CN105952562A - Composite high-pressure common rail pump for single cylinder diesel engine - Google Patents

Abstract

A composite high-pressure common rail pump for a single cylinder diesel engine comprises a single cylinder common rail energy accumulator and a single cylinder common rail pump body which are fixedly connected into a whole in a sealed manner. An oil pump and a common rail are integrated, the installing manner of the oil pump and the diesel engine is not changed, the oil pump can be directly installed and used on an existing diesel engine, and an installing hole system of an engine body of the diesel engine does not need to be additionally machined. Meanwhile, a common rail pipe connecting the common rail with the oil pump is eliminated, the size of the high-pressure common rail pump for the single cylinder diesel engine can be reduced to the maximum degree, a proportional electromagnetic valve in the prior art is replaced with a high-speed electromagnetic valve, and the cost can be reduced to 50-60 yuan/piece. Common rail electronic injection improving and transforming can be directly conducted on the existing diesel engine, and the single cylinder diesel engine can reach the national fourth-stage emission standard through the composite high-pressure common rail pump.

Description

A composite high pressure common rail pump for single cylinder diesel engine

technical field

The invention relates to a combustion system of a single-cylinder diesel engine, in particular to a common-rail pump assembly of 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 various industries such as backup power supply, agricultural machinery, pumping machinery, construction machinery, and marine because of their low price and portability. increase, the domestic market share is gradually compressed; according to the data of the China Internal Combustion Engine Industry Association, the output of single-cylinder diesel engines in my country in 2015 was about 4 million units, the peak value was about 8 million units, and the number of single-cylinder diesel engines was about 20 million units; on the one hand 1. 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;

China will fully implement non-road National III emission standards by the end of 2016, and it is expected that non-road National IV emission standards will be implemented in 2018, and 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 upgrading the emission technology of single-cylinder diesel engines; 1. The three major components of the fuel injector are connected by high-pressure oil pipes. Although this alternative technical solution can realize the high-pressure common-rail electric injection of single-cylinder diesel engines, the cost of the existing common-rail system for single-cylinder diesel engines is too high and the volume is too large to be directly applied to existing single-cylinder diesel engines.

In the invention patent 201610025226.6, the "high-pressure oil pump assembly for integrated diesel engine high-pressure common rail fuel injection system" is disclosed, which still continues the conventional technical thinking, and divides the mechanical part of the system into three major parts, which are connected by high-pressure oil pipes; In this invention, the guide of the tappet body in the high-pressure oil pump assembly depends 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 line must be redesigned. The investment is very large; at the same time, the oil volume control method of this high-pressure oil pump assembly adopts the proportional electromagnetic valve oil inlet metering control, and the price of this electromagnetic valve is relatively high.

In the utility model patent ZL201120052744.X, a "common rail high-pressure pump with integrated pump and rail" is disclosed. The oil pump is used in a multi-cylinder diesel engine fuel supply system; the drive of the oil pump is performed by its own camshaft, and the oil pump is huge. Diesel engines cannot be directly applied or quoted. In this utility model, the high-voltage original plunger sleeve adopts a concave end face structure design, which is extremely poor in workmanship, which not only increases the technical difficulty of processing and assembly, but also increases the cost. The body of the existing single-cylinder diesel engine is used in conjunction with it, and the substitution of the fuel injection pump of the existing single-cylinder diesel engine is extremely poor. The current single-cylinder diesel engine manufacturers do not recognize it, let alone accept it.

Invention content:

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

The technical scheme that the present invention takes:

A composite high-pressure common rail pump for a single-cylinder diesel engine, characterized in that it includes a single-cylinder common-rail accumulator and a single-cylinder common-rail pump, the oil inlet end of the single-cylinder common-rail accumulator and the single-cylinder common-rail pump The oil outlet ends are sealed and fixedly connected into one body after butt joint.

Further, the single-cylinder common rail accumulator includes a common rail body, a constant pressure oil outlet, a pressure storage chamber, a constant pressure oil inlet, a pressure sensor and a one-way oil outlet chamber, and the pressure storage chamber is arranged on the common rail In the body, the constant pressure oil outlet, constant pressure oil inlet, pressure sensor and one-way oil outlet chamber are all connected to the pressure storage chamber, among which, the constant pressure oil outlet, constant pressure oil inlet and one-way oil outlet chamber Coaxial setting; the single-cylinder common rail pump includes a pump body, a tappet body, a plunger spring seat, a plunger spring, a plunger, a plunger guide sleeve, a radial seal ring, a high pressure chamber, an oil passage distributor, Steel ball, 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, oil outlet hole is arranged in the center of oil outlet valve seat, oil outlet valve seat The lower end surface of the steel ball is provided with a steel ball chamber, and the upper side 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 side oil inlet passage is provided with a horizontal oil inlet passage at the lower end of the lower side oil inlet passage of the oil passage distributor, and a vertical oil passage is provided between the upper end surface and the lower end surface of the oil passage distributor. The lower end surface is provided with an oil inlet concave oil pit, and the vertical oil passage is connected with the oil inlet concave oil pit;

