JP2013086151A - Vacuum molding die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure reducing molding die capable of positively maintaining a degree of pressure reduction in a cavity by positively abutting and sealing both ends of a second seal member with respect to a first seal member by a simple structure.SOLUTION: The vacuum molding die includes a lower die 1, an upper die 2, a slide 3, the first seal member 4, and the second seal member 5 having an end 5a abutted on a seal surface 40 of the first seal member 4. A molding material is injected and filled in a state of the cavity 6 being reduced in pressure. At least the seal surface 40 of the first seal member 4 is molded in a planar state, or a second seal member 5 is molded to have a rectangular cross section. At least the end 5a of the second seal member 5 abutted on the first seal member 4 is composed of an elastic body softer than the first seal member 4.

Description

  The present invention relates to a reduced pressure mold, and in particular, a first mold and a second mold that are provided so as to be capable of opening and closing each other, and a direction different from the opening and closing directions of the first mold and the second mold. A slide to be moved; a first seal member that seals a mold-matching surface of the first mold, the second mold, and the slide; and an end of the first seal member that is in contact with the first seal member A molding die and a second sealing member that seals the die mating surface of the second molding die and the slide, and molding is performed in a state where the inside of the cavity formed by the first molding die, the second molding die, and the slide is decompressed. The present invention relates to a vacuum forming die for injection filling a material.

  In die-cast molding, in order to improve the casting quality by suppressing the air entrainment of the melt, which is a molding material, a reduced-pressure die casting method has been used in which the melt is injected and filled into the cavity while the cavity of the mold is decompressed. It has been broken. In the molding die (decompression molding die) used for this reduced pressure die casting, in order to maintain the degree of decompression without air leaking into the cavity from outside the molding die when the inside of the cavity is decompressed, It is known to provide a sealing member on the mold matching surface.

  By the way, in the reduced pressure mold, depending on the shape of the product to be molded and the like, as shown in FIGS. 6 to 8, the first mold 1 and the second mold 2 are opened and closed opposite to each other. Some have the slide 3 moved in a direction X different from the direction Y. In this case, a first seal member 4 is provided to seal the mold-matching surfaces of the first mold 1, the second mold 2 and the slide 3, and the mold of the second mold 2 and the slide 3. A second seal member 5 is provided for sealing the mating surfaces, and the second seal member 5 is connected to the end portion 5a by contacting the end surface 5a with the seal surface 40 of the first seal member 4. It is comprised so that between the sealing surfaces 40 may be sealed. As a conventional technique of such a pressure-reducing mold, for example, it is disclosed in Patent Document 1.

  In Patent Document 1, a seal ring (first seal member) is provided between a fixed mold (first mold) and a movable mold (second mold), and a movable core (slide) and a movable mold are provided. In the meantime, it is disclosed that a U-shaped seal member (second seal member) is disposed so that both ends are exposed on the surface of the moving core that contacts the movable mold. And in patent document 1, when a fixed type | mold, a moving type | mold, and a moving core are match | combined, it describes that the both ends of a sealing member make a closed curve by overlappingly connecting (contact | abutting) a seal ring. Has been. The first seal member and the second seal member are generally made of an elastic body such as rubber, and so-called O-rings having the same rubber hardness and the same diameter and a circular cross section are used.

JP-A-2005-219918

  However, as shown in FIG. 9 (a partially enlarged cross-sectional view showing the first seal member 4 ′ extending perpendicularly to the paper surface), the second seal member 5 ′ generally has a predetermined length. The end face is not flat. Therefore, in Patent Document 1, when the fixed mold, the movable mold, and the movable core are brought into contact with each other, both ends (5a ′) of the seal member (second seal member 5 ′) and the seal ring ( It is difficult to reliably connect the sealing surface 40 ') of the first seal member 4', and air etc. leaks into the cavity from the gap formed between the two 5a 'and 40', so the degree of decompression is maintained. There was a problem that it was difficult to do.

  In general, the seal member ages as the number of moldings increases, and contracts with the aging. In Patent Document 1, both the seal ring (first seal member 4 ′) and the seal member (second seal member 5 ′) have a circular cross section, the same diameter, and the same rubber hardness. Therefore, the contact area between the both end portions (5a ′) of the seal member (second seal member 5 ′) and the seal ring (the seal surface 40 ′ of the first seal member 4 ′) is small. When the second seal member 5 ′) contracts, both ends (5a ′) of the seal member (second seal member 5 ′) and the seal ring (the seal surface 40 ′ of the first seal member 4 ′) are securely connected. There was a problem that would be a difficult situation. In the mold disclosed in Patent Document 1, in order to prevent such a situation, it is troublesome to perform maintenance, such as monitoring the shrinkage of the seal member and replacing it when necessary. There was a problem.

