Information
-
Patent Grant
-
6293296
-
Patent Number
6,293,296
-
Date Filed
Wednesday, October 27, 199924 years ago
-
Date Issued
Tuesday, September 25, 200122 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Sughrue, Mion, Zinn, Macpeak & Seas, PLLC
-
CPC
-
US Classifications
Field of Search
US
- 137 11513
- 137 11526
- 137 563
- 137 56535
- 137 544
- 123 514
- 417 307
-
International Classifications
-
Abstract
A high-pressure fuel pump device which can facilitate the assembly of a high-pressure pump and a high-pressure regulator by standardizing a pump body or a valve housing.The pump body of the high-pressure pump has a high-pressure valve connection portion on the exterior side including a high-pressure passage which is used to connect the high-pressure regulator, the valve housing of the high-pressure regulator has a high-pressure pump connection portion on the exterior side including a high-pressure passage which is used to connect the high-pressure pump, and the high-pressure valve connection portion and the high-pressure pump connection portion are connected to each other to assemble the high-pressure pump and the high-pressure regulator together.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a high-pressure fuel pump device comprising a high-pressure pump and a high-pressure regulator.
2. Description of the Prior Art
Diesel engines are widely known as an example of the engine technology that the fuel is injected into its cylinders, which is so called “in-cylinder injection engine” or “direct injection engine”. For spark ignition (gasoline) engines also, in-cylinder injection types have recently been proposed. For gasoline engines, there have been recently implemented in-cylinder injection type engines. For example, a high-pressure fuel pump device comprising a high-pressure pump and a high-pressure regulator is disclosed by Japanese Patent Publication No. 2689226.
FIG. 14
is a schematic diagram showing an automobile fuel supply system disclosed by the above publication. In
FIG. 14
, reference numeral
1
denotes a delivery pipe which is a fuel injection unit,
2
injectors corresponding to the number of the cylinders of an engine
3
,
4
a high-pressure fuel pump device attached to the housing of the engine
3
,
5
a first housing of the high-pressure fuel pump device
4
,
6
a second housing of the high-pressure fuel pump device
4
,
7
a connection portion between the first housing
5
and the second housing
6
,
8
a high-pressure pump for increasing the pressure of fuel to a high level, and
9
a pumping element
9
incorporated in the first housing
5
. The pumping element
9
has such elements as a piston driven by an unshown cam which turns at a half speed of the crank speed of the engine
3
and a cylinder for holding the piston in such a manner that it can reciprocate. Denoted by
10
is an intake valve arranged at the connection portion
7
,
11
a discharge valve arranged at the connection portion
7
,
12
a high-pressure regulator incorporated in the second housing
6
, for adjusting the pressure of fuel by draining part of high-pressure fuel,
13
a low-pressure passage formed in the first housing
5
,
14
a low-pressure passage of the second housing side formed in the second housing
6
,
15
a high-pressure passage on the first housing side formed in the first housing
5
,
16
a first high-pressure passage on the second housing side formed in the second housing
6
,
17
a second high-pressure passage on the second housing side formed in the second housing
6
,
18
a drain return passage formed in the second housing
6
,
19
a fuel tank,
20
a low-pressure pump stored in the fuel tank
19
,
21
a low-pressure pipe connected to the outlet portion of the low-pressure pump
20
and to the low-pressure passage
14
on the second housing side,
22
a high-pressure pipe connected to the high-pressure passage
16
on the second housing side and to the inlet portion of the delivery pipe
1
,
23
a high-pressure pipe connected to the outlet portion of the delivery pipe
1
and to the second high-pressure passage
17
on the second housing side,
24
a drain return pipe connected to the drain return passage
18
and to the fuel tank
19
, and
25
fuel stored in the fuel tank
19
. The high-pressure pump
8
is composed of such elements as the first housing
5
, the second housing
6
, the pumping element
9
, the intake valve
10
, the discharge valve
11
, the low-pressure passage
13
on the first housing side and the high-pressure passage
15
on the first housing side.
A description is subsequently given of the operation of the above fuel supply system. The low-pressure pump
20
sucks the fuel
25
and increases the pressure of the fuel to a low level. This low-pressure fuel
25
is sucked into the pumping element
9
from the low-pressure pipe
21
through the low-pressure passage
14
on the second housing side, the intake valve
10
and the low-pressure passage
13
on the first housing side. The pumping element
9
increases the pressure of the sucked fuel
25
to a high level and discharges it. This high-pressure fuel
25
is supplied to the delivery pipe
1
through the high-pressure passage
15
on the first housing side, the discharge valve
11
, the first high-pressure passage
16
on the second housing side and the high-pressure pipe
22
. At the fuel injection timing of each cylinder of the engine
3
, the corresponding injector
2
injects the high-pressure fuel
25
into the cylinder of the fuel injection timing. When the pressure of the fuel
25
supplied to the second high-pressure passage
17
on the second housing side from the delivery pipe
1
through the high-pressure pipe
23
exceeds a predetermined level set by the high-pressure regulator
12
, the high-pressure regulator
12
drains part of the fuel
25
in the second high-pressure passage
17
on the second housing side to control the pressure of the fuel supplied to the delivery pipe
1
from the pumping element
9
at a predetermined high level. This drained fuel
25
is returned to the fuel tank
19
from the drain return passage
18
through the drain return pipe
24
.
The above high-pressure fuel pump device
4
of the prior art is structured such that the high-pressure pump
8
includes part of the connection portion
7
, that is, the intake valve
10
and the discharge valve
11
are arranged in the connection portion
7
between the first housing
5
and the second housing
6
. The high-pressure pump
8
can be a single-cylinder pump having only one piston in the pumping element
9
or a multi-cylinder pump having multiple pistons in the pumping element
9
, while the high-pressure regulator
12
can be of a mechanical type for controlling the pressure of fuel to a fixed level or of an electromagnetic type for controlling the pressure of fuel to a variable level. Therefore, with the above mentioned high-pressure pump device
4
, it has been difficult to standardize the design of the first housing
5
and/or the second housing
6
per technologies used for the high-pressure pump
8
, single-cylinder or multi-cylinder, and per the technologies used for the high-pressure regulator
12
, mechanical type or electromagnetic type.
