JP2023012104A - Die-cast machine injector - Google Patents

Abstract

To provide a die-cast machine injector which can exactly adjust a hot water supply quantity of an injection sleeve, can eliminate a variation of the hot water supply quantity and a molten metal temperature, and can clean molten metal by removing foreign matters such as oxides.SOLUTION: Molten metal supplied into an injection sleeve is injected and charged into a metal mold cavity by a forward operation of a plunger. In a die-cast machine injector, the injection sleeve comprises a hot water quantity adjustment hole for adjusting a hot water quantity by discharging a part of the supplied hot water, is arranged within a range from a standby position of the plunger up to a hot water injection port for supplying the hot water to the injection sleeve, also arranged in at least one set, and selected according to a set height of a hot water level of the hot water quantity in the injection sleeve.SELECTED DRAWING: Figure 1

Description

The present invention relates to an injection device for a die casting machine, which injects and fills a mold cavity with molten metal fed into an injection sleeve by forward movement of a plunger.

Casting molding using molten metal such as an aluminum alloy is performed in the following procedure. First, a predetermined amount of molten metal is supplied into the injection sleeve from the molten metal holding furnace (referred to as supplying molten metal). After the completion of supplying the molten metal, the plunger is moved forward to inject and fill the molten metal in the injection sleeve into the mold cavity (referred to as an injection filling process), a pressure increasing process to increase the filling density of the molten metal, and to compensate for the solidification shrinkage of the molten metal. After the holding pressure process and the cooling process of the molten metal, the casting is taken out from the mold cavity. This casting operation is repeated until the planned number of castings is obtained.

As the hot water supply means, for example, a pressurized hot water supply means is used that presses the molten metal in a sealed molten metal holding furnace, discharges the molten metal into a hot water supply pipe, and supplies the molten metal to the injection sleeve via the hot water supply pipe. . For pressing the molten metal, means for supplying pressurized gas into the molten metal holding furnace, means for operating a piston cylinder immersed in the molten metal, and the like are used. The pressurized hot water supply means is susceptible to fluctuations in atmospheric pressure, and since the molten metal is pressed, the molten metal is discharged, the molten metal flows in the hot water supply pipe, and the hot water is supplied to the injection cylinder, multiple routes are taken. Quantities are subject to change.

Further, for example, a ladle-type hot water supply means is also widely used, in which a ladle is used to draw up molten metal from a molten metal holding furnace, and the ladle is operated to supply the molten metal to an injection sleeve. In this case, increasing the operating speed of the ladle has been studied in order to increase productivity, but molten metal leaks from the ladle and the amount of hot water supplied fluctuates. Slowing the operating speed of the ladle to reduce melt run-through causes fluctuations in the melt temperature within the ladle.

Fluctuations in the amount of supplied hot water and fluctuations in the temperature of the molten metal affect the flow of the molten metal in the injection filling process, the pressure increasing process, and the pressure holding process, and cause casting defects such as wrinkles in the molten metal, poor circulation of the molten metal, blowholes, and cast burrs. Become. In particular, unfilled castings due to insufficient supply of hot water cannot be repaired and are discarded. In addition, in order to increase the pressing force of the plunger and replenish the flow of the molten metal required for the pressure increasing process and the pressure holding process from the injection sleeve, it is common to set the amount of molten metal to be supplied so that the molten metal always remains in the injection sleeve. is. In this case, a rather large amount of hot water supply is set in anticipation of fluctuations in the amount of hot water supply, which lowers the yield of molten metal and lowers productivity.

Therefore, for example, a molten metal surface detection sensor as shown in Patent Document 1 is used to measure the surface height of the molten metal supplied into the injection sleeve to calculate the amount of molten metal to be supplied, and the injection conditions are adjusted based on the calculation result. A correction is proposed. As a result, fluctuations in the amount of hot water supplied can be corrected, and casting quality is stabilized.