Further, the pump body includes a docking hole, a threaded connection hole, a matching hole, a transition hole, a lower guide hole, a solenoid valve installation hole and a steering oil inlet, and the butt joint hole, a threaded connection hole, a matching hole, a transition hole, and a lower guide hole Distributed coaxially from top to bottom; the plunger guide sleeve is screwed into the threaded connection hole of the pump body, the oil channel distributor and the oil outlet valve seat are arranged in the butt joint hole, and the oil outlet valve seat is located at the end of 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, and the outlet 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, 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 arranged between the plunger guide sleeve and the lower seat of the plunger spring, the tappet body 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 arranged at intervals between the plunger guide sleeve and the matching hole of the pump body.

Further, the oil inlet end of the single-cylinder common rail accumulator is connected with the oil outlet end of the single-cylinder common rail pump, and the oil inlet end of the single-cylinder common rail accumulator is sleeved in the docking 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 are sealed butt joint structure. The oil inlet end of the single-cylinder common rail accumulator is set in the docking hole of the pump body. A sealing structure is provided at the joint 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 that an end face sealing ring is provided between the joint surfaces of 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 that 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 joint 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 tappet body and the plunger spring lower seat, and the plunger goes down synchronously. At this time, the volume of the high-pressure chamber increases to form a negative pressure. The oil pit is connected to the cavity of the steel ball through the vertical oil passage. At this time, the high-speed solenoid valve is in the open state, and the fuel enters the butt hole of the pump body through the steering oil inlet passage and the high-speed solenoid valve, and then passes through the upper part of the oil outlet valve seat. The side oil inlet passage and the lower oil inlet passage of the oil passage distributor enter the horizontal oil inlet passage and the oil inlet blind hole to push away the steel ball, and then enter the steel ball chamber to suck into the high pressure chamber from the vertical oil passage;

Oil pressure process: When the camshaft is in the rising stage, the tappet pushes the lower end of the plunger to move up, 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 is reduced, the oil pressure rises, and the high pressure The fuel absorbed and stored in the cavity enters the steel ball chamber from the oil inlet concave oil pit and vertical oil passage, and the steel ball is pressed tightly against the opening of the oil inlet blind hole under the action of the pressure fuel, closing the oil inlet blind hole, and the pressure fuel Push the oil outlet valve core to move up, so that the oil outlet valve core is in the open state, and the pressurized fuel enters the pressure storage chamber through the constant pressure oil inlet channel of the single-cylinder common rail accumulator, and the pressure sensor controls the oil in the pressure storage chamber. When the oil pressure reaches the predetermined value, it is input into the fuel injection device 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, and can be directly installed and used on the existing diesel engine without additional processing of the installation hole system of the body of the diesel engine, and at the same time cancels the connection between the common rail and the The common rail pipe of the oil pump can also reduce the volume of the high-pressure common rail pump of the single-cylinder diesel engine to the greatest extent, and the high-speed solenoid valve is used to replace the proportional solenoid valve in the prior art, and the cost can be reduced by 10% to 15%; in the present invention, The lifting, moving, guiding and positioning structures of the tappet body are all set in the hole in the pump body, and there is no special design requirement for the diesel engine body; it can directly carry out common-rail EFI upgrade transformation on the existing diesel engine, and carry out the National III standard for the existing single-cylinder diesel engine Standard environmental protection emission is a very economical and feasible technical solution, and the single-cylinder diesel engine can meet the National IV emission standard by using the invention.

In the present invention, the plunger guide sleeve of the high-pressure element is separated from the pump body and designed into a multi-stage cylindrical structure, which is uniform and symmetrical in the circumferential direction, which is beneficial to the high-precision machining of the middle hole of the plunger sleeve in the later stage; compared with the prior art The special-shaped structure requires counterweight treatment, which greatly reduces the difficulty of the process; the moving parts such as the tappet body and the plunger spring are designed with an internal package structure, which avoids the possibility of collision, interference and influence with the diesel engine parts. The invention has the advantages of compact structure, low cost, good manufacturability and stable performance, and is suitable for a high-pressure common rail system oil supply pump assembly used by a single-cylinder diesel engine.

