A boom damping valve, a damping valve hydraulic system, a control method and a construction machine

Abstract

The application discloses a boom damping valve and a boom damping system, and the boom damping valve mainly comprises a cone valve, an electromagnetic reversing valve, a liquid flushing valve and a check valve, the number of the cone valve is three, and the three cone valves are respectively a first cone valve, a second cone valve and a third cone valve; each cone valve comprises three oil ports. The boom damping valve adopts the cone valve structure instead of the spool valve structure, and the leakage of the spool valve is solved; the boom damping valve system only flushes the accumulator with liquid when the boom damping function is started, and the spool valve structure for comparing the pressure of the boom cylinder and the accumulator is cancelled; the accumulator is flushed and drained through two pressure sensors, a control module and an electromagnetic valve; intelligent control of the boom damping stable system is realized through a control program, the boom damping function is automatically turned off when the operation working device is operated, and the risk of the boom falling down when unloading is solved.

Description

Technical Field

[0001] This invention relates to a boom damping valve, a damping valve hydraulic system, a control method, and engineering machinery, belonging to the technical field of mechanical hydraulic systems. Background Technology

[0002] During transportation, the boom cylinder's large chamber, connected to a multi-way valve via pipeline, is a closed space. When traveling on bumpy roads, the machine's back-and-forth swaying causes vibration and impact on the working device, leading to material spillage and affecting overall transportation efficiency and driving comfort. To optimize loader vibration and impact during transportation, especially in high-end overseas markets, mainstream brands employ boom vibration damping systems. These systems connect the rodless chamber of the boom cylinder to an accumulator, which absorbs pressure shocks from the rodless chamber, thus reducing boom impact and providing cushioning and vibration reduction.

[0003] During loader operation, activating the boom damping function absorbs the pressure shock from the boom cylinder via an accumulator, adjusting the boom cylinder's extension and retraction to reduce the vertical movement of the working device, minimizing material spillage and improving overall machine comfort. Currently, most boom damping valves use a spool valve structure, resulting in significant leakage. During long-distance operation, their performance degrades or may even fail. Furthermore, some accumulator flushing methods connect the damping valve's flushing port to the pipeline between the multi-way valve and the boom cylinder; others connect it to the inlet of the multi-way valve. Both methods only allow flushing when the working device is operated, and the flushing pressure is set high, with high-pressure oil always present in the accumulator. Only when the boom damping function is activated does the accumulator release high-pressure oil by comparing the pressure in the boom cylinder's rodless chamber and the accumulator pressure through the spool valve structure, until the pressures in the boom cylinder's rodless chamber and the accumulator are equal. When the boom vibration damping function is activated, it cannot be stopped when operating the common working device. This causes the boom to be compressed a certain distance when the bucket is unloading to the bottom, resulting in the working device falling downwards, which poses a certain operational risk. Summary of the Invention

[0004] The purpose of this invention is to provide a boom damping valve, a damping valve hydraulic system, a control method, and engineering machinery, in order to solve the defects of boom damping valves, which mostly adopt a spool valve structure, resulting in large leakage, performance degradation during long-distance travel, and certain operational risks.

[0005] First aspect: A boom damping valve, the damping valve having ports A, B, a, b, T, LS, X, and P, and further comprising: The first cone valve has port 1 connected to port B of the damping valve, and port 2 of the first cone valve is connected to port T of the boom damping valve via the return oil circuit. The second cone valve has port 1 connected to port A and port a of the boom damping valve, and port 2 connected to port 1 of the third cone valve. The third cone valve, wherein port 1 of the third cone valve is connected to port 2 of the second cone valve, and port 2 of the third cone valve is connected to port T of the boom damping valve through the return oil circuit; The first electromagnetic reversing valve has its inlet connected to the 3 ports of the first cone valve. The inlet of the second solenoid directional valve is connected to port 3 of the second cone valve. The third solenoid directional valve has its inlet connected to port 3 of the third cone valve. The outlets of the first, second, and third solenoid directional valves are connected to port T of the boom damping valve via the internal return oil circuit. The fourth electromagnetic reversing valve has port 1 connected to the outlets of the first electromagnetic reversing valve and the second electromagnetic reversing valve; port 2 of the fourth electromagnetic reversing valve is connected to port 1 of the first cone valve and port a and port A of the boom damping valve. Flushing valve, wherein the inlet of the flushing valve is connected to the P port of the boom damping valve, and the outlet is connected to the X port and b port of the boom damping valve; The first check valve has its inlet connected to the outlet of the flushing valve. The second check valve has its inlet connected to port 1 of the second cone valve, port A of the boom damping valve, and port a.

