JP2602206Y2 - Mold casting machine for precision casting - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for extracting a mold used for separating a mold from a short tubular mold after precision casting of a metal material such as a small craft or a dental prosthetic material and a ceramic material. .

[0002]

2. Description of the Related Art In precision casting used in the field of dental prostheses, a crown to be refilled is used while using an articulator based on a jaw plaster model in which an impression is taken from the oral cavity and a dentition is reproduced. The shape of the wax crown is cast with wax, the mold filler is poured into the wax crown, and after curing, it is heated and dewaxed to form a mold in which the shape of the wax crown is precisely formed in the mold gap. 2. Description of the Related Art A method of casting a molten corrosion-resistant metal or ceramics into a mold by a centrifugal casting machine, a differential pressure casting machine, or the like has been widely used.

In this molding operation, a short steel tube is used as a mold (commonly called a ring or a casting ring), and the wax crown is attached to the tip of a conical rubber forming a feeder. Then, the conical rubber is brought into contact with the opening of a steel circular pipe as a mold, the wax crown is arranged in the mold, and the mold filler slurry is poured into the voids in the mold. Vibration filling is performed up to the full opening of the circular tube, and then dried and hardened. After the filler has hardened, it is heated or injected with a special liquid agent to dewax it into a mold.After precision casting, the mold is allowed to cool down, the mold is removed from the mold, the mold is subdivided, and the casting Take out.

[0004] In precision casting for crafts, the wax itself is molded into a desired shape and pattern in a one-piece production, and from the wax mold, a circular tubular form and a conical rubber similar to the above are used to substantially form the wax. In a similar procedure, a metal mold for molding such as gold and silver is precisely cast by a centrifugal casting method or the like.

[0005]

In the manual work for removing a mold from a mold after casting, the mold is fixed, and the sharp tip of a special tong (forceps) is fixed to the outer surface of the body of the mold and the opening of the mold. The mold is pressed several times into the mold by forcefully contacting the mold surface of the part, but the mold is stuck to the inner surface of the mold and it takes time to remove the mold. , And also required the skill and skill.

[0006] Especially in dental casting, the cast metal crown needs to be slightly larger than the correctly prepared wax crown to facilitate attachment to the remaining teeth in the oral cavity. For this reason, as the mold filling material, a compounding material which causes volume expansion in the process of drying and hardening from a liquid mud state is selected. As a result, the mold material is firmly fixed to the inner surface of the mold due to expansion, so that when the mold is extracted, the tip of the tongue is recessed from the surface of the mold to the rear surface, and the mold cannot be extracted. However, troubles such as making the mold unusable by hitting the mold and hitting the tongue with excessive force to drop the form to the floor were inevitable.

In addition, as a device for mechanically extracting, a formwork is placed on a gantry with its casting opening facing downward, and a rack that meshes with a pinion is hung above an upright column erected on the gantry to drop the pinion. Attempts have been made to rotate the handle with the handle and press the bottom of the mold inside the mold with the tip of the rack.However, the handle is large and around the horizontal axis in order to secure the pressing force required for extraction. However, there is a problem that the size is limited to a fixed type, and the dust from the mold is clogged in the rack, making it inoperable.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a mold removing device for quickly and easily removing a cast mold from a mold.

[0009]

SUMMARY OF THE INVENTION A precision casting mold withdrawal device of the present invention is a device for removing a mold from a short tubular mold filled with a mold material after precision casting, and comprises: A mold mounting table provided with an opening in which a mold can pass, a screw receiving portion provided on an upper portion of a support erected on the base, and an opening screwed into the screw receiving portion. A lifting screw shaft that moves up and down the upper part, a handle that rotates the screw shaft,
A pressure end member pivotally attached to the lower end of the screw shaft and having a surface for pressing the upper surface of the mold.

The form mounting table of the present apparatus is disposed above the apparatus base, and the periphery of the opening directly or indirectly supports and supports the tube end of the form, and the inside of the opening can pass through the mold. It is said that.

Particularly preferably, the screw receiving portion is provided with a guide surface for vertically slidably supporting the lifting screw shaft in an inner space where the lifting screw shaft is loosely fitted, and the space on the opposite side of the guide surface. On the lower end side, a meshing part formed with a thread groove meshing with the screw thread on the outer periphery of the elevating screw shaft is axially supported on the horizontal axis of the cavity side wall and elastically urged to the screw shaft side by a compression spring, In some cases, the upper end side of the engaging portion projecting from the empty space serves as an operating lever for releasing the engagement.

