JPH031100B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is a horizontal clamping vertical casting type die casting machine, in which an injection sleeve, which is a movable sleeve, is inserted into an injection hole of a mold to inject molten metal into the injection sleeve. This relates to a casting method that involves injection into the cavity of a mold.

[Prior art] Casting using a die-casting machine has been widely used as a method for manufacturing precision products in large quantities, but this type of casting involves filling the cavity of a mold with molten metal at high speed and high pressure. Therefore, the gas in the cavity may not escape sufficiently, and may mix with molten metal and remain in the product as cavities, so it is sometimes unsuitable for products where integrity without cavities is important.

In order to eliminate such inconveniences, the present applicant has proposed a method for removing gas from the mold cavity during casting using Utility Model Publication No. 60-19807 etc., which eliminates gas entrainment and provides a sound die-cast product. We developed and proposed a degassing device.

This device is equipped with a gas vent valve in the gas exhaust path leading from the mold cavity to the outside of the mold, and when the valve is open, the molten metal is injected into the cavity. The inertial force of the large mass of the molten metal that has entered the gas exhaust passage from inside the cavity when the gas has been discharged through the gas discharge passage is applied to the valve to close it, thereby blocking the outflow of the molten metal. Therefore, the gas inside the mold can be reliably and easily vented.

The applicant has also developed a reduced-pressure or vacuum-type die-casting method and an apparatus therefor, in which the gas in the mold cavity is actively exhausted by connecting the gas exhaust path to a vacuum generator. This reduced pressure die casting method reduces the pressure by suctioning an amount of gas from the outside that is greater than the amount of gas that flows into the cavity from outside the mold through the gap, thereby eliminating gas from inside the mold. It can be made more reliable.

[Problems to be Solved by the Invention] However, in such a conventional injection device, if injection is performed while the inside of the mold cavity is evacuated only from above, the fixed sleeve at the bottom of the mold and the injection sleeve will be damaged. Since outside air is sucked in from the joint, between the injection sleeve and the plunger tip, and from the mating surface that is the half of the fixed sleeve at the bottom of the mold, solidification occurs at the tip of the plunger tip when injection starts. When the layer was broken during injection, air from the joints of the injection sleeve entered the molten metal and entered the mold cavity together with the molten metal. That is,
As shown in FIG. 12, which is a cross-sectional view of the injection sleeve insertion part, half-shaped fixed sleeves 5 and 5a are fitted into the injection holes 4 of the molds 3 and 3a, each having a cavity 1 and a constricted part 2. Along with being worn,
Injection sleeve 7 supplied with molten metal 6 for injection
is charged into the inner hole of the injection sleeve 7,
A plunger tip 8 is slidably inserted. At the start of injection, the molten metal 6 solidifies on the molten metal contacting end surface of the plunger tip 8 and the inner surface of the injection sleeve 7 that is continuous therewith, resulting in a solidified layer 9.
This solidified layer 9 is pushed up by the plunger 8 rising for injection, compressed and crushed between the flat surface 10 in front of the constriction 2 and the end face of the plunger tip 8, and is crushed inside the cavity 1. into the fixed sleeves 5, 5a without entering the
It remains with the biscuit which is the solidified product of the molten metal 6,
When the product is taken out, it is separated from the constriction 2 integrally with the biscuit.

However, in the above-mentioned conventional injection device, when the gas in the cavity 1 is vacuum-sucked, the gap between the injection hole 4 of the mold 3 and the injection sleeve 7 inserted therein, and the gap between the injection sleeve 7 and the plunger tip 8 are removed. Air is sucked in as shown by the arrows in the figure from the sliding surfaces between them and the mating surfaces of the fixed sleeves 4 and 5, and this air enters between the inner surfaces of the fixed sleeves 5 and 5a and the solidified layer 9. When the coagulated layer 9 is compressed by the plunger tip 8 and hits the flat surface 10, the coagulated layer 9 is broken one after another as shown by the reference numeral 9A in the figure, and the air that has entered is released from between the broken coagulated layer pieces 9A. It enters the molten metal and enters the cavity 1 through the constriction 2 through the molten metal. This air and the molten metal alternately pass through the constricted portion 2, which disturbs the flow of the molten metal, resulting in a drawback that a high-quality cast product cannot be obtained.

[Means for Solving the Problems] In order to solve these problems, in the present invention, air is injected into the cavity from the air inlet portion located below the upper surface of the molten metal at least 0.1 seconds before the start of vacuum suction into the cavity. A method of casting molten metal using vacuum suction was adopted.

