Construction and technical modification of grinding wheels for internal cylindrical grinding using SCAMPER method of creative innovation design

This article describes a case study of an application of the method of creating innovations called SCAMPER for the development of new abrasive tools designed for machining of hard-to-cut materials. The SCAMPER method is used for innovative transformations of existing products, aimed at a modernization of their design, a construction and an extension of functions. This method was used in the procedure of modifying abrasive tools and it permitted a generation of a set of innovative solutions in this field. The methodology made it also possible to logically organize individual creative activities supported by the previously accumulated theoretical and experimental knowledge.


INTRODUCTION
The rapid growth of the automotive, aerospace, shipbuilding and medical industries forces the use of new types of materials with advanced physico-chemical properties. These materials are mostly hard-tocut due to their high strength and toughness, high affinity for machining tools, high friction coefficients and tendency to strengthen under the influence of temperature and deformation [2,4,21,22].
In most cases, conventional grinding wheels with standard grains or super hard grains are used to grind these materials [11,12]. However, the need for various types of modification of such tools is becoming increasingly common in order to extend their service life and to increase the machining potential. The modifications made so far mainly concern increasing the openness of the abrasive tool structure, among others by using special fillers and spherical corundum grains [19]. New types of crystalline ceramic binders have also been developed, which enable the regulation of intensity and rate of the wear and self-sharpening of tools [5][6][7]. There are also developed grinding wheels with micro-and macrodis-continuities of their active surfaces [9] as well as various impregnating agents preventing chip adhesion and bonding of tool surfaces [13,16,17].
Despite this development, progress in grinding of hard-to-cut is still insufficient. New solutions for highly efficient abrasive tools are being sought through modifications of existing abrasive tools and completely new constructional solutions. In the Department of Production Engineering at the Koszalin University of Technology, research has been conducted for a long time on the constructional development of new abrasive tools for internal cylindrical grinding, creating their prototypes and conducting operational research. Research was also carried out on their monitoring and diagnostics in the grinding process. Inspirations and directions of this development can be systematized based on the transformation model of the existing product, using nine integrated steps based on the SCAMPER method of the creative innovation design [3].

THE IDEA OF THE SCAMPER METHOD
The SCAMPER method is used for innovative transformations of existing products, aimed at a modernization of their design, construction and an extension of functions. This method assumes that every novelty is a modification of something that already exists [3]. Adaptation to specific needs is done on the basis of a list of questions, exploring the possibilities of specific modifications. A basic list of such questions was prepared in the middle of the 20th century by Robert Eberle. These questions are characterized by a specific logic, and in response to them, one obtains a full variance of innovative solutions of the existing product [3]. The first letters of these questions form the name SCAMPER: This is a basic list. For the purposes of this paper, an extended working list of questions adapted to the technical problem under development has been evaluated (Tab. 1). The presented steps show the directions of modifications made to grinding wheels used in internal cylindrical grinding processes. They were preceded by an extensive functional analysis and confirmed by exploratory tests. The developed set of structural and technical solutions of new tools has been developed for grinding of hard-to-cut materials [18].

MODIFIED INNOVATIVE ABRASIVE TOOLS
Constructional and technical modifications of small-sized grinding wheels for internal cylindrical grinding have been designed and mostly made in the form of technical prototypes and have been verified in experimental studies [1, 8-10, 13-17, 20]. Particular solutions were presented in Table 2   Monocrystalline cBN x 1000 Microcrystalline cBN x 10000 x 1000 x 500 Abrasive grains

FROM IDEA TO PROTOTYPE
In order to verify the utilitarian design of the modified innovative grinding wheels for internal cylindrical grinding processes described above, prototypes for most of them were made. To this end, certain technical assumptions have been made, based on the results of experimental studies carried out with conventional grinding wheels. The purpose of building these prototypes was to check the technical possibilities of their execution, to collect information on the technological character of particular solutions and to test them in the conditions of selected machining operations. With this in mind, the next steps from concept to prototype in relation to elaborated grinding wheels are shown in Figure 1. According to this procedure (Fig. 1), prototypes of abrasive tools were constructed and verified as shown in Table 2. The results of operational tests confirmed their suitability for machining of hard-to-cut materials. The efficiency of machining in relation to conventional tools has increased significantly as well as the operational life of these tools [1, 8-10, 13-17, 20].

CONCLUSIONS
The SCAMPER method used in the presented procedure of modifying small-sized abrasive tools, on the one hand, allowed to generate innovative solutions and, on the other hand, made it possible to logically organize individual creative activities.