Electric rotation control system and method and excavator

Abstract

The invention discloses an electric rotation control system and method and an excavator in the technical field of engineering machinery, and aims to solve the problem that in the prior art, due to fluctuation of a pressure source of a pilot pressure reducing valve group, the rotation speed is slowed down or even stopped. The system comprises a load-sensitive pump, a main valve, a handle mechanism and an oil tank, load-sensitive pump return oil, main valve return oil and handle mechanism return oil are all connected with the oil tank, an oil outlet of the load-sensitive pump is connected with the handle mechanism and the main valve at the same time, and the main valve comprises a first link and a plurality of working links; the pressure of the main overflow valve is changed, the LS pressure of the main valve is fed back to the adjusting characteristic of the load-sensitive pump, the pressure of an outlet of the load-sensitive pump is larger than the set pressure of a pilot pressure reducing valve set in a handle mechanism under the single rotation action and other actions, and it is guaranteed that the electric rotation action is normal under the condition that idle speed energy consumption is not increased.

Description

Technical Field

[0001] The present invention relates to an electric rotation control system, method and excavator, and belongs to the technical field of engineering machinery. Background Art

[0002] With the country's requirements for low and zero emissions in construction machinery, the use of electric drives in construction machinery has become increasingly common. Currently, most have entered the stage where pump motors have replaced diesel engines, and swing motors have replaced rotary motors. Micro excavators often use a load-sensing hydraulic system, equipped with a main pump. Its pilot oil circuit is drawn from the main pump outlet, reduced by a pressure reducing valve, and then supplied to the various pilot control oil circuits. The idle relief pressure of the main valve is generally lower than the set pressure of the pilot pressure reducing valve (reducing idle energy consumption). The motor drive mode is used for swing operation. The remaining hydraulic control methods only add a pressure sensor at the pilot handle port. When performing a single swing action, the maximum pilot pressure detected is the main valve idle relief pressure (i.e., the main relief valve spring set pressure). When performing a compound action, the maximum pilot pressure detected is the pressure of the pressure reducing valve outlet. Due to the difference in pressure between the two, the speed of the compound action switching to the single swing action will slow down, jitter, or even stop, affecting the working performance of the excavator. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide an electric swing control system, method and excavator to solve the abnormal problem of slowing down or even stopping the swing speed due to fluctuations in the pressure source of the pilot pressure reducing valve group.

[0004] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions: In a first aspect, the present invention provides an electric swing control system, comprising a load-sensing pump, a main valve, a handle mechanism and an oil tank, wherein the return oil of the load-sensing pump, the return oil of the main valve and the return oil of the handle mechanism are all connected to the oil tank, and the oil outlet of the load-sensing pump is simultaneously connected to the handle mechanism and the main valve, the main valve comprises a first joint and a plurality of working joints, the handle mechanism comprises a plurality of pilot output pressure oil ports, wherein two of the pilot output pressure oil ports are respectively provided with a first pressure sensor and a second pressure sensor, the first pressure sensor and the second pressure sensor are both electrically connected to a first controller, the remaining pilot output pressure oil ports are connected to the control pilot side of each of the working joints and are used to control the reversing of the working joints, and the first controller is connected to a swing motor; The first link includes a main overflow valve, the oil inlet end of the main overflow valve is connected to the load-sensing pump, the oil outlet end of the main overflow valve is connected to the oil tank, the hydraulic control end of the main overflow valve is connected to the main valve LS feedback oil circuit, and the main valve LS feedback oil circuit is connected to the feedback control port of the load-sensing pump and the input end of the third pressure sensor. The third pressure sensor and the electrical control end of the main overflow valve are both electrically connected to the second controller.

[0005] Furthermore, the handle mechanism includes a pilot pressure reducing valve group and a manipulation handle, the pilot pressure reducing valve group is connected to the load sensing pump, and the manipulation handle is connected to the pilot pressure reducing valve group.

[0006] Furthermore, the main overflow valve is an electro-hydraulic controlled overflow valve, the input end of the main overflow valve is connected to the oil outlet of the load-sensing pump, the output end of the main overflow valve is connected to the oil tank, its hydraulic control end is controlled by the main valve LS feedback oil circuit, and its electrical control end is controlled by the second controller.

[0007] Furthermore, the main valve LS feedback oil circuit is connected to the load sensing pump feedback control port and the input end of the third pressure sensor at the same time, and the output end of the third pressure sensor is connected to the electric control end of the main relief valve through the second controller.

[0008] Furthermore, the pilot pressure reducing valve group includes a fixed value pressure reducing valve.

[0009] Furthermore, each of the working links is connected to an actuator.

