JPS6048257B2 - mold making machine - Google Patents

Description

Detailed Description of the Invention This invention is a mold making machine that blows compressed air into molding sand blown into upper and lower mold flasks, and then pressurizes the mold sand in the flasks with compression plates to create a mold. Regarding.

In recent years, various blow squeeze molding methods have been developed in which molding sand and compressed air are simultaneously blown into a casting flask, and then the blown molding sand is pressurized to obtain hardness of the mold. However, with this method, the shaded part of the model (on the opposite side to the direction in which the molding sand is blown) becomes an air pocket, and the molding sand does not fully reach this part, resulting in insufficient sand clogging, making it difficult to produce a good mold with uniform density. Especially when using a mold with a complex shape with severe ups and downs, the compressive force cannot be transmitted to every corner of the flask by blow squeeze alone, and sufficient hardness cannot be obtained in deep recesses. It was hot. In view of the above, this invention
It is an object of the present invention to provide a mold making machine capable of making good molds with uniform density and sufficient hardness. The structure of the present invention will be explained below based on the embodiment shown in the drawings.

Reference numeral 1 denotes a gate-shaped frame, which is composed of columns 3 that stand upright on a lower frame 2 to face each other, and an upper frame 4 that connects the upper ends of the columns 3.

An intermediate frame 5 is provided slightly near the lower end of the gate-shaped frame 1. The intermediate frame 5 is fixed in a state spanning between the left and right columns 3. A squeeze cylinder 6 is attached to the intermediate frame 5 facing upward, and a lower compression plate 9 is fixed to the tip of the piston rod 7, which has a large number of small-diameter ventilation holes 8 formed on the upper surface for venting compressed air. A conveyor 10 is guided to the left of the lower compression plate 9, and the upper surface of this conveyor 10 is at the same height as the upper surface of the lower compression plate 9 at the lower end. Furthermore, a lower frame 11 having a size that allows the lower compression plate 9 to pass through is arranged above the lower compression plate 9 at the lower end. Both outer walls of the lower frame 11 are fixed to the tip of a J piston rod of a mold matching cylinder (not shown), and are installed so as to be movable up and down between the upper surface of the compression plate 9 at the lower end and the upper overlapping position. The lower frame 11 has a hollow part 12 formed from its inner and outer walls, and the hollow part 12
A suitable number of ventilation holes 13 opened in the inner wall are communicated with each other, and a shutoff valve 15 is connected through a rubber hose 14 so as to be able to communicate with the atmosphere. Furthermore, a molding sand blowing port 16 is formed at a predetermined position on the inner wall of the lower frame 11 to allow the molding sand to pass through to the outside. An extrusion cylinder 18 having a mold extrusion plate 17 fixed to the tip of a piston rod 19 is installed on the opposite side of the conveyor 10 described above.
8. When retracted, there is a slight gap between it and the lower frame 11, and it is movable horizontally by the extrusion cylinder 18. Above the lower frame 11, a match plate 23, which is a hollow 20-shaped box, is placed on a flanged roller 24 so as to be horizontally movable between a molding position and a standby position at the rear.

Appropriately small-diameter discharge holes 21 are formed on the upper and lower surfaces of the match plate 23. In both cases, there is a model 2 approximately in the center.
2 is installed. An exhaust hole (not shown) communicating with the hollow portion 20 is provided in the side wall of the match plate 23 . Further, above the match plate 23, an upper frame 25 is arranged opposite to the lower frame 11, and this upper frame 25: is the column 3.
It is fixedly supported by a support member 26 that is fitted into the support member 26. The upper frame 25 has a hollow part 27 formed from the inner and outer walls, and an appropriate number of small i-diameter ventilation holes 28 communicating with the hollow part 27 are formed in the inner wall, and a casting of the plowing head 30 is formed at a predetermined position. Sand blowing row, blowing port 32 that can communicate with I3l
is formed. ! Further, an input valve 29 is connected to the upper part of the hollow part 27 so as to be able to communicate with the outside air. Further, above the upper frame 25, an upper compression plate 34 is installed which can pass through the inside of the upper frame 25 and has a small-diameter ventilation hole 33 for compressed air formed in its lower surface.

