JP2001191149A - Vibration casting method, vibration casting machine, and core box for casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To promote the filling effect by efficiently transferring the vibration to the casting sand (green sand or self-curing sand) in a main molding flask or a core box without consuming a large energy (without any large vibration motor) to give the sufficient fluidity to the casting sand. SOLUTION: In a vibration casting method and its apparatus therefor, the casting sand is fed to the molding flask, and the casting sand is filled by giving the vibration to the casting sand. The casting sand is fluidized by directly applying the vibration to the casting sand from the top of the molding flask, and fill the casting sand while pressing the sand from the top at the same time. The core box used in this method is provided with a sand storage unit on its upper portion, and the sand storage unit has a vibrating direction regulating structure to direct the vibration and the pressure from the top downward.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for supplying molding sand to a mold,
The present invention relates to a vibration molding method for casting for performing casting by applying vibration to a casting sand, a vibration molding machine for casting and a core box for casting used in the method.

[0002]

2. Description of the Related Art Molds for castings are divided into a main mold and a core as molds, and the molding sand and the core sand used for the molding are green sand and self-hardening sand (using gas, (Including thermosetting)
Divided into In the present invention, the term casting sand is hereinafter referred to as
It is used in the meaning including green sand and self-hardening sand.

[0003] The core molding using a resin requires a high level of technology in consideration of thermal deformation in the processing of the mold. On the other hand, although the dimensional accuracy is high and the productivity is high, the production cost of the mold is high. However, it is expensive and cannot be easily modified or changed. On the other hand, for medium and large products, resin and hardener (air reaction etc.) are added to sand, kneaded and filled into a core box and molded, or a wooden mold is filled with molding sand and molded. Curing later using gas (gas-reactive curing agent)
There is something.

[0004] However, in both the main mold and the core molding (except for a part of thermosetting, etc.), when a current automatic molding machine is used, molding sand is supplied to the mold and the molding sand is supplied to the mold. Vibration is applied indirectly to impart fluidity to the molding sand, so that the molding sand is surely filled to every corner of the main mold or the core box. To apply vibration to such a sand, fix the main mold or core box on a vibration table equipped with a vibration motor,
Here, the molding sand is filled to generate vibration, and the molding sand is made to have fluidity so that the molding sand can penetrate into every corner of the formwork, thereby obtaining a dense filling.

[0005] The main vibration table system is shown in FIGS. 5 and 6 for the core and as shown in FIGS. 11 and 12 for the main mold.
Through a plurality of vibration isolating air springs 22.
5 and a plurality of vibration motors 23 (vertical vibration) are mounted on the lower surface of the vibration table
Dimensional), vertical and horizontal vibrations (vibration motor 23 ′ for three-dimensional and horizontal axis vibrations), and appropriately controlling the vibration frequency, acceleration, etc., thereby forming the mold (core box 102, main frame 103). )
Vibration was applied to the casting sand of No. 1 to obtain a filling action by smooth fluidity.

[0006]

For example, regarding the core box, the vibration table 21 vibrates the core box 102 within 1 G. Therefore, the molding sand has an inertial force due to the mass of the sand itself. Even if the lower sand in the core box 102 can be filled well only by acting as the filling force of the sand, the filling density of the upper surface is low, and the filling of the space in the lateral direction and the hole into the small side hole are performed. Difficult to fill. Further, if the vibration force is set to 1 G or more, the core box 102 floats and moves from the vibration table 21, so that a device for fixing the core box 102 to the vibration table 21 is required. Therefore, the filling of the casting sand does not always improve, and the moldability is limited.
For this reason, it is the present situation that the auxiliary work of compaction is usually performed manually.

[0007] In addition, the medium and large cores usually have a complicated shape in a three-dimensional vibration table which circulates various kinds of core boxes and vibrates up, down, left, right, front and back in order to perform a molding operation for each box. It is practically difficult to appropriately change and set various conditions such as the frequency, the excitation force, and the time to be applied in each vibration direction for the core molding for each box.

The vibration table 21 basically causes the core box 102 to vibrate.
There is a possibility that a detachable part (commonly called “place”) embedded in the casting sand may move. Most of the vibration generating power is consumed for the vibration of the vibration table 21 and the core box 102, and only a fraction of the energy is used for filling the molding sand, which is energy saving and energy saving.

