Description:BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION
[0001] The present invention relates to machines and machine tools, and in particular, relates to a machining system for sharpening and lapping of three-angle inserts used in valve seat and guide machining.

DESCRIPTION OF THE PRIOR ART
[0002] It is known that valve seat and guide machines have been crucial components in machining and reconditioning of an internal combustion (IC) engine. Tool inserts such as three-angle inserts are used to machine and recondition the IC engine. The three-angle inserts are cutting tools designed to create a three-angled profile on a valve seat for proper valve sealing and engine performance. The three-angle inserts are used to cut three distinct angles on a surface of the valve seat. The three-angle inserts typically include a seat or primary angle (about 45 degrees), a top angle (about 30 degrees) and a bottom angle (about 60 degrees). Further, the three-angle insert includes a zero rake angle i.e., the cutting face perpendicular to the valve seat surface being machined.
[0003] Typically, the valve seat and guide machines require a separate sharpening device and a lapping device for sharpening and lapping the three angle inserts. SerdiTM introduced a first sharpening device to sharpen the insert. The sharpening device offered by SerdiTM included a 400 grit diamond wheel to sharpen the section of the insert. Although the sharpening device is useful, it posed several problems. For example, the sharpening device only sharpens a section of the insert which is enough to sharpen the needed cutting edge. Further, sharpening creates a very rough surface, leading to surface imperfections or poor finish on machined valve seats. In addition, while aligning the insert against the diamond sharpening wheel, an operator has to guess and align against the face of the diamond sharpening wheel. This imprecise alignment can result in an incorrect rake angle, either too negative or excessively positive. The negative rake angle increases the cutting load, which can cause seat geometry issues such as out-of-roundness and poor finish. Conversely, the large positive rake angle reduces the lifespan of the cutting edge.
[0004] Further, a separate lapping device is used to perform a lapping operation on the insert. For example, the applicant of the present invention introduced an insert lapping device in the past to perform a lapping operation on the insert. The insert lapping device presents a large 600 grit diamond wheel and a rod extending from a housing. The insert lapping device encompasses an insert holder having a single hole allowing an insert at the insert holder to be placed precisely against a 600 grit diamond wheel. With this, the operator is able to get a lapped finish on the top surface of the insert. The insert lapping device helps to maintain perfect zero rake angle and enhances the life of the cutting edge and lapped finish, which in turn contributes to better surface finish and better cutting of hard valve seats. Although the insert lapping device allowed the operators to achieve a finely lapped finish on the top surface of the insert and maintaining a perfect zero rake angle, the lapping process takes a considerable amount of time, particularly when dealing with worn or chipped insert edges. Further, the insert lapping device is limited to only lapping and cannot be used for sharpening the insert.
[0005] Therefore, there is a need in art to provide an improved machining system that eliminates the shortcomings of previous designs, offers both sharpening and lapping operations in a single insert lapping device setting, and provides efficient sharpening and high-quality finishing/lapping of three-angle inserts used in valve seat and guide machining.

SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a machining system capable of performing both sharpening and lapping operations on a three-angle insert used in valve seat machining.
[0007] It is another object of the present invention to provide a dual wheel system having different grits for performing sharpening and lapping operations on an insert.
[0008] It is another object of the present invention to provide an insert holder capable of accommodating different insert types and having a plurality of grooves for easy transition between sharpening and lapping operations.
[0009] In order to achieve one or more objects, the present invention provides a machining system for sharpening and lapping an insert used in valve seat and guide machining. In one example, the machining system includes a valve seat and guide cutting machine. The machining system includes an insert sharpening and lapping device. The insert sharpening and lapping device includes a housing having a smaller first grit wheel and a larger second grit wheel. The first grit wheel is a 400 grit diamond sharpening wheel and the second grit wheel is a 600 grit diamond lapping wheel. The first grit wheel has a smaller diameter than the second grit wheel. Further, the first grit wheel positions above the second grit wheel.
[0010] The machining system includes a rod extending from the housing. The machining system includes an insert holder removably connecting to the rod. The insert holder includes an insert. The insert holder includes a plurality of grooves positioned one above another for receiving the rod at various positions. A first groove of the plurality of grooves receives the rod such that the insert positions against the first grit wheel in operation to sharpen the entire face of the insert. A second groove of the plurality of grooves receives the rod such that the insert positions against the second grit wheel in operation to lap the insert.
[0011] In one advantageous feature of the present invention, the machining system addresses the limitations of existing separate sharpening and lapping tools by combining both processes in a single system (i.e., insert sharpening and lapping device).
[0012] In another advantageous feature of the present invention, the machining system offers a dual wheel system whereby a smaller 400-grit wheel positions above a larger 600-grit wheel. The 400-grit wheel serves as the sharpening tool, capable of providing a surface finish of 0.6-0.8 Ra micro-meters (µm). The 400-grit wheel ensures that the entire face of the insert is sharpened while maintaining a perfect zero rake angle. The 600-grit wheel functions as the lapping tool and helps to achieve a finer surface finish of 0.2-0.4 Ra (µm).
[0013] In yet another advantageous feature of the present invention, the insert holder includes a plurality of grooves that allow it to be positioned precisely against one of the smaller 400-grit wheel and the larger 600-grit wheel. This design enables precise and faster transitions between sharpening and lapping operations.
[0014] These and other objects of the present invention will be apparent from review of the following specification and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is an environment of a machining system such as a valve seat and guide cutting machine implements, in accordance with one exemplary embodiment of the present invention.
[0016] FIG. 2A is an enlarged front view of the machining system having a sharpening and lapping device, in accordance with one exemplary embodiment of the present invention.
[0017] FIG. 2B shows a user operating the sharpening and lapping device in accordance with one exemplary embodiment of the present invention.
[0018] FIG. 3 shows a perspective view of the machining system having the sharpening and lapping device in accordance with one exemplary embodiment of the present invention.
[0019] FIG. 4A and FIG. 4B show a top perspective view and a bottom perspective view, respectively of an insert holder, in accordance with one embodiment of the present invention.
[0020] FIG. 5 is an operational view of the machining system in which the insert holder is placed against a first grit wheel i.e., 400 grit diamond wheel, in accordance with one exemplary embodiment of the present invention.
[0021] FIG. 6 is an operational view of the machining system in which the insert holder is placed against a second grit wheel i.e., 600 grit diamond wheel, in accordance with one exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] The detailed description set forth below in connection with the appended drawings is intended as a description of exemplary embodiments in which the presently disclosed invention may be practiced. The term “exemplary” used throughout this description means “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other embodiments. The detailed description includes specific details for providing a thorough understanding of the presently disclosed machining system. However, it will be apparent to those skilled in the art that the presently disclosed invention may be practiced without these specific details. In some instances, well-known structures and devices are shown in functional or conceptual diagram form in order to avoid obscuring the concepts of the presently disclosed machining system.
