Local transformer device and molding machine

Abstract

To provide a local transformer device having a simplified configuration.SOLUTION: A local transformer device 31 includes a drive part (pressurizing cylinder 35) that causes an advance and retreat member 33 to advance. The advance and retreat member 33 can advance to a space 107 and retreat to an opposite side in a state where a distal end is exposed to the space 107 formed by a mold (stationary mold 103). The pressurizing cylinder 35 includes a fixation member (cylinder member 37) and a movable member (piston member 39). When receiving a drive force to move with respect to the cylinder member 37, the piston member 39 (directly or indirectly) presses a rear end of the advance and retreat member 33. The piston member 39 is not connected to any member exposed to the space 107 including the advance and retreat member 33, and is relatively movable in a direction away from the rear end of the advance and retreat member 33.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a local pressure transformer and a molding machine including the local pressure transformer. The local pressure transformer locally applies pressure to and / or locally absorbs pressure from the molding material inside the mold. The local pressure transformer includes, for example, a local pressure applying device and / or a surge pressure absorbing device. The molding material is, for example, a metal material in a molten (liquid) state (hereinafter, sometimes referred to as "molten metal"). [Background technology]

[0002] In molding methods such as die casting, a local pressure device that applies so-called local pressure is known (for example, Patent Document 5 below). In this technology, after a mold is filled with molding material, a pressure pin is protruded into the mold, thereby pressing the molding material. As a result, for example, shrinkage cavities caused by solidification shrinkage of the molding material are reduced.

[0003] Patent Document 5 discloses a surge pressure absorbing device that uses a local pressure device. The surge pressure absorbing device keeps a pressure pin at its forward limit before the molding material is filled into the mold, and then retracts the pressure pin using the pressure of the molten metal once the molding material has been filled into the mold. This reduces the instantaneous increase in pressure (surge pressure) that occurs when the molding material is filled into the mold.

[0004] Patent Document 5 also discloses that in a hydraulic cylinder that drives a pressure pin, the cylinder chamber to which hydraulic fluid is supplied when the pressure pin is retracted may be open to the atmosphere. Patent Document 1 is not related to a molding method, but discloses a pneumatic cylinder whose cylinder chamber is open to the atmosphere. Patent Documents 2 to 4 are not related to local pressurization, but disclose hydraulic cylinders that perform air bleeding. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-54117 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-207792 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-207657 [Patent Document 4] Japanese Patent Application Laid-Open No. 2002-31101 [Patent Document 5] Japanese Patent Application Publication No. 2023-66640 Summary of the Invention [Problem to be solved by the invention]

[0006] For example, there is a need for a local transformer device and a molding machine with a simplified configuration. [Means for solving the problem]

[0007] A local transformer device according to one aspect of the present disclosure has a drive unit that advances a reciprocating member whose tip is exposed in a space defined by a mold and which can move forward into the space and backward to the opposite side, the drive unit having a fixed member and a movable member that is applied with a driving force that moves relative to the fixed member and pushes the rear end of the reciprocating member, the movable member not being connected to any member exposed in the space, including the reciprocating member, and is movable relative to the rear end of the reciprocating member in a direction away from each other.

[0008] A molding machine according to one embodiment of the present disclosure includes the above-mentioned local transformer device, a clamping device that opens and closes a pair of molds including the above-mentioned molds as fixed or movable molds, and an injection device that injects molding material into the space. [Effects of the Invention]

[0009] According to the above configuration, for example, the configuration of the local pressure applying device can be simplified. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a side view showing a configuration of a die casting machine according to an embodiment. [Figure 2] 1 is a cross-sectional view showing the configuration of a local transformer device according to an embodiment. [Figure 3] 3 is a cross-sectional view illustrating the operation of the local transformer device of FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view showing a continuation of FIG. 3. [Figure 5] FIG. 5 is a cross-sectional view showing a continuation of FIG. 4. [Figure 6] FIG. 3 is a circuit diagram showing the configuration and operation of a hydraulic system of the local transformer device of FIG. 2. [Figure 7] Circuit diagram showing a continuation of Figure 6. [Figure 8] Circuit diagram showing a continuation of Figure 7. [Figure 9] 9(a) and 9(b) are cross-sectional views showing other examples of local transformer devices. DETAILED DESCRIPTION OF THE INVENTION

[0011] The drawings used in the following description are schematic. Therefore, for example, details may be omitted, or specific shapes and / or dimensions may be exaggerated. Furthermore, the detailed configurations may not match between drawings. However, the above does not deny that features such as shapes and / or dimensions may be extracted based on the drawings.

[0012] (Outline of the embodiment) FIG. 1 is a side view (partially including a cross-sectional view) showing a schematic configuration of a die-casting machine 1 (an example of a molding machine) according to an embodiment. The up-down direction along the plane of the drawing is the vertical direction. The die-casting machine 1 produces a die-cast product (a molded product in a broader sense) by filling the interior (space 107) of a mold 101 with molten metal (not shown).

[0013] The die 101 is replaceable by the user. Therefore, the die 101 may be considered not to be part of the die-casting machine 1, or may be considered to be part of the die-casting machine 1. In the description of the embodiments, expressions that assume either way of thinking may be used unless otherwise specified.

[0014] 2 to 5 are cross-sectional views showing the configuration of the local transformer device 31 (hereinafter sometimes simply referred to as "transformer device 31") of the die-casting machine 1. These figures correspond to enlarged views of a portion of FIG. 1, and show the upper part of the die 101 and its surroundings. FIG. 2 shows the die 101 in a state before it is attached to the die-casting machine 1 (more specifically, to the fixed die plate 21 described later). FIGS. 3 to 5 show the die 101 in a state after it has been attached to the die-casting machine 1. FIGS. 3 to 5 also serve to explain the operation of the transformer device 31. The operation proceeds in the order of FIGS. 3, 4, and 5.

[0015] The transformer device 31 according to the embodiment functions as a surge pressure absorber and a local pressurizing device. Unlike the description of the embodiment, the transformer device 31 may function as only one of a surge pressure absorber and a local pressurizing device. Because local pressurizing devices are generally well known, for convenience, the description of the embodiment may use names of the components that focus on their function as local pressurizing devices.

[0016] The pressure transformer 31 has a reciprocating member 33 that is moved in and out of the space 107, and a pressure cylinder 35 (an example of a drive unit) that drives the reciprocating member 33.

[0017] The advancing / retreating member 33 can be replaced by a user together with the die 101 and / or separately from replacing the die 101. Therefore, the advancing / retreating member 33 may be considered not to be part of the die casting machine 1, or may be considered to be part of the die casting machine 1. In the description of the embodiments, expressions that assume either way of understanding may be used unless otherwise specified.

[0018] The term "drive unit" is a generic concept of the pressure cylinder 35. In this disclosure, the term "drive unit" refers to a unit that actively generates a driving force, such as a hydraulic, pneumatic, or electric unit, or a combination thereof. In other words, the term "drive unit" in this disclosure does not include an elastic member.

[0019] When the pressure transformer 31 functions as a surge pressure absorber, as can be seen from a comparison of Figures 3 and 4, the molten metal ML filled in the space 107 pushes the advancing / retreating member 33 backward (toward the opposite side of the space 107), causing the advancing / retreating member 33 to retreat. At this time, the energy with which the molten metal ML retracts the advancing / retreating member 33 is transmitted to the pressure cylinder 35 and consumed appropriately. This reduces the so-called surge pressure. The reduction in surge pressure reduces the likelihood of flash formation, for example. In other words, the quality of the product improves.

[0020] When the pressure transformer 31 functions as a local pressurizing device, as can be seen from a comparison of FIGS. 4 and 5, the advancing / retreating member 33 advances (moves into the space 107) due to the driving force of the pressurizing cylinder 35. This pressurizes the molten metal ML, increasing the pressure of the molten metal ML. That is, local pressurization is performed. The local pressurization reduces, for example, shrinkage cavities. That is, the quality of the product is improved.

[0021] The pressure cylinder 35 has, for example, a cylinder member 37 (an example of a fixed member) and a piston member 39 (an example of a movable member) that moves relative to the cylinder member 37. The piston member 39 has a piston 41 located inside the cylinder member 37 and a rod 43 extending from the piston 41 to the outside of the cylinder member 37.

