JPS5936660Y2 - Fuel rack control device for exhaust turbocharged engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a fuel rack control device for an exhaust turbocharged engine.

A conventional device of this type is shown in FIG.

In the figure, 01 is a fuel rack, 02 is a rack stopper that contacts the end face of the fuel rack o1, and controls the maximum position of the fuel rack o1, and 03 is an arm, which is a part 02.
．． 03 constitutes a fuel rack stopper member.

o4 is a pivot point of arm 03 supported by a fixed wall,
o5 is a shaft that rotates arm 03 between pivot points;
o6 is a spring, 07 is a diaphragm, and pressure chamber 08
is displaced according to the pressure of the spring 06 and the force of the spring 06, and the displacement is transmitted to the shaft 05.

09 is a maximum shaft stopper that determines the maximum position of the displacement of the shaft 05 on the fuel increasing side, and 010 is a minimum shaft stopper that determines the minimum position of the displacement of the shaft 05 on the fuel decreasing side.

011 is a pressure vibrator that connects the air supply manifold 023 and the pressure chamber 08.

FIG. 2 shows the position of the rack stopper 02 with respect to the supply pressure P.

When the pressure in the air supply manifold 023 is lower than a certain pressure Pbl, the shaft 05 is pressed against the minimum stopper 010 by the force of the spring 06, and the rack stopper 02 is at the position xRcl.

When the supply pressure P becomes higher than the pressure Pbl as the engine speed increases, the shaft 05 is displaced against the force of the spring 06 due to the pressure in the pressure chamber 08 applied to the diaphragm 07, and the position of the rack stopper 02 becomes XRC1. increase more.

Further, when the supply pressure P becomes higher than a certain pressure Pb2, the shaft 05 is pressed against the maximum stopper 09 by the pressure applied to the diaphragm 07, and the position of the rack stopper 02 reaches a ceiling at "RC2".

The solid line in Figure 3 represents the engine performance at full acceleration at the rotation speed NE.
shown against.

When the engine speed NE decreases, the supply pressure P decreases,
Rack position R6” because the amount of air supplied to the engine is reduced.
``If RC2 (constant) remains, the smoke density R will increase, but
When the supply pressure P, becomes lower than the pressure P,2, the rack stopper position becomes smaller and the amount of fuel supplied to the engine decreases.

For this reason, although the engine torque T decreases, the emitted smoke concentration R is not intentionally increased.

Figure 4 shows two exhaust turbo superchargers installed in order to increase the torque in the low speed range of an exhaust turbocharged engine, and one of them is cut in the low speed range to reduce the capacity of the supercharger. do,
This is an engine designed to increase air supply pressure.

In the figure, olol is the engine body, o1o2 is the exhaust manifold, 0103 is the air supply manifold, 0104°010
5 is an exhaust turbo supercharger, 0106 is an exhaust cut valve, 01
07 is an air supply cut valve, and 0108 is an exhaust bypass valve. When the exhaust turbo supercharger 0105 is cut off by the exhaust cut valve 0106 and the air supply cut valve 0107, the engine speed increases and the air supply is cut off. In order to prevent the pressure from rising excessively, the exhaust bypass valve 108 is opened in response to the boost pressure signal 109, and a portion of the exhaust gas is released to the atmosphere.

The engine performance when a conventional fuel rack control device is installed on the improved engine as described above is shown in Figure 3.
Indicated by broken lines in the figure.

The solid line is the case when two units are operated.

When one car is cut, at the same rotational speed NE, since the supply pressure P is high, the rotational speed N at which the supply pressure P becomes lower than the pressure Pb2 and the rack stopper 02 changes to the low fuel position.
E□ is lower than the rotation speed NE■ in the case of two engines, and at the same rotation speed NE, when one engine is cut, a correspondingly larger amount of fuel is input to the engine, so the torque T increases (
The portion indicated by the arrow A in Fig. 3)C Fig. 5 shows the fuel injection amount with respect to the rotational speed NE when the fuel rack position is constant.

In the low engine speed range, the injection amount per cycle decreases as the rotational speed NE decreases.

Therefore, at the rotational speeds NE1 and NEn in FIG. 3, even though the supply pressure P is the same, the fuel injection amount at NE□ is smaller, and the smoke density R is correspondingly lower.

That is, if one unit is cut, there is room to further increase the torque T by moving the fuel rack in the fuel increasing direction within the same smoke concentration limit condition.

From the above, it can be seen that when the conventional fuel rack control device is installed in an engine with a variable exhaust turbocharger capacity, the torque increase in the low speed range is not sufficiently measured.

The purpose of this invention is to increase the torque in the low speed range in an engine with variable exhaust turbo supercharger capacity, that is, in an exhaust turbo supercharged engine in which one of the turbochargers can be cut. The purpose of the present invention is to provide a fuel rack control device that can realize the following to the maximum extent possible.

