JPS63280847A - Air cleaner cap - Google Patents

Abstract

PURPOSE:To reduce noise and improve productivity by forming a cap by superposing two thin steel plates having different characteristic frequency and forming a flange part in which an outside thin steel plate is constricted to an inside thin steel plate side on the peripheral edge of the cap. CONSTITUTION:The main part of a cap 1 is formed from two thin steel plates 2 and 3, and an uneven part 4 is formed in the body part. A flange part 5 is formed on the peripheral edge of the cap 1. The flange part 5 is formed from the superposed part 5a of two thin steel plates 2 and 3, constricted part 5c where an outside thin steel plate is constriction-attached on the underside of an inside thin steel plate 3a, and an outside steel plate part 5b extending outside for the constricted part 5c. In this case, the resonance frequency is deflected by making different each thickness of two thin steel plates 2 and 3, and the intake pulsation sound can be attenuated. Therefore, the vibration of the cap 1 accompanied with the vibration of the engine can be reduced, and the intrusion of processing liquid into between two thin steel plates 2 and 3 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an air cleaner cap, and more particularly to an air cleaner cap used in an air cleaner for an internal combustion engine.

[Conventional technology]

A typical air cleaner cap used in a conventional air cleaner for an internal combustion engine is shown in FIG. 9. That is, an annular air cleaner element 91 is built-in and fixed within the air cleaner main body 90. The air cleaner main body 90 has a cap 92
The edge 92a of the cap 92 is in contact with the upper end 94 of the air cleaner main body 90 via the gasket 93. The air cleaner main body 90 and the cap 92 are fixed by a buckle 95 provided on the side surface of the main body 90. A bracket 96 is provided at the center of the main body 90, and a fixing bolt 97 is passed through the bracket 96 so as to project upward. By tightening this bolt 97 with a nut 98, the center portion of the cap 92 is fixed to the bracket 96. A center bolt through hole 99 is provided at the center of the cap 92, and the bolt passes through the nine through holes.

In addition, the air cleaner cap was formed from two parts: a thin steel plate and a fiber layer attached to the inner surface of the thin steel plate.
There is one described in Japanese Patent No. 9-7025. In this air cleaner cap, after the cap is molded, a fiber layer made by impregnating a group of fibers with a rubber-like elastic material is attached to the inner surface of the cap using an adhesive. .

[Problem that the invention seeks to solve]

In the air cleaner shown in FIG. 9, the cap 92 is formed from a single steel plate, so engine vibrations are transmitted to the cap 92, causing the cap 92 to vibrate and cause large noise. .

In addition, in the air cleaner cap disclosed in Japanese Patent Publication No. 59-7025, which takes advantage of the sound-absorbing effect of the fiber layer, a rubber-like elastic material is applied to the dispersed fibers so as to stand upright against the inner surface of the cap. The problem is that a fiber layer impregnated with a fibrous material must be attached to the inner surface of the cap, and the manufacturing process is complicated and unsuitable for mass production.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an air cleaner cap with low vibration, that is, low noise and excellent mass productivity.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides an air cleaner body which closes the upper surface of a cylindrical body containing a ring-shaped air cleaner element, and the air cleaner cap is made by overlapping two thin steel plates. The outer thin steel plate extends longer than the inner thin steel plate, and the outer thin steel plate extends longer than the inner thin steel plate. Manufacture of an air cleaner cap characterized by constricting inwardly at the tip of an inner thin steel plate and tightly contacting the tip, and an air cleaner cap that closes the upper surface of a cylindrical body containing a ring-shaped air cleaner element. In this method, two steel plates with different diameters are punched out from a thin steel sheet material, these two steel plates are overlapped and the uneven shape of the main part of the cap is press-formed with a mold, and then the two pieces are integrated. The peripheral flange part of the steel plate is arranged so that the steel plate with the smaller diameter is located on the male mold surface side, and the male mold forming surface having a tapered surface that widens toward the end on the peripheral surface and the inside of the male mold parallel to the direction of movement. This method of manufacturing an air cleaner cap is characterized in that the peripheral flange portion is narrowed between the peripheral surfaces so that the outer thin steel plate is constricted at the lower end portion of the inner thin steel plate.

[For production]

According to the present invention, the air cleaner cap is made up of two thin steel plates with different natural frequencies, so vibrations from the engine are transmitted to the air cleaner, and the frequency changes when the vibrations are transmitted. This results in damping of vibrations, i.e., reduction of noise.(The outer thin steel plate extends longer than the inner thin steel plate in the peripheral flange of the cap, and the outer thin steel plate or the inner thin steel plate is connected inward at the tip of the outer thin steel plate. Because it is constricted and tightly attached to the tip, it prevents liquid from entering between the two steel plates during alkaline degreasing at the peripheral flange, or from surface treatment liquid entering between the two steel plates when painting the cap. Completely prevented.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 8.

