JP5666331B2 - Fuel supply device - Google Patents

Description

  The present invention relates to a fuel supply device that adjusts the pressure of fuel supplied from a fuel tank to a fuel injection valve of an internal combustion engine by a fuel pump.

  Conventionally, a fuel supply apparatus shown in FIG. 9 is known. As shown in FIG. 1 and as will be described later, the fuel supply device has a fuel pump and a pressure regulating valve unit 2 attached to a mounting member 1 attached to the upper wall of the fuel tank. When the discharge pressure exceeds a certain level, the valve body 8 of the pressure regulating valve unit 2 is opened, and the discharge pressure is adjusted by returning excess fuel to the fuel tank.

  Referring to FIG. 9, the attachment member 1 has a fuel return passage 3 branched from a fuel supply passage for sending fuel from the fuel pump to the fuel injection valve of the internal combustion engine, and a lower end of the fuel return passage 3 is below the fuel return passage 3. Has a substantially cylindrical fitting hole 4 that opens into the fuel tank, and surplus fuel from the fuel pump is inserted into the fitting hole 4 via the fuel return passage 3 as indicated by a white arrow. It is sent to the pressure regulating valve unit 2 to be press-fitted.

  The pressure regulating valve unit 2 includes a valve housing 6 having a large-diameter internal space 5, a small-diameter fuel introduction hole 7 formed above the valve housing 6, and a spherical valve body 8 that opens and closes the fuel introduction hole 7. And a spring 10 that presses the valve body 8 toward the valve seat 9 of the fuel introduction hole 7 and an annular seal member 11 provided on the outer periphery of the valve housing 6.

  The pressure regulating valve unit 2 is press-fitted into the fitting hole 4 from below, and the upper end inner surface of the fitting hole 4 and the upper outer surface of the valve housing 6 are in contact with each other, that is, there is no gap S in FIG. It fixes in such a form (refer patent document 1).

  By the way, when such a pressure regulating valve unit 2 is press-fitted into the fitting hole 4, it is not easy to press-fit the shaft of the pressure regulating valve unit 2 along the axis of the fitting hole 4. Even if press-fitting is performed so that there is no gap S, the fixing is not as firm as the screw or the like, and it is caused by vibration of the fuel tank or the pressure of the fuel acting in the direction of the pressure regulating valve unit 2 from the fuel return passage 3 side. There is a high probability that the entire pressure regulating valve unit 2 moves downward and a gap S is newly generated.

  When a gap S is formed between the upper end inner surface of the fitting hole 4 and the upper end outer surface of the valve housing 6, an orthogonal space 12 orthogonal to the fuel return passage 3 is generated, and the orthogonal space 12 further includes an annular seal member 11. A larger space is formed by combining with the surplus space 13 excluding the seal member 11 at the place where the is provided.

  The present inventor conducted experiments on the gap S of 0.5 mm and 1 mm as to what kind of problem would occur if there was such a space. In the experiment, the fuel supply device is placed in the liquid and the presence or absence of abnormal noise is measured with a submerged microphone, or the presence or absence of abnormal vibration is measured by placing a vibration sensor on the mounting member 1. A pressure sensor was inserted to measure the presence or absence of pressure pulsation.

  As a result, abnormal noise and pulsation occurred at both 0.5 mm and 1 mm as compared with the gap S of 0 mm. The cause of abnormal noise and pulsation seems to be that resonance occurs in the space, and the pressure pulsation increases due to this resonance, so that the valve body 8 resonates. As described above, the conventional one has a possibility that abnormal noise is generated or the wear of the seal surface is caused by the pulsation of the valve body 8.

JP 2008-138785 A

  The object of the present invention is to provide a cylindrical body at the end of the fuel return passage or the end of the fuel introduction hole by solving such a problem. In order to eliminate the occurrence of noise and pulsation even if there is a gap between the upper end inner surface of the fitting hole and the upper end outer surface of the valve housing, or even if a new gap is generated. .

