JP2010012487A - Molding mold and molding method - Google Patents

Abstract

The present invention provides a molding die and a molding method capable of easily molding a molded product having a predetermined shape with a simple configuration without causing shrinkage.
A molding die according to the present invention forms a cavity 1 for solidifying a material filled therein in a flowable state to form a molded product having a predetermined shape, and is formed at a predetermined position. A partial pressurizing means 2 is provided which is slidably provided and pressurizes a relatively thick part of the cavity 1, and this partial pressurizing means 2 is slidably provided inside the cavity 1. Are provided with a pressure pin 3 that partially pressurizes a predetermined position of the material filled in and an electromagnetic induction heating coil 4 that controls the solidification of the portion pressed by the pressure pin 3 of the material.
[Selection] Figure 2

Description

  The present invention relates to a mold and a molding method, and more particularly, to a mold for forming a cavity for solidifying a material filled therein in a flowable state to form a molded product having a predetermined shape, and to the mold The present invention relates to a method of solidifying a material filled in a flowable state inside a formed cavity to mold a molded product having a predetermined shape (molding a molded product with a molding die is called molding).

  In general, in a metal casting method or a resin molding method, the mold cooling rate is increased in the process of forming a molded product of a predetermined shape by filling the mold cavity with a material that is in a liquid flowable state. It is larger (faster) to shorten the solidification time, that is, the time required for molding.

  As shown in FIG. 15, the mold in the gravity casting method generally includes an upper mold 10 ′ and a lower mold 11 ′, and a pouring gate 14 ′ for pouring a molten material as a material, and a bottom 14a of the pouring gate 14 ′. 'Runner 14b' communicating with ', gate 15' located between runner 14b 'and cavity 1', and material provided at a predetermined position for replenishing the amount of shrinkage in the process of melting Z And a reservoir 17 '. The material reservoir 17 'is generally called a feeder in the casting method, and is formed with a relatively large thickness so that the cooling rate becomes slow. In general molds, the gate 15 ′ is often arranged at the end of the cavity 1 ′ (that is, the end of the product shape).

  By the way, particularly when a casting aluminum alloy is molded as a material, the strength of the molded product is strongly influenced by the solidification rate. For this reason, when it is necessary to form a high-strength product by the gravity casting method, generally, the mold is divided into a plurality of parts, each of which is configured to be temperature controllable. In this case, a coating agent (coating agent) for preventing the permeation of the molten metal is applied to the divided molds, and the divided molds are combined to form a cavity, and each is kept at a predetermined temperature. The cavity is filled with a material (molten metal) that is controlled and heated to become liquid and flowable. Thereafter, the mold is cooled to increase the solidification rate, the material is solidified in a short time, and the mold is opened to take out a product having a predetermined shape.

  Here, the material filled in the cavity in a liquid state that can be flowed by heating has a low cooling rate in the thick part of the product, so the thin part It solidifies after a delay.

  On the other hand, when the flowable material solidifies, the volume shrinks in the cavity. If the material corresponding to the contracted volume is not replenished, shrinkage cavities due to bubbles or the like are generated.

  For this reason, as a countermeasure to prevent the occurrence of shrinkage cavities due to bubbles, etc., the mold is generally designed to increase the cooling rate of the part far from the gate and delay the cooling rate near the gate, thereby solidifying the material far from the gate. Starting from the part, the material is sequentially supplied from the gate side with respect to the volume shrinkage due to the solidification, and the directional solidification is performed in which the solidification completion position is sequentially moved toward the gate.

  However, when it is necessary to form a thick part in the part away from the gate due to the shape of the product, etc., the cooling rate of the thick part is slow and the surrounding part is fast. The thick part is closed when the surrounding thin part solidifies, making it difficult to supply molten metal to the thick part, and shrinkage cavities tend to occur.

  As one of the countermeasures, a cavity is formed so that the thickness gradually increases from the surrounding portion where the cooling rate is high toward the thick portion (hereinafter referred to as gradual change in thickness). Yes.

  As another countermeasure, a method of increasing the temperature of the mold and delaying the solidification of a thin portion having a high cooling rate has been adopted. In this case, as shown in FIG. 15, the cooling rate of the thick portion such as the feeder 17 ′ is further slowed down (that is, the solidification is further slowed down). Cooling insert 20 'was provided and cooling was performed.

  Furthermore, as disclosed in Patent Document 1 and the like, it is known to partially pressurize a material using a pressure pin. Furthermore, as disclosed in Patent Document 2, it is known to heat a feeder with an induction heating coil and hold it in a molten state.

JP-A-6-122061 Japanese Patent Laid-Open No. 11-33703

  Of the above-mentioned conventional techniques, when the cavity is formed by gradually changing the thickness, the molded product is thickened to an unnecessary part, and the material is wasted and melted so that the material can flow. Therefore, there is a problem that the energy required for the increase increases and the weight of the molded product increases.

  Moreover, in the case where the temperature of the mold is increased among the conventional techniques described above, from the problem that a large amount of energy is required to heat the mold, and from delaying the solidification of the material, There is a problem that it takes time to complete the molding and take out the molded product. As a countermeasure, as shown in FIG. 15, in the case where the cooling insert 20 ′ is provided in a thick portion such as the feeder 17 ′, the structure of the mold becomes complicated and the size is increased. The problem is that the shape and size of the molded product are limited, and the molding die is partially cooled by the cooling insert 20 ', resulting in a temperature difference, causing warping or distortion deformation, resulting in reduced molding accuracy. There was a problem such as.

  On the other hand, in the above-mentioned conventional technique, in Patent Document 1, the material filled in the cavity of the mold in a state in which it can flow in a liquid state starts to solidify from the part in contact with both sides of the cavity, and then the solid phase. However, the inside does not start coagulation and remains in a liquid phase, or a solid phase and a liquid phase are mixed. When the material is pressed with a pressure pin in this state, there is a problem that the structure of the material is destroyed and a molded product having a required strength cannot be formed. In particular, in the casting method, a core (sand mold) molded from casting sand is used as a part of the molding die so that it can be collapsed after molding is completed and the hollow part can be easily molded into a molded product. However, Patent Document 1 has a problem that a sand mold cannot be used because a strong force is applied to the mold when pressed. Further, in Patent Document 1, the material filled in the cavity of the molding die in a state where it can flow in a liquid state is baked on or stuck to the pressure pin. Therefore, since a large force is required to separate the pressure pin from the molded product, the driving means such as a cylinder for driving the pressure pin is enlarged, and the shape of the molded product that can be applied is limited. There is a problem that the molded product may be galling and scratched when separated.

