JP2003010957A - Structure of gate made of ceramics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a shrinkage cavity in a casting by directional solidification. SOLUTION: The ceramic made gate is provided with a stationary mold held on a stationary board, and a movable mold movable in the attaching/ detaching direction against the stationary mold. The stationary mold is provided with a stationary side main mold constituting a body of the mold, and a stationary mold side core fittingly inserted in the main mold to constitute a cavity on the stationary mold side. The movable mold is provided with a movable side core fittingly inserted in the main mold constituting the body of the mold and the main mold to constitute the cavity part on the movable mold. On a runner positioning on the lower part of the both cores, and a position facing a gate part connecting the runner part and the cavity part, a core for fitting is inserted, and in the core for fitting, a ceramic made piece is fittingly inserted so as to constitute a part of the gate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic gate structure for a die casting machine.

[0002]

2. Description of the Related Art When casting aluminum melt or magnesium melt into a cavity using a casting machine such as a die casting machine, the gate area and runner should be set so that the pushing water works sufficiently until the solidification of the product part of the cavity part is completed. By increasing the size of the part, solidification was directional solidification that continuously progressed from the casting part to the runner part.

[0003]

However, even if an attempt is made to cut between the product portion and the biscuit portion, the cross-sectional area in the vicinity of the gate portion of the runner portion becomes large, which makes cutting (trimming) difficult. Furthermore, in the case of a cast product in which the area near the gate of the runner cannot be enlarged, the area near the gate solidifies first, and the cavity and biscuit area solidify last, which results in directional solidification. However, there is a problem that shrinkage cavities occur inside the cast product.

[0004]

In order to solve the above problems, in the first aspect of the present invention, a fixed mold held by a fixed plate and movable in the contact and separation directions with respect to the fixed mold. A movable mold held by a movable plate, the fixed mold constituting a main body of the mold, and a fixed-side main mold and a cavity part on the fixed mold side inserted into the main mold. And a movable side mold forming a cavity part on the side of the movable mold by being inserted into the main mold and the movable mold. And a runner portion located at a lower portion of both the nests, and a fitting nest mounted at a position facing the gate portion connecting the runner portion and the cavity portion, and a ceramic piece is fitted into the fitting nest to insert the ceramic piece into the gate portion. To form part of. Further, in the second invention mainly based on the first invention, the opening portion of the gate portion is surrounded by a ceramic piece for the majority of the wetted side length, and the rest is constituted by the fitting nest. I did it.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of a ceramic gate structure according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an overall longitudinal sectional view showing the present invention, FIG. 2 is a sectional view taken along the line A--A of FIG. 1, FIG. 3 is an example of a ceramic piece structure, and FIG. 4 is a ceramic piece inserted. The perspective view of the nest | insert for time fitting is shown.

This die casting machine is mainly composed of a die unit 10 and a casting unit 12. The mold device 10 includes a fixed mold 16 held by a fixed platen 14 and a movable mold 20 held by a movable platen 18. A column 24 is connected to the fixed platen 14 via a nut 22, and the movable platen 18 is movable along the column 24 in a direction toward and away from the fixed platen 14 by a toggle mechanism (not shown). Has been done. Further, the fixed mold 16 is composed of a main mold 16a that constitutes the main body of the mold and a nest 100a that is fitted and inserted into the main mold 16a, and the movable mold 20 is also similar to the fixed mold 16. The main mold 20a and the nest 100b have the same structure.

The main molds 16a and 20a are provided with recesses 102a for inserting the inserts 100a and 100b, respectively.
102b is provided in which the two nests 100a, 10a
0b is installed. The cavity portion 26, the gate portion 27, and the runner portion 2 are provided on the mating surface between the two nests 100a and 100b.
8 is engraved, and a biscuit portion 30 is engraved and communicated with the lower parts of the main molds 16a, 20a. Further, an enclosed space as shown in FIG. 1 is formed inside the movable mold 20, and an extruding plate 104 is movably arranged back and forth therein. Two or four return pins 106 are diagonally arranged on the push-out plate 104, a through hole is formed in the main mold 20a, and both molds 16,
When the mold 20 is closed, the tip of the return pin 106 comes into contact with the parting surface of the main mold 16a, and the tip of the return pin 106 is retracted to the same surface as the parting surface of the main mold 20a. It is like this.

Further, as shown in FIG.
In FIG. 4, a plurality of extruding pins 110 for pressing the cast product 108, which is a product, from the movable mold 20 side evenly to the cast product 108 to smoothly separate the cast product 108 from the cavity portion 26 are provided. (5 to 6 in this embodiment) are arranged. The mold device 10 is a machine base 44.
It is installed above, and the machine base 44 is installed so as to straddle a pit 48 recessed in the ground base 46.

