JPH0942097A - Fuel injection device in marine engine provided with in-line type electric motor-driven fuel pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a fuel injection device in a marine engine wherein an electric motor-driven fuel pump is a non-displacement type further to be an in-line type arranged in a fuel piping system and to satisfy safety regulation in the marine engine also to facilitate starting operation. SOLUTION: The second electric motor-driven fuel pump P is a non- displacement type to be arranged in series in a fuel pipe. A fuel inflow pipe 34 of the second electric motor-driven fuel pump P communicates with downward a fuel liquid level of a vapor separator V through the second fuel flow path 50, to connect a fuel delivery path 47 to a fuel injection valve J through the third fuel flow path 51. A leak passage 49 is opened to a fuel delivery flow path between a pump part P1 of the second electric motor-driven fuel pump P and a check valve 48 arranged in a flow path in the downstream from the pump part P1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention injects and supplies fuel through a fuel injection valve to an engine (generally referred to as a marine engine) used on the water such as an inboard motor, an outboard motor, a watercraft motorcycle, etc. In particular, in a marine engine equipped with an in-line electric fuel pump in which a fuel pump for pressurizing and supplying fuel in a fuel tank toward a fuel injection valve is arranged in a fuel pipe. The present invention relates to a fuel injection device.

[0002]

2. Description of the Related Art In a marine engine, "the outside of an engine unit integrally formed with the marine engine,
Do not form a pressurized fuel flow path through which highly pressurized fuel will pass. There is a safety regulation. In order to satisfy this regulation, the electric fuel pump was arranged in the fuel pipe away from the fuel tank, and this electric fuel pump was arranged in the vicinity of the marine engine. (As a result, the fuel tank and the electric fuel pump are greatly separated. A so-called in-line electric fuel pump is used. on the other hand,
The electric fuel pump is a Wesco type electric fuel pump that rotates the impeller by the rotation of the motor and causes a pressure difference due to the liquid frictional action before and after the blade groove on the outer periphery of the impeller, thereby boosting the fuel to perform a pumping action. (Non-volume electric fuel pump) is used. This has less fuel discharge pulsation. There is little noise. Since it is an impeller type, the motor part has a low torque and high rotation type, and the motor part can be made smaller and lighter. The impeller can be formed extremely easily by resin molding, and the structure and assembly of the pump part are simple. The pump has few sliding parts and has excellent durability. That is the main reason for adoption.

[0003]

In a fuel injection device for a marine engine equipped with such a conventional in-line type electric fuel pump, when a non-volume type fuel pump such as a Wesco type is used as the electric fuel pump, There is a defect of. The non-volume type electric fuel pump is arranged near the engine unit from the viewpoint of the safety regulation. On the other hand, the fuel tank is arranged at a low position apart from the engine unit because it is necessary to lower the center of gravity of the hull. According to the above, at the time of the first initial starting operation of the engine, the non-volume electric fuel pump cannot suck the fuel from the fuel tank and pressurize and supply the fuel to the fuel injection valve. This means that the vicinity of the pump section consisting of the impeller of a non-volume type electric fuel pump is not filled with fuel. And the self-priming performance of the non-volume type electric fuel pump is small. by. At the time of stop after engine operation, the fuel flow passage (fuel injection valve, fuel distribution pipe side flow passage, etc.) further downstream than the check valve arranged in the fuel discharge passage of the non-volume type electric fuel pump, By closing the fuel flow path with the check valve, the fuel can be retained and retained inside. On the other hand, in the pump section of the non-volumetric electric fuel pump, since the suction passage, the pump passage, and the discharge passage are in communication with each other, the fuel remaining in the fuel pump passes through the passage. Then, the fuel is returned to the fuel tank side, and no fuel remains at least in the vicinity of the pump section (suction path, pump flow path, discharge path). According to the above, when the engine is restarted, good fuel cannot be supplied toward the fuel injection valve for the same reason as above.

The present invention has been made in view of the above problems, and it is a fuel injection device that can satisfy the safety regulations of a marine engine. The electric fuel pump must be an in-line type that is placed in the fuel piping system. The electric fuel pump must be non-volumetric. When starting the engine, the fuel pump should act as a pump at the same time as the starting operation. A first object of the present invention is to provide a fuel injection device for a marine engine that can satisfy the requirements of (1).

