JPH07195462A - Injection molding method and injection mold - Google Patents

Abstract

PURPOSE:To obtain an injection molding method for obtaining a resin molded piece of an ununiform-section structure free from a defective appearance, such as a weld line and a flow mark, or obtain a mold therefor. CONSTITUTION:A recess 20C is provided in a part of inner wall surfaces 20A, 20B opposed to each other, of a mold body 20. A movable mold 22 is provided so as to move between a first position where a top face 22A is positioned nearly at an end face of the recess 20C to block one end of the recess 20C and a second position where the top face 22A is separated into the recess 20C. A melt resin is charged into a cavity formed by the movable mold 22 positioned on the first position. After that, a melt resin is charged into a new cavity gradually formed as the movable mold 22 moves to the second position in accordance with a pressure in the cavity. In this manner, a resin molded piece of an ununiform-section structure is obtained. Alternatively, a resin may be charged after the movable mold 22 is moved to the second position after the elapse of a fixed time after a melt resin is charged when the movable mold 22 is on the first position. In this method, a frame- or box-form resin molded piece having a good appearance can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding method and an injection molding die for manufacturing a resin molded product having an uneven thickness structure or having a corner portion.

[0002]

2. Description of the Related Art Some synthetic resin molded products have a wall thickness that varies depending on their location or have a corner at a portion where the surfaces intersect, like a box. For example, it is used for speaker boxes and VTR panels in household appliances, for housings of personal computers in computers, and for emblems and car stereo escutcheons in automobiles. A resin molded product having such a change in wall thickness or having a corner can be obtained by a method of directly injecting a molten resin into a mold whose outer shape is modeled.

[0003]

However, this method has a problem of poor appearance such as so-called weld line, flow mark and gas burn. 9 (a), (b)
FIG. 3A is a front view and a side view of a resin molded product showing a place where a weld line and a flow mark are generated when a resin molded product having a change in wall thickness is manufactured by this method. In a mold for forming such a resin molded product, a gate for injecting a molten resin is generally provided in the thick portion.
This is because the thick portion has less resistance to resin flow than the thin portion, and the molten resin can flow easily. The molten resin injected from this gate flows into the thin wall portion through the thick wall portion, but the flow rate appears on the surface of this portion because there is a difference in how pressure is applied at the portion where the wall thickness changes and the filling speed changes. In addition, the molten resin flowing from the center of the thick portion to the thin portion in the direction indicated by the arrow 53 in FIG.
The molten resin flowing from the periphery of the thick portion to the thin portion collides in the directions indicated by 4, 55 to form the weld line 52.

10 (a) and 10 (b) use a mold having a frame-shaped cavity in which the periphery is thick and has a corner, and the bottom surrounded by the corner is thin. FIG. 3 is a front view and a cross-sectional view of a resin molded product showing a weld line and a place where gas burn occurs when a resin molded product is manufactured. In this case, a gate for injecting the molten resin is provided in the mold portion facing the center of the bottom of the cavity. still,
When a gate is provided in another mold portion, the degree of weld line and uneven thickness defect that occur is very poor. The molten resin injected from the gate passes through the bottom in the direction indicated by arrow 63 in FIG.
It flows into the opposite corners of the set. The molten resin that has flowed into the pair of opposite corners in the direction shown by the arrow 64 in FIG. 10 collides with the molten resin that has flowed in from the opposite direction, and the weld line 62 is formed. Further, due to the molten resin that goes around the corners, the air inside cannot be completely exhausted, and gas burn 66 also occurs.

FIG. 11 is a resin molding showing a place where a weld line and a flow mark are generated when a molten resin molded product is manufactured using a mold having a box-shaped cavity whose periphery is surrounded by side faces. It is a perspective view of an article. Also in this case, similarly to the mold having the frame-shaped cavity, a gate for injecting the molten resin is provided in the mold portion facing the center of the bottom of the cavity. The molten resin injected from the gate flows into the side face through the bottom portion, but the flow mark 70 appears on the side face because the resin flow changes at the portion where the wall thickness changes. Further, the molten resin that has flown into one pair of opposing side surfaces near the gate of the two pairs of opposing side surfaces wraps around to the other pair of opposing side surfaces, and the molten resin that has flowed directly into the side surface from the bottom portion. A collision occurs and a weld line 72 is formed.

Therefore, it is an object of the present invention to provide an injection molding method for producing a resin molded product which does not have a defective appearance such as weld lines, flow marks and gas burning, and a mold for the same.

[0007]

In order to achieve the above object, according to the present invention, a movable mold part which is movable is provided in a mold, and a portion or corner having a change in wall thickness is provided at the tip of the movable mold part. The surface or the side surface is separated, and one of the separated parts is filled with the molten resin, and then the moving mold part is moved to fill the other part with the molten resin.