More specifically, the mold cavity is connected to a vacuum source via a degassing device, the outer peripheral surface of the plunger tip is connected to the vacuum source, and a plunger is provided at the vertical separation surface between the movable mold and the fixed mold. The fixed sleeve and the injection sleeve insertion hole are separated from the separation surfaces of the fixed sleeve and the injection sleeve insertion hole on both outer sides of the half-split fixed sleeve and the injection sleeve insertion hole below the fixed sleeve. A horizontal clamping vertical casting die-casting machine was used, in which parallel vertical grooves were provided and an annular groove was provided on the inner peripheral surface of the injection sleeve insertion hole, and these vertical grooves and annular groove were connected to a vacuum source. At least 0.1 seconds before the start of vacuum suction in the mold cavity, vacuum is applied from the outer circumferential surface of the plunger tip and the vertical groove and the annular groove, and then, while vacuum suction is applied from the mold cavity, the molten metal is removed. Casting is carried out, and at the time of vacuum suction, the degree of vacuum suction from the outer peripheral surface of the plunger tip and the vertical groove and the annular groove is made larger than the degree of vacuum suction from the mold cavity. We adopted the casting method of a horizontal clamping vertical casting die casting machine.

[Function] With the above-mentioned structure, during casting, the air entry part below the top surface of the molten metal can be vacuum-sucked immediately before the vacuum suction of the cavity starts, and the air in the joints of the mold and the cast parts can be vacuum-sucked. This prevents air from being drawn in from areas where air can easily enter.

[Example] The details of the present invention will be described below based on the example shown in the drawings.

First, the overall structure of the horizontal clamping vertical casting injection molding apparatus will be explained with reference to FIGS. 2 and 3.

In Figures 2 and 3, the die casting machine 21
The machine includes a horizontal mold clamping unit 22 and a vertical casting unit 23, and the entire horizontal mold clamping unit 22 is fixed on a machine base 24 fixed on a floor surface. The machine base 24 is integrally formed with a pair of left and right support members 24a extending in the length direction of the machine base, and a connecting member 24b (one end is not shown) connecting both ends of the support members 24a. A pair of left and right slide plates 24c, which are elongated slide members each having a flat rectangular cross section, are integrally formed in parallel with each other at the upper ends of the left and right support members 24a. The fixed platen 25 of the horizontal clamping unit 22 is
Approximately square vertical member 25a with sufficient rigidity
and a horizontal member 2 extending in the horizontal direction from its lower end excluding the portions on the left and right slide plates 24c.
5b, and is fixed to the machine base 24 by fixing the lower end of the vertical member 25a to the slide plate 24c with a plurality of bolts. The horizontal member 25b of the fixed platen 25 has a width indicated by the symbol w in FIG. 3 that is slightly smaller than the interval between the slide plates 24c indicated by the symbol _w1 , and is not fixed to the machine base 24. ,
It is configured to bend downward, albeit slightly, when an external force is applied in the vertical direction. A cylinder platen (not shown) is fixed to the other end of the machine base 24 so as to be movable and adjustable, facing a fixed platen 25. The fixed platen 25 and the cylinder platen are connected to each other by a column 27 fixed with a nut 26. The four sections are connected together. A movable plate 28 faces the fixed platen 25 and has a column 27 fitted therein, and is formed to be movable on the slide plate 24c in the direction of distance from and near the fixed platen 25, and between it and a cylinder platen (not shown). are connected by a toggle mechanism 29. 30 is restricted from moving up and down by a key 31 provided horizontally on the fixed plate 25, and is positioned in a direction perpendicular to the plane of the paper by a key 31a provided vertically in the center of the fixed plate 25. It is a fixed mold, and 32
is a movable mold mounted on a movable platen 28 whose movement in the vertical direction is restricted by a key 33, and both molds 30 and 32 are joined to be horizontally openable and closable with a mating surface 34 as a boundary. ing. Here, the vertical key 31a is provided between the fixed platen 25 and the fixed mold 30 on the center line of the machine.
The horizontal core of the fixed mold 30 is connected to the casting sleeve 58 (described later) of the vertical casting unit 23 provided below the mating surface 34 of the fixed mold 30 and the movable mold 32 on the center line of the machine. This is to make it easier to match.

39 is a product extrusion device that extrudes the cast product from inside the cavity 35.

A mating surface 34 between the fixed mold 30 and the movable mold 32
As shown in FIG.
The position is different. That is, in the example shown in FIG. 2, the mating surfaces 34 at the lower end of the mold are close to the fixed platen 25, and the mating surfaces 34 at other parts including the cavity 35 are located far from the fixed platen 25. The mating surface 34 is hooked. At the lower ends of the mating surfaces 34 of the molds 30 and 32, a vertical hole 37 opening downward from the bottom and a half-cylindrical fixing sleeve 38 fitted into the vertical hole 37 are provided. A runner 36 for pouring molten metal, which is also a constriction, extends diagonally upward from the top of the vertical hole 37 along the diagonal mating surface 34.
A vertical gate 36a communicating from the upper end of the obliquely provided runner 36 to the lower part of the cavity 35 is provided. Therefore, the horizontal position of the gate 36a is offset from the vertical central axis of the fixed sleeve 38.

