This application is based on and incorporates herein by reference Japanese Patent Application No. 2004-10680 filed on Jan. 19, 2004.
The present invention relates to a fuel feed apparatus that feeds fuel received in a fuel tank to the outside of the fuel tank.
A fuel feed apparatus disclosed in JP-A-9-268957 is capable of stably feeding fuel from an inside of a fuel tank to the outside, even when an amount of fuel received in the fuel tank decreases. The fuel feed apparatus includes a sub-tank receiving a fuel pump and the like. The sub-tank is supported by a supporting member such that the sub-tank is axially displaceable relevant to a lid member that is provided to an opening formed in the fuel tank.
A biasing means such as a spring is provided between the sub-tank and the lid member such that the spring urges the sub-tank and the lid member in the direction, in which the sub-tank and the lid member are apart from each other. Therefore, the sub-tank can be pressed onto the inner bottom plane of the fuel tank, regardless of the inner volume of the fuel tank. As a result, fuel remaining around the sub-tank can be stably drawn into the sub-tank, even when liquid level of fuel decreases in the fuel tank.
A conventional fuel feed apparatus has supporting members such as metallic pipes that are arranged on both radially outer portions of the sub-tank. The biasing means is provided to the outer circumferential side of each of the supporting members arranged on both the radially outer portions of the sub-tank. Alternatively, the biasing means may be provided to the outer circumferential side of one of the supporting members, so that the number of components can be reduced. However, when the biasing means is provided to one of the supporting members, resilient force applied to both the lid member and the sub-tank becomes unstable. That is, the lid member and the sub-tank lose balance therebetween due to difference of resilient force applied by the biasing means. Accordingly, it is difficult to assemble the lid member to the sub-tank on the side of the supporting member, to which the biasing means is provided, due to instability of resilient force applied by the biasing means.
Besides, when the biasing means is provided to only one of the supporting members, the sub-tank may be inclined due to instability of resilient force. As a result, the supporting member, on which the biasing means is not provided, may be inclined. In this situation, the supporting member, on which the biasing means is not provided, slides against a supporting portion, which slidably supports the supporting member, in an inappropriate angle. Accordingly the supporting member does not smoothly slide with respect to the supporting portion, and the supporting member and the supporting portion are abraded with each other. Besides, the sub-tank may not be pressed onto the inner bottom plane of the fuel tank, and fuel may not be properly pumped into the sub-tank.
In view of the foregoing problems, it is an object of the present invention to produce a fuel feed apparatus that can be easily assembled even when a biasing means is provided to one of supporting members. It is another object of the present invention to produce a fuel feed apparatus, in which a lid member and a sub-tank are capable of smoothly displacing relative to each other even when a biasing means is provided to one of supporting members.
According to the present invention, a fuel feed apparatus is at least partially received in a fuel tank. The fuel feed apparatus includes a lid member, a sub-tank, a first supporting member, a second supporting member, a biasing means, a first supporting portion, and a guide portion. The lid member covers an opening portion formed in the fuel tank. The sub-tank is received in the fuel tank. The sub-tank includes a cylindrical portion and a bottom portion. The bottom portion is located on the opposite side as the lid member with respect to the cylindrical portion. The sub-tank receives a fuel pump. The first supporting member is arranged in a substantially end portion of the cylindrical portion in the radial direction of the cylindrical portion. The first supporting member supports the lid member and the sub-tank such that the lid member is capable of moving relative to the sub-tank in a substantially axial direction of the sub-tank.
The second supporting member is arranged in a substantially end portion of the cylindrical portion in the radial direction of the cylindrical portion. The second supporting member is arranged on a substantially opposite side as the first supporting member in the radial direction of the cylindrical portion. The second supporting member supports the lid member and the sub-tank such that the lid member is capable of moving relative to the sub-tank in the substantially axial direction of the sub-tank. The biasing means is arranged on the outer peripheral side of the first supporting member. The biasing means biases the lid member and the sub-tank to be apart from each other. The first supporting portion is provided to the cylindrical portion of the sub-tank. The first supporting portion slidably supports the first supporting member such that the first supporting member is capable of reciprocating through the first supporting portion in the substantially axial direction of the sub-tank. The guide portion is provided to the first supporting portion. The guide portion is arranged on the side of the lid member with respect to the first supporting portion. The guide portion at least partially surrounds the outer peripheral side of the first supporting member.
