JP2008038614A - Fuel gauge - Google Patents

Abstract

An object of the present invention is to eliminate fogging on the inner surface of a lens by preventing condensation freezing on the inner surface of the lens due to fuel vapor generated in a fuel tank.
A gauge housing 10 attached to an attachment port 7 on an upper surface wall of a fuel tank T, and a pointer 15 which is accommodated in the gauge housing 10 and moves in accordance with the rising and lowering of a liquid level of stored fuel in the fuel tank T. A fuel gauge comprising a lens holder 20 that closes the upper end of the gauge housing 10 and a transparent lens 21 that is fitted into a viewing window 19 provided in the lens holder 20. 25 is attached to prevent the fuel vapor generated in the fuel tank T from entering the gauge housing 10 and prevent the fuel vapor from dew condensation on the inner surface of the lens.
[Selection] Figure 7

Description

  The present invention relates to a gauge housing that is attached to a wall portion of a fuel tank so as to pass through, a pointer that is accommodated in the gauge housing and is displaced in accordance with the rising and lowering of a liquid level of stored fuel in the fuel tank, a gauge housing The present invention relates to an improvement in a fuel gauge including a lens holder that closes an upper end of the lens and a transparent lens that is fitted into a viewing window provided in the lens holder.

Such a fuel gauge is already known as disclosed in Patent Document 1, for example.
JP-A-11-208295

  In a fuel gauge of a fuel tank installed near an engine used outdoors, fogging occurs on the inner surface of the lens, particularly in cold regions, and it often becomes difficult to visually check the internal pointer.

  The present inventors investigated the cause of the occurrence of fogging on the inner surface of the lens as follows. In other words, when the engine is left after operation, the fuel tank is warmed by the residual heat of the engine, and a part of the fuel in the inside rises as a vapor and condenses on the inner surface of the lens of the fuel gauge. Due to the cooling of the lens by the outside air, the condensation on the inner surface of the lens freezes, and this condensation freezes the inner surface of the lens.

  The present invention has been made in view of such circumstances, and prevents condensation on the inner surface of the lens due to fuel vapor generated in the fuel tank, thereby eliminating fogging on the inner surface of the lens and always providing an accurate guideline. It aims at providing the said fuel gauge which can be visually observed.

  In order to achieve the above object, the present invention provides a gauge housing that is attached to a wall portion of a fuel tank so as to penetrate through the wall, and accommodates the rising and lowering of the liquid level of stored fuel in the fuel tank. In a fuel gauge having a pointer that displaces, a lens holder that closes the upper end of the gauge housing, and a transparent lens that fits into a viewing window provided in the lens holder, a cover that covers the lower surface of the gauge housing is provided. The first feature is to prevent the fuel vapor generated in the fuel tank from entering the gauge housing.

  In addition to the first feature, the present invention has a second feature that the lens is made of glass.

  According to the first feature of the present invention, when the engine is left in operation in a cold region, the fuel tank is warmed by the residual heat of the engine, and a part of the fuel inside the fuel tank rises as steam, Even towards the gauge, the cover prevents the fuel vapor from entering the gauge housing, so that the condensation of the fuel vapor on the inner surface of the lens can be greatly reduced. Even when cooled, the fogging of the inner surface of the lens due to condensation condensation can be eliminated, and good visibility of the pointer can always be ensured.

  According to the second feature of the present invention, since the glass lens has high thermal conductivity and the volume inside the gauge housing covered with the cover is extremely small, the inside of the gauge housing is quickly brought out by outside air. Because it is cooled, even if fuel vapor penetrates into the gauge housing somewhat, it almost liquefies before coming into contact with the inner surface of the lens and can effectively prevent condensation on the inner surface of the lens. Can effectively prevent fogging.

  Embodiments of the present invention will be described below on the basis of preferred embodiments of the present invention shown in the accompanying drawings.

  1 is a side view of an engine equipped with a fuel tank with a fuel gauge of the present invention, FIG. 2 is a plan view of the fuel tank, FIG. 3 is an enlarged view of a fuel gauge portion in FIG. 2, and FIG. -4 sectional view, FIG. 5 is an enlarged view of the main part of FIG. 4, FIG. 6 is a sectional view taken along arrow 6 in FIG. 5, FIG. 7 is a sectional view taken along line 7-7 in FIG. FIG. 9 is a cross-sectional view corresponding to FIG. 8, showing another embodiment of the present invention.

  In FIG. 1, an engine body 1 of a general-purpose four-stroke engine E includes a crankcase 2 having a mounting seat 2a at a lower portion, and a cylinder block 3 that is integrally connected to the crankcase 2 and that is inclined upward. A fuel tank T disposed immediately above the crankcase 2 is attached, and an air cleaner A disposed directly above the cylinder block 3 is attached.

