JP2021109215A - Plunger tip, injection device comprising the same and injection method - Google Patents

Abstract

To provide a plunger tip capable of improving injection performance by the suppression of the generation of burrs, an injection device comprising the same and an injection method.SOLUTION: A plunger tip 12 comprises a plunger tip body, and a first cooling chamber 121 provided at a central region in a tip part of the plunger tip body at the inside of the plunger tip body, and further comprises a second cooling chamber 122 provided along an outer circumferential face of the tip part at the inside of the plunger tip body and formed in such a manner that a cooling medium preferentially circulates than the first cooling chamber 121.SELECTED DRAWING: Figure 1

Description

The present invention relates to a plunger tip, an injection device including the plunger tip, and an injection method.

The die casting apparatus is equipped with an injection apparatus that injects molten metal and fills the mold. The injection device includes a cylindrical plunger sleeve, a plunger tip slidably installed in the plunger sleeve, and a plunger rod for sliding the plunger tip.

Here, in order to improve the injection performance, the injection device is required to make the friction between the plunger tip and the plunger sleeve as small as possible so that the plunger tip slides smoothly.

A technique relating to an injection device is disclosed in, for example, Patent Document 1. The injection device disclosed in Patent Document 1 promotes cooling of the molten metal after injection into the mold by circulating cooling water inside the plunger tip. Further, in this injection device, the cooling water is sufficiently cooled to the outer peripheral surface near the tip surface of the plunger tip, so that the outer peripheral surface near the tip surface of the plunger tip and the inner peripheral surface of the plunger sleeve come into contact with each other. It suppresses the occurrence of wear.

Japanese Unexamined Patent Publication No. 2016-68106

In the injection device disclosed in Patent Document 1, the inside of the plunger chip has a relatively late timing so that a part of the molten metal stored in the injection device does not solidify before being injected into the mold. It is necessary to start cooling the molten metal using the cooling water of. However, by the time cooling of the molten metal is started at such a timing, the molten metal has already entered the gap between the outer peripheral surface of the tip of the plunger tip and the plunger sleeve, so that the tip of the plunger tip In the gap between the outer peripheral surface and the plunger sleeve, burrs are formed by solidifying the molten metal that has entered the gap. As a result, in this injection device, the friction between the plunger tip and the plunger sleeve becomes large due to the influence of burrs, and the plunger tip cannot be slid smoothly, so that the injection performance is deteriorated. was there.

The present invention has been made in view of the above, and provides a plunger tip capable of improving injection performance by suppressing the generation of burrs, an injection device including the plunger tip, and an injection method. With the goal.

The plunger tip according to one aspect of the present invention is a plunger tip including a plunger tip main body and a first cooling chamber provided in the central region of the tip end portion of the plunger tip main body inside the plunger tip main body. Therefore, inside the plunger chip main body, a second cooling chamber is provided along the outer peripheral surface of the tip portion and is formed so that the cooling medium preferentially flows over the first cooling chamber. It is further prepared. As a result, the molten metal near the inlet of the gap can be solidified by using the second cooling chamber before the molten metal enters the gap between the outer peripheral surface of the tip of the plunger tip and the plunger sleeve. , It is possible to prevent the formation of burrs between the plunger tip and the plunger sleeve. As a result, the friction between the plunger tip and the plunger sleeve is reduced, so that the plunger tip can be slid smoothly, and as a result, the injection performance is improved.

The second cooling chamber may be formed so that the cooling medium flows at a timing earlier than that of the first cooling chamber. Further, the second cooling chamber may be formed independently of the first cooling chamber, and may be formed so that a cooling medium different from the cooling medium flowing through the first cooling chamber flows. As a result, the molten metal near the inlet of the gap can be solidified by using the second cooling chamber before the molten metal enters the gap between the outer peripheral surface of the tip of the plunger tip and the plunger sleeve. , It is possible to prevent the formation of burrs between the plunger tip and the plunger sleeve. As a result, the friction between the plunger tip and the plunger sleeve is reduced, so that the plunger tip can be slid smoothly, and as a result, the injection performance is improved.

Further, the cooling medium to be distributed to the second cooling chamber of the plunger chip may be liquid nitrogen. As a result, the molten metal can be solidified near the inlet of the gap more quickly than when cooling water is used.

