KR102677366B1 - Injection device and casting method of die cast machine - Google Patents

Abstract

By preventing the inflow of external air into the suctioned sleeve, the runaway of the molten metal is suppressed and stable suction within the sleeve is realized. The injection device 1 of the die casting machine 100 is capable of sucking the suction recess 120 defined in the tip 20 of the plunger 12 and the space 75 ahead of the front end of the tip 20. It is composed of: At a predetermined first location C1 of the sleeve 11 in the advancing/retracting direction D1 of the plunger 12 and a second location C2 spaced rearward from the first location C1, the sleeve ( The inside of the sleeve 11 can be sucked through the penetration parts 14 and 15 that penetrate 11) on the inside and outside, respectively. The opening area of the penetrating portion 15 at the first location C1 is large compared to the opening area of the penetrating portion 14 at the second location C2.

Description

Injection device and casting method of die cast machine

The present invention relates to an injection device that injects molten metal toward the cavity of a die casting machine using a plunger that can advance and retreat inside a sleeve, and a casting method using the injection device.

A technology that suctions the inside of the sleeve to suppress the occurrence of blow holes in die-cast products by efficiently increasing the vacuum level inside the sleeve where molten metal is supplied or the cavity where molten metal is injected by a plunger from within the sleeve. This is known.

For example, Patent Document 1 describes a die casting machine that suctions the inside of a sleeve using a vacuum pump.

This die casting machine is equipped with first to fourth suction devices for suctioning the inside of the sleeve and the cavity of the mold. A first suction device and a second suction device are used to suction the inside of the sleeve. The first suction device suctions the inside of the sleeve through a hole located near the pouring port into which molten metal such as aluminum alloy is injected and forward of the pouring port. The second suction device sucks the closed space formed between the constriction between the tip of the plunger and the flange of the plunger rod and the inner peripheral surface of the sleeve, thereby suctioning the inside of the sleeve through the gap between the constriction of the tip and the inner peripheral surface of the sleeve. do. Suction of the closed space formed by the constriction is effected through a through hole formed along the axial direction in the flange of the plunger rod.

In Patent Document 1, after injecting molten metal into the sleeve, when the plunger advances to the position where the pouring port is closed by the tip of the plunger, the tip in the sleeve is first removed through the hole near the pouring port by the first suction device. Gas from the space further ahead is sucked in. At this time, the gas in the cavity is also sucked through the front space within the sleeve.

Next, when the plunger advances to the position where the hole near the pouring port is closed by the tip, the process switches to suction by the second suction device. The second suction device suctions the closed space defined between the constriction of the plunger and the inner peripheral surface of the sleeve through the axial through hole of the flange of the plunger rod, thereby suctioning the space ahead of the tip in the sleeve.

After suction is started by the second suction device, suction within the cavity is started by the third suction device.

According to the description in Patent Document 1, since the inside of the cavity is sucked through the sleeve by the first suction device, the degree of vacuum in the cavity is prevented from becoming higher than the degree of vacuum in the sleeve, thereby suppressing the generation of hot water.

Japanese Patent Publication No. 2014-117741

When external air flows into the sleeve, which becomes negative pressure relative to atmospheric pressure due to suction, and the molten metal inside the sleeve runs wild, the suction hole is blocked by the adhesion of droplets of the molten metal, or molten metal components (molten metal residue) are deposited in the vacuum line. This may result in a decrease in suction efficiency.

“The molten metal flies” means, for example, that the molten metal bubbles and the molten metal surface violently shakes as a result of external air being blown in from the rear end of the sleeve forward of the tip through the radial gap between the plunger and the sleeve. . It is desired to stably suction the gas in the sleeve without the suction path being blocked or the suction efficiency being reduced due to the running around of the molten metal.

Even with the die casting machine described in Patent Document 1, there is a risk that the suction hole or pipe may be blocked by molten metal flying around during suction in the sleeve.

As described above, the purpose of the present invention is to achieve stable suction within the sleeve by preventing the inflow of external air into the suctioned sleeve and suppressing the flight of the molten metal.

The present invention is an injection device comprising a sleeve through which molten metal is supplied to the inside, and a plunger capable of advancing and retracting from the inside of the sleeve, and injecting molten metal by the plunger toward a cavity of a die casting machine. The tip of the plunger includes the inside of the sleeve. It retreats radially inward with respect to the main part and is defined by a suction recess continuous in the circumferential direction, and is configured to enable suction of the space ahead of the front end of the tip and the inside of the suction recess, in the advance/retract direction of the plunger. At a predetermined first location of the sleeve and a second location spaced rearward from the first location, the inside of the sleeve can be sucked through the penetrating portions that penetrate the sleeve on the inner and outer sides, respectively, and at the first location, The opening area of the penetrating portion is large compared to the opening area of the penetrating portion at the second location.

“Inside the suction recess” shall mean the space defined between the tip and the sleeve.

In the injection device of the die casting machine of the present invention, it is preferable that the penetrating portion at the first location is used for suction of the front space, and the penetrating portion at the second location is used for suctioning the inside of the suction recess.

