JP5731922B2 - Molten metal supply method and apparatus - Google Patents

Description

  The present invention relates to a molten metal supply method and apparatus for supplying a molten metal to a mold cavity.

  Conventionally, in a vacuum die casting apparatus, it is known that a molten metal accommodated in a holding furnace is sucked from a hot water supply pipe and loaded into an injection sleeve, and then a plunger of the injection sleeve is advanced to inject the molten metal into a mold cavity. (See Patent Document 1). The mold cavity is depressurized by depressurizing means such as a vacuum pump. Along with this, the inside of the injection sleeve communicating with the mold cavity is also depressurized, and the molten metal in the holding furnace is sucked into the injection sleeve through the hot water supply pipe by the suction force at this time.

  Although the amount of the molten metal sucked into the injection sleeve can be controlled by the suction time by the pressure reducing means, it is desired to supply the molten metal to the injection sleeve without excess or deficiency corresponding to the volume of the mold cavity. Therefore, a level sensor for measuring the molten metal surface height in the holding furnace, a weight sensor for measuring the weight of the molten metal in the holding furnace, and a temperature sensor for detecting the temperature of the molten metal in the holding furnace are provided and injected. The accuracy of hot water supply to the sleeve is improved.

  That is, the amount of change in the molten metal in the holding furnace reduced by the supply of the molten metal to the injection sleeve is detected by the level sensor or the weight sensor, and the amount of the molten metal supplied to the injection sleeve is grasped from the detected change amount. . Further, the viscosity of the molten metal is obtained from the temperature of the molten metal in the holding furnace, and the viscosity of the molten metal is reflected in the suction time of the decompression means to control the amount of hot water supplied to the injection sleeve.

JP 2001-79654 A

  However, if the amount of hot water supplied to the injection sleeve is controlled by the suction time of the pressure reducing means, the desired amount of hot water may not be obtained due to the influence of atmospheric pressure, fluctuations in the suction force of the pressure reducing means, and the like. Even if the level sensor and the weight sensor are provided, when the volume of the mold cavity is relatively small, it is difficult to detect these because the amount of change in the molten metal surface position and weight accompanying the hot water supply is small. . Furthermore, even if the temperature sensor is provided to obtain the viscosity from the temperature of the molten metal to improve the accuracy of the suction time of the decompression means, the molten metal in the holding furnace not only has a temperature difference depending on the position, but also the molten material ( Since the relationship between temperature and viscosity varies depending on the components, etc., there is a possibility that the accurate viscosity cannot be grasped.

  As described above, in the conventional one, not only is the control complicated by providing a plurality of sensors, but also sufficient accuracy cannot be obtained even if a plurality of sensors are used. There are inconveniences that cannot be made.

  In view of the above-described points, an object of the present invention is to provide a molten metal supply method and apparatus capable of controlling the amount of hot water supply with high accuracy by simplifying the configuration.

In order to achieve such an object, the molten metal supply method of the present invention is a molten metal supply method for supplying a molten metal to a mold cavity, wherein the downstream end is connected to an injection sleeve that communicates with the mold cavity. Closing the hot water supply pipe by closing a hot water supply pipe immersed in the molten metal of the holding furnace containing the molten metal by closing an on-off valve provided at the upstream end of the hot water supply pipe, and closing the hot water supply pipe in state, a depressurizing step of depressurizing the hot water space formed by the cavity and the injection sleeve, reducing the first pressure value the pressure of the hot water space is measured by the pressure sensor by the depressurization step is set in advance A decompression stop step of stopping decompression and maintaining the hot water supply space in a decompressed state, and a target based on a relationship between a preset target hot water supply amount, the volume of the hot water supply space, and the first pressure value. Hot water supply A calculation step of calculating a second pressure value that is the pressure of the hot water supply space at the time of becoming, and opening the on-off valve of the hot water supply pipe while holding the hot water supply space in a reduced pressure state, and injecting the reduced pressure state A molten metal loading step of loading the molten metal of the holding furnace into the sleeve;
When the pressure of the fed-water space to be measured by the solution hot water loading step the volume the pressure sensor with the decrease of the hot water supply space due has returned to a second pressure value calculated by said calculation step, opening and closing of the hot water supply pipe It is characterized by comprising a loading stop step for closing the valve to stop the loading of the molten metal into the injection sleeve, and an injection step for injecting the molten metal loaded in the injection sleeve into the mold cavity.