SUMMARY OF THE INVENTION
It is an object of the invention to solve the above problem by providing a high-pressure pump device which can facilitate the assembly of a high-pressure and a high-pressure regulator by standardizing a pump body or valve housing.
According to a first aspect of the present invention, there is provided a high-pressure pump device comprising a high-pressure pump for increasing the pressure of fuel to a high level and a high-pressure regulator for controlling the pressure of fuel by draining part of fuel discharged from the high-pressure pump, wherein the pump body of the high-pressure pump has a high-pressure valve connection portion including a high-pressure passage on the exterior side and used to connect the high-pressure regulator, the valve housing of the high-pressure regulator has a high-pressure pump connection portion including a high-pressure passage on the exterior side and used to connect the high-pressure pump, and those high-pressure connection portions are connected to each other to assemble the high-pressure pump and the high-pressure regulator together.
According to a second aspect of the present invention, there is provided a high-pressure pump device, wherein the high-pressure connection portions on the pump body and on the valve housing are connected to each other by mating.
According to a third aspect of the present invention, there is provided a high-pressure pump device, wherein the pump body has a low-pressure valve connection portion including a low-pressure passage on the exterior side, the valve housing has a low-pressure connection portion including a low-pressure passage on the exterior side, and those low-pressure connection portions are connected to each other and the high-pressure connection portions are connected to each other when the high-pressure pump and the high-pressure regulator are assembled together.
According to a fourth aspect of the present invention, there is provided a high-pressure pump device, wherein the low-pressure connection portions on the pump body and on the valve body are connected to each other face-to-face.
According to a fifth aspect of the present invention, there is provided a high-pressure pump device, wherein the valve housing has a drain return passage for returning fuel to the low-pressure passage of the high-pressure pump.
According to a sixth aspect of the present invention, there is provided a high-pressure pump device, wherein the drain return passage is connected to the low-pressure passage on a downstream side of a filter.
According to a seventh aspect of the present invention, there is provided a high-pressure pump device, wherein the pump body and the valve housing are fastened to each other by bolts together with fuel pipes connected to the valve housing.
The above and other objects, features and advantages of the invention will become more apparent from the following description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
FIG. 1
is a schematic diagram showing a fuel supply system according to Embodiment 1 of the present invention;
FIG. 2
is a schematic diagram showing details of the fuel supply system according to Embodiment 1;
FIG. 3
is a sectional view of a high-pressure fuel pump device according to Embodiment 1;
FIG. 4
is a sectional view of a high-pressure fuel pump device according to Embodiment 2 of the present invention;
FIG. 5
is a sectional view of a high-pressure fuel pump device according to Embodiment 3 of the present invention;
FIG. 6
is a sectional view of a high-pressure fuel pump device according to Embodiment 4 of the present invention;
FIG. 7
is a sectional view of a high-pressure fuel pump device according to Embodiment 5 of the present invention;
FIG. 8
is a sectional view of a high-pressure fuel pump device according to Embodiment 6 of the present invention;
FIG. 9
is a sectional view of a high-pressure fuel pump device according to Embodiment 7 of the present invention;
FIG. 10
is a sectional view of a high-pressure fuel pump device according to Embodiment 8 of the present invention;
FIG. 11
is a sectional view of a high-pressure fuel pump device according to Embodiment 9 of the present invention;
FIG. 12
is a top view of a high-pressure fuel pump device according to Embodiment 10 of the present invention;
FIG. 13
is a sectional view cut on line A—A of
FIG. 12
; and
FIG. 14
is a schematic diagram showing a fuel supply system of the prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1
FIG. 1
is a schematic diagram showing a fuel supply system according to Embodiment 1 of the present invention,
FIG. 2
is a schematic diagram showing details of the fuel supply system and
FIG. 3
is a sectional view showing the assembly structure of a high-pressure pump
31
and a high-pressure regulator
35
of a high-pressure fuel pump device
30
in the fuel supply system. In
FIG. 1
, the pump body
32
of the high-pressure pump
31
has a high-pressure valve connection portion
34
on the exterior side
33
including a high-pressure passage
42
on a pump side which is used to connect the high-pressure regulator
35
. The valve housing
36
of the high-pressure regulator
35
has a high-pressure pump connection portion
38
on the exterior side
37
including a high-pressure passage
43
on a valve side which is used to connect the high-pressure pump
31
. Those high-pressure connection portions are connected to each other to assemble the high-pressure pump
31
and the high-pressure regulator
35
together, thereby making it possible to standardize the pump body
32
and or the valve housing
36
. That is, in the high-pressure pump
31
, such elements as a pumping element
9
, an intake valve
39
corresponding to the above intake valve
10
, a discharge valve
40
corresponding to the above discharge valve
11
, a low-pressure passage
41
on a pump side corresponding to the low-pressure passage
14
on the second housing side and a high-pressure passage
42
on a pump side corresponding to the high-pressure passage
16
on the second housing side are incorporated in the pump body
32
without using the valve housing
36
. In the high-pressure regulator
35
, such elements as a valve and a valve seat which will be described later, a drain return passage
18
, a high-pressure passage
43
on a valve side corresponding to the first high-pressure passage
16
on the second housing side and a high-pressure passage
44
on a valve inlet side corresponding to the second high-pressure passage
17
on the second housing side are incorporated in the valve housing
36
without using the pump body
32
.
