Vertical casting equipment

Abstract

To provide a vertical mold casting apparatus that enables stable production of high-quality casting by easily aligning gate opening / closing means and a gate, and reliably opening / closing the gate and pressurizing a molten metal in a mold cavity.SOLUTION: An apparatus comprises a gate opening / closing pressure device consisting of a slide pin that moves in and out of a gate, a slide pin tip part that is located at the tip of the slide pin and integrates a small-diameter part, a large-diameter part, and a shaft part, a slide axis adjustment part, and a slide pin drive part that moves the slide pin. The gate is closed by fitting of the small-diameter part and the gate, the large-diameter part pressurizes the molten metal filled in the mold cavity, and the gate and the small-diameter part are aligned by the slide axis adjustment part when the gate is closed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vertical casting apparatus in which molten metal in a molten metal holding furnace is filled and pressurized into a mold cavity of a casting mold located above the molten metal holding furnace via a feed pipe and a gate. [Background technology]

[0002] Casting equipment used to fill a mold cavity with molten metal such as aluminum alloy can be classified into horizontal and vertical casting equipment. Horizontal casting equipment uses a melting robot or other device to supply a predetermined amount of molten metal from a melting furnace to an injection sleeve, and then advances a plunger at high speed and pressure to fill and pressurize the material. Excess molten metal is cooled and solidified within the injection sleeve, cut from the casting, and then returned to the melting furnace for re-melting and reuse in casting.

[0003] In contrast, a vertical casting machine uses, for example, pressurized gas to pressurize the molten metal in a molten metal holding furnace, causing the molten metal to flow through a feed pipe and fill and pressurize the mold cavity. Excess molten metal flows through the feed pipe and is collected in the molten metal holding furnace without cooling or solidifying. It mixes with the molten metal in the molten metal holding furnace and is used for the next shot of casting. This results in higher molten metal recovery efficiency than a horizontal casting machine. Furthermore, there is less turbulence in the molten metal flow during filling, which can reduce casting defects caused by turbulence in the molten metal flow, such as air or gas entrapment, voids, blisters, wrinkles, cold shuts, and burrs. This makes the machine suitable for casting parts that require airtightness and strength. The present invention focuses on this vertical casting machine.

[0004] In vertical casting machines, when the pressure boosting process for increasing the density of the molten metal filled in the mold cavity is performed by controlling the pressure of the molten metal in the molten metal holding furnace, the distance from the molten metal holding furnace to the mold cavity via the feed pipe and gate is long, making the process inefficient. Therefore, the pressure boosting process is often performed by placing a pressure pin or the like in the casting mold that directly presses the molten metal in the mold cavity. In this case, a gate closing device that blocks the connection between the mold cavity and the feed pipe is required to prevent the molten metal from flowing back from the mold cavity to the feed pipe. For example, Patent Document 1 (Patent Document 1) proposes a vertical casting machine equipped with a plunger that can close the molten metal inlet gate from above. According to this machine, the molten metal inlet gate is closed by the protruding portion at the tip of the plunger, and the plunger is further advanced to pressurize the molten metal filled in the mold cavity around the protruding portion.

[0005] Patent Document 2 proposes a pressure casting method using a casting mold equipped with a nested mold for closing the molten metal inlet and a nested mold for pressurizing the molten metal filled in the mold cavity. According to this method, the amount of molten metal to be pressurized can be adjusted by adjusting the position of the nested mold for pressurization, separately from closing the molten metal inlet. Patent Document 3 also proposes a casting machine equipped with a removable pressure pin (casting machine attachment) at the lower end of the cylinder rod, which serves both to close the sprue and to pressurize the molten metal. According to this method, by appropriately replacing the pressure pin with one of appropriate dimensions, the timing of gate closure and the amount of pressurization of the molten metal in the mold cavity can be appropriately adjusted. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-125401 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-597 [Patent Document 3] Japanese Patent Application Laid-Open No. 2016-87677 Summary of the Invention [Problem to be solved by the invention]