The pouring device 12 is installed in the pit 48. The casting device 12 has a configuration in which an injection cylinder 50, a block 52, and a sleeve 54 are sequentially installed from the lower side. The injection cylinder 50 is supported by a receiving seat 56 fixed to the bottom surface of the pit 48 via a pin 58, and the upper end side of the injection cylinder 50 is tiltable about the pin 58 as a rotation center. A piston 60 is installed in the injection cylinder 50, and a rod 6 extending upward is provided in the piston 60.
Two are connected.

A cylinder hole 64 extending in the vertical direction is provided in the block 52, a docking ram 66 is inserted into the cylinder hole 64, and the lower end of the docking ram 66 is formed on the upper surface of the injection cylinder 50. Flange 6
It is fixed to 8. The sleeve 54 is connected to the upper side of the block 52 via a connecting member 69, and the upper end of the sleeve 54 can be inserted into the lower end of the biscuit portion 30 of the mold device 10.

The plunger tip 7 is placed in the sleeve 54.
0 is installed slidably, and the plunger tip 7
The lower end of the plunger 72 holding 0 is connected to the upper end of the rod 62 via a coupling 73. A tilting cylinder 74 is pivotally supported by a side wall of the pit 48 via a seat 76 and a pin 78, and a rod 82 connected to a piston 80 of the tilting cylinder has a tip at a joint 84. It is pivotally attached to the side surface of the flange 68 of the injection cylinder 50 via a pin 86.

Next, the ceramic gate structure of the present invention will be described. First, the gate portion 27 is disposed on the upper end portion of the runner portion 28 which is in the shape of a final drawing, and is composed of a pair of opposing ceramic pieces 114a and 114b. As shown in FIG. 2, the wetted side length of the opening of the gate portion 27 is mostly (for example, this gate portion 2).
7 about 70 to 90% of the wetted side length of the whole) is occupied by the ceramic pieces 114a and 114b, and the remaining 10 to 30
The fitting inserts 150a and 150b occupy the percentage.

Here, the ceramic piece 114a,
As the material of 114b, for example, titanium metax (trade name), which has excellent melting resistance against an aluminum alloy, and has low thermal conductivity and excellent heat retention of the molten metal,
It is suitable. The main characteristics are as follows. Density 4.34 or 5.32 (g / cm2) Specific heat 0.11 or 0.13 (cal / g · ° C) Thermal conductivity 0.0177 or 0.0255 (cal / cm · sec · ° C) Thermal expansion coefficient 7.3 or 8.0 (× 10 ^-6 ) Young's modulus 12,400 or 11,300 (kgf / mm2)

Since the pair of pieces 114a and 114b forming the gate portion 27 are vertically symmetrical about the rectangular gate portion 27,
A detailed description will be given on behalf of the movable mold 16 in which the ceramic piece 114a arranged in the upper part is arranged.

A main mold 20a constituting the movable mold 20 and a lower side of the main mold 20a are engraved and a fitting insert 1 is inserted therein.
It has a configuration in which 50a is inserted. Further, the main mold 16a that constitutes one of the fixed molds 16 and the lower side of the main mold 16a are carved into a substantially rectangular shape (or may be a square shape) in a plan view, and the fitting insert 150a is inserted therein. Make up the composition. The ceramic piece 114a described above is fitted and inserted in the fitting insert 150a. A cooling passage is provided inside the insert 100a, and a cooling passage is also provided in the fitting insert 150a, so that cooling water can be passed from the outside through the main mold 16a. .

The ceramic piece 114a has a T-shape in plan view, and the base 1 corresponding to the head of the T-shape.
16a and the base 11 of the portion corresponding to the vertical center axis of the T-shape
And 8a. In particular, the ceramic piece 114a includes a fitting insert 15 as shown in FIG.
0a, the molten metal injected into the cavity 26 is expanded by sensible heat, and the insert 100a and the insert 1 are inserted.
It is contracted by the cooling water introduced into the cooling passage provided in 50a. When the temperature of the fitting insert 150a rises, the ceramic piece 114a has a smaller coefficient of thermal expansion than the fitting insert 150a, so the ceramic piece 114a comes off and falls off. According to the invention, the base portion 116a of the ceramic piece 114a is the fitting insert 1.
The structure is such that it is locked by 50a and does not fall off.

