Molding machine

Abstract

To provide a technique for retaining a movable die plate in a desired position.SOLUTION: A molding machine comprises an inclination frame that is mounted on a mount surface in a state that a support face is directed obliquely upward, a mold-clamping device that is supported by the support face and for opening / closing and clamping a metal die, and an injection device that is supported upper than the mold-clamping device on the support face and for injecting a molding material into a cavity. The mold-clamping device comprises a fixed die plate that is fixed on the support face and supports a fixed-side metal die, a movable die plate that supports the movable-side metal die lower than the fixed die plate on the support face, a die opening-and-closing cylinder that moves the movable die plate along the support face in an upstream direction for the movable-side metal die to move toward the fixed-side metal die and in a downstream direction for it to move away therefrom, and a lock mechanism that can be changed over to a permission state allowing a movement of the movable die plate in the upstream and downstream directions and to a prevention state allowing the movement of the movable die plate in the upstream direction and preventing the movement thereof in the downstream direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a molding machine that injects a molding material into a mold to form a molded product.

Background Art

[0002] Conventionally, there is known a molding machine including a mold clamping device that opens and closes and clamps a fixed mold and a movable mold, and an injection device that injects a molding material into a cavity formed inside the fixed mold and the movable mold clamped by the mold clamping device.

[0003] In the molding machine having the above configuration, there is a problem that when the injection device injects the molding material, it entrains air and causes surface defect or porosity defect. Therefore, Patent Documents 1 to 4 disclose a molding machine inclined such that the injection device is positioned obliquely above the mold clamping device for the purpose of solving such problems.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, as described in Patent Documents 1-4, when the molding machine is tilted, gravity acts on the movable die plate in a direction that separates the movable mold from the fixed mold. Furthermore, the greater the weight of the movable mold, the greater the gravitational force acting on the movable die plate. As a result, a new problem arises: it becomes difficult to hold the movable die plate in the desired position.

[0006] The present invention was made to solve the problems of the prior art, and its objective is to provide a technique for holding a movable die plate in a desired position in a molding machine inclined so that the injection device is located diagonally above the clamping device. [Means for solving the problem]

[0007] To solve the above problems, the present invention provides a molding machine comprising: an inclined frame placed on a mounting surface with its support surface facing diagonally upward; a mold clamping device supported on the support surface for opening, closing and clamping a fixed-side mold and a movable-side mold; and an injection device supported on the support surface above the mold clamping device for injecting molding material into cavities formed inside the fixed-side mold and the movable-side mold clamped by the mold clamping device, wherein the mold clamping device comprises: a fixed die plate fixed to the support surface and supporting the fixed-side mold; a movable die plate below the support surface above the fixed die plate and supporting the movable-side mold; a mold opening / closing cylinder for moving the movable die plate along the support surface in an upward direction to bring the movable-side mold closer to the fixed-side mold and a downward direction to move it further away; and a locking mechanism that can be switched between an allowable state that permits the upward and downward movement of the movable die plate and a blocking state that permits the upward movement of the movable die plate and prevents the downward movement. [Effects of the Invention]

[0008] According to the present invention, in a molding machine inclined such that the injection device is located diagonally above the clamping device, the movable die plate can be held in a desired position. [Brief explanation of the drawing]

[0009] [Figure 1] This is a side view of the die-casting machine according to this embodiment. [Figure 2] This is a schematic diagram of the clamping device. [Figure 3] This is a view of the locking mechanism from the upstream side in the upward direction. [Figure 4] This is a schematic diagram of a hydraulic circuit that supplies and discharges hydraulic fluid to a type opening and closing cylinder. [Figure 5] This is a schematic diagram of the injection device. [Figure 6] This is an enlarged view of the hydraulic fluid flow path around the injection device. [Figure 7] This is a hardware configuration diagram of a die-casting machine. [Figure 8] This is a flowchart of the movable die plate locking process. [Figure 9] This diagram shows the flow chart for the mold closing process and the change in flow rate of the flow control valve during the mold closing process. [Figure 10] This diagram shows the spray device in its operating position. [Figure 11] This is a diagram showing a spray device in an intermediate position. [Figure 12] This is a diagram showing a spray device in a retracted position. [Modes for carrying out the invention]

[0010] Figure 1 is a side view of the die-casting machine 10 according to this embodiment. The die-casting machine 10 is a device that manufactures molded products by injecting molten metal into a mold. However, the specific example of a molding machine is not limited to the die-casting machine 10, and an injection molding machine that forms molded products by injecting resin (molding material) into a mold may also be used. As shown in Figure 1, the die-casting machine 10 mainly comprises an inclined frame 11, a mold clamping device 20, an injection device 30, and a hydraulic oil supply unit 40.

[0011] The inclined frame 11 has an outer shape of a right triangle when viewed from the side. The inclined frame 11 is placed on the placement surface G with the portion corresponding to the hypotenuse of the right triangle (hereinafter referred to as "support surface 12") facing obliquely upward. Usually, the placement surface G is a horizontal plane. The support surface 12 is inclined at a predetermined angle (for example, 30°) with respect to the placement surface G. However, the inclination angle of the support surface 12 with respect to the placement surface G is not limited to the above example. Also, the inclination angle of the support surface 12 with respect to the placement surface G may be fixed or variable.

[0012] The clamping device 20 and the injection device 30 are supported by the support surface 12 of the inclined frame 11. The clamping device 20 is supported by the support surface 12 obliquely below the injection device 30. The injection device 30 is supported by the support surface 12 obliquely above the clamping device 20. On the other hand, the hydraulic oil supply unit 40 is installed on the placement surface G at a position different from the inclined frame 11.

[0013] The clamping device 20 opens and closes and clamps the mold 21. Specifically, the clamping device 20 mainly includes a fixed die plate 22a that supports the fixed-side mold 21a and a movable die plate 22b that supports the movable-side mold 21b. The fixed die plate 22a is fixed to the support surface 12 obliquely below the injection device 30 and obliquely above the movable die plate 22b. The movable die plate 22b is supported by the support surface 12 obliquely below the fixed die plate 22a. The fixed-side mold 21a and the movable-side mold 21b are arranged to face each other in the inclination direction of the support surface 12.

