CN209743271U

CN209743271U - Loader full-variable hydraulic system and loader

Info

Publication number: CN209743271U
Application number: CN201920509212.0U
Authority: CN
Inventors: 吴国梁; 吴广; 徐海涛
Original assignee: Deere and Co
Current assignee: Deere and Co
Priority date: 2019-04-15
Filing date: 2019-04-15
Publication date: 2019-12-06
Anticipated expiration: 2029-04-15

Abstract

the application discloses loader complete variable hydraulic system and loader, wherein, a loader complete variable hydraulic system includes: a variable displacement pump connected with a load sensitive valve; the shunt valve block is connected with the output port of the variable pump; the steering module is connected with the shunt valve block; the variable pump drives the steering module through oil output by the shunt valve block; the pilot module is connected with the flow dividing valve block; the pilot module comprises a pressure reducing valve group and a pilot valve; the pressure reducing valve group is connected with the pilot valve and the load sensitive valve; the loading module is connected with the shunt valve block; the loading module is connected with the pilot valve; the variable pump drives the loading module through oil output by the shunt valve block; the brake module is connected with the shunt valve block; the variable pump drives the brake module through oil output by the shunt valve block. The loader all-variable hydraulic system and the loader can reduce the fuel consumption rate.

Description

Loader full-variable hydraulic system and loader

Technical Field

the application relates to the field of engineering machinery, in particular to a loader full-variable hydraulic system and a loader.

Background

The loader is a kind of earth and stone shoveling engineering machinery widely used in highway, railway, building, water and electricity, port, mine and other construction projects, and is mainly used for shoveling and loading bulk materials such as soil, gravel, coal and the like and also for light shoveling and digging operation of ore, hard soil and the like. In the operation process, the whole machine needs to turn left and right, the loading module needs to frequently collect the hopper, lift, unload and descend, and the actions are controlled and realized through a hydraulic system of the loader.

The loader hydraulic system consists of a steering hydraulic system and a working hydraulic system. In addition, according to different complete machine configurations, a brake hydraulic system and a fan motor heat dissipation system are also arranged. At present, most of the hydraulic systems of the loaders are quantitative systems. In the operation process of the loader, an engine works in the range of idle speed and highest speed, in order to ensure that the steering of the engine is not heavy when the engine is in the idle speed, the steering pump generally selects large displacement, when the engine is in the high speed and slowly drives a steering wheel, the flow required by a steering system is small, and a large amount of hydraulic oil output by the steering constant delivery pump overflows to an oil tank through an EF (electric-flow) port of a priority valve under the pressure of a steering load, so that a large amount of power loss is caused.

When the loader is in a shoveling working condition, the loading module needs to overcome external resistance, the extending speed of the movable arm oil cylinder is very low, the working hydraulic system is in a high-pressure small-flow state, and a large amount of hydraulic oil output by the working constant delivery pump overflows to an oil tank through a main safety valve of the distribution valve, so that a large amount of power loss is caused.

in addition, the quantitative hydraulic system has poor operation comfort and cannot realize the composite action of steering and loading.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned shortcomings, an object of the present application is to provide a loader all-variable hydraulic system and a loader, which can reduce the fuel consumption rate and reduce the energy loss.

Another object of the present application is to provide a loader and a fully variable hydraulic system thereof, which can improve the operation comfort.

It is yet another object of the present application to provide a loader and a fully variable hydraulic system for a loader that can facilitate installation and piping of the valve block.

In order to achieve at least one of the above purposes, the following technical solutions are adopted in the present application:

An all-variable hydraulic system of a loader, comprising:

A variable displacement pump connected with a load sensitive valve;

the shunt valve block is connected with the output port of the variable pump; the shunt valve block is used for shunting oil output by the variable pump;

The steering module is connected with the shunt valve block; the variable pump drives the steering module through oil output by the shunt valve block;

The pilot module is connected with the flow dividing valve block; the pilot module comprises a pressure reducing valve group and a pilot valve; the pressure reducing valve group is connected with the pilot valve and the load sensitive valve;

the loading module is connected with the shunt valve block; the loading module is connected with the pilot valve; the variable pump drives the loading module through oil output by the shunt valve block;

the brake module is connected with the shunt valve block; the variable pump drives the brake module through oil output by the shunt valve block.

