DIE CASTING MACHINE.

Abstract

A die-casting machine of one type includes: a base; a fixed die plate attached to the base and supporting a fixed die; a movable die plate provided on the base to be movable in a mold opening and closing direction and supporting a movable die facing the fixed die; an injection device that fills molten metal into a cavity formed by the fixed die and the movable die and applies a first pressure to the molten metal; a first pressurizing device that pressurizes the molten metal filling the cavity in a region other than the product region of the cavity and applies a second pressure to the molten metal; and a control unit that controls the first pressurizing device so that the second pressure is higher than the first pressure.

Description

[1] The present invention relates to a die casting machine that manufactures a molded product by filling a molten metal into a cavity in a mold using an injection device. Background of the invention [2] A die casting machine manufactures a molded product (die-cast product) by filling molten metal into a cavity in a mold held by a mold-holding device using an injection device. It is desired that the die casting machine reduce the casting pressure applied to the molten metal when manufacturing the molded product. Since the casting pressure is reduced, the required capacity for a mold-holding device and an injection device can be reduced, and the manufacturing cost of the die casting machine can be reduced.[3] Patent Document 1 describes a die casting machine that detects a pressure variation in a rising hydraulic pressure in a mold clamping cylinder, controls a filling pressure in a mold cavity by means of a pressurizing pin, and prevents excessive pressure while supplying metal according to a solidification shrinkage rate. However, in the die casting machine of Patent Document 1, it is difficult to significantly reduce the casting pressure. i Qcnnn / zznz / E / γΐΛΐ List of appointments Patent document [4] Patent Document 1: JP 10-24357A Summary of the invention Problem that must be solved by the invention [5] One object to be solved by the invention is to provide a die casting machine capable of reducing a casting pressure applied to a molten metal in the manufacture of a molded product. Means to solve the problem [6] A die casting machine according to one aspect of the invention includes: a base; a fixed die plate attached to the base and supporting a fixed die; a movable die plate provided on the base to be movable in a mold opening and closing direction and supporting a movable die facing the fixed die; an injection device that fills molten metal into a cavity formed by the fixed die and the movable die and applies a first pressure to the molten metal; a first pressurizing device that pressurizes the molten metal filling the cavity in a region other than the product region of the cavity and applies a second pressure to the molten metal; and a control unit that controls the first pressurizing device so that the second pressure is higher than the first pressure. [7] In the die casting machine of the aspect described above, the injection device may include an injection sleeve connected to the cavity, an injection plunger sliding in the injection sleeve and applying the first pressure to the molten metal, an injection actuator moving the injection plunger and a first liquid pressure circuit driving the injection actuator, and the first pressurization device may include a first pressurization plunger applying the second pressure to the molten metal, a first pressurization actuator moving the first pressurization plunger and a second liquid pressure circuit driving the first pressurization actuator. [8] In the die-casting machine of the aspect described above, the first liquid pressure circuit may include a first valve controlling the flow of a first hydraulic fluid flowing in the first liquid pressure circuit and a first accumulator increasing the flow rate of the first hydraulic fluid, and the second liquid pressure circuit may include a second valve controlling the flow of a second hydraulic fluid flowing in the second liquid pressure circuit and a second accumulator increasing the flow rate of the second hydraulic fluid. [9] In the die casting machine of the aspect described above, the first liquid pressure circuit may include a first cylinder absorption back pressure that increases the flow rate of the first hydraulic fluid, and the second liquid pressure circuit may include a second cylinder absorption back pressure that increases the flow rate of the second hydraulic fluid.

[10] In the die casting machine of the appearance described above, the first valve and the second valve may be servo-valves.

[11] In the die casting machine of the aspect described above, the second liquid pressure circuit may include a first liquid pressure sensor provided on a pressurization side of the first pressurization actuator and a second liquid pressure sensor provided on a backpressure side of the first pressurization actuator, and the control unit may control the second pressure based on the measured values ​​of the first liquid pressure sensor and the second liquid pressure sensor.

[12] In the die casting machine of the aspect described above, the second liquid pressure circuit may include a short-circuit flow path to short-circuit a pressurization side and a back-pressure side of the first pressurization actuator and a degassing valve disposed in the short-circuit flow path and the extraction of a gas contained in the second hydraulic liquid.

[13] In the die casting machine of the aspect described above, the second liquid pressure circuit may include a flow rate sensor that measures a flow rate of the second hydraulic fluid and the control unit may control a speed of the first pressurizing plunger based on a measurement value from the flow rate sensor.

[14] In the die casting machine of the above aspect, the first pressurizing actuator may be provided on the fixed die plate and the first pressurizing plunger may be provided on the fixed die.

[15] In the die casting machine of the appearance described above, the second pressure can be 1.1 times or more and 3 times or less than the first pressure.

[16] The die casting machine of the above appearance may further include a second pressurization device that pressurizes the molten metal filling the cavity in a region distinct from the product region of the cavity and applies a third pressure to the molten metal, and the control unit may control the second pressurization device so that the third pressure is higher than the first pressure.

[17] In the die casting machine of the aspect described above, the second pressurizing device may include a second pressurizing plunger to apply the third pressure to the molten metal, a second pressurizing actuator that moves the second pressurizing plunger, and a third liquid pressure circuit that drives the second pressurizing actuator.

[18] In the die casting machine of the above-described appearance, the distance between the second pressurizing device and the injection device may be less than the distance between the first pressurizing device and the injection device, and the control unit may control the first pressurizing device and the second pressurizing device so that the second pressure is higher than the third pressure.

[19] In the die casting machine of the above appearance, the control unit can control the first pressurization device so that the molten metal begins to be pressurized within 10 ms after the molten metal filling into the cavity is complete. i ocnnn / zznz / E / YiAi Effect of the invention

[20] In accordance with the invention, it is possible to provide a die casting machine capable of reducing a casting pressure applied to a molten metal when manufacturing a molded product. Brief description of the drawings

[21] Figure 1 is a schematic view showing a complete configuration of a first-mode die-casting machine; Figure 2 is a schematic view of an injection device and a first pressurization device of the first-mode die casting machine; Figures 3(a) and 3(b) are schematic views that include a fixed array of the first mode die casting machine. Figure 4 is a schematic view of a first liquid pressure circuit of the first mode die casting machine; Figure 5 is a schematic view of a second liquid pressure circuit of the first mode die casting machine; Figure 6 is a block diagram showing a configuration of a signal processing system for the first mode die casting machine; Figure 7 is a graph showing an example of operation of the injection device and the first pressurization device of the die casting machine of the first mode. Figure 8 is a schematic view showing a complete configuration of a second-mode die casting machine. Figure 9 is a schematic view of an injection device, a first pressurization device, and a second pressurization device of the second-mode die casting machine. Figures 10(a) and 10(b) are schematic views that include a fixed array of the second-mode die-casting machine; Figure 11 is a schematic view of a second liquid pressure circuit and a third liquid pressure circuit of the second-mode die casting machine; and Figures 12(a) and 12(b) are schematic views including a fixed array of a third-mode die-casting machine. Method(s) for carrying out the invention

[22] From here on, the embodiments of the invention will be described with reference to the drawings.

