Self-adaptive screen scarifier hydraulic system and control method

Abstract

The invention relates to a self-adaptive screen scarifier hydraulic system and a control method, and belongs to the technical field of excavator hydraulic pressure. The hydraulic system comprises a chain pulling motor; the walking speed of the walking motor can be controlled by controlling the pressure of the control end of the second reversing valve; an oil outlet of the proportional electromagnetic valve is connected with the control end of the second reversing valve, and the pressure of the control end of the second reversing valve can be controlled by adjusting the opening degree of a valve element of the proportional electromagnetic valve; the pressure sensor and the rotating speed sensor are respectively used for detecting the oil inlet pressure and the actual rotating speed of the chain pulling motor; and the controller is configured to control the control current of the proportional electromagnetic valve according to the detected oil inlet pressure and the actual rotating speed. The oil inlet pressure and the real-time rotating speed of the scraper chain motor of the screen scarifier are monitored, so that the walking speed of a main machine is adaptively controlled, and the conditions of working lagging and shutdown under overflow pressure can be effectively reduced or eliminated.

Description

Technical Field

[0001] The present invention relates to a hydraulic system and a control method for an adaptive ballast cleaning machine, belonging to the technical field of hydraulic technology for excavators. Background Art

[0002] With the development of railway tracks, the maintenance of tracks is crucial. The ballast cleaning machine excavator attachment is currently widely used and can realize the cleaning of the ballast under the track. During the operation of the ballast cleaning machine, an operator with rich experience is required to control the cooperation between the excavator and the ballast cleaning machine attachment to achieve the cleaning of the ballast.

[0003] During the operation of the existing ballast cleaning machine, while the operator controls the movement of the excavator, it is also necessary to control the operation of the ballast cleaning machine to achieve the function of cleaning the ballast. However, the size and arrangement density of the ballast under the railway track are different, and the working conditions are relatively complex. During the operation, when encountering ballast with difficult cleaning, the system pressure increases and the motor speed decreases. At this time, if the operation of the excavator is improper, it is easy to reach the overflow pressure of the chain pulling motor, resulting in the chain pulling motor stopping rotating. At this time, the operator needs to reverse the chain pulling motor or move the bucket rod and boom. During the cleaning process, if frequent jams occur, the working efficiency will be greatly reduced. The jams will have a greater impact on the chain and gears, and there is a risk of chain detachment, which has a great impact on railway maintenance work. Summary of the Invention

[0004] The purpose of the present invention is to provide a hydraulic system and a control method for an adaptive ballast cleaning machine, which can judge the cleaning difficulty of the ballast according to the inlet oil pressure and the real-time speed of the chain pulling motor, and control the valve core opening of the proportional solenoid valve to adjust the walking speed according to the cleaning difficulty of the ballast, so as to achieve the purpose of reducing the jams of the chain pulling motor.

[0005] The present invention is solved by adopting the following technical solutions: In a first aspect, the present invention provides a hydraulic system for an adaptive ballast cleaning machine, which includes: A chain pulling motor; A walking motor and a second reversing valve, and the walking speed of the walking motor can be controlled by controlling the pressure at the control end of the second reversing valve; A proportional solenoid valve, the oil outlet of the proportional solenoid valve is connected to the control end of the second reversing valve, and the pressure at the control end of the second reversing valve can be controlled by adjusting the valve core opening of the proportional solenoid valve; A pressure sensor and a speed sensor, which are respectively used to detect the inlet oil pressure and the actual speed of the chain pulling motor; A controller, which is configured to control the control current of the proportional solenoid valve according to the detected inlet oil pressure and actual speed, so as to adjust the valve core opening of the proportional solenoid valve, thereby controlling the pressure at the control end of the second reversing valve.

[0006] Optionally, the proportional solenoid valve has a left position and a right position. When the proportional solenoid valve is in the left position, its oil outlet is blocked. When the proportional solenoid valve is in the right position, its oil outlet is in communication with the control end of the second reversing valve.

