Description:FIELD
The present disclosure relates to a mechanism for oscillating a tool holder in a superfinishing operation. More particularly, relates to an oscillating unit for superfinishing operations with abrasive stone.
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 indicates otherwise.
SUPERFINISHING: The term “SUPERFINISHING” refers to a metalworking process used to enhance the surface finish and geometry of workpieces. It aims to achieve a finished surface by removing the thin amorphous layer left by previous machining processes. Unlike polishing, which results in a mirror-like finish, superfinishing creates a cross-hatch pattern on the workpiece.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
A typical superfinishing mechanism uses a motor with a connecting link to provide the rocking angular oscillation movement of the tool holder. Some standard oscillating unit converts a linear oscillation movement into an angular oscillation movement with the help of profiled plates for the surface finishing operation. However, such an oscillation mechanism generates a huge vibration and noise. Also, the angle adjustment for finishing operation is difficult, as such oscillations unit’s amplitude of oscillation modification or adjustment is critical and inaccurate.
In another conventional oscillation unit, a specially manufactured reversing servo motor is used which rotates clockwise and anticlockwise and provides direct drive to the stone holder. However, such an oscillation unit requires a setup change with new parts to modify the amplitude of oscillation.
Yet another existing oscillation unit requires additional maintenance and continuous adjustment and setup of parts due to its complex structure and a greater number of mechanical parts. Therefore, a precise adjustment of amplitude is not possible. Further, to make a variation in the raceway width, a new tool or tool holder is required, which is difficult, time-consuming and expensive.
Therefore, there is felt a need to provide a mechanism for oscillating a tool holder in a superfinishing operation, that obviates the aforementioned drawbacks or at least provides an alternative solution.
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 ameliorate one or more problems of the background or to at least provide a useful alternative solution that provides a higher reaction rate.
An object of the present disclosure is to provide a mechanism for oscillating a tool holder in a superfinishing operation.
Another object of the present disclosure is to provide a mechanism for oscillating a tool holder in a superfinishing operation that doesn’t require a change of parts for modifying an oscillation amplitude.
Yet another object of the present disclosure is to provide a mechanism for oscillating a tool holder in a superfinishing operation that modifies and sets the oscillation amplitude accurately by adjusting the angle of a spindle shaft and the repeatability is facilitated by using an encoder.
Still, another object of the present disclosure is to provide a mechanism for oscillating a tool holder in a superfinishing operation in which the maintenance and the adjustment of the parts are easier.
Yet another object of the present disclosure is to provide a mechanism for oscillating a tool holder in a superfinishing operation that significantly reduces vibrations and noise.
Another object of the present disclosure is to provide a mechanism for oscillating a tool holder in a superfinishing operation that reduces operating costs.
Yet another object of the present disclosure is to provide a mechanism for oscillating a tool holder in a superfinishing operation that extends the bearing life and generates consistent surface geometry.
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 relates to a mechanism for oscillating a tool holder for enabling a tool mounted on the tool holder to carry out the superfinishing operation, the mechanism comprises, a shaft enclosed in a housing, the shaft defined by a body having two operative ends, a block affixed to the body and enclosed within the housing; a pin configured to be engaged with the block, a spindle mounted to an operative top end of the pin, the axis of the pin being offset to the rotational axis of the spindle, and driving means configured to be mounted to rotate the spindle, wherein the driving of the spindle is configured to rotate the pin eccentrically which in-turn induces an angular displacement of the block causing the shaft to oscillate and which in-turn oscillates the tool on a surface that needs superfinishing.
In an embodiment, the tool holder is configured to be mounted on an operative end of the shaft by means of a pneumatic slide to facilitate the tool holder to be positioned at a desired angle with respect to the surface to be superfinished.
In an embodiment, wherein the block is defined by a horseshoe-shaped body having a cavity at its operative top portion.
In an embodiment, an operative bottom portion of the cavity is configured with an arcuate profile, and operative edges of the cavity are configured with at least one engaging means.
In an embodiment, a coupling means is configured to be received within the cavity to abut the arcuate profile, the coupling means is defined by a body having a recess, a flat bottom surface and a curved outer surface.
In an embodiment, the curved outer surface of the coupling means is rotatably engaged with the cavity by means of the engaging means.
In an embodiment, the recess is configured to receive a spacer block therein, and an operative bottom end of the pin is mounted to the spacer block to facilitate the transmission of motion from the pin to the block via the spacer block and the engaging means.