  The present invention has been made in view of the above-described problems, and with a simple configuration, the both ends of the second seal member are securely brought into contact with the first seal member for sealing, thereby reducing the degree of decompression in the cavity. An object of the present invention is to provide a reduced pressure molding die that can be reliably maintained, and that can reliably suppress air entrainment of the molten metal and improve casting quality.

In order to achieve the above object, the first aspect of the present invention provides a first mold and a second mold that can be opened and closed opposite to each other, and an opening and closing direction of the first mold and the second mold. A slide moved in a different direction, a first seal member that seals a mold-matching surface of the first mold, the second mold, and the slide, and an end portion that is in contact with the first seal member A first sealing die and a second sealing member for sealing a die-mating surface between the second molding die and the slide, and the inside of the cavity formed by the first molding die, the second molding die, and the slide is depressurized. A pressure-reducing mold that injects and fills a molding material in a state, wherein at least the seal surface of the first seal member is molded into a flat shape, or the second seal member is molded into a rectangular cross section; At least the second of the two seal members End that is in contact with the sealing member, it is characterized in that is constituted by a soft elastic body as compared with the first seal member.
In order to achieve the above object, according to a second aspect of the present invention, in the first aspect of the present invention, the width of the first seal member is formed to be larger than the width of the second seal member. It is a feature.
In order to achieve the above object, according to a third aspect of the present invention, in the invention according to any one of the first and second aspects, at least an end portion of the second seal member in contact with the first seal member is a rubber. Hardness Hs (Asuka C) = 50 or less.
In order to achieve the above object, the invention according to claim 4 includes a first mold and a second mold that are provided to be openable and closable opposite to each other, and an opening and closing direction of the first mold and the second mold. A slide moved in a different direction, a first seal member that seals a mold-matching surface of the first mold, the second mold, and the slide, and an end portion that is in contact with the first seal member A first sealing die and a second sealing member for sealing a die-mating surface between the second molding die and the slide, and the inside of the cavity formed by the first molding die, the second molding die, and the slide is depressurized. A pressure-reducing mold that injects and fills a molding material in a state, wherein at least the seal surface of the first seal member is molded into a flat shape, or the second seal member is molded into a rectangular cross section; The width of one seal member is the second seal And it is characterized in that it is formed to be larger than the width of the wood.
According to a fifth aspect of the present invention, in order to achieve the above object, in the fourth aspect of the present invention, an end of the second seal member extends in the width direction of the first seal member. An abutting portion to be abutted on is formed.

According to the first aspect of the present invention, at least one of the first seal member is formed into a cross-sectional shape such that the seal surface is flat, or the second seal member is formed into a cross-sectional rectangle. Further, at least both end portions of the second seal member that are in contact with the first seal member are made of an elastic body that is softer than the first seal member, so that the respective molds are matched to each other to form the second seal member. When the both end portions of the first seal member are brought into contact with the first seal member, the end portion of the second seal member is not crushed and a gap is not generated. It is possible to maintain a reduced pressure in the cavity by securely sealing the gap.
According to the invention of claim 2, in the invention of claim 1, when the respective molds are matched by molding so that the width of the first seal member is larger than the width of the second seal member. In addition, since both end faces of the second seal member are securely brought into contact with the seal face of the first seal member, the gap between the first seal member and the end of the second seal member is securely sealed. The degree of vacuum can be maintained.
According to the invention of claim 3, in the invention according to claim 1 or 2, at least an end portion of the second seal member in contact with the first seal member has a rubber hardness Hs (ascii). C) = 50 or less, so that when the respective molds are matched and both end portions of the second seal member are in contact with the first seal member, the end portions of the second seal member are reliably crushed and gaps It is possible to realize that the degree of decompression in the cavity is maintained by reliably sealing between the first seal member and the end of the second seal member. Note that at least the end of the second seal member that is in contact with the first seal member can be made of foamed rubber having discontinuous bubbles.
According to the invention of claim 4, at least one of the first seal member is formed in a cross-sectional shape such that the seal surface is flat or the second seal member is formed in a cross-sectional rectangle is employed. Further, by forming the first seal member so that the width of the first seal member is larger than the width of the second seal member, the molds are matched to each other and both end portions of the second seal member are brought into contact with the first seal member. When this is done, both end surfaces of the second seal member are surely brought into contact with the seal surface of the first seal member, so that the gap between the first seal member and the end of the second seal member is securely sealed. The degree of decompression can be maintained. In addition, as for the 2nd seal member, it is desirable for the peripheral corner | angular part of the end surface to be chamfered.
According to the invention of claim 5, in the invention of claim 4, the end of the second seal member extends in the width direction of the first seal member and abuts against the first seal member. By forming the portions, when the molds are matched, the contact portion of the second seal member is surely contacted with the first seal member, and no gap is formed. It is possible to maintain the degree of decompression in the cavity by reliably sealing between the ends of the two seal members.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a first embodiment showing an enlarged main portion for explaining a vacuum forming die according to the present invention. FIG. 5 is a cross-sectional view of a second embodiment showing an enlarged main part for explaining a vacuum forming die according to the present invention. It is an expanded sectional view of the principal part shown in order to demonstrate the modification of 2nd embodiment shown in FIG. FIG. 4 is an enlarged cross-sectional view of a main part shown to explain a state where the mold is clamped from the state of FIG. 3 and the end of the second seal is in contact with the first seal member. FIG. 4 is a cross-sectional view of a third embodiment showing an enlarged main portion for explaining a vacuum forming die according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal front view conceptually shown to explain an outline of a vacuum forming die according to the present invention. FIG. 7 is a plan view showing a state where the second mold shown in FIG. 6 is removed in order to explain the outline of the vacuum mold according to the present invention. FIG. 7 is a side view showing the second mold in a longitudinal section while removing the slide of FIG. 6 in order to explain the outline of the vacuum mold according to the present invention. It is sectional drawing which expanded and showed the principal part, in order to demonstrate the conventional pressure-reduction-molding die. It is the graph which each showed the change (leak rate) of the pressure reduction degree with time passage at the time of making the end face of the 2nd seal member of different cross-sectional shape and hardness contact with the 1st seal member of circular section. . It is the graph which each showed the change (leak rate) of the pressure reduction degree with time passage when the end faces of the second seal members having different cross-sectional shapes and hardnesses are in contact with the first seal member having a rectangular cross section. . It is the graph which showed the leak rate at the time of changing the hardness of a 2nd seal member with respect to a 1st seal member (hardness Hs = 55).