[0014] Also, the movable die plate 22b is configured to be movable along the support surface 12 in a direction to bring the movable-side mold 21b into contact with and separate from the fixed-side mold 21a. Hereinafter, the direction to bring the movable-side mold 21b closer to the fixed-side mold 21a (the upper right direction in FIG. 1) is referred to as the "upward direction", and the direction to separate the movable-side mold 21b from the fixed-side mold 21a (the lower left direction in FIG. 1) is referred to as the "downward direction".

[0015] Figure 2 is a schematic configuration diagram of the mold clamping device 20. As shown in Figure 2, the mold clamping device 20 includes, as components for separating and approaching the movable mold 21b from the fixed mold 21a (in other words, opening, closing, and clamping the mold 21), a tailstock 23, tie bars 24a and 24b, drive nuts 25a and 25b, a drive motor 26, a toggle link mechanism 27, a mold opening and closing cylinder 28, and a lock mechanism 29.

[0016] The tailstock 23 is supported by the support surface 12 obliquely downward from the movable die plate 22b. Also, the tailstock 23 is configured to be movable in the upward and downward directions along the support surface 12. The tie bars 24a and 24b extend parallel to the support surface 12 between the fixed die plate 22a and the tailstock 23. Also, the tie bars 24a and 24b are inserted through the movable die plate 22b. Then, the movable die plate 22b is guided by the tie bars 24a and 24b and moves in the upward and downward directions.

[0017] At the ends of the tie bars 24a and 24b on the side of the tailstock 23, thread portions 24c and 24d are formed on the outer peripheral surface. The thread portions 24c and 24d of the tie bars 24a and 24b penetrate through the tailstock 23 and project to the side opposite to the movable die plate 22b. And the drive nuts 25a and 25b are screwed onto the thread portions 24c and 24d that have penetrated through the tailstock 23. The drive motor 26 generates a driving force for rotating the drive nuts 25a and 25b.

[0018] When the drive motor 26 rotates in the first direction, the drive nuts 25a and 25b move upward along the threaded portions 24c and 24d. As a result, the movable die plate 22b, tailstock 23, toggle link mechanism 27, mold opening / closing cylinder 28, and locking mechanism 29 move upward as a unit. On the other hand, when the drive motor 26 rotates in the second direction, opposite to the first direction, the drive nuts 25a and 25b move downward along the threaded portions 24c and 24d. As a result, the movable die plate 22b, tailstock 23, toggle link mechanism 27, mold opening / closing cylinder 28, and locking mechanism 29 move downward as a unit.

[0019] The toggle link mechanism 27 is connected at one end to the movable die plate 22b and at the other end to the tailstock 23. The toggle link mechanism 27 is configured to extend and retract between the movable die plate 22b and the tailstock 23. The open / close cylinder 28 is supported by the tailstock 23. The open / close cylinder 28 extends and retracts the toggle link mechanism 27 when hydraulic fluid is supplied from the hydraulic fluid supply unit 40. The hydraulic circuit that supplies hydraulic fluid to the open / close cylinder 28 will be described later with reference to Figure 4.

[0020] When the toggle link mechanism 27 extends, the movable die plate 22b moves upward relative to the tailstock 23. This causes the movable mold 21b to come into contact with the fixed mold 21a (mold closing). If further pressure is applied in the direction that moves the movable die plate 22b upward, the fixed mold 21a and the movable mold 21b are clamped together. On the other hand, when the toggle link mechanism 27 contracts, the movable die plate 22b moves downward relative to the tailstock 23. This causes the movable mold 21b to separate from the fixed mold 21a (mold opening).

[0021] The tailstock 23 and tie bars 24a, 24b are formed from, for example, FCD450, SCM435, or a combination thereof. On the other hand, the drive nuts 25a, 25b are formed from, for example, a material with lower hardness than the sliding tailstock 23 and tie bars 24a, 24b (e.g., HBSC2). However, the combination of materials forming the tailstock 23, tie bars 24a, 24b, and drive nuts 25a, 25b is not limited to the examples described above.

[0022] Figure 3 is a view of the locking mechanism 29 from the upstream side (i.e., the lower left side) in the upward direction. The locking mechanism 29 is responsible for preventing the movable die plate 22b from moving downward due to gravity. More specifically, the locking mechanism 29 is configured to be switchable between the blocking state shown in Figure 3(A) and the allowing state shown in Figure 3(B). As shown in Figures 2 and 3, the locking mechanism 29 according to this embodiment mainly comprises a ratchet member 29a, a locking block 29b, an air cylinder 29c, and a limit switch 29d.

[0023] The ratchet member 29a is a long, rod-shaped member that extends in the direction of movement of the movable die plate 22b. The ratchet member 29a is attached to the movable die plate 22b and moves together with the movable die plate 22b. Ratchet teeth 29e (locking members) are formed on the upper surface of the ratchet member 29a. The ratchet teeth 29e are formed at multiple positions spaced apart in the direction of movement of the movable die plate 22b. However, there may be just one ratchet tooth 29e. The ratchet tooth 29e has a first surface 29f and a second surface 29g.

[0024] The first surface 29f is the downstream side (upper right side in Figure 2) of the ratchet teeth 29e in the upward direction. The first surface 29f has an upward slope in the downward direction. In other words, the inclination angle of the first surface 29f is set to an angle that allows the locked block 29b to ride up when the movable die plate 22b moves in the upward direction.

[0025] The second surface 29g is the downstream side (lower left side in Figure 2) of the ratchet teeth 29e in the downward direction. The second surface 29g is perpendicular to the direction of movement of the movable die plate 22b. However, the inclination angle of the second surface 29g is not limited to the example described above, and is not limited to any angle that allows the locking block 29b to be locked when the movable die plate 22b attempts to move in the downward direction.

