TWI840228B - Filter unit and filter box - Google Patents

Abstract

A filter unit and a filter box, the filter unit includes a filter module and a filter material expansion module; the filter module has an outer filter component and an inner filter component, and a filter space is formed between the outer filter component and the inner filter component; the filter material expansion module is combined with one of the outer filter component and the inner filter component, and the filter material expansion module has an expansion space connected to the filter space The filter box includes the aforementioned filter unit and a fixed unit, the fixed unit includes a plurality of fixed side frames and a mounting frame, and every two fixed side frames are respectively assembled on both sides of the filter module to fix the outer filter assembly and the inner filter assembly. The filter unit is fixed in the mounting frame by the fixed side frames to increase the internal space volume of the filter unit and improve the filtering performance.

Description

Filter unit and filter box

The present invention relates to air filtration technology, and in particular to a filter unit and a filter box thereof.

Currently, in many manufacturing fields of optoelectronics, precision industry and semiconductor industries, in order to meet product production requirements, production and manufacturing are usually carried out in clean, pollution-free and isolated dust-free spaces.

The dust-free space environment usually has a fan and air filter equipment installed at the air inlet, so that the airflow is driven by the fan and filtered by the air filter equipment to prevent suspended objects in the airflow from entering the dust-free space.

Generally speaking, the basic structure of the filter assembly in the air filter device includes two sheet filters and a filter disposed between the two filter materials. Since the internal space of the filter assembly is formed according to the spacing between the two filter materials, and the two filter materials do not have an area for expanding the area, the internal space volume of the filter assembly is limited by the shape of the two filter materials, and therefore the filling amount of the filter material cannot be increased, which reduces the service life of the filter assembly and wastes the replacement cost of the filter assembly.

In view of this, the purpose of the present invention is to provide a filter unit and a filter box thereof, which increases the internal space volume of the filter unit, not only improves the filtering performance, but also prolongs the service life.

In order to achieve the above-mentioned purpose, the filter unit provided by the present invention includes a filter module and a filter material expansion module; the filter module has an outer filter component and an inner filter component, the outer filter component and the inner filter component are arranged at intervals to form a filter space; the filter material expansion module is combined with one of the outer filter component and the inner filter component in the filter module, and the filter material expansion module has an expansion space corresponding to the inside of the filter module and connected to the filter space.

In one embodiment, the filter material expansion module includes at least one first expansion portion and at least one second expansion portion, the first expansion portion is integrally formed on the outer filter component, and the second expansion portion is integrally formed on the inner filter component.

In one embodiment, the outer filter assembly has an outer filter surface, the inner filter assembly has an inner filter surface, the first expansion portion and the second expansion portion are respectively combined on the outer filter surface and the inner filter surface with a concave-convex structure, and the expansion space is formed between the first expansion portion and the second expansion portion.

In one embodiment, the first expansion portion has a convex section that protrudes outward relative to the outer filter surface, and the first expansion portion forms a groove inside the convex section, and the second expansion portion has a concave section that is concave into the groove relative to the inner filter surface toward the convex section of the first expansion portion.

In one embodiment, the outer filter surface has two first side ends on both sides, and the outer filter surface has a first straight end connecting the two first side ends, the first expansion portion is formed on the outer filter surface corresponding to the extension direction of the first straight end to connect the two first side ends, and the outer filter surface is divided by the first expansion portion to form a plurality of outer filter sections located on both sides of the first expansion portion; the inner filter surface has two first side ends connected to the first straight end. The inner filter surface has two second side ends, and the inner filter surface has a second straight end connecting the two second side ends. The second expansion portion is formed on the inner filter surface corresponding to the extension direction of the second straight end to connect the two second side ends, and the inner filter surface is divided by the second expansion portion to form a plurality of inner filter sections located on both sides of the second expansion portion, wherein the inner filter sections and the outer filter sections face each other.

In one embodiment, the first expansion portion has two first coupling sections corresponding to the two first side ends on the same side of the outer filter surface, and the second expansion portion has two second coupling sections corresponding to the two second side ends on the same side of the inner filter surface, and the two first coupling sections and the two second coupling sections are in contact with each other.

