[go: up one dir, main page]

WO2017023669A1 - Valve assembly, hydraulic system and machine comprising the valve assembly - Google Patents

Valve assembly, hydraulic system and machine comprising the valve assembly Download PDF

Info

Publication number
WO2017023669A1
WO2017023669A1 PCT/US2016/044404 US2016044404W WO2017023669A1 WO 2017023669 A1 WO2017023669 A1 WO 2017023669A1 US 2016044404 W US2016044404 W US 2016044404W WO 2017023669 A1 WO2017023669 A1 WO 2017023669A1
Authority
WO
WIPO (PCT)
Prior art keywords
valve
port
working
directional valve
fluid connection
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2016/044404
Other languages
French (fr)
Inventor
Changfa HUANG
Haifeng Wu
Weidong Chen
Jianxin Lu
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Caterpillar Inc
Original Assignee
Caterpillar Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Caterpillar Inc filed Critical Caterpillar Inc
Publication of WO2017023669A1 publication Critical patent/WO2017023669A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

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
    • 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
    • F15B13/06—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with two or more servomotors
    • F15B13/08—Assemblies of units, each for the control of a single servomotor only
    • F15B13/0803—Modular units
    • F15B13/0807—Manifolds
    • F15B13/0814—Monoblock manifolds
    • 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
    • F15B13/06—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with two or more servomotors
    • F15B13/08—Assemblies of units, each for the control of a single servomotor only
    • F15B13/0803—Modular units
    • F15B13/0832—Modular valves
    • F15B13/0842—Monoblock type valves, e.g. with multiple valve spools in a common housing
    • 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
    • E02F9/2264—Arrangements or adaptations of elements for hydraulic drives
    • E02F9/2267—Valves or distributors
    • 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
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30505—Non-return valves, i.e. check 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
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/3056—Assemblies of multiple valves
    • F15B2211/30565—Assemblies of multiple valves having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve
    • F15B2211/3058—Assemblies of multiple valves having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve having additional valves for interconnecting the fluid chambers of a double-acting actuator, e.g. for regeneration mode or for floating mode
    • 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
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50518—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief valves

