JP2014205171A - Casting method of die-casting product and die-casting product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a casting method of a die-casting product which can easily and surely embed an insert member at a normal position of a die-casting product, and to provide the die-casting product in which the insert member is embedded at the normal position.SOLUTION: In a casting method of a die-casting product, an insert member I supported by a support part 2c inside a cavity C formed by closing a movable mold 2 and a stationary mold 3 is pressed to the movable mold 2 by a press member 3g, projecting from the stationary mold 3 into the cavity C, to be moved to a normal position, and after the press member 3g is retreated from the inside of the cavity C, molten metal M is injected into the cavity C. The die-casting product is die-casted by the casting method.

Description

  The present invention relates to a casting method of a die cast product for casting a die cast product in which an insert member is embedded, and a die cast product in which an insert member is embedded at a normal position.

  As a die-cast product cast by die casting that injects molten metal such as aluminum alloy at high speed and high pressure into the cavity formed in the mold, wear resistance, high strength, etc. are required than the metal to be injected. In a die-cast product having a certain portion, an insert member made of a material having high wear resistance, strength, etc. is embedded in the portion where the wear resistance is required. As one method of embedding an insert member in a die cast product, a method of embedding the insert member by placing the insert member in a cavity and injecting molten metal in that state during die casting is known. ing.

  Specifically, for example, in the case of an engine cylinder block that is a die-cast product in which an insert member is embedded, the cylinder portion on which the piston slides is formed of a material having high wear resistance and strength. It is necessary to embed a cylindrical sleeve as an insert member. When embedding such a cylindrical insert member, a columnar support portion into which the insert member is inserted is provided in a cavity formed by a pair of molds, and the pair of molds are opened and supported. A casting method has been proposed in which an insert member is supported on a portion, a pair of molds are closed to form a cavity, and molten metal is injected into the cavity to embed the insert member (Patent Document 1). .

  In the casting method of the die cast product in Patent Document 1, the insert member is embedded so that one end face of the insert member is exposed to the outside. When the insert member is embedded in such a state, when die casting is performed, if there is a gap between the end surface of the insert member on the exposed side and the mold, high-speed, high-pressure molten metal enters the gap. Therefore, there is a problem that the insert member is pushed and moved. Therefore, it is necessary to perform die casting in a state where the end surface of the insert member is in contact with the mold. However, when the insert member moves along the support portion in the cavity due to vibration or the like when closing the mold and a gap is formed between the mold and the mold, the insert member is There is a problem that it is pushed and moves. For this reason, the fitting between the support portion and the insert member is tightened so that the insert member does not move from the normal position.

  When the fitting between the support portion and the insert member is tight, when the temperature of the mold rises due to the molten metal, the support portion expands and the insert member becomes difficult to fit into the support portion or cannot be fitted. Problems occur. Therefore, in Patent Document 1, a cooling chamber is formed in the support portion, and the support portion is cooled by circulating cooling water through the cooling chamber, thereby suppressing the expansion of the support portion.

  However, even if the support portion is cooled as in Patent Document 1, the expansion of the support portion cannot be sufficiently suppressed, and the problem that the insert member is difficult to fit into the support portion cannot be solved. . Therefore, even if an insert member is tried to be fitted until one end surface comes into contact with the mold, the insert member stops halfway, and if the end surface is cast without being in contact with the mold, the end surface and the mold In this case, there is a problem that the molten metal is filled between the two and the defective product in which the end face of the insert member is not exposed is cast.

  On the other hand, it can be considered that the end surface is brought into contact with the mold surely by fitting the insert member while hitting it. However, in this case, since it takes time to fit the insert member into the support portion, there is a problem that the number of die castings per hour is reduced and the manufacturing cost is increased. Further, depending on the degree of expansion of the support portion, even if the insert member is hit, the end surface cannot be brought into contact with the mold, and a defective product may be cast.

  In addition, when the fitting between the support portion and the insert member is tightened as in Patent Document 1, high dimensional accuracy is required for the support portion and the insert member, which causes a problem that the insert member becomes expensive. Furthermore, when the cooling water is circulated through the support portion as in Patent Document 1, it is necessary to form a flow path through which the cooling water circulates in the mold, which complicates the structure of the mold. In addition, there is a problem that the cost is increased, and the problem of water leakage is likely to occur because the mold becomes complicated.

  Therefore, in view of the above circumstances, the present invention provides a die casting casting method capable of easily and reliably embedding an insert member at a normal position of the die cast product, and a die casting in which the insert member is embedded at a normal position. The issue is to provide castings.

