Die casting machine, and die casting method using a die casting machine

Abstract

This invention provides a die-casting machine that maximizes the riser effect after the gate is closed, thereby improving the internal quality of the casting. [Solution] The die-casting machine 10 consists of an injection plunger 44 for injecting and filling molten metal into a cavity 34, a clamping device 12 for clamping a movable mold 32, and a gate blockage detection parameter measuring device 27 for measuring a gate blockage detection parameter for detecting the blockage of the gate G. Furthermore, the injection plunger 44 sets the casting pressure P so that the mold opening force Y on the movable mold 32 due to the molten metal injected into the cavity 34 is less than or equal to the clamping force X of the movable mold 32 relative to the fixed mold 30, injects and fills the cavity 34 with an amount of molten metal equal to the volume of the cavity 34, and then sets the casting pressure P so that the mold opening force Y is greater than the clamping force X, injecting an amount of molten metal exceeding the volume of the cavity 34, detecting the blockage of the gate G, and after a predetermined time, further lowers or sets the casting pressure P to zero.

Description

Technical Field

[0001] The present invention relates to a die-casting machine that injects molten metal into a mold to cast a casting, and a die-casting method using the die-casting machine.

Background Art

[0002] In a conventionally used die-casting machine, molten metal such as an aluminum alloy melted in a melting furnace is measured and lifted by a ladle for each shot, the lifted molten metal is supplied to the water inlet of an injection sleeve, and the molten metal is injected and filled into the cavity of the mold by the forward movement of an injection plunger provided to be movable forward and backward in the injection sleeve, thereby casting a casting.

[0003] Generally, in the die-casting method using a die-casting machine, when the molten metal filled in the cavity is pressurized by the injection plunger, a force (mold-opening force) acts in the direction of opening the mold according to Pascal's principle. When mold opening occurs, casting defects and flash occur, so generally, the force for clamping the mold (mold-clamping force) is set larger than the mold-opening force.

[0004] As defects of castings by the die-casting method using a die-casting machine, shrinkage cavities (solidification shrinkage cavities) generated when the volume of the molten metal filled in the cavity shrinks and solidifies are known. Castings with such defects are inferior in mechanical properties. Therefore, generally, after filling, a method of reducing defects by replenishing the volume by which the molten metal has shrunk by pressurization from the injection plunger (pushing effect) is taken (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in conventional die-casting methods using die-casting machines, the molten metal is injected and filled into the cavity at high speed. As a result, the gate, which is the inlet to the cavity, is quite narrow and thin, causing the metal to solidify immediately after filling. Consequently, the supply of molten metal to compensate for the volume contraction due to pressure from the injection plunger is interrupted, resulting in the problem of not being able to obtain a sufficient riser effect.

[0007] This invention has been made in view of the above problems, and its purpose is to provide a die-casting machine and a die-casting method using a die-casting machine that can obtain a riser effect even after solidification has progressed and the gate has closed, and furthermore, can improve the internal quality of the casting by maximizing this riser effect. [Means for solving the problem]

[0008] According to one aspect of the present invention, A mold consisting of a fixed mold and a movable mold, The cavity formed inside the mold, An injection plunger for injecting and filling the cavity with molten metal, A clamping device that opens and closes the movable mold relative to the fixed mold and clamps it, It includes a gate blockage detection parameter measuring device that measures gate blockage detection parameters capable of detecting when gate blockage has begun, The injection plunger is, The casting pressure is set such that the clamping force of the movable mold relative to the fixed mold by the clamping device is equal to or less than the opening force of the movable mold caused by the molten metal injected into the cavity, and an amount of molten metal equal to the volume of the cavity is injected and filled. Thereafter, the casting pressure is set such that the mold opening force is greater than the mold clamping force, and an amount of molten metal exceeding the volume of the cavity is injected and filled. After the gate closure detection parameter measuring device detects that the gate has begun to close, the casting pressure is reduced to a lower level or reduced to zero after a predetermined time has elapsed. A die-casting machine will be provided.

