JPH0687383A - Lid of glove box - Google Patents

Abstract

PURPOSE:To provide a lid of a glove box made of plastics which is molded integrally, whose manufacturing process is simplified and which is light in weight and can improve degree of freedom of design. CONSTITUTION:A lid 2 of a glove box made of plastics has a hollow section 4 and a support section 3 of the predetermined size which is connected integrally between opposing faces across the hollow section 4 at the predetermined position in the cross section.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic glove box lid obtained by hollow injection molding.

[0002]

2. Description of the Related Art The lid of a glove box on the dashboard of an automobile is manufactured by combining a plurality of preformed parts as shown in FIG. However, the combination of a plurality of parts has the drawbacks of high cost and a large number of assembly steps.

On the other hand, there is an attempt to integrally mold the lid of the glove box by blow molding, but there is a problem that deburring is required and there is no freedom in design.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an integrally molded plastic glove box lid which has a simplified manufacturing process, is light in weight, and has a high degree of freedom in design.

[0005]

SUMMARY OF THE INVENTION The present invention is a plastic glove box lid having a hollow portion,
It is a lid of a glove box characterized in that it has a support portion of a predetermined size that is integrally connected between the surfaces facing each other across the hollow portion at a predetermined position in the cross section.

The present invention will be described in detail below.

[0007]

FIG. 2 is a schematic view showing an example of the lid of the glove box of the present invention. Of these, (a) shows the appearance of the surface of the lid of the glove box, (b) shows the appearance of the back surface of the lid of the glove box, and (c) shows A of (b).
It is sectional drawing in the -A 'line.

The lid 2 of the glove box has 20 to 90
The hollow portion has a hollow ratio of%, and has a supporting portion 3 having a predetermined size at a predetermined position in the cross section. The support portion 3 is integrally connected between the surfaces facing each other with the hollow portion 4 in between, and forms a support wall or a support column.

The shape of the support portion 3 can be, for example, a linear wall shape, a corrugated shape, a polygonal wall shape such as a polygonal line shape, and a columnar shape such as a columnar shape, a prismatic shape, and an elliptic cylinder shape. In the case of a wall shape, a long one or a short one may be appropriately selected as needed. Further, the diameter in the case of forming a columnar shape can be appropriately selected as necessary.

The arrangement of the support portions 3 can be selected from various shapes, for example, radial, parallel line, grid, zigzag, etc. depending on the shape and size of the lid 2 of the glove box, the size of the hollow portion 4, and the like. You can Further, the wall-shaped and columnar support portions 3 can be mixed.

The support portion 3 of the lid 2 of the glove box is a support wall or a support column as described above, and is formed at a predetermined position and size. However, it is possible to surely maintain the required strength.

The lid 2 of the glove box can be molded by the hollow injection molding method and the mold 8 shown in FIG.

First, as shown in FIG. 3A, a molten resin is injected into the mold cavity 6. This injection can be performed not only in the so-called mold clamping state but also in a state in which the volume of the mold cavity 6 is arbitrarily expanded by moving the cavity surface 9 described later. The state of the mold 8 for injecting the molten resin may be selected according to the shape and hollowness of the lid 2 of the glove box to be molded.

The injection amount of the molten resin is adjusted according to the shape and the hollowness of the lid 2 of the glove box, but the shape of the mold cavity 6 has no uneven thickness and the gate 1
When the shape is almost symmetrical with respect to 0, the movable core 7
Is preferably 40 to 95% with respect to the volume of the mold cavity 6 in the state of being projected into the mold cavity 6. Further, when the mold cavity 6 has a shape with uneven thickness and a thin wall portion, the amount is sufficient to fill the mold cavity 6 with the movable core 7 protruding into the mold cavity 6. It is preferable. In the latter case, the hollow ratio is determined by the expansion ratio of the mold cavity volume due to the retreat of the movable core 7 and the movement of the cavity surface 9.

In the following description, the mold cavity 6 in which the movable core 7 is projected into the mold cavity 6 will be described.
The case where injection is performed in an amount smaller than the amount that satisfies the above is referred to as "short shot", and the case where the injection is performed in an amount sufficient to fill the mold cavity 6 in the same state is referred to as "full shot".

The injection of the molten resin is usually carried out with the movable core 7 projecting into the mold cavity 6 as shown in FIG. 3 (a). Alternatively, the movable core 7 may be projected after the injection of the predetermined amount of molten resin is completed.

Next, as shown in FIG. 3B, the pressurized fluid is pressed into the molten resin in the mold cavity 6 with the movable core 7 projecting into the mold cavity 6. In the case of a short shot, the molten resin in the mold cavity 6 remains in contact with the wall surface of the mold cavity 6 and the movable core 7 and remains uncooled due to cooling, while the uncooled resin inside is easily flowable. Are pushed into the mold cavity 6 by the pressurized fluid to form the hollow portion 4. Further, in the case of full shot, the hollow portion 4 is formed by injecting the pressurized fluid in an amount corresponding to the volume contraction amount caused by cooling the molten resin.

