JPH0529716U - Mold Ejector - Google Patents

Abstract

(57) [Summary] [Purpose] Even when the adhesive force between the mold surface and the molded product is strong, it is possible to reliably release the mold with air pressure. A seal member 9 is attached to a shaft portion 6 of a chip having a sealing portion 7 at an opening of an air supply passage 3 of a molding die to form an ejector chip, and the seal member of the ejector chip is provided in the air supply passage. Is installed so that it slides. The ejector tip is extruded by air pressure, and the ejecting force of the ejector tip directly acts on the molded product to separate the molded product from the mold surface. The ejecting force of the ejector tip is maintained until the sealing member opens the air supply passage, so that the molded product can be demolded without fail.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an ejector for a molding die that molds a resin molded product or the like.

[0002]

[Prior Art]

 Recently, FRP (glass fiber reinforced resin) products have come to be used for various molded products such as automobile outer panels. In the case of molding such a fiber-reinforced resin molded product, for example, in the case of an engine hood, in order to secure the rigidity, strength, etc. of the molded product, a plurality of reinforcing fibers such as glass fibers are layered in advance in a mat shape. Resin transfer molding (hereinafter referred to as RTM) is used in which the glass fiber mat is set in a mold and molten resin is injected into the mold for molding. In the mold used for RTM, as shown in FIG. 2A, a cavity is formed between the upper mold 1 and the lower mold 2, a reinforcing fiber mat is set in the cavity, and both molds are clamped and sealed. Then, the molten resin is injected from a resin injection port (not shown) provided in the upper mold 1 for molding. After molding, the mold is opened and the molded product is released from the upper mold 1. The upper mold 1 is provided with an air supply passage 3 which opens to the molding surface at several places, and compressed air is introduced into the molded product 4 to form the molded product 4. I try to get rid of the mold. Since the air supply passage 3 is directly open to the molding surface of the upper mold 1, in order to prevent the molten resin from entering during molding, conventionally, as shown in FIG. Adhesive tape 5 is attached.

In Japanese Utility Model Application Laid-Open No. 63-39519, a conical valve body-like stopper for opening and closing the vent hole and the outlet is provided, and the high pressure air from the outlet pushes up the molded body to release it. A molding die is described. In Japanese Utility Model Laid-Open No. 60-187024, an ejector pin of a die is provided with a piston which is moved by air pressure at a rear end thereof, and a passage for leaking air pressure to the die surface at a predetermined protruding position from the die surface. Is listed.

[0004]

[Problems to be solved by the device]

 If the conventional adhesive tape is used to block the opening of the air supply passage 3, the molded product will separate if the adhesive tape is peeled off by air pressure during demolding, leaving a small gap between the molded product and the mold surface. Before molding, air may escape from this gap and the mold release force necessary for mold release may not be generated and the ejector function may be lost. The releasing action of the releasing device described in the above-mentioned publication is that the ejector pin or the like protrudes into the forming die to introduce air between the die surface and the formed article, and the air pressure blown out by this is used. It exerts a mold release force and can be effectively released when the adhesive force between the mold surface and the molded product is relatively small. However, in molding by FRP RTM that uses a thermosetting resin, the mold surface and the molded product are Since the adhesive force with the product is large, as in the case where the adhesive tape is used, the air that should exert the releasing force escapes before the product is released from the product, so that the product cannot be released. Also, the amount of protrusion of the ejector pin etc. is structurally determined, and it is necessary to recreate the whole when trying to adjust the stroke.

The present invention solves the above-mentioned problems, and can accurately perform mold release even when the adhesive force between the mold surface and the molded product is large, and the stroke adjustment for mold release can be easily performed. The purpose is to provide an ejector.

[0006]

[Means for Solving the Problems]

 According to the present invention, an ejector chip is constructed by attaching a seal member to a shaft portion of a chip having a sealing portion at an opening of an air supply passage of a molding die, and a sealing member of the ejector chip is slid in the air supply passage. It is an ejector for a molding die that is installed so as to move.

[0007]

[Action]

 When an ejector chip is attached to the opening of each air supply passage before molding, the air supply passage opening is sealed by the ejector chip's sealing part. There is no risk of intrusion. After the molding, when compressed air is introduced into the air supply passage, the ejector tip is extruded by air pressure, and the ejecting force of the ejector tip directly acts on the molded product to separate the molded product from the mold surface. The ejecting force of the ejector tip is maintained until the sealing member opens the air supply passage, so that the molded product can be released from the mold without fail.

