JPH08243708A - Plunger injection mechanism in hot chamber die casting machine - Google Patents

Abstract

PURPOSE: To provide a plunger mechanism in a hot chamber die casting machine, in which the leakage of molten metal in an injection mechanism in the hot chamber die casting machine excellent in corrosion resistance to the molten metal is surely eliminated and also, this durability is drastically improved, and the design and manufacture are easily executed. CONSTITUTION: In the plunger injection mechanism in the hot chamber die casting having the plunger body 8 composed of a sleeve 10 and a ceramic plunger sliding in the sleeve 10 and a spouting part for injection-forming the molten metal 15 pressurized by sliding the plunger into a die 4, an annular groove 17 is arranged on the outer periphery of the plunger and also, a ring 9 is loosely fitted to the annular groove 17. An introducing hole for guiding the molten metal 15 pressurized to the annular groove 17 is arranged in the inner part of the plunger, and the side surface in the pressurized molten metal flowing direction in the annular groove 17 is made to be an inclining surface to the diameter direction of the plunger.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plunger injection mechanism for a hot chamber die casting machine, which can easily eliminate metal leakage in the injection mechanism for a hot chamber die casting machine which is easy to design and manufacture and has excellent corrosion resistance to molten metal. , Is intended to dramatically improve its durability.

[0002]

2. Description of the Related Art Hot chamber die casting machines for casting aluminum or other molten metal have been known. That is, the general structure of a hot chamber die casting machine for casting with such an aluminum melt is as shown in FIG. 9, in which a heater 3 is provided so as to melt the aluminum melt 15 and maintain it at a constant temperature. The combined holding furnace 1 is installed on the pedestal 2, and the gooseneck 13 provided in the holding furnace 1 is provided with the nozzle 14 and is crimped to the die 4 provided on the die plate 5 to form a discharge part. .

Crimping between the die 4 and the nozzle 14 is performed by tightening the pedestal 2 and the die plate 5 with a clamp (not shown) or the like, and a plunger 21 is inserted into the sleeve 10. The plunger 21 is connected to the hydraulic piston 6 via a coupling 7,
When the hydraulic piston 6 descends, the plunger 2
1 descends in the sleeve 10, the molten metal in the sleeve 10 is pressurized, passes through the gooseneck 13, and is injected from the nozzle 14 into the cavity of the mold 4 for casting.

The plunger 21 is disclosed in JP-A-56-23.
358 and Japanese Unexamined Patent Publication No. 56-23359 disclose a straight tube type plunger having a straight tube shape with no ring 9a attached to the plunger 21. However,
Even if the straight tube type plunger without this ring is simple in structure as shown in the figure, its clearance should be strictly controlled to 0.04 mm or less in order to obtain a stable sealing effect with the sleeve 10. It is necessary, and because its material is ceramics in view of its corrosion resistance to molten metal, its processing accuracy must be properly maintained over the entire surface, and such processing is extremely difficult, and of course the processing cost is low. It has to be huge.

Further, this product requires a high level of technology for centering when assembling the sleeve 10 and the straight-cylindrical plunger, which requires careful attention and enormous man-hours, and also causes vibration and vibration during operation. The slight misalignment due to thermal deformation causes galling, which has the disadvantage of extremely shortening the life of the plunger and sleeve.

By the way, in the case of a molten metal having a low corrosiveness, a ring 9a can be used for the plunger 21 as shown in FIG. 9, and the ring 9a acts as a spring and acts on the inner surface of the sleeve 10. Since a sealing effect can be obtained by crimping and such a spring action is required, it is considered that the member is made of an elastic metal member such as steel.

However, in a plunger for injecting molten aluminum or the like, since the molten aluminum corrodes almost all metal materials, a plunger made of metal is not practically available. As a technique for solving such a disadvantage, the ring 9a shown in FIG. 9 is divided and made of ceramics.
3360, and also in Japanese Utility Model Publication No. 47-1657.
In No. 4, it has been announced that the joining end portion of the outer ring 9b is stepped to form an L-shaped step joint 29 as a composite plunger of a die casting machine as shown in FIG.