That is, according to the present invention, the main body of the mold in which a concave portion or an opening portion is provided in a part of the inner wall surface facing each other and the body portion of the opposite inner wall surface opposite to the concave portion or the opening portion. A first position in which the tip end surface is substantially in contact with the portion and a side surface closes a part of a space sandwiched by the facing inner wall surfaces; and the tip end surface is in the direction of the recess or the opening from the first position. A movable mold part that is movable between the separated second positions while the side surface is in contact with the inner wall surface around the recess or the opening, and the tip face of the movable mold part is the first mold part. Injecting the molten resin on the surface facing the cavity formed when the movable mold part moves between the first position and the second position. Using a mold having a gate capable of A new cavity is formed by injecting the molten resin from the gate when the container is in a stationary position, and then gradually moving the moving mold part to the second position according to the pressure of the molten resin in the cavity. An injection molding method is provided in which the molten resin is filled in to obtain a molded product having a change in wall thickness.

Further, according to the present invention, the main body of the mold in which a concave portion or an opening portion is provided in a part of the facing inner wall surface and the opposite side of the facing inner wall surface from the concave portion or the opening portion. And a direction in which the tip surface is in contact with the portion of the side wall and a side surface closes a part of a space sandwiched by the facing inner wall surfaces, and the tip surface is closer to the concave portion or the opening than the first position. A movable mold part that is movable between the second positions separated from each other while the side surface is in contact with the inner wall surface around the recess or the opening, and the movable mold part is at the first position. It is possible to inject the molten resin on the surface facing the cavity formed at a certain time, while the moving die part moves between the first position and the second position. When a mold having a gate is used and the moving mold part is at the first position The molten resin is injected and injected from the gate, and after a lapse of a certain time, the movable mold part is moved to the second position, and as a result, the cavity that is newly formed is filled with the molten resin to change the wall thickness. An injection molding method for obtaining a molded article is provided.

Further, according to the present invention, the main body of the mold in which a concave portion or an opening portion is provided in a part of the inner wall surfaces facing each other, and the concave portion or the opening portion connected to one of the inner wall surfaces facing each other. A front end surface having the same shape as that of the end surface of the concave portion or the opening portion, and a first position that closes one end of the concave portion or the opening portion; A movable mold part capable of moving while contacting an inner wall surface around the recess or the opening between a second position separated in the recess or in the opening, and the moving; The moving mold part is moved between the first position and the second position on the surface facing the cavity formed when the mold part is in the first position. Using a mold having a gate capable of injecting molten resin between The molten resin is injected and injected from the gate when the moving die portion is in the first position, and then the moving die portion is moved to the second position in accordance with the pressure of the molten resin in the cavity. An injection molding method is provided in which a new cavity that gradually occurs while moving is filled with the molten resin to obtain a molded product with a change in wall thickness.

Further, according to the present invention, the main body of the mold in which a concave portion or an opening portion is provided in a part of the facing inner wall surface, and the concave portion or the opening portion connected to one of the facing inner wall surface. A front end surface having the same shape as that of the end surface of the concave portion or the opening portion, and a first position that closes one end of the concave portion or the opening portion; A movable mold part capable of moving while contacting an inner wall surface around the recess or the opening between a second position separated in the recess or in the opening, and the moving; The movable die part is located on the surface facing the cavity formed when the tip end surface of the die part is in the first position, and the movable die part is located at the first position and the second position. Mold with gate capable of injecting molten resin while moving between Used, the movable mold member is the first
The molten resin is injected and injected from the gate when the position is set to, and after a certain period of time, the moving mold part is moved to the second position.
There is provided an injection molding method for obtaining a molded product having a wall thickness change by moving the resin to the position (1) and filling a cavity newly generated as a result with the molten resin.

Further, according to the present invention, a recess or an opening is provided around one of the inner walls facing each other, and the space formed by the inner wall facing the recess or the opening is box-shaped. A tip end surface substantially abuts on the main body portion of a certain mold and the other of the facing inner wall surfaces on the side opposite to the recess or the opening, and the side surface closes the periphery of the space sandwiched by the facing inner wall surfaces. And a second position in which the tip end face is away from the first position in the direction of the recess or the opening, the side surface is an edge around the inner wall surface on the side of the recess or the opening. A movable mold part that can move while being in contact with, and a movable mold part on a surface facing the cavity formed when the movable mold part is in the first position, Injecting molten resin while moving between the first position and the second position A mold having a gate that can be turned on, and the molten resin is injected and injected from the gate when the moving mold part is at the first position, and then, in accordance with the pressure in the cavity. An injection molding method is provided in which a cavity communicating with the cavity is filled with the molten resin to obtain a molded product with a change in wall thickness while moving the movable mold part to the second position.

