JP6379894B2 - Vertical mold clamping device and mold clamping control method for vertical casting machine - Google Patents

Description

  The present invention relates to a vertical mold clamping device of a vertical mold casting machine and a mold clamping control method thereof.

  The casting machine is an apparatus for casting a metal product having a desired shape by filling a mold cavity in a mold with a molten metal (molten metal) and cooling and solidifying the mold cavity. Generally, a mold with a two-part structure is clamped with a predetermined clamping force (clamping direction (horizontal clamping / clamping)), and the mold cavity is filled with molten metal (injection filling). There are various types of casting machines depending on the combination of the filling (casting) direction (horizontal casting mold / saddle casting mold) of the apparatus.

  Among these, a vertical casting machine having a vertical mold clamping device and a vertical injection device is mainly used for a squeeze casting method (molten forging method) using aluminum or the same alloy as a material. The squeeze casting method differs from the normal die casting method in which molten metal is injected and filled into the mold cavity at high speed and medium pressure, and the mold is placed in the mold composed of the upper mold and the lower mold that are clamped by the vertical mold clamping device. A cavity is formed, and the molten metal is injected and filled at a low speed and a high pressure from below to above the mold cavity. Since the molten metal is injected and filled into the mold cavity at a low speed, there is little entrainment of gas such as air into the molten metal, and since it can be pressurized for a long time, there are few internal defects and excellent mechanical properties. A casting is obtained. Therefore, the squeeze casting method is adopted for manufacturing safety parts such as aluminum wheels of automobiles, brake calipers, pressure-resistant parts of casings of antilock brake systems, suspension parts of suspension arms, and the like.

  There is also a low pressure casting method in which the molten metal is filled directly from the furnace at low and low pressures from the bottom to the top of the mold cavity inside the mold closed by the vertical mold clamping device. Yes. In the case of this low-pressure casting method, the vertical injection device is unnecessary.

  In such a squeeze casting method using a vertical casting machine, since the molten metal is injected and filled into the mold cavity at a low speed, there is little entrainment of gas in the molten metal on the vertical injection apparatus side. However, on the other hand, when filling the mold cavity with the molten metal, it is difficult to vent the gas from the mold cavity as the molten metal is filled. There was a problem with. If the degassing associated with the filling of the molten metal into the mold cavity is insufficient, the gas remaining in the mold cavity is entrained in the molten metal, which causes casting defects such as nests and blowholes.

  Also in the horizontal clamping device of the horizontal casting machine, the molten metal is filled from below (gate part) of the mold cavity and fills the mold cavity upward. Therefore, the gas in the injection sleeve and the mold cavity (air, water vapor vaporized when the moisture of the mold release agent contacts the high-temperature mold) also flows upward of the mold cavity prior to the molten metal. There is also a difference in specific gravity between these gases and molten metal, and gas with a lower specific gravity has better upward fluidity (discharge) than molten metal, and the mold-matching surface between the fixed and movable molds in the mold-clamped state ( These gases are actively discharged from the degassing gap that is intentionally placed above the parting line) or from the degassing structure such as a chill vent that is located near the upper part of the die mating surface. Can be made.

  As described above, in the horizontal mold clamping device of the horizontal casting machine, most of the gas discharge location from the mold cavity due to the flow of the molten metal in the mold cavity is above the mold, and the gas having a lower specific gravity is the molten metal. Since there is basically no structure above the mold in the mold-clamped state, it is easy to arrange the gas venting gap and the gas venting structure above the mold. The discharge of gas from the mold cavity accompanying the injection filling is relatively easy.

  On the other hand, the vertical casting machine is the same as the horizontal casting machine in that the molten metal flow direction in the mold cavity is from the bottom to the top, but the mold mating surface is horizontal (perpendicular to the mold opening / closing direction). Is different. Therefore, the gas in the mold cavity flows substantially evenly to the mold mating surface (parting line) on all the side surfaces of the mold in the clamped state as the molten metal is filled. Therefore, even if a gas venting gap or a gas venting structure is arranged only on a part of the die mating surface of the die as in the horizontal casting machine, it is difficult to vent the gas well. When a gap for gas venting or a gas venting structure is placed on the mold mating surface (parting line) around the entire side surface, the molten metal leaking from all sides of the mold or when filling is complete There is a possibility that the molten metal blows out (burr blowing) into the mold cavity (filled with molten metal).

  In order to prevent this, a predetermined clamping force is applied to the mold before filling the molten metal into the mold cavity, and from above the mold cavity (on the mounting surface side of the upper mold on the movable platen). When degassing, there is a structure called a movable plate above the upper mold, which becomes an obstacle to degassing. For this reason, a structure for discharging the gas discharged from the upper mold to the outside of the apparatus is also required on the movable platen side. As a result, the structure of the upper mold and the movable plate becomes complicated, and the gas discharge path is long. As a result, the discharge resistance increases, and there is a problem that the gas discharge performance decreases. As a method for solving this, there is an example in which the through hole of the extrusion pin of the product extrusion mechanism arranged in the movable platen and the sliding clearance of the extrusion pin are used for degassing. It is necessary to provide an extrusion pin for degassing even at a part unrelated to the purpose.

  In Patent Document 1, a lower mold to which an injection sleeve for hot water supply is connected, an upper mold main body disposed so as to be movable up and down, and an upper mold main body mounted on the lower surface of the upper mold main body, Vertical die-casting machine (saddle-type) having a raising / lowering upper die (a part of the upper die, which is directly matched with the lower die) composed of an upper die end ring portion having an air vent groove on the contact surface In the mold for casting machine), the molten metal in the injection sleeve is gradually pushed up to the mold side while keeping the half mold closed with a gap between the upper and lower molds. After the molten metal has stopped being pushed up at a position almost coincident with the gate of the mold, the lifting and lowering mold is lowered to completely close the mold, and then the molten metal is injected into the mold cavity at a high speed. A degassing method for a die casting machine is disclosed.

  When the inner diameter of the injection sleeve of the injection device is large, or when the amount of hot water supplied to the injection sleeve is small, that is, after completion of hot water supply, injection filling is started with a large amount of space (air) in the injection sleeve. A large amount of air in the injection sleeve is fed into the mold cavity prior to the molten metal. Therefore, in the degassing method of the vertical die casting machine of Patent Document 1, the molten metal in the injection sleeve is pushed up and pushed up in a half-clamped state where a gap is provided without completely fitting the lifting and lowering die to the lower die. The molten metal is stopped from being pushed up at a position where the molten metal surface substantially coincides with the lower mold gate (the molten metal filling inlet to the mold cavity). By this operation, a large amount of air (gas) in the injection sleeve is discharged from the gap between the upper and lower upper molds and the lower mold in the half mold clamped state, and is not sent into the mold cavity together with the molten metal. After that, the raising / lowering upper die is lowered to completely clamp the lower die, and the injection filling is resumed.

Japanese Patent Laid-Open No. 04-172162

  In the degassing method of the vertical die casting machine disclosed in Patent Document 1, the upper die and the lower die are held in the half mold closed state to positively form a gap, and the gas is vented from this gap. Therefore, the pushing-up of the molten metal is stopped at a place where the surface of the pushed-up molten metal substantially coincides with the gate of the lower mold, and the molten metal is prevented from leaking out of the mold from this gap. That is, it is necessary to stop the injection filling process once for each casting cycle, which not only causes deterioration of the molten metal quality due to a temperature drop, but also increases the casting cycle time. In addition, the gas in the injection sleeve is discharged by this method, but after the molten metal level pushed up substantially coincides with the lower mold gate, that is, the molten metal is located at the lowermost molten metal inlet (gate) of the mold cavity. This method does not contribute to the exhaust of the gas in the mold cavity at all because the injection filling is resumed after reaching the complete mold clamping state.

  Here, as described in Patent Document 1, the applicant does not actively form a gap between the upper mold and the lower mold, but in a mold matching (mold closed) state in which no mold clamping force is applied. If there is, the gas in the injection sleeve or mold cavity is slightly pressurized as the mold cavity is filled with molten metal by injection filling or the like, and is discharged from a minute gap formed on the mold mating surface. We focused on the points. In actuality, the mold matching surface has minute irregularities and is mold-matched (closed) by a plurality of point contacts. For this reason, a minute space communicating with the mold cavity is formed in the minute gap between the mold fitting surfaces of the molds in the mold-matched state, and the amount of the gap is within an appropriate range (about 0.5 ± 0.2 mm). ), Only the gas is discharged, and the molten metal does not leak or blow out on the same principle as chill vent.

  Even if a mold clamping force is applied to the mold, it communicates with the mold cavity while the amount of the gap is within an appropriate range in the initial stage of the process in which the mold clamping force is increased to the set mold clamping force. A very small space is maintained, and degassing in the mold cavity is continued. The applicant has introduced such a two-stage mold clamping control method utilizing the characteristics of the vertical mold clamping device to the vertical casting machine manufactured and sold by the applicant. Specifically, from the state where the upper mold is matched with the lower mold, the filling of the molten metal into the mold cavity is started, and before the molten metal in the mold cavity reaches the mold mating surface of the mold. This is a mold clamping control method in which application of a mold clamping force to a mold is started and the pressure is increased based on a preset mold clamping force boost graph.

