JP3560581B2 - Nozzle device of die casting machine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a nozzle device of a hot-chamber die-casting machine or a die-casting machine such as a thixo-molding. In particular, the tip of the nozzle abuts a casting port communicating with a cavity of a mold, and a tip side of a discharge passage is provided for each cycle of molten metal supply. The present invention relates to a nozzle device of a die casting machine provided with a nozzle main body for forming a plug of molten metal.
[0002]
[Prior art]
Conventionally, a description will be given of a thixomolding machine as an example of a die casting machine. As the nozzle device, for example, a nozzle device disclosed in JP-A-11-123518 is known.
As shown in FIG. 10, the nozzle device N is configured such that a tip 20a abuts a casting port 7a communicating with a cavity 6 of a mold 5, and a plug P Is provided. At the tip end 20a of the discharge passage 21 of the nozzle body 20, there is provided a projection 15 which projects inward and prevents the plug P of the molten metal from coming out.
When molding with the mold 5, the nozzle body 20 is positioned at two positions of a contact position A contacting the casting port 7a and a separation position B separated from the casting port 7a for each cycle of molten metal supply. . When the nozzle body 20 is moved to the separation position B after the supply of the molten metal, the sprue Sa attached to the end of the product M together with the product M is cut off at the projection 15 and the product M side is separated. At the same time, a plug P of molten metal is formed at the tip end of the discharge passage 21. Thereby, the plug P is prevented from coming off due to residual pressure or the like because the projection 15 is present until the nozzle body 20 is moved to the contact position A and the molten metal is supplied. When the nozzle body 20 is moved to the contact position A and the molten metal is supplied, the plug P is pushed out by the supplied molten metal and is sent to the mold 5 side.
[0003]
[Problems to be solved by the invention]
By the way, in such a conventional nozzle device N of the die casting machine 1, since the projection 15 is provided at the tip 21a of the discharge passage 21 of the nozzle body 20, the plug P is prevented from coming off due to residual pressure or the like, but the molten metal is not melted. At the time of supply, when the plug P is pushed out by the molten metal and fed into the mold 5 side, the projection 15 becomes a resistance, and the plug P is difficult to flow out smoothly, which causes a problem of insufficient filling or noise. There was a problem. In particular, when this projection structure is applied to a hot chamber die casting machine, insufficient filling is likely to occur due to the resistance.
On the other hand, if the discharge passage 21 of the nozzle body 20 is of a straight type having no projection 15, the sprue Sa attached to the end of the product M may be cut before the tip 20a of the nozzle body 20, Since the plug P is cut inside the discharge passage 21 from the front end 20a and is not necessarily separated at a fixed position, the size of the plug P becomes indefinite accordingly. As a result, problems such as (1) cracking of the product, (2) generation of hot water wrinkles, (3) poor filling, and (4) noise during injection occur. Ruptured chill layers remain, causing nests. In addition, the gate flow rate is increased, which causes cracks. In addition, since the cross-sectional area of the plug P is larger than the cross-sectional area of any part of the runner, the flow path may be completely closed. In this case, the molten metal does not flow, and the problem is increased.
When the plug P is small, the plug P becomes thin and a hole is easily opened. When the hole is opened, air enters the discharge passage 21 of the nozzle body 20 and the molten metal in the discharge passage 21 of the nozzle body 20 returns to the pot. (1) Hot water wrinkles, (2) cracks, (3) Injection speed increases, mold erosion progresses and wear of injection parts progresses (short life). Problems such as increased noise occur.
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and makes it easy for a plug to easily flow out at the time of supplying molten metal. It is an object of the present invention to provide a nozzle device of a die casting machine in which the function can be made constant and the function is improved so that various problems do not occur.
[0004]
[Means for Solving the Problems]
In order to achieve such an object, a nozzle device of a die casting machine according to the present invention has a discharge passage for discharging a required amount of molten metal with a tip abutting on a casting port communicating with a cavity of a mold and supplying molten metal. In a nozzle apparatus of a die casting machine provided with a nozzle body for forming a plug of molten metal at a tip end of a discharge passage for each cycle of the above, an inner surface of the discharge passage of the nozzle body and a predetermined length from the tip of the nozzle body. The groove is formed at the position along the circumferential direction.
