Abstract:
A permanent mold casting system has a modularized architecture and remote placement of certain portions of the casting system. The casting system has a frame and a casting module supported on the frame is adapted to receive a plurality of molds for casting articles from a fill material according to a casting process. The casting module includes first motive actuators for moving at least portions of the molds during the casting process. An accessories module is supported on the frame and comprises at least one accessory device and second motive actuators for selectably positioning the accessory device in relation to the casting module. A utility module is located remotely from the frame and comprises motive power supplies coupled to the first and second actuators. The utility module also comprises a programmable controller coupled to the motive power supplies for controlling the casting process.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to permanent mold casting machines, and more specifically to increasing the productivity of a casting machine using a particular modularization that facilitates the use of multiple molds in one machine. 
     It is known to use a casting machine having a casting mold to make cast articles. Examples of cast articles include aluminum pistons and wheels, and various plastic pieces used in a wide variety of industries. The casting mold typically has two or more mold sections, such as for example a first mold half and an second hold half. When the first mold half and the second hold half are placed together, they define a cavity. The cavity is in the general shape of the cast articles to be produced. A fill material, such as metal or plastic is inserted (e.g., poured) into the cavity and allowed to cool. The first mold half and the second hold half can then be separated from each other, leaving the cast article. 
     Various motive devices (such as hydraulic actuators, motor drives, and servo-mechanisms) are used on casting machines for moving mold sections into place and then retracting them, for tilting the machine to improve flow of the fill material, for removing finished articles, and for other purposes. These devices each include a mechanical actuator portion (e.g., a hydraulic cylinder) and a motive power supply portion (e.g., an electrically-controlled valve and fluid supply lines feeding the hydraulic cylinder). For complicated articles using multiple mold sections and complex processing, the number of motive devices can become quite large on a single casting machine and can occupy a significant amount of space. 
     In order to speed cooling of fill material in a mold and sometimes to control the cooling rate, cooling channels carrying cooling fluid are deployed within and/or around the mold. Control valves mounted on the casting machine turn fluid flow on and off and/or modulate the flow to provide the desired cooling profile. 
     The casting machine typically includes a programmable controller having operating instructions that govern movement of the mold sections, filling of the cavity with the fill material, tilting of the machine, and the like. The controller is generally relatively expensive and is dedicated for use with a single casting machine. In normal operation, a casting machine is subject to “down time” due to a variety of causes, resulting in a period of non-productivity. This non-productivity results in the dedicated controller also being unused, and represents a waste of the capital invested in the controller. Furthermore, the dedicated controller is typically mounted to the casting machine itself, using up more of the limited space available in a single machine. 
     Due to the space and packaging requirements of all the various components of a casting machine, the prior art has severe limitations in the number and arrangement of molds that can be supported in a single casting machine. Furthermore, the close spacing and crowded arrangement of components makes maintenance of the components more difficult and costly. 
     SUMMARY OF THE INVENTION 
     The present invention has the advantages of reduced cost and improved performance as a result of a modularized architecture and remote placement of certain portions of the casting system. 
     In on primary aspect, the invention provides a casting system having a frame. A casting module is supported on the frame and is adapted to receive a plurality of molds for casting articles from a fill material according to a casting process. The casting module includes first motive actuators for moving at least portions of the molds during the casting process. An accessories module is supported on the frame and comprises at least one accessory device and second motive actuators for selectably positioning the accessory device in relation to the casting module. A utility module is located remotely from the frame and comprises motive power supplies coupled to the first and second actuators. The utility module also comprises a programmable controller coupled to the motive power supplies for controlling the casting process. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an elevational schematic of a casting system according to the invention. 
     FIG. 2 is an elevational schematic side view of the casting system shown in FIG.  1 . 
     FIG. 3 is a top plan view of the casting system shown in FIG. 1 viewed along line  3 — 3 . 
     FIG. 4 is a top plan view of a mount used with the accessories module for the casting system shown in FIG.  1 . 
     FIG. 5 is a schematic of a cell having four casting modules and a utility module according to the invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The components for, and use in, the casting system will generally be discussed in the context of their use for producing a piston. The piston is a non-limiting example of a cast article that may be produced with the invention. It is contemplated that the casting system of the invention is useful in a wide variety of manufacturing applications. 
     Referring now to FIGS. 1 through 3, there is illustrated a casting system, shown generally at  12 , in accordance with the present invention. The casting system  12  preferably includes a support structure module or frame  16 , a casting module  20 , an accessories module  24 , and a utility module  28 . For purposes of clarity, only those portions of the casting system  12  necessary for the understanding and description of the invention will be discussed herein. 