Further, according to the present invention, a recess or an opening is provided around one of the facing inner wall surfaces, and the space formed by the recess or the opening and the facing inner wall surface is box-shaped. A tip end surface substantially abuts on the body portion of the mold and the other of the facing inner wall surfaces on the side opposite to the recessed portion or the opening portion, and the side surface closes the periphery of the space sandwiched by the facing inner wall surfaces. Between the position and a second position in which the tip end face is away from the first position in the direction of the recess or the opening, the side surface surrounds the facing inner wall surface on the side of the recess or the opening. A movable mold part that can move while contacting an edge, and a movable mold part on a surface facing a cavity formed when the movable mold part is in the first position, The molten resin while moving between the first position and the second position A mold having an injectable gate is used, and the molten resin is injected and injected from the gate when the movable mold part is at the first position, and then the movable mold after a certain time has elapsed. An injection molding method is provided in which a part is moved to the second position, and as a result, a cavity communicating with the cavity is filled with the molten resin to obtain a molded product having a change in wall thickness.

Further, according to the present invention, the main body of the mold in which a concave portion or an opening portion is provided in a part of the facing inner wall surface, and the opposite side of the facing inner wall surface from the concave portion or the opening portion. And a direction in which the tip surface is in contact with the portion of the side wall and a side surface closes a part of a space sandwiched by the facing inner wall surfaces, and the tip surface is closer to the concave portion or the opening than the first position. A movable mold part that is movable between the second positions separated from each other while the side surface is in contact with the inner wall surface around the recess or the opening, and the movable mold part is at the first position. It is possible to inject the molten resin on the surface facing the cavity formed at a certain time, while the moving die part moves between the first position and the second position. A gate, means for holding the movable die part in the first position, and the movable die Means for holding the portion at the second position, and the movable die after the molten resin is injected and injected from the gate into the cavity formed when the movable die portion is at the first position. An injection molding die having means for moving a die part from the first position to the second position is provided.

Further, according to the present invention, the main body of the mold in which a concave portion or an opening portion is provided in a part of the inner wall surface facing each other and the concave portion or the opening portion connected to one of the inner wall surfaces facing each other. A front end surface having the same shape as that of the end surface of the concave portion or the opening portion, and a first position that closes one end of the concave portion or the opening portion; A movable mold part capable of moving while contacting an inner wall surface around the recess or the opening between a second position separated in the recess or in the opening, and the moving; The moving mold part is moved between the first position and the second position on the surface facing the cavity formed when the mold part is in the first position. The gate capable of injecting molten resin between the Means for holding the movable die portion at the second position, and means for holding the movable die portion in the cavity formed when the movable die portion is at the first position from the gate. After the molten resin is injected and injected, the moving mold part is moved from the first position to the second position.
And a means for moving it to the position.

Further, according to the present invention, a recess or an opening is provided around one of the facing inner wall surfaces, and the shape of the space formed by the recess or the opening and the facing inner wall surface is box-shaped. A tip end surface substantially abuts on the main body portion of a certain mold and the other of the facing inner wall surfaces on the side opposite to the recess or the opening, and the side surface closes the periphery of the space sandwiched by the facing inner wall surfaces. And a second position in which the tip end face is away from the first position in the direction of the recess or the opening, the side surface is an edge around the inner wall surface on the side of the recess or the opening. A moving mold part that can move while touching
On the surface facing the cavity formed when the moving mold part is in the first position, the moving mold part is located between the first position and the second position. A gate capable of injecting a molten resin while moving, a means for holding the moving die part in the first position, a means for holding the moving die part in the second position, After the molten resin is injected and injected from the gate into the cavity formed when the moving mold unit is at the first position, the moving mold unit is moved from the first position to the second position. And an injection mold having means for moving up to.

[0017]

Embodiments Embodiments will be described below with reference to the drawings.
3A is a front sectional view showing the first embodiment of the present invention, and FIG. 3B is a plan sectional view thereof. FIG. 3C is a front sectional view of the main body portion 10 of the mold according to the first embodiment. The main body 10 has inner wall surfaces 10A, 10B facing each other and a recess 10C on one of the inner wall surfaces 10A, forming an L-shaped space. The tip surface of the recess 10C has a recess 10C.
The first wall surface 10B, which substantially abuts the inner wall surface 10B on the opposite side and closes a part of the space sandwiched between the inner wall surfaces 10A and 10B whose side surfaces face each other.
A movable die part 12 is attached which can move between the position of and the second position where the tip end face is separated in the direction of the recess 10C while the side face is in contact with the inner wall surface 10F around the recess. The other part of the space sandwiched between the facing inner wall surfaces 10A and 10B is closed by the other inner wall surface of the main body 10 of the mold, so that the moving mold part 12 has a first part shown in FIG. Wall surfaces 10A, 10B facing each other when in the position
The space between them is closed.

