JPS6021810B2 - Frameless mold and its manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flaskless mold for casting and an apparatus for manufacturing the flaskless mold.

Generally, casting molds consist of a pair of upper and lower molds that are formed by compacting molding sand to form a cavity for molding the product, but molds used for casting relatively small items are designed to prevent their shape from collapsing. Frameless molds, which simply consist of sand molds and do not require a frame to firmly hold each mold as a whole, have recently come into widespread use.

According to such a flaskless mold, there is no need for molds that correspond to or exceed the number of molds flowing on the casting line, so the equipment cost and maintenance management for it are reduced. It is characterized by eliminating costs, and the structure of the molding machine itself is simplified and inexpensive, resulting in lower manufacturing costs for cast products.
If the coin weight is relatively large, there is a possibility that the mold will be destroyed by the pressure of the molten metal acting toward the sides of the mold. Therefore, the entire side surface of the matched mold is formed into a continuous tapered surface shape that expands downward, and in the western hot water process, a cover frame having an inner circumferential surface that matches the tapered surface shape is attached to the upper and lower molds. A method has been proposed in which the destruction of the mold is prevented by reinforcing the mold with a covering frame, but this conventional method also had the following drawbacks. Since the sand mold and the formwork are in contact only at the tapered surfaces, the frictional force between them is insufficient and the sand mold and formwork contact each other only at the tapered surfaces, so that the sand mold and the formwork contact each other only at the tapered surfaces, so the frictional force between them is insufficient. The sand mold may come off from the formwork due to vibration or impact, etc.
Particularly in the case of an upper mold, the mold release force that is applied during mold release promotes the peeling action between the inner peripheral surface of the mold and the sand mold, aggravating the above-mentioned defects. The squeeze plate for compaction is inserted into the formwork from the back of the formwork, but since the inner circumferential surface of the formwork is uniformly tapered, it is difficult to use when filling with molding sand and compaction. The state of contact between the squeeze plate and the inner circumferential surface of the formwork changes at each orientation from when it is finished, making it difficult to set the optimal contact conditions for molding, and once the conditions are set. It is no longer possible to create molds with optimal heights depending on the size of the casting product, and when sending the cut and matched molds from the molding machine to the next process, extrusion using pressure cylinders etc. is no longer possible. However, since the entire side surface of the mold has a narrow shape, the direction of action of the extruder is not perpendicular to the side surface of the mold, which causes undesirable external force to act on the mold. However, this is also a factor that causes the product to lose its shape.

The present invention eliminates the above-mentioned drawbacks by making only the side surface near the mold-fitting surface of the mold, which requires reinforcement by a cover frame, into a tapered shape, and the other parts being parallel surfaces perpendicular to the mold-fitting surface. The purpose of this invention is to provide a possible frameless mold and an apparatus for manufacturing the frameless mold.

The present invention will be explained in detail below based on the illustrated embodiments. First, one embodiment of a mold making machine for embodying the present invention will be described with reference to FIG. A rotary table 3 is attached which can repeatedly rotate intermittently by an appropriate angle about the axis of the rotary table 3, and the tip of a shaft 4 of the rotary table 3 is supported by a frame 5.

However, it is also possible to omit support at this portion and provide cantilever support only at the lower portion.