[0007] In each of Patent Documents 1 to 3, the closing of the gate (molten metal inlet gate, molten metal inlet, or sprue) and the pressurization of the molten metal filled in the mold cavity (pressure increase process) are performed simultaneously. To achieve this, the tip of the sliding pin (e.g., plunger or cylinder rod) that slides back and forth relative to the gate is given a distinctive shape. The tip has a small-diameter protrusion that fits to close the gate and a large-diameter portion with a large flat surface that presses against the molten metal. The fitting gap between the protrusion and the gate is precisely adjusted to prevent molten metal leakage. The sliding pin's drive mechanism is located outside the casting mold or the mold clamping device that supports the casting mold. In other words, due to the distance between the drive mechanism and the gate, the sliding pin is necessarily long. As a result, it is difficult to align the sliding pin with the gate, and misalignment is quite likely to occur.

[0008] Misalignment between the sliding pin and the gate can occur due to, for example, the gap in the mold guide pin that adjusts the fit between the fixed and movable dies of the casting mold, the machining and assembly accuracy of the casting mold, the installation accuracy of the casting mold and the clamping device, the sliding clearance of the clamping device, temperature expansion of the casting mold, and wear and tear on the casting mold and the clamping device. As a result, the protrusion of the sliding pin and the gate do not fit properly, causing the gate to fail to close and the molten metal in the mold cavity to backflow into the feed pipe. This results in insufficient molten metal volume and molten metal pressure during the pressure buildup process, leading to casting defects such as blowholes, voids, deformation, dimensional changes, and reduced strength of the casting. Furthermore, repeated forced fit between the protrusion of the sliding pin and the gate can cause wear and tear on the gate and the protrusion of the sliding pin, as well as wear and tear on the larger diameter of the sliding pin, making it easier for molten metal to penetrate and gall the sliding part, preventing the set casting pressure from being applied and causing various other problems, such as reduced casting quality. Furthermore, there is also concern that the sliding pin's return operation time will be extended, resulting in process abnormalities.

[0009] Therefore, an object of the present invention is to provide a vertical casting device that allows for easy alignment of the gate opening / closing means with the gate, reliably opening and closing the gate and pressurizing the molten metal in the mold cavity, and enables stable production of high-quality castings. [Means for solving the problem]

[0010] The vertical casting apparatus of the present invention comprises: A vertical casting apparatus in which molten metal in a molten metal holding furnace is filled and pressurized into a mold cavity of a casting mold disposed above the molten metal holding furnace through a feed pipe and a gate, a sliding pin that moves forward and backward relative to the gate; a sliding pin tip portion that is disposed at the tip of the sliding pin and has a small diameter portion, a large diameter portion, and a shaft portion integrated together; a sliding shaft adjustment portion; and a sliding pin drive portion that operates the sliding pin; The gate is closed by fitting the small diameter portion with the gate, the large diameter portion pressurizes the molten metal filled in the mold cavity, and when the gate is closed, the sliding axis adjustment portion aligns the gate with the small diameter portion.

[0011] In the vertical casting apparatus of the present invention, It is preferable that the sliding shaft adjustment portion is composed of an adjustment ring and a fixing nut, and that the adjustment ring is fitted to the shaft portion, and the sliding pin and the sliding pin tip portion are fastened together with the fixing nut fastened to the adjustment ring and the shaft portion.

[0012] Further, in the vertical casting apparatus of the present invention, It is preferable that a gap necessary for the alignment be provided between the inner peripheral surface of the adjustment ring and the outer peripheral surface of the shaft portion. [Effects of the Invention]

[0013] According to the present invention, a vertical casting apparatus can be provided that allows for easy alignment of the gate opening / closing means with the gate, reliably opening and closing the gate and pressurizing the molten metal in the mold cavity, and enables stable production of high-quality castings. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a conceptual diagram showing a vertical casting apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a detailed view of a gate opening / closing pressure device of the vertical casting machine shown in FIG. [Figure 3] 3A and 3B are diagrams illustrating an embodiment of the sliding pin adjustment ring shown in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0015] Preferred embodiments for carrying out the present invention will be described below with reference to the drawings. Note that the following embodiments do not limit the inventions according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solutions of the inventions according to the claims. Furthermore, in the present embodiments, the scales and dimensions of each component may be exaggerated, and some components may be omitted.

