JPH051570A - Boost compensator of fuel injection pump governor in engine with turbocharger - Google Patents

Abstract

PURPOSE:To improve two tuning items conflicting with each other on a torque characteristic and smoke performance or the like simultaneously by installing two-staged springs which impresses energizing force on a diaphragm at a specified mode as an energizing means for energizing the diaphragm, partitioning off a pressurizing chamber being interconnected to an intake passage. CONSTITUTION:In an interval between a flange part 8 of a tubular member 7 and a receiving member 9, there is provided a first stage spring 10a which energizes a diaphragm 6 to the side of a pressurizing chamber 4 and starting its contraction at a time when boost pressure becomes more than the first setting value. In addition, a second stage spring 10b is installed in an interval between the flange part 8 and a keeping member 23, whose movement to the side of the diaphragm 6 is restricted by a stopper 22 screwed on an outer circumference of the tubular member 7 in parallel together with the spring 10a. After the boost pressure goes up and the spring 10a goes up as far as the required length L1, the receiving member 9 is engaged with the keeping member 23, and contraction of the two-stage spring 10b is started at a time when the boost pressure has come to more than a second setting position, thus the position of a control rack 16 is made settable to two stages.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boost compensator for a fuel injection pump governor in a turbocharged engine.

[0002]

2. Description of the Related Art Generally, a fuel injection pump for a turbocharged engine is equipped with a boost compensator together with a governor for controlling the fuel injection amount according to the engine speed. When the amount of intake air sent increases, a proper amount of fuel commensurate with the increase is injected to achieve complete combustion and increased output.

As shown in FIG. 4, a conventional boost compensator 1 has a casing 3 installed on a governor 2 (to be described later) of a fuel injection pump, and communicates the inside of the casing 3 with an intake manifold (not shown). A diaphragm 6 for partitioning the pressurizing chamber 4 and the non-pressurizing chamber 5 is provided, and a flange portion 8 of a tubular member 7 disposed in the non-pressurizing chamber 5 and a receiving member 9 fixed to the diaphragm 6 are provided. A spring 10 for urging the diaphragm toward the pressurizing chamber 4 is interposed between the adjusting rod 11 and the adjusting rod 11 which has one end integrally formed with the receiving member 9 and the other end extending through the tubular member 7. In addition, a full load stop cam 13 having a cam portion 12 of a required shape for setting the upper limit of the fuel injection amount according to the engine speed is attached via a slide block 14. , Constitute a governor 2. Fly weight 15 that opens and closes by centrifugal force according to engine speed
And a tip of a floating lever 17 that connects the fuel injection amount control rack 16 via links 18 and 19 to the cam portion 12 of the full load stop cam 13 at all times by the urging force of a spring (not shown). It is designed to engage.

In the figure, 20 is an adjusting screw for adjusting the stroke end of the adjusting rod 11, and 21 is a spring for preventing the adjusting rod 11 from rattling.

As the engine speed increases in FIG. 4, the flyweight 15 opens outward from a solid line state to an imaginary line state against the urging force of a governor spring (not shown) by centrifugal force. The movement is transmitted to the floating lever 17 via the link 18, and the floating lever 17 is connected to the cam portion 1 of the full load stop cam 13.
By moving upward in accordance with 2, the control rack 16 is pulled back to the right in the figure via the link 19,
The fuel injection amount is reduced and the engine speed is controlled so as not to exceed a preset maximum speed.

On the other hand, the pressure (boost pressure) in the intake manifold (not shown) is introduced into the pressurizing chamber of the boost compensator 1, and when the boost pressure exceeds the set load of the spring 10, the diaphragm 6 and the receiving member. 9
The adjusting rod 11 moves leftward in the drawing together with the slide block 14 and the full load stop cam 13 also moves leftward in the drawing, so that the position of the floating lever 17 is displaced accordingly, and the control rack is moved. 16 moves to the left in the figure, and the fuel injection amount is increased by an amount corresponding to the boost pressure.

[0007]

However, in the case of the conventional boost compensator 1 as described above, the position of the full load stop cam 13, that is, the control rack 16 is controlled by only one spring 10 with respect to the boost pressure.
Since the position of (fuel injection amount) is controlled,
The relationship between the boost pressure and the position of the control rack 16 is expressed as shown in FIG. 5, and the relationship between the engine speed (the maximum speed is expressed as 100%) and the position of the control rack 16 is expressed in FIG. As described above, the pattern at full load steady state such as when climbing a slope is I, and the pattern at start is I
As shown in I, the idling pattern is represented as III, and the upper right sloping portion in each of the patterns I, II, and III corresponds to the process in which the boost pressure in FIG. 5 rises from P ₁ to P ₂ . In FIG. 6, in the full load steady state pattern I such as when climbing a slope, the area A has an excessive injection amount (= black smoke large), and in the starting pattern II, the area B has an insufficient injection amount (= insufficient torque). Further, in the idle blow pattern III, the region C may have an excessive injection amount (= black smoke large).

Further, the torque characteristic and the smoke performance are mutually contradictory tuning items. Particularly, in the case of an engine with a turbocharger, the zone of establishment of the torque characteristic and the smoke performance during a transition is extremely narrow, and among the above I, II and III. In general, improving the smoke performance and sacrificing the torque characteristic are often performed because an attempt to improve one of the patterns sacrifices the other patterns.

In view of the above situation, the present invention aims to provide a boost compensator for a fuel injection pump governor in an engine with a turbocharger that can simultaneously improve contradictory tuning items such as torque characteristics and smoke performance.

[0010]

SUMMARY OF THE INVENTION According to the present invention, a diaphragm for partitioning a casing into a pressurized chamber and a non-pressurized chamber communicating with an intake manifold, and a diaphragm urging the diaphragm toward a pressurized chamber via a receiving member. And a first-stage spring that starts to deform when the boost pressure becomes equal to or higher than a first set value, and the first-stage spring that is provided in parallel with the first-stage spring The second stage spring, which is pressed by the second stage spring and starts to deform when the boost pressure becomes equal to or higher than a second set value and is deformed together with the first stage spring, and one end of which is connected to the diaphragm via the receiving member. A floating lever that connects an adjusting rod that interlocks with the diaphragm, a flyweight that opens and closes according to the engine speed, and a control rack for adjusting the fuel injection amount. A full-load stop cam integrally provided at the other end of the adjusting rod, having a cam portion whose tip engages and sets an upper limit of the fuel injection amount according to the engine speed. To do.

[0011]

Therefore, when the boost pressure rises and the pressure in the pressurizing chamber becomes equal to or higher than the first set value, first, the first-stage spring biased through the diaphragm receiving member is deformed, so that the adjusting rod and When the full load stop cam moves integrally in the direction of increasing the fuel injection amount, the boost pressure rises and the first-stage spring deforms by the required amount, the diaphragm is in a state of pushing the second-stage spring via the receiving member. From the state, the second stage spring does not deform until the boost pressure further rises and reaches the second set value, and when it exceeds the second set value, the second stage spring starts to deform and deforms together with the first stage spring. The load stop cam moves in the direction of increasing the fuel injection amount.

[0012]

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

FIG. 1 shows an embodiment of the present invention. In the figure, the parts having the same reference numerals as those in FIG. 4 represent the same parts, and the parts between the flange part 8 of the tubular member 7 and the receiving member 9 are shown. Is provided with a first-stage spring 10a that urges the diaphragm 6 toward the pressurizing chamber 4 and starts contracting when the boost pressure exceeds a first set value P ₁ '(see FIG. 2). The tubular member 7 is fitted to the outer periphery of the portion 8 and the tubular member 7 so as to be movable in the axial direction thereof, and is moved toward the diaphragm 6 side.
The second step spring 10b is provided in parallel with the first step spring 10a between the pressing member 23 which is restricted by the stopper 22 screwed on the outer periphery, and the boost pressure is increased to require the first step spring 10a. After contracting by the amount L ₁ , when the receiving member 9 engages with the pressing member 23 and the boost pressure becomes equal to or higher than the second set value P ₃ ′ (see FIG. 2), the second spring 10b contracts. Start and adjust screw 2
It is made possible to shrink by the amount obtained by subtracting the above L ₁ from L ₂ set appropriately by 0.

