JP2000061234A - Filter element provided with prefilter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter element having a prefilter reduced in cost by simplifying a means mounting the prefilter to a main filter and excellent in external appearance since the component of the mounting means is not exposed on the surface of the perfilter. SOLUTION: The main filter 6 is formed by bending a filter material 2 such as filter paper and nonwoven fabric in a form like bellows and fixing a resin made substrate frame 3, an end surface frame 4 and an intermediate frame 5 projecting to an upper surface of the filter material 2 (the end surface frame 4 and the intermediate frame 5 project by about 2-3 mm upward from the upper surface of the filter material 2), and the prefilter 7 is mounted on the upstream side from the main filter 6, and a part of the end surface frame 4 or the intermediate frame 5 and the prefilter 7 are molten and solidified to fix both together giving an ultrasonic wave at an upper part corresponding to a position provided with the end surface frame 4 or the intermediate frame 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter element with a prefilter having a prefilter arranged upstream of a main filter.

[0002]

2. Description of the Related Art An element with a prefilter of this type is known from the fact that it is disclosed in Japanese Patent Laid-Open No. 10-85539. The element with a prefilter disclosed in this publication has a folded main filter, a prefilter made of a non-woven fabric having a large porosity disposed upstream of the main filter, and a folded shape of the main filter. The frame is made of resin and is provided with an engaging projection for holding the prefilter, which is held on the end surface facing the prefilter and projects toward the upstream side.

The locking projections are formed on the shaft portion penetrating the prefilter and on the tip end side of the shaft portion, are located on the upstream side of the prefilter, and have a large tip diameter portion for fixing the prefilter. Or a material having a melting point higher than the melting point of the resin that constitutes the resin frame, the tip diameter of the locking projection is larger than the outer diameter of the large portion, and the outer diameter of the shaft portion of the locking projection is larger than the outer diameter. An annular member having a large inner diameter is arranged between the upstream side surface of the prefilter and the large tip diameter portion, has a tip bending presser portion for fixing the prefilter, or has an umbrella-shaped holding portion for fixing the prefilter. Or a resin frame having an engaging hole for mounting the prefilter on the end surface facing the prefilter.

Further, the prefilter has a connecting convex portion in which a portion of the resin frame facing the engaging hole is hardened in a convex shape, and the connecting convex portion is detachably inserted into the engaging hole. Then, the prefilter is fixed to the resin frame.

[0005]

However, in reality, there were technical problems described below. That is, in the above-described conventional filter element with a pre-filter, the means for attaching the pre-filter to the main filter is complicated, the parts cost is high, and the assembly takes time and the cost is high. In addition, the parts of the attachment means are exposed on the surface of the prefilter, which impairs the aesthetic appearance.

The present invention solves the above problems and simplifies the means for attaching the pre-filter to the main filter to reduce the cost, and the parts of the attaching means are not exposed on the surface of the pre-filter. It is an object of the present invention to provide a filter element with a pre-filter which will have the above aesthetic appearance.

[0007]

(1) In order to achieve the above object, claim 1 of the present invention is characterized in that a prefilter made of a nonwoven fabric having a large porosity is arranged upstream of the main filter, and the main filter is provided. Is a resin-made substrate frame that holds the filter material folded in a bellows, and the end face frame and the intermediate frame are projected to at least the upper surface of the filter medium, and the end face frame or the intermediate frame and the pre-filter are fixed by ultrasonic welding. It is characterized by

According to the above structure, since the end frame or the intermediate frame and the pre-filter are fixed by ultrasonic welding, the means for attaching the pre-filter to the main filter is simplified and the cost is reduced, and the surface of the pre-filter is attached. It was possible to provide a filter element with a pre-filter having an aesthetic appearance because the parts of the attachment means are not exposed.

(2) In order to achieve the above object, a second aspect of the present invention is the element with a prefilter according to the first aspect, wherein a projecting column is provided above the end frame or the intermediate frame, and the projecting column. Is provided at a lower portion of the pre-filter up to the height, and the projecting pillar is inserted into the lower cutting portion of the pre-filter, and the projecting pillar and the pre-filter are fixed by ultrasonic welding.

According to the above construction, even when the thickness of the pre-filter is large, a notch is formed in the lower part of the pre-filter up to the height of the projecting column, and the projecting column is inserted into the notch in the lower part of the pre-filter. Since the projecting column and the prefilter are fixed by ultrasonic welding, the prefilter can be easily attached, and it is possible to provide a filter element with a prefilter that prevents deformation of the prefilter due to the attachment of the prefilter.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the invention described in claims 1 and 2 will be described below in detail with reference to the drawings.

=== Embodiment 1 === As shown in FIG. 2, the filter element 1 with a pre-filter shown in FIG.
Is folded into a bellows and the substrate frame 3 made of resin and the end face frame 4 protruding to the upper surface of the filter medium 2 and the intermediate frame 5 are fixed to each other to form the main filter 6 (the end face frame 4 and the intermediate frame 5 are the filter medium 2). It is desirable that it protrudes from the upper surface by about 2 to 3 mm to the upper side in the sense of taking a melting allowance, but the present invention includes those without such an upper protrusion),
On the upstream side of the main filter 6, a prefilter 7 made of fibers such as polyester, nylon, acrylic, rayon, and cotton, having a basis weight of 100 to 600 g / m ² and a porosity of 95 to 99% is placed, The horn 8 of the ultrasonic welding machine is placed on the prefilter 7 corresponding to the position where the end face frame 4 or the intermediate frame 5 is provided, and ultrasonic waves are applied to the end face frame 4 or the intermediate frame 5 and the prefilter. A part of 7 is melted and solidified, whereby both are fixed and manufactured.

