Patent Application
20090090330
1. Field of the Invention
The present invention relates to a fuel pump to be used for supplying fuel to an engine and more particularly to a fuel pump control device for controlling the fuel pump.
2. Description of Related Art
Heretofore, one technique of this type is disclosed in JP2001-214826A. Specifically, JP'826A discloses an in-tank fuel pump including a pump body placed in a fuel tank.
As to the in-tank fuel pump disclosed in JP2001-214826A, it is conceivable to provide a control device (a controller or the like) for pump in the fuel tank. In this case, however, fuel vapor generated in the fuel tank is likely to cause damage leading to malfunction to an electric component of the control device.
The present invention has been made in view of the above circumstances and has an object to provide a fuel pump control device capable of protecting an electric component from damage caused by fuel vapor even when placed in a fuel tank.
Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the purpose of the invention, there is provided a fuel pump control device including an electric component for controlling a fuel pump, at least part of the control device being to be placed in a fuel tank, the control device comprising: a housing in which the electric component is housed; and an adsorbent provided in the housing to adsorb fuel vapor.
The accompanying drawings, which are incorporated in and constitute a part of this specification illustrate an embodiment of the invention and, together with the description, serve to explain the objects, advantages and principles of the invention.
In the drawings,
A detailed description of a preferred first embodiment of a fuel pump control device embodying the present invention will now be given referring to the accompanying drawings.
As shown in
The control device 1 placed in the fuel tank 3 includes an electric component 11 for controlling the fuel pump 6 as shown in
As shown in
The electric component 11 includes a control circuit unit 17 and an external terminal 18 extending from the control circuit unit 17. The control circuit unit 17 is constituted of a plurality of circuit elements 20 arranged on a substrate 19. The control circuit unit 17 is provided with a circuit configuration for controlling the fuel pump 6. In this embodiment, the outer surface of the control circuit unit 17 is entirely coated with a coating material (not shown). This coating material used in this embodiment is “rubber or fluorocarbon adhesive”. With this coating material, the circuit element 20 and others can be protected. The external terminal 18 extends from the substrate 19, passing through the covering member 15, to the outside. The adsorbent 13 is charged in the space between the covering member 15 and the control circuit unit 17. The adsorbent 13 used in this embodiment is “activated charcoal such as palm shells, coal, and wood coal”. The adsorbent 13 is provided as a cartridge, specifically, in the form of a cartridge previously compressed into a columnar shape. The housing body 14 is formed on an upper part with a shoulder portion 14b made by partly decreasing outer and inner diameters. The adsorbent 13 is held on this shoulder portion 14b. The external terminal 18 is placed passing through a hole 13a formed in the adsorbent 13 so that a distal end of the external terminal 18 protrudes into the connector hole 15a of the covering member 15.
In this embodiment, the external terminal 18 is insert-molded in the covering member 15. Concretely, when the covering member 15 is to be made by resin molding, the external terminal 18 is set as an insert in a molding die and resin molded integral with the covering member 15. Prior to the insert molding, the outer surface of the external terminal 18 is coated with a primer (not shown). The primer exhibits a seal function when it is interposed between the covering member 15 and the external terminal 18 after the insert molding. In other words, it is possible to prevent fuel vapor from entering the housing 12 through a gap between the external terminal 18 and the covering member 15. The primer used in this embodiment is a “nitryl rubber adhesive”. Since the external terminal 18 is insert-molded in the covering member 15 as above, the adsorbent 13, the control circuit unit 17, the external terminal 18 and the covering member 15 are assembled together before they are inserted in the housing body 14. To be concrete, the external terminal 18 insert-molded in the covering member 15 is inserted in the adsorbent 13 and then a proximal end of the external terminal 18 is fixedly connected to the substrate 19 of the control circuit unit 17. Such assembly of the components 13, 15, 17, and 18 is inserted in the housing body 14 in order of the control circuit unit 17 and the adsorbent 13, and finally the covering member 15 is fitted in the opening 14a of the housing body 14. The control device 1 shown in
The control device 1 of this embodiment described above is placed in the fuel tank 3 and hence will be exposed to the atmosphere of fuel vapor. In case the fuel vapor enters the housing 12 through a gap between sealing areas of the covering member 15 and the opening 14a of the housing body 14, the fuel vapor will be adsorbed and trapped by the adsorbent 13. Thus, the fuel vapor is unlikely to touch the electric component 11. The electric component 11 can therefore be protected from damage caused by the fuel vapor.
In this embodiment, a part of the external terminal 18 surrounded by the adsorbent 13 is protected by the adsorbent 13. This makes it possible to enhance the durability of the external terminal 18. The adsorbent 13 formed as a cartridge in this embodiment is easy to handle singly and can readily be inserted and charged in the housing 12. In this regard, the adsorbent 13 contributes to simplification of manufacture of the control device 1.
