EP1994381A1

EP1994381A1 - Vibration dosimeter and method for determining the daily vibrational loading

Info

Publication number: EP1994381A1
Application number: EP07703854A
Authority: EP
Inventors: Andreas Strasser; Markus Roth
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2006-03-02
Filing date: 2007-01-15
Publication date: 2008-11-26
Also published as: US20090140154A1; DE102006009657A1; CN101395455A; US7818141B2; WO2007098980A1

Abstract

The invention relates to a vibration dosimeter (2) and a method for determining the daily vibrational loading of persons who are exposed to mechanical oscillations at their place of work due to the operation of a work means and in particular of a manually operated electronic tool (4, 6). What is provided is that the dosimeter (2) comprises a determination device (12, 18) for determining the effective daily operating duration of the work means (4, 6), a computer device (22) for calculating a daily work time until a specified trigger value or exposition limit value of the vibrational loading is reached from a work-means-typical vibration value and the trigger value or exposition limit value, and a comparison device (24) for comparing the determined effective daily operating duration of the work means with the calculated daily work time until the specified trigger value is reached.

Description

Vibration dosimeter and method of determining the daily

vibration load

The invention relates to a vibration dosimeter and a method for determining the daily vibration load according to the preamble of claims 1 and 11, respectively.

State of the art

The European Parliament and the Council of the European Commission have considered it necessary to introduce measures to protect workers from hazards due to their effects on the health and safety of workers, and therefore in the EU Directive 2002 / 44 sets out minimum requirements that impose specific measures on the employer above a daily trigger level or a daily exposure limit value. The assessment of the extent of exposure may be made, according to the Directive, either by means of an estimate based on the manufacturer's information on the level of vibration caused by the equipment and by observing specific procedures or by measurement. However, estimates are often very inaccurate and difficult for the workers to understand, while measurements are relatively expensive They require determination of the RMS value of the frequency-weighted acceleration in three orthogonal directions, which is also required for hand-held or guided devices on each hand. This requires a relatively complex and different measuring equipment for each tool, which, in line with standard 5349-2: 2001, must be adapted to the specific characteristics of the vibration to be measured, the environmental factors and the technical characteristics of the meter, so that the assessment of the extent individual field exposure in the field using such a method is very difficult.

From EP 1 586 875 A1 a vibration dosimeter is known, which is adapted to the hand of an operator of a working device and with a sensor for measuring the occurring vibration levels to which the operator is exposed, a device for calculating the cumulative exposure, and a Device for transmitting the recorded data to the operator-equipped.

Furthermore, DE 101 19 252 A1 discloses a device for the personal measurement of characteristic values of the hand-arm and the whole-body vibration load at workstations (vibration dosemeters) which, in addition to the acquisition of vibration measured values, also permits the detection of other physical measured variables. which are considered relevant for the assessment of the effect of vibrations on the human body.

Advantages of the invention With the vibration dosimeter according to the invention and the method according to the invention, workers are given a simple and cost-effective option without the use of expensive, multidimensional acceleration transducers, the daily vibration load by a work equipment used at the workplace or exceeding the triggering threshold set in the EU Directive 2002/44. or exposure limits due to the use of the equipment.

The invention is based on the idea to determine for each tool a manufacturer-specific vibration value and specify for example on the tool itself or in its instruction manual, and from this typical working vibration value and set by the EU Directive 2002/44 trigger value or exposure limit one to calculate the daily working time until this trigger value or exposure limit value is reached, which can then be compared with the actual effective daily operating life of the work equipment to detect any overshoots.

In principle, the vibration dosimeter according to the invention and the method according to the invention can be used at any workstation where an employee is exposed to hand-arm or whole-body vibration, for example at construction sites where workers often experience different vibrations during the day Work equipment are employed.

In the context of the present application, the term "effective daily operating time" essentially only covers the working hours of the company - A -

Work equipment in which this generates stronger vibrations, that is, in other words, no idle time.

