Hydraulic control system and traction type aerial ladder vehicle

Abstract

The invention relates to the technical field of hydraulic control, and provides a hydraulic control system and a traction type scaling ladder truck, the hydraulic control system comprises a power assembly, a hand-operated reversing valve assembly, an execution assembly and an electric control reversing valve assembly; the manual reversing valve assembly has a first state, a second state and a third state; in the first state, the hand-operated direction valve assembly is communicated with the execution assembly in the forward direction, and the hand-operated direction valve assembly is disconnected from the electric control direction valve assembly. In the second state, the manual reversing valve assembly is reversely communicated with the execution assembly, and the manual reversing valve assembly is disconnected from the electric control reversing valve assembly; and in the third state, the hand-operated direction valve assembly is disconnected from the execution assembly, and the hand-operated direction valve assembly is communicated with the electric control direction valve assembly. According to the hydraulic control system, operation priority control is automatically achieved through a mechanical structure, and the out-of-control and dangerous conditions caused when the electric control reversing valve assembly breaks down can be effectively avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic control, in particular to a hydraulic control system and a traction ladder truck. BACKGROUND

[0002] In the prior art, in order to meet the dual needs of automatic electric control and emergency manual operation of the equipment, a common solution is to parallelly arrange an electric control valve group and a manual control valve group in the main hydraulic oil circuit between the oil pump and the execution element (such as a hydraulic cylinder or a hydraulic motor) of the hydraulic system. The electric control valve group is usually composed of elements such as electromagnetic directional valves, and receives electric signal instructions from the controller to switch the oil circuit, so as to realize remote or automatic control of the execution element. The manual control valve group is usually composed of a manual directional valve, which allows the operator to switch the oil circuit by directly operating the handle and other mechanisms, so as to realize local manual control of the execution element.

[0003] However, due to the complex and changeable field conditions, and the operator's negligence or misjudgment of the system state, the electric control valve group and the manual control valve group may be simultaneously opened during operation. When the two valve groups are simultaneously opened, the pressure oil from the oil pump will simultaneously act on the execution element through the two parallel oil circuits, causing the control instructions and power input received by the execution element to conflict and become chaotic. This power chaos may cause the execution element to malfunction and the equipment to lose control, or even cause abnormally high pressure or flow impact in the hydraulic system, thereby damaging the core components such as the hydraulic valve group, the oil pump and the execution element, and even possibly damaging the entire mechanical equipment, posing a serious threat to production safety and equipment reliability. SUMMARY

[0004] The first aspect of the present application provides a hydraulic control system to solve the defect that two valve groups may be simultaneously opened in the prior art, and automatically realizes operation priority control through mechanical structure. In the electric control operation process, if manual operation is started, the hydraulic control system will immediately switch to manual mode and interrupt the electric control oil circuit, which can effectively avoid the out-of-control and dangerous situations caused by the failure of the electric control directional valve assembly.

[0005] The second aspect of the present application provides a traction ladder truck.

[0006] The hydraulic control system provided by the present application comprises: a power assembly for providing hydraulic oil; a manual directional valve assembly connected downstream of the power assembly, and the downstream of the manual directional valve assembly is connected with an oil tank, the manual directional valve assembly comprising a first state, a second state and a third state; an actuator component connected to the downstream of the manual reversing valve component, the actuator component being used to convert hydraulic energy into mechanical energy for output; an electrically controlled reversing valve assembly connected to the oil tank; in a first state, the manual reversing valve assembly is forwardly connected to the actuator assembly, and the manual reversing valve assembly is disconnected from the electrically controlled reversing valve assembly; in a second state, the manual reversing valve assembly is reversely connected to the actuator assembly, and the manual reversing valve assembly is disconnected from the electrically controlled reversing valve assembly; in a third state, the manual reversing valve assembly is disconnected from the actuator assembly, and the manual reversing valve assembly is connected to the electrically controlled reversing valve assembly.

[0007] According to the hydraulic control system provided by the present invention, the electronically controlled reversing valve assembly includes: A first electrically controlled reversing valve is connected between the manual reversing valve assembly and the actuator assembly; A proportional reversing valve is connected between the manual reversing valve assembly and the oil tank, and is used to control the flow of hydraulic oil in the first electronically controlled reversing valve.

[0008] According to the hydraulic control system provided by the present invention, the electrically controlled reversing valve assembly further comprises a valve body, wherein the valve body is provided with a mounting portion; The first electrically controlled reversing valve is detachably mounted on the mounting portion, and / or the proportional reversing valve is detachably mounted on the mounting portion.

[0009] According to the hydraulic control system provided by the present invention, the manual reversing valve assembly includes a plurality of six-way valves, each of which is provided with an execution position and a manual-electric conversion position, and the execution position of each six-way valve is respectively connected to the execution assembly; The manual-electric conversion positions of all the six-way valves are arranged in series, and the manual-electric conversion position of each six-way valve can independently disconnect the connection between the electric-controlled reversing valve assembly and the power assembly.

[0010] According to the hydraulic control system provided by the present invention, the execution assembly includes a plurality of execution components, each of which includes a hydraulic cylinder or a hydraulic motor; The plurality of actuators are connected to the plurality of six-way valves in a one-to-one correspondence, and at least one pair of the plurality of actuators arranged in pairs and the six-way valves is connected to the electrically controlled reversing valve assembly in a corresponding manner.

[0011] The traction-type aerial ladder truck provided by the present invention comprises a vehicle body and a hydraulic control system according to any one of claims 1 to 4; The execution components include: A luffing cylinder connected to the manual reversing valve assembly, the luffing cylinder being used to control the angle between the ladder arm of the vehicle body and the ground; A rotary hydraulic motor connected to the manual directional valve assembly, the rotary hydraulic motor being used to control the rotation angle of the ladder arm of the vehicle body; A track telescopic hydraulic motor connected to the manual directional valve assembly, the track telescopic hydraulic motor being used to control the extension and contraction of the ladder arm of the vehicle body; A material lifting hydraulic motor connected to the manual directional valve assembly and the electrically controlled directional valve assembly, the material lifting hydraulic motor being used to control the rising or lowering of the material platform of the vehicle body.

[0012] According to the present application, the first position detection member, the second position detection member, the third position detection member and the fourth position detection member are arranged along the length direction of the ladder arm in sequence; the electrically controlled directional valve assembly is electrically connected to the first position detection member, the second position detection member, the third position detection member and the fourth position detection member respectively. The first position detection member is used to determine the initial position of the material platform; the second position detection member is used to determine the rising acceleration position or the lowering deceleration position of the material platform; the third position detection member is used to determine the rising deceleration position or the lowering acceleration position of the material platform; and the fourth position detection member is used to determine the preset target position of the material platform.

[0013] According to the present application, the traction type aerial ladder truck further comprises: A one-way valve, the oil outlet of the one-way valve being connected to the first end of the track telescopic hydraulic motor, and the oil inlet of the one-way valve being connected to the second end of the track telescopic hydraulic motor; A balance valve, the pressure oil port of the balance valve being connected to the manual directional valve assembly, the return oil port of the balance valve being connected to the first end of the track telescopic hydraulic motor, the oil outlet of the one-way valve being connected to the return oil port of the balance valve, and the pilot control port of the balance valve being connected to the second end of the track telescopic hydraulic motor.

