JP6134776B1 - Die casting mold - Google Patents

Abstract

A die casting mold having a parting lock for preventing a separation between an intermediate mold and a movable mold when a molded product is taken out. I will provide a. A die casting mold includes a projecting block 17 projecting from a movable mold 5 toward an intermediate mold 4, a groove 18 formed by cutting out a side surface of the projecting block 17, and an intermediate mold 4 And has an engagement piece 19 that extends toward the protruding block 17 and has a tip engaged with the groove portion 18, and a hydraulic cylinder 20 that reciprocates the engagement piece 19. The groove portion 18 is formed on the movable die 5. It has two side surfaces, a near side and a far side, and the far side surface 18a is formed to be inclined, and the tip of the engagement piece 19 is engaged while sliding on the far side surface 18a. [Selection] Figure 1

Description

  The present invention relates to a die casting die applied to a die casting method.

  A mold for molding a die-cast product has a fixed mold connected to an injection sleeve and a movable mold movable relative thereto. The die-cast product forms a space between the fixed mold and the movable mold, and is formed by a molten metal poured from the injection sleeve into the space. That is, most of the die casting molds have a two-sheet structure composed of the above-described fixed mold and movable mold. In the case of molding with such a mold, the runner portion and the molded product remaining in the shape of the runner for filling the molten metal are taken out from the mold as they are integrated, and then the molded product and the runner portion are separated. Thereby, a die-cast product is completed.

  On the other hand, a mold for forming a die-cast product using a center gate, such as an automobile wheel or a saddle shape, often has a three-sheet structure having an intermediate mold between the fixed mold and the movable mold. In the mold having this structure, a runner is provided in the fixed mold, and a pin gate (including a case where the runner is used as a runner) is provided in the intermediate mold. The runner is provided so as to communicate with the molten metal outlet of the injection cylinder, and the pin gate is provided through the intermediate mold. When the fixed mold and the intermediate mold are joined, the runner and the pin gate communicate with each other. The molten metal is poured into a space formed in the gap between the intermediate mold and the movable mold. When the molten metal solidifies, first, the intermediate mold and the movable mold are moved together with respect to the fixed mold. Thereafter, the runner portion corresponding to the exposed runner is removed from the molded product. Next, move the movable die relative to the intermediate die and take out the molded product with the pin gate part remaining in the pin gate shape (this method is used when the pin gate gradient is thin in the fixed die and thick on the product side) This is true for resin molded products, and vice versa).

  The mold having the three-sheet structure is locked by a lock mechanism (parting lock) for preventing the movable mold and the intermediate mold from separating until the runner portion is removed. The timing at which the intermediate mold and the movable mold are separated varies depending on the locking force of the parting lock and the mold restraining force of the molded product. In the case of a mold that requires a large locking force, it was necessary to adjust by attaching multiple parting locks.

  In both the two-sheet mold and the three-sheet mold, the molded product is finally taken out from the mold while being stuck to the movable mold. In the case of the three-sheet mold, if the intermediate mold and the movable mold are slightly separated before the runner portion is removed, the molded product tends to move together with the movable mold. However, since the runner portion still remains in the molded product, the molded product is deformed and cracked, the pin gate remains broken, etc. As a result, the occurrence of defective products and machine troubles frequently occur and the productivity is lowered.

  The parting locks used so far are commercially available products used for resin molding dies, and most of them are of the type that locks bars and rods with the force of a spring or the like. Such a commercial product has a problem in durability and reliability in an environment in which an intermediate mold having 5 tons or more is used at a high temperature, such as die casting. In addition, this locking mechanism locks in a direction that the mold does not open until a certain force is applied, but the force that tightens the intermediate mold and the movable mold does not act, so depending on the mounting to the mold, it is already parting In many cases, clearance is generated on the surface (for example, even if a loose screw is locked, fastening is similar to a loose state). Even during casting, the intermediate mold, the movable mold and the fixed mold are in close contact with each other by the clamping force, so the molten metal is unlikely to be ejected from the parting surface, but it is movable with the intermediate mold as soon as the clamping force is released. The mold acts in the direction of mold opening and is easy to open with a slight force.

  The parting lock used in the resin molding die has a weak locking force when used in a die casting die. Most parting locks are used to prevent mold opening, and even if they are strictly attached, the gap between the parting surfaces of the intermediate mold and the movable mold does not become zero. As long as such a parting lock is used, it is not possible to easily reduce defects with a mold having a three-sheet structure. In order to solve these problems, when the intermediate mold is opened from the fixed mold, there is a high demand for preventing the intermediate mold and the movable mold from being opened. Such a parting lock has been proposed in various shapes as disclosed in Patent Document 1, but it is necessary to further improve the locking force in consideration of a die-cast product.

