JPS60157820A - Injection mold - Google Patents

Abstract

PURPOSE:To obtain a lightweight injection mold of a few parts capable of a forming a resin part having an undercut section such as a car bumper etc. by restraining inclined cores and a movable mold independently from each other. CONSTITUTION:The cavity 5 of the formed item 6 comprises the movable mold 3 beneath a fixed mold 2, the inclined cores 4, 4 inclining in the fanwise shape on both sides of the movable mold and the partial die inserts 8, 8 equipped together with both inclined cores 4, 4 and the partial liners 8, 8 form the undercut section 7 of the formed item 6. A movable fitting plate 14 is equipped under the movable mold 3 through a spacer block 13 so that the partial liners 8, 8 are fixed with bolts 15, 15. Between the movable mold 3 and the movable fitting plate 14 is provided the push plate 10' lifted by the push rod 16 piercing the movable fitting plate 14. The lower part of each inclined core 4 is fixed as if it strides the end of the plate 10'. Further, the L-type terminal pieces 23, 23 installed on the movable mold 3 through the bolt 22 are fitted on both sides of the inclined core that can slide freely on the movable mold 3 to restrain the inclined core 4 independently from the movable mold 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical field/field> The disclosed technology belongs to the technical field of injection molding used for molding bumpers and the like of vehicles.

<Explanation of the gist> Accordingly, in the present invention, a movable mold is provided opposite to a fixed mold forming a cavity, an inclined core is slidably provided on the outside of the movable mold, and a The undercut part of the molded product is formed by the attached partial insert,
The invention relates to an injection mold in which a tilted core is movable up and down via an extrusion body provided below the movable part,
In particular, the inclined core and the movable mold are constrained to separate from each other,
An injection mold in which the lower part of the inclined core is slidable in the longitudinal direction of the extruded body relative to the extruded body, and the inclined core, which is raised by the extruded body, can be moved smoothly toward the inside of the extruded body. This is such an invention.

<Prior Art> As is well known, for resin products, especially molded products having undercut parts such as vehicle bumpers, an injection mold 1 as shown in Fig. 1.2 is used for cutting the mold. There are many cases where

That is, with respect to the fixed mold 2 installed at the upper part, the movable mold 3 installed at the lower part and the inclined cores 4 provided on both sides of the movable mold 3 are raised and lowered, and the keys 17 and 5 are used. The molded product 6 is injection molded, and the uncut portion 7 of the molded product 6 is processed by a partial insert 8 provided g1 on the inclined core 4.

<Problems with the prior art> However, in the conventional injection mold 1 described above, the back-up plate 9 is required to receive the inclined core 4, which increases the thickness of the mold and increases the weight. was there.

In addition, when the inclined core 4 is to be lifted up by the extrusion plate 10 as an extrusion body provided below the movable mold 3 in order to remove the molded product 6, since the backup plate 9 is provided, the inclined core 4 can be directly removed. There is a disadvantage that the core 4 cannot be pressed and the extrusion rod 11 etc. must be used to intervene, which increases the number of parts and complicates the structure7j0.In addition, the increase in the number of parts also has the disadvantage of increasing costs. Ta.

<Objective of the Invention> The object of the present invention is to solve the problems of the injection molding mold based on the prior art described above, and to achieve the same reliability as the conventional one while reducing the number of parts and reducing the weight of the entire mold. It is an object of the present invention to provide an excellent injection mold that can maintain the same performance and that is beneficial to the field of mold utilization in the parts manufacturing industry.

<Structure of the Invention> In accordance with the above-mentioned object, the structure of the present invention, which is summarized in the above-mentioned claims, is such that, in order to solve the above-mentioned problems, a movable type and a tilted core are raised to a predetermined value with respect to a fixed type. After molding a molded product by forming a cavity and supplying a resin material into the cavity, the movable mold etc. is lowered, contrary to the above, and the extrusion body provided below the movable mold is raised. As the extrusion bottle in the mold presses the molded product, the inclined core whose lower part engages with the extrusion body is directly pressed and rises while securely sliding against the movable mold while being restrained in a dissociative manner. , the molded product is separated from the movable mold, and during this time, the inclined cores tilt upward to smoothly slide the extruded body inward, and the molded product is separated from the movable mold by each tilted core. The undercut section is a technical measure that allows the inclined core to move inside the extrusion and thereby be separated from the partial insert attached to the inclined core.

<Embodiment - Configuration> Next, one embodiment of the present invention will be described based on the drawings from FIG. 3 onwards. Note that the same parts as those in the conventional mode shown in FIG. 1.2 will be explained using the same reference numerals.

What is shown in FIG. 3 is an injection mold 1' that constitutes the gist of the present invention. Below a fixed mold 2 having a fixed mold mounting plate 12, a movable mold 3 and a V-shaped mold on both sides thereof. A tilted core 4.4 and, furthermore, a partial insert 8 associated with each tilted core 4 are provided.

Then, the fixed mold 2, the movable mold 3, and the inclined core 4.4
, and the partial insert 8 form the cavity 5 of the molded product 6.
is formed, and the partial insert 8 forms an undercut portion 7 of the molded product 6.