In one embodiment, the outer filter assembly includes a first outer filter and a second outer filter, one end of the first outer filter is combined with one end of the second outer filter, and the first outer filter and the second outer filter are inclined outward to form an open groove; the inner filter assembly is accommodated in the open groove of the outer filter assembly, and the inner filter assembly includes a first inner filter and a second inner filter. Two inner filters, one end of the first inner filter is combined with one end of the second inner filter, and the first inner filter and the second inner filter are respectively inclined outward corresponding to the first outer filter and the second outer filter, so that a first filter space is formed between the first outer filter and the first inner filter, and a second filter space is respectively formed between the second outer filter and the second inner filter.

In one embodiment, the outer filter assembly includes a base filter, and the two sides of the base filter are respectively combined with the first outer filter and the second outer filter; the inner filter assembly includes a connecting filter, the connecting filter faces the base filter, and the two sides of the connecting filter are respectively combined with the first inner filter and the second inner filter, wherein a connecting space is formed between the connecting filter and the base filter, and the first filter space and the second filter space are connected to each other through the connecting space.

In one embodiment, the outer filter component has a plurality of outer joints, which are respectively arranged at two first side ends of the outer filter surface corresponding to each of the outer filter sections; the inner filter component has a plurality of inner joints, which are respectively arranged at two second side ends of the inner filter surface corresponding to each of the inner filter sections, and each of the outer joints is connected to each of the inner joints.

The present invention provides a filter box provided by another embodiment, comprising the aforementioned filter unit and a fixing unit; the fixing unit fixes the filter unit, the fixing unit comprises a plurality of fixing side frames and a mounting frame, each two fixing side frames are respectively assembled on the two sides of the filter module to fix the outer filter assembly and the inner filter assembly, the mounting frame has a mounting space, the mounting frame is locked to the fixing side frames, so that the filter unit is fixed in the mounting space of the mounting frame by the fixing side frames.

In one embodiment, each of the two fixed side frames is fixed on the two sides of the outer filter assembly, and each of the fixed side frames includes a positioning plate, and the positioning plate has a flange that abuts against the outer filter assembly. Further, the flange includes two side edges, a bottom edge and a top edge, and the two side edges have two side blocks to abut against the periphery of the outer filter surface of the first outer filter and the second outer filter, and the bottom edge has an ancillary block connecting the two side blocks, and the ancillary block correspondingly abuts against the periphery of the base filter.

In one embodiment, the mounting frame has two mounting support rods, and the filter units are multiple and adjacent to each other and arranged between the two mounting support rods, and each of the filter units is fixed to the two mounting support rods by two fixed side frames.

The effect of the present invention is that the filter unit forms an expansion space inside the filter module corresponding to the filter module through the structural design of the filter module and the filter material expansion module, thereby increasing the volume of the internal space of the filter unit, thereby increasing the filling amount of the filter material in the filter unit, and further improving the filtering performance of the filter box, and extending the service life of the filter units, thereby achieving the purpose of saving the replacement cost of the filter unit.

[The present invention]

100: Filter box

10: Filter unit

11: Filter module

111: External filter assembly

111a: First outer filter

111b: Second outer filter

111c: Base filter

111d: Open slot

112: Inner filter assembly

112a: First inner filter

112b: Second inner filter

112c: Connect filter

112d: Open space

113: External filter surface

113a: External filter section

1131: First side

1132: First straight end

114: Outer junction

115: External fixing part

116: Inner filter surface

116a: Inner filter section

1161: Second side

1162: Second straight end

117: medial junction

12: Filter expansion module

121: First expansion unit

121a: convex section

121b: First binding segment

122: Second expansion unit

122a: Concave section

122b: Second binding segment

20: Fixed unit

21:Fix the side frame

211: Positioning plate

2111: Side edge

2112: Background

2113: Top Edge

212: Side block

213: Joint block

214: Alignment hole

22: Install the frame

221: Install the support rod

2211: Keyhole

222: Connecting rod

223: Installation space

23: Cover plate

231: First cover plate

2311: Cover frame

2312: Connecting rod

232: Second cover plate

S: Filter space

S1: First filtering space

S2: Second filtering space

S3: Connected Space

P: Expandable space

1: Filter material

Figure 1 is a three-dimensional diagram of the filter unit of the first preferred embodiment of the present invention.

Figure 2 is a structural exploded view of the filter unit of the first preferred embodiment of the present invention.