The first supporting portion is integrally formed with the cylindrical portion of the sub-tank. The first supporting portion inwardly protrudes from the cylindrical portion in a substantially radial direction of the cylindrical portion. The guide portion has a substantially cylindrical shape. The guide portion further surrounds the outer peripheral side of the biasing means.
The fuel feed apparatus further includes a second supporting portion that is provided to the cylindrical portion of the sub-tank. The second supporting portion slidably supports the second supporting member such that the second supporting member is capable of reciprocating through the second supporting portion in the substantially axial direction of the sub-tank. The second supporting portion defines a guide plane and a groove portion. The guide plane is capable of sliding with respect to the second supporting member in the inner peripheral side of the guide plane. The groove portion divides the guide plane into at least two planes in the circumferential direction of the guide plane.
The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings:
As shown in
The lid member 11 has a discharge pipe 12 and an electric connector 13. Fuel is discharged from a fuel pump 141 (
The first shaft 21 is supported by a first supporting portion 31 (
The first and second shafts 21, 22 are made of a metallic material, such as stainless steel or aluminum, or a nonmetallic material such as resin. As referred in
The sub-tank 20 receives the fuel pump 141, a fuel filter, a suction filter, a pressure regulator, a first jet pump (none shown) and a second jet pump 40 (
As shown in
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As referred in FIGS. 2 to 4, a guide portion 50 is provided to the first supporting portion 31 on the side of the lid member 11. The guide portion 50 has a wall portion 51 that substantially circumferentially extends continuously from a substantially arc-shaped circumferential periphery of a part of the cylindrical portion 27 of the sub-tank 20. The wall portion 51 of the guide portion 50 axially extends from the first supporting portion 31 on the side of the lid member 11. The first supporting portion 31 radially internally protrudes in the substantially radial direction of the sub-tank 20. The wall portion 51 extends to the side of the lid member 11 along the outer periphery of the first supporting portion 31. Thus, the wall portion 51 cylindrically covers the first supporting portion 31 on the side of the lid member 11. The inner diameter of the guide portion 50 of the wall portion 51 and the inner diameter of the first supporting portion 31 are different from each other, so that the guide portion 50 and the first supporting portion 31 form a step 52 therebetween. The axially end portion of the first shaft 21 and the axially end portion of the spring 23, which are on the opposite side as the lid member 11, are received in a space defined by the inner periphery of the guide portion 50, which is in a substantially cylindrical shape. The end portion of the spring 23, which is on the opposite side as the end portion press-inserted into the lid member 11, makes contact with the step 52 formed between the guide portion 50 and the first supporting portion 31.
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The substantially cylindrical guide portion 50 is provided to the first supporting portion 31 on the side of the lid member 11 thereof, so that the spring 23, which is provided to the radially outer peripheral side of the first shaft 21, is received in the guide portion 50. When the lid member 11 is assembled to the sub-tank 20, the first and second shafts 21, 22 are respectively press-inserted into the press-insertion portions 15 of the lid member 11. Subsequently, the spring 23 is attached to the outer periphery of the first shaft 21 such that the first shaft 21 is inserted into the inner periphery the spring 23. The first shaft 21 is inserted into the first supporting portion 31 of the sub-tank 20, and the second shaft 22 is inserted into the second supporting portion 32, after the spring 23 is attached to the first shaft 21. In this situation, the spring 23 is received inside the guide portion 50, so that the spring 23 is positioned within the guide portion 50, and is restricted in the radial direction of the spring 23. Besides, the spring 23 is positioned by the step 52, which is formed between the guide portion 50 and the first supporting portion 31, in the axial direction of the spring 23. The spring 23 is guided by the guide portion 50 in the radial direction of the spring 23, so that the spring 23 is properly aligned in the guide portion 50. Besides, the first shaft 21 is guided by the spring 23 received in the guide portion 50 such that the first shaft 21 is smoothly inserted into the first supporting portion 31 of the sub-tank 20. As a result, the lid member 11, the sub-tank 20, the first and second shafts 21, 22 can be easily assembled to each other, even when resilient force of the spring 23 is applied to the lid member 11 and the sub-tank 20.
