Die casting equipment

Abstract

It suppresses deformation and damage to the die support. [Solution] The die-casting apparatus 10 comprises a fixed mold 20, a movable mold 30 that together with the fixed mold 20 defines a cavity 1a, a fixed platen 40 that holds the fixed mold 20, a movable platen 50 that holds the movable mold 30, a pair of tie bars 60, 60 that connect the fixed platen 40 and the movable platen 50 and are arranged parallel to at least below the fixed mold 20 and the movable mold 30, a die support 70 installed between the fixed mold 20 and the tie bars 60 or between the movable mold 30 and the tie bars 60 and movable along the tie bars 60 with the fixed mold 20 or movable mold 30 positioned thereon, and a lifting cylinder 80 installed on the die support 70 that can raise and lower the fixed mold 20 or movable mold 30 positioned on the die support 70, wherein the lifting cylinder 80 can control the lifting operation in accordance with the thermal expansion or contraction of the fixed mold 20 or movable mold 30.

Description

Technical Field

[0001] The present disclosure relates to a die-casting device.

Background Art

[0002] Conventionally, a die-casting device has been known, which includes a fixed mold, horizontal tie bars provided in a pair above and below at the ends of the fixed mold, a movable mold provided slidably along the tie bars penetrated through the ends, a fixed mold side die support disposed between the pair of lower tie bars between the fixed mold and the movable mold and capable of advancing and retreating in the direction of the fixed mold, and a movable mold side die support capable of advancing and retreating in the direction of the movable mold. Such a die-casting device (injection molding device) is disclosed in, for example, Patent Document 1 below.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when casting a die-cast product using the die-casting device disclosed in Patent Document 1 above, as the molten metal is injected into the cavity defined by the die-casting mold composed of the fixed mold and the movable mold, the temperature of the die-casting mold rises and it thermally expands. Further, with the cooling and solidification of the molten metal and the mold opening operation of the die-casting mold, etc., the temperature of the die-casting mold drops and it thermally contracts. As a result, the die support disposed on the lower side of the die-casting mold may be deformed or damaged due to the influence of the thermal expansion or thermal contraction of the die-casting mold.

[0005] This disclosure has been made in view of the problems present in the prior art described above, and its purpose is to provide a die-casting apparatus that can suppress deformation and damage of the die support even when the die-casting mold undergoes thermal expansion or contraction. [Means for solving the problem]

[0006] The following describes this disclosure. Reference numbers to the attached drawings are indicated in parentheses to facilitate understanding of this disclosure; however, this does not mean that this disclosure is limited to the illustrated forms.

[0007] The die-casting apparatus (10) according to this disclosure includes a fixed mold (20), a movable mold (30) that is movable relative to the fixed mold (20) and together with the fixed mold (20) defines a cavity (1a), a fixed platen (40) installed on the side of the fixed mold (20) opposite to the side defining the cavity (1a) and holding the fixed mold (20), a movable platen (50) installed on the side of the movable mold (30) opposite to the side defining the cavity (1a) and holding the movable mold (30), and a pair of tie bars connecting the fixed platen (40) and the movable platen (50) and arranged parallel to at least below the fixed mold (20) and the movable mold (30). A die-casting apparatus (10) comprising: 60,60) a die support (70) installed between the fixed mold (20) and the tie bar (60) or between the movable mold (30) and the tie bar (60), and movable along the tie bar (60) in the direction of advancement and retraction of the movable mold (30) when the fixed mold (20) or the movable mold (30) is positioned thereon; and a lifting cylinder (80) installed on the die support (70) and capable of raising and lowering the fixed mold (20) or the movable mold (30) positioned on the die support (70), wherein the lifting cylinder (80) is capable of controlling the lifting and lowering operation in accordance with the thermal expansion or thermal contraction of the fixed mold (20) or the movable mold (30).

[0008] Furthermore, in the die-casting apparatus (10) according to this disclosure, the lifting cylinder (80) is a hydraulic cylinder (80) capable of hydraulically controlling the lifting operation in accordance with the thermal expansion or contraction of the fixed type (20) or the movable type (30), and a pressure sensor (90) that senses the pressure change caused by the thermal expansion or contraction of the fixed type (20) or the movable type (30) may be connected to it.

