A compact flow distribution valve based on a dual pump system of a truck-mounted crane

Abstract

This utility model relates to a compact flow distribution valve based on a truck-mounted crane dual-pump system, including a control valve with a P port, a P' port, and a T port. The P port is connected to the control oil circuit of the actuator, and the T port is connected to the return oil channel. An overflow valve is connected to the control valve and the return oil channel. A confluence valve is connected to the small pump, the large pump, the P' port of the control valve, and the return oil channel. The confluence valve core opens and closes based on the oil output state of the control valve's P' port. When the oil pressure entering the control valve does not exceed its overflow pressure, the control valve opens the P port and P' port; when the oil pressure entering the control valve exceeds its overflow pressure, the control valve opens the P' port and T port. This compact flow distribution valve based on a truck-mounted crane dual-pump system eliminates the need for pressure sensors, solenoid valves, and other electrical components, solving the problems of high system heat generation, energy inefficiency, and engine stalling caused by high-pressure unloading of the small pump.

Description

Technical Field

[0001] This utility model relates to a compact flow distribution valve based on a truck-mounted crane dual-pump system. Background Technology

[0002] With the continuous development and expansion of construction machinery, the technical requirements for the hydraulic system of the entire vehicle are becoming increasingly stringent. Simultaneously, there are demands for highly integrated, compact, and less operator-fatigue-prone control and components of various actuators. For example, in the field of truck-mounted cranes for construction machinery, to improve work efficiency and operational stability, more and more manufacturers are optimizing the main pump of the system from a single pump to a dual pump, requiring the winch and boom to combine their flow to improve efficiency. However, under heavy-load conditions, the smaller pump cannot participate in the flow combination because the main relief valve is pressure-limited and the check valve cannot open. Typically, the pressure of the small pump's main relief valve is set at 21MPa, and the pressure of the large pump's main relief valve is set at 26MPa. When the flow combination valve core opens, the load-sensitive pressure is also in a combined state, but the load-sensitive pressure of the small pump is not cut off. The oil from the small pump can only generate heat during operation, and some special-purpose vehicle engines may stall due to insufficient torque. This also leads to the following problems in the hydraulic system: 1. Excessive and rapid temperature rise, reducing efficiency and the service life of hydraulic components; 2. Sudden engine stall during lifting operations, posing safety hazards such as rollover, boom breakage, and wire rope breakage.

[0003] To address the aforementioned issues, several additional measures were implemented on top of the downstream compensated LUDV flow distribution valve: 1. Using pressure sensors and solenoid valves: When the control pressure for switching the confluence valve core reaches 16MPa, the solenoid valve is energized and unloaded, the confluence valve core closes, the small pump does not participate in confluence, and neither the main flow path nor the load-sensitive flow path merges. The small pump oil is unloaded at low pressure through a three-way flow valve. However, this system increases the number of pipelines and complicates the electrical control components. Insufficient sensor accuracy can cause the confluence valve core to float, resulting in sudden acceleration of the confluence action and sudden slowing of the non-confluence action, leading to unstable and unsafe operation. Furthermore, the oil unloaded by the solenoid valve is the working flow path oil, further reducing efficiency. 2. Using multiple pressure sensors and solenoid valves, and switching the valve core to a confluence state at the beginning. The slewing working pressure signal selects to close the confluence valve. During slewing operation, when the slewing working pressure reaches 2MPa, pressure sensor 1 opens, the solenoid valve is energized, and the control pressure pushes open the confluence valve, disconnecting the dual-pump confluence. When the main pump's working pressure reaches 16MPa, pressure sensor 2 opens, the solenoid valve is energized, and the control pressure pushes open the confluence valve, disconnecting the dual-pump confluence. When the main pump's working pressure is below 10MPa, pressure sensor 3 opens, the solenoid valve is de-energized, the confluence valve resets under spring force, and the dual pumps re-enter the flow. This scheme further complicates the electrical system, and the failure rate of the electrical components in a hydraulic system is higher than that of the hydraulic components. The hydraulic principle of direct confluence of the dual pumps leads to excess oil being unloaded under high pressure when the boom lowering and arm retraction movements do not require such a high flow rate, increasing heat generation. The three pressure sensors are integrated into the multi-way valve, and the wiring harness is also connected to the operator's cab, which is already small, further reducing operator comfort. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a compact flow distribution valve based on a truck-mounted crane dual-pump system that solves the problems of high system heat generation, lack of energy conservation and environmental protection, and safety hazards caused by engine stalling due to high pressure unloading of small pumps without the need for pressure sensors, solenoid valves and other electrical components.

