CN210290307U - Digital control non-interference signal and anti-saturation flow load sensitive integrated valve - Google Patents
Digital control non-interference signal and anti-saturation flow load sensitive integrated valve Download PDFInfo
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- CN210290307U CN210290307U CN201920874206.5U CN201920874206U CN210290307U CN 210290307 U CN210290307 U CN 210290307U CN 201920874206 U CN201920874206 U CN 201920874206U CN 210290307 U CN210290307 U CN 210290307U
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Abstract
The utility model discloses a load sensitive integrated valve with digital control, non-interference signals and anti-saturation flow, which comprises an oil inlet valve group arranged at one end and an oil return valve group arranged at the other end; a combined reversing valve group is arranged between the oil inlet valve group and the oil return valve group; the oil inlet valve bank, the combined reversing valve bank and the oil return valve bank are communicated with each other through a main pressure oil duct, a first pressure sensitive oil duct, a first signal source input oil duct and a main oil return duct which are arranged on the large surface of the valve body, and form a complete full-load sensitive control oil path together with a second pressure sensitive oil duct, a third pressure sensitive oil duct and a sensitive oil path unloading oil duct which are arranged on the oil inlet valve bank; the combined reversing valve group comprises an O-shaped functional reversing valve group, a Yx-shaped functional reversing valve group, a C-shaped functional reversing valve group and an N-shaped functional reversing valve group.
Description
Technical Field
The utility model belongs to computer control hydraulic means field relates to a sensitive integrated valve of load of digital control non-interfering signal and anti saturated flow.
Background
Because various large and medium-sized hydraulic machines have increasingly improved requirements on high efficiency, accurate control, energy conservation and environmental protection, the adoption of the load-sensitive multi-way valve as an energy-saving hydraulic control technology is greatly popularized and applied. As the hydraulic load sensitive control technology belongs to a new hydraulic control technology, the domestic application time is short, and over 80 percent of the domestic currently used load sensitive multi-way valves are all made by foreign famous hydraulic manufacturers such as Germany Rexroth, US HUSCO, US SAUER, Netherlands AMCA, Japan Kawasaki and the like.
1. Sensitive oil circuit control mode adopted by existing load sensitive multi-way valve
1.1 at present, the domestic combined load-sensitive multi-way valve with a flow compensation valve preposed control type generally adopts a pressure signal collected from an A, B oil port of a reversing valve group as sensitive control oil, after comparison of shuttle valves, the pressure is high and is output as a control signal of the valve group, then the pressure signal is compared with the pressure signal output by another shuttle valve of the valve group and is output to an oil inlet valve group to a variable pump system (closed core type) to control a variable mechanism; or a pressure feedback valve is controlled in a constant delivery pump system (open center type), so that the follow-up control of the main working pressure by the load pressure is realized. The control mode has the defects that the requirements on the reliability of a plurality of shuttle valves and the oil cleanliness are particularly high, the fault cannot be generated in each link through which a pressure signal passes, otherwise, the control failure can be caused, and the control mode is particularly obvious under the condition of a combined reversing valve group. In addition, the valve body has more slender small holes in a pressure signal channel, the processing difficulty is higher, the attenuation of pressure signals exists, and the sensitivity and the feedback speed are reduced.
1.2 various load-sensitive multi-way valves including Rexroth in Germany cause partial loss of working flow because a pressure signal is shunted in the flow of a flow compensation valve to an actuating element, so that the running speed under high load can generate a sudden deceleration due to the shunting of the pressure signal, and the motion stability of the actuating element is influenced.
1.3 the pressure signal collected by the domestic multi-valve before or after control type load-sensitive multi-way valve directly controls the valve group flow
The volume compensation valve is compared with the pressure of the main oil way to determine the size of the opening of the oil inlet valve port. However, when the system flow cannot meet the flow demand of the multi-way actuator, the main flow will enter the valve group channel with light load, and the flow supplied to the valve group with heavy load will be reduced or even closed, and the flow is not proportionally distributed, so that the pump flow saturation problem is formed.
1.4 various load-sensitive multi-way valves, including Rexroth, germany, have local pressure losses due to the pressure difference existing in the input flow of the pressure-sensitive multi-way valve, which is a pressure-sensitive signal, which is split in the flow of the flow compensation valve to the actuator, resulting in the pressure of the system working pump being higher than the actual output working pressure.
2. Operation control mode
2.1 at present, the most common load-sensitive multi-way valve mostly adopts a hydraulic proportional pilot control mode, and a pilot handle is operated to realize a reversing function by externally connecting a pilot oil source to the hydraulic proportional pilot valve. The advantage is that the control mode is simple and convenient, and the shortcoming is that manual control precision is relatively poor.
2.2, an electromagnetic control mode integrating manual operation and electric-hydraulic reversing is adopted, and the electromagnetic pilot valve is operated to realize the electro-hydraulic reversing function by externally connecting a pilot oil source or shunting and reducing pressure from a main oil path in the valve into pilot oil. The wireless control system has the advantages of simple control mode, capability of realizing wired or wireless control and no accurate control function.
And 2.3, a programmable PLC electro-hydraulic control mode is adopted, and a pilot oil cylinder is operated by a preset program of the proportional electromagnet, so that the control on the direction and the movement amount of the reversing valve rod is realized. The advantages are simple control mode, basically meeting the control precision of general requirements through the analog control circuit, realizing wired or wireless control, having the disadvantages of lower feedback sensitivity, incapability of adopting rapid interconnection exchange of various programming control modes, incapability of meeting the requirements of fine control and incapability of realizing online control with a computer.