Definitions

  • the present utility model generally relates to a valve assembly, more particularly to a valve assembly used for a hydraulic system of a machine.
  • the present utility model further relates to a hydraulic system comprising the valve assembly, and a machine comprising the hydraulic system.
  • a machine such as a wheel loader, an excavator, a bulldozer, a grader or other types of heavy equipments generally accomplishes various tasks by using a plurality of actuators (for example hydraulic cylinder) supplied with hydraulic fluid from one or more pumps on the machine.
  • the working device of such machine especially the wheel loader, mainly comprises a boom and a bucket.
  • a hydraulic system of the machine supplies hydraulic fluid to a lifting hydraulic cylinder and a bucket hydraulic cylinder which are associated with the boom and the bucket respectively, so as to realize different actions, such as lifting or descending of the boom, excavating, dumping and unloading of the bucket, and the like.
  • the hydraulic system of the machine usually comprises a directional valve for controlling a lifting action direction of the boom, a directional valve for controlling a moving direction of the bucket, a main relief valve for setting a highest pressure of the hydraulic system, an anti-backflush load check valve for preventing pressure from a working load from damaging the working pump, a lifting float control valve for controlling fluid communication between a rod end chamber and a head end chamber of the lifting hydraulic cylinder, a relief valve for limiting a highest pressure of a head end chamber of the bucket hydraulic cylinder, and a make-up and relief valve for limiting a highest pressure of a rod end chamber of the bucket hydraulic cylinder and replenishing the hydraulic fluid of the rod end chamber during rapid bucket dumping.
  • valve elements are generally assembled in a single valve block. Since these valve elements are disposed in at least three layers in the valve block, the passage design in the valve block is relatively complex, there are more features to be machined, and the valve block occupies a relative large space.
  • the present utility model aims to solve the above problems and/or other problems in the prior art.
  • the present utility model relates to a valve assembly for a hydraulic system of a machine, and the valve assembly comprises:
  • first working port for being in fluid connection with a head end chamber of a bucket hydraulic cylinder of the hydraulic system
  • second working port for being in fluid connection with a rod end chamber of the bucket hydraulic cylinder
  • third working port for being in fluid connection with a head end chamber of a lifting hydraulic cylinder of the hydraulic system
  • fourth working port for being in fluid connection with a rod end chamber of the lifting hydraulic cylinder
  • first directional valve configured to be in fluid connection with the working pump so as to receive hydraulic fluid pumped by the working pump, and selectively guide the received hydraulic fluid to the head end chamber of the bucket hydraulic cylinder via the first working port or to the rod end chamber of the bucket hydraulic cylinder via the second working port;
  • the second directional valve is configured to be in fluid connection with the first directional valve so as to receive the hydraulic fluid from the first directional valve, and selectively guide the received hydraulic fluid to the lifting hydraulic cylinder;
  • make-up and relief valve an input port of which is in fluid connection with the second working port, and an output port of which is in fluid connection with the tank port;
  • a float control valve disposed between the second directional valve and the tank port, characterized in that the first directional valve, the second directional valve, the main relief valve, the first and second load check valves, the first relief valve, the make-up and relief valve and the float control valve are integrated in a valve block, wherein the float control valve, the first relief valve and the make-up and relief valve are disposed in parallel along a horizontal direction in a first horizontal layer of the valve block, and the first directional valve, the second directional valve and the first load check valve are disposed in parallel along the horizontal direction in a second horizontal layer of the valve block.
  • the present utility model relates to a hydraulic system comprising the valve assembly.
  • the present utility model relates to a machine comprising the hydraulic system.
  • FIG. 1 is a schematic view of a housing of a valve assembly according to the present utility model
  • FIG. 3 shows arrangement of fluid passages of a valve assembly in an incarnating manner
  • FIG. 4 shows a hydraulic circuit corresponding to the valve assembly
  • FIG. 5 is a top view of fluid passages in a second horizontal layer of a valve block.
  • FIG. 6 is a bottom view of fluid passages in a first horizontal layer of a valve block.
  • valve assembly 10 of the present utility model is described in detail with reference to the drawings.
  • the valve assembly can be used for a machine in which a boom and a bucket are used as main working devices, such as a wheel loader.
  • the present utility model is not limited to the specific embodiments, and covers other equivalent solutions with its design concept.
  • the valve 10 comprises a housing 100, a plurality of fluid passages are formed in the housing 100 (with reference to Figure 3), the respective valve elements contained in the valve assembly can be inserted from proper ports on the surface of the housing 100 and are assembled together, thus obtaining the valve assembly.
  • Figure 2 schematically shows the assembled valve assembly 10.
  • a top of the housing 100 is provided with a port 110 used for inserting a second load check valve 122, a port 120 used for inserting a main relief valve 1, first and second working ports 150 and 160 used for being in fluid connection with a head end chamber and a rod end chamber of a bucket hydraulic cylinder, and third and fourth working ports 130 and 140 used for being in fluid connection with a head end chamber and a rod end chamber of a lifting hydraulic cylinder.
  • a front side surface (that is, the side surface close to the reader in Figure 1) of the housing 100 is provided with a pump port (oil inlet, P) used for being in fluid connection with a working pump of the hydraulic system and a tank port (oil returning port, T) used for being in fluid connection with a hydraulic oil tank.
  • a right side surface of the housing 100 is provided with a port 200 used for inserting a float control valve 3, a port 210 used for inserting a first relief valve 4, a port 220 used for inserting a make-up and relief valve 5, a port 230 used for inserting a valve core of a first directional valve 7, and a port 240 used for inserting a valve core of a second directional valve 6.
  • a part of the housing adjacent to the pump port P and the tank port T is provided with a convex part, and a port 190 used for inserting a first load check valve 121 is formed at a right side surface of the convex part.
  • a port 190 used for inserting a first load check valve 121 is formed at a right side surface of the convex part.
  • the positions of the pump port P, the tank port T, the port 210 for the first relief valve 4, the port 220 for the make-up and relief valve 5, and the port 120 for the main relief valve 1 on the housing 100 can be appropriately changed as required, and are not limited to the positions as shown in Figure 1.
  • the first directional valve 7 is associated with the bucket hydraulic cylinder for controlling action of a bucket, and the first directional valve is configured to be in fluid connection with the working pump so as to receive hydraulic fluid pumped by the working pump, and selectively guide the received hydraulic fluid to the bucket hydraulic cylinder, for example, guide to the head end chamber of the bucket hydraulic cylinder via the first working port 150 or guide to the rod end chamber of the bucket hydraulic cylinder via the second working port 160.
  • the second directional valve 6 is associated with the lifting hydraulic cylinder for controlling the lifting and descending of a boom, and the second directional valve is configured to be in fluid connection with the first directional valve 7 so as to receive hydraulic fluid from the first directional valve 7, and selectively guide the received hydraulic fluid to the lifting hydraulic cylinder, for example, guide to the head end chamber of the lifting hydraulic cylinder via the third working port 130 or guide to the rod end chamber of the lifting hydraulic cylinder via the fourth working port 140.
  • valve assembly 10 After all valve elements (i.e., the main relief valve 1, the first and second load check valves 121 and 122, the float control valve 3, the first relief valve 4, the make-up and relief valve 5 and valve cores of the first and second directional valves) are inserted into the housing 100 through corresponding ports and are assembled together, the valve assembly 10 according to the present utility model can be obtained, as shown in Figure 2.
  • a hydraulic circuit corresponding to the valve assembly 10 is shown in Figure 4.
  • the hydraulic fluid pumped by the working pump can be selectively guided to the lifting hydraulic cylinder and/or the bucket hydraulic cylinder, so as to realize different actions, such as lifting or descending of the boom, excavating, dumping and unloading of the bucket, and the like.