[23] Furthermore, in this specification, a description shall be made such that hydraulic pressure is used as an example of liquid pressure. For example, a hydraulic circuit shall be used as an example of a liquid pressure circuit, a hydraulic actuator as an example of a liquid pressure actuator, a hydraulic sensor as an example of a liquid pressure sensor, and a hydraulic device as an example of a liquid pressure device. Instead of hydraulic pressure, for example, water pressure may be used. Furthermore, in this specification, a description shall be made such that hydraulic oil is used as an example of hydraulic fluid. i Qcnnn / zznz / E / γΐΛΐ

[24] First modality A die-casting machine of a first type includes: a base; a fixed die plate attached to the base and supporting a fixed die; a movable die plate provided on the base to be movable in a mold opening and closing direction and supporting a movable die facing the fixed die; an injection device that fills molten metal into a cavity formed by the fixed die and the movable die and applies a first pressure to the molten metal; a first pressurizing device that pressurizes the molten metal filling the cavity in a region other than the product region of the cavity and applies a second pressure to the molten metal; and a control unit that controls the first pressurizing device so that the second pressure is higher than the first pressure. Figure 1 is a schematic view showing the complete configuration of the first-type die casting machine. Figure 1 is a side view that includes a partial cross-sectional view. A first-type die casting machine 100 is a cold-chamber type die casting machine.

[26] The die casting machine 100 includes a mold clamping device 10, an extrusion device 12, an injection device 14, a first pressurization device 16, a mold 18, and a control unit 20.

[27] The die casting machine 100 includes a base 22, a fixed die plate 24, a movable die plate 26, a link housing 28, and a tie bar 30.

[28] The die casting machine 100 is a machine that manufactures a die-cast product by injecting and filling a liquid metal (molten metal) into a mold 18 (cavity Ca in Figure 1) and solidifying the liquid metal in the mold 18. The metal is, for example, aluminum, an aluminum alloy, a zinc alloy, or a magnesium alloy.

[29] Mold 18 includes a fixed die 18a and a movable die 18b. Mold 18 is provided between the mold clamping device 10 and the injection device 14.

[30] Fixed matrix plate 24 is fixed onto base 22. Fixed matrix plate 24 can contain fixed matrix 18a.

[31] The movable die plate 26 is provided on the base 22 to allow movement in the mold opening and closing direction. The mold opening and closing direction means both the mold opening direction and the mold closing direction shown in Figure 1. The movable die plate 26 can hold the movable die 18b facing the fixed die 18a.

[32] The link housing 28 is provided on a base 22. One end of a link mechanism that constitutes the mold clamping device 10 is attached to the link housing 28.

[33] The fixed die plate 24 and the link housing 28 are secured by a tie bar 30. The tie bar 30 supports a mold clamping force while the mold clamping force is applied to the fixed die 18a and 18b of the moving die.

[34] The mold clamping device 10 has a mold opening and closing function 18 and a mold clamping function.

[35] The injection device 14 has the function of injecting molten metal into cavity Ca of mold 18 and pressurizing the molten metal that fills cavity Ca. The injection device 14 has the function of applying initial pressure to the molten metal filled into cavity Ca.

[36] The first pressurization device 16 has the function of pressurizing the molten metal that fills the cavity Ca of the mold 18 in a region distinct from a product region of the cavity Ca. The first pressurization device 16 has the function of applying a second pressure to the molten metal that fills the cavity Ca.

[37] The extrusion device 12 has the function of extruding the die-cast product manufactured from the mold 18.

[38] The control unit 20 includes a control device 32 (control unit), an input device 34, and a display device 36. The control unit 20 has the function of controlling the molding operation of the die casting machine 100 using the mold clamping device 10, the extrusion device 12, the injection device 14, and the first pressurization device 16.

[39] Input device 34 receives an operation of i ocnnn / zznz / E / YiAi input from an operator. The operator can set the molding condition and the like of the die-casting machine 100 using input device 34. Input device 34 is, for example, a touch panel using a liquid crystal display or an organic EL display.

[40] The display device 36 shows, for example, the molding conditions, operating status, and the like of the die casting machine 100 on the screen. The display device 36 is, for example, a liquid crystal display or an organic EL display.

[41] Control device 32 has the function of performing various calculations and issuing a control command to each part of the die casting machine 100. Control device 32 has the function of storing, for example, molding conditions and the like. Control device 32 controls, for example, the operation of injection device 14. Control device 32 controls the operation of the first pressurization device 16, for example, based on the filling state of the molten metal in the mold cavity Ca. 18. Control device 32 controls the first pressurization device so that the second pressure is higher than the first pressure.

[42] Control device 32 is configured, for example, by a combination of hardware and software. Control device 32 includes, for example, a CPU (Unit i Qcnnn / zznz / E / γΐΛΐ Central Processing Unit), a semiconductor memory and a control program stored in the semiconductor memory.

[43] Figure 2 is a schematic view of the injection device and the first pressurization device of the first-mode die casting machine. Figures 3(a) and 3(b) are schematic views including the fixed die of the first-mode die casting machine. Figure 3(a) is a plan view in which the fixed die 18a is seen from the side of the moving die plate 26. Figure 3(b) is a plan view in which the moving die 18b is seen from the side of the fixed die plate 24.

[44] The injection device 14 includes an injection sleeve 40, an injection plunger 42, an injection actuator 44, a first hydraulic circuit 46 (first fluid pressure circuit), and a sensor position 48. The injection sleeve 40 includes a molten metal supply port 40a. The injection plunger 42 includes an injection plunger tip 42a and an injection plunger rod 42b. The injection actuator 44 includes an injection cylinder 44a, an injection piston 44b, a rod-side chamber 44x, and a cap-side chamber 44y.

[45] The injection sleeve 40 is connected to the cavity Ca of the mold 18. The injection sleeve 40 is, for example, a tubular member connected to the fixed die 18a. The injection sleeve 40 has, for example, a cylindrical shape.

[46] The injection plunger 42 slides in the injection sleeve 40. The tip of the injection plunger 42a, fixed to the tip of the injection plunger stem 42b, slides back and forth in the injection sleeve 40. When the tip of the injection plunger 42a slides forward in the injection sleeve 40, the molten metal in the injection sleeve 40 is extruded into the mold 18.

[47] The injection plunger 42 applies the first pressure to the molten metal by pressurizing the molten metal after the molten metal is introduced into the Ca cavity of the mold 18.

[48] ​​Molten metal supply port 40a is provided, for example, in the upper portion of injection sleeve 40. For example, molten metal is supplied from molten metal supply port 40a in injection sleeve 40 by means of a ladle (not shown).

[49] The injection actuator 44 is, for example, a hydraulic actuator. The injection actuator 44 has the function of moving the injection plunger 42. The injection plunger 42 moves when the injection piston 44b in the injection cylinder 44a pushes and pulls the rod of the injection plunger 42b.

[50] The first hydraulic circuit 46 has the function i Qcnnn / zznz / E / YiAi of driving the injection actuator 44. The first hydraulic circuit 46 is an example of the first fluid pressure circuit. The first hydraulic circuit 46 is connected to the rod-side chamber 44x and the cap-side chamber 44y of the injection cylinder 44a. The first hydraulic circuit 46 is connected to the pressurization side and the back-pressure side of the injection cylinder 44a by means of the tubes.

[51] Position sensor 48 has a function of detecting the position of the injection plunger 42. Position sensor 48 is, for example, an optical or magnetic linear encoder. By differentiating the position of the injection plunger 42 detected by position sensor 48, it is possible to determine the speed of the injection plunger 42.

[52] The first pressurization device 16 includes a first pressurization plunger 52, a first pressurization actuator 54, a second hydraulic circuit 56 (second fluid pressure circuit), and a first load sensor 58. The first pressurization plunger 52 includes a first pressurization plunger tip 52a and a first pressurization plunger rod 52b. The first pressurization actuator 54 includes a first pressurization cylinder 54a, a first pressurization piston 54b, a first rod-side chamber 54x, and a first cap-side chamber 54y.

[53] The cavity Ca formed by the fixed die 18a and the moving die 18b includes a product region Cax (a region with diagonal stripes in Figure 2) and a non-product region Cay. The molten metal solidified in the product region Cax is used as die casting. For example, the molten metal solidified in the non-product region Cay is removed in a trimming process and is not used as die casting. Non-product regions Cay are, for example, slides, overflows, air outlets, and the like.