In the movable die 12 and the recess 10C, the movable die 1 is moved toward the inner wall surface 10B opposite to the recess 10C.
A spring 16 for biasing 2 is attached. A rod 17 for holding the movable die portion 12 in the second position is attached to the recess 10C so that the movable die portion 12 does not move beyond the second position. It is indicated by a dotted line in the figure. In addition, the inner wall surfaces 10A and 10B facing each other are tied together to form the inner wall surfaces 10A and 10B.
Inner wall surface 1 of the main body 10 of the mold that closes a part of the space sandwiched by
A gate 10E for injecting a molten resin is provided at 0D. This main part 10C is a parting line 1
The fixed side 10H and the moving side 10I can be opened at 0G.

A process for producing a molded product having a varied wall thickness using this mold will be described. First, due to the elastic force of the spring 16, the tip end surface 12 of the movable die unit 12 is
A is held at the first position where it almost contacts the inner wall surface 10B. At this time, by the side surface 12B of the movable die unit 12,
The space sandwiched between the opposing inner wall surfaces 10A and 10B is closed. In this state, when the molten resin 18 is injected from the gate 10E with a predetermined pressure, the space sandwiched between the opposing inner wall surfaces 10A and 10B is filled with the molten resin. FIG. 4A is a front sectional view of the mold showing this state.

Since the molten resin 18 is injected at a predetermined pressure, the moving mold part 12 gradually moves from the inner wall surface 10B to the recess 10C side against the force of the spring 16. At this time, the molten resin 18 is injected into the cavity that is gradually generated. Eventually, the moving die part 12 moves to the second position, and the cavity formed at this time is filled with the molten resin. FIG. 4B is a front sectional view showing this state.

Next, a second embodiment of the present invention will be described. FIG. 1A is a front sectional view showing a second embodiment of the present invention, and FIG. 1B is a plan sectional view of a main body portion 20 of a mold. FIG. 1C is a front sectional view of the main body portion 20 of the mold of the second embodiment. The movable mold part 22 has a recessed portion 20C that is continuous with one inner wall surface 20A of the inner wall surfaces that the front end surface 22A faces.
Has the same shape as the end face of the concave portion 20C and is located substantially at this end face to close one end of the concave portion 20C, and between the second position in the concave portion 20C whose tip surface is away from the end face of the concave portion. The edge of the front end surface 22A moves while being in contact with the inner wall surface 20F of the recess 20C.

A spring 26 for urging the moving mold portion 22 toward the facing inner wall surface 20B is attached to the moving mold portion 22 and the concave portion 20C.
In order to hold the one end of C at the first position where it closes, one end of the moving die 22 is provided with a collar 22 on the side opposite to the inner wall surface 20B.
A stepped portion is provided in C and the concave portion 20C. Brim 22
C is caught in the stepped portion of the concave portion 20C, and the moving die portion 22
Are held in the first position. Further, the recess 20C has a rod for holding the movable die part 22 in the second position so that it does not move beyond the second position. The other points are similar to those of the mold of the first embodiment.

A process for producing a molded product having portions having different wall thicknesses using the mold of the second embodiment will be described. First, the moving mold part 22 includes a spring 26 and a collar 22C.
And the stepped portion of the concave portion 20C holds the concave portion 20C at the first position that closes one end of the concave portion 20C. At this time, the moving die unit 22
A space sandwiched by the front end surface 22A and the opposing inner wall surfaces 20A, 20B is formed. Gate 20 in this state
When the molten resin 18 is injected from E at a predetermined pressure, this space is filled with the molten resin 18. FIG. 2A is a front sectional view showing this state.

Since the molten resin 18 is injected at a predetermined pressure, the movable die part 22 gradually moves in the recess 20C from the first position against the force of the spring 26. At this time, the molten resin 18 is injected into the cavity that is gradually generated. Eventually, the moving mold part 22 moves to the second position, and the cavity formed at this time is filled with the molten resin. FIG. 2B is a front sectional view showing this state.

Next, a third embodiment of the present invention will be described. 5A is a front sectional view showing a third embodiment of the present invention, and FIG. 5B is a plan sectional view thereof. Figure 5
(C) is a front sectional view of a main body 30 of the mold of the third embodiment. The main body portion 30 has a recess 30C around the inner wall surface 30A on one side of the inner wall surfaces 30A and 30B facing each other, and a peripheral portion has a meat shape in a shape formed by a space sandwiched between the inner wall surfaces 30A and 30B facing the recess 30C. It is thick and thin at the center, and has a frame shape.

An inner wall surface 30 facing the recess 30C
A first position in which a tip surface 30A having the same shape as the end surface of the recess 30C connected to one inner wall surface 30A of A and 30B is located substantially at the end surface of the recess 30C and closes the end surface of the recess 30C;
The edge of the tip end surface 32A is recessed between the second position where the tip end surface 32A is separated from the end surface of the recess 30C into the recess 30C.
A movable mold part 32 is provided which moves while contacting the inner wall surface 30F around C.