JP 2020-49503

Here, the means shown in Patent Document 1 adjusts the injection conditions based on the actual measurement result of the amount of hot water supply, based on the premise that the amount of hot water supply fluctuates. However, the molten metal in the injection sleeve immediately after the hot water supply is wavy, and the height of the molten metal surface is not stable. Therefore, there is a time lag between the completion of hot water supply and the start of injection until the hot water level stabilizes. This time lag causes the temperature of the molten metal to fluctuate. Also, even if it is found that the amount of hot water supply is insufficient, the casting cannot be stopped at this point, and there is a contradiction that casting must be performed even if it is known that casting defects will occur. In other words, the method disclosed in Patent Document 1 does not solve the fluctuations in the amount of hot water supplied and the temperature of the molten metal, and the new problem of time lag results in inconsistent casting.

Therefore, the present invention provides an injection device for a die casting machine that can accurately adjust the amount of molten metal supplied to the injection sleeve, eliminate fluctuations in the amount of molten metal supplied and the temperature of the molten metal, and clean the molten metal by removing foreign substances such as oxides. intended to provide

The injection device of the die casting machine of the present invention is
In an injection device of a die casting machine, in which the forward movement of the plunger injects and fills the mold cavity with the molten metal supplied into the injection sleeve,
The injection sleeve is characterized by comprising a hot water supply amount adjusting hole for discharging part of the supplied molten metal to adjust the amount of hot water supply.

In the injection device of the die casting machine of the present invention,
It is preferable that the molten metal supply amount adjusting hole is provided within a range from the standby position of the plunger to a pouring port for supplying molten metal to the injection sleeve.

Further, in the injection device of the die casting machine of the present invention,
It is preferable that at least one or more of the hot water supply amount adjustment holes are arranged and selected according to the level of the molten metal in the injection sleeve to be set.

Furthermore, in the injection device of the die casting machine of the present invention,
It is preferable to provide a collection container for collecting and reusing the molten metal discharged from the hot water supply amount adjusting hole.

INDUSTRIAL APPLICABILITY According to the present invention, an injection device for a die casting machine is capable of accurately adjusting the amount of molten metal supplied to an injection sleeve, eliminating fluctuations in the amount of molten metal supplied and the temperature of the molten metal, and cleaning the molten metal by removing foreign substances such as oxides. can be provided.

1 is a conceptual diagram showing an injection device of a die casting machine according to the present invention; FIG. Figure 2 shows a detail of area A of the injection device shown in Figure 1; FIG. 2 is a diagram showing a method of adjusting the hot water supply amount using the injection device shown in FIG. 1; FIG. 2 is a diagram showing a hot water supply operation using the injection device shown in FIG. 1; FIG. 2 is a flowchart showing a casting method using the injection apparatus shown in FIG. 1;

Preferred embodiments for carrying out the present invention will be described below with reference to the drawings. In addition, the following embodiments do not limit the invention according to each claim. In addition, not all combinations of features described in the embodiments are essential for the solutions of the inventions according to the respective claims. In addition, in this embodiment, the scale and dimensions of each component may be exaggerated, and some components may be omitted.

[Injection device]
First, an injection device for a die casting machine according to an embodiment of the present invention will be described with reference to FIG. The injection device 100 shown in FIG. 1 includes an injection sleeve 21, an injection drive section 30, an injection control section 40, and a hot water supply amount adjustment hole LH.

The injection sleeve 21 is arranged such that its distal end communicates with the gate 14 of the mold cavity 13 formed by clamping the fixed mold 11 and the movable mold 12 supported by a mold clamping device (not shown). It is horizontally fixed at 11 predetermined positions. The rear end of the injection sleeve 21 is open, and the plunger 22 is inserted into the injection sleeve 21 from the rear end. The plunger 22 is connected to the injection driving section 30 by the rod 23 , operates the injection driving section 30 based on the control command from the injection control section 40 , and moves the plunger 22 inside the injection sleeve 21 .

