JPS5817349B2 - Oufukudou Piston Gatanainenkikanyoufunsyaben - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an injection valve for a reciprocating piston type internal combustion engine, which is equipped with a hollow cylindrical injection hole holder having at least two rows of injection holes communicating outward and located above and below. The injection hole holder has a seating surface below the injection hole, a seating surface corresponding to the seating surface is formed in a lower portion of the injection valve casing, and the injection hole holder has a return spring. In the inactive position, the injection hole is located in a recess of the injection valve casing which closes the injection hole, and is moved to the injection hole open position by the load of the fuel supply pressure.

This type of injection valve is disclosed in patent number 802.9 of the Federal Republic of Germany.
It is known based on the specification No. 68.

In this known injection valve, the injection orifice is freely guided in a holder which is arranged in a recess.

Furthermore, this holder is provided with only one row of holes.

A disadvantage of this known injection valve is that even in the inactive position fuel can drip into the combustion chamber between the injection hole holder wall and the injection valve casing wall. This is because the chamber communicating with the injection hole is always under pressure even in the inactive position of the injection valve.

There is no sufficient separation between the combustion chamber and the injection hole communication chamber.

These fuels dripping into the combustion chamber form residues of fuel that are no longer completely combusted, so that the exhaust gas naturally has unacceptable impurities.

A further disadvantage is that fuel is injected into the combustion chamber from only one row of injection holes at each interval.
The problem with this known device is that the injection quantity can only be metered over the length of the injection time.

The object of the invention, starting from the above-mentioned known technology, is to provide an injection valve which makes it possible to achieve optimal metering and mixing of fuel and air in all power ranges and to avoid contamination by trailing fuel. The goal is to provide the following.

The object of the invention to solve this problem is that the injection hole support is formed by a sleeve, which rests loosely on the spindle in which the return spring is engaged. and in the inactive position, the spindle head is maintained in contact with a corresponding seating surface of the lower part of the injection valve casing, and the injection hole in the sleeve extends approximately tangentially to the inner wall of the sleeve. It is in the point where it is arranged.

By this means, optimum metering and good mixing of fuel and air are achieved over the entire load range by means of several rows of injection holes located one above the other; for example, in the low load range, e.g. when the engine is idling, only the injection holes in the bottom row can be achieved. only used.

If the load on the engine increases, the injection holes in the upper row are used after the injection hole holder has progressed through a predetermined stroke and the ignition delay has elapsed.

This avoids harsh operation and insufficient fuel regulation in the low and medium load range.

A further advantage is that, after the injection has ended, the injection holes are closed off by the fuel can, so that no fuel can drip into the combustion chamber and contaminate it.

This results in good exhaust gas emissions and favorable fuel consumption.

It is advantageous to design the sum of the flow cross-sectional areas of the injection holes in the lower row that opens first to be smaller than the flow cross-sectional area of the injection holes in the higher row.

This embodiment makes it possible to meter the injection quantity in such a way that only at the beginning of the stroke a strongly atomized fuel injection stream is injected into the combustion chamber with a small penetration depth.

In this way, the amount of fuel injected into the combustion chamber during the ignition delay and impulsively combusted after ignition is reduced, and the fuel injection flow is
It captures the air near the cylinder liner wall without adhering to the cylinder wall and moves toward the main injection. It is carried out with a certain delay.

In a preferred embodiment of the invention, a brake piston is secured to the spindle, which is branched off by a throttle and is loaded with fuel at a pressure lower than the supply pressure.

This controls the temporal movement of the spindle.

A brake piston fixed to the spindle prevents the spindle from descending too quickly.

In the annular chamber filled with leaked fuel, the brake piston is braked together with the spindle when the brake piston enters the leaked fuel after closing the overflow hole.

The pressure of the fuel which loads the brake piston is influenced by a damping piston, on which is fixed a spring which acts from the outside with a variable initial force.

As a result, the time course of the movement of the spindle is influenced within certain limits.

The braking pressure, which can be adjusted externally via a suppression spindle, makes it possible to have a number of fuel injection valves with the same delivery at idle.

The invention will now be described in detail with reference to the drawings.

The injection valve, generally designated 1 in FIG. 1, has an outer threaded sleeve 2.

The threaded sleeve 2 closes off a lower part 3 of the injection valve casing, which with its injection end faces an inner wall 5 of the cylinder head (not shown) facing the combustion chamber 4. Fixed.