The outer peripheral surface of the tip of the plunger tip may have a stepped shape. As a result, the molten metal can be quickly solidified at the stepped portion near the entrance of the gap before the molten metal enters the depth of the gap between the outer peripheral surface of the tip of the plunger tip and the plunger sleeve. ..

The injection device according to one aspect of the present invention includes a cylindrical plunger sleeve, any of the above-mentioned plunger tips, and a plunger rod that slides the plunger tip in the cylinder of the plunger sleeve. .. As a result, the molten metal near the inlet of the gap can be solidified by using the second cooling chamber before the molten metal enters the gap between the outer peripheral surface of the tip of the plunger tip and the plunger sleeve. , It is possible to prevent the formation of burrs between the plunger tip and the plunger sleeve. As a result, the friction between the plunger tip and the plunger sleeve is reduced, so that the plunger tip can be slid smoothly, and as a result, the injection performance is improved.

The plunger tip may be configured to be rotatable with the axial direction as a rotation axis. By rotating the plunger tip, it is possible to replace the hot part that has been immersed in the molten metal with the low temperature part that has not been soaked. Therefore, using the low temperature part, the outer peripheral surface of the tip of the plunger tip and the plunger The molten metal near the entrance of the gap between the sleeve and the sleeve can be solidified more quickly.

The injection method of the injection device according to one aspect of the present invention includes a cylindrical plunger sleeve, a plunger tip configured to be slidable in the cylinder of the plunger sleeve, and the plunger tip in the cylinder of the plunger sleeve. The plunger rod is provided with a sliding plunger rod, and the plunger tip includes a plunger chip main body, a first cooling chamber provided in a central region of a tip portion of the plunger tip main body inside the plunger tip main body, and the plunger. It is an injection method of an injection device having a second cooling chamber provided along the outer peripheral surface of the tip portion inside the chip main body, and the second cooling is given priority over the first cooling chamber. The plunger tip is slid using the plunger rod while circulating the cooling medium in the chamber, the step of supplying the molten metal into the cylinder of the plunger sleeve, and the step of circulating the cooling medium in the first cooling chamber. It includes a step of injecting the molten metal by moving the molten metal. As a result, the molten metal near the inlet of the gap can be solidified by using the second cooling chamber before the molten metal enters the gap between the outer peripheral surface of the tip of the plunger tip and the plunger sleeve. , It is possible to prevent the formation of burrs between the plunger tip and the plunger sleeve. As a result, the friction between the plunger tip and the plunger sleeve is reduced, so that the plunger tip can be slid smoothly, and as a result, the injection performance is improved.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a plunger tip capable of improving injection performance by suppressing the generation of burrs, an injection device provided with the plunger tip, and an injection method.

It is schematic cross-sectional view which shows a part of the injection apparatus which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view which looked at a part of the injection apparatus shown in FIG. 1 from the front. It is a figure for demonstrating operation of the injection apparatus which concerns on Embodiment 1. FIG. It is a figure for demonstrating operation of the injection apparatus which concerns on Embodiment 1. FIG. It is a figure for demonstrating operation of the injection apparatus which concerns on Embodiment 1. FIG. It is a figure for demonstrating operation of the injection apparatus which concerns on Embodiment 1. FIG. It is a figure for demonstrating operation of the injection apparatus which concerns on Embodiment 1. FIG. It is schematic cross-sectional view which shows a part of the injection apparatus which concerns on Embodiment 2. FIG. It is schematic cross-sectional view which shows a part of the injection apparatus which concerns on Embodiment 3. FIG.

Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. Further, in order to clarify the explanation, the following description and drawings have been simplified as appropriate.

<Embodiment 1>
FIG. 1 is a schematic cross-sectional view showing a part of the injection device 1 according to the first embodiment. The injection device 1 shown in FIG. 1 is a device mounted on a die casting device and for injecting molten metal such as aluminum stored in the injection device 1 to fill the mold.

Specifically, the injection device 1 slides the cylindrical plunger sleeve 11, the plunger tip 12 slidably installed in the cylinder of the plunger sleeve 11, and the plunger tip 12 in the cylinder of the plunger sleeve 11. At least the plunger rod 13 to be operated is provided.

