Metal founding – Means to shape metallic material – United particle type shaping surface
Reexamination Certificate
1999-02-23
2001-06-12
Lin, Kuang Y. (Department: 1722)
Metal founding
Means to shape metallic material
United particle type shaping surface
C164S360000, C164S365000, C164S384000, C164S392000
Reexamination Certificate
active
06244328
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a mold and a process for the manufacture of a mold comprising a molding flask formed of two molding-flask halves, which molding flask has means for the transport on automatic mold systems and receives a bound sand mold, which sand mold, if necessary, is provided with cores and with a pouring funnel and a feeder.
BACKGROUND OF THE INVENTION
Molds with bound molding sand are either manufactured with molding flasks, which consist of two molding-flask halves, whereby this molding flask is as a rule constructed frame-shaped and has running boards on its front and rear sides, with which the molding flask can be transported on a roller train of an automatic mold system. This molding flask provides the sand mold bound therein the necessary strength so that same can be easily transported. The sand for the mold can be clay-bound, which guarantees an inexpensive reprocessing of the molding sand.
Molds without flasks are also known and are assembled dependent on the casting out of a plurality of individual parts, whereby these molds are no longer clay-bound but are chemically bound in order to obtain a sufficient strength for their handling and casting ability. These chemically bound sand molds require expensive machines for the manufacture of the partial molds and cores and machines for, in turn, assembling these parts to form a mold. Aside of the high input of machines, which must here take place, a further disadvantage is that the reprocessing of the sand is difficult. This represents a high expense factor in addition to the expensive molding and mounting machines.
Green-sand molds without a flask are also known and are built of individual identical square-shaped blocks, which have on two oppositely lying sides each defining a portion of the mold cavity. The casting inlet and also the feeder is hereby formed in the blocks. These blocks are then moved towards one another so that their mold cavity portions supplement and support one another. The molding sand is thereby shot in from above, which means that the mold areas, which lie in the shape of the model, do not solidify like the remaining areas. Furthermore the feeder can only exist to a limited degree in the mold and also essentially only laterally of the actual mold cavity, which strongly limits the quality of the feeder. By shooting in the molding sand moreover also a large wear on molds occurs, which makes the process expensive. A further disadvantage is that the cores must be inserted into a laterally directed mold and this must be done in the available cycle time, which on the one hand demands expensive automatic machines and on the other hand is dangerous manual work. An important disadvantage is furthermore that such green-sand molds without a flask are not suited for the manufacture of complicated castings, as for example engine blocks or cylinder heads, in particular when these consist of aluminum.
Moreover, molding sand in molding flasks can not only be clay-bound but is also significantly less expensive to manufacture. In order to manufacture such a molding flask one must merely place each one half of the molding flask separately onto a model plate, whereby the molding flask is then filled with sand. After mechanically compressing the molding sand, the mold half is finished. The horizontally lying mold half is then turned upwardly with the mold cavity therein so that cores can be inserted. The molding flasks are placed one on top of the other for casting, whereby earlier the mold opening and the feeder must be worked into the molding sand in the then upper molding-flask half. This is done prior to the turning of the upper molding flask by using rotating tools. These molding flasks are then cast in a lying position, whereby it is here disadvantageous that only a relatively small volume remains for the feeder in the mold and in addition the feeding of the mold parts lying at the mold bottom is not always optimally achieved.
Whereas it is no problem in the chemically bound molds without a flask to form the feeder and also the pouring funnel right away in the mold, whereby the feeder and pouring funnel are arranged on the side of the mold, which is the most advantageous position for casting of the casted part. The feeding of the solidifying casting is thus significantly more advantageous in chemically bound molds without a flask compared with molds with molding flasks. In particular, it is not necessary to additionally mount yet another feeder onto the molding flask in order to produce the hydrostatic pressure required for the feeding. Of course, these molds are not only expensive with respect to material and manufacture but also demand extremely high installation capital.
It is indeed possible in the case of manufacturing the green-sand molds without a molding flask to at the same time manufacture the pouring funnel without any relieve problems, however, the construction of the feeder creates problems especially since the feeder reduces the cross section available for shooting in the sand. Such molds are less suited for the pouring in of aluminum especially since here large effective feeders are needed.
The core ventilation represents a significant problem both in the case of molds without flasks and in the case of molds with molding flasks, which problem has up to now not been satisfactorily solved.
SUMMARY OF THE INVENTION
The basic purpose of the invention is to construct a mold with a molding flask, which has a mold of a bound molding sand, in such a manner that same can be utilized in automatically working mold systems and can be manufactured horizontally in the usual manner, in which additional finishing steps on the pouring funnel and the feeder and also additional feeders to be placed onto the mold are not needed, and moreover an effective ventilation of the cores if guaranteed in the mold. A further purpose of the invention is to provide a process for the manufacture of such a mold.
This purpose is attained for a mold of the above-identified type in accordance with the invention in such a manner that the molding flask has in the area of its parting plane a recess extending over at least one portion of the length and width of one side of the molding flask, that the pouring funnel and the feeder end in the area of the recess, and that the feeder is constructed within the bound molding sand in the mold.
Thus the molding flasks for molds with bound molding sands can be manufactured in the usual manner, namely the frame of the molding flask is placed onto a model plate, is filled with sand and is compressed. The two molding-flask halves are manufactured in the same way. The difference of the present molding flasks with respect to the conventional molding flasks is that the feeder and pouring funnel are no longer constructed on the open side of the mold frame, namely on the upper open molding-flask half, but that the opening before the pouring funnel and also the feeder is placed along the parting plane of the molding-flask. This means that the casting operation involving the mold occurs no longer with the mold lying horizontally, as is the case in conventional molds with molding flasks, but instead occurs in a standing (vertical) position. By shifting the pouring opening and also the feeder into the mold parting plane and through the so caused standing casting operation of the molding flask, it is possible to form the feeder and the pouring funnel without any additional input (steps) at the same time as the mold is manufactured so that any additional finishing is not required. Moreover, since the casting operation involving the mold occurs in a standing position, there remains as a rule sufficient space above the casting in the mold to house the needed volume for the feeder. Also this relatively large space makes it possible to construct the feeder in such a manner that the necessary hydrostatic pressure for feeding is obtained.
According to an advantageous embodiment of the invention, the cores are arranged with one end extending upwardly through the opening in the mold fr
Flynn ,Thiel, Boutell & Tanis, P.C.
Heinrich Wagner Sinto Maschinenfabrik GmbH
Lin Kuang Y.
LandOfFree
Mold for automatically working mold systems and a process... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Mold for automatically working mold systems and a process..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mold for automatically working mold systems and a process... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2547533