As a preferred embodiment, the diverter valve block comprises a steering pressure compensation valve for making a differential pressure in an oil inlet of the steering module constant; wherein the steering module is connected downstream of the steering pressure compensating valve; the pilot module, the loading module and the braking module are connected to the upstream of the steering pressure compensation valve; the steering module is also connected with the steering pressure compensation valve through a load signal feedback oil way so as to transmit a steering load signal to the steering pressure compensation valve.

as a preferred embodiment, the loading module includes a main control valve set, and a bucket cylinder and a boom cylinder connected to the main control valve set; the main control valve group is connected with the shunt valve block; the main control valve group is connected with the steering module through a first load signal oil way; the main control valve group can reduce the oil flow input by the shunt valve block when the steering load signal is input.

in a preferred embodiment, the master valve set includes a master pressure compensating valve; the spring cavity of the main control pressure compensation valve is connected with the first shuttle valve; the first shuttle valve is connected with the first load signal oil path.

As a preferred embodiment, the pressure relief valve block comprises: a pressure reducing valve, a second shuttle valve, and a solenoid valve; the input port of the reducing valve is connected with the shunt valve block; the output port of the pressure reducing valve is connected with the second shuttle valve and the electromagnetic valve; the electromagnetic valve is connected with the pilot valve; the second shuttle valve is connected with the first shuttle valve through a second load signal oil path; the second shuttle valve is connected to the load sensitive valve.

in a preferred embodiment, a pilot accumulator is further connected between the pressure reducing valve and the solenoid valve.

In a preferred embodiment, the main control valve set includes a high-pressure relief valve and a load pressure relief valve.

As a preferred embodiment, the brake module includes: the brake system comprises a brake charging valve block connected with the shunt valve block, a brake valve connected with the brake charging valve block, a brake oil cylinder connected with the brake charging valve block, and a brake energy accumulator connected with the brake charging valve block.

In a preferred embodiment, the loader all-variable hydraulic system further includes a filter connected to the steering module and the main control valve group.

A loader, comprising: the fully variable hydraulic system of the loader according to any one of the above embodiments.

Has the advantages that:

The all-variable hydraulic system of the loader provided by the embodiment of the application is provided with the variable pump with the load sensitive valve, the steering module, the loading module and the braking module are driven by the load sensitive variable pump, and the displacement of the variable pump can be controlled to change along with the demand of a load by using the load sensitive valve, so that the problem that the pump works under high pressure and large displacement for a long time to consume the power of an engine is avoided, the fuel consumption rate is reduced, and the energy loss is reduced.

Meanwhile, only one load-sensitive variable pump is arranged, so that the power take-off port for the gearbox is fewer, and the installation and connection are convenient. And, when arranging the space and being limited, easy to assemble and arrange. Accordingly, the overall cost is reduced.

Specific embodiments of the present invention are disclosed in detail with reference to the following description and the accompanying drawings, which specify the manner in which the principles of the invention may be employed. It should be understood that the embodiments of the present invention are not so limited in scope. The embodiments of the invention include many variations, modifications and equivalents within the spirit and scope of the appended claims.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments, in combination with or instead of the features of the other embodiments.

It should be emphasized that the term "comprises/comprising" when used herein, is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps or components.

Drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

FIG. 1 is a schematic diagram of a loader fully variable hydraulic system connection provided in an embodiment of the present application;

Fig. 2 is a partially enlarged view of fig. 1.

Detailed Description

In order to make the technical solutions in the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, but not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts shall fall within the protection scope of the present invention.

It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Please refer to fig. 1 and fig. 2. One embodiment of the present application provides a loader all variable hydraulic system adapted for use with a wheel loader. Specifically, the all-variable hydraulic system of the loader comprises: the variable displacement pump comprises a variable displacement pump 1, a shunt valve block 2, a steering module, a pilot module, a loading module and a braking module.