[0006] Furthermore, port 3 of the fourth electromagnetic directional valve is connected to the non-spring chamber of the flushing valve and port LS of the boom damping valve. A first damper is provided on the oil circuit between port 3 of the fourth electromagnetic directional valve and the non-spring chamber of the flushing valve. When the fourth electromagnetic directional valve is in the right position, port 3 is connected to port 1. When the fourth electromagnetic directional valve is in the left position, port 3 is connected to port 2.

[0007] Furthermore, the outlet of the flushing valve is provided with a first damper and is connected to the X port and b port of the boom damping valve through a first one-way valve.

[0008] Furthermore, the second cone valve's port 2 is connected to the third cone valve's port 1 via a third damper, and the second one-way valve's inlet is connected to the third damper.

[0009] Furthermore, the right-side oil line from port 2 to port 3 of the second electromagnetic directional valve is equipped with a damper, and the oil line from port 1 to port 3 is equipped with a check valve. The left-side oil line from port 1 to port 3 of the second electromagnetic directional valve is equipped with a damper, and the oil line from port 2 to port 3 is equipped with a check valve.

[0010] Furthermore, an overflow valve is provided in the oil line between the X port, b port and T port of the boom damping valve. The inlet of the overflow valve is connected to the X port and b port of the boom damping valve, and the outlet of the overflow valve is connected to the T port of the boom damping valve.

[0011] The second aspect: An engineering machine includes the boom damping valve described in the first aspect, configured as a pipeline of the boom cylinder of the engineering machine.

[0012] Third aspect: A boom damping hydraulic system for boom damping valve includes a variable pump, a boom cylinder, a shuttle valve, a multi-way valve, a control module, a first pressure sensor, and a second pressure sensor. The control module is used to control the operation of the first, second, third and fourth solenoid directional valves of the boom damping valve. The rodless chamber of the boom cylinder is connected to port A of the boom damping valve, and the rod chamber is connected to port B of the boom damping valve; the left port of the shuttle valve is connected to port LS of the boom damping valve, the port LS of the multi-way valve is connected to the right inlet of the shuttle valve, port A of the multi-way valve is connected to the rodless chamber of the boom cylinder, and port B of the multi-way valve is connected to the rod chamber of the boom cylinder. The outlet of the variable pump is connected to the inlet of the multi-way valve and the P port of the boom damping valve, and the control port of the variable pump is connected to the outlet of the shuttle valve. The first pressure sensor and the second pressure sensor are used to collect the pressure at ports a and b of the boom damping valve; The variable pump inlet, the T-port of the multi-way valve, and the T-port of the boom damping valve are sequentially connected to a return oil filter and a hydraulic oil tank.

[0013] Furthermore, the first pressure sensor is connected to port b of the boom damping valve, the second pressure sensor is connected to port a of the boom damping valve, and the first pressure sensor and the second pressure sensor are connected to the control module.

[0014] Furthermore, it also includes an accumulator, which is connected to the X port of the boom damping valve.

[0015] Fourth aspect: A control method for a boom vibration damping hydraulic system, the method comprising: When the boom vibration damping function is activated, the multi-way valve is in the neutral position, and the control module simultaneously outputs an electrical signal: After the third solenoid directional valve is energized, it is in the left position. Port 1 and port 2 of the third cone valve are not connected. The accumulator and port 2 of the second cone valve are not connected to the return oil circuit and are in a closed state. After the fourth solenoid directional valve is energized, it is in the left position. Ports 2 and 3 of the fourth solenoid directional valve are connected, which transmits the pressure signal of the rodless chamber of the boom cylinder to the shuttle valve and simultaneously to the flushing valve, causing the flushing valve to switch. This allows the pressure oil flowing from the outlet of variable pump 1 to port P of the boom damping valve to pass through the left position of the flushing valve, the first damper, and the first check valve, and then enter the accumulator from port X of the boom damping valve to flush the accumulator. When the pressure signals from the first pressure sensor and the second pressure sensor show that the pressure at ports a and b of the boom damping valve is the same, the accumulator stops flushing, and the control module simultaneously outputs an electrical signal to the first solenoid directional valve and the second solenoid directional valve. After the first solenoid directional valve is energized, it is in the left position, which causes the hydraulic oil in the spring chamber of the first cone valve to flow to the return oil line through the first solenoid directional valve. At this time, port 1 and port 2 of the first cone valve are connected, so that the rod chamber of the boom cylinder is connected to the return oil line of port T of the boom damping valve. After the second solenoid directional valve is energized, it is in the left position, which allows the hydraulic oil in the spring chamber of the second cone valve to flow to the return oil line through the second solenoid directional valve. Port 1 and port 2 of the second cone valve are connected, thereby connecting the rodless chamber of the boom cylinder with the accumulator. The accumulator absorbs the pressure impact of the rodless chamber of the boom cylinder, achieving buffering and vibration reduction.