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is: a compact flow distribution valve based on a truck-mounted crane dual-pump system, characterized in that: it includes...

[0006] The control valve has a P port, a P' port, and a T port. The P port is connected to the control oil circuit of the actuator, and the T port is connected to the return oil channel.

[0007] The relief valve is connected to the control valve and the return oil passage, respectively.

[0008] The confluence valve is connected to the small pump, the large pump, the P' port of the control valve, and the return oil passage, respectively. The confluence valve core operates based on the oil output state of the control valve P' port to realize the confluence and diversion of hydraulic oil pumped into the small pump and the large pump.

[0009] A check valve is provided on the oil line connecting the small pump and the confluence valve;

[0010] When the oil pressure entering the control valve does not exceed its overflow pressure, the control valve core actuates to open ports P and P'; when the oil pressure entering the control valve exceeds its overflow pressure, the control valve core actuates to open ports P' and T.

[0011] To better control the connection between the actuator and the control valve, a shuttle valve is also included. The inlet of the shuttle valve is connected to the oil circuit of the actuator, and the outlet of the shuttle valve is connected to the P port of the control valve through the oil circuit.

[0012] Preferably, the action execution mechanism includes a hoisting mechanism and a telescopic mechanism, and a shuttle valve is matched to each of the hoisting mechanism and the telescopic mechanism.

[0013] Preferably, a filter screen is provided in the oil line connecting the shuttle valve and the control valve.

[0014] With a smaller size and simplified piping and electrical component setup, the control valve, overflow valve, confluence valve, check valve, and shuttle valve are integrated into a single valve body.

[0015] Preferably, the valve body has a first flow channel extending in the left-right direction, the control valve core is disposed in the first flow channel, and the P port, P' port and T port are arranged sequentially from left to right. A spring acting on the control valve core is disposed at the right end of the first flow channel.

[0016] In order to achieve a smooth switching action of the control valve, limit the return oil flow of the relief valve, minimize the reduction of oil volume in the working channel, and improve working efficiency, a first damping hole and a second damping hole are provided at both ends of the first channel. The first damping hole and the second damping hole are respectively connected to the P port through an oil passage; the second damping hole is located near the spring and is connected to the inlet of the relief valve.

[0017] The cross-sectional area of ​​the first damping orifice is larger than that of the second damping orifice.

[0018] To ensure the smooth operation of the actuator, load-sensitive flow channels are connected between the confluence valve and the return oil channel, corresponding to the small pump and the large pump respectively, and damping channels are provided on the load-sensitive flow channels.

[0019] To adapt to different working conditions, the relief valve is a relief valve with adjustable set pressure.

[0020] Compared with existing technologies, the advantages of this utility model are as follows: The compact flow distribution valve based on the truck-mounted crane dual-pump system can realize the splitting and merging of small and large pumps, ensuring that the small pump can be unloaded at low pressure under heavy load conditions, avoiding excessive and rapid temperature rise, thus being more energy-efficient and environmentally friendly, and also avoiding the safety hazards caused by engine stalling. This compact flow distribution valve based on the truck-mounted crane dual-pump system does not require additional pressure sensors or solenoid valves, avoiding electrical failures during operation. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a compact flow distribution valve based on a truck-mounted crane dual-pump system in an embodiment of this utility model.

[0022] Figure 2 This is a longitudinal sectional view from the main perspective of the compact flow distribution valve based on the truck-mounted crane dual-pump system in this embodiment of the present invention.

[0023] Figure 3 This is a longitudinal cross-sectional view of the compact flow distribution valve based on the truck-mounted crane dual-pump system in an embodiment of this utility model.

