JPS5949810B2 - Casting structure for impact type dental centrifugal casting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a casting structure for an impact-type dental centrifugal casting apparatus for casting dental products such as gold crowns and implants.

Conventionally, centrifugal casting in this field involves putting dental metal into a crucible, melting it using heating means such as an arc type, gas type, or high frequency type, and then rotating the crucible and a mold placed near the crucible to apply centrifugal force. The molten metal in the crucible is then cast into a mold.

The advantage of centrifugal casting is that it applies centrifugal force to the molten metal and casts it into the mold with force, and even after casting, the mold is rotated for a certain period of time to continue applying centrifugal force to the molten metal and pressurize it, creating a pushing vortex effect. It is possible to obtain high-quality dental products with precise and precise shapes.

In a typical conventional centrifugal casting device, a crucible and a mold are placed on a single rotating body such as a rotating disk or rotating bar.
After metal melting in the crucible is completed, a rotating body is started and rotated, causing the crucible and mold to rotate at the same time.There is a horizontal type in which the rotating body rotates horizontally due to the rotation of the rotating body. It is divided into two types: the vertical type, which rotates vertically.

However, in conventional equipment, the crucible and mold are simultaneously rotated and poured only after the metal melting is completed, so at the beginning of the rotation, the rotation speed is low and the centrifugal force is not sufficient, causing the molten metal to be poured into the mold. Initially, there was a problem in that the liquid could only flow into the mold with a relatively slow force.

In casting, the initial pouring conditions are an important point in determining the quality of the casting, and it is best to force the molten metal to flow into the mold vigorously before it cools down, but conventional equipment cannot fully satisfy these conditions. was not reached.

The present invention aims to solve the problems of conventional devices and provide a casting structure for a centrifugal casting device that has higher casting performance and better operability. A mold is installed on one side of a mold rotating body provided with a hole, and a crucible rotating body comprising a crucible associated with a heating means for melting metal is loosely inserted into the floating hole. Cast structure for impact type dental centrifugal casting equipment.

The details of the present invention will be explained based on the embodiments shown in the drawings. The present invention can be implemented in both a horizontal type in which the rotating body rotates horizontally and a vertical type in which the rotating body rotates vertically. An intermediate type is a tilting type, in which the rotating body rotates at an angle.

Since the rotating surface of this tilted centrifugal casting device is oblique, it has features that are superior to horizontal and vertical types in terms of device size reduction and ease of operation.

Furthermore, casting equipment is divided into arc type, gas type, high frequency type, etc. depending on the heating means used to melt the metal put into the crucible.The present invention can be carried out using any of these heating methods, but in the examples, argon was used. The so-called argon arc heating method, which performs arc heating in a gas atmosphere, will be explained.

Fig. 1 shows the casing part simply with imaginary lines, a front view of the device implementing the casting structure of the present invention, Fig. 2 is a side view thereof, and Fig. 3 is a vertical sectional view of the main part of the device. .

However, in Figures 1 and 2, for convenience of drawing, the position of the mold rotating body is 90° counterclockwise from the state in Figure 1.
It is shown in FIG. 2 in a rotated state.

The mold rotating body 1 has a mold 2 on one side and a balance weight 3 on the other side, and has a floating hole 4 in the center into which a crucible rotating body 27, which will be described later, is loosely inserted and positioned. The two-stage type large and small balance weights 3, 3 are installed on one side of a rectangular plate 5, and the mold 2 is placed in a mold case 6 on the other side.

To attach the balance weight 3 to the rectangular plate 5, a long groove 7 is bored in the rectangular plate 5, a threaded rod 8 is provided protruding from the lower surface of the lower balance weight 3, and the threaded rod 8 is inserted into the long groove 7.
Insert it into the long groove 7 and fix it with a locking nut 9 at an appropriate position.

A long groove 10 is also bored in the upper balance weight 3, and a threaded rod 11 protruding from the upper surface of the lower balance weight 3 is inserted into the long groove 10 and fixed with a locking nut 12.

Therefore, the upper and lower balance weights 3.3 can be fixed while being moved relative to the rectangular plate 5, and the rotational balance can be adjusted in accordance with the weight of the mold 2.

