JPH021649B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <<Field of the Invention>> This invention relates to a method of forming a rear parcel shelf for an automobile.

<<Prior Art and its Problems>> As is well known, a rear parcel shelf is disposed behind the rear seat of a passenger car, and there are various forms depending on the type of passenger car.

For example, a typical rear parcel shelf has a structure in which a resin substrate (approximately 1 to 5 mm thick) press-molded into a predetermined shape is reinforced with metal reinforcement.

The forming method of this kind of rear parcel shelf is
First, a small piece of a polypropylene resin sheet containing a cellulose filler or an inorganic filler is heated and softened and set on the lower die surface of a press mold, then a reinforcement is placed on the small piece of the resin sheet, and then , the resin substrates for forming the rear parcel shelf body are laminated, and then the upper press mold is engaged with the lower mold and pressed, thereby integrally molding the three parts.

In this case, the reinforcement is usually made of a hollow rectangular tube, which is relatively long and has a cross section of, for example, about 10 mm square.

As described above, the rear parcel shelf having a structure in which a metal reinforcement is reinforced with a resin sheet on a resin substrate has the following problems.

Firstly, weight reduction is a major issue in passenger cars, and since rainforths are generally made of metal and are installed in parallel on the underside of a resin substrate, the rear parcel shelf is Weight gain is inevitable.

Additionally, there were many limitations in terms of design, and there was also the problem that the shape of the rear parcel shelf could not be easily changed.

In other words, reinforcement generally reinforces a long and narrow surface, but the shape of the surface that requires reinforcement is not limited to this. For example, most of the bottom surface of the rear parcel shelf or the rear parcel shelf There are various forms depending on the shape of the product, such as only the lower surface of the outer periphery.

It is difficult to fully meet such demands using reinforcements, and therefore, the design of the rear parcel shelf must be limited to shapes that can be reinforced with reinforcements.

To make matters worse, the above structure causes the rear parcel shelf to warp. That is, although the metal reinforcement is attached to the lower surface of the resin substrate, warpage is a phenomenon caused by the difference in shrinkage rate between the two.

In other words, the conventional reinforcement structure is
For example, it is as shown in FIGS. 5A and 5B. In FIG. 5A, this fixing structure has a hollow structure having a rectangular cross section between the lower surface of a resin substrate 2 on which the skin material 1 is arranged and both surfaces of a small piece 3 for embedding made of the same material as this resin substrate 2. By arranging the reinforcement 4, making the resin substrate 2 and the small piece 3 into a semi-molten state (softened state), placing them between the upper and lower molds, and then pressing them together, the reinforcement 4 is integrated as shown in Figure B. It was designed to be buried in a safe manner.

However, in such a fixing structure, as shown in FIG. 6, the end portion of the reinforcement 4 is closed by the small piece 3, and when cold pressing is performed with this reinforcement inserted, the resin substrate 1 A difference in shrinkage occurs between the small piece 3 and the reinforcement 4 as they are cooled from a heated state to room temperature (resin shrinks more than metal).

In addition, since the reinforcement 4 is covered by the small pieces 3 at both ends thereof, the front surface of the resin substrate is warped as shown by the imaginary lines in FIG. 6.

The following structures have been proposed to prevent the warping. In this structure, as shown in FIG. 7, a resin end cap 5 is movably attached to the edge of the reinforcement 4.

The end cap 5 is composed of a flange portion 6 that is larger than the outer diameter of the reinforcement 4 and a guide portion 7 that is fitted into the inner peripheral portion of the reinforcement 4.

Such an end cap 5 is attached to the edge of the reinforcement 4 with a required gap provided between the flange portion 6 and the edge of the reinforcement 4.

Then, when a predetermined rear parcel shelf is molded and cooled, the resin substrate 2 and the small pieces 3 shrink, and the guide portion 7 of the end cap 5 moves into the edge of the rain force 4, causing the resin substrate 2, etc. to shrink. By adjusting the margin, the warping can be prevented.

However, this structure requires an end cap and a reinforcement, which inevitably increases the number of man-hours and costs.

≪Object of the Invention≫ The present invention was made in view of the above-mentioned conventional drawbacks, and an object of the present invention is to provide a method for forming a rear parcel shelf that is lightweight and has good strength. It is about providing.

≪Structure and Effects of the Invention≫ In order to achieve the above object, the method for molding a rear parcel shell for an automobile according to the present invention provides a method for molding a rear parcel shell for an automobile according to the present invention. a step of placing a substrate on one end of the first substrate, a step of setting an air outlet connected to a blowing device at one end of the first substrate, and a step of setting a second air outlet made of thermoplastic resin so as to sandwich the air outlet with the first substrate. By placing the substrate on the upper surface of the first substrate, immediately engaging and pressing the upper die onto the lower die, and pumping air from the air outlet, a space is formed between the resin plates. The first substrate and the second substrate are formed into a shape having the following steps.

That is, according to the method for molding a rear parcel shelf for an automobile according to the present invention, the upper and lower thermoplastic resin substrates have a general part where the upper and lower thermoplastic resin substrates are firmly laminated, and a space part between the resin substrates, and the whole can be shaped into a desired shape. You can get a molded rear parcel shelf.

