JPS6331368B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention includes a loading panel portion that encloses reinforcing materials assembled in a vertical and horizontal lattice pattern, and a plurality of closed loop-shaped girder portions that are connected to the lower side of the loading panel portion. The present invention relates to a method of molding a synthetic resin molded body for forming a pallet, which is injection molded into a shape.

One of the conventional means for holding the reinforcing material in position in the cavity during molding is to clamp and fix the reinforcing material at multiple points from the thickness direction of the loading plate surface using a pair of front and back pins. Yes, but
In this case, if the molten resin injected into the cavity is held between pins until it solidifies, the positioning effect will be very reliable, but the resin will not wrap around the pin marks and the reinforcing material will be exposed. A place was created,
This poses problems in terms of appearance and rust prevention. As a countermeasure for this, while the molten resin has fluidity, the front pin of the pair of front and back pins is removed from the cavity, and the position of the reinforcing material is maintained by pushing the injected resin from the front side to the back side. The pressure is controlled by the cooperation of the reaction force from the pin on the back side, and the surface side of the molded product where appearance is more important, that is, the upper surface side of the loading platen part, is made to flow through the void where the pin exits. A technique has been proposed that creates a beautiful finish by filling it with resin.

However, in this case, various conditions such as the relationship between the weight of the reinforcing material and the pressing force of the injected resin, the relationship between resin flow characteristics and the timing of pin withdrawal, and other various conditions are complexly related, making it difficult to set comprehensive conditions. difficult to
For this reason, the effect of filling voids on the upper surface side of the loading plate surface portion is insufficient, and as a result, it is difficult to avoid the appearance of dents or streaks that can be seen as traces of voids.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to make the upper surface of the loading board surface beautiful while ensuring that the position of the reinforcing material is maintained. An object of the present invention is to provide a method for molding a synthetic resin molded article for forming a pallet, which is also advantageous in terms of rust prevention.

The characteristic structure of the method for molding a synthetic resin molded body for forming a pallet according to the present invention is that, of the reinforcing material enclosed in the loading board surface part, a closed loop-shaped girder part that is continuous to the lower side of the loading board surface part is formed. The reinforcing material is held in position within the cavity of the molding form by sandwiching the reinforcing material in a direction parallel to the surface direction of the loading board surface portion, and its functions and effects are as follows. That's right.

That is, the reinforcing material part located at the molding part of the girder part located on the lower surface side of the loading board surface part is held in a direction parallel to the surface direction of the loading board surface part,
This is to hold the reinforcing material in position within the cavity of the molding form, and if it is clamped from a direction parallel to the surface direction of the loading plate surface, the reinforcing material can be reliably positioned just by clamping it. .

Therefore, even if the desired positioning is performed by using a pin that moves in and out from the upper surface of the loading board in the thickness direction of the board, the pin will move out when resin is injected. It is possible to prevent the upper surface of the loading plate from causing dents or streaks, which are conventionally seen, by retracting it in the latter half of the injection process. By reliably suppressing the misalignment of the material, the thickness of the resin coating on the reinforcing material can be made uniform, and the reinforcing material can be properly molded.

Furthermore, synthetic resin molded bodies for forming pallets are used as pallets by joining the lower ends of the girders to the lower ends of the girder parts of other molded bodies, and therefore, they cannot be used as pallets. When in use, moisture does not infiltrate into the girder, so the reinforcing material inside the girder is not coated with resin due to the clamping, but rusting is suppressed.

Therefore, we have achieved a method for molding a synthetic resin molded body for forming a pallet, which allows for proper molding while making the upper surface of the loading plate surface beautiful, and which is also advantageous in terms of rust prevention of the reinforcing material.

Next, embodiments of the present invention will be described based on the drawings.