The mold case 6 connects the inner case 14 to the outer case 13 with the hinge 1.
5, etc., and when fitting the mold 2 into the inner case 14 and casting molten metal, the metal inflow part 2a
After casting, the inner case 14 is rotated as shown by the imaginary line in FIG. 2 so that the mold 2 can be easily pulled out upward.

A stopper 16 prevents the mold 2 from jumping out of the inner case 14, and is rotated around a pin shaft 16a.

The drive mechanism 17 is arranged to rotate the mold rotating body 1, and in the example shown, a rotating gear 18 is connected to the lower surface of the rectangular plate 5 of the mold rotating body 1, and this gear 18 is connected to a motor 19 and The rotation of the motor 19 is controlled by a small gear 20 that appropriately reduces the rotation speed.

The rotary gear 18 is supported by a fixed support frame 23 supporting a gear hollow shaft tube 21 attached by screwing or the like to the lower surface of the rotary gear 18 through upper and lower bearings 22 and 22. As it rotates, it can rotate freely while being fixed in the axial direction.

In addition, the connection between the square plate 5 and the rotating gear 18 is achieved by providing a through hole 24 in the center of the rotating gear 18, standing an annular wall 25 around the through hole 24, and attaching the square plate 5 to the upper part of the annular wall 25. They are individually attached with bolts 26, etc., and inside the annular wall 25 there is a detachable mechanism 6, which will be described later.
An engagement shaft 85, which is a part of 2, is provided inside.

When the square plate 5 is attached to the rotating gear 18, the floating hole 4 of the square plate 5 and the gear hollow shaft tube 21 are connected to each other.
There is continuity between the inside and the inside.

The crucible rotating body 27 is loosely fitted into and located in the free-fitting hole 4 of the mold rotating body 1, and has a crucible 28 installed on its upper surface. In order to effectively supply gas and power for arc heating, the following structure is used.

That is, as a part of the crucible rotating body 27, a receiver of a size that can fit into the floating hole 4 of the rectangular plate 5 in the mold rotating body 1 is provided by screwing a hollow shaft tube 30 into the center of the lower surface of the dish 29. Attachment: This receiver allows the countersunk hollow shaft tube 30 to be inserted into the gear hollow shaft tube 21 at a constant interval, and the receiver is a bearing 31 that attaches the upper part of the countersunk hollow shaft tube 30 to the inner circumferential wall of the annular wall 25. , and the gear hollow shaft tube 21 at the bottom.
It is axially fixed and rotatably supported by a bearing 31 attached to the fixed support frame 23 so as to protrude further.

Further, the receiver plate 29 is placed on the upper surface of the annular wall 25.

On the other hand, a disk hollow shaft tube 34 is attached to the lower surface of the disk body 33 having a through hole 32 in the center by screwing or the like, and the disk hollow shaft tube 34 is inserted upward into the countersunk hollow shaft tube 30. The disk body 33 is inserted into the receiver plate 29, and the disk body 33 and the receiver plate 29 are integrally fixed with bolts 35, etc., and the disk body hollow shaft tube 34 is At the lower part, the receiver projects from the dish hollow shaft tube 30, and a metal electrode disk 36 is attached to the projecting end by screwing or the like.

Therefore, the disc body 33 and the disc body hollow shaft tube 34 rotate integrally when the receiver plate 29 and the receiver plate hollow shaft tube 30 rotate.

The structure of the disc body 33 itself includes an insulating disc body 37, a conductive small disc body 38, and an insulating lower disc body 3 in consideration of the electrical system.
9, an insulating disc body 37 is provided to cover the upper and side surfaces of the conductive small disc body 38, and an insulating lower disc body 39 is brought into contact with the lower face.

A crucible 28 is disposed on the crucible rotating body 27, and a heating means 4 provided on the crucible rotating body 27 or other parts to be associated with the crucible 28.
A torch portion 41 and a small balance weight 42, which are part of the 0, are attached.

The crucible 28 is installed by screwing a metal conductive crucible mount 43 through the insulating disc body 37 with a bolt 44 so as to reach the conductive small disc body 38 at the bottom. The crucible 28 is placed on a crucible mount 43 and fixed with a fixing screw 45.

