JP2019098384A - Die cast sleeve - Google Patents

Abstract

A die casting sleeve capable of maintaining the temperature of a molten metal while suppressing thermal deformation of the die casting sleeve. A die casting sleeve 20 according to an embodiment is formed of a laminated cylindrical body, and is disposed such that an axial direction is a substantially horizontal direction. The die-casting sleeve 20 is provided on the outer side of the first layer 21 and the first layer 21 constituting the inner peripheral surface in contact with the molten metal W, and has a second vertical cross-sectional area larger than the vertical upper cross-sectional area. A layer 23, a third layer 23 provided on the outer side of the second layer 23 and constituting the outer peripheral surface, a heat insulating layer 24 provided between the first layer 21 and the second layer 22, and a second layer 22. And a cooling layer 25 provided between the second layer 23 and the third layer 23. [Selection] Figure 3

Description

  The present invention relates to a die casting sleeve.

  In a die casting machine, a die casting sleeve for temporarily storing a molten metal for injection is used. The molten metal in the die casting sleeve is injected into a cavity in communication with the die casting sleeve by means of a plunger tip that slides inside.

  When molten metal is supplied into the die-casting sleeve, the lower side of the die-casting sleeve directly contacts the molten metal to become high temperature, but heat is transferred from the lower side to the upper side, so a temperature difference occurs between the lower and upper sides of the die-casting sleeve Do. Due to this temperature difference, there is a possibility that so-called banana bending, in which the die-cast sleeve warps downward, may occur. Patent Document 1 discloses a technique for suppressing such thermal deformation of a die-casting sleeve.

  In addition, after the molten metal is supplied to the die-casting sleeve, the heat of the molten metal may be dissipated through the die-casting sleeve, and the fluidity may be reduced due to the temperature decrease. If the fluidity of the molten metal is reduced, the injectability into the cavity is reduced, which leads to the deterioration of the quality of the molded article. In order to solve such a problem, the technique which suppresses the temperature fall of the molten metal is proposed by patent documents 2 and 3. FIG.

JP, 2013-163192, A JP 2002-018566 A Japanese Patent Application Publication No. 2003-039145

  The suppression of the thermal deformation generated due to the temperature difference between the lower side and the upper side of the die casting sleeve and the suppression of the temperature drop of the molten metal which adversely affect the quality of the molded product are in a trade-off relationship with each other. That is, when the portion of the die-cast sleeve to which the molten metal is supplied is cooled in order to suppress the thermal deformation of the die-cast sleeve, the molten metal may solidify as soon as the molten metal touches the portion, and the initial solidified pieces may increase. There is a need for the development of a die-casting sleeve that simultaneously satisfies both of these characteristics.

  This invention is made in view of such a problem, The objective of this invention is providing the die-cast sleeve which can hold | maintain the temperature of a molten metal, suppressing the thermal deformation of a die-cast sleeve. is there.

  A die-casting sleeve according to one aspect of the present invention is formed of a laminated cylindrical body, and is disposed so that the axial direction is substantially horizontal, and a plunger tip for injecting molten metal stored in a communicating cavity is fitted. It is a die-cast sleeve to be inserted, which is provided on the outer side of the first layer constituting the inner circumferential surface in contact with the molten metal and the first layer, and the cross-sectional area on the lower side in the vertical direction is larger than the cross-sectional area on the upper side in the vertical direction A second layer, a third layer provided on the outer side of the second layer and constituting an outer peripheral surface, a heat insulating layer provided between the first layer and the second layer, and the second layer And a cooling layer provided between the third layer.

  ADVANTAGE OF THE INVENTION According to this invention, the die-cast sleeve which can hold | maintain the temperature of a molten metal can be provided, suppressing the thermal deformation of a die-cast sleeve.

It is a typical sectional view of the die-cast machine concerning an embodiment. It is an expanded sectional view of the die-cast sleeve which concerns on embodiment. It is the III-III sectional view of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same reference numerals are given to the same components in the respective drawings, and the overlapping description will be omitted.

  The present invention relates to a die-cast sleeve into which a molten metal (molten metal) such as aluminum is supplied and a plunger tip for injecting the molten metal stored in a communicating cavity is inserted. The lower side of the die casting sleeve is hot because it directly contacts the molten metal, and heat is gradually transferred upward, so that a temperature difference occurs between the lower side and the upper side. The banana bending of the die casting sleeve occurs due to the temperature difference between the lower side and the upper side. In order to suppress the bending of the banana, it is necessary to select a material or a structure having a small linear expansion coefficient (not easily deformed). On the other hand, the initial solidification pieces are generated as the temperature difference between the die cast sleeve body and the molten metal increases. In order to suppress the initial solidified pieces, it is necessary to select a material or structure with low thermal conductivity (heat transfer is difficult).

