CN1393644A

CN1393644A - Hydraulic advance servo unit

Info

Publication number: CN1393644A
Application number: CN 01122234
Authority: CN
Inventors: 康铧
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-06-21
Filing date: 2001-06-21
Publication date: 2003-01-29
Anticipated expiration: 2021-06-21
Also published as: CN1201093C

Abstract

A hydraulic servo advancer of diesel engine's injection pump for automatically regulating the optimal oil-supplying angle is composed of timing gear, guide straight key, end cover, flyball and is spring, piston with spiral spline pair coupler and servo valve. Its advantages are compact structure, small size, high reliability and power, and high precision and sensitivity.

Description

Hydraulic advance servo unit

The present invention relates to the hydraulic advance servo unit of the best fuel supply advance angle automatic control tegulatingdevice of a kind of diesel injection pump.

The size of fuel supply advance angle is very big to the working process of diesel engine influence, when advance angle is too big, because diesel oil is to spray under the situation that temperature is lower in cylinder, the mixed gas formation condition is poor, and delay of ignition is long, makes diesel engine work rough, unstable idle speed, starting difficulty.And advance angle too hour, and then diesel combustion maximum temperature and pressure descend, and make engine overheat, smoking of the exhaust, power character and Economy reduction.Best fuel supply advance angle can obtain peak output, and can reduce oil consumption, reduces discharging.Best fuel supply advance angle is not a constant in diesel engine work, but change with the variation of fuel delivery and diesel engine speed.Advancing device general and that the diesel engine in-line fuel injection pump matches has centrifugal two kinds of the centrifugal and interior installation tool of outer installation tool, also has a kind of hydraulic pressure advancing device (Chinese patent, the patent No.: 91204470.5) in addition.But there are the following problems for mechanical centrifugal advancing device: it is to rely on the centrifugal force of flyball to come work, and flyball must have enough weights and bigger activity space, the package unit complex structure, and volume is big and heavy.The diesel engine of some compact structure is adorned in-line fuel injection pump, the centrifugal advancing device of tool of then can't installing at present.For the hydraulic pressure advancing device, it can be loaded onto, but the hydraulic pressure advancing device is to come work by the engine oil pressure and the spring force balance of diesel engine, since the engine oil pressure of diesel engine not only with rotating speed variation in direct ratio, and different with the wear of diesel engines degree relevant with the foozle of diesel engine, the therefore necessary parameter of often adjusting the hydraulic pressure advance device spring is to adapt to the variation of diesel engine oil pressure, just can reach desirable best degree of advance, this results in hand cramps to use.Diesel engine is worked under the situation of advancing device not having, and its performance index obviously reduce.

Purpose of the present invention is exactly the defective at existing the problems referred to above of the centrifugal advancing device of machinery and the existence of hydraulic pressure advancing device, it is little to design a kind of volume, strength is big, with the irrelevant hydraulic advance servo unit of diesel engine lubricating oil variation in pressure, make diesel injection pump in different speed range, can both under best oil supply angle, work.Thereby improve the burning of diesel engine, increase power, reduce oil consumption, reduce discharging, reduce detonation pressure in the cylinder, improve the working life of diesel engine.

