JP6900957B2 - Injection equipment and casting method for casting equipment - Google Patents

Description

The present invention relates to an injection device for a casting device suitable for manufacturing a die-cast product and a casting method using the injection device.

When producing a casting made of a light metal alloy, a die casting method, which is a method of pressure-filling a molten material (molten metal) in a mold, is often used. In the die casting method, the molten metal in the injection sleeve (hereinafter, the injection sleeve is referred to as "sleeve") is filled in the mold at high speed, so that the productivity is good and a large thin product can be made. In addition, it has the advantages of high dimensional accuracy, a fine casting structure, and a clean casting surface. On the other hand, since the molten metal is filled at high speed, there is a disadvantage that air is easily entrained and a blow hole (hole-shaped defect generated in the casting) is easily formed.

In recent years, in the die casting method, it is necessary to cast a large thin-walled product, and so-called high-speed injection, in which the injection speed in a high-speed region is increased, is often performed. However, when high-speed injection is performed, air in the sleeve or in the mold cavity (hereinafter, the mold cavity is referred to as "cavity") and gas generated from the mold release agent or the like are entrained in the molten metal. , Will cause casting defects in the product. Therefore, it has become necessary to evacuate the air and generated gas from the sleeve and cavity to create a vacuum. Patent Document 1 discloses a vacuum die casting method in which air or generated gas in a sleeve or cavity is evacuated to create a vacuum in the die casting method.
In such a conventional technique, a vacuum tank is installed around the die casting machine, and the air in the sleeve and the cavity is exhausted by using a vacuum valve or the like. The vacuum valve is a kind of shut-off valve, and adopts a configuration in which the molten metal collides with the bottom of the valve to close the valve so that the molten metal does not jump out of the mold.

In the above-mentioned prior art, in the following cases (1) to (3), the suction port communicating with the vacuum tank in the sleeve (hereinafter referred to as “sleeve side suction port”) is connected to the molten metal residue (particles of aluminum melt). ) May be easily clogged.
(1) When the amount of hot water supplied is large (that is, the sleeve filling rate is high).
(2) When the wave of the molten metal in the sleeve is large (the wave generated when the molten metal is supplied into the sleeve, the wave generated by the ejection plunger popping out at the start of injection, the wave generated when the injection speed setting in the low speed region is large) ..
(3) When the position of the suction port on the sleeve side is inappropriate for filling the molten metal.
Further, in the prior art of Patent Document 1, there is only one suction port on the sleeve side, and if the molten metal residue is clogged, the pressure cannot be sufficiently reduced and defects increase. Since there is only one suction port on the sleeve side, it is necessary to manufacture a sleeve in which the suction port on the sleeve side is arranged at an optimum position according to the amount of hot water supplied, which lacks versatility. Therefore, it is necessary to have various types of sleeves, which are consumables, depending on the mold and the product, and the sleeve manufacturing cost increases. Further, when the mold is replaced, it is necessary to replace the sleeve with a sleeve corresponding to the mold, which increases the cost due to the increase in the setup time.

Further, in the prior art of Patent Document 1, even if the molten metal is clogged with debris and the suction area is reduced or blocked, it cannot be detected as an abnormality. Casting continues without sufficient decompression, resulting in continuous production of defective products. Further, the residue of the molten metal may enter the vacuum line, causing a malfunction of the solenoid valve that turns the vacuum on and off.

JP-A-57-072766

The present invention has been made in view of such problems of the prior art, and in the die casting method, the inside of the sleeve and the mold cavity can be efficiently put into a high vacuum state to reduce product defects and perform stable production. The challenge is to realize.

In a casting device including an injection device and a vacuum device, the injection device consists of a sleeve having a suction port connected to the vacuum device and an injection plunger, and the vacuum device is a selection valve that allows the use or non-use of vacuum suction to be selected. The sleeve was composed of a pressure tank for an air blow for cleaning the suction path and a vacuum tank for drawing the inside of the sleeve into a vacuum, and the sleeve was composed of a plurality of suction ports.

It was decided to provide a vacuum filter between the suction port of the sleeve and the selection valve.

The pressure of the suction path at the time of air blow is monitored by a pressure gauge, and when the pressure of the air at the time of air blow rises and reaches the set value, an alarm is issued.

