JPS6011673A - Fuel injection device - Google Patents

Abstract

PURPOSE:To enable the suitable injection of fuel to be continually performed, by providing a phase controller on the cam shaft of a rack cam, in the case of an injector metering the amount of fuel by rotating a plunger having a lead through a control rack. CONSTITUTION:If a cam shaft 57 rotates causing a plunger 13 having a metering lead 48 to rise in accordance with operation of an engine, fuel supplied to a port 52 is fed to a pump chamber 37 from a hole 38, next the plunger 13 lowers to close the hole 38, and then the fuel is compressed. The compressed fuel is fed to a fuel reservoir 27 via passages 54-56, and the fuel, after forcing a nozzle needle 12 to be lifted against a spring 31, is injected from nozzles 25, 26. Here a rack cam 17 is rotated through a phase controller 18 on the basis of a fuel injection pattern determined by a control unit 19 in accordance with the depressing amount of an accelerator pedal and a speed of the engine. In this way, the amount of fuel is adjusted by rotating the plunger 13 through a control rack 15.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a unit injector type fuel injection device used in a diesel engine.

Generally, unit injectors used in diesel engines are mounted directly on the diesel engine's cylinder head without using high-pressure injection pipes, and are driven by the diesel engine's camshaft.
They have been configured to inject fuel.

In such fuel injection, adjustment of the injection amount, so-called fuel metering, is performed by various means, and a typical example is the unit manufactured by General Motor Company in the United States.
Like an injector, a sylanger equipped with a reed is rotated by a control rack, and the effective stroke of the plunger is changed to adjust the amount of fuel injected.

However, in this type of unit injector, the control rack is connected to the governor via a link mechanism, so the link mechanism tends to rattle.
The metering of fuel becomes unstable, which may cause surging or hunting, especially during idling or low-speed operation.

The purpose of this invention is to stabilize the metering of fuel, obtain a desirable fuel injection amount and injection timing, and further improve the fuel consumption rate. An object of the present invention is to provide a fuel injection device that reduces the occurrence of.

In order to solve these problems, the fuel injection device of the present invention arranges a plunger equipped with a reed in a plunger bore of a pump body so as to be able to reciprocate and rotate.The plunger is rotated by a control rack. The pump body and the month so that the rack cam moves the control rack to meter the injected fuel by changing the effective stroke? The phase controller is arranged somewhere near the pump body, and the phase controller is connected to the cam shaft of the rack cam.

Hereinafter, preferred specific examples of the fuel injection device according to the present invention will be described with reference to the drawings.

Figures 1 and 2 show a 10 specific example of the fuel injection device of the present invention applied to a diesel engine mounted on a truck.
It shows.

r 3 ) This fuel injection device 10 has a plunger 13 equipped with a lead 48 disposed in a plunger bore 36 of a pump body 11 so as to be able to reciprocate and rotate, and the plunger 13 is rotated by a control rack 15. The unit injector type is configured to adjust the amount of fuel injected by changing the effective stroke of the sylanger 13, and is positioned near the pump body 11 so that the rack cam 17 moves the control rack 15. The layout is chaotic and
The phase controller 18 controls the cam of the rack cam 17.
It is configured to be connected to the shaft 16.

That is, the fuel injection device 10 has a valve seat 2
4 and a plurality of nozzles 25, 26e; a pump body 11 having a plunger bore 36 connected to a fuel reservoir 27 of the needle spindle bore 23; and a pressure spring 31.
so that the valve seat 24 is seated by
The nozzle needle 12 is fitted into the needle spindle bore 23 and the plunger bore is arranged to form a pumping chamber 37 in the plunger bore 36 at the side end of the needle spindle bore 23. a plunger 13 having a lead 48 reciprocally slidably and rotatably disposed on the pump body 36 and in communication with the pumping chamber 37; a plunger pinion 14 fitted to the plunger 13 so as to
A control is engaged with the sylanger pinion 14 and is reciprocably disposed on the pump body 11 so as to rotate the sylanger pinion 14.
It is composed of a rack 15, a rack cam 17 placed near the pump body 11 so as to move the control rack 15, and a phase controller 18 connected to the camshaft 16 of the rack cam 17. has been done.