Another advantage of the vibratory dosimeter according to the invention is that it can be easily and quickly changed when working with different, vibration-generating work tools at each change of a working fluid, with only the typical work vibration value for the new work equipment must be entered into the dosimeter.

The typical vibration level, as with the action value and the exposure limit value of EU Directive 2002/44, is preferably an acceleration value expressed in units of m / s ² .

In a preferred embodiment of the invention, the vibration dosimeter comprises a display device which indicates the exceeding of the prescribed exposure value or exposure limit value of the vibration load if the determined effective daily operating time of the or each working fluid in the working state is the calculated working time until reaching the prescribed triggering value or exposure limit exceeds the vibration load. The display device could for this purpose comprise a small display, for example an LCD display, but because of the vibration load of the dosimeter itself, a more robust display device is preferred which comprises at least two and preferably three differently colored light-emitting diodes. For example, a green light emitting diode may be used, which indicates by illumination that the determined effective daily operating time is the calculated working time until the prescribed trip value is reached while an orange LED is turned on, if the effective daily operating time determined exceeds the calculated working time until the prescribed action value is reached, but not the calculated working time until reaching the exposure limit. A red LED may be used to indicate that the calculated working time has been exceeded until reaching the exposure limit.

If the operating time of the working fluid is interrupted over a longer period of time, for example longer than 8 hours, the determined effective daily operating time of the or each working fluid is preferably automatically reset to zero.

Preferably, the invention is used in connection with electrically driven work equipment, such as hand-held electric tools, since in the case of electrical appliances, the effective daily operating time can be determined relatively simply via the power consumption of the appliance in the working condition.

In this case, the vibration dosimeter can be conveniently integrated either in the device itself or in a socket, via which the respective device is connected to a power supply line or a power supply network. The latter variant has the advantage that the same socket used when changing the device and thus the vibration load can be measured by all devices with a single dosimeter.

Alternatively, the vibration dosimeter may be configured to be worn by the worker either as a wristwatch or mounted on the respective device. In this case, appropriate moderately determined by means of a simple acceleration sensor by a reference measurement of the acceleration level of the device at idle and in the working state and stored in the dosimeter. The dosimeter then records during the entire working day whether the device is in the working, idle or off state and compares the determined effective operating time of the device with the daily working time calculated from the typical vibration value of the device until reaching the triggering value resp the exposure limit.

In order to provide evidence of compliance with EU Directive 2002/44 and / or to provide a more detailed analysis of the vibration load, the vibration dosimeter may conveniently have an interface, such as a USB port or memory card, so that the work, idle - or off times of the device can be transmitted to a computer together with the typical work vibration value.

drawing

The invention will be explained in more detail in four embodiments with reference to the accompanying drawings. Show it:

1 shows a schematic representation of components of a vibratory dosimeter integrated in a hammer drill;

Fig. 2 is a perspective view of the hammer drill;

3 shows a perspective view of a socket with a built-in vibration dosimeter; 4 shows a schematic representation of components of the vibration dosimeter installed in the socket;

5 is an enlarged perspective view of a vibration dosimeter for releasable attachment to a working means.

Fig. 6 is a schematic representation of components of the vibration dosimeter of Fig. 5;

FIG. 7 is a perspective view of the vibration dosimeter of FIG. 5 after attachment to a cordless hammer; FIG.

Fig. 8 is a perspective view of a wristwatch with an integrated vibration dosimeter;

9 shows a schematic representation of components of the vibration dosimeter from FIG. 8.

Description of the embodiments

The drawing shows several installation variants for a vibration dosimeter 2, which is used to determine the daily vibration load of a worker when working with a motor-driven, in the drawing by way of example in the form of a network-dependent rotary hammer 4 (FIG. 2) or a battery-operated hammer 6 (FIG ) shown working equipment is used. Since the use of these power tools 4, 6, in particular in impact drills or hammers, exposes the operator to considerable hand-arm vibration, which, when exposed to prolonged exposure, has an effect on the health of the worker. the employer is obliged to take the measures specified in EU Directive 2002/44 if the worker's vibration exposure in the case of hand-arm vibrations has a daily tripping value of 2.5 m / s ² or daily exposure limit of 5 m / s ² .