The concrete solution of the present invention is: hydraulic advance servo unit is by the Injection Pump timing gear, dive key, and piston assembly, coupling assembly, the servovalve assembly, end cap, flyball, the flyball spring is formed.Have piston hole in the middle of the Injection Pump timing gear, one end of piston hole has the dive key groove, the symmetrical position of dive key groove has the flyball groove, have the restraining groove of flyball rotating shaft in the flyball groove, the Injection Pump timing gear link with 4 screws with end cap and are bearing on the coupling assembly, block with pad and shaft-use elastic gear ring, seal (or at movable position employing clearance seal) with one group of O RunddichtringO in the position that produces external leakage.Coupling assembly is made up of shaft coupling and spacer shell, the outer round surface of shaft coupling has one section helical spline shaft, spacer shell and shaft coupling are press-fitted and in end face spot welding, shaft coupling and spacer shell can be made respectively, or with shaft coupling and the synthetic whole manufacturing of a part of spacer shell (powder metallurgy or precision casting), a taper hole and a dismounting tapped hole that links with fuel injection camshaft is arranged on the shaft coupling, be drilled with the spill port of Injection Pump lubricant oil and servovalve assembly on the shaft coupling.Piston assembly is made up of piston and plug, and outside piston has a keyway, the dive key screw, and spring washer is fastened on it in keyway, with the keyway symmetrical position pilot hole of a servovalve assembly and the corresponding P of servovalve assembly, a, b, O is being arranged ₁, O ₂R hydraulic fluid port position is drilled with oil channel hole, there is one section Turbo Flora keyhole in the central authorities of piston, remaining part is a unthreaded hole, piston assembly is contained in the annular cylinder barrel between Injection Pump timing gear and the coupling assembly, dive key is contained in the dive key groove of Injection Pump timing gear, the Turbo Flora keyhole of piston assembly matches with the helical spline shaft of coupling assembly, and (this pays helical spline can be that the involute helical spline is paid, or the rectangular coil spline is paid, or the helical spline of other sectional shapes is paid), the unthreaded hole of piston assembly central authorities matches with the coupling assembly spacer shell, piston assembly can be axially movable in annular cylinder barrel, and coupling assembly relatively rotates piston assembly simultaneously.The servovalve assembly is by spool, valve pocket before and after 2,2 working edge valve pockets, a central valve pocket, overcoat, bottom (overcoat and bottom can make respectively or with whole manufacturing of the synthetic part of overcoat and bottom) and Returnning spring composition, the servovalve assembly is assemblied in the respective aperture of piston, and its corresponding P, a, b, O ₁, O ₂, the R oil duct communicates.(can make respectively or unite two into one by the Returnning spring of flyball spring and servovalve assembly with the flyball spring for flyball, make a spring, be contained in the position of former servovalve Returnning spring, this moment, spring end face did not contact with bottom, but by a center pull rod of taking the lead, pass the spool center through hole, the cannelure of the flyball arm of force, screw on the end cap is strained spring), be contained in the flyball groove of Injection Pump timing gear, with Injection Pump timing gear contacting point one rotating shaft is arranged on flyball, be stuck in the corresponding restraining groove of Injection Pump timing gear, the spool of the arm of force of flyball and servovalve assembly is near contacting.

Below in conjunction with accompanying drawing the present invention is further described:

Fig. 1 is: the hydraulic advance servo unit structural drawing.

Among Fig. 1: 1-Injection Pump timing gear, 2,4,8,29, the 32-O RunddichtringO is (or with 8,29 remove disappear and adopt clearance seal), 3-cross recessed countersunk head sscrew, 5-dive key, 6-piston, 7-plug, 6,7 form piston assembly I, 9-shaft coupling, 10-excessively covers, 9,10 form coupling assembly II, 11-nut, 12-spring washer, 13-circlip for shaft, 14-pad, 15-spool, 16-front and back valve pocket, 17-working edge valve pocket, 18-middle valve pocket, 19-overcoat, 20-bottom, 21-Returnning spring, 15,16,17,18,19,20,21 form servovalve assembly III, 22-end cap, 23-flyball, 24-flyball spring, 25-gear chamber cover sealing gasket, 26-gear chamber cover, 27-gear chamber assembly, 28-Injection Pump, 30-spring washer, 31-screw, A-oil cylinder A chamber, B-oil cylinder B chamber, the filler opening of P-servovalve assembly III, the oil outlet in the logical oil cylinder A chamber of a-servovalve assembly III, the oil outlet in the logical oil cylinder B chamber of b-servovalve assembly III, O ₁The return opening in the logical oil cylinder A chamber of-servovalve assembly III, O ₂The return opening in the logical oil cylinder B chamber of-servovalve assembly III, R-total the return opening of servovalve assembly III, c, d, e-introduce the pressure oil duct of machine oil (perhaps from the machine oil main oil gallery of motor from motor, by Injection Pump (28), through fuel injection camshaft and and the inside oil duct of the conical surface that is connected of shaft coupling (9) and coupling assembly II, piston assembly I and the P mouth of the servovalve assembly III that arrives, introducing pressure oil).