  In the current material, there is no material that can satisfy these two characteristics and can form the shape of the die-casting sleeve, and it is made of a material having either one of the characteristics. In addition, the die-casting sleeve needs to be strong, and the degree of freedom in manufacturing is low. In addition, securing the thermal insulation structurally to suppress the initial solidified pieces has a problem that the manufacturing cost increases. The present inventors have devised the following invention which simultaneously satisfies the above two characteristics on the background of such circumstances.

  First, a die casting machine 10 according to the embodiment will be described with reference to FIG. In the following drawings, only parts necessary for the description of the invention are shown, and some of the parts included in a typical die casting machine are not shown. In FIG. 1, the x direction represents the horizontal direction, and the z direction represents the vertical direction.

  The die casting machine 10 includes a movable die 11, a fixed die 12, a runner 13, a rudder 14, a plunger 15, a tank 16, a die casting sleeve 20, a first pump P1, and a second pump P2. The die casting machine 10 is, for example, a high pressure casting apparatus for forming a molded product made of an aluminum alloy whose main raw material is aluminum.

  The movable mold 11 and the fixed mold 12 constitute a set of molds. Each of the movable mold 11 and the fixed mold 12 has a cavity surface for molding a part of the shape of the molded product. The movable mold 11 is configured to be able to approach and separate from the fixed mold 12. When the movable mold 11 and the fixed mold 12 are closed, a cavity CV for a molded article is formed.

  The die casting sleeve 20 is attached to the fixed die 12. The die casting sleeve 20 is a laminated cylindrical body composed of a plurality of layers which temporarily stores the molten metal W before being injected into the cavity CV. The die casting sleeve 20 is disposed such that the axial direction is substantially horizontal (x direction). The configuration of the die casting sleeve 20 will be described in detail later. The space WS inside the die casting sleeve 20 and the cavity CV are in communication by a runner 13 (runner). The runner 13 is a flow path formed when the movable mold 11 and the fixed mold 12 are closed.

  A plunger 15 for injecting the molten metal is inserted into the die-casting sleeve 20. The plunger 15 has a plunger tip 15a and a rod 15b. The plunger tip 15 a is inserted into the inner peripheral surface of the die casting sleeve 20. A rod 15b is connected to the rear end of the plunger tip 15a. The plunger tip 15 a slides in the die casting sleeve 20 by advancing / retracting the rod 15 b by an actuator (not shown).

  A supply port (not shown) for supplying the molten metal W is provided on the upper side in the vertical direction (z direction) of the die casting sleeve 20. The molten metal W is supplied from the supply port by the ladle 14. By pushing out the molten metal W by the plunger 15, the molten metal W in the die casting sleeve 20 flows into the runner 13 and reaches the cavity CV.

  The movable mold 11 and the fixed mold 12 are each provided with a cooling water channel (not shown). The cooling water stored in the tank 16 is sent to the cooling water channels of the movable mold 11 and the fixed mold 12 by the first pump P1. After the molten metal filled in the cavity CV is cooled by the cooled mold and the molten metal solidifies, the movable mold 11 is moved away from the fixed mold 12 to take out the molded product.

  The cooling water stored in the tank 16 is also sent to a cooling layer 25 of the die casting sleeve 20 described later. Further, the cooling water from the movable mold 11, the fixed mold 12, and the cooling layer 25 is returned to the tank 16 by the second pump P2. The first pump P1 and the second pump P2 serve as a cooling water circulation mechanism that circulates the cooling water.

  Next, the configuration of the die casting sleeve 20 will be described with reference to FIGS. FIG. 2 is an enlarged cross-sectional view of the die casting sleeve according to the embodiment. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. As shown to FIG.2, 3, the die-cast sleeve 20 which concerns on embodiment is equipped with three cylindrical bodies (1st layer 21, 2nd layer 22, 3rd layer 23). A heat insulating layer 24 is provided between the first layer 21 and the second layer 22, and a cooling layer 25 is provided between the second layer 22 and the third layer 23.

  The die casting sleeve 20 has a five-layer structure of a first layer 21, a heat insulating layer 24, a second layer 22, a cooling layer 25, and a third layer 23 in order from the inside. The first layer 21 is an innermost cylinder constituting an inner circumferential surface in contact with the molten metal W. Since the first layer 21 is in direct contact with the molten metal W, the first layer 21 is formed of a material that is not easily melted. As the first layer 21, a metal material, for example, a stainless steel alloy is used.

  The heat insulating layer 24 suppresses the temperature drop of the molten metal W. The first layer 21 and the second layer 22 are connected by the first rib 26. The heat insulating layer 24 is a hollow portion provided between the first layer 21 and the second layer 22. By reducing the pressure in the hollow portion, the heat insulating layer 24 has a highly thermally insulated vacuum structure.