[0009] Preferably, The gate blockage detection parameter is the clamping force, The casting pressure is reduced to a lower or zero amount after a predetermined time has elapsed since the start of the reduction in the clamping force.

[0010] According to another aspect of the present invention, A mold consisting of a fixed mold and a movable mold, The cavity formed inside the mold, An injection plunger for injecting and filling the cavity with molten metal, A clamping device that opens and closes the movable mold relative to the fixed mold and clamps it, A die-casting method using a die-casting machine equipped with a gate blockage detection parameter measuring device that measures a gate blockage detection parameter capable of detecting when gate blockage has begun, In the injection plunger, The casting pressure is set such that the clamping force applied to the movable mold by the clamping device is equal to or less than the opening force applied to the movable mold by the molten metal injected into the cavity, and an amount of molten metal equal to the volume of the cavity is injected and filled, and thereafter, The casting pressure is set such that the mold opening force is greater than the clamping force, and an amount of molten metal exceeding the volume of the cavity is injected and filled. After the gate closure detection parameter measuring device detects that the gate has begun to close, the casting pressure is reduced to a lower level or reduced to zero after a predetermined time has elapsed. A die-casting method using a die-casting machine is provided.

[0011] Preferably, The gate blockage detection parameter is the clamping force, After a predetermined time has elapsed since the reduction of the clamping force started, lower the casting pressure or set it to zero.

Advantages of the Invention

[0012] According to the die-casting machine and the die-casting method using the die-casting machine of the present invention, even after solidification progresses and the gate closes, a pushing hot water effect can be obtained. Furthermore, by making the casting pressure by the injection plunger lower or zero, the internal quality of the cast product can be improved by maximizing this pushing hot water effect.

Brief Description of the Drawings

[0013] [Figure 1] It is a diagram showing an example of the die-casting machine 10 according to the embodiment. [Figure 2] It is a graph showing changes in the casting pressure P (P'), the in-mold pressure Q, the clamping force X (X'), the mold opening force Y, and the compression force Z in the casting process using the die-casting machine 10. [Figure 3] It is a diagram showing the state of the mold 28 and the molten metal in the casting process using the die-casting machine 10, showing the state where the molten metal is injected and filled into the cavity. [Figure 4] It is a diagram showing the state of the mold 28 and the molten metal in the casting process using the die-casting machine 10, showing the state where the movable mold 32 is separated from the fixed mold 30. [Figure 5] It is a diagram showing the state of the mold 28 and the molten metal in the casting process using the die-casting machine 10, showing the state where the movable mold 32 is separated from the fixed mold 30 and the gate is closed. [Figure 6] It is a diagram showing the state of the mold 28 and the molten metal in the casting process using the die-casting machine 10, showing the state where the casting pressure P by the injection plunger 44 is made lower or zero. [Figure 7] It is a diagram showing the state of the mold 28 and the molten metal in the casting process using the die-casting machine 10, showing the state where the gap between the movable mold 32 and the fixed mold 30 has changed and the solidification of the molten metal is complete.

Embodiment for Carrying out the Invention

[0014] (Configuration of Die Casting Machine 10) As shown in FIG. 1, the die casting machine 10 according to the present embodiment generally includes a clamping device 12, an injection device 14, and a control device 15.

[0015] The clamping device 12 includes a machine base 16, a fixed platen 18, a movable platen 20, a tailstock 22, tie bars 24, a toggle mechanism 26, and a clamping force measuring device 27.

[0016] The machine base 16 is a member that constitutes the clamping device 12 and is a base member for the injection device 14.

[0017] The fixed platen 18 is fixed on the machine base 16, and the fixed die 30 that constitutes the mold 28 is attached thereto.

[0018] The movable platen 20 is a member that slides on the machine base 16 so as to approach and separate from the fixed platen 18, and the movable die 32 that constitutes the mold 28 is attached thereto. When the movable die 32 contacts the fixed die 30, a cavity 34 into which molten metal is filled is formed.

