KR20050042081A - Fuel supply pump and tappet structure body - Google Patents

Abstract

A fuel supply pump with a large fuel discharge amount and a tappet structure body that are suitably used for a accumulated pressure-type fuel injection device that mechanically intensifies pressure. In a tappet structure body with a pass-through hole and a fuel supply pump with a spring seat, a penetration portion through which a lubricant or a fuel for lubrication passes is provided by cooperation of the tappet structure body and the spring seat. The penetration portion is provided between a spring-holding chamber for holding a spring used when a plunger is pulled down and a cam chamber for receiving a cam for lifting/lowering the plunger.

Description

FUEL SUPPLY PUMP AND TAPPET STRUCTURE BODY}

The present invention relates to a pump and a tappet structure for fuel supply. In particular, the present invention relates to a fuel supply pump and a tappet structure suitable for a accumulator type fuel injection device that mechanically boosts a large flow rate fuel, for example using a pressurizing piston.

Background Art Conventionally, in a diesel engine or the like, various accumulator fuel injection devices (Common Rail System: CRS) using accumulators (common rail) have been proposed in order to efficiently inject high-pressure fuel.

For example, in Japanese Unexamined Patent Application Publication No. 1994-93936, as shown in FIG. 25, in order to easily switch the pressure of the accumulator according to the operating conditions of the engine, the first accumulator responsible for main injection ( 236 and a second accumulator 278 which is responsible for pilot injection, respectively, and the switching device 286, the pressure accumulating fuel injector for switching the accumulators (236, 278) to perform fuel injection proposed It is.

Further, Japanese Patent No. 2885076 discloses a accumulator type fuel injector provided with a booster piston and a cylinder chamber for boosting fuel between an accumulator and a fuel injection valve for the purpose of obtaining an optimum injection pressure for engine performance. It is proposed.

More specifically, as shown in FIG. 26, the accumulator 395, the fuel supply flow path 360, the control flow path 361, the fuel injection control switching valve 362, and the boosting piston 378 Cylinder chamber 383 for accommodating water, pressure boosting piston 378 for raising fuel pressure to about 70 to 120 MPa (about 700 to 1200 kgf / cm 2), hydraulic circuit 363, and piston operation switching A accumulator type fuel injection device 380 having a valve (three solenoid valve for booster device) 364 and a controller (not shown) is disclosed.

However, in the accumulating fuel injector disclosed in Japanese Patent Laid-Open No. 1994-93936, it is necessary to include two kinds of accumulators and a switching device thereof, and therefore, a problem that the accumulator fuel injector is complicated and enlarged is found. It became. Moreover, in such a accumulator type fuel injection device, when the cam and plunger of a fuel supply pump are driven at high speed, since lubricating oil cannot freely flow between a spring holding chamber and a cam chamber, the said lubricating oil inhibits the operation of a plunger, and A problem has been found that the flow fuel cannot be sufficiently pressurized.

On the other hand, in the accumulator-type fuel injection device disclosed in Japanese Patent No. 2885076, a pressure pump is provided between the accumulator and the fuel injection valve, and is intended to multi-stage pressure injection, and supplies a high-pressure fuel to the accumulator. Is proposed, the pressure pump is a conventional pressure pump of the accumulator type fuel injection device, and there is no mention of a pressure pump for the purpose of supplying a large amount of high pressure fuel to the boosting piston.

Accordingly, the inventors of the present invention have conducted a thorough investigation, and thus, by providing a communication portion between the spring holding chamber and the cam chamber, the lubricating oil or the lubricating fuel can be freely moved, even when the cam and the plunger are driven at a high speed to sufficiently pressurize a large amount of fuel oil. I found that it can be handled.

That is, according to the present invention, the cam and the plunger in the fuel supply pump are driven at high speed so that even when the fuel discharge amount is increased, the lubricant or the lubricating fuel can sufficiently pressurize the fuel without inhibiting the operation of the plunger. It is an object to provide a fuel supply pump and a tappet structure suitable therefor.

Summary of the Invention

[1] According to the present invention, there is provided a fuel supply pump having a tappet structure and a spring seat, comprising: a spring holding chamber for holding a spring used when pulling down the plunger, and a cam chamber for accommodating a cam for raising the plunger; The fuel supply pump provided with the communicating part for passing lubricating oil or lubricating fuel in between is provided, and can solve the above-mentioned problem.

That is, when the plunger rises to pressurize the fuel, the lubricating oil or the lubricating fuel present in the spring holding chamber can move to the cam chamber quickly and smoothly via the communicating portion. On the other hand, when the plunger is lowered to suck the fuel, the lubricating oil or the lubricating fuel present in the cam chamber can move to the spring holding chamber quickly and smoothly via the communicating portion. Therefore, even when the plunger is driven at high speed by rotating the cam and plunger at high speed, for example, by rotating the cam at 1,500 rpm or more, the lubricant or lubricating fuel can freely travel between the spring holding chamber and the cam chamber. It is less likely that the fuel inhibits the high speed operation of the plunger, and a large amount of fuel can be pressurized.

[2] Further, in the fuel supply pump of the present invention, a spring holder for holding a spring used when the spring sheet pulls down the plunger of the fuel supply pump, and a plunger mounting portion for fixing the plunger At the same time, it is preferable that a passage hole for passing lubricating oil or a lubricating fuel is provided as a part of the communicating portion around the plunger mounting portion.

In such a configuration, even when the plunger is driven at a high speed, the lubricating oil or the lubricating fuel can flow more smoothly between the spring side and the cam side via the passage hole of the spring sheet.

[3] In the configuration of the fuel supply pump of the present invention, it is preferable to provide a plurality of passage holes in the spring sheet and to arrange the passage holes radially or semi-radially around the plunger mounting portion.

By such a configuration, a communication portion can be easily and reliably formed between the spring sheet and the tappet structure regardless of the assembling phase of the spring sheet.

[4] Further, in the construction of the fuel supply pump of the present invention, the tappet structure includes a roller and a roller body, and a passage hole for passing lubricating oil or lubricating fuel is provided in the roller body as part of the communication portion. It is desirable to have.

In such a configuration, even when the plunger is driven at a high speed, the lubricating fuel can flow more smoothly between the spring side and the cam side via the through hole of the roller body.