Wherein the variable displacement pump 1 is connected with a load sensitive valve 17. And the shunt valve block 2 is connected with the output port of the variable pump 1. The flow dividing valve block 2 is used for dividing oil output by the variable displacement pump 1. The oil liquid of the variable displacement pump 1 after being divided by the flow dividing valve block 2 can respectively drive the steering module, the loading module and the braking module. Specifically, the flow dividing valve block 2 has a first output port 22, a second output port 23, a third output port 24, and a fourth output port 25.

In the present embodiment, the steering module is connected to the flow dividing valve block 2 to input the oil output from the flow dividing valve block 2. Wherein the diverter module is connected to said first output port 22. The variable displacement pump 1 drives hydraulic oil to enter the steering module through the first output port 22, so that the steering of the loader is controlled. In particular, the steering module may comprise a steering valve 6, and at least one steering cylinder 7. The steering valve 6 is connected to a steering cylinder 7 to control extension or contraction of the steering cylinder 7. The embodiment of the utility model provides an in, turn to the module and include two steering cylinder 7, the first delivery outlet 22 of steering valve 6 and variable pump 1 is connected, and the fluid that the input was controlled to steering valve 6 gets into or leaves steering cylinder 7, controls the extension or the shortening of two steering cylinder 7 respectively.

The pilot module is connected with the shunt valve block 2 to input the oil output by the shunt valve block 2. Wherein the pilot module is connected with the second output port 23. The pilot module includes a pressure reducing valve group 3 and a pilot valve 8 (which may also be referred to as a pilot handle). The pressure reducing valve group 3 is connected with the pilot valve 8 and the load sensitive valve 17.

The loading module is connected with the shunt valve block 2 so as to input oil output by the shunt valve block 2. Wherein the loading module is connected to said third output 24. The loading module is connected with the pilot valve 8. The oil output by the third output port 24 of the variable displacement pump 1 drives the loading module. The brake module is connected with the shunt valve block 2 so as to input oil output by the shunt valve block 2. Wherein the brake module is connected to said fourth output 25. The variable displacement pump 1 drives the brake module through the oil output by the fourth output port 25.

The loader all-variable hydraulic system provided by the embodiment is provided with the variable pump (load-sensitive variable pump for short) 1 with the load-sensitive valve 17, the load-sensitive variable pump 1 drives the steering module, the loading module and the braking module, and the displacement of the variable pump 1 can be controlled to change along with the demand of a load by using the load-sensitive valve 17, so that the problem that the engine power is consumed when the pump works under high pressure and large displacement for a long time is avoided, the fuel consumption rate is reduced, and the energy loss is reduced.

Meanwhile, the all-variable hydraulic system of the loader provided by the embodiment is only provided with one load-sensitive variable pump 1, so that the power take-off port of the gearbox is less, and the installation and connection are convenient. And, when arranging the space and being limited, easy to assemble and arrange. Accordingly, the overall cost is reduced.

To provide comfortable operability and a comfortable steering experience for the operator, the diverter valve block 2 includes a steering pressure compensating valve 26 for maintaining a constant differential pressure in the inlet port of the steering module. As shown in fig. 1 and 2, the input port 21 of the flow dividing valve block 2 is connected to the output port of the variable displacement pump 1. The first outlet 22 is provided downstream of the compensator valve in the direction of flow of the oil output by the variable displacement pump. Correspondingly, the steering module is connected downstream of the steering pressure compensation valve 26. The second output port 23, the third output port 24, and the fourth output port 25 are provided upstream of the steering pressure compensating valve 26. Accordingly, the pilot module, the loading module, and the brake module are connected upstream of the steering pressure compensating valve 26. The second output port 23, the third output port 24, and the fourth output port 25 are connected between the steering pressure compensating valve 26 and the input port 21 of the diverter valve block 2.

The steering module is also connected to the steering pressure compensating valve 26 via a load signal feedback oil line 47 to transmit a steering load signal Ls1 to the steering pressure compensating valve 26. As shown in fig. 1, a load signal feedback oil passage 47 connects the steering valve 6 and the steering pressure compensating valve 26.