Position holding device A used in the molding method of the present invention
As shown in FIG.
A pin 6 that can move in and out toward the other wall 5 is attached to one of the walls 4, and the reinforcing material is clamped and fixed between the pin 6 and the other wall 5. ing. 7 is a movable member that moves the pin 6 in and out by swinging.

As a means for moving the pin 6 in and out, a link, a cam, a pinion rack, or a fluid pressure may be used instead of the above-mentioned swingable movable member 7.
When setting the reinforcing material 1 in the cavity a of the molding frame, in order to make it easier for the reinforcing material 1 to enter the groove 2, the receiving surface 5a of the other wall 5 is made so that the groove width becomes larger toward the opening side. It is effective to have a tapered surface.

The synthetic resin molded bodies for pallet construction are shown in Figure 2.
The palette shown in FIG. 3 is divided into two in the vertical direction, and is illustrated in FIG. 4. This synthetic resin molded body has reinforcing members 1, 1'... assembled in a vertical and horizontal lattice pattern enclosed in the loading board part 9, and closed-loop girder parts 10... are integrally attached to key points of the board part 9. This is what I did. For reinforcement material 1, use a flat bar.
A round pipe or a round bar is used as the reinforcing material 1'. Both 1 and 1' have their upper ends flush with each other as shown in FIG.

In order to hold the lattice reinforcing members 1, 1'... in position within the cavity a, the girder portions 1 are attached as shown in FIGS. 6 and 9.
At the molding location No. 0, the position holding device A;
Use fixed blocks B and C. Block B is the 7th
As shown in the figure, the pin 6 is removed from the position holding device A, and both A and B hold the flat bar 1. Block C targets a round pipe (round bar) 1' as shown in FIG. The position holding device A holds the reinforcing members 1, 1' in a direction parallel to the surface direction of the loading plate portion 9, and holds the reinforcing members 1, 1' in position within the cavity a of the molding frame. However, as shown in FIG. 9, the above three members A, B, and C are provided on the movable mold 11 side. Fixed mold 12 with an injection port (not shown) for molten resin
An ejection/retraction pin 13 is also attached to the side, but this only controls initial positioning and is ejected from the cavity a during injection.

The method of the present invention can be carried out using the apparatus A shown in Fig. 1, as well as the apparatus A' shown in Fig. 10 and the apparatus A'' shown in Fig. 11. The device A' shown in FIG. 10 has two sets of pins 6 that are moved in and out by a movable member 7 in opposing positions, and the flat bar 1 is held between these pairs of opposing pins 6, 6. The device A″ in FIG. 11 has a pair of clamping arms 14,
14 are pivotally connected via a shaft 15.

[Brief explanation of the drawing]

The drawings illustrate a method of molding a synthetic resin molded body for forming a pallet according to the present invention, in which Fig. 1 is a sectional view of the main part of the position holding device, Fig. 2 is a plan view of the pallet, and Fig. 3 is a front view thereof. , FIG. 4 is a cross-sectional plan view, FIG. 5 is an explanatory diagram of the assembled state of the reinforcing material, FIG. 6 is an explanatory diagram of the reinforcing material position holding mode, and FIGS. 7 and 8 are other positions used during molding. FIG. 9 is a schematic cross-sectional view of the entire molding die, and FIGS. 10 and 11 are cross-sectional views showing modified examples of the device that can be used in carrying out the method of the present invention. . 1, 1'...Reinforcement material, 9...Loading board surface part,
10... Girder part, a... Cavity.

Claims (1)

[Claims] 1 Loading plate surface portion 9 that encloses reinforcing members 1, 1' assembled in a vertical and horizontal grid pattern, and its loading plate surface portion 9
A plurality of closed loop girder parts 10 connected to the lower side of the
A method of molding a synthetic resin molded body for forming a pallet by injection molding in a state comprising A method of molding a synthetic resin molded body for forming a pallet, in which the reinforcing members 1 and 1' are held in position in a cavity a of a molding frame by sandwiching them in a direction parallel to the surface direction of the portion 9.