(5) The pump body 11 includes a valve seat 24 and a needle spindle bore 23 having a plurality of nozzles 25 and 26.
, the plunger bore 36, which is connected to the fuel reservoir I) 27 of the needle spindle bore 23 via pressure canals 54, 55, 56, in a position remote from the sononeedle spindle bore 23.
A pinion bore 42 which is partially and concentrically widened from the diameter 36, and a rack guide connected perpendicularly to one side of the circumferential surface of the pinion bore 42 form a 43. We are prepared.

To describe the configuration of the pump body 11 in more detail, the pump body 11 includes a nozzle 22, a pressure spooling guide 28,
, a partition plate 34, a plunger barrel 35, and a plunger guide 39, and the nozzle 22, pressure spring guide 28, partition sill plate 34, and plunger barrel 35 are assembled to the plunger guide 39 with a nut 50. There is.

The nozzle 22 is provided with a valve seat 24 and (6) a plurality of nozzles 25, 26' (with a needle spindle bore 23), which is cooperated with the nozzle needle 12 to be described below and whose needle spindle・Boa 2
A pressure canal 54 is provided which is connected to a fuel reservoir 27 formed at 3.

The pressure spring guide 28 defines a pressure spring chamber 29 which is generally coaxially aligned with the needle spindle bore 23 when assembled with the nozzle 22 into the planter guide 39 at the end 50. A bottle hole 32 is formed at the lower end, and the upper end of the pressure spring chamber 29 is open. A pressure spring 31 and a spring seat 3° are arranged in the pressure spring chamber 29 so formed.

Also, the pressure spring guide 28 is connected to the nozzle 22
A pressure canal 55 is provided which is connected to a pressure canal 54 of.

When the partition plate 34 is assembled to the plunger guide 39 with the nozzle 22, pressure spring guide 28, and plunger barrel 35 by means of the nut 50, the pressure spring f IJ song chamber 2
Close the opened upper end of No. 9. Furthermore, the partition plate 34 is provided with a pressure canal 56 which is communicated with the pressure canal 55 of the pressure spring guide 28 .

The plunger barrel 35, together with the nozzle 22, pressure spring guide 28, and partition plate 34, forms a plunger bore 36 above the partition plate 34 when assembled to the plunger guide 39 by means of the nut 50.

Further, the plunger barrel 35 is provided with a feed and spill hole 38 at a predetermined position below, and when assembled to the plunger guide 39 with the nut 50, the feed and spill hole 38 is opened. It is connected via a gearing 51 to a feed and spill port 52 formed in its nut 50.

The plunger guide 39 includes a follower guide bore 41 opened at the upper end, and a follower guide bore 41 that is open at the upper end.
A binion bore 42 concentrically widened downward, a barrel bore 40 formed concentrically below the binion bore 42 and into which the upper portion of the plunger barrel 35 is fitted, and The binion bore 42
The rack guide bore 43 is provided with a rack guide bore 43 orthogonally connected to one side of the inner circumferential surface of the rack. In addition, the plunger guide 39 forms an extension 44 on one side of the rack guide dere 43, as shown in FIG.

The nozzle needle 12 is fitted into its needle spindle bore 23 such that it is seated in its valve seat 24 by a pressure tin ring 31.

That is, its nozzle needle 12 coaxially projects a bottle 33 at its upper end, passing the bottle 33 through the bottle hole 32 of its pressure spring guide 28, and (9) inserting the spring disposed in its pressure spring chamber 29. - The tip of the bottle 33 is in contact with the valve seat 30 and is pressed against the valve seat 24 by a pressure spring 31 arranged in the pressure spring chamber 29.

The plunger 13 penetrates the binion dere 42,
Further, the plunger bore 36 is configured to form a pumping chamber 37 within the plunger pore 36 at the side end of the needle spindle pore 23 .
It is arranged so that it can reciprocate and rotate. Of course, the pumping chamber 37 is connected to the pressure canals 54,5.
5.56 through the needle spindle bore 2
It is connected to the fuel reservoir 27 of No. 3.

