RU2558179C1 - Electrohydraulic injector - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: electro-driven injector includes housing (1) with fuel supply channel (2) and drain channel (28), sleeve (19) of a multiplier, in which locking multiplier (20) is installed, which interacts with needle (7) through pusher (14) and forms one hydro-control chamber (29) that is interconnected with fuel supply channel (2) through jet nozzle (24) and through its control valve (30) to drain channel (28); spring-loaded pusher (32) of the control valve is connected to armature (33) of an electromagnet; sprayer (3) and needle (7) interact with locking multiplier (20) through pusher (14) and to its seat (4). Spacer plate (12) spring-loaded towards locking of needle (7) is installed between multiplier (20) and pusher (14). Such design of the injector allows increasing movement speed of needle (7) at the end of its stroke till shutoff of spraying openings (5) by using elastic deformation of pusher (14) in case length of pusher (14) does not allow a value of its elastic deformation equal to preliminary deformation of the pusher at assembly of the injector, which is added to needle (7) lift value, as well as reduction of cross-section of jet nozzles (24) for the purpose of economy of fuel consumed for control without any loss of speed of putting needle (7) onto seat (4).

EFFECT: higher efficiency.

7 cl, 5 dwg

Description

Technical field

The invention relates to engine building, in particular to nozzles with microprocessor control for fuel injection into the cylinder of an internal combustion engine.

State of the art

Known electro-hydraulic nozzle of a diesel engine with a fuel supply system according to DE 19701879, comprising a housing with fuel supply and drain channels and a through axial cavity mounted thereon, a hollow atomizer with nozzle openings mounted on the housing, a needle mounted in the atomizer cavity to form a needle chamber and paired with the bearing part of the locking multiplier, the needle locking spring, the centering spacer, the sealing part of the locking multiplier, made in the form of a piston, di meter which exceeds the diameter of the sealing portion of the needle and which is precisely installed in the sleeve locking multiplier to form a hydraulic control chamber, the orifice hydraulic control chamber hydraulic control valve ball, rod, anchor, an electromagnet and a spring hydraulic control valve.

In this nozzle, all spray openings open simultaneously, which narrows the range of fuel injection control and requires to expand the range of regulation of the use of a high-pressure fuel pump (TNVD) with adjustable fuel pressure, which reduces the response rate of the car.

The closest solution is an electro-hydraulic diesel injector with a fuel supply system according to patent RU 2303157, which contains a housing with a high-pressure fuel supply channel and a drain channel, a multiplier sleeve in which a locking multiplier is installed to form a hydraulic control chamber in communication with the high-pressure fuel supply channel by means of a nozzle, and with a drain channel through a control valve, the spring-loaded stem of which is connected to the armature of an electromagnet, a spray gun with a saddle, a needle chamber and spray holes, and a needle interacting with the saddle and with the locking multiplier through the pusher.

The disadvantages of this technical solution is the relatively low speed of the needle at the moment of closing the spray holes, which is equal to the speed of the multiplier, driven by the fuel passing through the nozzle, the cross section of which is minimal in order to reduce fuel consumption for nozzle control, as well as the complexity of manufacturing the nozzle itself with a small cross section.

The objective of the invention is to increase the speed of the needle at the end of its stroke until the spray holes are blocked using elastic deformation of the pusher, in the case when the length of the pusher does not allow the value of its elastic deformation equal to the preliminary deformation of the pusher during assembly of the nozzle, folded with the magnitude of the rise of the needle, and also reducing the fuel used for control by reducing the cross section of the throttle holes.

Disclosure of invention

This problem is solved in an electro-hydraulic nozzle containing a housing with a high-pressure fuel supply channel and a drain channel, a multiplier sleeve in which at least one locking multiplier is installed, interacting, respectively, with at least one needle through the pusher, and forming, respectively, at least one hydraulic control chamber, which is in communication with the high-pressure fuel supply channel through the nozzle, and through its control valve with a drain channel, a spring-loaded control rod the valve, connected with the armature of the electromagnet, a spray gun and at least one needle interacting with the corresponding locking multiplier through the pusher and with its seat. According to the invention, a spacer is installed between the multiplier and the pusher, spring-loaded in the direction of locking the needle.

Preferably, the movement of the spacer in the direction of raising the needle is limited by a thrust element in contact with the sleeve of the multiplier.