  • the first directional valve 7 is a three-position six-way valve, comprising a first port 21 in fluid connection with the hydraulic oil tank, a second port 22 in fluid connection with an output end (i.e. pump port P) of the working pump directly, a third port 23 in fluid connection with the output end of the working pump via the second load check valve 122, a fourth port 24 in fluid connection with the rod end chamber of the bucket hydraulic cylinder, a sixth port 26 in fluid connection with the head end chamber of the bucket hydraulic cylinder, and a fifth port 25 in fluid connection with the second directional valve 6.
  • the second load check valve 122 only allows the fluid to flow to the third port 23 from the working pump, and does not allow flowing in the opposite direction, and has a function of preventing a pressure of a working load from impacting and damaging the working pump.
  • the first directional valve 7 has a first working position, a second working position and a third working position, wherein, when the first directional valve is in the first working position (the middle position as shown in Figure 4), the first port 21, the third port 23, the fourth port 24 and the sixth port 26 are cut off, and the second port 22 and the fifth port 25 are in fluid communication.
  • the first directional valve is in the second working position (the left position as shown in Figure 4)
  • the first port 21 and the sixth port 26 are in fluid communication
  • the third port 23 and the fourth port 24 are in fluid communication
  • the second port 22 and the fifth port 25 are cut off.
  • the first directional valve When the first directional valve is in the third working position (the right position as shown in Figure 4), the first port 21 and the fourth port 24 are in fluid communication, the third port 23 and the sixth port 26 are in fluid communication, and the second port 22 and the fifth port 25 are cut off.
  • the hydraulic fluid from the working pump is guided to the second directional valve via the first directional valve; and when the first directional valve is in the second or third working position, the hydraulic fluid from the working pump is guided to one of the first and second working ports via the first directional valve, and the hydraulic fluid at the other one of the first and second working ports is returned back to the hydraulic oil tank via the first directional valve.
  • the second directional valve 6 is also a three-position six-way valve, comprising a first port 31 in fluid connection with the hydraulic oil tank, a second port 32 in fluid connection with the fifth port 25 of the first directional valve 7, a third port 33 in fluid connection with the fifth port 25 of the first directional valve 7 via the first load check valve 121, a fourth port
  • the first load check valve 121 only allows the fluid to flow to the third port 33 of the second directional valve 6 from the fifth port 25 of the first directional valve 7, and does not allow flowing in the opposite direction, thereby can prevent a pressure of a working load from impacting and damaging the working pump.
  • the second directional valve 6 has a first working position, a second working position and a third working position, wherein, when the second directional valve is in the first working position (the middle position as shown in Figure 4), the first port 31, the third port 33, the fourth port 34 and the sixth port 36 are cut off, and the second port 32 and the fifth port 35 are in fluid communication.
  • the second directional valve is in the second working position (the left position as shown in Figure 4)
  • the first port 31 and the sixth port 36 are in fluid communication
  • the third port 33 and the fourth port 34 are in fluid communication
  • the second port 32 and the fifth port 35 are cut off.
  • the second directional valve When the second directional valve is in the third working position (the right position as shown in Figure 4), the first port 31 and the fourth port 34 are in fluid communication, the third port 33 and the sixth port 36 are in fluid communication, and the second port 32 and the fifth port 35 are cut off.
  • the hydraulic fluid from the first directional valve is directly returned back to the hydraulic oil tank via the second directional valve; and when the second directional valve is in the second or third working position, the hydraulic fluid from the first directional valve is guided to one of the third and fourth working ports via the second directional valve, and the hydraulic fluid at the other one of the third and fourth working ports is returned back to the hydraulic oil tank via the second directional valve.
  • an input port of the main relief valve 1 for setting a highest pressure of the hydraulic circuit is in fluid connection with the pump port P, and an output port thereof is in fluid connection with the tank port T.
  • the first relief valve 4 is used for limiting a highest pressure of the head end chamber of the bucket hydraulic cylinder, an input port thereof is in fluid connection with the first working port (leading to the head end chamber of the bucket hydraulic cylinder), and an output port thereof is in fluid connection with the tank port T.
  • the make-up and relief valve 5 is used for limiting a highest pressure of the rod end chamber of the bucket hydraulic cylinder and replenishing hydraulic fluid to the rod end chamber when the bucket is quickly tipped, an input port thereof is in fluid connection with the second working port (leading to the rod end chamber of the bucket hydraulic cylinder), and an output port thereof is in fluid connection with the tank port T.
  • the float control valve 3 is disposed between the second directional valve and the tank port and is used for controlling the communication between the head end chamber and the rod end chamber of the lifting hydraulic cylinder during floating operation of the machine.
  • Figures 3, 5 and 6 the arrangement of the respective valve elements in the housing 100 can be well known.
  • Figures 3, 5 and 6 actually show in a manner that the fluid passages formed within the housing 100 are incarnated.
  • the respective valve elements are integrated in a valve block in two layers, wherein the float control valve 3, the first relief valve 4 and the make-up and relief valve 5 are disposed in parallel along a horizontal direction in a first horizontal layer (the upper layer as shown in Figure 3) of the valve block, and the first directional valve 7, the second directional valve 6 and the first load check valve 121 are disposed in parallel along the same horizontal direction in a second horizontal layer (the lower layer as shown in Figure 3) of the valve block.
  • the main relief valve 1 and the second load check valve 122 are disposed along a direction perpendicular to the first and second horizontal layers, and are at least partially located in the first horizontal layer.
  • the first working port 150, the second working port 160, the third working port 130 and the fourth working port 140 are arranged at the top of the valve block in a vertical orientation perpendicular to the first and second horizontal layers.
  • the tank port T is disposed in a side surface of the valve block in a horizontal orientation parallel to the first and second horizontal layers, and is located in the first horizontal layer.
  • the pump port P is disposed in a side surface of the valve block in a horizontal orientation parallel to the first and second horizontal layers, and is located in the second horizontal layer.
  • Figures 5 and 6 show the first and second horizontal layers in a sectional view respectively.
  • a fluid passage 450 leads to the first working port 150
  • a fluid passage 460 leads to the second working port 160
  • a fluid passage 470 leads to the third working port 130
  • a fluid passage 440 leads to the fourth working port 140.
  • a fluid passage 490 is communicated with the hydraulic oil tank.
  • a fluid passage 480 is used for receiving the second load check valve 122.
  • a fluid passage 410 is used for receiving the main relief valve 1.
  • the respective valve elements are arranged in two horizontal layers, compared with the valve block (wherein the respective valve elements are disposed in at least three layers) in the prior art, such arrangement is advantageous in that the valve block structure is more compact, the integration among the valve elements is optimized, the features to be machined in the housing of the valve block are reduced, manufacturing cost of the valve block is significantly reduced, and occupying space of the valve block is decreased.
  • a hydraulic system incorporated with the valve assembly of the present utility model is particularly suitable for a loader. It is understood that the valve assembly can be used for other machines in appropriate circumstances.
  • valve assembly of the present utility model is described by means of the specific embodiments. It is obvious for those skilled in the art that various changes and variants can be made to the valve assembly of the present utility model without departing from the spirit of the present utility model.
  • the description and examples are only exemplary, and the true scope is defined by the annexed claims and their equivalent solutions.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)