[0009] Furthermore, in the die-casting apparatus (10) according to this disclosure, two lifting cylinders (80) may be installed on each die support (70). [Effects of the Invention]

[0010] According to this disclosure, it is possible to provide a die-casting apparatus that can suppress deformation and damage of the die support even when the die-casting mold undergoes thermal expansion or contraction. [Brief explanation of the drawing]

[0011] [Figure 1] This is a left side view of the die-casting apparatus according to this embodiment. [Figure 2] This is a front view of the movable type according to this embodiment. [Figure 3] This is a schematic diagram illustrating the installation procedure for the fixed type according to this embodiment. Diagram (a) shows the fixed type positioned above the die support, Diagram (b) shows the fixed type raised by a hydraulic cylinder, and Diagram (c) shows the fixed type held in place by a fixed platen. [Figure 4] This is a schematic diagram illustrating the installation procedure of the movable type according to this embodiment. Diagram (a) shows the movable type positioned above the die support, Diagram (b) shows the movable type raised by a hydraulic cylinder, and Diagram (c) shows the movable type held in place by the movable platen. [Figure 5] This is a schematic diagram showing the state in which the movable mold according to this embodiment is brought into contact with the fixed mold and a cavity is defined. [Modes for carrying out the invention]

[0012] Hereinafter, preferred embodiments for implementing this disclosure will be described with reference to the drawings. Note that the following embodiments are not intended to limit the inventions described in each claim, and not all combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0013] First, the configuration of the die-casting apparatus 10 according to this embodiment will be explained using Figures 1 and 2. Here, Figure 1 is a left side view of the die-casting apparatus according to this embodiment. Figure 2 is a front view of the movable type according to this embodiment.

[0014] As shown in Figure 1, the die-casting apparatus 10 according to this embodiment includes a fixed mold 20, a movable mold 30, a fixed platen 40, a movable platen 50, a tie bar 60, a die support 70, and a hydraulic cylinder 80 as a lifting cylinder capable of raising and lowering the fixed mold 20 or the movable mold 30.

[0015] The fixed type 20 includes a fixed die 21 and a fixed holder 22 that houses and fixes the fixed die 21. The movable type 30 is positioned opposite the fixed type 20 and is movable forward and backward relative to the fixed type 20, and includes a movable die 31 and a movable holder 32 that houses and fixes the movable die 31.

[0016] The fixed die 21 and the movable die 31 have a fixed-type cavity defining surface 21a and a movable-type cavity defining surface 31a formed on the opposing surfaces of the two dies. When the movable die 30 moves toward the fixed die 20, the movable-type cavity defining surface 31a comes into contact with the fixed-type cavity defining surface 21a, thereby defining a cavity 1a between the fixed die 20 and the movable die 30.

[0017] The stationary platen 40 is installed facing the stationary platen abutting surface 22a, which is the surface on the opposite side of the stationary mold side cavity forming surface 21a in the stationary mold 20. The stationary platen 40 includes a plurality of holding mechanisms 41 (in this embodiment, 4 each on the right and left, a total of 8) for holding the stationary mold 20 from the side of the stationary platen abutting surface 22a. Further, a sleeve 23 having a hot water inlet (not shown) through which molten metal is introduced is installed on the stationary platen 40.

[0018] The sleeve 23 is formed to penetrate the stationary platen 40 and communicates with the stationary mold side cavity forming surface 21a from the side of the stationary platen abutting surface 22a in the stationary mold 20. Thereby, by injecting molten metal from the hot water inlet side into the cavity 1a defined by the stationary mold 20 and the movable mold 30, a die-cast product corresponding to the shape of the cavity 1a can be obtained.

[0019] The movable platen 50 is installed facing the movable platen abutting surface 32a, which is the surface on the opposite side of the movable mold side cavity forming surface 31a in the movable mold 30. The movable platen 50 includes a plurality of holding mechanisms 51 (in this embodiment, 4 each on the right and left, a total of 8) for holding the movable mold 30 from the side of the movable platen abutting surface 32a. Note that any existing mechanism for holding the stationary mold 20 or the movable mold 30 to the stationary platen 40 or the movable platen 50 can be used for the holding mechanisms 41 and 51. For example, a die clamp, bolts, or the like can be used.

[0020] As shown in detail in FIG. 2, the tie bar 60 has a cylindrical shape extending in the longitudinal direction parallel to the advancing and retreating direction of the movable mold 30, and connects the stationary platen 40 and the movable platen 50 so as to be separable from and abut against each other. Further, the tie bar 60 is composed of a first lower tie bar 60a and a second lower tie bar 60b disposed in parallel below the stationary mold 20 and the movable mold 30, respectively, and a first upper tie bar 60c and a second upper tie bar 60d disposed in parallel above the stationary mold 20 and the movable mold 30, respectively.

