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GB/T 21956.4-2009 English PDF

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GB/T 21956.4-2009: The strength testing method and accepting condition of protective structures on narrow-track wheeled agricultural and forestry tractors -- Part 4: Dynamic testing method of rear mounted ROPS
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GB/T 21956.4-2009	English	639	Add to Cart	3 days [Need to translate]	The strength testing method and accepting condition of protective structures on narrow-track wheeled agricultural and forestry tractors -- Part 4: Dynamic testing method of rear mounted ROPS	Obsolete	GB/T 21956.4-2009

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Basic data

Standard ID	GB/T 21956.4-2009 (GB/T21956.4-2009)
Description (Translated English)	The strength testing method and accepting condition of protective structures on narrow-track wheeled agricultural and forestry tractors -- Part 4: Dynamic testing method of rear mounted ROPS
Sector / Industry	National Standard (Recommended)
Classification of Chinese Standard	T69
Classification of International Standard	65.060.10
Word Count Estimation	16,110
Date of Issue	2009-03-05
Date of Implementation	2009-10-01
Quoted Standard	GB/T 700; GB/T 6236; GB/T 6960.7
Adopted Standard	OECD Code 7-2005, MOD
Regulation (derived from)	National Standard Approval Announcement 2009 No.2 (Total No.142)
Issuing agency(ies)	General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China
Summary	This standard specifies the agriculture, Dynamic test method and acceptance conditions forestry narrow track wheeled tractors-Rear -mounted guards. This section applies to a pneumatic tire tractor with two axes. Clearance its lowest point on the front and rear axle is not more than 600mm, with the front or rear tires of a larger size, either fixed or adjustable track, the track should not be greater than the minimum 1150mm, tractor unladen mass (including the largest manufacturer of tires and protective devices provided) is greater than 600kg, such as two-way traffic while the tractor should be less than 3000kg.

GB/T 21956.4-2009: The strength testing method and accepting condition of protective structures on narrow-track wheeled agricultural and forestry tractors -- Part 4: Dynamic testing method of rear mounted ROPS

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The strength testing method and accepting condition of protective structures on narrow-track wheeled agricultural and forestry tractors Part 4. Dynamic testing method of rear mounted ROPS ICS 65.060.10 T69 National Standards of People's Republic of China Narrow track wheeled agricultural and forestry tractors guard The strength testing method and acceptance conditions Part 4. Rear Dynamic testing method Posted 2009-03-05 2009-10-01 implementation Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China Standardization Administration of China released

Foreword

GB/T 21956 "narrow-track wheeled agricultural and forestry tractors guard strength test method and acceptance conditions" is divided into four parts. --- Part 1. Static testing method of front mounted; --- Part 2. Pre Dynamic testing method; --- Part 3. Static testing method of rear; --- Part 4. Rear dynamic test methods. This section GB/T Part of 421,956. The partial modification of the Standard Rules on the use of tests of agricultural and forestry tractors Official rules of the organization (OECD) 2005 enacted 7OECD Code7.2005 "narrow - track wheeled agricultural and forestry tractors - Rear-mounted roll-over protective strength testing method" in the dynamic test section. Wherein the same parts of the contents of the corresponding standards, citing the appropriate standards in place in China. According to this section OECDCode7.2005 redrafted. For ease of use, this section made the following editorial changes. --- "The Rules" be replaced by "this section"; "." --- With a decimal point instead of a comma as the decimal point, ""; --- Modify the standard name. This section of Appendix A normative appendix. This part is proposed by China Machinery Industry Federation. This part of the National Standardization Technical Committee under the jurisdiction of the tractor. This section drafted by. National Tractor Quality Supervision and Inspection Center. The main drafters of this section. Wang storm, Zhen, Jin Xiping. Narrow track wheeled agricultural and forestry tractors guard The strength testing method and acceptance conditions Part 4. Rear Dynamic testing method

1 Scope

GB/T 21956 provisions of this part of the dynamic test methods for agriculture, forestry narrow track wheeled tractors - Rear-mounted guards and inspection Closing conditions. This section GB/T 21956 is applicable to a pneumatic tire tractor two shafts, ground clearance is not its lowest point of front and rear axles To 600mm; on the front or rear wheels fitted with tires of a larger size, whether it is fixed or adjustable track width, which should be less than the minimum tread 1150mm; tractor idling quality (including the largest tire and guards provided by the manufacturer) is greater than 600kg, such as two-way travel trailer While drawing machine should be less than 3000kg.