An electrode rod 46 for generating an arc is provided inside the bottom of the crucible 28, and this electrode rod 46 is in direct contact with the crucible mounting base 43.

The mounting position of the crucible 28 is as follows: when the crucible 28 is in a fixed position, and when the crucible 28 is on the upholstery side as shown in FIG.
is set so that it remains vertical.

Once this setting is made, when the crucible 28 is rotated or moved to another position, that is, to a position other than the upholstery side,
Since the crucible rotating body 27 to which the crucible 28 is attached is inclined, the crucible 28 is in a non-vertical state.

Further, the small balance weight 42 is fixedly installed on the crucible rotating body 27 on the opposite side of the crucible 28 in order to maintain a rotational balance with the crucible 28.

As for the shape of the crucible 28 itself, a conventional shape may be used, but in the embodiment, the upper part of the crucible wall 47 is curved to form a hood 48 and a small chamber 49,
In addition, the crucible 28 has an inner surface that extends from the small chamber 49 to the molten metal outflow portion 28H formed on one side of the crucible 28 and has a smooth curved surface without irregularities.

If a crucible 28 having such a shape is used, even if the crucible 28 first rotates rapidly due to an impact, the molten metal will not overflow out of the crucible 28 due to the hood 48, and the initial impact force will be utilized. Thus, the molten metal can smoothly flow out from the outflow portion 28a.

The configuration of the embodiment of the torch section 41 in relation to the crucible 28 is roughly the same as that used in the conventional argon arc type, with a hood 52 hanging down toward the crucible 28 from an arm 51 attached to a column 50. During installation, the electrode rod 46a is disposed inside the hood 52, and argon gas is ejected from the hood 52 toward the crucible 28, and the electrode rod 46a inside the hood 52 is
An arc is generated between the crucible 6a and the electrode rod 46 of the crucible 28.

The torch portion 41 of the embodiment uses a hollow conductive metal support 50, and electrical wiring (not shown) is provided between the support 50 and the electrode rod 46a so that they are electrically connected. .

The support 50 is attached to the crucible rotating body 27 by attaching the torch section hollow shaft tube 53 to the lower part of the support 50 by screwing or the like, inserting the torch section hollow shaft tube 53 into the disk body hollow shaft tube 34, and then The flange portion 54 is fixed and attached to the insulating disc body 37 with bolts 55.

In addition, the lower part of the torch section hollow shaft tube 53 is a disk body hollow shaft tube 34.
The electrode disc 36a is attached to this protruding end by screwing or the like.

Further, a gas pipe connector 56 made of an insulating material for supplying argon gas is brought into contact with the lower end opening of the torch section hollow shaft pipe 53.

This is done by attaching the main body section 57 to the fixed support frame 23 and inserting the sliding tip tube 58 into the main body section 57, so that the tip of the sliding tip tube 58 is elastically connected to the torch section hollow shaft tube 53 by a spring 59 fitted in the main body section 57. It abuts on the lower end opening, and 60 is a gas supply pipe.

In addition, in order to maintain the distance between each axis and ensure electrical insulation,
A cylindrical insulating sleeve 61.degree. 613 of an appropriate thickness is fitted over the disk body hollow shaft tube 34 and the torch section hollow shaft tube 53 as required.

The attachment/detachment mechanism 62 transmits the rotation of the mold rotating body 1 to the crucible rotating body 27 in a loosely fitted state, rotates both together, and, in the integrally rotating state at the time of fitting, closes the outflow portion 2 of the crucible 28.
This is a mechanism in which 8a faces the metal inflow part 2a of the mold 2, and since the example uses an argon arc type, in addition to the above-mentioned attachment/detachment function, it also performs the functions of supplying argon gas and supplying arc current. shows.

The attachment/detachment mechanism 62 of the embodiment has an inclined plate 64 fixed to the front position of a fixed base 63, an operating shaft 67 provided with a bundle shaft 65 and a cam 66 fixed thereon, inserted through the inclined plate 64, and an operating shaft support 68 The operating shaft 67 is supported at the bending point of the shaft, and is connected via a universal joint 69 to an opening/closing shaft 70 that opens and closes electrode brushes 99 and 99a, which will be described later.