By providing the steering pressure compensating valve 26, the oil output by the variable displacement pump 1 is transmitted to the steering valve 6 and the steering cylinder 7 through the steering pressure compensating valve 26 to control the steering function of the loader. The steering pressure compensation valve 26 is used for ensuring that the pressure difference of the port P (main oil inlet) of the steering valve 6 is constant and is not influenced by external load, so that a comfortable steering experience can be provided for an operator.

In the present embodiment, the flow dividing valve block 2 and the pressure reducing valve block 3 are different function valve blocks. The all-variable hydraulic system of the loader provided by the embodiment is respectively provided with the shunt valve block 2 and the pressure reducing valve block 3 according to respective functions to replace an integral valve block, so that the valve block and a pipeline are conveniently arranged, and the fault inspection and the maintenance and the replacement of the valve block are conveniently carried out.

In order to ensure that the steering is prioritized under the condition that the steering and the loading are simultaneously required, the loading module comprises a main control valve group 5, and a bucket cylinder 9 and a movable arm cylinder 10 which are connected with the main control valve group 5. The main control valve group 5 is connected with the third output port 24. The main control valve group 5 is connected with the steering module through a first load signal oil path 41. The first load signal oil path 41 may partially overlap the load signal feedback oil path 47. The main valve group 5 can reduce the oil flow input by (the third output port 24 of) the flow dividing valve block 2 when the steering load signal Ls1 is input. Specifically, the main control valve group 5 includes a main control pressure compensation valve 20. The spring chamber of the main control pressure compensating valve 20 is connected to the first shuttle valve 19. The first shuttle valve 19 is connected to the first load signal oil path 41.

When steering operation is required, the load signal Ls1 directly acts on the spring cavity of the main control pressure compensation valve 20 inside the main control valve group 5 through the first shuttle valve 19, so as to push the valve core of the main control pressure compensation valve 20, so that the valve port of the main control pressure compensation valve 20 is closed to be small, and further, the flow provided to the loading module cylinders (the bucket cylinder 9 and the boom cylinder 10) is reduced, and further, the required flow of the steering cylinder 7 is firstly satisfied, and the priority of the steering function is ensured.

In the present embodiment, the pressure reducing valve group 3 reduces the high-pressure oil output from the variable displacement pump 1 to a low pressure (pilot pressure) that satisfies the pilot valve 8. The pilot valve 8 can control the opening of the main control valve group 5 through pilot pressure. The pressure reducing valve 31 is connected with the load sensitive valve 17, and introduces the pressure after pressure reduction into the load sensitive valve 17, so that sufficient pilot pressure and brake pressure are ensured in the standby state of the loader, and normal use of the loader in the standby state is ensured.

the main function of the pressure reducing valve group 3 is to reduce the high-pressure oil at the outlet of the variable displacement pump 1 to meet the low pressure of the pilot valve 8 through the pressure reducing valve 31. The pressure reducing valve 31 also incorporates therein a solenoid valve 32 and a second shuttle valve 33. The main purpose of the second shuttle valve 33 is to introduce the pilot pressure after the pilot pressure reducing valve 31 into the load sensitive valve 17 to ensure that there is sufficient pilot pressure and brake pressure when standby.

Specifically, the pressure reducing valve group 3 includes: a pressure reducing valve 31, a second shuttle valve 33, and an electromagnetic valve 32. The input port of the pressure reducing valve 31 is connected to the second output port 23. An output port of the pressure reducing valve 31 is connected to the second shuttle valve 33 and the electromagnetic valve 32. The solenoid valve 32 is connected to the pilot valve 8. The second shuttle valve 33 is connected to the first shuttle valve 19 through a second load signal oil path 42. The second shuttle valve 33 is connected to the load sensitive valve 17. As shown in fig. 1, the second shuttle valve 33 may be connected to the load sensitive valve 17 through a load sensitive oil line 46.

The second shuttle valve 33 has two inputs connected to the pressure reducing valve 31 and the first shuttle valve 19, respectively, and an output connected to the load sensitive valve 17. In this embodiment, the steering load signal Ls1 can be transmitted to the first shuttle valve 19 through the first load signal oil path 41, the pressure signal Ls2 formed after comparison at the first shuttle valve 19 is transmitted to the second shuttle valve 33 through the second load signal oil path 42, and then transmitted to the load-sensitive valve 17 through the load-sensitive oil path 46 at the output end of the second shuttle valve 33, and the load-sensitive valve 17 controls the flow output by the variable displacement pump 1 according to the steering load signal.