The threaded sleeve 2 is fixed to the upper part of the injection valve casing of the multi-part injection valve 1 by an internal thread 6 provided on the inner wall of the threaded sleeve 2, so that the lower part 3 of the injection valve casing and the injection The valve casing upper part is fastened to the fuel can by the threaded sleeve 2.

The rear end of the upper molecule of the injection valve housing is fitted loosely through an opening 8 in the schematically illustrated outer wall 9 of the cylinder head and is beveled in the ring-like shape of the threaded sleeve 2 in the lower region 10. A portion 11 of the cylinder head is in close contact with an inclined surface 12 of the outer wall 9 of the cylinder head.

A recess 13 is bored in the lower part 3 of the injection valve casing on the combustion chamber side, into which a sleeve-shaped injection hole holder 14 is loosely and rotatably inserted.

The injection hole holder 14 is held within the recess 13 by a spindle head 16 integrally formed with the spindle 15.

Said recess 13 communicates with a recess called a fuel front chamber 18 .

The lower part 3 of the injection valve casing has a ring-shaped inclined seat surface 19 on the combustion chamber side.

Since the corresponding inclined seat surface 20 of the injection hole holder 14 is in contact with this inclined seat surface 19 under the spring force of the spring 32 in the inactive position of the injection valve 1, a fuel-sealed portion is created.

In this injection hole holder 14, a plurality of rows of injection holes 21 and 22 arranged one above the other are provided, and furthermore,
The diameter of the injection holes 21 in the lower row facing the combustion chamber 4 is designed to be smaller than the diameter of the injection holes 22 in the upper row.

It is also possible to provide intermediate rows of injection holes in order to achieve the best intermediate conditions between idling operation and full-load operation.

The injection holes 21 in the lower row are arranged so as to substantially align with the ring-shaped inclined seat surface 190 of the lower part 3 of the injection valve casing.

A spindle 15 that holds the injection hole holder 14 in its position.
passes through the center hole 23 of the injection hole holder 14.

Above the fuel front chamber 18, the spindle 15 has a larger diameter.

The diameter of the center hole 24 of the lower part 3 of the injection valve casing through which the large diameter part of the spindle 150 passes is
The size is designed such that a constriction exists between the center hole 24 and the center hole 24.

In the lower region, the spindle 15 has a ring-shaped addition 25
The inner circumferential wall of the center hole 23 of the injection hole holder 14 is in contact with the inner circumferential wall of the center hole 23 of the injection hole holder 14.

This annular extension 25 serves as a guide for the spindle 15 in the injection hole holder 14 .

The center hole 23 of the injection hole holder 14 communicates with the fuel front chamber 18 .

In the upper part of the injection valve casing, which is also penetrated to a certain extent by the spindle 15, the spindle 15
A brake piston 26 is located which is fixedly connected to the brake piston, the lower edge 2γ of which forms the upper limit of the annular chamber 28, whereas a brake piston 26 provided in the lower part 3 of the injection valve casing is The upper surface of the ring member 29 forms the lower limit of the annular chamber 28 .

The outer periphery of the annular chamber is the center hole 3 of the upper molecule of the injection valve casing.
0 is limited by a guide member 31 provided within the 0.

A spring 32 is located on this guide member 31.

The guide member 31 is pressed and tightened onto the upper surface of the tensioning ring member 29 by the upper portion l of the injection valve casing.

In the area of its upper edge 21, the brake piston 26 is constructed in such a way that a throttle cap γ3 occurs between the guide member 31 and the brake piston 26.

A sleeve 33 is interposed between the brake piston 26, which is fixedly connected to the spindle 15, and the spindle 15, and is fastened to the spindle 15 by means of an extension 11.

A member designed as a spacer sleeve 34 is provided on the brake piston 26 .

The spacer IJ+34 is guided along the outer circumference of the spindle 15.

The spacer sleeve 34 has an inclined surface 36 in its lower region 35 .

The spacer sleeve 34 has a spring 32 in the upper region 3r.
It has a ring-shaped protuberance 38 for contacting.

This spring 32 is in contact with an extension 39 of the guide member 31 at its lower end.

Above the spring 32, the ball bearing 40 is connected to the spacer sleeve 34.
The upper end of the spring 32 is fitted onto the outer periphery of the ball bearing, and the upper end of the spring 32 is abutted against the ball bearing.