In this case, if necessary, the groove is provided continuously in the circumferential direction.
In this case, a plurality of the grooves are provided at predetermined intervals in the circumferential direction as necessary.
[0005]
Thereby, when supplying the molten metal, the plug formed in the discharge passage of the nozzle body is pushed out, and the molten metal is supplied into the cavity. In this case, the plug is pushed out through the groove of the discharge passage in the nozzle body, but flows out smoothly because there is nothing protruding in the discharge passage.
Also, when the product is removed from the mold, the sprue attached to the end of the product together with the product is cut off from the tip of the nozzle body, but a groove along the circumferential direction is formed in the discharge passage of the nozzle body. The sprue is cut off where the groove is.
Because the sprue attached to the end of the product is cut off at the groove, the sprue is not cut before the groove or cut after the groove. Is made constant.
As a result, problems such as cracking of the product, generation of hot water wrinkles, poor filling, noise at the time of injection, and the like are prevented by the large plug being formed and obstructing the flow of the hot water. In addition, it is possible to prevent the air from entering the discharge passage of the nozzle body due to the small size of the plug, which causes the occurrence of wrinkles, cracks, and an increase in the injection speed, so that the mold melts and the injection parts are worn. It is possible to prevent a situation in which progress (short life) occurs and noise during injection increases.
[0006]
Further, in the present invention, the nozzle body has a configuration in which the discharge passage of the nozzle main body is formed so as to be expanded at a predetermined expansion angle θ with the front end side toward the front end side. When the molten metal is supplied, the plug more easily passes through the discharge passage of the nozzle body, and it is possible to reliably prevent problems such as insufficient filling of the molten metal and noise.
In this case, it is effective that the predetermined angle is set to be 10 ° ≦ θ ≦ 60 °, preferably 15 ° ≦ θ ≦ 30 °. It becomes easy to pass the plug reliably.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a nozzle device of a die casting machine according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The same components as those described above will be described with the same reference numerals.
The nozzle device N according to the embodiment of the present invention shown in FIGS. 1 to 5 is applied to a hot chamber die casting machine as a die casting machine. As shown in FIG. 1, the die casting machine 1 includes a mold 5 including a fixed mold 5 a provided on a fixed board 2 and a movable mold 5 b provided on a movable board 3. The fixed platen 2 is provided with a sprue bush 7 having a casting opening 7a communicating with the cavity 6 of the mold 5. In FIG. 1, reference numeral 8 denotes a shunt provided on the movable mold 5b.
As shown in FIG. 2, the die casting machine 1 includes a molten metal supply unit 10 that supplies molten metal of the molten metal to the cavity 6 of the mold 5. The molten metal supply unit 10 includes a hot water tank 11, a plunger type pump 12 for feeding the molten metal in the hot water tank 11, and a nozzle device N according to the present embodiment connected to the pump 12 via a gooseneck 13. I have.
[0008]
The nozzle device N according to the embodiment includes a nozzle body 20 that abuts the casting port 7a of the sprue bush 7 communicating with the cavity 6 of the mold 5 and discharges a required amount of molten metal every cycle. . The nozzle body 20 is positioned for each shot of the molten metal supply at two positions, a contact position A where the tip end portion 22 contacts the casting port 7a of the sprue bush 7 and a separation position B where the nozzle body 20 is separated from the casting port 7a. Can be In addition, there is also a type in which the nozzle body 20 is always kept in contact with the casting port 7a of the sprue bush 7, and the embodiment can be applied to this type.
The nozzle body 20 has a discharge passage 21 that discharges a required amount of molten metal by contacting a casting port 7a that communicates with the cavity 6 of the mold 5 and a discharge passage 21 for each shot of molten metal supply. A solidified plug P of metal is formed on the side. The tip portion 22 of the nozzle body 20 is formed so as to have a smaller diameter than the general outer diameter and protrude into a substantially truncated cone shape, and is integrally formed with a general portion 23 of the nozzle body 20 using one type of metal material. On the other hand, the casting port 7a of the sprue bush 7 is also formed in the same substantially frustoconical shape into which the tip end portion 22 of the nozzle body 20 fits.