The injection device 1 is installed so that the plunger sleeve 11 and the sprue sleeve 71 formed in the mold 70 communicate with each other. In the mold 70, a mold diverter 72 is formed in the cylinder of the sprue sleeve 71. The mold splitter 72 is formed at a position facing forward of the plunger tip 12 slidably installed in the plunger sleeve 11. Further, a runner 73 is formed between the sprue sleeve 71 and the mold splitter 72. Further, a gate 74 (not shown) and a cavity 75 (not shown) are formed at the tip of the runner 73.

For example, in the injection device 1, the plunger tip 12 is moved backward (that is, slid in the negative direction of the x-axis), and the plunger sleeve 11 is connected to the molten metal supply port 111 provided above the plunger sleeve 11. The molten metal is supplied into the cylinder. As a result, the molten metal is accumulated in the hollow portion 60, which is a space area surrounded by the plunger sleeve 11, the plunger tip 12, the sprue sleeve 71 of the mold 70, and the mold diverter 72. After that, the injection device 1 applies the pressure of the injection cylinder (not shown) to the plunger tip 12 via the plunger rod 13 to advance the plunger tip 12 (that is, slide it in the positive direction of the x-axis). ). As a result, the molten metal accumulated in the hollow portion 60 is filled in the cavity 75 via the sprue sleeve 71 of the mold, the mold diversion element 72, the runner 73, and the gate 74.

Subsequently, the cooling mechanism of the injection device 1 will be described with reference to FIG. 2 in addition to FIG.
FIG. 2 is a schematic cross-sectional view of the plunger tip 12 provided in the injection device 1 as viewed from the front. Note that FIG. 2 is a schematic cross-sectional view of the II-II'part of FIG. 1 cut out.

As shown in FIGS. 1 and 2, inside the main body of the plunger tip 12, a first cooling chamber 121 is provided in the central region of the tip end portion (the end portion on the side facing the mold splitter 72) of the plunger tip 12. It is formed. Further, inside the main body of the plunger tip 12, a second cooling chamber 122 is formed along the outer peripheral surface of the tip end portion of the plunger tip 12 (a portion close to the inner peripheral surface of the plunger sleeve 11). The second cooling chamber 122 is formed in an annular shape so as to surround the first cooling chamber 121 when viewed from the front (that is, when viewed from the x-axis direction).

Further, in the plunger tip 12, a refrigerant supply path 121a is formed from the rear end portion of the plunger tip 12 (the end on the side connected to the plunger rod 13) to the first cooling chamber 121, and the refrigerant supply path 121a is formed from the first cooling chamber 121. A refrigerant discharge path 121b is formed toward the rear end of the plunger tip 12.

Further, in the plunger tip 12, a refrigerant supply path 122a is formed from the rear end portion of the plunger tip 12 to the second cooling chamber 122, and a refrigerant discharge path 122b is formed from the second cooling chamber 122 to the rear end portion of the plunger tip 12. It is formed.

In the plunger rod 13, the refrigerant supply path 131a, from one end (the end connected to the plunger tip 12) to the other end (the end connected to the injection cylinder (not shown)), A refrigerant discharge path 131b, a refrigerant supply path 132a, and a refrigerant discharge path 132b are formed, respectively.

In the plunger tip 12, the refrigerant supply path 121a and the refrigerant supply path 131a communicate with each other, the refrigerant discharge path 121b and the refrigerant discharge path 131b communicate with each other, the refrigerant supply path 122a and the refrigerant supply path 132a communicate with each other, and the refrigerant. It is connected to one end of the plunger rod 13 so that the discharge path 122b and the refrigerant discharge path 132b communicate with each other. An injection cylinder 14 (not shown) is connected to the other end of the plunger rod 13, and a refrigerant supply source 15 and a refrigerant discharge port 16 are provided (both not shown).

The cooling medium M1 such as cooling water output from the refrigerant supply source 15 is supplied to the first cooling chamber 121 via the refrigerant supply path 131a and the refrigerant supply path 121a. After that, the cooling medium M1 supplied to the first cooling chamber 121 is discharged from the refrigerant discharge port 16 via the refrigerant discharge path 121b and the refrigerant discharge path 131b.

