Excavator rotation auxiliary braking hydraulic circuit and control method

Abstract

The invention relates to an excavator rotation auxiliary braking hydraulic circuit and a control method, and the excavator rotation auxiliary braking hydraulic circuit comprises a rotation system module, an energy accumulator oil supplementing system module, an execution module and a control module; the rotary system module comprises a rotary motor, a first pressure sensor, a second pressure sensor, a main valve, a hydraulic pump set and a brake valve set. The energy accumulator oil supplementing system module comprises an energy accumulator, a third pressure sensor and an energy accumulator oil supplementing valve set. The execution module comprises a brake oil cylinder, the energy accumulator provides brake working pressure for the brake oil cylinder, and the energy accumulator drives the brake oil cylinder through the brake valve set. The control module comprises a handle and a controller, and the controller receives signals of the handle and signals of the first pressure sensor, the second pressure sensor and the third pressure sensor and controls the brake valve set and the energy accumulator oil supplementing valve set to act.

Description

Technical Field

[0001] This application relates to the field of engineering machinery technology, and more specifically, to a hydraulic circuit and control method for the swing auxiliary braking of an excavator. Background Technology

[0002] With the development of the construction machinery industry, excavators, as multi-functional and multi-purpose construction machinery, are often modified into special equipment for special working conditions, such as crawler cranes and rotary drilling rigs. These special-purpose excavators have higher requirements for swing parking brakes, so it is necessary to add an additional swing parking brake mechanism at the swing point.

[0003] Some existing technologies include locking the rotary platform by means of a fixed pin and an external gear ring. Others involve locking the drill bit of the rotary drilling rig by means of the friction between a brake and a brake disc.

[0004] However, the aforementioned technology can only lock the rotary mechanism at a specific position where the clearance of the external gear ring is aligned with the fixed pin, which cannot meet the need for locking in the working position under certain working conditions.

[0005] Furthermore, because it is a discontinuous gear structure and can only lock at a precise position, it requires multiple position sensors and a complex detection and control system, which increases the complexity of the system and reduces the reliability of the system operation.

[0006] When performing the locking action, the operator needs to adjust the rotation angle multiple times to achieve the accurate locking position.

[0007] When the locking is released, under conditions of high rotational braking force, the retaining pin will be subjected to a large lateral force, which may cause the retaining pin to jam and make it difficult to release. Summary of the Invention

[0008] The purpose of this application is to provide a hydraulic circuit and control method for the auxiliary braking of excavator swing, which can solve the problems of the existing technology, such as the locking mechanism not being able to lock at any angle, the complex control system, and the low reliability of unlocking.

[0009] To achieve the above objectives, in a first aspect, the present invention provides a hydraulic circuit for an excavator's slewing auxiliary braking, comprising: a slewing system module, an accumulator oil replenishment system module, an execution module, and a control module; The rotary system module includes a rotary motor, a first pressure sensor and a second pressure sensor for detecting the pressure on both sides of the rotary motor, a main valve for controlling the operation of the rotary motor, a hydraulic pump group for supplying oil to the main valve, and a brake valve group for controlling the opening and closing of the brake. The accumulator oil replenishment system module includes an accumulator, a third pressure sensor for detecting the pressure of the accumulator, and an accumulator oil replenishment valve group, which is connected between the cooling pump and the accumulator. The execution module includes a brake cylinder, the accumulator provides braking working pressure to the brake cylinder, and the accumulator drives the brake cylinder through the brake valve group; The control module includes a handle and a controller. The controller receives signals from the handle, as well as signals from the first pressure sensor, the second pressure sensor, and the third pressure sensor, and controls the operation of the brake valve assembly and the accumulator replenishment valve assembly.

[0010] In an optional embodiment, the brake valve assembly includes a normally open brake valve assembly. When the brake valve assembly receives a signal, it connects the brake cylinder and the hydraulic tank to release the brake. When the brake valve assembly does not receive a signal, it connects the brake cylinder and the accumulator to apply the brake.