A spring 36 is attached to the movable die portion 32 to urge the movable die portion 32 toward the inner wall surface 30B opposite to the concave portion 30C.
In order to keep the first position of 0C closed at the first position, the movable die part 32 has a collar 32C on the side opposite to the inner wall surface 30B.
And a step portion of the recess 30C is provided. Brim 30C
Therefore, the movable die part 32 is held at the first position by being caught by the stepped part of. A rod 37 for holding the moving die part 32 in the second position is attached to the recess 30C so that the moving die part 32 does not move beyond the second position. Further, a gate 30E for injecting the molten resin is provided on the fixed side 30H. The main body 30C has a parting line 30G and a fixed side 30H.
And the moving side 30I can be opened.

A process for manufacturing a molded product having a thick peripheral portion and a thin central portion using the mold of the third embodiment will be described. First, the moving die 32 is held at the first position where one end of the recess 30C is closed by the flange 32C and the step of the recess 30C. At this time, a space sandwiched by the front end surface 32A of the movable die part 32 and the inner wall surfaces 30A and 30B facing each other is formed. Gate 30E in this state
Then, when the molten resin 18 is injected at a predetermined pressure, the space is filled with the molten resin 18. FIG. 6A is a front sectional view showing this state.

Since the molten resin 18 is injected at a predetermined pressure, the moving die 32 gradually moves in the recess 30C from the first position against the force of the spring 36. At this time, the molten resin 18 is injected into the cavity that is gradually generated. Eventually, the moving die part 32 moves to the second position, and the cavity formed at this time is filled with the molten resin. FIG. 6B is a front sectional view showing this state.

Next, a fourth embodiment will be described. Figure 7
(A) is a front sectional view showing a fourth embodiment of the present invention,
FIG. 7B is a plan sectional view thereof. FIG. 7C shows the fourth
It is a front sectional view of the main body portion 40 of the mold of the embodiment. The main body portion 40 has a recess 40C around the inner wall surface 40A on one side of the inner wall surfaces 40A and 40B facing each other, and the space formed by the inner wall surfaces 40A and 40B facing the recess 40C has a box shape. Has become.

In the recess 40C, the front end surface 42A is almost in contact with the inner wall surface 40B opposite to the recess 40C, and the side surface 4
Inside of the side surface 42B facing the recessed portion 40C is between a first position where the inner wall surfaces 40A facing the 2B face each other, and a second position where the end surface 42A is closed in the direction of the recessed portion 40C. One inner wall surface 40A of the wall surfaces 40A and 40B
A movable die unit 42 is provided which can move while contacting the peripheral edge of the. In this moving mold part 42, the moving mold part 4 is moved toward the inner wall surface 40B opposite to the recess 40C.
A spring 46 for biasing 2 is attached. The concave portion 40C is provided with a rod 47 for holding the movable die portion 42 in the second position, and the movable die portion 4 is provided.
The 2 does not move past the second position.
Further, a gate 40E for injecting the molten resin is provided on the inner wall surface 40B. The main body portion 40C can open the fixed side 40H and the movable side 40I at the parting line 40G.

A process for manufacturing a box-shaped molded product using the mold of the fourth embodiment will be described. First, the moving die part 42 is held by the elastic force of the spring 46 at the first position in which the front end surface 42A of the moving die part 42 is substantially in contact with the inner wall surface 40B. At this time, the moving mold part 42
Inner wall surfaces 40A, 40B facing each other by the side surface 42B of the
The space between them is closed.

In this state, when the molten resin 18 is injected from the gate 40E at a predetermined pressure, the inner wall surfaces 40A, 4A facing each other,
The space sandwiched by 0B is filled with molten resin. FIG. 8A is a front sectional view of the mold showing this state. Molten resin 18
Is injected at a predetermined pressure, so that the movable mold part 42 gradually moves from the inner wall surface 40B to the recess 40C side against the force of the spring 46.

At this time, when the movable mold part 42 is in the first position, the cavity of the recess 40C communicates with the cavity surrounded by the side surface 42B and the inner wall surfaces 40A, 40B.
The molten resin 18 is injected into the cavity of the recess 40C. Eventually, the moving mold part 42 moves to the second position, and the cavity formed at this time is filled with the molten resin.

FIG. 8B is a front sectional view showing this state. In the above four embodiments, the moving mold parts 12, 22, 32, 42 are moved from the first position to the second position as means for holding the movable mold parts 12, 22, 32, 42 depending on the pressure of the molten resin in the cavity. Spring 16 as a means to move to
Although 26, 36 and 46 are used, hydraulic means may be used. Alternatively, the molten resin may be injected and injected into the cavity when the movable die portion is at the first position, and the movable die portion may be forcibly retracted after a certain time has elapsed.