  In addition, the chill vent is a gas that is infiltrated in a minute gap into a minute gap, and the minute amount of the infiltrated molten metal is immediately removed by heat from the mold after intrusion and solidified. This is a kind of mold degassing structure for the purpose of preventing further penetration of molten metal into the gap. Generally, the vent portion has a gap of about 0.6 to 0.7 mm, and has a triangular or quadrangular cross section. The solidification rate of the molten metal to be passed is adjusted by the length and the number of shapes of these shapes in the gas flow direction in the vent.

  The two-stage mold clamping control method will be briefly described with reference to FIGS. FIG. 8 is a schematic cross-sectional view of an upper end portion of a vertical injection apparatus and a mold of a general vertical casting machine. FIG. 9 is a relationship diagram between injection displacement and mold clamping pressure increase in the two-stage mold clamping control method.

  First, in order to facilitate understanding of the two-stage mold clamping control method, an outline of injection filling of the squeeze casting method of the vertical casting machine will be described with reference to FIG. The lower die 20 is attached to the upper surface of a fixed platen (not shown), and the mold cavity 22 is formed by combining the lower die 20 and the upper die 21 attached to the lower surface of the movable platen (not shown). The upper mold 21 can be opened / closed and clamped in the vertical direction with respect to the lower mold 20 by moving the movable plate up and down by a saddle mold clamping apparatus (not shown).

  A vertical injection device 1 is disposed below the fixed plate a predetermined distance. An injection sleeve 10 is attached to the upper end portion of the injection sleeve 10, and a plunger tip 11a is inserted into the injection sleeve 10. The plunger tip 11a is attached to the plunger rod 11b via a tip joint (not shown), and the plunger 11 composed of the plunger tip 11a and the plunger rod 11b is coaxially attached to a cylinder rod of an injection cylinder (not shown). . The injection sleeve 10 and the plunger 11 are detachably attached to the upper end portion of the injection device 1 and the injection cylinder, respectively, in order to exchange them according to the casting weight.

  In the injection standby state, the plunger tip 11a is in a position lowered downward with respect to the overall height of the injection sleeve 10 so as to close the opening at the lower end of the cylindrical injection sleeve 10, and the fixed plate, the injection sleeve 10, The molten metal supplied (hot water supply) by the molten metal holding container 30 of the hot water supply means (not shown) is stored in the injection sleeve 10 (hot water supply step). In the vertical casting machine, in order to facilitate the hot water supply process to the injection sleeve 10 by the hot water supply means, the entire injection apparatus 1 is tilted toward the hot water supply means, or the entire injection apparatus 1 is slid horizontally to the hot water supply means side. In some cases, the opening of the upper end portion of the injection sleeve 10 is moved outside the lower region of the fixed platen.

  The injection sleeve 10 is attached to the upper end portion of the injection apparatus 1 via a lifting / lowering means (not shown) independent of the injection cylinder. After the hot water supply step, the lifting / lowering means and the injection cylinder are interlocked to cause the injection sleeve 10 and the plunger tip. 11a (plunger 11) is raised integrally. Then, the upper end portion of the injection sleeve 10 is brought into contact (docking) with the injection hole 20a formed in the lower surface of the lower mold 20 through a through hole penetrating from the lower surface of the fixed plate to the upper surface. Thereafter, the plunger tip 11a is slowly raised at a high pressure of 100 to 150 MPa and at a predetermined speed (80 mm / sec. To 500 mm / sec.), And the molten metal stored in the injection sleeve 10 is moved to the lower mold. The mold cavity 22 is injected and filled via the gate portion 20b communicating between the 20 injection holes 20a and the mold cavity 22 (injection process). Even after the mold cavity is filled with the molten metal in the latter half of the injection process (injection is completed), the plunger tip 11a is appropriately raised according to the solidification shrinkage of the molten metal, and high pressure is continuously applied to the molten metal (intensification) Process). A two-dot chain line in FIG. 8 indicates the injection sleeve 10 and the like when docked to the lower mold 20.

  Next, a two-stage mold clamping control method will be described with reference to FIG. The lower horizontal axis in FIG. 9 is an injection displacement curve indicating the injection displacement from the start of injection (the position of the plunger 11 or the molten metal surface position in the injection sleeve 10 and the mold cavity 22), and a mold according to the injection displacement. Shows control commands related to clamping boosting, and the upper horizontal axis shows mold clamping boosting curves until the mold reaches the set clamping force from the mold alignment position, and mold clamping control based on control commands related to clamping clamping boosting Show. The injection start in FIG. 9 is a state of a two-dot chain line in FIG. 8 where the injection sleeve 10 is brought into contact (docking) with the injection hole 20a after the hot water supply step. At this time, the lower mold 20 and the upper mold 21 are in a state (position) in which the mold is matched (closed), and no mold clamping force is applied. From this state, injection filling starts (injection start), the plunger 11 rises, and the molten metal position in the injection sleeve 10 rises. When the plunger 11 reaches a predetermined position 1 (clamping boost command) set in advance, application of mold clamping force is started by a mold clamping device (not shown) (mold clamping boosting start).

  Thereafter, the mold clamping force is gradually increased according to a preset mold clamping pressure increase curve. The mold clamping force applied to the mold according to the mold clamping pressure increase curve is referred to as “mold clamping pressure” in order to distinguish it from the set mold clamping force which is the final target value. Then, when the plunger 11 reaches a predetermined position 2 (clamping pressure increase confirmation) from a predetermined mold clamping pressure increase command (predetermined position 1), the pressure (in the pressure side oil chamber of the hydraulic actuator of the vertical mold clamping device ( Check the measured clamping pressure. When the plunger 11 reaches the mold clamping pressure increase confirmation (predetermined position 2), the measured mold clamping pressure does not reach the mold clamping pressure (pressure increase confirmation mold clamping force) according to the mold clamping pressure increase curve. The raising of the plunger 11 is stopped until the tightening pressure reaches the pressurization confirmation mold tightening force.

  This is because when the mold clamping pressure required for the mold is not applied and the molten metal surface filled in the mold cavity exceeds the mold alignment surface, the molten metal leaks from the mold alignment surface. This is because there is a possibility of taking out. When the plunger 11 reaches the mold clamping pressure increase confirmation (predetermined position 2), if the measured mold clamping pressure reaches the pressure confirmation mold clamping force, the plunger 11 is raised (injection filling) and the mold clamping pressure is continued. After the mold clamping pressure reaches the set mold clamping force, the process proceeds to the pressure increasing process at a predetermined timing.

  In order to prevent the molten metal from leaking from the mold mating surface, generally, the mold clamping pressure increase confirmation (predetermined position 2) is performed when the molten metal surface of the molten metal pushed up is the metal when the plunger 11 reaches that position. The position that does not exceed the mold mating surface of the mold is desirable, and the pressurization confirmation mold clamping force (mold clamping pressure) at that position of the mold clamping pressure curve is a pressure that can prevent the molten metal from leaking from the mold mating surface. Is desirable. On the other hand, there are cases where the molten metal does not leak from the mold mating surface even if the molten metal surface of the molten metal exceeds the mold mating surface of the mold. The pressurization confirmation mold clamping force (mold clamping pressure) at the predetermined position 2) and the position of the mold clamping boost curve may be determined. Thus, the mold clamping pressure increase confirmation (predetermined position 2) of the plunger 11 and the pressure increase confirmation mold clamping force (mold clamping pressure) to be reached at that position are determined based on the mold specifications. In addition, based on this pressurization confirmation mold clamping force (clamping pressure), a set mold clamping force determined from the mold specifications, and a mold clamping boost curve and a target casting cycle and injection device specifications, An injection displacement curve is determined. Then, a mold clamping pressure increase command (predetermined position 1) is determined based on the mold clamping pressure increase curve and the injection displacement curve, and the injection start timing is selected in consideration of the target casting cycle and the specifications of the injection device. At the same time, the upper die 21 is moved to the die-matching position with the lower die 20 for die matching.

  Such a two-stage mold clamping control method is different from the gas venting method of Patent Document 2 in that when the plunger 11 reaches the mold clamping pressure increase confirmation (predetermined position 2), the measured mold clamping pressure is the pressure confirmation mold clamping force. Therefore, the injection filling need not be stopped, and the gas in the mold cavity not only in the injection sleeve but also in the vicinity of the mold mating surface does not require a gas venting structure. It can be discharged from the mold matching surface. Therefore, it is advantageous in terms of molten metal quality and casting cycle. Although the above has been described based on the squeeze casting method using the casting apparatus 1 of the cast iron type, the same two steps are also taken for the rise in the molten metal level in the mold cavity in the low pressure casting method described above. Needless to say, the mold clamping control method can be applied.