In the above structure, the horn 8 of the ultrasonic welding machine is placed on the upper portion of the pre-filter 7 corresponding to the position where the end face frame 4 or the intermediate frame 5 is provided, and ultrasonic waves are applied to the end face frame 4 Alternatively, the intermediate frame 5 and a part of the pre-filter 7 are melted and solidified to be fixed to each other, so that the number of parts is small and the cost is reduced, and the parts of the attaching means are not exposed on the surface of the pre-filter 7, so that the appearance is aesthetically pleasing. Will be equipped with.
Further, when the end face frame 4 and the intermediate frame 5 having the protruding portions 4a and 5a protruding upward from the upper surface by about 2 to 3 mm are used, a space is provided between the upper surface of the main filter 6 and the lower surface of the pre-filter 7. Main filter 6
The entire surface of can be used more effectively.

=== Embodiment 2 === The filter element 1 with a pre-filter shown in FIG.
The filter medium 2 is bellows-folded and fixed to the resin-made substrate frame 3, the end face frame 4 protruding to the upper surface of the filter medium 2 and the intermediate frame 5 to form the main filter 6, and the end face frame 4
Alternatively, at least four positions of the intermediate frame 5 and the projecting pillar 9 as shown in FIG. 4 and the pre-filter 7 as shown in FIG.
A notch 10 provided at the same height as the protrusion 9 at the bottom of the pre-filter 7, and the protrusion 9 is provided at the notch 10 at the bottom of the prefilter 7.
, The pre-filter 7 in the notch 10 is compressed, and the horn 8 of the ultrasonic welding machine is placed on the pre-filter 7 at the position of the projecting column 9 to apply ultrasonic waves.
When a part of the prefilter 7 is melted and solidified, both are fixed and the filter element 1 with the prefilter is formed.

According to the above construction, even when the thickness of the pre-filter 7 is large, the notch 10 is provided in the lower portion of the pre-filter 7 to the same height as that of the projecting pillar 9 so that the projecting pillar 9 is provided in the lower portion of the pre-filter 7. The pre-filter 7 is inserted into the notch 10, the pre-filter 7 in the notch 10 is compressed, and the two are fixed by ultrasonic welding. Therefore, the pre-filter can be easily attached,
It is possible to prevent the deformation of the prefilter due to the mounting of the prefilter, and the parts of the mounting means are not exposed on the surface of the prefilter 7, so that the appearance is provided.

In the second embodiment, the one without the upper protrusion is shown, but it may be replaced with the one with the upper protrusion as in the first embodiment.

[0017]

According to the above structure, as described above,
The filter element with a pre-filter according to claim 1 is fixed to an end face frame and an intermediate frame having an end face frame and an intermediate frame in which a filter medium is projected upward (preferably 2 to 3 mm), and is fixed as a main filter upstream of the main filter. When the pre-filter is placed on the side, the horn of the ultrasonic welding machine is placed on top of the pre-filter at the position of the end face frame or the intermediate frame, and ultrasonic waves are applied to the end face frame or the intermediate frame and a part of the pre filter. As the two melt and solidify, they stick together,
Since the number of parts is small and the cost is reduced, and the parts of the attachment means are not exposed on the surface of the prefilter, the appearance is provided.

In the filter element with a prefilter according to a second aspect of the present invention, even if the thickness of the prefilter is large, a notch is provided in the lower part of the prefilter to the same height as the projecting column, and the projecting column is provided in the notch in the lower part of the prefilter. Insert and compress the pre-filter in the notch, and place the horn of the ultrasonic welding machine on the pre-filter at the position of the projecting column to give ultrasonic waves. The parts are melted and solidified to fix them, so that the pre-filter can be easily installed, the deformation of the pre-filter due to the installation of the pre-filter can be prevented, and the parts of the installation means are exposed on the surface of the pre-filter. Since it does not, it has an aesthetic appearance.

[Brief description of drawings]

FIG. 1 is a perspective view showing a filter element with a prefilter according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a main filter of the filter element with the prefilter.

FIG. 3 is a perspective view showing a filter element with a prefilter according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view showing an intermediate frame portion of the filter element with the prefilter.

FIG. 5 is a cross-sectional view showing a cut portion of a pre-filter in the filter element with the pre-filter.

[Explanation of symbols]

2 Filter material 3 PCB frame 4 end face frame 5 middle frame 6 Main filter 7 pre-filter 8 horns 9 Projection 10 notch

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 4D019 AA01 BA13 BB02 BB03 BB05                       BB10 BD01 CA02 CB01 CB03                       CB06                 4D058 JA12 JA14 JB14 JB25 JB26                       JB39 KA01 KA13 KA23 KA25

Claims (2)

[Claims] 1. A pre-filter made of non-woven fabric having a large porosity is arranged on the upstream side of the main filter, and the main filter has a resin-made substrate frame holding a bellows-folded filter medium and an end face frame and an intermediate frame. An element with a prefilter, characterized in that it is made to project at least to the upper surface of a filter medium, and the end face frame or intermediate frame and the prefilter are fixed by ultrasonic welding. 2. The element with a prefilter according to claim 1, wherein a projecting column is provided on an upper portion of the end face frame or the intermediate frame, and a notch is provided on a lower portion of the prefilter up to the height of the projecting column, and the projecting column is provided. A filter element with a pre-filter, characterized in that the protrusion and the pre-filter are fixed to each other by ultrasonic welding by inserting the pre-filter into a notch in the lower part of the pre-filter.