CN103114624A - Load-sensitive operation system of loading machine - Google Patents

Abstract

The invention relates to a loader, in particular to a load-sensitive control system of the loader. An oil outlet of a traveling plunger pump is connected to a first pipeline, and the end of the first pipeline is connected in parallel with an accumulator, two Two-way electromagnetic reversing valve, the other end of the two-position two-way electromagnetic reversing valve is connected to the oil inlet port of the pilot control valve, and the control oil port of the pilot control valve is connected to the control port of the load-sensing multi-way valve through a pipeline. The oil outlet of the steering valve is connected to the fuel tank, and the feedback oil port of the load-sensitive multi-way valve is connected to the feedback oil port of the working plunger pump. The charge pump inside the piston pump provides a pilot pump instead of the traditional pilot pump for oil supply; the working plunger pump adjusts the pressure-flow output according to the change of the load through the feedback oil port of the load-sensing multi-way valve, effectively utilizing Engine power, control hydraulic oil temperature rise, realize energy saving and environmental protection.

Description

Load Sensing Control System of Loader

technical field

The present invention relates to loaders, and more particularly to load-sensitive steering systems for loaders.

Background technique

At present, major domestic manufacturers generally use mechanical switch valves for the selection of loader control systems. This structure will produce defects such as large control force, empty travel, and poor fretting of the working device. These defects will cause the driver's labor Intensity increases, causing driver fatigue to work and causing potential safety hazards.

In foreign countries, especially in developed countries such as Europe and the United States, pilot control is often used to control loaders, and the pilot oil source is supplied by an independent pilot pump. By manipulating the pilot valve, the pilot oil is used to push the main valve core to realize the action of the arm and bucket of the loader. This kind of manipulation method is very light, reduces the labor intensity of the driver and is easy to realize accurate positioning of the boom and bucket, but This structure also naturally has inevitable defects: due to the use of an independent pilot pump oil supply technical solution, on the one hand, it causes an increase in design cost, on the other hand, it also leads to a complex structure and increases the failure points of the whole machine.

Contents of the invention

The object of the present invention is to overcome the deficiencies in the prior art, and provide a load-sensitive control system of a loader with a simple structure, ingenious and reasonable structure, the system is simple in structure, high in reliability, strong in control comfort, energy-saving and environment-friendly.

According to the technical solution provided by the present invention: a load-sensing control system for a loader, characterized in that: an oil outlet of the traveling plunger pump is connected to a first pipeline, and the end of the first pipeline is connected in parallel with an accumulator, Two-position two-way electromagnetic reversing valve, the other end of the two-position two-way electromagnetic reversing valve is connected to the oil inlet of the pilot control valve, and the control oil port of the pilot control valve is connected to the control port of the load-sensing multi-way valve through a pipeline , the oil outlet of the pilot control valve is connected to the oil tank, the oil outlet of the load-sensing multi-way valve is connected to the oil tank through the oil return filter element, and the oil cylinder of the working device is connected to the load-sensing multi-way valve; the feedback oil port of the load-sensing multi-way valve Connect to the feedback port of the working piston pump.

As a further improvement of the present invention, a check valve is installed on the first pipeline.

Compared with the prior art, the present invention has the advantages that: the control oil of the pilot control valve in the load sensitive control system of the loader of the present invention is provided by the charging oil pump inside the traveling plunger pump, which reduces a pilot pump and replaces the traditional The pilot pump supplies oil; the working plunger pump adjusts the pressure-flow output according to the load change through the feedback oil port of the load-sensitive multi-way valve, effectively uses the engine power, controls the temperature rise of the hydraulic oil, and realizes energy saving and environmental protection.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

Detailed ways

The present invention will be further described below in conjunction with specific drawings and embodiments.

As shown in Figure 1, it includes a fuel tank 1, a traveling plunger pump 2, a one-way valve 3, an accumulator 4, a two-position two-way electromagnetic reversing valve 5, a pilot control valve 6, a load-sensitive multi-way valve 7, and a working device Oil cylinder 8, working plunger pump 9, oil return filter element 10, first pipeline 11, etc.