The fixed sleeve 38 has an inner peripheral surface near the top.
A ring-shaped groove 38a is provided. Furthermore, at the upper end of the diagonally provided runner 36, a recessed portion 36b is provided on the side where the runner 36 faces diagonally, in a portion continuing from the vertical gate 36a. These grooves 3
8a and the recess 36b both capture shells, which are solidified molten metal, formed on the inner circumferential surface of the fixed sleeve and the injection sleeve 58, which is a movable sleeve to be described later, to prevent the shells from entering the cavity 35. It was established for this purpose. Fixed sleeve 3
8, the distance from the top of the fixed sleeve 38 to the top surface of the groove 38a should be within 0.15 times the diameter of the inner circumferential surface of the fixed sleeve 38, and the depth of the groove 38a should be It is preferable to set the width ratio in the vertical direction to about 5:1 to 0.5:1 from the viewpoint of capturing the coagulated layer.

On the other hand, the vertical casting unit 23 is equipped with four tie rods 40 whose upper ends are screwed into screw holes provided in the horizontal member 25b of the fixed platen 25 and hang down. It passes between the members 24a and is inserted into a bit 41 provided below the floor surface. 42 is a pair of support members 42
a, and connecting members 42b and 42c at both ends thereof, which are integrally formed in a rectangular frame shape,
Two tie rods 40 are inserted into each support member 42a by threaded portions at their lower ends, and by screwing and tightening a pair of upper and lower nuts 43 and 44 to each tie rod 40, the frame 42 is held in a horizontal state. is strongly supported.

The injection device 45 is supported by the frame 42 so as to be freely tiltable. That is, the injection device 45 includes a clevis-shaped injection cylinder 55 that is slidably supported by the frame 42.
That is, tilting shafts are provided on both sides of the rod-side block 46 of the injection cylinder 55, and by supporting these tilting shafts in the shaft holes of the frame 42, the entire injection device 45 can be tilted to the frame 42. It is rotatably supported. 52 is rod side block 4
6, the main portion thereof is formed into a round bar shape, and a cylinder hole of a sleeve frame 53 is slidably fitted into the docking lamb 52. The sleeve frame 53 has a coupling receiving part 53 at the lower end.
b, and a cylinder portion 53 extending upward from both sides thereof.
c and a sleeve support portion 53d that connects the cylinder portions 53c on both sides at their upper ends, and is configured to rise from the position shown in the figure by introducing pressure oil into the cylinder hole. Third
In the figure, 54a is a stopper fixed to the stationary platen 25 to restrict the upper limit of the sleeve frame 53, and 54b is a stopper fixed to the frame 42 to restrict the lower limit of the sleeve frame 53.

The injection cylinder 55 has a cylinder tube 50
A piston rod is provided which is moved up and down by the introduction of pressure oil into the frame 46, and this piston rod passes through a rod hole in the frame 46. Reference numeral 58 denotes an injection sleeve, also called a movable sleeve, which is formed into a cylindrical shape and is fixedly supported by the sleeve support portion 53d at the upper end of the sleeve frame 53. Inside the injection sleeve 58, a plunger tip, which is the tip of the plunger 59, is moved up and down. The lower end of the plunger 59 is connected to the piston rod 56 of the injection cylinder 55 by a coupling 60.
are connected concentrically. The outer peripheral surface of the lower end of the coupling ring 60 can come into contact with the inside of the upper surface of the coupling receiving part of the sleeve frame 53 or move away from it. Injection sleeve 58
As the sleeve frame 53 rises, the fixed sleeve 38 is fitted into the vertical hole 37 shown in FIG.
The head of the plunger 59 is connected to the lower end of the injection sleeve 58 and the fixing sleeve 38 after the connection. Note that both the fixed sleeve 38 and the movable injection sleeve 58 are collectively referred to as a cast sleeve. 62 is the horizontal member 2 of the fixed plate 25
5b is a centering ring that guides the injection sleeve 58.

