JP6624178B2 - Core molding equipment - Google Patents

Description

  The present invention relates to a core molding apparatus.

  In Patent Document 1, in a mold making apparatus, an injection hole is provided in a bottom plate, a function as a stirring tank for stirring particulate aggregate, a water-soluble binder, and water, and a foamed mixture obtained by stirring are press-fitted. It is disclosed that a mixture storage means having both a function as a press-fitting cylinder at the time of the injection and a plug means capable of closing an injection hole is provided.

International Publication No. WO 2005/089884

  In the mold making apparatus described in Patent Literature 1, when the kneading process is completed, the closing by the plug means is canceled and the mixture storage means is moved to a position directly above the molding die. May leak. Then, the inventor considered laying a wire net in the injection hole in order to prevent such leakage when molding the core.

  However, the mesh of the wire mesh must be narrowed due to the high fluidity of the mixture, and in a structure in which such a wire mesh is laid in the injection hole, the mixture (kneaded foamed sand) passes through the wire mesh during injection. The fluidity is lost due to defoaming, and the sand around the inside of the molding die may be defective. Therefore, there is a demand for a core molding apparatus having a structure that prevents both material leakage during movement and deterioration of the fluidity of the injected material (the mixture).

  Therefore, an object of the present invention is to provide a core molding apparatus capable of preventing material leakage during movement and preventing deterioration of fluidity of injected material.

One embodiment of the present invention to achieve the above object,
A kneading tank for kneading the raw materials of the core,
Kneading means for kneading the raw materials in the kneading tank to obtain a mixture,
By pressing the mixture from above in a state where the kneading unit is retracted from the kneading tank, a pressing unit that press-fits the mixture from the kneading tank into a molding die,
A core molding apparatus having
At the bottom of the kneading tank, has an injection hole for injecting the mixture,
An elastic plate having a slit is disposed in the injection hole,
At least after the mixture has been obtained, and before the pressing of the mixture by the pressing means is started, the elastic body plate remains substantially undeformed,
When the pressing of the mixture by the pressing means is started, the elastic body plate is deformed to open the slit, and the mixture is ejected from the slit.
It is a core molding device.

  According to the core molding apparatus according to this aspect, the injection hole formed in the bottom is provided with the elastic plate having the slit, and the slit is opened when the mixture of the raw materials is pressed into the molding die. (1) The slit closes during the movement of the apparatus to prevent material leakage, and (2) during injection, the slit opens to prevent deterioration of the fluidity of the material. Therefore, according to this aspect, it is possible to provide a core molding apparatus capable of preventing material leakage during movement and preventing deterioration of fluidity of injected material.

  Advantageous Effects of Invention According to the present invention, it is possible to provide a core molding apparatus capable of preventing material leakage during movement and preventing deterioration of fluidity of injected material.

It is an outline sectional view showing an example of 1 composition of a core molding machine concerning one embodiment of the present invention. FIG. 2 is a schematic sectional view showing a portion functioning as a kneading device in the core molding machine of FIG. 1. FIG. 2 is a schematic cross-sectional view showing a state when a kneading tank moves in the core molding machine of FIG. 1. FIG. 2 is a schematic sectional view showing a portion functioning as an injection device in the core molding machine of FIG. 1. It is a figure which shows an example of the elastic body plate arrange | positioned at the injection hole of the kneading tank in FIGS. 1-4. FIG. 6 is a diagram showing a state in which the elastic plate of FIG. 5 is deformed. FIG. 6 is a cross-sectional view illustrating a state in which the elastic body plate of FIG. 5 is kneaded. FIG. 6 is a cross-sectional view illustrating a state in which the elastic plate of FIG. 5 moves. FIG. 6 is a cross-sectional view showing a state of the elastic plate of FIG. 5 at the time of injection. It is a figure which shows the other example of the elastic body plate which can be arrange | positioned at the injection hole of the kneading tank in FIGS. 1-4.

