JP2011194580A - Apparatus for molding foamed resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding apparatus which can correspond to cracking and open many through-holes by a simple mechanism.SOLUTION: In the molding apparatus 1, a cavity 20 filled with a raw material is formed between a fixed mold 2 and a movable mold 3, and a pin 5 is set in the cavity 20 to move through a guide hole 21 formed in one of both molds. In one of both molds 2 and 3, an energizing mechanism 4 having a push spring 50 energizing the pin 5 toward the cavity 20 is installed. The pin 5 is set to move between a first position where the end contacts the fixed mold 2 or the movable mold 3 under pressure by the energization of the push spring 50 during the clamping of both molds 2 and 3 and a second position where the end is pushed further from the first position by the push spring 50 and contacts the fixed mold 2 or the movable mold 3 during cracking to separate the movable mold 3 from the fixed mold 2 after the mold clamping.

Description

  The present invention relates to a molding apparatus used for manufacturing a thermoplastic foamed resin molded article.

11 (a) and 11 (b) are cross-sectional views of a conventional foamed resin molding apparatus (see Patent Document 1). This comprises a fixed mold (2) and a movable mold (3) that fits the fixed mold (2), and a cavity (20) filled with foamed resin beads is formed between both molds (2) and (3). Is done. Steam chambers (25) and (35) to which heated steam is supplied are provided outside both types (2) and (3). The movable mold (3) includes a raw material filling port (10) for injecting foamed resin beads into the cavity (20) together with compressed air, and a through-hole in a molded product formed by filling the cavity (20) with foamed resin beads. The pin (5) that opens is deployed. The pin (5) can be moved in and out of the cavity (20).
At the time of molding, the fixed mold (2) and the movable mold (3) are combined, and the foamed resin beads are filled into the cavity (20) together with the compressed air from the raw material filling port (10). The steam chambers (25) and (35) are filled with heated steam, and are released from the mold after cooling with cooling water. FIG. 12 is a perspective view of the molded product (6), and the trace of the pin (5) becomes the through hole (60) of the molded product (6). The through hole (60) extends in the closing direction of the movable mold (3).

In molding such foamed resin beads, a technique called cracking is used. As shown in FIG. 11 (b), after filling the cavity (20) with foamed resin beads, the movable mold (3) is once separated from the fixed mold (2) by a distance L1 from the cavity (20). It refers to a method of creating a flow of air and filling the foamed resin beads into a place that is assumed to be difficult to fill with the foamed resin beads.
During the cracking, if the tip of the pin (5) is separated from the fixed mold (2), a through hole is not formed. Therefore, a molding apparatus is also known in which a drive mechanism composed of, for example, a rack and a pinion is provided at the base end of the pin (5), and the pin (5) further enters the cavity (20) in accordance with cracking. (See Patent Document 2).

JP 2008-207503 A JP 2008-49580 A

In a conventional molding apparatus that supports cracking, a drive mechanism that moves the pin (5) in and out of the cavity (20) in accordance with cracking is required, so that a space for providing the drive mechanism is required. Therefore, when it is necessary to open a large number of through holes, it is necessary to provide a large number of drive mechanisms, but there is a possibility that a large number of through holes cannot be opened because there is no space for the drive mechanisms. there were.
An object of the present invention is to provide a molding apparatus that can cope with cracking and can open a large number of through holes with a simple mechanism.

A cavity (20) filled with raw material is provided between the fixed mold (2) and the movable mold (3), and a pin (5) is formed in either of the molds in the cavity (20). (21) An urging mechanism provided so as to be able to protrude and retract, and an elastic member for urging the pin (5) toward the cavity (20) in either one of the molds (2) and (3) ( 4), and the pin (5) is brought into contact with the fixed die (2) or the movable die (3) with a pressing force by the urging of the elastic member when the molds (2) and (3) are clamped. A first position;
After clamping, when the movable mold (3) is cracked away from the fixed mold (2), the tip is pushed further than the first position by the elastic member to contact the fixed mold (2) or the movable mold (3). It is provided to be movable between two positions. A large number of urging mechanisms (4) are provided in the molding apparatus (1), and each elastic member is a spring (50) that urges one pin (5).

1. In the present invention, the tip of the pin (5) is fixed by the biasing mechanism (4) between the first position during normal mold clamping and the second position during cracking ( 2) or in contact with the movable mold (3). Thereby, in the molding apparatus (1) corresponding to cracking, the through-hole can be formed in the molded product with a simple mechanism that moves the pin (5) only by urging the elastic member.
Further, since the mechanism for urging the pin (5) is simple, a large number of urging mechanisms (4) can be provided in the molding apparatus (1), and a large number of through holes can be formed in the molded product. it can.
2. When a large number of urging mechanisms (4) are provided in the molding apparatus (1), the spring (50) as each elastic member urges one pin (5), that is, each pin (5) Since it is independent, even if the pin (5) is broken or damaged, the pin (5) may be replaced. This facilitates maintenance of the pin (5).

