JPH08155289A - Gas generator for molding cold box casting mold - Google Patents

Abstract

PURPOSE: To provide a gas generator for molding cold box casting mold capable of achieving acting effect incapable of being achieved by a conventional system. CONSTITUTION: A second heat accumulating gap part 2 having a heater 4 provided therein so as to surround a first heat accumulating gap part 1 having a heater 3 provided therein is integrated. A curing agent pressure sending route Pc having a curing agent supply port closing valve V1 and an air inlet route Pi having a curing agent jet route Ps and an air sending pressure valve V2 are respectively connected to one end part of the first heat accumulating gap part and a curing agent gas sending route Pg communicating with a gassing route Pm through a three-way changeover valve V4 is connected to the other end part of the first heat accumulating gap part 1. A sweeping air supply route Pa having a sweeping air opening and closing valve V3 is connected to one end part of the second heat accumulating gap part 2 and a sweeping hot air emitting route Ph communicating with the three-way valve V4 is connected to the other end part thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas generator for vaporizing a liquid or liquefied gas curing agent used in a cold box mold or core molding method.

[0002]

2. Description of the Related Art Conventionally, in a device for vaporizing a liquid or a liquefied gas used as a curing agent or a curing accelerator in a cold box molding method, as a vaporizing means, spraying, heating evaporation / accumulation type or bubbling is used. The method by evaporation is adopted.

Known examples of spraying methods include Japanese Patent Publication No. 50-3970, Japanese Patent Publication No. 59-6167,
Japanese Patent Publication No. 61-27092, Japanese Patent Publication No. 1-34701
Japanese Patent Publication No. 51-23370, and a known example by bubbling is disclosed in Japanese Patent Publication No. 51-23370.
JP-A-50-4455 discloses a known example of a heating evaporation / accumulation method.

[0004]

However, it is known to those skilled in the art that the above-mentioned various means also have the following defects:

1. Method by spraying (1) Dew drops tend to stagnate in the flow path, resulting in a decrease in gas concentration, and a required amount of curing agent (or curing accelerator ... hereinafter referred to as curing agent, also referred to as curing agent) Unable to send to mold / core. (2) When the hardened agent that has become dewdrops gradually accumulates in the flow path, it becomes a liquid jet during the molding of the mold (during gas ventilation), and the work environment is improved by the natural evaporation of the liquid accumulated in the flow path. It may worsen. (3) For the purpose of preventing dewdrop formation, heated air or an inert gas may be used as a mixed gas, but it is difficult to completely vaporize it in a short time.

2. Method by bubbling (1) This is a method of obtaining a mixed gas by introducing air or an inert gas into a curing agent (liquid) and bubbling it, but it is difficult to obtain a high-concentration gas.

3. Heating evaporation / accumulation type (1) It is a method to put the liquid in the accumulator tank and vaporize it by heating only the liquid part or the whole tank to accumulate the gas pressure in the tank, but at a constant temperature When vapor pressure is reached (saturated), no further vaporization takes place. (2) The amount of the curing agent required for curing the mold is 1 g or more for 1 kg of mold sand even in the molding method with the least amount of use, and the curing agent is used for a large mold of 50 to 100 kg. A large-capacity pressure storage tank is required to store pressure with a gas body. (3) A constant pressure is required to supply the gas to the mold, but if the amount of accumulated pressure is small, the tank internal pressure decreases due to gas consumption, and the supply pressure becomes insufficient. It is necessary to increase the tank capacity more and more to make up for the lack of air pressure. (4) There is also a method of pressurizing the inside of the tank with other gas such as air or an inert gas in order to make up for the lack of air pressure. However, when the tank internal pressure rises, the curing agent gas is liquefied or the mixed gas is mixed. And is diluted.