[0021] The die support 70 has a through-hole 71 penetrating therethrough, and a total of four die supports 70 are installed between the fixed mold 20 and the first lower tie bar 60a, between the fixed mold 20 and the second lower tie bar 60b, between the movable mold 30 and the first lower tie bar 60a, and between the movable mold 30 and the second lower tie bar 60b, with the through-hole 71 inserted into the cylindrical shape of the tie bar 60. By installing the through-hole 71 of the die support 70 in the cylindrical shape of the tie bar 60, the die support 70 can move along the axial direction of the tie bar 60 (the advancing and retreating direction of the movable mold 30) with the fixed mold 20 or the movable mold 30 disposed above the die support 70.

[0022] The hydraulic cylinder 80 can raise and lower the fixed mold 20 or the movable mold 30 disposed above the die support 70, and two hydraulic cylinders 80 are installed above each of the four die supports 70 installed between the fixed mold 20 and the first lower tie bar 60a, between the fixed mold 20 and the second lower tie bar 60b, between the movable mold 30 and the first lower tie bar 60a, and between the movable mold 30 and the second lower tie bar 60b (a total of eight). Further, each of the eight hydraulic cylinders 80 is connected to a control mechanism (not shown) and a pressure sensor 90. As the connection method between the hydraulic cylinder 80, the control mechanism (not shown), and the pressure sensor 90, any known connection means such as a wired connection or a wireless connection can be used.

[0023] Here, the fixed mold 20 and the movable mold 30 are subject to thermal expansion or contraction due to the high-temperature molten metal injected into the cavity 1a or the influence of the external environment, and the pressure sensor 90 can sense the change in pressure caused by the thermal expansion or contraction occurring in the fixed mold 20 or the movable mold 30. Further, the pressure sensor 90 is installed on the fixed platen 40 or the movable platen 50 and is electrically connected to the control mechanism via an arbitrary connection means.

[0024] The control mechanism (not shown) can hydraulically control the hydraulic cylinder 80 based on the information regarding the change in pressure sensed by the pressure sensor 90.

[0025] In this embodiment, the fixed mold 20 and the movable mold 30 are positioned above the die support 70 via a hydraulic cylinder 80. When the fixed mold 20 and the movable mold 30 expand due to thermal expansion caused by the operation of the die casting apparatus 10, a downward force is applied to the hydraulic cylinder 80, causing the pressure sensor 90 to detect a change in pressure. The control mechanism hydraulically controls the hydraulic cylinder 80 based on the information regarding the pressure change detected by the pressure sensor 90. Specifically, the hydraulic pressure applied to the hydraulic cylinder 80 is reduced to counteract the increase in pressure detected by the pressure sensor 90, thereby lowering the hydraulic cylinder 80 and hydraulically controlling the pressure to keep the pressure value detected by the pressure sensor 90 constant. Through this control operation, even when the fixed mold 20 or the movable mold 30 expands due to thermal expansion, an equilibrium state can be maintained between the fixed mold 20 or the movable mold 30 and the die support 70.

[0026] Furthermore, even when the fixed type 20 or the movable type 30 undergoes thermal contraction, the pressure sensor 90 senses the change in pressure occurring in the hydraulic cylinder 80, and the control mechanism hydraulically controls the hydraulic cylinder 80 based on the information regarding the change in pressure. Specifically, the hydraulic pressure applied to the hydraulic cylinder 80 is increased to counteract the decrease in pressure sensed by the pressure sensor 90, thereby raising the hydraulic cylinder 80 and hydraulically controlling the pressure so that the pressure value sensed by the pressure sensor 90 remains constant. Through the above control operations, even when the fixed type 20 or the movable type 30 undergoes thermal contraction, an equilibrium state can be maintained between the fixed type 20 or the movable type 30 and the die support 70.

[0027] In other words, even if the fixed type 20 or the movable type 30 undergoes thermal expansion or contraction, the hydraulic cylinder 80 can hydraulically control its lifting and lowering operation in response to such thermal expansion or contraction. This prevents the pressure caused by the thermal expansion or contraction of the fixed type 20 or the movable type 30 from directly affecting the die support 70. As a result, a die-casting apparatus 10 is provided that suppresses deformation and damage to the die support 70.

