JPS62156918A - Molding method for bottomed cylindrical product having protrusion extending over almost whole circumference of inner surface - Google Patents

Abstract

PURPOSE:To enable injection molding of a bottomed cylindrical product having a protrusion on the inner surface extending over almost whole the circumference of the same as a single article through one time molding work, by combining a number of slide cores possessing a parting surface in the direction of mold break on the external circumference of a male mold. CONSTITUTION:As the core part 1' of a male mold 1 is divided into a number of parts as a combination of a first slide core 2 and second slide core 3, when the first slide cores 2..., to begin with, and then the second slide cores 3... are made to pucker inward after a mold has been broken by sticking a bottomed cylindrical product A which is a molded article to the male mold 1, the diameter of the core part 1' is reduced smoothly as a whole. In this instance, as the first and second slide cores 2, 3 and the product A do not generate relative slide among them, the first and second slide cores 2, 3 are separated respectively from the inner surface (b) and a protrusion (d) of the product A reliably. Therefore, it is possible to separate both the first and second slide cores 2, 3 completely from the protrusion (d) through a device from the view point of design based on sliding quantities of the first and second slide cores 2, 3 and each of slide tilting angles theta1, theta2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention has a protrusion on the inner surface that covers almost the entire circumference, so that it can only be removed by shrinking the male core so that its diameter is reduced as a whole. Regarding the method of integrally molding a bottomed cylindrical product such as a paint can, which cannot be molded, as an injection molded product of synthetic resin, the core part of the male mold is molded as the mold opens. The present invention relates to a molding method that allows the molded product to be easily and accurately deflated to the required extent and removed from the mold using purely mechanical means.

Conventional technology For example, as can be clearly seen in Fig. 6, a mouth rim has a groove a for fitting a lid over the entire circumference, and in order to form this groove a, a bulge C is formed over the entire inner surface. Therefore, let's mold a bottomed cylindrical product (container) A, such as a paint can, as an injection molded product of synthetic resin, having a protrusion d that is oriented substantially perpendicular to the demolding direction (mold opening direction). In this case, no practical method or means for demolding the protrusion d has conventionally been found.

Therefore, for the time being, the main body part B of the bottomed cylindrical product A,
The lip portion C including the protrusion d is separately injection molded, and then the circular portions B and C are integrated by welding or other methods (for example, see Utility Model Application No. 58-24743). Paint cans listed).

Problems to be Solved by the Invention As in the prior art described above, injection molding is performed in two parts B and C,
According to the manufacturing method that is then integrated, of course two types of molding molds are required, and two molding operations are required.
Furthermore, since joining work is required for integration, a large number of man-hours and time are required, and the manufacturing price becomes high. In addition, inventory management of each molded component is troublesome.

Therefore, the object of the present invention is to provide a bottomed cylindrical product A (provided that a bottomed cylindrical product A has a protrusion d extending almost all around the inner surface).

To provide a molding method capable of injection molding a bottom (including cases where the bottom is completely closed, a case where the bottom is half-open or a bottom with a protrusion extending over almost the entire circumference) as a single product in one molding operation. be.

Means for Solving the Problems As a means for solving the problems of the prior art described above, a method for molding a bottomed cylindrical product having a protrusion on the inner surface extending almost all around the circumference according to the present invention is described in the drawings. As shown in the example, (a) the core part 1' of the male mold 1 forming the bottomed cylindrical product A having the protrusion d extending almost all around the inner surface is located inside the bottomed cylindrical product A; The entire circumference of the side surface is divided into several parts, and a first slide core 2 and a second slide core 3 each having a dividing surface in the mold opening direction are combined side by side.

(b) Then, the step of attaching the molded bottomed cylindrical product A to the male mold 1 and opening the female mold 4 and the male mold 1; Then, the second slide core 3 is also similarly contracted inward by the protruding plate 5 to form a bottomed cylindrical product A.
(d) Then, the step of projecting the bottomed cylindrical product A from the male mold 1.

As a means for inwardly retracting the first slide core 2, the first slide core 2 is provided so as to be slidable along the taper of the tapered conical main core 6, and the first slide core 2 is attached to a protruding plate. 5 to make it deflate inward by sliding it forward. Specifically, the main core 6 and the first slide core 2 are slid together via a dovetail guide 10.

