JPH0732400A - Vacuum vulcanization molding machine - Google Patents

Abstract

PURPOSE:To evacuate inside of a molding chamber in a short period of time by a method wherein a cylindrical member is slidably mounted to the external surface of a pressure receiving member to form a vacuum chamber and the open end of the cylindrical member is brought into contact with a pressurizing member to form a sealed molding chamber and at the time of molding, as the pressurizing member moves, gas in the molding chamber is drawn into the vacuum chamber. CONSTITUTION:A cylindrical member 14 has an upper wall 17 extending over the upper side of an upper mold suppoter plate 12 so as to surround the plate 12 of a pressure receiving member 10 through an O-ring 13, while the member 14 slidably contacts a supporting body 11 through an O-ring 20. And the open lower end of the member 14 contacts a lower mold supporter plate 8 of a pressurizing member 6 through an O-ring 21 at the time of molding to form a sealed molding chamber 23 and a vacuum chamber 22 is formed between the plate 12 and the wall 17. A passage 24a is provided to interconnect the chamabers 22 and 23, wherein preferably a three-way switching valve 25 is provided. The chamber 23 is opened to the atmosphere for molding and the chamber 23 is connected to the chamber 22 at a desired time so that gas in the chamber 23 is drawn into the chamaber 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum vulcanizing machine for vulcanizing and molding a rubber material in a vacuum state.

[0002]

2. Description of the Related Art Conventionally, for molding rubber materials, for example,
A cavity corresponding to the shape of the product is formed inside a mold that is divided into two parts, the desired unvulcanized rubber material is set in this cavity, and a hot plate of a vulcanization molding machine called a press is set. A so-called press molding is generally used in which vulcanization is performed simultaneously with molding by using the temperature and pressure.

Various types of vulcanization molding machines used for molding rubber materials have been proposed. As one of the vulcanization molding machines, in order to deal with various inconveniences such as air, voids, pinholes, and sink marks generated by various gas components generated during rubber molding, unvulcanized in a vacuum state. A vacuum vulcanization molding machine for vulcanizing and molding a rubber material is known.

As a conventional vacuum vulcanization molding machine of this type, a closed system of a so-called pot system is adopted. In this pot-type sealing method, a desired peripheral wall that is divided into upper and lower parts is provided so as to surround the outer periphery of a mold placed on a hot plate that can be raised and lowered, and an upper peripheral wall and a lower peripheral wall are provided. While nesting, one inner peripheral surface and the other outer peripheral surface are slid through a sealing member such as an O-ring to seal the outer periphery of the mold with both peripheral walls,
It is designed to evacuate the surrounding wall.

[0005]

However, in the above-mentioned conventional pot type vacuum vulcanization molding machine, although the mold can be brought into a vacuum state by using a vacuum source such as a vacuum pump, until the vacuum state is reached. For a long time, especially when using a pot (vacuum cylinder) having versatility for thick and thin molding, a mold support plate provided with a hot plate (heat source) on which a mold is placed. As the stroke of the vacuum cylinder increases and the volume in the vacuum cylinder increases, the suction time increases from 30 seconds to 40 seconds, and the vulcanization of the rubber material progresses during the suction time. There was a problem that the function of could not be fully exerted.

Further, there is a problem that a vacuum source such as a vacuum pump and a control device for the vacuum source are required to obtain a vacuum state, the structure becomes complicated, and the economical burden increases.

The present invention has been made in view of these points, and overcomes the above-mentioned problems with the conventional ones.
It is an object of the present invention to provide a vacuum vulcanization molding machine which has a simple structure and can form a vacuum state in a short time.

[0008]

In order to achieve the above-mentioned object, the vacuum vulcanization molding machine according to the present invention as set forth in claim 1 is a pressure receiving member and a pressure member which can be brought into contact with and separated from the pressure receiving member. And a cylinder arranged so as to face each other, and the open end of which can be contacted and separated from the pressure member in an airtight manner on the outer peripheral surface of the pressure member by the contact and separation movement of the pressure member with respect to the pressure member. A member is mounted so as to be movable relative to the pressure receiving member, and a vacuum chamber having a variable volume is formed between the pressure receiving member and the tubular member by the relative movement of the tubular member with respect to the pressure receiving member, and the pressure is applied to the tubular member. In the abutting state of the members, a closed molding chamber is formed between the pressure receiving member and the pressure member, which is surrounded by the tubular member and whose volume is variable according to the distance between the pressure receiving member and the pressure member,
A conduction path is formed to connect the vacuum chamber and the closed molding chamber from the outside of the cylindrical member, and the cylindrical body is moved to the pressure receiving member by a contact movement of the pressure member with the pressure receiving member in a molding state. To increase the volume of the vacuum chamber by decreasing the volume of the hermetic molding chamber, thereby sucking the gas in the hermetic molding chamber containing the mold into the vacuum chamber, The feature is that it is in a substantially vacuum state.