[0010] Furthermore, the actuator includes a hydraulic cylinder and a hydraulic motor.

[0011] In a second aspect, the present invention provides a slewing control method, based on the electric slewing control system described in the first aspect, comprising the following steps: Acquire pressure signals detected by the first pressure sensor, the second pressure sensor, and the third pressure sensor; The main relief valve is controlled according to the pressure signals detected by the first pressure sensor, the second pressure sensor, and the third pressure sensor.

[0012] Furthermore, controlling the main relief valve according to the pressure signals detected by the first pressure sensor, the second pressure sensor, and the third pressure sensor specifically includes: If the third pressure sensor detects a pressure signal, no electrical signal is output to the main relief valve, so that the electrical control terminal of the main relief valve is in a power-off state; If the first pressure sensor or the second pressure sensor detects a pressure signal and the third pressure sensor does not detect a pressure signal, an electrical signal is output to the main relief valve, so that the electrical control end of the main relief valve is in an energized state; If the first pressure sensor, the second pressure sensor and the third pressure sensor detect no pressure signal, no electrical signal is output to the main relief valve.

[0013] In a third aspect, the present invention provides an excavator comprising the electric swing control system described in the first aspect.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The electric swing control system detects the signals of the first, second and third pressure sensors, changes the pressure of the main relief valve, and feeds back the main valve LS pressure to the load-sensing pump adjustment characteristics. In this way, the load-sensing pump outlet pressure is made greater than the set pressure of the pilot pressure-reducing valve group in the handle mechanism under single swing action and other actions. In addition, the electric swing action is ensured to be normal without increasing the idle energy consumption, and the situation in which the speed of the composite action switches to the single swing action and slows down, shakes or even stops is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 1 is a schematic diagram of the system structure of an electric swing control system provided according to an embodiment of the present invention.

[0016] In the figure: 1. Oil tank; 2. Load-sensing pump; 3. Main valve; 4. First pressure sensor; 5. Handle mechanism; 6. First controller; 7. Arm cylinder; 8. Boom cylinder; 9. Second pressure sensor; 10. Third pressure sensor; 11. Main overflow valve; 12. Second controller; 13. Rotary motor. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0018] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0019] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances. Example 1:

[0020] like Figure 1As shown, the present invention provides an electric rotary control system, including a load-sensitive pump 2, a main valve 3, a handle mechanism 5 and an oil tank 1, wherein the return oil of the load-sensitive pump 2, the return oil of the main valve 3 and the return oil of the handle mechanism 5 are all connected to the oil tank 1, and the oil outlet of the load-sensitive pump 2 is simultaneously connected to the handle mechanism 5 and the main valve 3, the main valve 3 includes a first joint and a plurality of working joints, the handle mechanism 5 includes a plurality of pilot output pressure oil ports, wherein two of the pilot output pressure oil ports are respectively provided with a first pressure sensor 4 and a second pressure sensor 9, the first pressure sensor 4 and the second pressure sensor 9 are both electrically connected to a first controller 6, and the remaining pilot output pressure oil ports are connected to the control pilot side of each of the working joints and are used to control the reversing of the working joints, the first controller 6 is connected to a rotary motor 13; the first joint The connection includes a main overflow valve 11, the oil inlet end of the main overflow valve 11 is connected to the load-sensitive pump 2, the oil outlet end of the main overflow valve 11 is connected to the oil tank 1, and the hydraulic control end of the main overflow valve 11 is connected to the main valve LS feedback oil circuit. In addition to being connected to the feedback control port of the load-sensitive pump 2, the main valve LS feedback oil circuit is also connected to the input end of the third pressure sensor 10. The third pressure sensor 10 and the electrical control end of the main overflow valve 11 are both electrically connected to the second controller 12; optionally, the first controller 6 is a rotary motor controller, and the oil tank 1 is a hydraulic oil tank; the main valve LS feedback oil circuit is simultaneously connected to the feedback control port of the load-sensitive pump 2 and the input end of the third pressure sensor 10, and the output end of the third pressure sensor 10 is connected to the electrical control end of the main overflow valve 11 through the second controller 12.

[0021] like Figure 1 As shown, the pilot pressure reducing handle operating part in the figure is the handle mechanism 5, and the positions of pa1, pb1, pa2, and pb2 in the main valve 3 in the figure are the working links.

