A hydraulic cooperative braking control system for large slope and heavy load auxiliary transport robot

Abstract

The application discloses a hydraulic cooperative braking control system for a large-gradient and heavy-load auxiliary transport robot, which comprises a brake cylinder, an oil tank, a pump unit, a first electromagnetic reversing valve and a first electro-hydraulic proportional overflow valve; a brake oil path module is arranged between the brake cylinder and the pump unit; the brake oil path module comprises a second electromagnetic reversing valve, a second electro-hydraulic proportional overflow valve and a pressure sensing unit; the second electromagnetic reversing valve is connected in series between the brake cylinder and the pump unit; the second electro-hydraulic proportional overflow valve is arranged in parallel between the second electromagnetic reversing valve and the brake cylinder and is used for controlling brake cylinder oil pressure; the pressure sensing unit is arranged at a brake shoe and is used for detecting braking force; a control module is connected with the pressure sensing unit at a signal input end and is connected with the second electro-hydraulic proportional overflow valve at a signal output end, and the control module is used for controlling the generated braking force to be maintained at a preset value; and the braking force is dynamically adjusted by means of a plurality of groups of brake oil path modules which do not interfere with each other, the braking force is accurately and constantly decelerated, and large-gradient and heavy-load downstroke working conditions are adapted.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of auxiliary transport robots, in particular to a hydraulic cooperative braking control system for large slope and heavy load auxiliary transport robots. BACKGROUND

[0002] As a common auxiliary transport robot, the monorail crane usually undertakes the work of transporting the vertically hanging objects below. At present, the monorail crane is usually used in the conventional operation condition of small slope, low load and low running speed. There is no monorail crane transport robot in the existing technology under the condition of large slope and heavy load, so that the existing monorail crane transport efficiency is low.

[0003] When the operation condition of large slope and heavy load is required, the technician usually controls the monorail crane to brake at constant deceleration. However, the existing monorail crane is usually used in the conventional operation condition of small slope, low load and low running speed. There is no monorail crane transport robot in the existing technology under the condition of large slope and heavy load, so that the existing monorail crane transport efficiency is low.

[0004] The existing monorail crane braking module with synchronous extension of brake shoes and consistent braking force is used in the braking process. However, the wear conditions of different brake shoes are inconsistent under the actual working condition. Therefore, when braking, different brake shoes are synchronized, some brake shoes are too tight, and some brake shoes are too loose, which further causes the braking time of each brake shoe to deviate. In turn, the braking force of each brake shoe deviates, resulting in deviation of the braking effect, which also aggravates the speed fluctuation.

[0005] Therefore, the existing technology cannot realize the function of accurate control of the monorail crane through constant deceleration braking of the monorail crane. The monorail crane transport robot cannot adapt to the operation under the condition of large slope and heavy load, which further limits the application of the monorail crane transport robot. SUMMARY

[0006] In view of the above technical problems, the present application provides a hydraulic cooperative braking control system for large slope and heavy load auxiliary transport robots. The braking oil circuit module cooperates with the control module to ensure that the braking force of the control shoe is always stable and maintained at the preset value, and then the monorail is braked at constant deceleration. The present application can effectively solve the limitation of the traditional monorail crane hydraulic braking system that cannot adapt to the large slope and heavy load downlink condition.

[0007] In order to achieve the above technical purpose, the present application adopts the following technical means:

[0008] The application discloses a hydraulic cooperative braking control system for a large-gradient and heavy-load auxiliary transport robot.

[0009] The oil tank is provided with a main oil outlet pipe at an outlet thereof, and the pump unit is connected in series in the main oil outlet pipe.

[0010] The application further discloses a hydraulic cooperative braking control system for a large-gradient and heavy-load auxiliary transport robot.

[0011] A plurality of braking oil path modules are connected in parallel on the main oil outlet pipe and are arranged one by one between the plurality of braking cylinders and the pump unit.

