Power flow control method and system for hydraulic system of cantilever roadheader

Abstract

The present invention discloses a power flow control method and system for a cantilevered tunnel boring machine hydraulic system. This method does not limit the power of a single pump during tunneling operations, and can provide the full power of the motor to a single system, greatly improving the construction efficiency of a single system. The method also detects the working current of the motor in real time and determines whether it is overloaded. In the event of overload, the overload protection time is calculated based on the overload current value and the rated current value. When the duration of the overload reaches the overload protection time, the motor is controlled to automatically shut down. At the same time, since the combined action of the traveling arm system and the loading and transport system and the simultaneous high-power operation are characterized by low frequency and short duration, by adopting the above-mentioned motor protection program, it is possible to maximize the utilization of the motor power and realize the automatic protection function of the motor. In particular, in the face of complex geological environments, the speed of cutting and slag discharge can be guaranteed by short-term overloading of the pump station motor, greatly improving the overall construction efficiency.

Description

Technical Field

[0001] The present invention relates to the field of control technology of a cantilever roadheader, and in particular, to a power flow control method and system for a hydraulic system of a cantilever roadheader, and further to a cantilever roadheader using the above control system. Background Art

[0002] Currently, the hydraulic systems of boom roadheaders (TBMs) mostly utilize a dual variable displacement piston pump coupled with a load-sensitive proportional multi-way valve. The variable displacement piston pumps output the required flow according to the flow demand of each actuator, and the flow to each actuator is controlled by adjusting the valve core opening of the proportional multi-way valve. The hydraulic system's power is controlled by adjusting the constant power valve of a single variable displacement piston pump to limit the power of each pump, ensuring that the total power of the hydraulic system is not overloaded during operation. However, during operation, the hydraulic system of a boom roadheader rarely reaches maximum power simultaneously, and the motor characteristics allow for brief overloads. Therefore, the hydraulic system of a boom roadheader does not maximize motor power during normal operation, resulting in a certain degree of redundant motor power. Furthermore, during hard rock excavation and mucking, the loading and transport system is prone to jamming due to sudden overstocking. This jam requires manual mucking removal, which is difficult and wastes a lot of work time. Summary of the Invention

[0003] The present invention provides a power flow control method and system for a cantilever roadheader hydraulic system, and a cantilever roadheader, so as to solve the technical problem that the hydraulic system of the existing cantilever roadheader does not maximize the utilization of motor power and has redundant design of motor power.

[0004] According to one aspect of the present invention, a power flow control method for a hydraulic system of a cantilever roadheader is provided, comprising the following contents:

[0005] During the tunneling operation, the power of a single variable displacement plunger pump is not limited, and the operating current of the pump station motor is detected in real time to determine whether the pump station motor is overloaded;

[0006] When the pump station motor is overloaded, the overload protection time of the pump station motor is calculated based on the overload current value and the rated current value;

[0007] Determine whether the duration of the pump station motor overload reaches the overload protection time. If so, control the pump station motor to automatically shut down.

[0008] Furthermore, the overload protection time of the pump station motor is calculated based on the following formula:

[0009]

[0010] Where, t represents the overload protection time, Ia Indicates the overload current value, I b Indicates the rated current value.

[0011] Furthermore, when the duration of the pump station motor overload does not reach the overload protection time, the following contents are also included:

[0012] The current value of the working link corresponding to the walking system and / or boom system in the first electric proportional multi-way valve is controlled to decrease, so as to reduce the input flow of the walking system and / or boom system, and control the input flow of the loading and transportation system to remain unchanged.

[0013] Furthermore, when the traveling system and the loading and transporting system work simultaneously, the current value of the traveling link in the first electric proportional multi-way valve is controlled based on the following formula:

[0014]

[0015] Among them, I 行走 Indicates the current value of the first electric proportional multi-way valve, c indicates the overload coefficient, P 额 Indicates the rated output power of the pump station motor, p2 indicates the outlet pressure of the second variable piston pump, p1 indicates the outlet pressure of the first variable piston pump, a 行走 and b 行走 Indicates the two constants used to calculate the output flow of the traveling link in the first electric proportional multi-way valve, n represents the number of working links working simultaneously in the second electric proportional multi-way valve, I i Indicates the current value of the i-th working link in the second electric proportional multi-way valve, a i and b i They represent the two constants used to calculate the output flow of the i-th working unit.