In this embodiment, the intake valve
39
is arranged in the low-pressure passage
41
on the pump side and the discharge valve
40
is arranged in the high-pressure passage
42
on the pump side. Although the intake valve
39
and the discharge valve
40
are illustrated as separate units, in the actual product, the intake valve
39
and the discharge valve
40
can be formed on a single reed valve plate. The high-pressure connection portion
34
is a circular hole which is depressed inward from the exterior side
33
of the pump body
32
and its diameter is set to a value larger than the diameter of the high-pressure passage
42
on the pump side. The high-pressure passage
42
on the pump side is open to the bottom of the high-pressure valve connection portion
34
. The high-pressure pump connection portion
38
is shaped like a cylinder projecting outward from the exterior side
37
and its outer diameter is set to a value slightly smaller than the diameter of the high-pressure valve connection portion
34
. The high-pressure passage
43
on the valve side is open to the bottom of the high-pressure pump connection portion
38
. The high-pressure passage
43
on the valve side is also open to an exterior side not used to connect the pump body
32
of the valve housing
36
. By mating the high-pressure valve connection portion
34
with the high-pressure pump connection portion
38
, the high-pressure passage
42
on the pump side and the high-pressure passage
43
on the valve side are connected to each other to form a single high-pressure passage. The high-pressure passage
44
on the valve inlet side branches off from the high-pressure passage
43
on the valve side. Such elements as the delivery pipe
1
, injectors
2
, engine
3
, drain return passage
18
, fuel tank
19
, low-pressure pump
20
, low-pressure pipe
21
, high-pressure pipe
22
, drain return pipe
24
and fuel
25
are identical to those of the prior art shown in FIG.
14
.
In
FIG. 2
, the pump body
32
has therein a pumping element
9
, a filter
45
provided in the low-pressure passage
41
on the pump side to remove foreign matter from the fuel
25
, a low-pressure damper
46
provided in the low-pressure passage
41
on the pump side at a downstream side of the filter
45
to absorb the pulsation of low-pressure fuel, a check valve
47
provided in the high-pressure passage
42
on the pump side, a buffer chamber
48
provided in the high-pressure passage
42
on the pump side at a downstream side of the check valve
47
, a resonator
51
which is a Helmholtz resonator comprising an orifice
49
connected to the buffer chamber
48
and a control chamber
50
, and a pump drain passage
54
for the pump pressure increasing unit
9
.
The resonator
51
reduces the amplitude of fuel pressure pulsation at the resonance frequency in the high-pressure passage
42
that is caused by the discharge pulsation of the pumping element
9
with resonance characteristics which are determined by the shape of the orifice
49
and the volume of the control chamber
50
.
A fuel pressure sensor
55
connected to the delivery pipe
1
monitors the pressure of fuel so that the proper amount of fuel is injected into the combustion chamber of the engine
3
at a valve opening time of the injector
2
even when the pressure of fuel is unstable at the start of the engine or even when the pressure of fuel is unstable due to the malfunction of the high-pressure regulator
35
. The output signal of the fuel pressure sensor
55
is supplied to an unshown engine control unit (ECU). The engine control unit carries out control for the injection of proper amount of fuel into the combustion chamber of the engine
3
based on the signal from the fuel pressure sensor
55
. This control will not be detailed here in because it is not the subject matter of Embodiment 1.
Reference numeral
56
in
FIG. 2
is a filter on the inlet side of the low-pressure pump
20
,
57
a low-pressure check valve arranged in the low-pressure pipe
21
,
58
a filter arranged in the low-pressure pipe
21
closer to the high-pressure fuel pump device
30
than the low-pressure check valve
57
,
59
a low-pressure return pipe connected to a low-pressure regulator
60
arranged in the low-pressure pipe
21
between the filter
58
and the high-pressure fuel pump device
30
and to the fuel tank
19
, and
61
a drain pipe connected to the pump drain passage
54
and to the fuel tank
19
. Fuel leaking from a space between the piston and the cylinder of the pumping element
9
is returned to the fuel tank
19
from the pump drain passage
54
through the drain pipe
61
.
In
FIG. 3
, denoted by
65
is a low-pressure pipe connection portion of the high-pressure pump
31
formed in the pump body
32
, which is formed as a circular hole depressed toward the inside of the pump body
32
from the same exterior side as the exterior side
33
and its diameter is set to a value larger than the diameter of the low-pressure passage
41
on the pump side which is open to the bottom of the low-pressure pipe connection portion
65
. The low-pressure pipe
21
shown in
FIG. 2
is connected to the low-pressure pipe connection portion
65
. The filter
45
is press fitted in the low-pressure passage
41
on the pump side through the low-pressure pipe connection portion
65
. Reference numeral
66
is a sealing member such as an O ring for preventing fuel from leaking from a gap between the high-pressure valve connection portion
34
on the pump side and the high-pressure pump connection portion
38
on the valve side. The above high-pressure regulator
35
may be of either a mechanical or electromagnetic type. In
FIG. 3
, a mechanical high-pressure regulator
351
is illustrated.
The structure of the high-pressure regulator
351
will be described herein under. Denoted by
67
is a cylindrical valve seat stored in a valve housing
361
corresponding to the above valve housing
36
in such a matter that it crosses the high-pressure passage
43
on the valve side,
68
a valve guide hole extending through the center of the valve seat
67
in an axial direction,
69
a high-pressure passage on the valve seat side extending through the wall of the valve seat
68
in such a manner that it is connected to the high-pressure passage
43
and crosses the valve guide hole
68
, and
70
an annular valve seat surface formed at an inner periphery where one end surface of the valve seat
67
intersects the valve guide hole
68
. Reference numeral
71
denotes a cylindrical filter inserted between the valve seat
67
and the valve housing
361
to remove foreign matter from fuel
25
(see
FIG. 2
) between the high-pressure passage
43
on the valve side and the high-pressure passage
69
on the valve seat side, and
72
a sealing member such as an O ring for preventing fuel from leaking from a gap between the valve seat
67
and the valve housing
361
.