In a conventional fuel rack control device in which fuel increases as the supply pressure increases, (1) a second pressure chamber that moves the pivot point of the fuel rack stopper member so that the fuel decreases as the supply pressure increases;
(2) The pressure led to this second pressure chamber is the supply pressure when one turbocharger is cut, and the high pressure when two turbochargers are operating. The reason is that a switching valve that can be used to control the air tank pressure is provided.

As a result, maximum torque can be obtained within the smoke concentration limit conditions when one supercharger is operated.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 6 is an explanatory diagram showing the cross section and structure of a fuel rack control device according to an embodiment of the present invention.

In the figure, 1 is a fuel rack, 2 is a part that comes into contact with the end surface of the fuel rack 1, that is, a rack stopper, which limits the maximum position of the fuel rack 1, 3 is an arm, and parts 2 and 3 are parts that stop the fuel rack stopper member. Configure.

4 is a pivot point of the arm 3, and 5 is a shaft, which rotates the arm 3 around the pivot point 4.

A spring 6 acts against the movement of the shaft 5 in the direction of fuel increase.

A diaphragm 7 is displaced in the direction of fuel increase as the pressure in the pressure chamber 8 increases, according to the force of the spring 6, and transmits the displacement to the shaft 5.

A maximum shaft stopper 9 determines the maximum position of the displacement of the shaft 5 on the fuel increasing side.

A minimum shaft stopper 10 determines the minimum position of the displacement of the shaft 5 on the fuel depletion side.

11 is a pressure vibrator that connects the air supply manifold 23 and the pressure chamber 8.

Reference numeral 12 denotes a second shaft, which is connected to the arm 3 at a pivot point 4 located in the middle thereof, and by changing its position, the rack stopper 2 can be displaced.

Reference numeral 13 denotes a second spring that acts against the movement of the second shaft 12 in the direction of fuel depletion.

Reference numeral 14 denotes a second diaphragm, which is displaced in the direction of decreasing fuel as the pressure in the second pressure chamber 15 increases, according to the force of the second spring 13, and transmits the displacement to the second shaft 12.

A second maximum shaft stopper 16 determines the maximum position of the displacement of the second shaft 12 on the fuel increasing side.

A second minimum shaft stopper 17 determines the minimum position of the displacement of the second shaft 12 on the fuel depletion side.

A second pressure vibrator 18 communicates the second pressure chamber 15 with either the high-pressure air tank 22 or the air supply manifold via a switching valve 19.

The switching valve 19 connects one of the engine's superchargers to the exhaust cut valve 01.
06 and the supply air cut valve 0107, the second pressure chamber 15 and the supply air manifold 23 communicate with each other.
Switching is controlled by a control device (not shown) so that the second pressure chamber 15 and the high-pressure air tank 22 communicate with each other when the supercharger is not completely cut off.

The effect in the case of the tank bottom described above will be described.

FIG. 7 shows changes in the position of the rack stopper 2 with respect to the supply pressure P.

The solid line indicates communication between the high pressure air tank 22 and the second pressure chamber 15 via the switching valve 19, and the broken line indicates communication between the air supply manifold 2
3 and the second pressure chamber 15 are communicating with each other.

When the high-pressure air tank 22 indicated by the solid line and the second pressure chamber 15 are in communication, the pressure of the high-pressure air tank 22 causes the second
The diaphragm 14 is displaced against the second spring 13, the second shaft 12 is pressed against the second minimum shaft stopper 17, and the pivot point 4 is at the low fuel position.

In this state, when the supply pressure P changes, the pressure in the pressure chamber 8 changes and the shaft 5 is displaced by the action of the diaphragm 7 and spring 6, and the position of the rack stopper 2 is changed as shown by the solid line in FIG. , when the supply pressure P, is lower than Pbl, it is at the position xRc1 determined by the minimum shaft stopper 10, and when the pressure rises above P,1, the supply pressure P,
When the supply pressure becomes higher than the pressure Pb2,
The position xRc2 is determined by the maximum shaft stopper 9.

Next, when the air supply manifold 23 indicated by the broken line and the second pressure chamber 15 are in communication, the pressure in the second pressure chamber 15 received by the second diaphragm 14 is lower than the force of the second spring 13. At this time, the second shaft 12 is pressed against the second maximum shaft stopper 16, and the pivot point 4 is at the fuel increase position.

In this state, when the supply pressure Pb increases, (a)
First, when the supply pressure P is lower than Pb1, the shaft 5 is pressed against the minimum shaft stopper 10 as before, but since the pivot point 4 is at the fuel increase position, the shaft 5 is pressed against the minimum shaft stopper 10 as before.
As shown by the broken line in the figure, the amount △ corresponds to the displacement amount of the pivot point 4.
The position xRc of the rack stopper 2 increases by xRC.

(b) As the supply pressure P further increases from pressure Pb□ to Pb2, the rack stopper position xRC changes from the rack stopper position when the second pressure chamber 15 is in communication with the high pressure air tank 22. △xR than the change in RC
When c increases, it changes as shown by the broken line.