     The support structure module  16  is positioned and provided in the casting system  12  to support and stabilize the casting module  20 . The illustrated support structure module  16  includes four legs  32   a-d . The legs  32   a-d  are generally vertically extending beams having a generally square cross-sectional shape. The illustrated legs  32   a-d  may be bowed slightly outwardly to accommodate the casting module  20  positioned therebetween. The illustrated legs  32   a-d  include lower supports  36   a-d . The lower supports  36   a-d  are provided to stabilize the support structure module  16 . The illustrated support structure module  16  also includes one or more beams  40   a  and  40   b  to connect the leg  32   a  to the leg  32   b  and the leg  32   c  to the leg  32   d , respectively. A number of plates, including plates  44   a-d  on the front legs, add support and stability. Similar plates are used on the rear legs such as plate  44   e  in FIG. 2 (plate  44   a  is removed from FIG. 2 to show other detail). 
     The illustrated support structure module  16  also includes two pivots  48   a,b . For the illustrated casting system  12 , the pivots  48   a,b  are positioned near the top of the support structure module  16 , although they may be positioned at any suitable location. FIG. 2 shows an axis “A” positioned generally vertically through the pivot  48   a . The pivots  48   a,b  are positioned to allow the casting module  20  to be positioned at a tilt with respect to the support structure module  16 . The casting module  20  is positioned at an angle “B.” The angle “B” is a tilt angle, and can range up to about 20° from vertical in either direction, for example. Of course, the machine can be constructed to provide any desired forward or backward tilt as needed for any particular manufacturing application. The casting module  20  can be used to produce cast articles by stationary methods, tilt methods, or both. 
     The illustrated support structure module  16  also includes a tilt assembly  52 , shown in FIG.  2 . The support structure module  16  may include more than one tilt assembly  52 . The tilt assembly  52  is operative to facilitate positioning of the casting module  20 , such as for example when the casting module  20  is positioned at a tilt. The illustrated tilt assembly  52  includes a first plate  56  and a rod  60  and a second plate  64  and a receiver  68 . The second plate  64  is operatively connected to the casting module  20 . The rod  60  is part of a hydraulic actuator that slideably engages the receiver  68  to selectively change the tilt position of the casting module  20 . 
     The tilt assembly  52  of FIG. 2 is shown in a retracted position, with the casting module  20  being positioned at the angle “B” of about zero. The tilt assembly  52  can also be positioned in an extended position. When the tilt assembly  52  is positioned in the extended position, the position of the first plate  56  and the position of the second plate  64  change with respect to each other. In other words, the tilt assembly  52  operates to increase the space between the first plate  56  and the second plate  64 . 
     The illustrated support structure module  16  also includes two suspension plates  72   a,b . The plates  72   a,b  are pivotally connected to the pivots  48   a,b  respectively. The plates  72   a,b  are also operatively connected to the casting module  20 . The plates  72   a,b  are positioned to allow the tilt position of the casting module  20  to selectively be positioned at the angle “B.” 
     The casting module  20  is positioned and provided in the casting system  12  to produce a cast article. The illustrated casting module  20  includes two first mold halves  100   a,b  and two second mold halves  104   a,b . The illustrated first mold halves  100   a,b  and the illustrated second mold halves  104   a,b  cooperate to define cavities  108   a-d . The illustrated casting module  20  includes four cavities  108   a-d , though any suitable number of cavities may be included. The illustrated cavities  108   a-d  are spaced apart from each other and are generally cylindrical openings. The first mold halves  100   a,b  and the second mold halves  104   a,b  are positioned together to define part lines  112   a,b  between them. In operation, the first mold halves  100   a,b  and the second mold halves  104   a,b  moved toward and apart from each other at the part lines  112   a,b.    
     The illustrated casting module  20  includes two fill inlets  116   a,b . The illustrated fill inlets  116   a,b  are generally square openings. The illustrated fill inlet  116   a  is positioned between, and is in fluid communication with, the cavities  108   a,b . The illustrated fill inlet  116   b  is positioned between, and is in fluid communication with, the cavities  108   c,d . In operation, a fill material is placed into the fill inlets  116   a,b . The fill material may be placed into the fill inlets  116   a,b  in any suitable manner, such as for example by gravity pouring from a ladle. The fill material flows or otherwise moves from the fill inlets  116   a,b  into the cavities  108   a-d . Positioning the casting module  20  at a tilt may enhance the casting process by improving filling of the cavities  108   a-d  and reducing casting scrap. 
     In addition to the hydraulic cylinder for tilting, casting module  20  includes other motive actuators for moving various components of the machine, such as the mold sections. For example, horizontal hydraulic actuators  25  are arranged for moving mold sections into and out of registration for casting and then removing cast articles. Vertical hydraulic actuators  27  and  29  move mold sections for registration during mold and/or for inspection and removal of mold sections from the casting machine. 
