JP2007014988A - Die-casting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a die-casting apparatus capable of suppressing the deformation of a die without fbeing made large in size. <P>SOLUTION: The die-casting apparatus is provided with one pair of platens 20, 22, the dies 21, 23, a sleeve 37, a cylinder 30, a plurality of tie rods 52, and a supporting member 32. The dies 21, 23, in which a cavity 25 is formed in their inner part, have a gate 26 communicating the cavity 25 with the outer part. The sleeve 37 is communicated with the cavity 25 through the gate 26. The cylinder 30 elongates and contracts a plunger rod, in which a plunger tip 40 sliding in the sleeve 37 is fitted to its top end, from/to another side of the platen 20. A plurality pieces of die rods 52 connect one of the platen 20 to the cylinder. The supporting member 32 supports the cylinder 30 so as to be slidable in the elongating/contracting direction of the plunger rod. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a die casting apparatus. In detail, it is related with the technique which suppresses a deformation | transformation of a metal mold | die.

2. Description of the Related Art A die casting apparatus including a pair of platens, a mold, a sleeve, and a cylinder is known. The mold is divided and fixed to each platen, and when a pair of platens are closed close to each other, a cavity is formed inside, and a gate that communicates the cavity with the outside is provided. The sleeve is fixed to one platen and communicates with the cavity via the gate. The cylinder expands and contracts with respect to one platen a plunger rod having a plunger tip that slides in the sleeve attached to the tip.
When the plunger rod extends, the plunger tip advances toward the mold. As the plunger tip advances, the molten metal contained in the sleeve passes through the gate of the mold and is injected into the cavity. The injected molten metal is cooled in the cavity and solidified to form a molded product.
The cylinder advances the plunger tip vigorously through the plunger rod when injecting molten metal into the cavity of the mold. Therefore, when the molten metal is injected, a large reaction force (hereinafter referred to as “injection reaction force”) acts between one platen and the cylinder. When one platen is deformed by the injection reaction force, the mold is deformed accordingly. If the mold is deformed, the molded product cannot be accurately molded.
Patent Document 1 discloses a technique in which one platen is fixed in a horizontal state on a machine base, and a cylinder is vertically arranged in a pit dug down from the machine base. The lower end of the cylinder is attached to the bottom surface of the pit. By firmly restraining one of the platen and the cylinder, the injection reaction force is received and deformation of one of the platens is suppressed. When deformation of one platen is suppressed, deformation of the mold is also suppressed.

JP-A-4-262848

However, as in the technique disclosed in Patent Document 1, the strength of the die casting apparatus must be sufficiently high to provide a machine base and pits to receive the injection reaction force and thereby suppress the deformation of the mold. I must. If the strength of the die-casting device is insufficient, a supporting part that supports one platen and the cylinder (for example, a base for fixing the one platen and the cylinder. In Patent Document 1, it corresponds to the machine base and the peripheral structure of the pit. Is deformed. When one platen and the support portion of the cylinder are deformed, one platen is greatly deformed accordingly. The die-casting device becomes large when trying to receive the injection reaction force by increasing the strength.
The present invention has been made to solve the problem, and realizes a die casting apparatus capable of suppressing deformation of a mold without increasing the size.

The die casting apparatus of the present invention includes a pair of platens, a mold, a sleeve, a cylinder, a plurality of tie rods, and a support member. The mold is divided and fixed to each platen, and when a pair of platens are closed close to each other, a cavity is formed inside, and a gate that communicates the cavity with the outside is provided. The sleeve is fixed to one platen and communicates with the cavity via the gate. The cylinder expands and contracts with respect to one platen a plunger rod having a plunger tip that slides in the sleeve attached to the tip. The plurality of tie rods extend in the expansion / contraction direction of the plunger rod, connect one platen and the cylinder, and are arranged around the plunger rod. The support member supports the cylinder so as to be slidable in the expansion / contraction direction of the plunger rod with respect to one platen.
The tie rod of this die casting device extends when an injection reaction force acts. The cylinder slides to the opposite side of the platen as much as the tie rod extends. Even if the injection reaction force acts on one platen via the tie rod, the deformation is suppressed. This is because one platen and the support portion of the cylinder do not deform when the cylinder slides. Therefore, the deformation of the mold can be suppressed without increasing the size of the die casting apparatus.