Denoted by
73
is a valve,
74
a small-diameter portion projecting from the end portion of the valve
73
and arranged in the valve guide hole
68
,
75
an annular space formed by the small diameter portion
74
and the valve guide hole
68
to be communicated with the high-pressure passage
69
on the valve seat side,
76
a spool portion projecting from the end of the small-diameter portion
74
and inserted into the valve guide hole
68
in such a manner that it can move in an axial direction,
77
a spring support portion projecting from the end of the valve
73
and located outside the valve guide hole
68
,
78
a cylindrical valve seat holder surrounding the spring support portion
77
in such a manner that it can move, which is installed in the valve housing
361
in such a manner that it presses the valve seat
67
,
79
an outer space formed by the valve seat holder
78
and the valve housing
361
,
80
an inner space formed in the inside of the valve seat holder
78
,
81
a communication hole formed in the wall of the valve seat holder
78
to communicate the inner space
80
with the outer space
79
, and
82
a sealing member such as an O ring for preventing fuel from leaking from a space between the valve seat holder
78
and the valve housing
361
.
Denoted by
83
is a spring such as a coil spring which is inserted into the inner space
80
and whose one end is fixed to the spring support portion
77
,
84
a spring holder inserted into the inner space
80
to press the other end of the spring
83
,
85
a sealing member such as an O ring preventing fuel from leaking from a space between the spring holder
84
and the valve seat holder
78
,
86
a column projecting from the center of the side opposite to the spring
83
of the spring holder
84
,
87
a thread formed in the valve housing
361
which is open to out side of the valve housing
361
,
88
a cylindrical cap mated with the thread
87
, and
89
a cylindrical fixing portion projecting from the cap
88
.
The valve seat
67
fitted with the filter
71
and the sealing member
72
is inserted into the valve housing
361
, the valve
73
is inserted into the valve seat
67
, the valve seat holder
78
fitted with the sealing member
82
is inserted into the valve housing
361
, the springs
83
are inserted into the inside of the valve seat holder
78
, the spring holder
84
fitted with the sealing member
85
is inserted into the inside of the valve seat holder
78
, and the cap
88
is fastened to the thread
87
with the column
86
contained in the inside hole
90
of the cap
88
firmly fixes the valve seat
67
and the valve seat holder
78
in the valve housing
361
. Thereafter, by pressing the column
86
from the out side with an unshown tool, the force of the spring
83
to be applied to the valve
73
is controlled such that it is balanced with a predetermined pressure to be set by the high-pressure regulator
351
. In this state, a portion projecting outward from the valve housing
361
of the fixing portion
89
is deformed inward , whereby the column
86
and the fixing portion
89
are connected to each other.
Denoted by
91
is an end space which remains in front of the spool portion
76
in the valve guide hole
68
when the valve
73
is in contact with the valve seat surface
70
, and
92
a recessed portion formed at the bottom of the space for storing the valve seat
67
of the valve housing
361
. The diameter of the recessed portion
92
is set to a value smaller than the outer diameter of the valve seat
67
. The end space
91
and the recessed portion
92
form a single damper chamber
93
. The damper chamber
93
is filled with part of fuel
25
(see
FIG. 2
) from the high-pressure passage
69
on the valve seat side through a space between the valve guide hole
68
and the spool portion
76
. The characteristics of the spool portion
76
can be controlled by setting the volume of the damper chamber
93
and a clearance between the valve guide hole
68
and the spool portion
76
to appropriate values, thereby making it possible to suppress the unstable oscillation of the valve
73
. Since the volume of the damper chamber
93
is determined by such conditions as the mass of the valve
73
, the size of the clearance between the valve guide hole
68
and the spool portion
76
, and the spring force of the spring
83
, there is a case where the end space
91
does not exist.
Reference numeral
94
denotes a high-pressure pipe connection portion formed in the valve housing
361
, which is formed as a circular hole depressed toward the inside of the valve housing
361
from an exterior side opposite to the exterior side
37
and whose diameter is set to a value larger than the diameter of the high-pressure passage
43
on the valve side which is open to the bottom portion of the high-pressure pipe connection portion
94
. The high-pressure pipe
22
shown in
FIG. 2
is connected to the high-pressure pipe connection portion
94
. Reference numeral
95
is a tool hole formed in the cap
88
, which a fastening tool is fitted in to fasten the cap
88
. The drain return passage
18
is illustrated as being formed in the valve housing
361
in parallel to the high-pressure pipe connection portion
94
. In the actual product, if the drain return passage
18
is formed in the valve housing
361
such that it is directed perpendicularly to
FIG. 3
the high-pressure pipe
22
and the drain return pipe
24
are separated from each other, thereby making it easy to install the high-pressure pipe
22
and the drain return pipe
24
in the valve housing
361
.
X
1
signifies a flow direction of fuel from the low-pressure pipe
21
of
FIG. 2
to the low-pressure passage
41
on the pump side, X
2
a flow direction of fuel from the high-pressure passage
42
on the pump side to the high-pressure passage
43
on the valve side, X
3
a flow direction of fuel from the high-pressure passage
43
on the valve side to the high-pressure pipe connection portion
94
through the filter
71
, high-pressure passage
69
on the valve seat side and annular space
75
, and X
4
a flow direction of fuel from the annular space
75
to the drain return passage
18
through the space between the valve seat surface
70
and the valve
73
, inner space
80
, communication hole
81
and outer space
79
when the pressure of fuel in the high-pressure passage
69
on the valve seat side exceeds the predetermined value set by the high-pressure regulator
351
.
