Die Casting Machine

Abstract

To prevent the reduction of suction efficiency and clogging caused by the residence of molten metal scum or the like regarding a suction passage used for the vacuum suction of a die cast machine.SOLUTION: In a die cast machine 100 having a suction passage 51 used for vacuum suction, on the way of the suction passage (51 or 52) sucking a gas through suction ports (14 to 17 or 28) formed at a sleeve 11 or dies 21, 22, a correction structure 130 correcting molten metal scum S intruded into the gas is provided. The correction structure 130 comprises: a correction part 134 connected to the suction passage (51 or 52) and receiving the molten metal scum S; a first section 131 in the suction passage stretching from the upstream side toward the correction part 134; a section connection part 133 surrounding the first section 131 from the outside; and a second section 132 in the suction passage connected with the section connection part 133 at a position in which the first section 131 is surrounded by the section connection part 133.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a die casting machine having a suction path that draws a vacuum into a space that is formed by communicating from the internal space of a sleeve to a cavity. [Background technology]

[0002] As a conventional technique, for example, the prior art described in Patent Document 1 below is disclosed (see Figs. 1, 2 and 5).

[0003] This conventional technology involves connecting a burr suction prevention device main body to the outlet of a gas vent passage (so-called chill vent) that is carved in a wave-like shape into the mating surfaces of a pair of chill blocks, and connecting one end of a gas vent pipe, one end of which is connected to a vacuum device, to the burr suction prevention device main body to suck out and discharge various gases such as air and combustion gases of lubricating oil that are retained in the cavity, and to reduce the pressure in the cavity.

[0004] The main body of the burr suction prevention device receives and removes powder-like burrs that were generated during the previous casting and remain in the cavity after the mold is cleaned, just before the vacuum device, so that they do not pass through the gas vent passage together with various gases when the suction pressure in the cavity is reduced and reach the vacuum device. In other words, it prevents the burrs from being sucked into the vacuum device together with various gases and causing malfunction of the vacuum device.

[0005] The main body of this burr suction prevention device is constructed by cutting a square block body in a longitudinal direction at an angle to form a pair of block bodies with an inclined mating surface, and drilling a suction inlet, a suction outlet and a burr discharge outlet radially into the block body, with each outlet joining at the mating surface. One (Fig. 1) or several (Fig. 5) partition plates are arranged at an angle at the junction of the suction inlet and suction outlet, and a communication port is provided on part of the outer periphery of the partition plate to connect the suction inlet and suction outlet.

[0006] The partition plate is used to separate burrs from the gases that have entered the main body of the device from the suction inlet by colliding with the gases and changing the direction of flow of the burrs to an obtuse angle. The partition plate is formed in a disk shape with an outer diameter slightly larger than the inner diameters of the suction inlet, suction outlet and burr discharge outlet. The partition plate is disposed so as to close the junction of the suction inlet and suction outlet, which is an L-shaped junction in the drawing, except for a part of the elliptical opening edge of both ports (suction inlet, suction outlet) that open along the inclined mating surfaces of both block bodies (Figure 2), and a communication port that connects the suction inlet and suction outlet is provided between a part of the elliptical opening edge and a part of the outer periphery of the partition plate adjacent to that part.

[0007] As is well known in the art, the vacuum device is composed of an electromagnetic valve that is electrically connected to the drive source of the injection cylinder and opens the valve in response to the injection operation of the cylinder, a vacuum tank that stores suction force, and a vacuum pump.

[0008] The burr removal tank for receiving and accumulating the burrs discharged from the burr discharge port is formed airtight and receives and accumulates the burrs inside. It also has various built-in means for preventing backflow so that the accumulated burrs do not fly out of the burr removal tank when various gases are repeatedly sucked and discharged during each casting cycle (each cycle operation). It is also equipped with an opening and closing door so that the burrs accumulated in the burr removal tank can be removed.

[0009] The main body of the burr suction prevention device is constructed by disposing a partition plate along the inclined edge of a pair of block bodies having an inclined mating surface for butting against each other, so that a communication port for connecting the two ports (suction inlet, suction outlet) is formed between a part of the inclined opening edge of the inclined opening of both ports (suction inlet, suction outlet) located on the casting burr discharge port side of the inclined opening edge of both ports (suction inlet, suction outlet), and by interposing an O-ring between the mating surfaces near the periphery and fastening the two block bodies with bolts, and by screwing a connection plug into the suction inlet so as to protrude. The connection plug is inserted and connected to the outlet of the gas vent passage, and the main body of the burr suction prevention device is attached to the chill block set in the fixed mold with a bolt that penetrates both block bodies, and a gas vent pipe that is piping to a vacuum device is connected to the suction outlet of the main body of the burr suction prevention device, and a burr discharge pipe that is piping to a burr removal tank is connected to the burr discharge port.

[0010] The main body of the burr suction prevention device thus installed operates in a set sequence, which is known in the art, in which the electromagnetic valve of the vacuum device opens and the suction pressure in the cavity starts to be reduced, the burrs that pass through the degassing passage together with the various gases and enter the main body of the burr suction prevention device from the suction inlet collide with the partition plate, bounce back to the burr discharge port together with the various gases with their momentum and change direction at an obtuse angle. The burrs that collide with the partition plate and bounce back to the burr discharge port side are discharged from the burr discharge port through the burr discharge pipe by their own weight into the burr removal tank, and the various gases are sucked into the suction outlet side through the connecting port and are sucked out from the suction outlet through the gas vent pipe into the vacuum tank of the vacuum device by being sucked out.

[0011] In the case of a structure in which several partition plates are disposed at the junction of the suction inlet and suction outlet, and the casting burrs flowing together with the various gases collide in several batches, several spacer members (one in the figure) are sandwiched between the mating surfaces of a pair of block bodies, as shown in Fig. 5, and partition plates are disposed on the inclined opening edges of the passage openings and the suction outlet in the spacer members by the same interposing means as the partition plates described above, to provide communication openings connecting the passage openings and the suction outlet. In this case, the communication openings are provided on the opposite side to the opening position of the communication opening connecting the suction inlet and the passage openings, so that the flow state of the various gases from the suction inlet side to the suction outlet side is in a zigzag state where they collide.

[0012] By disposing several partition plates through several spacer members in this manner, even if the burrs that collide with the first partition plate are not entirely discharged from the burr discharge port and part of them enters the passage port from the communication port together with the gases, they will collide with the partition plates again and are separated from the gases by several collisions and are received in the passage port. It is also possible to connect a burr discharge pipe to the passage port in the same way as the burr discharge port so that the burrs received in the passage port can be discharged into the burr removal tank.

[0013] In addition, an air blowing device is provided which is connected to the gas venting pipe connected to the suction outlet of the main body of the burr suction prevention device through a branch pipe at the midway point of the gas venting pipe and opens an electromagnetic valve to periodically clean the inside of the main body of the burr suction prevention device. When air blowing, the mold is opened and the burr discharge pipe is removed. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] Publication number 2-4764 Summary of the Invention [Problem to be solved by the invention]

[0015] In the above-mentioned prior art, one or more partition plates are arranged at an inclination at the junction of the suction inlet and the suction outlet, and a communication port that connects the suction inlet and the suction outlet is provided on a part of the outer periphery of the partition plate. If the opening area of ​​the communication port is made large, the casting burr passes through the communication port together with various gases and is then sucked into the vacuum device, causing the vacuum device to malfunction, so it is necessary to make the opening area of ​​the communication port small. Therefore, there is a problem that a communication port with a small opening area becomes a throttling part in the vacuum suction path, which reduces the efficiency of vacuum suction and is disadvantageous to the degree of vacuum. This problem becomes more pronounced when multiple partition plates are arranged.

[0016] In addition, in the above-mentioned prior art, several partition plates are arranged at the junction of the suction inlet and suction outlet, and the casting burrs flowing together with the gases are caused to collide with the partition plates in several batches. Therefore, there is a problem that the casting burrs accumulate in the space between the partition plates, and the molten metal residue such as aluminum residue adheres to the partition plates themselves, clogging the vacuum suction path and making it impossible to perform stable production.

[0017] In addition, the above-mentioned prior art is provided with an air blowing device that periodically cleans the inside of the main body of the device for preventing suction of burrs by opening an electromagnetic valve, and is configured such that the mold is opened and the burr discharge pipe is removed during the air blowing operation. Therefore, when performing the air blowing operation, the work of removing the burr discharge pipe is required, which is disadvantageous in terms of work efficiency.

[0018] Furthermore, in the above-mentioned prior art, when the air blowing operation is performed, the mold is opened and the burr discharge pipe is removed. Therefore, when the burr discharge pipe is removed, the vacuuming operation cannot be performed, and the production is interrupted.