In the above die casting apparatus, it is preferable that the plurality of tie rods are arranged at substantially equal intervals along a circumferential direction of a circle centering on the axis of the plunger rod.
If comprised in this way, an injection reaction force will be transmitted to one platen in the state equally distributed to each tie rod. Therefore, one platen does not deform in a complicated manner. Therefore, deformation of the mold is further suppressed.

  In the die casting apparatus of the present invention, a plurality of tie rods arranged around the plunger rod connect one platen and the cylinder, and a support member supports the cylinder so as to be slidable in the expansion and contraction direction of the plunger rod. Yes. For this reason, the die-casting apparatus which can suppress a deformation | transformation of a metal mold | die without enlarging can be implement | achieved.

The main features of the embodiments described later will be described.
(1) The die casting apparatus includes a mold part, a base, a sleeve, an injection part, and a pair of tie rods.
(2) A mold part, a fixed platen, a fixed mold, a movable mold, and a movable platen are provided. The stationary mold is attached to the stationary platen. The movable mold is attached to the movable platen. A cavity is formed by the fixed mold and the movable mold. The sleeve communicates with the cavity through a gate provided in the stationary mold while penetrating the stationary platen.
(3) The injection unit includes a support member, a base member, an injection cylinder, and a plunger tip. The support member is fixed to the base. The support member is attached to the support member so as to be movable in the horizontal direction. The injection cylinder has a cylinder body, a plunger rod, and a cylinder plate. The cylinder body is fixed to the support member. The cylinder plate is fixed to the end of the cylinder body. The plunger rod extends and contracts from the cylinder body. The plunger tip is attached to the tip of the plunger rod. The sleeve slidably guides the plunger tip. The plunger tip can swing around the swing center while being attached to the tip of the plunger rod. The center of gravity of the plunger tip is located closer to the injection cylinder than the swing center.
(4) The tie rod connects the fixed platen and the cylinder plate of the injection cylinder. The axis of the tie rod extends in the same direction as the axis of the plunger rod, and is arranged at equal intervals along the circumferential direction of a circle centered on the axis of the plunger rod.

An embodiment according to the die casting apparatus of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the die casting apparatus 10 includes a base 11, a mold part 12, a sleeve 37, an injection part 14, and a pair of tie rods 52.
As shown in FIGS. 2 and 3, the mold part 12 includes a fixed platen 20, a fixed mold 21, a movable mold 23, a movable platen 22, and four tie bars 24. The fixed platen 20 is fixed to the base 11. The fixed mold 21 is attached to the fixed platen 20. The movable mold 23 is attached to the movable platen 22. The movable platen 22 is supported by an opening / closing mechanism (not shown), and can move on the base 11 in the horizontal direction. The tie bar 24 connects the fixed platen 20 and the movable platen, and guides the horizontal movement of the movable platen 22. The movable platen 22 is driven by an opening / closing mechanism and moves between a mold clamping position approaching the fixed platen 20 and a mold opening position separated from the fixed platen 20. 2 and 3 show a state in which the movable platen 22 is disposed at the mold clamping position.
When the movable platen 22 is arranged at the mold clamping position, the fixed mold 21 and the movable mold 23 form a cavity 25 for casting product molding. When the movable platen 22 is disposed at the mold opening position, the fixed mold 21 and the movable mold 23 are opened (separated), and the cast product molded in the cavity 25 can be taken out.
The sleeve 37 is formed in a cylindrical shape and penetrates the fixed platen 20. The inside of the sleeve 30 and the cavity 25 communicate with each other via a gate 26 provided in the fixed mold 21.

