JPS59127965A - Controlling system of cooling water for metallic mold - Google Patents

Abstract

PURPOSE:To control the temp. of a metallic mold in an adequate range with good accuracy by controlling the flow rate of cooling water in accordance with the optimum pattern preset in a flow rate control card at the measured temp. of the metallic mold. CONSTITUTION:The temp. of a metallic mold under casting cycle is measured by the temp. sensor in the part corresponding to any among temp. sensors 2, 3, 4. The signal of the measured temp. of the metallic mold is inputted to a control unit 10. The ratio of the temp. of the metallic mold with respect to the preset temp. is calculated and is converted to a signal for % display in the unit 10. On the other hand, flow rate control cards 22, 23, 24 are connected to the unit 10, and the relations between the temp. of the molten metal and the flow rate of the cooling water are preset in the cards 22-24. The flow rate of the cooling water with respect to the signal is calculated in the unit 10 and the corresponding flow rate control valves among flow rate control valves 26, 28, 30 are controlled in accordance with the output thereof.

Description

[Detailed Description of the Invention] The present invention relates to a mold temperature control technology in a casting method that uses a mold for aluminum, zinc, die casting, etc. and requires cooling water to cool the mold. In particular, the present invention relates to a mold cooling water control system that controls the temperature of a mold by controlling the flow rate of cooling water.

The temperature of the mold for die casting etc. is determined by pouring the metal during one casting cycle.
The temperature of the mold changes greatly due to product removal, etc., but in the casting process where this casting cycle is performed continuously, it is desirable to control the temperature of the mold within a certain optimum range in order to obtain a good quality cast product. . In particular, if the temperature of the mold drops below a certain level, there is a risk of many defective products.
As long as the mold is at a temperature below a certain level) Song<)
It is desirable to control the temperature of the mold so that it reaches an internal pressure level and at the same time lowers the temperature of the mold, which is at an appropriate level, as much as possible.

Traditionally, mold temperature control methods include water vapor flowing into the mold,
There is a method that uses a heating medium such as hot air or oil, and a method that does not use a heating medium and controls the temperature by cooling the molten metal with cooling water.

In a mold temperature control system using a heating medium, although the heating medium has the advantage of speeding up the mold temperature control and delaying the temperature drop, the heating medium is heated to raise the mold temperature to an upper limit, and the upper back 1η Because they are cooled with cooling water, they have problems such as poor thermal efficiency, large energy loss, and high running costs. In addition, the initial cost increases as a heating system is required. Furthermore, when oil is used as the heating medium, a flow path separate from that for cooling water is required in the mold, which poses a problem in that mold installation is severely restricted. Furthermore, since a high-temperature heating medium of 100°C to 300'C is used, there is also the problem that high-temperature work such as mold replacement work is involved.

On the other hand, in systems that control the temperature of cooling water without using a heating medium, problems such as energy loss, running costs, initial costs, and high-temperature work when using a heating medium are improved; Compared to when using a medium, the mold temperature rises faster at the startup of the casting process and after the temperature drops! Moreover, since the mold is cooled with cooling water, there is a problem in that the mold temperature decreases quickly, and particularly when the mold humidity i drops below a certain level, many defective castings occur. The present invention aims to improve the problems caused by cooling water control while taking advantage of not using a heating medium.

Conventionally, there are various methods for controlling mold temperature using cooling water. First, manual adjustment of the amount of cooling water relies heavily on the intuition of the operator, resulting in poor control stability and reproducibility.

3- In addition, with the method of detecting the temperature of the mold and controlling the solenoid valve installed in the cooling water passage on and off using the signal from the temperature control valve, the control is rough in the middle, making it difficult to control the temperature properly. If the number of control systems is increased in order to improve the control state, this will result in a rise in the initial cost.

In addition, in the method of controlling the amount of cooling water by temperature, the amount of cooling water is controlled according to the temperature change due to pouring into the mold and taking out the product during one casting cycle, and the temperature of the mold changes. It is not possible to perform control based on the judgment that there is a problem. Therefore, even if you want to quickly raise the mold temperature, a large amount of cooling water will flow during high temperatures during one cycle, which will cause the mold temperature to rise.
If there is a delay, or if you do not want to lower the mold temperature,
Since cooling water is frequently flowed during high temperatures during the cycle, the temperature of the mold decreases that much faster.Furthermore, with the method of simply controlling the amount of cooling water based on the mold temperature, cooling water can be added in the event of trouble with the casting machine. This causes the mold to continue to flow, causing the mold temperature to drop faster than desired, resulting in a high number of defective products.

