JP2007278072A - Pump for fuel supply - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pump for fuel supply improving assembling property of a valve seat part in a fuel suction valve and excellent in reliability with respect to fuel leakage from the inside of a fuel pressurizing chamber. <P>SOLUTION: The pump for fuel supply comprises: the fuel pressurizing chamber disposed in a pump housing; the fuel suction valve fixed to the pump housing so as to supply the fuel to the fuel pressurizing chamber; and a plunger for pressurizing the fuel in the fuel pressurizing chamber. The fuel suction valve includes: a valve element; the valve seat part having a suction passage of fuel and a fuel reservoir chamber and slid with and holding the valve element; an urging means having one end fixed to the valve seat part and the other end fixed to the valve element so as to urge the valve element; and a holder part having a space part in which the urging means is housed and held so as to fix the fuel suction valve to the pump housing. The valve seat part and the holder part are integrally constituted. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel supply pump, and more particularly to a fuel supply pump used in a common rail system of an internal combustion engine.

Conventionally, in an internal combustion engine such as a diesel engine, pressure accumulation using a pressure accumulator (common rail) for the purpose of injecting uniform high-pressure fuel from a plurality of injectors in a timely manner and purifying exhaust gas Various fuel injection systems have been proposed.
An example of a fuel supply pump used in such an accumulator fuel injection system is shown in FIG. The fuel supply pump 410 includes a cam 429 in the pump housing 421 and a cylindrical space 421a in which a plunger barrel 415 is mounted above the cam 429, and above the plunger barrel 415 mounted in the cylindrical space 421a. A fuel intake valve 422 is attached to the opening. In addition, a fuel pressurization chamber 425 is formed inside the plunger barrel 415 by the plunger 423 and the fuel intake valve 422, and further, a portion facing the fuel pressurization chamber 425 is connected to the fuel discharge valve 428. A fuel passage 431 is provided. In the fuel supply pump 410, the fuel supplied to the fuel pressurizing chamber 425 through the fuel intake valve 422 is pressurized by the plunger 423 that reciprocates as the cam 429 rotates, and then the fuel discharge valve 428. It is pumped to the common rail via

Here, in the fuel intake valve 422, the valve body 407 is slidably held in a valve seat portion 405 having a fuel intake hole 474 and a fuel reservoir portion 476, and the valve seat portion 405 is connected to the screw plug 403. The fuel intake valve 422 is fixed to the plunger barrel 415 (see Patent Document 1). The fuel intake valve 422 is supplied with fuel to the fuel reservoir 476 through the fuel intake hole 474, and the difference between the pressure in the fuel pressurizing chamber 425 and the pressure in the fuel reservoir 476 exceeds a predetermined pressure value. In this case, the valve body is opened and fuel is supplied into the fuel pressurizing chamber 425. On the other hand, the pressure in the fuel reservoir 476 decreases, and the valve body is closed as the pressure in the fuel pressurizing chamber 425 increases as the plunger rises.
Japanese Patent Laid-Open No. 2004-21580 (FIG. 13)

However, the fuel intake valve disclosed in Patent Document 1 uses a material that is relatively difficult to deform in consideration of wear resistance as a constituent material of the screw plug, while a plunger barrel and a constituent material of the valve seat portion are used. In order to ensure the sealing performance at the sealing surface, a material that is relatively easily deformed is used. Therefore, the valve seat part and the screw plug are configured as separate members, and the shape of each part is complicated, and when assembling the plunger barrel, the screw plug is used while centering the valve seat part. There is a possibility that the work efficiency may be lowered and the arrangement accuracy of the valve seat portion may be lowered.
In particular, when the arrangement accuracy of the valve seat portion decreases, the pressure at the seal surface between the valve seat portion and the plunger barrel may vary, and fuel leakage from the fuel pressurizing chamber may occur. As a result, there is a case where a predetermined flow rate of fuel cannot be stably pumped.

Therefore, as a result of intensive studies, the inventors of the present invention have used such a fuel intake valve that is configured integrally with a valve seat portion and a holder portion as a fuel intake valve provided in a fuel supply pump. The inventors have found that the problem can be prevented and have completed the present invention.
That is, an object of the present invention is to provide a fuel supply pump that improves the assembly of the valve seat part and is excellent in reliability against fuel leakage from the fuel pressurizing chamber.