According to the structure of this embodiment, the high-pressure pump
31
incorporates in the pump body
32
such elements as the pumping element
9
, intake valve
39
, discharge valve
40
, low-pressure passage
41
on the pump side, high-pressure passage
42
on the pump side, filer
45
, low-pressure damper
46
, check valve
47
, buffer chamber
48
, resonator
51
, pump drain passage
54
and low-pressure pipe connection portion
65
and has the high-pressure connection portion
34
on the exterior side
33
of the pump body
32
for connecting the high-pressure regulator
351
. The high-pressure regulator
351
incorporates in the valve housing
361
such elements as the drain return passage
18
, high-pressure passage
43
on the valve side, high-pressure passage
44
on the valve inlet side, valve seat
67
, filter
71
, sealing member
72
, valve
73
, annular space
75
, valve seat holder
78
, outer space
79
, inner space
80
, communication hole
81
, sealing member
82
, springs
83
, spring holder
84
, sealing member
85
, cap
88
, damper chamber
93
and high-pressure pipe connection portion
94
and has the high-pressure pump connection portion
38
on the exterior side
37
for connecting the high-pressure pump
31
of the valve housing
361
. The sealing member
66
is fitted in the high-pressure pump connection portion
38
, and the pump body
32
and the valve housing
361
are fastened together by unshown bolts while the high-pressure valve connection portion
34
and the high-pressure pump connection portion
38
are mated with each other. The bolts are fastened at a position where they do not interfere with the elements of the high-pressure pump
31
and the elements of the high-pressure regulator
351
. Thereby, a space between the high-pressure valve connection portion
34
and the high-pressure pump connection portion
38
is sealed up by the sealing member
66
, the exterior side
33
and the exterior side
37
are placed one upon the other, and the high-pressure pump
31
and the high-pressure regulator
351
are assembled together.
Embodiment 2
In the above Embodiment 1, the high-pressure regulator
351
is of a mechanical type. As shown in FIG.
4
, the high-pressure pump
31
is of the same type as in the above Embodiment 1, and an electromagnetic high-pressure regulator
352
is used in conjunction with this high-pressure pump
31
.
FIG. 4
is a sectional view showing the assembly structure of the high-pressure pump
31
and the high-pressure regulator
352
of a high-pressure fuel pump device
30
according to Embodiment 2 of the present invention. In
FIG. 4
, the high-pressure pump
31
has a high-pressure connection portion
34
which is a circular hole connected to the high-pressure passage
42
on the pump side and a low-pressure pipe connection portion
65
on the exterior side
33
of the pump body
32
for connecting the high-pressure regulator
352
. The high-pressure regulator
352
has a cylindrical high-pressure connection portion
38
on the extension side
37
which connects the high-pressure pump
31
and includes the high-pressure passage
43
on the valve side in the valve housing
362
corresponding to the above valve housing
361
. A sealing member
66
is fitted in the high-pressure pump connection portion
38
, and the pump body
32
and the valve housing
362
are fastened together by unshown bolts while the high-pressure valve connection portion
34
and the high-pressure pump connection portion
38
are mated with each other, whereby the exterior side
33
and the exterior side
37
are placed one upon the other, and the high-pressure pump
31
and the high-pressure regulator
352
are assembled together. The bolts are fastened at a position where they do not interfere with the elements of the high-pressure pump
31
and the elements of the high-pressure regulator
352
like Embodiment 1.
The electromagnetic high-pressure regulator
352
will be described hereinafter. Reference numeral
100
denotes a filter storage chamber formed in the valve housing
362
in such a manner that it extends into the high-pressure passage
43
on the valve side from a horizontal direction,
101
a filter corresponding to the above filter
71
,
102
a valve seat corresponding to the above valve seat
67
,
103
a through hole formed in the center of the valve seat
102
,
104
a core whose end portion for holding the valve seat
102
is incorporated in the valve housing
362
,
105
an inner space surrounded by the filter storage chamber
100
, the filter
101
, the core
104
, the valve seat
102
and the valve housing
362
and connected to the filter storage chamber
100
and the through hole
103
,
106
a sealing member such as an O ring for preventing fuel from leaking from a space between the valve housing
362
and the core
104
,
107
a spherical valve corresponding to the above valve
73
,
108
a plunger whose end portion is inserted into the center of the core
104
in such a manner that it can move,
109
an annular inner space corresponding to the above inner space
80
and surrounded by the core
104
, the valve
107
and the plunger
108
,
110
an annular outer space corresponding to the above outer space
79
and surrounded by the valve housing
362
and the core
104
, and
111
a communication hole corresponding to the above communication hole
81
and formed in the wall of the core
104
.
Denoted by
106
is a sealing member such as an O ring for preventing fuel from leaking from a space between the core
104
and the valve housing
362
,
113
a bush inserted between the core
104
and the plunger
108
and movably supporting the plunger
108
with respect to the core
104
,
114
a cap made of a magnetic material,
115
a spring holder inserted into the inside hole
90
of the cap
114
and connected to the fixing portion
89
,
116
a spring such as a coil spring inserted between the spring holder
115
and the plunger
108
for urging the plunger
108
toward the valve
107
side so that the valve
107
contacts the valve seat surface of the valve seat
102
,
117
a nonmagnetic cylindrical guide coaxially mated with the core
104
and the cap
114
and movably supporting in its center hole a rear half portion of the plunger
108
projecting from the core
104
, and
118
a sealing member such as an O ring for preventing fuel from leaking from a space between the guide
117
and the cap
114
.
Reference numeral
119
represents a bobbin fitted onto the guide
117
,
120
a coil wound round the bobbin
119
, and
121
a magnetic cylindrical yoke surrounding the bobbin
119
and the coil
120
, whose both end portions are caulked to the peripheral portion of the core
104
and the peripheral portion of the cap
114
while the core
104
and the cap
114
support the bobbin
119
from both sides in an axial direction to prevent it from rattling. When electrical power is supplied to the coil
120
, a magnetic circuit is formed by the yoke
121
, the cap
114
, the plunger
108
and the core
104
, and the plunger
108
is urged toward the core
104
side magnetically. Since this magnetic urging force is the same in direction as the spring force of the spring
116
which is applied to the plunger
108
and changes according to a current supplied to the coil
120
, the unshown engine control unit can control the fuel pressure set by the high-pressure regulator
352
by changing the current to the coil
120
based on a signal from the fuel pressure sensor
55
shown in FIG.