[0016] (Vertical casting equipment) First, a vertical casting apparatus according to an embodiment of the present invention will be described with reference to Fig. 1. The vertical casting apparatus 100 shown in Fig. 1 includes a casting mold 10, a pressure device 20, a mold clamping device 30, a control device 40, and a gate opening / closing pressure device 50.

[0017] The casting mold 10 includes a fixed mold 11 and a movable mold 12. The movable mold 12 is disposed above the fixed mold 11, and a mold cavity 13 is formed by operating a mold clamping device 30 to clamp the fixed mold 11 and the movable mold 12 together. The fixed mold 11 is provided with a gate 13G for filling the mold cavity 13 with molten metal. The fixed mold 11 and the movable mold 12 are heated and controlled by a heating means (not shown) or the like to temperatures appropriate for the flow and cooling of the molten metal filled into the mold cavity 13. If necessary, a mold release agent is applied to the mold cavity 13 before filling the molten metal.

[0018] The pressurizing device 20 is disposed below the casting mold 10 and includes a molten metal holding furnace 22 for storing molten metal M therein, a sealed chamber 21 for accommodating the molten metal holding furnace 22, and a feed pipe 23 for supplying the molten metal M from the molten metal holding furnace 22 into the mold cavity 13 via the gate 13G of the casting mold 10. The molten metal M is made of a metal material, such as an aluminum alloy, that is appropriately selected and adjusted to a predetermined composition depending on the intended use of the casting product, and is melted and maintained at a predetermined temperature. For this purpose, the molten metal holding furnace 22 is equipped with a temperature adjusting means (not shown). Alternatively, a separate means for producing the molten metal M, such as a melting furnace, may be provided to periodically replenish the molten metal M into the molten metal holding furnace 22. For example, pressurized gas may be supplied into the sealed chamber 21 to pressurize the sealed chamber 21, thereby pressing the molten metal M in the molten metal holding furnace 22, causing the molten metal M to rise up the feed pipe 23 and be filled and pressurized toward the mold cavity 13 via the gate 13G. The molten metal supply pipe 23 is made of, for example, a ceramic material that has heat insulating properties and low wettability with the molten metal M. Furthermore, it is preferable that the molten metal supply pipe 23 and the gate 13G are heated and maintained at a predetermined temperature so that the molten metal M inside does not solidify.

[0019] The mold clamping unit 30 is disposed above the pressure device 20 and includes, in order from bottom to top, a fixed platen 31 that supports the fixed mold 11, a movable platen 32 that supports the movable mold 12, and a mold clamping platen 33 that supports a mold clamping drive unit 35. The fixed platen 31 and the mold clamping platen 33 are connected by multiple tie bars 34. The movable platen 32, disposed between the fixed platen 31 and the mold clamping platen 33, has multiple tie bars 34 penetrating it, and performs mold opening and closing operations using the tie bars 34 as guides. Regarding the operations of the movable platen 32, the downward movement thereof toward the fixed platen 31 is defined as a mold closing operation, the upward movement thereof away from the fixed platen 31 is defined as a mold opening operation, the completion position of the mold closing operation is defined as a mold clamping limit, and the completion position of the mold opening operation is defined as a mold opening limit. In addition, the state in which the fixed mold 11 and the movable mold 12 abut is defined as a mold touch point, the mold closing operation from the mold touch point to the mold clamping limit is defined as a pressure increasing operation (or mold clamping operation), and the mold opening operation from the mold clamping limit to the mold touch point is defined as a pressure decreasing operation. At the mold clamping limit, a mold cavity 13 is formed, and the pressing force (mold clamping force) between the fixed mold 11 and the movable mold 12 reaches a maximum value (maximum mold clamping force).