This opening/closing shaft 70 is supported horizontally on the individual base 63 by bearings 71, 71, and has two cams 72, 721 attached to the rear thereof.

In front of the operating shaft 67 of the inclined plate 64 is a bearing 73.73.
An extrusion shaft 75 is disposed which is supported by a pull-back spring 74 and is fitted with a pull-back spring 74, and the rear end of the extrusion shaft 75 is elastically brought into contact with the cam 66 by the force of the spring 74.

The attachment/detachment mechanism 62 in the embodiment casting apparatus is operated by the above-mentioned bundle shaft 65 to open/close the opening/closing shaft 70 and the extrusion shaft 75.
is operated to transmit rotation from the mold rotating body 1 to the crucible rotating body 27 and to supply argon gas and arc current.

That is, to describe the rotation transmission mechanism from the mold rotating body 1 to the crucible rotating body 27, 76 is the annular wall 2 of the rotating gears 1 and 8.
5, which is a lever device attached to the support sleeve 7.
7 is fixed to the annular wall 25, a sliding shaft 78 is inserted into this support sleeve 77, and a lever 79 is rotatably mounted on one end of the sliding shaft 78 with a support shaft 80, while a lever 79 is attached to the outside of the support sleeve foot. An L-shaped support member 81 is fixedly attached to the lever 79, and its end is rotatably attached to the intermediate portion of the lever 79 with a support shaft 82.

Therefore, when the tip 79a of the lever 79 is moved up and down, the lever 79 moves like a balance around the support shaft 82.
The end of the lever 79 supports the sliding shaft 78 on the support sleeve 77.
Slide and move inside.

Further, the sliding shaft 78 has a spring 83 externally fitted within the support sleeve 77, and one end of the spring 83 is placed on the inner wall of the support sleeve 77, and the other end is provided on the vertical wall 8 surrounding the sliding shaft 78.
4 to elastically press the sliding shaft 78 toward the inside of the annular wall 25.

On the other hand, a vertical hole 86 is provided inside the annular wall 25 into which a substantially cylindrical engagement shaft 85 is inserted.
A through-hole 8 is formed with a tapered groove 87 having a length of about a quarter circumference as shown in the figure, and is large enough to allow a stopper pin (described later) to be inserted into and removed from the deepest part 87a at one end of the tapered groove 87.
There are 8.

Also, a stopper pin (L89
A stopper pin 90 is inserted into this hole 89, and the lower end of the stopper pin 90 is normally pulled up and positioned within the disc body 33 by a spring 91 fitted onto the stopper pin 90. .

The function of the engagement shaft 85 is to temporarily maintain an engaged state with the sliding shaft 78, and when engaged, the entire engagement shaft 85 is pushed into the annular wall 25, and when disengaged, it is engaged by the force of the spring 92. axis 85
In the embodiment, the diameter of the lower part of the substantially cylindrical body is reduced and the spring 92 is fitted onto the outside, and an inclined sliding surface 93 is provided on the side wall from the center to the top of the substantially cylindrical body. and an engagement recess 94 connected thereto.

The function of the stopper pin 90 is to move the engagement shaft 85 to the sliding shaft 7.
8, the upper end of the engagement shaft 85 is pressed and moved downward, and is normally in a position where it is pulled upward by a spring 91.

What is shown in FIG. 3 is the tip of the sliding shaft 78 and the engagement shaft 85.
The upper end of the engagement shaft 85 protrudes from the upper surface of the annular wall 25, the receiver fits into the tapered groove 87 of the plate 29, and the receiver of the crucible rotating body 27 is in a state of engagement with the plate 29. At this time, the rotation of the mold rotating body 1 is transmitted to the crucible rotating body 27.

As shown in a simplified state in FIG. 4, the electrode brush opening/closing mechanism includes roughly U-shaped brush frames 95, 95a connected to electrical wiring 96, 96a, which are integrally arranged facing each other.
The upper part is fixed to the support frame 2 via an insulating bushing 97°97a.
3, an insulating support 98 whose lower part is placed on the base 63
, 98a, and comes into contact with the electrode discs 36, 36a at the upper tips of the brush frames 95, 95H.
9.99a, and an insulating cam contact portion 10 that contacts cams 72, 723 fixed to the opening/closing shaft 70 at the lower tip.
0,100a, and further brush frames 95,95
Spring 101.degree. 101a is fitted above and below H so that brushes 99, 99a and cam contact portions 100,100a resiliently abut against electrode plates 36,36a and cams 72,72a.

