Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
  • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
  • F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
  • F15B11/162—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for giving priority to particular servomotors or users
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
  • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
  • F15B13/022—Flow-dividers; Priority valves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
  • F15B2211/205—Systems with pumps
  • F15B2211/2053—Type of pump
  • F15B2211/20546—Type of pump variable capacity
  • F15B2211/20553—Type of pump variable capacity with pilot circuit, e.g. for controlling a swash plate
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/30—Directional control
  • F15B2211/31—Directional control characterised by the positions of the valve element
  • F15B2211/3105—Neutral or centre positions
  • F15B2211/3116—Neutral or centre positions the pump port being open in the centre position, e.g. so-called open centre
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/40—Flow control
  • F15B2211/405—Flow control characterised by the type of flow control means or valve
  • F15B2211/40515—Flow control characterised by the type of flow control means or valve with variable throttles or orifices
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/40—Flow control
  • F15B2211/42—Flow control characterised by the type of actuation
  • F15B2211/428—Flow control characterised by the type of actuation actuated by fluid pressure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/40—Flow control
  • F15B2211/45—Control of bleed-off flow, e.g. control of bypass flow to the return line
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/60—Circuit components or control therefor
  • F15B2211/605—Load sensing circuits
  • F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
  • F15B2211/6054—Load sensing circuits having valve means between output member and the load sensing circuit using shuttle valves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
  • F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders
  • F15B2211/7142—Multiple output members, e.g. multiple hydraulic motors or cylinders the output members being arranged in multiple groups
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
  • F15B2211/78—Control of multiple output members
  • F15B2211/781—Control of multiple output members one or more output members having priority