[0024] Figure 4 This is a horizontal cross-sectional view of the compact flow distribution valve based on the truck-mounted crane dual-pump system in an embodiment of this utility model. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] The truck-mounted crane dual-pump system includes a winch mechanism, a telescopic mechanism, and other actuating mechanisms. As described in the background art, the truck-mounted crane dual-pump system includes a large pump 400 and a small pump 300. The truck-mounted crane dual-pump system works in conjunction with the compact flow distribution valve in this embodiment. During the initial operation of the winch mechanism and the telescopic mechanism, the large pump 400 and small pump 300 work together, driving the winch and telescopic mechanisms with a larger hydraulic action, increasing the operating speed and improving work efficiency. In the later stages of the operation, the small pump 300 needs to be diverted and stop working, leaving only the large pump 400 operating. This ensures smooth operation and prevents the small pump 300 from overheating due to excessive temperature rise, which affects efficiency and service life. It also solves the safety hazards of sudden engine shutdown during hoisting operations, such as rollover, boom breakage, and wire rope breakage.

[0027] like Figures 1 to 4As shown, the compact flow distribution valve based on the truck-mounted crane dual-pump system in this embodiment includes a control valve 1, an overflow valve 2, a confluence valve 3, and a shuttle valve 5. To reduce structural volume, improve integration, simplify piping structure, and enhance operational comfort, the control valve 1, overflow valve 2, confluence valve 3, and shuttle valve 5 share a single valve body 7. This means that the control valve 1, overflow valve 2, confluence valve 3, check valve 4, and shuttle valve 5 are integrated into one valve body 7. Specifically, a corresponding flow channel is provided within each valve body 7, and a valve core is installed within the corresponding flow channel, thus forming the aforementioned valves. A return oil channel 200 is provided within the valve body 7 to facilitate oil return from each valve.

[0028] For control valve 1, the valve body 7 has a first flow channel 11 extending in the left-right direction. Control valve core 12 is disposed within the first flow channel 11. Within the first flow channel 11, ports P, P', and T are sequentially arranged from left to right. Port P is connected to the control oil circuit 100 of the actuator, and port T is connected to the return oil channel 200. A spring 13 acting on control valve core 12 is disposed at the right end of the first flow channel 11. Initially, control valve 1 is connected to ports P and P', but not to port T. As oil enters through port P, and the oil pressure increases, the control valve core 12 overcomes the spring force of spring 13 and moves to the right, causing ports P' and T to connect, while port P is no longer connected.

[0029] The relief valve 2 is connected to the control valve 1 and the return oil passage 200, respectively. The relief valve 2 provides the oil pressure threshold for the switching action of the control valve 1. When the oil pressure entering the control valve 1 does not exceed its relief pressure, the control valve core 12 of the control valve 1 is activated to open the P port and the P' port; when the oil pressure entering the control valve 1 exceeds its relief pressure, the control valve core 12 of the control valve 1 is activated to open the P' port and the T port.

[0030] The overflow valve 2 is located within the extended channel of the first flow channel 11, and is positioned close to the spring 13. The overflow valve 2 has a set overflow pressure threshold. When the oil pressure entering the control valve 1 exceeds this threshold, the overflow valve 2 opens, allowing the oil to overcome the spring force of the spring 13 and return through ports P' and T. Simultaneously, the oil also returns through the overflow valve 2. To facilitate adaptation to different truck-mounted crane dual-pump systems, the overflow valve 2 in this embodiment is a pressure-adjustable overflow valve.

[0031] As described in the background art, the unloaded oil is the working flow channel oil. To ensure the smooth switching action of control valve 1 and limit the return flow of relief valve 2, thereby minimizing the reduction in the amount of oil in the working flow channel and improving working efficiency, the first flow channel 11 is provided with a first damping orifice 111 and a second damping orifice 112 at both ends. The first damping orifice 111 and the second damping orifice 112 are respectively connected to port P through an oil passage. The second damping orifice 112 is located near spring 13 and is connected to the inlet of relief valve 2. The cross-sectional area of ​​the first damping orifice 111 is larger than that of the second damping orifice 112. Based on the limitation of the cross-sectional area of ​​the two damping orifices, it is possible to ensure that the oil flows smoothly along the normal flow path, avoiding sudden changes in flow rate, and also to effectively limit the return flow of the oil.

