JPH09155989A - Hollow plate and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hollow plate with a fixed part which is free from a deformation such as a warp and has a superior joining strength and a high durability and a method for manufacturing the hollow plate. SOLUTION: This hollow plate P has a front wall 1 and a rear wall 2 spaced in between at a mutually opposed position, and the peripheral part of these walls is blocked by an end wall 3. In addition, an inner rib 4 is internally provided which has one of its end sides deposited on the rear face of the front wall 1 and the other end side formed integrally with the rear wall 2. Further, a fixed part 6 projected into one direction crossing the longitudinal direction of the inner rib 4 on the front wall side has an implanted bar-like form 5 protruded on both end parts. Besides, the tip face of the fixed part 6, i.e., the face in which a screw hole 6a is formed is exposed to the outer face of the rear wall side, and a space part 7 encircling the outer faces of both end parts of the bar-like form 5 including the fixed part 6 is formed adjacent to both ends of the inner rib 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow plate made of a thermoplastic resin having a front wall and a back wall facing each other with a space therebetween, and a method for manufacturing the hollow plate.

[0002]

2. Description of the Related Art Conventionally, as a method for manufacturing a hollow plate made of a thermoplastic resin which has a front wall and a back wall opposed to each other and which is excellent in mechanical strength such as rigidity, the following method will be described. There is.

As shown in FIG. 5 (a), the molds 121 and 122 of the split type are opened, and the reinforcing core material 103 is set on a holder 123 arranged in one mold 122 so as to be able to move back and forth. Then, the parison 124 is arranged between the molds 121 and 122, the mold is closed, and then a pressurized fluid is supplied into the parison 114 to perform blow molding along the surfaces of the cavity and the reinforcing core 103. Then, in the middle of this blow molding, as shown in FIG. 5B, the holder 123 is retracted so that the tip of the holder 123 is flush with the cavity surface of the one die 122, and the reinforced core material 103 is A method for manufacturing a hollow plate body 101 having an inner rib 102 which is internally provided and is invisible from the outside (see Japanese Patent Publication No. 61-21125).

[0004]

However, in the above conventional technique, the hollow plate member is deformed such as a warp due to the difference in expansion and contraction due to the difference in the coefficient of thermal expansion between the reinforcing core material and the base resin. Further, in order to connect the hollow plate body and other members, it is necessary to form a fixing portion for connecting the other member to the hollow plate body by post-processing etc., but the fixing formed by such post-processing There is a problem that the part is inferior in bonding strength and durability with the hollow plate itself.

The present invention has been made in view of the above-mentioned problems of the prior art, and is a hollow plate having a fixing portion which is free from deformation such as warpage and which is excellent in bonding strength and durability. It is intended to realize a body and a manufacturing method thereof.

[0006]

In order to achieve the above object, in the method for manufacturing a hollow plate body of the present invention, one end side is inside the hollow plate body having a front wall and a back wall facing each other with a space therebetween. A hollow plate body having an inner rib integrally welded to the back wall while being welded to the back surface of the front wall, wherein the front wall side of the inner rib is in one direction intersecting the longitudinal direction. A rod-shaped body having fixed portions protruding toward both ends is embedded, and the tip end surface of the fixed portion is exposed to the outer surface of the back wall side, and the rod-shaped body including the fixed portion is formed. It is characterized in that space portions surrounding outer surfaces of both end portions of the body are formed adjacent to both ends of the inner rib.