  In order to solve the above-mentioned problem, a casting method of a die-cast product according to the present invention is described as follows: “An insert member supported by a support part in a cavity formed by closing a pair of molds is inserted into one of the above-mentioned molds. The pressing member protruded from the mold into the cavity is pressed against the other mold and moved to the normal position, and after the pressing member is retracted from within the cavity, molten metal is injected into the cavity. It is characterized by that.

  Here, the “supporting portion” may be a protruding portion into which the insert member is inserted, a hollow portion into which the insert member is inserted, or the like. In addition, examples of the “pressing member” include a member that presses a part of the insert member, a member that presses the entire insert member, and the like. Examples of the mechanism for moving the pressing member include a mechanism using a hydraulic cylinder and a mechanism using an electric motor.

  The “regular position” means the position of the designed insert member in the die cast product, and may be a position where the insert is in contact with the other mold, or the insert is separated from any mold. The position where it is.

  According to the casting method of the die cast product of the present invention, details will be described later, but even if the insert member moves from the normal position due to vibration during mold closing, the insert member is moved to the normal position by the pressing member after closing the mold. Since it can be returned (moved), by injecting molten metal into the cavity in this state, a die-cast product in which the insert member is embedded in the normal position can be cast (manufactured).

  Therefore, as in the prior art, the insert member can be embedded in the normal position without tightening the fitting between the support portion and the insert member in order to prevent the insert member from moving due to vibration at the time of mold closing. it can. That is, since the fitting between the support portion and the insert member can be loosened, the operation of fitting the insert member into the mold can be facilitated, and the number of die cast castings per hour can be increased. Moreover, the dimensional accuracy of the insert member can be lowered, and the cost for the insert member can be reduced.

  Further, since the fitting between the support portion and the insert member can be loosened as described above, there is no need to circulate cooling water through the support portion in order to suppress the expansion of the support portion as in Patent Document 1. Since the mold does not need to have a complicated structure, it is possible to reduce an increase in the cost of the mold and to suppress the occurrence of a water leakage problem in the mold.

  By the way, it is conceivable to cast while pressing the insert member with the pressing member so as not to move from the normal position by injecting molten metal into the cavity with the pressing member protruding into the cavity. However, in this case, since a hole due to the pressing member is formed in the cast die-cast product, the above method cannot be used for the die-cast product in which this hole causes a problem. On the other hand, in the present invention, since the pressing member is retracted from the cavity before the molten metal is injected, a hole due to the pressing member is not formed in the cast die cast product, and various die castings are performed. It can correspond to goods.

  The die cast product according to the present invention is characterized in that it is “die cast by the above casting method of die cast product”.

  According to the die cast product of the present invention, since it is die cast by the above casting method, a good die cast product in which the insert member is embedded at the normal position and the hole by the pressing member is not formed on the surface. It is. Moreover, the die-casting product may be provided with slight unevenness (for example, parting line) formed by one mold and the pressing member on the surface. It can be determined that the die casting is performed by the above casting method based on the presence of the slight unevenness.

  As described above, according to the present invention, a method for manufacturing a die-cast product capable of easily and reliably burying an insert member at a regular position of the die-cast product, and a die-cast casting in which the insert member is embedded at a regular position. Can provide goods.

It is explanatory drawing of the die-casting method which is one Embodiment of this invention. It is explanatory drawing of the die-casting method following FIG. It is explanatory drawing of the die-casting method following FIG.

  A casting method of a die cast product and a die cast product P according to an embodiment of the present invention will be described in detail with reference to FIGS. The casting method of the die cast product of this embodiment is a method of casting the die cast product P in which the insert member I is embedded at a regular position. First, a schematic configuration of a die casting apparatus 1 to which the casting method of the die cast product of the present embodiment is applied will be described. The die casting apparatus 1 includes a movable mold 2 and a fixed mold 3 for forming a cavity C having substantially the same shape as the die cast product P.

  Although not shown, the die-casting apparatus 1 is attached to the apparatus main body having the movable mold 2 movably attached and the fixed mold 3 fixed at a position facing the movable mold 2. A moving device that moves the movable mold 2 in a direction toward or away from the fixed mold 3, and an injection device that is attached to the apparatus main body and injects molten metal into the cavity C. Yes.

  The movable mold 2 includes a movable mold body 2a that is formed in a block shape as a whole, and a movable mold surface 2b that is formed on a surface of the movable mold body 2a that faces the fixed mold 3 and that forms a cavity C. And a support portion 2c that is formed on the movable mold surface 2b and supports the insert member I.