In order to enable the pilot module to still perform the pilot function in the pump stop state of the variable displacement pump 1, a pilot accumulator 4 is further connected between the pressure reducing valve 31 and the electromagnetic valve 32. As shown in fig. 1, the solenoid valve 32 may be a solenoid directional valve. The electromagnetic directional valve is also communicated with an oil return passage 44, and the oil return passage 44 is communicated with the oil tank 16.

When the loading function is executed, the output oil of the variable displacement pump 1 is simultaneously transmitted to the inlet P5 of the main valve group 5 through the flow dividing valve block 2 installed at the output port of the variable displacement pump 1. The main control valve group 5 is a load sensitive multi-way valve which can perform pressure compensation according to a load pressure signal. Since the center position of the load sensitive multi-way valve of the main valve block 5 is closed, the oil is cut off in the center position of the main valve block 5 without any operation. The main valve group 5 in this design is hydraulically pilot controlled, so both a pressure reducing valve 31 and a pilot valve 8 are required, as well as a pilot accumulator 4.

when the movable arm or the bucket is required to work, the pilot valve 8 is operated, the decompressed pilot pressure oil is transmitted to a valve core pilot cavity of the main control valve group 5, the valve core is pushed to move, a valve port is opened, and the hydraulic oil is transmitted to the movable arm oil cylinder 10 or the bucket oil cylinder 9.

When the type of the main control valve is selected, the main control valve with the valve post-compensation function is selected, the pressure compensation of each load is ensured, the flow provided for the movable arm and the bucket cylinder 9 is not influenced by load change, and the flow is only related to the size of the opening of the valve core of the main control valve, so that the operation comfort and the coordination of composite actions can be effectively improved. The main control valve group 5 comprises a high-pressure overflow valve and a load pressure overflow valve so as to ensure that the system pressure is always kept in a safety range. Specifically, the high-pressure relief valve and the load pressure relief valve are integrated inside the main control valve group 5.

The loader adopting the embodiment is in a low-voltage standby state: when the loader is just started, and under the condition that no operation is executed, the variable pump 1 only needs to overcome the sum of the set pressure of the load sensitive valve 17 and the set pressure of the pressure reducing valve 31, at the moment, the variable pump 1 is in a low-pressure standby state, the swash plate of the variable pump 1 also stays near a zero position, and the output flow is very small.

The loader performs the following steering function: when steering is needed, an operator can rotate a steering wheel, at the same time, a valve port inside the steering valve 66 is opened, a steering load signal Ls1 can be instantly transmitted to the first shuttle valve 19 inside the main control valve group 5, then the pressure Ls2 is output after being compared by the first shuttle valve 19, the final load pressure signal is transmitted to the load sensitive valve 17 of the variable displacement pump 1 after passing through the second shuttle valve 33 inside the pressure reducing valve group 3, the load sensitive valve 17 controls the swash plate piston of the variable displacement pump 1 to move to the right, the swash plate swing angle is increased, the output flow of the variable displacement pump 1 is increased, and therefore enough flow is provided for a steering system.

Meanwhile, the steering load pressure signal Ls1 acts on the right spring chamber of the steering pressure compensating valve 26, so that the flow rate provided by the variable displacement pump 1 to the steering cylinder 7 is stable, is not influenced by load change, and is only related to the speed of the steering wheel.

The loader performs the steering override function as follows: the full-variable hydraulic system of the loader can realize steering priority. The purpose of the steering load signal Ls1 being introduced to the master valve bank 5 is to implement a steering override function. When the steering and loading modules are operated simultaneously, the steering load signal Ls1 directly acts on the spring cavity of the main control pressure compensation valve 20 inside the main control valve group 5 through the first shuttle valve 19, so as to push the valve core valve to close, reduce the flow provided for the loading module oil cylinder, firstly meet the required flow of the steering oil cylinder 7, and ensure the priority of the steering function.