[0026] As shown in Figure 3, the locking block 29b has a roughly rectangular parallelepiped shape. The locking block 29b is supported on the tailstock 23 so as to be rotatable around a pivot axis 29h that extends in the direction of movement of the movable die plate 22b. The air cylinder 29c is supported on the tailstock 23 on one side of the pivot axis 29h (the left end in Figure 3) and above the locking block 29b. The air cylinder 29c expands and contracts vertically as compressed air is supplied and discharged. The limit switch 29d detects the locking block 29b when the air cylinder 29c is extended.

[0027] As shown in Figure 3(A), when the air cylinder 29c contracts, the locking block 29b rotates clockwise. This causes one end of the locking block 29b to rise and the other end to descend. As a result, the other end (locking member) of the locking block 29b is positioned to contact the ratchet teeth 29e in the direction of movement of the movable die plate 22b.

[0028] At this time, when the movable die plate 22b moves upward, the other end of the locking block 29b rides up onto the first surface 29f of the ratchet teeth 29e, causing the locking block 29b to rotate counterclockwise around the pivot axis 29h. As a result, upward movement of the movable die plate 22b is permitted. On the other hand, when the movable die plate 22b attempts to move downward, the other end of the locking block 29b contacts and locks against the second surface 29g of the ratchet teeth 29e. As a result, downward movement of the movable die plate 22b is prevented.

[0029] On the other hand, as shown in Figure 3(B), when the air cylinder 29c extends, the locking block 29b rotates counterclockwise. This causes one end of the locking block 29b to descend and the other end to rise. As a result, the other end of the locking block 29b retracts above the ratchet teeth 29e. Consequently, regardless of whether the movable die plate 22b moves upward or downward, the other end of the locking block 29b does not come into contact with the ratchet teeth 29e. In other words, the movable die plate 22b can move in both the upward and downward directions.

[0030] In other words, the state of the locking mechanism 29 shown in Figure 3(A) is an example of a blocking state in which upward movement of the movable die plate 22b is permitted and downward movement is prevented. The state of the locking mechanism 29 shown in Figure 3(B) is an example of a permitting state in which upward and downward movement of the movable die plate 22b is permitted. The limit switch 29d then detects that the locking mechanism 29 has entered a blocking state and outputs a detection signal indicating the detection result to the control device 60 (see Figure 7), which will be described later.

[0031] Figure 4 is a schematic diagram of the hydraulic circuit that supplies and discharges hydraulic fluid to the mold opening / closing cylinder 28. As shown in Figure 4, the die-casting machine 10 mainly includes a directional control valve 51 and a flow control valve 52 as hydraulic components that supply and discharge hydraulic fluid to the mold opening / closing cylinder 28.

[0032] The directional control valve 51 switches the direction of the supply of hydraulic fluid to the type opening / closing cylinder 28. The directional control valve 51 is an electromagnetic switching valve that can be switched between an upward position A, a downward position B, and a shut-off position C according to the control of the control device 60.

[0033] The upward position A is the position in which hydraulic fluid, pressurized by the hydraulic pump 42 of the hydraulic fluid supply unit 40, is supplied to the head chamber of the die opening / closing cylinder 28, and the hydraulic fluid discharged from the rod chamber of the die opening / closing cylinder 28 is recirculated to the hydraulic fluid tank 41 of the hydraulic fluid supply unit 40. In other words, when the directional control valve 51 is switched to the upward position A, the die opening / closing cylinder 28 extends. As a result, the movable die plate 22b moves in the upward direction.

[0034] Downward position B is the position in which hydraulic fluid, pressurized by the hydraulic pump 42 of the hydraulic fluid supply unit 40, is supplied to the rod chamber of the die opening / closing cylinder 28, and the hydraulic fluid discharged from the head chamber of the die opening / closing cylinder 28 is recirculated to the hydraulic fluid tank 41 of the hydraulic fluid supply unit 40. In other words, when the directional control valve 51 is switched to the downward position B, the die opening / closing cylinder 28 retracts. As a result, the movable die plate 22b moves in the downward direction.

[0035] The shut-off position C is the position that shuts off both the inflow of hydraulic fluid, pumped by the hydraulic pump 42, into the mold opening / closing cylinder 28, and the discharge of hydraulic fluid from the mold opening / closing cylinder 28. In other words, the shut-off position C is the position that shuts off the connection between the hydraulic pump 42 and the mold opening / closing cylinder 28, and the connection between the mold opening / closing cylinder 28 and the hydraulic fluid tank 41. That is, the shut-off position C is a so-called "all-port block" that blocks all ports: the port connected to the head chamber of the mold opening / closing cylinder 28, the port connected to the rod chamber of the mold opening / closing cylinder 28, the port connected to the hydraulic fluid tank 41, and the port connected to the hydraulic pump 42.

[0036] The flow control valve 52 is located in the flow path from the hydraulic pump 42 to the directional control valve 51. The flow control valve 52 controls (increases or decreases) the flow rate of hydraulic fluid from the hydraulic pump 42 to the directional control valve 51 according to the control of the control device 60. More specifically, the flow control valve 52 controls (increases or decreases) the amount of hydraulic fluid per unit time supplied from the hydraulic pump 42 to the open / closed cylinder 28 through the directional control valve 51. The specific process of controlling the directional control valve 51 and the flow control valve 52 will be described later with reference to Figures 8 and 9.

[0037] Figure 5 is a schematic diagram of the injection device 30. Figure 6 is an enlarged view of the hydraulic fluid flow path around the injection device 30. The injection device 30 injects molten metal (molding material) into the clamped mold 21. The injection device 30 mainly comprises an injection sleeve 31 (sleeve), a plunger 32, and an injection cylinder 33.

[0038] The injection sleeve 31 is a cylindrical component attached to the fixed die plate 22a. The tip of the injection sleeve 31 communicates with the internal space (hereinafter referred to as "cavity") of the clamped mold 21. The injection sleeve 31 also extends upward from the fixed mold 21a. Molten metal supplied by a ladle (not shown) is stored in the injection sleeve 31.

