JP4637264B2 - Suction jet pump - Google Patents

Description

  The present invention is a suction jet pump comprising a fuel injection nozzle, a mixing pipe, a suction opening, a fuel conduit connected to the fuel injection nozzle, and a valve disposed in the fuel conduit. The valve casing has an inflow portion and an outflow portion. Suction jet pumps are used in automobile fuel tanks.

  Such suction jet pumps are used in fuel tanks, whereby fuel is supplied from different areas of the fuel tank to one pumping unit, which pumps fuel from the fuel tank to the internal combustion engine of the vehicle. To do. In order to drive the suction jet pump, part of the fuel pumped from the fuel pump is branched and supplied to the suction jet pump via the fuel conduit. When starting the internal combustion engine, it is desirable for the fuel pump to pump a sufficient amount of fuel to the internal combustion engine as quickly as possible. For this purpose, a valve is arranged in the fuel conduit that opens only after the system pressure is reached, so that all the fuel pumped, especially during the starting process, is first supplied to the internal combustion engine.

  In order to improve the starting characteristics of a motor vehicle, it is known to temporarily increase the pressure in the supply conduit. For this purpose, the output of the fuel pump is temporarily increased during the starting process. This, however, negates the action of the valve in the fuel conduit which should release the fuel conduit only after the system pressure is obtained. This has the disadvantage that the valve for separating the suction jet pump for the starting process from the fuel supply part opens due to an increase in pressure. Thereby, part of the fuel reaches the suction jet pump and is not supplied to the internal combustion engine. Nevertheless, in order to ensure that sufficient fuel is supplied to the internal combustion engine during the starting process, the fuel pump has been increased on the basis of the open valve in addition to the increased demand in the internal combustion engine. The fuel pump needs to be sized so that it also supplies the pumping volume for the suction jet pump. These increased pumping volumes result in fuel pump oversize. Such fuel pumps require significantly more construction space and are even more expensive.

  Accordingly, it is an object of the present invention to provide a suction jet pump that operates exclusively when the fuel supply system operates at system pressure.

  In order to solve this problem, in the present invention, a flow opening is disposed in the casing, and the valve body is provided on both sides of the flow opening so that the flow opening can be closed on both the inflow side and the outflow side. And at least one spring is arranged in the casing so that the spring holds the valve body in a position to close the outlet side of the flow opening until a system pressure is reached. I did it.

  The valve located in the fuel conduit of the suction jet pump is closed in the non-pressure state by the spring holding the valve body in a position closing the flow opening on the outflow side. As soon as the fuel pump reaches the system pressure, the force acting on the valve body becomes greater than the spring force, so that the valve body is moved from the position closing the flow opening on the outflow side. That is, the valve is open and the fuel can reach the suction jet pump. When the pressure increases beyond the system pressure during the starting process, the valve body is further moved against the spring force until the valve body reaches a position where it closes the flow opening on the inflow side, thereby closing the valve. . The valve according to the invention makes it possible to operate the suction jet pump within a pre-adjustable pressure range, in which case the suction jet pump is shut off below the pressure range and above the pressure range. This allows the suction jet pump to operate exclusively under standard conditions, but in critical situations where the fuel supply of the internal combustion engine should first be guaranteed, the fuel pumped from the fuel pump is exclusively Reach only the internal combustion engine. This allows the fuel pump to be sized relatively small. This is because the pumping output of the fuel pump is defined by the internal combustion engine and the suction jet pump only at the system pressure, while the pumping output is the suction jet pump while the fuel pump operates at a pressure higher than the system pressure. This is because it is defined only by the internal combustion engine based on the shut-off.

  The flow opening is particularly simple if it is configured as a baffle.

  According to another advantageous configuration, the valve body has two sealing members which cooperate with the sealing seat on the inflow side and the outflow side in the flow opening, A reliable seal is obtained.

  The seal member of the valve body has a simple and inexpensive structure and is composed of one annular disk disposed on the valve body.