Working procedure of the present invention: the transmission of power of (with reference to Fig. 1) hydraulic advance servo unit, be by Injection Pump timing gear (1),, promote piston assembly I by dive key (5), piston assembly I promotes coupling assembly II by helical spline, and arrives the camshaft of Injection Pump (28).The rotating speed induction of hydraulic advance servo unit then is by the flyball (23) in Injection Pump timing gear (1) flyball groove, under the different rotating speeds effect, produce different centrifugal force, and compression flyball spring (24), make the be diversion shaft fulcrum rotation of hammer (23) of the arm of force of flyball (23), and promotion is contained in the spool (15) of the servovalve assembly III on the piston assembly I, move corresponding position, for example rotating speed rises, spool (15) distance that moves right is opened an openings delta, by the engine oil pressure oil from diesel engine, enter oil cylinder A chamber by c-d-e-p-a, the oil return in oil cylinder B chamber at this moment is by oil duct b-O ₂-R gets back to gear chamber, under the pressure oil effect in oil cylinder A chamber, promotes piston assembly I and follows the direction that spool (15) moves, and the segment distance that moves right is closed until opening.Because piston (6) and shaft coupling (9) are that the helical spline that pair of matched is closed is paid, so piston assembly I moves right, and coupling assembly II is correspondingly rotation just, increases a dynamic degree of advance.In like manner, rotating speed descends, and spool (15) is moved to the left a distance, opens an openings delta equally, and pressure oil enters oil cylinder B chamber by oil duct c-d-e-p-b, and the oil return in oil cylinder A chamber at this moment is by oil duct a-O ₁-R gets back to gear chamber, under the pressure oil effect in oil cylinder B chamber, promotes piston assembly I and follows spool (15) movement direction, is moved to the left a segment distance, closes up to opening.Be that piston (6) and shaft coupling (9) are the helical splines that pair of matched is closed equally, therefore, piston assembly I is moved to the left, and coupling assembly II just correspondingly rotates, and reduces a dynamic degree of advance.By rotating speed-flyball centrifugal force-pressure spring-flyball arm of force rotation-spool move-piston moves-shaft coupling rotates advance angle, be to belong to positioning control in Hydrauservo System, as long as the active force (product of pressure and piston area) of piston is enough big, variation in pressure is irrelevant to the variation of degree of advance.The degree of advance that is hydraulic advance servo unit can become this to change with the rotating speed of diesel engine routinely, diesel injection pump can both be worked under best oil supply angle in different speed range, thereby improve the burning of diesel engine, increase power, reduce oil consumption, reduce discharging, reduce detonation pressure in the cylinder, improve the working life of diesel engine.

Outstanding effect of the present invention: the power transmitting elements guiding of the servo advancing device of hydraulic pressure Flat key, piston always become, the total one-tenth of shaft coupling and rotating speed sensing element flyball, flyball bullet Spring, servo valve assembly, the total Chengdu of piston are contained in oil spout pump timing pinion cavity, structure Compactness, volume is little, reliable operation, strength is big, and motion precision height is quick on the draw, The impact that not changed by engine oil pressure is suitable for assembling position, advancing device space especially Little, need again to export the occasion than high pulling torque.

Claims

1, a kind of for diesel injection pump provides best fuel supply advance angle self-regulating hydraulic advance servo unit, it is characterized in that:

A, described hydraulic advance servo unit be by Injection Pump timing gear (1), dive key (5), and piston assembly I, coupling assembly II, servovalve assembly III, end cap (22), flyball (23), flyball spring (24) is formed,

B, the described Injection Pump timing gear of above-mentioned a (1), the centre has piston hole, one side of piston hole has the dive key groove, the symmetrical position of dive key groove has the flyball groove, have the restraining groove of flyball rotating shaft in the flyball groove, Injection Pump timing gear (1) link with 4 screws (3) with end cap (22), and be bearing in together on the shaft coupling II, block with pad (14) and shaft-use elastic gear ring (13), in the position that produces external leakage with one group of O RunddichtringO (2), (4), (8), (29) sealing

