JPH0569461A - Method for molding molded product having l-shaped cross section - Google Patents

Abstract

PURPOSE:To smoothly and certainly mold and release a guard panel, to simplify the structure of a mold to inexpensively produce the mold and to easily correspond to the molding of many guard panels and a high cycle time to enhance productivity. CONSTITUTION:In such a state that a guard panel 30 is bonded to a core mold 41 forming the inner surfaces of both of an upper plate part ID and a front plate part 1E, the guard panel 30 is pushed out in a mold opening and closing direction (m) to be released while rotated around the hinge pins 2B, 2C formed to both side plate parts 1B, 1C of the guard panel 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a method of molding an L-shaped cross-section molded article such as a guard panel used for a VHS type video cassette.

[0002]

2. Description of the Related Art FIG. 2 is a perspective view of a guard panel 1 which is attached to a VHS type video cassette body (not shown) and serves to protect a magnetic tape.

The guard panel 1 has an elongated front plate portion 1.
A and side plate portions 1B and 1C integrally formed at both ends of the front plate portion 1A. These side plate portions 1B and 1C are formed.
Hinge pins 2B and 2C for attaching the guard panel 1 to the cassette body are formed so as to face each other. On the other hand, at the lower end of the front plate portion 1A in the figure, an overhanging portion 3 ... For engaging with the cassette body is provided.
It is formed so as to project to the same side as B and 1C. Further, the hinge pin 2C is provided with a protrusion 2D for locking the spring. And this spring
The guard panel 1 is biased in the closing direction.

FIGS. 3 to 5 show an example of a mold that has been conventionally used for molding the guard panel 1 having such a shape. In addition, in this mold,
The front plate portion 1A of the guard panel 1 is formed perpendicular to the opening / closing direction of the mold. Therefore, in this mold, the hinge pins 2B and 2C are undercut.

In these drawings, reference numeral 4 is a fixed side receiving plate, and a cavity plate 5 is fixed to the fixed side receiving plate 4. A core plate 6 and a side plate 7 are arranged to face the cavity plate 5, and these plates 6 and 7 are supported by a movable side receiving plate 8.

As shown in FIG. 5, the core plate 6 has a movable core 6A fixed to a movable support plate 8 and slide cores 6 arranged at both ends of the movable core 6A.
It is composed of B and 6C. Further, these slide cores 6B and 6C and the side plate 7 can be simultaneously moved and operated in a direction in which they approach and separate from each other (a direction orthogonal to the opening / closing direction of the mold) by a slide core moving mechanism (not shown). There is. The movable core 6A defines a cavity for molding the front plate portion 1A including the undercut overhanging portions 3 ..., On the other hand, the slide cores 6B and 6C and the side plate 7 define the hinge pins 2B and 2C. Defines a cavity for molding the side plate portions 1B, 1C having the.

In order to release the guard panel 1 formed by the mold having the above structure, the mold is opened and the slide cores 6B and 6C and the side plate 7 are separated from each other as shown in FIG. And the guard panel 1 is ejected from the mold by a protrusion pin (not shown).

On the other hand, as a mold for a guard panel, which is different from the above mold, a mold as shown in FIGS. 6 to 8 is also used. In this mold, the front panel 1A of the guard panel 1
Since the width direction of is aligned with the opening and closing direction of the mold (up and down direction in FIG. 6), the overhanging portion 3 formed at the lower end of the front plate portion 1A is undercut.

In the figure, reference numeral 10 is a fixed side receiving plate, and a cavity plate 11 is fixed to the fixed side receiving plate 10. Further, a core plate 13 defining a cavity 12 for molding the guard panel 1 by abutting the tip end face of the cavity plate 11 is arranged opposite to the cavity plate 11. The core plate 13 is supported by the movable side receiving plate 14. Reference numeral 15 is a molten resin passage.

As shown in FIG. 8 (a plan view in the mold open state), the core plate 13 is slidable by a slide core moving mechanism (not shown) in a direction orthogonal to the opening / closing direction of the mold. It is composed of a core 13A and movable cores 13B and 13C arranged on both ends of the slide core 13A and fixed to a movable support plate 14.
The slide core 13A defines a part of the cavity 12 for molding the front plate portion 1A including the overcut portion 3 which is an undercut, while the movable cores 13B and 13C have hinge pins 2B and 2C. It defines another portion of the cavity 12 for molding the side plate portions 1B and 1C.

