JPWO2018016123A1 - Mold molding method - Google Patents

Abstract

[Summary] A mold making method is provided which can partially increase the density of a mold even if the pattern part is a concave portion with respect to the parting plane, and can make the density of the mold substantially uniform. A mold forming method for forming a mold with molding sand using a molding frame and a pattern plate, comprising: a molding frame, a filling frame having a lower opening connectable to the upper opening of the molding frame, and entering and leaving the filling frame Of forming a molding space using a squeeze board capable of squeeze board and a squeeze head mechanism having a plurality of squeeze feet that can be moved up and down with respect to the squeeze board, and forming a molding space, and storing casting sand The process of filling the molding sand in the sand filling hopper into the molding space and the process of lowering the squeeze head mechanism to squeeze the molding sand simultaneously with the start of the squeezing process or in the squeezing process In the middle, the squeeze foot opposed to the model recess formed in the pattern plate is lowered. [Selected figure] Figure 1

Description

  The present invention relates to a mold making method for squeezing casting sand filled in a flask to form a mold.

  Conventionally, in order to make the density of the mold substantially uniform, when forming the molding space of the mold, the squeeze foot is lowered at a portion where the height of the model part is high to reduce the amount of molding sand to be compressed, and the model part It is known to increase the amount of molding sand to be compressed while the squeeze foot remains elevated in the lower part of the height (see, for example, Patent Document 1).

  However, the above method is effective when the model part is convex with respect to the parting surface, but is less effective when the model part is concave (pocket shape etc.) with respect to the parting surface .

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

JP 2001-38451 A

  In order to achieve the above object, a mold making method of the present invention is a mold making method for making a mold with casting sand using a flask and a pattern plate, which comprises: the flask; and the upper opening of the flask And a squeeze head having a squeeze board squeeze board capable of moving into and out of the squeeze board, and a plurality of squeeze feet capable of moving up and down with respect to the squeeze board through the squeeze board. Forming a molding space using a mechanism and the pattern plate, filling the molding sand in the sand-filling hopper storing the casting sand into the molding space, and lowering the squeeze head mechanism And squeezing the casting sand, and the pattern formed on the pattern plate simultaneously with the start of the squeezing step or in the middle of the squeezing step. Wherein the lowering the squeeze feet opposite to the recess.

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

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

  Further, according to the mold forming method of the present invention, the descent distance of a squeeze head mechanism for squeezing the casting sand is measured in the squeezing step, and the pattern plate is measured when the measured descent distance reaches a preset distance. Starting lowering of the squeeze foot opposite to the model recess formed in

  Furthermore, the mold making method according to the present invention is characterized in that, in the step of forming the molding space, the step of lowering the squeeze foot facing the model convex portion formed in the pattern plate and thereafter performing the filling step. I assume.

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

  Furthermore, the mold making method of the present invention is characterized by comprising a frame-like frame surrounding the outer periphery of the pattern plate and sliding up and down, and a part of the molding space is formed by the frame-like frame. .

  The present invention is a mold forming method for forming a mold with casting sand using a flask and a pattern plate, which comprises the flask and a lower frame which can be connected to the upper opening of the flask. A squeeze board capable of entering and leaving the fill frame; a squeeze head mechanism having a plurality of squeeze feet which can be moved up and down with respect to the squeeze board through the squeeze board; and a molding space using the pattern plate Forming the casting sand in the sand-filling hopper storing the casting sand, filling the molding space with the casting sand, and lowering the squeeze head mechanism to squeeze the casting sand. Simultaneously with the start of the squeezing step, or in the middle of the squeezing step, lowering the squeeze foot facing the model recess formed in the pattern plate Since the mold portion is made concave, the density of the mold can be partially increased even if the model part is concave with respect to the parting surface, and the density of the mold can be made substantially 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 a part of the contents of the present application.
The invention will also be more fully understood from the following detailed description. However, the detailed description and the specific examples are the preferred embodiments of the present invention and are described for the purpose of illustration only. Various changes and modifications are apparent to those skilled in the art from this detailed description.
The applicant does not intend to provide the public with any of the described embodiments, and among the disclosed modifications, alternatives, which may not be literally included within the scope of the claims, is equivalent. As part of the invention under discussion.
In the description or the description of the claims, the use of nouns and similar indicators should be construed as including both the singular and the plural unless the context clearly dictates otherwise. The use of any of the exemplary or exemplary terms (eg, "such as") provided herein 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 the 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 the squeeze foot which opposes a model convex part to a predetermined | prescribed position. It is a general | schematic structure sectional drawing which shows the aeration filling state of casting sand. It is a general | schematic structure sectional drawing which shows the state which raised the squeeze foot which opposes a model convex part to the raising end. It is a general | schematic structure sectional drawing which shows the state which the squeeze of the casting sand completed. It is a cross-sectional view showing a flask in which a mold is formed. 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 based on the drawings. In this embodiment, an example using a framed mold forming apparatus for alternately forming upper and lower molds into upper and lower flasks is shown as the mold forming apparatus. FIG. 1 is a schematic sectional view showing an embodiment of the present invention, mainly showing a sand filling portion and a squeeze portion in a mold making apparatus. For this reason, illustration is abbreviate | omitted about the component of the mold making apparatuses other than a sand filling part and a squeeze part.