[0019] The present invention primarily relates to a suction path used for vacuum suction, and an object of the present invention is to provide a die casting machine capable of preventing a decrease in suction efficiency and clogging due to the accumulation of molten metal residue and the like. [Means for solving the problem]

[0020] The present invention is a die casting machine equipped with a suction path that draws a vacuum into a space formed by connecting the internal space of the sleeve to the cavity of the mold, and a collection structure that collects molten metal residue mixed into the gas is provided in the middle of the suction path through which gas is sucked in through a suction port formed in the sleeve or the mold. The collection structure comprises a collection section connected to the suction path for receiving the molten metal waste, a first section of the suction path extending from the upstream side of the suction path toward the collection section, a section connection section surrounding the first section from the outside and extending beyond the first section to the collection section, and a second section of the suction path connected to the section connection section at a position where the first section is surrounded by the section connection section. The first section and the second section communicate with each other via the inside of the section connection portion.

[0021] In the die casting machine of the present invention, it is preferable that the first section extends downward toward the collection section, and a height of the outlet of the first section is equal to or lower than a height of the inlet of the second section.

[0022] In the die casting machine of the present invention, it is preferable that the section connection portion includes a backflow prevention portion having an opening cross-sectional area smaller than that of the collection portion.

[0023] In the die casting machine of the present invention, it is preferable that the collection structure is provided in the collection section and includes an outlet through which the molten metal residue can pass, and a valve capable of opening and closing the outlet.

[0024] The invention described in claim 5 is A die casting machine having a suction path for vacuum suctioning a space formed by communicating from an internal space of a sleeve to a cavity, a first suction path communicating with the suction port and extending downward toward the aluminum waste box; The aluminum waste box communicated with the first suction path; A second suction path formed in communication with an internal space of the aluminum waste box; Equipped with The present invention relates to a die casting machine equipped with a suction path, characterized in that the height of the discharge outlet at the lower end of the first suction path is located below the height of the connection between the aluminum waste box and the second suction path.

[0025] The invention described in claim 6 is a ball valve provided at a position of the aluminum waste box lower than the height of a connection portion between the aluminum waste box and the second suction path; An aluminum waste receiver installed below the ball valve; The present invention relates to a die casting machine comprising:

[0026] The invention described in claim 7 is The die casting machine according to claim 5 or 6, characterized in that the suction port is provided in the sleeve.

[0027] The invention described in claim 8 is The die casting machine according to claim 5 or 6, characterized in that the suction port is provided in the die. Effect of the Invention

[0028] According to the present invention, since the side wall of the first section exists between the outlet of the first section and the inlet of the second section, in the process in which the gas flowing out of the first section flows around the outer periphery of the side wall of the first section and flows into the second section, the separation effect of the molten metal residue, etc. from the gas can be obtained by inertial force and centrifugal force, while the separation effect of the molten metal residue, etc. can also be obtained by the collision of the air flow with the pipe wall of the first section and the vicinity of the inlet of the second section. As a result, the gas from which the molten metal residue, etc. has been sufficiently separated flows into the second section. Therefore, the molten metal residue, etc. can be prevented from flowing out toward the vacuum filter or the valve through the second section, and the collection of the molten metal residue, etc. can be promoted. According to the present invention, the molten metal residue and the like can be sufficiently separated from the gas being sucked and collected in the collection section, thereby preventing the molten metal residue and the like from leaking into the second section, thereby preventing a decrease in the suction efficiency and blockage of the suction path.

[0029] The effects of the present invention will be described below using the wording of claims 5 to 8. According to the present invention, a die casting machine equipped with a suction path, which is characterized in that the height of the discharge port at the lower end of the first suction path is located below the height of the connection between the aluminum waste box and the second suction path, is configured to vacuum suction the space formed by communicating from the internal space of the sleeve to the cavity. Therefore, since no narrowing is generated in the vacuum suction path, the efficiency of vacuum suction is improved, which is advantageous for the degree of vacuum.

[0030] According to the present invention, the die casting machine is configured to vacuum suction the space formed by communicating the inner space of the sleeve to the cavity by using a suction path that includes a first suction path, an aluminum waste box, and a second suction path, and is characterized in that the height of the outlet at the lower end of the first suction path is located below the height of the connection between the aluminum waste box and the second suction path. Therefore, the molten metal waste such as aluminum waste falls downward into the inner space of the aluminum waste box and accumulates on the lower surface, so that the molten metal waste such as aluminum waste does not accumulate in spaces or gaps on the suction path where airflow occurs, and the molten metal waste such as aluminum waste does not adhere to the components themselves on the suction path where airflow occurs. Therefore, the vacuum suction path is not clogged, and stable production can be continued.

[0031] According to the present invention, the die casting machine is configured to vacuum suction the space formed by communicating the inner space of the sleeve to the cavity by using a suction path including a first suction path, an aluminum waste box, and a second suction path, and the height of the outlet at the lower end of the first suction path is set to be equal to or lower than the height of the connection between the aluminum waste box and the second suction path. Therefore, there is no need to remove the parts that make up the vacuum suction path when blowing air. Therefore, when performing the air blowing operation, there is no need to remove the parts on the vacuum suction path, which is advantageous in terms of work efficiency.

[0032] According to the present invention, the die casting machine is configured to vacuum suction the space formed by communicating the inner space of the sleeve to the cavity by using a suction path having a first suction path, an aluminum waste box, and a second suction path, the height of the outlet at the lower end of the first suction path being located below the height of the connection between the aluminum waste box and the second suction path. Therefore, there is no need to remove the parts that make up the vacuum suction path when blowing air. In other words, when performing air blowing, there is no need to remove the components on the vacuum suction path, and the vacuuming operation can be performed continuously, so there is an effect that production is not interrupted and can be continued.

[0033] Further, according to the present invention, a die casting machine equipped with a suction path, which is characterized in that the height of the position of the discharge port at the lower end of the first suction path is arranged below the height of the position of the connection part between the aluminum waste box and the second suction path, is configured to vacuum suction the space formed by communicating from the internal space of the sleeve to the cavity. Therefore, when air is blown, the ball valve opens, and the molten metal residue such as aluminum waste is automatically discharged from the lower surface of the aluminum waste box (upper surface of the ball valve) into the aluminum waste receiver, and cleaning work can be performed. In other words, even if production is ongoing, it is possible to periodically clean the molten metal residue such as aluminum waste that accumulates on the lower surface of the aluminum waste receiver. Therefore, there is an effect that production can be continued without interruption. [Brief description of the drawings]

[0034] [Figure 1] 1 is a schematic side view (partially including a cross-sectional view) of a die casting machine equipped with an injection device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of an injection device and a vacuum device according to the present invention. [Diagram 3] 1 is a diagram illustrating a molten metal supply process through an injection filling process according to an embodiment of the present invention. FIG. [Figure 4] 1 is a flowchart of a die casting method. [Diagram 5] 1 is a flowchart of a casting method using the vacuum device of the present invention. [Figure 6] FIG. 2 is a diagram showing a schematic diagram of a suction path and a molten metal waste collection structure according to the first embodiment of the present invention. [Figure 7] FIG. 7(a) is a diagram for explaining the action of the capture structure shown in FIG. 6, and FIG. 7(b) is a diagram showing another example. [Figure 8] FIG. 4 is a diagram showing a collection structure according to a first modified example of the first embodiment. [Figure 9]FIG. 11 is a vertical cross-sectional view showing a collection structure according to a second modified example of the first embodiment. [Figure 10] FIG. 11 is a diagram showing a schematic diagram of a suction path and a molten metal residue collection structure according to a second embodiment of the present invention. [Figure 11] 13 is a diagram showing a schematic diagram of a suction path and a collection structure according to a third embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Hereinafter, embodiments of the present invention will be described in order with reference to the drawings.

[0036] FIG. 1 is a schematic side view (partially 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.

[0037] In the die casting machine 100 of this embodiment, a movable die 22 is installed on the movable platen 4, and a fixed die 21 is installed on the fixed platen 5. The movable platen 4 moves on the machine base 8 toward the fixed platen 5 by a die opening / closing / die clamping mechanism (not shown) such as a toggle link mechanism or a ball screw mechanism. As a result, the movable die 22 and the fixed die 21 engage with each other and are clamped to form a cavity 23. Four tie bars 7 are inserted through the movable platen 4 and the fixed platen 5 via insertion holes, and the movable platen 4 moves freely forward and backward along the tie bars 7 relative to the fixed platen 5. The fixed die 21 and the movable die 22 engage with each other as shown in FIG. 1 to form a cavity (product portion) 23 therebetween, and a molten metal 18 such as aluminum or its alloy is injected and filled into the cavity 23 to produce a cast product.

[0038] The fixed platen 5 is provided with a sleeve (injection sleeve) 11. In order to inject the molten metal 18, a hydraulic cylinder (not shown) for driving is provided at the right end of a plunger rod 19 of the injection plunger 12, and the plunger rod 19 is connected to the cylinder rod of the hydraulic cylinder via a coupling (not shown). The fixed die 21 is provided with a sleeve 11 for storing the molten metal 18, and the sleeve 11 fits into a hole 10 provided in the fixed die 21 to form a molten metal storage chamber. This molten metal storage chamber is connected to the cavity 23 via a runner 24 and a gate 25. The molten metal 18 is poured from the pouring port 13 by a ladle 43 (FIG. 3(a)) of the melting machine, and then the molten metal 18 is pushed in by the injection plunger 12 to fill the cavity 23 with the molten metal 18. As an example of detecting the position of the injection plunger 12, a non-contact sensor detects a mark provided on the cylinder rod along the stroke of the hydraulic cylinder. Alternatively, the position may be detected by a switch lever provided on the plunger rod 19 and multiple fixed limit switches.