In addition, the present invention is a casting method using an injection device that injects molten metal toward the cavity of a die casting machine by means of a plunger that can advance and retreat inside the sleeve into which the molten metal is supplied, wherein the tip of the plunger is attached to the inner peripheral part of the sleeve. With respect to this, a suction concave portion that retracts inward in the radial direction and continues in the circumferential direction is defined, and the sleeve has a predetermined first location in the advance/retract direction of the plunger and a second location posterior to the first location. The inside of the sleeve can be sucked through the penetrating portions that penetrate through the inside and the outside, respectively, and the opening area of the penetrating portion at the first location is larger than the opening area of the penetrating portion at the second location, and is larger than the front end of the tip. Decompressing the anterior space by suction through a penetration portion at a first location that communicates with the anterior space, and decompressing the inside of the suction concave portion by suction through a penetration portion at a second location that communicates with the interior of the suction concave portion. It is characterized by

According to the injection device of the die casting machine of the present invention and the casting method using the same, as will be described later, stable suction within the sleeve can be realized by preventing the inflow of external air into the suctioned sleeve and suppressing the flying of the molten metal.

1 is a side view of a partially broken die casting machine according to an embodiment of the present invention.
FIG. 2 is a diagram schematically showing a system for suctioning the inside of the sleeve of the injection device provided in the die casting machine shown in FIG. 1.
3 is a flow chart showing an example of a sleeve vacuum process.
FIG. 4(a) is a partially broken side view showing the main part of the injection device of the die casting machine shown in FIG. 1. (b) is a cross-sectional view of the injection device at the position IVb in (a).
Fig. 5 is a schematic diagram showing an example of penetrating portions formed at first and second locations of the sleeve, respectively.
FIGS. 6(a) to 6(c) are diagrams showing a series of steps of sleeve vacuum suction using the die casting machine shown in FIG. 1.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the accompanying drawings.

(Schematic configuration of die cast machine)

1 is a schematic side view (some including a cross-sectional view) of a die casting machine 100 equipped with an injection device 1 according to one embodiment of the present invention.

The die casting machine 100 includes a movable plate 4 on which a movable mold 22 is installed, a fixed plate 5 on which a fixed mold 21 is installed, a movable plate 4, and a fixed plate 5. It is equipped with a machine base 8 that supports, an injection device 1 that injects the molten metal 18 toward the cavity 23, and a control device 3 that controls the operation of each part of the die casting machine 100. I'm doing it.

The die casting machine 100 includes a cavity 23 and a sleeve 11 of the injection device 1 in order to suppress the generation of blowholes caused by entrapment of gas into the molten metal 18. ) Execute vacuum evacuation of the inside.

Four tie bars 7 are inserted through the insertion holes of the movable panel 4 and the fixed panel 5. The movable panel 4 moves forward and backward relative to the stationary panel 5 along the tie bar 7. By combining the fixed mold 21 and the movable mold 22 as shown in FIG. 1, a cavity (product portion) 23 is formed between them. A cast molded product is manufactured by injecting and filling molten metal 18, such as aluminum or aluminum alloy, into the cavity 23.

The movable plate 4 is provided with an extrusion plate 41 on which extrusion pins 42 are mounted.

An injection device 1 is provided on the fixed plate 5. The injection device 1 is provided with a sleeve 11 through which the molten metal 18 is supplied inside, and a plunger 12 that can advance and retreat with respect to the sleeve 11 from the inside of the sleeve 11. The injection device 1 injects the molten metal 18 toward the cavity 23 using the plunger 12.

The front end of the sleeve 11 penetrates the fixing plate 5 and is fitted with the hole 10 provided in the fixing mold 21. The rear end side of the sleeve 11 protrudes outward from the fixing plate 5 and extends horizontally toward the rear. At the rear end side of the sleeve 11, a pouring port 13 into which the molten metal 18 is injected is provided.

A hot water storage room is formed including the inside of the sleeve 11 and the hole 10 of the fixing mold 21. This storage room is connected to the cavity 23 via the runner 24 and the gate 25.

Regarding the injection device 1, the front of the moving direction of the plunger 12 when injecting the molten metal 18, that is, the side close to the cavity 23 is defined as "before", and the cavity 23 ) is defined as “after.”

The plunger 12 generally includes a plunger rod 19 and a plunger tip 20 provided on the front side of the plunger rod 19.

When injecting the molten metal 18, the plunger 12 moves forward, and after injection, it moves backward. The direction in which the plunger 12 advances and retreats (forward-backward direction) is defined as the forward-backward direction D1.

The control device 3 controls the driving of the hydraulic cylinder that advances and retreats the plunger 12 while detecting the position of the plunger 12 in the advancing and retreating direction D1 using a sensor or the like.

As an example, the position of the plunger 12 is detected by detecting a mark provided on the piston rod corresponding to the stroke of the hydraulic cylinder with a non-contact sensor.

As shown in FIG. 2, the injection device 1 is provided with a vacuum suction system 2 that suctions the inside of the sleeve 11. The vacuum suction system 2 depressurizes the inside of the sleeve 11 by suction using the vacuum pump 37 and the vacuum tank 36.