2 Normative references

The following documents contain provisions which, through reference GB/T 21956 in this section constitute provisions of this section. For dated reference documents Member, all subsequent amendments (not including errata content) or revisions do not apply to this section, however, encouraged to reach under this section Parties to research agreement to use the latest versions of these documents. For undated reference documents, the latest versions apply to this section. GB/T 700 carbon structural steel (GB/T 700-2006, ISO 630.1995, Structuralsteels-Plates, wideflats, bars, sectionsandprofiles, NEQ) GB/T 6236 Tractors and machinery for agriculture and forestry seat landmarks (GB/T 6236-2008, ISO 5353.1995, Earth-mov- ingmachinery, andtractorsandmachineryforagriculturalandforestry-Seatindexpoint, MOD) GB/T 6960.7 Tractor terminology - Part 7. Cab, seat and cover

3 Terms and Definitions

GB/T 6960.7 and established the following terms and definitions apply to this part of the GB/T 21956 of. 3.1 At least self-propelled wheeled or tracked vehicles both axes, designed mainly for the following basic agricultural and forestry purposes. --- Tractor trailer; --- Carrying, pulling or pushing agricultural and forestry machinery or equipment, and according to need, or traveling in a tractor parked state is supporting Powered equipment. 3.2 3.2.1 The basic definition. the wheel center plane Wheel center plane is two away from the outer circumference of the rim plane equidistant plane. 3.2.2 Tread Vertical plane through the wheel axis line of intersection with the wheel center plane of the support plane turned at one point, if A and B points are tractor 2.2 wheels on the same axis so defined, the wheelbase is the distance between point A and point B is. This definition applies to the front and rear wheels. Correct Double wheels, two pairs wheelbase is the distance between the wheel center plane. 3.2.3 Additional definition. tractor center plane The tractor rear axle A and B points raised outermost limit position (which gives the maximum wheel base), and AB line perpendicular to the vertical midpoint Straight plane is the central plane of the tractor. 3.3 Obtained by the above definition of two straight lines AB (one for the front line, a line for the rear wheel) as two perpendicular planes, namely two wheelbase The distance between the planes.

4 units and measurement tolerances

Linear dimensions. ± 3mm Except for the following dimensions. --- Tire deformation ± 1mm --- Pendulum drop height of ± 1mm Quality. ± 1% Load. ± 2% Angle. ± 2 °

5 Symbol

B tractor outline the minimum width in millimeters (mm) B6 guard maximum outline width in millimeters (mm) The amount of deformation D guards at the impact point, in millimeters (mm) D 'is reached the theoretical amount of deformation energy of the guard, in millimeters (mm) Fv crushed vertical force in Newtons (N) H pendulum drop height, in millimeters (mm) H 'falling height when additional testing of the pendulum, in millimeters (mm) I centerline of the rear axle tractor reference moment of inertia about, nothing to do with the quality of the rear axle, in kilograms meters (kg · m2) Tractor reference wheelbase L, in millimeters (mm) Mt Tractor reference mass during strength test, as defined by the 6.5, in kilograms (kg) Test preparation 6 tractors and guards 6.1 according to GB/T 6236 to determine the position of the driver's seat landmarks. 6.2 protective device according to the technical specifications for mass production, the method according to the manufacturer's fixed on supporting the tractor. 6.3 tractor (or pilot plant) should be installed on all production components which may affect the strength or intensity of protective devices necessary for the test; can You can invade shelter area components should be installed to the tractor (or test device), in order to check whether these components meet acceptance 9.2 condition. 6.4 strength test, remove all trim and detachable non-structural components. 6.5 Tractor reference mass For calculating the height of the pendulum fall and crush force reference mass Mt at least for the quality of the tractor, excluding optional accessories, but we want to include Coolant, fuel, lubricants and guards brought tools. Tractor mass does not include the front and rear optional counterweight, tire weight, and other farm machinery His special parts.