The injection unit 14 includes a support member 32, a base member 33, an injection cylinder 30, and a plunger chip 40.
The support member 32 is fixed to the base 11. As shown in FIG. 4, the lower end portion 34 of the base member 33 can be moved in the horizontal direction and is attached to the support member 32 in a state where movement in the vertical direction is constrained.
As shown in FIGS. 2 and 3, the injection cylinder 30 has a cylinder body 35, a plunger rod 31, and a cylinder plate 38. The cylinder body 35 is fixed to the base member 33 and incorporates a piston (not shown). The plunger rod 31 is fixed to the piston. The cylinder plate 38 is fixed to the end of the cylinder body 35 on the mold part 12 side. The cylinder body 35 is supplied with hydraulic pressure, and the piston moves within the cylinder body 35 by switching between applying the hydraulic pressure to one side or the other side of the piston. As the piston moves, the plunger rod 31 expands and contracts. 2 and 3 show the plunger rod 31 in a contracted state. The plunger tip 40 is inserted into the sleeve 37 in a state of being attached to the distal end portion 41 of the plunger rod 31.

As shown in FIG. 5, the distal end portion 41 of the plunger rod 31 is formed in a substantially spherical shape. The tip portion 41 and the rod main body 42 are formed with a through hole 48 penetrating them. The plunger tip 40 is formed with a substantially hemispherical recess 43. The distal end portion 41 of the plunger rod 31 enters the recess 43. A ring-shaped member 44 is fixed in the plunger tip 40 by a plurality of bolts 45. A portion 46 that is a part of the inner peripheral surface of the ring-shaped member 44 is in sliding contact with the tip portion 41. The plunger tip 40 can swing around the swing center 50 in a state where the plunger tip 40 is attached to the distal end portion 41 of the plunger rod 31 (can swing the neck).
The plunger tip 40 is formed with a cooling hole 64 communicating with the through hole 48 of the plunger rod 31. A cooling forward pipe and a cooling return pipe (not shown) pass through the through hole 48 and the cooling hole 64. The coolant fed from the cooling source to the plunger tip 40 via the cooling forward piping flows through a cooling passage (not shown) to cool the plunger tip 40 and then to the cooling source via the cooling return piping. Return.

As shown in FIG. 5, the center of gravity 63 of the plunger tip 40 is located closer to the injection cylinder 30 than the swing center 50.
As shown in FIGS. 1 and 3, the tie rod 52 connects the fixed platen 20 and the cylinder plate 38 of the injection cylinder 30. The axis of the tie rod 52 extends in the same direction as the axis of the sleeve 37 and is disposed at a symmetrical position with respect to the axis of the plunger rod 31 (along the circumferential direction of a circle centered on the axis of the plunger rod 31). And can be regarded as being equally spaced).

  As shown in FIGS. 2 and 3, when a cast product is formed by the die casting apparatus 10, the molten metal 54 is supplied into the sleeve 37 via a supply runner (not shown). After supplying the molten metal 54 into the sleeve 37, the plunger rod 31 of the injection cylinder 30 is rapidly extended. When the plunger rod 31 extends, the plunger tip 40 moves forward to the stationary mold 21 side. The plunger tip 40 that moves forward fills the cavity 25 with the molten metal 54 via the gate 26 of the fixed mold 21. 6 and 7 illustrate a state in which the cavity 25 is filled with the molten metal 54. The molten metal 54 filled in the cavity 25 is cooled by the coolant passing through the cooling flow paths (not shown) of the molds 21 and 23. The cooled molten metal 54 is solidified. After the molten metal 54 has solidified, the movable platen 22 is moved to the mold opening position, and the cast product is taken out from the die casting apparatus 10.

