Machine tool hydraulic system and excavator

Abstract

The utility model discloses a machine tool hydraulic system which comprises a pump, an oil tank, a first reversing valve, a machine tool reversing valve, a first one-way valve, a second one-way valve, a second reversing valve and a control oil cylinder. One pipeline of the control oil cylinder is connected with the oil tank through the first reversing valve, and the other pipeline is connected with the pump through the first reversing valve; one pipeline of the operation machine is connected with the oil tank through the machine reversing valve, and the other pipeline is connected with the pump through the machine reversing valve; two pipelines of the operation machine are respectively connected with the oil tank through a first one-way valve and a second one-way valve; the machine tool hydraulic system can be controlled by means of the controller, automatic pressure relief of a machine tool pipeline is achieved, the hydraulic system is protected, and the workload of machine tool replacement is reduced; the electromagnetic valves are adopted to control the hydraulic control one-way valves to drain oil in the machine tool pipeline, the number of the electromagnetic valves is reduced, and cost is reduced; the pressure sensor monitors the pressure of the machine tool in real time to provide basis for working condition analysis.

Description

Technical Field

[0001] The utility model patent relates to the field of hydraulic systems for engineering machinery, and in particular to a hydraulic system for machinery and an excavator. Background Art

[0002] Hydraulic excavator tools are increasingly used, and different operations can be achieved by replacing different tools. Quick-change connectors are widely used. For fully automatic quick-change connectors, since it involves the plugging and unplugging of hydraulic quick-connect connectors, especially when the tool pipeline is pressurized, it is necessary to plug and unplug under pressure. At this time, a large force is required, which has a certain impact on the life of the connector.

[0003] Generally, the pipelines of excavator tools do not have a pressure relief function; some manufacturers install electromagnetic unloading valves on all tool circuits to relieve pressure through manual operation.

[0004] For excavators without a pressure relief function in the pipeline, when using a fully automatic quick-change connector, it is difficult to plug and unplug the quick-connect connector, and the service life of the connector is affected; the system that uses manual pressure relief with an electromagnetic unloading valve has a large number of solenoid valves, high costs, and the driver is prone to forget to perform the oil unloading operation. Utility Model Content

[0005] The utility model aims to overcome the deficiencies in the prior art and provide a machine hydraulic system and an excavator.

[0006] To solve the problems of the prior art, the utility model discloses a hydraulic system for a machine tool, comprising: a pump, a fuel tank, a first reversing valve, a machine tool reversing valve, a first non-return valve, a second non-return valve, a second reversing valve and a control cylinder; one pipeline of the control cylinder is connected to the fuel tank through the first reversing valve, and the other pipeline is connected to the pump through the first reversing valve, and the pump is connected to the fuel tank; one pipeline of the working machine is connected to the fuel tank through the machine tool reversing valve, and the other pipeline is connected to the pump through the machine tool reversing valve; the two pipelines of the working machine are connected to the fuel tank through the first non-return valve and the second non-return valve respectively; one end of the second reversing valve is connected to the first non-return valve and the second non-return valve, and the other end is divided into two pipelines, one pipeline is connected to the fuel tank, and the other pipeline is connected to the pump.

[0007] Furthermore, it also includes a shuttle valve, which connects two pipelines of the working tool.

[0008] Furthermore, the first reversing valve and the second reversing valve are both electromagnetic reversing valves.

[0009] Furthermore, it also includes a controller, which is connected to the first reversing valve and the second reversing valve respectively.

[0010] Furthermore, it also includes a pressure sensor, one end of which is connected to the shuttle valve, and the other end of which is connected to the controller.

[0011] Furthermore, it also includes a first overflow valve, one end of which is connected to the pipeline between the second reversing valve and the pump, and the other end of which is connected to the oil tank.

[0012] Furthermore, it also includes a second overflow valve, one end of which is connected to the pipeline between the first reversing valve and the oil tank, and the other end of which is connected to the oil tank.

[0013] Furthermore, the first one-way valve and the second one-way valve are both hydraulically controlled one-way valves.

[0014] Correspondingly, the utility model also provides an excavator, wherein the excavator is provided with the above-mentioned machine hydraulic system.

[0015] The utility model has the beneficial effects:

[0016] The hydraulic system of the machine tool of the utility model can be controlled by means of a controller to realize automatic pressure relief of the machine tool pipeline, thereby protecting the hydraulic system and reducing the workload of machine tool replacement;

[0017] The solenoid valve is used to control the hydraulic one-way valve to drain the oil from the machine pipeline, which reduces the number of solenoid valves and reduces costs;

[0018] The pressure sensor monitors the tool pressure in real time, providing a basis for working condition analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the utility model.