The rotary table 3 has guide rails 6, 6 symmetrically with respect to the rotation axis of the rotary table 3 and at an inclination angle of 450 with respect to the axis.
' is fixed. Although the guide rails 6 and 6' are not shown in the drawing, they are composed of a pair of cylindrical guide rods 6, 6, 6', and 6' arranged in parallel and spaced apart from each other by an appropriate distance. . Upper and lower formworks 7, 8, 7', 8' are slidably supported on the guide rails 6, 6', respectively, and the upper and lower formworks 7, 8, 7', 8' are equipped with pressure cylinders (not shown), etc. They can be brought close to and separated from each other depending on their action. Here, the side including the upper and lower formworks 7 and 8 is called a first formwork equipment 9, and the side including the upper and lower formworks 7' and 8' is called a second formwork device 10, and the guide rod 6 is horizontal as shown in the figure. When the shape is reached (the common koji core of the upper and lower formworks 7 and 8 also becomes horizontal), the guide rod 6'
is vertical (the common axis of the upper and lower formworks 7', 8' is also vertical), but in this case, the place where the first formwork counterfeit 9 is located is the molding station 11, and the second The locations where the formwork device 10 is located will be respectively referred to as a frame punching station 12. The molding station 11 has squeeze plates 13 and 14 that can be inserted with iron into the upper and lower formworks 7, 8, 7', and 8' from the backs of the upper and lower formworks 7, 8, 7', and 8', respectively. Squeezing devices 15 and 16 are disposed facing each other, a match plate 18 is attached to the frame via a frame body 17, etc., and a molding sand supply device 19 that is movable up and down is disposed. ing. Note that an expandable sprue model 20 is attached to the squeeze plate 13 on the upper formwork 7, 7' side. On the other hand, in the frame punching station 12, it is possible to contact the lower end surface of the lower molds 8, 8' downwardly, or it can be inserted into the lower molds 8, 8' and directly contact the lower surface of the lower mold. A mold receiving device 22 having a mold receiving plate 21 is disposed above, and the upper mold frame 7, 7' is filled with iron so that it comes into contact with the upper surface of the upper mold and can press the mold downward. A pressing device 24 having a pressing plate 23 is provided. Second
Squeeze plates 13, 14 and upper and lower formwork 7 based on the diagram
, 8, 7', 8' in more detail, the upper formwork 7, 7'
The inner circumferential surface of is formed on the back side where the squeeze plate 13 is inserted, and is parallel to the common axis of the upper and lower formworks 7, 8, 7', 8' (
a parallel surface 26 that is perpendicular to the front end surface 25 that contacts the match plate 18; and a parallel surface 26 that is continuous with the parallel surface 26 and is
The inner peripheral surfaces of the lower formworks 8, 8' are formed on the back side where the squeeze plate 14 is inserted, and the upper and lower formworks 7, 8, 7', 8' A parallel surface 29 parallel to the common axis of the match plate 18 (perpendicular to the front end surface 28 in contact with the match plate 18), and a tapered surface 30 continuous with the parallel surface 29 and tapered toward the front end surface 28. ing.

Note that the inner peripheral edges of the front end surfaces 25, 28 of the upper and lower formworks 7, 8, 7', and 8' are shaped to perfectly align with the direction of the ball of the upper and lower formworks 7, 8, 7', and 8'. In addition, the tapered surfaces 27 and 30 have the same bevel angle, and are provided over a range sufficient to substantially surround the model portion of the match plate 18 during molding. Further, the parallel surfaces 26 and 29 are set to a size such that a portion substantially in contact with the molding sand remains even after the molding sand is compacted. 31 and 32 are upper and lower formworks 7 and 8.7', respectively.
, 8' is a molding sand supply entrance that is drilled into the side wall of the molding sand.

A sealing material 33 is attached to the outer circumferential surfaces of the squeeze plates 13, 14 to achieve sealing with the inner circumferential surfaces (parallel surfaces 26, 29) of the upper and lower formworks 7, 8, 7', 8'. ing. In FIGS. 3 and 4, numerals 34 and 35 indicate upper and lower molds that have been molded, punched, and matched at a mold matching surface 36, and a product molding cavity 37 is formed inside the molds.

Continuous downwardly expanding tapered surfaces 38 and 39 are formed on the outer peripheral surfaces of the upper and lower molds 34 and 35 in the vicinity of the mold matching surface 36, and the remaining surfaces are parallel surfaces 40 and 41 perpendicular to the mold matching surface 36. . 42 is a transport table for transporting the upper and lower molds 34, 35 on the mold receiving plate 21 to the next process (pouring process);
Reference numeral 3 denotes an extrusion device consisting of a pressure cylinder or the like for sending the upper and lower molds 34, 35 on the mold receiving plate 21 onto the conveyor table 42. Further, 44 is a cover frame which has an inner circumferential surface having the same tapered shape as the tapered surfaces 38 and 39 of the upper and lower molds 34 and 35 and can be brought into close contact with the tapered surfaces 38 and 39, and 45 is the upper surface of the upper mold 34. It is a military weight that will be reloaded on the. In addition, the corresponding dowel 45
A gate 47 for pouring molten metal is bored at a position corresponding to the sprue 46. In the present invention having the above-mentioned structure, the operation will be explained next.As shown in FIG.
When the formwork device 9 is located at the molding station 11 (at this time, the second formwork device 10 is located at the molding station 12).

