JP2020001095A - Kneading method - Google Patents

Abstract

To provide a kneading device that can suppress variation in kinetic viscosity of core paste in a short kneading time.SOLUTION: The kneading device is provided that comprises: a stirrer 3 rotating with a rotating shaft as a center in a kneading space 2a formed in a kneading pot 2, and having a stirring pin 3a extended in parallel to the rotating shaft; and an injection piston 6 filling core paste 7 kneaded in the kneading space 2a into an injection mold adjacent to the kneading pot 2. Rotation of the stirrer 3 before kneading the subsequent core material 8 moves at least part of the core paste 7 remaining in the injection mold side of the kneading space 2a to a charging port 2b side into which the subsequent core material 8 is charged.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a kneading method.

2. Description of the Related Art An apparatus for kneading a core material by rotating a stirrer arranged in a kneading space in a kneading pot is known.
Patent Literature 1 discloses a kneading device including a stirring pin arranged parallel to a rotation axis of a stirrer, and an injection piston that can penetrate the stirring pin and slide in a kneading space toward an injection port. Have been.

JP-A-2006-195990

The inventors have found the following problems with respect to a kneading device.
In the kneading device disclosed in Patent Document 1, the core material is kneaded by rotating a stirrer. The kneaded core material constitutes a core paste. The core paste is filled in the injection mold by sliding the injection piston toward the injection port. The filled core paste solidifies in the injection mold. The solidified core paste constitutes the core. After the core paste is injected into the kneading space, the next core material is charged.

  When the injection piston slides toward the injection port, a part of the core paste may remain on the injection port side of the kneading space. When the injection mold is filled with the core paste, it is heated to a high temperature. The injection port of the kneading space communicates with the cavity of the injection mold. Therefore, the temperature of the injection port side end of the kneading pot becomes high when the injection mold is heated. Therefore, the core paste remaining on the injection port side of the kneading space has a high temperature. When the temperature of the remaining core paste becomes high, the amount of water is reduced by drying.

  The remaining core paste is kneaded with the next core material to form the next core paste. The remaining core paste has a lower moisture content than the next core material. Since a plurality of materials having different amounts of water are kneaded, the kinematic viscosity of the next core paste tends to vary. By sufficiently kneading the remaining core paste and the next core material, variations in the kinematic viscosity of the next core paste can be suppressed. However, it is necessary to increase the kneading time in order to suppress variations in the kinematic viscosity of the core paste.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a kneading apparatus capable of suppressing variation in kinematic viscosity of a core paste in a short kneading time.

  One mode for achieving the above object is that, while rotating about a rotation axis in a kneading space provided in a kneading pot, a stirrer having a stirring pin extending parallel to the rotation axis, and kneading in the kneading space. An injection piston that fills an injection mold adjacent to the kneading pot with the core paste, and before kneading the next core material, by rotating the stirrer, At least a part of the core paste remaining on the injection molding die side of the kneading space is moved to an inlet port for charging the next core material.

  In the kneading apparatus according to the present invention, before kneading the next core material, by rotating the stirrer, at least a portion of the core paste remaining on the injection mold side of the kneading space is The next core material is moved to the charging port side for charging. Therefore, the remaining core paste and the next core material can be uniformly kneaded in a short time. Therefore, the variation in the kinematic viscosity of the core paste can be suppressed in a short kneading time.

  ADVANTAGE OF THE INVENTION According to this invention, the kneading apparatus which can suppress the variation of the kinematic viscosity of a core paste in a short kneading time can be provided.

It is sectional drawing of the kneading apparatus concerning this Embodiment. It is sectional drawing of the kneading apparatus which injected the core paste. It is sectional drawing of a kneading apparatus in which the stirring pin was rotated. It is sectional drawing of the kneading apparatus into which the next core material was injected. 6 is a flowchart illustrating a procedure according to the embodiment.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. In addition, in order to clarify the description, the following description and drawings are simplified as appropriate.

  First, the configuration of the kneading apparatus according to the present embodiment will be described with reference to FIG. The kneading device 1 includes a kneading pot 2, a stirrer 3, a linear actuator 4, and an injection piston 6, as shown in FIG. FIG. 1 also shows the core paste 7. In FIG. 1, a dashed line indicates a rotation axis of the stirrer 3.

