KR101994555B1 - Casting temperature stability Improved Oil Heating Type mold heating system - Google Patents

Abstract

An objective of the present invention is to provide an improved mold heating system which provides an oil heating method for improving casting temperature stability, and reduces a temperature difference between molten metal and a mold instead of a conventional mold heating method of inserting heaters into multiple sections of a mold to heat the mold. The mold heating system comprises: a lower main cavity having a shape of a lower portion of an article to be manufactured by a mold; and an upper main cavity which is coupled to an upper portion of the lower main cavity, and has a shape of an upper portion of the article. The upper and the lower main cavity include: a flow passage on a position without interference with a shape portion of the article to allow oil to pass; and a plurality of temperature sensors on prescribed positions of the flow passage. The flow passage includes an inlet and an outlet and is connected to an oil tank arranged outside the upper and the lower main cavity. The mold heating system further comprises a control unit to control an oil circulation device of the oil tank. When molten metal is filled in the upper and the lower main cavity, a temperature is sensed by the temperature sensors to be transmitted to the control unit. The control unit controls a heating temperature of a main body of the upper main cavity and the lower main cavity which form the mold by accelerating or decelerating an oil circulation speed in accordance with the temperature.

Description

Technical Field [0001] The present invention relates to an oil heating type mold heating system having improved casting temperature stability,

The present invention relates to a casting mold heating method for casting a water jacket, which is an automobile part, in an oil heating type which improves the stability of the casting temperature rather than the heating of the mold through the existing hot wire, The present invention relates to a mold heating method for improving the unevenness of a solidification structure due to a temperature difference between a metal melt and a metal mold by reducing the temperature difference between the metal melt and the metal by heating the metal mold.

Generally, an engine is used as a power source for a vehicle, a ship, a generator, and the like by generating mechanical power by combustion of fuel. In addition, the engine includes a cylinder block, a cylinder head, and a cylinder as its basic structure. In the case of a water jacket, the engine has a complicated shape so that the cooling liquid can be circulated by the water channel for cooling the cylinder block and the head of the engine. The cooled water in the radiator is sucked into the motor pump and passes through the water jacket to cool the cylinder and the cooling chamber. In the case of a water jacket, it is made of an aluminum material from a conventional cast iron material because of a demand for a light weight of a vehicle and the like.

In order to improve the adhesion of the cast iron mold and to improve the casting convenience, the conventional aluminum water jacket is formed by, for example, inserting a cast iron mold in a sand mold, closing the casting mold, casting the casting mold, After the product is taken out, it is finished by a process of finishing.

In the process of manufacturing such an aluminum water jacket, the cast iron mold is heated to a predetermined temperature, and aluminum casting is carried out. In a conventional mold heating apparatus, a heater wire or a coil is inserted into a mold to heat the entire mold.

The prior art has a problem in that the heater wire or coil that provides heat is heated by the entirety of the mold in the state that the mold core shape is disposed so that the heater wire or the coil becomes large and thereby causes a time delay to reach the desired heating temperature The efficiency of the heating operation is lowered and the heating area is widened to require a large amount of energy and energy efficiency is also lowered and the uniform heating of the mold is difficult due to heat loss to the upper and lower ends of the mold. In addition, there is a problem that casting defects (cracking, change in binder thickness, high possibility of transfer and sintering) occur due to occurrence of temperature variation of the casting mold.

Japanese Patent Laid-Open No. 10987594 proposes a method of heating a mold by inserting a heater in a heating oil. In this method, when there is a problem of volume increase due to the presence of an oil tank in a mold, The distribution of the oil amount and the uniformity of the heat distribution according to the heater may be broken according to the shape of the oil tank, which is difficult to implement.

An object of the present invention is to provide an oil heating method for improving stability of a casting temperature by shifting from a conventional method of heating a mold by inserting a heater into various sections of the mold as a conventional mold heating method, And to provide an improved mold heating method capable of reducing the temperature difference of the mold.

According to the above object, the present invention provides an oil heating type mold heating method having improved stability of casting temperature, wherein a metal mold into which a molten metal is injected is heated.

That is,

A lower main cavity in which a bottom shape of the article to be manufactured as a mold is processed; And

And an upper main cavity coupled to an upper portion of the lower main cavity,

The upper main cavity and the lower main cavity,

A passage through which oil can pass at a position where it does not interfere with the shape portion of the article; And

And a plurality of temperature sensors provided at predetermined positions of the flow path,

The flow path is connected to an oil tank disposed at the outside of the upper main cavity and the lower main cavity with an inlet and an outlet,

And a control unit for controlling the oil circulation device of the oil tank,

When the molten metal is charged into the upper main cavity and the lower main cavity, the temperature is sensed by the temperature sensor and transmitted to the control unit. The control unit increases or decreases the oil circulation speed according to the temperature, And controlling the heating temperature of the cavity and the main body of the lower main body.

In this case, the diameter of the flow path is more than 10 mm and not more than 20 mm.

Wherein the control unit increases the oil circulation speed of the high temperature when the temperature of the upper main cavity and the lower main cavity body is lower than the reference value and decelerates or stalls the oil circulation speed when the temperature of the upper main cavity and the lower main cavity body is higher than the reference value, .

The control unit increases the temperature circulation speed of the high temperature and uniformizes the temperature distribution when the temperatures in the upper main cavity and the lower main cavity differ from position to position.

