Claims:WE CLAIM:
1. An automatic vent poking system (100) for sand molds (130) for making castings, comprising:
• a poking station;
• a conveyor (125) for conveying molds (130) to said poking station;
• a work-table on which a mold (130) conveyed by said conveyor (125) is laid and halted for poking the mold (130) and creating vents therein;
• a poking tool (305) fitted in a tool holder for performing the poking operation on the mold (130) halted on said work-table;
• a powering arrangement for reciprocating said tool holder along an operative Z-axis to perform the poking operation; and
• a control unit (160, 165) for operating servo motors and drives for displacing the poking tool (305) to predetermined locations in the operative X-Y plane for performing said poking operation at said predetermined locations by displacing the tool holder bearing said poking tool along the operative Z-axis at each of said locations.
2. The automatic vent poking system (100) as claimed in claim 1, wherein said powering arrangement for effecting the reciprocating movement of said tool holder is a pneumatic cylinder (335) controlled by any of said control unit (160, 165).
3. The automatic vent poking system (100) as claimed in claim 1, wherein said poking station comprises:
• a structure for supporting an X-axis guide (105) at each of the opposite edges of said structure;
• a plurality of columns (115) fixed onto a base (120) and a plurality of beams (140) mounted on the top said columns (115) which define said structure;
• a passage defined between said spaced apart columns (115) for said conveyor (125) wherein said conveyor (125) conveys said mold (130) at said poking station;
• a Y-axis unit (200) supported on said X-axis guides (105) in a lateral sliding configuration along the X-axis direction;
• a drive unit to move said Y-axis unit (200) laterally along the X-axis direction wherein each of the opposite ends of said Y-axis unit (200) is placed in a sliding configuration on said X-axis guides (105);
• a Z-axis unit (300) mounted in a sliding configuration on said Y-axis unit (200) wherein the movement of said Z-axis unit (300) along the operative Y-axis is effected by at least one servo motor (210) in cooperation with a gear box (215); and
• an induction motor (320) provided on said Z-axis unit (300) for driving said tool holder.
4. The automatic vent poking system (100) as claimed in claim 3, wherein said tool holder of said Z-axis unit (300) is a collet chuck (310).
5. The automatic vent poking system (100) as claimed in claim 3, wherein a plurality of doors (135) is provided alongside said structure for observation and operator safety.
6. The automatic vent poking system (100) as claimed in claim 3, wherein multiple servomotors and drives the movement of said Z-axis unit (300) along an operative X-Y plane is effected by.
7. The automatic vent poking system (100) as claimed in claim 3, wherein a linear motion rail (325) is provided for guiding the movement of said induction motor (320) along with said tool holder along the operative Z-axis.
8. The automatic vent poking system (100) as claimed in claim 3, wherein a plurality of drag chains (220, 330) is provided to protect electrical cables and pneumatic hoses.
9. The automatic vent poking system (100) as claimed in claim 8, wherein a first drag chain (220) is configured on said Y-axis unit (200) and a second drag chain (330) is configured on said Z-axis unit (300).
10. The automatic vent poking system (100) as claimed in claim 3, wherein a rack is provided on said Y-axis unit (200) which engages with the pinion of said gear box (215) for effecting the movement of said Z-axis unit (300) along the operative Y-axis direction.
11. The automatic vent poking system (100) as claimed in claim 1, said control unit (160, 165) is provided with a display and a human machine interface (HMI) for manipulating the operational parameters of said automatic vent poking system (100).
12. The automatic vent poking system (100) as claimed in claims 1, 2, and 3, said control unit (160, 165) is configured for controlling the movement, co-ordinates and operation of said poking tool (305) by giving control signals to said servo motors and drives, said induction motor (320), and said pneumatic cylinder (335).
13. The automatic vent poking system (100) as claimed in claims 1, said control unit (160, 165) is provided with a repository to store different sets of vent poking operations and co-ordinates.
14. The automatic vent poking system (100) as claimed in claims 1, said control unit (160, 165) is provided with an arrangement for receiving new and updated set of instructions and vent coordinates according to the mold design.