  According to the method of the present invention, the on-off valve at the upstream end of the hot water supply pipe is closed (blocking step), and then the hot water supply space is depressurized (depressurization step). Since the hot water supply space is depressurized while the hot water supply pipe is closed, the suction of the molten metal to the injection sleeve is not performed, and the inside of the injection sleeve has a negative pressure. Then, when the hot water supply space decreases to the first pressure value, the depressurization of the hot water supply space is stopped (decompression stop process). Thereby, the internal pressure of the injection sleeve is maintained at the first pressure value.

  Next, the on-off valve at the upstream end of the hot water supply pipe is opened. At this time, due to the negative pressure in the injection sleeve, the molten metal in the holding furnace is sucked up into the injection sleeve through the hot water supply pipe (molten metal loading step). The suction of the molten metal at this time is not directly sucked by a suction force generated from a decompression means such as a vacuum pump. Therefore, the pressure in the injection sleeve when sucking up the molten metal is not affected by fluctuations in the atmospheric pressure or the suction force of the decompression means, and the molten metal is stably sucked up into the injection sleeve.

  When molten metal is loaded into the injection sleeve, the hot water supply space including the injection sleeve is gradually narrowed. That is, while the amount of the molten metal supplied to the injection sleeve increases, the volume of the hot water supply space decreases. And as the volume of the hot water supply space decreases, the pressure of the hot water supply space gradually returns, so that the hot water supply space changes in an increasing direction from the first pressure value.

  Thereafter, when the hot water supply space increases (returns) to the second pressure value, the on-off valve of the hot water supply pipe is closed. Thereby, the supply of the molten metal into the injection sleeve is stopped, and the charging of the molten metal into the injection sleeve is completed (loading stop process).

  The second pressure value is calculated by the calculation step. The second pressure value calculated by the calculation step corresponds to the target hot water supply amount to the hot water supply space (inside the injection sleeve). That is, when the molten metal is drawn into the hot water supply space by the internal pressure (negative pressure) of the hot water supply space into the hot water supply space where the internal pressure is equal to the first pressure value, the internal pressure of the hot water supply space increases (returns) corresponding to the amount of the molten metal. To do. Based on this, the pressure value in the hot water supply space when the target hot water supply amount is reached can be calculated as the second pressure value. Then, when the hot water supply space returns to the second pressure value, it is considered that the molten metal in the injection sleeve has reached the target hot water supply amount, and the supply of the molten metal to the hot water supply space is stopped. By doing so, the amount of the molten metal loaded in the injection sleeve can be matched with the target hot water supply amount to the mold cavity with high accuracy.

  As described above, according to the present invention, the amount of molten metal supplied to the mold cavity can be accurately controlled based on the internal pressure of the hot water supply space.