[54] For example, a first guide region 18x is provided in the non-product region Cay of the fixed die 18a. The first guide region 18x is, for example, a cylindrical recess provided in the fixed die 18a. The first guide region 18x is arranged on the opposite side of the Cax product region with respect to the injection sleeve 40.The Cax product region is interposed between the first guide region 18x and the injection sleeve 40.

[55] The first pressurization plunger 52 slides in the first guide region 18x. The first tip of the pressurization plunger 52a, attached to the tip of the first pressurization plunger rod 52b, slides back and forth in the first guide region 18x.

[56] The first pressurizing plunger 52 applies the second pressure to the molten metal by pressurizing the molten metal after the molten metal is introduced into the Ca cavity of the mold 18. When the first tip of the pressurizing plunger 52a slides forward in the first guide region 18x, the molten metal is pressurized.

[57] The first pressurization actuator 54 is, for example, a hydraulic actuator. The first pressurization actuator 54 has the function of moving the first pressurization plunger 52. The first pressurization plunger 52 is moved when the first pressurization piston 54b in the first pressurization cylinder 54a pushes and pulls the first pressurization plunger rod 52b.

[58] For example, as shown in Figure 1, the first pressurization actuator 54 of the first pressurization device 16 is provided on the fixed matrix plate 24.

[59] The second hydraulic circuit 56 has the function of driving the first pressurization actuator 54. The second hydraulic circuit 56 is an example of the second fluid pressure circuit. The second hydraulic circuit 56 is connected to the first chamber on the rod side 54x and to the first chamber on the cap side 54y of the first pressurization cylinder 54a. The second hydraulic circuit 56 is connected to the pressurization side and the backpressure side of the first pressurization cylinder 54a by means of the pipes.

[60] The first load sensor 58 has a function of measuring the load applied to the first rod of the pressurizing plunger 52b. For example, it is possible to detect the completion of the filling of the molten metal in the cavity Ca of the mold 18 by determining the contraction state of the first rod of the pressurizing plunger 52b using the first load sensor 58.

[61] For example, a molten metal pressure sensor 60 is provided in mold 18. The molten metal pressure sensor 60 can detect the completion of molten metal filling in cavity Ca of mold 18 by directly measuring the pressure of the molten metal filling cavity Ca.

[62] The operations of the injection device 14 and the first pressurization device 16 are controlled by the control device 32 (control unit). The operations of the first hydraulic circuit 46 and the second hydraulic circuit 56 are controlled by the control device 32 (control unit). The first hydraulic circuit 46 and the second hydraulic circuit 56 are connected to the control device 32 in a wired or wireless state.

[63] Figure 4 is a schematic view of the first hydraulic circuit of the first-mode die casting machine. The first hydraulic circuit 46 drives the injection actuator 44.

[64] The first hydraulic circuit 46 includes a first valve 70, a first accumulator 71, a first backpressure absorption cylinder 72, a pump 73, a tank 74, a pressurization-side hydraulic sensor 75, a backpressure-side hydraulic sensor 76, and tubes 78a, 78b, 78c, 78d, 78e and 78f.

[65] The first valve 70 controls the flow of the first hydraulic oil (first hydraulic fluid) flowing in the first hydraulic circuit 46. The first valve 70 controls the supply and stopping of the first hydraulic oil from the pump 73 to the injection actuator 44. The first valve 70 controls the discharge and stopping of the first hydraulic oil from the injection actuator 44 to the tank 74.

[66] The first valve 70 is, for example, a servo valve. A servo valve is an electromagnetic direction-switching valve that changes the flow path by means of an electromagnetic force. The servo valve has a high response efficiency to the input signal.

[67] The first accumulator 71 is provided between the pump 73 and the first valve 70. The first accumulator 71 stores energy using an enclosed high-pressure gas and momentarily discharges the energy to increase the flow rate of the first hydraulic oil. Because the first accumulator 71 is provided, it is possible to generate high pressure using the injection actuator 44 by operating the injection actuator 44 at high speed.

[68] The first backpressure absorption cylinder 72 is provided between the first valve 70 and the tank 74. Since the first backpressure absorption cylinder is provided 72, it is possible to quickly reduce the pressure on the backpressure side of the injection drive device 44, i.e., the pressure in the chamber on the rod side 44x of the injection cylinder 44a. Therefore, it is possible to operate the injection actuator 44 at high speed.

[69] The pressurization-side hydraulic sensor 75 is provided between the first valve 70 and the injection actuator 44. The pressurization-side hydraulic sensor 75 is provided in the tube 78c. The pressurization-side hydraulic sensor 75 can measure the pressure on the pressurization side of the injection actuator 44, i.e., the pressure in the chamber on the cover side 44y.

[70] The backpressure-side hydraulic sensor 76 is provided between the first valve 70 and the injection actuator 44. The backpressure-side hydraulic sensor 76 is provided in the tube 78d. The backpressure-side hydraulic sensor 76 can measure the hydraulic pressure on the backpressure side of the injection actuator 44, i.e., the hydraulic pressure of the stem-side chamber 44x.

[71] Figure 5 is a schematic view of the second hydraulic circuit of the first-mode die casting machine. The second hydraulic circuit 56 drives the first pressurization actuator 54.

[72] The second hydraulic circuit 56 includes a second valve 80, a second accumulator 81, a second backpressure absorbent cylinder 82, a pump 83, a tank 84, a pressurization-side hydraulic sensor 85 (first fluid pressure sensor), a backpressure-side hydraulic sensor 86 (second fluid pressure sensor), a flow rate sensor 87, tubes 88a, 88b, 88c, 88d, 88e, 88f and 88g, and a degassing valve 89.

[73] The second valve 80 controls the flow of the second hydraulic oil (second hydraulic fluid) flowing in the second hydraulic circuit 56. The second valve 80 controls the supply and stopping of the second hydraulic oil from the pump 83 to the first pressurization actuator 54. The second valve 80 controls the discharge and stopping of the second hydraulic oil from the first pressurization actuator 54 to the tank 84.

[74] The second valve 80 is, for example, a servo valve. A servo valve is an electromagnetic direction-switching valve that changes the flow path by means of an electromagnetic force. The servo valve has a high response efficiency to the input signal.

[75] The second accumulator 81 is provided between the pump 83 and the second valve 80. The second accumulator 81 stores energy using an enclosed high-pressure gas and momentarily discharges the energy to increase the flow rate of the second hydraulic oil. Because the second accumulator 81 is provided, it is possible to generate high pressure using the first pressurization actuator 54 by operating it at high speed.

[76] The second backpressure absorbent cylinder 82 is provided between the second valve 80 and the tank 84. Because the second backpressure absorbent cylinder 82 is provided, it is possible to rapidly reduce the pressure on the backpressure side of the first pressurizing actuator 54, i.e., the pressure in the chamber on the rod side 54x of the first pressurizing cylinder 54a. Therefore, it is possible to operate the first pressurizing actuator 54 at high speed.

[77] The pressurizing-side hydraulic sensor 85 is provided between the second valve 80 and the first pressurizing actuator 54. The pressurizing-side hydraulic sensor 85 is an example of the first fluid pressure sensor. The pressurizing-side hydraulic sensor 85 is provided in the tube 88c.The hydraulic sensor on the pressurization side 85 can measure the hydraulic pressure on the pressurization side of the first pressurization actuator 54, i.e., the hydraulic pressure of the chamber on the lid side 54y.

