Method, device and excavator for controlling lowering of excavator boom

Abstract

The present application relates to the technical field of excavators, and discloses a method and device for controlling the lowering of an excavator arm and an excavator. When it is determined that the arm pilot handle is rapidly switched back to the neutral position, the displacement of the oil pump supplying oil to the arm cylinder is reduced, the oil inflow of the rod cavity of the arm cylinder is reduced, the lowering speed of the arm is reduced, and the impact at the moment when the arm stops moving is reduced. During the process of reducing the current of the arm main control valve and switching the arm main control valve to the neutral position, the rod cavity of the arm cylinder is supplied with oil, the rodless cavity of the arm cylinder returns oil, the current change rate of the arm main control valve is increased, the moving speed of the valve core of the arm main control valve is increased, the oil inflow of the rod cavity of the arm cylinder is reduced, the oil return of the rodless cavity of the arm cylinder is reduced, the moving speed of the piston rod of the arm cylinder is reduced, the impact at the moment when the arm stops moving is reduced, and the driving experience is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of excavators, and in particular to a method and device for controlling the lowering of an arm of an excavator and an excavator. BACKGROUND

[0002] The excavator comprises an arm, an arm master valve and an arm pilot handle. The driver controls the operation of the arm pilot handle to adjust the handle pilot pressure, adjusts the current of the arm master valve according to the handle pilot pressure, switches the state of the arm master valve, and realizes the raising, lowering and maintaining of the arm.

[0003] During the lowering of the arm by the driver operating the arm pilot handle, if the driver suddenly releases the arm pilot handle, i.e. the arm pilot handle is suddenly released, the arm pilot handle will quickly return to the neutral position under the action of the elastic member, the handle pilot pressure will rapidly decrease, and the arm will rapidly lower, which will cause a large impact when the arm pilot handle returns to the neutral position. In addition, when the driver actively switches the arm pilot handle to the neutral position, if the switching speed of the arm pilot handle is too fast, a large impact will also occur when the arm pilot handle returns to the neutral position.

[0004] Therefore, the prior art proposes to reduce the flow of the oil pump supplying oil to the arm master valve to slow down the retraction speed of the piston rod of the arm cylinder during the lowering of the arm and the rapid switching of the arm pilot handle to the neutral position, so as to reduce the impact of the arm. Although this method can alleviate the impact of the arm to a certain extent during the lowering of the arm, it is found in actual application that a large impact still exists when the arm stops, which affects the driving experience of the machine.

[0005] Therefore, there is an urgent need for a method for controlling the lowering of the arm of an excavator to solve the above technical problems. SUMMARY

[0006] The present application aims to provide a method and device for controlling the lowering of the arm of an excavator and an excavator, which can reduce the impact of the arm when the arm pilot handle quickly returns to the neutral position and improve the driving experience of the excavator.

[0007] To achieve this purpose, the present application adopts the following technical solutions:

[0008] The method for controlling the lowering of the arm of an excavator comprises:

[0009] During the lowering of the arm, it is determined whether the arm pilot handle has been rapidly switched to the neutral position according to the change in the handle pilot pressure generated by the operation of the arm pilot handle;

[0010] If it is determined that the boom pilot handle is rapidly returned to the neutral position, the displacement of the oil pump supplying oil to the boom cylinder is reduced, and the current of the boom master valve is reduced and the rate of change of the current of the boom master valve is increased.

[0011] As a preferred technical solution of the method for controlling the lowering of the boom of the excavator, whether the boom pilot handle is rapidly returned to the neutral position is determined according to the change of the handle pilot pressure generated by the operation of the boom pilot handle, comprising:

[0012] The handle pilot pressure is determined according to the position of the boom pilot handle, and when the handle pilot pressure is reduced and the absolute value of the change amount of the handle pilot pressure at the adjacent time exceeds the preset handle pilot pressure change amount, it is determined that the boom pilot handle is rapidly returned to the neutral position.

[0013] As a preferred technical solution of the method for controlling the lowering of the boom of the excavator, the displacement of the oil pump supplying oil to the boom cylinder is reduced, comprising:

[0014] A first current change rate of the oil pump corresponding to the condition that the boom pilot handle is rapidly returned to the neutral position is determined, and the current of the oil pump is reduced according to the first current change rate to reduce the displacement of the oil pump.

