JPS6340619B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sprue forming apparatus for a vacuum molding mold, which molds a sprue having a sprue at the upper end into which molten metal is poured into the vacuum molding mold.

Conventionally, in order to mold a sprue and a socket at the same time when creating a vacuum molding mold, a sprue rod with a trapezoidal or other shaped socket model with a small lower side integrally provided at the upper end was used as a vacuum molding mold. It is set up in a removable manner at a predetermined location on the model board, and then a synthetic resin film is tightly attached to the surface of the model board, including the sprue rod, and then a mold for vacuum molding is fitted onto the model board. The space formed by the model plate and the flask is filled with a filler material, and another shielding film is placed over the upper surfaces of the flask and the filler material.Then, the pressure inside the flask is reduced to solidify the filler material. After that, the film just above the socket of the sprue rod is cut off and the sprue rod is pulled out upwards to form the mold. However, this method requires steps such as attaching and detaching the sprue rod to and from the model plate and cutting out the film. It requires special equipment to be used, which has disadvantages such as poor productivity and the vacuum molding equipment is complicated and expensive.

The present invention was completed with the aim of providing a sprue forming apparatus for a vacuum molding mold that does not have the above-mentioned drawbacks.
The illustrated embodiment will be described in detail below.

Reference numeral 1 denotes a horizontal lifting table which can be raised and lowered via a guide rod 4 by an upward cylinder 3 and two guide cylinders 4' fixed to a base frame 2;
A vibration table 6 equipped with an oscillation device 5 is elastically supported on the lifting table 1 by a plurality of air springs 7, and a vertical bearing 8 is erected on the base frame 2 on the side of the lifting table 1. A central shaft 10 of a rotary table 9, which is kept horizontal, is supported, and a support base 11 is provided with rollers 12 rotatably mounted on the upper end at appropriate intervals around a vertical bearing 8. An appropriate number of rollers are arranged, each roller 1
The roller surface of No. 2 is in contact with the lower surface of the rotary table 9, and the rotary table 9 is supported by each roller 12 and can be rotated intermittently in a horizontal plane by a drive device (not shown). The lower surface level is above the upper surface level of the vibration table 6 during descent, and the rotary table 9
A plurality of openings (not shown) through which the lifting table 1 and the vibration table 6 can pass are formed at equal pitches around the periphery. Reference numeral 13 designates a model plate having a model 14 on its surface and a cylindrical sprue rod 15 having no socket model at the upper end, erected in the runner section to the model 14, and one parallel side of the model plate 13. Hooking members 16 are protruded at intervals on the outside of the surface, and holes 17 formed in the hooking members 16 are formed on opposite sides of the opening of the rotary table 9 at similar intervals. By engaging with the guide pins 19 of the respective brackets 18, the model plate 13 is supported by the opening of the rotary table 9 and can be moved in and out of the position directly above the vibration table 6 in the lowered position by the intermittent rotation of the rotary table 9. The model board 13 has a structure in which it can be raised and lowered freely by an elevator table 1 as described later, and a decompression chamber 20 is formed inside the model plate 13, and a vacuum source (not shown) and a flexible The vacuum chamber 20 and the surface side of the model plate 13 are communicated with each other through a conduit 20', and the vacuum chamber 20 and the surface side of the model plate 13 are communicated with each other through a large number of suction holes 20''. A film 21 is applied to the surface of the plate 13 including the model 14, sprue rod 15, etc. via a film spreading device (not shown).
is becoming more and more closely followed. Further, a roller conveyor 22 is horizontally disposed directly above the vibration table 6 and slightly above the rotary table 9, and a large number of flanged rollers are mounted on the opposing inner surfaces of a pair of frames of the roller conveyor 22. 23 are pivotally supported at a required interval so that they can pass through the model plate 13 and the vibration table 6, and these flanged rollers 23
A molding flask 24 for vacuum molding is placed on top and is intermittently moved by a conveying means (not shown) so that it can be stopped directly above the vibration table 6, and this flask 24 is provided with a vacuum source (not shown) on the side. A decompression chamber 25 communicating with the decompression chamber 25 is formed, and an appropriate number of vent pipes 26 communicating with the decompression chamber 25 are disposed inside. Reference numeral 27 is a downward-facing shaft whose both sides are pivotably supported by links 29, 29 which are swingably provided on a fixed frame 28 that stands on the side of the vibration table 6, and whose upper surface is swingably attached to the fixed frame 28. This is a swinging frame that is swingably connected to the tip of the piston rod 31 of the cylinder 30 and moves diagonally up and down as the piston rod moves up and down. It consists of a pair of guide rails 32 formed, the tip side of which is positioned above the casting flask 24 that is carried in to a position directly above the model plate 13 placed on the vibration table 6, and between the two guide rails 32. is a space large enough to allow the casting flask 24 and the like to pass through, and a film transport frame 33 is held between the guide rails 32 via a plurality of wheels 34 provided on both sides of the film transport frame. 33 is a motor 3 with a reducer installed at the rear end of the guide rail 32