Further, the ordinary vibration table 21 (vertical vibration) is provided with two vibration motors.
02 and a vibration table 21 for loading the molding sand, a large vibration motor is required.
In the case of a three-dimensional vibration table (addition of horizontal axis vibration), there may be a case where six or more vibration motors are required, and thus there is a problem that not only is the apparatus expensive but also energy loss is large.

[0010] The above-mentioned problems are caused not only by core molding but also by core molding.
The molding of the main frame using the vibration table shown in FIGS. 11 and 12 occurs almost in the same manner.

In view of the problems of the prior art, the present invention, in particular, transmits a large amount of energy to the transfer of vibration to the molding sand (green sand, self-hardening sand as defined above) in the main formwork or core box. Efficient, without consumption (no need for a large vibration motor), giving the casting sand sufficient fluidity,
It is intended to promote the filling action.

[0012]

First, a vibration molding method for casting according to the present invention, in order to achieve the above-mentioned object, supplies molding sand to a mold and applies vibration to the molding sand to perform filling. In a vibration molding method for casting, a method is employed in which the vibration is applied directly to the molding sand from above the formwork to flow the molding sand, and at the same time, is filled while being pressed from above.

In the method of the present invention, it is preferable that the form is a core box, and the vibration is applied from an opening in an upper part of the core box.

In the method of the present invention, it is preferable that the mold is a main mold, and the vibration is applied from an opening of an auxiliary frame above the main mold.

In order to achieve the above object, a vibration molding machine for casting according to the present invention supplies a molding sand to a mold and applies vibration to the molding sand for filling. An air spring means is provided at an upper portion of the main body frame, and a vibra head having a vibration motor and generating vibration is provided at a lower end of the air spring means so as to be vertically displaceable. A vibrating pressure plate for transmitting the vibration of the vibration motor and the pressing force of the air spring to the sand is provided in a hanging manner, so that the vibration pressing plate is brought into direct contact with the molding sand of the formwork to vibrate the molding sand. And pressurizing force is applied directly to perform molding.

In the present invention, preferably, the mold is a core box, and the vibration is applied from an opening at an upper portion of the core box.

Further, in the present invention, it is preferable that the mold is a main mold, and the vibration is applied from an opening of an auxiliary frame above the main mold. Further, in order to achieve the above object, the core box used in the vibration molding method for casting according to the present invention, the casting sand is supplied to the core box, and the molding sand is filled by applying vibration, A core box used in a vibration molding method for casting in which vibration is applied to the casting sand directly from above the core box to cause the casting sand to flow and simultaneously pressurize from above to perform filling, wherein the core box is In addition, a means is provided in which a sand basin is provided at the upper part thereof, and the sand basin is provided with a vibration direction regulating structure for directing vibration and pressure from above to below.

[0018]

According to the method and apparatus of the present invention,
Since the molding sand in the supplied formwork is vibrated while directly pressing it from above, the molding sand flows not only by the inertial force due to its mass but also by the vibration. The casting sand that has turned down is sinking down as appropriate,
If the angle of repose of the casting sand or, for example, the formwork is a core box,
If the shape of the recesses in the horizontal direction due to the shape slows the penetration at the shaded part, if the main formwork, even if the filling density decreases due to the penetration slowed down at the shaded part by the model set at the bottom,
At the same time, by applying pressure from above, settlement by vibration and compression by pressure act synergistically on the molding sand,
For example, it is possible to break the stone wall by the angle of repose or to perform a dense and excellent filling action by press-fitting into the shaded portion of the model.

Accordingly, since the method is a method in which the molding sand is directly vibrated, a sufficient filling effect can be expected without increasing the size of the vibration motor, and the filling can be effectively performed even at about 1 G, thereby saving energy. Only needs to be done. Of course, even when two-dimensional vibration and three-dimensional vibration are used, vibration control is easy.

According to the core box of the present invention, since the sand box is provided at the upper portion, and the sand pool is provided with the vibration direction regulating structure for directing the vibration and the pressing force from above to below,
When a vibration force and a pressing force act on the molding sand at the uppermost portion of the sand basin by the vibration pressing plate, the vibration and the pressing force applied to the molding sand at this portion are surely reduced by the vibration direction regulating structure. By virtue of the induction, the vibration and the pressing force from above can be efficiently transmitted to the molding sand, so that the molding sand can be densely filled to every corner of the core box.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a vibration molding method for casting, a vibration molding machine for casting and a core box for casting used in the method according to the present invention will be described below in detail with reference to the drawings. Embodiment 1 First, a method and an apparatus of the present invention will be described with reference to an embodiment relating to core molding using a core box. Here, for the sake of convenience of description, a description of whether or not the casting sand (this term is also used for the core as defined above) contains a self-hardening or gas-based hardener is omitted.