The described coupling assembly II of e, above-mentioned a, form by shaft coupling (9) and spacer shell (10), the outer round surface of shaft coupling (9) has one section helical spline shaft, spacer shell (10) is press-fitted with shaft coupling (9), and in end face spot welding, shaft coupling (9) has a tapped hole of using with the taper hole and the dismounting of fuel injection camshaft binding, is drilled with the spill port of Injection Pump lubricant oil and servovalve assembly III on the coupling assembly II

The described piston assembly I of d, above-mentioned a, form by piston (6) and plug (7), the cylindrical of piston (6) has a keyway, dive key (5) screw (31), spring washer (30) is fastened on it in keyway, with the keyway symmetrical position pilot hole of a servovalve assembly III and the corresponding P of servovalve assembly III, a, b, O are being arranged ₁, O ₂R hydraulic fluid port position is drilled with oil channel hole, there is one section Turbo Flora keyhole in the central authorities of piston (6), remaining part is a unthreaded hole, piston assembly I is contained in the annular cylinder barrel between Injection Pump timing gear (1) and the coupling assembly II, dive key (5) is contained in the dive key groove of Injection Pump timing gear (1), the Turbo Flora keyhole of piston assembly I matches with the helical spline shaft of coupling assembly II, the unthreaded hole of piston assembly I central authorities matches with the spacer shell (10) of coupling assembly II, piston assembly I can be axially movable in annular cylinder barrel, coupling assembly II relatively rotates piston assembly I simultaneously

E, the described servovalve assembly of above-mentioned a III, by spool (15), valve pocket (16) before and after 2,2 working edge valve pockets (17), middle valve pocket (18), overcoat (19), bottom (20), Returnning spring (21) is formed, and servovalve assembly III is contained in the corresponding hole of piston (6), and its corresponding P, a, b, O ₁, O ₂, the R oil duct communicates,

F, the described flyball of above-mentioned a (23), it is in flyball spring (24) is contained in the flyball groove of Injection Pump timing gear (1), go up and there is a rotating shaft Injection Pump timing gear (1) contacting point at flyball (23), be stuck in the corresponding restraining groove of Injection Pump timing gear (1), the spool (15) of the arm of force of flyball (23) and servovalve assembly III is near contacting.

2, hydraulic advance servo unit according to claim 1, it is characterized in that coupling assembly II, shaft coupling (9) and spacer shell (10) can be made respectively, or with shaft coupling (9) and the synthetic whole manufacturing of a part of spacer shell (10) (powder metallurgy or precision casting).

3, hydraulic advance servo unit according to claim 1 is characterized in that overcoat (19) and the bottom (20) among the servovalve assembly III can be made respectively, or with overcoat (19), with whole manufacturing of the synthetic part of bottom (20).

4, according to the described hydraulic advance servo unit of claim 1, the pressure oil duct P that it is characterized in that servovalve assembly III, can be from the machine oil main oil gallery of motor, by gear chamber (27), oil duct on oil channel c, d, e and piston (6) is introduced pressure oil, or from the machine oil main oil gallery of motor, by Injection Pump (28), through fuel injection camshaft and and the inside oil duct of the conical surface that is connected of shaft coupling (9) and coupling assembly II, piston assembly I and the P mouth of the servovalve assembly III that arrives, introducing pressure oil.

5, hydraulic advance servo unit according to claim 1, it is characterized in that it can be that the involute helical spline is paid that helical spline that piston assembly I matches with coupling assembly II is paid, or the rectangular coil spline pays, or the helical spline of other sectional shapes is paid.

6, hydraulic advance servo unit according to claim 1, the Returnning spring (21) that it is characterized in that flyball spring (24) and servovalve assembly III, can make respectively or unite two into one, make a spring, be contained in the position of former servovalve Returnning spring (21), this moment, spring end face did not contact with bottom (20), but by a center pull rod of taking the lead, pass spool (15) center through hole, the cannelure of flyball (23) arm of force, the screw on the end cap (22) is strained spring.

7, hydraulic advance servo unit according to claim 1, it is characterized in that Injection Pump timing gear (1) are bearing on the coupling assembly II with end cap (22), can remove the employing clearance seal that disappears with O RunddichtringO (8), (29) sealing or with O RunddichtringO (8), (29).