5 and a conventional means such as a roller chain, the flask 24 is moved along the guide rail 32 as described later to the forward position on the flask 24 which is aligned with the model plate 13 and filled with a filler F such as molding sand. It is freely movable back and forth between a retracted position located outwardly from the top of the flask 24. Further, the conveyance frame 33 has a hollow chamber 36 on its peripheral wall that communicates with a vacuum source (not shown), and a groove that allows communication with the hollow chamber 36 on the lower surface of the hollow chamber 36 as shown in FIG. 37 is formed to hold an air-permeable sealing member therein, and is configured to be able to adsorb and hold a film 38 attached to the upper surface side of the filler F filled in the flask 24. Reference numeral 39 denotes a hopper for the filler F, which is installed above the model plate 13 located directly above the vibration table 6 and above the transport frame 33 which is in the forward position. 1
A gate device 40 is provided for supplying and stopping the filler F into the flask 24 combined with the casting flask 3, and the gate device 40 is connected to the pair of molds combined vertically so as to form a space 41 in the middle. Holding plate 4
2 is fixed to the bottom opening of the hopper 39, and the filler F is fixed to the same position on the holding plates 42, 42, respectively.
A suitable number of supply holes 43 are provided therethrough, and a gate plate 45 having communication holes 44 of the same pitch as the supply holes 43 is slidably inserted into the space 41 so as to protrude from the holding plate 42. The end of the gate plate 45 is connected to a piston rod 48 of a cylinder 47 supported by a hopper 39 via a bracket 46. Further, at the lower part of the hopper 39, in a portion corresponding to the position of the sprue rod 15 erected on a predetermined model plate 13 located below the hopper 39, there is an independent compartment partitioned off by a partition wall 49. 50, a support plate 51 is stretched on the bottom of the compartment 50, and the support plate 51
An opening 52 is formed in a portion of the gate device 40 corresponding to the lower part, and a downward cylinder 53 located in the compartment 50 is attached to the support plate 51 so as to be substantially concentric with the center of the sprue rod 15. There is,
The piston rod 54 protrudes toward the opening 52 and has a socket model 55 formed in a desired socket shape at its lower end, which is movable up and down. It is formed by a disk-shaped upper wall member 56 fixed to the lower end, and its lower part is fixed to the lower end of a conduit 57 whose upper end is fixed to the back surface of the upper wall member 56, and is concentric with the upper wall member 56 at intervals. Sprue rod 1 suspended from
A side wall formed by a bottom wall member 58 having a diameter larger than 5, and having a side wall wrapped with a wire mesh or the like having a mesh such that the filler F cannot pass between the circumferential surfaces of the upper wall member 56 and the bottom wall member 58. The inside formed by the member 59 has a structure in which a hollow part 60 has ventilation, and the hollow part 60 of the socket model 55 surrounded by the side wall member 59 has a ventilation hole 61 and It communicates with the atmosphere through a filter member 62, and furthermore, a cushion member 63 made of rubber or other elastic material and having approximately the same dimensions as the bottom wall member 58 is fixed to the lower end surface of the bottom wall member 58. The sprue rod 15 of the predetermined model plate 13 that is lowered and positioned below the hopper 39 can come into contact with the upper end surface of the sprue rod 15 in a pressed state, so that the sprue rod 15 and the socket model 55 are connected. The upper wall member 56 and the bottom wall member 5
8. The cushion member 63 is provided with an air supply hole 64 and an exhaust hole 65 that communicate with the conduit 57, one end of the air supply pipe 66 is connected to the inlet side of the air supply hole 64, and the other end of the air supply pipe 66 is connected to the inlet side of the air supply hole 64. The opening 52 faces into the compartment 50 and communicates with a source of compressed air via a flexible conduit 66' and an on-off valve (not shown). 67 is a cover member 6 attached to the transport frame 33.
As shown in FIG.
The film 38 is disposed on the conveying frame 33 so as to appropriately heat a portion of the film 38 which is attached to the upper surface of the film 38 and corresponds to the socket S formed by the socket model 55.

