REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from Indian provisional patent application 202211006805 filed on 9 ^th February 2022.

TECHNICAL FIELD

[0002] The present invention generally relates to a method of optimizing the grinding cycle time of at least a part of an article. More particularly, the invention describes a method of optimizing the grinding cycle time of an article via a premeasuring process.

BACKGROUND OF THE INVENTION

[0003] Various methods of grinding an article are known in the art. Commonly, the grinding process parameters are maintained constant for the entire grinding cycle of a batch of articles. The grinding process parameters are thus based on the maximum available grinding allowance in the batch of articles. This results in a higher time taken to grind an article with a low grinding allowance. For a continuous process of grinding articles, it becomes difficult to calculate the grinding allowance for each part and recalibrate the grinding process parameters. This results in a waste of time, and also reduces the consistency and quality of the grinded articles, and the tools used for the same. Methods of measuring the grinding allowance for an article before a grinding process are known in the art. For example, Japanese patent application JPS61252065A and JPS61252064A describe a device for controlling grinding, that uses a sensor to measure an inner or outer diameter of a workpiece, and using the sensor output to calculate a machining allowance. Chinese patent application CN1055652C describes a method for time-controlled grinding. The method described herein uses a measuring instrument to measure a machining allowance, which is integrated with the grinder. However, the methods described herein may be suitable for grinding of single pieces or small batches, and are not effective for large batches or continuous grinding processes.

[0004] Therefore, there is a need for a method of optimizing the grinding cycle time of parts of an article, which obviates the aforesaid drawbacks, especially for large batches of articles, or continuous grinding processes.

OBJECT AND SUMMARY OF THE INVENTION

[0005] An object of the present invention is to provide a method of grinding an article. The method includes the steps of pre-measuring a grinding allowance before start of a grinding process to obtain a pre-measured grinding allowance, calculating a grinding index based on the pre-measured grinding allowance to obtain a calculated grinding index, grinding the article based on the calculated grinding index; and monitoring the grinding process by means of an in-process gauge.

[0006] These and other objects of the invention herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing the spirit thereof, and the embodiments herein include all such modifications. BVRIEF DESCRIPTION OF THE DRAWINGS

[0007] The embodiments of the invention are illustrated in the accompanying drawings, throughout which the reference letters indicate corresponding part in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:

[0008] Fig. 1 illustrates a method of grinding an article, in accordance with an embodiment of the present invention.

[0009] Fig. 2 illustrates a graph of distance as a function of time during the operation of a method of grinding an article, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0010] While various embodiments of the invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions may occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed.

[0011] In the specification and the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings: [0012] The singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. “Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not. “Substantially” means a range of values that is known in the art to refer to a range of values that are close to, but not necessarily equal to a certain value.

[0013] Other than in the examples or where otherwise indicated, all numbers or expressions referring to quantities of ingredients, reaction conditions, and the like, used in the specification and claims are to be understood as modified in all instances by the term “about.” In some aspects of the current disclosure, the terms “about” or “approximately” are defined as being close to as understood by one of ordinary skill in the art, and in one non-limiting embodiment the terms are defined to be within 10%, alternatively within 5%, alternatively within 1%, or alternatively within 0.5%.

[0014] As used herein, the term “substantially” and its variations are defined as being largely but not necessarily wholly what is specified as understood by one of ordinary skill in the art, and in one non-limiting aspect substantially refers to ranges within 10%, within 5%, within 1%, or within 0.5%.

[0015] Various numerical ranges are disclosed herein. Because these ranges are continuous, they include every value between the minimum and maximum values. The endpoints of all ranges reciting the same characteristic or component are independently combinable and inclusive of the recited endpoint. Unless expressly indicated otherwise, the various numerical ranges specified in this application are approximations. The endpoints of all ranges directed to the same component or property are inclusive of the endpoint and independently combinable. The term “from more than 0 to an amount” means that the named component is present in some amount more than 0, and up to and including the higher named amount.

[0016] As used herein, “combinations thereof’ is inclusive of one or more of the recited elements, optionally together with a like element not recited, e.g., inclusive of a combination of one or more of the named components, optionally with one or more other components not specifically named that have essentially the same function. As used herein, the term “combination” is inclusive of blends, mixtures, alloys, reaction products, and the like.

[0017] As used herein, the term “grinding” refers to a method of shaping an article by abrading the material of the article using a hard material.

[0018] As used herein, the term “cycle time” refers to the time required for grinding one component of a batch of articles.

[0019] As used herein, the term “grinding allowance” refers to the amount of material that is to be removed in a grinding process.

[0020] As used herein, the term “grinding index” refers to the distance from a reference point to starting position of grinding.

[0021] One embodiment of the present invention refers to a method of grinding an article. The method includes the steps of pre-measuring a grinding allowance before start of a grinding process to obtain a premeasured grinding allowance, calculating a grinding index based on the premeasured grinding allowance to obtain a calculated grinding index, grinding the article based on the calculated grinding index; and monitoring the grinding process by means of an in-process gauge.