  However, even such a two-stage mold clamping control method has a problem due to the thermal expansion of the mold. During continuous casting, the amount of thermal expansion of the mold increases as the mold temperature rises. In particular, the gap between the die-mating surfaces of the lower die 20 and the upper die 21 that are not perfectly flat but actually has minute irregularities and are die-matched (die-closed) by a plurality of point contacts is this heat. It is easily affected by expansion, and this gap increases as the mold temperature increases. Depending on the mold and casting conditions, if the gap before the start of casting is 0.5 mm, the gap is increased by about 0.3 mm when the gap is small and about 2 mm when the gap is large due to continuous casting. For this reason, even when the plunger 11 reaches the mold clamping pressure increase command (predetermined position 1) and the mold clamping pressure increase starts, the hydraulic actuator (direct pressure type clamping mechanism) of the vertical mold clamping device is increased by this gap. It is necessary to drive downward for a long time, and during the driving, the rise of the pressure (actually measured tightening pressure) of the pressure side oil chamber of the hydraulic actuator is delayed.

  As a result, even if the plunger 11 reaches the mold clamping pressurization confirmation (predetermined position 2) and confirms the actual mold clamping pressure, the actual mold clamping pressure has not been reached because the pressurization confirmation mold clamping force has not been reached. Until the mold clamping force is reached, the raising (injection filling) of the plunger 11 is interrupted. Due to the interruption of the injection filling, there is a problem that the temperature of the molten metal in the injection sleeve 10 is lowered, and a defective product such as mixing of the generated oxide film into a cast product or defective filling due to a decrease in fluidity of the molten metal occurs. It was.

  In addition, the increase in the gap between the mold mating surfaces is not uniform with respect to the mold mating surfaces, and the gap between the mold mating surfaces is not uniform when the upper mold is not parallel to the lower mold but inclined obliquely. Often increases. In this case, even when the plunger 11 reaches the mold clamping pressure increase confirmation (predetermined position 2) and the actually measured mold clamping pressure reaches the pressure increase confirmation mold clamping force, there is a portion with a large gap on the mold matching surface of the mold. When the molten metal surface in the mold cavity exceeds the mold mating surface, even if hot water spills from that part or the mold clamping force is increased to the set mold clamping force, the large gap is not eliminated, When the mold cavity is filled with the molten metal, there is a problem that burrs are generated from the gap.

  The present invention has been made in view of the above-described problems. Specifically, in a vertical mold clamping device of a vertical casting machine in which a two-stage mold clamping control method is performed, an actual measurement is performed at the time of confirming the mold clamping pressure. In order to allow the mold clamping pressure to reach the pressurization confirmation mold clamping force, it is possible to prevent an increase in the gap between the mold mating surfaces of the lower mold and the upper mold due to thermal expansion and maintain the parallelism of the upper mold with respect to the lower mold. Thus, it is an object of the present invention to provide a vertical mold clamping device of a vertical mold casting machine capable of preventing hot water spills and burrs from the mold mating surfaces, and a mold clamping control method in the vertical mold clamping device.

The above object of the present invention is to start filling a molten metal into a mold cavity formed in an upper mold and a lower mold from a state where the upper mold is matched with the lower mold. Let
Before the molten metal in the mold cavity reaches the mold mating surface of the mold, application of mold clamping force to the mold is started based on a preset mold clamping pressure curve, and the pressure is increased to the set mold clamping force. In the vertical mold clamping device of the vertical casting machine in which the two-stage mold clamping control method is performed,
A plurality of mold clamping force generating means arranged separately from the center point of the mold mounting surface of the mold mounting board and capable of individually controlling each mold clamping force;
A mold thickness measuring means which is disposed at at least two positions symmetrical with respect to the center of the mold mounting surface of the mold mounting board, and is capable of measuring the mold thickness of the mold of the disposed portion;
This is achieved by a vertical clamping device of a vertical casting machine.

That is, a plurality of mold clamping force generating means that are arranged apart from the center point of the mold mounting surface of the mold mounting board and that can individually control the individual mold clamping forces are obtained by thermal expansion of the mold. Even when the gap between the mold mating surfaces increases unevenly while tilting with respect to the lower mold, and as a result, the mold thickness of the molds in the mold mating state increases unevenly, the mold thickness of the mold It is easy to prevent the increase of mold and to perform mold clamping control for maintaining the parallelism of the upper mold to the lower mold. In addition, the upper mold is parallel to the lower mold by mold thickness measuring means that is disposed at least at two positions symmetrical to the center of the mold mounting surface of the mold mounting board and can measure the mold thickness of the mold at the position. It is easy to check the degree. These are structures suitable for the mold clamping control method described later.

  The mold clamping force generating means may be a mold opening / closing cylinder different from the mold clamping cylinder. In a conventional vertical mold clamping device of a vertical mold casting machine, a configuration that can individually control the mold opening / closing force of a plurality of mold opening / closing cylinders is rare. This is because, in a general mold clamping control method other than the two-stage mold clamping control method, after the set mold clamping force is applied, the filling of the molten metal into the mold cavity is started. When the molten metal surface exceeds the mold mating surface, the mold is already provided with the set clamping force, and consideration is given to leakage of molten metal from the mold mating surface during filling, as in the two-stage mold clamping control method. Because there is no need to do. Therefore, maintaining the parallelism of the upper mold with respect to the lower mold at the time of mold opening / closing is not an important problem, and a configuration capable of individually controlling the mold opening / closing forces of the plurality of mold opening / closing cylinders is not necessary. However, the mold opening / closing cylinder can be used as an auxiliary actuator for increasing / decreasing the mold clamping force in the two-stage mold clamping control method by the configuration in which the mold opening / closing force of the plurality of mold opening / closing cylinders can be individually controlled.

  Generally, the mold opening / closing force by the mold opening / closing cylinder is smaller than the mold clamping force by the mold clamping cylinder. However, due to the structure, a plurality of mold opening / closing cylinders (at least one set (two units)) are arranged apart from the center point of the mold mounting surface of the mold mounting board. Therefore, even if the mold opening / closing force is smaller than the mold clamping force of a general mold clamping cylinder (clamping ram), it is arranged at the center of the mold mounting plate so that the parallelism of the upper mold with respect to the lower mold Suitable for adjustment and maintenance. In addition, the pressurization confirmation mold clamping force (mold clamping pressure) required for confirming the mold clamping pressurization according to the mold clamping force boost graph is sufficiently small relative to the set mold clamping force. In view of the control to increase or decrease the clamping pressure) within the mold clamping force adjustment range C, the mold opening / closing force by the mold opening / closing cylinder is sufficient as the mold clamping pressure when the mold clamping pressure is confirmed.

  On the other hand, the mold clamping force generating means is disposed at one end of the mold clamping piston that passes through the tie bar and is slidable in the axial direction of the tie bar, and engages the mold clamping piston and the tie bar. A mold clamping cylinder comprising: an engaging means for releasing the engagement; and an oil chamber formed between the inner space of the mold mounting plate on the side where the mold clamping piston is inserted and the mold clamping piston. There may be.

  In this case, a mold clamping cylinder is arranged for each tie bar, and each mold clamping force can be individually controlled up to the set mold clamping force. Therefore, the mold opening / closing cylinder is used as an auxiliary actuator for increasing or decreasing the mold clamping force. Further prevention of the increase in mold thickness and mold clamping control for maintaining the parallelism of the upper mold with respect to the lower mold are further facilitated.

On the other hand, the mold thickness measuring means includes a mold mounting board to which the upper mold is mounted, and a rack gear disposed between fixing members that fix either the upper or lower end of the tie bar,
Pinion gear combined with the rack gear,
An encoder for detecting the rotation angle of the pinion gear;
It is preferable that the distance between the mold mounting surfaces of the arranged part can be calculated from the rotation angle of the pinion gear. As another mold thickness measuring means, the mold of the mold of the arranged part is used. A non-contact distance sensor capable of measuring the distance between the mounting surfaces may be used.

  The former is a movable plate that has an upper mold attached and moves up and down and a fixed member that fixes the upper and lower ends of the tie bar that does not move up and down (a fixed plate that fixes the lower end of the tie bar below the movable plate, or a tie bar that moves above the movable plate. This is a mechanical mold thickness measuring means arranged directly between the upper end of the cylinder platen and the cylinder platen. Whether the rack gear is arranged between the movable platen and the fixed platen, or between the movable platen and the cylinder platen, or whether the pinion gear combined with the rack gear is arranged on the fixed platen, the movable platen or the cylinder platen. It may be selected as appropriate according to the situation. Such a mechanical mold thickness measuring means is effective for detecting and measuring a minute change in the gap between the mold mating surfaces of the upper mold and the lower mold. On the other hand, the non-contact type distance sensor such as the latter, for example, a distance sensor using infrared rays, ultrasonic waves, or a laser, has a smaller number of parts than the former and is easy to install, and therefore has more mold thickness measuring means. This is effective when it is desired to check the parallelism of the upper mold with respect to the lower mold more accurately. In order to take advantage of both advantages, the former mechanical mold thickness measuring means may be used as the main measuring means, and a large number of the latter non-contact distance sensors may be arranged and combined as the auxiliary measuring means.