  If the sealing member is arranged on both sides of the baffle plate with respect to the flow direction so as to surround the flow opening, the structure of the valve body is simplified.

  In a further advantageous configuration, the defined position of the valve body in the open state at the system pressure is a second spring arranged with respect to the first spring, in which case the first spring is a valve And the second spring is obtained by allowing further movement of the valve body for the first time at a pressure higher than the system pressure. In this way, movement of the valve body in the open state at system pressure is prevented.

  The springs used may be compression springs or tension springs, and these springs are arranged between the casing and the valve body.

  As long as a compression spring is used, this compression spring can also be arranged between the valve body and the flow opening in yet another advantageous configuration. In order to better guide and attach the compression spring, in a further advantageous configuration, a step is integrally formed in the valve body.

  In the following, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 schematically shows a fuel tank 1 of an automobile in which a pumping unit 2 for pumping fuel to an internal combustion engine 3 is arranged. The pumping unit 2 has a fuel pump 5 driven by an electric motor 4 and is connected to the internal combustion engine 3 via a supply conduit 6. From the supply conduit 6, a fuel conduit 7 leads to a suction jet pump 8, which pumps the fuel to the pumping unit 2. The suction jet pump 8 flows out of the fuel conduit 7, a valve 9 disposed in the fuel conduit 7, a fuel injection nozzle 10 connected to the fuel conduit 7, a mixing tube 11, and the fuel injection nozzle 10. And a suction opening 12 for sucking fuel to be mixed into the mixing tube 11.

  FIG. 2 schematically shows a first embodiment of the valve 9 shown in FIG. The flow direction is illustrated by arrows. The valve 9 has a valve casing 13 having an inflow portion 14 and an outflow portion 15. In the valve casing 13, a baffle plate 16 having a flow opening 17 is disposed. The valve 9 has a valve body 18 having two disk-shaped areas 19 and 20, and the disk-shaped areas 19 and 20 are coupled to each other via an intermediate member that penetrates the flow opening 17. Therefore, the disk-shaped regions 19 and 20 are arranged on the inflow side and the outflow side of the flow opening 17, respectively. Both regions 19 and 20 have disc-shaped seal members 21 and 22, respectively, and these seal members 21 and 22 cooperate with the seal seats 23 and 24 of the baffle plate 16, respectively. A compression spring 25 is disposed on the outflow side, and this compression spring 25 moves the valve body 18 in the direction opposite to the flow direction. FIG. 2 shows a non-pressure state in which the fuel does not flow through the valve 9. Based on the spring force, the valve body 18 is in contact with the baffle plate 16 on the outflow side. In this case, the seal member 21 cooperates with the seal seat 23 to close the flow opening 17.

  FIG. 3 shows the valve 9 in the system pressure state. The fuel flowing in through the inlet 14 due to the system pressure generates a force acting in the longitudinal direction, and this force resists the spring force. In this case, the compression spring 25 is set so that the valve element 18 is moved in the flow direction at the system pressure so that both the seal members 21 and 22 do not contact the seal seats 23 and 24, respectively. Thereby, the flow opening 17 is in an open state, and the fuel can flow through the valve 9 toward the outflow portion 15 and further toward the suction jet pump.

  FIG. 4 shows the valve 9 during the starting process of the internal combustion engine. In this case, the fuel pump is controlled so that the pressure in the supply conduit temporarily increases. Thus, this increased pressure also acts at the fuel conduit and valve inlet 14. Since the spring force generated by the compression spring 25 is smaller than the force acting on the valve body 18 based on the increased pressure, the seal member 22 in the region 20 is inflow of the baffle plate 16 into the valve body 18. It is further moved in the flow direction until it abuts the side seal seat 24. As a result, the flow opening 17 is closed, so that fuel does not reach the suction jet pump during the starting process.