According to a second aspect of the present invention, there is provided the vacuum vulcanization molding machine according to the first aspect of the present invention, in which, in the first communication path, two of the closed molding chamber, the vacuum chamber, and the atmosphere are provided. The present invention is characterized in that a switching valve for forming a flow path for selectively connecting the persons is provided.

[0010]

According to the vacuum vulcanization molding machine of the present invention as set forth in claim 1, the closed molding chamber in which the mold is housed has a substantially vacuum state with the vacuum chamber having a variable volume due to the relative movement of the tubular member with respect to the pressure receiving member. can do.

According to the vacuum vulcanization molding machine of the present invention described in claim 2, when the pressure member is close to the pressure receiving member, the gas in the hermetic molding chamber is discharged into the atmosphere and hermetically sealed immediately before the die is pressurized. By connecting the molding chamber and the vacuum chamber to each other, the amount of gas sucked into the vacuum chamber in the closed molding chamber can be reduced.

[0012]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a first view of a vacuum vulcanization molding machine according to the present invention.
It is a partially cut front view which shows the principal part of an Example.

The vacuum vulcanization molding machine 1 of this embodiment is a so-called vertical type.

As shown in FIG. 1, the vacuum vulcanization molding machine 1 of this embodiment has a desired frame 2 made of an appropriate material having rigidity. The frame 2 is arranged in parallel with the desired lower frame 3 having a substantially rectangular shape in plan view, the desired stanchions 4, 4 erected on both side portions of the lower frame 3, and directly above the lower frame 3. And a desired upper frame 5 having a substantially rectangular shape in a plane and supported on the upper portions of the columns 4.

A desired pressure member 6 is arranged on the lower frame 3. The pressing member 6 is a ram 7 arranged so as to project above the central portion of the lower frame 3.
And a lower die support plate 8 which is supported on the upper end of the ram 7 and which has a desired heat plate (heat source) not shown and which is substantially rectangular in plan view, and is shown by a desired drive source such as a hydraulic pump not shown. The ram 7 can be moved up and down by driving a desired pressure cylinder. A desired mold 9 for vulcanizing and molding an unvulcanized rubber material (not shown) is placed on the lower mold support plate 8.

At a desired position of the frame 2, various control devices such as an operation panel and a temperature control device (not shown) are provided.

A desired pressure receiving member 10 is fixedly installed on the lower portion of the upper frame 5. The pressure receiving member 10 includes a support 11 having a circular plane shape that is fixedly provided so as to project downward from the center of the upper frame 5, and a desired hot plate (heat source) that is supported by the tip of the support 11 and is not shown. The upper die support plate 12 has a substantially square plane.

That is, the lower die support plate 8 of the pressing member 6
And the upper die support plate 12 of the pressure receiving member 10 are arranged so as to face each other in parallel to each other, and can be brought into and out of contact with each other by the vertical movement of the ram 7. The die 9 placed on the lower die support plate 8 is sandwiched between the lower die support plate 8 and the upper die support plate 12 by the upward movement of the ram 9, and an appropriate pressure is applied. , Both support plates 8 and 12
Is heated by.

On the outer peripheral surface of the upper die support plate 12, O
A desired first sealing device 13 such as a ring is attached.