  Of the above-described conventional techniques, in Patent Document 2, when the hot water is heated by an induction heating coil and held in a molten state, it takes time for the material of the hot water to solidify. For this reason, the efficiency of the molding cycle time cannot be improved, and when the paramagnetic material is heated by electromagnetic induction heating, its energy efficiency is about 80%, for example, and the remaining 20% is electromagnetic induction. Since the temperature rises due to resistance heating loss of the heating coil, there is a problem that it is necessary to cool the electromagnetic induction heating coil.

  The present invention has been made in view of the above-described problems, and provides a molding die and a molding method capable of easily molding a molded product having a predetermined shape with a simple configuration without causing shrinkage cavities. Objective.

In order to achieve the above object, the invention related to a mold is a mold that forms a cavity for solidifying a material filled inside in a flowable state to form a molded product having a predetermined shape. A pressure pin that is slidably provided at a position and partially pressurizes a predetermined position of the material filled in the cavity, and controls solidification of a portion of the material that is pressed by the pressure pin An electromagnetic induction heating coil is provided.
The invention relating to the molding method is a method of solidifying a material filled in a flowable state inside a cavity formed in a mold, and molding a molded product of a predetermined shape, and filling the inside of the cavity An electromagnetic induction heating coil for slidably providing a pressurizing pin for partially pressurizing a predetermined position of the formed material at a predetermined position and for controlling solidification of a portion of the material pressed by the pressurizing pin A state in which the solidification of the material filled in the cavity is controlled by the electromagnetic induction heating coil so as to delay the solidification of the portion pressurized by the pressure pin from the surrounding solidification. The pressure is applied by the pressure pin.

According to the invention relating to the mold, only a predetermined position of the material filled in the cavity is heated by the electromagnetic induction heating coil or given at least one of vibrations, so that In a state where coagulation is appropriately controlled, pressure is applied by a pressure pin provided so as to be slidable. Therefore, the material that shrinks in volume in the process of filling and solidifying inside the cavity in a flowable state can be filled and replenished with a little energy efficiently and appropriately, so it can solidify without generating shrinkage. And can be molded into a molded product having a predetermined shape.
According to the invention relating to the molding method, a pressurizing pin that partially pressurizes a predetermined position of the material filled in the cavity is slidably provided at a predetermined position of the mold, and the addition of the material is performed. An electromagnetic induction heating coil for controlling the solidification of the portion pressed by the pressure pin is provided, and then the material is filled in the cavity, and the solidification only at a predetermined position of the material is partially performed by the electromagnetic induction heating coil. By pressurizing with a pressure pin in a state controlled to be delayed from the surrounding solidification, the shrinkage accompanying solidification only at a predetermined position of the material can be appropriately and sufficiently filled and replenished with little energy. Therefore, a molded product having a predetermined shape can be formed without generating a shrinkage nest.

(Aspect of the Invention)
In the following, the invention that is claimed to be claimable in the present application (hereinafter referred to as “claimable invention”. The claimable invention is at least the “present invention” to the invention described in the claims. Some aspects of the present invention, including subordinate concept inventions of the present invention, superordinate concepts of the present invention, or inventions of different concepts) will be illustrated and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combinations of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention. In each of the following terms, (1) corresponds to claim 1, (2) corresponds to claim 2, (3) corresponds to claim 3, and (4) claims. The item (5) corresponds to the item (5), the item (6) corresponds to the item (6), the item (7) corresponds to the item (7), and the item (8) corresponds to the item (8). (9) corresponds to claim 9, (12) corresponds to claim 10, (13) corresponds to claim 11, and (14) corresponds to claim 12. (15) corresponds to claim 13.

(1) A mold for forming a cavity for solidifying a material filled inside in a flowable state to form a molded product having a predetermined shape,
A pressure pin that is slidably provided at a predetermined position and partially pressurizes the predetermined position of the material filled in the cavity;
An electromagnetic induction heating coil for controlling solidification of a portion of the material pressed by the pressing pin.

  In the invention of the item (1), only a predetermined position of the material filled in the cavity is heated by an electromagnetic induction heating coil or given at least one of vibrations, thereby solidifying the portion. In a state in which is properly controlled, pressure is applied by a pressure pin that is slidably provided. Therefore, the material that shrinks in volume in the process of filling and solidifying inside the cavity in a flowable state can be filled and replenished with a little energy efficiently and appropriately, so it can solidify without generating shrinkage. And can be molded into a molded product having a predetermined shape. In addition, since a strong force is not applied to the mold, a sand mold can be used for the core.

  (2) A material to be heated, which is made of a ferromagnetic material and is heated by the electromagnetic induction heating coil, is disposed in a portion of the cavity that is in contact with a portion pressed by a pressure pin of the material. The mold according to (1).

  In the invention of item (2), in the invention described in item (1), a material to be heated which is made of a ferromagnetic material and is heated by the electromagnetic induction heating coil at a portion in contact with a portion pressed by the pressure pin of the material. By providing at least one of heating the member to be heated or applying vibration by the electromagnetic induction heating coil, the solidification of the material is partially controlled to an appropriate state, Such a portion can be pressurized by a pressure pin.

  (3) The mold according to the item (2), wherein a portion around the material to be heated passes by a magnetic line generated by the electromagnetic induction heating coil is made of a soft magnetic material.