With the configuration as described above, when the boost pressure rises and becomes equal to or higher than the first set value P ₁ 'as shown in FIG.
First, the first-stage spring 10a shown in FIG. 1 contracts, the full load stop cam 13 moves integrally with the adjusting rod 11 and the slide block 14 in the fuel injection amount increasing direction (left in FIG. 1), and the boost pressure is increased. Reaches P ₂ ', the first-stage spring 10a contracts by L ₁ and the receiving member 9 engages with the pressing member 23.

From this state, until the boost pressure further increases and reaches the second set value P ₃ ', the second stage spring 10
b does not contract, and when it becomes the second set value P ₃ 'or more, it starts contracting, and the full load stop cam 13 moves in the fuel injection amount increasing direction.

When the boost pressure reaches P ₄ ', the tip of the adjusting rod 11 comes into contact with the adjusting screw 20, so that the full load stop cam 13 moves in the fuel injection amount increasing direction even if the boost pressure further increases. Cannot be moved and the engine speed is controlled so as not to exceed the maximum speed.

As a result, as shown in FIG. 2, the position of the control rack 16 with respect to the boost pressure can be set in two stages, and as shown in FIG. 3, it is excessive in the full load steady-state pattern I'such as when climbing a slope. Injection can be avoided, black smoke can be reduced, torque shortage that should secure the injection amount necessary for start can be eliminated in start-up pattern II ′, and full load steady-state pattern in idle-driving pattern III ′ As with I ', over-injection can be avoided to reduce black smoke.

In this way, it is possible to simultaneously improve the torque characteristics and smoke performance, which are mutually opposing tuning items.

The boost compensator for the fuel injection pump governor in the engine with a turbocharger according to the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the scope of the present invention. Of course.

[0020]

As described above, according to the boost compensator of the fuel injection pump governor in the engine with a turbocharger of the present invention, it is possible to simultaneously improve contradictory tuning items such as torque characteristics and smoke performance. Can be played.

[Brief description of drawings]

FIG. 1 is a side sectional view of an embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between boost pressure and control rack position in an embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between an engine speed and a control rack position in one embodiment of the present invention.

FIG. 4 is a side sectional view of a conventional example.

FIG. 5 is a diagram showing the relationship between boost pressure and control rack position in a conventional example.

FIG. 6 is a diagram showing a relationship between an engine speed and a control rack position in a conventional example.

[Explanation of symbols]

1 boost compensator 3 casing 4 pressurizing chamber 5 non-pressurizing chamber 6 diaphragm 9 receiving member 10a first stage spring 10b second stage spring 11 adjusting rod 12 cam portion 13 full load stop cam 15 fly weight 16 control rack 17 floating lever P ₁ 'First set value P ₃ ' Second set value

Claims (1)

Claim: What is claimed is: 1. A diaphragm for partitioning the interior of the casing into a pressurized chamber and a non-pressurized chamber that communicate with the intake manifold; and a biasing member for biasing the diaphragm toward the pressurized chamber via a receiving member. A first-stage spring that starts to deform when the boost pressure becomes equal to or higher than a first set value and a first-stage spring that is provided in parallel with the first-stage spring are deformed by a required amount and then pushed by the receiving member. And a second stage spring that starts to deform when the boost pressure becomes equal to or higher than a second set value and is deformed together with the first stage spring, and one end of the diaphragm is connected to the diaphragm via the receiving member. The tip of the floating lever that connects the adjusting rod that works with the engine, the flyweight that opens and closes according to the engine speed, and the control rack for adjusting the fuel injection amount. A turbo equipped with a full load stop cam which is engaged with and has an upper limit of the fuel injection amount according to the engine speed and which is integrally provided at the other end of the adjusting rod. Boost compensator for the fuel injection pump governor in the engine with a charger.