[0020] Reference numerals:

[0021] 1- pump; 2- oil tank; 3- first reversing valve; 4- tool reversing valve; 5- shuttle valve; 6- pressure sensor; 7- first one-way valve; 8- first reversing valve; 9- second reversing valve; 10- controller; 11- first overflow valve; 12- second overflow valve; 13- control cylinder. DETAILED DESCRIPTION

[0022] The utility model is further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the utility model, and cannot be used to limit the protection scope of the utility model. Example

[0023] like Figure 1As shown, the hydraulic system of the machine tool of this embodiment is characterized by a pump 1, a fuel tank 2, a first reversing valve 3, a machine tool reversing valve 4, a first non-return valve 7, a second non-return valve 8, a second reversing valve 9 and a control cylinder 13; one pipeline of the control cylinder 13 is connected to the fuel tank 2 through the first reversing valve 3, and the other pipeline is connected to the pump 1 through the first reversing valve 3, and the pump 1 is connected to the fuel tank 2; one pipeline of the working machine tool is connected to the fuel tank 2 through the machine tool reversing valve 4, and the other pipeline is connected to the pump 1 through the machine tool reversing valve 4; the two pipelines of the working machine tool are connected to the fuel tank 2 through the first non-return valve 7 and the second non-return valve 8 respectively; one end of the second reversing valve 9 is connected to the first non-return valve 7 and the second non-return valve 8, and the other end is divided into two pipelines, one pipeline is connected to the fuel tank 2, and the other pipeline is connected to the pump 1. It also includes a shuttle valve 5, and the shuttle valve 5 connects the two pipelines of the working machine tool. The first reversing valve 3 and the second reversing valve 9 are both electromagnetic reversing valves. It also includes a controller 10, which is connected to the first reversing valve 3 and the second reversing valve 9 respectively. It also includes a pressure sensor 6, one end of which is connected to the shuttle valve 5, and the other end is connected to the controller 10. It also includes a first overflow valve 11, one end of which is connected to the pipeline between the second reversing valve 9 and the pump 1, and the other end is connected to the oil tank 2. It also includes a second overflow valve 12, one end of which is connected to the pipeline between the first reversing valve 3 and the oil tank 2, and the other end is connected to the oil tank 2. The first check valve 7 and the second check valve 8 are both hydraulically controlled check valves. Example

[0024] like Figure 1 As shown, based on Example 1, this embodiment provides a specific oil port connection method of the hydraulic system of the machine tool; the first reversing valve 3 is provided with an A oil port, a B oil port, a C oil port and a D oil port; the control oil cylinder 13 is provided with an A oil port and a B1 oil port; the A1 oil port is connected to the C oil port through a pipeline, the B1 oil port is connected to the D oil port through a pipeline, the A oil port is connected to the pump 1 through a pipeline, and the B oil port is connected to the oil tank 2 through a pipeline;

[0025] The working tool is provided with an A2 oil port and a B2 oil port, and the tool reversing valve 4 is provided with an A3 oil port and a B3 oil port; the A2 oil port is connected to the A3 oil port through a pipeline to form a pipeline A2A3; the B2 oil port is connected to the B3 oil port through a pipeline to form a pipeline B2B3; the tool reversing valve 4 is provided with 1 oil port, 2 oil port, 3 oil port and 4 oil port inside, wherein the 1 oil port is connected to the pump 1 through a pipeline, and the 2 oil port is connected to the oil tank 2 through a pipeline; the 3 oil port is connected to the A3 oil port; the 4 oil port is connected to the B3 oil port; when the reversing valve core of the tool reversing valve 4 is in the middle position, the 1 oil port, the 2 oil port, the 3 oil port and the 4 oil port are not connected to each other;

[0026] The first check valve 7 is provided with oil ports 10, 20 and 30; the second check valve 8 is provided with oil ports 11, 21 and 31; the second reversing valve 9 is provided with oil ports 14, 24 and 34; the oil port 20 is connected to the pipeline B2B3, the oil port 21 is connected to the pipeline A2A3, the oil ports 10 and 11 are connected to the oil tank 2 through a pipeline, the oil ports 30 and 31 are connected to the oil port 34, the oil port 14 is connected to the pump 1 through a pipeline, and the oil port 24 is connected to the oil tank 2 through a pipeline;

[0027] The shuttle valve 5 is provided with oil ports 13, 23 and 33; the oil port 13 is connected to the pipeline A2A3, the oil port 23 is connected to the pipeline B2B3, and the oil port 33 is connected to the pressure sensor 6. Example

[0028] This embodiment provides the working principle of the hydraulic system of the implement of embodiment 1 and embodiment 2;

[0029] When using a fully automatic quick-change connector to replace tools, the power for the quick-connect connector connected to the A2 oil port and the B2 oil port of the working tool to be disconnected or connected comes from the control cylinder 13; and whether the tool is connected or disconnected, the quick-change cylinder needs to be retracted, that is, the quick-change control first reversing valve 3 is energized and the valve core is reversed.

[0030] When the fully automatic quick-change connector is connected or disconnected, the tool reversing valve 4 must be in the middle position, that is, the valve core of the tool reversing valve 4 is in the middle position, and oil ports 1, 2, 3, and 4 are not connected to each other.

[0031] When the full-automatic quick-change connector is disengaged from the quick-plug connector, the driver operates the handle button, and at this time, the controller 10 receives the operation signal.