Therefore, even if the conventional reinforcement is abolished, sufficient strength can be ensured and it can greatly contribute to making the product lighter.By abolishing the reinforcement, the product can be reduced due to the difference in shrinkage rate between the resin substrate and the reinforcement. Warping is also eliminated, and the appearance performance is also improved.

Furthermore, the double structure with a space between the resin substrates provides heat insulation and sound absorption effects.
It has various advantages such as maintaining quietness in the vehicle interior.

<<Description of Examples>> Hereinafter, one example of the molding method according to the present invention will be described in detail with reference to the drawings.

FIGS. 1 and 2 show each step of the method for molding a rear parcel shelf for an automobile according to the present invention.

In each figure, numeral 10 is a mold surface 10 of the desired shape.
11 shows the lower mold that formed the lower mold 1.
0 shows an upper mold formed with a mold surface 11a that engages with
Further, reference numeral 12 indicates an air outlet (nozzle) connected to the blow device B.

As shown in FIG. 1, on the mold surface 10a of the lower mold 10 of the press molding mold composed of the upper and lower molds 10 and 11, a backing sheet 13 and a first mold made of thermoplastic resin are placed. The substrates 14 are placed one after another.

Here, the backing sheet 13 is made of nonwoven fabric or woven fabric. The first substrate 14 made of thermoplastic resin is a polypropylene composite resin sheet containing a cellulose filler or an inorganic filler that is heated and softened in advance to a semi-molten state by heating means such as a heater.

After placing the backing sheet 13 and first substrate 14, the air outlet 12 is set at a predetermined position so as to be sandwiched between the first substrate 14 and a second substrate 15 made of thermoplastic resin, which will be described later.

Next, like the first substrate 14, a second substrate 15 made of a heat-softened thermoplastic resin and a skin material 16 are placed on the upper surface of the first substrate 14. Usually, skin material 16
For the second substrate 15, a material such as carpet, woven fabric, non-woven fabric, etc. is used, and for the second substrate 15, the same material as the first substrate 14 or a material having a similar shrinkage rate is used.

After placing the sheets of these materials, the upper and lower dies are immediately engaged and pressed as shown in FIG. The thermoplastic resin substrates 14 and 15 and the skin material 16 are integrally molded along the cavity shapes of both mold surfaces 10a and 11a, and the first substrate 14 on the lower surface is molded together with the backing sheet 13 by compressed air. Lower mold 1
0, the first substrate 1 is pressed by the groove 10b formed in the
A space 17 is formed between the substrate 4 and the second substrate 15 .

Thereafter, the cooled upper and lower molds are disengaged, the molded product is taken out, and the engaged edges of the molded product are trimmed to obtain the rear parcel shelf 20 shown in FIGS. 3 and 4. .

FIG. 3 is a partially cutaway perspective view of the rear parcel shelf obtained by this molding, and FIG. 4 is a partially cutaway perspective view showing the back side of the rear parcel shelf.

The rear parcel shelf 20 includes a second substrate 15 made of thermoplastic resin that is integrated with a first substrate 14 made of thermoplastic resin, a skin material 16 affixed to the upper surface of the second substrate, and the first substrate 14 . A backing sheet 13 is attached to the lower surface of the member, and each member is firmly fixed by an anchor effect or fusion bonding during the molding process.

The rear parcel shelf 20 is composed of a general part 20a in which each member is strongly laminated, and a reinforcing part 20b having a space 17 between the resin substrates, and the general part 20a has a recess 21 for storing small items. It is formed. The space 17 forms a groove that communicates with the whole, and even if a load is applied to the upper surface of the rear parcel shelf 20 due to luggage or the like, the bending deformation is extremely small and good strength can be obtained. In addition, in this embodiment, air is used in the molding space-time part 17.
However, depending on the shape, a plurality of locations may be set, and a cap may be fitted to the location as necessary. Furthermore, the skin material 16 and the backing sheet 13 may be omitted as appropriate depending on specifications.

[Brief explanation of drawings]

1 and 2 are sectional views showing a method of forming a rear parcel shelf according to the present invention, and FIG. 3 is a partially cutaway perspective view of a rear parcel shelf to which the method of forming a rear parcel shelf according to the present invention is applied. Figure 4 is a partially cutaway perspective view showing the back side of the same rear parcel shelf, Figures 5A and B are cross-sectional views showing the conventional reinforcement fixing structure of the rear parcel shelf, and Figure 6 is a diagram showing the unfinished structure of the above-mentioned fixing structure. A partial sectional view showing the structure of the end attachment part,
FIG. 7 is a perspective view showing an end cap added to the fixing structure. DESCRIPTION OF SYMBOLS 10... Lower mold for press molding, 11... Upper mold for press molding, 12... Air outlet, 13... Backing sheet, 14... First substrate, 15... Second substrate,
16... Skin material, 17... Space section, 20... Rear parcel shelf, 20a... General section, 20b...
...Reinforcement part.

Claims (1)

[Claims] 1. A step of placing a first substrate made of heat-softened thermoplastic resin on the lower mold surface of a press molding die, and a step of setting an air outlet connected to a blowing device at one end of this first substrate. , placing a second substrate made of thermoplastic resin on the upper surface of the first substrate so as to sandwich the air outlet with the first substrate, and then immediately engaging and pressing the upper mold onto the lower mold. and a step of molding the first substrate and the second substrate into a shape having a space between the resin plates by feeding air under pressure from the air outlet. How to mold an elf.