JPH0899161A - Ejection sleeve for die casting - Google Patents

Abstract

PURPOSE: To obtain a formed product having excellent pressure resistance and casting surface, etc., by forming a reversed trapezoidal recessed cutting part on the inner peripheral upper surface of an ejection sleeve, fitting a fitting member arranged with a gas venting hole communicated with a vacuum pump and evacuating the inside of the ejection sleeve. CONSTITUTION: Molten metal is poured into the ejection sleeve 7, and the advancing speed of a plunger tip 9 is changed from a low speed to high speed at the point of time when the tip kicks a limit switch 42 by advancing a plunger tip 9 at low speed. The air in the ejection sleeve 7 is sucked to the reduced pressure state with the vacuum pump 16 in the condition of closing a molten metal pouring hole 10 with the plunger tip 9. In the case the molten metal is comparatively slowly solidified, the limit switch 42 is set so as to execute the change-over of the speed at the position near a gate 14, and the fitting member, in which an air venting hole is set near the gate 14, is used. In the case the molten metal is comparatively quickly solidified, on the contrary, the fitting member, in which the air venting hole is set distant from the gate 14, is used. In such a way, the formed product having excellent pressure resistance and casting surface, etc., is obtd., by sufficiently evacuating the ejection sleeve 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold chamber type injection sleeve for die casting or squeeze casting of non-ferrous metals such as aluminum alloy and zinc alloy.

[0002]

2. Description of the Related Art Conventionally, in a horizontal die clamping / horizontal casting die casting machine, a plunger tip 9 is slidably housed in an injection sleeve 7 having a pouring port 10 at one end, and the other end of the injection sleeve 7 is held. Through the gate to the product cavity 6 formed between the molds, and the molten metal 11 in the injection sleeve 7 is filled into the cavity 6 by the entry of the plunger tip 9 to solidify. There is.

[0003]

However, the conventional injection sleeve 7 as described above has the following problems. That is, when the molten metal 11 is injected, the air existing in the upper space 12 in the injection sleeve entrains the air in the injection sleeve 7 and is press-fitted into the cavity 6 as it is, resulting in a large number of cavities. Had deteriorated the strength, pressure resistance, and skin.

The upper space 12 in such an injection sleeve
In order to smoothly discharge the air, the air vent hole 13 is provided in the upper part of the injection sleeve 7 as shown in FIG. Particularly, since the air vent hole 13 is provided at the position where the plunger tip 9 switches from the low speed to the high speed, and the air is rapidly degassed by the vacuum pump 16 from the air vent hole 13 through the conduit 15 in the injection sleeve. Although there is an advantage that the air in the upper space 12 can be discharged smoothly, the switching position of the plunger tip 9 from the low speed to the high speed is, for example, inside the molded product even if some wrinkles occur outside the molded product. When it is desired to have a small number of cavities, it is performed at a position relatively close to the gate 14 such as a gate driving.

On the other hand, when it is desired that the molded product has a large number of porosity inside and no luster outside the molded product, the switching position is changed from low speed to high speed as soon as possible after the start of injection. The position of the air vent hole 13 must be changed at the same time as this movement.

Further, in the case of die casting using the molten metal 11 which is relatively easy to solidify, it is necessary to switch the position from low speed to high speed within a short time from the start of injection (position away from the gate 14). On the contrary, in the case of die casting using the molten metal 11 having a slow solidification, it is necessary to perform the switching position from the low speed to the high speed at a position close to the gate 14, and in order to move the position of the air vent hole 13. There is a problem that it is virtually impossible to replace the injection sleeve 7 each time.

The present invention has been made in view of the above-mentioned problems of the prior art, and provides an injection sleeve for die casting in which the air in the injection sleeve can be freely evacuated in accordance with the switching position from low speed to high speed. That is the purpose.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, a horizontal injection in which a molten metal is cast into a cavity of a mold which is clamped from the horizontal direction. A recessed portion having an inverted trapezoidal cross section is formed on the upper surface of the inner periphery of the sleeve, and fitting members having different lengths can be mounted in the recessed portion, and a deaeration hole communicating with a vacuum pump is provided in the fitting member. According to the second aspect of the present invention, a recessed portion having an inverted trapezoidal cross section is formed on the upper surface of the inner circumference of a horizontal injection sleeve in which the molten metal is cast into the cavity of the mold that is clamped from the horizontal direction. And a fitting member having a different length can be mounted in the recessed portion, and an opening / closing device for deaeration that is separated from the fitting member in the axial direction and communicates with a vacuum pump is provided. To do.