[0007] Optionally, the controller can also control the spool position of the proportional solenoid valve by controlling the control current of the proportional solenoid valve. By switching the spool position of the proportional solenoid valve, the start / stop and traveling direction of the traveling motor can be controlled.

[0008] Optionally, the second reversing valve has a left control end and a right control end. The proportional solenoid valve includes a first proportional solenoid valve and a second proportional solenoid valve. The first proportional solenoid valve and the second proportional solenoid valve respectively control the left control end and the right control end of the second reversing valve. When the left control end of the second reversing valve is supplied with oil, the second reversing valve is in the left position. When the right control end of the second reversing valve is supplied with oil, the second reversing valve is in the right position. By switching the spool position of the second reversing valve, the traveling direction of the traveling motor can be switched.

[0009] Optionally, a throttle valve is provided between the oil outlet of the proportional solenoid valve and the control end of the second reversing valve.

[0010] Optionally, it further includes: A first reversing valve group, including a first reversing valve; The oil inlet of the first reversing valve is connected to a pressure oil source. The first working oil port and the second working oil port of the first reversing valve are respectively used to drive the chain scraping motor to rotate forward and backward.

[0011] Optionally, the first reversing valve has a left control end and a right control end. When the left control end of the first reversing valve is supplied with oil, the first reversing valve is in the left position. When the right control end of the first reversing valve is supplied with oil, the first reversing valve is in the right position. By switching the spool position of the first reversing valve, the feeding direction of the chain scraping motor can be switched. The control end of the first reversing valve is controlled by external hydraulics.

[0012] In a second aspect, the present invention provides a control method for an adaptive screening machine hydraulic system, which is carried out based on the above-mentioned adaptive screening machine hydraulic system. The control method includes: Obtain the detected inlet oil pressure and actual rotational speed; If the inlet oil pressure is greater than the corresponding preset threshold and the actual rotational speed is less than the corresponding preset threshold, reduce the control end pressure of the second reversing valve according to a preset rule to reduce the traveling speed. If the actual rotational speed is measured to be zero or the actual rotational speed is greater than the corresponding preset threshold during the process of reducing the traveling speed, stop supplying oil to the control end of the second reversing valve and stop traveling; If the inlet oil pressure is less than the corresponding preset threshold and the actual rotational speed is greater than the corresponding preset threshold, increase the control end pressure of the second reversing valve according to a preset rule to increase the traveling speed. If the actual rotational speed is measured to be less than the corresponding preset threshold during the process of increasing the traveling speed, stop supplying oil to the control end of the second reversing valve and stop traveling.

[0013] Optionally, if the detected inlet oil pressure is greater than the motor overflow pressure value, stop supplying oil to the control end of the second reversing valve and stop traveling.

[0014] Optionally, the relationship formula between the control current of the proportional solenoid valve, the inlet oil pressure, and the traveling speed is as follows: I = ψP 实际 V = kI In the formula, I represents the control current of the proportional solenoid valve, ψ represents the inverse ratio coefficient, P 实际 represents the real-time rotational speed, V represents the traveling speed, and k represents the direct ratio coefficient.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention monitors the inlet oil pressure and the real-time rotational speed of the cleaning chain motor of the screening machine to judge the cleaning difficulty of the ballast in real time, and can adaptively control the traveling speed of the main machine by controlling the control current of the proportional solenoid valve. The control is stable and can effectively reduce or eliminate work jamming and the situation of stopping due to overflow pressure, improving the work efficiency and the service life of the screening machine chain and motor. Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of the adaptive screening machine hydraulic system in Embodiment 1; Figure 2 is a schematic flowchart of the control method of the adaptive screening machine hydraulic system in Embodiment 2; Reference numerals in the figure: 1, cleaning chain motor; 2, first reversing valve group; 3, rotational speed sensor; 4, pressure sensor; 5, controller; 6, second proportional solenoid valve, 7, first proportional solenoid valve; 8, first throttle valve; 9; traveling motor; 10, second reversing valve; 11, second throttle valve. Detailed Embodiments

