SYSTEM AND METHOD FOR CONTROLLING A HYDRAULIC EXCAVATOR

Description

Technical Field

[0001] The present invention relates to a hydraulic excavator control system and method, and belongs to the technical field of hydraulic excavators.Background

[0002] Working conditions for the hydraulic excavator are extremely complicated, and loads are greatly changed. When the load of a hydraulic pump is increased, an engine increases an oil injection quantity, and an output torque is increased; due to mechanical transmission, the engine would have a relatively long hysteresis quality. The following working states would frequently occur to the engine: one is that when the engine is suddenly loaded in a low load state, the loading time would be excessively long, rendering reduction of the working efficiency; the second one is that when the engine is suddenly loaded in an idle state, a problem of black smoke would occur. Most manufacturers would reduce the loading time of the engine by changing a mixture ratio of oil to gas in a combustion chamber of the engine; however, at the same time, the problems of inadequate combustion and black smoke of the engine would occur; when the problem of the black smoke occurs when in the idle speed, most manufacturers would improve the idle rotation speed of the complete machine, rendering energy consumption and wastes. CN 104074225B discloses a hydraulic excavator power adaptive control system and method, wherein a main pump pressure signal and a pilot pressure signal are collected and the requirement of the excavator working for real-time power is calculated; the change trend of the power requirement to enable an engine to work nearby a preset power output point is conducted, and meanwhile, without any delay, state parameters of a power system is adjusted online. US 6161522 discloses a controller of an engine and a variable capacity pump performing a speedy work under a heavy load and a strong work at the critical moment, wherein at a time of increasing to the engine rotational number Na, a command is output to the TVC valve so as to become the pump absorption torque coinciding with the engine output torque curve.Summary

[0003] The purpose of the present invention is to overcome disadvantages in the prior at and provide a hydraulic excavator control system and method to solve the technical problems of reduction of the working efficiency when the engine is suddenly loaded in a low load state and the occurrence of black smoke when the engine is suddenly loaded in an idle state.

[0004] To resolve the technical problems above, the technical solution adopted in the present invention is as follows.

[0005] For a first aspect, the present invention provides a hydraulic excavator control method, including the following steps: collecting, by a controller, an oil circuit pressure signal of a hydraulic excavator, and calculating a required main pump power according to the oil circuit pressure signal; sending, by the controller, the required main pump power to an engine ECM; and first adjusting, by the engine ECM, an engine fuel injection amount according to the required main pump power, and then adjusting, by the controller, a main pump power according to the required main pump power; the time for the engine ECM to start to adjust the engine fuel injection amount is ahead of the time for the controller to start to adjust the main pump power by 0.05-0.6 seconds.

[0006] By combining with the first aspect, furthermore, the oil circuit pressure signal includes a main oil circuit pressure value of the hydraulic excavator and each pilot pressure value corresponding to a current action of the hydraulic excavator.

[0007] For a second aspect, the present invention provides a hydraulic excavator control system including a controller, an engine ECM, and an oil circuit pressure collection unit, where the engine ECM and the oil circuit pressure collection unit are respectively communicationally connected to the controller; the controller is adapted to calculate, according to an oil circuit pressure signal of a hydraulic excavator collected by the oil circuit pressure collection unit, a required main pump power of the hydraulic excavator, and is configured to send the required main pump power to the engine ECM; and the engine ECM is configured to first adjust an engine fuel injection amount according to the required main pump power, and then the controller adjusts a main pump power according to the required main pump power. the time for the engine ECM to start to adjust the engine fuel injection amount is ahead of the time for the controller to start to adjust the main pump power by 0.05-0.6 seconds.

[0008] By combining with the second aspect, furthermore, the controller is communicationally connected to the engine ECM using a CAN bus.

[0009] By combining with the second aspect, furthermore, the oil circuit pressure collection unit includes a first pressure sensor configured to collect a main oil circuit pressure value of the hydraulic excavator and a second pressure sensor configured to collect each pilot pressure value corresponding to a current action of the hydraulic excavator.

[0010] As compared with the prior art, the beneficial effects achieved by the present invention are the time for the engine ECM to start to adjust the engine fuel injection amount is earlier than the time for adjusting the main pump to the required main pump power, so as to greatly reduce a loading response time of the engine, improve a working efficiency of the whole machine, avoid the problem of black smoke from idle loading, and may further reduce an idle rotation speed of the engine and reduce fuel oil consumption. In addition, the control method further has advantages of simple implementations, low costs, and high reliability.Brief Description of the Drawings

[0011] FIG. 1 is a flowchart of a hydraulic excavator control method according to an embodiment of the present invention. FIG. 2 is a hydraulic principle diagram of a hydraulic excavator control system according to an embodiment of the present invention. FIG. 3 is a relation diagram between an engine fuel injection amount of a hydraulic excavator and time in the prior art. FIG. 4 is a relation diagram between an engine fuel injection amount of a hydraulic excavator and time according to an embodiment of the present invention.