Next, a tilting device for tilting the entire injection device 45 for pouring will be described. The rod side block 46 of the injection cylinder 55 and the head cover are vertically connected on one side by a pair of connecting plates 63, and the connecting member 4 of the frame 42
A pair of brackets 64 are fixed to 2b and project diagonally downward. 65 is bracket 64
The piston rod 67 is a tilting cylinder rotatably supported via a bearing 66, and the working end of the piston rod 67 is pivotally connected to the connecting plate 63 by a pin 68, and the piston rod 67 is moved forward and backward by pressure oil. As a result, the entire injection device 45 is configured to stand upright and tilt between the solid line position and the chain line position in FIG. Further, a striker 6 is provided at the shaft end of the tilting shaft that rotates integrally with the injection device 45.
9 is fixed, and a pair of upper and lower limit switches 70, 71 corresponding to the active end of the striker 69 are fixed to the frame 42, so that the rising and tilting operations of the injection device 45 are stopped by contact between these switches. It is configured.

Next, details of the vacuum suction mechanism and vacuum suction system will be explained with reference to FIG. 1 and FIGS. 4 to 11.

In each figure, the same or corresponding parts as in FIGS. 2 and 3 are denoted by the same reference numerals, and the explanation thereof will be omitted.

In FIG. 1 etc., a fixed mold 30 and a movable mold 3
2 is joined and molded at a mating surface 34, and there is a cavity 35 and a constriction 36 inside.
and the injection hole portion (vertical hole portion) 37 and the mating surface 3
A pair of half-shaped fixed sleeves 38, 38 are formed on both sides of the injection hole 37, respectively.
is fitted. The die casting machine of this embodiment is of a horizontal mold clamping type and a vertical casting type, with a movable mold 32
Mold clamping and mold opening are performed by moving the cylinder horizontally, and the injection cylinder 55 moves the molds 30 and 32 in the horizontal direction.
is located directly below. The injection cylinder 55 is equipped with a piston rod 55a that moves forward and backward under hydraulic pressure, and a plunger 59 shown in detail in FIGS. 4 to 7 is concentrically connected to the working end of the piston rod 55a by a coupling 60. An injection sleeve 58 is formed to have the same diameter as the fixed sleeve 38 and is inserted into and removed from the fixed sleeve 38, and a plunger tip 59a at the head of the plunger 59 slides into the inner hole 58a. The injection sleeve 58 is inserted freely into the fixed sleeve 38, and the plunger tip 59a is inserted into the injection sleeve 58, and the plunger tip 59a is tilted together with the injection cylinder 55 by the tilting cylinder 65 to inject the molten metal into the injection sleeve 58. There is. After pouring the molten metal, the injection cylinder 55 is erected, the injection sleeve 58 is pressed against the fixed sleeve 38, and the piston rod 55a is advanced by hydraulic pressure, so that the plunger tip 59a injects the molten metal into the cavity 35.

Here, details of the plunger 59 will be explained. As shown in FIG. 4, the plunger rod 72 connected to the piston rod 55a by the coupling ring 60 is formed in a stepped manner in the order of a screw hole 72a, a pressure reducing tube support hole 72b, an air passage hole 72c, and a bottom hole (not shown) from the top. It is equipped with an inner hole, and the top screw hole 7
2a, a lower threaded portion 73a of a threaded pipe 73 is screwed into the collar until it stops at a stepped portion. A pair of upper and lower adapters 74 and 75 are loosely attached to the central threadless portion 73b of the threaded pipe 73.
The plunger tip 59a screwed into the upper threaded portion 73c of No. 3 and the plunger rod 72 are clamped and fixed. Reference numeral 76 denotes a pressure reducing tube consisting of a holding cylinder (not shown) at the end and a pipe 76a welded to the holding cylinder, which is inserted from the bottom hole 72d side and the holding cylinder is inserted into the upper end of the bottom hole (not shown) at the lower end of the plunger rod. The pipe 76a passes through the air passage 72c and its upper portion is fitted into the pressure reducing pipe support hole 72b. 77 is held at the lower end of the plunger rod 72 and includes a holding cylinder, a pipe 76a, and a threaded pipe 7.
It is a water-cooled pipe that passes through the plunger tip 59a, and its tip faces into the space 59b of the plunger tip 59a.
Reference numeral 78 indicates O-rings as sealing materials provided at various locations.