[0016] Furthermore, when the cutting arm lifting cylinder of the boom system and the loading and transporting system work simultaneously, the current value of the cutting lifting link in the first electric proportional multi-way valve is controlled based on the following formula:

[0017]

[0018] Among them, I 举升 Indicates the current value of the cut-off lifting link in the first electric proportional multi-way valve, c indicates the overload coefficient, P 额 Indicates the rated output power of the pump station motor, p2 indicates the outlet pressure of the second variable piston pump, p1 indicates the outlet pressure of the first variable piston pump, a 举升 and b 举升 Indicates the two constants used to calculate the output flow of the cut-off lifting link in the first electric proportional multi-way valve, n represents the number of working links working simultaneously in the second electric proportional multi-way valve, I iIndicates the current value of the i-th working link in the second electric proportional multi-way valve, a i and b i They represent the two constants used to calculate the output flow of the i-th working unit.

[0019] Furthermore, when the cutting arm rotary cylinder of the boom system and the loading and transporting system work simultaneously, the current value of the cutting rotary link in the first electric proportional multi-way valve is controlled based on the following formula:

[0020]

[0021] Among them, I 回转 Indicates the current value of the cut-off rotary link in the first electric proportional multi-way valve, c indicates the overload coefficient, P 额 Indicates the rated output power of the pump station motor, p2 indicates the outlet pressure of the second variable piston pump, p1 indicates the outlet pressure of the first variable piston pump, a 回转 and b 回转 Indicates two constants used to calculate the output flow of the cut-off rotary link in the first electric proportional multi-way valve, n represents the number of working links working simultaneously in the second electric proportional multi-way valve, I i Indicates the current value of the i-th working link in the second electric proportional multi-way valve, a i and b i They represent the two constants used to calculate the output flow of the i-th working unit.

[0022] Furthermore, the following contents are also included:

[0023] Real-time detection of the pressure of the first transport motor in the loading and transport system. When it is detected that the pressure value of the first transport motor exceeds the set value, the current value of the loading motor link in the second electric proportional multi-way valve is controlled to decrease to reduce the input flow of the loading motor.

[0024] Furthermore, the current value of the loading motor is controlled based on the following formula:

[0025]

[0026] Among them, I 装载 Indicates the current value of the motor in the second electric proportional multi-way valve, P 运输 It represents the sum of the power output from the second variable piston pump to the loading motor and the first transport motor, which is a constant value. 一运 Indicates the pressure value of a motor, a 装载 and b 装载 Indicates the two constants used to calculate the output flow of the motor link in the second electric proportional multi-way valve, a 一运 and b 一运 Indicates the two constants used to calculate the output flow of the first motor in the second electric proportional multi-way valve, I一运 Indicates the current value of a motor in the second electric proportional multi-way valve.

[0027] In addition, the present invention also provides a power flow control system for a cantilever roadheader hydraulic system, which adopts the power flow control method described above and includes:

[0028] The current acquisition module is used to detect the operating current of the pump station motor in real time during the excavation operation and determine whether the pump station motor is overloaded;

[0029] An overload protection time calculation module is used to calculate the overload protection time of the pump station motor based on the overload current value and the rated current value when the pump station motor is overloaded;

[0030] The shutdown control module is used to determine whether the duration of the pump station motor overload reaches the overload protection time. If so, the pump station motor is controlled to automatically shut down.

[0031] In addition, the present invention also provides a cantilever type roadheader, which adopts the power flow control system as described above.

[0032] The present invention has the following effects:

[0033] The power flow control method for the hydraulic system of a cantilevered tunnel boring machine of the present invention does not limit the power of a single variable displacement plunger pump during tunneling operations. When any one of the travel system, boom system, and loading and transport system realizes the function of a single system, the full power of the pump station motor can be provided to the single system, enabling the single system to operate at maximum efficiency, greatly improving the construction efficiency of the single system. Furthermore, during tunneling operations, the operating current of the pump station motor is detected in real time to determine whether the pump station motor is overloaded. When the pump station motor is overloaded, the overload protection time of the pump station motor is calculated based on the overload current value and the rated current value. The overload protection time of the pump station motor can be accurately calculated under different overload conditions, and the pump station motor is automatically shut down only when the duration of the overload of the pump station motor reaches the overload protection time. At the same time, the traveling arm system and loading and transport system in the hydraulic system of the cantilever tunnel boring machine perform compound actions and operate at high power at the same time, which is characterized by low frequency and short time. By adopting the above-mentioned motor protection program, it is possible to maximize the utilization of motor power and realize the automatic protection function of the motor. Especially in the face of complex geological environments, the speed of cutting and slag discharge can be guaranteed by short-term overload of the pump station motor, which greatly improves the overall construction efficiency.

[0034] In addition, the power flow control system of the cantilever roadheader hydraulic system and the cantilever roadheader of the present invention also have the above advantages.

