JPS6336950A - Method and device for manufacturing mold, etc. - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION According to the first idea, the invention provides that the mold cavity is injected by at least one jerky suction method through an inlet slit and that by moving at least the boundaries of the mold cavity. Concerning a method for producing in particular horizontal caseless molds or cores etc. from sand which is later compacted mechanically and, according to a second idea, a mold cavity which can be connected to a vacuum source. The mold plate has an entrance slit connected to the mold plate and the sand pin and can be moved like a stamp by a lifting mechanism to engage a pressing plate on the opposite side of the mold plate in order to form a part. The present invention relates to an apparatus for carrying out the method, comprising at least one enclosing case capable of carrying out the method.

Japanese Patent Application No. 61-035389 describes a method and apparatus of this design. After the application of the first vacuum, the sand introduced into the mold cavity by the method is supplied with compressed air and is then simply mechanically compressed. The inlet slit extends to a closed housing, while the application of compressed air and mechanical post-compression take place. For this purpose, the inlet slit is rotatably supported in the pressure plate and located in a roller lying flat on its periphery. The disadvantage of this design is that for the application of vacuum and therefore compressed air to the mold cavity, it is relatively expensive since the mold cavity has a surrounding case and a mold plate or in fact an upward sealing direction for each pressing plate. must be sealed against downward and upward pressure at the junction between the If the seal is inaccurate, this can result in unwanted air ingestion when vacuum is applied and sand being released into the environment when compressed air is applied. Since both efficiency and the environment are affected, it cannot be called an effect. Special arrangements suitable for the application of vacuum and compressed air require additional costs; in addition, when the mold cavity is supplied with compressed air, the introduced air must be discharged again via the mold plate. This should be taken into account. Son
Therefore, the unexamined Federal Republic of Germany Patent Specification No. 3,507
, 179 can be used in a hollow template that simply has a special arrangement for draining compressed air.

In addition, the application of compressed air can be carried out only when the inlet slit is closed. A more expensive device in the form of a rotatable roller for opening and closing the inlet slit is therefore required. Such parts that move within the sand are easily worn out, resulting in the prospect of reduced lifespan.

Another drawback is that when compressed air is applied, air is introduced into the sand that has already been precompacted by the application of vacuum. This causes a so-called springback effect. That is, the enclosed air not only expands after mechanical pressing, which has a disadvantageous effect on the precision to be achieved, but also makes smoking in the casting condition desirable to create favorable working conditions in the mold. It is possible to lead to

In view of this prior art, the present invention therefore not only simplifies the process, but also ensures a simple and easy hardware arrangement.
and it consists in improving the previously proposed methods and apparatus by simple and economical means so that a high quality of production is nevertheless achieved. To achieve this aim the whole manufacturing process Vacuum application is immediately followed by a mechanical post-compression with an inlet slit to allow the sand stay to remain open during the process. In this design, the inlet slit of the pressure plate cannot therefore be moved and is defined by a solid wall.

These means direct the inlet slit upwardly or downwardly.
To ensure that there is no need for moving parts to guide each other. Therefore, this results in a very simple and economical design as well as high durability. There is no evidence of the disadvantage that the inlet slit stay is open during the entire manufacturing process without the application of compressed air. An open inlet slit cannot conduct pressure to reach the sand or sand pins pushing out of the mold cavity and results in undesired compaction of the sand. On the other hand, it is ensured that as much air as possible is removed from the sand in the casting state of the cells without risk of smoking the mold. At the same time, this
Also, due to the absence of air, there is no or almost no springback effect after the compression process, thus ensuring high precision of the manufactured product. The present invention ensures that only a vacuum seal is required, which can be reliably achieved by relatively simple means. The filter prevents sand from escaping from the mold cavity. In addition, it is also necessary to discharge the compressed air, thus further simplifying the design and opening up new possible configurations and fields of application.

The present invention no longer relies on hollow templates, but can also be applied to e.g. rigid templates used on one or both sides. This makes the object of the invention simple and Show that it can be achieved by economical means.

According to an advantageous further development of the invention, several
Preferably two vacuums can be applied in succession.

This advantageously leads to a particularly uniform compaction of the sand over the entire cross-section of the mold, and the reason for this is preferably that the sand actually delivered by the second vacuum application and perhaps other applications that follow is not affected by the previous vacuum. This means that it takes on less of the compression part. The result therefore is excellent filling of the sand mold cavity and substantially uniform compaction even though relatively deep molds are used.