First, one embodiment of the basic configuration of the pressure-reducing mold of the present invention will be described with reference to FIGS. The basic configuration of the reduced pressure mold described here can be used in common for each embodiment of the main part of the present invention described below, unless otherwise specified. In the drawings, the same reference numerals denote the same or corresponding parts.
The reduced-pressure molding die of the present invention generally includes a first molding die 1 and a second molding die 2 that are provided so as to be openable and closable with each other, and the opening and closing directions of the first molding die 1 and the second molding die 2. The slide 3 that is moved in different directions, the first seal member 4 that seals the mold-matching surfaces of the first mold 1 and the second mold 2, and the end 5 a against the first seal member 4 A first sealing die, a second molding die, and a second sealing member that seals a mold-matching surface between the slide and the first molding die, the second molding die, and the slide. The molding material is injection-filled in a state where the inside of the cavity 6 formed by 3 is decompressed.

  The first mold 1 and the second mold 2 in this embodiment are composed of a lower mold and an upper mold. In the following description, the first mold is referred to as the lower mold 1 and the second mold is referred to as the upper mold 2, but the first and second molds 1 and 2 are, for example, horizontal in the opening and closing direction. Depending on the arrangement, there may be cases other than the lower mold and the upper mold. The lower mold 1 in the embodiment shown in FIGS. 6 to 8 has a cavity surface for forming the cavity 6, which is the upper surface of the lower mold 1 opened and closed by the upper mold 2. 1a and the side surface 1b of the lower mold 1 opened and closed by the slide 3 are open.

  The upper mold 2 is formed in a substantially plate shape having a size that can cover the lower mold 1 and the slide 3. In this embodiment, the upper mold 2 is supported by a mold opening / closing means such as a mold clamping ram, and the upper mold 2 moves up and down so that the upper mold 2 approaches (mould closes) and moves away (mould open). It is configured to be possible. Therefore, the opening / closing direction of the upper mold 2 with respect to the lower mold 1 is a vertical direction as indicated by an arrow Y in FIG.

  The slide 3 is formed in a substantially plate shape having a size capable of covering the side opening portion of the cavity surface of the lower mold 1. The slide 3 is supported by a slide opening / closing means such as a slide mold clamping ram, and is arranged in the horizontal direction in FIG. 6 so that the slide 3 approaches (closes) and retracts (opens) from the lower mold 1. It is configured to be movable. Therefore, the opening / closing direction of the slide 3 with respect to the lower mold 1 is a horizontal direction as indicated by an arrow X in FIG. Further, the slide 3 is set so that the upper surface 3a thereof becomes the same height as the upper surface 1a of the lower mold when the mold is matched with the lower mold 1.