[0009]
As shown in FIG. 4, a reference point X at which the tip of the plug P is located is set in the discharge passage 21 of the tip 22 of the nozzle body 20. The reference point X is set at a position of a predetermined length L from the tip end 20a of the nozzle body 20.
The predetermined length L is set, for example, to L = 2 mm to 5 mm, and in the embodiment, L = 3 mm.
A groove 25 is formed on the inner surface of the discharge passage 21 of the nozzle body 20 at the reference point X along the circumferential direction. The groove 25 is provided continuously in the circumferential direction. Therefore, the sprue Sa attached to the end of the product M at the time of release is cut off at the groove 25, and the plug P is formed from the groove 25 to the rear side. Although the tip of the plug P may be flat, as shown in FIG. 4, the center is slightly cut off by the sprue Sa.
Further, the end 20a side of the groove 25 of the discharge passage 21 of the nozzle body 20 is formed so as to expand toward the front end 20a at a predetermined expansion angle θ. The predetermined expansion angle θ is set to 10 ° ≦ θ ≦ 60 °, preferably, 15 ° ≦ θ ≦ 30 °.
[0010]
Further, as shown in FIGS. 2 and 3, the nozzle device N includes a first heater 30 provided outside the tip end 22 side of the nozzle body 20 and heating the tip end 22 side, and a first heater 30 of the nozzle body 20. And a second heater 31 that is provided on the outside rearward of the nozzle 30 and heats the general portion 23 of the nozzle body 20. The first heater 30 and the second heater 31 have an electric heating element and are formed in a shape to fit the nozzle body 20. The electric heating element is formed in a linear shape and meanders uniformly.
Furthermore, the nozzle device N is provided with control means 32 for controlling the first heater 30 and the second heater 31. As shown in FIG. 6, when the nozzle body 20 is not discharging, the control means 32 controls the temperature of a portion Y of the discharge passage 21 of the tip end portion 22 of the nozzle body 20 within a predetermined length S from the reference point X to a temperature of metal. The first heater 30 and the second heater 31 are controlled so that the solidification completion temperature Ta is maintained and the temperature of the discharge passage 21 of the general portion 23 of the nozzle body 20 is maintained at a temperature equal to or higher than the metal solidification start temperature Tb. I do.
The length S from the reference point X to the inner part Y is set to S = 2 mm to 7 mm, preferably, S = 3 mm to 6 mm.
For example, as shown in the phase diagram of FIG. 7, when the metal is a magnesium alloy (aluminum 9 mass% and zinc 1 mass% added), the solidification completion temperature Ta is Ta = 468 ° C., and the solidification start temperature Tb is Tb = 596. ° C, and as shown in Fig. 6, the temperature of each part is set according to the solidification completion temperature Ta and the solidification start temperature Tb. The temperature of the discharge passage 21 of the general portion 23 of the nozzle body 20 is set to 630 ° C. which is equal to or higher than the solidification start temperature Tb of the metal.
Accordingly, as shown in FIG. 6, in the range of the length S from the reference point X to the length of the portion Y, solidified metal is reliably generated as the plug P. That is, in the range from the reference point X to the part Y, the length S is set to S = 2 mm to 7 mm, desirably, S = 3 mm to 6 mm, so that the plug P is also formed to this size. Become.
Further, as shown in FIG. 6, a solid-liquid coexistence state is formed inside the portion Y, and a molten liquid state is formed further inside.
[0011]
More specifically, the control means 32 includes a first sensor 33 composed of a thermocouple for detecting the temperature of a fitting portion on the tip end portion 22 side of the nozzle body 20 to which the first heater 30 is fitted, and a second heater 31. A second sensor 34 composed of a thermocouple for detecting the temperature of the fitting portion of the general portion 23 of the nozzle body 20 to be fitted, and the first heater 30 and the second heater 34 based on the detection results of the first sensor 33 and the second sensor 34. A temperature control unit 35 for adjusting the temperature of the second heater 31 is provided.
