Composed of multiple leaf springs, the sprung drawbar improves the ride comfort of the agricultural trailer and reduces stress on the tractor hitch. It is especially suitable for high-capacity agricultural trailers used to transport goods over long distances on the road.
When installing the sprung drawbar, use 3 U-bolts to install on the 20mm thick drawbar base plate. The top of the drawbar is further reinforced with an additional saddle at the pivot at the front of the chassis. The front pivot tube with phosphor bronze bushing is set at the top of the drawbar with easy-to-access lubrication points.
A leaf spring is the most widely used elastic element in automobile suspensions.
It is an approximate equal strength steel beam composed of several alloy spring sheets of equal width and unequal length. Its main function is to transmit all forces and moments between wheels and frames, relax impactive load caused by the road surface and realize vehicle guidance, make vehicles normal drive.
Leaf springs are widely applied to suspensions for heavy duty trucks, light duty trucks, pick-ups, cars, skeletal trailers, lowbed trailers, flatbed trailers, oil tank trailers, van trailers, wood transport trailers, gooseneck trailers, agricultrucal vehicles, etc. Classification of Leaf Springs include Conventional leaf springs, parabolic leaf springs, Z type air linkers, TRA leaf springs, trailer leaf springs,light duyt trailer spring, boat trailer springs, pickup leaf springs, semi trailer springs, truck springs, farming/agricultural trailer springs, sprung drawbar, bus springs, bogie/boogie springs, heavy truck springs, etc.
For more about WONDEE Leaf Springs Project, please click：
|QC management system||Implementing IATF 16949-2016|
|Services quality management system||Implementing ISO 9001-2015|
|Product technical standards||Implementing GB/T 19844-2018, GT/T 1222-2007|
|Warranty||12 months since shipping date|
|Quality testing by||Stiffness Testing Machine, Arc Height Sorting Machine, and Fatigue Testing Machine, etc.|
|Raw material||Top 3 steel mills in China|
|Flat bar cutting & center hole punching||By fully automatic CNC cutting & punching production line|
Center hole positioning tolerance: <±0.2 mm
Cutting length tolerance: <±2 mm
|Leaf spring eye rolling||Use automatic CNC leaf eye rolling machines, robot assistance, dedicated molds and toolings to guarantee below features:|
1) Perpendicularity tolerance <1% x leaf width
2) Parallelism tolerance< 1% x leaf width
3) Eye diameter tolerance<±0.5 mm
4) Width tolerance of leaf end: -0.5mm ~ 0 mm
|Leaf tapering/parabolic rolling||Use automatic CNC parabolic taper rolling machines, robot assistance, dedicated molds and toolings to guarantee below features:|
1) Taper thickness allowance: <±0.25mm
2) Width tolerance of leaf end: -0.5mm~0 mm
|Heat treatment lines||1) Heating line: |
The large-scale automatic CNC temperature control heating furnace not only ensures the heating time but also ensures that the temperature in the furnace reaches the design value (the temperature difference is within ±5 degrees), ensures that the leaf springs are heated evenly, and avoids excessively high or low temperatures, thereby ensuring the strength of the leaf springs and the service life limit meets the Crequirements.
2) Quenching & camber making line:
Use special CNC quenching equipment, mechanical oil, camber making machines and robot assistance to ensure that the quenching temperature, quenching time and cambers reach the design requirements.
3) Tempering line:
A dedicated CNC tempering production lines are used to ensure that the tempering temperature and the tempering time meet the design requirements.
So as to ensure the strength and service life of leaf springs.
|Camber tolearance (mm)||≤±6 (Exceed spring industry standard ±7)|
|Fatigue life (cycles)||>120,000+( Exceed spring industry standard 100,000 cycles)|
|Shot peening||Using special leaf spring shot blasting machines, the new and used steel shots are mixed for use. On the one hand, the new steel shots increase the deformation of the springs. On the other hand, the used steel shots have no edges and corners to avoid microcracks on the surface of the springs, thereby increasing the fatigue life.|
|Painting||Normal painting and E-coating are available.|
*E-coating finish line: paint film is uniform and plump, with strong adhesion and high anti-corrosion performance, to avoid dripping, flow marks, stagnation marks and other problems.