With the rapid development of hydraulic technology, the original control form can not meet the requirements of large and medium-sized engineering machinery and mining machinery on precise and variable control, and in view of the above reasons, a novel digital load-sensitive integrated valve compatible with a computer is required to be developed for the engineering machinery and other hydraulic machinery, so that the applicability is strong, the coverage function is wide, the performance is remarkably improved, and multiple control modes can be selected to meet the requirements of high efficiency, precision, energy conservation, environmental protection and multi-mode automatic control.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a: the load-sensitive integrated valve is exquisite in structure, high in sensitivity and free of interference of acquired pressure signals, a signal channel does not need shuttle valve selection, high in control precision, good in reliability and convenient and fast to maintain, a high-frequency self-adaptive digital control mode is adopted, displacement precision of 0.1-0.2mm can be achieved, control output flow is larger than or equal to 5ml/s, and the defects of the traditional problem are overcome.
The utility model adopts the technical scheme as follows:
a digital control non-interference signal and anti-saturation flow load sensitive integrated valve comprises an oil inlet valve group arranged at one end and an oil return valve group arranged at the other end; a combined reversing valve group is arranged between the oil inlet valve group and the oil return valve group; the oil inlet valve bank, the combined reversing valve bank and the oil return valve bank are communicated with each other through a main pressure oil duct, a first pressure sensitive oil duct, a first signal source input oil duct and a main oil return duct which are arranged on the large surface of the valve body, and form a complete full-load sensitive control oil path together with a second pressure sensitive oil duct, a third pressure sensitive oil duct and a sensitive oil path unloading oil duct which are arranged on the oil inlet valve bank; the combined reversing valve group comprises an O-shaped functional reversing valve group, a Yx-shaped functional reversing valve group, a C-shaped functional reversing valve group and an N-shaped functional reversing valve group. And the four reversing valve groups are all provided with flow compensation valves, and pressure compensation valves are respectively arranged in main oil passage channels leading to the oil passage A and the oil passage B.
In order to solve the defects of the traditional problem, the hydraulic control function is to control the variable mechanism of the hydraulic pump in a closed-center system by utilizing load sensitive pressure, so that the output flow of the hydraulic variable pump is changed along with the load pressure; controlling the opening of the overflow volume with the change of the overflow pressure of the pressure feedback valve along with the change of the load pressure in the open-center system by utilizing the load sensitive pressure; the dynamic balance of the interaction of the pre-valve pressure and the post-valve load sensitive pressure of the flow compensation valve is utilized to ensure that the working speed of the actuating element is not influenced by load change; under the condition of insufficient system flow, the distribution proportion of input flow of each valve group is not influenced by the change of load by the action of a pressure compensation valve arranged in an oil passage of an A, B port, so that the balance of the movement speed of an actuating mechanism controlled by each valve group is maintained; has multiple control functions of protecting the movement direction, the movement speed, the movement process and the overload of oil liquid, and achieves the purposes of simplifying a control mechanism and having obvious energy-saving effect
Wherein: the O-shaped function means that when the reversing valve rod is in the middle position, the oil inlet channel, the oil return channel and two working oil channels connected with the executing element of the valve group are mutually sealed.
The Yx type function means that when the reversing valve rod is in the middle position, the oil inlet channel is closed, the oil return channel of the valve group and the A, B port oil channel connected with the actuating element are communicated, and because the multi-stage reducing throttling groove is processed on the oil-through opening and closing position of the valve rod, the obvious throttling function is realized in the opening and closing section of the valve rod.
The C-shaped function means that when the reversing valve rod is in the middle position, the oil inlet channel and the A port oil channel connected with the working cavity at one end of the actuating element are closed; the oil return passage is communicated with an oil passage at the port B connected with the working cavity at the other end of the execution element and has a throttling function of limiting speed and returning oil.
The N-shaped function means that when the reversing valve rod is in the middle position, the oil inlet channel and the oil channel of the port B connected with the working cavity at one end of the actuating element are closed; the oil return passage is communicated with an A port oil passage connected with the other end working cavity of the execution element and has a throttling function of limiting speed and returning oil.
Furthermore, the oil inlet valve group is provided with four threaded holes, the valve bodies of the combined reversing valve group and the oil return valve group are provided with four corresponding connecting holes, four double-head screws respectively penetrate through the corresponding connecting holes on the valve bodies, and the oil inlet valve group, the combined reversing valve group and the oil return valve group are connected and fastened into a whole by spring pads and nuts. The valve body structure with completely consistent sizes such as the valve body appearance, the common oil inlet hole, the common oil return hole, the common sensitive oil hole, the common signal oil source hole and the common connecting hole is adopted, and the arbitrary combination of the reversing valve groups 1-8 is met.
Furthermore, a sensitive oil way unloading valve is arranged at the rear end of the flow compensation valve, and a pressure limiting valve is inserted in the oil inlet valve group. The oil source is divided in an oil inlet path, and pressure signals are extracted after the difference and the pressure are reduced by a damper and then input into an oil path to be supplied among flow compensation valves arranged in each reversing valve group, when the reversing valve group is in a middle position, no pressure oil enters in front of the flow compensation valves, and an oil cavity at the rear end of the flow compensation valves is opened due to a sensitive oil path unloading valve, so that the whole pressure sensitive oil path is in an unloading state, and a flow compensation valve core is in a closed state under the action of a pressure spring and has no flow output; when a reversing valve rod of any reversing valve group is positioned at a reversing position, main pressure oil enters the front end of the flow compensation valve, and pushes the flow compensation valve core compression spring to move backwards, at the moment, an oil supply path to be supplied in the middle of the flow compensation valve is communicated with an oil cavity at the rear end of the flow compensation valve, pressure oil which is shunted from a main oil path of the oil inlet valve group enters a first pressure sensitive oil path and the oil cavity at the rear end of the flow compensation valve through a first signal oil source input channel to be dynamically balanced with load pressure at the front end of the flow compensation valve so as to control the opening amount of the flow compensation valve core, the pressure of the oil cavity at the rear end of the flow compensation valve has the function of a load sensitive pressure signal LS due to the dynamic balancing action of the pressures at the front end and the rear end, and; because the pressure signals generated by each valve group do not need to be compared and screened and the pressure signal oil source is extracted from the main oil way, the movement speed of each actuating element is not changed, and the control principle and the structural design are relatively simple and have high reliability.