In the temperature control unit 35, when the nozzle body 20 is not ejected, the temperature of the portion Y, which is the ejection passage 21 of the tip end portion 22 of the nozzle body 20 and is within the predetermined length S from the reference point X, becomes the metal solidification completion temperature Ta. The target temperature is set for maintaining the temperature of the discharge passage 21 of the general portion 23 of the nozzle body 20 at a temperature equal to or higher than the solidification start temperature Tb of the metal. The detected temperature is compared with the target temperature. If there is a difference between the detected temperature and the target temperature, the current flowing through the heaters 30 and 31 is variably controlled so that the detected temperature becomes the target temperature. This control includes ON / OFF control of the first sensor 33 and the second sensor 34.
For example, as shown in the graph showing the temperature gradient of the nozzle in FIG. 8, when the above metal is a magnesium alloy (aluminum 9 mass%, zinc 1 mass% addition), the target temperature of the first heater 30 is set to 900 ° C. The target temperature of the second heater 31 is set to 800 ° C.
In FIG. 3, reference numeral 36 denotes a third sensor that detects the temperature of a portion of the nozzle body 20 on which the first heater 30 is not fitted and on which the temperature of the tip portion 22 mainly reflects.
In addition, reference numerals 37 and 38 in FIG. 3 indicate that the heaters 30 and 31 are overheated, for example, when the temperature of the nozzle body 20 is higher by 10 ° C. than the set temperature of the first heater 30 having a higher set temperature. In the above example, the monitoring sensor includes a thermocouple for detecting the temperature of 910 ° C. and stopping the operation of the heaters 30 and 31. The temperature control unit 35 has a function of stopping the operations of the first heater 30 and the second heater 31 based on the temperature detection of the monitoring sensors 37 and 38. For this reason, the life of the first heater 30 and the second heater 31 can be reliably prolonged.
[0012]
Therefore, when molding is performed by the hot chamber die casting machine 1, first, the movable die 5b provided on the movable platen 3 is positioned at the molding position with respect to the fixed die 5a provided on the fixed platen 2. Further, the nozzle body 20 of the nozzle device N is positioned from the separation position B to the contact position A, and the tip end portion 22 of the nozzle body 20 is brought into contact with the casting port 7 a of the sprue bush 7.
In this state, the pump 12 of the molten metal supply unit 10 is driven to supply the molten metal. In this case, the plug P formed on the downstream side of the groove 25 of the discharge passage 21 in the nozzle body 20 of the nozzle device N is pushed out, and the molten metal is supplied into the cavity 6. In this case, the plug P is pushed out through the groove 25 of the discharge passage 21 in the nozzle body 20, but flows out smoothly because there is nothing protruding in the discharge passage 21. In addition, the tip 20a side of the groove 25 of the discharge passage 21 of the nozzle body 20 is formed so as to expand toward the front end 20a at a predetermined expansion angle θ. It flows out smoothly.
Further, as shown in FIG. 6, the plug P is formed to have a size in the range of the length of the portion Y from the reference point X, that is, the length S is S = 2 mm to 7 mm, preferably S = 3 mm to Since it is set to 6 mm, it is formed into an appropriate size that is neither thin nor thick, and when it is extruded, it is easily broken and flows out.
Therefore, the flow of the molten metal is not hindered, and as a result, problems such as (1) cracking of the product, (2) occurrence of wrinkles, (3) poor filling, and (4) noise at the time of injection occur. The situation is prevented.
[0013]
When the molten metal is supplied into the cavity 6, the mold 5 is cooled by a cooling means (not shown), and the molten metal is solidified and formed. In this state, the nozzle body 20 of the nozzle device N is moved from the contact position A to the separation position B, and the movable die 5b is moved to release the product M. In this case, the sprue Sa attached to the end of the product M together with the product M is cut off from the tip end portion 22 of the nozzle body 20, but the discharge passage 21 of the nozzle body 20 is formed with a groove 25 along the circumferential direction. Therefore, the sprue Sa is cut off at the position where the groove 25 exists.