A tubular member 14 made of a rectangular tube is externally fitted to the pressure receiving member 10. The cylindrical member 14 extends in the up-down direction so as to surround the upper die support plate 12 and also has a lower opening 15 facing the lower die support plate 8.
And a side wall 16 having a lower end surface, and an upper wall 17 extending in the horizontal direction from the upper end of the side wall 16 along the upper surface of the upper die support plate 12 toward the peripheral edge of the support body 11. An upper opening 18 through which the support 11 is inserted is formed in the center of the member 17. Therefore, when the lower die support plate 8 is not in contact with the side wall 16 of the tubular member 14, the upper wall 17 of the tubular member 14 is seated on the upper surface of the upper die support plate 12 by the weight of the tubular member 14. It will be. The inner peripheral surface of the side wall 16 of the tubular member 14 is in sliding contact with the first sealing device 13 mounted on the outer peripheral surface of the upper die support plate 12.

The tubular member 14 is constructed such that the lower die support plate 8 is raised by the ascending movement of the ram 7 during molding and the ram 7 after molding.
By lowering the lower die support plate 8 by the lowering movement of the lower die support plate 8, the lower end surface 19 of the side wall 16 which is the outer periphery of the open end of the lower opening 15 of the tubular member 14 can be brought into contact with and separated from the lower die support member 8.
In other words, the tubular member 14 is moved upward and downward by the lower die support plate 8 of the pressure member 6 during the molding, and the upper die support plate 1 of the pressure receiving member 10 is moved.
It can be moved relative to 2. A desired second sealing device 20, such as an O-ring, is attached to the inner peripheral surface of the upper opening 18 of the tubular member 14, and the outer peripheral surface of the support 11 is slidably contacted with the second sealing device 20. ing. further,
A desired third sealing device 21 such as an O-ring is attached to a lower end surface (opposing surface) 19 of the side wall 16 of the tubular member 14 facing the lower die support plate 8, and the upper surface of the lower die support plate 8 is As the lower die support plate 8 rises, it comes into contact with the third sealing device 21.

The support 11 and the upper die support plate 12 of the pressure receiving member 10 and the side wall 16 and the upper wall 1 of the tubular member 14.
The portion surrounded by 7 is made airtight by the first sealing device 13 and the second sealing device 20 which are arranged on the surfaces of the pressure receiving member 10 and the tubular member 14 which face each other, and will be described later. A vacuum chamber 22 is formed. This vacuum chamber 22
Is caused by the ascending movement of the cylindrical member 14 with respect to the pressure receiving member 10 due to the ascent of the lower die supporting plate 8 during the molding.
The space between the upper surface of No. 2 and the lower surface of the upper wall 17 of the tubular member 14 increases so that the volume thereof increases.

The lower opening 15 of the cylindrical member 14 is attached to the lower end surface 19 of the side wall 16 facing the lower die supporting plate 8 by the raising of the lower die supporting plate 8 by the ascending movement of the ram 7 during molding. The three sealing devices 21 are brought into contact with each other so that the space around the mold 9 is isolated from the outside air at the time of molding to form a sealed molding chamber 23 described later.

That is, the vacuum chamber 22 and the hermetic molding chamber 23 are vertically separated by the first sealing device 13 mounted on the upper die supporting plate 12 during molding.

Regarding the volumes of the vacuum chamber 22 and the hermetic molding chamber 23 at the time of molding, the thicker the mold 9, the smaller the volume of the vacuum chamber 22 and the larger the hermetic molding chamber 23 become. The height of the side wall 16 of the member 14 is increased to increase the volume of the vacuum chamber 22 at the time of molding, and the closed molding chamber 23 at the time of molding.
It is desirable to make the volume larger than the above-mentioned volume so that the gas in the closed molding chamber 23 can be easily introduced into the vacuum chamber 22. Further, if the height of the side wall 16 is increased, the molds 9 of various heights are
Can correspond to.

Further, there is formed a conducting path 24 made of a suitable pipe member which connects the upper end portion and the lower end portion of the side wall 16 of the tubular member 14 from the outside, whereby the first sealing device 1 is formed.
The vacuum chamber 22 and the hermetic molding chamber 23, which are separated from each other above and below the upper die support plate 12, are connected to each other through the space 3. If necessary, an appropriate valve (not shown) may be provided in the middle of the conduction path 24.

Next, the operation of this embodiment having the above-mentioned structure will be described with reference to FIGS.

FIG. 1 shows a state before molding, and FIG. 2 is a view similar to FIG. 1 for explaining a state in which the lower mold support plate 8 is lifted to form the closed molding chamber 23, and FIG. Is the vacuum chamber 2
2 is a view similar to FIG. 1 for explaining a state in which the volume of 2 is increased, and FIG. 4 is a view similar to FIG. 1 for explaining a molding state in which the lower die support plate 8 reaches the rising end.