A nut 41 that is screwed onto the thread 42 of the spindle 15 to hold the various members together is provided on the ball bearing 40, and by screwing the nut, the initial spring force of the spring 32 is adjusted to a predetermined value. .

The sleeve 33 and the spacer sleeve 34 can prestress the brake piston 26 via the nut 41 in order to minimize the loads on the thread of the spindle 15 and on the bearing shoulder of the sleeve 33.

The sealing sleeve 43, which has play all over, ensures the highest possible movement of the spindle 15 in the prestressed guide member 31 above the tensioning ring member 29.

In the upper part of the injection valve casing shown in FIG. 1, outer holes 44 and 45 are bored in line with the center hole 30.

The outer bore 44, also referred to as the fuel supply bore, communicates with a bore 46 extending obliquely in the lower part 3 of the injection valve casing,
The inner body of this hole 46 opens into the fuel front chamber 18 .

The outer hole 45 communicates with the annular chamber 28 via a relatively large hole 4γ and two relatively small overflow holes 48, 49.

In FIG. 2, the upper part l of the injection valve casing continues upwards.

Here, the hole 50 communicates with the central hole 30 which houses the spindle device.

The inner body of this hole 50 communicates in the upper region 51 via an overflow hole 52 with a large eccentric hole 53 .

In the lower region 54, the large eccentric bore 53 communicates with the outer bore 45 already described in FIG. 1, so that communication occurs between the central bore 30 and the eccentric bore 53.

A spring 55 is supported in the lower region 54.

On the spring 55 there is a check valve 56 configured as a ring.
is located.

A guide bushing 5γ for a damping piston 58 is provided in the eccentric bore 53, and the damping piston 58 slides within the guiding bushing 5γ.

This guide bushing 5γ has a two-part structure, and the ring-shaped check valve 56 is supported on a ring-shaped edge 59 which is chamfered obliquely at the lower part of the guide bush 5γ.

The damping piston 58 itself rests on an inclined surface γ4 formed in the lower part of the guide bush 5γ.

By configuring the outer shell of the damping piston 58 and the guide bush 5γ as well as the ring-shaped check valve 56 in this manner, a ring-shaped hollow space 60 is formed between these parts.

The damping piston 58 has an internal bore 61 which adjoins a small diameter blind bore 62 .

The internal hole 61 further communicates via an overflow hole 63 with an annular chamber 64 formed in the inner circumferential wall of the lower part of the guide bushing 5γ.

The internal hole 61 of the buffer piston 58 is covered by a spring plate 65 having a through hole, and the spring plate has a protrusion 66 that fits into the internal hole 61 .

A protrusion 6γ provided on the splash plate in the opposite direction to the protrusion 66 serves as a mounting portion for the spring 68.

A suppression spindle 69, which is actuated from the outside, acts on this spring 68.

Via this damping spindle 69 it is possible to adjust the initial spring force of the spring 68 as required.

In the upper region 51, in the wall of the upper molecular of the injection valve casing,
A screw tO is screwed in, which is used to bleed air from the fuel injection system.

The outer hole (fuel supply hole) 44 already mentioned in the explanation of FIG.
also penetrates the upper molecule of the injection valve casing shown in FIG.

For clarity, the same reference numerals are used in FIG. 3 as in FIG. 1.

That is, in FIG. 3, the inner wall of the cylinder head (not shown) facing the combustion chamber 4 is denoted by 5, the piston is denoted by γ1,
The arched top surface of the piston is designated by γ2.

Furthermore, as can be seen from FIG. 3, along the central longitudinal axis A-A,
A system of injection holes 21, 22 located one above the other is arranged.

The injection holes 21 in the first row or lower row are centered on the vertical axis A-A.
It has an inclination angle of about 75 to 80 degrees with respect to the main body.

FIG. 4 shows the injection holes 22 in the upper row.

The injection hole 22 is aligned with the center longitudinal axis A-A of the injection hole holder 14.
It is arranged tangentially to a circle centered at .

When the present invention is applied, fuel is supplied to the fuel front chamber 18 via the outer hole 44 as a fuel supply hole and the inclined hole 46, and the fuel front chamber 18 and the injection hole holder 14
The center hole 23 inside is filled.

When the pressure inside the fuel front chamber 18 increases and the initial spring force of the spring 30 is overcome based on the pressure acting on the lid surface of the recess 13 and the center hole 24, the spindle 15 moves to the injection hole holder. 14
is driven through.