According to the present invention, a fuel pressurization chamber provided in the pump housing, a fuel intake valve fixed to the pump housing and for supplying fuel to the fuel pressurization chamber, and for pressurizing the fuel in the fuel pressurization chamber A fuel supply pump comprising a valve body, a valve body, a valve seat portion having a fuel suction passage and a fuel reservoir chamber and slidingly holding the valve body; An urging means for urging the valve body with the other end being fixed to the valve body and a space portion in which the urging means is accommodated and held and fixing the fuel intake valve to the pump housing A fuel supply pump comprising a valve seat part and a holder part integrally formed, and the above-described problems can be solved.
Note that “the valve seat portion and the holder portion are integrally configured” means that the valve seat portion and the holder portion are made of a single workpiece, and the number of parts constituting them is only one point.

  In configuring the fuel supply pump of the present invention, it is preferable that at least one of the receiving surface of the valve seat portion and the receiving surface of the pump housing at the contact portion between the valve seat portion and the pump housing is an inclined surface.

  In configuring the fuel supply pump of the present invention, it is preferable to interpose a gasket between the valve seat portion and the pump housing.

  In configuring the fuel supply pump of the present invention. Between the valve seat portion and the pump housing in the outer peripheral direction of the valve seat portion, there is a passage for fuel flowing into the suction passage of the valve seat portion and a gap as a fuel reservoir, and the holder portion It is preferable to provide a communication path connecting the parts.

  In configuring the fuel supply pump of the present invention, the integrated holder part and valve seat part are preferably made of a carburized material or bearing steel.

  In another aspect of the present invention, a fuel pressurization chamber provided in the plunger barrel, a fuel intake valve fixed to the plunger barrel for supplying fuel to the fuel pressurization chamber, and a fuel in the fuel pressurization chamber And a plunger for pressurizing the fuel, wherein the fuel intake valve has a valve body, a valve seat portion having a fuel intake passage and a fuel reservoir chamber and slidingly holding the valve body. A biasing means for biasing the valve body with one end fixed to the valve seat portion and the other end fixed to the valve body; and a space portion in which the biasing means is accommodated and held and a plunger for the fuel intake valve And a holder portion for fixing to the barrel, and a fuel supply pump in which the valve seat portion and the holder portion are integrally configured.

According to the fuel supply pump of the present invention, since the valve seat portion and the holder portion of the fuel intake valve are integrally configured, the valve seat portion can be accurately centered, and assembly performance is improved. The improvement can be achieved, and the pressure on the surface where the valve seat portion and the pump housing or the plunger barrel face each other can be made uniform to improve the sealing performance. Therefore, even when high pressure and high flow rate fuel is pumped, fuel leakage is unlikely to occur, and the fuel supply pump is excellent in reliability.
In addition, since the number of parts is reduced, a fuel supply pump with a simplified structure can be obtained, and the production cost of the fuel supply pump can be reduced.

Hereinafter, embodiments of the fuel supply pump of the present invention will be specifically described with reference to the drawings. However, this embodiment shows one aspect of the present invention and does not limit the present invention, and can be arbitrarily changed within the scope of the present invention.
In addition, what attached | subjected the same code | symbol in each figure has shown the same member, and description is abbreviate | omitted suitably.

[First Embodiment]
A first embodiment of the present invention includes a fuel pressurization chamber provided in a pump housing, a fuel intake valve fixed to the pump housing and for supplying fuel to the fuel pressurization chamber, and a fuel pressurization chamber. And a plunger for pressurizing the fuel.
The fuel intake valve used in the fuel supply pump of the present embodiment has a valve body, a valve seat portion that has a fuel intake passage and a fuel reservoir chamber, and slides and holds the valve body, and one end is fixed to the valve seat portion. And a biasing means for biasing the valve body with the other end being fixed to the valve body, and a holder part for fixing the fuel intake valve to the pump housing while having a space for accommodating and holding the biasing means The valve seat portion and the holder portion are integrally configured.

1. Basic Configuration of Fuel Supply Pump FIG. 1 and FIG. 2 show a fuel supply pump 10 according to this embodiment. Here, FIG. 1 is a perspective view of the fuel supply pump 10 with a part cut away, and FIG. 2A shows the fuel supply pump 10 of FIG. 1 along the axial direction of the crankshaft 31. FIG. 2B is a cross-sectional view in which a part is cut, and FIG. 2B is a cross-sectional view of the AA cross section in FIG.
The fuel supply pump 10 basically includes a feed pump 13 for pumping up fuel in a fuel tank, a pump body 20 that pressurizes and pumps fuel, and a fuel pressurization chamber 25 in the pump body 20. And a metering valve 17 for adjusting the amount of fuel to be supplied.
An example of the fuel supply pump 10 is a so-called radial pump in which cylinders of a pump housing are provided radially. Further, although three fuel pressurizing chambers 25 are provided in the pump housing 21, the number of fuel pressurizing chambers is not particularly limited, and may be two, or four or more. It doesn't matter. The fuel supply pump of this embodiment is suitable for use as a pump that pressurizes a large amount of fuel to a high pressure by driving the cam and plunger at a high speed by rotating the pump at a high speed.

