JPH0414110Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an air filter for use in automobile engines and the like.

[Prior Art] Fig. 7 and Fig. 8 are accompanying drawings of the prior invention "JP-A-59-19518" by the inventor of the present application, and show a side cross section of an air filter and a side cross section of a filter cover, respectively. .

A purified air inlet 102 is provided on the outer peripheral surface of a cylindrical filter case 101, and a purified air outlet 103 is provided on the upper cylindrical end surface. A cyclone is formed as a pre-filter in the lower part of the case 101 by attaching a conical bottom plate 111 with a hollow hole 111a in the center of the lower cylinder end of the case 101. 112 is a dust pan.

The axial flow type cylindrical filter 104, which is formed by bending a filter material on a sheet, has concentric circular pleats with respect to the cylinder axis, and one end of the cylinder has a disc-shaped frame with ventilation holes. It is fixed to member 105 using an adhesive. 110 is an air inlet 102
This is a cylindrical filter cover for preventing the filter 104 from deforming due to the wind pressure of the incoming air, and for preventing coarse dust from colliding with and adhering to the filter, and has a conical bottom surface. is provided with a central hole 110a and a number of ventilation holes 110b.

The upper end periphery of the filter cover 110 is fitted into a circular groove 105a provided on the outer periphery of the frame member 105 and fixed by an adhesive method or the like. 105
b is a circular groove into which the end edge of the filter 104 is fitted together with 105a.

In order to removably attach the filter 104 and filter cover 110 inside the case 101, an assembly bolt 1 is inserted into the cylindrical member 109 coaxially fixed to the center of the frame member 105.
06 is inserted. One end of the bolt 106 is fixed to the case 101 by the fixing plate member 113, and when the wing nut 108 screwed into the thread groove provided at the other end is tightened, the wing nut 10
8 presses the lower end surface of the cylindrical member 109 upward, and this pressing force is also applied to the peripheral edge of the frame member 105, causing the frame member 105 to press against the case 101.
It is configured to be fixed to the top inner wall surface of the housing via a gasket 107.

[Problems to be solved by the invention] In the air filter having the above configuration, one of the points that is particularly important in its assembly structure is that the case 1 partitioned by the filter 104
Two compartments in 01, namely inlet 1 of the air to be purified
02 and the section connected to the purified air outlet 103 are kept airtightly separated from each other. Otherwise, contaminated air will avoid the filter layer with high ventilation resistance and bypass the gap between both compartments toward the outlet 103 side, where the pressure is lower than the inlet 102 side, and the overefficiency will be significantly impaired. become.

The above-mentioned conventional air filter still has room for improvement in terms of this airtight seal structure.
This is because, as a method for press-fitting the filter 104 to a predetermined location on the inner wall surface of the case 101, the disk-shaped filter mounting frame member 10 is used as described above.
Since the pressing force applied to the center of the frame member 105 is transmitted to the plate surface of the frame member 105 and is applied to the outer peripheral edge thereof, the bolt 106 to which the wing nut 108 that generates the pressing force is screwed If the axis of the ring-shaped gasket 107 is not correctly aligned with the axis of the disk-shaped frame member 105, it will be difficult to apply an even compressive force over the entire circumference of the ring-shaped gasket 107, and the reliability of the seal will be lost.

Furthermore, since the filter cover 110 is integrally joined to the filter 104 as a consumable part, when the filter 104 becomes damaged and needs to be replaced, the filter cover 110 must also be discarded at the same time, which is extremely wasteful.

The present invention relates to an air filter similar to that disclosed in ``Japanese Unexamined Patent Application Publication No. 59-19518,'' which makes it easier and more reliable to assemble the frame member of the filter to the inner wall of the filter case while keeping an airtight seal. To provide an air filter which can be used to replace a filter and which does not require discarding a filter cover at the same time when replacing the filter.

