Hydraulic control system, work device and working machine

Abstract

This utility model discloses a hydraulic control system, working device, and engineering machinery, including a speed-increasing valve, a shuttle valve, and a hydraulically controlled directional valve, all composed of a balance valve and a hydraulically controlled check valve. The speed-increasing valve includes ports A1, B1, A, and B. Port B1 is connected to the large chamber of the hydraulic cylinder, and port A1 is connected to the small chamber of the hydraulic cylinder. The inlet of the hydraulically controlled directional valve is connected to port A1, and its outlet is connected to the first inlet of the shuttle valve. The control port of the hydraulically controlled directional valve is connected to port B. When a preset pressure oil flows into the control port, the hydraulically controlled directional valve shifts and disconnects its inlet and outlet. The second inlet of the shuttle valve is connected to the outlet of the balance valve, and its outlet is connected to the control port of the hydraulically controlled check valve. When a preset pressure oil flows into the control port, the hydraulically controlled check valve remains closed. This utility model achieves the pressure-holding function of the small chamber of the hydraulic cylinder, preventing the upper tool from falling independently, and also achieves the speed-increasing function.

Description

Technical Field

[0001] This utility model relates to a hydraulic control system, which is mainly used in the hydraulic control system of shearing shears for excavator attachments, and belongs to the field of excavator hydraulic systems. Background Technology

[0002] Eagle beak shears are widely used in the demolition of abandoned steel structures. During transportation and blade replacement, the jaws must be kept fully open. However, existing eagle beak shears exhibit a phenomenon where the jaws automatically close when the machine is stopped, posing a certain safety hazard.

[0003] Existing eagle-beak shears cannot maintain a constant jaw opening when the machine is stopped; some manufacturers improve the pressure holding capacity of the small chamber of the hydraulic cylinder by increasing the spring stiffness of the hydraulic control check valve inside the speed-increasing valve.

[0004] Increasing the spring stiffness of the pilot-operated check valve can alleviate the problem of blades falling off on their own to some extent. However, when the upper blade is subjected to a large external impact, the jaws still close, so it cannot fundamentally solve the problem. In addition, increasing the spring stiffness will increase the pressure loss of the pilot-operated check valve in the forward direction, reducing the oil regeneration efficiency during shearing. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this utility model provides a hydraulic control system for shearing and pliers-type tools, which utilizes the selectivity of the shuttle valve to achieve the pressure-holding function of the small chamber of the cylinder under specific working conditions.

[0006] This utility model is achieved according to the following technical solution:

[0007] Firstly, this utility model provides a hydraulic control system, mainly used in shearing and pliers, including a speed-increasing valve composed of a balance valve and a hydraulic control check valve. The speed-increasing valve includes an A1 port, a B1 port, an A port, and a B port. The B1 port is connected to the large chamber of the cylinder, and the A1 port is connected to the small chamber of the cylinder.

[0008] It also includes a shuttle valve and a hydraulically controlled directional valve; the inlet of the hydraulically controlled directional valve is connected to port A1, the outlet of the hydraulically controlled directional valve is connected to the first inlet of the shuttle valve, and the control port of the hydraulically controlled directional valve is connected to port B. When a preset pressure oil flows into the control port, the hydraulically controlled directional valve shifts and disconnects its inlet and outlet; the second inlet of the shuttle valve is connected to the outlet of the balance valve, and the outlet of the shuttle valve is connected to the control port of the hydraulically controlled check valve. When a preset pressure oil flows into the control port, the hydraulically controlled check valve is always in the closed state.

[0009] In some embodiments, the inlet of the hydraulic check valve is connected to port A1, and the outlet of the hydraulic check valve is connected to port B1.

[0010] In some embodiments, the oil inlet of the balance valve is connected to the A1 oil port, the oil outlet of the balance valve is connected to the A oil port, and the control port of the balance valve is connected to the B1 oil port. When a preset pressure oil flows into the control port, the balance valve opens to connect the oil inlet and the oil outlet.

[0011] In some embodiments, the balance valve is further provided with a bypass check valve, the oil inlet of which is connected to oil port A, and the oil outlet of which is connected to oil port A1.

[0012] In some embodiments, a throttling orifice is provided in the oil passage between the control port and the B port of the hydraulic directional valve.

[0013] Secondly, this utility model provides a working device, including a boom, stick, and shear-like implement connected together, wherein the hydraulic cylinder of the shear-like implement is equipped with the aforementioned hydraulic control system.

[0014] In some embodiments, the pliers include scissors.

[0015] Thirdly, this utility model provides an engineering machine that includes the aforementioned hydraulic control system; or, includes the aforementioned working device.

[0016] In some embodiments, the construction machinery includes an excavator.

