JP2000274332A - Fuel feeding device for fuel injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attenuate the pulsating pressure, as well as to suppress an excessive rise of the fuel pressure in a fuel distribution route, without receiving the influence of the pressure variation in the first flow passage connecting to a fuel pump. SOLUTION: A fuel pressure control device S is composed of a fuel pressure regulator R at one side of a housing 1, and a pulsation damper D at the other side of the housing 1, the first fuel chamber 4 is formed of the first recess 1A of the housing 1 and a regulator diaphragm 3, and a pressure chamber S is formed of the first cover 2 and the regulator diaphragm 3. To the first fuel chamber 4, the second flow passage 8 furnishing a regulation valve to open and close a valve seat 7, and the first passage hole 1H connecting to the first flow passage 1A, are opened. At the pulsation damper D, the second fuel chamber 23 is formed of the third recess 1F and a deep mountain form of pulsation diaphragm 21 of the housing 1, and an atmosphere chamber 22 is formed of the second cover 20 and the pulsation diaphragm 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel tank in which fuel in a fuel tank is pressurized by a fuel pump and supplied to a fuel distribution pipe.
On the other hand, the pressurized fuel is regulated to a predetermined control pressure by a fuel pressure regulator, and the fuel regulated to the predetermined control pressure is injected and supplied toward the engine from a fuel injection valve mounted on a fuel distribution pipe. The present invention relates to a fuel supply device in a fuel injection device.

[0002]

2. Description of the Related Art Japanese Patent No. 2774730 is a fuel supply device in a conventional fuel injection device. (The following description uses the names and symbols described in the specification of the patent.) According to this, when the engine is stopped, the valve 104 of the demand type regulator is actuated by the spring force of the compression spring 116. The suction port 103 is held open. Here, when the engine is started and the pump 82 is driven, the pressure of the fuel in the fuel tank 80 is increased by the pump 82, and the pressure in the chamber 10 is increased through the outlet passage 86 and the suction port 103.
9, the fuel pressure in the chamber 109 gradually increases,
The diaphragm 106 moves the compression spring 1 by the fuel pressure.
16 is displaced toward the chamber 120 while being compressed. According to the displacement of the diaphragm 106 toward the chamber 120, the valve 104 is displaced synchronously with the diaphragm 106 toward the chamber 120 by the spring force of the spring 105.
04 closes the suction port 103. Therefore, the drawer passage 8
6 is prevented from flowing into the chamber 109,
The flow of the fuel flowing through the extraction passage 86 is prevented from flowing into the inside, and the supply of the fuel pressure (A) kg / cm ² (for example, 3.5 kg / cm ² ) flowing through the extraction passage 86 into the chamber 109 is shut off. The fuel pressure (A) kg /
The fuel pressure can be regulated and maintained at a predetermined control pressure (B) kg / cm ² (for example, 3 kg / cm ² ) lower than cm ² . Here, when the fuel is injected from the fuel injection valve attached to the fuel distribution pipe and the fuel in the chamber 109 is consumed, the fuel pressure in the chamber 109 falls below the predetermined control pressure (B) kg / cm ^2. (For example, 2.7 kg / cm ² ). According to this, the pressing force of the fuel pressure in the chamber 109 toward the chamber 120 decreases due to the fuel pressure in the chamber 109, and the diaphragm 106 corresponds to the decrease in the pressing force. Is the compression spring 1
16 is displaced toward the chamber 109 by the spring force of
4 opens the suction port 103 again. According to the above, the fuel pressure (A) kg / cm ² is again returned through the extraction passage.
Since (3.5 kg / cm ² ) of fuel is supplied into the chamber 109, the fuel pressure in the chamber 109 can be returned to the predetermined control pressure (B) kg / cm ² again. Thereafter, the predetermined control pressure (B) kg / cm ² can be continuously maintained in the chamber 109 by the opening / closing operation of the valve 104 as described above. When the temperature of the fuel in the fuel distribution pipe is significantly increased, for example, during a hot soak of the engine or during long-time continuous low-speed operation, the fuel in the fuel distribution pipe expands, and the volume of the fuel in the fuel distribution pipe increases significantly. Fuel pressure rises excessively. Here, in the above state, the demand type regulator 10 connected to the fuel distribution pipe is provided.
When the fuel pressure in the chamber 109 of the zero (0) greatly increases, firstly, the diaphragm 106 is displaced toward the chamber 120 against the spring force of the compression spring 116 to absorb the increase in the volume of fuel in the chamber 109, In 2, the valve 104 opens the suction port 103 against the spring force of the spring 105, and releases the excessive fuel pressure in the chamber 109 through the extraction passage 86 and the bypass passage 92. Thus, the room 10 at the time of hot soaking of the engine, etc.
The generation of an excessive fuel pressure in the fuel distribution pipe including the fuel cell 9 is suppressed.