[Means for Solving the Problems] In order to achieve the above object, an air filter according to the present invention includes a filter case provided with an air inlet and an air outlet, an air filter disposed within the filter case covering the outlet, and an air filter provided with an air inlet and an air outlet. an axial flow type cylindrical filter in which a frame member having a flange-shaped portion in the direction of the axial flow is assembled to the cylindrical end surface of the outlet; a cylindrical filter cover for protecting the outer peripheral surface of the filter; and an axis of the filter and the filter cover. A bolt serving as a fixing support whose one end is fixed to the filter case while being inserted through the core, a threaded groove provided on the other end of the bolt, and a bolt screwed into the threaded groove. fastening means consisting of a nut and a spring between the nut and the lower end surface of the hollow shaft of the frame member, and the other cylinder of the filter cover for transmitting the fastening pressing force of the fastening means to the filter cover. It consists of a plurality of spokes integrally molded on the end face and a pressing force transmission member having a bolt insertion hole provided at the center thereof, and presses one cylindrical end face of the filter cover against the flange-shaped portion of the frame member. A configuration is adopted in which the frame member is provided with a removable fixing means for press-fitting the frame member to the inner wall surface of the filter case.

[Function] The air filter with the above configuration is assembled by placing the filter in a predetermined position within the filter case and attaching the frame member to the inner wall of the case during manufacturing or when replacing an old filter. The cylindrical filter cover is placed so as to be in contact with the filter cover, and the cylindrical filter cover is fitted onto the filter so that one cylindrical end surface of the cylindrical filter cover is pressed against the entire periphery of the flange-shaped portion of the frame member.

Thereafter, when the filter cover is pressed into contact with the flange-shaped part by the removable fixing means, this flange-shaped part is pressed against the inner wall surface of the filter case with a uniform pressing force over its entire periphery. be done.

When replacing a dirty filter, the filter cover is used repeatedly.

[Example] The specific configuration of the present invention will be described below based on the example shown in the attached drawings.

1 to 4 each show an embodiment of the present invention. FIG. 1 is a side sectional view depicting the overall structure of the air filter.

A filter case 1 made of metal or synthetic resin has a flat cylindrical shape as a whole, and an inlet 2 for purified air is provided on the outer peripheral surface in a tangential direction to the cylinder wall surface, and an inlet 2 for purified air is provided on the top surface. An air outlet 3 is provided. The bottom of the filter case 1 is in an open state, and a case bottom plate 11 is separately manufactured.
are removably assembled with a gasket 12 in between. The case bottom plate 11 has a conical shape bulging downward, and is provided with a group of holes 11a through which coarse dust particles in the air and condensed water can fall.
Reference numeral 13 denotes a dust pan, which is stacked on the bottom side of the case bottom plate 11, and has a removable fastening fitting 1.
4 is secured to a flange-shaped portion formed at the lower bottom periphery of the filter case 1 together with the case bottom plate 11. 15 is a handle for engaging and disengaging the metal fitting 14. The dust pan 13 is provided with a drain hole 17 and a drain valve 16 for draining condensed water.

In this embodiment, the filter 4 has a cylindrical shape with concentric folds formed around the cylindrical axis to increase the surface area, and is of an axial flow type in which the air to be purified flows in the direction of the cylindrical axis. A frame member 5 is used to press the filter 4 against the inner wall surface of the filter case 1 so as to cover the air outlet 3.
When creating by synthetic resin injection molding method,
By pre-installing this filter 4 into a mold, a filter unit in which the filter members 5 are integrally assembled is constructed.

The frame member 5 of the filter 4 has an axis of a main body portion 5a as a torus having a diameter somewhat larger than the outer diameter of the filter 4 and a downward (in FIG. 1) substantially U-shaped cross-sectional shape. A hollow shaft portion 5b is positioned at the core, and this hollow shaft portion 5b and the annular main body portion 5
A is combined with a plurality of spokes 5c. The spokes 5c are hollow shaft portions 5
They are formed on both the upper and lower ends of b, and the upper spoke has a group of downward comb tooth-shaped protrusions 5d.
Also, the lower spoke has a group of similar upward protrusions 5d.
is integrally molded. The filter 4 has its pleats sandwiched between the plurality of sets of comb tooth-like protrusions 5d provided vertically opposite each other, thereby forming a frame member with the above-mentioned complex but integrated structure. It is strongly combined with 5.

Reference numeral 10 denotes a cylindrical filter cover made of metal or synthetic resin, and a bearing-shaped bolt insertion portion 10a supported by a plurality of spokes 10b is integrally formed on one end surface of the filter cover.

