JPH0579431A - Fuel injection device - Google Patents

Abstract

PURPOSE:To increase fuel pressure which flows inside a fuel distribution pipe enable a fuel injection quantity to be increased so as to provide wilely applicable fuel supply characteristic by only a single fuel injection value by strengthening the spring force of the spring of a pressure regulator by means of a spring adjustment means. CONSTITUTION:A pressure regulator R is built up by being provided with a fuel chamber 72 and a pressure chamber 73 divided by a partitioning body 71 in a device which supplies pressurized fuel to a fuel injection valve via a fuel distribution pipe and adjusts the fuel pressure by the pressure regulator R provided on the fuel distribution pipe. A fuel flow-in passage 74 arranged next to the fuel distribution pipe, and a fuel flow-out passage 75 whose flow-out valve seat 76 on its opening end part is openly/closely controlled by a valve body 79 provided at the partitioning body 71 are opened to the fuel chamber 72. A pressure introduction passage 77 which communicates with an intake pipe is opened to a pressure chamber 73, and a spring 78 which energizes the partitioning body 71 to the side of the fuel chamber 72 is interposed. Spring force of the spring 78 can be adjusted by a spring force adjustment means K which includes an electromagnetic actuator 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention calculates the amount of fuel required for combustion of an engine based on an air amount signal detected directly or indirectly, and gives a valve opening signal to a fuel injection valve. The present invention relates to a fuel injection device in which fuel pressurized by a fuel pump is injected and supplied to an engine by opening a fuel injection valve.

[0002]

2. Description of the Related Art A fuel injection device is shown, for example, on pages 36 to 37 of "Electronic Control Gasoline Injection" (Sankaido Publishing). This will be described with reference to FIG.

T is a fuel source in which fuel is stored, and the fuel in the fuel source T is pressurized by a fuel pump P and connected to a fuel distribution pipe F. The pressurized fuel sent to the fuel distribution pipe F is injected and supplied to the engine E from a fuel injection valve J arranged in the fuel distribution pipe F.

On the other hand, the pressure of the fuel flowing through the fuel distribution pipe F is controlled by the pressure regulator R to be a constant fuel pressure, for example, 2.5 kg / cm 2. That is, the pressure of the fuel supplied to the fuel injection valve J is 2.5 kg / square centimeter.

The pressure regulator R will be described in more detail. The housing 70 is divided into a fuel chamber 72 and a pressure chamber 73 by a partition 71 such as a diaphragm.

In the fuel chamber 72, a fuel inflow path 74 connected to the fuel distribution pipe F, a fuel outflow path 75 connected to the fuel source T,
Opens. An outflow valve seat 76 is formed at the opening end of the fuel outflow passage 75 to the fuel chamber 72.

A pressure introducing passage 77 is opened in the pressure chamber 73 in the vicinity of the opening where the fuel injection valve F opens in an intake pipe (not shown) of the engine E. Furthermore, in the pressure chamber 73,
A spring 78, whose one end 78A is locked to the housing 70 and the other end 78B is locked to the partition 71, is contracted.
Pressed to the side.

Further, the valve body 7 is provided on the fuel chamber 72 side of the partition body 71.
9 are integrally arranged, and the valve body 79 opens and closes the outflow valve seat 76. When the fuel pump P is not driven, the valve body 79
Closes the outflow valve seat 76.

[0009]

The conventional fuel injection device has the following problems. The fuel injection amount of the fuel injection valve J is determined by the following equation. The fuel injection amount Q = the opening area S of the fuel injection valve J × the energization time Ti of the fuel injection valve J × the fuel pressure Pa supplied to the fuel injection valve J.

Considering the opening area S, the opening area S in the fuel injection valve is formed by the needle valve and the injection hole. Since the needle valve and the injection hole are fixedly determined, the opening area S is determined once. Then, the opening area S becomes constant.

Considering the energization time Ti, the fuel injection valve J is based on the signals of various sensors, and the ECU (Electronic Control) according to the operating state of the engine.
The output signal from the unit (Unit) is received, and the energization time Ti changes.

Considering the fuel pressure Pa, the fuel pressure supplied to the fuel injection valve J is a constant pressure (for example, 2.5) due to the pressure regulator R as described above.
(kg / square centimeter).

According to the above, the fuel injection amount Q injected by the fuel injection valve J is uniquely determined by the energization time Ti to the fuel injection valve J, that is, the valve opening time. An example of the relationship between the fuel injection amount Q and the energization time Ti is shown by the solid line in FIG.