[0012] A control module is connected to the control pressure sensing unit at a signal input end and is electrically connected to the second electro-hydraulic proportional overflow valve at a signal output end, so as to control the braking force generated by the braking cylinder to be maintained at a preset value, thereby realizing constant deceleration braking of the braking cylinder.

[0013] The main oil outlet pipe is connected in series with a check valve at an outlet direction of the pump unit, so as to ensure that hydraulic oil cannot pass through the pump unit in a reverse direction.

[0014] The braking oil path module further comprises:

[0015] An accumulator is arranged in parallel between the second electromagnetic switching valve and the braking cylinder, so as to adjust an oil pressure difference between the braking cylinder and the second electro-hydraulic proportional overflow valve.

[0016] An oil inlet of the braking cylinder is communicated with the pump unit through an oil filter, and the oil filter is used for filtering and removing impurities from the passing hydraulic oil.

[0017] The pressure sensing unit comprises:

[0018] A pressure sensor is arranged at the brake shoe for converting the frictional braking force generated by the brake shoe into a data signal.

[0019] A control method of a hydraulic cooperative braking control system for a large-gradient and heavy-load auxiliary transport robot, comprising the following steps:

[0020] S1: The control module controls the control current of the first electro-hydraulic proportional relief valve to gradually decrease, the pump unit keeps the output flow unchanged, and the braking force generated by the brake shoe is measured by the pressure sensor;

[0021] S2: The control module controls the pump unit to stop working, the second electromagnetic reversing valve is powered off to disconnect the oil path channel of the brake cylinder and the oil tank, and the extension length of the brake cylinder controlled by each brake oil path module is ensured to be controlled by the second electro-hydraulic proportional relief valve, so that the holding force of the brake shoe can be controlled;

[0022] S3: The control module controls the second electro-hydraulic proportional relief valve to be in the maximum working current and gradually decrease until the pressure set value is reached; the braking force of the brake shoe controlled by the brake cylinder is maintained at a preset value, the constant braking force is maintained, the auxiliary transport robot maintains uniform speed reduction, and constant deceleration braking is performed;

[0023] S4: The control module compares the real-time braking force obtained by the pressure sensor with the braking force preset value calculated according to the measured traction force; when the real-time braking force is small, the corresponding variation of the second electro-hydraulic proportional relief valve current is controlled to be large, the internal oil pressure of the brake cylinder is reduced, and the braking force of the brake shoe is increased; otherwise, the control module controls the corresponding variation of the second electro-hydraulic proportional relief valve current to be small.

[0024] Beneficial effects:

[0025] Firstly, in the process of emergency braking, the control module can control the flow variation of the second electro-hydraulic proportional relief valve according to the signal of the pressure sensor, so that the brake shoe controlled by the brake cylinder generates a preset braking force; thereby, the monorail crane performs constant deceleration braking, and in the process of emergency braking of the monorail crane under large-gradient and heavy-load operation conditions, vibration and impact caused by rapid braking and braking force fluctuation are avoided.

[0026] Secondly, in the process of emergency braking, the hydraulic braking circuit designed in the application can independently control the braking force of the corresponding brake shoe due to the independence of the three braking modules, so that the brake shoe can accurately correspond to its holding force, and the speed is not deviated too much from the expected deceleration curve in the process of constant deceleration braking. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a braking hydraulic circuit schematic diagram of the application.

[0028] Figure 2 The braking control structure diagram of the application.

