small hollow cylindrical bodies 20 so that the fluid can move. Also in this gap, the size of each of the four small hollow cylindrical bodies 20 is substantially equal. Further, a certain gap is formed between each small hollow cylindrical body 20 and the inner cylinder 26 so that the fluid can move. The space between each small hollow cylindrical body 20 and the inner cylinder 26 is also substantially the same. The above gaps are of course connected to each other.

The reason why the four small hollow cylindrical bodies 20 are arranged is that each gap has a size capable of smoothly moving a fluid as described above, and that three hollow hollow cylindrical bodies 20 are not enough to increase the filtration area. If the number of the filter elements is 5, the pitch (that is, the length in the radial direction) of each filter paper becomes considerably small, and the area of the filter paper cannot be fully filled as a whole filter element.

The operation of the embodiment of the present invention will be described. In the present embodiment, an example will be described in which a filter element 2 is used as a filtration device for washing water used when processing iron or wire in a wire electric discharge machine.

When the filter element 2 is used,
As shown in FIG. 3, it is used with the upper plate 4 and the bottom plate 6 mounted. Water to be filtered enters the inner cylinder 26 which is the inflow passage 12 from the inflow passage 28 which is a round hole at the center of the bottom plate 6. The water that has entered the inner cylinder 26 enters the inside of the large hollow cylindrical body 18 through the punching formed in the inner cylinder 26, and fills the above-mentioned gaps.

A part of the water filled in each of the voids is filtered through the filter paper 22 of the large hollow cylindrical body 18 and discharged out of the filter element 2. At this time, a water pressure is applied to the large hollow cylindrical body 18 radially outward of the large hollow cylindrical body 18, and the outer cylinder 10 supports the pressure of the filter paper 22 due to the water pressure. The large hollow cylindrical body 18 has a longer length at the outer periphery of the chrysanthemum flower than at the inner periphery. Since the number of folds of the filter paper of the large hollow cylindrical body 18 is the same at the outer circumference and the inner circumference, as shown in FIG. 6, the gap between the ridges of the fold is larger on the outer circumference and smaller on the inner circumference. Therefore, between the peaks of the filter paper 22 of the large hollow cylindrical body 18, when viewed outward from the inner cylinder 26, the entrance is narrow and gradually widens toward the back. Since water first tries to pass through the filter paper 22 between the folds of the inner circumference, it tries to pass through the narrow entrance and pass through the gradually widening of the filter paper. Therefore, a considerable pressure is applied to the large hollow cylindrical body 18 from the inside to the outside. However, when the filter paper (element) 22 of the large hollow cylindrical body 18 is replaced, since the dirt is accumulated inside the chrysanthemum flower shape, it is possible to take out the element 22 while holding the dirt attached to the inside. It is convenient because it can be done.

Another part of the water filled in each of the voids is filtered through the filter paper 24 of the small hollow cylindrical body 20,
The gas enters the middle cylinder 16 through the punching formed in the middle cylinder 16 and is discharged to the outflow passage 14. At this time, water pressure is applied to the small hollow cylindrical body 20 radially inward of the small hollow cylindrical body 20, and the middle cylinder 16 supports the pressure of the filter paper 24 due to this water pressure. The small hollow cylindrical body 20 also has a longer length at the outer periphery of the chrysanthemum than at the inner periphery. Small hollow cylindrical body 20
Since the number of bends of the filter paper is the same for the outer circumference and the inner circumference, FIG.
As shown in (1), the gap between the ridges of the fold is large on the outer periphery and becomes smaller toward the inner periphery. Therefore, the entrance between the peaks of the filter paper 24 of the small hollow cylindrical body 20 is wide when viewed from the outside toward the inside (in the direction of the middle cylinder 16), and the entrance gradually becomes narrower toward the back. It has a typical structure. The water first tries to pass through the filter paper 24 between the ridges of the outer circumference, so that the water enters through a wide entrance and passes between the gradually narrowing peaks of the filter paper 24. Become. At this time, the small hollow cylindrical body 20
Is applied from the outside to the inside, but since it tries to pass through a gradually narrowing portion from a wide entrance, this pressure is small, and no special load is applied to the filter paper (element) 24.

Further, when the water that has entered the inside of the large hollow cylindrical body 18 from the inner cylinder 26 via punching fills the respective gaps, the gaps are large enough to allow the water to move smoothly. And each of the four small hollow cylindrical bodies 20 has a large hollow cylindrical body 18 and an inner cylindrical 2
6. Since the sizes of the respective voids formed with respect to the other small hollow cylindrical bodies 20 are substantially equal, the intruded water does not stay at any one place, and the efficiency is well balanced as a whole. Filtration is performed.