[0039] The plunger 32 is housed within the injection sleeve 31 so as to be able to move back and forth. When the plunger 32 moves forward in the downward direction, molten metal stored in the injection sleeve 31 is supplied to the cavity. On the other hand, when the plunger 32 moves backward in the upward direction, a space for storing molten metal supplied from the ladle is formed within the injection sleeve 31.

[0040] The injection cylinder 33 moves the plunger 32 forward and backward as it expands and contracts due to the supply and discharge of hydraulic fluid. When hydraulic fluid is supplied to the head chamber of the injection cylinder 33 and discharged from the rod chamber, the injection cylinder 33 extends. This causes the plunger 32 to move forward within the injection sleeve 31. On the other hand, when hydraulic fluid is supplied to the rod chamber of the injection cylinder 33 and discharged from the head chamber, the injection cylinder 33 contracts. This causes the plunger 32 to retract within the injection sleeve 31.

[0041] The die-casting machine 10 mainly includes an accumulator 34, a check valve 35, a pilot valve 36, on / off valves 37 and 39, and a supply / discharge control valve 38 as hydraulic components for supplying and discharging hydraulic fluid to and from the injection cylinder 33. The pilot valve 36, on / off valves 37 and 39, and supply / discharge control valve 38 are electromagnetic switching valves that switch the state of the flow path according to the control of the control device 60.

[0042] The accumulator 34 stores (accumulates) the hydraulic fluid supplied from the hydraulic pump 42 in a compressed state through the on / off valve 39, and supplies the compressed hydraulic fluid to the head chamber of the injection cylinder 33 and the pilot port of the check valve 35. The check valve 35 opens and closes the flow path from the accumulator 34 to the head chamber of the injection cylinder 33. The pilot valve 36 is configured to be switchable between a supply position in which hydraulic fluid is supplied from the accumulator 34 to the pilot port of the check valve 35, and a recirculation position in which hydraulic fluid is recirculated from the pilot port of the check valve 35 to the hydraulic fluid tank 41.

[0043] The on / off valve 37 opens and closes the flow path from the head chamber of the injection cylinder 33 to the hydraulic oil tank 41. The supply and discharge control valve 38 is configured to be switchable between a supply position, in which hydraulic oil pumped from the hydraulic pump 42 is supplied to the rod chamber of the injection cylinder 33, and a return position, in which hydraulic oil discharged from the rod chamber of the injection cylinder 33 is returned to the hydraulic oil tank 41. The on / off valve 39 opens and closes the flow path from the hydraulic pump 42 to the accumulator 34.

[0044] When the injection cylinder 33 is extended, the pilot valve 36 is set to the supply position, the on / off valve 37 closes the flow path, and the supply / discharge control valve 38 is set to the recirculation position. As a result, the check valve 35 opens the flow path, and hydraulic fluid is supplied from the accumulator 34 to the head chamber of the injection cylinder 33. In addition, hydraulic fluid is recirculated from the rod chamber of the injection cylinder 33 to the hydraulic fluid tank 41 through the supply / discharge control valve 38.

[0045] On the other hand, when the injection cylinder 33 is retracted, the pilot valve 36 is set to the recirculation position, the on / off valve 37 opens the flow path, and the supply / discharge control valve 38 is set to the supply position. As a result, the check valve 35 closes the flow path, stopping the supply of hydraulic fluid from the accumulator 34 to the head chamber of the injection cylinder 33. In addition, hydraulic fluid is supplied from the hydraulic pump 42 to the rod chamber of the injection cylinder 33 through the supply / discharge control valve 38. Furthermore, hydraulic fluid is recirculated from the head chamber of the injection cylinder 33 to the hydraulic fluid tank 41 through the on / off valve 37.

[0046] Furthermore, as shown in Figure 6, a spacer 50 is attached to the injection device 30. When the spacer 50 is attached to the injection device 30, it is shaped so that its upper surface is parallel to the mounting surface G, canceling out the inclination angle of the inclined frame 11. The accumulator 34 is then supported on the upper surface (i.e., the horizontal plane) of the spacer 50, which is parallel to the mounting surface G.

[0047] The hydraulic fluid supply unit 40 is a unitized collection of hydraulic components necessary for supplying and discharging hydraulic fluid to the mold opening / closing cylinder 28 and the injection cylinder 33, and for supplying hydraulic fluid to the accumulator 34. In addition to the aforementioned hydraulic fluid tank 41 and hydraulic pump 42, the hydraulic fluid supply unit 40 includes a pump motor 43 for driving the hydraulic pump 42, an oil cleaner for removing foreign matter from the hydraulic fluid, and an oil cooler for cooling the hydraulic fluid.

[0048] The flow path connecting the hydraulic actuators (i.e., the mold opening / closing cylinder 28, the injection cylinder 33, and the accumulator 34) to the hydraulic fluid supply unit 40 is constructed by combining a steel pipe 44 and a flexible hose 45. More specifically, the end of the flow path on the hydraulic fluid supply unit 40 side is made up of a hose 45.

[0049] Here, when the injection cylinder 33 is extended, hydraulic fluid is discharged instantaneously at high speed from the rod chamber of the injection cylinder 33, so the generation of surge pressure is expected. Therefore, as shown in Figures 5 and 6, surge absorption cylinders 46 and 47 are installed in the flow path from the rod chamber of the injection cylinder 33 to the hydraulic fluid tank 41 (in other words, the flow path that recirculates the hydraulic fluid discharged from the rod chamber of the injection cylinder 33 to the hydraulic fluid tank 41).

[0050] The surge absorption cylinders 46 and 47 play a role in absorbing the pressure of the hydraulic fluid (i.e., surge pressure) by increasing the volume of the space in which the hydraulic fluid flowing through the flow path communicates with the flow path. The surge absorption cylinders 46 and 47 are installed at positions spaced apart in the direction of hydraulic fluid flow. Preferably, the surge absorption cylinders 46 and 47 are installed, for example, at the bending points of the steel pipe 44, or perpendicular to the direction of hydraulic fluid flow.