  In FIG. 1, a pattern plate (model plate) 2 for an upper flask is detachably mounted on a pattern carrier 1 in a state of being surrounded by the outer periphery thereof. The flask 3 is placed on the pattern carrier 1 (pattern plate 2). The flask 3 is carried in or out of the apparatus by a conveyor (not shown). Further, the flask 3 is moved up and down by a frame lifting means (not shown).

  On the flask 3, a filling frame 4 having a lower opening 4a connectable to the upper opening 3a of the flask 3 is pressed in close contact. The filling frame 4 is moved up and down by a filling frame lifting means (not shown). An encoder (not shown) is attached to the filling frame 4 and the elevating distance of the filling frame 4 can be measured by this encoder. FIG. 1 shows a state in which the upper opening 3a of the flask 3 and the lower opening 4a of the fill frame 4 are connected (communicated).

  The lower end of the sand filling hopper 5 storing the casting sand (in this embodiment, green sand) S is inserted into the filling frame 4. A squeeze head mechanism 6 is mounted at the lower end of the sand filling hopper 5 and inserted into the filling frame 4. The squeeze head mechanism 6 has a squeeze board 7 which can move up and down in the fill frame 4 and a plurality of squeeze feet 8 of a segment system which can move up and down with respect to the squeeze board 7 through the squeeze board 7. . In the present embodiment, the plurality of squeeze feet 8 are operated by hydraulic pressure (raising and lowering method by 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 low pressure air (for example, 0.05 to 0.18 MPa) is introduced to the upper part via the on-off valve 11 The air supply pipe 12 is in communication. The lower part of the sand filling hopper 5 is constituted by a bifurcated chute 13. On the inner surface of the sand-filling hopper 5, a large number of air jets 14 communicating with a compressed air source (not shown) via an on-off valve (not shown) are disposed.

  Low pressure air (e.g., 0.05 to 0.18 MPa) is jetted into the sand filling hopper 5 from a large number of air jets 14 so as to form an aeration for floating and fluidizing the foundry sand S. Further, at the lowermost portion of the chute 13 in the sand-filling hopper 5, a sand-filling port 15 for feeding the casting sand S downward from the chute 13 is provided.

  Sand filling nozzles 16 for sending casting sand S to the lower molding space of the squeeze board 7 are formed on both sides of the plurality of squeeze feet 8 in the squeeze board 7, and the sand filling nozzles 16 communicate with the sand filling port 15. It is done. The sand filling hopper 5 and the squeeze head mechanism 6 mounted at the lower end thereof are moved up and down by a sand filling hopper raising and lowering means (in the present embodiment, a hydraulic cylinder) not shown.

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

  The operation of the device thus configured will be described. FIG. 1 shows a state in which a molding space is formed by the flask 3, the fill frame 4, the squeeze head mechanism 6, and the pattern plate 2. Next, the squeeze foot 8 opposed to the model convex portion 2a formed on the pattern plate 2 is lowered to a predetermined position to be in the state of FIG. As a result, the amount of casting sand S squeezed by the squeeze foot 8 opposed to the model convex portion 2a can be reduced, and a more preferable molding space is formed.

  Next, low-pressure air is jetted from a large number of air jets 14 into the sand filling hopper 5 to perform aeration for floating and fluidizing the casting sand S in the sand filling hopper 5. Low pressure air is supplied to the sand filling hopper 5 from the air supply pipe 12 through the on-off valve 11 while aeration is performed. As shown in FIG. 3, the casting sand S is aerated into the molding space by low pressure air via the sand filling port 15 and the sand filling nozzle 16 as shown in FIG. At this time, low pressure air at the time of aeration filling is exhausted from a not-shown vent hole of the filling frame 4.

