JPS63199059A - Die-casting apparatus - Google Patents

Abstract

PURPOSE:To produce crystal structure having no defect in a casting product by accommodating a piston as one body with sub-rod for pressurizing in a cylinder room formed in a main rod for pressurizing, making the sub-rod for pressurizing as movable in and out at the end of the main rod for pressurizing and acting effectively pressure by secondary pressurizing at the part positioning in front of the rod for pressurizing. CONSTITUTION:In a movable die 24, a hydraulic cylinder 56 for secondary pressurizing is supported and the main rood 60 for pressurizing as one body with a main piston 58 inserted in the hydraulic cylinder 56 can be advanced into a cavity A by penetrating the movable die 24. And, in the cylinder room 62 opening to the main piston 58 side of the main rod 60 for pressurizing, the piston 64 as one body with the sub-rod 66 for pressurizing is accommodate. After the main rod 60 for pressurizing of the hydraulic cylinder 56 for secondary pressurizing is pushed in the molten metal in the cavity A, the solidification around the main rod 60 for pressurizing is progressed and further after stopping the main rod 60 for pressurizing, the sub-rod 66 for pressurizing is advanced and extended from the end of the main rod 60 for pressurizing and the sufficient pressure by the secondary pressurizing is acted to the non-solidified molten metal positioning in front of the end part of the main rod 60 for pressurizing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a type of die casting in which secondary pressure is not applied to the melt filled in the mold cavity.

In the pressure die-casting method (simply called the die-casting method) in which molten metal is cast under high pressure, cavities occur inside the V and the crystal structure becomes coarser, causing the thick part to become coarser. There was a tendency for the strength to be low 1. In order to solve this problem, a method has been proposed in which the cavity of the mold is filled with molten metal under pressure and a secondary pressure is applied to the molten metal in the cavity before the molten metal solidifies (for example, (Japanese Patent Publication No. Sho/Ifl-7570, Japanese Patent Publication No. 49-36093).

The main structure of the mold used in this method is, for example, as shown in FIG. 01 is a mold, and the mold 01
A pressurizing rod 02, which is driven forward and backward by a secondary pressurizing device, is movably inserted into the opening formed in the opening.

This pressure rod 02 is connected to the melt '6 filled in the pipe 17A.
It is pushed forward into the melt 403 and applies a secondary pressurizing pressure to the melt 403 before solidification.

However, since the solidification of the molten metal 03 proceeds rapidly from the peripheral wall of the cavity A, and the central part solidifies last, especially when the pressurizing rod is pushed into a large depth, the pressurizing rod 02 is moved forward. The 03A part around the rod is solidified, and defects (wrinkles, etc.) occur in the solidified fabric due to excessive shear stress, while the unsolidified 03[3
The secondary pressurizing force does not act on the 033 part, blowholes are formed in the 033 part, and the crystal structure tends to be undesirably densified.

8 4° D. The object of the present invention is to fill the cavity of a mold with molten metal,
Before the molten metal solidifies, when the pressurizing rod is advanced into the girevity to apply the secondary force 11:F+ force to the molten metal, the pressure rod is positioned in front of the pressurizing rod to prevent excessive pressure on the solidified tissue. A secondary pressurizing pressure is also applied to the part where the material is to be woven, thereby creating a tR product with a sound II weave structure (located at point 7).

The purpose is to incorporate at least one wooden 01 pressure rod that retracts and retracts from the tip of the main pressure rod into the main pressure rod that penetrates the mold wall, and a cylinder formed in the main pressure rod. vIJ in the sky
This is achieved by accommodating a piston that is integrated with the pressure rod and guiding the hydraulic oil for the main pressure rod into the cylinder.

Dog JLJ Hereinafter, an embodiment of the present invention shown in FIGS. 2 to 5 will be described.

Figure 2 shows that it is possible to apply secondary pressurization pressure (ft=
A hydraulic control system 6 for secondary pressurization of the die casting device 10
It is shown together with 8. 1 of the die casting machine 1o. <Unit 1
Fixed platens 14.2 are connected to each other by a plurality of connecting rods 18 and face each other at intervals.
16 are fixedly erected. In addition, the fixed platen 14
．． Place it on IG, 3J! A movable platen 20 is disposed which is inserted into the cavity by a connecting rod 18 and is slidably displaced on the mounting plate 12.

Then, the fixed mold 22 is fixed to the fixed platen 16,
The movable JO type 24 is attached to the movable platen 20 via the holder 2G.
is fixed. The extrusion bottle 32 passes through the movable mold 24 and faces the gap A, and is used to pull the product from the movable mold 24 after VJ manufacturing is completed. It is fixed to an extrusion plate 28 supported by a penetrating holding rod 30. It is relatively moved in the direction of product separation.