15. The automatic vent poking system (100) as claimed in any of the preceding claims, wherein a plurality of sensor are provided at predetermined locations for effective monitoring and safety of said automatic vent poking system (100) and the human operators operating the same.
16. The automatic vent poking system (100) as claimed in claim 15, wherein said sensors are selected from the group consisting of a pressure sensor, a proximity sensor, a limit switch, and a speed sensor.
17. The automatic vent poking system (100) as claimed in any of the preceding claims, wherein a sliding movement between any components is facilitated by a linear motion rails and a linear motion blocks provided at suitable locations.
18. A method of poking vents on sand molds (130) by an automatic vent poking system (100), said method comprising the following steps:
• conveying a mold (130), by a conveyor (125), to a poking station;
• holding said mold (130) on a work-table of said poking station for performing poking operation on said mold (130);
• manually selecting the control parameters of said system (100), which include a set of predetermined position coordinates where vents are to be poked on said mold (130) via control unit (160, 165) in accordance with the design and type of mold (130);
• displacing a Z-axis unit (300) carrying a poking tool (305) in a tool holder along an operative X-Y plane to a predetermined position coordinates by operating a plurality servo motors and drives;
• operating a powering arrangement for performing the poking operation by displacing the tool holder bearing said poking tool (305) along the operative Z-axis at each of said predetermined locations to poke vents on said mold (130) at said predetermined locations; and
• conveying said mold (130) with poked vents out from said poking station.
19. The method of poking vents on a sand mold (130) as claimed in claim 18, wherein said powering arrangement is a pneumatic cylinder (335).
20. The automatic vent poking system (100) as claimed in claim 1 and 18, wherein said conveyor (125) and said mold (130) is part of a high-pressure molding line.
, Description:FIELD
The present disclosure relates to the production of molds.
DEFINITION
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicate otherwise.
Diesel Effect - The expression ‘Diesel Effect’ used hereinafter in this specification refers to, abrasion and corrosion of mold material due to trapped gases.
Poking vent - The expression ‘poking vent’ used hereinafter in this specification refers to the method of forming holes or vents on the molds.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
It is essential to release hot gases when a hot metal is poured into a mold. The hot gases get trapped inside the mold due to insufficient venting channels/outlets. During a casting process, when a hot molten metal is poured into the mold, hot and pressurized gases released in the mold need a way to escape to the surrounding. Failure to do so will result in entrapment of these gases, resulting in the formation of cavities or blow-hole defects in the casted parts. A combined effect of the molten metal pressure and high temperature causes the “diesel effect”, which results in burns (carbonization), gloss marks, and cracks in casted parts.
Conventionally, the vents are made in the form of holes in the molds by hand held tools such as a drilling machine, a punching machine, and the like. However, the conventional method of forming/poking vents in the molds is crude and significantly dependent on the experience and skill of an operator. This method is thus time consuming and cumbersome and not capable of being implemented in mass production of molds. Further, there are a number of quality and consistency issues arising due to non-uniformity and excessive handling of the molds.
Therefore, there is felt a need of an automatic vent poking system for molds that alleviates the above-mentioned drawbacks.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide an automated vent poking system for forming/poking holes in a mold.
Another object of the present disclosure is to provide an automated vent poking system that facilitates easy and faster drilling of holes for poking vents in a mold.
Another object of the present disclosure is to provide an automated vent poking system that reduces the variation in the vent holes formed in molds.
Another object of the present disclosure is to provide an automated vent poking system that reduces the dependability on skilled operators.
Yet another object of the present disclosure is to provide an automated vent poking system that improves the quality and reliability of the molds thus produced.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.

SUMMARY
The present disclosure envisages an automatic vent poking system for sand molds. The automatic vent poking system facilitates accurate positioning of vent holes of the molds. The automatic vent poking system for sand molds comprises a poking station which receives a conveyor for conveying a mold to the poking station. A work-table is provided in the poking station for positioning the mold at the poking station where vents are poked on the mold. A poking tool is fitted in a tool holder for performing the vent poking operation on the mold which is halted on the work-table. A control unit is provided for operating servo motors and drives for displacing the tool holder and the tool to predetermined locations in an operative X-Y plane where vents are to be poked on the mold. A powering arrangement is provided for enabling the reciprocating movement of the tool held in the holder along an operative Z-axis for performing the poking operation on the mold. The reciprocating movement of the tool is effected at each predetermined position in the X-Y plane to enable multiple vents on the mold at predetermined positions.
