JPH0318453A - Cooling device in die for casting - Google Patents

Abstract

PURPOSE:To accelerate cooling velocity in sprue part after pouring molten metal, to enable opening of dies at early time and to prevent chilling of a small sized casting product by independently arranging cooling system means for cooling around the sprue part, stopping feed of cooling water at the time of pouring molten metal and forcedly supplying the cooling water after end of pouring the molten metal. CONSTITUTION:By opening solenoid valves 35, 36 in a second cooling system device 8 with a die clamping complete signal, air is supplied into a jacket 29 in a sprue part metallic mold 3 from an air supplying pipe 32 to use the jacket 29 as an air receiver. By opening a solenoid valve in a first cooling system device 7 with a molten metal pouring start signal, cooling water at room temp. is supplied from water supplying pips 11, 12. By closing the solenoid valve 35 and opening the solenoid valve 34 in the second cooling system device 8 at the time of completing the pouring of molten metal, the cooling water is supplied into the jacket 29 from a water supplying pipe 31. By this method, as the sprue part is effectively cooled, it can be surely prevented that adverse effect is given to timing to taking-out of the small sized casting product.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to cooling of casting molds for casting small parts such as cast iron bearing inserts as bearing parts of crankshafts used in cylinder blocks. Regarding equipment.

(Prior art) Generally, as a casting mold, a mold having a cavity at the bottom of a sprue part mold is integrally connected, and the sprue of the sprue part mold is connected through a vertical sprue and a runner. A casting mold communicating with the cavity described above is used.

When casting small parts such as cast iron bearing inserts using such casting molds, the molten metal in the cavity described above solidifies in a short solidification period after being cast, and the small parts are placed in the mold. If kept for a long time, it will become chilled due to supercooling and its properties will become brittle, so it is necessary to open the frame early.

On the other hand, the sprue requires a relatively large capacity due to the purpose of preventing air intrusion during pouring and the pouring cycle of automatic pouring equipment, and the solidification time of the molten metal in the sprue is inevitably longer. .

In this way, the solidification timing is different between the molten metal in the mold cavity and the molten metal in the sprue of the sprue mold, so even if the product in the cavity is quickly cooled and solidified, the temperature at the sprue remains low. As shown by the dotted line C in Figure 9, the cooling rate is slow due to the predetermined capacity, and the molten vortex at the sprue becomes unsolidified or semi-solidified, making it impossible to take out the small cast product from the mold early, and There was a problem that adversely affected the timing of product removal.

Conventionally, as a cooling device for casting molds, for example,
There are devices described in JP-A No. 7-97838 and JP-A-57-85642, but the former JP-A-57-978
The device described in Publication No. 38 has a structure in which only the temperature around the mold cavity is controlled by controlling the supply of cooling water using a mold temperature detector, so it is impossible to cool the sprue part. On the other hand, the latter device described in JP-A-57-85642 has a structure in which a chiller is inserted into the sprue of the mold to solidify the molten metal at the sprue. There is a drawback that the molten metal at the sprue sometimes floats up, and the sprue cannot be sufficiently cooled by inserting the chiller mentioned above. This method had a problem that adversely affected the timing of taking out small cast products.

(Object of the Invention) The present invention provides a cooling device for a casting mold that can increase the cooling rate of the sprue after pouring and reliably prevent adverse effects on the timing of taking out small cast products. With the goal.

(Structure of the Invention) The present invention provides a first cooling system means for cooling the area around the mold cavity and a second cooling system means for cooling the area around the sprue part, and independently provides the second cooling system means for cooling the area around the mold cavity. On the other hand, this is a cooling device for casting molds that is equipped with a control means that stops the supply of cooling water to the sprue mold during pouring, and forcibly supplies cooling water to the sprue mold after pouring. characterized by something.

(Effects of the Invention) According to the present invention, after pouring, the above-mentioned control means forcibly supplies cooling water to the above-mentioned second cooling system means provided independently of the first cooling system means, and Force cooling of the parts.

As a result, the cooling rate of the sprue after pouring can be increased, enabling early opening of the frame and preventing tilting of the small cast product due to overcooling.

(Example) An embodiment of the present invention will be described in detail below based on the drawings.

The drawings show a cooling device for a casting mold, and in FIGS. 1 and 2, a sprue mold 3 is integrally connected to the upper center of a mold 2 having a cavity 1. A sprue 4 formed in the mold 2 is communicated with the above-mentioned cavity 1 via a vertical sprue 5 and a runner 6 in the mold 2.

The above-mentioned mold 2 is composed of a pair of front and rear mating molds, and in FIG. 1, for convenience of illustration, the mating surface of one of the molds is shown hatched.

The mold 2 described above is provided with a first cooling system device 7 that controls cooling around the cavity 1, while the sprue mold 3 is provided with an independent second cooling system device 8 that controls cooling around the sprue 4. There is.

Here, the above-mentioned first cooling system device 7 has two branch pipes 13 in each of the water supply pipes 11 and 12 in which the solenoid valves 9 and 10 are interposed.
, 14, 15, 16, and these branch pipes 13 to 1
6 are connected to corresponding drain pipes 21.22.23.24 through cooling water passages 17.18.19.20 in the mold 2, and electromagnetic valves 25.25 are connected to each of these drain pipes 21-24.
26, 27, and 28 are interposed.