[0028] Furthermore, in this embodiment, the hydraulic cylinders 80 are configured to be installed in pairs on each die support 70. With this configuration, compared to the case where one hydraulic cylinder 80 is installed on each die support 70, it is possible to sense in detail the differences in pressure changes depending on the installation position of each hydraulic cylinder 80, and to control the lifting and lowering operation of the hydraulic cylinders 80 more precisely.

[0029] The configuration of the die-casting apparatus 10 according to this embodiment has been described above using Figures 1 and 2. Next, the installation procedure for the fixed mold 20 and movable mold 30 in the die-casting apparatus 10 according to this embodiment will be described using Figures 3 to 5. Here, Figure 3 is a schematic diagram for explaining the installation procedure for the fixed mold according to this embodiment, with subdivision (a) showing the fixed mold positioned above the die support, subdivision (b) showing the fixed mold raised by the hydraulic cylinder, and subdivision (c) showing the fixed mold held on the fixed platen. Also, Figure 4 is a schematic diagram for explaining the installation procedure for the movable mold according to this embodiment, with subdivision (a) showing the movable mold positioned above the die support, subdivision (b) showing the movable mold raised by the hydraulic cylinder, and subdivision (c) showing the movable mold held on the movable platen. Furthermore, Figure 5 is a schematic diagram showing the state in which the movable mold according to this embodiment is brought into contact with the fixed mold and a cavity is defined.

[0030] First, in the die-casting apparatus 10 according to this embodiment, starting from a state where the fixed mold 20 and movable mold 30 are not installed, the fixed mold 20 is positioned above the die support 70 installed on the first lower tie bar 60a and the second lower tie bar 60b via the hydraulic cylinder 80 (as shown in Figure 3(a)). At this time, the hydraulic cylinder 80 is fully lowered and uncontrolled. Next, the fixed mold 20 is raised by the hydraulic cylinder 80 and adjusted so that the fixed mold 20 is in the correct position relative to the fixed platen 40 (as shown in Figure 3(b)). Furthermore, the die support 70 is moved towards the fixed platen 40 together with the fixed mold 20 positioned above the die support 70, and the fixed mold 20 is held in place on the fixed platen 40 using the holding mechanism 41. At this time, the sleeve 23 is electrically connected between the fixed mold 20 and the fixed platen 40 (as shown in Figure 3(c)). By following these steps, the fixed mold 20 can be fixedly installed on the fixed platen 40.

[0031] Next, with the fixed type 20 fixedly installed on the fixed platen 40, the movable type 30 is positioned above the die support 70 installed on the first lower tie bar 60a and the second lower tie bar 60b via the hydraulic cylinder 80 (as shown in Figure 4(a)). At this time, the hydraulic cylinder 80 above the movable type 30 is fully lowered and uncontrolled. Next, the movable type 30 is raised by the hydraulic cylinder 80 and adjusted so that the movable type 30 is in the correct position relative to the movable platen 50 (as shown in Figure 4(b)). Furthermore, the die support 70, together with the movable type 30 positioned above the die support 70, is moved towards the movable platen 50, and the movable type 30 is held on the movable platen 50 using the holding mechanism 51 (as shown in Figure 4(c)). By following these steps, the movable type 30 can be fixedly installed on the movable platen 50.

[0032] From the state shown in Figure 4(c), the movable mold 30 and movable platen 50 are moved toward the fixed mold 20, and the movable mold side cavity defining surface 31a of the movable die 31 is brought into contact with the fixed mold side cavity defining surface 21a of the fixed die 21, thereby defining a cavity 1a between the fixed mold 20 and the movable mold 30 (the state shown in Figure 5).

[0033] As described above, in the die-casting apparatus 10 according to this embodiment, a die-cast product corresponding to the shape of the cavity 1a can be obtained by injecting molten metal into the cavity 1a. Furthermore, since the fixed mold 20 and the movable mold 30 are positioned above the die support 70 via the hydraulic cylinder 80, even if the fixed mold 20 or the movable mold 30 undergoes thermal expansion or contraction, the hydraulic cylinder 80 can hydraulically control the lifting and lowering operation in response to such thermal expansion or contraction.

[0034] In other words, if the fixed type 20 or the movable type 30 undergoes thermal expansion, the pressure sensed by the pressure sensor 90 will increase. In this case, the hydraulic pressure applied to the hydraulic cylinder 80 is reduced to counteract the increase in pressure sensed by the pressure sensor 90, thereby lowering the hydraulic cylinder 80 and maintaining a constant pressure value sensed by the pressure sensor 90 through hydraulic control. Through this control operation, even if the fixed type 20 or the movable type 30 undergoes thermal expansion, an equilibrium state between the fixed type 20 or the movable type 30 and the die support 70 can be maintained.

