what the directives and technical standards state …

Rome, May 12 – Let’s go back to talking about Inail projectDefinition of innovative guidelines, based on the current state of the art, for the design, construction, certification and remediation of machines, equipment and work environments with low risk of exposure to noise and vibration for workers“Which aims to define the most appropriate procedures and techniques to reduce the risk of exposure to noise and vibration for workers.

Related to the project is the publication of the document “Acoustic and vibration certification of machines. Operational Manual” which, prepared by the Department of Medicine, Epidemiology, Occupational and Environmental Hygiene (DIMEILA) in Inail, deals with aspects of. machine certification.

Having already presented, with reference to this last document, the acoustic certification and having mentioned the declaration of the vibrations transmitted by the machine, today’s article continues to talk about vibration certification with reference to the following topics:

Machinery Directive, essential requirements and seats

As already mentioned in other articles, the basic points regarding the risk of vibrationAnnex I. from The Machinery Directive (2006/42 / EC) concerns the general criteria (1.5.9), the preparation of instructions (1.7.4.2), the indications for portable hand-held and hand-held machines (2.2) and for mobile machines (3.6)), also with reference to the methods to be used for measuring vibrations and paragraph 1.1.8 concerning i seats.

In particular, we dwell on point 1.1.8 (seats) and take a box from the document showing its contents:

It is emphasized in this connection that the requirement in point 1.1.8 of Annex I to the Machinery Directive therefore deals with “a specific aspect of the interface between the operator and the machinery which may cause discomfort, fatigue and health damage in case of incorrect design “.

That first part stipulates that the machine “is designed to allow the fitting of seats” where appropriate and if working conditions allow it. “Manufacturers must therefore consider whether operators could be more comfortable and perform all or part of their tasks more comfortably and efficiently seated In this case, the workplace, in other words the point on the machine where the operator is sitting, must be designed in such a way that the necessary seats can be fitted, which means that special attention must be paid to the height of The work surfaces, the location and shape of the controls and other parts of the machinery to which the operator must have access, as well as the space in which to place the seat and the maneuver of the driver’s upper and lower limbs “.

That second paragraph the document continues – this applies in the event that “the operator remains seated during the work activity and the workplace is an integral part of the machine; in other words, the driver’s seat is not installed on the floor next to the machine, but on parts of the machine itself. In this case, the seat must be delivered with the machine ”.

That according to and third paragraph then define in seating requirements.

The seat “shall be so designed as to enable the operator to maintain a stable position taking into account predictable conditions of use, in particular predictable movements of the machinery. The relevant parameters of the seat itself, such as seat height, width, depth and the inclination, position of the backrest and the position of any armrests and footrests must be adjustable to take account of the variation of the physical dimensions of the seat. , including the pedal operated by the operator, by equipping the position of the seat, controls or both with an adjusting device. exposed to vibrations due to the operation of the machine itself or the movement of the machine on uneven ground, one way to reduce the risk of exposure to mechanical vibrations transmitted to the whole body is to equip the seat with a suitable suspension system to reduce vibrations.

The machines and indications in the Vibration Directive

The document also focuses on Directive 2002/44 / EC of 25 June 2002 on minimum health and safety requirements for exposure of workers to the risks arising from physical agents (vibrations).

This directive, often referred to as the Vibration Directivewas implemented by Italian law through Legislative Decree 187/2005 and subsequently repealed by Article 304 of Legislative Decree of 9 April 2008 n. 81.

Directive 2002/44 / EC “sets exposure limit values ​​and action values; specifies the obligations of employers in determining and assessing risks; sets out the measures to be taken to reduce or avoid exposure and explains in detail the methods of providing workers with proper information and training; “. In addition, the directive requires EU Member States to “put in place an appropriate system for monitoring the health of workers at risk of vibration”.

The inail document does not go into the details of this directive, as the product manual focuses specifically on the vibration certification of the machines.

Vibration certification and technical regulations

So about general technical standards The inail document states that “the terms and definitions regarding mechanical vibration and shock are defined in the standard UNI 9513: 1989prepared in accordance with the draft standard ISO / DIS 2041: 1986draft standard ISO 2041: 1990now replaced by ISO 2041: 2018Mechanical vibration, shock and condition monitoring – Vocabulary“.

In particular, the standard distinguishes between “vibrations transmitted to the hand-arm system (HAV) and vibrations transmitted to the whole body (WBV)”. And almost always “the measurement of the vibration acceleration transmitted to the hand-arm system (HAV) is performed in accordance with what is described by the standards UNI EN ISO 5349-1: 2004 And UNI EN ISO 5349-2: 2015“.

It is then stated that measurement of vibration acceleration transmitted to the whole body (WBV) ”is usually performed in accordance with the standard UNI ISO 2631-1: 2014 Mechanical vibration and shock – Assessment of human exposure to whole body vibrations – Part 1: General requirements“Which” defines the methods for measuring periodic, random, and transient vibrations transmitted to the entire body.

The document then reports information about the standard UNI ISO 2631-5: 2019 Mechanical vibrations and shocks – Assessment of human exposure to whole-body vibrations – Part 5: Method for assessing impulsive vibrationson the norm UNI CEN / TR 15172: 2008 Whole Body Vibration – Vibration Risk Reduction Guidelines – Part 1: Engineering Design Method for Machine Design and on the norm UNI EN 12096: 1999: Statement of vibrator emission values.

It is then stated that the norm UNI EN 1299 provides “guidelines to ensure that manufacturers provide useful and adequate information for the selection and design of a vibration isolation system, in order to reduce the risks associated with vibration generated by the machine”.

Also with the norm UNI EN 12096The standards UNI EN 1032: 2009: Mechanical vibration – Examination of mobile machines to determine the values ​​of vibration emission it is considered as “the basic standard for evaluating the vibration emission of mobile machines transmitted to the whole body or to the hand-arm system. The purpose of the standard is that the procedures laid down by the various technical standardization committees for the different families of machines:

  • is as homogeneous as possible and complies with the general standards for measuring vibration emissions;
  • provide manufacturers with a standardized method for determining and declaring the emission values ​​of their machines;
  • refer to the latest techniques and methods for measuring vibration emissions;
  • allow the user or inspection bodies to compare the emission values ​​of different machines and verify the emission values ​​provided by the manufacturer.

In conclusion, we refer to the reading of the other details in these technical standards, remembering that Appendix B.2 of the Inail Manual presents a normative database with about 100 vibration standards, including generic standards and subsequent product standards, updated on the date of publication of the manual (October 2020).

RTM

Download the document from which the article was taken:

Inail, Department of Medicine, Epidemiology, Occupational and Environmental Hygiene, “Acoustic and vibrating certification of machines. Operating manual “, edited by Patrizio Fausti, Cristina Marescotti, Francesco Pompoli and Andrea Santoni (University of Ferrara – Department of Engineering), Eleonora Carletti and Francesca Pedrielli (Imamoter – Institute for Agricultural and Earth moving machinery – National Council of Research), Alessandro Peretti (School of Specialization in Occupational Medicine, University of Padua), Jacopo Griguolo (Technical Expert in Environmental Acoustics), Pietro Nataletti and Antonio Moschetto (Inail – Department of Medicine, Epidemiology, Occupational and Environmental Hygiene), manual prepared as part of Bric Inail ID26 project of Inail Research Activities Plan 2016 – 2018, Health and Safety Series, 2020 edition (PDF format, 5.37 MB).

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