The vibration dosimeter 2 described below makes it possible to easily and inexpensively determine this vibration load or the exceeding of the triggering or exposure limit value.

The illustrated in Figures 1 and 2, integrated in the hammer 4, powered by the power cable 8 and a transformer 10 from the network dosimeter 2 includes for this purpose at least one transducer 12 for receiving suitable operating variables of the hammer drill 4, such as the current consumption its electric drive motor 14 and / or its speed, as well as an internal timer 16, from whose measured values can be determined in an evaluation 18 of the dosimeter 2 an effective daily operating time of the device 4, ie the time from commissioning, in which the device 4 is in the working state, with idle or off times are not counted. The dosimeter 2 or the evaluation electronics 18 further comprises a memory 20 in which a device-specific vibration value ascertained by measurements for the hammer drill 4 is stored, which has the unit m / s ² like the triggering value and the exposure limit value. The evaluation electronics 18 further comprises a processor 22 which, from the daily triggering or exposure limit values set in the EU directive and the device-specific vibration value, a daily working time until the triggering time is exceeded. value or the exposure limit value calculated according to the following relationships:

8 hx 2.5 m / s ² x 2.5 m / s ²

AZA = (1)

(Diet) ²

8 hx 5 m / s ² x 5 m / s ²

AZ _E = (2)

(V device)

wherein Z _A and Z _E, the daily working up to the exceeding of the trip value or the exposure limit value V and _Ge advises the device-type vibration value.

The processor 22 comprises a comparator 24, which compares the calculated daily working time until the trigger value or the exposure limit value is exceeded with the determined effective daily operating time of the device 4 and indicates a possible overshoot of the values on a display 26. The display 26 comprises a green, an orange and a red LED 28, 30, 32, of which the green 28 is illuminated, as long as the calculated daily working time is not exceeded by the operation of the device in the working state until the action value is exceeded. The orange LED 30 lights up as soon as the effective daily operating time of the device 4 exceeds the calculated daily working time until the trip value is exceeded. The red LED 32 is turned on when the exposure limit is exceeded, namely, when the determined effective daily operating time of the device 4 exceeds the calculated daily working time until the exposure limit is exceeded. The transmitter 18 also includes a reset circuit 34, which resets the determined effective daily operating time of the device 4 to zero, when the device 4 is longer than 8 hours in the off state. In addition, a reset button (not shown) is provided for manual reset.

In the case of the dosimeter 2 illustrated in FIGS. 3 and 4, which is integrated in a socket 36, the measuring transducer 12 measures the current flowing between a mains plug 38 and a socket 40 of the socket 36. In contrast to the previously described dosimeter 2, an input part 42 is additionally provided, on which the respective device-specific vibration value of the connected device 4, 6 removed, for example, from a user manual can be entered into the dosimeter 2 or changed when changing a device 4, 6 , As described above, the transmitter 18 determines the effective daily operating time of each connected device 4, 6 from the previously determined by reference measurements power consumption in the working, idle and possibly standby state to the operating time with the according to the relationships (1). or (2) compare calculated daily working time until the action value or exposure limit is exceeded and indicate overshoots by activating the orange or red LEDs 30, 32 of the display 26 on the front of the socket 36.

The dosimeter 2 has an additional interface 44, for example a USB port, with which the effective daily operating time and, if necessary, additional idle and idle times of the connected device 4, 6 for more accurate evaluation by the employer and as Proof of compliance with EU Directive 2002/44, for example, can be transferred to a PC.

In the case of the dosimeter 2 powered by a battery 46 shown in FIGS. 5 to 7, which is fastened to the outside of the device 6, as shown in FIG. 7, the transducer 12 comprises a simple acceleration sensor 48 instead of an ammeter Help can be determined by a reference measurement of the acceleration level of the device 6 in idle and in the working state and stored in the memory 20. By comparing the stored acceleration levels with the respective acceleration measured by the acceleration sensor 48, the processor 22 determines the effective daily operating time of the device 6 to then compare it to the daily working time to exceed the threshold value or exposure limit as previously determined according to the relationships (FIG. 1) or (2) is calculated from a device-specific vibration value entered at the input part 42 into the dosimeter 2 and the prescribed triggering or exposure limit value.