[0023] In the present specification, an embodiment showing a singular component should not be considered limiting. Rather, the invention preferably encompasses other embodiments including a plurality of the same component, and vice-versa, unless explicitly stated otherwise herein. Moreover, the applicant does not intend for any term in the specification to be ascribed an uncommon or special meaning unless explicitly set forth as such. Further, the present invention encompasses present and future known equivalents to the known components referred to herein by way of illustration.
[0024] Although the present invention describes a machining system, it is to be further understood that numerous changes may arise in the details of the embodiments of the machining system. It is contemplated that all such changes and additional embodiments are within the spirit and true scope of this invention.
[0025] The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. As used herein, the word “exemplary” or “illustrative” means “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” or “illustrative” is not necessarily to be construed as preferred or advantageous over other implementations. All of the implementations described below are exemplary implementations provided to enable persons skilled in the art to make or use the embodiments of the invention and are not intended to limit the scope of the invention.
[0026] Various features and embodiments of a machining system for sharpening and lapping an insert are explained in conjunction with the description of FIGUREs (FIGs) 1-6.
[0027] FIG. 1 shows an environment 10 of a machining system 12, in accordance with one exemplary embodiment of the present invention. Machining system 12 indicates a valve seat and guide cutting machine having a “sharpening and lapping fixture” for sharpening and lapping an insert 80. Machining system 12 includes a fixture 13. Further, machining system 12 includes a machining head 16 connected via a frame 20. Frame 20 encompasses an insert sharpening and lapping device 22 at one side, as can be seen from FIG. 1. FIG. 2A shows an enlarged view of machining system 12 in which a user 14 holds an insert holder 60 having insert 80 and places insert 80 against a dual grit diamond wheel system 38 for sharpening and lapping insert 80. FIG. 2B shows a (partial) perspective view of machining system 12, in accordance with one exemplary embodiment of the present invention. Insert sharpening and lapping device 22 includes a housing 24. Housing 24 indicates a container-like structure holding electronic, electrical and mechanical components required to operate insert sharpening and lapping device 22. In one example, insert sharpening and lapping device 22 includes one or more toggles (not shown) operated by hand or foot of user 14.
[0028] Housing 24 presents a rod 30. Rod 30 extends from the surface of housing 24, as can be seen from FIG. 3. Rod 30 includes a cylindrical section 32 and a tip 34. In one example, cylindrical section 32 takes a substantial length of rod 30. Tip 34 includes a tapered tip or angled tip depending on the need. Further, housing 24 encompasses a dual grit diamond wheel system 38 or simply dual wheel system 38. Dual wheel system 38 encompasses a first grit wheel 40 and a second grit wheel 42. As can be seen, first grit wheel 40 positions above second grit wheel 42. Further, first grit wheel 40 is smaller in size than second grit wheel 42. In other words, second grit wheel 42 has a larger diameter than first grit wheel 40. In accordance with the present invention, first grit wheel 40 includes a 400 grit diamond wheel or 400 grit diamond sharpening wheel. In one example, first grit wheel 40 has a fine and rough grit surface. The presently disclosed first grit wheel 40 is capable of providing a surface finish of 0.6-0.8 Ra (µm), where Ra indicates roughness average (or center line average) measured in micrometers (µm). Further, second grit wheel 42 includes a 600 grit diamond wheel or 600 grit diamond lapping wheel. In one example, second grit wheel 42 has a fine grit surface. The presently disclosed second grit wheel 42 is capable of providing a surface finish of 0.2-0.4 Ra (µm).
[0029] In one example, each of first grit wheel 40 and second grit wheel 42 is operated individually by motors (not shown) placed in housing 24. Optionally, a single motor (not shown) is used to operate both first grit wheel 40 and second grit wheel 42 simultaneously. When operated, each of first grit wheel 40 and second grit wheel 42 rotates in a clockwise direction or an anticlockwise direction. For ease of reference, FIG. 3 presents an arrow 44 to show that each of first grit wheel 40 and second grit wheel 42 rotates in the clockwise direction. A person skilled in the understands that it is possible to configure each of first grit wheel 40 and second grit wheel 42 to rotate in the anticlockwise direction without departing from the scope of the present invention. In one implementation, insert sharpening and lapping device 22 includes a cover 50 at the top of housing 24 for preventing chipped material to fly away from insert sharpening and lapping device 22 and cause injury to user 14.