[0016] Furthermore, the method also includes: When the boom damping function is activated, under the control of the control module, the first solenoid directional valve is energized, connecting the rod chamber of the boom cylinder to the T-port return oil circuit of the boom damping valve; the second solenoid directional valve is energized, connecting the rodless chamber of the boom cylinder to the accumulator, which absorbs the pressure impact of the rodless chamber of the boom cylinder. If, at this time, the control module receives a signal from the operating handle and the multi-way valve is in working condition, the control module de-energizes the first and second solenoid directional valves, placing both valves in the right position. This disconnects the rod chamber of the boom cylinder from the T-port return oil circuit of the boom damping valve, and the rodless chamber of the boom cylinder is also disconnected from the accumulator, rendering the boom damping valve ineffective.

[0017] Furthermore, when the starter arm vibration damping function is not activated, there is no operating handle model, or the whole machine is powered off, the control module does not receive enable switch signals or handle signals, the multi-way valve is in the neutral position, and the first solenoid valve, the second solenoid valve, the third solenoid valve, and the fourth solenoid valve are in the initial position. When the first solenoid valve directional valve is in the right position, the check valve in the right position prevents the hydraulic oil in the spring chamber of the first cone valve from being unloaded to the return oil circuit through the first solenoid valve directional valve. The first cone valve is in a closed state, and the hydraulic oil cannot flow from port 1 to port 2 through port 1 of the first cone valve. When the second solenoid valve is in the right position, the oil port 3 to oil port 1 of the second cone valve is blocked due to the action of the right-position check valve of the second solenoid valve. This prevents the hydraulic oil in the spring chamber from flowing to the return oil line through the second solenoid valve. At the same time, the right-position oil port 2 to 1 of the second solenoid valve are connected, so that port 1 of the second cone valve is connected to port 3 of the second cone valve through the second check valve. The second cone valve is in a closed state, and ports 1 and 2 of the second cone valve are not connected. Thus, the rodless chamber of the boom cylinder is not connected to the accumulator. When the third solenoid valve is in the right position, the hydraulic oil in the spring chamber of the third cone valve flows to the return oil line through the third solenoid valve. At this time, port 1 and port 2 of the third cone valve are connected, so the accumulator, port 2 of the second cone valve, the first check valve and port T of the boom damping valve are connected and are in a low-pressure state. With the fourth solenoid valve in the right position, ports 3 and 1 of the fourth solenoid valve are connected, allowing the LS oil in the boom damper valve to flow into the return oil circuit. There is no load feedback signal to the variable pump control signal. Simultaneously, the directional valve is in the left position under the action of the spring, blocking the inlet and outlet of the flushing valve, and the variable pump is in standby mode. Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The boom damping valve of this invention adopts a cone valve structure instead of a slide valve structure, thus solving the problem of leakage of slide valves; The boom damping valve system of this invention only flushes the accumulator after the boom damping function is activated, and eliminates the slide valve structure that compares the pressure between the boom cylinder and the accumulator. The flushing and discharging of the accumulator is achieved through two pressure sensors, a control module, and a solenoid valve. This invention achieves intelligent control of the boom vibration reduction and stabilization system through a control program. When the working device is operated, the boom vibration reduction function is automatically turned off, thus eliminating the risk of the boom pressing down and falling during unloading. When the machine is powered off or the boom damping function is manually turned off, the accumulator pressure oil is automatically released, so that when the boom damping function is not activated, the accumulator is connected to the return oil line and is in a low-pressure state. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the boom damping valve of the present invention; Figure 2 This is a structural schematic diagram of the boom vibration reduction system; In the diagram: 1. Variable displacement pump, 2. Shuttle valve, 3. Boom damping valve, 3.1. First cone valve, 3.2. Second cone valve, 3.3. Third cone valve, 3.4. First solenoid valve, 3.5. Second solenoid valve, 3.6. Third solenoid valve, 3.7. Fourth solenoid valve, 3.8. Flushing valve, 3.9. Second damper, 3.10. First damper, 3.11. Third damper, 3.12. First check valve, 3.13. Second check valve, 3.14. Relief valve, 4. Multi-way valve, 5. Accumulator, 6. First pressure sensor, 7. Second pressure sensor, 8. Boom cylinder, 9. Control module, 10. Return oil filter element, 11. Hydraulic oil tank. Implementation

[0019] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments. Example 1

[0020] like Figure 1 As shown, an embodiment of the present invention provides a boom damping valve, which has ports A, B, X, P, T, LS, a, and b, and includes a cone valve, a solenoid directional valve, a flushing valve, a check valve, and a damper.

[0021] There are 3 cone valves, namely the first cone valve 3.1, the second cone valve 3.2, and the third cone valve 3.3, and each cone valve includes 3 oil ports.