  In order to achieve the above object, the present invention adopts the following configuration.

In the first aspect of the invention, a fuel pump that is housed in a fuel tank and sends the fuel in the fuel tank to the internal combustion engine via a fuel supply passage, and a fuel discharged from the fuel pump that branches off from the fuel supply passage A fuel supply device comprising: a fuel return passage for returning a part of the fuel to the fuel tank; and a pressure adjustment valve unit provided in the fuel return passage for adjusting a discharge pressure from the fuel pump, wherein the pressure adjustment The valve unit includes a valve housing having an internal space, a fuel introduction hole that is provided in the valve housing and communicates with the internal space, a valve body that is accommodated in the internal space and opens and closes the fuel introduction hole, and the valve A spring for pressing the body, a downstream end of the fuel return passage has a fitting hole for fitting the pressure regulating valve unit, and a cylindrical body is formed at the end of the fuel return passage. one Provided, said tubular body, said enters the fuel introduction hole, said fuel introduction and the fuel return passage in the form of a gap between the fitting hole and said valve housing about said tubular body Configuration that communicates with the hole.

  In the invention according to claim 2, in addition to the structure of the invention according to claim 1, the cylindrical body is a cylindrical body.

In the invention according to claim 3 , in addition to the structure of the invention according to claim 1 or 2 , the fixing of the pressure regulating valve unit to the fitting hole is a snap-fit engagement.

In the invention according to claim 1, a cylindrical body is integrally provided at the end of the fuel return passage or the end of the fuel introduction hole, and the tubular body is inserted into the fuel introduction hole or the fuel return passage. By communicating the return passage with the fuel introduction hole, even if there is a gap between the upper end inner surface of the fitting hole and the upper end outer surface of the valve housing, or even if a new gap occurs, abnormal noise is generated. In addition, wear of the valve body seal surface due to pulsation can be prevented.
Further, by having a fitting hole for fitting the pressure regulating valve unit at the downstream end of the fuel return passage, the assembly of the pressure regulating valve unit can be facilitated.

  In the invention according to claim 2, by forming the cylindrical body into a cylindrical body, in addition to the effect of the invention according to claim 1, the formation and assembly of the cylindrical body are facilitated, and further the flow of fuel is smoothed. be able to.

In the invention according to claim 3 , in addition to the effect of the invention according to claim 1 or 2 , in addition to the effect of the invention according to claim 1 or 2 , by fixing the pressure adjusting valve unit to the fitting hole by snap fit engagement, Assembly with the valve unit can be made easier and more reliable than press-fitting.

Schematic showing the entire fuel supply apparatus of the present invention The expanded sectional view which shows the state which assembled the fitting hole and pressure adjustment valve unit of this invention Sectional drawing which shows the state before assembling the fitting hole and pressure control valve unit of FIG. A view of FIG. 3A in the A direction The expanded sectional view which shows the other example of the state which assembled the fitting hole and pressure regulation valve unit of this invention The figure which looked at the state which does not have the pressure regulation valve unit of FIG. The expanded sectional view which shows the other example of the state which assembled the fitting hole and pressure regulation valve unit of this invention Sectional drawing which shows the state before assembling the fitting hole and pressure control valve unit of FIG. Schematic sectional view of a conventional fuel supply device

  FIG. 1 shows a schematic overall view of a fuel supply system having a fuel supply device. The fuel supply device 30 is, for example, a device that sends fuel in a fuel tank 31 to a fuel injection valve 33 of an engine that is an internal combustion engine by a fuel pump 32, and adjusts the pressure of fuel supplied to the fuel injection valve 33 to a predetermined value. It has a pressure regulating valve. The in-tank type will be described below.