[0005]

In order to achieve the above-mentioned object, a fuel injection device for a marine engine equipped with an in-line electric fuel pump according to the present invention,
The fuel under the liquid surface of the fuel, which is supplied into the vapor separator through the first fuel pump and is formed in the vapor separator, is passed through the in-line second electric fuel pump arranged outside the vapor separator. A fuel injection device for a marine engine, comprising an in-line electric fuel pump for supplying the fuel into the fuel distribution pipe and injecting the fuel toward the engine through a fuel injection valve mounted on the fuel distribution pipe, (2) The electric fuel pump is a non-volume type fuel pump, and the pump portion of the fuel pump is disposed below the liquid level of the fuel formed in the vapor separator, and the pump portion and the downstream side of the pump portion. The first feature is that the leak passage is opened in the fuel discharge passage between the check valve and the check valve arranged in the passage.

Further, according to the present invention, a fuel chamber having a diameter substantially the same as the diameter of the pump housing of the second electric fuel pump is pumped upstream of the fuel inflow pipe opening at the end of the second electric fuel pump. A filter that is formed integrally with the housing and that is disposed substantially orthogonal to the longitudinal axis of the pump housing is disposed in the fuel chamber, and the fuel inlet pipe of the second electric fuel pump is provided in the fuel chamber downstream of the filter. The second feature is that the fuel chamber on the upstream side of the filter and the portion below the liquid surface of the fuel of the vapor separator are connected via a pipe.

According to the present invention, the second electric fuel pump encloses a disk-shaped impeller having a large number of radial blade grooves on its outer circumference and the radial blade grooves along the outer peripheral portion of the impeller. And a vapor discharge passage connecting the pump passage and the outside of the pump, the opening of the vapor discharge passage to the outside of the pump. The third feature is that the valve is opened into the fuel chamber on the upstream side of the filter.

[0008]

According to the first feature, the fuel discharge passage between the pump portion and the check valve of the non-volumetric electric fuel pump is opened to the outside by the leak passage, and the pump portion. Is placed below the fuel level in the vapor separator and is in communication therewith. Therefore, during the initial starting operation of the engine and the restart of the engine, fuel is always stored and retained near the pump section. The pump unit can be immersed in the fuel. Thus, at the same time as the engine starting operation, the electric fuel pump acts as a pump, and the fuel can be supplied from the pump portion to the marine engine through the fuel injection valve.

According to the second feature, the fuel chamber is formed to have a diameter substantially the same as the diameter of the pump housing, and the filter is arranged in the fuel chamber so as to be substantially orthogonal to the longitudinal axis of the pump housing. Therefore, a filter having a relatively large filtration area can be extremely easily integrated with the fuel pump.

Further, according to the third feature, since the vapor discharge passage opens into the fuel chamber on the upstream side of the filter,
The vapor generated in the pump section can be quickly discharged to the outside of the pump section, and it is not necessary to use a special discharging means such as a pipe for discharging the vapor.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fuel injection device for a marine engine equipped with an in-line electric fuel pump according to the present invention will be described below. FIG. 1 is a system diagram showing the entire fuel injection device. E is a marine engine, and includes a cylinder 1, a piston 2, an intake valve 3, an exhaust valve 4, an exhaust pipe 5 connected to the inside of the cylinder 1 via the exhaust valve 4, and an inside of the cylinder 1 via the intake valve 3. It is composed of a continuous intake pipe 6. A throttle body 9 in which the area of the intake passage 8 is variably controlled by a throttle valve 7 operated by the driver is connected upstream of the intake pipe 6, and the intake passage 8 opens to the atmosphere side. Reference numeral 10 is a fuel distribution pipe in which a fuel distribution passage 11 is formed and which holds and holds a fuel injection valve J. The fuel in the fuel distribution passage 11 is introduced into the intake pipe 6 via the fuel injection valve J. It is injected and supplied toward. In the multi-point fuel injection device, the fuel distribution pipe 10 has a plurality of fuel injection valves J according to the number of cylinders.
Is arranged, and fuel is injected and supplied from each fuel injection valve J toward each intake pipe 6 connected to each cylinder 1. 12 is
Fuel distribution pipe 1 generated when the fuel injection valve J injects fuel
The fuel distribution passage 1 of the fuel distribution pipe 10 is a pulsation damper that attenuates the fuel pressure pulsation in the fuel distribution passage 11 of 0.
1 is connected and arranged. Reference numeral 13 is a pressure regulator that keeps the fuel pressure constant with respect to the atmospheric pressure or the negative pressure in the intake pipe 6, and is composed of a metal housing, the inside of which is formed by a rubber diaphragm into a spring chamber and a fuel chamber. Fuel supplied from the fuel distribution pipe 10 enters the inlet, fills the fuel chamber and pushes up the valve through the diaphragm, and balances the spring force at the set pressure.
It is recirculated to a fuel tank or a steam separator described later via the. Then, the spring chamber of the pressure regulator 13 and the intake pipe 6 are connected by the negative pressure introducing passage 13A, so that a constant set pressure is maintained with respect to the negative pressure in the intake pipe 6.

