CN105952562B - A composite high-pressure common rail pump for single-cylinder diesel engines - Google Patents

Abstract

A composite high-pressure common rail pump for a single-cylinder diesel engine includes a single-cylinder common rail accumulator and a single-cylinder common rail pump. The single-cylinder common rail accumulator and the single-cylinder common rail pump are sealed and fixedly connected into one body. With the integration of the oil pump and the common rail, the installation method of the oil pump and the diesel engine remains unchanged. It can be directly installed and used on the existing diesel engine. There is no need to process the installation holes of the diesel engine body separately. At the same time, the common rail connection between the common rail and the oil pump is eliminated. The rail tube can also minimize the size of the high-pressure common rail pump of a single-cylinder diesel engine. Using a high-speed solenoid valve to replace the proportional solenoid valve in the existing technology can reduce the cost by 50 to 60 yuan/unit; it can directly control the existing diesel engine. By carrying out common rail electronic injection upgrade and transformation, the single-cylinder diesel engine can reach the National IV emission standard by using the present invention.

Description

A compound high-pressure common rail pump for single-cylinder diesel engines

Technical field

The invention relates to a combustion system of a single-cylinder diesel engine, and in particular to a common rail pump assembly in a high-pressure common rail system of a single-cylinder diesel engine.

Background technique

For a long time, single-cylinder diesel engines have been widely used in backup power supplies, agricultural machinery, pumping machinery, engineering machinery, marine and other industries due to their low price and portability. In recent years, due to the backward emission levels of single-cylinder diesel engines, the national environmental protection emission requirements have With the increase, the domestic market share is gradually compressed; according to data from the China Internal Combustion Engine Industry Association, China's single-cylinder diesel engine production was around 4 million units in 2015, with a peak of around 8 million units, and the number of single-cylinder diesel engines was around 20 million units; on the one hand , the overall emission level of the single-cylinder diesel engine industry is backward, causing it to emit a large amount of harmful gases into the atmosphere every year; on the other hand, the backward emission level has gradually made it excluded by the market, and there is an urgent need for technological upgrading.

China will fully implement non-road China III emission standards by the end of 2016, and is expected to implement non-road China IV emission standards in 2018. Single-cylinder diesel engines are within the limits of this regulation.

After the emission regulations are upgraded, the common rail system of single-cylinder diesel engines will become the fundamental solution for the upgrade of emission technology of single-cylinder diesel engines; in the disclosed technical solution for the common rail system of single-cylinder diesel engines, the mechanical part includes common rail pumps and common rail pipes. , fuel injector three major components, these three major components are connected by high-pressure oil pipes. Although this alternative technical solution can realize high-pressure common rail electronic injection of a single-cylinder diesel engine, the cost of the common rail system of the existing single-cylinder diesel engine is too high and the volume is too large to be directly applied on the existing single-cylinder diesel engine.

The "high-pressure oil pump assembly for integrated diesel engine high-pressure common rail fuel injection system" is disclosed in the invention patent 201610025226.6. It still continues the conventional technical idea, dividing the mechanical part of the system into three major components, and using high-pressure oil pipes to connect each other; In this invention, the tappet guidance in the high-pressure oil pump assembly relies on the diesel engine, that is, the body of the diesel engine must be redesigned, and special guide holes need to be left on the body. The body of the diesel engine needs to be redesigned and processed, and the entire processing production line must be redesigned. The investment is huge; at the same time, the oil volume control method of this high-pressure oil pump assembly adopts proportional solenoid valve oil metering control, and the price of this solenoid valve is relatively high.

The utility model patent ZL201120052744. It cannot be directly applied to diesel engines, nor can it be quoted. In this utility model, the plunger sleeve, the high-pressure original component, adopts a concave end face structure design, which has extremely poor craftsmanship. It not only increases the technical difficulty of processing and assembly, increases the cost, but cannot be combined with It is used in conjunction with the body of an existing single-cylinder diesel engine and has a very poor substitute for the fuel injection pump of an existing single-cylinder diesel engine. Current single-cylinder diesel engine manufacturers do not recognize it, let alone accept it.