[0012] 10-engine; 11-main pump; 12-pilot pump; 13-electromagnetic proportional valve; 14-main value; 15-hydraulic pilot handle; 16-controller; 17-traveling valve core; 18-rotation value core; 19-moving arm valve core; 20-scraper pan valve core; 21-pan rod valve core; and 22-electromagnetic valve.Detailed Description

[0013] The following further describes the hydraulic excavator control system and method provided in the present invention in detail with reference to the accompanying drawings and specific embodiments. It should be explained that the accompanying drawings all adopt a quite simplified mode, all use imprecise proportions, and only conveniently and clearly assist the explanation of the purposes of the embodiments of the present invention. Same or similar reference numerals in the accompanying drawings represent same or similar members.Embodiment I

[0014] FIG. 1 is a flowchart of a hydraulic excavator control method according to an embodiment of the present invention. The method mainly includes the following steps: collecting a main oil circuit pressure value of the hydraulic excavator and each pilot pressure value corresponding to a current action of the hydraulic excavator; obtaining, by the controller, a required main pump power according to the main oil circuit pressure value and each pilot pressure value corresponding to the current action of the hydraulic excavator, and sending the required main pump power to an engine ECM; the controller being capable of adjusting the main pump power according to the required main pump power; the engine ECM being capable of adjusting an engine fuel injection amount according to the required main pump power, and the time for the engine ECM to start to adjust the engine oil injection being earlier than the time for the controller to start to adjust the main pump power.

[0015] The time for the engine ECM to start to adjust the engine oil injection being earlier than the time for the controller to start to adjust the main pump power can greatly reduce a loading response time of the engine, improve a working efficiency of the whole machine, avoid the problem of black smoke from idle loading, and may further reduce an idle rotation speed of the engine and reduce fuel oil consumption. In addition, the control method further has advantages of simple implementations, low costs, and high reliability.

[0016] More specifically, the time for the engine ECM to start to adjust the engine fuel injection amount is ahead of the time for the controller to start to adjust the main pump power by 0.05-0.6 second, which matches and is consistent with the hydraulic system requirements, and improves the working efficiency of the entire machine by 1-5%.Embodiment II

[0017] FIG. 2 is a hydraulic principle diagram of a hydraulic excavator control system according to an embodiment of the present invention. The system includes an engine 10, a main pump 11, a pilot pump 12, an electromagnetic proportional valve 13, a main value 14, a hydraulic pilot handle 15, a controller 16, a first pressure collection unit, and a second pressure collection unit.

[0018] The engine 10 is connected to the main pump 11 and the pilot pump 12 for providing power for the main pump 11 and the pilot pump 12.

[0019] The main valve 14 includes a traveling valve core 17, a rotation value core 18, a moving arm valve core 19, a scraper pan valve core 20, and a pan rod valve core 21. After an outlet of the main pump 11 is connected to an inlet of the main valve 14 through a pipeline, it is sequentially connected to the traveling valve core 17, the rotation value core 18, the moving arm valve core 19, the scraper pan valve core 20, and the pan rod valve core 21 for providing oil for each action valve core and constituting a main oil circuit; an oil return port of the main valve 14 is connected to an oil tank after passing through an electromagnetic valve 22.

[0020] The pilot pump 12 is connected to an inlet of the electromagnetic proportional valve 13; a path of an outlet of the electromagnetic proportional valve 13 is connected to a tilting plate adjuster control port of the main pump 11.

[0021] The hydraulic pilot handle 15 is separately connected to a pilot control oil port of each action valve core for controlling connection and disconnection of each action valve core.

[0022] The first pressure collection unit and the second pressure collection unit are respectively in communicative connection to the controller 16. The first pressure collection unit is used for collecting the main oil circuit pressure value of the hydraulic excavator; the second pressure collection unit is used for collecting the pilot control oil circuit pressure value of each action valve core; the controller 16 can obtain the required main pump power according to the main oil circuit pressure value and the pilot control oil circuit pressure value of each action valve core and adjust the power of the main pump 11 of the hydraulic excavator according to the required main pump power.