Furthermore, a miniature displacement sensor is arranged at the hydraulic control cover end of each reversing valve group, the end head of the displacement sensor is in seamless contact with the reversing valve rod, and the displacement sensor is used for detecting the displacement of the reversing valve rod and feeding back the displacement to the computer system through an electric signal; when the pilot oil cylinder drives the reversing valve rod to move left and right, the displacement sensor outputs dynamic signals, and the deviation signals are adjusted through a computer system by calling a PID algorithm to control the input quantity of the pilot oil to be randomly controlled by a high-speed electromagnetic switch valve installed on the hydraulic manifold block until the reversing valve rod quickly reaches a preset position.
The digital control function is to feed back the displacement of the reversing valve rod detected by the displacement sensor to an external card-type digital controller or a computer with built-in special software, call a PID algorithm to adjust a deviation signal, and control the input flow of the pilot oil cylinder through a high-speed switch valve to enable the reversing valve rod to quickly reach a preset position. The high-speed switching valve is driven by a PWM signal. The control of the input flow of the pilot oil cylinder is realized by controlling the duty ratio of the PWM signals and the number of the output PWM signals, so that the control of the displacement and the movement direction of the reversing valve rod is realized.
Furthermore, a multi-stage reducing combined throttling groove is adopted at the step of the reversing valve rod for opening and closing the oil passage, and the operating distance is controlled to form reducing combination of the flow area so as to realize stable output of smaller flow and meet the requirement of higher control.
To sum up, owing to adopted above-mentioned technical scheme, the beneficial effects of the utility model are that:
1. the pressure signal is stable and has no flow interference: the flow compensation valve is divided from a main oil way, a fixed damper is adopted in the oil way, a stable pressure signal oil source is output after fixed difference pressure reduction, the flow compensation valve is input into each reversing valve group after the valve group is reversed, and the flow compensation valve has a load sensitive signal function by dynamically balancing with the load pressure at the front end of the flow compensation valve; the pressure signals are stable, and the pressure signals output by the valve banks do not need to be compared and screened; and the speed of an actuator is not changed due to the flow loss usually brought by extracting pressure signal oil behind the flow compensation valve. Due to the fact that the selective shuttle valve arranged in each valve group of the conventional load-sensitive multi-way valve is abandoned, the mechanism design is simplified, and the reliability of the product is remarkably improved.
2. Has the function of anti-saturation flow: the pressure compensation valve is arranged in a channel of each reversing valve group leading to the working oil way, the pressure difference generated by load change compensates the balance thrust of the opening of the flow compensation valve caused by different loads, so that the input flow can provide the flow required by the valve group according to the same proportion change no matter the input flow meets the requirement or the oil supply quantity is insufficient, each executing element can realize stepless proportion speed regulation, and the change of the load pressure is irrelevant, and the problem of anti-saturation flow existing in the prior art is solved.
3. Anti-interference performance: when multiple paths are operated simultaneously, the motion speeds of the actuating elements do not influence and interfere with each other due to the action of the flow compensation valve.
4. Micro-motion characteristics: in a non-digital control mode, the movement stroke of the slide valve is controlled, the variable diameter combination of the throttle area can be changed, stable small flow output is obtained, and operation with high control requirements is realized.
5. Energy conservation and consumption reduction: when the device is applied to a closed-center (adopting a variable pump) system, the middle position is in a low-voltage standby state. In a working condition, the actually required flow output is obtained by controlling the variable mechanism through the sensitive oil circuit in the valve, so that the optimal energy-saving effect is achieved; when the device is applied to an open-center (adopting a fixed displacement pump) system, the middle position is in a low-pressure unloading state. When the flow of the system is larger than the flow required by the actual working condition, the overflow can be started only under the pressure meeting the actual working condition through the dynamic balance action of the pressure of the sensitive oil circuit and the pressure feedback valve, and the overflow does not need to be carried out under the highest pressure set by the system to achieve a certain energy-saving effect; and a main overflow valve installed in the oil inlet valve bank is responsible for unloading under the set highest working condition pressure.
6. Adopt the smart foundry goods of superhigh strength, the structure is exquisite, and the flow is big, and operating pressure reaches 38 Mpa. The condition that the load-sensitive multi-way valve produced in China has the same specification and large volume and the allowable pressure is lower than or equal to 31.5Mpa is improved.
7. Overload protection: and each reversing valve group working oil port can be inserted with an overload valve 4, so that the adjustment of different working pressures of the executing element and the overload protection are realized, and the negative pressure vibration of the system is prevented.
8. The combination of one to eight groups of reversing valve groups can be made according to the requirements of control functions. Nominal pressure of 38Mpa, nominal diameter of 20mm, maximum flow rate of 220L/min; nominal diameter is 28mm, and maximum flow rate is 400L/min.