[0019] The tailstock 22 is a member placed on the machine base 16 on the side opposite to the fixed platen 18 as viewed from the movable platen 20.

[0020] The tie bar 24 is a round bar-shaped member whose one end is fixed to the fixed platen 18 and the other end is fixed to the tailstock 22. Further, the tie bar 24 is inserted into a tie bar insertion hole 36 formed in the movable platen 20 disposed between the fixed platen 18 and the tailstock 22. Thereby, the movable platen 20 can slide along the tie bar 24 in the left-right direction in the drawing on the machine base 16. Note that a plurality of (for example, four) tie bars 24 are used.

[0021] The toggle mechanism 26 is a mechanism for moving the movable platen 20 closer to, further away from, and holding the fixed platen 18, and the clamping drive mechanism 31 is attached to the tailstock 22.

[0022] The clamping force measuring device 27 is a device for measuring the clamping force X of the movable mold 32 relative to the fixed mold 30. For example, it could be attached to a tie bar 24 and measure the clamping force X based on the amount of strain (elongation) when the tie bar 24 is extended. Of course, the measurement method is not limited as long as it is possible to measure the clamping force X of the movable mold 32 relative to the fixed mold 30.

[0023] The movable platen 20 moves along the tie bar 24 (moves left to right in the figure) as the driving force of the mold clamping drive mechanism 31 is transmitted through the toggle mechanism 26. When the movable platen 20 moves to the left, the fixed mold 30 and the movable mold 32 are separated. On the other hand, when the movable platen 20 moves to the right, the fixed mold 30 and the movable mold 32 come into contact, forming a cavity (internal space) 34 inside the mold 28. When further pressure is applied in the direction that moves the movable platen 20 to the right, the fixed mold 30 and the movable mold 32 are clamped together.

[0024] At this time, the toggle mechanism 26 gradually extends from its bent state. When the movable mold 32 comes into contact with the fixed mold 30, the tie bar 24 begins to extend, and strain proportional to the tensile stress is generated in the tie bar 24. The tension in the tie bar 24 is applied to the fixed mold 30 and the movable mold 32 as a clamping force. When the toggle mechanism 26 is fully extended, the tie bar 24 is also fully extended, and when the movable mold 32 reaches the position where the clamping is complete, a specified clamping force is applied to the fixed mold 30 and the movable mold 32.

[0025] The injection device 14 generally comprises an injection mechanism 38 and a hydraulic operating mechanism 40.

[0026] The injection mechanism 38 includes an injection sleeve 42, an injection plunger 44, an injection piston 46, and an injection cylinder 48.

[0027] The injection sleeve 42 is a cylindrical member integrally provided with the fixed platen 18, with a molten metal inlet 50 formed at its upper part.

[0028] The injection plunger 44 is a roughly rod-shaped member that is provided to move back and forth within the injection sleeve 42.

[0029] The injection piston 46 is formed on the rear end side of the injection plunger 44 (the end opposite to the end that contacts the molten metal) and is the part that is pressed by the hydraulic fluid O.

[0030] The injection cylinder 48 is a cylindrical member through which the injection piston 46 moves back and forth, and is filled with hydraulic fluid O.

[0031] The hydraulic operating mechanism 40 is a mechanism that supplies hydraulic fluid O, used in the injection process of the injection plunger 44, to the injection cylinder 48 to act on the injection piston 46. In addition, by supplying pressurized oil to the injection cylinder 48, a force (casting pressure P) in the forward direction shown on the left in the figure is applied to the injection plunger 44.

[0032] The control device 15, in order to perform the injection process and the return process of the injection plunger 44, detects the position information of the injection piston 46 and operates the hydraulic operating mechanism 40, as well as performing all the necessary controls for casting by the die-casting machine 10.

[0033] (Casting process of die-casting machine 10 according to this embodiment) Next, the procedure for casting a casting (molded body) using the die-casting machine 10 according to this embodiment will be explained with reference to Figures 2 to 7. Figure 2 is a graph showing the changes in casting pressure P, mold pressure Q, clamping force X, mold opening force Y, and compressive force Z throughout the entire casting process using the die-casting machine 10, so it should be referred to throughout the entire casting process.