[0051] Figure 7 is a hardware configuration diagram of the die-casting machine 10. The die-casting machine 10 includes a control device 60. The control device 60 includes, for example, a CPU (Central Processing Unit) 61 which is a calculation means, a ROM (Read Only Memory) 62 which stores various programs, and a RAM (Random Access Memory) 63 which serves as a workspace for the calculation means. The CPU 61 may read and execute the programs stored in the ROM 62 to realize the various processes described later.

[0052] However, the specific configuration of the control device 60 is not limited to this and may be implemented using hardware such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field-Programmable Gate Array).

[0053] The control device 60 controls the operation of the entire die-casting machine 10. More specifically, the control device 60 controls the operation of the drive motor 26, air cylinders 29c and 75, pilot valve 36, on / off valve 37, supply / discharge control valve 38, pump motor 43, directional control valve 51, and flow control valve 52 based on various signals output from the limit switch 29d, door sensor 64, and display input device 65.

[0054] The door sensor 64 detects the opening and closing of a door (not shown) that is rotatably installed on the front of the die-casting machine 10, and outputs an open / closed signal indicating the detection result to the control device 60. The door is positioned facing the mold 21. That is, when the door is closed, the operator cannot access the mold 21, and the die-casting machine 10 is in a state where it can manufacture molded products. On the other hand, when the door is open, the operator can access the mold 21, and the die-casting machine 10 is in a state where it cannot manufacture molded products.

[0055] The display input device 65 is a user interface that includes a display for displaying various information to be communicated to the operator, and buttons, switches, dials, etc., for receiving operations from the operator. The display input device 65 may also include a touch panel superimposed on the display. The display input device 65 receives input operations from the operator and outputs an input signal corresponding to the received input operation to the control device 60.

[0056] The display input device 65 includes, for example, a [Mode Switching] button, a [Mold Closing] button, and a [Mold Opening] button. The [Mode Switching] button accepts the operation to switch between a manual mode in which the die-casting machine 10 operates at a set speed and pressure, and a mold exchange mode in which the mold 21 is replaced. The [Mold Closing] button accepts the operation to close the mold 21. The [Mold Opening] button accepts the operation to open the mold 21.

[0057] In the die-casting machine 10 in manual mode, when the [close mold] button and the [open mold] button are operated, the control device 60 opens and closes the mold 21 at a preset speed and pressure via the display input device 65. On the other hand, in the die-casting machine 10 in mold change mode, when the [close mold] button and the [open mold] button are operated, the control device 60 opens and closes the mold 21 at a regulated speed and pressure (i.e., a slower speed and lower pressure than in manual mode).

[0058] The control device 60 moves the movable die plate 22b upward by switching the directional control valve 51 to the upward position A while the [Mold Close] button is operated. The control device 60 also moves the movable die plate 22b downward by switching the directional control valve 51 to the downward position B while the [Mold Open] button is operated. This allows the operator to maintain a desired distance between the fixed mold 21a and the movable mold 21b. Furthermore, when the operation of the [Mold Close] and [Mold Open] buttons is completed, the control device 60 switches the directional control valve 51 to the shut-off position C. This prevents the movable die plate 22b from moving downward due to gravity, thus maintaining the distance set by the operator.

[0059] Figure 8 is a flowchart of the movable die plate locking process. The movable die plate locking process is a process of switching the state of the locking mechanism 29 in order to prevent the movable die plate 22b from moving downwards when the operator changes the mold 21.

[0060] First, the control device 60 locks the movable die plate 22b in the die opening / closing stop position, regardless of mode switching or the opening / closing of the safety door. More specifically, the control device 60 lowers the other end of the locking block 29b by retracting the air cylinder 29c (S11). This switches the locking mechanism 29 from the permitted state to the blocked state.

[0061] As a result, the downward movement of the movable die plate 22b is double-locked by the directional control valve 51 in the shut-off position C and the locking mechanism 29 in the blocked position. Next, the operator opens the door and performs the task of replacing the mold 21. After replacing the mold 21, the operator closes the door. Details of the method for replacing the mold 21 will be described later with reference to Figures 10 to 12.

[0062] When the replacement of the mold 21 is complete, the control device 60 outputs a signal to extend the air cylinder 29c, attempting to raise the other end of the locking block 29b (S12). However, due to the weight of the movable mold 21b and the movable die plate 22b, the other end of the locking block 29b may be strongly pressed against the ratchet teeth 29e, potentially preventing the locking block 29b from rotating. Therefore, the control device 60 determines, based on the detection signal from the limit switch 29d, whether the locking mechanism 29 has switched from a blocked state to an allowed state (S13).

[0063] If the locking mechanism 29 does not switch to the permissible state even after the control device 60 outputs a signal to extend the air cylinder 29c (S13: No), the control device 60 switches the directional control valve 51 to the up position B (S14). Then, with the directional control valve 51 switched to the up position B (S14), the control device 60 outputs a signal to extend the air cylinder 29c, causing the other end of the locked block 29b to retract upward (S12). Then, if the locking mechanism 29 is switched from the blocked state to the permissible state (S13: Yes), the control device 60 switches the directional control valve 51 to the shut-off position C (S15).

[0064] Figure 9 shows a flowchart of the mold closing process and the flow rate of the flow control valve 52 during the mold closing process. The mold closing process involves moving the movable die plate 22b upward to bring the movable side mold 21b closer to the fixed side mold 21a (i.e., closing the mold 21). At the start of the mold closing process, the movable side mold 21b is separated from the fixed side mold 21a, and the directional control valve 51 is assumed to be in the shut-off position C.

[0065] First, the control device 60 waits to execute the processes from step S22 onward until it receives a mold closing instruction (S21: No). The mold closing instruction may be, for example, an instruction to execute injection molding via the display input device 65, or it may be obtained by operating the [Mold Closing] button.

