1 Scope
This document specifies the design, safety requirements and verification methods for longitudinal load moment systems that can be used on rough terrain forklift trucks (hereinafter referred to as "forklift trucks"). This document specifies the requirements for longitudinal load moment indicators (hereinafter referred to as "LLMI") and longitudinal load moment controllers (hereinafter referred to as "LLMC"), as defined in ISO 10896-1, for use on rough terrain forklifts performing loading or placing functions in a smooth position on compacted, firm and level ground. The requirements of the Longitudinal Load Moment Indicator (hereinafter referred to as "LLMI") and Longitudinal Load Moment Controller (hereinafter referred to as "LLMC") for use on rough terrain forklift trucks performing loading or placing functions in a smooth position.
This document does not apply to the following forklift trucks:
truck-mounted forklifts as defined in ISO 20297-1; - slewing telescopic forklifts as defined in ISO 10896-2.
This document covers significant hazards, hazardous conditions or hazardous events relating to the use of longitudinal load moment systems in the manufacturer's intended use and misuse under foreseeable conditions.
This document does not cover risks arising from lateral instability or risks arising from instability caused by the operation of the forklift truck. The longitudinal load moment system does not have a function to alarm against the risk of overturning when the forklift truck is in operation.
This document does not apply to longitudinal load moment systems that were manufactured prior to the publication of this document.
2 Normative references
The contents of the following documents constitute essential provisions of this document by means of normative references in the text. Among them, note the date of the reference documents, only the date of the corresponding version applicable to this document; do not note the date of the reference documents, the latest version (including all the revision of the list) applicable to this document.
GB/T 16855.1--2018 Safety-related components of machine safety control systems, Part 1: General design guidelines (ISO 13849-1:2015, IDT)
GB/T 26949.14-2016 Stability verification of industrial vehicles, Part 14: Rough terrain telescopic forklifts (ISO 22915-14:2010,IDT)
GB/T 35205.1--2017 Safety requirements and validation for rough terrain forklift trucks Part 1: Telescopic forklift trucks (ISO 10896-1:2012,IDT)
3 Terms and definitions
The terms defined in ISO 12100, 1SO 10896-1 and the following terms and definitions apply to this document.
3.1
Longitudinal load moment
The sum of the moments generated by the load of the forklift truck, the attachments and the lifting device at the front of the tipping axis (e.g. wheels, stabilisers) in the longitudinal plane.
3.2
longitudinal load moment indicatoBibliographyr
LLMI
A device that warns the operator that the longitudinal load moment will exceed a preset limit due to changes in the load handling geometry.
3.3
longitudinal load moment control
LLMC
Device that prevents the operator from changing the load handling geometry in a direction that would cause the longitudinal load moment to exceed the permissible limit.
3.4
Load-handling geometry
The relationship between points, lines and angles described by the position of the centre of mass of the load (position of the boom, forks and attachments) and the tipping axis (front wheels or stabilisers, if fitted).
4 Safety requirements and/or protective measures/risk reduction measures
4.1 General requirements
4.1.1 The forklift truck shall comply with the safety requirements and/or protection/risk reduction measures in Chapter 4.
4.1.2 For non-significant hazards not covered by this document, the forklift truck shall be designed in accordance with the principles specified in ISO 12100. 4.2 Longitudinal load moment systems
4.2.1 General requirements
4.2.1.1 All practical performance and all construction of the longitudinal load moment system as described in the operating instructions provided by the manufacturer of the forklift truck shall comply with the safety requirements and/or protective measures in Chapter 4.
4.2.1.2 The following points shall be taken into account when designing the longitudinal load moment system;
the operating environment, e.g. relative humidity, temperature, condensation, dust; - the rated lifting capacity of the forklift truck
Electromagnetic compatibility;
Maintenance activities (e.g. cleaning, washing).
4.2.1.3 The design of the forklift truck shall take into account the dynamic loads generated by the operation of the LLMC.
4.2.1.4 The longitudinal load moment system shall be capable of withstanding shock loads and vibrations transmitted to the forklift truck during normal use and maintenance. 4.2.1.5 Paint or other corrosion protection shall not interfere with the proper function of the limiters and indicators.
4.2.2 Protection of calibration tuning modifications
All adjustments affecting the calibration adjustment of the longitudinal load moment system should be designed so that they can only be performed by authorised personnel (e.g. using special tools, special keys, operating procedures).