[78] The backpressure-side hydraulic sensor 86 is provided between the second valve 80 and the first pressurization actuator 54. The backpressure-side hydraulic sensor 86 is an example of the second fluid pressure sensor. The backpressure-side hydraulic sensor 86 is provided in tube 88d. The backpressure-side hydraulic sensor 86 can measure the hydraulic pressure on the backpressure side of the first pressurization actuator 54, i.e., the hydraulic pressure in the stem-side chamber 54x.

[79] The flow velocity sensor 87 measures the flow velocity of the second hydraulic oil flowing in the tube 88d. By measuring the flow velocity of the second hydraulic oil, it is possible to control the speed of the first pressurizing piston 54b, i.e., the speed of the first pressurizing piston rod 52b and the first pressurizing piston tip 52a, i.e., the speed of the first pressurizing piston 52.

[80] Tube 88g is a short-circuit flow path that short-circuits the pressurization side and the backpressure side of the first pressurization actuator 54. Tube 88g short-circuits tube 88c and tube 88d by opening the degassing valve 89 to divert the first pressurization actuator 54.

[81] Since tube 88c and tube 88d are short-circuited as they pass through the first pressurization actuator 54, it is possible to extract the gas (air) accumulated in the second hydraulic oil. Because the gas (air) accumulated in the second hydraulic oil is extracted, the operation of the first pressurization actuator 54 and the second hydraulic circuit 56 is stable.

[82] Figure 6 is a block diagram showing a configuration of a signal processing system for the first mode die casting machine.

[83] For example, as shown in Figure 6, the control device 32 includes a molding conditions setting unit 32a, an injection control unit 32b, and a pressurization control unit 32c.

[84] The molding condition adjustment unit 32a has a function of adjusting various molding conditions of the die casting machine 100 based on the signal from the input device 34. The molding condition adjustment unit 32a, for example, the injection speed of the injection plunger 42 of the injection device 14, the start time of operation of the first pressurization device 16, and similar.

[85] The injection control unit 32b controls the operation of the injection device 14. Specifically, for example, the operation of the injection device 14 is controlled by the transmission of a command signal to the first valve 70 provided in the first hydraulic circuit 46 and the control of the opening and closing of the first valve 70.

[86] The injection control unit 32b controls the opening and closing of the first valve 70 to control the speed of the injection plunger 42, for example, based on the speed of the injection plunger 42 monitored by the position sensor 48. In addition, the opening and closing of the first valve 70 are controlled to control the first pressure applied to the molten metal by the injection plunger 42, for example, based on the measured values ​​of the hydraulic pressure measured by the pressurization-side hydraulic sensor 75 and the backpressure-side hydraulic sensor 76.

[87] The pressurization control unit 32c controls the operation of the first pressurization device 16. Specifically, for example, the operation of the first pressurization device 16 is controlled by the transmission of a command signal to the second valve 80 provided in the second hydraulic circuit 56 and the control of the opening and closing of the second valve 80.

[88] The pressurization control unit 32c controls the first pressurization device 16 such that the pressurization of the molten metal by the first pressurization device 16 begins after the molten metal filling of cavity Ca is complete. The pressurization control unit 32c controls the first pressurization device 16 such that the operation of the first pressurization device 16 begins after the molten metal filling of cavity Ca is complete.

[89] The pressurization control unit 32c controls the opening and closing of the second valve 80 to control the start of operation of the first pressurization plunger 52, for example, based on the speed of the injection plunger 42 monitored by the position sensor 48. For example, the operation of the first pressurization plunger 52 is controlled to start immediately after the injection plunger 42 stops. The moment the injection plunger 42 stops is determined to be the moment the filling of the molten metal in cavity Ca is complete.

[90] The pressurization control unit 32c controls the opening and closing of the second valve 80 to control the start of operation of the first pressurization plunger 52, for example, based on the measurement value of the molten metal pressure sensor 60.For example, the operation of the first pressurization plunger 52 is controlled to begin immediately after the pressure applied to the molten metal reaches a predetermined pressure. The moment when the molten metal pressure reaches the predetermined pressure is determined to be the moment when the filling of the molten metal in cavity Ca is complete.

[91] The pressurization control unit 32c controls the opening and closing of the second valve 80 to control the start of operation of the first pressurization plunger i Qcnnn / zznz / E / γΐΛΐ 52, for example, based on the measurement value of the first load sensor 58. For example, the operation of the first pressurizing plunger 52 is controlled to begin immediately after the load of the first pressurizing plunger rod 52b reaches a predetermined value. The moment when the load of the first pressurizing plunger rod 52b reaches the predetermined value is determined to be the moment when the filling of the molten metal in cavity Ca is complete.

[92] The pressurization control unit 32c controls the opening and closing of the second valve 80 to control the second pressure applied to the molten metal by the first pressurization plunger 52, for example, based on the hydraulic pressure measurement values ​​measured by the pressurization-side hydraulic sensor 85 and the backpressure-side hydraulic sensor 86. The pressurization control unit 32c controls the opening and closing of the second valve 80 so that the second pressure is 1.1 times or more and 3 times or less than the first pressure.

[93] The pressurization control unit 32c controls the opening and closing of the second valve 80 to control the speed of the first pressurization plunger 52, for example, based on the measured value of the flow rate sensor 87.

[94] An example of the operation of the die casting machine 100 will now be described. In particular, the operations of the injection device 14 and the first pressurization device 16 of the die casting machine 100 will be described. The description of operations other than the operations of the injection device 14 and the first pressurization device 16 of the die casting machine 100, for example, the operations of the mold clamping device 10 and the extrusion device 12, will be omitted.

[95] Figure 7 is a graph showing an example of the operations of the injection device and the first pressurization device of the first-mode die casting machine. The horizontal axis is time. As time passes, the plotted points are located on the right side of the paper. The vertical axis on the left side of the paper indicates the injection speed, i.e., the speed of the injection plunger 42. In addition, the vertical axis on the right side of the paper indicates the pressure applied to the molten metal in the cavity Ca.

[96] The solid line Cv in Figure 7 is the injection plunger speed 42 and the solid line Cp in Figure 7 is the pressure applied to the molten metal. The midpoint line Cx in Figure 7 is a critical flash blow curve. When the pressure applied to the molten metal exceeds the critical flash blow curve, the pressure applied to the molten metal may exceed the mold holding force, causing flash.

[97] At time tO, the operation of the injection plunger 42 of the injection device 14 is initiated according to the command from the injection control unit 32b of the control device 32. Before the start of the operation of the injection plunger 42, molten metal is supplied from the molten metal supply port 40a to the injection sleeve 40.

[98] The speed of injection plunger 42 is low from time t0 to time ti. The speed of injection plunger 42 is less than, for example, 1 m / s.

[99] The speed of the injection plunger 42 increases from time ti. The speed of the injection plunger 42 is, for example, 1 m / s or more. At time ti, the tip of the injection plunger 42a is in a state of blocking the molten metal supply port 40a.

[100] At time t2, the injection plunger 42 stops. At time t2, the filling of the molten metal in the cavity Ca formed by the fixed die 18a and the moving die 18b is completed.

[101] Pressurization of the molten metal by injection plunger 42 begins before injection plunger 42 stops. High pressure is applied to the molten metal after filling is complete to reduce cavities created by trapped air during filling and cavities created when the molten metal solidifies after filling is complete.

[102] The pressure applied to the molten metal by the injection plunger 42 is the first pressure P1. The first pressure P1 can be calculated from the force applied to the injection piston 44b and the area ratio between the injection piston 44b and the tip of the injection plunger 42a.

[103] When the injection plunger 42 stops, a pressure surge can be generated that momentarily exceeds the first pressure P1. When the overpressure exceeds the critical flash blow curve, the pressure applied to the molten metal can exceed the mold's clamping force to cause flash.