When working with another implement, the dosimeter 2 is removed from the cordless hammer 6 and attached to the other implement. Then the device-typical vibration value of the other implement is input and determined by a reference measurement acceleration level in idle and in the working state and stored in the memory 20, whereupon the transmitter 18 determines the effective operating time of the other device and the previously determined effective operating time of the cordless hammer 6 added. As described above, a Be provided interface 44 for data transfer to a PC.

The illustrated in Figures 8 and 9, built into a wristwatch 50 Dosimeter 2 operates in a similar manner as the previously described, attachable to the device 4, 6 Dosimeter 2, except that the measured accelerometer 48 accelerations on the arm of the employee instead of directly measured on the device 4, 6, the display 26 is designed as an LCD display and the timer 16 is formed by a clockwork of the clock 50.

Claims

claims

1. Vibration dosimeter for determining the daily vibration load of persons who are exposed to mechanical vibrations at their workplace by the operation of a working means and in particular a hand-held electric tool, characterized by a detecting means (12, 18) for determining the effective daily operating time of the working means ( 4, 6), a computing device (22) for calculating a daily working time until reaching a prescribed exposure value or exposure limit of the vibration load from a typical work vibration value and the trigger value or exposure limit, and a comparison device (24) for comparing the determined effective daily operating time of the working fluid with the calculated daily working time until the prescribed action value or exposure limit value is reached.

2. Vibration dosimeter according to claim 1, characterized by a display device (26) indicating the exceeding of the prescribed exposure value or exposure limit of the vibration onsbelastung when the determined effective daily operating time of the working fluid (4, 6) in the working state, the calculated working time to Reaching the prescribed action value or exposure limit exceeds the vibration load.

3. Vibration dosimeter according to claim 2, characterized in that the display device (26) comprises at least two different colored light-emitting diodes (28, 30, 32).

4. Vibration dosimeter according to one of the preceding claims, characterized by means (34) for automatically resetting the determined effective daily operating time of the working means (4, 6) to zero after a predetermined interruption time of the operating time.

5. Vibration dosimeter according to one of the preceding claims, characterized in that it is integrated in a socket (36) for connecting an electric motor driven working means (4, 6) to a power supply network.

6. Vibration dosimeter according to claim 5, characterized in that the determining means (12, 18) determines the effective daily operating duration of the working means (4, 6) from the duration of the power consumption of the working means (4, 6) in the working state.

7. Vibration dosimeter according to one of claims 1 to 4, characterized in that it is incorporated or integrated in the working means (4, 6).

8. Vibration dosimeter according to one of claims 1 to 4, characterized in that it is on the working means (4, 6) fastened bar.

9. Vibration dosimeter according to one of claims 1 to 4, characterized in that it is integrated in a wristwatch (50).

10. Vibration dosimeter according to claim 8 or 9, characterized in that it comprises an acceleration sensor (48), and that the determining means (12, 18) determines the effective daily operating time of the working means (4, 6) in the working state by one of the acceleration sensor (48) compares the measured acceleration with a reference acceleration in working condition previously determined for the working medium (4, 6).

11. Vibration dosimeter according to one of the preceding claims, characterized by an input device (42) for inputting the typical vibration value of the working medium into the dosimeter (2).

12. A method for determining the daily vibration exposure of persons who are exposed to mechanical vibrations in their work by the operation of work equipment, characterized in that the daily effective operating time of the or each working fluid is determined in a working condition, and that the determined effective daily operating life of the work equipment (4, 6) is compared with a working time until the prescribed exposure value or exposure limit value of the vibration load is reached, whereby the working time until reaching the prescribed action value or exposure limit value is determined for a particular work equipment (4, 6 ) and the prescribed action value or exposure limit value.