[0008]

The ceramic split ring as shown in FIG. 9 described above has a stable sealing effect with the sleeve 10 as in the case of the straight cylinder type plunger. In order to maintain the circularity of the ring 9a and to give a sufficient pressure to the molten metal, it is necessary from experience that the clearance between them should be 0.04 mm or less.
Therefore, it is very difficult to manufacture because it is necessary to appropriately maintain the processing accuracy of the ceramic split ring, which is the same as the processing of the inner wall of the sleeve, and the processing cost becomes enormous and precise high technology is required. However, there is a drawback that precise attention is required.

Therefore, the split ring made of ceramics or the like forms an effective sealing state with respect to the inner surface of the sleeve or the plunger groove, and it is difficult to maintain the sealing state. If this sealing state cannot be properly obtained, molding is performed. It is difficult to effectively fill the molten metal injected into the part, and the quality of the cast product obtained is degraded. Feeder speed showing the above-mentioned sealing property in die casting of aluminum-based molten metal (progressing speed of plunger after completion of filling)
Is practically known to be 40 mm / sec or less, but it is difficult to obtain such a feeder speed in a ceramic ring due to a limitation in processing accuracy.
Inevitably casting quality deteriorates. As described above, in the multiple rings provided overlapping in the radial direction, if the divided parts overlap each other, the pressurized molten metal leaks from that part,
Even if the machining accuracy of the ring and the sleeve is improved, the above feeder speed cannot be obtained. Even in the structure shown in FIG. 10, if the divided parts of the multiple rings overlap each other, the pressurized molten metal leaks similarly, and if there is a problem in the processing accuracy, as shown in FIG. It was confirmed in the experimental process that the significant melt loss 30 selectively occurs at the part, and the pressurized melt leaks from that part, or the corner of the step joint 29 is broken, and a preferable feeder speed is obtained. Absent.

Further, as shown in FIG. 12 of the prior art, the inventors of the present invention specifically describe a ring mounting groove 22 in which the bottoms are vertically orthogonal.
The pressure retention when the metal in the sleeve is pressed through the metal inflow hole of the silicon nitride sleeve is achieved by the close contact between the upper surface of the cermet ring and the upper surface of the mounting groove of the silicon nitride plunger. Regarding, regarding the standard injection condition of a 15t hot chamber, the inner pressure of the metal is 120kgf / cm ² , the plunger speed immediately before the application is 30cm / sec, and the sleeve inner diameter is 40mm.
φ, radial pressure combined ring thickness gauge 4mm, surge pressure is about 125kgf / cm ² , plunger speed is 30cm / se
The speed is reduced from c to 25 cm / sec. At this time, the upward acting force exerted on the upper surface of the plunger groove by the ring reaches 1.5 t or more over the entire circumference, and the kinetic energy that takes into consideration the acceleration generated by the further deceleration of the plunger causes the ring to move to the plunger. As the energy acts momentarily on the upper surface of the ring mounting groove and such energy acts as a shearing force for each shot, as shown in FIG. 12, cracks due to fatigue fracture from the corners of the ring mounting groove 22. It has been known that 23 occurs in the center of the plunger or outside the plunger, and this critically controls the durability of the plunger, that is, the durability of the injection mechanism of the hot chamber die casting machine.

That is, in any of the conventional cases as described above, it is difficult to obtain sufficient durability, and for example, injection of the above-mentioned standard applied setting pressure of 120 kgf / cm ² is performed using molten aluminum. When processing under the conditions, the plunger body and sleeve are made of typical silicon nitride, and when the ring is cermet,
When the inner diameter of the sleeve is 40 mmφ, the life of the plunger leading to fatigue failure under the standard injection conditions is 5000 shots on average. Further, for example, the maximum injection condition that can be adopted in a 15t hot chamber is 160kg of applied metal pressure.
Under conditions of f / cm ² and plunger speed of 90 cm / sec immediately before application, sleeve inner diameter 40 mmφ, ring thickness meter 4 mm
Then, the surge pressure was 200 kgf / cm ² , and the plunger speed was reduced from 90 cm / sec to 35 cm / sec. At this time, the upward force exerted on the upper part of the mounting groove by the ring was 2.5 tons or more. The acceleration reaches 11 times the standard injection condition, and the kinetic energy momentarily acting on the upper part of the mounting groove reaches 18 times the standard condition. Therefore, the fatigue fracture of the plunger is further promoted,
The plunger life is greatly reduced as compared with the case of the standard conditions described above, and the life is inevitably 1000 shots or less on average.