At the time of vacuum suction, the degree of vacuum in the suction path of the sleeve is monitored with a pressure gauge.

In the casting method using the casting device, the injection plunger starts advancing to close the pouring port and then the sleeve is evacuated by the vacuum tank, and the selection valve is closed according to the advancing position of the injection plunger. And the step of performing an air blow to remove the debris of the molten metal caught in the suction path at the forward limit of the injection plunger.

In the air blow step, the debris of the molten metal in the suction path is discharged into the sleeve, and the debris of the molten metal in the sleeve is scraped out by the injection plunger when the injection is retracted.

A pressure gauge is used to monitor the clogging of the vacuum filter by the pressure in the suction path.

The following effects were produced by providing a plurality of suction ports on the sleeve side on the sleeve and installing a suction port selection valve at each suction port so that the use or non-use of the suction port can be selected.
(1) Defect reduction, stable production Since there are multiple suction ports on the sleeve side, the suction area has increased and it has become possible to efficiently create a high vacuum state.
(2) Countermeasures against clogging of molten metal debris The suction port, which is easily clogged with molten metal debris, can be eliminated by using the suction port selection valve.
(3) Stable production Since there are multiple suction ports on the sleeve side, vacuuming can be performed by suction ports other than the unnecessary suction ports, and non-defective products can be produced stably.
(4) Expansion of versatility and cost reduction It is not necessary to prepare a sleeve according to the mold and product, which leads to cost reduction. The number of sleeve types is reduced, making it easier to manage. Sleeve replacement time can be reduced.
(5) Defect reduction Since the area of the suction port on the sleeve side can be made larger than the suction area on the mold side, the effect of preventing preceding molten metal due to evacuation can be expected. By starting the sleeve vacuum first, it is possible to prevent the hot water more effectively. As a result, defects such as chipping (chips in the product part, chipping), peeling (phenomenon that the surface of the product is peeled off, peeling), and mekure (the surface of the product is turned over, stripping for shot blast) can be reduced. It is possible.

(6) Adjustable vacuuming time of each suction port By providing a suction port selection valve, the vacuuming time of each suction port can be adjusted by the position, time, filling rate, and the like.
(7) Stable production by suppressing the pressure rise of the vacuum tank The injection plunger can be closed immediately after passing through the suction port on the sleeve side (even while passing), so that the pressure rise of the vacuum tank can be suppressed and it is located far from the pouring port. Does not reduce the vacuum suction capacity of the suction port on the sleeve side.
(8) Since the injection plunger 12 can be set to evacuate through the suction ports 14 to 17 on each sleeve side until just before the completion of passage, the injection plunger 12 can be evacuated through the gap between the injection plunger 12 and the sleeve 11. , It is possible to prevent outside air from entering the sleeve 11 in the negative pressure state.

It is a schematic side view (partial cross section is shown) of the die casting machine provided with the injection device of one Embodiment of this invention. It is the schematic of the injection device and the vacuum device of this invention. (A) to (d) are explanatory views explaining the injection filling process from the hot water supply process of one embodiment. It is a flowchart of a die casting casting method. It is a flow chart of a casting method using the vacuum apparatus of this invention. It is explanatory drawing of the injection apparatus of another embodiment of this invention. It is explanatory drawing of the injection apparatus of another embodiment of this invention.

FIG. 1 is a schematic side view (partially shown in cross section) of a die casting machine provided with the injection device 1 according to the embodiment of the present invention.
In the die casting machine of the present embodiment, the movable platen 4 is provided with the movable mold 22, and the fixed platen 5 is provided with the fixed mold 21. The movable platen 4 moves on the machine base 8 toward the fixed platen 5 by a mold opening / closing / mold tightening mechanism (not shown) such as a toggle link mechanism or a ball screw mechanism. As a result, the movable mold 22 and the fixed mold 21 are die clamped to form the cavity 23. Four tie bars 7 are inserted into the movable platen 4 and the fixed platen 5 through insertion holes, and the movable platen 4 moves freely with respect to the fixed platen 5 along the tie bar 7. By engaging the fixed mold 21 and the movable mold 22 as shown in FIG. 1, a cavity (product part) 23 is formed between them, and a molten metal 18 such as aluminum or an alloy thereof is injected and filled in the cavity 23. The cast and molded product is manufactured.