[0029] In the figure: 1, oil tank; 2, pressure indicator; 3, liquid level gauge; 4, thermometer; 5, safety valve; 6.0, accumulator D; 6.1, accumulator A; 6.2, accumulator B; 6.3, accumulator C; 7.1, pressure sensor A; 7.2, pressure sensor; 7.3, pressure sensor C; 8.0, first electro-hydraulic proportional overflow valve; 8.1, second electro-hydraulic proportional overflow valve A; 8.2, second electro-hydraulic proportional overflow valve B; 8.3, second electro-hydraulic proportional overflow valve C; 9, pump unit; 10.0, oil inlet filter A; 10.1, oil inlet filter B; 10.2, oil inlet filter C; 10.3, oil inlet filter D; 11, check valve; 12, overflow valve; 13.0, first electromagnetic reversing valve; 13.1, second electromagnetic reversing valve A; 13.2, second electromagnetic reversing valve B; 13.3, second electromagnetic reversing valve C; 14.1, brake cylinder A; 14.2, brake cylinder B; 14.3, brake cylinder C. DETAILED DESCRIPTION

[0030] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in combination with the drawings in the specification and specific embodiments.

[0031] A hydraulic cooperative braking control system for large slope and heavy load auxiliary transport robot, comprising a plurality of brake cylinders for braking the auxiliary transport robot, an oil tank for providing pressure oil for the brake cylinders, a pump unit for pumping pressure oil from the oil tank into the brake cylinders, a first electromagnetic reversing valve for controlling whether the brake cylinders unload oil, and a first electro-hydraulic proportional overflow valve for controlling the return of hydraulic oil to the oil tank. Specifically, the brake cylinders are at least three, including brake cylinder A, brake cylinder B and brake cylinder C.

[0032] The brake cylinders realize braking of the auxiliary transport robot by controlling the loose brake and closed brake state of the corresponding brake shoe. The plurality of brake cylinders are arranged side by side and communicate with the oil outlet of the pump unit. The outlet of the oil tank is provided with a main oil outlet pipe, the pump unit is connected with the brake cylinders through the main oil outlet pipe, and a plurality of brake oil path modules with the same structure are connected side by side on the main oil outlet pipe, which are arranged one by one between the plurality of brake cylinders and the pump unit.

[0033] The brake oil way module comprises a second electromagnetic reversing valve, a second electro-hydraulic proportional overflow valve and a pressure sensing unit.

[0034] Further, according to the corresponding brake oil way module, the second electromagnetic reversing valve is divided into a second electromagnetic reversing valve A, a second electromagnetic reversing valve B and a second electromagnetic reversing valve C; and the second electro-hydraulic proportional overflow valve is divided into a second electro-hydraulic proportional overflow valve A, a second electro-hydraulic proportional overflow valve B and a second electro-hydraulic proportional overflow valve C.

[0035] Further, the pressure sensing unit comprises a pressure sensor arranged at the brake shoe for converting the braking force generated by the friction of the brake shoe into a data signal.

[0036] The pressure sensor is arranged on each corresponding brake oil way module, and comprises a pressure sensor A, a pressure sensor B and a pressure sensor C.

[0037] A control module is electrically connected to the signal input end of the pressure sensing unit and electrically connected to the signal output end of the second electro-hydraulic proportional overflow valve, and is used for controlling the braking force generated by the brake cylinder to maintain a preset value to realize the constant deceleration braking of the brake cylinder.

[0038] Therefore, the monorail crane can generate the preset braking force by the brake shoe controlled by the brake cylinder under the control of the control module according to the signal of the pressure sensor, so that the monorail crane can realize the constant deceleration braking, and can not generate vibration impact due to the fluctuation of the braking force under the process of emergency braking under the working condition of large slope and heavy load.

[0039] Further, in order to adjust the oil pressure difference between the brake cylinder and the overflow valve, an accumulator is arranged in parallel between the second electromagnetic reversing valve and the brake cylinder. The accumulator is divided into an accumulator A, an accumulator B and an accumulator C.

[0040] Further, in order to prevent the hydraulic system from blocking after long time work, the oil inlet of the brake cylinder is communicated with the pump unit through the oil filter, and the oil filter is used for filtering and removing impurities of the passing hydraulic oil. Among them, the oil filter is divided into an oil inlet filter A arranged at the outlet of the pump unit, and an oil inlet filter B, an oil inlet filter C and an oil inlet filter D arranged at the corresponding brake cylinders respectively.