  The second layer 22 is provided outside the first layer 21 via the heat insulating layer 24. As shown in FIG. 3, the upper side in the vertical direction of the second layer 22 has an arc shape, and the uneven portion 28 is formed on the lower side in the vertical direction. Therefore, the cross-sectional area of the second layer 22 is larger on the lower side in the vertical direction than the cross-sectional area on the upper side in the vertical direction. Although it does not specifically limit as a shape of the uneven part 28, For example, semi-elliptic shape, circular shape, protrusion shape, honeycomb shape etc. are mentioned. By forming the uneven portion 28, the surface area on the lower side in the vertical direction of the second layer 22 becomes larger than the surface area on the upper side in the vertical direction. The larger the vertical lower surface area of the second layer 22 is, the more advantageous it is for heat exchange. The second layer 22 is made of an inexpensive and easily processable metal material such as iron.

  The cooling layer 25 cools the second layer 22 and suppresses the thermal deformation of the die casting sleeve 20. The second layer 22 and the third layer 23 are connected by the second rib 27. The cooling layer 25 is a hollow portion between the second layer 22 and the third layer 23. The hollow portion is a flow path through which the cooling water (refrigerant) flows. Since the uneven portion 28 is formed on the lower side in the vertical direction of the second layer 22, the area on the lower side in the vertical direction of the second layer 22 in contact with the cooling water flowing to the cooling layer 25 becomes larger than the upper side. Thereby, the second layer 22 can be cooled efficiently.

  The third layer 23 is provided outside the second layer 22 via the cooling layer 25. The third layer 23 constitutes the outer peripheral surface of the die casting sleeve 20. The third layer 23 is made of an inexpensive and easily processable metal material such as iron. Such a die-casting sleeve 20 having a hollow portion can be manufactured using, for example, a 3D printer. By using a 3D printer, it is possible to form a hollow structure using a rib and a concavo-convex portion 28 having a complicated shape for the purpose of increasing the surface area.

  As described above, since the outside of the first layer 21 in direct contact with the molten metal W has a vacuum structure by the heat insulating layer 24, it has high heat insulation. Thereby, the temperature of the molten metal W can be maintained, and the increase of the solidified pieces can be suppressed. Further, a cooling layer 25 is provided outside the heat insulating layer 24 via the second layer 22. Since the surface area on the lower side in the vertical direction of the second layer 22 is larger than the upper side in the vertical direction, the cooling property on the lower side in the vertical direction of the second layer 22 can be made higher than that on the upper side in the vertical direction. Thereby, the vertical direction lower side of the second layer 22 which becomes high temperature by the molten metal W can be efficiently cooled, the temperature difference between the upper side and the lower side of the die casting sleeve 20 can be reduced, and the thermal deformation of the die casting sleeve 20 is suppressed. It is possible to That is, it becomes possible to simultaneously satisfy both the characteristics of the suppression of the banana bending and the suppression of the temperature drop of the molten metal, which are a trade-off relationship, using an inexpensive material.

  The present invention is not limited to the above embodiment, and can be appropriately modified without departing from the scope of the present invention.

  In the above-mentioned example, although aluminum was used for molten metal, it is also possible to use not only aluminum but other metals for molten metal. Further, the material of the coolant circulating in the mold cooling water channel and the cooling layer 25 of the die casting sleeve 20 is not limited to water (cooling water), for example, a liquid such as an aqueous solution or oil comprising a predetermined component or Gas may be applied.

DESCRIPTION OF SYMBOLS 10 die casting machine 11 movable type 12 fixed type 13 runner 14 ladle 15 plunger 15a plunger tip 15b rod 16 tank 20 die casting sleeve 21 1st layer 22 2nd layer 23 3rd layer 24 thermal insulation layer 25 cooling layer 26 1st rib 27 2nd Rib 28 Uneven part W Molten metal WS Space CV cavity P1 1st pump P2 2nd pump

Claims (1)

A die-cast sleeve, which is formed of a laminated cylindrical body and disposed so that the axial direction is substantially horizontal, into which a plunger tip for injecting molten metal stored in a communicating cavity is inserted,
A first layer constituting an inner circumferential surface in contact with the molten metal;
A second layer provided on the outer side of the first layer and having a larger cross-sectional area on the lower side in the vertical direction than a cross-sectional area on the upper side in the vertical direction;
A third layer provided on the outer side of the second layer and constituting an outer peripheral surface;
A thermal insulation layer provided between the first layer and the second layer;
A cooling layer provided between the second layer and the third layer;
Die-cast sleeve with.

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