JPH046745Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a mechanism for adjusting the vertical position of an arc electrode in an apparatus for precision casting dental prostheses or decorative accessories by arc melting. .

(Prior art) Conventionally, various metals melted by arc (for example,
Dental prostheses and various decorative accessories are cast by casting titanium, titanium alloys, niobium, tantalum, nickel, chromium, cobalt, etc. into molds. The precision casting equipment used for such casting has an arc electrode vertically placed directly above the crucible placed in the melting chamber, and a voltage is applied between the arc electrode and the crucible to cause an arc discharge, and the discharge energy causes the crucible to be heated. One example is one in which the casting material inside the crucible is melted and the melted casting material is cast into a mold placed directly below the crucible.

(Problems to be solved by the invention) By the way, in the above casting apparatus, it is necessary to adjust the vertical position of the arc electrode each time depending on the type of casting material, its size or shape, etc.
For this reason, conventionally the arc electrode was held to its holding member by a collector chuck or the like. However, when holding the arc electrode with a collect chuck in this way, if you try to adjust the vertical position of the arc electrode as described above, you will have to hold the arc electrode with one hand in the melting chamber and use the other hand to hold the arc electrode, etc. The positioning accuracy was undeniably troublesome, and the positioning accuracy was not sufficient. Additionally, as the casting material melts, the distance between the arc electrode and the surface of the material increases, making the arc unstable, so it is necessary to adjust the distance between the electrodes from time to time. Conventionally, the adjustment means was provided at the outside head of the melting chamber directly above the arc electrode, which made it difficult to adjust the electrode during melting due to the arrangement of the internal viewing window, and the arrangement of the adjustment means remained an issue to be solved. was.

The present invention was devised in view of the above, and is a novel arc electrode adjustment mechanism for precision casting equipment that enables the vertical position adjustment of the arc electrode by one-handed operation outside the equipment and further improves the positioning accuracy. This is what we intend to provide.

(Means for Solving the Problems) The configuration of the present invention for achieving the above object will be explained based on the attached embodiment drawings. Fig. 1 is a schematic overall longitudinal cross-sectional view showing an example of a precision casting machine employing the mechanism of the present invention, Fig. 2 is an enlarged longitudinal cross-sectional view taken along the - line in Fig. 1, and Fig. 3 is a cross-sectional view of another embodiment. 2, FIG. 4 is a diagram similar to FIG. 2 of yet another embodiment, and FIG. 5 is an exploded perspective view of FIG. 4. That is, the arc electrode adjustment mechanism of the precision casting apparatus of the present invention is a mechanism for adjusting the vertical position of the arc electrode 3 vertically disposed directly above the crucible 2 disposed in the melting chamber 1. 3 is attached to the lower end of a solid rod-shaped holding member 4 that is airtightly and vertically slidably supported via an insulating bushing 16 and an airtight member 161 to the device main body 10, and is attached to the lower end of the holding member 4 so that the vertical position can be adjusted freely by means of a fixing screw 32. It is attached and supported via the holding member to be movable up and down on the device main body 10, and the main body 10
Its vertical position can be set by means of an external adjustment operation means 5. The screw shaft 41 included in the upper part of the holding member 4 and the bevel gears 51 and 42 connected to the adjusting operation means 5 are used, or the holding member 4 and the adjusting operation means 5 are The cam mechanism 6 or link mechanism 7 interposed between the
The gist is that the rotational force of the operating means 5 is converted into vertical movement of the holding member 4.

An example of a casting apparatus employing the mechanism of the present invention will first be briefly described. In FIG. 1, the main body 10 of the apparatus is divided into upper and lower sections by a partition wall 11, with a melting chamber 1 in the upper part and a casting chamber 8 in the lower part.

An arc electrode 3 is penetrating and suspended from the upper wall of the melting chamber 1 so as to be vertically adjustable, and crucible tilting support blocks 21, 21 are provided oppositely on the partition wall 11, and are supported by the blocks 21, 21. Tilt axis 2
The crucible 2 is supported by 0 and 20 so as to be tiltable. During melting, the crucible 2 is placed in a horizontal state so that the lower end of the arc electrode 3 faces directly above the casting material m stored in the crucible 2. Then, arc electrode 3 is the negative pole, crucible 2
If an arc discharge is caused between the casting material m and the arc electrode 3 by applying a voltage with the positive electrode,
The casting material m is melted by the discharge energy. When it is confirmed that the casting material m is completely melted, the crucible 2 is tilted by an external operation, and the molten casting material m is poured into the mold 81 from the spout.