The pressurization of the pressurized fluid into the mold cavity 6 is
Usually, it can be performed from the gate 10 through the injection path of the molten resin. However, depending on the shape of the lid 2 of the glove box and the like, the gate 10 which is the supply port of the molten resin is not used, and the mold cavity 6 is provided with a dedicated pressure inlet for the pressurized fluid, and It is also possible to directly pressurize the pressurized fluid.

In the case of a short shot, the pressurization of the pressurized fluid can be carried out together with the injection of the molten resin or after the injection of a predetermined amount of the molten resin is completed. In the case of full shot, it is performed after completion of injection of a predetermined amount of molten resin.

Simultaneously with the press-fitting of the pressurized fluid, or during or after the press-fitting, the movable core 7 is retracted from the projecting position in the mold cavity 6 to a predetermined position as shown in FIG. 3 (c). In the gap formed by the retreat of the movable core 7, the resin in the peripheral portion moves and is crushed, and the support portion 3 is formed. The support portion 3 is always formed at the position of the movable core 7 according to the shape of the movable core 7. Therefore, by appropriately selecting the installation position and the shape of the movable core 7, it is necessary to provide the necessary position. The supporting portion 3 having a size and a shape can be formed.

The position at which the movable core 7 is provided supports the two surfaces facing each other across the hollow portion 4 depending on the shape of the lid 2 of the glove box to be molded and the size of the hollow portion 4. It suffices to select the place that needs to be reinforced. The shape of the movable core 7 is, for example, a linear shape, depending on its reinforcement range and the like.
Flat plate shape such as wavy shape, polygonal line shape or circular shape,
By forming a polygonal shape, an elliptical shape, or the like in a pin shape in cross section, the obtained support portion 3 can be formed into various shapes such as a wall shape or a column shape, and the length, thickness, and diameter of the movable core 7 can be increased. It is possible to adjust the size of the support portion 3 obtained by adjusting the above.
In addition, the movable core 7 can be arranged in various ways such as a radial shape, a parallel line shape, a grid shape, and a zigzag shape. Also,
It is also possible to arrange the plate-shaped and pin-shaped movable cores 7 in a mixed manner.

The shape of the movable core 7 can be various shapes as described above, but if the shape is a pin shape having a circular cross section, the process for providing this on the die 8 is drilled. This is preferable because it is only necessary to process the mold 8 easily. Further, in the case of the pin-shaped movable cores 7, the columnar support portion 3 is formed when the distance between the movable cores 7 is increased, and when the distance between the movable cores 7 is narrowed, the movable cores 7 are formed. The wall-shaped support portion 4 is formed in a state where the spaces are continuous.

The retraction completion point of the movable core 7 is usually a point where the front end surface of the movable core 7 substantially coincides with the cavity surface 9. By retracting to this position, a recess is formed on the surface of the lid 2 of the glove box. The supporting portion 3 can be formed without leaving any convex portion. However, when molding the lid 2 of the glove box without any problem even if some concaves or convexes are formed on the surface, the movable core 7 is made with the front end surface of the movable core 7 protruding into the mold cavity 6. Can be stopped, or the movable core 7 can be retracted until the tip surface of the movable core 7 is slightly retracted from the cavity surface 9.

At the stage shown in FIG. 3 (c), the resin in the mold cavity 6 may be sufficiently cooled and the pressurized fluid in the hollow portion 4 may be discharged, and then the mold 8 may be opened. In order to further enlarge the hollow portion 4 and reduce the weight of the lid 2 of the obtained glove box, it is preferable to enlarge the mold cavity volume by moving the cavity surface 9 shown in FIG. 3 (d). The cavity surface 9 may be moved either before the movable core 7 is retracted, after the movable core 7 is retracted, or after the movable core 7 is retracted, at the same time or after the pressurization of the pressurized fluid is started. .

The cavity surface 9 to be moved is normally the cavity surface 9 on the side where the movable core 7 is provided, but it may be the cavity surface 9 on the opposite side or both cavity surfaces 9 facing each other.

When the mold cavity volume is expanded by moving the cavity surface 9 after the movable core 7 is retracted, the thickness and diameter of the support portion 3 can be made smaller than the thickness and diameter of the movable core 7. If it is performed before the movable core 7 is retracted, the thickness and diameter of the support portion 4 can be made larger than that after the movable core 7 is retracted. At any timing, the thickness and diameter of the supporting portion 3 obtained by adjusting the expansion rate of the mold cavity volume by adjusting the thickness of the movable core 7, its retreat distance, and the moving distance of the cavity surface 9, The hollow rate of the lid 2 of the glove box can be adjusted arbitrarily.