In order to achieve the above object, the supply how the molten metal of the present invention is a method of supplying molten supplying molten metal into the mold cavity, closing valve of the hot water supply pipe to a hot water supply space as air release state The hot water pipe is opened by opening the hot water pipe, and the hot water pipe opening process for matching the molten metal surface height in the holding furnace with the molten metal surface height in the hot water pipe, and the molten metal surface height in the holding furnace A molten metal surface level measuring step for measuring the molten metal surface height in the holding furnace in a state where the molten metal surface height in the hot water supply pipe is matched, and an upstream end connected to an injection sleeve communicating with the mold cavity Closing the hot water supply pipe by closing a hot water supply pipe immersed in the molten metal of the holding furnace containing the molten metal by closing an on-off valve provided at the upstream end of the hot water supply pipe, and closing the hot water supply pipe Formed with the cavity and the injection sleeve. A depressurization step of depressurizing the hot water supply space, and a depressurization stop step of stopping the depressurization and maintaining the hot water supply space in a depressurized state when the hot water supply space is reduced to a preset first pressure value by the depressurization step; wherein the correction step of correcting the volume of the hot water supply space based on molten metal surface level of the molten metal in the holding furnace measured by the melt-surface measuring step, predetermined target hot-water supply amount and volume of the hot water space first A calculation step of calculating a second pressure value, which is a pressure of the hot water supply space when the target hot water supply amount is reached, based on the relationship with the pressure value of 1, and the hot water supply by maintaining the hot water supply space in a reduced pressure state A molten metal loading step of opening the open / close valve of the pipe and loading the molten metal of the holding furnace into the injection sleeve in a depressurized state; The second calculated by the calculation process When returning to the pressure value, a loading stop step of closing the on-off valve of the hot water supply pipe to stop the filling of the molten metal into the injection sleeve, and injecting the molten metal loaded in the injection sleeve into the mold cavity characterized in that it comprises an exit step.

  By providing the correction step, it is possible to correct the volume of the hot water space used in the calculation step by adding the internal space of the hot water pipe to the hot water space, and to further improve the supply accuracy of the molten metal to the injection sleeve. it can.

The molten metal supply device according to the present invention includes an injection sleeve for injecting a molten metal loaded therein into a mold cavity by advancement of a plunger, a holding furnace for containing the molten metal loaded in the injection sleeve, and the holding furnace In the molten metal supply apparatus, comprising: a hot water supply pipe whose upstream end is immersed in the molten metal and whose downstream end is connected to the injection sleeve; and a decompression means for decompressing the hot water space formed by the cavity and the injection sleeve. An on-off valve that opens and closes an upstream end of the hot water supply pipe, a pressure measuring means that measures the pressure of the hot water space, and the pressure measuring means that depressurizes the hot water space with the pressure-reducing means with the on-off valve closed. Pressure reduction control means for stopping the pressure reduction of the hot water supply space by the pressure reduction means when the measured pressure by the pressure decreases to a preset first pressure value; Calculating means for calculating a second pressure value that is a pressure of the hot water supply space when the target hot water supply amount is reached based on a relationship between an amount, a volume of the hot water supply space, and the first pressure value; after vacuum in a state in which the measured pressure by the pressure measuring means becomes the first pressure value is stopped by means to open the on-off valve, pressure values of the measured pressure is first by said pressure measuring means And a hot water supply control means for closing the on-off valve when the pressure returns to the second pressure value.

  The apparatus of the present invention can open and close the hot water supply pipe at a desired timing by providing the on-off valve. Furthermore, the apparatus of this invention can grasp | ascertain the pressure change of hot water supply space correctly now by providing the said pressure measurement means.

  In the apparatus of the present invention, first, the on-off valve and the pressure reducing means are controlled by the pressure reducing control means to reduce the hot water supply space to the first pressure value. Thereby, the hot water supply space is set to a negative pressure. Next, the on-off valve is controlled by the hot water supply control means, and the molten metal is supplied until the hot water supply space returns to the second pressure value. The supply of the molten metal at this time is performed by a suction force due to the negative pressure in the hot water supply space.

  The second pressure value used by the hot water supply control means is a value calculated by the calculation means based on a preset target hot water supply amount, a volume of the hot water supply space, and the first pressure value. Therefore, the second pressure value corresponds to the target hot water supply amount to the hot water supply space (in the injection sleeve), and the hot water supply control means controls the hot water supply into the injection sleeve based on the second pressure value. The amount of the molten metal loaded in the injection sleeve can be matched with the target amount of hot water supplied to the mold cavity with high accuracy.

