JPS5835790B2 - Casting method - Google Patents

Description

Detailed Description of the Invention The present invention relates to a casting method in which a ladle is tilted by an electric drive and a fixed amount of metal is poured per hour. The purpose is to accurately control the amount, reduce molten metal loss, and ensure accurate dimensions and weight of products in centrifugal casting, etc.

In a casting device of a centrifugal casting machine, a method is generally adopted in which a ladle is tilted at a constant speed to pour a fixed amount of molten metal per hour, and this tilting of the ladle is usually performed by an electric drive.

However, in this case, the ladle could only be restored at the same speed as the tilting speed, and because the restoration speed was slow, there was a problem in running out of hot water at the end of pouring (no molten metal coming out from the mouth of the ladle).

As a result, a large amount of molten metal is lost, the weight and dimensions of the product determined by the amount of casting become inaccurate, and the molten metal scatters, resulting in deterioration of safety and the working environment.

It is also possible to pour the specified volume by operating the tilting drive device in anticipation of the time for the melt to run out in advance, but there are conditions such as the longer pouring time and the change in fluidity depending on the temperature of the molten metal. This makes it extremely difficult.

Therefore, the present invention attempts to solve the above-mentioned problems by increasing the recovery speed of the ladle to improve the draining of hot water.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a ladle, which is placed and fixed on a rocking table 2 that can swing up and down.

One end of the rocking table 2 is fixed to a rotating shaft 4 rotatably supported by a bearing base 3, and an end of a tilting operation lever 5 is fixed to one end of the rotating shaft 4. By pushing and pulling this tilting operation lever 5 up and down, the ladle 1 can be tilted and restored.

The tilt operation lever 5 is operated by a rotation drive device 8 consisting of a motor 6, a speed reducer 7, etc., and a swing conversion device 11. It is pushed and pulled up and down through a drive lever 12 that is oscillated in conjunction with the fan-shaped gear 10, and a lever 13 that connects the tips of this drive lever 12 and the tip of the tilt operation lever 5.

In such a drive path, a quick return mechanism is attached to the lever 13, and this lever 13 will be described in detail below.

The tilt operating lever 5 is always urged downward by the weight of the ladle 1, and as will be described later, the lever 13 must be able to extend and retract with the operating lever 5 stopped at the lower limit position. Therefore, the tip of the operating lever 5 is further extended to provide an abutting member 14, and a stopper 15 is provided, with which the abutting member 14 abuts against the shaft support 3.
is fixedly installed to regulate the lowering limit of the operating lever 5 separately from the drive path.

As shown in FIGS. 1 and 2, the lever 13 consists of an operating side metal fitting 16 and a driving side metal fitting 17. One end of a cylinder 18 is fixed to the operating side metal fitting 16, and the driving side is attached to the other end of the cylinder 18. Metal fittings 17
It is constructed so that it can be slidably inserted and expanded and contracted in the longitudinal direction.

Then, the cylinder device 19 is housed in the cylindrical body 18, its lower end is fixed to the driving side metal fitting 17, the tip of the piston rond is fixed to the operating side metal fitting 16, and the cylinder device 19 is fixed to the driving side metal fitting 17.
This is so that both the full members 16 and 17 can be separated from each other.

In Fig. 2, 20 is a bushing, and 21 is a lid for stopping the bushing from being removed.Also, by removably fixing the operating side metal fitting 16 and the cylinder body 18 with bolts or pins, etc., they can be easily disassembled for repair. I'll do what I can.

A working fluid source 25 is connected to the lower port 23 (expansion port) of the cylinder device 19, and the upper port 24 (contraction port) is open to the atmosphere.

The working fluid source 25 has a volume of 5 to 6 of the oil tank 26.
It consists of hydraulic oil 27 stored in a
As shown in the figure, this oil tank 26 is sealed, and a predetermined air pressure is applied to the upper space of the oil tank 26 to press the surface of the hydraulic oil 27 at all times.

That is, an air pipe 29 from an air source 28 is connected to the upper end of the oil tank 26, and this air pipe 29 is connected to a filter.
An air control unit 30 consisting of a pressure regulating valve, oiler, etc. and a stop valve 31 are interposed.

On the other hand, the lower port 23 of the cylinder device 19 and the inside of the hydraulic oil 27 are connected by a suction pipe 32, and the suction pipe 32 includes a flexible pipe 33 for allowing the lever 13, that is, the cylinder device 19 to move up and down, and a flow rate A flow rate regulating circuit 36 that is controlled by a regulating valve 34 and a check valve 35, and a solenoid valve 37 for switching the suction pipe 32 between a conductive state and a non-conductive state are interposed.

This solenoid valve 37 is configured to be switched to a conductive state when the operating side metal fitting 16, that is, the operating lever 5 is lowered, and to be switched to a non-conductive state before the driving side metal fitting 17, that is, the driving lever 12 is driven upward. ing.

