JP2017515049A - Fuel pump and method for operating the fuel pump - Google Patents

Abstract

The present invention is a fuel pump comprising a piston (2), an actuator (3) for operating the piston (2), a return element (4) for returning the piston (2) to an initial position, a first In the fuel pump having the inflow valve (5), the outflow valve (6), and the pressure feeding chamber (7), the front chamber (8), between the front chamber (8) and the pressure feeding chamber (7). And a second inflow valve (9) for opening and closing the connecting portion of the fuel pump. Furthermore, the present invention relates to a fuel two-stage pumping method using the fuel pump (1) according to the present invention.

Description

BACKGROUND OF THE INVENTION The present invention relates to a fuel pump for supplying fuel in a motor vehicle such as a motorcycle, a motor boat, or another small motor such as a chain saw, and a method of operating the fuel pump. The present invention further relates to a fuel tank having the fuel pump as described above.

  Such a fuel pump is known, for example, from GB 2478766. In this case, it is a fuel pump, in particular a magnet piston pump, having a piston, an actuator for operating the piston, a return element for returning the piston to the initial position, an inflow valve, a pressure feeding chamber, and an outflow valve. By operating the piston in the suction stage, the fuel is sucked into the pumping chamber via the inflow valve. In the pumping stage, fuel is pumped from the pumping chamber through an outflow valve. Based on the thermal load, the fuel may release gas if the suction pressure at the inlet valve is low, which will fill most of the pumping chamber with fuel vapor. This can greatly impair the volumetric efficiency and function of the pump until a complete failure is reached.

DISCLOSURE OF THE INVENTION On the other hand, the fuel pump according to the present invention having the features described in claim 1 is capable of reducing the minimum negative pressure in the intake stage, thereby preventing the fuel from being released from the gas. It has the advantage that it can. This is achieved according to the invention by pre-feeding the fuel into the front chamber, pressurizing the fuel at this time and then flowing the fuel into the pressure-feed chamber via the second inlet valve. In this case, the fuel pump includes a piston, an actuator that operates the piston, a return element that returns the piston to the initial position, a first inflow valve, an outflow valve, and a pressure feeding chamber. Based on this invention, the front chamber and the 2nd inflow valve which opens and closes the connection part between this front chamber and a pumping chamber are provided. That is, in the present invention, improved fuel pumping can be achieved by using a second inflow valve located upstream of the first inflow valve.

  Preferred refinements of the invention are described in the dependent claims.

  Preferably, the piston isolates the pumping chamber from the front chamber. Thereby, two-stage pumping of fuel can be ensured by only a single fuel pump and a single piston. This leads to cost and space savings, which is particularly important in motorcycles or other small equipment that can be provided with less space.

  Preferably, the pumping chamber and the front chamber may be arranged in one common cylinder component. Thereby, a more compact and space-saving configuration can be realized.

  In yet another alternative configuration of the invention, the piston may preferably have a hollow chamber, and the front chamber may extend into the hollow chamber. On the one hand, the presence of a hollow chamber in the piston leads to material reduction, which in turn leads to cost reductions without compromising piston strength or function. On the other hand, a compact configuration is possible by using the hollow chamber of the piston as the front chamber. Preferably, the hollow chamber of the piston includes the entire front chamber.

  In order to connect between the front chamber and the pressure feeding chamber, a through opening may be preferably formed in the piston, and a second inflow valve may open and close the through opening. Furthermore, the fuel pump unit can be configured more compactly by arranging the through opening in the piston.

  More preferably, the through-opening in the piston may open to the pressure feeding chamber. As a result, the fuel can be directly pumped from the front chamber to the pumping chamber at a short distance. Thereby, for example, resistance loss based on a relatively long flow section can be avoided.

  More preferably, the first inflow valve, the second inflow valve, and the outflow valve may be arranged in a row. This means that the first inflow valve, the second inflow valve, and the outflow valve are arranged on a common line as a series component. This makes it possible to pump the fuel as much as possible on one flow line, which can lead to a reduction in losses, for example based on a flow section having a turning point.

  Alternatively, the second inflow valve and the outflow valve may be arranged in a common plane. As a result, the configuration of the fuel pump becomes more compact.

  Preferably, the maximum open cross section of the first inflow valve may be larger than the maximum open cross section of the second inflow valve. As a result, the suction loss and the minimum negative pressure can be reduced.

  More preferably, the anterior chamber may have a first dead volume and the pumping chamber may have a second dead volume. In this case, the first dead volume and the second dead volume are substantially the same size. When dead volumes exist in the pumping chamber and the anterior chamber, both dead volumes are preferably the same or approximately the same size. Thereby, a quicker and improved pumping can be performed between the pumping chamber and the front chamber.

  The invention further relates to a fuel tank comprising a fuel pump according to the invention, said fuel pump being arranged in the fuel tank. The invention further relates to other equipment powered by gasoline, such as motor vehicles, in particular motorcycles, or gardening or household equipment, for example with a fuel pump according to the invention.

