WO2018016123A1

WO2018016123A1 - Mold forming method

Info

Publication number: WO2018016123A1
Application number: PCT/JP2017/010595
Authority: WO
Inventors: 昌秀野口
Original assignee: 新東工業株式会社
Priority date: 2016-07-20
Filing date: 2017-03-16
Publication date: 2018-01-25
Also published as: KR20190027777A; EP3488945B1; JP6665935B2; BR112018074860A2; US20190111474A1; MX2018014692A; EP3488945A1; CN109195729A; JPWO2018016123A1; CN109195729B; EP3488945A4

Abstract

The purpose of the present invention is to provide a mold forming method that can partially increase the density of a mold even in locations wherein a pattern is concave with respect to a parting surface and can make the density of the mold substantially uniform. Provided is a mold forming method for forming a mold of casting sand using a casting frame and a pattern plate, comprising: a step for forming a forming space using the casting frame, a molding flask having a lower opening connectable to an upper opening in the casting frame, a squeeze head mechanism having a squeeze board capable of entering and withdrawing from the molding flask and a plurality of squeeze feet penetrating the squeeze board and being capable of being raised and lowered relative to the squeeze board, and the pattern plate; a step for filling the forming space with casting sand within a casting sand filling hopper for storing casting sand; and a step for lowering the squeeze head mechanism and squeezing the casting sand. Simultaneously with the start of the squeezing step or during the squeezing step, the squeeze feet are lowered facing the concave pattern part formed in the pattern plate.

Description

Mold making method

The present invention relates to a mold making method in which a casting mold filled in a casting frame is squeezed to mold a mold.

Conventionally, in order to make the mold density almost uniform, when forming the molding space of the mold, in the part where the height of the model part is high, the amount of foundry sand that is compressed by lowering the squeeze foot is reduced. It is publicly known to increase the amount of molding sand to be compressed while the squeeze foot remains elevated at a portion where the height of the squeeze is low (see, for example, Patent Document 1).

However, the above-described method has an effect when the model part is convex with respect to the parting surface, but is not effective when the model part is concave with respect to the parting surface (such as a pocket shape). .

The present invention has been made in view of the above problems, and even if the model part is a concave part with respect to the parting surface, the density of the mold can be partially increased, and the density of the mold is almost uniform. It is an object of the present invention to provide a mold making method that can be used.

JP 2001-38451 A

In order to achieve the above object, the mold making method of the present invention is a mold making method in which a mold is formed with foundry sand using a casting frame and a pattern plate, the casting frame and an upper opening of the casting frame. And a squeeze head having a plurality of squeeze feet that pass through the squeeze board and can be moved up and down with respect to the squeeze board. A step of forming a molding space using a mechanism and the pattern plate, a step of filling the molding space in the sand filling hopper for storing the molding sand into the molding space, and lowering the squeeze head mechanism. A step of squeezing the foundry sand, and formed on the pattern plate simultaneously with the start of the squeeze step or during the squeeze step. Wherein the lowering the squeeze feet facing the mold cavity.

Further, the mold making method of the present invention is characterized in that the operating pressure for lowering the squeeze foot facing the model recess formed in the pattern plate can be changed to a desired pressure.

Further, in the mold making method of the present invention, the squeeze pressure for squeezing the foundry sand in the squeeze step is measured, and when the measured squeeze pressure reaches a preset pressure, the mold is formed on the pattern plate. The descent of the squeeze foot facing the model recess is started.

Furthermore, the mold making method of the present invention measures the descending distance of the squeeze head mechanism for squeezing the foundry sand in the squeezing step, and when the measured descending distance reaches a preset distance, the pattern plate The descent of the squeeze foot that faces the model recess formed in is started.

Furthermore, the mold making method of the present invention is characterized in that, in the step of forming the molding space, the squeeze foot facing the model convex portion formed on the pattern plate is lowered and then the filling step is performed. And

Further, in the mold making method of the present invention, after the filling step, the step of squeezing the squeeze foot while raising the squeeze foot facing the model convex portion formed on the pattern plate is performed. It is characterized by that.

Further, the mold making method of the present invention includes a frame-like frame that surrounds the outer periphery of the pattern plate and slides up and down, and the molding space is partially formed by the frame-like frame. .

