Hydraulic system, method for controlling the same and engineering machinery

Abstract

The application relates to the technical field of engineering machinery, and provides a hydraulic system, a control method thereof and engineering machinery. The hydraulic system comprises a proportional valve, a support leg hydraulic system, an electric control switch and a controller. The support leg hydraulic system comprises a multi-way reversing valve and multiple groups of support leg oil cylinders. An oil inlet of the multi-way reversing valve is connected with an oil outlet of the proportional valve. Multiple groups of control oil inlets of the multi-way reversing valve are connected with working oil inlets of the multiple groups of support leg oil cylinders in one-to-one correspondence. The electric control switch and the proportional valve are connected with the controller respectively. The electric control switch is used for sending a multi-stage flow control signal to the controller, so that the controller adjusts the hydraulic oil flow output by the proportional valve according to the multi-stage flow control signal. The hydraulic system saves the arrangement space of the valve group and can adjust and control the stretching and retracting speed of each support leg according to the actual working condition.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, and in particular to a hydraulic system, its control method, and engineering machinery. Background Technology

[0002] Many construction machines are now equipped with outriggers to provide stable support for the vehicle during operation, preventing it from tipping over and ensuring operational safety. These outriggers are typically controlled by a hydraulic system.

[0003] Taking concrete pump trucks as an example, current concrete pump trucks are typically equipped with multiple outriggers. The hydraulic system for each outrigger is equipped with a separate electromagnetic proportional valve. This means that multiple electromagnetic proportional valves control multiple outriggers individually, resulting in high costs and a large space requirement for valve assembly. Furthermore, existing outrigger control systems can only control the deployment or retraction of the outriggers at a single speed, making their operation inflexible. Summary of the Invention

[0004] This invention provides a hydraulic system, its control method, and engineering machinery, to solve the problems of large valve group arrangement space and inability to adjust the extension and retraction speed of outriggers in existing engineering machinery hydraulic systems.

[0005] This invention provides a hydraulic system, including a proportional valve, a outrigger hydraulic system, an electronic switch, and a controller. The outrigger hydraulic system includes a multi-way directional valve and multiple sets of outrigger cylinders. The inlet of the multi-way directional valve is connected to the outlet of the proportional valve, and multiple control ports of the multi-way directional valve are connected one-to-one with the working ports of the multiple sets of outrigger cylinders. The electronic switch and the proportional valve are respectively connected to the controller. The electronic switch is used to send multi-level flow control signals to the controller, so that the controller can adjust the hydraulic oil flow rate output by the proportional valve according to the multi-level flow control signals.

[0006] According to a hydraulic system provided by the present invention, the proportional valve is a proportional multi-way valve, the proportional multi-way valve includes a leg control link, and the oil inlet of the multi-way directional valve is connected to the oil outlet of the leg control link.

[0007] According to a hydraulic system provided by the present invention, at least one actuator is further included, and the proportional multi-way valve further includes at least one actuator control link, wherein the oil outlet of the actuator is connected to the oil outlet of the actuator control link in a one-to-one correspondence.

[0008] According to a hydraulic system provided by the present invention, the outrigger hydraulic system includes a left outrigger hydraulic subsystem and a right outrigger hydraulic subsystem connected in parallel. Both the left outrigger hydraulic subsystem and the right outrigger hydraulic subsystem include the multi-way directional valve and multiple sets of the outrigger cylinders. The oil inlet of the multi-way directional valve of the left outrigger hydraulic subsystem and the oil inlet of the multi-way directional valve of the right outrigger hydraulic subsystem are respectively connected to the oil outlet of the proportional valve.

[0009] According to a hydraulic system provided by the present invention, the left outrigger hydraulic subsystem includes a first multi-way directional valve and a left front vertical outrigger cylinder, a left front horizontal outrigger cylinder, a left rear vertical outrigger cylinder, and a left rear horizontal outrigger cylinder, which are respectively connected to the first multi-way directional valve; the right outrigger hydraulic subsystem includes a second multi-way directional valve and a right front vertical outrigger cylinder, a right front horizontal outrigger cylinder, a right rear vertical outrigger cylinder, and a right rear horizontal outrigger cylinder, which are respectively connected to the second multi-way directional valve.