As shown in FIG. 1, first, casting sand is charged from a mixer 1 into a core box 2 on a conveyor 4 and supplied. The core box 2 is provided with a sand basin 3 at an upper part thereof, and the sand basin 3 is a frame that protrudes upward as a vibration direction regulating structure 3 ′ that directs vibration and pressing force from above to downward. The body is integrally provided. In FIG. 1, V1 is the amount of sand injected from the mixer, V2 and V3 are the volumes that become spaces, V4 is the amount of sand required to fill the spaces, and θ is the angle of repose. Therefore, the required amount of foundry sand is V1 + V2 + V3. However, in order to maintain the unfilled part V2 + V3 and the sand amount V4 to which approximately 15% of the compression amount for densification is added, the core box 2 is required.
Is configured such that the sand reservoir 3 has a required volume.

Then, as shown in FIG. 2, it is introduced into the main body frame 7 of the vibration molding machine via the conveyor 4. The main body frame 7 is supported on the main body bay 5 by an anti-vibration air spring 6.
Absorbs and stops the vibration of the floor from propagating to the floor.
On the upper part of the main body frame 7, a telescopic air spring means 8 is provided to hang down. At the lower end of the air spring means 8, a vibrator head 10 having a vibration motor 9 (here, two) is hung in a vertically displaceable manner, and a vibration pressure plate 11 is integrally formed at the lower end. Is provided.

Therefore, by the operation of the vibration motor 9, the vibration is transmitted to the vibration pressing plate 11, and
Due to the pressurization of air into the air spring means 8, the vibration pressure plate 11 exerts a pressing force downward. The vibration motor 9 is of a commonly used type, and can be appropriately controlled such as changing the phase of the unbalanced weight, adjusting the generated acceleration, etc., but detailed description thereof is omitted here.

FIG. 2 shows a state in which the core box 2 which has entered the molding machine is set at a predetermined position, and the air spring means 8 is at a position where the air is exhausted and the vibra head 10 is pulled up. FIG. 3 shows that the core box 2 is a conveyor 4
And the air spring means 8 extends,
The vibration pressure plate 11 is in direct contact with the molding sand located at the opening above the sand reservoir 3 of the core box 2 at a predetermined pressure. FIG. 4 shows that the vibration motor 9 is operated while the air spring means 8 is further extended, and the vibration pressing plate 11 vibrates while transmitting the vibration directly to the molding sand while vibrating. While exerting pressure, while compressing the casting sand downward through the frame-shaped vibration direction regulating structure 3 ′,
This shows a state in which filling is performed.

Embodiment 2 Next, based on FIGS. 7 to 10, a description will be given of a case where the present invention is applied to a main mold using a green mold sand or the like (also in the case of self-hardening cast sand) as a mold. In FIG. 7, similarly to the first embodiment, the mixer 1 supplies and fills the molding sand into the main formwork 24 on the conveyor (not shown). This main formwork 24
An auxiliary frame 24 'is provided at the upper part thereof as a sand reservoir for filling a required amount of molding sand by vibration and pressure.
Since the auxiliary frame 24 ′ itself has a frame shape, it also serves as the vibration direction regulating structure 3 ′ in the case of the core box 2 described above.

FIG. 8 shows the same as FIG. 2 described above.
The state where the main formwork 24 is set at a predetermined position of the molding machine is shown. FIG. 9 also shows that, as shown in FIG. 3, the air spring means 8 is extended, and the vibrating pressure plate 11 is applied to the molding sand located at the upper opening of the auxiliary frame 24 ′ of the main formwork 24 at a predetermined pressure. He is in direct contact with him. FIG. 10 shows the vibration motor 9 while the air spring means 8 is further extended.
Is activated, and the vibration pressure plate 11 vibrates while exerting a downward pressing force while directly transmitting the vibration to the molding sand while vibrating, and is transmitted through the frame-shaped vibration direction regulating structure 3 ′ of the auxiliary frame 24 ′. This shows a state in which the filling is performed while compressing the casting sand downward.