[0008]

The inventors of the present invention have succeeded in developing the present invention as a result of various studies and experiments in order to solve the above-mentioned various drawbacks of the conventional method, and the technical constitution of the present invention. Is an integral part of the second heat storage space (2) having the heater (4) and the heater (3) surrounding the first heat storage space (1). the end, the air supply air with a curing agent pumping path (Pc) and the curing agent jetting path (Ps) and the air supply pressure valve which communicates through a curing agent supply port closure valve (V ₁₎ (V ₂₎ Entrance path (P
i) are respectively connected to the other end of the first heat storage space, and a hardener gas supply path (Pg) communicating with a gassing path (Pm) via a three-way switching valve (V ₄ ) is connected to the other end. Second
Hot air for scavenging that connects a scavenging air supply path (Pa) having a scavenging opening / closing valve (V ₃ ) to one end of the heat storage void (2) and communicates with the three-way valve (V ₄ ) at the other end. In a gas generator for cold box molding, which is characterized in that a discharge path (Ph) is connected. With such a technical configuration, in the present invention, the curing agent can be completely vaporized in a short time. It is possible to diffuse and supply high concentration gas of hardener to the mold evenly, and even if residual gas exists, it does not leak and does not harm the working environment, and cures remaining in the flow path. The agent gas can be completely scavenged, and the curing agent that has not been vaporized does not remain in the flow path. Therefore, it is possible to achieve operational effects that cannot be achieved by the conventional method.

The present invention will be described in more detail based on a specific example shown in the accompanying drawings. A gas generator for cold box mold making according to the present invention includes a first heat storage void portion 1 in which a heater 3 is provided, and a second heat storage void portion 2 in which a heater 4 is provided so as to surround the first heat storage void portion 1. It is mainly composed of. In order to retain sufficient heat in the voids 1 and 2 to vaporize the hardening agent made of the liquid or liquefied gas to be injected, fins having an increased contact surface, a spherical or net-shaped heat exchange member 10 are provided. The heat exchange member 10 is disposed or filled, and is heated by the heaters 3 and 4 and stores heat.

At the upper end portion of the first heat storage void portion 1, there are provided a hardening agent pressure feeding path Pc, a hardening agent ejection path Ps, and an air feeding pressure valve V ₂ which communicate with each other via a hardening agent supply port closing valve V _1. Each of the air supply air inlet paths Pi that they have is connected.
A three-way switching valve V ₄ is provided at the lower end of the first heat storage space 1.
A hardener gas supply path Pg is connected to the gassing path Pm via the. As shown in FIG. 1, the first heat storage void portion is formed in an upright shape or an inclined shape in order to promote the gravity flow of the curing agent and prevent stagnation, and the curing agent supply portion is provided at the upper end, and the first heat storage portion is further provided. It is necessary that the structure of the void portion does not form a blind spot in the flow direction of various fluids such as liquid, gas and air, and that these fluids pass through the heat storage void portion evenly.

The scavenging opening / closing valve V is provided at the upper end of the second heat storage void 2 which is integrally provided to surround the first heat storage void 1.
Scavenging air supply path Pa having ₃ and scavenging hot air discharge path P communicating with the above-mentioned three-way valve V ₄ at the lower end.
h is provided.

In FIG. 1, reference numeral 9 shows only a gassing mechanism in a mold making machine, 7 is a mold or a core, which communicates with the three-way valve V ₄ through a gassing path Pm, and 8 is a curing agent exhaust gas. Japanese tank, exhaust gas path Pm
And communicates with the gassing mechanism.

FIG. 2 is a transverse sectional view taken along the line AA of FIG. 1, but the illustration of the heater provided therein is omitted. still,
The above specific example is an example of a gas generator in which one first heat storage void is surrounded by and integrated with a second heat storage void. However, in the case of curing a mold or a core using a plurality of types of curing agents, First
There may be a plurality of heat storage voids, and the plurality of heat storage voids may be surrounded to form the second heat storage voids integrally as described above. In that case, the connection of the various valves and the paths is in accordance with the previous example. It is obvious to those skilled in the art.