Further, the cooling medium M2 such as the cooling water output from the refrigerant supply source 15 is supplied to the second cooling chamber 122 via the refrigerant supply path 132a and the refrigerant supply path 122a. After that, the cooling medium M2 supplied to the second cooling chamber 122 is discharged from the refrigerant discharge port 16 via the refrigerant discharge path 122b and the refrigerant discharge path 132b.

Here, the second cooling chamber 122 is provided independently of the first cooling chamber 121, and the second cooling chamber 122 has a cooling medium M2 different from the cooling medium M1 distributed in the first cooling chamber 121. Is distributed. Therefore, the injection device 1 can freely set the timing at which the cooling medium M1 is circulated in the first cooling chamber 121 and the timing at which the cooling medium M2 is circulated in the second cooling chamber 122.

The injection device 1 circulates the cooling medium M1 through the first cooling chamber 121 and cools the molten metal accumulated in the hollow portion 60 to such an extent that it does not solidify, thereby injecting and filling the cavity of the mold 70. Cooling of the molten metal can be promoted. Further, after that, the peelability between the biscuit formed by the solidification of the molten metal and the plunger tip 12 can be improved.

However, the injection device 1 uses the first cooling chamber 121 in order to prevent the molten metal accumulated in the hollow portion 60 from solidifying in the hollow portion 60 before being injected into the cavity of the mold 70. It is necessary to start the cooling of the molten metal at a relatively late timing.

However, by the time the molten metal is started to be cooled at such a timing, the molten metal may already enter the gap between the outer peripheral surface of the tip of the plunger tip 12 and the plunger sleeve 11. There is a possibility that burrs may be formed in the gap between the outer peripheral surface of the tip portion of the tip 12 and the plunger sleeve 11 due to the solidification of the molten metal that has entered the gap. If the friction between the plunger tip 12 and the plunger sleeve 11 becomes large due to the influence of this burr, the plunger tip 12 cannot be slid smoothly, so that the injection performance is deteriorated.

Therefore, the injection device 1 distributes the cooling medium M2 to the second cooling chamber 122 before distributing the cooling medium M1 to the first cooling chamber 121, so that the outer peripheral surface of the tip end portion of the plunger chip 12 and the plunger sleeve 11 are distributed. Before the molten metal enters the gap between and, the molten metal near the entrance of the gap is solidified. As a result, the injection device 1 can prevent burrs from being formed in the gap between the outer peripheral surface of the tip end portion of the plunger tip 12 and the plunger sleeve 11, so that the plunger tip 12 can be slid smoothly. As a result, the injection performance can be improved.

Subsequently, the operation of the injection device 1 will be described with reference to FIGS. 3 to 7.
3 to 7 are diagrams for explaining the operation of the injection device 1. Note that FIG. 5 is an enlarged view of the region A of FIG.

First, as shown in FIG. 3, the plunger tip 12 is moved backward. That is, the plunger tip 12 is slid in the negative direction of the x-axis.

After that, as shown in FIG. 4, the molten metal 50 is supplied into the cylinder of the plunger sleeve 11 from the molten metal supply port 111 of the plunger sleeve 11. As a result, the molten metal 50 is accumulated in the hollow portion 60 (the space region surrounded by the plunger sleeve 11, the plunger tip 12, the sprue sleeve 71 of the mold 70, and the mold diversion element 72).

At this time, the cooling medium M2 is circulated in the second cooling chamber 122. As a result, before the molten metal 50 enters the gap between the outer peripheral surface of the tip of the plunger sleeve 11 and the plunger tip 12, the molten metal 50 near the entrance of the gap can be solidified (see FIG. 5). .. The solidified product 51 can prevent the injection device 1 from forming burrs in the gap between the outer peripheral surface of the tip end portion of the plunger tip 12 and the plunger sleeve 11.

The molten metal 50 is supplied into the hollow portion 60 at the timing when the cooling medium M2 is circulated through the second cooling chamber 122 (that is, the timing when the molten metal 50 is started to be cooled by using the second cooling chamber 122). It is preferable to be before. However, before the molten metal 50 enters the gap between the plunger sleeve 11 and the plunger tip 12, the molten metal 50 may be supplied into the hollow portion 60.