[0022] 2 and 3, the tip of piston member 39 is merely capable of coming into contact with the rear end of advancing / retreating member 33, and the two are not connected to each other. In other words, piston member 39 and advancing / retreating member 33 are capable of relative movement in directions away from each other. Furthermore, other than advancing / retreating member 33, there is no other member that is exposed to space 107 and fixed to piston member 39.

[0023] According to such a configuration, for example, a joint for connecting the advancing / retreating member 33 (and other members exposed to the space 107) to the piston member 39 is not required, which simplifies the configuration of the pressure transformer 31. Furthermore, since there is no need to secure an area for arranging a joint within the mold 101, the structure of the mold 101 is also simplified.

[0024] Normally, it is substantially impossible to connect the advancing / retreating member 33 and the pressure cylinder 35 after the die 101 has been attached to the die casting machine 1. For this reason, conventionally, the pressure cylinder 35 has been attached to the die 101 (not attached to the die casting machine 1). However, in this embodiment, the advancing / retreating member 33 and the pressure cylinder 35 are not connected, so the pressure cylinder 35 can be provided in the die casting machine 1.

[0025] As a result, for example, the structure of the mold 101 is further simplified. For example, it is not necessary to provide an area for arranging the pressurizing cylinder 35 in the mold 101, and it is also not necessary to provide a flow path for supplying hydraulic fluid to the pressurizing cylinder 35. From a viewpoint other than simplification, it is also economical because it is not necessary to replace the pressurizing cylinder 35 when replacing the mold 101.

[0026] Since the advancing / retreating member 33 and the pressure cylinder 35 are not connected, even if a driving force in the retracting direction is applied to the piston member 39, the advancing / retreating member 33 cannot be retracted by being pulled by the piston member 39. The retraction of the advancing / retreating member 33 may be achieved, for example, by the surge pressure absorption operation described above alone. Also, because of the above, the pressure cylinder 35 does not have to have the function of retracting the piston member 39, as will be described later.

[0027] The above is an outline of the embodiment. The following describes the embodiment in the following order: 1. Die-casting machine (Fig. 1) 2.Moving parts 2.1.Moving parts in general 2.2.Advance and retreat member in the illustrated example 3. Drive unit of the transformer (pressure cylinder) 3.1. Drive unit in general 3.2. Drive unit of the illustrated example Position Sensor 4. Hydraulic system of the transformer (Figs. 6 to 8) 4.1.Configuration from pressure cylinder to accumulator 4.2.Configuration from pump to pressure cylinder 4.3.Other configurations of hydraulic systems 5. Operation of transformer equipment 5.1. Standby Operation (Fig. 3 and Fig. 6) 5.2. Absorption of surge pressure (Figures 4 and 7) 5.3. Localized pressure (Fig. 5 and Fig. 8) 5.4. Preparation for the next cycle 6. Other examples of transformer devices 7. Summary of embodiments

[0028] (1. Die casting machine as a whole) As described in the overview of the embodiment above, the die-casting machine 1 illustrated in Fig. 1 injects a liquid metal material (molten metal) into a die 101. Note that instead of the molten metal, a metal material in a solid-liquid coexistence state may be used. The type of metal is arbitrary, and may be, for example, aluminum or an aluminum alloy.

[0029] The mold 101 is basically made of, for example, metal and has a fixed mold 103 and a movable mold 105 that moves in the mold opening / closing direction (horizontal in the illustrated example) relative to the fixed mold 103. The space 107 described above is formed between them. In FIG. 1, for convenience, the cross section of the fixed mold 103 or the movable mold 105 is shown with a single type of hatching. However, these molds may be of a direct engraving type or a nesting type. Furthermore, the fixed mold 103 and the movable mold 105 may be combined with a core or the like. The fixed mold 103 and / or the movable mold 105 may include a die base.

[0030] The die-casting machine 1 may have various configurations, excluding the configuration related to the transformer device 31, and may have, for example, the same configuration as a known configuration. Note that, as for configurations and operations that may be known configurations and operations, descriptions thereof will be omitted as appropriate.

[0031] The die-casting machine 1 has, for example, a machine main body 3 that performs mechanical operations for molding, a controller 5 that controls the operation of the machine main body 3, and an interface 13 that mediates between the controller 5 and an operator. The machine main body 3 has, for example, a mold clamping device 7 that opens, closes, and clamps the mold 101, an injection device 9 that injects molten metal into the clamped mold 101, an extrusion device 11 that extrudes the die-cast product from the fixed mold 103 or the movable mold 105 (the movable mold 105 in FIG. 1), and a spray device 15 that sprays the mold 101.

[0032] During the molding cycle, the mold clamping unit 7 moves the movable mold 105 toward the fixed mold 103 to close the mold. Furthermore, the mold clamping unit 7 applies a clamping force to the mold 101 according to the extension amount of the tie bars (reference numerals omitted) to clamp the mold. A space 107 is formed inside the clamped mold 101. The injection unit 9 injects and fills the space 107 with molten metal. The molten metal in the space 107 loses heat to the mold 101, cools, and solidifies. In other words, the molten metal becomes a molded product. The mold clamping unit 7 then moves the movable mold 105 away from the fixed mold 103 to open the mold. At this time, or thereafter, the extrusion unit 11 extrudes the molded product from the movable mold 105. After the mold is opened, the spray unit 15 applies a mold release agent to the surfaces of the fixed mold 103 and the movable mold 105 that form the space 107.

[0033] The specific configuration of the machine body 3 is arbitrary. For example, the die-casting machine 1 may be any of a horizontal clamping horizontal injection type (illustrated example), a horizontal clamping vertical injection type, a vertical clamping horizontal injection type, and a vertical clamping vertical injection type, or may be a type that cannot be classified as any of these. Furthermore, the die-casting machine 1 may be any of a cold chamber machine (illustrated example), a hot chamber machine, or a semi-hot chamber machine that is a combination of both, or may be a type that cannot be classified as any of these.

[0034] Furthermore, for example, the mold clamping unit 7 may be one that performs mold opening / closing and mold clamping using a toggle mechanism (as shown in the example), or one that performs mold opening / closing and mold clamping using separate drive units. The latter may be one that directly extends tie bars using a mold clamping cylinder, or one that performs mold opening / closing with the movement of a toggle mechanism and then performs mold clamping using a toggle mechanism. The drive units for the mold clamping unit 7 and the injection unit 9, etc., may be hydraulic (for example, hydraulic), electric, or a hybrid type that combines hydraulic and electric drive systems.

[0035] In the illustrated example, the mold clamping device 7 has a fixed die plate 21 that holds the fixed die 103, and a movable die plate 23 that holds the movable die 105. The fixed die plate 21 and the movable die plate 23 face each other. The opposing surfaces serve as mounting surfaces 21a and 23a to which the fixed die 103 or the movable die 105 is attached. The movable die plate 23 moves relative to the fixed die plate 21 to open and close the mold.

[0036] The controller 5 may be configured to include, for example, a computer (not shown). The computer may be configured to include, for example, a central processing unit (CPU), read-only memory (ROM), random access memory (RAM), and an auxiliary storage device (not shown). The CPU executes programs stored in the ROM and / or the auxiliary storage device to configure various functional units that perform various calculations (including control). The controller 5 may also include a logic circuit that executes certain operations, a power supply circuit, or a driver. The controller 5 may be provided in, for example, a control panel (not shown). Part of the controller 5 may also be configured as part of the interface 13. The controller 5 (and each component of the controller 5) may be integrated into one hardware location or distributed across multiple locations.

[0037] In the above, the controller 5 has been described as a part of the die-casting machine 1. However, when focusing on each device included in the die-casting machine 1, the controller 5 may be regarded as a controller included in that device. For example, the controller 5 may be regarded as a controller included in the transformer device 31.

[0038] (2. Retractable member) The die casting machine 1 may have any number of advancing and retracting members 33, equal to or greater than one. In an embodiment in which multiple advancing and retracting members 33 are provided, for example, surge pressure can be absorbed at various positions on the die 101, reducing the likelihood of flash formation, and / or localized pressure can be applied to the molten metal in the die 101 more uniformly. However, in the following description, for convenience, the description may focus on one advancing and retracting member 33 unless otherwise specified.

