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A combination hydraulic ram and impulse soil coring mechanism
J. ugric. Engng Res. (1982) 27, 465-467 RESEARCH NOTE
A Combination Hydraulic Ram and Impulse Soil Coring Mechanism M. A. FOALE*; C. E. G. Holy; C. EDSER~; T. DICKSON ;; M. E. MCKAY$ 1. Introduction A wide range of mechanical soil sampling rigs use a hydraulic ram to thrust in and withdraw soil coring tubes.’ These rigs provide a very rapid method for withdrawing tubes from the soil, but downward thrust is limited to the weight that can be applied to the ram. This weight can never exceed that of the vehicle carrying the ram, and thus can be too small for deep sampling in dry clay soil or in soil with layers containing gravel. This often applies even to soil cores of relatively small (50 mm) diameter. As costly additional weighting of the rig can only partly overcome this problem, alternative methods were sought. Enhanced downward thrust was obtained using large jack hammers with petrol motor/ pneumatic or electrical drive. 2 The jack hammer was mounted on the cylinder of a hydraulic ram. The rod was extended to the soil surface and the operator lowered the cylinder and hammer hydraulically as the corer penetrated into the soil. The ram also extracted the corer through a separate linkage from the mechanical hammer. Another rig2 used static thrust and impulse energy to drive coring tubes into the soil. Both the hammer and a heavy boom were attached to the cylinder of a ram. The boom extended from the linkage of a tractor so that half the weight of the boom was transmitted to the coring tube through the hammer. The availability of small hydraulic jack hammers has helped overcome some of the disadvantages of the above rigs. These disadvantages include the size of the hammer, its noise, and the initial and maintenance costs of additional pneumatic or electrical power supplies that are needed. A new rig using a hydraulic hammer is described in this note.
2. The design of a combined ram and hammer mechanism The mechanism is illustrated in Figs I and 2. A hydraulic jack hammer (B) was attached to the rod of a 75 mm dia 1.2 m 2-way hydraulic ram (A) mounted in a 2 m slotted box-section mast (G). A sliding horizontal plate that closely fitted the inside of the mast was bolted to the ram rod. The plate extended through the slotted side of the mast to a clamp (D) that was attached to the jack hammer. The mast was attached vertically to a vehicle with the base of the mast 0.5 m above the soil surface. The fully extended ram rod reached almost to the bottom of the mast. The jack hammer used was a Fairmont Universal Driver capable of striking 1200 blows/min, delivering 34 J/blow, when supplied with an oil flow of 19 l/min at IO.5 MPa. The moil point of the jack hammer (E) was flrmly shrink-fitted to a plug type anvil (F) which is held to the top of the coring tube by means of a horizontal pin. The ram and hammer were powered by a petrol motor driven oil pump with a flow rate exceeding 24 I/min. This allowed sufficient flow to extend the ram 1.2 m/min. ?? CSIRO Division of Tropical Crops & Pastures, Laws, Australia 4345 t Queensland Department of Primary Industries, Toowoomba, Australia 4350 $ Queensland Department of Primary Industries, Kingaroy, Australia 4610 § c/o M. E. McKay & Associates, Toowoomba, Australia 4350 Received 4 May 1982
465 OOZl-8634/82/050465 103 803.00/O
0 1982 The British Society for Research in Agricultural Engineering
466
COMBINED RAM/SOIL CSRER
A small 2-way hydraulic ram (K) fitted with a spiked stabilizing foot (H) was attached to the lower section of the mast to provide a link between the mast and the soil surface. This is extended when coring begins and bears the load of corer withdrawal by the main ram.
Fig. 1.
Fig. 2.