The purpose of the present invention is to speed up the upper limit of mold humidity, delay the decrease in mold humidity, and precisely control mold temperature within an appropriate range in a method of controlling mold temperature using cooling water without using a heating medium. The purpose is to reduce the occurrence of defective products due to low mold temperature, and to save energy and resources by reducing the occurrence of defective products.

The mold cooling water control system of the present invention that meets this purpose is
A temperature sensor that measures the temperature of the mold, a flow control valve that controls the flow rate of cooling water, a flow control card that presets the relationship between the mold temperature and the flow rate of cooling water, the temperature sensor and the flow rate. The signal from the temperature sensor is input only at a predetermined measurement point during one casting cycle, and the flow rate control card is controlled according to this input to control the flow of cooling water according to the set conditions. It consists of a control unit that calculates and performs the calculated flow rate and controls the flow rate.

In a control system configured in this way, the temperature of the mold is measured only at predetermined measurement points during one casting cycle, so it is not affected by temperature changes in the mold during one casting cycle. The temperature level of the mold is detected and the cold fin is
Moisture-proofing or visual protection control of the mold temperature by rapid water flow control is performed according to the conditions of the flow rate control card in which the relationship between the mold temperature and the cooling water flow rate to be controlled fI14 is preset. The flow rate control card is set with the appropriate value of the cooling water flow rate to be controlled corresponding to the mold temperature, so if the measured mold temperature level is low, the mold will be heated as quickly as possible. : The flow rate of sea urchin cooling water is throttled, and if it is high, the opening of the flow control valve is increased and a large amount of cooling water is flowed, and if it is within the appropriate range, the current status is maintained and the temperature level does not drop. The flow rate is controlled with high precision. Therefore, at the start of the casting process, the temperature of the mold is accelerated, and after the temperature has been raised, it is controlled to stay within an appropriate range. When the time between casting cycles becomes longer than the normal interval and the temperature of the mold is about to drop, the flow rate of the cooling water is throttled as much as possible to delay the drop as much as possible. By promoting this increase in mold temperature and delaying its decrease, the number of defective products that occur due to low mold temperature is greatly reduced.

In addition, when the occurrence of defective products is reduced, the energy for remelting the defective products and the operating energy of the casting machine are reduced accordingly, promoting energy conservation and reducing metal loss, auxiliary materials, etc. during remelting of defective products. Since the amount of water is reduced, resources can be saved.

Furthermore, by adopting a flow rate control card, optimal control according to the mold when replacing the mold, optimal control according to each part of the mold, control of multiple cooling water systems with one control unit, etc. This can be easily carried out, and stepless flow control corresponding to the mold temperature can also be carried out.

Below, 7-7 of the mold cooling water control system of the present invention is explained. A preferred embodiment will be described with reference to the drawings.

FIG. 1 shows an umbrella-shaped cold entry water control system according to a first embodiment of the present invention, and 1 in the figure is a mold. The mold 1 is equipped with a temperature sensor 2.3.4 consisting of a thermocouple or a resistance thermometer to measure the temperature of the mold 1, and the temperature sensor 2.3.4 is compensated. The control unit 1-10/') is connected via conductors or the like to an input terminal 13.14.15 paired with a temperature sensor 2.3.4.

The cooling water intake port 5.6.7 of the mold 1, which corresponds in pair to the temperature sensor 2.3.4, is connected to the flow control valve 26.28.30.
It is connected to the cooling water supply source 25 by piping or the like via flowmeters 32, 33, and 34.

The two control units 27, 31 of the flow control block ↑ are connected to one output terminal, 2o, 2 of the control unit 10, and are controlled according to the control signal of the control unit 1o.

The flow meters 32, 33, 34 are connected to the input terminals 16, 17, 18 of the control unit 10 so that the measured flow signal is input to the control unit 10.

The control unit 10 is also connected to one or more replaceable flow control cards 22, 23, 24. In the flow rate control cards 22, 23, and 24, the relationship between the temperature of the mold and the flow rate of cooling water is set in advance as a pattern.

The temperature measurement point signal 8 and the cycle time over signal 9 are each connected to an input terminal LL12 of the control unit 10, and the respective signals are input thereto. The temperature measurement point signal 8 is a signal that controls the measurement point at which the temperature sensor 2.3.4 should measure the humidity of the mold 1, and the cycle time over signal 9 is a signal that controls the time point at which the temperature sensor 2.3.4 should measure the humidity of the mold 1. This is a signal that is emitted when the length is longer than . In addition, temperature sensor, flow control card, flow control valve,
All flowmeters have a one-to-one correspondence.

