Hydraulic system with speed regulation mode switching function and engineering machine thereof

Abstract

The application discloses a hydraulic system with a speed regulation mode switching function and engineering machinery thereof, and relates to the technical field of hydraulic systems.The hydraulic system comprises a load-sensitive pump and a speed regulation mode switching valve group.The speed regulation mode switching valve group comprises a check valve, a hydraulic control reversing valve, an electric proportional relief valve and a throttling damper.The check valve functions to prevent high-pressure oil from flowing back.The hydraulic system with the speed regulation mode switching function and the engineering machinery thereof are characterized in that the system automatically switches through the speed regulation mode switching valve group during system operation, and the system is preferentially switched to a load-sensitive speed regulation mode.In the load-sensitive speed regulation mode, multiple actions can be realized in a coordinated manner.When the load-sensitive valve group does not function, the speed regulation mode of the hydraulic system is switched to a constant-pressure speed regulation mode, so that in different valve groups and different working conditions, only one oil pump is provided in the system, and the system can be compatible with two speed regulation modes, compact space arrangement is realized, cost is reduced, and multiple actions can be realized in a composite manner.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic systems, in particular to a hydraulic system with speed regulation mode switching function and engineering machinery. BACKGROUND

[0002] In the design process of engineering machinery, as the whole machine design is more and more compact, the layout of the hydraulic system is also more and more compact. If the reuse of the oil pump can be realized as much as possible, the installation space can be greatly saved, and the cost of the whole machine hydraulic system can be reduced. In the design of engineering machinery hydraulic system, the load sensing system can output corresponding flow according to the flow demand of the load, can save energy, and can also realize the rigid maintenance of the load speed at a certain level. It is widely used in mobile hydraulic systems. However, the load sensing pump often needs to be matched with a load sensing valve to play a role. If there is a switch valve system in the whole hydraulic system, the speed regulation modes of the two systems are quite different, and the two speed regulation systems cannot be considered. The general method is to select two pumps, one uses a load sensing pump, and the other uses a constant flow pump system or an electric proportional pump to realize speed regulation. However, in some compact engineering machinery, there is no extra space to arrange two oil pumps. How to realize the function of two pumps in one pump space has become a problem that engineering and technical personnel in this field need to solve. SUMMARY

[0003] In view of the deficiencies of the prior art, the present application provides a hydraulic system with speed regulation mode switching function and engineering machinery, which solves the problems raised in the background art.

[0004] To achieve the above purpose, the present application realizes the following technical scheme: a hydraulic system with speed regulation mode switching function, comprising a load sensing pump and a speed regulation mode switching valve group, the speed regulation mode switching valve group comprising a check valve, a hydraulic control reversing valve, an electric proportional relief valve and a throttling damper.

[0005] The check valve prevents high-pressure oil from flowing back. The control oil port A1 of the hydraulic control reversing valve is connected to the load feedback oil circuit of the load sensing valve group, and the control oil port B1 of the hydraulic control reversing valve is connected to the switch valve working oil circuit. The control oil port B2 of the hydraulic control reversing valve is connected to the load sensing valve working oil circuit, and the hydraulic control reversing valve is connected to the pump feedback oil circuit of the load sensing pump through the throttling damper. The pump feedback oil circuit is connected in parallel with the electric proportional relief valve. The switch valve working oil circuit is connected with a switch valve group.

[0006] Further, the inlet and outlet of the check valve, the hydraulic control reversing valve, the load sensing valve group, the electric proportional relief valve and the switch valve group are provided with ports, and the inside of the port is threadedly connected with a connecting end.

[0007] Further, the side surface of the connecting end is rotationally connected with a pipeline, and the pipeline is the load feedback oil circuit, the switch valve working oil circuit, the load sensitive valve working oil circuit or the pump feedback oil circuit.

[0008] Further, the outer wall of the pipeline is fixed with a ring plate seat, and the two sides of the ring plate seat are rotationally connected with connecting buckles.

[0009] Further, the two sides of one end of the port close to the connecting end are fixed with micro oil pipes, and the piston rod is arranged in the micro oil pipes.

[0010] Further, the end of the piston rod is fixed with a ring-shaped sliding plate, and the ring-shaped sliding plate is sleeved on the outer wall of the port.