An annular groove 59c provided on the outer periphery of the plunger tip 59a and an annular groove 74a provided in the adapter 74 communicate with each other through an air passage 59d, and an annular groove 75a provided in the adapter 75 is provided with a filter 79 made of wire mesh. The air passages 75b communicate with each other. An air passage 80 formed between the air passage hole 72c of the plunger rod 72 and the pipe 76a communicates with the annular groove 75a through an air passage 81, which is opened at the lower end of the air passage 80 (not shown). The suction hole has a pneumatic circuit shown in Figure 1 (described later).
A pipe 83 having a flexible portion 82 is connected thereto. On the other hand, the water cooling pipe 77a has a lower end opening connected to a cold water inlet (not shown) at the lower end of the plunger rod 72 via a cold water passage, an annular groove, etc., and an upper end opening connected to the space 59b.
It communicates with a cold water outlet (not shown) at the lower end of the plunger rod 72 via a cold water passage 84 extending downward around the pipe 77a and a water channel. The cold water inlet is connected to a pump or the like through a flexible hose or the like, and the cold water supplied to the cold water inlet by the operation of the pump rises inside the pipe 77a and flows into the space 59b.
After cooling the plunger tip 59a, it flows down the cold water passage 84 and is drained from the cold water outlet.

Next, the mold degassing device will be explained with reference to FIGS. 10 and 11. As shown in FIG. 11, on the outer periphery of the cavity 35 of both molds 30, 32, a gas vent path 85 and a gas vent groove 86 are formed on both sides of the mating surface 34 to communicate the cavities 35. The mold degassing device indicated by the symbol 87 is
Located right above this gas vent groove 86, for example,
It is fixed to the movable mold 32 side. That is, as shown in FIG. 10, a cylinder 89 is attached to the upper end of a bracket 88 fixed to the movable mold 32, and a cylinder 89 is attached to the lower end flange, which is the working end of the piston rod 90, which moves back and forth using the fluid pressure. A cylindrical spool 91 is fixed by engaging its lower end into the circular hole in the upper end face of both the molds 30 and 32 so as to be freely inserted and removed. During mold clamping and mold opening, the cylinder 8
9, the spool 91 is inserted into and removed from the molds 30 and 32 via the piston rod 90. Below the spool 91 inserted into the molds 30 and 32, there is provided a valve chamber 92 and a bypass 93 that detours laterally to communicate between the valve chamber 92 and the gas vent groove 86. A valve seat 94 facing the valve chamber 92 is provided on the lower end surface of the valve chamber 91.
is formed. A pair of elongated pieces 95 provided on the outer peripheral wall of the spool 91 have both rod portions 96 of a return rod 96.
A is slidably engaged with the piston rod 90, and between the return rod 96 and the flange portion of the piston rod 90 there are members such as a tension spring 97, a cylinder, a solenoid device, a gravity device, etc. that urge the return rod 96 upward. is being strung up. Below the return rod 96 is a cylindrical portion 98.
A valve guide 98 is integrally formed with a screw hole portion 98b and a pair of screw hole portions 98b, and is fixed to the spool 91 with the screw hole portion 98b attached inside the elongated hole 95. A valve rod 101 screwed into a screw hole of the return rod 96 is slidably supported. A valve body 101a is provided at the lower end of the valve stem 101 and seats on the valve seat 94 when the valve stem 101 rises. It is configured to sit due to the inertial force of the advancing molten metal and to isolate the inner chamber of the spool 91 from the gas vent groove 86 and the bypass 93.
102 is a ball that engages with the groove 101b of the valve stem 101 by the bias of the compression coil spring 103;
1 is a bolt, and 101 is a nut, which form a locking mechanism. If no external force is applied to the valve body 101a, which is once closed by the pressure of the molten metal,
It is configured so that it will not open again due to the action of members such as a tension spring 97. Note that the valve body 101a is
It opens by pushing down the rod portion 96a of the return rod 96. 104 is the operating spool 9 of the cylinder 89
The bracket 88 is a stopper that restricts the upper limit of the rise of the rod portion 96a of the return rod 96 that rises with the movement of the bracket 88.
is fixed. An exhaust hole 105 is opened at the lower end of the spool 91, and the exhaust hole 105 is connected to a pipe 106 of a pneumatic circuit (described later) shown in FIG.

As shown in FIG. 4, the injection sleeve 58 into which the plunger tip 59a of the plunger 59 as described above is slidably inserted can be inserted into and removed from the injection holes 37 of the molds 30 and 32 as described above. The upper ends thereof are formed in a tapered shape, and the upper fitting surfaces 58b are pressed against and abutted against the injection sleeve abutment surface 38a on the lower end surface of the fixed sleeve 38. There is. In addition, between the two surfaces 58b and 38a, a gasket 38b as a sealing material formed in a half ring shape using a heat-resistant material such as copper or asbestos is attached to the fixing sleeve 3.
It can also be fixed on the 8th side. Furthermore, annular grooves 30a and 32a are provided between the injection sleeve 58 inserted into the injection hole 37 and the injection hole 37.
An air passage 30b is communicated with the annular groove 30a on the fixed mold 30 side and opened to the outside of the mold, and the piping shown in FIG. 107 is connected. In addition, as shown in FIGS. 8 and 9, a fixed sleeve 38 in the form of a half is fitted into the injection hole 37 of the movable mold 32 and the fixed mold 30 on a perpendicular dividing surface and is integrally attached thereto. And on both outsides of the injection sleeve insertion hole below this fixed sleeve 38, a fixed sleeve 38 is provided.
A vertical groove 32b is provided at a distance from the dividing surface of the injection sleeve insertion hole and parallel to the fixed sleeve 38 and the injection sleeve insertion hole, and slightly away from the lower surfaces of the fixed mold 30 and the movable mold 32. The lower end of the vertical groove 32b located above is communicated with the annular groove 32a.