  In the invention of the item (3), in the invention described in the item (2), a portion through which the magnetic lines of force generated by the electromagnetic induction heating coil around the material to be heated, such as the shaft portion of the pressure pin and the periphery thereof, passes through the soft magnetic material. In this way, the solidification of the material can be achieved by heating only a predetermined position of the material filled in the cavity with a little energy by the electromagnetic induction heating coil or applying vibration. It can be controlled appropriately.

  (4) The mold according to (2) or (3), wherein the periphery of the material to be heated has an insulating laminated metal structure that prevents heating by the electromagnetic induction heating coil.

  In the invention described in item (4), in the invention described in any one of items (2) or (3), an insulating laminated metal structure for preventing heating by the electromagnetic induction heating coil around the material to be heated; As a result, unnecessary parts are not heated unnecessarily, and there is no need to cool the surrounding parts, and only a predetermined position of the material filled in the cavity is heated by electromagnetic induction heating with little energy. By at least one of heating by the coil or applying vibration, the solidification of the material can be appropriately controlled.

  (5) The mold according to any one of (2) to (4), wherein the periphery of the material to be heated in the cavity is configured by a heat insulating layer that maintains the temperature of the material.

  In the invention of the item (5), in the invention described in any one of the items (2) to (4), the periphery of the heated material in the cavity is constituted by a heat insulating layer that maintains the temperature of the material. The temperature of the material around the heated material can be maintained.

  (6) Any one of the items (1) to (5), further comprising pressure control means for detecting the pressure of the material pressed by the pressing pin and controlling the pressure. The mold according to one item.

  In the invention of item (6), in the invention described in any one of items (1) to (5), the pressure control means detects the pressure of the material to be pressurized by the pressure pin, and pressurizes. Since the pressing force of the pin can be controlled, the material can be appropriately pressurized.

  (7) The material to be heated is made of a ferromagnetic material having a predetermined Curie point, and further includes temperature control means for measuring the impedance of the electromagnetic induction heating coil to control the heating temperature of the material. The mold according to any one of items (2) to (6), wherein

  In the invention described in item (7), in the invention described in any one of items (2) to (6), the material to be heated is constituted by a ferromagnetic material having a predetermined Curie point, and temperature control means By measuring the impedance of the electromagnetic induction heating coil, the heating temperature of the material can be controlled appropriately and easily, and thus the solidification of the material can be controlled appropriately and easily.

  (8) Any one of the items (1) to (7), further comprising a coating agent application unit that applies a coating agent for preventing the material from sticking to the portion sliding with the pressure pin. The mold according to one item.

  In the invention of item (8), in the invention described in any one of items (1) to (7), the coating agent is applied between the pressure pin and the sliding portion by the coating agent application means. Thus, it is possible to prevent the material from flowing in between the pressurizing pin and the sliding portion and fixing the material.

(9) The portion sliding with the pressure pin is constituted by a sleeve,
The material of the pressure pin and the sleeve is selected such that the distance between the outer peripheral surface of the pressure pin and the inner peripheral surface of the sleeve is reduced as the temperature rises (1) to (8) A forming die given in any 1 paragraph.

  In the invention of item (9), in the invention described in any one of items (1) to (8), the portion that slides with the pressure pin is constituted by a sleeve, and the material of the pressure pin and the sleeve is changed to a temperature. As the distance between the outer peripheral surface of the pressure pin and the inner peripheral surface of the sleeve is reduced, the temperature before the start of molding increases in the distance between the pressure pin and the sleeve. The coating agent can be applied easily, for example, and the material can be prevented from flowing in when the temperature during molding is increased.

  (10) The outer peripheral surface of the sleeve and the inner peripheral surface of the hole that holds the sleeve are formed into a tapered shape that gradually decreases in diameter in a direction in which the pressure pin pressurizes the material ( The mold according to item 9).

  In the invention of the item (10), in the invention of the item (9), the outer peripheral surface of the sleeve and the inner peripheral surface of the hole holding the sleeve are gradually moved in the direction in which the pressure pin pressurizes the material. Even if the sleeve shrinks in the radial direction due to heat, the inner peripheral surface of the hole and the outer peripheral surface of the sleeve are in close contact with each other, so that the material enters between the two. Thus, the expansion of the sleeve in the radial direction is not hindered.

  (11) It is made of a material that has at least heat resistance and can be elastically deformed, and a seal member that prevents the material from entering is provided in a portion that slides with the pressure pin (1) The shaping | molding die as described in any one of-(10) term.

  In the invention described in item (11), in the invention described in any one of items (1) to (10), a seal member made of a material that has at least heat resistance and can be elastically deformed is provided. Thus, it is possible to reliably prevent the material from entering and fixing between the heating pin and the portion where the pressure pin slides.

(12) A method of molding a molded product of a predetermined shape by solidifying a material filled in a flowable state inside a cavity formed in a mold,
A pressure pin that partially pressurizes a predetermined position of the material filled in the cavity is slidably provided at a predetermined position, and solidification of a portion of the material that is pressed by the pressure pin is controlled. Provide an electromagnetic induction heating coil to
In the state in which the solidification of the material filled in the cavity is controlled by the electromagnetic induction heating coil so as to delay the solidification of the portion pressurized by the pressure pin from the surrounding solidification. A molding method characterized by pressurizing with a pressure pin.

  In the invention described in the item (12), the pressure pin is slidably disposed in advance in a predetermined position in the cavity of the mold, and the solidification of the portion pressed by the pressure pin of the material is controlled. An electromagnetic induction heating coil is provided. Thereafter, the cavity is filled with the material, and only a predetermined position of the material filled in the cavity is heated by an electromagnetic induction heating coil, or at least one of applying vibration is performed, and the portion The pressure is applied by sliding the pressure pin in a state where the solidification of the material is appropriately controlled. Therefore, the material that shrinks in volume in the process of filling and solidifying inside the cavity in a flowable state can be filled and replenished with a little energy efficiently and appropriately, so it can solidify without generating shrinkage. And can be molded into a molded product having a predetermined shape. Further, since a strong force is not applied to the mold, the present invention can be applied to a mold using a sand mold for the core.

  (13) The molding method according to (12), wherein the pressure of the material pressed by the pressure pin is detected and the pressure is controlled.