[0035] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0037] Figure 1 It is a schematic diagram of the principle of the hydraulic system of the cantilever type roadheader of the present invention.

[0038] Figure 2 It is a flow chart of a power flow control method of a cantilever roadheader hydraulic system according to a preferred embodiment of the present invention.

[0039] Figure 3 It is a schematic diagram of a curve showing the relationship between the overload amount and the overload protection time of a pump station motor in a preferred embodiment of the present invention.

[0040] Figure 4 Schematic diagram of a characteristic curve between current and output flow of an electric proportional multi-way valve in a preferred embodiment of the present invention.

[0041] Figure 5 It is a flow chart of a power flow control method of a cantilever roadheader hydraulic system according to another embodiment of the present invention.

[0042] Figure 6 It is a schematic diagram of the module structure of a power flow control system of a cantilever roadheader hydraulic system according to another embodiment of the present invention.

[0043] Description of Reference Numerals

[0044] 1. Pump station motor; 2. First variable piston pump; 3. Second variable piston pump; 4. First electric proportional multi-way valve; 5. Second electric proportional multi-way valve; 6. Travel motor; 7. Cutting arm lifting cylinder; 8. Cutting arm rotating cylinder; 9. Loading motor; 10. First transport motor; 11. Second transport motor; 12. Pressure sensor. DETAILED DESCRIPTION

[0045] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0046] It is understandable that Figure 1As shown, the cantilever tunnel boring machine hydraulic system adopted in the present invention specifically includes a pump station motor 1, a first variable piston pump 2, a second variable piston pump 3, a first electric proportional multi-way valve 4, a second electric proportional multi-way valve 5, a travel motor 6, a cutting arm lifting cylinder 7, a cutting arm rotating cylinder 8, a loading motor 9, a first transport motor 10, and a second transport motor 11, wherein the travel motor 6 is the actuator of the travel system, the cutting arm lifting cylinder 7 and the cutting arm rotating cylinder 8 are the actuators of the arm system, the travel system and the arm system constitute the travel arm system, and the loading motor 9, the first transport motor 10, and the second transport motor 11 are the actuators of the loading and transportation system. The pump station motor 1 drives the first variable piston pump 2 and the second variable piston pump 3 in series. The first variable piston pump 2 is connected to the first electric proportional multi-way valve 4. The first LS port of the first electric proportional multi-way valve 4 is connected to the LS port of the first variable piston pump 2. The first electric proportional multi-way valve 4 is connected to the travel motor 6, the cutting arm lifting cylinder 7, and the cutting arm rotation cylinder 8, respectively. That is, the working links of the first electric proportional multi-way valve 4 include the travel link, the cutting lifting link, and the cutting rotation link. The second variable piston pump 3 is connected to the second electric proportional multi-way valve 5. The first LS port of the second electric proportional multi-way valve 5 is connected to the LS port of the second variable piston pump 3. The second electric proportional multi-way valve 5 is connected to the loading motor 9, the first transport motor 10, and the second transport motor 11, respectively. That is, the working links of the second electric proportional multi-way valve 5 include the loading motor link, the first transport motor link, and the second transport motor link. The travel motor 6, cutting arm lift cylinder 7, cutting arm rotation cylinder 8, loading motor 9, and first-operation motor 10 are all equipped with pressure sensors 12 at their inlets and outlets. However, the second-operation motor 11 only has a pressure sensor 12 at its inlet because the second-operation motor 11 only performs unidirectional motion, while the travel motor 6, cutting arm lift cylinder 7, cutting arm rotation cylinder 8, loading motor 9, and first-operation motor 10 can perform bidirectional motion. The input flow of the travel motor 6, cutting arm lift cylinder 7, and cutting arm rotation cylinder 8 can be controlled by changing the output current of the corresponding working link valve proportional solenoid in the first electric proportional multi-way valve 4 via an electric control handle, or the maximum output current can be limited by a program. Once activated, the loading motor 9, first-operation motor 10, and second-operation motor 11 operate at a fixed flow rate. In anti-jamming conditions, the output current can be controlled by a program to control the motor speed.

[0047] It is understandable that Figure 2 As shown, a preferred embodiment of the present invention provides a power flow control method for a cantilever roadheader hydraulic system, comprising the following contents:

[0048] Step S1: During the excavation operation, the power of a single variable displacement plunger pump is not limited, and the working current of the pump station motor is detected in real time to determine whether the pump station motor is overloaded;

[0049] Step S2: When the pump station motor is overloaded, the overload protection time of the pump station motor is calculated based on the overload current value and the rated current value;

[0050] Step S3: Determine whether the duration of the pump station motor overload reaches the overload protection time. If so, control the pump station motor to automatically shut down.