[0015] As a preferred technical solution of the method for controlling the lowering of the boom of the excavator, further comprising:

[0016] When the boom pilot handle is not rapidly returned to the neutral position and the boom handle is controlled to lower, a second current change rate of the oil pump corresponding to the condition that the boom pilot handle is not rapidly returned to the neutral position is determined, and the current of the oil pump is reduced according to the second current change rate to reduce the displacement of the oil pump.

[0017] The first current change rate is greater than the second current change rate.

[0018] As a preferred technical solution of the method for controlling the lowering of the boom of the excavator, when the current of the oil pump is reduced according to the first current change rate or the second current change rate, the current of the oil pump is reduced to the required current of the oil pump.

[0019] The required current of the oil pump is obtained according to the following steps:

[0020] The required flow Q of the boom lowering is determined according to the handle pilot pressure 需求 ;

[0021] The sum of the required flow Q of the other executing components supplied by the same oil pump of the boom is determined 其他 ;

[0022] determining a total required flow rate Q of the oil pump for supplying oil to the boom cylinder 总 , Q 总 = Q 需求 + Q 其他 ;

[0023] determining a total required displacement of the oil pump for supplying oil to the boom cylinder according to the total required flow rate;

[0024] determining a required current of the oil pump according to the total required displacement.

[0025] As a preferred technical solution of the above method for controlling the lowering of the boom of the excavator, the current of the boom master valve is reduced, comprising:

[0026] determining a required current of the boom master valve according to the handle pilot pressure;

[0027] determining a theoretical current change rate of the boom master valve, correcting the determined theoretical current change rate of the boom master valve to obtain a corrected current change rate, the corrected current change rate being greater than the theoretical current change rate;

[0028] adjusting the current of the boom master valve according to the corrected current change rate, so that the current of the boom master valve reaches the required current of the boom master valve.

[0029] As a preferred technical solution of the above method for controlling the lowering of the boom of the excavator, the correcting of the determined theoretical current change rate of the boom master valve to obtain a corrected current change rate comprises:

[0030] determining a current change rate correction coefficient according to the handle pilot pressure, the handle pilot pressure being inversely proportional to the current change rate correction coefficient;

[0031] calculating the corrected current change rate according to the current change rate correction coefficient, corrected current change rate = current change rate correction coefficient x theoretical current change rate.

[0032] As a preferred technical solution of the above method for controlling the lowering of the boom of the excavator, further comprising:

[0033] when the boom pilot handle does not quickly cut back to the neutral position, reducing the current of the boom master valve according to the theoretical current change rate, so that the current of the boom master valve reaches the required current of the boom master valve.

[0034] In order to achieve the above-mentioned purpose, the present application also provides a control device for the lowering of the boom of the excavator, which is used to implement the method for controlling the lowering of the boom of the excavator according to any one of the above-mentioned solutions, and the control device for the lowering of the boom of the excavator comprises:

[0035] a fast return to neutral position determining module, configured to determine whether the boom pilot handle has a fast return to neutral position according to a change in the handle pilot pressure generated by the boom pilot handle action during the boom lowering process;

[0036] an oil pump displacement adjusting module, configured to reduce the displacement of the oil pump supplying oil to the boom cylinder when the fast return to neutral position determining module determines that the boom pilot handle has a fast return to neutral position;

[0037] a boom master valve control module, configured to reduce the current of the boom master valve and increase the current change rate of the boom master valve when the fast return to neutral position determining module determines that the boom pilot handle has a fast return to neutral position.

[0038] To achieve the above-mentioned purpose, the application further provides a control device for boom lowering of a excavator.