2
. When the pressure of fuel applied to the valve
107
exceeds the value of the pressure determined by the total of the spring fore of the spring
116
and the magnetic force of the magnetic circuit while fuel
25
(see
FIG. 2
) is charged into the filter storage chamber
100
, the filter
101
, the inner space
105
and the through hole
103
from the high-pressure passage
43
on the valve side, the valve
107
moves in a direction to that it parts from the valve seat
102
. Part of the fuel
25
is drained into the drain return passage
18
from a space between the valve seat
102
and the valve
107
through the inner space
109
, the communication hole
111
and the outer space
110
, thereby controlling the pressure of high-pressure fuel
25
in the high-pressure passage
42
on the pump side and the high-pressure passage
43
on the valve side. Reference numeral
122
signifies a sealing member such as an O ring for preventing fuel from leaking from a space between the cap
114
and the spring holder
115
.
Embodiment 3
In the above Embodiment 1, the horizontal type mechanical high-pressure regulator
351
is used for the high-pressure pump
31
. As shown in
FIG. 5
, the high-pressure pump
31
is of the same type as in the above Embodiment 1, and a mechanical high-pressure regulator
351
is used vertically for this high-pressure pump
31
.
FIG. 5
is a sectional view showing the assembly structure of the high-pressure pump
31
and the high-pressure regulator
351
of a high-pressure fuel pump device
30
according to Embodiment 3 of the present invention. In
FIG. 5
, reference numeral
363
denotes a valve housing corresponding to the above valve housing
361
,
431
a high-pressure passage on the valve side corresponding to the high-pressure passage
43
on the valve side whose intermediate portion bends toward a horizontal direction from a vertical direction and whose horizontal portion contains the valve seat
67
, filter
71
and valve
73
. While the high-pressure pump connection portion
38
fitted with the sealing member
66
is mated with the high-pressure valve connection portion
34
, the pump body
32
and the valve housing
363
are fastened together by unshown bolts. The bolts are fastened at a position where they do not interfere with the elements of the high-pressure pump
31
and the elements of the high-pressure regulator
351
. Thereby, a space between the high-pressure valve connection portion
34
and the high-pressure pump connection portion
38
is sealed up by the sealing member
66
, the exterior side
33
and the exterior side
37
are placed on upon the other, and the high-pressure pump
31
and the high-pressure regulator
351
are assembled together.
Embodiment 4
In the above Embodiment 2, the horizontal type electromagnetic high-pressure regulator
352
is used for the high-pressure pump
31
. As shown in
FIG. 6
, the high-pressure pump
31
is of the same type as in the above Embodiment 1, and an electromagnetic high-pressure regulator
352
is used vertically for the high-pressure pump
31
.
FIG. 6
is a sectional view showing the assembly structure of the high-pressure pump
31
and the high-pressure regulator
352
of a high-pressure fuel pump device
30
according to Embodiment 4 of the present invention. In
FIG. 6
, reference numeral
364
denotes a valve housing corresponding to the above valve housing
361
, which has a high-pressure passage
431
on the valve side bending toward a horizontal direction from a vertical direction. The filter storage chamber
100
and the filter
101
are arranged in the corner portion of the high-pressure passage
431
on the valve side. While the high-pressure pump connection portion
38
fitted with the sealing member
66
is mated with the high-pressure valve connection portion
34
, the pump body
32
and the valve housing
364
are fastened together by unshown bolts. The bolts are fastened at a position where they do not interfere with the elements of the high-pressure pump
31
and the elements of the high-pressure regulator
352
. Thereby, a space between the high-pressure valve connection portion
34
and the high-pressure pump connection portion
38
is sealed up by the sealing member
66
, the exterior side
33
and the exterior side
37
are placed one upon the other, and the high-pressure pump
31
and the high-pressure regulator
352
are assembled together.
Embodiment 5
In the above Embodiments 1 to 4, the high-pressure pump
31
of the single standard pump body
32
and the high-pressure regulator
351
or
352
of the valve housing
361
,
362
,
363
or
364
are assembled together. As shown in
FIG. 7
, the same type pump body
321
is used in place of the pump body
32
of the high-pressure pump
31
and an electromagnetic high-pressure regulator
352
is used horizontally for the high-pressure pump
31
.
FIG. 7
is a sectional view showing the assembly structure of the high-pressure pump
31
and the high-pressure regulator
352
of a high-pressure fuel pump device
30
according to Embodiment 5 of the present invention. In
FIG. 7
, the above low-pressure pipe connection portion
65
is removed from the pump body
321
and the above low-pressure passage
41
on the pump side is open to the exterior side
33
.
A valve housing
365
is obtained by forming an extension portion
123
for covering the opening of the low-pressure passage
41
on the pump side on the top of above valve housing
362
, and the extension portion
123
has a low-pressure passage
124
on the valve side and a low-pressure pipe connection portion
125
corresponding to the above low-pressure pipe connection portion
65
.
In other words, a portion of the pump body
321
to which the low-pressure passage
41
on the pump side is open is the flat exterior side
33
and it forms a low-pressure valve connection portion
126
. The low-pressure passage
124
on the valve side is open to the exterior side
37
and the low-pressure pipe connection portion
125
is open to the exterior side to which the high-pressure pipe connection portion
94
is also open. A portion of the extension portion
123
to which the low-pressure passage
124
on the valve side is open is the flat exterior side
37
and if forms a low-pressure pump connection portion
127
. When the high-pressure valve connection portion
34
and the high-pressure pump connection portion
38
are mated with each other, the low-pressure passage
124
on the valve side and the low-pressure passage
41
on the pump side are also connected to each other to form a single low-pressure passage. The diameter of the low-pressure passage
124
on the valve side is set to a value smaller than the diameter of the low-pressure pipe connection portion
125
, and the low-pressure passage
124
on the valve side is open to the bottom portion of the low-pressure pipe connection portion
125
. The filter
45
is fitted in the low-pressure passage
124
on the valve side from the low-pressure pipe connection portion
124
. Reference numeral
128
is a sealing member such as an O ring for preventing fuel from leaking from a space between the low-pressure valve connection portion
126
and the low-pressure pump connection portion
127
.