In FIG. 1, the air cleaner cap 1 of the present invention is made up of two thin steel plates 2.3, for example, the outer steel plate 2 is 0.3.
The inner steel plate 3 is made of a 0.4 inch thin steel plate. An uneven shape 4 is formed on the main body portion of the cap 1. Further, a flange portion 5 is formed on the periphery of the cap 1, and this flange portion 5 has an outer thin steel plate constricted between a portion 5a where two thin steel plates overlap and the lower end of the inner thin steel plate 3a, and enters inside and is tightly attached. It consists of a constricted portion 5c and an outer steel plate portion 5b extending outward from the constricted portion 5c. Here, since the outer steel plate 2 and the inner steel plate 3 have different thicknesses, the outer steel plate 2
The resonant frequency of the inner steel plate 3 is shifted, and the intake pulsation noise is attenuated. 'J, Corrosion resistance can be improved by making the outer steel plate thicker than the inner steel plate.

Further, a center bolt through hole 15 is formed in the center of the main body portion of the cap 1, and a tight seal portion 16 is formed around the periphery of this bolt through hole 15. Generally, air cleaner caps must be painted, but pretreatment for this includes alkaline degreasing, water washing, drying, chemical conversion treatment, water washing, and drying steps, followed by electrostatic painting.

If water or surface treatment liquid enters the two steel plates during these coating treatments, the liquid may evaporate when the soot dries and blow out from the overlapping area, making painting impossible. However, if a close contact portion is formed at the tip of the inner steel plate 3a of the flange portion and the periphery of the center bolt through hole as in the present invention, it is effective to prevent water and surface treatment liquid from entering between the drawing boards during painting. is prevented.

Further, since the inner steel plate 3a of the flange portion 5 is supported from below by the constricted portion 5C of the outer steel plate of the flange portion 5, separation of the drawing board is completely prevented. As shown in FIG. 2, an outer steel plate portion 5b extending downward from the constricted portion 5C is located inside an extension line 1 along the outer surface of the portion 5a where the drawing plates of the flange portion overlap. Therefore, it is effectively prevented that the area around the air cleaner cap becomes a hindrance to the installation of various parts above the engine part of the automobile.

FIG. 8 shows the experimental results regarding the vibration damping effect, that is, the noise prevention effect. That is, in Fig. 8, the horizontal axis shows the engine speed, and the vertical axis shows the noise level. Here, the conventional cap is made of a single steel plate with a thickness of 1 mm. The noise of the cap 1 of the present invention, in which the inner steel plate is 0.4 mm and the outer steel plate is 0.6 mm, is shown by the solid line A, and the noise of the conventional cap is shown by the solid line A. Indicated by dotted line B. According to this graph, the rotation speed is 30
The noise effect of both caps is almost the same between 00 rpll and 4000 ru, but at other frequencies, the vibration damping effect of the cap of the present invention is significantly better than that of the conventional cap. I'm angry.

Next, FIGS. 3 to 7 show the cap forming method of the present invention.
This will be explained with reference to the figures.

First, two steel plates, namely a steel plate 2 with a large diameter and a steel plate 3 with a small diameter, are punched and formed from their respective thin plates, and are placed between an upper mold 6 and a lower mold 7 as shown in FIG. The cap 1 is placed on top of itself, and the uneven shape of the circumferential portion of the cap 1 is formed by the protruding portion 6a of the upper mold 6 and the corresponding recessed portion 7a of the lower mold 7. The cap material is placed on the male mold 10 with the inner steel plate 3 having a smaller diameter positioned on the male mold 10 side, as shown in FIG. At this time, the surrounding portion of the overlapping steel plates 2.3 slightly protrudes from the periphery of the male mold 10 in the lateral direction. In addition, a male mold 9 is provided opposite to the male mold 10.
An inner molding surface 9a of the male die 9 extends parallel to the direction of movement thereof. The molding surface of the male mold 10 facing the molding surface 9a is a tapered surface 10a that widens toward the end.

This tapered surface 10a is formed to have a predetermined length as shown in FIG. In this state, as shown in FIG. 5, the male mold is placed over the male mold and the flange portion 5 of the cap 1
When the tapered surface 10a of the male die and the inner circumferential forming surface 9a of the male die are bent to form a The tip 3b of the inner steel plate 3a and the inner circumferential surface of the constriction part 5c of the outer steel plate tightly adhere to each other. Also, the outer steel plate part 5b extending downward from the constriction part 5c has an outer side due to the plasticity of the steel plate. As shown in Fig. 2, the outer steel plate portion 5b extends slightly outward. If the flange portion is drawn using the male mold 1o having the tapered surface 10a and the male mold 9 having the forming surface 9a, the tip 3b of the inner 1111 steel plate and the constricted portion 5c of the outer steel plate will be tightly adhered to each other during painting. Water and surface treatment liquid will not enter between the art boards.