T is a fuel tank in which fuel is stored. V is a vapor separator consisting of: 14 is a cup-shaped chamber with an open top and a bottom.
The upper opening of 4 is closed by a lid member 15, and a liquid storage tank 16 is formed by the chamber 14 and the lid member 15. A channel 17 is formed in the lid member 15, and the channel 17
The downstream side of the valve opens into the liquid storage tank 16 via the valve seat 18. Reference numeral 19 denotes a float valve which is arranged in the valve seat 18 and opens and closes a seat hole 18A of the valve seat 18. Reference numeral 20 denotes a float arm rotatably supported by a shaft 21. The first arm 20A of the float arm 20 extends to the left side and is arranged to face the float valve 19, and the second arm 20B has a float 22. Is attached. The float 22 is in the liquid storage tank 16, and the liquid storage tank 1
In the absence of fuel in 6, the float 22 is rotated counterclockwise so that the float valve 1
9 holds the seat hole 18A of the valve seat 18 open. When the fuel is supplied from the flow path 17, the fuel flows into the liquid storage tank 16 through the seat hole 18A of the valve seat 18 to store the fuel in the liquid storage tank 16 and gradually to the liquid storage tank 1
The fuel liquid level in 6 is raised. When the fuel level rises, the float 22 gradually rotates clockwise due to its buoyancy. The clockwise rotation of the float 22 rotates the first arm 20A clockwise to cause the float valve 19 to move. The seat hole 18A of the valve seat 18 is closed. According to the above, in the liquid storage tank 16,
A fuel liquid level XX is formed, and an atmosphere chamber 16A is formed at a position above the fuel liquid level XX. Reference numeral 23 denotes an atmosphere opening hole provided in the lid member 15, one end of which opens to the atmosphere chamber 16A, and the other end of which opens in communication with the intake pipe 6, the throttle body 9, the fuel tank T, or the atmosphere. Further, in this example, the fuel return passage 14 of the pressure regulator 13 is opened to the atmosphere chamber 16A via the lid member 15.

The flow path 17 of the vapor separator V has a first
It is connected to the fuel tank T via the fuel flow path 24, and the first filter 25 and the first fuel pump 26 are arranged in series from the upstream side to the downstream side of the first fuel flow path 24. The first fuel pump 26 is preferably a pulsating pressure drive type diaphragm pump that performs a pumping action by reciprocating the diaphragm with the pulsating pressure generated in the intake pipe 6.

Next, the non-volume type second electric fuel pump P will be described. This is best shown in FIG. This second
The electric fuel pump P includes a pump unit P1 and a motor unit M. 30 is a locking step portion 30 near both ends thereof.
A and 30B are cylindrical pump housings which are open at both ends and are formed with lower locking step portions 30A.
The pump casing 31 and the pump cover 32 are arranged on the upper side so as to be in contact with each other. An arcuate pump flow path 33 is formed by a recess 31A recessed in the lower end surface of the pump casing 31 and a recess 32A recessed in the pump cover 32. The pump flow path 33 has a fuel inflow pipe. An inflow passage 35 connected to 34 and a discharge passage 36 connected to the inside of the pump housing 30 are opened. And the disc-shaped impeller 3
7 is rotatably arranged between the recess 31A of the pump casing 31 including the pump flow path 33 and the recess 32A of the pump cover 32. The impeller 37 has an outer periphery equal to each other in the circumferential direction. A plurality of radially spaced blade grooves 37A are formed. The pump part P1 is configured as described above.

