JPH0622737B2 - Impact molding machine - Google Patents

Description

Detailed Description of the Invention I. Object of the invention (1) Field of industrial application The present invention relates to an impact molding apparatus using compressed air.

(2) Conventional technology In recent years, in a horizontal sand mold making apparatus, compressed air is blown into a mold frame instead of a jolt or squeeze type molding machine, and a sand mold is made by a shock wave of the compressed air. A molding machine was developed, the strength of the parting line position of the sand mold and the position of the mold frame surface is large, and the density is coarser as it goes to the upper surface, so outgassing at the time of pouring is good, product accuracy is also high, and The structure of the device is simple and tough, and it is being widely used because it can withstand long-term use.

As shown in FIGS. 3 and 4, the impact molding apparatus has a mold frame connection port for connecting a mold frame to the lower surface of the compressed air chamber, and the mold frame connection port projects into the pressure space air chamber. And a valve chamber that is connected to the ventilation port and is installed on the inner bottom of the compressed air chamber.The air tube is connected to the valve cylinder that projects from this valve chamber, and from the outside to the valve chamber via the valve cylinder. While ventilating compressed air, the operating valve in the valve chamber closes the vent, and at the same time, the compressed air pressure is fed from the upper end of the valve cylinder into the compressed air chamber, and after the pressure is increased to a predetermined pressure, the valve cylinder By closing the upper end with a lock cylinder and exhausting the compressed air in the valve chamber to the atmosphere, the compressed air in the compressed air chamber pushes the operating valve in the valve chamber upward to open the ventilation port. Compressed air is blown into the mold frame connected to the mold connection port, Shock wave is the propagation due to the pressure of the compressed air to the preparative and those that molding sand type.

(3) Problems to be Solved by the Invention Generally, in an impact molding apparatus, opening a working valve in a valve chamber in a short time is a point to generate a large shock wave. However, in the impact molding apparatus, since the compressed air in the valve chamber or the valve cylinder is exhausted to the atmosphere, it takes time to exhaust the compressed air and the operation of opening the operating valve in the valve chamber is slow, and Since the compressed air in the compressed air chamber is diverted from the lower surface of the valve chamber to the ventilation port, the compressed air is easily depressurized during ventilation, so that a large shock wave cannot be obtained and the precision of the sand mold made tends to be low. There were problems such as.

The present invention has been made in view of the above conventional problems, and an object thereof is to provide a vent hole communicating with a mold frame connection port in the inner bottom portion of a compressed air chamber, and to open and close the vent port mechanism. And a negative pressure exhaust mechanism for reducing the pressure of the high pressure air that has been sent into the valve chamber mechanism and holds the vent port closed when the vent port is opened. , The high-pressure air that keeps the vent closed is instantly exhausted by the negative pressure exhaust mechanism to extremely shorten the valve opening operation time, and the compressed air in the compressed air chamber flows into the vent. , A shock that can increase the precision of the sand mold made by speeding up the inflow of compressed air into the mold by directly flowing through the ventilation chamber provided in the valve chamber. To provide a molding apparatus.

II. Configuration of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention provides a compressed air chamber 12
And an air supply pipe system A for communicating compressed air into the compressed air chamber 12 and supplying compressed air into the compressed air chamber 12, and a ventilation port 20 provided in the inner bottom portion of the compressed air chamber 12 for compression. The mold frame connection port 18 communicated with the lower surface of the air chamber 12, and the compressed air chamber 12 and the mold frame connection port 18 are interposed, and the mold frame connection is connected to the compressed air chamber 12 while opening and closing the front front ventilation port 20. The compression chamber is provided with a valve chamber mechanism 22 for communicating or blocking the port 18, and a negative pressure exhaust mechanism 24 for instantaneously exhausting high pressure air in the valve chamber mechanism 22 to open the vent port 20. The mold frame 26 connected to the mold frame connection port 18 while the compressed air supplied to the air chamber 12 is supplied to the mold frame connection port 18 by the instantaneous opening of the valve chamber mechanism 22 by the negative pressure exhaust mechanism 24. Structure of impact molding machine 10 formed by molding casting sand 28 inside Is shall.