[0017] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality" is two or more. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected to" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0018] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and cannot be used to limit the protection scope of the present invention. Embodiment

[0019] Combined with Figure 1 , this embodiment provides an adaptive ballast cleaning machine hydraulic system, which includes a scraping chain motor 1, a first reversing valve group 2, a speed sensor 3, a pressure sensor 4, a first proportional solenoid valve 7, a second proportional solenoid valve 6, a first throttle valve 8, a traveling motor 9, a second reversing valve 10, a second throttle valve 11, and a controller 5. The first reversing valve group 2 includes a first reversing valve; the oil inlet of the first reversing valve is connected to an external pressure oil source, and the first working oil port and the second working oil port of the first reversing valve are respectively used to drive the scraping chain motor 1 to rotate forward and backward. The first reversing valve has a left control end and a right control end. When the left control end of the first reversing valve is supplied with oil, the first reversing valve is in the left position. When the right control end of the first reversing valve is supplied with oil, the first reversing valve is in the right position. By switching the spool position of the first reversing valve, the feeding direction of the scraping chain motor 1 can be switched. The control end of the first reversing valve is controlled by external hydraulics, that is, the X1 pilot port and the X2 pilot port connected to the left control end and the right control end of the first reversing valve in the figure.

[0020] In this embodiment, the traveling speed of the traveling motor 9 can be controlled by controlling the pressure at the control end of the second reversing valve 10; the oil outlet of the proportional solenoid valve is connected to the control end of the second reversing valve 10, and the pressure at the control end of the second reversing valve 10 can be controlled by adjusting the opening degree of the spool of the proportional solenoid valve; in a specific embodiment, a throttle valve is provided between the oil outlet of the proportional solenoid valve and the control end of the second reversing valve 10 to protect the valve body and the oil circuit.

[0021] In addition, the pressure sensor 4 and the rotational speed sensor 3 are respectively used to detect the inlet oil pressure and the actual rotational speed of the chain pulling motor 1; the controller 5 is configured to control the control current of the proportional solenoid valve according to the detected inlet oil pressure and the actual rotational speed so as to adjust the opening degree of the spool of the proportional solenoid valve, thereby controlling the pressure at the control end of the second reversing valve 10. In fact, the controller 5 can control the opening degree of the spool of the proportional solenoid valve by controlling the magnitude of the control current of the proportional solenoid valve, thereby controlling the pressure at the control end of the second reversing valve 10, and further controlling the traveling speed of the traveling motor 9.

[0022] Specifically, the working principle of controlling the control current of the proportional solenoid valve according to the detected inlet oil pressure and the actual rotational speed in this embodiment is as follows: when the inlet oil pressure of the chain pulling motor 1 is greater than the preset threshold value, it is determined that the chain pulling motor 1 is blocked more severely. Here, the ballast is more difficult to clean, but the chain pulling motor does not stop rotating. At this time, the controller 5 reduces the current value of the proportional solenoid valve to reduce the opening degree of the spool of the proportional solenoid valve, thereby reducing the pressure at the control end of the second reversing valve 10 (that is, the X1 pilot port or the X2 pilot port of the second reversing valve 10 in the figure), and further reducing the opening degree of the spool of the second reversing valve 10, reducing the oil inlet volume of the traveling motor 9, and finally reducing the traveling speed of the main machine, slowing down the feeding speed of the chain pulling of the screening machine, increasing the cleaning time for the more difficult-to-clean ballast, so as to reduce the jamming situation of the chain pulling motor 1. When the traveling speed is reduced and the more difficult-to-clean ballast is cleaned, the inlet oil pressure of the chain pulling motor 1 decreases, and the actual rotational speed of the chain pulling motor 1 increases. At this time, the controller 5 transmits a signal value to the proportional solenoid valve, and then further increases the traveling speed of the main machine to resume normal operation. It can be understood that in this embodiment, the traveling speed of the main machine can be adjusted by adaptively adjusting the control current of the proportional solenoid valve according to the detected values of the inlet oil pressure and the actual rotational speed, thereby reducing the jamming situation of the chain pulling motor 1.

