JPH1144267A - Fuel supply pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the whole size of a fuel supply pump compact while securing the discharge amount of fuel required upon the start-up of engine by dividing a reed valve into two first and second units, and providing the first unit with an intake side movable valve element opening and closing an intake passage and the second unit with a discharge side movable valve element opening and closing a discharge passage. SOLUTION: A valve lamination body 24 opening and closing an intake passage 22 and a discharge passage 23 and being installed in a pump body 21 with a plunger 7 sliding reciprocally with the rotation of a cam 8 has first and second reed valves 26, 27 connected to both surfaces of a valve plate 25. The first reed valve 26 is provided with two intake side movable valve elements 26a and two discharge holes 24b while the second reed valve 27 is provided with two intake holes 24a and two discharge side movable valve elements 27a. Accordingly, without increasing the outer diameter of the body 24, two sets of the elements 26a, 27a can be provided, whereby a conventional bypass valve is dispensed to simplify a fuel passage in the body 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply pump such as a high-pressure fuel supply pump used for a direct injection internal combustion engine.

[0002]

2. Description of the Related Art FIG. 16 is an explanatory view showing an example of the structure of a conventional fuel supply pump. In the figure, a pump body 1 is provided with a fuel intake passage 2 and a discharge passage 3. Further, a bypass passage 4 is provided between the suction passage 2 and the discharge passage 3. A bypass valve 5 is provided in the middle of the bypass passage 4.

[0003] A cylinder 6 is connected to the pump body 1. A fuel pressurizing chamber 6 a communicating with the suction passage 2 and the discharge passage 3 is provided in the cylinder 6. In the cylinder 6, a plunger 7 that sucks fuel into the fuel pressurizing chamber 6a and discharges fuel from the fuel pressurizing chamber 6a.
Are slidably provided. The plunger 7 is reciprocally slid with respect to the cylinder 6 by rotation of a cam 8 as a driving means. The plunger 7 is urged toward the cam 8 by a spring 9. In the pump body 1, a valve stack 10 for opening and closing the suction passage 2 and the discharge passage 3 is provided.

FIG. 17 is a sectional view of the valve laminate 10 of FIG. In the figure, a valve stack 10 has a reed valve 11 and first and second valve holders 12 and 13 joined to both surfaces thereof, and is directly mounted on a cylinder 6. Further, the valve laminate 10 is provided with a suction hole 10 a communicating with the suction passage 2 and a discharge hole 10 b communicating with the discharge passage 3.

FIG. 18 shows the reed valve 11 of FIG.
FIG. 19 is a plan view showing the first valve holder 1 of FIG.
FIG. 20 is a plan view showing the second valve holder 13 of FIG.

The first and second valve holders 12 and 13 are provided with a suction hole 10a and a discharge hole 10b, respectively. The disc-shaped reed valve 11 sandwiched between the first and second valve holders 12 and 13 has a suction hole 1.
0a, a suction side movable valve body 11a that opens and closes, and a discharge hole 10b.
And a discharge side movable valve element 11b that opens and closes.
The first and second valve holders 12 and 13 have recesses 12a and 13 that allow the movable valve bodies 11a and 11b to open and close.
a is provided.

Next, the operation will be described. The plunger 7 is reciprocated in the cylinder 6 by the rotation of the cam 8. When the plunger 7 is lowered, the suction side movable valve body 11a opens the suction hole 10a, and the discharge side movable valve body 11b closes the discharge hole 10b, so that the fuel from the suction passage 2 flows into the fuel pressurizing chamber 6a. Will be introduced. When the plunger 7 is raised, the suction side movable valve body 11a closes the suction hole 10a and the discharge side movable valve body 11b
As a result, the discharge hole 10b is opened, and the fuel in the fuel pressurizing chamber 6a is discharged to the discharge passage 3.

Further, when the engine is started, the rotational speed of the cam 8 is extremely low, and the descending speed of the plunger 7 is also low. Is difficult. Therefore, when the engine is started, the bypass valve 5 is opened, and fuel flows from the suction passage 2 to the discharge passage 3 via the bypass passage 4.
Such a method is disclosed, for example, in Japanese Patent Application Laid-Open No. 7-83134.

[0009]

In the conventional fuel supply pump configured as described above, a bypass passage 4 and a bypass valve 5 are provided in the pump body 1 in order to discharge fuel when the engine is started. Therefore, the passage in the pump body 1 is complicated, which hinders miniaturization and cost reduction of the whole pump. Further, in order to provide the function of the bypass valve 5 to the movable valve bodies 11a and 11b of the reed valve 11, the reed valve 11 becomes large and the whole valve also becomes large.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and it is possible to reduce the overall size of a fuel while ensuring the required amount of fuel to be discharged when starting the engine. The aim is to obtain a feed pump.