  Furthermore, the present invention relates to a fuel two-stage pumping method using the fuel pump according to the present invention having the features of claim 12. In this case, the method according to the present invention includes a step of sucking fuel into the front chamber via a first inflow valve, a step of pressurizing fuel in the front chamber, and a second flow of pressurized fuel from the front chamber. The method includes a step of pumping to the pumping chamber through the valve, a step of pressurizing the fuel in the pumping chamber, and a step of pumping the pressurized fuel from the pumping chamber through the outflow valve. Thereby, also in the said method, the advantage acquired based on the fuel pump mentioned above is guaranteed.

  More preferably, the suction into the front chamber may be performed simultaneously with the pressurization of the fuel in the pressure feeding chamber. As a result, time-advantageous fuel two-stage pumping is possible.

  More preferably, the suction process can be performed on the rear side of the piston, and the fuel in the pumping chamber can be pumped on the front side of the piston. Thereby, fuel two-stage pumping can be ensured in a compact configuration using only a single fuel pump.

In the following, two embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this case, the same or functionally identical components are denoted by the same reference numerals.
1 is a schematic cross-sectional view of a fuel pump according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a principle of a suction stage and a pumping stage in which a part of the fuel pump according to the first embodiment is greatly simplified. FIG. 3 is a schematic cross-sectional view of the fuel pump portion shown in FIG. 2 greatly simplified showing the principle of the pre-feed stage. FIG. 4 is a schematic cross-sectional view that greatly simplifies a part of a fuel pump according to a second embodiment of the present invention.

In the following, a fuel pump 1 according to a first preferred embodiment of the invention will be described in detail with reference to FIG.

  As can be seen from FIG. 1, the fuel pump 1 according to the present invention is formed in the form of a magnet piston pump, and accordingly, a piston 2, an electromagnetic coil as an actuator 3 for operating the piston 2, and a piston 2. And a spring member as a return element 4 for returning the initial position to the initial position. The fuel pump 1 according to the present invention further includes a first inflow valve 5, an outflow valve 6, a pressure feeding chamber 7, a front chamber 8, and a second inflow valve 9.

  The cylindrical piston 2 in which the through-opening 21 is formed isolates the pressure feeding chamber 7 from the front chamber 8. In this case, the pressure feeding chamber 7 and the front chamber 8 are one common cylinder component 10. Is placed inside. Similarly, the piston 2 is disposed in the cylinder component 10. The piston 2 further has a cylindrical hollow chamber 20 into which the front chamber 8 extends. Further, the front chamber 8 is connected to the through opening 21.

  The front chamber 8 is further connected to the supply unit 11 via the first inflow valve 5. In this case, the supply unit 11 is also connected to, for example, a fuel tank or a fuel pipe (not shown). . The first inflow valve 5 disposed on the rear side 22 of the piston 2 is a plate valve. Of course, other forms of valves are also conceivable, such as diaphragm valves, check valves and the like.

  The second inflow valve 9 is also a plate valve, for example, and opens and closes the through opening 21 between the pressure feeding chamber 7 and the front chamber 8. In this case, the through opening 21 opens in the pressure feeding chamber 7. Furthermore, the second inflow valve 9 is arranged on the front side 23 of the piston 2. As shown in FIG. 1, the maximum open cross section 50 of the first inflow valve 5 is larger than the maximum open cross section 90 of the second inflow valve 9.

  The outflow valve 6 is arranged such that the pressure feeding chamber 7 is formed between the outflow valve 6 and the second inflow valve 9. Furthermore, the outflow valve 6 is formed as a plate valve.

  Further, the first inflow valve 5, the second inflow valve 9, and the outflow valve 6 are arranged in series on the common center line M.

  Next, the operation method of the fuel pump 1 will be described in detail with reference to FIGS.

  In order to explain the method according to the invention, first the general function of the fuel pump 1 will be explained in connection with the cooperation of the actuator 3 and the piston 2.

  When the actuator 3 or the electromagnetic coil of the fuel pump 1 is supplied with power, the piston 2 moves in the first direction (thick arrow R in FIG. 3) based on the generated magnetic field, and in this case, the return element 4 is compressed. Now, when the power supply to the actuator 3 is cut off, the piston 2 is pushed away in the second direction opposite to the first direction by the movement of the return element 4 (thick arrow L in FIG. 2).

  FIG. 2 specifically shows the suction and pumping steps of the method according to the invention, in which case the piston 2 is moved in the second direction by the return element 4 (illustrated by a thick arrow L). As a result, the first inflow valve 5 is opened, and the fuel is sucked into the front chamber 8 from the fuel tank (not shown), for example, via the first inflow valve 5 (arrow A). It should be pointed out that most of the sucked fuel flows into the hollow chamber 20 of the piston 2 (arrow B), and the front chamber 8 extends into the hollow chamber 20. At the same time as the fuel is sucked into the front chamber 8 via the first inflow valve 5, the fuel already existing in the pressure feeding chamber 7 is pressurized in the second direction by the movement of the piston 2. In this case, the second inflow valve 9 is closed. The outflow valve 6 opens from a predetermined pressure level in the pumping chamber 7, and pressurized fuel is pumped from the pumping chamber 7 to the internal combustion engine (not shown) via the outflow valve 6 (arrow C in FIG. 2). ).

