JPS633705B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a casting method for casting a small-diameter rod-shaped body by injecting molten metal (hereinafter also simply referred to as molten metal) into a small-diameter cavity provided in a mold, and the method. It relates to an apparatus suitable for carrying out the method.

Recently, for example, with regard to welding rods, welding automation has progressed, and the demand for longer welding rods has increased.

In order to manufacture this type of thin and long rod, it is possible to manufacture it from an ingot by rolling it, but the diameter of the ingot is 500 to 600 mm, and in order to reduce the diameter to, for example, 2 to 3 mm, ,
Rolling must be performed several dozen times, which is impossible from a cost standpoint. Moreover, it is naturally impossible to roll a material that is hard and has poor ductility.

Therefore, this type of thin rod has conventionally been manufactured by a casting method. However, in this case, since it is a thin rod, the heat capacity of the entire molten metal is water, which makes it easy to cool and solidify, and the low resistance to the molten metal entering the cavity (which is thought to be based on the viscosity and surface tension of the molten metal) is ignored. However, it was difficult to obtain long cast rods.
Therefore, the applicant of this application not only has the weight of the molten metal itself, but also
Previously, we proposed a method for making long rods by injecting molten metal into the cavity using external pressure. In this method, for example, as shown in FIG. Casting is performed by suctioning with a vacuum pump 4 connected via a vacuum pump 4.

In this case, as mentioned above, the molten metal must be injected within a short time before it cools and solidifies, so the molten metal must be supplied quickly. It was also found that the timing of vacuum suction is appropriate when the molten metal has slightly entered the cavity 2. That is, if the timing of vacuum suction was too early, the molten metal would not be supplied in time, while if the vacuum was applied too late, the molten metal would cool and solidify, often resulting in the inability to obtain a bar of the desired length.

This invention further improves the technology related to the above-mentioned proposal by taking these points into consideration, and it is possible to quickly supply molten metal and maintain a constant pressure application timing. It is an object of the present invention to provide a method for casting a rod-shaped body having a diameter of about 100 mm, and a casting apparatus suitable for carrying out the casting method.

An embodiment of the casting apparatus of the present invention will be described below with reference to FIGS. 2 to 4. Note that the casting method will become clear by explaining the casting apparatus, so the explanation thereof will be omitted.

In the figure, reference numeral 11 denotes a mold, and inside this mold 11 there are openings 12a, 1 along the axis and on both end faces in the axial direction.
A cavity 12 having 2b is provided.
One opening 12a of the cavity 12 serves as a sprue (hereinafter, the opening 12a will be referred to as a sprue).
Further, the mold 11 is rotatably supported on a support stand 14 by horizontal shafts 13, 13 perpendicular to the axis thereof, and the sprue 12a of the cavity 12 is directed downward except when pouring the molten metal M into the cavity 12. ing. In this state, the crucible holding frame 15 is attached to the lower end surface of the mold 11. Note that the holding frame 15 of this crucible has a horizontal axis 1
It may be attached to 3 and 13. Further, a crucible holder (pressing means) 17 is provided at the bottom of the crucible holding frame 15 for pressing the opening 16a of the crucible 16 against the lower end surface of the mold 11 by moving up and down by a screw mechanism. With this, the mold 11 and the crucible 16
The crucible 16 is configured to rotate (reverse) integrally with the crucible 16, and when the crucible 16 is reversed, the molten metal M in the crucible 16 is injected into the cavity 12 from the sprue 12a. Note that the horizontal shafts 13, 13 may be rotated by a drive source such as a motor, or may be rotated manually. Further, a limit switch 18 is attached to an appropriate location on the support base 14, and a corresponding limit switch striker 19 is attached to the outer periphery of the mold 11.
9 constitutes a timing device. As shown in FIG. 3, the limit switch 18 is fixed by a bolt 21 inserted into a groove 20 with a T-shaped cross section extending in the front and back directions in the drawing of the support base 14.
This allows the position to be adjusted. This position adjustment mechanism allows the limit switch 18 to operate at the optimum timing, just before or after the mold 11 and crucible 16 are reversed and the axis of the cavity 12 aligns vertically again. In other words, the molten metal M in the crucible 16 slightly flows into the cavity 12, and the crucible 1
It is designed to operate when a sufficient amount of molten metal M is supplied from inside 6. In this case, the position of the limit switch 18 is adjustable, but
The limit switch taps 19 may be adjustable in position, or these limit switches 18
The positions of both the limit switch striker 19 and the limit switch striker 19 may be adjustable.

On the other hand, a vessel 22 is fixed to the upper end surface of the mold 11 with a bolt 23. A filter 24 is attached to the lower end of this vessel 22, and the filter 24 controls the cavity 1.
The opening 12b of No. 2 is covered. This filter 2
4 is for preventing the molten metal M from leaking from the cavity 12 and removing the splash generated from the molten metal M, and is made by combining a metal filter, a refractory filter, etc. Further, a solenoid valve 26 and a vacuum absorbing means 27 are sequentially installed in the vessel 22 from the vessel 22 side via a flexible pipe 25. The solenoid valve 26 is opened by a limit switch 18, as shown in FIG. In addition, the vacuum suction means 27
is the vacuum tank 2 installed sequentially from the solenoid valve 26 side.
8 and a vacuum pump 29. The vacuum tank 28 is used to rapidly bring the inside of the cavity 12 into a vacuum state and maintain the vacuum state, and has a capacity larger than the total capacity of the vessel 22 and the piping 25.

