JPH04361869A - Method for controlling constant cycle supply of molten metal - Google Patents

Abstract

PURPOSE:To supply molten metal in the constant cycle while completing always the supply of molten metal as far as the safety is kept at the constant timing in casting in a casting machine by supplying the molten metal with the calculation and control of an air pressure molten metal-supplying furnace itself with a supplying command of the molten metal at the constant timing from the casting machine as the reference. CONSTITUTION:The time when the standard fill-up of holding quantity of the molten metal 2 in the air pressure molten metal-supplying furnace 1 is attained is taken as the basis of setting timing of pressurizing start with gas into the molten metal supplying furnace. Further, the actual cycle time cycle time for supplying the molten into the casting machine at every times is measured except the first supplying of molten metal after starting the operation for casting not after the temporary stopping of the operation, and the first supply of molten metal just after receiving the replenishment from an outer equipment because the holding quantity of molten metal 2 is reduced in the molten metal supplying furnace, and feedbacks the data of difference between the above measured actual cycle time and the actual cycle time at the previous time. Then, by quickening the pressurization of the molten metal supplying furnace with the gas pressure in the next time supply of molten metal corresponding to increase of the pressurizing time, the cycle time for casting in the casting machine, is corrected to stabilize the casting.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to control technology for pneumatic hot water supply furnaces that utilize pressurizing force from compressed gas used in foundries and the like.

0002

[Prior Art] Regarding pneumatic hot water furnaces that utilize compressed gas pressure and are used in foundries, etc., Japanese Patent Publication No. 51-
Various techniques including the technique shown in No. 36704 have been invented, devised, and put into practical use. However, in either case, the amount of pressurizing gas supplied to the pneumatic water heating furnace decreases, even if it is only slightly each time, due to the inevitable decrease in the amount of molten metal held in the pneumatic water heating furnace due to hot water supply. As a result, in order to supply the same amount of hot water, the elapsed time from the start of pressurizing the furnace to the completion of hot water supply becomes gradually longer.

However, due to technical requirements such as efficient production and strict temperature control of molds, there has been an increasing demand for casting in a fixed casting time commensurate with the capabilities of individual casting machines in recent years. There has been an increasing demand for supplying molten metal from a furnace to a casting machine at a constant timing. However, with the pressurization control of the conventional technology, it has been difficult to realize hot water supply at a constant timing.

0004

[Problems to be Solved by the Invention] Conventionally, attempts have been made to variously change the timing of issuing the hot water supply command to the casting machine in order to complete the hot water supply at as constant a timing as possible. Systems are becoming more and more general-purpose, and it is no longer possible to set the timing of hot water supply commands as freely and precisely as desired by pneumatic water heaters. Therefore, the problem to be solved by the present invention is to use the calculation and control of the pneumatic hot water furnace itself based on the hot water supply command from the casting machine at a certain timing, so that the casting machine can constantly operate the casting machine at certain timings as long as it does not violate safety. The objective is to realize fixed cycle hot water supply that can complete hot water supply.

[0005]

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described with reference to the accompanying drawings. FIG. 1 is a chart of a constant cycle hot water supply control method that comprehensively represents the concept of the present invention from claims 1 to 5. Prior to operation, two reference values are determined in advance: from the start of pressurization of the pneumatic water heating furnace with gas from an external pressurizing source to the metal pressure at a fixed point in the hot water pipe when the pneumatic water heating furnace is at the standard full holding amount of molten metal. Similarly to the reference value A, which is the elapsed time until the detection of molten metal, the start of pressurization of the pneumatic water heating furnace with gas from an external pressure source when the pneumatic water heating furnace is at the standard full holding amount of molten metal. A reference value B, which is a reference time for determining how much time should pass after receiving a hot water supply command from a casting machine, ie, a pressurization timing adjustment time, is input.

