HK1178481A - Air filter insert - Google Patents

Description

Air filter insert

Technical Field

The present invention relates to an air filter insert used for collecting fine particles in air for use in building air conditioning, industrial air conditioning, and the like, and more particularly to an air filter insert in which a filter sheet is folded into a pleated shape to form a block shape.

Background

Conventionally, in order to remove dust and contaminants in air, an air filter in which an air filter insert having a pleated filter sheet is housed inside a filter frame has been widely used. Air filter inserts are typically provided with spacers to maintain spacing between the folded filter sheets to ensure ventilation.

For example, a protrusion formed on the filter sheet by embossing is used as the spacer. Among the projections formed by embossing, the projections provided between adjacent filter sheets project so as to be close to each other, and the leading end surfaces thereof are in contact with each other.

Prior patent literature

Patent document

Patent document 1: japanese patent No. 2935432

Patent document 2: japanese patent No. 2935433

Disclosure of Invention

(problems to be solved by the invention)

When the filter sheet is subjected to the embossing process, the design is made in consideration of the extension formed by the embossing. That is, the filter sheet is designed to have a thickness or a weight per unit area (weight per unit area) capable of securing a minimum required filtration performance even if it is stretched and thinned by embossing.

However, in such a design, since the portion that is not extended is excessively thick by embossing, excessive filtering performance is given to the filter, so that the pressure loss becomes large, and the filtering performance is impaired. In addition, in order to improve the filtration performance, it is considered to increase the effective filtration area of the filter medium, but a method of increasing the effective filtration area of the filter medium by a simple method has not been found in the prior art.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an air filter insert which has a high filtering performance by suppressing the pressure loss of a filter medium to a low level and increasing the effective filtering area of the filter medium by a simple method.

(means for solving the problems)

An air filter insert according to the present invention is an air filter insert having a block-like structure for filtering air by folding a filter sheet into a pleated shape, wherein the filter sheet is folded to form a plurality of folded walls, and on the folded walls, a 1 st protruding portion and a 2 nd protruding portion formed by embossing are arranged in a folding direction, and the 1 st protruding portion provided on a pair of adjacent folded walls is protruded so as to be close to each other, and the 2 nd protruding portion is protruded so as not to be butted against each other while the leading ends thereof are butted against each other.

Preferably, the 2 nd projecting portions are arranged at the same position in the folding line direction and project in the same direction. In this case, it is more preferable that a part of each of the 2 nd projecting portions provided on the folded wall is disposed inside the 2 nd projecting portion provided on the folded wall adjacent to the folded wall. And, the 2 nd protruding part protruding in one direction and the 2 nd protruding part protruding in the opposite direction thereof may be alternately arranged in the folding line direction. Also, the 2 nd protrusions may protrude without contacting each other.

The projection height of the 2 nd projection may be substantially constant along the length direction thereof. Also, the front end surface of the 2 nd projecting portion may be a plane parallel to the folded wall. Preferably, the 2 nd projecting portion has a shape extending perpendicularly to the fold line on each of the fold walls. One of the cross-sectional shape and the longitudinal sectional shape of the 2 nd projecting portion is a trapezoid, and preferably both are trapezoids.

Preferably, the 1 st protruding portion extends perpendicularly to the fold line on each fold wall, and the protruding height thereof increases in the longitudinal direction thereof, for example, as in the 2 nd protruding portion. The 1 st and 2 nd protrusions are alternately arranged in the direction of the fold, for example.

(Effect of the invention)

In the present invention, by providing the 2 nd protrusion, the effective filtration area of the filter medium can be increased while suppressing the pressure loss to a low level in a simple manner in the air filter insert.

Drawings

Fig. 1 is an overall view of an air filter.

Fig. 2 is a perspective view showing the filter sheet before folding.

Fig. 3 is an enlarged perspective view of the air filter insert.

Fig. 4 is a cross-sectional view of fig. 3, viewed in the direction of the arrows IV-IV.

Fig. 5 is a cross-sectional view of fig. 3 viewed in the direction of the arrow V-V.

Fig. 6 is a side view showing the air filter insert with the 1 st projection omitted.