[0039] The application has the following advantages: the method, device and excavator for controlling boom lowering of a excavator provided by the application can reduce the displacement of the oil pump supplying oil to the boom cylinder when the boom pilot handle has a fast return to neutral position, thereby reducing the oil inflow of the rod cavity of the boom cylinder and the boom lowering speed to reduce the impact at the moment when the boom stops moving; the boom master valve is switched to the neutral position by reducing the current of the boom master valve, so that the state of the boom master valve corresponds to the position of the boom pilot handle; during the process of switching the boom master valve to the neutral position by reducing the current of the boom master valve, the rod cavity of the boom cylinder is supplied with oil, the rod cavity of the boom cylinder is returned with oil, the moving speed of the valve core of the boom master valve is increased by increasing the current change rate of the boom master valve, the oil inflow of the rod cavity of the boom cylinder is reduced, the oil return of the rod cavity of the boom cylinder is reduced, the moving speed of the piston rod of the boom cylinder is reduced, thereby reducing the impact at the moment when the boom stops moving and improving the driving experience. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the application. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can be obtained from the contents of the embodiments of the application and the drawings without creative labor.

[0041] Figure 1 is the main flow chart of the method for controlling boom lowering of a excavator provided by the embodiments of the application;

[0042] Figure 2is a detailed flowchart of the method for controlling the lowering of the boom of the excavator provided by the embodiment of the present application. DETAILED DESCRIPTION

[0043] The present application will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely intended for the purpose of interpretation of the present application and are not limiting of the present application. In addition, it should be noted that only the parts related to the present application are shown in the accompanying drawings for the purpose of description, rather than all the structures.

[0044] In the description of the present application, unless explicitly defined and limited otherwise, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0045] In the present application, unless explicitly defined and limited otherwise, the "upper" or "lower" of the first feature to the second feature can include the direct contact of the first and second features, or the contact of the first and second features through another feature between them. Moreover, the "upper", "upper" and "upper" of the first feature to the second feature includes the vertical direction of the first feature above and oblique above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "lower", "lower" and "lower" of the first feature to the second feature includes the vertical direction of the first feature below and oblique below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0046] In the description of the present embodiment, the terms "upper", "lower", "right", etc. orientation or position relationship is based on the orientation or position relationship shown in the drawings, only for the purpose of description and simplification of operation, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second" are only used to distinguish in the description, and have no special meaning.

[0047] The present embodiment provides a method for controlling the lowering of the boom of the excavator, mainly for the excavator with the boom master valve as the electromagnetic valve, to reduce the impact in the process of lowering the boom and improve the driving experience.

[0048] Figure 1 is the main flowchart of the method for controlling the lowering of the boom of the excavator provided by the embodiment of the present application, as shown in Figure 1 The method for controlling the lowering of the boom of the excavator comprises the following steps:

[0049] S1, determining whether the boom pilot handle is in a situation of rapid return to the neutral position according to a change of the handle pilot pressure generated by an action of the boom pilot handle during the boom lowering process;

[0050] S2, if it is determined that the boom pilot handle is in the situation of rapid return to the neutral position, adjusting a displacement of an oil pump for supplying oil to the boom cylinder to reduce the displacement of the oil pump, and reducing an electric current of the boom master valve and increasing a change rate of the electric current of the boom master valve.

[0051] The boom pilot handle has a neutral position and a lowering position. When the boom pilot handle is in the neutral position, the handle pilot pressure is zero, the boom master valve is in the neutral position, and the boom is maintained in the current state. When the boom pilot handle is switched from the neutral position to the lowering position, the boom master valve is switched from the neutral position to the boom lowering position, and the boom is lowered. When the boom pilot handle is switched from the boom lowering position to the neutral position, the boom master valve is switched from the boom lowering position to the neutral position, and the boom is lowered. During the boom lowering, the rod cavity of the boom cylinder is supplied with oil and the rodless cavity of the boom cylinder returns oil, so that the piston rod of the boom cylinder is retracted. It should be noted that the rod cavity of the boom cylinder is the so-called boom small cavity in the field of excavators, and the rodless cavity of the boom cylinder is the so-called boom large cavity in the field of excavators.

[0052] When the operator accidentally releases the boom pilot handle, the boom pilot handle will quickly return to the neutral position under the action of the elastic return member, i.e., the boom pilot handle is in the situation of rapid return to the neutral position. During this process, the handle pilot pressure rapidly decreases, and therefore, the situation of rapid return to the neutral position of the boom pilot handle can be determined based on the change of the handle pilot pressure. Specifically, the handle pilot pressure is determined according to the position of the boom pilot handle, and when the handle pilot pressure decreases and the absolute value of the change of the handle pilot pressure at adjacent time exceeds a preset handle pilot pressure change, it is determined that the boom pilot handle is in the situation of rapid return to the neutral position. The preset handle pilot pressure change can be determined through repeated tests, and is not specifically limited herein.