[0009]

[Operation] A recessed portion is provided on the inner peripheral upper surface of the injection sleeve in accordance with the switching position from the low speed to the high speed at the time of injection, and fitting members having different lengths are replaceably attached to the recessed portion.
Since a deaeration hole and an opening / closing device leading to the vacuum pump are provided in this fitting member, the deaeration hole or the opening / closing valve serves as an air vent and the upper air of the molten metal in the injection sleeve can be smoothly discharged. Molded products with no wrinkles or porosity inside or outside can be formed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the injection sleeve for die casting according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a die casting apparatus having an injection sleeve according to the present invention, FIG. 2 is a sectional view of an injection sleeve at the completion of pouring of molten metal, and FIG. 3 is an injection at a low speed. FIG. 4 is an explanatory view showing the air flow in the sleeve, FIG. 4 is an explanatory view showing the air flow in the injection sleeve immediately before switching from low speed to high speed, and FIG. 5 is an explanation showing the air flow in the injection sleeve at high speed. FIG. 6, FIG. 6 is a horizontal cross-sectional view seen from AA of FIG. 2, FIG. 7 is a vertical cross-sectional view showing another embodiment of the injection sleeve for die casting according to the present invention, and FIG. 8 is a partially enlarged cross-sectional view of the opening / closing device. is there.

In FIG. 1, reference numeral 22 is a fixed base 20.
The movable platen 22 is arranged in a horizontal direction by a hydraulic piston (not shown).

A die base 24 is fixed to one side surface of the movable platen 22, and a movable die 26 is fixed to the die base 24.

Reference numeral 28 is a fixed platen fixed on the fixed base 20, and a fixed mold 30 is fixed to the fixed platen 28.

When the movable mold 26 slides to the right in the figure and comes into contact with the fixed mold 30, the movable mold 26 and the fixed mold 3 are brought together.
Product cavity 6 between 0 and
The gate 14 that connects the runner portion 32 with the runner portion 32 is formed.

One end of the injection sleeve 7 is opened in the runner portion 32, and the plunger tip 9 is inserted from the other end side of the injection sleeve 7.

Then, the molten metal 11 is injected from a pouring port 10 provided in the injection sleeve 7, and the plunger tip 9 is advanced to the left in the figure, so that the molten metal 11 is covered by the runner portion 32, the gate 14 and the product cavity 6. Leading to.

The product cavity 6 and the runner portion 32
The push pin 3 fixed to the push plate 36 at a position facing
8 is arranged and has a role of pushing out the product when the movable mold 26 and the fixed mold 30 are opened.

Reference numeral 40 is an exhaust valve, and 42 is a limit switch for detecting the speed switching position of the plunger tip 9 from low speed to high speed.

In the present embodiment, in particular, as shown in FIG. 6, a recessed portion 7b having a predetermined length and having an inverted trapezoidal cross section is formed on the axially inner peripheral upper surface 7a of the injection sleeve 7.

The recess 7b is formed from the vicinity of the fixed platen 28 of the injection sleeve 7 to the rear end side of the injection sleeve 7, and a fitting member 7c having a trapezoidal cross section can be mounted in the recess 7b. ing.

Further, the fitting member 7c has an air vent hole 1
3 is provided, and the air vent hole 13 is a vertical hole 13a.
The air vent hole inlet 13c having a hole and a lateral hole 13b provided in the axial direction of the injection sleeve 7 facing the fixed platen 28 on the upper surface portion of the fitting member 7c on the side facing the circumferential upper surface 7a and the fixed platen 28 are close. An air vent port 13 that communicates with a vacuum pump 16 via a conduit 15 on the inner peripheral upper surface 7a of the injection sleeve 7.
It is composed of d.

Particularly, in this embodiment, the air vent hole inlet 13c
By preparing a fitting member 7c in which the position of is variously changed in the axial center direction of the injection sleeve 7, it is possible to selectively use the molten metal 11 according to the type of the molten metal 11 and desired internal / external initial specifications of the molded product. ing. Reference numeral 44 is a holding bolt for fixing the position of the fitting member 7c.

