This standard specifies the technical requirements, test methods, inspection rules and marking, packaging, transportation, storage, etc. of wheeled engineering machinery service brake system shoe brakes. This standard applies to the service brake shoe brakes of wheeled construction machinery such as wheeled cranes, loaders, scrapers, and backhoe loaders. JB/T 5949-1991 Technical conditions for shoe brakes of construction machinery JB/T5949-1991 Standard download and decompression password: www.bzxz.net

Machinery Industry Standards of the People's Republic of China
Construction Machinery Shoe Brakes
Technical Conditions
1 Subject Content and Scope of Application
JB/T5949-
91| |tt||This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of wheeled engineering machinery service brake system shoe brakes.
This standard is applicable to the service brake shoe brakes (hereinafter referred to as brakes) of wheeled construction machinery such as wheeled cranes, loaders, scrapers, and backhoe loaders.
2 reference standards
JB3935
Automobile brake performance requirements
JB/T 5937
JB/T5938
JB/T5944|| tt||JB/T5936
JB/T5943
JB/T 5945
JB/T5947
Construction machinery
General technical conditions for gray iron castings| |tt||General technical conditions for ductile iron castings
Construction machinery
Construction machinery
General technical conditions for heat treatment parts
Construction machinery
Construction machinery|| tt||Construction machinery
Construction machinery
JB8 product label
GB5763
GBn 257
JB2805
General technical conditions for machined parts
General technical conditions for weldments
General technical conditions for assembly
General technical conditions for packaging
Automotive brake linings
Automotive brake linings (appearance , Supplementary provisions on friction performance and impact strength) Automobile brake bench test method
GB 2828
Batch-by-batch inspection and counting sampling procedures and sampling tables (applicable to inspection of continuous batches) 3 Technical Requirements || tt||Brake products should comply with the provisions of this standard and be manufactured in accordance with product drawings and technical documents approved through prescribed procedures. If there are special requirements, they shall be implemented in accordance with the agreement between the user and the manufacturer. 3.1 Performance requirements
3.1.1 When the initial braking speed of the first, second and third brake effectiveness tests is 20km/h, and the brake pipeline pressure is the maximum value specified by the manufacturer, the braking torque output by the brake Should not be less than the rated value. 3.1.2 During the first, second and third efficiency tests, when the initial braking speed is 40km/h, the difference between the braking torque output by the brake and the braking torque output when the initial speed is 20km/h is calculated as a percentage. Should not be greater than 10%. 3.1.3 Other performance requirements of the brake should comply with the relevant provisions of JB3935. The performance requirements are shown in Table 1. 3.2 Materials
The materials used in the brake should have the official mark and certificate of production. The manufacturer should conduct sampling inspections. The Ministry of Mechanical and Electronics Industry of the People's Republic of China approved the implementation of 204
1992-07-01
on December 12, 1991 after confirmation.
3.3 accessories and purchased parts|| tt |
1
2
3
4
5
6
7
8|| tt||9
In the table:
th grinding contains
item
item
at V=30km/h, 0.30g (or Corresponding brake line pressure) t child ≤ 100℃
th performance
at p
pomax
th recession recovery
At 20km/h
At 0.45g (or corresponding brake line pressure) Uo. 40 km/h, 15 times
Vo=20 km/h, 10 times
The second performance
is at po= pa m+Uo=20 km/h
The second decline
is at 0.07g (or corresponding brake line pressure) = 20 km/h
times 60 times (gas), 18 times (fluid time
second run-in
at 0.30g (or corresponding brake line pressure) t#100 At ℃
Third performancebzxZ.net
At om, = 20 km/h
Third performance stability
At pa= pa nax
a. Brake
b. Brake drum inner surface
c. Brake base plate
d. Brake lining
e. Hydraulic cylinder (spindle cylinder)| | tt |
4(40-20),-(M2m-Mag)+M2X100%s /108% decay rate- [(M)mx \(M,>min]-(M.)mx × 100% core Complex difference rate [(M,)\(M.)x)÷(Ma)×100% decline rate ≤ 25%
recovery difference rate ≤ 120%!