In an embodiment, the spindle is configured to drive the pin eccentrically which in-turn pushes two the engaging means via the coupling means to induce the angular displacement in the block, causing the shaft to oscillate and in-turn oscillate the tool on the workpiece surface that needs superfinishing
In an embodiment, the angular displacement of the block is in the range of ±9°.
In an embodiment, the tool is selected from a group of honing stones.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The mechanism for oscillating a tool holder in a superfinishing operation of the present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a sectional view of an oscillation unit in accordance with an embodiment of the present disclosure.
Figure 2 illustrates an isometric view of the oscillation unit of Figure 1 in accordance with the present disclosure.
Figures 3A and 3B illustrate a sectional view of an oscillation block, coupling means, and the eccentric arrangement of a pin with respect to the oscillation block and the spindle in accordance with the present disclosure.
Figure 4 illustrates a sectional view of the oscillation block and coupling means in the oscillatory driving mechanism in accordance with the present disclosure.
LIST OF REFERENCE NUMERALS USED IN DETAILED DESCRIPTION AND DRAWING
100 a mechanism for superfinishing operation
102 tool holder
104 tool
106 shaft
108 housing
110 block
110a cavity
110b arcuate profile
112 pin
114 spindle
116 driving means
118 encoder
120 spindle sleeve
122 timer belt and pulley
124 spindle shaft housing
126 pneumatic slide
128 spindle shaft adjustment point
130 coupling means
132 spacer block
134 engaging means
DETAILED DESCRIPTION
The present disclosure relates to a mechanism for oscillating a tool holder in a superfinishing operation. More particularly, relates to an oscillating unit for superfinishing operations with abrasive stone.
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 or section from another component, region, 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.
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
A typical superfinishing mechanism uses a motor with a connecting link to provide the rocking angular oscillation movement of the tool holder. Some standard oscillating unit converts a linear oscillation movement into an angular oscillation movement with the help of profiled plates for the surface finishing operation. However, such an oscillation mechanism generates a huge vibration and noise. Also, the angle adjustment for finishing operation is difficult, as such oscillations unit’s amplitude of oscillation modification or adjustment is critical and inaccurate.
In another conventional oscillation unit, a specially manufactured reversing servo motor is used which rotates clockwise and anticlockwise and provides direct drive to the stone holder. However, such an oscillation unit requires a setup change with new parts to modify the amplitude of oscillation.
Yet another existing oscillation unit requires additional maintenance and continuous adjustment and setup of parts due to its complex structure and a greater number of mechanical parts. Therefore, a precise adjustment of amplitude is not possible. Further, to make a variation in the raceway width, a new tool or tool holder is required, which is difficult, time-consuming and expensive.
The present disclosure envisages a mechanism (100) for oscillating a tool holder in a superfinishing operation. The mechanism (hereinafter referred to as the “oscillating unit”) advantageously generates the required output finish and consistent surface geometry by precise adjustment of the oscillation amplitude.
The present disclosure will now be described in detail with reference to Figures 1 through Figure 4. The present embodiment does not limit the scope and ambit of the present disclosure.
The oscillating unit (100) oscillates a tool holder (102) to enable a tool (104) mounted on the tool holder (102) to carry out superfinishing operations. The oscillating unit (100) comprises a shaft (106), a block (110), a pin (112), a spindle (114) and driving means (116).
In an embodiment, the shaft (106) is enclosed in a housing (108). The shaft (106) is defined by a body having two operative ends. One end of the shaft (106) is operatively coupled to the tool holder (102) using a pneumatic slide (126) and another end of the shaft is operatively coupled to an encoder (118).
In an embodiment, the tool holder (102) is configured to be mounted on an operative end of the shaft by means of a pneumatic slide (126) to enable the tool holder (102) to be positioned at a desired angle with respect to the surface to be superfinished.
The pneumatic slide (126) is mounted onto a bracket which is connected to the angularly oscillating shaft (106). The pneumatic slide (126) is actuated to enable contact between the tool (104) and the finishing surface. The pneumatic slide (126) provides the necessary polishing force to the tool (104) and acts as a compliance float.
In an embodiment, the block (110) is mounted on the body of the shaft (106) and supported by a bearing assembly to transmit the driving force from the shaft (106) to the block (110). The block (110) is mounted in a pivot style on the shaft (106). The block (110) and the shaft (106) are enclosed in the housing. The block (110) is defined by a horseshoe-shaped body having a cavity (110a) at its operative top portion.