[0012]

Means for Solving the Problems The present invention has been studied to solve the problems in the prior art as described above, and clarified the technical details for improving the durability of the die casting machine injection mechanism as described above. The reason why these metal leaks are properly limited and the durability of the mechanism is significantly improved is as follows.

(1) A hot body having a plunger body composed of a sleeve and a ceramics plunger sliding in the sleeve, and a discharge part for injection-molding a molten metal pressurized by sliding of the plunger into a mold. A plunger injection mechanism for a chamber die casting, wherein an annular groove is provided on the outer periphery of the plunger and a ring is loosely mounted in the annular groove, and the molten metal pressurized in the annular groove is introduced into the inside of the plunger. A plunger injection mechanism of a hot chamber die casting machine, characterized in that a through hole is provided and a side surface of the annular groove in the flow direction of the molten metal under pressure is an inclined surface with respect to a diameter direction of the plunger.

(2) In the hot chamber die casting machine according to the item (1), the side surface of the annular groove in the flow direction of the molten metal under pressure is inclined by 30 to 50 ° with respect to the plunger diameter direction. Plunger injection mechanism.

(3) The plunger injection mechanism of the hot chamber die casting machine according to the above item (1), wherein the side surface of the annular groove in the direction of the flow of the molten metal under pressure is a curved inclined surface with respect to the diameter direction of the plunger.

(4) The ring loosely mounted in the annular groove is a multiple ring provided in the radial direction so as to overlap with each other, and each ring is divided, and the divided portion of each ring is a multiple ring. A plunger for a hot chamber die casting machine according to any one of the above items (1) to (3), characterized in that the ring is provided with a rotation preventing portion for preventing the rings from overlapping with each other. Injection mechanism.

(5) The ring loosely mounted in the annular groove is a multiple ring provided in the radial direction so as to overlap with each other, and each ring is divided, and at least among the multiple rings. The outermost ring is a multilayer ring laminated in the axial direction of the plunger body described above, and at least the divided portions of the outermost multilayer ring of the multiple rings described above are not aligned in alignment with each other. (1) to (3), characterized in that the rotation stopping portion is provided on the outermost ring.
A plunger injection mechanism of the hot chamber die casting machine according to any one of items.

[0018]

A hot body die casting plan having a plunger body consisting of a sleeve and a ceramics plunger that slides in the sleeve, and a discharge part for injecting a molten metal pressurized by sliding of the plunger into a mold. A jar injection mechanism, in which an annular groove is provided on the outer circumference of the plunger, a ring is loosened in the annular groove, and a conduction hole for guiding the molten metal pressurized in the annular groove is provided inside the plunger. The fatigue fracture of the plunger during the injection operation is significantly reduced by making the side surface of the annular groove in the flow direction of the pressurized molten metal which is inclined with respect to the diametrical direction of the plunger, and the life of the plunger is significantly improved. Compared to the case of the groove, it is several times to 10 times or more.

Since the side surface of the annular groove in the direction of the flow of the pressurized molten metal is inclined at an angle of 30 to 50 ° with respect to the diameter direction of the plunger, the impact of the corner portion of the annular groove generated when the loosely mounted rings are joined is reduced. Then, the fatigue fracture reduction of the plunger as described above is appropriately achieved.

Even when the side surface of the annular groove in the flow direction of the molten metal under pressure is a curved inclined surface with respect to the diameter direction of the plunger, the impact of the corner portion of the annular groove at the time of joining the loose ring is mitigated and the fatigue fracture occurs, as described above. A reduction is obtained as above.