Figure 3 is a side view of the outer filter assembly in the filter unit of the first preferred embodiment of the present invention.

FIG4 is a side view of the inner filter assembly in the filter unit of the first preferred embodiment of the present invention.

Figure 5 is a front view of the filter unit of the first preferred embodiment of the present invention.

Figure 6 is a cross-sectional schematic diagram of the filter unit of the first preferred embodiment of the present invention.

Figure 7 is a partial enlarged view of the area marked A in Figure 6.

FIG8A is another schematic diagram of the surface area expansion portion of the filter unit in the first preferred embodiment of the present invention.

FIG8B is another schematic diagram of the surface area expansion portion of the filter unit in the first preferred embodiment of the present invention.

Figure 9 is a three-dimensional diagram of the filter box of the second preferred embodiment of the present invention.

Figure 10 is a structural exploded view of the filter box of the second preferred embodiment of the present invention.

Figure 11 is a structural exploded view of the fixed side panels and filter unit in the filter box of the second preferred embodiment of the present invention.

Figure 12 is a partial front view of the filter box of the second preferred embodiment of the present invention.

Figure 13 is a partial top view of the filter box of the second preferred embodiment of the present invention.

Figure 14 is a partial bottom view of the filter box of the second preferred embodiment of the present invention.

Figure 15 is a partial cross-sectional schematic diagram of the filter box of the second preferred embodiment of the present invention.

In order to explain the present invention more clearly, a preferred embodiment is given and described in detail with reference to the drawings. Figures 1 and 2 show the first preferred embodiment of the present invention, which provides a basic structure of a filter unit 10.

The filter unit 10 provided in the first embodiment includes a filter module 11 and a filter material expansion module 12.

The filter module 11 has an outer filter component 111 and an inner filter component 112. The outer filter component 111 and the inner filter component 112 are arranged at intervals, so that a filter space S is formed between the outer filter component 111 and the inner filter component 112. The filter space S is used to fill a filter material 1 (see Figure 15). In this embodiment, the outer filter component 111 and the inner filter component 112 can be made of, but not limited to, a plate having a plurality of filter meshes in a partial surface area.

2 and 3, the detailed structure of the outer filter assembly 111 is described. The outer filter assembly 111 has an outer filter surface 113, wherein the outer filter assembly 111 includes a first outer filter 111a and a second outer filter 111b, one end of the first outer filter 111a is combined with one end of the second outer filter 111b. In this embodiment, the outer filter assembly 111 includes a base filter 111c. The first outer filter 111a and the second outer filter 111b are respectively combined on both sides of 11c, that is, the first outer filter 111a and the second outer filter 111b are combined together through the base filter 111c, wherein the first outer filter 111a and the second outer filter 111b are respectively tilted outward, and the first outer filter 111a, the second outer filter 111b and the base filter 111c enclose an open slot 111d.

Specifically, the first outer filter 111a and the second outer filter 111b each have an outer filter surface 113, as shown in FIG3 , the two sides of the outer filter surface 113 have two first side ends 1131, and the top side of the outer filter surface 113 has a first straight end 1132 connecting the two first side ends 1131, as shown in FIGS. 2 , 3 and 5 , the first outer filter 111a and the second outer filter 111b each have a plurality of outer coupling portions 114, and the outer The coupling parts 114 are respectively disposed at the two first side ends 1131 of the outer filter surface 113, and the outer coupling parts 114 extend inwardly toward the open groove 111d relative to the outer filter surface 113, wherein the two ends of the base filter 111c have two outer fixing parts 115, and the two outer fixing parts 115 extend upward toward the open groove 111d, and the two outer fixing parts 115 are adjacent to the outer coupling parts 114 of the first outer filter 111a and the second outer filter 111b.

2 and 4, the detailed structure of the inner filter assembly 112 is described. The inner filter assembly 112 has an inner filter surface 116, wherein the inner filter assembly 112 is accommodated in the open groove 111d of the outer filter assembly 111. The inner filter assembly 112 includes a first inner filter 112a and a second inner filter 112b. One end of the first inner filter 112a is combined with one end of the second inner filter 112b. In this embodiment, the inner filter assembly 112 includes A connecting filter 112c, the connecting filter 112c faces the base filter 111c, and the two sides of the connecting filter 112c are respectively combined with the first inner filter 112a and the second inner filter 112b, that is, the first inner filter 112a and the second inner filter 112b are combined together through the connecting filter 112c, wherein the first inner filter 112a and the second inner filter 112b correspond to the first outer filter 111a and the second outer filter 111b and are tilted outwards.

