JP2824560B2 - Vibration device for casting sand filling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for securing a sufficient sand filling density in holes formed in horizontal two-axis directions in vanishing model casting or molding of a self-hardening mold, even if horizontal two-axis holes are formed. The present invention relates to a molding sand filling table vibrating device that can be used.

[0002]

2. Description of the Related Art The vanishing model casting method can be said to be an excellent casting method having many advantages as compared with the conventional casting method. However, in order to obtain high quality castings, the vanishing model formed by the foam molded product installed in the casting flask is not deformed, and the hollow part of the vanishing model is filled with molding sand and lost when casting the molten metal It is required that the molding sand be filled with the air permeability enough to allow the generated gas to escape sufficiently without causing the wall of the model to move.

For this reason, conventionally, a molding flask is placed and fixed on a vibration table, and the molding table is filled with the molding sand by vibrating the vibration table and the molding flask. That is, as shown in FIGS. A table 3 is horizontally and swingably arranged on a machine base 1 via springs 2 and 2, and two vibration motors 4 and 4 having a horizontal axis parallel to the Y axis are mounted on a lower surface of the table 3, By rotating the vibration motors 4 and 4 in directions opposite to each other, and vibrating the table 3 and the casting flask 5 placed and fixed on the table 3 in the Z-axis direction, the molding sand 7 is filled around the disappearing model 6. There is a vibration device configured as described above. Alternatively, FIGS. 10 and 11
As shown in FIG. 2, two vibration motors 8 having a vertical axis parallel to the Z axis are additionally fixed to both sides of the table 3 in addition to the vibration device, and the vibration motors 8 are moved in opposite directions. A vibration device or the like configured to fill the molding sand 7 around the vanishing model 6 by vibrating the table 3 and the casting flask 5 in two directions of the Z-axis direction and the X-axis direction is used. ing.

However, in the conventional vibrating apparatus, if holes are formed in the vanishing model 6 in the horizontal uniaxial direction or the horizontal biaxial direction, it is possible to secure a sufficient sand filling density in these holes. It has disadvantages that cannot be achieved. This was confirmed by the following experiment by the present inventors.
The filling experiment was performed using the experimental device shown in FIG. That is, the experimental device has a side length W of 300 m.
A test piece 9 is placed inside a casting flask 5 having a height m of 400 mm and a casting sand 7 around the test piece 9. The test piece 9 is made of a transparent acrylic resin, and has a main tube portion 9A having a uniform inner diameter (d1 = 25 mmφ) and a main tube portion 9A.
Has a uniform axis (d2 = 15 mmφ) and length (L) having an axis C2 perpendicular to the axis C1
= 90 mm), the axis C1 of the main pipe 9A is vertically oriented, and the branch pipe 9
The axis C2 of B is moved from the top surface 7A of the molding sand 7 to a predetermined depth (D
= 225 mm) and the upper end of the main pipe portion 9A protrudes from the top surface 7A of the molding sand 7. Such an experimental device is mounted and fixed on the table 3 of the first conventional example using the conventional standard type vibration device as shown in FIGS. 8 and 9, and the measurement results when the vibration time is set to 30 seconds are shown in Table 1. Shown in
Further, the same experimental apparatus was used for the first experiment as shown in FIGS.
Table 2 shows the measurement results when the vibration device in which two vibration motors 8 and 8 were additionally fixed to the conventional example was mounted and fixed on the table 3 of the second conventional example and the vibration time was fixed to 30 seconds.

[0005]

[0006]

In the conventional vibration device corresponding to Table 1, it was confirmed that there was no inflow of the molding sand 7 in the X-axis direction. This means that when the vanishing model 6 has a hole in the X-axis direction,
This indicates that it is not possible to ensure a sufficient sand filling density in this hole. Further, it is shown that even with the conventional vibration device corresponding to Table 2, it is impossible to expect the inflow amount of sand in the X-axis direction.

[0008]

The problem to be solved by the present invention is that if the vanishing model is formed with holes in the X-axis direction or in the X-axis direction and the Y-axis direction, the sand may enter into these holes. The inflow state is poor, and a sufficient filling density of molding sand cannot be ensured in the hole.

[0009]

SUMMARY OF THE INVENTION The present invention is a vibrating device for a molding sand filling table having a casting frame removably fixed on an upper surface thereof, which is swingably disposed on a machine base via a spring. And the unbalanced weights of the two vibration motors, which are mounted with parallel horizontal axes and project in the lower part or side of the table and rotate in the same direction, are simultaneously rotated. It is equipped with phase difference detection, comparison and rotation speed control equipment etc. that can adjust the position of the unbalance weight of the two vibration motors during vibration, and the X-axis direction hole is formed in the vanishing model However, the purpose of ensuring a sufficient filling density of molding sand in these holes and the purpose of ensuring a relatively uniform filling density of molding sand at each position in the casting flask have been achieved.