[0039] The shape of the advancing / retreating member 33 shown in Fig. 2 may be generally pin-shaped with the advancing / retreating direction as the longitudinal direction (as shown in the example), or it may not be pin-shaped. An example of the latter is a block shape with a diameter larger than the length of the advancing / retreating member 33 in the advancing / retreating direction. The shape of the cross section (cross section perpendicular to the advancing / retreating direction) of the advancing / retreating member 33 may be circular or may be a shape other than circular. The advancing / retreating member 33 may be solid or hollow. The dimensions of the advancing / retreating member 33 are also arbitrary.

[0040] In a pin-shaped embodiment, the advancing / retreating member 33 may have the same or similar configuration as, for example, a known pressure pin (a pin for applying local pressure). In this case, the pressure pin does not need to have a portion (e.g., a flange) for connection with the pressure cylinder 35. This, for example, can simplify the configuration of the pressure pin. However, the pressure pin may have a portion for connection (not used for connection in this embodiment). In this case, the pressure pin is shared with an embodiment in which connection is performed (an embodiment different from this embodiment). In other words, the versatility of the pressure pin is improved, and ultimately, productivity is improved.

[0041] The advancing / retreating member 33 may be arranged in the fixed mold 103 (as shown in the example) or in the movable mold 105. In the description of this embodiment, for convenience, the description may be made on the assumption that the advancing / retreating member 33 is arranged in the fixed mold 103 unless otherwise specified.

[0042] For example, a part or all of the advancing / retreating member 33 may slide relative to (or in contact with) the mold (the fixed mold 103 or the movable mold 105). When the advancing / retreating member 33 is positioned at the forward limit and / or backward limit relative to the mold, the rear end may be positioned outside or inside the mold.

[0043] The advancing and retracting direction of the advancing and retracting member 33 may be any appropriate direction. For example, the advancing and retracting direction may be the mold opening and closing direction, or may be a direction intersecting (perpendicular or inclined) the mold opening and closing direction. However, if the advancing and retracting direction is the mold opening and closing direction, the advancing and retracting member 33 can be separated from the molded product, for example, in conjunction with the operation of peeling the molded product from the mold in which the advancing and retracting member 33 is placed.

[0044] The position of the advancing / retreating member 33 relative to the space 107 may be set as appropriate. For example, although not shown, the space 107 has a product section having a shape corresponding to the shape of the product, a runner that guides the molten metal from the injection device 9 to the product section, and an overflow into which excess molten metal flows. The advancing / retreating member 33 may be located on the inner surface of any of these spaces.

[0045] In the following description, unless otherwise specified, the case where the advancing / retreating member 33 is positioned at the overflow position is sometimes taken as an example. In this case, the time when the molding material reaches the advancing / retreating member 33 and the time when surge pressure occurs are closer than in a case where the advancing / retreating member 33 is positioned at another part of the space 107. For the sake of convenience, the two times may not be distinguished.

[0046] The forward movement limit of the advancing / retreating member 33 may be determined, for example, by providing a portion (stopper) on the mold 101 that abuts (or engages in another sense) with the advancing / retreating member 33 from the front. The backward movement limit of the advancing / retreating member 33 may be determined in the same manner as the forward movement limit described above, or may be determined by the backward movement limit of the piston member 39 (movable member).

[0047] (2.2. Retractable member in the illustrated example) 2 is generally pin-shaped (in other words, a pressure pin), but has several features that are different from known pressure pins.

[0048] For example, the advancing / retreating member 33 does not have a portion (for example, a flange) for connection with the pressure cylinder 35. Specifically, in the illustrated example, the rear end portion of the advancing / retreating member 33 extends with a constant diameter, and the outer periphery thereof does not have any irregularities.

[0049] Furthermore, for example, the advancing / retreating member 33 has a sliding portion 33a located on the front end side. The sliding portion 33a has a larger diameter than the portion adjacent to the sliding portion 33a on the rear end side. As a result, the length of the advancing / retreating member 33 that can slide on the mold 101 (more specifically, the guide bush 45 thereof) is shorter than the length of the advancing / retreating member 33. The length of the sliding portion 33a is arbitrary. However, it may be relatively short. For example, the length may be 0.8 to 1.2 times the diameter of the sliding portion 33a. Note that the advancing / retreating member 33 may have a portion closer to the front end than the sliding portion 33a that has a smaller diameter than the sliding portion 33a. The length of the guide bush 45 may be shorter than, equal to, or longer than the length of the sliding portion 33a (in the illustrated example).

[0050] Furthermore, for example, the advancing / retreating member 33 has an abutting portion 33b that abuts against the mold 101 (more specifically, the guide bush 45 in the illustrated example) from behind, thereby defining the forward movement limit of the advancing / retreating member 33. Note that in the illustrated example, the backward movement limit of the advancing / retreating member 33 is defined by the backward movement limit of the piston member 39.

[0051] Furthermore, for example, when the advancing / retreating member 33 is positioned at the forward limit (FIG. 2), the rear end of the advancing / retreating member 33 does not protrude rearward (toward the fixed die plate 21 in this case) from the die (the fixed die 103 in this case). More specifically, in the illustrated example, the rear end face of the advancing / retreating member 33 and the back face (reference numeral omitted) of the fixed die 103 are roughly flush with each other. This reduces the likelihood that the advancing / retreating member 33 will interfere with the fixed die plate 21, for example, when attaching the die 101 to the die casting machine 1, by positioning the advancing / retreating member 33 at the forward limit.

[0052] (3. Drive unit of the transformer (pressure cylinder)) (3.1. Drive unit in general) The drive unit (pressure cylinder 35 in the illustrated example) has a fixed member (cylinder member 37 in the illustrated example) and a movable member (piston member 39 in the illustrated example). The fixed member is, for example, a member that is fixed directly or indirectly to the fixed mold 103 or the movable mold 105. The movable member is a member that is movable relative to the fixed member and that directly or indirectly pushes the rear end of the advancing / retreating member 33. As already mentioned, the drive unit generates a driving force that moves the movable member relative to the fixed member by hydraulic, pneumatic, or electric means, or a combination of these. As long as these requirements are met, the configuration of the drive unit is arbitrary and may be variously configured.

[0053] For example, the driving unit may be a hydraulic cylinder (e.g., a hydraulic cylinder), a pneumatic cylinder, or an electric motor. The gas used in the pneumatic cylinder is not limited to air, and may be other gases (e.g., an inert gas). The electric motor may be a linear motor or a rotary motor. In an embodiment in which the electric motor is a rotary motor, the driving unit may be defined to include a mechanism that converts rotary motion into linear motion. In other embodiments, the driving unit may also include a mechanism that transmits motion.

[0054] When a hydraulic cylinder or a pneumatic cylinder is used, either the cylinder member or the piston member may be the fixed member or the movable member. When an electric motor is used, either the armature or the field magnet may be the fixed member or the movable member. The drive unit may directly push the rear end of the advancing / retreating member 33, or may indirectly push the advancing / retreating member 33 via another member. Examples of the other member include a shaft-shaped or block-shaped member that is not connected to either the advancing / retreating member 33 or the movable member, and an elastic member.

[0055] The forward and backward limits of the movable member may be determined by engagement with the fixed member (contact in the forward direction) or by engagement with another member (for example, the fixed die plate 21 or the fixed die 103). The forward limit of the movable member may also be determined by the forward limit of the advancing / retracting member 33.

[0056] One drive unit may, for example, drive one advancing / retreating member 33. Alternatively, one drive unit may drive multiple advancing / retreating members 33 via a plate-like member or the like, just as one drive unit drives multiple extrusion pins in a known extrusion device. In an embodiment in which multiple drive units are provided, there may be a drive unit that is not used and does not have an advancing / retreating member 33 arranged therein.

[0057] (3.2. Drive unit in the illustrated example) 2 is the pressure cylinder 35, as already described. The pressure cylinder 35 has a cylinder member 37 and a piston member 39 (piston 41 and rod 43), and it has already been described that the piston member 39 (rod 43) presses (directly) the rear end of the advancing / retreating member 33. The advancing / retreating member 33 and the pressure cylinder 35 are, for example, positioned coaxially with each other. The piston 41 may have a packing (reference number omitted).