Also, a limit switch 10 that opens and closes a gas supply solenoid valve (not shown) on a fixed base 63 or the like? At the same time, it is brought into contact with the brush frame 95a, and is operated by utilizing the movement of the brush frame 95a.

What is shown in FIGS. 8 and 9 is a simplified explanatory diagram showing the operation of the cam 66 of the operating shaft 67 and the cams 72, 72a of the opening/closing shaft 70.
The cam 66 of the operation shaft 67 is an eccentric cam and forms a stepped portion 103, a mold rotation recess 104, a crucible rotation recess 105, and a brush opening operation four portions 106, and the cam 72 of the opening/closing shaft 70
, 72a are circular cams having protrusions 107, 107a.

The bundle shaft 65 is initially positioned laterally to the right as shown in FIGS. 1 and 8, and at this time the push shaft 75 is in contact with the stepped portion 103 of the cam 66.

When the bundle shaft is rotated clockwise, for example, by 90 degrees, the extrusion shaft 75 fits into the mold rotation recess 104, and the movement of the rotation angle of 90 degrees during this time is detected by a limit switch (not shown). A projection (not shown) is provided on the operation shaft 67 or the opening/closing shaft 70, and the limit switch is made to correspond to the projection, and the motor 19 is activated to rotate the mold rotating body 1.

Further, since the cams 72, 72a of the opening/closing shaft 70 are circular, even if the opening/closing shaft 70 rotates 90 degrees, the cam contact portions 100, 10
0a maintains the contact state as it is.

When the bundle shaft 65 is further rotated by 90 degrees, the extrusion shaft 75 is fitted into the crucible rotating portion 105, and since the cam 66 is an eccentric cam, the extrusion shaft 75 is pushed out a certain length toward the lever device 76 in front, and the extrusion shaft 75 is pushed out. The shaft 75 is a lever device 76
Acting on the crucible rotating body.

Rotate 27.

At this time, the projections 107 of the cams 72, 72a of the opening/closing shaft 70.
107a does not come into contact with the cam contact portions 100, 100a, and the brushes 99, 991 maintain their contact state.

Then, when the bundle shaft 65 is further rotated, for example, by 30° to 45°, the push-out shaft 75 is fitted into the four parts 106 for opening and closing the brush.
The protrusions 107, 107a of a are the cam contact parts 100, 100
a, and pushes the cam contact portion 4100.100a to the left and right, and as a result, the brushes 99,
99a separates from the electrode disks 36, 36a, and the supply of current is cut off.

In addition, the push-out shaft 75 for operating the lever device 76
The extrusion mechanism shown in FIG. Any mechanism that can be used to push it away is sufficient.

The configuration of the device implementing the casting structure of the present invention is as described above, and its operation is as follows at the time when the previous casting is completed.
As shown in FIG. 3, the engagement shaft 85 is in a state of engagement with the plate 29, and the rotation of the mold rotating body 1 is transmitted to the crucible rotating body 27 via the engagement shaft 85. ing.

Therefore, when a new casting is to be performed, it is necessary to disengage the square engagement shaft 85 and the receiving plate 29. Therefore, by pressing the stopper pin 90 downward by hand, the stopper pin 90 The lower end of is in contact with the upper end of the engagement shaft 85,
Push and move the engagement shaft 85 downward.

On the other hand, the tip of the sliding shaft 78 is connected to the inclined sliding surface of the engaging shaft 85;
However, as the engagement shaft 85 moves downward, its tip slides on the inclined sliding surface 93 toward the engagement recess 94.
It moves and fits into the engagement recess 94, and the sliding shaft 78 and the engagement shaft 85
The entire engagement shaft 85 enters into the annular wall 25, and the plate 29 of the crucible rotating body 27 is inserted into the mold rotating body 1.
It becomes a loose fit state.

