JP3172929B2 - Air energizing mechanism inside nozzle filled with molding material in mold making machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for urging air into a molding material filling nozzle of a molding machine. In the present invention, the "press-type molding material filling mechanism" is a method in which the inside of the blow head is pressurized and the molding material is blown into the molding cavity, and the "suction-type molding material filling mechanism" is a blow head using the molding cavity as a negative pressure. A method of sucking and filling the molding material inside the space.

[0002]

2. Description of the Related Art It is conventionally known to provide an air urging means at a specific location in a sand magazine (blow head) of a mold making apparatus. However, in this type of method, the internal pressure near a sand outlet is rapidly increased. Alternatively, the purpose of the present invention is to remove sand adhered to the inner wall of the sand magazine, and no air energizing means has been proposed for each filling or blowing nozzle.

Conventionally, in order to clean the sand remaining in the sand flow holes of the molding sand filling nozzle, each of the nozzles is pierced with a stick or the like, blown off with an air gun, or a large number of sticks are collectively collected by a special mechanism. Means such as crushing with air or blowing off with air are used, but the equipment is expensive or it is cumbersome to treat individually, and the solidified sand (bad sand) to be further removed is a sand magazine. It is known that there are various drawbacks such as being pushed back in. It is also known that in the conventional method, the filling of the sand cannot be performed while the sand filled inside the nozzle is being expelled, so that the filling property is not improved.

[0004] The applicant of the present invention has found that the remaining amount of the molding material on the molding surface of the molded product is equalized, mechanical pressing and shaping is facilitated, the accuracy of the molded product is improved, and a shield is provided in the path of the molding material in the nozzle. It is not necessary to provide the molding material in the molding cavity and the density and density of the molding material are improved, and in order to achieve various effects such as shortening the blowing time, the molded product is formed by using the dry powder. In forming, the suction of the powder or granules at the time of stopping the blowing is characterized in that the suction of the powder or granules near each of the blowing ports of the blow plate or at least one of the blowing nozzles attached to the blow plate is suctioned to a negative pressure. A flow-down prevention method by its own weight and a flow-down prevention device suitable for implementing this method have been proposed (1993 Patent Application No. 37244).

[0005]

Accordingly, in the conventional method, the sand that has filled and remained inside the blowing nozzle in the previous molding cycle becomes a resistance when the sand flows out from the blowing nozzle in the next molding cycle. Aims to reduce the outflow resistance in the nozzle by forcibly discharging the residual sand in the nozzle and efficiently introduce the sand in the sand magazine into the molding cavity. This is to effectively clean the inside of the blowing nozzle which could not be performed.

[0006]

The present inventors have conducted various studies and experiments to solve the above-mentioned drawbacks of the conventional system, and as a result, have found that the air energizing device for the inside of the molding material blowing nozzle of the present invention is provided. The technical configuration of the present invention is a pressurized or suction type molding material filling mechanism in a mold molding machine, in which the air vent portion of the molding material flow hole of each blow nozzle attached to the blow plate is compressed. Characterized by having an air biasing opening communicating with the air supply source,
In the air urging mechanism to the inside of the nozzle filled with the molding material, in the above configuration, facing the molding material flow hole of the blow plate, the open type blowing nozzle or the peeping nozzle, or surrounds the flow hole. And a large number of air urging openings. The peeping nozzle is a system having a blowing nozzle tip that fits into a molding material flow hole of a molding frame, and an open-type blowing nozzle is a system that does not have the above-described blowing nozzle tip.

By adopting the technical configuration as described above,
In the blow molding sand filling method, both the initial pressure and the initial speed of the sand filling process are high, and the outflow resistance in the nozzle is reduced, so that the sand filling property is improved and the rise to the intended filling pressure is achieved. It has the function of shortening the time and having the function of cleaning the opening of the air vent, so that the outflow resistance of the sand is eased and the filling property is improved even in the suction molding type molding machine, and the molding sand inside the nozzle is blown off. Thereby, the blockage of the molding sand flow hole of the nozzle can be prevented, and an action and an effect such as prevention of hardening of sand inside the nozzle can be achieved.

[0008] Specific examples of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view of an essential part in which an example of the air urging device of the present invention is applied to a peeping nozzle method. The blowing nozzle body 1 has a structure that can be fitted to a blow plate 7 by a known method. An air vent 3 connected to the compressed air path connection port P formed in the blow plate 7
A is provided. A large number of compressed air ejection holes are formed in the air vent 3A as shown in the drawing (the same applies to the air vents 3B and 3C in the following examples). The compressed air jet is not limited to the horizontal direction as shown in the figure, but is inclined with respect to the molding sand flow hole, and is tangential to the inner circumferential surface of the flow hole or a direction converging on the axis of the flow hole. In order to achieve the intended object of the present invention, the holes may be perforated and arranged in a suitable orientation. In FIG. 1, 6 is molding sand,
2 'is a nozzle tip made of a flexible material.

FIG. 2 is a longitudinal sectional view showing another example in which the present invention is applied to the peeping nozzle system. In this example, a compressed air path connection port P is provided in the nozzle body 1 and a molding is formed inside the connection port P. An air vent 3B is provided facing the sand blowing hole. Reference numeral 4 denotes a flexible packing provided on the lower surface of the nozzle body 1, and the same reference numerals as those in FIG. 1 denote the same members.

FIG. 3 is a longitudinal sectional view showing another example in which the present invention is applied to the peeping nozzle method. In this example, an air vent 3C is provided near the blowing hole of the molding sand flow prevention plate 5 provided in the blow head. It is an example of disposing
The same reference numerals as those in the above-described examples denote the same members. Although the nozzle tip 2 is shown by a broken line in FIG. 3, it is an open type blowing nozzle when it is constituted by a part shown by a solid line.