[0011] Further, the two sides of the ring-shaped sliding plate are fixed with connecting hooks, and the connecting hooks are hookingly connected with the connecting buckles.

[0012] Further, the outer wall of one end of the micro oil pipe away from the ring-shaped sliding plate is connected with first and second sealing pads through micro pipes, and the first and second sealing pads are both hollow structures.

[0013] Further, the first sealing pad is fixed in the port, and the second sealing pad is fixed on the side surface of the port, and the second sealing pad is located between the connecting end and the port.

[0014] An engineering machine, the engineering machine is applied with the hydraulic system with the speed regulation mode switching function.

[0015] The hydraulic system with the speed regulation mode switching function and the engineering machine thereof have the following beneficial effects:

[0016] 1. The hydraulic system with the speed regulation mode switching function and the engineering machine thereof only need to use one load sensitive pump in the system, and the automatic switching of the speed regulation mode switching valve group in the system running process is realized, so that when the load sensitive valve group works, the system is preferentially switched to the load sensitive speed regulation mode, and in the load sensitive speed regulation mode, the multi-action cooperative action can be realized; when the load sensitive valve group does not work, the speed regulation mode of the hydraulic system is switched to the constant pressure speed regulation, so that under different valve groups and different working conditions, only one pump, i.e. the load sensitive pump, of one system can be compatible with two speed regulation modes, the compact space arrangement is realized while the cost is reduced, and the multi-action composite action can be realized.

[0017] 2. The hydraulic system with the speed regulation mode switching function and the engineering machinery, after each pipeline is connected with each valve body through the threaded connection of the connection end head and the port, the connection buckle and the connection hook are firmly hooked to improve the stability of the threaded connection of the connection end head and the port of each valve body, the threaded connection of the connection end head and the port is prevented from loosening by the hooking of the connection buckle and the connection hook, so that the loosening or falling off of each pipeline and each valve body is prevented, and the piston rod is retracted to push the oil flow in the micro oil pipeline, so that the oil flows into the first sealing pad and the second sealing pad to make them bulge, thereby filling the gap between the connection end head and the port, and improving the sealing performance after the connection of the pipeline and the valve body. BRIEF DESCRIPTION OF DRAWINGS

[0018] Fig. 1 The schematic diagram of the overall oil circuit of the present application is shown in the figure.

[0019] Fig. 2 The schematic diagram of the speed regulation mode switching valve group of the present application is shown in the figure.

[0020] Fig. 3 The schematic diagram of the structure after the threaded connection of the port and the connection end head of the present application is shown in the figure.

[0021] Fig. 4 The schematic diagram of the structure of the connection end head of the present application is shown in the figure.

[0022] Fig. 5 The schematic diagram of the structure of the port of the present application is shown in the figure.

[0023] Fig. 6 The schematic diagram of the structure after the separation of the annular slide plate of the present application is shown in the figure.

[0024] In the figure: 1, load sensitive pump; 11, load feedback oil circuit; 12, on-off valve working oil circuit; 13, load sensitive valve working oil circuit; 14, pump feedback oil circuit; 2, speed regulation mode switching valve group; 21, one-way valve; 22, hydraulic control reversing valve; 23, electric proportional overflow valve; 24, throttling damping; 3, on-off valve group; 4, load sensitive valve group; 5, port; 51, micro oil pipeline; 52, piston rod; 53, annular slide plate; 54, connection hook; 6, connection end head; 61, ring plate seat; 62, connection buckle; 7, first sealing pad; 8, second sealing pad. DETAILED DESCRIPTION

[0025] The embodiments of the present application will be further described in detail below in combination with the drawings and examples. The following examples are used to illustrate the present application, but cannot be used to limit the scope of the present application.

[0026] As Figs. 1-2As shown, the present invention provides a technical solution: a hydraulic system with speed regulation mode switching function, including a load-sensitive pump 1 and a speed regulation mode switching valve group 2, the speed regulation mode switching valve group 2 including a check valve 21, a hydraulically controlled directional valve 22, an electro-proportional relief valve 23 and a throttling damper 24.