Therefore, in order to match the fuel injection valve J whose fuel injection amount Q is uniquely determined by the energization time Ti to another fuel supply characteristic of another engine or other specification, a new opening area S having a different opening area S is required. It is necessary to prepare a large number of fuel injection valves J. According to this, the number of types of needle valves and injection holes becomes extremely large and the number of combinations thereof becomes enormous, and the production effect due to mass production decreases. In addition, the parts management becomes complicated, and the assembly management of the production becomes complicated.

The fuel injection device according to the present invention has been made in view of the above problems, and it is an object of the present invention to provide the device capable of obtaining a wide fuel supply characteristic with a single fuel injection valve.

[0016]

In order to achieve the above object, the present invention pressurizes fuel stored in a fuel source with a fuel pump, and injects the pressurized fuel into a fuel distribution pipe. A fuel regulator that supplies fuel to the engine through a valve and a pressure regulator that keeps the fuel pressure flowing in the fuel distribution pipe constant with respect to the intake pipe pressure near the injection opening of the fuel injection valve with respect to the intake pipe In the provided fuel injection device, the pressure regulator is divided into a fuel chamber and a pressure chamber by a partition body, and in the fuel chamber, a fuel inflow passage connected to the fuel distribution pipe and an opening to the fuel chamber connected to the fuel source. An outlet valve seat provided at an end is opened to a fuel outlet passage that is controlled to be opened and closed by a valve body that moves in synchronization with the partition body, and a pressure chamber is provided near the intake pipe where the fuel injection valve is opened. Open a continuous pressure introduction path And provided under compression spring which elastically presses the partition body to the fuel chamber side with, lock the spring force adjusting means at one end of the spring is obtained by variably adjusting the spring force of the spring during operation of the engine.

[0017]

When the spring force of the spring of the pressure regulator is increased by using the spring adjusting means, the pressure of the fuel flowing in the fuel distribution pipe can be increased, whereby the fuel injection amount injected from the fuel injection valve can be increased, On the other hand, if the spring force of the spring is weakened, the fuel injection amount can be reduced. Thus, the supply characteristic of the fuel injection amount by the fuel injection valve can be changed as desired.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the fuel injection device according to the present invention will be described below. FIG. 1 shows a first embodiment, which is different from the conventional one in the pressure regulator portion, and is otherwise the same as the conventional one. In the pressure regulator,
The same reference numerals are used for the same structural parts as those of the conventional pressure regulator, and the description thereof will be omitted. Also, during the explanation,
The top, bottom, left, and right are not limited to those shown in the figures.

Reference numeral 1 is a locking member composed of an annular flat plate 1A and a connecting rod 1B projecting upward from the annular flat plate 1A. The annular flat plate 1A is inside the pressure chamber 73 and is attached to one end 78A of a spring 78. The connection rod 1B is locked and the pressure chamber 7
3 is slidably guided by the upper housing 70 forming 3
It projects above the upper housing 70.

Thus, the spring 78 is contracted in the pressure chamber 73, and one end 78A of the spring 78 has the locking member 1
The other end 78 of the spring 78 is locked by the annular flat plate 1A of
B is locked on the upper surface of the partition 71.

Reference numeral 2 is an airtight holding member such as a bellows for allowing the locking member 1 to move in the expansion / contraction direction of the spring 78 and for maintaining the airtightness between the periphery of the locking member 1 and the pressure chamber 73.

A coil core 3 is wound around the outer periphery of the coil bobbin 4, and a fixed core 6 is fixedly arranged on the coil bobbin 4. The coil core 3 is arranged so as to face the fixed core 6 and is movable in the coil bobbin 4. An electromagnetic actuator having a movable iron core 7, which controls two positions in the vertical direction by energizing and de-energizing the coil 5, and the state of FIG. The iron core 7 is in the upper position.

Reference numeral 8 denotes an operating rod which is swingably supported by a fixed support shaft 9. The left end portion of the operating rod 8 is connected to the movable iron core 7 by a connecting pin L1 and the locking member 1 is provided. The connecting rod 1B is connected between the movable iron core 7 and the support shaft 9 by a connecting pin L2. The locking member 1, the electromagnetic actuator 3, and the operating rod 8 constitute a spring force adjusting means K.