Furthermore, on the premise that the vertical mold clamping device of the vertical mold casting machine as described above is used, the above object of the present invention is a state in which the upper mold is matched with the lower mold in the cold state before the start of casting. The mold thickness 1 is compared with the mold thickness 2 in which the upper mold is matched with the lower mold in the hot state after the start of casting. Clamping force is that the difference A between the mold thickness 1 and the mold thickness 2 deviates from the mold thickness tolerance B set in advance as a reference for maintaining the gap between the mold mating surfaces where the molten metal does not leak from the mold mating surfaces. The correction start point is 1,
At the mold clamping force correction start point 1, the mold clamping force of the mold clamping force generating means nearest to the mold thickness measuring means where the difference A deviates from the mold thickness tolerance B is the mold clamping force at the mold clamping force correction start point 1. The mold clamping force conforming to the pressure increase curve is increased or decreased within a mold clamping force adjustment range C set in advance as a reference for determining that the apparatus is abnormal due to factors other than the thermal expansion of the mold,
This is also achieved by a mold clamping control method in which the difference A deviating from the mold thickness allowable range B at the mold clamping force correction start point 1 is maintained within the mold thickness allowable range B at least by the position of confirmation of mold clamping pressure increase during filling. .

  That is, by comparing and monitoring the mold thickness 1 in a state where the upper mold is matched with the lower mold in the cold state before the start of casting and the mold thickness 2 after the start of casting for each mold thickness measuring means, When the upper mold is inclined with respect to the lower mold due to the thermal expansion of the mold, the gap between the mold mating surfaces increases non-uniformly, and as a result, the mold thickness of the molds in the mold mating state increases unevenly. Even in this case, according to the unequal mold thickness, the mold clamping force of the nearest mold clamping force generating means is individually controlled to maintain the mold thickness within the mold thickness tolerance B, and the lower mold and the upper mold. As a result, the parallelism of the upper mold with respect to the lower mold can be maintained. As described above, the mold clamping force generating means may use a mold opening / closing cylinder different from the mold clamping cylinder as an auxiliary actuator for generating the mold clamping force, and is arranged and configured for each tie bar. The mold clamping force by the mold clamping cylinder may be directly controlled. Regardless of the cylinder, the increase or decrease of the mold clamping force is adjusted in advance with respect to the mold clamping force according to the mold clamping force boost graph at the mold clamping force correction start point 1 for the reason described later. It is preferable to increase or decrease within the range C.

Further, in this mold clamping control method, the difference A for each mold thickness measuring means is compared, and the difference D between the two differences A of the mold thickness measuring means directly controls the parallelism of the upper mold with respect to the lower mold. A point that deviates from the mold thickness difference allowable range E set in advance as a reference for preventing spilling or flashing of burrs from the mold mating surfaces is set as a mold clamping force correction start point 2.
At the mold clamping force correction start point 2, the mold clamping force of the mold clamping force generating means closest to the two mold thickness measuring means where the difference D deviates from the mold thickness difference allowable range E is expressed as the mold clamping force correction start point 2. The mold clamping force according to the mold clamping pressure increase curve is increased or decreased within a predetermined mold clamping force adjustment range C.
At the mold clamping force correction start point 2, the difference D deviating from the mold thickness difference allowable range E may be maintained within the mold thickness difference allowable range E at least by the position of the mold clamping pressure increase confirmation during filling.

  That is, not only comparing the difference A of the mold thickness measuring means but also comparing the difference D of the difference A for each mold thickness measuring means, the parallelism of the upper mold with respect to the lower mold can be positively maintained. it can.

As a case where the mold clamping force is reduced, it is assumed that only the difference A of a specific mold thickness measuring means is significantly larger than the difference A of other mold thickness measuring means. For example, depending on the arrangement of the mold cavities, the area of the mold mating surface in the vicinity of the mold thickness measuring means (the area where there is no space as the mold cavity and the mold mating surfaces of both the upper mold and the lower mold are in direct contact) is different. In this case, even if the same mold clamping force is applied, the difference A is smaller in the portion where the area of the die mating surface is smaller than in the portion where there is a large amount for the reason described above. Due to the imbalance of the area of the mold mating surface, the mold clamping force applied to the area where the area of the mold mating surface is small, the difference A between the positions at the center point symmetrical position of the mold mounting surface It may be increased. In such a case, rather than increasing only the mold clamping force of the mold clamping force generating means nearest to the specific mold thickness measuring means, the specific mold thickness measuring means and the center of the mold mounting surface are symmetrical. The mold clamping force of the nearest clamping force generating means of the specific mold thickness measuring means is reduced after reducing the clamping force of the nearest clamping force generating means of another mold thickness measuring means. Increasing the value is effective in reducing the corresponding difference A.

  Here, in the above-described mold clamping control method, even if the mold clamping force of the mold clamping force generating means is increased or decreased within the mold clamping force adjustment range C, there is a difference A until at least the position of the mold clamping pressure confirmation during filling. When the mold thickness allowable range B is not maintained, it is preferable to stop the filling of the molten metal.

  The amount of increase in the gap between the mold mating surfaces due to the thermal expansion of continuous casting can be estimated by desktop calculations, CAE analysis, and experience. The amount can also be assumed. Therefore, it is preferable to set in advance a mold clamping force adjustment range C that is increased or decreased by the mold clamping force generating means with respect to the mold clamping force according to the mold clamping pressure increase curve. This is because the gap is not maintained in the mold thickness allowable range B even if the mold clamping force assumed to be necessary for maintaining the mold gap allowable range B is increased or decreased with respect to the assumed gap increase. In this case, a criterion for determining that the device is abnormal due to factors other than thermal expansion of the mold is provided. As an abnormality of such a device, the entry of contamination, such as aluminum debris and cast pieces on the mold mating surface, the bushing of the sliding part between the movable plate and the tie bar, or the mold clamping cylinder is arranged for each tie bar. In the present embodiment, the gap between the mold mating surfaces has increased beyond expectation due to chatter during the lowering operation of the movable platen due to wear of the bushing of the sliding cylinder portion of the clamping cylinder and the tie bar. There is a possibility. In this way, by setting the mold clamping force adjustment range C in advance and stopping the filling of the molten metal into the mold cavity when it is determined that the apparatus is abnormal, it is possible to prevent the mold and the mold clamping apparatus from being damaged. it can.

A vertical mold clamping device of a vertical caster according to the present invention is a metal mold formed in an upper mold and a lower mold in a state where the upper mold is matched with the lower mold. Start filling the mold cavity with molten metal,
Before the molten metal in the mold cavity reaches the mold mating surface of the mold, application of mold clamping force to the mold is started based on a preset mold clamping pressure curve, and the pressure is increased to the set mold clamping force. In the vertical mold clamping device of the vertical casting machine in which the two-stage mold clamping control method is performed,
A plurality of mold clamping force generating means arranged separately from the center point of the mold mounting surface of the mold mounting board and capable of individually controlling each mold clamping force;
A mold thickness measuring means which is disposed at at least two positions symmetrical with respect to the center of the mold mounting surface of the mold mounting board, and is capable of measuring the mold thickness of the mold of the disposed portion;
Due to the thermal expansion of the mold, the gap between the mold mating surfaces increases unevenly with the upper mold tilted obliquely with respect to the lower mold. Even when the thickness increases unevenly, it is easy to prevent the mold thickness of the mold from increasing and to perform mold clamping control that maintains the parallelism of the upper mold with respect to the lower mold. Further, the mold thickness measuring means is arranged at least at two places symmetrical to the center point of the mold mounting surface of the mold and can measure the mold thickness of the mold at the arranged portion, and the degree of parallelism of the upper mold with respect to the lower mold is measured. Confirmation becomes easy.

Further, according to the present invention, a mold clamping control method using a vertical mold clamping device of a vertical casting machine includes a mold thickness 1 in a state where an upper mold is matched with a lower mold in a cold state before starting casting. The mold thickness 2 in which the upper mold is matched with the lower mold in the hot state after the start of casting is compared for each mold thickness measuring means. The point at which the difference A of the mold thickness 2 deviates from the preset mold thickness allowable range B is defined as a mold clamping force correction start point 1.
At the mold clamping force correction start point 1, the mold clamping force of the mold clamping force generating means nearest to the mold thickness measuring means where the difference A deviates from the mold thickness tolerance B is the mold clamping force at the mold clamping force correction start point 1. Increase or decrease the clamping force according to the boost curve within the preset clamping force adjustment range C,
At the mold clamping force correction start point 1, the mold clamping control method is used to maintain the difference A deviating from the mold thickness tolerance range B within the mold thickness tolerance range B at least by the position of the mold clamping pressure increase confirmation during filling. Due to thermal expansion, when the upper mold is inclined obliquely with respect to the lower mold, the gap between the mold mating surfaces increases non-uniformly, and as a result, the mold thickness of the molds in the mold mating state increases unevenly. However, according to the unequal mold thickness, the mold clamping force of the nearest mold clamping force generating means is individually controlled to maintain the mold thickness within the mold thickness tolerance range. It is possible to prevent an increase in the gap between the mold mating surfaces, and to maintain the parallelism of the upper mold with respect to the lower mold as a result.