The fixed platen 5 includes a sleeve (injection sleeve) 11. A hydraulic cylinder (not shown) is provided for driving at the right end of the plunger rod 19 of the injection plunger 12 in order to inject the molten metal 18, and the plunger rod 19 has a coupling (not shown). It is connected to the cylinder rod of the same hydraulic cylinder via. Further, the fixed mold 21 is provided with a sleeve 11 for storing the molten metal 18, and the sleeve 11 is fitted with a hole 10 provided in the fixed mold 21 to form a hot water storage chamber. The hot water storage chamber communicates with the cavity 23 via the runner 24 and the gate 25. The molten metal 18 is poured from the pouring port 13 with the radle 43 (FIG. 3A) of the water heater, and then the molten metal 18 is pushed into the cavity 23 with the injection plunger 12. As an example, the position of the injection plunger 12 is detected by a non-contact sensor at a mark provided on the cylinder rod along the stroke of the hydraulic cylinder. In addition, it may be detected by a switch lever provided on the plunger rod 19 and a plurality of fixed limit switches.

FIG. 2 is a schematic view of the injection device 1 and the vacuum device 2 of the present invention, and shows the configuration of a sleeve 11 of a die casting machine having a plurality of suction ports 14 to 17 of the present invention. The suction ports 14 to 17 are installed in the order of moving away from the position closer to the pouring port 13 toward the mold side.
The inside of the sleeve 11 of the die casting machine communicates with the cavity 23 composed of the fixed mold 21 and the movable mold 22, and the inside of the sleeve 11 is formed from the pouring port 13 by the radle 43 of the water heater shown in FIG. 3 (a). The molten metal 18 poured into the mold is injected into the mold (cavity 23). An injection plunger 12 is arranged in the sleeve 11, and by advancing the injection plunger 12, the injection plunger 12 pushes the molten metal 18 into the cavity 23 from the sleeve 11. The sleeve 11 of the present embodiment has a plurality of holes above the sleeve 11. These holes are referred to as suction ports 14 to 17, and air in the sleeve 11 and the cavity 23 is evacuated from the suction ports 14 to 17, and the inside of the sleeve 11 and the cavity 23 are evacuated. The air in the cavity 23 may be sucked from the mold side at a suitable timing by another vacuum line provided separately from the line of the vacuum tank 36. In the case of FIGS. 1 and 2, the number of suction ports 14 to 17 is 4, but this is an example and may be any number as long as there are a plurality (at least 2). Further, the opening positions of the suction ports 14 to 17 do not necessarily have to be the same pitch or regular arrangement, but may be different pitches or irregular arrangements in consideration of the molten metal behavior in the sleeve 11. Similarly. The shapes and opening areas of the suction ports 14 to 17 do not necessarily have the same specifications, but may have different shapes and opening areas in consideration of the molten metal behavior in the sleeve 11.

3A to 3D are explanatory views for explaining the injection filling step from the hot water supply step of the present embodiment. In FIG. 3A, the molten metal 18 is poured from the pouring port 13 installed in the sleeve 11 with the radle 43 of the water heater (hot water supply step). As seen in FIG. 3 (b), the injection cylinder is operated, and the injection plunger 12 at the tip of the plunger rod 19 extrudes the molten metal 18 in the hot water storage chamber from the runner 24 and the gate 25, and FIG. 3 (c). ), The molten metal 18 is filled in the cavity 23 (injection filling step). Specifically, the advancing speed of the injection plunger 12 is set low (low speed region) until the extruded molten metal 18 reaches the gate 25 via the runner 24, and after the molten metal 18 reaches the gate 25. The forward speed of the injection plunger 12 is set high (high speed region) until the cavity 23 is filled with the molten metal 18. At the timing when the cavity 23 is filled with the molten metal 18 (speed / pressure switching point / VP switching point), the forward operation control of the injection plunger 12 is switched from the speed control to the pressure control (pressure holding control / pressure increasing control). After that, the molten metal 18 is cooled in the mold in a state where the holding pressure (increasing pressure) is applied by the injection plunger 12, and when it is sufficiently solidified, the movable platen 4 is moved to the original position on the left side of FIGS. Return to and the mold opens. When the mold is opened, a plurality of extrusion pins 42 attached to the extrusion plate 41 are advanced to the right side of FIG. 1 by a hydraulic mechanism (not shown), and the product is taken out.