After the guard panel 1 is molded in the mold, the mold is released by opening the mold and guarding the slide core 13A by the slide core moving mechanism as shown in FIG. The guard panel 1 is separated from the panel 1, and then the guard panel 1 is ejected by a protrusion pin (not shown) to be released.

Further, in the mold shown in FIGS. 6 to 8, after the mold is opened, the slide core (protruding block) 13A is projected toward the cavity plate 11 and then attached to the projecting block 13A. A method has also been proposed in which the guard panel 1 is sucked from the left side in FIG. 7 by a suction cup of a suction device to be projected and separated from the block 13A to be released from the mold (Japanese Patent Laid-Open No. 61-
145781).

Further, the present applicant has proposed a new guard panel mold (see Japanese Patent Application No. 63-164372) or a guard panel (see Japanese Patent Application No. 1-336993). This guard panel mold is shown in FIGS.
As shown in FIG. 3, the cavity plate 16 includes the first cabinet mold 17 (see FIGS. 9 to 11) for forming the outer surfaces of the front plate portion 1A and the side plate portions 1B and 1C of the guard panel 1, and the side plate. A second cavity mold 18 (see FIG. 10) for forming the upper surface of the hinge pin 2B of the portion 1B, and a third cavity mold 19 (see FIG. 11) for forming the upper surface of the hinge pin 2C of the side plate portion 1C. And a core plate 20 for forming a first core die 21 (see FIG. 9) for forming an inner surface of the front plate portion 1A, and an inner surface of the side plate portion 1B and a lower surface of the hinge pin 2B. The second core mold 22 (see FIG. 10), the inner surface of the side plate portion 1C and the lower surface of the hinge pin 2C, the third core mold 23 (see FIG. 11) for forming the protrusion 2E, and the end face of the protrusion 2E are formed. Core pin for 4 (see FIG. 11), a direction orthogonal to the opening-closing direction of the mold (the longitudinal direction of the guard panel 1)
And a slide core 25 (see FIG. 11) for forming a concave portion of the side plate portion 1C, and the guard panel includes a protrusion 2E of the hinge pin 2C. Instead, a protrusion parallel to the front plate 1E is used. In these guard panel molds or guard panels, the upper plate portion 1D and the front plate portion 1E of the front plate portion 1A of the guard panel 1 to be molded intersect at right angles in the mold opening / closing direction. Since they are set to be inclined by a predetermined angle, the outer surface of the upper plate portion 1D and the front plate portion 1E can be subjected to embossing and engraving, respectively.

[0014]

By the way, in the mold shown in FIGS. 3 to 5 and the mold shown in FIGS. 6 to 8, in order to process the undercut portion, the opening and closing direction of the mold is different from that of the mold. It has a slide core that is operated to move in the orthogonal direction, and a slide core moving mechanism such as an air cylinder, a hydraulic cylinder, and a tilt pin for operating this slide core is provided separately from the mold opening / closing mechanism. Was necessary. Therefore, the mold structure is complicated,
There was a problem that the manufacturing cost of the mold was high. And
This is particularly unsuitable when a large number of molded products are formed by one die, that is, when so-called a large number of pieces are to be obtained. In addition, when the slide core is used for a long period of time, rattling is likely to occur and the slide core cannot slide smoothly, and it is necessary to move the slide core in a direction orthogonal to the opening / closing direction of the mold. Therefore, there is a problem that the mold opening and closing takes a long time and the cycle time becomes long, so that the productivity cannot be improved.

On the other hand, in the mold described in the above-mentioned Japanese Patent Laid-Open No. 61-145781, the cavity for molding the wide front plate portion is projected and positioned on the side of the block 13A, so that it is biased during molding. There is a problem that a large amount of pressure is applied, and the protruding block 13A is apt to cause galling, which makes it difficult for the protruding block 13A to smoothly protrude. In addition, since the suction device must be attached to the mold separately, the structure becomes complicated and the manufacturing cost of the device is low. There is a problem that is high.