Reference numeral 40 designates a pair of semi-cylindrical permanent magnets arranged so as to face the inner circumference of the pump housing 30, an armature 41 forming a concentric circle is arranged inside the permanent magnets, and further the armature 41. The commutator 42
Is connected. The armature 41 and the commutator 42 are integrally attached to a shaft 43 along the longitudinal axis of the pump housing 30. A brush 44 is slidably contacted with the commutator 42, and the brush 44 is supported by a brush holder 44A. Reference numeral 45 denotes a bearing holder that is fixedly arranged on the locking step portion 30B of the pump housing 30 and closes the upper opening of the pump housing 30. The upper part of the shaft 43 is rotatably supported by the bearing 46A attached to the bearing holder 45, and the lower part of the shaft 43 is the bearing 46B attached to the pump casing 31.
It is supported rotatably. The motor unit M is configured as described above.

The impeller 37 of the pump portion P1 penetrates through the bearing 46B and goes further downward to the lower end 43A of the shaft 43.
The impeller 37 rotates synchronously with the shaft 43. Reference numeral 47 denotes a fuel discharge passage formed on the downstream side of the pump portion P1, inside the pump housing 30 in which the motor portion M is incorporated, and the bearing holder 45.
The fuel discharge passage 47 has a flow passage 45 </ b> A that is formed at the one end and is connected to the inside of the pump housing 30 and the other end is open toward the upper end. Then, a flow passage 45A as a fuel discharge flow passage 47 formed in the bearing holder 45.
A check valve 48 is arranged in the. The check valve 48 is arranged so as to face the seat hole 45B provided in the flow passage 45A, allows a unidirectional fuel flow flowing from the fuel discharge flow passage 47 to the outside, and discharges the fuel from the outside. For the fuel flow in the other direction flowing into the flow path 47, the check valve 4
8 closes and blocks the sheet hole 45B. In other words, the check valve 48 allows the fuel flow discharged from the fuel pump to the outside via the flow passage 45A and prevents the fuel from flowing back into the fuel pump via the flow passage 45A.

The fuel discharge passage 47A between the pump portion P1 and the check valve 48 has a leak passage 4 communicating with the atmosphere.
9 opens. The fuel discharge passage 47A will be described in more detail. The discharge passage 36 of the pump portion P1 and the pump housing 30.
The fuel discharge flow path 47 inside and the flow path 45C upstream of the seat hole 45B of the bearing holder 45 correspond to this.

The non-volume type second electric fuel pump P configured as described above is arranged as follows to form a fuel injection device having an in-line electric fuel pump. It will be described again with reference to FIG. The flow path 17 of the vapor separator V is the first
The first filter 25 and the first fuel pump 26 are connected in series from the upstream side to the downstream side of the first fuel flow path 24, which are connected to the fuel in the fuel tank T via the fuel flow path 24.

The second electric fuel pump P is attached to an engine unit near the marine engine E, and the pump portion P1 of the second electric fuel pump P is formed in the liquid storage tank 16 of the vapor separator V. Is located below H in the direction of gravity from the fuel liquid level X-X. Then, the fuel inflow pipe 34 of the second electric fuel pump P is communicated with the fuel liquid level XX of the liquid storage tank 16 of the vapor separator V via the second fuel flow path 50 formed of a pipe. On the other hand, the flow passage 45A opening to the upper part of the second electric fuel pump P is connected to the fuel distribution passage 11 of the fuel distribution pipe 10 via the third fuel flow passage 51.

In this example, the fuel return passage 14 of the pressure regulator 13 is connected to the steam separator V and opens to the atmosphere chamber 16A, and the atmosphere release hole 23 of the steam separator V faces the intake pipe 6. Open and leak passage 49
Was connected to the atmosphere chamber 16A of the vapor separator V and opened.
The leak passage 49 may be opened to the intake pipe 6, the fuel tank T, or directly to the atmosphere.