2. Feed Pump The feed pump 13 is a part for pumping up fuel in a fuel tank (not shown) and transferring it to the metering valve 17. The feed pump 13 has a gear pump structure including, for example, a drive gear 33 attached to the end of the crankshaft 31 and a driven gear 35 connected to the drive gear 33. Directly connected to the shaft or driven through an appropriate gear ratio. When this feed pump 13 is driven, fuel is sucked from the fuel tank and transferred to the metering valve 17 using negative pressure.
A prefilter (not shown) is interposed between the feed pump 13 and a fuel tank (not shown). As a result, when foreign matters are mixed in the fuel in the fuel tank, the foreign matters can be primarily collected so as not to flow into the fuel supply pump 10.

3. Metering Valve The metering valve 17 is attached to the flange portion 11 as shown in FIG. 2B, and when the fuel transferred from the feed pump is transferred to the fuel pressurizing chamber 25 of the pump body 20, This is a part for adjusting the amount of fuel. This metering valve can be configured to use, for example, a proportional control valve. With such a metering valve, it is possible to adjust the fuel amount in accordance with the fuel pressure required by the internal combustion engine and send it to the fuel pressurizing chamber of the pump body.

4). Although not shown, it is preferable that the fuel supply pump includes an overflow valve that is branched from the middle of the fuel passage connecting the feed pump and the metering valve and is arranged in parallel with the metering valve. The reason for this is that if the pressure of the fuel transferred to the metering valve exceeds the specified value, or if the flow rate of the fuel transferred to the metering valve exceeds the specified value, the fuel tank is connected via the overflow valve. This is because it can be refluxed.
At this time, it is also preferable to transfer the fuel that has flowed to the overflow valve side into a cam chamber of a pump body, which will be described later, and use it as lubricating oil. This is because the fuel can be used effectively without separately supplying oil or the like as the lubricating oil in the cam chamber, and the fuel supply pump as a whole can be prevented from increasing in size and complexity.

5). General structure of the pump body (1) The pump body is a part for increasing the pressure of the fuel transferred through the metering valve and supplying it to the common rail or the like on the downstream side. As shown in FIGS. 1 and 2, the pump body 20 includes, for example, a pump housing 21, a fuel intake valve 22, a plunger 23, a spring 24, a tappet 27, a fuel discharge valve 28, and a cam 29. It can be set as the structure provided with.
The pump main body 20 is configured to pressurize the introduced fuel by reciprocating the plunger 23 corresponding to the vertical movement of the cam 29 accompanying the rotation of the crankshaft 31 in the cylindrical space 21c in the pump housing 21. A fuel pressurizing chamber 25 is provided. The fuel pressure-fed from the feed pump 13 through the metering valve 17 and the fuel intake valve 22 is increased in pressure by the plunger 23 in the fuel pressurizing chamber 25, and then the common rail or the like through the fuel discharge valve 28. Can be supplied to.

(2) Pump housing The pump housing 21 is a housing that houses the plunger 23, the tappet 27, the cam 29, and the like. For example, the pump housing 21 may include a shaft insertion hole 21a, a cam chamber 21b, and cylindrical spaces (cylinders) 21c to 21e that open radially around the cam chamber 21b. Further, the cylindrical spaces 21c to 21e of the pump housing 21 are elements constituting a part of the fuel pressurizing chamber 25 for pressurizing a large amount of fuel to a high pressure by the plunger 23.
The form of the pump housing including the number of cylindrical spaces can be changed as appropriate in accordance with the type of fuel supply pump.

(3) Plunger The plunger 23 is a part for increasing the pressure of the fuel in the fuel pressurizing chamber 25 in the plunger barrel 21. The plunger 23 is slidably disposed in the cylindrical spaces 21 c to 21 e of the pump housing 21 by the urging force of the spring 24 and the pushing force of the cam 29.
A spring seat (not shown) that receives the end of the spring 24 and pulls the plunger 23 toward the cam 29 by the urging force of the spring 24 can be locked to the end of the plunger 23.

(4) Fuel Pressurization Chamber The fuel pressurization chamber 25 is a small chamber formed in the pump housing 21 by the cylindrical spaces 21c to 21e, the plunger 23, and the fuel intake valve 22. In the fuel pressurizing chamber 25, a large amount of fuel that has flowed in via the fuel intake valve 22 can be pressurized by driving the plunger 23 at a high speed. In addition, after being pressurized by the plunger 23, the high-pressure fuel is supplied to the common rail or the like via the fuel discharge valve 28.