[0003]

According to the prior art,
The chamber 10 including the fuel distribution pipe at the time of hot soak in Seki
The fuel pressure in 9 is a predetermined control pressure (B) kg / cm^Two Over
Excessive fuel pressure (C) kg / cm^Two Come on when outbreaks occur
Then, the valve 104 opens the suction port 103 and the chamber 109 is opened.
The fuel pressure in the chamber is drawn out through the passage 86 and the bypass 92.
To open the fuel tank 80, but the fuel pressure in the chamber 109
Opening pressure of the valve cannot be specified accurately. That is,
The valve 104 is in the chamber 109 which acts on the valve body as an opening-side force.
Fuel pressure of (a) kg / cm^Two And a force on the closing side of the valve body
Pressure (b) kg /
cm^Two Pressure difference (ab), a> b
For the first time, the valve 10 resists the spring force of the spring 105.
4 opens the suction port 103. On the other hand, the drawer passage 86
The fuel pressure flowing inside is increased by the fuel pump
The discharged fuel is controlled by the bypass type regulator 90.
It is determined by adjusting the pressure.
3.5kg / cm like^Two Is adjusted to the fuel pressure. Naturally
In this bypass type regulator 90
Is 3.5 kg / cm^Two When the pressure rises above
3.5 kg / cm by releasing pressure^Two that's all
To prevent the pressure from rising
3.5kg / cm^Two Does not maintain. For example, fuel
Pressure is 3.2kg / cm^Two 3.3kg / cm^Two 3.
4kg / cm^Two When it fluctuates,
The ruler 90 does not operate at all (for example, 3.
6kg / cm^Two ) When the pressure rises
Release the rising pressure to 3.5 kg / cm^Two More pressure
It is a thing which stopped rising. That is, a drawer
It is difficult to keep the fuel pressure in the passage 86 constant.
You. If the above is explained by taking an example, the (a-
The differential pressure of b) is 0.3 kg / cm^Two At valve 104
Opens the suction port 103 against the spring force of the spring 105
When the fuel pressure in the drawer passage 86 is set to 3.
2kg / cm^Two , The fuel pressure in the chamber 109 becomes 3.
5kg / cm ^Two And the differential pressure is 0.3 kg / cm
^Two And the valve 104 opens the suction port 103.
The fuel pressure in the outlet passage 86 is 3.3 kg / cm^Two In
And the fuel pressure in the chamber 109 is 3.6 kg / cm^Two On
And the differential pressure is 0.3 kg / cm^Two Reached valve 1
04 opens the suction port 103. In the drawer passage 86
Fuel pressure is 3.4kg / cm^Two In the room 109
3.7kg / cm fuel pressure^Two And the differential pressure rises
0.3kg / cm^Two And the valve 104 reaches the suction port 1
Release 03. As described above, the valve 104 sucks.
Open the inlet 103, release the fuel pressure in the chamber 109
The starting pressure cannot be determined accurately.

Further, as described above, the excessive fuel pressure generated in the chamber 109 is released to the draw-out passage 86 and the bypass passage 92 by the valve 104 opening the suction opening 104. 109
A collision occurs with the fuel going to. That is, the pressure of the fuel that is pressurized by the fuel pump and flows toward the suction port 104 and the pressure of the fuel that flows from the chamber 109 toward the drawing path 86 via the drawing port 104 are equal to the drawing path 86.
In the drawer passage 8
6, a vibration may be generated, and this vibration may generate noise from the fuel pressure regulator and its piping system.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem. Even when the discharge pressure of the fuel pump fluctuates and the fuel pressure in the flow path toward the fuel chamber of the fuel pressure regulator fluctuates, the flow path of the fuel pressure regulator is not changed. To accurately suppress the fuel pressure in the fuel distribution pipe including the fuel chamber without being affected by pressure fluctuations in the inside. And the generation of noise from the fuel pressure regulator and its piping system. It is a first object of the present invention to provide a fuel supply device in a fuel injection device that can perform the above.
Further, when the fuel injection valve closes the fuel injection hole and the supply of fuel is stopped, the extremely large fuel pressure generated in the fuel distribution pipe is effectively attenuated, and the pulsating pressure generated in the fuel distribution pipe is reduced. It is a second object of the present invention to provide a fuel supply device in a fuel injection device that can be attenuated effectively.