[0051] It can be understood that the power flow control method for the cantilever tunnel boring machine hydraulic system of this embodiment does not limit the power of a single variable displacement piston pump during tunneling operations. When any of the travel system, boom system, and loading and transport system functions as a single system, the full power of the pump station motor can be provided to the single system, allowing the single system to operate at maximum efficiency, greatly improving the construction efficiency of the single system. Furthermore, during tunneling operations, the operating current of the pump station motor is detected in real time to determine whether the pump station motor is overloaded. When the pump station motor is overloaded, the overload protection time of the pump station motor is calculated based on the overload current value and the rated current value. The overload protection time of the pump station motor can be accurately calculated under different overload conditions. The pump station motor is automatically shut down only when the duration of the overload of the pump station motor reaches the overload protection time. At the same time, the traveling arm system and loading and transport system in the hydraulic system of the cantilever tunnel boring machine perform compound actions and operate at high power at the same time, which is characterized by low frequency and short time. By adopting the above-mentioned motor protection program, it is possible to maximize the utilization of motor power and realize the automatic protection function of the motor. Especially in the face of complex geological environments, the speed of cutting and slag discharge can be guaranteed by short-term overload of the pump station motor, which greatly improves the overall construction efficiency.

[0052] It is understood that in step S1, the power of a single variable displacement piston pump is not limited during the excavation operation. Each variable displacement piston pump can provide a higher output power to the system it drives. When any one of the travel system, boom system, and loading and transport system realizes the function of a single system, the full power of the pump station motor can be provided to the single system, allowing the single system to operate at the highest efficiency, greatly improving the construction efficiency of the single system. In addition, by installing a current sensor on the pump station motor to detect the operating current of the pump station motor in real time, when the real-time operating current of the pump station motor is greater than its rated operating current, the pump station motor is determined to be overloaded.

[0053] It can be understood that in step S2, when it is determined that the pump station motor is overloaded, the motor overload protection program is started, and the overload protection time of the pump station motor is calculated based on the overload current value and the rated current value. The specific calculation formula is:

[0054]

[0055] Among them, t represents the overload protection time of the pump station motor, I a Indicates the overload current value of the pump station motor, I b Indicates the rated current value of the pump station motor.

[0056] It is understood that when a motor's operating current continuously exceeds its rated current, the motor's operating time will be inversely proportional to the operating current. However, the specific functional relationship between the motor's operating time and operating current has not yet been clearly established, making it impossible to accurately calculate the motor's overload protection time. The inventors of this application have discovered that the relationship between different motor overload levels and the corresponding downtime is shown in Table 1.

[0057] Table 1. Relationship between motor overload status and corresponding downtime

[0058] <![CDATA[I a / I b ]]> Overload state action 1.05 Slight overload If it continues to be greater than 1.05, the machine will be shut down within 120 minutes. 1.2 Moderate overload If it continues to be greater than 1.2, the machine will be shut down within 20 minutes. 1.5 Severe overload If it continues to be greater than 1.5, the machine will be shut down within 3 minutes. 6 Stalled If the value is continuously greater than 6, the system will stop within 15 seconds.

[0059] The inventors of this application calculated the overload value I by fitting the overload value I according to Table 1 through Matlab. a / I b The relationship curve with overload protection time t is as follows: Figure 3 As shown, the functional relationship is obtained according to the relationship curve:

[0060] It can be understood that in step S3, when the duration of the pump station motor overload reaches the overload protection time, the pump station motor is controlled to automatically shut down, thereby ensuring the safety of the motor.

[0061] It can be understood that the present invention obtains the relationship between the motor overload and the corresponding downtime through long-term research, and fits the functional relationship between the overload and the overload protection time, so as to accurately calculate the overload protection time corresponding to the motor under different overloads, thereby ensuring the safe use of the motor while maximizing the utilization of the motor power.

[0062] Optionally, in step S3, when the duration of the pump station motor overload does not reach the overload protection time, the method further includes the following:

[0063] The current value of the working link corresponding to the walking system and / or boom system in the first electric proportional multi-way valve is controlled to decrease, so as to reduce the input flow of the walking system and / or boom system, and control the input flow of the loading and transportation system to remain unchanged.

[0064] It is understood that when the duration of the pump station motor overload does not reach the overload protection time, the motor power can be reasonably distributed to switch the pump station motor overload state to a slight overload or even no overload, thereby avoiding frequent overload shutdowns. Frequent motor overload shutdowns are particularly prone to occur when the traveling boom system and the loading and transport system are in combined motion and running at high power simultaneously.

