JPH11226698A - Upper vibration pressing apparatus in vibration molding machine for green sand mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a mold of uniform hardness in a short time in one process by suspending a vibration head from an upper part of a frame through an expandable/contractible pneumatic spring by filling/exhausting compressed air to vibrate a pressurizing plate by a vibration motor built in the vibration head. SOLUTION: A pattern 9 is placed on a pattern plate 8, a molding flask 10 and an auxiliary frame 11 are placed thereon, a molding sand 12 is filled therein, and the pattern is set in a green sand mold vibration molding machine. Air is fed in a pneumatic spring 3, an elevating/lowering means 1 is driven and an elevating/lowering frame 7 is lowered. A pressurizing plate 6 of the vibration head 5 is brought into contact with the molding sand 12. Only the elevating/lowering frame 7 is lowered, and disconnected from the vibration head 5. The molding sand 12 is compressed by the self-weight of the vibration head 5 through the pressurizing plate 6. The vibration head 5 is pressed down by the pneumatic pressure of the pneumatic spring 3 at the same time. A vibration motor 4 is started, the pressurizing plate 6 is vibrated, and the molding sand 12 is compressed while being fluidized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a green molding machine for casting, and more particularly, to an upper vibration pressurizing device in a vibration molding machine for green molding.

[0002]

2. Description of the Related Art As a green molding machine for this type of casting,
Conventionally, an anvil jolt system, a ram jolt system, a blow system, a squeeze system, and an electric vibration table system are used. Anvil Jolt method is a method in which sand is poured into a casting frame on a model plate placed on the table of a molding machine, and Jolt air is sent to an air cylinder installed at the lower part of the table, causing the piston integrated with the table to float and lift the table. After lifting, the table is freely dropped by evacuating at a certain height, and the table and the air cylinder collide, and the sand in the flask is tightened toward the model below by the inertia of the sand itself. Have been.

The ram-jolt system is an advanced form of the anvil-jolt system, in which a ram is built inside a jolt piston integrated with a table, and pill air is put into the ram and the table to lift the ram and the table so that the spring effect of the pill air (in the chamber) and the ram The jolt air is controlled by opening and closing the poppet valve using the operation of the above, the ram is vibrated, and the table is hit by the ram from below to tighten the sand in the flask, and the inertia force of the sand itself The principle of sand tightening is the same as that of the anvil-jolt method.
There is also a ramjolt system using a metal spring instead of pillow air. The blow method is a method in which the space between the model plate and the pressure plate in the flask is filled with sand using an air flow, and includes a blow-in method and a reduced-pressure suction method.

In the squeeze method, sand in a casting flask is pneumatically pressed from above with an air cylinder (some of which uses a diaphragm instead), or a pressure plate slightly smaller than the inner dimension of the frame using a hydraulic cylinder. (There are a plurality of cylinders and pressure plates). In addition, a molding method is employed in which sand is poured onto the model toward a pressure plate fixed above the casting flask, and the sand or the sand is raised by a pneumatic or hydraulic squeeze cylinder together with a table above the cylinder to suppress the molding.

The electric vibration table method includes a method of molding on a vibration table in which a vibration motor is attached to a table that can be lifted by an air spring. In this method, a self-hardening mold that is molded with sand to which a resin and a hardener are added. It is often used in the production of vanishing molds that are formed only with dry sand. There is a method of putting a weight on a green mold including water and bentonite.

[0006]

As the above-mentioned conventional green molding machine, a main mechanism for clamping the mold and a die-cutting mechanism for separating the clamped frame from the model (the frame is lifted from the fixed model upwards). Stripper that pulls out the model, and a pattern draw that pulls the model down from the fixed frame).
Further, various types of molding machines, such as a framing method and a blanking method in which a frame is built in a molding machine, are used.