[0006]

According to the present invention, there is provided a fuel supply device in a fuel injection device according to the present invention, wherein a first flow passage opening toward one end and a first flow opening toward one side end are provided to achieve the above object. A concave portion, a second concave portion opening to the first concave portion, a first through hole communicating the first concave portion with the first flow path, a third concave portion opening toward the other end, a third concave portion, and a third concave portion. A housing formed by a second through hole communicating with the one flow path, and a first cover that covers the housing and one side end of the housing,
A regulator diaphragm defining a first fuel chamber in the first recess and partitioning the pressure chamber with the first cover, one end of which opens into the first fuel chamber via a valve seat, and the other end in the second recess; A flow path member having a second flow path that opens to the valve element, a valve element spring disposed in the second flow path of the flow path member, and urging a regulated valve element that opens and closes the valve seat toward the valve seat. A fuel pressure regulator formed by a regulator spring, which is contracted in the pressure chamber and biases the regulator diaphragm toward the first fuel chamber, and is sandwiched between the other end of the housing and a second cover covering the same; A pulsation diaphragm having a deep mountain shape in which a second fuel chamber is formed in the third concave portion and an air chamber is formed separately in the second cover; A fuel pressure control device including a pulsation damper portion including a damper spring biased to the side; an electric fuel pump including a suction passage and a discharge passage; A strainer ST that removes foreign matter contained in the fuel tank and discharges it from the outflow passage, a second regulator diaphragm that divides the housing and the cover into a fuel chamber and a back pressure chamber, and opens into the fuel chamber through a second valve seat. A fuel discharge passage, a fuel inflow passage opening into the fuel chamber, a second regulating valve body formed integrally with the second regulator diaphragm to open and close the second valve seat, and a second regulation contracted into the back pressure chamber. A second regulator spring configured to bias the second regulating valve body to close the second valve seat via the rate diaphragm. More becomes, a second fuel pressure regulator inhalation passage of an electric fuel pump via the first flow path a discharge passage while opening into the fuel tank
The strainer ST is connected and arranged in the first flow path, the fuel inflow path of the second fuel pressure regulator is connected to the first flow path through the second flow path, and the fuel discharge path is connected to the fuel tank. And communicates with the fuel distribution path of the fuel distribution pipe via the first flow path of the fuel pressure control device, and increases the fuel pressure in the first flow path, which is increased in pressure by the electric fuel pump, to the second fuel. First predetermined control pressure (A) kg / cm by pressure regulator
² , and the first predetermined control pressure (A) kg / cm ² supplied to the fuel pressure regulator from the first flow path is changed to the second predetermined control pressure (B) by the fuel pressure regulator.
The pressure is adjusted to kg / cm ² and supplied into the fuel distribution pipe of the fuel distribution pipe. On the other hand, the pulsation pressure generated in the fuel distribution pipe of the fuel distribution pipe is attenuated by the pulsation damper portion and generated in the fuel distribution pipe. Operating the pulsation diaphragm of the pulsation damper section toward the atmosphere chamber at an excessive fuel pressure (C) kg / cm ² exceeding (A) kg / cm ² and (B) kg / cm ^2. Is a first feature.

Further, in addition to the first feature, the present invention further comprises setting a set spring force of a regulator spring of the fuel pressure regulator to be smaller than a set spring force of a second regulator spring of a second fuel pressure regulator. Set the spring force of the damper spring at the damper
A second feature is that the spring force is smaller than the set spring force of the regulator spring of the fuel pressure regulator.

[0008] Further, in the present invention, in addition to the first feature, a third feature is that the second flow path is connected to a first flow path downstream of the strainer ST.

[0009]

According to the first feature, the fuel in the fuel tank is
Is boosted by an electric pump and
Foreign matter is removed and supplied into the first flow path, and
The fuel pressure is set to the first predetermined level by the second fuel pressure regulator.
Control pressure (A) kg / cm ^Two Is regulated. Fuel pressure legging
The first predetermined control force is applied to the
The pressurized fuel is supplied to the fuel pressure regulator.
The second predetermined control pressure (B) kg / cm^Two To
The regulated fuel is supplied into the fuel distribution pipe, and the fuel distribution pipe is
The fuel inside is injected and supplied to the engine via the fuel injection valve.
You. Pulsation pressure generated in the fuel distribution pipe is pulsation
Attenuated and smoothed by the damper part. Also fuel
The first and second predetermined control pressures generated in the distribution pipe are increased.
Excessive fuel pressure exceeding just
Pulsation diaphragm with damper spring
Large displacement toward the atmosphere chamber against the
Absorbed.

According to the second feature, the fuel pressure in the first flow passage can be adjusted to the highest first predetermined control pressure (A) kg / cm ² by the second fuel pressure regulator,
The second predetermined control pressure (B) lower than the first predetermined control pressure (A) kg / cm ² by the fuel pressure regulator unit
kg / cm ^2, and the second predetermined control pressure (B) kg / cm ² can be supplied to the fuel distribution pipe. The pulsation damper absorbs pulsating pressure generated in the fuel distribution pipe. Further, the fuel pressure in the fuel distribution pipe is set to the predetermined control pressure (B) kg / cm ² , (A) kg / cm ²
When the pressure exceeds, the rising pressure is immediately absorbed by the pulsation diaphragm of the pulsation damper.