As shown in FIGS. 5 to 7 , a first filter space S1 is formed between the first outer filter 111a and the first inner filter 112a, and a second filter space S2 is formed between the second outer filter 111b and the second inner filter 112b, respectively. At this time, a connecting space S3 is formed between the connecting filter 112c and the base filter 111c. The space S1 and the second filter space S2 are interconnected through the connecting space S3, and an open space 112d is formed between the first inner filter 112a and the second inner filter 112b in the inner filter assembly 112. The open space 112d can be connected to the filter space S inside the filter module 11 through the filter mesh holes of the inner filter assembly 112.

Specifically, the first inner filter 112a and the second inner filter 112b each have an inner filter surface 116, as shown in FIG. 4 , and the inner filter surface 116 has two second side ends 1161 on both sides, and the top side of the inner filter surface 116 has a second straight end 1162 connected to the two second side ends 1161. As shown in FIGS. 2 , 4 and 5 , the first inner filter 112a and the second inner filter 112b respectively have a plurality of inner coupling parts 117, which are respectively arranged at the two second side ends 1161 of the inner filter surface 116, and each inner coupling part 117 is correspondingly coupled to the inner wall of each outer coupling part 114, so that the outer filter assembly 111 and the inner filter assembly 112 are combined to form the filter space S.

The filter expansion module 12 is combined with one of the outer filter assembly 111 and the inner filter assembly 112 in the filter module 11. The filter expansion module 12 has an expansion space P corresponding to the inside of the filter module 11 and connected to the filter space S. The expansion space P is also used to fill the filter (not shown in the figure). As shown in Figures 2 to 5, in this embodiment, the filter module 11 and the filter expansion module 12 are integrally stamped. The filter expansion module 12 includes a plurality of first expansion parts. 121 and a plurality of second expansion parts 122, each of the first expansion parts 121 is formed integrally on the first outer filter 111a and the second outer filter 111b of the outer filter assembly 111, and each of the second expansion parts 122 is formed integrally on the first inner filter 112a and the second inner filter 112b of the inner filter assembly 112, and the first expansion part 121 and the second expansion part 122 are both filter types, allowing external air to pass through to enter the expansion space P.

In other embodiments, the filter expansion module 12 can be adjusted according to structural requirements. For example, the filter expansion module 12 only needs at least one of the first expansion part 121 and the second expansion part 122, or the filter expansion module 12 can omit one of the first expansion part 121 and the second expansion part 122. As long as the filter expansion module 12 can pass the outer side The expansion space P is formed on the filter assembly 111 or the inner filter assembly 112; the filter material expansion module 12 and the filter module 11 are not limited to be integrally formed, and the filter material expansion module 12 can also be set on the outer filter assembly 111 or the inner filter assembly 112 of the filter module 11 through other combination methods, as long as the expansion space P is connected to the filter space S.

2 to 7, in this embodiment, the first expansion portion 121 and the second expansion portion 122 are respectively combined on the outer filter surface 113 and the inner filter surface 116 with a concave-convex structure. As shown in FIGS. 6 and 7, the first expansion portion 121 has a convex section 121a, and the convex section 121a is protruding outward relative to the outer filter surface 113, and the first expansion portion 121 forms a receiving groove on the inner side of the convex section 121a, and the second expansion portion 122 is The concave section 122a is recessed into the receiving groove with the convex section 121a facing the first expansion part 121 relative to the inner filter surface 116, so that the first expansion part 121 and the second expansion part 122 form a rectangular concave-convex pair, and the expansion space P is provided between the first expansion part 121 and the second expansion part 122, so as to increase the volume of the internal space of the filter unit 10, thereby increasing the filling amount of the filter material in the filter unit 10.