Fig. 1. The combination hydraulic ram andjack hammer mounted on a mobile frame. The components are: (A) main ram 75 mm x 1.2 m; (B) hydraulic jack hammer; (C) oil line to hammer; (D) clamp connecting hammer to the ram rod (not visible); (E) mail point of hammer; (F) plug-type steel anvil shrink-fitted to moil point; (G) mounting mast, (H)foot of stabilizing ram (not visible behind mast);(J) oil lines to stabilizing ram. The petrol motor that drives the oil pump, and a soil coring tube are visible on the left of the mast Fig. 2. Diagram of the sampling mechanism viewed side-on. Component lettering as for Fig. I plus (K), stabilizing ram; (L), coring tube; (M) ram rod
3. Soil sampling The soil corer is pushed in and pulled out of the soil by the main hydraulic ram. The hammer is used only if the rig begins to lift while the corer is being pushed into the soil. Depending on the weight of the rig and the nature of the soil, hammering may be needed only occasionally. The cutting edge of the corer can be damaged by hammering if obstruction to penetration is due to large stones. Experienced operators can avoid the damage by distinguishing between sudden impedance to penetration due to hard objects, and gradual slowing due to increasing soil resistance. Hammering can also aid in extracting cores as a few blows before withdrawal can free the core at its base, and also help remove air seals that develop in wet soil. The stabilizing foot not only prevents stress on the structure of the vehicle, but also prevents sideways slippage of the rig on sloping ground. Likewise, the stabilizing foot and hammer eliminate horizontal movement of the rig when cores are being taken at angles other than vertical. The hammer is used in such a way that the thrust action (and reaction) of the main ram is minimized. The new ram and hammer assembly, mounted on several different types of vehicle, has been tested over a wide variety of soils and soil conditions in northern Australia and it has overcome
467
M . A . F O A L E ET AL.
delays experienced with other methods of soil sampling. The hammer has been very useful in soils containing small roots of trees, and in those with hard pans or layers of gravel. The hydraulic hammer is quieter in operation and more robust than other types of jack hammer, and it has the great advantage that it is powered from the same oil pump as the main ram. This unit offers a significant improvement in cost, operating efficiency and versatility of mechanized soil coring equipment. REFERENCES ’ Foale,
M. A. Soil coring methods in crop and pasture research. CSIRO Divn of Tropical Crops and
Pastures, Brisbane, Australia, Techn. Memo No. 18, 1978 2 McKay, M. E. A versatile soil sampling system. Conf. Agric. Engng Toowoomba, 1978. The Institute of Engineers, Australia (Preprints of Papers), Natn. Conf. Publ. No. 78/S, 343-3, 1978
A Combination Hydraulic Ram and Impulse Soil Coring Mechanism M. A. FOALE*; C. E. G. Holy; C. EDSER~; T. DICKSON ;; M. E. MCKAY$ 1. Introduction A wide range of mechanical soil sampling rigs use a hydraulic ram to thrust in and withdraw soil coring tubes.’ These rigs provide a very rapid method for withdrawing tubes from the soil, but downward thrust is limited to the weight that can be applied to the ram. This weight can never exceed that of the vehicle carrying the ram, and thus can be too small for deep sampling in dry clay soil or in soil with layers containing gravel. This often applies even to soil cores of relatively small (50 mm) diameter. As costly additional weighting of the rig can only partly overcome this problem, alternative methods were sought. Enhanced downward thrust was obtained using large jack hammers with petrol motor/ pneumatic or electrical drive. 2 The jack hammer was mounted on the cylinder of a hydraulic ram. The rod was extended to the soil surface and the operator lowered the cylinder and hammer hydraulically as the corer penetrated into the soil. The ram also extracted the corer through a separate linkage from the mechanical hammer. Another rig2 used static thrust and impulse energy to drive coring tubes into the soil. Both the hammer and a heavy boom were attached to the cylinder of a ram. The boom extended from the linkage of a tractor so that half the weight of the boom was transmitted to the coring tube through the hammer. The availability of small hydraulic jack hammers has helped overcome some of the disadvantages of the above rigs. These disadvantages include the size of the hammer, its noise, and the initial and maintenance costs of additional pneumatic or electrical power supplies that are needed. A new rig using a hydraulic hammer is described in this note.