[104] For example, once the molten metal has been filled into cavity Ca, the operation of the first pressurizing plunger 52 of the first pressurizing device 16 is initiated by a command from the pressurization control unit 32c of the control device 32. For example, the operation of the first pressurizing plunger 52 is initiated when the injection plunger 42 stops. For example, the operation of the first pressurizing plunger 52 is initiated when the pressure applied to the molten metal reaches a predetermined pressure. Additionally, for example, the operation of the first pressurizing plunger 52 is initiated when the load on the first pressurizing plunger rod 52b reaches a predetermined value.

[105] The pressurization of the molten metal is initiated by the first pressurization plunger 52, for example, within 10 ms after the placement of the molten metal in the cavity is completed Ca.

[106] The pressure applied to the molten metal by the first pressurizing plunger 52 is the second pressure. The second pressure P2 can be calculated from the force applied to the first pressurizing piston 54b and the area ratio between the first pressurizing piston 54b and the first tip of the pressurizing plunger 52a.

[107] The second pressure is greater than the first pressure. The second pressure is, for example, 1.1 times or more and 3 times or less than the first pressure. The second pressure is, for example, 1.2 times or more and 1.5 times or less than the first pressure.

[108] Since the first pressurizing plunger 52 applies the second pressure to the first pressure applied by the injection plunger 42, the pressure applied to the molten metal finally increases. The pressure finally applied to the molten metal is the pouring pressure.

[109] The function and effect of the first-modity die-casting machine 100 will now be described.

[110] For example, in the die-casting machine that does not include the first pressurization device, high pressure needs to be applied to the molten metal after the injection plunger stops in order to reduce cavities created by trapped air during the filling of the molten metal and cavities created when the molten metal solidifies after filling is complete. That is, it is necessary to increase the casting pressure.

[111] After the molten metal is filled, it solidifies over time. Therefore, the pressure propagation resulting from the pressurization of the molten metal by the injection plunger is limited. Thus, in particular, to achieve a desired molten metal pressure in the region away from the injection plunger, it is necessary to apply high pressure to the molten metal using the injection plunger.

[112] However, in order to increase the casting pressure, the required capacity of the mold clamping device or the injection device increases. Specifically, for example, a hydraulic device or linkage mechanism that generates high pressure is required to increase the clamping force of the mold clamping device. Furthermore, for example, to apply high pressure using the injection device, it is necessary to add a pressure-boosting mechanism, such as a pressure-boosting piston. Therefore, the problem arises that the manufacturing cost of the die casting machine increases.

[113] In addition, when high pressure is applied to the molten metal by the injection plunger, the discharge pressure may exceed the critical flash blow curve, and the pressure applied to the molten metal may exceed the clamping force of the mold due to flash.

[114] The die casting machine 100 of the first modality includes the first pressurization device 16 in addition to the injection device 14. The first pressurization device 16 pressurizes the molten metal in a region other than the product region of the cavity Ca before the solidification of the molten metal filled in the cavity Ca of the mold 18 progresses.

[115] Since both the injection device 14 and the first pressurization device 16 apply pressure to the molten metal before solidification progresses, the pressure is more likely to be transmitted uniformly throughout the molten metal. Therefore, segregation, coarser structure, and cavities in the die-cast product can be suppressed after solidification. Consequently, the casting pressure can be reduced. Therefore, it is not necessary to increase the capacity of the mold clamping device or the injection device, and the manufacturing cost of the die casting machine can be reduced.

[116] Furthermore, the control device 32 controls the first pressurization device 16 so that the second pressure, greater than the first pressure applied to the molten metal by the injection device 14, is applied to the molten metal by the first pressurization device 16. Therefore, sufficient pressure is applied to the molten metal even when the molten metal solidifies to a certain extent.

[117] Furthermore, since the second pressure is higher than the first pressure, it is possible to suppress the formation of burrs. Because the first pressure is low, the overpressure when the injection plunger 42 stops is reduced, and the formation of burrs is suppressed.

[118] From the standpoint of applying sufficient pressure to the molten metal, the second pressure is preferably 1.1 times or more, and very preferably 1.2 times or more, the first pressure. Furthermore, from the standpoint of suppressing the formation of burrs, the second pressure is preferably 3 times or less, and very preferably 1.5 times or less, than the first pressure.

[119] The die casting machine 100 of the first mode pressurizes the non-product region Cay of the mold cavity Ca 18. Therefore, the die-cast product is not affected by segregation in the molten metal caused by pressurization. Therefore, it is possible to manufacture a high-quality die-cast product.

[120] Furthermore, the die casting machine 100 of the first modality reduces the mechanical stress applied to mold 18 by decreasing the casting pressure. Therefore, the service life of mold 18 is extended.

[121] In order to pressurize the molten metal before the solidification of the molten metal progresses, the control device 32 preferably controls the first pressurization device 16 so that the pressurization of the molten metal by the first pressurization device 16 starts within 10 ms after the filling of the molten metal in the cavity C of the mold 18 is completed.

[122] For example, the time elapsed from time t2 to time t3 shown in Figure 7 is preferably 10 ms or less.

[123] For example, the control device 32 preferably controls the first pressurization device 16 such that the operation of the first pressurization plunger 52 begins within 10 ms after the injection plunger 42 stops. Furthermore, for example, the control device 32 preferably controls the first pressurization device 16 such that the operation of the first pressurization plunger 52 begins within 10 ms after the pressure applied to the molten metal reaches a predetermined pressure. Furthermore, for example, the first pressurization device 16 is preferably controlled such that the operation of the first pressurization plunger 52 begins within 10 ms after the load on the first rod 52b of the pressurization plunger reaches a predetermined value.

[124] From the standpoint of applying sufficient pressure to the molten metal, the first guide region 18x of the fixed die 18a is preferably provided on the opposite side of the injection sleeve 40, with the product region Cax interposed between them. That is, the first pressurization device 16 is preferably provided to pressurize the product-free region Cay on the opposite side of the product-free region Cay pressurized by the injection device 14, with the product region Cax interposed between them.

[125] In order to pressurize the molten metal before solidification and to allow the molten metal to progress, the first pressurization device 16 preferably has high responsiveness and operates at a high speed similarly to the injection device 14.

[126] From the point of view that the first pressurization device 16 has high responsiveness, the second valve 80 is preferably a servo valve that has high responsiveness.

[127] From the point of view of the operation of the first pressurization device 16 at a high speed, the second hydraulic circuit 56 preferably includes the second accumulator 81 and the second backpressure absorbent cylinder 82. From the second accumulator 81 and second backpressure absorbent cylinder 82, it is possible to increase the flow rate of the second hydraulic oil and operate the first pressurization device 16 at high speed.

[128] From the point of view of controlling with high precision the second pressure applied to the molten metal by the first pressurization device 16, the control device 32 preferably controls the opening and closing of the second valve 80 to control the second pressure applied to the molten metal by the first pressurization piston 52 based on the hydraulic pressure measurement values ​​measured by the hydraulic sensor 85 on the pressurization side and the hydraulic sensor 86 on the back pressure side.

[129] The second hydraulic circuit 56 preferably includes the tube 88g corresponding to the short-circuit flow path by short-circuiting the pressurization side and the back pressure side of the first pressurization actuator 54 and the degassing valve 89. The operation of the first pressurization actuator 54 and the second hydraulic circuit 56 is stable.

[130] The second hydraulic circuit 56 preferably includes the flow rate sensor 87 and the pressurization control unit 32c of the control device 32 preferably controls the opening and closing of the second valve 80 to control the speed of the first pressurization plunger 52 based on the measurement value of the flow rate sensor 87. The speed of the first pressurization plunger 52 is stable.

[131] The first pressurization actuator 54 of the first pressurization device 16 is preferably provided on the fixed die plate 24. In addition, the first pressurization plunger 52 is preferably provided on the fixed die 18a. Since the first pressurization actuator 54 is not provided on the fixed die 18a, it is easy to design and manufacture the fixed die 18a.