[0036]

As described above, according to the present invention, the movable die portion is provided in the die, and the portion or the corner portion where the wall thickness is changed is isolated by the tip surface or the side surface of the movable die portion. The molten resin is filled with one pressure on one side that is isolated. After that, the movable mold part is moved to fill the molten resin from the previously filled part to the part or corner where the wall thickness changes. Since the molten resin is filled in the previously filled portion with sufficient pressure, it is possible to fill the portion or the corner portion where the wall thickness changes with sufficient holding pressure.

As described above, the stepwise filling and the filling of the portion or the corner portion where the wall thickness changes with sufficient holding pressure can prevent the resin flow generated at the portion or the corner portion where the wall thickness changes. It is possible to suppress the occurrence of poor appearance such as weld lines, flow marks, and gas burning.
It is also possible to remove sink marks, so-called sync marks.

Further, as a result, the movable die part is on the surface facing the cavity formed when the movable die part is in the first position, and injection is possible between the first position and the second position. As long as the gate for injecting the molten resin is provided at the position, it is possible to manufacture a resin molded product having no defective appearance. Therefore, since the position of the gate for injecting the molten resin can be selected quite freely, the appearance can be improved by selecting the gate at a position where the molded product is inconspicuous.

[Brief description of drawings]

FIG. 1 is a front sectional view (a) of a mold showing a second embodiment of the present invention, a plan sectional view (b) in the III-III direction of FIG. 1 (a), and a front sectional view of a main body of the mold. It is (c).

FIG. 2 is a first view of a movable die unit according to a second embodiment of the present invention.
(A) is a front cross-sectional view of the mold showing a state in which the cavity formed when the movable mold part is in the second position is filled with the molten resin. It is a front sectional view (b) of the mold showing a filled state.

FIG. 3 is a front sectional view (a) of the mold showing the first embodiment of the present invention, a plan sectional view (b) in the I-I direction of FIG. 3 (a), and a front sectional view of the main body of the mold. It is (c).

FIG. 4 is a first view of a movable die unit according to the first embodiment of the present invention.
(A) is a front cross-sectional view of the mold showing a state in which the cavity formed when the movable mold part is in the second position is filled with the molten resin. It is a front sectional view (b) of the mold showing a filled state.

5A is a front sectional view of a mold showing a third embodiment of the present invention, FIG. 5B is a plan sectional view in the VV direction of FIG. 5A, and FIG. It is (c).

FIG. 6 is a view showing a first moving mold section according to a third embodiment of the present invention.
(A) is a front cross-sectional view of the mold showing a state in which the cavity formed when the movable mold part is in the second position is filled with the molten resin. It is a front sectional view (b) of the mold showing a filled state.

FIG. 7 is a front sectional view of a mold showing a fourth embodiment of the present invention, FIG. 7A is a plan sectional view in the VII-VII direction of FIG. 7A, and FIG. It is (c).

FIG. 8 is a first view of a movable die unit according to a fourth embodiment of the present invention.
(A) is a front cross-sectional view of the mold showing a state in which the cavity formed when the movable mold part is in the second position is filled with the molten resin. It is a front sectional view (b) of the mold showing a filled state.

FIG. 9 is a front view (a) and a side view (b) of a resin molded product obtained by a conventional manufacturing method.

FIG. 10 is a front view (a) and a side view (b) of a resin molded product obtained by a conventional manufacturing method.

FIG. 11 is a perspective view of a resin molded product obtained by a conventional manufacturing method.

[Explanation of symbols]

10, 20, 30, 40 Main body of mold 10A, 10B, 20A, 20B, 30A, 30B, 4
0A, 40B Inner wall surface facing 10C, 20C, 30C, 40C Recess 10D, 20D Inner wall surface 10E, 20E, 30E, 40E Gate 10F, 20F, 30F, 40F Inner wall surface 10G, 20G, 30G, 40G Parting line 10H , 20H, 30H, 40H Fixed side 10I, 20I, 30I, 40I Moving side 12, 22, 32, 42 Moving mold part 16, 26, 36, 46 Spring 18 Molten resin 50, 70 Flow mark 51, 61 Molten resin Injection direction 52, 62, 72 Weld line 53, 54, 63, 64 Moving direction of molten resin 65, 75 Gate position 66 Gas burn

Claims (12)