Next, as an example, an embodiment in the case where the number of suction ports 14 to 17 is four will be described below with reference to FIG. In FIG. 2, the suction ports 14 to 17 are referred to as the first suction port to the fourth suction port, respectively. The suction ports 14 to 17 are connected to the vacuum tank 36 by a pipe (also referred to as a suction path). From each of the suction ports 14 to 17, first, the pressure gauge 32, the suction port selection valve 33, and the distribution valve 34 are configured as independent suction paths 51 via the vacuum filter 31, and from the distribution valve 34, the pressure gauge 32, the suction port selection valve 33, and the distribution valve 34 are configured as independent suction paths 51. It is connected to the vacuum tank 36 via the vacuum / air blow switching valve 35 and the pipe 55. In FIG. 2, the vacuum tank 36 is above the sleeve 11, but the present invention is not limited to this, and the vacuum device 2 may be below or to the side of the sleeve 11. On the other hand, the vacuum / air blow switching valve 35 is connected to the pressurizing tank 38 via another pipe 56. An air source 39 is connected to the pressurizing tank 38.

In the present embodiment, the suction port selection valve 33 that enables the use or non-use of vacuum suction by the vacuum device at each suction port 14 to 17 is provided between the distribution valve 34 and the vacuum filter 31. The vacuum filter 31 is provided because when the inside of the sleeve 11 is evacuated, the residue of the molten metal may be drawn together with the air. Without the vacuum filter 31, the debris of the molten metal enters the piping and each valve and causes clogging, which hinders stable production. Therefore, the vacuum filter 31 catches the molten metal residue and prevents the molten metal residue from being brought into the pipe or valve. The material of the vacuum filter 31 is preferably a material having a small exhaust resistance during vacuum suction and a material that does not burn even if high-temperature debris from the molten metal enters. Inexpensive and replaceable materials such as punching metal, mesh wire mesh, stainless steel scrubbing brushes and the like are desirable.

In the present embodiment, the pressure gauge 32 is installed between the vacuum filter 31 and the selection valve 33 in each suction path 51 of the suction ports 14 to 17. At the time of vacuum suction, the degree of vacuum of each suction path corresponding to each suction port is monitored by the pressure gauge 32. Since the degree of vacuum of each suction path 51 is monitored by the pressure gauge 32, the suction port where the molten metal residue is easily clogged can be eliminated by the suction port selection valve 33. That is, the degree of vacuum of each suction path 51 can be monitored by the pressure gauge 32, the vacuum suction time of the sleeve-side suction port where the molten metal residue is easily clogged can be shortened, and the molten metal residue clogging can be suppressed. The pressure gauge 32 (pressure detection unit) may be a pressure gauge that can measure both the abnormal negative pressure at the time of evacuation and the abnormal pressure (plus) at the time of air blow, but both can be measured and the measured pressure can be measured by an electric signal. A pressure sensor or the like capable of transmitting is more preferable. The pressure detection unit includes a pressure gauge, a compound gauge, a pressure sensor, and the like.
When the suction ports 14 to 17 are air blown from the pressurized tank 38, if the inside of the pipe or the vacuum filter 31 is clogged with the molten metal residue, an abnormal pressure is exhibited. Can detect clogging. At this time, when the pressure rises during the air blow and reaches the set value, the vacuum filter 31, the piping, and the like are clogged, so an alarm is issued. When a clogging alarm is issued, the work will be stopped and the molten metal residue will be cleaned. The suction port, which is easily clogged with molten metal residue, can be eliminated by the suction port selection valve 33. Alternatively, by closing the suction port selection valve 33 early, the vacuum suction time can be shortened and clogging of the molten metal with debris can be suppressed.
At the time of vacuum suction, it can be confirmed that the vacuum drawing operation is normally performed by monitoring the degree of vacuum of the designated suction path with the pressure gauge 32. That is, it indicates that the vacuum / air blow switching valve 35 has operated normally.
By confirming whether or not the vacuuming operation was normally performed without clogging of the molten metal in each suction path, it can be determined that the inside of the cavity communicating with the sleeve was also normally evacuated.