[0041] Further, the first electromagnetic reversing valve is provided with an overflow valve and a first electro-hydraulic proportional overflow valve in parallel; the overflow valve is provided with a fixed overflow pressure for preventing overpressure overload of the brake control system; the first electro-hydraulic proportional overflow valve is used to ensure the stability of the brake cylinder working pressure in the brake release state.

[0042] Further, in order to ensure the stability of the whole hydraulic circuit, an accumulator D is further arranged on the pipeline; and in order to facilitate the monitoring of the temperature, liquid level and pressure and other conventional data in the hydraulic circuit, improve the control accuracy and prevent safe operation, a thermometer, a liquid level meter and a pressure indicator are further arranged in the pipeline; in addition, in order to prevent the whole hydraulic circuit from appearing the dangerous situation of too high pressure, a safety valve is further arranged in the pipeline.

[0043] Specifically, the pump source device for driving the brake of the monorail crane includes an oil tank, a thermometer, a liquid level meter, a pressure indicator, an oil inlet filter, a check valve, a pump unit; these provide pressure source for the system to supply oil to the brake cylinder during the running of the monorail crane, so that the brake cylinder brake shoe is opened, and the monorail crane is braked by the braking force.

[0044] And the brake oil circuit module is divided into brake oil circuit module A, brake oil circuit module B and brake oil circuit module C; wherein, the three all include a second electromagnetic reversing valve adopting two-position two-way, an accumulator, a pressure sensor, an electro-hydraulic proportional overflow valve, an oil outlet filter; and the brake oil circuit module A, B and C are the same in structure.

[0045] Among them, the pump unit is connected with the oil inlets of the three groups of parallel second electromagnetic reversing valves A, B and C through the oil inlet filter A and the check valve; further, the second electromagnetic reversing valves A, B and C are directly connected with the brake cylinders A, B and C respectively; the oil outlets of the brake cylinders are connected with the oil inlets of the second electro-hydraulic proportional overflow valves A, B and C, and the oil outlets of the second electro-hydraulic proportional overflow valves A, B and C are connected with the oil tank; on the connection circuit of the brake cylinder and the second electromagnetic reversing valve, the pressure sensor A, the first second pressure sensor, the pressure sensor C and the accumulators A, B and C are arranged respectively.

[0046] At the same time, the overflow valve, the first electro-hydraulic proportional overflow valve and the first electromagnetic reversing valve are in parallel, the oil inlet of the two is connected with the oil outlet of the pump unit, and the corresponding oil outlets are directly connected with the oil tank; and the accumulator D and the pressure sensor D are arranged on the pipeline.

[0047] A control method of a hydraulic cooperative braking control system for a large-gradient and heavy-load auxiliary transport robot, the method adopts the hydraulic cooperative braking control system, and the control method comprises the following steps:

[0048] The single-track crane hydraulic cooperative braking control system has three working modes of working brake release, constant deceleration braking and parking braking.

[0049] Firstly, when working brake release is performed:

[0050] At this time, the system pressure has reached the set value; in the initial state, the overflow valve, the first electro-hydraulic proportional overflow valve, the second electro-hydraulic proportional overflow valve A, the second electro-hydraulic proportional overflow valve B and the second electro-hydraulic proportional overflow valve C are powered on; wherein the current signal of the first electro-hydraulic proportional overflow valve gradually increases from 0.

[0051] Further, the first electromagnetic reversing valve at this time loses power and belongs to the open state, the second electromagnetic reversing valve A, the second electromagnetic reversing valve B and the second electromagnetic reversing valve C lose power and belong to the communication state; thus, the return oil passages of the brake cylinders A, B and C are all closed.