  It should be noted that the right-handed xyz rectangular coordinates shown in FIG. 1 and other drawings are for convenience in describing the positional relationship of the components. Usually, the positive direction of the z-axis is vertically upward and the xy plane is the horizontal plane, which is common between the drawings.

  The kneading pot 2 is provided with a kneading space 2a inside. In addition, the kneading pot 2 is provided with an input port 2b and an injection port 2c. The injection port 2c communicates with a cavity of an injection mold (not shown). The core material is charged into the kneading space 2a from the charging port 2b. The charged core material is kneaded in the kneading space 2a. The kneaded core material constitutes the core paste 7. The core paste 7 is injected from the injection port 2c and is filled in the cavity of the injection mold.

  As shown in FIG. 1, a stirrer 3 is disposed in the kneading space 2a. The stirrer 3 can rotate around the rotation axis shown in FIG. The stirrer 3 includes a stirring pin 3a and a rotation base 3b. The rotation base 3b is a disk-shaped member arranged perpendicular to the rotation axis. A drive gear (not shown) is arranged on the periphery of the rotation base 3b. The drive gear is meshed with the edge of the rotation base 3b. The drive gear is connected to a stirrer motor (not shown). When the stirrer motor is driven, the drive gear rotates about the rotation axis of the stirrer 3. With the rotation of the drive gear, the stirrer 3 rotates around the rotation axis.

  The stirring pin 3a extends parallel to the rotation axis from the surface of the rotation base 3b on the side of the injection port 2c. The position where the stirring pin 3a is arranged is not particularly limited as long as it is a surface on the side of the injection port 2c of the rotary base 3b. The stirring pins 3a are, for example, arranged radially around the rotation axis. Further, the stirring pin 3a may be arranged in an S-shape so as to be point-symmetric about the rotation axis of the stirring element 3 as a center point. The shape of the stirring pin 3a is not particularly limited as long as it is a column extending parallel to the rotation axis. The stirring pin 3a has, for example, a circular cross section. Further, the stirring pin 3a may have a rectangular cross section.

  As shown in FIG. 1, a linear actuator 4 is installed at the end of the kneading pot 2 opposite to the injection port 2c. The linear actuator 4 includes a ball nut 4a, a ball screw 4b, and a geared motor 4c. When the geared motor 4c is driven, the ball nut 4a rotates about a rotation axis. A ball screw 4b passes through the center of the ball nut 4a.

  A spiral groove is provided on the side surface of the ball screw 4b. The groove provided in the ball screw 4b is engaged with the ball nut 4a. Therefore, when the ball nut 4a is rotated by the drive of the geared motor 4c, the ball screw 4b can be rotated about the rotation axis. When the ball screw 4b is rotated around the rotation axis, the ball screw 4b advances and retreats parallel to the rotation axis.

  An injection piston 6 is connected to an end of the ball screw 4b on the injection port 2c side. In the example shown in FIG. 1, a rotatable ball screw 4b is connected to the center of the injection piston. That is, the ball screw 4b can allow the rotation of the injection piston 6. The injection piston 6 is always in contact with the inner peripheral surface of the kneading pot 2, in other words, the wall surface of the kneading space 2a. Therefore, the injection piston 6 slides on the wall surface of the kneading space 2a as the ball screw 4b advances and retreats.

  As shown in FIG. 1, the stirring pin 3a penetrates the injection piston 6. Therefore, when the stirrer 3 rotates, the injection piston 6 rotates together with the stirring pin 3a. That is, the injection piston 6 does not hinder the rotation of the stirrer 3. The injection piston 6 can move back and forth in parallel with the rotation axis without being affected by the stirrer 3.

  When kneading the core material in the kneading apparatus 1, first, the injection piston 6 is disposed so as to be located closer to the linear actuator 4 than the inlet 2b. Next, the core material is charged into the kneading space 2a from the charging port 2b. Next, the stirrer 3 is rotated by driving the stirrer motor. The core material put into the kneading space 2 a is kneaded by the rotation of the stirrer 3.

  The kneaded core material constitutes the core paste 7. Core materials are solid materials and liquid materials. The solid material is foundry sand. The foundry sand is, for example, natural sand. The foundry sand may be artificial sand. Liquid materials are solid material binders. The liquid material is, for example, water glass. The core paste 7 may contain an additive in addition to the core material.