As part of another advantageous development of the invention, the application of the vacuum comprises at least one nozzle which is accessible from the mold cavity.
This can be carried out by supplying vacuum to two hollow pressure plates. The sand entering the mold cavity via the inlet slit of the pressure plate moves in any case towards the mold plate and is opposed by its inertia to the pattern, which does not depend on the suction of the mold cavity. By supplying a vacuum to the hollow pressure plate, it is therefore ensured that sand accumulates in the suction opening leading to the mold cavity only when the mold cavity is practically completely flushed. The energy supplied in the form of a vacuum can thus be used advantageously during the entire manufacturing process. Sufficient compaction is also ensured in the lower part of the mold, as f'L means a virtually uniform force during the entire filling process.

There is no need to apply a vacuum to one or more pressure plates.
It can be carried out on the fL itself or in combination with the application of a vacuum to the template and/or the surrounding case. Such a combination makes it possible to apply a vacuum to the pressure plate with a delay, which is practically no second application and which therefore results in a particularly good filling of the mold cavity. If only the pressure plate is supplied with vacuum, there is no need for supply lines leading to the mold plate and/or the surrounding case. In that case, the mold plate and the case do not have to be hollow and have the shape of a solid component. According to yet another advantageous development of the invention, the entry loss slit may have its smallest cross section at its opening towards the mold cavity. As a result of the sand having maximum acceleration, it helps particularly well to fill the mold cavity.A particular advantage of this design is the minimum cross section at the entry during the mechanical post-compaction.

It is ensured that only relatively valuable sand is suppressed in the open inlet slit and that this sand is removed when the pressing plate returns. In that case, the fracture is caused outside the pressing plate so that there are no high spots on the surface of the finished mold. The finished mold can therefore be placed on a pallet or loaded with heavy objects without risk of evolution.

Further useful advantages of the invention and advantageous derivatives thereof will be understood from the following detailed description of embodiments, as detailed in conjunction with the accompanying drawings.

The illustrated apparatus allows simultaneous production of upper and lower pails of the mold. The device therefore accommodates a template 1 which is housed in a substrate in a manner not described in detail here and is provided with models 2 on its upper and lower sides. Opposite each side of the template 1 with the model 2 there is a pressing plate 4 which can be moved by a lifting mechanism in the form of one or several piston assemblies 5 supported on the base plate.
The distance between each pressing plate 4 and the side of the template 1 facing this n is bridged by an enclosing case n1 and the enclosing case 6
are supported on the substrate so that they can slide perpendicularly to the respective planes of the substrate. Two mold cavities 7 are thus created, each defined by the mold plate 1, the pressure plate 4 and the case 6 which engages with it. The joint between the case 6 and the mold plate 1 or the respective cooperating pressure plate 4 is such that when a vacuum is supplied to the mold cavity 7, air from outside is drawn in so that unwanted air is sucked into the mold cavity 7. Each is sealed against each other.

The pressing plates 4 each have one inlet slit 8 which is symmetrical about the central longitudinal plane and serves to fill the mold cavity with sand. Each inlet slit 8 is molded directly into the cooperating pressure plate 4 and defined in a solid wall 9. There is no closing mechanism cooperating with the inlet slit, which remains open at all times.
It cooperates with a sand pin 10 placed on the pressing plate 4 of which is moved like a stamp in connection with the case 6 of the invention. The upper and lower sand pins 10 are connected to each other by a lateral outflow tube 11 which is telescopically held together so that the sand pins 10 can be filled together.

The mold cavity 7 is filled by one or several applications of vacuum. In each case, this refers to the jerky inhalation method. For this purpose, each mold cavity 7 is connected to a vacuum source, here in the form of a tank 13, which can be evacuated by a pump. The flow path from the mold cavity 7 to the tank 13 can thereby extend via the mold plate 1 and/or the pressure plate 4 and/or the housing 6. In the embodiment shown here, suction of the mold cavity 7 can be carried out via the mold plate 1 and the pressure plate 4. For this reason, the template 1 has a cavity 15, and this cavity 15 is connected to the vacuum conduit 14.
It is connected via a tank 13 to a tank sealed by a sand filter 16 and to the mold cavity 7 via a nozzle 17 arranged above at the edge of the mold cavity. In this embodiment, the pressure plate 4 also has a cavity 19 which is connected to the tank 13 via the respective vacuum conduit 18 and here uniformly distributed over the entire surface and each sealed by a sand filter 20. It is connected to the cooperating mold cavity 7 via a nozzle 21 extending therethrough.