Next, a pneumatic circuit including the plunger 59, the annular groove 32a, and the gas venting device 87 will be explained based on FIG. A pipe 109 connected to the vacuum pump 108 is branched into a pipe 110 and a pipe 111 in the middle, and a vacuum tank 112 and an auxiliary vacuum tank 113 are provided on the pipes 109 and 110, respectively. Piping 109, 110
is the pipe 1 via filters 114 and 115.
06 and 83, respectively. and,
Solenoid valves 116, 11 are installed on the pipes 110, 111.
7 are arranged respectively, and when the solenoid of the solenoid valve 116 is energized from the state shown in the figure, the air in the plunger 59 is sucked, and when the solenoid of the solenoid valve 117 is energized, the air is sucked into the cavity 35 through the gas venting device 87. air is sucked. In this case, the suction on the gas venting device 87 side is controlled by the plunger 5 according to a command from a timing regulation device (not shown).
It is set to be delayed, for example, by about 0.1 seconds to 1 second, preferably about 0.3 to 0.5 seconds, compared to the suction on the 9 side. In addition, the degree of vacuum is, for example, 200 to 300 Torr on the lower side of the plunger 59, etc., and 150 to 30 Torr on the side of the gas venting device 87.
It is set to about 250 Torr, and this is achieved by providing an auxiliary vacuum tank 113. The auxiliary vacuum tank 113 is provided near the plunger 59, which is constructed in consideration of the resistance generated in relatively thin piping sections and passages during vacuum suction. Further, the pipe 83 having the flexible hose 82 is made as short as possible and has a relatively large pipe diameter, for example, 1 inch.

Furthermore, the air passage 3 provided in the fixed mold 30
0b includes a filter 118 and a flexible portion 11.
9 and a pipe 107 equipped with a solenoid valve 120 are connected to the pipe 107, which is connected to the pipe 83 leading from the auxiliary vacuum tank 113 to the plunger 59.
It is connected before the solenoid valve 116.

Further, piping 124, 125, 126 equipped with solenoid valves 121, 122, 123 are connected to the other ports of the solenoid valves 116, 117, 120, respectively.
6 is connected to a pipe 128 equipped with a variable throttle valve 127 and a pressure regulating valve, and is connected to, for example, an air compressor 1 in a factory.
It is connected to 29. And the solenoid valve 116,
117, 120 are closed and the solenoid valves 121, 122,
By opening 123, high pressure air flows into the plunger 5.
9 and injection sleeve 58 parts, gas venting device 87
It is sent to the factory and used as a spray for internal cleaning.