In order to achieve the above object, the supply equipment of the molten metal of the present invention, an injection sleeve is injected into the mold cavity the molten metal loaded inside the advancement of the plunger, the molten metal is loaded into the injection-sleeve A holding furnace to be stored; a hot water supply pipe whose upstream end is immersed in the molten metal of the holding furnace and whose downstream end is connected to the injection sleeve; and a pressure reducing means for decompressing a hot water supply space formed by the cavity and the injection sleeve; An on-off valve for opening and closing an upstream end of the hot water supply pipe, a pressure measuring means for measuring the pressure of the hot water supply space, and the hot water supply by the pressure reducing means with the on-off valve closed. Decompression control for depressurizing the space and stopping depressurization of the hot water supply space by the depressurization means when the pressure measured by the pressure measurement means decreases to a preset first pressure value A second pressure value that is a pressure of the hot water supply space when the target hot water supply amount is reached based on a relationship between the stage, a preset target hot water supply amount, a volume of the hot water supply space, and the first pressure value. The calculating means for calculating, the molten metal level measuring means for measuring the molten metal surface height of the molten metal in the holding furnace, and the calculating means based on the molten metal surface height in the holding furnace measured by the molten metal surface measuring means. And a correction means for correcting the volume of the hot water supply space used by the control device, and after the pressure reduction is stopped by the pressure reduction control means with the hot water supply space at the first pressure value, the on-off valve is opened, characterized in that the first pressure value and a hot water supply control means for closing said opening and closing valve when returning to the second pressure value.

  By providing the correction means, the internal space of the hot water supply pipe is added to the hot water supply space, the volume of the hot water supply space used when the calculation means calculates the second pressure value can be corrected, and the hot water supply to the injection sleeve can be corrected. The accuracy can be further improved.

Cross-sectional explanatory drawing which shows schematic structure of embodiment of this invention. The flowchart which shows the supply method of the molten metal in this embodiment. The diagram which shows the pressure change of hot water supply space. Explanatory drawing which shows the supply operation | movement of the molten metal of this embodiment. Explanatory drawing which shows the principal part of a metal mold | die.

  An embodiment of the present invention will be described with reference to the drawings. The molten metal supply device of this embodiment is provided as a part of a die casting device for casting a metal product.

  As shown in FIG. 1, the die casting apparatus includes a fixed mold 2 and a movable mold 3 that constitute a mold 1. The movable mold 3 is provided so as to be separated from the fixed mold 2 and is pressed against the fixed mold 2 by a driving device (not shown). A cavity 4 having a molding surface corresponding to the product shape as an inner wall is formed inside the movable mold 3 and the fixed mold 2 that are in pressure contact with each other. The cavity 4 is opened when the movable mold 3 is separated from the fixed mold 2. The opening of the cavity 4 is mainly performed when the product is removed.

  The supply device includes an injection sleeve 5 attached to the fixed mold 2, a holding furnace 7 for storing the molten metal 6 below the injection sleeve 5, one end (downstream end) connected to the injection sleeve 5, and the other end (upstream). The end) is provided with a hot water supply pipe 8 that immerses in the molten metal 6 of the holding furnace 7 and a controller 9.

  The injection sleeve 5 includes a plunger 10 whose tip communicates with the cavity 4 and moves back and forth in the longitudinal direction. The plunger 10 is driven by a driving device (not shown) to perform a forward / backward movement.

  The holding furnace 7 is provided with a level sensor 11 (melt level measuring means) that detects the level of the molten metal 6 contained therein. The level sensor 11 is electrically connected to the controller 9 and outputs a detection signal indicating the molten metal surface height to the controller 9.

  The hot water supply pipe 8 is provided with a hot water supply control valve 12 (open / close valve). The hot water supply control valve 12 moves the valve body 14 via the valve body 14 that opens and closes the opening 13 formed at the upstream end of the hot water pipe 8, the support arm 15 that supports the valve body 14, and the support arm 15. And a valve moving means 16 for opening and closing the opening 13. The valve moving means 16 is electrically connected to the controller 9 and opens and closes the hot water supply pipe 8 by the valve body 14 in accordance with an instruction signal from the controller 9.