7 Test procedure and requirements

7.1 Test Project and order a) after the impact test; b) After the crush test; c) before impact test; d) side impact test; Former e) crush test. 7.2 Test requirements 7.2.1 guard strength testing can select one of dynamic load test and static loading tests, the two are equivalent. 7.2.2 During the test, if any parts of the tractor breakage fixed or mobile, the test should be repeated. 7.2.3 During the test the tractor or protective devices may not be repaired or adjusted. 7.2.4 Test position after the first choice of the impact test, the test should be based on the views of the station, so that the guard under the most severe conditions Carrying position can be performed continuously impact. After the side impact and impact on both sides of the bearing location should be in the longitudinal center plane of the protective device; a pre-impact The position of the lateral impact protective device at the same side of the longitudinal center plane. 7.3 Pendulum 7.3.1 Application of two pendulum or catenary wire rope hanging from the ground not less than 6m suspension point (pivot), the pendulum should be adjusted independently Suspension mechanism between the height and angle of chain or rope hanging pendulum. 7.3.2 Quality pendulum should 2000kg ± 20kg. Quality does not include the mass of the pendulum or catenary wire rope. Quality or catenary wire rope Should not exceed 100kg. Impact surface length dimension of 680mm ± 20mm (see Fig. 1). After filling the pendulum should not maintain its centroid Variable and parallel to the geometric center of the hexahedron coincide. Figure 1 and the pendulum or catenary wire rope 7.3.3 pendulum can also be connected to a pull back its institutional and instantaneously released, this means not only an instantaneous release of the pendulum, further It should be able to prevent the pendulum swing of the pendulum about the vertical plane of the horizontal axis wobble. 7.4 After the impact test 7.4.1 Tractor positioning Tractor placement, should make the pendulum impact protection device, and the impact surface or catenary wire rope with a vertical plane Mt/100 (maximum To 20 °) angle. Guards at the point of impact with the vertical plane to form a larger angle if impact deformation, apply one additional support To adjust the impact surface so that it is parallel with the protective device in the maximum deformation at the point of impact at the moment, but the chain or rope hanging angle with the vertical plane still Maintaining the angle defined above. 7.4.2 the position of the point of impact The point of impact should be selected in the event of an accident when turning the guard position first hits the ground, usually on the edge. Pendulum centroid protective equipment Set the width of the upper portion of the vertical face at 1/6, this protective upper unit is located in the vertical plane of the outermost end of the center plane parallel to the tractor. 7.4.3 tractor fixed The test (Fig. 2), need 150mm × 150mm soft lumber to the top tight wheel; rope when under tension in all directions, tires Deformation of the tire wall (distance from the ground to the lowest point of the rim) height of 12%. 7.4.4 pendulum lifting height H = 2.165 × 10-8MtL2 (1) Or H = 5.73 × 10-2I (2) Figure 2 a schematic view of a tractor fixing method (after impact) 7.4.5 For tractors with two-way (two-way seat and steering wheel) Pendulum lifting height is the formula (1) and the equation (2) and (3) and the equation (4) is greater calculated. H = 25 + 0.07Mt (Mt≤2000kg) (3) H = 125 + 0.02Mt (Mt > 2000kg) (4) 7.5 After the crush test The load beam is placed on top of the rear guard member, so that the role of force in the tractor crushed center plane, applied crushed Force. Fv = 20Mt (5) Afterward, the force has been applied to the protective device no longer has any visible deformation maintained for 5s. When the guards can not afford all of the rear roof crush force, continue to keep up the pressure until the deformation of the roof and connected to the upper unit Protection Until coincide member and the plane overturned tractor capable of supporting the rear part of the constitution. This force is then lifted and the load beam shift The tractor when completely overturned tractor may prop guard the site, and then applying a crush force Fv. Test apparatus capable of exerting a downward force on the guard through the rigid beam width of 250mm, with a loading device coupled to the universal joint on. Chassis for proper support, so as not to overwhelm tractor tire receiving force.

