RU2597751C1 - Flaps with sound insulation and preparation method thereof - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: group of inventions relates to automotive industry, in particular, to moulded flap with property of sound insulation and method of its production. Method of making flap with sound insulation involves fixing one or more sound-absorbing pads made from nonwoven synthetic material in specified places on inner side of a matrix. Further, method includes applying on matrix a heated sheet of polymer material and fixing its edges on matrix. Then vacuum is created between matrix and sheet, followed by cooling flap with moulding thereto sound-absorbing pads and final treatment thereof.

EFFECT: technical result of invention consists in improvement of reliability of sound-absorbing pads with a flap.

7 cl, 2 dwg, 4 tbl

Description

The group of inventions relates to transport engineering, in particular to the design of a noise-insulating wing liner and a method for manufacturing noise-insulating molded wing liners intended for body wings, mainly a passenger car.

Known liner designed to be placed in the wheel housing of a car body, having noise insulation properties due to fixing at least part of its outer surface of a layer of sound-absorbing polymeric porous material such as polyurethane foam (RU 51945, class B60R 27/00; published on 03/10/2006 )

Said sound-absorbing material can only be applied to the liner with glue.

Also known is a multilayer noise-reducing gasket for a vehicle body panel containing a layer of porous sound-absorbing material, on the mounting side of which is applied an adhesive layer covered by a protective paper layer. Before directly installing the gasket on the corresponding body panel, the protective paper layer is removed and, by applying the gasket with an adhesive layer of the panel to the degreased surface of the panel, fix it on the steel body panel in the right place, pressing it manually or using a magnetic roller (RU 2188772, class B60R 13/08 ; published September 10, 2002).

A disadvantage of the known solutions lies in the unreliability of adhesion fastening of sound-absorbing elements to car body parts, since not every such element can be fixed on a complex spatial surface without tearing it off from this part during operation of the car, the parts of which are significantly affected by tensile or compressive forces.

The objective of the invention is to improve the operational, including noise, properties of the car body.

The aforementioned task is provided with a technical result aimed at improving the reliability of the connection of the noise absorbing pads with the wing liner.

The technical result is achieved in the invention using the following combination of features.

A method of manufacturing a soundproofed wing liner is that one or more noise absorbing pads of non-woven synthetic material are fixed in predetermined locations on the inside of the matrix. After that, a heated sheet of polymer material is applied to the matrix and its edges are fixed on the matrix. Then a vacuum is created between the matrix and the sheet, after which the wing liner with the sound-absorbing plates molded to it is cooled and it is finished.

Fixing the pads on the matrix is carried out using textile fasteners such as Velcro.

The final processing of the wing liner includes filing and formation of holes in the specified places by drilling and / or punching.

As in the aforementioned analogue, the liner for the car body has a flexible body, made taking into account the geometry of the body wing and the wheel arch of the car.

In contrast to the aforementioned analogue, at least on the part of the outer side of the wing liner body facing the wheel housing of the car body, a soundproof layer made of non-woven synthetic material is fixed during molding of the wing wheel.

The edge of the front wall of the body can be made with bending to the outside with the formation of a protrusion located in the longitudinal direction, made with the possibility of placing on the inner side of the edge of the wing of the car body.

Also, flanges can be formed on the lateral sides of the wing housing, the width of which corresponds to the width of the wheel housing of the car body.

As a noise insulation material, for example, a high-tech non-woven or non-woven composite material made on the basis of polyester fibers with possible thermal bonding of the fibers can be used. This material may consist of one or more layers, the fibers of which are braided or interlaced in the horizontal and / or vertical plane, which creates additional strength, resistance to deformation and effective absorption of sound waves and vibration. This material may have an additional layer or impregnation to enhance the sound insulation effect.

The invention is illustrated by drawings, where in FIG. 1 schematically shows a liner (general view); in FIG. 2 is a section AA in FIG. 1 (together with the car body wing).

Depicted in FIG. 1, the protective liner (locker) has a flexible body 1, the shape of which is as close as possible to the shape of the wing of the car body 2 (Fig. 2). Through-holes 3 are made in the housing of the Locker, which are intended for passage through them of fastening means made, for example, in the form of bolts 4, when mounting the Locker in the wheel housing of the car body.

In FIG. 2 shows an embodiment of a wing liner, on the entire outer side of the casing of which a layer of sound-absorbing material 5 is applied, which protects the passenger compartment from penetration of extraneous sounds and dampens vibration.

The edge 6 of the front wall of the wing liner body (Fig. 1) has an external bent portion forming a longitudinal protrusion 8 (Fig. 2), designed to contact the automobile body section 7 for a more dense, and therefore more reliable connection of this section with Locker without breaking the exterior of the car.

