JP3126711B1 - Mold molding method and apparatus - Google Patents

Abstract

Abstract: [PROBLEMS] To shorten the time for applying vibration when filling molding sand under a horizontal hole or chin. SOLUTION: A molding method for placing a casting model in a casting frame on a table board and accommodating casting sand, and applying a substantially circular vibration along a predetermined vertical plane to the table board to fill the casting sand. In the above, the model is in a form having a horizontal solid or hollow extension in the installation state in the flask, and the model is installed in the flask so that the extension direction of the extension is in a direction along a predetermined vertical plane. Then, the table board is inclined at a small angle with respect to the horizontal in a predetermined vertical plane to give vibration. 1 ° tilt angle
５5 °. The apparatus includes a vibration table 2, an unbalanced weight vibrating device 3 in which respective rotationally unbalanced weights on two parallel axes rotate, and a rotation in the same direction at the same speed while maintaining a predetermined initial phase difference of the unbalanced weight. Synchronous rotating means for
Table board angle changing means for tilting the table board 10 at a small predetermined angle in a vertical plane perpendicular to two parallel axes is provided.
The air spring 12 is used as angle changing means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a mold for use in a vanishing model casting method using dry sand without a binder as a molding sand, and a self-hardening mold for using a binder as a molding sand. It relates to a molding method.

[0002]

2. Description of the Related Art Molding of a mold used in a vanishing model casting method,
An important point in molding a self-hardening mold is to fill sand around a foam model or a wooden model with a sufficient density. If it is not filled with a sufficient density, casting defects such as bumps and seizures occur on the casting, and a good casting cannot be obtained. Conventionally, a vertical one-axis vibrator or an orthogonal X, Y, Z-axis three-axis vibrator has been used at the time of molding. However, a horizontal hole of the model and a lower side of the horizontal protrusion are used. There was a problem that molding sand could not be sufficiently filled in the jaw. In response to this problem, recently, a two-axis vibrator and a three-axis vibrator that generate circular motion vibration, that is, circular vibration, have been developed, and it has become possible to fill a casting hole into a horizontal hole or a lower part of a jaw. .

[0003]

However, it has been found that even in the two-axis vibrator and the three-axis vibrator for generating the circular vibration, the filling density of the molding sand may not be sufficient. In other words, in order to sufficiently fill the casting hole with the horizontal hole or the lower part of the jaw in a state where the casting model is installed in the casting flask, there is a problem that the time for giving the circular vibration is considerably long. The present invention aims to reduce the time for vibrating to adequately fill the foundry sand in the horizontal direction of the hole and chin lower side.

[0004]

According to the method of the present invention, a casting model is placed in a casting frame fixed on a table board, casting sand is accommodated, and a circular or elliptical substantially circular shape along a predetermined vertical plane is provided. In the molding method of filling a mold sand by giving the vibration of the table to the table board, the casting model is a form having a solid or hollow extension portion extending horizontally in the installed state in the casting frame, this The casting model is installed in the casting frame such that the extension direction of the extension portion is in a direction along the predetermined vertical plane, and the table board is horizontally positioned within the predetermined vertical plane and smaller than the angle of repose of the molding sand. It is to provide the vibration in a state of being inclined to a sufficiently small angle, the tape
The angle at which the bull board is tilted is in the range of 1 ° to 5 °.

[0005] In this method, even if a substantially circular vibration is applied in the same manner as in the prior art, a substantially circular vibration is applied in a state of being tilted to an angle sufficiently smaller than the angle of repose of the foundry sand, so that the sand is not tilted. In comparison with the case, the filling time of the molding sand into the horizontally extending jaw portion or the hollow portion can be greatly reduced. Accordingly, it is possible to shorten the time required for molding a good mold in which the molding sand is reliably filled under the chin portion or in the hollow portion.

[0006] The angles of tilting the table panel 1 ° ~
The range of 5 ° is inconvenient due to the inclination.
This is because almost no occurrence occurs. That is, when the state hardened by inclining the drag flask per by vibrating the casting sand, because the upper surface of the sand is substantially horizontally inclined casting frame,
The upper surface of the sand is inclined when the flask is returned to the horizontal position. Obedience
I, time-consuming inconvenience arising in this angle of inclination to replenish the sand larger the leveling work. Further, there is a disadvantage that in the case of molding using a foamed model inclination angle movement or deformation of sand is filled unevenly models are arising larger. Angles 1 ° to 5 ° are small, so eliminate these inconveniences
Can be.