[0058] In the illustrated example, the pressure cylinder 35 is built into the fixed die plate 21. From another perspective, the cylinder member 37 is fixed to a die plate (here, the fixed die plate 21) that holds a die (here, the fixed die 103) without (more specifically, directly) via the fixed die 103. In the description of the embodiment, for convenience, unless otherwise specified, the term "fixed die plate 21" may include the pressure cylinder 35 in some cases, or may not include part or all of the pressure cylinder 35 in some cases.

[0059] In addition, in this disclosure, the term "fixed" may be broadly interpreted. For example, the fixation of the cylinder member 37 and the die plate (e.g., the fixed die plate 21) includes not only a state in which they are detachably connected by screws (bolts) or the like, but also a state in which they are inseparably joined, and a state in which they are (at least partially) integrally formed.

[0060] In FIG. 2, for convenience, the cylinder member 37 and the fixed die plate 21 are hatched identically as if they were integrally formed. However, in reality, they may be formed by combining multiple members. For example, the front end surface or the rear end surface of the cylinder member 37 may be formed by a member different from the fixed die plate 21. This may allow the piston 41 to be sealed inside the cylinder member 37. Furthermore, a pressure cylinder 35, whose entire structure is formed by multiple members separate from the fixed die plate 21, may be attached to the fixed die plate 21.

[0061] Furthermore, the cylinder member 37 may be entirely located inside the fixed die plate 21 (as in the illustrated example), or may be partially located outside the fixed die plate 21. An example of the latter is a mode in which the rear end of the cylinder member 37 protrudes rearward from the rear surface of the fixed die plate 21 (the surface opposite to the fixed die 103).

[0062] In the illustrated example, when the piston member 39 is positioned at the forward limit relative to the cylinder member 37, the tip of the piston member 39 does not protrude from the mounting surface 21a of the fixed die plate 21. More specifically, in the illustrated example, the front end surface of the piston member 39 and the mounting surface 21a are roughly flush with each other. This reduces the likelihood that the piston member 39 will interfere with the die 101, for example, when attaching the die 101 to the die casting machine 1, regardless of the position of the piston member 39.

[0063] As described above, in the illustrated example, when the advancing / retreating member 33 is located at the forward limit determined by the fixed mold 103, its rear end is approximately flush with the back surface of the fixed mold 103. The back surface and the mounting surface 21a abut against each other. Therefore, in the illustrated example, when the piston member 39 is located approximately at the forward limit, the advancing / retreating member 33 is also located approximately at the forward limit. Also, as described above, the backward limit of the retracting member 33 is determined by the backward limit of the piston member 39. For these reasons, in the following explanation, for convenience, there may be cases where no distinction is made between the drive limit of the advancing / retreating member 33 and the drive limit of the piston member 39.

[0064] A recess 21r capable of receiving the rear end portion of the retracted advancing / retreating member 33 is formed in the mounting surface 21a of the fixed die plate 21. This allows the rear end surface of the retracting member 33 to abut against the front end surface of the piston member 39 that has retracted further back than the mounting surface 21a. Consequently, it becomes possible for the piston member 39 to (directly) push the retracting member 33. Note that, for example, if another member is interposed between the retracting member 33 and the piston member 39 or if the front end surface of the piston member 39 protrudes forward beyond the mounting surface 21a, the recess 21r is not necessary.

[0065] The interior of the cylinder member 37 is divided by the piston 41 into a rod-side chamber 37r on the side from which the rod 43 extends and a head-side chamber 37h on the opposite side. Supplying hydraulic fluid to the head-side chamber 37h (or, in other words, applying pressure) generates a driving force that moves the piston member 39 forward. Meanwhile, the rod-side chamber 37r is simply open to the atmosphere. As a result, various effects are achieved, as will be described later. The piston member 39 retracts when, for example, molten metal pushes the piston member 39 rearward via the advancing / retracting member 33. The rod-side chamber 37r may contain a small amount of hydraulic fluid for lubrication or other purposes. Unlike the present embodiment, hydraulic fluid may be supplied to the rod-side chamber 37r.

[0066] The specific configuration of the port and / or flow passage 47 connecting the head side chamber 37h to the hydraulic circuit described later and the port and / or flow passage 49 for opening the rod side chamber 37r to the atmosphere is arbitrary. For example, the flow passages 47 and / or 49 may be formed by pipes or hoses inserted into the fixed die plate 21 and connected to the cylinder member 37, or may be formed in part or in whole by through-holes formed in the fixed die plate 21 (a component constituting a major part thereof). In FIG. 2, for convenience, the fixed die plate 21 is hatched as if through-holes were formed therein (although through-holes may actually be formed therein). Furthermore, for example, the flow passage 47 does not have to be located within the fixed die plate 21. An elongated, sealed space that can be regarded as the flow passage 49 does not have to exist.

[0067] The diameter of the piston 41 and the diameter of the rod 43 may be any size, and the difference and ratio between them may also be any size. In the illustrated example, the rod side chamber 37r is simply open to the atmosphere, so in simple theory, the driving force that advances the piston member 39 is determined by the pressure and diameter of the head side chamber 37h and is not affected by the rod side chamber 37r. In other words, the difference or ratio between the diameters of the piston 41 and the rod 43 does not affect the operation of the pressurizing cylinder 35. The diameter of the rod 43 may be smaller (in the illustrated example), equal to, or larger than the diameter of the advancing / retracting member 33 (e.g., the sliding portion 33a and / or the rear end). The diameter of the piston 41 may be larger than the diameter of the advancing / retracting member 33 (sliding portion 33a), for example.

[0068] (3.3. Position Sensor) As shown in FIGS. 2 to 5, the pressure transformer 31 may have a position sensor 75 that detects the position of the piston member 39. The detection result of the position sensor 75 may be used as appropriate. For example, by detecting the retreat of the piston member 39 (advancing / retracting member 33), it can be detected that the molten metal has been filled up to the position of the advancing / retracting member 33. Then, the detection of this retreat may be used as a trigger to start local pressurization. Furthermore, for example, when local pressurization is performed, the advance distance (e.g., the final protrusion amount of the advancing / retracting member 33) and / or speed of the piston member 39 may be controlled based on the detection value of the position sensor 75.

[0069] The position sensor 75 can have a variety of configurations. In the illustrated example, the position sensor 75 is configured by a linear encoder. Specifically, the position sensor 75 has a scale 75a and a head 75b that outputs a pulse signal in response to relative movement of the scale 75a. The scale 75a is fixed to the piston member 39. The head 75b is fixed to the fixed die plate 21. The linear encoder may be, for example, a magnetic or optical type, and may be an absolute or incremental type.

[0070] As an example of a configuration of the position sensor 75 other than the illustrated example, for example, a mode using a rod-shaped member fixed to the piston member 39 and extending rearward from the cylinder member 37 can be mentioned. A head 75b may be provided on this rod-shaped member, and a scale 75a may be fixed to the fixed die plate 21. Also, the position of the rod-shaped member may be detected by a laser length measuring device. A scale 75a integrated with the rod 43 may also be used.

[0071] Note that other sensors may be provided instead of or in addition to the position sensor 75. For example, a position sensor that directly detects the position of the advancing / retreating member 33 may be provided. On the premise that the pressurizing cylinder 35 is used at its full stroke, a limit switch (which may be regarded as a type of position sensor) that detects that the advancing / retreating member 33 or the piston member 39 has reached its retraction limit may be provided. The behavior of the piston member 39 may be grasped by a sensor that detects the pressure or flow rate related to the head side chamber 37h.

[0072] (4. Hydraulic system of transformer) 6 to 8 are diagrams showing the configuration of the hydraulic system of the pressure transformer 31. As will be described later, Fig. 6 to Fig. 8 show different states. In these figures, flow paths to which relatively high pressure is applied are shown with thicker lines than the other flow paths.

[0073] The pressure transformer device 31 includes, for example, an accumulator 51 capable of accumulating pressure, a hydraulic pressure source (a pump 53 in the illustrated example) capable of delivering hydraulic fluid, and a hydraulic circuit 55 that controls the flow of hydraulic fluid. The hydraulic circuit 55 includes a flow path that interconnects the pressurizing cylinder 35 (more specifically, the head-side chamber 37h), the accumulator 51, and the pump 53, and controls the flow of hydraulic fluid among these three elements.