Thus, the longitudinal protrusion 8 provides a double effect, namely, additional soundproofing of the car interior, sealing the interior space between the wing liner and the car body, as well as its anti-corrosion properties.

Flanging 9 (Fig. 1) having a width corresponding to the width of the wheel body niche of the car body is formed on one or both sides of the wing housing of the wheel housing.

The flap flap 9 formed on the lateral sides of the housing is an extension of it and is made in one piece with it. These flanges are designed to be placed along the body of the car and during installation in a wheel niche they go inside the body to the width of this niche, while adhering tightly to the wing and underbody of the car and without requiring additional fastening that would weaken the body.

Flanging is mainly intended for the wing liner to fit snugly against the car body and to ensure its anticorrosion properties and to seal the car body, thereby preventing the entry of foreign substances such as moisture, dirt, etc. into its cavity.

Since the negative impact on the wing liner from the flow of sand and stones, as well as the noise and vibration accompanying this flow during the movement of the car, mainly affects the upper wall of the wing liner, the soundproofing material can not be fixed on the entire outer surface of the wing liner, but only on its top wall.

The liner is made of low pressure polyethylene (HDPE) grade 273-79, which has the necessary technological and physical properties, including lightness and the ability to repel snow and dirt.

As a noise insulation material, for example, a high-tech non-woven or non-woven composite material made on the basis of polyester fibers with possible thermal bonding of the fibers can be used. This material may consist of one or more layers, the fibers of which are braided or interlaced in the horizontal and / or vertical plane, which creates additional strength, resistance to deformation and effective absorption of sound waves and vibration. This material may have an additional layer or impregnation to enhance the sound insulation effect.

The above-mentioned soundproofing material effectively dampens sound and vibration from rubble, sand, gravel, and ice hitting the fender, in addition, the fender housing reliably protects the wheel arch from all of the above mechanical influences and corrosion, and also reliably protects the coating material itself, while maintaining its durability.

As fasteners for the fender liner, plastic dowels, bushings, bolts or pistons, as well as metal screws, nuts and washers, are used.

Noise-isolation fenders are made by negative thermo-vacuum forming of HDPE sheet blanks obtained by flat-gap extrusion and combining it with one or more overlays of synthetic non-woven material such as polyethylene terephthalate (PET). As a result of the implementation of the proposed method of vacuum molding under the action of high temperature, the surface layer of the sound-absorbing material is partially melted and adheres to the surface of the wing liner, which ensures its reliable attachment to the wing liner.

An example of the method

1. Preparation for the formation of soundproofed Lockers

Noise-attenuating pads made of synthetic non-woven material, identified by a sticker (car make) and fender side designation (RR - rear right; FR - front right; RL - rear left; FL - front left) the moulder fixes with textile fasteners (hereinafter referred to as Velcro), carefully pressing the contact points with Velcro to the matrix along the contour. Adhesive-based Velcro are pre-fixed on the matrix in the amount necessary for reliable fixation of the lining. The contour on the inner surface of the matrix, on which the lining of synthetic non-woven material is placed, is preliminarily applied with a marker at the stage of delivery of the matrix.

An identification plate with the name of the model, the designation of the year and month of release, and the product code are fixed on the intended place of the vacuum form.

2. Molding

The workpiece is molded from an extrudate sheet obtained from the HDPE melt and profiled using a flat slot head by extrusion and cut using a cutting device in the form of a special knife located on a movable table in the form of an acceptance conveyor for workpieces of a given size.

The moulder cuts off the blank in the form of an extrudate sheet with the size necessary to overlap the die. Then the hot billet is manually moved to the matrix, evenly spreading over it to avoid defects. Next, the moulder lowers the clamping frame and fixes the workpiece using a mechanical lock, after which it opens the valve of the vacuum system and turns on the fan to cool the product and matrix. In this case, the part of the product’s blank, clamped by the frame, takes the form of the matrix’s inner surface, the HDPE melt partially penetrates into the layers of the fiber structure of the noise-absorbing lining under the action of the force arising when a vacuum is reached in the matrix, and after solidification a mechanically difficult to separate composite is obtained.

After cooling, the vacuum is closed, the product (liner) is removed and laid next to the matrix.

3. Filing

The plastic product processor (sawdust) moves the liner from the molding section to the filing section.

The sawn wing liner is placed on a special table. Sawing is done with a manual jigsaw along the line marked on the outside of the fender (the imprint from the markings on the forming surface of the matrix), smoothly, without pressing the tool to avoid the formation of burrs on the edge of the fender.

After filing, the flake is moved to the crushing area, and the liner is checked for filing quality. If defects are found:

- fixable - make refinement in the form of filing and deburring,

- incorrigible - the liner is moved to the marriage isolator.

Suitable products are moved to the drilling / punching area.