According to the third feature, foreign matter contained in the fuel flowing into the second fuel pressure regulator is removed by the strainer ST and only clean fuel is supplied, so that the opening and closing characteristics of the second valve seat are improved. Can.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a fuel supply device in a fuel injection device according to the present invention will be described below with reference to the drawings. The fuel pressure control device S is formed by a fuel pressure regulator R and a pulsation damper D. Reference numeral 1 denotes a housing, which includes the following. 1A is a first flow path that opens toward one end (the left side in the figure), 1B is a first recess that opens toward one side end 1C (the upper side in the figure), and 1D is a first recess 1B. The second recess is further recessed downward from the bottom 1E of FIG. 1F is a third opening toward the other end 1G (downward in the figure).
It is a recess. Then, the first recess 1B and the first flow path 1A
Are communicated via the first through hole 1H, and the third recess 1F and the first flow path 1A are communicated via the second through hole 1J. still,
The outer periphery of the first flow path 1A has a cylindrical shape.

A fuel pressure regulator R is formed on one side of the housing 1 as follows. 2 is
The first cover covers the opening of the first recess 1B, and a regulator diaphragm 3 is arranged and sandwiched between one side end 1C and the first cover 2. According to the above description, one side of the regulator diaphragm 3 and the first side of the housing 1
The first fuel chamber 4 is formed by the recess 1 </ b> B, and the pressure chamber 5 is separately formed by the other side surface of the regulator diaphragm 3 and the first cover 2. Reference numeral 6 denotes a flow path member. Inside the flow path member, there is provided a second flow path 8 whose upper side is opened to the upper end via a valve seat 7 and is opened toward the lower end. Regulated valve element 1 pressed by valve element spring 9 to open and close valve seat 7 and close valve seat 7
0 is placed. The flow path member 6 including the regulating valve body 10 and the valve body spring 9 is press-fitted and arranged in the second concave portion 1D of the housing 1. At this time, the upper part of the second flow path 8 is provided via the valve seat It opens in the first fuel chamber 4 and opens in the second recess 1D below. That is, the second concave portion 1D
Opens into the first fuel chamber 4 via the second flow path 8 and the valve seat 7. Reference numeral 11 denotes a regulator spring contracted into the pressure chamber 5, one end of which is engaged with the bottom of the first cover 2, and the other end of which is engaged with a retainer which is integrally attached to the regulator diaphragm 3, which will be described later. Is done. The retainer 12 is integrally attached to the regulator diaphragm 3, and has a cup for locking the regulator spring 11 on the pressure chamber 5 side of the regulator diaphragm 3, and is provided on the first fuel chamber 4 side of the diaphragm 3. Has a locking flange portion, and further has a regulating rod 12A having a rod shape directed downward from the locking flange portion.
Are formed to protrude. The regulating rod 12A is arranged facing the regulating valve body 10. When the valve body spring 9 and the regulator spring 11 are set, the spring force of the regulator spring 11 is stronger than that of the valve body spring 9. According to this, any pressure is applied to the pressure chamber 5 and the first fuel chamber 4. In a state in which the regulating valve 12A is not provided, the regulating rod 12A separates the regulator valve element 10 from the valve seat 7, and holds the second flow path 8 open in the first fuel chamber 4.
2A is a pressure introduction hole formed in the first cover 2.

A pulsation damper D is formed on the other side of the housing 1 as follows. 20 is
A pulsation diaphragm 2 having a deep mountain shape is formed between the other side end 1G and the second cover 20. The pulsation diaphragm 2 has an air hole 20A covering the opening of the third recess 1F.
1 is arranged and fixed. According to the above, the atmosphere chamber 22 is formed by one side surface of the pulsation diaphragm 21 and the second cover 20, and the second fuel chamber 23 is formed separately by the other side surface of the pulsation diaphragm 21 and the third recess 1 </ b> F of the housing 1. Is done. The second fuel chamber 23 is connected to the first flow path 1A through the second through hole 1J. 24
Is a damper spring contracted into the atmosphere chamber 22, one end of which is locked to the bottom of the second cover 20, and the other end of which is connected to the pulsation diaphragm 2 via a retainer 25.
1 locked on. The set spring force of the regulator spring 11 of the fuel pressure regulator R and the set spring force of the damper spring 24 of the pulsation damper D are defined by the set spring force of the damper spring 24. It is set to be smaller.

The fuel distribution pipe F is provided with a fuel distribution passage 30 which is open toward the right end in the longitudinal direction, and a plurality of fuel injection valve insertion holes 31 which are crossed with the longitudinal axis. .