[0010] According to a hydraulic system provided by the present invention, the multi-way directional valve is a manual multi-way directional valve, which includes multiple directional valves and multiple operating handles. The multiple operating handles are configured to correspond one-to-one with the multiple directional valves and are used to switch the working position of the directional valves.

[0011] The present invention also provides a control method for any of the above-mentioned hydraulic systems, comprising the steps of:

[0012] Adjust the setting of the electronic control switch to output a first flow control signal, and adjust the hydraulic oil flow rate output by the proportional valve based on the first flow control signal to control at least one set of outrigger cylinders to extend to a set position.

[0013] After controlling at least one set of outrigger cylinders to extend to the set position, the setting of the electronic control switch is adjusted so that the electronic control switch outputs a second flow control signal. Based on the second flow control signal, the hydraulic oil flow rate output by the proportional valve is adjusted to control the at least one set of outrigger cylinders to extend from the set position to the target position.

[0014] According to the control method of the hydraulic system provided by the present invention, the hydraulic oil flow rate output by the proportional valve corresponding to the first flow control signal is greater than the hydraulic oil flow rate output by the proportional valve corresponding to the second flow control signal.

[0015] The present invention also provides an engineering machine, including any of the above-mentioned hydraulic systems.

[0016] The engineering machinery provided by the present invention also includes an operator's cab. The electrical control switch includes a left electrical control switch and a right electrical control switch. The left electrical control switch and the right electrical control switch are respectively connected to the controller and are both used to send multi-level flow control signals to the controller. The left electrical control switch is located on the left side of the operator's cab, and the right electrical control switch is located on the right side of the operator's cab.

[0017] The hydraulic system, control method, and engineering machinery provided by this invention utilize proportional valves and multi-way directional valves to individually control multiple sets of outrigger cylinders. Furthermore, an electronically controlled switch is installed between the proportional valve and the multi-way directional valve to control the hydraulic oil flow rate delivered by the proportional valve to the outrigger hydraulic system based on multi-stage flow control signals from the electronically controlled switch, thereby achieving multi-stage control of the extension speed of each set of outrigger cylinders. Compared to existing technologies where each outrigger is equipped with a proportional valve and the outriggers can only extend at a single speed, the hydraulic system of this invention not only saves space for valve assembly but also allows for adjustment and control of the extension speed of each outrigger according to actual working conditions. It offers flexible operation, a relatively simple control logic and electrical control structure, and reduces the cost of the hydraulic system. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the hydraulic system provided by the present invention;

[0020] Figure label:

[0021] 1. Hydraulic pump; 2. Proportional valve;

[0022] 21. Outrigger control link; 22. First boom control link;

[0023] 23. Second boom control link; 24. Third boom control link;

[0024] 25. Fourth boom control link 3. Left outrigger hydraulic subsystem;

[0025] 31. First multi-way directional valve; 311. First directional valve;

[0026] 312. Second directional control valve; 313. Third directional control valve;

[0027] 314. Fourth directional valve; 321. Left front vertical outrigger cylinder;

[0028] 322. Left front horizontal outrigger cylinder; 323. Left rear vertical outrigger cylinder;

[0029] 324. Left rear horizontal outrigger hydraulic cylinder; 4. Right outrigger hydraulic subsystem;

[0030] 41. Second multi-way directional valve; 411. Fifth directional valve;

[0031] 412. Sixth directional control valve; 413. Seventh directional control valve;

[0032] 414. Eighth directional control valve; 421. Right front vertical support leg cylinder;

[0033] 422. Right front horizontal outrigger cylinder; 423. Right rear vertical outrigger cylinder;

[0034] 424. Right rear horizontal outrigger cylinder. 5. Boom hydraulic system;

[0035] 51. First boom cylinder; 52. Second boom cylinder;

[0036] 53. Third boom cylinder; 54. Fourth boom cylinder;

[0037] 61. Left electric control switch; 62. Right electric control switch. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0039] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "first"..."eighth" are numbering for the purpose of clearly indicating product components and do not represent any substantial difference. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances. Furthermore, "a plurality of" means two or more. In the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] This invention provides a hydraulic system applicable to construction machinery with outriggers, such as concrete pump trucks, cranes, and fire trucks. Construction machinery with outriggers typically includes multiple outriggers, and this hydraulic system controls the movement of the outriggers, including their deployment and retraction. This invention uses a concrete pump truck as an example to illustrate the structure and principle of the hydraulic system provided by this invention.