Preferably, the thrust element is made in the form of a washer, and the spacer has a protrusion passing through this washer and in contact with the multiplier, the protrusion area and the area of the remaining supporting surface of the spacer being essentially equal.

Preferably, in the free state, the gap between the supporting surface of the spacer and the washer is 0.9-1.1 times the needle travel minus the amount of deformation of the pusher by the working pressure of the fuel on the differential pad of the needle.

The nozzles and the supply channel can be made in the form of grooves on the end of the multiplier cover, overlapped by the end of the multiplier sleeve and / or grooves on the end of the multiplier sleeve, overlapped by the end of the multiplier cover.

In the cross section, the nozzle and the feed channel are predominantly triangle-shaped, with the cross-sectional area of the feed channel being 3-5 times the sum of the cross-sectional areas of all the nozzles.

This solution is most effective in multi-needle nozzles with independent needle control and multiple multipliers, but unlike nozzles with a pre-compressed plunger, it expands their applicability for shorter elastically deformable pushers and different atomized fuel pressures, which makes it possible to use them in a single-needle design.

Limiting the movement of the spacer in the direction of raising the needle more precisely determines its position at the time of closing the control valve and reduces the stroke of the multiplier due to additional deformation of the pusher with fuel pressure acting on the entire cross section of the needle. This increases fuel metering accuracy.

In addition, this design solution allows you to perform jets using, for example, a disk cutter or a disk abrasive steak sharpened along the profile of the throttle holes, while obtaining the minimum required cross-sectional area, as well as perform the feed channel with the same tool.

The minimum area of the supply channel is determined by the allowable loss of fuel pressure in it, and the maximum is determined by the strength characteristics of the walls of the supply channel with the location of the hydraulic control chambers as close as possible to the center of the nozzle.

Features and advantages of the invention will be better understood from the description of the preferred embodiment with reference to the attached drawings.

Brief Description of the Drawings

Figure 1 presents the nozzle, a General view in section;

figure 2 - remote element A in figure 1 on an enlarged scale;

figure 3 - section bb in figure 1 on an enlarged scale;

figure 4 - section CC in figure 1 on an enlarged scale;

figure 5 is a cross-section D-D in figure 1 on an enlarged scale.

An embodiment of the invention

As shown in figure 1, the nozzle contains a housing 1 with a channel 2 high pressure and a spray 3 with three seats 4, in which the spray holes 5 are made. Different numbers of holes 5 or their diameters can be different in different seats 4. The sprayer 3 is pressed against the housing 1 by the nut 6. Three needles 7 are located inside the sprayer 3, the upper part 8 of each of which in cross section has the form of a circle sector and passes through the precision hole 9 in the sprayer 3. The springs 10 resting against the washer 11 press the needles 7 through the spacer 12 disposed in the guide sleeve 13 and the pushers 14 of the seats 4. The pushers 14 are elastically deformable and are made of spring steel wire marks 65G with tensile strength 2500 n / mm ^2, the compression deformation preventing value commensurate with Odom needle. Spacers 12 from displacement are held by a figured hole in the guide sleeve 13 and between each other by flats 15 (Fig. 5), as well as by holes in the washer 11 (Fig. 1), thus forming channels 16 (Fig. 5) for fuel flow. For the same purpose, there is an opening 17 (FIG. 2) in the washer 11. The spacer 12 has a protrusion 12 ′ extending through the washer 11 and in contact with the multiplier 20, the protrusion 12 ′ and the remaining supporting surface of the spacer 12 being substantially equal. The pushers 14 (figure 4) are located in the guide holes 18 made in the housing 1 on a wire EDM machine.

The sleeve 19 (figure 1) of the multiplier with the multipliers 20 and the cover 21 of the multiplier are fixed from rotation by a pin 22 and pins 23 (figure 3), pressed into the housing 1 and passing through the guide sleeve 13, the washer 11, the sleeve 19 (figure 1) the multiplier into the cover of the 21 multiplier. The pin 22 has an opening for the passage of fuel to the nozzles 24, interconnected by a common channel 25 (Fig.1-3), made in the cover 21 of the multiplier, bottom covered by the end face of the sleeve 19 of the multiplier. The cover 21 of the multiplier with the grooves 26 is pressed by the drain pipe 27 with the drain channel 28. Each hydraulic control chamber 29 (figure 2) through the holes of the valve 30, radial grooves 31 and the central hole in the push rod 32, the radial grooves in the armature 33 (figure 1), the hole 34, the grooves 26 is connected to the drain channel 28. To prevent fuel from flowing directly from the control valve 30 to the drain channel 28, a sealing ring 35 is located in the groove of the multiplier cover 21. Sealing the joint between the multiplier sleeve 19 and the multiplier cover 21 provides It is due to the high-precision fit of the contacting surfaces.