[0011]

According to a first aspect of the present invention, there is provided a fuel supply pump having a pump main body having a fuel intake passage and a discharge passage, provided in the pump main body, and having a fuel passage between the suction passage and the discharge passage. A cylinder having a connected fuel pressurizing chamber, slidably provided in the cylinder, for sucking fuel from the suction passage into the fuel pressurizing chamber and discharging fuel from the fuel pressurizing chamber to the discharge passage. A plunger, a driving means for reciprocally sliding the plunger, a first reed valve provided in the pump body and provided with a suction-side movable valve body for opening and closing a suction passage, and a discharge valve provided in the pump body. It is provided with a second reed valve provided with a discharge side movable valve element that opens and closes a passage.

A fuel supply pump according to a second aspect of the present invention
A valve stack having a valve plate, a first reed valve joined to one side of the valve plate, and a second reed valve joined to the other side of the valve plate; A suction hole for sucking fuel from the passage to the fuel pressurizing chamber and a discharge hole for discharging fuel from the fuel pressurizing chamber to the discharge passage are provided, and the suction side movable of the first reed valve is provided. The suction hole is opened and closed by the valve body, and the discharge hole is opened and closed by the discharge side movable valve body of the second reed valve.

A fuel supply pump according to a third aspect of the present invention is
A valve stack in which a first valve holder for holding a first reed valve between itself and a valve plate and a second valve holder for holding a second reed valve between the valve plate and the valve plate are provided. It is.

According to a fourth aspect of the present invention, there is provided a fuel supply pump.
A recess for allowing the movement of the suction-side movable valve body is provided in the first valve holder, and a recess for allowing the movement of the discharge-side movable valve body is provided in the second valve holder.

According to a fifth aspect of the present invention, there is provided a fuel supply pump, comprising:
The valve plate is provided with two suction holes and two discharge holes, and the first reed valve has two suction-side movable valve bodies.
The second reed valve is provided with two discharge-side movable valve elements.

According to a sixth aspect of the present invention, there is provided a fuel supply pump comprising:
Two suction holes and one discharge hole having a diameter larger than these suction holes are provided in the valve plate, and two suction-side movable valve elements are provided in the first reed valve, and one suction valve is provided in the second reed valve. A discharge side movable valve element is provided, and a discharge hole of a valve plate is arranged between two intake side movable valve elements.

A fuel supply pump according to a seventh aspect of the present invention
The valve plate is made of the same material as the first and second reed valves.

The fuel supply pump according to the invention of claim 8 is:
The valve plate, the first reed valve, and the second reed valve have the same thickness.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 is an explanatory diagram showing a structure of a high-pressure fuel supply pump according to Embodiment 1 of the present invention. In the figure, a pump body 21 is provided with a suction passage 22 connected to a fuel tank (not shown) and a discharge passage 23 connected to an injector (not shown). Fuel in the fuel tank is supplied to the suction passage 22 by a low-pressure fuel supply pump (not shown). A cylinder 6 is connected to the pump body 1. A fuel pressurizing chamber 6 a communicating with the suction passage 2 and the discharge passage 3 is provided in the cylinder 6. In the cylinder 6, a plunger 7 that sucks fuel into the fuel pressurizing chamber 6a and discharges fuel from the fuel pressurizing chamber 6a is slidably provided.

The plunger 7 has a cam 8 as a driving means.
Is reciprocated with respect to the cylinder 6 by the rotation of. The plunger 7 is urged toward the cam 8 by a spring 9. A valve stack 24 for opening and closing the suction passage 22 and the discharge passage 23 is provided in the pump body 1.

FIG. 2 is a sectional view of the valve laminate 24 of FIG. In the figure, a valve laminate 25 includes a first reed valve between a valve plate 25, first and second reed valves 26 and 27 joined to both surfaces of the valve plate 25, and the valve plate 25. And a second valve holder 29 that sandwiches a second reed valve 27 between the first valve holder 28 and the valve plate 25, and is directly mounted on the cylinder 6. Have been.

The valve laminate 24 has two suction holes 24a and two discharge holes 24 penetrating the laminate.
b is provided. Suction passage 22 and discharge passage 23
Are the suction hole 24a and the discharge hole 24b in the pump body 21.
Are respectively connected to one end of the. The other ends of the suction hole 24a and the discharge hole 24b are connected to the fuel pressurizing chamber 6a, respectively.