[0042] like Figure 1 The diagram shows the structure of the hydraulic system provided by this invention. The hydraulic system provided in this embodiment includes a proportional valve 2, a outrigger hydraulic system, an electric control switch, and a controller. The outrigger hydraulic system includes a multi-way directional valve and multiple sets of outrigger cylinders. The inlet of the multi-way directional valve is connected to one outlet of the proportional valve 2. Multiple control ports of the multi-way directional valve are connected one-to-one with the working ports of the multiple sets of outrigger cylinders. The electric control switch and the proportional valve 2 are respectively signal-connected or electrically connected to the controller. The electric control switch is used to send multi-stage flow control signals to the controller, so that the controller can adjust the hydraulic oil flow rate output by the proportional valve 2 according to the multi-stage flow control signals. The hydraulic system provided in this embodiment also includes a hydraulic pump 1, and the inlet of the proportional valve 2 is connected to the outlet of the hydraulic pump 1.

[0043] The hydraulic system provided in this invention is applied to construction machinery with outriggers. Each outrigger of the machinery is equipped with multiple outrigger mechanisms to achieve telescopic movement of the outrigger in multiple directions. Each outrigger mechanism includes a set of outrigger cylinders, whose action is driven by the outrigger cylinders. For example, each outrigger is equipped with a horizontal telescopic outrigger mechanism and a vertical telescopic outrigger mechanism. The horizontal telescopic outrigger mechanism is used to drive the outrigger to extend horizontally to expand the outrigger to the outside of the vehicle body or retract it to the inside of the vehicle body, and the vertical telescopic outrigger mechanism is used to drive the outrigger to extend vertically to support the outrigger downward to the ground or retract it upward.

[0044] The multi-way directional valve comprises multiple directional valves, each corresponding to a set of outrigger cylinders. Each directional valve has an inlet, a return port, a first control port, and a second control port. Each set of control ports in the multi-way directional valve corresponds to the first and second control ports of each directional valve. The inlet of the directional valve is connected to the outlet of the proportional valve 2, and the return port is connected to the oil tank. The first control port is connected to the first working port of the outrigger cylinder, and the second control port is connected to the second working port of the outrigger cylinder. By controlling the working position of the directional valve to switch the hydraulic oil flow direction at its first and second control ports, the outrigger cylinder drives the corresponding outrigger mechanism to perform telescopic movement.

[0045] Specifically, the directional control valve spool has a first working position, a neutral position, and a second working position. When the directional control valve spool is switched to the first working position, its first control port is connected to the rodless chamber of the outrigger cylinder, and its second control port is connected to the rod chamber of the outrigger cylinder, for driving the outrigger to extend. When the directional control valve spool is switched to the second working position, its first control port is connected to the rod chamber of the outrigger cylinder, and its second control port is connected to the rodless chamber of the outrigger cylinder, for driving the outrigger to retract. When the directional control valve spool is switched to the neutral position, both its first and second control ports are closed, and the corresponding outrigger cylinder stops moving.

[0046] Among them, the multi-way directional valve is a manual multi-way directional valve, which is equipped with multiple operating handles. Each operating handle corresponds to a different directional valve. The operating handles are used to adjust the valve core position of the corresponding directional valve to switch the working position of the directional valve.

[0047] Furthermore, the directional control valve can be a three-position four-way valve or a three-position six-way valve. When the directional control valve is a three-position six-way valve, it also has a first port and a second port. The first port is connected to the oil tank, and the second port is connected to the outlet of the proportional valve. When the three-position six-way valve is in the neutral position, the first port and the second port are connected. When the three-position six-way valve is in the first working position and the second working position, both the first port and the second port are closed.