[0014] According to the present application, the electrically controlled directional valve assembly further comprises: A second electrically controlled directional valve, one end of the second electrically controlled directional valve being connected to the oil tank, and the other end of the second electrically controlled directional valve being connected to the pressure oil port of the balance valve; A third electrically controlled directional valve, one end of the third electrically controlled directional valve being connected to the oil tank, and the other end of the third electrically controlled directional valve being connected to the oil inlet of the one-way valve.

[0015] According to the present application, the traction type aerial ladder truck further comprises: An upper limit piece is electrically connected with the second electrically controlled reversing valve, and is used for determining an elongation limit position of the ladder arm. In a case where the upper limit piece is triggered, the second electrically controlled reversing valve connects the manual reversing valve assembly and the oil tank. A lower limit piece is electrically connected with the third electrically controlled reversing valve, and is used for determining a shortening limit position of the ladder arm. In a case where the lower limit piece is triggered, the third electrically controlled reversing valve connects the manual reversing valve assembly and the oil tank.

[0016] The hydraulic control system provided by the application establishes a physical exclusion mechanism of an operation channel at a hydraulic level through a three-state oil path design of the manual reversing valve assembly. Specifically, when manual operation is activated (in a first or second state), a bridge port oil path between the manual reversing valve assembly and the electrically controlled reversing valve assembly is forcibly closed, thereby cutting off the pressure oil supply of the electrically controlled reversing valve assembly from the source, and completely avoiding the possibility that the manual system and the electrically controlled system simultaneously supply oil to the execution element.

[0017] Compared with the parallel valve group scheme in the background art which relies on the judgment of an operator, in the hydraulic control system provided by the application, the operation priority control is automatically realized through a mechanical structure. In an electrically controlled operation process, if manual operation is started, the hydraulic control system will immediately switch to a manual mode and interrupt the electrically controlled oil path, thereby forming a fail-safe mechanism. Taking a towed aerial ladder as an example, the equipment can be urgently taken over through manual operation in a case where the electrically controlled reversing valve assembly fails, so that the out-of-control and dangerous situation caused by the failure of the electrically controlled reversing valve assembly can be effectively avoided, and the personal safety of the operator and the safety of the on-site operation can be effectively ensured. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0019] Figure 1 is a hydraulic principle schematic diagram of the hydraulic control system of the embodiment of the application.

[0020] Figure 2 is Figure 1 is a hydraulic principle schematic diagram in a manual control state.

[0021] Figure 3 is Figure 1 is one of hydraulic principle schematic diagrams in an electrically controlled state.

[0022] Figure 4 isFigure 1 Fig. 2 is a hydraulic principle diagram of the electric control state.

[0023] Figure 5 Fig. 1 is a structural schematic diagram of a traction ladder truck provided by an embodiment of the present application.

[0024] Reference signs: 100: power assembly; 200: oil tank; 300: manual reversing valve assembly; 310: six-way valve; 400: execution assembly; 410: luffing oil cylinder; 420: slewing hydraulic motor; 430: track telescopic hydraulic motor; 431: check valve; 432: balance valve; 440: material lifting hydraulic motor; 500: electric control reversing valve assembly; 510: first electric control reversing valve; 520: proportional reversing valve; 530: second electric control reversing valve; 540: third electric control reversing valve; 600: vehicle body; 610: ladder arm; 620: material platform. DETAILED DESCRIPTION

[0025] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0026] In the description of the embodiments of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms “connected”, “connected” should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0027] In the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature is “on” or “under” the second feature, which can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature can be directly above or obliquely above the second feature, or only means that the horizontal height of the first feature is higher than that of the second feature. The first feature can be directly below or obliquely below the second feature, or only means that the horizontal height of the first feature is less than that of the second feature.

[0028] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0029] Figure 1 is a hydraulic principle schematic diagram of the hydraulic control system of the embodiment of the application.

[0030] Referring to Figure 1 , the first aspect of the embodiment of the application provides a hydraulic control system; the hydraulic control system comprises a power assembly 100, a manual reversing valve assembly 300, an execution assembly 400 and an electrically controlled reversing valve assembly 500. The power assembly 100 is used to provide high-pressure hydraulic oil, and the specific form of the power assembly 100 can be adaptively selected according to the actual situation, for example, the power assembly 100 can be selected in the structural form of a prime mover driving a hydraulic pump, wherein the prime mover can be selected as an electric motor or an internal combustion engine, and the hydraulic pump can be selected as a gear pump, a plunger pump or the like.

[0031] It should be noted that "downstream" or "upstream" refers to the direction of energy transmission along the hydraulic oil circuit, and the side with higher energy of the components is the "upstream", and the side with lower energy of the components is the "downstream", for example, the side of the manual reversing valve assembly 300 facing the power assembly 100 is used to receive high-pressure hydraulic oil provided from the power assembly 100, therefore, the side of the manual reversing valve assembly 300 facing the power assembly 100 is called the upstream of the manual reversing valve assembly 300, and by analogy, the side of the manual reversing valve assembly 300 facing the execution assembly 400 is called the downstream of the manual reversing valve assembly 300, and other components in this article can be understood with reference to this; the above definition of "downstream" or "upstream" is only a schematic explanation given by the present application for the purpose of clarity, and is not a specific limitation of each embodiment of the present application.

[0032] The manual reversing valve assembly 300 is arranged downstream of the power assembly 100 and connected with the oil tank 200, and the manual reversing valve assembly 300 can be selected as a manual multi-way reversing valve, for example, a manual three-position six-way reversing valve; the execution assembly 400 is connected downstream of the manual reversing valve assembly 300, and the execution assembly 400 is used to convert hydraulic energy into mechanical energy for output, for example, the execution assembly 400 is selected as a hydraulic motor, and the hydraulic motor can convert hydraulic energy into rotary motion.

[0033] The electrically controlled reversing valve assembly 500 is connected to the downstream of the manual reversing valve assembly 300 and is connected to the oil tank 200. The electrically controlled reversing valve assembly 500 can use a solenoid valve, for example, a three-position four-way solenoid valve and a two-position two-way solenoid valve; the electrically controlled reversing valve assembly 500 can realize control of the execution assembly 400 by remote control. For example, in the process of controlling the material trolley of the towed aerial ladder truck, the operator can control the electrically controlled reversing valve assembly 500 through the handle at a distance, and then realize the control of the rise and fall of the material platform 620 at a remote safe position. Optionally, the rising and falling speed of the material platform 620 can also be remotely controlled by the electrically controlled reversing valve assembly 500.

[0034] Figure 2 yes Figure 1 Schematic diagram of hydraulic principle in manual control state; Figure 3 yes Figure 1 One of the schematic diagrams of the hydraulic principle in the electronic control state; Figure 4 yes Figure 1 The second schematic diagram of the hydraulic principle in the electronic control state.

[0035] See Figure 2 to Figure 4 In this embodiment, the manual reversing valve assembly 300 includes three working states.

[0036] First state: the manual reversing valve assembly 300 connects the power assembly 100 and the actuator assembly 400 in a positive direction (e.g. Figure 2 The oil flows to the rodless chamber of the hydraulic cylinder through port A1), and at the same time, the connection with the electronically controlled reversing valve assembly 500 is disconnected. During this process, the manual reversing valve assembly 300 controls the operation of the actuator 400, and no hydraulic oil flows in the electronically controlled reversing valve assembly 500.