JP 2008-119953 A

  The present invention is based on the above-described conventional technique, and is a three-sheet mold including a fixed mold, an intermediate mold, and a movable mold, and prevents the intermediate mold and the movable mold from being separated when a molded product is taken out. An object of the present invention is to provide a die casting mold having a parting lock.

  In order to achieve the above object, in the present invention, a fixed mold to be connected to a plunger providing molten metal, an intermediate mold connected to and spaced from the fixed mold, and a movable mold connected to and spaced from the intermediate mold A cavity formed as a gap between the intermediate mold and the movable mold when the intermediate mold and the movable mold are connected, and a casting port formed in the fixed mold as a connection port of the plunger In the die casting mold comprising the fixed mold and the molten metal passage passing through the intermediate mold from the casting port toward the cavity, the movable mold is changed from the intermediate mold to the movable mold. A protruding block formed to protrude toward the surface, a groove formed by cutting out a side surface of the protruding block, and the intermediate block or the movable mold from which the protruding block protrudes. An engaging piece whose distal end engages with the groove, and a hydraulic cylinder that reciprocates the engaging piece, the groove being the movable die or the intermediate die serving as a base end of the protruding block Two side surfaces, a near side and a far side, and the far side surface is inclined, and the tip of the engagement piece is engaged while sliding on the far side surface. A die casting mold characterized by the above is provided.

  Preferably, the engaging piece includes a piston portion that reciprocates in conjunction with the hydraulic cylinder, and a tip portion that slides with a range defined on the tip of the piston portion.

  According to the present invention, the side surface on the far side with respect to the movable mold formed in the groove portion is inclined, and the tip of the engagement piece engages with this while the intermediate mold and the movable mold are in close contact with each other. It is joined while force is applied in the direction. Therefore, it is possible to provide a parting lock for preventing the intermediate mold and the movable mold from being separated when the molded product is taken out by using a mold having a three-sheet structure including a fixed mold, an intermediate mold, and a movable mold.

It is the schematic of the parting lock which the metal mold | die for die-casting concerning this invention has. It is the schematic for demonstrating operation | movement of the metal mold | die for die-casting which concerns on this invention. It is the schematic for demonstrating operation | movement of the metal mold | die for die-casting which concerns on this invention. It is the schematic for demonstrating operation | movement of the metal mold | die for die-casting which concerns on this invention.

  The die casting mold according to the present invention includes a parting lock 2 as shown in FIG. Before explaining the parting lock 2, an outline of the die casting mold 1 will be described with reference to FIGS. The die casting mold 1 has a three-piece structure, and includes a fixed mold 3, an intermediate mold 4, and a movable mold 5. The stationary mold 3 is immovable and is connected with a plunger 6 for providing molten metal. Specifically, a casting port 7 is formed as a connection port in the fixed mold 3, and a plunger 6 is inserted into the casting port 7. The intermediate mold 4 can be connected to and separated from the fixed mold 3, and the movable mold 5 can be connected to and separated from the intermediate mold 4. FIG. 2 shows a state in which the fixed mold 3, the intermediate mold 4, and the movable mold 5 are connected to each other.

  When the intermediate mold 4 and the movable mold 5 are connected, a cavity 8 is formed as a gap between the intermediate mold 4 and the movable mold 5. Thus, the intermediate mold 4 and the movable mold 5 are engraved with a predetermined shape so that a desired cavity 8 is formed when the intermediate mold 4 and the movable mold 5 are connected. A molten metal path 9 passing through the fixed mold 3 and the intermediate mold 4 is formed from the casting port 7 toward the cavity 8. Specifically, the molten metal path 9 is formed by a runner 10 formed in the fixed mold 3 and a pin gate 11 penetrating the intermediate mold 4. The molten metal path 9 passes from the casting port 7 through the runner 10 (through a flow divider when a flow divider for branching the runner 10 is formed as necessary), and communicates from the runner 10 to the pin gate 11. The pin gate 11 communicates with the cavity 8. Note that the illustrated pin gate 11 is of a type in which the molded product side (cavity 8 side) is thick.

  When performing die casting, the movable die 5 is moved in the direction of the fixed die 3 by a casting start signal. At this time, the intermediate mold 4 is moved together with the movable mold 5 and connected to each other. When the fixed mold 3, the intermediate mold 4, and the movable mold 5 are completely clamped, they are locked by the parting lock 2. When the molten metal supplied by the plunger 6 and filled in the cavity 8 is solidified, first, the movable die 5 is moved (separated) from the fixed die 3 together with the intermediate die 4. And it stops when it moved to the position set beforehand (position of Drawing 3). At this time, the molten metal in the middle of the molten metal path 9 is also solidified, and the runner portion 12 is exposed at a position corresponding to the runner 10 (strictly speaking, a portion corresponding to the current divider or the casting port 7). The biscuit corresponding to is also exposed, but will be collectively referred to as the runner portion 12 for convenience). The movable mold 5 and the intermediate mold 4 are moved to such a position that the runner portion 12 is exposed, and if it is about 100 mm, it is sufficiently exposed. A guide rail 13 protrudes from the fixed mold 3, and a hole (not shown) that can receive the guide rail 13 is provided in the intermediate mold 4. Therefore, the intermediate mold 4 moves in the connecting and separating directions with respect to the fixed mold 3 along the guide rail 13.