Description of drawings:

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the structural representation of single cylinder common rail accumulator among the present invention;

Fig. 3 is a structural schematic diagram of a single cylinder common rail pump;

Fig. 4 is the structural representation of pump body;

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

Fig. 6 is a structural schematic diagram of an oil channel distributor;

In the figure: 1-single-cylinder common rail accumulator; 2-single-cylinder common-rail pump; 3-end seal ring; 11-common rail body; 12-constant pressure oil outlet; Constant pressure oil inlet; 15-pressure sensor; 16-one-way oil outlet chamber; 17-oil inlet; 21-pump body; 25-plunger; 26-piston guide sleeve; 27-radial sealing ring; 28-high pressure chamber; 29-oil channel distributor; 30-steel ball; 31-inlet valve spring; 32-oil outlet valve seat; -Oil outlet valve core; 34-Oil outlet valve spring; 35-Oil outlet valve spring seat; 36-High-speed solenoid valve; 37-Limit pin; ; 213-cooperating hole; 214-transition hole; 215-lower guide hole; Oil passage; 294-vertical oil passage; 295-oil inlet concave oil pit; 321-oil outlet hole; 322-steel ball cavity; 323-upper oil inlet passage.

detailed description:

The specific embodiment of the present invention is described below in conjunction with accompanying drawing:

Embodiment 1: A composite 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 The accumulator 1 and the single-cylinder common-rail pump 2 are fixedly connected into one body through fasteners and end face sealing rings 3; Cavity 13, constant pressure oil inlet passage 14, pressure sensor 15 and one-way oil outlet chamber 16, pressure accumulator chamber 13 is arranged in 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 all connected with the pressure storage chamber 13, wherein 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 The pump 2 includes a pump body 21, a tappet body 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 electromagnetic valve 36, the center of oil outlet valve seat 32 is provided with an outlet The oil hole 321 is provided with a steel ball chamber 322 on the lower end surface of the oil outlet valve seat 32, and an upper side oil inlet passage 323 is provided on the side of the oil outlet valve seat 32; The oil inlet blind hole 291 is provided with a lower oil inlet passage 292 on the side of the oil passage distributor 29, and a horizontal oil inlet passage 293 is provided at the lower end of the lower side oil inlet passage 292 of the oil passage distributor 29. A vertical oil passage 294 is provided between the upper end surface and the lower end surface of 29, and an oil inlet concave oil pit 295 is arranged on the lower end surface of the oil passage distributor 29, and the vertical oil passage 294 communicates with the oil inlet concave oil pit 295; 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, a solenoid valve mounting hole 216 and a steering oil inlet 217, a docking hole 211, a threaded connection hole 212, and a matching hole 213 , transition hole 214 and lower guide hole 215 are coaxially distributed from top to bottom; hole 211, and the oil outlet valve seat 32 is located above the oil passage distributor 29, the steel ball 30 is set between the oil outlet valve seat 32 and the oil passage distributor 29, and 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 set 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 set on the upper section of the oil outlet valve core 33, and the oil outlet valve spring seat 35 is set on the In the inner hole of the upper end of the oil outlet valve spring 34, the plunger spring lower seat 23 is set on the plunger 25 and is located at the lower end of the plunger 25, and the plunger 25 is set in the guide hole of the plunger guide sleeve 26, and the plunger spring 24 is set between the plunger guide sleeve 26 and the plunger spring lower seat 23, 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 limited by the limit pin 37 bit, limit pin 37 is limited by The position is limited by the clamp spring 38, and the lower end of the plunger 25 is in contact with the tappet body 22; two radial sealing rings 27 are arranged between the plunger guide sleeve 26 and the matching hole 213 of the pump body 21.

There are many implementations of the present invention, and all schemes that adopt the same principles as those of the present invention and other functional substitutions all belong to the protection scope of the present invention.

Claims (9)

1. a single cylinder diesel combined type high voltage common rail pump, is characterized in that: include single cylinder common rail accumulation of energy Device (1) and single cylinder common rail pump (2), the oil inlet end of single cylinder common rail accumulator (1) and single cylinder common rail pump (2) Oil outlet end docking after be fixedly connected into hermetically one.

The most according to claim 1, single cylinder diesel combined type high voltage common rail pump, is characterized in that: institute State single cylinder common rail accumulator (1) include common rail body (11), level pressure oil road (12), pressure accumulation cavity volume (13), Level pressure oil input channel (14), pressure transducer (15) and unidirectional go out oil pocket (16), pressure accumulation cavity volume (13) sets Put in common rail body (11), level pressure oil road (12), level pressure oil input channel (14), pressure transducer (15) With unidirectional go out oil pocket (16) be all connected with pressure accumulation cavity volume (13), wherein, level pressure oil road (12), fixed Be pressed into oil duct (14) and unidirectional go out oil pocket (16) be coaxially disposed.