[0066] Then, when the control device 60 receives a mold closing instruction (S21: Yes), it switches the directional control valve 51 from the shut-off position C to the up position B (S22). However, there is a time lag between the switching of the directional control valve 51 to the up position B and the supply of hydraulic fluid to the head chamber of the mold opening / closing cylinder 28, which causes the mold opening / closing cylinder 28 to begin extending. Therefore, due to the weight of the movable mold 21b and the movable die plate 22b, the movable die plate 22b may move downward during this time lag.

[0067] Therefore, the control device 60 sets the flow rate of the flow control valve 52 to the first flow rate in parallel with switching the directional control valve 51 to the upward position B (S23). Then, the control device 60 waits for a predetermined time to elapse (S24: No) after setting the flow rate of the flow control valve 52 to the first flow rate before executing the process from step S25 onward. The predetermined time is set, for example, to the time required from switching the directional control valve 51 to the upward position B until the mold opening / closing cylinder 28 begins to extend stably.

[0068] Then, the control device 60 sets the flow rate of the flow control valve 52 to the second flow rate (S25) after a predetermined time has elapsed since setting the flow rate of the flow control valve 52 to the first flow rate (S24: Yes). The second flow rate is the flow rate set via the display input device 65. Note that the relative magnitudes of the first and second flow rates are not limited to the example in Figure 9(B). That is, as shown in Figure 9(B), the control device 60 sets the flow control valve 52 to the first flow rate for a predetermined time after switching the directional control valve 51 from the shut-off position C to the up position A, and then operates at the set second flow rate after the predetermined time has elapsed.

[0069] As shown in Figure 1, the die-casting machine 10 further includes a spray device 70. The spray device 70 is a device that sprays fluid onto the mold surfaces (i.e., surfaces defining the cavity) of the opened fixed-side mold 21a and movable-side mold 21b. The fluid includes, for example, a liquid release agent or air.

[0070] Figure 10 shows the spray device 70 in the operating position. Figure 11 shows the spray device 70 in the intermediate position. Figure 12 shows the spray device 70 in the retracted position. As shown in Figures 10 to 12, the spray device 70 mainly comprises a stand 71, a spray body 72, a nozzle 73, a winch 74 (first drive source), and an air cylinder 75 (second drive source).

[0071] The stand 71 is erected on the fixed die plate 22a (more specifically, on the C-shaped frame attached to the fixed die plate 22a). The stand 71 is also configured to be rotatable around the first pivot shaft 76. The first pivot shaft 76 extends in a direction perpendicular to the direction of movement and vertical direction of the movable die plate 22b (i.e., the depth direction of the paper in Figures 10 to 12).

[0072] The stand 71 rotates between a position extending perpendicular to the direction of movement of the movable die plate 22b (Figures 10 and 11) and a position tilted away from the movable die plate 22b (in other words, away from the inter-mold region 79 described later) (Figure 12). Although Figure 12 shows the stand 71 extended in the vertical direction, the specific rotation angle between the stand 71 shown in Figures 10 and 11 and the stand 71 shown in Figure 12 is not limited, as long as it rotates away from the movable die plate 22b from the state shown in Figures 10 and 11.

[0073] The spray body 72 is supported at the upper end of the stand 71. The spray body 72 also supports the nozzle 73. The spray body 72 stores compressed fluid and sprays the stored fluid through the nozzle 73. Furthermore, the spray body 72 is configured to rotate around the second pivot axis 77 relative to the stand 71. With the stand 71 perpendicular to the direction of movement of the movable die plate 22b, the spray body 72 rotates between a position where the nozzle 73 is held in a position overlapping the mold inter-mold region 79 when viewed from above (Figure 10) and a position where the nozzle 73 is held outside the mold inter-mold region 79 when viewed from above (Figure 11). Furthermore, the spray body 72 supports the nozzle 73 so that it can move up and down in the extending direction of the stand 71.

[0074] The winch 74 rotates the stand 71 around the first pivot shaft 76 by winding in and unwinding a wire 78 whose tip is connected to the stand 71. In this embodiment, the winch 74 allows the operator to manually adjust the amount of wire 78 wound in and unwound. However, the first drive source is not limited to a manual winch 74, but may be an electric winch or an air cylinder, etc. The air cylinder 75 rotates the spray body 72 around the second pivot shaft 77 by extending and retracting according to the control of the control device 60. However, the second drive source is not limited to an air cylinder 75, but may be an electric motor, etc.

[0075] The spray device 70 shown in Figures 10 and 11 overlaps the mold-to-mold region 79 when viewed from above. Therefore, when attempting to lift and replace the fixed mold 21a and the movable mold 21b using a winch or the like, the spray device 70 interferes. To address this, the spray device 70 according to this embodiment is configured to allow for changes in posture between the operating posture shown in Figure 10, the intermediate posture shown in Figure 11, and the retracted posture shown in Figure 12. The mold-to-mold region 79 refers to the area between the opened fixed mold 21a and the movable mold 21b.

[0076] The operating position shown in Figure 10 is one in which the stand 71 is extended in a direction perpendicular to the direction of movement of the movable die plate 22b, and the nozzle 73 is held in a position that allows it to enter the mold inter-mold region 79. When the nozzle 73 is lowered in the operating position shown in Figure 10, the nozzle 73 enters the mold inter-mold region 79. Then, by spraying fluid from the nozzle 73 that has entered the mold inter-mold region 79, the mold release agent and air can be applied to the mold surface.

[0077] The intermediate position shown in Figure 11 is a position in which the stand 71 is extended in a direction perpendicular to the direction of movement of the movable die plate 22b, and the nozzle 73 is held in a position outside the mold inter-mold region 79 when viewed from above. Even if the nozzle 73 is lowered in the intermediate position of Figure 11, the nozzle 73 cannot enter the mold inter-mold region 79. However, the spray device 70 as a whole still overlaps the mold inter-mold region 79 when viewed from above, so it interferes when changing the mold 21.