[0074] Generally speaking, the hydraulic system of the transformer device 31 (excluding the pressure cylinder 35) can be considered to have the following three components. Configuration related to the flow of hydraulic fluid from the head side chamber 37h to the accumulator 51: For example, when the advancing / retreating member 33 and the piston member 39 are retracted due to the pressure of the molten metal, the hydraulic fluid discharged from the head side chamber 37h is caused to flow to the accumulator 51, thereby contributing to the absorption of surge pressure. Configuration relating to the flow of hydraulic fluid from the pump 53 to the head side chamber 37h: For example, supplying hydraulic fluid from the pump 53 to the head side chamber 37h advances the piston member 39 and the advancing / retracting member 33, thereby contributing to local pressurization. Other configurations These configurations will be explained in order below.

[0075] (4.1. Configuration from pressure cylinder to accumulator) The accumulator 51 is connected to the head side chamber 37h via an ACC flow path 57A. An ACC valve 59 is located in the ACC flow path 57A. The ACC valve 59 is closed, for example, when hydraulic fluid is supplied from the pump 53 to the head side chamber 37h to move the piston member 39 forward, thereby contributing to reducing the likelihood that hydraulic fluid from the pump 53 will flow into the accumulator 51. In the illustrated example, the ACC valve 59 is a pilot-type valve. The introduction of pilot pressure is controlled by a pilot valve 61. The specific configuration of each component is, for example, as follows:

[0076] The accumulator 51 may be of various types, such as a weight type, a spring type, a gas pressure type, a piston type, or a bladder type. In a weight type, pressure is applied to the hydraulic fluid by the gravity of a weight. In a spring type, pressure is applied to the hydraulic fluid by the restoring force of a spring. In a gas pressure type, compressed gas applies pressure to the hydraulic fluid by directly contacting the hydraulic fluid. In a piston type, compressed gas applies pressure to the hydraulic fluid via a piston. In a bladder type, compressed gas applies pressure to the hydraulic fluid via a flexible bladder (diaphragm). In the gas pressure, piston, and bladder types, the gas is, for example, air or an inert gas (e.g., nitrogen).

[0077] In FIG. 6, a piston-type accumulator is shown as an example of the accumulator 51. Although not specifically designated by a reference numeral, the accumulator 51 has a cylinder member and a piston housed in the cylinder member. The interior of the cylinder member is partitioned into a liquid chamber that houses a liquid and a gas chamber that houses a gas. The accumulator 51 applies pressure to the working fluid in the liquid chamber by the pressure of the compressed gas (e.g., nitrogen or air) in the gas chamber. The liquid chamber is connected to the ACC flow path 57A.

[0078] The ACC valve 59 may have various configurations as long as it is possible to prohibit flow from the head-side chamber 37h side to the accumulator 51 side. In the illustrated example, the ACC valve 59 is configured as a logic valve controlled by the pressure (pilot pressure) introduced from the pilot flow path 57C.

[0079] Specifically, in the illustrated example of the ACC valve 59, a spring (reference numeral omitted) applies a restoring force to the valve element (reference numeral omitted) toward the closed position (a position that closes the ACC valve 59). Both the pressure in the ACC flow path 57A (or, from another perspective, the head-side chamber 37h) and the pressure in the accumulator 51 act as forces that move the valve element toward the open position. Therefore, when pilot pressure is not being introduced, the ACC valve 59 is opened when the sum of the forces that the pressure in the ACC flow path 57A and the pressure in the accumulator 51 apply to the valve element toward the open position (when the force due to one pressure is zero, the force due to the other pressure) exceeds the restoring force. On the other hand, when pilot pressure is being introduced, the sum of the force that the pilot pressure applies to the valve element toward the closed position and the restoring force exceeds the force applied to the valve element toward the open position, thereby closing the ACC valve 59.

[0080] Examples of configurations of the ACC valve 59 other than the illustrated example include a check valve, a switching valve, a flow control valve, and a solenoid valve. The relationship between the introduction of pilot pressure and the opening and closing of the ACC valve 59 may be reversed from that in the illustrated example.

[0081] The pilot valve 61 is located in the pilot flow path 57C and controls the introduction and stopping of pilot pressure to the ACC valve 59. More specifically, the ACC valve 59 selectively connects the pilot port of the ACC valve 59 (the port through which the pilot pressure is introduced) to the pump 53 and the tank 63. Various configurations are possible, and FIG. 6 illustrates a four-port, two-position selector valve. However, one of the four ports is blocked and unused. In the rectangular state (position) on the left side of the figure, the pilot valve 61 connects the pilot port of the ACC valve 59 to the tank 63. This stops the introduction of pilot pressure to the ACC valve 59. In addition, in the rectangular state (position) on the right side of the figure, the pilot valve 61 connects the pilot port of the ACC valve 59 to the pump 53. This allows pilot pressure to be introduced to the ACC valve 59. The driving method of the pilot valve 61 is arbitrary, and FIG. 6 shows an example of a method that combines a spring that puts the pilot valve 61 into the rectangular state on the left side of the figure with a solenoid that puts the pilot valve 61 into the rectangular state on the right side of the figure.

[0082] In response to the provision of a plurality of pressurizing cylinders 35, the ACC flow path 57A branches off closer to the pressurizing cylinder 35 than the ACC valve 59. Note that, in the case where a plurality of pressurizing cylinders 35 are provided, unlike the example shown in the drawing, one accumulator 51 may be provided corresponding to each pressurizing cylinder 35. Furthermore, as in the example shown in the drawing, a configuration in which a plurality of pressurizing cylinders 35 are connected to one accumulator 51 may be provided in multiple places.

[0083] The ACC flow path 57A, for example, has only the ACC valve 59 as a valve controlled by the controller 5 between the head side chamber 37h and the accumulator 51, and does not have any other valves. Note that the ACC flow path 57A may or may not have a valve that is not controlled by the controller 5 (for example, a manual valve). Also, for example, in the ACC flow path 57A, the minimum cross-sectional area of ​​the portion other than the ACC valve 59 (the sum of the minimum areas if there is a branch) is larger than the minimum cross-sectional area within the ACC valve 59. With this configuration, the ACC flow path 57A has a small pressure loss.

[0084] The various flow paths (including flow paths other than the ACC flow path 57A) of the hydraulic circuit 55 may be configured as appropriate. For example, each flow path may be configured by a rigid pipe, a flexible hose, a block in which a flow path is formed, and / or a combination thereof.

[0085] (4.2. Configuration from pump to cylinder) The pump 53 is connected to the head-side chamber 37h via a pump flow path 57B (an example of a hydraulic pressure source flow path). In the pump flow path 57B, a check valve 65 and a supply valve 67 are positioned in this order from the pump 53 side. The specific configuration of each element is as follows, for example.

[0086] The pump 53 may or may not be shared by devices other than the transformer device 31 of the die casting machine 1 (for example, the hydraulic system of the injection device 9). The pump 53 may be shared by a plurality of die casting machines 1. The pump 53 may have various configurations, for example, a known configuration. The pump 53 may be driven as needed, or may be driven constantly. The pump 53 is, for example, capable of arbitrarily adjusting the pressure it supplies. The adjustment may be achieved, for example, by controlling the rotation speed of an electric motor 69 that drives the pump 53. The electric motor 69 may be, for example, an AC servo motor or may be inverter-controlled.

[0087] The pump flow path 57B shares a portion of the head side chamber 37h side with the ACC flow path 57A. From another perspective, the pump 53 is connected not only to the head side chamber 37h but also to the accumulator 51, and can accumulate pressure in the accumulator 51. In addition, the pump flow path 57B shares a portion of the pump 53 side with the pilot flow path 57C.

[0088] The check valve 65 contributes to reducing the likelihood of hydraulic fluid flowing back into the pump 53. The check valve 65 allows flow from the pump 53 to the head side chamber 37h and prohibits flow in the opposite direction. The check valve 65 is located in a portion shared by the pump flow path 57B and the pilot flow path 57C.

