1 Scope
This document specifies the test procedures and performance requirements for fall protection devices installed on agricultural or forestry tractors.
This document is applicable to agricultural and forestry tractors with at least two axles equipped with pneumatic tires or caterpillar instead of tires. This document is not applicable to forestry machinery defined in GB/T19365.
2 Normative References
The contents in the following documents, through normative references, constitute indispensable provisions of this document. Among them, only the version corresponding to the date of reference is applicable to this document; For undated references, the latest version (including all amendments) is applicable to this document.
GB/T 229 Metallic Materials Charpy Pendulum Impact Test Method (GB/T 229-2020, ISO14811:2016, MOD)
GB/T 3098.1-2010 Mechanical Properties of Fasteners Bolts, Screws and Studs (ISO898-1:2009, MOD)
Note: There is no technical difference between GB/T 3098.1-2010 and ISO898-1:2009.
GB/T 3098.2-2015 Mechanical Properties of Fasteners Nuts (ISO 898-2:2012, MOD)
Note: There is no technical difference between GB/T 3098.2-2015 and ISO 8982:2012.
GB 3100 International System of Units and Its Application
GB/T 7121.1-2008 Strength Test Methods and Acceptance Conditions for Guards of Agricultural and Forestry Wheeled Tractors Part 1: Rear mounted Static Test Method (ISO 5700:2006, MOD)
Note: There is no technical difference between GB/T 7121.1008 and ISO5700:2006.
GB/T 7121.2-2008 Strength Test Methods and Acceptance Conditions for Guards of Agricultural and Forestry Wheeled Tractors Part 2: Rear mounted Dynamic Test Method (ISO 3463:2006, MOD)
Note: There is no technical difference between the contents quoted in GB/T 7121.2-2008 and those quoted in ISO3463:2006.
GB/T 17922 Earth moving machinery - Laboratory tests and performance requirements for rollover protective structures (GB/T 17922-2014, ISO3471:2008, IDT)
GB/T34560.1 Structural Steel Part 1: General Technical Delivery Conditions for Hot Rolled Products (GB/T 34560.1-2017, ISO630-1:2011, MOD)
ISO12003-1:2011 Agricultural and forestry tractors Roll over protection device for narrow track tractors Part 1: Front mounted
ISO12003-2:2021 Agricultural and forestry tractors Roll over protection device for narrow track tractors Part 2: Rear mounted
3 Terms and definitions
The following terms and definitions apply to this document.
three point one
Agricultural and forestry tractor
Wheel type or crawler type with at least two axles, specially used for towing agricultural trailers and for towing, pushing, carrying and driving can be equipped with detachable
Self propelled agricultural vehicles for unloading and loading agricultural and forestry machines and tools on the platform.
Note 2 The maximum design speed of agricultural vehicles is not less than 6 km/h, and one or more seats can be equipped.
three point two
Falling object protective structure; FOPS
A structural device that provides reasonable protection for the driver in the driving position against falling objects.
three point three
Roll over protective structure; ROPS
Protect the frame structure (safety cab or frame) of the agricultural and forestry tractor driver to avoid or reduce the possibility of driver injury due to rollover accident during normal operation.
Note: ROPS is represented by the space of the shelter area. The space consists of a series of connecting lines from the containment area of the structure or the outermost edge of the structure to the parts where the tractor may contact the ground. These parts can support the tractor when the tractor is in the rollover position.
three point four
Safetyzone
An area that provides protection for the tractor driver.
Note: The safe zone depends on the selected ROPS file. For tractors installed with ROPS complying with the test provisions of GB/T 7121.1-2008, GB/T 7121.22008, ISO 12003-1:221 or ISO 120032:221, the safety zone is the shelter area specified in these documents. For tractors installed with ROPS conforming to the test provisions of GB/T 17922, the safety zone is the deflection limit (DLV) specified in GB/T 17772.
4 Allowable error of measured value
± 5% or ± 1mm of the maximum displacement deformation. ± 0.5% mass.
