JPH01151403A - Method for manufacturing bag of sunthetic resin - Google Patents

Abstract

PURPOSE: To make a draft of an outer circumferential surface of a frame-shaped part inconspicuous by a method wherein a cavity and a core of a die are manufactured for injection molding of a half body and a half body linked by a link piece and a rising or setting slide core is arranged on a plane part of the frame-shaped part to perform an injection molding. CONSTITUTION: A cavity and a core of a die are manufactured for injection molding of a half body 1a and a half body 1b linked by a freely bendable link piece 3. Rising or setting slide cores 4 and 4 are arranged on a die structure surface and at a plane part other than a part corresponding to a corner part and the half body part 2a of a frame-shaped part 11 at the right angle to the direction of dividing the die. An end face 41 of the surface side of a product is built on a plane parallel with the direction of dividing the die and with the width thereof set smaller than the width of the part 11, the end face 41 is positioned at an intermediate point across the width of the part 11 and the end faces 41 and 41 are made to slightly stick out of the surface of the cavity corresponding to the part 11 to perform an injection molding. The part 11 is molded flat in the surface thereof and at a specified range except for the portions of the corner part and the half body part 2a. Thus, the area of the plane part is large so that the draft exerts no influence on the appearance.

Description

[Detailed Description of the Invention] [Field of Application] The present invention relates to a method for manufacturing a bag made of synthetic resin, and in particular a method for manufacturing a bag such as an attache case having a rigid exterior plate. In a type of bag in which the bodies fit together at their open ends, the outer surfaces of the frame-shaped parts at the open ends of the halves are not inclined, but are parallel to each other over substantially the entire area, parallel to the direction in which the halves are opened. The objective is to create an appearance that consists of flat planes. In addition, as a method for this purpose, by devising the mold structure during injection molding, it is possible to mold the product into the above-mentioned form at the end of injection molding.

[American technology and its problems] Attaché cases are widely used as business bags because their exterior parts have sufficient rigidity, so that the contents are sufficiently protected against impact forces.

This type of bag is constructed from a combination of metal plates and synthetic resin molded products, but it is designed to be easy to use, such as by being equipped with two pockets inside, so it is easier to use than a simple bag. It is expensive.

From the viewpoint of protection against impact, it is also possible to manufacture the entire structure by injection molding of synthetic resin, as shown in FIG. One handle (2) is made in this way.
Since the halves (1a) and (1b) of the dish-shaped main body including the can be manufactured simultaneously and integrally by injection molding,
Upon completion of injection molding, a bag similar to a so-called attache case is completed. Therefore, this type of bag can be manufactured at low cost.

However, bags manufactured using this method have an unsightly appearance.

This is because in injection molding molds, it is necessary to take into account the drafting slope (a slope that is provided to take out the product from the mold after injection molding and is inclined in the direction of taking out the product), and the half body ( In the case of the method of manufacturing 1a) and (Ib), as shown in FIG. In the completed state, the surface of the frame-shaped part (11) with this slope will appear as it is, and the inclined surface will continue to the surface of the frame-shaped part (11), making it look like a normal attache case. This is because, when compared to

[Technical fR problem] The present invention provides a frame-shaped portion (1
1); a half body (1a) having an open end and having an open end that fits into the frame portion (11) and being substantially symmetrical to the half body (1a); In method J for manufacturing a synthetic resin bag, the lower sides of the bag (Ib) are connected to each other in a flexible manner by a connecting piece (3), and the whole is integrally molded by injection molding of synthetic resin. In order to make the outer circumferential surface of the east joining part of the open ends of 1a) and the half body (Ib) similar to the conventional attache case, the draft angle of the outer circumferential surface of the frame-shaped part (11) is made conspicuous. The technical challenge is to prevent this from occurring.

[Technical Means] The technical means of the present invention taken in order to solve the above technical problem is ``Half part (2a) of the handle (2) on one side of the open end.
A half body (1a) in which the two halves are connected in one body, and a half body (2b) in which the other half (2b) of the handle (2) is similarly connected at a symmetrical position of the half body (1a) on one side of the open end. 1b) are arranged side by side so that the constituent planes of their open edges are parallel to each other, and the half body (
1a) and the half body (1b) are connected to each other by a connecting piece (3
) In order to perform injection molding in a connected state, a cavity and a core of an injection mold are manufactured, and the mold forming surface corresponds to the outer surface of the frame-shaped part (11) on the cavity side, and the frame-shaped part (11) Slide cores (4), (4) that can be retracted and retracted in a direction perpendicular to the mold dividing direction are disposed on the plane part other than the corner part and the part corresponding to the half body part (2a). The end surfaces (41) on the product surface side of the slide cores (4), (4) are configured to be planes parallel to the dividing direction of the mold, and the width of the end surfaces (41) is set to be smaller than the width of the frame portion (11). is also set small, the end surface (41) is located in the middle of the width direction of the frame-shaped part (11), and the end faces (41) and (41) are set to be small in the cavity f corresponding to the frame-shaped part (11). It was made to protrude slightly from the surface and injection molded using a mold having the above configuration.