The most according to claim 1, single cylinder diesel combined type high voltage common rail pump, is characterized in that: described Single cylinder common rail pump (2) includes seat (23), plunger bullet under the pump housing (21), tappet body (22), plunger spring Spring (24), plunger (25), plunger guide set (26), radial direction seal ring (27), high pressure chest (28), oil Road allotter (29), steel ball (30), inlet valve spring (31), delivery valve seat (32), fuel-displaced spool (33), Oil outlet valve spring (34), oil outlet valve spring seat (35) and high-speed electromagnetic valve (36), in delivery valve seat (32) Center be provided with oil outlet (321), be provided with steel ball cavity volume (322) in the lower surface of delivery valve seat (32), Upside oil input channel (323) it is provided with in the side of delivery valve seat (32)；Center in oil duct allotter (29) It is provided with the oil-feed blind hole (291) of upper end open, is provided with downside oil input channel in the side of oil duct allotter (29) (292), it is provided with horizontal oil input channel (293) in downside oil input channel (292) lower end of oil duct allotter (29), Between the upper surface and lower surface of oil duct allotter (29), it is provided with vertical oil duct (294), distributes at oil duct The lower surface of device (29) is provided with the recessed oil pit of oil-feed (295), vertical oil duct (294) and the recessed oil pit of oil-feed (295) It is connected；The described pump housing (21) include butt hole (211), threaded connection hole (212), mating holes (213), Transitional pore (214), lower pilot hole (215), electromagnetic valve installing hole (216) and turn to oil input channel (217), Butt hole (211), threaded connection hole (212), mating holes (213), transitional pore (214), lower pilot hole (215) the most sequentially coaxially it is distributed；The screw thread that plunger guide set (26) is rotated with at the pump housing (21) connects Connecing in hole (212), oil duct allotter (29) and delivery valve seat (32) are arranged in butt hole (211), And delivery valve seat (32) is positioned at the top of oil duct allotter (29), steel ball (30) is arranged on delivery valve seat And between oil duct allotter (29), fuel-displaced spool (33) is sleeved on going out of delivery valve seat (32) (32) In oilhole (321), inlet valve spring (31) be arranged on fuel-displaced spool (33) lower end and steel ball (30) it Between, the lower end of oil outlet valve spring (34) is sleeved on the epimere of fuel-displaced spool (33), oil outlet valve spring seat (35) In the endoporus of the upper end being sleeved on oil outlet valve spring (34), under plunger spring, seat (23) is sleeved on plunger (25) Going up and be positioned at the lower end of plunger (25), plunger (25) is sleeved in the pilot hole of plunger guide set (26), Plunger spring (24) is arranged under plunger guide set (26) and plunger spring between seat (23), tappet body (22) it is sleeved in the lower pilot hole (215) of the pump housing (21), and by spacer pin (37) to tappet body (22) Lifting travel carry out spacing, the lower end of plunger (25) contacts with tappet body (22).

The most according to claim 3, single cylinder diesel combined type high voltage common rail pump, is characterized in that: at post It is provided with radial direction seal ring (27) between plug fairlead (26) and the mating holes (213) of the pump housing (21).

The most according to claim 4, single cylinder diesel combined type high voltage common rail pump, is characterized in that: at post It is provided with two radial directions between plug fairlead (26) and the mating holes (213) of the pump housing (21) axially spacedly Sealing ring (27).

The most according to claim 1, single cylinder diesel combined type high voltage common rail pump, is characterized in that: single cylinder The oil inlet end (17) of common rail accumulator (1) and the oil outlet end docking structure of single cylinder common rail pump (2) be: single The oil inlet end (17) of cylinder common rail accumulator (1) is sleeved in the butt hole (211) of the pump housing (21).

The most according to claim 6, single cylinder diesel combined type high voltage common rail pump, is characterized in that: single cylinder The oil inlet end (17) of common rail accumulator (1) and the oil outlet end of single cylinder common rail pump (2) seal docking structure, The oil inlet end (17) of single cylinder common rail accumulator (1) is sleeved in the butt hole (211) of the pump housing (21), Joint at common rail body 11 with the pump housing 21 is provided with sealing structure.

The most according to claim 7, single cylinder diesel combined type high voltage common rail pump, is characterized in that: common rail Body (11) and the pump housing (21) in the sealing structure of joint are, at common rail body (11) and the pump housing (21) End-face seal ring (3) it is provided with between interface.

The most according to claim 7, single cylinder diesel combined type high voltage common rail pump, is characterized in that: common rail The sealing structure that body (11) is provided with at joint with the pump housing (21) is, at single cylinder common rail accumulator (1) It is provided with radial seal between the butt hole (211) of oil inlet end (17) cylindrical and the pump housing (21).