[0022] The handle mechanism 5 includes a pilot pressure reducing valve group and a joystick, the pilot pressure reducing valve group is connected to the load sensing pump 2, and the joystick is connected to the pilot pressure reducing valve group; the pilot pressure reducing valve group includes a fixed value pressure reducing valve (fixed value pressure reducing valve: a hydraulic valve that reduces the input pressure P to a set value P0 output, requiring P≥P0, when P<P0, then P=P); in this patent, the pilot output pressure oil port includes pa0 and pb0 ports, pa0 and pb0 are respectively connected to the first controller 6 through the first pressure sensor 4 and the second pressure sensor 9, the first controller 6 is connected to the rotary motor 13, and the remaining pilot output pressure oil ports (i.e. pa1, pb1, pa2, pb2) are connected to the control pilot side of each working control link of the main valve 3 and control the reversing of the working link; each of the working links is connected to an actuator; the actuator includes a hydraulic cylinder and a hydraulic motor, and the hydraulic cylinder includes a boom cylinder 7 and a boom cylinder 8.

[0023] Specifically, when working, the load-sensing pump 2 draws oil from the oil tank 1, and its outlet oil circuit enters the handle mechanism 5 one way to provide an oil source to the handle mechanism 5, and the main valve 3 one way to supply oil to the main oil circuit; in this patent, the boom cylinder 7 is set as the first working link, and the boom cylinder 8 is set as the second working link, and other working links should also be included; for the hydraulic control part, when the operating handle is actuated, the handle mechanism 5 outputs pressure through the pilot output pressure oil port (such as pa1, pb1, pa2, pb2), which is connected to the pilot port corresponding to the main valve 3, pushing the main valve core to move, thereby realizing the extension and retraction of the boom cylinder 7 and the boom The oil cylinder 8 rotates forward and backward; the first pressure sensor 4 and the second pressure sensor 9 are connected to the pilot output pressure oil port pa0 / pb0 that controls the rotary action, and pa0 / pb0 serves as the input end. When the first pressure sensor 4 and the second pressure sensor 9 detect their pressure signals, they are converted into corresponding electrical signals and output to the rotary motor 13 to control its left and right rotation; the input end of the third pressure sensor 10 is connected to the LS hydraulic control signal fed back by the main valve 3 (i.e., the main valve LS feedback oil circuit), which is used to detect the maximum pressure between multiple working links, and the output end is connected to the second controller 12. The electrical control part of the main relief valve 11 is also connected to the second controller 12. When performing a compound action, the third pressure sensor 10 detects the LS hydraulic control signal, which is identified and judged by the second controller 12, and no electrical signal is output to the main relief valve 11. At this time, the electrical control part of the main relief valve 11 is in a power-off state, thereby ensuring that the maximum pressure of the main relief valve 11 does not exceed the set pressure, thereby ensuring the safety of the system. At this time, the outlet pressure of the load-sensing pump 2 is greater than the set pressure of the fixed-value pressure reducing valve in the handle mechanism 5, that is, it can ensure that the output pressure of the pilot oil source is stable; when performing a single rotary action, this At this time, the outlet pressure of the load-sensitive pump 2 is the overflow pressure of the main overflow valve 11. Since the third pressure sensor 10 has no input pressure signal, the second controller 12 identifies and judges and outputs an electrical signal to the main overflow valve 11. At this time, the electronic control part of the main overflow valve 11 compresses the spring, so that its overflow pressure, that is, the outlet pressure of the load-sensitive pump 2, is slightly greater than the set pressure of the fixed-value pressure reducing valve in the handle mechanism 5, ensuring the stability of the output pressure of the pilot oil source; when the first pressure sensor 4, the second pressure sensor 9 and the third pressure sensor 10 have no pressure signal output, it is in the shutdown state and no relevant signal is issued by each control.

[0024] This patent cooperates with the first pressure sensor 4, the second pressure sensor 9 and the third pressure sensor 10 to detect the LS feedback control oil signal of the main valve 3 and the pressure signal of the handle mechanism 5, identify and distinguish the action of the rotary motor 13 from other hydraulic control actions, and change the pressure of the main relief valve 11. According to the LS pressure feedback of the main valve, the load-sensitive pump 2 adjustment characteristics are adjusted to achieve the following: in the case of single rotary action and other actions, the outlet pressure of the load-sensitive pump 2 is greater than the set pressure of the pilot pressure reducing valve group in the handle mechanism 5, and the normal electric rotary action is guaranteed without increasing the idle energy consumption, avoiding the situation where the speed of the composite action switches to the single rotary action and slows down, shakes or even stops. Example 2:

[0025] The present invention provides a rotation control method, based on the electric rotation control system described in embodiment 1, comprising the following steps: Obtain the pressure signals detected by the first pressure sensor 4, the second pressure sensor 9 and the third pressure sensor 10; the pressure signals can be used to determine the rotary single action and other related actions, and control the electronic control end of the main relief valve 11; The main relief valve 11 is controlled according to the pressure signals detected by the first pressure sensor 4 , the second pressure sensor 9 , and the third pressure sensor 10 .