[0027] The function of the one-way valve 21 is to prevent high-pressure oil backflow. The control port A1 of the hydraulic directional valve 22 is connected to the load feedback oil circuit 11 of the load-sensitive valve group 4, and the control port B1 of the hydraulic directional valve 22 is connected to the working oil circuit 12 of the switching valve. The control port B2 of the hydraulic directional valve 22 is connected to the working oil circuit 13 of the load-sensitive valve, and the hydraulic directional valve 22 is connected to the pump feedback oil circuit 14 of the load-sensitive pump 1 through the throttling damper 24. The pump feedback oil circuit 14 is connected in parallel with the electro-proportional relief valve 23. The working oil circuit 12 of the switching valve is connected to the switching valve group 3.

[0028] The specific operation is as follows: When the system's standby pressure setting value for the proportional relief valve 23 is greater than the switching pressure of the hydraulic directional valve 22, after the load-sensitive valve group 4 switches, the LS signal of the load-sensitive valve group 4 will cause the hydraulic directional valve 22 to switch. The load feedback oil circuit 11 is connected to the pump feedback oil circuit 14. The displacement control of the load-sensitive pump 1 is controlled by the load pressure signal, and the flow output is supplied according to the demand of the load-sensitive valve group 4, thereby achieving energy saving and speed regulation. If the load-sensitive valve group 4 does not switch, the pressure in the load feedback oil circuit 11 of the load-sensitive valve group 4 is 0, and the hydraulic... The oil port B1 of the directional control valve 22 is connected to the pump feedback oil circuit 14. The load-sensitive pump 1 is in constant pressure pump mode, and the flow regulation mode is to automatically output flow to achieve constant pressure. At this time, if the switching valve group 3 switches and there is a flow demand, the load-sensitive pump 1 is in constant pressure flow mode. When the pressure set by the electro-proportional relief valve 23 is greater than the load pressure, the oil pump is in full displacement working mode, thereby maximizing the flow demand of the switching valve system. When the set pressure is equal to the load pressure, the oil pump is in constant pressure mode, and the displacement is in a dynamic state, thereby achieving energy saving of the switching valve system.

[0029] Based on the above description, the present invention only requires one load-sensitive pump 1 in the system. By automatically switching the speed regulation mode switching valve group 2 during system operation, the system can preferentially switch to the load-sensitive speed regulation mode when the load-sensitive valve group 4 is active. In the load-sensitive speed regulation mode, multiple actions can be coordinated. When the load-sensitive valve group 4 is not active, the speed regulation mode of the hydraulic system switches to constant pressure speed regulation. Thus, under different valve groups and different working conditions, a single oil pump, namely the load-sensitive pump 1, can be compatible with two speed regulation modes, achieving a compact space layout while reducing costs. It can also realize multi-action compound actions.

[0030] like Figs. 1-6As shown, the inlet and outlet ends of the one-way valve 21, the hydraulic directional valve 22, the load-sensitive valve group 4, the electro-proportional relief valve 23, and the switching valve group 3 are all equipped with ports 5, and the internal threads of the ports 5 are connected to the connecting end 6. The side of the connecting end 6 is rotatably connected to a pipeline, which is the load feedback oil circuit 11, the switching valve working oil circuit 12, the load-sensitive valve working oil circuit 13, or the pump feedback oil circuit 14. The outer wall of the pipeline is fixed with a ring plate seat 61, and the two sides of the ring plate seat 61 are rotatably connected to the connecting buckles 62. The ends of the ports 5 near the connecting end 6 are fixed with miniature oil pipes 51, and the miniature oil pipes 51 are... A piston rod 52 is inserted inside, and an annular slide plate 53 is fixed to the end of the piston rod 52. The annular slide plate 53 is sleeved on the outer wall of the port 5. Connecting hooks 54 are fixed on both sides of the annular slide plate 53, and the connecting hooks 54 are hooked and connected to the connecting buckle 62. The outer wall of the end of the micro oil pipe 51 away from the annular slide plate 53 is connected to a first sealing gasket 7 and a second sealing gasket 8 through a micro pipe. The first sealing gasket 7 and the second sealing gasket 8 are both hollow structures. The first sealing gasket 7 is fixed inside the port 5, and the second sealing gasket 8 is fixed on the side of the port 5. The second sealing gasket 8 is located between the connecting end 6 and the port 5.