[0089] Of the hydraulic system of the transformer device 31, the portion on the head side chamber 37h and accumulator 51 side of the supply valve 67 will be referred to as the "partial circuit 71." The partial circuit 71 includes the head side chamber 37h and the accumulator 51. In addition, in explanations of the operation of the supply valve 67, the term "partial circuit 71" may be replaced with the term "head side chamber 37h" or "accumulator 51" as long as no contradictions arise.

[0090] The supply valve 67 serves to selectively connect the partial circuit 71 to the pump 53 and the tank 63. This allows, for example, switching between supplying hydraulic fluid to the partial circuit 71 and discharging hydraulic fluid from the partial circuit 71. The supply valve 67 can have various configurations, and FIG. 6 illustrates a four-port, two-position selector valve. However, one of the four ports is blocked and unused. In the rectangular state (position) on the left side of the figure, the supply valve 67 connects the pump 53 and the partial circuit 71. In the rectangular state (position) on the right side of the figure, the supply valve 67 connects the tank 63 and the partial circuit 71. The supply valve 67 can be driven by any method, and FIG. 6 illustrates a method that combines a spring that sets the supply valve 67 to the rectangular state on the right side of the figure with a solenoid that sets the supply valve 67 to the rectangular state on the left side of the figure.

[0091] (4.3. Other configurations of the hydraulic system) The tank 63 already mentioned may or may not be shared with hydraulic systems other than the transformer device 31 of the die casting machine 1 (for example, the hydraulic system of the injection device 9). The tank 63 may be shared by a plurality of die casting machines 1. The tank 63 may have various configurations, for example, a known configuration. The tank 63 is, for example, of an atmospherically open type. In other words, the tank pressure is approximately atmospheric pressure. Therefore, the pressure in the flow paths, etc. connected to the tank 63 is theoretically approximately atmospheric pressure.

[0092] The pressure transformer device 31 may have a pressure sensor 73 that detects the pressure in the head side chamber 37h. This pressure sensor 73 is referenced, for example, when adjusting the pressure in the head side chamber 37h when absorbing surge pressure or when adjusting the pressure in the head side chamber 37h when applying local pressure. In other words, the pressure sensor 73 is used for pressure feedback control. The pressure sensor 73 may detect the pressure at any position as long as it can substantially detect the pressure in the head side chamber 37h. In the illustrated example, the pressure sensor 73 detects the pressure in a portion of the ACC flow path 57A that is closer to the head side chamber 37h than the ACC valve 59. The configuration of the pressure sensor 73 is also arbitrary.

[0093] (5. Operation of the transformer) The die-casting machine 1 repeats, for example, molding cycles. In each molding cycle, the pressure transformer 31 performs the following operations in order: waiting for the molten metal to be filled (FIGS. 3 and 6), absorbing surge pressure (FIGS. 4 and 7), applying local pressure (FIGS. 5 and 8), and preparing for the next cycle. Specifically, these operations are as follows:

[0094] (5.1. Standby operation) During the standby operation (FIGS. 3 and 6) waiting for the filling of molten metal, the controller 5 controls the hydraulic circuit 55 (from another perspective, the ACC valve 59) to allow flow from the head side chamber 37h to the accumulator 51. Specifically, the controller 5 sets the pilot valve 61 to the rectangular state on the left side of the figure, and stops the introduction of pilot pressure to the ACC valve 59.

[0095] Furthermore, during standby operation, the pressure in the head-side chamber 37h (partial circuit 71 from another perspective) is adjusted to a predetermined target pressure (first pressure). Specifically, the controller 5 controls the hydraulic circuit 55 (supply valve 67 in another sense) to allow the flow of hydraulic fluid from the pump 53 to the head-side chamber 37h. The controller 5 also controls the electric motor 69 so that the discharge pressure of the pump 53 becomes a predetermined pressure. At this time, feedback control based on the detection value of the pressure sensor 73 may be performed.

[0096] As a result of the above control, the piston member 39 and the advancing / retreating member 33 are stopped at the forward limit. The pressure of the accumulator 51 is balanced with the pressure of the pump 53. At this time, the piston of the accumulator 51 may be located near the drive limit on the liquid chamber side, or may be located a certain distance away from the drive limit on the gas chamber side. However, unlike the description here, the accumulator 51 may have a value obtained by converting the pressure of the gas chamber into the pressure of the liquid chamber (hereinafter sometimes referred to as the "converted pressure") higher than the pressure of the pump 53 (first pressure), and the piston may be located at the drive limit on the liquid chamber side.

[0097] The specific value of the target pressure (first pressure) of the head side chamber 37h is arbitrary as long as it is equal to or less than the magnitude at which the force of the molten metal ML pushing the advancing / retracting member 33 can move backward when a surge pressure of a predetermined magnitude occurs. For example, the target pressure may be less than 1 MPa or may be equal to or greater than 1 MPa. As an example, the target pressure may be adjusted in 0.1 MPa increments within a range of 1 MPa to 5 MPa. The predetermined magnitude of the surge pressure may be determined by any of the manufacturer of the pressure transformer 31, the operator, and the controller 5. Similarly, the target pressure may be set by any of the manufacturer of the pressure transformer 31, the operator, and the controller 5.

[0098] (5.2. Absorption of surge pressure) When the injection device 9 injects the molten metal ML into the space 107, the molten metal ML reaches the advancing / retreating member 33. Then, as shown in Figures 4 and 7, when the force with which the molten metal ML pushes the advancing / retreating member 33 backward exceeds the force with which the pressure cylinder 35 pushes the advancing / retreating member 33 forward, the advancing / retreating member 33 moves backward. Then, the surge pressure is absorbed.

[0099] At this time, a flow occurs from the head-side chamber 37h to the accumulator 51, and the hydraulic fluid flows into the accumulator 51. As a result, the pressure in the accumulator 51 increases. That is, the force with which the pressurizing cylinder 35 pushes the advancing / retracting member 33 forward increases. When this increased force balances with the force with which the molten metal pushes the advancing / retracting member 33 backward, the advancing / retracting member 33 stops. Alternatively, the advancing / retracting member 33 (piston member 39) stops when it reaches its rearward limit. Note that, unlike the description here, the advancing / retracting member 33 may stop when the piston of the accumulator 51 reaches its upper limit (the drive limit on the gas chamber side). Furthermore, as will be understood from the description of the operation related to local pressurization below, the advancing / retracting member 33 may start moving forward (local pressurization) before naturally stopping as described above.

[0100] (5.3. Local pressure) 5 and 8, the controller 5 controls each component so that the advancing / retracting member 33 is advanced at an appropriate time after the advancing / retracting member 33 starts to retract, thereby applying local pressure. Specifically, for example, the controller 5 controls the ACC valve 59 so as to prohibit flow from the head-side chamber 37h to the accumulator 51. That is, the controller 5 sets the pilot valve 61 to the state shown on the right side in the drawing. The controller 5 also controls the pump 53 (electric motor 69) so that a pressure (second pressure) higher than the pressure immediately after absorbing the surge pressure is applied to the pressurizing cylinder 35.

[0101] When advancing the advancing / retreating member 33, feedback control based on the pressure sensor 73 may be performed. The target value of the pressure that the advancing / retreating member 33 applies to the molten metal ML may be a constant value, or may be set so that the pressure increases along a predetermined pressure curve (a curve drawn on a graph with the horizontal axis representing time and the vertical axis representing pressure). Also, unlike the description here, the position of the advancing / retreating member 33 may be controlled based on the detection value of the position sensor 75.

[0102] After localized pressurization begins, the advancing / retreating member 33 stops at a position where, for example, the force with which the pressure cylinder 35 pushes the advancing / retreating member 33 forward is balanced with the force with which the molten metal pushes the advancing / retreating member 33 backward. As a result, the advancing / retreating member 33 applies to the molten metal a pressure determined by the pressure applied to the pressure cylinder 35. However, unlike the explanation given here, the advancing / retreating member 33 may reach its forward limit before the above-mentioned balance is achieved.

[0103] The pressure that the reciprocating member 33 ultimately applies to the molten metal is arbitrary. For example, this pressure may be lower, equal to, or higher than the pressure that the injection device 9 ultimately applies to the molten metal. Note that, as the molten metal solidifies, Pascal's principle no longer strictly holds for the molten metal. Therefore, for example, even if the pressure of the local pressurization is higher than the pressure that the injection device 9 applies to the molten metal, the plunger (reference number omitted) of the injection device 9 will not retract as long as the difference is not too large.