In this case, the temperature control unit 35 functions, and the discharge passage 21 of the distal end portion 22 of the nozzle body 20 in the non-discharge state, which is located within a predetermined length S from the reference point X where the distal end of the plug P is located. The temperature of Y is maintained at the metal solidification completion temperature Ta, and the temperature of the discharge passage 21 in the general portion of the nozzle body 20 is maintained at a temperature equal to or higher than the metal solidification start temperature Tb. As a result, a plug P having a length of about S solidified from the molten metal is formed in the discharge passage 21 of the tip end portion 22 of the nozzle body 20 from the groove 25 to the rear side.
[0014]
In this case, since the sprue Sa attached to the end of the product M is cut off at the groove 25, the sprue Sa is not cut before the groove 25 or cut after the groove 25. Therefore, the size of the sprue Sa is constant.
Also, as shown in FIG. 6, the plug P is formed to have a size in the range of the length S from the reference point X to the portion Y, that is, the length S is S = 2 mm to 7 mm, preferably, S = Since it is set to 3 mm to 6 mm, it is formed in an appropriate size that is neither thin nor thick. Therefore, the plug P is not thinned and the hole is not easily opened. The hole is opened in the plug P, air enters the discharge passage 21 of the nozzle body 20, and the molten metal in the discharge passage 21 of the nozzle body 20 returns to the pot. That situation is prevented. For this reason, (1) hot water wrinkles, (2) cracks, (3) injection speed is increased, and die melting progress and wear of injection parts (short life) occur, (4) injection. Problems such as increased noise at the time are prevented.
[0015]
Further, the function of the temperature control unit 35 causes the nozzle body 20 to be maintained at the preset target temperature and form the plug P. In this case, the first sensor 33 is fitted with the first heater 30. Since the second sensor 34 detects the temperature of the fitting portion of the general portion 23 of the nozzle body 20 on which the second heater 31 is fitted, the temperature of the fitting portion on the tip end portion 22 side of the nozzle body 20 is detected. That is, since the first sensor 33 and the second sensor 34 detect immediately below the heaters 30 and 31, the temperature immediately below the heaters 30 and 31 does not extremely decrease even if the nozzle temperature decreases. Since the difference between the temperature and the target temperature is not large, overheating of the heaters 30, 31 is prevented, the durability of the heaters 30, 31 is improved accordingly, and the life of the heaters 30, 31 is extended. So that it is able to.
[0016]
FIG. 9 shows a modified example of the nozzle device N of the die casting machine 1 according to the embodiment of the present invention. This is formed in substantially the same manner as described above, except that a plurality of grooves 25 formed on the inner surface of the discharge passage 21 of the nozzle body 20 are provided at predetermined intervals in the circumferential direction. According to this example, the same operation and effect as described above can be obtained.
[0017]
The above embodiment is an example in which the present invention is applied to a nozzle device that heats with the first heater 30 and the second heater 31. However, the present invention is not necessarily limited to this, and It may be applied to a nozzle device using a heating means. The present invention can also be applied to a thixo molding nozzle device as a die casting machine.
Further, since the solidification completion temperature Ta and the solidification start temperature Tb of the metal vary depending on the type of the metal (including the alloy), it goes without saying that the control of the control means is set according to the type of the metal.
[0018]
【The invention's effect】
As described above, according to the nozzle device of the die casting machine of the present invention, since a groove is formed along the circumferential direction at a predetermined length from the tip of the nozzle body on the inner surface of the discharge passage of the nozzle body. During the supply of the nozzle, the plug is pushed out through the groove of the discharge passage of the nozzle body, but since there is no protrusion in the discharge passage as in the conventional case, the plug flows out smoothly, and as a result, insufficient filling of the molten metal or It is possible to prevent a situation in which a trouble such as a cause of noise occurs.
Also, since the sprue attached to the end of the product is cut off at the groove, the sprue is not cut off before the groove or after the groove, so the size of the plug is kept constant. Can be done. For this reason, it is possible to prevent a situation where the plug becomes large, and it is possible to prevent a situation where problems such as cracking of a product, generation of hot water wrinkles, poor filling, noise at the time of injection, and the like occur. In addition, it is possible to prevent a situation where air is introduced into the discharge passage of the nozzle main body due to the thinning of the plug and a hole being opened, and the occurrence of hot water wrinkles, cracks, and an increased injection speed, and the mold melt-down progresses. In addition, it is possible to prevent problems such as abrasion progress of the injection parts (short life) or increase in noise at the time of injection.