The present invention is a mold making method in which a casting mold and a pattern plate are used to mold a casting mold with foundry sand, the casting frame, and a filling frame having a lower opening that can be connected to the upper opening of the casting frame. A squeeze board that can enter and exit into the fill frame, a squeeze head mechanism that has a plurality of squeeze feet that pass through the squeeze board and can be raised and lowered with respect to the squeeze board, and a patterning space using the pattern plate A step of filling the molding space with the molding sand in a sand filling hopper for storing the molding sand, and a step of lowering the squeeze head mechanism to squeeze the molding sand. Simultaneously with the start of the squeeze step or in the middle of the squeeze step, the squeeze foot facing the model recess formed in the pattern plate is lowered. Therefore, even if the model part is concave with respect to the parting surface, the density of the mold can be partially increased, and the mold density can be made almost uniform. is there.

This application is based on Japanese Patent Application No. 2016-142452 filed on July 20, 2016 in Japan, the contents of which form part of the present application.
The present invention will also be more fully understood from the following detailed description. However, the detailed description and specific examples are preferred embodiments of the present invention and are described for illustrative purposes only. This is because various changes and modifications will be apparent to those skilled in the art from this detailed description.
The applicant does not intend to contribute any of the described embodiments to the public, and the disclosed modifications and alternatives that may not be included in the scope of the claims are equivalent. It is part of the invention under discussion.
In this specification or in the claims, the use of nouns and similar directives should be interpreted to include both the singular and the plural unless specifically stated otherwise or clearly denied by context. The use of any examples or exemplary terms provided herein (eg, “etc.”) is merely intended to facilitate the description of the invention and is not specifically recited in the claims. As long as it does not limit the scope of the present invention.

It is a schematic structure sectional view showing an embodiment of the present invention, and is a figure showing the state where molding space was formed. It is a general | schematic structure sectional drawing which shows the state which lowered | hung the squeeze foot which opposes a model convex part to the predetermined position. It is an outline composition sectional view showing the aeration filling state of foundry sand. It is a general | schematic structure sectional drawing which shows the state which raised the squeeze foot facing a model convex part to the raise end. It is an outline composition sectional view showing the state where squeeze of foundry sand was completed. It is sectional drawing which shows the casting frame in which the casting_mold | template was shape | molded. It is a general | schematic structure sectional drawing which shows the state in which the molding space at the time of using another pattern carrier was formed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, an example is shown in which a mold making apparatus with a frame that alternately forms upper and lower molds into upper and lower casting frames is used as the mold making apparatus. FIG. 1 is a schematic sectional view showing an embodiment of the present invention, and mainly shows a sand filling part and a squeeze part in a mold making apparatus. For this reason, illustration is abbreviate | omitted about the components of the mold making apparatus other than a sand filling part and a squeeze part.

In FIG. 1, a pattern plate (model plate) 2 for an upper casting frame is detachably mounted on the pattern carrier 1 in a state of surrounding the outer periphery thereof. A cast frame 3 is placed on the pattern carrier 1 (on the pattern plate 2). The casting frame 3 is carried into or out of the apparatus by a carry-in / out conveyor (not shown). The casting frame 3 is raised and lowered by a casting frame raising / lowering means (not shown).

On the casting frame 3, a filling frame 4 having a lower opening 4a connectable with the upper opening 3a of the casting frame 3 is pressed and adhered. The filling frame 4 is moved up and down by filling frame lifting / lowering means (not shown). An encoder (not shown) is attached to the fill frame 4, and the elevation distance of the fill frame 4 can be measured by this encoder. FIG. 1 shows a state where the upper opening 3a of the casting frame 3 and the lower opening 4a of the filling frame 4 are connected (communication).

The lower end of a sand filling hopper 5 for storing foundry sand (green sand in this embodiment) S is inserted into the filling frame 4. A squeeze head mechanism 6 is attached to the lower end of the sand filling hopper 5 and inserted into the fill frame 4. The squeeze head mechanism 6 includes a squeeze board 7 that can be moved up and down within the filling frame 4, and a plurality of segment-type squeeze feet 8 that pass through the squeeze board 7 and can be moved up and down with respect to the squeeze board 7. . In the present embodiment, the plurality of squeeze feet 8 are operated by hydraulic pressure (lifting and lowering method using a hydraulic cylinder).

The sand filling hopper 5 is provided with a sand inlet 10 which is opened and closed by a slide gate 9 at the upper end, and introduces low-pressure air (for example, 0.05 to 0.18 MPa) to the upper part via an on-off valve 11. An air supply pipe 12 is communicated. The lower portion of the sand filling hopper 5 is composed of a bifurcated chute 13. On the inner surface of the sand-filling hopper 5, a number of air jets 14 communicating with a compressed air source (not shown) through an on-off valve (not shown) are arranged.

