JPH06277800A - Blowing type molding method and its device - Google Patents

Abstract

PURPOSE:To uniformize the hardness of the whole mold by filling up molding sand in high density condition at a long position of the interval between a pattern part and a compressive plate and in low density condition to a short position thereof and compressing the molding sand with the compressive plate. CONSTITUTION:Molding chambers (a), (b) are demarcated with a match plate 1, frame members 2, 3 and compressive plates 6, 7. By descending a blow head 10, blow nozzles 11, 12 are inserted into sand blowing holes 4, 5 in the frame members 2, 3. While detecting the pressure in the blow head 10 with a pressure sensor 16, by working an adjusting means 14, the compressed air is blown in the blow head 10 to fill the molding sand S into the molding chambers (a), (b). At the time, in the long position of the interval between the pattern part of the match plate 1 and the compressive plates 6, 7, the molding sand S is filled in the high density condition and in the short position thereof, this sand is filled in the low density condition. Successively, by working cylinders 8, 9, the molding sand S in the molding chambers (a), (b) is compressed with the compressive plates 6, 7 to make the mold. By this method, even when the shape of the pattern is complicated, the density of the mold is uniformized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blown mold making method and apparatus.

[0002]

2. Description of the Related Art Conventionally, as one of mold making methods, compressed air is supplied to a blow head to blow and fill molding sand in the blow head into a molding chamber defined by a frame member, a model plate and a compression plate. Then, there is a so-called blow-in mold molding method in which the filled molding sand is compressed to mold the mold.

[0003]

By the way, generally, when the molding sand filled in the molding chamber is compressed by the compression plate,
There is a limit to the amount of compressive force by the compression plate, and the compression plate cannot move infinitely to compress the foundry sand, so it is located at a short distance between the model plate and the compression plate. The foundry sand is largely compressed to a high density state, but the foundry sand at other places is compressed to a relatively small amount, and thus becomes a low density state. As a result, the hardness of the molded mold is
There is a problem in that it is not uniform, and it partially varies, especially when the shape of the model portion of the model plate is complicated, and this tendency is remarkable. The present invention has been made in view of the above circumstances. Even when the shape of the model portion of the model plate is complicated, the molding sand is filled with molding sand so that the hardness of the molded mold becomes uniform. It is an object of the present invention to provide a blown mold molding method and an apparatus therefor.

[0004]

In order to achieve the above object, a blown mold making method according to a first aspect of the present invention is such that compressed air is supplied to a blow head so that molding sand in the blow head is introduced into a frame member. Blow filling, then, in the blowing mold molding method of molding the mold by compressing the filled molding sand, to define the molding chamber by the frame member and the model plate and the compression plate, in the blow head, Compressed air, the pressure, the flow rate, so as to correspond to the distance between the model plate of the model plate and the compression plate in the molding chamber, the supply time is appropriately changed and supplied at least twice or more, so that, In the molding chamber, a portion where the distance between the model portion of the model plate and the compression plate is long is filled with molding sand in a high density state, and the distance between the model portion of the model plate and the compression plate is short. Foundry sand has a low density at points Was filled in, then, it is characterized by compressing the molding chamber of the molding sand close the compression plate to the pattern plate.

In the blown mold making method of the second invention, compressed air is supplied to the blow head to blow and fill the molding sand in the blow head into the frame member, and thereafter,
In a blown mold molding method in which a molding sand is molded by compressing filled molding sand, a molding chamber is defined by the frame member and a model plate having a substantially flat model surface and a compression plate, and subsequently, this molding is performed. Regarding the chamber, the pressure of the compressed air when blowing the molding sand to the lower part, so that the flow rate is lower than that when blowing the upper part, in the blow head, the compressed air, its pressure,
The method is characterized in that the flow rate and the supply time are appropriately changed to supply at least twice.