Further, the above-mentioned second cooling system device 8 includes a jacket 29 formed in the sprue mold 3, an inlet pipe 3o connected to an inlet port 29a of this jacket 29,
A water supply pipe 31 and an air supply pipe 32 are connected to this inlet pipe 3o, and an outlet pipe 33 is connected to the outlet port 29b of the jacket 29 described above.
and electromagnetic valves 34, 35, 36 respectively interposed in the above-mentioned elements 31, 32, 33.

The above-mentioned solenoid valve 34 stops the supply of cooling water to the sprue mold 3 when pouring into the second cooling system device 8, and forces the cooling water to the sprue mold 3 after pouring. It is a control means for supplying.

In addition, each of the above-mentioned solenoid valves 9.10.25 ~ 28.34 ~
36 is controlled by the CPU in accordance with the casting takt shown in FIG.

One of the sprue molds 3.3, which is composed of a pair of front and rear mating molds, is shown in FIGS. 3 to 5, and the other is shown in FIGS. 6 to 8, respectively.

Each sprue mold 3.3 described above is integrally formed with a plurality of fins 37 extending into the jacket 29 in order to improve heat exchange efficiency. The other sprue part mold 3 has a protruding part 3 that protrudes toward the inner central part of the sprue 4.
8 and is formed on the jacket 29 side of this protrusion 38,
By providing a recess 39 that communicates with the jacket 29, cooling performance is improved.

The illustrated embodiment is constructed as described above, and its operation will be explained below.

The solenoid valves 35 and 36 of the second cooling system device 8 are opened in response to a mold clamping completion signal before the start of pouring, and the jacket 29 of the sprue mold 3 is supplied from the air supply pipe 32 through the inlet pipe 30.
This jacket 29 is used as an air reservoir.

Next, the solenoid valve 9 of the first cooling system device 7 is activated by the pouring field start signal.
10. Open valves 25 to 28 and supply normal temperature cooling water from water supply pipes 11.12.

Note that the mold temperature of the mold 2 is controlled to a predetermined mold temperature before pouring.

Next, the solenoid valve 35 of the second cooling system device 8 is closed by the timer signal output when pouring is completed, and the solenoid valve 34 is closed.
The valve is opened and cooling water is supplied from the water supply pipe 3l through the inlet pipe 30 into the jacket 29 of the sprue part mold 3.

By forcefully supplying cooling water to the jacket 29 by opening the electromagnetic valve 34, the temperature at the sprue after pouring becomes 1000°C, which is lower than the freezing point of 1l50°C, as shown by the solid line b in Fig. 9. Since the water is effectively cooled down to below, the cooling rate of the sprue can be increased. Therefore, it is possible to open the frame early and prevent the small cast product from being chilled due to overcooling, and it is also possible to reliably prevent the timing of taking out the small cast product from being adversely affected.

Note that characteristic a in FIG. 9 shows the temperature change of the mold 2.

Next, the supply of cooling water by the first and second cooling system devices 7.8 is stopped in response to the mold opening signal.

Note that the cooling water in the jacket 29 described above is pushed out by the air supply from the second cooling system device 8 in the next cycle.

Moreover, each electromagnetic valve 9, 10, 25 to 28 of the above embodiment is
The valve opening timing, valve opening amount, etc. may be controlled based on a signal from a temperature sensor that detects the temperature of the mold.

In short, by providing the second cooling system device 8 that independently cools the area around the sprue, and controlling the cooling water from this device 8 to stop flowing to the jacket 29 when pouring the molten metal, and controlling the forced supply immediately after pouring the pouring water, This has the effect of increasing the cooling rate of the sprue after hot water and reliably preventing adverse effects on the timing of taking out small cast products.

In the correspondence between the configuration of the present invention and the embodiments described above, the first cooling system means of the present invention is the first cooling system device of the embodiments.
7, and similarly below, the second cooling system means corresponds to the second cooling system device 8, and the control means corresponds to the solenoid valve 34, but the present invention is limited to the configuration of the above-described embodiment. It is not something that will be done.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, Fig. 1 is a system diagram showing a cooling device for a casting mold, Fig. 2 is a plan view of the main part of Fig. 1, and Fig. 3 is an explanation of the sprue part mold. Figure 4 is a cross-sectional view taken along the line A-A in Figure 3, Figure 5 is a cross-sectional view taken along the line B-B in Figure 3, Figure 6 is an explanatory diagram of the sprue mold, 6 is a cross-sectional view taken along the line C--C in FIG. 6, FIG. 8 is a cross-sectional view taken along the line D--D in FIG. 6, and FIG. 9 is a characteristic diagram showing temperature changes in various parts with respect to the casting tact. 1... Cavity 2... Mold Mold 3... Sprue part mold 4... Sprue 7... First cooling system device 8... Second cooling system device 3 4... Solenoid valve L<

Claims (1)

[Claims] (1) A first cooling system means for controlling the cooling around the mold cavity and a second cooling system means for cooling the area around the sprue are independently provided, and when pouring into the second cooling system means, A casting mold cooling device comprising a control means for stopping the supply of cooling water to the sprue mold and forcibly supplying cooling water to the sprue mold after pouring.