The low-pressure air (for example, 0.05 to 0.18 MPa) is ejected into the sand-filled hopper 5 from a large number of the air outlets 14 to form aeration for floating and fluidizing the foundry sand S. Further, a sand filling port 15 for sending the casting sand S downward from the chute 13 is provided at the lowest part of the chute 13 in the sand filling hopper 5.

A sand filling nozzle 16 is formed on both outer sides of the plurality of squeeze feet 8 in the squeeze board 7 to send the molding sand S to a molding space below the squeeze board 7, and the sand filling nozzle 16 communicates with the sand filling port 15. Has been. The sand filling hopper 5 and the squeeze head mechanism 6 attached to the lower end of the sand filling hopper 5 are moved up and down by a sand filling hopper lifting means (not shown) (a hydraulic cylinder in the present embodiment).

Further, the pattern plate 2 has a model convex part 2a and a model concave part 2b. In the present invention, the model convex part means a part where the height of the model part is higher than the parting surface 2c of the pattern plate 2, and the model concave part means a part where the height of the model part is lower than the parting surface 2c of the pattern plate 2. Say that.

The operation of what is configured in this way will be described. FIG. 1 shows a state in which a molding space is formed by the casting frame 3, the filling frame 4, the squeeze head mechanism 6 and the pattern plate 2. Next, the squeeze foot 8 facing the model convex portion 2a formed on the pattern plate 2 is lowered to a predetermined position, and the state shown in FIG. 2 is obtained. Thereby, the quantity of the foundry sand S squeezed by the squeeze foot 8 which opposes the model convex part 2a can be decreased, and a more preferable molding space is formed.

Next, aeration is performed in which low-pressure air is ejected from a large number of air jets 14 into the sand-filled hopper 5 to float and fluidize the foundry sand S in the sand-filled hopper 5. Low pressure air is supplied from the air supply pipe 12 to the sand-filled hopper 5 through the on-off valve 11 while aeration is performed. As shown in FIG. 3, the molding sand S is aerated by low pressure air into the molding space via the sand filling port 15 and the sand filling nozzle 16. At this time, the low-pressure air during aeration filling is exhausted from a vent hole (not shown) of the fill frame 4.

Next, the squeeze foot 8 facing the model convex part 2a is raised to the rising end. As shown in FIG. 4, the space part 17 without the foundry sand S is formed in the molding space. Next, the sand filling hopper 5 and the squeeze head mechanism 6 are lowered by the sand filling hopper elevating means, and the foundry sand S in the molding space is squeezed by the squeeze board 7 and the plurality of squeeze feet 8. Then, simultaneously with the start of the squeeze step or in the middle of the squeeze step, the squeeze foot 8 facing the model recess 2b formed in the pattern plate 2 is lowered, and the foundry sand S in the model recess 2b is partially removed. (See FIG. 5). The space 17 disappears by squeezing and lowering the squeeze foot 8.

Next, the sand filling hopper 5 and the squeeze head mechanism 6 are raised by the sand filling hopper raising / lowering means, and the casting frame 3 formed with the mold is separated from the squeeze head mechanism 6. Further, the squeeze foot 8 facing the model recess 2b is raised to the rising end. Further, the filling frame 4 is raised by the filling frame raising / lowering means, and the casting frame 3 and the filling frame 4 are separated from each other. Next, the mold is removed by raising the cast frame by the cast frame raising / lowering means, and the cast frame 3 and the pattern plate 2 are separated from each other.

Next, the casting frame 3 in which the mold is formed is carried out by the carry-in / out conveyor, and the empty casting frame 3 is carried in. The casting frame 3 in which the mold is formed is as shown in FIG. Next, the pattern plate 2 is carried out of the apparatus together with the pattern carrier 1 by a pattern exchange apparatus (not shown), and a pattern plate for a lower casting frame (not shown) is carried into the apparatus together with the pattern carrier.

Next, the empty casting frame 3 is lowered by the casting frame raising / lowering means and placed on the pattern plate (pattern carrier) for the lower casting frame. Next, the filling frame 4 is lowered by the filling frame raising and lowering means, and is pressed and brought into close contact with the casting frame 3. Further, the sand filling hopper 5 and the squeeze head mechanism 6 are lowered by the sand filling hopper raising / lowering means so that the squeeze head mechanism 6 is inserted into the filling frame 4. Thereby, a molding space is formed again, and the above operation is repeated.