[0020] The clamping drive unit 35 uses a hydraulic drive means such as a hydraulic cylinder. The clamping drive unit 35 and the movable platen 32 are connected by a cylinder rod 35R, and operating the clamping drive unit 35 performs mold opening and closing operations, and pressure increase and decrease operations for the movable platen 32 and the movable mold 12. Note that the clamping drive unit 35 is not limited to a hydraulic drive means such as a hydraulic cylinder, and may be, for example, an electric drive means combining an electric motor with a ball screw mechanism that converts rotational motion into linear motion, or a combination of a hydraulic drive means and an electric drive means. Alternatively, a toggle-type clamping means combining multiple toggle link mechanisms may be used. Alternatively, a hybrid-type clamping means in which a hydraulic drive means or an electric drive means is used for mold opening and closing operations, and a hydraulic drive means such as a hydraulic cylinder is disposed at the tip of the tie bar 34 for pressure increase and decrease operations may be used. There are no particular limitations on the clamping device 30 as long as it can accurately control the mold opening and closing position, mold opening and closing speed, and clamping force of the movable mold 12 during mold opening and closing operations, and pressure increase and decrease operations.

[0021] The control device 40 includes a pressure control unit 41 that operates the pressure device 20 to control operations such as filling the molten metal M, a mold clamping control unit 45 that operates the mold clamping drive unit 35 to control the operation of the mold clamping device 30, an opening / closing pressure control unit 46 that operates the gate opening / closing pressure device 50, and a casting control unit 47 that issues operation commands to the pressure control unit 41, the mold clamping control unit 45, and the opening / closing pressure control unit 46 based on a preset control pattern to control the casting molding.

[0022] The pressurization control unit 41 includes a flow rate adjusting means 42 with a flow path switching function, a pressurized gas supply source 43 with a pressure adjusting function, and a pressure measuring means 44 for measuring the pressure of the pressurized gas in the sealed chamber 21. The pressurized gas stored in the pressurized gas supply source 43 and adjusted to a predetermined pressure is supplied to the sealed chamber 21 at a predetermined flow rate adjusted by the flow rate adjusting means 42, and the pressure in the sealed chamber 21 is controlled so that the target pressure set in the pressurization control unit 41 matches the pressure measured by the pressure measuring means 44. As a result, the molten metal M in the molten metal storage furnace 22 is pressed, and the filling and pressurization of the molten metal M in the mold cavity 13 is controlled via the molten metal supply pipe 23 and the gate 13G. At any timing after filling or pressurization, the flow rate adjusting means 42 is operated to discharge the pressurized gas in the sealed chamber 21, reducing the pressure in the sealed chamber 21, and a molten metal recovery operation is performed in which the molten metal M remaining in the molten metal supply pipe 23 is returned to the molten metal storage furnace 22.

[0023] Furthermore, although inexpensive compressed air may be used as the pressurized gas, it is preferable to use an inert gas such as argon or nitrogen from the viewpoint of stabilizing the quality by preventing oxidation of the molten metal M. In this case, it is preferable to maintain the sealed chamber 21 and the molten metal supply pipe 23 filled with the inert gas. In addition, for nitrogen gas, a nitrogen gas generator that separates and collects only nitrogen gas from air using a separation membrane, an adsorption membrane, or the like may be used as the pressurized gas supply source 43.

[0024] 1 supplies pressurized gas to the sealed chamber 21 to pressurize the molten metal in the molten metal storage furnace 22, filling and pressurizing the molten metal into the mold cavity 13 via the molten metal supply pipe 23. However, the present invention is not limited to this. For example, a piston-type pressurizing means may be connected to the molten metal supply pipe 23 within the molten metal M in the molten metal storage furnace 22, and the molten metal M may be pressed by operating the piston to fill and pressurize the molten metal via the molten metal supply pipe 23. Alternatively, an electromagnetic pump may be used to pressurize the molten metal M from the molten metal storage furnace 22, filling and pressurizing the molten metal via the molten metal supply pipe 23. Furthermore, for example, an injection device equipped with an injection sleeve (corresponding to the molten metal supply pipe 23) and a plunger may be vertically disposed below the mold clamping unit 30, transporting the molten metal from the molten metal storage furnace 22 and supplying it into the injection sleeve, and the forward movement of the plunger may pressurize the molten metal M in the injection sleeve to fill and pressurize the mold cavity 13.