In other embodiments, the concave-convex configuration of the first expansion portion 121 and the second expansion portion 122 can be adjusted to other forms according to needs. As shown in Figures 8A and 8B, the first expansion portion 121' and the second expansion portion 122' in the filter expansion module 12' can be paired in an angle or arc shape; or, the first expansion portion 121 can be replaced by being arranged on the inner filter component 112, and the second expansion portion 122 can be replaced by being arranged on the outer filter component 111; in addition, the first expansion portion 121 and the second expansion portion 122 are both designed as convex portions, and the first expansion portion 121 and the second expansion portion 122 can be arranged in a staggered manner relative to each other.

As shown in Figures 2 and 3, the structural type of the first expansion portion 121 on the outer filter surface 113 is formed on the outer filter surface 113 by connecting the two first side ends 1131 in the extension direction of the first straight end 1132, and the first expansion portion 121 has two first connecting sections 121b corresponding to the two first side ends 1131 on the same side of the outer filter surface 113. At this time, the outer filter surface 113 is divided by the first expansion portion 121 to form a plurality of outer filter sections 113a located on both sides of the first expansion portion 121.

As shown in FIGS. 2 and 4 , the second expansion portion 122 is formed on the inner filter surface 116 in a structure that corresponds to the extension direction of the second straight end 1162 to connect the two second side ends 1161, and the second expansion portion 122 has two second connecting sections 122b corresponding to the two second side ends 1161 on the same side of the inner filter surface 116, and the two first connecting sections 121b and the two second connecting sections 122 b are pressed against each other, and at this time, the inner filter surface 116 is divided by the second expansion part 122 to form a plurality of inner filter sections 116a located on both sides of the second expansion part 122, and the inner filter sections 116a and the outer filter sections 113a face each other; thus, the structural design of the first expansion part 121 and the second expansion part 122 is for the purpose of effectively expanding the internal space of the filter unit 10, but is not limited thereto.

Thus, the filter unit 10 is designed by the structure of the filter module 11 and the filter material expansion module 12. The filter material expansion module 12 forms the expansion space P inside the filter module 11, which increases the volume of the internal space of the filter unit 10, thereby increasing the filling amount of the filter material in the filter unit 10, thereby improving the filtering performance of the filter unit 10. Since the filled filter material can be effectively increased, the service life of the filter unit 10 can be improved, and the replacement cost of the filter unit 10 can be reduced.

Please refer to Figures 9 to 15 for showing the second preferred embodiment of the present invention, which provides a basic structure of a filter box 100, wherein the filter box 100 includes a plurality of filter units 10 and a fixed unit 20.

The basic structure of the filter units 10 is the same as that of the first embodiment. The filter unit 10 includes the filter module 11 and the filter expansion module 12. The outer filter component 111 and the inner filter component 112 are arranged at intervals in the filter module 11 to form the filter space S. The filter expansion module 12 is combined with one of the outer filter component 111 and the inner filter component 112 in the filter module 11. The expansion module 12 has the expansion space P corresponding to the filter module 11, and the expansion space P is connected to the filter space S. FIG15 shows that the expansion space P and the filter space S in each filter unit 10 are filled with the filter material 1. The filter expansion module 12 is added to increase the volume of the internal space of the filter unit 10, thereby increasing the filling amount of the filter material 1 in the filter unit 10, thereby improving the filtering performance of the filter unit 10.

The detailed structures of the filter module 11 and the filter material expansion module 12 in the filter unit 10 of the second embodiment are the same as those of the filter unit 10 in the first embodiment; in addition, in other embodiments, the number of the filter units 10 in the filter box 100 can be adjusted according to demand.

The fixing unit 20 is used to position the filter units 10, and the fixing unit 20 includes a plurality of fixing side frames 21, a mounting frame 22 and a plurality of cover plates 23.