[0012]

In the form removing device of the present invention, an opening through which the mold can pass is provided in the form placing table, and the pipe end of the form is placed and supported on the periphery of the opening. Then, the mold is placed so that the tube end is in contact with this step, and the lower surface of the pressure end member pivotally attached to the lower end of the elevating screw shaft is brought into contact with the upper surface of the mold inside the mold to raise and lower the elevating screw shaft. If it is turned down with the handle,
Pressing the bottom of the mold downward allows the mold to slip out of the mold.

[0013]

FIG. 1 is a front view including a partial cross section of the present apparatus, and FIG. 2 is a perspective view thereof. Left and right supports 2, 2 are erected, and the two supports 2, 2 are united integrally at an upper portion to form a screw receiving portion 3. The screw receiving portion 3 has a vertically movable screw shaft 5 vertically. An arm 62 for rotation is provided at the upper end of the screw shaft 5.
A handle 6 erected at the end of the arm 62 is fixed, and a pressing end member 7 is pivotally attached to the lower end of the lifting screw shaft 5.

A base upper surface 11 is provided between the left and right columns 2 and 2.
Is provided with an appropriate space 10 between them, and the form mounting table 4 is erected. The form mounting table 4 is substantially in the form of a thick plate, and the side edges 44, 44 on both sides thereof are supported by the columns 2, 2. Are fitted into notch grooves 24, 24 provided on the opposite side surfaces, and are screwed and held by stoppers 28.

A circular opening 40 penetrating from the front to the back is provided substantially at the center of the form mounting table 4.
The central axis is arranged so as to be substantially coaxial with the axis of the elevating screw shaft 5.

FIG. 1 shows an embodiment in which the mold 8 is directly mounted on the mold mounting table 4 and the mold is removed. A step 42 is formed in the opening 40 at the periphery of the upper surface thereof. Have been
The tube end 82 of the mold 8 is placed on the step surface of the step 42, and the inside diameter of the opening 40 is slightly larger than the outside diameter of the mold 9.

Therefore, in use, the pipe end 82 of the mold 8 is placed on the step portion 42, and the screw shaft 5 is lowered to lower the pressurizing end member 7 so that the lower surface of the pressurizing end member 7 is in the mold 9 in the mold 8. Abut on the lower surface 91. Further, the handle 6 is rotated to raise and lower the screw shaft 5.
When the pressing end member 7 is pressurized, the mold 9 is extracted from the mold frame 8, passes through the opening 40, and falls on the upper surface 11 of the base 1.

The screw receiving portion 3 may be a screw hole through which the elevating screw shaft 5 is directly screwed and inserted. However, preferably, the screw receiving portion 3 is provided with a rapid feed mechanism for quickly elevating the elevating screw shaft 5 as described below. Is adopted.

FIG. 3 shows a sectional view (A) and a cutaway perspective view (B) of the rapid feed mechanism.
Is formed as a trapezoidal screw, and a cylindrical guide surface 31 on which the screw outer peripheral surface 55 of the lifting screw shaft 5 is slidably movable up and down is formed in the inner space 30 of the screw receiving portion 3. Face 3
1 is provided with a thread groove 3 for engaging with the trapezoidal screw.
A meshing piece provided with a meshing body 32 formed with 21 is supported by a horizontal shaft 34, and an upper portion of the meshing piece protrudes outside the extraction space to form a meshing lever 33.

The back of the meshing body 32 is pressed by a compression coil spring 35 so that the meshing body 32 is always in the thread groove 3.
The screw groove 321 is elastically urged in the direction of 21, and is firmly engaged with the screw thread 55 on the outer periphery of the lifting screw shaft 5. or,
When the meshing lever 33 is operated to retract the meshing member 32 of the meshing piece against the elastic force of the compression coil spring 35, the meshing between the meshing body 32 and the outer periphery of the lifting screw shaft 5 is released.

In a state in which the meshing body 32 and the elevating screw shaft 5 are engaged, the handle 6 is rotated to press the pressing end member 7 of the elevating screw shaft 5.
When the lower surface of the mold presses the upper surface 91 of the mold 9, the upward reaction force received by the elevating screw shaft 5 is applied to the screw groove 32 of the engagement body 32.
Since it is received by the horizontal shaft 43 via 1, the mold 9 can be pressurized.