  On the other hand, a vacuum pump (decompression unit) (not shown) is connected to the cavity 4 via an intake pipe 17. The vacuum pump evacuates and depressurizes the cavity 4. An electromagnetic pressure reduction control valve 18 is provided in the intake pipe 17 between the cavity 4 and the vacuum pump. The decompression control valve 18 is electrically connected to the controller 9 and opens and closes the intake pipe 17 in accordance with an instruction signal from the controller 9. When the decompression control valve 18 is open, the cavity 4 is decompressed, and when the decompression control valve 18 is closed, decompression of the cavity 4 is stopped.

  Further, a pressure sensor 19 (pressure measuring means) for measuring the internal pressure of the cavity 4 is provided between the cavity 4 and the pressure reducing control valve 18. The pressure sensor 19 is electrically connected to the controller 9 and outputs a detection signal indicating the internal pressure of the cavity 4 to the controller 9.

  The controller 9 is composed of an electronic circuit such as a computer, and is operated by the decompression control means 20 for controlling the decompression of the cavity 4, the calculation means 21 for calculating the pressure value used by the decompression control means, and the operation of the hot water supply control valve 12. A hot water supply control means 22 for controlling the supply of the molten metal 6 into the injection sleeve 5 and a correction means 23 for correcting the volume used by the calculation means 21 are functionally provided.

  Next, the hot water supply operation of the supply device under the control of the controller 9 will be described. In the following description, the space formed by the cavity 4, the space inside the injection sleeve 5, and the space inside the hot water supply pipe 8 is referred to as a hot water supply space 24.

  Referring to FIG. 2, first, controller 9 sets the supply device in a standby state in STEP1. During this time, the movable mold 3 is separated from the fixed mold 2 to release the previously molded product, to apply a release agent to the inner surface of the cavity 4, and to press the movable mold 3 against the fixed mold 2. At this time, as shown in FIG. 3, the pressure in the hot water supply space 24 measured by the pressure sensor 19 is atmospheric pressure.

  When the predetermined work performed in the standby state is completed, as shown in FIG. 2, the controller 9 proceeds to STEP 2 by the pressure reduction control means 20 to close the hot water supply control valve 12 (blocking process), and further proceeds to STEP 3. The depressurization of the hot water supply space 24 is started (decompression step). As a result, as shown in FIG. 4A, the valve body 14 closes the opening 13 of the hot water supply pipe 8 by driving the valve moving means 16 of the hot water supply control valve 12, and the pressure reduction control valve 18 is opened. At this time, as shown in FIG. 3, the pressure of the hot water supply space 24 measured by the pressure sensor 19 gradually decreases, but the molten metal 6 does not flow into the hot water supply space 24 by closing the hot water supply control valve 12.

Next, as shown in FIG. 2, the controller 9 proceeds to STEP 4, and the pressure in the hot water supply space 24 measured by the pressure sensor 19 via the pressure reduction control means 20 is set to a first pressure value P ₀ set in advance. The hot water supply space 24 is depressurized until Then, the pressure reduction control means 20 proceeds to STEP5 where pressure measured by the pressure sensor 19 becomes the first pressure value P _0, to stop the vacuum by closing the pressure reducing valve 18 (pressure reducing stopping step). Thereby, as shown in FIG. 3, the hot water supply space 24 is brought into a negative pressure state extremely lower than the atmospheric pressure.

Subsequently, as shown in FIG. 2, the controller 9 proceeds to STEP 6 to open the hot water supply control valve 12 via the hot water supply control means 22, and further proceeds to STEP 7 to determine the hot water supply space 24 measured by the pressure sensor 19. until the second pressure value P ₁ of the pressure will be described later, to keep the opening of the hot water supply control valve 12 (molten metal loading step).

  As shown in FIG. 4B, when the hot water supply control valve 12 is opened, the molten metal 6 in the holding furnace 7 is sucked into the injection sleeve 5 through the hot water supply pipe 8. As the molten metal 6 flows into the injection sleeve 5, the hot water supply space 24 becomes narrower and the internal pressure of the hot water supply space 24 increases as shown in FIG.

