JP3281231B2 - Die casting nozzle device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a die casting nozzle device for sprueless injection molding of molten metal.

[0002]

2. Description of the Related Art FIG. 14 is a sectional view showing a general structure of a die casting apparatus. In FIG. 14, the machine nozzle 4 and the mold 7 of the die casting machine are about 1
It has an inclination of 0 degree, and furthermore, the molten metal injection part 4a of the mechanical nozzle 4 is connected to the molten metal surface 9 of the molten metal (molten metal 9) in the melting furnace 1.
a higher than the height of the molten metal injection section 4
It has a structure to prevent the dripping from a.

When a product is formed by this die casting apparatus, first, a molten metal 9 melted in a melting furnace 1 is sent out by a plunger 3 reciprocating within a sleeve 2 and passes through a mechanical nozzle 4. Then, it is injected into the mold 7. The mold 7 includes a fixed mold 7a and a movable mold 7b. The molten metal injected from the mechanical nozzle 4 passes through a sprue bush 6 in the fixed mold 7a, and is fixed to the fixed mold 7a and the movable mold 7b.
Is supplied to the product forming section 8 'formed by the above. The molten metal supplied to the product forming section 8 ′ is cooled by the mold 7 and solidified. Thereafter, the movable mold 7b is moved in the direction of arrow A to open the mold 7, and the molded product 8 in which the product portion 8a, the runner portion 8b, and the sprue portion 8c are integrated as shown in FIG. 15 is taken out.

As shown in FIGS. 14 and 16, the sprue bush 6 in the die casting apparatus is cooled by cooling water 31 circulating in the outer peripheral portion, and the sprue bush 6 due to insufficient cooling when the mold 7 is opened. 8c was configured to prevent premature disconnection. On the other hand, mechanical nozzle 4
The outer periphery was heated by the mechanical nozzle heater 5 so that the molten metal did not solidify in the mechanical nozzle 4. Further, the injection portion 4a of the mechanical nozzle 4 is set in a state of being pressed against the mechanical nozzle touch portion 6a of the sprue bush 6 so as to prevent the molten metal from leaking.

[0005]

In the above conventional example,
The molten metal injected from the mechanical nozzle 4 is deprived of heat when passing through the cooled sprue bush 6, and has a considerably low temperature before reaching the product forming portion 8 ′ of the mold 7. For this reason, there is a problem that it is very difficult to fill the minute portion and the extremely thin portion of the product forming portion 8 ′, and there is a problem that the filling is often insufficient.

Further, since the sprue bush 6 in the above-mentioned conventional example is always cooled, the temperature of the molten metal injection part 4a of the mechanical nozzle 4 which is always in contact with the sprue bush 6 is reduced, and the molten metal is easily solidified. There is also a problem that the nozzle may be clogged. In order to prevent the nozzle clogging, it is conceivable to set the temperature of the molten metal injected from the mechanical nozzle 4 to be high. However, if the temperature of the molten metal is kept too high, the molten metal of the nozzle and the molten metal filling portion of the mold are not heated. This was not preferable because it caused rough skin and dross of molten metal.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to supply the molten metal to a product forming portion of a mold without lowering the temperature of the molten metal, thereby causing insufficient filling and nozzle clogging. An object of the present invention is to provide a die casting nozzle device which eliminates the problem.

[0008]

In the die casting nozzle apparatus of the present invention, a heat insulating ring is provided between the outer periphery of the molten metal injection section of the nozzle body and the mold. In addition, the fitting between the nozzle body and the heat insulating ring and the mold is always a gap fit at room temperature and also when the temperature rises during molding, so that the heat insulating ring is prevented from being damaged. Further, a compressible heat-resistant gasket is provided between the nozzle body and the heat insulating ring to prevent the passage of the molten metal. The heat-resistant gasket is compressed between them when securing the insulating ring to the nozzle body. The nozzle body is
It is fixed to the mold via a guide ring using a heat insulating material. Further, the nozzle body and the mold are arranged via a heat insulating material so that they do not come into direct contact with each other, thereby ensuring heat insulation between the nozzle body and the mold.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A nozzle body of a die casting nozzle device according to the present invention is supplied with heat from a mechanical nozzle by contact with the mechanical nozzle, and is insulated from a mold. For this reason, the nozzle body becomes a hot nozzle, the temperature drop of the molten metal due to the sprue bush as in the conventional example is eliminated, and the filling of the molten metal into the finely shaped portion and the extremely thin portion of the product forming portion of the mold becomes easy, Eliminates underfilling.