If suction can also take place via the case 6, these have the same shape and are connected to the tank 13. Here, the case 6 does not have any voids because suction is not performed through the case. For simplicity,
The cavities 15- or 19 are not subdivided in the embodiment shown here.

However, several chambers formed by vertical partition walls and separately supplied with vacuum can be provided in the cavity 15 or 19, respectively.

The mold plate 1 is separated by a horizontal partition wall in the area cooperating with the upper mold cavity 7 and in the area cooperating with the lower mold cavity 7.
The void 15 can be subdivided.

Then, in each vacuum conduit 14 or 18 there is a shutoff device 2.
2, and the shutoff device 22 is connected to the control mechanism 23 by the shutoff device [
A control mechanism 23 is connected to the control mechanism 23 as shown by a signal line 24 extending to 22.
can be activated or deactivated respectively. In the illustrated embodiment, the control mechanism 26 is 1'! or several subsequent vacuum applications are programmed to be optional. Application of jerky vacuum to the mold cavity 7 is as follows.
5A sand pins 10 via the cooperating inlet slits 8 into the mold cavity 7 as well as at the same time compaction of the sand. The sand substantially retains its direction of motion imparted in the inlet slit 8 and therefore
is accumulated in the opposite model 2 and compressed at the same time. In simple, not very deep molds, one application of vacuum is sufficient to compact the sand sufficiently and substantially uniformly; in more complex, deeper molds, several subsequent vacuum applications An application can be performed. Several successive vacuum applications preferably move the sand to locations where the previous application caused less compaction, so that at the end there is a substantially uniform compaction over the entire cross section. Vacuum can be supplied to the respective voids 15 or 19 of the mold plate 1 and the press plate 4 at the same time. In the illustrated embodiment, the cutoff device 22 first applies the vacuum source to the cavity 15 of the template 1 and then, after a short delay, the cavity 19 of the pressure plate 4.
The chamber is connected to and controlled so as to effectively apply the effect of two successive vacuum applications. Nozzle 2 of press plate 4
1 or cooperating sand filter 20.

Until the cooperating mold cavity 7 is completely filled, it is not free to be covered by sand, so that the vacuum application via the pressure plate 4 is applied to the mold plate 1 and/or the case 6. A sufficient effect can be obtained even if the vacuum has been previously applied one or several times through the application of a vacuum. It can further be compressed by mechanical compression methods. This method of compression follows the application of vacuum to the mold cavity 7 immediately, ie without intermittent application of compressed air.

To carry out the compression method, a lifting mechanism 3 cooperating with a pressure plate 4 is activated. This is performed by the control mechanism 23 as shown by a signal line 25 extending from the control mechanism 23 to the lifting mechanism 3. The use of the lifting mechanism 3, which is in the form of a hydraulic or respectively pneumatic cylinder-piston assembly, is to move the pressure plate 4 into a cooperating case 6, such as a stamp. The template Bat is fixed to the substrate using the method. The case 6 can be supported by the template 1. At the end of the compression process, the pressing plate 4 is lifted by mm5
It can be returned by using it in reverse. Then case 6
can be removed or removed. For this purpose, the case 6 is connected to a removal mechanism 26 in the form of a lifting cylinder or the like. The removal process is also controlled by a control mechanism 23. The mold pail released by the removal of the case 6 is placed together with the two-part mold, with the lower pail stored on a pallet and with a cooperating upper pail that can be loaded with heavy objects. The inlet slit 8 of the pressing plate 4, covered by the pail, is formed so as to have its smallest cross section at the opening towards the cavity 7, which leads to a large acceleration of the sand near the inlet.