Contents of the invention:

The purpose of the present invention is to provide a composite high-pressure common rail pump for a single-cylinder diesel engine. It is designed according to the characteristics of the existing single-cylinder diesel engine and has the characteristics of strong adaptability, compact structure, low cost, and deep technical potential.

The technical solution adopted by the present invention:

A compound high-pressure common rail pump for a single-cylinder diesel engine, which is characterized by: including a single-cylinder common rail accumulator and a single-cylinder common rail pump, and the oil inlet end of the single-cylinder common rail accumulator and the single-cylinder common rail pump. After the oil outlet ends are butted, they are sealed and fixedly connected into one body.

Further, the single-cylinder common rail accumulator includes a common rail body, a constant pressure oil outlet, a pressure accumulation chamber, a constant pressure oil inlet, a pressure sensor and a one-way oil outlet chamber. The pressure accumulation chamber is arranged on the common rail. In the body, the constant pressure oil outlet channel, constant pressure oil inlet channel, pressure sensor and one-way oil outlet chamber are all connected with the pressure accumulation chamber. Among them, the constant pressure oil outlet channel, constant pressure oil inlet channel and one-way oil outlet chamber Coaxially arranged; the single-cylinder common rail pump includes a pump body, a tappet, a plunger spring lower seat, a plunger spring, a plunger, a plunger guide sleeve, a radial sealing ring, a high-pressure chamber, an oil channel distributor, Steel balls, oil inlet valve spring, oil outlet valve seat, oil outlet valve core, oil outlet valve spring, oil outlet valve spring seat and high-speed solenoid valve. There is an oil outlet hole in the center of the oil outlet valve seat. The lower end face is equipped with a steel ball cavity, and an upper oil inlet passage is provided on the side of the oil outlet valve seat; an oil inlet blind hole with an upper end opening is provided in the center of the oil passage distributor, and an oil inlet blind hole is provided on the side of the oil passage distributor. The lower oil inlet passage is provided with a horizontal oil inlet passage at the lower end of the oil inlet passage on the lower side of the oil passage distributor. A vertical oil passage is provided between the upper end face and the lower end face of the oil passage distributor. There is an oil inlet pit on the lower end face, and the vertical oil channel is connected with the oil inlet pit;

Further, the pump body includes a butt hole, a threaded connection hole, a matching hole, a transition hole, a lower guide hole, a solenoid valve mounting hole, and a steering oil inlet passage. Coaxially distributed from top to bottom; the plunger guide sleeve is screwed in the threaded connection hole of the pump body, the oil channel distributor and the oil outlet valve seat are set in the butt hole, and the oil outlet valve seat is located on the oil channel distributor Above, the steel ball is set between the oil outlet valve seat and the oil channel distributor. The oil outlet valve core is set in the oil outlet hole of the oil outlet valve seat. The oil inlet valve spring is set between the lower end of the oil outlet valve core and the steel ball. The lower end of the oil valve spring is set on the upper section of the oil delivery valve core, the oil delivery valve spring seat is set in the inner hole of the upper end of the oil delivery valve spring, and the lower seat of the plunger spring is set on the plunger and is located at the lower end of the plunger. The plug is set in the guide hole of the plunger guide sleeve, the plunger spring is set between the plunger guide sleeve and the lower seat of the plunger spring, and the lift cylinder is set in the lower guide hole of the pump body, and is pushed up by the limit pin. The lifting stroke of the cylinder is limited, and the lower end of the plunger is in contact with the tappet.

Further, a radial sealing ring is provided between the plunger guide sleeve and the matching hole of the pump body.

Furthermore, two radial sealing rings are spaced between the plunger guide sleeve and the matching hole of the pump body.

Further, the butt structure of the oil inlet end of the single-cylinder common rail accumulator and the oil outlet end of the single-cylinder common rail pump is such that the oil inlet end of the single-cylinder common rail accumulator is sleeved in the butt hole of the pump body.