[0048] The electric control switch is connected to the proportional valve 2 via a controller, or it can be connected electrically or in other ways. The electric control switch has multiple speed settings. By adjusting the speed setting, the electric control switch outputs a flow control signal corresponding to that setting. Upon receiving this flow control signal, the controller controls the movement of the valve core of the proportional valve 2 to adjust the valve core opening, thereby regulating the hydraulic oil flow rate output by the proportional valve 2. The greater the flow rate output by the proportional valve 2, the faster the outrigger cylinder drives; conversely, the slower the flow rate.

[0049] The hydraulic system provided in this invention uses a proportional valve 2 and a multi-way directional valve to control multiple sets of outrigger cylinders separately. An electronically controlled switch is installed between the proportional valve 2 and the multi-way directional valve to control the flow rate of hydraulic oil supplied by the proportional valve 2 to the outrigger hydraulic system based on the multi-stage flow control signal from the electronically controlled switch, thereby achieving multi-stage control of the extension speed of each outrigger cylinder. Compared to the prior art where each outrigger is equipped with a proportional valve 2 and the outriggers can only extend at a single speed, the hydraulic system of this invention not only saves space for valve assembly but also allows for adjustment and control of the extension speed of each outrigger according to actual working conditions. It offers flexible operation, simple control logic and electrical control structure, and reduces the cost of the hydraulic system.

[0050] In this embodiment of the invention, each set of outrigger cylinders includes at least one cylinder. For example, as shown in Figure 1, the left front vertical outrigger cylinder 321 for controlling the vertical extension and retraction of the left front outrigger includes one cylinder. The rod chamber and rodless chamber of this cylinder are respectively connected to the first control port and the second control port of the first directional valve 311. The left front outrigger is driven to extend and retract vertically through this cylinder. As another example, the left front horizontal outrigger cylinder 322 for controlling the horizontal extension and retraction of the left front outrigger includes two cylinders. The rodless chambers of the two cylinders are connected in series to the first control port of the second directional valve 312, and the rod chambers of the two cylinders are connected in series to the second control port of the second directional valve 312. By driving the left front outrigger to extend and retract horizontally simultaneously through the two cylinders, the horizontal extension and retraction distance of the left front outrigger can be increased.

[0051] In some embodiments of the present invention, the proportional valve 2 is a proportional multi-way valve, which has multiple control links, including a support leg control link 21, wherein the oil inlet of the multi-way directional valve is connected to the oil outlet of the support leg control link 21. Other control links can be used to control the actions of other actuators with higher motion requirements, and each control link has a set of control ports.

[0052] One control port B1 of the outrigger control assembly 21 is connected as an outlet to the inlet of the multi-way directional valve to supply hydraulic oil to the outrigger hydraulic system. The other control port A1 of the outrigger control assembly 21 can be blocked or connected as an outlet to other hydraulic control systems. Furthermore, the hydraulic system provided in this embodiment of the invention also includes at least one actuator, and the proportional multi-way valve further includes at least one actuator control assembly, with each actuator and the outlet of the actuator control assembly corresponding to one another.

[0053] As a specific example, such as Figure 1As shown, the hydraulic system proposed in this embodiment of the invention also includes a boom hydraulic system 5. The boom hydraulic system 5 includes four actuators: a first boom cylinder 51, a second boom cylinder 52, a third boom cylinder 53, and a fourth boom cylinder 54. Each boom cylinder drives the movement of one boom section. The proportional multi-way valve also includes four actuator control lines connected one-to-one with the above four actuators: a first boom control line 22, a second boom control line 23, a third boom control line 24, and a fourth boom control line 25.

[0054] The two oil outlets of the first boom control link 22 are connected to the two working oil ports of the first boom cylinder 51, respectively. The two oil outlets of the second boom control link 23 are connected to the two working oil ports of the second boom cylinder 52, respectively. The two oil outlets of the third boom control link 24 are connected to the two working oil ports of the third boom cylinder 53, respectively. The two oil outlets of the fourth boom control link 25 are connected to the two working oil ports of the fourth boom cylinder 54, respectively. These four boom control links are used to control the extension and retraction of the four boom sections, respectively.