  In this embodiment, an annular groove 20 for accommodating the first seal member 4 on the lower surface of the upper mold 2 is formed so as to surround the upper open portion of the cavity surface. The first seal member 4 is formed in an annular shape corresponding to the annular groove 20. Since the lower mold 1 and the upper surfaces 1a and 3a of the slide 3 are brought into contact with the seal surface 40 of the first seal member 4 provided in the upper mold 2, they are formed smoothly. The first seal member 4 in the embodiment shown in FIG. 1 has a rectangular cross section, and the seal surface 40 that contacts the lower mold 1 and the upper surfaces 1a and 3a of the slide 3 is flat. However, as will be described in the examples described later, the first seal member 4 according to the present invention includes a case where the first seal member 4 is formed in a circular cross section.

  On the other hand, in this embodiment, a U-shaped groove 30 for accommodating the second seal member 5 is formed on the side surface facing the lower mold 1 of the slide 3 so as to surround the side opening portion of the cavity surface. The second seal member 5 is formed in a U shape corresponding to the U-shaped groove 30. Since the side surface 1b facing the slide 3 of the lower mold 1 is brought into contact with the seal surface 50 of the U-shaped second seal member 5, it is formed smoothly. Then, the second seal member 5 is slid so that the end 5a abuts against the seal surface 40 of the first seal member 4 when the lower mold 1 and the slide 3 and the upper mold 2 are aligned. 3 is formed so as to protrude by a predetermined length (for example, 1 to 2 mm) from the open end of the U-shaped groove 30 located on the upper surface 3a. In the second seal member 5 in this embodiment, as will be described in an example to be described later, the cross section is formed into a rectangular shape, and the seal surface 50 in contact with the side surface 1b of the lower mold 1 is flat. However, as will be described in the examples described later, the second seal member 5 according to the present invention includes a case where the second seal member 5 is formed in a circular cross section.

  The pressure-reducing mold configured as described above is such that the slide 3 is brought close to the lower mold 1 by the slide opening / closing means, and the side surface 3b is matched with the side surface 1b of the lower mold 1, and the upper mold 2 is opened by the mold opening / closing means. Is placed close to the lower mold 1 and the slide 3 and the upper surface 1a of the lower mold 1 and the upper surface 3a of the slide 3 are matched to each other, thereby sealing the respective mold matching surfaces and forming the cavity 6 inside. The As shown in FIGS. 6 and 8, the pressure reducing mold is provided with a passage 7 connected to the pressure reducing means so as to communicate with the cavity 6, and a predetermined amount of molten metal (molten metal) is injected. A plunger device (not shown) for filling is connected, and the molten metal is injected and filled into the cavity 6 in a state where the inside of the cavity 6 is decompressed by the decompression means via the passage 7, thereby forming a predetermined shape. Mold the product.

Next, a first embodiment of the main part of the pressure-reducing mold according to the present invention will be described in detail with reference to FIG. 1 is a partially enlarged cross-sectional view of the upper mold 2 and the slide 3, in which the first seal member 4 extends perpendicularly to the paper surface, and the lower mold 1 is hidden behind the slide 3 and cannot be seen. It has become.
The decompression molding die in this embodiment is roughly configured such that at least the seal surface 40 of the first seal member 4 is formed into a flat shape, or the second seal member 5 is formed into a rectangular cross section. The end 5 a of the seal member 5 that is in contact with at least the first seal member 4 is made of a soft elastic body as compared with the first seal member 4.

  In this embodiment, the annular first seal member 4 has a rectangular cross section. Therefore, the sealing surface 40 for the lower mold 1 of the first seal member 4 and the upper surfaces 1a and 3a of the slide 3 is formed in a flat shape. On the other hand, at least an end portion (a portion from the two-dot chain line in FIG. 1 to the tip portion) 5a of the U-shaped second seal member 5 that is in contact with the first seal member 4 is formed in a circular or rectangular cross section. The first seal member 4 is made of a soft material. In addition, the 1st seal member 4 can be comprised, for example by fluororubber, silicon rubber, etc. as an elastic body, and can set it as rubber hardness Hs = 55-80. Further, the intermediate portion other than the tip portion 5a of the second seal member 5 can be made of the same material and the same rubber hardness as the first seal member 4, and the cross section is circular in the same or different manner from the tip portion 5a. Or it can be formed into a rectangle. And about the part 5a of the front-end | tip of the 2nd sealing member 5, it can comprise, for example by adhere | attaching the foaming rubber | gum which has a discontinuous bubble on the intermediate part mentioned above, and rubber hardness is set as the hardness. Hs (Asuka C) can be set to 20 to 50. Note that the present invention is not limited to the configuration in which only the tip portion 5a of the second seal member 5 is made of a soft elastic body as compared with the first seal member 4 as described above. The whole can be configured by a soft elastic body as compared with the first seal member 4. Further, the present invention is not limited to the above-described embodiment, and as will be described in the examples described later, the cross section of the annular first seal member 4 is formed into a circular shape, and a U-shaped first shape is used. The case where at least the tip 5a of the two seal member 5 is formed into a rectangular cross section is also included. That is, when the sealing surface 40 of the annular first seal member 4 is formed into a flat shape, the U-shaped second seal member 5 may be circular in cross section, and the U-shaped second seal member 5 may be rectangular in cross section. In this case, the sealing surface 40 of the first seal member 4 does not have to be formed into a flat shape, and further, the sealing surface 40 of the annular first seal member 4 is formed into a flat shape and is U-shaped. The shaped second seal member 5 can also be formed into a rectangular cross section. In any case, the width (diameter) of the first seal member 4 is set to be larger than the diameter (width) of the second seal member 5.