Further, in the above-mentioned guard panel mold or guard panel proposed by the applicant, the upper plate portion 1
Since D and the front plate portion 1E are largely inclined with respect to the opening / closing direction of the mold, the mold processing is complicated and requires a lot of man-hours when the engraved surface of the mold is manufactured. There is a problem in that

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an L-shaped panel such as a guard panel.
Molded cross-section molded products can be molded smoothly and reliably, and can be released from the mold. Moreover, the mold structure is simple and can be manufactured at low cost, and it is easy to handle multiple pieces and high cycle time. An object of the present invention is to provide a method for molding an L-shaped cross-section molded article that can improve the property.

[0018]

According to a first aspect of the present invention, an L-shaped cross-section molding for molding an L-shaped cross-section molded product in which a second plate-shaped portion is integrally formed with a first plate-shaped portion by a mold. A method of molding an article, comprising:
With the die cross-section molded product attached, the L-shaped cross-section molded article is extruded along the die opening / closing direction, and the L-shaped cross-section article is formed by using the convex portions formed on both sides of the L-shaped cross-section molded article as fulcrums. The cross-section molded product is released while rotating.

According to a second aspect of the present invention, the first plate-shaped portion is molded in a state of being inclined at a predetermined angle with respect to the die opening / closing direction of the die.

Further, a third aspect of the present invention is characterized in that the L-shaped cross-section molded article is a VHS type guard panel.

Further, according to claim 4 of the present invention, the front panel of the guard panel is molded in a state of being inclined at a predetermined angle with respect to the mold opening / closing direction, and the recess formed in the side panel and the hinge pin are formed. The protrusion is formed in a state along the mold opening / closing direction.

According to a fifth aspect of the present invention, the recess formed in the side plate portion of the guard panel and the projection of the hinge pin are tapered at a required angle.

[0023]

According to the first aspect of the present invention, the L-shaped cross-section molded article is formed on the inner surface of the L-shaped cross-section molded article in which the second plate-shaped section is integrally formed on the first plate-shaped section. While the L-shaped cross-section molded article is rotated by pushing the L-shaped cross-section molded article along the mold opening / closing direction with the convex portions formed on both sides of the L-shaped cross-section molded article as fulcrums, It is extruded and released from the mold.

According to claim 2 of the present invention, the first
By molding the plate-shaped portion in a state in which the plate-shaped portion is inclined at a predetermined angle with respect to the mold opening / closing direction, the L-shaped cross-section molded product can be easily pushed out while rotating, and the mold can be smoothly released from the mold.

Further, in claim 3 of the present invention, V
The undercut portion of the guard panel can be easily released by using it in the molding of the HS type guard panel.

Further, according to a fourth aspect of the present invention, the front plate portion of the guard panel is molded in a state of being inclined at a predetermined angle with respect to the mold opening / closing direction, and a recess formed in the side plate portion is formed. By forming the protrusion of the hinge pin along the mold opening / closing direction, the recess of the side plate portion and the protrusion of the hinge pin are smoothly released from the mold.

According to the fifth aspect of the present invention, the recess formed in the side plate portion of the guard panel and the protrusion of the hinge pin are tapered by a required angle, so that the recess and the protrusion are further reduced. Improves separation from the mold.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. The basic structure of the guard panel 30 formed by the method of the present invention is the same as that of the guard panel 1 shown in FIG. 2, and the same parts are designated by the same reference numerals and the description thereof will be omitted.

The difference between the guard panel 30 and the conventional guard panel 1 is that a recess 31 for locking a guard panel rotation preventing stopper formed on the side plate portion 1C and a protrusion formed on the hinge pin 2C are provided. 32 structure. The recess 31 has an inclined wall surface 31A parallel to the ridgeline formed by the side plate portion 1C and the front plate portion 1E and a wall surface 31B parallel to the upper plate portion 1D.
And a required angle α with respect to the mold opening / closing direction m (for example, 3 degrees, 3
(Degrees to 5 degrees) inclined wall surface 31C and these wall surfaces 3
It is formed of a bottom surface 31D which is continuous with 1A, 31B and 31C. In addition, the protrusion 3 formed on the hinge pin 2C.
2 is formed in a truncated cone shape with its axis aligned with the mold opening / closing direction m and is inclined in a tapered shape. The inclination angle of the truncated cone shape is, for example, 3 degrees, 3 degrees to 5 degrees. It is set. Then, the front plate portion 1E is formed in the mold with a predetermined angle β (for example, 3 degrees, 3 degrees to 5 degrees) with respect to the mold opening / closing direction m.