Description of the symbols

12 air filter insert

13 Filter disc

14 folding wall

21 st projection

22 nd 2 nd projection.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a perspective view showing an air filter according to an embodiment of the present invention.

The air filter 10 includes an air filter insert 12 for filtering air and an air filter frame 11 for holding the air filter insert 12, and is configured by inserting the air filter insert 12 into the air filter frame 11. The air filter frame 11 is formed in a quadrangular frame shape from metal such as wood or aluminum. The air filter insert 12 is a filter medium in which the filter sheet 13 is folded into a pleated shape to form a block shape.

Next, the structure of the air filter insert 12 will be described in more detail. As shown in fig. 2, the filter sheet 13 is folded in a pleated shape (zigzag shape) at a constant folding height along a fold S extending in the width direction of the filter sheet 13. As shown in fig. 3, the air filter insert 12 is folded into a pleated shape by the filter sheet 13, and has a structure in which a plurality of planar folding walls 14 are overlapped. In the following description, the direction in which the folding walls 14 overlap is defined as the X direction. As shown in fig. 3, in the air filter insert 12, air passes from the front surface 13A to the back surface 13B of the filter sheet 13. That is, the ventilation direction is from the upper side to the lower side in fig. 3.

The filter sheet 13 may be any filter material as long as it can filter airborne particles in the air and can be formed into the air filter insert 12. For example, the filter sheet 13 may be made of a filter paper made of glass fiber, or a nonwoven fabric made of polyolefin or polyester, and is not particularly limited as long as it satisfies the filtering performance.

The filter sheet 13 is provided with a plurality of 1 st and 2 nd protrusions 21 and 22 formed by embossing. The filter sheet 13 is fed, for example, in the longitudinal direction between two rollers having projections and recesses on the outer peripheral surface thereof, and embossing is performed between the two rollers. As shown in fig. 2, the 1 st and 2 nd protrusions 21 and 22 are recessed from one surface side (the front surface 13A or the rear surface 13B side) of the filter sheet 13 and protrude from the other surface side (the rear surface 13B or the front surface 13A side).

The 1 st projecting portion 21 and the 2 nd projecting portion 22 are alternately arranged in the folding direction (the width direction of the filter sheet 13) on each folding wall 14. The interval in the direction of the fold line of the 1 st protruding part 21 is preferably 25 to 75mm, and more preferably about 50 mm. The interval in the direction of folding of the 2 nd projecting part 22 is also preferably 25 to 75mm, more preferably about 50 mm.

The 1 st and 2 nd projecting portions 21 and 22 provided on each folding wall 14 are arranged at the same positions in the folding direction as the 1 st and 2 nd projecting portions 21 and 22 provided on the other folding wall 14, respectively. That is, in the filter sheet 13, as shown in fig. 2, the 1 st protruding portion 21 and the 2 nd protruding portion 22 aligned in a row in the longitudinal direction of the filter sheet 13 are alternately aligned in the folding line direction.

The 1 st protruding portion 21 is arranged in a plurality in the folding line direction so as to protrude alternately from the front surface 13A side and the back surface 13B side on each folding wall 14. The plurality of 1 st projecting portions 21 provided at the same position in the folding line direction (i.e., arranged in the longitudinal direction of the filter sheet 13) project on the same surface side (the front surface 13A side or the back surface 13B side) of the filter sheet 13. Therefore, as shown in fig. 3, the plurality of 1 st projecting portions 21 provided at the same position in the folding line direction alternately project in one direction along the X direction and in the opposite direction when folded in a pleated shape.

With such a structure, the 1 st projecting portion 21 projects on the pair of adjacent folded walls 14, 14 so as to approach each other, and the distal end surfaces 21A, 21A thereof abut against each other. The front end surfaces 21A, 21A that are in contact with each other are fixed by an adhesive (not shown) applied therebetween, whereby the adjacent folding walls 14, 14 are kept separated from each other. The 1 st projecting portion 21 projecting toward the front surface 13A keeps the front surfaces 13A, 13A of the folded walls 14, 14 apart, and the 1 st projecting portion 21 projecting toward the rear surface 13B keeps the rear surfaces 13B, 13B of the folded walls 14, 14 apart.