Next, the operation will be described. First, the start-up of the engine in a state where the fuel is only in the fuel tank T and there is no fuel in the liquid storage tank 16 of the vapor separator V will be described. When the engine is cranked by starting the engine by rotating the starter motor or the like, a pulsating pressure is generated in the intake pipe 6, and the diaphragm pump as the first fuel pump 26 acts as a pump by this pulsating pressure. . According to this, foreign matter in the fuel in the fuel tank T is removed by the first filter 25 and the fuel in the fuel tank T is boosted in pressure by the first fuel pump 26.
7. Storage tank 1 of vapor separator V via valve seat 18
6 is supplied with fuel, and the liquid level in the liquid storage tank 16 is XX
Is formed. (In the initial state, the float 22 is in the lower position, and the float valve 19 has the valve seat 18
The sheet hole 18A is held open. ) Bubbles are contained in the fuel supplied from the first fuel pump 26 into the liquid storage tank 16 due to the oscillating pressure and temperature conditions, and the fuel containing the bubbles is supplied into the liquid storage tank 16. The air bubbles are separated in the liquid storage tank 16 by buoyancy from themselves, and the air bubbles are discharged from the air chamber 16A into the intake pipe 6 through the air opening 23. Therefore, no bubbles are contained in the fuel in the liquid storage tank 16. In addition, the liquid storage tank 16
When the desired fuel is supplied to the inside of the fuel tank and the fuel level XX rises to a certain position, the float 22 rotates clockwise in response to the rise in the level, whereby the float valve 19 is moved to the seat hole of the valve seat 18. Since 18A is closed, the fuel in the liquid storage tank 16 is stopped, and the fuel does not overflow from the liquid storage tank 16 to the outside. Further, when the fuel in the liquid storage tank 16 is consumed and the fuel level drops, the float 22
Rotates counterclockwise, the float valve 19 opens the seat hole 18A, and fuel is supplied again from the first fuel pump 26. Therefore, the liquid fuel surface is always formed in the liquid storage tank 16.

On the other hand, in the second electric fuel pump P,
The pump portion P1 is arranged below the fuel level XX of the vapor separator V in the weight direction. Also, the leak passage 49 is opened in the fuel discharge passage 47A between the pump portion P1 and the check valve 48 arranged in the passage 45A downstream of the pump portion P1. 1
The fuel flowing into 6 immediately reaches the pump portion P1 of the second electric fuel pump P from the second fuel flow path 50 through the fuel inflow pipe 34 and fills at least the pump portion P1 with the fuel.
More specifically, the inflow passage 35 of the second electric fuel pump P,
The pump passage 33 and the discharge passage 36 are filled with fuel.

Even in the second electric fuel pump P, the motor M rotates in synchronization with the starting operation of the engine, and the impeller 37 of the pump P1 rotates. When the impeller 37 rotates at high speed in the pump passage 33, the fuel in the pump passage 33 is boosted by the fluid frictional resistance generated by the large number of blade grooves 37A, and the boosted fuel is discharged from the discharge passage 36 of the pump casing 31. Pump housing 3
0, the fuel is discharged into the fuel discharge passage 47A inside the bearing holder 45, and this fuel causes the check valve 48 to open from the seat hole 45B by its fuel pressure, and the fuel distribution pipe 10 through the third fuel flow passage 51. Is supplied to the fuel distribution path 11.

The fuel in the fuel distribution passage 11 is injected and supplied into the intake pipe 6 via the fuel injection valve J.
Then, the fuel pressure pulsation in the fuel distribution passage 11 of the fuel distribution pipe 10 generated when the fuel injection valve J injects fuel is attenuated by the pulsation damper 12, and further, the fuel distribution passage 11
The fuel pressure inside is kept constant against the atmospheric pressure or the intake pipe negative pressure by the pressure regulator 13, and excess fuel is directed from the fuel return passage 14 of the pressure regulator 13 toward the atmosphere chamber 16A of the vapor separator V. Is discharged.

As described above, when the engine is started and the engine is operated thereafter, the fuel in the fuel tank T is supplied to the vapor separator V by the first fuel pump 26, and the vapor separator V is supplied.
The fuel in the liquid storage tank 16 is sucked by the second electric fuel pump P and is supplied toward the fuel distribution passage 11 of the fuel distribution pipe 10. Then, the fuel in the fuel distribution passage 11 is continuously injected and supplied to the intake pipe 6 via the fuel injection valve J, and the operation of the engine is performed.

While the second electric fuel pump P is operating, fuel is discharged from the leak passage 49, but the discharge amount of the second electric fuel pump P is higher than the full-open fuel consumption amount of the engine. And has a sufficiently large flow rate, and the leak passage 49 has a relatively small diameter because it only has to serve as an air vent passage in the fuel discharge passage 47A. Therefore, the discharge amount of the second electric fuel pump P is Does not affect.