Next, a suction port selection valve 33 that enables selection of use or non-use of vacuum suction by a vacuum device at each suction port 14 to 17 will be described. In the case of FIGS. 1 and 2 of the present embodiment, since there are four suction ports, one suction port selection valve 33 is attached to each of the suction ports 14 to 17. The "use setting" suction port selection valve 33 is opened when the inside of the sleeve 11 is evacuated or when air blow is applied to the suction ports 14 to 17. It closes when there is no need to evacuate or when there is no need to air blow. The suction port selection valve 33 "not used" is normally closed. It may be opened at the time of air blow. The combination of the use and non-use settings of the four suction port selection valves 33 can be freely selected as appropriate.

The vacuum / air blow switching valve 35 is used when (1) the inside of the sleeve 11 and the cavity 23 are evacuated or (2) the inside of the pipe is cleaned by the air blow, that is, in the case of (1) above. When selecting whether to connect the suction port 14 to 17 and the pressure tank 38 (or the air source 39) in the case of (2) above, when selecting whether to connect 14 to 17 and the vacuum tank 36, the vacuum piping 55 It is a switching valve for switching between the air blow pipe 56 and the air blow pipe 56.

In the vacuum tank 36, the air in the vacuum tank 36 is constantly sucked by the vacuum pump 37. Further, the vacuum pump 37 is driven by a motor. The degree of vacuum of the vacuum tank 36 is monitored by the pressure gauge 40, and an alarm is issued when the value becomes worse than the set value. The degree of vacuum of the vacuum tank 36 needs to be maintained at about −95 kPa or less.

The air of the air blow is temporarily stored in the pressure tank 38 from the air source 39, and after the vacuum / air blow switching valve 35 is switched to the air blow, it passes through the vacuum / air blow switching valve 35 and reaches the suction ports 14 to 17. It will be. By switching the vacuum / air blow switching valve 35, for example, when an air blow is formed, air is discharged from the pressure tank 38 to the suction ports 14 to 17, and the air blow of the suction path 51 is performed.

As shown in FIG. 1, a chill vent 27 or a vacuum valve (not shown) is installed at the portion where the fixed mold 21 and the movable mold 22 meet at the upper part of the mold, and these portions (chill vent 27) are installed. In the case of, the air in the cavity is drawn from the connecting port 28). The structure is such that air in the cavity 23 and the sleeve 11 is drawn from both the chill vent 27 (or the vacuum valve) and the sleeve 11 at the same time or at different timings. The chill vent 27 is a chiller that is often used when a light metal molded product is manufactured by a high-pressure die casting method and is used for degassing. When the gas in the cavity 23 is released, the outflow of the molten metal 18 is prevented by the chill vent 27. The chill vent 27 is formed into a pair of blocks, each of which is fixed to the movable mold 22 and the fixed mold 21, and is separated when the mold is opened.

FIG. 4 shows a flowchart of a normal die casting casting method. The flow chart starts from the start of die casting, and the process proceeds in the order of mold clamping, pouring, injection start, and sleeve vacuum. If there is no sleeve vacuum process (sleeve vacuum is not required), the process proceeds in the order of pressure increase switching command, cooling (solidification), mold opening, product removal, product detection, mold spray, injection retreat, and chip lubrication. The next cycle begins. In this step, when the sleeve vacuum is used, the process proceeds to circuit A of the casting method according to the embodiment of the present invention.