(5) Cam The cam 29 is a part for changing the rotational movement of the crankshaft 31 to the reciprocating movement of the plunger 23 via the tappet 27. The cam 29 is housed and held in the cam chamber 21b and presses the tappet 27 on the contact surface with the tappet 27 by rotating an eccentric cam shaft 31 having an outer periphery having a center of gravity at a position shifted from the rotation axis. A polygon ring 29A can be used. For example, when the number of fuel pressurizing chambers is three, the polygon ring may have a triangular shape as a whole, and when the number of fuel pressurizing chambers is two, the polygon ring may have a rectangular shape as a whole.
The configuration of the cam is not limited to the configuration using the eccentric drive shaft and polygon ring described above, and a triangular cam having three cam peaks or an elliptical cam having two cam peaks is used as the cam shaft. A fixed configuration may also be used.

(6) Tappet The tappet 27 is a member that is interposed between the plunger 23 and the cam 29 and reciprocates the plunger 23 in response to the vertical movement of the cam 29 as the crankshaft 31 rotates. The tappet 27 has a function of sliding inside the pump housing 21 and centering the plunger 23 and the cylindrical spaces 21c to 21e of the pump housing 21.
The configuration of the tappet 27 is not particularly limited, and may be a tappet structure including a tappet roller, for example.

(7) Fuel Intake Valve The fuel intake valve 22 is arranged at the outer end position of the cylindrical spaces 21c to 21e of the pump housing 21 and supplies the fuel transferred through the metering valve 17 to the fuel pressurizing chamber 25. It is a part to do. The fuel supply pump of the present invention is a fuel supply pump that is configured as a valve housing 80 by integrating a valve seat portion and a holder portion of a fuel intake valve.
Here, FIG. 3 shows an enlarged cross-sectional view of the vicinity of the fuel intake valve 22 in the fuel supply pump of the present embodiment (portion surrounded by a dashed line circle X in FIG. 2A). As shown in FIG. 3, the fuel intake valve 22 includes a valve body 37, a valve seat portion 81 that has a fuel intake path 74 and a fuel reservoir chamber 76 and slides and holds the valve body 37, and one end is a valve seat. A fuel intake valve having a spring 75 as an urging means for urging the valve body 37 with the other end fixed to the valve body 37 and a space 77 in which the spring 75 is housed and held. And a holder portion 83 for fixing 22 to the pump housing 21, and the valve seat portion 81 and the holder portion 83 are integrated to constitute a valve housing 80.
The state in which the other end of the urging means is fixed to the valve body is not limited to a state in which the urging means is directly fixed to the valve body, but is fixed to, for example, a spring seat fixed to the valve body. Including the state that has been.

Further, a seal ring groove 79 is provided on the outer peripheral surface of the holder portion 83 of the valve housing 80, and the seal between the holder portion 83 and the pump housing 21 is sealed by a seal ring 78 disposed in the seal ring groove 79. Is secured. Further, in order to ensure lubricity of the sliding surface of the valve element 37 in the space portion 77 of the holder portion 83, fuel as lubricating oil is filled, and a plug 85 is press-fitted from above the space portion 77. , Contain the fuel.
Further, in the outer peripheral direction of the valve seat 80 in the valve housing 80 (lateral direction in the figure), a passage for the fuel flowing into the suction passage 74 of the valve seat 81 is provided between the valve seat 81 and the pump housing 21. The gap 87 is provided. The gap 87 allows the fuel to be sucked from the suction passages 74 provided radially in the valve seat portion 81.

In such a fuel intake valve 22, the valve body 37 is normally urged in the valve closing direction by a spring 75, and the fuel transferred through the metering valve is a suction path formed with a gap 87 and a radial shape. When the difference between the pressure in the fuel pressurization chamber 25 and the pressure in the fuel sump chamber 76 exceeds a predetermined value, the valve is opened and the fuel is supplied to the fuel pressurization chamber. 25 is supplied. Thereafter, in the fuel pressurizing chamber 25, the pressure in the fuel pressurizing chamber 25 rises as the plunger 23 rises, and the fuel intake valve 22 is closed again.
At this time, the sliding surface between the valve body 37 and the valve seat portion slidably held by the valve seat portion 81 of the valve housing is located in the fuel reservoir 76 of the valve seat portion 81 or the space portion 77 of the holder portion 83. Fuel enters, ensuring lubricity and preventing seizure.

Here, the lower surface of the valve seat portion 81 is configured as a seal surface 81 a that is in contact with the edge surface of the cylindrical space 21 c of the pump housing 21, and is screwed to the pump housing 21 using the holder portion 83. The surface 81a is pressed against the pump housing 21 and has a sealing property. As a result, the fuel in the fuel pressurizing chamber 25 is prevented from seeping out from the gap between the pump housing 21 and the fuel intake valve 22.
In the fuel supply pump of the present invention, the valve seat portion 81 and the holder portion 83 of the fuel intake valve 22 are integrated as a valve housing 80, so that the arrangement accuracy of the valve seat portion 81 is improved. Therefore, the sealing performance of the portion is improved.