In particular, when the molten metal flows between the nozzle body and the mold, heat escapes from the nozzle body to the mold via the molten metal,
Since the temperature of the nozzle main body cannot be maintained at a temperature suitable for die casting, it is necessary to reliably prevent the flow of the molten metal between the nozzle main body and the mold. For this reason, in the present invention, as described later, compression of the heat insulating ring, the guide ring, and the heat-resistant gasket prevents the molten metal from flowing between the mold and the nozzle body, thereby ensuring heat insulation. are doing.

That is, the prevention of the inflow of the molten metal between the mold and the nozzle body is performed as follows. The nozzle main body provided in the mold has a structure in which the nozzle tip or the nozzle spacer and the nozzle base are fixed to the main body, and when fixing them, a heat-resistant gasket is provided between the heat insulating ring and the nozzle main body. Pressed. When the heat insulating ring is directly fixed to the nozzle body, the heat-resistant gasket is compressed between them. Thereby, the heat-resistant gasket is compressed, and the molten metal is prevented from flowing between the mold and the nozzle body. When the nozzle body touches the machine nozzle with the nozzle, heat is transmitted from the machine nozzle to the nozzle body, and the nozzle body is heated. As a result, the temperature of the molten metal injection part of the nozzle body is almost equal to that of the mechanical nozzle, that is, a temperature suitable for die casting.

[0012]

FIG. 1 is a sectional view showing a state in which a die casting nozzle device according to one embodiment of the present invention is incorporated in a mold 22 and is attached to a die casting machine. FIG. 2 is a sectional view showing the die casting nozzle device shown in FIG. FIG. 3 is a side view of the die casting nozzle device shown in FIG. 2 as seen from the injection direction, and FIG. 4 is a view of the die casting nozzle device shown in FIG. 2 seen from the nozzle touch direction. It is a side view.

As shown in FIGS. 1 and 2, the fixed die 22a of the mold 22 is provided with a substantially cylindrical mounting hole 22d, and the nozzle body 11 is accommodated in the mounting hole 22d. The nozzle body 11 has a substantially cylindrical body portion 41 and a nozzle tip 21 fixed in a tip 41a thereof.
It is composed of The nozzle tip 21 has a flange-shaped locking portion 21a on the outer periphery of the tip, and a screw portion 21b is formed on the outer periphery of the other end. It is fixed to the main body 41 by being screwed into a screw formed on the periphery. The nozzle main body 11 composed of the main body 41 and the nozzle tip 21 has a higher heat conductivity than heat-resistant steel or heat-resistant steel, for example, a heat conductivity of 0.25 cal / sec · cm ·.
It is made of a tungsten alloy having a temperature of ℃ or more. A protrusion 41d is provided on the outer periphery of the body portion 41 of the nozzle body 11 near the mechanical nozzle touch portion 41c.
An annular concave portion 41e that is compatible with a heat-resistant gasket described later is provided on the end surface on the 1a side.

The heat insulating ring 12 is made of a material having good heat resistance and low thermal conductivity, such as ceramic, and a material having mechanical strength enough to withstand pressing. The heat insulating ring 12 has an outer diameter that is compatible with the outflow side opening 22c of the mounting hole 22d, and has an annular concave portion 12b that is adapted to the locking portion 21a of the nozzle tip 21 on its emission side end surface 12a. ing. As shown in FIG. 2, the heat insulating ring 12 is provided with a nozzle tip 21 penetrating the heat insulating ring 12.
Is fixed to the main body 41 by being sandwiched between the locking portion 21 a of the nozzle tip 21 and the end face of the main body 41. As shown in FIG. 3, a slit 32 is provided on the end face of the nozzle tip 21 so that the nozzle tip 21 can be rotated by a driver or the like. Instead of the slit 32, a hexagonal hole that fits a hexagonal bar wrench may be formed, or another similar type may be used.

The heat-resistant gasket 14 is made of a soft material such as gold or copper having a certain degree of heat resistance, a metal O-ring such as a stainless O-ring, or a metal C-ring such as a stainless C-ring. It is formed to have a size that can be accommodated in the concave portion 41e of the portion 41, and has a thickness that slightly protrudes from the concave portion 41e when not pressed. This heat resistant gasket 14
As described above, when the heat insulating ring 12 is fixed to the main body 41 by the nozzle tip 21,
And between the main body 41.