[0039] 2 is a schematic diagram of the injection device 1 and vacuum device 2 (vacuum suction system) of the present invention, and shows the configuration of the sleeve 11 of the die casting machine 100 of the present invention having multiple suction ports 14 to 17. The suction ports 14, 15, 16, and 17 are provided in order from the position closest to the pouring port 13 to the position farther from the mold side.

[0040] The inside of sleeve 11 of die casting machine 100 is connected to cavity 23 formed by fixed die 21 and movable die 22, and molten metal 18 poured into sleeve 11 from pouring port 13 by ladle 43 of the molten metal heater shown in Fig. 3(a) is injected into cavity 23 (into mold). Injection plunger 12 is disposed in sleeve 11, and by moving injection plunger 12 forward, injection plunger 12 pushes molten metal 18 from inside sleeve 11 into cavity 23.

[0041] In the present embodiment, the sleeve 11 has a plurality of holes on the upper side of the sleeve 11, and these holes are called suction ports 14 to 17. Air is removed from the inside of the sleeve 11 and the cavity 23 through the suction ports 14 to 17, and the inside of the sleeve 11 and the cavity 23 are evacuated to a vacuum. The suction of air from the cavity 23 may be performed at a suitable timing from the mold side through another vacuum line provided separately from the line of the vacuum tank 36. In the case of FIG. 1 and FIG. 2, the number of the suction ports 14 to 17 is four, but this is an example, and an appropriate number of ports may be one or more. The opening positions of the suction ports 14 to 17 do not necessarily have to be arranged at the same pitch or regularly, and may be arranged at different pitches or irregularly in consideration of the behavior of the molten metal in the sleeve 11. Similarly, the shapes and opening areas of the suction ports 14 to 17 do not necessarily have to be the same, and may be different shapes and opening areas in consideration of the behavior of the molten metal in the sleeve 11.

[0042] 3(a) to (d) are diagrams for explaining the molten metal supplying process to the injection filling process according to this embodiment. As shown in FIG. 3(a), the ladle 43 of the molten metal supplying machine pours the molten metal 18 from the pouring port 13 installed in the sleeve 11 (molten metal supplying process). As shown in FIG. 3(b), the injection cylinder is operated, and the injection plunger 12 at the tip of the plunger rod 19 pushes the molten metal 18 in the molten metal storage chamber out of the sleeve 11. Then, as shown in FIG. 3(c), the molten metal 18 is pushed out from the runner 24 and the gate 25 to fill the cavity 23 with the molten metal 18 (injection filling process). Specifically, the forward speed of the injection plunger 12 is set low (low speed region) until the pushed-out 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 switch point / VP switch point), the control of the forward movement of the injection plunger 12 is switched from speed control to pressure control (pressure holding control / pressure boost control). The molten metal 18 is then cooled in the mold while a holding pressure (pressure boost) is applied by the injection plunger 12, and when it has sufficiently solidified, the movable platen 4 returns to its original position on the left side in Figs. 1 and 3, and the mold opens. When the mold opens, multiple ejection pins 42 attached to an ejection plate 41 move forward to the right side in Fig. 1 by a hydraulic mechanism (not shown) to eject the product, and the product is then removed.

[0043] Next, as an example, an embodiment in which there are four suction ports 14 to 17 will be described below with reference to FIG. 2. In FIG. 2, the suction ports 14, 15, 16, and 17 are written as the first suction port, the second suction port, the third suction port, and the fourth suction port, respectively. The suction ports 14 to 17 are connected to the vacuum tank 36 by piping (also called suction paths). From each of the suction ports 14 to 17, first, via the vacuum filter 31, to the pressure gauge 32, the suction port selection valve 33, and the distribution valve 34, in that order, are configured as independent suction paths 51, and from the distribution valve 34, via the vacuum / air blow switching valve 35, the vacuum tank 36 is connected via the piping 55. In FIG. 2, the vacuum device 2 (vacuum tank 36) is above the sleeve 11, but this is not necessarily limited thereto, and the vacuum device 2 (vacuum tank 36) 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 a pressurized tank 38 via another pipe 56. And, an air source 39 (compressed air source) is connected to the pressurized tank 38.

[0044] In this embodiment, the suction port selection valve 33, which allows the use or non-use of the vacuum suction by the vacuum device 2 to be selected in each of the suction ports 14 to 17, is installed between the distribution valve 34 and the vacuum filter 31. The vacuum filter 31 is installed because molten metal residue may be drawn together with air when the inside of the sleeve 11 is suctioned to a vacuum. The vacuum filter 31 catches the molten metal residue and prevents it from being brought into the piping and each valve. The material of the vacuum filter 31 is preferably one that has a small exhaust resistance during vacuum suction and does not burn even if high-temperature molten metal residue enters it. In addition, an inexpensive and replaceable material, such as a metal material such as punched metal, meshed wire netting, or stainless steel scrubbing pad, is preferable.

[0045] In this embodiment, the pressure gauge 32 is installed in each of the suction paths 51 of the suction ports 14 to 17 between the vacuum filter 31 and the suction port selection valve 33. During vacuum suction, the pressure gauge 32 monitors the degree of vacuum in each of the suction paths 51 corresponding to each of the suction ports 14 to 17. Since the pressure gauge 32 monitors the degree of vacuum in each of the suction paths 51, the suction ports that are easily clogged with molten metal residue can be made unnecessary by the suction port selection valve 33. That is, by monitoring the degree of vacuum in each of the suction paths 51 with the pressure gauge 32, the vacuum suction time of the sleeve side suction port that is easily clogged with molten metal residue can be shortened, and clogging with molten metal residue can be suppressed. The pressure gauge 32 (pressure detection unit) may be a pressure gauge that can measure both abnormal negative pressure during evacuation and abnormal pressure (positive) during air blowing, but a pressure sensor that can measure both and transmit the measured pressure as an electric signal is more preferable. The pressure detection unit includes a pressure gauge, a compound pressure gauge, a pressure sensor, and the like.

[0046] When air is blown from the pressurized tank 38 to the suction ports 14-17, if the inside of the pipes or the vacuum filter 31 are clogged with molten metal residue, an abnormal pressure is indicated, so that clogging of the inside of the pipes or the vacuum filter 31 due to molten metal residue can be detected. In this case, if the pressure rises during air blowing and reaches a set value, an alarm is issued because the inside of the pipes or the vacuum filter 31 are clogged. When an alarm for clogging is issued, the work is stopped and the molten metal residue is cleaned. The suction ports that are easily clogged with molten metal residue can be made unnecessary by the suction port selection valve 33. Alternatively, the vacuum suction time can be shortened by closing the suction port selection valve 33 early, so clogging with molten metal residue can be suppressed.

[0047] During vacuum suction, it is possible to confirm that the vacuum suction operation has been performed normally by monitoring the vacuum level in the specified suction path 51 with the pressure gauge 32. In other words, this indicates that the vacuum / air blow switching valve 35 has operated normally. By checking whether each suction path 51 is not clogged with molten metal residue and whether the vacuum pumping operation has been performed normally, it can be determined whether the cavity 23 communicating with the sleeve 11 has also been vacuum pumped normally.

[0048] Next, the suction port selection valve 33 that allows the use or non-use of the vacuum suction by the vacuum device 2 to be selected at each of the suction ports 14 to 17 will be described. In the case of FIG. 1 and FIG. 2 of this embodiment, there are four suction ports, and one suction port selection valve 33 is attached to each of the suction ports 14 to 17. The suction port selection valve 33 that is "set for use" is opened when the inside of the sleeve 11 is evacuated or when air is blown at the suction ports 14 to 17. It is closed when there is no need to evacuate or when there is no need to blow air. The suction port selection valve 33 that is "set for non-use" is normally in a closed state. It may be opened when air is blown. The combination of the use and non-use settings of the four suction port selection valves 33 can be freely selected as appropriate.

[0049] The vacuum / air blow switching valve 35 is (1) Will the inside of the sleeve 11 and the cavity 23 be evacuated? (2) Will the inside of the piping be cleaned by air blowing? When selecting, i.e. In the case of (1) above, should the suction ports 14 to 17 be connected to the vacuum tank 36? In the case of (2) above, should the suction ports 14 to 17 be connected to the pressurized tank 38 (or air source 39)? This is a switching valve for switching between the vacuum piping 55 and the air blow piping 56 when selecting the above.

[0050] The air inside the vacuum tank 36 is constantly sucked out by a vacuum pump 37. The vacuum pump 37 is driven by a motor. The degree of vacuum in the vacuum tank 36 is monitored by a pressure gauge 40, which issues an alarm if the degree of vacuum falls below a set value. The degree of vacuum in the vacuum tank 36 needs to be maintained at approximately -95 kPa or less.