[0078] The retracted position shown in Figure 12 is a position in which the stand 71 is rotated to the opposite side of the movable die plate 22b until the entire spray device 70 is removed from the mold inter-mold area 79 when viewed from above. Even if the nozzle 73 is lowered in the retracted position shown in Figure 12, the nozzle 73 cannot enter the mold inter-mold area 79. Also, since the entire spray device 70 is removed from the mold inter-mold area 79 when viewed from above, it does not interfere when replacing the mold 21.

[0079] In this embodiment, the spray device 70 changes its posture from an operating position to an intermediate position and then to a retracted position. Specifically, the spray device 70 moves from the operating position to an intermediate position by rotating the spray body 72 around the second rotation axis 77. Furthermore, the spray device 70 moves from the intermediate position to a retracted position by winding up the wire 78.

[0080] Furthermore, the spray device 70 according to this embodiment changes its posture from a retracted position to an intermediate position and then to a usage position. That is, when the spray device 70 extends the wire 78 from the retracted position, it enters the intermediate position. Also, when the spray device 70 rotates the spray body 72 around the second rotation axis 77 from the intermediate position, it enters the usage position.

[0081] According to the above embodiment, for example, the following effects are achieved.

[0082] According to the above embodiment, by providing a locking mechanism 29 that prevents the movable die plate 22b from moving downward, even when the mold clamping device 20 is installed on the inclined frame 11, gravity can prevent the movable die plate 22b from unintentionally moving downward. As a result, the movable die plate 22b can be held in a desired position, for example, during mold replacement work of the mold 21.

[0083] Furthermore, according to the above embodiment, the aforementioned effects can be obtained with a simple configuration by configuring the locking mechanism 29 with the ratchet member 29a and the locked block 29b. However, the specific configuration of the locking mechanism 29 is not limited to the examples in Figures 2 and 3. In addition, by providing ratchet teeth 29e at multiple positions spaced apart in the direction of movement of the movable die plate 22b, the options for positions in which the movable die plate 22b can be held can be increased.

[0084] Furthermore, according to the above embodiment, when changing the state of the locking mechanism 29 from a blocked state to an allowed state, the directional control valve 51 is switched to the upward position B. This releases the state in which the other end of the locked block 29b is pressed against the second surface 29g of the ratchet teeth 29e, allowing the locking mechanism 29 to change state smoothly.

[0085] Furthermore, according to the above embodiment, by setting the shut-off position C of the directional control valve 51 to all-port block, it is possible to prevent the movable die plate 22b from unintentionally moving downwards due to gravity. Moreover, by employing both the locking mechanism 29 and the directional control valve 51, the downward movement of the movable die plate 22b can be double-locked.

[0086] Furthermore, according to the above embodiment, when moving the movable die plate 22b in the upward direction, the flow rate of hydraulic fluid supplied to the head chamber of the die opening / closing cylinder 28 is increased during the initial predetermined time. This prevents the movable die plate 22b from moving in the downward direction before the die opening / closing cylinder 28 begins to extend.

[0087] Furthermore, according to the above embodiment, by making the hydraulic fluid supply unit 40 self-supporting on the mounting surface G at a position different from the inclined frame 11, the die-casting machine 10 can be made lower in height compared to when it is placed on the inclined frame 11. In addition, by configuring the end of the flow path connecting the hydraulic actuator to the hydraulic fluid supply unit 40 on the hydraulic fluid supply unit 40 side with a flexible hose 45, the degree of freedom in the layout of the hydraulic fluid supply unit 40 is improved.

[0088] Furthermore, according to the above embodiment, surge pressure can be appropriately absorbed by providing multiple surge absorption cylinders 46 and 47 in the flow path from the rod chamber of the injection cylinder 33 to the hydraulic oil tank 41. As a result, even if the proportion of flexible hoses 45 is increased to increase the layout flexibility of the hydraulic oil supply unit 40, it is possible to prevent the hoses 45 from vibrating due to surge pressure.

[0089] Furthermore, according to the above embodiment, the accumulator 34 is supported on the upper surface of the spacer 50 which is parallel to the mounting surface G. This prevents damage to the Prada from occurring when the Prada is used in a tilted position within the shell.

[0090] Furthermore, when the clamping device 20 is installed on the inclined frame 11, there is a possibility of galling occurring in the sliding parts between the tailstock 23 and tie bars 24a, 24b and the drive nuts 25a, 25b. Therefore, as in the above embodiment, by forming the drive nuts 25a, 25b from a material with lower hardness than the tailstock 23 and tie bars 24a, 24b, the easily replaceable drive nuts 25a, 25b can be actively worn down.

[0091] Furthermore, according to the above embodiment, by changing the position of the spray device 70 between the operating position and the retracted position, the spray device 70 can be retracted from a position that overlaps with the inter-mold area 79 when the mold 21 is replaced. As a result, even when the clamping device 20 is installed on the inclined frame 11, the mold 21 can be replaced by suspending it with a winch without interfering with the spray device 70.

[0092] Furthermore, according to the above embodiment, by changing the spray device 70's position from the intermediate position to the operating position and the retracted position, it is possible to more effectively prevent the spray device 70 from overlapping the mold inter-molding region 79. However, the specific method for changing the position of the spray device 70 is not limited to the example described above, and the intermediate position may be omitted (in other words, the rotation of the spray body 72 relative to the stand 71 is omitted), and the position may be changed directly from the operating position to the retracted position.