At the same time, the injection hole holder 14 is separated from the inclined seating surface 19 of the lower part 3 of the injection valve casing, and the small diameter injection holes 2 of the lower row
1, that is, pre-injection is performed through the injection hole facing the combustion chamber 4.

In this case, the fuel is brought only close to the combustion chamber walls or the cylinder liner, and fuel adhesion to the walls is avoided.

By means of the brake piston 26, which is fixedly connected to the spindle 15, the leakage fuel present in the annular chamber 28 is forced out through the overflow hole 48, 49 and through the throttle gap γ3.

By suitably designing the aperture gap γ3, the temporal movement of the spindle 150 is controlled.

The entire hollow space provided between the brake piston 26 and the damping piston 58 is filled with leakage fuel.

A brake piston 26 fixedly connected to the spindle 15 is
Speeding up the downward movement of the spindle 15 and thus the injection hole holder 14 and the spindle 15 relative to the tensioning ring member 29
Its role is to avoid collisions between vehicles, and to ensure that main injection is performed only after a temporal ignition delay has elapsed.

The leaked fuel in the annular chamber 28 thus acts as a cushion for the brake piston 26.

Since every stroke of the spindle 150 a small amount of fuel is pumped into the annular chamber 28 through the central hole 24, this annular chamber 28 is always filled with leakage fuel.

The leakage fuel forced out by the brake piston 28 escapes from the overflow hole 48,49 into the outer hole 45 and from there into the lower region 54 of the large eccentric hole 53.

During the pre-injection by the injection hole 21, the injection hole holder 14 is rotated based on the reaction principle (see FIG. 4).

The spindle 15 has a ring-shaped additional portion 25 that contacts the inner peripheral surface of the injection hole holder 14 within the range of the inclined seating surface 20 of the injection hole holder 14. They are rotated together by friction.

The sealing sleeve 43, which has play all over, is connected to the annular chamber 2.
8 as well as minimal leakage losses of the tensioning ring member 2
The hydraulic thrust formed between the brake piston 26 and the tensioning ring element 29 guarantees a maximum mobility of the spindle 15 in the prestressed guide element 31 above the 9. Between the bearing and the ball bearing 40 the spindle 15 can rotate after the overflow holes 48, 49 are closed.

Only after the spindle 15 has made a predetermined stroke and the ignition delay has elapsed, the large injection holes 22 of the upper row are used and the main injection begins.

This principle avoids both poor operation and insufficient fuel preparation in the low and medium load range.

Exhaust gas emissions are therefore also significantly improved.

The injection holes 21 and 22 of the injection hole holder 14 are tightly sealed with fuel by the lower part 30 of the injection valve casing 30 and the inclined seating surface 20 of the injection hole holder 14, so that the combustion chamber 4 It also avoids defilement of the environment.

During the rotational movement, the fuel jet spreads over the entire circular surface inside the cylinder liner, resulting in a good mixing effect.

During the rotational movement introduced by the injection hole 21 of the pre-injection,
The injection hole 21 has an angle of 75 to 8 with respect to the central longitudinal axis A-A.
With an inclination angle of 0°, the injection holes 21 simultaneously generate a vortex in the combustion chamber 4 and thus act on the main air in the area of the cylinder liner, cylinder head and piston top surface γ2. .

By forming a vortex during the ignition delay, the injection FL2
The main injection via 2 is into the counter-moving air.

Therefore, the fuel and combustion air are mixed quickly in terms of time, and the air near the cylinder liner is sent opposite to the fuel injection flow from the injection holes 22.

If sufficient oxygen is present, a complete combustion at full load and a shortened combustion time are achieved by the invention, such that in the case of a small ignition delay, the combustion of the fuel will begin immediately after leaving the injection hole. Ru.

In order to harmonize a number of fuel injectors to the same delivery rate, a damping piston 58 with a spring 68 serves, the initial spring force of which can be adjusted as required from the outside via a suppression spindle 69. .

Through this, the internal pressure of the outer bore 45, which is varied, and the counterpressure for the overflow bores 48 and 49, it is possible to influence within a certain range the temporal movement profile of the spindle 150.

The pressure created in the lower section of the large eccentric hole 53: the bar 54 causes the damping piston 58 to move upward against the spring pressure of the spring 68.