As shown in FIG. 1, in the state before molding, the lower die support plate 8 of the pressing member 6 is located at the bottom dead center (lowermost end), and an unvulcanized rubber (not shown) is formed in the center thereof. A mold 9 in which materials are set is placed. Then, the tubular member 14 mounted on the pressure receiving member 10 is located at the lowermost position toward the lower die supporting plate 8 due to its own weight, and the upper wall 17 of the tubular member 14 and the upper die supporting plate 12 are The surfaces facing each other are in contact with each other, and the volume of the vacuum chamber 22 that is made airtight by the first sealing device 13 and the second sealing device 20 is the smallest and almost zero.

Next, when the ram 7 is raised by operating a desired drive source such as a hydraulic pump (not shown) and driving a desired pressurizing cylinder (not shown), the lower die support plate 8 is raised at a desired speed. During the course of the start and the ascent, the parts shown in FIG. 1 are in the states shown in FIG.

That is, while the lower die support plate 8 moves toward the upper die support plate 12 of the pressure receiving member 10 due to the upward movement of the ram 7, the upper surface of the lower die support plate 8 passes through the third sealing member 21. And abutting against the lower end surface 19 of the side wall 16 of the tubular member 14 mounted on the pressure receiving member 10, a sealed molding chamber 23 for isolating the space around the mold 9 from the outside air is formed.

Next, as the ram 7 further rises, the lower die support plate 8 further rises and the pressure receiving member 10
Raise the cylindrical member 14 that is movable relative to
As a result, the parts shown in FIG. 2 are brought into the state shown in FIG.

That is, as the ram 7 further rises, the tubular member 14 ascends upward, and the upper die support plate 12 of the pressure receiving member 10 and the tubular member 14 face each other (the upper wall of the tubular member 14). The lower surface of 17 and the upper surface of the upper die support plate 12 are separated from each other to gradually increase the volume of the vacuum chamber 22, and the lower die support plate 8 and the upper die support plate 12 are also gradually increased. The surfaces facing each other are close to each other and the distance therebetween is gradually reduced, so that the volume of the hermetic molding chamber 23 is gradually reduced. And the first
Since the vacuum chamber 22 and the hermetic molding chamber 23, which are vertically separated via the hermetically sealing device 13, are communicated with each other by the conduction path 24, the gas in the hermetic molding chamber 23 is increased due to the increase in the volume of the vacuum chamber 22. As indicated by an arrow mark 3 in FIG. 3, the gas flows into the vacuum chamber 22 that is kept at a negative pressure due to airtightness, and the pressure in the sealed molding chamber 23 is gradually reduced.

Next, when the ram 7 is further raised, the lower die support plate 8 and the upper die support plate 12 are pressed against each other via the die 9, and the lower die support plate 8 reaches the rising end. The tubular member 14 that is movable relative to the pressure receiving member 10 is also located at the rising end, and the parts shown in FIG. 3 are brought into the state shown in FIG.

That is, as the ram 7 is further raised, the lower die support plate 8 and the upper die support plate 12 can be pressed against each other via the die 9 to apply a desired pressure to the die 9. Then, the tubular member 14 reaches the rising end, and the pressure receiving member 1
0 between the upper die support plate 12 and the upper wall 17 of the tubular member 14 facing each other (the upper surface of the upper die support plate 12 and the lower surface of the upper wall 17 of the tubular member 14) is the most spaced apart. Is maximized and the volume of the vacuum chamber 22 is maximized, and the surfaces of the lower die support plate 8 and the upper die support plate 12 facing each other are closest to each other and the distance therebetween is minimized, so that the volume of the hermetic molding chamber 23 is reduced. Is the smallest. As a result, a molded state is formed in which the inside of the closed molding chamber 23 is in a substantially vacuum state.
Further, the mold 9 includes a lower die support plate 8 and an upper die support plate 1
2 is supplied with heat from a heat source (not shown) provided in both of them, and the unvulcanized rubber material (not shown) in the mold 9 is pressure-molded and vulcanized.