FIG. 3 is a plan view showing the second valve holder 29 of FIG. 2, FIG. 4 is a plan view showing the second reed valve 27 of FIG. 2, and FIG. 5 is a plan view showing the valve plate 25 of FIG. FIG. 6 is a plan view showing the first reed valve 26 of FIG. 2, and FIG. 7 is a plan view showing the first valve holder 28 of FIG.

The disk-shaped valve plate 25 sandwiched in the center of the laminated body of the valve laminated body 24 is provided with two suction holes 24a and two discharge holes 24b, respectively. The first reed valve 26 has two suction holes 24.
two movable side valve bodies 26a for opening and closing the respective a.
Two discharge holes 24b are provided respectively. Second
The reed valve 27 is provided with two suction holes 24a and two discharge-side movable valve bodies 27a that open and close the two discharge holes 24b, respectively.

The first valve holder 28 is provided with a common recess 28a that allows the two suction holes 24a, the two discharge holes 24b, and the two suction-side movable valve bodies 26a to move at the same time. The second valve holder 29 is provided with a common concave portion 29a that allows the two suction holes 24a, the two discharge holes 24b, and the two discharge side movable valve bodies 27a to move at the same time.

Next, the operation will be described. The plunger 7 is reciprocated in the cylinder 6 by the rotation of the cam 8. When the plunger 7 is lowered, the two suction-side movable valve bodies 2
The two suction holes 24a are respectively opened by 6a, and the two discharge holes 24b are respectively closed by two discharge-side movable valve bodies 27a, so that the fuel from the suction passage 22 is introduced into the fuel pressurizing chamber 6a. . Also, plunger 7
When the pressure rises, the two suction holes 24a are closed by the two suction-side movable valve bodies 26a, and the two discharge holes 24b are respectively opened by the two discharge-side movable valve bodies 27a. The fuel inside is discharged to the discharge passage 23.

In such a fuel supply pump, the suction hole 2
4a and two discharge holes 24b, and two movable valve bodies 26a, 27a are also provided, so that the flow rate of fuel can be increased when the engine is started, even though the bypass valve is omitted. The required flow rate can be secured. In addition, the suction side movable valve body 26a is connected to the first reed valve 26, and the discharge side movable valve body 27a is connected to the second reed valve 26.
Of the movable valve body 2 without increasing the outer diameter of the valve stack 24.
6a and 27a can be provided two by two. Therefore,
By omitting the bypass valve, the fuel passage in the pump body 21 can be simplified and the whole can be downsized.

The two reed valves 26 and 27 are
Since it is sandwiched between the first and second valve holders 28 and 29 and the valve plate 25, the valve laminate 24
Is secured. Furthermore, since the first and second valve holders 28 and 29 are provided with concave portions 28a and 29a that allow the movable valve bodies 26a and 27a to open and close, the operations of the movable valve bodies 26a and 27a are stabilized. be able to.

The components of the valve laminate 24 may be made of the same material, for example, stainless steel (quenched and tempered stainless steel), so that sufficient corrosion resistance and fatigue strength can be ensured while reducing costs. Can be planned.

In the above example, two suction holes 24a and two discharge holes 24b are provided, but three or more holes may be provided.
Further, one suction hole and one discharge hole may be provided, and the diameter of each may be increased. However, providing a plurality of small-diameter suction holes and discharge holes, rather than providing one large-diameter suction hole and one discharge hole, makes the movable valve body smaller and improves the opening and closing operability.

Embodiment 2 Next, FIG. 8 is a sectional view of a valve stack of a fuel supply pump according to Embodiment 2 of the present invention. In the figure, a valve laminate 31 includes a valve plate 32 and first and second reed valves 26 and 27.
And a stacked body having first and second valve holders 28 and 29. The valve plate 32 is
It has the same thickness as the reed valves 26 and 27. In addition, the valve laminate 31 includes a 2 that penetrates the above laminate.
Two suction holes 31a and two discharge holes 31b are provided. Other configurations are the same as those of the first embodiment.

In such a fuel supply pump, since the thickness of the valve plate 32 is made the same as that of the reed valves 26 and 27, the thickness of the valve stack 31 can be reduced, and the whole can be downsized. it can.