Definitions

• the present invention concerns a hydraulic valve with integrated priority valve, especially a support leg valve on a truck-mounted timber crane, according to the preamble to claim 1.
• loading is prepared by lowering a pair of support legs located on one side of the cargo space to the ground which can be extended or contracted telescopically in order to obtain a horizontal position of the cargo space.
• the support legs are used to stabilise the part of the chassis that contains the cargo space, e.g. a truck or its trailer. Without stabilisation, the chassis part may lean in the direction of the load in the crane and impair control of the loading process resulting in a longer working time.
• the valve that controls the movement of the support leg is used for a brief period before operating the crane.
• the support leg valve is often coupled in series with the cock and comprises one open centre valve and is first in the series. This means the flow of hydraulic oil to the crane's functions flows first through the support leg valve, which is consequently always pressurised.
• the support leg valve can also be connected in parallel with the cock via a separate priority valve.
• the support leg valve is a valve with closed centre arranged with an outer pilot line through which a pilot pressure flows to the priority valve regulating the flow.
• Another variant is to connect the support leg valve in parallel with a cock via an external pilot line with a load sensing pressure.
• the pilot line is arranged with a nonreturn valve to lead the load sensing pressure from the support leg valve to a shunt valve arranged in the cock.
• the support leg valve is a valve with closed centre. Both of these couplings involve a relatively costly arrangement and require relatively complicated hose arrangements in relation to the intended purpose.
• a further method of solving problems that arise in conjunction with support leg functions is to use a pump with variable displacement and parallel couple the valves via a switch valve regulated by the driver.
• the support leg valve is then often a load sensing valve with closed centre.
• One disadvantage is that the valve controlling the support leg is constantly under pressure when operating the crane, which may give unwanted movements of the support leg due to the natural leakage inside the slide valves.
• This problem can be solved by fitting a separate priority valve in the system with an output port to the support leg valve and a port to the cock.
• the priority valve is controlled by a signal from the support leg valve, which is often achieved through a pilot line giving a pilot flow from the support leg valve to the priority valve.
• One object of the present invention is to achieve a valve for operating principally the support legs of a timber crane mounted on a truck and also the control of, for example, moving the driver's cab or log carriages in a simple and cheap way without complicated hose arrangements or additional valves.
• Another object is to be able to use the arrangement together with a hydraulic pump with either variable or fixed displacement.
• the support leg valve comprising a one-piece unit with integrated priority valve and control valves with closed centres, the control valves regulating the flow via a signal pressure through a passage in the housing to the priority valve.
• a valve according to the invention comprises a one-piece valve housing 1 with an inlet port 2 connected to a hydraulic pump (P) with fixed or variable displacement, an outlet port 3 connected to a hydraulic tank (T), an outlet port 4 connected to the valve 5:1 controlling the functions of a consumer, such as a crane, and, in this embodiment, outlets to four consumers 5:2a - 5:2d with four identical control valves 6 a-d for controlling support legs, carriages and similar functions.
• the valve can be adapted to the demands placed on its functions in addition to, for example, support legs and carriages, through several control valves being able to be coupled together with the valve housing 1.
• the inlet port 2 is coupled to a priority valve 7 integrated in the valve housing 1 in which a spring-loaded slide 8, called the priority slide, is located.
• a first chamber 9 for building up hydraulic pressure from the inlet port 2.
• a second chamber 10 To the other end of the slide is arranged a second chamber 10.
• the second chamber 10 is connected to load sensing pressure via a passage 11 from the control valve slides 6 a-d.
• a spring 12 a coil spring for instance, with one end resting against the inside of the chamber 12 and the other end against the valve housing. Through the force of the spring 12, the slide 8 is pressed towards the first chamber 9, i.e. in the direction of arrow A, to a first end position.
• the inlet port 2 is in connection via the priority valve 7 with the control valves 6 a-d via a passage 13 with a first restriction 14.
• the load sensing pressure passage 11 is arranged with a connection to the tank T via a passage 15 with a second restriction 16.
• the slides in the control valves 6 a-d arranged with a first flow groove 17 of increasing size to successively open the flow path to one of the consumers 5-2a - 5:2d, for instance a support leg.
• the slides of the control valves 6 a-d are also equipped with a second flow groove 18, which is in connection with the second chamber 10 in the priority valve 7.
• control valve 6a-6d When a control valve 6a-6d is operated, i.e. the valve controlling the functions of consumer 5:2a-5:2d, for instance the support leg, a valve will be activated, i.e. control valve slide 6a will be displaced in the direction of the arrow A in figure 1.
• the flow groove 17 arranged in the slide will open successively, whereby the flow of hydraulic oil to the support leg will gradually increase.
• the second flow groove 18 will open successively to gradually increase the flow to the passage 11 for the load sensing pressure. This will mean the pressure in the second chamber 10 will rise, whereby the priority slide 8 will be displaced to centre position where the pressure in passage 13 corresponds to the total pressure of the spring 12 and the pressure in the second chamber 10.
• a drain 19 has been arranged to the tank T at the second restriction 16. The drain 19 delivers a certain flow from the second flow groove 18 in the control valve slide 6a-6d to the tank T and thereby the desired drop in pressure before it reaches the second chamber 10.
• the control valves slides 6a-6d are designed so that the drain 19 will close at the second restriction 16 for large valve actuations, whereby the first restriction 14 has the greatest effect as the main flow passes through the passage 13.
• the size of this first restriction 14 can be adapted to provide a limited maximum flow for large valve actuations. This can be used to provide a smooth control of the consumers 5:2a -5:2d without any sudden movements.
• the priority slide 8 regulates the drop in pressure across the restriction 14 to a constant value, whereby this maximum flow becomes independent from the load, i.e. the support leg in this example will maintain a constant speed irrespective of the load.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Fluid-Pressure Circuits (AREA)
• Multiple-Way Valves (AREA)
• Check Valves (AREA)
• Pens And Brushes (AREA)
• Forging (AREA)
• Servomotors (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=27607343

Family Applications (1)

Country Status (5)

Citations (2)

Family Cites Families (5)

• 2003
  • 2003-06-19 SE SE0301777A patent/SE525355C2/sv not_active IP Right Cessation
• 2004
  • 2004-06-16 AT AT04749000T patent/ATE548569T1/de active
  • 2004-06-16 EP EP04749000A patent/EP1633987B1/en not_active Expired - Lifetime
  • 2004-06-16 CN CNB2004800170115A patent/CN100480517C/zh not_active Expired - Fee Related
  • 2004-06-16 WO PCT/SE2004/000951 patent/WO2004111467A1/en active Application Filing

Patent Citations (2)

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