[0037] Second state: The manual reversing valve assembly 300 connects the power assembly 100 and the actuator assembly 400 in reverse (for example, the oil flows to the rod chamber of the hydraulic cylinder through the B1 port), and also disconnects the connection with the electronically controlled reversing valve assembly 500. During this process, the manual reversing valve assembly 300 controls the operation of the actuator assembly 400, and hydraulic oil does not flow in the electronically controlled reversing valve assembly 500.

[0038] The third state: the manual reversing valve assembly 300 is disconnected from the actuator assembly 400 and is connected to the electric control reversing valve assembly 500 through the bridge port C (eg Figure 3 and Figure 4 The hydraulic oil flows to the electronically controlled reversing valve assembly 500 through port C). At this time, the hydraulic oil starts from the automatic power assembly 100, flows through the manual reversing valve assembly 300 to the electronically controlled reversing valve assembly 500, and the electronically controlled reversing valve assembly 500 realizes the operation control of the executive assembly 400 by connecting or disconnecting the connection with the executive assembly 400.

[0039] It should be noted that, since the valve assembly can generally reverse the direction of the oil circuit, for the convenience of description, the "positive communication" and "reverse communication" are defined in this paper, and the "positive communication" and "reverse communication" only express the two flow directions of hydraulic oil through the components. Taking the variable amplitude oil cylinder 410 and the manual reversing valve assembly 300 as an example, after the manual reversing valve assembly 300 and the variable amplitude oil cylinder 410 are connected, the piston of the variable amplitude oil cylinder 410 is in the process of extension, then the manual reversing valve assembly 300 and the variable amplitude oil cylinder 410 are "positively communicated"; after the position of the valve core in the manual reversing valve assembly 300 changes, after the manual reversing valve assembly 300 and the variable amplitude oil cylinder 410 are connected, the piston of the variable amplitude oil cylinder 410 is in the process of retraction, then the manual reversing valve assembly 300 and the hydraulic cylinder are "reverse communicated"; the definition of "positive communication" and "reverse communication" is only a schematic explanation given by the present patent for clear expression, and does not specifically limit the various embodiments of the present invention. In some cases, "positive communication" can also correspond to "piston in retraction", and "reverse communication" can also correspond to "piston in extension". The "positive communication" and "reverse communication" of other components, such as the rotary hydraulic motor 420, the track telescopic hydraulic motor 430 and the material lifting hydraulic motor 440, can be analogized.

[0040] When the operator pulls the manual reversing valve assembly 300 to the first state or the second state (such as pushing the valve rod), high-pressure oil directly drives the actuator (such as the variable amplitude oil cylinder 410 extending or retracting), and the oil flows back to the tank 200 through the oil return port of the manual reversing valve assembly 300. At this time, the bridge port C oil circuit is closed, and the electric control reversing valve assembly 500 is in a failure state due to no oil input.

[0041] When the manual reversing valve assembly 300 is in the third state, the oil enters the electric control reversing valve assembly 500 through the bridge port C of the manual reversing valve assembly 300. At this time, the opening and closing state of the electric control reversing valve assembly 500 is controlled by electric signal. If the electromagnetic valve is powered, the oil flows to the actuator (such as driving the hydraulic motor to rotate) through the electric control reversing valve assembly 500; if the electromagnetic valve is not powered, the oil flows back to the tank 200 through the electric control reversing valve assembly 500.

[0042] If the manual reversing valve assembly 300 is operated (switched to the first or second state) at this time, the bridge port C oil circuit is immediately cut off, the oil supply of the electric control reversing valve assembly 500 is interrupted, and the electric control operation is forced to terminate.

[0043] Reference Figure 1 to Figure 4It can be understood that the hydraulic control system provided by the embodiment of the present application establishes a physical exclusion mechanism of the operation channel at the hydraulic level through the three-state oil way design of the manual reversing valve assembly 300. Specifically, when the manual operation is activated (the first or second state), the over-bridge port oil way between the manual reversing valve assembly 300 and the electric control reversing valve assembly 500 is forcibly closed, thereby cutting off the pressure oil supply of the electric control reversing valve assembly 500 from the source, and completely avoiding the possibility that the manual and electric control systems simultaneously supply oil to the executing element.

[0044] Compared with the parallel valve group scheme in the background art which relies on the judgment of the operator, in the hydraulic control system provided by the embodiment of the present application, the operation priority control is automatically realized through the mechanical structure. In the electric control operation process, if the manual operation is started, the hydraulic control system will immediately switch to the manual mode and interrupt the electric control oil way, forming a fail-safe mechanism. Taking the tractor ladder truck as an example, the equipment can be taken over in an emergency through manual operation when the electric control reversing valve assembly 500 fails, which can effectively avoid the out-of-control and dangerous situation caused by the failure of the electric control reversing valve assembly 500, and can effectively protect the personal safety of the operator and improve the safety of the on-site operation.

[0045] Continuing to refer to Figure 3 and Figure 4 In the optional embodiment of the present application, the electric control reversing valve assembly 500 includes a first electric control reversing valve 510 and a proportional reversing valve 520. The first electric control reversing valve 510 is connected between the manual reversing valve assembly 300 and the executing assembly 400, and is used to connect or disconnect the connection between the electric control reversing valve assembly 500 and the executing assembly 400. The first electric control reversing valve 510 can be selected from existing components such as a three-position four-way electromagnetic reversing valve.

[0046] The proportional reversing valve 520 is connected between the manual reversing valve assembly 300 and the oil tank 200, and the upstream of the proportional reversing valve 520 and the upstream of the first electric control reversing valve 510 are connected in communication. The proportional reversing valve 520 controls the flow through the first electric control reversing valve 510 by adjusting the opening degree of the valve port. The proportional reversing valve 520 can be selected from an electro-hydraulic proportional valve or a proportional solenoid valve.

[0047] In use, when the manual reversing valve assembly 300 is in the third state, high-pressure oil enters the electric control reversing valve assembly 500 through the bridge port C. When the first electric control reversing valve 510 is powered (such as a controller signal), the oil way is connected (such as P5-B5 is connected, T5-A5 is connected), allowing the oil to drive the executing element. If the first electric control reversing valve 510 is powered off, the oil way is cut off (such as P5-B5 is disconnected, T5-A5 is disconnected), and the electric control operation is immediately terminated.

[0048] In the case that the first electric control reversing valve 510 is powered (such as a controller signal), Figure 4As shown in the figure, when the proportional reversing valve 520 is input with a small current, the Pc-Tc oil passage is fully opened, most of the oil directly returns to the oil tank 200 through the proportional reversing valve 520, and a small amount of oil enters the first electric control reversing valve 510, and the execution assembly 400 operates at low speed (for example, the material lifting hydraulic motor 440 rotates at low speed). When the proportional reversing valve 520 is input with an increased current, the throttling effect of the Pc-Tc oil passage is enhanced, the oil flow to the first electric control reversing valve 510 is increased, and the execution assembly 400 accelerates. Figure 3 As shown in the figure, the hydraulic oil directly returns to the oil tank 200 through the proportional reversing valve 520.

[0049] In the above process, when the manual reversing valve assembly 300 is manually operated, the bridge port C oil passage is forcibly cut off, the proportional reversing valve 520 and the first electric control reversing valve 510 are simultaneously de-energized, and the electric control function is disabled.