Further, the plunger 13 has a lead 48 formed on its outer peripheral surface at a predetermined position on the lower end side, and further forms a communication path 49 connecting the lead 48 to the pumping chamber 37 at the lower end portion. .

Furthermore, the plunger 13 has the binion (10
) A male straight spline 47 is formed on the outer peripheral surface of the portion located on the gear 42.

The plunger 13 is also connected at its upper end to a follower 20 which is slidably fitted to the follower guide 7 in the follower guide bore 41 in a reciprocating manner. Of course, the follower 20 is extended outside the plunger guide 39 and forms a flange at its extended end for the pumping spring 21.

The pimping spring 21 is made of a coil spring, and has both ends located between the flange 53 of the follower 20 and the spring seat 58 of the plunger guide 39, and has a follower portion projecting outward from the plunger guide 39. The rotation of a cam shaft 57 of a diesel engine mounted on the truck provides a reciprocating motion, that is, a pumping motion, to the planter I3.

The plunger pinion 14 is housed in the pinion bore 42 of the plunger guide 39 so as to be splined to the male straight spline 47 of the plunger 13.

The control rack 15 is reciprocally disposed in the rack guide bore 43 of the plunger guide 39 so as to mesh with the plunger pinion 14 thereof. Of course, one end of the control rack 15 projects outside the plunger guide 39 as a follower portion 59 that contacts the rack cam 17, which will be described later.

Also, on the opposite side of the follower portion 59, a plug 45 is screwed into the extension portion 44 of the plunger guide 39, and the other end of the control rack 15 connects the plug 45 with the other end of the control rack 15 within the rack guide bore 43. A rack frame 46 is arranged between them.

The rack spring 46 is a coil spring that pushes the control rack 15 to the right in FIG. 1 so that less fuel is metered. Of course, if the control rack 15 is moved to the left in the figure against the rack spring 46, the plunger 1 along with the plunger pinion 14
3 is rotated to change the relative position of the feed and spill hole 38 and its plunger I3 lead 48, metering more fuel.

Rack cam I7 moves its control rack I5, in other words its rack cam 17
The control rack 15 is rotatably disposed near the pump body 11 with its cam surface in contact with the follower portion 59 of the control rack 15.

Of course, the follower section 5 of the control rack 15
9 protrudes outside the plunger guide 39, so that the rack cam 17 is rotatably disposed near the pump body 11 and connected to the cylinder of the diesel engine via a suitable platen, for example. - Rotatably supported by the head.

The phase controller 18 is driven (13) in response to an output signal from the metering control unit 19. The stepper motor drives the cam shaft 16 of the rack cam 17 to rotate the rack cam 17. It is connected to the.

Further, the metering control unit 19 sends an output signal to the phase controller 18 according to the amount of depression of the accelerator pedal of the truck and the number of rotations of the diesel engine, and includes an input and output circuit, an arithmetic circuit, It consists of a memory circuit, a control circuit, and a power supply circuit.

Therefore, the input circuit includes accelerator, pedal, and sensor (
(not shown) and an engine speed sensor (not shown) are electrically connected to each other, and! , and the output circuit is electrically connected to the phase controller.

Although the above-mentioned phase controller 18 has been explained as a stepping motor, it may also be a servo motor, a hydraulic motor, etc.
The structure is arbitrary as long as the rack cam 17 can be rotated, and furthermore, the rack cam 17 can be rotated by the power of the diesel engine.
The cam shaft 57 of the diesel engine (14) and the cam shaft 16 of the rack cam 17 may be connected.

Of course, when configuring the phase controller 18 in this way, it is possible not only to change the phases of the input shaft and output shaft of the phase controller 18 arbitrarily, but also to provide a function to connect and disconnect the input shaft and output shaft, a so-called clutch. It is important to have functions.

The feed of the fuel injection device 10 configured as described above
Of course, the and spill port 52 is connected to a feed pump (not shown) via a fuel pipe.

