Constant-flow control valve group, auxiliary arm control module, complete hydraulic system, and crane

Abstract

A constant-flow control valve group, an auxiliary arm control module, a complete hydraulic system, and a crane. The constant-flow control valve group comprises: a cartridge valve; a cartridge reversing valve, comprising a working oil port on one side and a main oil return port and a reversing valve oil inlet selectively connected to the working oil port on the other side, the working oil port being connected to a control oil port of the cartridge valve, and the reversing valve oil inlet being connected to a main oil inlet of the cartridge valve; and a feedback on-off valve, disposed in a working feedback oil path connected between the main oil inlet of the cartridge valve and a main feedback oil port of the constant-flow control valve group. The auxiliary arm control module comprises the constant-flow control valve group and a main reversing valve. The complete hydraulic system comprises the auxiliary arm control module and an auxiliary arm luffing cylinder, and may further comprise a load-sensitive oil pump and a main valve. The present application can achieve the effect of directly connecting an auxiliary arm hydraulic system to an existing complete hydraulic system as a sub-module without altering the original system.

Description

Constant flow control valve group, auxiliary boom control module, whole machine hydraulic system and crane

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202410601652.4, filed May 15, 2024, the contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application belongs to the field of engineering machinery hydraulic technology, and in particular, relates to a constant flow control valve group, an auxiliary boom control module, a whole machine hydraulic system and a crane. BACKGROUND

[0004] The auxiliary boom of a crane is mainly used for increasing the lifting height of the load and expanding the working range. During the working process, the working amplitude of the auxiliary boom needs to be frequently changed to adapt to different working condition requirements. There are two ways to change the amplitude of the auxiliary boom, i.e., the mechanical pull plate amplitude changing and the hydraulic cylinder amplitude changing. The mechanical pull plate amplitude changing has more components and a more complex mechanism, and more importantly, the amplitude changing action is not flexible and the reliability is poor. Directly controlling the amplitude of the auxiliary boom by the cylinder is simple, efficient and flexible, and is convenient for realizing automation and intelligentization, so it is applied more and more widely.

[0005] When the cylinder amplitude changing way is adopted, the extension and retraction of the cylinder piston rod of the auxiliary boom amplitude cylinder is used to control the lifting and lowering of the auxiliary boom. Generally, the auxiliary boom amplitude system is supplied with oil by a separately designed constant delivery pump, and the oil is supplied to the cylinder through a hose reel. A main reversing valve is used to control the extension and retraction of the cylinder piston rod. The locking of the amplitude cylinder is usually completed by a bidirectional hydraulic lock. The main reversing valve and the constant delivery pump are unloaded when the amplitude cylinder is not in action. In this conventional auxiliary boom amplitude system, an independent oil pump must be provided for oil supply. Moreover, due to the high pressure requirement, a plunger pump must be newly added, a power take-off port must be added, or a pump bypass port must be added. At the same time, because the plunger pump has a large volume and occupies a large space, it easily affects the overall arrangement of the whole machine. In addition, the system response is poor. After the amplitude changing instruction is issued, the hydraulic oil is sent out from the oil source, passes through dozens of turns of the hose, reaches the cylinder, and then builds pressure to execute the action. The system response time is very long. SUMMARY

[0006] The purpose of the present application is to provide a constant flow control valve group, an auxiliary boom control module, a whole machine hydraulic system and a crane, so as to realize the simplification of the auxiliary boom hydraulic system and the quick access of the auxiliary boom hydraulic system to the whole machine hydraulic system.

[0007] To achieve the above-mentioned purpose, the first aspect of the present application provides a constant flow control valve group, comprising:

[0008] A cartridge valve;

[0009] The plug-in directional valve comprises a working oil port on one side and a main return oil port and a directional valve inlet port selectively connected with the working oil port on the other side, the working oil port is connected with a control oil port of the plug-in valve, and the directional valve inlet port is connected with a main inlet port of the plug-in valve;

[0010] The feedback switch valve is arranged in a working feedback oil circuit connected between the main inlet port of the plug-in valve and a main feedback oil port of the constant flow control valve group.

[0011] In some embodiments, the main feedback oil port, the main inlet port and the main return oil port of the constant flow control valve group are respectively connected with pump quick-change connectors for connecting to a hydraulic pump oil circuit.

[0012] In some embodiments, an inlet bypass oil circuit is connected between the directional valve inlet port and the main inlet port of the plug-in valve, and a first one-way valve is arranged in the inlet bypass oil circuit, the first one-way valve is arranged to allow hydraulic oil to flow from the main inlet port to the directional valve inlet port and to be reversely cut off.

[0013] In some embodiments, the main feedback oil port is connected with a pressure sensor and an electric proportional overflow valve; and / or, the working feedback oil circuit is further provided with a feedback damper in series with the feedback switch valve; and / or, the plug-in directional valve and the feedback switch valve are both electromagnetic directional valves.

