| Junttan Oy - Rental Impact Hammers | Print this page |
 Junttan introduced hydraulic impact hammers to the building and construction market in 1979. Since then, Junttan has remained the industry leader in hydraulic piling hammers, utilising in-depth co-operation with piling contractor company’s world-wide to ensure product development specific to industry demands and requirements. This co-operative approach, coupled with academic research and testing, has led to the following developments: 1. Junttan have determined that the 'optimum' impact velocity for driving concrete piles is slightly less than 5.0m/s. Impact above this velocity results in unacceptable damage to the pile head and inefficient transfer of energy to the pile; 2. A ram-block falling under gravity is the most reliable at delivering consistent energy. Ram-blocks which are accelerated are subject to too many variables such as temperature and pressure, which vary throughout the drive cycle as ambient climate conditions change - hence delivering inconsistent and highly variable energy.
i. The Junttan HHK "A"-series (max. drop height 1.200m) has an impact velocity of 4.85m/s. This is just below 5.00m/s, and is therefore perfectly suited to driving concrete piles; ii. The and HHK "S"-series (max. drop height 1.500m) has an impact velocity of 5.42m/s. This equates to 25% more energy at impact for the same ram-block mass as the equivalent HHK "A"-series hammer, with very little increase the overall equivalent hammer weight. The "S"-series are best suited to driving steel piles sections and "proof-testing" of concrete piles. (** The HHK "S"-series hammers can be used for driving concrete piles, but it is recommended to restrict the drop height to 1.200m, to keep the impact velocity below 4.85m/s).
Junttan HHK hydraulic impact hammers have been designed with a large ram block mass and large end area, combined with acceleration under gravity to ensure the highest possible efficiency of transfer of energy into the pile being driven. (Other competitor hydraulic hammers which are 'accelerated' utilise a lower ram block mass for similar 'potential energy' - i.e. immediately prior to impact. However, this lighter mass and smaller ram end area is less efficient at transferring energy into the pile being driven, and hence efficiency is reduced). Junttan also offers optional silencing on their hydraulic impact hammers (i.e. the HHK-AS and HHK-SS series, where the second "S" denotes silenced). Silencing includes : fully enclosed hammer frame; sound-absorbing rubber lining internally and externally on the hammer frame; double-walled sand-filled drive cap housings; neoprene impact piling cushion etc. These measures significantly reduce noise when compared to competitor impact piling hammers.
Junttan HHK_3-5AS (35kN.m/59kN.m) Spec Sheet.pdf Junttan HHK_7-9AS (82kN.m/106kN.m) Spec Sheet.pdf Junttan HHK 7/9SS (103kN.m/133kN.m) Spec Sheet.pdf Junttan HHK 10/12/14S (147kN.m/176kN.m/206kN.m) Spec Sheet;.pdf Junttan HHK 14/16S (206kN.m/235kN.m) Spec Sheet;.pdf |