  Next, the runner portion 12 is cut and separated by a gate cutter (not shown). Thereby, the runner part 12 falls and is collected. This cutting and separation of the runner portion 12 is determined by the fall of the runner portion 12 by the phototube and the detection of the lower limit position of the cutter. Next, the movable mold 5 is further moved in order to take out the molded product. At this time, the lock by the parting lock 2 is released. The guide rail 13 has a pressing plate 14 at its end. By this presser plate 14, the movement range of the intermediate mold 4 is restricted. That is, when the intermediate mold 4 is moved together with the movable mold 5 so as to move away from the fixed mold 3, when the intermediate mold 4 reaches the position of the presser plate 14, the intermediate mold 4 is also fixed at this position. If the movable mold 5 is further separated in this state, the intermediate mold 4 and the movable mold 5 are separated from each other. When the movable mold 5 is separated from the intermediate mold 4, the molded product 15 is exposed. The movable mold 5 is moved until the molded product 15 can be taken out (position in FIG. 4). In this state, the molded product 15 is taken out by holding the pin gate portion 16 formed at a position corresponding to the pin gate 11. Thereafter, the pin gate portion 16 is removed from the molded product 15 to complete the product.

  The mold having such a three-piece structure has an advantage that the degree of freedom of the pouring gate is increased because the pouring gate can be installed inside the product, which is effective for products in which no pouring gate can be installed on the outer periphery. Furthermore, there is an advantage that the heat balance is improved, the strain is reduced, and the dimensions are stabilized. Furthermore, there is an advantage that the filling distance is shortened (concentric), and the poor hot water is reduced even with a thin wall. Furthermore, there is an advantage that a spout can be installed in the thick part inside the product and it is easy to prevent the occurrence of sink marks. In addition, since a plurality of gates can be installed, it is possible to make the quality of one type of multi-piece product the same. In addition, since the slide core can be easily installed, there is an advantage that the degree of freedom of mold design is expanded.

  As described above, the parting lock 2 is locked and unlocked when the molds are connected and separated. As shown in FIG. 1, the parting lock 2 is formed across the intermediate mold 4 and the movable mold 5. Specifically, the parting lock 2 includes a projecting block 17 that projects from the movable mold 5 toward the intermediate mold 4. That is, the intermediate mold 4 is provided with a space capable of receiving the protruding block 17, and the protruding block 17 is accommodated in this space (when the intermediate mold 4 and the movable mold 5 are connected). The protruding block 17 may have a columnar shape or a long rectangular parallelepiped shape. A side surface of the projecting block 17 is notched and a groove portion 18 is formed. On the other hand, the intermediate mold 4 has an engagement piece 19 that can be inserted through the inside thereof. The engagement piece 19 extends from the outside of the intermediate mold 4 through the inside of the intermediate mold 4 toward the protruding block 17.

  When the intermediate mold 4 and the movable mold 5 are connected, the tip of the engagement piece 19 is engaged with the groove 18. Thus, the state in which the engagement piece 19 is engaged with the groove portion 18 is the locked state. In the unlocked state, the tip of the engagement piece 19 is separated from the groove 18. The reciprocation of the engagement piece 19 is performed by the hydraulic cylinder 20. In the locked state, the positional relationship between the intermediate mold 4 and the movable mold 5 (engagement piece 19, more specifically, the position of a piston portion 19a described later) is stored in advance in a computer or the like, so that the deviation can be prevented. If there is, it is possible to detect a malfunction of the hydraulic cylinder 20 or wear of the engagement piece 19 or the groove 18.

  The groove portion 18 has two side surfaces that are closer to and farther from the movable die 5. In particular, the far side surface 18a is inclined. Specifically, the side surface 18 a has a gradient such that the distance between the side surfaces increases as it goes above the groove portion 18. The tip of the engagement piece 19 is also shaped to match the inclination of the side surface 18a. When the engagement piece 19 is inserted into the groove 18, the tip of the engagement piece 19 is engaged while sliding on the side surface 18 a on the far side of the groove 18. For this reason, the protruding block 17 is pulled toward the intermediate mold 4 side. As a result, when the parting lock 2 is locked, the movable die 5 is pulled toward the intermediate die 4 and the mutual connection is strengthened. Thereby, the intermediate mold 4 and the movable mold 5 are joined together while a force is applied in a direction in which they are in close contact with each other. Therefore, the mold having a three-sheet structure including the fixed mold 3, the intermediate mold 4, and the movable mold 5 can prevent the intermediate mold 4 and the movable mold 5 from separating when the molded product is taken out. The relationship between the protruding block 17 and the engagement piece 19 is not limited to the above shape, and many shapes and mechanisms such as a clamp type, a wedge type, and a pin bush type can be applied as a basic structure.