Next, as shown in FIG.
Then, as shown in FIG. 7, the periphery of the through hole 15 is seam welded or spot welded using, for example, a ring-shaped t-pole 13 to form the seal portion 16. In this way, water and surface treatment liquid are completely prevented from entering the inner through hole 15 and the tip of the inner steel plate 3a of the flange portion. Although the outer steel plate 2 and the inner steel plate 3 are completely adhered to each other at the inner and outer edges through the above-mentioned process, there is a slight gap between the pattern plates during press forming in the middle area excluding the inner and outer edges. Due to the lick that is created, the art board does not vibrate as a unit, and a vibration damping effect can be expected.

〔Effect of the invention〕

As explained above, the present invention has two thin steel plates stacked on top of each other, and a center bolt through hole and an inner ll1f of the flange portion.
Since the tip of the JA plate is completely brought into contact with the inner surface of the outer steel plate, it is effectively prevented from causing large vibrations of the cap due to engine vibration, and the two thin steel plates are completely separated. is prevented. Further, it is effectively prevented that water or surface treatment liquid enters between the drawing boards during painting, and the liquid that enters into the space evaporates due to drying during the painting process, resulting in incomplete painting. Furthermore, the air crevice cap of the present invention has a simple structure and can suppress vibrations.
Especially suitable for mass production.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal section of the air cleaner cap of the present invention, FIG. 2 is an enlarged view of the flange portion of the air cleaner cap,
Fig. 3 is an explanatory diagram of the molding state of the uneven shape of the peripheral portion of the cap, Fig. 4 is an explanatory diagram of the molding state of the flange part of the cap,
Fig. 5 is an explanatory diagram of the state when the male mold and the male mold are combined when forming the flange portion of the cap, Fig. 6 is an explanatory diagram of the state when forming the center bolt through hole, and Fig. 7 is an explanatory diagram of the state when the center bolt through hole is formed. FIG. 8 is a graph comparing the vibration and damping effects of the present invention and a conventional product, and FIG. 9 is a longitudinal sectional view of a conventional air cleaner. DESCRIPTION OF SYMBOLS 1... Cap, 2... Outer steel plate, 3... Inner steel plate, 5c... Constriction part, 9... Male mold, 10...
Male type, 15...Bolt through hole, 16...Tight seal part. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 1o00 2000 3000 4000 50
00. 6000 70oo Ne (rpm) Fig. 8

Claims (1)

[Claims] 1. In an air cleaner cap that closes the upper surface of a cylindrical body containing a ring-shaped air cleaner element, the air cleaner cap is made of two thin steel plates stacked one on top of the other, and its periphery is The flange part is bent to fit along the side wall of the cylindrical body, and in this flange part, the outer thin steel plate extends longer than the inner thin steel plate, and the outer thin steel plate is attached to the tip of the inner thin steel plate. An air cleaner cap that is constricted inward and tightly attached to its tip. 2. The air cleaner cap has a center bolt through hole at its center, and the periphery of the center bolt through hole is tightly sealed.
Air cleaner cap as described in section. 3. The outer steel plate of the flange portion extends from the constricted portion at the tip of the inner thin steel plate, from the extension line of the outer peripheral surface of the outer steel plate of the overlapped portion of the two steel plates of the flange portion of the air cleaner cap. 2. The air cleaner cap according to claim 1, wherein the portion made of the steel plate does not protrude outward in the radial direction of the cap. 4. In a method for manufacturing an air cleaner cap that closes the top surface of a cylindrical body containing a ring-shaped air cleaner element, two steel plates with different diameters are prepared by punching out from a thin steel sheet material, and these two steel plates are overlapped. At the same time, the uneven shape of the main part of the cap is press-formed using a mold, and then the peripheral flange portions of the two integrated steel plates are arranged so that the steel plate with the smaller diameter is located on the male mold side. The outer thin steel plate is constricted at the lower end portion of the inner thin steel plate by squeezing the peripheral flange portion between a male molding surface having a tapered surface that widens toward the end on the peripheral side and an inner molding surface of the male mold parallel to the moving direction. A method of manufacturing an air cleaner cap characterized by: 5. Forming a center bolt through hole in the center of the air cleaner cap after forming the peripheral flange portion;
5. The method of manufacturing an air cleaner cap according to claim 4, wherein the periphery of the cap is brought into close contact with the periphery thereof.