The powering arrangement for effecting the reciprocating movement of the tool holder is a pneumatic cylinder which is controlled by a control unit.
The present disclosure further envisages a automatic vent poking system which comprises a structure for supporting an X-axis guide at each of the opposite edges of said structure, a plurality of columns fixed onto a base and a plurality of beams mounted thereon to form the structure, a passage defined between the spaced apart columns for the conveyor wherein the conveyor conveys the mold to the poking station, a Y-axis unit supported on the X-axis guides such that the Y-axis unit can slide laterally along the operative X-axis direction, a drive unit for moving the Y-axis unit laterally along the X-axis direction wherein each of the opposite ends of the Y-axis unit is placed in a sliding configuration on the X-axis guides, a Z-axis unit mounted in a sliding configuration on the Y-axis unit wherein the movement of the Z-axis unit along the operative Y-axis is effected by at least one servo motor in cooperation with a gear box; and an induction motor provided on the Z-axis unit for driving the tool holder which further drives the poking tool. The tool holder is a collet chuck.
In another embodiment, the poking station is provided with a plurality of doors alongside the structure for observation and operator safety.
In yet another embodiment, linear motion rail is provided for guiding the movement of the induction motor along with the tool holder along the operative Z-axis. Drag chains are provided to protect electrical cables and pneumatic hoses used in the system.
In another embodiment, a rack is provided on the Y-axis unit which engages with the pinion of the gear box for effecting the movement of the Z-axis unit along the operative Y-axis direction.
In another embodiment, the control unit is provided with a display and a human machine interface (HMI) for manipulating the operational parameters of the automatic vent poking system. The control unit is also configured for controlling the movement, co-ordinates and operation of the Z-axis unit and the poking tool.
In another embodiment, the automatic vent poking system is provided with a plurality of sensor at predetermined locations for effective monitoring and safety of the automatic vent poking system and the human operators operating the same. The sensors are selected from the group consisting of a pressure sensor, a proximity sensor, a limit switch, and a speed sensor.
In another embodiment, sliding movement between any components is facilitated by a linear motion rails and a linear motion blocks provided at suitable locations.
The present disclosure further envisages a method of poking vents on molds by using the automatic vent poking system. In accordance with the method, the mold is conveyed by the conveyor to a poking station wherein the mold is held and positioned on a work-table by stopping the conveyor. The control units are used to manually select the control parameters of the automatic poking system which include a set of predetermined position coordinates where vents are to be poked on the mold. These parameters are selected in accordance with the design and type of mold positioned on the work-table of the poking station. The control unit operates the servomotors and drives to displace the Z-axis unit along the operative X-Y plane to a predetermined position coordinates. The Z-axis unit carries the poking tool in the tool holder. A powering arrangement is operated by the control units to displace the tool holder bearing the poking tool along the operative Z-axis at each of the predetermined locations to poke vents on the mold at the predetermined locations. Once the vents are poked on the mold, the mold is conveyed by the conveyor out of said poking station.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
An automatic vent poking system for sand molds, of the present disclosure, will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates an isometric view of an automated vent poking system;
Figure 2 illustrates an isometric view of a structure for supporting X-axis guides and Y-axis unit to form a Cartesian robotic unit;
Figure 3 illustrates an isometric view of a Y-axis unit;
Figure 4 illustrates an isometric view of a Z-axis unit;
Figure 5 illustrates a schematic side view of the Z-axis unit of Figure 4;
Figure 6 illustrates a block diagram of the automatic vent poking system of Figure 1; and
Figure 7 illustrates a sectional view of a mold with a vent, a riser, and a filler neck formed thereon.