(c) When the supply pressure P further increases and becomes higher than the pressure pba at which the second shaft 12 determined by the second spring 13 and the second diaphragm 14 starts to be displaced, the pivot point 4 moves in the direction of fuel decrease. and the second shaft 1
2 presses against the second minimum shaft stopper 17.
The rack stopper 2 is displaced by ΔXRC in the direction of fuel reduction, and finally reaches the same position as the solid line xRC2.

In the above explanation, the rack positions xRCI and xRC2 can be determined by the minimum shaft stopper 10, maximum shaft stopper 9, and second minimum shaft stopper 17, respectively, and △"RC can be determined by the second maximum shaft stopper 16. It will be done.

Further, the pressures P, 1 and Pb2 are determined by the spring 6 and the diaphragm 7, and the pressure Pb3 is determined by the second spring 13 and the second diaphragm 14.

Further, the pressure of the high-pressure air tank 22 is maintained at a pressure Pb3 or higher.

The present invention as described above has the following effects.

Fig. 8 shows the present embodiment as shown in Fig. 4, which is equipped with an engine with variable exhaust turbo supercharger capacity, for example, two superchargers, one of which can be cut off by a switching valve. Indicates engine performance at full acceleration when applied to an engine.

The solid line indicates when two superchargers are in operation, and the broken line indicates when one supercharger is cut.

When two turbochargers are used, by communicating the second pressure chamber 15 and the high pressure air tank 22 with the switching valve 19, the rack position R6 is set to the conventional position as shown by the solid line in FIG. 8 along with the rotation speed NE. Like an engine, it operates at the limit of smoke density R at low speeds.

At high speeds, of course, it operates as before.

If one of the turbochargers is cut, the switching valve 19 connects the second pressure chamber 15 and the air supply manifold 23, as shown by the broken line in FIG. With respect to the atmospheric pressure P5□, the rack position increases by △''RC, so the torque relative to the rotational speed increases greatly, and the torque that is at the limit of the smoke concentration can be obtained.

In addition, when the rotational speed increases and the supply pressure P starts to reach a ceiling due to the operation of an exhaust bypass valve or the like to prevent the supply pressure P from rising excessively, the second shaft 12 moves in the direction of fuel reduction. By starting to move, it is possible to prevent the smoke concentration from becoming excessive in the high speed range as shown by the dashed line in FIG.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing a fuel rack control device for a conventional exhaust turbocharged engine, Fig. 2 is a diagram showing changes in the position of the rack stopper with respect to supply pressure, and Fig. 3 shows engine performance with respect to rotation speed. Figure 4 is an explanatory diagram showing a supercharged engine equipped with two exhaust turbo superchargers and one of which can be cut, and Figure 5 shows the change in fuel injection amount per cycle with respect to rotation speed. 6 is an explanatory diagram showing the cross section and configuration of a fuel rack control device according to an embodiment of the present invention, and FIG. 7 is a diagram showing changes in the position of the rack stopper with respect to the supply pressure of the device in FIG. 6. , FIG. 8 is a graph showing engine performance versus rotational speed when the device shown in FIG. 6 is installed in a supercharged engine equipped with two exhaust turbo superchargers, one of which can be cut. 1...Fuel rack, 2...Rank stopper, 3...Arm, 4...Pivot point,
5...Shaft, 6...Spring,
7...Diaphragm, 8...Pressure chamber,
9, 10... Shaft stopper, 11...
...Pressure vibe, 12...Second shaft, 1
3...Second spring, 14...Second diaphragm, 15...Second pressure chamber, 1
6.17...Second shaft stopper, 18.
...Second pressure vibrator, 19...Switching valve, 22...High pressure air tank, 23...
Air supply manifold.

Claims (1)

[Scope of utility model registration request] A plurality of turbochargers capable of cut operation, a pressure chamber defined by a diaphragm in the case, and a spring energized by the pressure of supply air introduced into the pressure chamber from the turbocharger. comprising a shaft member capable of reciprocating displacement against elasticity, and an arm member having one end connected to the shaft member, the other end capable of contacting the fuel rack, and having a pivot point at an intermediate portion, In the fuel rack control device configured to regulate the amount of movement of the fuel rack in the fuel increasing direction by the supply air pressure in the pressure chamber, a second
a second pressure chamber defined by a second diaphragm within the case; an air passage connecting the second pressure chamber to an air supply passage and an air source having a higher pressure than the air in the air supply passage; When the operation of a part of the turbocharger is cut, the supply air from the operating turbocharger is sent to the second pressure chamber, and when all the turbochargers are in operation, the supply air is supplied to the second pressure chamber. a switching valve that supplies air from an air source with a higher pressure than the pressure in the air passage to a second pressure chamber; and a second spring biased in the opposite direction, the second spring is caused to reciprocate and displace the pivot point of the arm member in the direction of fuel reduction when the air pressure increases. A fuel rack control device for an exhaust turbocharged engine, comprising a shaft member.