[0034] The casting pressure P is the pressure exerted on the molten metal inside the injection sleeve 42, which is pressurized by the injection plunger 44. As will be described later, until the gate G begins to close, the same casting pressure P is applied to the molten metal inside the cavity 34 according to Pascal's principle. However, after the gate G begins to close, the casting pressure P becomes the pressure applied to the molten metal inside the injection sleeve 42.

[0035] The mold pressure Q is the pressure exerted on the molten metal (=cast product) inside the cavity 34.

[0036] The clamping force X is the force exerted by the movable platen 20 in the direction that it moves toward the fixed platen 18 via the movable mold 32, and is determined from the amount of elongation (strain) of the tie bar 24 that is stretched by the movable platen 20.

[0037] The mold opening force Y is the force exerted by the molten metal and the fixed mold 30 to push the movable mold 32 away from the fixed mold 30.

[0038] The compressive force Z is the force obtained by subtracting the mold opening force Y from the clamping force X during compression, and is the force applied to the molten metal (=cast product) inside the cavity 34 via the movable mold 32.

[0039] The control device 15 operates the mold clamping drive mechanism 31 to close the movable mold 32 against the fixed mold 30, and then clamps it with a predetermined clamping force X (Figure 2(1)).

[0040] Subsequently, the control device 15 injects and fills the cavity 34 of the mold 28 by advancing the injection plunger 44 (Figure 3). At this time, the control device 15 sets the casting pressure P such that the opening force Y on the movable mold 32 due to the molten metal injected into the cavity 34 is equal to or smaller than the clamping force X of the movable mold 32 relative to the fixed mold 30, thereby injecting and filling approximately the same amount of molten metal as the volume of the cavity 34 (Figure 2(2)).

[0041] Next, the control device 15 injects and fills the cavity 34 with an amount of molten metal approximately equal to its volume, then holds it to form a chill layer on the surface of the cavity 34 (Figure 2(2)-(3)), and then moves the injection plunger 44 further forward to increase the casting pressure P, thereby injecting and filling an amount of molten metal exceeding the volume of the cavity 34 (Figure 2(3)).

[0042] The chill layer (cooled and solidified film layer) is a metallic structure formed when molten metal comes into contact with the surface of cavity 34 and is rapidly cooled. The chill layer formed on the surface of a casting is known to be beneficial in improving the strength of die-cast products because its metallic structure is fine and dense.

[0043] When the mold opening force Y is less than or equal to the clamping force X (Y ≤ X), the injection plunger 44 cannot be advanced towards the cavity 34. However, when the casting pressure P is increased (let's call the casting pressure after the increase "casting pressure P'") and the mold opening force Y becomes greater than the clamping force X (Y > X), the injection plunger 44 can advance and inject and fill an amount of molten metal exceeding the volume of the cavity 34.

[0044] Furthermore, since the mold opening force Y is greater than the clamping force X, the movable mold 32 and movable platen 20 begin to separate from the fixed mold 30 due to the mold opening force Y, as shown in Figure 4 (Figure 2 (3)). This separation is not due to the bending of the toggle mechanism 26, but to the elongation due to the elastic deformation of the tie bar 24. When the tie bar 24 elongates, the clamping force X increases by the amount of elongation (let's call this increased clamping force "clamping force X'"). The mold opening force Y caused by the casting pressure P' through the molten metal causes the tie bar 24 to elongate by a predetermined length, and the clamping force X' rises until it becomes equal to the mold opening force Y. As a result, when the clamping force X' becomes equal to the mold opening force Y (Y=X'), the separation of the movable mold 32 and movable platen 20 stops (Figure 2 (4)).