(a), (b) is sectional drawing of the shaping | molding apparatus of this example, (a) shows the time of a normal mold clamping, (b) shows the time of cracking. It is an enlarged view which shows the basic composition of the urging | biasing mechanism in a shaping | molding apparatus. (a), (b) is an expanded sectional view which shows the other Example of an urging | biasing mechanism. It is a cross-sectional enlarged view which shows the other Example of an urging | biasing mechanism. It is a cross-sectional enlarged view which shows the other Example of an urging | biasing mechanism. It is the cross-sectional enlarged view of the movable type | mold and the fixed type | mold which formed the conventional slit or recessed part. It is a cross-sectional enlarged view which shows the other Example of an urging | biasing mechanism. It is a cross-sectional enlarged view which shows the other Example of an urging | biasing mechanism. It is a cross-sectional enlarged view which shows the other Example of an urging | biasing mechanism. It is a cross-sectional enlarged view which shows the other Example of an urging | biasing mechanism. (a), (b) is sectional drawing of the conventional foaming resin shaping | molding apparatus. It is a perspective view of a molded product. It is a cross-sectional enlarged view showing another embodiment, (a) shows a normal mold clamping, (b) shows a mold opening.

First Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
1 (a) and 1 (b) are cross-sectional views of the molding apparatus (1), in which (a) shows a normal mold clamping and (b) shows a cracking time. FIG. 2 is an enlarged view of the urging mechanism (4) in the molding apparatus (1).
The molding apparatus (1) has a fixed mold (2) and a movable mold (3) as in the prior art, and a cavity (20) filled with foamed resin beads is placed between both molds (2) and (3). It is formed. Steam chambers (25) and (35) to which heated steam is supplied are provided outside both types (2) and (3). The movable mold (3) is provided with a raw material filling port (10) for injecting foamed resin beads into the cavity (20) together with the compressed air, but this may be provided in the fixed mold (2).
The pin (5) fits into the cavity (20) so that the pin (5) can be projected and retracted into the fixed mold (2), and the pin (5) is formed by filling the cavity (20) with foamed resin beads as in the conventional case. Open a through hole in the molded product. On the outside of the fixed mold (2), an urging mechanism (4) (4) is provided in the steam chamber (25), and a base end portion of the pin (5) is provided in the urging mechanism (4). Fit.

FIG. 2 shows the basic structure of the urging mechanism (4). The urging mechanism (4) is mounted on the fixed mold (2), the outer opening is closed by the cover (41), and the base end of the pin (5) is A fitting case (40), and a pressing spring (50) disposed between the cover (41) of the case (40) and the end face of the base end of the pin (5) are provided. The pin (5) is urged toward the cavity (20) by the push spring (50), passes through the guide hole (21) established in the fixed mold (2), and enters the cavity (20). . That is, the pin (5) is guided in and out by the guide hole (21).
The urging mechanism (4) and the guide hole (21) may be provided or formed in the movable mold (3) instead of the fixed mold (2). Further, the cross-sectional shape of the pin (5) is not limited to a round shape, and may be a polygon such as a triangle or a quadrangle in accordance with the shape of the through hole. Further, the pin (5) may be provided with a taper (not shown) so as to be easily separated from the molded product.

As shown in FIG. 1 (a), at the time of normal mold clamping, the pin (5) is urged by the push spring (50) and presses against the inner surface of the movable mold (3). The position of the pin (5) shown in FIG.
At the time of cracking, as described above, the movable mold (3) is separated from the fixed mold (2) by a distance L1. The pin (5) is pushed by the distance L1 by the urging force of the push spring (50) and keeps the state in contact with the inner surface of the movable die (3). The position of the pin (5) shown in FIG. That is, the pin (5) is provided so as to be movable between the first position and the second position.
After the end of cracking, return to the normal clamping position shown in FIG. In this state, when the cavity (20) is filled with foamed resin beads and cooled, a molded product is formed, and the trace of the pin (5) becomes a through hole. Thereby, a through-hole can be formed in a molded article with a simple mechanism in a molding apparatus corresponding to cracking.
As shown in FIGS. 1 (a) and 1 (b), two or many urging mechanisms (4) are provided in the steam chamber (25) on the fixed mold (2) side, and each spring (50) Energize one pin (5). That is, since each pin (5) is independent, even if the pin (5) is broken or damaged, only the pin (5) needs to be replaced. This facilitates maintenance of the pin (5).