A movable mounting plate 14 is provided on the lower side of the movable mold 3 via a spacing block 13, and the partial insert 8.8 is fixed to the movable mounting plate 14 with bolts 15, 15, . . . .

Between the movable mold 3 and the movable mounting plate 14, an extrusion plate 10' as an extrusion body that is raised and lowered by an extrusion rod 16 and 16 passing through the movable mounting plate 14 is connected to the upper plate 17 by bolts 24.
It is fixedly provided by.

The extrusion plate 10' has a compression spring 18, 18 in its center.
is interposed between the movable mold 3 and an extrusion bottle 19 having a length that is flush with the surface of the movable mold 3 at the time of mold clamping on its upper surface.
．． 19... are fixed, and the inclined core 4 is fixed at both ends thereof.
．． The lower part of 4 is engaged.

In addition, the elastic force P of the compression spring 18 is (the weight of the weight gradient core 4.4 of the upper plate 17 and the extrusion plate 10') x frictional resistance = W
is set to a value greater than .

As shown in FIG. 4, the lower part of the inclined core 4 is formed so as to straddle the end of the extruded plate 10', and the plate 1-21 is attached to the bolt 20, 20 on the lower surface of the extruded plate 10'. The core 4 is fixed at an inclined position with respect to the longitudinal direction of the extrusion plate 10'.
and plate 21 can slide freely and smoothly.

Furthermore, as shown in FIG. 5, on both sides of the inclined core 4 slidably mounted on the movable mold 3, there are L-shaped hooks provided on the movable mold 3 via bolts 22 and 22. Stoppers 23 and 23 are latched to the movable die 3 to restrain the inclined core 4 from separating.

<Embodiment - Effect> In the above-mentioned configuration, as shown in FIG. After being lowered, when removing the movable mold 3 and the molded product 6 with the inclined core 4.40, the extrusion plate 10' is first pushed up by the extrusion L1 rod 16.16.

As a result, the movable mold 3 is directly pressed against the extrusion &10'.
The molded product 6 is pushed up and separated from the movable mold 3 by the extrusion pins 19 and 19, and each inclined core 4 is moved inwardly toward the molded product. Due to the close proximity to the undercut 7 of the molded part 6, the movable mounting plate 14, which remains on the underside, is released from the insert 8 and the inclined core 4.4, and the molded part 6 is in the state shown in FIG. removed.

Since the inclined cores 4.4 are engaged with the movable die 3 so as to be able to slide freely on the surface while being constrained to separate from each other, the extrusion plate 10
In combination with the fact that it is directly pressed by ', it is possible to rise reliably.

In addition, as the inclined cores 4.4 move closer to each other as they rise, they can freely slide relative to the end of the extrusion plate 10', allowing for smooth operation similar to the upward movement of the movable mold 3 mentioned above. It is done.

Then, the extrusion plate 10' is pressed by the compression spring 18.18.
, and after the upper plate 17 is returned to the initial let position, the movable mold 3 and the like are again clamped against the fixed mold 2, and the molded product 6 is sequentially molded.
Index molding.

<Other Embodiments> It goes without saying that the embodiments of the present invention are not limited to the above-mentioned embodiments; for example, it is possible to employ other embodiments in which the inclined core is fitted to the movable mold. .

<Effects of the Invention> As described above, according to the present invention, when injection molding a molded product having an undercut portion, the undercut portion treatment after mold clamping and mold opening can be performed smoothly and reliably. Excellent effects are produced.

Further, since the inclined core and the movable mold are restrained from being separated from each other, an excellent effect is achieved in that the inclined core suppressed from below can smoothly rise along the movable core.

Furthermore, since the lower part of the inclined core is slidably locked in the longitudinal direction of the extrusion plate, the inclined core can be raised directly by the extrusion holder, which is different from conventional injection molding molds using extrusion rods. In comparison, the number of parts and the mold thickness can be reduced, and the overall effect can be made compact, and the sliding movement of the inclined core toward the inside of the extruded body can also be smoothly performed. .

In addition, there is a secondary benefit in that the entire mold can be made into a single mold, reducing the cost of amulets and other costs. .

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view of a conventional injection mold, Fig. 2 is a partially enlarged view of Fig. 1, Fig. 3 and the following show examples of this invention, and Fig. 3 shows the entire injection mold. Cross-sectional view, Figure 4 is the 3rd
Figure IV-IV sectional view, Figure 5 is Figure 3 V-■ sectional view,
FIG. 6 is a partial sectional view when removing the molded product. 2...Fixed type, 3...Movable type,

Claims (1)

[Claims] A tilted core is slidably installed on the outside of the movable mold facing the fixed mold, and a partial insert attached to the tilted core forms an undercut portion of the molded product, and an extrusion section is formed below the movable mold. In an injection mold in which a tilted core is movable up and down through a body, the tilted molds are constrained to separate from each other and are slidably engaged with each other, and the tilted core is movable up and down through the body. An injection molding die characterized in that a lower part of the core is slidably locked in the longitudinal direction of the extruded body.