Reference numeral 6 denotes a bolt that is inserted through the axis of each of the cylindrical filter 4 and the cylindrical filter cover 10 and serves as a support for fixing the two. At the lower end of this bolt 6, a wing nut 8 is screwed into a threaded groove provided in a portion that protrudes downward through the hole of the bolt insertion portion 10a of the filter cover 10, and the wing nut 8 and the frame member 5 An extension spring 18 is interposed between the lower end surface of the hollow shaft portion 5b and serves as a fastening means.

The upper end side of the bolt 6 is fixed to the filter case 1 by being inserted into the bolt hole 1a at the top of the filter case 1, and the bolt 6 is used to transmit the fastening pressure applied from the wing nut 8 to the filter cover 10. It is a pressing force transmitting member, and constitutes a detachable fixing means together with the fastening means.

By tightening the wing nut 8 in the assembled state shown in FIG.
It is fixed to the inner wall surface of the top part by pressure. At this time, the U-shaped cross-sectional shape of the main body portion 5a of the frame member 5 is elastically deformed in response to the pressing force, which greatly prevents sealing failure at the pressure-welded portion due to vibration force or the like. be done.

Reference numeral 7 denotes a ring-shaped gasket for press-contacting the frame member 5 of the filter to the top surface of the inner wall of the filter case 1 while maintaining an airtight state.In order to cope with the phenomenon of the gasket 7 becoming flattened over time, an extension spring 18 is interposed. I'm letting you do it. 21 and 22 are brackets for mounting the filter case, and 23 is an outlet pipe for purified air.

2 and 3 show a method of attaching a bearing member made of a pair of plate pieces 25 and 26 pasted together to the air outlet 1 as means for fixing the upper end of the fixing bolt 6. 27 is an intake pipe.

5 and 6 are explanatory diagrams illustrating a method of manufacturing the filter 4. FIG. First, a sheet-like filter material 4A cut into fan shapes as shown in FIG. 5 is prepared. Next, concentric fold groups m-m', n-n', . Thereafter, the filter material 4A is compressed in the radial direction of the fan shape to form pleats as shown in FIG. By adding, a cylindrical filter with concentric circular shapes as shown in the figure is formed. Then, both radial edge lines 1-v and 1' of the fan-shaped filter material 4A are brought to a position where they collide with each other.
-v' is bonded together with adhesive 30 to fix the filter shape. This filter 4
is given a truncated conical shape to match the conical shape of the filter case bottom plate 11. Further, although the filter 4 shown in the figure has folds of pleats forming acute angles, it can easily be formed into a rounded bent shape as shown in FIG.

Overacting of the air filter shown in the above embodiment diagrams is carried out as follows. In the case of an air filter for an internal combustion engine, the air to be purified is drawn into the filter case 1 from the air inlet 2 in a tangential direction to the cylindrical wall surface of the case due to the suction negative pressure generated in the cylinder. An annular gap a between the inner peripheral wall of the case 1 and the outer peripheral wall of the filter cover 10
It descends while turning inside, and reaches the bottom space b, which has a conical shape with a narrowed bottom and constitutes a cyclone, and the turning speed is increased. Relatively coarse dust particles having a large mass collide with the case bottom plate 11 under the influence of centrifugal force and are separated from the air flow. Since there is a pressure difference between the front and back surfaces of the superlayer of the filter 4, the air that gathers in the bottom space b as a pre-filter passes through the superlayer against the ventilation resistance of the superlayer and is purified. Fine dust particles that escape to the air outlet 3 are captured by the filter 4. An upward conical shape 11b is provided at the center of the case bottom plate 11, contributing to the formation of smoother swirling airflow.

Next, the structural features of the above air filter will be explained in comparison with the conventional air filter shown in FIGS. 7 and 8.