  In the pressure reducing mold configured in this way, when the slide 3 is brought close to the lower mold 1 and its side surface 3b is matched with the side surface 1b of the lower mold 1, the U shape of the U-shaped second seal member 5 is obtained. The portion accommodated in the groove 30 seals the die-matching surface between the side surface 1 b of the lower mold 1 and the side surface 3 b of the slide 3. At this time, both ends 5a of the U-shaped second seal member 5 protrude upward from the U-shaped groove 40 by a predetermined length (for example, about 1 to 2 mm). Next, when the upper die 2 is lowered and die-matched with the lower die 1 and the slide 3, the annular first seal member 4 is die-matched between the lower die 1, the upper surfaces 1 a and 3 a of the slide, and the lower surface of the upper die 2. The surface will be sealed. At this time, both end portions 5 a of the U-shaped second seal member 5 are brought into contact with the seal surface 40 of the first seal member 4.

  Here, in the embodiment shown in FIG. 1, when the seal surface 40 of the first seal member 4 is formed in a flat shape, the end of the second seal member of the seal surface 40 of the first seal member 4. The area with which the end surface of the portion 5a abuts increases. Further, when the second seal member 5 is formed in a rectangular cross section, even if the width is the same as the diameter of the second seal member 5 having a circular cross section, the end surface of the end portion 5a of the second seal member 5 The area contact | abutted with respect to the sealing surface 40 of the 1st seal member 4 increases. Further, the end portions 5a of the U-shaped second seal member 5 are made of a soft elastic body as compared with the first seal member 4, so that the end surface of the end portion 5a of the fifth seal member is the first. The one seal member 4 is elastically deformed so as to be brought into contact with the seal surface 40 and crushed, thereby being brought into close contact with each other. And when it shape | molds so that the width | variety (diameter) of the sealing surface 40 of the 1st seal member 4 may become larger than the diameter (width | variety) of the 2nd seal member 5, it will be crushed by contact | abutting. The area of the end portion 5a of the second seal member 5 elastically deformed to the seal surface 40 of the first seal member 4 further increases. As a result, even when the end surface of the second seal member 5 is not flat (see FIG. 9), there is no gap between the first seal member 4 and the seal surface 40. Therefore, the cavity 6 The degree of decompression can be maintained by preventing air and the like from leaking inside.

  Even if the first seal member 4 is formed into a circular cross section and the seal surface 40 is not flat, the second seal member can be formed by forming the cross section of the second seal member 5 into a rectangular shape. 5 is formed of an elastic body made of a softer material than the first seal member 4, the end portion 5 a is brought into contact with the non-planar seal surface 40 of the first seal member 4 and its curved surface. Accordingly, there is no gap between the seal surface 40 of the first seal member 4 and the end surface of the second seal member 5, so that air or the like leaks into the cavity 6. The degree of vacuum can be maintained.

Next, a second embodiment of the main part of the pressure-reducing mold according to the present invention will be described in detail with reference to FIGS. Parts that are the same as or correspond to those in the above-described embodiment are denoted by the same reference numerals, description thereof is omitted, and only different parts are described.
The reduced pressure molding die in this embodiment is roughly configured such that at least the seal surface 40 of the first seal member 4 is formed into a flat shape or the second seal member 5 is formed into a rectangular cross section. 4 is formed to be wider than the width of the second seal 5.

  As in the first embodiment described above, the first seal member 4 in this embodiment is annular and has a rectangular cross section, and is in contact with the lower mold 1 and the upper surfaces 1a and 3a of the slide 3. The sealing surface 40 is flat. And the 1st seal member 4 in this embodiment is also set so that the width | variety (diameter) may become larger than the diameter (width | variety) of the 2nd seal member 5 similarly to 1st embodiment mentioned above. ing. However, in the first seal member 4 in this embodiment, the width of the seal surface 40 is further larger (wider) than in the first embodiment described above. In other words, the width (diameter) of the first seal member 4 in the first embodiment described above is larger than the diameter (width) of the second seal member 5, but this second embodiment. The width of the seal surface 40 is smaller (narrower) than that. As will be described in the examples described later, the present invention also includes the first seal member 4 having a circular cross section, as in the first embodiment.