A molding machine having only the functions of the Jolt system and the squeeze system. Using a match plate of both upper and lower sides for a model, using a tapered blanking frame, first mold the lower mold, invert, and then 2. Description of the Related Art It has been practiced to form an upper mold and to manually remove a mold. In this case, there is an advantage that it is possible to cope with complicated molds, depending on the skill level of the operator, but there is an advantage that the upper and lower frames can be simultaneously inverted, and the mold can be removed by lifting the frame or model by hand. For example, molding has a drawback that requires labor, and accordingly, the number of skilled workers who can use this model is decreasing year by year. In addition, the frame is limited to a small one that can be held by a hand, and the jolt operation has a problem that a metal impact sound and vibration are generated due to a drop impact of the table, and the table may be broken.

[0008] The functions of the Jolt method and the squeeze method
With a stripper (or pattern draw) that has a die-cutting function, the frame is not held in the hand and is applied to medium or higher, and the use of a stripped frame is rare. Therefore, there is an advantage in that there are many semi-automatic uses in general, and there is considerable versatility for types of models. However, as the molding machine becomes larger, the jolt sound and vibration increase, and the squeezing force becomes several tens of tons, increasing the risk of damage to the parts. Therefore, it is necessary to use two molding machines or to separately provide a device for alternately switching a model between an upper mold and a lower mold, which is disadvantageous in that equipment costs are high.

However, in the case of the anvil-jolt system, the impact of the drop of the table is directly transmitted from the molding machine to the ground, but in the case of the ramjolt, the raised ram strikes the table upward. And less. In terms of mechanism, when the ramjolt is used in combination with a squeeze method described later, the jolting operation can be performed while compressing the sand in the casting flask with a squeeze.

[0010] The blow squeeze is a type having a blow mechanism that fills the space inside the frame with sand by filling it with an air flow. Generally, it is used for mass production of small articles, the molding speed is high, and there are many blanking types, and a core insert is used. Many are fully automatic except for work, and some have an automatic core holder. This method has the advantage that the molding speed is fast, but on the other hand, it has directionality to fill the sand with the air flow, and depending on the shape of the model, there is a shadow, and a poorly filled cylinder is created. Also has the problem that it cannot be modified. In addition, the model wears faster due to the sandblast effect, so the model is often made with a mold,
Model fee becomes expensive. Further, there is also a problem in that the blow-related parts are consumed a lot, the maintenance cost is expensive, and the squeeze is inevitably expensive because the hydraulic device is often used.

In the case of the electric vibration table method, in a method in which sand is put in a model and a frame on a vibrating table and shaping is performed by shaking, it is easy to manufacture a self-hardening mold, and sand is almost completely filled. The reason why there is no problem is that the resin sand itself has better fluidity and better filling property than the green sand, and the strength of the mold after curing is extremely high as compared with the strongly compressed green mold. As an application to a green mold, in order to obtain the same performance as a green molding machine with this method, increase the excitation force of the vibration motor, increase the weight in the weight-loading method, or increase the weight in the pressure method. The pressure must be increased. However, it is necessary to combine the replacement of the frame, the sanding method, the handling of the auxiliary frame, the punching device, etc.
When the vibration table has a structure in which a vibration motor is mounted below the table, it is difficult to secure a space for mounting parts other than the motor and the air spring.

As described above, the mold hardness of a conventional green molding machine is obtained by compressing sand initially filled with a jolt or a blow by a squeeze method, and is currently the mainstream of the green molding machine. Both the Jolt squeeze and the blow squeeze are formed in two steps by combining two types of apparatuses having different mechanisms, and are inevitably complicated and expensive.

In view of the problems of the prior art, the present invention makes it possible to produce a mold having a uniform hardness in a single process in a short period of time and with energy saving, and not to vibrate the main body frame. It is an object of the present invention to provide an upper vibration pressurizing device in a vibratory molding machine for a green mold capable of suppressing transmission.

[0014]

In order to achieve the above object, the upper vibration pressurizing device in the vibratory molding machine for green mold according to the present invention is constructed so as to be expandable and contractable by filling and discharging compressed air. The vibra head 5 is suspended from the upper part of the main body frame 2 via the air spring 3, the vibration motor 4 is built in the vibra head 5, and the pressing plate 6 which is vibrated by the vibra head 5 is integrally suspended, and Lifting means 1 for raising the vibra head 5 in a state where the compressed air of the air spring 3 is exhausted,
In the state where the air spring 3 is filled with the compressed air, the vibration motor 4 is started, and the molding sand 12 of the molding flask 10 is vibrated by the pressurizing plate 6 so that the molding sand 12 is tightened from above. It is.