[0014] In some embodiments, a supplementary connection oil circuit is connected between the directional valve inlet port and a main outlet port of the plug-in valve, and a second one-way valve is arranged in the supplementary connection oil circuit, the second one-way valve is arranged to allow hydraulic oil to flow from the outlet port of the plug-in valve to the directional valve inlet port and to be reversely cut off.

[0015] The second aspect of the present application provides a sub-arm control module, comprising:

[0016] The constant flow control valve group described above; and

[0017] A main directional valve, an inlet port of the main directional valve on one side is connected with the main outlet port of the plug-in valve, a return oil port of the main directional valve on one side is connected with the main return oil port of the constant flow control valve group, and a working oil port on the other side of the main directional valve is used for connecting a control sub-arm luffing oil cylinder.

[0018] In some embodiments, the sub-arm control module comprises:

[0019] An accumulator is hydraulically connected to the inlet port of the main directional valve;

[0020] An accumulator switch valve is used for controlling the opening and closing of an oil circuit between the accumulator and the inlet port of the main directional valve.

[0021] In some embodiments, the working oil port of the main reversing valve comprises a first working oil port for hydraulic connection of the rodless chamber of the auxiliary boom cylinder and a second working oil port for hydraulic connection of the rod chamber of the auxiliary boom cylinder, and the second working oil port is connected with a relief valve.

[0022] In some embodiments, a first rubber hose reel is arranged in the connecting pipeline of the oil inlet port and the oil return port on one side of the main reversing valve, and a second rubber hose reel is arranged in the connecting pipeline of the working oil port on the other side, and the outer end of the second rubber hose reel is provided with a cylinder quick-change joint for connecting the cylinder oil circuit.

[0023] The third aspect of the present application provides a whole-machine hydraulic system, comprising:

[0024] The auxiliary boom control module described above; and

[0025] The auxiliary boom cylinder is connected with the working oil port circuit of the main reversing valve.

[0026] In some embodiments, the auxiliary boom cylinder comprises a balance valve arranged in the working oil circuit of the rodless chamber and used for locking the oil in the rodless chamber, and the balance valve comprises a balance valve core, a control port of the balance valve core is connected to the working oil circuit of the rod chamber through a pilot oil circuit provided with an inlet damping, and is connected to the low-pressure side of the working oil circuit of the rodless chamber through a bypass oil circuit provided with a bypass damping.

[0027] In some embodiments, the whole-machine hydraulic system further comprises:

[0028] A load-sensitive oil pump and a main valve, the load-sensitive oil pump is used for pumping hydraulic oil towards the main inlet of the main valve and the main inlet of the constant flow control valve group respectively;

[0029] A shuttle valve, a first comparison oil port of the shuttle valve is connected to the feedback oil port of the main valve, and a second comparison oil port is connected to the main feedback oil port of the constant flow control valve group, and an oil outlet of the shuttle valve is connected to the pump feedback port of the load-sensitive oil pump.

[0030] The fourth aspect of the present application provides a crane, comprising the whole-machine hydraulic system according to the present application.

[0031] Through the design of the constant flow control valve group and the auxiliary boom control module, the auxiliary boom hydraulic system can be directly connected to the existing whole-machine hydraulic system as a sub-module without changing the original system. Through the combined design of the cartridge valve, the cartridge reversing valve and the feedback switch valve, the main pump provides a constant flow oil source for the auxiliary boom sub-system after being connected to the whole-machine hydraulic system, without the need to add an oil pump, oil source management and related elements and devices, and the cartridge valve has large flow capacity, which can guarantee the flow demand of the auxiliary boom cylinder.

[0032] Other features and advantages of the present embodiments will be set forth in the detailed description which follows, and in part will be apparent from the description. BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings are included to provide a further understanding of the present embodiments and are incorporated in and constitute a part of this specification, illustrate embodiments of the present embodiments and together with the description serve to explain the present embodiments. Other embodiments of the present embodiments will be apparent to those skilled in the art from consideration of the specification and drawings. It is intended that the specification and examples be considered as illustrative only of the present embodiments and not as restricting the present embodiments.

[0034] Fig. 1 is a hydraulic schematic diagram of a constant flow control valve group according to the present embodiments;

[0035] Fig. 2 is a hydraulic schematic diagram of a sub-arm control module according to the present embodiments;

[0036] Fig. 3 is a hydraulic schematic diagram of a complete machine hydraulic system according to the present embodiments;

[0037] Fig. 4 is a hydraulic schematic diagram of a pump unit part of Fig. 3, showing various main connection oil paths of a load sensing pump;

[0038] Fig. 5 shows the hydraulic oil flow direction of the complete machine hydraulic system of Fig. 3 in a state that the sub-arm is not used or the sub-arm hook is not carrying a load;

[0039] Fig. 6 shows the hydraulic oil flow direction of the complete machine hydraulic system of Fig. 3 in a sub-arm luffing preparation state;

[0040] Fig. 7 shows the hydraulic oil flow direction when the accumulator is being charged;

[0041] Fig. 8 shows the hydraulic oil flow direction of the complete machine hydraulic system of Fig. 3 when the sub-arm cylinder is extended;

[0042] Fig. 9 shows the hydraulic oil flow direction of the complete machine hydraulic system of Fig. 3 when the sub-arm luffing action is stopped and the heavy load is being carried;

[0043] Fig. 10 shows the hydraulic oil flow direction of the complete machine hydraulic system of Fig. 3 in a sub-arm luffing stop state.