[Claims] 1. A main body of a mold in which a concave portion or an opening portion is provided in a part of the inner wall surface facing each other, and a tip end surface at a portion of the facing inner wall surface opposite to the concave portion or the opening portion. A first position in which the side surfaces substantially abut and a part of a space sandwiched between the facing inner wall surfaces is closed, and a second position in which the tip end surface is away from the first position in the direction of the recess or the opening. A movable mold part capable of moving between the positions while the side surface is in contact with an inner wall surface around the concave part or the opening part, and the tip surface of the movable mold part is in the first position. On the surface facing the cavity formed in
A mold having a gate capable of injecting a molten resin while the moving mold part moves between the first position and the second position is used, and the moving mold part is the first mold. The molten resin is injected and injected from the gate at the position of, and then the moving mold part is gradually moved to the second position according to the pressure of the molten resin in the cavity. An injection molding method in which a cavity is filled with the molten resin to obtain a molded product having a change in wall thickness. 2. A main body of a mold in which a concave portion or an opening portion is provided in a part of an inner wall surface facing each other, and a tip end surface is provided on a portion of the facing inner wall surface opposite to the concave portion or the opening portion. A first position in which the side surfaces substantially abut and a part of a space sandwiched between the facing inner wall surfaces is closed, and a second position in which the tip end surface is away from the first position in the direction of the recess or the opening. A movable mold part that is movable between the positions while the side surface is in contact with an inner wall surface around the recess or the opening, and is formed when the movable mold part is in the first position. A mold having, on a surface facing the cavity, a gate capable of injecting a molten resin while the moving mold part moves between the first position and the second position. And when the moving mold part is in the first position, Molten resin is injected and injected, and after a certain period of time, the movable mold part is moved to the second position, and as a result, the newly formed cavity is filled with the molten resin to obtain a molded product with a change in wall thickness. Injection molding method. 3. A main body of a mold in which a concave portion or an opening portion is provided in a part of the inner wall surface facing each other, and the same shape as the end surface of the concave portion or the opening portion connected to one of the inner wall surfaces facing each other. A first position at which the front end surface is located substantially at the end surface of the recess or the opening and closes one end of the recess or the opening, and the front end surface is in the recess or at the opening from the first position. A movable mold part capable of moving while contacting an inner wall surface around the concave part or the opening part with a rim of the tip surface between second positions spaced apart from each other; The molten resin is injected on the surface facing the cavity formed when the movable mold part is in the position 1 while the movable mold part moves between the first position and the second position. And a movable mold part having the first The molten resin is injected and injected from the gate at the position of, and then the moving mold part is gradually moved to the second position according to the pressure of the molten resin in the cavity. An injection molding method in which a cavity is filled with the molten resin to obtain a molded product having a change in wall thickness. 4. The same shape as the main body of the mold in which a concave portion or an opening portion is provided in a part of the facing inner wall surface and the end surface of the concave portion or the opening portion connected to one of the facing inner wall surface. A first position at which the front end surface is located substantially at the end surface of the recess or the opening and closes one end of the recess or the opening, and the front end surface is in the recess or at the opening from the first position. A movable mold part capable of moving an edge of the distal end surface while contacting an inner wall surface around the recess or the opening between second positions spaced apart from each other; and the distal end of the movable mold part. On a surface facing the cavity formed when the surface is in the first position,
A mold having a gate capable of injecting a molten resin while the moving mold part moves between the first position and the second position is used, and the moving mold part is the first mold. The molten resin is injected and injected from the gate at the position of, and after a certain period of time, the movable mold part is moved to the second position, and as a result, a cavity newly generated is filled with the molten resin. Injection molding method to obtain molded products with varying thickness. 5. The concave portion or the opening portion of the main body portion is provided around one of the facing inner wall surfaces, and the shape of the space formed by the concave portion or the opening portion and the facing inner wall surface is a peripheral portion. Is thick and the central part is thin, and the shape of the distal end surface of the movable mold part is a donut shape or a frame shape, and the movable mold part moves between the first position and the second position. When this is done, the inner peripheral edge of the tip surface contacts the inner wall surface inside the recess or the opening, and the outer peripheral edge of the tip surface contacts the inner wall surface outside the recess or the opening. The injection molding method according to claim 3. 6. A main body of a mold in which a recess or an opening is provided around one of the inner walls facing each other, and the shape of the space formed by the recess or the opening and the inner wall facing each other is box-shaped. A first position in which a tip end surface is substantially in contact with the other of the facing inner wall surfaces on the side opposite to the concave portion or the opening, and a side surface closes a space surrounded by the facing inner wall surfaces; Moving the side surface between a second position distant from the first position in the direction of the recess or the opening while the side surface contacts the edge of the inner wall surface on the side of the recess or the opening. And a movable mold part on a surface facing a cavity formed when the movable mold part is in the first position, and the movable mold part has the first position. A gate capable of injecting molten resin while moving between the second positions. Using a mold having, and injecting and injecting the molten resin from the gate when the moving mold part is in the first position, and thereafter moving the moving mold part according to the pressure in the cavity. An injection molding method in which a cavity communicating with the cavity is filled with the molten resin while moving to the second position to obtain a molded product having a change in wall thickness. 