At this time, in the lever device 76, the tip of the sliding shaft 78 fits into the engagement recess 94, so that the sliding shaft 78 is moved toward the engagement shaft 85 by the force of the spring 83, and the support sleeve 77
Therefore, the lever 79 is pulled toward the engagement shaft 85 at the support shaft 80 and is set in a slightly rotated state about the support shaft 82 .

When the sliding shaft 78 and the engaging shaft 85 engage, the crucible rotating body 27
can be rotated by hand regardless of the mold rotating body 1,
If the crucible 28 is positioned at the right end as shown in FIG.
It will be in a state opposite to 6.

Further, the brushes 99, 99a are in sufficient contact with the disk body hollow shaft tube 34 of the crucible rotating body 27 and the torch portion hollow shaft tube 53 at the electrode disks 36, 36a by the force of the springs 101, 101a, so that a certain strength is maintained. Since the brake is applied, the crucible rotating body 27 does not rotate by itself due to the weight of the crucible 28 or the like.

After setting the position of the crucible 28, put the dental metal 108 into the crucible 28, operate the power button and gas cock (not shown), and one line of arc current will be connected to the electrical wiring. Electricity is supplied from the brush frame 95 connecting the brush 96 to the small disc body 38 through the brush 99, the electrode disc 36, and the disc body hollow shaft tube 34, and then from there through the bolt 44 and the crucible mount 43. The electrode rod 46 of the crucible 28 is energized.

The other system is from the brush frame 95a to the brush 99a.
, the electrode disk 36a, the torch section hollow shaft tube 53, the pole 50 is energized, and from the pole 50 the electrode rod 4 in the hood 52 is energized.
6a is energized.

Further, argon gas is supplied from the gas connector 56 into the torch hollow shaft tube 53, passes through the support 50 and the arm 51, reaches the hood 52, and flows towards the crucible 28 so as to surround the electrode rod 46a. An eruption takes place.

In the above initial setting state, the first arc start is performed by a general arc generator (not shown), an arc is generated between the electrode rods 46 and 46a, and the metal 10
8 heating and melting is performed.

Next, when the molten metal is almost completed, the bundle shaft 65 is rotated by a certain angle, for example, 90 degrees, and the aforementioned operation shaft 65 is rotated.
The motor 19 is started by the rotation of the cam 66 of No. 7, and rotates the small gear 20, the rotating gear 18, and the mold rotating body 1.
The mold 2 is rotated around the crucible 28 at a constant speed.

Since the balance weight 3 is disposed on the mold rotating body 1 so as to face the mold 2, its rotation is smooth without violent shaking.
The brushes 99, 99a are connected to the springs 101, 101a
Since they are in sufficient contact with each other, they remain in a stationary state reliably.

At this time, constant regular vibrations caused by the 10 rotations of the mold rotor are transmitted to the metal in the process of melting in the crucible 28, causing it to also vibrate.

When the metal melting is completed, the bundle shaft 65 is further rotated by a certain angle, for example, 90 degrees, in order to carry out casting, and the cam 66 of the operating shaft 67 rotates.Since this cam 66 is an eccentric cam, the extrusion shaft 75 is rotated at a constant angle. The lever 79 is pushed out toward the long lever device 76 and rotates with the tip of the pushing shaft 75.
The tip 79a of the lever 79 makes contact with the tip 79a of the lever 79, and the lever 79 instantly
The sliding shaft 78 is rotated slightly counterclockwise in FIG. The engagement shaft 85 is disengaged from the engagement recess 94, and the inclined sliding surface 93 slides while contacting the tip of the sliding shaft 78.
5 protrudes a certain length from the upper surface of the annular wall 25 by the force of a spring 92, and its protruding end contacts the tapered groove 87 of the plate 29, and the engagement shaft 8 rotates with the rotation of the mold rotor 1.
5 slides in the tapered groove 87, and when it reaches the deepest part 87a of the tapered groove 87, the engagement shaft 85 and the receiver plate 29 engage,
The crucible rotating body 27 rapidly rotates together with the mold rotating body 1.