[Effect]

The above technical means of the present invention operates as follows.

According to the method of the present invention, when injection molding is performed using an injection mold, the mold includes halves (1a), (1
b) and the half parts (2a), (2b) and further the connecting piece (
Since the parts corresponding to 3) are included, a synthetic resin bag is completed.

Particularly, regarding the frame-shaped part (11) of the half-body (1a), the mold has a part corresponding to the frame-shaped part (11) other than part of the corner and half-body part (2a). There are slide cores (4), (4), and an end face (41).

(41) is in a slightly protruding state within the cavity, so in the above-mentioned completed state, a predetermined area on the surface of the frame-shaped part (11) other than the corner part and the half part (2a) is flat. This plane is parallel to the opening/closing direction of the bag.

Therefore, although the parts other than those corresponding to the end faces (41) and (41) are finished with a sloped part required for injection molding, the area of the flat part is that of the sloped part. Since it is extremely larger than , the gradient loses its controlling power in appearance.

〔effect〕

Since the present invention has the above configuration, it has the following unique effects.

On the surface of the frame-shaped part (11), as well as the corner part and the half part (2a)
) is molded into a flat surface, and this flat surface is parallel to the opening and closing direction of the bag. Since the area is extremely larger than the area of the part where the area is, the slope has no controlling power in terms of appearance. Therefore,
What if the maximum outer periphery of the bag in its completed state is composed of a plane parallel to the opening direction of the bag? 'i, etc., and the inconvenience of the so-called loose appearance as in the past can be prevented.

[Example] An example of the present invention will be described below with reference to FIGS. 1 to 11.

The bag produced according to this embodiment has a structure as shown in FIGS. 1 to 7, with a half body (1a) and a half body (2a).
However, the half body portions (2b) are each formed into a body shape in the half body (1b), and the outer shape of each half body (1a) and (1b) is approximately rectangular. And halves (1a) and (1b)
The lower sides of the two are connected to each other by a connecting piece (3).

This connecting piece (3) has a thin wall and is flexible.

Next, a frame-shaped part (11) is formed at the open end of the half-body (1a), and both ends of the half-body part (2d) are continuous with the frame-shaped part (11). It becomes. The surface of this frame-shaped part (11) has a first recessed part (
12), (12) has a second concave x (13
), (13) are formed, and this second recess (13)
, (13) are formed on the further outer portions of the engaging pieces (5), (5) formed at both ends of the half body (2a).

, the first and second recesses (12) and (13) are both configured in a plane parallel to the opening direction of the halves (1a) and (1b), and the corners of the frame-shaped part (11) Part (14
).

(!4) and the lower side are sloped surfaces with a slope that matches the slope of the die, and the direction of this slope is .

It expands towards the open end of the half (1a).

Further, the engaging pieces (5), (5) correspond to the retaining protrusions (51), (51) provided on the half body (1b) in a freely engaging and detachable manner, and each engaging piece (5) T at the base end of the frame-shaped part (U,)
8 through a fleshy joint P1 (52), and a retaining hole (53) is opened at a position corresponding to the engaging protrusion (51). Further, in the frame-shaped part (11), a notch (15) cut from the open end of the half body (1a) is formed at a position corresponding to the engagement protrusion (51). An engaging protrusion (51) formed near the open end of 1b) fits into this notch (15). Further, a protrusion ff1 (1B) is partially formed in the center of this notch (15), and this protrusion (16) is a side wall of the engagement protrusion (51), and the half body (1b) It is adapted to fit into a fitting recess (53) that opens toward the open end side.

The bag constructed in this manner can be injection molded using a mold constructed as shown below.

The mold used to manufacture the bag having the configuration described above consists of a male mold (P) that is the core side and a female mold (D) that is the cavity side. The mold structure for molding the main parts of half body (1a) and half body (1b) is as shown in Fig. 8. It becomes.

That is, since the connecting piece (3) is arranged at a position that coincides with the edge of the frame-shaped part (II) when the half body (1a) and the half body (tb) are fitted together, Cavities and core portions corresponding to the halves (1a) and (1b) are formed so as to have a step corresponding to the fitting depth, and the half body (1b)
The parting surface corresponding to the open end of the half body (1a)
The parting surface corresponding to the open end, that is, the edge of the frame-shaped part (11), has a step corresponding to the fitting depth, as shown in the figure. As a result, female type (D)
When injection molding is performed by placing the male mold (P) against the two halves (1
a) and half body (1b) can be molded simultaneously and integrally.