Each of the three electromagnetic drives consists of a winding 36, the ends of which are welded to the contacts 37, which in turn are attached to the insulator 38 by hot deformation of the protrusions of the insulator (not shown in the figures), passed through the holes in the contacts 37 and filled with plastic in the manufacture of the pads 39, the magnetic circuit 40, the sleeve 41 and the anchor 33, mounted on the elastic disk of the pusher 32 through the ring 42. The magnetic circuit 40 is compressed in the sleeve 41, which is pressed by the nut 43. The tightness of the connection of the sleeve 41 with the housing 1 is provided by a seal ring 44. The rod 32 under the action of the spring 45 through the spacer 46 (figure 2) presses the ball control valve 30 against the seat made in the cover 21 of the multiplier. The stroke of the rod 32 (Fig. 1) is set by the interchangeable washer 47, and the minimum clearance between the armature 33 and the magnetic circuit 40 is the protrusion of the cup 48 made of non-magnetic material beyond the end of the magnetic circuit 40. The size of the socket for the spring 45 is regulated by the interchangeable washer 49.

To separate the high-pressure cavity from the drainage cavity, the cross section of the upper part 8 of the needles 7 at the level of the precision hole 9 in the spray gun 3, as noted above, is a circle sector with an angle of 120 °, and their contact surfaces at the level of the precision hole 9 are also made precision. Fuel, which nevertheless leaked through the gap between the precision part 8 of the needles 7 and the atomizer 3 through the grooves 50 (Fig. 4) in the housing 1 (Fig. 1), the radial groove in the guide sleeve 13, the annular gap between the guide sleeve 13, the washer 11 and housing 1, the channel formed by flats on the sleeve of the multiplier and the cover 21 of the multiplier and the housing 1, passes to the control valve 30 and then, as described above, into the drain channel 28. On the middle part of the needles 7 flats 51 are left in the plane forming the upper part needles 7, to give additional stability to the needles 7. In this case, the needles 7 are in contact with the nozzle 3 along the inner surface of its hole, and between them through the flats 51 of the radial surfaces of the sectors. The nozzle 52 with a slotted filter is sealed with a metal ring 53. The drain fitting is sealed with a rubber ring 54.

The nozzle works as follows. When high pressure fuel is supplied through channel 2 to the cavity of the atomizer 3, it simultaneously passes through all the hydraulic control chambers 29 through the hole in the pin 22, channel 25, jets 24, (Fig. 2). Since the cross-sectional area of each multiplier 20 (FIG. 1) is larger than the area of the upper part 8 of the needle 7, the fuel pressure moves the multiplier 20, deforms the pusher 14, further pressing the needle 7 against the seat 4.

When voltage is applied to the contacts 37, the anchor 33 is attracted to the magnetic circuit 40, moving the rod 32 through the washer 42 all the way into the end of the glass 48, opening the control valve 30. In this case, the fuel through the grooves 31 (figure 2) and the central hole made in the rod 32 , the radial grooves in the armature 33 (Fig. 1), the openings 34, the grooves 26 enter the drain channel 28, cooling the magnetic circuit 40. Since the cross section of the hole in the control valve 30 is much larger than the cross section of the nozzle 24, the pressure in the hydraulic control chamber 29 (Fig. 2 ) drops sharply, and the spacer 12, compressing the spring 10, under the action of the elastic deformation forces of the pusher 14 (Fig. 1) moves up until the force of the multiplier 20 through the spacer 12 on the pusher 14 is equal to the force acting on the pusher 14 from the needle 7, caused by the pressure of the fuel on the differential platform of the needle 7. After that, the multiplier 20 together with the pusher 14, the spacer 12 and the needle 7 moves up until the fuel gets into the pigle space, creating additional force. In this case, the needle 7, deforming the pusher 14, moves all the way into the housing 1 at a speed greater than the multiplier 20, providing faster opening of the spray holes and finer atomization of the fuel. In this case, the spacer 12, choosing the gap "a" (figure 2), rests on the washer 11 and the pusher 14 (figure 1) under the action of the fuel pressure force acting on the needle 7, is again deformed, storing the energy of compression deformation.