In the sleeve 11 of this embodiment, in order to enable the gas inside the sleeve 11 to be sucked by the vacuum suction system 2, there are two penetration parts ( Suction ports (14, 15) are arranged in a row in the axial direction (D1) of the sleeve (11). These penetrating portions 14 and 15 are formed in the upper part of the sleeve 11 so as to be located above the surface of the molten metal 18 supplied to the inside of the sleeve 11.

The penetrating portion 15 penetrates the peripheral wall of the sleeve 11 in the thickness direction at a predetermined first location C1 (FIG. 4(a)) of the sleeve 11 in the advancing/retracting direction D1. .

The penetrating portion 14 penetrates the peripheral wall of the sleeve 11 in the thickness direction at a second location C2 (FIG. 4(a)) spaced rearward from the first location C1.

The vacuum suction system 2 removes the gas inside the sleeve 11 through the penetration parts 14 and 15, thereby depressurizing the inside of the sleeve 11 to a predetermined vacuum degree. As the pressure inside the sleeve 11 is reduced by the vacuum suction system 2, the cavity 23 is also suctioned through the inside of the sleeve 11, so the vacuum suction system 2 is used to compress the inside of the sleeve 11 and the cavity 23. can be decompressed.

The die casting machine 100 is typically equipped with another vacuum suction system (not shown) that directly depressurizes the cavity 23 through a suction path provided in the mold.

This vacuum suction system, for example, is provided in the cavity ( 23) Directly absorbs gases such as air. In addition to air, the sucked gas may include molten metal or vapor of a mold release agent.

The control device 3 (FIG. 1) opens and closes various valves provided in the vacuum suction system of the die casting machine 100, including the vacuum suction system 2, at appropriate timings to provide control to each system. It is possible to control the suction state within the sleeve 11 and the cavity 23.

(Vacuum suction system)

With reference to FIG. 2, an example of the configuration of the vacuum suction system 2 capable of suctioning the inside of the sleeve 11 will be described. The vacuum suction system 2 has a suction path ( 51) is provided.

Each suction path 51 includes a vacuum filter 31 for vacuum exhaust from the upstream to the downstream flow of gas sucked from within the sleeve 11, a pressure gauge for detecting the pressure within the suction path 51, and a flexible gauge. (連成計), a pressure detection unit 32 such as a pressure sensor, and a selection valve 33 for selectively communicating the penetrating parts 14 and 15 to the vacuum tank 36 are provided in this order.

By opening and closing the selection valve 33, each of the penetrating portions 14 and 15 can be brought into communication with the vacuum tank 36 at the right time. Additionally, depending on the filling rate of the molten metal in the sleeve 11, either or both of the penetrating portions 14 and 15 can be communicated with the vacuum tank 36.

The inside of the vacuum tank 36 is depressurized by vacuum exhaust performed by operating the vacuum pump 37. By using the vacuum tank 36, the gas in the sleeve 11 can be sucked into the vacuum tank 36 at the right time due to the pressure difference with the vacuum tank 36 while continuously operating the vacuum pump 37.

The penetrating portions 14 and 15 are preferably in selective communication with the vacuum tank 36 depending on the position of the plunger 12 in the advancing and retreating direction D1, the state of suction from the penetrating portions 14 and 15, etc. do. The selection valves 33 corresponding to the penetrating portions 14 and 15, respectively, determine the pressure in the suction path 51 detected by the pressure detection portion 32 or the position of the plunger 12 in the forward and backward direction D1. It can be controlled to open and close depending on the situation.

When vacuum exhaust is performed by the vacuum suction system 2, the inside of the vacuum tank 36 and the sleeve 11 pass through the penetration parts 14 and 15 in which the corresponding selection valve 33 is opened. ), the gas inside the sleeve 11 flows into the suction path 51. The gas flowing into the suction path 51 passes through the vacuum filter 31, the pressure detection part 32, and the selection valve 33, and joins the flow from the other suction path 51 in the confluence/distribution part 34. , and flows into the vacuum tank 36 via the vacuum/air blow switching valve 35 and the pipe 55.

During vacuum suction, it is desirable to monitor the pressure (vacuum degree) of the suction path 51 detected by the pressure detection unit 32 to confirm that vacuum evacuation is being performed normally. For example, if some of the penetrating portions or suction paths 51 are blocked due to molten metal residue, or even if they are not blocked, the opening is narrowed due to the accumulation of molten metal residue, or the vacuum filter 31 is clogged, the pressure detection unit The pressure detected by (32) deviates from the normal range to the high side. In this case, the penetration portion or suction path 51 where the abnormality occurred, cleaning or replacement of the vacuum filter 31, etc. may be performed.

(air blow)

The penetrating portions 14 and 15 and the suction paths 51 of the penetrating portions 14 and 15 can also be used as a path for blowing pressurized air into the sleeve 11. . By air blowing, molten metal residue can be removed from the suction path 51 or the penetration parts 14 and 15.

The pressurized air supply system 9 (FIG. 2) that performs air blowing includes a compressed air source 39, which is a supply source of pressurized air, and a pressurized tank that accumulates pressure inside by air being blown in by the compressed air source 39. (38) is provided.