[5] Further, in the configuration of the fuel supply pump of the present invention, it is preferable to provide a plurality of passage holes in the roller body and to arrange the passage holes in the circumferential direction of the roller body.

By such a configuration, it is possible to easily and reliably form a communication portion between the tappet structure and the spring sheet, regardless of the assembly phase of the tappet structure.

[6] Further, in the fuel supply pump of the present invention, a passage hole for passing lubricating oil or lubricating fuel as a part of a communication part is provided in the roller body, and the passage hole as an upper surface of the roller body. It is preferable to provide a conduction path for passing lubricating oil or lubricating fuel at a location including an opening of the lubricating oil.

With this configuration, the communicating portion can be easily and reliably formed via the roller body regardless of the assembly phase of the tappet structure.

[7] Further, in the fuel supply pump of the present invention, a roller is provided with a passage hole for passing lubricant or a fuel for lubrication as part of the communicating portion, and includes an opening on the lower side of the passage hole. It is preferable to provide a conduction path for passing a lubricating oil or a lubricating fuel at a location.

With this configuration, the communicating portion can be easily and reliably formed via the roller body regardless of the assembly phase of the tappet structure.

[8] In the fuel supply pump of the present invention, it is preferable to employ a fuel lubrication system using a part of the fuel oil as the lubricating fuel, and at the same time, the communicating portion passes the lubricating fuel.

With such a configuration, even if the fuel to be pressurized in large quantities and the amount of lubricating oil amount as the lubricating component are partially mixed, since the same components, the purification efficiency of the exhaust gas does not decrease.

[9] In the fuel pump of the present invention, it is preferable to use the accumulator fuel injector for pressurizing a fuel having a flow rate per unit time of 500 to 1,500 liters / hour to a value of 50 MPa or more.

By using in such a accumulator fuel injection device, since the pressurization process of a large flow fuel can be performed easily, fuel injection can be performed easily by multi-stage pressure, Furthermore, the combustion efficiency in a fuel injection device can be improved. Can be.

In another embodiment of the present invention, there is provided a tappet structure including a roller and a roller body, wherein a through hole for passing lubricating oil or lubricating fuel through the roller body has a non-roller portion, for example, a side portion, from an upper surface portion of the roller body. In contrast, the tappet structure is provided so as to penetrate.

That is, when the plunger rises to pressurize the fuel, the lubricating oil or the lubricating fuel of the spring holding chamber can move to the cam chamber quickly and smoothly through a through hole not closed by the roller. On the other hand, when the plunger is lowered to suck the fuel, the lubricating oil or the lubricating fuel present in the cam chamber can move quickly and smoothly to the spring holding chamber via the passage hole provided in the roller body.

Therefore, in such a tappet structure, the cam and plunger are driven at a high speed by using the pump for fuel supply, for example, when the plunger is driven at a high speed by rotating the cam at a rotation speed of 1,500 rpm or more, the lubricating oil or the lubricating fuel is the cam and It is less likely to hinder the high speed operation of the plunger, and as a result, less seizure is generated between the cam shaft.

1 is a side view having a partial notch in the fuel supply pump of the present invention;

2 is a cross-sectional view of a pump for fuel supply of the present invention;

3A and 3B are a perspective view and a cross-sectional view of the housing, respectively;

4A and 4B are a perspective view and a side view of the plunger, respectively;

5 is a view provided to explain a fuel intake valve and a fuel discharge valve;

6 is a perspective view of a spring sheet,

7A to 7B are a plan view and a sectional view of the spring sheet, respectively;

8A to 8C are diagrams provided to explain the attachment structure of each plunger,

9A and 9B are views provided to explain a fuel intake valve;

10 is a sectional view of a fuel intake valve,

11 is a view provided to explain a system of a pressure booster fuel injection device of a mechanical boosting method;

12 is a view provided to explain the structure of a proportional control valve;

13 is a view provided to explain the structure of a pressure accumulating fuel injection device of a mechanical boosting method;

14 is a view conceptually illustrating a method for boosting fuel by a pressure accumulating fuel injection device of a mechanical boosting method;

15 is a view for explaining the injection timing chart of the high pressure fuel;

16A to 16C are views provided to explain the tappet structure;

FIG. 17 is a view provided to explain another tappet structure; FIG.

18 is a view provided to explain a separate tappet structure;

19 is a view provided to explain a separate tappet structure;

20 is a view provided to explain a separate tappet structure;

21 is a perspective view for explaining the roller body,

22A to 22B are views provided to explain the roller body, respectively;

23 is a view provided to explain a separate roller body,

24 is a view provided to explain a separate roller body,

25 is a view provided to explain the structure of a conventional accumulator fuel injection device;

It is a figure provided in order to demonstrate the structure of another conventional accumulator type fuel injection device.

[First Embodiment]

1 and 2, the fuel supply pump 50 provided with the specific spring seat 10 and the tappet structure 6, as illustrated in FIG. 1 and FIG. Plunger mounting portion 14 for mounting the spring holding portion 12 for holding the spring 68 used to pull down the plunger 54 of the pump 50 and the tip portion 55 of the plunger 54. At the same time, a through hole 16 is provided around the plunger mounting portion 14, and the tappet structure 6 includes the roller 29 and the roller body 28, and at the same time, the roller body 28 is provided. The passage hole 30b is provided in the fuel supply pump 50 in which the spring seat 10 and the tappet structure 6 cooperate with each other to form a communicating portion for passing lubricating oil or lubricating fuel.

Hereinafter, the fuel supply pump 50 will be described in detail by dividing it into configuration requirements and the like.

1. Basic form of pump for fuel supply

The basic form of the fuel supply pump is not particularly limited, but it is preferable to include a fuel supply pump 50 as shown in Figs. 1 and 2, for example. That is, the fuel supply pump 50 includes, for example, a pump housing 52, a barrel (cylinder) 53, a plunger 54, a spring seat 10, a tappet structure 6, and the like. It is preferable that the cam 60 be configured.

In addition, inside the barrel 53 accommodated in the pump housing 52, the plunger 54 reciprocates in response to the rotational movement of the cam 60, and the fuel compression chamber 74 for pressurizing the introduced fuel is provided. Formed.

Therefore, the fuel pumped from the supply pump 64 can be efficiently pressurized by the plunger 54 to the high pressure fuel in the fuel compression chamber 74.