Second Embodiment FIGS. 3 (a) and 3 (b) are enlarged cross-sectional views showing another embodiment of the urging mechanism (4). The urging mechanism (4) includes a sleeve (42) provided outside the fixed mold (2) and having a central hole (43) integrally formed with the fixed mold (2). A screw hole (44) is formed outward from the center of each. A hollow ball screw (70) is screwed into the screw hole (44), and one end of the ball screw (70) protrudes from the outside of the sleeve (42). A nut (71) is screwed into the ball screw (70) protruding outward from the sleeve (42), and the surface of the nut (71) is in contact with the outer end surface of the sleeve (42). The center hole (43) is connected to the guide hole (21) of the fixed mold (2).
The pin (5) has a large-diameter portion (51) whose tip is in contact with the inner surface (32) of the movable die (3) and extends outward from the large-diameter portion (51) and penetrates the hollow portion of the ball screw (70). A small diameter portion (52) is provided. A push spring (50) is inserted into the small diameter portion (52) between the outer end surface of the large diameter portion (51) and the inner end surface of the sleeve (42). A female screw (not shown) is formed at the center of the small diameter portion (52) that penetrates the ball screw (70), and the set screw (73) is screwed to the female screw via a stopper (72) that is a hook. To do. Since the large-diameter portion (51) is urged toward the cavity (20) by the pressing spring (50), the stopper (72) is applied to the outer end surface of the ball screw (70) and the pin (5) is required. Preventing entry into the cavity (20) beyond the distance.

Since the stopper (72) contacts the outer end surface of the ball screw (70), the large diameter portion (51) of the pin (5) depends on the length of the ball screw (70) screwed into the screw hole (44) of the sleeve (42). ) Enters the cavity (20).
That is, a sleeve (42), a ball screw (70) screwed into the sleeve (42), and a stopper that contacts the outer end surface of the ball screw (70) and restricts the progression of the pin (5) by the pressing spring (50). (72) constitutes an adjustment mechanism (7) for adjusting the length of the pin (5) entering the cavity (20).
The nut (71) is screwed onto the ball screw (70), and the nut (71) is brought into contact with the outer end surface of the sleeve (42), so that the nut (71) is placed between the outer end surface of the sleeve (42). A frictional force is generated. Thereby, the ball screw (70) is fixed and the inadvertent rotation of the ball screw (70) is restricted.
As shown in FIG. 3 (a), at the time of normal mold clamping, the pin (5) is urged by the push spring (50) and is in a first position where it is pressed against the inner surface (32) of the movable mold (3). To reach.
As shown in FIG. 3 (b), at the time of cracking, the movable mold (3) is separated from the fixed mold (2) by a distance L1 (see FIG. 1 (b)). The pin (5) is pushed by the distance L1 by the urging force of the push spring (50), and reaches the second position where the pin (5) is kept in pressure contact with the inner surface of the movable die (3). That is, even in the example shown in FIGS. 3A and 3B, the through-hole can be formed in the molded product with a simple mechanism using a molding apparatus that supports cracking.

Third Embodiment FIG. 4 is an enlarged cross-sectional view showing another embodiment of the urging mechanism (4), and shows a normal clamping state. From the inner surface of the movable mold (3), there is provided a protrusion (30) whose tip surface faces the tip surface of the pin (5), and when the mold is clamped and cracked, the protrusion (30) and the tip surface of the pin (5) Contact each other. If the pin (5) is too long, buckling may occur when the tip is pressed against the inner surface of the movable mold (3) during molding. In order to prevent this buckling, the length of the large diameter portion (51) of the pin (5) is set to about three times the diameter. The protrusion (30) shown in FIG. 4 prevents buckling when the width of the cavity (20) is long and the length of the large diameter part (51) of the pin (5) is longer than the diameter. It is valid.