[0065] In addition, there is an approximate linear proportional relationship between the single output flow and the input current of the electric proportional multi-way valve. Therefore, the present invention is based on the current and output flow characteristic curve of the electric proportional multi-way valve, specifically as follows Figure 4 As shown, within the range of the electromagnet working current, the output flow of each working link and its current are approximately fitted into the following relationship: Q = aI + b, where Q represents the output flow of the single valve, I represents the output current of the single valve electromagnet, a and b are constants, and the specific values ​​can be calculated based on the corresponding flow of different valve cores. The values ​​of constants a and b corresponding to different working links in the electric proportional multi-way valve are different. The output power of the pump P = Q 总 *p,Q 总 Indicates the total output flow of the pump, p indicates the outlet working pressure of the pump, n represents the number of actuators controlled by the pump during compound action.

[0066] Therefore, the real-time power of the first variable displacement piston pump can be expressed as: P1 represents the output power of the first variable piston pump, p1 represents the pump outlet pressure of the first variable piston pump, specifically the maximum pressure value of the pressure sensors installed at the travel motor, the cutting arm lifting cylinder and the cutting arm rotating cylinder, I j Indicates the current value of the jth working link in the first electric proportional multi-way valve, a j and b j They represent two constants used in calculating the output flow of the j-th working link, and m represents the number of working links working simultaneously in the first electric proportional multi-way valve.

[0067] The real-time power of the second variable piston pump can be expressed as: P2 represents the output power of the second variable piston pump, p2 represents the pump outlet pressure of the second variable piston pump, specifically the maximum pressure value of the pressure sensors installed at the loading motor, the first transport motor and the second transport motor, I i Indicates the current value of the i-th working link in the second electric proportional multi-way valve, a i and b i They represent two constants used in calculating the output flow of the i-th working link, and n represents the number of working links working simultaneously in the second electric proportional multi-way valve.

[0068] The real-time total power of the pump station motor is: P 总 =P1+P2.

[0069] Therefore, when the load pressure of a certain actuator increases, the power of the entire machine will increase. Once the motor is overloaded, it is necessary to give priority to ensuring the flow and power of each motor in the loading and transporting system. Otherwise, once the loading and transporting system slows down, the pile of materials will easily get stuck. Therefore, when the pump station motor is overloaded and the duration of the overload does not reach the overload protection time, the present invention controls the current value of the working link corresponding to the walking system and / or the boom system in the first electric proportional multi-way valve to be reduced, so as to reduce the input flow of the walking system and / or the boom system, and controls the input flow of the loading and transporting system to remain unchanged, thereby reducing the total flow of the hydraulic system and further reducing the output power of the pump station motor. After the output power of the pump station motor is restored to within the rated power, the various actions driven by the first electric proportional multi-way valve are restored to normal.

[0070] It can be understood that as another option, when calculating the real-time total power of the pump station motor, it is also possible to detect the motor speed data and cylinder displacement data by installing a speed sensor on each motor and a displacement sensor on each cylinder, so that the motor speed data and cylinder displacement data can be converted into the real-time flow of each action, and then calculated with the pressure data detected by the pressure sensors installed on each motor and each cylinder to obtain the real-time power of the pump station motor.

[0071] In addition, as a preferred embodiment, the present invention takes into account that the operating conditions where the walking system and the boom system operate simultaneously are very rare. In order to improve the response speed of the power distribution control, the actions of the walking system and the boom system are decomposed into individual actions and executed in sequence, that is, the program sets the walking system and the boom system to only operate separately. Specifically, when the walking system and the loading and transporting system work simultaneously, the power consumed by the walking system is P 行走 =cP 额 -P2, while Therefore, the current value of the travel link in the first electric proportional multi-way valve is controlled based on the following formula:

[0072]

[0073] Among them, I 行走 Indicates the current value of the first electric proportional multi-way valve in the travel link, c represents the overload coefficient, which can be set according to different working conditions, P 额 Indicates the rated output power of the pump station motor, p2 indicates the outlet pressure of the second variable piston pump, p1 indicates the outlet pressure of the first variable piston pump, a 行走 and b 行走 Indicates the two constants used to calculate the output flow of the traveling link in the first electric proportional multi-way valve, n represents the number of working links working simultaneously in the second electric proportional multi-way valve, I i Indicates the current value of the i-th working link in the second electric proportional multi-way valve, a i and bi They represent the two constants used to calculate the output flow of the i-th working unit.