In an embodiment of the present application, the brake module includes: the brake system comprises a brake charging valve block 12 connected with the fourth output port 25, a brake valve 11 connected with the brake charging valve block 12, a brake cylinder 14 connected with the brake charging valve block 12, and a brake accumulator 13 connected with the brake charging valve block 12.

The vehicle braking and parking braking functions are controlled by the brake charging valve block 12, and the brake charging valve block 12 integrates a pressure reducing valve, a charging shuttle valve, an electromagnetic reversing valve and a one-way valve. The pressure reducing valve is used for protecting the brake valve 11 and a pipeline, wherein the inlet pressure supplied to the brake valve 11 cannot exceed a set value. The function of the charging shuttle valve is to ensure that the lower pressure of the two brake accumulators 13 can be charged in time. The function of the check valve is to avoid pressure leakage from the accumulator. The electromagnetic directional valve (not shown) controls the on-off of the oil path of the parking brake cylinder 14

As shown in fig. 1. The loader all-variable hydraulic system further comprises a filter 15 connected with the steering module and the main control valve group 5. The filter 15 is connected to the tank 16, and filters the returned oil and inputs the filtered oil to the tank 16 for storage. The filter 15 is connected to the steering valve 6 through an oil passage 43. The filter 15 is connected with the main control valve group 5 through an oil path 45. The tank 16 is also connected to the pilot valve 8 through an oil return passage 44. The electromagnetic directional valve of the pressure reducing valve group 3 is also connected with the oil return line 44 and leads into the oil tank 16.

The full-variable hydraulic system of the loader is mainly suitable for a wheel loader, and oil output by a variable pump 1 is transmitted to a steering valve 6 and a steering oil cylinder 7 through a pressure compensation valve to control the steering function of the loader. The steering pressure compensation valve 26 is used to ensure that the pressure difference at the port P of the steering valve 6 is constant and is not affected by external loads, thus providing a comfortable steering experience for the operator. The pressure reducing valve group 3 changes high-pressure oil output by the variable displacement pump 1 into low-pressure oil through a pressure reducing valve 31, and the low-pressure oil is supplied to a pilot handle according to requirements. The handle and the main control valve group 5 are both in hydraulic pilot control, the main control valve group 5 is provided with a high-pressure overflow valve and a load pressure overflow valve, and the main control valve group is further provided with a valve back compensation function to improve the operation comfort. The brake charging valve block 12 primarily controls the parking brake and accumulator charging functions.

The all-variable hydraulic system of the loader transmits a steering load pressure signal to the main control valve group 5 to be compared with the working load pressure, the steering priority function is guaranteed, and meanwhile, load pressure signals of a pilot module and a working system (a steering module and a loading module) are collected and fed back to the load sensitive valve 17 of the variable pump 1 in real time, so that the displacement of the variable pump 1 is controlled to change along with the load requirement, and the problem that the engine power is consumed when the pump works under high pressure and large displacement for a long time is avoided.

Based on the same concept, the utility model discloses still provide a loader, as described in the embodiment below. Because the principle of solving the problems and the technical effect which can be obtained by the loader are similar to the fully variable hydraulic system of the loader, the implementation of the loader can refer to the implementation of the fully variable hydraulic system of the loader, and repeated parts are not described again.

The embodiment of this application still provides a loader, includes: the fully variable hydraulic system of a loader as described in any of the above embodiments.

It should be noted that the loader provided in the present embodiment may have any suitable conventional configuration, such as a steering section, a power section for driving the variable displacement pump, and other sections (e.g., a traveling section and a control section). For clearly and briefly explaining the technical solution provided by the present embodiment, the above parts will not be described again, and the drawings in the specification are also simplified accordingly. It should be understood, however, that the present embodiments are not limited in scope thereby.

any numerical value recited herein includes all values from the lower value to the upper value that are incremented by one unit, provided that there is a separation of at least two units between any lower value and any higher value. For example, if it is stated that the number of a component or a value of a process variable (e.g., temperature, pressure, time, etc.) is from 1 to 90, preferably from 20 to 80, and more preferably from 30 to 70, it is intended that equivalents such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 are also expressly enumerated in this specification. For values less than 1, one unit is suitably considered to be 0.0001, 0.001, 0.01, 0.1. These are only examples of what is intended to be explicitly recited, and all possible combinations of numerical values between the lowest value and the highest value that are explicitly recited in the specification in a similar manner are to be considered.