Furthermore, the oil inlet end of the single-cylinder common rail accumulator and the oil outlet end of the single-cylinder common rail pump have a sealed butt structure. The oil inlet end of the single-cylinder common rail accumulator is set in the butt hole of the pump body. The joint between the common rail body and the pump body is provided with a sealing structure.

Furthermore, a sealing structure is provided at the joint between the common rail body and the pump body, and an end sealing ring is provided between the joint surfaces between the common rail body and the pump body.

Furthermore, the sealing structure provided at the joint between the common rail body and the pump body is as follows: a radial sealing ring is provided between the outer circle of the oil inlet end of the single-cylinder common rail accumulator and the butt hole of the pump body.

Its working process is as follows:

Oil suction process: When the camshaft is in the descending section, the plunger spring drives the lift cylinder, the lower seat of the plunger spring, and the plunger to move downward simultaneously. At this time, the volume of the high-pressure chamber increases to form negative pressure, and the oil inlet recess at the lower end of the oil channel distributor The oil pit is connected to the cavity of the steel ball through the vertical oil channel. At this time, the high-speed solenoid valve is energized and open. The fuel enters the docking hole of the pump body through the steering oil inlet channel and the high-speed solenoid valve, and then passes through the upper part of the oil outlet valve seat. The side oil inlet channel and the lower side oil inlet channel of the oil channel distributor enter the horizontal oil inlet channel and the oil inlet blind hole to push the steel ball away, and then enter the steel ball chamber to suck into the high-pressure chamber from the vertical oil channel;

Oil pressure process: When the camshaft is in the rising stage, the tappet pushes the lower end of the plunger to move upward, and the plunger spring is compressed under the action of the lower seat of the plunger spring. At this time, the volume of the high-pressure chamber shrinks, the oil pressure increases, and the high-pressure chamber The fuel sucked and stored in the cavity enters the steel ball chamber from the oil inlet pit and the vertical oil channel. The steel balls are sealingly pressed against the opening of the oil inlet blind hole under the action of pressurized fuel, closing the oil inlet blind hole, and pressurizing the fuel. Push the oil outlet valve core upward, so that the oil outlet valve core is in the open state, and the pressure fuel enters the pressure accumulation chamber through the constant pressure oil inlet passage of the single-cylinder common rail accumulator. The pressure sensor detects the oil in the pressure accumulation chamber. The pressure is measured and controlled. When the oil pressure reaches a predetermined value, the oil injection device is input from the constant pressure oil outlet to complete the oil pressure process.

The invention integrates the oil pump and the common rail. The installation method of the oil pump and the diesel engine remains unchanged. It can be directly installed and used on the existing diesel engine. It does not require additional processing of the installation hole system of the diesel engine body. At the same time, the connection between the common rail and the diesel engine is eliminated. The common rail pipe of the oil pump can also minimize the volume of the high-pressure common rail pump of the single-cylinder diesel engine. By using a high-speed solenoid valve to replace the proportional solenoid valve in the existing technology, the cost can be reduced by 10% to 15%; in the present invention, The lift guide and positioning structure of the tappet are all set in the hole in the pump body, and there are no special design requirements for the diesel engine body; it can directly upgrade and transform existing diesel engines with common rail electronic injection, and carry out National III-level upgrades on existing single-cylinder diesel engines. Standard environmentally friendly emission is a very economically feasible technical solution. The use of the present invention can enable a single-cylinder diesel engine to reach the National IV emission standard.

In the present invention, the high-pressure element plunger guide sleeve and the pump body are separated and designed into a multi-stage cylindrical structure. This structure is circumferentially homogeneous and symmetrical, which is beneficial to the high-precision processing of the hole in the plunger sleeve in the later stage; compared with the prior art The special-shaped structure requires counterweight processing, which greatly reduces the process difficulty; moving parts such as tappets, plunger springs, etc. are designed with internal structures to avoid the possibility of collision, interference, and impact with diesel engine parts. The invention has compact structure, low cost, good craftsmanship and stable performance, and is suitable for a high-pressure common rail system oil supply pump assembly used in single-cylinder diesel engines.