The vacuum suction system 2 and the pressurized air supply system 9 of the present embodiment include a vacuum/air blow switching valve 35 installed downstream of the confluence/distribution section 34 (downstream during vacuum suction). It is composed of: The vacuum/air blow switching valve 35 switches the connection point of the confluence/distribution section 34 to the vacuum exhaust pipe 55 and the air blow pipe 56, thereby performing vacuum suction and air blowing. Switch.

The suction path 51 upstream of the confluence/distribution section 34 (upstream during vacuum suction) is common during vacuum exhaust and air blowing. Therefore, air blowing and vacuum evacuation can be performed continuously without production of cast products being interrupted due to replacement of piping to the penetrating portions 14 and 15.

It is preferable that the pressure detection unit 32 is capable of detecting the pressure during air blowing in addition to the pressure during vacuum exhaustion.

When some of the selection valves 33 are closed, the flow rate of air in the penetration portion or suction path 51 corresponding to the open selection valves 33 increases, thereby increasing the cleaning effect.

Air blowing through the penetrating portions 14 and 15 is avoided just before hot water supply so that the air blow does not cause the molten metal 18 to fly around or cause trouble in hot water supply, and the molten metal 18 is stored in the sleeve 11. It can be run without being set up.

The process of sleeve vacuuming by circuit A (control circuit) from step S104 to step S114 shown in FIG. 3 represents the basic operation of the selection valve 33 corresponding to the penetration portions 14 and 15, respectively. there is.

Here, at the start of sleeve vacuum, all penetrating portions 14 and 15 are assumed to be open. After the start of the sleeve vacuum, the penetrating portions 14 and 15 are sequentially closed by the tip 20 of the plunger 12 advanced. As the plunger 12 advances, the tip 20 passes through the penetration portions 14 and 15 in turn. After the penetrating portion is closed by the second large diameter portion 202 of the tip 20, the penetrating portion is in a state where it does not communicate with either the front space 75 or the inside of the suction recess 120. It cannot be used for sleeve vacuum that suctions from the inside of the front space 75 and the suction recess 120. Even if this penetrating portion is not in communication with the front space 75 and the inside of the suction concave portion 120, the suction efficiency is maintained by suppressing the pressure increase in the vacuum tank 36, and molten metal residue is kept from the penetrating portion. To avoid entering, it is advisable to close the corresponding selection valve 33 after it is no longer available.

Therefore, as explained below, as the plunger 12 advances, each of the penetrating portions 14 and 15 is positioned at a position closed by the second large diameter portion 202 of the plunger tip 20. At the point where the plunger 12 arrives, the selection valves 33 corresponding to the penetration portions are closed one by one.

That is, as the plunger 12 advances, the selection valves 33 corresponding to the penetrating portions 14 and 15 are closed one after another.

In step S101 shown in FIG. 3, it is confirmed that the inside of the vacuum tank 36 has reached a sufficient level of vacuum, and a signal of completion of preparation is issued.

In step S102, after pouring, the plunger 12 advances and passes the position where the pouring port 13 is closed, and then the vacuum suction system 2 starts the operation of vacuum-exhausting the sleeve 11. . A predetermined position in the advancing/retracting direction D1 of the plunger 12 can be determined as the vacuum start position where vacuum suction is started. Detection of the plunger 12 reaching the set vacuum start position is performed by detecting the stroke of the hydraulic cylinder driving the plunger 12 using a non-contact sensor or the like. The arrival of the plunger 12 to each set position in the following steps is similarly detected.

In step S103, the vacuum/air blow switching valve 35 is switched to vacuum suction.

In step S104, the plunger 12 reaches the set position (FIG. 2/rear penetrating portion closed position) that closes the penetrating portion 14 (suction port).

In step S105, the selection valve 33 corresponding to the penetrating portion 14 is closed.

In step S106, the plunger 12 reaches the set position (FIG. 2/front penetrating portion occlusion position) that closes the penetrating portion 15. Here, just before the plunger 12 reaches the set position that closes the penetrating part 15, the vacuum degree of the suction path 51 corresponding to the penetrating part 15 is measured using the pressure detection unit 32. Measure.

In step S107, the selection valve 33 corresponding to the penetrating portion 15 is closed.

In step S108, the vacuum/air blow switching valve 35 is disconnected (neutral position).

In step S109, all selection valves 33 of each penetrating portion 14 and 15 are opened.

In step S110, the vacuum/air blow switching valve 35 is switched to air blow.

In step S111, the sleeve 11 is pumped through the penetrating portions 14 and 15 using the pressurized tank 38 by the pressurized air supply system 9, which has a part of the pipe in common with the vacuum suction system 2. ) Perform air blowing, which is a process that blows out air within the machine. At this time, all selection valves 33 of each penetrating portion 14, 15 may be opened, or selection valves 33 may be opened one by one in order. When the air blow is completed, the vacuum/air blow switching valve (35) is disconnected (neutral position) (S114).