[0093] The embodiments described above are illustrative for explaining the present invention and are not intended to limit the scope of the invention to those embodiments only. Those skilled in the art can implement the present invention in various other forms without departing from the spirit of the invention. [Explanation of symbols]

[0094] 10…Die casting machine, 11…Inclined frame, 12…Support surface, 20…Clamping device, 21…Mold, 21a…Fixed mold, 21b…Movable mold, 22a…Fixed die plate, 22b…Movable die plate, 23…Tailstock, 24a,24b…Tie bar, 24c,24d…Screw part, 25a,25b…Drive nut, 26…Drive motor, 27…Toggle link mechanism, 28…Mold opening / closing cylinder, 29…Locking mechanism, 29a…Ratchet member, 29b…Locking block, 29c,75…Air cylinder, 29d…Limit switch, 29e…Ratchet teeth, 29f…First surface, 29g…Second surface, 29h…Rotating shaft, 30…Injection device, 31…Injection sleeve, 32… Plunger, 33…Injection cylinder, 34…Accumulator, 35…Check valve, 36…Pilot valve, 37,39…On / off valves, 38…Intake / exhaust control valve, 40…Hydraulic oil supply unit, 41…Hydraulic oil tank, 42…Hydraulic pump, 43…Pump motor, 44…Steel pipe, 45…Hose, 46,47…Surge absorption cylinder, 50…Spacer, 51…Direction control valve, 52…Flow control valve, 60…Control device, 61…CPU, 62…ROM, 64…Door sensor, 65…Display input device, 70…Spray device, 71…Stand, 72…Spray body, 73…Nozzle, 74…Winch, 76…First rotation axis, 77…Second rotation axis, 78…Wire, 79…Inter-mold area

Claims

1. An inclined frame is placed on the mounting surface with its support surface facing diagonally upward, A clamping device supported on the aforementioned support surface opens and closes and clamps the fixed mold and the movable mold, A molding machine comprising an injection device supported above the clamping device on the support surface, which injects molding material into cavities formed inside the fixed mold and the movable mold clamped by the clamping device, The clamping device is, A fixed die plate fixed to the support surface and supporting the fixed side mold, Below the support surface, on the side below the fixed die plate, is a movable die plate that supports the movable mold, A mold opening / closing cylinder moves the movable die plate along the support surface in an upward direction to bring the movable die closer to the fixed die and a downward direction to move it away from the fixed die, A molding machine characterized by comprising a locking mechanism that can switch between an allowable state that permits movement of the movable die plate in the upward and downward directions, and a blocking state that permits movement of the movable die plate in the upward direction and prevents movement in the downward direction.

2. The clamping device comprises a tailstock supported on the support surface on the side opposite to the fixed die plate, with the movable die plate in between, The locking mechanism is A locking member that moves together with the movable die plate, The locking member is supported by the tailstock, retracts above the locking member in the permissible state, and contacts the locking member in the blocked state, The first surface of the locking member on the downstream side in the upward direction is inclined at an angle such that the locked member can ride up when the movable die plate moves in the upward direction. The molding machine according to claim 1, characterized in that the second surface of the locking member on the downstream side in the downward direction is set at an angle that locks the locked member when the movable die plate attempts to move in the downward direction.

3. The molding machine according to claim 2, characterized in that the locking mechanism comprises a plurality of locking members spaced apart in the direction of movement of the movable die plate.

4. A hydraulic pump that pressurizes the hydraulic fluid, A directional control valve that can switch between supplying hydraulic fluid, pumped by the hydraulic pump, to the mold opening / closing cylinder in an upward position that moves the movable die plate upward, and a downward position that supplies hydraulic fluid in a downward position that moves the movable die plate downward, The molding machine according to claim 2, further comprising a control device that switches the locking mechanism from the blocked state to the permitted state by retracting the locked member above the locked member while the directional control valve is switched to the raised position.

5. The molding machine according to claim 4, further characterized in that the directional control valve is configured to be switchable to a shut-off position that shuts off both the inflow of hydraulic fluid pressurized by the hydraulic pump into the mold opening / closing cylinder and the discharge of hydraulic fluid from inside the mold opening / closing cylinder.

6. The hydraulic fluid supply unit comprises a hydraulic fluid tank for storing hydraulic fluid and a hydraulic pump for pumping the hydraulic fluid stored in the hydraulic fluid tank, which is unitized to be self-supporting on the aforementioned mounting surface at a position different from the inclined frame. The molding machine according to claim 1, characterized in that the end of the flow path connecting a hydraulic actuator, which operates by being supplied with and discharged with hydraulic fluid, to the hydraulic fluid supply unit is made of a flexible hose, on the side of the hydraulic fluid supply unit.

7. The injection device is, A sleeve communicating with the aforementioned cavity, A plunger that advances within the sleeve toward the cavity, thereby supplying the molding material within the sleeve to the cavity, The device comprises an injection cylinder that advances the plunger when hydraulic fluid is supplied to the head chamber and retracts the plunger when hydraulic fluid is supplied to the rod chamber, The molding machine according to claim 6, characterized in that a plurality of surge absorption cylinders for absorbing surge pressure are attached to the flow path that recirculates the hydraulic fluid discharged from the rod chamber of the injection cylinder to the hydraulic fluid supply unit.

8. A spacer attached to the injection device such that its upper surface is parallel to the aforementioned mounting surface, The molding machine according to claim 7, further comprising an accumulator supported on the upper surface of the spacer and supplying pre-pressurized hydraulic fluid to the head chamber.

9. An inclined frame is placed on the mounting surface with its support surface facing diagonally upward, A clamping device supported on the aforementioned support surface opens and closes and clamps the fixed mold and the movable mold, A molding machine comprising an injection device supported above the clamping device on the support surface, which injects molding material into cavities formed inside the fixed mold and the movable mold clamped by the clamping device, The clamping device is, A fixed die plate fixed to the support surface and supporting the fixed side mold, Below the support surface, on the side below the fixed die plate, is a movable die plate that supports the movable mold, The system includes a mold opening / closing cylinder that moves the movable die plate along the support surface in an upward direction to bring the movable die closer to the fixed die and in a downward direction to move it away from the fixed die, A hydraulic pump that pressurizes the hydraulic fluid, The system includes a directional control valve that switches the supply direction of the hydraulic fluid, which is pumped by the hydraulic pump, to the type opening / closing cylinder, The aforementioned directional control valve is An upward position that supplies the movable die plate in a direction that moves it upward, A downward position that supplies the movable die plate in a direction that moves it downward, A molding machine characterized by being configured to be switchable between a shut-off position that shuts off both the inflow of hydraulic fluid, which is pumped by the hydraulic pump, into the mold opening / closing cylinder and the discharge of hydraulic fluid from inside the mold opening / closing cylinder.

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