As mentioned above, conventional air filters use a disk-shaped frame member 1 as a method of compressing the frame member of the filter against the inner wall surface of the filter in an airtight manner.
05, the air filter 4 according to the present invention has a cylindrical filter cover 10 with one end side circumferential edge facing the outer circumferential side. With the flange-shaped peripheral edge portion 10c bent in a flange shape in contact with the flange-shaped portion constituting the main body portion 5a of the frame member 5 of the filter 4, a butterfly is attached to the other end side of the filter cover 10. Since the configuration is such that the pressing force generated when the nut 8 is tightened is applied, both air filters use a method in which the frame member of the filter is pressed against the inner wall surface of the case by the tightening force of the thumbscrew. In the former case, if the axis of the assembly bolt 106 to which the wing nut is screwed is placed in a position that is even slightly eccentric with respect to the axis of the disc-shaped frame member 105, the contact point between the frame member and the case will be affected. frame member 105 as
It becomes impossible to apply a uniform pressure force to the entire periphery, and the reliability of the airtight seal is lost. However, the latter according to the present invention has a support structure that makes it easy to keep the fixing bolt 6 in the correct coaxial position with respect to the axis of the frame member 5, and also,
The pressure-receiving surface to which the fastening pressing force of the wing nut 8 is applied is
The former is the cylindrical end surface of the cylindrical member 109, which has an extremely small diameter, whereas the latter is the cylindrical end surface of the filter cover 10, which has a much larger diameter, so that the filter replacement and assembly operations are quite careless. Even when the tightening force is applied to the brim-like peripheral edge 10c of the filter cover 10 with a sufficiently uniform distribution, the frame member 5 of the filter 4 is secured to the filter case while maintaining high airtightness. It is fixed at 1. Also, the former disc-shaped frame member 10
5, due to the continuous pressing force being applied to the center part, the center part becomes sag over time due to the creep phenomenon of the board material, and the frame member 10
There is a tendency for the compressive force on the peripheral edge of the frame member 5 to weaken and the airtight sealing performance to deteriorate, but such a phenomenon cannot occur with the frame member 5 of the present invention.

In the above embodiment, fixing bolts and wing nuts are used as means for fixing the frame member of the filter to the inner wall surface of the case, but the design of this fixing means can be changed in various ways. For example, the design of the fixing means can be changed in various ways. A method such as interposing a spring material between the bottom plate 11 and the bottom plate 11 may be used. Furthermore, the shapes of the filter 4 and the filter case 1 can be modified in various ways without departing from the scope of the technical idea of the present invention.

[Effects of the invention] The air filter according to the invention having the above-mentioned configuration does not require special attention when assembling the filter during its manufacture or when replacing the filter as a consumable item. The frame member can be easily attached to the inner wall surface of the filter case while maintaining the required airtight seal.

In addition, the filter with the frame member assembled and the filter cover are separate pieces, so unlike conventional air filters, when replacing a dirty filter,
There is no need to discard the filter cover at the same time.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing one embodiment. FIGS. 2 and 3 are a side sectional view and a top view, respectively, showing another embodiment of the present invention in which the structure of the filter case is somewhat different. FIG. 4 is a perspective view of the filter cover. FIGS. 5 and 6 are explanatory diagrams of an example of a method for manufacturing a filter. 7 and 8 are a side sectional view of a conventional air filter and a side sectional view of a built-in filter cover. In the figure, 1... Filter case, 2, 3... Air inlet and outlet, 4... Filter, 5... Frame member, 6... Fixing bolt, 7... Gasket,
8... Butterfly nut, 10... Filter cover, 18
...Spring, 6+8+18...Fixing means.

Claims (1)

[Claims for Utility Model Registration] A filter case provided with an air inlet and an air outlet, and a frame member disposed within the filter case to cover the outlet and having an outwardly facing flange-shaped portion on a cylindrical end surface of the outlet. The assembled axial flow type cylindrical filter, the cylindrical filter cover for protecting the outer circumferential surface of the filter, and the one end side of the filter and the filter cover are inserted into the core portions of the filter and the filter cover. A bolt as a fixing support fixed to the filter case, a threaded groove provided on the other end of the bolt, a nut screwed into the threaded groove, and the nut and the lower end surface of the hollow shaft of the frame member. a fastening means consisting of a spring between the fastening means, a plurality of spokes integrally molded on the other cylindrical end surface of the filter cover, and a plurality of spokes provided at the center thereof, for transmitting the fastening pressing force of the fastening means to the filter cover. a pressing force transmission member having a bolt insertion hole, for pressing one cylindrical end surface of the filter cover against the flange-shaped portion of the frame member and pressing the frame member against the inner wall surface of the filter case. and a removable fixing means.