In step S112, while air blowing is being performed, the pressure in each suction path 51 of the penetration parts 14 and 15 is measured by the pressure detection unit 32, and based on the pressure, the pressure in the pipe or vacuum filter is measured. Judgment is made regarding the presence or absence of blockage in (31). If a blockage occurs, an alarm is issued by a lamp or buzzer (step S113).

The selection valve 33 is preferably closed while the corresponding penetrating portion is in a closed state by the second large diameter portion 202 of the tip 20. When the second large diameter portion 202 passes through the through portion and the through portion communicates with the space 88 in FIG. 4(a) around the plunger rod 19, if the selection valve 33 is open, , there is a possibility that outside air flows into the vacuum tank 36 from the space 88 via the penetration part and the suction path 51. Since this is not intended, for example, in the step shown in (c) of FIG. 6, the selection valve 33 corresponding to the penetrating portion 14 in the closed state by the tip 20 is closed. desirable.

The operation of the selection valve 33 described above is only an example. The selection valve 33 is not only unusable due to closure of each penetration portion 14, 15, but is also properly closed based on unusability of the suction path 51, etc. due to molten metal residue, as described above. It is desirable to do so. Alternatively, it is possible to open and close the selection valves 33 corresponding to the penetration portions 14 and 15, respectively, based on the manufacturing conditions depending on the mold or product.

(Suppression of external air inflow by suction of the suction recess of the plunger tip)

The inside of the sleeve 11 sucked by the vacuum suction system 2 (FIG. 2) becomes a negative pressure with respect to atmospheric pressure. Therefore, based on the pressure difference between the outside air, which is the atmosphere outside the sleeve 11, and the gas inside the sleeve 11, the space 88 around the plunger rod 19 at the rear end of the sleeve 11 (see Figure 4). If the outside air in (a)) flows into the space 75 where the molten metal 18 in the sleeve 11 is stored through the gap between the plunger tip 20 and the sleeve 11, the molten metal 18 will bubble and scatter. Or, the surface of the hot water flows violently. If the molten metal 18 jumps like this, the amount of molten metal residue originating from the molten metal 18 in the sleeve 11 increases accordingly. Additionally, if the molten metal 18 runs wild, gas is likely to be drawn into the molten metal 18.

In this embodiment, by preventing the inflow of external air into the space 75 (FIG. 4(a)) where the molten metal 18 in the sucked sleeve 11 is stored, the runaway of the molten metal 18 is suppressed, The inside of the sleeve 11 is stably suctioned by avoiding clogging of the penetrating portions 14, 15 and the suction path 51 or a decrease in suction efficiency due to molten metal residue.

By suppressing the flying of the molten metal 18, the entrainment of gas into the molten metal 18 is suppressed, thereby preventing the occurrence of blowholes.

In this embodiment, in order to suppress external air from flowing into the front space 75 within the sleeve 11, the penetration portions 14 and 15 are used to separate the front space 75 and the plunger tip 20. Both sides of the suction recess 120 are vacuum-suctioned.

As shown in Figure 4 (a), the plunger tip 20 has a larger diameter compared to the diameter of the plunger rod 19, and the molten metal stored in the sleeve 11 when the plunger 12 is advanced ( 18) is extruded toward the front.

The plunger rod 19 is coupled to the plunger tip 20 by a tip joint 20D.

The plunger tip 20 has a suction recess ( It is provided with a second large diameter portion 202 that partitions 120). The diameter of the plunger tip 20 at the position of the suction recess 120 is small compared to the diameters of the first large-diameter portion 201 and the second large-diameter portion 202. Therefore, the section between the first large-diameter portion 201 and the second large-diameter portion 202 in the axial direction D1 of the plunger tip 20 is called the small-diameter portion 203. On the outer peripheral portion 203A of the small diameter portion 203, a double width 203B (FIG. 4(b)) that engages with a tool for fastening work is formed.

As shown in FIGS. 4(a) and 4(b), the suction recess 120 is retracted inward in the radial direction D2 with respect to the inner peripheral portion 11A of the sleeve 11, and extends in the circumferential direction. It is continuous with (D3).

This suction recess 120 is continuous over the entire circumference of the plunger tip 20. Therefore, a gap having an annular cross-section is formed between the inner peripheral portion 11A of the sleeve 11 and the outer peripheral portion 203A of the small diameter portion 203 corresponding to the suction recess 120.

In this embodiment, when the plunger 12 advances with respect to the sleeve 11, there is a space 75 in front (on the cavity 23 side) of the front end 20A and a recess for suction 120 behind it. ), both the space 75 and the inside of the suction recess 120 are depressurized with respect to atmospheric pressure by suctioning from both sides of the inside of the vacuum suction system 2.

According to the suction inside the front space 75 and the suction recess 120, a space (suction) is located behind the front space 75 in the sleeve 11 and has the same pressure as the front space 75. By allocating the inner side of the concave portion 120, it is possible to prevent external air outside the sleeve 11 from flowing into the front space 75 within the sleeve 11. This means that there is no difference between the pressure P1 inside the suction recess 120 and the pressure P2 in the space 75, but even if there is a pressure difference, the pressure difference P1-P2 is atmospheric pressure P0. ) and the pressure P2 of the front space 75 are sufficiently small compared to the difference (P0-P2), thereby suppressing outside air from flowing into the front space 75 through the inside of the suction recess 120. Because it becomes.