Thereafter, as shown in FIG. 2, the hot water supply control means 22 of the controller 9 proceeds to STEP 8 when the pressure measured by the pressure sensor 19 reaches the second pressure value P ₁ in STEP 7 and closes the hot water supply control valve 12. Then, the flow of the molten metal 6 into the injection sleeve 5 is stopped (loading stop process). Thus, the injection sleeve 5 that are part of a hot water space 24, the molten metal 6 in the amount of only corresponding to the second pressure value P ₁ is loaded.

  When the molten metal 6 is thus loaded in the injection sleeve 5, the controller 9 proceeds to STEP 9, advances the plunger 10 of the injection sleeve 5, and injects the molten metal 6 loaded in the injection sleeve 5 into the cavity 4. At this time, the controller 9 opens the decompression control valve 18 again to evacuate the cavity 4, prevents contact between the molten metal 6 and the atmosphere, suppresses oxidation of the molten metal 6 and entrainment of gas, and Casting.

  When the injection operation in STEP 9 is completed, the controller 9 returns to STEP 1 and makes the supply device stand by. In this standby state, the product is released, the plunger 10 of the injection sleeve 5 is retracted, etc., and preparation for the next casting is performed.

Here will be described the second for pressure value P _1. The second pressure value P _1, as shown in FIG. 1, but calculated by the calculation means 21 the controller 9 is provided. In calculating means 21 is set in advance the first pressure value P ₀ and the target hot-water supply amount Vm. The target hot water supply amount Vm is the amount of the molten metal 6 to be loaded into the injection sleeve 5 in the molten metal loading step described above, that is, the amount of the molten metal 6 corresponding to the volume of the cavity 4.

On the other hand, when the molten metal 6 is supplied to the hot water supply space 24, the volume Vcavi of the hot water supply space 24 before the molten metal 6 is supplied decreases. When the internal pressure of the volume Vcavi is the first pressure value P ₀ , when the molten metal 6 having the target hot water supply amount Vm is supplied to the hot water supply space 24, the remaining volume of the hot water supply space 24 becomes Vcavi−Vm. The internal pressure returns to the direction of increasing from the first pressure value P ₀ and becomes the second pressure value P ₁ . That is, the target hot-water supply amount Vm and the second pressure value P ₁ satisfies the relationship shown in equation (1).

Calculation means 21 of the controller 9 performs control by hot water supply control means 22 described above with reference second calculated pressure value P ₁ (the calculation step), the second pressure value P ₁ based on equation (1) . According to this, based on the measured pressure of the pressure sensor 19 (the return pressure of the hot water supply space 24 accompanying the supply of the molten metal 6), an amount of the molten metal 6 corresponding to the target hot water supply amount Vm is loaded into the injection sleeve 5 with high accuracy. can do. Moreover, the return pressure of the hot water supply space 24 accompanying the supply of the molten metal 6 corresponds to the change in the volume of the hot water supply space 24, and this change in volume does not vary depending on the type (component) of the molten metal 6. Highly accurate hot water supply control can be performed regardless of the type (component).

In the present embodiment, it is possible to controller 9 by providing the correcting means 23, calculating means 21 corrects the volume of the hot water space 24 which is used to calculate the second pressure value P _1.

That is, after performing the molten metal loading process, the molten metal 6 of the holding furnace 7 is supplied to the injection sleeve 5 as shown in FIG. Therefore, the controller 9 first measures the molten metal surface height by the level sensor 11 during the standby of STEP 1 in FIG. At this time, when the cavity 4 is opened by a product release operation or the like, the inside of the hot water supply pipe 8 becomes atmospheric pressure, and the hot water surface of the molten metal 6 in the holding furnace 7 and the hot water surface inside the hot water supply pipe 8 are the same. Position. Next, the controller 9 determines the volume of the space excluding the molten metal 6 in the hot water supply pipe 8 and the cavity based on the hot water level obtained from the level sensor 11 by the correcting means 23 (the hot water level inside the hot water supply pipe 8). 4 and the volume of the injection sleeve 5 are added to obtain the volume of the hot water supply space 24 (corrected volume). The correction means 23 passes the calculated correction volume calculating means 21, calculating means 21 calculates the second pressure value P ₁ by using the correction volume. By doing so, it is possible to eliminate the influence of the change in the molten metal surface of the molten metal 6 in the holding furnace 7 on the pressure value calculated by the calculating means 21, and to perform hot water supply control with higher accuracy.