[0045] When the movable mold 32 separates from the fixed mold 30 and a gap W is created between them at the mold dividing surface, there is a concern that molten metal may flow into this gap, causing casting burrs and flash. However, in the die-casting machine 10 according to this embodiment, as described above, a chill layer is formed on the surface of the cavity 34 before the injection plunger 44 is advanced by the casting pressure P'. Therefore, the chill layer on the surface of the cavity 34 acts as a lid on the gap W, preventing the remaining unsolidified molten metal from leaking out of the gap W. In other words, at the timing of "advancing the injection plunger 44 by the casting pressure P'", the molten metal on the surface of the cavity 34 has solidified, but most of the molten metal inside the cavity 34 has not yet solidified.

[0046] After the separation of the movable mold 32 and the movable platen 20 from the fixed mold 30 stops, the injection plunger 44 also stops (Figure 2 (4) to (5)). During this time, as shown in Figure 5, the solidification of the molten metal at the gate G proceeds first, and the gate G closes (Figure 2 (5) to (6)). As a result, the pressurization and supply of molten metal from the injection plunger 44 to the cavity 34 is cut off, and the pushing effect of the injection plunger 44 ceases thereafter.

[0047] Because the gate G is blocked, even when pressurized by the injection plunger 44, the mold opening force Y according to Pascal's principle does not act on the molten metal filling the cavity 34, and the molten metal begins to cool and solidify. As a result, the mold pressure Q, which had been approximately equal to the casting pressure P or P' up to this point, decreases below the casting pressure P', and the mold opening force Y, which had been kept constant, begins to decrease rapidly (Figure 2 (5)).

[0048] On the other hand, since the tie bar 24 is extended in advance, as the mold opening force Y decreases, the tie bar 24 contracts, causing the movable mold 32 and movable platen 20 to move closer to the fixed mold 30. However, since the molten metal in the cavity 34 (part of which is solidified, but this solidified portion is also included in the term "molten metal") is sandwiched between the movable mold 32 and the fixed mold 30, the movable mold 32 and the fixed mold 30 move closer in accordance with the volume reduction due to the solidification contraction of the molten metal. Therefore, a clamping force X' or X from the movable mold 32 and the fixed mold 30 is always applied to the molten metal, generating a compressive force Z on the molten metal.

[0049] Furthermore, to compensate for the volume reduction due to solidification shrinkage, molten metal is supplied, pre-filled in a quantity greater than the volume of the cavity 34. As the tie bar 24 shrinks during the molten metal supply process, the clamping force X' or X decreases (Figure 2 (5) to (7)). During this period, the in-mold pressure Q and compressive force Z also decrease in a similar manner.

[0050] Thus, the start of gate G closure can be detected when the clamping force X' or X begins to decrease (Figure 2 (5)). Therefore, once a predetermined time has elapsed since the start of the decrease in the clamping force X' or X (a margin of safety time to ensure that gate G is completely closed), the closure of gate G is considered complete (Figure 2 (6)), and the casting pressure P from the injection plunger 44 is reduced to a lower level or set to zero (Figure 2 (7)). Since the closure of gate G is complete, even if the casting pressure P is reduced to a lower level or set to zero, there is no effect on the molten metal in the cavity 34 due to Pascal's principle.

[0051] As a result, as shown in Figure 6, the force (= remaining mold opening force Y) that was pushing the molten metal filling the space from the injection sleeve 42 to the gate G and to which casting pressure P was applied, in the direction of opening the movable mold 32 is eliminated, and the clamping force X' or X is applied only to the molten metal in the cavity 34. Consequently, the in-mold pressure Q and compressive force Z applied to the molten metal in the cavity 34 (i.e., the part that will become the casting) increase, which allows for a further improvement in the internal quality of the casting.

[0052] If the casting pressure P applied by the injection plunger 44 is not reduced after the gate G is closed, the molten metal filling the space from the injection sleeve 42 to the gate G, to which the casting pressure P has been applied, will still exert a force (= remaining mold opening force Y) that pushes the movable mold 32 in the direction of opening. As shown in Figure 2, the mold opening force Y will remain unchanged, and the in-mold pressure Q and compressive force Z applied to the molten metal in the cavity 34 (i.e., the part that will become the casting) will not increase by the amount of this mold opening force Y.