The second supporting portion 32 extends in a substantially axial direction thereof, and the guide plane 32a also extends in a substantially axial direction of the second supporting portion 32 for guiding movement of the second shaft 22 that slides over the guide plane 32a. Therefore, inclination of the second shaft 22 with respect to the second supporting portion 32 can be reduced. Besides, the guide plane 32a is divided by the groove portions 36 in the circumferential direction of the second supporting portion 32. Thus, the area of a connecting plane between the guide plane 32a and the second shaft 22 decreases, even the axial length of the second supporting portion 32, i.e., the guide plane 32a extends. Therefore, frictional resistance arising between the second shaft 22 and the second supporting portion 32 decreases, so that the second shaft 22 is capable of smoothly sliding over the inner periphery of the second supporting portion 32. Furthermore, the axial length of the first supporting portion 31 is different from the axial length of the second supporting portion 32. Besides, the axial position of the first supporting portion 31 is different from the axial position of the second supporting portion 32 with respect to the axial direction of the sub-tank 20. That is, the supporting point, i.e., pivot or fulcrum of the first shaft 21 with respect to the first supporting portion 31 is different from the supporting point of the second shaft 22 with respect to the second supporting portion 32. As a result, the second shaft 22 is not apt to be inclined in the second supporting portion 32, and the second shaft 22 can be smoothly guided by the second supporting portion 32, even when the spring 23 is provided to the first shaft 21. Therefore, the lid member 11 is capable of smoothly moving relative to the sub-tank 20, even when the inner volume of the fuel tank 100 is changed. Besides, the vertical position, i.e., axial position of the top end portion of the first supporting portion 31 is different from that of the second supporting portion 32. When the lid member 11, which is assembled to the first and second shafts 21, 22, is attached to the sub-tank 20, the second shaft 22 is inserted into the second supporting portion 32, while the spring 23 is received in the guide portion 50, and subsequently, the first shaft 21 is inserted into the inner wall 31a of the first supporting portion 31. When the first shaft 21 is inserted into the inner wall 31a of the first supporting portion 31, the second shaft 22 is already inserted into the second supporting portion 32, and the second shaft 22 is radially positioned by the second supporting portion 32. Therefore, the first shaft 21 is already positioned roughly around the inner wall 31a of the first supporting portion 31. Thus, the first shaft 21 can be easily aligned with respect to the inner wall 31a of the second supporting portion 32, and can be easily inserted into the inner wall 31a, even while resilient force of the spring 23 is applied to the lid member 11.
The first supporting portion 31 has the groove portions 34, and the second supporting portion 32 has the groove portions 36. Therefore, frictional resistance arising between the first shaft 21 and the first supporting portion 31 decreases, and frictional resistance arising between the second shaft 22 and the second supporting portion 32 also decreases. Foreign material may intrude into both the sliding portion between the first supporting portion 31 and the first shaft 21, and the sliding portion between the second supporting portion 32 and the second shaft 22. Even in this situation, the foreign material can be removed and exhausted from the sliding portions, which are formed between the first and second supporting portions 31, 32 and the first and second shafts 21, 22, through the groove portions 34, 36. Therefore, the sliding portions can be protected from increasing of frictional resistance therebetween due to foreign material intruding into the sliding portions, so that the lid member 11 and the sub-tank 20 can be maintained to be capable of smoothly moving axially relative to each other.
The above structure is not limited to be applied to the above fuel feed apparatus 10. The above structure may be applied to a fuel feed apparatus 110 shown in
The above structure may be applied to a fuel feed apparatus that has a structure different from that of the above fuel feed apparatuses 10, 110. The above structure is not limited to be applied to the fuel tank in a saddleback shape, and the shape of the fuel tank may be changed as appropriate. Besides, components received in the sub-tank may be changed as appropriate.
Various modifications and alternations may be diversely made to the above embodiments without departing from the spirit of the present invention.
Number | Date | Country | Kind |
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2004-10680 | Jan 2004 | JP | national |