Then, after a desired time has passed in the molding state, the ram 7 is lowered to cause the respective parts shown in FIG. 4 to perform operations reverse to the above-mentioned operations, respectively, to return to the pre-molding state shown in FIG. .

That is, as the ram 7 descends, the lower die support plate 8 and the upper die support plate 12 separate from each other, and the tubular member 14 descends downward. And the vacuum chamber 2
Reference numeral 2 denotes a surface (upper die support plate 12) which is depressurized while discharging the gas inside thereof into the hermetic molding chamber 23, and which faces the upper die support plate 12 of the pressure receiving member 10 and the upper wall 17 of the tubular member 14 to each other. 1
The upper surface of 2 and the lower surface of the upper wall 17 of the tubular member 14 contact each other to minimize the volume of the vacuum chamber 22.

Then, after the vulcanized molded product (not shown) is taken out from the mold 9, an unvulcanized rubber material (not shown) is put into the mold 9 and the above-mentioned steps are repeated. By doing so, the following molding can be performed.

Therefore, according to the present embodiment, unlike the prior art, the inside of the hermetic molding chamber 23 can be brought into a vacuum state by using the vacuum chamber 22 whose volume changes with the rise of the ram 7 without using a vacuum source. Therefore, regardless of the volume of the closed molding chamber 23, the closed molding chamber 23 can be quickly brought into a substantially vacuum state, and the original function of the vacuum vulcanization molding machine 1 can be sufficiently exhibited. It is possible to reliably prevent various problems.

Further, unlike the prior art, since a vacuum source such as a vacuum pump and a control device for the vacuum source are not required to obtain a vacuum state, the structure is simplified and the entire device can be downsized, The economic burden and the installation space can be surely reduced.

In the vacuum vulcanization molding machine 1 of the present embodiment, heat sources were provided for both the lower die support plate 8 and the upper die support plate 12, but only the lower die support plate 8 was provided if necessary. A heat source may be provided, and the shape is not particularly limited to the shape of this embodiment.

Further, the vacuum vulcanization molding machine 1 of the present embodiment is exemplified by a so-called vertical type in which the pressure member 6 and the pressure receiving member 10 are arranged in the vertical direction, but the upper frame is used. 5, a desired tubular member moving member such as a coil spring (not shown) is provided between the upper wall 17 of the tubular member 14 and the pressure member 6 and the pressure receiving member 10 in the horizontal direction. Of course, it can be applied to what is called.

Further, an appropriate valve is provided in the conduction path 24, and another conduction path communicating with the vacuum chamber 22 is formed, and the tubular member 14 is provided between the upper frame 5 and the tubular member 14.
It is also possible to use it as a vacuum pump by interposing a cylinder for independently raising and lowering the cylinder, and repeating the single raising and lowering of the tubular member 14 in correspondence with the opening and closing of the valve.

FIG. 5 shows the second embodiment of the vacuum vulcanization molding machine according to the present invention.
An example is shown.

As shown in FIG. 5, in the vacuum vulcanization molding machine 1a of the present embodiment, the hermetic molding is carried out at a desired position on the way of the passage 24 of the vacuum vulcanization molding machine 1 of the first embodiment described above. 3 as a switching valve that forms a flow path that selectively connects two of the chamber 23, the vacuum chamber 22, and A in the atmosphere with each other
A one-way switching valve 25 is provided. The other structure is the same as that of the first embodiment described above.

The operation of this embodiment will be described with reference to FIGS.

FIG. 5 is a partially cut front view showing the state before molding, and FIG. 6 shows the lower mold support plate 8 rising to show the hermetic molding chamber 2
6 is a view similar to FIG. 5 for explaining a state in which 3 is formed,
FIG. 7 is a diagram illustrating a state in which the volume of the vacuum chamber 22 has increased.
8 is a view similar to FIG. 5, and FIG. 8 is a view similar to FIG. 5 for explaining the molding state in which the lower die support plate 8 reaches the rising end.

According to this embodiment, during the upward movement of the ram 7, the three-way switching valve 25 provided in the passage 24 connects the passage 24a connected to the hermetic molding chamber 23 to the atmosphere A, and at the same time, the vacuum is generated. It is operated so as to cut off the conduction path 24b leading to the chamber 22.

Then, in the state during the upward movement of the ram 7 shown in FIG. 5 and FIG. 6, the ram 7 operates in the same manner as in the first embodiment described above, and the hermetic molding chamber 23 is formed.