In this way, the required hollow portion 4 and supporting portion 3
After the shaping of the lid 2 of the glove box equipped with is completed, the pressure in the hollow portion 4 is returned to about normal pressure, the mold 8 is opened, and the lid 2 of the glove box is taken out.

To discharge the pressurized fluid in the hollow portion 4, the injection nozzle (not shown in FIG. 3) is separated from the mold 8 and the gate 10 is opened.
It can be carried out by releasing it into the atmosphere through. In addition, a pressurized fluid nozzle is built in the injection nozzle, or a recovery port is provided in the injection nozzle, and the pressure nozzle or the recovery port of the injection nozzle keeps the injection nozzle in pressure contact with the mold 8. The pressurized fluid can also be recovered for reuse.

The lid 2 of the glove box thus obtained is in a state in which a hole is opened at the place where the pressurized fluid is press-fitted. When the pressurizing fluid is pressed in through the gate 10 of the mold 8, the pressurizing fluid in the hollow portion 4 is discharged, and then a small amount of the molten resin is injected again to close the hole.

As the resin used in the present invention, all thermoplastic resins used in general injection molding or extrusion molding can be used, and if necessary, thermosetting resin can also be used. Further, various additives can be added to the resin as needed.

The pressurized fluid used in the present invention is a gaseous or liquid fluid at room temperature and atmospheric pressure, which does not react or mix with the resin used at the temperature and pressure at the time of injection. Specifically, for example, nitrogen gas, carbon dioxide gas, air,
Helium gas, water, glycerin, liquid paraffin and the like are preferable, but inert gas such as nitrogen gas and helium gas are preferable.

Next, a molding apparatus suitable for carrying out hollow injection molding of the lid of the glove box according to the present invention will be described with reference to FIG.

Reference numeral 11 in the drawing denotes an injection nozzle, and a pressurized fluid nozzle 12 is built in the injection nozzle 11. Further, the injection cylinder 13 behind the injection nozzle 11 is similar to a normal one and has a screw 14 built therein. When the screw 14 moves forward, the molten resin inside is extruded, so that a gap around the pressurized fluid nozzle 12 is generated. It is ejected from the injection nozzle 11 via the.

A compression cylinder 17 is connected to the pressurized fluid nozzle 12 via a check valve 15 and a valve 16. In the compression cylinder 17, the pressurized fluid is compressed by the forward movement of the piston 18 and is kept at a high pressure.
In addition, the pressurized fluid can be opened by opening the valve 20.
It is supplied into the compression cylinder 17 from a pressurized fluid source (not shown).

The mold 8 is provided with a movable core 7 on the side opposite to the pressure contact side of the injection nozzle 11, and the movable core 7 is provided.
Can be retracted by the hydraulic cylinder 19 and protrudes into the mold cavity 4 at the time of forward movement.

In the illustrated apparatus, all movable cores 7 are moved forward and backward simultaneously by one hydraulic cylinder 19, but the movable cores 7 are divided into several groups. It is possible to advance or retreat each time, or to move one by one separately.

According to the above-mentioned apparatus, the lid 2 of the glove box can be formed by pressing the injection nozzle against the mold 8 as shown in the figure and following the procedure described with reference to FIG.

When the lid of the glove box was actually molded, the lid of the glove box obtained had a width of 230 mm.
mm, length 430 mm, thickness 15 mm, weight 280
g, hollow ratio is 82%, there is no unevenness on the surface, it is lightweight,
Four wall-shaped supporting portions were formed inside the cross section corresponding to the position of the movable core of the mold. The minimum thickness of this support portion was 1.2 mm, and it extended radially from the center of the lid of the glove box and was continuous with the peripheral wall of the lid of the glove box. The lid of the obtained glove box had excellent rigidity.

[0039]

EFFECTS OF THE INVENTION The present invention is as described above, the manufacturing process is simplified, and the supporting portion of a desired size is formed at a desired position. Therefore, it is lightweight and has sufficient rigidity. It is the lid of the glove box.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a lid of a conventional glove box.

FIG. 2 is an explanatory view showing the lid of the glove box of the present invention.

FIG. 3 is an explanatory view of a hollow injection molding method suitable for manufacturing the lid of the glove box of the present invention and a mold used for the method.

FIG. 4 is an explanatory view of a molding apparatus suitable for hollow injection molding of the lid of the glove box of the present invention.

[Explanation of symbols]

 1, 2 Glove box lid 3 Support part 4 Hollow part

Claims (1)

[Claims] 1. A lid of a plastic glove box having a hollow portion, the support portion having a predetermined size that is integrally connected to a predetermined position in the cross section between the surfaces facing each other across the hollow portion. A glove box lid characterized by having.