Next, the operation of this embodiment will be described.

First, the movable mold 26 is advanced to move the fixed mold 3
Abut 0 to clamp the mold. Then, the exhaust valve 40 is opened.

Next, a predetermined amount of molten metal 11 is poured from the pouring port 10 of the injection sleeve 7 (FIG. 2), the plunger tip 9 is advanced at a low speed (FIGS. 3 and 4), and the limit switch 42 is turned off. To move forward at high speed.

After the plunger tip 9 starts to move forward at a low speed, the vacuum pump 16 is started under the condition that the plunger tip 9 closes the pouring port 10, and the air in the upper space 12 in the injection sleeve is sucked and discharged until the pressure is reduced. .

By the way, the injection sleeve 7 is provided with the air vent hole inlet 13c so that the air in the upper space 12 in the injection sleeve can sufficiently escape from the air vent hole 13 of the fitting member 7c corresponding to the speed switching position from the low speed to the high speed. Although it is possible to mount the fitting member 7c that can be changed in the axial center direction, generally, the fitting portion member 7c is changed based on the following concept.

First, the commonly used Al-Si-C
In the case of using the aluminum alloy of u-type ADC 12 (including sillmin), the limit switch 42 detects the speed switching position from low speed to high speed at the position close to the gate 14 because the solidification of the molten metal 11 is relatively slow. Will be done. Therefore, the fitting member 7c provided with the air vent hole inlet 13c near the gate 14 may be used.

Next, Al- which has been used recently
In the case of using an aluminum alloy of Mg-based ADC5 or ADC6 (hydronalium) or in rotor casting using pure Al, the solidification of the molten metal 11 is fast, so that it takes a relatively short time from the start of injection (a position away from the gate 14). Since switching from low speed to high speed is performed, the fitting member 7c provided at the position where the air vent hole inlet 13c is separated from the gate 14 may be used.

Molten metal 1 poured into the injection sleeve 7
When 1 moves from low speed forward of the plunger tip 9 to high speed advance and fills the product cavity 6, the plunger tip 9 has already blocked the air vent hole inlet 13c, so that the air vent of the upper space 12 in the injection sleeve continues. Is difficult (Fig. 5).

After a lapse of a certain time (set by a timer), the exhaust valve 40 is closed by moving the rod 9a leftward in FIG. 5, and the plunger tip 9 is advanced at a high speed to move the inside of the injection sleeve 7. All the molten metal 11 is injected into the product cavity 6.

Thereafter, when the molten metal 11 filled in the product cavity 6 is completely solidified, the movable mold 26 is moved to the left in FIG. 1 to open the mold, and the extrusion pin 38 is extruded to form a molded product ( Product). The above operation is repeated to perform die casting.

FIG. 7 shows an embodiment similar to the embodiment of the present invention, in which the opening / closing device 50 is provided on the inner peripheral upper surface 7a of the injection sleeve 7 in the direction orthogonal to the axial center of the injection sleeve 7. A plurality (three in this embodiment) are arranged.

The opening / closing device 50 includes a cylinder 52 and a valve rod 5.
4 and an on-off valve 56. A semi-circular cover 60 for forming the air vent hole 13 is mounted on the outer peripheral upper surface of the injection sleeve 7.

A cylinder 52 is erected on the cover 60, and an air vent hole inlet 13c is provided between the cylinder 52 and a fitting member 7c provided on the inner peripheral upper surface 7a of the injection sleeve 7 via a valve rod 54. Is forming.

A through hole 58 is provided in the periphery of the valve rod 54, and the opening / closing valve 56 is lowered to hold the air vent hole inlet 13c so that a vacuum pump is provided from the through hole 58 through the air vent hole 13 and the conduit 15. By means of 16, the air in the upper space 12 inside the injection sleeve is forcibly discharged to reduce the pressure.

Each of the opening / closing devices 50 is connected to a limit switch (not shown), and when the plunger tip 9 advances to inject the molten metal 11 toward the product cavity 6 side, the opening / closing device 50 on the side close to the plunger tip 9 advances. It is configured to operate one after another to close the air vent hole inlet 13c.