It is a side view of the vertical clamping apparatus of the vertical casting machine based on Example 1 of this invention. It is also an A arrow view of FIG. It is a front view of the vertical clamping apparatus of the vertical casting machine based on Example 1 of this invention. It is also a B arrow view of FIG. It is C arrow line view (plane sectional drawing) of FIG. It is explanatory drawing of the mold thickness measurement means of the vertical clamping apparatus of the vertical casting machine based on Example 1 of this invention. It is a front view of the vertical clamping apparatus of the vertical casting machine based on Example 2 of this invention. FIG. 6 is a view (plan view) taken along arrows E and F in FIG. 5. FIG. 7 is a view (sectional view) taken along arrow G in FIG. 6. It is a schematic sectional drawing of the upper end part of a vertical injection apparatus of a general vertical casting machine, and a metal mold | die. FIG. 6 is a relationship diagram between injection displacement and mold clamping pressure increase in a two-stage mold clamping control method. It is explanatory drawing of the mold clamping force correction | amendment start point 1 and the mold clamping force adjustment range C of the mold clamping control method which concerns on Example 1 of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings.

  With reference to FIGS. 1 to 4 and 10, a vertical mold clamping device of a vertical mold casting machine and a mold clamping control method thereof according to Embodiment 1 of the present invention will be described. Below the vertical mold clamping device 50, a fixed platen 51 to which the lower mold 60 is attached is fixed to the foundation via a gantry 51a. Further, the lower ends of the four tie bars 54 are fixed to the fixed platen 51. The upper end of the tie bar 54 is fixed to the cylinder platen 53. On the other hand, a ram cylinder body 55 a of the mold clamping ram cylinder 55 is formed at the center above the cylinder platen 53.

  Next, between the fixed platen 51 and the cylinder platen 53, a movable platen 52 to which the upper mold 61 is attached is guided by the tie bar 54 and arranged so as to be movable in the vertical direction. The movable plate 52 is fixed with cylinder rods 56b of a mold opening / closing cylinder 56 disposed at two positions apart from the center point of the mold mounting surface of the movable plate 52, and the cylinder body 56a of the mold opening / closing cylinder 56 is fixed. The rod side is fixed to the cylinder platen 53. Further, the lower end of the ram cylinder rod 55b of the mold clamping ram cylinder 55 is fixed above the movable platen 52, and the oil chamber in the ram cylinder body 55a above the cylinder platen 53 into which the ram cylinder rod 55b is inserted. A predetermined mold clamping force is generated by supplying hydraulic oil of a predetermined pressure to 55c via a hydraulic line (not shown).

  An oil tank 55d is disposed above the ram cylinder body 55a. During mold opening / closing operation of the movable platen 52 by the mold opening / closing cylinder 56 (die opening / closing stroke S (es)), a hydraulic line (not shown) between the oil chamber 55c and the oil tank 55d is open, and the movable platen 52 is lowered. The hydraulic oil in the oil tank 55d is supplied to the oil chamber 55c as the volume of the oil chamber 55c increases, and when the movable platen 52 moves up, the operation in the oil chamber 55c occurs as the volume of the oil chamber 55c decreases. The oil is returned to the oil tank 55d, and the state where the oil chamber 55c is always filled with the hydraulic oil is maintained. At the time of mold clamping, the hydraulic line is closed and hydraulic oil in the oil tank 55d is supplied to the oil chamber 55c from another hydraulic line via a hydraulic pump (not shown) to generate a predetermined mold clamping force. .

  The arrangement relationship among the four tie bars 54, the mold clamping ram cylinder 55, and the mold opening / closing cylinder 56 on the plane is as shown in FIG. 3 is a view (plan sectional view) taken along arrow C in FIG. At the four corners of the rectangular cylinder platen 53, the upper ends of the four tie bars 54 are respectively fixed, and a ram cylinder body 55a is formed at the center of the cylinder platen 53. Also, the rod side of the cylinder body 56a of the clamping cylinder 56 is fixed to both ends of the long side of the center point of the cylinder platen 53 (coincided with the center point of the mold mounting surface of the movable platen 52 on the vertical axis). The mold thickness measuring means 57 is also arranged at two locations that are also symmetrical with respect to the center of the cylinder platen 53 and are slightly spaced from the mold opening / closing cylinder 56 in the short side direction. The mold thickness measuring means 57 shown in FIG. 3 is not shown in FIGS. 1 and 2 in order to make the drawing easier to see.

  In mold clamping control for maintaining the parallelism of the upper mold 61 with respect to the lower mold 60, the ideal arrangement of the mold opening / closing cylinder 56 and the mold thickness measuring means 57 is the mold mounting surface of the movable platen 52 as in the first embodiment. In addition to being arranged at two locations (one set) that are separated from the center point and symmetrical with the same center point, another two locations (one set), that is, the mold opening / closing cylinder 56 and the mold thickness measurement in FIG. It is arranged on the long side where the means 57 is not arranged. Similarly, two sets (four places) may be arranged on the diagonal line in the vicinity of the tie bar 54 (see FIG. 6A of Example 2 described later for such arrangement). However, depending on the size and manufacturing cost of the vertical casting machine, as in the first embodiment, the mold opening / closing cylinder 56 and the mold thickness measuring means 57 are separated from the center point of the mold mounting surface of the movable plate 52, and , There are cases where it is unavoidable to place them only in two places (one set) symmetrical to the same central point. In such a case, like the mold thickness measuring means 57 shown in FIG. 3, the mold opening / closing cylinder 56 and the mold thickness measuring means 57 are passed through the center point of the cylinder platen 53 in either the long side direction or the short side direction. Long side and short side direction by arranging a small distance from one center line in the direction of the other center line or arranging a non-contact distance sensor as described above as a sub-measuring means It is preferable to be able to cope with any of these inclinations.

  Next, the mold thickness measuring means 57 will be described with reference to FIG. FIG. 4 is an explanatory diagram of mold thickness measuring means of the vertical mold clamping device of the vertical caster according to the first embodiment of the present invention. 4A is a front view of the mold thickness measuring means, FIG. 4B is a view taken in the direction of arrow D in FIG. 4A, and FIG. 4C is a detailed view of a portion P in FIG. 4B.

  The lower end of the flat rack gear 57 a is fixed to the side surface of the movable platen 52, and the upper end side thereof is disposed so as to be movable in the vertical direction via a rack gear guide 57 b disposed on the side surface of the cylinder platen 53. A pinion gear 57c combined with the rack gear 57a is rotatably supported via a pinion gear support 57d that is also disposed on the side surface of the cylinder platen 53. An input shaft of an encoder 57e that can detect the rotation angle of the pinion gear 57c is directly connected to a rotation shaft (not shown) of the pinion gear 57c that is rotatably supported by the pinion gear support 57d. The encoder 57e is disposed on the side surface of the cylinder platen 53 via the encoder support 57f so that a load other than the rotational movement of the rotation shaft of the pinion gear 57c does not act on the input shaft of the encoder 57e.

  As shown in FIG. 4A, the upper die 61 is matched with the lower die 60 in the cold state before the start of casting. In accordance with the lowering of the movable platen 52, the rack gear 57a also moves downward while rotating the pinion gear 57c. At this time, since the mold is in a cold state, when the upper mold 61 and the lower mold 60 are aligned, the gap between the mold alignment surfaces of these molds is appropriate according to the mold manufacturing specifications. Value. Actually, it is difficult to accurately measure the gap itself between the mold mating surfaces, so the encoder 57e is set to the origin with the mold thickness of the mold at this time (cold state) as the reference value (mold thickness 1), It is stored in a control device (not shown). Then, the mold thickness of the mold after the start of casting is set as a monitored value (mold thickness 2) by the mold thickness measuring means 57, and the difference A between the mold thickness 1 and the mold thickness 2 for each casting cycle is determined by the thermal expansion of the mold. This is considered as an increase in the gap between the mold mating surfaces.

  As the casting is repeated, the mold thermally expands and the gap between the mold mating surfaces increases. As a result, as described above, the mold thickness 2 in a state where the upper mold 61 is matched with the lower mold 60 gradually increases. As shown in FIG. 4C, the increase in the mold thickness, that is, the difference A is caused by moving the rack gear 57a upward and rotating the pinion gear 57c clockwise as compared with the state of the mold thickness 1. The rotation angle of the input shaft 57e is calculated by a control device (not shown). The increase amount of the mold thickness in the vicinity of the mold thickness measuring means 57 calculated in this way is compared with a mold thickness allowable range B stored in the control device in advance. The mold thickness allowable range B is determined from the mold mating surface when the molten metal filled in the mold cavity exceeds the mold mating surface when the upper mold 61 and the lower mold 60 are mated. Molten metal leaks from the mold mating surface due to the mold thickness when the gap between the mold mating surfaces is increased to the extent that the molten metal leaks, or by applying a mold clamping pressure within the mold clamping force adjustment range C described later. What is necessary is just to determine suitably adopting the maximum mold thickness etc. of the mold | die which can be maintained in the clearance gap between the mold matching surfaces of the grade which does not take out.