  Although not shown, for example, the holding furnace 7 is provided with an elevating device, and the elevating device raises the holding furnace 7 in accordance with the lowering of the molten metal 6 so that the molten metal surface of the molten metal 6 is kept constant. In this case, the correcting unit 23 may not be provided.

  In the present embodiment, in order to prevent the molten metal from entering the intake pipe 17 from the cavity 4, the molten metal such as the shut-off valve 25 shown in FIG. 5A or the chill vent 26 shown in FIG. It is preferable to provide intrusion prevention means. When the shut-off valve 25 shown in FIG. 5A is used as the molten metal intrusion prevention means, during the hot water supply operation, the shut-off valve 25 is opened during the standby of STEP 1 in FIG. By closing the off valve 25, it is possible to reliably prevent the molten metal from entering the intake pipe 17.

  DESCRIPTION OF SYMBOLS 1 ... Mold, 4 ... Cavity, 5 ... Injection sleeve, 6 ... Molten metal, 7 ... Holding furnace, 8 ... Hot water supply pipe, 10 ... Plunger, 11 ... Level sensor (molten surface measuring means), 12 ... Hot water supply control valve (open / close) Valve), 19 ... pressure sensor (pressure measuring means), 20 ... pressure reduction control means, 21 ... calculation means, 22 ... hot water supply control means, 23 ... correction means, 24 ... hot water supply space.

Claims (4)