[0022] The number of solenoid directional valves is 4, namely, the first solenoid directional valve 3.4, the second solenoid directional valve 3.5, the third solenoid directional valve 3.6, and the fourth solenoid directional valve 3.7.

[0023] Port 1 of the first cone valve 3.1 is connected to port B of the boom damping valve 3, port 2 of the first cone valve 3.1 is connected to port T of the boom damping valve 3 through the return oil circuit, and port 3 of the first cone valve 3.1 is connected to the inlet of the first solenoid directional valve 3.4.

[0024] Port 1 of the second cone valve 3.2 is connected to port A of the boom damping valve 3, port a of the boom damping valve 3, and port 2 of the fourth solenoid directional valve 3.7. Port 2 of the second cone valve 3.2 is connected to port 1 of the third damper 3.11 and the third cone valve 3.3 through an internal oil circuit. Port 3 of the second cone valve 3.2 is connected to port 3 of the second solenoid directional valve 3.5. Port 1 of the third cone valve 3.3 is connected to port 2 of the second cone valve 3.2. Port 2 of the third cone valve 3.3 is connected to the boom damping valve T via the return oil circuit. Port 3 of the third cone valve 3.3 is connected to the inlet of the third solenoid directional valve 3.6.

[0025] The first solenoid directional valve 3.4, the second solenoid directional valve 3.5, and the third solenoid directional valve 3.6 are two-position two-way directional valves; the first solenoid directional valve 3.4 is a two-position two-way directional valve, with a check valve configured in the left position oil passage structure and a damping orifice configured in the right position structure. The second solenoid directional valve 3.5 is a two-position three-way solenoid valve. The right position oil line from port 2 to port 3 is equipped with damping, and the oil line from port 1 to port 3 is equipped with a check valve. Hydraulic oil can flow from port 1 to port 3, but cannot flow from port 3 to port 1. The left position oil line from port 1 to port 3 is equipped with damping, and the oil line from port 2 to port 3 is equipped with a check valve. Hydraulic oil can flow from port 2 to port 3, but cannot flow from port 3 to port 2. The third solenoid directional valve 3.6 has a damping orifice in its left-side oil passage structure and a check valve in its right-side structure; and the outlets of the first solenoid directional valve 3.4, the second solenoid directional valve 3.5, and the third solenoid directional valve 3.6 are connected to the T-port of the boom damping valve 3 through the internal return oil passage of the boom damping valve 3.

[0026] The fourth solenoid directional valve 3.7 is a two-position three-way directional valve. Its port 1 is connected to the outlet of the first solenoid directional valve 3.4 and the second solenoid directional valve 3.5; its port 2 is connected to port 1 of the second cone valve 3.2 and ports a and A of the boom damping valve 3; its port 3 is connected to the non-spring chamber of the flushing valve 3.8, the second damper 3.9, and port LS of the boom damping valve 3. When the fourth solenoid directional valve 3.7 is in the right position, its port 3 is connected to port 1; when the fourth solenoid directional valve 3.7 is in the left position, its port 3 is connected to port 2.

[0027] The inlet of the flushing valve 3.8 is connected to the P port of the boom damping valve 3, and the outlet of the flushing valve 3.8 is connected to the X port and b port of the boom damping valve 3 through the first damping hole 3.10 and the first one-way valve 3.12.

[0028] The inlet of the first one-way valve 3.12 is connected to the third damper 3.11, and the outlet of the first one-way valve 3.12 is connected to port 2 of the second cone valve 3.2, port 1 of the third cone valve 3.3, port X and port b of the boom damping valve 3.

[0029] The inlet of the second check valve 3.13 is connected to port 1 of the second cone valve 3.2, port A and port a of the boom damping valve, and the outlet of the second check valve 3.13 is connected to port 2 of the second solenoid valve 3.5.

[0030] The inlet of the flushing valve 3.8 is connected to the P port of the boom damping valve 3, and the outlet of the flushing valve 3.8 is connected to the X port and b port of the boom damping valve 3 through the first damper 3.10 and the first one-way valve 3.11.

[0031] The inlet of the first one-way valve 3.11 is connected to the first damper 3.10, and the outlet of the first one-way valve 3.11 is connected to port 2 of the second cone valve 3.2, the inlet of the third damper 3.11, port X of the boom damping valve 3, and port b.