  Further, the second seal member 5 in the second embodiment also has its end 5a on the seal surface 40 of the first seal member 4 when the lower mold 1 and the slide 3 and the upper mold 2 are matched. The U-shaped groove 30 located on the upper surface 3a of the slide 3 is shaped so as to protrude by a predetermined length (for example, about 1 to 2 mm) so as to come into contact. In the second embodiment, the second seal member 5 has a rectangular cross section including its end face, or a circular cross section, as will be described in the following embodiments. It is the same.

  In the pressure reducing mold configured in this way, when the slide 3 is brought close to the lower mold 1 and its side surface 3b is matched with the side surface 1b of the lower mold 1, the U shape of the U-shaped second seal member 5 is obtained. The portion accommodated in the groove 30 seals the die-matching surface between the side surface 1 b of the lower mold 1 and the side surface 3 b of the slide 3. At this time, both ends 5a of the U-shaped second seal member 5 protrude upward from the U-shaped groove 30 by a predetermined length. Next, when the upper die 2 is lowered and die-matched with the lower die 1 and the slide 3, the die-matching surface is sealed by the annular first seal member 4.

  At this time, both ends 5a of the U-shaped second seal member 5 come into contact with the seal surface 40 of the first seal member 4, but the annular first seal member 4 has a width ( The seal surface of the first seal member 4 with which the end portion 5a of the second seal member 5 is in contact is formed by the diameter (diameter) being larger (wider) than the diameter (width) of the second seal 5. 40, even when the end surface of the second seal member 5 is not flat, the wide seal surface 40 of the first seal member 4 sufficiently covers the portions of the both ends 5a of the abutted second seal member 5. In order to tightly enclose (see FIG. 4), there is no gap between the first seal member 4 and the sealing surface 40, and therefore, air is prevented from leaking into the cavity 6 to reduce the pressure. The degree can be maintained.

  Here, FIG. 3 shows a modification of the above-described second embodiment. In this modification, the peripheral corner 5b of the end surface of the second seal member 5 that is in contact with the seal surface 40 of the first seal member 4 is chamfered. Therefore, when the molds 1, 2, and 3 are matched to each other and the end portion 5 a in which the peripheral corner portion 5 b of the end surface of the second seal member 5 is chamfered is brought into contact with the seal surface 40 of the first seal member 4. As shown in FIG. 4, the seal surface 40 of the first seal member 4 is in close contact with the end surface of the second seal member 5, so that there is a gap between the seal surface 40 and the first seal member 4. Therefore, air is prevented from leaking into the cavity 6 and the degree of decompression can be maintained.

Next, a third embodiment of the reduced pressure molding die of the present invention will be described with reference to FIG. Parts that are the same as or correspond to those in the above-described embodiment are denoted by the same reference numerals, description thereof is omitted, and only different parts are described.
In addition to the second embodiment described above, the decompression mold in this embodiment generally extends to the end portion 5a of the second seal member 5 in the width direction of the first seal member 4, and this first mold. A contact portion 55 that is in contact with the seal surface 40 of the seal member 4 is formed.

  Also in the third embodiment, similarly to the second embodiment, the first seal member 4 has a rectangular cross section, and the seal surface 40 is flat. In the case of the embodiment shown in FIG. 5, the width of the first seal member 4 is set in the same manner as in the first embodiment shown in FIG. On the other hand, the second seal member, except for the end portion 5a provided with the contact portion 55, has a cross-sectional shape that is rectangular or circular as in the above-described embodiment, and the diameter (width) of the second seal member is the first. It is set smaller (narrower) than the width (diameter) of one seal member 4. The contact portion 55 provided at the end portion 5a of the second seal member 5 projects in the width direction so as to have the same length as the width of the first sheet member 4 from other portions. In addition, when the cross-sectional shape of parts other than the contact part 55 of the 2nd seal member 5 is a rectangle, the cross section (vertical cross section in FIG. 5) shape of the contact part 55 may be made into a rectangle or a circle, and a 2nd seal member may be sufficient as it. When the cross-sectional shape of the portion other than the contact portion 55 of 5 is circular, the contact portion 55 may be circular or rectangular in cross section, but the ground contact area with respect to the seal surface 40 of the first seal member 4 is increased. A rectangular cross section is desirable. A concave portion 30 a is formed at the upper end portion of the U-shaped groove 30 that accommodates the second seal member 5 of the slide 3 in this embodiment so as to correspond to the contact portion 55 of the second seal member 5.