[0053] In other embodiments, the moving speed of the boom pilot handle can also be detected by a displacement detection unit such as a displacement sensor. When the absolute value of the displacement of the boom pilot handle at adjacent time exceeds a preset displacement and the boom pilot handle moves from the lowering position to the neutral position, it is determined that the boom pilot handle is in the situation of rapid return to the neutral position.

[0054] In the case of determining that the boom pilot handle is quickly switched to the neutral position, the oil pump supplying oil to the boom cylinder is reduced in displacement to reduce the oil inflow of the rod cavity of the boom cylinder while ensuring the boom to descend, so as to reduce the boom descending speed and reduce the impact when the boom stops moving. The boom master valve is switched to the neutral position by reducing the current of the boom master valve, so that the state of the boom master valve corresponds to the position of the boom pilot handle. In the process of switching the boom master valve to the neutral position by reducing the current of the boom master valve, the rod cavity of the boom cylinder is supplied with oil, the rod cavity of the boom cylinder is returned with oil, the moving speed of the valve core of the boom master valve is increased by increasing the current change rate of the boom master valve, the oil inflow of the rod cavity of the boom cylinder is reduced, the oil return of the rod cavity of the boom cylinder is reduced, so as to slow down the moving speed of the piston rod of the boom cylinder, thereby reducing the impact when the boom stops moving and improving the driving experience.

[0055] Further, the reducing the displacement of the oil pump supplying oil to the boom cylinder comprises:

[0056] The first current change rate of the oil pump corresponding to the working condition of the boom pilot handle being quickly switched to the neutral position is determined, and the current of the oil pump is reduced according to the first current change rate to reduce the displacement of the oil pump.

[0057] In this way, the current of the oil pump can quickly respond when the boom pilot handle is quickly switched to the neutral position, the displacement of the oil pump is reduced, the oil inflow of the rod cavity of the boom cylinder is reduced, the descending speed of the boom is slowed down, and the impact when the boom stops moving is reduced.

[0058] Specifically, the speed of the engine suddenly fluctuates, the outlet oil pressure of the oil pump suddenly fluctuates, and other monitoring conditions need to adjust the current of the oil pump, and the current change rate of the oil pump is different under different monitoring conditions. Therefore, the first current change rate of the oil pump can be obtained in the following way: the corresponding relationship between the monitoring conditions and the current change rate of the oil pump is pre-stored, such as a table, and when the boom pilot handle is quickly switched to the neutral position, the corresponding current change rate of the oil pump is queried based on the pre-stored corresponding relationship between the monitoring conditions and the current change rate of the oil pump, and the queried current change rate of the oil pump is the first current change rate.

[0059] The current of the oil pump directly affects the displacement of the oil pump, and the current of the oil pump and the displacement of the oil pump are one-to-one corresponding, so the displacement of the oil pump can be adjusted by adjusting the current of the oil pump.

[0060] Further, the method for controlling the boom of the excavator to descend further comprises:

[0061] In the process of controlling the boom handle to descend, when the boom pilot handle does not quickly cut back to the neutral position, a second current change rate of the oil pump corresponding to the working condition that the boom pilot handle does not quickly cut back to the neutral position is determined, and the current of the oil pump is reduced according to the second current change rate, so as to reduce the displacement of the oil pump.

[0062] The first current change rate is greater than the second current change rate.

[0063] The second current change rate of the oil pump can be obtained in the following manner: a corresponding relationship between the monitoring working condition and the current change rate of the oil pump is pre-stored, when it is determined that the boom pilot handle does not quickly cut back to the neutral position, the current change rate of the oil pump corresponding to the monitoring working condition that the boom pilot handle does not quickly cut back to the neutral position is queried based on the pre-stored corresponding relationship between the monitoring working condition and the current change rate of the oil pump, and the queried current change rate of the oil pump is the second current change rate.

[0064] Optionally, the current of the oil pump is reduced to the required current of the oil pump according to the first current change rate or the second current change rate.