  As shown in FIGS. 2 to 4, the upper surface wall of the fuel tank T is provided with a fuel filler port 6 that is closed by a tank cap 5 at the center, and the fuel remaining in the fuel tank T is aligned with the fuel filler port 6. A fuel gauge G for detecting and displaying the amount is provided. The fuel gauge G will be described with reference to FIGS.

  7 to 8, the fuel gauge G is connected to the cylindrical gauge housing 10, the guide cylinder 11 fitted to the inner peripheral surface of the gauge housing 10, and the gauge housing 10 and the guide cylinder 11. Further, a pivot shaft 12 that penetrates the shaft 12 in a lateral direction and a float arm 13 having a hub 13a rotatably supported on the pivot shaft 12 in the guide cylinder 11 are provided. A float 14 (see FIG. 2 and FIG. 4) is attached to the tip of the head, and a T-shaped pointer 15 that extends upward and swings horizontally in conjunction with the float arm 13 is integrated with the hub 13a. Is formed.

  The guide cylinder 11 has a spherical ceiling wall 11a centered on the axis of the pivot 12, and a guide slit for guiding the swing of the arm portion 15a of the T-shaped pointer 15 is provided on the ceiling wall 11a. 16 is provided. The indicator 15b at the tip of the pointer 15 extends in a direction orthogonal to the guide slit 16, and the position of the indicator 15b indicates the remaining amount of fuel in the fuel tank T.

  That is, on the upper surface of the lens holder 20, the symbol F (which means Full) is adjacent to one end of the guide slit 16, and the symbol E (which means Empty) is adjacent to the other end. . Thus, the indicator 15b of the pointer 15 is interlocked with the float 14 so as to approach the symbol F as the float 14 rises and approach the symbol E as the float 14 descends.

  The ceiling wall of the gauge housing 10 is provided with an opening 18 through which the pointing portion 15b of the pointer 15 faces, and a lens holder 20 having a viewing window 19 corresponding to the opening 18 in the center is coupled to the upper end of the gauge housing 10. The A lens 21 made of a transparent material, preferably transparent glass, is mounted on the viewing window 19 via a packing 22, and the movement of the pointer 15 can be seen through the lens 21 from the outside. The coupling of the gauge housing 10 and the lens holder 20 is achieved by elastic engagement of a plurality of sets of locking claws 23 and 24 formed integrally on these opposing surfaces.

  The cover 25 which covers the open surface is attached to the open lower end part of the gauge housing 10. The cover 25 includes a bottom portion 25a that covers the open surface of the gauge housing 10, and a cylindrical portion 25b that stands up from the outer peripheral portion of the bottom portion 25a and fits to the outer periphery of the gauge housing 10. An annular groove 27 that fits into the lower end of the gauge housing 10 is formed. The cylindrical portion 25b is provided with a plurality of locking pieces 29 having locking holes 30 which are provided with elasticity by cutting slits 28 and 28 (see FIG. 5) on both sides.

  A plurality of locking claws 31 are integrally formed on the outer peripheral surface of the gauge housing 10, and by engaging the locking holes 30 of the locking pieces 29 with the locking claws 31, the cover 25 is attached to the gauge housing 10. The fitting position is fixed. The cover 25 is provided with a notch 32 (see FIGS. 6 to 8) that allows the float arm 13 to swing from the bottom 25 a to the cylindrical portion 25 b and the gauge housing 10. A flange 10a is integrally formed on the outer periphery of the upper end portion of the gauge housing 10, and an annular packing 33 is tightly arranged on the outer periphery of the gauge housing 10 immediately below the flange 10a.

  In the above, the gauge housing 10, the guide cylinder 11, the hub 13a, and the lens holder 20 are made of synthetic resin.

  In attaching the fuel gauge G thus configured to the fuel tank T, the float 14 is inserted into the fuel tank T from the cylindrical attachment port 7 on the upper surface wall of the fuel tank T, and then the gauge housing 10 is attached to the attachment port 7. And the packing 33 is brought into close contact with the inner peripheral surface of the attachment port 7. At that time, the flange 10a of the gauge housing 10 abuts on the upper surface of the fuel tank T, and an annular step 33a formed on the outer periphery of the lower end of the packing 33 abuts on the lower end surface of the attachment port 7, thereby 10 is held in the fuel tank T.

  In order to remove the fuel gauge G attached to the attachment port 7, the gauge housing 10 is integrally formed with a plurality of retaining pieces 34 projecting obliquely upward from the lower portion thereof. , When the fuel gauge G is attached, it has flexibility to allow passage to the attachment port 7.