[0032] The inlet of the overflow valve 3.13 is connected to the X port and b port of the boom damping valve 3, and the outlet of the overflow valve 3.12 is connected to the T port of the boom damping valve 3. Example 2

[0033] like Figure 2 As shown, this embodiment of the invention provides a boom vibration damping system, including a boom vibration damping valve 3 as described in Embodiment 1. The P port of the boom vibration damping valve 3 is connected to the outlet of the variable pump 1, the A port of the boom vibration damping valve 3 is connected to the rodless chamber of the boom cylinder 8, the B port of the boom vibration damping valve 3 is connected to the rod chamber of the boom cylinder 8, the T port of the boom vibration damping valve 3 is connected to the hydraulic oil tank 11 through the return oil pipeline and the return oil filter element 10, the X port of the boom vibration damping valve 3 is connected to the accumulator 5, the LS port of the boom vibration damping valve 3 is connected to the left end oil port of the shuttle valve 2, the a port of the boom vibration damping valve 3 is connected to the second pressure sensor 7, and the b port of the boom vibration damping valve 3 is connected to the first pressure sensor 6.

[0034] It also includes a variable pump 1 and a multi-way valve 4. The inlet of the variable pump 1 is connected to the hydraulic oil tank 11, and the outlet is connected to the inlet of the multi-way valve 4 and the P port of the boom damping valve. The control port of the variable pump 1 is connected to the outlet of the shuttle valve 2.

[0035] The multi-way valve 4 is a load-sensitive closed-center multi-way valve. The LS port of the multi-way valve 4 is connected to the right end inlet of the shuttle valve 2. The T port of the multi-way valve 4 is connected to the hydraulic oil tank 11 through the return oil pipeline and the return oil filter element 10. The A port of the multi-way valve 4 is connected to the rodless chamber of the boom cylinder 8. The B port of the multi-way valve 4 is connected to the rod chamber of the boom cylinder 8.

[0036] It includes two pressure sensors, namely a first pressure sensor 6 and a second pressure sensor 7. The first pressure sensor 6 is connected to port b of the boom damping valve 3, and the second pressure sensor 7 is connected to port a of the boom damping valve 3. The first pressure sensor 6 and the second pressure sensor 7 are respectively connected to the control module 3.

[0037] It also includes a pressure control module 3, which is connected to the first solenoid directional valve 3.4, the second solenoid directional valve 3.5, the third solenoid directional valve 3.6, and the fourth solenoid directional valve 3.7 of the boom damping valve 3. The control module 3 receives signals from the first pressure sensor 6, the second pressure sensor 2, the control handle, the vehicle speed, and the damping function enable switch signal, and outputs electrical signals to control the switching actions of the first solenoid directional valve 3.4, the second solenoid directional valve 3.5, the third solenoid directional valve 3.6, and the fourth solenoid directional valve 3.7 of the boom damping valve 3.

[0038] It also includes an accumulator 5, which is connected to the X port of the boom damping valve.

[0039] Example 3: Also disclosed is a type of construction machinery, including the boom damping valve described in Example 1, which is configured as a pipeline of the boom cylinder of the construction machinery.

[0040] Example 4: A control method for a boom vibration damping system is also disclosed, which specifically includes the following: When the starter arm vibration damping function is not activated, there is no operating handle, or the entire machine is powered off, the control module 3 does not receive enable switch signals or handle signals, the multi-way valve 4 is in the neutral position, and the first solenoid valve 3.4, the second solenoid valve 3.5, the third solenoid valve 3.6, and the fourth solenoid valve 3.7 are in the initial position.

[0041] When the first solenoid valve directional valve 3.4 is in the right position, the check valve in the right position prevents the hydraulic oil in the spring chamber of the first cone valve 3.1 from being unloaded to the return oil circuit through the first solenoid valve directional valve 3.4. The first cone valve 3.1 is in a closed state, and the hydraulic oil cannot flow from port 1 to port 2 through port 1 of the first cone valve 3.1.

[0042] When the second solenoid valve directional valve 3.5 is in the right position, the oil port 3 of the second cone valve 3.2 is blocked from the oil port 1 of the second solenoid valve due to the action of the right-position check valve of the second solenoid valve 3.5. This prevents the hydraulic oil in the spring chamber from flowing to the return oil line through the second solenoid valve 3.5. At the same time, the right-position oil port 2 of the second solenoid valve 3.5 is connected to port 1, so that port 1 of the second cone valve 3.2 is connected to port 3 through the second check valve. The second cone valve 3.2 is in a closed state, and ports 1 and 2 of the second cone valve 3.2 are blocked. Therefore, the rodless chamber of the boom cylinder 8 is blocked from the accumulator 5.

[0043] When the third solenoid valve 3.6 is in the right position, the hydraulic oil in the spring chamber of the third cone valve 3.3 flows to the return oil line through the third solenoid valve 3.6. At this time, port 1 and port 2 of the third cone valve 3.3 are connected, so the accumulator 5, port 2 of the second cone valve 3.2, check valve 3.12 and port T of the boom damping valve are connected and are in a low-pressure state.