[0044] Explanation of reference signs 1 sub-arm variable amplitude oil cylinder 2 balance valve 3 oil cylinder quick-change joint 4 second rubber tube reel 5 first rubber tube reel 6 overflow valve 7 main reversing valve 8 accumulator on-off valve 9 accumulator 10 electric proportional overflow valve 11 feedback on-off valve 12 cartridge valve 13 pressure sensor 14 first check valve 15 cartridge reversing valve 16 pump quick-change joint 17 load-sensitive oil pump 18 main valve 19 shuttle valve 14' second check valve 21 balance valve spool 22 inlet damping 23 bypass damping P main oil inlet P0 reversing valve oil inlet T0 main oil return K main feedback oil return A main feedback oil return A1 first working oil port A2 second working oil port DETAILED DESCRIPTION

[0045] The specific embodiments of the present application will be described below in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present application, and are not intended to limit the present application.

[0046] A constant flow control valve group, a sub-arm control module, a complete machine hydraulic system and a crane according to the present application are described below with reference to the accompanying drawings.

[0047] The application first discloses a novel constant flow control valve group, namely a plug-in valve group, which is used for providing a constant flow oil source for a subsystem of a driving auxiliary arm luffing cylinder, and is convenient to be connected to a main pump or a main oil supply oil path of a complete machine hydraulic system, and compared with an auxiliary arm luffing cylinder system in the prior art, the constant flow control valve group does not need to add an oil pump, an oil source management and related elements and devices.

[0048] As shown in FIG. 1, in a specific embodiment, the constant flow control valve group comprises:

[0049] a plug-in valve 12;

[0050] a plug-in reversing valve 15, which comprises a working oil port on one side and a main return oil port T0 and a reversing valve inlet port P0 selectively connected with the working oil port on the other side, the working oil port is connected with a control oil port of the plug-in valve 12, and the reversing valve inlet port P0 is connected with a main inlet port P of the plug-in valve 12;

[0051] a feedback switch valve 11, which is arranged in a working feedback oil path connected between the main inlet port P of the plug-in valve 12 and a main feedback oil port K of the constant flow control valve group.

[0052] As shown in FIG. 3, the load-sensitive oil pump 17 of the complete machine hydraulic system can not only drive a main arm frame and the like through a main valve 18, but also can be divided to the main inlet port P of the constant flow control valve to drive the auxiliary arm luffing cylinder, so that the auxiliary arm luffing cylinder does not need a special driving oil pump and corresponding supporting oil source management and other elements. In the constant flow control valve, the pressure oil enters a side oil port of the plug-in valve 12 through the main inlet port P, when the control oil port is opened, the pressure oil of the side oil port can flow out through a main outlet port A of the plug-in valve 12 and flow to a reversing valve of the auxiliary arm luffing cylinder 1, namely the main reversing valve 7 in FIG. 3.

[0053] In addition, the reversing valve inlet port P0 and the main inlet port P of the plug-in valve 12 are connected with an inlet bypass oil path, the inlet bypass oil path is provided with a first one-way valve 14, and the first one-way valve 14 is arranged to allow hydraulic oil to flow from the main inlet port P to the reversing valve inlet port P0 and to be reversely cut off. In this way, part of the pressure oil can bypass into the plug-in reversing valve 15 through the main inlet port P, so as to enter the control oil port of the plug-in valve 12 to drive the plug-in valve 12 to be opened. Further, the reversing valve inlet port P0 and the main outlet port A of the plug-in valve 12 can be connected with a supplementary connection oil path, the supplementary connection oil path is provided with a second one-way valve 14', and the second one-way valve 14' is arranged to allow hydraulic oil to flow from the outlet port of the plug-in valve 12 to the reversing valve inlet port P0 and to be reversely cut off. In this way, the pressure of the reversing valve inlet port P0 can be ensured to be the greater one of the main inlet port P or the main outlet port A of the plug-in valve 12, so as to reliably close the plug-in valve 12 under a specific control working condition of the plug-in reversing valve 15.

[0054] The constant flow control valve group has a main feedback oil port K for feeding back the pressure of the main oil inlet port P of the plug-in valve 12 to the oil pump, so as to adjust the displacement of the oil pump and the like. The feedback of the oil pressure can be controlled by controlling the feedback switch valve 11. In order to keep the feedback oil pressure stable, a feedback damper in series with the feedback switch valve 11 is arranged in the working feedback oil circuit. The main feedback oil port K can be connected with a pressure sensor 13 and an electric proportional overflow valve 10. The real-time pressure of the system can be measured by the pressure sensor 13, and the pressure value of the main feedback oil port K can be adjusted by adjusting the current value of the proportional solenoid Y5 of the electric proportional overflow valve 10, so as to adjust the flow output and the actual oil supply pressure of the main pump, and form a constant pressure oil source which can be flexibly adjusted.