FIG. 4 is an essential part showing an example in which the present invention is applied to an open-type blowing nozzle when dry molding sand (eg, shell sand) having a sandproof plate 8 provided at the lower end of the nozzle body 1 is used. FIG. 4 is a longitudinal sectional view, and the air urging mechanism is the same as that in FIG.

[0012] The connecting compressed air to such circuitry P ₁ to P _n illustrated in FIG. 5 (urging air) is urged to the respective compressed air path connecting port P in the air biasing mechanism of the specific examples You. In FIG. 5, 9 is a sand magazine, AV-2.
Is a shut-off valve.

The apparatus for biasing air into the blowing nozzle according to the present invention can be applied to a molding material in a dry state or a wet state (for example, a molding material for a cold box). It can be used in combination with a method of suctioning the vicinity of the blow-in port to a negative pressure, such as a method of preventing powder particles from falling.
FIG. 6 illustrates a circuit system in that case. In the example shown in FIG. 6, AV-1 is a direction switching valve, SB is a negative pressure generator, F is a filter, and while the negative pressure suction prevents the molding material in the blowing nozzle from dropping naturally, the molding material is removed. When filling the molding cavity, the outflow resistance of the sand is reduced by the bias of the compressed air, and the cleaning of the blowing nozzle and the cleaning of the air vent can be performed at the same time.

In each of the circuit systems, when regulating the pressure and flow rate of air, the number of all or part of the nozzles,
Providing a pressure regulator, a flow regulating valve, and the like as necessary in these circuits is a design change means that can be appropriately performed by those skilled in the art.

[0015]

According to the present invention, when the pressurized air for urging is introduced into the nozzle at the same time as the sand is filled into the molding cavity, (1) a blow-in type sand filling method (the sand in the sand magazine is formed by the compressed air into the molding cavity. Method), the sand in the nozzle with large sand outflow resistance is blown into the molding cavity by the pressurized air for urging at the same time as the start of blowing, so both the initial pressure and initial speed of the sand filling process are high. Further, when the sand in the sand magazine is continuously blown into the molding cavity through the nozzle, the outflow resistance in the nozzle is reduced, so that the filling property of the sand can be improved.

(2) In a nozzle applying a negative pressure as in the above-mentioned patent application, it takes some time to return to the atmospheric pressure even if the negative pressure source is shut off during sand filling, and the difference from the atmospheric pressure is required. Although the pressure component contributes to the outflow resistance, the rise time to a predetermined filling pressure (for example, a blowing pressure) can be shortened by applying the air energization according to the present invention. Further, when the nozzle of the negative pressure application is used in a blowing sand filling method, the negative pressure and the blowing pressurized air combine to cause the air vent inside the nozzle to be clogged with sand. Since the biasing air passes from the back, the effect of pushing back the clogged sand and cleaning the opening of the air vent can be obtained.

(3) In the suction molding method in which the sand in the sand magazine is sucked out by applying a negative pressure to the cavity of the mold molding, the static friction resistance is large in order to cause the stationary sand to flow out into the nozzle, and the static friction resistance is large at the initial stage of filling. Although the sand outflow speed is low, the air outflow resistance is reduced by applying the air energization according to the present invention, and the filling property is improved.

(4) Regardless of the blowing type or the suction type, the molding sand inside the nozzle is easily hardened by the influence of the outside air, and the phenomenon that the sand hardly flows out or does not flow out from the nozzle when the sand is filled may occur. However, according to the mechanism of the present invention, when the sand filling into the molding cavity is started, the energizing air is intensively sent to the nozzle portion to blow off the sand inside the nozzle, thereby preventing the outflow hole from being blocked.

(5) During standby until the next molding cycle is filled with sand, the hardening of the sand inside the nozzle tends to progress due to the influence of the outside air and the like, and sometimes the sand outflow hole is closed. If the air pressurization according to the present invention is performed at the stage where the sand magazine has shifted to the standby side after the sand filling in the previous cycle, only the sand inside the nozzle is expelled and the sand filling in the next cycle is not hindered. Since the amount of sand in the sand magazine is large (has a large ventilation resistance), it is not affected by the pressurized air according to the present invention.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an essential part showing an example of the present invention.

FIG. 2 is a longitudinal sectional view showing another example of the present invention.

FIG. 3 is a longitudinal sectional view showing another example of the present invention.

FIG. 4 is a longitudinal sectional view showing still another application example of the present invention.

FIG. 5 is an example of an air energizing circuit diagram of the present invention.

FIG. 6 is a circuit diagram of an example in which a negative pressure suction mechanism is added to the air urging mechanism of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Nozzle main body 2 Nozzle tip part 2 'Nozzle tip part (flexibility) 3A air vent part 3B air vent 3C air vent 4 flexible packing 4' flexible packing 5 sandproof plate 6 molding material (sand) 7 blow plate 8 Sandproof plate 9 Sand magazine P Air path connection port P _1-n Air path connection port AV-1 Direction switching valve AV-2 Shutoff valve F Filter SB Negative pressure generator

Claims (2)

(57) [Claims] 1. A pressurized or suction type molding material filling mechanism in a mold molding machine, wherein an air bias communicating with a compressed air supply source is provided to air vent portions of molding material flow holes of individual blow nozzles mounted on a blow plate. Air opening mechanism inside the nozzle filled with molding material, characterized by having an opening for use. 2. A large number of air urging openings are provided facing or surrounding the molding material flow holes of the blow plate, the open-type blow nozzle or the peeping nozzle. A mechanism for urging air inside the nozzle filled with the molding material described.