JPS5935378Y2 - Reinforcement device for plastic molded products - Google Patents

Description

[Detailed description of the invention] This invention relates to a reinforcing device for plastic molded products that constitute the housing of electronic devices such as television receivers. When joining with reinforcing ribs, the desired reinforcing ribs can be formed without causing molding defects such as sink marks or flow marks on the externally exposed surface.

FIG. 1 shows a conventional device of this type.

Conventionally, a boss 2 was provided integrally protruding from the internal bottom surface to reinforce the externally exposed wall 1 of a plastic molded product, and the boss 2 and the externally exposed wall 1 were integrally connected by a reinforcing rib 3. Ta.

When resin molding is performed as described above, since plastic has the property of shrinking after molding, the reinforcing ribs 3 will be in a state of pulling the external exposed wall 1 and the molded boss 2 after molding, and therefore the external exposed wall 1 Then, the molded bosses 2 are tilted in a direction in which their tips approach each other.

In this case, the joint portion between the externally exposed wall 1 and the rib 3 is depressed, and the surface of the externally exposed wall 1 appears to have a sink mark.

The present invention eliminates these conventional drawbacks.

An example of this will be described below with reference to FIGS. 3 to 5.

In the figure, 4 is an externally exposed wall of a plastic molded product molded in an oval shape, for example, a front wall, and 5 is a boss located close to the externally exposed wall 4, and is approximately perpendicular to the externally exposed wall 4. It is integrally provided to protrude from the inner surface of the wall surface 6 to be joined.

A first reinforcing rib 7 is integrally formed between the boss 5 and the externally exposed wall 4 so that one end is connected to the boss 5 and the other end is connected to the wall surface 6. It is installed at a length that does not reach the exposed wall 4, and has a substantially triangular shape.

Reference numeral 8 denotes second reinforcing ribs that are integrally molded to be located on both sides of the first reinforcing rib 7 so as to sandwich it, and to face the first reinforcing rib 7, one end of which is connected to the externally exposed wall 4.
It has a substantially triangular shape so that the other end is joined to the inner surface of the wall 6 and the other end is joined to the wall surface 6.

According to the above structure, the boss 5 is provided close to the externally exposed wall 4, and the first reinforcing rib 7 and the second reinforcing rib 8 are arranged close to each other on both sides thereof. Since they are provided so as to face each other, the reinforcing effect is comparable to that of the conventional reinforcement rib 3 that connects the externally exposed wall 1 and the boss 2, but it also eliminates the drawbacks of the conventional method. It is possible to eliminate molding defects such as sink marks on the surface of the externally exposed wall.

That is, when the external exposed wall 4 is pushed and a force is applied according to the Yu H law, the force is first transmitted to the wall surface 6 via the pair of second reinforcing ribs 8, and the external exposed wall 4 and the wall surface 6 are The joints are reinforced to prevent breakage.

Furthermore, due to this force being applied to the wall surface 6, a large strain occurs near the tip of the second reinforcing rib 8; This force is transmitted to the first reinforcing rib 7 through the wall surface 6, and the first reinforcing rib 7 and the boss 5 strengthen the wall surface 6. will be distributed over a wide area.

Therefore, even if a force is applied to the externally exposed wall 4, the large force is not concentrated on the joint between the externally exposed wall 4 and the wall surface 6 or on a specific part of the wall surface 6, and is dispersed over a wide range. This eliminates the risk of damage or deformation.

Conversely, the same is true when a large force is applied to the boss 5, and the force is dispersed over a wide range, making it possible to prevent the boss 5 from being damaged and the wall surface 6 from deforming.

Furthermore, by forming the first and second reinforcing ribs 7.8 separately as described above, the parts to be reinforced, that is, the externally exposed wall 4 and the wall surface 6, are pulled together by contraction after molding. Therefore, the externally exposed wall 4 does not incline, and since pickets and flow marks do not occur on the surface of the externally exposed wall 4, the surface of the externally exposed wall 4 can be flattened without causing molding defects.

Note that the same applies when a rib is provided instead of the boss 5.

As described above, according to the present invention, the first reinforcing rib is provided between the boss or rib and the externally exposed wall, and has a length that does not reach the externally exposed wall from the boss or rib. Since a pair of second reinforcing ribs are provided on both sides of the first reinforcing rib, facing each other so as to sandwich the first reinforcing rib,
Good molding can be performed without tilting the externally exposed wall or causing sink marks or flow marks on the surface of the externally exposed wall during molding.Furthermore, even if force is applied to the externally exposed wall, boss or rib, the force can be easily absorbed. It can be effectively dispersed over a wide area, prevent damage or deformation of the molded product, and provide sufficient reinforcement.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a conventional reinforcing device for plastic molded products, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 is a reinforcement device for plastic molded products according to an embodiment of the present invention. 4 is a sectional view taken along line B--B in FIG. 3, and FIG. 5 is a sectional view taken along line C--C in FIG. 3. 4...external exposed wall, 5...boss, 6...
...Wall surface that connects perpendicularly to the external exposed wall, 7, 8.
...Reinforcement ribs.

Claims (1)

[Scope of utility model registration request] A boss or rib is integrally provided on the inner surface of the wall surface of an abbreviated plastic molded product having an externally exposed wall and a wall surface joined to the wall surface at approximately right angles, and the boss or rib is integrally provided in the vicinity of the externally exposed wall. and the externally exposed wall, and a substantially triangular first reinforcing rib that connects each of the bosses or ribs and the wall surface so as not to reach the externally exposed wall. , a substantially triangular shape that faces the first reinforcing rib and is connected to the externally exposed wall and the wall surface so as to be located close to and parallel to both sides of the first reinforcing rib so as to sandwich the first reinforcing rib. A reinforcing device for plastic molded products provided with a pair of second reinforcing ribs.