An electric rotary control system, method and excavator

Abstract

This invention discloses an electric swing control system, method, and excavator in the field of engineering machinery technology, aiming to solve the problem of abnormal situations in the prior art where the swing speed slows down or even stops due to pressure source fluctuations in the pilot pressure reducing valve group. It includes a load-sensitive pump, a main valve, a handle mechanism, and an oil tank. The return oil from the load-sensitive pump, the main valve, and the handle mechanism is all connected to the oil tank. The outlet of the load-sensitive pump is simultaneously connected to the handle mechanism and the main valve. The main valve includes a primary connection and multiple working connections. This invention, by changing the pressure of the main relief valve and feeding back the main valve LS pressure to the load-sensitive pump's adjustment characteristics, ensures that the outlet pressure of the load-sensitive pump is greater than the set pressure of the pilot pressure reducing valve group in the handle mechanism during single swing operation and other operations, while guaranteeing normal electric swing operation without increasing idle energy consumption.

Description

Technical Field

[0001] This invention relates to an electric rotary control system, method, and excavator, belonging to the field of engineering machinery technology. Background Technology

[0002] With national requirements for low-emission and zero-emission construction machinery, the use of electric drive devices in construction machinery is becoming increasingly common. Currently, most have moved to the stage where pump motors are replacing diesel engines, and swing motors are replacing swing motors. Mini excavators often employ load-sensitive hydraulic systems, equipped with a main pump. The pilot oil route is led from the main pump outlet, pressure-reducing valve, and then supplied to each pilot control circuit. The main valve's idle overflow pressure is generally lower than the pilot pressure-reducing valve's set pressure (to reduce idle energy consumption). Swing is driven by an electric motor, while the rest is hydraulically controlled. Because it only adds a pilot handle pressure sensor, when swinging is a single action, the maximum detected pilot pressure is the main valve's idle overflow pressure (i.e., the main overflow valve spring set pressure). However, when performing compound actions, the maximum detected pilot pressure is the pressure-reducing valve outlet pressure. Due to this pressure difference, when switching between compound actions and single swing actions, the speed may slow down, vibrate, or even stop, affecting the excavator's working efficiency. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide an electric slewing control system, method and excavator to solve the problem of abnormal situations where the slewing speed slows down or even stops due to pressure source fluctuations in the pilot pressure reducing valve group.

[0004] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution:

[0005] In a first aspect, the present invention provides an electric rotary control system, comprising a load-sensitive pump, a main valve, a handle mechanism, and an oil tank. The return oil from the load-sensitive pump, the main valve, and the handle mechanism is all connected to the oil tank. The outlet of the load-sensitive pump is simultaneously connected to the handle mechanism and the main valve. The main valve includes a primary coupling and multiple working couplings. The handle mechanism includes multiple pilot output pressure ports, wherein two of the pilot output pressure 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 ports are connected to the control pilot side of each working coupling and are used to control the reversing of the working coupling. The first controller is connected to a rotary motor.

[0006] The first connection includes a main relief valve, the oil inlet of which is connected to the load-sensitive pump, the oil outlet of which is connected to the oil tank, the hydraulic control end of which is connected to the main valve LS feedback oil circuit, the main valve LS feedback oil circuit being connected to the feedback control port of the load-sensitive pump and also to the input end of the third pressure sensor, and both the third pressure sensor and the electrical control end of the main relief valve are electrically connected to the second controller.

[0007] Furthermore, the handle mechanism includes a pilot pressure reducing valve assembly and an operating handle, wherein the pilot pressure reducing valve assembly is connected to the load-sensitive pump, and the operating handle is connected to the pilot pressure reducing valve assembly.

[0008] Furthermore, the main relief valve is an electro-hydraulic control relief valve. The input end of the main relief valve is connected to the oil outlet of the load-sensitive pump, and the output end of the main relief valve is connected to the oil tank. Its hydraulic control end is controlled by the feedback oil circuit of the main valve LS, and its electrical control end is controlled by the second controller.