[0026] The control of the main relief valve 11 according to the pressure signals detected by the first pressure sensor 4, the second pressure sensor 9 and the third pressure sensor 10 specifically includes: If the third pressure sensor 10 detects a pressure signal, it does not output an electrical signal to the main relief valve 11, so that the electrical control terminal of the main relief valve 11 is in a power-off state; If the first pressure sensor 4 or the second pressure sensor 9 detects a pressure signal, and the third pressure sensor 10 does not detect a pressure signal, an electrical signal is output to the main relief valve 11, so that the electrical control end of the main relief valve 11 is in an energized state; If the first pressure sensor 4 , the second pressure sensor 9 and the third pressure sensor 10 detect no pressure signal, no electrical signal is output to the main relief valve 11 , and the excavator is in an idling state. Example 3:

[0027] The present invention provides an excavator, comprising the electric swing control system described in the first embodiment.

[0028] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An electric swing control system, characterized in that: It includes a load-sensitive pump, a main valve, a handle mechanism and an oil tank, wherein the return oil of the load-sensitive pump, the return oil of the main valve and the return oil of the handle mechanism are all connected to the oil tank, and the oil outlet of the load-sensitive pump is simultaneously connected to the handle mechanism and the main valve, the main valve includes a first joint and a plurality of working joints, the handle mechanism includes a plurality of pilot output pressure oil ports, wherein two of the pilot output pressure oil ports are respectively provided with a first pressure sensor and a second pressure sensor, the first pressure sensor and the second pressure sensor are both electrically connected to a first controller, and the remaining pilot output pressure oil ports are connected to the control pilot side of each of the working joints and are used to control the reversing of the working joints, and the first controller is connected to a rotary motor; The first link includes a main overflow valve, the oil inlet end of the main overflow valve is connected to the load-sensitive pump, the oil outlet end of the main overflow valve is connected to the oil tank, the hydraulic control end of the main overflow valve is connected to the main valve LS feedback oil circuit, and the main valve LS feedback oil circuit is connected to the feedback control port of the load-sensitive pump and is also connected to the input end of the third pressure sensor. The third pressure sensor and the electrical control end of the main overflow valve are both electrically connected to the second controller.

2. The electric swing control system according to claim 1, characterized in that: The handle mechanism comprises a pilot pressure reducing valve group and a manipulation handle, wherein the pilot pressure reducing valve group is connected to the load sensing pump, and the manipulation handle is connected to the pilot pressure reducing valve group.

3. The electric swing control system according to claim 1, characterized in that: The main relief valve is an electro-hydraulic controlled relief valve, the input end of the main relief valve is connected to the oil outlet of the load sensing pump, the output end of the main relief valve is connected to the oil tank, its hydraulic control end is controlled by the main valve LS feedback oil circuit, and its electrical control end is controlled by the second controller.

4. The electric swing control system according to claim 1, characterized in that: The main valve LS feedback oil circuit is connected to the load sensing pump feedback control port and the input end of the third pressure sensor at the same time, and the output end of the third pressure sensor is connected to the electrical control end of the main overflow valve through the second controller.

5. The electric swing control system according to claim 2, characterized in that: The pilot pressure reducing valve group includes a fixed value pressure reducing valve.

6. The electric swing control system according to claim 2, characterized in that: Each of the working links is connected with an actuator.

7. The electric swing control system according to claim 6, characterized in that: The actuator comprises a hydraulic cylinder and a hydraulic motor.

8. An electric swing control method, based on the electric swing control system according to any one of claims 1 to 7, characterized in that: The following steps are involved: Acquire pressure signals detected by the first pressure sensor, the second pressure sensor, and the third pressure sensor; The main relief valve is controlled according to the pressure signals detected by the first pressure sensor, the second pressure sensor and the third pressure sensor.

9. The electric rotation control method according to claim 1, characterized in that: The controlling of the main relief valve according to the pressure signals detected by the first pressure sensor, the second pressure sensor and the third pressure sensor specifically includes: If the third pressure sensor detects a pressure signal, no electrical signal is output to the main relief valve, so that the electrical control end of the main relief valve is in a power-off state; If the first pressure sensor or the second pressure sensor detects a pressure signal, and the third pressure sensor does not detect a pressure signal, an electrical signal is output to the main relief valve, so that the electrical control end of the main relief valve is in an energized state; If the first pressure sensor, the second pressure sensor and the third pressure sensor detect no pressure signal, no electrical signal is output to the main relief valve.

10. An excavator, characterized in that: The electric swing control system comprises the electric swing control system as claimed in any one of claims 1 to 7.

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