In addition, in the example of this fuel supply pump 50, although a pair of barrels (cylinder) 53 and a plunger 54 are provided in the pump housing 52, for example, in order to process a large capacity fuel at high pressure, It is also preferable to increase the number by two or more pairs.

(1) pump housing

The pump housing 52 is a housing which accommodates the barrel (cylinder) 53, the plunger 54, the tappet structure 6, and the cam 60, as illustrated in FIGS. 1 and 2.

Therefore, such a pump housing 52 is provided with the shaft insertion passage hole 92a which opens to a left-right direction, and the circumferential spaces 92b and 92c which open to a vertical direction, respectively, as shown to FIG. 3A and FIG. 3B. It is preferable.

Moreover, as shown in FIG. 3B, it is preferable to further provide the through-holes 97 and 98 which open to the side direction of the circumferential space 92b, 92c in this pump housing 52. As shown in FIG. That is, the through holes 97 and 98 are formed of, for example, a stepped hole formed of three hole portions 97a to 97c and 98a to 98c having different apertures, and the hole portions 97a and The tip end of the guide pin 99 is press-fitted into 98a), and the precision of positioning of the guide pin is ensured. Further, the holes 97b and 98b have a function of guiding the tips of the guide pins 99 to the holes 97c and 98c in order to press the tips of the guide pins 99 into the holes 97c and 98c. . Moreover, it is preferable that the guide pin 99 is comprised as the screw part which screws the hole part 97a, 98a, and the tip part of the guide pin 99 is press-fitted by screwing.

(2) plunger barrel

1 and 2, the plunger barrel 53 is a housing for supporting the plunger 54, and a fuel compression chamber (pump chamber) for pressurizing a large amount of fuel at high pressure by the plunger 54. It is an element which comprises a part of (74). Therefore, it is preferable that the plunger barrel 53 is attached with respect to the upper opening part of the circumferential space 92b, 92c of the pump housing 52. As shown in FIG.

Moreover, when the kind of the fuel supply pump which installs a plunger barrel is an inline type and a radial type, the form of the plunger barrel can be changed suitably corresponding to each type.

(3) plunger

As illustrated in FIGS. 1 and 2, the plunger 54 is a main element for pressurizing the fuel in the fuel compression chamber 74 in the plunger barrel 53 at a high pressure. Therefore, it is preferable that the plunger 54 is arrange | positioned so that lifting and lowering is possible in the plunger barrel 53 attached to the circumferential space 92b, 92c of the pump housing 52, respectively.

Moreover, it is preferable that this plunger 54 has the press part 54a for entering and leaving inside the fuel compression chamber 74, as shown to FIG. 4 and FIG. The pressing portion 54a is designed to be thinner than the diameter of the flusher barrel 53, and when moving to a top dead center, it is preferable to form a gap between the pressing portion 54a and the discharge valve 79. . This is because the pressurizing portion 54a does not block the inlet of the discharge valve 79 and smoothly feeds the fuel to the common rail even after the plunger 54 is driven at a high speed to pressurize a large amount of fuel.

In addition, the plunger 54 is formed in the shape of a circular rod as a whole so that the plunger barrel 53 can be driven at a high speed smoothly, and has a flange portion 55 at an end opposite to the pressing portion 54a. It is preferable. That is, it is preferable that the fixing flange part 55 is integrally provided in the outer peripheral surface of the front-end | tip part (lower end part) of the cylindrical plunger 54. As shown in FIG. This is because it can be fixed easily and reliably with respect to the opening part 15 provided in the plunger attachment part 14 by this structure.

In addition, as shown in FIG. 2, the plunger 54 is always pressurized to the cam side by the plunger returning spring 68 and rises in response to the rotation of the cam 60. It is preferably configured to pressurize the fuel in 74).

Moreover, in the fuel supply pump of 1st Embodiment, it is preferable to drive a cam and plunger at high speed, and to pressurize a large amount of fuel. Specifically, it is preferable to make the rotation speed of such a cam and plunger into the value in the range of 1,500-4,000 rpm. Moreover, in consideration of the gear ratio, it is preferable to make the rotation speed of a cam and a plunger into the value within 1 to 5 times the engine rotation speed.

(4) fuel compression chamber

The fuel compression chamber 74 is a small room formed in the plunger barrel 53 together with the plunger 54 as shown in FIG. 2 and FIG. Therefore, in such a fuel compression chamber 74, the plunger 54 drives at high speed with respect to the fuel which flowed in quantitatively through the fuel supply valve 73, and can pressurize efficiently and a large amount. In addition, even when the plunger 54 is driven at high speed in this manner, a spring hole or a roller body, which will be described later, is provided with a through hole so that the lubricating oil or the lubricating fuel does not inhibit the high speed operation of the plunger 54. It is preferable that the through holes of are in communication.

On the other hand, after the pressurization by the plunger 54 is finished, the pressurized fuel is supplied to the common rail 106 shown in FIG. 11 via the fuel discharge valve 79. As shown in FIG.

(5) spring seat

As illustrated in Figs. 6, 7A and 7B, the spring seat 1 has a spring holder 12 for holding a spring which is used when pulling down the plunger of the fuel supply pump and fixing the plunger. In the spring seat 10 provided with the plunger mounting part 14 for this, it is preferable to provide the passage hole 16 for passing lubricating oil or lubrication fuel around the plunger mounting part 14.

(5) -1 spring holder

The shape of the spring holding part 12 is not particularly limited as long as it is possible to easily arrange the spring used when pulling down the plunger of the fuel supply pump, but, for example, as shown in FIG. It may be sufficient as it, or a planar body which partially protruded in the circumferential direction may be sufficient.

In addition, although not shown, it is also preferable to provide a structure in which a groove or a hook is provided in a portion of the spring holding portion to embed or fix a portion of the spring.

Moreover, regarding arrangement | positioning of the spring holding | maintenance part 12, it is preferable to provide around the plunger mounting part 14, as shown to FIG. 6, FIG. 7A, and FIG.

The reason for this is that by contacting the surface portion 13 of the spring holding portion 12 with a coil-shaped spring (not shown) used to pull the plunger down, the spring can be easily fixed and at the same time This is because it can be placed in the correct position.