[0052] Then, the pump unit starts to work to pump out the hydraulic oil, so that the hydraulic oil passes through the second electromagnetic reversing valve, the oil inlet filter and then enters the brake cylinder; at this time, the brake cylinder rapidly establishes the working pressure, and the piston rod extends to cause the brake shoe to release the brake;

[0053] Subsequently, when the working pressure of the brake shoe reaches the set value, the pump unit enters the low-speed working mode to ensure the stability of the brake cylinder pressure; then, the PLC controller performs PID control according to the feedback signal of the pressure sensor D to adjust the control current of the first electro-hydraulic proportional overflow valve, so as to ensure the stability of the brake cylinder working pressure in the working brake release state; at the same time, the overflow valve is set with a fixed overflow pressure to prevent system overpressure.

[0054] Subsequently, when constant deceleration braking is performed, the PLC controller executes the constant deceleration braking program:

[0055] Firstly, the control current of the first electro-hydraulic proportional overflow valve gradually decreases, the pump unit keeps the output flow unchanged, and then the brake cylinder oil pressure decreases to cause the brake shoe to clamp the moving wheel of the single-track crane, and then generate the braking force; at this time, the braking force is measured by the pressure sensors A, B and C.

[0056] Then, the pump unit stops working, the second electromagnetic reversing valve A, the second electromagnetic reversing valve B and the second electromagnetic reversing valve C are powered on and disconnected; at this time, the second electro-hydraulic proportional overflow valve A, the second electro-hydraulic proportional overflow valve B and the third electro-hydraulic proportional overflow valve C are at the set maximum working current and gradually decrease; with the gradual increase of the overflow amount of the three, the internal oil pressure of the brake cylinder begins to gradually decrease, and then the piston rod of the brake cylinder retracts, driving the brake shoe to further tighten the brake, increasing the braking force of the brake shoe; until the braking force reaches the pressure set value calculated by the PLC controller - the preset value, so that the originally dynamic braking force is kept in a constant interval as much as possible, and then the deceleration is kept constant and the speed is reduced at a uniform speed, so as to complete the constant deceleration braking; on the contrary, when the braking force is higher than the preset value, the internal oil pressure of the brake cylinder is increased and the braking force of the brake shoe is decreased.

[0057] Among them, the PLC controller measures the traction force of the single track through the regularly set sensor, calculates according to the preset value of 1.5 times of the traction force, and then obtains the changed preset value.

[0058] At the same time, since the brake oil circuit module adopts the mode of multiple groups of cooperative braking, several groups of brake oil circuit modules are independent of each other; therefore, the accumulators A, B and C added to the brake oil circuit module respectively provide hydraulic energy for the constant deceleration braking circuit, thereby improving the control precision, realizing dynamic adjustment of the braking force and completing the constant deceleration braking.

[0059] When the final stop braking state is reached:

[0060] Firstly, the acceleration sensor detects the running speed of the monorail, and when the PLC controller detects that the running speed of the monorail approaches zero, the first electro-hydraulic proportional overflow valve is powered off and disconnected, the second electro-hydraulic proportional overflow valve A, the second electro-hydraulic proportional overflow valve B and the second electro-hydraulic proportional overflow valve C are powered on and connected, and the second electromagnetic reversing valve A, the second electromagnetic reversing valve B and the second electromagnetic reversing valve C are powered off and disconnected.

[0061] At this time, the first electromagnetic reversing valve is powered on and connected, at this time, the three groups of brake cylinders are directly connected to the oil tank, the brake shoe is closed and locked, and the stop state is entered.