Next, reference numeral 210a indicates a gate surface portion constituting the gate portion 27 where the ceramic piece 114a and the piece 114b face each other. The gate surface portion 120a has various shapes. Is used. That is, as shown in FIG.
There are a semi-elliptical surface shape shown in (b), and a frustoconical surface shape engraved on a flat surface portion as shown in FIG. 3 (c).

The operation of the die casting machine using the ceramic gate structure thus configured will be described.

First, a pair of the ceramic pieces 114 constituting the desired gate portion 27 as shown in FIG.
After determining the combination of a and 114b, they are fitted into the fitting inserts 150a and 150b, respectively. Next, the fitting inserts 150a and 150b are mounted on the corresponding main molds 20a and 20b. After that, the fixed mold 16 and the movable mold 20 are matched with each other, and then the mold clamping is completed.

The operation of the casting device 12 is performed in parallel with a series of operations. That is, the block 52 descends by releasing the hydraulic oil supplied into the cylinder hole 64,
It is in a state of being seated on the cylinder 50. Further, by releasing the hydraulic oil supplied to the head end side of the injection cylinder 50, the piston 60 descends to the lower limit and the plunger tip 70 also descends to the lower limit. When the rod 82 of the tilt cylinder 74 is projected in this state,
The pouring device 12 tilts as a whole. Therefore, the molten aluminum is poured into the sleeve 54.

Thereafter, the rod 82 of the tilting cylinder 74
And the casting device 12 is set in the vertical posture. Next, hydraulic oil is introduced into the cylinder hole 64 of the block 52 to cause the docking ram 66 to project. As a result, the block 52 rises, and the sleeve 54 is inserted into the biscuit portion 30 of the mold device 10. Therefore, the injection cylinder 50
Oil is introduced into the head end chamber of the
Push up. As a result, the plunger tip 70 rises and the molten aluminum stored in the sleeve 54 is introduced into the cavity portion 26 via the biscuit portion 30, the runner portion 28, and the gate portion 27, and the cast product having the desired directional solidification. 108 could be molded.

[0023]

As described above, by using the ceramic gate structure according to the present invention, (1) the gate structure of the runner portion can be made thin, and the product portion and the runner portion can be easily separated. . (2) When the product part and the runner part are separated, no large piece remains in the product part. (3) Even a cast product in which the vicinity of the gate of the runner portion is narrowed down, a good product having no shrinkage cavity defect can be obtained. (4) The volume of the runner portion can be reduced, and the amount of molten metal poured can be reduced. (5) In squeeze casting, it is possible to suppress the temperature drop when the molten metal passes near the gate of the runner,
It is possible to fill at a lower speed and prevent product defects due to air entrapment.

[Brief description of drawings]

FIG. 1 is an overall vertical sectional view showing the present invention.

FIG. 2 is a cross-sectional view as seen from AA in FIG.

FIG. 3 is an example of a piece structure made of ceramics.

FIG. 4 is a perspective view of a fitting insert for inserting a ceramic piece.

[Explanation of symbols]

10 Mold equipment 12 Casting device 14 Fixed board 16 Fixed mold 16a main mold 18 movable plate 20 movable mold 20a main mold 26 Cavity 27 Gate 28 Runner section 30 biscuit part 44 machine base 50 injection cylinders 52 blocks 54 sleeve 60 pistons 62 rod 64 cylinder holes 66 docking ram 69 Connection member 70 Plunger tip 72 Plunger 74 Tilt cylinder 84 joint 100 (a, b) nesting 102 (a, b) recess 104 Extruded plate 106 Return pin 108 casting 110 Extrusion pin 112 space 114 (a, b) Ceramic piece 116 (a, b) base 118 (a, b) stand 120 (a, b) Gate surface part 150 (a, b) Nest for fitting

Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B22D 27/04 B22D 27/04 A

Claims (2)

[Claims] 1. A fixed mold held by a fixed plate, and a movable mold held by a movable plate movable toward and away from the fixed mold, the fixed mold being a main body of the mold. A fixed side main mold forming a part and a fixed side nest inserted in the main mold to form a fixed mold side cavity, and the movable mold is movable to form a main part of the mold. A side main mold and a movable insert that is inserted into the main mold to form a cavity on the side of the movable mold. The runner parts located under the insert molds, the runner parts, and the cavity parts are provided. A gate structure made of ceramics, characterized in that a fitting insert is attached to a position facing the connecting gate part, and a ceramic piece is inserted into the fitting insert to form a part of the gate part. 2. The opening portion of the gate portion is such that most of the wetted side length is surrounded by a ceramic piece, and
The gate structure made of ceramics according to claim 1, characterized in that the rest is constituted by the fitting insert.