Further, as a means for inwardly deflating the second slide core 3, the first slide core 2 and the second slide core 3 are combined so that they can only slide inward and outward (direction perpendicular to the mold opening direction). The second slide core 3 is slid inward by the protruding plate 5 along the inclined bin 7 having an inclination angle θ2 smaller than the slide angle θ1 of the first slide core 2. More specifically, the first slide core 2 and the second slide core 3 are moved inward and outward by a sliding key 8 that is oriented perpendicular to the mold opening direction, that is, perpendicular to the inner surface of the product A. Only slides are possible in combination.

Function: The core part 1' of the male mold 1 is divided into many parts as a combination of the first slide core 2 and the second slide core 3. After opening the mold, the first slide core 2... and then the second slide core 3... are shrunk inward, and the diameter of the core portion 1' as a whole becomes smaller. Smoothly downsized.

At this time, since the first and second slide cores 2 and 3 and the product A do not cause relative sliding, the first and second slide cores 2 and 3 are securely moved from the inner surface and the protrusion d of the product A, respectively. to leave.

Therefore, by a design method based on the sliding amount of the first and second slide cores 2 and 3 and their respective slide inclination angles θ1 and θ2, it is possible to completely separate them from the protrusion d, so that the inner It is possible to form a bottomed cylindrical product A having a protrusion d extending all around the side surface.

When the first and second slide cores 2 and 3 have completely separated from the protrusion d, the product A is ejected from the male mold 1 and the molding process is completed, and mold clamping can be smoothly performed by performing the exact opposite operation. .

Example Next, a preferred embodiment of the invention illustrated in the drawings will be described.

First, Figure 1 shows the clamped male mold 1 and female mold 4.
FIG. 2 shows a stage in which the molten resin filling process for product A was carried out, and FIG. 2 shows a stage in which the male mold 1 and the female mold 4 were opened after cooling time. At this time, the product A, which is a molded product, is attached to the male mold 1 because it has the protrusion d.

Next, FIGS. 4 and 5 show a stage where the first slide core 2 constituting the core portion 1' of the male mold 1 has started its narrowing operation.

That is, as is clear from FIGS. 4 and 5, the core portion 1' of the male mold 1 is formed of a main core 6 having a tapered pyramidal shape (however, the shape is not limited to a pyramidal shape) provided in a core frame 9. A first slide core 2 and a second slide core each having a dividing surface (sliding surface) parallel to the mold opening direction by dividing the inner circumference of the product A into eight (however, the number of divisions is not limited to this) on the outer periphery. The slide cores 3... are arranged in combination next to each other.

More specifically, as shown in FIG. 5, the first slide core 2 has a substantially trapezoidal cross section that narrows outward in the radial direction, and is connected to the main core 6 by a dovetail guide 10. There is. Therefore, this first slide core 2 is forcibly slid along the taper (inclination angle θ1=FIG. 3) of the main core 6.

Each slide core 2 has an i-tie rod 1 parallel to the mold opening direction.
1 is connected to the protruding plate 5.

However, the connecting rod 11 is attached to the protruding plate 5 so that it can be displaced by the amount of the first slide core 2's narrowing movement. Reference numeral 12 in the figure indicates a protruding rod of the protruding plate 5.

Therefore, while the male mold 1 is performing a mold opening operation to the left in the figure, the first slide core 2 starts to narrow from the moment the protruding plate 5 starts moving forward to the right in the figure. .

That is, as the protruding plate 5 moves forward in the right direction in the figure,
The first slide core 2, which is integrally connected to the protruding plate 5 by the connecting rod 11, slides rightward. At this time, the first and second slide cores 3 . Since the slide is performed along the tapered edge of the
In other words, a narrowing motion occurs and the product A separates from the inner surface (FIGS. 4 and 5). As shown in FIG. 5, the cross-sectional shape of the first slide core 2 has a substantially trapezoidal shape that becomes narrower toward the outside in the radial direction, and since this is combined with the adjacent second slide core 3, 1. There is no hindrance to the narrowing operation of the slide core 2 at all.

Further, a little later than the first sliding core 2's closing operation, the second sliding core 3's closing operation also starts.

This is because the second slide core 3 is connected to the first slide core 2 via the slide key 8 that is oriented perpendicular to the mold opening direction (slide direction). Further, one end of the tilting bin 7 is fixed to the rear end of the second slide core 3, and the other end can be displaced inwardly and outwardly with respect to the protrusion plate 5 necessary for the narrowing movement of the second slide core 3. Possibly connected.

