Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/22—Hydraulic or pneumatic drives
  • E02F9/2203—Arrangements for controlling the attitude of actuators, e.g. speed, floating function
  • E02F9/2207—Arrangements for controlling the attitude of actuators, e.g. speed, floating function for reducing or compensating oscillations

Definitions

• This invention relates to an apparatus for mobile machines, preferably tractors provided with a loading unit, which is vertically adjustable by means of at least one hydraulically operable lifting cylinder, which comprises a piston means and is an integral part of a hydraulic system in the machine, the apparatus being intended to damp the vibrations which may arise in the loading unit when the machine travels on fields and on a bumpy road or when using the machine at work.
• Tractors provided with loading units are common in the market. These machines as a rule have a loading unit provided with two hydraulic cylinders and comprising for instance of forks or a bucket by means of which it is possible to load or unload goods and to move goods between two points. In the later case this transport of goods may involve transportation a long distance along a bumpy road. Therewith there arise strong swingings in the machine if this one should drive into a pit. These swingings become stronger if the loading unit carries a load of any kind. Since the lifting cylinders of the loading unit during transportation on a road are locked in the certain position, there arise heavy loads on the loading unit when the machine drives into a pit, which loads are directly transmitted to the chassis of the loading machine and therefrom to the wheels of the loading machine.
• the solution of the mentioned problem is composed of an apparatus of the kind mentioned by way of introduction, which is characterized in that it comprises the combination of the following features: -
• the mentioned lifting cylinder is double-acting, i.e. it can activate the hydraulic medium both on its piston side and the side of the piston rod;
• fig. 1 is a connection diagram for a hydraulic system of which the new apparatus is an integral part
• fig. 2 shows the application of the new apparatus on a portion of a loading machine.
• fig. 1 is shown there schematically the new invention, which according to this embodiment has two parallel-connected, hydraulically operable lifting cylinders 1, 2, which number of cylinders is very common when using vertically adjustable loading units on loading machines.
• control valve 5 which is partly connected with a hydraulic oil pump 6, partly with a hydraulic oil tank 7.
• the mentioned control valve can in a known way be regulated by means of a hand lever in the driver's cab of the loading machine when raising and lowering the loading unit and is held in an inactive neutral position, when the loading machine is travelling on the road.
• the plus sides of the two lifting cylinders 1, 2 are connected with two accumulators 8, 9 via a central conduit 10, which is divided into two conduits 11, 12, each of which going to one accumulator.
• conduit 11, 12 is a throttling means 13, 14 arranged, the purpose of which is to brake the flow to respective accumulator and by that to damp the movement of the loading unit.
• a throttling means 13, 14 arranged, the purpose of which is to brake the flow to respective accumulator and by that to damp the movement of the loading unit.
• the conduit 16 is provided with a throttling means 17 which is positioned prior to the accumulator 15 and has the same function as the throttling means 13,
• fig. 2 is shown an embodiment of the apparatus according to the invention fastened on a portion of the loading machine.
• the same reference notations will be used for the same details in fig. 2 as in fig. 1.
• the plus side of the double-acting lifting cylinder 1 is articulately fastened on the lifting arm 18 of the loading machine, the lower end of the lifting arm being articulately fastened in an attachment 19 of the machine.
• the piston rod 20 of the lifting cylinder 1 is with its lower end articulately fastened in the attachment 19 on a lower level, compared with the lifting arm.
• the hydraulic oil conduit 10 marked from the plus side of the lifting cylinder to the two accumulators 8, 9 and the hydraulic oil conduit 16 to the third accumulator 15.
• fig. 2 are also the hydraulic oil conduits 3, 4 indicated which go to the not shown control valve.
• the apparatus functions in the following way:
• the loading unit will be pressed downwards, which has the consequence that the piston of the lifting cylinder 1 is forced further into the cylinder and the hydraulic oil positioned in front of the piston on the plus side of the lifting cylinder will via the conduit 10 be pressed into the two accumulators 8, 9 via the throttling means 13, 14. Due to this arrangement the movement of the loading unit will be strongly braked up. If the piston cylinder would have been locked during the driving, which has been the normal case previously, the downwards- directed force of the loading unit would with a full force have been transmitted to the chassis of the loading machine with the troublesome consequences and risks this normally would have led to.
• the accumulator 15, connected with the minus side of the lifting cylinder, has also the favourable effect that when scraping the ground backwards by a machine provided with a loading bucket the pressure of the loading bucket, towards the ground will be very even, which leads to a better result of the work.
• the separate throttling means 13, 14, 17 being integral parts of the apparatus could be eliminated if the conduits going to respective accumulator 8, 9, 15 are dimensioned in that way that they function as throttling means.
• the new invention has a positive effect not only when driving on a bumpy road, but it leads also to a softer and more comfortable driving for all types of loading works with the machine.

Landscapes

• Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Civil Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Operation Control Of Excavators (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=20402127

Family Applications (1)

Country Status (3)

Families Citing this family (4)

Family Cites Families (1)

• 1996
  • 1996-10-21 EP EP96941238A patent/EP0932730A1/de not_active Ceased
  • 1996-10-21 AU AU10436/97A patent/AU1043697A/en not_active Abandoned
  • 1996-10-21 WO PCT/SE1996/001346 patent/WO1998017873A1/en not_active Application Discontinuation

Non-Patent Citations (1)

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