5 Test preparation
5.1 Preparation for tractor and FOPS test
5.1.1 Whether the FOPS is manufactured by the tractor manufacturer or an independent company, the test shall be valid only for the tractor model under test. On the one hand, FOPS of each type of tractor should be retested. However, for tractor models derived from the original model by changing the engine, transmission, steering gear and front suspension (see Chapter 9), the testing agency can prove that the strength test is also effective. On the other hand, multiple FOPS can be tested for the same type of tractor.
5.1.2 The falling object protective device used for the test (hereinafter referred to as the "protective device scoop") shall at least include all components that transfer the load from the impact position of the falling test object to the safe area. The protective devices used for the test are as follows:
a) It is rigidly connected to the test bench at the normal installation position (see Figure 1);
b) The tractor chassis is rigidly connected to the test floor by any bracket, fastener or suspension used for normal production, and other tractor components that may be affected by the load imposed by the protective device, which are normally connected to the tractor chassis [see Figure 2a) and Figure 2b)].
5.1.3 FOPS can be designed to protect the driver only when objects fall onto the tractor, but it can also be equipped with more or less temporary weatherproof devices for the driver on the protective device. The driver usually removes it when the weather is warm. In addition, some FOPS covers are permanent and provide ventilation through windows or air outlets when the weather is warm.
5.1.4 As the covering layer can increase the strength of FOPS, and there may be no removable covering layer in case of falling objects, all components that can be removed by the driver shall be removed for test purposes. During the test, the openable doors, skylights and windows shall be removed or fixed in the open position to avoid increasing the strength of FOPS. Attention shall be paid to whether falling objects at this location will cause danger to the driver. If the FOPS has an openable sunroof and is part of the protective device, the test shall be conducted in both open and closed positions.
5.1.5 The FOPS test shall include the cover that cannot be removed during normal tractor operation. The instructions shall include a description of any temporary covers provided.
5.1.6 All glass or similar brittle materials shall be removed before the test. Tractor and ROPS components that may be damaged during the test but do not affect the strength of the FOPS or its dimensions may be removed before the test, if permitted by the manufacturer.
5.1.7 No maintenance or adjustment shall be carried out during the test. If multiple falling object tests are required, the manufacturer may provide multiple identical samples.
5.1.8 If the same protective device is used for FOPS and ROPS assessment, FOPS test shall be prior to ROPS test (according to GB/T7121.1-2008, GB/T7121.2-2008, GB/T17922, ISO12003-1:2011 or ISO12003-2:2011). It is allowed to remove the impact dent or replace the FOPS cover.
5.2 Test equipment and procedures
5.2.1 Equipment
5.2.1.1 The falling object shall be a solid steel ball or a ductile iron ball, as shown in Figure 3. During the test, its impact surface shall have the characteristics of preventing deformation. The typical mass of the falling object shall be 45kg, and the diameter of the contact surface of the sphere shall be 200mm and 250mm
5.2.1.2 Equipment for lifting falling objects to the specified height.
5.2.1.3 Equipment that releases falling objects to make them fall freely.
5.2.1.4 Hard plane that will not be hit by equipment or test bench under the load of falling object test.
s. 2.1. s' The method to determine whether FOPS enters the safety zone during the falling object test. It can be one of the following situations:
The vertically placed safety zone template is made of materials showing FOPS breakdown. In this case, the lower surface of FOPS cover can be coated with grease or other suitable materials to show such breakdown;
The dynamic instrument system with sufficient frequency response will display the expected deformation of FOPS relative to the safety zone. The top area of the safety area is defined by the following parts: points I1, A1, B1, C1, C2, B2, A2 and I2 of the shelter area in GB/T7121.1-2008 and GB/T7121.2-2008; Plane p described in 6.2 center and e) of ISO12003-1:2011 is determined by ISO12003-2:2011
The surface defined by points H1, A1, B1, C1, C2, B2, A2 and H2 in, and the top of DLV in GB/T17,922. If the tractor can travel in both directions (two-way seats and steering wheel), the safety zone shall be the envelope of two DLVs defined at two different positions of the steering wheel and seat.
5.2.1.6 If there is a safety zone template, it shall be fixed on the same part of the tractor connected to the driver's seat and shall remain unchanged throughout the test.