A passage 12 is provided in the partition wall 11 to communicate the melting chamber 1 and the casting chamber 8. A wide-mouthed funnel-shaped bush 13 is fitted into the passage 12, and a packing 14 is placed directly below the bush 13. A breathable mold 81 is connected thereto. The mold 81 is placed on a support 80 whose position can be adjusted vertically, and before starting casting, the mold 81 is placed on this support 80 and its upper surface is placed closely on the lower surface of the packing 14.

A vacuum pump 9 is connected to the melting chamber 1 and the casting chamber 8 through piping, and an electrode on-off valve 91 is disposed in the middle of each piping, and a leak valve is installed in the middle of the piping on the casting chamber 8 side. 92 is provided. Furthermore, piping is connected to the melting chamber 1 so that argon gas is injected from an argon gas cylinder 93 via an electrode on/off valve 94 .

The arc discharge, the operation of the vacuum pump 9, the opening and closing of the various electrode on-off valves 91, 94, the leak valve 92, the tilting operation of the crucible 2, etc. are input in advance to a control device (not shown) installed outside the apparatus main body 10. This is done systematically based on the original programming. Further, the device main body 10 is housed in a panel 100 together with the vacuum pump 9 and other control equipment (not shown), and the adjustment operation means 5 is housed in this panel 100.
The operating movement of the operating means 5 is converted into vertical movement of the holding member 4 by various mechanisms shown in the following embodiments.

The arc electrode 3 is detachably attached to the lower end of a solid rod-shaped holding member 4 with a fixing screw 32, and the holding member 4 is vertically mounted on the upper wall of the apparatus main body 10 so as to face the crucible 2 in the melting chamber 1. It is supported through the shaft so that it can move up and down. And this holding member 4
As shown in the following embodiments, the vertical position can be set by the adjusting operation means 5 using a screw mechanism, a cam mechanism, or a link mechanism.

(Function) In the arc electrode adjustment mechanism configured as described above, the vertical position of the arc electrode 3 can be arbitrarily adjusted by operating the adjustment operation means 5 outside the device main body 10. Therefore, when placing the casting material m on the crucible 2 and starting casting, it is necessary to accurately adjust the appropriate position according to the material, size, shape, etc. of the casting material m by one-handed operation outside the apparatus. I can do it. Since the adjusting operation means 5 is disposed on the front or side of the panel and can be easily operated from the front or side of the panel, the relative position of the tip of the electrode with respect to the casting material can be accurately adjusted while causing arc discharge.

(Example) Next, an example will be described.

(Example 1) In FIG. 2, the holding member 4 includes a lower cylindrical main body portion 40 and a screw shaft 4 connected in a straight line above the lower cylindrical main body portion 40.
Consisting of 1. The main body portion 40 is held through the upper wall of the device main body 10 via an insulating bushing 16 so as to be able to slide vertically, and the arc electrode 3 is fixed to the lower end of the main body portion 40 with a fixing screw 32 so as to be detachable and vertically adjustable. ing. The bush 16 is attached to the device main body 1.
Airtight member (e.g. O-ring) 161 on the top wall of 0
This bushing 1 is attached airtightly through the
6, the main body portion 40 is vertically slidably and airtightly supported through an airtight member 161 similar to the above. An insulating cylindrical body 18 made of ceramic or the like and surrounding the lower part of the main body portion 40 is attached to the lower surface of the bush 16 via a leaf spring 181. The insulating cylindrical body 18 is for preventing creeping discharge, and when damaged, it can be replaced from the plate spring 181 portion. Further, a support frame 17 is fixedly installed on the bush 16, and a female threaded cylinder 421 is attached to the boss 171 of the support frame 17.
The threaded shaft 41 is coaxially screwed into the female threaded cylinder 421. And the internally threaded cylinder body 42
A cap gear 42 is coaxially integrated with the upper part of the gear 1.

In addition, the adjustment operation means 5 includes a head gear 51 that meshes with the head gear 42 in an intersecting state, and a horizontal operation shaft 52 that is integral with the head gear 51 and is rotatably held by the support frame 17. It consists of an operating knob 53 fixed to the rear end of the operating shaft 52.