[0009] Furthermore, the main valve LS feedback oil circuit is simultaneously connected to the load-sensitive pump feedback control port and the input terminal of the third pressure sensor, and the output terminal of the third pressure sensor is connected to the electrical control terminal of the main relief valve through the second controller.

[0010] Furthermore, the pilot pressure reducing valve assembly includes a setpoint pressure reducing valve.

[0011] Furthermore, each of the aforementioned working links is connected to an actuator.

[0012] Furthermore, the actuator includes a hydraulic cylinder and a hydraulic motor.

[0013] 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:

[0014] Acquire pressure signals detected by the first pressure sensor, the second pressure sensor, and the third pressure sensor;

[0015] The main relief valve is controlled based on the pressure signals detected by the first, second, and third pressure sensors.

[0016] Furthermore, the control of the main relief valve based on the pressure signals detected by the first pressure sensor, the second pressure sensor, and the third pressure sensor specifically includes:

[0017] If the third pressure sensor detects a pressure signal, it will not output an electrical signal to the main relief valve, thus de-energizing the main relief valve's electrical control terminal.

[0018] If the first or second pressure sensor detects a pressure signal, but the third pressure sensor does not detect a pressure signal, an electrical signal is output to the main relief valve, so that the electronic control terminal of the main relief valve is energized.

[0019] If none of the first, second, and third pressure sensors detect a pressure signal, no electrical signal will be output to the main relief valve.

[0020] Thirdly, the present invention provides an excavator including the electric slewing control system described in the first aspect.

[0021] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0022] This electric slewing control system detects signals from the first, second, and third pressure sensors and adjusts the pressure of the main relief valve. Based on the pressure feedback from the main valve LS to the load-sensitive pump, it ensures that the outlet pressure of the load-sensitive pump is greater than the set pressure of the pilot pressure reducing valve group in the handle mechanism during single slewing action and other actions. This ensures normal electric slewing action without increasing idle energy consumption and avoids situations where the speed of single slewing action slows down, vibrates, or even stops during compound action switching. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the system structure of an electric rotary control system according to an embodiment of the present invention.

[0024] In the diagram: 1. Oil tank; 2. Load-sensitive pump; 3. Main valve; 4. First pressure sensor; 5. Handle mechanism; 6. First controller; 7. Stick cylinder; 8. Boom cylinder; 9. Second pressure sensor; 10. Third pressure sensor; 11. Main relief valve; 12. Second controller; 13. Rotary motor. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0026] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances. Example 1:

[0028] like Figure 1As shown, this 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. The return oil from the load-sensitive pump 2, the main valve 3, and the handle mechanism 5 is all connected to the oil tank 1. The 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 primary coupling and multiple working couplings. The handle mechanism 5 includes multiple pilot output pressure ports, two of which are respectively equipped with a first pressure sensor 4 and a second pressure sensor 9. Both the first pressure sensor 4 and the second pressure sensor 9 are electrically connected to a first controller 6. The remaining pilot output pressure ports are connected to the control pilot side of each working coupling and are used to control the reversing of the working coupling. The first controller 6 is connected to a rotary motor 13. The system includes a main relief valve 11, the inlet of which is connected to the load-sensitive pump 2, the outlet of which is connected to the oil tank 1, and the hydraulic control terminal of which is connected to the feedback oil circuit of the main valve LS. The feedback oil circuit of the main valve LS is connected to the feedback control port of the load-sensitive pump 2 and also to the input terminal of the third pressure sensor 10. The electrical control terminals of the third pressure sensor 10 and the main relief 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 feedback oil circuit of the main valve LS is connected to both the feedback control port of the load-sensitive pump 2 and the input terminal of the third pressure sensor 10. The output terminal of the third pressure sensor 10 is connected to the electrical control terminal of the main relief valve 11 through the second controller 12.

[0029] like Figure 1 As shown in the figure, the pilot pressure reducing handle operation part is the handle mechanism 5, and the positions of pa1, pb1, pa2, and pb2 in the main valve 3 are the working links.