[0032] At this time, the controller 10 receives the pressure value of the tool pipeline A2A3 and the pipeline B2B3 tested by the pressure sensor 6 through the shuttle valve 5; if there is pressure in the hydraulic oil in the pipeline A2A3 and the pipeline B2B3 between the working tool and the tool reversing valve 4, the pressure value is transmitted to the pressure sensor 6 through the 33 port of the shuttle valve 5. If the pressure measured by the sensor 6 is P>P 设定 , the controller 10 sends a signal to the second reversing valve 9; P 设定 The maximum pressure allowed for pressurized operation of the quick-connect fittings used in fully automatic quick-change applications is generally 3-5 MPa.

[0033] The controller 10 sends a signal to the second reversing valve 9, the second reversing valve 9 is electrically reversed, ports 14 and 33 are connected, and the pressure oil enters ports 30 of the first check valve 7 and port 31 of the second check valve 8 respectively, opening the two hydraulically controlled check valves in reverse; at this time, ports 10 and 20 of the first check valve 7 and ports 11 and 22 of the second check valve 8 are respectively connected, and the hydraulic oil in the tool pipeline A2A3 and pipeline B2B3 returns to the oil tank, completing the pressure relief operation.

[0034] After the controller 10 receives the first reversing valve 3 being operated by electricity, i.e., the driver's handle operation signal, the controller 10 compares the sensor pressure real-time pressure P every △t. 实时 and system set pressure P 设定， △t is generally required to be less than 0.05S until the sensor pressure P 实时 <P 设定 .

[0035] When P 实时 <P 设定 , the controller 10 sends an electrical signal to the first reversing valve 3, the first reversing valve 3 is energized, the valve core moves, and is in the right working position. At this time, the A port and the D port of the first reversing valve 3 are connected, and the B port and the C port are connected; the pressure oil flows from the A port and the D port to the B1 port of the small chamber of the control cylinder 13, and the cylinder retracts; at the same time, the pressure oil in the large chamber of the cylinder returns to the oil tank through the A1 port of the cylinder, the C port and the B port of the first reversing valve 3, and the oil return is completed. At this time, driven by the control cylinder 13, the quick-connect connector completes the disengagement operation. Example

[0036] This embodiment provides an excavator, which is provided with the machine hydraulic system described in any one of Embodiments 1-3.

[0037] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. At the same time, in the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the equipment or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present utility model. In the drawings of the present invention, the filling patterns are only used to distinguish the layers and no other limitations are given.

[0038] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A hydraulic system for a machine tool, characterized in that: include: A pump (1), a fuel tank (2), a first reversing valve (3), a tool reversing valve (4), a first non-return valve (7), a second non-return valve (8), a second reversing valve (9) and a control cylinder (13); one pipeline of the control cylinder (13) is connected to the fuel tank (2) via the first reversing valve (3), and the other pipeline is connected to the pump (1) via the first reversing valve (3); the pump (1) is connected to the fuel tank (2); one pipeline of the working tool is connected to the fuel tank (2) via the tool reversing valve (4), and the other pipeline is connected to the pump (1) via the tool reversing valve (4); the two pipelines of the working tool are connected to the fuel tank (2) via the first non-return valve (7) and the second non-return valve (8) respectively; one end of the second reversing valve (9) is connected to the first non-return valve (7) and the second non-return valve (8), and the other end is divided into two pipelines, one pipeline is connected to the fuel tank (2), and the other pipeline is connected to the pump (1).

2. The implement hydraulic system according to claim 1, characterized in that: It also comprises a shuttle valve (5), wherein the shuttle valve (5) connects two pipelines of the working tool.

3. The implement hydraulic system according to claim 2, characterized in that: The first reversing valve (3) and the second reversing valve (9) are both electromagnetic reversing valves.

4. The implement hydraulic system according to claim 3, characterized in that: It also includes a controller (10), wherein the controller (10) is connected to the first reversing valve (3) and the second reversing valve (9) respectively.

5. The implement hydraulic system according to claim 4, characterized in that: It also includes a pressure sensor (6), one end of the pressure sensor (6) being connected to the shuttle valve (5) and the other end of the pressure sensor (6) being connected to the controller (10).

6. The implement hydraulic system according to claim 1, characterized in that: It also comprises a first overflow valve (11), one end of the first overflow valve (11) being connected to the pipeline between the second reversing valve (9) and the pump (1), and the other end of the first overflow valve (11) being connected to the oil tank (2).

7. The implement hydraulic system according to claim 1, characterized in that: It also comprises a second overflow valve (12), one end of the second overflow valve (12) being connected to the pipeline between the first reversing valve (3) and the oil tank (2), and the other end of the second overflow valve (12) being connected to the oil tank (2).

8. The implement hydraulic system according to claim 1, characterized in that: The first one-way valve (7) and the second one-way valve (8) are both hydraulically controlled one-way valves.

9. An excavator, characterized in that: The excavator is provided with a tool hydraulic system as described in any one of claims 1 to 8.

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