  After sufficiently kneading the core paste 7, the injection piston 6 is slid toward the injection port 2c. The core paste 7 is injected from the injection port 2c by sliding of the injection piston 6. The core paste 7 injected from the injection port 2c is filled in the cavity. The core paste 7 filled in the cavity is solidified. The solidified core paste 7 forms a core. The core manufactured by using the kneading apparatus according to the present invention is used, for example, for manufacturing a vehicle-mounted engine component.

  Next, an operation when the next core material is charged into the kneading apparatus according to the present embodiment will be described with reference to FIGS. FIG. 2 is a cross-sectional view of the kneading device into which the core paste has been injected. FIG. 3 is a sectional view of the kneading device in which the stirring pin is rotated. FIG. 4 is a cross-sectional view of the kneading apparatus into which the next core material has been charged. 2 to 4, the core paste 7 and the next core material 8 are also illustrated. 2 to 4 indicate the rotation axis of the stirrer 3.

  The injection piston 6 slides toward the linear actuator 4 after injecting a sufficient amount of the core paste 7. And it is arrange | positioned so that it may be located in the linear actuator 4 side rather than the inlet 2b. As shown in FIG. 2, a part of the core paste 7 remains on the kneading space 2a on the side of the injection port 2c even after the injection is completed.

  When solidifying the core paste 7 filled in the cavity, the injection mold is heated. The injection port 2c is adjacent to the cavity. Therefore, when the injection mold is heated, the temperature of the injection port 2c side of the kneading space 2a becomes high. Therefore, the core paste 7 remaining on the injection port 2c side of the kneading space 2a is dried.

  By rotating the stirrer 3, a part or all of the remaining core paste 7 can be moved to the inlet 2b side of the kneading space 2a as shown in FIG. Further, the remaining core paste 7 can be loosened. When the core paste 7 is moved to the input port 2b side, for example, the stirrer 3 is rotated in a direction opposite to that during kneading.

  In the example shown in FIG. 3, the stirrer 3 is provided with a stirrer pin 3a so that the core paste 7 can be moved toward the rotation axis during kneading. Therefore, the core paste 7 can be moved toward the wall surface of the kneading space 2a by rotating the stirrer 3 in the opposite direction to that during kneading.

  The remaining core paste 7 is kneaded with the next core material 8 shown in FIG. 4 to form the next core paste. The remaining core paste 7 has a smaller amount of water than the next core material 8. Therefore, in order to make the kinematic viscosity of the next core paste uniform, it is necessary to sufficiently knead the remaining core paste 7 and the next core material 8.

  Before the remaining core paste 7 and the next core material 8 are kneaded, the remaining core paste 7 is moved to the inlet 2b side by rotation of the stirrer 3, thereby shortening the time. The kinematic viscosity of the next core paste can be made uniform by kneading. A core paste having a uniform kinematic viscosity is unlikely to cause poor filling. Therefore, the core manufactured by using the kneading apparatus 1 can accurately mold a cooling circuit and the like of the vehicle-mounted engine.

  The movement of the core paste 7 by the rotation of the stirrer 3 is performed, for example, before the next core material 8 is charged. The movement of the core paste 7 by the rotation of the stirrer 3 may be performed after the next core material 8 is charged. Further, the stirrer 3 may be rotated while the next core material 8 is charged.

  The rotation speed of the stirrer 3 when moving the remaining core paste 7 is appropriately determined. For example, when the remaining core paste 7 is moved before the next core material 8 is charged, the stirrer 3 is rotated at a higher speed than when the core paste 7 is kneaded. In addition, when the next core material 8 is charged and the remaining core paste 7 is moved, the stirrer 3 is rotated at a lower speed than when kneading the core paste 7. With the configuration described above, the variation in kinematic viscosity of the core paste can be suppressed in a short kneading time.

  Next, an embodiment of the present invention will be described with reference to FIG. 5 and Tables 1 and 2. FIG. 5 is a flowchart illustrating a procedure according to the embodiment. Table 1 is a table showing a procedure according to the embodiment of the present invention. Table 2 is a table showing the results of measuring the kinematic viscosity of the examples of the present invention.

  In the embodiment of the present invention, as shown in FIG. 1, after the core paste has been injected, the first rotation step (step S1) is performed. When performing the first rotation step (step S1), the stirrer 3 was rotated clockwise at 200 rpm for 2 seconds. By performing the first rotation step (Step S1), the core paste 7 remaining on the injection port 2c side of the kneading space 2a was moved to the input port 2b side of the kneading space 2a.