[0104] In addition, the target value (second pressure) of the pressure applied by the pump 53 to the pressurizing cylinder 35 may also be set appropriately. As an example, the target value of the pressure may be set and changed in increments of 0.1 MPa within a range of 16 MPa or less.

[0105] The timing at which the controller 5 starts local pressurization may be, for example, when an appropriate condition is satisfied, or when a predetermined time has elapsed since the above condition is satisfied. In other words, the timing at which local pressurization starts may be determined based on an appropriate condition.

[0106] The above condition may be, for example, that the position sensor 75 has detected the retreat of the advancing / retreating member 33. The detection of the retreat here may be the detection of whether the advancing / retreating member 33 has retreated or not, or the detection of the amount of retreat of the advancing / retreating member 33 having reached a predetermined amount, or the detection of the advancing / retreating member 33 having retreated to a predetermined position. Note that if the amount of retreat is relatively small, or if the predetermined position is relatively close to the advance limit, it may be considered that the presence or absence of the retreat of the advancing / retreating member 33 has been detected.

[0107] The retreat of the advancing / retreating member 33 may be detected by a sensor other than the position sensor 75. For example, since the pressure in the head side chamber 37h etc. increases when the advancing / retreating member 33 retreats, the pressure sensor 73 may be used to detect the retreat. The condition that triggers the start of local pressurization may be something other than the detection of the retreat of the advancing / retreating member 33. For example, the condition may be the passage of a predetermined time from the start of injection by the injection device 9. Furthermore, for example, the arrival of the molten metal at a predetermined position may be detected by a method other than the detection of the retreat of the advancing / retreating member 33 (for example, an electrical conductivity sensor, a temperature sensor, or a pressure sensor).

[0108] (5.4. Preparation for the next cycle) The controller 5 may start preparation for the next cycle at an appropriate time. This time may be, for example, after the molten metal has solidified but before mold opening, or after mold opening (or during mold opening). In the latter case, for example, the molded product may be pushed by the advancing / retracting member 33 at a relatively high pressure to separate the molded product from the fixed mold 103. The pressure in the head-side chamber 37h at this time may be, for example, the same as the pressure (second pressure) during local pressurization, or it may be higher or lower than that pressure. The controller 5 may determine whether the molten metal has solidified as appropriate. For example, solidification of the molten metal may be determined based on whether a predetermined time has elapsed since an appropriate time point (for example, the start of injection or the start of local pressurization).

[0109] In preparation for the next cycle, first, the controller 5 controls the hydraulic circuit 55 to connect the partial circuit 71 (from another perspective, the head side chamber 37h and the accumulator 51) to the tank 63. This causes the partial circuit 71 to be depressurized, and the pressure that has been set to the second pressure by local pressurization is reduced to a pressure equal to or lower than the first pressure for standby operation.

[0110] Specifically, the controller 5 sets the supply valve 67 to the state shown by the rectangle on the right side of the figure. Also, the controller 5 stops the introduction of pilot pressure to the ACC valve 59. That is, the controller 5 sets the pilot valve 61 to the state shown by the rectangle on the left side of the figure. Note that the pump 53 may be stopped (or may be driven), for example.

[0111] Thereafter, the controller 5 controls each part as described in the description of the standby operation. Immediately before starting the standby operation, the pressure in the partial circuit 71 may be reduced to the tank pressure or may be an appropriate pressure equal to or lower than the first pressure.

[0112] (6. Other examples of transformers) 9(a) and 9(b) are cross-sectional views showing other examples of transformer devices. In the following description, matters not specifically mentioned may be considered to be the same as those of transformer device 31 or may be inferred from the description of transformer device 31. For convenience, the same reference numerals may be used for components corresponding to those of transformer device 31, even if there are differences between the two.

[0113] The transformer device 31A shown in Figure 9(a) differs from the transformer device 31 in that the pressure cylinder 35 is not fixed directly to the fixed die plate 21, but is fixed directly to the fixed mold 103. More specifically, the pressure cylinder 35 is built into the fixed mold 103. For convenience, the cylinder member 37 and the fixed mold 103 are shown with the same hatching, but in reality, the cylinder member 37 may be made up of multiple members.

[0114] 9(b) is different from the pressure transformer 31 in that the pressurizing cylinder 35B does not have a rod-side chamber 37r. Specifically, the piston member 39B does not define the interior of the cylinder member 37B, and only a head-side chamber 37h is defined. The piston member 39B may slide in a through-hole at the front end of the cylinder member 37B (as shown in the example), or may slide on the inner circumferential surface of the cylinder member 37B (the outer diameter of the piston member 39B may be the same as the inner diameter of the cylinder member 37B).

[0115] (7. Summary of embodiments) As described above, the local transformer device 31 (or 31A or 31B; hereinafter, only the reference numeral for the transformer device 31 will be used) according to this embodiment has a drive unit (pressurizing cylinder 35) that advances the advancing / retreating member 33. The advancing / retreating member 33 can advance into the space 107 defined by the mold (fixed mold 103) and retreat to the opposite side with its tip exposed in the space 107. The pressurizing cylinder 35 has a fixed member (cylinder member 37) and a movable member (piston member 39). A driving force is applied to the piston member 39 to move relative to the cylinder member 37, thereby pushing (directly or indirectly) the rear end of the advancing / retreating member 33. Furthermore, the piston member 39 is not connected to any member exposed in the space 107, including the advancing / retreating member 33, and is therefore movable relative to the rear end of the advancing / retreating member 33 in directions away from each other.

[0116] The molding machine (die-casting machine 1) according to the embodiment includes the local transformer device 31 according to the embodiment described above, a mold clamping device 7, and an injection device 9. The mold clamping device 7 opens and closes a pair of molds (metal dies 101) including the above-described molds as a fixed mold 103 or a movable mold 105. The injection device 9 injects a molding material (molten metal ML) into a space 107.

[0117] Therefore, for example, as described in the description of the outline of the embodiment, there is no need to provide a connecting mechanism, which simplifies the configuration of the transformer device 31 and the mold 101. As a result, for example, the costs of the transformer device 31 and the mold 101 can be reduced.

[0118] The fixed member (cylinder member 37) may be fixed to the die plate (fixed die plate 21) that holds the die (fixed die 103) without the fixed die 103 being interposed therebetween.

[0119] In this case, in other words, it is not necessary to provide the pressure cylinder 35 in the mold 101. Therefore, for example, the cost of the mold 101 can be reduced. Furthermore, since it is not necessary to provide a pressure cylinder 35 for each mold 101, the cost related to the pressure cylinder 35 can also be reduced.

[0120] The movable member (piston member 39) may be restricted from moving beyond the forward limit toward the advancing / retreating member 33 by engaging with the fixed member (cylinder member 37). In addition, the piston member 39 may be configured not to protrude from the surface (mounting surface 21a) of the die plate (fixed die plate 21) to which the die (fixed die 103) is attached toward the fixed die 103 when positioned at the forward limit.

[0121] In this case, for example, when replacing the die 101, the probability of interference between the die 101 and the piston member 39 is reduced. Consequently, the work of replacing the die 101 is facilitated.

[0122] The fixed member may be a cylinder member 37. The movable member (piston member 39) may have a piston 41 and a rod 43. The piston 41 may be located inside the cylinder member 37. The rod 43 may extend from the piston 41 to the outside of the cylinder member 37, and its tip may face the rear end of the advancing / retreating member 33. The inside of the cylinder member 37 may be partitioned by the piston 41 into a rod-side chamber 37r on the side from which the rod 43 extends, and a head-side chamber 37h on the opposite side. The rod-side chamber 37r may be open to the atmosphere.