The mold for molding the guard panel 30 is
A mold 40 that forms part of the outer surface of the guard panel 30 and the inner surfaces of the side plate portions 1B and 1C and the upper half of the hinge pins 2B and 2C (upper side of the parting line PL in FIG. 1), and this mold type. The core mold 41 is provided so as to be close to and away from the mold 40 along the mold opening / closing direction m and forms a large part of the inner surface of the guard panel 30. Then, through the core mold 41,
A projecting pin 42 is provided to project an end portion of the front plate portion 1E of the guard panel 30 along the mold opening / closing direction m.

Guard panel 30 constructed as described above
In the case of molding with the above-mentioned injection molding die, first, as in the conventional case, the core die 41 is brought into contact with the cavity die 40,
After forming a cavity between the cavity mold 40 and the core mold 41, the molten resin supplied through the cavity mold 40 is filled in the cavity and cooled and solidified.

Then, the core mold 41 is used with respect to the mold mold 40.
When the mold is opened along the mold opening / closing direction m, the molded product molded in the cavity is attached to the core mold 41, and
Get away from. Next, when the end of the front plate portion 1E of the molded product (guard panel) 30 is projected by the projecting pin 42, the guard panel 30 moves from the core mold 41 side to the cavity mold 40 side, and the both side plate parts 1B, 1C
The hinge pins 2B and 2C are pivoted clockwise in FIG. Therefore, the undercut overhanging portion 3 smoothly separates from the core mold 41 outward.

In this case, in the recess 31 of the side plate portion 1C and the projection 32 of the hinge pin 2C, a force to rotate clockwise in FIG. 1 with the hinge pins 2B and 2C as a fulcrum acts, so that the recess 31 is formed. Although the protrusion 32 tends to deform (twist), the core mold 4 is formed in the recess 31 of the side plate portion 1C and the protrusion 32 of the hinge pin 2C together with the turning force.
In addition to the force acting to separate from 1 along the mold opening / closing direction m, both inclined wall surfaces 31A and 31C forming the recess 31 are formed.
Is set so as to open toward the core mold 41 side with respect to the mold opening / closing direction m, and the projection 32 is formed in a truncated cone shape with its axis aligned with the mold opening / closing direction m and being tapered. Therefore, as the guard panel 30 is separated from the core mold 41 in the mold opening / closing direction m, a clearance is generated between the molded product (the recess 31 and the protrusion 32) and the core mold 41 facing the molded product, Therefore, the guard panel 30
Is smoothly released from the core mold 41 by rotating around the hinge pins 2B and 2C as a fulcrum while moving toward the mold 40 along the mold opening / closing direction m.

Further, since the front plate portion 1E is formed in a state of being inclined at a predetermined angle β with respect to the mold opening / closing direction m, the outer surface of the upper plate portion 1D and the front plate portion 1E are subjected to embossing, engraving, etc. It is possible to apply.

In the above embodiment, the overhanging portion 3 serving as an undercut portion and the recess 3 of the side plate portion 1C are formed.
1, due to the protrusion 32 of the hinge pin 2C, the front plate portion 1E is inclined in the mold with a predetermined angle β with respect to the mold opening / closing direction m. Depending on the shapes of the recess 31 and the protrusion 32 of the hinge pin 2C or the properties of the resin, the inclination of the angle β may not be provided (β = 0 may be used). Further, although the guard panel 30 has been described in the above embodiment, the present invention is not limited to this and can be widely applied to molded articles having an L-shaped cross section. In this case, if the hinge pins 2B and 2C, which are the center of rotation at the time of releasing the mold, are unnecessary, after the releasing, these hinge pins 2B and 2C
It is also possible to remove 2C.