), first, the upper and lower formworks 7 and 8 approach each other by the action of a pressure cylinder (not shown), and pressurize the match plate 18 from both sides. Next, the squeeze plates 13 and 14 move forward and insert iron into the upper and lower formworks 7 and 8 from the back, and the respective parallel surfaces 2
It stops at the set position at 6 and 29. At this time, the positions at which the squeeze plates 13 and 14 stop are appropriately set in advance according to the height of the model of the match plate 18. Further, the tip of the sprue model 20 is in contact with the match plate 18. In a state where a sealed state is achieved by the sealing material 33 between the squeeze plates 13, 14 and the parallel surfaces 26, 29 of the upper and lower formworks 7, 8, the molding sand supply device 19 is lowered and its feeding gates are moved upward and downward. After the molding sand is brought into close contact with the molding sand openings 31 and 32 of the molds 7 and 8, the molding cavity is filled with molding sand by a known blowing operation using pressurized air. When the molding sand is filled, the squeeze plate 13,
14 further advance toward the match plate 18 to compact the foundry sand, and then the squeeze plates 13 and 14 retreat, respectively, and the upper and lower formworks 7 and 8 are also integrated with the compacted foundry sand. The mold release operation is performed by retracting away from each other. At this time, due to the frictional force between the compacted foundry sand and the surface of the model, a separation force acts between the compacted foundry sand and the inner circumferential surfaces of the upper and lower molds 7 and 8, especially the upper mold. For frame 7, taper surface 27
Even if this action were facilitated due to the shape of , the frictional forces on the parallel surfaces 26 would be sufficient to prevent separation.
In the lower formwork 8, the separation is effectively prevented not only by the frictional force on the parallel surface 29 but also by the shape of the tapered surface 30. When the mold release operation is completed, the rotary table 3
rotates 180 degrees, and the first formwork device 9 moves to the frame removal station 1.
2, the second formwork device 10 moves to the molding station 11 and stops. Even in the middle of movement due to the rotation of the rotary table 3, the molding sand compacted by vibration and far-zero force is separated from the upper and lower formworks 7 and 8 by the parallel plane 26, respectively.
, 29 is effectively prevented. Regarding the second mold device 10 located at the molding station 11, the same molding operation as described above is performed, while at the frame punching station 12, the following mold matching and frame punching operations are performed.