[0065] The required current of the oil pump is obtained in the following steps:

[0066] The required flow Q of the boom descending is determined according to the handle pilot pressure 需求 ;

[0067] The total flow Q required by other executing components supplied with oil by the same oil pump as the boom is determined 其他 ;

[0068] The total required flow Q of the oil pump for supplying oil to the boom cylinder is determined 总 , Q 总 = Q 需求 + Q 其他 ;

[0069] The total required displacement of the oil pump for supplying oil to the boom cylinder is determined according to the total required flow;

[0070] The required current of the oil pump is determined according to the total required displacement.

[0071] The handle pilot pressure is proportional to the flow of the oil pump, and the greater the handle pilot pressure, the greater the required flow of the oil pump. The handle pilot pressure and the position of the boom pilot handle are one-to-one corresponding, and the corresponding relationship between the position of the boom pilot handle and the handle pilot pressure can be pre-stored, such as a map or a data table, and the handle pilot pressure corresponding to the current position of the boom pilot handle is queried. The corresponding relationship between the position of the boom pilot handle and the handle pilot pressure can be obtained through repeated experiments, and how to obtain the current position of the boom pilot handle is prior art in the field, which will not be specifically introduced here.

[0072] The handle pilot pressure and the required flow of the boom lowering are one-to-one corresponding, and the corresponding relationship between the handle pilot pressure and the required flow of the boom lowering can be pre-stored, such as a map or a data table, and the required flow of the boom lowering corresponding to the handle pilot pressure is queried. The corresponding relationship between the handle pilot pressure and the required flow of the boom lowering can be obtained through repeated experiments.

[0073] How to obtain the flow required by any other actuating component supplied with oil by the same oil pump as the boom is prior art in the field, which will not be specifically introduced here.

[0074] The total required flow and the total required displacement of the oil pump for supplying oil to the boom cylinder are one-to-one corresponding and positively correlated, and how to calculate the displacement of the oil pump according to the required flow of the oil pump is prior art in the field, such as pre-storing the corresponding relationship between the total required flow of the oil pump for supplying oil to the boom cylinder and the total required displacement of the oil pump for supplying oil to the boom cylinder, such as a map or a data table, and querying the total required displacement of the oil pump corresponding to the current total required flow. The corresponding relationship between the total required flow of the oil pump for supplying oil to the boom cylinder and the total required displacement of the oil pump for supplying oil to the boom cylinder can be obtained through repeated experiments, or can be calculated through the calculation formula between the flow of the oil pump and the displacement of the oil pump in the prior art to obtain the total required displacement of the oil pump.

[0075] In the normal working process, the displacement of the oil pump and the current of the oil pump are one-to-one corresponding and positively correlated, and when the required current of the oil pump is determined according to the total required displacement, the corresponding relationship between the total required displacement of the oil pump and the required current of the oil pump can be pre-stored, such as a data table, and the required current of the oil pump corresponding to the current total required displacement of the oil pump is queried. The corresponding relationship between the total required displacement of the oil pump and the required current of the oil pump can be obtained through repeated experiments.

[0076] Further, the method for controlling the boom lowering of the excavator, the current of the boom master valve is reduced, comprising:

[0077] The required current of the boom master valve is determined according to the handle pilot pressure;

[0078] Determine the theoretical current rate of change of the boom master valve, correct the determined theoretical current rate of change of the boom master valve to obtain a corrected current rate of change, and the corrected current rate of change is greater than the theoretical current rate of change;

[0079] Adjust the current of the boom master valve according to the corrected current rate of change, so that the current of the boom master valve reaches the required current of the boom master valve.

[0080] Wherein, the handle pilot pressure and the required current of the boom master valve are one-to-one corresponding and proportional, and the oil inlet and oil return amount of the boom cylinder is controlled by adjusting the current of the boom master valve. The corresponding relationship between the handle pilot pressure and the required current of the boom master valve can be pre-stored, such as a data table, and the required current of the boom master valve corresponding to the current handle pilot pressure is queried. The corresponding relationship between the handle pilot pressure and the required current of the boom master valve can be obtained through repeated tests.