  On the other hand, when the parting lock 2 is unlocked, it is not automatically released when the force when moving the movable mold 5 and moving away from the intermediate mold 4 exceeds the locking force in the subsequent process, It is preferable to unlock by detecting the molding process and the position of the intermediate mold 4 and releasing the hydraulic pressure by a signal or artificially.

  At the time of unlocking, the attractive force between the intermediate die 4 and the movable die 5 is often more than the locking force (because the locking was performed after the mold was clamped). In order to cope with this, the engagement piece 19 is formed by a piston portion 19a that reciprocates in conjunction with the hydraulic cylinder 20, and a tip portion 19b that slides with a range defined at the tip of the piston portion 19a. Is preferred. The tip end portion 19b has a specified sliding range (S portion indicated by an arrow in FIG. 1), and when the tip portion 19b reaches the limit position, the force is directly transmitted to the piston portion 19a. That is, no force is applied to the tip 19b while the piston 19a slides in the range S. By providing such a tip portion 19b, when a force is applied in the direction in which the piston portion 19a is pulled out from the groove portion 18 by the hydraulic cylinder 20, the piston portion 19a first moves in the pulling direction without receiving any resistance. . At this time, the distal end portion 19b is relatively moved to the distal end side of the engagement piece 19. When the tip 19b reaches the tip position to the limit, the pulling force of the piston 19a is directly transmitted to the tip 19b, and the engagement piece 19 is pulled out from the groove 18. When the intermediate mold 4 and the movable mold 5 are in close contact with each other through a casting process, the engaging force between the tip 19b and the side surface 18a is also in close contact with the relatively strong force. Rather than pulling this out from the beginning with the force of the hydraulic cylinder 20, by forming a stroke in which the piston portion 19a moves within the range S as described above, the piston portion 19a can be vigorously shocked. Can be pulled out. Thereby, unlocking can be ensured.

  The molding method of the mold 1 of the present invention is not limited to die casting (the die casting method usually includes GF method, high vacuum, squeeze, and PF method). The molten metal material is aluminum, magnesium, or zinc. Resin may be used. In the above example, the movable block has the base end of the protruding block 17, the protruding block 17 protrudes toward the intermediate mold 4, and the engagement piece 19, the hydraulic cylinder 20, etc. are formed in the intermediate mold 4. However, the present invention has the same effect even when the intermediate mold 4 and the movable mold 5 are reversed. That is, the intermediate mold 4 may have the base end of the protruding block 17, the protruding block 17 may protrude toward the movable mold 5, and the engagement piece 19, the hydraulic cylinder 20, and the like may be formed on the movable mold 5.

1: die casting mold, 2: parting lock, 3: fixed mold, 4: intermediate mold, 5: movable mold, 6: plunger, 7: casting port, 8: cavity, 9: molten metal path, 10: runner 11: Pin gate, 12: Runner part, 13: Guide rail, 14: Presser plate, 15: Molded product, 16: Pin gate part, 17: Protruding block, 18: Groove part, 18a: Side of the groove part far from the movable mold 19: engagement piece, 19a: piston part, 19b: tip part, 20: hydraulic cylinder

Claims (2)

A fixed mold to be connected with a plunger providing molten metal;
An intermediate mold connected to and spaced from the fixed mold;
A movable mold connected to and separated from the intermediate mold;
A cavity formed as a gap between the intermediate mold and the movable mold when the intermediate mold and the movable mold are connected;
A casting port formed in the fixed mold as a connection port of the plunger;
In a die casting mold provided with a molten metal path passing through the fixed mold and the intermediate mold from the casting port toward the cavity,
A projecting block formed to project from the movable mold to the intermediate mold, or from the intermediate mold to the movable mold;
A groove formed by cutting out the side surface of the protruding block;
An engagement piece disposed in the intermediate mold or the movable mold from which the projecting block is projected, extending toward the projecting block and having a tip engaged with the groove;
A hydraulic cylinder for reciprocating the engagement piece,
The groove portion has two side surfaces near and far from the movable mold or the intermediate mold, which are the base ends of the protruding blocks, and the side surfaces of the far side are formed to be inclined, and the engagement The die-casting die, wherein the tip of the piece is engaged while sliding on the side surface on the far side.   The said engagement piece consists of a piston part which reciprocates in conjunction with the said hydraulic cylinder, and a front-end | tip part which the range defines the front-end | tip of this piston part, and slides. Die casting mold.

Images