M2=M||tt ||4(40-20)2 - (M 20--M.)-M 2X 100%*/10%] degree regression rate = [(M/)max—(Ma/)n] (M./) nar100%
Reduction rate≤60
50 running-in times (manual grinding is not allowed)
MaMm
4(40-20)=(Mg\-M,\ )--M \ |b. There should be no traces of scratches
c. No deformation that affects braking performance
d, intact, no delamination, slight cracks allowed, and firmly attached
c on the brake shoe, no oil leakage is allowed
The braking torque of the brake (which is the friction coefficient = 0.35 or the calculated value at the time of design), N+m: initial braking speed , km/h+
Brake disc temperature, C;
ho man
Maximum pipeline pressure specified by the manufacturer, MPa; Mar+Ma?.Mh?||tt| |In the first, second and third performance tests respectively, when the initial speed is set to 20km/h and the brake line pressure is the maximum value specified by the manufacturer, the braking torque (average braking force) output by the brake Moment), N·m; 205
JB/T 5949-91
4 (40--20), △ (40--20)24 (40-20)s--1 respectively The difference between the braking torque output by the brake when the initial braking speed is 40km/h and the braking torque output by the brake when the initial braking speed is 20km/h during the first, second and second efficiency tests. N. ms
M2, Mu, M2o, Ma. , Mz\, M\ - are the first, second and third efficiency tests respectively, the initial braking speed is 20km/h and 40km/h respectively, and the brake line pressure is the maximum specified by the manufacturer. value. The braking torque output by the brake, N+m#
(M.)-The maximum value of the braking torque in 15 times of fading braking.N·mM)in-15 times of fading braking Minimum value of torque.N·m Recovery difference rate-the difference between the maximum braking torque in 10 recovery tests and the braking torque (M,) with the same brake arm pressure in the first efficiency test.
3.4 ??Castings
3.4.1 Gray iron castings must comply with the technical requirements of the drawings and shall comply with the relevant provisions of JB/T5937. 3.4.2 Ductile iron castings must comply with the technical requirements of the drawings and shall comply with the relevant provisions of JB/T5938. 3.5 Machined parts
Machined parts must comply with the technical requirements of the drawings and shall comply with the relevant provisions of JB/T5936 Regulation. The technical requirements for the main parts of the brake are shown in Appendix A (Supplement). 3.6 Heat-treated parts
Heat-treated parts must comply with the technical requirements of the drawings and shall comply with the relevant provisions of JB/T5944. 3.7 Welding parts
Welding parts must comply with the technical requirements of the drawings and shall comply with the relevant provisions of JB/T5943. 3.8 Friction lining
must comply with the technical requirements of the drawing, and shall comply with the relevant regulations of GB5763 and GBn257. 3.9 Assembly
must comply with the technical requirements of the drawings and shall comply with the relevant provisions of JB/T5945. 3.10Appearance
3.10.1 The non-machined surface of castings and forgings should be smooth and free of sand and spurs. 3.10.2 The weld seams of welded parts should be smooth and free of defects such as welding slag. 3.10.3 Stamping parts should have no flash or burrs.
3.10.4 The surface paint should be evenly painted, and there should be no signs of sagging, full coating, or wrinkled skin. 3.11 Sealing
3.11.1 Static pressure test
The oil pressure is 1.3 times the oil pressure used by the brake assembly on the main engine (when the brake is used on different main engines, the maximum operating oil pressure is used). There should be no leakage in any part of the static test for 3 minutes, and the pressure drop should not exceed 0.3MPa. 3.11.2 Product sampling of sub-pumps
3.11.2.1 Outsourced sub-pumps
The number of inspection units of outsourced sub-pumps is determined from Table 2 of GB2828 (large sample size) based on the actual number of sub-pumps purchased in each batch. Elementary school code) Determine the sample size according to the special inspection level S-4, and inspect according to the requirements of Article 3.11.1. 3.11.2.2 Self-made sub-pump
Each sub-pump shall be inspected according to the requirements of 3.11.1. 3.11.3 The brake was tested together with the main engine for 1000 hours without leakage. 3.12 Reliability
Mean time between failures (MTBF) three 400h. 206
4 Test methods
4.1 Performance test
JB/T 5949--91
4.1.1 The first, second and third performance test, The initial speed is set as 10, 20, 30, 40km/h (each additional 10km/h is a level) to the maximum speed.