A casting method using the die casting machine configured as described above will be explained. The movable mold 32 is moved to the position shown in FIG. 2 and the mold is clamped, and the cylinder 89 of the degassing device 87 is operated to move the spool 91 to the spool of the molds 30 and 32 as shown in FIG. Insert into the hole. At this time, since the piston rod 55a of the injection cylinder 55 and the injection sleeve 58 are not lowered, the injection cylinder 55 is tilted and the plunger 59 is moved into the lowered injection sleeve 58, as shown by the chain line in FIG. After injecting the molten metal and standing up again as shown in solid lines in FIG. 2, the injection sleeve 58 is raised and engaged with the fixed sleeve 38 as shown in FIGS. 1, 4, and 8. After evacuating, which will be described later, oil is supplied to the injection cylinder 55 and the piston rod 55a is raised, the plunger 59 is raised and the injection of molten metal indicated by reference numeral 127 in FIG. 4 is started. At this time, the plunger 59 has a cold water inlet 8.
Cold water is supplied from pipe 77.
After rising in the space 59a, the water overflows into the space 59b and flows down into the cold water passage 84, thereby cooling the plunger tip 59a and the plunger rod 72. Further, the injection sleeve 58 is also cooled from the outside by a cooling device (not shown). Therefore, on the upper end surface of the plunger tip 59a and on the inner wall surface of the injection sleeve 58 following this, a solidified layer is formed by the solidification of the molten metal, as indicated by reference numeral 9 in FIG. 4 and FIG. 12. And vacuum tank 11
2 and the auxiliary tank 113 are already depressurized by suction with the vacuum pump 108, so when the solenoid valve 116 is first opened before or during injection, negative pressure acts on the suction hole of the plunger rod 72. , plunger tip 59a
The air in the annular groove 59c flows through the air passage 59d, the annular groove 74a, the filter 79, the air passage 75b, the annular groove 75a, the air passage 81, and the air passage 80.
It is sucked in through the path of Furthermore, when the solenoid valve 120 is opened at the same time as the solenoid valve 116 is opened, the annular groove 30a,
Air passage 30 communicating with 32a and vertical groove 32b
A negative pressure acts on b, and the air in the annular grooves 30a, 32a and the vertical groove 32b is sucked through the air passage 30b. Further, when the solenoid valve 117 is opened about 0.1 seconds to 1 second later, preferably 0.3 seconds to 0.5 seconds later, the gas in the cavity 35 is released from the gas vent path 8.
5. The gas inside the cavity 35 is sucked through the exhaust hole 105 through the gas vent groove 86 and the bypass 93, and is discharged. By suctioning from both the plunger 59 side and the gas venting device 87 side in this way, the inside of the cavity 35 and the gap between the injection sleeve 58 and the plunger tip 59a become vacuum, but the plunger By suctioning the plunger 59 side slightly faster and by making the degree of vacuum on the plunger 59 side larger than the degree of vacuum on the degassing device 87 side, the solidified layer 9 is brought into contact with the end surface of the plunger tip 59a, as shown in FIG. The solidified layer 9 is strengthened by being in close contact with the surrounding annular recess, and is also cooled to 300 to 400° C. as the plunger tip 59a is cooled, thereby increasing the thickness of the solidified layer 9. This prevents outside air from entering through the gap between the injection sleeve 58 and the plunger tip 59a. Moreover, the molten metal does not get inserted into the cavity 35 before the molten metal is injected.

After creating a vacuum inside the cavity 35 in this way, the injection operation is started, and when the plunger tip 59a is advanced while degassing, the molten metal 127 in the casting sleeve 58 is transferred to the fixed sleeve 3.
8 and the constricted portion 36 into the cavity 35. As the plunger tip 59a moves forward, the solidified layer 9 is pushed upward by the plunger tip 59a, and the upper end of the solidified layer 9 comes into contact with the flat surfaces 30c and 32c in front of the constriction 36, but the annular groove 30a,
Air is sucked from 32a, and there is a tapered part and a gasket 3 at the joint of both sleeves 38, 58.
8b prevents outside air from entering, and the cylindrical portion of the solidified layer 9 rises together with the plunger tip 59a while remaining in close contact with the inner peripheral surface of the casting sleeve 58, and its tip becomes constricted. It comes into contact with the flat surfaces 30c and 32c in front of the portion 36. Then, as the plunger tip 59a further rises, the solidified layer 9 is formed between the end face of the plunger tip 59a and the flat surfaces 30c and 3 of the molds 30 and 32.
2c, which causes the solidified layer 9 to break. However, even if the inside of the cavity 35 is vacuumed from above, air will not enter from the injection sleeve as described above, so air will not enter the molten metal. There is no disturbance in the flow of the molten metal. When the cavity 35 is filled with molten metal 127, this molten metal 12
7 rises in the gas vent groove 86 and comes into contact with the lower surface of the valve body 101a together with the gas. At this time, valve body 1
The impact applied to the valve element 101a is larger than the impact applied to the valve element 101a because the mass of the molten metal 127 is extremely large compared to the mass of the gas and has a large inertia.
The valve body 101a closes the valve seat 94 by rising while compressing the valve body 101a. Therefore, the molten metal 93 is the valve seat 9.
Even if the outflow from the molten metal 93 is blocked and the gas mixes with the gas in the gas vent path 85 and the gas vent groove 86 and hits the valve element 101a discontinuously in the form of droplets, the valve is immediately pushed up by the molten metal 93. Since the body 101a is pulled upward by the tension spring 97, the exhaust passage is reliably closed by the valve body 101a maintained in the upward position.

After cooling under pressure for a predetermined time with the valve body 101a closed, the movable mold 32 is opened and the gas venting device 87 is opened.
The spool 91 is raised by the cylinder 89 to release the engagement with the movable mold 32, and the product is taken out from the cavity 35.

Note that when the spool 91 is raised, the valve body 10
Due to the separation resistance between 1a and the solidified metal, the spool 91
As a result, the ball 102 that had been disengaged from the groove 101b of the valve stem 101 engages with the groove 101b again, completing preparations for the next casting. Furthermore, at the upper limit of the spool 91, the return rod 96 contacts the stopper 104 and pushes down the valve rod 101, so that the valve body 101a is reliably opened and ready for the next casting.