[0051] The air for air blow is temporarily stored in the pressurized tank 38 from the air source 39, and after the vacuum / air blow switching valve 35 is switched to air blow, the air passes through the vacuum / air blow switching valve 35 and reaches the suction ports 14 to 17. When the vacuum / air blow switching valve 35 is switched to air blow, for example, air is released from the pressurized tank 38 to the suction ports 14 to 17, and air blowing of the suction path 51 is performed.

[0052] As shown in FIG. 1, at the upper part of the mold, a chill vent 27 or a vacuum valve (not shown) is installed at the part where the fixed mold 21 and the movable mold 22 are joined, and the air in the cavity 23 is drawn from these parts (in the case of the chill vent 27, a connection port 28 provided at one or more places). The 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 simultaneously or at different timings. The chill vent 27 is often used when manufacturing a molded product of light metal by a high-pressure die casting method, and is a chiller used for degassing. When the gas in the cavity 23 is released, the chill vent 27 prevents the molten metal 18 from flowing out. 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.

[0053] 4 shows a flowchart of a die casting method. The flowchart starts with the start of die casting, followed by the steps of mold clamping, pouring molten metal, starting injection, and sleeve vacuum, in that order. If there is no sleeve vacuum step (if sleeve vacuum is not required), the steps proceed in the order of boost pressure switch command, cooling (solidification), mold opening, product removal, product detection, mold spray, injection retraction, and tip lubrication, before the next cycle begins. If sleeve vacuum is used in this step, the process proceeds to circuit A of the casting method of one embodiment of the present invention.

[0054] Hereinafter, the circuit A of the casting method according to the present invention will be described with reference to FIG. 5 and FIG. In step S101 (S101, the same applies below), it is confirmed whether the vacuum tank 36 has been sufficiently evacuated, and a signal indicating completion of preparation is issued. In step S102, after pouring, the injection plunger 12 advances to a position where it blocks the pouring port 13, and then starts the operation of drawing a vacuum in the sleeve 11. The position of the injection plunger 12 at this time is called the vacuum start position (Fig. 2). Reaching of the injection plunger 12 to the set vacuum start position is detected by detecting the stroke of the hydraulic cylinder that drives the injection plunger 12 with a non-contact sensor or the like. Reaching of the injection plunger 12 to each set position in the following steps is also detected in a similar manner. In step S102, after pouring, the injection plunger 12 advances, and when it reaches a position where it blocks the pouring port 13, the operation of drawing a vacuum in the sleeve 11 is started.

[0055] In step S103, the vacuum / air blow switching valve 35 is switched to the vacuum side. In step S104, injection plunger 12 reaches a set position (FIG. 2 / first suction port closing position) for closing first suction port . In step S105, in order to close first suction port 14, suction port selection valve 33 is closed.

[0056] In step S106, injection plunger 12 reaches a set position (FIG. 2 / second suction port closing position) for closing second suction port 15. In step S107, in order to close second suction port 15, suction port selection valve 33 is closed.

[0057] In step S108, injection plunger 12 reaches a set position (FIG. 2 / third suction port closing position) for closing third suction port 16. In step S109, in order to close the third suction port 16, the suction port selection valve 33 is closed.

[0058] In step S110, the injection plunger 12 reaches a set position (FIG. 2 / fourth suction port closing position) for closing the fourth suction port 17. Here, the pressure gauge 32 measures the degree of vacuum at the fourth suction port 17 just before the injection plunger 12 reaches the set position for closing the fourth suction port 17. The degree of vacuum at the fourth suction port 17 is managed by setting upper and lower limit ranges. If the degree of vacuum is outside the set range, an alarm is issued by a lamp, buzzer, etc. It is preferable that the upper and lower limit ranges are -90 to -100 kPa. In step S111, in order to close the fourth suction port 17, the suction port selection valve 33 is closed.

[0059] In step S112, the vacuum / air blow switching valve 35 is turned off. In step S113, all of the suction port selection valves 33 for the suction ports 14 to 17 are opened. In step S114, the vacuum / air blow switching valve 35 is set to air blow. In step S115, air is blown. At this time, the suction port selection valves 33 for the suction ports 14 to 17 may all be open, or the suction port selection valves 33 may be opened one by one in sequence. In step S116, the pressure in each suction path 51 of the suction ports 14 to 17 is measured by the pressure gauge 32 to determine whether there is clogging in the piping or the vacuum filter 31. If clogging occurs, an alarm is issued using a lamp, buzzer, or the like.

[0060] The timing of the air blow in step S115 is not particularly limited as long as there is no molten metal 18 in the sleeve 11 with the suction ports 14 to 17 open, except immediately before supplying (pouring) the molten metal 18 into the sleeve 11. For example, during the casting cycle, the air blow may be performed after the injection plunger 12 advances in the sleeve 11 and reaches the suction port farthest from the pouring port 13. Specifically, the air blow may be performed after the injection plunger 12 reaches the suction port 17 (fourth suction port 17) in FIG. 2, after the injection plunger 12 reaches the speed-pressure switching point described above, or even at the forward limit position of the injection plunger 12 in the operation of pushing the injection plunger 12, which is in contact with the casting via the biscuit portion, to the forward limit position so that the casting is reliably held on the movable die 22 side having a product ejection mechanism when the die is opened. In addition, when the operation mode of the die casting machine 100 (one-cycle automatic operation mode at the start of casting / fully automatic operation mode) is selected by operating a switch other than during the casting cycle, air blowing in step S115 may be performed automatically when the switch is operated to change the operation mode.

[0061] The flow chart has been described above. Here, all of the suction ports 14 to 17, from the first suction port 14 to the fourth suction port 17, are used to draw a vacuum in the sleeve 11, but other combinations are possible, such as using two ports, the third suction port 16 and the fourth suction port 17, or using three ports, the second suction port 15, the third suction port 16, and the fourth suction port 17. Furthermore, there is no limit to the number of suction ports to be used.

[0062] Next, whether to use the "upper sleeve filling rate" will be described. The "upper sleeve filling rate" is the upper limit of the sleeve filling rate when the filling rate of the molten metal 18 in the sleeve 11 (called the sleeve filling rate) rises to a predetermined value (e.g., 80%) and all of the suction port selection valves 33 belonging to the suction port closest to the cavity 23 from the suction port reached by the injection plunger 12 are closed. Therefore, using the "upper sleeve filling rate" means that when the sleeve filling rate reaches a predetermined value, all of the suction port selection valves 33 belonging to the suction port closest to the cavity 23 from the suction port reached by the injection plunger 12 are closed. The upper sleeve filling rate can be freely set before casting.

[0063] The purpose of using the upper limit sleeve filling rate is to prevent molten metal residue from entering the suction path 51 from the suction ports 14-17 when the sleeve filling rate becomes high and to draw a vacuum on the sleeve 11 using the maximum number of suction ports that does not allow molten metal residue to enter the suction path 51 from the suction ports 14-17.

[0064] [First embodiment] Now, a first embodiment of the present invention and its modified examples will be described with reference to Fig. 6 to Fig. 9. The first embodiment and the modified example of the first embodiment, as well as a second embodiment described next, relate to a countermeasure against clogging of the suction path 51. Such a countermeasure against clogging can be applied to the die casting machine 100.

[0065] The first embodiment shows a configuration related to a die casting machine having a suction path 51 (FIG. 2) that draws a vacuum into a space formed by communicating from the internal space of the sleeve 11 to the cavity 23. Here, the suction path 51 that draws the internal space of the sleeve 11 from each of the suction ports 14 to 17, which are a plurality of holes opened in the sleeve 11, will be described. However, as long as the suction path 51 can draw a vacuum in the space formed by communicating from the internal space of the sleeve 11 to the cavity 23, it may be connected to another hole or opening provided in the sleeve 11 or to a passage provided in the injection plunger 12, for example, a passage extending in the axial direction from the plunger tip to the rear end of the injection plunger 12. The suction path 51 may be connected to only one suction port formed in the sleeve. Furthermore, the suction path 51 is not limited to being connected to a hole or opening of the sleeve 11 or injection plunger 12 of the injection device, but may be connected to a connecting port 28 (Figure 2) provided at one or more locations on the mold. The suction path for suctioning the inside of the cavity 23 will be described later with reference to FIG.

[0066] 6 shows a collection structure 130 provided in the middle of the suction path 51 through which gas is sucked from the inside of the sleeve 11 through the suction port 14. The collection structure 130 separates and collects molten metal residue S and the like mixed in the gas sucked toward the vacuum tank 36 through the suction path 51 constituting the above-mentioned vacuum device 2 (FIG. 2). The collection structure 130 collects the molten metal residue S and the like, thereby preventing a decrease in suction efficiency and clogging of the suction path 51 due to the molten metal residue S and the like remaining in the suction path 51.

[0067] When the vacuum device 2 includes a vacuum filter 31 (FIG. 2), the collection structure 130 is provided upstream of the vacuum filter 31 in the flow of gas sucked through the suction path 51. In this case, the collection structure 130 prevents the vacuum filter 31 from becoming clogged. However, by using the collection structure 130 of this embodiment, the vacuum filter 31 can be omitted from the vacuum device 2.