Claims

1. A hydraulic coordinated braking control system for a large-gradient and heavy-load auxiliary transport robot, comprising a plurality of brake cylinders for braking the auxiliary transport robot, an oil tank for providing pressure oil for the brake cylinders, a pump unit for pumping pressure oil from the oil tank into the brake cylinders, a first electromagnetic switching valve for controlling whether the brake cylinders are unloaded, and a first electro-hydraulic proportional relief valve for controlling the return of hydraulic oil to the oil tank; wherein An outlet of the oil tank is provided with a main oil outlet pipe, and the pump unit is connected in series in the main oil outlet pipe; The brake cylinders realize braking of the auxiliary transport robot by controlling the loosening and closing states of the brake shoes. Characterized in that it comprises: A plurality of brake oil path modules are connected in parallel on the main oil outlet pipe, and are one-to-one arranged between the plurality of brake cylinders and the pump unit; Each brake oil path module comprises at least a second electromagnetic switching valve, a second electro-hydraulic proportional relief valve and a pressure sensing unit; The second electromagnetic switching valve is connected in series between the brake cylinder and the pump unit, and is used to control the brake cylinder to be disconnected from the pump unit during constant deceleration braking; The second electro-hydraulic proportional relief valve is connected in parallel between the second electromagnetic switching valve and the brake cylinder, and is used to receive the oil outlet of the brake cylinder to control the braking force generated by the brake cylinder; The pressure sensing unit is arranged at the corresponding brake shoe, and is used to detect the braking force of the corresponding brake shoe; A control module, whose signal input end is electrically connected with the pressure sensing unit, and whose signal output end is electrically connected with the second electro-hydraulic proportional relief valve, is used to control the braking force generated by the brake cylinder to maintain a preset value to realize constant deceleration braking of the brake cylinder. 2.The hydraulic coordinated braking control system for a large-gradient and heavy-load auxiliary transport robot according to claim 1, characterized in that: The main oil outlet pipe is connected in series with a check valve in the outlet direction of the pump unit, and the check valve is used to ensure that the hydraulic oil cannot pass through the pump unit in reverse.

3. The hydraulic coordinated braking control system for steep grade, heavy load assist transport robot according to claim 1, characterized in that, The brake oil path module further comprises: An accumulator, which is connected in parallel between the second electromagnetic switching valve and the brake cylinder, is used to adjust the oil pressure difference between the brake cylinder and the second electro-hydraulic proportional relief valve. 4.The hydraulic coordinated braking control system for a large-gradient and heavy-load auxiliary transport robot according to claim 1, characterized in that: The oil inlet of the brake cylinder is communicated with the pump unit through an oil filter, and the oil filter is used to filter and remove impurities from the passing hydraulic oil.

5. The hydraulic coordinated braking control system for steep grade, heavy load assist transport robot according to claim 1, wherein, The pressure sensing unit comprises: A pressure sensor, which is arranged at the brake shoe, is used to convert the braking force generated by the brake shoe into a data signal.

6. A control method of a hydraulic coordinated braking control system for a large slope, heavy load auxiliary transport robot, the method employing the hydraulic coordinated braking control system according to any one of claims 1 to 5, characterized by, The control method comprises the following steps: S1:The control module controls the control current of the first electro-hydraulic proportional relief valve to gradually decrease, the pump unit keeps the output flow unchanged, and the braking force generated by the brake shoe is measured by the pressure sensor. S2: The control module controls the pump unit to stop working, the second electromagnetic reversing valve is powered off to disconnect the oil passage between the brake cylinder and the oil tank, ensuring that the brake cylinders controlled by each brake oil passage module are controlled in extension length by the second electro-hydraulic proportional overflow valve, thereby controlling the brake force of the brake shoe; S3: The control module controls the second electro-hydraulic proportional overflow valve to be in maximum working current and gradually decreases until the pressure set value is reached; the brake cylinder controls the brake force of the brake shoe to maintain at a preset value, keeps the brake force constant, and helps the transport robot to maintain uniform speed reduction, so as to carry out constant deceleration braking; S4: The control module compares the real-time brake force obtained by the pressure sensor with the brake force preset value calculated according to the measured traction force in advance; when the real-time brake force is small, the control module controls the second electro-hydraulic proportional overflow valve current to correspondingly increase, reduces the internal oil pressure of the brake cylinder, and increases the brake force of the brake shoe; otherwise, the control module controls the second electro-hydraulic proportional overflow valve current to correspondingly decrease.

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