  In the invention of item (13), in the invention described in item (12), the pressure of the material pressed by the pressure pin is detected, and the pressure is controlled to thereby apply the material at an appropriate pressure. Can be pressed.

(14) A material to be heated, which is made of a ferromagnetic material having a predetermined Curie point and is heated by the electromagnetic induction heating coil, is disposed at a portion of the cavity that is in contact with a portion pressed by the pressure pin of the material. ,
The molding method according to (12) or (13), wherein the impedance of the electromagnetic induction heating coil is measured to control the heating temperature of the material.

  In the invention of item (14), in the invention described in item (12) or (13), a ferromagnetic material having a predetermined Curie point at a portion of the cavity that is in contact with the portion pressed by the pressure pin of the material By arranging the material to be heated and measuring the impedance of the electromagnetic induction heating coil, the heating temperature of the material can be controlled appropriately and easily, and thus the solidification of the material can be controlled appropriately and easily Can do.

  (15) The molding method according to any one of (12) to (14), wherein a coating agent for preventing the material from sticking is applied to a portion sliding with the pressure pin.

  In the invention of item (15), in the invention described in any one of items (12) to (14), a coating agent is applied to a portion that slides with the pressure pin, thereby sliding the pressure pin. It is possible to prevent the material from flowing in between the portions and fixing the material.

First, an embodiment of a mold according to the present invention will be described with reference to the drawings in the case of a mold for gravity casting (including a tilting type). In the following description, the same reference numerals denote the same or corresponding parts.
The mold according to the present invention generally forms a cavity 1 for solidifying a material Z filled therein in a flowable state to form a molded product having a predetermined shape. A partial pressurizing means 2 for pressurizing a thick part is provided, and this partial pressurizing means 2 is provided so as to be slidably provided at a predetermined position of the material Z filled in the cavity 1. The pressure pin 3 for pressurizing automatically and the electromagnetic induction heating coil 4 for controlling the solidification of the portion pressed by the pressure pin 3 of the material Z are provided.

In the mold according to the present invention, the material to be heated 5 which is made of a ferromagnetic material and is heated by the electromagnetic induction heating coil 4 at the portion of the cavity 1 which is in contact with the portion pressed by the pressure pin 3 of the material Z. , 6 are arranged. In addition, the portion around the materials to be heated 5 and 6 through which the magnetic lines of force M generated by the electromagnetic induction heating coil 4 pass (which will be described later, reference numerals 30, 31) is made of a soft magnetic material. The surroundings of the materials to be heated 5 and 6 (which will be described later, reference numerals 30, 31, and 7) have an insulating laminated metal structure that prevents heating by the electromagnetic induction heating coil 4. The periphery 7 of the heated materials 5 and 6 in the cavity 1 is constituted by a heat insulating layer that maintains the temperature of the material Z.
Further, the molding die of the present invention includes pressure control means 8 for detecting the pressure of the material Z pressed by the pressing pin 3 and controlling the pressure. Further, the materials to be heated 5 and 6 are made of a ferromagnetic material having a predetermined Curie point, and temperature control means for measuring the impedance of the electromagnetic induction heating coil 4 to control the heating temperature of the material Z; A coating agent applying means 9 for applying a coating agent for preventing the material Z from adhering to a portion that slides with the pressure pin 3 (which will be described later, which is denoted by 6) is provided.
Furthermore, a portion that slides with the pressure pin 3 is constituted by a sleeve (which will be described later, which is denoted by 6), and the material of the pressure pin 3 and the sleeve 6 is that of the pressure pin 3 due to a rise in temperature. The thing which becomes the relationship which the space | interval between the outer peripheral surface 35 and the inner peripheral surface 65 of the sleeve 6 reduces is selected.

  As shown in FIG. 1, the molding die in this embodiment is composed of an upper die 10 and a lower die 11 that can be opened and closed, and are attached to an upper die base 12 and a lower die base 13, respectively. . By abutting the upper mold 10 and the lower mold 11, the cavity 1 having a shape corresponding to the molded product is formed inside. The mold is provided with a gate 14 for pouring a flowable material Z (hereinafter also referred to as molten metal in some cases), and a gate 15 that communicates the bottom 14 a of the gate 14 and the cavity 1. . In the embodiment shown in FIG. 1, a relatively thick portion 1A is formed at the center lower end portion of the cavity 1 and the upper end portion near the gate 15, and the wall thickness is relatively thin between them. Part 1B is formed. Corresponding to the relatively thick portion 1A of the cavity 1, a partial pressurizing means 2 is provided.

  The pressure pin 3 in this embodiment includes a pin main body 30, a support plate 31 that supports the base end portion of the pin main body 30, and a pressure member provided on the distal end surface of the pin main body 30 (described in detail later). However, the code is 5). The pin body 30 and the support plate 31 are made of an insulated laminated metal structure as a soft magnetic material, more specifically, a laminated silicon steel plate whose surface is insulated. As the soft magnetic material, a ferrite powder may be solidified into a predetermined shape. The pin body 30 is supported by the driving means 32 via the support plate 31 and is moved in the axial direction of the pin body 30. As the driving means 32, for example, a cylinder that expands and contracts by a working fluid such as air or oil can be used. A fixed frame 16 is attached to the molding die by a fixing bolt 17, and a driving means 32 is attached to the fixed frame 16 by a fixing bolt 33.

  The electromagnetic induction heating coil 4 is disposed on the support plate 31 so as to surround the proximal end portion of the pin body 30. The electromagnetic induction heating coil 4 heats by generating an eddy current by magnetic lines of force M generated by energization, and is configured so that the applied current can be adjusted to an arbitrary output and frequency. In particular, the eddy current can be adjusted to an arbitrary penetration depth by making the frequency of the applied current variable. The electromagnetic induction heating coil 4 generates vibration by applying a current having a specific frequency. By applying this vibration to the molten metal Z, the binding of the molecules of the molten metal Z when solidified is inhibited, and the solidification is delayed.