When the operation of the marine engine is stopped, the driving of the first fuel pump 26 and the second electric fuel pump P is stopped, and the fuel is supplied to the vapor separator V by the first fuel pump 26. Fuel distribution pipe 1 by the second electric fuel pump P
0, the supply of fuel to the fuel injection valve J is stopped. In such a state, fuel is stored in the liquid storage tank 16 of the vapor separator V to form a fuel liquid level, while in the check valve 48, the supply of fuel pressurized from the pump portion P1 is stopped. And the fuel discharge passage 4 located upstream of the seat hole 45B.
Since 7A is kept at atmospheric pressure by the leak passage 49, the check valve 48 closes the seat hole 45B.

According to the above, the third fuel flow passage 51 downstream of the check valve 48 and the fuel distribution passage 11 of the fuel distribution pipe 10 are provided.
The internal fuel does not reversely flow into the fuel discharge passage 47A upstream of the seat hole 45B by the check valve 48, and the fuel is retained and retained in the third fuel flow passage 51 and the fuel distribution passage 11. It On the other hand, the pump portion P1 is located below the liquid surface of the fuel in the liquid storage tank 16 and the fuel discharge passage 47A is kept at the atmospheric pressure by the leak passage 49.
1 can be placed in the fuel.

Then, when the marine engine is started again from the stopped state, the first fuel pump 26 and the second electric fuel pump P are immediately driven, and at this time, the third fuel flow path 51 and the fuel distribution path are already in operation. Fuel is stored and retained in 11
Moreover, since the pump portion P1 of the second electric fuel pump P is disposed in the fuel, the fuel can be injected and supplied toward the intake pipe 6 via the fuel injection valve J without causing a time delay.

As described above, according to the present invention, the pump portion P1 of the non-volume type electric fuel pump P is arranged at the lower position in the direction of gravity of the fuel liquid level of the liquid storage tank 16 of the vapor separator V, and Since the leak passage 49 is opened between the pump portion P1 and the fuel discharge passage 47A between the check valve 48 and the fuel discharge passage 47A, the fuel pipe system (not in the fuel tank T or the vapor separator V) is in-line and non-volume type. A type of electric fuel pump can be arranged and used. According to the above, the non-volume type electric fuel pump can be arranged in the fuel pipe as an in-line type. By adopting the in-line type, the degree of freedom in the arrangement of the electric fuel pump can be further increased, and in particular, it can be brought closer to the unit of the marine engine, and the safety regulation of the marine engine can be satisfied. Further, the in-line type allows the electric fuel pump to be arranged outside the liquid storage tank of the vapor separator, and according to this, the vibration generated by the electric fuel pump causes the fuel liquid level in the liquid storage tank to wavy. In addition, it is possible to prevent the fuel in the liquid storage tank from being heated by the heat radiation of the electric fuel pump and to prevent bubbles from being generated in the liquid storage tank. When the pressure in the fuel discharge passage in the pump housing rises abnormally for some reason, the pressure is immediately released through the leak passage, so that each component in the electric fuel pump is not damaged. .

Next, a second embodiment will be described with reference to FIG. The same reference numerals are used for the same structural parts as those in the first embodiment, and the description is omitted. 60 is the bottom 60
A bottomed cylindrical outer housing having an opening A formed at the upper side, and a locking step portion 60B on the inner periphery near the bottom portion 60A.
Further, a tubular flow channel 60C protruding downward is formed in the bottom portion 60A. The second electric fuel pump P is a non-volume type electric fuel pump similar to that of the first embodiment, but has a check valve 48 in the bearing holder 45.
And the leak passage 49 is not arranged. The second electric fuel pump P is inserted and arranged from the upper opening of the outer housing 60 toward the bottom portion 60A of the outer housing 60, and the cushion member 61 made of a flat rubber material is provided on the lower end surface 32A of the pump cover 32. The cushion member 61 is arranged so as to be locked on a locking plate 62 arranged on the locking step portion 60B of the outer housing 60. At this time, the locking plate 62 and the inner circumference 60C of the outer housing 60
A cylindrical fuel chamber 63 is formed between the bottom and the bottom portion 60A. The fuel chamber 63 has a diameter N of the pump housing 60.
Is formed to have substantially the same diameter as The fuel inflow pipe 34 of the second electric fuel pump P is opened inside the fuel chamber 63.