[0011] In an optional embodiment, the brake valve assembly includes a solenoid cone valve with a leakage rate of no more than 5 drops / minute.

[0012] In an optional embodiment, the brake valve assembly further includes a variable throttle valve disposed in the brake oil circuit, the variable throttle valve being used to regulate the flow rate into and out of the brake cylinder.

[0013] In an optional implementation, a heat dissipation module is also included, which includes a cooling motor and a cooling fan; The cooling pump includes an electro-proportional pressure pump and is capable of maintaining a constant flow rate of oil to the cooling motor.

[0014] Secondly, the present invention provides a control method for the hydraulic circuit of the excavator's swing auxiliary braking as described in any of the foregoing embodiments, which is executed by the controller and includes accumulator pressure maintenance control and swing braking logic control.

[0015] In an optional implementation, the accumulator pressure maintenance control includes: when the third pressure sensor detects that the accumulator pressure is lower than the first preset pressure P0, the controller controls the accumulator oil replenishment valve group to open, and the cooling pump replenishes oil to the accumulator. When the accumulator pressure reaches a second preset pressure P1 higher than P0, the controller controls the accumulator oil replenishment valve group to close and stop oil replenishment. In an optional implementation, the slewing brake logic control includes a brake release condition: when the handle sends a slewing operation signal, the controller controls the brake valve group to receive the signal and release the slewing brake.

[0016] In an optional implementation, the slewing braking logic control includes a first braking trigger condition: when there is no slewing operation signal on the handle and the pressure difference detected by the first pressure sensor and the second pressure sensor is less than a preset threshold ΔP, it is determined that the slewing motor has stopped, and the brake valve group implements slewing braking when no signal is received. The preset threshold ΔP is 0.8-1.2 MPa.

[0017] In an optional implementation, the slewing braking logic control includes a second braking trigger condition: when the duration of no slewing operation signal on the handle reaches a preset time T, the brake valve group implements slewing braking in the state of not receiving a signal; The preset time T is 3-5 seconds.

[0018] The excavator slewing auxiliary braking hydraulic circuit and control method in this application can achieve reliable braking of the slewing mechanism at any angle.

[0019] By detecting the pressure difference on both sides of the rotary motor and the handle signal, the rotation status is automatically determined, achieving smooth braking and rapid release.

[0020] The system can maintain braking for more than 30 minutes after the main pump stops, relying on the accumulator, which is suitable for long-term parking needs under special working conditions.

[0021] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the hydraulic circuit for the slewing auxiliary brake in this application; Figure 2 This is a schematic diagram of the brake valve assembly of this application; Figure 3 This is a schematic diagram of the accumulator oil replenishment valve assembly of this application; Figure 4 This is a schematic diagram of the main valve structure of this application; Figure 5 This is a schematic diagram of the accumulator pressure maintenance control process in this application; Figure 6 This is a flowchart illustrating the slewing braking logic control of this application; Figure 7This is a schematic diagram of the braking mechanism of this application.

[0024] icon: 1-Slewing bearing; 2-Brake disc; 3-Brake; 4-Brake base; 5-Brake valve assembly; 6-Accumulator; 7-Third pressure sensor; 8-Handle; 9-Controller; 10-Slewing motor; 11-First pressure sensor; 12-Second pressure sensor; 13-Main valve; 14-Pilot pump; 15-Main pump; 16-Cooling pump; 17-Cooling motor; 18-Cooling fan; 19-Accumulator replenishing valve assembly; 191-Proportional pressure reducing valve; 192-Servo valve core; 193-Proportional control valve; 20-Brake cylinder. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] In the description of this application, it should be noted that the terms "inner" and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and for 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. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0027] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "setup" and "connection" 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 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 can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0028] See Figure 1 and combined Figures 2-4 The excavator swing auxiliary braking hydraulic circuit in this application mainly includes: a swing system module, an accumulator 6 oil replenishment system module, an execution module, and a control module.