As shown in FIGS. 9 to 11 , each two fixed side frames 21 are respectively assembled on the two sides of the filter module 11 to fix the outer filter assembly 111 and the inner filter assembly 112. In this embodiment, each two fixed side frames 21 are respectively fixed on the two sides of the outer filter assembly 111, wherein each of the fixed side frames 21 includes a positioning plate 211, and the positioning plate 211 is attached to the outer filter assembly 111. The outer side joint portion 114 of the outer filter assembly 111 is pressed against the outer side joint portion 114 of the outer filter assembly 111 to block the two sides of the open space 112d of the inner filter assembly 112; further, the positioning plate 211 has a flange that abuts against the outer filter assembly 111 to support the outer filter assembly 111. In this embodiment, as shown in Figures 10, 11 and 14, the flange of the positioning plate 211 includes two The outer filter assembly 111 has a side edge 2111, a bottom edge 2112 and a top edge 2113. The side edges 2111 have two side baffles 212. The two side baffles 212 are used to abut against the outer filter surface 113 of the first outer filter 111a and the second outer filter 111b in the outer filter assembly 111. The bottom edge 2112 has a connecting baffle 213 (see FIG. 11, 14), the connecting block 213 connects the two side blocks 212, and the connecting block 213 corresponds to the periphery of the base filter 111c. The top edge 2113 is provided with a plurality of alignment holes 214, and the alignment holes 214 are connected to the open space 112d between the first inner filter 112a and the second inner filter 112b in the inner filter assembly 112.

The mounting frame 22 has two mounting rods 221 and two connecting rods 222. The two mounting rods 221 and the two connecting rods 222 are combined to enclose a mounting space 223. As shown in FIGS. 9 and 10, the filter units 10 are adjacent to each other and arranged between the two mounting rods 221. The two adjacent filter units 10 are connected by the first outer filter screen 111a of one filter module 11 and the second outer filter screen 111b of the other filter module 11. As shown in Figures 10-12, each mounting support rod 221 is provided with a plurality of lock holes 2211 corresponding to the alignment holes 214 of each fixed side frame 21, so that a lock (not shown in the figure) can be passed through, so that the mounting frame 22 is locked to the fixed side frames 21, and the filter units 10 are fixed on the two mounting support rods 221 through each two fixed side frames 21, and the filter units 10 are positioned in the mounting space 223 of the mounting frame 22.

As shown in FIGS. 10, 13 and 15, the cover plate 23 covers the top opening of each filter module 11. In this embodiment, the cover plate 23 includes a plurality of first cover plates 231 and at least one second cover plate 232. Each of the first cover plates 231 has two cover frames 2311 and two connecting rods 2312. The two cover frames 2311 are parallel to each other. The two connecting rods 2312 are respectively connected to the two covering frames 2311, wherein one covering frame 2311 is fixed to the inner filter assembly 112 of one of the filter units 10 adjacent to the mounting frame 22 and the connecting support rod 222, and the other covering frame 2311 is fixed to the inner filter assembly 112 of the adjacent filter unit 10 relative to the connecting support rod 222. The second cover plate 232 is located between the first cover plates 231 and the side filter assembly 112 and the inner filter assembly 112 of another filter unit 10. The second cover plate 232 is used to lock the first inner filter screen 112a of any adjacent filter unit 10 and the second inner filter screen 112b of another filter unit 10. In addition to positioning the adjacent filter units 10, it can also prevent foreign objects from directly entering the filter space S through the top opening of the filter module 11. The first cover plate 231 and the second cover plate 232 in the cover plate 23 can be detachably fixed to the mounting support rod 221 of the mounting frame 22 by a fastener (not shown in the figure).

Thus, the structural design of the filter unit 10 in the filter box 100 and the filter material expansion module 12 can increase the volume of the internal space of the filter unit 10, thereby increasing the filling amount of the filter material 1 in the filter unit 10. In addition, the surface area of the filter box 100 that can be filtered and the cross-sectional area of the gas passing through can be increased, thereby reducing the increase in pressure loss, and further improving the filtering performance of the filter box 100, and extending the service life of the filter units 10, so as to achieve the purpose of saving the replacement cost of the filter unit 10.

The above is only the preferred feasible embodiment of the present invention. Any equivalent changes made by applying the present invention specification and the scope of patent application should be included in the patent scope of the present invention.