[0030] The handle mechanism 5 includes a pilot pressure reducing valve group and an operating handle. The pilot pressure reducing valve group is connected to the load-sensitive pump 2, and the operating handle is connected to the pilot pressure reducing valve group. The pilot pressure reducing valve group includes a set-value pressure reducing valve (a set-value pressure reducing valve: a hydraulic valve that reduces the input pressure P to a set value P0, requiring P≥P0; when P<P0, then P=P). In this patent, the pilot output pressure ports include 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. The remaining pilot output pressure 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 switching of the working links. Each working link is connected to an actuator. The actuator includes a hydraulic cylinder and a hydraulic motor. The hydraulic cylinder includes a stick cylinder 7 and a boom cylinder 8.

[0031] Specifically, during operation, the load-sensitive pump 2 draws oil from the oil tank 1, and its outlet oil path enters the handle mechanism 5, providing oil to the handle mechanism 5, and the main valve 3 supplies oil to the main oil path. In this patent, the stick cylinder 7 is set as the first working connection, the boom cylinder 8 is set as the second working connection, and other working connections should also be included. Regarding the hydraulic control part, when the operating handle is actuated, the handle mechanism 5 outputs pressure through the pilot output pressure oil port (e.g., pa1, pb1, pa2, pb2), which is connected to the corresponding pilot port of the main valve 3, pushing the main valve core to actuate, thereby realizing the extension and retraction of the stick cylinder 7 and the boom. The hydraulic cylinder 8 rotates in both directions. The first pressure sensor 4 and the second pressure sensor 9 are connected to the pilot output pressure ports pa0 / pb0, which control the rotation. pa0 / pb0 serves as the input; when the first pressure sensor 4 and the second pressure sensor 9 detect their pressure signals, they convert them into corresponding electrical signals and output them to the rotary motor 13 to control its left and right rotation. The input of the third pressure sensor 10 is connected to the LS hydraulic control signal fed back from the main valve 3 (i.e., the main valve LS feedback oil circuit), used to detect the maximum pressure between multiple working links. Its output is connected to the second controller 12. The main relief valve 11's electrical control section is also connected to the second controller 12. When performing a compound action, the third pressure sensor 10 detects the LS hydraulic control signal. The second controller 12 identifies and determines that no electrical signal is output to the main relief valve 11. At this time, the main relief valve 11's electrical control section is de-energized, ensuring that the maximum pressure of the main relief valve 11 does not exceed the set pressure, thus guaranteeing system safety. Furthermore, at this time, the outlet pressure of the load-sensitive pump 2 is greater than the set pressure of the pressure-reducing valve in the handle mechanism 5, ensuring stable pilot oil source output pressure. When performing a single rotary action, this... The outlet pressure of the load-sensitive pump 2 is the overflow pressure of the main relief valve 11. Since the third pressure sensor 10 has no input pressure signal, the second controller 12 identifies and judges the signal and outputs an electrical signal to the main relief valve 11. At this time, the electronic control part of the main relief valve 11 compresses the spring, so that its overflow pressure, i.e. the outlet pressure of the load-sensitive pump 2, is slightly greater than the set pressure of the pressure reducing valve in the handle mechanism 5, ensuring that the pilot oil source output pressure is stable. When the first pressure sensor 4, the second pressure sensor 9 and the third pressure sensor 10 have no pressure signal output, the machine is in a shutdown state and no relevant signals are issued by any control.

[0032] This patent utilizes a combination of a first pressure sensor 4, a second pressure sensor 9, and a 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. It identifies and distinguishes the operation of the rotary motor 13 from other hydraulic control operations. By changing the pressure of the main relief valve 11, and based on the adjustment characteristics of the load-sensitive pump 2 according to the LS pressure feedback of the main valve, it ensures that 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 under single rotary operation and other operations. Furthermore, it ensures normal electric rotary operation without increasing idle energy consumption, and avoids situations where the speed of single rotary operation slows down, vibrates, or even stops when switching between compound operations. Example 2:

[0033] This invention provides a slewing control method based on the electric slewing control system described in Embodiment 1, comprising the following steps:

[0034] The pressure signals detected by the first pressure sensor 4, the second pressure sensor 9, and the third pressure sensor 10 are acquired; the pressure signals can be used to determine the single rotation action and other related actions, and to control the electronic control terminal of the main relief valve 11.