[0017] The beneficial effects of this utility model are:

[0018] 1. It achieves the pressure-holding function of the small chamber of the hydraulic cylinder, preventing the upper blade from falling down on its own;

[0019] 2. While ensuring the above functions, the speed-up function was implemented. Attached Figure Description

[0020] The accompanying drawings, as part of this utility model, are used to provide a further understanding of the present utility model. The illustrative embodiments and descriptions of the present utility model are used to explain the present utility model, but do not constitute an undue limitation of the present utility model. Obviously, the drawings described below are merely some embodiments; those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0021] In the attached diagram:

[0022] Figure 1 The schematic diagram of an existing speed-increasing valve is shown.

[0023] Figure 2 This is a schematic diagram of a hydraulic control system according to the present invention.

[0024] Attached diagram labels: 100-balance valve, 200-piston check valve, 300-piston directional valve, 400-shuttle valve.

[0025] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0027] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0028] Figure 1 The schematic diagram of the speed-increasing valve in the prior art is given, and its working process is as follows.

[0029] The large chamber of the eagle-beak shear cylinder is connected to port B1, and the small chamber is connected to port A1. Ports A and B are directly connected to the directional valve. Initially, the small chamber of the cylinder is full of oil, the large chamber is empty, and the jaws are fully open.

[0030] During the jaw closing process, the movement of the hydraulic cylinder is divided into two stages: acceleration and shearing.

[0031] In the first stage, the blade does not cut the object. The oil from the main valve flows through port B of the speed-increasing valve to port B1 and then enters the large chamber of the cylinder, pushing the piston out. At this time, since the object is not cut, the pressure in the large chamber of the cylinder is low, which causes the balance valve to fail to open. Therefore, the oil in the small chamber enters the large chamber of the cylinder through the hydraulic control check valve to achieve the speed-increasing function.

[0032] In the second stage, when the blade cuts into the object, the pressure in the large chamber of the oil cylinder rises, causing the pressure acting on port 3 of the balance valve to rise synchronously. When the pressure is higher than the spring force of the balance valve, the balance valve opens, and the oil in the small chamber of the oil cylinder enters the speed-increasing valve through port A1 and then flows directly back to port A through the balance valve. At this time, the hydraulic control check valve stops at ports 1 and 2, stopping the speed-increasing function.

[0033] During the opening of the jaws, the high pressure at port A acts on port 3 of the hydraulic control check valve, forcing the hydraulic control check valve to be in the closed state. The oil enters the small chamber of the oil cylinder through the bypass check valve in the balance valve, pushing the piston to retract.

[0034] When the machine needs to be transported or the blades replaced, the blade edge must be kept fully open. In this state, the large chamber of the hydraulic cylinder is fully compressed, and the small chamber of the hydraulic cylinder is filled with oil. At this time, the hydraulic control check valve can freely open in one direction from port 1 to port 2, and the small chamber of the hydraulic cylinder cannot maintain pressure, causing the blade to fall down on its own.

[0035] To address this problem, this utility model provides a hydraulic control system, such as... Figure 2 As shown, the system includes a speed-increasing valve (composed of a balance valve 100 and a hydraulically controlled check valve 200), a shuttle valve 400, and a hydraulically controlled directional valve 300. The speed-increasing valve includes ports A1, B1, A, and B. Port B1 is connected to the large chamber of the cylinder, and port A1 is connected to the small chamber of the cylinder. The inlet of the hydraulically controlled directional valve 300 is connected to port A1, and the outlet of the hydraulically controlled directional valve 300 is connected to the first inlet (port 1 in the figure) of the shuttle valve 400. The control port of the hydraulically controlled directional valve 300 is also shown. Connected to port B, when a preset pressure oil flows into the control port, the hydraulic directional valve 300 is displaced and disconnects its inlet and outlet ports; the second inlet port of the shuttle valve 400 (i.e. port 2 in the figure) is connected to the outlet port of the balance valve 100 (i.e. port 2 in the figure), and the outlet port of the shuttle valve 400 (i.e. port 3 in the figure) is connected to the control port of the hydraulic check valve 200 (i.e. port 3 in the figure). When a preset pressure oil flows into the control port, the hydraulic check valve 300 is always in the closed state.

[0036] Further options, such as Figure 2 As shown, the inlet of the hydraulic check valve 200 (port 1 in the figure) is connected to port A1, and the outlet of the hydraulic check valve 200 (port 2 in the figure) is connected to port B1. The inlet of the balance valve 100 (port 1 in the figure) is connected to port A1, the outlet of the balance valve 100 (port 2 in the figure) is connected to port A, and the control port of the balance valve 100 (port 3 in the figure) is connected to port B1. When a preset pressure oil flows into the control port, the balance valve 100 opens to connect the inlet and outlet. The balance valve 100 also has a bypass check valve inside, with its inlet connected to port A and its outlet connected to port A1.

[0037] Further options, such as Figure 2 As shown, a throttling orifice is provided in the oil circuit between the control port and the B oil port of the hydraulic directional valve 300.

[0038] Continue to refer to Figure 2 As shown, the working process of the hydraulic control system is as follows.