[0029] The slewing system module includes a slewing motor 10, a first pressure sensor 11 and a second pressure sensor 12 for detecting the pressure on both sides of the slewing motor 10, a main valve 13 for controlling the operation of the slewing motor 10, a hydraulic pump assembly for supplying oil to the main valve 13, and a brake valve assembly 5 for controlling the opening and closing of the brake 3. The hydraulic pump assembly includes a main pump 15 and a pilot pump 14.

[0030] The accumulator 6 oil replenishment system module includes an accumulator 6, a third pressure sensor 7 for detecting the pressure of the accumulator 6, and an accumulator oil replenishment valve group 19, which is connected between the cooling pump 16 and the accumulator 6.

[0031] The execution module includes a brake cylinder 20, the accumulator 6 provides braking working pressure to the brake cylinder 20, and the accumulator 6 drives the brake cylinder 20 through the brake valve group 5.

[0032] The control module includes a handle 8 and a controller 9. The controller 9 receives signals from the handle 8, as well as signals from the first pressure sensor 11, the second pressure sensor 12, and the third pressure sensor 7, and controls the operation of the brake valve assembly 5 and the accumulator replenishment valve assembly 19.

[0033] The slewing system module and the accumulator 6 oil replenishment system module work together to release the brake and start the operation of the slewing motor 10 through the action signals of the handle 8 and the controller 9.

[0034] The excavator swing auxiliary brake hydraulic circuit in this application also includes the original heat dissipation module, which specifically includes a heat pump 16, a heat dissipation motor 17, and a heat dissipation fan 18.

[0035] The brake valve assembly 5 is a normally open type. When the brake valve assembly 5 receives a signal from the controller 9, the valve core moves, connecting the brake cylinder 20 with the hydraulic oil tank, allowing the oil in the brake cylinder 20 to flow back to the oil tank, and the brake 3 releases the brake under the action of the spring reset mechanism. When the brake valve assembly 5 does not receive a signal, the valve core resets, connecting the brake cylinder 20 with the accumulator 6, and the high-pressure oil in the accumulator 6 enters the brake cylinder 20, pushing the brake 3 to brake the brake disc 2.

[0036] The brake valve assembly 5 includes an electromagnetic cone valve with a leakage rate of no more than 5 drops / minute, forming a low-leakage brake valve assembly 5. The low-leakage configuration ensures that the pressure in the accumulator 6 can be maintained for a long time after shutdown, thereby achieving long-term braking.

[0037] The brake valve assembly 5 also includes a first variable throttle valve and a second variable throttle valve disposed in the brake oil circuit. The variable throttle valve is used to regulate the flow rate into and out of the brake cylinder 20, thereby controlling the smoothness of the braking and releasing process and reducing shock.

[0038] The cooling pump 16 is an electro-proportional pressure pump, and its output pressure is adjusted by the controller 9 to maintain a constant flow of oil supply to the cooling motor 17, ensuring the stable operation of the cooling system. At the same time, a small amount of hydraulic oil is taken from the cooling pump 16 to replenish the accumulator 6 without affecting the function of the original cooling system.

[0039] Combination Figure 7 This application also includes a braking mechanism that matches the aforementioned hydraulic circuit. The braking mechanism includes a slewing bearing 1, a brake disc 2, a brake 3, and a brake base 4. The brake disc 2 is fixed to the outer ring of the slewing bearing 1 by bolts. The outer ring of the slewing bearing 1 is connected to the upper rotating body of the excavator and rotates together with the upper rotating body.

[0040] The brake 3 is bolted to the brake base 4, which is welded to the excavator's undercarriage. The brake 3 is hydraulically driven and has an internal spring return mechanism. The brake 3 achieves rotary braking by applying pressure to the brake disc 2 to generate friction.