[0010]

According to the present invention, by rotating two vibration motors attached to the lower part or the side of the table so as to extend in the same direction in synchronism, the table can be moved vertically and horizontally in one direction (for example, X direction). Vibrates simultaneously in two directions (axial direction), and furthermore, the amplitude can be changed by changing the position of the unbalance weight of the vibration motor during the vibration. Even if a horizontal hole is formed, it is possible to secure a sufficient molding sand filling density in this hole, and also to ensure a uniform molding sand filling density at each position in the flask. You can do it.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view, and FIG. 2 is a plan view of FIG. 1, and the same or corresponding parts as those of the conventional example are denoted by the same reference numerals. 1 and 2, springs 2, 2
The table 3 is disposed horizontally and swingably via the table 3, and two vibration motors 4, 4, or 4 ', 4' having a horizontal axis parallel to the Y-axis are attached to a lower portion or a side surface of the table 3.
3 is a side view of one of the two vibration motors, FIG. 4 is a front view thereof, and FIG. 5 is a control circuit of the two vibration motors. FIG. 3 and FIG. 3 and FIG.
The phase detector 12 is mounted on the outer shafts of '4' and '4', and the unbalanced weight 13 is mounted close to the inner shaft. In FIG. 5, two (four) vibration motors 4, 4
Or, 4 'and 4' rotate at the same rotational speed by the rotation control device 14 upon receiving the instructed rotational speed command, and further convert the signal detected by the phase detector 12 in accordance with the instructed phase angle instruction into the phase difference comparator 15 The rotation of the two vibration motors 4, 4 or 4 ', 4', 4 ', 4', 4 'while maintaining a state in which the rotation speed and the phase difference are the same, is long. Thus, the casting flask 5 is filled with the casting sand 7 and the disappearing model 6 is installed inside the casting sand 7. In such a configuration, when the vibration motors 4, 4 or 4 ′, 4 ′ are rotated in the same direction, the table 3 and the flask 5 placed and fixed on the table 3 are moved vertically (Z axis) and horizontally (X axis). ) Simultaneously vibrate in two directions.

As “Comparative Experimental Example 1”, the experimental apparatus shown in FIG. 12 was mounted and fixed on the table 3 shown in FIGS.
Table 3 shows the measurement results when the vibration time was set to 30 seconds.

[0013]

In Table 3, it was confirmed that the inflow amount in the X-axis direction was significantly increased as compared with the measurement result of the first conventional example (Table 1). This proves that even if a hole in the X-axis direction is formed in the vanishing model, a sufficient filling density of the molding sand 7 can be ensured in the hole.

When the vibration table is vibrated, the following equation is generally established. That is, G = (2πf) ² r / g
Where G: acceleration, f: frequency, hertz, 1 / sec,
r: Both amplitudes, m, g: Gravitational acceleration 980 m / sec
² . In a conventional vibration device, it is easy to change the vibration frequency by changing the rotation speed of the vibration motor, but to change the amplitude, it is necessary to move the unbalance weight of the vibration motor from a fixed position, Although it was difficult to change the amplitude during vibration, it is extremely easy to change the frequency and amplitude during vibration with the vibration device of the present invention.

As “Comparative Experimental Example 2”, the experimental apparatus shown in FIG. 12 was mounted and fixed on the table 3 in FIGS.
FIGS. 6 and 7 show the measurement results when the vibration is set to 30 seconds when the acceleration is changed while the amplitude is kept constant, and when the amplitude and the acceleration are changed.

As shown in FIGS. 6 and 7, the amplitude and acceleration (=
It can be seen that the inflow of sand changes greatly depending on the square of the frequency), and in order for sand to flow into the model in the flask, the conditions of amplitude and acceleration vary depending on the shape of the model, making this selection difficult. However, in the vibration device of the present invention, the condition can be freely selected, so that the molding operation becomes extremely easy.

In the above-described embodiments, the present invention is applied to filling of molding sand in vanishing model casting.
The present invention can provide the same functions and effects as those of the above embodiment even when applied to the molding of a self-hardening mold.

[0019]

As described above, the present invention is mounted on a table with a parallel horizontal axis extending downward or to the side of a table, and simultaneously rotating two vibration motors in the same direction. Acceleration and amplitude can be freely selected and changed, so that the appropriate vibration conditions can be selected regardless of the shape of the model, and horizontal holes can be formed in the vanishing model or self-hardening mold. Is formed, it is possible to secure a sufficient filling density of the molding sand in the holes.

[Brief description of the drawings]

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

FIG. 2 is a plan view of FIG.

FIG. 3 is a side view of one vibration motor.

FIG. 4 is a front view of FIG. 3;

FIG. 5 is a control circuit diagram of two vibration motors.

FIG. 6 is a diagram showing a relationship between acceleration and sand inflow.

FIG. 7 is a diagram showing a relationship between amplitude and sand inflow.

FIG. 8 is a front view showing a first conventional example.

FIG. 9 is a plan view of FIG.

FIG. 10 is a front view showing a second conventional example.

FIG. 11 is a plan view of FIG. 10;

FIG. 12 is a perspective view of an experimental apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Machine stand 2 Spring 3 Table 4, 4 'Vibration motor 5 Casting frame 6 Lost model 7 Casting sand 8 Vibration motor 9 Test piece 12 Phase detector 13 Unbalance weight 14 Rotation speed control device 15 Phase difference comparator

Claims (1)

(57) [Claims] 1. A casting sand filling table to which a casting frame is detachably fixed on an upper surface is swingably arranged on a machine base via a spring, and extends parallel to the table by projecting to a lower portion or a side of the table. In a vibration table mounted with a horizontal axis and provided with two vibration motors each rotating in the same direction, the unbalance weights of the two vibration motors are rotated synchronously, and A molding sand filling vibrating device comprising a phase difference detection, comparison and rotation speed control device capable of adjusting the position of a motor unbalance weight during vibration.