  Next, the squeeze foot 8 opposed to the model convex portion 2a is raised to the rising end. As shown in FIG. 4, a space 17 without casting 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 raising / lowering means, and the casting sand S in the molding space is squeezed by the squeeze board 7 and the plurality of squeeze feet 8. Then, at the same time as the start of the squeezing step or during the squeezing step, the squeeze foot 8 opposed to the model recess 2b formed in the pattern plate 2 is lowered to partially cast sand S in the model recess 2b. Squeeze in (see Figure 5). The space section 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 and lowering means to separate the flask 3 in which the mold is formed and the squeeze head mechanism 6 from each other. Further, the squeeze foot 8 opposed to the model recess 2b is raised to the rising end. Further, the filling frame 4 is raised by the filling frame elevating means to separate the flask 3 and the filling frame 4 from each other. Next, the mold is removed by raising the flask by the flask lifting means, and the flask 3 and the pattern plate 2 are separated.

  Next, the flask 3 in which the mold is formed is carried out by the carry-in / out conveyor, and the empty flask 3 is carried in. In addition, the flask 3 in which the mold was shape | molded becomes like 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 lower frame not shown is carried into the apparatus together with the pattern carrier.

  Next, the empty flask 3 is lowered by the flask elevating means and placed on the pattern plate for the lower flask (on the pattern carrier). Next, the filling frame 4 is lowered by the filling frame elevating means and pressed onto the flask 3 and brought into close contact. Further, the sand filling hopper 5 and the squeeze head mechanism 6 are lowered by the sand filling hopper raising and lowering means so that the squeeze head mechanism 6 is inserted into the filling frame 4. As a result, the 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 opposed to the model recess 2b formed in the pattern plate 2 can be changed to a desired pressure. According to this configuration, by setting the operating pressure to a pressure lower than a predetermined (ordinary) pressure, there is an advantage that it is possible to prevent the mold removal failure of the pattern recess 2b.

  If 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, a mold failure may occur in the model recess 2b. In such a case, the working pressure of the squeeze foot 8 is set to a pressure lower than a predetermined pressure (for example, a pressure which is half the predetermined pressure) to reduce the mold-drawing resistance of the mold in the vertical direction of the model recess 2b. As a result, it is possible to prevent die casting defects of the model recess 2 b.

  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, and when the measured squeeze pressure reaches a preset pressure, the pattern plate 2 is formed. The lowering of the squeeze foot 8 opposite to the model recess 2b is started.

  Although the timing of the start of lowering of the squeeze foot 8 facing the model recess 2b depends on the model shape, the casting sand S is difficult to compress if it is too early. On the other hand, if it is too late, the molding sand S is already compressed to a certain extent, so it becomes difficult to compress the casting sand S by the lowering of 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 recess 2b can be started at an appropriate timing. In the present embodiment, the squeeze pressure at which the squeeze head mechanism 6 is lowered to squeeze the foundry sand S is the descent pressure of the sand-filled hopper lifting means for squeezing the squeeze head in the present embodiment.

  In the embodiment of the present invention, the timing for starting the descent 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 descent distance of the squeeze head mechanism 6 for squeezing the foundry sand S is measured, and when the measured descent distance reaches a preset distance, the squeeze facing the model concave portion 2b formed in the pattern plate 2 The descent of the foot 8 may be started.

  Also in this configuration, there is an advantage that the above-mentioned problems can be avoided and the lowering of the squeeze foot 8 facing the model recess 2b can be started at an appropriate timing. In the present embodiment, an encoder (not shown) is attached to the sand-filling hopper 5, and the descent distance of the squeeze head mechanism 6 can be measured by this encoder.

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

  In the embodiment of the present invention, after the casting 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 casting sand S is squeezed. According to this configuration, as shown in FIG. 4, the space 17 without casting sand S can be formed in the molding space, and the amount of casting sand S squeezed on the model convex portion 2a is reduced. Therefore, there is an advantage that the casting sand S on the model recess 2 b is easily compressed when the squeeze foot 8 facing the model recess 2 b is lowered.