Unless otherwise indicated, all ranges include the endpoints and all numbers between the endpoints. The use of "about" or "approximately" with a range applies to both endpoints of the range. Thus, "about 20 to about 30" is intended to cover "about 20 to about 30", including at least the endpoints specified.

All articles and references disclosed, including patent applications and publications, are hereby incorporated by reference for all purposes. The term "consisting essentially of …" describing a combination shall include the identified element, ingredient, component or step as well as other elements, ingredients, components or steps that do not materially affect the basic novel characteristics of the combination. The use of the terms "comprising" or "including" to describe combinations of elements, components, or steps herein also contemplates embodiments that consist essentially of such elements, components, or steps. By using the term "may" herein, it is intended to indicate that any of the described attributes that "may" include are optional.

A plurality of elements, components, parts or steps can be provided by a single integrated element, component, part or step. Alternatively, a single integrated element, component, part or step may be divided into separate plural elements, components, parts or steps. The disclosure of "a" or "an" to describe an element, ingredient, component or step is not intended to foreclose other elements, ingredients, components or steps.

It is to be understood that the above description is intended to be illustrative, and not restrictive. Many embodiments and many applications other than the examples provided will be apparent to those of skill in the art upon reading the above description. The scope of the present teachings should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are hereby incorporated by reference for all purposes. The omission in the foregoing claims of any aspect of the subject matter that is disclosed herein is not intended to forego such subject matter, nor should the inventors be construed as having contemplated such subject matter as being part of the disclosed inventive subject matter.

Claims

1. An all-variable hydraulic system of a loader, comprising:

A variable displacement pump connected with a load sensitive valve;

2. The all-variable hydraulic system of a loader of claim 1, wherein the diverter valve block includes a steering pressure compensation valve for making a differential pressure in an oil inlet of the steering module constant; wherein the steering module is connected downstream of the steering pressure compensating valve; the pilot module, the loading module and the braking module are connected to the upstream of the steering pressure compensation valve; the steering module is also connected with the steering pressure compensation valve through a load signal feedback oil way so as to transmit a steering load signal to the steering pressure compensation valve.

3. The all-variable hydraulic system of a loader of claim 2, wherein the loading module comprises a main control valve set and a bucket cylinder and a boom cylinder connected with the main control valve set; the main control valve group is connected with the shunt valve block; the main control valve group is connected with the steering module through a first load signal oil way; the main control valve group can reduce the oil flow input by the shunt valve block when the steering load signal is input.

4. The loader all variable hydraulic system of claim 3 wherein the master valve set comprises a master pressure compensating valve; the spring cavity of the main control pressure compensation valve is connected with the first shuttle valve; the first shuttle valve is connected with the first load signal oil path.

5. the loader all variable hydraulic system of claim 4, wherein the pressure relief valve block comprises: a pressure reducing valve, a second shuttle valve, and a solenoid valve; the input port of the reducing valve is connected with the shunt valve block; the output port of the pressure reducing valve is connected with the second shuttle valve and the electromagnetic valve; the electromagnetic valve is connected with the pilot valve; the second shuttle valve is connected with the first shuttle valve through a second load signal oil path; the second shuttle valve is connected to the load sensitive valve.

6. The all-variable hydraulic system of a loader of claim 5, characterized in that a pilot accumulator is further connected between the pressure reducing valve and the solenoid valve.

7. the loader all variable hydraulic system of claim 3 wherein the master valve set includes a high pressure relief valve and a load pressure relief valve.

8. the all-variable hydraulic system of a loader of claim 1, wherein the brake module comprises: the brake system comprises a brake charging valve block connected with the shunt valve block, a brake valve connected with the brake charging valve block, a brake oil cylinder connected with the brake charging valve block, and a brake energy accumulator connected with the brake charging valve block.

9. The loader all variable hydraulic system of claim 3 further comprising a filter connected to the steering module and the master valve set.

10. A loader, characterized by comprising: the all-variable hydraulic system of a loader as claimed in any one of claims 1 to 9.