Here, the action of the plunger 22 is defined as forward F toward the mold cavity 13, backward B toward the farther side, forward movement toward the front F side, and backward movement toward the rear B side. Further, the position at which the plunger 22 completes the forward movement is defined as an injection completion position FE, and the position at which the plunger 22 completes the backward movement is defined as a standby position BE. That is, the plunger 22 moves back and forth between the standby position BE and the injection completion position FE. Further, the injection drive unit 30 may use, for example, a hydraulic cylinder that is hydraulically driven, or may be a combination of a ball screw mechanism that converts rotary motion into linear motion and an electric motor. A combination of both may be used. Further, the injection sleeve 21 and the plunger 22 are provided with a cooling mechanism (not shown) including a flow path through which a cooling medium such as cooling water flows, if necessary. In addition, it is preferable to apply a lubricant to the sliding surfaces of the injection sleeve 21 and the plunger 22 in order to prevent wear and damage of the plunger 22, stabilize the sliding state, and suppress adhesion of molten metal residue. Although the injection apparatus 100 shown in FIG. 1 is based on a horizontal casting machine, it is not limited to this.

A pouring port 24 is provided on the rear B side of the injection sleeve 21 . While the plunger 22 is waiting at the standby position BE, a predetermined amount of molten metal is supplied from the pouring port 24 by the hot water supply means (not shown) (hot water supply). The injection sleeve 21 between the pouring port 24 and the standby position BE is characterized by having a hot water supply amount adjusting hole LH. Details will be described with reference to FIG.

FIG. 2 is an enlarged view of the area A shown in FIG. 1. FIG. 2(a) shows an arrangement example of the hot water supply amount adjusting holes LH, and FIG. 2(b) shows a BB cross section. As shown in FIG. 2(a), for example, three nozzles are arranged in the vertical direction at intervals on the injection sleeve 21 between the pouring port 24 and the standby position BE, and furthermore, the height is changed and the nozzles are arranged in the horizontal direction. A total of six hot water supply amount adjusting holes LH are provided, three of which are arranged at intervals. Further, the hot water supply amount adjusting hole LH penetrates the wall of the injection sleeve 21 as shown in FIG. 2(b). The plurality of molten metal supply amount adjusting holes LH play a role of adjusting the surface height of the molten metal supplied into the injection sleeve 21 . That is, the amount of hot water supply can be arbitrarily adjusted by selecting the hot water supply amount adjustment hole LH corresponding to the hot water level corresponding to the set amount of hot water supply. Therefore, it is preferable to set the number and arrangement of the hot water supply amount adjusting holes LH according to the range of the hot water supply amount to be set, and to process the hot water supply amount adjusting holes LH in the injection sleeve 21 .

[How to adjust the amount of hot water]
Next, a method for adjusting the hot water supply amount of the injection sleeve 21 using the injection apparatus shown in FIG. 1 will be described with reference to FIG. In FIG. 3, only the parts necessary for the explanation of the hot water supply amount adjustment method are selected and displayed, and the unnecessary parts are omitted from the display and explanation.

Let the state shown in FIG. 3(a) be the reference position. For example, from three vertically arranged hot water supply amount adjustment holes LH, the middle one is selected and opened. The remaining two are closed with plugs MP. A hot water amount adjusting hole LH at a position indicating a standard hot water amount to be supplied to the injection sleeve 21, which is set at the design stage of the injection device 100, is selected. Even if a larger amount of molten metal is supplied into the injection sleeve 21 than the amount of molten metal supplied from the molten metal amount adjusting hole LH, the molten metal M is discharged from the molten metal amount adjusting hole LH, and the surface height of the molten metal M in the injection sleeve 21 is It is automatically adjusted to the same position as the hot water supply amount adjusting hole LH. That is, by selecting one of the plurality of hot water supply amount adjusting holes LH, the hot water supply amount of the injection sleeve 21 is automatically adjusted.

FIG. 3(b) shows the adjustment in the direction of increasing the hot water supply amount from this reference position. A hot water supply amount adjustment hole LH corresponding to the hot water surface height of the set hot water supply amount is selected and opened. In FIG. 3B, the uppermost hot water supply amount adjustment hole LH is selected, and the remaining two holes are closed with plugs MP. Conversely, for adjustment in the direction of decreasing the amount of hot water supply from the reference position, as shown in FIG. do. In this embodiment, as shown in FIG. 2, six hot water supply amount adjusting holes LH are arranged, so that the hot water supply amount of the injection sleeve 21 can be adjusted in six steps. That is, by arranging a plurality of hot water supply amount adjusting holes LH in the injection sleeve 21 within the range between the standby position BE and the hot water pouring port 24, and selecting the hot water supply amount adjusting hole LH that matches the hot water surface height of the hot water supply amount, injection The hot water supply amount of the sleeve 21 can be adjusted accurately, and fluctuations in the hot water supply amount and molten metal temperature can also be eliminated. As a result, it is possible to reliably prevent casting defects such as wrinkles, poor circulation of hot water, blowholes, cast burrs, and poor filling due to fluctuations in the amount of hot water supplied and the temperature of the molten metal.