The ring loosely mounted in the annular groove is a multiple ring provided in the radial direction so as to overlap with each other, and each ring is divided, and the divided portions of each ring overlap between the multiple rings. Since the ring is provided with a rotation preventing portion to prevent the above, the split portion of each ring is sufficiently provided from the flow of the molten metal that has entered from the conduction hole inside the plunger in the circumferential direction of the plunger body. It is held in a remote position. That is, the flow of metal is accurately suppressed at the ring portion to increase the injection pressure to the mold and prevent the wear of the ring due to high temperature metal leakage.

The ring loosened in the annular groove of the plunger body is a multiple ring provided in the radial direction so as to overlap with each other, and each ring is divided and formed. At least the outermost ring is a multilayer ring laminated in the axial direction of the plunger body described above, and at least the divided parts of the outermost multilayer ring of the multiple rings described above are aligned with each other in a straight line. By providing the outermost ring for preventing rotation, the ring outerwear is prevented from being worn out due to metal leakage and the effective injection into the mold is achieved at the highest level.

[0023]

EXAMPLE A concrete example of the present invention as described above will be described. The general structural relationship of the hot chamber die casting machine may be the same as that shown in FIG. An appropriate format can be adopted. In the present invention, a ceramic plunger body 8 is used as a plunger that slides in the sleeve 10, one example of which is shown in detail in FIGS. 1 to 3, and an annular groove 17 is formed on the side surface of the sliding portion. , And the ring-shaped groove 17 is loosely provided with split rings 9 and 9 in the axial direction as shown in FIG. 1, and preferably in the radial direction as shown in FIGS. 2 and 3 and FIGS. In the above, the divided rings 9'and 9 "that are combined together are attached, but the upper surface of the annular groove 17 in the flow direction of the pressurized molten metal is the inclined surface 7 with respect to the diametrical direction of the plunger 8.

As shown in FIGS. 1 to 3 and particularly FIG. 6, a central hole 16 is provided from the bottom surface of the plunger main body 8 at the center of the plunger main body 8 as described above, and the upper end of the central hole 16 is formed. Is provided with a plurality of lateral holes 18 communicating with the groove portion 17, and at least two or more of the split rings 9'and 9 "shown in FIGS. It is divided into.

That is, the split end surface 19 of the split ring 9'or 9 "may be formed parallel or inclined to the axial direction of the plunger body 8 or the sleeve 10. Even if the rigid member is excellent in corrosion resistance to high temperature molten metal such as ceramics by forming the ring 9'or 9 "by dividing it into two parts or more, each split ring has a followability in the inner surface direction of the sleeve 10. 9 ', 9 "can be obtained as a freely obtainable component.

FIG. 6 shows the specific relationship when the molten metal is pressurized using the apparatus according to the above-described embodiment of the present invention. The plunger 21 and the sleeve 1 are shown.
0 is provided vertically, the inside of the sleeve 10 is filled with the molten metal, and the plunger 21 moves up and down in the same, as described above, and each ring 9 located inside and outside the radial direction of the plunger 21. Joining surface 2 between ′ and 9 ″
2 ′ and 22 ″ are formed parallel to the axis of the plunger 21. In such a state, when the plunger 21 descends, the molten metal 15 as shown in FIG. Internal pressure is applied to the split rings 9'and 9 "through the holes 16 and the lateral holes 18 in the center of the main body 8 so that the outer split ring 9'is flexibly pressed against the inner wall of the sleeve 10 and at the same time the inner split ring 9'is pressed. 9 "
Together with the plunger body 8, it descends and seals the inclined surface 7, which is the upper surface of the annular groove 17, to prevent the metal flow between the sleeve 10 and the plunger body 8 and the metal flow from the hole 16 to achieve a sealing effect. Generate.

The inclination angle of the inclined surface 7 is as shown in FIG. 2 as well as FIG. 1, and the range of 30 to 50 ° with respect to the radial direction of the plunger 8 eliminates the damage of the portion. It was confirmed to be effective above. That is, as described above, it was confirmed that the cause of the plunger breakage was the shear stress generated in the corner portion of the annular groove 17 by the striking by the ring 9, so that the annular groove of the annular groove should be reduced in order to reduce the shear stress in the vicinity of the corner portion. As a result of repeated shape studies and experiments, it is known that it is effective to make the inclination within the above range by the finite element analysis method, and it is possible to significantly improve the durability of the plunger by it. confirmed.