As shown in FIG. 1, with this structure, the decompression chamber 20 of the model plate 13 held in the opening of the rotary table 9 is moved when the socket model 55 is in the raised position by the cylinder 53. After reducing the pressure through the flexible conduit 20' by a vacuum source (not shown), the film 21, which has been softened by heating to an appropriate temperature, is suctioned through the suction pores 20'' to contain the model 14 and the sprue rod 15. The model plate 13 is brought into close contact with the surface, and then the rotary table 9
is intermittently rotated to transport the model plate 13 to a position directly above the vibration table 6 in the lowered position, and then the cylinder 3 is actuated to raise the vibration table 6 together with the lifting table 1, and the vibration table 6 rotates. On the way through the opening of the table 9, the model plate 13, which had been positioned and held on the rotary table 9 by the bracket 18 and the guide pin 19 via the hooking member 16 and the hole 17, is received and placed on the vibration table 6. The flask 24 is brought into a standby position directly above the vibrating table 6 by the flanged roller 23 of the roller conveyor 22 and is on standby.
As the mold plate 13 rises, it passes between the flanged rollers 23 and is received by the rising model plate 13 and assembled, thereby aligning the frames. From then on, the vibration table 6, the model plate 13, and the flask 24 rise as a set. When the upper surface of the flask 24 comes into contact with the lower surface of the gate device 40 at the bottom of the hopper 39 and is tightly pressed, the entire ascent stops. Subsequently, the socket model 55 at the end of the piston rod 54F is lowered by the operation of the cylinder 53, and the lower surface of the cushion member 63 on its lower end surface is pressed and connected to the upper end surface of the sprue rod 15 to which the film 21 is tightly attached. The cylinder 47 is operated and the piston rod 48 moves the gate plate 45 to connect the communication hole 44 to the supply hole 4 of the holding plate 42.
3, the gate device 40 is opened and the filler F in the hopper 39 is supplied into the space formed by the flask 24 and the model plate 13. When the supply is finished, the cylinder 47 is operated in reverse to close the gate. The plate 45 is returned to its original position, the communication between the supply hole 43 and the communication hole 44 is cut off, and the gate device 40 is closed. Next, the oscillator 5 is operated for a required period of time to vibrate the model plate 13, etc., thereby filling every corner of the flask 24, the model 14, etc. with the filler F, while the cylinder 3 is operated in reverse to vibrate the model plate 13, etc. , the model plate 13, etc. are lowered together and stopped just before the lower surface of the flask 24 is placed on the flanged roller 23 of the roller conveyor 22, as shown in FIG.
In order to maintain the connection between the cushion member 63 and the sprue rod 15, the cylinder 53 is operated to lower the piston rod 54 to follow the lowering of the model plate 13, and the socket model 55 is lowered in the same manner as the model plate 13. let Next, when the pressure reduction chamber 25 of the flask 24 is communicated with a vacuum source (not shown) and the pressure inside the flask 24 is reduced through the air vent pipe 26, the upper surface of the filler F filled in the flask 24 is exposed to the socket model 55. The part other than the part where is located is in direct contact with the atmosphere, and the socket model 55
The part that contacts the air-permeable side wall member 59 is connected to the hollow part 60 through the filter member 62 and the ventilation hole 61.
Since it is in communication with the atmosphere, it is also in contact with the atmosphere, and the filling material F is stabilized in a uniform semi-solid state in the flask 24 by the depressurization effect via the vent pipe 26. Thereafter, an on-off valve (not shown) is opened to supply compressed air from the compressed air source to the flexible conduit 66', the air supply pipe 66, the air supply hole 64 and the conduit 57.
The sprue rod 15 is ejected from the lower end of the exhaust hole 65 through
When the film 21 located on the upper end surface is pressed against the upper end surface and the cylinder 53 is reversely operated to raise the socket model 55 and separate it from the upper end surface of the sprue rod 15, the side wall member 59 of the socket model 55 is removed. As mentioned above, the part of the filler F that is in contact with the air is in contact with the atmosphere and is in a stable state of semi-solidification, so it is easily released from the mold by raising the socket model 55, thereby preventing mold deformation, etc. A concave socket S corresponding to the socket model 55 is molded quickly and accurately on the sprue rod 15 without any formation, and compressed air is blown out from the lower end of the exhaust hole 65 when the mold is released. Even if a part of the filler F is present on the film 21 on the upper end surface, it is blown away and cleaned, so that the filler F does not get mixed in during pouring, and defects such as sand deposits do not occur. In this way, after releasing the socket model 55 and returning it to its original position and stopping the blowout of compressed air from the exhaust hole 65, the swing frame 2
The transfer frame 33, which is held in the retracted position on the guide rail 32 of No. 7 and is waiting with the film 38 adsorbed to the groove 37 on the lower surface of the hollow chamber 36, is advanced onto the casting flask 24 by rotating the motor 35; Next, the cylinder 3 is heated while the heater 67 is activated to heat the portion of the film 38 corresponding to the socket S.
When the piston rod 31 is lowered by the operation of 0, the guide rail 32 is moved obliquely downward by the action of the links 29, 29, and the conveying frame 33 is placed on the casting flask 24 as shown in FIG. In this state, when the vacuum in the hollow chamber 36 is stopped and the suction and holding of the film 38 by the groove 37 is released, the film 38
is suctioned and brought into close contact with the upper surface of the filler F where the suction action is working, and in this case, the portion of the film 38 corresponding to the socket S is heated and softened by the heater 67 and curved as shown by the chain line in FIG. Because of its shape, it can be easily and reliably brought into close contact with the surface of the socket S formed in the shape of a concave portion, and can also be brought into close contact with the surface of the film 21 on the upper end surface of the sprue rod 15 without the interposition of a filler F or the like. As a result, the filler F
The upper and lower surfaces are respectively film 38 and 21.
It is sealed and completely solidified with the socket S formed on the sprue rod 15 by the decompression action by the decompression chamber 25 of the flask 24, the vent pipe 26, etc. Next, the cylinder 30 is reversely operated to move the guide rail 32 diagonally upward, and the motor 35 is reversely rotated to return the transport frame 33 to its original position. The film 21 is brought into close contact with the lower surface of the filler F, which is in a reduced pressure state, by cutting off the communication with the model plate 13 and releasing the film 21 from the model plate 13. In this state, the cylinder 3 is operated in reverse. When the lifting table 1 is lowered, the vibrating table 6, model plate 13, and flask 24 are also lowered together, and on the way, the lower surface of the flask 24 is placed on the flanged roller 23 of the roller conveyor 22 and held there. The model plate 13, which continues to descend, is solidified under reduced pressure and filled with the filler F held in the flask 24.
The film 2 is then cut out, and a socket S is placed at the upper end of the sprue hole formed by the sprue rod 15.
1, 38 are formed in communication via a polymerization part, and
The molding of the vacuum molding mold having the mold cavity using the model 14 is completed. Next, at the opening of the rotary table 9, the model plate 13 is positioned and held on the rotary table 9 by the engagement of the retaining member 16 and the hole 17 with the bracket 18 and the guide pin 19 of the rotary table 9, and is further moved up and down. The table 1 and the vibration table 6 are lowered and returned to their original positions. On the other hand, the flask 24 with a built-in vacuum mold mold held by the roller conveyor 22 is transported to a predetermined position by an appropriate conveyance means, and another empty mold 24 is transported to a position directly above the vibration table 6, and The model plate 13 on which the new film 21 has been suctioned and adhered is carried by the rotation of the rotary table 9 to a position directly above the vibration table 6 below the casting flask 24, and
The film 38 is again adsorbed and held in the groove 37, and the above-mentioned operation is repeated, and the molding of the vacuum molding mold having the sprue with a socket is continued. Although the upper wall member 56 and the bottom wall member 58 are circular in the above embodiment, they are not limited to this and may be determined as appropriate according to the shape of the upper end surface of the sprue rod 15. Therefore, the shape of the socket model 55 is determined accordingly, and the heater 67 is connected to the film 3.
It may be omitted depending on the extensibility of the sprue 8 or the form of the sprue rod 15. Furthermore, if the socket model 55 is made of a material that has air permeability, it is not necessary to have a hollow interior.