[0055] The plug-in reversing valve 15 and the feedback switch valve 11 are both electromagnetic reversing valves, which are convenient for the electric control system to perform targeted control according to different working conditions. Of course, it can be understood by those skilled in the art that in other embodiments, the plug-in reversing valve 15 and the feedback switch valve 11 can also be adaptively designed as hydraulic control reversing valves.

[0056] In the embodiment, the main feedback oil port K, the main oil inlet port P and the main return oil port T0 of the constant flow control valve group are respectively connected with pump quick-change connectors 16 for connecting to the hydraulic pump oil circuit, as shown in FIG. 2. In this way, the three groups of quick-change connectors on the three oil circuits can be conveniently connected to the three connecting oil circuits of the variable pump shown in FIG. 4. In other words, the high-pressure, return and feedback oil circuits of the subsystem of the auxiliary arm luffing cylinder 1 can be directly connected to the existing whole machine hydraulic system without changing the original system.

[0057] On the basis of the constant flow control valve group, the application further discloses an auxiliary arm control module. As shown in FIG. 2, the auxiliary arm control module in one specific embodiment comprises:

[0058] The constant flow control valve group and the main reversing valve 7 are connected with each other as follows: the oil inlet port P1 on one side of the main reversing valve 7 is connected with the main oil outlet port A of the plug-in valve 12, the return oil port T1 on one side of the main reversing valve 7 is connected with the main return oil port T0 of the constant flow control valve group, and the working oil port on the other side of the main reversing valve 7 is used for connecting the control auxiliary arm luffing cylinder 1.

[0059] It can be seen that the constant flow control valve group and the main reversing valve 7 can be integrated into an auxiliary arm control module for controlling the auxiliary arm luffing cylinder, and when used, only need to be connected to the hydraulic pump and the auxiliary arm luffing cylinder 1 of the whole machine hydraulic system, which is simple and convenient to operate.

[0060] In the embodiment, the auxiliary arm control module can comprise:

[0061] The accumulator 9 is hydraulically connected to the oil inlet port P1 of the main reversing valve 7;

[0062] The accumulator switch valve 8 is used for controlling the opening and closing of the oil circuit between the accumulator 9 and the oil inlet port P1 of the main reversing valve 7.

[0063] Wherein, through the energy storage switch valve 8, the energy accumulator 9, a high-pressure oil source can be formed, which is kept at the P1 port of the main reversing valve 7, and the pipeline of the main reversing valve 7 and the oil cylinder is short, so that the pressure oil can immediately enter the corresponding oil cylinder cavity to push the piston rod to extend or retract as soon as the solenoid valve is powered on, and the action response is timely and rapid. During the lifting process, the energy accumulator 9 absorbs and eliminates the flow pulsation of the oil pump itself, the flow fluctuation caused by the system load change or other factors, so as to ensure the stable and continuous flow output, and the action is always smooth during the whole lifting process. The energy storage switch valve 8 is arranged in front of the energy accumulator 9, the system pressure is measured by the pressure sensor 13, so as to control the on-off of the energy storage switch valve 8, which not only ensures the stability and reliability of the system oil source, but also can flexibly control the participation degree of the energy accumulator 9 to the system action.

[0064] Referring to FIG. 2, the working oil port of the main reversing valve 7 includes a first working oil port A1 for hydraulically connecting the rodless cavity of the auxiliary arm luffing cylinder 1 and a second working oil port A2 for hydraulically connecting the rod cavity of the auxiliary arm luffing cylinder 1, and the second working oil port A2 is connected with the overflow valve 6.

[0065] The overflow valve 6 in FIG. 2 is connected between the second working oil port A2 of the main reversing valve 7 and the oil return port TO, which can limit the maximum oil pressure entering the rod cavity of the oil cylinder through the second working oil port A2, as shown in FIG. 3. Further, in the luffing process, the constant pressure source and the subsequent pressure dividing liquid bridge can ensure the stable opening port pressure of the balance valve 2, so as to ensure the stability of the balance valve port, which is not affected by the load pressure change, and the existing technology is prone to jitter during the luffing process.

[0066] Wherein, the first rubber hose reel 5 is arranged in the connecting pipeline of the oil inlet port P1 and the oil return port T1 on one side of the main reversing valve 7, and the second rubber hose reel 4 is arranged in the connecting pipeline of the working oil port on the other side, and the outer end of the second rubber hose reel 4 is provided with an oil cylinder quick-change connector 3 for connecting the oil cylinder oil circuit. Through the oil cylinder quick-change connector 3, the auxiliary arm luffing cylinder 1 can be directly and conveniently connected.