Abstract

The present utility model relates to a valve assembly comprising a first directional valve configured to be in fluid connection with a working pump so as to receive hydraulic fluid pumped by the working pump, and selectively guide the received hydraulic fluid to a bucket hydraulic cylinder; a second directional valve configured to be in fluid connection with the first directional valve so as to receive hydraulic fluid from the first directional valve, and selectively guide the received hydraulic fluid to a lifting hydraulic cylinder; a main relief valve; a first load check valve; a second load check valve; a first relief valve; a make-up and relief valve; and a float control valve, and characterized in that the respective valve elements are integrated in a valve block, wherein the float control valve, the first relief valve and the make-up and relief valve are disposed in parallel along a horizontal direction in a first horizontal layer of the valve block, and the first directional valve, the second directional valve and the first load check valve are disposed in parallel along the horizontal direction in a second horizontal layer of the valve block. The present utility model further relates to a hydraulic system and a machine comprising the valve assembly.

Description

VALVE ASSEMBLY, HYDRAULIC SYSTEM AND MACHINE COMPRISING THE
VALVE ASSEMBLY
TECHNICAL FIELD
The present utility model generally relates to a valve assembly, more particularly to a valve assembly used for a hydraulic system of a machine. The present utility model further relates to a hydraulic system comprising the valve assembly, and a machine comprising the hydraulic system.
BACKGROUND OF THE UTILITY MODEL
A machine such as a wheel loader, an excavator, a bulldozer, a grader or other types of heavy equipments generally accomplishes various tasks by using a plurality of actuators (for example hydraulic cylinder) supplied with hydraulic fluid from one or more pumps on the machine. The working device of such machine, especially the wheel loader, mainly comprises a boom and a bucket. A hydraulic system of the machine supplies hydraulic fluid to a lifting hydraulic cylinder and a bucket hydraulic cylinder which are associated with the boom and the bucket respectively, so as to realize different actions, such as lifting or descending of the boom, excavating, dumping and unloading of the bucket, and the like.
In order to realize the above mentioned various actions, the hydraulic system of the machine usually comprises a directional valve for controlling a lifting action direction of the boom, a directional valve for controlling a moving direction of the bucket, a main relief valve for setting a highest pressure of the hydraulic system, an anti-backflush load check valve for preventing pressure from a working load from damaging the working pump, a lifting float control valve for controlling fluid communication between a rod end chamber and a head end chamber of the lifting hydraulic cylinder, a relief valve for limiting a highest pressure of a head end chamber of the bucket hydraulic cylinder, and a make-up and relief valve for limiting a highest pressure of a rod end chamber of the bucket hydraulic cylinder and replenishing the hydraulic fluid of the rod end chamber during rapid bucket dumping. In the existing machine, these valve elements are generally assembled in a single valve block. Since these valve elements are disposed in at least three layers in the valve block, the passage design in the valve block is relatively complex, there are more features to be machined, and the valve block occupies a relative large space.
The present utility model aims to solve the above problems and/or other problems in the prior art.
SUMMARY OF THE UTILITY MODEL
In one aspect, the present utility model relates to a valve assembly for a hydraulic system of a machine, and the valve assembly comprises:
- a pump port P for being in fluid connection with a working pump;
- a tank port T for being in fluid connection with a hydraulic oil tank;
- a first working port for being in fluid connection with a head end chamber of a bucket hydraulic cylinder of the hydraulic system, a second working port for being in fluid connection with a rod end chamber of the bucket hydraulic cylinder, a third working port for being in fluid connection with a head end chamber of a lifting hydraulic cylinder of the hydraulic system, and a fourth working port for being in fluid connection with a rod end chamber of the lifting hydraulic cylinder;
- a first directional valve, wherein the first directional valve is configured to be in fluid connection with the working pump so as to receive hydraulic fluid pumped by the working pump, and selectively guide the received hydraulic fluid to the head end chamber of the bucket hydraulic cylinder via the first working port or to the rod end chamber of the bucket hydraulic cylinder via the second working port;
- a second directional valve, wherein the second directional valve is configured to be in fluid connection with the first directional valve so as to receive the hydraulic fluid from the first directional valve, and selectively guide the received hydraulic fluid to the lifting hydraulic cylinder;
- a main relief valve, an input port of which is in fluid connection with the pump port, and an output port of which is in fluid connection with the tank port;
- a first load check valve, an input port of which is in fluid connection with the pump port, and an output port of which is in fluid connection with the first directional valve;
- a second load check valve, an input port of which is in fluid connection with the first directional valve, and an output port of which is in fluid connection with the second directional valve;
- a first relief valve, an input port of which is in fluid connection with the first working port, and an output port of which is in fluid connection with the tank port;
- a make-up and relief valve, an input port of which is in fluid connection with the second working port, and an output port of which is in fluid connection with the tank port; and
- a float control valve disposed between the second directional valve and the tank port, characterized in that the first directional valve, the second directional valve, the main relief valve, the first and second load check valves, the first relief valve, the make-up and relief valve and the float control valve are integrated in a valve block, wherein the float control valve, the first relief valve and the make-up and relief valve are disposed in parallel along a horizontal direction in a first horizontal layer of the valve block, and the first directional valve, the second directional valve and the first load check valve are disposed in parallel along the horizontal direction in a second horizontal layer of the valve block.
In another aspect, the present utility model relates to a hydraulic system comprising the valve assembly.
In still another aspect, the present utility model relates to a machine comprising the hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS
The present utility model is described in greater detail by referring to schematic drawings. The drawings and corresponding embodiments are merely intended to explain rather than limit the present utility model. In the drawings:
- Figure 1 is a schematic view of a housing of a valve assembly according to the present utility model;
- Figure 2 schematically shows an assembled valve assembly;
- Figure 3 shows arrangement of fluid passages of a valve assembly in an incarnating manner;