[0074] When the cutting arm lifting cylinder of the boom system and the loading and transporting system work at the same time, the power consumed by the cutting arm lifting cylinder is: P 升降 =cP 额 -P2, therefore, the current value of the cut-off lifting link in the first electric proportional multi-way valve is controlled based on the following formula:

[0075]

[0076] Among them, I 举升 Indicates the current value of the cut-off lifting link in the first electric proportional multi-way valve, c indicates the overload coefficient, P 额 Indicates the rated output power of the pump station motor, p2 indicates the outlet pressure of the second variable piston pump, p1 indicates the outlet pressure of the first variable piston pump, a 举升 and b 举升 Indicates the two constants used to calculate the output flow of the cut-off lifting link in the first electric proportional multi-way valve, n represents the number of working links working simultaneously in the second electric proportional multi-way valve, I i Indicates the current value of the i-th working link in the second electric proportional multi-way valve, a i and b i They represent the two constants used to calculate the output flow of the i-th working unit.

[0077] When the cutting arm rotary cylinder of the boom system and the loading and transporting system work at the same time, the power consumed by the cutting arm rotary cylinder is: P 回转 =cP 额 -P2, controls the current value of the cut-off rotary link in the first electric proportional multi-way valve based on the following formula:

[0078]

[0079] Among them, I 回转 Indicates the current value of the cut-off rotary link in the first electric proportional multi-way valve, c indicates the overload coefficient, P 额 Indicates the rated output power of the pump station motor, p2 indicates the outlet pressure of the second variable piston pump, p1 indicates the outlet pressure of the first variable piston pump, a 回转 and b 回转 Indicates two constants used to calculate the output flow of the cut-off rotary link in the first electric proportional multi-way valve, n represents the number of working links working simultaneously in the second electric proportional multi-way valve, I i Indicates the current value of the i-th working link in the second electric proportional multi-way valve, a i and b i They represent the two constants used to calculate the output flow of the i-th working unit.

[0080] It can be understood that in order to prevent the motor from frequently overloading and shutting down during compound actions, the present invention distributes and adjusts the flow of each action in the motor overload state. Through the system-set flow algorithm control program that automatically adjusts the motor's walking, arm and other actions in the overload state, the automatic distribution of the whole machine flow and power can be achieved, thereby improving work efficiency.

[0081] Alternatively, as Figure 5 As shown, the power flow control method further includes the following contents:

[0082] Step S4: Real-time detection of the pressure of a transport motor in the loading and transport system. When it is detected that the pressure value of the transport motor exceeds the set value, the current value of the loading motor link in the second electric proportional multi-way valve is controlled to decrease to reduce the input flow of the loading motor.

[0083] Understandably, during hard rock excavation and slag removal, the hydraulic system of a boom-type roadheader can easily become stuck due to excessive material accumulation in the loading and transport system. Therefore, the present invention detects the operating pressure of the primary motor in real time. If the pressure of the primary motor is detected to have increased and exceeded a set value, the current value of the loading motor connection in the second electro-proportional multi-way valve is automatically adjusted to decrease, thereby reducing the speed of the loading motor. This reduces the incoming material to the loading and transport system, avoids the problem of excessive material accumulation at the primary motor causing it to become stuck, implements an anti-jamming function, eliminates the time required for manual slag removal after a material pile becomes stuck, improves work efficiency, and enhances the applicability of the boom-type roadheader in hard rock excavation conditions.

[0084] The current value of the loading motor is controlled based on the following formula:

[0085]

[0086] Among them, I 装载 Indicates the current value of the motor in the second electric proportional multi-way valve, P 运输 It represents the sum of the power output from the second variable piston pump to the loading motor and the first transport motor, which is a constant value. 一运 Indicates the pressure value of a motor, a 装载 and b 装载 Indicates the two constants used to calculate the output flow of the motor link in the second electric proportional multi-way valve, a 一运 and b 一运 Indicates the two constants used to calculate the output flow of the first motor in the second electric proportional multi-way valve, I 一运 Indicates the current value of a motor in the second electric proportional multi-way valve.

[0087] It can be understood that when the motor is overloaded, it is necessary to give priority to ensuring the flow rate and power of each motor in the loading and transportation system, while the flow rate and power of the secondary motor remain unchanged during the working process, so P is defined as 运输 It is the sum of the power consumed by the loading motor and the first transport motor, which is set as a fixed value. The specific value can be set according to different construction conditions. 运输 =P 装载 +P 一运 , P 装载 Indicates the power consumed by the loading motor, P 一运 Indicates the power consumed by a motor. Therefore, P 运输 =p2*[Q 装载 +Q 一运 ], and at this time the pressure at the first motor is the largest, so p2=p 一运 , and Q 装载 =a 装载 I 装载 +b 装载 , Q 一运 =a 一运 I 一运 +b 一运 , then P 运输 =p 一运 *[(a 装载 I 装载 +b 装载 )+(a 一运 I 一运 +b 一运 )], thus we can get:

[0088] It can be understood that when it is detected that the pressure of the loading motor is less than or equal to the set value, the current value of the loading motor is controlled to return to normal, so that the loading motor resumes normal speed operation.