[0055] As another specific example, the hydraulic system provided in this embodiment of the invention also includes a rotary hydraulic system, which includes an actuator, namely a rotary motor. The proportional multi-way valve also includes a rotary control link corresponding to the rotary motor. The oil inlet of the rotary hydraulic system is connected to the oil outlet of the rotary control link, and the rotary control link controls the expansion and contraction of the rotary device.

[0056] Construction machinery typically has multiple outriggers distributed on both sides of the vehicle body, including left and right outriggers. The left outrigger usually includes a left front outrigger and a left rear outrigger, and the right outrigger usually includes a right front outrigger and a right rear outrigger. In this embodiment of the invention, the outrigger hydraulic system includes a left outrigger hydraulic subsystem 3 and a right outrigger hydraulic subsystem 4 connected in parallel. Both the left outrigger hydraulic subsystem 3 and the right outrigger hydraulic subsystem 4 include multi-way directional valves and multiple sets of outrigger cylinders. The inlet ports of the multi-way directional valves in the left outrigger hydraulic subsystem 3 and the right outrigger hydraulic subsystem 4 are respectively connected to the same outlet port of the outrigger control assembly 21.

[0057] The left outrigger hydraulic subsystem 3 includes a first multi-way directional valve 31 and multiple sets of left outrigger cylinders. The right outrigger hydraulic subsystem 4 includes a second multi-way directional valve 41 and multiple sets of right outrigger cylinders. Both the first multi-way directional valve 31 and the second multi-way directional valve 41 include multiple directional valves. The multiple sets of left outrigger cylinders are configured one-to-one with the multiple directional valves of the first multi-way directional valve 31, and the multiple sets of right outrigger cylinders are configured one-to-one with the multiple directional valves of the second multi-way directional valve 41. By setting up two parallel outrigger hydraulic subsystems, the hydraulic oil of the outrigger control link 21 is split into the two outrigger hydraulic subsystems, and the two outrigger hydraulic subsystems can control the simultaneous movement of a pair of left and right outriggers respectively.

[0058] The first multi-way directional valve 31 and the second multi-way directional valve 41 are each equipped with multiple operating handles. The multiple operating handles of each multi-way directional valve are set one-to-one with the multiple directional valves. The operating handles are used to adjust the valve core position of the corresponding directional valve to switch the working position of the directional valve.

[0059] It should be noted that this hydraulic system can also be equipped with only one multi-way directional valve, with all outrigger cylinders connected to this valve, controlling the movement of each outrigger individually. Alternatively, the hydraulic system can be equipped with three or more multi-way directional valves to control the movement of more outriggers. The number of multi-way directional valves can be determined based on the actual number of outriggers, the number of outrigger mechanisms on each outrigger, and the number of control ports on the multi-way directional valves used.

[0060] The outrigger hydraulic system in this embodiment of the invention is used to control the horizontal and vertical extension / retraction movements of four outriggers (including two pairs of outriggers, namely the left front outrigger, the right front outrigger, the left rear outrigger, and the right rear outrigger). The left outrigger hydraulic subsystem 3 includes a first multi-way directional valve 31 and four cylinders connected to it: a left front vertical outrigger cylinder 321, a left front horizontal outrigger cylinder 322, a left rear vertical outrigger cylinder 323, and a left rear horizontal outrigger cylinder 324. The right outrigger hydraulic subsystem 4 includes a second multi-way directional valve 41 and four cylinders connected to it: a right front vertical outrigger cylinder 421, a right front horizontal outrigger cylinder 422, a right rear vertical outrigger cylinder 423, and a right rear horizontal outrigger cylinder 424.

[0061] The first multi-way directional valve 31 includes four directional valves, namely the first directional valve 311, the second directional valve 312, the third directional valve 313 and the fourth directional valve 314. The control ports of these four directional valves are respectively connected to the left front vertical outrigger cylinder 321, the left front horizontal outrigger cylinder 322, the left rear vertical outrigger cylinder 323 and the left rear horizontal outrigger cylinder 324, and are used to control the horizontal extension and vertical extension actions of the four left outrigger cylinders.