Fourth Embodiment FIG. 5 is an enlarged cross-sectional view showing another embodiment of the urging mechanism (4), and shows a normal clamping state. On the inner surface of the movable mold (3), a slit or recess (31) into which the large diameter part (51) of the pin (5) is fitted is formed. During normal clamping and cracking, the tip of the large-diameter portion (51) of the pin (5) is fitted into the slit or the recess (31), and a through hole is opened in the molded product after mold release.
As shown in FIG. 5, in the configuration in which the biasing mechanism (4) is provided and the concave portion (31) is formed in the movable mold (3), the biasing mechanism (4) is not provided as shown in FIG. Compared to the conventional configuration in which the concave portion (31) is formed in the movable mold (3), there are the following advantages. In the conventional configuration shown in FIG. 6, the pin (5) of the fixed mold (2) is fitted into the recess (31) of the movable mold (3) to form a through hole of the molded product. At this time, if the fixed mold (2) and the movable mold (3) are displaced along the in-plane (arrow X direction) perpendicular to the moving direction of the movable mold (3), the pin (5) is recessed (31 If the pin (5) is detached from the inner surface of the movable die (3), the pin (5) may hit the inner surface of the movable die (3) to be broken or damaged.
As shown in FIG. 5, when the biasing mechanism (4) is provided and the pin (5) is biased by the push spring (50), the fixed mold (2) and the movable mold (3) are moved in the direction of the arrow X. Even if the pin (5) is displaced from the recess (31), the pin (5) is retracted against the push spring (50). As a result, the possibility that the pin (5) hits the inner surface of the movable mold (3) and is broken or damaged is avoided.

Fifth Embodiment FIG. 7 is an enlarged cross-sectional view showing another embodiment of the urging mechanism (4), and shows a normal clamping state. From the inner surface of the movable mold (3), a protrusion (30) whose tip surface faces the tip surface of the pin (5) is provided, but the inner surface (32) of the movable mold (3) is provided on the pin (5). It is inclined compared to the direction of the appearance of. Therefore, the through hole of the molded product extends with an inclination with respect to the outer surface of the molded product. That is, the through hole can be formed regardless of the outer shape of the molded product.
In addition, as shown in FIG. 8, a slit or a recess (31) can be formed on the inner surface of the movable mold (3) instead of the protrusion (30).

Sixth Embodiment FIG. 9 is an enlarged cross-sectional view showing another embodiment of the urging mechanism (4), and shows a normal clamping state. In this example, the sleeve (42) is provided separately from the fixed mold (2), and the center hole (43) of the sleeve (42) is aligned with the guide hole (21) of the fixed mold (2). When the sleeve (42) is damaged during molding, it is sufficient to replace only the sleeve (42), and maintenance of the molding apparatus (1) is facilitated.

Seventh Embodiment FIG. 10 is an enlarged cross-sectional view showing another embodiment of the urging mechanism (4), and shows a normal clamping state. In this example, the sleeve (42) is provided separately from the fixed mold (2), but in addition, the central hole (43) is formed to have a large diameter, and the inner side of the central hole (43). Place pin (5) on The pin (5) is formed hollow and fitted into the guide hole (21), and a retaining flange (53) is provided outside the base end of the pin (5). A guide rod (45) provided with a threaded portion is screwed onto the outer end surface of the sleeve (42), and the push spring (50) is fitted to the tip of the guide rod (45). On the outside of the sleeve (42), the nut (71) is screwed into the threaded portion of the guide rod (45) to restrict inadvertent rotation of the guide rod (45). That is, in the example shown in FIG. 10, the adjusting mechanism (7) is not provided.
The inner side of the pin (5) is pushed by the push spring (50), and the tip is in contact with the movable die (3). During normal mold clamping, the flange (53) is separated from the fixed mold (2), and during cracking, the flange (53) is pressed by the pressing spring (50) to contact the fixed mold (2). When the pin (5) is broken during molding, it is sufficient to remove the sleeve (42) and replace only the pin (5), and maintenance of the molding device (1) is facilitated.

Eighth Embodiment FIGS. 13A and 13B are enlarged cross-sectional views showing another embodiment . FIG. 13A shows a normal mold clamping and FIG. 13B shows a mold opening. In this example, the urging mechanisms (4) and (4) are provided in both the fixed mold (2) and the movable mold (3), and the pins (5) of the urging mechanisms (4) and (4) are clamped at the time of mold clamping. ) The tip of (5) is aligned. At the time of cracking, the movable die (3) is fixed to the fixed die (2) until the tips of the pins (5) and (5) of the biasing mechanisms (4) and (4) are in contact with each other rather than the position shown in FIG. ) The trace of both pins (5) and (5) becomes the through hole (60) (see FIG. 12) of the molded product (6). That is, in this example, one pin (5) is brought into contact with the tip of the other pin (5) with a pressing force by the biasing force of the push spring (50) when both molds are clamped. At the time of cracking, the tip end portion is further pushed by the push spring (50) than the first position at the time of cracking and moves between the second position contacting the tip end portion of the other pin (5).
If the molded product (6) is thick and the through-hole (60) has a long penetration length, the pin (5) of the biasing mechanism (4) will be used to form the through-hole (60). (5) is long and may be damaged during molding. As shown in FIGS. 13 (a) and 13 (b), the two pins (5) and (5) are brought into contact with each other to form a through hole (60), so that the pins (5) and (5) are damaged during molding. This reduces the possibility of doing so.