[0068] The collecting structure 130 may be provided in the suction passage 51 corresponding to the suction port 14 as well as in any of the suction passages 51 corresponding to the suction ports 15 to 17. Note that the collecting structure 130 may be provided only in at least one of the suction passages 51 corresponding to the suction ports 14 to 17 that is particularly susceptible to clogging by the molten metal residue S or the like.

[0069] The collection structure 130 includes a first section 131 which is a part of the suction path 51, a second section 132 which is a part of the suction path 51, a section connection section 133, and a collection section 134. The collector 134 is connected to the suction path 51 and receives the molten metal residue S, which is droplets and solidified pieces of the molten metal. In addition to the molten metal residue S, foreign matter such as dust and excess oil-based or water-soluble lubricant used to lubricate the plunger tip may be mixed into the gas sucked from the inside of the sleeve 11. In addition to the molten metal residue S, foreign matter such as dust and excess oil-based or water-soluble release agent may be mixed into the gas sucked from the cavity 23. The collector 134 receives and retains the molten metal residue S, foreign matter, lubricant, release agent, etc., which are heavy and denser than the gas. In this specification, the molten metal residue S, foreign matter, lubricant, release agent, etc. are referred to as "molten metal residue, etc."

[0070] 6, the collection section 134 is formed integrally with the section connection section 133 in a cylindrical shape, but this is not limited thereto. The collection section 134 and the section connection section 133 may be separate bodies and joined together. The collection section 134 may have any suitable shape as long as it can collect the molten metal residue S separated from the gas and retain it therein, and may be formed, for example, in a box shape with a rectangular cross section. The section connection section 133 is also not limited to a cylindrical shape and may have any suitable shape.

[0071] Taking into consideration the expected amount of molten metal residue S and the like mixed into the gas and the frequency of cleaning of the collection section 134, etc., the collection section 134 can be given an appropriate volume so as to ensure an appropriate distance between the accumulated molten metal residue S and the inlet 132A of the second section 132.

[0072] First section 131 is a part of the piping extending upstream of collection section 134, that is, from suction port 14 side (or suction ports 15 to 17 side), and extends downward toward collection section 134. In the piping of the suction path 51, a region 51A between the suction port 14 (or 15-17) located at the upper part of the sleeve 11 and the collection part 134 typically rises upward from the suction port 14 (or 15-17), passes through a horizontal section, and then curves downward. In other words, the region 51A is curved in an upwardly convex state. The first section 131 corresponds to the section in the region 51A that extends downward toward the collection part 134.

[0073] The region 51A can be configured by assembling a plurality of pipes. In order to prevent the molten metal residue S and the like from accumulating on the inner wall of the pipe, it is preferable to use a pipe having a smooth inner wall in the region 51A.

[0074] The piping of the suction path 51 is routed appropriately according to the space allowed for installation of the piping, the position of the support that supports the piping, or to avoid interference between the piping. Therefore, the region 51A may be curved in a more complicated shape than the inverted U-shape shown in the figure.

[0075] The section connection part 133 surrounds the first section 131 from the outside and extends downward beyond the outlet 131A at the lower end of the first section 131 to the collection part 134. It is sufficient that the section connection part 133 surrounds at least the vicinity of the lower end part of the first section 131. Taking into account factors such as the resistance of the airflow flowing out of the first section 131 and passing between the side wall 131B of the first section 131 and the inner wall 133A of the section connection section 133, an appropriate diameter can be given to each of the first section 131 and the section connection section 133.

[0076] The axis of the section connection part 133 and the axis of the first section 131 arranged inside the section connection part 133 do not necessarily need to coincide. For example, the first section 131 may be offset to the left in Fig. 6 with respect to the section connection part 133. In this case, the distance between the inner wall 133A and the side wall 131B on the right side of the section connection part 133 to which the second section 132 is connected is wider than the distance between the inner wall 133A and the side wall 131B on the left side of the section connection part 133 shown in Fig. 6.

[0077] The second section 132 is continuous with the section connection part 133 at a position where the first section 131 is surrounded by the section connection part 133. In the example shown in Fig. 6, the second section 132 is formed integrally with the section connection part 133 and the collection part 134, but this is not limited thereto. An inlet 132A of the second section 132 opens at the inner periphery of the section connection part 133. The inlet 132A faces the side wall 131B of the first section 131.

[0078] The first section 131 and the second section 132 communicate with each other through the inside of the section connection section 133, forming a flow path 130F for the gas to be sucked. The first section 131 extends in the up-down direction (vertical direction), and the second section 132 opens in the horizontal direction to the inner wall 133A of the section connection section 133. The gas flow flowing downward from the first section 131 turns around inside the section connection section 133 and flows into the second section 132 connected to the inner wall 133A of the section connection section 133. Therefore, a curved flow path 130F is formed across the first section 131, the section connection section 133, and the second section 132. The flow of gas flowing through the flow path 130F is shown diagrammatically by arrows in FIG. 6.

[0079] The second section 132 may be disposed at a position indicated by a two-dot chain line so that the gas flowing out of the first section 131 is redirected toward the left side of Fig. 6. In this case as well, the same effect as that obtained by the trapping structure 130 of this embodiment can be obtained.

[0080] It is also permissible that the first section 131 is inclined with respect to the vertical direction, and that the inlet 132A of the second section 132 opens in an orientation inclined with respect to the horizontal direction in the inner wall 133A of the section connection part 133. The second section 132 may extend obliquely upward or downward from the inner wall 133A. Although the second section 132 shown in FIG. 6 extends in the horizontal direction, this is not necessarily limited to this, and the second section 132 may extend in any direction from the connection point with the section connection portion 133.

[0081] The height H1 of the outlet 131A of the first section 131 is preferably equal to or less than the height H2 of the inlet 132A (opening) of the second section 132, which is the connection between the section connection section 133 and the second section 132 (H1≦H2, L≧0). H1 and H2 are heights from the same reference position. Here, the height H2 of the inlet 132A means the height at the lower end of the inlet 132A. In other words, it is preferable that the first section 131 extends to the position of the lower end of the inlet 132A of the second section 132, or extends below the position of the lower end of the inlet 132A. Flow path 130F flows out downward from outlet 131A of first section 131, then flows upward beyond outlet 131A inside the section connection portion 133, and then flows radially outward relative to the axis of first section 131, and flows into inlet 132A of second section 132.

[0082] Based on the embodiment shown in FIG. 6 and described above, the requirements for the collection structure 130 are briefly described. The collection structure 130 includes: (1) a first section 131 that is connected to the suction port 14 (or 15 to 17) and extends downward toward the collection section 134; (2) a molten metal waste box (section connection section 133 and collection section 134) connected to the first section 131; (3) a second section 132 formed in communication with the internal space of the molten metal waste box; It is equipped with: Furthermore, in the trapping structure 130, it is preferable that the height H1 of the outlet 131A of the first section 131 is equal to or smaller than the height H2 of the connection point (inlet 132A) between the section connection part 133 and the second section 132. Specifically, the distance L corresponding to the difference between the height H1 and the height H2 satisfies the relationship of the following formula (1). L ≧ 0 (1) If L≧0, when the opening of the inlet 132A of the second section 132 is projected onto the side wall 131B of the first section 131, both the upper end (12 o'clock position) and the lower end (6 o'clock position) of the opening of the inlet 132A will be within the projection range R1.

[0083] The action of the collection structure 130 will be described. The molten metal waste S and the like sucked together with gas from inside the sleeve 11 through the suction port 14 (or 15 to 17) into the suction path 51 by vacuum drawing flows through the first section 131 toward the collection section 134. When gas flows out of the first section 131 by drawing a vacuum, it turns around inside the section connection part 133 and is sucked toward the second section 132, but the molten metal waste S and the like, which has a larger inertial force than the gas, moves almost straight downward from the lower end of the first section 131 along the extension direction of the first section 131, and is separated from the gas. The molten metal waste S and the like separated from the flow of gas flowing into the second section 132 is captured by the collection part 134. The molten metal waste S and the like falls through the internal space of the collection part 134 and accumulates at the bottom of the collection part 134.

[0084] In addition to the inertial force, the molten metal residue S and the like mixed in the gas are separated from the gas by centrifugal force. That is, the centrifugal force acting on the gas flowing out of the first section 131 and turning toward the second section 132 separates the gas and the molten metal residue S and the like based on the difference in density between the gas and the molten metal residue S. Here, the first section 131 and the second section 132 are not directly connected to each other, but are connected to each other via a section connection portion 133 that surrounds the first section 131. Moreover, the second section 132 is connected to the section connection portion 133 at a position where the first section 131 is surrounded by the section connection portion 133. Therefore, the side wall 131B of the first section 131 exists within a projection range R1 ( FIG. 7(a) ) of the inlet 132A of the second section 132 onto the first section 131. The above configuration is shown enlarged in FIG.