In the present invention, the elevating means 1 has a frame-shaped elevating frame 7 configured to surround the vibra head 5 and a cord-like body 1a supported at four locations around the elevating frame 7. And an elevating mechanism 1b for winding and rewinding the cord-like body 1a. In the sand-tightened state, the elevating frame 7 is separated from the vibra head 5 and descends downward, and the elevating frame 7 It is preferable that the support state of the vibra head 5 is released.

In the present invention, the lifting means 1
Are further provided with guide rollers 2a, 2a provided on the elevating frame 7, and when the vibra head 5 is raised and lowered, the guide rollers 2a, 2a are guided by the support portions 2a, 2a of the main body frame 2 to move up and down. It is preferable to be configured to be raised and lowered together with the frame 7.

[0017]

According to the present invention, the casting sand filled in the flask is free (free-falling) vibra head,
Directly receiving three types of force: the pressing force by the weight of the pressure plate and the vibration motor, the pressing force by the expansion of the air spring, and the vibration force by the vibration motor, it is densely compressed and the flow of the molding sand by the vibration In this way, the molding sand is fastened to obtain uniform mold hardness in a short time. Of course, when the molding sand is vibrated by the vibration motor, the fluidity of the molding sand is enhanced, and the filling of the shaded portion due to the shape of the model becomes smooth.

The pressing force due to the weight of the vibra head and the pressing plate, the pressing force due to the extension of the air spring, and the vibrating force from the vibrating motor is about 2 kg / cm ² or less (in the conventional hydraulic [pneumatic] system). (Approximately 1/5 of the surface pressure), but a mold hardness of about 90 is obtained as a result.

In the present invention, the elevating means 1 has a frame-shaped elevating frame 7 configured to bend the vibra head 5 and a cord-like structure supported at four locations around the elevating frame 7. And a lifting mechanism 1b for winding and rewinding the cord-like body 1a. In the sand-tightened state, the lifting frame 7 is separated from the vibra head 5 and is lowered downward, so that the lifting frame 7 When the support state of the vibra head 5 is released, the lifting and lowering of the vibra head 5 can be performed surely, and when the vibra head 5 is raised and lowered, the vibra head 5 is kept horizontal. The press plate 6 can be moved up and down so that the press plate 6 can be accurately press-fitted into the casting frame 10, and the vibration of the vibra head 5 is transmitted to the elevating frame 7, and eventually the main body frame 2, the ground and the like when sand is tightened. Is that there is no, damage to the equipment, it is possible to avoid the discomfort to the malfunction or operator in advance.

Further, the elevating means 1 further includes guide rollers 7a, 7a provided on the elevating frame 7, and when the vibra head 5 is elevated, the guide rollers 7a, 7a Support part 2a ・ 2
When the vibra head 5 is lifted and lowered together with the lifting frame 7, the vertical movement of the lifting frame 7 can be smoothly performed while suppressing the horizontal blur of the lifting frame 7. Thus, the vertical movement can be performed while the horizontal vibration of the lifting frame 7 and the horizontal vibration of the vibra head 5 are further suppressed.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of an upper vibration pressing device in a vibrating molding machine for a green mold according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a front view of the whole vibrating molding machine for green molding according to the present invention, showing a state immediately before the start of molding.
FIG. 1 is an overall front view of a vibration molding machine for a green mold showing a state in which molding sand after the vibration pressurization is compression molded.

As shown in FIGS. 1 and 2, an auxiliary frame 11 is placed on a casting frame 10 filled with a casting sand 12 on a model 9 on a model plate 8, and this is set on a green vibration molding machine. The molding machine is provided with an elevating means 1 above a main body frame 2 which stands upright from the base frame in a front view portal type. The structure of the elevating means 1 will be described later in detail. Reference numeral 3 denotes an air spring configured to be able to expand and contract by charging and discharging compressed air.
From the upper part of the main body frame 2. Although not shown, an air source (compressor) and valve control means are connected to the air spring 3.