The upper compression plate 34 is fixed to the tip of the piston rod 35 of a squeeze cylinder 36, and the squeeze cylinder 36 is fixed to the upper frame 4 in a downward direction. Furthermore, a plowing head 30 equipped with blow-off ports 31 and 37 for molding sand is installed on the upper right side of the gate-shaped frame 1.

Each of the blow-off ports 31 and 37 can communicate with blow-in ports 32 and 16 formed in the side walls of the upper and lower frames 25 and 11, respectively. A molding sand supply port 30a is formed in the upper part of the plowing head 30 and is equipped with an on-off valve 38 that can be opened and closed by an on-off cylinder (not shown). Further, at a predetermined position on the side wall of the plowing head 30, there is a shut-off valve 39 that can communicate with the outside air.
An exhaust valve 40 and a two-way switching valve 4 are located on the opposite side of the cut valve 39.
3 is connected. One end of the two-way switching valve 43 is the pipe 41
, 42 to each frame 11, 25, and the other end can communicate with the atmosphere. Further, 44 is a pressure reducing valve installed in the piping 42, and compressed air with a pressure slightly lower than or almost equal to that of the compressed air supplied into the blowing head 30 is supplied to each frame 11, 25 from the ventilation holes 8, 33. can be supplied to

45 is foundry sand.

Note that a partition plate may be arranged horizontally within the hollow portion 20 to prevent mutual interference between compressed air blown in from above and below. Next, the mode of use of this invention will be explained.

The lower frame 11 is raised by the operation of a mold matching sill (not shown), and the mold is matched to the match plate 23 set at the molding position.Then, the matched lower frame 11 and the match plate 23 are raised as a unit. , superimposed on the upper frame 25. At this time, the blowing ports 16 and 32 of each frame 11 and 25 are in communication with the molding sand supply ports 37 and 31 of the plowing head 30. At this point, the lower squeeze cylinder 6 is actuated to raise the lower compression plate 9 to the lower end of the lower frame 11 with which the molds have been matched and close the lower end open surface of the lower frame 11, and at the same time, the upper end open surface of the upper frame 25 is pressed into place by the squeeze cylinder. 36, the upper compression plate 3
4 is blocked. Thereafter, the on-off valve 38 and the exhaust valve 40 are closed, the two-way switching valve 43 is communicated with the atmosphere, and the cut valves 15 and 29 are opened to place the frames 11 and 25 in communication with the atmosphere. Furthermore, the cut valve 39 communicating with the compressed air source is opened to supply compressed air into the plowing head 30, and the molding sand 45 inside is discharged from the blow-off ports 37, 31 through the blow-in ports 16, 32 to the respective frames 11, 25. Blow it inside. Here, the compressed air blown into the frames 11, 25 together with the molding sand 45 passes through the ventilation holes 13, 28 and from the cut valves 15, 29 which are in communication with the atmosphere, and also through the compression plates 9, 34. The gas is discharged to the outside through the air holes 8 and 33 from the two-way switching valve 43 which is in communication with the atmosphere, or from an exhaust hole (not shown) formed in the match plate 23, respectively. After blowing the molding sand into the frames 11 and 25 in this way, the cut valve 1
At the same time, the two-way switching valve 43 is communicated with the plowing head 30, and the compressed air supplied into the plowing head 30 via the cut valve 39 is transferred to the two-way switching valve 43, the piping 41, 42 and ventilation holes 8 and 33 into the frames 11 and 25, respectively, to increase the filling hardness of the molding sand near the match plate. The compressed air supplied into the frames 11, 25 passes through the molding sand, is led into the match plate 23 through the exhaust hole 2.1, and is then exhausted to the outside through the exhaust hole (not shown) on the side thereof. . At this time, the compressed air supplied into the frames 11 and 25 has a slightly lower pressure at the pressure reducing valve 44 than the compressed air supplied into the plowing head 30, so it flows back into the plowing head 30. Compressed air is reliably communicated through the molding sand without causing any damage. The model 2 has an exhaust hole (not shown) that communicates with the match plate 23 surface or with the match plate 23.
2. There is a method that can harden the foundry sand on the surface. After the compressed air is passed through the molding sand in the frames 11 and 25 in this way to increase the filling hardness of the molding sand near the match plate, the cut valve 39 is closed and the two-way switching valve 43 is communicated with the atmosphere. , and the exhaust valve 40 is opened once to exhaust the compressed air accumulated in the plowing head 30.