[0085] According to the above configuration, while a path for vacuum suction is secured from the first section 131 to the second section 132, the side wall 131B can prevent gas from flowing directly from the first section 131 to the second section 132. Here, as shown in another example in FIG. 7(b), even when gas flows directly from the first section 131 to the second section 132, it has been confirmed through tests that the molten metal residue S and the like separated from the gas by inertial force and centrifugal force are generally collected. In addition, the second section 132 is positioned at the position indicated by the two-dot dashed line, and even when the gas flowing out of the first section 131 turns toward the left side of Figure 7(b), it shows the same collection efficiency as when it turns toward the right side. 7(a), in this embodiment, the second section 132 is connected to a section connection portion 133 that surrounds the first section 131. It has been confirmed by tests that this embodiment has a higher efficiency in collecting the molten metal residue S and the like, and is more effective in restricting the inflow of the molten metal residue S and the like into the second section 132, compared to a case in which gas flows directly from the first section 131 to the second section 132.

[0086] The operation of the trapping structure 130 of this embodiment will be described below with reference to Fig. 7(a) and another example shown in Fig. 7(b). In the example shown in Fig. 7(b), the outlet 131A of the first section 131 is located above the inlet 132A of the second section 132. The side wall 131B of the first section 131 does not exist within the projected area of ​​the inlet 132A.

[0087] In this embodiment (Figure 7(a)), the first section 131 is longer than the example shown in Figure 7(b), and therefore the side wall 131B of the first section 131 is present within the projection range R1 of the inlet 132A of the second section 132, so that the gas flowing out from the first section 131 flows around the outer periphery of the first section 131 before flowing into the second section 132. 7(b), the gas flowing out of the first section 131 flows directly into the second section 132. This is the same as when the first section 131 does not exist inside the section connection portion 133.

[0088] According to this embodiment, based on the arrangement of the outlet 131A of the first section 131 surrounded by the section connection section 133 and the inlet 132A of the second section 132 opened to the inner wall 133A of the section connection section 133, the airflow bends at multiple points from the outlet 131A to the inlet 132A as shown in Fig. 7(a). Specifically, the airflow bends so as to turn back from the outlet 131A to the outer periphery of the first section 131, and while a part of the airflow is blown against the side wall 131B of the first section 131, it is turned toward the second section 132. In this process, the airflow collides with the vicinity of the lower end of the first section 131 and the peripheral portion of the inlet 132A of the second section 132. In this way, while the inertial force and centrifugal force can be used to separate the molten metal residue S and the like from the gas at each of the bent points, the collision of the air flow with the vicinity of the lower end of the first section 131 and the peripheral portion of the inlet 132A of the second section 132 can also be used to separate the molten metal residue S and the like.

[0089] In this embodiment, since the side wall 131B of the first section 131 exists between the outlet 131A of the first section 131 and the inlet 132A of the second section 132, the gas from which the molten metal residue S and the like have been sufficiently separated flows into the second section 132 in the process of the gas flowing out from the outlet 131A flowing around the outer periphery of the side wall 131B and reaching the inlet 132A. Therefore, it is possible to prevent the molten metal residue S and the like from flowing out toward the vacuum filter 31 or the selection valve 33 through the second section 132, and to promote the collection of the molten metal residue S and the like by the collection section 134.

[0090] As described above, according to this embodiment, compared to the example shown in Figure 7 (b), the molten metal residue S and the like can be more thoroughly separated from the suctioned gas and collected in the collection section 134, thereby preventing the molten metal residue S and the like from leaking into the second section 132, and thus preventing a decrease in the suction efficiency and blockage of the suction path 51. Therefore, even if piping having a smooth inner wall is used in the first section 131 to prevent the accumulation of molten metal waste S and the like, it is possible to use bellows-shaped piping (bellows pipe), which has a high degree of freedom in installation, in the second section 132 and the piping closer to the vacuum tank 36 than that. The use of bellows-shaped piping in the area 51A is also permitted.

[0091] The collection section 134 is to be cleaned periodically to remove the molten metal residue S and the like accumulated therein. This reduces the amount of the molten metal residue S and the like sucked into the second section 132, so that when a vacuum filter 31 is used, it becomes possible to reduce the frequency of cleaning the vacuum filter 31, and stable operation can be achieved by suppressing the decrease in the suction efficiency of the suction path 51. A smaller volume of collection section 134 is advantageous for the degree of vacuum because less air needs to be sucked in, improving the efficiency of vacuum suction. However, if the volume of collection section 134 is too small, collection section 134 needs to be cleaned more frequently, so it is advisable to appropriately determine the volume of collection section 134 taking into consideration the degree of vacuum and the frequency of cleaning.

[0092] According to this embodiment, unlike conventional sleeve vacuum suction in which the suction holes and paths tend to be quickly clogged due to molten metal debris, it is possible to avoid clogging of the suction path and a decrease in suction efficiency and achieve stable suction inside the sleeve 11. According to this embodiment, it is not necessary to perform vacuum suction by suppressing the degree of vacuum and the molten metal filling rate inside the sleeve 11 in order to avoid clogging of the path, so it is possible to achieve sleeve vacuum suction with a high degree of vacuum and a high filling rate.

[0093] 6 and 7(a), it is preferable that the height H1 of the outlet 131A of the first section 131 is equal to or less than the height H2 of the inlet 132A of the second section 132 (H1≦H2). In this case, the gas flowing out from the first section 131 flows around the outer periphery of the side wall 131B as a whole, collides with the lower end of the first section 131 and the periphery of the inlet 132A, and flows into the second section 132. Therefore, the molten metal residue S, etc. mixed in the gas is separated and collected from the gas before it reaches the inlet 132A from the outlet 131A, and the inflow of the molten metal residue S, etc. into the second section 132 is suppressed, which is highly effective in preventing a decrease in the suction efficiency and blockage of the suction path 51.

[0094] Here, the greater the H2-H1 (distance L), the more effectively the molten metal residue S and the like can be prevented from flowing into the second section 132. The difference between the heights H1 and H2 can be determined appropriately taking into consideration the efficiency of separation and collection of the molten metal residue S and the like from the gas, and the pressure loss imparted to the airflow by the vicinity of the lower end of the first section 131 and the periphery of the inlet 132A. As an example, the distance L can be set to 5 mm. When a test was conducted on an actual die-casting machine in which the distance L = 5 mm was applied to perform vacuum suction inside the sleeve 11, the molten metal residue S and the like were collected in the collection section 134 and hardly flowed into the second section 132, so that the vacuum filter 31 can be omitted from the vacuum device 2. According to the test, the molten metal residue S and the like did not adhere to the filter of the Y-type strainer installed upstream of the selection valve 33.

[0095] Even if the distance L is 5 mm or less, or the height H1 is greater than the height H2, so long as even a small amount of the side wall 131B of the first section 131 is present within the projection range R1 of the inlet 132A, at least a part of the gas flowing out from the first section 131 flows around the outer periphery of the first section 131 inside the section connection part 133 surrounding the first section 131 and flows into the second section 132. The molten metal waste S and the like are sufficiently separated and collected from the flow, thereby preventing the molten metal waste S and the like from flowing out into the second section 132 and preventing a decrease in the suction efficiency or blockage of the suction path 51.

[0096] Near the lower end of the first section 131, a large number of narrow gaps can be formed by using a mesh, punched metal, or the like. The openings of the narrow gaps should be set to a size that prevents the molten metal waste S from passing through. By forming the narrow gaps, the first section 131 can function as a wall that prevents the molten metal waste S, etc. from flowing into the second section 132, while reducing the resistance to the airflow flowing out of the first section 131 and heading toward the second section 132. By forming a narrow gap in the first section 131, the distance L is kept long, effectively preventing the inflow of molten metal waste S and the like into the second section 132, while suppressing pressure loss caused by resistance to the airflow by the first section 131.

[0097] [First Modification of the First Embodiment] 8, the first section 131 may extend horizontally, and the second section 132 may extend upward (or downward) relative to a section connection portion 133 that surrounds the first section 131. The collection portion 134 is connected to the section connection portion 133 downward.

[0098] 8, similarly to the third embodiment, the gas flowing out from the first section 131 flows around the outer periphery of the side wall 131B and into the second section 132. Therefore, the molten metal residue S and the like can be separated from the gas and collected by inertial force, centrifugal force, and collision of the airflow with the side wall 131B and the inner wall 133A of the section connection part 133. The molten metal residue S and the like separated from the gas accumulate on the inner wall of the section connection part 133 and inside the collection part 134 due to their own weight.

[0099] 8, the positional relationship between the outlet 131A of the first section 131 and the inlet 132A of the second section 132 can be determined in the same manner as in the third embodiment. It is preferable that the position Ps1 of the outlet 131A in the extension direction D4 of the first section 131 is located forward in the extension direction D4 (toward the tip of the arrow) compared to the position Ps2 of the inlet 132A. The difference between the positions Ps1 and Ps2 corresponds to the difference (distance L) between the heights H1 and H2 described above.