[0050] Referring to Figure 3 and Figure 4 It can be understood that, in the hydraulic control system provided by the embodiment of the present application, the throttling effect of the proportional reversing valve 520 can provide stepless flow regulation capability, overcoming the limitation of the traditional on-off valve that is only fully open or fully closed. Taking a towed aerial ladder as an example, the material lifting speed can be dynamically optimized according to the load (for example, low speed to prevent shaking under heavy load, and high speed to improve efficiency under light load). Secondly, the first electric control reversing valve 510 as an independent switch provides the electric control circuit with rapid start-stop capability (for example, immediately terminating the action in case of emergency power failure), and is decoupled from the speed regulation function of the proportional valve, effectively reducing the system complexity. In addition, both valves are subject to the priority of manual operation. When manual intervention occurs, the physical cut-off of the bridge port oil passage completely disables the electric control reversing valve assembly 500, effectively avoiding the power conflict (for example, abnormal shaking of the oil cylinder or over-speed of the motor) caused by the parallel oil supply of the double valves in the background technology.

[0051] In an optional embodiment of the present application, the electric control reversing valve assembly 500 further comprises a valve body provided with a mounting portion (for example, a standard plug-in hole), and the first electric control reversing valve 510 is arranged in the corresponding mounting portion in a detachable plug-in manner. Optionally, the proportional reversing valve 520 can also be arranged in the corresponding mounting portion in a detachable plug-in manner, and the Pc port and the Tc port thereof are respectively connected to the internal oil passage of the valve body. The plug-in manner can be selected from a threaded screw-in or a buckle type structure, which can be adaptively selected according to the actual situation.

[0052] During the maintenance replacement process, the hydraulic control system is closed and depressurized, the external wires and oil pipe joints of the proportional directional valve 520 are disassembled, the locking nut (or the buckle is pressed) of the first electric control directional valve 510 is unscrewed, the old valve core is pulled out from the installation part, the new valve core is inserted along the installation part, and it is ensured that the sealing ring is embedded in the valve body groove; the locking nut is locked again (or the buckle is reset), the pipeline is connected, and the replacement is completed; the valve body is used as an oil way integrated platform, the inlet / outlet of the plug-in valve (the first electric control directional valve 510 or the proportional directional valve 520) is automatically aligned with the internal flow channel through the installation part, and after power-on, the proportional directional valve 520 still adjusts the flow based on the principle described above.

[0053] It can be understood that when the proportional directional valve 520 or the first electric control directional valve 510 fails, the entire valve group does not need to be replaced, only the single plug-in valve needs to be disassembled and maintained, which can effectively shorten the downtime and reduce the operation and maintenance cost; compared with the traditional welded or bolted integrated valve group, the plug-in structure avoids the complicated process of re-connecting dozens of oil pipes when disassembling the valve block, which can reduce the risk of misinstallation; secondly, the valve body is used as a universal platform compatible with different specifications of plug-in valves, for example, the proportional valve can be replaced by different flow rate types, which expands the adaptive flexibility of the hydraulic control system.

[0054] Referring to Figure 3 and Figure 4 , in the optional embodiment of the application, the manual directional valve assembly 300 includes a plurality of six-way valves 310 (for example, four as shown in Figure 3 , each six-way valve 310 is provided with two functional positions, an execution position: connecting the power assembly 100 and the corresponding execution assembly 400 (such as the rod cavity and the rodless cavity of the oil cylinder), realizing manual control; and an electric conversion position (i.e., the third state): disconnecting the connection with the execution assembly 400, and instead guiding the oil to the series electric control passage.

[0055] Among them, the electric conversion positions of all six-way valves 310 are connected in series (such as the cascade oil way where the cross port C in Figure 3 is located), forming the main electric control oil way, when all six-way valves 310 are in the electric conversion position, the oil flows through valve 1→valve 2→valve 3→valve 4→the electric control directional valve assembly 500 in turn as shown in Figure 2 ; when any six-way valve 310 is switched to the execution position, the electric conversion position of the valve can cut off the electric control oil way of the segment where the valve is located (such as the valve core displacement sealing).

[0056] In the implementation process, in the initial state, all six-way valves 310 are in the handover position, and the oil is transmitted to the electrically controlled reversing valve assembly 500 through the series structure for electrically controlled operation; if the six-way valve 310 is operated to the execution position (such as pushing the valve rod), the six-way valve 310 cuts off the oil circuit in series with itself, and the oil is redirected to drive the corresponding execution assembly 400; due to the existence of the cascade oil circuit, the series outlets of valve 2, valve 3 and valve 4 downstream of valve 1 are simultaneously cut off, and the global electric control function is immediately terminated.

[0057] It can be understood that in the hydraulic control system provided by the embodiment of the present application, each six-way valve 310 controls a single execution component, which can avoid mutual interference of multiple execution operations; secondly, when any six-way valve 310 is switched to the execution position, the electric control oil circuit in the section where the six-way valve 310 is located is physically cut off, and due to the series connection of the oil circuit, the entire downstream electrically controlled reversing valve assembly 500 loses pressure. Compared with the parallel valve group that is not associated, the hydraulic control system provided by the embodiment of the present application can ensure that any manual operation forces the global electric control to be disabled, thereby avoiding the risk of multiple valves supplying oil at the same time; in addition, when a single six-way valve 310 fails (such as valve core jamming), it can be isolated for repair without affecting the functions of other valves, thereby solving the problem of high repair cost of the integrated design of the traditional multi-way valve.

[0058] Continuing to refer to Figure 1 to Figure 4 In an optional embodiment of the present application, the execution assembly 400 includes a plurality of execution components, which can be hydraulic cylinders or hydraulic motors, or other components that can be driven by hydraulic oil.

[0059] The number of execution components is the same as the number of the aforementioned six-way valves 310, and each execution component is manually controlled by a corresponding independent six-way valve 310, that is, each execution component and the corresponding six-way valve 310 form a separate pair, and at least one pair of execution components and six-way valves 310 in the plurality of execution components and the plurality of six-way valves 310 are connected to the electrically controlled reversing valve assembly 500 through the hydraulic oil circuit. As Figure 1 to Figure 4 As shown in FIG. 3, from left to right, in the hydraulic oil circuit of the six-way valve 310 and the execution component of the third group, the outlet of the execution component is connected to the six-way valve 310 and the electrically controlled reversing valve assembly 500 at the same time, and the inlet of the execution component is also connected to the six-way valve 310 and the electrically controlled reversing valve assembly 500 at the same time.

[0060] For example, in an optional embodiment, the execution components include the luffing cylinder 410, the slewing hydraulic motor 420, the track extension hydraulic motor 430, and the material lifting hydraulic motor 440. Among them, the material lifting hydraulic motor 440 is connected to the electric control reversing valve assembly 500 through the corresponding six-way valve 310, realizing remote electric control operation of material lifting; while the luffing cylinder 410, the track extension hydraulic motor 430, and the slewing hydraulic motor 420 are only manually controlled through the corresponding six-way valve 310. In another optional embodiment, the track extension hydraulic motor 430 can also be connected to the electric control reversing valve assembly 500 to adapt to the electric control requirement of the extension of the ladder arm 610. Specifically, the design can be adaptively selected according to actual conditions.

[0061] In use, when the operator pushes the valve rod of a certain six-way valve 310, the hydraulic oil directly flows to the corresponding execution component to drive its action. For example, after pushing the valve rod of the six-way valve 310 corresponding to the luffing cylinder 410, the hydraulic oil enters the rodless cavity of the luffing cylinder 410 to push the piston rod to extend to adjust the track angle; at this time, the bridge port channel of the six-way valve 310 is closed, and the electric control oil circuit is cut off.