The control unit 10 receives the temperature measurement point signal 8, reads the input from the temperature sensor 2, 3, and 4 (41 of the mold 1), and calculates the amount of cooling water based on the control pattern of the outflow control card 22, 23, and 24. This result and the flowmeter 32
．． Compare the input (outflow) from 33.34 and send it to the outflow control control section 27.29.31, and then adjust the flow rate control valve 26.28.30 with the calculation result and flowmeter 32.33.3/
Control is performed so that the input of I matches the input of I. The control signals for the outflow control valves 26.2B and 30 are held until the next signal 8 is input to the temperature measurement point 1.

In addition, when the cycle time over signal 9 is input to the control-]Ninira 1 to 0, the signal is reset.
, assuming mold humidity to be O, flow control card 22.23
．． The amount of cooling water is controlled (reduced) based on 24 control patterns.

In the control system of the present invention configured in this way, the temperature of the mold and the flow rate of cooling water are controlled as follows.

As shown in FIG. 2, the time point at which the mold temperature T is measured is determined by the temperature measurement point signal 8 in each casting cycle C1, C2,
Among C3, . . ., the case where the measurement time points P1, P2, P3, . In addition, A2 is the curing T culm, A3 is the product removal and mold release agent application process, A,
is the mold clamping process.

For example, if the temperature measurement point signal 8 is issued during the tRjFi cycle C4, the mold temperature T4 at 14 points during the casting cycle C4 will be the corresponding part of any of the temperature sensor numbers 2.3.4. Measured by temperature sensor.

A signal of the measured mold temperature T4 is input to the control unit 10. In the control unit 10, the ratio of T4 to a preset temperature is calculated and converted into a signal T4' expressed as a percentage of the preset temperature. On the other hand, flow control cards 22, 23, 24 are connected to the control unit 10, and the flow control cards 22, 23, 24 have a pattern of the relationship between the mold temperature and the amount of cooling water as shown in FIG. It is preset as . One pattern is set for each 11-1 card.

Iyo T+' No. 63 on the flow control card corresponding to Jin-kun
If the pattern is set, control unit 1
0, cold y, oral water flow FI Q 4 for T4' signal
is calculated. Based on the output of this C4, the flow control valve 2
The corresponding outflow control valve of 6.28.30 is controlled. That is, a signal is sent to the control unit 27.29.31 of the outflow control valve so that the flow rate of the cooling water detected by the corresponding flow rate reduction of the flow rate 32.33.371 matches the calculated cooling water flow IQ4. The outflow control valve is outputted and the outflow control valve is controlled to control the actual amount of cooling water to 04.

In such control of cooling water flow suspension, the temperature measurement of the mold 1 is performed only at predetermined measurement points during one casting cycle, so the temperature measurement of the mold 1 by Note IA+ etc. during one casting cycle The temperature level of the mold 1, that is, the temperature range in which the current casting cycle is being performed is detected by the representative points PI, P2, P312-... without detecting the temperature change of 1. Then, the representative points P+, P2,
Based on the mold temperature measured at P3,...
11 Temperature control specifications for the mold 1 from a fixed point to the next measurement point are determined. This temperature control specification is based on the outflow control card 2.
2.23.24, and the amount of cooling water is determined based on the pattern. This pattern has the optimal flow rate of cold water set for the mold temperature, or by selecting a card with such an appropriate R pattern, the outflow of cooling water can be prevented. , the mold temperature is controlled to the optimum outflow so that it is within the appropriate range.

For example, in the case of casting cycle C1 in FIG.
If the temperature of mold 1 is still low during one casting cycle when the culm is rising, the mold temperature may temporarily become high during casting cycle C1, but the temperature level of the entire casting cycle C1 may be low. Based on the measured temperature, the amount of cooling water will be reduced, and the amount of cooling water will be reduced due to the heat received from the molten metal being poured. The temperature of No. 1 is about to rise. In addition, the amount of cooling water does not change even if there is a point where the temperature of the mold is temporarily high during one casting cycle, and the amount of cooling water is reduced as much as possible as one water pump is used to withstand excessive cooling. The temperature rise of type 1 is significantly enhanced over conventional systems. Also, like C4-cycle, mold 1
Conversely, when the humidity level becomes high, the cold water supply is increased. By controlling the flow rate of cold river water in this manner, the temperature of mold 1 quickly decreases to <J29? When it's done (ko, -
(There is some vertical fluctuation in the vessel, but it is within the appropriate temperature range B, and the temperature is at the appropriate temperature.)
C6 and C7 are obtained. A, appropriate range B as in C6
Even within this range, when the level reaches a slightly lower level, the flow rate of the cooling water is throttled to prevent a further drop, and the flow rate of the cooling water is controlled to return to the center level of the appropriate range B. i.e. flow control card 22.23.2
4, the amount of cooling water is set steplessly for the mold temperature, so the amount of cooling water is finely and accurately controlled, and the mold temperature is within the appropriate range I! It is controlled to a more central level among ff1B.