A filter 64 is arranged in the fuel chamber 63. The filter 64 is made of a material having air permeability such as a metal net, a synthetic resin net, a sponge, a foamed resin, a filter paper, and a sintered metal, and is integrally formed with the filter cup 66, and the filter is a pump housing 30.
Are arranged substantially orthogonal to the longitudinal axis of the. The filter cup 66 includes the locking plate 62 and the outer housing 6.
It is arranged in the fuel chamber 63 between the zero bottom portion 60A. According to the above, the fuel chamber 63 includes the filter 64, the fuel chamber 63A on the downstream side of the filter 64, and the filter 6
No. 4 upstream fuel chamber 63B, the fuel inflow pipe 34 of the second fuel pump P is opened to the downstream fuel chamber 63A of the filter 64, and the flow passage 60C is upstream of the filter 64. Open toward 63B.

On the other hand, in the upper opening of the outer housing 60, a lid member 65 that contacts the bearing holder 45 is arranged. The lid member 65 is formed with a flow passage 65A which is continuous with the fuel discharge flow passage 47 formed in the bearing holder 45. The flow passage 65A is formed with an outward seat hole 65B and further in a seat hole 65B. Check valve 48 facing each other
Is arranged. The leak passage 49 opens in the flow passage 65C on the upstream side of the seat hole 65B. The leak passage 49 may be opened in the fuel discharge passage between the seat hole 65B and the pump portion P1 as in the above embodiment.

As described above, the filter cup 66 having the cushion member 61, the locking plate 62, and the filter 64 is arranged on the lower end surface 32A of the pump cover 32 from the upper opening of the outer housing 60 toward the bottom portion 60A. The second electric fuel pump P is arranged, and then the lid member 65 that abuts the bearing holder 45 is arranged in the upper opening of the outer housing 60. Thereafter, the upper end of the outer housing 60 is directed inward toward the lid member 65. Caulking. Due to the above, the diameter N of the pump housing 30 of the second electric fuel pump P is provided upstream of the fuel inflow pipe 34 of the second electric fuel pump P.
The fuel chamber 63 having substantially the same diameter as that of the pump housing 30 can be formed integrally with the pump housing 30.

The fuel chamber 63 and the filter 6
The pump portion P1 of the second electric fuel pump having the No. 4 is arranged at a position lower than the fuel level XX of the vapor separator V in the direction of gravity, and the flow passage 60C formed below the outer housing 60 is the second. The pipe 67 serving as the fuel flow path 50 communicates with a portion below the fuel liquid level of the vapor separator V.

According to the second embodiment, a fuel chamber 63 having a diameter substantially the same as the diameter N of the pump housing 30 is formed integrally with the pump housing 30 of the second electric fuel pump, and the diameter of the filter 64 is made smaller. Since the diameter can be made substantially the same as the diameter N of the pump housing 30, the filter 64 having a large filtration area can be attached to the fuel pump itself. According to the above, in the in-line type in which the second electric fuel pump is arranged in the fuel pipe, it is not necessary to select a place to install the filter or to arrange the filter pipe by disposing the filter in the fuel pipe. It is a thing. Further, since the outer circumference of the pump housing 30 is surrounded by the outer housing 60, the pump housing 30
Can be prevented, and further, the noise generated inside the pump housing 30 can be prevented from leaking to the outside. or,
Since the filter 64 can be arranged very close to the pump part P1, the distance between the filter 64 and the pump part P1 can be made as short as possible, and extremely cleanly filtered fuel can be supplied to the pump part P1.

Here, as the second non-volume type electric fuel pump, radial blade grooves are provided on the outer periphery of the above-mentioned impeller, the impeller is rotated at a high speed in the pump passage, and the pump passage is caused by the fluid friction resistance. When a regenerative pump that boosts and discharges the internal fuel pressure is used, it is necessary to provide a vapor discharge path for discharging the vapor generated in the pump flow path to the outside. (This vapor discharge passage is known in Japanese Patent Laid-Open No. 60-79193.) Then, in the present invention, the vapor discharge passage 70 connected to the pump passage 33 is opened in the fuel chamber 63B on the upstream side of the filter. . The vapor discharge path 70 is shown in FIG. Specifically, the vapor discharge passage 70 includes the pump cover 32,
The cushion member 61 and the locking plate 62 were penetrated to connect the pump passage 33 and the fuel chamber 63B on the upstream side of the filter. According to the above, when the fuel containing air bubbles flowing in the vapor discharge passage 70 does not require a pipe to the outside, for example, the fuel tank T, and the regeneration pump is used as the in-line second electric fuel pump, Great effect.

[0038]

According to the first invention of the fuel injection device for a marine engine equipped with the in-line electric fuel pump according to the present invention, the non-volume second electric fuel pump is started at the same time as the starting operation at the time of starting the engine. More fuel can be supplied to the marine engine, and the engine can be started and operated well. Since the second electric fuel pump is of the in-line type, it can be arranged very easily in the vicinity of the engine unit, and the fuel injection device that can satisfy the safety regulation in the marine engine can be provided. Since the non-volume type second electric fuel pump can be adopted as the in-line type, the advantages of the non-volume type electric fuel pump (the discharge pulsation is small, the noise is small, the motor unit can be small and lightweight, and the pump unit (Structure, easy assembly, and good durability) can be used as they are. The pressure inside the pump housing does not rise abnormally and the components inside the electric fuel pump are not damaged. The second electric fuel pump does not cause the fuel in the liquid storage tank, the fuel tank, and the fuel in the liquid tank to rise, and the temperature of the fuel does not rise. It has a special effect.

According to the second aspect of the invention, since the filter is integrally arranged in the fuel chamber of the second electric fuel pump, the filter can be arranged very easily in the in-line type. Further, since the fuel chamber is formed to have a diameter substantially the same as the diameter of the pump housing, the filtration area of the filter can be sufficiently secured.

Further, according to the third aspect of the invention, when the second electric fuel pump is a regenerative pump, the opening on the discharge side of the vapor discharge path is extremely simple.

[Brief description of drawings]

FIG. 1 is a system diagram showing a fuel injection device in a marine engine equipped with an in-line electric fuel pump according to the present invention.

FIG. 2 is a longitudinal sectional view showing an embodiment of a second electric fuel pump according to the present invention.

FIG. 3 is a vertical sectional view showing another embodiment of the second electric fuel pump of the present invention.

[Explanation of symbols]

30 pump housing 33 pump flow path 34 fuel inflow pipe 35 suction path 36 discharge path 37 impeller 37A vane groove 47A fuel discharge flow path between the pump part and a check valve arranged in a flow path downstream of the pump part 48 Check Valve 49 Leak Passage 63 Fuel Chamber 64 Filter 67 Pipe 70 Vapor Discharge Passage P Second Electric Fuel Pump P1 Pump Part V Steam Separator XX Fuel Level Formed in Steam Separator

Claims (3)

[Claims] 1. A fuel in a fuel tank is supplied into a vapor separator via a first fuel pump, and a fuel formed in the vapor separator and below the liquid surface of the fuel is disposed outside the vapor separator. An in-line electric fuel pump for supplying the fuel into the fuel distribution pipe through an in-line second electric fuel pump and injecting the fuel toward the engine through a fuel injection valve mounted in the fuel distribution pipe. In the fuel injection device for a ship engine, the second electric fuel pump P is a non-volume type fuel pump, and the pump portion P1 of the fuel pump has a fuel level X formed in the vapor separator V. The fuel discharge passage 47, which is arranged at a position lower than -X, between the pump portion P1 and the check valve 48 arranged in the passage on the downstream side of the pump portion P1.
A fuel injection device in a marine engine equipped with an in-line electric fuel pump, wherein a leak passage 49 is opened in A. 2. A fuel chamber 63 having a diameter substantially equal to a diameter N of a pump housing 30 of the second electric fuel pump P is provided upstream of the fuel inflow pipe 34 opening at an end portion of the second electric fuel pump P. Is integrally formed with the pump housing 30, and a filter 64 is disposed in the fuel chamber 63 so as to be substantially orthogonal to the longitudinal axis of the pump housing 30, and the fuel inlet pipe 34 of the second electric fuel pump P is disposed. Filter 64
The fuel chamber 63A on the downstream side of the filter
Upstream of the fuel chamber 63B and the fuel liquid level X- of the vapor separator V
The fuel injection device for a marine engine provided with an in-line electric fuel pump according to claim 1, characterized in that the lower part of X is connected via a pipe 67. 3. The second electric fuel pump P includes a disk-shaped impeller 37 having a large number of radial blade grooves 37A on its outer periphery, and a radial blade groove 37A surrounding the outer peripheral portion of the impeller 37. And an annular pump flow path 33 extending from the suction path 35 to the discharge path 36.
3 and a vapor discharge passage 70 that communicates with the outside of the pump, and the opening of the vapor discharge passage 70 to the outside of the pump is the fuel chamber 63 on the upstream side of the filter 64.
The fuel injection device for a marine engine provided with an in-line electric fuel pump according to claim 2, wherein the fuel injection device is opened into B.