[0039] When the jaws close due to external force, the pressure in the small chamber of the hydraulic cylinder increases, while the pressure in the large chamber decreases and tends to suck in air. The hydraulic control directional valve remains in the left position under the action of the spring force. The high-pressure oil in the small chamber of the hydraulic cylinder is introduced into the hydraulic control check valve 3 through the hydraulic control directional valve and shuttle valve port 1, so that the hydraulic control check valve is always in the closed state, thereby realizing the pressure holding function of the small chamber of the hydraulic cylinder and avoiding the jaw closing phenomenon caused by external force in the static state.

[0040] Furthermore, the hydraulic control system does not affect the cylinder speed-up function during the shearing process.

[0041] When the piston extends, oil enters through port B of the speed-increasing valve. The hydraulically controlled directional valve overcomes the spring force and operates in the right-hand position, preventing the pressure oil in the small chamber of the cylinder from acting on port 1 of the shuttle valve. The hydraulically controlled check valve operates unidirectionally from port 1 to port 2, thus ensuring the speed-increasing function of the cylinder during shearing. When the cylinder retracts, the high-pressure oil from port A of the speed-increasing valve acts simultaneously on ports 3 and 1 of the hydraulically controlled check valve through port 2 of the shuttle valve and the bypass check valve inside the balance valve. Therefore, the hydraulically controlled check valve cannot open, ensuring the cylinder retracts normally.

[0042] The working device provided by this utility model is described below. The working device described below can be referred to in correspondence with the hydraulic control system described above.

[0043] The present invention provides a working device comprising a boom, a stick, and a shearing tool connected together, wherein the hydraulic cylinder of the shearing tool is equipped with the aforementioned hydraulic control system.

[0044] The beneficial effects achieved by the working device provided by this utility model are consistent with the beneficial effects achieved by the hydraulic control system provided by this utility model, so they will not be repeated here.

[0045] It should be noted that the aforementioned shearing tools can be scissors.

[0046] The engineering machinery provided by this utility model is described below. The engineering machinery described below can be referred to in correspondence with the working device described above.

[0047] The engineering machinery provided by this utility model may include the working device as described in any of the above embodiments.

[0048] The beneficial effects achieved by the engineering machinery provided by this utility model are consistent with the beneficial effects achieved by the working device provided by this utility model, so they will not be repeated here.

[0049] It should be noted that the aforementioned construction machinery can be excavators.

[0050] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0051] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features found in other embodiments but not others, combinations of features from different embodiments are also within the scope of protection of this invention and form different embodiments. For example, in the embodiments described above, those skilled in the art can use them in combination based on known technical solutions and the technical problems to be solved by this application.

[0052] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A hydraulic control system, mainly used in shearing tools, comprising a speed-increasing valve composed of a balance valve and a hydraulically controlled check valve, wherein the speed-increasing valve includes an A1 port, a B1 port, an A port, and a B port, the B1 port being connected to the large chamber of the hydraulic cylinder, and the A1 port being connected to the small chamber of the hydraulic cylinder; characterized in that: It also includes shuttle valves and hydraulically controlled directional valves; The inlet of the hydraulic directional valve is connected to port A1, the outlet of the hydraulic directional valve is connected to the first inlet of the shuttle valve, and the control port of the hydraulic directional valve is connected to port B. When a preset pressure oil flows into the control port, the hydraulic directional valve is displaced and disconnects its inlet and outlet. The second oil inlet of the shuttle valve is connected to the oil outlet of the balance valve, and the oil outlet of the shuttle valve is connected to the control port of the hydraulic check valve. When a preset pressure oil flows into the control port, the hydraulic check valve is always in the closed state.

2. A hydraulic control system according to claim 1, characterized in that: The inlet of the hydraulic check valve is connected to port A1, and the outlet of the hydraulic check valve is connected to port B1.

3. A hydraulic control system according to claim 1, characterized in that: The inlet of the balance valve is connected to port A1, the outlet of the balance valve is connected to port A, and the control port of the balance valve is connected to port B1. When a preset pressure oil flows into the control port, the balance valve opens to connect the inlet and outlet.

4. A hydraulic control system according to claim 3, characterized in that: The balance valve is also equipped with a bypass check valve. The oil inlet of the bypass check valve is connected to the A oil port, and the oil outlet of the bypass check valve is connected to the A1 oil port.

5. A hydraulic control system according to claim 1, characterized in that: A throttling orifice is provided in the oil passage between the control port and the B port of the hydraulic directional valve.

6. A working device comprising a boom, a stick, and a shear-like implement connected together, characterized in that: The hydraulic cylinders in the shearing pliers are equipped with a hydraulic control system as described in any one of claims 1 to 5.

7. A working device according to claim 6, characterized in that: The cutting tools mentioned include scissor shears.

8. An engineering machinery, characterized in that: It includes the hydraulic control system according to any one of claims 1 to 5; or, it includes the working device according to claim 6 or 7.

9. The engineering machinery according to claim 8, characterized in that: The construction machinery includes excavators.

Images