     The accessories module  24  is positioned and provided in the casting system  12  to perform desired operations on the cast article, preferably while the cast article is positioned within the cavities  108   a-d  of the casting module  20 . As shown in FIGS. 1-3, the accessories module  24  is positioned generally above the casting module  20 . The illustrated accessories module  24  includes a mount  140  and one or more suitable accessories  144   a-d  (shown in FIG.  4 ). The illustrated mount  140  is a rotary mount adaptable to support four accessories  144   a-d , although the mount  140  may support any suitable number of accessories. Nonlimiting examples of suitable accessories include a head setter, a ring setter, a strut setter, an unloader, a strainer, or a riser sleeve. The accessory may be any other suitable component. A servomotor  31  provides rotation of accessories in a horizontal plane, for example. Additional servomotors and/or hydraulic actuators are provided for the required positioning and operation of separate accessories. 
     The illustrated mount  140  includes four mount faces  148   a-d . The illustrated mount faces  148   a-d  are generally flat surfaces, although they may be formed as desired to accommodate the accessories. The mount faces  148   a-d  are preferably positioned at about 90 degrees with respect to each other, as indicated by the angle “C.” The mount faces  148   a-d  may also be positioned and configured for optimal positioning of the accessories  144   a-d . Likewise, each of the mount faces  148   a-d  may accommodate more than one accessory if desired. 
     In a preferred embodiment, the mount  140  of the accessories module  24  includes a pivot point  152 . The pivot point  152  is positioned approximately in the center of the mount  140 . The pivot point  152  is operative to allow the accessories  144   a-d  to be positioned with respect to the casting module  20  under control of the servomechanism. 
     The pivot point  152  of the mount  140  is useful to allow a series of operations to be performed with respect to one or more portions of the casting module  20 . For example, the pivot point  152  may position the strainer accessory generally directly above the casting module  20  to remove impurities from the fill material being provided to the fill inlets  116   a,b  of the casting module  20 . Continuing the example, mount  140  rotates about 90° to position the head setter accessory generally directly above the casting module  20  to create a desirable pattern on the cast articles located in the cavities  108   a-d  of the casting module  20 . Continuing further the example, mount  140  rotates another 90° to position the strut setter accessory generally directly above the casting module  20  to deposit a strut on the cast articles located in the cavities  108   a-d  of the casting module  20 . Concluding the example, mount  140  rotates another 90° to position the unloader accessory generally directly above the casting module  20  to unload the cast articles from casting module  20 . 
     Utility module  28  comprises an electronic control panel  160  and a valve panel  164 . Utility module  28  is spaced away from casting module  20  but is connected to it by a plurality of fluid lines and electrical lines. 
     Control panel  160  includes a programmable controller  41  connected to an interface panel  43  and an output driver  45 . Controller  41  is programmed according to each step of the desired casting process for the articles to be produced, including positioning of the mold sections, pouring of fill material, tilting of the casting module, cooling of the mold, opening of the mold sections, accessory operations, and removal of the finished article, for example. The process can also be controlled manually using push button controls on interface panel  43 . Output driver  45  generates command signals and/or direct drive signals for electrical actuators, such as servomotor  31 . 
     Valve panel  164  includes a plurality of electrically controlled valves  35  which are controlled by controller  41  through output driver  45 . Some of these are hydraulic valves connected to a source of pressurized hydraulic fluid (e.g., oil or air) to provide a supply of motive power for hydraulic actuators  25 ,  27 ,  29 , and  60 , for example. At least one valve is connected to a source of cooling fluid (e.g., water) for pumping through the casting module to aid in the solidification of the cast article. 
     By segregating the parts of a casting system into a casting module, accessories module, and utility module as described, it becomes feasible to increase the number of molds that may be placed in a single casting module. Thus, more cast articles can be produced in a smaller area, saving on capital investment. Furthermore, serviceability and packaging of each of the different parts are improved. Design, development, machine fabrication, and operation/maintenance costs are reduced as a result of the simplified structure. 
     In a further embodiment shown in FIG. 5, a single utility module  28  is shown operatively connected to four casting modules  20 , thereby achieving greater efficiencies and cost savings. Each illustrated casting module  20  is supported by a support structure module  16  and includes an accessories module  24 . Shared utility module  28  and the casting modules  20  form a cell. The cell configuration is advantageous for its additional savings in floor space and maximized use of the resources within utility module  28 . 
     The principle and mode of operation of this invention have been described in its preferred embodiments. However, it should be noted that this invention may be practiced otherwise than as specifically illustrated and described without departing from its scope.