[132] As described above, in accordance with the first modality, since the first pressurization device 16 is provided, it is possible to realize the die casting machine capable of reducing the casting pressure.

[133] Second modality A second-type die casting machine differs from a first-type die casting machine in that it also provides a second pressurization device to pressurize molten metal filling a cavity in a region other than the product region of the cavity. Some descriptions of the contents that overlap with the first type may be omitted below.

[134] Figure 8 is a schematic view showing a complete configuration of the second-mode die-casting machine. Figure 8 is a side view that includes a partial cross-sectional view. A second-mode 200 die-casting machine is a cold-chamber type die-casting machine.

[135] The die casting machine 200 includes a mold clamping device 10, an extrusion device 12, an injection device 14, a first pressurization device 16, a second pressurization device 17, a mold 18, and a control unit 20.

[136] The die casting machine 200 includes a base 22, a fixed die plate 24, a movable die plate 26, a link housing 28, and a tie bar 30.

[137] The first pressurization device 16 and the second pressurization device 17 have pressurization functions of a molten metal that fills a Ca cavity of the mold 18 in a region distinct from the product region of the Ca cavity.

[138] Figure 9 is a schematic view of an injection device, a first pressurization device, and a second pressurization device of the second-mode die casting machine. The operation and function of the first pressurization device 16 and the operation and function of the second pressurization device 17 are basically the same, except that the pressurization position is different.

[139] Figures 10(a) and 10(b) are schematic views including a fixed die of the second-type die casting machine. Figure 10(a) is a plan view showing a fixed die 18a from the side of the moving die plate 26. Figure 10(b) is a plan view showing a moving die 18b from the side of the fixed die plate 24.

[140] The injection device 14 includes an injection sleeve 40, an injection plunger 42, an injection actuator 44, a hydraulic first circuit 46, and a sensor position 48. The injection sleeve 40 includes a molten metal supply port 40a. The injection plunger 42 includes an injection plunger tip 42a and an injection plunger rod 42b. The injection actuator 44 includes an injection cylinder 44a, an injection piston 44b, a rod-side chamber 44x, and a cap-side chamber 44y.

[141] The first pressurization device 16 includes a first pressurization plunger 52, a first pressurization actuator 54, a second hydraulic circuit 56, and a first load sensor 58. The first pressurization plunger 52 includes a first pressurization plunger tip 52a and a first pressurization plunger rod 52b. The first pressurization actuator 54 includes a first pressurization cylinder 54a, a first pressurization piston 54b, a first rod-side chamber 54x, and a first cap-side chamber 54y.

[142] The second pressurization device 17 includes a second pressurization plunger 62, a second pressurization actuator 64, a third hydraulic circuit 66 (third fluid pressure circuit), and a second load sensor 68. The second pressurization plunger 62 includes a second pressurization plunger tip 62a and a second pressurization plunger rod 62b. The second pressurization actuator 64 includes a second pressurization cylinder 64a, a second pressurization piston 64b, a second rod-side chamber 64x, and a cap-side chamber 64y.

[143] For example, a first guide region 18x is provided in a Cay-free region of the fixed die 18a. The first guide region 18x is, for example, a cylindrical recess provided in the fixed die 18a. Furthermore, for example, a second guide region 18y is provided in another Cay-free region of the fixed die 18a. The second guide region 18y is, for example, a cylindrical recess provided in the fixed die 18a.

[144] For example, the second guide region 18y is provided on the opposite side from the first guide region 18x, with the Cax-product region interposed between them. The Cax-product region is interposed between the first guide region 18x and the second guide region 18y. For example, the second pressurization device 17 is provided to pressurize the product-free region Cay on the opposite side from the product-free region Cay pressurized by the first pressurization device 16 with the product region Cax interposed between them.

[145] For example, as shown in Figure 8, the second pressurization actuator 64 of the second pressurization device 17 is provided on the fixed matrix plate 24.

[146] The pressure applied to the molten metal by the second pressurizing device 17 is the third pressure. The pressure applied to the molten metal by the second pressurizing plunger 62 is the third pressure. The third pressure is greater than the first pressure. The third pressure is, for example, 1.1 times or more and 1.5 times or less than the first pressure.

[147] Figure 11 is a schematic view of the second hydraulic circuit and the third hydraulic circuit of the second-mode die-casting machine. The second hydraulic circuit 56 drives the first pressurizing actuator 54. The third hydraulic circuit 66 drives the second pressurizing actuator 64. The third hydraulic circuit 66 is an example of the third fluid pressure circuit. The operation and function of the second hydraulic circuit and the operation and function of the third hydraulic circuit 66 are essentially the same.

[148] The second hydraulic circuit 56 includes a second valve 80, a second accumulator 81, a second backpressure absorbent cylinder 82, a pump 83, a tank 84, a pressurization-side hydraulic sensor 85 (first fluid pressure sensor), a backpressure-side hydraulic sensor 86 (second fluid pressure sensor), a flow rate sensor 87, tubes 88a, 88b, 88c, 88d, 88e, 88f and 88g, and a degassing valve 89.

[149] The third hydraulic circuit 66 includes a third valve 90, a second accumulator 81, a second backpressure absorbent cylinder 82, a pump 83, a tank 84, a pressurization-side hydraulic sensor 95, a backpressure-side hydraulic sensor 96, a flow rate sensor 97, tubes 98e, 98f and 98g, and a degassing valve 99.

[150] The second accumulator 81, the second backpressure absorber cylinder 82, the pump 83, and the tank 84 are shared between the second hydraulic circuit 56 and the third hydraulic circuit 66.

[151] The die casting machine 200 of the second modality includes the first pressurization device 16 and the second pressurization device 17 in addition to the injection device 14. The first pressurization device 16 and the second pressurization device 17 pressurize molten metal in a region other than the product region of the cavity Ca before the solidification of the molten metal filled in the cavity Ca of the mold 18 progresses.

[152] The injection device 14, the first pressurization device 16, and the second pressurization device 17 apply pressure to the molten metal before solidification progresses in three positions. Therefore, since the pressure is more likely to be transmitted uniformly to the molten metal compared to the die casting machine 100 of the first modality, the cavities can be effectively reduced. Therefore, the casting pressure can be reduced even further. Consequently, it is not necessary to further increase the capacity of the mold clamping device or the injection device, and it is possible to reduce the manufacturing cost of the die casting machine.

[153] As described above, in accordance with the second modality, since the first pressurization device 16 and the second pressurization device 17 are provided, it is possible to realize that the die casting machine is able to further decrease the casting pressure. i Qcnnn / zznz / E / γΐΛΐ

[154] Third modality A third-mode die-casting machine differs from first-mode and second-mode die-casting machines in that it also provides a third pressurizing device to pressurize molten metal filling a cavity in a region other than the product region of the cavity. Some descriptions for content that overlaps with the first and second modes may be omitted hereafter.

[155] Figures 12(a) and 12(b) are schematic views including a fixed die of the third-mode die-casting machine. Figure 12(a) is a plan view showing a fixed die 18a from the side of a moving die plate 26. Figure 12(b) is a plan view showing a moving die 18b from the side of a fixed die plate 24.

[156] An injection device 14 includes an injection sleeve 40, an injection plunger 42, an injection actuator 44, a hydraulic first circuit 46, and a position sensor 48. The injection sleeve 40 includes a molten metal supply port 40a. The injection plunger 42 includes an injection plunger tip 42a and an injection plunger rod 42b. The injection actuator 44 includes an injection cylinder 44a, an injection piston 44b, a rod-side chamber 44x, and a cap-side chamber 44y.