According to the fuel injection device provided with such a pressure regulator R, when the coil 5 of the electromagnetic actuator 3 is not energized, the (spring force adjusting means K
When the fuel pressurized by the fuel pump P is supplied to the fuel distribution pipe F and the fuel pressure rises above a set constant pressure, the partition 71 resists the spring force of the spring 78. By moving upward, the opening area of the outflow valve seat 76 is increased to increase the outflow amount from the fuel outflow passage 75 to the fuel source T. Therefore, the fuel pressure in the fuel distribution pipe F can be reduced and controlled to a constant pressure.

On the other hand, when the fuel pressurized by the fuel pump P is supplied to the fuel distribution pipe F and the fuel pressure falls below a set constant pressure, the partition 71 moves downward by the spring force of the spring 78. The opening area of the outflow valve seat 76 is reduced to reduce the outflow amount from the fuel outflow passage 75 to the fuel source T. Therefore, the fuel pressure in the fuel distribution pipe F can be increased and controlled to a constant pressure.

When the coil 5 of the electromagnetic actuator 3 is not energized, the fuel injection amount Q injected from the fuel injection valve J into the engine has a straight-line property as shown by the solid line in FIG. The injection amount of the fuel injection valve J is uniquely determined by the energization time Ti.

Next, when the coil 5 of the electromagnetic actuator 3 is energized (during the operation of the spring force adjusting means K), the movable core 7 is moved.
Is attracted to the fixed iron core 6 by the electromagnetic force generated in the coil 5, and the movable iron core 7 moves downward and holds the second position.

According to this, the operating rod 8 swings counterclockwise around the support shaft 9 as a fulcrum, and the locking member 1 receives the rotational force of the operating rod 8 from the connecting pin L2 and moves downward.

According to the downward movement of the locking member 1,
The spring 78 is compressed by the movement of the locking member 1 by the annular flat plate 1A and increases the spring force pressing the partition 71.

Since the spring force of the spring 78 is increased in this way, the regulated pressure of the pressure regulator R is increased, and the fuel pressure flowing in the fuel distribution pipe F is increased by the increased spring force of the spring 78. It will be.

Thus, the fuel injection characteristic of the fuel injection valve is increased as shown by the one-dot chain line in FIG.

Although the embodiment shown in FIG. 1 increases the spring force of the spring 78 of the pressure regulator R by energizing the coil 5 of the electromagnetic actuator 3, the spring 78 is energized by energizing the coil 5. The spring force may be weakened. According to this, the fuel injection characteristic can be reduced as shown by the chain double-dashed line in FIG.

As described above, the fuel injection characteristic of the single fuel injection valve J is variably controlled by operating the spring force adjusting means K, because the output is high when the engine is under high load operation. In the case where it is desired to increase the fuel amount, or when it is desired to reduce the fuel amount for fuel economy during the low load operation of the engine, it is possible to cope with it very easily.

The second embodiment will be described with reference to FIG. This uses a proportional electromagnetic actuator as the spring force adjusting means K, and moves a locking member 11 which is also used as a movable iron core in the vertical direction in accordance with a magnetic attraction force generated by the magnitude of a current value flowing through the coil 10. The ring-shaped flat plate 11A provided at the end of the locking member 11 is a spring 78.
Is locked at one end 78A. In addition, 12 is a leaf spring which supports the locking member 11.

As described above, since the proportional electromagnetic actuator is used as the spring force adjusting means K, the spring force of the spring 78 can be continuously and continuously adjusted.
The curve characteristic (angle) of the fuel injection amount can be freely changed as shown by the dotted line in FIG.

The third embodiment will be described with reference to FIG. This uses a step motor as the spring force adjusting means K, and a rotor 20 and a stator coil 21 each made of a permanent magnet constitute a motor portion, and the rotational movement of the rotor 20 is locked by a feed screw mechanism 22. It is changed to 23 linear reciprocating motions.

That is, the rotor 20 is rotated in either forward or reverse directions by controlling the currents flowing through the plurality of stator coils 21 in a stepwise manner. The spring force of the spring 78 is changed by the annular flat plate 23A of the stop member 23.

Since the spring adjusting means K is controlled by the motor in this way, the spring load of the spring 78 can be changed largely as compared with the proportional electromagnetic actuator of the second embodiment in a smaller size. The degree of freedom in setting the fuel injection amount can be further greatly improved.