Picture description:

Figure 1 is a schematic structural diagram of the present invention;

Figure 2 is a schematic structural diagram of a single-cylinder common rail accumulator in the present invention;

Figure 3 is a schematic structural diagram of a single-cylinder common rail pump;

Figure 4 is a schematic structural diagram of the pump body;

Figure 5 is a schematic structural diagram of the oil outlet valve seat;

Figure 6 is a schematic structural diagram of the oil channel distributor;

In the picture: 1-single-cylinder common rail accumulator; 2-single-cylinder common rail pump; 3-end sealing ring; 11-common rail body; 12-constant pressure oil outlet; 13-pressure storage chamber; 14- Constant pressure oil inlet channel; 15-pressure sensor; 16-one-way oil outlet chamber; 17-oil inlet end; 21-pump body; 22-tap cylinder; 23-plunger spring lower seat; 24-plunger spring; 25-Plunger; 26-Plunger guide sleeve; 27-Radial sealing ring; 28-High pressure chamber; 29-Oil distributor; 30-Steel ball; 31-Oil inlet valve spring; 32-Oil outlet valve seat; 33 -Oil delivery valve core; 34-Oil delivery valve spring; 35-Oil delivery valve spring seat; 36-High-speed solenoid valve; 37-Limit pin; 38-Limit circlip; 211-Butt hole; 212-Threaded connection hole ; 213-fitting hole; 214-transition hole; 215-lower guide hole; 216-solenoid valve mounting hole; 217-steering oil inlet; 291-oil inlet blind hole; 292-lower oil inlet; 293-horizontal inlet Oil passage; 294-vertical oil passage; 295-oil inlet pit; 321-oil outlet hole; 322-steel ball cavity; 323-upper oil inlet passage.

Detailed ways:

The specific embodiments of the present invention will be described below in conjunction with the accompanying drawings:

Embodiment 1: A compound high-pressure common rail pump for a single-cylinder diesel engine, as shown in Figures 1 to 6. It consists of a single-cylinder common rail accumulator 1 and a single-cylinder common rail pump 2. The single-cylinder common rail accumulator The energy generator 1 and the single-cylinder common rail pump 2 are fixedly connected into one body through fasteners and end seals 3; the single-cylinder common rail accumulator 1 includes a common rail body 11, a constant pressure oil outlet 12, and a pressure storage capacity. Chamber 13, constant pressure oil inlet passage 14, pressure sensor 15 and one-way oil outlet chamber 16, pressure accumulation chamber 13 is set in the common rail body 11, constant pressure oil outlet passage 12, constant pressure oil inlet passage 14, pressure sensor 15 and the one-way oil outlet chamber 16 are both connected with the pressure accumulation chamber 13, in which the constant pressure oil outlet passage 12, the constant pressure oil inlet passage 14 and the one-way oil outlet chamber 16 are coaxially arranged; the single cylinder common rail Pump 2 includes a pump body 21, a lift cylinder 22, a plunger spring lower seat 23, a plunger spring 24, a plunger 25, a plunger guide sleeve 26, a radial sealing ring 27, a high-pressure chamber 28, an oil channel distributor 29, Steel ball 30, oil inlet valve spring 31, oil outlet valve seat 32, oil outlet valve core 33, oil outlet valve spring 34, oil outlet valve spring seat 35 and high speed solenoid valve 36. There is an outlet valve in the center of the oil outlet valve seat 32. The oil hole 321 is provided with a steel ball cavity 322 on the lower end surface of the oil outlet valve seat 32, and an upper oil inlet passage 323 is provided on the side of the oil outlet valve seat 32; an upper opening is provided in the center of the oil passage distributor 29 The oil inlet blind hole 291 is provided with a lower oil inlet channel 292 on the side of the oil channel distributor 29, and a horizontal oil inlet channel 293 is provided at the lower end of the oil inlet channel 292 of the oil channel distributor 29. A vertical oil channel 294 is provided between the upper end surface and the lower end surface of 29, and an oil inlet oil pit 295 is provided on the lower end surface of the oil channel distributor 29. The vertical oil channel 294 is connected with the oil inlet oil pit 295; The pump body 21 includes a butt hole 211, a threaded connection hole 212, a mating hole 213, a transition hole 214, a lower guide hole 215, a solenoid valve mounting hole 216 and a steering oil inlet channel 217. , transition hole 214 and lower guide hole 215 are coaxially distributed from top to bottom; the plunger guide sleeve 26 is screwed in the threaded connection hole 212 of the pump body 21, and the oil channel distributor 29 and the oil outlet valve seat 32 are arranged in the butt joint hole 211, and the oil outlet valve seat 32 is located above the oil channel distributor 29. The steel ball 30 is set between the oil outlet valve seat 32 and the oil channel distributor 29. The oil outlet valve core 33 is set on the oil outlet valve seat 32. In the oil outlet hole 321, the oil inlet valve spring 31 is arranged between the lower end of the oil outlet valve core 33 and the steel ball 30. The lower end of the oil outlet valve spring 34 is sleeved on the upper section of the oil outlet valve core 33. The oil outlet valve spring seat 35 is sleeved on the oil outlet hole 321. In the inner hole of the upper end of the oil delivery valve spring 34, the plunger spring lower seat 23 is sleeved on the plunger 25 and is located at the lower end of the plunger 25. The plunger 25 is sleeved in the guide hole of the plunger guide sleeve 26. The plunger spring 24 is provided between the plunger guide sleeve 26 and the plunger spring lower seat 23. The tappet 22 is set in the lower guide hole 215 of the pump body 21, and the lifting stroke of the tappet 22 is limited by the limit pin 37. position, the limit pin 37 is limited by the limit circlip 38, and the lower end of the plunger 25 contacts the tappet 22; two radial seals are provided between the plunger guide sleeve 26 and the matching hole 213 of the pump body 21 Circle 27.

There are many implementations of the present invention, and all solutions that use the same principle as the present invention and other functional substitutions fall within the protection scope of the present invention.

Claims (7)