Embodiment 3 Next, FIG. 9 is a sectional view of a valve stack of a fuel supply pump according to Embodiment 3 of the present invention. In the figure, a valve stack 33 includes a valve plate 34, first and second reed valves 35 and 36 joined to both surfaces of the valve plate 34, and a first reed valve between the valve plate 34. It is constituted by a laminated body having a first valve holder 37 for holding the first 35 and a second valve holder 38 for holding a second reed valve 36 between the first valve holder 37 and the valve holder 34. In addition, the valve laminate 33 includes a 2 that penetrates the above laminate.
One suction hole 33a and one discharge hole 33b are provided.

FIG. 10 is a plan view showing the second valve holder 38 of FIG. 9, FIG. 11 is a plan view showing the second reed valve 36 of FIG. 9, and FIG. 12 is a plan view showing the valve plate 34 of FIG. FIG. 13 is a plan view showing the first reed valve 35 of FIG. 9, and FIG. 14 is a plan view showing the first valve holder 37 of FIG.

The valve plate 34 has two suction holes 3
3a and one discharge hole 33b having a larger diameter than the suction hole 33a.
Are provided respectively. First reed valve 35
Are provided with two suction-side movable valve bodies 35a for opening and closing the two suction holes 33a, respectively, and a discharge hole 33b. The second reed valve 36 is provided with two suction holes 33a and one discharge-side movable valve body 36a that opens and closes the discharge holes 33b. Discharge side movable valve element 36a
Extends in a direction perpendicular to the suction-side movable valve body 35a.

The first valve holder 37 is provided with a communication hole 37a that allows the movement of the suction side movable valve body 35a and communicates the suction hole 33a and the discharge hole 33b. The second valve holder 38 has two suction holes 33.
a, one discharge hole 33b and a concave portion 38a that allows the movement of the discharge side movable valve element 36a are provided. Other configurations are the same as those of the first embodiment.

In such a fuel supply pump, since one discharge hole 33b is arranged between the two movable valve bodies 35a on the suction side, the outer diameter of the valve stack 33 is further reduced, and The size can be reduced.

Embodiment 4 FIG. In the first embodiment, the two reed valves 26 and 27 are connected to the valve laminate 24.
And mounted on the cylinder 6 as shown in FIG.
As shown in FIG. 5, a first reed valve 26 may be arranged on the inlet side of the suction passage 22 in the pump body 21, and a second reed valve 27 may be arranged on the outlet side of the discharge passage 23.

[0039]

As described above, according to the fuel supply pump of the first aspect of the present invention, the reed valve is divided into two parts, and the first reed valve is provided with the suction side movable valve element for opening and closing the suction passage. Since the second reed valve is provided with a discharge-side movable valve element that opens and closes the discharge passage, the flow rate of fuel passing through the reed valve can be increased without increasing the diameter of the reed valve. Therefore, it is possible to reduce the overall size while securing the required fuel discharge amount when starting the engine.

The fuel supply pump according to the second aspect of the present invention has a first
Since the second reed valve is joined to both sides of the valve plate to form a valve laminate, the structure can be simplified and the whole can be further downsized.

In the fuel supply pump according to the third aspect of the present invention, since the two reed valves are sandwiched between the first and second valve holders and the valve plate, the strength of the valve stack can be ensured. it can.

According to a fourth aspect of the present invention, there is provided a fuel supply pump, wherein a concave portion for allowing the movement of the suction-side movable valve body is provided in the first valve holder, and a concave portion for allowing the movement of the discharge-side movable valve body is provided. Since the movable valve body is provided in the second valve holder, the operation of the movable valve body can be stabilized.

According to a fifth aspect of the present invention, a fuel supply pump is provided with two suction holes and two discharge holes in a valve plate, a first reed valve having two suction-side movable valve bodies, and a second reed valve. Since the two discharge-side movable valve bodies are provided in the valve, the fuel flow rate can be secured without increasing the size of the movable valve body, and the opening and closing operability can be improved.

In the fuel supply pump according to the present invention, two suction holes and one discharge hole having a diameter larger than those of the suction holes are provided in the valve plate, and the first reed valve has two suction holes. Since the movable valve element is provided with one discharge-side movable valve element for the second reed valve, and the discharge hole of the valve plate is arranged between the two suction-side movable valve elements,
The valve stack can be further miniaturized.

In the fuel supply pump according to the seventh aspect of the present invention, the valve plate is made of the same material as the first and second reed valves.

In the fuel supply pump according to the present invention, the valve plate, the first reed valve and the second reed valve have the same thickness, so that the valve stack can be made thinner.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a structure of a fuel supply pump according to Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view of the valve laminate of FIG.