- Figure 4 shows a hydraulic circuit corresponding to the valve assembly;
- Figure 5 is a top view of fluid passages in a second horizontal layer of a valve block; and
- Figure 6 is a bottom view of fluid passages in a first horizontal layer of a valve block.
DETAILED DESCRIPTION OF THE EMBODFMENTS
A valve assembly 10 of the present utility model is described in detail with reference to the drawings. In preferable embodiments as shown in the drawings, the valve assembly can be used for a machine in which a boom and a bucket are used as main working devices, such as a wheel loader. But it should be understood that the present utility model is not limited to the specific embodiments, and covers other equivalent solutions with its design concept.
As shown in Figure 1, the valve 10 comprises a housing 100, a plurality of fluid passages are formed in the housing 100 (with reference to Figure 3), the respective valve elements contained in the valve assembly can be inserted from proper ports on the surface of the housing 100 and are assembled together, thus obtaining the valve assembly. Figure 2 schematically shows the assembled valve assembly 10.
As shown in Figure 1, and with reference to Figure 2 and Figure 4, a top of the housing 100 is provided with a port 110 used for inserting a second load check valve 122, a port 120 used for inserting a main relief valve 1, first and second working ports 150 and 160 used for being in fluid connection with a head end chamber and a rod end chamber of a bucket hydraulic cylinder, and third and fourth working ports 130 and 140 used for being in fluid connection with a head end chamber and a rod end chamber of a lifting hydraulic cylinder. A front side surface (that is, the side surface close to the reader in Figure 1) of the housing 100 is provided with a pump port (oil inlet, P) used for being in fluid connection with a working pump of the hydraulic system and a tank port (oil returning port, T) used for being in fluid connection with a hydraulic oil tank. A right side surface of the housing 100 is provided with a port 200 used for inserting a float control valve 3, a port 210 used for inserting a first relief valve 4, a port 220 used for inserting a make-up and relief valve 5, a port 230 used for inserting a valve core of a first directional valve 7, and a port 240 used for inserting a valve core of a second directional valve 6. In addition, a part of the housing adjacent to the pump port P and the tank port T is provided with a convex part, and a port 190 used for inserting a first load check valve 121 is formed at a right side surface of the convex part. It should be noted that the direction terms such as "top", "front side surface", "right side surface" and "horizontal direction" are defined relative to the placement of the valve assembly (or the housing thereof) in Figure 1, and are merely intended for the purpose of clear description.
It can be understood that the positions of the pump port P, the tank port T, the port 210 for the first relief valve 4, the port 220 for the make-up and relief valve 5, and the port 120 for the main relief valve 1 on the housing 100 can be appropriately changed as required, and are not limited to the positions as shown in Figure 1.
In the present embodiment, the first directional valve 7 is associated with the bucket hydraulic cylinder for controlling action of a bucket, and the first directional valve is configured to be in fluid connection with the working pump so as to receive hydraulic fluid pumped by the working pump, and selectively guide the received hydraulic fluid to the bucket hydraulic cylinder, for example, guide to the head end chamber of the bucket hydraulic cylinder via the first working port 150 or guide to the rod end chamber of the bucket hydraulic cylinder via the second working port 160. The second directional valve 6 is associated with the lifting hydraulic cylinder for controlling the lifting and descending of a boom, and the second directional valve is configured to be in fluid connection with the first directional valve 7 so as to receive hydraulic fluid from the first directional valve 7, and selectively guide the received hydraulic fluid to the lifting hydraulic cylinder, for example, guide to the head end chamber of the lifting hydraulic cylinder via the third working port 130 or guide to the rod end chamber of the lifting hydraulic cylinder via the fourth working port 140.
After all valve elements (i.e., the main relief valve 1, the first and second load check valves 121 and 122, the float control valve 3, the first relief valve 4, the make-up and relief valve 5 and valve cores of the first and second directional valves) are inserted into the housing 100 through corresponding ports and are assembled together, the valve assembly 10 according to the present utility model can be obtained, as shown in Figure 2.
A hydraulic circuit corresponding to the valve assembly 10 is shown in Figure 4. By the hydraulic circuit, the hydraulic fluid pumped by the working pump can be selectively guided to the lifting hydraulic cylinder and/or the bucket hydraulic cylinder, so as to realize different actions, such as lifting or descending of the boom, excavating, dumping and unloading of the bucket, and the like.
As shown in Figure 4, the first directional valve 7 is a three-position six-way valve, comprising a first port 21 in fluid connection with the hydraulic oil tank, a second port 22 in fluid connection with an output end (i.e. pump port P) of the working pump directly, a third port 23 in fluid connection with the output end of the working pump via the second load check valve 122, a fourth port 24 in fluid connection with the rod end chamber of the bucket hydraulic cylinder, a sixth port 26 in fluid connection with the head end chamber of the bucket hydraulic cylinder, and a fifth port 25 in fluid connection with the second directional valve 6. The second load check valve 122 only allows the fluid to flow to the third port 23 from the working pump, and does not allow flowing in the opposite direction, and has a function of preventing a pressure of a working load from impacting and damaging the working pump.
The first directional valve 7 has a first working position, a second working position and a third working position, wherein, when the first directional valve is in the first working position (the middle position as shown in Figure 4), the first port 21, the third port 23, the fourth port 24 and the sixth port 26 are cut off, and the second port 22 and the fifth port 25 are in fluid communication. When the first directional valve is in the second working position (the left position as shown in Figure 4), the first port 21 and the sixth port 26 are in fluid communication, the third port 23 and the fourth port 24 are in fluid communication, and the second port 22 and the fifth port 25 are cut off. When the first directional valve is in the third working position (the right position as shown in Figure 4), the first port 21 and the fourth port 24 are in fluid communication, the third port 23 and the sixth port 26 are in fluid communication, and the second port 22 and the fifth port 25 are cut off.
Therefore, when the first directional valve is in the first working position, the hydraulic fluid from the working pump is guided to the second directional valve via the first directional valve; and when the first directional valve is in the second or third working position, the hydraulic fluid from the working pump is guided to one of the first and second working ports via the first directional valve, and the hydraulic fluid at the other one of the first and second working ports is returned back to the hydraulic oil tank via the first directional valve.