Since the structure shown in FIG. 7 is used, the molten metal 11 is poured into the injection sleeve 7 from the pouring port 10 by a predetermined amount, and then the plunger tip 9 is advanced, but at a position apart from the gate 14, for example. When you want to switch from low speed to high speed, use only the switchgear 50a and other switchgear 50
For b and 50c, the air vent hole inlet 13c may be closed from the beginning.

When it is desired to switch from the low speed to the high speed at the position closest to the gate 14, the opening / closing devices 50a, 50
If the limit switches of b and 50c are all closed by advancing the plunger tip 9 in order of 50a → 50b → 50c, the upper space 1 in the injection sleeve 1
The air of No. 2 can be sufficiently deaerated until the pressure is reduced.

[0041]

As is apparent from the above description, in the first invention according to the present invention, horizontal injection is performed so that the molten metal is cast into the cavity of the mold which is clamped from the horizontal direction. A recessed portion having an inverted trapezoidal cross section is formed on the upper surface of the inner periphery of the sleeve, and fitting members having different lengths can be mounted in the recessed portion, and a deaeration hole communicating with a vacuum pump is provided in the fitting member. Further, in the second aspect of the invention, a recessed portion having an inverted trapezoidal cross section is formed on the upper surface of the inner periphery of the horizontal injection sleeve in which the molten metal is cast from the horizontal direction into the cavity of the mold which is clamped. By forming a fitting member having a different length in the recessed portion, and by disposing an opening / closing device for deaeration that is separated in the axial direction of the fitting member and communicates with a vacuum pump, Depending on the type of molten metal and the internal / external specifications of the molded product, low speed While freely select the switch position of the high velocity, since the air vent of the injection sleeve top can be performed sufficiently readily molded strength, breakdown voltage, excellent molded articles such as skin.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a die casting device having an injection sleeve according to the present invention.

FIG. 2 is a cross-sectional view of the injection sleeve when the molten metal is completely poured.

FIG. 3 is an explanatory diagram showing a flow of air in an injection sleeve at a low speed.

FIG. 4 is an explanatory diagram showing the flow of air in the injection sleeve immediately before switching from low speed to high speed.

FIG. 5 is an explanatory diagram showing an air flow in the injection sleeve at a high speed.

FIG. 6 shows a cross-sectional view as seen from AA of FIG.

FIG. 7 is a sectional view showing another embodiment of the injection sleeve for die casting according to the present invention.

FIG. 8 is a partially enlarged sectional view of the opening / closing device.

FIG. 9 is a vertical cross-sectional view of a conventional die casting device having an injection sleeve.

[Explanation of symbols]

 6 Product Cavity 7 Injection Sleeve 7a Inner Upper Surface 7b Recess 7c Fitting Member 9 Plunger Chip 10 Pouring Port 11 Molten Metal 12 Upper Space Inside Injection Sleeve 13 Air Venting Hole 13a Vertical Hole 13b Side Hole 13c Air Venting Hole Inlet 13d Air Venting Hole Outlet 14 Gate 15 Conduit 16 Vacuum pump 22 Movable platen 26 Movable mold 28 Fixed platen 30 Fixed mold 32 Runner part 36 Extrusion plate 42 Limit switch 50 (50a, 50b, 50c) Opening device 52 Cylinder 54 Valve rod 56 Opening valve 58 Through hole

Claims (2)

[Claims] 1. A recessed portion having an inverted trapezoidal cross section is formed on an upper surface of an inner periphery of a horizontal injection sleeve in which a molten metal is cast into a cavity of a mold which is clamped from the horizontal direction. An injection sleeve for die casting, characterized in that fitting members having different lengths can be attached to the cutout portions, and deaeration holes communicating with a vacuum pump are provided in the fitting members. 2. A recessed portion having an inverted trapezoidal cross section is formed on an upper surface of an inner circumference of a horizontal injection sleeve in which a molten metal is cast from a horizontal direction into a cavity of a mold which is clamped. An injection device for die casting, characterized in that fitting members having different lengths can be attached to the cutout portion, and an opening / closing device for deaeration communicating with the vacuum pump is provided separately in the axial direction of the fitting member. sleeve.