[0007] The apparatus of the present invention comprises a spring-supported vibrating table for filling molding sand, which is capable of fixing a casting flask on a table board, and a rotating shaft provided on a lower portion of the table board on two parallel axes. An unbalanced weight vibrating device in which the counterweight rotates, and the unbalanced weights on the two parallel axes provided in the vibrating device rotate in the same direction at the same speed while maintaining a predetermined initial phase difference of different phases. In the apparatus for molding a mold having a synchronous rotating means, the table board is inclined in a vertical plane perpendicular to the two parallel axes at a predetermined angle sufficiently smaller than the angle of repose of the molding sand used with respect to the horizontal. the provided, said table plate angle changing means capable
The spring supporting the table board is composed of multiple air springs
Wherein the angle changing means is configured to evacuate the plurality of air springs.
It is characterized in that the air volume is controlled to be inclined .

In this apparatus, the table board can be given a circular vibration along a predetermined vertical plane, and the inclination of the predetermined angle sufficiently smaller than the repose angle of the foundry sand can be given in the vertical plane. In addition, the filling time of the molding sand into the horizontally extending jaw portion or the hollow portion can be greatly reduced as compared with the conventional case. Accordingly, it is possible to shorten the time required for molding a good mold in which the molding sand is reliably filled under the chin portion or in the hollow portion.

[0009] The spring for supporting the table plate, and comprises a plurality of air spring, the angle changing means, a configuration that is inclined by controlling the air amount of said plurality of air springs
In addition, since the spring , which is originally required to allow vibration, has an angle changing function, there is no need to separately provide an angle changing means, and the mold forming apparatus can be provided at a low cost.

[0010] The angle changing means may use a hydraulic cylinder device, a screw device, a link device, or a cam device as an elevating drive mechanism to tilt the table board with a difference in elevation. With this configuration, the angle can be changed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the apparatus used in the method of the present invention will be described. The basic configuration of the apparatus is based on a known circular vibration technique of a vibrating apparatus for filling molding sand (Japanese Patent No. 2872).
No. 099), that is, an apparatus provided with a vibrating table, a vibrating device, and a synchronous rotating device configured to apply a circular vibration to a portion where a mold is formed is provided with a table board angle changing unit. It is a configuration provided. First, a schematic configuration of a device for applying the circular vibration will be described. The vibration table is a spring-supported table board capable of fixing a casting frame on the table board. The vibrating device is a commercially available vibrating motor having a configuration in which a pair of vibrators are attached to the lower surface of a table board, and the vibrators are provided with rotationally unbalanced weights on the rotating shaft of the electric motor. A vibrator is mounted on the lower surface of the table board so that each axis is horizontal and parallel, and each weight rotates in the same direction at a constant speed. The synchronous rotating means is provided with a synchronous means so that the two weights rotate synchronously while maintaining an initial phase difference (preferably within a range of 30 ° to 150 °), for example, 90 °. For example, a toothed pulley is attached to a motor shaft, and a timing belt is hung on the toothed pulley. With this configuration, when the vibration motor operates, circular vibrations such as drawing a minute circle along a plane perpendicular to the motor shaft are applied to the table board, the casting frame, and the like substantially uniformly.

As shown in FIG. 1, a first embodiment of a mold making apparatus 1 comprises a vibration table 2 as a device for applying the above-described circular vibration and a vibration device 3 provided with a synchronous rotating means.
And a table board angle changing means 4 is separately provided. The vibration table 2 includes a table board 10
Is formed on the upper surface so that the flask 11 can be fixed, and is supported on the base 13 by a spring 12 so as to be able to vibrate together with the fixed flask 11. The spring 12
For example, a rectangular table board 10 made of an air spring
Are provided so as to support the four corners of the lower surface of each.
The vibration device 3 provided with the synchronous rotation means is a circular vibration unit provided with a pair of vibrators so that the motor shaft thereof is perpendicular to the plane of FIG.
The paper surface is a vertical plane, and gives a circular vibration along the vertical plane.

The table board angle changing means 4 adjusts the air amount of the two air springs 12 on one side of the four air springs 12 (or the air springs 12 of all four air springs 12) to adjust the air amount on one side (or both sides). ) To change the support height and tilt. The inclination angle θ can be arbitrarily changed within a range of 1 ° to 10 ° to the positive and negative sides (in the upward and downward directions, respectively) with respect to the horizontal in the vertical plane. This angle range is for testing, and 1 ° to 5 ° is sufficient for practical use.