[0025] (Gate opening and closing pressure device) As shown in FIG. 1 , the gate opening / closing / pressurizing device 50 is disposed above and opposite the gate 13G, and opens and closes the gate 13G and pressurizes the molten metal M filled in the mold cavity 13. The device includes a sliding pin 54 that slides freely back and forth relative to the gate 13G, a guide bush 53 that is disposed within the movable mold 12 and houses the sliding pin 54, and a sliding pin drive unit 55 that moves the sliding pin 54 back and forth. A removable sliding pin tip portion 51 and a sliding axis adjustment unit 52 are disposed at the tip of the sliding pin 54. The sliding pin tip portion 51 and the sliding axis adjustment unit 52 slide within the guide bush 53. The rear end of the sliding pin 54 is connected to the sliding pin drive unit 55. Regarding the movement of the sliding pin 54, the movement toward the gate 13G is defined as an advancement movement, and the movement away from the gate 13G is defined as a retreat movement.

[0026] In FIG. 1 , the sliding pin drive unit 55 is disposed above the movable platen 32. However, this is not limiting. For example, it may be disposed above the mold clamping platen 33. Alternatively, if there is sufficient dimensional space, it may be disposed within the movable mold 12. It may also be a hydraulic drive unit such as a hydraulic cylinder, or an electric drive unit combining an electric motor and a ball screw mechanism. In order to prioritize machining accuracy, it is preferable that the sliding pin tip 51 and the sliding axis adjustment unit 52 have a cylindrical shape, and the guide bush 53 has a cylindrical shape. However, they may also have a concentric polygonal shape. It is also preferable that the sliding pin 54 and the sliding pin tip 51 have an internal cooling circuit to maintain an appropriate temperature.

[0027] Next, the sliding pin tip 51 and sliding axis adjustment unit 52 of the gate opening / closing pressure device 50 will be described with reference to Figure 2. Figure 2(a) shows a state in which the gate opening / closing pressure device 50 has moved backward to open the gate 13G, and Figure 2(b) shows a state in which the gate opening / closing pressure device 50 has moved forward to close the gate 13G. Figure 2(c) shows the arrangement of the sliding pin tip 51 and sliding axis adjustment unit 52 when the gate 13G is open, and Figure 2(d) shows the arrangement of the sliding pin tip 51 and sliding axis adjustment unit 52 when the gate 13G is closed.

[0028] Here, a brief description will be given of the operation of the gate opening / closing pressurizing device 50 during casting. First, as shown in FIG. 2(a), the movable mold 12 and the fixed mold 11 are clamped together to form a mold cavity 13 (mold clamping process). At this time, the sliding pin tip 51 and the sliding axis adjustment part 52 are housed in the guide bush 53, and the gate 13G is open. Molten metal M is filled into the mold cavity 13 from the molten metal holding furnace 22 of the pressurizing device 20 via the gate 13G (filling process). After the molten metal M is filled, as shown in FIG. 2(b), the sliding pin tip 51 and the sliding axis adjustment part 52 move forward to close the gate 13G, and the mold cavity 13 is sealed. Furthermore, the sliding pin tip 51 and the sliding axis adjustment part 52 move forward to pressurize the molten metal M in the sealed mold cavity 13 (pressure increase process and pressure holding process). The molten metal M is cooled and maintained under pressure (cooling process), after which the movable mold 12 is opened (mold opening process) and the cooled and solidified casting is removed from the mold cavity 13 (product removal process). After the gate 13G is closed, the molten metal M remaining in the molten metal supply pipe 23 is returned to the molten metal holding furnace 22 of the pressurizing device 20 (molten metal recovery process). This casting operation is repeated until the set number of castings is obtained.

[0029] Next, the configuration of the sliding pin tip 51 and the sliding shaft adjuster 52 will be described in detail with reference to FIG. 2(c). The sliding pin tip 51 is composed of, from bottom to top, a small-diameter portion 51S, a large-diameter portion 51D, and a shaft portion 51Z. The gate 13G is closed by fitting the small-diameter portion 51S with the gate 13G, isolating the molten metal pipe 23 from the mold cavity 13. To completely prevent leakage of the molten metal M during the pressure-increasing and pressure-holding processes, the gap S0 is preferably adjusted to approximately 0.05 mm, as shown in FIG. 2(d), taking into account factors such as thermal expansion of the small-diameter portion 51S and the gate 13G due to the high temperature of the molten metal M. Similarly, the gap S1 between the large-diameter portion 51D and the guide bush 53 is adjusted to prevent leakage of the molten metal M. Note that to ensure reliable closure of the gate 13G, it is preferable that the gap S0 be smaller than the gap S1.