Next, the squeeze cylinders 6, 36 are operated again, and the molding sand filled in the frames 11, 25 is pressurized by the compression plates 9, 34, thereby increasing the filling hardness of the molding sand near the compression plates 9, 34. Here, the pressing force of the squeeze cylinders 6 and 36 is
Foundry sand filling hardness near match plate 23 and compression plate 9,
Needless to say, the hardness is set to be equal to the foundry sand filling hardness around 34. Therefore, it is possible to mold a mold having good uniform hardness as a whole. Next, each squeeze cylinder 6, 36 is retracted to separate the compression plates 9, 34 from the casting surface, and the mold setting cylinder (not shown)
is retracted to lower the lower frame 11.

Here, the match plate 23 is placed on the flanged roller 24 at a predetermined position, and only the lower frame 11 moves to the lower end. On the other hand, after the lower frame 11 has been lowered, the match plate 23 is moved from the molding position to the rear waiting position by a drive device (not shown). At this point, the mold setting cylinder (not shown) is operated again to raise the lower frame 11 holding the lower mold,
The frame is aligned with the upper mold of the upper frame 25. Next, the squeeze cylinder 6 is operated to lift the lower compression plate 9 and bring it into close contact with the lower surface of the lower mold in the lower frame 11. Then, the upper compression plate 34 is lowered by the operation of the upper squeeze sill 36, and the frame 1 is lowered.
1 and 25, the upper and lower molds are pushed out, and the squeeze cylinder 6 is again retracted to move the upper and lower molds to the lower end while being placed and held on the lower compression plate 9. At this time, the lower end surface of the mold is located at the same height as the upper surface of the conveyor 10. After performing the die cutting operation in this way, the extrusion cylinder 1
8, the pair of completed molds on the lower compression plate 9 are pushed out onto the conveyor 10, completing one step of the molding work.
Furthermore, the foundry sand 45 stored in the plowing head 30
After closing the cut valve 39 to cut off the supply of compressed air, the on-off valve 38 is opened and the air is supplied from the supply port 30a. Furthermore, when releasing the formed mold from the Munch plate 23, if compressed air is supplied to the surface side of the match plate 23 from the exhaust hole 21 formed in the match plate 23, the mold and model plate can be easily released. can do. Since the present invention has the above-mentioned configuration, it has excellent effects such as being able to fully fill the shaded part of the model with molding sand and making a mold with good uniform hardness, and also making it possible to make a mold for a model having a complicated shape. .

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention. 8, 33...Vent hole, 9...Lower compression plate, 11...Lower frame, 16,32...
Inlet, 21...Discharge hole, 23...Match plate, 25...Upper frame, 34...
- Upper compression plate.

Claims (1)

[Scope of Claims] 1. A casting flask equipped with a molding sand blowing port on a side wall; a compression plate that is equipped with a ventilation hole for blowing compressed air into the flask and that can be fitted into the flask; a model plate that is provided with an exhaust hole for exhausting air from inside the flask, faces the compression plate across the flask, and is movable relative to the flask in order to be combined with the flask; a mold making machine comprising: a blowing head equipped with a foundry sand outlet that can communicate with the foundry sand outlet of the flask; 2 a first flask equipped with a molding sand inlet on a side wall;
Equipped with ventilation holes to blow out compressed air into the flask,
a first compression plate that can be fitted into the first flask; a second flask provided with a molding sand blowing port on a side wall and disposed opposite to the first flask; a second compression plate that can be fitted into the second flask and has a ventilation hole for blowing out compressed air into the flask; an exhaust hole for exhausting air from inside the first and second flask; a match plate having on both sides thereof; a mold matching cylinder that moves one or both of the flasks in order to sandwich the match plate between the first and second flasks and mold them; A mold making machine comprising a blowing head having a foundry sand outlet that can communicate with each foundry sand outlet of the first and second flasks.