The second directional valve 6 is also a three-position six-way valve, comprising a first port 31 in fluid connection with the hydraulic oil tank, a second port 32 in fluid connection with the fifth port 25 of the first directional valve 7, a third port 33 in fluid connection with the fifth port 25 of the first directional valve 7 via the first load check valve 121, a fourth port
34 in fluid connection with the head end chamber of the lifting hydraulic cylinder, a fifth port
35 in fluid connection with the hydraulic oil tank, and a sixth port 36 in fluid connection with the rod end chamber of the lifting hydraulic cylinder. The first load check valve 121 only allows the fluid to flow to the third port 33 of the second directional valve 6 from the fifth port 25 of the first directional valve 7, and does not allow flowing in the opposite direction, thereby can prevent a pressure of a working load from impacting and damaging the working pump.
The second directional valve 6 has a first working position, a second working position and a third working position, wherein, when the second directional valve is in the first working position (the middle position as shown in Figure 4), the first port 31, the third port 33, the fourth port 34 and the sixth port 36 are cut off, and the second port 32 and the fifth port 35 are in fluid communication. When the second directional valve is in the second working position (the left position as shown in Figure 4), the first port 31 and the sixth port 36 are in fluid communication, the third port 33 and the fourth port 34 are in fluid communication, and the second port 32 and the fifth port 35 are cut off. When the second directional valve is in the third working position (the right position as shown in Figure 4), the first port 31 and the fourth port 34 are in fluid communication, the third port 33 and the sixth port 36 are in fluid communication, and the second port 32 and the fifth port 35 are cut off.
Therefore, when the second directional valve is in the first working position, the hydraulic fluid from the first directional valve is directly returned back to the hydraulic oil tank via the second directional valve; and when the second directional valve is in the second or third working position, the hydraulic fluid from the first directional valve is guided to one of the third and fourth working ports via the second directional valve, and the hydraulic fluid at the other one of the third and fourth working ports is returned back to the hydraulic oil tank via the second directional valve.
In addition, as shown in Figure 4, an input port of the main relief valve 1 for setting a highest pressure of the hydraulic circuit is in fluid connection with the pump port P, and an output port thereof is in fluid connection with the tank port T. The first relief valve 4 is used for limiting a highest pressure of the head end chamber of the bucket hydraulic cylinder, an input port thereof is in fluid connection with the first working port (leading to the head end chamber of the bucket hydraulic cylinder), and an output port thereof is in fluid connection with the tank port T. The make-up and relief valve 5 is used for limiting a highest pressure of the rod end chamber of the bucket hydraulic cylinder and replenishing hydraulic fluid to the rod end chamber when the bucket is quickly tipped, an input port thereof is in fluid connection with the second working port (leading to the rod end chamber of the bucket hydraulic cylinder), and an output port thereof is in fluid connection with the tank port T. The float control valve 3 is disposed between the second directional valve and the tank port and is used for controlling the communication between the head end chamber and the rod end chamber of the lifting hydraulic cylinder during floating operation of the machine.
By means of the Figures 3, 5 and 6, the arrangement of the respective valve elements in the housing 100 can be well known. For the purpose of clarity and convenient understanding, Figures 3, 5 and 6 actually show in a manner that the fluid passages formed within the housing 100 are incarnated. As shown in the Figures, the respective valve elements are integrated in a valve block in two layers, wherein the float control valve 3, the first relief valve 4 and the make-up and relief valve 5 are disposed in parallel along a horizontal direction in a first horizontal layer (the upper layer as shown in Figure 3) of the valve block, and the first directional valve 7, the second directional valve 6 and the first load check valve 121 are disposed in parallel along the same horizontal direction in a second horizontal layer (the lower layer as shown in Figure 3) of the valve block.
In addition, the main relief valve 1 and the second load check valve 122 are disposed along a direction perpendicular to the first and second horizontal layers, and are at least partially located in the first horizontal layer. Referring to Figures 1 and 3, the first working port 150, the second working port 160, the third working port 130 and the fourth working port 140 are arranged at the top of the valve block in a vertical orientation perpendicular to the first and second horizontal layers. The tank port T is disposed in a side surface of the valve block in a horizontal orientation parallel to the first and second horizontal layers, and is located in the first horizontal layer. The pump port P is disposed in a side surface of the valve block in a horizontal orientation parallel to the first and second horizontal layers, and is located in the second horizontal layer.
Figures 5 and 6 show the first and second horizontal layers in a sectional view respectively. As shown in the Figures, a fluid passage 450 leads to the first working port 150, a fluid passage 460 leads to the second working port 160, a fluid passage 470 leads to the third working port 130, and a fluid passage 440 leads to the fourth working port 140. A fluid passage 490 is communicated with the hydraulic oil tank. A fluid passage 480 is used for receiving the second load check valve 122. A fluid passage 410 is used for receiving the main relief valve 1.
In the valve assembly according to the present utility mode, the respective valve elements are arranged in two horizontal layers, compared with the valve block (wherein the respective valve elements are disposed in at least three layers) in the prior art, such arrangement is advantageous in that the valve block structure is more compact, the integration among the valve elements is optimized, the features to be machined in the housing of the valve block are reduced, manufacturing cost of the valve block is significantly reduced, and occupying space of the valve block is decreased.
A hydraulic system incorporated with the valve assembly of the present utility model is particularly suitable for a loader. It is understood that the valve assembly can be used for other machines in appropriate circumstances.
The valve assembly of the present utility model is described by means of the specific embodiments. It is obvious for those skilled in the art that various changes and variants can be made to the valve assembly of the present utility model without departing from the spirit of the present utility model. The description and examples are only exemplary, and the true scope is defined by the annexed claims and their equivalent solutions.