4. Drilling / Punching

Drilling is carried out with an identified tool in the form of a drill of the required diameter at the points marked on the molding surface of the wing liner, comparing it with a template (a template is a finished product with the diameters indicated at the drilled holes) or with marks on the snap (matrix). Drilling is carried out using an electric drill on a special table with a plastic substrate.

Punching is carried out with an identified tool (punch of the required geometry) at the points marked on the molding surface of the wing liner, comparing it with a template (a template is a finished product with the indicated size of the punch), or with marks on a snap (matrix). Punching is carried out by supplying a fender liner under the punch of the punching device, combining the marked punching places with the punch, by pressing the foot pedal or by hitting a hammer on a special punch on a table with a plastic substrate.

After the drilling / punching operation is completed, the liner is checked for drilling / punching quality. If defects are found:

- fixable - make refinement in the form of chip removal;

- incorrigible - the liner is moved to the marriage isolator.

Ready Lockers pass control, they are weighed, labeled, packaged and sent to the finished goods warehouse.

Equipping the wing wheel with a soundproof coating firmly fixed to it will protect the passenger compartment from undesirable effects of sand-rocky-gravel particles of the road surface that come into contact with the wing doors during car operation. Locker docking units reliably protect the car body from the undesirable effects of mud fountains and salt streams, as well as sandblasting and abrasion.

The proposed design of the liner will allow it to be used for a wide range of domestic and imported car brands.

Tests were carried out regarding the effect of linings made of non-woven fabric, fixed by the proposed method on the wing flaps of HDPE, to reduce the internal noise of the car.

The tests were carried out on the dynamometer road of the NAMI test track, which includes two sections of 2 km each, which are distinguished by the quality of the surface (smooth asphalt and broken asphalt). The measurements were carried out alternately, first, with no Toyota Lockers on the Toyota Camry VII, then with sets of Lockers that did not have and had soundproof lining.

The measurement of internal noise was carried out at a vehicle speed of 70 and 100 km / h.

Table 1 presents the results of measurements of sound levels and sound pressure levels in octave frequency bands at the driver’s workplace when the car is moving along a section with a flat surface of the dynamometer road at a speed of 70 km / h and sound level in dB (dBA) at the driver’s workplace.

Diagram 1 shows comparative graphs of sound levels and sound pressure levels in octave frequency bands at the driver’s workplace when the car is moving along a section with a flat surface of the dynamometer road at a speed of 70 km / h and sound level in dB (dBA) at the driver’s workplace.

Table 3 presents the results of measurements of sound levels and sound pressure levels in octave frequency bands at the driver’s workplace when the car is moving along a section with a flat surface of the dynamometer road at a speed of 100 km / h and sound level in dB (dBA) at the driver’s workplace.

Table 4 presents the results of measurements of sound levels and sound pressure levels in octave frequency bands at the driver’s workplace when the car is moving along a section with a broken dynamometer road surface at a speed of 100 km / h and sound level in dB (dBA) at the driver’s workplace.

Based on the above tables, we can conclude that the effect of noise reduction is observed at a speed of 70 km / h with HDPE wing flaps with an additional nonwoven fabric pad installed on the car compared to HDPE wing flaps without additional noise insulation. At a speed of 100 km / h, the noise level is reduced by 3-4.6 dB (more than 50%), and in the range of frequency bands from 63 Hz to 16 Hz it decreases by more than 3-10 dB (more than 1.5 -3 times).

Thus, it has been proved that the use of wing flaps with noise-insulating linings made of the nonwoven fabric obtained by the proposed method improves the acoustic comfort in the passenger compartment and reduces the fatigue of the driver and passengers.

Claims (7)

1. A method of manufacturing a fender liner with noise insulation, which consists in the fact that one or more noise absorbing pads of non-woven synthetic material are fixed in predetermined places from the inside of the matrix, after which a heated sheet of polymer material is applied to the matrix and its edges are fixed on the matrix, then create vacuum between the matrix and the sheet, after which the resulting liner is cooled and its final processing is carried out. 2. The method according to claim 1, characterized in that the fixation of the pads on the matrix is carried out using textile fasteners such as Velcro. 3. The method according to claim 1, characterized in that the final processing includes filing the fender. 4. The method according to claim 1, characterized in that the final processing includes the formation in the specified places of the fender liner holes by drilling and / or punching. 5. A soundproofed wing liner comprising a flexible molded body, at least on the part of the outer side of which a layer of non-woven synthetic material is fixed during molding. 6. The fender liner according to claim 5, characterized in that the edge of the front wall of its body is folded to the outside with the formation of a protrusion located in the longitudinal direction, configured to be placed on the inside of the edge of the wing of the car body. 7. The fender liner according to claim 5, characterized in that at least one side of its body is flanged in the form of a visor, the width of which corresponds to the width of the wheel niche of the car body.

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