[0023] Moreover, the proportional solenoid valve has a left position and a right position. When the proportional solenoid valve is in the left position, its oil outlet is blocked. When the proportional solenoid valve is in the right position, its oil outlet is communicated with the control end of the second reversing valve 10. The controller 5 can also control the spool position of the proportional solenoid valve by controlling the control current of the proportional solenoid valve, and can control the start and stop of the traveling motor 9 by switching the spool position of the proportional solenoid valve.

[0024] In a specific embodiment, since the travel motor 9 has two travel directions, forward and backward, the second reversing valve 10 also has two control ends corresponding to two valve positions. The second reversing valve 10 in this embodiment has a left control end and a right control end. The proportional solenoid valve includes a first proportional solenoid valve 7 and a second proportional solenoid valve 6. The first proportional solenoid valve 7 and the second proportional solenoid valve 6 correspond to the left control end and the right control end of the second reversing valve 10 respectively; the corresponding throttle valve also includes a first throttle valve 8 and a second throttle valve 11; when the left control end of the second reversing valve 10 is filled with oil, the second reversing valve 10 is in the left position, and when the right control end of the second reversing valve 10 is filled with oil, the second reversing valve 10 is in the right position. The travel direction of the travel motor 9 can be switched by switching the valve core position of the second reversing valve 10. When the travel direction of the travel motor 9 is different, the control method of the proportional solenoid valve is similar. Example

[0025] Combination Figure 2 This embodiment provides a control method for the hydraulic system of an adaptive screen cleaning machine of Embodiment 1. When the screen cleaning machine is ready to work on the railway track, the host machine mode can be adjusted to the adaptive walking mode of the screen cleaning machine. At this time, the driver does not need to operate the host walking pedal / handle. However, when encountering special circumstances and the driver is required to operate the walking, the adaptive mode stops working and switches to the manual operation mode.

[0026] When the cleaning machine is running, the oil inlet pressure of the chain motor 1 detected by the pressure sensor 4 is P 实际 (If P 实际 If there is no value, the pressure sensor needs to be checked and retested). The speed sensor 3 determines the real-time speed of the chain motor 1 to be N. 实际 (If N 实际 If there is no value, you need to check the speed sensor and retest). When the cleaning machine is in adaptive walking mode, the pressure sensor 4 and the speed sensor 3 are connected to the controller 5 for communication. The two sensors transmit signals to the controller 5. When the controller 5 determines that the pressure value and the speed value are normal (such as: P 实际 =P 设定 , N 实际 =N 设定 , the upper and lower deviation values ​​are allowed to be x). Then the controller 5 transmits an electrical signal to the first proportional solenoid valve 7, the oil ports 1 and 3 of the first proportional solenoid valve 7 are connected, and the X1 pilot port of the second reversing valve 10 enters oil, thereby pushing the valve core of the second reversing valve 10 to work in the right position. At this time, the travel motor 9 inputs high-pressure oil, so that the main machine obtains the travel speed V. When the second proportional solenoid valve 6 works, the same applies.

[0027] When the host is moving, obtain the detected oil inlet pressure and actual rotational speed; if the oil inlet pressure is greater than the corresponding preset threshold and the actual rotational speed is less than the corresponding preset threshold, reduce the control end pressure of the second reversing valve 10 according to a preset rule to decrease the traveling speed. If the actual rotational speed is measured to be zero or the actual rotational speed is greater than the corresponding preset threshold during the process of reducing the traveling speed, it means that the chain scraping motor 1 is abnormal and the operation needs to be stopped immediately. At this time, stop supplying oil to the control end of the second reversing valve 10 and stop the movement; if the oil inlet pressure is less than the corresponding preset threshold and the actual rotational speed is greater than the corresponding preset threshold, increase the control end pressure of the second reversing valve 10 according to a preset rule to increase the traveling speed. If the actual rotational speed is measured to be less than the corresponding preset threshold during the process of increasing the traveling speed, it means that the chain scraping motor 1 is abnormal and the operation needs to be stopped immediately. Stop supplying oil to the control end of the second reversing valve 10 and stop the movement.