Next, other members constituting the fuel supply device will be described below. P denotes an electric fuel pump formed by a motor unit and a pump unit, which sucks fuel into the pump unit via a filter 41 mounted on a suction passage 40, and outputs fuel pressurized by the pump unit to a discharge passage 42. Is ejected through. ST is the strainer and the inflow channel 4
Foreign matter in the fuel flowing in from 3 is filtered by a filtering member housed and arranged inside, and clean fuel is discharged from the outflow passage 44. G is a second fuel pressure regulator,
A second regulator diaphragm 47 is sandwiched between the housing 45 and the cover 46. A back pressure chamber 70 is formed by one side surface of the second regulator diaphragm 47 and the cover 46.
Is formed, and the other side surface of the second regulator diaphragm 47 and the housing 45 form a fuel chamber 48.
The fuel discharge passage 51 opens through the valve seat 50. 52 is integrally attached to the second regulator diaphragm 47,
A second regulating valve for opening and closing the second valve seat 50;
The second regulating valve body 52 is compressed by a second regulating spring 53 in the back pressure chamber 70 so that the second valve seat 5 is closed.
0 is urged to the closing side.

Here, the set spring forces of the regulator spring 11 of the fuel pressure regulator R, the second regulator spring 53 of the second fuel pressure regulator G, and the damper spring 24 of the pulsation damper D are the second regulator. The spring 53 is set to the strongest, the regulator spring 11 is set to the strongest, and the damper spring 24 is set to the weakest.

The above components are arranged as follows to form a fuel supply device. A fuel pressure control device S having a fuel pressure regulator R and a pulsation damper D is attached to the fuel distribution pipe F as follows, and a known fuel is inserted into the fuel injection valve insertion hole 31 of the fuel distribution pipe F. The rear end of the injection valve J is inserted and arranged. Next, the cylindrical outer peripheral portion 1P formed on the outer periphery of the first flow path 1A of the housing 1 of the fuel pressure control device S is inserted into the fuel distribution passage 30 opened at the right end of the fuel distribution pipe F. 1
Is fixed to the fuel distribution pipe F. The means for fixing the housing 1 to the fuel distribution pipe F and the outer peripheral portion 1P of the housing 1
A sealing means for airtightness between the fuel supply passage 30 and the fuel supply passage 30 is omitted. According to the above description, the fuel distribution path 30 includes the first flow path 1A,
Through the first through hole 1H, the first of the fuel pressure regulator R
The fuel is communicated into the fuel chamber 4 and into the second fuel chamber 23 of the pulsation damper D via the first flow passage 1A and the second through hole 1J. Then, the tip of the fuel injection valve J mounted on the fuel distribution pipe F is mounted on an intake pipe K connected to the engine E, and the injection hole of the fuel injection valve J opens into the intake pipe K.
Specifically, a stay (not shown) is fixed to the intake pipe K, and a fuel distribution pipe F is fixed to the stay by screwing. The electric fuel pump P including the filter 41 is disposed in the fuel tank T, and the discharge passage 42 of the electric fuel pump P and the second concave portion 1D of the fuel pressure regulator R are connected by the first flow passage 60. The strainer ST is connected to the first flow path 60, and the inflow path 43 of the strainer ST is directed to the discharge path 42 of the electric fuel pump P, and the outflow path 44 is connected to the second recess of the fuel pressure regulator R. Head to 1D. Also, the second
The fuel inflow passage 49 of the fuel pressure regulator G is provided in the second passage 6.
1 and is connected to the first flow passage 60 between the outflow passage 44 of the strainer ST and the second concave portion 1D. Further, the fuel discharge path 51 of the second fuel pressure regulator G is connected to the inside of the fuel tank T via the third flow path 62.

Next, the operation will be described. In the stopped state in which the operation of the engine has been completed, fuel is stored in the fuel distribution path 30 of the fuel distribution pipe F. This is because a one-way control valve that allows only the fuel flow toward the first flow path 60 is disposed in the electric fuel pump P. This one-way control valve is not shown. In this state, the regulating valve element 10 of the fuel pressure regulator R holds the valve seat 7 open.

Next, the operation of the engine will be described. The electric fuel pump P is driven by the operation of the engine.
The fuel in the fuel tank T is sucked into the electric fuel pump P through the filter 41 and the suction passage 40, and the pressurized fuel is discharged into the first flow passage 60 through the discharge passage 42.
The fuel in the first flow path 60 removes foreign matter contained in the fuel by passing through the strainer ST, and a part of the fuel passing through the strainer ST passes through the second flow path 61 and the fuel inflow path 49. The second fuel pressure regulator G flows into the fuel chamber 48 via the second fuel pressure regulator G. The second fuel pressure regulator G regulates the fuel pressure flowing in the primary flow path 60 so as not to exceed a predetermined pressure. For example, the fuel pressure in the primary flow path 60 is controlled to a first predetermined control pressure (A ) Adjust the pressure so that it does not rise above kg / cm ² (for example, 3.5 kg / cm ² ). That is, the fuel chamber 4 of the second fuel pressure regulator G passes through the first flow path 60, the second flow path 61, and the fuel inflow path 49.
When a fuel having a fuel pressure of 3.5 kg / cm ² or more flows into the inside 8, the second regulator diaphragm 47 moves toward the back pressure chamber 70 against the spring force of the second regulator spring 53, and the second regulator The valve body 52 opens the second valve seat 50 and discharges the fuel in the first flow path 60 into the fuel tank T through the third flow path 62, whereby the fuel in the first flow path 60 The pressure is prevented from rising to 3.5 kg / cm ² or more. The fuel pressure in the first flow path 60 regulated by the second fuel pressure regulator R is referred to as a first predetermined control pressure (A) kg / cm ^{2. In} this example, the first predetermined control pressure (A) 3.5) kg / cm ²
kg / cm ² . If the fuel pressure in the primary flow channel 60 does not reach 3.5 kg / cm ² , the second
The regulating valve element 52 is a second regulating spring 5
3 holds the second valve seat 50 closed.