[0067] On the basis of the above-mentioned auxiliary arm luffing cylinder 1, the application further discloses a complete machine hydraulic system. As shown in FIG. 3, the complete machine hydraulic system of one specific embodiment comprises:

[0068] The auxiliary arm control module described above; and

[0069] The auxiliary arm luffing cylinder 1 is connected with the working oil port oil circuit of the main reversing valve 7.

[0070] The auxiliary arm control module is connected with the auxiliary arm luffing cylinder 1 through the oil cylinder quick-change connector 3, and is also connected with the load-sensitive oil pump 17 of the main system through the pump quick-change connector 16, so that the subsystem of the auxiliary arm luffing cylinder 1 can be connected to the complete machine hydraulic system.

[0071] To realize the connection with the load sensitive pump 17 of the main system, the whole machine hydraulic system further comprises:

[0072] The load sensitive pump 17 and the main valve 18, the load sensitive pump 17 is used for pumping hydraulic oil to the main valve 18 and the main inlet port P of the constant flow control valve group respectively;

[0073] The shuttle valve 19, the first comparison oil port of the shuttle valve 19 is connected with the feedback oil port of the main valve 18, and the second comparison oil port is connected with the main feedback oil port K of the constant flow control valve group, and the oil outlet port of the shuttle valve 19 is connected with the pump feedback port of the load sensitive pump 17.

[0074] The main valve 18 is usually a multi-way valve, which can be used to control multiple action units or work tools. When the load sensitive pump 17 (also known as the main pump) simultaneously supplies hydraulic oil to the main valve 18 and the auxiliary arm control module, in order to control the pump displacement, it is necessary to compare the pressure of the feedback oil port of the main valve 18 with the pressure of the main feedback oil port K of the auxiliary arm control module through the shuttle valve 19, and the larger one is fed back to the pump feedback port of the variable pump, thereby adjusting the pumped oil volume.

[0075] Wherein, the auxiliary arm luffing oil cylinder 1 comprises a balance valve 2 arranged in a rodless cavity working oil path and used for locking the rodless cavity oil, the balance valve 2 comprises a balance valve core 21, a control port of the balance valve core 21 is connected to a rod cavity working oil path through a pilot oil path provided with an inlet damping 22 and connected to a low pressure side of the rodless cavity working oil path through a bypass oil path provided with a bypass damping 23.

[0076] The balance valve 2 can be integrally arranged on the cylinder barrel of the auxiliary arm luffing oil cylinder 1. By arranging the inlet damping 22 and the bypass damping 23, a pressure division structure can be formed. In the case of constant total pressure (limited by the overflow valve 6), the pressure at the opening of the balance valve is also constant. Therefore, regardless of the change of the load, the opening of the balance valve is stable, which eliminates the generation of jitter from the source and ensures the smooth and reliable operation of the auxiliary arm luffing action.

[0077] The engineering machinery with auxiliary arms and auxiliary arm luffing oil cylinders 1 has its own types, and is typically a crane as will be described below, but the above whole machine hydraulic system can also be applied to other engineering machinery, such as a pump machine and the like.

[0078] Hereinafter, the crane and its auxiliary arms and auxiliary arm luffing oil cylinders 1 will be taken as an example to specifically describe the present application.

[0079] The crane directly controls the luffing of the auxiliary arm by using a hydraulic cylinder (i.e. the auxiliary arm luffing oil cylinder 1), directly controls the luffing angle of the auxiliary arm through the extension and retraction of the cylinder, and bears the working torque through the lock chamber of the cylinder during work. The luffing angle of the auxiliary arm is directly controlled by the auxiliary arm luffing oil cylinder 1, the rodless cavity of the cylinder is a working pressure bearing cavity, supports the auxiliary arm, and hoists the heavy object.

[0080] The constant flow control valve group and the auxiliary boom control module of the present application can be connected to the whole machine hydraulic system of the crane, for example, the superstructure hydraulic system of the crane, and can be used as a subsystem of the general hydraulic system of the truck crane. The constant flow control valve group and the auxiliary boom control module can be easily connected to the original system to expand the function and realize the control of the auxiliary boom luffing action.

[0081] The auxiliary boom luffing cylinder 1 has multiple working states. In any state, the high pressure oil is provided by the main pump (i.e. the load sensing oil pump 17) of the whole machine, and the pressure signal for controlling the flow of the high pressure oil is provided by comparing the load pressure with the pump port pressure in the feedback oil path, as shown in FIG. 4.

[0082] The load sensing oil pump 17 not only provides oil for the auxiliary boom luffing cylinder 1 and its system, but also provides oil for the conventional actions (such as the main winch, auxiliary winch, luffing, and telescoping) of the crane through the main valve 18. The output flow is determined by comparing the pressure at the feedback port of the oil pump with the outlet pressure of the main pump. The pressure at the feedback port of the oil pump is provided by the feedback port at the main valve end through the oil path to the shuttle valve 19 shown in FIG. 4, and is determined by comparing with the feedback pressure signal of the auxiliary boom luffing system.