3 crushed test bench schematic

7.6 front impact test 7.6.1 Tractor positioning According to the provisions of section 7.4.1. 7.6.2 the position of the point of impact The point of impact should be selected when the front row rollover accident guards hit the ground first position, usually on the edge. In the Anti-pendulum centroid Support for the upper unit vertical width at 1/6. 7.6.3 tractor fixed During the test, need 150mm × 150mm soft lumber to the top tight wheel; rope when under tension in all directions, the amount of deformation of the tire Tire wall (distance from the ground to the lowest point of the rim) height of 12% (see Figure 4). 4 tractor fixation diagram (before impact) 7.6.4 pendulum lifting height Pendulum lifting height is calculated according to the formula (3) and Equation (4). 7.6.5 For tractors with two-way (two-way seat and steering wheel) If the protective device is a two-column, the pendulum lifting height is calculated according to the formula (3) and formula (4); for other forms of protective equipment Set, pendulum lifting height is calculated by the formula (3) and the equation (4) and Equation (1) and the equation (2) the larger the calculated value. 7.7 side impact test 7.7.1 Tractor positioning Tractor placement, should make the pendulum impact protection device, impact surfaces and chains or rope hanging perpendicular. If the anti-impact deformation Angle protection device at the point of impact with the vertical plane than the vertical plane, and less than 20 °, then apply an additional support to adjust the impact surface so that Its maximum deformation at the point of impact at the moment with the protective devices in parallel, and the chain or rope hanging upon impact remains vertical. 7.7.2 the position of the point of impact The point of impact should be selected in the event of a rollover accident guards first hits the ground position, usually on the edge. 7.7.3 tractor stationary (see Figure 5) When the side impact test, the impact on the other side, the top tight end square wood floor, and the other end supported on the wheel rim. Figure 5 tractor fixation diagram (side impact) 7.7.4 pendulum lifting height H = 25 + 0.2Mt (Mt≤2000kg) (6) H = 125 + 0.15Mt (Mt > 2000kg) (7) 7.7.5 For tractors with two-way (two-way seat and steering wheel) For double-column guard pendulum lifting height using equation (6) and formula (7) and Equation (8) and Equation (9) calculation, taking the value is more Greater. H = (25 + 0.20Mt) (B6 + B)/2B (Mt≤2000kg) (8) H = (125 + 0.15Mt) (B6 + B)/2B (Mt > 2000kg) (9) For other forms of protective and pendulum lifting height using equation (6), Equation (7) calculation. 7.8 Test crushed before The load beam is placed on top of the guard in front of the member, so that the role of force in the tractor crushed center plane, applied crushed Force. Fv = 20Mt (10) Afterward, the force has been applied to the protective device no longer has any visible deformation maintained for 5s. When the guard can not afford the entire front portion of the roof crushed by force, continue to keep up the pressure until the roof deformation and connect the protective upper unit configuration Until coincide member and the plane overturned tractor capable of supporting the front part of the composition. This force is then lifted and moved to the load beam Tractor entirely possible support guards live tractor overturned when the site before applying crushed force Fv. Test device and crushed after similar tests. 7.9 Additional impact test In the impact test, the emergence of non-negligible cracking or tearing immediately after the second crash, the pendulum drop height. H '= (H × 10-1) (12 + 4 Rao) (Rao 2 + 1) -1 (11) Where. Rao --- is at the point of impact of the permanent deformation (Dp) and the elastic deformation (De) ratio. Rao = Dp/De (12) Permanent deformation of the second impact shall not exceed the first impact of permanent deformation of 30%. In order to perform additional tests, it is necessary to measure the elastic deformation during all the impact tests. Additional test 7.10 crushed In the crush test, the emergence of non-negligible cracking or tearing immediately after the second impact, crush force 1.2Fv. 7.11 inspection and measurement 7.11.1 fracture and crack inspection After each test all structural members shall be visually inspected, fittings, fasteners for breaks or cracks, non-essential parts appear small cracks Negligible and tear caused by the edges of the pendulum does not count. 7.11.2 shelter area check After each test and inspect the guard to see if there is any part of the invasion shelter area; you should also check whether the shelter area outside the guard The scope of protection. 7.11.3 lateral deformation measurement under elastic collision Measurement points should be located in the driver's seat at 900mm above the reference point, (see Fig. 6) in the vertical plane through the lateral loading point. 1 --- permanent deformation; 2 --- elastic deformation; 3 --- Total deformation (permanent deformation of the elastic deformation +). Figure 6 Schematic of measuring the elastic deformation 7.11.4 permanent deformation measurements After the final test overwhelmed, record permanent deformation guards. Therefore, it should be recorded with respect to the main components of the guard before driving test Position seat reference point.