  In the pressure reducing mold configured in this way, when the slide 3 is brought close to the lower mold 1 and its side surface 3b is matched with the side surface 1b of the lower mold 1, the U shape of the U-shaped second seal member 5 is obtained. The portion accommodated in the groove 30 seals the die-matching surface between the side surface 1 b of the lower mold 1 and the side surface 3 b of the slide 3. At this time, the contact portions 55 of the both end portions 5 a of the U-shaped second seal member 5 extend in the horizontal direction along the side surface of the lower mold 1, and the upper surface thereof extends from the recess 30 a of the U-shaped groove 30. It protrudes upward by a predetermined length. Next, when the upper die 2 is lowered and matched with the lower die 1 and the slide 3, the annular first sealing member 4 seals the upper surfaces 1a and 3a.

  At this time, the contact portions 55 of the both end portions 5a of the U-shaped second seal member 5 are brought into contact with the seal surface 40 of the first seal member 4, but the annular first seal member 4 is The width (diameter) of the second seal 5 is formed so as to be larger (wider) than the diameter (width) of the portion other than the contact portion 55, and both ends of the U-shaped second seal member 5. Since the contact portion 55 of the portion 5a protrudes from the other portion so as to extend in the width direction of the seal surface 40 of the first seal member 4, the contact area of the second seal member 5 with the seal surface 40 further increases. In addition, there is no gap between the first seal member 4 and the seal surface 40, and therefore, air or the like can be prevented from leaking into the cavity 6, and the degree of decompression can be maintained.

  Next, examples of the first embodiment and the second embodiment described above will be described with reference to FIGS. In FIG. 10, when the first seal member 4 has a circular cross section and rubber hardness Hs = 55, and the second seal member 5 has a rectangular cross section and rubber hardness Hs (Asuka C) = 25 (shown by a solid line), Change in degree of vacuum over time when the cross section is circular and the rubber hardness Hs = 55 (indicated by a one-dot chain line), and when the cross section is rectangular and the rubber hardness Hs = 71 (indicated by a two-dot chain line), that is, the leak rate Is shown. In this embodiment, the diameter of the first seal member 1 is about 120 to 200% with respect to the width or diameter of the second seal member 5 (for example, when the width or diameter of the second seal member 5 is 8.0 mm). The diameter of the sealing surface 40 of the first seal member 4 is 9.6 to 16.0 mm). The point indicated by B in FIG. 10 indicates the time when the valve of the pressure reducing means connected to the passage 7 shown in FIGS. 6 and 8 is closed in a state where the pressure in the cavity 6 is reduced.

  As apparent from FIG. 10, if the rubber hardness is harder than that of the first seal member 4 (Hs = 71) even if the cross section of the second seal member 5 is rectangular (two-dot chain line), Has already leaked when the pressure is reduced, and the inside of the cavity 6 cannot be sufficiently reduced, and when the valve is closed, the inside of the cavity 6 returns to the atmospheric pressure in a short time. If the rubber hardness is the same as that of the first seal member 4 (Hs = 55) even if the surface of the second seal member 5 is circular (one-dot chain line), Leakage is less than that indicated by the two-dot chain line, and the speed at which the cavity 6 returns to atmospheric pressure at the point B when the valve is closed is moderate. However, also in the case of the one-dot chain line, the degree of decompression of the cavity 6 is low (the value of Torr is high), and the cavity 6 returns to atmospheric pressure.

  On the other hand, when the second seal member 5 has a rectangular cross section and its rubber hardness is softer than that of the first seal member 4 (Hs (Asuka C) = 25) (in the case of the present invention indicated by a solid line). The inside of the cavity 6 is reliably decompressed by the decompression means through the passage 7 and the decompression in the cavity 6 can be maintained for a relatively long time after the point B when the valve is closed. From this, in this invention, it can be judged that the space | interval between the sealing surface 40 of the 1st sealing member 4 and the end surface of the 2nd sealing member 5 is sealed reliably.

  FIG. 11 shows a case where the first seal member 4 has a rectangular cross section and its rubber hardness Hs (Asuka C) = 35. Similarly to FIG. 10, the second seal member 5 has a rectangular cross section and a rubber hardness Hs (Asuka C) = 25 (indicated by a solid line), and a circular cross section and a rubber hardness Hs = 55 (indicated by a one-dot chain line). ), The change in the degree of vacuum with the passage of time, that is, the leak rate when the section has a rectangular cross section and the rubber hardness Hs = 71 (indicated by a two-dot chain line). Also in this embodiment, the width of the first seal member 4 with respect to the width or diameter of the second seal member 5 is about 120 to 200% (for example, the width or diameter of the second seal member 5 is 8.0 mm). In this case, the width of the first seal member 4 is 9.6 to 16.0 mm).