  More specifically, in the conventional fuel intake valve, as shown in FIG. 12, since the valve seat portion 405 and the holder portion 403 are formed as separate members, the fuel intake valve 422 is assembled to the plunger barrel 415. At this time, it is necessary to align the valve seat portion 405 with the inner cylinder of the plunger barrel 415 and fix the holder portion 403 by screwing. For this reason, in the assembling operation, when the alignment accuracy of the valve seat portion 405 is low, the pressure applied to the seal surface 405a on the lower surface of the valve seat portion 405 varies, and the high-pressure fuel in the fuel pressurizing chamber 425 leaks. There was a risk of getting out.

On the other hand, when the valve seat portion 81 and the holder portion 83 in the fuel intake valve 22 are integrated as a valve housing 80 as in the present invention, the valve housing 80 is fixed to the pump housing 21 by the holder portion 83. As a result, the position of the valve seat portion 81 is also uniquely determined, and no positional deviation in the axial direction occurs. Accordingly, it is possible to prevent the pressure applied to the seal surface on the lower surface of the valve holder portion 83 from being varied, and to prevent fuel leakage from the fuel pressurizing chamber 25. Therefore, the reliability against fuel leakage from the fuel pressurizing chamber 25 is improved, and high-pressure and large-flow fuel can be stably pumped.
Further, since the valve seat portion 81 and the holder portion 83 are integrated, when performing the assembly operation, the alignment operation of the valve seat portion 81 is not required, so that the assembly operation is efficiently performed. Will be able to. Furthermore, since the number of parts is reduced and the configuration is simplified, the total cost for producing the fuel supply pump can be reduced.

Further, regarding the sealing surface between the valve seat portion of the valve housing and the pump housing, as shown in FIG. 4, at least one of the receiving surface (seal surface 81a) of the valve seat portion 81 or the receiving surface 21A of the pump housing 21 is inclined. It is preferable that With this configuration, the contact area between the valve seat portion 81 and the pump housing 21 can be reduced, and the pressure applied to the seal surface 81a can be increased to improve the sealing performance.
On the other hand, as shown in FIG. 5, a gasket 89 is preferably interposed between the valve seat portion 81 of the valve housing 80 and the pump housing 21. If comprised in this way, it will become unnecessary to make the receiving surface (seal surface 81a) of the valve seat part 81 or the receiving surface 21A of the pump housing 21 into an inclined surface, and the sealing performance between the valve housing 80 and the pump housing 21 will be improved. This is because it can be easily improved.
Furthermore, at least one of the receiving surface (seal surface) of the valve seat portion or the receiving surface of the pump housing may be an inclined surface with a gasket interposed between the valve seat portion of the valve housing and the pump housing.

As shown in FIG. 3, the valve housing 80 in which the valve seat portion 81 and the holder portion 83 are integrated is such that the fuel goes back and forth between the space portion 77 of the holder portion 83 and the gap 87 through which the fuel passes. It is preferable to provide a communication path 90 that can be formed. By providing such a communication passage 90, when the fuel intake valve 22 is closed, the pressure in the space 77 can be released, and the movement of the valve body 37 can be made smooth, and the lubricating oil in the space 77 can be obtained. As a result, the fuel can be prevented from leaking from the sliding surface of the valve body 37 to the fuel reservoir chamber 76 and losing the lubricity of the valve body 37.
As shown in FIG. 6, the communication path may be a communication path 91 that connects the space portion 77 of the holder portion 83 and the suction passage 74 or the fuel reservoir chamber 76 of the valve seat portion 81. In order not to lower the mechanical strength of the integrated valve housing 80, it is more preferable to connect the space portion of the holder portion 83 and the gap 87 provided on the outer peripheral side of the valve seat portion 81. preferable.

In addition, the valve housing 80 in which the valve seat portion 81 and the holder portion 83 are integrally configured is preferably configured using a material that is relatively difficult to deform, such as a carburized material or bearing steel.
By using such a material, the mechanical strength of the valve housing can be increased and the wear resistance can be improved. Even when the entire structure is made of a hard material, as described above, the receiving surface of the valve seat portion of the valve housing or the receiving surface of the pump housing may be inclined or a gasket may be used. Thus, sealing performance can be ensured.