While the high-pressure pump connection portion
38
fitted with the sealing member
66
and the high-pressure valve connection portion
34
are mated with each other and the low-pressure valve connection portion
126
fitted with the sealing member
128
and the low-pressure pump connection portion
127
are placed one upon the other, the pump body
32
and the valve housing
364
are fastened together by unshown bolts. The bolts are fastened at a position where they do not interfere with the elements of the high-pressure pump
31
and the elements of the high-pressure regulator
352
. Thereby, a space between the high-pressure valve connection portion
34
and the high-pressure pump connection portion
38
is sealed up by the sealing member
66
, a space between the low-pressure valve connection portion
126
and the low-pressure pump connection portion
127
is sealed up by the sealing member
128
, the exterior side
33
and the exterior side
37
are placed one upon the other, and the high-pressure pump
31
and the high-pressure regulator
352
are assembled together.
Embodiment 6
In the above Embodiment 5, the low-pressure pipe connection portion
125
is provided on the same side as the high-pressure pipe connection portion
94
. As shown in
FIG. 8
, the low-pressure pipe connection portion
125
is provided on an exterior side different from that of the high-pressure pipe connection portion
94
.
FIG. 8
is a sectional view showing the assembly structure of the high-pressure pump
31
and the high-pressure regulator
352
of a high-pressure fuel pump device
30
according to Embodiment 6 of the present invention. In
FIG. 8
, reference numeral
366
is a valve housing corresponding to the above valve housing
365
, and
1241
a low-pressure passage on the valve side corresponding to the above low-pressure passage
124
on the valve side, whose intermediate portion bends toward a horizontal direction opposite to the valve
107
and the filter
45
is press fitted into the horizontal portion of the low-pressure passage
1241
from the low-pressure pipe connection portion
125
.
Embodiment 7
In the above Embodiment 6, the low-pressure pipe connection portion
125
is provided on the exterior side opposite to the valve
107
. As shown in
FIG. 9
, the low-pressure pipe connection portion
125
is provided on an inclined exterior side different from that of the high-pressure pipe connection portion
94
.
FIG. 9
is a sectional view showing the assembly structure of the high-pressure pump
31
and the high-pressure regulator
352
of a high-pressure fuel pump device
30
according to Embodiment 7 of the present invention. In
FIG. 9
, reference numeral
367
denotes a valve housing corresponding to the above valve housing
366
, and
1242
a low-pressure passage on the valve side corresponding to the above low-pressure passage
1241
on the valve side, whose intermediate portion bends obliquely toward a side opposite to the valve
107
and the filter
45
is press fitted into the obliquely bent portion of low-pressure passage
1242
from the low-pressure pipe connection portion
125
.
Embodiment 8
In the above Embodiment 7, the low-pressure pump connection portion
127
is formed for the high-pressure pump
31
in the valve housing
367
in which the electromagnetic high-pressure regulator
352
is installed horizontally. As shown in
FIG. 10
, the low-pressure pump connection portion
127
is formed in a valve housing
368
in which the high-pressure regulator
352
is installed vertically.
FIG. 10
is a sectional view showing the assembly structure of the high-pressure pump
31
and the high-pressure regulator
352
of a high-pressure fuel pump device
30
according to Embodiment 8 of the present invention. In
FIG. 10
, the valve housing
368
is obtained by forming the extension portion
123
for covering the opening of the low-pressure passage
41
on the pump side on the top of the above valve housing
364
, and the extension portion
123
has the low-pressure passage
124
on the valve side and the low-pressure pipe connection portion
125
.
Embodiment 9
In the above Embodiment 5, the low-pressure pump connection portion
127
is formed in the valve housing
365
in which the electromagnetic high-pressure regulator
352
is installed horizontally with respect to the high-pressure pump
31
. As shown in
FIG. 11
, the low-pressure pump connection portion
127
and a drain return passage
181
corresponding to the above drain return passage
18
are formed in a valve housing
369
corresponding to the above valve housing
365
, and the drain return passage
181
is connected to the outer space
110
and to the low-pressure passage
124
on the valve side at a downstream side of the filter
45
, thereby making it possible to remove the drain return pipe
24
(see FIG.
2
).
FIG. 11
is a sectional view showing the assembly structure of the high-pressure pump
31
and the high-pressure regulator
352
of a high-pressure fuel pump device
30
according to Embodiment 9 of the present invention. In
FIG. 11
, the drain return passage
181
is formed in the inside of the valve housing
369
such that it is not open to the exterior side of the valve housing
369
and does not interfere with the high-pressure passage
43
on the valve side. Therefore, fuel
25
(see
FIG. 2
) drained from the high-pressure passage
43
on the valve side through a space between the valve seat
102
and the valve
107
is returned to the low-pressure passage
124
on the valve side at a downstream side of the filter
45
from the outer space
110
through the drain return passage
181
.
Embodiment 10
In the above Embodiments 1 to 9, the pump body
32
or
321
and the valve housing
36
,
361
,
362
,
363
,
364
,
365
,
366
,
367
,
368
or
369
are fastened together by unshown bolts. As shown in
FIGS. 12 and 13
, the low-pressure pipe
21
, the high-pressure pipe
22
, a valve housing
370
corresponding to the above valve housing
36
,
361
,
362
,
363
,
364
,
365
,
366
,
367
,
368
or
369
and a pump body
321
corresponding to the above valve body
32
or
321
are fastened together by bolts
130
, thereby making easy assembly work.
FIG. 12
is a top view showing the assembly structure of the high-pressure pump
31
, the high-pressure regulator
352
, the low-pressure pipe
21
and the high-pressure pipe
22
of a high-pressure fuel pump device
30
according to Embodiment 10 of the present invention, and
FIG. 13
is a sectional view cut on line A—A of FIG.