[0028] In a specific embodiment, the relationship formula between the control current of the proportional solenoid valve, the oil inlet pressure, and the traveling speed is as follows: I = ψP 实际 V = kI In the formula, I represents the control current of the proportional solenoid valve, ψ represents the inverse coefficient, P 实际 represents the oil inlet pressure, V represents the traveling speed, and k represents the proportionality coefficient.

[0029] Based on the above formula, it can be obtained that during actual operation, the traveling speed V is inversely proportional to the oil inlet pressure P 实际 The greater the oil inlet pressure P 实际 , the traveling speed V will decrease with the inverse coefficient ψ and remain greater than 0. The smaller the oil inlet pressure P 实际 , the traveling speed V will increase with the inverse coefficient ψ, thereby optimizing the working state of the host in real time to maintain the use safety of the host while cleaning the ballast.

[0030] Specifically, first set the control current of the proportional solenoid valve as I, the traveling speed of the host as V. The control current of the proportional solenoid valve is proportional to the traveling speed. When the identified pressure P MAX >P 实际 >P 设定 , and it is identified that 0 < N 实际 <N 设定 , the control current of the proportional solenoid valve is I = ψP 实际 (ψ is the inverse coefficient), V = kI (k is the proportionality coefficient), V = kψP 实际 . When it is measured that P 实际 is greater, V will decrease with the inverse parameter and be greater than 0. However, if it is measured that N 实际 = 0 or N 实际 >N 设定 , then V = 0. Similarly, when 0 < P实际 <P 设定 When, and N 实际 >N 设定 When, it is determined that the ballast here is relatively easy to clean. Therefore, at this time, the 5 - controller 5 can transmit a signal to increase the host walking speed, accelerate the feeding speed of the cleaning chain of the screening machine, and improve the cleaning efficiency. When the recognized pressure 0 < P 实际 <P 设定 When, and N 实际 >N 设定 When, V = kψP 实际 , P 实际 decreases, V will increase with the inverse proportional parameter and V ≤ Vmax, but if it is measured that 0 ≤ N 实际 <N 设定 , then V = 0.

[0031] When PMAX = P actual, it proves that the screening machine is under pressure at this time. This is the limit situation. Without other conditions, directly make V = 0. The controller 5 makes the host walking stop running by transmitting a signal. At this time, the operator needs to manually judge the working condition to confirm whether work can be carried out. Among them, P 实际 represents the inlet oil pressure measured by the pressure sensor 4 in real time; N 实际 represents the real - time speed of the cleaning chain motor 1 measured by the speed sensor 3; P 设定 represents the pressure value of the preset normal working condition; N 设定 represents the speed value of the preset normal working condition. P MAX represents the motor overflow pressure value.

[0032] The above - mentioned are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. An adaptive screen cleaning machine hydraulic system, characterized in that: include: Chain motor (1); A travel motor (9) and a second reversing valve (10), wherein the travel speed of the travel motor (9) can be controlled by controlling the pressure at the control end of the second reversing valve (10); a proportional solenoid valve, wherein the oil outlet of the proportional solenoid valve is connected to the control end of the second reversing valve (10), and the pressure at the control end of the second reversing valve (10) can be controlled by adjusting the valve core opening of the proportional solenoid valve; A pressure sensor (4) and a rotation speed sensor (3), respectively used to detect the oil inlet pressure and actual rotation speed of the chain-pulling motor (1); The controller (5) is configured to control the control current of the proportional solenoid valve according to the detected oil inlet pressure and the actual rotation speed, so as to adjust the valve core opening of the proportional solenoid valve, thereby controlling the control end pressure of the second reversing valve (10).