As shown in Figure 1, the present invention is a load sensitive control system of a loader, an oil outlet of the traveling plunger pump 2 is connected to the first pipeline 11, and a check valve 3 is installed on the first pipeline 11 , the end of the first pipeline 11 is connected in parallel with the accumulator 4, the two-position two-way electromagnetic reversing valve 5, the other end of the two-position two-way electromagnetic reversing valve 5 is connected to the oil inlet of the pilot control valve 6, and the pilot control valve 6 (The pilot control valve 6 is composed of the control valve of the boom cylinder and the control valve of the bucket cylinder) The control oil port is connected to the load-sensing multi-way valve 7 through the pipeline (the load-sensing multi-way valve 7 is composed of the control valve of the boom cylinder and the control valve of the bucket cylinder. Composed of) the control port, the function of this control port is mainly to introduce the pilot oil through the first-arriving control valve 6 into the load-sensing multi-way valve 7 to control the spool in the load-sensing multi-way valve 7 to be in different working positions, The working oil that enters the load-sensing multi-way valve 7 through the working plunger pump 9 selectively enters the large and small chambers of the working device cylinder according to the position of the spool in the load-sensing multi-way valve 7 to meet the requirements For the needs of external work, the oil outlet of the pilot control valve 6 is connected to the oil tank 1 , the oil outlet of the load-sensing multi-way valve 7 is connected to the oil tank 1 through the oil return filter element 10, and the oil cylinder 8 of the working device is connected to the load-sensing multi-way valve 7;

The feedback oil port of the load sensitive multi-way valve 7 is connected to the feedback oil port of the working plunger pump 9, and the feedback oil port of the working plunger pump 9 changes according to the magnitude of the external load.

The charging pump inside the traveling plunger pump 2 of the present invention provides a stable, low-pressure and low-flow pressure oil source for the pilot control valve 6 .

As shown in Figure 1, the present invention sets an oil circuit between the traveling plunger pump 2 and the pilot control valve 6, and the charge oil pump inside the travel plunger pump 2 supplies pressure oil to the pilot control valve 6, and the load sensitive multi-way valve 7 The feedback port of the pump is connected to the working plunger pump 9, and the swash plate of the working plunger pump 9 is adjusted according to the change of the external load to achieve the pressure-flow change output of the working plunger pump 9. In other words, the engine The change provides the corresponding power, so that the power of the engine can be effectively used, the waste of power caused by the quantitative system can be avoided, the temperature rise of the hydraulic oil can be effectively controlled, and the purpose of energy saving and environmental protection can be achieved. The present invention also aims at the special situation that the engine is turned off and the traveling plunger pump 2 is not working. The pressure oil from the accumulator 4 is connected to the pilot control valve 6 through the two-position two-way electromagnetic reversing valve 5 to adjust the whereabouts of the boom cylinder 8. height, so as to ensure the safe operation of the loader.

Claims (2)

1. the load-sensitive control system of a loader, it is characterized in that: an oil-out of walking plunger displacement pump (2) is connected the first pipeline (11), described the first pipeline (11) end accumulator (4) in parallel, 2/2-way solenoid operated directional valve (5), the oil-in of described 2/2-way solenoid operated directional valve (5) other end access pilot control valve (6), the control port of pilot control valve (6) connects the control mouth of load sensing multi-way valve (7) by pipeline, the oil-out of pilot control valve (6) connects fuel tank (1), the oil-out of load sensing multi-way valve (7) is by oil return filter core (10) access fuel tank (1), equipment oil cylinder (8) is connected with load sensing multi-way valve (7), the feedback hydraulic fluid port of the feedback hydraulic fluid port connection work plunger displacement pump (9) of described load sensing multi-way valve (7).

2. the load-sensitive control system of loader as claimed in claim 1, is characterized in that: one way valve (3) is installed on described the first pipeline (11).

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