[0019]
In the present invention, since the tip side of the discharge passage groove of the nozzle main body is formed so as to expand toward the front end side at a predetermined expansion angle θ, the plug forms the discharge passage of the nozzle main body when supplying the molten metal. It becomes easier to pass through, and it is possible to reliably prevent problems such as insufficient filling of molten metal and noise.
In this case, if the predetermined angle is set to 10 ° ≦ θ ≦ 60 °, desirably 15 ° ≦ θ ≦ 30 °, the plug can be easily passed without fail.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a main part of a nozzle device of a die casting machine according to an embodiment of the present invention.
FIG. 2 is a view showing an example in which the nozzle device of the die casting machine according to the embodiment of the present invention is applied to a hot chamber die casting machine.
3A and 3B are diagrams showing a nozzle device of the die casting machine according to the embodiment of the present invention, wherein FIG. 3A is a side view and FIG. 3B is a front view.
FIG. 4 is an enlarged side sectional view showing a main part of a nozzle body in a nozzle device of a die casting machine according to an embodiment of the present invention.
FIG. 5 is a front view showing a nozzle main body in the nozzle device of the die casting machine according to the embodiment of the present invention.
FIG. 6 is a graph illustrating a control example of a control unit of the nozzle device of the die casting machine according to the embodiment of the present invention.
FIG. 7 is a state diagram of a magnesium alloy as an example of a metal handled by the nozzle device of the die casting machine according to the embodiment of the present invention.
FIG. 8 is a graph showing an example of a temperature gradient of a nozzle body of the nozzle device of the die casting machine according to the embodiment of the present invention.
FIG. 9 is a front view showing a modified example of the nozzle main body in the nozzle device of the die casting machine according to the embodiment of the present invention.
FIG. 10 is a sectional view showing an example of a nozzle device of a conventional die casting machine.
[Explanation of symbols]
N Nozzle device 1 Die-casting machine 2 Fixed platen 3 Movable platen 5 Mold 5a Fixed mold 5b Movable mold 6 Cavity 7 Sprue bush 7a Casting port 8 Shunt 10 Melt supply unit 11 Hot water tank 12 Pump 13 Gooseneck 20 Nozzle body 20a Tip A Contact position B Separation position 21 Discharge passage 22 Tip 23 General part 25 Groove P Plug M Product Sa Sprue 30 First heater 31 Second heater 32 Control means 33 First sensor 34 Second sensor 35 Temperature controller X Reference point Y Inside Part S The predetermined length Ta from the reference point X to the inside part Y Metal solidification completion temperature Tb Metal solidification start temperature 36 Third sensors 37, 38 Monitoring sensors

Claims (5)

A nozzle body having a discharge passage for discharging a required amount of metal melt at a tip thereof in contact with a casting port communicating with a cavity of a mold, and forming a plug of the melt at the tip side of the discharge passage for each cycle of supply of the melt. In a nozzle device of a die casting machine equipped with
Forming a groove along the circumferential direction at a predetermined length from the tip of the nozzle body on the inner surface of the discharge passage of the nozzle body ,
A nozzle device for a die casting machine, characterized in that the nozzle body is formed so as to expand at a predetermined expansion angle [theta] with the tip side of the discharge passage of the nozzle body facing the tip side toward the tip side . 2. A nozzle device for a die casting machine according to claim 1, wherein said grooves are provided continuously in the circumferential direction. 2. The nozzle device for a die casting machine according to claim 1, wherein a plurality of the grooves are provided at predetermined intervals in a circumferential direction. 4. The nozzle device for a die casting machine according to claim 1 , wherein the predetermined spread angle θ is set to 10 ° ≦ θ ≦ 60 °. 5. The nozzle device for a die casting machine according to claim 4, wherein the predetermined spread angle θ is set to 15 ° ≦ θ ≦ 30 °.

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