JPH0321942Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to an edging forming device for integrally forming an edging member on the peripheral edge of a plate-like object, particularly a fragile plate-like object such as glass, by injection molding.

(Prior Art) In recent years, as a method of joining a edging member to the peripheral edge of a plate-shaped body, a plate-shaped body is inserted through fixed and movable mating seal members, and the peripheral edge is exposed to the cavity. A edging member is integrally formed on the peripheral edge by injection molding resin.

FIGS. 2 and 3 show an example of the edging forming apparatus. In these figures, numeral 1 is a fixed mold fixed to a fixed mounting plate 2, and numeral 3 is a movable mold fixed to a base 4 with a backup plate 5 interposed therebetween. Seal members 6a and 6b are provided on each of the fixed mold 1 and the movable mold 3 to substantially face each other, and the fixed mold 1 is provided with a receiving member 7 located approximately in the center thereof. The seal members 6a and 6b are made of an elastic material, and in the illustrated mold closed state, they sandwich the plate-shaped body 8 and insert it into the mold, and also connect it to the inner walls of the fixed mold 1 and the movable mold 3. It serves to form a cavity 9 between them. Further, the receiving member 7 is also made of an elastic material like the sealing members 6a and 6b. 1
Reference numeral 0 denotes a support means for receiving the plate-shaped body 8 from a conveying means (not shown), and is equipped with a suction cup 11, to which negative pressure is supplied through a passage 12 bored in the backup plate 5. There is.

In addition, 13 is a spool for supplying molten resin into the mold, 14 is a gate, 15 is an ejector pin for discharging the product, 16 is an air vent hole, and 17 is for positioning the plate-shaped body 8 in the mold. The positioning pin 18 is a mounting member inserted into a edging member 19, which will be described later.

With such a configuration, in order to form the edges of the plate-shaped body 8, the plate-shaped body 8 is transferred from a conveyance means (not shown) onto the suction cup 11 of the support means 10 built into the movable mold 3 while the mold is open. Then, the movable mold 3 is raised and closed against the insert 1 by a drive means (not shown). During mold closing, the receiving member 7 first comes into contact with the plate-shaped body 8 and is bent, then the sealing members 6a and 6b of the fixed mold 1 and the movable mold 3 come into contact with the plate-shaped body 8 and are bent, and as the mold closes are completed. A cavity 9 is formed between the seal members 6a, 6b and the inner walls of the fixed mold 1 and the movable mold 3. After the mold is closed, the molten resin is injected into the cavity 9 at high pressure through the spool 13 and the gate 14, and the edging member 19 including the attachment member 18 is formed on the peripheral edge of the plate-shaped body 8. From then on, the mold is opened. When the ejector pin 15 is pushed up, the edging member 1 is removed.
9 can now be obtained.

(Problems to be Solved by the Invention) By the way, when resin is injected into the cavity 9, bending stress corresponding to the injection pressure is generated on the contact surfaces S1 and S2 of the seal members 6a and 6b with the resin. At this time, if the bending strength of the seal members 6a, 6b is small, gaps will be created between the seal members 6a, 6b and the mating surfaces of the fixed mold 1 and the movable mold 3, and as a result,
The occurrence of burrs may cause cracks in the insert 8 during mold release, or an additional burr removal process may be required after molding.

The occurrence of such burrs can be prevented by using seal members 6a and 6b with high bending strength. However, if seal members 6a and 6b with high bending strength are used, surface pressure increases when the mold is closed, and the plate If an unbalanced force is applied to the plate-shaped body 8, cracks will occur in the plate-shaped body.

(Means for Solving the Problems) The present invention was made to solve the above problems, and includes a plate-shaped insert inserted into the part facing the cavity and adjacent to the sealing member of fixed and movable types. The gist is that each protrusion is provided to form a gap of 0.5 to 1.0 mm between the body and the body.

Here, if the above-mentioned gap is less than 0.5 mm, for example, if the plate-shaped body has a three-dimensional curved surface like an automobile window glass, the plate-shaped body and the protrusion will interfere due to the dimensional variation. There is a risk
On the other hand, if the gap exceeds 1.0 mm, the injection pressure applied to the seal member becomes excessive and there is a risk that a gap may be created between the seal member and the fixed mold and movable mold. mm range.

(Function) In the edging molding device having the above configuration, when resin is injected into the cavity, the range of injection pressure applied to the sealing member is reduced as much as possible, and as a result, the sealing member and the fixed mold and movable mold are aligned. There are no gaps on the surface, and the occurrence of burrs is prevented.

(Example) Hereinafter, an example of the present invention will be described based on the accompanying drawings.

FIG. 1 shows the main structure of the edging forming apparatus according to the present invention. The overall structure is the same as that shown in Figures 2 and 3 above, so
The explanation thereof will be omitted here, and the same parts will be given the same reference numerals. The feature of this embodiment is that protrusions 21 and 22 are provided on the fixed mold 1 and the movable mold 3 at portions facing the cavity 9 and adjacent to the seal members 6a and 6b, respectively. These protrusions 21 and 22 are provided with appropriate gaps 21 between them and the plate-shaped body 8 inserted into the mold.
a, 22a, and the gap L is 0.5 to 1.0 mm.

With this configuration, the areas of the seal members 6a and 6b that receive injection pressure are narrowed as much as possible, and when resin is injected into the cavity 9, the seal members 6
Excessive injection pressure is no longer applied to a, 6b, preventing deformation of the seal members 6a, 6b, and as a result, gaps are created between the mating surfaces of the seal members 6a, 6b and the fixed mold 1 and movable mold 3. will no longer occur.

Note that the injection molding apparatus to which the present invention is applied is not limited to the one in the above embodiment, and can be applied to, for example, one omitting the receiving member 7 and the positioning pin 17, or one not including the mounting member 18. be.

(Effects of the invention) As explained above in detail, the present invention provides a protrusion that forms an appropriate gap between the plate-shaped body to be inserted and the part adjacent to the sealing member of the mold forming the cavity. Since the pressure-receiving area of the sealing member is reduced as much as possible, there is no gap between the sealing member and the mold during injection molding, and burrs can be prevented from occurring. Now I can do it. As a result, not only did the problem of the plate-shaped body cracking during demolding disappear, but the subsequent deburring process was no longer necessary, resulting in a significant reduction in product cost.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the main structure of the edging forming device according to the present invention, Fig. 2 is a sectional view showing the structure of the conventional edging forming device, and Fig. 3 is an enlarged sectional view of part A in Fig. 2. It is a diagram. 1... Fixed type, 3... Movable type, 6a, 6b...
Seal member, 8... plate-shaped body, 9... cavity,
21, 22... protrusion, 21a, 22a... gap.

Claims (1)

[Scope of utility model registration request] In an apparatus for inserting a plate-shaped body into a mating part of a fixed mold and a movable mold through a sealing member, making the peripheral edge part face the cavity, and forming an edging member on the peripheral part by injection molding, the fixed mold and A edging forming device characterized in that a movable part facing the cavity and adjacent to the sealing member is provided with protrusions that form a gap of 0.5 to 1.0 mm with the inserted plate-shaped body. .