JP2007062840A - Tank cap - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transmit a rotation of a cap knob directly to a cap body without utilizing a torque limiting function of a ratchet mechanism in case of rotating the cap knob while strongly pushing-in the cap knob to an oil supply port tube when mounting a tank cap in the oil supply port tube of a fuel tank. <P>SOLUTION: The cap knob 19 of the tank cap is connected to a cap body 20 so that the cap knob 19 is movable between a push position P and a push-releasing position N along the axial direction of the cap body 20. There are mounted between the cap knob 19 and the cap body 20 an urging means 20c urging the cap knob 19 to the direction of the push-releasing position N and engagement means 40 and 41 which directly connect the cap knob 19 and the cap body 20 in a rotational direction in accordance with the movement of the cap knob 19 to the push position P while resisting to the urging force of the urging means 20c. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a cap body having a threaded portion that is screwed into a fuel tank of a fuel tank, a cap knob that is rotatably connected to the cap body and gripped by an operator, and a gap between the cap knob and the cap body. A ratchet mechanism that is arranged so as to be connected in the rotational direction and rotates the cap knob idle when the rotational torque in the tightening direction of the cap knob with respect to the cap body exceeds a predetermined value, and is attached to the upper end of the oil filler cylinder in the cap body. The present invention relates to an improvement of a tank cap including a packing closely contacting a formed sealing surface.

Such a tank cap is already known as disclosed in, for example, Patent Document 1.
Japanese Patent No. 2618420

  With conventional tank caps, when the fuel tank is installed in the filler cylinder, if the cap knob is rotated while being pushed firmly into the filler cylinder, the friction resistance between the packing provided on the cap body and the filler cylinder is reduced. The excessive increase may cause the cap knob to run idle due to the torque limiting function of the ratchet mechanism before the cap body is securely screwed into the filler cylinder.

  The present invention has been made in view of the above points. When the fuel tank is attached to the fuel filler cylinder, if the cap knob is rotated while being strongly pushed into the fuel filler cylinder, the torque limit of the ratchet mechanism is reduced. An object of the present invention is to provide the tank cap that can ensure the mounting to the fuel filler cylinder by transmitting the rotation of the cap knob directly to the cap body without functioning.

  In order to achieve the above object, the present invention provides a cap body having a threaded portion that is screwed into a fuel filler cylinder of a fuel tank, and a cap knob that is rotatably connected to the cap body and is gripped by an operator. The ratchet mechanism is arranged to connect the cap knob and the cap body in the rotational direction, and is attached to the cap body for rotating the cap knob idly when the rotational torque in the tightening direction of the cap knob with respect to the cap body exceeds a predetermined value. In a tank cap having a packing that is in close contact with the sealing surface formed at the upper end portion of the fuel filler tube, the cap knob is in the cap body, and the cap knob has a pressing position and a pressing release position along the axial direction with respect to the cap body. So that the cap knob can be moved between the cap knob and the cap body. An urging means for urging in the direction of the release position, and when the cap knob is moved to the pressing position against the urging force of the urging means, the engaging operation is performed to directly connect the cap knob and the cap body in the rotational direction. The first feature is that engagement means is provided.

  In addition to the first feature, the present invention connects the cap body and the cap knob so as to be relatively rotatable, and connects the cap knob to the cap body so as to be movable between the pressing position and the pressing release position. Therefore, the cap body and the cap knob are each provided with a shaft portion having an annular connecting groove on the peripheral surface and a connecting claw that engages with the connecting groove so as to be rotatable and movable in the axial direction. A flange portion facing the axial end surface of the cap is formed on the cap body, and the engagement surfaces of the coupling claw and the flange portion are engaged with and disengaged from each other according to the movement of the cap knob between the pressing position and the pressing release position. A second feature is that the concave portions and the projections constituting the coupling means are formed.