In an embodiment, the operative bottom portion of the cavity (110a) is configured with an arcuate profile (110b) and the operative edges of the cavity (110a) are configured to accommodate the engaging means (134) in its operative configuration.
In an embodiment, the cavity (110a) of the block (110) is further configured to receive a coupling means (130). The coupling means (130) is received within the cavity (110a) to abut the arcuate profile (110b). The coupling means (130) is provided with a recess at its operative top portion and with a flat bottom portion. The side edges of the coupling means (130) have a single curved surface.
The recess of the coupling means (130) is provided to receive a spacer block (132) and the curved surface of the coupling means (130) is provided to rotatably engage with the cavity (110a) of the block (110) by means of the engaging means (134). Therefore, the coupling means (130) on movement, pushes the block (110) along the connected shaft (106) to oscillate angularly.
In an exemplary embodiment, the coupling means (130) is a guiding block configured to facilitate an oscillating movement to the block (110).
In an embodiment, the pin (112) is configured to be engaged with the coupling means (130) through the spacer block (132). The operative bottom end of the pin (112) is mounted in the spacer block (132).
In an embodiment, the spindle (114) is operatively engaged with the pin at the operative top end. Additionally, the pin (112) and spacer block (132) have their axes offset from the spindle's rotational axis (114). In fact, the spindle (114) is intended to drive the pin (112) eccentrically.
The spacer block (132) tends to linearly slide in the coupling means (130), which in turn reversely oscillates the coupling means (130). Further, this linear oscillation movement of the coupling means (130) is converted into a periodic angular motion of the block (110). Therefore, due to the eccentric nature of the spindle (114), the pin (112) and the spacer block (132), the linear oscillation motion transmitted from the spindle (114) gets converted into an angular movement of the block (110) in order to oscillate the tool holder (102) for superfinishing operation.
The spindle (114) is enclosed in a spindle sleeve (120). Further, the spindle sleeve (120) is operatively coupled to the driving means (116) using a timer belt and pulley (122) to provide a rotational motion to the spindle (114) through the spindle sleeve (120). The spindle sleeve (120) is housed in a bearing arrangement to provide a rigid support.
The spindle (114) is held eccentrically to the spindle sleeve (120), and its axis is offset from the axis of the pin (112). As a result of the eccentric arrangement, the pin (112) transmits rotational motion to the spacer block. The spacer block (132) slides linearly in the coupling means (130). This forces the coupling means (130) to move in a reversing linear oscillation in an axis perpendicular to the motion of the spacer block. Further, this reverse linear oscillation movement pushes two of the engaging means (134) via the coupling means (130), inducing an angular displacement in the block (110).
In addition, the coupling means (130) is in contact with the block (110). The linear oscillation of the coupling means (130) is converted into a periodic angular motion of the block (110), and as the shaft (106) is operatively connected to the block (110), the periodic angular motion of the block (110) drives the shaft (106) in a periodically reversing rotational motion along its own axis. This reversing rotational motion of the shaft (106) is translated to the pneumatic slide (126), which is connected at the operative end of the shaft (106). The pneumatic slide supports the tool holder (102) and the tool (104) is mounted on the tool holder (102). Therefore, the reversing rotational motion transmitted to the pneumatic slide is passed to the tool holder in the angular oscillatory path of the tool that polishes the finishing surface.
In an embodiment, the spindle (114) has a spindle shaft adjustment point (128) at its operative top end. The spindle shaft adjustment point (128) is operationally connected to the encoder (118), wherein the encoder is configured to measure the position of the spindle shaft adjustment point (128). Therefore, in order to modify the oscillation amplitude, the encoder measured value is used to determine the position of the spindle shaft adjustment point (128), which then modifies the oscillation amplitude accordingly.
In an embodiment, the amplitude of oscillation is adjusted by rotating the spindle (114) with a simple spanner.
In an embodiment, the driving means (116) is a servo motor with a timer belt and pulley (122).
In an embodiment, the angular displacement of the block (110) is in the range of ±9°.
In an embodiment, the tool (104) is selected from a group of honing stones.
In an exemplary embodiment, in a particular super finishing operation, the part or job containing the polishing surface is brought into the required position with respect to the tool (104) of the tool holder (102) either manually or with an automated system. Then, the part is clamped firmly to ensure that it is not displaced during the polishing operation. A suitable drive unit (not shown) is configured to rotate the finishing part, as the drive unit is responsible for rotating the part being polished.