Next, as the ram 7 further rises, the lower die support plate 8 further rises and the pressure receiving member 10
Raise the cylindrical member 14 that is movable relative to
As a result, the parts shown in FIG. 6 are brought into the state shown in FIG.

That is, as the ram 7 further rises, the tubular member 14 rises upward, and the surfaces of the upper die support plate 12 and the tubular member 14 of the pressure receiving member 10 facing each other (the upper wall of the tubular member 14). The lower surface of 17 and the upper surface of the upper die support plate 12 are separated from each other to gradually increase the volume of the vacuum chamber 22, and the lower die support plate 8 and the upper die support plate 12 are also gradually increased. The surfaces facing each other are close to each other and the distance therebetween is gradually reduced, so that the volume of the hermetic molding chamber 23 is gradually reduced. Then, as the volume of the hermetic molding chamber 23 decreases, the gas in the hermetic molding chamber 23 flows into the conduction path 24 as shown by the arrow in FIG. 7.
After passing through a, the three-way switching valve 25 discharges it into the atmosphere A.

Next, when the ram 7 is further raised, the lower die support plate 8 and the upper die support plate 12 are pressed against each other via the die 9, and the lower die support plate 8 reaches the rising end. The tubular member 14 that is movable relative to the pressure receiving member 10 is also located at the rising end, and the parts shown in FIG. 7 are brought into the state shown in FIG.

That is, as the ram 7 further rises, the lower die support plate 8 and the upper die support plate 12 can be pressed against each other via the die 9 to apply a desired pressure to the die 9. Then, the tubular member 14 reaches the rising end, and the pressure receiving member 1
0 between the upper die support plate 12 and the upper wall 17 of the tubular member 14 facing each other (the upper surface of the upper die support plate 12 and the lower surface of the upper wall 17 of the tubular member 14) is the most spaced apart. Is maximized and the volume of the vacuum chamber 22 is maximized, and the surfaces of the lower die support plate 8 and the upper die support plate 12 facing each other are closest to each other and the distance therebetween is minimized, so that the volume of the hermetic molding chamber 23 is reduced. Is the smallest. Then, at a desired timing such as immediately before the lower die support plate 8 and the upper die support plate 12 are pressed into contact with each other via the die 9, the three-way switching valve 2 provided in the conduction path 24 is provided.
5 is connected to the hermetic molding chamber 23 and the conductive path 24a is connected to the vacuum chamber 2
It operates so that it may connect with the conduction path 24b connected to 2.
As a result, the gas in the hermetic molding chamber 23, as shown by the arrows in FIG.
In the vacuum chamber 22 having the maximum volume after passing through, the molded state is instantly sucked and almost vacuumed. Further, the mold 9 is supplied with heat from a heat source (not shown) disposed on both the lower mold support plate 8 and the upper mold support plate 12, and the unvulcanized rubber material (not shown) in the mold 9 is supplied. Will be pressure-molded and vulcanized.

Then, after a desired time has passed in the molding state, the ram 7 is lowered and the three-way switching valve 25 provided in the conduction path 24 is connected to the vacuum chamber 22.
By connecting b to the atmosphere A and shutting off the conduction path 24a leading to the hermetic molding chamber 23,
The respective parts shown in FIG. 8 perform the operations opposite to the above-mentioned operations, and return to the state before molding shown in FIG.

That is, as the ram 7 descends, the lower die support plate 8 and the upper die support plate 12 separate from each other, and the tubular member 14 descends downward. And the vacuum chamber 2
2 discharges the gas inside thereof to the atmosphere A (strictly speaking, after temporarily sucking the atmosphere), and the upper die support plate 12 of the pressure receiving member 10 and the upper wall 17 of the tubular member 14 face each other. The surface (the upper surface of the upper die support plate 12 and the lower surface of the upper wall 17 of the tubular member 14) contact each other to minimize the volume of the vacuum chamber 22.

Then, after the vulcanized molded product (not shown) is taken out from the mold 9, an unvulcanized rubber material (not shown) is put into the mold 9 and the above-mentioned steps are repeated. By doing so, the following molding can be performed.