On the other hand, if the meshing state of the meshing body 32 and the lifting screw shaft 5 is released by the meshing lever 33, the lifting screw shaft 5 can be grasped with fingers and moved freely up and down. Therefore,
After the mold 8 is placed on the mold placing table 4, the pressing end member 7 can be set very quickly on the upper surface of the mold 9, so that the engaging lever 33 is immediately returned and the handle can be slightly turned. If you can, you can die.

Further, when the screw 9 is used for the screw receiving portion 3 and the casting operation of the casting mold 9 is performed many times,
There is a problem that the powder of the mold filler is adhered to the elevating screw shaft 5 due to the peeling of the shaft, and the elevating screw shaft 5 cannot rotate at the screw receiving portion 3.
Since the space 30 is large inside the screw receiving portion 3, there is no such a disadvantage, and there is an advantage that dust can be easily removed and cleaned by brush cleaning or air blowing.

In order to cope with different shapes and sizes of a casting to be cast, two or more types of molds 8 having different outer diameters and heights, usually several types, are prepared and used as appropriate. 1, the inner diameter of the opening 40 of the mold placing table 4 is made slightly smaller than the outer diameter of the mold, and the step at the upper edge of the opening is formed by the pipe end 81 of the mold 8 as shown in FIG. A mold mounting table 4 having a cross section that can be mounted is prepared for each mold dimension, and a mold mounting table 4 corresponding to the mold 8 used for casting is selected to cut the columns 2. A method of replacing and using the notched grooves 24, 24 is adopted.

In another method, as shown in FIG. 2, a large-diameter opening 40 corresponding to the maximum-diameter mold 8 among a group of molds used for casting is formed in the mold mounting table 4 as shown in FIG. In order to use another formwork, as shown in FIG. 4, a relay ring 45 for placing the formwork is provided between the opening 40 of the formwork mount 4 and the pipe end 81 of the formwork 8. A method of intervening is also used. The form mounting relay ring 45 has an outer periphery corresponding to the step 42 of the opening 40 of the form mounting table 4, and a step corresponding to the pipe end 81 of the form 8 on the inner periphery. And the inner diameter of the inner circumference is
The outer diameter of the mold 9 is slightly larger than the outer diameter of the mold 9, and several types of such relay rings 45 are prepared according to the form 8. In this method, the form-mounting table 4 is attached to the base support 2.
It may be fixed integrally to the vehicle.

As a third method, as shown in FIG. 5, openings 40 having different inner diameters are formed through the four surfaces of the hollow rectangular tube 4 so as to correspond to the molds 8 having different outer peripheries. Body 4
Is replaced with the form mounting table 4 shown in FIG.
Alternatively, a method of directly mounting on the upper surface 11 of the device and using the form mounting table 4 can be used. For centering the opening 40 with respect to the elevating screw shaft 5, a suitable pair of engagement pins 46 are provided on the outer surface of the cylinder.
A pair of pin holes 47 are formed on the upper surface 11 of the base 1 to receive the engaging pins. Positioning is performed by fitting the engaging pins 46 into the pin holes 47. .

FIG. 4 shows a detailed relationship between the form mounting table 4, the form 8 and the elevating screw shaft 5, and in FIG. A spherical socket 72 for receiving the spherical body 52 is formed on the upper side of the other pressing end member 7 so that the pressing end member 7 is pivotally swingable. 71 is formed in a planar shape.

As shown in FIG. 1, the mold surface 91 may be directly pressed by the lower surface 71 of the pressing end member 7, but in the example of FIG. A disk 75 having a diameter slightly smaller than the inner diameter of the mold is interposed between the inner mold surface 91 and the inner mold surface 91 to press the mold surface 91. This disk 75
Several pieces are prepared according to molds having different inner diameters.
In the case where the mold surface 91 has an uneven surface when the mold filler 8 is filled in the mold 8, the disk 75 is moved to the mold surface 9.
Since 1 is pressed on average, it is possible to prevent the mold 9 from being damaged at the time of extraction.

As shown in FIGS. 4A and 4B, the pressing end member 7 and the disk 75 are integrated into a plurality of disks 75 having different outer diameters.
The other lifting screw shaft 5 is formed with a small rod 51 projecting from the leading end thereof into contact with a concave portion or a spherical socket 72, and this disk 75 is used as the pressing end member 7. Can also.

In this embodiment, a grip portion 27 capable of gripping in the palm is formed on one of the upper columns 22 of the right and left columns 2 and 2, and this portion is held by one hand and the other is held. The handle 6 can be turned by hand for easy operation, whereby the device can be made portable. However,
The base may be fixed to the work table by screws.