  A temperature control means is connected to the electromagnetic induction heating coil 4. The temperature control means includes means for measuring the impedance of the electromagnetic induction heating coil 4, and the temperature at which the molten metal Z is partially heated by adjusting the output and frequency of the current applied from the measurement result of the impedance. And is configured to control vibration to be applied.

  A heat insulating layer 7 made of, for example, ceramic is provided at a position where the partial pressurizing means 2 of the mold is provided. A sleeve 6 is supported on the heat insulating layer 7, and the sleeve 6 is pressurized. A pin body 30 having a pressure member 5 for the pin 3 is slidably inserted. That is, the portion that slides with the pressure pin 3 is constituted by the sleeve 6, and the periphery of the pressure member 5 of the pin body 30 and the sleeve 6 in the cavity 1 is constituted by the heat insulating layer 7. The sleeve 6 in this embodiment is formed in a cylindrical shape having a substantially uniform thickness over the entire length.

  The pressure member 5 provided on the distal end surface of the pin main body 30 of the pressure pin 3 and the sleeve 6 into which the pin main body 30 is inserted are in contact with the portion to be pressurized of the molten metal Z, that is, a ferromagnetic material. The to-be-heated material which consists of and is heated by the electromagnetic induction heating coil 4 is comprised. The ferromagnetic material constituting the pressure member 5 and the sleeve 6 of the pin body 30 is selected from materials having a characteristic of magnetic transition to a paramagnetic state at a predetermined temperature (Curie point). For example, a low carbon steel or a low carbon alloy can be used in the same manner as the metal constituting the main part of the mold.

  Here, when the electromagnetic induction heating coil 4 is energized, the lines of magnetic force M are generated as shown in FIGS. The pin main body 30 and the support plate 31 of the pressure pin 3 serving as a portion through which the magnetic lines of force M pass have an insulated laminated metal structure, which is a soft magnetic material, and thereby has a high magnetic permeability. A magnetic field can be guided to the pressure member 5 and the sleeve 6 of the pressure pin 3 constituting the above, and only the heated materials 5 and 6 can be selectively heated or given vibration. Therefore, there is little energy loss, and the pressurizing member 5 and the sleeve 6 are efficiently heated with a small amount of energy or are given vibrations. Therefore, as shown in FIG. It is possible to efficiently control the coagulation of only the portion in contact with 6 and the pressure member 5. In addition, the part which comprises the cavity 1 surface of a shaping | molding die, Comprising: The part which is not preferable to be heated with the electromagnetic induction heating coil 4 can also be set as the laminated metal structure insulated as mentioned above.

  The pressure control means 8 includes a pressure sensor 80. The pressure sensor 80 can be provided at an appropriate location such as the pressure member 5 on the tip surface of the pressure pin 3 or the surface of the cavity 1 facing the pressure pin 3. In this embodiment, since the molten metal Z is a conductive metal, the pressure sensor 80 includes a conductive material 83 carried in a hole 82 formed in the insulating material 81 as shown in FIG. A power source for supplying a current between the periphery of the insulating material 81 (that is, the pressure member 5 on the front end surface of the pressure pin 3 or the cavity 1 surface facing the pressure pin 3) and the conductive material 83. 84 and a relay coil 85 that opens and closes a circuit connected to the power source 84. The size (diameter) R of the cross section of the hole 82 that accommodates the conductive material 83 of the insulating material 81 is set according to the viscosity of the molten metal Z to be used, the pressure applied by the pressure pin 3, and the like.

  In the pressure sensor configured as described above, the molten metal Z is partially pressurized with the pressure P1 which is equal to or higher than the predetermined pressure P1 by the pressurizing pin 3, so that the molten metal Z is formed in the hole 82 having the predetermined size R. The molten metal Z energizes between the periphery of the insulating material 81 and the conductive material 83. By detecting this energization, it is determined that the molten metal Z has been pressurized by the pressure pin 3 with a pressure P1 that is greater than or equal to a predetermined value, and this determination can be used for controlling the driving means 32 of the pressure pin 3. (This control will be described later). The present invention is not limited to this embodiment, and other types of pressure sensors such as strain gauges can be used.

  As shown in FIGS. 2 and 4, the coating agent applying means 9 includes a nozzle 90 that discharges the coating agent to the side peripheral surface of the heating pin 3, and a conduit 91 that supplies the coating agent to the nozzle 90. Yes. The pipe 91 is connected to a pumping means for pumping the liquid or powder coating agent stored in the tank at a predetermined pressure so as to be discharged from the nozzle 90. A ring-shaped holding member 92 is provided on an end surface of the sleeve 6 opposite to the cavity 1, and a plurality of nozzles 90 are held by the holding member 92. They are connected by a branch pipe 93. As described above, the sleeve 6 expands when heated by the electromagnetic induction heating coil 4, and as shown in FIG. 7B, between the inner peripheral surface and the outer peripheral surface of the pressure pin 3. As shown in FIG. 7C, the gap G1 is generated. In the process of pressurizing the molten metal Z by moving the pressure pin 3 when the molten metal Z is filled from the retracted state, By discharging the coating agent from the nozzle 90, the coating agent closes the gap G1 between the inner peripheral surface of the sleeve 6 and the outer peripheral surface of the pressure pin 3, so that the molten metal Z does not enter the gap G1. Therefore, the molten metal Z can be prevented from adhering between the inner peripheral surface of the sleeve 6 and the outer peripheral surface of the pressure pin 3.

  Furthermore, a sealing material 94 for preventing the intrusion of the molten metal Z and the leakage of the coating agent is held on the inner peripheral surface of the holding member 92 on the opposite side of the cavity 90 from the nozzle 90 (downward in FIG. 4). Has been. Although the seal member 94 having a lip is shown in FIG. 4, other suitable types may be employed. The sealing material 94 can be made of a material that has heat resistance and can be elastically deformed, such as rubber metal (registered trademark). As shown in FIG. 1, the partial pressurizing means 2 is not only provided on the lower mold 11, but is also provided on the upper mold 10 as necessary. Any place that needs to be partially pressurized depending on the thickness of the molded product or the like may be used, and the present invention is not limited to this embodiment.