[0030] The sliding axis adjustment part 52 is composed of a cylindrical adjustment ring 52R and a fixing nut 52N. The adjustment ring 52R is fitted onto the shaft portion 51Z of the sliding pin tip portion 51 and fixed by pressing down from above with the fixing nut 52N. The fixing nut 52N and the shaft portion 51Z are detachably fastened using a means such as a screw connection. With the sliding axis adjustment part 52 attached to the sliding pin tip portion 51, it is detachably fastened to the sliding pin 54 using a means such as a screw connection. In this state, the sliding pin tip portion 51 and the sliding axis adjustment part 52 move back and forth within the guide bush 53. Therefore, to prevent the molten metal M from leaking from the gap S2 between the adjustment ring 52R and the guide bush 53, the gap S1 is preferably adjusted to be equal to the gap S2. In other words, the double structure of the two gaps (S1, S2) reliably prevents the molten metal M from leaking.

[0031] The role of the sliding axis adjuster 52 is to align the axis Z1 of the small-diameter portion 51S of the sliding pin tip 51 with the axis Z2 of the gate 13G to smoothly open and close the gate 13G and ensure reliable closure. The longer the sliding pin 54, the more likely an error ZG will occur between these two axes (Z1, Z2), as shown in Figure 2(c). The error ZG may also be caused by the fastening state between the sliding pin 54, the sliding pin drive unit 55, and the sliding pin tip 51. The error ZG may also be caused by the dimensional tolerance of the mold guide pins that adjust the positioning of the fixed mold 11 and movable mold 12 of the casting mold 10, the machining accuracy and assembly accuracy of the casting mold 10, the installation accuracy of the casting mold 10 and the mold clamping unit 30, the assembly tolerance of the mold clamping unit 30, the temperature expansion of the casting mold 10, and wear and tear on the casting mold 10 and the mold clamping unit 30. In this way, it is believed that many factors cause the error ZG between the two axis centers (Z1, Z2).

[0032] If casting is performed with an error ZG occurring between the two axes (Z1, Z2), the small diameter portion 51S of the sliding pin tip 51 and the gate 13G will not fit together properly, causing the gate 13G to close unstably, resulting in a problem in which the molten metal M in the mold cavity 13 leaks out of the gate 13G and flows back into the molten metal supply pipe 23. As a result, the amount of molten metal M (molten metal replenishment amount) and molten metal pressure (casting pressure) required for the pressure increase process and pressure holding process will be insufficient, causing casting defects such as blowholes, voids, deformation, dimensional changes, and reduced strength of the casting. Furthermore, if casting is continued with an error ZG occurring in the two axis centers (Z1, Z2), the small diameter portion 51S of the sliding pin tip 51 and the gate 13G will repeatedly be forced to fit together, causing wear and tear on the gate 13G and the small diameter portion 51S, or wear and tear on the large diameter portion 51D, which will cause the molten metal to penetrate the sliding surface between the small diameter portion 51S and the gate 13G, or the sliding surface between the large diameter portion 51D and the guide bush 53, resulting in galling, or the molten metal will leak from the sliding surface, making it impossible to apply the casting pressure required in the pressure increase process and pressure holding process, making it difficult to obtain a high-quality casting.

[0033] Furthermore, there is a concern that process abnormalities may occur, such as fluctuations in the opening and closing time of gate 13G and the forward and backward movement time of sliding pin 54, making the casting cycle unstable. Also, maintenance work such as replacing worn and damaged parts and correcting the error ZG between the two axis centers (Z1, Z2) will be required, which will interrupt casting and significantly reduce productivity.