(8) Fuel Discharge Valve Further, the fuel discharge valve 28 shown in FIG. 2A is disposed on the side surface side of the fuel pressurizing chamber 25 in the cylindrical space 21c of the pump housing 21, and the high pressure fuel is used as a common rail or the like. It is a part for transferring.
For example, the fuel discharge valve 28 is configured such that when the valve body 37 is constantly urged in the valve closing direction by the spring 41 and the plunger 23 is pushed up by the cam 29 and the inside of the fuel pressurizing chamber 25 becomes high pressure, The valve can be opened by pressure to allow fuel to pass.

6). Flange part The flange part is a part for holding the pump body and fixing the pump body to the internal combustion engine. That is, in a state where the pump body is locked, the camshaft is connected to the crankshaft of the internal combustion engine in synchronization with the internal combustion engine via a gear or a coupling and fixed to the internal combustion engine.
Here, FIG. 7 shows a flange portion 11 used in the fuel supply pump 10 of FIGS. 1 and 2. In the example of FIG. 7, the flange portion 11 includes a first fuel passage 42 that guides the fuel flowing in from the first inlet portion 43 to the first outlet portion 44, and a fuel that flows in from the second inlet portion 48. A second fuel passage 46 that leads to a metering valve (not shown) inserted into the mounting hole 49 is provided. Further, in order to transfer the fuel whose flow rate is adjusted by the metering valve to each fuel intake valve (not shown) on the pump body (not shown) side, a third fuel passage 73, a circular flow passage 71, radial flow paths 72a to 72c are formed.

In such a flange portion 11, the fuel in the fuel tank sucked by the feed pump flows into the flange portion 11 from the first inlet portion 43, and is fed from the first outlet portion 44 via the first fuel passage 42. 13 is transferred. The fuel that has passed through the feed pump 13 flows into the flange portion 11 again from the second inlet portion 48 and is transferred to the metering valve via the second fuel passage 46. Next, the fuel transferred to the metering valve 49 is controlled in flow rate, and then flows through a plurality of radial flow paths via an annular flow path, from the third outlet portion to the fuel intake valve of the pump body portion. Sent.
By using the flange portion 11 having the fuel passages 42 and 46 inside as described above, it is not necessary to provide a separate fuel passage, so that the number of parts can be reduced and fuel leakage due to detachment of the fuel hose can be prevented. be able to.

7). Application Example of Fuel Supply Pump Further, the fuel supply pump of the present embodiment can be used as, for example, a pump that constitutes a pressure increasing type accumulator fuel injection device having the following configuration.
That is, as illustrated in FIG. 8, a fuel tank 53, a feed pump (low pressure pump) 13 for pumping up the fuel in the fuel tank 53, and a pump main body (high pressure pump) 20 that pumps the fuel at a high pressure are included. The fuel supply pump 10 is preferably composed of a common rail 61 as a pressure accumulator for accumulating fuel pumped from the fuel supply pump 10 and a plurality of fuel injection devices (injectors) 65. .

The volume and form of the fuel tank 53 illustrated in FIG. 8 are preferably determined in consideration of the ability to circulate fuel having a flow rate per unit time of about 200 to 1,500 liters / hour, for example.
The configuration of the common rail 61 is not particularly limited and can be used as long as it is a publicly known one. For example, a plurality of injectors 65 are connected to the common rail 61, and the common rail 61 has a high pressure. The pressure-accumulated fuel can be configured to be injected from each injector 65 into an internal combustion engine (not shown). With this configuration, fuel can be injected into the engine via the injector 65 at an injection pressure commensurate with the rotational speed without being influenced by fluctuations in the rotational speed of the engine.
In addition, a pressure detector 67 is connected to the side end of the common rail 61, and a pressure detection signal obtained by the pressure detector 67 is sent to an electronic control unit (ECU). And when ECU receives the pressure detection signal from the pressure detector 67, while controlling an electromagnetic control valve (not shown), it controls the drive of a proportional control valve according to the detected pressure.

The form of the injector 65 is not particularly limited. For example, a seating surface on which the needle valve body is seated, and an injection hole formed on the downstream side of the valve body abutting portion of the seating surface are provided. The nozzle body can be provided, and the fuel supplied from the upstream side of the seating surface can be guided to the injection hole when the needle valve body is lifted.
Further, such an injector 65 may be an electromagnetic valve type in which the needle valve body is always urged toward the seating surface by a spring or the like, and the needle valve body is opened and closed by switching between energization / non-energization of the solenoid. it can.
Further, a pressure increasing means can be provided so that the mechanical piston can be effectively pressed by the fuel having the common rail pressure at an arbitrary time without excessively increasing the size of the common rail.

The fuel flow in such a fuel supply system is shown in FIG.
As shown in FIG. 9, first, the fuel (light oil) in the fuel tank 53 is pumped up by the feed pump 13 and transferred to the metering valve 17. At this time, the foreign matter mixed in the fuel tank 53 is primarily collected by the pre-filter 51 interposed between the fuel tank 53 and the feed pump 13. The fuel pumped up by the feed pump 13 further collects foreign matter by the fuel filter 15 and then flows into the metering valve 17. Then, the fuel supplied from the metering valve 17 is sent to the three fuel pressurizing chambers 25 through the fuel intake valve 22 and, after being increased in pressure, is sent to the common rail 61 through the fuel discharge valve 28. It is done. At the same time, when the fuel amount or pressure flowing into the metering valve 17 exceeds a predetermined value, the fuel is recirculated to the feed pump 13 again via the overflow valve 19 while entering the cam chamber 21b of the pump body 20. It is sent as lubricating oil. The fuel that has passed through the cam chamber 21 b is returned to the fuel tank 53 together with the surplus fuel in the common rail 61.

  As described above, the fuel supply pump of the present embodiment increases the arrangement accuracy of the valve seat portion in the fuel intake valve even when used as a fuel supply pump of an accumulator fuel injection device. Even when high pressure and large flow rate fuel is pumped, fuel leakage from between the fuel intake valve and the pump housing can be prevented. Therefore, fuel can be stably supplied even when the high-pressure and high-speed operation is performed for a long time.

[Second Embodiment]
A second embodiment of the present invention includes a fuel pressurization chamber provided in the plunger barrel, a fuel intake valve fixed to the plunger barrel and for supplying fuel to the fuel pressurization chamber, and a fuel pressurization chamber. And a plunger for pressurizing the fuel.
In such a fuel supply pump, the fuel intake valve has a valve body, a valve seat portion that has a fuel intake passage and a fuel reservoir chamber and slides and holds the valve body, one end is fixed to the valve seat portion, and the like. An urging means for urging the valve body, the end of which is fixed to the valve body, and a holder part for fixing the fuel intake valve to the plunger barrel while having a space for accommodating and holding the urging means. The valve seat portion and the holder portion are integrally formed.

The fuel supply pump of this embodiment is shown in FIGS. FIG. 10 is a cross-sectional view in which the fuel supply pump 110 of this embodiment is partially cut away, and FIG. 11 is a cross-sectional view of the BB cross section in FIG.
As shown in FIGS. 10 and 11, the fuel supply pump 110 according to the present embodiment is the first embodiment in that the fuel intake valve 122 is fixed to the plunger barrel 115 instead of the pump housing 121. This is different from the fuel supply pump. The fuel supply pump 110 of this embodiment is a so-called column type pump in which the cylinders 121a and 121b of the pump housing 121 are provided in parallel.

  The fuel supply pump 110 includes a feed pump 113 for pumping fuel from a fuel tank (not shown), a metering valve 117 for adjusting the flow rate of fuel to be pressurized, a pump housing 121, and a pump housing 121. The plunger barrel 115 press-fitted into the cylindrical spaces 121a and 121b, the plunger 123 slidably held in the inner space of the plunger barrel 115, the spring seat 119 locked to the end of the plunger 123, and the plungers at both ends A spring 124 fixed to the barrel 115 and the spring seat 119 and arranged between the plunger 123 and the cam 129 for biasing the plunger 123 downward, and a tappet structure for pushing up the plunger 123 as the cam 129 rotates. And a body 127. A fuel intake valve 122 is disposed and fixed above the internal space of the plunger barrel 115, and a fuel discharge valve 128 is disposed and fixed via a fuel passage extending from the internal space of the plunger barrel 115.

A part of the inner space of the plunger barrel 115 forms a fuel pressurizing chamber 125 surrounded by the inner peripheral surface of the plunger barrel 115, the plunger 123 and the fuel intake valve 122, and is supplied via the fuel intake valve 122. In the fuel pressurizing chamber 125, the fuel to be pressurized is increased in pressure by the plunger 123 in response to the rotational movement of the cam 129 and is pumped to the downstream common rail or the like via the fuel discharge valve 128.
In this example of the fuel supply pump 110, two plunger barrels 115 are provided in the pump housing 121. However, in order to process a larger volume of fuel at a high pressure, the number may be increased to two or more. it can.

Here, the fuel supply pump 110 of the present embodiment is a fuel supply pump characterized in that the valve seat portion 181 and the holder portion 183 in the fuel intake valve 122 are integrated into a valve housing 180. is there.
By integrating the valve seat portion 181 and the holder portion 183 in this manner, the relative position between the valve seat portion 181 and the plunger barrel 115 of the valve housing 180 can be accurately determined, and the pressure applied to the contact surfaces varies. Can be prevented. Therefore, the fuel in the fuel pressurizing chamber 125 can be prevented from leaking from between the valve housing 180 and the plunger barrel 115, and a highly reliable fuel supply pump can be provided.
In addition, the configuration of the fuel intake valve can be variously modified in the same manner as already described in detail in the first embodiment.