[0123] In this case, for example, piping for hydraulic fluid related to the rod-side chamber 37r is not required, simplifying the configuration of the hydraulic system. Furthermore, pressure loss due to hydraulic fluid flowing through the above-described piping does not occur. Consequently, the responsiveness of the piston 41 can be improved. From another perspective, there is no need to thicken the piping to reduce pressure loss. Furthermore, focusing on local pressurization, the piston 41 is not advanced by the difference between the force due to hydraulic pressure in the rod-side chamber 37r and the force due to hydraulic pressure in the head-side chamber 37h. Therefore, even if the diameter of the head-side chamber 37h is small, a sufficient driving force can be secured. In other words, the pressurizing cylinder 35 can be made smaller. Since there is no need to thicken the piping and / or the pressurizing cylinder 35 can be made smaller, the volume of the fixed die plate 21 (or the fixed die 103) can be secured, and thus the strength can be secured.

[0124] The pressure transformer device 31 may include an accumulator, a hydraulic pressure source (pump 53), a hydraulic circuit 55, and a controller 5. The accumulator 51 may be in communication with the head-side chamber 37h. The pump 53 may be in communication with the head-side chamber 37h and may deliver hydraulic fluid. The hydraulic circuit 55 may control the flow among the head-side chamber 37h, the accumulator 51, and the pump 53. The controller 5 may control the pump 53 (or, from another perspective, the electric motor 69) and the hydraulic circuit 55. The controller 5 may control the pump 53 and the hydraulic circuit 55 to bring the head-side chamber 37h, the accumulator 51, and the pump 53 into communication with each other before the molding material (molten metal ML) injected into the space 107 reaches the advancing / retracting member 33, and to deliver hydraulic fluid from the pump 53 so that the pressure in the head-side chamber 37h reaches a predetermined first pressure, thereby causing the advancing / retracting member 33 to wait at the forward limit ( FIG. 6 ). Furthermore, the controller 5 may control the pump 53 and the hydraulic circuit 55 so that, after the molten metal ML reaches the advancing / retreating member 33 and the advancing / retreating member 33 retreats due to the pressure of the molten metal ML, the accumulator 51 is isolated from the head side chamber 37h and the pump 53, and hydraulic fluid is sent from the pump 53 so that the pressure in the head side chamber 37h becomes a second pressure higher than the first pressure, thereby performing local pressurization.

[0125] In this case, for example, a single pump 53 can provide both the first pressure for absorbing surge pressure and the second pressure for local pressurization. Therefore, the configuration is simple. In contrast to this embodiment, an accumulator for absorbing surge pressure, which accumulates pressure up to the first pressure, and an accumulator for local pressurization, which accumulates pressure up to the second pressure, are provided, and the accumulator connected to the head-side chamber 37h is switched (this other embodiment is also included in the technology according to the present disclosure). In this other embodiment, the second pressure can be quickly applied to the head-side chamber 37h.

[0126] The hydraulic circuit 55 may have an ACC flow path 57A, a hydraulic pressure source flow path (pump flow path 57B), an ACC valve 59, and a pilot valve 61. The ACC flow path 57A may extend from the head side chamber 37h to the accumulator 51. The pump flow path 57B may extend from the hydraulic pressure source (pump 53) to the head side chamber 37h, and a portion of the pump flow path 57B on the head side chamber 37h side may be shared with the ACC flow path 57A. The ACC valve 59 may be a pilot type that opens and closes a portion of the ACC flow path 57A on the accumulator 51 side relative to the portion shared with the pump flow path 57B. The pilot valve 61 may selectively connect a port (pilot port) to which pilot pressure of the ACC valve 59 is introduced to the pump 53 or the tank 63.

[0127] In this case, for example, by using a pilot-type ACC valve 59, it is possible to allow a large flow rate of hydraulic fluid to flow from the head-side chamber 37h to the accumulator 51 when absorbing surge pressure, while reliably prohibiting flow through the ACC flow path 57A when applying local pressure. In addition, the pilot pressure to the ACC valve 59 is obtained by the pump 53 that delivers hydraulic fluid to the head-side chamber 37h when applying local pressure, so the configuration of the hydraulic circuit 55 is simple.

[0128] In the above embodiment, the fixed mold 103 is an example of a mold. The metal mold 101 is an example of a pair of molds. The molten metal ML is an example of a molding material. The die-casting machine 1 is an example of a molding machine. The pressure cylinder 35 is an example of a drive unit. The cylinder member 37 is an example of a fixed member. The piston member 39 is an example of a movable member. The fixed die plate 21 is an example of a die plate. The pump 53 is an example of a hydraulic pressure source.

[0129] The present invention is not limited to the above-described exemplary embodiments, and may be implemented in various forms.

[0130] For example, the molding machine is not limited to a die-casting machine, but may be another metal molding machine, an injection molding machine for molding resin, or a machine for molding a material that is a mixture of wood powder and resin. The hydraulic pressure source may be a hydraulic cylinder driven by an electric motor.

[0131] An invention that does not require the advance / retreat member and the drive unit (e.g., a pressure cylinder) to be disconnected may be extracted from the present disclosure. For example, an invention relating to the configuration of the hydraulic circuit 55 in an aspect in which the rod-side chamber 37r is open to the atmosphere may be extracted. [Explanation of symbols]

[0132] 1...Die-casting machine (molding machine), 31...Local transformer device, 33...Advancing and retreating member, 35...Pressure cylinder (driving part), 37...Cylinder member (fixed member), 39...Piston member (movable member), 101...Mold (pair of molds), 103...Fixed mold (mold), 107...Space.

Claims

1. The mold has a drive unit that advances a retractable member that can advance into the space defined by the mold and retreat to the opposite side with the tip exposed in the space, The drive unit is A fixing member; a movable member that is given a driving force to move relative to the fixed member and pushes the rear end of the advancing / retreating member, The movable member is not connected to any member exposed to the space, including the retractable member, and is movable relative to the rear end of the retractable member in directions away from each other. Local transformer equipment.

2. The fixing member is fixed to a die plate that holds the die without interposing the die therebetween.

2. The local transformer device according to claim 1.

3. The movable member is restricted in movement toward the advancing / retreating member side beyond the forward limit by engagement with the fixed member, and when positioned at the forward limit, does not protrude toward the die from the surface of the die plate on which the die is attached.

3. The local transformer device according to claim 2.

4. the fixed member is a cylinder member, The movable member is a piston located within the cylinder member; a rod extending from the piston to the outside of the cylinder member, the tip of which faces the rear end of the reciprocating member; The interior of the cylinder member is divided by the piston into a rod-side chamber on the side from which the rod extends and a head-side chamber on the opposite side, The rod side chamber is open to the atmosphere.

2. The local transformer device according to claim 1.

5. an accumulator communicating with the head side chamber; a hydraulic pressure source communicating with the head side chamber and supplying hydraulic fluid; a hydraulic circuit that controls a flow between the head side chamber, the accumulator, and the hydraulic pressure source; a controller for controlling the hydraulic pressure source and the hydraulic pressure circuit; It has The controller before the molding material injected into the space reaches the advancing / retreating member, the head side chamber, the accumulator, and the hydraulic pressure source are communicated with each other, and hydraulic fluid is sent from the hydraulic pressure source so that the pressure in the head side chamber becomes a predetermined first pressure, thereby controlling the hydraulic pressure source and the hydraulic pressure circuit so that the advancing / retreating member waits at the forward limit; After the molding material reaches the advancing / retreating member and the advancing / retreating member is retracted by the pressure of the molding material, the hydraulic pressure source and the hydraulic circuit are controlled so that, with the accumulator disconnected from the head side chamber and the hydraulic pressure source, working fluid is sent from the hydraulic pressure source so that the pressure in the head side chamber becomes a second pressure higher than the first pressure, thereby performing local pressurization.

5. The local transformer device according to claim 4.

6. The hydraulic circuit includes: an ACC flow path extending from the head side chamber to the accumulator; a hydraulic pressure source flow path extending from the hydraulic pressure source to the head side chamber, a portion of which is shared with the ACC flow path on the head side chamber side; a pilot-type ACC valve that opens and closes a portion of the ACC flow path that is closer to the accumulator than a portion that is shared with the hydraulic pressure source flow path; a pilot valve selectively connecting a port to which a pilot pressure of the ACC valve is introduced to the hydraulic pressure source or a tank.

6. A local transformer device according to claim 5.

7. A local transformer device according to any one of claims 1 to 6; a mold clamping device that opens and closes a pair of molds including the mold as a fixed mold or a movable mold; an injection device that injects a molding material into the space; The molding machine has:

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