[0006] molten metal is replenished into the pneumatic water heating furnace until it is detected by a fullness sensor attached to the pneumatic water heating furnace;
Casting is started, and in response to the first hot water supply command from the casting machine, the pressurization timing adjustment timer in the control panel of the pneumatic hot water supply furnace starts, while a fixed value command is transmitted to the data value selection circuit and sent through the data transmission circuit. The subtraction fixed value (usually a zero value) is transmitted to subtractor B, which subtracts the subtraction fixed value from the reference value B, and the subtraction result (usually equal to the reference value B) is used as the setting value of the pressurization timing adjustment timer to adjust the pressurization timing. The values are transferred to the timer's numerical comparison section, where a numerical comparison is performed to determine the start of pressurization to the pneumatic water heating furnace, and the set value of the pressurization timing adjustment timer and the measured value of the pressurization timing adjustment timer are transferred. If they match, pressurization of the interior of the pneumatic hot water supply furnace with gas is started.

[0007] Simultaneously with the start of pressurization, a counter starts and measures the elapsed time until the hot water supply sensor detects the molten metal in the pneumatic hot water supply furnace rising in the hot water supply pipe. If molten metal is detected, the elapsed time data until the hot water sensor detects the molten metal is transferred to subtractor A, and the gas from the external pressurizing source to the pneumatic hot water furnace is inputted in advance. Subtract by the reference value A, which is the elapsed time from the start of pressurization to the detection of molten metal at a fixed point in the water supply pipe. If the result of this subtraction is positive, the data is transferred and input to the data transmission circuit as subtraction data of subtractor B for determining the set value for the next hot water supply of the pressurization timing adjustment timer.

If the result of this subtraction is negative, based on the characteristics of the casting machine, the negative subtraction data of subtractor B (that is, the addition is ), or even if there is a kind of difference between minus and plus in claim 2, a constant value is treated as a constant value in data transmission regardless of the negative absolute value of the subtraction result. In the case of claim 1, if the subtraction result is negative, zero is transmitted as a constant value.

After detection of molten metal, hot water supply is performed with high precision by controlling the amount of subsequent pressure increase and the time element after the stop of pressurization by gas, as in the conventional technology, and the hot water supply is completed at a certain time. Ru. In addition, those control methods are described in Japanese Patent Publication No. 51-36.
704, JP 63-40661, 63-33168, 6
1-33169, 63-165062, etc.

When the hot water supply is completed and the hot water supply command is received again from the casting machine, from next time onwards, the data value selection circuit selects the instruction for the received command, so as mentioned above, it is counted in the previous hot water supply and the subtracter The subtraction data that has been subtracted at point A and transferred and inputted to the data transmission circuit as the subtraction data of subtractor B for determining the set value of the pressurization timing adjustment timer is transferred from the data transmission circuit to subtractor B, and the reference value B is The set value of the pressurization timing adjustment timer is changed by subtracting from (or adding to) the water, and hot water is supplied so that the casting cycle of the casting machine is always performed in a regular cycle.

[0011] In this way, the supply of molten metal from the pneumatic water supply furnace to the casting machine is repeatedly started at a fixed timing of the casting cycle of the casting machine, and the pressurization of the pneumatic water supply furnace with gas is performed at a certain timing to complete the casting cycle of the casting machine. However, if there is an emergency stop due to some kind of abnormality or if the lid of the hot water inlet is opened for reasons such as inspection, no action will be taken as described in claims 4 and 5. When an emergency stop occurs due to an abnormality, and the reason for the emergency stop is resolved and the operation is restarted, or when the lid of the receiving spout is opened for reasons such as inspection, the lid of the receiving spout is opened by the receiving spout opening LS. For castings that are not after a temporary shutdown, during the first hot water supply immediately after the closure of the inlet lid is signaled by the inlet close LS. Similarly to the first hot water supply after the start of operation, the pneumatic water heating furnace is equated with the standard full holding amount of molten metal, and at the basic timing of setting the pressurization start timing with gas, the gas is supplied to the air pressure water heating furnace. Pressurization is started and hot water supply operation is performed.

Incidentally, as mentioned above, safety is taken into consideration in the cases of claims 4 and 5, but in practice, in the case of the embodiment shown in FIG. 3, which will be described later, the receiver shown in FIG. Since the sprue 10 is not used and hot water is received with the inspection port 21 open, when the inspection port 21 is open, the pressure inside the pneumatic hot water furnace does not change even if pressurization is performed with gas, and hot water cannot be supplied. This is not carried out, and even when restarting after an emergency stop, inspections are basically carried out on the safe side, so no problem will occur even if pressurization with gas is started at the basic timing.