[0062] The second multi-way directional valve 41 also includes four directional valves, namely the fifth directional valve 411, the sixth directional valve 412, the seventh directional valve 413 and the eighth directional valve 414. The control ports of these four directional valves are respectively connected to the right front vertical outrigger cylinder 421, the right front horizontal outrigger cylinder 422, the right rear vertical outrigger cylinder 423 and the right rear horizontal outrigger cylinder 424, and are used to control the horizontal extension and vertical extension actions of the four right outrigger cylinders.

[0063] In this embodiment of the invention, the electric control switch is equipped with an electric control handle. When the outrigger is extended or retracted, the operator can adjust the gear of the electric control switch by adjusting the electric control handle as needed, thereby adjusting the valve core opening of the proportional valve 2 and realizing multi-level control of the outrigger extension and retraction speed.

[0064] For example, when horizontally deploying the left front outrigger, first adjust the electric control switch to position 1 using the electric control handle. The controller, based on the flow control signal sent by the electric control switch, controls the proportional valve 2 to output hydraulic oil at the first flow rate. Then, control the second directional valve 312 to switch to the first working position, causing the left front outrigger to deploy horizontally. During the horizontal deployment of the left front outrigger, the electric control switch position can be adjusted as needed, for example, adjusting it to position 2 using the electric control handle. The controller, based on the flow control signal sent by the electric control switch, controls the proportional valve 2 to output hydraulic oil at the second flow rate. This completes the multi-stage speed control for the horizontal deployment of the left front outrigger. Similarly, the vertical lowering operation of the left front outrigger and the horizontal deployment and vertical lowering operations of other outriggers are completed.

[0065] In this system, when deploying or retracting the outriggers, the first through eighth directional valves can be operated sequentially to control the movement of multiple outrigger cylinders. This requires eight operations to complete the horizontal deployment and vertical lowering of all four outriggers. When the left and right outriggers are symmetrically arranged, one directional valve of the first multi-way directional valve 31 and one directional valve of the second multi-way directional valve 41 can be simultaneously switched to the same working position. The outrigger cylinders corresponding to these two directional valves are two sets of outrigger cylinders symmetrically arranged. This ensures that the load on the left and right sides is approximately equal, allowing the outrigger cylinders of a pair of left and right outrigger mechanisms to operate simultaneously. The horizontal deployment and vertical lowering of all four outriggers can be completed in just four operations.

[0066] For example, the operator can simultaneously deploy the left and right front outriggers horizontally. The specific procedure is as follows: First, switch the valve cores of both the second directional valve 312 and the sixth directional valve 412 to their first working position. Then, adjust the electric control handle to position 1, causing the left and right front outriggers to deploy horizontally at the same speed. During the horizontal deployment of the left and right front outriggers, the electric control switch can be adjusted as needed, for example, by adjusting it to position 2 using the electric control handle. The controller then controls the proportional valve 2 to output hydraulic oil at a second flow rate based on the flow control signal sent by the electric control switch. This simultaneously achieves multi-stage speed control for the horizontal deployment of the left and right front outriggers.

[0067] Similarly, the left front leg and the right front leg can be extended vertically at the same time, or the left rear leg and the right rear leg can be extended horizontally at the same time, or the left rear leg and the right rear leg can be extended vertically at the same time.

[0068] The present invention also provides a control method for a hydraulic system as described in the above embodiments. The control method for a hydraulic system provided in this embodiment includes a method for controlling the deployment of outriggers. The control method for the hydraulic system includes the following steps:

[0069] S100, adjust the position of the electronic control switch so that the electronic control switch outputs a first flow control signal, and adjust the hydraulic oil flow rate output by the proportional valve 2 based on the first flow control signal to control at least one set of outrigger cylinders to extend to a set position.

[0070] S200, after controlling at least one set of outrigger cylinders to extend to the set position, adjust the gear of the electronic control switch to make the electronic control switch output a second flow control signal, and adjust the hydraulic oil flow rate output by the proportional valve 2 based on the second flow control signal to control the at least one set of outrigger cylinders to extend from the set position to the target position.