The second embodiment shown by the mold making apparatus 1a differs from the first embodiment in the table board angle changing means as shown in FIG. 2 and will be described. The table board angle changing means 4a is provided below the first table board 10a to which the casting frame 11 is fixed.
b, the first table board 10a is axially connected to the second table board 10b with the shaft 15 so that the first table board 10a can incline about the shaft 15 on one side, and a hydraulic cylinder 16 is interposed on the other side. The tilt angle can be arbitrarily changed in the range of 1 ° to 5 ° to the positive and negative sides with respect to the horizontal by the hydraulic cylinder 16. As another device for giving a circular vibration, a vibration table 2 and a vibration device 3 provided with a synchronous rotating means are provided in the same manner as in the first embodiment. Description is omitted. The air spring 12 shown in FIG. 2 may be replaced with a coil spring.

The third embodiment shown by the mold making apparatus 1b also differs from the first embodiment in the table board angle changing means as shown in FIG. The table board angle changing means 4b includes a second base 1 below the first base 13a.
3b, and the first base 13 with respect to the second base 13b.
a is axially coupled to one side of the shaft 20 so as to be tiltable about the axis 20, and a hydraulic cylinder 21 is interposed on the other side, and the tilt angle of the hydraulic cylinder 21 is 1 ° to the positive and negative sides with respect to the horizontal. It can be arbitrarily changed within a range of up to 5 °. The configuration of the other parts is the same as that of the first or second embodiment, and the same parts are denoted by the same reference numerals.

In the second and third embodiments, the hydraulic cylinders 16 or 21 are mounted on the table board angle changing means 4a, 4b.
However, as other lifting / lowering driving devices, a screw driving device corresponding to a screw jack, a cam driving device, a device for driving a rack with a pinion, a hydraulic cylinder and a screw for a lifting / lowering mechanism using a link. Can be used.

A comparative test was conducted between the case where the table board 10 and the casting flask 11 were given a predetermined inclination angle using the apparatus of the first embodiment (the method of the present invention) and the case where no inclination angle was given. Table 1 shows the conditions and results of the above. In the comparative test, the casting frame 1 clamped to the upper surface of the table board 10 was used.
In FIG. 1, a dry sand 24 and a transparent acrylic T-tube 25 are set horizontally as shown in FIG.
5 compares the filling time until the dry sand completely fills the horizontal hole 25a. Acrylic T-tube 25
This is a test casting model in which the filling state of the sand can be observed from the outside, and a wooden mold, a mold, or a foam model is used for actual molding. Also,
The protruding end of the acrylic T-shaped tube 25 is closed to confirm that the molding sand can be filled to the inside of the horizontal tube. An inclination angle θ at which the closed end side is inclined downward is given. In addition, the rotation direction of the motor, that is, the rotation direction of the unbalanced weight is counterclockwise when the inclination angle is downward right.

[0018]

[Table 1]

According to Table 1, those having a tilt angle of 3 ° have a tilt angle of 0.
It can be seen that the filling can be performed in one-fourth the time in the case of °.
In a test performed separately from the above test, when only the rotation of the motor was reversed, filling was performed in the same time, but the filling density seemed to be slightly lower. If only the inclination angle is reversed so that the end side of the T-tube 25 in the protruding direction, that is, the closed end side, becomes higher, filling can be performed substantially in the same time, but high-density filling does not occur. Therefore, the time is slightly extended for high-density filling, but may be extended for about 2 to 3 seconds. Further, the tendency that the packing density decreases becomes larger as the inclination angle θ is increased. For this reason, the inclination angle is preferably in the range of 1 ° to 5 ° at which the packing density does not change much in the same time, and generally about 3 ° is appropriate. This 1 ° ~
The value of 5 ° is much smaller than the angle of repose of the foundry sand (about 25 °). Further, in the actual cast model of the T-tube, the horizontal protruding end is not closed in the installation state in the casting flask. However, the test result is obtained by giving an inclination angle of 1 ° to 5 °. It can be proved that the casting sand can be filled into the horizontal hole in a much shorter time than before.