[0035] The main relief valve 11 is controlled based on the pressure signals detected by the first pressure sensor 4, the second pressure sensor 9, and the third pressure sensor 10.

[0036] The control of the main relief valve 11 based on the pressure signals detected by the first pressure sensor 4, the second pressure sensor 9, and the third pressure sensor 10 specifically includes:

[0037] If the third pressure sensor 10 detects a pressure signal, it will 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 de-energized state.

[0038] 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, then an electrical signal is output to the main relief valve 11, so that the electrical control terminal of the main relief valve 11 is energized.

[0039] If none of the first pressure sensor 4, the second pressure sensor 9, and the third pressure sensor 10 detect a pressure signal, no electrical signal will be output to the main relief valve 11, and the excavator will be in an idling state. Example 3:

[0040] The present invention provides an excavator, including the electric slewing control system described in Embodiment 1.

[0041] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An electric rotary control system, characterized in that, The system includes a load-sensitive pump, a main valve, a handle mechanism, and an oil tank. The return oil from the load-sensitive pump, the main valve, and the handle mechanism is all connected to the oil tank. The outlet of the load-sensitive pump is connected to both the handle mechanism and the main valve. The main valve includes a primary coupling and multiple working couplings. The handle mechanism includes multiple pilot output pressure ports, two of which are respectively equipped with a first pressure sensor and a second pressure sensor. Both the first and second pressure sensors are electrically connected to a first controller. The remaining pilot output pressure ports are connected to the control pilot side of each working coupling and are used to control the reversing of the working couplings. The first controller is connected to a rotary motor. The first connection includes a main relief valve, the oil inlet of which is connected to the load-sensitive pump, the oil outlet of which is connected to the oil tank, the hydraulic control end of which is connected to the main valve LS feedback oil circuit, the main valve LS feedback oil circuit being connected to the feedback control port of the load-sensitive pump and also to the input end of the third pressure sensor, and both the third pressure sensor and the electrical control end of the main relief valve are electrically connected to the second controller.

2. The electric rotary control system according to claim 1, characterized in that, The handle mechanism includes a pilot pressure reducing valve assembly and an operating handle. The pilot pressure reducing valve assembly is connected to the load-sensitive pump, and the operating handle is connected to the pilot pressure reducing valve assembly.

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

4. The electric rotary control system according to claim 1, characterized in that, The main valve LS feedback oil circuit is connected to both the load-sensitive pump feedback control port and the input terminal of the third pressure sensor. The output terminal of the third pressure sensor is connected to the electrical control terminal of the main relief valve through the second controller.

5. The electric rotary control system according to claim 2, characterized in that, The pilot pressure reducing valve assembly includes a fixed-value pressure reducing valve.

6. The electric rotary control system according to claim 2, characterized in that, Each of the aforementioned work links is connected to an actuator.

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

8. An electric slewing control method, based on the electric slewing control system according to any one of claims 1 to 7, characterized in that, Includes 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 based on the pressure signals detected by the first, second, and third pressure sensors.

9. The electric slewing control method according to claim 8, characterized in that, The control of the main relief valve based on 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, it will not output an electrical signal to the main relief valve, thus de-energizing the main relief valve's electrical control terminal. If the first or second pressure sensor detects a pressure signal, but the third pressure sensor does not detect a pressure signal, an electrical signal is output to the main relief valve, so that the electronic control terminal of the main relief valve is energized. If none of the first, second, and third pressure sensors detect a pressure signal, no electrical signal will be output to the main relief valve.

10. An excavator, characterized in that, Includes the electric rotary control system as described in any one of claims 1 to 7.

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