[0053] Subsequently, as shown in Figure 7, once the solidification of the molten metal in the cavity 34 is complete, a gap W' narrower than the gap W at (4) to (5) in Figure 2 exists between the fixed mold 30 and the movable mold 32. In this way, a clamping force X' or X is constantly applied from the movable mold 32 and the fixed mold 30 until the solidification of the molten metal in the cavity 34 is complete, allowing pressure to continue to be generated in the molten metal, thus providing a riser effect even after the gate G is closed. This is represented by the fact that the clamping force at (8) to (9) in Figure 2 is greater than the clamping force X at (1) when clamping is complete.

[0054] Then, after the molten metal has solidified, the clamping drive mechanism 31 of the clamping device 12 is operated to separate the movable mold 32 from the fixed mold 30 (mold opening) (Figure 2 (9)), and the casting is removed from the cavity 34 using an ejector pin or the like (not shown). This completes the casting of the product by the die-casting machine 10.

[0055] Furthermore, in the die-casting machine 10 according to this embodiment, as described above, by controlling the injection plunger 44 to adjust only the casting pressure P(P') (related to the mold opening force) of the molten metal in the cavity 34, the separation distance (gap W) of the mold 28 during the casting process and the clamping force X at the completion of solidification of the molten metal (Figure 2 (7)) can be freely adjusted without controlling the mold clamping drive mechanism 31 during the casting process.

[0056] (Variation 1) In the above-described embodiment, the clamping force measuring device 27 was used to detect the start of gate G closure by measuring the clamping force X. However, as shown in Figure 2, instead of measuring the clamping force X, the start of gate G closure may be determined by detecting a decrease in the in-mold pressure Q or compressive force Z, and the closure of gate G may be considered complete when a predetermined time has elapsed since the start of the decrease in the in-mold pressure Q or compressive force Z.

[0057] In this specification, the clamping force X, mold pressure Q, or compressive force Z that can detect the start of gate G closure are collectively referred to as "gate closure detection parameters." Furthermore, the device that measures these "gate closure detection parameters" is collectively referred to as a "gate closure detection parameter measuring device."

[0058] (Modification 2) The fixed mold 30 and movable mold 32 in the above-described embodiment show an example where the mold dividing surface is flat to the periphery, but the present invention is not limited to this, and a shear edge structure can be adopted. A shear edge structure refers to a fitting structure formed between the fixed mold 30 and the movable mold 32 that can be inserted and removed from each other while sliding against each other. By adopting a shear edge structure, it is effective in preventing the molten metal injected into the cavity 34 from leaking out of the mold. In particular, in the present invention, the effect of preventing molten metal leakage by adopting a shear edge structure allows for further widening of the gap W (further extending the tie bar 24), so the riser effect can be made more pronounced by increasing the clamping force X applied to the molten metal and increasing the amount of molten metal supplied. A shear edge structure is also called a spigot structure or a spigot structure.

[0059] (Variation 3) The molten metal in the embodiments described above is assumed to consist only of a liquid phase above the melting point of the metal, but the present invention is not limited to this. For example, the present invention can apply to metals that have been cooled from a molten metal consisting only of a liquid phase to a semi-solid state, or to metals that have been heated in a solid phase to generate a liquid phase, resulting in a semi-molten state with both solid and liquid components. In the present invention, molten metal consisting only of a liquid phase and metals in a semi-solid state are collectively referred to as molten metal.

[0060] (Modification 4) The injection device 14 in the above-described embodiment is assumed to be operated by hydraulic drive, but the present invention is not limited thereto. For example, the injection device 14 may be configured as an electric cylinder driven by a motor. Since it is possible to achieve higher operating precision of the plunger compared to a hydraulic cylinder, it is preferable to apply the present invention to a die-casting machine 10 that provides a more stable variable casting pressure P.

[0061] (Variation 5) Although an example of a die-casting machine 10 configured horizontally has been shown, the present invention is not limited to this. In the present invention, the die-casting machine 10 may also be configured vertically.