When casting a small-diameter rod-shaped body using the apparatus configured as described above, first, the crucible 16 containing the molten metal M is pressed by the crucible holder 17 onto the lower end surface of the mold 11, that is, the end surface where the sprue 12a is located. Press to make a tight contact. Next, by rotating the horizontal shaft 13, the mold 11
and rotate the crucible 16. As the rotation progresses, the molten metal M in the crucible 16 flows into the cavity 12 due to its own weight. Just before or after this,
That is, the limit switch 18 is actuated by the limit switch strike 19 at the optimum time for suction when the axis of the cavity 12 becomes vertical again.
Then, the solenoid valve 26 opens, and the inside of the cavity 12 is rapidly evacuated by the vacuum tank 28.
The molten metal M flows quickly through the cavity 12 against its viscosity and surface tension and reaches the filter 24. Moreover, at this time, since the molten metal M is sufficiently supplied from inside the crucible 16, the molten metal M will not be supplied in time. Note that the mold 11 is stopped when the axes of the cavity 12 are aligned with the vertical direction. This makes it possible to utilize the weight of the molten metal M most effectively.

Note that a delay timer may be used as the timing device. In this case, for example, the delay timer is set to operate at the same time as the drive source of the horizontal shaft 13 is operated, and after a certain period of time, that is, the mold 11 is reversed. A delay timer may be set to open the solenoid valve 26 immediately before the axis of the cavity 12 coincides with the vertical direction.

Further, although the vacuum tank 28 is not necessarily necessary, by installing the vacuum tank 28, the inside of the cavity 12 can be quickly brought into a vacuum state, so that a longer rod-shaped body can be cast. Further, the vacuum pump 29 can have a small capacity.

Furthermore, if the piping 25 is made of a rigid material and set so that the rotation moment of the horizontal shaft 13 is connected, the mold 11, the crucible 16,
Further, it becomes easy to rotate the vacuum tank 28 and the like, and they can be rotated manually or by a small motor or the like.

As explained above, according to the present invention, a mold having a small diameter cavity opened at the upper end surface and the lower end surface is used, and the mold is inverted while the crucible is pressed against the lower end surface of the mold, and the mold is inverted. Since the molten metal is injected by lowering the pressure at the lower end of the cavity relative to the upper end side of the cavity, the molten metal can be sucked into the cavity at a certain time when the molten metal slightly flows into the cavity. At this time, a sufficient amount of molten metal is supplied from the crucible, so that the molten metal can be quickly and reliably injected into the cavity, and as a result, a rod-shaped body of the required small diameter can be reliably cast. In addition, since the molten metal collects at the upper end of the mold when it is inverted, the weight of the molten metal can be used more effectively, and the molten metal does not scatter when poured, making it safer. .

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the molten metal injection method according to the previous proposal, FIG. 2 is a vertical cross-sectional view schematically showing an embodiment of the casting apparatus according to the present invention, and FIG. 3 is a diagram showing the circle of FIG. 2. FIG. 4 is an enlarged diagram of the wiring diagram of the limit switch and the solenoid valve. 11... Mold, 12... Cavity, 12a...
...opening (gate), 12b...opening, 14...support stand, 16...crucible, 16a...opening, 17...
Crucible holder (pressing means), 18... limit switch, 19... limit switch hitter, 27...
...Vacuum suction means, M... (metal) molten metal.

Claims (1)

[Scope of Claims] 1. Using a mold 11 equipped with a small-diameter cavity 12 that is open at an upper end surface and a lower end surface, the lower side of the cavity 12 is lowered in pressure relative to the upper side. A casting method in which molten metal M is injected into the cavity 12 from the side, the mold 11
The molten metal M is injected into the cavity 12 by pressing a crucible 16 containing the molten metal M against the lower end surface of the mold, and then inverting the crucible 16 together with the mold 11 to inject the molten metal M into the cavity 12. Method for casting rod-shaped bodies. 2. Claim 1, characterized in that when the axis of the cavity 12 becomes substantially vertical due to the inversion of the mold 11, the pressure on the lower side of the cavity 12 is relatively lowered than on the upper side. A method for casting a small-diameter rod-shaped body as described in . 3. A mold 11 having a small-diameter cavity 12 that opens on the upper and lower end surfaces, a support base 14 that supports the mold 11 so that it can be turned upside down, a crucible 16 attached to the mold 11, and a crucible 16. The opening 16a of the crucible 16 is pressed against the lower end surface of the mold 11 to open the injection side opening 1 of the cavity 12.
2a, a vacuum suction means communicated with the suction side opening 12b of the cavity 12, and a timing device 18 that operates the vacuum suction means 27 in conjunction with the reversal operation of the mold 11. 19. A casting device for a narrow rod-shaped body, characterized in that it is equipped with: 4 The timing devices 18 and 19 are composed of a limit switch 18 provided on one of the support base 14 and the mold 11, and a limit switch striker 19 provided on the other.
Claim 3, characterized in that at least one of 9 and 9 is provided so that its position can be adjusted.
Apparatus for casting a small-diameter rod-shaped body as described in 2.