LIST OF REFERENCE NUMERALS
100 – Automatic vent poking system
102 - Structure frame
105 – X-axis guides
106 – Y-axis guide
115 - Columns
120 – Base
125 – Conveyor
130 – Mold
132 - Vent
133 – Filler neck
134 - Riser
135 – Doors
140 – Beams
150 - Linear motion (LM) rail
160 - Control unit
165 - Control unit
200 - Y-axis unit
205 - Y-beam
210 - Servo motors
215 - Gear box
220 – Drag chain
300 - Z-axis unit
305 – Poking tool
310 - Collet chuck
315 - Tool guiding bracket
320 - Induction motor
325 – Linear motion (LM) rail
330 – Drag chain
335 – Pneumatic cylinder
340 – Tool drive assembly

DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms “comprises”, “comprising”, “including” and “having” are open-ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
When an element is referred to as being “mounted on”, “engaged to”, “connected to” or “coupled to” another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Terms such as “inner”, “outer”, “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.
Figure 1 and Figure 2 illustrates an isometric view of an automatic vent poking system 100 consisting of a structure frame 102 for supporting X-axis guides and Y-axis unit to form a Cartesian robotic unit, wherein the movement of poking tool along an operative X-Y plane is effected with servo motor & drives.
The automatic vent poking system 100 comprises the structure frame 102 formed of a plurality of columns 115 and beams 140 assembled together. A poking station having a work-table is defined in the system 100 where the actual poking operation takes place. The structure frame 102 is fixed on a base 120. Two X-axis guides 105 and a Y-axis guide 106 facilitate the movement of a Z-axis unit 300 (shown in figure 4) along with the poking tool 305 attached thereon in the operative X-Y plane. The X-axis guides 105 are mounted on opposite edges of the structure frame 102. A moving carriage on each of the X axis guides 105 forms the base for the Y-axis guides 106. Linear motion (LM) rails 150 are provided beside each X-axis guide 105. The moving carriages on the X-axis guides 105 are configured to slide on the linear motion (LM) rails 150 along with linear motion (LM) blocks. A conveyer 125 is provided for conveying a mold 130 to the poking station. The above mentioned poking system 100 can also be used with a high-pressure molding line, wherein the conveyor 125 and the mold 130 form an integral part of the high-pressure molding line.
Numerous electrical cables are used to supply power to servo motors 210 and drives (not shown specifically). Multiple pneumatic hoses are also used for supplying pressurized fluid to pneumatic cylinder 335 (shown in figure 4). Drag chains (220, 330) are used to surround and guide the electrical cables and the pneumatic hoses connected to the moving components of the system 100. The drag chains (220 & 330) protect and reduce the wear and stress on the electrical cables and the hoses, prevent entanglement, and ensures operator safety. Control units 160 and 165 are provided alongside the columns 115 for controlling various operations of the system 100. The movement of poking tool 305 (shown in figure 4) along the operative X-Y plane is enabled with servo motor & drives.
According to an embodiment of the present disclosure, the control units 160 and 165 include a programmable logic controller (PLC) or a programmable controller board of industrial grade to provide data processing capabilities in the system 100. The control units (160 & 165) are provided with a human machine interface (HMI) for data input and changing operational parameters. Data input may be achieved through a touch screen, buttons, a keypad, a joystick, a USB port, or a data cable. The control units are provided with internal storage arrangement such as a repository/memory for storing various settings and a predetermined vent poking coordinates in accordance with the design of the mold 130 which is positioned or halted in the poking station. The repository is of re-writable type to update the designs and programs for carrying out vent poking operation for any new type of mold 130.
After the mold 130 is conveyed by the conveyer 125 to the poking station it is laid and halted on the work-table where vent poking operation in the mold 130 is performed. Thereafter, the operator selects the predefined settings, parameters, and vent co-ordinates through the control units (160 & 165) where vents are to be poked in the mold. A smart mode of operation is also provided in the vent poking system 100. The above mentioned predefined settings, parameters, and vent co-ordinates are automatically selected when the poking system 100 is operating in the smart mode. These settings are different for each mold 130 design. The control units (160 & 165) provide signal to the servo motors and drives to displace the poking tool 305 at predetermined locations where vents are to be poked. Thereafter, the pneumatic cylinder is operated to displace the Z-axis unit 300 housing the poking tool 305 in the operative Z-axis such that vents 132 are formed in the mold 130 at desired locations. The conveyer 125 is then powered to carry the vented mold 130 away from the poking station such that a new mold 130 can be laid on the work-table for vent poking operation.