(5) -2 plunger mounting

The shape of the plunger mounting portion is not particularly limited as long as it is a structure that can easily fix the plunger to pull down the plunger, but as shown in FIG. 7A, for example, as shown in FIG. 7A, the front end portion of the plunger is slidably inserted from the transverse direction. It is preferable to combine the large insertion hole 15b and the relatively small center hole 15a for fixing the tip of the plunger. That is, it is preferable to make the width | variety of the insertion opening 15b in the opening part 15 larger than the diameter of the center hole 15a of the opening part 15. As shown in FIG.

The reason for this is that the spring seat and the plunger can be easily fixed while being centered without further using a specific fastener. Therefore, in the fuel supply pump, even when the plunger is driven at a high speed, the positional shift between the tappet structure and the plunger can be reduced. 8A to 8C, the center hole of the opening portion 15 is provided after the flange portion provided at the distal end portion of the plunger 54 passes through the insertion opening 15b of the opening portion 15. It is because it is fixed to the back surface of the plunger attachment part 14, and does not come out in 15a.

Moreover, regarding the form of a plunger mounting part, it is also preferable to set it as the modification as shown to FIG. 8A-FIG. 8C.

Here, FIG. 8A is an example where the plunger attaching part 14 comprised in the dish shape was provided in the inner region of the spring holding part 12 so that the fuel storage part 16b may be formed. If comprised in this way, the step part 17 can be easily provided between the spring holding part 12 and the side surface of the plunger mounting part 14 as mentioned later. Therefore, even if the position of the passage hole 16 of the spring sheet 10 and the passage hole 30b of the roller body 28 slightly shifts, since the fuel storage part is formed in the meantime, even when the plunger is driven at high speed, The lubricating oil or the lubricating fuel freely travels, there is less interference with the high speed driving of the plunger, and at the same time, the predetermined lubricating effect can be effectively exhibited.

8B is an example in which the fuel reservoir 16b is not formed in the inner region of the spring holder 12, but the plunger mounting portion 14 is installed so that the plunger can be easily mounted. If comprised in this way, since the thickness of a spring sheet can be made thin, the handling and processing operation of a spring sheet can be made easy.

8C is an example in which the plunger mounting portion 14 is installed by extending the inner portion of the spring holding portion 12 as it is. If comprised in this way, the spring holding | maintenance part 12 and the plunger mounting part 14 can be made substantially flat shape, and handling and processing of a spring sheet can be made easy.

In addition, in the example shown to FIG. 8B and 8C, the position of the passage hole 16 of the spring sheet 10, and the position of the passage hole 30b of the roller body 28 match and communicate, and a plunger is driven at high speed. Even if it is made, the lubricating oil or the lubricating fuel will freely pass and there will be less interference with the high speed operation of the plunger, and the predetermined lubricating effect can be effectively exerted at each location.

In addition, regarding the arrangement of the plunger mounting portion 14, as shown in Figs. 6, 7A and 7B, it is preferable to provide the plunger mounting portion 14 in the inner region of the spring holding portion 12.

The reason for this is that the spring holding part 12 can hold, for example, a cylindrical spring, and can drive at high speed while fixing and centering the plunger easily in the inner region of the spring.

In addition, as shown in FIG. 7B, it is preferable to adjust the height of the plunger mounting portion 14 to provide a step 17 between the spring holder 12 and the side surfaces of the plunger mounting portion 14. 7B, the height of the stepped section 17 is indicated by the reference numeral t1.

This is because, with such a stepped portion, the spring can be disposed at the correct position and the tip portion of the plunger of the fuel supply pump can be easily accommodated.

Moreover, it is preferable to make height t1 of such a step part into 1 mm or more concretely.

(5) -3 through holes

Although the shape and number of the through holes 16 provided around the plunger mounting part 14 are not specifically limited, For example, it is preferable to provide the round through holes within 1-20.

This is because even if the number of such passage holes is one, for example, by considering the size and arrangement, the communication portion can be formed, and the lubricating oil or the lubricating fuel present in the spring holding chamber can be efficiently passed through the cam chamber. On the other hand, when the number of such passing holes exceeds 20, it may become difficult to arrange | position in a spring sheet or to form in a spring sheet may become difficult.

Therefore, it is more preferable to make the number of through holes into the value in the range of 2-15 pieces, and it is still more preferable to set it as the value in the range of 3-10 pieces.

In addition, it is preferable that the shape of the passage hole is substantially circular, but in addition, the shape of the passage hole is preferably an ellipse, a quadrilateral, a mold release, or a groove shape.

In addition, as shown in FIG. 6 and FIG. 7A, the passage hole 16 is preferably arranged radially or semi-radially around the plunger mounting portion 14. In the example of FIG. 6 and FIG. 7A, five through-holes 16 are arrange | positioned semi-radially with respect to the center point P of the plunger attachment part 14. As shown in FIG.

This is because the lubricating oil or the lubricating fuel can be passed more quickly through the through holes uniformly arranged in the spring sheet. In addition, it is because it becomes easy also to form, if it is arrangement | positioning of such a through hole. This is because, by arranging the through holes in this way, the limit of the attachment position of the plunger mounting portion is reduced.

However, as shown in FIG. 7A, when the plunger attachment portion is provided with an opening 15 for sliding the plunger front end portion from the transverse direction, the opening 15 is avoided and a plurality of passage holes are provided. It is preferable to arrange | position (16) semi-radially.

In addition, when the through hole 16 illustrated in FIG. 6 and FIG. 7A is substantially circular, it is preferable to make the diameter into the value within the range of 0.5-12 mm.

This reason is because when the diameter of such a passage hole becomes a value less than 0.5 mm, it may become difficult to pass lubricating oil or lubricating fuel quickly. Therefore, in the accumulator type fuel injection device using a piston booster (pressure booster piston) connected to such a fuel supply pump, it may be difficult to achieve a high pressure condition of 50 MPa or more, for example.

On the other hand, when the diameter of such a through hole exceeds 12 mm, it is because the mechanical strength of a spring sheet may fall, or durability may fall.

Therefore, it is more preferable to make the diameter of such a through hole into the value within the range of 1-10 mm, and it is still more preferable to set it as the value within the range of 1.5-6 mm.

Moreover, it is also preferable to change the diameter of a some through hole, respectively. This is because a relatively large diameter through-hole and a relatively small diameter through-hole are provided in a mixed manner so that the lubricant or the fuel for lubrication can be quickly passed through the large-diameter through-hole. On the other hand, by providing a passage hole with a relatively small diameter, the passage amount or passage speed of the lubricating oil or the lubricating fuel can be more precisely controlled, and the formation or arrangement of the passage hole with such a relatively small diameter reduces the restriction of the formation or arrangement. to be.