[157] Similar to the first and second embodiments, a first pressurization device 16 includes a first pressurization plunger 52, a first pressurization actuator 54, a second hydraulic circuit 56, and a first load sensor 58. The first pressurization plunger 52 includes a first pressurization plunger tip 52a and a first pressurization plunger rod 52b. The first pressurization actuator 54 includes a first pressurization cylinder 54a, a first pressurization piston 54b, a first rod-side chamber 54x, and a first cap-side chamber 54y.

[158] Similar to the second embodiment, the second pressurization device 17 includes a second pressurization plunger 62, a second pressurization actuator 64, a third hydraulic circuit 66 (third fluid pressure circuit), and a second load sensor 68. The second pressurization plunger 62 includes a second pressurization plunger tip 62a and a second pressurization plunger 62b. The second pressurization actuator 64 includes a second pressurization cylinder 64a, a second pressurization piston 64b, a second rod-side chamber 64x, and a plug-side chamber 64y.

[159] The third pressurization device 19 has the same configuration as the first pressurization device 16 and the second pressurization device 17. The third pressurization device 19 includes a third pressurization plunger, a third pressurization actuator 94, a third hydraulic circuit (not shown), and a third load sensor (not shown). The third pressurization plunger includes a third pressurization plunger tip 92a and a third pressurization plunger rod (not shown). The third pressurization actuator 94 includes a third pressurization cylinder a, a third pressurization piston, a third rod-side chamber, and a third cap-side chamber (not shown).

[160] For example, a first guide region 18x is provided in a non-product Cay region of the fixed die 18a. The first guide region 18x is, for example, a cylindrical recess provided in the fixed die 18a. Furthermore, a second guide region 18y is provided in another non-product Cay region of the fixed die 18a. The second guide region 18y is, for example, a cylindrical recess provided in the fixed die 18a. Furthermore, a third guide region 18z is provided in another non-product Cay region of the fixed die 18a. The third guide region 18z is, for example, a cylindrical recess provided in the fixed die 18a.

[161] The second guide zone 18y and the third guide region 18z are provided on the left and right sides of the Cax product region, with the Cax product region interposed between them. The Cax product region is interposed between the second guide region 18y and the third guide region 18z.

[162] The first pressurization actuator 54 of the first pressurization device 16, the second pressurization actuator 64 of the second pressurization device 17, and the third pressurization actuator 94 of the third pressurization device are provided, for example, on the fixed die plate 24.

[163] The pressure applied to the molten metal by the second pressurizing device 17 is the third pressure. The pressure applied to the molten metal by the second pressurizing piston 62 is the third pressure. The third pressure is greater than the first. The third pressure is, for example, 1.1 times or more and 3 times or less than the first pressure. The third pressure is less than, for example, the second pressure.

[164] The pressure applied to the molten metal by the third pressurizing device 19 is the fourth pressure. The pressure applied to the molten metal by the third pressurizing piston is the fourth pressure. The fourth pressure is greater than the first. The fourth pressure is, for example, 1.1 times or more and 3 times or less than the first pressure. The fourth pressure is less than, for example, the second pressure.

[165] The distance between the second region of figure 18y and the injection sleeve 40 is smaller than the distance between the first guide region 18x and the injection sleeve 40. The distance between the third guide region 18z and the injection sleeve 40 is less than the distance between the first guide region 18x and the injection sleeve 40.

[166] The distance between the second tip of the pressurization plunger 62a and the tip of the injection plunger 42a is less than the distance between the first tip of the pressurization plunger 52a and the tip of the injection plunger 42a. The distance between the third tip of the pressurization plunger 92a and the tip of the injection plunger 42a is less than the distance between the first tip of the pressurization plunger 52a and the tip of the injection plunger 42a.

[167] The distance between the second pressurization device 17 and the injection device 14 is less than the distance between the first pressurization device 16 and the injection device 14. The distance between the third pressurization device 19 and the injection device 14 is less than the distance between the first pressurization device 16 and the injection device 14.

[168] The third-mode die casting machine includes the first pressurizing device 16, the second pressurizing device 17, and the third pressurizing device, in addition to the injection device 14. The first pressurizing device 16, the second pressurizing device 17, and the third pressurizing device 19 pressurize the molten metal in a region distinct from the product region of the cavity Ca before the solidification of the molten metal filled in the cavity Ca of the mold 18 progresses.

[169] The injection device 14, the first pressurization device 16, the second pressurization device 17, and the third pressurization device 19 apply pressure to the molten metal before solidification progresses in four locations. Therefore, since the pressure is more likely to be transmitted uniformly to the molten metal compared to the die casting machine 100 of the first modality and the die casting machine 200 of the second modality, the cavities can be effectively reduced. Therefore, the casting pressure can be further reduced. Consequently, it is not necessary to further increase the capacity of the mold clamping device or the injection device, and it is possible to reduce the manufacturing cost of the die casting machine.

[170] The third pressure is preferably less than the second pressure. In other words, the second pressure is preferably greater than the third pressure.

[171] The fourth pressure is preferably less than the second pressure. In other words, the second pressure is preferably greater than the fourth pressure.

[172] The pressure applied by the first pressurization device 16, located separately from the injection device 14 that injects the molten metal into the product region Cax, relative to the second pressurization device 17 and the third pressurization device 19, is increased. As a result, the pressure is more likely to be transmitted uniformly to the molten metal, and cavities can be reduced effectively. Furthermore, an unnecessary increase in molten metal pressure and the generation of flash can be avoided.

[173] As described above, in accordance with the third modality, since the first pressurization device 16, the second pressurization device 17, and the third pressurization device 19 are provided, it is possible to realize that the die casting machine is able to further decrease the casting pressure.

[174] As described above, the embodiments of the invention have been described with reference to specific examples. However, the invention is not limited to these specific examples. In the embodiments, although the description of the portion of the die-casting machine or similar that is not directly required for the description of the invention is omitted, the required elements related to the die-casting machine or similar may be appropriately selected and used.

[175] In the first embodiment, an example of a case in which the first pressurizing actuator 54 of the first pressurizing device 16 is provided on the fixed die plate 24 has been described, but the first pressurizing actuator 54 may be provided, for example, on the movable die plate 26, the fixed die 18a, the movable die 18b, or the other portions. The same applies to the installation positions of the second pressurizing actuator 64 of the second embodiment and the second pressurizing actuator 64 and the third pressurizing actuator 94 of the third embodiment.

[176] In the first embodiment, an example of a case in which the first pressurizing plunger 52 is provided on the fixed die 18a has been described, but the first pressurizing plunger 52 may be provided on the movable die 18b.The same applies to the installation positions of the second pressurization piston 62 of the second mode and the second pressurization piston 62 and the third pressurization piston of the third mode.

[177] A case in which two pressurizing devices are provided as the first pressurizing device 16 and the second pressurizing device 17 is exemplified in the second embodiment, and a case in which three pressurizing devices are provided as the first pressurizing device 16, the second pressurizing device 17, and the third pressurizing device 19 is exemplified in the third embodiment. However, four or more pressurizing devices may also be provided.