The fuel adjusted to the first predetermined control pressure of 3.5 kg / cm ² as described above is supplied to the first flow path 60.
Through the opening 1S, the second recess 1D, the second flow path 8 and the valve seat 7 into the first fuel chamber 4 of the fuel pressure regulator R. According to the above, the regulator diaphragm 3 including the regulating rod 12A is the first regulator spring 1
1, the regulating valve body 10 is displaced toward the pressure chamber 5 side (upward in the figure) against the spring force of the first valve body 9 so as to close the valve seat 7 by the spring force of the first valve body spring 9. The first fuel chamber 4 is displaced and the flow of fuel from the second flow path 8 into the first fuel chamber 4 is restricted, whereby the fuel pressure in the first fuel chamber 4 is reduced to a second predetermined control pressure (B) kg / cm ²
(For example, 3 kg / cm ² ). The fuel adjusted to the second predetermined control pressure is supplied to the fuel distribution pipe F via the first fuel chamber 4, the first through hole 1H, and the first flow path 1A.
The fuel is supplied from the fuel injection valve J to the engine E via the intake pipe K. On the other hand, according to the consumption of fuel from the fuel injection valve J, the fuel pressure in the first fuel chamber 4 including the fuel distribution passage 30 is increased from the second predetermined control pressure of 3 kg / cm ² to, for example, 2.8 kg / cm ^2.
According to the decrease in the fuel pressure in the first fuel chamber 4, the regulator diaphragm 3 corresponds to the decrease in the fuel pressure due to the spring force of the regulator spring 11, and the lower side of the first fuel chamber 4 (the lower side in the figure). ), The regulating rod 12A presses the regulating valve body 10 to displace the valve seat 7 to the side to be opened again. According to the above, the fuel having the fuel pressure of 3.5 kg / cm ² , which has been increased to the first control pressure in the second flow path 8 again through the valve seat 7, is introduced into the first fuel chamber 4. By this, the fuel pressure in the first fuel chamber 4 is again increased to the second predetermined control pressure of 3 kg / cm.
Held at ² . Thereafter, during the operation of the engine, the above operation is continuously performed, and the fuel distribution path 30 of the fuel distribution pipe F
Inside, a fuel having a ^second predetermined control pressure (B) kg / cm ² is always supplied.

On the other hand, during operation of the engine,
Within 0, a pulsating pressure occurs. This is the fuel distribution path 30
Is caused by the fuel injection valve J continuously opening and closing the valve hole of the valve and the pumping action of the fuel pump. Here, the fuel distribution passage 30 is provided in the second fuel chamber 23 of the pulsation damper section D via the first flow passage 1A and the second through hole 1J.
The fuel pressure inside acts. As described above, the pulsating pressure generated in the fuel distribution passage 30 acts on the pulsation diaphragm 21 via the first flow passage 1A, the second through hole 1J, and the second fuel chamber 23. The pulsation diaphragm 21 receiving the pressure compresses the damper spring 24 in accordance with the magnitude of the pulsating pressure and displaces the damper spring 24 toward the atmosphere chamber 22 (downward in the figure), thereby attenuating the pulsating pressure. At this time, it should be noted that the set spring force of the damper spring 24 of the pulsation damper portion D is made weaker than the set spring force of the regulator spring 11 of the fuel pressure regulator portion R. Effectively attenuating the pulsating pressure in the interior.

The regulator diaphragm 3 of the fuel pressure regulator R does not deny that the pulsation pressure is somewhat attenuated due to the characteristics of the diaphragm.