In addition, as shown in FIG.
) is arranged, and in the mold of this example, the frame-shaped part (!l)
A first recess (12) and a second recess (13) formed in
The part corresponding to the protrusion on the open end side is the end face (41) of the slide core (4). Therefore, at the time of completion of injection molding, the first recess (12) or the second recess The surface of the portion (13) and the protruding portion on the open end side following this concave portion form a plane parallel to the opening direction of the half body (l&) and the half body (1b). In other words, the plane is perpendicular to the parting surface.

Next, regarding the engagement piece (5), it has a configuration as shown in Fig. 9, with a half body (1a) and a half body (1b).
The open end is formed at a position where the open end extends a distance corresponding to the depth of engagement. Further, in this embodiment, in order to make the engaging piece (5) bendable, its base end and the outer peripheral surface of the half body (1a) are connected by the hinge part (52), and the frame-shaped part ( Therefore, as shown in Figure 9, the mold structure is such that only the portion corresponding to the engaging piece (5) extends from the core side to the cavity side. By adopting this configuration, the retaining piece (5) is attached to the half body (1a).
It will be molded into one piece and connected in a flexible manner.

Next, a portion corresponding to the locking protrusion (51) is constructed as shown in FIG. 1O, and a mold is constructed in the same manner as the corresponding portion of the engaging piece (5). This allows the engaging protrusion (
51) is also integrally molded so as to protrude perpendicularly to the peripheral portion of the half body (tb), as in the case of the engagement piece (5).

Incidentally, the half parts (2a) and (2b) can be manufactured using one ordinary mold structure.

When injection molding is performed using the mold configured as above, the frame portion (!1) of the half body (1a) and the open end of the half body (1b) fit together as shown in Fig. 11. Then, half (1a)
and a handle (2) on the outer periphery of the fitting part of the half body (1b).

The planar portions of the first 1tJS 24 recesses (12) and (13) formed by the retaining pieces (5), (5), the corner portions (14), and the end surfaces (41) excluding the bottom portions. , Furthermore, a lip plane (lO) on the edge side of the frame-shaped part (11) parallel to this plane part appears, and the majority of the range of the frame-shaped part (!l) located in the center of the bag appears. is a plane portion parallel to the opening direction of the half body (1a) and the half body (tb), that is, a plane perpendicular to the central cross section.

At the same time, everything required for the bag, such as the opening/closing hinges of the halves (1a) and (1b) and the locking devices for both, are integrally molded at once.

Negative values are valid.

[Brief explanation of the drawing]

Figure 1 is a front view of a bag manufactured by the method of the present invention;
Fig. 2 is a side view, Fig. 3 is a plan view, Fig. 4 is a detailed view of the engaging piece (5), Fig. 5 is a bottom view, and Fig. 6 is an A-
A cross-sectional view, Figure 7 is a B-B cross-sectional view, Figure 8 is a cross-sectional view of the main part of the mold used for manufacturing bags, and Figure 9 is a cross-sectional view of the part of the mold corresponding to the engagement piece (5). The cross-sectional view and FIG. 10 show the engaging protrusion (
51), and FIG. 11 is a detailed view of the fitting portion between half (1a) and half (1b) of the completed product. FIG. 12 and FIG. 13 are explanatory diagrams of a conventional example. (11)... Frame-shaped parts (1a), (1b), half body (2)... Handle (2a), (2b), half body part (3)... Connection piece (4 )・・Slide core (41)・・・End face

Claims (1)

[Claims] A dish-shaped half body (1a) with one end open and having a frame-shaped part (11) at the open end, and an open end part that fits into the frame-shaped part (11) and the half body (1a) ) is almost symmetrical to the half body (1
b) and the lower sides thereof are connected to each other in a flexible manner by a connecting piece (3), and the whole is integrally molded by injection molding of synthetic resin, in a method of manufacturing a synthetic resin bag,
A half body (1a) having a half body (2a) of a handle (2) integrally connected to one side of the open end, and a handle (2) similarly located at a symmetrical position of the half body (1a) on one side of the open end. ) of the other half (2
b) are connected together, and the half bodies (1b) are arranged side by side so that the constituent planes of their open edges are parallel to each other, and the half bodies (1a) and the half bodies (1b) are mutually bendably connected. In order to perform injection molding while connected by the piece (3), the cavity and core of the injection mold are manufactured, and the frame-shaped part (11
), and is capable of appearing and retracting in a direction perpendicular to the mold dividing direction on a plane part other than the corner part of the frame-shaped part (11) and the part corresponding to the half part (2a). Slide cores (4), (4) are arranged, and this slide core (4)
, (4), the end surface (41) on the product surface side is configured to be a plane parallel to the dividing direction of the mold, and the width of the end surface (41) is set smaller than the width of the frame-shaped part (11), The end surface (41) is located in the middle of the frame portion (11) in the width direction,
Further, the end surfaces (41), (41) are connected to the frame-shaped portion (11).
A method for manufacturing a synthetic resin bag, in which the bag is injection molded using a mold having the above configuration, with the bag slightly protruding from the surface of a cavity corresponding to the above.