Further, the inclined surface 7 as described above does not necessarily have to be formed in a straight line shape. For example, by adopting the curved inclined surface 6 using a curved surface as shown in FIG. Known to get. As an example of the inclination angle, according to the experimental result using the plunger 8 in which the angle of the linear inclined surface 7 is 45 °, the plunger life is from 5000 shots under the standard injection conditions as described above. 34000 shots and 1000 to 2000 under maximum standard injection conditions
It was known that 0 shots can be increased several times to 20 times.

Further, according to the present invention, as shown in FIG. 5, the joint surfaces 19, 19 and 1 of the split rings 9 ', 9 "are formed.
In 9 ′ and 19 ′, the outer split ring 9 ′ is thickened in the molten metal pressurizing direction of the plunger 21, and the inner split ring 9 ″ is thinned in the same direction so that the thickness is increased in the same direction. As the jar body 8 slides, the outer split ring 9'is expanded in the outer peripheral direction, and the inner split ring 9 "presses the inner surface of the annular groove 17 of the plunger body 8 so as to press the inner surface of the sleeve 10 and the plunger body 8 together. The sliding operation is performed under the condition that an effective sealing relationship is formed with respect to the inner surface of the annular groove 17 and effective injection molding is performed, and in the subsequent return stroke, the pushing and expanding action is canceled and the slide is smoothly performed. be able to.

Further, in the present invention, as shown in FIG. 7 together with FIG. 5, the split end faces 19, 19 and 19 ', 19' (that is, split portions) of the split rings 9 ', 9 "as described above are between the inner and outer multiple rings. The molten metal that does not overlap with each other and is about to be discharged from the lateral hole 18 must be the split ring 9 ″ or 9 ′.
Each ring 9 ′, 9 ″ has a rotation stopping portion 20, 20, for holding the arrangement angular position with respect to the plunger body 8 so that the discharge pressure is blocked by the sleeve 10 and the plunger 21 is reached. 20 ″ ″ is formed, whereby the detents 20, 20 are attached to the plunger body 8
Is fitted to the engaging portion 20 '. Further, in the case where the outer split ring 9'is formed of two layers, that is, the anti-rotation portion 2
0 ″ ″ is fitted to the engaging portion 20 ″.

That is, since the split rings 9'and 9 "as described above are in a loosely mounted state with respect to the groove 17 as shown in FIG. It is highly possible that the split end faces 19, 19 are displaced by the vertical movement of the split ring 9 ', and the split end faces 19, 19' are overlapped between the inner and outer multiple rings, Alternatively, it may be positioned facing the lateral hole 18 portion. That is, in such a state, the metal discharged from the lateral hole 18 causes leakage of molten metal from the gap between the split end faces of the split rings 9 ', 9 "to the back of the plunger 21, and the split rings 9', 9" are split. The partial melting loss of the end faces 19 and 19 is accelerated,
The structure of the above-mentioned rotation stop accurately prevents the effect of the feeder from being impaired.

FIG. 7 shows a plunger body 8 according to the present invention.
Is a perspective view showing an example in which a multilayer ring laminated in the axial direction of is adopted as the outermost ring,
In order to prevent the split end faces 19 and 19 of the outermost upper and lower split rings that are layered from overlapping each other, a detent portion 20 is provided for each of them. In this case, an anti-rotation portion receiving recess 20 '(see FIG. 4) is provided on the lower surface of the annular groove 17 of the plunger body 8 so as to be fitted with the anti-rotation portion 20. Further, the upper and lower rings are provided with a detent portion 20 ″ ″ on one side and a detent portion receiving recess 20 ″ with which the detent portion 20 ″ ″ is fitted on the other side.

