A constant pressure stabilizing device for diesel engine preheating system

Abstract

The invention discloses a constant pressure stabilizing device for a diesel engine preheating system, which belongs to the technical field of diesel engine preheating, and comprises a connecting valve integrated into an integral structure, a fuel tank for containing diesel, a low-pressure pump for extracting and pressurizing diesel from the fuel tank, a diesel fine filter for filtering diesel, a solenoid valve for controlling the oil inlet and oil return of a flame jet preheater, and a flame jet preheater in which diesel is burned; diesel flows into the connecting valve through the diesel fine filter, and the connecting valve reduces the pressure and flow of diesel and then flows into the flame jet preheater through the solenoid valve for combustion; excess diesel flowing into the flame jet preheater flows back into the connecting valve through the solenoid valve and the oil return pipe and then returns to the fuel tank. The connecting valve designed in the invention reduces the pressure and limits the flow of a relatively large diesel pressure by designing a damping hole in the oil inlet line, and adds a one-way valve on the oil return line to stabilize the oil pressure and ensure the normal flow direction of the diesel, thereby achieving the purpose of a constant oil supply system pressure.

Description

Technical Field

[0001] The invention relates to the technical field of diesel engine preheating, in particular to a constant pressure stabilizing device of a diesel engine preheating system, which is applied to a diesel supply pipeline of a flame injection type preheater system. Background Art

[0002] The flame preheating system is an important system for cold starting of diesel engines. Diesel engines are compression ignition engines without spark plug ignition. When the diesel engine is cold started, the diesel is easy to condense due to the low initial speed of the diesel engine crankshaft. Therefore, during cold start, the gas entering the cylinder is difficult to rise to the auto-ignition temperature, and a preheating device is needed to increase the intake temperature. At present, the main preheating devices for diesel engines are electric wire preheaters and flame injection preheaters.

[0003] The existing diesel engine flame preheating system does not have a constant pressure stabilization device, which has the following disadvantages:

[0004] First, the existing diesel engine preheating system pipelines are mostly used in inline pump diesel engines and electronically controlled single pump diesel engines. The low-pressure diesel pipelines of these two types of diesel engines have low pressure, and the pressure and flow are controlled by the working state of the low-pressure pump. There is no return oil pipeline in the preheating system pipeline, and the oil inlet pipe of the flame jet preheater is directly connected to the low-pressure diesel pipeline. The pressure and flow are controlled by the working state of the low-pressure pump. During cold start, the starter motor drives the diesel engine and indirectly provides power to the low-pressure pump. At this time, the speed of the low-pressure pump fluctuates greatly, resulting in large changes in the pressure and flow of the low-pressure pump diesel, affecting the normal operation of the flame preheating plug;

[0005] Second, on high-pressure common rail diesel engines, due to the difference in the fuel supply system, the pressure in the low-pressure diesel pipeline is relatively high. If it is directly connected to the oil inlet pipeline of the flame jet preheater, the preheater cannot withstand it, which can easily cause damage to the flame jet preheater. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a constant pressure stabilizing device for a diesel engine preheating system. A connecting valve is designed with a damping hole in the oil inlet line to reduce the pressure and limit the flow of a larger diesel pressure, and a one-way valve is added to the oil return line to stabilize the oil pressure and ensure the normal flow direction of the diesel, thereby achieving the purpose of a constant oil supply system pressure. The device is applied to the diesel supply pipeline of a flame injection preheater system.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A constant pressure stabilizing device for a diesel engine preheating system comprises a connecting valve integrated into an integral structure, a fuel tank containing diesel, a low-pressure pump for extracting and pressurizing diesel from the fuel tank, a diesel fine filter for filtering diesel, a solenoid valve for controlling the oil inlet and oil return of a flame jet preheater, and a flame jet preheater in which diesel is burned; the low-pressure pump extracts diesel from the fuel tank and pressurizes it, the pressurized diesel flows into the connecting valve through the diesel fine filter, the connecting valve reduces the pressure and flow of the diesel, and then flows into the flame jet preheater through the solenoid valve for combustion; the excess diesel flowing into the flame jet preheater flows back into the connecting valve through the solenoid valve and an oil return pipe, and then returns to the fuel tank.

[0009] A further improvement of the technical solution of the present invention is that the connecting valve includes a valve body provided with 5 threaded connection holes, a damping hole for reducing pressure and flow, a sealing bolt for sealing the one-way valve channel, and a one-way valve with a steel ball spring structure; the damping hole and the one-way valve work together to achieve the function of stabilizing pressure and limiting flow.