In addition, in the embodiment, the vertical groove 32b and the annular groove 3
0a and 32a, and vacuum suction is carried out simultaneously from these. However, it is also possible to separate the vertical groove 32b from the annular grooves 30a and 32a without communicating with them, and apply vacuum suction from both separately. can. In that case, the vacuum suction from the annular grooves 30a and 32a is performed at the same time as the vacuum suction from the plunger tip 59a, and the vacuum suction from the vertical groove 32b is performed immediately after the molten metal begins to pass through the constriction 36. It's good to do this. However, at this time, vacuum suction is performed from the cavity 35 after the vacuum suction is performed from the vertical groove 32b.

By the way, normal aluminum products are 40~
Although it contains gas of 60 c.c./100 g Al, if the degassing device 87 is used, the gas becomes 5 to 10 c.c./100 g Al, and a high quality product with pressure resistance of 100 to 150 Kg/cm ² is obtained. Generally, heat treatment is possible when the gas content is less than 5 c.c./100 g Al, and welding is possible when the gas content is 1 c.c./100 g Al. This results in an injection product that can be heat treated and welded. In addition, this can be achieved not only by using new materials but also by using return materials.

[Effects of the Invention] As is clear from the above description, according to the present invention, not only the outer peripheral surface of the plunger tip located below the upper surface of the molten metal in the mold cavity but also the side of the fixed sleeve and the injection sleeve insertion hole can be Vertical grooves and annular grooves are provided on the dividing surface of the mold, vacuum suction ports are provided in these air inlet parts, and vacuum suction is performed at least 0.1 seconds before the inside of the mold cavity is vacuum-suctioned. Since the molten metal is poured using vacuum suction from the mold, air is not sucked into the cavity, and the solidified layer does not enter the cavity, causing cavities and pinholes in the product. The quality of the product can be significantly improved.

[Brief explanation of the drawing]

Figures 1 to 11 show one embodiment of the apparatus for carrying out the method of the present invention, in which Figure 1 is a circuit diagram of a vacuum suction system, Figure 2 is a longitudinal sectional view, and Figure 3 is a diagram of a vacuum suction system. Fig. 1 is a view taken in the direction of arrow A, Fig. 4 is an enlarged sectional view of the casting sleeve and plunger, Fig. 5 is a sectional view taken along the - line in Fig. 4, and Fig. 6 is a sectional view taken along the - line in Fig. 4. , FIG. 7 is a sectional view taken along the - line in FIG. 4, FIG. 8 is a sectional view taken along the - line in FIG. 4, and FIG. 9 is a sectional view taken along the - line in FIG.
A line sectional view, FIG. 10 is a sectional view of the degassing device,
FIG. 11 is a sectional view taken along the line XI-XI in FIG. 10, and FIG. 12 is a longitudinal sectional view of a conventional casting sleeve portion. 30... Fixed mold, 32... Movable mold, 30a, 3
2a... Annular groove, 32b... Vertical groove, 35... Mold cavity, 38... Fixed sleeve, 55... Injection cylinder, 59... Injection sleeve, 59a... Plunger tip, 87... Gas venting device, 108... Pump, 1
12... Vacuum tank, 127... Molten metal.

Claims (1)

[Claims] 1 Connect the mold cavity to a vacuum source via a gas venting device, connect the outer peripheral surface of the plunger tip to the vacuum source, and connect the half-shaped fixing device provided on the vertical separation surface between the movable mold and the fixed mold. A longitudinal groove parallel to the fixed sleeve and the injection sleeve insertion hole is formed on the separation surfaces of the sleeve and the injection sleeve insertion hole on both outer sides of the sleeve and the injection sleeve insertion hole below the fixed sleeve, at a distance from the separation surfaces of the fixed sleeve and the injection sleeve insertion hole. An annular groove is provided on the inner peripheral surface of the injection sleeve insertion hole, and a horizontal clamping vertical casting die casting machine is used, in which an annular groove is provided on the inner circumferential surface of the injection sleeve insertion hole, and the annular groove is connected to a vacuum source. At least 0.1 seconds before the start of suction, vacuum suction is applied from the outer peripheral surface of the plunger tip and the longitudinal groove and the annular groove, and then the molten metal is poured while applying vacuum suction from the mold cavity. and, during the vacuum suction, the degree of vacuum suction from the outer peripheral surface of the plunger tip and the vertical groove and the annular groove is greater than the degree of vacuum suction from the mold cavity. Casting method for embedded die casting machine.