[0071] The target position is the desired position reached when the outrigger extends in any direction. The set position is the position of the outrigger cylinder from the starting position to the target position. Optionally, the set position is closer to the target position than the starting position.

[0072] During the deployment of one or more outriggers, the electric control handle on the electric control switch is operated to output different flow control signals. The hydraulic oil flow rate output by proportional valve 2 is adjusted according to these different flow control signals to achieve multi-stage control of the outrigger deployment speed, thus realizing variable speed control of the outriggers. Throughout the entire deployment process, the extension speed of the outriggers can be flexibly adjusted by changing the setting of the electric control switch according to the actual situation.

[0073] Step S100, controlling at least one set of outrigger cylinders to extend to a set position, further includes: controlling the directional control valve corresponding to the at least one set of outrigger cylinders to switch to a first working position. The working position of the directional control valve can be switched by operating the operating handle on the multi-way directional control valve. By combining the electric control handle and the operating handle of the multi-way directional control valve, multi-level speed control can be performed individually on each outrigger.

[0074] In the above steps for controlling the deployment of the outriggers, one outrigger can be deployed or retracted at a time, or multiple outriggers can be deployed or retracted at once. Steps S100-S200 are repeated until all outriggers have been deployed.

[0075] In the above embodiment, the hydraulic oil flow rate output by the proportional valve 2 corresponding to the first flow control signal is greater than the hydraulic oil flow rate output by the proportional valve 2 corresponding to the second flow control signal. That is, before the outrigger cylinder reaches the target position, by adjusting the hydraulic oil flow rate output by the proportional valve 2, the horizontal outrigger cylinder decelerates before reaching the target position, thereby achieving precise control of horizontal deployment and improving operational safety.

[0076] In actual operation, depending on the actual situation, the above-mentioned deceleration movement can be performed only on the horizontal deployment operation of the outriggers; or only on the vertical deployment operation of the outriggers; or both the horizontal deployment operation and the vertical deployment operation of the outriggers can be performed.

[0077] The hydraulic system control method provided in this embodiment of the invention also includes a method for controlling the retraction of outriggers. During the retraction of one or more outriggers, the hydraulic oil flow rate output by the proportional valve 2 can be adjusted according to different flow control signals output by the electronic control switch, thereby enabling multi-level control of the outrigger retraction speed. Furthermore, by reducing the hydraulic oil flow rate output by the proportional valve 2, precise control of the outrigger retraction can be achieved. The control principle is similar to the outrigger deployment control method described in the above embodiments, and will not be repeated here.

[0078] The present invention also provides an engineering machine, which can be a fire truck, a concrete pump truck, or a crane, etc., and includes the hydraulic system described in any of the above embodiments. The engineering machine is equipped with multiple outriggers, each outrigger having multiple sets of outrigger cylinders, each set of outrigger cylinders being used to drive the outrigger to extend or retract in one direction (such as horizontal or vertical).

[0079] Furthermore, the engineering machinery provided in this embodiment of the invention also includes an operator's cab, and the electrical control switches include a left electrical control switch 61 and a right electrical control switch 62. The left electrical control switch 61 and the right electrical control switch 62 are respectively signal-connected or electrically connected to the controller. Both the left electrical control switch 61 and the right electrical control switch 62 are used to send multi-level flow control signals to the controller. The left electrical control switch 61 is located near the left side of the operator's cab, and the right electrical control switch 62 is located near the right side of the operator's cab.