The entrance slit 8 always remains open. This also applies to the compaction process carried out by the lifting mechanism 3, so that the bulk sand is forced back into the inlet slit 8 when the compaction method is carried out. The sand does not appear in the form of bumps or the like in the finished mold. When the pressure plate 4 is lifted from the cooperating pail of the mold, the fracture occurs by a fracture lfM27 outside the inlet slit 8. Said break line 27 is in line with the adjacent surface of the mold or somewhat low, but not so high that it can be placed on the lower pail or pallet of the mold, and the upper pail can be loaded with heavy objects without problems. . In the illustrated embodiment, the area of the solid side wall 9 of the inlet slit 8 located close to the opening is inclined at an angle of approximately 10° to the central longitudinal plane, the sides of the inlet slit 8 being flat, lower molds. It can also be in the form of an inclined plane as in the inlet slit 8 cooperating with the cavity 7 . But also the inlet slits 8 remote from the cooperating mold cavity 7 are inclined towards each other, as in the inlet slit 8 cooperating with the upper mold cavity.
This aspect is also possible. However, the designs described up to and fL refer to advantageous embodiments of the invention without limiting its use. On the contrary, there are many possibilities open to the expert to adapt the general aspect of the invention to the requirements of a particular situation. For example, it is also possible to have a template in the form of a so-called match plate and connect only the pressure plate to the vacuum source.

[Brief explanation of the drawing]

The drawing is a partial cross-sectional view schematically illustrating the invention. In the figure, 1 is a template, 2 is a model, 3 is a lifting mechanism, 4 is a press plate, 6 is a surrounding case, 7 is a mold cavity, 8 is an entrance slit, 9 is a solid wall, 10 is a sand pin, 13th is 7pm,
18 is a vacuum conduit, 20 is a sand filter, 22 is a shutoff device, and 23 is a control mechanism. Procedural amendment October 3, 1986

Claims (13)

[Claims] (1) Especially horizontal sand from sand which is injected into the mold cavity via an inlet slit by at least one jerky suction method and which is later compacted mechanically by moving at least one border of said mold cavity. A method for manufacturing caseless molds, cores, etc., wherein said inlet slit is provided for introducing a sand stay that is open during the entire manufacturing process, and includes a mechanical post-compaction that immediately follows the application of a vacuum. A method for manufacturing a mold, etc., characterized by: (2) The method for manufacturing a mold, etc. according to claim 1, characterized in that several, preferably two, vacuum applications are applied. (3) A method for manufacturing a mold, etc., as set forth in any one of the preceding claims, characterized in that at least one vacuum application is performed via a pressing plate that cooperates with each mold cavity. (4) The method for manufacturing a mold, etc. according to any one of the preceding claims, characterized in that the at least one vacuum application is performed via a template that cooperates with each of the mold cavities. . (5) The method for manufacturing a mold or the like according to any one of the preceding claims, characterized in that the at least one vacuum application is performed through a case that cooperates with each of the mold cavities. (6) The method for manufacturing a mold or the like according to any one of the preceding claims, wherein at least the template and one or more pressing plates are each supplied by vacuum. (7) The mold manufacturing method according to claim 6, wherein the one or more pressing plates are supplied with a vacuum for each vacuum application. (8) To form a mold cavity that can be joined to a vacuum source,
comprising at least one enclosing case which can be adapted to engage a template and a pressing plate opposite thereof, said pressing plate having an entry slit connected with a cooperating sand pin and by a lifting mechanism; 10. Claims according to any one of the preceding claims, characterized in that the inlet slit of each pressure plate is defined by an immovable and solid wall, such that the inlet slit of each pressure plate is moved like a stamp. Manufacturing equipment such as molds that applies the claimed method. (9) The apparatus for manufacturing a mold or the like according to claim 8, wherein the inlet slit has a minimum cross section at an opening that cooperates with each mold cavity. (10) At least in the vicinity of the mold cavity, the side surfaces of the inlet slit are inclined toward the longitudinal central plane of the inlet slit, preferably at an angle of about 10°. A manufacturing device for molds, etc., according to item 9. (11) The one or more mold cavities include the template,
Mold according to any one of claims 8 to 10, characterized in that at their junction between the case and the pressure plate, it is sealed exclusively under pressure. etc. manufacturing equipment. (12) A control device is provided, by which the supply of the one or more mold cavities by vacuum is turned on and off. A manufacturing device for molds, etc. according to any one of the items. (13) The method for manufacturing a mold or the like according to claim 12, wherein vacuum can be supplied to the mold cavities independently of each other by the control device.