[0032] The confluence valve 3 is connected to the small pump 300, the large pump 400, the P' port of control valve 1, and the return oil passage 200. The confluence valve core of the confluence valve 3 operates based on the oil output state of the P' port of control valve 1, opening and closing accordingly. That is, when control valve 1 is in the state where the P port and P' port are connected, the confluence valve 3 is open when oil is output to the confluence valve 3 through the P' port. When control valve 1 is in the state where the P' port and T port are connected, the P' port no longer outputs oil to the confluence valve 3, and the confluence valve 3 is closed. When the confluence valve 3 is open, the hydraulic oil pumped into the small pump 300 and the large pump 400 is combined. When the confluence valve 3 is closed, the hydraulic oil pumped into the small pump 300 and the large pump 400 is no longer connected, and the small pump 300 can achieve low-pressure unloading.

[0033] In order to effectively realize the merging of small pump 300 and large pump 400, a one-way valve 4 is provided on the oil line connecting small pump 300 and merging valve 3.

[0034] Shuttle valve 5 is used to better control the connection between the actuator and control valve 1. The inlet of shuttle valve 5 is connected to the oil circuit of the actuator, and the outlet of shuttle valve 5 is connected to port P of control valve 1 via an oil circuit. The number of shuttle valves 5 is determined according to the number of actuators. The actuators include a hoisting mechanism and a telescopic mechanism, and one shuttle valve 5 is matched to each hoisting mechanism and telescopic mechanism. When the actuators such as the hoisting mechanism and the telescopic mechanism need to perform corresponding actions, the actuators will output control signal pressure oil to shuttle valve 5. The control signal pressure oil enters control valve 1 through shuttle valve 5, thereby realizing the action of control valve 1.

[0035] In addition, to improve the reliability of the compact flow distribution valve of the truck crane dual pump system, a filter screen 6 is installed on the oil line connecting the shuttle valve 5 and the control valve 1.

[0036] To ensure the smooth operation of the actuators, load-sensitive flow channels 31 are connected between the confluence valve 3 and the return oil channel 200, corresponding to the small pump 300 and the large pump 400 respectively. A damping orifice 500 is provided on the load-sensitive flow channel 31. Based on the cooperation of the load-sensitive flow channel 31 and the damping orifice 500, pressure vibration in the load-sensitive flow channel 31 can be resolved, making the operation of each actuator smoother. It also solves the problem of slow pressure release after the actuators have finished operating, thus addressing the issue of increased heat generation during unloading of the dual pumps due to slow pressure release and reducing energy consumption.

[0037] The working process of the compact flow distribution valve based on the truck crane dual pump system is as follows: When hoisting or telescopic work is required, the truck crane dual pump system will control the corresponding actuator to output control signal pressure oil. The control signal pressure oil passes through the shuttle valve 5 and the filter screen and enters the control valve 1. In the early stage, the oil pressure entering the control valve 1 is less than the oil pressure threshold of the relief valve 2. The P port and P' port in the corresponding control valve 1 are in the conducting state, that is, the control valve 1 is in the conducting state. The oil is output through the P' port of the control valve 1 to the confluence valve 3. This oil then flows back to the return oil channel 200 for circulation. The valve core of the confluence valve 3 actuates under the action of the oil entering it, thus opening the confluence valve 3. Since the hydraulic oil channels of the small pump 300 and the large pump 400 are connected to the main channel in the confluence valve 3, the small pump 300 and the large pump 400 work simultaneously. The hydraulic oil in the small pump 300 flows through the open confluence valve 3 to the supply channel of the large pump 400 for each actuator, thereby achieving the merging of the hydraulic oil from the small pump 300 and the large pump 400. This combined action on the actuator ensures that the actuator can start quickly and accelerate its movement, improving work efficiency. As the control signal pressure oil continuously enters, the oil pressure in the control valve 1 continuously rises. When it reaches the sum of the overflow pressure threshold of the relief valve 2 and the spring force of the spring 13, the control valve core 12 actuates, thereby opening port P' and port T. At this time, port P is closed, and control valve 1 is shut off. The oil flows back from port T and relief valve 2 to the return oil channel 200. No new oil enters the corresponding confluence valve 3, so valve 3 closes, and the confluence between the small pump 300 and the large pump 400 is broken. At this time, the small pump 300 can perform low-pressure unloading and no longer works, avoiding heat generation during operation. The hydraulic oil output by the large pump 400 acts on the actuator, ensuring that the actuator works smoothly at a lower speed.