  A fuel pump 32 having a motor and a pump (not shown), a fuel filter 34 and a suction filter 35 are provided in the fuel tank 31 so as to hang from the mounting member 37. The fuel pump 32 and the fuel filter 34 are accommodated in a substantially container-shaped pump casing 36 made of, for example, one member or a plurality of members, and the pump casing 36 is screwed to a mounting member 37 fixed to the upper wall of the fuel tank 31. It attaches by means, such as.

  The attachment member 37 is provided with a fuel supply passage 38 that communicates the inside and outside of the pump casing 36. When the fuel pump 32 is driven, the fuel pump 32 is connected to the fuel tank 31 as indicated by a black arrow. Fuel is sucked from the suction filter 35 disposed at the bottom, and the pressure is increased. The boosted fuel is filtered by the fuel filter 34 and sent to the fuel injection valve 33 from the fuel supply passage 38 as indicated by a black arrow. The fuel supply passage 38 is connected to a pipe 38a separate from that attached to the fuel tank 31, that is, one end of the fuel supply passage 38 is connected to the fuel supply passage 38 attached to the fuel tank 31, and the other end is a downstream member. For example, a pipe 38 a connected to the fuel injection valve 33 may be included.

  The attachment member 37 is provided with a fuel return passage 39 branched from the fuel supply passage 38, and a fitting hole 40 having a large diameter and opened downward is provided at the other end downstream of the fuel return passage 39. It is done. The fuel return passage 39 does not necessarily have to be provided in the mounting member 37. For example, only a part of the fuel return passage 39 may be provided, or may be provided so as not to pass through the mounting member 37 at all. But you can. Further, the fitting hole 40 is not necessarily provided in the mounting member 37. For example, the upper width of the pump casing 36 may be increased and provided in that portion, or the mounting member 37 and the pump casing 36 may be provided. A separate member may be provided on the fuel tank 31 and provided on the member.

  Two projecting members 41, 41 are provided at the lower end of the fitting hole 40. The projecting member 41 is a vertically long rectangular member having an arcuate cross section as viewed from the front, and as shown in FIG. The locking groove 42 is provided. Note that the number of protruding members 41 is not limited to two, and may be three, four, or the like, and the same number of protruding pieces 41 as the locking pieces 53 described later are used.

  The fitting hole 40 is engaged with a pressure regulating valve unit 45 that is also a pressure regulating valve. The pressure adjustment valve unit 45 includes a valve housing 46, a valve body 47, a spring 48, a spring support member 49, and a seal member 50.

  The valve housing 46 has a cylindrical upper small-diameter portion 46a and a cylindrical lower large-diameter portion 46b that are integrally formed. The upper small-diameter portion 46a is a thick portion of the upper portion of the valve housing 46, and a fuel introduction hole 51 that opens in the vertical direction is provided at the center thereof. The valve seat 46c is tapered. An annular seal member 50 is disposed on the outer periphery of the valve housing 46.

  The lower large-diameter portion 46b is a thin portion of about 3/4 of the lower portion of the valve housing 46. A cylindrical internal space 52 is formed at the center thereof, and the above two outer peripheral surfaces are formed on the outer peripheral surface thereof. Two locking pieces 53 that engage with the locking groove 42 are disposed to face each other with a separation of 180 degrees.

  And the valve body 47 is provided in the internal space 52 of the lower large diameter part 46b. The valve body 47 is composed of a spherical valve, a poppet valve, a conical valve, or the like. The valve body 47 is provided such that the lower part thereof is always pressed upward by the upper end of the spring 48 and the upper part thereof is in contact with the valve seat 46c.

  A spring support member 49 having a substantially dish shape and having an opening 49 a at the center thereof is press-fitted into the bottom of the opening at the lower end of the valve housing 46, and the lower end of the spring 48 is supported on the spring support member 49.

  The spring 48 has a function of adjusting the pressure of the fuel discharged from the fuel pump 32, and has a spring force suitable for the set pressure, and always presses the valve body 47 against the valve seat 46c to thereby provide the valve body. It has a function of being pushed down when the force of pushing down 47 becomes a predetermined value or more.