8 shelter area

The tractor parked on level ground, if the steering wheel is adjustable, should be adjusted to the middle position, shelter zone (see Figure 7, Figure 8) by the following plane determine. Figure 7 Rear guard is a perspective view of shelter area Millimeters

8 rear side view of the protective device shelter area

9.4 7.11.3 elastic deformation according to the provisions of the measure should be less than 250mm. 9.5 should be free in the event of a rollover accident can seriously injure the driver or the driver's grip deformed parts. 10 applicability to other tractor models When tractors meet the acceptance criteria for other types of protective equipment, such as tractors and guard the following conditions, you do not have every Impact and crush tests carried out on models of tractors. 10.1 If the manufacturer apply only original test station to test the applicability of the power to approve guards. 10.2 new tractor does not exceed the energy required for the test test test required tractor 105% energy. 10.3 connection and tractor connection member and the same or other raw test of strength. Identical or provides the same support 10.4 fender or engine hood and other protective devices on the support member and the original trial. 10.5 seats in the guard position and exact size and dimensions of the relevant guard on the tractor, to ensure that in all trials, Shelter in the deformation zone guards. 10.6 The test report shall include the original test report, for reference. 11 minor changes Due to market conditions and tractor color, decals, make, model or non-structural sheet metal guards to make minor changes, issued Experimental Station of the original trial may represent official national representative body issued a "minor changes prove," stated all changes, and ensure the strength test results If affected, do not do the test. Drafting of test pieces proved under this rule, as an annex to the original report and meet industry requirements.

Appendix A

(Normative) Sample Test Report Note. This report uses the ISO 1000.1992 units specified; if necessary, the corresponding units in the back country indicated in brackets. --- Protective device manufacturer's name and address. --- Submit test unit. --- Guards grades. --- Guard model. Type --- guard. cab, anti-tilt racks. A. Technical parameters 1 test tractor A. 1.1 The test assembly guards tractor parameters A. 1.1.1 Tractors brands Model (trade name) Type. 2WD or 4WD; rubber or metal wheels (such as applications). A. 1.1.2 model or series. A. 1.1.3 Other technical parameters (such as the application) A. 1.2 Quality tractor assembly guard (no counterweight and driver) Table A. 1 Ago kg After kg Total kg Quality is used to calculate the impact energy and force to crush. A. 1.3 tractor tread and the moment of inertia Subjects tractor tread mm Rear impact energy is used to calculate the moment of inertia kg · m2 A. 1.4 tread and tire specifications Table A. 2 Minimum Tread mm Tire Specifications diameter pressure mm mm kPa A. 1.5 Tractor Seat Is there a bidirectional tractor driving position (two-way seats and steering wheel) Yes/No Seat Grade/model/type Optional seats and seat reference point. (Driver's seat and the seat Description 1 reference point) (2 seats and seat reference point described) (Description seats and the SRP) A. Technical data 2 guards A. 2.1 Details of the photo indicates that the installation (including fender) from the side and back A. 2.2 represents from the side and rear seat reference points and installation details of general arrangement A. 2.3 protective device consisting of a brief description. Structure type Installation Details Details and gaskets coverage Entry and escape method A. 2.4 Can tipping guard/Could Collapse A. 2.5 Dimensions Upon request, the installation of the seat plate and bowl behind by measurements. For installing the optional seat and two-way traffic (bi-directional seats and steering wheel) tractors, should be separately measured with respect to each of the driver's seat reference point Dimensions (SRP1, SRP2 etc.). A. 2.5.1 ceiling height from the seat reference point mm A. 2.5.2 ceiling from the floor of the driver's seat height mm A. 2.5.3 Width mm protective device in the driver's seat reference point A. 2.5.4 Reference point of the steering wheel at the wheel hub heigh...

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