4.1.2 During the first, second and third efficiency tests, the hydraulic pressure gauge used for the brake under test is 4.90~11.80MPa, and each increment is 0.98 MPa.
4.1 .3 Before the first fade test begins, when the initial speed is 20km/h and 40km/h, and the initial temperature of the brake drum is 65C ± 5 (, adjust the input pipeline pressure so that the deceleration reaches 0.45g. 4.1. 4 For the second fade test, the initial braking speed is 20km/h. 4.1.5 During the brake bench test, the vehicle inertia with the largest brake usage is used as the test inertia. The calculation method of the rotational inertia is shown in Appendix 1H (Supplement). The test records and reports are shown in Appendix C (reference part). 4.1.6 Other bench tests of the brake should be carried out in accordance with the provisions of JB2805. 4.2 Reliability test
. MTBF=
In the formula; MTBF---Mean working time without failure, h; T total working time, h,
N
Faults that occur during the total working time Total number. 4.3 Other requirements shall be tested according to the provisions of 3.2~3.11. 5 Inspection classification
Inspection and type testing
5.1 Factory inspection
5.1.1 Each brake. Factory inspection should be carried out before leaving the factory. The inspection department of the manufacturer shall conduct inspection and acceptance according to the drawings, relevant technical documents and the provisions of this standard. 5.1.2 Factory inspection items
Assembly quality:
a.
Appearance quality;
b,
Sealing:
c
d.
Packaging quality .
5.2 Type test
5.2.1
5.2.2
a.
b.
c.||tt| |d.
Type testing should be approved by the industry quality inspection department. Type testing must be carried out when one of the following situations occurs: new product trial production;
The structure, process or material has been changed enough to affect the brake. Performance; mass-produced products are tested every four years; when the national quality supervision agency requests type testing. 5.2.3 Type test items:
a.
h.||tt| |&
Brake performance;
Reliability;
All factory inspection items;
207
d. Inspection of main components || tt||5.2.4 Product sampling
Product sampling shall be carried out according to the provisions of GB2828 5.2.4.1 Sampling method
9-91
JB/T 5949||tt| Without notifying the enterprise in advance, random sampling will be used among the products in the database of users or manufacturers. The products will be sealed immediately after sampling and shall not be adjusted, modified or replaced. 5.2.4.2 Inspection Level
Use special inspection level S-3.
5.2.4.3 Sampling quantity N
The brake performance should be tested on the bench from batch range N=915 in Taichung. Inspection of other items. Sampling from batch range N=91150 Taichung. There is no limit to the size of N when sampling among users. 5.2.4.4 Sample size code and sample size This standard stipulates that the sample size code for bench performance testing is A, and the sample size n is 2, that is, 2 brakes are selected for bench performance testing. It is stipulated that the sample size code for inspection of other items is C, and the sample size is n-5, that is, 5 brakes are selected for inspection of other items. 6 Marking, packaging, transportation and storage
6.1 Marking
6.1.1 The brake plate should be fixed in a visible position, and the plate should comply with the provisions of JB8 6.1.2 The plate includes the following content:
Manufacturer's name and label;
a.
b. Product name and model:
Factory number and year, month and day of manufacture.
c.
6.2 Packaging
6.2.1 Product packaging should comply with the relevant regulations of JB/T5947. 6.2.2
Product packaging should be moisture-proof and rust-proof. 6.2.3 When each product leaves the factory, it should be accompanied by the following technical documents: a.
b.
Product factory certificate;
Product accessories and spare parts catalog.
6.2.4 The following content should be marked on the outside of the packaging box: a.
h.
c.
d.
e.||tt| |f.
g.