[0081] Optionally, the determined theoretical current rate of change of the boom master valve is corrected to obtain a corrected current rate of change, comprising:

[0082] Determine the current rate of change correction coefficient according to the handle pilot pressure, and the handle pilot pressure is inversely proportional to the current rate of change correction coefficient;

[0083] Calculate the corrected current rate of change according to the current rate of change correction coefficient, and the corrected current rate of change = current rate of change correction coefficient x theoretical current rate of change.

[0084] Wherein, when the boom pilot handle quickly switches to the middle position, the handle pilot pressure and the current rate of change correction coefficient are one-to-one corresponding, the smaller the handle pilot pressure, the greater the current rate of change correction coefficient, which is conducive to realizing the moving speed of the valve core of the boom master valve in the boom pilot reset process, reducing the pressure difference between the rodless cavity and the rod cavity of the boom cylinder in the process of the boom master valve returning to the middle position, thereby reducing the impact at the moment when the boom stops moving, improving the driving experience; According to the driving style of the driver, the current and current rate of change of the boom master valve can be adjusted according to the switching speed of the boom pilot handle from the descending position to the middle position, so as to achieve the purpose of reducing the impact at the moment when the boom stops moving.

[0085] Further, the method for controlling the boom of the excavator to descend further comprises:

[0086] When the boom pilot handle does not occur the fast cutback to the neutral position, the current of the boom master valve is reduced according to the theoretical current change rate, so that the current of the boom master valve reaches the demand current of the boom master valve. In this way, when the boom is descending and the boom pilot handle does not occur the fast cutback to the neutral position, the current of the boom master valve is reduced according to the theoretical current change rate; when the boom is descending and the boom pilot handle occurs the fast cutback to the neutral position, the current of the boom master valve is reduced according to the modified current change rate greater than the theoretical current change rate, so that the current of the boom master valve is rapidly reduced synchronously when the pilot pressure is rapidly reduced.

[0087] The theoretical current change rate is a known determined value, which can be determined through repeated tests, and is not limited here.

[0088] Figure 2 is a detailed flowchart of the method for controlling the boom lowering of the excavator provided by the embodiment, and the method for controlling the boom lowering of the excavator will be described in detail below Figure 2 The method for controlling the boom lowering of the excavator is described in detail. The method for controlling the boom lowering of the excavator includes the following steps:

[0089] S10, during the boom lowering, determining whether the boom pilot handle occurs the fast cutback to the neutral position according to the handle pilot pressure change generated by the boom pilot handle action; if yes, performing S20 and S30, and if no, performing S40 and S50;

[0090] S20, determining the first current change rate of the oil pump corresponding to the working condition that the boom pilot handle occurs the fast cutback to the neutral position, and reducing the current of the oil pump according to the first current change rate to reduce the displacement of the oil pump;

[0091] S30, determining the demand current of the boom master valve according to the handle pilot pressure; determining the theoretical current change rate of the boom master valve, modifying the determined theoretical current change rate of the boom master valve to obtain a modified current change rate; and adjusting the current of the boom master valve according to the modified current change rate, so that the current of the boom master valve reaches the demand current of the boom master valve;

[0092] S40, determining the second current change rate of the oil pump corresponding to the working condition that the boom pilot handle does not occur the fast cutback to the neutral position, and reducing the current of the oil pump according to the second current change rate to reduce the displacement of the oil pump;

[0093] S50, determining the demand current of the boom master valve according to the handle pilot pressure; determining the theoretical current change rate of the boom master valve; and reducing the current of the boom master valve according to the theoretical current change rate, so that the current of the boom master valve reaches the demand current of the boom master valve.

[0094] The embodiment also provides a control device for excavator boom lowering, which is used to implement the method for controlling excavator boom lowering, and comprises a quick return to neutral position determination module, an oil pump displacement adjustment module and a boom master valve control module.

[0095] The control device for excavator boom lowering has the same beneficial effects as the method for controlling excavator boom lowering, and thus will not be described in detail.

[0096] The embodiment also provides an excavator comprising the control device for excavator boom lowering.