According to the present invention, it is possible to improve the stability of the casting temperature by reducing the temperature difference between the molten metal and the mold to a uniform distribution by installing a metal mold into which the molten metal is injected and providing a flow path through which the oil flows. Thereby improving the unevenness of the solidification structure due to the temperature difference between the metal melt and the metal mold, thereby improving the quality of the water jacket product.

That is, according to the present invention, by providing a flow path through which oil flows in a metal mold for a water jacket of a complicated shape together with a sensor, it is possible to maintain the temperature distribution inside the metal mold substantially uniform by controlling the flow rate of high- A water jacket showing an excellent solidification structure as a whole can be manufactured.

1 is a schematic view of a conventional water heater jacket (left) and an oil heating type (right).
Fig. 2 is a schematic view of a conventional water heater (left) and an oil heating system (right).
3 is a table showing the result of evaluating the temperature stability of the water jacket mold.
4 is a photograph of a water jacket sample produced.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1, the configuration of the upper main cavity 100 for a water jacket according to the oil heating method of the mold according to the present invention is shown.

The upper main cavity 100 has a water jacket shape, and is filled with molten metal. The oil passage 150 in which the oil can flow at a point where the water jacket shape is not interfered is disposed as uniformly as possible. In forming the flow path 150, the diameter of the oil pipe is set to 10 to 20 mm, and the inlet 120 and the outlet 130 are disposed outside the mold body. The oil is poured into the oil passage inlet and the oil is discharged to the outlet, and the inlet / outlet is connected to an oil tank (not shown) to form a circulation structure.

In addition, a temperature sensor 170 is provided in the vicinity of the flow path, and a control unit interlocked with the sensor 170 is provided to control the flow rate of the oil according to the sensed temperature so that the mold heating temperature does not deviate from the reference temperature. That is, when the temperature of the mold body is maintained at a predetermined temperature after the molten metal is filled in the mold, a reference value is set and input to the controller. If the temperature sensed by the sensor is lower than the reference value, If the temperature is higher than the reference value, the oil is stagnated to lower the temperature. If the sensor touches the mold and bends in the flow path or is placed at a branch point, and the internal temperature of the mold is measured differently for each point, the oil circulation speed is increased to be uniform. The suitability of the temperature control of the mold body with respect to the circulation speed of the oil depends on the diameter of the flow path. In the case of this embodiment, when the diameter is more than 10 mm and less than 20 mm, the circulation of the oil, the temperature uniformity of the mold, , And preferably, the closer to 15 mm, the more efficient it was. Therefore, it is desirable to design the flow path with a diameter of 13 to 17 mm.

On the right side of FIG. 2, a structure of a lower main cavity 200 to be combined with the upper main cavity 100 of FIG. 1 is shown. The flow path 150 and the temperature sensor 170 are installed as in the upper main cavity 100 and do not have to be completely vertically symmetrical with those on the upper side and are installed within a range that does not interfere with the original water jacket shape do. Further, it is distributed so as to ensure a uniform heating temperature as much as possible. The arrangement of the sensor, the diameter of the flow path, and the oil flow rate control method by the control unit are the same as in the upper part.

The evaluation results of mold temperature stability according to the above-described oil heating method are shown in FIG.

The accuracy of the oil line accuracy of the mold heating method according to the present invention was more than 95%, the mold temperature deviation was less than ± 2.5 ° C, and the casting temperature stability was less than ± 2.5 ° C.

FIG. 4 shows a photograph of a water jacket sample made of a mold according to the present invention, and it is confirmed that the unbalance of the solidification structure is improved.

The mold of the present invention can be applied to the production of articles molded from a metal melt having a complex shape in addition to a water jacket.

It is to be understood that the invention is not limited to the disclosed embodiment, but is capable of many modifications and variations within the scope of the appended claims. It is self-evident.

100: upper main cavity
200: Lower Main Tabit
120: entrance
130: Exit
150: Euro
170: sensor

Claims (4)

A lower main cavity in which a lower shape of a water jacket to be manufactured as a mold is processed; And
And an upper main cavity coupled to an upper portion of the lower main cavity and having an upper shape of a water jacket,
The upper main cavity and the lower main cavity,
A passage through which the mold heating oil can pass, which is provided at a position not to interfere with the shape portion of the water jacket; And
And a plurality of temperature sensors installed at bent points or bifurcations of the flow path and contacting the mold,
The flow path is connected to an oil tank disposed at the outside of the upper main cavity and the lower main cavity with an inlet and an outlet,
And a control unit for controlling the oil circulation device of the oil tank,
The diameter of the flow passage is more than 10 mm and not more than 20 mm,
When the molten metal is charged into the upper main cavity and the lower main cavity, the temperature is sensed by the temperature sensor and transmitted to the control unit. The control unit increases or decreases the oil circulation speed according to the temperature, Wherein the temperature difference between the molten metal and the metal mold can be reduced by controlling the heating temperature of the cavity and the main body of the lower main body.
delete 2. The method according to claim 1, wherein the control unit increases the high-temperature oil circulation speed when the temperature of the upper main cavity and the lower main cavity body is lower than the reference value, and reduces or stalls the oil circulation speed when the temperature is higher than the reference value. Heating system. The mold heating system according to claim 1, wherein the control unit raises the high-temperature oil circulation speed and uniformizes the temperature distribution when the temperatures in the upper main cavity and the lower main cavity differ from position to position.

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