Product model and name;
Product serial number and year, month and day of manufacture;
Manufacturer name and address;
Receiving unit and address,
gross weight and earned weight:
name of shipping and arrival station (port);
transportation and storage mark.
6.3 Transportation and Storage
When transporting and storing products, measures should be taken to prevent rain and moisture. 7 Quality Guarantee Period
Under the premise of complying with the storage and use requirements, Yongguang will be responsible for any defects in manufacturing quality or materials within 12 months from the date of delivery from the manufacturer (based on the date of delivery invoice). If it causes damage or fails to work properly, the manufacturer shall be responsible for free repair or replacement of the product in a timely manner. 208
JB/T 5949-.--
91
Appendix A
Technical requirements for main parts of main parts
(Supplement)|| The technical requirements for the main parts of tt||A1 are shown in Table A1. Table A1
Part name
Brake bracket
Camshaft
Brake drum
B1
Moment of inertia calculation||tt| |item
item
1. The center position of the installation screw hole to the inner circle of the bracket 2. The verticality of the axis of the pin hole to the positioning end face of the bracket 3. The verticality of the axis of the camshaft hole to the positioning end face of the bracket The verticality 4. The dimensional accuracy of the shoe pin hole
1. The symmetry of the axle tapered line
2. The cam journal coaxiality
1. Dimensional accuracy of positioning diameter
2. Surface roughness Rα value of positioning diameter
3. Dimensional accuracy of the brake friction surface
4. Surface roughness Ra value of the brake friction surface 5. Coaxiality between braking friction surface and positioning diameter Appendix B
Calculation method of moment of inertia
(supplement)
When both front wheels are tested for brakes at the same time, the calculation formula is as follows: B1 . 1 | | tt | |tt||G, --
---tire rolling radius.m;
β—front axle load transfer coefficient during no-load braking. B1.2. When only a single front wheel brake is tested, the calculation formula is as follows: Ie
where: Ir
G,Br2
2
When only a single front wheel brake is tested Moment of inertia during test, N·m2. β1+
where: - road adhesion coefficient;
hg.
height of center of gravity at unloaded transport position, m,
b.—distance between center of gravity and rear axle, m.
h
To
conform to the drawing
Ask
not to be greater than 0. 05 jμm
not to be less than 100: 0.03ml||tt ||IT?
Not less than 0.4μm
Not lower than g0.025μm
irg
3.2 μm
Conform to the pattern
3.2μm
not larger than 60.1um
(B1)
(B2)
(33)
209
model||tt ||Unladen transport position machine quality
Tire model
Axle load distribution:
Empty transport position, front
Full load transport position, front
Height of the center of gravity: when in the unloaded transport position
when in the fully loaded transport position
manufacturer
center of gravity position: distance from the rear axle in the unloaded transport position and distance from the rear axle in the fully loaded transport position Distance
Wheelbase
Brake type: front
Brake manufacturer
Brake drive mode: front
Brake wheel cylinder diameter: front||tt| |Maximum brake line pressure
Front and rear axle braking force ratio
Rated braking torque: front
rear
friction material grade
friction plate Clearance with brake drum: front
rear
brake fluid grade
Additional instructions:
--91
JB/T 5949-| |tt||Appendix C
Bench test records and reports
(reference parts)
Machine parameter and brake parameter table
Rolling radius
N
N
m
after
factory date
after
after
manufacturer
Manufacturer
After
After
This standard is proposed and centralized by the Tianjin Engineering Machinery Research Institute of the Ministry of Mechanical and Electronics Industry. Year and month of manufacture
Highest speed||tt| |Date of manufacture
Date of manufacture
This standard is issued by Tianjin Engineering Machinery Research Institute, Yingkou Engineering Machinery Clutch Factory, and Xuzhou Engineering Machinery Bridge Box Factory. The main drafters of this standard are Yang Xiuwen, Chen Shurong, and Wang Zhongru. 210
kg
m
N
N
ni
1
m
km/ h
M:t
N·m
N?m
mn
mm
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