[0034] Therefore, an axis adjustment gap S3 is provided between the inner peripheral surface of the adjustment ring 52R and the shaft portion 51Z of the sliding pin tip 51. The error ZG between the two axes (Z1, Z2) is eliminated within the range of this axis adjustment gap S3. Specifically, as shown in FIG. 2(d), when the tip of the small diameter portion 51S moves forward and engages with the gate 13G, the sliding pin tip 51 moves within the range of the axis adjustment gap S3, and the two axes (Z1, Z2) coincide with each other to form a single axis Z3. For this reason, the relationship between the axis adjustment gap S3 and the error ZG is set to S3 > ZG. Furthermore, the tip of the small diameter portion 51S is preferably conical in shape to serve as a guide when the small diameter portion 51S and the gate 13G begin to engage, making it easier to correct the error ZG. The upper portion of the gate 13G may also be widened conically.

[0035] By providing the axis adjustment gap S3 between the adjustment ring 52R and the shaft 51Z, the two axes (Z1, Z2) are automatically aligned in accordance with the opening and closing operation of the gate 13G. This eliminates the problems that occurred during casting when an error ZG existed between the two axes (Z1, Z2), ensuring stable production of high-quality castings. Furthermore, it is possible to prevent galling damage to the sliding surfaces of the gate 13G, the sliding pin tip 51, the guide bush 53, etc., thereby extending the life of these components and improving casting productivity. Furthermore, by making the sliding pin 54, the sliding pin tip 51, and the sliding shaft adjustment part 52 detachable, maintenance such as part replacement is simplified, significantly reducing downtime during casting, and significantly improving casting productivity.

[0036] Next, an embodiment of the shape of the outer peripheral surface of the adjustment ring 52R will be described with reference to FIG. 3. First, as shown in FIG. 3(a), the adjustment ring 52R is basically straight, forming a gap S2 across the entire outer peripheral surface. The axis Z1 of the small-diameter portion 51S of the sliding pin tip 51 is adjusted within the axis adjustment gap S3. Note that if the axis Z1 cannot be adjusted within the axis adjustment gap S3, it is preferable to use an adjustment ring 52R shaped as shown in FIG. 3(b) or 3(c). In FIG. 3(b), the gap S2 is provided on a portion of the outer peripheral surface of the adjustment ring 52R, and the remaining outer peripheral surface is chamfered in a tapered shape. If the axis Z1 exceeds the adjustment range of the axis adjustment gap S3, this tapered shape is used to tilt the adjustment ring 52R for adjustment. In FIG. 3(c), the outer peripheral surface of the adjustment ring 52R is rounded, making it easier to tilt the adjustment ring 52R. Furthermore, even if the adjustment ring 52R is tilted, the gap S2 can be secured due to the R-surface shape, and the effect of suppressing leakage of the molten metal M is exhibited.

[0037] Figure 3(d) shows the outer peripheral surface of the straight ring-shaped ring shown in Figure 3(a) with multiple rows of minute circular grooves. These circular grooves, also known as labyrinth grooves RB, provide a high sealing performance against liquids and gases. For example, if liquid leaks from one gap S2 into the adjacent groove, the sudden expansion of the volume significantly reduces the pressure of the liquid within the groove. This repetition significantly reduces the pressure of the liquid, stopping the leak (sealing). This principle is applied to suppressing the amount of molten metal spillage. Note that this labyrinth groove shape may also be applied to Figure 3(b) or Figure 3(c). While the adjusting ring 52R is shown as a single cylinder, multiple cylindrical shapes may be stacked. Furthermore, the shape shown in Figure 3(b) or Figure 3(c) may also be applied to the inner peripheral surface of the adjusting ring 52R.

[0038] The steel material for the sliding pin tip 51, gate 13G, or guide bush 53 is selected appropriately depending on the usage environment, purpose, etc. For example, if the primary goal is to extend the life of the components by reducing wear damage, a high-hardness, wear-resistant alloy steel is selected. Furthermore, if temperature embrittlement due to high-temperature molten metal M is a concern, a heat-resistant alloy steel with excellent high-temperature strength is preferably selected. Hardening alloy steel, whose surface hardness increases due to stress generated during sliding or engagement, may also be used. Furthermore, the steel materials of the sliding or engagement components may have different hardness levels, so that one of them is a consumable component for easy replacement. Heat-treated steel, whose surface hardness has been increased by nitriding or carburizing, may also be used. Surface-treated steel, whose wear resistance and sliding properties have been appropriately adjusted by forming a hard coating layer of chromium nitride or titanium nitride using metal vapor deposition or metal irradiation, may also be used. Furthermore, the thermal expansion coefficient of the steel may be used to fine-tune the dimensional tolerances for sliding or engagement. Also, for example, the adjustment ring 52R may be formed from an elastic material to widen the adjustment range of the axis Z1, or a hybrid structure may be used that combines an outer layer of wear-resistant alloy steel with an inner layer of elastic material.

