JPS59118244A - Method and device for forming gas curing type casting mold - Google Patents

Abstract

PURPOSE:To reduce a molding cycle time by blowing curing gas through an auxiliary blow port in parallel with the operation for exchanging a blow head and a gushing head upon completion of blowing of molding sand through a main blow port. CONSTITUTION:A blow head 28 is brought into tight contact with the peripheral edge of a main blow port 26 and blowing of molding sand is accomplished. Curing gas is supplied from a gas supplying device 34 in accordance with the detection signal when the blowing of the molding sand is completed, and said gas is blown into a cavity 24. The blow head 28 with which the blowing of the molding sand is completed is retreated, and a main gushing head 30 is brought into tight contact with the peripheral edge of the port 26. A selector valve 54 is changed over in accordance with the detection signal so that an auxiliary gushing head 46 is communicated with a gas discharging device 40 and the head 30 is communicated with the device 34. The blowing of the curing gas into the cavity 24 from the head 30 through the port 26 is therefore accomplished and the molding sand in the cavity 24 is cured.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas-curing mold making method and an apparatus suitable for carrying out the method.

A type of molding method for sand molds for casting is the gas-curing mold making method, in which foundry sand is blown into the cavity of the mold from the blowing port A, and then hardening gas is blown into the blowing port to harden the molding sand inside the cavity. There is. In this molding method, the hardening of the molding sand is slow in places far from the blowing port, and this is one of the factors that determines the molding cycle time.

In view of this situation, it is an object of the present invention to provide a gas-curing mold-making method capable of shortening the molding cycle time by accelerating the hardening of molding sand at a location far from the blowing port, and a mold-making machine suitable for carrying out the method. It was made for the purpose of

A feature of the mold making method according to the present invention is that, in addition to the main inlet which also serves as an inlet for molding sand and hardening gas, there is a main inlet that communicates with the cavity at a T position as far away from the main inlet as possible. Using a mold equipped with an auxiliary inlet, after completing the blowing of molding sand from the main inlet, in parallel with the alternating operation of the blow head and gassing head, the hardening gas is injected from the auxiliary inlet into the molding sand from the main inlet. The purpose is to blow in a flow path that prevents the liquid from spilling out.

After blowing molding sand with the blow head, it takes a certain amount of time to move the flow head away from the main inlet and replace it with the gutting head, which brings the gashing head into close contact with the inlet. By curing the molding sand far from the mold to some extent, it is possible to shorten the time required to harden the entire molding sand, shortening the molding cycle time and improving the efficiency of molding work. .

The invention of the device is characterized by a mold having a molding cavity and a main air inlet communicating with the molding cavity, and a mold that can be selectively brought into close contact with the periphery of the main air inlet.
In this gas hardening type mold making machine, which includes a flow head, a gashing head, and a supply device for supplying hardening gas to the gashing head, the mold is provided with a cavity at a position as far away as possible from the main blowing port. A communicating auxiliary blow-in port is provided, and a switching valve is provided for supplying the hardening residue to the auxiliary blow-in port.

If such a device is used, not only the above-mentioned mold making method can be carried out, but also the auxiliary inlet plays the role of a vent when hardening gas is injected from the main inlet, and the auxiliary inlet is not separated from the main inlet. Since a sufficient flow of hardening gas can be obtained even at this location, the unique effect of further shortening the time required for hardening the foundry sand at this location can be obtained.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

In FIG. 1, the mold 10 is a lower mold 12. It consists of an upper mold 14 and a mandrel mold 16. The lower die 12 is fixed to a gouey base (not shown) via an exhaust manifold 18. The upper mold 14 is similarly fixed to a gouly base (not shown) via an exhaust manifold 20, and is raised and lowered together with the gouey base to open and close the mold 10. The base end of the mandrel mold 16 is fixed to the diameter 5-seat 22, and is moved in a direction perpendicular to the opening/closing direction of the mold 10 by a drive device (not shown).