In the embodiment of the present invention, the operating pressure for lowering the squeeze foot 8 facing the model recess 2b formed in the pattern plate 2 can be changed to a desired pressure. According to this structure, there exists an advantage that the mold-drawing defect of the model recessed part 2b can be prevented by setting this operating pressure to a pressure lower than a predetermined (normal) pressure.

When the casting sand S of the model recess 2b is squeezed more than necessary, and the resistance of the vertical surface (inner peripheral surface) of the model recess 2b is extremely increased, the mold recess of the model recess 2b may occur. In such a case, the operating pressure of the squeeze foot 8 is set to a pressure lower than a predetermined pressure (for example, a pressure that is half of the predetermined pressure), and the die-cutting resistance of the mold on the vertical surface of the model recess 2b is reduced. Thus, it is possible to prevent the mold recess of the model recess 2b.

In the embodiment of the present invention, the squeeze head mechanism 6 is lowered to measure the squeeze pressure for squeezing the foundry sand S. When the measured squeeze pressure reaches a preset pressure, the pattern plate 2 is formed. The squeeze foot 8 facing the model recess 2b is started to descend.

The timing of the descent start of the squeeze foot 8 facing the model recess 2b depends on the model shape, but the casting sand S is usually difficult to be compressed if it is too early. On the other hand, if it is too late, the foundry sand S is already compressed to some extent, so that it becomes difficult to compress the foundry sand S by lowering the squeeze foot 8. According to this configuration, there is an advantage that these problems can be avoided and the descent of the squeeze foot 8 facing the model concave portion 2b can be started at an appropriate timing. In the present embodiment, the squeeze pressure for lowering the squeeze head mechanism 6 to squeeze the foundry sand S is the lowering pressure of the sand filling hopper elevating means for squeezing.

In the embodiment of the present invention, the lowering start timing of the squeeze foot 8 facing the model recess 2b is as described above, but the present invention is not limited to this. For example, the descending distance of the squeeze head mechanism 6 that squeezes the foundry sand S is measured, and when the measured descending distance reaches a preset distance, the squeeze facing the model recess 2b formed in the pattern plate 2 The lowering of the foot 8 may be started.

This configuration also has the advantage that the above-described problem can be avoided and the descent of the squeeze foot 8 facing the model recess 2b can be started at an appropriate timing. In this embodiment, an encoder (not shown) is attached to the sand filling hopper 5, and the descending distance of the squeeze head mechanism 6 can be measured by this encoder.

In the embodiment of the present invention, when forming the molding space, the squeeze foot 8 facing the model convex portion 2a formed on the pattern plate 2 is lowered, and then the molding sand S is filled into the molding space. However, this process may not be performed depending on the shape of the model, and is not essential. When the squeeze foot 8 facing the model convex portion 2a is not lowered, there is naturally no step of raising it.

In the embodiment of the present invention, after the molding sand S is filled in the molding space, the squeeze foot 8 facing the model convex portion 2a formed on the pattern plate 2 is raised, and then the squeeze head mechanism 6 is lowered. The foundry sand S is squeezed. According to this structure, as shown in FIG. 4, the space part 17 without the molding sand S can be formed in a molding space, and the quantity of the molding sand S squeezed on the model convex part 2a decreases. Therefore, there is an advantage that when the squeeze foot 8 facing the model recess 2b is lowered, the foundry sand S on the model recess 2b is easily compressed.

In the present embodiment, as described above, after the squeeze foot 8 facing the model convex portion 2a is raised, the squeeze head mechanism 6 is lowered to squeeze the foundry sand S. However, the present invention is limited to this. It is not a thing. For example, the squeeze head mechanism 6 may be lowered while the squeeze foot 8 facing the model convex part 2a is raised to squeeze the foundry sand S. This has the advantage that the cycle time of the apparatus can be shortened.

Further, the pattern carrier 1 is not limited to the one described above. Here, another embodiment of the pattern carrier will be described. FIG. 7 is a view showing a state where a molding space is formed when another pattern carrier 18 is used. The pattern carrier 18 includes a frame-shaped frame 19 that surrounds the outer periphery of the pattern plate 2 and slides up and down. A plurality of guide pins 20 are connected to the lower part of the frame-shaped frame 19, and the guide pins 20 are inserted into the main body frame 21 so as to be slidable up and down. The frame-shaped frame 19 is moved up and down by a lifting cylinder (not shown) via a guide pin 20. The upper surface of the frame-like frame 19 protrudes slightly (for example, 30 mm) upward from the parting surface 2c of the pattern plate 2 at the extended end of the elevating cylinder (see FIG. 7), and the parting surface 2c of the pattern plate 2 at the contracted end. It is made to become almost the same plane.