  Hereinafter, a core molding apparatus (core molding machine) according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view showing one configuration example of a core molding machine according to the present embodiment. As shown in FIG. 1, the core molding machine 1 according to the present embodiment includes a kneading tank 10, a kneading unit 11, and a pressing unit 15. The kneading tank 10 and the kneading unit 11 are provided to function as a kneading device, and the pressing unit 15 is provided to function together with the kneading tank 10 as an injection device.

  Next, each component of the core molding machine 1 will be specifically described with reference to FIGS. 2 is a schematic cross-sectional view showing a portion functioning as a kneading device in the core molding machine 1, FIG. 3 is a schematic cross-sectional view showing a state where the kneading tank in the core molding machine 1 is moved, and FIG. 4 is a core molding machine. FIG. 2 is a schematic sectional view showing a part functioning as an injection device in FIG.

As shown in FIG. 2, the kneading tank 10 is a container (pot) having an opening at an upper part thereof, and is used for kneading a core raw material (core material) So. The kneading tank 10 is a tank for stirring the core material So for kneading, and may be referred to as a stirring tank. As the core material So, particulate aggregate, water, a water-soluble inorganic binder, and a surfactant can be used, but not limited thereto. For example, an organic binder can be used instead of the inorganic binder. However, it can be said that a core (inorganic core) formed by using an inorganic binder is more preferable in terms of odor at the time of curing, collapse, etc., CO ₂ emission, and the like.

  The kneading means 11 is means for kneading the core material So in the kneading tank 10 to obtain a mixture S (see FIG. 3). The mixture S is foamed sand obtained by kneading the particulate aggregate as the core material So and the other auxiliary materials as described above, and may be referred to as foamed sand or kneaded sand. The kneading means 11 has a rotary motor (not shown) and a kneading blade 11a. The kneading blade 11a is a mesh-shaped stirring member that is inserted from the opening of the kneading tank 10 and is rotated about a rotating shaft 11b by a rotary motor. Further, the core molding machine 1 includes an elevating mechanism (not shown) for raising and lowering the kneading blades 11a in order to put the kneading blades 11a in and out through the opening of the kneading tank 10.

  In addition, the bottom of the kneading tank 10 has an injection hole 12 for injecting the mixture S when the mixture S described below is pressed into the molding die 2. Further, the injection hole 12 can be sealed with a stopper 14 from below. The stopper 14 is made of rubber, but may be made of metal or the like. The sealing with the stopper 14 is performed in a kneading step in which the core material So is kneaded in the kneading tank 10 by the kneading means 11. As will be described in detail later, the injection hole 12 is provided with an elastic plate 13 having a slit. The sealing with the plug 14 is actually performed by closing the slit while the elastic body plate 13 is deformed.

  Further, in the core molding machine 1, after the kneading process is completed, the kneading tank 10 is moved to the place where the molding die 2 is installed as shown by a dotted horizontal arrow in FIG. (Not shown). During this movement, as shown in FIG. 3, the kneading blade 11a is taken out, and the stopper 14 is taken out.

  The pressing means 15 shown in FIGS. 1 and 4 is a means for pressing the mixture S from above in the injection step. The injection step is a step of injecting the mixture S from the injection hole 12 in a state where the kneading tank 10 has been moved to the installation location of the molding die. The pressing means 15 makes the kneading tank 10 function as a press-fit cylinder (cylinder), and has a piston (injection piston) 15 a having a pressing surface having the same diameter as the inner diameter of the kneading tank 10. The pressing means 15 presses the mixture S from the kneading tank 10 into the molding die 2 by pressing with the injection piston 15a. Therefore, the position and the shape of the injection hole 12 are adjusted to the position and the shape of the inlet of the mixture S in the molding die 2. The molding die 2 has dies 21 and 22 for forming a cavity C according to the shape of a core to be molded.