[0083] As shown in FIG. 5, in the working condition where the auxiliary boom is not used or the hook of the auxiliary boom does not carry a load, the electromagnets Y1 and Y2 are both de-energized. The high pressure oil enters the P port of the cartridge valve group through the pump quick-change joint 16, and most of the flow enters the side oil port cavity of the cartridge valve 12. A small part of the flow enters the cartridge reversing valve 15 through the first check valve 14. Since Y1 is de-energized, the pressure oil directly enters the control cavity of the cartridge valve 12 to push the cartridge valve core to cut off the oil path from the side oil port of the valve to the main oil outlet, thereby completing the self-locking. At the same time, since Y2 is de-energized, there is no pressure signal output from the main feedback oil port K, and the feedback oil path is cut off. Since the main oil path and the feedback oil path of the auxiliary boom luffing system are both cut off, there is no interference to the conventional action system, i.e. when the auxiliary boom is not used, the other conventional actions of the crane are not affected.

[0084] As shown in Figure 6, in the sub-arm action preparation state, the accumulator is filled with liquid. At this time, electromagnets Y1, Y2, Y3 are powered, and the electromagnet Y5 of the electric proportional overflow valve 10 is at a high pressure value. At this time, the high-pressure oil at the outlet of the main pump enters the P port of the cartridge valve group through the pump quick-change joint 16, and then enters the side oil port cavity of the cartridge valve 12. At this time, Y1 is powered, and the solenoid valve is in the powered state. The pressure oil in the control cavity of the cartridge valve enters the main return port TO of the cartridge reversing valve 15 through the powered state, and then communicates with the main return oil circuit through the pipeline, and finally communicates with the oil tank, the pressure is released, and the cartridge valve core moves left, the valve port is opened, and the oil circuit of the side oil port of the cartridge valve to the main oil outlet A is communicated, and the high-pressure oil passes through smoothly. Enter the first hose reel 5 (for large reel), and then enter the main reversing valve 7 through the long hose in the reel. At this time, the other oil enters the accumulator switch valve 8. Since Y3 is powered, the electromagnetic valve works in the on state, and the oil enters the accumulator 9 through the position. Therefore, the oil circuit between the main pump and the accumulator is unobstructed. Of course, the pipeline is connected, which does not mean that the main pump will fill the accumulator with liquid. It also needs related oil circuit to feedback the load pressure back to the main pump. The principle of the feedback oil circuit is that Y2 is powered, and the feedback switch valve 11 works in the on state. The pressure oil of the main oil circuit passes through the damper and enters the main feedback port K through the on state of the electromagnetic valve. Then it enters the load feedback port of the oil pump through the pump quick-change joint 16 and shuttle valve 19, and drives the main oil pump swash plate to increase the angle and increase the main oil pump flow output, thereby realizing the charging of the accumulator 9.

[0085] The accumulator charging pressure is controlled by the electric proportional overflow valve 10, as shown in Figure 7. The specific process is as follows: As the main pump charges the accumulator, the oil pressure in the accumulator 9 rises, and the feedback pressure also rises as the main pressure rises. When the pressure rises to the set value of the electric proportional overflow valve 10, the overflow valve opens, limiting the feedback pressure to the set value, thereby limiting the pressure of the main oil circuit. At this time, the pressure of the main oil circuit is converted into an electrical signal by the pressure sensor 13 and enters the electrical control system, reminding the operator that the system has completed the preparation before the action and can start to perform the corresponding sub-arm action.

[0086] As shown in Figure 8, after the preparation of the foregoing preparation state, a stable high-pressure oil source (i.e. the output oil pressure of the main pump delivered by the accumulator 9 and the first hose reel 5) is established at the inlet of the main reversing valve 7. At this time, the electromagnet Y4b is powered, and the electromagnetic valve right position works. The high-pressure oil at the inlet of the main reversing valve 7 enters the working oil port A (i.e. the first working oil port A1 of Figure 3) through the electromagnetic valve, and then enters the balance valve 2 through the pipeline and the second hose reel 4 (for small reel), and finally enters the rodless cavity of the luffing cylinder 1, extending the cylinder piston rod and completing the sub-arm luffing action.

[0087] When the cylinder action starts, with the switching of the main directional valve 7, although the main pump is still in the small displacement state, the output flow is not much, but the oil in the accumulator 9 can quickly supply to the cylinder rodless cavity through the pipeline, and due to the absence of the length of the pipeline in the first drum rubber pipe 5, the action of pushing out the piston rod can be performed in a very short time, that is, the response of the action of the auxiliary arm amplitude is good. During the pushing out of the piston rod, due to the presence of the elastic element of the accumulator 9, the flow pulsation in the pump itself and the variable process can be absorbed and eliminated, and the stability of the action can also be ensured.