The same apparatus is used, and instead of the dry sand, furan sand 32 containing 0.7% of furan (having the same viscosity as molding sand containing a 40% hardener) is used as a self-hardening sand. As a model, a block-shaped foam model 30 having a H-shaped cross section and a predetermined length as shown in FIG. 5 is prepared, and a front wall of the flask 11 is formed of a transparent acrylic plate so that the inside can be observed. Then, as shown in the figure, set the model 30 sideways so that the H-shape is horizontal, and set it so that the end face coincides with the front wall. The filling time before the filling was compared. The vibration conditions were set to a circular motion with a horizontal acceleration of 2.5 G and a horizontal amplitude of 0.4 mm. As a result, when the inclination angle was 0 °, the filling time was 60 seconds, whereas when the inclination angle was 3 °, the filling time was 15 seconds. In the case of furan sand, the sand on the left side is slightly hard to clog because the vibrating force is strong. Although not necessary in the case of dry sand, if the inclination is reversed about two or three times (if reversed), the sand is completely filled on both the left and right sides. Therefore, it can be seen that time reduction is effective also in molding of a mold using self-hardening molding sand.

[0021]

The invention of claim 1 according to the present invention, the jaw subordinates foundry sand mold model, time to molding a good mold is reliably filled in the hollow portion or the like, can at shorter than conventional molding time ,
Since the inclination angle of the table board is small, there is an effect that almost no inconvenience due to the inclination occurs. According to the invention of claim 2, the time required for forming a good mold in which the molding sand is reliably filled under the chin portion and the hollow portion of the casting model is reduced by the conventional molding method.
Can at shorter than the mold time, the spring required to allow the original vibration, because I at an angle changing function, it is not necessary to provide an angle changing means separately, an effect of providing a correspondingly casting mold making system inexpensively Sosu that.

[Brief description of the drawings]

FIG. 1 is a front view showing a schematic configuration of a first embodiment of an apparatus of the present invention.

FIG. 2 is a front view showing a schematic configuration of a second embodiment of the apparatus of the present invention.

FIG. 3 is a front view showing a schematic configuration of a third embodiment of the apparatus of the present invention.

FIG. 4 is a schematic explanatory view when the method of the present invention uses dry foundry sand.

FIG. 5 is a schematic explanatory view in the case of using a self-hardening molding sand in the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mold making apparatus 2 Vibration table 3 Vibration apparatus 4 Table board angle changing means 10 Table board 11 Cast frame 12 Spring 13 Base 15 Shaft 16 Hydraulic cylinder 20 Shaft 21 Hydraulic cylinder 24 Dry sand 25 Acrylic T-shaped pipe 30 Foaming model 31 Jaws Lower 32 franc sand

Continuing from the front page (72) Inventor Kenichi Kambara 4-1-1 Kanbei-cho, Otsu-ku, Himeji-shi, Hyogo Pref. Inside the Himeji Plant of Nijigi Co., Ltd. Person Yoshihiko Tsukada 1-9-22 Tsuji, Shimizu City, Shizuoka Prefecture Inside Toyo Kikai Seisakusho Co., Ltd. (72) Inventor Shigeki Tsuboi 1-9-22 Tsuji, Shimizu City Shizuoka Prefecture Inside Toyo Kikai Seisakusho Co., Ltd. (56) Reference Document JP-A-2-6143 (JP, U) Patent 2872099 (JP, B2) JP-A-2-14832 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B22C 11/00 -25/00

Claims (2)

(57) [Claims] 1. A casting model is placed in a casting frame fixed on a table board, and casting sand is accommodated. A circular or elliptical substantially circular vibration along a predetermined vertical plane is applied to the table board. In the method of molding a mold for filling with molding sand, the casting model has a form having a solid or hollow extension portion extending horizontally in an installed state in a casting flask, and the extension direction of the extension portion of the casting model is It is installed in the casting frame so as to be in a direction along the predetermined vertical plane, and the table board is at an angle in a range of 1 ° to 5 ° with respect to the horizontal in the predetermined vertical plane.
Wherein the vibration is applied in a state where the mold is inclined. 2. A spring-supported vibrating table for filling molding sand capable of fixing a flask to a table board, and respective rotationally unbalanced weights on two parallel axes provided below the table board rotate. An unbalanced weight type vibrating device,
A synchronous rotating means for rotating in the same direction at a constant speed while maintaining a predetermined initial phase difference in which the unbalanced weights on the two parallel axes are provided in the vibrating device. a table plate angle changing means may be inclined at a sufficiently small predetermined angle than the angle of repose of the molding sand using the table plate with respect to the horizontal in a perpendicular vertical plane to the two parallel axes provided, said table Support the board
A spring having a plurality of air springs,
Changing means for controlling the air amount of the plurality of air springs;
A mold forming apparatus characterized in that it is configured to be inclined .