Further, inside the hollow plate having a front wall and a back wall facing each other at a distance, one end side is welded to the back surface of the front wall and the other end side is integrally molded with the back wall. A method of manufacturing a hollow plate body provided with ribs, wherein one mold having a cavity that regulates an outer surface of the front wall and the other mold having a cavity that regulates an outer surface of the back wall are opened. , The slide dies respectively disposed at both end portions of the portion where the inner rib is to be formed in the other die, so that the distance between the tip end surface and the cavity of the one die is substantially equal. A stick-shaped body that has protruding and protruding fixing portions at both ends that protrudes in one direction intersecting the longitudinal direction is formed so that the surface on the side opposite to the fixing portion is flush with the tip surface of the slide die. Provided in a slide type Both ends of the rod-shaped body, including the fixing portion, are detachably inserted into the fitting holes to hold the rod-shaped body in a suspended state, and a parison is placed between the one die and the rod-shaped body, and then the mold is closed. Then, while sandwiching the parison, a recess is formed by projecting and deforming a part of the part that becomes the back wall of the parison through the rod-shaped body and the slide mold, and the tip thereof becomes the part that becomes the front wall. By welding and then introducing a pressurized fluid into the parison, it is expanded along the outer surface of the cavity and the slide mold, and at the same time, the void between the two slide molds of the recess is compressed by the internal pressure of the pressurized fluid. By pressing and deforming with, the opposing wall surfaces are welded to form the inner rib in which the rod-shaped body is embedded on the front wall side, and both ends of the rod-shaped body including the fixing portion are formed. It is characterized in that to form the space portion surrounding the surface adjacent to both ends of the inner rib.

[0008]

Since the sticking portions project from both ends of the rod-shaped body embedded on the front wall side of the inner rib, the bonding strength and durability with the hollow plate itself are increased. Further, since the space portion surrounding the outer surfaces of both ends of the rod-shaped body including the protruding fixing portion is formed adjacent to both ends of the inner rib,
The difference in expansion and contraction due to the difference in the coefficient of thermal expansion between the rod-shaped body on which the fixing portion is provided and the base resin is absorbed in the space portion, and there is no risk of deformation such as warpage in the hollow plate body.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings.

First, an embodiment of the hollow plate member according to the present invention will be described.

FIG. 1 shows a table using the hollow plate body of the present embodiment, in which a screw hole 6a provided in each fixing portion 6 of the hollow plate body P has a through hole 9a formed in a leg member 9. The pair of leg members 9 are joined to the hollow plate P by screwing the bolts 8 that have been fitted and inserted.

As shown in FIGS. 1 and 2, the hollow plate P has a front wall 1 and a back wall 2 facing each other with a space therebetween,
The peripheral portions of both are closed by an end wall 3, and one end side between the front wall 1 and the back wall 2 inside the hollow plate P is the front wall 1.
The inner rib 4 is integrally welded to the back wall 2 and is welded to the back surface of the inner wall 4. On the front wall side of the inner rib 4, there is embedded a rod-shaped body 5 having fixed portions 6 projecting in one direction intersecting the longitudinal direction and projecting from both ends thereof. That is, the surface in which the screw hole 6a is formed is exposed to the outer surface on the back wall side, and the space portion 7 surrounding the outer surface of both ends of the rod-shaped body 5 including the fixing portion 6 is adjacent to both ends of the inner rib 4. It was formed.

In this embodiment, in order to reduce the weight, the rod-shaped body 5 has a hollow prismatic shape, and the threaded hole 6a is formed in the tip surface of the fixing portion 6 in advance. It may be a solid cylinder or prism, and the screw hole 6a may be formed by post-processing.

Next, an embodiment of the method for manufacturing a hollow plate according to the present invention will be described.

The present embodiment is a method for manufacturing the hollow plate P shown in FIGS. 1 and 2, and as shown in FIG. 3, a cavity 11 a that regulates the outer surfaces of the front wall 1 and the end wall 3. And a cavity 12a that regulates the outer surface of the back wall 2, and is movable back and forth with respect to the one die 11 disposed at both end portions of the portion where the inner rib is to be formed. The mold 12 is opened with the other mold 12 having the pair of slide molds 13,
Each of the slide molds 1 so as to protrude so that the distance between the tip surface of the mold 11 and the cavity 11a of the mold 11 is substantially equal.
By detachably inserting both ends of the rod-shaped body 5 including the fixing portions 6 protruding at both ends into the fitting hole 13a of No. 3, the surface of the rod-shaped body 5 on the side opposite to the fixed portion and each slide type. The tip end surface of 13 is held in a suspended state so that it is almost the same surface.