[0010] A further improvement of the technical solution of the present invention is that: the five threaded connection holes include hole one, hole two, hole three, hole four and a sealing bolt hole; the diesel enters from hole one, passes through the damping hole in the pipeline, and flows into the solenoid valve from hole two; then the purpose of pressure reduction and current limiting is achieved, the return oil enters from hole three, passes through the one-way valve, and flows out from hole four into the total return oil pipeline.

[0011] A further improvement of the technical solution of the present invention is that the damping hole is a full external thread stud with a small hole processed in the center.

[0012] A further improvement of the technical solution of the present invention is that: the outer diameter of the one-way valve is provided with an external thread, which can be screwed into the sealing bolt hole in the valve body, and the diesel can only pass through in one direction and cannot flow in the reverse direction.

[0013] A further improvement of the technical solution of the present invention is that the connecting valve can reduce the pressure of the low-pressure diesel pipeline from 7-10 bar to 2-3 bar before the diesel enters the solenoid valve.

[0014] A further improvement of the technical solution of the present invention is that the opening pressure of the one-way valve is 2-3 bar.

[0015] A further improvement of the technical solution of the present invention is that the low-pressure pump draws diesel from the fuel tank and pressurizes it to 7-10 bar.

[0016] A further improvement of the technical solution of the present invention is that the outer shell valve body of the connecting valve is an aluminum alloy rectangular parallelepiped structure.

[0017] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is:

[0018] 1. The present invention reduces the pressure and limits the flow of the larger diesel oil pressure by designing a damping hole in the oil inlet line, and adds a one-way valve in the oil return line to stabilize the oil pressure and ensure the normal flow direction of the diesel oil, thereby achieving the purpose of constant oil supply system pressure.

[0019] 2. The present invention integrates the oil inlet and return pipelines of the preheating system into a connecting valve, uses a simple mechanical structure, and achieves the functions of pressure reduction, current limiting and voltage stabilization without adopting electronic control.

[0020] 3. The present invention integrates two oil inlet pressure reducing and oil return pressure maintaining devices into one, which is convenient for layout and installation. It is one of the key components of the diesel engine preheating diesel supply system, and directly solves the problem that most of the current flame preheating systems do not have oil return devices and pressure stabilizing devices. It is not only suitable for high diesel pressure applications, but also can play a role in voltage stabilization and current limiting, which is beneficial to the normal operation of the flame preheating system.

[0021] 4. The connecting valve in the present invention is highly integrated, occupies less space in the diesel engine, is light in weight, does not use an electronic system, and achieves the purpose of stabilizing pressure and limiting current. It is applied to the diesel supply pipeline of the flame injection preheater system, and can solve the problem of stabilizing diesel pressure and balancing diesel flow in the flame preheating diesel pipeline of the high-pressure common rail diesel engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a connection diagram of a constant pressure stabilizing device for a preheating system of the present invention;

[0023] Figure 2 It is a schematic diagram of the internal structure of the connecting valve of the present invention;

[0024] Figure 3 It is a schematic diagram of the installation of the present invention in a diesel engine.

[0025] Among them, 1. connecting valve, 1-1. valve body, 1-2. hole two, 1-3. damping hole, 1-4. hole one, 1-5. sealing bolt, 1-6. one-way valve, 1-7. hole four, 1-8. hole three, 2. fuel tank, 3. low-pressure pump, 4. diesel fine filter, 5. solenoid valve, 6. flame jet preheater, 7. connecting valve to preheating solenoid valve oil inlet, 8. preheating plug return oil to connecting valve, 9. return oil to injection pump main return, 10. preheating solenoid valve oil inlet, 11. to flame preheating plug oil pipe, 12. preheating plug return oil pipe. DETAILED DESCRIPTION

[0026] The present invention is aimed at the shortcomings of the prior art and has developed a constant pressure stabilizing device for a diesel engine preheating system. An oil inlet pipeline and an oil return pipeline are arranged inside a connecting valve. The two pipelines operate independently without interfering with each other. The present invention can reduce the oil inlet pressure and flow in the high-pressure common rail diesel engine preheating system and stabilize the oil pressure in the oil supply pipeline to ensure the normal flow of diesel. The present invention is used to solve the problems of stabilizing the diesel pressure and balancing the diesel flow in the flame preheating diesel pipeline of a high-pressure common rail diesel engine.