In the above configuration of the holding member 4 and the adjusting operation means 5, when the operation knob 53 is operated to rotate around its axis, the head gear 42 rotates around its axis due to the meshing of the head gears 51 and 42. The rotation of the head gear 42 causes the screw shaft 41 to move forward and backward.
By screwing back, the holding member 4 slides up and down against the bush 16 in an airtight manner, thereby adjusting the vertical position of the arc electrode 3. At this time, if necessary, the vertical position of the arc electrode 3 can be finely adjusted using the fixing screw 32.

In the case of this embodiment, the holding member is replaced by an operation disk (not shown) threaded onto the screw shaft 41 for the head gear 42, and the adjustment operation means 5 protruding from the top surface of the panel 100 is directly rotated. 4 can also be moved up and down. Also, reference numeral 4 in the figure
01 is a stopper for preventing slippage and rotation.

(Embodiment 2) FIG. 3 shows an example in which a cam mechanism 6 is interposed between the holding member 4 and the adjusting operation means 5.
The holding member 4 is composed of a cylindrical main body portion 40 which is vertically slidable and hermetically supported through the bush 16, as described above, and an operating rod 43 which is connected in a straight line above the cylindrical main body portion 40. On the other hand, a cam plate 62 having an inclined cam groove 61 is disposed so as to be slidable left and right so as to intersect with the operating rod 43, and a cam roll 63 attached to the side circumference of the operating rod 43 is attached to the cam groove 61. The cam groove 61 is slidably inserted along the longitudinal direction of the cam groove 61, and the cam mechanism 6 is constituted by the cam groove 61, the cam plate 62, and the cam roll 63. At one end of the cam plate 62, two parallel horizontal slide rods 621 are held slidably left and right on a support frame 17 fixed to the upper wall of the device main body 10 via an insulating bush 16 as described above. , 621 are fixedly installed, and a horizontal screw shaft 622 is fixedly installed at the other end.

In addition, the adjustment operation means 5 is connected to the boss 1 of the support frame 17.
72, a cylindrical horizontal operating shaft 54 is held in such a way that it cannot be removed from the left or right and is rotatable, and the operating shaft 5
4 and an operation knob 53 fixed to the rear end thereof.
The inner cylindrical surface of the operating shaft 54 has a female thread 541.
is engraved and screwed onto the screw shaft 622 of the cam plate 62.

In the above configuration, when the operation knob 53 is rotated, the screw shaft 622 is screwed left and right with respect to the operation shaft 54 due to the rotational movement. The cam plate 62 slides left and right as the screw shaft 622 screws forward and backward in the left and right directions, and the cam roll 63 slides relative to each other in the cam groove 61, and the holding member 4 moves up and down due to the cam action of both of them. Similarly, the vertical position of the arc electrode 3 is adjusted. Since the other configurations are the same as those of the first embodiment, the same reference numerals are used in the drawings, and the explanation thereof will be omitted here.

(Embodiment 3) FIGS. 4 and 5 show an example in which a link mechanism 7 is interposed between the holding member 4 and the adjusting operation means 5. A link operation block 70 is fixedly fixed to the insulating bush 16 similar to the above with a stopper 703, and pins 7 are provided on both sides of the block 70.
Link plates 72, 7 that swing up and down using 1 as a fulcrum
2 is pivoted. Reference numeral 704 indicates the stopper 70
3 is a fastening hole for fixing the block 70 to the bush 16, and as shown in FIG. This is for fastening and fixing, and is similarly employed in the first and second embodiments. E-rings 711, 711 are tied to both ends of the pins 71, 71 to prevent the link plates 72, 72 from coming off.