When the plunger 12 moves forward, both the front space 75 and the inside of the suction recess 120 are continuously sucked, and while the plunger 12 is sucked, the front space 75 stores the molten metal 18. It can suppress the inflow of external air into. While suctioning the front space 75, the inside of the suction recess 120 is continuously suctioned, thereby suppressing the inflow of external air into the front space 75 at all times while the front space 75 is being suctioned. It is desirable.

In this embodiment, based on the configuration of the vacuum suction system 2 (FIG. 2) described above, suction inside the front space 75 and the suction recess 120 is performed by one vacuum suction system 2. can be in charge. The gas sucked from the front space 75 and the gas sucked from the inside of the suction recess 120 pass through the same vacuum tank 36 and are sucked by the same vacuum pump 37.

Therefore, compared to the case where the vacuum suction system is provided separately in the front space 75 and the suction recess 120, the cost of devices such as the vacuum pump 37 and the vacuum tank 36 can be reduced. . In addition, since the number of vacuum suction systems is small, there are few inspection points for gas leakage (electrical leakage), so inspection work efficiency is good.

However, it is also permitted for the front space 75 and the inside of the suction recess 120 to be suctioned through different systems.

In order to suppress the inflow of external air into the front space 75, the inside of the suction recess 120 is sucked, and the outer peripheral portion 20C of the plunger tip 20 (FIG. 4(b)) and the sleeve are It is effective to seal the gap between the inner peripheral portions 11A of (11) using an appropriate seal member, tip lubricant, etc.

(Composition and utility of penetrating part)

However, the injection device 1 of the present embodiment has penetrations that penetrate the sleeve 11 at the first location C1 and the second location C2 of the sleeve 11 in the advance/retract direction D1, respectively. The inside of the sleeve 11 can be sucked through the portions 14 and 15, and the opening area of the penetrating portion 15 at the first location C1 is equal to that of the penetrating portion 14 at the second location C2. The main feature is that it is large compared to the opening area of ).

If the length in the advancing/retracting direction D1 is short, as in the sleeve 11 shown in FIG. 4, the front space 75 is expanded by arranging penetrating portions at many locations in the sleeve 11 at intervals in the advancing/retracting direction D1. In some cases, it is difficult to secure a sufficient opening area related to suction efficiency. In this case as well, by providing a penetrating portion with a large opening area at an arbitrary location, vacuum suction within the sleeve 11 is achieved, and further vacuum suction of the cavity 23 communicating with the inside of the sleeve 11 is achieved. To achieve this, sufficient opening area can be secured.

Hereinafter, the penetrating part 15 at the first location C1 will be referred to as the front penetrating portion 15, and the penetrating portion 14 at the second location C2 will be referred to as the rear penetrating portion 14.

The front penetrating portion 15 is used for suction of the space 75 ahead of the front end 20A of the tip 20. The rear penetrating portion 14 is used for suction inside the suction recess 120.

FIG. 5 is a plan view showing an example of the shape of the front penetrating portion 15 and the rear penetrating portion 14. As shown in FIG. 5 by a solid line or a two-dashed chain line, the front penetrating portion 15 may have an appropriate shape as long as the opening area is enlarged with respect to the rear penetrating portion 14.

The front penetrating portion 15 indicated by a solid line in FIG. 5 is a hole representing a circular opening. The same applies to the rear penetration portion 14 shown in FIG. 5. Since this front penetrating portion 15 has a larger opening diameter than that of the rear penetrating portion 14, the opening area A1 of the front penetrating portion 15 is larger than the opening diameter of the rear penetrating portion 14. It is large compared to the area (A2).

The front penetrating portion 15 shown by the two-dot chain line in FIG. 5 is configured in the shape of an elongated oval in the circumferential direction D3 of the sleeve 11 with respect to the rear penetrating portion 14 shown in FIG. 5 . The opening area A1 of the front penetrating part 15 is also large compared to the opening area A2 of the rear penetrating part 14.

In addition, the front penetrating portion 15 may have an oval shape that is long in the axial direction (advance/retract direction D1) of the sleeve 11 with respect to the rear penetrating portion 14.

The front penetrating portion 15 and the rear penetrating portion 14 are not limited to a circular or elliptical shape, but may be of an appropriate shape such as an oval or rectangular shape, taking into account connection with the suction pipe.

Each of the front penetrating portion 15 and the rear penetrating portion 14 does not necessarily have to consist of only one hole. As long as a predetermined opening area can be given to each of the front penetrating portion 15 and the rear penetrating portion 14, each of the front penetrating portion 15 and the rear penetrating portion 14 can be any number of one or more. It can be composed of holes.

For example, for the rear penetrating portion 14 consisting of one circular hole, it is possible to configure the front penetrating portion 15 with two or more circular holes having the same diameter as the hole of the rear penetrating portion 14. do. In this case, a set of two or more holes corresponds to the front penetrating portion 15, and an opening area of the front penetrating portion 15 that is twice or more than that of the rear penetrating portion 14 can be obtained.