  Furthermore, in addition to the second feature, the present invention is provided with a plurality of the recesses and protrusions, and a part of the recesses and the protrusions can always be engaged, and the rest cannot be engaged. The urging means is configured such that the urging means is arranged so as to oppose each other, and the flange portion is provided with elasticity to urge the cap knob to the pressing release position via the protrusion which is not engaged with the concave portion. Is the third feature.

  Furthermore, in the present invention, in addition to the second or third feature, the upper surface of the annular packing mounting groove formed in the cap body for mounting the packing is configured by the lower surface of the flange portion. Features.

  According to the first feature of the present invention, when the cap knob is strongly pushed into the fuel filler cylinder when the tank cap is attached to the fuel filler cylinder, the engaging means engages and the cap knob and the cap are engaged. Since the bodies are directly connected, the rotational torque in the tightening direction of the cap knob can be directly transmitted to the cap body without going through the ratchet mechanism, so that the cap body can be reliably screwed into the oil filler tube. .

  According to the second feature of the present invention, it is possible to easily configure the engaging means by using the connecting structure that enables relative rotation between the cap body and the cap knob, and to simplify the structure of the tank cap. Can contribute.

  According to the third feature of the present invention, by applying elasticity to the flange portion having the recess or protrusion of the engaging means, the urging means can be easily configured, and the structure of the tank cap can be simplified. Can contribute.

  According to the fourth feature of the present invention, the flange portion having the recess or protrusion of the engaging means can be effectively used for forming the annular packing mounting groove, which contributes to the simplification of the structure of the tank cap. obtain.

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

  FIG. 1 is a front view of a general-purpose engine according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view of a fuel tank attached to the engine, and FIG. 3 is an enlarged view of a part 3 in FIG. 4 is an operation explanatory view corresponding to FIG. 3, FIG. 5 is an enlarged view of part 4, FIG. 5 is an enlarged view of part 5 of FIG. 3, FIG. Is a sectional view taken along line 7-7 in FIG. 3, and FIG. 8 is a plan view of the cap body alone in the tank cap.

  First, in FIG. 1, a symbol E indicates a general-purpose four-cycle engine that serves as a power source for various working machines. The engine E includes a crankcase 2 that supports a crankshaft 1 that is disposed in the horizontal direction, and a cylinder portion 3 that projects obliquely upward from the crankcase 2. A fuel tank T to be supported is disposed, and a carburetor 4 is attached to one side of the cylinder portion 3, and an air cleaner 6 connected to the carburetor 4 via an intake duct 5 is provided on the side of the fuel tank T. Are arranged directly above the cylinder portion 3.

  In FIG. 2, each of the fuel tanks T has a bowl-like shape, and an upper tank half 7 and a lower tank half 8 that face each other to define a fuel storage chamber 10, and a lower surface of the lower tank half 8 has a gap. The bottom plate 9 is covered with three members, and the three members 7, 8, 9 are caulked and joined together at their outer peripheral portions. The bottom plate 9 is attached to a bracket 11 fixed to the upper portion of the crankcase 2 by means of bolts 13 and 13 via mount rubbers 12 and 12, and the fuel tank T is elastically supported by the engine E.

  A fuel conduit 14 that opens to the fuel storage chamber 10 is connected to the bottom wall of the lower tank half 8 via a strainer 15, and fuel in the fuel storage chamber 10 filtered by the strainer 15 passes through the fuel conduit 14 by gravity. In this case, a labyrinth-like air vent that allows the fuel storage chamber 10 to breathe is provided in a tank cap C to be described later.

  As shown in FIGS. 2 and 3, an upper end portion of a steel-made fuel filler tube 18 is caulked and coupled to the central portion of the upper tank half 7 so that the upper end portion is exposed. A funnel-shaped sealing surface 18 a is formed on the exposed upper end portion of 18. A fuel filter 17 that filters the fuel injected into the fuel storage chamber 10 is connected to the lower end of the fuel filler cylinder 18.

  A tank cap C is attached to the fuel filler cylinder 18. The tank cap C includes a cap body 20, a cap knob 19 and a packing 23 as main components.

  3, 5, and 7, the cap body 20 is made of synthetic resin, and a cylindrical portion 20 a with a ceiling having a screw portion 24 that can be screwed to the inner peripheral surface of the fuel filler cylinder 18 on the outer periphery, A cylindrical shaft portion 20b projecting coaxially from the upper end surface of the cylindrical portion 20a and a flange 20c projecting in a radial direction from the upper end portion of the cylindrical portion 20a are provided, and an upper outer circumferential surface of the cylindrical portion 20a is provided. Is formed with an annular packing mounting groove 25 connected to the lower surface of the flange 20c. The packing 23 that is in close contact with the seal surface 18a is mounted in the packing mounting groove 25. The packing 23 includes an annular lower lip 23a that is in close contact with the seal surface 18a of the fuel filler cylinder 18, an annular upper lip 23b that is in contact with the lower surface of the flange 20c of the cap body 20 above the lower lip 23a, The inner peripheral ends of the lips 23a and 23b are integrally connected to each other, and the connecting portion 23c is mounted in the packing mounting groove 25 of the cap body 20.

  The cap body 20 is connected to a teaser 26 (see FIGS. 2 and 3) that prevents the tank cap C removed from the fuel filler cylinder 18 from dropping off.

  The cap knob 19 is made up of a cap inner 21 made of a synthetic resin and arranged immediately above the cap body 20, and a steel plate cap shell 22 that covers the upper and outer peripheral surfaces of the cap inner 21.

  As shown in FIGS. 5 to 7, the cap inner 21 has a plurality of projecting portions 21 a, 21 a.. The cylindrical cap shell 22 with a ceiling is fitted on the outer periphery of the cap inner 21. On the outer peripheral surface of the cap shell 22, a plurality of raised portions 30, 30... For receiving the plurality of protruding portions 21 a, 21 a. The cap claws 22 are fixed to the cap inner 21 by engaging the locking claws 31, 31... Thus, the cap knob 19 is configured. The raised portions 30, 30... Serve as a slip stopper when the cap shell 22 is rotated.

  An annular connection groove 27 is provided on the outer peripheral surface of the shaft portion 20 b of the cap body 20, and a plurality of L-shaped connection in an annular arrangement protruding from the lower surface of the cap inner 21 is provided in the connection groove 27. The claws 28, 28... Are engaged, whereby the cap body 20 and the cap knob 19 are connected so as to be relatively rotatable.

  Here, the rotation direction of the cap knob 19 (hereinafter referred to as the tightening direction) when the cap body 20 is screwed into the fuel filler cylinder 18 is A, and the opposite rotation direction (hereinafter referred to as the loosening direction) is B. A ratchet mechanism 35 that transmits the rotation of the cap inner 21 in the tightening direction A to the cap body 20 within a predetermined torque range and transmits the rotation of the cap inner 21 in the loosening direction B to the cap body 20 without slipping is provided by the cap inner 21. And the cap body 20.

  That is, as shown in FIGS. 3 and 7, the ratchet mechanism 35 includes a ratchet gear 36 formed on the cap body 20 and disposed concentrically with the cylindrical shaft portion 20b, and the cap inner 21. And a plurality of ratchet poles 37, 37... Which are elastically engaged with the ratchet gear 36, and when the cap shell 22 and the cap inner 21 are rotated in the tightening direction A, When the rotational torque exceeds a specified torque sufficient to properly bring the packing 23 into close contact with the seal surface 18a of the fuel filler cylinder 18, the ratchet poles 37, 37 ... slide out of the ratchet gear 36, and on the contrary, the cap shell 22 and When the cap inner 21 is loosened and rotated in the direction B, the ratchet poles 37, 37... And the ratchet gear Slip does not occur between 6, cap inner 21 and the cap body 20 is adapted to rotate integrally.

  3 to 5, the dimensions of the connection groove 27 of the cap body 20 and the plurality of connection claws 28, 28... Of the cap inner 21 are such that the connection claws 28, 28. The cap knob 19 can be moved in the axial direction between the lower pressing position P and the upper pressing release position N on the cap body 20. In the ratchet mechanism 35, the axial movement of the cap knob 19 is allowed by the axial slip at the meshing portion between the ratchet gear 36 and the ratchet pole 37 and the deflection of the ratchet pole 37.

  The protrusions 40, 40,... Are integrally formed on the lower end surfaces of the plurality of connection claws 28, 28, and a plurality of groove-shaped recesses that can be engaged with the protrusions 40, 40,. 41, 41... Are formed on the upper surface of the flange portion 20c of the cap body 20.

  As shown in FIGS. 7 and 8, the plurality of protrusions 40, 40... And the recesses 41, 41... Are always part of the protrusions 40 and the recesses 41 at any relative rotational positions of the cap knob 19 and the cap body 20. Can be engaged, and the remaining protrusions 40 and the recesses 40 are arranged so as to face each other so that they cannot be engaged. That is, the protrusions 40, 40... And the recesses 41, 41. The flange portion 20c is provided with elasticity that urges the cap knob 19 to the pressing release position N via the protrusion 40 that is not engaged with the recess 41.

  Next, the operation of this embodiment will be described.

  As described above, the plurality of recesses 41, 41... Of the flange portion 20c of the cap body 20 and the plurality of protrusions 40, 40. The protrusions 40 and the recesses 41 are always engageable at any relative rotational position, and the remaining protrusions 40 and the recesses 41 are arranged so as to face each other so that they cannot be engaged. The protrusion 40 that cannot be engaged comes into contact with the flat upper surface of the flange portion 20c. Moreover, since the flange portion 20c urges the protrusion 40 in contact with the upper surface thereof by its elastic restoring force, the urging force is transmitted from the protrusion 40 to the entire cap knob 19. As a result, the cap knob 19 is pushed up to the pressing release position N where the connecting claws 28, 28... Abut against the upper surface of the connecting groove 27 of the shaft portion 20 b of the cap body 20. Since the protrusion 40 and the recess 41 are also held in the detached state, the cap knob 19 can rotate in the tightening direction A with respect to the cap body 20.

  Therefore, when the tank cap C is attached to the filler cylinder 18, the cap knob 19 is aligned with the screw cylinder 24 without applying a particularly large pressing force to the cap knob 19, and the cap knob 19 is tightened. When rotating gently to A, the rotational torque is transmitted to the cap body 20 via the ratchet poles 37, 37,... And the ratchet gear 36 that mesh with each other, and the screw portion 24 is screwed to the fuel filler cylinder 18; The packing 23 can be brought into close contact with the seal surface 18 a of the fuel filler cylinder 18. When the packing 23 is properly brought into close contact with the seal surface 18a, when a torque greater than a specified value acts between the ratchet poles 37, 37... And the ratchet gear 36 meshing with each other, the ratchet poles 37, 37. Sliding from the ratchet gear 36 generates sound. Because of this, the operator can know that the tank cap C has been properly attached to the fuel filler cylinder 18, and the installation work is finished there. By such idling of the ratchet mechanism 35, damage to the screw portion 24 and the packing 23 due to excessive tightening can be prevented.

  However, when the tank cap C is mounted, if the cap knob 19 is pushed firmly into the filler cylinder 18 and moved to the pressing position P, the packing 23 is inserted into the filler opening before the screw portion 24 is screwed into the filler cylinder 18. The cylinder 18 is in close contact with the seal surface 18a.