In the case of FIG. 7, the inner ring 9 "is not an upper and lower multi-layered split ring but is an integral one, which simplifies the structure. However, in some cases, the inner ring 9" is also an outer ring. Similar to 9'and 9 ', upper and lower split rings may be used. Also in this case, the detent portion 20 is preferably provided on the lower side as in the case of FIG. 5, whereby the detent action is properly achieved, and the above-described portions are described above in the contacting portions of the split rings of the upper and lower multilayers. As described above, it is preferable that one ring is provided with the rotation stopping portion 20 ″ ′ and the other ring is provided with the receiving concave portion 20 ″. Further, the outer split ring 9 ′ and the inner split ring 9 ″ are provided at the same position. If the anti-rotation part 20 is formed on the lower surface of the annular groove 17 of the plunger body 8, only one anti-rotation part receiving recess 20 'is provided on the lower surface of the plunger body 8 to easily and effectively divide the inner and outer split rings 9',
9 "rotation can be prevented.

Further, in the present invention, in the above-mentioned case, the Young's modulus E of the material of the split rings 9 ′, 9 ″ and the ring The relationship between the thickness t, the sleeve inner diameter D and the pressure P desired to be applied to the molten metal at the time of injection is expressed by the following equation: t ³ ≦ 4.5 × 10 ² (mm) × D ² × P / E where t: each split ring Thickness (mm) E: Young's modulus of each split ring (kgf / mm ² ) D: Inner diameter of sleeve (mm) P: If the pressure applied to the molten metal during injection (kgf / mm ² ) is satisfied, Even if there is a difference in roundness and the like, the split rings 9 ′ and 9 ″ can be easily bent and come into close contact with the inner wall of the sleeve 10 to generate a good sealing effect.

That is, the feeder speed showing the sealing property (plunger speed after completion of filling) is industrially preferably 40 mm / sec or less, as compared with the conventional single ring or single-stage ring. As in the present invention, a double ring and a rotation stopper are provided to form a multi-layer ring, and further a rotation stopper is added, the sealing property is significantly improved, and the molten metal speed stably shows about 20 mm / sec. In addition, a good feeder effect can be obtained, and metal leakage can be accurately controlled.

The relationship between the Young's modulus E of the split ring and the split ring thickness t when the pressure obtained is 120 kgf / cm ² or more, which is the normal pressure for casting die cast products, is as shown by the shaded area in FIG. Met. That is, in order to obtain a pressure above a predetermined amount (120 kgf / cm ^{2 in} this case), it is necessary to ensure the sealing relationship between the sleeve and the split ring. For that purpose, if the Young's modulus of the material is small (the amount of deflection It can be seen that even if the split ring is thick, the sealing relationship becomes reliable, and if the Young's modulus is large, the sealing relationship becomes reliable by reducing the thickness.

The ring width is not particularly limited, but according to the findings obtained from various experiments, the relationship between ring width / ring diameter (plunger inner diameter) is 0.15 to 0.35. It can be said that the present invention effectively obtains the sealing property in the above formula.

As for the above-mentioned lateral hole 18, as shown in FIG. 6, the central hole 1 provided at the center of the plunger body 8
6 by disposing four or more so as to discharge on the inner surface of each split ring 9 ′, 9 ″,
A preferable discharge pressure is applied to 9 "to obtain sliding contact with the inner surface of the sleeve. The split rings are preferably divided into two or more pieces as described above, and the split end faces 19, The 19th portion is the reason why it is possible to obtain a balanced action, which is preferable to be positioned opposite each other in the middle between the lateral holes 18, 18.

[0039]

According to the present invention as described above, an annular groove is provided on the outer circumference of the plunger, and a ring is loosely mounted in the annular groove, and the annular groove is pressurized inside the plunger. A through hole for introducing the molten metal is provided, and the side surface of the annular groove in the flow direction of the molten metal under pressure is inclined with respect to the diameter direction of the plunger to significantly improve the durability of the hot chamber die casting machine injection plunger. The ring is divided, and the rotation prevention part is provided to prevent the divided part of each ring from overlapping between multiple rings, so that the metal leakage in the injection mechanism with excellent corrosion resistance to the molten metal is accurately eliminated. Further, the invention is industrially effective in that its design and manufacture are facilitated and its durability is sufficiently improved.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing an example of a plunger portion according to the present invention, showing an operating state when a plunger is pushed down together with FIGS. 2, 3 and 6 described later.