7. A main body of a mold in which a concave portion or an opening portion is provided around one of the facing inner wall surfaces, and a space formed by the concave portion or the opening portion and the facing inner wall surface is box-shaped. A first position in which a tip end surface is substantially in contact with the other of the facing inner wall surfaces on the side opposite to the concave portion or the opening, and a side surface closes a space surrounded by the facing inner wall surfaces; The surface moves between a second position, which is away from the first position in the direction of the recess or the opening, while the side surface is in contact with the peripheral edge of the facing inner wall surface on the side of the recess or the opening. A movable mold part that can be formed on the surface facing the cavity formed when the movable mold part is in the first position, It is possible to inject molten resin while moving between the position and the second position. A mold having a different gate, and injecting and injecting the molten resin from the gate when the moving mold part is at the first position, and then, after a certain time has passed, moving the mold part to the second mold. The injection molding method for obtaining a molded product having a change in wall thickness by moving the molten resin into the cavity communicating with the cavity. 8. A main body of a mold in which a concave portion or an opening portion is provided in a part of the inner wall surface facing each other, and a tip end surface at a portion of the facing inner wall surface opposite to the concave portion or the opening portion. A first position in which the side surfaces substantially abut and a part of a space sandwiched between the facing inner wall surfaces is closed, and a second position in which the tip end surface is away from the first position in the direction of the recess or the opening. A movable mold part that is movable between the positions while the side surface is in contact with an inner wall surface around the recess or the opening, and is formed when the movable mold part is in the first position. A gate on the surface facing the cavity, which is capable of injecting molten resin while the moving die moves between the first position and the second position; Means for holding the mold part in the first position; and the moving mold part in the second position. And a means for holding the moving mold part after the molten resin is injected and injected from the gate into the cavity formed when the moving mold part is in the first position. Injection mold having means for moving from a position to the second position. 9. A main body of a mold in which a concave portion or an opening portion is provided in a part of the inner wall surface facing each other, and an end surface of the concave portion or the opening portion connected to one of the inner wall surfaces facing each other have the same shape. A first position at which the front end surface is located substantially at the end surface of the recess or the opening and closes one end of the recess or the opening, and the front end surface is in the recess or at the opening from the first position. A movable mold part capable of moving while contacting an inner wall surface around the concave part or the opening part with a rim of the tip surface between second positions spaced apart from each other; The molten resin is injected on the surface facing the cavity formed when the movable mold part is in the position 1 while the movable mold part moves between the first position and the second position. And a hand that holds the movable mold part in the first position. A step, means for holding the movable mold part in the second position, and injection of the molten resin from the gate into the cavity formed when the movable mold part is in the first position. And a means for moving the movable die part from the first position to the second position after being subjected to injection molding. 10. The recess or the opening of the main body is provided around one of the facing inner wall surfaces, and the shape of the space formed by the recess or the opening and the facing inner wall is a peripheral portion. Is thick and the central portion is thin, and the shape of the distal end surface of the movable mold part is a donut shape or a frame shape, and the distal end surface is the other of the facing inner wall surfaces on the side opposite to the concave portion or the opening portion. 9. The injection mold according to claim 8, wherein the side surface closes the periphery of the space sandwiched by the facing inner wall surfaces when the side surface is in the first position in which the side surfaces substantially contact each other. 11. The recess or the opening of the main body is provided around one of the facing inner wall surfaces, and the shape of the space formed by the recess or the opening and the facing inner wall is a peripheral portion. Is thick and the central part is thin, and the shape of the distal end surface of the movable mold part is a donut shape or a frame shape, and the movable mold part moves between the first position and the second position. When doing, the inner peripheral edge of the donut-shaped or frame-shaped tip end surface contacts the inner wall surface inside the recessed portion or the opening, and the outer peripheral edge of the tip end surface of the recessed portion or the opening. The injection mold according to claim 9, which is in contact with the inner wall surface on the outer side. 12. A main body of a mold having a recess or an opening around one of the facing inner wall surfaces, and a space formed by the recess or the opening and the facing inner wall surface is box-shaped. A first position in which a tip end surface is substantially in contact with the other of the facing inner wall surfaces on the side opposite to the concave portion or the opening, and a side surface closes a space surrounded by the facing inner wall surfaces; Moving the side surface between a second position distant from the first position in the direction of the recess or the opening while the side surface contacts the edge of the inner wall surface on the side of the recess or the opening. And a movable mold part on a surface facing a cavity formed when the movable mold part is in the first position, and the movable mold part has the first position. Gate capable of injecting molten resin while moving between the second positions A means for holding the moving die part in the first position, a means for holding the moving die part in the second position, and a means for holding the moving die part in the first position. An injection molding die comprising: means for moving the moving die part from the first position to the second position after the molten resin is injected and injected from the gate into the formed cavity.