[0097] In addition, the above are only preferred embodiments of the present application and the applied technical principles. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the scope of the present application. Therefore, although the present application has been described in detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A method for controlling the descent of an excavator boom, characterized in that, include: During boom descent, the change in boom pilot pressure caused by the action of the boom pilot handle determines whether the boom pilot handle has rapidly returned to the neutral position. If it is determined that the boom pilot handle has rapidly switched back to the neutral position, then the displacement of the oil pump supplying oil to the boom cylinder is reduced, the current of the boom main control valve is reduced, and the current change rate of the boom main control valve is increased. Determine whether the boom pilot handle has rapidly returned to the neutral position based on the change in pilot pressure generated by the movement of the boom pilot handle, including: The boom pilot handle is determined based on its position. When the boom pilot handle decreases and the absolute value of the change in the boom pilot handle at adjacent moments exceeds the preset change in the boom pilot handle, it is determined that the boom pilot handle has rapidly returned to the neutral position. Reducing the displacement of the oil pump supplying oil to the boom cylinder includes: Determine the first current change rate of the oil pump corresponding to the working condition where the boom pilot handle is quickly switched back to the neutral position, and reduce the current of the oil pump according to the first current change rate to reduce the displacement of the oil pump. Reduce the current to the boom control valve, including: The required current of the boom main control valve is determined based on the pilot pressure of the handle. The theoretical current change rate of the boom main control valve is determined, and the determined theoretical current change rate of the boom main control valve is corrected to obtain a corrected current change rate, which is greater than the theoretical current change rate. Adjust the current of the boom main control valve according to the corrected current change rate so that the current of the boom main control valve reaches the required current of the boom main control valve.

2. The method for controlling the descent of an excavator boom according to claim 1, characterized in that, Also includes: When the boom pilot handle does not quickly return to the neutral position and the boom handle is controlled to descend, the second current change rate of the oil pump corresponding to the working condition where the boom pilot handle does not quickly return to the neutral position is determined, and the current of the oil pump is reduced according to the second current change rate to reduce the displacement of the oil pump. The first current change rate is greater than the second current change rate.

3. The method for controlling the descent of an excavator boom according to claim 2, characterized in that, When the current of the oil pump is reduced according to the first rate of change of current, or when the current of the oil pump is reduced according to the second rate of change of current, the current of the oil pump is reduced to the required current of the oil pump. The required current for the oil pump is obtained according to the following steps: The required flow rate Q for boom descent is determined based on the pilot pressure of the handle. 需求 ; Determine the total flow rate Q required for other actuators that are supplied with oil by the same pump as the boom. 其他 ; The total required flow rate Q of the oil pump supplying oil to the boom cylinder is determined. 总 Q 总 =Q 需求 +Q 其他 ; The total required displacement of the oil pump supplying oil to the boom cylinder is determined based on the total required flow rate. The required current of the oil pump is determined based on the total required displacement.

4. The method for controlling the descent of an excavator boom according to claim 1, characterized in that, The corrected current change rate is obtained by correcting the theoretical current change rate of the boom master control valve, including: The current change rate correction coefficient is determined based on the handle pilot pressure, and the handle pilot pressure is inversely proportional to the current change rate correction coefficient. The corrected current change rate is calculated based on the current change rate correction factor, where the corrected current change rate = current change rate correction factor × theoretical current change rate.

5. The method for controlling the descent of an excavator boom according to claim 1, characterized in that, Also includes: When the boom pilot handle does not quickly return to the neutral position, the current of the boom main control valve is reduced according to the theoretical current change rate, so that the current of the boom main control valve reaches the required current of the boom main control valve.

6. A control device for lowering an excavator boom, characterized in that, For implementing the method for controlling the lowering of an excavator boom according to any one of claims 1 to 5, the control device for lowering the excavator boom comprises: The quick return to neutral position determination module is used to determine whether the boom pilot handle has quickly returned to the neutral position during the boom descent process, based on the change in pilot pressure generated by the action of the boom pilot handle. The oil pump displacement adjustment module is used to reduce the displacement of the oil pump supplying oil to the boom cylinder when the rapid return to the neutral position determination module determines that the boom pilot handle has rapidly returned to the neutral position. The boom main control valve control module is used to reduce the current of the boom main control valve and increase the current change rate of the boom main control valve when the rapid return to the neutral position determination module determines that the boom pilot handle has rapidly returned to the neutral position.

7. An excavator, characterized in that, Includes the control device for lowering the excavator boom as described in claim 6.

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