1. A compound high-pressure common rail pump for a single-cylinder diesel engine, which is characterized by: including a single-cylinder common rail accumulator (1) and a single-cylinder common rail pump (2). The single-cylinder common rail accumulator (1) The oil inlet end and the oil outlet end of the single-cylinder common rail pump (2) are butted and sealed and fixedly connected together. The single-cylinder common rail accumulator (1) includes a common rail body (11), a constant pressure oil outlet channel (12), pressure accumulation chamber (13), constant pressure oil inlet channel (14), pressure sensor (15) and one-way oil outlet chamber (16). The pressure accumulation chamber (13) is set on the common rail body (14). 11), the constant pressure oil outlet channel (12), the constant pressure oil inlet channel (14), the pressure sensor (15) and the one-way oil outlet chamber (16) are all connected with the pressure accumulation chamber (13), where, The constant pressure oil outlet (12), the constant pressure oil inlet (14) and the one-way oil outlet chamber (16) are coaxially arranged. The single-cylinder common rail pump (2) includes a pump body (21) and a tappet. (22), plunger spring lower seat (23), plunger spring (24), plunger (25), plunger guide sleeve (26), radial sealing ring (27), high pressure chamber (28), oil passage Distributor (29), steel ball (30), oil inlet valve spring (31), oil outlet valve seat (32), oil outlet valve core (33), oil outlet valve spring (34), oil outlet valve spring seat (35 ) and high-speed solenoid valve (36), an oil outlet hole (321) is provided in the center of the oil outlet valve seat (32), and a steel ball cavity (322) is provided on the lower end surface of the oil outlet valve seat (32). An upper oil inlet passage (323) is provided on the side of the oil valve seat (32); an oil inlet blind hole (291) with an upper end opening is provided in the center of the oil passage distributor (29). There is a lower oil inlet passage (292) on the side of the A vertical oil passage (294) is provided between the upper end face and the lower end face. An oil inlet pit (295) is provided on the lower end face of the oil passage distributor (29). The vertical oil passage (294) and the oil inlet pit are (295) are connected; the pump body (21) includes a docking hole (211), a threaded connection hole (212), a matching hole (213), a transition hole (214), a lower guide hole (215), and a solenoid valve mounting hole. (216) and the steering oil inlet (217), the butt hole (211), the threaded connection hole (212), the matching hole (213), the transition hole (214), and the lower guide hole (215) are coaxial from top to bottom. Distribution; the plunger guide sleeve (26) is screwed into the threaded connection hole (212) of the pump body (21), the oil channel distributor (29) and the oil outlet valve seat (32) are set in the docking hole (211), And the oil outlet valve seat (32) is located above the oil channel distributor (29), the steel ball (30) is set between the oil outlet valve seat (32) and the oil channel distributor (29), the oil outlet valve core (33) It is set in the oil outlet hole (321) of the oil outlet valve seat (32). The oil inlet valve spring (31) is set between the lower end of the oil outlet valve core (33) and the steel ball (30). The oil outlet valve spring (34) The lower end of the oil outlet valve core (33) is sleeved on the upper section of the oil outlet valve core (33), the oil outlet valve spring seat (35) is sleeved on the inner hole of the upper end of the oil outlet valve spring (34), and the plunger spring lower seat (23) is sleeved on the plunger. (25) and is located at the lower end of the plunger (25). The plunger (25) is set in the guide hole of the plunger guide sleeve (26). The plunger spring (24) is set between the plunger guide sleeve (26) and the plunger. Between the lower seats (23) of the plug spring, the tappet body (22) is set in the lower guide hole (215) of the pump body (21), and the lifting stroke of the tappet body (22) is controlled by the limit pin (37). To limit the position, the lower end of the plunger (25) contacts the tappet (22). 2. The compound high-pressure common rail pump for single-cylinder diesel engines according to claim 1, characterized in that: a radial seal is provided between the plunger guide sleeve (26) and the matching hole (213) of the pump body (21). Circle (27). 3. The compound high-pressure common rail pump for single-cylinder diesel engines according to claim 2, characterized in that: the fitting holes (213) of the plunger guide sleeve (26) and the pump body (21) are spaced axially. There are two radial sealing rings (27). 4. The compound high-pressure common rail pump for single-cylinder diesel engines according to claim 1, characterized in that: the oil inlet end (17) of the single-cylinder common rail accumulator (1) and the oil inlet end (17) of the single-cylinder common rail pump (2) The oil outlet docking structure is: the oil inlet end (17) of the single-cylinder common rail accumulator (1) is set in the docking hole (211) of the pump body (21). 5. The compound high-pressure common rail pump for single-cylinder diesel engines according to claim 4, characterized in that: the oil inlet end (17) of the single-cylinder common rail accumulator (1) and the oil inlet end (17) of the single-cylinder common rail pump (2) The oil outlet sealing docking structure is that the oil inlet end (17) of the single-cylinder common rail accumulator (1) is set in the docking hole (211) of the pump body (21), and between the common rail body 11 and the pump body 21 The joint is provided with a sealing structure. 6. The compound high-pressure common rail pump for single-cylinder diesel engines according to claim 5, characterized in that: the sealing structure at the joint between the common rail body (11) and the pump body (21) is, An end sealing ring (3) is provided between the butt surfaces of the pump body (21). 7. The compound high-pressure common rail pump for a single-cylinder diesel engine according to claim 5, characterized in that: a sealing structure is provided at the joint between the common rail body (11) and the pump body (21). A radial seal is provided between the outer circle of the oil inlet end (17) of the accumulator (1) and the butt hole (211) of the pump body (21).