In the present invention, a downward-facing cylinder is installed in a compartment provided in a filler hopper in a vacuum forming mold making device, and the lower end of the piston rod is connected to a sprue rod erected on a model plate by descending. By providing a breathable socket model, it is possible to easily mass-produce vacuum molding molds having a sprue with a socket, and it has industrial value as it eliminates the drawbacks of conventional equipment. It is extremely large.

[Brief explanation of the drawing]

The drawings show an embodiment of the sprue forming apparatus for a vacuum molding mold according to the present invention, and FIG. 1 is a partially cutaway front view showing the sprue molding device in use with the spout model in the raised position, and FIG. A partially cutaway front view showing the socket model connected to the sprue rod in the flask that has been filled and lowered, and Figure 3 is a partially cutaway view showing the state where a film is attached to the top surface of the filler material including the socket. It is a notch front view. 13: Model board, 15: Sprue rod, 39: Hotsupa,
40: Gate device, 49: Partition wall, 50: Compartment, 53: Cylinder, 54: Piston rod, 5
5: Socket model with ventilation.

Claims (1)

[Claims] 1. A hopper 39 equipped with a gate device 40 is installed above the model plate 13 for vacuum molding which can be raised and lowered, and inside the hopper 39 there is a portion corresponding to the sprue rod 15 erected on the model plate 13. A compartment 50 partitioned by a partition wall 49 is provided, and a downward cylinder 53 is installed in the compartment 50 and is approximately concentric with the center of the sprue rod 15. A spout model 55 having air permeability is connected to the sprue rod 15 by
A sprue forming device for a vacuum molding mold, characterized in that it is provided with a sprue forming device.