Further, the valve chamber mechanism 22 is provided at the inner bottom edge of the compressed air chamber 12, and is directly communicated with the ventilation port 20 to allow compressed air to directly flow to the ventilation port 20, and the compression chamber 32. A pressure chamber 34 provided in the center of the inner bottom of the air chamber 12 and connected to the air supply pipe system A, and also connected to the ventilation chamber 32, and the air supply pipe system A in the pressure chamber 34. The first valve chamber 40a and the second valve chamber 40a facing the ventilation port 20 side
An operating valve 38 fitted so as to define a valve chamber 40b, and the operating valve 38 is pressed downward by the high pressure air sent to the pressurizing chamber 34 by the air supply pipe system A. The ventilation port 20 is closed and held at 38, the first valve chamber 40a in the pressurization chamber 34 is exhausted and decompressed by the negative pressure exhaust mechanism 24, and the operation valve 38 is raised and opened by the compressed air pressure applied to the lower surface of the operation valve 38. It is good to let them speak.

(2) Action In the impact molding apparatus of the present invention, the vent hole communicating with the mold frame connection port is closed by the valve chamber mechanism in the compressed air chamber, and high pressure air is sent to the valve chamber mechanism and the compressed air chamber. Then, under a predetermined pressure, the negative pressure mechanism instantaneously exhausts the high pressure air in the valve chamber mechanism while opening the vent port in a short time,
The compressed air in the compressed air chamber is sent from the ventilation port into the mold frame connected to the lower surface of the mold frame connection port, and the shock waves generate the internal molding sand. Therefore, the valve opening time for the high-pressure air in the valve chamber mechanism to be instantaneously exhausted by the negative pressure exhaust mechanism is short, and the compressed air chamber is ventilated straight from the compressed air chamber to the ventilation port, so that the mold frame The shock wave propagating to the casting sand inside becomes large, and a highly accurate sand mold product is molded.

(3) Examples Hereinafter, preferred examples of the present invention will be described with reference to the accompanying drawings.

1 and 2 show an impact molding apparatus 10 according to an embodiment of the present invention.

In the figure, the impact molding apparatus 10 is a pedestal (not shown).
And the compressed air chamber 12 installed on the
A first air supply pipe 1 which is communicated with the compressed air chamber for supplying air therein
4a and.

A mold frame connection port 18 is connected to the lower surface of the bottom plate 16 in the compressed air chamber 12, and a ventilation port 20 is formed in the bottom plate 16 so as to communicate with the mold frame connection port 18. A valve chamber mechanism 22 for opening and closing the ventilation port 20 is provided at the inner bottom portion of the compressed air chamber 12.

Further, the impact molding apparatus 10 includes a second air supply pipe 14b for supplying high pressure air into the valve chamber mechanism 22 in the compressed air chamber 12 to maintain the closed state of the ventilation port 20, and the valve. The high-pressure air in the chamber mechanism 22 is instantly exhausted so that the ventilation port 2
And a negative pressure exhaust mechanism 24 for opening 0.

Then, the compressed air chamber is sent into the compressed air chamber 12 in a state where the vent hole 20 is closed by the valve chamber mechanism 22, and the high pressure air in the valve chamber mechanism 22 is supplied to the negative pressure mechanism 22 under a predetermined pressure.
The air vent 20 is opened while being instantaneously exhausted with the air, and the compressed air in the compressed air chamber 12 is discharged from the air vent 20 into the mold frame connection port 18
The air is fed into the mold frame 26 connected to the lower surface of the mold, and the internal sand 28 is formed by the attack wave.

As shown in FIG. 1, the valve chamber mechanism 22 includes a compressed air chamber 1
At the inner bottom edge of 2, a partition edge plate 3 that is erected on the peripheral wall surface
A ventilation chamber 32 which is divided into 0 and communicates with the ventilation port 20 of the bottom plate 16, and a standing member which is erected on the upper surface of the partition edge plate 30 so as to communicate with the ventilation chamber 32 at the center position of the inner bottom of the compressed air chamber 12. The pressure chamber 3 is provided.