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0028] like Figure 1 As shown, a constant pressure stabilizing device for a diesel engine preheating system comprises a connecting valve 1 integrated into an integral structure, a fuel tank 2 for containing diesel, a low-pressure pump 3 for extracting and pressurizing diesel from the fuel tank 2, a diesel fine filter 4 for filtering diesel, a solenoid valve 5 for controlling the oil inlet and oil return of a flame-jet preheater 6, and a flame-jet preheater 6 in which diesel is burned; the low-pressure pump 3 extracts and pressurizes diesel from the fuel tank 2, and the pressurized diesel flows into the connecting valve 1 through the diesel fine filter 4, and the connecting valve 1 reduces the pressure and reduces the flow rate of the diesel, and then flows into the flame-jet preheater 6 through the solenoid valve 5 for combustion; the excess diesel flowing into the flame-jet preheater 6 flows back into the fuel tank 2 through the solenoid valve 5 via the oil return pipe and then flows back into the connecting valve 1.

[0029] like Figure 2 As shown, the connecting valve 1 includes a valve body 1-1 provided with 5 threaded connection holes, a damping hole 1-3 for reducing pressure and flow, a sealing bolt 1-5 for sealing the channel of the one-way valve 1-6, and a one-way valve 1-6 with a steel ball spring structure; the damping hole 1-3 and the one-way valve 1-6 work together to achieve the function of stabilizing pressure and limiting flow.

[0030] The five threaded connection holes include hole one 1-4, hole two 1-2, hole three 1-8, hole four 1-7 and a sealing bolt hole. Diesel enters from hole one 1-4, passes through the damping hole 1-3 in the pipeline to achieve the purpose of pressure reduction and current limiting, and flows into the solenoid valve 5 from hole two 1-2; return oil enters from hole three 1-8, passes through the one-way valve 1-6, and flows out from hole four 1-7 into the total return oil pipeline.

[0031] The damping holes 1-3 are full external thread studs with a small hole processed in the center to play a damping role.

[0032] The outer diameter of the one-way valve 1-6 is provided with an external thread, which can be screwed into the sealing bolt hole in the valve body 1-1. Diesel can only pass through in one direction and cannot flow in the reverse direction.

[0033] Before the diesel enters the solenoid valve 5, the connecting valve 1 can reduce the pressure of the low-pressure diesel pipeline from 7-10 bar to 2-3 bar.

[0034] The opening pressure of the one-way valve 1-6 is 2-3 bar.

[0035] The low-pressure pump 3 draws diesel from the fuel tank 2 and pressurizes it to 7-10 bar.

[0036] The outer shell valve body of the connecting valve 1 is an aluminum alloy rectangular parallelepiped structure.

[0037] Working principle:

[0038] 1. Functional principle description

[0039] The diesel engine preheating system is mainly used to preheat the diesel engine when it is started in a low-temperature environment. Its main components are a flame preheating plug, a control system, and a diesel supply system. The flame preheating plug is controlled by the control system to heat the internal resistance wire. The diesel supply system is controlled by the control system to supply diesel with appropriate pressure and flow at the right time, which is ignited by the flame preheating plug to achieve the purpose of heating the diesel engine intake air, thereby facilitating the diesel engine to start in a low-temperature environment.

[0040] When the diesel engine is started at low temperature, the low-pressure pump 3 starts to work, extracts diesel from the fuel tank 2 and pressurizes it to 7-10 bar and transports it to the diesel fine filter 4 for filtration. After being filtered, the diesel enters the connecting valve 1 through the hole 1-4, and is transported to the solenoid valve 5 through the hole 2 1-2 after the pressure is reduced and the flow is reduced through the damping hole 1-3. After the solenoid valve 5 is opened, the diesel enters the flame injection preheater 6 for combustion to heat the intake air. The excess diesel enters the hole 3 1-8 through the return oil pipe, and the diesel returns to the fuel tank 2 through the hole 4 1-7 after passing through the one-way valve 1-6.

[0041] The main functions of the connecting valve 1 are two:

[0042] First, before the diesel enters the solenoid valve 5 , the pressure and flow of the low-pressure diesel pipeline are reduced, and the pressure of the low-pressure diesel pipeline is reduced from 7-10 bar to 2-3 bar, so as to achieve the purpose of protecting the mechanical structure of the solenoid valve 5 and the flame injection preheater 6 .

[0043] Second, ensure that the diesel in the preheating system can return to the main oil return pipe, but the diesel in the main oil return pipe cannot enter the preheating system, ensure the normal flow direction of the diesel and prevent the return oil from causing oil leakage from the flame preheating plug.

[0044] 2. Description of structural principle

[0045] like Figure 2As shown, the valve body of the connecting valve 1 is an aluminum alloy rectangular parallelepiped structure with 5 threaded connection holes. The damping hole 1-3 is a full external thread stud with a small hole processed in the center to play a damping role. The one-way valve 1-6 is a steel ball spring structure with an external thread on the outer diameter, which can be screwed into the valve body. Diesel can only pass through in one direction and cannot flow in the reverse direction. The sealing screw plug 1-5 seals the one-way valve 1-6 channel. Diesel enters from hole one 1-4, passes through the damping hole 1-3 in the pipeline to achieve the purpose of pressure reduction and flow limitation, and the return oil enters from hole three 1-8, passes through the return oil one-way valve 1-6 opened at 2-3 bar, and flows out from hole four 1-7 into the total return oil pipeline, achieving the purpose of stabilizing the diesel pressure and preventing the diesel in the fuel tank 2 from flowing back to the preheating pipeline.

[0046] like Figure 3 As shown, the schematic diagram of the installation position of the connecting valve 1 in the diesel engine, the connecting valve to the preheating solenoid valve oil inlet 7, the preheating plug return oil to the connecting valve 8, the return oil to the injection pump total return 9, the preheating solenoid valve oil inlet 10, to the flame preheating plug oil pipe 11, the preheating plug return oil pipe 12.

[0047] In summary, the connecting valve designed in the present invention is highly integrated. A damping hole is designed in the oil inlet line to reduce the pressure and limit the flow of the larger diesel oil. A one-way valve is added in the oil return line to stabilize the oil pressure and ensure the normal flow direction of the diesel oil, thereby achieving the purpose of constant fuel supply system pressure. The connecting valve occupies less space in the diesel engine, is light in weight, and does not use an electronic system, thereby achieving the purpose of stabilizing the pressure and limiting the flow. When used in the diesel supply pipeline of the flame injection preheater system, it can solve the problems of stabilizing the diesel oil pressure and balancing the diesel oil flow in the flame preheating diesel pipeline of the high-pressure common rail diesel engine.

Claims

1. A constant pressure stabilizing device for a diesel engine preheating system, characterized in that: The invention comprises a connecting valve (1) integrated into an integral structure, a fuel tank (2) for containing diesel, a low-pressure pump (3) for extracting and pressurizing diesel from the fuel tank (2), a diesel fine filter (4) for filtering diesel, a solenoid valve (5) for controlling the oil inlet and oil return of a flame jet preheater (6), and a flame jet preheater (6) in which diesel is burned; the low-pressure pump (3) extracts and pressurizes diesel from the fuel tank (2), the pressurized diesel passes through the diesel fine filter (4) and flows into the connecting valve (1), the connecting valve (1) reduces the pressure and flow rate of the diesel and then flows into the flame jet preheater (6) through the solenoid valve (5) for combustion; the excess diesel that flows into the flame jet preheater (6) passes through the solenoid valve (5) and the oil return pipe and flows back into the connecting valve (1) and then returns to the fuel tank (2); The connecting valve (1) comprises a valve body (1-1) provided with five threaded connection holes, a damping hole (1-3) for reducing pressure and flow, a sealing bolt (1-5) for sealing a channel of a one-way valve (1-6), and a one-way valve (1-6) with a steel ball spring structure; the damping hole (1-3) and the one-way valve (1-6) work together to achieve the function of stabilizing pressure and limiting flow; The five threaded connection holes include hole one (1-4), hole two (1-2), hole three (1-8), hole four (1-7) and a sealing bolt hole; diesel enters from hole one (1-4), passes through the damping hole (1-3) in the pipeline, and flows into the solenoid valve (5) from hole two (1-2); return oil enters from hole three (1-8), passes through the one-way valve (1-6), and flows out from hole four (1-7) into the total return oil pipeline; The damping hole (1-3) is a full external thread stud with a small hole processed in the center.

2. A constant pressure stabilizing device for a diesel engine preheating system according to claim 1, characterized in that: The outer diameter of the one-way valve (1-6) is provided with an external thread which can be screwed into the sealing bolt hole in the valve body (1-1), so that diesel can only pass through in one direction and cannot flow in the reverse direction.

3. A constant pressure stabilizing device for a diesel engine preheating system according to claim 1, characterized in that: The connecting valve (1) can reduce the pressure of the low-pressure diesel pipeline from 7-10 bar to 2-3 bar before the diesel enters the solenoid valve (5).

4. A constant pressure stabilizing device for a diesel engine preheating system according to claim 1, characterized in that: The opening pressure of the non-return valve (1-6) is 2-3 bar.

5. A constant pressure stabilizing device for a diesel engine preheating system according to claim 1, characterized in that: The low-pressure pump (3) draws diesel from the fuel tank (2) and pressurizes it to 7-10 bar.

6. A constant pressure stabilizing device for a diesel engine preheating system according to claim 1, characterized in that: The outer shell valve body of the connecting valve (1) is an aluminum alloy rectangular parallelepiped structure.

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