Further, a hydraulic cylinder 38 for driving the movable platen is fixed to the fixed platen 14, and a push rod 4 integrated with the piston thereof is fixed to the fixed platen 14.
0 causes the movable platen 20 to be moved.

Further, an injection hydraulic cylinder 42 is fixed to the fixed platen 16 by a support rod 48, and an injection ram 4G connected to the piston 44 penetrates the fixed platen 1G and communicates with the runner of the fixed mold 22. The QJ exit sleeve 50 is slidably fitted into the injection sleeve 50, and when the injection ram 4G moves in the forward direction by the operation of the piston 44 after supplying molten metal into the injection sleeve 50 through the IT lagoon 52, the injection sleeve 50
The rFJ turbidity inside is pushed into the cavity Δ through Wfi.

On the other hand, a secondary pressurizing hydraulic cylinder 5G is supported on the movable mold 24 via a holding rod 54, and a main pressurizing rod G is integrated with a main piston 58 fitted in a hydraulic cylinder 56.
O is the extrusion plate 28 and the movable metal P! X! 24 so as to be slidably displaceable and enter into the cavity Δ. The main pressure rod 60 has a cylinder chamber 62 that is opened from the receiving surface side of the main piston 58.
A sub-pressure rod G6, which is integrated with the sub-piston G4 housed in the cylinder q62, penetrates the axial center of the main oil rod 60 and extends and retracts at the tip of the main pressure rod 60. Note that the pressure receiving surface area of the main piston 58 is Sz, the tip surface area of the main pressure rod 60 is Sl, and the pressure receiving surface area of the sub piston 64 is Sl.
, when the area of the tip surface of the sub-piston G4 is 82, St/
It is desirable to use 5t-82/S2 (Figure 3).

The hydraulic control system 68 of the secondary pressurizing hydraulic cylinder 56 takes out the working pressure of the injection hydraulic cylinder 42 through the oil passage 72 and operates using this as a guide. That is, when the operating pressure of the hydraulic cylinder 42 is asked of the sequence valve 74, the starting pressure is adjusted using the biasing spring force.The sequence valve 74 operates and discharge from the hydraulic pump 70 The pressurized oil flows through the oil passage 7G and the switching valve 78.
．． Ryuhaku g! l? ! ! Valve 80. The pressure rod 5 is connected to the secondary pressure hydraulic cylinder 56 through the pressure rod advancement oil passage 82.
The pressure control system 68 is configured such that the pressure control system 68 operates and enters the cavity A.

In such a configuration, a bale of molten metal (for example, aluminum alloy) is injected into the Ω1 output sleeve 50 through the pouring port 52, and the injection ram 4 is heated by the operation of the injection oil D cylinder 42.
When G is moved forward j1, the molten metal inside the injection sleeve 50 is: 1
: Pressurize inside Yaviti Δ! It is true. Further, at the same time as the injection hydraulic cylinder 42 starts operating, the hydraulic pressure in the high pressure chamber is led to the sequence valve 74 through the oil passage 72, and when the hydraulic pressure reaches a certain level (TI) (i.e.,
When the filling of molten metal into the main 11 pitey A is completed), the sequence valve 74 enters the communication state, and the switching valve 78 is displaced from the state shown in FIG. Oil road 7
6. Switching valve 78. Flow m adjustment valve 80. Oil passage 8 for advancing the n-rod
2, the oil discharged from the hydraulic pump 62 is sent to the high-pressure air of the secondary pressurizing hydraulic cylinder 56 (time T2), and the main pressurizing rod 60 advances and is hammered into the molten metal leaving the cavity A). Secondary pressurizing pressure is applied to the molten metal that has not yet completely solidified.

At this time, even after the main pressure rod 60 stops at the specified pressure due to the progress of solidification around the pressure rod 60, the hydraulic oil for the main pressure rod 60 is still acting on the sub piston G4. Sub pressure rod 6G
advances 11a and extends from the tip of the main pressure rod GO, and pressure equivalent to the solidified portion around the main pressure rod b is applied to the unsolidified molten metal 8G located in front of the tip of the main pressure rod GO. It will be done. The area ratio S+/S+=32/32 is the strip '1' required to achieve this equivalent pressure of 176.

The time from the above-mentioned time point (T1) to the end time point (T3) of the advance of the auxiliary pressure rod 66 is, for example, an aluminum ram alloy (JIS^DC12 material) used in the valve mechanism of an internal combustion engine.
0.1 to 0.8 seconds (T
3 Tl = 0.1-0.8).