[0041] When hydraulic oil enters the brake cylinder 20, the brake 3 applies pressure to the brake disc 2 to generate friction, and achieves rotary braking through friction.

[0042] Combination Figure 5 -and Figure 6 This application also provides a control method for the above-mentioned excavator swing auxiliary braking hydraulic circuit, which is executed by the controller 9, specifically including accumulator 6 pressure maintenance control and swing braking logic control.

[0043] The working pressure of the brake 3 is provided by the accumulator 6 in the system. From the perspective of maintaining the pressure of the accumulator 6, when the third pressure sensor 7 detects that the pressure of the accumulator 6 is lower than the first preset pressure P0, the controller 9 controls the accumulator oil replenishment valve group 19 to open, and the cooling pump 16 replenishes oil to the accumulator 6. When the pressure in accumulator 6 reaches a second preset pressure P1 higher than P0, controller 9 controls accumulator oil replenishment valve group 19 to close, stopping oil replenishment. P0 and P1 can be set according to system requirements; for example, P0 can be set to 15MPa and P1 to 18MPa.

[0044] Specifically, see Figure 5When the vehicle starts, the third pressure sensor 7 senses whether the pressure of the accumulator 6 is lower than P0. If so, the controller 9 triggers the fuel replenishment logic command for the accumulator 6. Otherwise, the third pressure sensor 7 determines whether the pressure of the accumulator 6 is lower than P1 and enters the judgment of whether fuel replenishment is needed.

[0045] The accumulator replenishment valve assembly 19 includes a proportional pressure reducing valve 191, a servo valve core 192, and a proportional control valve 193.

[0046] The accumulator 6 oil replenishment logic command includes the controller 9 triggering the accumulator 6 oil replenishment logic command. The controller 9 outputs control current to the proportional control valve 193, and the proportional control valve 193 outputs control pressure to the servo valve core 192. The servo valve core 192 moves to the right, replenishing oil to the accumulator 6. At the same time, the input flow of the cooling motor 17 decreases, the inlet pressure decreases, the cooling pump 16 adaptively adjusts, the displacement increases, the flow of the cooling motor 17 increases, and the speed of the cooling fan 18 remains unchanged.

[0047] The third pressure sensor 7 determines whether the pressure in the accumulator 6 is lower than P1, and the determination of whether oil replenishment is needed includes: If the pressure of accumulator 6 is lower than P1, controller 9 checks the oil replenishment command from the previous cycle and continues to check if it is an oil replenishment command. If it is an oil replenishment command, then controller 9 triggers the oil replenishment logic command for accumulator 6. If it is not an oil replenishment command, then controller 9 enters the process of determining if the pressure of accumulator 6 is not lower than P1 by the third pressure sensor 7. That is, in the process of controller 9 triggering the release of the oil replenishment logic command for accumulator 6, controller 9 cuts off the output control current to proportional control valve 193. Proportional control valve 193 stops outputting control pressure to servo valve core 192. Servo valve core 192 moves to the left and stops replenishing oil to accumulator 6. The input flow of cooling motor 17 increases, the inlet pressure rises, cooling pump 16 adaptively adjusts and reduces displacement, cooling motor 17 input flow decreases, and cooling fan 18 speed remains unchanged.

[0048] The slewing brake logic control includes the brake release condition: when the handle 8 sends a slewing operation signal, the controller 9 controls the brake valve group 5 to receive the signal and release the slewing brake.

[0049] The slewing braking logic control includes a first braking trigger condition: when there is no slewing operation signal on the handle 8, and the pressure difference detected by the first pressure sensor 11 and the second pressure sensor 12 is less than a preset threshold ΔP, it is determined that the slewing motor 10 has stopped, and the brake valve group 5 implements slewing braking when no signal is received; the preset threshold ΔP is 0.8-1.2 MPa.