* Salt spray test >100 hours
* Clients' logo are supported
* Design marks or stickers for clients, free of charge
|Other inspection equipment||*Metallographic Microscope,|
*Carbon & Sulfur Combined Analyzer, and
*Hardness Tester, etc.
|Oversea sales volume (tons)||14,000+|
|Overseas market||30+ countries ( German, France, Poland, Portugal, Russia, Filand, USA, Canada, Mexico, Thailand, Vietnam, Malaysia, Singapore, The Philippines, Indonesia, Brazil, Bolivia, Argentina, Ecualor, Chile, Peru, Guatemala, Panama, Egypt, South Africa, Nigeria, Tanzania, etc)|
|Land area (square meters)||30,000+|
|Tons of annual output||35,000+|
|Number of equipments (sets)||200+|
|Number of employees||260+|
|Number of engineers||10+|
|Available certificates||COC, PVOC, CIQ, SONCAP, BV, C/O, FORM E, FORM A.|
Comprehensive Info of Leaf Spring:
|Leaf spring types||Conventional leaf springs, parabolic leaf springs, Z type air linkers, TRA leaf springs, trailer leaf springs, boat trailer springs, pickup leaf springs, semi trailer springs, truck springs, farming/agricultural trailer springs, sprung drawbar, bus springs, bogie/boogie springs, heavy truck springs, light duty trailer springs/small springs, etc.|
|Materials grade:||SUP7, SUP9, SUP9A, SUP10, SUP11, SUP11A and SUP12|
60Si2Mn, 55CrMnA, 60CrMnBA, 50CrVA, 60CrMnBA, 60Si2CrA
61SiCr7, 55Cr3, 60CrB3, 51CrV4
9260, 5155, 5160, 6150, 51B60, 9254
|Spring width range (mm)||44.5~125 mm|
|Spring thickness (mm)||6~50 mm|
|Interchangeable brands (make)||MERCEDES BENZ, BPW, VOLVO, TOYOTA, HONDA, NISSAN, MAN, HOWO, SCANIA, RENAULT, DAF, MAN, ISUZU, IVECO, SISU, HYUNDA, TATRA, MAZ, SAF, ROR, FRUEHAUF, HINO, YORK, FUWA, CIMC, ETC.|
|Colors||Red, shinning black, dark black, grey, blue, as required.|
|Optional parts, components, & related parts||Centor bolts, clamps, |
Copper bushes, bi-metal bushes, steel rubber bushings, rubber bushes, nylon bushes.
U-bolts, brackets, pins.
|Package||Fumigated wooden pallets, steel pallets, as required.|
|Standards implemented||IATF 16949-2016, ISO 9001-2015, GB/T 19844-2018, GT/T 1222-2007|
|Payment terms||TT, LC, DP.|
|Lead time||About 25~35 working days.|
Agricultural Sprung Drawbar Trailer Springs
|Spring Material Section Size||Qty of Total Leaf||Centre of Eye to Centre of C/Bolt||Centre of C/Bolt to End of Spring||Centre of Eye to End of Spring||Inner Diameter of Bush|
|Parts No.||Section Size||Leaves||Capacity||A||B||L||ID1|
|WLS1201407N01||120 x 14||7||1800||870||100||970||45|
|WLS1201409N01||120 x 14||9||2500||870||100||970||45|
|WLS1201411N01||120 x 14||11||2900||870||100||970||45|
|WLS1201413N01||120 x 14||13||3300||870||100||970||45|
|WLS1201415N01||120 x 14||15||3920||870||100||970||45|
Components of sprung drawbar:
U-bolt supplied with nylon nuts
1. M24x2x121x170/190/220 for 7/9/11 Leaves Drawbar Springs
2. M30x2x121x260/280 for 13/15 Leaves Drawbar Springs
Note 1: Other leaf springs for agricultural trailers are available;
Note 2: Other classification of leaf spring are available, include: conventional leaf springs, parabolic leaf springs, Z type air linkers, TRA leaf springs, trailer leaf springs, light duyt trailer spring, boat trailer springs, pickup leaf springs, semi trailer springs, truck springs, farming/agricultural trailer springs, sprung drawbar, bus springs, bogie/boogie springs, heavy truck springs, etc.
About production processes of leaf springs, please kindly visit YOUTUBE link:
Workshops of WONDEE Autoparts leaf springs :
(Flat bar workshop, production processing workshop, leaf spring assembly workshop, leaf spring finished production)
Processes & equipment of WONDEE Autoparts leaf springs :
(1. Flat bar cutting and hole punching→ 2. Spring ends processing→ 3. CNC automatic eye rolling→ 4. Spring heating→ 5. Spring quenching→ 6. Spring tempering→ 7. Spring shot peening→ 8. Leaf spring assembling→ 9. Spring e-painting)
QC equipment of WONDEE Autoparts leaf springs :
(Material Metallographic analysis, spring spectral analysis, raw material inspection, eyes inspection, spring camber inspection, spring hardness test, salt spray test, fagigue life test, spring rate test)
Warehousing & Logistics of WONDEE Autoparts leaf springs:
(Sprung drawbar finished prodution, spring packing, spring warehousing, leaf spring container laoding)
Other spring types of WONDEE Autoparts leaf springs:
Components & spare parts of WONDEE Autoparts leaf springs
(Bi-metal bushings, Composite bushes, Rubber bushes, Center bolts, Spring pins, Leaf spring hangers, Spring brackets, Spring steel flat bars)
In addition to supplying leaf springs, WONDEE Autoparts also supply different types of semi trailer components as below: