Scraper power loading control system

Abstract

The present invention discloses a power loading control system for a scraper, which belongs to the technical field of mining equipment. The integrated valve block in the system of the present invention includes two pipelines arranged in parallel, a loading solenoid valve and a start protection solenoid valve are sequentially arranged on the pipeline near the output end of the gear pump, and a pressure-adjustable loading relief valve and a relief valve are sequentially arranged on the other pipeline. An oil circuit is arranged between the loading solenoid valve and the start protection solenoid valve, and between the loading relief valve and the relief valve to connect the two parallel pipelines, and a fan motor is connected to the oil circuit to form a hydraulic circuit. When the engine is idling, the loading relief valve is adjusted to increase the loading power of the gear pump. The control system of the present invention automatically loads power to the engine when the engine is idling, so that the power increases to a level that the exhaust gas after-treatment device can be turned on. When the engine is running at normal speed, the system automatically stops working without causing additional power consumption, and the heat energy generated by the power loading can be exchanged into the air.

Description

Technical Field

[0001] The present invention belongs to the technical field of mining machinery and equipment, and more specifically, relates to a power loading control system for a scraper. Background Art

[0002] As the global mining industry continues to prioritize employee safety, emission standards for underground trackless equipment have become increasingly stringent in recent years. This is to prevent underground workers from inhaling large amounts of nitrogen oxides from engine exhaust. Europe has the Euro V engine emission standard, while my country has the National IV standard. The United States has its own EPA standard system. Some American mines also purchase mining equipment with Euro V engines.

[0003] However, the Euro V engine standard for scraper loaders primarily defines exhaust treatment during normal operation; exhaust treatment during idling is not covered by the standard. Therefore, when US mining companies purchase scrapers equipped with Euro V engines, the exhaust aftertreatment system may not activate during idling due to low engine load. If operating conditions require the engine to idle for extended periods, without exhaust treatment by the aftertreatment system, nitrogen oxide levels in the air could exceed US underground mining standards. Miners' body alarms would sound a warning, and according to US regulations, the miners would be immediately brought to the surface. Consequently, the resulting downtime would cause significant losses to the mining company.

[0004] In summary, how to overcome the deficiency that the exhaust gas after-treatment device of the existing scraper cannot work normally when idling is a technical problem that needs to be solved urgently in the existing technology. Summary of the Invention

[0005] 1. Technical problem to be solved by the invention

[0006] The present invention overcomes the deficiency of the existing scraper in that the exhaust gas after-treatment device cannot work normally when idling, and provides a scraper power loading control system. When the engine is idling, the system automatically loads power to the engine, so that the power increases to a level that can open the exhaust gas after-treatment device. When the engine is running at normal speed, the system automatically stops working and no longer loads the engine, which does not cause additional power consumption, and the heat energy generated by the power loading is exchanged to the air by the radiator.

[0007] 2. Technical solution

[0008] In order to achieve the above object, the technical solution provided by the present invention is:

[0009] The power loading control system for a scraper of the present invention includes an engine driving an exhaust gas after-treatment device and a gear pump connected to the engine output shaft. The engine drives a fan motor through the gear pump to drive the fan to rotate. An integrated valve block is provided on the pipeline connecting the fan motor and the gear pump.

[0010] The integrated valve block includes two pipelines arranged in parallel. A loading solenoid valve and a starting protection solenoid valve are arranged in sequence on the pipeline close to the output end of the gear pump. A pressure-adjustable loading relief valve and a relief valve are arranged in sequence on the other pipeline. An oil circuit is set between the loading solenoid valve and the starting protection solenoid valve, and between the loading relief valve and the relief valve to connect the two parallel pipelines, and the fan motor is connected to the oil circuit to form a hydraulic circuit. When the engine is idling, the loading relief valve is adjusted to increase the loading power of the gear pump until the loading power can be fed back to the engine to drive the exhaust after-treatment device to work.

[0011] As a further improvement of the present invention, the loading solenoid valve is a two-position, two-way normally open solenoid valve.

[0012] As a further improvement of the present invention, the start-up protection solenoid valve is a two-position, two-way normally closed solenoid valve.

[0013] As a further improvement of the present invention, a first pressure measuring port and a second pressure measuring port are respectively provided at the front and rear ends of the loading relief valve, and the pressure value of the loading relief valve is adjusted according to the pressure measurement results.

[0014] As a further improvement of the present invention, the maximum pressure value of the loading overflow valve is set to 140 bar.

[0015] As a further improvement of the present invention, the rated flow of the loading solenoid valve is greater than the output flow of the gear pump.

[0016] As a further improvement of the present invention, the displacement of the gear pump is greater than the displacement of the fan motor, so as to increase the speed regulation range of the fan motor.

[0017] As a further improvement of the present invention, the sum of the pressure regulating upper limits of the loading relief valve and the relief valve does not exceed the pressure value limit of the gear pump.

[0018] As a further improvement of the present invention, a radiator is provided at the output end of the overflow valve, and the radiator is connected to the fan motor.

[0019] As a further improvement of the present invention, the overflow valve is an adjustable valve, and the power of the fan motor is adjusted by adjusting the overflow valve.

[0020] As a further improvement of the present invention, the pressure value of the overflow valve is calibrated to 110 bar.

[0021] 3. Beneficial effects

[0022] Compared with the prior art, the technical solution provided by the present invention has the following significant effects:

[0023] (1) The power loading control system of the scraper loader of the present invention automatically loads the engine with power when the engine is idling, so that the power increases to a level that can open the exhaust gas after-treatment device. When the engine is running at normal speed, the system automatically stops working and no longer loads the engine, which does not cause additional power consumption, and the heat energy generated by the power loading is exchanged to the air by the radiator.

[0024] (2) In the power loading control system of the scraper of the present invention, the rated flow of the loading solenoid valve far exceeds the output flow of the gear pump, so that the system has a loading function without consuming additional power.

[0025] (3) The power loading control system of the scraper of the present invention uses a very simple pressure regulation method of the loading overflow valve to realize the power loading of the engine. The adjustment is convenient, the loading power value is accurately adjusted, and a wide range of loading power adjustment can be realized.

[0026] (4) The power loading control system of the scraper of the present invention can adjust the overflow valve to increase the speed of the fan and improve the heat dissipation power of the radiator if the hydraulic oil temperature rises too quickly due to the loading system, thereby protecting the system.

[0027] (5) In the power loading control system of the scraper of the present invention, the displacement of the gear pump is greater than that of the fan motor, which can increase the speed regulation range of the fan motor and even exceed the engine speed, thereby improving the heat dissipation power and avoiding damage to the engine due to overheating.

[0028] (6) In the power loading control system of the scraper of the present invention, the sum of the upper pressure limit values ​​of the loading relief valve and the relief valve does not exceed the pressure limit of the gear pump to avoid damage to the gear pump caused by improper pressure regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a working principle diagram of the scraper power loading control system of the present invention.

[0030] Reference numerals:

[0031] 1. Loading solenoid valve; 2. Loading relief valve; 3. Start protection solenoid valve; 4. Relief valve; 5. Integrated valve block; 6. First pressure measuring port; 7. Second pressure measuring port; 8. Gear pump; 9. Fuel tank; 10. Radiator; 11. Fan motor; 12. Fan. DETAILED DESCRIPTION

[0032] In order to further understand the content of the present invention, the present invention is described in detail with reference to the accompanying drawings and embodiments.

[0033] The power loading control system for a scraper of the present invention includes an engine that drives an exhaust gas after-treatment device, and a gear pump 8 connected to the engine output shaft. The engine drives a fan motor 11 through the gear pump 8 to drive a fan 12 to rotate. An integrated valve block 5 is provided on the pipeline connecting the fan motor 11 and the gear pump 8.

[0034] The integrated valve block 5 includes two pipelines arranged in parallel. A loading solenoid valve 1 and a starting protection solenoid valve 3 are arranged in sequence on the pipeline near the output end of the gear pump 8. A pressure-adjustable loading relief valve 2 and a relief valve 4 are arranged in sequence on the other pipeline. An oil circuit is set between the loading solenoid valve 1 and the starting protection solenoid valve 3, and between the loading relief valve 2 and the relief valve 4 to connect the two parallel pipelines, and the fan motor 11 is connected to the oil circuit to form a hydraulic circuit. When the engine is idling, the loading relief valve 2 is adjusted to increase the loading power of the gear pump 8 until the loading power can be fed back to the engine to drive the exhaust after-treatment device to work.

[0035] Specifically in this embodiment, the loading solenoid valve 1 is a two-position, two-position normally open solenoid valve, that is, when power is not supplied, the oil can flow directly from the input port to the output port of the loading solenoid valve 1, and when power is supplied, the oil cannot flow from the input port to the output port of the loading solenoid valve 1.

[0036] In addition, the rated flow of the loading solenoid valve 1 in this embodiment is greater than the output flow of the gear pump 8, and no significant pressure loss will be caused when the oil flows from the input port to the output port. The loading solenoid valve 1 in this embodiment enables the control system to have a loading function without consuming additional power.