[0062] When not manually operated, the hydraulic oil flows to the electric control reversing valve assembly 500 through the bridge port channel of the six-way valve 310. At this time, the electric control reversing valve assembly 500 can be started through an electric control signal (such as a handle instruction) to drive the execution component (such as the material lifting hydraulic motor 440) connected thereto. The material lifting hydraulic motor 440 realizes stepless speed change under the adjustment of the proportional reversing valve 520, so that the material is lifted at different speeds. If any six-way valve 310 is manually operated during electric control operation, the bridge port channel is immediately closed, the electric control oil circuit is interrupted, and manual operation takes priority over system control to ensure operation safety.

[0063] It can be understood that, in the hydraulic control system provided by the embodiment of the present application, through the one-to-one corresponding connection of the execution components and the six-way valves 310, independent control of each action is realized, and mutual interference when multiple actions are performed in parallel is avoided. At the same time, the high-frequency operation component (such as material lifting) supports remote speed regulation function through the electric control reversing valve assembly 500, effectively improving operation efficiency and convenience; while the low-frequency operation component (such as track luffing) adopts manual control with low cost, reducing the overall cost of the system.

[0064] Compared with the traditional proportional multi-way valve scheme, in the hydraulic control system provided by the embodiment of the present application, the priority mechanism of manual operation can be immediately switched to manual mode in the event of electric control failure, which can effectively avoid the risk of loss of control and improve work safety.

[0065] Figure 5 is a structural schematic view of the traction ladder truck provided by the embodiment of the present application.

[0066] Referring toFigure 1 and Figure 5 The embodiment of the present application provides a traction ladder truck, which comprises a vehicle body 600 and the hydraulic control system in any of the foregoing embodiments; and the difference from the foregoing embodiments is that, in the embodiment, the execution assembly 400 is directly implemented to the structure of the traction ladder truck itself, such as the luffing oil cylinder 410, the slewing hydraulic motor 420, the track telescopic hydraulic motor 430 and the material lifting hydraulic motor 440.

[0067] Therefore, in the embodiment, the execution assembly 400 comprises the luffing oil cylinder 410, the slewing hydraulic motor 420, the track telescopic hydraulic motor 430 and the material lifting hydraulic motor 440. The luffing oil cylinder 410 is connected with the manual reversing valve assembly 300, and the angle between the ladder arm 610 and the ground is adjusted through the telescopic adjustment of the piston rod, for example, the valve rod in the manual reversing valve assembly 300 is manually operated in the deployment stage, so that the ladder arm 610 is lifted from the horizontal position to the working angle of 60°.

[0068] The slewing hydraulic motor 420 is connected with the manual reversing valve assembly 300, and the ladder arm 610 is driven to rotate around the slewing center to align the target direction, and the slewing hydraulic motor 420 can adopt a cycloid motor or a gear motor to realize the angle adjustment in the range of ±180°. The track telescopic hydraulic motor 430 is connected with the manual reversing valve assembly 300, and the length of the ladder arm 610 is controlled through the winding or releasing of the steel wire rope, for example, the ladder arm 610 can be extended from 5 meters to 15 meters in the telescopic process.

[0069] The material lifting hydraulic motor 440 is connected with the manual reversing valve assembly 300 and the electric control reversing valve assembly 500, and is used for controlling the lifting of the material platform 620; in specific application, the material lifting hydraulic motor 440 drives the material platform 620 to move along the guide rail of the ladder arm 610 through a winch. It should be noted that the luffing oil cylinder 410 can be replaced by a double-acting hydraulic cylinder, and the slewing hydraulic motor 420 can be adapted to a planetary reduction mechanism to increase the torque, that is, the specific models of the components such as the luffing oil cylinder 410, the slewing hydraulic motor 420, the track telescopic hydraulic motor 430 and the material lifting hydraulic motor 440 are not limited in the embodiment, and can be adaptively selected according to actual conditions.

[0070] In the use process, after the hydraulic control system is started, the power assembly 100 provides high-pressure oil to the manual reversing valve assembly 300, when the valve rod corresponding to the luffing oil cylinder 410 is operated, the hydraulic oil enters the rodless cavity of the oil cylinder to push the piston rod to extend out, and the bridge port channel is synchronously closed to cut off the electric control oil path, so that the angle of the ladder arm 610 is increased; when the valve rod is reversely operated, the hydraulic oil enters the rod cavity to reduce the angle of the ladder arm 610.

[0071] When operating the valve stem of the slewing hydraulic motor 420, the hydraulic oil drives the motor to rotate, thereby driving the ladder arm 610 to rotate horizontally, for example, from the north direction to the east direction by 90°. When the track telescopic hydraulic motor 430 is working, the hydraulic oil drives the winding drum to wind or unwind the wire rope, thereby extending or retracting the ladder arm 610 in sections.

[0072] The material lifting hydraulic motor 440 directly controls the lifting speed of the material platform 620 by the valve stem in the manual mode; in the electric control mode, the operator sends signals through the remote control handle, and the proportional valve adjusts the flow to realize stepless speed change of the material platform 620, for example, the material platform 620 is lifted at a high speed of 0.5 m / s under light load, and is automatically switched to low-speed operation of 0.2 m / s under heavy load. If any valve stem is manually pushed during electric control operation, the bridge passage is immediately closed, the electric control oil way is interrupted, and the system is forced to switch to the manual mode.

[0073] It can be understood that, in the traction ladder truck provided by the embodiment of the present application, the hydraulic control system is applied to the traction ladder truck, low-cost manual control of deployment actions (amplitude change, slewing, telescoping) and automatic electric control collaborative operation of high-frequency material lifting actions are realized. Compared with the conventional ladder truck using a proportional multi-way valve, the manual reversing valve assembly 300 is used as the main valve in the traction ladder truck provided by the embodiment of the present application, thereby effectively reducing the system cost, and the independent electric control reversing valve assembly 500 is used to provide electric control stepless speed regulation function for material lifting, thereby improving the operation efficiency under the premise of ensuring safety; in addition, the amplitude change, slewing and telescoping actions belong to deployment work before construction, compared with electric control operation, the direct operation of the operator on the corresponding valve of the equipment, the feedback of the equipment can be more intuitively perceived, and the possibility of equipment overturning in the deployment process caused by electrical failure is avoided.

[0074] The double-path control design of the material lifting hydraulic motor 440 solves the problem of low operation efficiency of the pure manual scheme, and the priority mechanism of manual operation can immediately take over the equipment in the event of electric control failure, thereby avoiding the risk of out-of-control falling of the material platform 620, and exhibiting higher reliability and practicality in the harsh environment of dust and temperature difference in the construction site.

[0075] In the optional embodiment of the present application, the first position detection member, the second position detection member, the third position detection member and the fourth position detection member are sequentially and spaced apart in the length direction of the ladder arm 610 of the traction ladder truck. The first position detection member is located at the bottom end of the ladder arm 610 and is used to determine the initial position of the material platform 620 (for example, the position where the material platform 620 is completely lowered to the ground); the fourth position detection member is located at the top end of the ladder arm 610 and is used to determine the preset target position of the material platform 620 (for example, the highest working point that the material platform 620 needs to reach).

[0076] The second position detection member is located between the first position detection member and the fourth position detection member, and is used for marking an acceleration position when the material platform 620 rises or a deceleration position when the material platform 620 falls; and the third position detection member is located between the second position detection member and the fourth position detection member, and is used for marking a deceleration position when the material platform 620 rises or an acceleration position when the material platform 620 falls.

[0077] The first position detection member, the second position detection member, the third position detection member and the fourth position detection member can be non-contact detection devices such as proximity switches, photoelectric sensors or magnetic sensors, and can also be Hall sensors or infrared sensors. The electrically controlled reversing valve assembly 500 is electrically connected with the first position detection member, the second position detection member, the third position detection member and the fourth position detection member through wires, receives trigger signals of the first position detection member, the second position detection member, the third position detection member and the fourth position detection member, and controls the running state of the material lifting hydraulic motor 440.

[0078] In another optional embodiment, the types of the first position detection member, the second position detection member, the third position detection member and the fourth position detection member can be replaced with mechanical limit switches or ultrasonic ranging modules, and the installation positions of the first position detection member, the second position detection member, the third position detection member and the fourth position detection member are dynamically adjusted according to the length of the ladder arm 610 (for example, the second position detection member of the 10-meter ladder arm 610 is arranged at a position 3 meters away from the bottom end).

[0079] When the one-key lifting function of the material platform 620 is started by the operator, the electrically controlled reversing valve assembly 500 automatically adjusts the rotating speed of the material lifting hydraulic motor 440 according to the signals of the position detection members, taking the rising of the material platform 620 as an example.

[0080] Initial position triggering: the material platform 620 starts from the first position detection member (the bottom end) and runs at a low speed (for example, 0.1 m / s).

[0081] Acceleration position triggering: when the platform reaches the second position detection member (a height of 5 meters), the proportional reversing valve 520 reduces the flow, and the rotating speed is increased to full speed (for example, 0.5 m / s).

[0082] Deceleration position triggering: when the platform reaches the third position detection member (a height of 12 meters), the proportional reversing valve 520 gradually increases the flow, and the rotating speed is reduced to a low speed (for example, 0.1 m / s). Target position triggering: when the platform reaches the fourth position detection member (a height of 15 meters), the first electrically controlled reversing valve 510 cuts off the oil path, and the platform stops running.

[0083] In the descending process, the position detection members function reversely: the third position detection member triggers acceleration (high-speed descending), and the second position detection member triggers deceleration (low-speed descending). If other valve rods (for example, the amplitude cylinder 410) are manually operated, the overpass passage is immediately closed, the electrically controlled oil path is interrupted, and the one-key lifting function is forcibly terminated.

[0084] It can be understood that, in the traction ladder truck provided by the embodiment of the present application, through the cooperative action of the four position detection pieces on the ladder arm 610, automatic speed control in the whole lifting process of the material platform 620 is realized. Compared with the traditional scheme of relying on manual experience to adjust the speed, the embodiment of the present application improves the operation stability and safety by improving the operation efficiency in the acceleration section and avoiding material shaking or equipment impact caused by sudden stop in the deceleration section, which greatly reduces the operation complexity in the high-rise building construction scene and optimizes the energy utilization rate.

[0085] With reference to the foregoing description Figure 1 In the optional embodiment of the present application, the hydraulic oil circuit in which the track telescopic hydraulic motor 430 is located further comprises a check valve 431 and a balance valve 432. The oil inlet of the check valve 431 is connected to the second end (such as the motor oil return side) of the track telescopic hydraulic motor 430, and the oil outlet is connected to the first end (such as the motor oil inlet side) of the motor. The pressure oil port of the balance valve 432 is connected to the manual reversing valve assembly 300, the oil return port of the balance valve 432 is connected to the first end of the track telescopic hydraulic motor 430, and the oil outlet of the check valve 431 is connected to the oil return port of the balance valve 432. The pilot control port of the balance valve 432 is connected to the second end of the track telescopic hydraulic motor 430.

[0086] In specific implementation, the check valve 431 can adopt a steel ball type or a cone valve type structure, and its function is to allow hydraulic oil to flow from the second end of the motor to the first end in one direction and prevent reverse flow. The balance valve 432 is a hydraulic control valve, which internally integrates the check valve 431 and a throttle valve core, for example, an FD type balance valve or a plug-in balance valve module. Alternatively, the check valve 431 can be replaced by a hydraulic control check valve, and its opening and closing are controlled through an external oil circuit; the balance valve 432 can also adopt a split type design (such as an independent check valve + overflow valve combination) to adapt to different installation space requirements.

[0087] Ladder arm 610 extension process: after the valve rod of the manual reversing valve assembly 300 is pushed, high-pressure oil enters the first end of the track telescopic hydraulic motor 430 through the manual reversing valve assembly 300 and the pressure oil port of the balance valve 432, and drives the track telescopic hydraulic motor 430 to rotate (for example, the steel wire rope is reeled to make the ladder arm 610 lengthen). At this time, the low-pressure oil at the second end of the track telescopic hydraulic motor 430 flows back to the oil tank 200 through the manual reversing valve assembly 300, forming a circulating oil circuit.

[0088] The ladder arm 610 retraction process: when the valve rod of the manual reversing valve assembly 300 is operated in reverse, high-pressure oil enters the second end of the track telescopic hydraulic motor 430 through the manual reversing valve assembly 300, and at the same time, high-pressure oil flows to the side where the first end of the track telescopic hydraulic motor 430 is located through the one-way valve 431. In other words, in this process, the track telescopic hydraulic motor 430 and the one-way valve 431 are in a parallel structure. Due to the presence of the one-way valve 431, the hydraulic oil pressures at the first end and the second end of the track telescopic hydraulic motor 430 are in a balanced state, and the rotor of the track telescopic hydraulic motor 430 is in a floating state. Under the action of its own weight, each arm segment of the ladder arm 610 gradually descends and retracts.

[0089] In this process, high-pressure oil enters the balance valve 432 from the pilot control port of the balance valve 432, pushes the valve core of the balance valve 432, and adjusts the opening degree of the oil return port to provide a preset back pressure under the action of high-pressure oil, so that the ladder arm 610 descends and retracts at a predetermined speed based on the preset back pressure, thereby preventing stalling and falling during retraction. Wherein, if the load of the ladder arm 610 changes suddenly (such as being stuck), the balance valve 432 limits the system pressure through the internal overflow function to protect the hydraulic elements.

[0090] It can be understood that in the traction ladder truck provided by the embodiment of the present application, through the cooperative action of the one-way valve 431 and the balance valve 432, the problem of stalling or impact caused by self-weight during the extension and retraction of the ladder arm 610 is solved. The pilot control mechanism of the balance valve 432 can dynamically adjust the oil return resistance according to the load to ensure that the ladder arm 610 descends and retracts at a uniform speed, and structural vibration or steel wire rope loosening caused by sudden stopping and starting can be avoided; the one-way valve 431 optimizes the oil circuit circulation efficiency and reduces energy loss.

[0091] In the existing traction ladder truck, a material lifting hydraulic motor 440 and a structure in which the material lifting hydraulic motor 440 cooperates are provided. Specifically, the hydraulic circuit in which the material lifting hydraulic motor 440 is located is also provided with a corresponding one-way valve and balance valve. The setting mode of the one-way valve and the balance valve in this circuit is the same as that in the track telescopic hydraulic motor 430 circuit, and the action principle is similar. For details, please refer to the description of the one-way valve 431 and the balance valve 432 in the track telescopic hydraulic motor 430 circuit in the foregoing.