[0030] Further, insert sharpening and lapping device 22 includes an insert holder 60. FIG. 4A and FIG. 4B show a top perspective view and a bottom perspective view, respectively of insert holder 60. Insert holder 60 includes a body 62 having an elongated structure. Body 62 presents a first end 64 and a second end 66. . First end 64 indicates a top side and second end 66 indicates a bottom side, or vice versa. In accordance with the present invention, insert holder 60 includes a first groove 68 and a second groove 70. Each of first groove 68 and second groove 70 comes in a circular configuration and extends through body 62, i.e., from first end 64 to second end 66. As can be seen, first groove 68 positions at the bottom of body 62 and second groove 70 positions above first groove 68. Further, body 62 includes a third groove 72 and a plurality of fourth grooves 74. In one example, fourth grooves 74 receive connectors 76. Further, body 62 includes an insert receiving section 78 at second end 66, as can be seen from FIG. 4B. Insert receiving section 78 is carved out to receive insert 80 of various shapes and sizes. In one example, insert 80 includes a three-angle insert used for creating a three-angled profile on a valve seat (not shown) for proper valve sealing and engine performance. A person skilled in the art understands that insert 80 includes any existing insert or specifically designed insert depending on the need. In one example, insert 80 connects to body 62 via connecting pin 82, as shown in FIG. 4B.
[0031] Now referring to FIG. 5 and FIG. 6, the operation of insert sharpening and lapping device 22 for sharpening and lapping insert 80 is explained, in accordance with one exemplary embodiment of the present invention. FIG. 5 shows the feature of sharpening insert 80. Here, insert holder 60 is removably connected to rod 30. Specifically, user 14 holds insert holder 60 and pushes insert holder 60 such that rod 30 passes and extends through first groove 68. Here, insert 80 at second end 66 of insert holder 60 is made to position/align against first grit wheel 40, as shown in FIG. 5. At this point, first grit wheel 40 is made to rotate in the direction 44 and user 14 presses insert holder 60 against first grit wheel 40. Insert 80 comes in contact with rotating first grit wheel 40 which sharpens insert 80. In the present invention, the rotating first grit wheel 40 sharpens the entire face of insert 80 maintaining perfect zero rake angle.
[0032] Subsequently, user 14 removes insert holder 60 from rod 30 connecting via first groove 68, and pushes insert holder 60 such that rod 30 passes and extends through second groove 70. Here, insert 80 at second end 66 of insert holder 60 is made to position/align against larger second grit wheel 42, as shown in FIG. 6. At this point, second grit wheel 42 is made to rotate in the direction 44 and user 14 presses insert holder 60 against second grit wheel 42. Insert 80 comes in contact with rotating second grit wheel 42 and allows to perform a lapping process on insert 80 using larger second grit wheel 42.
[0033] The dual wheel system 38 and insert holder 60 allow to perform sharpening operation on the entire face of insert 80 using first grit wheel 40 while maintaining perfect zero rake angle, and then followed by the lapping process using larger second grit wheel 42. The presently disclosed design solves the shortcomings of the sharpening device offered by SerdiTM and the insert lapping device offered by the present Applicant in the past by combining them both operations in a unique way.
[0034] The presently disclosed machining system provides several advantages over prior art. The machining system combines both sharpening and lapping devices in a single system with the help of dual wheel system. This eliminates the need for separate devices and saves time while reducing the complexity of operations. The dual wheel system having the smaller 400-grit diamond wheel allows for precise sharpening of the entire face of the insert while maintaining a perfect zero rake angle. This ensures a consistently sharp cutting edge, which enhances the performance and longevity of the insert. Further, the dual wheel system having the larger 600-grit diamond wheel provides a high-quality lapping finish. Further, the machining system includes an insert holder having two grooves that allows to precisely align/position the insert against the dual wheel system. The grooves and the rod allow the insert to be aligned/positioned against the wheels which ensures repeatable alignment of the insert.
[0035] A person skilled in the art appreciates that the machining system can come in a variety of shapes and sizes depending on the need. Further, many changes in the design and placement of components may take place without deviating from the scope of the presently disclosed machining system.
[0036] In the above description, numerous specific details are set forth such as examples of some embodiments, specific components, devices, methods, in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to a person of ordinary skill in the art that these specific details need not be employed, and should not be construed to limit the scope of the invention.
[0037] In the development of any actual implementation, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints. Such a development effort might be complex and time-consuming, but may nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill. Hence as various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
[0038] The foregoing description of embodiments is provided to enable any person skilled in the art to make and use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the novel principles and invention disclosed herein may be applied to other embodiments without the use of the innovative faculty. It is contemplated that additional embodiments are within the spirit and true scope of the disclosed invention.
, Claims:I/WE CLAIM:

1. A machining system for sharpening and lapping a valve seat insert, said machining system comprising:
a housing having a first grit wheel and a second grit wheel;
a rod extending from said housing, wherein said rod positions below said first grit wheel and said second grit wheel; and
an insert holder removably connecting to said rod at various positions, wherein said insert holder comprising an insert,
wherein said insert positions against said first grit wheel in operation to sharpen the entire face of said insert using said first grit wheel, followed by repositioning of said insert holder in order to position said insert against said second grit wheel in operation to lap said insert using said second grit wheel.

2. The machining system of claim 1, wherein said first grit wheel has a smaller diameter than said second grit wheel.

3. The machining system of claim 1, wherein said first grit wheel is a 400 grit diamond wheel.

4. The machining system of claim 3, wherein said second grit wheel is a 600 grit diamond wheel.

5. The machining system of claim 1, wherein each of said first grit wheel and said second grit wheel operatively connects to a motor and configures to rotate in a clockwise direction.

6. The machining system of claim 1, further comprises a cover at the top of said housing to prevent chipped material from flying away.

7. The machining system of claim 1, wherein said insert holder comprises a first groove and a second groove, wherein said first groove positions at the bottom of said insert holder, and wherein said second groove positions above said first groove.

8. The machining system of claim 7, wherein said insert holder connects to said rod via said first groove to position said insert against said first grit wheel to sharpen the entire face of said insert.

9. The machining system of claim 7, wherein said insert holder connects to said rod via said second groove to position against said second grit wheel to lap said insert.

10. A machining system for sharpening and lapping a valve seat insert, said machining system comprising:
a housing having a first grit wheel and a second grit wheel;
a rod extending from said housing, wherein said rod positions below said first grit wheel and said second grit wheel; and
an insert holder comprising an insert, wherein said insert holder comprises a plurality of grooves positioned one above another for receiving said rod at various positions,
wherein a first groove of said plurality of grooves receives said rod such that said insert positions against said first grit wheel in operation to sharpen the entire face of said insert, and
wherein a second groove of said plurality of grooves receives said rod such that said insert positions against said second grit wheel in operation to lap said insert.

11. The machining system of claim 10, wherein said first grit wheel has a smaller diameter than said second grit wheel.

12. The machining system of claim 10, wherein said first grit wheel is a 400 grit diamond wheel.

13. The machining system of claim 12, wherein said second grit wheel is a 600 grit diamond wheel.

14. The machining system of claim 10, wherein each of said first grit wheel and said second grit wheel operatively connects to a motor and configures to rotate in a clockwise direction.

15. A method of sharpening and lapping a valve seat insert, said method comprising the steps of:
providing a housing having a first grit wheel and a second grit wheel;
providing a rod extending from said housing, said rod positioning below said first grit wheel and said second grit wheel;
providing an insert holder removably connecting to said rod at various positions, said insert holder comprising an insert;
positioning said insert holder on said rod for aligning said insert against said first grit wheel in operation to sharpen the entire face of said insert using said first grit wheel; and
repositioning said insert holder on said rod for aligning said insert against said second grit wheel to lap said insert.

16. The method of claim 15, further comprising providing said first grit wheel with a 400 grit diamond wheel.

17. The method of claim 15, further comprising providing said second grit wheel with a 600 grit diamond wheel.

18. The method of claim 15, further comprising providing a motor for rotating each of said first grit wheel and said second grit wheel for performing sharpening and lapping operations on said insert.

19. The method of claim 15, further comprising providing a first groove and a second groove at said insert holder, said first groove positioning at the bottom of said insert holder and said second groove positioning above said first groove.

20. The method of claim 19, further comprising:
connecting said insert holder to said rod via said first groove for positioning said insert against said first grit wheel for sharpening the entire face of said insert; and
reconnecting said insert holder to said rod via said second groove for positioning said insert against said second grit wheel for lapping said insert.