[0031] The specific operation is as follows: when the port 5 of each valve body is connected to the corresponding pipeline, the connecting end 6 at the end of each pipeline is screwed into the port 5 by rotation to achieve a threaded connection. Then, the annular slide plate 53 is pushed to slide, so that the piston rod 52 is pressed into the micro oil pipe 51, so that the connecting hooks 54 on both sides of the annular slide plate 53 extend towards the pipeline. Then, the connecting buckle 62 is pushed to rotate and hook with the connecting hook 54, thereby preventing the connecting end 6 and the port 5 from loosening after the threaded connection.

[0032] During the process of the connecting buckle 62 and the connecting hook 54 being firmly connected, the piston rod 52 retracts into the micro oil tube 51, thereby pushing the oil inside the micro oil tube 51 to flow. This causes the oil to flow into the first sealing gasket 7 and the second sealing gasket 8 along the micro tube, causing the first sealing gasket 7 and the second sealing gasket 8 to bulge. This allows the first sealing gasket 7 to fill the gap between the outer wall of the connecting end 6 and the inner wall of the port 5, while the second sealing gasket 8 fills the gap between the outer wall of the connecting end 6 and the side of the port 5.

[0033] Based on the above description, after each pipeline is threadedly connected to the port 5 of each valve body via the connecting end 6, the present invention uses the connecting buckle 62 and the connecting hook 54 to firmly hook together, thereby improving the stability of the threaded connection between the connecting end 6 and the port 5 of each valve body. Since the connecting buckle 62 and the connecting hook 54 are hooked together to prevent the threaded connection between the connecting end 6 and the port 5 from loosening, the connection between each pipeline and each valve body is prevented from becoming loose or falling off. Moreover, by using the connecting buckle 62 and the connecting hook 54 to hook together, the piston rod 52 retracts and pushes the oil inside the micro oil pipe 51 to flow, so that the oil flows into the first sealing gasket 7 and the second sealing gasket 8 along the micro pipe to make them bulge, thereby filling the gap between the connecting end 6 and the port 5, thereby improving the sealing performance after the pipeline and the valve body are connected.

[0034] An engineering machine that uses the aforementioned hydraulic system with speed regulation mode switching function.

[0035] In summary, this hydraulic system and its associated engineering machinery with speed regulation mode switching function operate as follows: First, the system's standby pressure setting value, applied to the electro-proportional relief valve 23, exceeds the switching pressure of the hydraulic directional valve 22. After the load-sensitive valve group 4 switches, the LS signal of the load-sensitive valve group 4 causes the hydraulic directional valve 22 to switch. The load feedback oil circuit 11 is connected to the pump feedback oil circuit 14. The displacement control of the load-sensitive pump 1 is controlled by the load pressure signal, and the flow output is supplied according to the demand of the load-sensitive valve group 4, thereby achieving energy saving and speed regulation. If the load-sensitive valve group 4 does not switch, the load of the load-sensitive valve group 4... When the pressure of feedback oil circuit 11 is 0, the oil port B1 of hydraulic control directional valve 22 is connected to pump feedback oil circuit 14. Load-sensitive pump 1 is in constant pressure pump mode, and the flow regulation mode is to automatically output flow to achieve constant pressure. At this time, if the switching valve group 3 switches and there is a flow demand, the load-sensitive pump 1 is in constant pressure flow mode. When the pressure set by electro-proportional relief valve 23 is greater than the load pressure, the oil pump is in full displacement working mode, thereby maximizing the flow demand of the switching valve system. When the set pressure is equal to the load pressure, the oil pump is in constant pressure mode, and the displacement is in a dynamic state, thereby achieving energy saving of the switching valve system.

[0036] When the port 5 of each valve body is connected to the corresponding pipeline, the connecting end 6 at the end of each pipeline is screwed into the port 5 by rotation to achieve a threaded connection. Then, the annular slide plate 53 is pushed to slide, so that the piston rod 52 is pressed into the micro oil pipe 51. The connecting hooks 54 on both sides of the annular slide plate 53 extend towards the pipeline. Then, the connecting buckle 62 is pushed to rotate and hook with the connecting hook 54. This can prevent the connecting end 6 and the port 5 from loosening after the threaded connection.