Elongated holes 721, 721 are drilled in one end of the link plates 72, 72 along the longitudinal direction thereof, and pins fixed to the upper circumference of the holding member 4 are inserted into the elongated holes 721, 721. Both ends of 73, 73 are slidably inserted. A horizontal cylindrical cavity 701 is formed in the block 70, and a slider 74 having a screw 741 is slidably inserted into the cavity 701 along its longitudinal direction. Pins 74 are provided on both sides of this slider 74.
2,742 is fixedly installed, and the pin 742,742
are elongated holes 722, 722 that protrude from large-diameter seat holes 702, 702 opened on the side of the block 70, and whose tips are drilled in the link plates 72, 72.
It is slidably inserted into the

The adjustment operation means 5 includes a female threaded shaft 55 inserted into the cylindrical cavity 701 of the block 70 so as to be rotatable and immovable in the left and right directions, a connecting member 56 fixed to the rear end of the threaded shaft 55, and a connecting member 56 fixed to the rear end of the screw shaft 55. The operating knob 53 is further fixed to the rear end of the member 56, and the screw shaft 55 is screwed into the screw 741 of the slider 74.

In the above configuration, when the operating knob 53 is rotated, the slider 74 slides from side to side within the cavity 701 due to the screwing relationship between the female threaded shaft 55 and the screw 741.
By moving the slider 74 from side to side, the link plate 7
2, 72 are pins 742, 742 and elongated holes 722,
Due to the interaction with 722, the pins 71, 71 are used as fulcrums to swing up and down. And this link board 7
By vertically swinging the holes 721 and 72, the elongated holes 721 and 72
1 and the pins 73, 73, the holding member 4 moves up and down, making it possible to adjust the vertical position of the arc electrode 3. Since the other configurations of this embodiment are the same as those described above, corresponding parts will be given the same reference numerals and their explanation will be omitted. Reference numeral 45 in the figure represents a cooling fin, which is fixed to the upper end of the holding member 4.

Further, in the embodiment, an example of application to a differential pressure casting apparatus is shown, but it is also applicable to a centrifugal casting apparatus. It goes without saying that other changes are possible without departing from the scope of the present invention.

(Effect of the invention) As described above, the arc electrode adjustment mechanism in the precision casting apparatus of the present invention allows the arc electrode 3 to be easily attached to the lower end of the solid rod-shaped holding member 4 from the opening of the normally sealable melting chamber. The vertical position of the arc electrode 3 can be adjusted by the adjustment operation means 5 placed on the front or side of the vertical panel 100 outside the device, and the operation can be performed from the front or side of the panel even during melting. Since this is easy, it is possible to accurately adjust the relative position of the tip of the electrode to the casting material while causing arc discharge. In addition, since there are no artificial operating means for adjusting the electrode position on the head of the device, the top of the device can be covered with a horizontal panel, which is effective for ensuring integrity and preventing electric shock for workers. It is.

[Brief explanation of the drawing]

Fig. 1 is a schematic overall vertical sectional view showing an example of a precision casting machine in which the mechanism of the present invention is adopted, and Fig.
Figure 3 is a diagram similar to Figure 2 of another embodiment, Figure 4 is a diagram similar to Figure 2 of another embodiment, and Figure 5 is a diagram similar to Figure 4. It is an exploded perspective view. Explanation of symbols 1... Melting chamber, 10... Apparatus body, 100... Panel, 16... Insulating bushing, 161... Airtight member, 2... Crucible, 3...
Arc electrode, 4... Holding member, 41... Screw shaft,
5...Adjustment operation means, 6...Cam mechanism, 7...Link mechanism.

Claims (1)

[Claims for Utility Model Registration] A mechanism for adjusting the vertical position of an arc electrode 3 vertically disposed directly above a crucible 2 disposed in a melting chamber 1, the arc electrode 3 being attached to a device main body 10. On the other hand, the holding member is attached to the lower end of a solid rod-shaped holding member 4 which is airtightly and vertically slidably supported via an insulating bushing 16 and an airtight member 161 with a fixing screw 32 so as to be vertically adjustable. The apparatus main body 10 is supported vertically movably through the apparatus main body 10, and its vertical position can be set by an adjustment operation means 5 outside the main body 10. The apparatus main body 10 is surrounded by a vertical panel 100, Adjustment operation means 5 is arranged on the front or side surface of this vertical panel 100, and includes a screw shaft 41 included in the upper part of the holding member 4 and bevel gears 51, 42 connected to the adjustment operation means 5.
or by a cam mechanism 6 or a link mechanism 7 interposed between the holding member 4 and the adjusting operation means 5, the rotational force of the operation means 5 is adjusted to the vertical movement of the holding member 4. An arc electrode adjustment mechanism for a precision casting device, characterized in that the mechanism is adapted to be converted.