Here, the crucible 28 is rapidly rotated impulsively with its outflow part 28a facing the metal inflow part 2a of the mold 2, and the molten metal in the crucible 28 is flown forcefully toward the mold 2 with a large centrifugal force. .

If a crucible 28 having a hood 48 and a small chamber 49 as in the embodiment is used, even when the first impact is applied to the crucible 28, since the hood 48 is present, the molten metal will not flow out of the crucible 28. Moreover, the small chamber 49 has an inner surface shape that absorbs and inflows the molten metal that tends to climb up the wall of the crucible 28 due to the impact force, and uses the impact force at that time to smoothly transport it to the outflow opening 28a. This allows the molten metal to flow into the mold 2 with sufficient force without wasting it.

When the bundle shaft 65 is operated and the extrusion shaft 75 is fitted into the four crucible rotating parts 105 of the cam 66, the crucible rotating body 27 starts rotating as described above, but the brushes 99, 99a are still used in the electrode opening/closing mechanism. remains in elastic contact with the electrode discs 36, 36a.

This is because there is a slight time delay before the pushing shaft 75 acts on the lever device 76 and the engaging shaft 85 and the receiver engage with the plate 29, so when the pushing shaft 75 acts on the lever device 76, If the brushes 99, 99a are separated from the electrode disks 36, 368 at the same time, the crucible rotating body 27 will be dragged by the rotating mold rotating body 1 until the engagement is complete, for example. The receiver is plate 29
This is because the rotation occurs due to contact between the lower surface and the upper surface of the annular wall 25.

To prevent this, the crucible rotating body 2 is attached to the brushes 99, 993.
7 is provided with a braking function by friction, so that even if the mold rotating body 1 is rotating, the crucible rotating body 27 remains stationary until the engagement is complete.

Therefore, even if the engagement is completed and the crucible rotating body 27 rotates, if the bundle shaft 65 is not operated again, the brushes 99, 9
9a contacts the electrode disks 36, 36a and continues to apply the brake, but the rotational force of the mold rotating body 1 is stronger than that, and the braking force is applied to the mold rotating body 1 and the crucible rotating body after engagement. There is no effect on the rotation with 27.

When it is confirmed that the engagement is completed, the bundle shaft 65 is further rotated by a certain angle, for example, 45 degrees, and the pushing shaft 75 is fitted into the brush opening recess 106 of the cam 66, and the rotation of the operating shaft 67 is stopped. The opening/closing shaft 70 is rotated via the universal joint 69, and the cams 72, 72 of the opening/closing shaft 70 are rotated.
a is the projection 107.107a of the flyer frame 95,95
a, and push the cam contact parts 100 and 100a outward to the left and right, and then
5. Move the entire 95a to the outside to remove the brush 99°99a from the electrode discs 36, 361.

As a result, the current supply to the electrode rods 46, 46a is stopped and the arc is extinguished.

In addition, in the gas supply system, as the brush frame 95a moves, the brush frame 95a comes into contact with the limit switch 102 attached to the fixed base 63, actuating it, and causing the gas supply solenoid valve (
(not shown) is closed to stop the gas supply to the gas connector 56.

After a certain period of time has elapsed after the molten metal 108 is cast in this manner, the rotation of the motor 19 is stopped by returning the bundle shaft 65 to its initial state or pressing a motor stop button (not shown), and casting is completed. It is something to do.

As described above, the casting structure of the present invention is implemented in a centrifugal casting apparatus, and only the mold 2 is rotated at a constant speed around the crucible 28 before the metal melting in the crucible 28 is completed, and after the melting is completed, the crucible 28 is rotated impulsively and rapidly in line with the mold 2, so that the molten metal flows into the mold 2 with sufficient force from the beginning of casting, so that the molten metal flows into the mold 2 sufficiently. It is possible to obtain high-quality dental products that are press-fitted and have a precise and precise shape.

Further, since the metal in the crucible 28 is subjected to a certain prescribed vibration by the rotation of the mold rotor 10, effective metal melting is carried out.

In other words, it is better to heat a metal that is in a dynamic state due to vibrations than to heat a stationary metal.
Therefore, the metal is not locally abnormally overheated, is heated uniformly, and the melting of the metal can be completed at a temperature slightly higher than the metal melting point.