[178] Furthermore, all die-casting machines having the elements of the invention and appropriately redesigned by those skilled in the art are included within the scope of the invention. The scope of the invention is defined by the scope of the claims and the scope of their equivalents. Explanations of letters or numerals

[179] 10 MOLD CLAMPING DEVICE EXTRUSION DEVICE INJECTION DEVICE FIRST PRESSURIZATION DEVICE SECOND PRESSURIZATION DEVICE MOLD 18a FIXED MATRIX 18b MOVING MATRIX 18x FIRST GUIDE REGION 18th SECOND GUIDE REGION 18z THIRD GUIDE REGION THIRD PRESSURIZATION DEVICE CONTROL UNIT BASE FIXED MATRIX PLATE MOVABLE MATRIX PLATE LINK HOUSING JOINING BAR CONTROL DEVICE (CONTROL UNIT) i Qcnnn / zznz / Ε / γΐΛΐ 32nd MOLDING CONDITION CONFIGURATION UNIT 32b INJECTION CONTROL UNIT 32c PRESSURIZATION CONTROL UNIT INPUT DEVICE DISPLAY DEVICE INJECTION SLEEVE INJECTION PLUNGER 42a INJECTION PISTON TIP 42b INJECTION PLUNGER ROD INJECTION ACTUATOR 44a INJECTION CYLINDER 44b INJECTION PISTON 4x SIDE STEM CHAMBER 4 and SIDE LID CAMERA FIRST HYDRAULIC CIRCUIT (FIRST LIQUID PRESSURE CIRCUIT) POSITION SENSOR FIRST PRESSURIZING PISTON 52a FIRST TIP OF THE PRESSURIZING PISTON 52b FIRST PRESSURIZING PISTON ROD FIRST PRESSURIZATION ACTUATOR 54a FIRST PRESSURIZATION CYLINDER 54b FIRST PRESSURIZING PISTON 54x FIRST STEM-SIDE CHAMBER 54y FIRST CHAMBER ON THE SIDE OF THE COVER i Qcnnn / zznz / Ε / γΐΛΐ SECOND HYDRAULIC CIRCUIT (SECOND LIQUID PRESSURE CIRCUIT) FIRST LOAD SENSOR MOLTEN METAL PRESSURE SENSOR SECOND PRESSURIZATION PISTON 62a SECOND TIP OF THE PRESSURIZING PISTON 62b SECOND PRESSURIZING PISTON ROD SECOND PRESSURIZING ACTUATOR 64a SECOND PRESSURIZING CYLINDER 64b SECOND PRESSURIZING PISTON 64x SECOND STEM-SIDE CHAMBER 64 and SECOND CHAMBER ON THE LID SIDE THIRD HYDRAULIC CIRCUIT (THIRD LIQUID PRESSURE CIRCUIT) SECOND LOAD SENSOR FIRST VALVE FIRST ACCUMULATOR FIRST PRESSURE ABSORBING CYLINDER BOMB TANK PRESSURIZATION SIDE HYDRAULIC SENSOR BACKPRESSURE SIDE HYDRAULIC SENSOR 78a to 78f TUBE SECOND VALVE i Qcnnn / zznz / Ε / γΐΛΐ SECOND ACCUMULATOR SECOND COUNTERPRESSURE ABSORBING CYLINDER BOMB TANK PRESSURIZATION SIDE HYDRAULIC SENSOR (FIRST LIQUID PRESSURE SENSOR) BACKPRESSURE SIDE HYDRAULIC SENSOR (SECOND LIQUID PRESSURE SENSOR) FLOW VELOCITY SENSOR 88a to 88f TUBE 88g TUBE (SHORT CIRCUIT FLOW PATH) DEGASSING VALVE THIRD VALVE 92a THIRD TIP OF THE PRESSURIZING PISTON THIRD PRESSURIZATION ACTUATOR PRESSURIZATION SIDE HYDRAULIC SENSOR BACKPRESSURE SIDE HYDRAULIC SENSOR FLOW VELOCITY SENSOR 98e A 98g TUBE DEGASSING VALVE 100 DIE CASTING MACHINE 200 DIE CASTING MACHINE Ca CAVITY Cax PRODUCT REGION Cay REGION WITHOUT PRODUCT (REGION DIFFERENT FROM THE REGION)

Claims

1. A die casting machine comprising: a base; a fixed die plate fixed to the base and supporting a fixed die; a movable die plate provided on the base to be movable in a mold opening and closing direction and supporting a movable die facing the fixed die; an injection device that fills molten metal into a cavity formed by the fixed die and the movable die and applies a first pressure to the molten metal; a first pressurizing device that pressurizes the molten metal filling the cavity in a region other than the product region of the cavity and applies a second pressure to the molten metal; and a control unit that controls the first pressurizing device so that the second pressure is higher than the first pressure.

2. The die casting machine according to claim 1, wherein the injection device includes an injection sleeve connected to the cavity, an injection plunger that slides in the injection sleeve and applies the first pressure to the molten metal, an injection actuator that moves the injection plunger, and a first liquid pressure circuit that drives the injection actuator, and wherein the first pressurization device includes a first pressurization plunger that applies the second pressure to the molten metal, a first pressurization actuator that moves the first pressurization plunger, and a second liquid pressure circuit that drives the first pressurization actuator.

3. The die casting machine according to claim 2, wherein the first liquid pressure circuit includes a first valve controlling the flow of a first hydraulic fluid flowing in the first liquid pressure circuit and a first accumulator increasing the flow rate of the first hydraulic fluid, and wherein the second liquid pressure circuit includes a second valve controlling the flow of a second hydraulic fluid flowing in the second liquid pressure circuit and a second accumulator increasing the flow rate of the second hydraulic fluid.

4. The die casting machine according to claim 3, wherein the first liquid pressure circuit includes a first backpressure absorption cylinder that increases the flow rate of the first hydraulic fluid, and wherein the second liquid pressure circuit includes a second backpressure absorption cylinder that increases the flow rate of the second hydraulic fluid.

5. The die casting machine according to claim 3 or 4, wherein the first valve and the second valve are servo valves.

6. The die casting machine according to any of claims 2 to 5, wherein the second liquid pressure circuit includes a first liquid pressure sensor provided on a pressurization side of the first pressurization actuator and a second liquid pressure sensor provided on a backpressure side of the first pressurization actuator, and wherein the control unit controls the second pressure based on the measured values ​​of the first liquid pressure sensor and the second liquid pressure sensor.

7. The die casting machine according to any of claims 2 to 6, wherein the second liquid pressure circuit includes a short-circuit flow path that short-circuits a pressurization side and a backpressure side of the first pressurization actuator and a degassing valve provided in the short-circuit flow path and that extracts a gas contained in the second hydraulic liquid.

8. The die casting machine according to any of claims 2 to 7, wherein the second liquid pressure circuit includes a flow rate sensor that measures the flow rate of the second hydraulic fluid and the control unit controls a speed of the first pressurization plunger based on a measurement value from the flow rate sensor.

9. The die casting machine according to any of claims 2 to 8, wherein the first pressurizing actuator is provided on the fixed die plate and the first pressurizing plunger is provided on the fixed die.

10. The die casting machine according to any of claims 2 to 9, wherein the second pressure is 1.1 times or more and 3 times or less than the first pressure.

11. The die casting machine according to any of claims 1 to 10, further comprising: a second pressurization device that pressurizes the molten metal filling the cavity in a region other than the product region of the cavity and applies a third pressure to the molten metal, i Qcnnn / zznz / E / γΐΛΐ wherein the control unit controls the second pressurization device so that the third pressure is higher than the first pressure.

12. The die casting machine according to claim 11, wherein the second pressurization device includes a second pressurization plunger that applies the third pressure to the molten metal, a second pressurization actuator that moves the second pressurization plunger, and a third liquid pressure circuit that drives the second pressurization actuator.

13. The die casting machine according to claim 11 or 12, wherein a distance between the second pressurizing device and the injection device is less than a distance between the first pressurizing device and the injection device, and wherein the control unit controls the first pressurizing device and the second pressurizing device so that the second pressure is higher than the third pressure.

14. The die casting machine according to any of claims 1 to 13, wherein the control unit controls the first pressurization device so that the molten metal i Qcnnn / zznz / E / γΐΛΐ begins to be pressurized within 10 ms after i Qcnnn / zznz / E / YiAi the filling of the molten metal in the cavity is completed.

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