  The comparison between the difference A and the mold thickness allowable range B is performed for each mold thickness measuring means 57, and from the mold alignment position (injection start) shown in FIG. 9, the plunger position of the vertical mold injection device (or within the mold cavity). This is continued until at least the mold clamping pressure increase confirmation (predetermined position 2) reaches the mold clamping pressure increase position. Even if the gap between the mold mating surfaces of the mold increases and the mold thickness increases, if the increase is small, after the mold clamping pressurization start shown in FIG. The mold clamping force (clamping pressure) gradually increased is applied to the mold by the mold clamping ram cylinder 55, so that the gap (mold thickness) of the mold mating surface is confirmed by the mold clamping pressure increase (predetermined). The mold thickness tolerance B is maintained until the position 2) is reached. In this situation, it is not necessary to interrupt the raising of the plunger (or filling the molten metal into the mold cavity).

  However, the mold thickness increase amount increases, and the mold thickness allowable range B is maintained even by the mold clamping pressure applied to the mold by the mold clamping ram cylinder 55 until the mold clamping pressure increase confirmation (predetermined position 2) is reached. If the situation does not occur, the raising of the plunger (or filling of the molten metal into the mold cavity) is interrupted. Therefore, if a situation occurs in which the difference A exceeds the mold thickness allowable range B, this point is set as the mold clamping force correction start point 1 and the mold clamping control method according to the first embodiment is executed.

  In the mold clamping control method according to the first embodiment, when the occurrence of the mold clamping force correction start point 1 is recognized in at least one mold thickness measuring means 57, the mold opening / closing nearest to the mold thickness measuring means 57 is performed. The cylinder 56 (clamping force generating means) is driven in the mold closing direction (in some cases, the mold opening direction), and the mold clamping force (clamping by the mold clamping ram cylinder 55) is applied to the mold in the vicinity of the mold thickness measuring means 57. A mold clamping force (mold clamping pressure) different from the (pressure) is applied. Normally, during the injection filling process and mold clamping process after mold matching, the hydraulic line to the mold opening / closing cylinder 56 is opened so that no external force is applied to the mold clamping cylinder 56 due to changes in the mold thickness due to mold clamping. State. Therefore, after generation of the mold clamping force correction start point 1, a predetermined pressure (mold clamping pressure) is applied to the lowering side of the cylinder rod 56b of the corresponding mold opening / closing cylinder 56 (the head side of the cylinder body 56a in the first embodiment). Supply hydraulic oil. As described above, in the first embodiment, the two mold opening / closing cylinders 56 are configured such that the mold clamping force (mold opening / closing force) can be individually controlled. Therefore, such control is possible. .

  Here, the mold clamping force (mold clamping pressure) generated on the lower side of the corresponding mold opening / closing cylinder 56 conforms to, for example, a mold clamping pressure increase curve at the mold clamping force correction start point 1 as shown in FIG. It is preferable to increase the clamping force K (mold clamping pressure) within a preset clamping force adjustment range C. As described above, the mold clamping force adjustment range C provides a standard for determining that the apparatus is abnormal due to factors other than the thermal expansion of the mold, and can be assumed by calculation on the desk, CAE analysis, and experience. Is. In FIG. 10, for easy understanding, the mold clamping force adjustment range C is illustrated as the mold clamping pressure increase curve that is simply translated up and down. It may be different from the boosting curve and may be set as appropriate from the viewpoint of a criterion for determining that the apparatus is abnormal. With respect to the mold clamping force generated in the mold opening / closing cylinder 56, a mold clamping force adjustment range set in advance with respect to the mold clamping force (mold clamping pressure) according to the mold clamping pressure increase curve at the mold clamping force correction start point 1. As described above, there is a case where the value is decreased in C.

  This control is performed independently only by the mold opening / closing cylinder 56 nearest to the mold thickness measuring means 57 in which the occurrence of the mold clamping force correction start point 1 is recognized. In the first embodiment, the mold opening / closing cylinder 56 and the mold thickness measuring means 57 are spaced apart from the center point of the mold mounting surface of the movable platen 52 and disposed at two locations (one set) symmetrical to the center point. Therefore, if the occurrence of the mold clamping force correction start point 1 is recognized by only one of the mold thickness measuring means 57, a predetermined mold clamping pressure is applied only by the nearest mold opening / closing cylinder 56, The mold thickness is maintained within the mold thickness tolerance B until the mold clamping pressure increase confirmation (predetermined position 2) is reached. If the occurrence of the mold clamping force correction start point 1 is recognized by both the mold thickness measuring means 57, a predetermined mold clamping pressure is applied independently by the respective nearest mold opening / closing cylinders 56. If the difference A between the two mold thickness measuring means 57 is different, control is performed to apply different mold clamping pressures within the mold clamping force adjustment range C according to the mold clamping force correction point 1 at the mold clamping force correction start point 1. Also good. Furthermore, if the difference A deviates from the mold thickness allowable range B at the mold alignment position (injection start) shown in FIG. 9, the mold clamping force correction start point 1 is recognized, and the mold clamping control according to the first embodiment is performed. The method is performed.

  As described above, in the mold clamping control method according to the first embodiment, the mold clamping pressure is controlled independently for each of the nearest mold opening / closing cylinders 56 combined with the mold thickness measuring means 57, so In order to maintain the mold thickness of the part to be held within the mold thickness tolerance B until the mold clamping pressure confirmation (predetermined position 2) is reached, thereby preventing an increase in the gap between the mold mating surfaces, and a two-stage mold clamping control method In the vertical mold clamping device of the vertical casting machine in which the measurement is performed, the measured mold clamping pressure can reach the pressure increase confirmation mold clamping force when the mold clamping pressure is confirmed. Moreover, since the parallelism of the upper mold | type with respect to a lower mold | type is maintained, the hot water spill from a metal fitting surface and a burr | flash can be prevented.

  In the first embodiment, with respect to the mold thickness measuring means 57, the rack gear 57a is arranged between the movable platen 52 and the cylinder platen 53, and the pinion gear 57c and the encoder 57e combined therewith are arranged on the cylinder platen 53. The pinion gear 57c and the encoder 57e may be arranged on the movable platen 52. Further, the rack gear 57a may be disposed between the movable platen 52 and the fixed platen 51, and the pinion gear 57c and the encoder 57e may be arranged on the movable platen 52 or the fixed platen 51.

  Next, a vertical mold clamping device and a mold clamping control method for the vertical mold casting machine according to Embodiment 2 of the present invention will be described with reference to FIGS. Example 2 differs from Example 1 in that, in the vertical mold clamping device of the vertical mold casting machine, a plurality of mold clamping force generating means arranged apart from the center point of the mold mounting surface of the mold mounting board are provided. This is not a mold opening / closing cylinder as in the first embodiment but a mold clamping cylinder arranged for each tie bar. Further, in the mold clamping control method, in addition to the mold clamping pressure control for maintaining the difference A within the mold thickness allowable range B as in the first embodiment, the difference D between the differences A for each mold thickness measuring means is determined by the mold. The mold clamping pressure to be maintained within the thickness difference allowable range E is controlled. Since the other points of the vertical mold clamping device and the mold clamping control method are basically the same as those of the first embodiment, the same constituent elements as those of the first embodiment are denoted by the same reference numerals, and the differences from the first embodiment. Only explained.

  FIG. 5 is a front view of a vertical mold clamping device of a vertical caster according to a second embodiment of the present invention. Below the vertical mold clamping device 50 ', a fixed plate 51 to which the lower mold 60 is attached is fixed to the foundation via a gantry 51a. Further, the lower ends of the four tie bars 54 are fixed to the fixed platen 51. The upper end of the tie bar 54 is fixed to the cylinder platen 53 '. Between the fixed platen 51 and the cylinder platen 53 ′, a movable platen 52 to which the upper mold 61 is attached is guided by the tie bar 54 and arranged to be movable in the vertical direction. A cylinder rod 56b of the mold opening / closing cylinder 56 is fixed to a surface of the movable platen 52 facing the fixed platen 51, and a head side of the cylinder body 56a of the mold opening / closing cylinder 56 is opposed to the movable platen 52 of the fixed platen 51. It is fixed to.

  The arrangement relationship between the four tie bars 54 and the mold opening / closing cylinder 56 on the plane is as shown in FIG. FIG. 6A is a view (plan view) taken along arrow E in FIG. At the four corners of the rectangular fixed platen 51, the lower ends of the four tie bars 54 are fixed, respectively, and the mold opening / closing cylinders 56 are arranged at four locations outside the four tie bars 54 (two sets of four). Further, mold thickness measuring means 57 are arranged at four locations on the outer side of the four tie bars 54 (two sets of four). This is a configuration in which one set (two) each of the mold opening / closing cylinder 56 and the mold thickness measuring means 57 is arranged more than the first embodiment. The arrangement of the movable platen 52 at four locations (two sets) that are separated from the center point of the die mounting surface of the movable plate 52 and symmetrical with the center point is an ideal arrangement in the form of the first embodiment.

