Car repair tool handle pleasant Evaluation Analysis

        1 Introduction
        With the continuous growth of China's car ownership, car repair market increasingly large scale, in the process of vehicle maintenance workers repair shop to handle regular frequent use of work tools, handle tools have become indispensable vehicle repair shop a powerful tool. But not long-term repeated use ergonomic handle Tools, likely to cause workers concurrent musculoskeletal disorders, seriously affecting work efficiency. Pleasant design handle class tools for work safety and health of workers, to improve safety and reliability of the car repair shop workers labor efficiency and work, as well as to improve the quality of vehicle maintenance has a very important role. For this reason, many manufacturers for the development of tools to handle amenity handle Tools showed great interest, and as an important selling point of the product. Based on the auto 4S shop car repair amenity investigation and analysis tool handle, handle of Automobile repair tool handle amenity, for tool manufacturers to develop high-quality user-friendly tool handle has a very important significance.
        2 Handle Tools agreeableness Evaluation
        To design tool has a handle class amenity, it is necessary analysis tools to handle class comfort factor. We are through the survey and related businesses relevant literature at home and abroad come to influence the handle Tools comfort factor and presents relevant indicators handle class comfort evaluation tool.
        Tools affect handle comfort factor has 6: function factor; operating posture and muscle factors; hand and finger irritation and pain; stimulate hand side; the characteristics of the handle; aesthetics. These six factors we can be summarized as three meanings: functions, operations, posture and appearance. We can see that comfort correlation reliability, functionality, and ease of use hands together for the user with the handle of the greatest tools. The physical design of the comfort-related, professional-looking, good-looking style and color handle tool is unlikely. We should be key consideration in agreeableness handle tool design.
        Factors affect amenity handle tool design
        Since the tool handle class action directly with others that handle tool to control people through the handle of the tool is applied so pleasant handle Tools core design is the design of the tool handle. Tool handle pleasant design we first have to analyze the physical structure of the body by hand size and manpower to make improvements, and secondly we can handle the appearance of the form design tools to increase the comfort of the handle, and finally we could handle through improved material to improve the comfort tools. Following on from the physical structure of manpower, the appearance shape handle design and materials and other aspects of the handle Factors Affecting pleasant design of the tool handle.
        3.1 physiological structure of manpower
        Rich muscles on our hands, which is the most abundant when the ball of the hand muscles, thenar and hypothenar muscles, the muscles and the least part of it is the palm, the site is full of nerve endings inter phalangeal muscles. Therefore, cross-sectional shape of the tool handle should follow the physical structure of a human hand. According to the physical structure of manpower, handle tools in the study of amenity, the human hand is divided into AL zone delineated by the tool handle stimulation of these areas, we can more scientific evaluation agreeableness handle tools.
        Form 3.2 tool handle
        Form tool handle Meets Human palm physiological structure on the handle essential agreeableness tools. When pleasant morphological study of the impact tool handle to handle tool that can handle from the weight distribution and center of gravity, in the form of tool handles, tool handles cross-sectional shape and a handle diameter and length were analyzed.
        When the handle heavy tools or operating potential posture is not the time, when the work very easily lead to musculoskeletal injuries, physical and psychological impact on workers, it will greatly affect the efficiency and product quality. Thus, for a pleasant handle research tool, position the tool handle weight distribution and center of gravity has a very significant impact on the amenity tools. The current tools are generally handle one-handed operation, the weight of the tool handle general recommendations should not exceed 2kg, when weight is controlled between 1 ~ 2kg, studies show that the most comfort when the weight range of workers to operate.
        At the same time, to ensure the comfort of the tool handle, handle tools, the focus should be the center of the handle grip by the hand, wrist and arm so that the rotation does not occur during operation, wrist and arm, not subject to torsion, hand and arm does not produce fatigue. Manufacturers in the production tool handle, handle tools produced according to customer requirements of various shapes. Factors handle tool handle in the form of options, depending on the torque key size, orientation of parts, the position of the workers and the contact parts of the methods. For example, workers in the choice of the form of the tool handle, no need to bend the wrist in the form of work should make the wrist under various operating states are kept straight when you want to choose to work.
        Handle handle traditional tools we often use is a circular cross section, circular cross-section does not meet the natural state of hand when gripping. When the work is unstable gripping the handle very easily slipped from his hand. Triangular cross-section: tool handles too wide and easy to grip. At the same time, when the rotation of the handle will oppress palm, affecting blood flow operator's hand, refers to the production people numbness. And hexagonal close elliptical cross section: This section is a more ideal shape, close to the physical structure of the human hand, and directional handle tool for work, will have a greater friction when the hand holding the handle, the most suitable hand grip grip.
        In addition to cross-section of the handle a greater impact on the outside handle tools agreeableness, handle diameters and lengths also have some impact on amenity handle tools. Due to differences in the human body, each person's palm sizes, therefore, the diameter and length of the selection tool handle is also particularly important. For different handle tools, such as used car beauty polishing machine, workers in the operation of the force exerted by the arm requirements are not the same as the diameter and length of the handle is different; the maintenance of sex workers, hand length, hand width, hand length different, grip strength for the handle, the finger force peaks, etc. are also different, which requires the diameter of the handle and the tool length differs from the grip. For example, a large hand span handle small tools, or using small hand tools to handle large-span, maintenance workers on the great force, it is very easy to make fatigue during operation. Numerous studies show that the best tool handle grip range between about 40 ~ 50mm. In order to allow maintenance workers have more grip space, we recommend the length of 130mm or more grip more comfortable. However, since the handle is not fixed to a tool for personal use, so we guarantee based on the performance of the tool handle, handle tools make pleasant balance requirements, the choice of optimal diameter and length of the handle, must take into account the requirements, Taken together, so as to play amenity tool.
        3.3 Material tool handle
        According to the above comfort to handle tools correlation figure shows that when workers in the use of tools to handle, if sweating, no non-slip handle, wet feeling handle, the handle of hardness and skin inflammation occur, which are associated with the handle are made of very great relationship, handle material selection reasonable or not will seriously affect the comfort of the operation of the tool handle. Currently handle material selection mainly from the insulation, lightweight, wear-resistant, moisture-proof anti-sweat, strong grip and other aspects, so most choose wooden handle, rubber and synthetic materials, such as insulation. At present, foreign more advanced tools to handle most use of composite laminate material that can achieve requirements pleasant handle tools. The domestic manufacturers in the design and manufacture of tool handles, in order to ensure a better grip handle, so that between the hand and the handle a larger friction, often to handle parts of the surface layer of paste processing, so you can make the tool handle It has better grip, reducing the force to prevent slipping handle tools and the like.
        4 car repair tool handles pleasant Evaluation Analysis
        In order to more accurately assess visual amenity handle car repair tools, our Ningbo major 4S shop repair shop handle tools carried out by research. Tool handle is comfortable and pleasant to use, maintenance workers can be evaluated through the use of subjective feelings auto 4S shop. To this end, we selected the Ningbo three large-scale maintenance 4S shop the same class as samples screwdriver shop, 4S shop operator to select an experienced teacher, by the feelings they use to evaluate the different shape of the handle amenity tools . We handle the forces measured by the pressure sensor laboratory, experimental data and subjective evaluation to study the pleasant maintenance tools. The evaluation of the selected cross-sectional shape are circular, triangular and hexagonal handle.
        Side of the cylindrical shape of the handle, respectively, double conical, double conical and reverse conical shape of the handle a total of 12 different screwdrivers, are to undergo a wear-resistant surface of the handle, non-slip treated. By the axial force measured by the force sensor and finger action force, maintenance workers subjective feelings (mainly through the comfort level, the comfort level is divided into 0 to 5) to the pleasant evaluation. When maintenance workers work with a screwdriver, the force sensor measured axial force and finger together to effect change over time. FIG. We can see from the figure at the beginning of the use of the tool handle, handle axial force is greater than the effect of finger force, with increased duration of action, fingers and a significant increase in the role of force greater than the axial force, use a long time, easily lead to finger numbness, fatigue, etc. so that the bubble is not a comfortable feeling.
        By 4S shop repair shop workers more than 12 different cross-sectional shape of the handle of a screwdriver and side usage within the specified time feedback, we acquired through research data, handle tools come in different shapes as shown in Fig. 7 comfort level diagram. From the figure we can conclude that, different sides of the circular cross-sectional shape of the tool handle, comfort high to low is: reverse two conical, cylindrical, conical and double conical. Hexagonal cross-sectional shape of the side handle different tools, from high to low is comfort: reverse two conical, cylindrical, conical and double conical. Different sides of the triangular cross-section shape of the tool handle, comfort high to low is: reverse two conical, cylindrical, conical and double conical. On the whole in terms of comfort, the reverse side of the double-conical shape of the handle to the best comfort, cylindrical second. Cross-sectional shape of the tool handle relatively good comfort triangle, followed by a regular hexagon.
        By different shapes of handle tools force sensors measured using force change map finger action could be drawn, the shape of the side, the side of the conical shape of maximum force using a finger grip tool needs to be applied, the smallest cylindrical . On the cross-sectional shape, the triangular cross-section when the smallest finger grip tool needs to apply maximum force, circular cross-section. Comprehensive two factors, the sides can be drawn is cylindrical in shape, the cross section is circular screwdriver, finger action required minimum force, to be comfortable to use.
        5 Conclusion
        The shape of the handle is pleasant impact tool handle of a very important aspect, whether the tool manufacturer will consider in the design of the shape of the handle and pleasant, you can take advantage of in the design of ergonomic principles for the physical structure of the human palm, design suitable workers operating habits and comfort strong handle tools. In addition, the handle material, security patterns, durability and handle tools, portability, ease of use is also a factor worth considering. This article from the maintenance workers use to evaluate the subjective feelings of vehicle maintenance tool handle amenity, but agreeableness tools alone can not unilaterally indicators to evaluate all aspects of the combination of factors need to be evaluated, so that the tool handle in the car repair process the optimum comfort, thereby increasing productivity, reducing human fatigue and injury.