The guide rings 23 and 24 have heat resistance,
The guide ring 23 is externally fitted to the main body 41 of the nozzle body 11 so as to sandwich the protruding portion 41d, and is positioned by being locked by the step 22e in the mounting hole 22d. The main body portion 41 is supported in contact with the inner surface of the device, and the mechanical nozzle touch portion 41c is positioned at an appropriate position.

The back plate 15 is fixed to the end face of the fixed die 22a with screws 16 in order to prevent the nozzle body 11 and the guide rings 23 and 24 from dropping out of the mounting holes 22d. In this back plate 15,
Mechanical nozzle touch part 41 of main body part 41 of nozzle main body 11
A hole 15a slightly larger than the outer diameter of the nozzle body c is provided, and the mechanical nozzle touch portion 11c of the nozzle body 11 is set to slightly protrude from the hole 15a.

In the state shown in FIGS. 1 and 2, when the die casting is started, the molten metal is supplied to the nozzle body 1.
1 and is filled in the product forming part 10 ′ of the mold 22. The molten metal thus filled in the mold 22 is cooled and solidified. Thereafter, when the movable mold 22b moves in the direction of the arrow A and the mold 22 opens, the molded product 10 in which the product portion 10a and the runner portion 10b are integrated as shown in FIG. 5 is taken out. At this time, since the nozzle body 11 is heated by the heat from the mechanical nozzle, the sprue portion 8c is not formed unlike the conventional molded product 8 shown in FIG.

As described above, when the molded article 10 is taken out, the temperature of the nozzle tip 21 of the nozzle main body 11 rapidly recovers to an appropriate temperature at which molding is possible by the heat of the main body 41.
In the present embodiment, since the cross-sectional area of the nozzle tip 21 is set to be sufficiently smaller than the cross-sectional area of the main body 41, a difference occurs in the heat capacity between the nozzle tip 21 and the main body 41, and Since the heat capacity is larger, the temperature of the nozzle tip 21 can be rapidly recovered. still,
If a material having good thermal conductivity is used for the main body 41 and the nozzle tip 21, a more rapid temperature recovery can be achieved.

At the time of the above-mentioned die casting, the molten metal is filled in the gap between the nozzle tip 21 and the heat insulating ring 21 and the nozzle tip 21.
The heat-resistant gasket 14 flows through the threaded portions of the main body 41 and the heat-insulating ring 12 and the main body 4.
1 is sealed between the nozzle body 11 and the fixed mold 22a because they are compressed to seal the gap therebetween.

Since the temperature of the mold 22 is much lower than the temperature of the molten metal, the molten metal is solidified in the gap 17 between the heat insulating ring 12 and the mold 22 before flowing into the interior. Is small, it does not flow without using a gasket or the like.

The difference in the coefficient of thermal expansion between the fixed mold 22a and the nozzle body 11 is absorbed by sliding between the outflow opening 22c of the fixed mold 22a and the heat insulating ring 12.

FIGS. 6 and 7 are enlarged sectional views of a main part showing a modification in which a heater 18 is provided on the outer peripheral portion of a main body 41 as a heating means for heating the nozzle main body 11 in the embodiment shown in FIG. And a side view. The heater 18 has a temperature detection unit inside and controls the temperature of the nozzle body 11. Reference numeral 18a denotes a lead wire of the heater 18, which is connected to a temperature control device (not shown). By providing the heater 18 in this manner, the temperature of the nozzle body 11 can be quickly raised to an appropriate temperature, and more efficient molding is facilitated. That is, the time for continuous molding can be extremely reduced. In addition, it is necessary to make the fixed mold 22a thick,
If the nozzle body 11 has to be lengthened, it is particularly effective to provide a heating means such as a heater. Furthermore,
It is more effective to provide a heating means in the nozzle body as the metal material has a higher melting point.

In the nozzle device shown in FIG.
An annular step 12c is formed on the outer periphery of the heat insulating ring 12 on the end face 12a side, and the step 12c is fixed to the fixed mold 22.
Step 22f provided inside the outflow side opening 22c of FIG.
Is set to face. In order to absorb the difference in the coefficient of thermal expansion to some extent and prevent breakage of the heat insulating ring 12, a slight gap is set between the steps 12c and 22f.