[0013]

[Embodiment] Fig. 2 is an embodiment (part 2) of a constant cycle hot water supply control method chart according to the present invention. Conceptually, this is an embodiment in which claims 4 and 5 can be completely implemented. Example of fixed cycle hot water supply control method chart (
Part 1) is an embodiment showing the concept of a pneumatic hot water supply furnace having the most basic structure in which claims 1, 2, and 3 can be implemented. It should be noted that claim 1, which is the most basic configuration of the present invention, can of course be implemented in the embodiment shown in FIG.

An embodiment of the present invention shown in FIG. 3 will now be described. Molten metal 2 is replenished into the pneumatic hot water supply furnace 1 through the open inspection port cover 20 of the inspection port 21, and normally, when fullness is detected by the sensor 22, replenishment is stopped. When replenishment is stopped, the inspection port cover 20 is closed, and a data setter on the control panel (not shown) of the pneumatic water heating furnace is used to set two reference values, that is, the standard of the molten metal of the pneumatic water heating furnace. Similarly to the reference value A, which is the elapsed time from the start of pressurizing the pneumatic hot water supply furnace with gas from an external pressure source to the detection of molten metal at a fixed point in the hot water supply pipe when the amount is full, the pneumatic hot water supply furnace How much time should elapse after receiving the hot water supply command from the casting machine to start pressurizing the pneumatic hot water supply furnace with gas from an external pressure source when the furnace is at the standard full capacity of molten metal? When the reference value B, which is the reference time, that is, the pressurization timing adjustment time, is input, the pneumatic hot water supply furnace of this embodiment enters a state of waiting for a hot water supply command from the casting machine.

When a hot water supply command is transmitted from a casting machine (not shown) to a control panel (not shown) of the pneumatic hot water supply furnace 1, a pressurization timing adjustment timer in the control panel starts counting down. Since the operation has just started, the subtracted value of subtracter B to determine the setting value of the pressurization timing adjustment timer is selected by the data value selection circuit (usually zero) and is subtracted from the reference value B at the subtracter. The standard value (usually the reference value B itself) defined by the constant value is transferred as the set value of the pressurization adjustment timer, and the countdown of the pressurization adjustment timer is continued until the pressurization adjustment timer reaches the set value.

When the pressurization timing adjustment timer counts up, gas is started to be supplied into the pneumatic hot water supply furnace 1 from the external pressurization source 19 via the pressurization solenoid valve 16. Pressurizing solenoid valve 1 from the above-mentioned pressurizing source 19 to the pneumatic hot water supply furnace 1
When pressurization via 6 is started, the molten metal 2 held in the pneumatic hot water supply furnace 1 rises inside the hot water supply pipe 3. In parallel, a counter starts counting in a control panel (not shown) of the pneumatic water heating furnace, and the elapsed time of pressurizing the pneumatic water heating furnace with gas is measured. As the pneumatic hot water furnace continues to be pressurized with gas, the molten metal 2 flows through the hot water pipe 3.
continues to rise and is eventually detected by the hot water sensor 6 installed at the outlet 5 of the rising pipe. At this point, the value of the elapsed time of pressurization with gas measured by the counter is transferred to subtractor B.

When the value of the elapsed time of pressurization by gas measured by the counter is transferred to subtractor B, subtractor A
As a result, subtraction is performed using the reference value A that has been input in advance, and the subtraction result is positive, that is, the amount of molten metal 2 held in the pneumatic hot water supply furnace 1 is reduced from the standard full amount, and the gas enters the pneumatic hot water supply furnace 1. If the time from the start of pressurization until the molten metal 2 rises in the hot water supply pipe 3 and is detected by the hot water supply sensor 6 is getting longer, the subtraction result is used to set the pressurization timing adjustment timer for the next hot water supply. It is transmitted via the data transmission circuit as subtraction data of subtractor B for value determination. Even if the subtraction result is negative, that is, the amount of molten metal 2 held in the pneumatic hot water furnace 1 is greater than the standard full amount, the condition inside the furnace is visually inspected through the inspection port 21 when replenishing, so it is still the standard full amount. There is no danger in treating fixed values as the same as time.