The vibrator head 5 has a built-in vibration motor 4 and a pressure plate 6 vibrated by the vibra head 5 is integrally suspended via a support 6a.
The elevating means 1 includes a frame-shaped elevating frame 7 configured to surround and flex the vibra head 5, and a cord-like body 1 a (here, a chain) supported at four locations around the elevating frame 7. And an elevating mechanism 1b provided with an electric motor for winding and rewinding the cord-like body 1a. Further, the elevating means 1 is provided with the elevating frame 7.
Are provided on the outer portion thereof, and when the vibra head 5 is moved up and down, the guide rollers 7a
-It is configured to be raised and lowered together with the lifting frame 7 by being guided by 2a.

The lifting frame 7 is provided with a receiving base 13 on the upper surface thereof, and is configured to engage with the lower surface of the engaging projection 5a protruding from the upper part of the vibra head 5. When the lifting mechanism 1b is further lowered after the vibra head 5 is lowered together with the lifting frame 7 and the pressing plate 6 contacts the molding sand 12 of the casting frame 10, the lifting table 1 is lifted.
3 moves away from the lower surface of the engagement projection 5a of the vibra head 5, and only the lifting frame 7 descends.

That is, in the sand-tightened state, the elevating frame 7 is separated from the vibra head 5 and descends downward to release the support state of the vibra head 5 by the elevating frame 7. The vibra head 5 is raised in a state in which the compressed air of the air spring 3 is exhausted, or the vibration motor 4 is started in a state in which the compressed air is filled in the air spring 3, and While vibrating the casting sand 12 of 10, it can be tightened from above using the air pressure of the air spring 3 and the weight of the vibra head 5.

In the vibra head 5, two electric vibration motors 4 are installed horizontally and juxtaposed.
As described above, the pressure plate 6 is attached to the vibra head 5 via the plurality of supports 6a, and the vibration of the vibration motor 4 is transmitted to the pressure plate 6.

As shown in FIG. 1, in this green vibration molding machine, the air inside the air spring 3 is exhausted in a stationary state, and the vibra head 5
Has been raised to the upper limit and stopped. Therefore, in this state, the casting flask 10 filled with the casting sand 12 is set.

As shown in FIG. 2, air is fed into the air spring 3 and the elevating means 1 is driven, and the elevating frame 7 is lowered via the cord 1a. The pressing plate 6 of the vibra head 5 comes into contact with the molding sand 12 of the casting frame 10, and the elevating means 1 is further driven from this, and only the elevating frame 7 is separated from the vibra head 5 and moved downward. And the edge of the connection between the lifting frame 7 and the vibra head 5 is cut off. Then, due to the weight of the vibra head 5, the casting flask 10 is
Simultaneously, the vibration motor 4 is started, and the pressurizing plate 6 is vibrated while the vibra head 5 is pressed down by the compressed air pressure of the air spring 3. As a result, the pressing plate 6 is compressed while vibrating the molding sand 12 of the casting frame 10 while vibrating, so that tightening with uniform hardness is performed.

[0029]

According to the present invention, the following excellent effects are achieved. Casting sand filled in the flask is free (free fall state)
Vibrator head, pressurizing plate and vibration motor, etc., receive three types of force, namely, the force of its own weight, the force of expansion of the air spring, and the force of vibration by the vibration motor. There is a remarkable effect that the molding sand can be fastened in a short time by the fluidization of the molding sand so that uniform molding hardness can be obtained. Of course, when the molding sand is vibrated by the vibration motor, the fluidity of the molding sand is enhanced, and the filling of the shaded portion due to the shape of the model becomes smooth.

There is an advantage that even if overtightening occurs due to adjustment of the mold hardness or the model shape, it can be easily controlled by adjusting the operation time of the vibration motor (for example, 5 to 15 seconds). The filled sand of the molding flask is subjected to three steps of the pressing force by the weight of the pressure plate and the extension of the air spring means and the exciting force of the vibration motor.
Approximately 2k despite small surface pressure generated by various types of force
A mold hardness of about 90 can be obtained at g / cm ² or less (conventionally, a power of about 10 kg / cm ² ± 5 kg / cm ² is required), and there is an advantage that a mold having uniform hardness can be molded in a short time. A conventional pneumatic receiver tank is not required, or a hydraulic pump unit of a hydraulic system is not required.