[0080] The first multi-way directional valve 31 is located on the left side of the operator's cab, and the second multi-way directional valve 41 is located on the right side. The operator, from the left side of the operator's cab, deploys multiple outriggers on the left side by operating the left electronic control switch 61 and the first multi-way directional valve 31. From the right side of the operator's cab, the operator deploys multiple outriggers on the right side by operating the right electronic control switch 62 and the second multi-way directional valve 41. When deploying the outriggers, the operator can observe the movement of the external outriggers, reducing misoperation and ensuring operational safety.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydraulic system, characterized in that, The system includes a proportional valve, an outrigger hydraulic system, an electronic switch, and a controller. The outrigger hydraulic system comprises a left outrigger hydraulic subsystem and a right outrigger hydraulic subsystem connected in parallel. Both the left and right outrigger hydraulic subsystems include a multi-way directional valve and multiple sets of outrigger cylinders. The multi-way directional valve is a manual multi-way directional valve, comprising multiple valves with multiple operating handles. Each operating handle corresponds to one of the multiple directional valves and is used to switch the operating position of the directional valve. The left outrigger hydraulic subsystem... The inlet ports of the multi-way directional valves of the outrigger hydraulic subsystem and the right outrigger hydraulic subsystem are respectively connected to the outlet ports of the proportional valve. Multiple control ports of the multi-way directional valve are connected one-to-one with the working ports of multiple outrigger cylinders. The electronic switch and the proportional valve are respectively connected to the controller. The electronic switch is used to send multi-level flow control signals to the controller, so that the controller can adjust the hydraulic oil flow rate output by the proportional valve according to the multi-level flow control signals. The controller is configured to: receive a first flow control signal and a second flow control signal output by the electronic control switch at different positions; adjust the hydraulic oil flow rate output by the proportional valve based on the first flow control signal to control at least one set of outrigger cylinders to extend to a set position; after controlling at least one set of outrigger cylinders to extend to the set position, adjust the hydraulic oil flow rate output by the proportional valve based on the second flow control signal to control the at least one set of outrigger cylinders to extend from the set position to a target position; wherein the hydraulic oil flow rate output by the proportional valve corresponding to the first flow control signal is greater than the hydraulic oil flow rate output by the proportional valve corresponding to the second flow control signal.

2. The hydraulic system according to claim 1, characterized in that, The proportional valve is a proportional multi-way valve, which includes a support leg control assembly. The oil inlet of the multi-way directional valve is connected to the oil outlet of the support leg control assembly.

3. The hydraulic system according to claim 2, characterized in that, It also includes at least one actuator, and the proportional multi-way valve also includes at least one actuator control link, with the oil outlet of the actuator and the actuator control link connected one-to-one.

4. The hydraulic system according to claim 1, characterized in that, The left outrigger hydraulic subsystem includes a first multi-way directional valve and a left front vertical outrigger cylinder, a left front horizontal outrigger cylinder, a left rear vertical outrigger cylinder, and a left rear horizontal outrigger cylinder, which are respectively connected to the first multi-way directional valve; the right outrigger hydraulic subsystem includes a second multi-way directional valve and a right front vertical outrigger cylinder, a right front horizontal outrigger cylinder, a right rear vertical outrigger cylinder, and a right rear horizontal outrigger cylinder, which are respectively connected to the second multi-way directional valve.

5. A control method for a hydraulic system as described in any one of claims 1-4, characterized in that, Including the following steps: Adjust the setting of the electronic control switch to output a first flow control signal, and adjust the hydraulic oil flow rate output by the proportional valve based on the first flow control signal to control at least one set of outrigger cylinders to extend to a set position. After controlling at least one set of outrigger cylinders to extend to the set position, the setting of the electronic control switch is adjusted so that the electronic control switch outputs a second flow control signal. Based on the second flow control signal, the hydraulic oil flow rate output by the proportional valve is adjusted to control the at least one set of outrigger cylinders to extend from the set position to the target position.

6. The control method for the hydraulic system according to claim 5, characterized in that, The hydraulic oil flow rate output by the proportional valve corresponding to the first flow control signal is greater than the hydraulic oil flow rate output by the proportional valve corresponding to the second flow control signal.

7. An engineering machinery, characterized in that, Includes the hydraulic system as described in any one of claims 1-4.

8. The engineering machinery according to claim 7, characterized in that, It also includes an operating room. The electrical control switches include a left electrical control switch and a right electrical control switch. The left electrical control switch and the right electrical control switch are respectively connected to the controller and are both used to send multi-level flow control signals to the controller. The left electrical control switch is located on the left side of the operating room, and the right electrical control switch is located on the right side of the operating room.

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