As mentioned above, the hot water supply pipe 3 is detected by the hot water supply sensor 6.
After the molten metal 2 rising therein is detected at the outlet 10, the molten metal is supplied to the casting machine (in this embodiment, the die-casting machine sleeve 8) via the gutter 7. After this, the control for quantitative precision of the supply of molten metal to the casting machine is as follows:
3168, 61-33169, 63-165062, etc., the pressure increase amount control and pressurization after the molten metal 2 rising in the hot water supply pipe 3 is detected at the tap outlet 10 by the hot water supply sensor 6 This is done by time control after stopping.

When the hot water supply is completed and the hot water supply command is received again from the casting machine, from the next time onwards, the data value selection circuit will process the received command based on the control method of the present invention in the control panel (not shown) of the pneumatic hot water furnace. Since the instruction is selected, as mentioned above, it is counted in the previous hot water supply, subtracted by subtractor A, and transferred to the data transmission circuit as subtraction data of subtractor B for determining the set value of the pressurization timing adjustment timer.・Transfer the input subtraction data from the data transmission circuit to subtractor B, subtract it from the reference value B (or add it), change the setting value of the pressurization timing adjustment timer, and always perform the casting cycle of the casting machine in a regular cycle. Hot water is supplied so that the

Basically, when the casting is first started and
The reason why a fixed value is used as a subtraction value in determining the setting value of the pressurization timing adjustment timer in hot water supply immediately after receiving molten metal from external equipment is after the pressurization of the pneumatic hot water supply furnace 1 with gas is started. Immediately before the time required for the hot water supply sensor 6 to detect molten metal (even if hot water supply is stopped and a long time has elapsed, the previous data will be recognized as the previous data as long as the control circuit is not completely powered off). ), it is inevitable that a large error will occur if the actual measured value for hot water supply is used. In principle, when hot water is to be supplied immediately after the start of hot water supply and the replenishment of molten metal, the previous actual measurement data is reset and the hot water supply operation is performed assuming that the amount held at standard full capacity is maintained.

The basic control flow and method of the embodiment in FIG. 2 are the same as those in FIG. 3. However, as a matter of course, by providing a hot water inlet,
1, 63-33168, 61-33169, 63-16
5062, etc., it is possible to receive molten metal replenishment even during hot water supply, and replenishment is performed without opening the inspection port cover 20 as in the embodiment of FIG. Since operation is restarted after replenishing molten metal without checking the internal status of the molten metal, not only hot water is supplied immediately after confirmation that the molten metal is full, but also
When hot water is being supplied while the water intake is open, immediately after the hot water intake lid is closed, or immediately after the operation is stopped and restarted due to an emergency stop, the previous actual measurement data is reset and the hot water supply operation is performed assuming that the amount held at the standard full time is the same as in the above example. Let's do it.

Incidentally, in claim 2, the pneumatic hot water supply furnace 1
holds the molten metal 2 in excess of the standard full amount, and when the subtraction result in the subtractor A is negative, the reason for slowing down the pressurization to the pneumatic hot water furnace 1 is because there is a large amount that can be replenished beyond the standard full amount. Or,
It is the best case to slow down in relation to the cycle of the casting machine, and in claim 3, the reason why the constant value is set near the condition of the standard full quantity is due to the relative characteristics and characteristics of the cycle of the casting machine. Based on the relationship. These matters also apply to claims 4 and 5.

[0023]

[Effects of the Invention] As explained above, the present invention has realized a constant cycle hot water supply control method that enables stable, efficient, and safe production of castings using a pneumatic hot water furnace. .