  As is clear from FIG. 11, if the rubber hardness is harder than that of the first seal member 4 (Hs = 71) even if the cross section of the second seal member 5 is rectangular (two-dot chain line), Compared with FIG. 10 when the pressure is reduced, the degree of pressure reduction in the cavity 6 and the speed of returning to the atmospheric pressure from the time B when the valve is closed are improved. Further, even when the second seal member 5 has a circular cross section, when the rubber hardness is harder than that of the first seal member 4 (Hs = 55) (one-dot chain line), there is a leak at the time when the inside of the cavity 6 is decompressed. Is the same as that indicated by the two-dot chain line, and the speed at which the inside of the cavity 6 returns to the atmospheric pressure at the time B when the valve is closed is slightly moderate. However, in both the case indicated by the two-dot chain line and the case indicated by the one-dot chain line, the degree of decompression in the cavity 6 is low (the numerical value of Torr is high), and the inside of the cavity 6 returns to atmospheric pressure.

  On the other hand, when the second seal member 5 has a rectangular cross section and the rubber hardness is softer than that of the first seal member 4 (Hs = 25) (in the case of the present invention indicated by the solid line), the passage 7 is interposed. Thus, the inside of the cavity 6 is reliably decompressed by the decompression means, and the decompression in the cavity 6 can be maintained for a longer time after the point B when the valve is closed. From this, in this invention, it can be judged that the space | interval between the sealing surface 40 of the 1st sealing member 4 and the end surface of the 2nd sealing member 5 is sealed reliably.

  Next, in the above-described embodiment, a change in leak rate when the hardness of the second seal member is changed will be described with reference to FIG. FIG. 12 shows a case where the first seal member 4 has a circular cross section and a hardness Hs = 55 (about 79 in terms of Asuka C). Further, FIG. 12 shows a case in which the lengths for projecting the ends 5a of the second seal member 5 from the upper surface 3a of the slide 3 are 1 mm and 2 mm, respectively. In FIG. 12, when the hardness Hs (Asuka C) = 50 or less of the second seal member 5 indicated by the horizontal axis, the leak rate increases only slightly, whereas Hs (Asuka C) = 50 is set. It has been found that if it exceeds, the leak rate increases rapidly regardless of the cross-sectional shape of the first seal member 4 and its hardness. Therefore, in the present invention, the rubber hardness of the end portion of the second seal member 5 that is in contact with at least the seal surface 40 of the first seal member 4 is set to Hs (Asuka C) with a slow leak rate (good seal performance). ) = 50 or less.

  The decompression mold of the present invention can be combined with the above-described embodiments as appropriate.

  1: lower mold (first mold), 2: upper mold (second mold), 3: slide, 4: first seal member, 5: second seal member, 5a: end of second seal member, 6: cavity, 40: seal surface of the first seal member, 50, seal surface of the second seal member, 55: contact portion, X: moving direction of the lower mold and slide, Y: lower mold and slide and upper mold Opening and closing direction,

Claims (5)

A first mold and a second mold provided to be openable and closable opposite to each other;
A slide moved in a direction different from the opening and closing direction of the first mold and the second mold;
A first seal member for sealing a mold-matching surface of the first mold and the second mold and the slide;
A second seal member that seals a mold-matching surface between the first mold and the second mold and the slide, with an end abutted against the first seal member;
The first molding die, the second molding die, and a reduced-pressure molding die that injects and fills the molding material in a state where the inside of the cavity formed by the slide is decompressed,
At least the sealing surface of the first seal member is formed into a flat shape, or the second seal member is formed into a rectangular cross section,
A reduced-pressure molding die, wherein at least an end of the second seal member that is in contact with the first seal member is made of a soft elastic body as compared with the first seal member.   2. The reduced pressure molding die according to claim 1, wherein the first seal member is formed so that a width thereof is larger than a width of the second seal member.   The end portion of the second seal member that is in contact with the first seal member has a rubber hardness Hs (Asuka C) = 50 or less, according to claim 1 or 2. Vacuum mold. A first mold and a second mold provided to be openable and closable opposite to each other;
A slide moved in a direction different from the opening and closing direction of the first mold and the second mold;
A first seal member for sealing a mold-matching surface of the first mold and the second mold and the slide;
A second seal member that seals a mold-matching surface between the first mold and the second mold and the slide, with an end abutted against the first seal member;
The first molding die, the second molding die, and a reduced-pressure molding die that injects and fills the molding material in a state where the inside of the cavity formed by the slide is decompressed,
At least the sealing surface of the first seal member is formed into a flat shape, or the second seal member is formed into a rectangular cross section,
A reduced-pressure molding die, wherein the first seal member is formed to have a width wider than that of the second seal.   The contact portion that extends in the width direction of the first seal member and contacts the first seal member is formed at an end portion of the second seal member. Vacuum mold.