Then, as shown in FIG. 6, the plunger tip 12 is advanced. As a result, the volume of the hollow portion 60 is reduced, so that the hollow portion 60 is filled with the molten metal 50. At this time as well, the cooling medium M2 is continuously distributed in the second cooling chamber 122. As a result, even in the gap portion where the molten metal 50 in the hollow portion 60 is newly immersed in the molten metal 50 due to the rise in the molten metal level, the metal near the entrance of the gap before the molten metal 50 enters. Only the molten metal 50 can be solidified. As a result, the injection device 1 is formed with burrs (so-called gap burrs, wedge burrs, etc.) that enter the gap between the outer peripheral surface of the tip of the plunger tip 12 and the plunger sleeve 11 to increase the sliding resistance. Can be prevented.

After that, as shown in FIG. 7, the plunger tip 12 is further advanced at a high pressure while the cooling medium M1 is circulated in the first cooling chamber 121. The advancement of the plunger tip 12 shown in FIG. 6 and the further advancement of the plunger tip 12 shown in FIG. 7 may be performed stepwise or continuously. As a result, the molten metal 50 in the hollow portion 60 is injected, and in the mold 70, the cavity 75 (not shown) passes through the sprue sleeve 71, the mold diversion element 72, the runner 73, and the gate 74 (not shown). Filled in (not shown).

At this time, the cooling medium M1 is circulated in the first cooling chamber 121, and the molten metal 50 accumulated in the hollow portion 60 is cooled to such an extent that it is not significantly solidified before injection, so that the cavity of the mold 70 is injected. Cooling of the molten metal 50 filled therein can be promoted. Further, after that, the peelability between the biscuit formed by the solidification of the molten metal 50 and the plunger tip 12 can be improved.

After the product is formed by the mold 70, the processes described in FIGS. 3 to 7 are repeated.

As described above, the injection device 1 according to the first embodiment has the tip of the plunger tip 12 in addition to the first cooling chamber 121 for promoting the solidification of the molten metal after filling the cavity inside the plunger tip 12. A second cooling chamber 122 formed along the outer peripheral surface of the portion is further provided. Then, the injection device 1 circulates the cooling medium M2 in the second cooling chamber 122 before distributing the cooling medium M1 in the first cooling chamber 121, thereby causing the outer peripheral surface of the tip end portion of the plunger chip 12 and the plunger sleeve 11 to circulate. Before the molten metal enters the gap between and, only the molten metal near the entrance of the gap is solidified. As a result, the injection device 1 can prevent burrs from being formed in the gap between the outer peripheral surface of the tip end portion of the plunger tip 12 and the plunger sleeve 11, so that the plunger tip 12 can be slid smoothly. As a result, the injection performance can be improved.

In the present embodiment, the second cooling chamber 122 is formed independently of the first cooling chamber 121, and the cooling medium M2 different from the cooling medium M1 distributed in the first cooling chamber 121 is formed so as to circulate. The case has been described as an example, but the present invention is not limited to this. For example, the second cooling chamber 122 is provided along the outer periphery of the tip portion inside the plunger tip main body even if it is not independent of the first cooling chamber 121, and has priority over the first cooling chamber 121. It suffices if the cooling medium is formed so as to circulate (for example, at an early timing).

<Embodiment 2>
FIG. 8 is a schematic cross-sectional view showing a part of the injection device 2 according to the second embodiment. The injection device 2 shown in FIG. 8 further has a stepped shape 123 on the outer peripheral surface of the tip end portion of the plunger tip 12 as compared with the injection device 1.

As a result, the injection device 2 receives the molten metal at a step portion near the entrance of the gap before the molten metal 50 enters the depth of the gap between the outer peripheral surface of the tip of the plunger tip 12 and the plunger sleeve 11. 50 can be rapidly coagulated.

Since the other structures and operations of the injection device 2 are the same as those of the injection device 1, the description thereof will be omitted.

<Embodiment 3>
FIG. 9 is a schematic cross-sectional view showing a part of the injection device 3 according to the third embodiment. In the injection device 3 shown in FIG. 9, the plunger tip 12 is further configured to be rotatable with the axial direction (x-axis direction) as the rotation axis as compared with the injection device 2.