Hereinafter, the circuit A of the casting method of the present invention will be described with reference to FIGS. 5 and 2.
In step 101 (S101, the same applies hereinafter), it is confirmed whether the vacuum tank 36 is sufficiently evacuated, and a signal of completion is output.
In step 102, after pouring, the injection plunger 12 advances and reaches a position where the pouring port 13 is closed, and then the vacuum of the sleeve 11 is started. This is called the vacuum start position (FIG. 2) of the injection plunger 12. The arrival detection of the injection plunger 12 at the set vacuum start position detects the stroke of the hydraulic cylinder that drives the injection plunger 12 with a non-contact sensor or the like. The arrival of each set position of the injection plunger 12 in the following steps is also detected in the same manner.
In step 102, after pouring, when the injection plunger 12 advances and reaches the position where the pouring port 13 is closed, the vacuum of the sleeve 11 is started.
In step 103, the vacuum / air blow switching valve 35 is switched toward vacuum.
In step 104, the injection plunger 12 reaches the set position (FIG. 2 / first suction port closing position) for closing the first suction port 14.
In step 105, the suction port selection valve 33 is closed in order to close the first suction port 14.
In step 106, the injection plunger 12 reaches the set position (FIG. 2 / second suction port closing position) for closing the second suction port 15.
In step 107, the suction port selection valve 33 is closed in order to close the second suction port 15.
In step 108, the injection plunger 12 reaches the set position (FIG. 2 / third suction port closing position) for closing the third suction port 16.
In step 109, the suction port selection valve 33 is closed in order to close the third suction port 16.
In step 110, the injection plunger 12 reaches the set position (FIG. 2 / fourth suction port closing position) for closing the fourth suction port 17. Here, the degree of vacuum of the fourth suction port 17 is measured by the pressure gauge 32 at a stage immediately before the injection plunger 12 reaches the set position for closing the fourth suction port 17. The degree of vacuum of the fourth suction port 17 is controlled by setting an upper limit range and a lower limit range. If the degree of vacuum is outside the set range, an alarm is issued with a lamp or buzzer. The upper and lower limits are preferably −90 to −100 kPa.
In step 111, the suction port selection valve 33 is closed in order to close the fourth suction port 17.
In step 112, the vacuum / air blow switching valve 35 is turned off.
In step 113, all the selection valves of the suction ports 14 to 17 are opened.
In step 114, the vacuum / air blow switching valve 35 is set to an air blow.
In step 115, air blow is performed. At this time, the selection valves of the suction ports 14 to 17 may be all opened, or the selection valves may be opened one by one in order.
In step 116, the pressure of each suction path 51 of the suction ports 14 to 17 is measured by the pressure gauge 32 to determine the clogging in the pipe or the vacuum filter 14. When clogging occurs, an alarm is issued by a lamp or buzzer.

The timing of performing the air blow in step 115 is particularly restricted as long as there is no molten metal in the sleeve 11 in which the suction ports 14 to 17 open, except immediately before the molten metal is supplied (poured) into the sleeve 11. There is no. For example, during the casting cycle, the injection plunger 12 may move forward in the sleeve 11 and reach the suction port farthest from the pouring port. Specifically, the injection plunger 12 may be used. After reaching the suction port 17 (fourth suction port 17) in FIG. 2, after the injection plunger 12 reaches the speed / pressure switching point described above, and further when opening the mold, the product is extruded. Advance of the injection plunger 11 in the operation of pushing the injection plunger in contact with the casting via the biscuits portion to the advance limit position so that the casting is securely held on the movable mold 22 side provided with the mechanism. It may be in a limited position. In addition, when the operation mode is selected by operating the switch for switching the operation mode of the die casting machine (1 cycle automatic operation mode / fully automatic operation mode at the start of casting) except during the casting cycle, when the switch is switched. , The air blow of step 115 may be automatically performed.

Although the flowchart has been described above, here, the sleeve is evacuated by using all the suction ports 14 to 17 from the first suction port to the fourth suction port, but in addition to this, the third suction port and the fourth suction port are used. The combination of the two mouths, the second suction port, the third suction port, and the fourth suction port is free. There is no limit to the number of suction ports that can be used.

Next, the use or non-use of the "upper limit sleeve filling rate" will be described. The "upper limit sleeve filling rate" means that when the filling rate (referred to as sleeve filling rate) of the molten metal 18 in the sleeve 11 rises to a predetermined value (for example, 80%), suction close to the cavity 23 from the suction port reached by the injection plunger 12 This is the upper limit of the sleeve filling rate when all the suction port selection valves 33 of the mouth are closed. Therefore, using the "upper limit sleeve filling rate" means that when the sleeve filling rate reaches a predetermined value, the suction port selection valve 33 belonging to the suction port close to the cavity 23 from the suction port reached by the injection plunger 12. Refers to closing all. The upper limit sleeve filling rate can be freely set before casting.
The purpose of using the upper limit sleeve filling rate is to prevent the molten metal debris from entering the suction path 51 from the suction ports 14 to 17 during evacuation due to the high sleeve filling rate, and from the suction port. It is used to evacuate the sleeve 11 with the maximum number of suction ports that does not allow molten metal debris to enter the suction path 51.