FIG. 3 is a plan view showing a second valve holder of FIG. 2;

FIG. 4 is a plan view showing a second reed valve of FIG. 2;

FIG. 5 is a plan view showing the valve plate of FIG. 2;

FIG. 6 is a plan view showing the first reed valve of FIG. 2;

FIG. 7 is a plan view showing the first valve holder of FIG. 2;

FIG. 8 is a sectional view of a valve stack of a fuel supply pump according to Embodiment 2 of the present invention.

FIG. 9 is a sectional view of a valve stack of a fuel supply pump according to Embodiment 3 of the present invention.

FIG. 10 is a plan view showing a second valve holder of FIG. 9;

FIG. 11 is a plan view showing a second reed valve of FIG. 9;

FIG. 12 is a plan view showing the valve plate of FIG. 9;

FIG. 13 is a plan view showing the first reed valve of FIG. 9;

FIG. 14 is a plan view showing the first valve holder of FIG. 9;

FIG. 15 is an explanatory diagram showing a structure of a fuel supply pump according to Embodiment 4 of the present invention.

FIG. 16 is an explanatory diagram showing an example of the structure of a conventional fuel supply pump.

FIG. 17 is a sectional view of the valve laminate of FIG. 16;

FIG. 18 is a plan view showing the reed valve of FIG. 17;

FIG. 19 is a plan view showing the first valve holder of FIG.

20 is a plan view showing the second valve holder of FIG.

[Explanation of symbols]

6 cylinder, 6a fuel pressurizing chamber, 7 plunger, 8
Cam (drive means), 21 pump body, 22 suction passage, 23 discharge passage, 24, 31, 33 valve laminate, 24a, 31a, 33a suction hole, 24b, 31
b, 33b Discharge hole, 25, 32, 34 Valve plate, 26, 35 First reed valve, 26a, 35a
Suction side movable valve body, 27, 36 second reed valve,
27a, 36a Discharge-side movable valve element, 28, 37 First valve holder, 28a, 29a, 38a Recess, 29,
38 Second valve holder.

Claims (8)

[Claims] A pump body having a fuel suction passage and a discharge passage; a cylinder provided in the pump body and having a fuel pressurization chamber connected between the suction passage and the discharge passage; A plunger slidably provided in the cylinder for sucking fuel from the suction passage into the fuel pressurized chamber and discharging fuel from the fuel pressurized chamber to the discharge passage; and reciprocatingly sliding the plunger. A driving means, a first reed valve provided in the pump body and provided with a suction-side movable valve body for opening and closing the suction passage;
And a second reed valve provided in the pump body and provided with a discharge-side movable valve element for opening and closing the discharge passage. 2. A valve stack comprising a valve plate, a first reed valve joined to one side of the valve plate, and a second reed valve joined to the other side of the valve plate, In the valve laminate,
A suction hole for sucking fuel from the suction passage into the fuel pressurizing chamber and a discharge hole for discharging fuel from the fuel pressurizing chamber to the discharge passage are provided, respectively. 2. The fuel supply pump according to claim 1, wherein the suction hole is opened and closed by a suction side movable valve body, and the discharge hole is opened and closed by a discharge side movable valve body of the second reed valve. 3. A valve stack comprising: a first valve holder for holding a first reed valve between the valve plate and a second valve; and a second valve for holding a second reed valve between the valve plate and the valve plate. The fuel supply pump according to claim 2, further comprising a holder. 4. The first valve holder is provided with a concave portion for allowing the movement of the suction-side movable valve body, and the second valve holder has a second concave portion.
4. The valve holder according to claim 3, wherein a concave portion for allowing movement of the discharge-side movable valve body is provided.
A fuel supply pump as described. 5. The valve plate has two suction holes and two suction holes.
The first reed valve has two suction-side movable valve bodies, and the second reed valve has two suction ports.
The fuel supply pump according to any one of claims 2 to 4, wherein two discharge-side movable valve bodies are provided. 6. The valve plate is provided with two suction holes and one discharge hole having a diameter larger than these suction holes, and the first reed valve has two suction-side movable valve bodies. The second reed valve is provided with one discharge-side movable valve element, and the discharge hole of the valve plate is disposed between the two suction-side movable valve elements. The fuel supply pump according to any one of claims 2 to 4. 7. The fuel supply pump according to claim 2, wherein the valve plate is made of the same material as the first and second reed valves. 8. The fuel supply pump according to claim 2, wherein the valve plate, the first reed valve, and the second reed valve have the same thickness. .