  The fixed mold 3 includes a fixed mold main body 3a that is formed in a block shape as a whole, a fixed mold surface 3b that is formed on a surface of the fixed mold main body 3a that faces the movable mold 2 and that forms a cavity C. It is equipped with. Further, the fixed mold 3 is mounted in the mounting space 3c having a predetermined width formed between the fixed mold body 3a and the opposite side of the fixed mold surface 3b, and the fixed mold body 3a. The hydraulic cylinder 3e in which the piston rod 3d advances and retreats toward the 3b side (movable mold 2 side), the flat sliding plate 3f attached to the tip of the piston rod 3d of the hydraulic cylinder 3e, and the support of the movable mold 2 One rod-shaped pressing member 3g attached to the sliding plate 3f at a position corresponding to the portion 2b, and a guide rod 3h for guiding the sliding plate 3f in a direction parallel to the piston rod 3d are provided.

  The pressing member 3g is slidably inserted into a guide hole 3i penetrating between the fixed mold surface 3b and the mounting space 3c in the fixed mold main body 3a. The pressing member 3g is formed so that the tip surface close to the movable mold 2 coincides with the fixed mold surface 3b when the piston rod 3d is in the retracted position where it is immersed in the hydraulic cylinder 3e. Further, the pressing member 3g extends the piston rod 3d by the hydraulic cylinder 3e so that the tip surface close to the movable mold 2 protrudes from the fixed mold surface 3b in the direction of the movable mold 2. Thereby, the front-end | tip of the press member 3g can be made to contact and press the insert member I in the cavity C currently supported by the support part 2c.

  Here, the fixed mold 3 of the present embodiment corresponds to one mold of the present invention, and the movable mold 2 of the present embodiment corresponds to the other mold of the present invention.

  The die-casting apparatus 1 moves the movable mold 2 in the direction of the fixed mold 3 by the moving device, and aligns the movable mold 2 and the fixed mold 3 with each other and closes the mold (closes the mold). A cavity C partitioned by the surface 2b and the fixed-side mold surface 3b can be formed. In addition, about the runner etc. for guide | inducing a molten metal in the cavity C, illustration is abbreviate | omitted.

  Next, a casting method using the die casting apparatus 1 will be described. First, the movable mold 2 is moved away from the fixed mold 3 by the moving device, and the movable mold 2 and the fixed mold 3 are separated to make the mold open (see FIG. 1A). In this state, the insert member I is fitted into and supported by the support portion 2c of the movable mold 2 (see FIG. 1B). At this time, the insert member I may not be supported at the regular position. Subsequently, the movable mold 2 is moved in the direction of the fixed mold 3 by the moving device, the movable mold 2 and the fixed mold 3 are matched with each other, and the mold is closed (see FIG. 1C). Thereby, a cavity C is formed between the movable mold 2 and the fixed mold 3.

  When the movable mold 2 and the fixed mold 3 are closed, the hydraulic cylinder 3e is driven to extend the piston rod 3d, thereby moving the pressing member 3g in the direction of the movable mold 2 and projecting into the cavity C. And while making the front-end | tip of the press member 3g contact a part of insert member I, the insert member I is pressed to the direction of movable mold | type 2 (right direction in a figure), and it is opposite to the press member 3g of insert member I. The end face on the side is brought into contact with the movable mold 2 (see FIG. 2D). Thereby, it will be in the state where insert member I was supported by the regular position.

  When the insert member I is moved to the normal position by the protrusion of the pressing member 3g, the hydraulic cylinder 3e is driven in reverse to move the piston rod 3d away from the movable die 2 and move backward from the cavity C. (See FIG. 2 (e)). Thereafter, the molten metal M is injected into the cavity C by an injection device (see FIG. 2 (f)). At this time, since the end surface of the insert member I is in contact with the movable mold 2, the high-speed and high-pressure molten metal M does not enter between the end surface of the insert member I and the movable mold 2. As a result, the insert member I is not pushed to the fixed mold 3 side, and the insert member I is embedded at the normal position.

  When the molten metal M in the cavity C is cured (see FIG. 3G), the movable mold 2 is moved away from the fixed mold 3 by the moving device to open the mold (see FIG. 3H). ) Take out the die-cast product P from the movable mold 2 (see FIG. 3 (i)). In addition, you may make it take out the die-cast goods P from the movable mold | type 2 simultaneously with a mold opening. Thereby, the die-cast product P in which the insert member I is embedded at the regular position can be cast.