Next, to describe the operation of the above-mentioned fuel injection device 10, if the diesel engine is currently in operation, fuel is transferred from the fuel tank by the feed pump to the feed and spill port 52 via the fuel pipe. Sent.

At the same time, the rotation of the cam shaft 57 of the diesel engine causes the plunger 13 to reciprocate within the plunger bore 36.

Of course, when the planter 13 rises, the fuel sent to the feed-and-spill O port 52 is pumped through the feed-and-spill hole 38.
The plunger 13 is sent into the chamber 37, and the plunger 13 lowers the feed and
When the spill hole 38 is closed, the pumping
The fuel within chamber 37 is compressed.

Therefore, the high-pressure fuel compressed in the pumping chamber 37 is sent to the fuel reservoir υ27 via the fuel canals 54, 55, 56, and further lifts the nozzle needle 12 against the pressure spring 31. Spout 25.2
6 to the cylinder chamber (not shown), and is injected at high pressure and in the new year.

A portion of the fuel in the first and second pumping chambers 37 is released to the feed and spill port 52 side through the communication passages 49 and υ to 48, thereby improving the sharpness of the fuel injection path.

In this way, high-pressure fuel injection takes place in this fuel injection device 10, but the metering of the injected fuel is done by a phase controller I8 under the control of a metering control unit 19.

That is, the metering control unit 19 inputs the amount of depression of the accelerator/wave pedal and the rotation speed of the diesel engine, and sends an output signal to the phase controller 18 based on a predetermined fuel injection pattern. Rack cam 17 is rotated by phase controller 18 . As the rack cam 17 is rotated, the control rack 15 is moved in response to the rotation of the rack cam 170, so that the plunger binion 1
Granger 13 rotates together with 4, and feeds and
Spill hole 38 and its lead 48 of plunger 13
The relative position of the diesel engine is changed, so that the fuel is always properly metered depending on the operating conditions of the diesel engine.

Further, in this fuel injection device 10, the phase controller 1
Since the control rack 15 is moved by the rotation of the rack cam 17 by the rotation of the rack cam 17 and the fuel is metered, there is less rattling (17 ), and the movement of the control rack 15 becomes smooth and proper.

According to this invention as mentioned above, the plants in the pump body are
The effective stroke of the plunger is changed by rotating the plunger in the bore with a control rack and changing the relative position of the plunger's IJ-head and the feed and spill hole; a cam is disposed on the pump body and a tilting member at a position near the pump body to move the control rack, and a phase controller is connected to the cam shaft of the rack cam to move the control rack. Since the control rack is configured to be moved by the rotation of the rack cam, the movement of the control rack is smooth and reliable, the metering of fuel is stabilized, and heavy fuel injection amount and injection are prevented. As a result, the fuel consumption rate is further improved, and the occurrence of surging and hunting is reduced, especially when the diesel engine is running at isle or at low speed.〇(18) As mentioned above, refer to the drawing. From the specific examples of the invention described above, it will be apparent that various modifications and changes will be easily made by those having ordinary knowledge in the technical field to which this invention pertains, and furthermore, The structure could easily be replaced by essentially the same embodiments of this invention, fulfilling essentially the same tasks and achieving the same effects as this invention.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a specific example of the fuel injection device of the present invention applied to a diesel engine mounted on a truck;
And, FIG. 2 is a schematic diagram showing the phase controller connected to the cam shaft of the rack cam in the fuel injection device of the present invention.
...Nozzle needle, 13...Plantsya, 14
・・Soran Tsuya Pinion, 15・・Control・
Rack, 16...Cam shaft, 17...Rack cam, 18...Phase controller, 36...F0
Landsja Der, 48...lead. Patent applicant Hino Motors Co., Ltd.

Claims (1)

[Claims] A sylanger with a lead is attached to a plunger of a pump body.
? The rack cam is arranged so as to be able to reciprocate and rotate within the syringe, and its plunger is rotated by a control rack to change the effective stroke of the syringe and meter the amount of fuel to be injected.・
A fuel injection device disposed at any of the pump body and a position near the pump body to move the rack, the phase controller being connected to the cam shaft of the rack cam. .