In the embodiment shown in FIG. 7, the pattern carrier 18 includes a frame-shaped frame 19 that surrounds the outer periphery of the pattern plate 2 and slides up and down, and a part of the molding space is formed by the frame-shaped frame 19. . According to this configuration, when the foundry sand S in the molding space is squeezed, there is an advantage that the frame-like frame 19 is lowered to squeeze from the model surface side. In addition, since the frame-shaped frame 19 is raised, the molded mold is slightly raised from the stopped state together with the casting frame 3 and is removed, so that there is an advantage that the removal accuracy is high.

In the embodiment of the present invention, the sand filling nozzles 16 are formed on both outer sides of the plurality of squeeze feet 8 in the squeeze board 7, but the present invention is not limited to this. For example, the sand filling nozzle 16 may be formed so as to penetrate the side portion of the filling frame 4. In this case, the bifurcated chute 13 at the lower part of the sand filling hopper 5 may be disposed outside the filling frame 4 and fixed to the filling frame 4. And what is necessary is just to make the sand filling nozzle 15 formed in the side part of the filling frame 4 and the sand filling port 15 provided in the lowest part of the chute | shoot 13 communicate. The squeeze head mechanism 6 may be lifted and lowered by providing an actuator separately. In this case, since the sand filling nozzle 16 is not formed on the squeeze board 7, there is an advantage that the arrangement of the squeeze foot 8 on the squeeze board 7 is not limited.

In the embodiment of the present invention, as shown in FIG. 5, the distance K1 from the lower surface of the squeeze board 7 to the parting surface 2c of the pattern plate 2 when the squeeze is completed, and the lower surface of the squeeze foot 8 facing the model recess 2b. As the distance K2 from the bottom of the model recess 2b to the bottom of the model recess 2b is closer, the mold density is more uniform, which is more preferable.

Below, the main code | symbol used by this specification and drawing is shown collectively.
2 Pattern plate 2a Model convex part 2b Model concave part 3 Cast frame 3a Upper opening part 4 Filling frame 4a Lower opening part 5 Sand filling hopper 6 Squeeze head mechanism 7 Squeeze board 8 Squeeze foot 19 Frame-like frame S Foundry sand

Claims

A mold making method in which a casting mold and a pattern plate are used to mold a mold with foundry sand,
The casting frame, a filling frame having a lower opening that can be connected to the upper opening of the casting frame, a squeeze board that can be put in and out of the filling frame, and the squeeze board through the squeeze board Forming a molding space using a squeeze head mechanism having a plurality of squeezing feet that can be moved up and down, and the pattern plate, and filling the molding space with the foundry sand in a sand filling hopper for storing the foundry sand And a step of lowering the squeeze head mechanism to squeeze the foundry sand,
Simultaneously with the start of the squeeze step or in the middle of the squeeze step, the squeeze foot facing the model recess formed in the pattern plate is lowered,
Mold making method.
The operating pressure for lowering the squeeze foot facing the model recess formed in the pattern plate is changeable to a desired pressure,
The mold making method according to claim 1.
In the squeezing step, a squeeze pressure for squeezing the foundry sand is measured, and when the measured squeeze pressure reaches a preset pressure, the squeeze foot of the squeeze foot facing the model recess formed in the pattern plate is measured. Starting to descend,
The mold making method according to claim 1 or 2.
In the squeezing step, a descending distance of the squeeze head mechanism that squeezes the foundry sand is measured, and when the measured descending distance reaches a preset distance, it faces the model recess formed in the pattern plate. Starting to lower the squeeze foot.
The mold making method according to claim 1 or 2.
In the step of forming the molding space, the squeeze foot facing the model convex portion formed on the pattern plate is lowered, and then the filling step is performed.
The mold making method according to claim 1 or 2.
After the step of filling, after raising the squeeze foot facing the model convex portion formed on the pattern plate, or performing the step of squeezing while raising,
The mold making method according to claim 5.
The frame includes a frame-shaped frame that surrounds the outer periphery of the pattern plate and slides up and down, and the molding space is partly formed by the frame-shaped frame,
The mold making method according to claim 1 or 2.