[Hot water supply operation]
Next, the hot water supply operation of the injection sleeve using the injection device shown in FIG. 1 will be described with reference to FIG. In FIG. 4, only the parts necessary for the explanation of the hot water supply operation are selected and displayed, and the unnecessary parts are omitted from the display and explanation. In addition, the hot water supply amount adjustment hole LH is selected at a position that matches the hot water surface height of the hot water supply amount of the injection sleeve 21 (the reference position is selected in FIG. 4), and the other two holes are closed with plugs MP. be done.

First, as shown in FIG. 4( a ), a predetermined amount of molten metal M is supplied into the injection sleeve 21 from the pouring port 24 . At this time, the amount of hot water supplied to the injection sleeve 21 is adjusted so that the molten metal M is supplied to a position higher than the hot water amount adjustment hole LH. As a result, fatal casting defects such as insufficient filling can be reliably prevented. Further, since the amount of hot water to be supplied can be accurately adjusted using the hot water amount adjustment hole LH, high accuracy is not required for the amount of hot water to be supplied in the process of supplying hot water from the pouring port 24 into the injection sleeve 21 using a ladle or the like.

The molten metal M at a position higher than the hot water supply amount adjusting hole LH is discharged out of the injection sleeve 21 through the hot water supply amount adjusting hole LH. The discharged molten metal M is collected in a collection container MH. As the molten metal M is discharged from the molten metal amount adjusting hole LH, the level of the molten metal M in the injection sleeve 21 is lowered as shown in FIG. 4(b). At the same time, the discharged molten metal M accumulates in the collection container MH. When the surface height of the molten metal M in the injection sleeve 21 reaches the same position as the molten metal supply amount adjusting hole LH, as shown in FIG. The automatic adjustment of the hot water supply amount in the sleeve 21 is finished. In FIG. 4, the hot water supply amount adjusting hole LH is always open. The hot water supply amount adjusting hole LH may be closed after the discharge of the hot water.

Further, when supplying hot water to the injection sleeve 21, the molten metal M may ripple and entrain air. Alternatively, contact with air may form an oxide film, or a mixture of lubricant and molten metal may be mixed. This entrainment of air, oxide film, and foreign matter in the mixture cause casting defects such as voids, blisters, blowholes, wrinkles, and reduced strength of the cast product. Since these foreign substances have a low specific gravity, they are often generated near the surface of the molten metal M. When excess molten metal M is discharged from the hot water supply amount adjusting hole LH, these foreign matter can be preferentially discharged, which can greatly contribute to prevention of casting defects due to contamination by foreign matter. Further, the molten metal M stored in the recovery container MH is transported to a molten metal holding furnace (not shown) and reused. Collecting the discharged molten metal M greatly contributes to improving the yield of the molten metal M. In addition, in reusing the molten metal M in which foreign matter is mixed, it is preferable to refining the molten metal M such as removing foreign matter before conveying the molten metal M to the molten metal holding furnace.

[Casting method]
Next, a casting method using the injection apparatus shown in FIG. 1 will be described with reference to FIG. First, the injection controller 40 is set to a hot water supply amount suitable for a casting to be molded. The injection control unit 40 calculates the surface height of the molten metal M in the injection sleeve 21 from the set hot water supply amount, and selects the hot water supply amount adjustment hole LH based on the calculation result. Based on the selection result of the injection control unit 40, the hot water supply amount adjustment hole LH is opened (the other hot water supply amount adjustment holes LH are closed by the plug MP). After that, the molten metal M is supplied to the injection sleeve 21 from the pouring port 24 using a hot water supply device (not shown), and the injection control unit 40 receives the information of completion of hot water supply from the hot water supply device.