9. The manipulation form is various: besides the digital control mode, the modes of electro-hydraulic proportional control, electro-hydraulic control, manual control and the like can be selected.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and that for those skilled in the art, other relevant drawings can be obtained according to the drawings without inventive effort, wherein:
FIG. 1 is a view showing the outline of the present invention;
FIG. 2 is a right side view of FIG. 1;
FIG. 3 is a left side view of FIG. 1;
FIG. 4 is a cross-sectional view D-D of FIG. 1;
FIG. 5 is a sectional view A-A of FIG. 4;
FIG. 6 is a cross-sectional view B-B of FIG. 4;
FIG. 7 is an enlarged view of section I of FIG. 5;
FIG. 8 is a cross-sectional view F-F of FIG. 7;
FIG. 9 is a cross-sectional view E-E of FIG. 4;
FIG. 10 is an integrated external view of a high-speed solenoid switch valve;
FIG. 11 is a hydraulic schematic of the open-center (valve control) system of FIG. 1;
FIG. 12 is a hydraulic schematic of the closed-center (pump-controlled) system of FIG. 1;
FIG. 13 is a schematic diagram of a pilot control based on a high speed solenoid valve;
FIG. 14 is a model diagram of a pilot control system;
FIG. 15 is a closed loop control schematic;
FIG. 16MATLAB simulation results;
in the figure:
1-oil inlet valve bank, 2-main overflow valve, 3- 'O' -type functional reversing valve bank, 4-overload valve, 5- 'Yx' -type functional reversing valve bank, 6- 'C' -type functional reversing valve bank, 7- 'N' -type functional reversing valve bank, 8-oil return valve bank, 10-pressure limiting valve, 11-sensitive oil way unloading valve, 12-double-head screw, 13-spring washer, 14-nut, 15-displacement sensor, 16-pilot oil cylinder, 17-pressure feedback valve, 18-flow compensation valve, 19-pressure compensation valve, 22-B oil port, 23-B oil port, 25-main pressure oil passage, 27-main oil inlet passage, 28-A oil inlet passage, 29-A oil passage, 30-oil return passage, 31-reversing valve rod, 32-a first pressure sensitive oil path, 33-a first signal source input oil path, 34-a sensitive oil path unloading oil path, 35-a second pressure sensitive oil path, 36-a second pressure sensitive oil path, 37-a second signal source input oil path, 38-a high-speed switch valve and 39-a pilot integrated block;
a1-first A port oil passage, A2-second A port oil passage, A3-third A port oil passage, A4-fourth A port oil passage,
B1-first B port oil passage, B2-second B port oil passage, B3-third B port oil passage and B4-fourth B port oil passage.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention, i.e., the described embodiments are only some, but not all embodiments of the invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiment of the present invention, all other embodiments obtained by the person skilled in the art without creative work belong to the protection scope of the present invention.
It is noted that relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
A digital control non-interference signal and anti-saturation flow load sensitive integrated valve comprises an oil inlet valve group 1 arranged at one end and an oil return valve group 8 arranged at the other end; a combined reversing valve group is arranged between the oil inlet valve group 1 and the oil return valve group 8; the oil inlet valve group 1, the combined reversing valve group and the oil return valve group 8 are communicated with each other through a main pressure oil duct 25, a first pressure sensitive oil duct 32, a first signal source input oil duct 33 and a main oil return duct 26 which are arranged on the large surface of the valve body, and form a complete full-load sensitive control oil path together with a second pressure sensitive oil duct 35, a third pressure sensitive oil duct 36 and a sensitive oil path unloading oil duct 34 which are arranged on the oil inlet valve group 1; the combined reversing valve group comprises an O-shaped functional reversing valve group 3, a Yx-shaped functional reversing valve group 5, a C-shaped functional reversing valve group 6 and an N-shaped functional reversing valve group 7. And the four reversing valve groups are all provided with flow compensation valves 18, and main oil path channels leading to the oil passage A and the oil passage B are respectively provided with pressure compensation valves 19.
In order to solve the defects of the traditional problem, the hydraulic control function is to control the variable mechanism of the hydraulic pump in a closed-center system by utilizing load sensitive pressure, so that the output flow of the hydraulic variable pump is changed along with the load pressure; controlling the opening of the overflow volume with the change of the overflow pressure of the pressure feedback valve along with the change of the load pressure in the open-center system by utilizing the load sensitive pressure; the dynamic balance of the interaction of the pre-valve pressure and the post-valve load sensitive pressure of the flow compensation valve is utilized to ensure that the working speed of the actuating element is not influenced by load change; under the condition of insufficient system flow, the distribution proportion of input flow of each valve group is not influenced by the change of load by the action of a pressure compensation valve arranged in an oil passage of an A, B port, so that the balance of the movement speed of an actuating mechanism controlled by each valve group is maintained; the device has multiple control functions of oil moving direction, moving speed, moving process and overload protection, and achieves the purposes of simplifying a control mechanism and achieving remarkable energy-saving effect.
The features and properties of the present invention will be described in further detail with reference to the following examples.
Example one
The utility model discloses a load sensitive integrated valve of a digital control non-interfering signal and anti saturation flow that preferred embodiment provided; a main overflow valve 2 for protecting the system from pressure overload, a pressure feedback valve 17 for controlling the overflow pressure by a sensitive oil way, a pressure limiting valve 10 for adjusting the pressure of the sensitive oil way and a sensitive oil way unloading valve 11 are inserted into an oil inlet valve group 1 in the open-center system. A main overflow valve 2 for protecting system pressure overload, a pressure limiting valve 10 for adjusting sensitive oil way pressure, an LS interface for outputting a sensitive control signal and a sensitive oil way unloading valve 11 are inserted into an oil inlet valve group 1 in a closed-core system. In the digital control mode, a reversing valve rod 31 at one end of the reversing valve group is rigidly connected with a pilot oil cylinder piston rod 21 into a whole and is in seamless contact with a displacement sensor 15 arranged on an end cover. The displacement of the reversing valve rod 31 detected by the displacement sensor 15 is fed back to an external card-type digital controller or a computer with built-in special software, and the reversing valve rod 31 quickly reaches a preset position by controlling the input flow of the pilot oil cylinder 16 through an external high-speed switch valve 38, so that the input flow of the pilot oil cylinder 16 is controlled, and the control of the displacement and the movement direction of the reversing valve rod 31 is realized. The other end of the reversing valve group is provided with an operating handle for reversing operation or safe troubleshooting when electric and hydraulic control faults occur.