  As described above, the kneading tank 10 functions not only as a pot for kneading the core material, but also as a cylinder for pressing the mixture S obtained by kneading the core material So into the molding die 2. It also has functions. That is, the core molding machine 1 is a device having both a function as a kneading tank and a function as a cylinder, kneading the core material So, and pressing the mixture S obtained by kneading into the molding die 2.

  Next, the elastic body plate 13, which is one of the main features according to the present embodiment, will be described with reference to FIGS. FIG. 5A is a top view showing an example of the elastic body plate 13, and FIG. 5B is a side view thereof. FIG. 6A is a top view showing a state in which the elastic plate 13 of FIG. 5A is deformed, and FIG. 6B is a schematic side view thereof. FIGS. 7, 8, and 9 are cross-sectional views showing states of the elastic plate 13 of FIGS. 5A and 5B during kneading, moving, and injection, respectively.

  As shown in FIGS. 5A and 5B, the elastic plate 13 is a rubber plate having a slit 13a, and the shape of the slit 13a (the opening shape by the slit 13a) is changed by its elasticity. Can be. The slit 13a is a cross-shaped slit when not deformed. The elastic body plate 13 is disposed in the injection hole 12 as described above, and is held so as to close the injection hole 12 at the bottom of the kneading tank 10, for example. The outer shape of the elastic plate 13 may be any shape as long as it can be disposed in the injection hole 12.

The change in the shape of the elastic plate 13 will be described for each process.
First, in the kneading step, the kneading blades 11a are inserted into the kneading tank 10 from the opening thereof, and the stoppers 14 are inserted into the injection holes 12 from below to prevent the core material So from leaking. Actually, since the elastic body plate 13 is disposed in the injection hole 12, the stopper 14 is inserted into the slit 13a from below as shown in FIG. 7, and the slit 13a is deformed and expanded by that amount. Thereby, the injection hole 12 is in a sealed state. The stopper 14 may be shaped so as to close the slit 13a without deforming the elastic body plate 13. After the completion of the kneading step, the kneading blades 11a are removed from the kneading tank 10, and the stopper 14 is removed.

  In the moving step, the kneading tank 10 is moved to a place where the molding die 2 is installed. As described above, before the movement, the stopper 14 is removed, and the kneading blade 11a is also removed. Thereby, in the moving step, the slit 13a of the elastic body plate 13 is not widened by the plug 14, so that the elastic body plate 13 does not receive any extra pressure due to the rotation of the kneading blades 11a and only the weight of the mixture S is applied. . Therefore, during the movement, the elastic body plate 13 is in the original state (non-deformed state) as shown in FIGS. Although the description has been given on the assumption that the kneading blade 11a is taken out before the movement, the kneading blade 11a may be taken out at least before the start of the injection step. It may be. Similarly, the plug 14 only needs to be removed at least before the start of the injection step. For example, the plug 14 may be removed in the middle of the movement path.

  As described above, in the core molding machine 1, the elastic body is provided at least after the mixture S is obtained (after the kneading process is completed) and before the pressing of the mixture S by the pressing means 15 is started. The plate 13 is kept substantially undeformed. Here, “not substantially deformed” means that the mixture S is not deformed to the extent that the mixture S does not leak.

  The injection step (filling step) is performed in a state where the kneading means 11 is retracted from the kneading tank 10 (a state in which the kneading blades 11a are removed from the kneading tank 10). In the injection step, when the pressing of the mixture S by the injection piston 15a is started, the elastic plate 13 arranged in the injection hole 12 is deformed as shown in FIGS. 6 and 9, and the slit 13a opens (spreads). . The mixture S is ejected therefrom. Then, as the injection piston 15a descends, the injected mixture S is press-fitted into the cavity C formed by the molds 21 and 22, and is filled.

  Further, the elastic modulus of the elastic body plate 13 and the shape of the slit 13a are set so that the above-described deformation can be performed according to the pressing force of the pressing means 15, the shape of the injection hole 12, the weight of the core material So, and the like. You only have to decide.