  Next, after the mold is closed using the die casting apparatus 1 described above, the insert member I is moved to the normal position by the pressing member 3g and the conventional casting without using the pressing member 3g. A test comparing the method (conventional casting method) was conducted. Specifically, whether or not the insert member I is positioned in the normal position in the die-cast product P when die casting is performed by each casting method with different fitting tolerances between the support portion 2c and the insert member I. The defective rate was examined and the result is shown in Table 1 below.

  From this test result, it can be seen that the defect rate decreases in the present casting method as the fitting tolerance between the support portion 2c and the insert member I is increased (loosened). The reason why the defect rate increases as the fitting tolerance becomes smaller (tighter) is that even if the insert member I is pressed by the pressing member 3g, the insert member I moves to the normal position due to the expansion of the support portion 2c due to heat. It seems to be difficult to move. On the other hand, in the conventional casting method, it can be seen that the defect rate increases as the fitting tolerance increases. This is because, as the fitting tolerance increases, the insert member I becomes easier to move with respect to the support portion 2c. Therefore, the insert member I moves from the normal position due to vibration or the like when the mold is closed.

  Thus, according to this embodiment, even if the insert member I moves from the normal position due to vibration during mold closing, the insert member I can be moved to the normal position by the pressing member 3g after the mold is closed. Therefore, by injecting the molten metal M into the cavity C in that state, it is possible to cast (manufacture) the die cast product P in which the insert member I is embedded at the regular position.

  Therefore, the insert member I can be brought into the normal position without the need to tighten the fitting between the support member 2c and the insert member I in order to prevent the insert member I from moving due to the vibration at the time of mold closing. Can be buried. That is, since the fitting between the support portion 2c and the insert member I can be loosened, the insertion work of the insert member I with respect to the support portion 2c of the movable mold 2 can be facilitated, and the die cast product P per hour can be facilitated. The number of castings can be increased. Further, the dimensional accuracy of the insert member I can be lowered, and the cost for the insert member I can be reduced.

  Further, since the fitting between the support portion 2c and the insert member I can be loosened, there is no need to circulate cooling water through the support portion 2c in order to suppress the expansion of the support portion 2c as in the prior art. It is possible to avoid an increase in the cost of the mold by avoiding the complexity of the structure.

  Further, since the pressing member 3g is retracted from the cavity C before the molten metal M is injected, a hole due to the pressing member 3g is not formed in the cast die cast product P, and various die castings are performed. This can correspond to the product P. Moreover, a parting line between the pressing member 3g and the guide hole 3i appears slightly on the surface of the die cast product P. Although this parting line does not become a problem as a product, it is the die cast product P of the present embodiment cast using the casting method of the die cast product of the present embodiment due to the presence of the parting line. It can be determined whether or not.

  The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various improvements can be made without departing from the scope of the present invention as described below. And design changes are possible.

  For example, in the above embodiment, the example in which the movable die 2 is provided with the support portion 2c has been described. However, the present invention is not limited to this, and the fixed die 3 is provided with the support portion 2c for supporting the insert member I. Also good. In the above embodiment, the pressing member 3g protrudes or retreats from the fixed mold 3 into the cavity C. However, the present invention is not limited to this, and the pressing member 3g is moved from the movable mold 2 into the cavity C. You may make it project or retract.

  Furthermore, in the above-described embodiment, the example of the position where the end surface of the insert member I is in contact with the movable mold 2 is shown as the normal position of the insert member I. However, the present invention is not limited to this. It is good also as a position where an end surface does not contact | abut neither the movable mold | type 2 nor the fixed mold | type 3. FIG.

  In the above-described embodiment, an example in which a part of the insert member I is pressed by one bar-shaped pressing member 3g has been described. However, the present invention is not limited to this, and a plurality of positions of the insert member I are pressed. Alternatively, the entire insert member I may be pressed, and the insert member I can be easily moved to the normal position by increasing the portion to be pressed.

DESCRIPTION OF SYMBOLS 1 Die casting apparatus 2 Movable type | mold 2a Movable type | mold main body 2b Movable side type | mold surface 2c Support part 3 Fixed type | mold 3a Fixed type | mold main body 3b Fixed side type | mold surface 3c Mounting space 3d Piston rod 3e Hydraulic cylinder 3f Sliding plate 3g Pressing member 3h Guide rod 3i Guide hole C Cavity P Die cast product I Insert member M Molten metal

JP-A-6-71405

Claims (2)

  An insert member supported by a support portion in a cavity formed by closing a pair of molds is pressed against the other mold by a pressing member protruding from the one mold into the cavity. A method for casting a die-cast product, wherein the molten metal is injected into the cavity after moving to a position and retracting the pressing member from the cavity.   A die-cast product, which is die-cast by the casting method of the die-cast product according to claim 1.

Images