When in work: the utility model discloses a hydraulic pressure theory of operation: in the closed-center system, fig. 12 shows that when the present embodiment is in the neutral position, since the pressure oil output channels of the respective directional valve blocks and the pressure signal output channels of the sensitive oil paths are both closed, the variable mechanism of the variable pump is in the middle position, the oil pump has no flow output, and the system is in the unloading state. At the moment, all executing elements except the C-type and N-type functional reversing valve groups are in a static state; in an open-center system, fig. 11 shows that when the present embodiment is in a neutral position, pressure signal outputs of the pressure oil output oil paths and the sensitive oil paths of the reversing valve rods 31 are both closed, and since there is no pressure input of the sensitive oil paths at the rear end of the main valve element of the pressure feedback valve 17, pressure oil P1 entering from the oil inlet valve group 1 and pressure oil P2 entering from the oil return valve group 8 are in a fully open state only by overcoming the spring force at the rear end of the main valve element of the pressure feedback valve 17 mounted on the oil inlet valve group 1, and pressure oil P1 returns to the oil tank through an oil return port T1 of the oil inlet valve group 1, so that low-pressure unloading of the main oil paths is realized. At this time, except the C and N functional reversing valve groups 6 and 7, the actuating elements controlled by other reversing valve groups are in a static state.
Example two
In this embodiment, on the basis of the first embodiment, when the "O" type mechanical reversing valve group 3 is operated to right, the pressure oil P1 from the oil inlet valve group 1 enters the front end of the flow compensation valve 18 from the opening of the reversing valve rod 31 with the reducing throttle slot through the main oil inlet channel 27, and after comparing with the load sensitive pressure LS signal entering the rear end of the flow compensation valve spool, the comparison between the main flow pressure and the load sensitive pressure LS signal determines the opening degree of the flow compensation valve spool, that is, the input flow rate. The main pressure oil enters the working cavity at one end of the actuating element through the first A port oil channel 29 through the opening of the flow compensation valve core and the opening of the first A port oil inlet channel 28 and the reversing valve rod 31 by opening the one-way sealing port of the pressure compensation valve 19 at one end. Meanwhile, the return oil of the working cavity at the other end of the actuating element returns to the oil tank from the return oil channel 30 through the first port B oil passage 22 and the T port on the oil return valve 8, and the actuating element moves at the moment; when the O-shaped slide valve can be operated to the left to be in place, pressure oil P1 entering from the oil inlet valve group 1 enters the front end of the flow compensation valve 18 from the opening of the reversing valve rod 31 with the reducing throttling groove through the main oil inlet channel 27, and after being compared with a load sensitive pressure LS signal entering from the rear end of the flow compensation valve core, the main pressure oil enters the other end working cavity of the actuating element through the flow compensation valve core opening, opens the one-way sealing port of the pressure compensation valve 19 at the other end, and enters the first B port oil inlet channel 23 and the opening of the reversing valve rod 31 through the first B port oil channel 22. At the same time, the return oil of the working chamber at one end of the actuator returns to the oil tank from the return oil channel 30 through the T port of the oil return valve 8 via the first a port oil passage 29, and at this time, the actuator moves reversely.
When the reversing valve rod 31 is in the neutral position, oil passages among the oil inlet, the first A port oil passage, the first B port oil passage and the oil return port T are closed, and the executing element is in a static state; in a non-digital control mode, the flow area of the reducing throttling groove is adjusted by controlling the running distance of the reversing valve rod 31, and a certain micro-motion control effect can be obtained.
EXAMPLE III
In this embodiment, on the basis of the first embodiment, when the "Yx" type function directional valve set 5 is operated rightward, the pressure oil P1 from the oil inlet valve set 1 enters the front end of the flow compensation valve 18 through the main oil inlet channel 27 from the opening of the directional valve rod 31 with the reducing throttle slot, and after comparing with the load sensitive pressure LS signal entering the rear end of the flow compensation valve core, the comparison between the main flow pressure and the load sensitive pressure LS signal determines the opening degree of the flow compensation valve core, i.e. the size of the input flow, and the main pressure oil enters the working chamber at one end of the actuator through the opening of the flow compensation valve core and opens the one-way sealing port of the pressure compensation valve 19 at one end, and enters the working chamber at one end of the actuator through the second a port oil inlet channel 28 and the opening of the directional valve rod 31 through. Meanwhile, the return oil of the working cavity at the other end of the actuating element returns to the oil tank from the return oil channel 30 through the second port B oil passage 22 and the T port on the oil return valve 8, and the actuating element moves at the moment; when the Yx-type slide valve can be operated to the left to be in place by the reversing valve rod 31, pressure oil P1 entering from the oil inlet valve group 1 enters the front end of the flow compensation valve 18 from the opening of the reversing valve rod 31 with the reducing throttling groove through the main oil inlet channel 27, and after being compared with a load sensitive pressure LS signal entering from the rear end of the flow compensation valve core, the main pressure oil enters the other end working cavity of the actuating element through the flow compensation valve core opening, opens the one-way sealing port of the pressure compensation valve 19 at the other end, and enters the second port B oil inlet channel 23 and the opening of the reversing valve rod 31 through the second port B oil channel 22. And meanwhile, the return oil of the working cavity at one end of the actuating element returns to the oil tank from the oil return channel 30 through the T port on the oil return valve group 8 through the second A port oil passage 29, and the actuating element moves reversely at the moment.