  As described above, in the core molding machine 1, the elastic plate 13 having the slit 13 a in the injection hole 12 is provided. Thereby, the core molding machine 1 can physically hold the mixture (foamed sand) S having high fluidity by moving the kneading tank 10 by closing the slit 13a. Can prevent sand leakage while moving. Further, the core molding machine 1 is smaller than the opening of the slit 13a at the time of injection into the molding die 2, as compared with the case where (2) a member having a large shear resistance such as a wire mesh is disposed in the injection hole 12. Since the mixture S can be pressed into the molding die 2 while the foaming is maintained by the shear resistance, the mixture S can be put into the molding die 2 without deteriorating the fluidity. That is, it can be said that the core molding machine 1 according to the present embodiment has a structure that prevents both material leakage during movement and deterioration in fluidity during injection.

Next, alternative examples and preferred examples in the present embodiment will be described.
The kneading means 11 is not limited to the examples shown in FIGS. 1 and 2 and may have kneading blades of other shapes. For example, a plurality of stirring units extending in the kneading tank 10 in the vertical direction may be used. A stirrer having a pin and a rotating base serving as a base for rotating the pins about a vertical axis may be used. Further, the pressing means 15 is not limited to the examples shown in FIGS. 1 and 4, and may be, for example, means for sending compressed air.

  In addition, an example was described in which the kneading tank 10 was moved by the moving mechanism after the kneading step was completed. However, instead of this moving mechanism, a mechanism for moving the kneading means 11 and the injection piston 15a of the pressing means 15 after the kneading step is completed without moving the kneading tank 10 may be provided.

  Regardless of the number, shape, and horizontal position of the injection holes 12 provided in the kneading tank 10, the number of the injection holes 12 is determined by the number and shape of the inlets of the mixture S provided on the molding die 2. , And the position. When a plurality of injection holes 12 are provided, an injection plate having the plurality of injection holes 12 arranged on a plate may be provided at the bottom of the kneading tank 10. When a plurality of injection holes 12 are provided, a stopper plate provided with a plurality of stoppers can be used as the stopper 14. Further, the elastic body plate 13 does not need to be held at the bottom of the kneading tank 10, and may be arranged in the vertical direction of the injection hole 12 or at the exit of the injection hole 12.

  Further, instead of the elastic plate 13, an elastic plate 16 as shown in FIG. 10 can be adopted. FIG. 10A is a top view showing another example of the elastic body plate, FIG. 10B is a side view at the time of kneading and moving, and FIG. 10C is a side view at the time of injection. The core molding machine provided with the elastic body plate 16 will be described focusing on the differences from the core molding machine 1 shown in FIG. 1 and the like, but the other points are the same as those of the core molding machine 1. is there.

  As shown in FIG. 10A, the elastic body plate 16 is a metal plate (metallic spiral plate) having a spiral slit 16a. Like the elastic plate 13, the elastic plate 16 has such a rigidity that the central portion is lowered at the time of injection and the mixture S can be injected. On the other hand, unlike the elastic body plate 13, the elastic body plate 16 has a rigidity enough to withstand the pressure at the time of kneading (the weight of the core material So at the time of kneading) and not to be deformed.

  Therefore, as shown in FIG. 10B, the elastic plate 16 is not deformed in the kneading step and the moving step. On the other hand, as shown in FIG. 10 (c), in the elastic body plate 16, the central portion extends downward and the slit 16a expands in the injection step (the opening portion by the slit 16a expands in the vertical direction). As shown by the bold arrow in FIG. 10C, in the injection step, the mixture S is injected from the spread portion. Since the elastic plate 16 is a metal spring, it returns to its original shape (the state shown in FIG. 10B) by its elastic force after the injection step.

  As described above, the elastic modulus of the elastic body plate 16 and the shape of the slit 16a are determined by the pressing force of the pressing means 15, the shape of the injection hole 12, the weight of the core material So, and the like. What is necessary is just to determine so that the deformation | transformation which spreads in a direction (it will return to the original after completion | finish of injection) is possible.