[0037] During the process of the connecting buckle 62 and the connecting hook 54 being firmly connected, the piston rod 52 retracts into the micro oil tube 51, thereby pushing the oil inside the micro oil tube 51 to flow. This causes the oil to flow into the first sealing gasket 7 and the second sealing gasket 8 along the micro tube, causing the first sealing gasket 7 and the second sealing gasket 8 to bulge. The first sealing gasket 7 fills the gap between the outer wall of the connecting end 6 and the inner wall of the port 5, while the second sealing gasket 8 fills the gap between the outer wall of the connecting end 6 and the side of the port 5.

[0038] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A hydraulic system with speed regulation mode switching function, comprising a load-sensitive pump (1) and a speed regulation mode switching valve group (2), characterized in that: The speed regulation mode switching valve group (2) includes a check valve (21), a hydraulic directional valve (22), an electro-proportional relief valve (23), and a throttling damper (24). The function of the one-way valve (21) is to prevent high-pressure oil backflow. The inlet of the one-way valve (21) is connected to the P port of the speed regulation mode switching valve group (2). The outlet of the one-way valve (21) is connected to the oil port B1 and the oil port B2 of the hydraulic directional valve (22). The oil port A1 of the hydraulic directional valve (22) is connected to the load feedback oil circuit (11) of the load sensitive valve group (4). The oil port B1 of the hydraulic directional valve (22) is connected to the working oil circuit (12) of the switch valve. The oil port B2 of the hydraulic directional valve (22) is connected to the working oil circuit (13) of the load sensitive valve. The hydraulic directional valve (22) is connected to the pump feedback oil circuit (14) of the load sensitive pump (1) through the throttling damper (24). The pump feedback oil circuit (14) is connected in parallel with the electro-proportional relief valve (23). The working oil circuit (12) of the switch valve is connected to the switch valve group (3).

2. A hydraulic system with speed regulation mode switching function according to claim 1, characterized in that: The inlet and outlet ends of the one-way valve (21), the hydraulic control directional valve (22), the load-sensitive valve group (4), the electro-proportional relief valve (23), and the switch valve group (3) are all provided with ports (5), and the internal threads of the ports (5) are connected to the connecting end (6).

3. A hydraulic system with speed regulation mode switching function according to claim 2, characterized in that: The side of the connecting end (6) is rotatably connected to a pipeline, which is the load feedback oil circuit (11), the switching valve working oil circuit (12), the load sensitive valve working oil circuit (13), or the pump feedback oil circuit (14).

4. A hydraulic system with speed regulation mode switching function according to claim 3, characterized in that: The outer wall of the pipeline is fixed with a ring plate seat (61), and the two sides of the ring plate seat (61) are rotatably connected with connecting buckles (62).

5. A hydraulic system with speed regulation mode switching function according to claim 4, characterized in that: The port (5) is fixed with micro oil pipes (51) on both sides near the connection end (6), and a piston rod (52) is inserted inside the micro oil pipes (51).

6. A hydraulic system with speed regulation mode switching function according to claim 5, characterized in that: The piston rod (52) has an annular sliding plate (53) fixed to its end, and the annular sliding plate (53) is sleeved on the outer wall of the port (5).

7. A hydraulic system with speed regulation mode switching function according to claim 6, characterized in that: The two sides of the annular slide plate (53) are fixed with connecting hooks (54), and the connecting hooks (54) are hooked and connected to the connecting buckle (62).

8. A hydraulic system with speed regulation mode switching function according to claim 7, characterized in that: The outer wall of the end of the micro oil pipe (51) away from the annular slide plate (53) is connected to a first sealing gasket (7) and a second sealing gasket (8) through a micro pipe, and both the first sealing gasket (7) and the second sealing gasket (8) are hollow structures.

9. A hydraulic system with speed regulation mode switching function according to claim 8, characterized in that: The first sealing gasket (7) is fixed inside the port (5), the second sealing gasket (8) is fixed on the side of the port (5), and the second sealing gasket (8) is located between the connecting end (6) and the port (5).

10. An engineering machinery, characterized in that: The engineering machinery application includes a hydraulic system with speed regulation mode switching function as described in any one of claims 1-9.

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