CN111520268A - A high-pressure common rail diesel engine pre-pressing device, pressure building method and cleaning method - Google Patents

Abstract

The invention aims to provide a pre-pressurizing device, a pressure building method and a cleaning method of a high-pressure common rail diesel engine, wherein the pre-pressurizing device comprises a frequency converter, a variable frequency motor, a common rail pump, a high-pressure common rail system and a fuel tank; the frequency converter is connected with the variable frequency motor; the variable frequency motor is coaxially connected with the common rail pump; the common rail pump is communicated with a high-pressure common rail system; the common rail pump is communicated with the fuel tank through a pipeline and is used for supplying oil to the high-pressure common rail system; the high-pressure common rail system is communicated with the fuel tank through an oil return pipe; the high-pressure common rail system is provided with a detection unit for detecting the pressure in the high-pressure common rail system. The invention has compact structure, convenient transportation, long-time stable operation and convenient maintenance, can carry out the work of pre-pressurizing, cleaning, leakage inspection and the like on high-pressure common rail systems of different manufacturers and different models, can be independently placed and is convenient to arrange.

Description

A high-pressure common rail diesel engine pre-pressing device, pressure building method and cleaning method

technical field

The invention belongs to the technical field of diesel engine testing, and in particular relates to a high-pressure common rail diesel engine pre-pressing device, a pressure building method and a cleaning method.

Background technique

The high-pressure common rail system has the characteristics of flexible and adjustable fuel injection pressure, high injection pressure, flexible control of fuel injection rate, and high control accuracy, and realizes the required fuel injection advance angle, fuel injection pressure, The precise adjustment of fuel injection flow at the time of fuel injection start and end of fuel injection, as well as multiple functions such as low-speed high-pressure injection and multiple injection, provides a broader optimization space for further improving diesel engine performance and reducing emissions.

As the most important part of high pressure common rail diesel engine, the high pressure common rail system has a precise structure, the internal fuel pressure can reach up to 300MPa, the tightness and cleanliness requirements are strict, and the structure is complex. If there is a sealing problem after installation, the disassembly process is time-consuming and labor-intensive. Therefore, it is necessary to pre-press the high-pressure common rail system before installing it into the high-pressure common rail diesel engine to check the tightness.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a high pressure common rail diesel engine pre-pressing device, a pressure building method and a cleaning method, which can perform pressure building operations on the high pressure common rail system as required before installation, check the airtightness of the high pressure common rail system, and prevent installation After rework, improve work efficiency.

In order to achieve the above purpose, the specific scheme adopted in the present invention is: a high-pressure common rail diesel engine pre-pressing device, characterized in that: it includes a frequency conversion motor, a frequency conversion motor, a common rail pump, a high pressure common rail system and a fuel tank; wherein, the The frequency converter is connected with the frequency conversion motor; the frequency conversion motor is coaxially connected with the common rail pump; the common rail pump is communicated with the high-pressure common rail system; wherein, the common rail pump is communicated with the fuel tank through a pipeline, and is used for sending the high pressure The common rail system supplies oil; the high pressure common rail system is communicated with the fuel tank through an oil return pipe; wherein, the high pressure common rail system is provided with a detection unit for detecting its internal pressure.

A control valve I is arranged between the common rail pump and the high pressure common rail system.

The oil return pipe of the high-pressure common rail system is provided with a control valve II.

A pre-pressing method using the above-mentioned high-pressure common rail diesel engine pre-pressing device, characterized in that: the amount of oil supplied to the high-pressure common rail system is controlled by a variable frequency motor, so that the pressure in the high-pressure common rail system is built according to a preset pressure. The speed is increased; by detecting the pressure data in the high-pressure common rail system, when the pressure data reaches the preset pressure, stop the oil supply to achieve pre-pressurization; the high-pressure common rail system that reaches the preset pressure is subjected to pressure observation, according to the detection unit The data to judge the airtightness of the high pressure common rail system.

A cleaning method using the above-mentioned high pressure common rail diesel engine pre-pressing device, characterized in that: keeping the oil path between the variable frequency motor, the common rail pump, the high pressure common rail system and the fuel tank unobstructed, so that the variable frequency motor works at the highest rated power , Clean the high pressure common rail system through the flow of large flow of fuel.

Beneficial effects: the present invention can adjust the pressure build-up rate in the high-pressure common rail system according to the actual situation by controlling the working frequency of the variable frequency motor; at the same time, when the high-pressure common rail system maintains the pressure, it can be done by observing the data changes of the detection unit Obtain the sealing condition of the high pressure common rail system. The invention has compact structure, is easy to handle, can run stably for a long time, and is easy to maintain. At the same time, it can perform pre-pressurization, cleaning, leakage inspection and other work for different types of high-pressure common rail systems of different manufacturers, can be placed independently, and is convenient to arrange.

Description of drawings

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

1. Frequency converter, 2. Frequency conversion motor, 3. Common rail pump, 4. High pressure common rail system, 5. Fuel tank, 6. Fine filter, 7. Control valve I, 8, pressure gauge, 9. Control valve II.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

As shown in Figure 1: a high-pressure common rail diesel engine pre-pressing device, including a frequency converter 1, a frequency conversion motor 2, a common rail pump 3, a high pressure common rail system 4 and a fuel tank 5, wherein the frequency converter 1 and the frequency conversion motor 2 is connected to control the speed of the variable frequency motor 2; the variable frequency motor 2 is coaxially connected to the common rail pump 3 to drive the common rail pump 3; the frequency converter 1 is the power control device of the variable frequency motor 2, and by changing the The frequency of the inverter is controlled to control the rotational speed of the variable frequency motor, thereby controlling the rotational speed of the common rail pump 3; the inlet of the common rail pump 3 is communicated with the fine filter 6 through the fuel pipeline, and the outlet is communicated with the high-pressure common rail system 4; the common rail pump 3 The fuel is extracted from the fuel tank 5 and filtered by the fine filter 6 and then sent to the high-pressure common rail system 4 under pressure; the speed and power of the common rail pump 3 determine the fuel delivery capacity and the pressure build-up rate of the high-pressure common rail system 4 and rail pressure: one end of the fuel tank 5 is communicated with the fine filter 6 through the oil inlet pipe, and the other end is communicated with the oil return pipe of the high-pressure common rail system 4; the fuel tank 5 reserves the fuel required by the system, and recycles excess fuel; The inlet of the fine filter 6 is communicated with the fuel tank 5, and the outlet is communicated with the high-pressure pump 3; the fine filter 6 filters the particles and impurities in the fuel to ensure the quality of the fuel; the inlet of the high-pressure common rail system 4 is connected with the common rail pump 3 Connected, the outlet is communicated with the fuel tank 5 through the oil return pipe to store high-pressure fuel; the high-pressure common rail system 4 is equipped with a pressure gauge 8 for monitoring the pressure change of the high-pressure common rail system 4 and ensuring the normal operation of the high-pressure common rail system 4; The connection pipeline between the high-pressure common rail system 4 and the common rail pump 3 is equipped with a control valve I7 for controlling the entry of high-pressure fuel into the high-pressure common rail system 4; the return pipe of the high-pressure common rail system 4 and the fuel tank 5 is equipped with a control valve for controlling fuel recovery Valve II9.

The device can realize the step-by-step pressure building of the high-pressure common rail system 4, and realize the precise control of the pressure building process. The specific methods are as follows: open the control valve I7, close the control valve II9, start the inverter 1, start the inverter motor 2, drive the The rail pump 3, by adjusting the frequency of the frequency converter 1, controls the speed of the frequency conversion motor 2, and the frequency conversion motor 2 and the common rail pump 3 are coaxial, so as to accurately control the oil supply rate of the common rail pump 3 and the build-up pressure of the high pressure common rail system 4 rate. During the pressure building process, the change of rail pressure in the high-pressure common rail system 4 can be understood by observing the reading of the pressure gauge 8; the above-mentioned pressurization rate can be set by itself according to the actual situation.