[0092] Further, in order to have a synergistic function, the first end of the material lifting hydraulic motor 440 and the second end of the track telescopic hydraulic motor 430 are connected through a synergistic pipeline, and the second end of the material lifting hydraulic motor 440 and the first end of the track telescopic hydraulic motor 430 are connected through a synergistic pipeline; two check valves are additionally arranged in the system, and the two check valves are arranged on the synergistic pipeline. The oil inlet of the two check valves is towards the track telescopic hydraulic motor 430, and the oil outlet of the two check valves 431 is towards the material lifting hydraulic motor 440, that is, the two check valves 431 allow the hydraulic oil in the circuit where the track telescopic hydraulic motor 430 is located to enter the circuit where the material lifting hydraulic motor 440 is located, and prevent the hydraulic oil in the circuit where the material lifting hydraulic motor 440 is located from entering the circuit where the track telescopic hydraulic motor 430 is located.

[0093] Accordingly, in the process of extending the ladder arm 610, the material platform 620 will slowly fall, so that in the process of extending the ladder arm 610, the material platform 620 will not affect the extension action due to rising to a high place with the ladder arm 610; in the process of falling of the ladder arm 610, the material platform 620 slowly rises, so that in the process of collecting the ladder arm 610, the material platform 620 will not cause the winch to be tangled due to falling to the ground with the ladder arm 610.

[0094] However, this synergistic structure has a defect. In the process of use, due to the inconsistency of the actual angle of the ladder arm 610, for example, it may be 30°, 50° or 80°, or the viscosity of the hydraulic oil changes, and other various influencing factors exist, which causes the movement speed of the ladder arm 610 and the movement speed of the material platform 620 to be inconsistent. For example, in the process of rising, in the ideal state, the ladder arm 610 should rise and the material platform 620 should fall, so that the material platform 620 is relatively static in space position, but the existence of the above factors may cause the speed of the material platform 620 to be too fast or too slow, breaking the original state of the material platform 620 being relatively static; for example, in the process of falling, in the ideal state, the ladder arm 610 should fall and the material platform 620 should rise, so that the material platform 620 is relatively static in space position, but the existence of the above factors may cause the speed of the material platform 620 to be too fast or too slow, breaking the original state of the material platform 620 being relatively static.

[0095] The above-mentioned inconsistency of the speed of the material platform 620 and the ladder arm 610 often exists, so generally in the process of use, the balance valve 432 in the circuit where the track telescopic hydraulic motor 430 is located is actively adjusted, for example, the pre-set pressure in the balance valve 432 is changed or reduced, so that the rising or falling speed of the ladder arm 610 is changed.

[0096] After the above-mentioned regulation of the balance valve 432 in the circuit where the track telescopic hydraulic motor 430 is located, the change will often cause the preset pressure of the balance valve 432 to be different from the circuit pressure required when the ladder arm 610 descends by its own weight. In other words, the adjusted preset pressure is different from the initial preset pressure, which will cause the track telescopic hydraulic motor 430 to continue to reverse after the ladder arm 610 falls to the bottom, thereby causing the winch rope to be tangled, or the track telescopic hydraulic motor 430 may start to rotate forward.

[0097] To address the issue of the balancing valve 432 in the circuit of the track telescopic hydraulic motor 430, in an optional embodiment of the present invention, the electrically controlled reversing valve assembly 500 further includes a second electrically controlled reversing valve 530 and a third electrically controlled reversing valve 540. The second electrically controlled reversing valve 530 has one end connected to the oil tank 200 and the other end connected to the pressure oil port of the balancing valve 432. The third electrically controlled reversing valve 540 has one end connected to the oil tank 200 and the other end connected to the oil inlet of the check valve 431 (i.e., the oil circuit corresponding to the second end of the track telescopic hydraulic motor 430). The second and third electrically controlled reversing valves 530 and 540 can be two-position, two-way solenoid valves or proportional solenoid valves, with their opening and closing states controlled by electrical signals. It should be noted that the second and third electrically controlled reversing valves 530 and 540 can also be plug-in valves, integrated within the valve block to save space.

[0098] During the normal extension of the ladder arm 610, when the manual reversing valve assembly 300 is operated to drive the track telescopic hydraulic motor 430, high-pressure hydraulic oil flows from the first end to the second end of the track telescopic hydraulic motor 430. At this time, the second electrically controlled reversing valve 530 and the third electrically controlled reversing valve 540 are in a normally closed state and do not affect the operation of the system.

[0099] When the ladder arm 610 touches the top, the second electrically controlled reversing valve 530 opens, releasing the high-pressure oil on the pressure oil port side of the balancing valve 432 (the side where the first end of the track telescopic hydraulic motor 430 is located), so that the high-pressure oil no longer passes through the balancing valve 432 and enters the track telescopic hydraulic motor 430. In this way, the track telescopic hydraulic motor 430 will not continue to rotate, thereby avoiding the problem of the winch wire rope being broken due to continued tightening.

[0100] During the normal retraction of the ladder arm 610, when the manual reversing valve assembly 300 is operated to drive the track telescopic hydraulic motor 430, high-pressure hydraulic oil flows from the manual reversing valve assembly 300 to the large one-way valve 431, and then returns to the return oil port of the manual reversing valve assembly 300 through the one-way valve 431. During this process, the rotor of the track telescopic hydraulic motor 430 is in a floating state, and the ladder arm 610 descends under the influence of its own weight. The balancing valve 432 controls the descending speed of the ladder arm 610. At this time, the second electrically controlled reversing valve 530 and the third electrically controlled reversing valve 540 are in a normally closed state, which does not affect the operation of the system.

[0101] After the ladder arm 610 touches the bottom, the third electric control reversing valve 540 is opened, the pressure on the oil inlet side of the drain one-way valve 431 is released, so that the high-pressure oil originally entering the one-way valve 431 is directly discharged to the oil tank 200 through the third electric control reversing valve 540, and no longer passes through the return oil pipeline of the one-way valve 431, the balance valve 432 and the manual reversing valve assembly 300, and no hydraulic oil passes through the track telescopic hydraulic motor 430.

[0102] It can be understood that, in the traction type aerial ladder vehicle provided by the embodiment of the present application, through the pressure relief effect of the second electric control reversing valve 530 and the third electric control reversing valve 540, the out-of-control problem caused by pressure mismatch when the ladder arm 610 touches the top or the bottom is solved, the key node pressure is actively released at the moment when the ladder arm 610 touches the top or the bottom, the hydraulic motor is locked, and the risks of wire rope collapse, rope disorder or abnormal movement are avoided.

[0103] In an optional embodiment of the present application, upper and lower limit position members are additionally arranged on the traction type aerial ladder vehicle, the upper limit position member (such as a mechanical limit switch or a proximity sensor) is fixed near the limit position of the fully extended ladder arm 610, and the signal output end thereof is electrically connected with the control circuit of the second electric control reversing valve 530.

[0104] When the ladder arm 610 is extended to the limit position, the upper limit position member is triggered (such as a block pressing switch or a sensor sensing a metal mark), sends a guide signal to the second electric control reversing valve 530, and makes the second electric control reversing valve 530 connect the oil circuit of the manual reversing valve assembly 300 and the oil tank 200.