When the reversing valve rod 31 is in the neutral position, the oil inlet is closed, the oil passages among the second A port oil passage, the second B port oil passage and the oil return port T are communicated, and the executing element is in a floating state; the flow area of the multistage reducing throttling groove is adjusted by controlling the running distance of the reversing valve rod 31, stable micro flow output can be obtained, and accurate control of inching operation is realized.
Example four
In this embodiment, on the basis of the first embodiment, when the "C" type mechanical reversing valve set 5 is operated to the right, the pressure oil P1 from the oil inlet valve set 1 enters the front end of the flow compensation valve 18 from the opening of the reversing valve rod 31 with the reducing throttle slot through the main oil inlet channel 27, and the comparison between the main flow pressure and the load sensitive pressure LS signal after being compared with the load sensitive pressure LS signal entering the rear end of the flow compensation valve spool determines the opening degree of the flow compensation valve spool, that is, the input flow rate. The main pressure oil enters the working cavity at one end of the actuating element through the third A port oil channel 29 through the opening of the flow compensation valve core and the opening of the reversing valve rod 31 through the third A port oil channel 28 by opening the one-way sealing port of the pressure compensation valve 19 at one end. Meanwhile, the return oil of the working cavity at the other end of the actuating element returns to the oil tank from the oil return channel 30 through the third oil passage B22 and the T port on the oil return valve 8, and the actuating element moves at the moment; when the C-shaped slide valve can be operated to the left to be in place, pressure oil P1 entering from the oil inlet valve group 1 enters the front end of the flow compensation valve 18 from the opening of the reversing valve rod 31 with the reducing throttling groove through the main oil inlet channel 27, and after being compared with a load sensitive pressure LS signal entering from the rear end of the flow compensation valve core, the main pressure oil enters the other end working cavity of the actuating element through the flow compensation valve core opening, opens the one-way sealing port of the pressure compensation valve 19 at the other end, and enters the other end working cavity of the actuating element through the third port B oil inlet channel 23 and the opening of the reversing valve rod 31 through the third port B oil channel 22. At the same time, the return oil of the working chamber at one end of the actuator returns to the oil tank from the return oil channel 30 through the third a-port oil passage 29 and the T-port on the oil return valve 8, and at this time, the actuator moves reversely.
When the reversing valve rod 31 is in the neutral position, the oil inlet channel and the third oil duct A are closed, the third oil duct B is communicated with the oil duct of the oil return port T through the reducing throttling groove on the reversing valve rod 31, and the executing element is descended at a limited speed; the flow area of the reducing throttling groove is adjusted by controlling the running distance of the reversing valve rod 31, and a certain micro-motion control effect can be obtained.
Example four
In this embodiment, on the basis of the first embodiment, when the "N" type mechanical reversing valve set 6 is operated rightward, the pressure oil P1 from the oil inlet valve set 1 enters the front end of the flow compensation valve 18 through the main oil inlet channel 27 from the opening of the reversing valve rod 31 with the reducing throttle slot, and after comparing with the load sensitive pressure LS signal entering the rear end of the flow compensation valve core, the comparison between the main flow pressure and the load sensitive pressure LS signal determines the opening degree of the flow compensation valve core, i.e. the size of the input flow, and the main pressure oil enters the working chamber at one end of the actuator through the flow compensation valve core opening and opens the one-way sealing port of the pressure compensation valve 19, the fourth a port oil inlet channel 28 and the opening of the reversing valve rod 31, and the fourth a port oil channel 29. Meanwhile, the return oil of the working cavity at the other end of the actuating element returns to the oil tank from the return oil channel 30 through the fourth port B oil passage 22 and the T port on the oil return valve 8, and the actuating element moves at the moment; when the N-shaped slide valve can be operated to the left to be in place, pressure oil P1 entering from the oil inlet valve group 1 enters the front end of the flow compensation valve 18 from the opening of the reversing valve rod 31 with the reducing throttling groove through the main oil inlet channel 27, and after being compared with a load sensitive pressure LS signal entering from the rear end of the flow compensation valve core, the main pressure oil enters the other end working cavity of the actuating element through the flow compensation valve core opening, opens the one-way sealing port of the pressure compensation valve 19 at the other end, and enters the fourth port B oil inlet channel 23 and the opening of the reversing valve rod 31 through the fourth port B oil channel 22. And meanwhile, the return oil of the working cavity at one end of the actuating element returns to the oil tank from the oil return channel 30 through the T port on the oil return valve group 8 through the fourth A port oil passage 29, and the actuating element moves reversely at the moment.
When the slide valve is in the neutral position, the oil inlet channel and the fourth oil duct at the port B are closed, the fourth oil duct at the port A is communicated with the oil duct at the oil return port T through the reducing throttling groove on the reversing valve rod 31, and the executing element descends at a limited speed; the flow area of the reducing throttling groove is adjusted by controlling the running distance of the reversing valve rod 31, and a certain micro-motion control effect can be obtained.