The ventilation chamber 32 communicates with the inside of the compressed air chamber 12 through a hole 36 formed in the partition edge plate 30.

A second air supply pipe 14b for supplying high pressure air is communicated with the upper surface of the pressurizing chamber 34, and an operating valve 38 is provided inside thereof.
Are fitted. The operation valve 38 is a first valve chamber 40 that communicates the inside of the pressurizing chamber 34 with the second air supply pipe 14b shown in FIG.
a and the second valve chamber 40 facing the vent 20 side shown in FIG.
a valve plate 42 fitted so as to define b and the valve plate 4
And a valve cylinder 44 for closing the ventilation port 20 by abutting on the upper surface of the peripheral edge of the ventilation port 20 of the bottom plate 16 which is vertically provided.

A communication pipe 48 with a first stop valve 46a is connected to the first and second air supply pipes 14a and 14b, and a second stop valve 46b and a compressor 5 are provided at the outer end of the first air supply pipe 14a.
0 is communicated with. These first and second air lines 14
An air supply pipe system A is formed by including a, 14b, a communication pipe 48, a compressor 50, and the like.

In addition, the negative pressure exhaust mechanism 24 includes the second air supply pipe 14b.
It includes a vacuum tank 52 and a vacuum pump 54, which are connected to the outer end of the valve via a stop valve 46c.

Now, after setting the mold frame 26 on the upper surface of the pattern plate 58 to which the model 56 is attached and filling the inside with the sand 28, the push-up board 60 of the mold frame 26 joins the mold frame 26 to the lower surface of the mold frame connection port 18. Then, the first and second stop valves 46a and 46b are opened. Then, the high-pressure air is sent to the compressed air chamber 12, and the high-pressure air is also sent to the pressurized chamber 34 of the valve chamber mechanism 22 via the second air supply pipe 14b. At this time, the stop valve 46c of the negative pressure exhaust mechanism 24 is closed.

The high-pressure air supplied from the second air supply pipe 14b flows into the first valve chamber 40a. At this time, even if the pressure in the compressed air chamber 12 becomes equal to the pressure in the first valve chamber 40a, the pressure acting surface of the lower surface of the valve plate 42 in the second valve chamber 40b is small, so that the operating valve 38 While being pressed downward by the high-pressure air in the first valve chamber 40a, the vent hole 20 is kept closed as shown in FIG.

Therefore, when the pressure in the compressed air chamber 12 rises to, for example, about 3.5 to 4.0 kg / cm ² , the first and second stop valves 46a and 46b are closed, and at the same time, the third stop valve 46 is closed.
When c is opened, only the negative pressure exhaust force from the negative pressure exhaust mechanism 24 acts on the second air supply pipe 14b, and therefore the pressurizing chamber 3
The high pressure air in the first valve chamber 40a of No. 4 instantly becomes the vacuum tank 5
It is inflowed and exhausted into the inside of 2.

At this time, the actuating valve 38 rapidly rises to open the vent hole 20 as shown in FIG. 2, and the compressed air chamber in the compressed air chamber 12 flows directly into the vent port 20 from the bottom vent chamber 32. Then, the molding sand 28 in the mold frame 26 is compressed and molded,
Since the high pressure air in the first valve chamber 40a of the pressurizing chamber 34 is exhausted to the vacuum tank 52, the valve opening operation time of the operating valve 38 is shortened and a large shock wave is propagated to the casting sand 28, and also in the compressed air chamber 12. The compressed air is straightly ventilated from the ventilation chamber 32 to the ventilation port 20 and is not decompressed, so that a sand type product with high precision can be obtained.

After that, the third stop valve 46c is closed, the first and second stop valves 46a, 46b are opened, compressed air is sent into the pressurizing chamber 34, and the ventilation port 20 is closed by the operating valve 38. Then, the internal compressed air chamber is exhausted from the exhaust port (not shown) of the mold frame connection port 18 and then the mold frame 26 is lowered, whereby the one cycle of the molding operation is completed and the next molding operation is performed. To do.