Therefore, according to this embodiment, the same effect as that of the above-described first embodiment is obtained, and at the same time, a part of the gas in the hermetic molding chamber 23 is discharged into the atmosphere A to maximize the volume. Since it is possible to suck the gas in the closed molding chamber 23 having a substantially minimum volume into the vacuum chamber 22, it is possible to further improve the degree of vacuum in the closed molding chamber 23,
In addition, it is possible to further shorten the time until the molding state in which the vacuum state is set is formed.

The present invention is not limited to the above embodiment, but can be modified as necessary.

[0060]

As described above, according to the vacuum vulcanization molding machine of the present invention, the closed molding chamber is quickly brought into a vacuum state by using a vacuum chamber whose volume changes as the ram rises without using a vacuum source. As a result, the original functions of the vacuum vulcanization molding machine can be fully exerted, the structure can be simplified, and the entire device can be downsized, ensuring an economical burden and installation space. It has an extremely excellent effect of reducing to.

[Brief description of drawings]

FIG. 1 is a partially cut front view showing a main part of a vacuum vulcanization molding machine according to a first embodiment of the present invention before being molded.

FIG. 2 is a view similar to FIG. 1 illustrating a state in which a lower mold support plate of a first embodiment of a vacuum vulcanization molding machine according to the present invention is lifted to form a closed molding chamber.

FIG. 3 is a view similar to FIG. 1 for explaining a state in which the volume of the vacuum chamber of the first embodiment of the vacuum vulcanization molding machine according to the present invention is increased.

FIG. 4 is a view similar to FIG. 1 for explaining a molding state in which the lower die support plate of the first embodiment of the vacuum vulcanization molding machine according to the present invention reaches the rising end.

FIG. 5 is a partially cut front view showing a main part of a vacuum vulcanization molding machine according to a second embodiment of the present invention before molding.

FIG. 6 is a view similar to FIG. 5 illustrating a state in which a lower mold support plate of a second embodiment of the vacuum vulcanization molding machine according to the present invention is lifted to form a closed molding chamber.

FIG. 7 is a view similar to FIG. 5 illustrating a state in which the volume of the vacuum chamber of the second embodiment of the vacuum vulcanization molding machine according to the present invention is increased.

FIG. 8 is a view similar to FIG. 5 for explaining a molding state in which the lower die support plate of the second embodiment of the vacuum vulcanization molding machine according to the present invention reaches the rising end.

[Explanation of symbols]

 1, 1a Vacuum vulcanization molding machine 6 Pressurizing member 7 Ram 8 Lower die support plate 9 Mold 10 Pressure receiving member 12 Upper die support plate 13 First sealing device 14 Cylindrical member 20 Second sealing device 21 Third sealing device 22 Vacuum Chamber 23 Closed Molding Chamber 24 Conducting Path 24a (Connecting to Sealing Molding Chamber) Conducting Path 24b (Connecting to Vacuum Chamber) Conducting Path 25 Three Way Switching Valve

Claims (2)

[Claims] 1. A pressure receiving member and a pressurizing member that can be brought into contact with and separated from the pressure receiving member are arranged so as to face each other,
A cylindrical member whose open end can be brought into contact with and separated from the pressure receiving member in an airtight manner by the contact and separation movement of the pressure applying member with respect to the pressure receiving member on the outer peripheral surface of the pressure receiving member. A vacuum chamber having a variable volume is formed between the pressure receiving member and the tubular member by the relative movement of the tubular member with respect to the pressure receiving member, and the pressure receiving member and the pressure member are in contact with the tubular member. A closed molding chamber surrounded by a cylindrical member and having a volume variable according to the distance between the pressure receiving member and the pressing member, and a communication path for communicating the vacuum chamber and the closed molding chamber from the outside of the cylindrical member. In the molding state, the volume of the vacuum chamber is increased and the hermetic molding is performed by moving the cylindrical body with respect to the pressure receiving member by a contact movement of the pressure member with respect to the pressure receiving member. Of the room Reducing the product, thereby vacuum vulcanization molding machine, characterized in that a substantially vacuum state closed molding chamber said sealing molding chamber of the gas inherent mold and sucked into the vacuum chamber. 2. A switching valve is provided in the communication path for forming a flow path that selectively connects two of the hermetic molding chamber, the vacuum chamber, and the atmosphere. The vacuum vulcanization molding machine according to claim 1, which is characterized in that.