In addition, if the cycle time is extended due to some kind of trouble, such as in casting cycle C8, the mold temperature is determined to be 0 based on the cycle time over signal 9, so the cooling water flow rate is set to the minimum flow rate in the pattern of the flow rate control card. Narrowed down to. For example, in the case of No. 3 pattern, the flow rate is O. By restricting the flow rate, the rate of decrease in mold temperature is slowed down, and the decrease in mold temperature T8 is significantly greater than the mold temperature TB' when the same amount of cooling water continues to flow.

In this embodiment, the mold temperature is converted into a percentage, but the mold temperature itself may be used for control. However, in this case, the humidity that requires the maximum flow rate changes depending on the type of mold, heat capacity, temperature measurement position, etc., so the setting range of mold temperature input changes, and the control accuracy also changes.

Next, FIG. 4 shows a 15-control system according to a second embodiment of the present invention. This embodiment is an lj type in which the flow rate feedback control in the control system shown in FIG. In this case, in order to eliminate variations in flow rate due to fluctuations in the cold In water pressure on the next side, a metering valve or pressure reducing valve 38.39.4
0 is required. In addition, in this embodiment, the flow rate control card 2
2.23.241 This is the mold'/fA and the flow control valve 3.
The relationship with the opening degree of 5.36.37 is set. Its basic structure and operation are similar to those of the first embodiment.

As explained above, when using the mold cooling water control system of the present invention, the following various effects can be controlled.

First, the temperature of the mold is measured only at predetermined measurement times during one casting cycle, and the flow rate of cooling water is controlled based on the optimal pattern preset on the flow rate control card based on the measured wet condition. Since I did this, I set the mold to the appropriate range -17-,,,,.

16- The temperature can be increased and the mold temperature can be precisely controlled within an appropriate range. Further, even when the mold temperature decreases due to some kind of trouble, the rate of decrease can be made as slow as possible. By promoting the upper temperature of the mold and delaying its decrease, it is possible to prevent the mold temperature from falling below the appropriate range as much as possible, and it is possible to significantly reduce the number of defective products that occur due to the low wetted surface of the mold. By reducing the number of defective products, energy for remelting defective products, metal loss during remelting, etc. can be reduced, and energy and resource savings can also be achieved.

In addition, by setting the relationship between mold temperature and cooling water volume using a flow control card, even if the mold is replaced, it can be handled by replacing the flow control card, and the mold can be cooled by dividing it into several parts. When controlling the amount of water, it is possible to set the optimum conditions for each part by assigning one flow control card to each part, and furthermore, when controlling the amount of cooling water in multiple parts at the same time. Also,
By simply increasing the number of flow rate control cards, a single control unit can be used.

Furthermore, the output of the cooling water ink relative to the mold temperature can be set to an arbitrary approximate curve and a continuous curve using the flow control card, making it possible to control the outflow of the cooling water steplessly.
Furthermore, even if the temperature measurement position of the mold is roughly set, the approximation curve is variable, so it can be adjusted accordingly.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a mold cooling water control system according to the first embodiment of the present invention, Fig. 2 is a characteristic diagram of mold temperature at each casting cycle, and Fig. 3 is a flow control system. FIG. 4 is a diagram showing the relationship between mold humidity and cooling water ink set on a card. FIG. 4 is a configuration diagram of a mold cooling water control system according to a second embodiment of the present invention. 1...Mold 2.3.4...Temperature sensor 8...
...Temperature measurement point signal 89...Cycle time over signal 10...Control unit 22.23.24...Flow rate control card 2
5...... Cooling water supply source 26.28.30.35.36.37...
・Flow rate control valve 32.33.34...Flowmeter C1, C2
, C3, C4, C5, C6, C7, C8...
... Casting cycle patent applicant Toyota Motor Corporation (review)

Claims (4)

[Claims] (1) A groove surface sensor [1] that measures the temperature of the mold, a flow control valve that controls the diversion of cooling water to the mold, and a flow rate control that presets the relationship between the mold temperature and the diversion of the cooling water. card and
A four-cast Noicle core is connected to the temperature sensor and the diversion control valve.The signal from the temperature sensor is input only at a predetermined measurement time, and according to the input, the condition set by the diversion control card is set. A mold cooling water control system comprising: a control unit that calculates the flow rate of cold water and outputs a control signal to the flow rate control valve based on the calculation result T. (2) The mold cooling water control system according to claim 1, wherein the temperature measurement of the mold by the eddy-electric sensor is performed only at one point in the casting cycle. (3) The mold cooling water control system according to claim 1, wherein a time-over signal of the M manufacturing cycle is input to the control unit. (4) Cooling water provided with the flow rate control valve. A mold cooling water control system according to claim 1, wherein the system is provided with a flow meter.