In other words, after inspecting the mold and inserting the core if necessary, the upper and lower mold frames 7 are
8 are brought close to each other and the molds are matched, and the mold receiving plate 21 is raised and brought into contact with the lower end surface of the lower mold frame 8, or directly brought into contact with the lower end surface of the mold in the lower mold frame 8. In this state, the press plate 23 is lowered and the mold is pushed up against the frictional force with the inner circumferential surfaces of the upper and lower molds 7 and 8 to remove the molds, thereby removing the molds that have received the upper and lower molds 34 and 35. The receiving plate 21 descends,
It stops at a position where its upper surface is at the same height as the upper surface of the conveyor table 42 (see FIG. 3). The upper and lower molds 34 and 35 are extruded onto the conveyor table 42 by the operation of the competitive extrusion device 43. At this time, if the tip of the extrusion device 43 is set so as to touch the parallel surface 41 of the lower mold 35, the extrusion direction will be perpendicular to the side surface of the lower mold 35, so that no harmful external force will be applied to the mold. It has no effect. Then upper and lower mold 3
4 and 35 are transported to the tin manufacturing process by a known transporting means, during which time the tapered surfaces 3 of the upper and lower molds 34 and 35
8 and 39, and a dowel 45 is placed on the upper surface of the upper mold 34 (see FIG. 4). In this state, molten metal is injected into the product forming cavity 37 through the gate 47 and sprue 46 of the weight 45 in the rimming process. At this time, almost the entirety of the product molding space 37 is laterally loosened by the cover frame 44, and the inner peripheral surface of the cover frame 44 is held in close contact with the tapered surfaces 38, 39 of the upper and lower molds 34, 35. Therefore, the mold is not destroyed by the static pressure of the setting sun, the pressure of the sardines, etc., and by the force of the cover frame 44 to hold it in close contact and the pressing force due to the gravity of the gun weight 45,
Separation at the mating surfaces of the upper and lower molds 34, 35 during Western moat can be effectively prevented. As described above, according to the present invention, only the part of the side surface of the frameless upper and lower molds that surrounds the product molding space in the vicinity of the mold-matching surface is a continuous tapered surface, and the remaining part is a parallel surface perpendicular to the mold-matching surface. By making it a flat surface, during molding, it is possible to prevent the inconvenient separation of the mold from the formwork during molding and the subsequent separation due to vibrations, etc., and prevent the destruction of the mold due to falling from the formwork. In addition, since the extrusion device for horizontally transferring the mold can be operated against the parallel surface of the side surface of the lower mold, this also contributes to preventing damage to the mold. It is possible to effectively utilize the reinforcing effect of the mold by the cover frame, and furthermore, in the equipment for manufacturing the mold,
The squeeze plate inserted into the formwork for compacting the foundry sand can be freely slid onto a parallel surface placed within the formwork for the required distance in the direction of the rocky shore. During blowing, it is possible to stop at an appropriately set position according to the height of the model, and each mold can be made with the optimum amount of foundry sand, which makes it possible to save molding sand. This has the remarkable effect of significantly improving productivity by interacting with each other.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, in which Fig. 1 is a front view showing the entire mold making machine, Fig. 2 is an enlarged cross-sectional view of main parts, and Fig. 3 is a front view showing the entire mold making machine.
The figure is a front view showing the upper and lower molds that have been matched, and FIG. 4 is a front view showing the state of the mold when it is used for Western hot water. 7, 7'... Upper formwork, 8, 8'... Lower formwork, 9... First formwork device, 10...
Second formwork device, 11... Molding station, 12...
... Frame removal station, 13, 14 ... Squeeze plate, 18 ... Match plate, 19 ... Foundry sand supply device, 21 ... Mold receiving plate, 23 ...
・Press plate, 26, 29...Parallel surface, 27, 30
...7-pa side, 34...Top mold, 36
1...Lower mold, 36...Mold matching surface, 3
7... Product molding space, 38, 39... Pooper surface, 40, 41... Parallel surface, 43...
・Extrusion device, 44... Covering frame, 45...
Weight. Figure 3 Figure 1 Figure 2 Figure 4

Claims (1)

[Claims] 1. A pair of upper and lower molds with horizontal mold mating surfaces, each of which has an outer surface in the vicinity of the mold mating surface in a continuous tapered shape that expands downward so that it can be brought into close contact with the inner circumferential surface of the cover frame. A frameless mold characterized in that the remaining outer surface is a parallel surface perpendicular to the mold matching surface. 2. A molding mold comprising a pair of upper and lower molds that have molding sand supply openings on the sides and can squeeze the match plate from both sides at the front thereof, and a squeeze plate that can be inserted from the back of the upper and lower molds. In the machine, the inner circumferential surfaces of the backs of the upper and lower molds are parallel surfaces on which the squeeze plate can slide by an appropriately set distance and have a portion that substantially contacts the molding sand even after compaction of the molding sand. The front inner circumferential surfaces of the upper and lower formworks are continuous with the parallel planes, and the upper formwork has a tapered surface that widens toward the front end surface, and the lower formwork has a front inner circumferential surface. The tapered surface is tapered toward the end surface, and the inner circumferential edges of the front end surfaces of the upper and lower formworks are aligned with each other in the axial direction of the upper and lower formworks, and the inclination angles of both the tapered surfaces are equal. Features: Frameless mold manufacturing equipment.