5.2.2 Test procedures
5.2.2.1 Place the falling object (see 5.2.1.1) on the upper part of FOPS at the position specified in 5.2.2.2.
5.2.2.2 The impact location shall be within the vertical projection area of the upper surface of the safety area. When the safety zone is represented by the shelter area, the impact point shall be located at the farthest position from the main structural members (see circle). When the safety zone is represented by DLV, the impact position shall be completely located in the vertical projection area of the upper safety zone of FOPS, directly above the DLV.
b) Case 2: The main horizontal members of the upper FOPS are located in the vertical projection area of the upper FOPS safety zone. If the thickness of the covering material is uniform in all surface areas above the safety area, the center of the test object shall be located in the surface of the largest area, which is the vertical projection area of the safety area, excluding the main horizontal components above the FOPS. The center of the test falling object shall be located at the point within the surface of the largest area closest to the upper center of the FOPS (see enclosure).
5.2.2.3 No matter whether the safety area is represented by shelter area or DLV, if different materials or materials of different thickness are used in different areas above the safety area, each area shall be subject to falling object test in turn. If multiple falling object tests are required, the manufacturer can provide multiple identical FOPS samples (or part of them) (one for each falling object test). If design features (such as the opening of windows or equipment, or changes in the thickness of covering materials or materials) indicate a more vulnerable position in the vertical projection of the safety zone, the falling object position shall be adjusted to this position. In addition, if the opening on the FOPS cover is to be filled with devices or equipment to provide adequate protection, these devices or equipment shall be installed in place during the falling object test.
5.2.2.4 Lift the falling object vertically above the position specified in 5.2.2.1 and 5.2.2.2 to a height sufficient to generate 1365J of energy.
5.2.2.5 Release falling objects to make them fall onto FOPS without restriction.
5.2.2.6 Since it is unlikely that the free falling object will accurately impact the position specified in 5.2.2.1 and 5.2.2.2, the deviation is limited at the foot of the mountain:
a) The impact of falling objects shall be completely within a circle with a radius of 100mm, and its center shall coincide with the vertical centerline of falling objects specified in 5.2.2.1 and 5.2.2.2;
b) The position and attitude of the subsequent impact caused by the rebound are unrestricted.
6 Performance Requirements
6.1 During the first or subsequent impact of the test falling object, no part of the protective device or falling object shall enter the safe area.
6.2 After falling object test, FOPS shall completely cover the vertical projection of the safety zone.
6.3 Falling objects shall not penetrate FOPS
7 Low temperature performance of protective device
If the protective device is declared to be capable of resisting low-temperature brittleness, the manufacturer shall give specific details in the test report. The embrittlement characteristics in cold weather shall be verified in accordance with the test specified in Chapter 5 at a temperature not higher than 18 ℃, or in accordance with Appendix C.
8 Identification
8.1 Labels are optional. The label shall at least include the following contents:
a) Name and address of the manufacturer of the protective device;
b) Number of protective device (design or serial number);
c) Make, model or serial number of the tractor fitted with the guard;
d) Energy level reached by the test
e) Number of this document.
8.2 The label shall be durable and permanently fixed on the protective device to make it easy to identify and protect it from environmental damage.
9 Test report
Test report shall be provided. The format of the approved test report shall comply with Appendix D. If different test report formats are used, the information required in Appendix D shall be included as a minimum.
Appendix A (Informative) Main Technical Changes between the Document and GB/T 24644-2009
Appendix B (informative) List of comparison between this document and ISO 27850:2013 structure number
Annex C (normative) Optional requirements for resistance to brittle fracture of FOPS at reduced operating temperature
Appendix D (normative) FOPS test report
Bibliography
Contents
1 Scope
2 Normative References
3 Terms and definitions
4 Allowable error of measured value
5 Test preparation
6 Performance Requirements
7 Low temperature performance of protective device
8 Identification
9 Test report
Appendix A (Informative) Main Technical Changes between the Document and GB/T 24644-
Appendix B (informative) List of comparison between this document and ISO 27850:2013 structure number
Annex C (normative) Optional requirements for resistance to brittle fracture of FOPS at reduced operating temperature
Appendix D (normative) FOPS test report
Bibliography