[0088] As shown in Fig. 9, when the auxiliary arm amplitude action stops and the load of the weight is lifted, after the aforementioned auxiliary arm amplitude reaches the requirement, Y4b is de-energized, the main directional valve 7 is switched back to the neutral position, and due to the y-shaped function of the neutral position of the main directional valve 7, the pressure of the working port is directly released through the return port, and the cylinder action stops. Due to the locking action of the balance valve 2, the oil in the rodless cavity is locked to support the dead weight and the load of the auxiliary arm.

[0089] Referring to Fig. 10, when the amplitude cylinder piston rod is retracted and the auxiliary arm is lowered, Y4a is energized, the main directional valve 7 is switched to the left position, and the oil inlet of the main directional valve 7 is also connected to the accumulator 9 at this time. High-pressure oil enters the amplitude cylinder rod cavity directly through the second rubber pipe drum 4, and enters the balance valve pilot port to open the balance valve spool. The oil in the rodless cavity is released to realize the lowering action. Generally, this control mode of opening the rodless cavity balance valve by the pressure of the cylinder rod cavity has the disadvantage that the opening process is affected by the load pressure, and when the pressure changes, the situation of shaking easily occurs. During the lowering process of the auxiliary arm, the load changes inevitably, so shaking is easily generated. Strong shaking during the use of the auxiliary arm is very unfavorable to the safety of the load lifting and the stability of the whole vehicle.

[0090] In order to overcome this disadvantage, combined with Fig. 10 and Fig. 3, an overflow valve 6 is arranged at the high-pressure working port of the main directional valve 7 (that is, the cylinder rod cavity side) to limit the maximum pressure entering the cylinder rod cavity. The balance valve 2 of the embodiment includes a balance valve spool 21 and a sequence valve in parallel, an inlet damping 22 is arranged in front of the opening port (X port) of the balance valve spool 21, and then a bypass damping 23 is arranged in front of the opening port, and a pressure division structure is formed through the two dampings. Under the condition of constant total pressure (limited by the overflow valve 6), the pressure at the opening port of the balance valve is also constant, so that the opening of the balance valve is stable regardless of the change of the load, and the generation of shaking is eliminated from the source.

[0091] Of course, those skilled in the art can understand that the constant flow control valve group and the auxiliary arm control module of the present application can not be used, and a single connection can be added to the main valve 12, and the single connection uses an electro-hydraulic proportional reversing valve to control the auxiliary arm luffing oil cylinder 1 to complete the extension and retraction of the oil cylinder piston rod. This system can also be uniformly supplied with oil by a variable plunger pump, and the LS port of the current proportional reversing valve can send the load pressure back to the feedback port of the variable pump through the pipeline to increase the displacement of the oil pump, realize the stability of the system, and rely on the pilot current control of the proportional reversing valve to realize a certain degree of accurate flow output. However, the responsiveness of this alternative system is poor, and the action delay time is long.

[0092] In summary, the auxiliary arm control module (or auxiliary arm luffing system) of the present application can share a main pump with the original whole machine hydraulic system, without the need to add a high-pressure plunger pump, of course, without the need to add a power take-off or a larger torque pump serial port, and the volume and space occupation of the oil pump are more favorable. The auxiliary arm luffing system of the present application scheme can be directly connected to the existing whole machine hydraulic system as a sub-module in the form of three quick-change joints, without the need to change the original system, and in the prior art, the original system design must be adjusted and components must be selected and added, and the pipeline must be modified, which cannot form a modularized convenient and practical system. The system of the present application has good responsiveness, especially in the working condition of the main arm extending for a long time, a stable high-pressure source is established at the oil inlet of the main reversing valve through the preparation working condition, the pipeline between the main reversing valve and the oil cylinder is short, and as long as the solenoid valve is powered, the pressure oil can immediately enter the corresponding oil cylinder cavity, and the action response is timely and rapid; and in the prior art, due to the long-distance rubber pipe in the large reel, the system response is slow and the delay is long. Moreover, the stability of the system of the present application is high, and during the luffing process, due to the existence of the accumulator, a flexible component, the flow pulsation of the oil pump itself, the change of the system load, or the flow fluctuation caused by other factors can be absorbed and eliminated, so that the flow output is stable and continuous, and the action is always executed smoothly during the whole luffing process. In addition, the luffing process of the auxiliary arm luffing oil cylinder is stable, and in the luffing process, a constant pressure source + a pressure dividing liquid bridge is used to ensure that the opening pressure of the balance valve is stable, so as to ensure that the balance valve port is stable and is not affected by the change of the load pressure.