Next, with reference to FIGS. 6 and 7, another embodiment in which the vacuum filter 31 is not clogged will be described.
In the embodiment of FIG. 6, the space between the suction ports 14 to 17 of the sleeve 11 to the vacuum filter 31 of each suction path 51 is formed so as to rise upward from each suction port and then downward. Branch paths 52 and 53 are provided in the downward suction path. The lower end of the downward branch path 53 is a discharge port 57 for discharging the molten metal residue S, and the lateral branch path 52 is connected to the vacuum device via the vacuum filter 31. Other configurations are the same as those of one embodiment of FIG.
By evacuation, molten metal debris such as aluminum debris gets on the air flow and clogs the filter 31. This problem is solved in this embodiment. The debris of the molten metal sucked out from the inside of the sleeve 11 by evacuation first rises in the suction path 51 and then enters the suction path downward. The downward suction path is divided into branch paths 52 and 53, and the lateral branch path 52 is connected to the vacuum device via the vacuum filter 31, so that the suction path is toward the branch path 52. It is being sucked. However, since the molten metal residue S such as aluminum residue is heavy, it is not sucked to the branch path 52 side and falls into the aluminum residue box 54 having a closed structure connected to the discharge port 57 at the lower end of the branch path 53. In this way, the residue S of the molten metal is not sucked into the branch path 52 going in the lateral direction, and clogging of the vacuum filter 31 can be suppressed. The aluminum scrap box 54 is regularly cleaned. As a result, the cleaning frequency of the filter 31 can be reduced, and more stable operation can be performed. It should be noted that the smaller the volume of the aluminum scrap box 54, the smaller the amount of suction air in the box during vacuum suction, which is advantageous for the degree of vacuum, but if it is too small, the cleaning frequency of the box increases. A suitable volume is preferable in consideration of the degree of vacuum and the frequency of cleaning.

In the embodiment of FIG. 7, a ball valve (a type of on-off valve) 59 is added in front of the discharge port 57 of the branch path 53 going downward, with respect to the embodiment of FIG. The configuration is the same as that of the embodiment of FIG. 2 and the embodiment of FIG. The ball valve 59 is opened at the time of air blow by an electric or air-driven actuator 58. As a result, the molten metal residue S accumulated immediately before the ball valve 59 at the time of evacuation can be discharged to the aluminum residue box 54 by opening the ball valve 59 at the time of air blow. As a result, it is possible to automatically clean the molten metal residue S at the time of air blow. Then, the cleaning frequency of the vacuum filter 31 can be reduced, and more stable operation can be performed.

Further, the following embodiments of air blow work are also included in the present invention. When performing air blow work on the suction paths 51 (split paths 52 and 53) communicating with the suction ports 14 to 17 by switching the vacuum / air blow switching valve 35, all the suction port selection valves 33 are opened to add air. It is discharged from the pressure tank 38 toward the suction ports 14 to 17. In this case, if all the selection valves 33 are opened at the same time and the air blows, the air is preferentially discharged where it is not clogged, so that it is difficult to detect the clogged state of each suction port or pipe (suction path). Therefore, by opening each of the suction port selection bars 33 of 14, 15, 16 and 17 in order for a certain period of time, the molten metal residue S is removed from the pipe (suction path), and each pressure gauge 32 is used. It is good to detect clogging of each suction port and each pipe (suction path). This is a necessary device because there are a plurality of suction ports 14, 15, 16, and 17. Other configurations are the same as those of one embodiment of FIG.

Since the present invention has the above configuration, the following effects can be obtained.
The following effects were produced by providing a plurality of suction ports on the sleeve side on the sleeve and installing a suction port selection valve at each suction port so that the use or non-use of the suction port can be selected.
(1) Defect reduction, stable production Since there are multiple suction ports on the sleeve side, the suction area has increased and it has become possible to efficiently create a high vacuum state.
(2) Countermeasures against clogging of molten metal debris The suction port, which is easily clogged with molten metal debris, can be eliminated by using the suction port selection valve. That is, the vacuum time of the suction port on the sleeve side where the molten metal residue is easily clogged can be shortened, and the molten metal residue clogging can be suppressed.
(3) Stable production Since there are multiple suction ports on the sleeve side, vacuuming can be performed by suction ports other than the unnecessary suction ports, and non-defective products can be produced stably.
(4) Expansion of versatility and cost reduction It is not necessary to prepare a sleeve according to the mold and product, which leads to cost reduction. The number of sleeve types is reduced, making it easier to manage. Sleeve replacement time can be reduced.
(5) Defect reduction Since the area of the suction port on the sleeve side can be made larger than the suction area on the mold side, the effect of preventing pre-hot water due to vacuuming can be expected. By starting the sleeve vacuum first, it is possible to prevent the hot water more effectively. As a result, it is possible to reduce defects such as chipping, peeling, and shaving.