[0037] Furthermore, in this embodiment, the start protection solenoid valve 3 is a two-position, two-way normally closed solenoid valve, that is, when power is not supplied, the oil cannot flow from the input port to the output port of the start protection solenoid valve 3. After power is supplied, the oil can flow directly from the input port to the output port of the start protection solenoid valve 3.

[0038] As an implementation mode, in this embodiment, a first pressure measuring port 6 and a second pressure measuring port 7 are respectively provided at the front and rear ends of the loading relief valve 2 , and the pressure value of the loading relief valve 2 is adjusted according to the pressure measurement results.

[0039] Specifically, in this embodiment, the maximum pressure value of the loading relief valve 2 is set to 140 bar.

[0040] Existing scrapers cannot operate properly due to low load power when idling. To solve this problem, the scraper power loading control system of the present invention can increase the load on the engine when idling to increase the engine output power.

[0041] Specifically, when the engine is idling, the system automatically applies power to the engine, increasing the power to a level sufficient to activate the exhaust aftertreatment device. When the engine is running at normal speed, the system automatically stops, no longer applying power to the engine and causing no additional power consumption. The heat generated by the power application is then transferred to the air via the radiator.

[0042] The power loading control system of the scraper of the present invention can realize the power loading of the engine by using a very simple pressure regulation method for the loading overflow valve 2. The adjustment is convenient, the loading power value is accurately adjusted, and a wide range of loading power adjustment can be realized.

[0043] In addition, in order to increase the speed regulation range of the fan motor 11, the displacement of the gear pump 8 in this embodiment is greater than the displacement of the fan motor 11, so that the speed regulation range of the fan motor 11 can be increased or even exceed the engine speed, thereby improving the heat dissipation power.

[0044] Preferably, in this embodiment, the sum of the upper pressure limits of the loading relief valve 2 and the relief valve 4 does not exceed the pressure limit of the gear pump 8, otherwise the gear pump 8 may be damaged due to improper pressure regulation.

[0045] As an implementation, in this embodiment, a radiator 10 is provided at the output end of the relief valve 4 and is connected to a fan motor 11. If the hydraulic oil temperature rises too quickly due to the loading system, the relief valve 4 can be adjusted to increase the speed of the fan 12, thereby increasing the heat dissipation efficiency of the radiator 10.

[0046] Preferably, in this embodiment, the overflow valve 4 is an adjustable valve, which adjusts the power of the fan motor 11 by adjusting the oil inlet pressure of the fan motor 11, thereby controlling the rotation speed of the fan 12.

[0047] Specifically in this embodiment, the pressure value of the relief valve 4 is calibrated to 110 bar.

[0048] The following describes in detail the process of controlling the exhaust gas treatment device when the engine is idling, combined with the working principle diagram of the scraper power loading control system. The details are as follows:

[0049] In the power loading control system of the scraper of this embodiment, when the engine is just started, the gear pump 8 is driven by the power take-off port of the Euro V engine to operate, sucking the hydraulic oil in the hydraulic oil tank 9 and pressing it into the integrated valve block 5. At this time, the starting protection solenoid valve 3 is energized at the same time, and the oil first enters the loading solenoid valve 1, flows to the output port through the input port of the loading solenoid valve 1, and then enters the input port of the starting protection solenoid valve 3 and flows back to the oil tank 9.

[0050] At this time, the loading control system has no pressure, the fan 12 does not rotate, and the engine is required to be no-load when starting. Therefore, when the overall system load is very low, the smooth start of the engine can be effectively guaranteed.

[0051] Then, 10 seconds after the engine starts, the start protection solenoid valve 3 loses power and remains de-energized until the vehicle shuts down. At this point, the oil from the gear pump 8 flows out through the loading solenoid valve 1 and cannot flow back into the fuel tank through the start protection solenoid valve 3. Instead, it flows to the fan motor 11 and the relief valve 4. The oil drives the fan motor 11 to rotate. Once the pressure reaches the set pressure of the relief valve 4, the excess oil flows through the relief valve 4 into the fuel tank 9.

[0052] At this time, the fan 12 keeps blowing the radiator 10 at a constant speed, ensuring that the radiator 10 works under a constant heat dissipation power.

[0053] Then, when the engine starts and remains at idle speed for 60 seconds, the loading solenoid valve 1 is energized. At this time, the oil from the gear pump 8 cannot flow out through the loading solenoid valve 1, but can only flow out through the loading relief valve 2, and then enter the fan motor 11 and the relief valve 4. The oil drives the fan motor 11 to rotate. After reaching the set pressure of the relief valve 4, the excess oil enters the fuel tank 9 through the relief valve 4. Because all the oil from the gear pump 8 must pass through the loading relief valve 2, and the power consumption of the gear pump 8 is proportional to the flow rate and pressure of the oil, and the flow rate is constant under idling conditions, it is equivalent to the power consumption of the gear pump 8 being proportional to the set pressure of the loading relief valve 2.