By supplying hot water from the injection sleeve 21, excess molten metal M is discharged from the selected hot water supply amount adjusting hole LH. Assuming that the molten metal M is completely discharged from the molten metal amount adjusting hole LH and the amount of molten metal supplied to the injection sleeve 21 is properly adjusted automatically, the injection control unit 40 operates the injection driving unit 30 to move the plunger 22 forward. , injection filling of the molten metal M into the mold cavity 13 is performed. At this time, since the amount of hot water supplied to the injection sleeve 21 is accurately adjusted, there is no need to correct the injection conditions such as the advancing speed of the plunger 22, and stable injection filling can be performed, thereby stabilizing the quality of the casting. can be realized. After that, the molten metal M injected into the mold cavity 13 is held under pressure to compensate for solidification shrinkage due to cooling and solidification, and the molten metal M is cooled and solidified. After a preparatory process such as cleaning the mold cavity 13 and applying a release agent, the next shot is cast. Further, the discharged molten metal M is recovered in a recovery container MH, subjected to removal of impurities, etc., and then transported to a molten metal holding furnace or the like for reuse.

Thus, by a simple means of selecting the hot water supply amount adjusting hole LH provided in the injection sleeve 21, the hot water supply amount appropriate for the casting to be molded can be accurately adjusted. Moreover, the amount of hot water supplied in the injection sleeve 21 can be accurately adjusted regardless of the hot water supply accuracy of the hot water supply means such as the hot water supply device. Furthermore, the molten metal M mixed with foreign substances such as oxide films and lubricants can be preferentially removed from the injection sleeve 21, and the temperature of the molten metal in the injection sleeve 21 can be stabilized. This ensures stable production of high-quality castings.

In addition, in the injection filling process by the forward motion of the plunger 22, the range where the pressure of the molten metal M in the injection sleeve 21 increases is surely on the front side F of the pouring port 24. As shown in FIG. The pressure of the molten metal M is certainly low in the range between the standby position BE of the plunger 22 where the molten metal supply amount adjusting hole LH is arranged and the pouring port 24 . Therefore, even if a plurality of hot water supply amount adjusting holes LH are provided in the injection sleeve 21, strength such as pressure resistance of the injection sleeve 21 is not affected at all.

Further, since the hot water supply amount adjusting hole LH is provided on the rear B side of the injection sleeve 21 between the standby position BE and the pouring port 24, the plunger 22 can immediately open the hot water supply amount adjusting hole LH after the plunger 22 starts moving forward. passes through. That is, since the plunger 22 passes before the molten metal level in the injection sleeve 21 changes, the molten metal does not leak from the molten metal amount adjusting hole LH, and the molten metal amount can be maintained at a highly accurate state.

Although the preferred embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the ranges described in the above-described embodiments. Various modifications or improvements can be added to the above embodiments.

100 Injection device 11 Fixed mold 12 Movable mold 13 Mold cavity 14 Gate 21 Injection sleeve 22 Plunger 23 Rod 24 Pouring port 30 Injection drive unit 40 Injection control unit F Front B Rear FE Injection completion position BE Standby position LH Hot water supply amount adjustment Hole MP Plug M Molten metal MH Collection container

Claims (4)

In an injection device of a die casting machine, in which the forward movement of the plunger injects and fills the mold cavity with the molten metal supplied into the injection sleeve,
An injection device for a die casting machine, wherein the injection sleeve includes a hot water supply amount adjusting hole for discharging part of the molten metal supplied to adjust the amount of hot water supply. 2. The injection device for a die casting machine according to claim 1, wherein said molten metal supply amount adjusting hole is provided within a range from a standby position of said plunger to a pouring port for supplying molten metal to said injection sleeve. 3. The method according to claim 1, wherein at least one or more of said hot water supply amount adjustment holes are arranged, and are selected according to a level height of a set amount of molten metal to be supplied in said injection sleeve. die casting machine injection unit. 4. The injection device for a die casting machine according to any one of claims 1 to 3, further comprising a collection container for collecting and reusing molten metal discharged from said molten metal supply amount adjusting hole.

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