FIG. 2 is a partially cutaway side view showing another configuration of the plunger portion according to the present invention.

FIG. 3 is a partially cutaway side view showing the structure of a plunger portion according to still another embodiment of the present invention.

FIG. 4 is a side view of the plunger of the present invention with the ring removed.

FIG. 5 is a perspective view showing an example of a multiple ring provided with a rotation stopping portion according to the present invention.

FIG. 6 is a cross-sectional explanatory view showing a state of preventing metal leakage between the plunger and the sleeve according to the present invention.

FIG. 7 is a perspective view showing an example of a multi-layered multilayer ring provided with a rotation stopping portion according to the present invention.

FIG. 8 is a table showing a concrete summary of the relationship between the thickness of the ring and the Young's modulus of the material in the present invention.

FIG. 9 is an explanatory view showing a cross-sectional view of the overall structural relationship of a hot chamber die casting machine.

FIG. 10 is a perspective view showing a composite ring of a conventional plunger for a die casting machine.

FIG. 11 is a perspective view showing a state in which a melted metal leak occurs as shown in FIG.

FIG. 12 is a side view showing a fatigue fracture crack generation state in a conventional plunger.

[Explanation of symbols]

 4 Die 6 Curved inclined surface 7 Inclined surface of annular groove on side of pressurized molten metal flow direction 8 Plunger body 9 Axial split ring 9a ring (conventional) 9 ', 9 "Radial split in the present invention Ring 10 Sleeve 14 Nozzle 15 Molten aluminum 16 Central hole 17 Annular groove 18 Horizontal hole 19 Ring end face 20 Ring stop 20 'Rotation stop receiving recess 20 "Rotation stop receiving recess 20' '' Rotation stop 21 Plunger 22 Ring Mounting Groove (Conventional) 23 Fatigue Fracture Crack 29 Conventional Step Joint 30 Its Melting Part

Claims (5)

[Claims] 1. A hot chamber having a plunger body composed of a sleeve and a ceramics plunger slidable in the sleeve, and a discharge part for injecting a molten metal pressurized by sliding of the plunger into a mold. A plunger injection mechanism for die casting, in which an annular groove is provided on the outer periphery of the plunger, a ring is loosely mounted in the annular groove, and conduction is introduced inside the plunger to guide the molten metal pressurized in the annular groove. A plunger injection mechanism for a hot chamber die casting machine, characterized in that a hole is provided and a side surface of the annular groove in the flow direction of the pressurized molten metal is an inclined surface with respect to a diameter direction of the plunger. 2. The plunger injection for a hot chamber die casting machine according to claim 1, wherein a side surface of the annular groove in the flow direction of the molten metal under pressure is inclined by 30 to 50 ° with respect to the diameter direction of the plunger. mechanism. 3. The plunger injection mechanism of a hot chamber die casting machine according to claim 1, wherein a side surface of the annular groove in the flow direction of the molten metal under pressure is a curved inclined surface with respect to the diameter direction of the plunger. 4. The ring loosely mounted in the annular groove is a multiple ring that is provided overlapping in the radial direction, and each ring is divided, and the divided portion of each ring is between multiple rings. 4. The plunger injection mechanism for a hot chamber die casting machine according to claim 1, wherein the ring is provided with an anti-rotation portion for preventing the overlapping. 5. The ring loosely mounted in the annular groove is a multiple ring provided in a radial overlapping manner, and each ring is divided, and at least the ring among the multiple rings is at least the largest. The outer ring is a multi-layered ring laminated in the axial direction of the plunger body described above, and for preventing at least the divided portions of the outermost multi-layered ring of the multiple rings described above from aligning with each other in a straight line. The plunger injection mechanism of the hot chamber die casting machine according to any one of claims 1 to 3, wherein the rotation stopping portion is provided on the outermost ring.