[0036]

As described above, according to the first aspect of the present invention.
Is the above L-shaped cross-section molding in a state in which the above-mentioned L-shaped cross-section molded product is attached to the mold body forming the inner surface of the L-shaped cross-section molded product in which the second plate-shaped portion is integrally formed with the first plate-shaped portion. By extruding the product along the mold opening and closing direction, the L-shaped cross-section molded product is extruded while rotating with the convex portions formed on both sides of the L-shaped cross-section molded product as fulcrums, and released from the mold body. Therefore, an L-shaped cross-section molded product such as a guard panel can be smoothly and reliably molded and released, and the mold structure is simple and can be manufactured at low cost. It is possible to easily cope with high cycle time and high cycle time, and improve productivity.

According to a second aspect of the present invention, the L-shaped cross-section molded product is easily extruded while being rotated by molding the first plate-shaped portion in a state of being inclined at a predetermined angle with respect to the mold opening / closing direction of the mold. In addition, the mold can be smoothly released from the mold.

Further, the third aspect of the present invention is used in the molding of the VHS type guard panel, whereby the undercut portion of the guard panel can be easily released.

Further, according to claim 4 of the present invention, the guard panel is molded in a state in which the front plate portion is inclined at a predetermined angle with respect to the mold opening / closing direction, and the recess formed in the side plate portion and the protrusion of the hinge pin are formed. By molding and in a state along the mold opening / closing direction, the recess of the side plate portion and the protrusion of the hinge pin can be smoothly released from the mold.

According to a fifth aspect of the present invention, the concave portion formed on the side plate portion of the guard panel and the projection of the hinge pin are tapered at a required angle, so that the concave and projection molds can be further removed. You can improve the separation.

[Brief description of drawings]

FIG. 1 is a sectional view of a guard panel for explaining an embodiment of the present invention.

FIG. 2 is a perspective view showing a conventional guard panel.

FIG. 3 is a cross-sectional view showing an example of a conventional guard panel mold.

FIG. 4 is a cross-sectional view of a core plate portion when the mold of FIG. 3 is opened.

5 is a plan view of the core plate portion of FIG.

FIG. 6 is a cross-sectional view showing another example of a conventional guard panel mold.

7 is a cross-sectional view of the core plate portion when the mold of FIG. 6 is opened.

FIG. 8 is a plan view of the core plate portion of FIG.

FIG. 9 is a cross-sectional view of a mold part for molding the central part of the guard panel, showing another example of a conventional guard panel mold.

10 is a cross-sectional view of a mold for molding one side plate of the guard panel of FIG.

FIG. 11 is a cross-sectional view of a mold for molding the other side plate of the guard panel of FIG.

[Explanation of symbols]

 1C Side plate part 1D Upper plate part (second plate part) 1E Front plate part (first plate part) 2B Hinge pin (convex part) 2C Hinge pin (convex part) 30 Guard panel (L-shaped cross-section molded product) 31 Recess 32 Protrusion 40 Cavity type 41 Core type (mold body) m Mold opening / closing direction

Claims (5)

[Claims] 1. A method for forming an L-shaped cross-section molded product, wherein an L-shaped cross-section molded product in which a second plate-shaped portion is integrally formed on a first plate-shaped portion is molded by a die, wherein The L-shaped cross-section molded article is formed on both sides of the L-shaped cross-section molded article by extruding the L-shaped cross-section molded article along the mold opening / closing direction in a state where the L-shaped cross-section molded article adheres to the mold body forming the inner surface of the part. A method for molding an L-shaped cross-section molded article, characterized in that the L-shaped cross-section molded article is released from the mold while rotating with the convex portion as a fulcrum. 2. The method for molding an L-shaped cross-section molded article according to claim 1, wherein the first plate-shaped portion is molded in a state of being inclined at a predetermined angle with respect to the mold opening / closing direction. 3. The L according to claim 1 or 2, wherein the L-shaped cross-section molded article is a VHS type guard panel.
Molding method for molded product with cross section. 4. The front panel of the guard panel is molded in a state of being inclined at a predetermined angle with respect to the mold opening / closing direction, and
4. The method for molding an L-shaped cross-section molded article according to claim 3, wherein the recess formed in the side plate portion and the protrusion of the hinge pin are molded in a state along the mold opening / closing direction. 5. The method for forming an L-shaped cross-section molded article according to claim 3, wherein the recess formed in the side plate portion of the guard panel and the protrusion of the hinge pin are tapered at a required angle.