By rotating the plunger tip 12, the injection device 3 can replace the portion that has become hot due to being immersed in the molten metal 50 with the low-temperature portion that has not been immersed in the molten metal 50. Therefore, the low-temperature portion is used. Therefore, the molten metal 50 near the inlet of the gap between the outer peripheral surface of the tip of the plunger tip 12 and the plunger sleeve 11 can be solidified more quickly.

Since the other structures and operations of the injection device 3 are the same as those of the injection device 2, the description thereof will be omitted.

In the present embodiment, the case where the plunger tip 12 provided in the injection device 2 is configured to be rotatable with the axial direction as the rotation axis has been described as an example, but the present invention is not limited to this. As a matter of course, the plunger tip 12 provided in the injection device 1 may be configured to be rotatable with the axial direction as the rotation axis.

In the first to third embodiments, the case where the cooling media M1 and M2 are both cooling water has been described as an example, but the present invention is not limited to this. The cooling media M1 and M2 may be, for example, liquid nitrogen. As a result, the molten metal 50 near the inlet of the gap between the outer peripheral surface of the tip of the plunger tip 12 and the plunger sleeve 11 can be solidified more quickly. Further, the cooling media M1 and M2 may be different types of cooling media.

1 Injector 2 Injector 3 Injector 11 Plunger sleeve 12 Plunger tip 13 Plunger rod 14 Inject cylinder 15 Refrigerant supply source 16 Refrigerant outlet 50 Metal molten metal 60 Hollow part 70 Mold 71 Gate sleeve 72 Mold diverter 73 Runner 74 Gate 75 Cavity 111 Molten metal supply port 121 First cooling chamber 121a Refrigerant supply route 121b Refrigerant discharge route 122 Second cooling chamber 122a Refrigerant supply route 122b Refrigerant discharge route 123 Step shape 131a Refrigerant supply route 131b Refrigerant discharge route 132a Refrigerant supply route 132b Refrigerant discharge Path M1 Cooling medium M2 Cooling medium

Claims (8)

Plunger tip body and
A plunger tip provided with a first cooling chamber provided in the central region of the tip end portion of the plunger tip body inside the plunger tip body.
Inside the plunger chip main body, a second cooling chamber is further provided, which is provided along the outer peripheral surface of the tip portion and is formed so that the cooling medium preferentially flows over the first cooling chamber. ,
Plunger tip. The second cooling chamber is formed so that the cooling medium flows at a timing earlier than that of the first cooling chamber.
The plunger tip according to claim 1. The second cooling chamber is formed independently of the first cooling chamber, and is formed so that a cooling medium different from the cooling medium flowing through the first cooling chamber flows.
The plunger tip according to claim 1 or 2. The cooling medium to be distributed to the second cooling chamber of the plunger chip is liquid nitrogen.
The plunger tip according to claim 3. The outer peripheral surface of the tip of the plunger tip has a stepped shape.
The plunger tip according to any one of claims 1 to 4. Cylindrical plunger sleeve and
The plunger tip according to any one of claims 1 to 5, which is configured to be slidable in the cylinder of the plunger sleeve.
A plunger rod that slides the plunger tip inside the cylinder of the plunger sleeve,
Equipped with an injection device. The plunger tip is configured to be rotatable with the axial direction as a rotation axis.
The injection device according to claim 6. Cylindrical plunger sleeve and
A plunger tip configured to be slidable in the cylinder of the plunger sleeve,
A plunger rod for sliding the plunger tip in the cylinder of the plunger sleeve is provided.
The plunger tip is
Plunger tip body and
Inside the plunger tip body, a first cooling chamber provided in the central region of the tip portion of the plunger tip body, and
Inside the plunger tip body, it has a second cooling chamber provided along the outer peripheral surface of the tip portion.
It is the injection method of the injection device.
A step of distributing the cooling medium to the second cooling chamber with priority over the first cooling chamber,
The step of supplying the molten metal into the cylinder of the plunger sleeve,
A step of injecting the molten metal by sliding the plunger tip using the plunger rod while circulating the cooling medium in the first cooling chamber.
The injection method of the injection device, which is equipped with.

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