  Next, another embodiment of the present invention will be described with reference to FIG. In this embodiment, parts that are the same as or correspond to those in the above-described embodiment are given the same reference numerals and omitted, and only different parts will be described. In the above-described embodiment, the sleeve 6 is formed in a cylindrical shape having a substantially uniform thickness over the entire length thereof. However, in this embodiment, the outer peripheral surface 60 of the sleeve 6 is made of the material A of the pressure pin 3. The sleeve 6 is formed in a tapered shape (conical shape) that gradually decreases in the pressing direction, that is, the thickness of the sleeve 6 gradually decreases in the pressing direction of the material Z of the pressing pin 3. Further, the inner peripheral surface of the hole 70 of the heat insulating layer 7 carrying the sleeve 6 corresponds to the outer peripheral surface 60 of the sleeve 6, and the taper gradually decreases in diameter in the direction in which the material of the pressure pin 3 is pressed. (Conical shape). The sleeve 6 is supported so as to be able to move in the axial direction in the hole 70 of the heat insulating layer 7 in accordance with a change in diameter due to thermal expansion.

  In the mold configured as described above, when the sleeve 6 is heated by the electromagnetic induction heating coil 4 or is not vibrated, the outer peripheral surface 35 of the pressure pin 3 is shown in FIG. There is only a slight gap between the sleeve and the inner peripheral surface 65 of the sleeve 6. Thereafter, when the sleeve 6 is heated by the electromagnetic induction heating coil 4, as shown in FIG. 7B, the sleeve 6 is thermally expanded, and the outer peripheral surface 35 of the pressure pin 3 and the inner peripheral surface 65 of the sleeve 6 are A gap G1 is generated between them, but the outer peripheral surface 60 of the sleeve 6 and the inner peripheral surface of the hole 70 of the heat insulating layer 7 are formed in a tapered shape so that no gap is generated. Then, as shown in FIG. 7C, the outer peripheral surface 35 of the pressurizing pin 3 and the inner peripheral surface 65 of the sleeve 6 are applied by the coating agent discharged from the nozzle 90 in the process of moving forward from the state in which the pressurizing pin 3 is retracted. Therefore, the molten metal Z does not enter the gap G1, and therefore, the molten metal is interposed between the inner peripheral surface 65 of the sleeve 6 and the outer peripheral surface 35 of the pressure pin 3. It is possible to prevent Z from adhering and causing scratches and the like. When the pressurizing pin 3 is moved forward, as shown in FIG. 7 (d), since the molten Z is in a state suitable for being pressurized, that is, the molten Z is in the middle of solidification, electromagnetic induction is performed. Since the heating of the sleeve 6 by the heating coil 4 or the application of vibration is stopped, and the sleeve 6 starts to contract, the coating agent previously applied is scraped by the pressure pin 3.

  Next, still another embodiment of the present invention will be described with reference to FIG. In this embodiment, parts that are the same as or correspond to those in the above-described embodiment are given the same reference numerals and omitted, and only different parts will be described. In the above-described embodiment, the sleeve 6 is simply made of a ferromagnetic material and is a material that expands when heated by the electromagnetic induction heating coil 4, whereas the sleeve 6 in this embodiment is A material (referred to as an invar alloy) having a property of shrinking when the temperature rises is used. When the temperature is not increased, a relatively large gap G2 is formed between the inner peripheral surface 65 of the sleeve 6 and the outer peripheral surface 35 of the pressure pin 3 as shown in FIG. 6 is heated by the electromagnetic induction heating coil 4 and contracts when the temperature rises, and the gap G2 between the inner peripheral surface 65 of the sleeve 6 and the outer peripheral surface 35 of the pressure pin 3 is reduced. The diameters of both 65 and 35 are set so as to allow a sliding with advance and retreat movements.

  In the mold configured as described above, as shown in FIG. 8A, a relatively large gap G2 is generated between the outer peripheral surface 35 of the pressure pin 3 and the inner peripheral surface 65 of the sleeve. Then, when the sleeve 6 is heated by the electromagnetic induction heating coil 4, as shown in FIG. 8B, the sleeve 6 contracts as the temperature rises, and the outer peripheral surface 35 of the pressure pin 3 and the inner periphery of the sleeve 6 are contracted. The gap G2 between the surface 65 is reduced. Therefore, it is possible to prevent the molten metal Z filled in the cavity 1 from entering the gap G2. When the pressurizing pin 3 is advanced as shown in FIG. 8D from the state in which the pressurizing pin 3 is retracted as shown in FIG. 8C, the molten metal Z is pressurized. Since Z is in a state suitable for being pressurized, that is, while the molten metal Z is in the middle of solidification, heating of the sleeve 6 or application of vibration by the electromagnetic induction heating coil 4 is stopped, and expansion of the sleeve 6 starts. The gap between the two 65 and 35 is enlarged, but since the viscosity of the molten metal Z is high, the molten metal Z does not enter the gap.

Next, according to an embodiment of the molding method of the present invention, a molded product having a predetermined shape from a molten metal that is a material Z that is filled in a flowable state by gravity casting using the molding die configured as described above. A description will be given mainly with reference to FIGS.
The molding method of the present invention is to roughly solidify a material Z filled in a flowable state inside a cavity 1 formed in a mold, and mold a molded product of a predetermined shape. The pressure pin 3 that partially pressurizes a predetermined position of the material Z filled in is slidable with respect to the mold, and the solidification of the portion pressed by the pressure pin 3 of the material Z is controlled. The electromagnetic induction heating coil 4 is provided so that the solidification of the material Z filled in the cavity 1 is delayed from the solidification of the surrounding material Z with respect to the portion pressed by the pressure pin 3. In the state controlled by the electromagnetic induction heating coil 4, the pressure is applied by the pressure pin 3.