  Next, a first material charging step (step S2) was performed. In the first material charging step (Step S2), one of a solid material and a liquid material is charged into the kneading space 2a from the charging port 2b. The first material charging step (step S2) was performed in a state where the rotation of the stirrer 3 was stopped or in a state where the stirrer 3 was rotated clockwise at 15 rpm.

  Next, a second rotation step (step S3) was performed. In performing the second rotation step (step S3), the stirrer 3 was rotated clockwise at 200 rpm for 2 seconds. By performing the second rotation step (step S3), the core paste 7 remaining on the injection port 2c side of the kneading space 2a was moved to the input port 2b side of the kneading space 2a.

  Next, a second material charging step (step S4) was performed. In the second material charging step (step S4), of the solid material and the liquid material, the material not charged in the first material charging step (step S2) is charged into the kneading space 2a from the charging port 2b. The second material charging step (step S4) was performed in a state where the rotation of the stirrer 3 was stopped or in a state where the stirrer 3 was rotated clockwise at 15 rpm.

  Next, a kneading step (step S5) was performed. When performing the kneading step (step S5), the stirrer 3 was rotated counterclockwise at 170 rpm. The kneading step (step S5) was performed so that the total rotation time of the stirrer 3 was 44 seconds in total with the first rotation step (step S1) and the second rotation step (step S3).

  In Examples 1 to 5, the first material charging step (Step S2) and the second material charging step (Step S4) were performed under the conditions shown in Table 1. Table 2 shows the results of measuring the kinematic viscosities of Examples 1 to 5. The numerical values shown in Table 2 are “average value ± 3σ”. Changing the order of charging the solid material and the liquid material changed the kinematic viscosity of the next core paste.

  As shown in Table 2, among Examples 1 to 5, when kneading was performed under the conditions of Example 1, the variation in the kinematic viscosity of the next core paste was most suppressed. In particular, when the first rotation step (step S1) is not performed and the second rotation step (step S3) is performed under the conditions of the first embodiment, the variation in the kinematic viscosity of the next core paste is minimized. Could be suppressed.

  According to the invention according to the present embodiment described above, it is possible to provide a kneading apparatus capable of suppressing variation in kinematic viscosity of the core paste in a short kneading time.

  The present invention is not limited to the above embodiment, and can be appropriately changed without departing from the gist. The case where the present invention is applied to the technique of kneading the casting core paste has been described above. However, the present invention can be applied to any technique as long as the material is kneaded in the apparatus. For example, the present invention can be applied to a kneading device for kneading food or a kneading device for kneading concrete.

DESCRIPTION OF SYMBOLS 1 Kneading apparatus 2 Kneading pot 2a Kneading space 2b Input port 2c Injection port 3 Stirrer 3a Stirring pin 3b Rotary base 4 Linear actuator 4a Ball nut 4b Ball screw 4c Geared motor 6 Injection piston 7 Core paste 8 Next core material

Claims (3)

In a kneading space provided in the kneading pot, while rotating around a rotation axis parallel to the horizontal direction, and a stirrer having a stirring pin extending parallel to the rotation axis,
An injection port provided at one end of the kneading space in the extending direction of the stirrer,
An injection piston for filling a core paste in which a core material is kneaded by the stirrer into an injection mold from the injection port,
In the kneading space is provided on the other end side in the extending direction of the stirrer than the injection port, an input port for charging the core material into the kneading space,
A method for kneading the core material using a kneading device comprising:
After filling the core paste into the injection mold, before kneading the next core material, rotate the stirrer in a state where the rotation axis is parallel to the horizontal direction, the kneading space of the Move at least a part of the core paste remaining on the injection port side to the input port side,
Kneading method. After charging one of the solid material and the liquid material of the next core material from the charging port, by rotating the stirrer, at least a part of the remaining core paste is removed from the charging port side. Move to
Thereafter, of the next core material, the other of the solid material and the liquid material is charged from the charging port, and the next core material is kneaded.
The kneading method according to claim 1. After charging the solid material of the next core material from the charging port, by rotating the stirrer, at least a portion of the remaining core paste is moved to the charging port side,
Thereafter, the liquid material of the next core material is charged from the input port, and the next core material is kneaded,
The kneading method according to claim 2.

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