Claims

1. A valve assembly for a hydraulic system of a machine, comprising:
- a pump port (P) for being in fluid connection with a working pump;
- a tank port (T) for being in fluid connection with a hydraulic oil tank;
- a first working port for being in fluid connection with a head end chamber of a bucket hydraulic cylinder of the hydraulic system, a second working port for being in fluid connection with a rod end chamber of the bucket hydraulic cylinder, a third working port for being in fluid connection with a head end chamber of a lifting hydraulic cylinder of the hydraulic system, and a fourth working port for being in fluid connection with a rod end chamber of the lifting hydraulic cylinder;
- a first directional valve (7), wherein the first directional valve is configured to be in fluid connection with the working pump so as to receive hydraulic fluid pumped by the working pump, and selectively guide the received hydraulic fluid to the head end chamber of the bucket hydraulic cylinder via the first working port or to the rod end chamber of the bucket hydraulic cylinder via the second working port;
- a second directional valve (6), wherein the second directional valve is configured to be in fluid connection with the first directional valve so as to receive the hydraulic fluid from the first directional valve, and selectively guide the received hydraulic fluid to the lifting hydraulic cylinder;
- a main relief valve (1), an input port of which is in fluid connection with the pump port, and an output port of which is in fluid connection with the tank port;
- a first load check valve (121), an input port of which is in fluid connection with the pump port, and an output port of which is in fluid connection with the first directional valve;
- a second load check valve (122), an input port of which is in fluid connection with the first directional valve, and an output port of which is in fluid connection with the second directional valve;
- a first relief valve (4), an input port of which is in fluid connection with the first working port, and an output port of which is in fluid connection with the tank port; - a make-up and relief valve (5), an input port of which is in fluid connection with the second working port, and an output port of which is in fluid connection with the tank port; and
- a float control valve (3) disposed between the second directional valve and the tank port,
characterized in that the first directional valve (7), the second directional valve (6), the main relief valve (1), the first and second load check valves (121, 122), the first relief valve (4), the make-up and relief valve (5) and the float control valve (3) are integrated in a valve block, wherein the float control valve (3), the first relief valve (4) and the make-up and relief valve (5) are disposed in parallel along a horizontal direction in a first horizontal layer of the valve block, and the first directional valve (7), the second directional valve (6) and the first load check valve (121) are disposed in parallel along the horizontal direction in a second horizontal layer of the valve block.
2. The valve assembly according to claim 1, characterized in that, the main relief valve (1) and the second load check valve (122) are disposed along a direction perpendicular to the first and second horizontal layers, and are at least partially located in the first horizontal layer.
3. The valve assembly according to claim 1 or 2, characterized in that, the first, second, third and fourth working ports are disposed at the top of the valve block in a vertical orientation perpendicular to the first and second horizontal layers.
4. The valve assembly according to claim 1 or 2, characterized in that, the tank port is disposed in a side surface of the valve block in a horizontal orientation parallel to the first and second horizontal layers, and is located in the first horizontal layer.
5. The valve assembly according to claim 1 or 2, characterized in that, the pump port is disposed in a side surface of the valve block in a horizontal orientation parallel to the first and second horizontal layers, and is located in the second horizontal layer.
6. The valve assembly according to claim 1 or 2, characterized in that, the first directional valve (7) has a first working position, a second working position and a third working position, wherein, when the first directional valve is in the first working position, hydraulic fluid from the working pump is guided to the second directional valve via the first directional valve; and when the first directional valve is in the second or third working position, the hydraulic fluid from the working pump is guided to one of the first and second working ports via the first directional valve, and the hydraulic fluid at the other one of the first and second working ports is returned back to the hydraulic oil tank via the first directional valve.
7. The valve assembly according to claim 1 or 2, characterized in that, the second directional valve (6) has a first working position, a second working position and a third working position, wherein, when the second directional valve is in the first working position, hydraulic fluid from the first directional valve is directly returned back to the hydraulic oil tank via the second directional valve; and when the second directional valve is in the second or third working position, the hydraulic fluid from the first directional valve is guided to one of the third and fourth working ports via the second directional valve, and the hydraulic fluid at the other one of the third and fourth working ports is returned back to the hydraulic oil tank via the second directional valve.
8. A hydraulic system for a machine, comprising the valve assembly according to any one of claims 1 to 7.
9. A machine comprising the hydraulic system according to claim 8.
10. The machine according to claim 9, characterized in that, the machine is a loader.
PCT/US2016/044404 2015-08-03 2016-07-28 Valve assembly, hydraulic system and machine comprising the valve assembly Ceased WO2017023669A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201520574993.3 2015-08-03
CN201520574993.3U CN204828113U (en) 2015-08-03 2015-08-03 Valve module, including hydraulic system and machine of this valve module