In the embodiment, the negative pressure exhaust mechanism 34 is connected to the second air supply pipe 14b to supply high pressure air to the valve chamber mechanism 22,
It also serves as exhaust, but is not limited to this,
The negative pressure exhaust mechanism 24 may be independently connected to the valve chamber mechanism 22.

III. EFFECTS OF THE INVENTION As described above, the present invention provides the vent hole communicating with the mold frame connection port provided on the bottom surface of the compressed air chamber, and the high pressure air in the valve chamber mechanism provided at the inner bottom portion of the compressed air chamber. It is designed to supply air and close the valve, and at the time of opening operation of the vent, the negative pressure exhaust mechanism connected to the valve chamber mechanism instantaneously exhausts high pressure air to open the valve. The high-pressure air in the inside is instantly exhausted to extremely shorten the valve opening operation time, and a large shock wave due to the compressed air can be propagated to the sand in the mold.

Moreover, the inflow of compressed air into the ventilation port of the compressed air chamber is directly passed through the ventilation chamber provided in the valve chamber mechanism to speed up the inflow of compressed air into the mold frame. Without depressurizing the air, the precision of the sand mold to be molded can be dramatically improved in combination with the shortening of the valve opening time, and the molding operation does not require the trouble of opening and closing the stop valve.

[Brief description of drawings]

FIG. 1 is a sectional view of a valve chamber mechanism of an impact molding apparatus according to an embodiment of the present invention in a closed state, and FIG. 2 is a sectional view of the impact molding apparatus in which the valve chamber mechanism is in a valve opened state. 3 and 4 are cross-sectional views showing a valve closed state and a valve opened state of the valve chamber mechanism of the conventional impact molding apparatus. 10 ... Impact molding device, 12 ... Compressed air chamber, 14 ...
… Air pipe, 18 …… Mold frame connection port, 20… Vent port, 2
2 ... Valve chamber mechanism, 24 ... Negative pressure exhaust mechanism, 26 ... Mold frame, 32 ... Ventilation chamber, 34 ... Pressurization chamber, 38 ... Actuating valve, 40a, 40b ... First and second valves Chamber, 50 ... Compressor, 52 ... Vacuum pump

Claims (2)

[Claims] 1. A compressed air chamber, an air supply pipe system communicating with the compressed air chamber for supplying compressed air into the compressed air chamber, and a vent hole provided in an inner bottom portion of the compressed air chamber. And the mold frame connection port communicated with the lower surface of the compressed air chamber, the compression air chamber and the mold frame connection port are interposed, and the mold frame connection port communicates with the compressed air chamber while opening and closing the vent, or The compressed air sent to the compressed air chamber is provided with a valve chamber mechanism for shutting off, and a negative pressure exhaust mechanism for instantaneously exhausting high pressure air in the valve chamber mechanism to open the vent hole. An impact molding apparatus which molds the sand in the mold frame connected to the mold frame connection port while supplying air to the mold frame connection port by instantaneously opening the valve chamber mechanism by the negative pressure exhaust mechanism. 2. The valve chamber mechanism, which is provided at an inner bottom edge of a compressed air chamber, which directly communicates with the ventilation port and allows the compressed air to flow directly to the ventilation port, and the compressed air chamber. A pressurizing chamber that is provided at the center of the inner bottom part of the pressurization chamber and that communicates with the air supply pipe system and that communicates with the vent chamber, and a first valve chamber and the vent hole that communicate with the air supply pipe system in the pressurizing chamber. An operating valve fitted so as to define a second valve chamber facing the side, while pressing the operating valve downward by the high-pressure air sent to the pressurizing chamber by the air supply pipe system. A ventilation valve is held closed by an operating valve, the first valve chamber in the pressurizing chamber is exhausted and decompressed by the negative pressure exhaust mechanism, and the operating valve is raised and opened by compressed air pressure applied to the lower surface of the operating valve. The impact-type molding apparatus according to item 1 above.