[0022] In an embodiment of the present invention, the method of grinding an article may be carried out on a lathe. In another embodiment of the present invention, the method for grinding an article, is carried out on an internal or external grinding unit with magnetic or pressure clamping of the article.

[0023] In an embodiment of the present invention, a pre-process or in- process gauge may be used. In an embodiment of the present invention, the pre-process or in-process gauge may be a contact-type gauge or a non- contact-type gauge. In an embodiment of the present invention, the pre- process or in-process gauge may be a contact-type gauge.

[0024] In an embodiment of the present invention, the in-process gauge may be a diameter measurement gauge. In an embodiment of the present invention, the in-process gauge may be an acoustic gauge. In another embodiment of the present invention, the in-process gauge may be an optical gauge. In another embodiment of the present invention, the in- process gauge may be a mechanical gauge. In yet another embodiment of the present invention, the in-process gauge may be an electro mechanical gauge.

[0025] In an embodiment of the present invention, the grinding allowance is the amount of material that is to be removed in a grinding process. In an embodiment of the present invention, the grinding allowance is a variable quantity.

[0026] In an embodiment of the present invention, the grinding allowance is pre-measured for every part in a grinding cycle.

[0027] In an embodiment of the present invention, the grinding process is carried out using a grinding wheel.

[0028] In an embodiment of the present invention, the method of grinding an article is used in a continuous, a continual, or a non-continuous grinding operation. In an embodiment of the present invention, the method of grinding an article is used in a non-continuous grinding operation. In another embodiment of the present invention, the method of grinding an article is used in a batch- wise grinding operation. In an embodiment of the present invention, the method of grinding an article is used in a continuous grinding operation. In an embodiment of the present invention, the method of grinding an article is used in a continual grinding operation.

[0029] In an embodiment of the present invention, the article may be symmetric or non-symmetric in shape. In another embodiment of the present invention, the article may be circular, rectangular or square in shape. In an embodiment of the present invention, the article may be composed of steel, aluminium or brass.

[0030] In an embodiment of the present invention, the article may be a bearing ring.

[0031] In an embodiment of the present invention, the grinding index refers to the distance from reference point to starting position of grinding. In an embodiment of the present invention, the grinding index is calculated as the final article size minus the grinding wheel diameter plus the grinding allowance. The grinding index may thus be represented by the Formula (1) below:

[0032] Grinding Index = Final article size - (grinding wheel diameter + grinding allowance) Formula (1)

[0033] In an embodiment of the present invention, the cycle time is reduced by about 5% when the part is grinded according to a method of grinding, according to an embodiment of the present invention. In another embodiment of the present invention, the cycle time is reduced by about 10% when the part is grinded according to a method of grinding, according to an embodiment of the present invention.

[0034] A method of grinding an article in accordance with one embodiment of the present invention will now be described with reference to the drawings.

[0035] The flowchart depicted in Fig.l is an example embodiment of the method 100 of grinding an article. The method 100 includes the steps of premeasuring 102 a grinding allowance before the start of a grinding process, calculating 104 a grinding index based on the pre-measured grinding allowance, grinding 106 the article based on the calculated grinding index, and monitoring 108 the grinding process by means of an in-process gauge.

[0036] As shown in Fig. 2, a graph 200 of distance as a function of time during the operation of a method of grinding an article, in accordance with an embodiment of the present invention. The graph indicates the position of the grinding wheel as a function of the process time. Distance 202 indicates the grinding index as calculated using Formula (1), distance 204 indicates the approach of the article to the grinding wheel, distances 206 and 208 refer to rough grinding of the article, distance 210 refers to fine grinding of the article, followed by 212 which refers to the retraction of the grinded article from the grinding wheel.

[0037] The results of the grinding process are shown below in table 1. Columns 1 and 2 show the grinding cycle time for a process according to an embodiment of the present invention as described in Example 1, while Columns 3 and 4 show the grinding cycle time for a process according to an embodiment of the present invention as described in Comparative Example 1. Thirty runs were carried out for each of the processes, and the total cycle time as well as the per-part cycle time computed. [0038] Table 1: Grinding process results for Example 1 and Comparative Example 1. [0039] It is observed from the table that the total cycle time for the process according to an embodiment of the present invention, as described in Example 1 was calculated to be 587 seconds, while the total cycle time for the process described in Comparative Example 1 was 616.5 seconds. This implies a reduction of 4.78 per cent in the per part grinding time.

[0040] It is also observed from the table that the average cycle time per part for the process according to an embodiment of the present invention, as described in Example 1 was calculated to be 19.57 seconds, while the average cycle time per part for the process described in Comparative Example 1 was 20.55 seconds. This implies a reduction of 4.77 per cent in the per part grinding time.

ADVANTAGES

[0041] The technical advantages brought in by the present invention are as follows;

1. The process enables a determination of maximum grinding allowance in a continuous grinding cycle.

2. The process provides consistency in output quality of the grinded parts, thus reducing wastage.

3. The process provides an overall reduction of 5 to 10 per cent in the cycle time, which is a significant reduction in cycle time.

[0042] While considerable emphasis has been placed herein on the components and component parts of the various embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the embodiments without departing from the scope and spirit of the invention. These and other changes in the various embodiment 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.