Publications (1)

Publication Number Publication Date
WO2017023669A1 true WO2017023669A1 (en) 2017-02-09

Family

ID=54685720

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2016/044404 Ceased WO2017023669A1 (en) 2015-08-03 2016-07-28 Valve assembly, hydraulic system and machine comprising the valve assembly

Country Status (2)

Country Link
CN (1) CN204828113U (en)
WO (1) WO2017023669A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114658710A (en) * 2022-02-28 2022-06-24 浙江海宏液压科技股份有限公司 Working valve block and forklift

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10858806B2 (en) * 2019-03-12 2020-12-08 Caterpillar Inc. Modular manifold having at least two control modules for controlling operation of at least two hydraulic actuators of an earthmoving machine

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2982101A (en) * 1957-12-05 1961-05-02 Eimco Corp Pressure fluid control system
EP1434943B1 (en) * 2001-10-08 2006-03-22 Husco International, Inc. Multiple hydraulic valve assembly with a monolithic block
US20110132473A1 (en) * 2009-12-04 2011-06-09 Walvoil Fluid Power Corp. Hydraulic control valve assembly with monolithic body and single spool port lock
CN104776075A (en) * 2014-01-14 2015-07-15 卡特彼勒（青州）有限公司 Hydraulic valve and loader including same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2982101A (en) * 1957-12-05 1961-05-02 Eimco Corp Pressure fluid control system
EP1434943B1 (en) * 2001-10-08 2006-03-22 Husco International, Inc. Multiple hydraulic valve assembly with a monolithic block
US20110132473A1 (en) * 2009-12-04 2011-06-09 Walvoil Fluid Power Corp. Hydraulic control valve assembly with monolithic body and single spool port lock
CN104776075A (en) * 2014-01-14 2015-07-15 卡特彼勒（青州）有限公司 Hydraulic valve and loader including same

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114658710A (en) * 2022-02-28 2022-06-24 浙江海宏液压科技股份有限公司 Working valve block and forklift

Also Published As

Publication number Publication date
CN204828113U (en) 2015-12-02

Similar Documents

Publication Publication Date Title
JP5427370B2 (en) Multiple direction switching valve with bucket translation function
US9080310B2 (en) Closed-loop hydraulic system having regeneration configuration
US9303632B2 (en) Energy recovery control circuit and work machine
US9261114B2 (en) Hydraulic pressure-regulating valve for construction equipment
US20090025380A1 (en) Fixed/variable hybrid system
US10161110B2 (en) Control valve device
JP3929411B2 (en) Multiple hydraulic spool valve assembly with monolithic body
CN109487838B (en) hydraulic circuit
JP6514522B2 (en) Hydraulic drive system of unloading valve and hydraulic shovel
CN101949373A (en) Pump for forming closed loop
WO2017023669A1 (en) Valve assembly, hydraulic system and machine comprising the valve assembly
US20160002888A1 (en) Variable load sense open center hybrid system
JP5283862B2 (en) Hydraulic control device
US3324881A (en) Dual pressure relief valve system
JPH0755031A (en) Directional control valve for flow rate support
KR102500484B1 (en) directional seated valve
US8806862B2 (en) Smart flow sharing system
JP2007016483A (en) Hydraulic control device for loader
JP4763366B2 (en) Hydraulic control device for loader
CN212225655U (en) Hydraulic flow control valve, hydraulic control system and engineering machinery
US10125797B2 (en) Vent for load sense valves
CN223202398U (en) A loading control valve for an excavator loader
GB2389876A (en) Hydraulic valve arrangement
JP6220131B2 (en) Hydraulic control system and construction machinery equipped with the hydraulic control system
KR101281251B1 (en) Pump control system for excavator

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16747995

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 16747995

Country of ref document: EP

Kind code of ref document: A1