Next, a second embodiment of a fuel pump control device according to the present invention will be described in detail referring to the accompanying drawing.
In each subsequent embodiment mentioned below, the same or similar components as those in the first embodiment are given the same reference signs and their details are omitted. The following explanation is focused on differences from the first embodiment.
This embodiment can also provide the same operations and advantages as in the first embodiment. In this embodiment, particularly, the control circuit unit 17 is surrounded and hence protected by the granular adsorbent 22. The durability of the control circuit unit 17 can therefore be enhanced.
A third embodiment of a fuel pump control device according to the present invention will be described in detail referring to the accompanying drawing.
Consequently, this embodiment can also provide the same operations and advantages as in the second embodiment. In this embodiment, particularly, the filling amount of adsorbent 22 can be economically reduced to half as compared with that in the second embodiment.
A fourth embodiment of a fuel pump control device according to the present invention will be described in detail referring to the accompanying drawing.
Accordingly, in addition to the same operations and advantages as in the first embodiment, the fourth embodiment in which the inside of the housing 12 communicates with atmosphere through the vent slot 15b can prevent the internal pressure in the housing 12 from becoming higher than the atmospheric pressure. It is therefore possible to prevent the internal pressure in the housing 12 from abnormally rising than saturated vapor pressure of the fuel vapor, thereby facilitating adsorption of fuel vapor to the adsorbent 13.
A fifth embodiment of a fuel pump control device according to the present invention will be described in detail referring to the accompanying drawing.
Accordingly, in addition to the same operations and advantages as in the second embodiment, the fifth embodiment in which the inside of the housing 12 communicates with atmosphere through the vent slot 15b can prevent the internal pressure in the housing 12 from becoming higher than the atmospheric pressure. It is therefore possible to prevent the internal pressure in the housing 12 from abnormally rising than saturated vapor pressure of the fuel vapor, thereby facilitating adsorption of fuel vapor to the adsorbent 22.
A sixth embodiment of a fuel pump control device according to the present invention will be described in detail referring to the accompanying drawing.
Accordingly, in addition to the same operations and advantages as in the third embodiment, the sixth embodiment in which the inside of the housing 12 communicates with atmosphere through the vent slot 15b can prevent the internal pressure in the housing 12 from becoming higher than the atmospheric pressure. It is therefore possible to prevent the internal pressure in the housing 12 from abnormally rising than saturated vapor pressure of the fuel vapor, thereby facilitating adsorption of fuel vapor to the adsorbent 22.
A seventh embodiment of a fuel pump control device according to the present invention will be described in detail referring to the accompanying drawing.
Accordingly, in addition to the same operations and advantages as in the fourth embodiment, the sixth embodiment in which the control device 31 is fixed to the inner side of the mounting plate 35 can made the pump module 34 including the control device 31 compact as compared with in the fourth embodiment. Furthermore, the vent slot 15b of the control device 31 communicates with the outside through the communication tube 37, the filter 38, and the vent hole 36a, so that the liquid containing fuel components is unlikely to leak to the outside through the vent hole 36a.
An eighth embodiment of a fuel pump control device according to the present invention will be described in detail referring to the accompanying drawing.
Accordingly, the fuel pump control device 39 of this embodiment can also provide the same operations and advantages as in the aforementioned embodiments in relation to the adsorbent 13 housed in the housing 45. In this embodiment, additionally, the control device 39 is provided integral with the mounting plate 41, and the case 42 integral with the mounting plate 41 constitutes the housing 45. Thus, the control device 39 can be designed compact in the pump module 40. The case 42 constituting the housing 45 protrudes upward from the mounting plate 41 and similarly other components protrude upward from the mounting plate 41. Therefore, protrusion of the case 42 of the control device 39 will not cause any problem in loading the fuel tank 3 in a vehicle. Only a small part of the control device 39, i.e., the cup 44 is placed in the fuel tank 3, thus reducing interference with the reserve cup 5 and the fuel pump 6. With the filter 38 provided over the vent hole 42a of the case 42, the liquid containing fuel components and others is unlikely to leak to the outside through the vent hole 42a.
The present invention is not limited to the above embodiment(s) and may be embodied in other specific forms without departing from the essential characteristics thereof.
For instance, in the first embodiment, the outer surface of the control circuit unit 17 is entirely coated with the coating material. As shown in
While the presently preferred embodiment of the present invention has been shown and described, it is to be understood that this disclosure is for the purpose of illustration and that various changes and modifications may be made without departing from the scope of the invention as set forth in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2007-261825 | Oct 2007 | JP | national |