12
. In FIG.
12
and
FIG. 13
, reference numeral
131
is an adapter attached to the end of the low-pressure pipe
21
by welding or the like,
132
an adapter attached to the end portion of the high-pressure pipe
22
by welding or the like,
133
a sealing member such as an O ring for preventing fuel from leaking from a space between the adapter
131
and the low-pressure pipe connection portion
125
, and
134
a sealing member such as an O ring for preventing fuel from leaking from a space between the adapter
132
and the high-pressure pipe connection portion
94
on the valve side. While the high-pressure valve connection portion
34
and the high-pressure pump connection portion
38
fitted with the sealing member
66
are mated with each other, the low-pressure valve connection portion
126
fitted with the sealing member
128
and the low-pressure pump connection portion
127
are placed one upon the other, and the adapters
131
and
132
fitted with the sealing members
133
and
134
are inserted into the low-pressure pipe connection portion
125
and the high-pressure pipe connection portion
94
, respectively, the bolts
130
are screwed into unshown screw holes formed in the pump body
321
from unshown bolt insertion holes formed in the adapters
131
and
132
through unshown bolt insertion holes formed in the valve housing
370
, whereby the low-pressure pipe
21
, the high-pressure pipe
22
, the valve housing
370
and the pump body
321
are fastened together by the bolts
130
to be assembled together.
In the above Embodiments 5 to 10, the electromagnetic high-pressure regulator
352
is used. The mechanical high-pressure regulator
351
may be used in place of the high-pressure regulator
352
.
In the above Embodiments 1 to 10, the high-pressure valve connection portion
34
is recessed and the high-pressure pump connection portion
38
is projecting. The high-pressure valve connection portion
34
may be recessed and the high-pressure pump connection portion
38
may be projecting.
In the above Embodiments 5 to 10, the low-pressure valve connection portion
126
and the low-pressure pump connection portion
127
are flat. The low-pressure valve connection portion
126
may be recessed and the low-pressure pump connection portion
127
may be projecting, or the low-pressure valve connection portion
126
may be projecting and the low-pressure pump connection portion
127
may be recessed.
According to the first aspect of the present invention, since the high-pressure pump and the high-pressure regulator are assembled together by connecting the high-pressure valve connection portion of the pump body to the high-pressure pump connection portion of the valve housing, at least one of the pump body and the valve housing can be standardized. For example, when the pump body which is more complex and larger in size than the valve housing is standardized, a mechanical high-pressure regulator or an electromagnetic high-pressure regulator can be combined with a high-pressure pump of a single design with ease. Therefore, high-pressure pumps and high-pressure regulators may be mass-produced, and a high-pressure regulator of a mechanical or electromagnetic type and a high-pressure pump may be assembled together per application requirement, thereby making it possible to cut production cost.
According to the second aspect of the present invention, since the high-pressure valve connection portion and the high-pressure pump connection portion are connected to each other by mating, the high-pressure valve connection portion and the high-pressure pump connection portion serve to determine the assembly positions of the high-pressure pump and the high-pressure regulator, thereby making it easier to assemble the high-pressure pump and the high-pressure regulator together. If the outer diameter of the high-pressure pump connection portion and the outer diameter of the adapter provided at the end portion of the high-pressure pipe happen to be the same, even when the high-pressure pump whose internal structure is more complex than that of the high-pressure regulator is standardized, the high-pressure regulator or the high-pressure pipe can be connected to the standardized high-pressure pump.
According to the third aspect of the present invention, since the low-pressure connection portions are interconnected and the high-pressure connection portions are interconnected to assemble the high-pressure pump and the high-pressure regulator together, the low-pressure connection portion and the high-pressure pipe connection portion are removed from the pump body which is connected to the housing of the engine. Therefore, the standardization of the pump body becomes easier.
According to the fourth aspect of the present invention, since the low-pressure valve connection portion and the low-pressure pump connection portion are connected to each other face-to-face, even when the high-pressure valve connection portion and the high-pressure pump connection portion are connected to each other by mating, a tolerable dimensional error is absorbed by connection between the low-pressure valve connection portion and the low-pressure pump connection portion, thereby making it easier to assemble the high-pressure pump and the high-pressure regulator together.
According to the fifth aspect of the present invention, since the valve housing has a drain return passage for returning fuel to the low-pressure passage of the high-pressure pump, the drain return pipe between the fuel tank and the high-pressure regulator can be eliminated.
According to the sixth aspect of the present invention, since the drain return passage is connected to the low-pressure passage on a downstream side of the filter, if fuel flows back in the drain return passage, foreign matter contained in the fuel does not enter the regulator, thereby making it possible to prevent an operation failure caused by foreign matter on the valve seat surface.
According to the seventh aspect of the present invention, since the pump body and the valve housing are fastened together by bolts together with pipes connected to the valve housing, the bolt attachment holes for assembling the pump body and the valve housing together can serve as pipe connection holes, thereby making it possible to realize the pump body and the valve housing with a small number of holes.
Claims
- 1. A high-pressure fuel pump device comprising a high-pressure pump for increasing the pressure of fuel to a high level and a high-pressure regulator for controlling the pressure of fuel by draining part of the fuel discharged from the high-pressure pump, whereinthe pump body of the high-pressure pump has a high-pressure valve connection portion on the exterior side including a high-pressure passage which is used to connect the high-pressure regulator, the valve housing of the high-pressure regulator has a high-pressure pump connection portion on the exterior side including a high-pressure passage which is used to connect the high-pressure pump, and the high-pressure valve connection portion and the high-pressure pump connection portion are connected to each other to assemble the high-pressure pump and the high-pressure regulator; wherein the valve housing has a drain return passage for returning fuel to the low-pressure passage of the high-pressure pump; and wherein the drain return passage is connected to the low-pressure passage on a downstream side of a filter.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11-111876 |
Apr 1999 |
JP |
|
US Referenced Citations (6)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2689226 |
Aug 1997 |
JP |