2. The design of a combined ram and hammer mechanism The mechanism is illustrated in Figs I and 2. A hydraulic jack hammer (B) was attached to the rod of a 75 mm dia 1.2 m 2-way hydraulic ram (A) mounted in a 2 m slotted box-section mast (G). A sliding horizontal plate that closely fitted the inside of the mast was bolted to the ram rod. The plate extended through the slotted side of the mast to a clamp (D) that was attached to the jack hammer. The mast was attached vertically to a vehicle with the base of the mast 0.5 m above the soil surface. The fully extended ram rod reached almost to the bottom of the mast. The jack hammer used was a Fairmont Universal Driver capable of striking 1200 blows/min, delivering 34 J/blow, when supplied with an oil flow of 19 l/min at IO.5 MPa. The moil point of the jack hammer (E) was flrmly shrink-fitted to a plug type anvil (F) which is held to the top of the coring tube by means of a horizontal pin. The ram and hammer were powered by a petrol motor driven oil pump with a flow rate exceeding 24 I/min. This allowed sufficient flow to extend the ram 1.2 m/min. ?? CSIRO Division of Tropical Crops & Pastures, Laws, Australia 4345 t Queensland Department of Primary Industries, Toowoomba, Australia 4350 $ Queensland Department of Primary Industries, Kingaroy, Australia 4610 § c/o M. E. McKay & Associates, Toowoomba, Australia 4350 Received 4 May 1982
465 OOZl-8634/82/050465 103 803.00/O
0 1982 The British Society for Research in Agricultural Engineering
466
COMBINED RAM/SOIL CSRER
A small 2-way hydraulic ram (K) fitted with a spiked stabilizing foot (H) was attached to the lower section of the mast to provide a link between the mast and the soil surface. This is extended when coring begins and bears the load of corer withdrawal by the main ram.
Fig. 1.
Fig. 2.
Fig. 1. The combination hydraulic ram andjack hammer mounted on a mobile frame. The components are: (A) main ram 75 mm x 1.2 m; (B) hydraulic jack hammer; (C) oil line to hammer; (D) clamp connecting hammer to the ram rod (not visible); (E) mail point of hammer; (F) plug-type steel anvil shrink-fitted to moil point; (G) mounting mast, (H)foot of stabilizing ram (not visible behind mast);(J) oil lines to stabilizing ram. The petrol motor that drives the oil pump, and a soil coring tube are visible on the left of the mast Fig. 2. Diagram of the sampling mechanism viewed side-on. Component lettering as for Fig. I plus (K), stabilizing ram; (L), coring tube; (M) ram rod
3. Soil sampling The soil corer is pushed in and pulled out of the soil by the main hydraulic ram. The hammer is used only if the rig begins to lift while the corer is being pushed into the soil. Depending on the weight of the rig and the nature of the soil, hammering may be needed only occasionally. The cutting edge of the corer can be damaged by hammering if obstruction to penetration is due to large stones. Experienced operators can avoid the damage by distinguishing between sudden impedance to penetration due to hard objects, and gradual slowing due to increasing soil resistance. Hammering can also aid in extracting cores as a few blows before withdrawal can free the core at its base, and also help remove air seals that develop in wet soil. The stabilizing foot not only prevents stress on the structure of the vehicle, but also prevents sideways slippage of the rig on sloping ground. Likewise, the stabilizing foot and hammer eliminate horizontal movement of the rig when cores are being taken at angles other than vertical. The hammer is used in such a way that the thrust action (and reaction) of the main ram is minimized. The new ram and hammer assembly, mounted on several different types of vehicle, has been tested over a wide variety of soils and soil conditions in northern Australia and it has overcome
467
M . A . F O A L E ET AL.
delays experienced with other methods of soil sampling. The hammer has been very useful in soils containing small roots of trees, and in those with hard pans or layers of gravel. The hydraulic hammer is quieter in operation and more robust than other types of jack hammer, and it has the great advantage that it is powered from the same oil pump as the main ram. This unit offers a significant improvement in cost, operating efficiency and versatility of mechanized soil coring equipment. REFERENCES ’ Foale,
M. A. Soil coring methods in crop and pasture research. CSIRO Divn of Tropical Crops and
Pastures, Brisbane, Australia, Techn. Memo No. 18, 1978 2 McKay, M. E. A versatile soil sampling system. Conf. Agric. Engng Toowoomba, 1978. The Institute of Engineers, Australia (Preprints of Papers), Natn. Conf. Publ. No. 78/S, 343-3, 1978