[0093] In the description of the present application, it should be understood that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0094] In this application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "fixed", and the like should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integrated; can be mechanical connection, can also be electrical connection or communication with each other; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0095] In the description of the present specification, the description referring to 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 present application. In the present 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. Furthermore, those skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

Claims

1. A constant flow control valve group, comprising: a cartridge valve (12) ; a cartridge reversing valve (15), comprising a working oil port on one side and a main return oil port (T0) and a reversing valve inlet port (P0) selectively connected with the working oil port on the other side, the working oil port being connected with a control oil port of the cartridge valve (12), the reversing valve inlet port (P0) being connected with a main inlet port (P) of the cartridge valve (12) ; a feedback on-off valve (11) arranged in a working feedback oil circuit connected between the main inlet port (P) of the cartridge valve (12) and a main feedback oil port (K) of the constant flow control valve group.

2. The constant flow control valve group according to claim 1, wherein The main feedback oil port (K), the main inlet port (P) and the main return oil port (T0) of the constant flow control valve group are respectively connected with pump quick-change connectors (16) for connecting to a hydraulic pump oil circuit.

3. The constant flow control valve group according to claim 1 or 2, wherein An inlet bypass oil circuit is connected between the main inlet port (P) of the cartridge valve (12) and the reversing valve inlet port (P0), and a first one-way valve (14) is arranged in the inlet bypass oil circuit, the first one-way valve (14) being arranged to allow hydraulic oil to flow from the main inlet port (P) to the reversing valve inlet port (P0) and to be blocked in the reverse direction.

4. The constant flow control valve group according to claim 3, wherein The main feedback oil port (K) is connected with a pressure sensor (13) and an electric proportional relief valve (10) ; and / or, a feedback damper is further arranged in the working feedback oil circuit in series with the feedback on-off valve (11) ; and / or, the cartridge reversing valve (15) and the feedback on-off valve (11) are both electromagnetic reversing valves.

5. The constant flow control valve group according to claim 3, wherein, A supplementary connection oil circuit is connected between the main outlet port (A) of the cartridge valve (12) and the reversing valve inlet port (P0), and a second one-way valve (14') is arranged in the supplementary connection oil circuit, the second one-way valve (14') being arranged to allow hydraulic oil to flow from the outlet port of the cartridge valve (12) to the reversing valve inlet port (P0) and to be blocked in the reverse direction. 6.A secondary arm control module, comprising: the constant flow control valve group according to any one of claims 1-5; and a main reversing valve (7), an inlet port (P1) of the main reversing valve (7) on one side being connected with the main outlet port (A) of the cartridge valve (12), a return oil port (T1) of the main reversing valve (7) on the other side being connected with the main return oil port (T0) of the constant flow control valve group, and working oil ports on the other side of the main reversing valve (7) being used for connecting a control secondary arm luffing oil cylinder (1). The secondary arm control module comprises:

7. The vice arm control module of claim 6, wherein, an accumulator (9) hydraulically connected to the inlet port (P1) of the main reversing valve (7) ; an accumulator on-off valve (8) for controlling the opening and closing of an oil circuit between the accumulator (9) and the inlet port (P1) of the main reversing valve (7). The working oil ports of the main reversing valve (7) comprise a first working oil port (A1) for hydraulically connecting a rodless chamber of the secondary arm luffing oil cylinder (1) and a second working oil port (A2) for hydraulically connecting a rod chamber of the secondary arm luffing oil cylinder (1), and the second working oil port (A2) is connected with a relief valve (6).

8. The vice arm control module of claim 6, wherein, ​ 9. The vice arm control module of claim 8, wherein, The first hose reel (5) is arranged in the connecting pipeline of the oil inlet (P1) and the oil return (T1) of the main reversing valve (7), and the second hose reel (4) is arranged in the connecting pipeline of the working oil port, and the outer end of the second hose reel (4) is provided with a cylinder quick-change joint (3) for connecting the cylinder oil circuit.

10. A complete machine hydraulic system, comprising: The auxiliary arm control module according to any one of claims 6-9; And An auxiliary arm luffing cylinder (1) connected with the working oil circuit of the main reversing valve (7).

11. The machine hydraulic system of claim 10, wherein, The auxiliary arm luffing cylinder (1) comprises a balance valve (2) arranged in the rodless cavity working oil circuit and used for locking the oil in the rodless cavity, the balance valve (2) comprises a balance valve core (21), a control port of the balance valve core (21) is connected to the rod cavity working oil circuit through a pilot oil circuit provided with an inlet damping (22) and connected to the low pressure side of the rodless cavity working oil circuit through a bypass oil circuit provided with a bypass damping (23).

12. The machine hydraulic system of claim 10, wherein, The complete machine hydraulic system further comprises: A load sensitive oil pump (17) and a main valve (18), the load sensitive oil pump (17) is used for pumping hydraulic oil towards the main valve (18) and the main inlet (P) of the constant flow control valve group respectively; A shuttle valve (19), a first comparison oil port of the shuttle valve (19) is connected to the feedback oil port of the main valve, and a second comparison oil port is connected to the main feedback oil port (K) of the constant flow control valve group, and an oil outlet of the shuttle valve (19) is connected to the pump feedback port of the load sensitive oil pump (17).

13. A crane comprising the complete machine hydraulic system according to any one of claims 10-12.

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