[0050] The slewing braking logic control includes a second braking trigger condition: when the duration of no slewing operation signal on handle 8 reaches a preset time T, brake valve group 5 implements slewing braking without receiving a signal; the preset time T is 3-5 seconds.

[0051] Specifically, after powering on, the safety lock switch is turned on, and it is determined whether there is a rotation signal on handle 8. If there is, controller 9 triggers the logic command to release the rotation brake. Brake valve group 5 receives the signal, the valve core of the brake valve enters the upper working position, the brake cylinder 20 is depressurized, the brake cylinder 20 retracts and the brake is released, and the rotary motor 10 starts running. At the same time that controller 9 triggers the logic command to release the rotation brake, the operating angle of rotary motor 10 is adjusted, the solenoid valve of main valve 13 is energized, outputting pilot pressure, the valve core of main valve 13 reverses, and the pressure oil of main pump 15 enters rotary motor 10, and rotary motor 10 starts running.

[0052] If there is no rotation signal from handle 8, the solenoid valve of main valve 13 loses power and stops outputting pilot pressure. The valve core of main valve 13 returns to the neutral position, the rotary motor 10 loses oil supply and decelerates, and the rotary motor 10 brakes.

[0053] Meanwhile, when there is no rotation signal from the handle 8, it is determined whether the pressure difference between the first pressure sensor 11 and the second pressure sensor 12 is less than 1 MPa. If it is less, the controller 9 triggers the rotation braking logic command. The brake valve group 5 does not receive a signal, the valve core of the brake valve enters the lower working position, the accumulator 6 is connected to the brake cylinder 20, the brake cylinder 20 extends and brakes, and the rotation motor 10 brakes.

[0054] If the pressure difference between the first pressure sensor 11 and the second pressure sensor 12 is not less than 1 MPa, determine whether the handle 8 has continuously lost the rotation signal for more than 5 seconds. If it is greater than 5 seconds, the controller 9 triggers the rotation braking logic command. If it is less than 5 seconds, return to the determination of whether the handle 8 has a rotation signal.

[0055] This application achieves reliable braking of the slewing mechanism at any angle by setting up an accumulator 6 and a low-leakage brake valve group 5. The accumulator 6 is replenished with oil using a heat dissipation pump 16 in the form of an electro-proportional pressure pump of the cooling system, without affecting the original heat dissipation function.

[0056] By detecting the pressure difference across the rotary motor 10 and the handle signal, the system intelligently determines the rotation status, achieving smooth braking and rapid release. Even after the main pump 15 stops, the system can still maintain braking for more than 30 minutes using the accumulator 6, making it suitable for long-term parking needs under special operating conditions.

[0057] This application enables slewing braking at any angle without needing to align to a specific position; the control system is simple and reliable, reducing the number of sensors and logic complexity; the braking release response is fast, with no risk of jamming; oil replenishment is achieved using the existing cooling pump 16, saving energy and not affecting heat dissipation; the accumulator 6 and low-leakage valve group ensure long-term braking capability; the variable throttle valve can reduce braking shock and extend component life.

[0058] This application uses the excavator's original independent cooling pump 16 as the power source for the hydraulic system, and borrows the electro-proportional constant pressure pump of the cooling system to supply oil to the braking mechanism without affecting the cooling system. By setting up an accumulator replenishment valve group 19, the oil source of the accumulator 6 is used to supply oil to the braking system. The opening and closing of the accumulator 6 replenishment can be controlled based on the pressure of the accumulator 6, reducing energy waste without affecting the cooling system.

[0059] The cooling pump 16 is an electro-proportional pressure pump, and the speed of the cooling fan 18 is determined by the pressure. After the pressure of the electro-proportional pressure pump is set, since the pump displacement has a certain margin, the flow rate entering the cooling motor 17 can be kept constant according to the adaptive adjustment function of the constant pressure pump. Therefore, taking a small amount of hydraulic oil from this pump will not affect the original cooling system.