When the electromagnet is turned off, the pusher 32 under the action of the spring 45 through the spacer 46 (figure 2) closes the valve 30, and through the washer 42 (figure 1) moves the anchor 33.

When the valve 30 is closed, the pressure in the hydraulic control chamber 29 increases. In this case, the multiplier 20 moves downward, compressing the pusher 14 through the spacer 12, and when the force from the multiplier 20 to the pusher 14 exceeds the force exerted on it by the needle 7, which is pressed against the housing 1 by the fuel pressure, acting on the entire cross-sectional area of the needle 7, the multiplier 20, the spacer 12, the pusher 14 and the needle 7 are moved down. When the pressure drops in the podigolnoy chamber, the needle 7 begins to move at a speed greater than the speed of the multiplier 20, due to the elastic straightening forces of the pusher 14.

The elimination of the preliminary compression of the pushers 14 when assembling the nozzle and the introduction of springs 10 to close the needles 7 with the engine idle extends the applicability of the design of nozzles with elastically deformable pushers 14 with a small length, i.e. when the permissible deformation of the pushers 14 is less than the sum of the preliminary compression values of the pushers 14 and the needle stroke 7.

The abutment of the supporting surface of the spacer 12 in the lower end of the multiplier sleeve 19 through the washer 11 with the needle 7 raised while the elastically deformable pushers 14 are deformed clearly defines the position of the multipliers 20 at the beginning of movement when closing the valve 30 at high doses of fuel injection and reduce the likelihood of oscillation processes in elastically deformed pushers 14.

Owing to the above-described embodiment of the throttle holes 24, their bore may be minimal, but sufficient to control the multiplier 20, while the fuel consumption spent on the control is minimally possible.

Use in the design of elastically deformable pushers 14 allows to reduce the cross section of the throttle holes 24 without reducing the speed of lifting and landing of the needles 7.

Claims (7)

1. Electro-hydraulic nozzle containing a housing (1) with a channel (2) for supplying high-pressure fuel and a drain channel (28), a sleeve (19) of the multiplier, in which at least one locking multiplier (20) is installed, interacting with at least one at least one needle (7) through the pusher (14) and forming at least one hydraulic control chamber (29), which is in communication with the high pressure fuel supply channel (2) through the nozzle (24), and through its control valve (30) - with drain channel (28), spring-loaded stem (32) a control valve (30) connected to an electromagnet armature (33), a spray gun (3) and at least one needle (7) interacting with a corresponding locking multiplier (20) through a pusher (14) and with its seat (4) ), characterized in that between the multiplier (20) and the pusher (14) a spacer (12) is installed, spring-loaded in the direction of locking the needle (7). 2. Electro-hydraulic nozzle according to claim 1, characterized in that it contains a thrust element in contact with the sleeve (19) of the multiplier and restricting the movement of the spacer (12) in the direction of the needle (7). 3. Electro-hydraulic nozzle according to claim 2, characterized in that the thrust element is made in the form of a washer (11), and the spacer (12) has a protrusion (12 ′) passing through this washer (11) and in contact with the multiplier (20), moreover, the area of the protrusion (12 ′) and the area of the remaining supporting surface of the spacer (12) are essentially equal. 4. Electro-hydraulic nozzle according to claim 2, characterized in that in the free state, the gap between the supporting surface of the spacer (12) and the stop element is 0.9-1.1 needle travel (7) minus the amount of pusher deformation (14) working fuel pressure acting on the differential pad of the needle (7). 5. Electro-hydraulic nozzle according to claim 1, characterized in that the pusher (14) is made elastically deformable. 6. Electro-hydraulic nozzle according to claim 1, characterized in that the nozzles (24) and the supply channel (25) are made in the form of grooves at the end of the cap (21) of the multiplier, overlapped by the end of the sleeve (19) of the multiplier, and / or at the end of the sleeve ( 19) a multiplier overlapped by the end face of the multiplier cover (21). 7. Electro-hydraulic nozzle according to claim 4, characterized in that in the cross section the nozzle (24) and the inlet channel (25) have the shape of a triangle, and the cross-sectional area of the inlet channel (25) is 3-5 times larger than the sum of the cross-sectional areas of all nozzles (24).

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