Also, the rocker arm is 1! ? The molten metal filling pressure is approximately 6ooKg/ci, and the main oil tank is 58. The secondary pressing pressure by the auxiliary pressing rod 66 is approximately 2,500'l/ci (see FIGS. 4 and 5).

The secondary pressurizing pressure is applied until the molten metal in the cavity A finishes solidifying, and then, by switching the switching valve 78, the secondary pressurizing hydraulic cylinder 5G is passed through the pressurizing rod retreat oil passage 84.
Pressure oil is supplied to the main pressure rod 60°D) hn a rod 6
6 is forced back.

In this way, in this embodiment, the secondary pressurizing hydraulic cylinder 56
The main pressure rod 60 is provided with a cylinder chamber 62 that communicates with the main pressure rod 60, and an 01 pressure rod 66 integrated with a sub piston 64 inserted into the cylinder chamber 62 is constructed so as to appear and retract at the tip of the main pressure rod 60. Therefore, the secondary use IE) can be applied to the unsolidified molten metal existing in front of the tip of the main pressure rod 60 without applying an excessively sharp horn to the solidified portion of the molten metal around the main pressure rod GO.
− Force can be applied, thereby causing blow holes,
There are no internal defects caused by excessive shear stress, and the structure (7a
17 cast products with sufficiently refined structures are produced.

In the above embodiment, a single sub-pressure rod was built into the main pressure rod, but a plurality of sub-pressure rods may be built-in depending on the shape of the cavity and the quality of the molten metal. In this case, the sub-pressure rods may be formed into a concentric combination U.

As is clear from the above explanation, the die casting dispenser of the present invention 1! In this case, the main pressure rod penetrating the mold wall is
At least one wooden auxiliary pressure rod that retracts from the tip of the rod is built in, and a piston integrated with the auxiliary pressure rod is housed in a cylinder formed in the main pressure rod. Check the hydraulic oil for the main pressurizing rod, and with the main pressurizing rod, which has advanced into the molten metal and stopped, in order to apply secondary pressurizing pressure,
Move only the auxiliary pressure rod forward! 1″: Because I did it like this,
Without applying excessive pressure to the solidified molten metal around the main pressure rod, sufficient secondary pressure is applied by the auxiliary pressure rod to the unsolidified molten metal located toward the tip of the main pressure rod. Detailed and defect-free i! 1′1 weave structure) A casting product of Δ is obtained.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the main parts of a known die-casting mold and a pressure rod for secondary use, FIG. 2 is a schematic diagram of a die-casting device according to an embodiment of the present invention, and FIG. Fig. 4 is an enlarged view of the main part of the die-casting device, and Fig. 4 is a drawing showing a state in which the pressurizing rod of the die-casting device moves forward and secondary pressurizing pressure is applied to the molten metal in the mold.
The figure shows the die cast v4i? ff is a graph showing the temporal relationship between the molten metal filling pressure by the injection ram and the secondary pressurizing pressure by the pressurizing rod. 10...Die-cast mounting, 12...Base, 14...
・Fixed platen, 16...Fixed platen, 18...
Connecting rod, 20...-nJ! FJJ platen, 22・
・Fixed metal gJ, 24...ITJ metal mold, 2G...
Holding body, 28... Extrusion plate, 30... Holding rod, 32
... Extrusion bottle, 34... Hydraulic cylinder for extrusion
, 3G... Immediate rod, 38-... Hydraulic sill for movable platen drive -140... Push rod, 42... Hydraulic cylinder for injection, 44... Piston, 46... Injection ram, 48 ... Support rod, 50 ... Injection sleeve, 52
...Drinking port, 54...Holding rod, 5G...Hydraulic cylinder for secondary pressurization, 58...Main piston, 60...
1 pressure 1 rod, 62... Schilling chamber, 64... n1 piston, G6... auxiliary pressure cup, G8... hydraulic control system,
70... Hydraulic pump, 72... Oil path, 74... Sequence valve, 7G... Oil path, 78... Switching valve,
80...Flow rate adjustment valve, 82...Pressure rod ill advancing oil path, 84...Oil path for pressure rod rear 30, 8G...Unsolidified molten metal, A...Capity.

Claims (1)

[Scope of Claims] A die-casting device of a type in which a cavity of a mold is filled with molten metal and a pressure rod is advanced into the cavity to apply a secondary pressurizing pressure to the molten metal before the molten metal solidifies. The main pressure rod that penetrates the mold wall contains at least one sub-pressure rod that appears and retracts at the tip of the main pressure rod, and is housed in a cylinder formed in the width of the main pressure rod. A die-casting device characterized in that the auxiliary pressure rod is formed integrally with a piston on which the hydraulic oil of the main pressure rod acts directly.