  On the other hand, unlike the first embodiment, the mold thickness measuring means 57 shown in FIG. 6A is arranged between the movable platen 52 and the fixed platen 51. Although the detailed illustration of the mold thickness measuring means 57 in the second embodiment is omitted, specifically, the rack gear in which the lower end of the rack gear 57a is fixed to the side surface of the fixed platen 51 and the upper end side thereof is arranged on the side surface of the movable platen 52. It is arranged to be movable in the vertical direction via the guide 57b. The pinion gear 57c and the encoder 57e are disposed on the side surface of the fixed platen 51. Since the configuration of the mold thickness measuring means 57 is basically the same as that of the first embodiment (FIG. 4) except for the arrangement, refer to FIG. 4 of the first embodiment for understanding the arrangement. In the second embodiment as well, the mold thickness measuring means 57 is not shown in FIG.

  Next, the mold clamping cylinder 58 arranged for each tie bar 54, which is the biggest difference from the first embodiment in terms of the configuration requirements of the vertical mold clamping device of the vertical casting machine according to the second embodiment of the present invention. This will be described with reference to FIGS. 6B and 7. As shown in FIG. 6B, in the vertical mold clamping device 50 ′ according to the second embodiment, a mold clamping cylinder 58 is arranged for each of the four tie bars 54. FIG. 6B is a view (plan view) taken along the arrow F in FIG. FIG. 7 is a view (sectional view) taken along arrow G in FIG.

  As shown in FIG. 7, the mold clamping cylinder 58 basically includes a mold clamping piston 58a, an engaging means 59, and a space between the inside of the movable platen 52 into which the mold clamping piston 58a is inserted and the mold clamping piston 58a. The upper oil chamber 58b and the lower oil chamber 58c are formed. The mold clamping piston 58a penetrates the tie bar 54 and is slidable in the axial direction of the tie bar 54 (in other words, the tie bar 54 is slidable in the longitudinal direction of the mold clamping piston 58a). A large-diameter portion 58d is formed at the approximate center, and the upper oil chamber 58b is located above the large-diameter portion 58d and the lower oil chamber 58c is located below the large-diameter portion 58d with the clamping piston 58a inserted into the movable platen 52. It is formed. The upper end of the mold clamping piston 58a protrudes from the upper surface of the movable platen 52, and the engaging means 59 is disposed at the protruding end.

  In a state where the upper die 61 is matched with the lower die 60, continuous irregularities are processed in a predetermined range of the outer peripheral surface of the tie bar 54 that penetrates the clamping piston 58a and penetrates the region of the engaging means 59. An engaging groove portion 54a is formed. The outer diameter of the convex portion of the engaging groove portion 54a does not exceed the outer diameter of the tie bar 54 in which the engaging groove portion 54a is not formed, and there is no problem with the relative sliding of the mold clamping piston 58a and the penetrating tie bar 54. Absent. The engagement means 59 disposed at the protruding end portion of the upper end of the mold clamping piston 58a includes a movable engagement groove portion 59a in which unevenness combined with continuous unevenness of the engagement groove portion 54a of the tie bar 54 is processed, and a movable engagement It is comprised by the groove part drive means 59b and the base 59c in which these are arrange | positioned. In FIG. 7, the movable engagement groove portion 59a disposed so as to face the engagement groove portion 54a of the tie bar 54 is advanced and retracted by the movable engagement groove portion driving means 59b, whereby the engagement groove portion 54a and the movable engagement groove portion 54a are moved forward. The mating groove 59a can be engaged and released.

  The form of the engaging means 59 is not limited to the above form. For example, the engaging groove portion 54a of the tie bar 54 is formed with unevenness or threading that is continuous on the entire circumference in the vicinity of the engaging means 59, and a nut-like member in which the unevenness combined therewith is processed on the entire inner periphery is centered on the inner diameter. The one divided into two is referred to as a movable engagement groove 59a. One of the divided surfaces may be connected by a hinge, and the other may be opened and closed by a single movable engagement groove drive means 59b via a link structure or the like so that it can be opened in a C shape. Such a structure is employed as a positioning mechanism (also referred to as a nut splitting device or a half nut) of an end platen (also referred to as a link housing) of a horizontal casting machine having a toggle type clamping device. .

  Next, the operation of the mold clamping cylinder 58 will be described with reference to FIG. In FIG. 7, the right side of the engaging means 59 shows a state where the engaging groove portion 54a and the movable engaging groove portion 59a are engaged, and the left side shows a state where the engagement is released. When the movable plate 52 is lowered by the mold opening / closing cylinder 56 in order to match the upper mold 61 with the lower mold 60, the engagement of the engagement groove 54a and the movable engagement groove 59a is released (FIG. 7). The left side of the engagement means 59 is lowered). At this time, if the hydraulic pipes (not shown) to the upper oil chamber 58b and the lower oil chamber 58c of the mold clamping cylinder 58 are closed, the movement of the mold clamping piston 58a and the engagement means 59 relative to the movable platen 52 is suppressed, The fastening piston 58a, the engaging means 59, and the movable platen 52 can be lowered integrally.

  After the upper die 61 is matched with the lower die 60, the movable engagement groove 59a of the engagement means 59 is advanced by the movable engagement groove drive means 59b to engage the engagement groove 54a and the movable engagement groove 59a. (Right side of the engaging means 59 in FIG. 7). Here, before engaging the engaging groove portion 54a and the movable engaging groove portion 59a, the mold thickness of the mold is confirmed by the mold thickness measuring means 57 in a state where the upper mold 61 is aligned with the lower mold 60. Is preferred. This is due to the chattering of the movable plate lowering due to the entry of contaminants such as aluminum debris and cast pieces on the mold mating surface, and the wear of the bushing of the sliding part (not shown). This is to prevent the mold clamping force from being applied in a state where 61 is on the upper side.

  In a state where the engaging groove portion 54 a and the movable engaging groove portion 59 a are engaged (on the right side of the engaging means 59 in FIG. 7), the mold clamping piston 58 a is integrated with the tie bar 54 via the engaging means 59. In this state, if a hydraulic pipe (not shown) to the upper oil chamber 58b of the mold clamping cylinder 58 is opened and hydraulic oil with a predetermined pressure is supplied to the lower oil chamber 58c via a hydraulic pipe (not shown), for example, The mold mounting surface of the movable platen 52 descends to the position indicated by the two-dot chain line with reference to the mold clamping piston 58a integrated with the tie bar 54, and the predetermined pressure of the supplied hydraulic oil and the tie bar 54 in this state A mold clamping force according to the amount of elongation is applied to the upper mold 61 and the lower mold 60. In the second embodiment, it goes without saying that hydraulic control to the upper oil chamber 58 b and the lower oil chamber 58 c of the mold clamping cylinder 58 can be performed for each mold clamping cylinder 58.

  Thus, in the vertical mold clamping device 50 ′ in which the mold clamping cylinder 58 is arranged for each tie bar 54, the nearest mold clamping force generating means combined with the mold thickness measuring means 57 as in the first embodiment (this embodiment). In Example 2, if the clamping pressure is controlled independently for each clamping cylinder 58), each clamping force is set individually by the clamping cylinders 58 arranged at the four corners of the movable platen 52. Since the clamping force can be controlled, the mold opening / closing cylinder 56 is utilized as an auxiliary actuator for increasing / decreasing the clamping force, thereby preventing an increase in the mold thickness of the mold and the upper mold 61 relative to the lower mold 60. Mold clamping control (mold clamping pressure control) for maintaining parallelism is further facilitated. In addition, regarding the portion of the mold clamping control method according to the second embodiment that overlaps with the mold clamping control method according to the first embodiment, the difference in the mold clamping force generating means that is a constituent element (the first embodiment: mold opening / closing cylinder 56). Example 2: Since there is only the mold clamping cylinder 58), a detailed description is omitted.

  In the second embodiment, by making use of the high controllability of the above mold clamping pressure control, not only the mold thickness difference A for each mold thickness measuring means 57 but also the difference A for each mold thickness measuring means 57 is compared. The difference D is compared.

  Specifically, the difference D of the difference A between the two adjacent mold thickness measurement means 57 or the difference A of the difference A between the two mold thickness measurement means 57 symmetrical to the center point of the mold mounting surface of the movable platen 52. D is compared with a mold thickness difference allowable range E stored in the control device in advance. The mold thickness difference allowable range E is different from the mold thickness maintenance allowable range B and is an allowable range for directly controlling the parallelism of the upper mold 61 with respect to the lower mold 60. Therefore, a different range may be set for the difference D of the difference A between the two adjacent mold thickness measurement means 57 and the difference D of the difference A between the two mold thickness measurement means 57 that are symmetrical about the same vertical axis. .

