CN112761835B

CN112761835B - Automatically controlled components of a whole that can function independently monoblock pump

Info

Publication number: CN112761835B
Application number: CN202110046896.7A
Authority: CN
Inventors: 王字满; 杨旭超; 武治平; 孙柏刚; 吴晗
Original assignee: Beijing Institute of Technology BIT
Current assignee: Beijing Institute of Technology BIT
Priority date: 2021-01-14
Filing date: 2021-01-14
Publication date: 2022-04-15
Anticipated expiration: 2041-01-14
Also published as: CN112761835A

Abstract

The invention discloses an electronic control split monoblock pump, which comprises a pump body and a valve body, wherein the valve body is fixed on the side surface of the pump body through a bolt, a high-pressure oil duct in the pump body is in a three-way tubular shape, and outlets of the three oil ducts are respectively communicated with a pump nozzle oil duct, a plunger piston cavity and the high-pressure oil duct in the valve body; the low-pressure oil duct in the pump body is communicated with the low-pressure oil duct in the valve body. The invention can reduce the processing difficulty and ensure the precision.

Description

Automatically controlled components of a whole that can function independently monoblock pump

Technical Field

The invention relates to the technical field of engines, in particular to an electronic control split unit pump.

Background

The diesel engine is the heat engine with the highest thermal efficiency and is most widely applied in the fields of industry, agriculture, transportation and national defense. Therefore, the development of the diesel engine industry has important significance for social and economic construction and national defense construction. At present, diesel engines are being developed for higher speeds, lighter weights, and higher strengths.

The fuel supply system is one of the most important and delicate components of a diesel engine, known as the "heart" of the diesel engine. Technological advances in diesel engines have largely been attributed to the development of fuel delivery systems. For fuel delivery systems, high injection pressures and high injection rates are required for the duration of the injection. The electric control monoblock pump and the high-pressure common rail technology are electric injection technologies which are widely applied at present, and both the electric control monoblock pump and the high-pressure common rail technology can realize high-pressure injection and independent cylinder control. In view of the existing machining technology level and oil products in China, the structural reliability and durability of the high-pressure common rail system are difficult to solve. The electronic control unit pump fuel oil system becomes one of ideal choices of a high-power diesel engine due to the advantages of high injection pressure, small change to the existing engine, good oil product adaptability, excellent system reliability and the like. Nowadays, an electronic unit pump fuel system is widely applied to diesel engines in various fields such as ships, non-road vehicles, commercial vehicles, locomotives and the like. For example, a high-power diesel engine for Yuchai 3240 ships, 28/33D series high-reliability marine diesel engines of MAN company, heavy diesel engines for Yuchai YC6L-40 vehicles, diesel engines for east red-LR 6A3LU off-road vehicles, diesel engines for the AC transmission diesel locomotive, i.e. HXn5 diesel locomotive, which has the largest power in China, and the like.

At present, domestic common electric control unit pumps comprise Boshi electric control unit pumps and Delfu electric control unit pumps.

The bosch electric control unit pump is structurally shown in fig. 1 and 2, a transverse oil passage positioned above a pump body is an electromagnetic valve control oil passage, an annular oil cavity A, B, F and an oil passage D, G are low-pressure oil passages, and a plunger cavity C and an oil passage E are high-pressure oil passages. After the electromagnetic valve is electrified, the armature and the cone valve are driven to move rightwards, so that a channel between high-pressure and low-pressure oil ways is cut off, and high pressure is established; the structure is characterized in that the control oil duct and the main oil duct are in an accurate vertical relation. The control valve assembly of the electric control monoblock pump is a key part for establishing high pressure by the pump, so that the requirements on the planeness, the verticality, the roughness and the like of a plane E (a cushion block mounting plane), a plane F (a control valve hole surface) and a plane G (a control valve limiting block positioning surface) shown in figure 10 are extremely high. The bosch electronic control unit pump directly processes the planes on the pump body, the processing difficulty is high, and the precision is difficult to ensure.

The delfu electrically controlled unit pump operates on the same principle as bosch, but has a very different structural form, as shown in fig. 3 and 4. The delfu electric control unit pump integrates an electromagnetic valve into the pump body, and controls the connection and disconnection of the high-pressure oil circuit and the low-pressure oil circuit by controlling the valve body to move up and down through the electromagnetic valve. The valve body of the Delfu electric control monoblock pump and the oil duct of the pump body are sealed by the large plane at the lower end of the valve body, so that the plane has high processing precision requirement and high parallelism requirement, is not easy to guarantee and is easy to cause oil leakage.

In summary, the bosch electric control unit pump has the following defects:

1. the control oil duct and the main oil duct are in an accurate vertical relation, and the machining precision requirement is high.

2. The high-pressure oil hole above the plunger cavity is offset, so that the processing is inconvenient.

3. The coil is transversely arranged, the occupied space is large, and the arrangement on an engine is difficult.

4. The horizontal coil is fixed on the pump body by the long bolt, so that a bolt through hole needs to be processed on the pump body, and the volume and the mass of the pump are increased.

The drawbacks of the delfu electric control unit pump are as follows:

1. the requirement on the machining precision of the large sealing plane at the lower end of the valve body is high, the requirement on the parallelism is high, and the requirement is not easy to guarantee.

2. The matching surface between the pump nozzle and the damping valve has high precision requirement and is not easy to process.

Disclosure of Invention

In view of this, the invention provides an electronic control split unit pump, which can reduce the processing difficulty and ensure the precision.

The technical scheme adopted by the invention is as follows:

an electronic control split monoblock pump comprises a pump body and a valve body, wherein the valve body is fixed on the side face of the pump body through a bolt, a high-pressure oil duct in the pump body is in a three-way tubular shape, and outlets of the three oil ducts are respectively communicated with a pump nozzle oil duct, a plunger piston cavity and the high-pressure oil duct in the valve body; the low-pressure oil duct in the pump body is communicated with the low-pressure oil duct in the valve body.

Further, the high-pressure oil passage in the pump body is divided into an oil passage I, an oil passage II and an oil passage III; the oil duct I is obliquely arranged, one end of the oil duct I is communicated with the oil duct of the pump nozzle, and the other end of the oil duct I is communicated with the middle part of the oil duct III; the oil duct III is obliquely arranged, one end of the oil duct III is communicated with the high-pressure oil duct in the valve body, and the other end of the oil duct III is communicated with the oil duct II; the oil duct II is vertically arranged, one end of the oil duct II is communicated with the plunger cavity, and the other end of the oil duct II is communicated with the oil duct III; and the included angle between the oil duct I and the oil duct III is smaller than the included angle between the oil duct III and the high-pressure oil duct in the valve body.

Further, the included angle between the oil passage I and the vertical direction is 22 degrees, the included angle between the oil passage III and the vertical direction is 55 degrees, and the included angle between the high-pressure oil passage in the valve body and the vertical direction is 75 degrees.

Furthermore, the high-pressure oil duct in the pump body and the high-pressure oil duct in the valve body are sealed by metal gaskets on the contact plane of the pump body and the valve body; the low-pressure oil duct in the pump body and the low-pressure oil duct in the valve body are sealed by a rubber sealing ring on the contact plane of the pump body and the valve body.

Furthermore, the upper surface and the lower surface of the metal pad are conical surfaces.

Furthermore, the pump body is provided with an inclined plane, and the inclined plane and the valve body mounting surface on the pump body are arranged on two sides respectively.

Has the advantages that:

1. the invention adopts the split design of the pump body and the valve body, and the pump body and the valve body are connected by bolts. Therefore, the valve body and the pump body can be separately processed, the processing difficulty is greatly reduced, and the precision is ensured. Because the bottom limiting block of the control valve is tightly pressed on the valve body by the limiting block nut, the installation position of the limiting block nut is not required to be reserved by adopting the split design of the valve body and the pump body, the parts in the valve body can be installed firstly, and then the valve body is installed on the pump body, so that the transverse width of the electric control monoblock pump can be greatly reduced, compared with the Bosch electric control monoblock pump, the transverse width of the electric control monoblock pump is reduced by nearly 20mm, and meanwhile, the quality of the whole pump can be reduced.

Secondly, the bosch electronic control unit pump is provided with a through hole on the pump body, and the coil is fixed on the pump body through the long bolt and the cover plate, so that two matching surfaces as shown in fig. 11 need to be processed. The precision requirement of the matching surface is high, and the processing is inconvenient. According to the invention, the threaded hole is directly machined on the pump body, only one matching surface needs to be machined, and the machining difficulty is reduced.

2. The high-pressure oil duct in the pump body is in a three-way tubular shape, and the oil ducts I, II and III can be arranged in a mode of avoiding secondary start-up of the oil sprayer caused by outflow of residual high-pressure oil.

3. According to the invention, different oil ducts on the same plane are sealed in different modes, the low-pressure oil duct hole is sealed by the sealing ring, and the high-pressure oil duct hole is sealed by the metal sealing gasket, so that the required precision of the matching surface is reduced, the processing difficulty is reduced, and a higher sealing effect can be obtained.

4. Because the pump body and the valve body are connected by the bolts instead of through holes, the pump body can be processed into an inclined plane without a cover plate, and the quality of the whole pump can be further reduced.

5. When the plane sealing gasket without taper is compressed, the contact area is large, so that uneven stress is easily caused, and the sealing is not tight. The metal gasket adopted by the high-pressure oil duct has taper, when the pump body and the valve body are tightly pressed, the conical surface of the sealing gasket and the valve body of the pump body are in line contact to generate extremely small deformation, the pressure-bearing area is reduced, the circumference of the sealing gasket hole is uniformly stressed, and the sealing reliability is improved.

Drawings

FIG. 1 is a block diagram of a Boshi electric control unit pump;

FIG. 2 is a bosch electronic unit pump fuel injection system;

FIG. 3 is a schematic view of a Delford electronically controlled monoblock pump configuration;

FIG. 4 is a fuel injection system for a delfu electronically controlled monoblock pump;

FIG. 5 is a cross-sectional view of a monoblock pump structure of the present invention;

FIG. 6(a) is a schematic view of fuel flow during oil fill;

FIG. 6(b) is a block diagram of the control valve assembly;

FIG. 7 is a schematic view of the split design of the pump body and the valve body according to the present invention;

FIG. 8(a) is a schematic view of a high pressure gallery seal;

FIG. 8(b) is a schematic view of a low pressure gallery seal;

FIG. 9 is a view showing the structure of a metal gasket;

FIG. 10 is a schematic view of a machined surface;

FIG. 11 is a schematic view of the mating surface of a Bosch electric control unit pump;

FIG. 12 is a schematic view of the oil gallery hole and seal at the mating surface;

FIG. 13 is a schematic view of the pump body and valve body oil passage arrangement;

the damping valve comprises a spring seat 1, a plunger spring 2, a plunger 5, a pump body 8, a sealing gasket 9, a pump nozzle 10, a damping valve assembly 11, a protective layer 12, a coil 14, a coil compression nut 14, a sealing ring I, a sealing ring 16, an armature 17, a cushion block 18, an upper spring limiting block 19, a control valve screw 19, a control valve spring 20, a lower spring limiting block 21, a control valve 22, a valve body 23, a control valve bottom limiting block 24, a limiting block nut 25, a sealing ring II, a rubber sealing ring 27, a metal gasket 28, a pump nozzle oil channel 29, an oil channel I31, an oil channel II 32, an oil channel III 33, a bend I and a bend II 34.

Detailed Description

The invention is described in detail below by way of example with reference to the accompanying drawings.

The invention provides an electronic control split unit pump, which comprises a pump body 8 and a valve body 23, wherein the valve body 23 is fixed on the side surface of the pump body 8 through a bolt, a high-pressure oil duct in the pump body 8 is in a three-way pipe shape, and outlets of the three oil ducts are respectively communicated with a pump nozzle oil duct 29, a plunger cavity and a high-pressure oil duct D in the valve body 23; the low pressure oil passage in the pump body 8 is communicated with the low pressure oil passage in the valve body 23.

As shown in fig. 13, the high-pressure oil passage in the pump body 8 is divided into an oil passage i 30, an oil passage ii 31, and an oil passage iii 32; the oil passage I30 is obliquely arranged, one end of the oil passage I is communicated with the pump nozzle oil passage 29, and the other end of the oil passage I is communicated with the middle of the oil passage III 32; the oil duct III 32 is obliquely arranged, one end of the oil duct III is communicated with the high-pressure oil duct D in the valve body 23, the oil duct III and the high-pressure oil duct D are bent II 34, and the other end of the oil duct III is communicated with the oil duct II 31; the oil duct II 31 is vertically arranged, one end of the oil duct II is communicated with the plunger cavity, and the other end of the oil duct II is communicated with the oil duct III 32; the included angle between the oil passage I30 and the oil passage III 32 is smaller than the included angle between the oil passage III 32 and the high-pressure oil passage in the valve body 23. An included angle a between the oil passage I30 and the vertical direction is 22 degrees, an included angle b between the oil passage III 32 and the vertical direction is 55 degrees, and an included angle c between the high-pressure oil passage D in the valve body 23 and the vertical direction is 75 degrees.

Spring holder 1 and plunger 5 bottom cooperation, plunger spring 2 installs between pump body 8 and spring holder 1.

The pump nozzle 10 is connected with the pump body 8 by screw thread, and a sealing gasket 9 is arranged between the pump nozzle and the pump body. The damper valve assembly 11 is mounted within the pump nozzle 10. A protective layer 12 is arranged outside the pump nozzle 10.

The valve body 23 is pressed against the pump body 8 by four bolts. The pump body 8 is provided with an inclined plane, the quality of the whole pump can be further reduced, and the inclined plane and the valve body mounting surface on the pump body 8 are arranged on two sides respectively. The stop block nut 25 presses the control valve bottom stop block 24 against the valve body 23. The control valve 22 cooperates with a control valve bore in the valve body 23. The spacer 17 is mounted on the valve body 23. The pretightening force of the control valve spring 20 presses the upper spring limit block 18 against the lower surface of the cushion block 17, and presses the lower spring limit block 21 matched with the control valve 22. The armature 16 is connected to the control valve 22 by a control valve screw 19. The coil compression nut 14 is in threaded connection with the valve body 23 to press the coil 13 against the spacer 17. And a sealing ring I15 is arranged between the coil 13 and the valve body 23. The size of the air gap between the coil 13 and the armature 16 can be changed by changing the thickness of the cushion block 17.

The high-pressure oil passage C in the pump body 8 and the high-pressure oil passage D in the valve body 23 are sealed by a metal gasket 28 on the contact plane of the pump body 8 and the valve body 23; the upper and lower surfaces of the metal pad 28 are tapered surfaces. The low-pressure oil passage in the pump body 8 and the low-pressure oil passage A, B in the valve body 23 are sealed by a rubber seal 27 at the contact plane of the pump body 8 and the valve body 23. And a sealing ring II 26 is arranged in the oil passages at the bottoms of the control valve 22 and the valve body 23.

The working principle of the monoblock pump is as follows:

oil filling process: the oil supply cam pushes the single pump tappet body assembly to overcome the spring force of the plunger piston to move upwards. When the cam passes through, the plunger 5 moves downwards under the action of the spring force of the plunger, the pressure in the plunger cavity of the unit pump is lower than the oil pressure of the low-pressure oil way, and at the moment, low-pressure fuel oil sequentially enters the annular oil cavity of the control valve 22 in fig. 6(a) from the pump body oil way A, B on the pump body in fig. 5 and enters the plunger cavity through the valve body 23 oil way D and the pump body oil way C, so that the oil filling process is completed. The pump body oil passage A, B is a low pressure oil passage, and the pump body oil passage C is a high pressure oil passage.

And (3) a bypass process: when the plunger 5 moves upwards, the fuel in the plunger cavity is compressed to cause the oil pressure in the plunger cavity to rise, at the moment, if the electromagnet is in a power-off state, the control valve core does not cut off the low-pressure oil way and the high-pressure oil way, and the compressed fuel returns to the low-pressure oil way from the oil way of the pump body in the figure 6(a) along the reverse direction of the oil filling process.

High pressure generating process, in the process of pressing oil by the plunger 5, the ECU gives a control pulse at a specific moment, the electromagnet is electrified through a driving circuit, thus the armature 16 in figure 6(b) drives the control valve 22 to move upwards, the control valve 22 and the oil passage at the bottom of the valve body 23 are closed, the high-pressure oil passage and the low-pressure oil passage are disconnected, and a closed volume is formed in the plunger cavity. As the plunger 5 in fig. 5 moves upward, the fuel in the plunger chamber is compressed to generate high-pressure fuel, and the high-pressure fuel is delivered to the front end of the injector through the pump body oil passage C and the pump nozzle oil passage 29.

Unloading process: after the control pulse is finished, the electromagnet is powered off, and the high-pressure fuel oil in the unit pump quickly flows back to the low-pressure oil way through the oil passage C, D in fig. 5.

When oil injection is finished, the electromagnetic valve is powered off, and oil in the plunger cavity returns to the low-pressure oil way through the oil passages C and D, the control valve oil cavity and the oil passage B. In the invention, because the included angle between the oil passage I30 and the oil passage III 32 is smaller, and the included angle between the inclined oil passage D and the oil passage III 32 is larger, the resistance of oil flowing through the bend I33 is larger than the resistance of oil flowing through the bend II 34, so that high-pressure oil remained in the plunger cavity can smoothly flow back to a low-pressure oil passage when oil injection is finished, and secondary start of the oil injector caused by outflow of the remained high-pressure oil from the oil passage I30 is avoided.

In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An electronic control split monoblock pump is characterized by comprising a pump body and a valve body, wherein the valve body is fixed on the side face of the pump body through a bolt, a high-pressure oil duct in the pump body is in a three-way tubular shape, and outlets of the three oil ducts are respectively communicated with a pump nozzle oil duct, a plunger piston cavity and the high-pressure oil duct in the valve body; the low-pressure oil duct in the pump body is communicated with the low-pressure oil duct in the valve body; the oil duct is divided into an oil duct I, an oil duct II and an oil duct III; the oil duct I is obliquely arranged, one end of the oil duct I is communicated with the oil duct of the pump nozzle, and the other end of the oil duct I is communicated with the middle part of the oil duct III; the oil duct III is obliquely arranged, one end of the oil duct III is communicated with the high-pressure oil duct in the valve body, and the other end of the oil duct III is communicated with the oil duct II; the oil duct II is vertically arranged, one end of the oil duct II is communicated with the plunger cavity, and the other end of the oil duct II is communicated with the oil duct III; and the included angle between the oil duct I and the oil duct III is smaller than the included angle between the oil duct III and the high-pressure oil duct in the valve body.

2. An electronic control split unit pump as claimed in claim 1, wherein the included angle between the oil passage I and the vertical direction is 22 degrees, the included angle between the oil passage III and the vertical direction is 55 degrees, and the included angle between the high-pressure oil passage in the valve body and the vertical direction is 75 degrees.

3. An electric control split unit pump according to claim 1, wherein the high-pressure oil passage in the pump body and the high-pressure oil passage in the valve body are sealed by a metal gasket on a contact plane of the pump body and the valve body; the low-pressure oil duct in the pump body and the low-pressure oil duct in the valve body are sealed by a rubber sealing ring on the contact plane of the pump body and the valve body.

4. An electrically controlled split unit pump according to claim 3, wherein the upper and lower surfaces of the metal pad are tapered surfaces.

5. An electrically controlled split unit pump according to claim 1, wherein the pump body is formed with an inclined surface, and the inclined surface is separated from the valve body mounting surface on the pump body on both sides.