The oscillating unit (100) is mounted on a vertically oriented servo-driven slide. The vertical slide, on actuation, moves the tool (104) into position to process the part. During the superfinishing operation, the tool holder (102) mounted on the pneumatic slide (126) is actuated. The pneumatic slide (126) of the oscillation unit (100) is actuated to engage the tool (104) in contact with the finishing surface. Once the tool (104) is brought into contact with the finishing surface, a signal is sent to the encoder which begins the actuation of the motor of the oscillation unit, which in turn begins the oscillation motion of the tool (104). After a pre-set duration, the oscillation unit (100) stops the oscillating motion and accordingly, the pneumatic slide (126) is actuated to disengage the tool (104) from the finishing surface.
The present disclosure provides the oscillation unit (100) which is used for a precise adjustment of the amplitude of oscillation with electronic feedback. The oscillation amplitude is modified by adjusting the angle of the spindle. The present oscillation unit (100) generates the required output finish and consistent surface geometry while optimizing the surface boundary layer.
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 AND ECONOMICAL SIGNIFICANCE
The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization of a mechanism for oscillating a tool holder in a superfinishing operation, that:
• doesn’t require a change of parts for modifying an oscillation amplitude;
• modifies and sets the oscillation amplitude accurately by adjusting the angle of a spindle shaft and the repeatability is facilitated by using an encoder;
• is accessed easily for maintenance and the adjustment of the parts;
• significantly reduces vibrations and noise;
• reduces operating costs;
• reduces operating costs; and
• extends the bearing life and generates consistent surface geometry.
The foregoing description of the specific embodiments so fully reveals 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.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
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 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.
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. ,
Claims:WE CLAIM:
1. A mechanism for oscillating a tool holder (102) for enabling a tool (104) mounted on said tool holder to carry out the superfinishing operation, said mechanism comprising:
• a shaft (106) enclosed in a housing (108), said shaft (106) defined by a body having two operative ends;
• a block (110) affixed to said body and enclosed within said housing (108);
• a pin (112) configured to be engaged with said block (110);
• a spindle (114) mounted to an operative top end of said pin (112), the axis of said pin (112) being offset to the rotational axis of said spindle (114); and
• driving means (116) configured to be mounted to rotate said spindle (114),
wherein the driving of said spindle (114) is configured to rotate said pin (112) eccentrically which in-turn induces an angular displacement of said block (110) causing said shaft (106) to oscillate and which in-turn oscillates the tool (104) on a surface that needs superfinishing.
2. The mechanism as claimed in claim 1, wherein said tool holder (102) is configured to be mounted on an operative end of said shaft (106) by means of a pneumatic slide (126) to facilitate said tool holder (102) to be positioned at a desired angle with respect to the surface to be superfinished.
3. The mechanism as claimed in claim 1, wherein said block (110) is defined by a horseshoe-shaped body having a cavity (110a) at its operative top portion.
4. The mechanism as claimed in claim 3, wherein an operative bottom portion of said cavity (110a) is configured with an arcuate profile (110b), and operative edges of said cavity (110a) are configured with at least one engaging means (134).
5. The mechanism as claimed in claim 4, wherein a coupling means (130) is configured to be received within said cavity (110a) to abut said arcuate profile (110b), said coupling means (130) is defined by a body having a recess, a flat bottom surface and a curved outer surface.
6. The mechanism as claimed in claim 5, wherein said curved outer surface of said coupling means (130) is rotatably engaged with said cavity (110a) by means of said engaging means (134).
7. The mechanism as claimed in claim 5, wherein said recess is configured to receive a spacer block (132) therein, and an operative bottom end of said pin (112) is mounted to said spacer block (132) to facilitate the transmission of motion from said pin (112) to said block (110) via said spacer block (132) and said engaging means (134).
8. The mechanism as claimed in claim 5, wherein said spindle (120) is configured to drive said pin (112) eccentrically which in-turn pushes two said engaging means (134) via said coupling means (130) to induce the angular displacement in said block (110), causing said shaft (106) to oscillate and in-turn oscillate the tool (104) on the workpiece surface that needs superfinishing.
9. The mechanism as claimed in claim 1, wherein the angular displacement of said block (110) is in the range of ± 9°.
10. The mechanism as claimed in claim 1, wherein said tool (102) is selected from a group of honing stones.

Dated this 25th day of April, 2024

_______________________________
MOHAN RAJKUMAR DEWAN, IN/PA – 25
OF R. K. DEWAN & CO.
AUTHORIZED AGENT OF APPLICANT

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, AT MUMBAI