[0100] [Second Modification of the First Embodiment] 9 shows more specifically the trapping structure 130. Components similar to those of the trapping structure 130 shown in FIG. 6 are given the same reference numerals. The collection structure 130 shown in FIG. 9 includes a first section 131, a second section 132, a section connection portion 133, and a collection portion 134. 6, the second section 132 is connected to the section connection part 133 at a position where the first section 131 is surrounded by the section connection part 133. The difference (distance L) between the heights H1, H2 of the outlet 131A and the inlet 132A is, for example, 5 mm.

[0101] 9, the section connection part 133 and the collection part 134 are separate bodies and are assembled by their respective flanges 133F, 134F. The flanges 133F, 134F are butted against each other with a circular center ring 135 sandwiched therebetween and are restrained by a clamp 136. The center ring 135 includes an O-ring 135A and a metal ring 135B that supports the O-ring 135A from the inner periphery side against a pressure reduction in the collection part 134 due to vacuum suction.

[0102] Collection section 134 is made up of pipe 134A and cover member 134B that is screwed onto the lower end of pipe 134A. The length of collection section 134 can be extended by adding another pipe and a connecting member (nipple) with male threads on both ends to collection section 134, thereby increasing the volume of collection section 134.

[0103] The diameter of the lower end of the section connection part 133 gradually decreases toward the collection part 134, and a flange 133F is provided at the lower end of the section connection part 133. This flange 133F functions as a backflow prevention part having an opening cross-sectional area smaller than that of the collection part 134. This backflow prevention part prevents the molten metal residue S and the like from flowing back from the inside of the collection part 134 to the outside. The cross-sectional area of ​​the inner opening of flange 133F is smaller than the cross-sectional area of ​​the inner opening of flange 134F of collection portion 134 against which flange 133F abuts via center ring 135. The ratio of the inner diameter of flange 133F to the inner diameter of collection portion 134 can be set to, for example, 1.5 to 3 times, but is not limited to this.

[0104] Since the backflow prevention section (flange 133F) is disposed between the collection section 134 and the second section 132, even if the molten metal residue S and the like accumulated in the collection section 134 is blown up by the air current and flows upward, the backflow prevention section (flange 133F) prevents the molten metal residue S and the like from flowing out of the collection section 134, and the molten metal residue S and the like can be retained inside the collection section 134. As described above, the suction path 51 is used for both vacuum suction and air blowing. The backflow prevention section can prevent the molten metal residue S and the like from flowing out of the collection section 134 during air blowing. When switching between vacuum suction and air blowing, it is not necessary to change the components of the suction path 51, including the collection structure 130, so that the suction path 51 can be assembled without the need for assembly work, and production can be continued.

[0105] The first section 131 is manufactured to include a flange 131F obtained by drilling holes in a circular blank flange, and cylindrical bodies 131D and 131E (pipes, nipples, etc.) joined by welding to the upper and lower surfaces around the holes of the flange 131F. The gap between the upper end 133B of the section connection part 133 and the outer circumferential part 131C of the first section 131 is sealed by interposing an annular center ring 137 between a flange 131F of the first section 131 and a flange 133G of the section connection part 133. The flange 133G and the flange 131F are restrained by a clamp 138.

[0106] A bellows-shaped pipe 139 is connected to the second section 132 via a center ring 137. Since the molten metal residue S and the like mixed in the gas can be sufficiently removed by the collection structure 130, the bellows-shaped pipe 139 can be used, which has a higher degree of freedom in installation compared to a pipe that does not have flexibility.

[0107] 9, a backflow prevention part (flange 133F) having an opening concentric with the axis of section connection part 133 and collection part 134 is disposed at the joint between section connection part 133 and collection part 134. This example is not limited to this, and collection structure 130 may include a backflow prevention part having an opening eccentric with the axis of section connection part 133 and collection part 134, or a semicircular backflow prevention part. Such a backflow prevention part is not limited to the joint between section connection part 133 and collection part 134, and may be disposed, for example, inside pipe 134A of collection part 134.

[0108] Second Embodiment Next, a second embodiment of the present invention will be described with reference to Fig. 10. The capturing structure 140 shown in Fig. 10 includes a ball valve 141 capable of opening and closing an outlet 144A provided in a capturing section 144. Except for this, the capturing structure 140 is configured similarly to the capturing structure 130 of the third embodiment. The capturing section 144 is formed integrally with the section connection section 133. The following description will focus on the differences from the trapping structure 130 of the first embodiment. The collecting section 144 has at its lower end an outlet 144A through which the molten metal waste S and the like can pass.

[0109] Ball valve 141 includes ball 141A as a valve body, and housing 141B in which a valve seat for receiving ball 141A is provided. Ball valve 141 is opened and closed by rotating ball 141A around axis 141C perpendicular to a passage (bore) inside housing 141B. According to the collection structure 140, it is possible to collect the molten metal residue S and the like by closing the ball valve 141, and to discharge the molten metal residue S and the like by opening the ball valve 141.

[0110] The location of the outlet 144A is not necessarily limited to the lower end of the collection section 144. Even if the outlet 144A is provided in the side wall 144B of the collection section 144, the molten metal residue S and the like can be discharged by the pressure of the airflow during air blowing. Moreover, regardless of the position of the outlet 144A, the molten metal waste S and the like can be taken out from the outlet 144A by manually opening the ball valve 141.

[0111] The collection structure 140 includes: (1) The collection section 144 is provided with a ball valve 141 (a type of on-off valve) capable of opening and closing the outlet 144A, which is provided at a position lower than the height H2 of the connection point (inlet 132A) between the section connection section 133 and the second section 132. (2) It is preferable to provide a molten metal waste receiver 142 below the ball valve 141 to receive the molten metal waste S and the like.

[0112] The ball valve 141 is driven by an actuator 143 that is electrically or air (compressed air) driven, thereby opening and closing the outlet 144A. When the outlet 144A is closed by the ball valve 141 and vacuum suction is performed through the suction path 51, the molten metal residue S and the like separated from the gas are collected inside the collection section 144. When the outlet 144A is opened by the ball valve 141, the molten metal residue S and the like accumulated inside the collection section 144 can be discharged to the outside of the collection section 144. In the example shown in Fig. 10, the molten metal residue S and the like fall into the molten metal residue receiver 142 from the open outlet 144A.

[0113] The ball valve 141 is preferably opened when air is blown through the suction path 51. By opening the ball valve 141 when air is blown, the molten metal residue S and the like collected inside the collection part 144 during vacuum suction can be discharged to the outside of the collection part 144. In addition to the ball 141A moving when the ball valve 141 is opened, the pressure of the airflow during air blowing also acts, so that the molten metal residue S adhering to the ball 141A can also be detached from the ball 141A and discharged to the outside.

[0114] By opening the ball valve 141 with the actuator 143 when air is blown, the molten metal residue S and the like can be automatically discharged to the outside of the collection section 144 when air is blown. The molten metal residue S and the like are removed from the inside of the collection section 144 each time air is blown, so the amount of the molten metal residue S and the like that accumulates in the collection section 144 can be reduced. This effectively reduces the amount of the molten metal residue S and the like that is sucked into the second section 132 that communicates with the collection section 144, which also contributes to reducing the frequency of cleaning the vacuum filter 31. In this embodiment, since the molten metal residue S and the like are discharged to the outside of the collection section 144, it is sufficient to clean the molten metal residue receiver 142 on which the molten metal residue S and the like have accumulated.

[0115] The larger the volume of the molten metal waste receiver 142, the less frequently it needs to be cleaned, which is advantageous in terms of work efficiency. It is preferable that the volume of the molten metal waste receiver 142 be appropriately determined in consideration of work efficiency and the manufacturing cost of the molten metal waste receiver 142.

[0116] According to the collection structure 140 of this embodiment, the ball valve 141 can be opened during air blowing to discharge the molten metal residue S and the like from the inside of the collection section 144 into the molten metal residue receiver 142, so that the molten metal residue S and the like collected during vacuum suction can be automatically and periodically removed from the collection section 144, allowing continuous production.

[0117] Instead of ball valve 141, other valves capable of reliably closing outlet 144A of collection section 144 during vacuum suction, such as a butterfly valve or a gate valve, may be used.

[0118] Third Embodiment With reference to FIG. 11, a structure relating to a suction path 52 through which gas is sucked from the cavity 23 through the cavity suction port (connecting port 28) formed in the molds 21 and 22 will be described. The suction path 52, like the above-mentioned suction path 51 (FIG. 2) connected to the suction ports 14 to 17 of the sleeve 11, is configured to include a vacuum tank and a vacuum pump. The suction passage 52 includes the above-described collection structure 130 of the first embodiment. The suction passage 52 may include the collection structure 140 of the second embodiment.

[0119] 11, a collection structure 130 is provided midway along a suction path 52 through which gas is sucked from the cavity 23 through the connecting port 28 of the molds 21 and 22. The suction path 52 also includes a cleaning section 151 that extends from the vicinity of the connecting port 28 to the vicinity of the collection section 134 and has a curved shape formed from a plurality of pipes 153 whose flanges are connected to each other by connecting members 160.