Here, the fitting holes 13a of both slide molds 13 are provided.
As shown in FIG. 4C, a notch portion 13b into which the rod-shaped body 5 is detachably fitted is provided on the opposing surfaces of the two, and the rod-shaped body 5 is inserted into each fitting hole 13a. When the both ends including the fixing portion 6 are fitted and inserted, the surface of the rod-shaped body 5 on the side opposite to the fixing portion can be held in a suspended state so as to be substantially flush with the tip surfaces of both slide molds 13. It is configured.

Further, both slide dies 13 are configured to be advanced and retracted toward one of the dies 11 by being coupled to a linear drive means such as a fluid pressure cylinder (not shown) via a rod 14.

After the above steps, the one mold 1 opened by extruding a parison 15 made of a molten thermoplastic resin from an extrusion head 16 of an extruder (not shown)
After arranging between 1 and the rod-shaped body 5, mold closing is started. As the mold closing progresses, as shown in FIG. 4A, a part of the back wall of the parison 15 becomes a front wall by the slide molds 13 and the rod-shaped body 5 held in a suspended state. 4D, the groove-shaped recess 15a following the slide mold 13 and the rod-shaped body 5 is formed, and when the mold closing is completed, the recess 15a is formed as shown in FIG. 4B. The front end portion of is welded to the back surface of the portion that becomes the front wall of the Paris 15 to form the welded portion 15b.

In this step, before the completion of mold closing, the tip opening of the parison 15 is closed, and a predetermined amount of pressurized fluid such as pressurized air is introduced by the blowing means provided in the extrusion head 16, so-called pre-blow. It is recommended to complete the mold closing after performing.

Further, both slide dies 13 are made to project at a length slightly shorter than the projection length at the completion of the mold closing at the start of the mold closing, and the projecting length is increased as the mold closing progresses to complete the mold closing. In accordance with the above, it is possible to project to the projecting length when the mold closing is completed.

After the above steps, as shown in FIG. 4C, a blowing means such as a blowing needle (not shown) is pierced into the parison 15 and a pressurized fluid is introduced into the parison 15, whereby the cavity 11 a , 12a and the outer surface of the slide mold 13 and at the same time expanded by the internal pressure of the pressurized fluid, both slide molds 1 of the recess 15a.
By pressing and deforming the void portion between the three and welding the opposing wall surfaces to be integrated, one end side is the front wall 1
The inner rib 4 is welded to the rear surface of the rod and the other end of the rod is integrally formed with the back wall 2, and the rod 5 is embedded in the front wall. Rod-shaped body 5 including the fixed portion 6 provided
A space 7 is formed so as to surround the outer surfaces of both ends of the.

After the above steps, after cooling in the mold, both slide molds 13 are completely drawn into the other mold 12, and then the molds are opened to take out the hollow plate P.
Remove unnecessary burrs.

In the present embodiment, the rod-shaped body has a hollow prismatic shape, but it may have a cylindrical shape or a hollow polygonal shape. Also, the fixing portion can have any shape such as a cylindrical shape, a prismatic shape, an elliptic cylinder shape, or the like, and the protruding length is such that the front end surface is flush with the back wall. However, the length may be such that the tip end surface slightly projects from the back wall, or the tip end surface is recessed from the back wall as necessary.

In the present invention, as the thermoplastic resin, ABS resin, modified polyphenylene oxide resin, polycarbonate, polyamide, polypropylene and the like are used.

Further, the application of the hollow plate body of the present invention is such that it is lightweight, excellent in mechanical strength and durability, and is required to have good appearance, such as cabinet shelves, table top plates, housings for electric devices, etc. There are outer panels for automobiles.