According to this embodiment, the effective filtration area can be increased, and a plurality of (four) outflow passages 14 are provided, so that the filtration efficiency is good and the filtered water can be discharged quickly. The cost is low because the structure of the entire filter element is simple.

Further, according to the present embodiment, a large filter area of the filter paper (element) of the external pressure specification can be ensured, so that a filter element which is reasonably easy in principle and has a small pressure load can be obtained. In addition, since the entire filter element 2 includes the internal pressure type cylindrical body and the external pressure type cylindrical body, the pressure harmony in the filter element 2 is maintained, and the filter element 2 has good durability.

Further, the pitch of the filter paper 24 of the small hollow cylindrical body 20 can be made large to some extent, and the filter paper can be a W-shaped filter which is a simple folding method, so that the conventional filter paper can be used and the cost is reduced. It's cheap. Further, since only four holes of the outflow passage 30 need be formed in the conventional upper plate 4, the conventional plate can be used and the cost can be reduced.

In the above-described embodiment, the filter element 2
Although the inner cylinder 26 serving as the inflow passage 12 is provided at the center, the present invention is not limited to this, and can be applied to a coupler type.

[0038]

According to the first aspect of the present invention, since the fluid to be filtered passes through the filter paper smoothly, the effective filtration area can be increased. Further, the pressure of the entire filter element is balanced, and the amount of liquid or the like that can be filtered per unit time in the entire filter element increases, that is, the filtration efficiency is improved and the durability is improved. In addition, since a plurality of small hollow cylindrical bodies are provided, the surface area of the filter element can be significantly increased, and when the filter element is actually used, the filterable time until the filter paper is clogged with dust or the like becomes longer, The number of replacements of the filter element is small. If the filter elements have the same performance, the filter element of the present invention can be made more compact, and the work when replacing the filter element becomes easier. Also, since a considerable amount of the fluid to be filtered is filtered through the small hollow cylindrical body, the filtration area by external pressure filtration with a small pressure load can be increased, which further contributes to the durability of the filter element. Furthermore, since the filter element of the present invention does not have a partition wall or the like, the structure can be simplified, and a conventionally existing W-shaped filter paper can be used, so that the manufacturing cost can be reduced.

According to the second aspect of the present invention, the supplied fluid to be filtered uniformly fills the large hollow cylindrical body, and efficiently passes through the large hollow cylindrical body and each small hollow cylindrical body. And filtered.

According to the third aspect of the present invention, the supplied fluid to be filtered reaches each of the large and small cylindrical bodies without being largely retained in the large hollow cylindrical body, and is smoothly filtered. 4
By disposing the chrysanthemum-shaped small hollow cylindrical bodies, the effective filtration area can be increased and the filtration efficiency can be improved. Also, the pitch of the filter paper does not need to be so small, and the filter paper to be used is a chrysanthemum flower shape for both the large hollow cylindrical body and the four small hollow cylindrical bodies. Can be done, convenient and low cost.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view showing a conventional filter element of an internal / external pressure type and of a coupler type.

FIG. 2 is a longitudinal sectional view showing a conventional inner / outer pressure type filter element of a center shaft type.

FIG. 3 is a perspective view showing a filter element to which the present invention is applied.

FIG. 4 is a sectional view taken along line BB of the filter element of FIG. 3;

FIG. 5 is a sectional view taken along line AA of the filter element of FIG. 3;

FIG. 6 is a partially enlarged sectional view of a large hollow cylindrical body.

FIG. 7 is a partially enlarged sectional view of a small hollow cylindrical body.

[Explanation of symbols]

 2 Filter element 12 Inflow passage 14 Outflow passage 16 Middle cylinder 18 Large hollow cylinder 20 Small hollow cylinder 22 Filter paper 24 Filter paper 26 Inner cylinder

Claims (3)

[Claims] 1. A filter element for filtering a fluid, comprising: a large hollow cylindrical body formed by folding a filter paper continuously folded in a W shape into a pleated shape so that a cross section thereof is substantially chrysanthemum flower shape; An inflow passage provided inside the large hollow cylindrical body for supplying a fluid to be filtered; and a filter paper provided inside the large hollow cylindrical body and continuously folded into a W shape to have a pleated shape. A plurality of small hollow cylindrical bodies formed so as to have a substantially chrysanthemum flower shape and having an outflow passage formed in the substantially chrysanthemum flower-shaped shaft portion. 2. The filter element according to claim 1, wherein said inflow passage is provided in a shaft portion of said large hollow cylindrical body. 3. A plurality of small hollow cylinders, each of which has a plurality of small hollow cylindrical members, each of which is disposed at substantially the same radial distance from a shaft of the large hollow cylindrical member. The filter element according to claim 1, wherein the filter element is made of a shape.