[0044] The fourth solenoid valve 3.7 is in the right position, and port 3 and port 1 of the fourth solenoid valve 3.7 are connected, so that the LS oil of the boom damping valve 3 is connected to the return oil circuit, and there is no load feedback signal to the variable pump control signal. At the same time, the directional valve 3.8 is in the left position under the action of the spring, the inlet and outlet of the flushing valve 3.8 are not connected, and the variable pump is in standby state.

[0045] When the boom vibration reduction function is activated, the boom switch signal is transmitted to the control module 3. At the same time, the no-operation handle is transmitted to the control module 3. At this time, the multi-way valve 4 is in the neutral position.

[0046] Control module 3 simultaneously outputs electrical signals to the third solenoid directional valve 3.6 and the fourth solenoid directional valve 3.7.

[0047] After the third solenoid directional valve 3.6 is energized, it is in the left position. The left position of the check valve prevents the hydraulic oil in the spring chamber of the third cone valve 3.3 from flowing to the return oil line through the third solenoid directional valve 3.6. At this time, port 1 and port 2 of the third cone valve 3.3 are not connected, so the accumulator 5 and port 2 of the second cone valve 3.2 are in a closed state, ready for the accumulator to be flushed.

[0048] After the fourth solenoid directional valve 3.7 is energized, it is in the left position, and ports 2 and 3 of the fourth solenoid directional valve 3.7 are connected. Thus, the pressure signal of the rodless chamber of the boom cylinder 8 is transmitted through ports 2 and 3 of the fourth solenoid valve, through the second damping orifice 3.9, and the shuttle valve 2 to the control end of the variable pump 1. The pressure of the rodless chamber of the boom cylinder 8 is transmitted to the shuttle valve 2 and simultaneously to the flushing valve 3.8. The flushing valve 3.8 reverses, so that the pressure oil flowing from the outlet of the variable pump 1 to the P port of the boom damping valve 3 passes through the left position of the flushing valve 3.8, the first damper 3.10, and the check valve 3.12, and enters the accumulator 5 from the X port of the boom damping valve to flush the accumulator.

[0049] When the pressure signals received by the control module 3 from the first pressure sensor 6 and the second pressure sensor 7 show that the pressures at ports a and b of the boom damping valve 3 (port a pressure is the rodless chamber pressure of the boom cylinder 8, and port b pressure is the accumulator 5 pressure) are the same, the control module 3 outputs an electrical signal to de-energize the fourth solenoid valve 3.7, causing the fourth solenoid valve 3.7 to switch to the right position. Ports 3 and 1 of the fourth solenoid valve 3.7 are connected, and the oil circuit from port 3 of the fourth solenoid valve 3.7 to the control end of the variable pump 1 is unloaded. The flushing valve 3.8 switches to the right position, and the accumulator 5 stops flushing.

[0050] After the accumulator stops flushing, the control module 3 detects the vehicle speed signal. When the speed exceeds the set speed, the control module 3 simultaneously outputs an electrical signal to the first solenoid directional valve 3.4 and the second solenoid directional valve 3.7.

[0051] After the first solenoid directional valve 3.4 is energized, it is in the left position, which allows the hydraulic oil in the spring chamber of the first cone valve 3.1 to flow to the return oil line through the first solenoid directional valve 3.4. At this time, port 1 and port 2 of the first cone valve 3.1 are connected, so that the rod chamber of the boom cylinder is connected to the return oil line of port T of the boom damping valve 3.

[0052] After the second solenoid directional valve 3.5 is energized, it is in the left position, which allows the hydraulic oil in the spring chamber of the second cone valve 3.5 to flow to the return oil line through the second solenoid directional valve 3.5. At this time, port 1 and port 2 of the second cone valve 3.2 are connected, so that the rodless chamber of the boom cylinder is connected to the accumulator 5. The accumulator 5 can absorb the pressure impact of the rodless chamber of the boom cylinder 8, and realize the buffering and vibration reduction effect.

[0053] When the boom damping function is activated, under the control of the control module 3, the first solenoid directional valve 3.4 is energized, connecting the rod chamber of the boom cylinder 8 to the T-port return oil circuit of the boom damping valve 3; the second solenoid directional valve 3.5 is energized, connecting the rodless chamber of the boom cylinder 8 to the accumulator 5, which can absorb the pressure impact of the rodless chamber of the boom cylinder 8. If, at this time, the control module 3 receives a signal from the operating handle and the multi-way valve 4 is in working condition, the control module 3 de-energizes the first solenoid directional valve 3.4 and the second solenoid directional valve 3.5, placing both valves in the right position. This disconnects the rod chamber of the boom cylinder 8 from the T-port return oil circuit of the boom damping valve 3, and also disconnects the rodless chamber of the boom cylinder 8 from the accumulator 5, rendering the boom damping valve ineffective.