On the other hand, the handle 6 is provided with an extending arm 61 protruding from the mounting portion 63 of the lifting screw shaft 5 to the arm 62 on the handle side on the opposite side. At the time of use of this apparatus, the pressing end member 7 or its disk 75 is set on the upper surface of the mold 9 in the mold 8 on which it is placed. 62
Is gripped by the remaining fingers and twisted around the elevating screw shaft 5, since the firm fixation of the mold 9 to the mold frame 8 is released. When the handle 6 is thereafter rotated, the mold 9 is easily pushed down. Can be extracted. The handle 6 may be an upright one that is mounted on a torus in which the center of the hub is attached to the lifting screw shaft 5. It is convenient that the torus ring can be gripped around the circumference of the ring of the torus and similarly turned around the elevating screw shaft 5.

Further, in this embodiment, the configuration in which the two right and left columns 2 and 2 are erected is shown. However, only one column is erected and the form mounting table 4 and the Grip part 2 at the top
7 can be provided to integrally form the screw receiving portion 3. The cross-sectional shape of the column 2 may be tubular, cylindrical, thick plate or any other shape, or the entire device may be a box-shaped container and the wall may be used as a column, which is not excluded from the present invention. Absent.

As a material constituting the present apparatus, cast iron is the best in terms of formability and economical efficiency, but in terms of weight reduction, a portion of aluminum alloy casting or hard synthetic resin (ABS resin, polyamide resin, etc.) is used. Use is also possible.

[0034]

[Effects of the Invention] The precision casting mold removal device of the present invention
The tip of the lifting screw shaft screwed into the screw receiving part on the upper part of the support is pressed against the upper surface of the mold in the fixed mold, and the mold is pulled out, completely eliminating the inconvenience caused by manual work,
Extraction can be performed reliably and easily.

Since the screw receiving portion employs a rapid feed mechanism, the elevating screw shaft can be set in the mold in a very short time, which is effective for improving workability. , Dust-proof cleaning can be easily performed.

[Brief description of the drawings]

FIG. 1 is a front view including a partial cross-sectional view of an embodiment of a precision casting mold withdrawing device of the present invention.

FIG. 2 is a perspective view of the precision casting mold withdrawing device of the present invention.

FIG. 3 is a partial sectional view (A) and a partial perspective view (B) of a screw shaft rapid feed mechanism used in the precision casting mold withdrawing device of the present invention.

FIG. 4 is a detailed relational diagram (A) of the formwork mounting table, the formwork and the elevating screw shaft of the precision casting mold unloading apparatus of the present invention, and a pressurizing end according to another embodiment of the tip of the elevating screw shaft. Sectional drawing (B) of a member and its perspective view (C).

FIG. 5 is a sectional view (A) and a perspective view (B) of a box-shaped form mounting table.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 base 2 support 3 screw receiving part 4 form mounting table 40 opening 5 elevating screw shaft 6 handle 7 pressure end member 8 form 9 mold

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B22D 29/00 A61C 13/20 B22D 23/00

Claims (3)

(57) [Scope of request for utility model registration] 1. An apparatus for extracting a mold after precision casting from a short tubular mold filled with the mold, wherein an opening is provided on the base with a space below and through which the mold can pass. A form-mounting table, a screw receiving portion provided on an upper portion of a support standing on the base, a lifting screw shaft screwed into the screw receiving portion to move up and down the opening, and a lifting screw shaft And a pressure end member pivotally attached to the lower end of the elevating screw shaft and having a surface for pressing the upper surface of the mold on the form-mounting table. The screw receiving portion includes a guide surface that supports the lifting screw shaft vertically slidably in an inner space where the lifting screw shaft is loosely fitted,
On the opposite side of the space of the guide surface, a meshing part having a thread groove formed on the lower end side to be screwed with the thread on the outer periphery of the elevating screw shaft,
An operating lever that supports the horizontal axis of the side wall of the cavity and elastically urges the screw shaft side by a compression spring, and that the upper end side of the meshing piece protruding from the cavity is an operation lever for releasing meshing. A form removing device. 2. The method according to claim 1, wherein a pair of columns are provided on both sides of the base, and the form-mounting table is formed as a thick plate and is detachably mounted between the columns. 3. The form extraction device according to 1. 3. The form extracting device according to claim 1, wherein a grip portion is formed on the column to be a portable type.