Therefore, as an example, it is preferable to provide a relatively large through hole having a diameter of 2.5 mm or more and a relatively small through hole having a diameter of less than 2.5 mm, respectively.

It is also preferable to provide a relatively large through hole having a diameter of 2.5 mm or more in the plunger mounting portion and a relatively small through hole having a diameter of less than 2.5 mm in the spring holding portion.

(6) tappet structure

The structure of the tappet structure is not particularly limited as long as the communication portion can be formed in cooperation with the spring sheet, but can be the same as the second embodiment described later. Therefore, the description here is omitted.

(7) cam

As illustrated in FIGS. 1 and 2, the cam 60 is a main element for changing the rotational motion of the motor to the vertical motion of the plunger 54 via the tappet structure 6. Therefore, it is preferable that the cam 60 is inserted and held rotatably through the bearing body to the shaft insertion hole 92a. And it is comprised so that it may rotate by the drive of the diesel engine (camshaft 3).

On the outer circumferential surface of this cam 60, two cam portions 3a and 3b, which are positioned below the circumferential spaces 92b and 92c of the pump housing 52 and parallel to each other at predetermined intervals in the axial direction, are integrally provided. It is preferable.

Moreover, it is preferable that such cam parts 3a and 3b are arranged in parallel at predetermined intervals in the circumferential direction.

(8) Valves for fuel intake and valves for fuel discharge

It is preferable to arrange the fuel intake valve and the fuel discharge valve as illustrated in FIG. 5 and to have a configuration as illustrated in FIGS. 9 and 10.

That is, it is preferable that the fuel intake valve 73 has the valve main body 19 and the valve body 20 which provided the flange part 20b in the front-end | tip as shown in FIG. Moreover, as shown in FIG. 10, this valve main body 19 has the cylindrical fuel suction chamber 19a which opens below, and the fuel suction hole 19b for injecting fuel into this fuel suction chamber 19a. Is preferably installed.

The fuel discharge valve 79 also preferably has a valve body and is housed in a part of the pump housing. It is preferable that the spring is always pressurized in the valve closing direction, and the fuel pressurized by the valve opening and the valve closing is supplied to the common rail.

9, the fuel intake valve 73 and the fuel discharge valve 79 include a valve body 19, a valve body 20 movably mounted therein, and a valve. The fuel suction chamber 19a provided in the main body 19, the fuel suction hole 19b, and the seat part 23 which the valve body 20 and a part of the valve main body 19 contact each other are provided, and the fuel suction is carried out. It is preferable to provide a plurality of holes 19b and to arrange the fuel suction holes 19b non-radially with respect to the fuel suction chamber 19a.

This is because such a fuel intake valve can supply the fuel supply pump very accurately and quantitatively even if the fuel flow rate is, for example, about 500 to 1,500 liters / hour.

In addition, similarly, the fuel discharge valve having such a configuration can supply the accumulator (common rail) very precisely and quantitatively even with a fuel having a flow rate per unit time of about 500 to 1,500 liters / hour, for example.

(9) lubrication system

In addition, the lubrication system of the pump for fuel supply is not particularly limited, but it is preferable to employ a fuel lubrication system that uses a part of the fuel oil as a lubricating component (lubricating oil fuel).

This is because when the cam and the plunger are driven at a high speed to pressurize a large amount of fuel, even if the sealing property is increased, a part of the fuel flowing out of the fuel pressurizing chamber and the lubricating component present in the spring holding chamber are mixed. It is because it may become easy. That is, by employing a fuel lubrication system, even if the fuel to be pressurized in a large amount and the amount of lubricating oil amount as the lubricating component are partially mixed, since the same component is used, the exhaust gas purifying property does not decrease while the lubricating component is waxed. This can be effectively prevented.

2. accumulator fuel injector

Moreover, it is preferable that the fuel supply pump of 1st Embodiment is a part of the accumulator type fuel injection device 100 of the mechanical pressure increase system which has the following structures.

That is, as illustrated in FIG. 11, the fuel supply pump 103 includes a fuel tank 102, a supply pump (low pressure pump) 104 for supplying fuel of such a fuel tank 102, and a fuel supply. Pump (high pressure pump) 103, common rail 106 as an accumulator for accumulating the fuel pumped from such fuel supply pump 103, piston booster (pressure boost piston) 108, and fuel It is preferable that it is comprised with the injection apparatus 110.

(1) fuel tank

The volume or shape of the fuel tank 102 illustrated in FIG. 11 is preferably determined in consideration of the fact that, for example, the flow rate per unit time can circulate fuel of about 500 to 1,500 liters / hour.

(2) Feed pumps, proportional control valves and pumps for fuel supply

As shown in FIG. 11, the supply pump 104 pumps fuel (via diesel) in the fuel tank 102 to the fuel supply pump 103, and the supply pump 104 and the fuel supply pump 103. It is preferable that the filter 105 is interposed between). The feed pump 104, although one example, preferably has a gear pump structure, is mounted to the end of the cam, and is driven via a gear, directly connected to the camshaft or via an appropriate gear ratio.

In addition, the fuel pumped from the feed pump 104 via the filter 105 further passes through a proportional control valve (FMU) 120 that executes injection amount adjustment as shown in FIG. Is preferably supplied. Such a proportional control valve 120 preferably controls the position of the anchor 125 proportionally by adjusting the amount of current flowing through the coil 124, for example, by control of an electronic control unit (ECU) to be described later. That is, by controlling the position of the piston 127 at the tip end of the anchor 125 in correspondence with the position of the anchor 125, between the slit 122 and the fuel supply unit 129 provided in the piston 127 The fuel passage area can be changed, and the fuel supplied to the intake valve (not shown) in the fuel supply pump 103 can be controlled.

In addition, as shown in FIG. 12, the fuel supplied from the supply pump 104 is paralleled with such a proportional control valve 120 in addition to being pumped to the proportional control valve 120 and the fuel supply pump 103. It is preferable to return to the fuel tank 102 via the overflow valve (OFV) 134 provided normally. In addition, it is preferable that some of the fuel is pumped to a bearing (not shown) of the fuel supply pump 103 via an orifice 136 mounted to the overflow valve 134 and used as fuel lubricating oil of the bearing. .