The inclined pin 7 is passed through the inclined hole 15 of the core frame 9. Incidentally, the inclination angle θ2 of the inclination pin 7 is smaller than the inclination angle θ1 of the taper of the main core 6 mentioned above, that is, the dovetail groove guide IO.

Therefore, when the first slide core 2 starts moving forward in the right direction in the figure by the protruding plate 5 as described above, the inclined pin 7 is also connected to the protruding plate 5, and the first sliding core 2 is connected to the protruding plate 5 via the sliding key 8. The second slide cores 3, which are directly connected to each other, also move forward rightward as a unit.

As a result, the second slide core 3 is displaced toward the center (inward) in proportion to the inclination angle θ2 defined by the inclination pin 7 and its sliding surface 15 and the amount of slide, that is, inwardly deflects. This causes a jamming motion.

However, due to the relationship 0 (>02), the narrowing motion of the second slide core 3 occurs slightly later than the narrowing motion of the first slide core 2.

Next, FIG. This shows a stage in which the second slide core 2.degree. 3 has progressed in its narrowing motion and both have completely separated from the protrusion d of the product A, which is a molded article. 1st, 2nd
Sliding amount of slide cores 2 and 3 and respective inclination angle θ1
．． 02, it is easily possible to completely separate both from the protrusion d using a design method.

The stripper plate 13 also includes the protruding plate 5 and the continuous rod 1.
6, and is slid by a protruding plate 5.

In this way, the first. After the second slide cores 2 and 3 are completely separated from the protrusion d of the product A, the product A is dropped by a protruding bottle (not shown), and the mold opening process is completed. Mold closing and mold clamping processes are performed.

The effects of the invention are as described in detail in conjunction with the embodiments, and the method of molding a bottomed cylindrical product A having a protrusion on the inner surface extending almost all around the circumference has achieved effects that were previously extremely difficult. The bottomed cylindrical product A can be integrally molded using a single molding die in a single molding operation.

Therefore, it can be efficiently manufactured with a minimum number of man-hours and can be made at low cost.

Moreover, since this is a molding method that relies entirely on purely mechanical means and nine steps, the structure of the molding machine.

The control method can be significantly simplified.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a molding die in a closed state for carrying out the molding method of the present invention, FIG. 2 is a cross-sectional view of the mold in an open state, and FIG. 4 is a sectional view showing the initial sliding stage of the first slide core, FIG. 5 is a half sectional view taken along arrow v-■ in FIG. 4, and FIG. 1st. Figure 7 is a cross-sectional view of the stage where the second slide core has completely separated from the protrusion of the product.
−■ It is a half sectional view in the direction of the arrow.

Claims (1)

[Scope of Claims] [1] (A) The core portion (1') of the male mold (1) forming the bottomed cylindrical product (A) having a protrusion (d) extending almost over the entire circumference on the inner surface is: A structure in which the entire circumference of the inner surface of the bottomed cylindrical product (A) is divided into several parts, and a first slide core (2) and a second slide core (3) each having a dividing surface in the mold opening direction are combined side by side. (b) attaching the molded bottomed cylindrical product (A) to the male die (1) and opening the female die (4) and the male die (1); (c) the protruding plate (5); ) to first slide the first slide core (2
) inward, and then remove the second slide core (3).
the same projecting plate (5) and causing each to separate inwardly from the protrusion (d) of the bottomed cylindrical product (A); (d) then, the bottomed cylindrical product ( A method for forming a bottomed cylindrical product having a protrusion extending almost all the way around the inner surface thereof, the method comprising the steps of: A) protruding from a male die (1); [2] As a means for inwardly retracting the first slide core (2) described in claim 1, the first slide core (2) is adapted to the taper of the tapered conical main core (6). The inner surface has a protrusion extending almost all the way around, the first slide core (2) being slid inward by sliding the first slide core (2) forward with a protruding plate (5). A method for forming a bottomed cylindrical product. [3] As a means for inwardly deflating the second slide core (3) described in claim 1, the first slide core (2) and the second slide core (3) are moved inwardly and outwardly. The second slide core (3) is moved by the protruding plate (5) along the inclined pin (7) with an inclination angle (θ_2) smaller than the slide angle (θ_1) of the first slide core (2). A method for forming a bottomed cylindrical product having a protrusion extending almost all the way around the inner surface, the product being slid and retracted inward.