[0062] (Experimental variation 6) In this embodiment, the mold opening force Y change process shown in Figures 2(2) to (6) is shown as a two-stage example, but the mold opening force Y in Figures 2(3) to (5) is the minimum number of stages for mold opening force in the present invention. In other words, the mold opening force Y may be changed by varying the casting pressure P(P') in three or four or more stages.

[0063] (Example 7) Furthermore, the present invention can also be applied to multi-cavity molds that have multiple cavities in a single mold. In the case of multi-cavity molds, there is variation in the timing of closing each gate G, and conventional methods using only pressurization by an injection plunger result in variations in the riser effect, leading to variations in internal quality. However, as described above, in the present invention, clamping forces X' or X are always applied from the movable mold 32 and the fixed mold 30, and a riser effect is obtained even after the gate G has closed, so the present invention is also suitable for multi-cavity molds.

[0064] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0065] 10…Die casting machine, 12…Clamping device, 14…Injection device, 15…Control device, 16…Machine stand, 18…Fixed platen, 20…Movable platen, 22…Tailstock, 24…Tie bar, 26…Toggle mechanism, 27…Clamping force measuring device, 28…Mold, 30…Fixed mold, 31…Clamping drive mechanism, 32…Movable mold, 34…Cavity, 36…Tie bar insertion hole, 38…Injection mechanism, 40…Hydraulic operating mechanism, 42…Injection sleeve, 44…Injection plunger, 46…Injection piston, 48…Injection cylinder, 50…Hot water inlet O...Hydraulic fluid, P...Casting pressure, Q...In-mold pressure, X...Clamping force, Y...Opening force, Z...Compression force, G...Gate, W...Gap

Claims

1. A mold consisting of a fixed mold and a movable mold, The cavity formed inside the mold, An injection plunger for injecting and filling the cavity with molten metal, A clamping device that opens and closes the movable mold relative to the fixed mold and clamps it, It includes a gate blockage detection parameter measuring device that measures gate blockage detection parameters capable of detecting when gate blockage has begun, The injection plunger is, The casting pressure is set such that the clamping force of the movable mold relative to the fixed mold by the clamping device is equal to or less than the opening force of the movable mold caused by the molten metal injected into the cavity, and an amount of molten metal equal to the volume of the cavity is injected and filled. Thereafter, the casting pressure is set such that the mold opening force is greater than the mold clamping force, and an amount of molten metal exceeding the volume of the cavity is injected and filled. After the gate closure detection parameter measuring device detects that the gate has begun to close, the casting pressure is reduced to a lower or zero amount after a predetermined time has elapsed. Die-casting machine.

2. The gate blockage detection parameter is the clamping force, After a predetermined time has elapsed since the start of the decrease in the clamping force, the casting pressure is reduced to zero. The die-casting machine according to claim 1.

3. A mold consisting of a fixed mold and a movable mold, The cavity formed inside the mold, An injection plunger for injecting and filling the cavity with molten metal, A clamping device that opens and closes the movable mold relative to the fixed mold and clamps it, A die-casting method using a die-casting machine equipped with a gate blockage detection parameter measuring device that measures a gate blockage detection parameter capable of detecting when gate blockage has begun, In the injection plunger, The casting pressure is set such that the clamping force applied to the movable mold by the clamping device is equal to or less than the opening force applied to the movable mold by the molten metal injected into the cavity, and an amount of molten metal equal to the volume of the cavity is injected and filled thereafter. The casting pressure is set such that the mold opening force is greater than the clamping force, and an amount of molten metal exceeding the volume of the cavity is injected and filled. After the gate closure detection parameter measuring device detects that the gate has begun to close, the casting pressure is reduced to a lower or zero amount after a predetermined time has elapsed. Die casting method using a die casting machine.

4. The gate blockage detection parameter is the clamping force, After a predetermined time has elapsed since the start of the decrease in the clamping force, the casting pressure is reduced to zero. The die-casting method according to claim 3.

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