  In the present embodiment, as described above, the squeeze head mechanism 6 is lowered to squeeze the casting sand S after the squeeze foot 8 facing the model convex portion 2a is lifted, but the present invention is limited thereto. It is not a thing. For example, the casting sand S may be squeezed by lowering the squeeze head mechanism 6 while raising the squeeze foot 8 facing the model convex portion 2a. This has the advantage that the cycle time of the device can be reduced.

  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 in which a molding space is formed when another pattern carrier 18 is used. The pattern carrier 18 includes a frame-like frame 19 surrounding the outer periphery of the pattern plate 2 and sliding up and down. A plurality of guide pins 20 are connected to the lower portion of the frame-like frame 19, and the guide pins 20 are inserted into the main body frame 21 so as to be vertically slidable. The frame-like frame 19 is raised and lowered by a raising and lowering cylinder (not shown) via a guide pin 20. The upper surface of the frame 19 projects slightly (for example, 30 mm) upward from the parting surface 2c of the pattern plate 2 at the extension end of the elevating cylinder (see FIG. 7), and the parting surface 2c of the pattern plate 2 at the contraction end. And the same plane as

  In the embodiment shown in FIG. 7, the pattern carrier 18 is provided with a frame-like frame 19 which 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-like frame 19. . According to this configuration, when the casting sand S in the molding space is squeezed, the frame-like frame 19 is lowered, so that there is an advantage that the squeezing from the model surface side is performed. Further, by raising the frame-like frame 19, the molded mold is slightly lifted from the stopped state together with the flask 3 and is released from the stopped state, so that there is an advantage that the die-drawing accuracy is high.

  In the embodiment of the present invention, the sand-filled nozzles 16 are formed on both 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 to penetrate the side of the fill frame 4. In this case, the bifurcated chute 13 in the lower part of the sand-filling hopper 5 may be disposed on the outside of the filling frame 4 and fixed to the filling frame 4. The sand filling port 15 provided at the lowermost portion of the chute 13 and the sand filling nozzle 16 formed on the side of the fill frame 4 may be communicated with each other. The squeeze head mechanism 6 may be separately provided with an actuator and moved up and down. 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 when the squeeze is completed to the parting surface 2c of the pattern plate 2 and the lower surface of the squeeze foot 8 facing the model recess 2b. The closer the distance K2 from the surface to the bottom surface of the pattern recess 2b, the more uniform the mold density becomes, which is more preferable.

The main symbols used in the present specification and the drawings are summarized below.
2 pattern plate 2a model convex part 2b model concave part 3 flask 3a upper opening 4 fill frame 4a lower opening 5 sand filling hopper 6 squeeze head mechanism 7 squeeze board 8 squeeze foot 19 frame shaped frame S casting sand

Claims (7)

A mold making method for forming a mold with casting sand using a flask and a pattern plate,
The squeeze board penetrating the squeeze board through the squeeze board through the squeeze board, the squeeze board that can enter and exit from the squeeze board Forming a molding space using a squeeze head mechanism having a plurality of squeeze feet capable of vertical movement, forming the molding space using the pattern plate, and filling the molding sand in the sand-filling hopper storing the casting sand in the molding space And lowering the squeeze head mechanism to squeeze the foundry sand,
At the same time as the start of the squeezing step or in the middle of the squeezing step, the squeeze foot facing the model recess formed in the pattern plate is lowered.
Mold molding method. The operating pressure for lowering the squeeze foot opposed to the pattern recess formed in the pattern plate is characterized in that it can be changed 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 facing the pattern recess formed on the pattern plate It is characterized by starting the descent,
A mold making method according to claim 1 or 2. In the step of squeezing, the descent distance of the squeeze head mechanism for squeezing the foundry sand is measured, and when the measured descent distance reaches a preset distance, it faces the model concave portion formed in the pattern plate Starting the lowering of the squeeze foot,
A mold making method according to claim 1 or 2. In the step of forming the molding space, the step of lowering the squeeze foot opposed to the model convex portion formed in the pattern plate is performed, and then the step of filling is performed.
A mold making method according to claim 1 or 2. After the filling step, the squeezing step is performed after raising or while raising the squeeze foot opposed to the model convex portion formed on the pattern plate,
The mold making method according to claim 5. A frame-shaped frame is provided which surrounds the outer periphery of the pattern plate and slides up and down, and a part of the molding space is formed by the frame-shaped frame.
A mold making method according to claim 1 or 2.

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