  In parallel with the comparison between the difference A and the mold thickness tolerance range B, the difference D and the mold thickness difference tolerance range E are compared, resulting in a state where the difference D exceeds the mold thickness difference tolerance range E. In this case, the mold clamping force correction start point 2 is set as that point, and the mold clamping control method according to the second embodiment is executed. When the occurrence of the mold clamping force correction starting point 2 is recognized, the nearest mold clamping cylinder 58 (mold clamping force generating means) of each of the two (one set) mold thickness measuring means 57 related to the difference D is applied. Clamping force adjustment (preliminary clamping pressure) is set to the clamping force (mold clamping pressure) according to the mold clamping pressure increase curve at the mold clamping force correction start point 2. Increase or decrease within the range C. As in the first embodiment, if the difference D deviates from the mold thickness difference allowable range E at the mold alignment position (injection start) shown in FIG. 9, the mold clamping force correction start point 2 is recognized, and this The mold clamping control method according to the second embodiment is performed.

  Maintaining the difference D within the mold thickness difference allowable range E means that the difference A, which is the difference in mold thickness between the cold state and the cast state of the mold thickness measuring means 57 at one location, is set to the mold thickness allowable range B. It is different from making it maintain. That is, since the difference regarding the difference A between the two mold thickness measuring means 57 is eliminated, the smaller difference A increases (the mold) together with the larger difference A decreases (the mold clamping pressure increases). (Reduction of tightening pressure) is effective for control. In the latter case, these controls are performed while maintaining the increase in the difference A within the mold thickness tolerance B by reducing the mold clamping pressure of the mold clamping cylinder 58 nearest to the corresponding mold thickness measuring means 57. .

  As described above, the vertical mold clamping apparatus and the mold clamping control method of the vertical casting machine according to the second embodiment are similar to the first embodiment in that the heat of the mold is monitored by monitoring the difference A for each mold thickness measuring means 57. Increase in mold thickness due to expansion, i.e., prevention of increase in gap between mold mating surfaces is facilitated. The actually measured mold clamping pressure can easily reach the pressure increase confirmation mold clamping force. Moreover, since the parallelism of the upper mold | type with respect to a lower mold | type is actively maintained by monitoring the difference D of the difference A, the hot water spill and the burr | flash from a metal mold | die fitting surface can be prevented easily.

  Note that such mold clamping pressure control for maintaining the difference D within the mold thickness difference allowable range E is possible even in the form in which the mold clamping force generating means is the mold opening / closing cylinder 56 as in the first embodiment. As in the second embodiment, it is more preferable if two sets (four pieces) of the mold opening / closing cylinder 56 and the mold thickness measuring means are arranged. Further, in the form of the second embodiment, the mold clamping pressure related to the difference A and the difference D can be controlled by the mold opening / closing cylinder 56. In this case, if the mold clamping pressure control related to the difference A and the difference D is performed by the mold opening / closing cylinder 56 and the mold clamping cylinder 58, the controllability of the mold clamping pressure can be further improved. .

  The present invention is not limited to the above embodiment and can be implemented in various forms. For example, a vertical casting machine includes a casting machine called a shuttle type or the like, in which a vertical mold clamping device having an injection device and a mold opening / closing device are independent. Specifically, a plurality of mold opening / closing devices provided with a mold mounting board to which a mold is attached and an opening / closing means for the same board are installed in a saddle mold clamping apparatus exclusively for mold clamping via a rail or the like. This is a vertical casting machine configured to be able to carry in alternately. A mold opening / closing device with the mold in a mold-matched state is carried into the vertical mold clamping device for casting, and outside the vertical mold clamping device, it is carried into the vertical mold clamping device in the previous casting cycle. Another mold opening / closing device that had been cast is taken out of the vertical mold clamping device via the rail, opened, and then the cast product is taken out of the die. A mold release agent is applied to the mold cavity or an insert part is set to prepare for the next casting. Thus, in the shuttle type vertical casting machine, casting can be performed in parallel with product removal before and after casting, application of a release agent, and the like.

  The mold clamping cylinder of such a shuttle type vertical casting machine is either in the form of a mold clamping ram cylinder as in the first embodiment or in the form of a mold clamping cylinder arranged for each tie bar as in the second embodiment. However, there is no problem in carrying out the mold clamping control method according to the present invention in the shuttle type vertical casting machine.

50 Vertical clamping device 50 'Vertical clamping device 51 Fixed platen 52 Movable platen 54 Tie bar 56 Open / close cylinder 56a Cylinder body 56b Cylinder rod 57 Mold thickness measuring means 57a Rack gear 57c Pinion gear 57e Encoder 58 Mold clamping cylinder 58a Mold clamping piston 58b Upper oil chamber 58c Lower oil chamber 58d Large diameter portion 59 Engaging means 60 Lower mold 61 Upper mold

Claims (8)

From the state in which the upper mold and the lower mold are combined with the lower mold, the filling of the molten metal into the mold cavity formed in the mold is started,
Before the molten metal in the mold cavity reaches the mold mating surface of the mold, application of a mold clamping force to the mold is started based on a preset mold clamping pressure curve, and a set mold In a vertical mold clamping device of a vertical casting machine in which a two-stage mold clamping control method for increasing pressure to a clamping force is performed,
A plurality of mold clamping force generating means arranged separately from the center point of the mold mounting surface of the mold mounting board and capable of individually controlling each mold clamping force;
A mold thickness measuring means which is disposed at at least two positions symmetrical with respect to the center of the mold mounting surface of the mold mounting board, and is capable of measuring the mold thickness of the mold at the disposed portion;
A vertical mold clamping device for a vertical caster.   The vertical mold clamping device of the vertical casting machine according to claim 1, wherein the mold clamping force generating means is a mold opening / closing cylinder different from the mold clamping cylinder.   The mold clamping force generating means is disposed at one end of the mold clamping piston, penetrating the tie bar and slidable in the axial direction of the tie bar, and engaging the mold clamping piston and the tie bar. And a clamping means comprising: an engaging means for releasing the engagement; and an oil chamber formed between the inner space of the mold mounting plate on the side where the clamping piston is inserted and the clamping piston. The vertical mold clamping device of the vertical casting machine according to claim 1, which is a cylinder. The mold thickness measuring means is
A rack gear disposed between the mold mounting board to which the upper mold is mounted and a fixing member that fixes either the upper or lower end of the tie bar;
A pinion gear combined with the rack gear;
An encoder that detects a rotation angle of the pinion gear;
The vertical mold of the vertical casting machine of any one of Claims 1 thru | or 3 which can calculate the distance between the said mold mounting surfaces of the site | part arrange | positioned from the said rotation angle of the said pinion gear. Fastening device. The saddle mold according to any one of claims 1 to 3, wherein the mold thickness measuring means is a non-contact type distance sensor capable of measuring a distance between the mold mounting surfaces of an arranged portion. Casting machine vertical mold clamping device. A mold thickness 1 in which the upper mold is matched with the lower mold in the cold state before the start of casting, and a state in which the upper mold is matched with the lower mold in the hot state after the start of casting The mold thickness 2 is compared for each mold thickness measuring means, and in at least one of the mold thickness measuring means, the difference A between the mold thickness 1 and the mold thickness 2 indicates that the molten metal is from the mold mating surface. A point that deviates from a mold thickness tolerance range B set in advance as a reference for maintaining the gap between the mold mating surfaces that does not leak is set as a mold clamping force correction start point 1.
At the mold clamping force correction start point 1, the mold clamping force of the mold clamping force generating means closest to the mold thickness measuring means where the difference A deviates from the mold thickness tolerance B is the mold clamping force correction start. The mold clamping force according to the mold clamping pressure increase curve at point 1 is increased or decreased within a mold clamping force adjustment range C set in advance as a reference for determining that the apparatus is abnormal due to factors other than thermal expansion of the mold. ,
At the mold clamping force correction start point 1, the difference A deviating from the mold thickness allowable range B is maintained in the mold thickness allowable range B at least by the position of confirmation of mold clamping pressure increase during filling.
A mold clamping control method in the vertical mold clamping device of the vertical mold casting machine according to any one of claims 1 to 5. The difference A for each of the mold thickness measuring means is compared, and the difference D between the two differences A of the mold thickness measuring means directly controls the parallelism of the upper mold with respect to the lower mold to match the mold. A point that deviates from a mold thickness difference allowable range E set in advance as a reference for preventing spilling or flashing of burr from the surface is a mold clamping force correction start point 2,
At the mold clamping force correction start point 2, the mold clamping force of the mold clamping force generating means closest to the mold thickness measuring means at two locations where the difference D deviates from the mold thickness difference allowable range E is expressed as the mold clamping force. The mold clamping force according to the mold clamping pressure increase curve at the clamping force correction start point 2 is increased or decreased within the preset mold clamping force adjustment range C, respectively.
At the mold clamping force correction start point 2, the difference D deviating from the mold thickness difference allowable range E is maintained in the mold thickness difference allowable range E at least by the position of the mold clamping pressure increase confirmation during filling.
The mold clamping control method according to claim 6.   Even if the mold clamping force of the mold clamping force generating means is increased or decreased within the mold clamping force adjustment range C, the difference A is maintained in the mold thickness allowable range B at least by the position of the mold clamping pressure increase confirmation during filling. The mold clamping control method according to any one of claims 6 and 7, wherein if not, filling of the molten metal is stopped.

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