The above device can perform leakage inspection on the high-pressure common rail system 4. The specific methods are as follows: open the control valve I7, close the control valve II9, start the inverter 1, start the inverter motor 2, drive the common rail pump 3, and adjust the inverter 1. When the frequency reaches the appropriate frequency, the speed of the variable frequency motor 2 reaches the required value, the variable frequency motor 2 and the common rail pump 3 are coaxial, the fuel is drawn out from the fuel tank 5 by the common rail pump 3, and passes through the fine filter 6, the common rail pump 3, and the control valve I7. After that, it is continuously injected into the high-pressure common rail system 4, observe whether there is leakage in the high-pressure common rail system 4, and always pay attention to the reading of the pressure gauge 8. When the reading of the pressure gauge 8 reaches the target requirement, close the control valve I7 and keep the pressure for a period of time. After that, check the reading of pressure gauge 8 for changes. After completing the leak check, open the control valve II9 to return the fuel to the fuel tank 5.

The above device can clean and clean the high-pressure common rail system 4. The specific methods are as follows: open the control valve I7 and the control valve II9, start the frequency converter 1, start the frequency conversion motor 2, drive the common rail pump 3, and change the frequency of the frequency converter 1. Adjust to high frequency, the frequency conversion motor 2 is at a high speed at this time, and the frequency conversion motor 2 and the common rail pump 3 are coaxial. At this time, the speed and power of the common rail pump 3 reach the maximum, and the oil supply rate reaches the maximum. The fuel is pumped out from the fuel tank 5 by the common rail pump 3, passes through the fine filter 6, the common rail pump 3, the control valve I7, the high-pressure common rail system 4, and the control valve II9, and then returns to the fuel tank 5 from the oil return pipe, and continues to press one end for a period of time. , to complete the cleaning of the high-pressure common rail system 4 and ensure the cleanliness of the interior of the high-pressure common rail system 4 .

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical scope disclosed by the present invention can easily change or replace them, all belonging to the scope of the present invention. within the protection scope of the present invention. Therefore, the protection scope of the present invention is described in accordance with the protection scope of the claims.

Claims (5)

1. A high-pressure common rail diesel engine pre-pressing device, characterized in that: comprising a frequency converter (1), a variable frequency motor (2), a common rail pump (3), a high pressure common rail system (4) and a fuel tank (5); Wherein, the frequency converter (1) is connected with the frequency conversion motor (2); Wherein, the variable frequency motor (2) is coaxially connected with the common rail pump (3); the common rail pump (3) is communicated with the high-pressure common rail system (4); Wherein, the common rail pump (3) is communicated with the fuel tank (5) through a pipeline for supplying fuel to the high pressure common rail system (4); the high pressure common rail system (4) is connected to the fuel tank (5) through an oil return pipe ) is connected; Wherein, the high-pressure common rail system (4) is provided with a detection unit for detecting its internal pressure. 2. a kind of high pressure common rail diesel engine pre-pressing device according to claim 1, is characterized in that: be provided with control valve I (7) between described common rail pump (3) and high pressure common rail system (4) . 3. A high-pressure common rail diesel engine pre-pressing device according to claim 1, characterized in that: a control valve II (9) is provided on the oil return pipe of the high-pressure common rail system (4). 4. A pre-pressing method using the high-pressure common rail diesel engine pre-pressing device as claimed in claim 1, characterized in that: by controlling the amount of oil supplied to the high-pressure common rail system (4) by the variable frequency motor (2), the high-pressure The pressure in the common rail system (4) is increased according to a preset pressure building rate; by detecting the pressure data in the high-pressure common rail system (4), when the pressure data reaches the preset pressure, the oil supply is stopped to realize pre-pressurization; The high-pressure common rail system (4) that has reached the preset pressure is subjected to pressure observation, and the airtightness of the high-pressure common rail system (4) is judged according to the data of the detection unit. 5. A cleaning method using the high-pressure common rail diesel engine pre-pressing device as claimed in claim 1, characterized in that: maintaining a frequency conversion motor (2), a common rail pump (3), a high-pressure common rail system (4) and a fuel tank The oil passage between (5) is unblocked, so that the variable frequency motor (2) works at the highest rated power, and the high-pressure common rail system (4) is cleaned by the flow of fuel with a large flow.

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