As a result, the metal is uniformly melted without being abnormally overheated in the arc irradiated area, so conventionally the temperature difference between the molten metal temperature at the arc irradiated area and the surrounding molten metal temperature is within 100°C. This simplifies the process of melting all the metal in the crucible and casting within this temperature difference range, and therefore there is no abnormally overheated part of the molten metal, so there is no thermal influence on the mold. This eliminates decomposition and provides cast products with a clean cast surface without seizure.

Furthermore, the amount of metal to be melted was conventionally required to be about three times the amount of the product, but in the present invention, it was confirmed through the following experiment that the amount could be slightly less than twice.

That is, cobalt chromium 18
g is melted using an apparatus implementing the casting structure of the present invention, and 9
When cast into a mold heated to 00°C, a product with a clean casting surface without seizure was obtained.

This is because conventional centrifugal casting equipment uses the pouring pressure from the feeder, which requires melting approximately three times as much metal as the casting, but with the present invention, centrifugal force is This is because the strong setting makes it possible to cast even a small amount of molten metal.

Next, the casting structure of the present invention is characterized in that the disc-shaped crucible rotating body 27 is fitted and positioned in the center of the mold rotating body 1, so that the rotation of the crucible rotating body 27 is caused by the mold rotating body. 1
It is possible to rotate stably without shaking due to 0 rotation,
Molten metal is poured smoothly and the momentum of the casting is not reduced.

Further, when the apparatus according to the present invention is used as an argon arc type, as illustrated, the crucible rotating body 27
The support tube, which is a support tube, has a disc body hollow shaft tube 34 and a torch section hollow shaft tube 53 inside the dish hollow shaft tube 30, so that the gas and electrical systems can be integrated without drawing electrical wiring etc. inside. This makes it possible to downsize the entire casting apparatus and eliminate troubles such as disconnection of wiring.

The attachment/detachment mechanism 62 that transmits the rotation of the mold rotating body 1 to the crucible rotating body 27 so that both of them rotate integrally may include a mechanical clutch having an engaging pawl or an electric electromagnetic clutch other than the illustrated embodiment. However, as in the embodiment, by operating the bundle shaft 65, the lever device 76 is actuated and the engagement function of the engagement shaft 85 allows the rotating body 1 to be
, 27, it can be functionally simple and compact, and there are fewer troubles such as breakdowns.

In addition, in the embodiment, the mechanism uses cams 72, 72a, etc. so that the above-mentioned engagement function can be operated by operating one bundle shaft 65, and the electricity/gas supply line can also be opened and closed. A series of operating processes from the first rotation to the completion of casting can be performed in sequence with a single bundle shaft 65, making the operation extremely easy.

[Brief explanation of the drawing]

Fig. 1 is a front view of a casting device implementing the casting structure of the present invention with a partial section around the crucible, and Fig. 2 is a side view of the mold rotor shown in Fig. 1 rotated 90 degrees counterclockwise. , FIG. 3 is a partial vertical sectional view of the main part of the casting device, FIG. 4 is a simplified perspective view of the electrode disc opening/closing mechanism with the fixed support frame partially cut away, and FIG.
The figure is an exploded arrangement view of each hollow shaft tube, FIG. 6 is a perspective view of the receiver as seen from diagonally below the dish hollow shaft tube, and FIG. 7 is a central sectional view of the crucible.
FIG. 8 is a simplified explanatory diagram of the operation of various cams, FIG. 9 is a side view of FIG. 8, and FIG. 10 is a front view of the operating shaft cam. 1... Mold rotating body, 2... Mold, 4...
...Idling hole, 17... Drive mechanism, 18.
...Rotating gear, 27... Crucible rotating body,
28... Crucible, 40... Heating means, 6
2... Attachment/detaching mechanism, 76... Lever device.

Claims (1)

[Claims] 1. A mold 2 is installed on one side of a mold rotating body 1 having a floating hole 4 in the center, and a crucible rotating body 27 equipped with a crucible 28 associated with a heating means 40 for metal melting is attached to the floating hole 4.
A casting structure for an impact-type dental centrifugal casting device, characterized in that it is loosely inserted into the shaft.