[0120] According to the third embodiment, the molten metal residue S and the like mixed with the gas sucked from the cavity 23 through the connecting port 28 into the suction path 52 can be separated from the gas by the collecting structure 130 and collected inside the collecting section 134. Therefore, the outflow of the molten metal residue S and the like to the downstream side of the suction path 52 can be prevented, and the suction efficiency of the suction path 52 can be prevented from being reduced or blocked. In addition, the cleaning section 151 can be easily disassembled into a plurality of pipes 153 by using the connecting member 160, and the molten metal residue S and the like adhering to each pipe 153, the collection section 134, and the like can be cleaned.

[0121] Furthermore, the present invention also includes an embodiment of an air blowing operation as described below. When performing air blowing work on the suction paths 51, 53 communicating with the suction ports 14-17 by switching the vacuum / air blow switching valve 35, for example, all of the suction port selection valves 33 are opened to release air from the pressurized tank 38 toward the suction ports 14-17. In this case, if all of the suction port selection valves 33 are opened simultaneously to blow air, air is supplied preferentially to the unclogged suction paths 51 rather than the clogged suction paths 51, making it difficult to detect the clogging of the suction ports 14-17 and the piping (suction paths 51). Therefore, by opening each suction port selection valve 33 of the first suction port 14, the second suction port 15, the third suction port 16, and the fourth suction port 17 one by one in sequence for a certain period of time, the molten metal residue (molten metal residue S) such as aluminum residue is removed from each pipe (each suction path 51), and the clogging state of each suction port 14-17 and each pipe (each suction path 51) is detected by each pressure gauge 32 during air blowing. This is a necessary measure since there are multiple suction ports (first suction port 14, second suction port 15, third suction port 16, and fourth suction port 17). The other configurations are the same as those of the embodiment shown in FIG. 2.

[0122] The present invention has the above-mentioned configuration and thus provides the following effects. By providing the sleeve with multiple sleeve-side suction ports and installing suction port selection valves on each suction path connected to each suction port, it is possible to select whether or not to use a suction port, resulting in the following effects.

[0123] (1) Reduce defects and stabilize production Since multiple suction ports are provided on the sleeve side, the suction area is increased, making it possible to efficiently achieve a high vacuum state. (2) Measures to prevent clogging of molten metal residue The suction port and suction path that are prone to clogging with molten metal residue such as aluminum waste can be made unnecessary by using the suction port selection valve. In other words, the vacuum suction time of the sleeve-side suction port and sleeve-side suction path that are prone to clogging with molten metal residue such as aluminum waste can be shortened, and clogging with molten metal residue such as aluminum waste can be suppressed.

[0124] (3) Stable production Since multiple suction ports are provided on the sleeve side, vacuum drawing is possible using suction ports other than the unused suction port, which means that production is not interrupted due to clogging caused by molten metal residue such as aluminum waste, and good products can be produced stably. (4) Increased versatility and reduced costs Since there is no need to prepare sleeves for each mold or product, costs are reduced. Therefore, the number of sleeves to be held is reduced, making management easier. Furthermore, the time required to replace sleeves is reduced.

[0125] (5) Reducing defects Since the area of ​​the suction port on the sleeve side can be made larger than that of the suction port on the mold side, it is expected that the effect of preventing preceding molten metal due to vacuum drawing can be expected. By starting the vacuum suction on the sleeve side before the vacuum suction on the mold side, preceding molten metal can be prevented more effectively. This makes it possible to reduce defects such as chipping (loss of part of the product), peeling (peeling where the surface of the product peels off), and stripping for shot blast (phenomenon where the surface of the product turns over). (6) The vacuum suction time for each suction port can be adjusted By providing a suction port selection valve, the vacuum suction time of each suction port can be adjusted according to the position, time, filling rate, etc.

[0126] (7) Stable production by suppressing pressure rise in vacuum tanks Since the sleeve-side suction port can be blocked immediately after (or while) the injection plunger 12 passes through it, the pressure rise in the vacuum tank can be suppressed and the vacuum suction capacity of the sleeve-side suction port located far from the pouring port that the injection plunger 12 has not reached is not reduced. (8) Since the injection plunger 12 can be set to perform vacuum drawing until it is about to complete passing through each sleeve-side suction port, it is possible to perform vacuum drawing through the gap between the injection plunger 12 and the sleeve, thereby preventing outside air from entering the sleeve, which is in a negative pressure state. [Industrial Applicability]

[0127] As described above, according to the present invention, a die casting machine equipped with a suction path for vacuum suction with excellent operational effects can be provided, and the present invention can be utilized and contribute to fields related to the technology of suction paths for vacuum suction within the space formed in the die casting machine by communicating from the internal space of the sleeve to the cavity. [Explanation of symbols]

[0128] 100 Die Casting Machine 1 Injection device 2 Vacuum equipment 4 Movable Platen 5 Fixed Platen 7 Tie Bar 8 Machine Base 10 holes 11 Sleeve 12 Ejection Plunger 13 Pouring spout 14 Suction port (1st suction port) 15 Suction port (2nd suction port) 16 Suction port (3rd suction port) 17 Suction port (4th suction port) 18 Molten metal 19 Plunger rod 21 Fixed mold 22 Movable mold 23 Cavity 24 Runner 25 Gate 27 Chillvent 28 Connection port (suction port) 31 Vacuum Filter 32 Pressure gauge 33 Inlet 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 41 Extrusion plate 42 Ejector pin 43 Raddle 51 Suction Path 51A area 52 Suction Path 55 Piping 56 Piping 130 Collection structure 130F Flow Channel 131 First section (first suction path) 131A Outlet (discharge port) 131B Side wall 131C outer periphery 131D,131E Cylindrical body 131F Flange 132 Second section (second suction path) 132A Inlet (Connection) 133 Section connection part (part of aluminum waste box) 133A Internal wall 133B Upper end 133F Flange (backflow prevention part) 133G Flange 134 Collection section (box for aluminum dust) 134A Piping 134B Lid member 134F Flange 135 Center Ring 135A O-ring 135B Metal ring 136 Clamp 137 Center Ring 138 Clamp 139 Piping 140 Collection structure 141 Ball valve 141A Ball 141B Housing 141C axis 142 Molten metal waste receiver (aluminum waste receiver) 143 Actuator 144 Collection section 144A Outlet 144B Side wall 151 Cleaning Section 153 Piping 160 Connecting parts D4 Extension direction H1,H2 height Ps1,Ps2 position R1 Projection Range S Molten metal waste

Claims

1. A die casting machine having a suction path for vacuum suctioning a space formed by communicating from an internal space of a sleeve having a pouring port to a cavity of a die, a collection structure for collecting molten metal residue mixed in the gas is provided in the middle of a suction path through which gas is sucked through a plurality of suction ports formed in the sleeve in the order from a position close to the pouring port to a position farther from the mold; The collection structure comprises: a collection section connected to the suction path for receiving the molten metal waste; a first section of the suction path extending from an upstream side of the suction path toward the collection section; a section connection section that surrounds the first section from the outside and extends beyond the first section to the collection section; a second section of the suction path connected to the section connection portion at a position where the first section is surrounded by the section connection portion, the first section and the second section are in communication with each other via an inside of the section connection portion, forming a flow path for the gas; The first section extends vertically downward toward the collection section, The height of the outlet of the first section is equal to or less than the height of the inlet of the second section, The gas in the flow path flows out vertically downward from the outlet of the first section, and then flows radially outward from the first section, continuously turning vertically upward from below the outlet inside the section connection portion, and then flows into the inlet of the second section. The die casting machine is characterized by:

2. The section connection portion includes a backflow prevention portion having an opening cross-sectional area smaller than that of the collection portion.

2. The die casting machine according to claim 1.

3. The collection structure comprises: an outlet provided in the collection section and through which the molten metal waste can pass; A valve capable of opening and closing the outlet.

3. The die casting machine according to claim 1 or 2.

4. A die casting machine having a suction path for vacuum suctioning a space formed by communicating from an internal space of a sleeve having a pouring port to a cavity of a die, a first suction path that is connected to a plurality of suction ports formed in the sleeve in the order from a position close to the pouring port to a position farther from the mold, and that is formed so as to extend downward toward an aluminum waste box; the aluminum waste box communicating with the first suction path; A second suction path is formed in the aluminum waste box so as to communicate with the internal space of the aluminum waste box, a height of a discharge port at a lower end of the first suction path is set to be equal to or lower than a height of a connection portion between the aluminum waste box and the second suction path; the first suction path and the second suction path communicate with each other through an inside of the aluminum dust box to form a gas flow path; The gas in the flow path flows out vertically downward from the exhaust port of the first suction path, and then flows radially outward from the first suction path, continuously turning vertically upward from below the exhaust port inside the aluminum waste box, and then flows into the second suction path. A die casting machine having a suction path characterized by:

5. a ball valve provided at a position of the aluminum waste box lower than the height of a connection portion between the aluminum waste box and the second suction path; An aluminum waste receiver installed below the ball valve; 5. The die casting machine according to claim 4, further comprising:

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