[0023] The controller 16 is communicationally connected to the engine ECM for delivering the required main pump power to the engine ECM of the hydraulic excavator.

[0024] The time for the engine ECM to start to adjust the engine fuel injection amount is ahead of the time for the controller to start to adjust the main pump power; the time difference is generally 0.05-0.6 second, which can match and be consistent with the hydraulic system requirements, and improve the working efficiency of the entire machine by 1-5%. FIG. 3 is a relation diagram between an engine fuel injection amount of a hydraulic excavator and time in the prior art. FIG. 4 is a relation diagram between an engine fuel injection amount of a hydraulic excavator and time according to an embodiment of the present invention. The relation diagram is obtained when the difference between the time for the engine ECM to start to adjust the engine oil injection and the time for the controller to start to adjust the main pump power is 0.1 second; as can be seen from comparison and analysis that as compared with the hydraulic excavator in the prior art, a hydraulic excavator provided in embodiment II of the present invention can greatly reduce a loading response time of the engine 10, so as to improve a working efficiency of the whole machine, and avoid the problem of black smoke from idle loading, and may further reduce an idle rotation speed of the engine 10 and reduce fuel oil consumption. In addition, it further has advantages of simple implementations, low costs, and high reliability.

[0025] The first pressure collection unit, the second pressure collection unit, and the engine ECM can be connected to the controller 16 through the CAN bus.

[0026] The first pressure collection unit and the second pressure collection unit are pressure sensors; as shown in FIG. 2, a pressure sensor is separately disposed on the pilot control oil circuit of the rotation value core 18, the moving arm valve core 19, the scraper pan valve core 20, and the pan rod valve core 21.

[0027] In conclusion, the hydraulic excavator control system and method provided by the embodiment of the present invention includes: collecting a main oil circuit pressure value of the hydraulic excavator; obtaining, by a controller, a required main pump power according to the oil circuit pressure value; the controller being used for adjusting, according to the required main pump power, the power of the main pump and delivering the required main pump power to an engine ECM; the time for the engine ECM to start to adjust the engine oil injection being earlier than the time for the controller to start to adjust the main pump power so as to greatly reduce a loading response time of the engine, improve a working efficiency of the whole machine, avoid the problem of black smoke from idle loading, and further reduce an idle rotation speed of the engine and reduce fuel oil consumption. In addition, the control method further has advantages of simple implementations, low costs, and high reliability.

Claims

1. A hydraulic excavator control method, comprising the following steps: collecting, by a controller (16), an oil circuit pressure signal of a hydraulic excavator, and calculating a required main pump (11) power according to the oil circuit pressure signal; sending, by the controller (16), the required main pump (11) power to an engine ECM; and first adjusting, by the engine ECM, an engine fuel injection amount according to the required main pump (11) power, and then adjusting, by the controller (16), a main pump (11) power according to the required main pump (11) power, characterized in that the time for the engine ECM to start to adjust the engine fuel injection amount is ahead of the time for the controller (16) to start to adjust the main pump (11) power by 0.05-0.6 seconds.

2. The hydraulic excavator control method according to claim 1, wherein the oil circuit pressure signal comprises a main oil circuit pressure value of the hydraulic excavator and each pilot pressure value corresponding to a current action of the hydraulic excavator.

3. A hydraulic excavator control system comprising a controller (16), an engine ECM, and an oil circuit pressure collection unit, wherein the engine ECM and the oil circuit pressure collection unit are respectively communicationally connected to the controller (16); the controller (16) is adapted to calculate, according to an oil circuit pressure signal of a hydraulic excavator collected by the oil circuit pressure collection unit, a required main pump (11) power of the hydraulic excavator, and is configured to send the required main pump (11) power to the engine ECM; and the hydraulic excavator control system is configured such that the engine ECM first adjusts an engine fuel injection amount according to the required main pump (11) power, and then the controller (16) adjusts a main pump (11) power according to the required main pump (11) power; characterized in that the time for the engine ECM to start to adjust the engine fuel injection amount is ahead of the time for the controller (16) to start to adjust the main pump (11) power by 0.05-0.6 seconds.

4. The hydraulic excavator control system according to claim 3, wherein the controller (16) is communicationally connected to the engine ECM using a CAN bus.

5. The hydraulic excavator control system according to claim 3, wherein the oil circuit pressure collection unit comprises a first pressure sensor configured to collect a main oil circuit pressure value of the hydraulic excavator and a second pressure sensor configured to collect each pilot pressure value corresponding to a current action of the hydraulic excavator.