As described above, according to the fuel injection device of the present invention, the fuel stored in the fuel source is pressurized by the fuel pump, and the pressurized fuel is arranged in the fuel distribution pipe. The fuel distribution pipe is equipped with a pressure regulator that makes the fuel pressure flowing in the fuel distribution pipe constant through the intake pipe pressure in the vicinity of the injection opening of the fuel injection valve with respect to the intake pipe. In the fuel injection device, the pressure regulator is divided into the fuel chamber and the pressure chamber by the partition body, and in the fuel chamber, the fuel inflow passage connected to the fuel distribution pipe and the fuel source, and the opening end to the fuel chamber are connected. A fuel outflow passage whose opening and closing is controlled by a valve body that moves the outflow valve seat provided in the section in synchronization with the partition body,
A pressure introducing passage that is connected to the vicinity of the intake pipe where the fuel injection valve opens, and a spring that elastically presses the partition toward the fuel chamber is contracted, and one end of the spring is opened. Since the spring force adjusting means is locked to the valve, and the spring force of the spring is variably adjusted during the operation of the engine, the fuel injection amount can be changed by a factor different from the change of the energization time in a single fuel injection valve. This is possible, and the versatility of a single fuel injection valve for an engine can be significantly improved. Therefore, it is not necessary to prepare a plurality of fuel injection valves for the fuel characteristics required by each engine, and it is possible to mass-produce with extremely few specifications, which can greatly improve parts management and production management. The fuel injection valve, and thus the fuel injection device, can contribute greatly to cost reduction.

Further, as the spring force adjusting means, the locking member which is locked at one end of the spring is operated by the electromagnetic actuator which controls two positions in the expansion and contraction direction of the spring. I was able to change the characteristics.

As the spring force adjusting means, a locking member which is locked at one end of the spring is operated by a proportional electromagnetic actuator which moves proportionally in the expansion and contraction direction of the spring by an electromagnetic attractive force generated according to the current flowing through the coil. According to this, the fuel injection characteristic can be linearly adjusted and the angle of the characteristic can be controlled.

Further, as the spring force adjusting means, the locking member locked at one end of the spring is operated by the motor actuator which is displaced in the expansion and contraction direction of the spring by the rotation of the motor. Since it rotates, a large stroke change of the locking member can be obtained, which makes it possible to further increase the degree of freedom in changing the fuel injection characteristics.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a pressure regulator used in a fuel injection device according to the present invention.

FIG. 2 is a diagram showing a relationship between a fuel injection amount and an energization time.

FIG. 3 is a vertical cross-sectional view showing a second embodiment of the pressure regulator used in the fuel injection device according to the present invention.

FIG. 4 is a vertical sectional view showing a first embodiment of a pressure regulator used in the fuel injection device according to the present invention.

FIG. 5 shows a conventional fuel injection device.

[Explanation of symbols]

 R Pressure regulator F Fuel distribution pipe J Fuel injection valve 73 Pressure chamber 78 Spring 1, 11, 23 Locking member K Spring force adjusting means

Claims (4)

[Claims] 1. A fuel pump pressurizes fuel stored in a fuel source, and the pressurized fuel is injected and supplied to an engine through a fuel injection valve arranged in the fuel distribution pipe and to the fuel distribution pipe. Is a pressure regulator R in a fuel injection device having a pressure regulator that makes the pressure of the fuel flowing in the fuel distribution pipe constant with respect to the pressure of the intake pipe near the injection opening of the fuel injection valve with respect to the intake pipe. The fuel chamber 72 is divided into a fuel chamber 72 and a pressure chamber 73 by 71. A fuel outflow passage 75 whose opening / closing is controlled by a valve body 79 that moves the outflow valve seat 76 in synchronism with the partition body 71 is opened, and the pressure chamber 73 is in the vicinity of the intake pipe where the fuel injection valve J is opened. Introduction of pressure A spring 78 that opens the passage 77 and elastically presses the partition 71 toward the fuel chamber 72
And a spring force adjusting means K is locked to one end 78A of the spring to variably adjust the spring force of the spring 78 during engine operation. 2. As the spring force adjusting means, the locking member 1 locked to one end 78A of the spring 78 is operated by an electromagnetic actuator for controlling two positions in the expansion / contraction direction of the spring 78. The fuel injection device according to the paragraph. 3. As the spring force adjusting means, an engaging member 11 engaged with one end 78A of a spring 78 is provided in the coil 1
The fuel injection device according to claim 1, wherein the fuel injection device is operated by a proportional electromagnetic actuator that moves proportionally in the expansion / contraction direction of the spring 78 by an electromagnetic attraction force generated according to a current flowing through zero. 4. The spring force adjusting means is configured such that the locking member 23 locked to one end 78A of the spring 78 is operated by a motor actuator which is displaced in the expansion / contraction direction of the spring 78 by the rotation of the motor. The fuel injection device according to item 1.