In addition, the fuel supply pump 103 is a device for pressurizing the fuel supplied from the supply pump 104 at a high pressure as described above. After pressurizing the fuel, the common rail 106 is passed through the high pressure passage 107. It is preferable that it is comprised so that it may be conveyed by.

(3) high pressure passage

In addition, as shown in FIG. 11, the one-way valve (not shown) is provided in the outlet of the fuel supply pump 103, the common rail 106 mentioned later, and the fuel supply pump 103. desirable.

This is because such a one-way valve can enable only liquid feed of fuel from the fuel supply pump 103 to the common rail 106. Therefore, backflow when the solenoid control valve is opened can be effectively prevented, and the pressure in the common rail 106 can be effectively prevented from falling.

(4) common rail

As shown in FIG. 11, a plurality of injectors (injection valves) 110 are connected to the common rail 106, and the fuel accumulated at high pressure by the common rail 106 is discharged from each injector 110. It is preferred to spray into an internal combustion engine (not shown). In addition, although each of these injectors 110 is not shown, it is preferable that the discharge amount is controlled via an injector driving unit (IDU). This IDU is connected to an electronic control unit (ECU) as a control device to be described later, and driven by the drive signal of the ECU.

Moreover, the pressure detector 117 is connected to the side end of the common rail 106, and it is preferable to transmit the pressure detection signal obtained by such a pressure detector 117 to ECU. That is, when the ECU receives the pressure detection signal from the pressure detector 117, it is preferable to control the electronic control valve (not shown) and to control the driving of the IDU according to the detected pressure.

(5) piston booster

Moreover, as a piston booster (pressure booster piston), as illustrated in FIG. 13, the cylinder 155, the mechanical piston 154, the pressurizing chamber 158, the solenoid valve 170, and the circulation path 157 are illustrated. At the same time, it is preferable that the mechanical piston 154 includes a pressure receiving portion 152 having a relatively large area and a pressing portion 156 having a relatively small area.

That is, the mechanical piston 154 accommodated in the cylinder 155 is pressurized and moved by the fuel having the common rail pressure in the hydraulic pressure section 152, and the common rail pressure of the pressure chamber 158, for example, about 30 MPa It is preferable to pressurize the fuel having a pressure by the press section 156 having a relatively small area, and to make the value within the range of 150 MPa to 300 MPa.

In addition, in order to pressurize the mechanical piston 154, although the fuel which has a common rail pressure is used in large quantities, it is preferable to return to a fuel tank etc. through the overflow valve 170 of an electromagnetic drive after pressurization. . That is, most of the fuel having the common rail pressure is pressurized by the mechanical piston 154, and then refluxed with the fuel discharged from the solenoid valve 180 of the fuel injection device to the fuel tank or the like, and the mechanical piston 154 is again returned. It is preferably used to pressurize.

On the other hand, the fuel boosted by the pressurizing unit 156 is fed to the fuel injection device (fuel injection nozzle) 163, efficiently injected, and burned.

Therefore, by providing the piston booster in this manner, the mechanical piston can be effectively pressed by the fuel having the common rail pressure without excessively increasing the common rail.

That is, as shown schematically in FIG. 14, the mechanical piston is provided with a relatively large area pressure receiving portion and a relatively small area pressing portion, while considering the stroke amount of the mechanical piston, the pressure loss is small, and the common rail pressure is reduced. It is possible to efficiently increase the fuel having a desired value. More specifically, the fuel from the common rail (pressure: p1, volume: V1, work volume: W1) is received by a hydraulic pressure part having a relatively large area, and by a mechanical piston provided with a pressure part having a relatively small area. High pressure fuel (pressure: p2, volume: V2, work volume: W2) can be used.

(6) fuel injector

(6) -1 basic structure

In addition, the form of the fuel injection device (fuel injection nozzle) 110 is not particularly limited, but, for example, as illustrated in FIG. 13, a mounting surface 164 on which the needle valve body 162 is mounted, and this mounting surface ( It is provided with the nozzle body 163 which has the injection hole 165 formed downstream rather than the valve body contact site | part of 164, and is supplied from the upstream side of the mounting surface 164 at the time of the lift of the needle valve body 162. FIG. It is preferable that it is the structure which guides fuel to the injection hole 165. FIG.

In addition, the fuel injection nozzle system 166 presses the needle valve body 162 toward the mounting surface 164 at all times by the spring 161 or the like, and energizes the needle valve body 162 to the solenoid 180. It is preferable that it is a solenoid valve type which opens and closes by a change of non-energization.

(6) -2 injection timing chart

Moreover, it is related with the injection timing chart of a high pressure fuel, and as illustrated in FIG. 15, it is preferable to show the fuel injection chart which has a two-stage injection state as shown by the solid line A. FIG.

The reason for this is that a combination of the common rail pressure and the pressure increase in the piston booster (increase piston) can achieve such a two-stage injection timing chart, thereby increasing fuel combustion efficiency and exhaust gas. Because it can purify.

Moreover, according to this invention, it is also preferable to show the fuel injection chart as shown by the dotted line B in FIG. 15 by the combination of a common rail pressure and the pressure increase in a piston booster (pressure boost piston).

In addition, when a piston booster (pressure boost piston) is not used, that is, the conventional injection timing chart becomes a low injection amount of one injection timing chart as indicated by the dotted line C in FIG.

(7) operation

Next, the operation of the fuel supply pump 103, the piston booster (pressure booster piston) 108 and the fuel injection valve 110 in the first embodiment will be described. That is, as shown in FIG. 11, during operation of the fuel injection device (fuel injection nozzle system) 166, the fuel of the fuel tank 102 is supplied from the supply pump 104 to the fuel supply pump 103. In addition, it is preferable to pressurize the high pressure fuel to the high pressure passage 107 from the fuel supply pump 103.

Subsequently, as shown in FIG. 13, it accumulates about 50 Mpa by the common rail 106, and the piston booster (pressure boost piston) 108 is provided between the fuel injection valve 110, for example, 150 It is preferable to pressurize on the high pressure conditions of MPa or more.