  Next, the operation of this embodiment will be described.

  In the fuel tank T, the float 14 floats on the liquid level of the stored fuel. Therefore, when the liquid level drops due to the consumption of fuel accompanying the operation of the engine E, the float 14 also drops. Thus, the float arm 13 is swung downward, and in conjunction with this, the indicating portion 15b of the pointer 15 moves to the symbol E side. Therefore, the remaining amount of fuel in the fuel tank T can be known by viewing the relative position of the pointer 15 with the symbol E through the lens 21.

  Further, as the fuel level in the fuel tank T is raised, the fuel level inside the fuel tank T rises, and accordingly, the indicator 15b of the pointer 15 moves to the symbol F side. Therefore, the fuel supply state to the fuel tank T can be known by viewing the relative position of the pointer 15 with the symbol F through the lens 21.

  By the way, when the engine E is left after operation in a cold region, the fuel tank T is warmed by the residual heat of the engine E, and a part of the fuel in the inside rises as a vapor, and even toward the fuel gauge G. In the fuel gauge G, most of the open lower surface of the gauge housing 10 is covered with a cover 25, and the inside of the gauge housing 10 communicates with the upper space in the fuel tank T through a notch 32 having a relatively small opening area. Therefore, the cover 25 prevents the fuel vapor from entering the gauge housing 10, and the amount of fuel vapor passing through the notch 32 is extremely small. Therefore, the condensation of fuel vapor on the inner surface of the lens 21 can be greatly reduced.

  Moreover, since the lens 21 of the viewing window 19 of the fuel gauge G is made of glass having high thermal conductivity, and the volume of the gauge housing 10 covered with the cover 25 is extremely small, Since it is cooled early by the outside air, even if fuel vapor enters the gauge housing 10 from the notch 32, most of the fuel vapor is liquefied before coming into contact with the inner surface of the lens 21 and effectively prevents condensation on the inner surface of the lens 21. Can do.

  If condensation on the inner surface of the lens 21 is reduced or prevented in this way, even if the lens 21 is further cooled by cold outside air, the fogging of the lens 21 due to condensation freezing can be eliminated. Therefore, the visibility of the pointer 15 can always be ensured.

  Next, another embodiment of the present invention shown in FIG. 9 will be described.

  In this embodiment, the cover 25 is connected to the gauge housing 10 by passing the pivot 12 through them. A retaining piece 34 is formed integrally with the cover 25. Since the configuration is the same as that of the previous embodiment, portions corresponding to those of the previous embodiment in FIG. 9 are denoted by the same reference numerals, and redundant description is omitted.

  The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention.

The side view of the engine carrying the fuel tank with a fuel gauge of this invention. The top view of the said fuel tank. The enlarged view of the fuel gauge part in FIG. 4-4 sectional drawing of FIG. 4 is an enlarged view of the main part. FIG. 6 is a view taken in the direction of arrow 6 in FIG. 5. FIG. 7 is a cross-sectional view taken along line 7-7 of FIG. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. FIG. 8 is a diagram corresponding to FIG. 7 showing another embodiment of the present invention.

Explanation of symbols

E ... Engine 3 ... Cylinder block 3a ... Cylinder bore 4 ... Gasket 5 ... Cylinder head 5c ... Outer end surface = Inclined surface 6 ... ··· Main connection bolt 7 ··· Auxiliary connection bolt 12 ··· Crankshaft 35 ··· Valve mechanism 36 · · · Cam shaft 37 · · · Timing transmission device 45 · · · Drive Rotating member (drive pulley)
46... Driven rotation member (driven pulley)
47... Endless transmission member (timing belt)
48 ... Timing transmission chamber 48a ... Lower chamber 48b ... Intermediate chamber 48c ... Upper chamber 55 ... Work window 57 ... Lid

Claims (2)

A gauge housing (10) attached through the wall of the fuel tank (T) and the gauge housing (10). The gauge housing (10) accommodates the rise and fall of the liquid level of the stored fuel in the fuel tank (T). And a pointer (15) that displaces, a lens holder (20) that closes the upper end of the gauge housing (10), and a transparent lens (21) that is fitted into a viewing window (19) provided in the lens holder (20) In a fuel gauge comprising
The gauge housing (10) is provided with a cover (25) that covers the lower surface of the gauge housing (10) so as to prevent the fuel vapor generated in the fuel tank (T) from entering the gauge housing (10). gauge. The fuel gauge according to claim 1, wherein
A fuel gauge, wherein the lens (21) is made of glass.

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