[0039] (effect) As described above, the gate opening / closing / pressurizing device 50 of the vertical casting apparatus 100, which fills and pressurizes the mold cavity 13 with molten metal M through the gate 13G, is equipped with a removable sliding axis adjustment unit 52 that automatically corrects misalignment between the gate 13G and the gate opening / closing / pressurizing device 50. This allows for accurate alignment between the two, reliably avoiding malfunctions caused by misalignment. For example, a malfunction in closing the gate 13G can cause the molten metal M in the mold cavity 13 to flow back toward the feed pipe 23 during the pressure-boosting and pressure-holding steps, resulting in an insufficient amount of molten metal and molten metal pressure required for the pressure-boosting and pressure-holding steps, resulting in insufficient molten metal replenishment and casting pressure. Furthermore, repeated forced opening and closing of the gate 13G can cause wear and tear on the sliding and mating surfaces, resulting in galling due to the molten metal M penetrating the damaged area, or the molten metal M leaking from the damaged area, preventing the casting pressure required for the pressure-boosting and pressure-holding steps from being accurately applied. This reliably eliminates such malfunctions. As a result, it is possible to avoid casting defects such as blowholes, voids, deformation, dimensional changes, reduced strength of the casting, and the inclusion of foreign matter, and it is also possible to avoid interruptions to casting due to part replacement, thereby providing stable production of high-quality castings.

[0040] Although the preferred embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the scope described in the above-described embodiments. Various modifications and improvements can be made to the above-described embodiments. [Explanation of symbols]

[0041] 100 Vertical casting equipment 10 Casting mold 11 Fixed mold 12 Movable mold 13 Mold cavity Gate 13G 20 Pressure device 21 Closed room 22 Molten metal holding furnace 23 Hot water pipe 30 Mold clamping device 31 Fixed plate 32 Movable plate 33 Mold clamping board 34 Tie bar 35 Mold clamping drive unit 35R cylinder rod 40 Control device 41 Pressure control section 42 Flow rate adjustment means 43 Pressurized gas supply source 44 Pressure measurement means 45 Mold clamping control section 46 Opening / closing pressure control section 47 Casting Control Unit 50 Gate opening and closing pressure device 51 Sliding pin tip 51S Small diameter section 51D Large diameter section 51Z Shaft S0~S2 gap S3 Axis center adjustment gap 52 Sliding axis adjustment part 52R adjustment ring 52N fixing nut 53 Guide bush 54 Sliding pin 55 Sliding pin drive unit Z1~Z3 axis center ZG error M molten metal RB groove shape

Claims

1. A vertical casting apparatus in which molten metal in a molten metal holding furnace is filled and pressurized into a mold cavity of a casting mold disposed above the molten metal holding furnace through a feed pipe and a gate, a sliding pin that moves forward and backward relative to the gate; a sliding pin tip portion that is disposed at the tip of the sliding pin and has a small diameter portion, a large diameter portion, and a shaft portion integrated together; a sliding shaft adjustment portion; and a sliding pin drive portion that operates the sliding pin; The gate is closed by fitting the small diameter portion and the gate together, the large diameter portion pressurizes the molten metal filled in the mold cavity, and when the gate is closed, the sliding shaft adjustment portion aligns the gate with the small diameter portion, the sliding shaft adjustment unit includes an adjustment ring and a fixing nut, and the adjustment ring is fitted onto the shaft portion, and the fixing nut fastens the adjustment ring and the shaft portion together, and then the sliding pin and the sliding pin tip portion are fastened together.

2. The vertical casting apparatus according to claim 1 , wherein a gap necessary for the alignment is provided between the inner peripheral surface of the adjustment ring and the outer peripheral surface of the shaft portion.

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