(6) Adjustable vacuuming time of each suction port By providing a suction port selection valve, the vacuuming time of each suction port can be adjusted by the position, time, filling rate, and the like.
(7) Stable production by suppressing the pressure rise of the vacuum tank The injection plunger can be closed immediately after passing through the suction port on the sleeve side (even while passing), so that the pressure rise of the vacuum tank can be suppressed and it is located far from the pouring port. Does not reduce the vacuum suction capacity of the suction port on the sleeve side.
(8) Since the injection plunger 12 can be set to evacuate through the suction ports 14 to 17 on each sleeve side until just before the completion of passage, the injection plunger 12 can be evacuated through the gap between the injection plunger 12 and the sleeve 11. , It is possible to prevent outside air from entering the sleeve 11 in the negative pressure state.

1 Injection device 2 Vacuum device 11 Sleeve 12 Injection plunger 13 Pouring port 14 Suction port (1st suction port)
15 Suction port (second suction port)
16 Suction port (3rd suction port)
17 Suction port (4th suction port)
18 Molten metal 21 Fixed mold 22 Movable mold 23 Cavity 31 Vacuum filter 32 Pressure gauge 33 Suction port selection valve 34 Distribution valve 35 Vacuum / air blow switching valve 36 Vacuum tank 37 Vacuum pump 38 Pressurized tank 39 Air source 40 Pressure gauge

Claims (7)

An injection device that injects molten metal into a casting device.
The injection device includes a suction port connected to the vacuum device via a suction path, a sleeve having a pouring port, and an injection plunger.
The vacuum device is
A suction port selection valve that allows you to select the use or non-use of vacuum suction by the vacuum device,
A pressure tank that stores air for blowing air through the suction path, and
A vacuum tank for evacuating the inside of the sleeve is provided.
The sleeve is provided with a plurality of the suction ports, and the suction port selection valve is installed in each of the suction paths connecting the suction ports and the vacuum device .
The vacuum device further comprises a vacuum filter between the plurality of suction ports of the sleeve and the plurality of suction port selection valves.
The space between the suction path connected to the suction port of the sleeve and the vacuum filter is formed so as to rise upward from each suction port and then downward, and a branch path is provided in the downward suction path. The lower end of the downward branch path is a discharge port for discharging the waste of the molten metal, and the lateral branch path is connected to the vacuum device via the vacuum filter . The injection device includes a detection unit that detects the position of the injection plunger, and detects that the injection plunger has passed through the pouring port and the plurality of suction ports in sequence by the detection unit, and each of the suction ports. The injection device according to claim 1, wherein the suction port selection valve installed corresponding to the above is closed sequentially or selectively. The injection device according to claim 1 or 2 , wherein the pressure of the suction path at the time of air blow is monitored by a pressure detection unit, and an alarm is issued when the pressure at the time of air blow rises and reaches a set value. The injection device according to any one of claims 1 to 3 , wherein the pressure detection unit monitors the degree of vacuum of each suction path corresponding to each suction port at the time of vacuum suction. In the casting method using the injection device according to claim 1, after the injection plunger starts advancing to close the pouring port, the vacuum tank evacuates the sleeve from the suction port of the sleeve. Steps to pull and
A step of closing the suction port selection valve according to the forward position of the injection plunger, and
A step of performing air blow from the suction port into the sleeve after the injection plunger reaches the suction port farthest from the pouring port.
Casting method. The casting method according to claim 5 , wherein in the step of carrying out the air blow, the injection plunger is retracted after the air blow is carried out. The casting method according to claim 5 or 6 , further comprising a step of monitoring the clogging of the vacuum filter by the pressure of the suction path by a pressure detecting unit.

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