4.2.3 Verification of correct function
4.2.3.1 The verification of the correct functioning of the longitudinal load moment system shall be carried out without the use of any special tools. If a special procedure is required, this procedure shall be described in the operating instructions.
4.2.3.2 The longitudinal load moment system shall be capable of periodic function tests to verify proper system operation.
4.2.4 Early warning and prevention
The longitudinal load moment system shall comply with this document for all combinations of attachments approved by the manufacturer and for the movement of load handling devices and attachments.
4.2.5 Failure of the longitudinal load moment system
A fault or malfunction in any part of the system shall be such that the operator is alerted until the fault is eliminated (e.g. continuous flashing or continuous beeping of the alarm light or both).
4.2.6 Additional requirements for protection
In addition to the requirements of 4.4.2 of GB/T 35205.1-2017, components of the longitudinal load moment system exposed to severe operating conditions shall meet at least the minimum protection level of IEC 60529 equivalent to IP67.
4.2.7 Electrical
4.2.7.1 Power supply
4.2.7.1.1 The power supply shall be protected against voltage variations, forward and reverse supply voltage, overload, short circuit and earth.
4.2.7.1.2 In the event of a power failure, the longitudinal load moment LLMC system shall continue to operate normally or return to safe working conditions.
4.2.7.2 Voltage restoration
Unless the safe operating conditions are maintained, the longitudinal load moment system shall operate normally with voltage restored.
4.2.8 Interconnection of components
All transmission of signals and power between LLMI and LLMC components shall be protected against interference, e.g. discrete insulated conductors, Controller Area Network (CAN) bus. The frame of the forklift truck should not be used for the transmission of power, signals or for signal return functions.
4.2.9 External components
Components (e.g. proximity sensors) that are mounted on the outside of the forklift truck (i.e. do not require the removal of any guards or components) and that form part of the longitudinal load moment system shall be arranged and guarded in such a way as to minimise the possibility of interference.
4.3 Longitudinal Load Moment Indicator (LLMD)
4.3.1 General
The performance level requirements for LLMIs are not mentioned in this document and the general design guidelines for performance levels specified in GB/T 16855,1-2018 may be used, which are intended to warn the operator of possible hazards and require the operator to take action to prevent such hazards.
4.3.2 Alarms
4.3.2.1 The LLMI shall give continuous visual and audible alarms, each starting at its preset limit value and the limit value determined in accordance with GB/T 26949.14-2016 stability test T1. The alarm shall be continuous and persistent with the LLMC activated. The alarm signal shall continue until the longitudinal load moment returns to a value below the preset limit for the start of the alarm.
5 Verification of safety requirements and/or protective measures/risk reduction measures
5.1 General requirements
5.1.1 The requirements specified in chapter 4 shall be verified using one or a combination of the following methods:
Measurement;
Visual inspection; testing;
5.2 Validation
5.2.1 General requirements
5.2.1.1 The certification shall be carried out on a representative sample of each different type of forklift truck produced in batches with the longitudinal load moment system installed. The test shall be carried out with the forklift truck with wheels and with stabilisers (if fitted).
5.2.1.2 The LLMI and LLMC shall function properly and the forklift shall be stable at all times during and after the test.
NOTE: These tests may include overloading of the forklift truck and caution is necessary together with a suitable working regime.
5.2.2 Verification of LLMI
5.2.3 Verification of LLMC 5.2.3.1 Compliance of the LLMC with the requirements of 4.4 shall be checked for different loads and different reach, including the rated lifting capacity and maximum reach, according to the load profile.
5.2.3.2 The following test procedure shall be used:
a) Set the engine speed to a low idle speed;
b) Fully activate the descent control;
c) Accelerate the engine to maximum speed;
d) Allow the LLMC to stop descending at different take-off points.
5.2.3.3 After the LLMC has been triggered, it should be possible to place the load on the ground in safe conditions.
Note: Temporary lifting of the rear wheels is allowed during the test.
6 Information for use (operating instructions)
6.1 The manufacturer of the forklift truck shall provide information on the use of each longitudinal load moment system, including any special limits (e.g. manual control system) or requirements for proper operation of the system.
6.2 The operating instructions for the forklift truck shall specify the residual hazards of the longitudinal load moment system and contain the following information.
Bibliography
1 Scope
2 Normative references
3 Terms and definitions
4 Safety requirements and/or protective measures/risk reduction measures
5 Verification of safety requirements and/or protective measures/risk reduction measures
6 Information for use (operating instructions)
Bibliography