10: Filter unit

11: Filter module

111: External filter assembly

111a: First outer filter

111b: Second outer filter

111c: Base filter

112: Inner filter assembly

112a: First inner filter

112b: Second inner filter

112c: Connect filter

112d: Open space

113: External filter surface

114: Outer junction

115: External fixing part

116: Inner filter surface

12: Filter expansion module

121: First expansion unit

122: Second expansion unit

Claims (9)

A filter unit comprises: a filter module having an outer filter component and an inner filter component, wherein the outer filter component and the inner filter component are spaced apart to form a filter space; and a filter material expansion module, which is combined with one of the outer filter component and the inner filter component in the filter module, wherein the filter material expansion module has an expansion space corresponding to the inside of the filter module and connected to the filter space, wherein the filter material expansion module comprises at least a first expansion portion and at least one second expansion part, the first expansion part is integrally formed on the outer filter component, the second expansion part is integrally formed on the inner filter component, wherein the outer filter component has an outer filter surface, the inner filter component has an inner filter surface, the first expansion part and the second expansion part are respectively combined on the outer filter surface and the inner filter surface with a concave-convex structure, and the expansion space is formed between the first expansion part and the second expansion part. The filter unit as described in claim 1, wherein the first expansion portion has a convex section protruding outward relative to the outer filter surface, and the first expansion portion forms a groove inside the convex section, and the second expansion portion has a concave section concave into the groove relative to the inner filter surface toward the convex section of the first expansion portion. The filter unit as described in claim 1, wherein the outer filter surface has two first side ends on both sides, and the outer filter surface has a first straight end connecting the two first side ends, the first expansion portion is formed on the outer filter surface corresponding to the extension direction of the first straight end to connect the two first side ends, and the outer filter surface is divided by the first expansion portion to form a plurality of outer filter sections located on both sides of the first expansion portion; the inner filter The inner filter surface has two second side ends on both sides, and the inner filter surface has a second straight end connecting the two second side ends, the second expansion portion is formed on the inner filter surface corresponding to the extension direction of the second straight end to connect the two second side ends, and the inner filter surface is divided by the second expansion portion to form a plurality of inner filter sections located on both sides of the second expansion portion, wherein the inner filter sections and the outer filter sections face each other. The filter unit as described in claim 3, wherein the first expansion portion has two first coupling sections corresponding to the two first side ends on the same side of the outer filter surface, and the second expansion portion has two second coupling sections corresponding to the two second side ends on the same side of the inner filter surface, and the two first coupling sections and the two second coupling sections are in contact with each other. A filter unit as described in claim 3, wherein the outer filter assembly includes a first outer filter and a second outer filter, one end of the first outer filter is combined with one end of the second outer filter, and the first outer filter and the second outer filter are respectively inclined outward to form an open groove; the inner filter assembly is accommodated in the open groove of the outer filter assembly, and the inner filter assembly includes a first inner filter and a second inner filter, one end of the first inner filter is combined with one end of the second inner filter, and the first inner filter and the second inner filter are inclined outwardly corresponding to the first outer filter and the second outer filter respectively, so that a first filter space is formed between the first outer filter and the first inner filter, and a second filter space is formed between the second outer filter and the second inner filter respectively. The filter unit as described in claim 5, wherein the outer filter assembly includes a base filter, the two sides of which are respectively combined with the first outer filter and the second outer filter; the inner filter assembly includes a connecting filter, the connecting filter faces the base filter, and the two sides of which are respectively combined with the first inner filter and the second inner filter, wherein a connecting space is formed between the connecting filter and the base filter, and the first filter space and the second filter space are connected to each other through the connecting space. A filter box, comprising: at least one filter unit as described in any one of claims 1 to 6, comprising a filter module and a filter material expansion module, the filter module having an outer filter component and an inner filter component, the outer filter component and the inner filter component are spaced apart to form a filter space between the outer filter component and the inner filter component; the filter material expansion module is combined with one of the outer filter component and the inner filter component in the filter module, the filter material expansion module The module has an expansion space corresponding to the filter module and connected to the filter space; and a fixing unit to fix the filter unit. The fixing unit includes a plurality of fixing side frames and a mounting frame. Every two fixing side frames are respectively assembled on the two sides of the filter module to fix the outer filter assembly and the inner filter assembly. The mounting frame has a mounting space. The mounting frame is connected to the fixing side frames so that the filter unit is fixed in the mounting space of the mounting frame through the fixing side frames. A filter box as described in claim 7, wherein each of the two fixed side frames is fixed to the two sides of the outer filter assembly, and each of the fixed side frames includes a positioning plate having a flange that abuts against the outer filter assembly. The filter box as described in claim 7, wherein the mounting frame has two mounting support rods, the filter units are multiple and adjacently arranged between the two mounting support rods, and each of the filter units is fixed to the two mounting support rods by each two fixed side frames.