[0008]

【Example】

 In FIG. 1A showing a partial cross section of the molding die, a tip having a shaft portion 6 and a conical head portion 7 is formed by forming a conical seat surface 1a at the opening of the air supply passage 3 of the upper die 1. It is made of silicon resin, fluorine resin, polyacetal, or the like having good properties, and the shaft portion 6 is provided with an annular groove 8 in which a sealing O-ring 9 is fitted and attached in multiple stages in the axial direction. The O-ring 9 is made of a material having good sealing property and slidability such as silicon rubber, and is made to fit the inner diameter of the air supply passage 3. In the figure, the O-ring 9 is attached to the uppermost annular groove. is there.

When an ejector tip is attached to the opening of each air supply passage 3 of the upper mold 1 before molding and is molded, the opening of the air supply passage 3 has a conical seat surface 1a and a conical head 7 of the ejector tip. Since and are in contact with each other and sealed, there is no possibility that the resin will enter the air supply passage 3 when the resin is injected. When compressed air is introduced into the air supply passage 3 after molding, air pressure acts on the shaft portion 6 and the O-ring 9 to extrude the ejector chip, and the ejecting force of this ejector chip acts on the molded product 4 to form the molded product. Separate 4 from the mold surface. In the case of a flat molded product such as an FRP engine hood, when the ejector chip pushes out the molded product 4 a little, the other parts of the molded product 4 still remain in close contact with the mold surface and cannot be released. As shown in FIG. 1B, until the O-ring 9 of the ejector tip is opened to the conical seat surface 1a of the air supply passage 3, the air pressure acting on the ejector tip is maintained. Can be extruded and the molded product 4 can be demolded without fail. The stroke of this ejector tip can be easily adjusted by replacing the O-ring 9 with another annular groove 8.

FIG. 3 shows the structure of another ejector chip. In FIG. 3, the tip composed of the shaft portion 6 ′ and the conical head portion 7 is made of the same material as the ejector tip described above, and the seal 10 sliding in the air supply passage 3 is made of hard rubber and has a cup-shaped upper surface. Then, this is fitted and attached to the upper end of the shaft portion 6 '. In this ejector tip, the upper surface of the seal 10 is pressed against the inner surface of the air supply passage 3 by receiving the air pressure, so that there is no air leakage and the ejection of the ejector tip is not reduced. Also in this embodiment, the stroke of the ejector tip can be adjusted by separately preparing a seal 10 having a different height H and replacing it with the shaft portion 6 '.

The structure of another ejector tip will be described with reference to FIG. Reference numeral 11 in FIG. 4A is a cylindrical sealing body made of a material having a good sealing property and slidability such as silicon rubber. A vertical groove 12 is formed in the sealing body 6 of the same chip as in the previous embodiment. 4B, in this structure, when the ejector tip is extruded by air pressure and the lower end 13 of the vertical groove 12 is opened to the conical seat surface 1a of the air supply passage 3, as shown in FIG. The air in the air passage 3 escapes, and the ejector tip stops at that position. In this state, the outer surface of the seal body 11 is still fitted to the air passage 3, so the ejector tip falls out of the air passage 3. Therefore, the next molding can be performed by simply pushing the ejector tip into the air supply passage 3 after releasing the mold. Also in this embodiment, the longitudinal groove 12 of the seal body 11 having a different length L is used. Separately, the shank ” The stroke of the ejector tip can be adjusted by changing to 6.

Although the FRP RTM molding has been described above, the ejector tip of the present invention can be applied to other low-pressure molding dies, and air pressure can be directly applied to a molded product as in the conventional case. Instead, the present invention pushes the molded product with an ejector tip that holds air pressure for a predetermined stroke, so that the mold release can be reliably performed.

[0013]

[Effect of the device]

 According to the present invention, the molded product can be reliably released from the mold even when the adhesive force between the mold surface and the molded product is large, and the stroke of the ejector tip can be easily adjusted.

[Brief description of drawings]

FIG. 1 is an explanatory view of an operating state of an embodiment of the present invention.

FIG. 2 is an explanatory view of a molding die to which the present invention is applied.

FIG. 3 is a partial cross-sectional view of another embodiment of the present invention.

FIG. 4 is an explanatory view of another embodiment of the present invention.

[Explanation of symbols]

1 Upper mold 2 Lower mold 3 Air supply passage 4 Molded product 6 Shaft part 7 Cone head 8 Annular groove 9 O-ring 10 Seal 11 Seal body

Claims (1)

[Scope of utility model registration request] 1. A ejector chip is constructed by attaching a seal member to a shaft portion of a chip having a sealing portion of an opening of an air supply passage of a molding die, and the seal member of the ejector chip slides in the air supply passage. A molding die ejector characterized by being installed so as to move.