And the molding method of this invention detects the pressure of the material Z pressurized with the pressurization pin 3, and controls the applied pressure.
In the molding method of the present invention, the portion of the cavity 1 that is in contact with the portion of the material Z that is pressed by the pressing pin 3 is made of a ferromagnetic material having a predetermined Curie point and is heated by an electromagnetic induction heating coil. Materials to be heated 5 and 6 are arranged, the impedance of the electromagnetic induction heating coil 4 is measured, and the heating temperature of the material Z is controlled.
Furthermore, in the molding method of the present invention, a coating agent for preventing the material Z from sticking is applied between the pressure pin 3 and the sliding portion 6.

  When molding a molded product having a predetermined shape, the material Z filled in the cavity 1 in advance corresponding to the relatively thick portion 1A of the cavity 1 in at least one of the upper mold 10 and the lower mold 11 is previously formed. A pressurizing pin 3 that partially pressurizes a predetermined position and an electromagnetic induction heating coil 4 that controls solidification of a portion pressed by the pressurizing pin 3 of the material Z are provided.

  Thereafter, the upper mold 10 and the lower mold 11 are brought into contact with each other to form the cavity 1 therein. At this time, as shown in FIG. 9, the pressurizing pin 3 is advanced by driving means 32 such as a cylinder, and is inserted into the sleeve 6. In this state, as shown in FIG. 10, when the pressing pin 3 is moved backward by the driving means 32 such as a cylinder, a material Z (hereinafter referred to as molten metal) in a state that can flow later flows into the sleeve 6. A pressurizing space K for pressurizing this will be formed. At this time, when the pressure pin 3 is retracted, the outer peripheral surface 35 of the pressure pin 3 is discharged by discharging the coating agent from the nozzle 90 held at the lower end of the sleeve 6 (in the case shown in FIG. 10). In this case, a coating agent is applied.

  Thereafter, as shown in FIG. 1, the molten metal Z is supplied from the gate 14. The molten metal Z is filled into the cavity 1 from the gate 14 through the gate 15. The molten metal Z also flows into the pressurizing space K formed in the sleeve 6. The present invention is not limited to filling the molten metal Z after the pressure pin 3 is retracted to form the pressure space K in the sleeve 6, and the pressure pin 3 is filled while filling the molten metal Z. The pressure pin 3 may be retracted after the molten metal Z is filled.

  When the molten metal Z is filled, a current is passed through the electromagnetic induction heating coil 4. The pin body 30 and the support plate 31 of the pressure pin 3 are made of a soft magnetic material, and the pressure member 5 and the sleeve 6 of the pressure pin 3 that is a material to be heated are made of a ferromagnetic material. The materials 5 and 6 are selectively concentrated and heated. Since the pressure member 5 and sleeve 6 of the pressure pin 3 made of a ferromagnetic material have a Curie point, the impedance of the pressure pin 3 is measured by measuring the impedance of the electromagnetic induction heating coil 4. Since it can be detected that the pressure member 5 and the sleeve 6 exceed the Curie point, abnormal overheating of the heated materials 5 and 6 can be prevented. The electromagnetic induction heating coil 4 can also generate vibrations that act to inhibit the molten metal Z from solidifying when a current having a specific frequency is applied.

  When the filling of the molten metal Z is completed, a predetermined time T1 is passed in that state, and it is determined whether the solidification time exceeds the predetermined time T1 (S1 in FIG. 14). If the coagulation time has not passed the predetermined time T1 (NO in S1 in FIG. 14), this determination is repeatedly performed until the coagulation time has passed the predetermined time T1.

  Here, as shown in FIG. 11, the molten metal Z filled in the cavity 1 solidifies and shrinks as the temperature decreases with the passage of the predetermined time T1. And in the part 1B where the thickness of the cavity 1 is thin, the molten metal Z is relatively quickly cooled and solidified. Therefore, the molten metal (molded product) Z contracts from the thin part 1B, and the directional solidification is achieved in which the shortage of the molten metal Z due to the contraction is replenished from the thick part 1A that has not yet solidified. .

  The molten metal Z flowing into the pressurizing space K formed in the sleeve 6 is selectively heated by the electromagnetic induction heating coil 4 to pressurize the pressurizing member 5 and the sleeve 6 of the pressurizing pin 3 and generate vibration. Therefore, the temperature is maintained or heated, and the vibration is applied so that the solidification is delayed and is controlled to be in a state suitable for being pressurized by the advancement of the pressure pin 3. . Therefore, as shown in FIG. 12, when the pressurizing pin 3 is advanced to pressurize the molten metal Z in the pressurizing space K, it is semi-solidified with a relatively small pressure (a state in which a liquid phase and a solid phase are mixed). It is possible to apply pressure without destroying the tissue.

  Next, in this embodiment, as described above, when the solidification time has passed the predetermined time T1 (in the case of YES in S1 of FIG. 14), the pressure of the molten metal Z pressurized by the pressure pin 3 Is detected by the pressure sensor 80 (FIG. 3) (S2 in FIG. 14). When the molten metal Z is pressurized, the molten metal Z enters the hole 82 of the insulating material 81 and detects whether the periphery of the insulating material 81 and the conductive material 83 are energized by the molten metal Z. It can be determined whether or not Z is pressurized at a set pressure. And when it determines with the molten metal Z not being pressurized with the set pressure P1, (in the case of NO in S2 of FIG. 14), the pressure of the forward drive of the pressurization pin 3 by the drive means 32 is made to increase. (S3 in FIG. 14), control is performed so as to continue the pressurization. On the other hand, when it is determined that the molten metal Z is pressurized at the set pressure P1 (in the case of YES in S2 of FIG. 14), the pressing force of the pressurizing pin 3 by the driving means 32 is held (FIG. 14). S4).

  Thereafter, when the molten metal Z is completely solidified (S5 in FIG. 14) to form a molded product, as shown in FIG. 13, the upper mold 10 and the lower mold 11 are moved relatively apart to open the mold. (S6 in FIG. 14), the pressure pin 3 is further driven forward to release the molded product from the lower mold 11 (in the case of this embodiment), and when it is determined that the mold opening is completed (FIG. 14). 14 (S7), the pressure of the driving means 32 for driving the pressure pin 3 forward is released (S8 in FIG. 14), the molded product is taken out, and one molding cycle is completed.