Second Embodiment

The second embodiment is a tappet structure 6 comprising a roller 29 and a roller body 28, as illustrated in FIGS. 16A-16C, which allows lubricant or fuel to pass through the roller body 28. Is a tappet structure 6 provided with a through hole 30b for penetrating from an upper surface portion of the roller body 28 to a non-roller portion. Hereinafter, the roller body 28 which has the basic structure of the tappet structure 6 and the through-hole 30b is demonstrated concretely, referring drawings suitably.

1. Basic Structure

The tappet structure 6 is basically composed of a shell 27, a roller body 28, and a roller 29, as shown in Figs. 16A to 16C. It is preferable that the cam shaft 3 and the cam 60 connected thereto are configured to move up and down. In addition, a modification of the tappet structure 6 including the shell 27 and the spring seat 10 in FIGS. 17 and 18, and a modification of the tappet structure 6 including the shell 27 in FIGS. 19 and 20. Although an example is shown, each can be used suitably.

Here, it is preferable that the shell 27 is formed as a cylindrical body which opens in an up-down direction and has an outer peripheral surface suitable for the peripheral surface of the circumferential spaces 92b and 92c of the pump housing 52 shown in FIG. Moreover, the opening part (slit part) 27a for guide pin insertion is provided in the upper part of the main wall of this shell 27, and is formed as a through hole extended in the axial direction of the shell 27. It is preferable. This is because when the tappet structure 6 moves up and down, the guide pins and the openings 27a cooperate to move up and down along the axes of the circumferential spaces 92b and 92c so that the operation direction of the tappet structure 6 does not shift. Because.

Moreover, it is preferable that the 1st protrusion part 27b for restricting the upward movement of the roller body 28 is provided in the inner peripheral surface of the shell 27. As shown in FIG. Moreover, it is preferable that the 2nd protrusion part 27c for guiding the outer periphery of the spring 68 is integrally provided in the inner peripheral surface of the shell 27. As shown in FIG. This is because the roller body 28 does not need to have a function of regulating the radial movement of the spring sheet 26, and the shape of the roller body 28 can be made simple.

On the other hand, it is preferable that the roller 29 is rotatably supported with respect to the roller bearing 30a in which carbon treatment, for example, a carbon coating film is given to the whole surface. The roller 29 is configured to receive the rotational force of the cam 60 in communication with the cam shaft 3. The reason for this is that by the carbon treatment applied to the roller bearing 30a, the contact movement state between the roller 29 and the roller bearing 30a can be controlled, and accordingly, the cam ( This is because the rotational force of 60 is transmitted to the roller bearing 30a which is a part of the roller body 28, and furthermore, it can be efficiently converted into the reciprocating motion of the plunger.

Therefore, with the tappet structure 6 configured as described above, it is possible to repeatedly and reciprocate at a high speed for a long time in response to the rotation of the cam 60 communicating with the cam shaft 3.

2. roller body

(1) basic composition

As shown in FIGS. 16A to 16C, the roller body 28 has a body main body 30, is mounted in the shell 27, and is formed by a block body having a planar circular shape made of a bearing steel as a whole. It is preferable that it is formed. In addition, although the modification of the roller body 28 is shown in FIGS. 21-24, each can be used suitably.

In addition, as shown in FIG. 16A, the body body 30 is provided with a roller bearing 30a having an inner circumferential surface suitable for the outer circumferential surface of the roller 29. Moreover, the contact part 30c with respect to the plunger 54 protrudes integrally in the upper surface center part of the main body 30. As shown in FIG. And it is preferable that the sheet | seat support part 30d which supports the spring seat 26 protrudes integrally in the peripheral part of this body main body 30.

(2) through hole

(2) -1 number and shape

The number or shape of the through holes provided in the roller body is not particularly limited, but it is preferable to provide, for example, 1 to 10 circular through holes.

This is because even if the number of such passage holes is one, for example, the spring and the lubricating oil or the lubricating fuel on the spring side can be efficiently transmitted to the cam side by considering the size and arrangement. On the other hand, when the number of such passing holes exceeds 10, it is because arrangement | positioning in a roller body may become difficult or formation may become difficult.

Therefore, it is more preferable to make the number of through holes into the value in the range of 2-8 pieces, and it is still more preferable to set it as the value in the range of 2-6 pieces.

In addition, when the passage hole is also provided for the spring sheet located above the roller body, the number of passage holes of the roller body is preferably equal to or less than the number of passage holes of the spring sheet.

In addition, it is preferable that the shape of the passage hole is substantially circular, but in addition, the shape of the passage hole is preferably an ellipse, a square, a mold release, or a groove shape.

(2) -2 batch

Moreover, it is preferable to arrange | position the through hole 30b provided in the roller body 28 radially around a roller body, as shown to FIG. 16B and FIG. In addition, in the example shown in FIG. 16B, two through holes 30b are arrange | positioned at the symmetrical position with respect to the center projection part 30c.

The reason for this is that the communication portion can be easily formed between the spring sheets regardless of the assembly phase of the tappet structure. Therefore, even a large amount of fuel can pass through the passage hole 30b as part of the communication portion more quickly.

This is because the arrangement of the passage holes facilitates the formation of the passage holes. In addition, since the through-holes are arranged in this way, the decrease in the mechanical strength of the roller body is also reduced.

In addition, with respect to the arrangement of the through holes 30b, as illustrated in FIGS. 16B and 21, the through holes 30b are obliquely passed from the upper surface portion of the roller body 28 to the non-roller portion, for example, the side portion. It is desirable to install so that.

This is because, when the through holes 30b are thus disposed, they are not closed by the operation of the rollers. Therefore, even when the cam and the plunger are driven at a high speed, the lubricating oil or the lubricating fuel can freely travel between the spring holding chamber and the cam chamber via these passage holes.

(2) -3 diameter

In addition, the diameter of the passage hole 30b illustrated in FIGS. 16B and 21 is preferably determined in consideration of the fuel passage amount per unit time or the like. However, when the passage hole 30b is substantially circular, the diameter is 0.5 to 12. It is preferable to set it as the value within mm range.

This is because when the diameter of the passage hole becomes a value less than 0.5 mm, it may be difficult to freely travel between the lubricating oil or the lubricating fuel. Therefore, it is because it is difficult to achieve high pressure conditions of 50 MPa or more, for example, in the accumulator type fuel injection device using a piston booster (pressure booster piston) connected to such a fuel supply pump.