2. The self-adaptive screen cleaning machine hydraulic system according to claim 1, characterized in that: The proportional solenoid valve has a left position and a right position. When the proportional solenoid valve is in the left position, its oil outlet is cut off. When the proportional solenoid valve is in the right position, its oil outlet is connected to the control end of the second reversing valve (10).

3. The self-adaptive screen cleaning machine hydraulic system according to claim 2, characterized in that: The controller (5) can also control the valve core position of the proportional solenoid valve by controlling the control current of the proportional solenoid valve, and can control the start and stop of the travel motor (9) by switching the valve core position of the proportional solenoid valve.

4. The self-adaptive screen cleaning machine hydraulic system according to claim 1, characterized in that: The second reversing valve (10) has a left control end and a right control end. The proportional solenoid valve comprises a first proportional solenoid valve (7) and a second proportional solenoid valve (6). The first proportional solenoid valve (7) and the second proportional solenoid valve (6) respectively control the left control end and the right control end of the second reversing valve (10). When oil flows into the left control end of the second reversing valve (10), the second reversing valve (10) is in the left position. When oil flows into the right control end of the second reversing valve (10), the second reversing valve (10) is in the right position. By switching the valve core position of the second reversing valve (10), the travel direction of the travel motor (9) can be switched.

5. The self-adaptive screen cleaning machine hydraulic system according to claim 1, characterized in that: A throttle valve is provided between the oil outlet of the proportional solenoid valve and the control end of the second reversing valve (10).

6. The self-adaptive screen cleaning machine hydraulic system according to claim 1, characterized in that: Also includes: A first reversing valve group (2), comprising a first reversing valve; The oil inlet of the first reversing valve is connected to a pressure oil source, and the first working oil port and the second working oil port of the first reversing valve are used to drive the chain-pulling motor (1) to rotate forward and reverse respectively.

7. The self-adaptive screen cleaning machine hydraulic system according to claim 6, characterized in that: The first reversing valve has a left control end and a right control end. When oil is introduced into the left control end of the first reversing valve, the first reversing valve is in the left position. When oil is introduced into the right control end of the first reversing valve, the first reversing valve is in the right position. The feeding direction of the chain motor (1) can be switched by switching the valve core position of the first reversing valve. Both the left control end and the right control end of the first reversing valve are controlled by an external hydraulic source.

8. A control method for a hydraulic system of an adaptive screen cleaning machine, characterized in that: Based on the adaptive screen cleaning machine hydraulic system according to any one of claims 1 to 7, the control method includes: Obtain the detected oil inlet pressure and actual speed; If the oil inlet pressure is greater than a corresponding preset threshold value and the actual rotation speed is less than the corresponding preset threshold value, the pressure at the control end of the second reversing valve (10) is reduced according to a preset rule to reduce the walking speed; if the actual rotation speed is measured to be zero or greater than the corresponding preset threshold value during the process of reducing the walking speed, the oil inlet to the control end of the second reversing valve (10) is stopped and walking is stopped; If the oil inlet pressure is less than the corresponding preset threshold and the actual rotation speed is greater than the corresponding preset threshold, the pressure at the control end of the second reversing valve (10) is increased according to a preset rule to increase the walking speed; if the actual rotation speed is less than the corresponding preset threshold during the process of increasing the walking speed, the oil inlet to the control end of the second reversing valve (10) is stopped and walking is stopped.

9. The control method of the hydraulic system of the adaptive screen cleaning machine according to claim 7, characterized in that: If the detected oil inlet pressure is greater than the motor overflow pressure value, the oil inlet to the control end of the second reversing valve (10) is stopped and movement is stopped.

10. The control method of the hydraulic system of the adaptive screen cleaning machine according to claim 7, characterized in that: The relationship between the control current of the proportional solenoid valve, the oil inlet pressure and the travel speed is as follows: I=ψP 实际 V=kI Where, I represents the control current of the proportional solenoid valve, ψ represents the inverse coefficient, P 实际 represents the real-time rotation speed, V represents the walking speed, and k represents the proportional coefficient.

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