FIGS. 8 and 9 are enlarged sectional views and side views of a main part showing a further modification in which a protective cover 19 is provided between the nozzle body 11 and the fixed mold 22a of the mold 22 in the modification shown in FIG. It is. By providing the protective cover 19 in this manner, the nozzle device including the nozzle body 11, the heat insulating ring 12, and the like is unitized to facilitate the attachment and detachment of the nozzle. In addition, this protective cover 19
0 is fixed to the fixed mold 22a.

FIGS. 10 and 11 are an enlarged sectional view and a side view of a main part showing a modified example in which the structure of the nozzle body 11 and the fixing structure of the heat insulating ring 12 in the embodiment shown in FIG. 2 are changed. The nozzle body 11 in this nozzle device is made of a single body without using the nozzle tip 21, and has a step portion 11b on the outer periphery near the tip portion 11a. On the other hand, the heat insulating ring 12 is provided with an annular concave portion 12d on an end surface thereof, and the heat-resistant gasket 14 is accommodated in the concave portion 12d. This heat insulating ring 12 is
Of the nozzle body 11 with a set screw 28 and fixed thereto. In this modified example, since the nozzle tip 21 is not used,
Compared with the nozzle device shown in FIG. 2 and FIG. 6 and the like, the structure is such that the seal between the step heating ring 12 and the nozzle main body 11 is easily performed.

FIG. 12 is an enlarged sectional view of a main part showing a further modification in which the heat insulating ring 12 in the modification shown in FIG. 10 is further modified. Insulation ring 12 in this nozzle device
Is provided with a screw portion 12e on its inner peripheral surface, and is fixed to the nozzle body 11 by screwing the screw portion 12e to a screw portion 11e provided on the outer periphery near the distal end portion 11a of the nozzle body 11. Have been. In this nozzle device, an annular concave portion 1 is formed on a step 11b of a nozzle body 11.
1d is provided, in which the heat-resistant gasket 14 is stored. In this nozzle device, the heat insulating ring 12 can be fixed to the nozzle body 11 without using a screw or the like, and the number of parts can be reduced.

FIG. 13 is an enlarged sectional view of a main part showing a modified example in which the structure of the nozzle body 11 and the fixing structure of the heat insulating ring 12 in the embodiment shown in FIG. 2 are changed. The nozzle body 11 of this nozzle device has a locking portion 41g formed to the tip of the nozzle and protruding like a flange on the outer periphery near the tip portion 41f and a screw portion 41 on the outer periphery of the rear end.
h, a cylindrical nozzle spacer 25 externally fitted to the main body 41, and a screw portion 26a screwed to the screw portion 41h of the main body 41 are provided on the inner peripheral portion and further on the outer peripheral portion. And a substantially cylindrical nozzle base 26 on which a flange-like protrusion 26b is formed. On the other hand, the heat insulating ring 12 is externally fitted to the main body 41 from the right rear end side in the figure, and a stepped portion 12f formed therein is engaged with the engaging portion 41g of the main body 41 to move in the injection direction. It is configured not to fall off. In this nozzle device,
The heat insulating ring 12 externally fitted to the main body 41 is fixed while pressing the nozzle base 26 via the nozzle spacer 25 when fixing the nozzle base 26 to the main body 41. For this purpose, annular concave portions 25a and 25b are provided on both end surfaces of the nozzle spacer 25, respectively, and heat-resistant gaskets 14 and 27 for preventing inflow of molten metal are accommodated therein. The heat-resistant gasket 27 is for preventing the molten metal passing through the main body portion 41 and the screw portions 41h and 26a of the nozzle base 26 from flowing between the fixed mold 22a and the nozzle main body 11. Further, the heat-resistant gasket 14 blocks the inflow of molten metal passing through the gap between the heat insulating ring 12 and the nozzle body 11. Further, the nozzle spacer 25 is formed of the same material as that of the main body portion 41. By fitting the nozzle spacer 25 to the main body portion 41, the same effect as the thickening of the main body portion 41 can be obtained.

[0029]

According to the present invention, the conventionally used sprue bush is abolished and the hot nozzle insulated from the mold is used.
The molding of fine products can be facilitated. In particular, it is possible to easily form an ultra-thin product, which was difficult to form with a conventional apparatus.

Also, in the molding of small parts by the conventional apparatus, the sprue portion of the molded product tends to occupy a large portion, the product portion occupies a small portion, and the quality of the product portion tends to be unstable. According to the invention, since the sprue portion is eliminated, very stable molding can be performed. Furthermore,
The amount of return material is reduced by the amount of the sprue portion, and the cost of re-melting can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state where a die casting nozzle device of the present invention is incorporated in a mold and attached to a die casting machine.