  FIG. 3 shows the prefeed phase of the method according to the invention, in which the piston 2 is moved in the first direction by the actuator 3 (illustrated by a thick arrow R). By this movement of the piston 2, the first inflow valve 5 is closed and the fuel in the front chamber 8 is pressurized. The second inflow valve 9 opens from a predetermined pressure level in the front chamber 8. As a result, the fuel pressurized in the front chamber 8 is pre-feeded from the front chamber 8 into the pressure feeding chamber 7 via the second inflow valve 9 (arrow D).

  Then, a new stroke of the fuel pump 1 can be performed by repeating the suction stage and the pumping stage.

  Next, a fuel pump 1 according to a second preferred embodiment of the present invention will be described with reference to FIG. In this case, the fuel pump 1 in the suction stage is shown. In the suction stage, the first inflow valve 5 and the outflow valve 6 are open, and the second inflow valve 9 is closed.

  This second embodiment basically differs from the first embodiment in that the second inflow valve 9 and the outflow valve 6 are arranged in one common plane E. In this case, unlike the first embodiment, the piston 2 does not have a through-opening, and the front chamber 8 and the pressure feeding chamber 7 are connected via a conduit 12. The connection via the conduit 12 is opened and closed by the second inflow valve 9. Furthermore, the piston 2 is formed so that the fuel pump 1 functions in the manner described above. Furthermore, each valve of this embodiment is formed as a ball check valve.

  It should be pointed out that each of the above-described embodiments is useful for understanding the present invention and is not considered to be limiting in this respect. That is, for example, a disk instead of a piston can be considered similarly.

  That is, the fuel pump 1 according to the present invention and the operation method of the fuel pump 1 according to the present invention provide a compact configuration that solves the problem of fuel gas release during suction. In this case, two-stage pumping of fuel is performed. However, there is no need for a second fuel pump. This saves space and cost. Furthermore, suctioning behind the piston 2 results in a decrease in the minimum negative pressure. This is because inhalation takes place at a lower speed and results in a more compact construction of the fuel pump.

  Furthermore, the improved function of the internal combustion engine of the vehicle can be ensured by means of the fuel pump 1 according to the invention and the method according to the invention.

Claims (14)

The piston (2),
An actuator (3) for actuating the piston (2);
A return element (4) for returning said piston (2) to its initial position;
A first inlet valve (5);
An outflow valve (6);
A fuel pump comprising a pressure feeding chamber (7),
Anterior room (8),
A second inflow valve (9) for opening and closing a connection between the front chamber (8) and the pressure feeding chamber (7);
A fuel pump, further comprising:   The fuel pump according to claim 1, wherein the piston (2) isolates the pressure feeding chamber (7) from the front chamber (8).   The fuel pump according to claim 1 or 2, wherein the pressure feeding chamber (7) and the front chamber (8) are arranged in a common cylinder component (10).   The fuel pump according to any one of claims 1 to 3, wherein the piston (2) has a hollow chamber (20), and the front chamber (8) extends into the hollow chamber (20). .   The piston (2) is formed with a through-opening (21), and the second inflow valve (9) opens and closes the through-opening (21). The fuel pump described.   The fuel pump according to claim 5, wherein the through-opening (21) opens into the pressure feeding chamber (7).   The said 1st inflow valve (5), the said 2nd inflow valve (9), and the said outflow valve (6) are arrange | positioned on one line (M), Any of Claim 1-6 A fuel pump according to claim 1.   The fuel pump according to any one of claims 1 to 4, wherein the second inflow valve (9) and the outflow valve (6) are arranged in a common plane (E).   9. The fuel pump according to claim 1, wherein a maximum open cross section of the first inflow valve (5) is larger than a maximum open cross section of the second inflow valve (9).   The anterior chamber (8) has a first dead volume, the pumping chamber (7) has a second dead volume, and the first dead volume and the second dead volume are: The fuel pump according to any one of claims 1 to 9, wherein the fuel pump has substantially the same size.   A motor vehicle comprising a fuel pump (1) according to any one of the preceding claims. A fuel pump having a piston (2), a first inflow valve (5), an outflow valve (6), a pressure feeding chamber (7), a front chamber (8), and a second inflow valve (9) In the fuel two-stage pumping method using (1),
Sucking fuel into the front chamber (8) via the first inlet valve (5);
Pressurizing the fuel in the front chamber (8);
Pumping the pressurized fuel from the front chamber (8) to the pumping chamber (7) via the second inlet valve (9);
Pressurizing the fuel in the pressure feeding chamber (7);
Pumping the pressurized fuel from the pumping chamber (7) through the outflow valve (6);
A two-stage pumping method of fuel, characterized by comprising:   13. The method according to claim 12, wherein the suction into the front chamber (8) is performed simultaneously with the pressurization of the fuel in the pumping chamber (7).   The method according to claim 13, wherein the suction process is performed on the rear side (22) of the piston (2), and the pumping of fuel in the pumping chamber (7) is performed on the front side (23) of the piston (2). .

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