[0028]

According to the present invention, the following excellent effects are achieved. That is, in particular, it is possible to directly press the molding sand in the main formwork or the core box while vibrating, by virtue of direct contact from above through the vibration pressing plate, and without consuming a large amount of energy. Extremely fluidity and compressibility can be imparted to the casting sand,
This makes it possible to smoothly enter the shaded portion of the model of the main formwork or the lateral hole or the concave portion of the core box, thereby achieving a remarkable effect that the filling operation can be performed in a dense state.

Further, since the core box used in the method of the present invention has a sand reservoir portion provided with a vibration direction regulating structure on the upper part thereof, the vibration and the pressing force of the vibration pressing plate can be effectively directed downward. Therefore, there is an advantage that vibration and compression settling of the molding sand can be promoted, and a dense filling action can be ensured.

The other effects of the method and apparatus of the present invention and the core box are as described in detail in the above-mentioned embodiments and examples of the present invention.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view of one step of a vibration molding method for casting according to the present invention and a core box.

FIG. 2 is a vertical sectional front view of one step of a vibration molding method for casting according to the present invention, and a molding machine and a core box.

FIG. 3 is a vertical sectional front view of one step of a vibration molding method for casting according to the present invention, and a molding machine and a core box.

FIG. 4 is a longitudinal sectional front view of one step of a vibration molding method for casting according to the present invention, and a molding machine and a core box.

FIG. 5 is a vertical sectional front view of one step of a two-dimensional vibration molding method showing a conventional technique, and a molding machine and a core box.

FIG. 6 is a vertical sectional front view of one step of a three-dimensional vibration molding method showing a conventional technique, and a molding machine and a core box.

FIG. 7 is a vertical sectional front view of one step of a vibration molding method for casting according to the present invention and a main formwork.

FIG. 8 is a longitudinal sectional front view of one step of a vibration molding method for casting according to the present invention, and a molding machine and a main formwork.

FIG. 9 is a longitudinal sectional front view of one step of a vibration molding method for casting according to the present invention, and a molding machine and a main formwork.

FIG. 10 is a vertical sectional front view of one step of a vibration molding method for casting according to the present invention, and a molding machine and a main formwork.

FIG. 11 is a longitudinal sectional front view of one step of a two-dimensional vibration molding method showing a conventional technique, and a molding machine and a main formwork.

FIG. 12 is a vertical sectional front view of one step of a three-dimensional vibration molding method showing a conventional technique, and a molding machine and a main formwork.

[Explanation of symbols]

 7 body frame 8 air spring means 9 vibration motor 10 vibra head 11 vibration pressure plate

Claims (7)

[Claims] 1. A vibration molding method for casting, in which molding sand is supplied to a mold and vibration is applied to the molding to fill the molding, wherein the vibration is directly applied to the molding from above the molding. A vibration molding method for casting, in which sand is fluidized and filled while simultaneously pressing from above. 2. The vibration molding method for casting according to claim 1, wherein said mold is a core box, and said vibration is applied from an upper opening of said core box. 3. The vibration molding method for casting according to claim 1, wherein said mold is a main mold, and said vibration is applied from an opening of an auxiliary frame above said main mold. 4. A vibration molding machine for casting for supplying molding sand to a mold frame and applying vibration to the molding sand to perform filling, wherein an air spring means is provided at an upper portion of a main body frame, and a vibration motor is provided. A vibra head that generates vibration is provided at the lower end of the air spring means so as to be vertically displaceable, and the vibra head is provided with a vibration pressing plate that transmits vibration by a vibration motor and pressing force by an air spring to the molding sand. A vibration for casting, wherein the vibration pressure plate is directly in contact with the molding sand of the formwork, and vibration and pressure are applied directly to the molding sand to perform molding. Molding machine. 5. The vibration molding machine for casting according to claim 4, wherein said mold is a core box, and said vibration is applied from an opening at an upper portion of said core box. 6. The vibration molding machine for casting according to claim 4, wherein said mold is a main mold, and said vibration is applied from an opening of an auxiliary frame above said main mold. 7. A method for supplying molding sand to a mold and applying vibration to the molding sand to perform filling, wherein the vibration is directly applied to the molding sand from above the mold to cause the molding sand to flow and at the same time from above. A core box for use in a vibration molding method for casting in which filling is performed while applying pressure, wherein the core box has a sand basin at an upper part thereof, and the sand basin lowers vibration and pressure from above. A core box for casting, equipped with a vibration direction restricting structure that moves toward