On the other hand, when the diameter of such a passing hole exceeds 12 mm, it is because the mechanical strength of a roller body may fall, or durability may fall.

Therefore, it is more preferable to make the diameter of such a through hole into the value within the range of 1-10 mm, and it is still more preferable to set it as the value within the range of 2-6 mm.

(3) conduction path

In addition, as illustrated in FIGS. 21, 22A, and 22B, the above-mentioned through hole 30b is provided so as to penetrate through the non-roller portion from the upper surface portion of the roller body 28, and the roller body 28 is provided. As the upper surface portion of, it is preferable to provide a conductive path 33 for passing lubricating oil or lubricating fuel to a portion including an opening of the passage hole 30b.

The reason for this is that by forming the conductive path in this way, it is possible to effectively prevent the lubricating oil or the lubricating fuel from being stored in the upper surface portion of the roller body 28, and as a result, the lubricating oil or the lubricating fuel can be freed, and the cam and plunger This is because a large amount of fuel oil can be sufficiently pressurized even when the engine is driven at a high speed.

In addition, as illustrated in FIGS. 21, 22A, and 22B, the above-described passage hole 30b is provided so as to penetrate through the non-roller portion from the upper side portion of the roller body 28, and the passage hole 30b. It is preferable to provide a conductive path 35 for passing lubricating oil or lubricating fuel at a portion including an opening portion on the lower side of the side.

The reason for this is that by forming the conductive path in this way, the lower side of the roller body 28 can effectively prevent the lubricating oil or the lubricating fuel from being stored, and as a result, the lubricating oil or the lubricating fuel can freely move, thereby providing the cam and the plunger. This is because a large amount of fuel oil can be sufficiently pressurized even when driven at a high speed.

Therefore, by forming conductive paths in the vertical direction of the roller body, the cam and the plunger of the fuel supply pump are driven at high speed, so that even when the fuel discharge amount is increased, the lubricating oil or the lubricating fuel does not inhibit the operation of the plunger. Without this, the fuel can be sufficiently pressurized.

3. Contact surface

In addition, it is preferable that both the contact surfaces of the roller body and the plunger, or any one of the contact surfaces, have a curved structure.

Although not specifically shown, both or either of the contact surfaces of the contact surfaces of the roller body 28 and the plunger 54 shown in FIGS. 8A to 8C, for example, the curvature radius of the curved surface in the range of 30 mm to 2,000 mm It is preferable to set it as a structure.

The reason for this is that by adopting such a curved structure, even when the cam and the plunger are driven at a high speed, the unloading load between the plunger and the roller body can be prevented, the occurrence of sticking or breakage can be prevented, and the durability of the plunger can be improved. Because there is. That is, even when the cam and plunger in the fuel supply pump are driven at high speed in order to cope with the pressure-increasing pressure accumulating fuel injector, the durability of the plunger can be improved, and the fuel can be sufficiently pressurized. have.

As described above, according to the fuel supply pump of the present invention, by providing a predetermined communication portion, the lubricating oil or the lubricating fuel can be quickly and smoothly passed between the spring holding chamber and the cam chamber even at high speed driving of the plunger. . In particular, by cooperating the spring seat and the tappet structure having a specific passage hole, even a large amount of lubricating oil or lubricating fuel can be passed quickly and smoothly.

Therefore, the fuel supply pump of the present invention is used in the Amplified Piston Common Rail System (APRSS) in which the fuel is mechanically boosted by means of a piston or the like with a common rail, for example, a large flow fuel. It can use suitably as a pump for fuel supply used.

In addition, according to the tappet structure of the present invention, by providing a predetermined passage hole, the pressure pulsation caused by the high speed drive of the plunger is reduced, and a large amount of lubricating fuel can be passed quickly and smoothly.

Therefore, the tappet structure of the present invention, even when used in the fuel supply pump of the accumulator fuel injection device that mechanically boosts the large flow rate fuel, passes through a predetermined through hole, and a large amount of lubricating oil or lubricating fuel is provided between the spring side and the cam side. Since the lubricating oil or the fuel for lubrication can be freely traveled, it is possible to easily drive the plunger at high speed without disturbing the operation of the plunger.

Claims (10)

A fuel supply pump having a tappet structure and a spring seat, A communicating portion for passing lubricating oil or lubricating fuel is provided between a spring holding chamber for holding a spring used to pull down the plunger and a cam chamber for accommodating a cam for lifting and lowering the plunger. Fuel pump. The method of claim 1, A spring holding part for holding a spring used when the spring sheet pulls down the plunger of the fuel supply pump, and a plunger mounting part for fixing the plunger, and a part of the communicating part around the plunger mounting part. As a passage, a passage hole for passing lubricating oil or lubricating fuel is provided. Fuel pump. The method of claim 2, A plurality of the through holes are provided, and the through holes are arranged radially or semi-radially around the plunger mounting portion. Fuel pump. The method according to any one of claims 1 to 3, The tappet structure includes a roller and a roller body, and a passage hole for passing lubricating oil or lubricating fuel as part of the communicating portion is provided in the roller body. Fuel pump. The method of claim 4, wherein A plurality of through holes are provided in the roller body, and the through holes are arranged in the circumferential direction of the roller body. Fuel pump. The method according to claim 4 or 5, A passage hole for passing lubricating oil or lubricating fuel as part of the communicating portion is provided in the roller body, and the lubricating oil or lubricating fuel is passed to a position including an opening of the passage hole as an upper surface of the roller body. It is characterized by the installation of a through passage Fuel pump. The method according to any one of claims 4 to 6, A passage hole for passing lubricating oil or lubricating fuel is provided in the roller body at a location including an opening on the lower side of the passage hole while providing a passage hole for passing lubricating oil or lubricating fuel as part of the communicating portion. Characterized by Fuel pump. The method according to any one of claims 1 to 7, A fuel lubrication system employing a part of fuel oil as a lubricating fuel is employed, and the communicating portion passes the lubricating fuel. Fuel pump. The method according to any one of claims 1 to 8, Characterized in that the accumulator fuel injection device for pressurizing the fuel having a flow rate per unit time of 500 to 1,500 liters / hour to a value of 50 MPa or more Fuel pump. In a tappet structure comprising a roller and a roller body, A through hole for passing lubricating oil or lubricating fuel through the roller body is provided so as to penetrate from the upper surface portion of the roller body to the non-roller portion. Tappet structure.