The operation mode of the gas generator of one embodiment of the present invention described above is as follows: By opening the supply port shutoff valve V ₁ , the curing agent is injected from the curing agent pressure feeding path Pc to the first heat storage void portion. 2. After a predetermined amount of the curing agent is supplied to the heat storage space, the shutoff valve V ₁ is closed to completely vaporize the curing agent in the heat storage space. 3. The three-way switching valve V ₄ is operated to connect the air supply paths Pg and Pm (Pm and Ph are blocked), and the curing agent gas in the first heat storage gap is supplied to the mold or the core 7. Since the gas pressure decreases in the process of air supply, the air supply pressurizing valve V ₂ is opened, and the hardener gas is pushed toward the mold or the core by the air or the inert gas. 4. After a lapse of a predetermined time, the air supply pressurizing valve V ₂ is closed, and at the same time, the three-way switching valve V ₄ is switched to the side where the scavenging passages Ph and Pm are in communication (Pm and Pg are blocked) and the scavenging opening / closing valve V ₃ is opened. , Even if there is some residual gas inside the first heat storage void, it is completely sealed, while pressurized air is sent from the scavenging opening / closing valve V ₃ to the second heat storage void to change it to hot air and the three-way switching valve V _It is guided to the neutralization tank through the mold or core via ₄ and the curing gas remaining in the path from the air supply path Pm to the mold or core to the neutralization tank is completely supplied. 5. The heat storage voids are heated by the heaters 3 and 4, and the temperature of these voids is maintained at a constant temperature by a temperature measuring element and a temperature controller (neither is shown).

[0015]

【The invention's effect】

1. It is possible to completely vaporize within a short time by once enclosing a predetermined amount of the curing agent in the first heat storage void portion having a high heat capacity. 2. When the curing agent gas is fed (gassing) to the mold, the vapor pressure of the curing agent itself decreases with gas consumption. By pushing, the high-concentration gas can be sent at a pressure sufficient to diffuse the gas evenly into the mold. 3. The first heat storage void is completely sealed by the shut-off valve and the switching valve except when the hardener is replenished and when the hardener gas is consumed, so even if some residual gas exists inside, it does not leak to the outside and the working environment Does not hurt 4. After consuming the gas, the switching valve closes the first heat storage void,
By supplying hot air from the second heat storage void portion toward the mold, the hardener gas remaining in the flow path from the switching valve to the neutralization tank can be completely supplied. 5. By inclining or erecting the flow path between the shutoff valve for supplying the hardening agent (liquid or liquefied gas) and the first heat storage void portion in the shortest direction and in an upright direction, the hardening agent that has not vaporized is stagnated Never.

[Brief description of drawings]

FIG. 1 shows a circuit configuration of a gas generator of the present invention, a mold or core part, and a neutralization tank part along a gas flow path.

FIG. 2 is a cross-sectional view of the gas generator of the present invention, which is a schematic view showing the positional relationship between the first heat storage void portion and the second heat storage void portion. (The heater is omitted in the figure)

[Explanation of symbols]

1 1st heat storage void part 2 2nd heat storage void part 3 heater 4 heater 5 heat storage void part partition (1st heat storage void part outer cylinder) 6 2nd heat storage void part outer cylinder 7 mold / core 8 neutralization tank 9 mold or Core gassing mechanism 10 Heat exchange member V ₁ Curing agent supply port closing valve V ₂ Air supply pressurizing valve V ₃ Scavenging opening / closing valve V ₄ Three-way switching valve Pa Scavenging air supply path Pc Curing agent pressure feeding path Pg Curing agent gas feeding Air path Ph Hot air discharge path for scavenging Pi Pi Air inlet path for air supply Pm Gassing path Ps Curing agent injection path Pn Exhaust gas path

Claims (3)

[Claims] 1. A first heat storage space is formed by surrounding a first heat storage space (1) having a heater (3) therein and integrating a second heat storage space (2) having a heater (4) therein. the one end of the section, feeding with a curing agent pumping path (Pc) and the curing agent jetting path which communicates via a curing agent supply port closure valve (V _{1) (Ps)} and the air supply pressure valve (V ₂₎ Air intake path for air (P
i) are respectively connected to the other end of the first heat storage space, and a hardener gas supply path (Pg) communicating with a gassing path (Pm) via a three-way switching valve (V ₄ ) is connected to the other end. Second
Hot air for scavenging that connects a scavenging air supply path (Pa) having a scavenging opening / closing valve (V ₃ ) to one end of the heat storage void (2) and communicates with the three-way valve (V ₄ ) at the other end. A gas generator for cold box molding, characterized in that a discharge path (Ph) is connected. 2. The cold box mold making gas according to claim 1, wherein the gas generator is arranged upright or inclined, and an inlet for a liquid or liquefied gas curing agent is provided at an upper portion of the gas generator. Generator. 3. The gas generator for cold box mold making according to claim 1, wherein a plurality of heat storage voids are provided with partition walls to be independent and integrated.