[0089] In addition, if Figure 6 As shown, another embodiment of the present invention further provides a power flow control system for a hydraulic system of a cantilever roadheader, preferably using the power flow control method described above, the system comprising:

[0090] The current acquisition module is used to detect the operating current of the pump station motor in real time during the excavation operation and determine whether the pump station motor is overloaded;

[0091] An overload protection time calculation module is used to calculate the overload protection time of the pump station motor based on the overload current value and the rated current value when the pump station motor is overloaded;

[0092] The shutdown control module is used to determine whether the duration of the pump station motor overload reaches the overload protection time. If so, the pump station motor is controlled to automatically shut down.

[0093] It can be understood that the power flow control system of the boom tunnel boring machine hydraulic system of this embodiment does not limit the power of a single variable displacement piston pump during tunneling operations. When any of the travel system, boom system, and loading and transport system functions as a single system, the full power of the pump station motor can be provided to the single system, enabling the single system to operate at maximum efficiency, significantly improving the construction efficiency of the single system. Furthermore, during tunneling operations, the operating current of the pump station motor is detected in real time to determine whether the pump station motor is overloaded. When the pump station motor is overloaded, the overload protection time of the pump station motor is calculated based on the overload current value and the rated current value. This allows the overload protection time of the pump station motor to be accurately calculated under different overload conditions. The pump station motor is automatically shut down only when the duration of the overload reaches the overload protection time. At the same time, the traveling arm system and loading and transport system in the hydraulic system of the cantilever tunnel boring machine perform compound actions and operate at high power at the same time, which is characterized by low frequency and short time. By adopting the above-mentioned motor protection program, it is possible to maximize the utilization of motor power and realize the automatic protection function of the motor. Especially in the face of complex geological environments, the speed of cutting and slag discharge can be guaranteed by short-term overload of the pump station motor, which greatly improves the overall construction efficiency.

[0094] In addition, the power flow control system further comprises:

[0095] The anti-stuck control module is used to detect the pressure of the first transport motor in the loading and transport system in real time. When it is detected that the pressure value of the first transport motor exceeds the set value, the current value of the loading motor link in the second electric proportional multi-way valve is controlled to decrease to reduce the input flow of the loading motor.

[0096] In addition, another embodiment of the present invention further provides a cantilever-type roadheader, which preferably adopts the power flow control system as described above.

[0097] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A power flow control method for a boom-type tunnel boring machine hydraulic system, wherein the boom-type tunnel boring machine hydraulic system comprises a pump station motor (1), a first variable piston pump (2), a second variable piston pump (3), a first electric proportional multi-way valve (4), a second electric proportional multi-way valve (5), a travel motor (6), a cutting arm lifting cylinder (7), a cutting arm rotating cylinder (8), a loading motor (9), a first travel motor (10) and a second travel motor (11), wherein the pump station motor (1) drives the first variable piston pump (2) and the second variable piston pump (3) in series, and the first variable piston pump (2) is connected to the first electric proportional multi-way valve (4). The second variable piston pump (3) is connected to the second electric proportional multi-way valve (5). The working links of the first electric proportional multi-way valve (4) include a walking link, a cutting and lifting link, and a cutting and rotating link. The working links of the second electric proportional multi-way valve (5) include a loading motor link, a first transport motor link, and a second transport motor link. The walking motor (6) is an actuator of the walking system. The cutting arm lifting cylinder (7) and the cutting arm rotating cylinder (8) are actuators of the boom system. The walking system and the boom system constitute a walking boom system. The loading motor (9), the first transport motor (10), and the second transport motor (11) are actuators of the loading and transport system. Includes the following: During the tunneling operation, the power of a single variable displacement plunger pump is not limited, and the working current of the pump station motor is detected in real time to determine whether the pump station motor is overloaded; When the pump station motor is overloaded, the overload protection time of the pump station motor is calculated based on the overload current value and the rated current value; Determine whether the duration of the pump station motor overload reaches the overload protection time. If so, the pump station motor will be automatically shut down. return Includes the following: Real-time detection of the pressure of the first motor in the loading and transporting system. When it is detected that the pressure value of the first motor exceeds the set value, the current value of the loading motor link in the second electric proportional multi-way valve is controlled to decrease to reduce the input flow of the loading motor. In particular, when the motor is overloaded, it is necessary to prioritize the flow and power of each motor in the loading and transporting system, and the flow and power of the second motor remain unchanged during operation; The current value of the loading motor is controlled based on the following formula: Among them, I 装载 Indicates the current value of the motor in the second electric proportional multi-way valve, P 运输 It represents the sum of the power output from the second variable piston pump to the loading motor and the first transport motor, which is a constant value. 一运 Indicates the pressure value of a motor, a 装载 and b 装载 Indicates the two constants used to calculate the output flow of the motor link in the second electric proportional multi-way valve, a 一运 and b 一运 Indicates the two constants used to calculate the output flow of the first motor in the second electric proportional multi-way valve, I 一运 Indicates the current value of a motor in the second electric proportional multi-way valve.

