Molten metal supply device and aluminum titanate ceramic member having improved non-wettability

However, since an electromagnetic pump confers a thrust to the molten metal, which is a fluid, it is difficult to accurately control the transfer volume thereof by means of current control.

Even when a discharge cylinder is provided for supplying a molten metal to the cavity, the molten metal supply accuracy of the electromagnetic pump ultimately becomes a problem.

However, aluminum titanate ceramic only appears to possess low thermal resistance because of cracks that appear at its grain boundaries.

Thus, the fact that the mec...

A preferred structure is illustrated in FIG. 7. FIG. 7 shows a float 28 installed on the transport conduit 4 via a mounting unit 30. In this example, the float 28 includes a catch 28a that is caught on the upper edge of the mounting unit 30, and a contact member 28b that comes into contact with the molten metal inside the transport conduit 4. The catch 28a includes an indicator 29 that indicates the displacement of the float 28. The catch 28a of the float 28 is engaged with the upper edge of the mounting unit 30 to enable the float 28 to rock, and at the same time, the mounting unit 30 has a space 30a that can accommodate the maximum displacement of the float 28 without hindering its rocking movements. In this example, the float 28 itself serves as a detection member, and the displacement produced by the contact member 28b is transmitted as is to the catch 28a and the indicator 29, and thus is easily comprehended from outside. Note that it is of course possible to use a separate detection member to transmit the displacement of the float to the outside.

Because of this, as shown in FIG. 8 and FIG. 9, it is preferred that the rotary vane 22 be snapped into the transport conduit 4, primarily using tapered concave and convex members. More specifically, a tapered fitting hole 42 is provided in the transport conduit 4 in which the caliber thereof grows smaller toward the interior of the conduit, a cap 44 is employed that has a tapered convex portion 46 that is fitted to and matches the fitting hole 42, and a through hole 48 in which the shaft 24 can be mounted is provided in the convex portion 46. In this way, the rotary vane 22 can be mounted inside the transport conduit 4 by fitting the aforementioned cap 44 into the aforementioned fitting hole 42, and thus the precision of the seal on the conduit 4 can be improved and maintained by means of a mechanical fitting.

First, molten metal in the molten metal holding furnace 18 is supplied to a cavity for a metal cast by operating the electromagnetic pump 10. As the molten metal is transported, the rotary vane 22 provided inside the transport conduit 4 rotates, and the rotational frequency thereof is detected by the detector 32. If the relationship between the rotational frequency and the amount of molten metal has been established, the operating time of the electromagnetic pump 10 and the power supply are adjusted based on the rotational frequency, such that the desired time of rotation of the rotary vane 22 and/or the rotational frequency thereof are obtained in order to supply a predetermined amount of molten metal to the cavity. In this way, a constantly accurate amount of molten metal can be supplied to the cavity of the metal cast, and a cast metal object can be manufactured with a high degree of precision.

For example, as shown in FIG. 4, the rotational frequency detector can be a pulse generator 32 that is arranged such that when the rotation of the shaft 24 inside the transport conduit 4 is transmitted, the pulse generator 32 detects the rotation and generates a pulse. Note that by transmitting the pulses generated by the pulse generator 32 to a device equipped with a pulse counter mechanism, the rotational frequency can be easily detected.

Furthermore, as shown in FIG. 4, the drive force of the external motor 40 can be transmitted to the shaft 24, and the rotary vane 22 can be formed so that it is rotatively driven from the exterior thereof. In this way, sufficient rotational force can be conferred to the rotary vane.

Furthermore, in situations in which a detection means for detecti...

According to this method, a highly precise cast metal object can be easily obtained.

In addition, another aspect of the present invention provides, a measuring device for a molten metal supply device that uses an electromagnetic pump having: a rotary vane that is provided in a molten metal transport conduit and which is rotated in accordance with the movement of molten metal; and a detector that detects the rotational frequency of the rotary vane. In this measuring device, it is further preferred that a means of detecting the amount of molten metal inside the transport conduit be provided in the transport conduit. According to this device, the amount of molten metal transported can be measured with a high degree of accuracy.

In addition, the present inventors have studied the decrease in the non-wettability of aluminum titanate ceramic wi...