1. Field of the Invention
The present invention generally relates to an injection mold, and more particularly to an injection mold capable of ejecting a product out effectively.
2. The Related Art
Generally, a conventional injection mold for molding a product which has a barb at a bottom of the product includes a stationary mold and a movable mold. The movable mold includes a movable plate, a movable core mounted in a middle of a top of the movable plate, a sliding block mounted on one side of the movable plate, and a plurality of ejector pins inserted in the movable mold and penetrating through the movable core. When the injection mold is closed, a shaping cavity for molding the product is formed among the stationary mold, the movable core and the sliding block. When the injection mold is opened, the ejector pins move upward to eject the product out of the injection mold. Then the barb of the product is further parted from the sliding block by means of moving the sliding block upward and sideward by other complex auxiliary jigs. However, there is no refraction area between the barb of the product and the movable core, so the product is apt to cause a deformation under a strong traction of the auxiliary jigs. Furthermore, the sliding block occupies a larger area in the injection mold along a vertical direction and a horizontal direction, so a large space is occupied by the injection mold to increase manufacturing cost of the injection mold. The complex auxiliary jigs are needed to part the product from the sliding block that increases the cost of manufacturing the product. As a result, production efficiency of the injection mold is lowered.
An object of the present invention is to provide an injection mold for molding a product having a barb at a bottom thereof. The injection mold includes a stationary mold, a movable mold, an ejector pin and a sliding mechanism. The stationary mold defines a sprue channel. A bottom of the stationary mold is concaved upward to form a groove. The movable mold is positioned under the stationary mold when the injection mold is closed. The movable mold includes a movable core which has a top thereof received in the groove of the stationary mold and spaced from an inner periphery of the groove to define a base groove therebetween. The ejector pin is movably inserted in the movable mold for ejecting the product out of the injection mold. The sliding mechanism includes a sliding block movably mounted on a top of the movable mold and adjacent to one side of the movable core, a spring contracted between the sliding block and the movable mold, and a locating element vertically inserted in the spring through the sliding block. A top of the sliding block abuts against the bottom of the stationary mold to together define a receiving cavity therebetween. A bottom end of the locating element is fastened to the movable mold and a top end thereof stretches in the receiving cavity. A corner of the sliding block adjacent to the movable core defines a nick connected with the base groove for molding the barb of the product. The nick cooperates with the base groove to together define a shaping cavity for molding the product. When the injection mold is opened, the sliding block moves upward under the bounce thrust of the spring and the guide of the locating element along the one side of the movable core to make the product parted from the top of the movable core. The top end of the locating element can resist against a bottom side of the receiving cavity to block the sliding block overly moving upward. An elastic refraction area is accordingly formed between the product and the movable core for assisting the ejector pins to eject the barb out of the sliding block.
As described above, when the injection mold is opened, the ejector pin moves upward to push a bottom of the product upward to make the barb of the product parted from the sliding block. The barb can be retracted towards the movable core through the elastic retraction area, so the barb is able to be parted from the sliding block directly without any deformation. Therefore, the product can be ejected out of the movable mold effectively to ensure a production of the product. Furthermore, the sliding block is driven to vertically move upward and downward along the side surface of the movable core under the cooperation of the locating element and the spring, so the sliding block occupies a smaller area in the injection mold to make the injection mold occupy a smaller area. So cost of manufacturing the injection mold is decreased, and production efficiency of the injection mold is improved.
The present invention will be apparent to those skilled in the art by reading the following description, with reference to the attached drawings, in which:
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As described above, when the injection mold 1 is opened, the fixing plate drives the ejector pin 14 to move upward along the ejector pin hole 121 to push a bottom of the base portion 81 of the product 80 upward to make the barb 83 of the product 80 parted from the sliding block 15. The barb 83 can be refracted towards the movable core 12 through the elastic retraction area 40, so the barb 83 is able to be parted from the sliding block 15 directly without any deformation. Therefore, the product 80 can be ejected out of the movable mold 10 effectively to ensure a production of the product 80. Furthermore, the sliding block 15 is driven to vertically move upward and downward along the side surface of the movable core 12 under the cooperation of the locating element 16 and the spring 17, so the sliding block 15 occupies a smaller area in the injection mold 1 to make the injection mold 1 occupy a smaller area. So cost of manufacturing the injection mold 1 is decreased, and production efficiency of the injection mold 1 is improved.
The forgoing description of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. Such as other embodiments, in which the spring 17 is just assembled to the movable plate 11 or the sliding block 15, the receiving cavity 151 is only opened in the bottom of the stationary mold 20 or opened between the top of the sliding block 15 and the bottom of the stationary mold 20. Such modifications and variations that may be apparent to those skilled in the art are intended to be included within the scope of this invention as defined by the accompanying claims.