The plurality of 2 nd projecting portions 22 arranged at the same position in the folding line direction (i.e., arranged in the longitudinal direction of the filter sheet 13) project alternately on the front surface 13A side and the back surface 13B side in the longitudinal direction of the filter sheet 13. Therefore, the 2 nd projecting portions 22 arranged at the same position in the folding line direction project in the same direction along the X direction when pleated, and do not abut against each other in the air filter insert 12.

Similarly to the first projecting portion 21, the 2 nd projecting portion 22 is arranged in a plurality in the folding line direction so as to alternately project on the front surface 13A side and the rear surface 13B side in each folding wall 14. Therefore, as shown in fig. 3, in the air filter insert 12, the 2 nd projecting part 22 projecting in one direction along the X direction and the 2 nd projecting part 22 projecting in the opposite direction thereof are alternately arranged in the fold line direction.

The protrusions 21 and 22 of the 1 st and 2 nd have a shape extending perpendicular to the fold S in each of the folding walls 14. That is, the projections 21, 22 extend in the longitudinal direction of the filter sheet 13 and extend in the air filter insert 12 slightly obliquely with respect to the ventilation direction.

The 1 st projecting portion 21 is connected to the adjacent 1 st projecting portion 21 at the fold S, and a plurality of the projecting portions are continuously arranged in the longitudinal direction of the filter sheet 13. That is, the length of the 1 st protruding part 21 is the same as the width (i.e., the folded height) of the folded wall 14. On the other hand, the 2 nd projecting portion 22 is not formed in the vicinity of the fold S, and is not connected to the adjacent 2 nd projecting portion 22 at the fold S. That is, the 2 nd protrusions 22 are discontinuously arranged in plural in the longitudinal direction of the filter sheet 13, and the length of the 2 nd protrusion 22 is 1/2 to 2/3 of the folding height.

The 1 st protruding part 21 has an increased protruding height along its length direction. Here, the 1 st protruding portion 21 protruding from the front surface 13A side gradually decreases in height in the ventilation direction, while the 1 st protruding portion 21 protruding from the rear surface 13B side gradually increases in height in the ventilation direction. Therefore, the distance between the surfaces 13A, 13A of the adjoining folding walls 14, 14 becomes gradually shorter in the ventilation direction, and the distance between the back surfaces 13B, 13B becomes gradually longer in the ventilation direction.

As shown in fig. 4 and 5, the 1 st projection 21 has a trapezoidal cross-sectional shape, and has a width gradually decreasing from the base end to the tip end, and a tip end surface 21A forming a flat surface. The width of the base end of the 1 st projection 21 is substantially constant in the longitudinal direction of the projection 21.

On the other hand, as shown in fig. 4 to 6, the 2 nd projecting portion 22 has a trapezoidal shape in cross section and in longitudinal section, and gradually decreases in width and length from the base end toward the tip end, and the tip end surface 22A forms a plane parallel to the folded wall 14. The width of the 2 nd projection 22 (for example, the width of the distal end and the width of the proximal end) is substantially constant in the longitudinal direction of the projection 22. The width of the base end of the protrusion 22 is preferably 5 to 15mm, more preferably about 10 mm.

Further, the projecting height of the 2 nd projecting part 22 is fixed in the direction perpendicular to the fold S. The projection height of the 2 nd projection 22 is a height between the height of the highest portion and the height of the lowest portion of the 1 st projection 21, and is preferably about 3 to 5mm in detail. If the height is less than 3mm, the filter area of the air filter insert 12 cannot be made sufficiently large, and if it is more than 5mm, the filter sheet may be broken during embossing.