[0026]

Since the present invention is configured as described above, it has the following effects.

The warp due to the difference in expansion and contraction due to the difference in the coefficient of thermal expansion between the rod-shaped body and the base resin in which the fixing portions projecting in one direction are provided at both ends embedded on the front wall side of the inner rib. And the like, and the fixed portion has excellent bonding strength and durability, and has a good appearance and high mechanical strength such as rigidity.

[Brief description of the drawings]

FIG. 1 shows a table using an embodiment of a hollow plate of the present invention, (a) is a schematic perspective view, (b) is AA of (a).
It is a schematic partial cross section along a line.

FIG. 2 shows a main part of an embodiment of a hollow plate of the present invention, (a) is a schematic partial plan view seen from the back wall side, (b) is a schematic part taken along line BB of (a). FIG.

FIG. 3 is an explanatory view of one step of the method for manufacturing a hollow plate body of the present invention.

FIG. 4 is an explanatory view of another step after the step shown in FIG. 3 in the method for manufacturing a hollow plate body of the present invention.

FIG. 5 is an explanatory view showing the steps of a conventional method for manufacturing a hollow plate body.

[Explanation of symbols]

 1 front wall 2 back wall 3 end wall 4 inner rib 5 rod-shaped body 6 fixing part 6a screw hole 7 space part 8 bolt 9 leg member 11 one mold 11a, 12a cavity 12 the other mold 13 slide mold 13a fitting hole 13b Notch 14 Rod 15 Paris 15a Recess 15b Welding 16 Extrusion head

Claims (2)

[Claims] 1. An inner member having one end side welded to the back surface of the front wall and the other end side integrally formed with the back wall inside a hollow plate having a front wall and a back wall facing each other at a distance. A hollow plate body provided with ribs, on the front wall side of the inner rib, a stick-shaped body projecting at both ends with a fixing portion projecting in one direction intersecting the longitudinal direction is embedded, Moreover, the tip end surface of the fixing portion is exposed to the outer surface on the back wall side, and the space portion surrounding the outer surface of both ends of the rod-shaped body including the fixing portion is formed adjacent to both ends of the inner rib. A hollow plate body characterized by being. 2. An inner member in which one end side is welded to the back surface of the front wall and the other end side is integrally formed with the back wall inside a hollow plate having a front wall and a back wall facing each other at a distance. A method of manufacturing a hollow plate body provided with ribs, wherein one mold having a cavity that regulates the outer surface of the front wall and the other mold having a cavity that regulates the outer surface of the back wall are opened. , The slide dies respectively disposed at both end portions of the portion where the inner rib is to be formed in the other die, so that the distance between the tip end surface and the cavity of the one die is substantially equal. A stick-shaped body that has protruding and protruding fixing portions at both ends that protrudes in one direction intersecting the longitudinal direction is formed so that the surface on the side opposite to the fixing portion is flush with the tip surface of the slide die. It was provided in the slide type Both ends including the fixing portion of the rod-shaped body are detachably inserted into the dowel to hold the rod-shaped body in a suspended state, and a parison is arranged between the one die and the rod-shaped body, and then the mold is closed. While sandwiching the parison, a part of the back wall of the parison is projected and deformed through the rod-shaped body and the slide mold to form a recess, and the tip is welded to the part serving as the front wall. ,
Then, by introducing a pressurized fluid into the parison, the cavity and the outer surface of the slide die are expanded, and at the same time, the void between the slide dies of the recess is pressed and deformed by the internal pressure of the pressurized fluid. By doing so, the opposing wall surfaces are welded to each other to form the inner rib in which the rod-shaped body is embedded on the front wall side, and the space portion surrounding the outer surfaces of both ends of the rod-shaped body including the fixing portion is formed into the inner rib. A method for manufacturing a hollow plate body, characterized in that the ribs are formed adjacent to both ends of the rib.