The suction pipe 32 connected to the oil tank 26 is the third
As shown in the figure, a suction port is opened at the bottom of the oil tank 26 to prevent air from being sucked in.

Next, to explain the operation, when the ladle 1 is tipped over from the solid line state in Fig. 1 to the imaginary line state in order to perform casting,
If the rotation drive device 8 is driven in normal rotation, the swing conversion device 11,
Tilt operation lever 5 via drive lever 12 and lever 13
is swung upwards, and accordingly, the ladle 1 is tilted at a constant speed,
The molten metal in the ladle 1 is poured in a fixed amount per hour.

At this time, since the solenoid valve 37 is switched to a non-conducting state while the cylinder device 19 is extended, the push-up force of the drive lever 12 is transmitted to the tilt operation lever 5 while the lever 13 is extended.

Therefore, at this time, a pressure corresponding to the pushing down force due to the weight of the ladle 1 is applied within the hydraulic cylinder device 19.

When a predetermined pouring amount is reached, the rotary drive device 8 is driven in reverse rotation to drive the drive lever 12 downward, but at this time, the solenoid valve 37 is switched to the conductive state, so that the hydraulic oil in the cylinder device 19 is 27 is a flow rate regulating valve 34 and a solenoid valve 3 due to the pressing force due to the weight of the ladle 1.
7 and return to the oil tank.

At this time, the inside of the oil tank 26 is pressurized by the air piping, but the pressure in the cylinder device 19 due to the pressing force is 20 kg/ca to 120 kg/crA, whereas it is extremely low at about 2 kg/crrt. , hydraulic oil 27
The return will be made promptly.

Therefore, before the drive lever 12 lowers the operating lever 5, the lever 13 is quickly shortened and returned quickly.

This quick return distance is determined by the stroke of the cylinder device 19, and the stroke of the cylinder device 19 may be determined in accordance with the restoring tilt angle necessary for draining hot water.

Further, in order to eliminate the shock at the end of the quick return, a cylinder device with a cushion device may be used, thereby preventing vibration of the casting device and making it possible to perform stable casting.

The tilt operation lever 5 is stopped at its lower limit by the stopper 15, but the drive lever 12 further swings downward as the rotary drive device 8 is driven in reverse, so that the drive side hardware 17 and the cylinder device 19 are The cylinder device 19 is extended by being pulled down, and at the same time, the cylinder device 19
Hydraulic oil 27 is sucked inside from the lower port 13.

At this time, since air pressure is applied to the upper space within the oil tank 26, the hydraulic oil 27 is reliably sucked into the cylinder device 19, and there is no risk of air being sucked in.

Therefore, this air pressure is transferred from the oil tank 26 to the cylinder device 19.
It is sufficient to apply a head pressure of up to <2k as described above.
g/crA is sufficient, and if the flow path of the hydraulic oil 27 is completely sealed, it is not necessarily necessary to pressurize it.

In this way, when the drive-side metal fitting 17 descends to the stroke end of the cylinder device 19 and the lever 13 is in the extended state, the rotary drive device 8 is stopped, and at the same time, the solenoid valve 37 is switched to a non-conducting state, and the lever 13 is maintained in the extended state. be done.

According to the casting method of the present invention, although the pouring method is performed using a fixed amount pouring method using a constant speed tilting of the ladle, it is possible to quickly drain the hot water when a predetermined pouring amount is reached. Pouring amount can be controlled accurately.

Therefore, the loss of molten metal is extremely reduced, the dimensions and weight of products in centrifugal casting etc. can be made more accurate, and safety and work environment deterioration due to scattering of excess molten metal are eliminated.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a partially cutaway perspective view showing the overall structure of a ladle tilting device, FIG. 2 is a longitudinal sectional view of a lever, and FIG. 3 is a piping system diagram. 1... Ladle, 2... Rocking table, 4...
...Rotation axis, 5...Tilt operation lever 8...
... Rotation drive device, 11 ... Swing conversion device, 12 ... Drive lever 13 ... Lever, 15 ... Stopper, 16 ... ...Operation side metal fitting, 17... Drive side metal fitting, 18...
...Cylinder body, 19...Cylinder device, 20...
... Bush, 23 ... Extension port (lower port), 25 ... Working fluid source, 26 ...
...Oil tank, 27...Hydraulic oil, 29...
...Air piping, 32...Suction piping, 36...
...Flow rate adjustment circuit, 37...Solenoid valve.

Claims (1)

[Claims] 1. In a casting method in which a ladle is tilted at a constant speed by an electric drive to pour a fixed amount of metal per hour, when a predetermined pouring amount is reached, an extendable link interposed on the drive path is contracted, A casting method characterized by tilting the ladle at the angle necessary for draining the hot water.