A molten metal supply method for supplying molten metal to a mold cavity,
Close the open / close valve provided at the upstream end of the hot water pipe for the hot water pipe immersed in the molten metal of the holding furnace whose downstream end is connected to the injection sleeve communicating with the mold cavity and the upstream end accommodates the molten metal. A closing step of closing the hot water supply pipe by:
A pressure reducing step for reducing the pressure of a hot water supply space formed by the cavity and the injection sleeve in a state where the hot water supply pipe is closed;
A depressurization stopping step of stopping the depressurization and holding the hot water supply space in a depressurized state when the pressure of the hot water supply space measured by the pressure sensor in the depressurization step decreases to a first pressure value set in advance;
Based on a preset target hot water supply amount, a volume of the hot water supply space, and the first pressure value, a second pressure value that is a pressure of the hot water supply space when the target hot water supply amount is reached is calculated. A calculation process;
A molten metal charging step of holding the hot water supply space in a reduced pressure state, opening the on-off valve of the hot water supply pipe, and charging the molten metal of the holding furnace into the injection sleeve in the reduced pressure state;
When the pressure of the fed-water space to be measured by the solution hot water loading step the volume the pressure sensor with the decrease of the hot water supply space due has returned to a second pressure value calculated by said calculation step, opening and closing of the hot water supply pipe A loading stop step of closing the valve to stop the filling of the molten metal into the injection sleeve;
An injection step of injecting the molten metal loaded in the injection sleeve into a mold cavity. A molten metal supply method for supplying molten metal to a mold cavity,
The hot water supply pipe opening process that opens the hot water supply pipe by opening the open / close valve of the hot water supply pipe with the hot water supply space open to the atmosphere, and matches the molten metal surface height in the holding furnace with the molten metal surface height in the hot water pipe. When,
A hot water surface measuring step for measuring the molten metal surface height of the molten metal in the holding furnace in a state in which the molten metal surface height of the molten metal in the holding furnace and the molten metal surface height of the molten metal in the hot water supply pipe are matched .
Close the open / close valve provided at the upstream end of the hot water pipe for the hot water pipe immersed in the molten metal of the holding furnace whose downstream end is connected to the injection sleeve communicating with the mold cavity and the upstream end accommodates the molten metal. A closing step of closing the hot water supply pipe by:
A pressure reducing step for reducing the pressure of a hot water supply space formed by the cavity and the injection sleeve in a state where the hot water supply pipe is closed;
When the hot water supply space is reduced to the first pressure value set in advance by the pressure reducing step, the pressure reduction stop step of stopping the hot water supply and holding the hot water supply space in a reduced pressure state;
A correction step of correcting the volume of the hot water supply space based on melt-surface height of the molten metal in the holding furnace measured by the melt-surface measuring step,
Based on a preset target hot water supply amount, a volume of the hot water supply space, and the first pressure value, a second pressure value that is a pressure of the hot water supply space when the target hot water supply amount is reached is calculated. A calculation process;
A molten metal charging step of holding the hot water supply space in a reduced pressure state, opening the on-off valve of the hot water supply pipe, and charging the molten metal of the holding furnace into the injection sleeve in the reduced pressure state;
When the hot water supply space returns to the second pressure value calculated by the calculation step as the volume of the hot water supply space decreases due to the molten metal loading step, the on-off valve of the hot water supply tube is closed and the injection sleeve A loading stop process for stopping the loading of the molten metal into the inside,
Soluble hot water supply method it anda injection step of injecting the molten metal is loaded into the injection sleeve into the mold cavity. An injection sleeve for injecting the molten metal loaded therein into the mold cavity by the advance of the plunger, a holding furnace for housing the molten metal to be loaded into the injection sleeve, and an upstream end immersed in the molten metal of the holding furnace A molten metal supply apparatus comprising: a hot water pipe connected to the injection sleeve; and a decompression means for decompressing a hot water space formed by the cavity and the injection sleeve.
An on-off valve for opening and closing the upstream end of the hot water pipe;
Pressure measuring means for measuring the pressure of the hot water supply space;
The hot water supply space is depressurized by the pressure reducing means in a state where the on-off valve is closed, and when the pressure measured by the pressure measuring means is reduced to a preset first pressure value, Decompression control means for stopping decompression;
Calculation for calculating a second pressure value that is a pressure of the hot water supply space when the target hot water supply amount is reached based on a relationship between a preset target hot water supply amount, a volume of the hot water supply space, and the first pressure value. Means,
After the pressure reduction is stopped in a state where the pressure measured by the pressure measuring means becomes the first pressure value by the pressure reducing control means, the on-off valve is opened, and the pressure measured by the pressure measuring means is the first pressure . And a hot water supply control means for closing the on-off valve when the pressure value returns to the second pressure value. An injection sleeve for injecting the molten metal loaded therein into the mold cavity by the advance of the plunger, a holding furnace for housing the molten metal to be loaded into the injection sleeve, and an upstream end immersed in the molten metal of the holding furnace A molten metal supply apparatus comprising: a hot water pipe connected to the injection sleeve; and a decompression means for decompressing a hot water space formed by the cavity and the injection sleeve.
An on-off valve for opening and closing the upstream end of the hot water pipe;
Pressure measuring means for measuring the pressure of the hot water supply space;
The hot water supply space is depressurized by the pressure reducing means in a state where the on-off valve is closed, and when the pressure measured by the pressure measuring means is reduced to a preset first pressure value, Decompression control means for stopping decompression;
Calculation for calculating a second pressure value that is a pressure of the hot water supply space when the target hot water supply amount is reached based on a relationship between a preset target hot water supply amount, a volume of the hot water supply space, and the first pressure value. Means,
A hot water surface measuring means for measuring the hot water surface height of the molten metal in the holding furnace,
Correction means for correcting the volume of the hot water supply space used by the calculating means based on the molten metal surface height of the molten metal in the holding furnace measured by the molten metal surface measuring means ;
After the depressurization is stopped in the state where the hot water supply space has reached the first pressure value by the depressurization control means, the on-off valve is opened, and the first pressure value is restored to the second pressure value. supply device soluble water anda hot water supply control means for closing said opening and closing valve when.

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