[0105] Similarly, the lower limit position member is installed at the limit position of the fully retracted ladder arm 610, the signal output end thereof is electrically connected with the control circuit of the third electric control reversing valve 540, and when the ladder arm 610 is retracted to the limit position, the lower limit position member is triggered to control the third electric control reversing valve 540 to connect the oil circuit of the manual reversing valve assembly 300 and the oil tank 200. The upper and lower limit position members can be a Hall sensor, a mechanical lever limit switch or an ultrasonic distance measuring module, which can be adaptively selected according to actual conditions.

[0106] It can be understood that, in the traction type aerial ladder vehicle provided by the embodiment of the present application, through the linkage of the upper and lower limit position members with the second electric control reversing valve 530 and the third electric control reversing valve 540, automatic locking protection of the limit position of the ladder arm 610 is realized. For the pressure mismatch problem (such as rope disorder when touching the bottom) caused by adjusting the balance valve 432, the embodiment of the present application actively releases the key node pressure when the ladder arm 610 reaches the limit position, so that the track telescopic hydraulic motor 430 is locked in response, and the system stability can be maintained without manual intervention.

[0107] It should be noted that the technical solutions in various embodiments of the present application can be combined with each other, but the basis for the combination is that it can be realized by a person of ordinary skill in the art; when the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, that is, it is not within the protection scope of the present application.

[0108] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, a person of ordinary skill in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A hydraulic control system, characterized in that: include: A power assembly (100) for providing hydraulic oil; A manual reversing valve assembly (300) is connected to the downstream of the power assembly (100), and the downstream of the manual reversing valve assembly (300) is connected to the oil tank (200), and the manual reversing valve assembly (300) includes a first state, a second state, and a third state; an actuator assembly (400), connected downstream of the manual reversing valve assembly (300), the actuator assembly (400) being used to convert hydraulic energy into mechanical energy for output; The electrically controlled reversing valve assembly (500) is connected to the oil tank (200); in a first state, the manual reversing valve assembly (300) is in forward communication with the actuator assembly (400), and the manual reversing valve assembly (300) is disconnected from the electrically controlled reversing valve assembly (500); in a second state, the manual reversing valve assembly (300) is in reverse communication with the actuator assembly (400), and the manual reversing valve assembly (300) is disconnected from the electrically controlled reversing valve assembly (500); in a third state, the manual reversing valve assembly (300) is disconnected from the actuator assembly (400), and the manual reversing valve assembly (300) is in communication with the electrically controlled reversing valve assembly (500).

2. The hydraulic control system according to claim 1, characterized in that: The electrically controlled reversing valve assembly (500) comprises: a first electrically controlled reversing valve (510) connected between the manual reversing valve assembly (300) and the actuator assembly (400); A proportional reversing valve (520) is connected between the manual reversing valve assembly (300) and the oil tank (200), and the proportional reversing valve (520) is used to control the flow of hydraulic oil in the first electrically controlled reversing valve (510).

3. The hydraulic control system according to claim 2, characterized in that: The electrically controlled reversing valve assembly (500) further comprises a valve body, wherein the valve body is provided with a mounting portion; The first electrically controlled reversing valve (510) is detachably inserted into the mounting portion, and / or the proportional reversing valve (520) is detachably inserted into the mounting portion.

4. The hydraulic control system according to claim 1, characterized in that: The manual reversing valve assembly (300) comprises a plurality of six-way valves (310), each of the six-way valves (310) being provided with an execution position and a manual switching position, and the execution position of each six-way valve (310) being respectively connected to the execution assembly (400); The manual-electrical switching positions of all the six-way valves (310) are arranged in series, and the manual-electrical switching position of each six-way valve (310) can independently disconnect the communication between the electrically controlled reversing valve assembly (500) and the power assembly (100).

5. The hydraulic control system according to claim 4, characterized in that: The execution assembly (400) includes a plurality of execution components, each of which includes a hydraulic cylinder or a hydraulic motor; The plurality of actuators are connected to the plurality of six-way valves (310) in a one-to-one correspondence, and at least one pair of the plurality of actuators arranged in pairs and the six-way valves (310) is connected to the electrically controlled reversing valve assembly (500) in a corresponding manner.

6. A traction-type aerial ladder truck, characterized in that: Comprising a vehicle body (600) and the hydraulic control system according to any one of claims 1 to 4; Wherein, the execution component (400) includes: A variable-luffing oil cylinder (410) is connected to the manual reversing valve assembly (300), and the variable-luffing oil cylinder (410) is used to control the angle between the ladder arm (610) of the vehicle body (600) and the ground; a rotary hydraulic motor (420) connected to the manual reversing valve assembly (300), the rotary hydraulic motor (420) being used to control the rotation angle of the ladder arm (610) of the vehicle body (600); A track telescopic hydraulic motor (430) is connected to the manual reversing valve assembly (300), and the track telescopic hydraulic motor (430) is used to control the extension and contraction of the ladder arm (610) of the vehicle body (600); A material lifting hydraulic motor (440) is connected to the manual reversing valve assembly (300) and the electrically controlled reversing valve assembly (500). The material lifting hydraulic motor (440) is used to control the rise or fall of the material platform (620) of the vehicle body (600).

7. The towable aerial ladder truck according to claim 6, characterized in that: The ladder arm (610) is provided with a first position detection member, a second position detection member, a third position detection member, and a fourth position detection member in sequence and at intervals along the length direction; the electrically controlled reversing valve assembly (500) is electrically connected to the first position detection member, the second position detection member, the third position detection member, and the fourth position detection member, respectively; The first position detection member is used to determine the initial position of the material platform (620); the second detection member is used to determine the ascending acceleration position or the descending deceleration position of the material platform (620); the third detection member is used to determine the ascending deceleration position or the descending acceleration position of the material platform (620); and the fourth position detection member is used to determine the preset target position of the material platform (620).

8. The towable aerial ladder truck according to claim 6, characterized in that: Also includes: a one-way valve (431), wherein the oil outlet of the one-way valve (431) is connected to the first end of the track telescopic hydraulic motor (430), and the oil inlet of the one-way valve (431) is connected to the second end of the track telescopic hydraulic motor (430); A balancing valve (432), the pressure oil port of the balancing valve (432) is connected to the manual reversing valve assembly (300), the return oil port of the balancing valve (432) is connected to the first end of the track telescopic hydraulic motor (430), and the oil outlet of the one-way valve (431) is connected to the return oil port of the balancing valve (432), and the pilot control port of the balancing valve (432) is connected to the second end of the telescopic hydraulic motor.

9. The towable aerial ladder truck according to claim 8, characterized in that: The electrically controlled reversing valve assembly (500) further comprises: A second electrically controlled reversing valve (530), one end of which is connected to the oil tank (200) and the other end of which is connected to the pressure oil port of the balancing valve (432); A third electrically controlled reversing valve (540) has one end connected to the oil tank (200) and the other end connected to the oil inlet of the one-way valve (431).

10. The towable aerial ladder truck according to claim 9, characterized in that: Also includes: an upper limit member electrically connected to the second electrically controlled reversing valve (530), the upper limit member being used to determine the extension limit position of the ladder arm (610); when the upper limit member is triggered, the second electrically controlled reversing valve (530) is connected to the manual reversing valve assembly (300) and the oil tank (200); A lower limit member is electrically connected to the third electrically controlled reversing valve (540), and the lower limit member is used to determine the shortening limit position of the ladder arm (610). When the lower limit member is triggered, the third electrically controlled reversing valve (540) communicates with the manual reversing valve assembly (300) and the oil tank (200).

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