[0038] This utility model discloses a compact flow distribution valve based on a truck-mounted crane dual-pump system. Within this valve, the flow can be split and combined between the small pump 300 and the large pump 400. This ensures that under heavy load conditions, the small pump 300 can be unloaded at low pressure, preventing excessive and rapid temperature rise, thus achieving greater energy efficiency and environmental friendliness. It also avoids the safety hazards caused by engine stalling. This compact flow distribution valve based on the truck-mounted crane dual-pump system eliminates the need for additional pressure sensors and solenoid valves, avoiding electrical malfunctions during operation.

[0039] In the specification and claims of this utility model, terms indicating direction, such as "front," "rear," "upper," "lower," "left," "right," "side," "top," and "bottom," are used to describe various exemplary structural parts and elements of this utility model. However, the use of these terms is merely for the purpose of explanation and is based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this utility model can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

Claims

1. A compact flow distribution valve based on a dual pump system of a truck-mounted crane, characterized in that: include The control valve (1) has a P port, a P' port and a T port. The P port is connected to the control oil circuit (100) of the actuator and the T port is connected to the return oil channel (200). The overflow valve (2) is connected to the control valve (1) and the return oil passage (200) respectively; The confluence valve (3) is connected to the small pump (300), the large pump (400), the P' port of the control valve (1), and the return oil channel (200), respectively. The confluence valve core of the confluence valve (3) operates based on the oil output state of the P' port of the control valve (1) to realize the confluence and diversion of the hydraulic oil pumped into the small pump (300) and the large pump (400); A check valve (4) is provided on the oil line connecting the small pump (300) and the confluence valve (3); When the oil pressure entering the control valve (1) does not exceed its overflow pressure, the control valve core (12) of the control valve (1) is activated to open port P and port P'; when the oil pressure entering the control valve (1) exceeds its overflow pressure, the control valve core (12) of the control valve (1) is activated to open port P' and port T.

2. The compact flow distribution valve for a dual pump system of a truck-mounted crane according to claim 1, characterized in that: It also includes a shuttle valve (5), the inlet of which is connected to the oil circuit of the actuator, and the outlet of which is connected to the P port of the control valve (1) through the oil circuit.

3. The compact flow distribution valve for a dual pump system of a truck-mounted crane according to claim 2, characterized in that: The actuator includes a hoisting mechanism and a telescopic mechanism, and a shuttle valve (5) is matched to the hoisting mechanism and the telescopic mechanism respectively.

4. The compact flow distribution valve for a dual pump system of a truck-mounted crane according to claim 2, characterized in that: A filter screen (6) is installed on the oil line connecting the shuttle valve (5) and the control valve (1).

5. A compact flow distribution valve for a dual pump system of a truck-mounted crane according to any one of claims 2 to 4, characterized in that: The control valve (1), overflow valve (2), confluence valve (3), check valve (4), and shuttle valve (5) are integrated into a valve body (7).

6. The compact flow distribution valve for a dual pump system of a truck-mounted crane according to claim 5, characterized in that: The valve body (7) is provided with a first flow channel (11) extending in the left and right direction. The control valve core (12) is located in the first flow channel (11). The P port, P' port and T port are arranged sequentially from left to right. A spring (13) acting on the control valve core (12) is provided at the right end of the first flow channel (11).

7. The compact flow distribution valve for a dual pump system of a truck-mounted crane according to claim 6, characterized in that: The first flow channel (11) has a first damping hole (111) and a second damping hole (112) at both ends. The first damping hole (111) and the second damping hole (112) are respectively connected to the P port through an oil passage. The second damping hole (112) is located near the spring (13) and is connected to the inlet of the overflow valve (2). The cross-sectional area of ​​the first damping hole (111) is greater than the cross-sectional area of ​​the second damping hole (112).

8. A compact flow distribution valve for a dual pump system of a truck-mounted crane according to any one of claims 1 to 4, characterized in that: The confluence valve (3) and the return oil channel (200) are respectively connected to load-sensitive flow channels (31) corresponding to the small pump (300) and the large pump (400), and the load-sensitive flow channels (31) are provided with damping channels (500).

9. A compact flow distribution valve for a dual pump system of a truck-mounted crane according to any one of claims 1 to 4, characterized in that: The relief valve (2) is a relief valve with adjustable set pressure.

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