EXAMPLE five
In this embodiment, on the basis of the first embodiment, the anti-saturation flow performance of each reversing valve group is as follows: when the working condition load is increased, under the influence of the increase of the acting force at the rear end of the pressure compensation valve 19, the pressure at the front end P' is correspondingly increased to ensure that the input pressure oil P1 can smoothly open the pressure compensation valve 19 and enter the oil passage 29 at the port A or the oil passage 22 at the port B, and the balance force between the flow compensation valve 18 and the load sensitive pressure LS signal is compensated, so that when the input total flow is insufficient, the opening of the flow compensation valve 18 of the heavy-load reversing valve group is not influenced by the change of the rear end load, the efficiency of proportional flow distribution of each reversing valve group is kept unchanged, and the reversing valve group has the capability of resisting saturated flow.
EXAMPLE six
In the embodiment, on the basis of the first embodiment, when each reversing valve rod 31 is operated to reverse to the right position, in a closed-center system, a pressure sensitive signal LS for controlling the flow compensation valve 18 is synchronously conveyed from an external oil port through a second sensitive oil passage 35 to be connected with a variable control mechanism of an external variable pump, and the inclination angle of a swash plate of the variable pump can be changed along with the change of the pressure sensitive signal LS, so that the output flow is changed, and the output flow is adapted to the required flow; in an open-center system, the pressure-sensitive signal LS acts on the relief control pressure of the pressure feedback valve 17 through the third sensitive oil passage 36, and the change in relief pressure is regulated by controlling the relief amount. Meanwhile, the changed overflow pressure of the main oil path pressure P1 is fed back through the first sensitive oil path 32 to act on the change of the control valve core opening in the flow balance mechanism of the pressure flow compensation valve 18 inserted in each reversing valve group, so that the output flow after the load pressure change is basically kept unchanged; when the multi-way reversing valve groups are operated simultaneously, the highest pressure of the pressure sensitive signal LS of the flow compensation valve 18 of each reversing valve group is always controlled by the pressure limiting valve 10 inserted in the oil inlet valve group, and the rated pressure of the sensitive signal can be changed by adjusting the pressure limiting valve 10.
EXAMPLE seven
In this embodiment, on the basis of the first embodiment, the overload valve 4 can be inserted into the working oil port A, B of each reversing valve group, and is used for overload protection of each working oil path or secondary selection of working pressure. Because the overload valve 4 has the oil supplementing function, when the oil supply is insufficient due to the rapid movement of the executing element, the oil is rapidly supplemented from the main oil return passage 19, so that the system vibration caused by local negative pressure is eliminated; in open-center systems, the set pressure of the main safety valve 2 inserted in the oil inlet valve bank 1 is higher than 10% of the highest set pressure of the overload valve 4 inserted in each reversing valve bank.
Example eight
This embodiment is on the basis of embodiment one, the utility model discloses a digital manipulation mode is: a pilot control system is formed by adopting a high-speed switch electromagnetic valve group with the reversing frequency of 250Hz/s on the basis of manual control of the multi-way reversing valve, the load-sensitive multi-way valve is improved into a digital load-sensitive integrated valve, and the structure of the digital load-sensitive integrated valve is shown in figure 13. As shown in fig. 14, the pilot control system is that the first high-speed electromagnetic switch valve 38 and the third high-speed electromagnetic switch valve 38 mounted on the pilot manifold block 39 are energized, and the reversing valve rod 31 moves to the right; the second high-speed electromagnetic switch valve 38 and the fourth high-speed electromagnetic switch valve 38 are electrified, and the reversing valve rod 31 moves left; when all the high-speed electromagnetic switch valves 38 are powered off, the multi-way valve reversing valve rod 31 automatically returns to the neutral position under the action of the return spring. The pilot cylinder piston rod 21 is rigidly connected with the reversing valve rod 31 through threads, the electronic displacement sensor 15 is used for detecting the displacement of the reversing valve rod 31 and feeding back the displacement to an external electronic control system, and the electronic control system calls a PID algorithm to adjust a deviation signal until the reversing valve rod 31 reaches a set position. The high-speed electromagnetic opening/closing valve 38 is driven by a PWM signal. The flow control of the pilot control system is realized by controlling the duty ratio of the PWM signals and the number of the output PWM signals, so that the displacement of the reversing valve rod 31 is controlled, and the accurate control of the flow and the direction of each reversing valve group of the multi-way integrated valve is realized.
The mathematical model of the control system of the embodiment and the MATLAB simulation analysis are as follows; the hydraulic pilot control mainly comprises a high-speed electromagnetic switch valve 38 and a pilot hydraulic cylinder 16, and the basic working principle of the pilot cylinder is shown in fig. 14. The pilot cylinder piston rod 21 is rigidly connected to the multi-way valve change-over valve rod 31, so that the sum of the mass of the pilot system piston 20 and the mass of the change-over valve rod 31 is equivalent to M. K is the stiffness of the multi-way valve return spring, D is the pilot system damping, y is the pilot system piston displacement, q is the pilot system input flow, q' is the output flow, P is the pilot cylinder pressure, and A is the pilot cylinder effective area.
Pilot cylinder force balance equation:
leading cylinder flow continuity equation:
Vttotal volume of hydraulic cylinder βeIs the bulk modulus of elasticity of hydraulic oil. Combining (2-1) with (2-2) elimination of P to give:
main valve flow equation:
Cmis the main valve flow coefficient, WmFor area gain of the main valve spool, PAFor pressure at inlet of main valve, PBIs the outlet pressure.