It is a partial notch figure which shows the whole structure of the pump for fuel supply which concerns on 1st Embodiment. It is sectional drawing of the pump for fuel supply which concerns on 1st Embodiment. It is an expanded sectional view of a fuel intake valve. It is a figure which shows the state which made the receiving surface of the pump housing inclined. It is a figure which shows the state which has arrange | positioned the gasket between the fuel supply valve and the pump housing. It is a figure which shows another example of arrangement | positioning of a communicating path. It is a figure provided in order to demonstrate a flange part. It is a figure provided in order to demonstrate the system of a pressure accumulation type fuel injection device. It is a figure provided in order to demonstrate the flow of the fuel in the fuel supply system to which the pump for fuel supply of a 1st embodiment is applied. It is a partial notch figure which shows the whole structure of the fuel supply pump which concerns on 2nd Embodiment. It is sectional drawing of the pump for fuel supply which concerns on 2nd Embodiment. It is a figure provided in order to demonstrate the structure of the fuel intake valve in the conventional fuel supply pump.

Explanation of symbols

10: Fuel supply pump, 11: Flange, 13: Feed pump, 15: Fuel filter, 17: Metering valve, 19: Overflow valve, 20: Pump body, 21: Pump housing, 21b: Cam chamber, 22: Fuel intake valve, 23: plunger, 24: spring, 25: fuel pressurizing chamber, 27: tappet, 28: fuel discharge valve, 29: cam, 31: crankshaft, 33: drive gear, 35: driven gear, 37: Valve body, 42: first fuel passage, 43: first inlet portion, 44: first outlet portion, 46: second fuel passage, 48: second inlet portion, 49: second outlet portion, 51: prefilter, 53: Fuel tank, 61: Common rail (accumulator), 65: Fuel injection device, 74: Suction passage, 75: Spring, 76: Fuel reservoir, 77: Space part, 78 Seal ring, 79: Seal ring groove, 80: Valve housing, 81: Valve seat part, 81a: Seal surface, 83: Holder part, 85: Plug, 87: Gap, 89: Gasket, 90/91: Communication path, 110 : Fuel supply pump, 115: Plunger barrel, 119: Spring seat, 121: Pump housing, 122: Fuel intake valve, 123: Plunger, 124: Spring, 125: Fuel pressurizing chamber, 128: Fuel discharge valve, 129: cam

Claims (6)

A fuel pressurization chamber provided in the pump housing; a fuel intake valve fixed to the pump housing for supplying fuel to the fuel pressurization chamber; and a plunger for pressurizing fuel in the fuel pressurization chamber; In a fuel supply pump comprising:
The fuel intake valve includes a valve body, a valve seat portion that has a fuel intake passage and a fuel reservoir chamber, and slides and holds the valve body, one end of which is fixed to the valve seat portion, and the other end of the valve seat portion. An urging means for urging the valve body fixed to the valve body; a holder portion for fixing the fuel intake valve to the pump housing while having a space in which the urging means is housed and held; With
A fuel supply pump, wherein the valve seat portion and the holder portion are integrally formed.   2. The fuel supply according to claim 1, wherein at least one of a receiving surface of the valve seat portion or a receiving surface of the pump housing at a contact portion between the valve seat portion and the pump housing is an inclined surface. pump.   The fuel supply pump according to claim 1, wherein a gasket is interposed between the valve seat portion and the pump housing.   Between the valve seat portion and the pump housing in the outer peripheral direction of the valve seat portion, there is a gap as a passage for fuel flowing into the intake passage of the valve seat portion, and the holder portion is The fuel supply pump according to any one of claims 1 to 3, further comprising a communication path that connects the space.   The fuel supply pump according to any one of claims 1 to 4, wherein the integrated holder part and valve seat part are made of a carburized material or bearing steel. A fuel pressurization chamber provided in the plunger barrel; a fuel intake valve fixed to the plunger barrel for supplying fuel to the fuel pressurization chamber; and a plunger for pressurizing fuel in the fuel pressurization chamber; In a fuel supply pump comprising:
The fuel intake valve includes a valve body, a valve seat portion that has a fuel intake passage and a fuel reservoir chamber, and slides and holds the valve body, one end of which is fixed to the valve seat portion, and the other end of the valve seat portion. An urging means for urging the valve body fixed to the valve body; a holder part for fixing the fuel intake valve to the plunger barrel while having a space in which the urging means is housed and held; With
A fuel supply pump, wherein the valve seat portion and the holder portion are integrally formed.

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