When the engine suddenly decelerates, the fuel injection from the fuel injection valve J may be temporarily stopped, whereby the valve hole of the valve is temporarily closed and the fuel distribution passage 30 is stopped. In the second control pressure (B) kg / cm
Very large consisting fuel pressure exceeds ² (C) kg / cm ² there may temporarily occur. Here, in the present invention, the extremely high fuel pressure is immediately and effectively suppressed by the pulsation damper portion D, and unnecessary fuel may leak from the fuel injection valve J into the intake pipe K. Absent. That is, the fuel pressure in the fuel distribution path 30
Over the specified control pressure (B) kg / cm ² (C) kg
/ Cm ² , the pulsation diaphragm 21 of the pulsation damper section D senses a pressure increase in the second fuel chamber 23 and displaces largely toward the atmosphere chamber 22 against the spring force of the damper spring 24. Absorb the pressure rise immediately. What should be particularly noted here is that the shape of the pulsation diaphragm 21 is formed into a deep mountain shape, and that the set spring force of the damper spring 24 is smaller than the set spring force of the regulator spring 11, thereby increasing the size. When a fuel pressure (C) of kg / cm ² occurs, the pulsation diaphragm 21
Can be displaced immediately, and the pulsation diaphragm 21 can be displaced largely to the atmosphere chamber 22 side. Therefore, the fuel pressure in the fuel distribution passage 30 including the first fuel chamber 4 and the second fuel chamber 23 is suppressed from rising above the second predetermined control pressure (B) kg / cm ² . , The regulating valve element 10 still closes and holds the valve seat 7, and the second from the valve seat 7.
The fuel pressure in the first fuel chamber 4 does not escape toward the flow path 8. According to the above, during the rapid deceleration operation of the engine, the second predetermined control pressure (B) kg in which the fuel pressure in the fuel distribution passage 30 is controlled by the fuel pressure regulator R.
/ Cm ² , so that fuel does not leak from the fuel injection valve J into the intake pipe K. Further, even when the fuel pressure in the fuel distribution passage 30 rises above the second predetermined control pressure, the regulating valve body 10
Does not open the valve seat 7 and the fuel pressure in the first fuel chamber 4 does not escape through the valve seat 7 to the second flow path 8 and the second recess 1D. , The second recess 1
The pressure collision in D is eliminated, so that noise is no longer generated from the fuel pressure control device S and its piping system.

Further, when the engine is in a hot soak operation or at a low speed operation, the fuel distribution pipe F is heated and the fuel distribution passage 3 is heated.
The fuel temperature in the fuel distribution line 30 greatly increases, the volume of the fuel in the fuel distribution passage 30 greatly increases, and the fuel pressure excessively increases as compared with the second predetermined control pressure (B) kg / cm ² . Here, in the present invention, since the excessive fuel pressure is immediately and effectively absorbed by the pulsation diaphragm 21 of the pulsation damper portion D,
Unnecessary fuel leaks from the fuel injection valve J into the intake pipe K. The generation of noise from the fuel pressure control device S and its piping system is suppressed. This is for the same reason as described above. Note that the setting of the fuel pressure used in the above description is a numerical value used for facilitating the description, and is not limited thereto.

[0026]

As described above, according to the first aspect of the present invention, the fuel in the fuel tank pressurized by the electric fuel pump is regulated to the first predetermined control pressure by the second fuel pressure regulator. The fuel pressure is supplied to the fuel pressure regulator, and the fuel pressure is regulated by the fuel pressure regulator.
And is supplied to the fuel distribution pipe. On the other hand, the pulsating pressure generated in the fuel distribution pipe is effectively attenuated by the pulsation damper. Therefore, it is possible to inject and supply the fuel, which is controlled more accurately than the fuel injection valve, into the intake pipe. In particular, according to the pulsation diaphragm having a deep mountain shape, the fuel pressure in the fuel distribution passage including the fuel chamber exceeds the second predetermined control pressure (B) kg / cm ^2, and the excessive fuel pressure (C) When the pressure increased to kg / cm ² , the pulsation diaphragm was further displaced toward the atmosphere chamber against the spring force of the damper spring. Thus, unnecessary fuel does not leak from the fuel injection valve into the intake pipe, and the engine performance can be maintained satisfactorily. Then, the excessive fuel pressure (C) k
The absorption of g / cm ² is performed by the relationship between the fuel pressure in the fuel chamber including the fuel distribution passage and the spring force of the damper spring.
It is not involved in the fuel pressure in the second recess at all,
Therefore, the excessive fuel pressure can be absorbed and suppressed very accurately. In addition, when the excessive fuel pressure is absorbed by the pulsation diaphragm, the regulating valve body closes and holds the valve seat when the excessive fuel pressure is generated. According to this, the first fuel chamber passes through the valve seat through the valve seat. The backflow of the fuel pressure into the second flow passage and the second recess is suppressed, and the collision of the fuel in the flow passage is eliminated, whereby the vibration in the flow passage is suppressed, and the fuel pressure regulator and its piping system The noise was reduced.
Furthermore, since a single housing is used in common for the housing of the fuel pressure regulator and the housing of the pulsation damper, the number of parts can be reduced, which is effective in reducing the manufacturing cost. Further, when the fuel pressure control device is mounted on the fuel distribution pipe, a single housing may be assembled, so that the assembling work time can be reduced. Further, at the time of maintenance, the maintenance work of the fuel pressure regulator unit and the pulsation damper unit can be performed by removing the fuel pressure control device, thereby greatly improving the maintainability.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part showing an embodiment of a fuel supply device in a fuel injection device according to the present invention.

[Explanation of symbols]

 S Fuel pressure control device R Fuel pressure regulator part D Pulsation damper part F Fuel distribution pipe 1 Housing 1A First flow path 3 Regulator diaphragm 4 First fuel chamber 5 Pressure chamber 7 Valve seat 8 Second flow path 9 Valve spring 10 Regulating valve 11 Regulator spring 21 Pulsation diaphragm 22 Atmosphere chamber 23 Second fuel chamber 24 Damper spring 30 Fuel distribution path P Fuel pump ST Strainer G Second fuel pressure regulator 60 First flow path 61 Second flow path 62 Third Channel

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02M 55/02 340 F02M 55/02 340E 350 350E 350P

Claims (3)

[Claims] 1. A first flow path 1A opening toward one end.
A first recess 1B opening toward one side end 1C, a second recess 1D opening in the first recess 1B, and a first through hole 1H communicating the first recess 1B with the first flow path 1A. , Other end 1G
A housing 1 formed by a third recess 1F opening toward the front, a second through hole 1J communicating the third recess 1F and the first flow path 1A, one side end 1C of the housing 1, and covering the same. A regulator diaphragm 3 sandwiched between the first cover 2 and forming a first fuel chamber 4 in the first recess 1B and separately forming a pressure chamber 5 in the first cover 2;
A flow path member 6 having a second flow path 8 having one end opened to the first fuel chamber 4 via the valve seat 7 and the other end opened to the second recess 1D.
And a valve body spring 9, which is disposed in the second flow path 8 of the flow path member 6 and urges the regulating valve body 10 that opens and closes the valve seat 7 toward the valve seat 7, and is contracted in the pressure chamber 5. A fuel pressure regulator R formed by a regulator spring 11 for urging the regulator diaphragm 3 toward the first fuel chamber 4 and the other end 1G of the housing 1 and a second cover 20 covering the same. And the third recess 1F
To form the second fuel chamber 23 and the second cover 20
And a pulsation diaphragm 21 having a deep mountain shape that forms the atmosphere chamber 22 in a divided manner,
A fuel pressure control device S including a pulsation damper portion D including a damper spring 24 for urging the pulsation diaphragm 21 toward the second fuel chamber 23, and a suction passage 40 and a discharge passage 42. An electric fuel pump P, a strainer ST for removing foreign matter contained in fuel flowing through the inflow passage 43 and discharging the fuel from the outflow passage 44, the housing 45 and the cover 46, the fuel chamber 48 and the back pressure chamber 70. A second regulator diaphragm 47, a fuel discharge passage 51 opening in the fuel chamber 48 via the second valve seat 50, a fuel inflow passage 49 opening in the fuel chamber 48, and a second regulator diaphragm 47. A second regulating valve element 52 formed integrally with the second valve seat 50 to open and close the second valve seat 50; The second regulated valve body through the 52
A second fuel pressure regulator G constituted by a second regulator spring 53 for urging the second valve seat 50 to close.
0 is opened in the fuel tank T, the discharge path 42 is connected to the second flow path 8 of the fuel pressure control device S via the first flow path 60, and the strainer ST is connected and arranged in the first flow path 1A. The fuel inflow passage 49 of the second fuel pressure regulator G is connected to the first flow passage 60 through the second flow passage 61, and the fuel discharge passage 51 is opened in the fuel tank T.
The first flow path 60 of the fuel pressure control device S
The fuel pressure in the first flow passage 60, which is increased by the electric fuel pump P, is adjusted to the first predetermined control pressure (A) kg / cm ² by the second fuel pressure regulator G. The first predetermined control pressure (A) kg / cm ² supplied to the fuel pressure regulator R from the first flow path 60 is applied to the second predetermined control pressure (B) by the fuel pressure regulator R.
The fuel distribution path 30 of the fuel distribution pipe F is adjusted to a pressure of kg / cm ^2.
The pulsation pressure generated in the fuel distribution passage 30 of the fuel distribution pipe F is attenuated by the pulsation damper D, and the predetermined control pressure (A) kg / cm ² and (B) kg / cm
Excessive fuel pressure (C) kg / cm ² exceeding ² is applied to the pulsation diaphragm 2 of the pulsation damper D.
1. A fuel supply device in a fuel injection device, characterized in that the fuel supply device 1 is absorbed by operating it toward the atmosphere chamber 22. 2. The set spring force of the regulator spring 11 of the fuel pressure regulator R is smaller than the set spring force of the second regulator spring 53 of the second fuel pressure regulator G. 2. The fuel supply device according to claim 1, wherein the set spring force is smaller than the set spring force of the regulator spring 11 of the fuel pressure regulator R. 3. The fuel supply device according to claim 1, wherein the second flow path is connected to a first flow path downstream of the strainer.