The control system is simplified, assuming a main valve inlet pressure PAAnd the outlet pressure PBAre all approximately constant and equations (2-3) and (2-4) are plotted in small increments at a particular operating pointPerforming sexual treatment, and performing Laplace transformation:
Qm(s)＝Km*Y(s) (2-6)
when the input is the flow of a pilot control system and the output is the displacement of a valve core of the multi-way valve, the open-loop transfer function is as follows:
when the input is the flow of the pilot control system and the output is the working flow of the multi-way valve, the open-loop transfer function is as follows:
the integral saturation phenomenon means that if a system has deviation in one direction, the output of the PID controller is increased due to continuous accumulation of integral action, so that the reversing valve rod 31 of the multi-way valve reaches the extreme position XmaxThe actuator is forced to stay at the limit position, and the control system is out of control, resulting in deterioration of control performance. In order to prevent the reversing valve stem 31 from reaching the extreme position and no longer increasing in valve opening, and to allow the reversing valve stem 31 to enter the integral saturation region and then exit the saturation region quickly, the control system employs an anti-integral saturation PID algorithm. The PID algorithm formula is as follows:
in the equation, flag integrates the saturation flag. If u (k-1) > Umax: if e (k) >0, flag ═ 0; if e (k) <0, flag ═ 1; only negative deviations accumulate. If u (k-1) < -Umax: if e (k) >0, flag ═ 1; if e (k) <0, flag ═ 0; only positive deviations are accumulated.
When the high-speed electromagnetic switch valve 38 is completely opened, the flow rate flowing through the high-speed electromagnetic switch valve 38 is:
the average flow rate through the high-speed solenoid switch valve 38 per PWM signal cycle is:
in the formula: cdIn the flow coefficient of the high-speed electromagnetic switch valve 38, Δ P is an inlet-outlet pressure difference, ρ is a fluid density, a is a maximum flow area, and τ is a duty ratio of the PWM signal.
As shown in fig. 15, the closed-loop control system obtains an output u after the deviation signal e passes through the anti-integral saturation PID module, the control system determines the number of cycles and the duty ratio of the PWM signal for driving the high-speed electromagnetic switch valve 38 according to the value of u, and the pilot control system obtains a flow rate proportional to the duty ratio and the number of cycles, so as to adjust the position of the reversing valve rod 31 and finally reach the target set position. The parameters of the embodiment are simulated by MATLAB with the closed-loop control system as shown in FIG. 15, and the simulation result of the mathematical model shows that the control system has the advantages of good stability and high response speed
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalents and improvements made by those skilled in the art within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (5)
1. A digital control non-interference signal and anti-saturation flow load sensitive integrated valve comprises an oil inlet valve group (1) arranged at one end and an oil return valve group (8) arranged at the other end; the method is characterized in that: a combined reversing valve group is arranged between the oil inlet valve group (1) and the oil return valve group (8); the oil inlet valve group (1) is connected with a pressure feedback valve (17);
the oil inlet valve group (1), the combined reversing valve group and the oil return valve group (8) are communicated with each other through a main pressure oil duct (25), a first pressure sensitive oil duct (32), a first signal source input oil duct (33) and a main oil return duct (26) which are arranged on the large surface of the valve body, and form a complete full-load sensitive control oil path together with a second pressure sensitive oil duct (35), a third pressure sensitive oil duct (36) and a sensitive oil path unloading oil duct (34) which are arranged on the oil inlet valve group (1); the combined type reversing valve group comprises an O-shaped functional reversing valve group (3), a Yx-shaped functional reversing valve group (5), a C-shaped functional reversing valve group (6) and an N-shaped functional reversing valve group (7), flow compensation valves (18) are arranged on the four reversing valve groups, and pressure compensation valves (19) are respectively arranged in main oil path channels leading to an A-port oil path and a B-port oil path.
2. The digitally-controlled, non-interfering signal and anti-saturation flow load-sensitive integrated valve of claim 1, wherein: the oil inlet valve group (1) is provided with four threaded holes, the combined reversing valve group and the oil return valve group (8), four corresponding connecting holes are formed in the valve body, four double-headed screws (12) penetrate through the corresponding connecting holes in the valve bodies respectively, and the oil inlet valve group (1), the combined reversing valve group and the oil return valve group (8) are connected and fastened into a whole through spring pads (13) and nuts (14).
3. The digitally-controlled, non-interfering signal and anti-saturation flow load-sensitive integrated valve of claim 1, wherein: the rear end of the flow compensation valve (18) is provided with a sensitive oil way unloading valve (11), and a pressure limiting valve (10) is inserted in the oil inlet valve bank (1).
4. The digitally-controlled, non-interfering signal and anti-saturation flow load-sensitive integrated valve of claim 1, wherein: a micro displacement sensor (15) is arranged at the hydraulic control cover end of each reversing valve group, the end of the displacement sensor (15) is in seamless contact with the reversing valve rod (31), and the displacement sensor (15) is used for detecting the displacement of the reversing valve rod (31) and feeding back the displacement to a computer system through an electric signal; when the pilot oil cylinder (16) drives the reversing valve rod (31) to move left and right, the displacement sensor (15) outputs dynamic signals, and the deviation signals are adjusted through a computer system by calling a PID algorithm, so that the input quantity of pilot oil is randomly controlled by a high-speed electromagnetic switch valve (38) installed on a hydraulic manifold block (39) until the reversing valve rod (31) quickly reaches a preset position.
5. The digitally-controlled, non-interfering signal and anti-saturation flow load-sensitive integrated valve of claim 4, wherein: a multi-stage reducing combined throttling groove is adopted at the step of the reversing valve rod (31) for opening and closing the oil passage.
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| CN110131230A (en) * | 2019-06-12 | 2019-08-16 | 泸州众大科技液压件有限公司 | A kind of load-sensitive pile-up valve of digital control state no interference signal and anti-saturation flow |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110131230A (en) * | 2019-06-12 | 2019-08-16 | 泸州众大科技液压件有限公司 | A kind of load-sensitive pile-up valve of digital control state no interference signal and anti-saturation flow |
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