[0054] It's worth emphasizing that, in this state, using pressure gauges 6 and 7 to set a pressure value on the loading relief valve 2 is equivalent to calibrating an additional loading power value for the engine, thereby activating the engine exhaust aftertreatment device. Specifically, in this embodiment, this additional loading power is converted into heat in the hydraulic oil, which is ultimately transferred to the air by the radiator 10.

[0055] Finally, when the engine leaves the idle state, the loading solenoid valve 1 loses power. At this time, the oil from the gear pump 8 flows out through the loading solenoid valve 1, and the oil does not pass through the loading overflow valve 2. The rated flow of the loading solenoid valve 1 is much greater than the pump output flow. The additional back pressure introduced is relatively small and will not cause additional power loss. It only drives the fan motor 11 and returns to the oil tank 9 through the radiator 10.

[0056] To sum up, the power loading control system of the scraper loader of the present invention uses a hydraulic control system to force all the flow output by the pump in the system to overflow through the relief valve 4, and converts all the pump output energy into heat energy for consumption. According to the pump output power being equal to the product of pressure and flow, the pump output power can be adjusted by adjusting the pressure of the relief valve 4. The gear pump 8 is directly driven by the engine power take-off port, so that the engine loading power can be adjusted by adjusting the pressure of the relief valve 4.

[0057] Specifically, by calibrating the relief valve 4 to an appropriate pressure value, the engine's idle power loading is just enough to open the engine exhaust after-treatment device. Furthermore, the excess heat generated by the power loading enters the hydraulic oil and is dissipated by the hydraulic oil cooling system into the air.

[0058] At the same time, the power loading control system of the scraper of the present invention, when the engine is running at normal speed, is switched by the large-flow electromagnetic reversing valve, so that the pump output flow no longer passes through the loading overflow valve 2, that is, the engine is no longer loaded, and no additional power consumption is caused to the engine. The entire loading system has low fuel consumption and saves costs.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. The power loading control system of the scraper is characterized by: The invention comprises an engine for driving an exhaust gas after-treatment device, and a gear pump (8) connected to an output shaft of the engine, wherein the engine drives a fan motor (11) through the gear pump (8) to drive a fan (12) to rotate, and an integrated valve block (5) is provided on a pipeline connecting the fan motor (11) and the gear pump (8); The integrated valve block (5) includes two parallel pipelines, a loading solenoid valve (1) and a start protection solenoid valve (3) are sequentially arranged on the pipeline near the output end of the gear pump (8), and a pressure-adjustable loading overflow valve (2) and an overflow valve (4) are sequentially arranged on the other pipeline. An oil circuit is arranged between the loading solenoid valve (1) and the start protection solenoid valve (3), and between the loading overflow valve (2) and the overflow valve (4) to connect the two parallel pipelines, and the fan motor (11) is connected to the oil circuit to form a hydraulic circuit. When the engine is idling, the loading overflow valve (2) is adjusted to increase the loading power of the gear pump (8) until the loading power can be fed back to the engine to drive the exhaust gas after-treatment device to work; The loading solenoid valve (1) is a two-position, two-position normally open solenoid valve; The start protection solenoid valve (3) is a two-position, two-way normally closed solenoid valve; The overflow valve (4) is an adjustable valve.

2. The power loading control system for a scraper according to claim 1, characterized in that: A first pressure measuring port (6) and a second pressure measuring port (7) are respectively provided at the front and rear ends of the loading relief valve (2), and the pressure value of the loading relief valve (2) is adjusted according to the pressure measurement results.

3. The power loading control system for a scraper according to claim 2, characterized in that: The maximum pressure value of the loading relief valve (2) is set to 140 bar.

4. The scraper power loading control system according to claim 1, characterized in that: The rated flow rate of the loading solenoid valve (1) is greater than the output flow rate of the gear pump (8).

5. The scraper power loading control system according to claim 1, characterized in that: The displacement of the gear pump (8) is greater than the displacement of the fan motor (11), so as to increase the speed regulation range of the fan motor (11).

6. The scraper power loading control system according to any one of claims 1 to 5, characterized in that: The sum of the pressure regulation upper limits of the loading relief valve (2) and the relief valve (4) does not exceed the pressure value limit of the gear pump (8).

7. The scraper power loading control system according to claim 6, characterized in that: A radiator (10) is provided at the output end of the overflow valve (4), and the radiator (10) is connected to the fan motor (11).

8. The scraper power loading control system according to claim 7, characterized in that: The pressure value of the overflow valve (4) is calibrated to 110 bar.

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