  By the way, as shown in FIG. 2 and FIG. 3A, a thin tubular body 60 having a circular cross section and being thin from the downstream end of the fuel return passage 39 is integrally formed at the lower end of the fuel return passage 39. The inside is also a continuous fuel return passage 39.

  The cylindrical body 60 is a cylindrical body and a member having the same diameter, and its outer diameter is slightly smaller than the inner diameter of the fuel introduction hole 51 and enters the fuel introduction hole 51 during assembly. The cylindrical body 60 may have an elliptical or polygonal cross section, or may not have the same diameter. For example, the fuel flow may be inclined so as to spread from the upper side to the lower side so that its thickness gradually becomes zero so that the fuel flow becomes smooth.

  Assembly is performed as follows. First, regarding the pressure regulating valve unit 45, the valve housing 46 is reversed, the valve body 47 is placed on the valve seat 46c, the spring 48 is placed on the valve body 47, and the spring support member is placed on the spring 48. 49 is press-fitted and fixed. As a result, the pressure regulating valve unit 45 as shown in FIG. 3B is completed.

  Next, the seal member 50 is fitted on the outer periphery of the upper small diameter portion 46a of the valve housing 46, and the pressure regulating valve unit 45 is fitted into the fitting hole 40 as shown by the arrow in FIG. The outer diameter of the pressure regulating valve unit 45 is slightly smaller than the inner diameter of the fitting hole 40, and the insertion is easy.

  When the pressure regulating valve unit 45 is pushed into the fitting hole 40, the seal member 50 becomes a resistance. When pushed in anyway, the outer periphery of the locking piece 53 of the valve housing 46 contacts the inner periphery of the protruding member 41. When pushed in anyway, the tip of the cylindrical body 60 enters the fuel introduction hole 51. When pushed in anyway, the locking piece 53 fits into the locking groove 42 of the protruding member 41, and the cylindrical body 60 enters the fuel introduction hole 51. As a result, the pressure regulating valve unit 45 is engaged and fixed in the fitting hole 40 as shown in FIG. Such engagement between the locking piece 53 and the locking groove 42 is called so-called snap-fit engagement. By using such snap-fit engagement, the pressure regulating valve unit 45 can be easily fixed. It can be carried out. Instead of such snap-fit engagement, snap-fit engagement in which the locking piece 53 is provided inside the protruding member 41 and the locking groove 42 is provided in the valve housing 46 may be used.

  As described above, since the fuel return passage 39 and the fuel introduction hole 51 of the pressure regulating valve unit 45 are in direct communication with each other through the cylindrical body 60, the fuel return passage is indicated by the white arrow in FIG. The fuel flowing in the passage 39 is prevented from flowing into the gap S of the fitting hole 40, and the pressure is adjusted in a normal state where there is no pressure pulsation or the like due to the gap S.

  5 and 6 show a modification in which the pressure regulating valve unit 45 is attached. The common numbers are as described above, and the description thereof is omitted. In the figure, a locking member 61 facing inward and facing each other is provided at the lower end of the projecting member 41, and the lower end of the pressure regulating valve unit 45 is locked by this locking member 61. Such a locking member 61 can also achieve the same effect as that of FIG. In addition, the thing of FIG. 2 needs to be assembled by matching the positions of the locking piece 53 and the locking groove 42, but in this example, the pressure regulating valve unit 45 can be engaged at any position, As much as it is assembled.

  The engagement as shown in FIGS. 2 and 5 is, for example, insertion while pressing the seal member 50, but is easier to assemble than the press-fitting of the conventional example, and the outer diameter of the pressure regulating valve unit 45 is Although it is not necessary to increase the accuracy, the production cost can be reduced as much. On the other hand, a gap S is easily generated between the upper end inner surface of the fitting hole 40 and the upper end outer surface of the valve housing 46. Pulsation will occur.