During this movement, the damping piston 58 moves away from the inclined surface γ4 of the lower part of the guide bush 5γ, and thus the damping piston 58
The flow path of leaked fuel from the hollow chamber 8 to the ring-shaped hollow chamber 60 via the overflow hole 63 and the annular chamber 64 is opened.

If the lower region 54 of the large eccentric bore 53 is only partially filled with leaking fuel, the pressure in the ring-shaped hollow chamber 60 will be great and the ring-shaped idler valve 56 will spring out.
Since the valve opens against the splash pressure of 5, leaked fuel can penetrate into the lower region 54 of the large eccentric hole 53 and thereby fill this lower region 54.

However, if this lower region is full of leaking fuel, no trailing flow of leaking fuel will occur.

This is because the pressure in said lower region 54 is greater than the pressure in the ring-shaped cavity 60 and the ring-shaped reverse IL valve 56 cannot open.

Via the annular check valve 56, the leakage losses of the fuel present in the outer bore 45 and the annular chamber 28 are thus channeled back again, so that the outer bore 45 and the annular chamber 28 are completely filled again after the fuel injection. It will be done.

This is necessary because the annular chamber 28 must always be filled with leaking fuel.

Otherwise, sufficient braking of the brake piston 26 will not occur.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of the lower part of the injection valve according to the invention, FIG. 2 is a longitudinal sectional view of the upper part of the injection valve shown in FIG. 1, FIG. 3 is a schematic diagram of the combustion chamber, and FIG. The figure is a sectional view taken along the line IV-IV in FIG. 1. 1... Injection valve, 2... Threaded sleeve, 3... Lower part of injection valve casing, 4...
... Combustion chamber, 5 ... Inner wall, 6 ... Female thread, γ ... Upper part of injection valve casing, 8 ...
...Opening, 9...Outer wall, 10...
Lower range, 11... Ring-shaped diagonal chamfered part,
12... Slope part, 13... Concavity, 13
...Injection hole holder, 15...Spindle, 16...Spindle head, 1γ...-
...Additional part, 18...Fuel front chamber, 19.20.
... Inclined seating surface, 21, 22 ... Injection, hole, 23° 24 ... Center hole, 25 ... Ring-shaped additional part, 26 ... ...Brake piston, 2γ・
... lower edge, 28 ... annular chamber, 29 ...
... Tightening ring member, 30 ... Center hole, 31
...Guide member, 32...Spring, 33...
... Sleeve, 34 ... Spacer sleeve, 35 ... Lower range, 36 ... Inclined surface, 3γ ... Upper range, 38 ... ...Ring-shaped raised part, 39...Additional part, 40...Ball bearing, 41...Nut, 42...Screw thread, 43... ... Seal sleeve, 44, 45...
...outer hole, 46...hole, 4γ...
・Relatively large hole, 48.49...Relatively small overflow hole, 50...hole, 51...
... Upper range, 52 ... Overflow one hole,
53...Large eccentric hole, 54...Lower range, 55...Spring, 56...Ring-shaped check valve, 5γ... Guide bush, 58...
...Buffer piston, 59...Ring-shaped edge,
60... Ring-shaped hollow chamber, 61... Internal hole, 62... Small diameter blind hole, 63... Overflow hole, 64... ...Annular chamber, 65...
...The spring holder is a plate, 66.6γ...Protrusion part, 6
8... Spring, 69... Pressing spindle,
rO...Screw, γ1...Piston, γ
2... Piston top surface, γ3... Throttle gap, γ4... Inclined surface.

Claims (1)

[Claims] 1. An injection valve for an internal combustion engine of a reciprocating piston type equipped with a hollow cylindrical injection hole holder having at least two rows of injection holes communicating with the outside and located above and below, the injection hole holder being connected to the A seating surface is provided below the injection hole, and a seating surface corresponding to the seating surface is formed in the lower part of the injection valve casing. The injection hole holder 14 is located in a recess of the injection valve casing that closes the injection hole and is moved to the injection hole open position by the load of the fuel supply pressure, and the injection hole holder 14 is formed by one sleeve, The sleeve is attached to the spindle 1 in which the return spring 32 is engaged.
5 is loosely mounted on the sleeve and is kept in contact with the corresponding seating surface 21 of the lower part 3 of the injection valve casing by the spindle head 16 in the non-operating position, and the injection hole 21 in the sleeve, 22 is disposed to extend substantially tangentially to the inner wall of the sleeve.