Figure 3 illustrates a Y-axis unit 200. The movement of the Z-axis unit 300 along the operative Y-axis is effected by at least one servo motor 210 in combination of a gear box 215. The gear box 215 enables the Y-axis movement via a rack and pinion arrangement. The rack is fixed to a Y-beam 205 while the pinion moves along with the servo motor 210 and the Z-axis unit 300. The Z-axis unit 300 houses a tool post for the poking tool 305. The tool post houses the poking tool 305 for poking of vents in the mold 130. The ends of the Y-beam 205 are sliding along the LM rails 150 of the X-axis guides 105. The servo motors 210 are controlled via signals received from any of the control unit (160,165) mentioned earlier.
Figure 4 illustrates a Z-axis unit 300 which is slidably mounted on the Y-axis unit 200 of Figure 3. The Z-axis unit 300 includes the tool 305, a collet chuck 310, a tool guiding bracket 315, an induction motor 320, LM rails 325, a drag chain 330, and the pneumatic cylinder 335. The poking tool 305 held in the collet chuck 310 is a rotating tool driven by the high speed induction motor 320. The operation of the induction motor 320 is controlled through signal received via flexible cables from the control units (160 & 165). An induction motor mounting bracket, the collet chuck 310, and the tool guiding bracket 315 together form a tool-drive assembly 340. The tool-drive assembly 340 slides linearly along the LM rails 325 wherein the linear motion is effected by the pneumatic cylinder 335. The pneumatic cylinder is powered by pressured air/gas received via flexible hoses. The electric cables and pneumatic hoses are protected by drag chains (220 & 330). The operation, speed and frequency of operation of the poking tool 305 are controlled through signals received from any of the control units (160, 165). The path followed by the Z-axis unit 300 and the operation of the tool 305 is a function of the design and orientation of the molds 130 positioned at the poking station.
According to an embodiment of the present disclosure, a plurality of sensors such as a speed sensor, pressure sensor, proximity sensor and limit switches are used in combination for advanced safety of the system 100 and the operators. The signal from the sensors and the limit switches are sent to each of the control units (160, 165) where corrective actions and decisions are taken.
According to an embodiment of the present disclosure, the operation of the system is controlled through a remote server. Further, cloud computing and Internet of Things (IOT) configurations is also utilized in more sophisticated and complex systems. The complete process is automated to meet higher production volume of the vented molds 130.
The X-Y coordinate axes and servo motors and drives are used for moving the tool 305 with respect to the coordinates of vents in mold, with reference to Zero (home position). The different mold vent co-ordinates are stored in the memory of the control units. The reference Zero-point is auto updated as per the design of mold 130 at the work-table.
Doors 135 are provided alongside the system to facilitate observation and maintenance operation. Further, the doors 135 also function as a protective shield to protect the operators from debris flying from inside the automatic vent poking system 100.
Figure 5 illustrates the side view of the Z-axis where the tool 305, collet chuck 310, the gear box 215, the induction motor 320, and the pneumatic cylinder 335 are shown. Further, a rack is also shown in an inverted configuration.
In according to an embodiment of the present disclosure, the operations of the various components of the automatic vent poking system are controlled by separate control units 160 and 165 which further communicate with each other. This exemplary control strategy is illustrated by a block diagram of the automatic vent poking system of Figure 6.
Figure 7 illustrates an isometric view of an exemplary mold with vents formed thereon. The vent 132 is formed at a specific location on the mold 130. Filler neck 133 for pouring molten metal and a riser 134 is provided into the mold 130 for casting a part.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of an automated vent poking system that:
• facilitates easy and fast drilling of holes for venting;
• reduces the dependability on laborers;
• increases the quality and reliability of the vented molds produced;
• can be used for effective venting of high pressure molds; and
• reduces the cost of each vented mold.
The foregoing disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.