[0054] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A boom damper valve having an A port, a B port, an a port, a b port, a T port, an LS port, an X port, and a P port, characterized by, Also includes: The first cone valve has port 1 connected to port B of the damping valve, and port 2 of the first cone valve is connected to port T of the boom damping valve via the return oil circuit. The second cone valve has port 1 connected to port A and port a of the boom damping valve, and port 2 connected to port 1 of the third cone valve. The third cone valve, wherein port 1 of the third cone valve is connected to port 2 of the second cone valve, and port 2 of the third cone valve is connected to port T of the boom damping valve through the return oil circuit; The first electromagnetic reversing valve has its inlet connected to the three ports of the first cone valve. The inlet of the second solenoid directional valve is connected to port 3 of the second cone valve. The third solenoid directional valve has its inlet connected to port 3 of the third cone valve. The outlets of the first, second, and third solenoid directional valves are connected to port T of the boom damping valve via the internal return oil circuit. The fourth electromagnetic reversing valve has port 1 connected to the outlets of the first electromagnetic reversing valve and the second electromagnetic reversing valve; port 2 of the fourth electromagnetic reversing valve is connected to port 1 of the first cone valve and port a and port A of the boom damping valve. Flushing valve, wherein the inlet of the flushing valve is connected to the P port of the boom damping valve, and the outlet is connected to the X port and b port of the boom damping valve; The first check valve has its inlet connected to the outlet of the flushing valve. The second check valve has its inlet connected to port 1 of the second cone valve, port A of the boom damping valve, and port a.

2. The boom damping valve according to claim 1, characterized in that, The third port of the fourth electromagnetic directional valve is connected to the non-spring chamber of the flushing valve and the LS port of the boom damping valve. The oil circuit between the third port of the fourth electromagnetic directional valve and the non-spring chamber of the flushing valve is provided with a first damper. When the fourth electromagnetic directional valve is in the right position, its third port is connected to its first port. When the fourth electromagnetic directional valve is in the left position, its third port is connected to its second port.

3. The boom damping valve according to claim 1, characterized in that, The outlet of the flushing valve is equipped with a first damper and is connected to the X port and b port of the boom damping valve through a first one-way valve.

4. The boom damping valve according to claim 1, characterized in that, The second cone valve's port 2 is connected to the third cone valve's port 1 via a third damper, and the second check valve's inlet is connected to the third damper.

5. The boom damping valve according to claim 1, characterized in that, The right-side oil line from port 2 to port 3 of the second electromagnetic directional valve is equipped with a damper, and the oil line from port 1 to port 3 is equipped with a check valve. The left-side oil line from port 1 to port 3 of the second electromagnetic directional valve is equipped with a damper, and the oil line from port 2 to port 3 is equipped with a check valve.

6. The boom damping valve according to claim 1, characterized in that, An overflow valve is provided in the oil line between the X port, b port and T port of the boom damping valve. The inlet of the overflow valve is connected to the X port and b port of the boom damping valve, and the outlet of the overflow valve is connected to the T port of the boom damping valve.

7. An engineering machinery, characterized in that, The boom damping valve, as described in any one of claims 1-6, is configured on the pipeline of the boom cylinder of the construction machinery.

8. A boom damping hydraulic system based on the boom damping valve according to any one of claims 1-6, characterized in that, It includes a variable displacement pump, boom cylinder, shuttle valve, multi-way valve, control module, first pressure sensor and second pressure sensor; The control module is used to control the operation of the first, second, third and fourth solenoid directional valves of the boom damping valve. The rodless chamber of the boom cylinder is connected to port A of the boom damping valve, and the rod chamber is connected to port B of the boom damping valve; the left port of the shuttle valve is connected to port LS of the boom damping valve, the port LS of the multi-way valve is connected to the right inlet of the shuttle valve, port A of the multi-way valve is connected to the rodless chamber of the boom cylinder, and port B of the multi-way valve is connected to the rod chamber of the boom cylinder. The outlet of the variable pump is connected to the inlet of the multi-way valve and the P port of the boom damping valve, and the control port of the variable pump is connected to the outlet of the shuttle valve. The first pressure sensor and the second pressure sensor are used to collect the pressure at ports a and b of the boom damping valve; The variable pump inlet, the T-port of the multi-way valve, and the T-port of the boom damping valve are sequentially connected to a return oil filter and a hydraulic oil tank.

9. The boom vibration damping hydraulic system according to claim 8, characterized in that, The first pressure sensor is connected to port b of the boom damping valve, and the second pressure sensor is connected to port a of the boom damping valve. The first pressure sensor and the second pressure sensor are connected to the control module.

10. The boom vibration damping hydraulic system according to claim 8, characterized in that, It also includes an accumulator, which is connected to the X port of the boom damping valve.