If the total opening area of one or more holes constituting the front penetrating part 15 is larger than the total opening area of one or more holes constituting the rear penetrating part 14, the front penetrating part 15 and the rear An appropriate number of holes can be provided in each of the penetrating portions 14.

The plurality of holes constituting the front penetrating portion 15 can be appropriately arranged regardless of whether they are regular or irregular. For example, a plurality of holes constituting the front penetrating portion 15 may be aligned in the circumferential direction D3 of the sleeve 11. In this case, a plurality of holes may be arranged over a predetermined angle range on both sides of the 12 o'clock position, which is the top of the sleeve 11, so that each hole is located above the surface of the molten metal 18.

By the vacuum suction system 2 (FIG. 2), the front space 75 is suctioned through the front penetrating portion 15, and the inside of the suction recess 120 is suctioned through the rear penetrating portion 14. At this time, the front space 75 to be sucked through the front penetrating portion 15 with a larger opening area can be efficiently depressurized to a lower pressure compared to the inside of the suction concave portion 120.

In that case, the inflow of external air into the front space 75 is suppressed by suction of the inside of the suction recess 120 through the rear penetration part 14, thereby preventing the molten metal 18 from running wild, thereby preventing the molten metal 18 from running wild. The occurrence of blowholes can be suppressed by reducing the pressure in the front space 75 to a desired vacuum level while avoiding blockage of the penetrating portions 14, 15 or the suction path 51 or a decrease in suction efficiency due to this. .

According to this embodiment, in conventional sleeve vacuum suction where the suction hole or path is likely to suddenly become blocked due to molten metal residue, stable suction within the sleeve 11 is achieved by avoiding blockage of the suction path or a decrease in suction efficiency. can be realized. Therefore, since there is no need to perform vacuum suction by suppressing the vacuum degree or molten metal filling rate within the sleeve in order to avoid blockage of the path, etc., it is possible to realize sleeve vacuum suction with a high vacuum degree and high filling rate.

(Sleeve vacuum aspiration process)

Referring to Figures 6 (a) to (c), sleeve vacuum suction is performed while suctioning the inside of the front space 75 and the suction recess 120 using the two penetration parts 14 and 15. An example of the process is explained.

In this embodiment, when the plunger 12 advances with respect to the sleeve 11, the front penetrating portion 15 at the first location C1 and the rear penetrating portion 14 at the second location C2 are used. , Suction is continuously performed from the inside of the space 75 (on the cavity 23 side) ahead of the front end 20A and the suction recess 120 behind it.

In order to secure sufficient suction time and raise the inside of the front space 75 and the suction concave portion 120 to a sufficient degree of vacuum, as shown in (a) of FIG. 6, the second large diameter portion 202 It is preferable to start sleeve vacuum suction when the front end passes through and blocks the pouring port 13, and the inside of the suction concave portion 120 communicates with the rear penetrating portion 14 at the second location C2. do.

However, in this embodiment, both the front space 75 and the inside of the suction recess 120 may be vacuum-suctioned in a state in which the forward movement of the plunger 12 is temporarily stopped.

In order to suppress external air outside the sleeve 11 from flowing into the front space 75 through the inside of the suction recess 120, prior to the start of vacuum suction of the front space 75, the suction recess is It is desirable to initiate vacuum suction of the inside of the unit 120.

In the state shown in (a) of FIG. 6, both the front space 75 and the inside of the suction recess 120 are connected to the sleeve ( 11) It is partitioned within. In addition, the front penetrating part 15 communicates with the front space 75, and the rear penetrating part 14 communicates with the inside of the suction recess 120.

Therefore, as shown by the solid arrow in FIG. 6(a), suction is possible from the front space 75 through the front penetration portion 15 by the vacuum suction system 2 (FIG. 2). As indicated by the broken arrow in Figure 6 (a), suction is possible inside the suction recess 120 by the vacuum suction system 2 through the rear penetration portion 14.

Thereafter, until the front penetrating portion 15 is closed by the first large diameter portion 201 of the tip 20 of the plunger 12 advanced, as shown in FIG. 6(b), Vacuum suction can be continued both inside the front space 75 and the suction recess 120.

As shown in (b) of FIG. 6, even after the front penetrating portion 15 is closed by the first large diameter portion 201, the gap 89 between the first large diameter portion 201 and the sleeve 11 ( While the front space 75 is sucked from the front penetrating portion 15 through (c) in FIG. 6, the inside of the suction recess 120 is also sucked from the rear penetrating portion 14 through the gap 90. You can. Even after suction from the front space 75 is completed, the inflow of external air into the front space 75 can be continuously suppressed by suctioning from the inside of the suction recess 120.

In this embodiment, the penetrating portion for suction corresponding to the inside of the front space 75 and the recessed portion for suction 120, respectively, is located at the first location C1 of the sleeve 11 in the forward and backward direction D1, and It is provided in two locations in the second location (C2). Therefore, at least until just before the front penetrating portion 15 is closed, the rear penetrating portion ( It would be good if suction could be continued from the inside of the suction recess 120 through 14).