2. The power flow control method of the hydraulic system of a cantilever roadheader according to claim 1, characterized in that: The overload protection time of the pump station motor is calculated based on the following formula: Where, t represents the overload protection time, I a Indicates the overload current value, I b Indicates the rated current value.

3. The power flow control method of the hydraulic system of a cantilever roadheader according to claim 1, characterized in that: When the duration of the pump station motor overload does not reach the overload protection time, the following also include: The current value of the working link corresponding to the walking system and / or boom system in the first electric proportional multi-way valve is controlled to decrease, so as to reduce the input flow of the walking system and / or boom system, and control the input flow of the loading and transportation system to remain unchanged.

4. The power flow control method of the hydraulic system of a cantilever roadheader according to claim 3, characterized in that: When the traveling system and the loading and transporting system work simultaneously, the current value of the traveling link in the first electric proportional multi-way valve is controlled based on the following formula: Among them, I 行走 Indicates the current value of the first electric proportional multi-way valve, c indicates the overload coefficient, P 额 Indicates the rated output power of the pump station motor, p2 indicates the outlet pressure of the second variable piston pump, p1 indicates the outlet pressure of the first variable piston pump, a 行走 and b 行走 Indicates the two constants used to calculate the output flow of the traveling link in the first electric proportional multi-way valve, n represents the number of working links working simultaneously in the second electric proportional multi-way valve, I i Indicates the current value of the i-th working link in the second electric proportional multi-way valve, a i and b i They represent the two constants used to calculate the output flow of the i-th working unit.

5. The power flow control method of the hydraulic system of a cantilever roadheader according to claim 3, characterized in that: When the cutting arm lifting cylinder of the boom system and the loading and transporting system work simultaneously, the current value of the cutting lifting link in the first electric proportional multi-way valve is controlled based on the following formula: Among them, I 举升 Indicates the current value of the cut-off lifting link in the first electric proportional multi-way valve, c indicates the overload coefficient, P 额 Indicates the rated output power of the pump station motor, p2 indicates the outlet pressure of the second variable piston pump, p1 indicates the outlet pressure of the first variable piston pump, a 举升 and b 举升 Indicates the two constants used to calculate the output flow of the cut-off lifting link in the first electric proportional multi-way valve, n represents the number of working links working simultaneously in the second electric proportional multi-way valve, I i Indicates the current value of the i-th working link in the second electric proportional multi-way valve, a i and b i They represent the two constants used to calculate the output flow of the i-th working unit.

6. The power flow control method of the hydraulic system of a cantilever roadheader according to claim 3, characterized in that: When the cutting arm rotary cylinder of the boom system and the loading and transporting system work simultaneously, the current value of the cutting rotary link in the first electric proportional multi-way valve is controlled based on the following formula: Among them, I 回转 Indicates the current value of the cut-off rotary link in the first electric proportional multi-way valve, c indicates the overload coefficient, P 额 Indicates the rated output power of the pump station motor, p2 indicates the outlet pressure of the second variable piston pump, p1 indicates the outlet pressure of the first variable piston pump, a 回转 and b 回转 Indicates two constants used to calculate the output flow of the cut-off rotary link in the first electric proportional multi-way valve, n represents the number of working links working simultaneously in the second electric proportional multi-way valve, I i Indicates the current value of the i-th working link in the second electric proportional multi-way valve, a i and b i They represent the two constants used to calculate the output flow of the i-th working unit.

7. A power flow control system for a hydraulic system of a cantilever roadheader, adopting the power flow control method according to any one of claims 1 to 6, characterized in that: include: The current acquisition module is used to detect the operating current of the pump station motor in real time during the excavation operation and determine whether the pump station motor is overloaded; An overload protection time calculation module is used to calculate the overload protection time of the pump station motor based on the overload current value and the rated current value when the pump station motor is overloaded; The shutdown control module is used to determine whether the duration of the pump station motor overload reaches the overload protection time. If so, the pump station motor is controlled to automatically shut down.

8. A cantilever type tunnel boring machine, characterized in that: A power flow control system as claimed in claim 7 is employed.

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