A cavity 24 having the same shape as a desired mold when the mold is closed is formed in the mold 10, and a main blowing port 26 is formed in the cavity 24 to communicate with the cavity 24. A blow head 28 is provided at a position facing the main blow port 26. The blow head 28 is connected to a foundry sand supply device and a blowing air supply device (not shown), and is moved back and forth in a direction perpendicular to the opening/closing direction of the mold 10 by a drive device (not shown), so that the main blowing port 28
6 and a retracted position away from the main air inlet 26. A bushing head 80 is provided above the blow head 28, and after the blow head 28 is retracted to the retracted position, the mold 10 is moved in the opening and closing direction by a drive device (not shown). It is moved in parallel and brought to a position facing the main air inlet 26, and is further brought into close contact with the main air inlet 26 so as to surround the main air inlet 26.

The spoon head 30 is connected to a gas supply device 34 by a gas passage 32 made of a flexible tube or metal pipe. The exhaust manifolds 18 and 20 are connected to an exhaust gas system 40 by exhaust gas passages 36 and 38, and the main gas passage 8 is connected from the gas supply system 34 to the exhaust manifolds 18 and 20.
The hardening gas is blown into the cavity 24 through the 2% hardening head 80 and the main inlet 26.
After acting on the molding sand in 4, the lower mold 12 and the upper mold 14
The gas is exhausted to exhaust manifolds 18 and 20 through vents 42 and 44, respectively, and is further sucked into an exhaust gas device 40 through exhaust gas passages 36 and 38 for treatment.

An annular auxiliary gashing head 46 is fitted into the proximal end of the mandrel mold 16, and this auxiliary gashing head 46 is formed within the tie base 22 and is connected to a cogas passage 48 and a flexible tube made of metal. The wandering gas is connected to the gas device 40 via an auxiliary gas passage 50 constituted by a pipe or the like. The curing gas blown from the auxiliary gashing head 46 is in the minute gap formed between the inner peripheral surface of the opening of the lower mold 12 and upper mold 14 into which the mandrel mold 16 is inserted and the outer peripheral surface of the mandrel mold 16. The air is blown from the auxiliary air inlet 52 into the portion of the cavity 24 farthest from the main air inlet 26 .

A switching valve 54 is provided across both the main gas passage 32 and the auxiliary gas passage 50. This switching valve 5
4 is a first position where the main gassing head 30 communicates with the gas supply device 34 as shown in FIG. 1, and a first position where the auxiliary gassing head 46 communicates with the exhaust gas device 40, as shown in FIG. It can be switched to a second position where communication between the main gasssing head 30 and the gas supply device 34 is cut off, and a second position where the auxiliary gashing head 46 and the gas supply device 34 are communicated with each other. It is adapted to be switched in conjunction with the alternating operation with the gashing head 30 by an electrical interlocking means.

Next, a method of molding a mold using the mold making machine having the above configuration will be explained.

As shown in FIG. 1, with the mold 10 closed, the blow head 28 is brought into close contact with the periphery of the main blow port 26, and molding sand is blown into the mold. At this time, the switching valve 54 is at the second position shown in FIG. The situation is as follows. However, at this time, no curing gas is supplied from the gas supply device 34, and therefore no blowing is performed from the second auxiliary gassing head 46.

When the injection of molding sand is completed, this fact is detected by an appropriate detection means, and the supply of hardening gas from the gas supply device 84 is started based on the detection signal. The supplied T-curing gas is supplied through the auxiliary gas passage 50° and the auxiliary gashing head 4.
6 and the auxiliary blow-in port 52 into the cavity 24. On the other hand, when the blowing of the molding sand is completed, the Koburo head 28 is moved back to the retracted position, and the main gutting head 80 is brought into close contact with the same edge of the main blowing port 26 instead.

9- During the alternation operation between the flow head 28 and the main gassing head 30, the main air inlet 26 is open;
The number of hardening gas blowing needles from the auxiliary blowing port 52 is limited to a relatively small number.Secondly, the effect of hardening gas blowing does not appear up to the vicinity of the main blowing port 26, and molding sand is blown from the main blowing port 26. It won't spill.