When filling the cavity 25 with the molten metal 54, the plunger tip 40 moves forward together with the plunger rod 31, and strongly pushes the molten metal 54 into the narrow gate 26. For this reason, a large injection reaction force (for example, 800 tons) that separates the mold portion 12 and the injection cylinder 30 from each other acts. When the injection reaction force acts, the tie rod 52 extends. When the tie rod extends, the base member 33 slides with respect to the support member 32, and at the same time, the injection cylinder 30 moves in a direction away from the mold part 12. When the filling of the molten metal 54 into the cavity 25 is completed, the injection reaction force does not act and the tie rod 52 contracts, whereby the injection cylinder 30 returns to its original position.
On the other hand, when the injection part 14 is fixed to the base 11, the cylinder plate 38, the cylinder body 35, the base member 33, and the base 11 are greatly deformed by the injection reaction force. The fixed platen 20 is also deformed by an injection reaction force acting on itself, but is deformed greatly and complicatedly by the influence of the deformation of the cylinder plate 38, the cylinder body 35, the base member 33, and the base 11. When the fixed platen 20 is deformed, the molds 21 and 23 are also deformed. When the molds 21 and 23 are deformed, the cast product may not be formed into a desired shape, or a gap may be formed between the molds 21 and 23. When a gap is formed between the molds 21 and 22, the molten metal 54 leaks to the outside.
However, if the rigidity of each part is increased so that the deformation due to the injection reaction force is reduced, the die casting machine becomes enormous.

In the die casting apparatus 10 of the present embodiment, the injection cylinder 30 moves as the tie rod 52 extends due to the injection reaction force. As already described, the axis of the tie rod 52 extends in the same direction as the axis of the plunger rod 31 and is arranged symmetrically with respect to the axis of the plunger rod 31. For this reason, only the force that is in the axial direction of the tie rod 52 and symmetric with respect to the axis of the plunger rod 31 acts on the fixed platen 20. Since only a force symmetric with respect to the axis of the plunger rod 31 acts, the fixed platen does not deform greatly and complicatedly. That is, the deformation of the fixed platen 20 is suppressed. When the deformation of the fixed platen 20 is suppressed, the deformation of the molds 21 and 22 is also suppressed. Therefore, the product accuracy of the cast product is improved and the molten metal 54 is prevented from leaking outside the molds 21 and 23.
Three or more tie rods 52 can be provided. In that case, the tie rods 52 are arranged at substantially equal intervals around the axis of the plunger rod 31. With this configuration, a resultant force of the forces acting in the axial direction of each tie rod 52, that is, a force equal to the injection reaction force, acts on the fixed platen 20 around the axis of the plunger rod 31. For this reason, it is possible to suppress the fixed platen 20 from being deformed in a complicated manner.

  As already described, in the die casting apparatus 10 of the present embodiment, the center of gravity 63 of the plunger tip 40 is located on the injection cylinder 30 side with respect to the swing center 50 of the plunger tip 40. For this reason, when the plunger rod 31 extends, a moment for making the axis of the plunger tip 40 and the axis of the sleeve 37 more parallel acts on the plunger tip 40. That is, by positioning the center of gravity 63 of the plunger tip 40 closer to the injection cylinder 30 than the swing center 50 of the plunger tip 40, the axis of the plunger tip 40 and the axis of the sleeve 37 are actively brought close to parallel. For this reason, the inner surface 57 of the sleeve 37 and the side surface 58 of the plunger tip 40 slide in a state where the surfaces are stable. For this reason, the wear of the sleeve 37 and the plunger tip 40 is suppressed, and their life is prolonged. Further, since the plunger tip 40 is prevented from being squeezed on the inner surface of the sleeve 37, the injection reaction force is reduced.