The molding apparatus according to this example has the following advantages.
1. In the present invention, the tip of the pin (5) is fixed by the biasing mechanism (4) between the first position during normal mold clamping and the second position during cracking ( 2) or in contact with the movable mold (3). Thereby, a through-hole can be formed in a molded article with a simple mechanism in the molding apparatus (1) corresponding to cracking.
2. Further, since the mechanism for urging the pin (5) is simple, a large number of urging mechanisms (4) can be provided in the molding apparatus (1), and a large number of through holes can be formed in the molded product. it can.
Further, although the urging mechanism (4) is provided in the steam chamber (25), since the mechanism is simple, it does not occupy much space in the steam chamber (25). Thus, the flow of steam and / or cooling water in the steam chamber (25) is not disturbed, and the molding cycle is not hindered.
3. When a number of biasing mechanisms (4) and (4) are provided in the molding apparatus (1), each spring (50) biases one pin (5), that is, each pin (5) is independent. Therefore, even if the pin (5) is broken or damaged, the pin (5) may be replaced. This facilitates maintenance of the pin (5).

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof. In addition, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims.
In the above description, the elastic member is the push spring (50), but other substitutes such as a leaf spring can be used as long as the elastic member can withstand the temperature and humidity in the steam chamber (25).
Further, the pin (5), the sleeve (42), and the stopper (72) may be made of aluminum, brass, stainless steel or the like, and may be coated with Teflon (registered trademark). The material is not limited to these. Furthermore, the push spring (50) is made of stainless steel, spring steel or the like, but stainless steel is preferred from the viewpoint of rust prevention and the like.

(1) Molding equipment
(2) Fixed type
(3) Movable type
(4) Energizing mechanism
(5) Pin
(7) Adjustment mechanism
(20) Cavity
(50) Push spring

Claims (10)

A cavity filled with the raw material is provided between the fixed mold and the movable mold, and a pin is provided in the cavity so that it can protrude and retract through a guide hole formed in either mold. Either one is provided with an urging mechanism having an elastic member that urges the pin toward the cavity, and the pin is fixed or movable by the urging of the elastic member when clamping both molds. A first position that contacts with a pressing force;
After the mold clamping, when the movable mold is cracked away from the fixed mold, the tip is pushed further than the first position by the elastic member so that it can move between the second position contacting the fixed mold or the movable mold. A molding apparatus characterized by comprising: 2. The molding apparatus according to claim 1, wherein a plurality of biasing mechanisms are provided in the molding apparatus, and each elastic member is a spring that biases one pin. The molding apparatus according to claim 1, wherein the urging mechanism includes an adjustment mechanism that regulates an entry length of the pin into the cavity. The adjustment mechanism is mounted on the outside of the fixed type or movable type, and is attached to a sleeve having a screw hole formed in the center, a ball screw threaded into the screw hole and passing through the pin, and a pin passing through the ball screw. The molding apparatus according to claim 3, further comprising a stopper that is in contact with an outer end surface of the ball screw and restricts the progress of the pin by the elastic member. The molding apparatus according to any one of claims 1 to 4, wherein a protrusion with which a tip end portion of the pin contacts is formed on an inner surface of either the fixed mold or the movable mold. The molding apparatus according to any one of claims 1 to 4, wherein a slit or a recess into which a tip of the pin is fitted is formed on an inner surface of either the fixed mold or the movable mold. The molding apparatus according to claim 5 or 6, wherein an inner surface of either the fixed mold or the movable mold is inclined with respect to a protruding and retracting direction of the pin. The molding apparatus according to claim 4, wherein the sleeve of the adjustment mechanism is provided separately from the fixed type or the movable type and is exchangeable. The molding device according to claim 1 or 2, wherein the pin is fitted in the guide hole in a replaceable manner. A cavity filled with the raw material is provided between the fixed mold and the movable mold, and a pin is provided in the cavity so as to be able to protrude and retract through the guide holes formed in both molds. An urging mechanism having an elastic member for urging the pin toward the cavity is provided, and when one of the pins is clamped, the tip of the pin comes into contact with the other pin by pressing force due to the urging of the elastic member. A first position;
After the mold clamping, when the movable mold is cracked away from the fixed mold, the tip is pushed further than the first position by the elastic member so that the movable mold is movable between the second position contacting the partner pin. A molding apparatus characterized by comprising:

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