  The valve 9 shown in FIG. 5 differs from the valve shown in FIG. 2 in the arrangement of the compression spring 25. The compression spring 25 is supported between the baffle plate 16 and the region 20 of the valve body 18. For this purpose, this region 20 has a step 26. This step 26 acts on the one hand as a guide for the compression spring 25 and, on the other hand, ensures a sufficient construction space in the axial extension when the compression spring 25 is compressed.

  The valve 9 shown in FIG. 6 is provided with a tension spring 27, which is fixed between the casing 13 and the valve body 18 on the inflow side, and this valve body 18 flows in the non-pressure state in the flow direction. The valve 9 is closed because the seal member 21 cooperates with the seal seat 23 of the baffle plate 16.

  FIG. 7 shows yet another configuration of the valve 9 at system pressure. In this case, two compression springs 25 and 28 are arranged on the outflow side. The compression spring 25 operates corresponding to the configuration shown in FIGS. The compression spring 28 is configured to be stronger and have a shorter configuration length. In this case, the length and spring stiffness of the compression spring 28 are determined by the force that the valve body 18 acts on the valve body 18 at the system pressure. The compression spring 28 is selected to move in the flow direction until it abuts against the compression spring 28 without being compressed. In this position, the valve 9 is in the open position. In this way, a defined position in the system pressure is obtained for the valve body 18. If the pressure is further increased in the starting process, the force acting on the valve body 18 is larger than the spring force of the compression springs 25 and 28, so that the valve operates as shown in FIG.

It is the schematic of the fuel tank provided with the pumping unit and the suction jet pump by this invention. It is the figure which showed the position of the valve of the suction jet pump shown in FIG. It is the figure which showed the position of the valve of a suction jet pump different from the position of the valve shown in FIG. It is the figure which showed the position of the valve of a suction jet pump different from the position of the valve shown in FIG.2 and FIG.3. It is the figure which showed another Example of the valve shown in FIG. It is the figure which showed another Example of the valve shown in FIG. It is the figure which showed another Example of the valve shown in FIG.

Claims (11)

A suction jet pump comprising a fuel injection nozzle, a mixing pipe, a suction opening, a fuel conduit connected to the fuel injection nozzle, and a valve disposed in the fuel conduit; In the type in which the casing has an inflow portion and an outflow portion,
A flow opening (17) is arranged in the casing (13), and the flow opening (17) can be closed on both sides of the flow opening (17) so that it can be closed on both the inflow side and the outflow side. A valve body (18) is arranged, and at least one spring (25, 27, 28) passes through the valve body (18) in the casing (13) until the system pressure is reached. Suction jet pump, characterized in that it is arranged to hold the outflow side of the flow opening (17) in a closed position.   Suction jet pump according to claim 1, wherein the flow opening is formed as a baffle (16).   The valve body (18) has two seal members (21, 22), and these seal members each have one seal seat (23, 23) on the inflow side and the outflow side, respectively. 24. The suction jet pump according to claim 1 or 2, which cooperates with 24).   The suction jet pump according to claim 3, wherein the sealing member (21, 22) is an annular disk.   Suction according to claim 1 or 2, wherein the sealing member (21, 22) is arranged on both sides of the baffle plate (16) in the flow direction so as to surround the flow opening (17). Jet pump.   A second spring (28) is arranged with respect to the first spring (25), the first spring (25) is set to the opening pressure of the valve (9), and the second spring Suction jet pump according to any one of claims 1 to 5, wherein (28) only allows further movement of the valve body (18) at a pressure higher than the system pressure.   Suction jet pump according to any one of the preceding claims, wherein at least one spring (25, 28) is a compression spring.   Suction jet pump according to any one of the preceding claims, wherein the at least one spring (27) is a tension spring.   Suction jet pump according to claim 7 or 8, wherein the spring (25, 27, 28) is arranged between the casing (13) and the valve body (18).   Suction jet pump according to claim 7, wherein the spring (25, 28) is arranged between the valve body (18) and the flow opening (17).   The suction jet pump according to claim 10, wherein a step (26) is formed integrally with the valve body (18) in order to attach the spring (25, 28).

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