  On the other hand, as shown in FIG. 8, when the center of gravity 63 of the plunger tip 40 is located on the reflection cylinder 30 side of the swing center 50 of the plunger tip 40, the plunger rod 31 extends and the plunger When the tip 40 moves forward, a moment is applied to rotate the plunger tip 40 so that the axis of the plunger tip 40 is inclined with respect to the axis of the sleeve 37. Therefore, as shown in part A, the corners of the plunger tip 40 are pressed against the inner surface 57 of the sleeve 37, and the plunger tip 40 squeezes the sleeve inner surface 57. For this reason, the plunger tip 40 and the sleeve 37 are worn, and their lifetime is shortened. Further, if the plunger tip 40 squeezes the inner surface 57 of the sleeve 37, the injection reaction force also increases.

  Even if the center of gravity of the plunger tip 40 is made to coincide with the center of gravity, it is actually difficult to make the center of oscillation coincide with the center of gravity due to manufacturing errors or thermal deformation of the plunger tip 40, the plunger rod 31, etc. . If the center of gravity of the plunger tip 40 does not coincide with the center of gravity, and the center of gravity 63 of the plunger tip 40 is positioned on the reflecting cylinder 30 side of the center of swing 50, when the plunger tip 40 moves forward, FIG. As a result, the plunger tip 40 and the sleeve 37 are worn and the injection reaction force is increased.

  The swing center of the plunger tip 40 can be positioned closer to the gate than the position that divides the axial length into two. If comprised in this way, when the plunger tip 40 advances, the axis | shaft of the plunger tip 40 and the axis | shaft of the sleeve 37 will be arrange | positioned more in parallel. Therefore, wear of the plunger tip 40 and the sleeve 37 is suppressed.

  Even if the plunger tip 40 is mounted so as not to swing with respect to the plunger rod 31, the center of gravity 63 of the plunger tip 40 is positioned closer to the reflecting cylinder 30 than the swing center 50 of the plunger tip 40, or the plunger tip It is effective to suppress the wear of the plunger tip 40 and the sleeve 37 by positioning the swing center of 40 on the gate side from the position that divides the axial length into two. This is because the plunger tip 40 and the sleeve 37 are arranged more in parallel by the deformation of the plunger tip 40 and the plunger rod 31.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
In addition, the technical elements described in the present specification or drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

The typical perspective view of a die-casting apparatus. The longitudinal cross-sectional view of a die-cast apparatus. The horizontal fragmentary sectional view of a die-casting apparatus. Sectional drawing of a base, a supporting member, and a base member. Sectional drawing of the state in which the plunger tip was mounted | worn with the plunger rod. The longitudinal cross-sectional view of a die-cast apparatus. The horizontal fragmentary sectional view of a die-casting apparatus. A typical sectional view of a sleeve, a plunger tip, and a plunger rod.

Explanation of symbols

10: Die casting apparatus 11: Base 12: Mold part 14: Injection part 20: Fixed platen 21: Fixed mold 22: Movable platen 23: Movable mold 24: Tie bar 25: Cavity 26: Gate 30: Injection cylinder 31: Plunger rod 32: Support member 33: Base member 34: Lower end 35: Cylinder body 37: Sleeve 38: Cylinder plate 40: Plunger tip 42: Rod body 43: Recess 44: Ring member 46: Part 48: Through hole 50: Oscillation center 52: Tie rod 54: Molten metal 63: Center of gravity 64: Cooling hole

Claims (2)

A pair of platens;
Each platen is divided and fixed, and when a pair of platens approach and are closed, a cavity is formed inside, and a mold having a gate communicating with the cavity and the outside,
A sleeve fixed to one platen and communicating with the cavity via a gate;
A cylinder that expands and contracts a plunger rod attached to the tip of a plunger tip that slides in the sleeve with respect to one platen;
A plurality of tie rods extending in the expansion / contraction direction of the plunger rod, connecting one platen and the cylinder, and arranged around the plunger rod;
A die casting apparatus comprising: a support member that supports a cylinder so as to be slidable in the expansion and contraction direction of the plunger rod with respect to the one platen.   2. The die casting apparatus according to claim 1, wherein the plurality of tie rods are arranged at substantially equal intervals along a circumferential direction of a circle centered on the axis of the plunger rod.

Images