Since the projecting height of the 2 nd projecting portion 22 is fixed, in the vicinity of the fold S, as shown in fig. 5, the leading end side thereof is arranged to be beyond the fold S when viewed from above. Here, the plurality of 2 nd projecting portions 22 arranged at the same position in the folding line direction project in the same direction in the X direction as described above, and the width and length of the 2 nd projecting portion 22 on the tip side are smaller than those on the base side. Therefore, as shown in fig. 5 and 6, a part of the tip side of the 2 nd projecting portion 22 which is beyond the fold S is accommodated in the inside (inside of the concave portion) of the base end side of the adjacent 2 nd projecting portion 22, and the 2 nd projecting portions 22 do not contact each other. As shown in fig. 6, in the present embodiment, the plurality of 2 nd projecting portions 22 arranged at the same position in the folding line direction have a structure in which one end in the longitudinal direction is arranged inside the other end of the other projecting portion 22 and one end of the other projecting portion 22 is arranged inside the other end, and this structure is repeated.

As described above, in the present embodiment, since the 2 nd projecting portions 22 are formed by embossing the portions between the 1 st projecting portions 21 as the spacers, the area of the air filter insert 12 can be increased. Since the 2 nd protrusion 22 does not abut on or contact with other protrusions, the area increased by the 2 nd protrusion 22 directly increases the effective filtration area, and the effective filtration area can be effectively increased. Further, since the thickness of the portion where the 2 nd projecting portion 22 is provided is reduced, the filtering performance is appropriate, and therefore, the pressure loss of the air filter insert 12 can be suppressed.

In the present embodiment, the 2 nd projecting portions 22 arranged at the same position in the folding line direction project in the same direction, and a part of each 2 nd projecting portion 22 is arranged inside the other 2 nd projecting portion 22. Therefore, the projecting height of each 2 nd projecting portion 22 can be made large, and the effective filtering area is easily increased. In addition, in the 2 nd protrusion 22, since the distal end surface 22A is a plane and the cross section and the longitudinal section are trapezoidal, the rigidity of each folding wall 14 can be improved while effectively increasing the filter medium area. Further, since the 2 nd protrusion 22 is substantially fixed in width and height in the length direction thereof, wind easily passes in the ventilation direction.

In the present embodiment, the 2 nd projecting part 22 facing one direction in the X direction and the 2 nd projecting part 22 facing the opposite direction are alternately arranged in the folding direction. Therefore, the rigidity of the folded wall 14 can be further improved, and the wind can be easily made to uniformly pass through the air filter insertion body 12.

Claims (12)

1. An air filter insert having a block-like configuration for filtering air by folding a filter sheet into pleats, said air filter insert characterized by,

the filter sheet is folded to form a plurality of folding walls, on which the 1 st protruding part and the 2 nd protruding part formed by embossing are arranged in the folding line direction,

the 1 st projecting portions provided on the pair of adjacent folding walls project so as to approach each other, and the leading ends abut against each other, and at the same time,

the 2 nd protruding parts protrude so as not to abut against each other.

2. The air filter insert of claim 1, wherein the 2 nd protrusions are disposed at the same position in the direction of the fold and protrude in the same direction.

3. An air filter insert according to claim 2, wherein a portion of each of the 2 nd protrusions provided on the folded wall is disposed inside the 2 nd protrusion provided on the folded wall adjacent to the folded wall.

4. The air filter insert of claim 2, wherein the 2 nd tab protruding in one direction and the 2 nd tab protruding in an opposite direction thereof are alternately arranged in a crease direction.

5. The air filter insert of claim 1, wherein the 2 nd protrusions protrude in a non-contacting manner with respect to each other.

6. An air filter insert according to claim 1 wherein the 2 nd tab has a shape on each of the folds that extends perpendicular relative to the fold.

7. The air filter insert of claim 6, wherein at least one of the cross-sectional shape and the longitudinal cross-sectional shape of the 2 nd projection is trapezoidal.

8. The air filter insert of claim 7, wherein the 2 nd protrusion is trapezoidal in cross-sectional shape as well as in longitudinal cross-sectional shape.

9. The air filter insert of claim 6, wherein the 2 nd tab has a substantially constant projection height along its length.

10. The air filter insert of claim 1, wherein the front face of the 2 nd tab is a plane parallel to the pleated wall.

11. An air filter insert according to claim 1 wherein the 1 st tab extends perpendicularly relative to the fold on each of the folded walls and the tab height increases along its length.

12. An air filter insert according to claim 1, wherein the 1 st and 2 nd protrusions alternate in the direction of the fold.