[0060] Pressure sensors were added to both sides of the rotary motor 10, and the control strategy for rotary braking and starting was optimized. When the rotary motor 10 is working, it can achieve immediate release and braking after the motor stops rotating, which improves the service life of the brake 3 and the brake disc 2.

[0061] By employing an accumulator 6 and a low-leakage valve assembly, the pump can be continuously braked for more than 30 minutes after it stops working.

[0062] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0063] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A hydraulic circuit for auxiliary braking during the swing of an excavator, characterized in that, Includes: a slewing system module, an accumulator oil replenishment system module, an execution module, and a control module; The rotary system module includes a rotary motor, a first pressure sensor and a second pressure sensor for detecting the pressure on both sides of the rotary motor, a main valve for controlling the operation of the rotary motor, a hydraulic pump group for supplying oil to the main valve, and a brake valve group for controlling the opening and closing of the brake. The accumulator oil replenishment system module includes an accumulator, a third pressure sensor for detecting the pressure of the accumulator, and an accumulator oil replenishment valve group, which is connected between the cooling pump and the accumulator. The execution module includes a brake cylinder, the accumulator provides braking working pressure to the brake cylinder, and the accumulator drives the brake cylinder through the brake valve group; The control module includes a handle and a controller. The controller receives signals from the handle, as well as signals from the first pressure sensor, the second pressure sensor, and the third pressure sensor, and controls the operation of the brake valve assembly and the accumulator replenishment valve assembly.

2. The excavator swing auxiliary braking hydraulic circuit according to claim 1, characterized in that, The brake valve assembly includes a normally open brake valve assembly. When the brake valve assembly receives a signal, it connects the brake cylinder and the hydraulic tank to release the brake. When the brake valve assembly does not receive a signal, it connects the brake cylinder and the accumulator to apply the brake.

3. The excavator swing auxiliary braking hydraulic circuit according to claim 1, characterized in that, The brake valve assembly also includes a variable throttle valve disposed in the brake oil circuit, which is used to regulate the flow rate into and out of the brake cylinder.

4. The excavator swing auxiliary braking hydraulic circuit according to claim 1, characterized in that, It also includes a heat dissipation module, which includes a cooling motor and a cooling fan.

5. The excavator swing auxiliary braking hydraulic circuit according to claim 1, characterized in that, The cooling pump includes an electro-proportional pressure pump and is capable of maintaining a constant flow rate of oil to the cooling motor.

6. A control method for the hydraulic circuit of the excavator's swing auxiliary braking according to any one of claims 1-5, characterized in that, Executed by the controller, including accumulator pressure maintenance control and slewing braking logic control.

7. The control method according to claim 6, characterized in that, The accumulator pressure maintenance control includes: when the third pressure sensor detects that the accumulator pressure is lower than the first preset pressure P0, the controller controls the accumulator oil replenishment valve group to open, and the cooling pump replenishes oil to the accumulator. When the accumulator pressure reaches a second preset pressure P1 higher than P0, the controller controls the accumulator oil replenishment valve group to close and stop oil replenishment.

8. The control method according to claim 6, characterized in that, The slewing braking logic control includes a brake release condition: when the handle sends a slewing operation signal, the controller controls the brake valve group to receive the signal and release the slewing brake.

9. The control method according to claim 6, characterized in that, The slewing braking logic control includes a first braking trigger condition: when there is no slewing operation signal on the handle and the pressure difference detected by the first pressure sensor and the second pressure sensor is less than a preset threshold ΔP, it is determined that the slewing motor has stopped, and the brake valve group implements slewing braking when no signal is received. The preset threshold ΔP is 0.8-1.2 MPa.

10. The control method according to claim 5, characterized in that, The slewing braking logic control includes a second braking trigger condition: when the duration of no slewing operation signal on the handle reaches a preset time T, the brake valve group implements slewing braking in the absence of a signal. The preset time T is 3-5 seconds.

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