When a pneumatic or hydraulic cylinder is used as in the prior art, the operation requires valves, piping, an air compressor or a hydraulic pump unit, and requires a high level of maintenance and maintenance technology. In this case, it is only necessary to have a spare vibration motor, so maintenance and maintenance are very easy. Also, while the conventional molding machine always operates the air compressor and hydraulic pump motors continuously,
In the present invention, the power consumption of the main power and the vibration motor can be considered to be power consumption almost only for the time of the step of pressurizing the molding sand in a series of molding operation cycles, which is extremely energy saving and greatly increases the running cost. There is an advantage that can be reduced.

Furthermore, the structure of the lifting frame and the vibra head of the present invention as lifting means and the four-point support by a cord-like body are provided, and the edge of the lifting frame and the vibra head is cut off in the sand-tightened state, whereby the vibra head is formed. When moving up and down, it can be moved up and down while keeping it horizontal, while the press plate can be accurately press-fitted into the casting frame, and when sand is tightened, the vibration of the vibra head is lifted up and down the frame, pulling it to the body frame, ground, etc. There is an advantage that damage is not transmitted to the device, malfunction, or discomfort to the operator can be avoided beforehand. In addition, as the elevating means, the elevating frame is provided with a guide roller, and when the vibra head is raised and lowered, the guide roller is guided by the support portion of the main body frame, so that the vertical movement of the elevating frame can be suppressed while suppressing the horizontal blur. The movement can be performed smoothly, and the horizontal movement of the elevating frame, and furthermore, the horizontal movement of the vibra head can be further suppressed, whereby the horizontal movement can be performed, so that the above-mentioned effect can be further enhanced.

[Brief description of the drawings]

FIG. 1 is a front view showing a state immediately before the start of molding of an upper vibration pressing device in a vibratory molding machine for green mold according to the present invention.

FIG. 2 is a front view showing a state in which molding sand has been compression-molded after the start of molding of an upper vibration pressing device in the vibration molding machine for green mold according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Elevating means 1a Cord-like body 1b Elevating mechanism 2 Main body frame 3 Air spring 4 Vibration motor 5 Vibra head 6 Pressure plate 6a Support rod 7 Elevating frame 7a Guide roller

Claims (3)

[Claims] 1. A vibra head 5 is suspended from an upper portion of a main body frame 2 via an air spring 3 configured to be expandable and contractable by charging and discharging compressed air, and a vibration motor 4 is built in the vibra head 5. And a lifting / lowering means 1 for lifting the vibra head 5 in a state where the pressurizing plate 6 vibrated by the vibra head 5 is integrally hung and the compressed air of the air spring 3 is exhausted.
In the vibration molding machine for a green mold, the vibration motor 4 is started in a state where the compressed air is charged into the air spring 3 and the molding sand 12 of the molding frame 10 is tightened from above while vibrating the molding sand 12 by the pressing plate 6. Upper vibration pressure device. 2. The apparatus according to claim 1, wherein said elevating means comprises:
A frame-like elevating frame 7 configured to surround the
A cord 1a supported at four places around the lifting frame 7
And a lifting mechanism 1b for winding and rewinding the cord-like body 1a, and the lifting frame 7 in the sand-tightened state.
The vibrating molding machine according to claim 1, wherein the vibrating head is separated from the vibra head 5 and lowered downward to release the support state of the vibra head 5 by the elevating frame 7. Pressure device. 3. The elevating means 1 further includes guide rollers 7a provided on the elevating frame 7. When the vibra head 5 is raised and lowered, the guide rollers 7a The upper vibration pressing device in the vibratory molding machine for green mold according to claim 1 or 2, wherein the upper vibration pressing device is configured to be lifted and lowered together with the lifting frame by being guided by the portions (2a).