Further, in the blown mold making method in the third invention, compressed air is supplied to the blow head to blow and fill the molding sand in the blow head into the molding frame, and then the filled molding sand is compressed. In the blown mold molding method for molding a mold, a molding chamber is defined by the molding frame, the model plate and the blow head, and compressed air in the blow head, the model plate in the molding chamber. The pressure, the flow rate, and the supply time are appropriately changed so as to correspond to the distance between the model part and the blow head, and thus the distance between the model part of the model plate and the blow head is increased in the molding chamber. Is filled with molding sand in a high-density area,
Further, a portion where the distance between the model portion of the model plate and the blow head is short is filled with molding sand in a low density state, and thereafter,
It is characterized in that the blow head or the compression plate is brought close to the model plate to compress the molding sand in the molding chamber.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to FIG. A match plate 1 in a vertical state as a model plate is fixedly arranged by a conventional holding means (not shown), and two frame members 2 and 3 are moved in the left and right directions on both left and right sides of the match plate 1. These two frame members 2 and 3 have sand blowing ports 4 and 5 on the upper wall portions. Further, compression plates 6 and 7 are respectively arranged on the other end sides of the frame members 2 and 3 so as to be able to enter and leave, and the compression plates 6 and 7 are respectively moved in the left and right directions by the expansion and contraction operations of the horizontally oriented cylinders 8 and 9. It is designed to move back and forth. Also, the match plate 1
A blow head 10 is disposed above the above so as to be able to move up and down by a conventional lifting means (not shown).
Blow nozzles 11 and 12 that can be inserted into the sand blowing ports 4 and 5 when the frame members 2 and 3 match the match plate are attached to the lower surface of 0.

Further, one end of a communication pipe 13 is connected to the upper part of the blow head 10, and a plurality of adjusting means 14 capable of adjusting the pressure, flow rate, etc. of compressed air are connected to the other end of the communication pipe 13. Of the adjusting means 14 are connected in parallel in parallel with each other by arranging the exhaust ports of the compressed air source 15 in the vertical direction.
It is connected to the. A pressure sensor 16 as a pressure detecting means is mounted on the upper portion of the blow head 10. Further, the adjusting means 14 and the pressure sensor 1
6 is electrically connected to a controller 17 that controls these operations.

Next, the operation of the thus constructed apparatus will be described. As shown in FIG. 1, frame members 2 and 3 are respectively fitted to the left and right sides of the match plate 1 in a vertical state,
The cylinders 8 and 9 are extended to the required length to insert the compression plates 6 and 7 into the other ends of the frame members 2 and 3, respectively, and the molding chambers a and b.
Define. In addition, the blow head 10 is lowered so that the blow nozzles 11 and 12 are inserted into the sand blowing ports 4 and 5 of the frame members 2 and 3, respectively.
Insert. When a start command is input to the controller 17 under this condition, the plurality of adjusting means 1 are detected while the pressure in the blow head 10 is being detected by the pressure sensor 16 or by a preset program.
4, the required number of adjusting means 14 are operated, and the compressed air from the compressed air source 15 is supplied to the blow head 10 through the operated adjusting means 14 while controlling the pressure, flow rate and supply time. .

In this case, compressed air is supplied into the blow head 10 at a pressure and a flow rate corresponding to the distance between the model portion of the match plate 1 and the compression plates 6 and 7 in the molding chambers a and b. , The supply time is appropriately changed and the supply is divided into at least two or more times, so that the match plate 1 is located below each of the molding chambers a and b.
Is filled with molding sand S in a high-density state at a portion where the distance between the model portion and the compression plates 6 and 7 is long, and then the molding chamber a,
Mold sand S is filled in a low-density state at the central portion of each b where the distance between the model portion of the match plate 1 and the compression plates 6 and 7 is short, and then the molding chambers a and b.
Of the molding sand of the match plate 1 and the compression plates 6 and 7 in the upper part of each of the
Are packed in a high density state.

On the other hand, the compressed air blown together with the foundry sand S is discharged from the vent plugs (not shown) of the frame members 2 and 3. Next, the cylinders 9 and 8 are further extended to bring the compression plates 6 and 7 close to the match plate 1 to compress the molding sand S in the molding chambers a and b, respectively. After the compression of the foundry sand S, the cylinders 8 and 9 are contracted to extract the compression plates 6 and 7 from the frame members 2 and 3, respectively, and subsequently, the blow head 10 is lifted to blow nozzles 11,
12 is pulled out from the sand blowing ports 4 and 5, respectively. Then, the hardened molding sand S in the frame members 2 and 3 is extracted by a conventional means. This makes it possible to mold upper and lower molds without a frame.

In the above embodiment, when the model surface of the match plate 1 is substantially flat, the compressed air supplied into the blow head 10 is cast in the molding chambers a and b. Similar effects can be obtained even if the pressure and flow rate of sand blown into the lower part are lower than those when blown into the upper part.