As shown in (b) of FIG. 6, if the front penetrating portion 15 is closed by the first large diameter portion 201, at least the front penetrating portion 15 directly communicating with the front space 75 The vacuum suction performed through is terminated. In the state shown in Figure 6 (b) or (c), the inside of the suction concave portion 120 does not necessarily need to be in communication with the front penetrating portion 15.

From the above, according to the present embodiment, the inside of the suction recess 120 and Direct vacuum suction inside the suction recess 120 can be continued through the communicating rear penetrating portion 14.

However, interruption of vacuum suction is permitted as long as the time is short enough not to affect the occurrence of blowholes due to the flying of the molten metal 18 or the blockage of the penetrating part due to molten metal residue.

That is, as long as the inflow of external air is suppressed and sleeve vacuum suction is stably established, any of the inside of the front space 75 and the suction concave portion 120 during a part of the period from the start to the end of sleeve vacuum suction. Suction on one or both sides may be interrupted, or the timing of the start or end of sleeve vacuum suction inside the front space 75 and the suction recess 120 may be different.

In the case where the dimension Lp0 of the suction recess 120 in the advancing/retracting direction D1 is smaller than the dimension Ls3 in the advancing/retracting direction D1 of the gap between the penetrating parts 14, 15, the figure is Although omitted, when the front penetrating part 15 is closed by the first large-diameter part 201 and the rear penetrating part 14 is closed by the second large-diameter part 202, the suction recess 120 ), vacuum suction inside the suction recess 120 may be interrupted due to the absence of a penetrating portion communicating with the inside. Even if the molten metal 18 flies at this time, since there are no open penetration parts other than the penetration parts 14 and 15, there is at least no fear of the penetration part being blocked by the scattering of the molten metal 18.

In addition to the above, as long as it does not deviate from the main point of the present invention, it is possible to select the configurations exemplified in the above embodiments or change them to other configurations as appropriate.

A: Circuit A1, A2: Opening area
C1: 1st location C2: 2nd location
D1: Advance/retract direction D2: Diameter direction
D3: Circumferential direction P0: Atmospheric pressure
P1, P2: Pressure 1: Injection device
2: Vacuum suction system 3: Control device
4: Movable panel 5: Fixed panel
7: tie bar 8: machine base
9: Pressurized air supply system 10: Hole
11: Sleeve 11A: Inner peripheral part
12: plunger 13: pouring port
14: Rear penetrating portion (second penetrating portion)
15: Front penetration part (first penetration part) 18: Molten metal
19: plunger rod 20: plunger tip
20A: Front end 20C: Outer periphery
20D: Tip joint 21: Fixed mold
22: Movable mold 23: Cavity
24: Runner 25: Gate
27: chill vent 28: connector
31: vacuum filter 32: pressure detection unit
33: Selection valve 34: Confluence/distribution unit
35: Vacuum/air blow conversion valve 36: Vacuum tank
37: vacuum pump 38: pressurized tank
39: compressed air source 41: extrusion plate
42: extrusion pin 51: suction path
55, 56: Piping 75: Front space
88: space 89, 90: gap
100: die cast machine 120: recess for suction
201: 1st Daegyeongbu 202: 2nd Daegyeongbu
203: small diameter part 203A: outer peripheral part
203B: Width of both sides

Claims (3)

An injection device comprising a sleeve into which molten metal is supplied, a plunger capable of advancing and retracting from the inside of the sleeve, and injecting the molten metal by the plunger toward a cavity of a die casting machine,
The tip of the plunger is defined with a suction recess that retreats radially inward with respect to the inner peripheral portion of the sleeve and continues in the circumferential direction,
Configured to enable suction of the space ahead of the front end of the tip and the inside of the suction concave portion,
When the plunger advances, it penetrates the sleeve at a predetermined first location in the advance/retract direction of the plunger and at a second location spaced rearward from the first location, respectively, across the inner and outer sides of the sleeve. The inside of the sleeve can be sucked through one penetration part,
Characterized in that the opening area of the penetrating portion at the first location is larger than the opening area of the penetrating portion at the second location.
Injection device of die casting machine. According to claim 1,
The penetrating portion at the first location is used for suction of the anterior space,
The penetrating portion at the second location is used for suction inside the suction recess.
Injection device of die casting machine. In the casting method using an injection device that injects the molten metal toward the cavity of the die casting machine by means of a plunger that can advance and retreat inside the sleeve into which the molten metal is supplied,
The tip of the plunger is defined with a suction recess that retreats radially inward with respect to the inner peripheral portion of the sleeve and continues in the circumferential direction,
In a predetermined first location of the sleeve in the advance/retract direction of the plunger, and at a second location rearward of the first location, penetrations that penetrate the sleeve through the inner and outer sides, respectively, when the plunger advances. The inside of the sleeve can be sucked through the part,
The opening area of the penetrating portion at the first location is larger than the opening area of the penetrating portion at the second location,
The space in front is decompressed by suction through the penetrating portion at the first location that communicates with the space ahead of the front end of the tip, while the penetrating portion at the second location communicates with the inside of the concave portion for suction. Characterized in that the inside of the suction recess is decompressed by suction.
Casting method.