[0024]

[Brief explanation of drawings]

[Figure 1] Constant cycle hot water supply control method chart

[Figure 2] Example of fixed cycle hot water supply control method chart (Part 1)

[Figure 3] Example of fixed cycle hot water supply control method chart (Part 2)

[Explanation of symbols]

1 Pneumatic hot water furnace 2 Molten metal 3 Hot water pipe 4 Hot water intake 5　　　　Outlet 6 Hot water sensor 7 Gutter 8 Die casting machine sleeve 9 Hot water receiving pipe 10　　　　　Inlet 11　　　Receiving sprue opening LS 12 Inlet mouth closed LS 13　　　　　　　　　　　　　　　 14 Pressure control device 15 Furnace pressure conduit 16 Pressure solenoid valve 17 Exhaust solenoid valve 18 Exhaust port 19 Pressure source 20 Inspection palate 21 Inspection port 22 Full sensor

Claims (5)

[Claims] 1. A hot water supply control method for supplying a required amount of molten metal from a pneumatic hot water furnace by pressurizing with gas in response to a hot water supply command for molten metal from a casting machine, wherein the amount of molten metal held in the pneumatic hot water furnace is The standard full time is used as the basis for setting the timing to start pressurizing the pneumatic hot water furnace with gas, and the first hot water supply after the start of operation for casting that is not after a temporary operation stop and the metal in the pneumatic hot water furnace When the amount of molten metal held decreases, we measure the actual cycle time for each time to supply water to the casting machine, excluding the first supply immediately after receiving replenishment from external equipment, and calculate the difference from the previous actual cycle time. As a feedback, the amount of molten metal held in the pneumatic water heating furnace decreases as hot water is supplied, and in order to supply the same amount of hot water each time in proportion to the decrease, it is necessary to supply pressurizing gas to the pneumatic water heating furnace. In response to the need to increase the amount of water, that is, the pressurization time increases, the cycle time for casting in the casting machine can be stabilized by accelerating the start of pressurizing the pneumatic hot water furnace with gas during the next hot water supply. 1. A constant cycle hot water supply control method characterized by making corrections so as to increase the temperature. [Claim 2] In the fixed cycle hot water supply control method of claim 1, the amount of molten metal held in the pneumatic hot water supply furnace decreases, and when the hot water is supplied from external equipment, the amount of hot metal received exceeds the standard full amount. A constant cycle hot water supply control method characterized in that the start of pressurizing the pneumatic hot water supply furnace with gas is delayed rather than earlier. [Claim 3] In the fixed cycle hot water supply control method according to claim 1, the amount of molten metal held in the pneumatic hot water supply furnace decreases, and when the hot water is supplied from external equipment, the amount of hot metal received exceeds the standard full amount. A constant cycle hot water supply control method, characterized in that, in the case of the above-described case, the start of pressurizing the pneumatic hot water supply furnace with gas is set to a fixed value inputted in advance without hastening the start of pressurization with gas. 4. In the fixed cycle hot water supply control method of claim 2, when an abnormal signal is received, the hot water supply operation is stopped in an emergency, and the first hot water supply immediately after hot water supply is restarted, the amount of molten metal held in the pneumatic hot water supply furnace decreases and Hot water supply while the molten metal receiving port opening LS signals that the lid of the receiving port that receives molten metal replenishment is open for any reason, including when receiving replenishment from equipment, and the receiving For each hot water supply for the first time immediately after the closure of the sprue cover is signaled by the receiving port close LS, the above-mentioned correction to accelerate the start of pressurization with gas to the pneumatic hot water furnace is not performed. Characteristic constant cycle hot water supply control method. 5. In the constant cycle hot water supply control method according to claim 3, the amount of molten metal held in the pneumatic hot water supply furnace decreases during the first hot water supply immediately after receiving an abnormal signal, emergency stopping the hot water supply operation, and restarting hot water supply again. hot water supply while the molten metal receiving port opening LS signals that the lid of the molten metal receiving port is open for any reason, including the case of receiving replenishment from external equipment; In the first hot water supply immediately after the signal is transmitted by the hot water inlet close LS that the lid of the hot water inlet is closed, the above-mentioned correction to accelerate the start of pressurization with gas to the pneumatic hot water supply furnace is not performed. A constant cycle hot water supply control method characterized by the following.