Further, the molding chambers a and b in the above embodiment
Is defined by the frame members 2 and 3, the match plate 1 and the compression plates 6 and 7, but a model plate is used instead of the match plate 1 and the model plate is placed in a horizontal state.
Moreover, instead of the frame members 2 and 3, a casting frame may be used, and the model plate, the casting frame, and the lower surface of the blow head 10 may be defined. In this case, the molding sand is filled in the molding chamber as follows. That is, the inside of the blow head 10 is divided into a plurality of parts with respect to a horizontal plane, and compressed air having different pressures and flow rates can be simultaneously or sequentially supplied to each chamber, and the lower end of each chamber on the lower surface of the blow head 10 can be configured. The sand jet holes are provided on the base plate, and these sand jet holes are arranged so as to correspond to the model portion of the model plate, so that the space between the model portion of the model plate and the lower surface of the blow head 10 is long. The molding sand is blown from the located sand ejection holes by compressed air having a large pressure and flow rate to fill the molding sand in a high density state, and the distance between the model portion of the model plate and the lower surface of the blow head 10 is short. The molding sand is blown into the molding sand at a low density by blowing compressed sand having a small pressure and a small flow rate from the sand ejection holes located at the points. After that, the foundry sand in the molding chamber is compressed by the blow head 10 or the compression plate.

[0014]

As is apparent from the above description, according to the present invention, the molding sand is filled in a high density state at a portion where the distance between the model portion of the model plate and the compression plate or the blow head is long, and
Filling the molding sand in a low density state at a location where the distance between the model portion of the model board and the compression plate or the blow head is short, and then compressing the molding sand in the molding chamber with the compression plate or the blow head, Even if the shape of the model part of the model plate is complicated, the density of the molded mold is almost uniform, and the hardness of the mold is uniform overall, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

[Explanation of symbols]

 10 Blow Head 14 Adjusting Means 15 Compressed Air Source 16 Pressure Sensor 17 Controller

Claims (4)

[Claims] 1. A blown mold molding method in which compressed air is supplied to a blow head to blow and fill the molding sand in the blow head into a frame member, and then the filled molding sand is compressed to mold a mold. , A molding chamber is defined by the frame member, the model plate, and the compression plate, and compressed air is provided in the blow head so as to correspond to a distance between the model portion of the model plate and the compression plate in the molding chamber. The pressure, the flow rate, and the supply time are appropriately changed and supplied at least twice in a divided manner.Therefore, in the molding chamber, casting sand is provided at a portion where the distance between the model portion of the model plate and the compression plate is long. Is filled in a high density state, and in a portion where the distance between the model portion of the model plate and the compression plate is short, the molding sand is filled in a low density state, and then the compression plate is brought close to the model plate. Compressing foundry sand in the molding room Characteristic blow type mold making method. 2. A blown mold molding method in which compressed air is supplied to a blow head to blow and fill the molding sand in the blow head into a frame member, and then the filled molding sand is compressed to mold a mold. , A molding chamber is defined by the frame member and a model plate having a substantially flat model surface and a compression plate, and subsequently,
Regarding this molding chamber, the pressure, flow rate, and supply time of the compressed air in the blow head are set so that the pressure and flow rate of the compressed air when blowing the molding sand to the lower side are lower than those when blowing the molding sand to the upper side. A blown mold making method, which comprises appropriately changing and supplying at least twice or more. 3. A blown mold molding method in which compressed air is supplied to a blow head to blow and fill the molding sand in the blow head into a molding frame, and then the filled molding sand is compressed to mold a mold. , A molding chamber is defined by the casting frame, the model plate, and the blow head, and compressed air in the blow head corresponds to a distance between the model portion of the model plate and the blow head in the molding chamber. The pressure, the flow rate, and the supply time are changed as appropriate to supply,
In the molding chamber, a portion where the distance between the model portion of the model plate and the blow head is long is filled with molding sand in a high density state, and the distance between the model portion of the model plate and the blow head is short. A blow-in mold molding method, characterized in that molding sand is filled in a low-density state at a location, and then the blow head or compression plate is brought close to the model plate to compress the molding sand in the molding chamber. 4. A blow type in which compressed air is supplied to the blow head to blow and fill the molding sand in the blow head into a frame member or a molding frame, and thereafter, the filled molding sand is compressed to form a mold. In the mold making apparatus, the blow head 10
The blow head 10 has its discharge ports communicated with each other and a plurality of discharge ports are provided so that the blow head 10 communicates with the blow head 10 in parallel. The adjusting means 14 for adjusting the pressure and flow rate of the compressed air, and these adjusting means. A compressed air source 15 communicating with the air supply port of the means 14, a pressure detecting means 16 for detecting the pressure in the blow head 10, and an electrically connected to the adjusting means 14 and the pressure detecting means 16 A blower mold making apparatus, comprising: a controller 17 for controlling the operations of the adjusting means 14 and the pressure detecting means 16.