  However, according to the present invention, even if the gap S is generated, the fuel return passage 39 and the fuel introduction hole 51 are directly communicated with each other by the cylindrical body 60 without resistance. Can be eliminated.

  7 and 8 show a modification of the cylindrical body. The common numbers are as described above, and the description thereof is omitted. In the figure, a cylindrical body 70 is provided at the upper end of the valve housing 46.

  That is, at the upper end portion of the upper small-diameter portion 46 a of the valve housing 46, as shown in FIGS. 7 and 8B, a thin cylindrical body 70 having a circular cross section is erected from the upper end of the fuel introduction hole 51. The fuel introduction hole 51 is also formed in a continuous manner.

  The cylindrical body 70 is a cylindrical body and a member having the same diameter, and its outer diameter is slightly smaller than the inner diameter of the fuel return passage 39, and enters the fuel return passage 39 during assembly. The cylindrical body 70 may have an elliptical or polygonal cross section, or may not have the same diameter. For example, in order to make the fuel flow smooth, it may be inclined so as to become narrower from the upper side to the lower side in an inverted C shape so that the thickness gradually increases from zero.

  In this way, by connecting the fuel introduction hole 51 and the fuel return passage 39 with the cylindrical bodies 60 and 70 integrally formed in either one, the above-described adverse effect caused by the gap S can be eliminated, and the cylindrical body. Therefore, in other words, there is nothing that disturbs the flow of fuel in the cylindrical body, so no new pulsation occurs.

  The present invention is not limited to the configuration of the above-described embodiment, and can be appropriately changed in design without departing from the gist of the invention. For example, the insertion into the fitting hole 40 may be press-fitting. In the case of press fitting, the protruding member 41, the locking groove 42 and the locking piece 53 are not necessary.

DESCRIPTION OF SYMBOLS 30 ... Fuel supply device 31 ... Fuel tank 32 ... Fuel pump 33 ... Fuel injection valve 34 ... Fuel filter 35 ... Suction filter 36 ... Pump casing 37 ... Mounting member 38 ... Fuel supply passage 38a ... Pipe 39 ... Fuel return passage 40 ... Fitting Joint hole 41 ... Projection member 42 ... Locking groove 45 ... Pressure adjusting valve unit 46 ... Valve housing 46a ... Upper small diameter part 46b ... Lower large diameter part 46c ... Valve seat 47 ... Valve body 48 ... Spring 49 ... Spring support member 49a ... Opening 50 ... Seal member 51 ... Fuel introduction hole 52 ... Internal space 53 ... Locking piece 60 ... Cylindrical body 61 ... Locking member 70 ... Cylindrical body

Claims (3)

A fuel pump housed in a fuel tank and sending fuel in the fuel tank to an internal combustion engine via a fuel supply passage;
A fuel return passage branched from the fuel supply passage and returning a part of the fuel discharged from the fuel pump to the fuel tank;
A fuel supply device having a pressure adjustment valve unit that is provided in the fuel return passage and adjusts a discharge pressure from the fuel pump;
The pressure regulating valve unit includes a valve housing having an internal space, a fuel introduction hole provided in the valve housing and communicating with the internal space, and a valve body that is accommodated in the internal space and opens and closes the fuel introduction hole. And a spring for pressing the valve body,
The downstream end of the fuel return passage has a fitting hole for fitting the pressure regulating valve unit,
A cylindrical body is integrally provided at the end of the fuel return passage,
Said tubular body, enters into the fuel introduction hole, communicating the said fuel return passage in the form of a gap fuel introduction hole between the fitting hole and said valve housing about said tubular body A fuel supply device.   The fuel supply apparatus according to claim 1, wherein the cylindrical body is a cylindrical body. The fuel supply device according to claim 1 , wherein the pressure regulating valve unit is fixed to the fitting hole by snap-fit engagement.

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