When the main gassing head 80 has come into close contact with the periphery of the main air inlet 26, this fact is detected by an appropriate detection means, and the switching valve 54 is activated as shown in FIG. can be switched to the position. As a result, the auxiliary gassing head 46, which had previously been communicated with the waste supply device 34, is now communicated with the exhaust gas device 40, and on the other hand,
A main gassing head 30 is connected to a gas supply 34 . Therefore, hardening gas is blown into the cavity 24 from the main gashing head 30 through the main blowing port 26, and the molding sand in the cavity 24 is hardened. In this case, the foundry sand at a location far from the main blowing port 26 has already been hardened to some extent by the blowing of hardening gas from the auxiliary gashing head 46 or 10-, and the auxiliary gashing head 46 is in communication with the exhaust gas device 40. 1) Since the auxiliary air inlet plays the role of a vent and promotes the flow of hardening gas around it, the time required for the molding sand to harden in the entire cavity 24 is shorter than before. be done.

When the blowing of hardening gas from the main gassing head 30 is completed, this fact is detected by appropriate means, the supply of hardening gas from the gas supply device 34 is stopped, and the switching valve 54 is again turned on as shown in FIG. It is switched to the second position shown in FIG. Thereafter, the mold is opened, the mold is taken out, the inside of the cavity 24 is cleaned, and the mold 10 is closed again to complete one cycle of molding work.

In this embodiment, the blowing of the hardening gas from the auxiliary blowing port 52 is started immediately after the blowing of the molding sand is completed, and is stopped at the same time as the blowing of the hardening gas from the main blowing port 26 is started. However, it is also possible to stop the curing gas blowing from the auxiliary inlet before starting the curing gas blowing from the main inlet, or conversely, to stop the curing gas blowing from the main inlet. It is also possible to stop after a slight delay. In the latter case, curing gas is injected from both the main inlet and the auxiliary inlet in parallel for a certain period of time. This can be accomplished by independently providing switching valves in the main gas passage 32 and the auxiliary gas passage 50, and switching the stiffness independently at appropriate times.

In the above embodiment, the gas supply device 34 is designed to supply curing gas at the same pressure to the main gassing head 30 and the auxiliary gassing head 46, and the flow path area of the auxiliary blowing port 52 is By being narrowed, the blowing needle into the cavity 24 is regulated to below a certain value. The same objective can be achieved by changing the supply gas pressure from the gas supply device 34 depending on the case of supply.

In addition, it goes without saying that the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit thereof.

[Brief explanation of drawings]

FIG. 1 is a partially sectional front view showing the main parts of a mold making machine which is an embodiment of the present invention. FIG. 2 is an explanatory diagram showing another state of the switching valve in FIG. 1. 10: Mold 26: Main inlet 28 near 10
- Head 30: Main gassing head 32: Main gas passage 84: Gas supply device 40: Exhaust gas device
46: Auxiliary is the tushing head 48: Gas passage
50: Auxiliary gas passage 52: Auxiliary inlet
54: Switching valve Applicant: Toyota Motor Corporation 18- Figure 1

Claims (3)

[Claims] (1) A gas curing method in which molding sand is blown into the mold cavity from the main inlet of the mold using a blow head, and then curing gas is blown into the main inlet by a gasssing head to harden the foundry sand in the cavity. In the mold making method, after completion of blowing the molding sand from the main blowing port, in parallel with the alternating operation of the blowing head and the gutting head, at a position as far away as possible from the main blowing port), A mold making method characterized by blowing hardening gas from an auxiliary blowing port communicated with a cavity at a flow rate that does not cause molding sand to spout out from the main blowing port. (2) Molding cavity and 1 communicating with the cavity
A T-shaped blow head and a gashing head that are provided so as to be selectively in close contact with the main air inlet, and a gas supply device that supplies curing gas to the gashing head. In a gas-curing mold making machine, the mold is provided with an auxiliary blow-in port that communicates with the cavity at a position as far away as possible from the main blow-in port, and a gas supply device that supplies curing gas to the auxiliary blow-in port. A mold making machine characterized in that a switching valve for selectively communicating the auxiliary blow-in port with the gas supply device and the exhaust gas device is provided in the waste passage connecting the gas supply device and the exhaust gas device. (3) The switching valve is provided in the middle of a gas passage that guides the curing gas to the main inlet, and cuts off the supply of curing gas to the main inlet, while allowing the supply of curing gas to the auxiliary inlet. a switching valve capable of switching between a state in which the curing gas is supplied to the main inlet and a state in which the auxiliary inlet is communicated with the exhaust gas device, and a gas supply device to the main inlet; 3. The mold making machine according to claim 2, wherein said auxiliary blowing port also serves as a supply device for said auxiliary blowing port.