  In the present invention, since the solidification of the molten metal Z in the pressurizing space K is controlled by the electromagnetic induction heating coil 4, the molten metal Z in the pressurizing space K is pressurized by the pressurizing pin 3 in an optimum state. Can do. And since the to-be-heated materials 5 and 6 used as the part which comprises the pressurization space K were comprised with the ferromagnetic material, and the circumference | surroundings 30, 31, and 7 were comprised with the soft magnetic material with high magnetic permeability, It is possible to easily control the solidification state of the molten metal Z with less energy at an accurate temperature.

  The present invention is not limited to the case where the molten metal Z in which the metal material is melted by gravity casting as described above is poured into a molding die to form a casting as a molded product of a predetermined shape. The present invention can also be applied to the case where a heat-melted synthetic resin material is injection-filled into a mold. In this case, instead of the pressure sensor 80 shown in FIG. 3, another type of pressure sensor such as a strain gauge is used.

It is sectional drawing which showed roughly one Embodiment of the shaping | molding die in this invention. It is the partial expanded sectional view shown in order to demonstrate one Embodiment of the partial pressurization means in this invention. It is a conceptual diagram which shows one Embodiment of the pressure sensor in this invention. It is the partial expanded sectional view shown in order to demonstrate the coating agent application | coating means in this invention. In this invention, it is sectional drawing shown in order to demonstrate the magnetic force line generate | occur | produced by the electromagnetic induction heating coil in the state which advanced the pressurization pin. In this invention, it is sectional drawing shown in order to demonstrate the magnetic force line generate | occur | produced by the electromagnetic induction heating coil in the state which retracted the pressurization pin and formed the pressurization space. It is sectional drawing for demonstrating another embodiment and operation | movement of the sleeve in this invention. It is sectional drawing for demonstrating another embodiment and operation | movement of the sleeve in this invention. It is sectional drawing of the state which the pressurization pin advanced, shown in order to demonstrate the shaping | molding method of this invention. FIG. 10 is a cross-sectional view of a state where a pressure space is formed by retreating the pressure pin from the state of FIG. 9. It is sectional drawing of the state which passed predetermined time from the state of FIG. It is sectional drawing of the state which advances a pressurization pin from the state of FIG. 11, and pressurizes the molten metal in pressurization space. It is sectional drawing which shows the state which opened the mold from the state of FIG. 5 is a flowchart shown for explaining control when the molten metal is partially pressurized with a pressure pin in the molding method of the present invention. It is sectional drawing shown in order to demonstrate the conventional common casting_mold | template used with the gravity casting method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1: Cavity, 2: Partial pressurization means, 3: Pressurization pin, 4: Electromagnetic induction heating coil, 5: Pressurization member (heated material consisting of ferromagnetic material), 6: Sleeve (from ferromagnetic material) 7: heat insulation layer (around the material to be heated), 8: pressure control means, 9: coating agent application means, 30: pin body (soft magnetic material or insulating laminated metal structure), 31: support Plate (soft magnetic material or insulating laminated metal structure), M: lines of magnetic force, Z: molten metal (material)

Claims (13)

A mold for forming a cavity for solidifying a material filled inside in a flowable state to form a molded product of a predetermined shape,
A pressure pin that is slidably provided at a predetermined position and partially pressurizes the predetermined position of the material filled in the cavity;
An electromagnetic induction heating coil for controlling solidification of a portion of the material pressed by the pressing pin.   The material to be heated, which is made of a ferromagnetic material and is heated by the electromagnetic induction heating coil, is disposed at a portion of the cavity that is in contact with a portion to be pressed by a pressure pin of the material. 2. The mold according to 1.   The molding die according to claim 2, wherein a portion of the periphery of the material to be heated through which a magnetic line of force generated by the electromagnetic induction heating coil passes is made of a soft magnetic material.   The molding die according to claim 2 or 3, wherein a periphery of the material to be heated has an insulating laminated metal structure that prevents heating by the electromagnetic induction heating coil.   The mold according to any one of claims 2 to 4, wherein the periphery of the material to be heated in the cavity is constituted by a heat insulating layer that maintains the temperature of the material.   The molding according to any one of claims 1 to 5, further comprising pressure control means for detecting the pressure of the material pressed by the pressing pin and controlling the pressure. Type.   The material to be heated is made of a ferromagnetic material having a predetermined Curie point, and further comprises temperature control means for controlling the heating temperature of the material by measuring the impedance of the electromagnetic induction heating coil. The mold according to any one of claims 2 to 6.   The molding according to any one of claims 1 to 7, further comprising a coating agent applying means for applying a coating agent for preventing the material from adhering to a portion sliding with the pressure pin. Type. The portion that slides with the pressure pin is constituted by a sleeve,
2. The material of the pressure pin and the sleeve is selected such that the distance between the outer peripheral surface of the pressure pin and the inner peripheral surface of the sleeve is reduced as the temperature rises. The mold according to any one of 8. A method of forming a molded product of a predetermined shape by solidifying a material filled in a flowable state inside a cavity formed in a mold,
A pressure pin that partially pressurizes a predetermined position of the material filled in the cavity is slidably provided at a predetermined position, and solidification of a portion of the material that is pressed by the pressure pin is controlled. Provide an electromagnetic induction heating coil to
In the state in which the solidification of the material filled in the cavity is controlled by the electromagnetic induction heating coil so as to delay the solidification of the portion pressurized by the pressure pin from the surrounding solidification. A molding method characterized by pressurizing with a pressure pin.   The molding method according to claim 10, wherein the pressure of the material pressed by the pressure pin is detected and the pressure is controlled. A material to be heated, which is made of a ferromagnetic material having a predetermined Curie point and is heated by the electromagnetic induction heating coil, is disposed in a portion of the cavity that is in contact with a portion pressed by the pressure pin of the material,
The molding method according to claim 10 or 11, wherein an impedance of the electromagnetic induction heating coil is measured to control a heating temperature of the material. The molding method according to any one of claims 10 to 12, wherein a coating agent for preventing the material from sticking is applied to a portion sliding with the pressure pin.

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