  The core molding machine having the elastic plate 16 with the slit 16a illustrated here does not leak the core material So even at the time of kneading. Therefore, compared with the core molding machine 1 shown in FIG. The cost can be reduced by eliminating the plug 14. Further, since the core molding machine does not use a rubber cover such as the elastic plate 13 as compared with the core molding machine 1, the durability can be improved, and the number of maintenance steps can be reduced.

  Although the core molding machine has been described above, the components included in the core molding machine are not limited to those shown in the drawings, and may have the functions described for each component.

Although the present embodiment has been described above, the above embodiment has the following features.
That is, the core molding apparatus 1 according to the embodiment includes a kneading tank 10 for kneading the core raw material So, a kneading unit 11 for kneading the raw material So in the kneading tank 10 to obtain the mixture S, Pressing means 15 for pressing the mixture S from above in a state where the means 11 is retracted from the kneading tank 10 to press the mixture S from the kneading tank 10 into the molding die 2. The core molding apparatus 1 has an injection hole 12 at the bottom of the kneading tank 10 for injecting the mixture S, and the injection hole 12 has an elastic plate (for example, a slit 13a having a slit). The elastic plate 13 and the elastic plate 16 including the slit 16a are disposed. In the core molding apparatus 1, at least after the mixture S is obtained, and before the pressing of the mixture S by the pressing means 15 is started, the state in which the elastic plate is not substantially deformed is maintained. When the pressing of the mixture S by the pressing means 15 is started, the elastic plate is deformed to open the slit, and the mixture S is ejected from the slit.

  According to the core molding apparatus having the above configuration, the injection hole formed at the bottom is provided with an elastic plate having a slit, and the slit is opened when the mixture of the raw materials is pressed into the molding die, (1) During the movement of the apparatus, the slit closes to prevent material leakage, and (2) at the time of injection, the slit opens to prevent deterioration of the fluidity of the material. That is, according to the core molding apparatus having the above-described configuration, it is possible to prevent the material from leaking during the movement and to prevent the fluidity of the injected material from deteriorating. In addition, according to this core molding apparatus, since material leakage can be prevented, it is possible to prevent a reduction in the operation rate due to equipment failure and cleaning, and a deterioration in the working environment. It is possible to prevent the core from being incompletely filled and to prevent the surface roughness from becoming rough, thereby improving the quality of the core.

C cavity S mixture (kneading sand)
So core material (core material)
1 core molding machine (core molding machine)
2 Molding die 10 Kneading tank 11 Kneading means 11a Kneading blade 11b Rotary shaft 12 Injection hole 13 Elastic plate 13a Cross-shaped slit 14 Plug 15 Pressing means 15a Injection piston 16 Elastic plate (made of metal)
16a Spiral slit 21, 22 type

Claims (3)

A kneading tank for kneading the raw materials of the core,
Kneading means for kneading the raw materials in the kneading tank to obtain a mixture,
By pressing the mixture from above in a state where the kneading unit is retracted from the kneading tank, a pressing unit that press-fits the mixture from the kneading tank into a molding die,
A core molding apparatus having
At the bottom of the kneading tank,
An injection hole that is provided so as to protrude vertically downward from the bottom of the kneading tank, and injects the mixture in the kneading tank ,
An elastic plate disposed to close the injection hole at the bottom in the kneading tank ;
Is provided,
A cut is formed in the elastic plate, and when the mixture is pressed by the pressing means, a cut in the elastic plate is opened and the mixture passes through the elastic plate and is ejected from the injection hole. ,
Core molding equipment.   The core molding device according to claim 1, wherein the cut formed in the elastic plate has a cross shape when the elastic plate is viewed in a plan view. The injection hole is configured to be sealable by inserting a plug from below,
The stopper is inserted into a cut of the elastic plate, and the stopper is fixed by deforming the elastic plate.
The core molding apparatus according to claim 1.

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