FIG. 2 is an enlarged sectional view of a main part showing a detailed configuration of the nozzle device for die casting shown in FIG.

FIG. 3 is a side view of the die casting nozzle device shown in FIG. 2 in an injection direction.

4 is a side view of the die casting nozzle device shown in FIG. 2 in a nozzle touch direction.

FIG. 5 is a side view showing a molded product molded by the die casting nozzle device shown in FIG. 1 and the like.

FIG. 6 is an enlarged sectional view of a main part showing a modification in which a heater is provided on the outer peripheral portion of the main body as a heating means for heating the nozzle main body in the embodiment shown in FIG. 2;

FIG. 7 is a side view of the die casting nozzle device shown in FIG.

FIG. 8 is an enlarged sectional view of a main part showing a modified example in which a protective cover is provided between the nozzle body and the fixed mold of the mold in the modified example of FIG. 6;

FIG. 9 is a side view of the die casting nozzle device shown in FIG.

FIG. 10 is an enlarged sectional view of a main part showing a modified example in which the structure of the nozzle body and the fixing structure of the heat insulating ring in the embodiment shown in FIG. 2 are changed.

FIG. 11 is a side view of the nozzle device for die casting shown in FIG.

FIG. 12 is an enlarged sectional view of a main part showing a further modification in which the heat insulating ring in the modification shown in FIG. 10 is further modified.

13 is an enlarged sectional view of a main part showing a modified example in which the structure of the nozzle body and the fixing structure of the heat insulating ring in the embodiment shown in FIG. 2 are changed.

FIG. 14 is a sectional view showing a conventional die-casting nozzle device.

FIG. 15 is a side view showing a molded product molded by the die casting nozzle device shown in FIG.

FIG. 16 is a sectional view showing a sprue bush used in the die casting nozzle device shown in FIG. 14;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Melting furnace 2 Sleeve 3 Plunger 4 Mechanical nozzle 4a Molten metal injection part 5 Mechanical nozzle heater 6 Sprue bush 6a Mechanical nozzle touch part 7, 22 Die 7a, 22a Fixed type 7b, 22b Movable type 8, 10 Molded product 8a, 10a Product part 8b, 10b Runner part 8c Sprue part 8 ', 10' Product forming part 9 Molten metal 9a Hot surface 11 Nozzle body 11a Tip part 11b Step part 11d Depression 11e Screw part 12 Heat insulating ring 12a End face 12b, 12d Depression 12c, 12f Step Part 12e Screw part 13 Guide ring 14 Heat resistant gasket 15 Back plate 16 Set screw 17 Gap 18 Heater 18a Lead wire 19 Protective cover 20 Set screw 31 Cooling water 41 Main part 41a Tip 41c Mechanical nozzle touch part 41d Projection 41e Recess 41f Point Part 41g engaging portion

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B22D 17/02

Claims (6)

(57) [Claims] 1. A nozzle body, a heat insulating ring fitted in the mold and the nozzle body by a clearance fit while maintaining heat insulation between the mold and the nozzle body, and heat insulation between the mold and the nozzle body and the metal mold. A guide ring for maintaining the position of the nozzle body in a mold; and a compressive heat-resistant gasket for preventing molten metal from flowing between the nozzle body and the mold. Wherein the heat-resistant gasket is compressed and fixed to a nozzle body, and the nozzle body is fixed to the mold via the guide ring. 2. The nozzle body according to claim 1, wherein the nozzle body comprises a main body, and a nozzle tip for fixing the heat insulating ring to the tip of the main body with the heat insulating ring interposed between the main body and the nozzle tip. Die casting nozzle device. 3. The nozzle body has a main body having a locking portion for locking the heat insulating ring at a distal end, a nozzle base fixed to a rear end of the main body, a nozzle base fitted to the main body, and 2. The nozzle spacer according to claim 1, further comprising a nozzle spacer disposed between the nozzle base and the heat insulating ring.
The nozzle device for die casting according to the above. 4. A nozzle apparatus for die casting according to claim 1, wherein a heating means capable of controlling the temperature is provided in said nozzle body. 5. The nozzle device for die casting according to claim 1, wherein a heat-resistant metal material having a higher thermal conductivity than heat-resistant steel is used for the nozzle body. 6. The nozzle body according to claim 1, wherein the nozzle main body is formed such that a cross-sectional area of an injection part thereof is smaller than a cross-sectional area of a central part. Die casting nozzle device.