11. A control method based on the boom vibration damping hydraulic system according to claim 8, characterized in that, The method includes: When the boom vibration damping function is activated, the multi-way valve is in the neutral position, and the control module simultaneously outputs an electrical signal: After the third solenoid directional valve is energized, it is in the left position. Port 1 and port 2 of the third cone valve are not connected. The accumulator and port 2 of the second cone valve are not connected to the return oil circuit and are in a closed state. After the fourth solenoid directional valve is energized, it is in the left position. Ports 2 and 3 of the fourth solenoid directional valve are connected, which transmits the pressure signal of the rodless chamber of the boom cylinder to the shuttle valve and simultaneously to the flushing valve, causing the flushing valve to switch. This allows the pressure oil flowing from the outlet of the variable pump to the P port of the boom damping valve to pass through the left position of the flushing valve, the first damper, and the first check valve, and then enter the accumulator from the X port of the boom damping valve to flush the accumulator. When the pressure signals from the first pressure sensor and the second pressure sensor show that the pressure at ports a and b of the boom damping valve is the same, the accumulator stops flushing, and the control module simultaneously outputs an electrical signal to the first solenoid directional valve and the second solenoid directional valve. After the first solenoid directional valve is energized, it is in the left position, which causes the hydraulic oil in the spring chamber of the first cone valve to flow to the return oil line through the first solenoid directional valve. At this time, port 1 and port 2 of the first cone valve are connected, so that the rod chamber of the boom cylinder is connected to the return oil line of port T of the boom damping valve. After the second solenoid directional valve is energized, it is in the left position, which allows the hydraulic oil in the spring chamber of the second cone valve to flow to the return oil line through the second solenoid directional valve. Port 1 and port 2 of the second cone valve are connected, thereby connecting the rodless chamber of the boom cylinder with the accumulator. The accumulator absorbs the pressure impact of the rodless chamber of the boom cylinder, achieving buffering and vibration reduction.

12. The control method for the boom vibration damping hydraulic system according to claim 11, characterized in that, The method further includes: When the boom damping function is activated, under the control of the control module, the first solenoid directional valve is energized, connecting the rod chamber of the boom cylinder to the T-port return oil circuit of the boom damping valve; the second solenoid directional valve is energized, connecting the rodless chamber of the boom cylinder to the accumulator, which absorbs the pressure impact of the rodless chamber of the boom cylinder. If, at this time, the control module receives a signal from the operating handle and the multi-way valve is in working condition, the control module de-energizes the first and second solenoid directional valves, placing both valves in the right position. This disconnects the rod chamber of the boom cylinder from the T-port return oil circuit of the boom damping valve, and the rodless chamber of the boom cylinder is also disconnected from the accumulator, rendering the boom damping valve ineffective.

13. The control method for the boom vibration damping hydraulic system according to claim 11, characterized in that, The method further includes: when the starter arm vibration damping function is not activated, there is no operating handle signal, or the whole machine is powered off, the control module does not receive the enable switch signal or the handle signal, the multi-way valve is in the neutral position, and the first solenoid valve, the second solenoid valve, the third solenoid valve, and the fourth solenoid valve are in the initial position. When the first solenoid valve directional valve is in the right position, the check valve in the right position prevents the hydraulic oil in the spring chamber of the first cone valve from being unloaded to the return oil circuit through the first solenoid valve directional valve. The first cone valve is in a closed state, and the hydraulic oil cannot flow from port 1 to port 2 through port 1 of the first cone valve. When the second solenoid valve is in the right position, the right-position check valve of the second solenoid valve prevents the connection between port 3 of the second cone valve and port 1 of the second solenoid valve. This prevents the hydraulic oil in the spring chamber from flowing to the return oil line through the second solenoid valve. At the same time, ports 2 and 3 of the second solenoid valve are connected, allowing port 1 of the second cone valve to connect with port 3 of the second cone valve through the second check valve. The second cone valve is in a closed state, and ports 1 and 2 of the second cone valve are not connected. As a result, the rodless chamber of the boom cylinder is not connected to the accumulator. When the third solenoid valve is in the right position, the hydraulic oil in the spring chamber of the third cone valve flows to the return oil line through the third solenoid valve. At this time, port 1 and port 2 of the third cone valve are connected, so the accumulator, port 2 of the second cone valve, the first check valve and port T of the boom damping valve are connected and are in a low-pressure state. The fourth solenoid valve is in the right position, and port 3 and port 1 of the fourth solenoid valve are connected, so that the LS oil of the boom damping valve is connected to the return oil circuit. There is no load feedback signal to the variable pump control signal. At the same time, the directional valve is in the left position under the action of the spring, the inlet and outlet of the flushing valve are not connected, and the variable pump is in standby state.

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