[0035] On the other hand, if the fixed type 20 or the movable type 30 shrinks due to heat, the pressure sensed by the pressure sensor 90 will decrease. In this case, the hydraulic pressure applied to the hydraulic cylinder 80 is increased to counteract the decrease in the pressure sensed by the pressure sensor 90, thereby raising the hydraulic cylinder 80 and controlling the hydraulics to keep the pressure value sensed by the pressure sensor 90 constant. Through the above control operations, even if the fixed type 20 or the movable type 30 shrinks due to heat, the equilibrium state between the fixed type 20 or the movable type 30 and the die support 70 can be maintained.

[0036] The operation control described above makes it possible to avoid the pressure caused by thermal expansion or contraction of the fixed mold 20 or movable mold 30 directly affecting the die support 70. Therefore, according to this embodiment, it is possible to provide a die-casting apparatus 10 that suppresses deformation and damage to the die support 70.

[0037] While preferred embodiments of this disclosure have been described above, the technical scope of this disclosure is not limited to the embodiments described above. Various modifications or improvements can be made to the above embodiments.

[0038] In this embodiment, a pressure sensor 90 is connected to the hydraulic cylinder 80, which serves as a lifting cylinder, to sense pressure changes caused by thermal expansion or contraction of the fixed type 20 or movable type 30, and the lifting operation can be hydraulically controlled based on information regarding said pressure changes. However, the lifting cylinder in the die-casting apparatus 10 according to this disclosure can also employ information other than information regarding pressure changes when controlling the lifting operation. For example, the lifting cylinder according to this disclosure can control the lifting operation based on information regarding the weight and center of gravity of the fixed type 20 or movable type 30, in addition to information regarding pressure changes caused by thermal expansion or contraction of the fixed type 20 or movable type 30. By adding information regarding the weight and center of gravity of the fixed type 20 or movable type 30, the lifting operation of the lifting cylinder (hydraulic cylinder 80) can be controlled more precisely.

[0039] It is clear from the claims that such modified or improved forms may also fall within the technical scope of the present invention. [Explanation of symbols]

[0040] 1a Cavity, 10 Die casting device, 20 Fixed mold, 21 Fixed die, 21a Cavity definition surface on the fixed mold side, 22 Fixed holder, 22a Fixed platen contact surface, 23 Sleeve, 30 Movable mold, 31 Movable die, 31a Cavity definition surface on the movable mold side, 32 Movable holder, 32a Movable platen contact surface, 40 Fixed platen, 41 Holding mechanism, 50 Movable platen, 51 Holding mechanism, 60 Tie bar, 60a First lower tie bar, 60b Second lower tie bar, 60c First upper tie bar, 60d Second upper tie bar, 70 Die support, 80 Hydraulic cylinder (lifting cylinder), 90 Pressure sensor.

Claims

1. Fixed type, A movable type that is movable forward and backward relative to the fixed type and together with the fixed type defines a cavity, A fixed platen is installed on the side of the fixed mold opposite to the surface defining the cavity, and holds the fixed mold. A movable platen is installed on the side of the movable mold opposite to the surface defining the cavity, and holds the movable mold. A pair of tie bars are provided to connect the fixed platen and the movable platen, and are arranged parallel to at least the fixed type and the movable type below them. A die support is installed between the fixed type and the tie bar or between the movable type and the tie bar, and is movable along the tie bar in the direction of advancement of the movable type when the fixed type or the movable type is positioned, A lifting cylinder installed on the die support and capable of raising and lowering the fixed type or the movable type positioned on the die support, A die-casting apparatus equipped with, The die-casting apparatus is characterized in that the lifting cylinder can control its lifting motion in accordance with the thermal expansion or contraction of the fixed or movable type.

2. A die-casting apparatus according to claim 1, The die-casting apparatus is characterized in that the lifting cylinder is a hydraulic cylinder capable of hydraulically controlling its lifting operation in response to the thermal expansion or contraction of the fixed or movable type, and is connected to a pressure sensor that senses changes in pressure caused by the thermal expansion or contraction of the fixed or movable type.

3. A die-casting apparatus according to claim 1 or 2, The die-casting apparatus is characterized in that two of the aforementioned lifting cylinders are installed on each of the die supports.

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