  However, when the cap knob 19 is pushed down to the pressing position P, the projection 40 of the connecting claw 28 that opposes the concave portion 41 of the flange portion 20c engages with the concave portion 41 as shown on the right half side of FIG. As shown on the left half side of the figure, the protrusion 40 in contact with the upper surface of the flange portion 20c partially deflects the flange portion 20c, and does not hinder the engagement of some protrusions 40 and the recess 41. Accordingly, since the cap knob 19 and the cap body 20 are directly connected in the rotation direction via some of the engaged projections 40 and the recesses 41, when the cap knob 19 is rotated in the tightening direction A, the rotation The torque can be directly transmitted to the cap body 20 without using the ratchet mechanism 35, and the cap body 20 can be reliably screwed into the fuel filler cylinder 18.

  When the pressing force to the cap knob 19 is released, the entire cap knob 19 is interposed via the protrusion 40 by the repulsive force of the portion bent downward by the protrusion 40 not engaged with the recess 41 in the flange portion 20c. Are pushed up to the pressure release position N, and the tank cap C returns to a free state in which all the protrusions 40, 40... Are detached from the recesses 40, 40.

  By the way, the flange portion 20c of the cap body 20 has a concave portion 41 that is involved in the formation of the annular coupling groove 27 with which the coupling claws 28, 28. In addition, it is involved in the configuration of the engaging means between the cap knob 19 and the cap body 20, and is also involved in the configuration of the biasing means that is given elasticity and biases the cap knob 19 to the pressing release position N. This is involved in the formation of the packing mounting groove 25 in the cap body 20, thereby reducing the number of parts, simplifying the structure of the tank cap C, and contributing to cost reduction.

  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. For example, in the first feature of the present invention, a dedicated spring can be provided as the biasing means.

The front view of the general purpose engine which concerns on the Example of this invention. The longitudinal cross-sectional view of the fuel tank attached to the engine. 3 is an enlarged view of a part 3 in FIG. 2 (a sectional view taken along line 3-3 in FIG. 7). Action explanatory drawing corresponding to FIG. FIG. 5 is an enlarged view of part 5 of FIG. 3. FIG. 6 is a sectional view taken along line 6-6 of FIG. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 3. The top view of the cap body single-piece | unit in a tank cap.

Explanation of symbols

A ... Cap knob tightening direction B ... Cap knob loosening direction C ... Tank cap N ... Cap knob pressure release position P ... Cap knob Pressing position T ... Fuel tank 18 ... Filling port cylinder 18a ... Sealing surface 19 ... Cap knob 20 ... Cap body 20b ... Shaft 20c ... Flange Department (biasing means)
23... Packing 24... Screw part 25... Packing mounting groove 35... Ratchet mechanism 40 and 41.

Claims (4)

A cap body (20) having a threaded portion (24) screwed into the fuel filler cylinder (18) of the fuel tank (T), and is rotatably connected to the cap body (20) and held by an operator. The cap knob (19) is arranged to connect the cap knob (19) and the cap body (20) in the rotational direction, and the cap knob (19) rotates in the tightening direction (A) with respect to the cap body (20). A ratchet mechanism (35) that idles the cap knob (19) when the torque exceeds a predetermined value, and a seal surface (18a) that is attached to the cap body (20) and formed at the upper end of the fuel filler cylinder (18). In a tank cap with intimate packing (23),
The cap knob (19) can move to the cap body (20), and the cap knob (19) can move between the pressing position (P) and the pressing release position (N) along the axial direction with respect to the cap body (20). And a biasing means (20c) for biasing the cap knob (19) in the direction of the pressing release position (N) between the cap knob (19) and the cap body (20). When the cap knob (19) is moved to the pressing position (P) against the urging force of (20c), it engages and engages directly between the cap knob (19) and the cap body (20) in the rotational direction. Means (40, 41) and a tank cap. The tank cap according to claim 1,
The cap body (20) and the cap knob (19) are relatively rotatable, and the cap knob (19) is moved between the pressing position (P) and the pressing release position (N) with respect to the cap body (20). In order to be movably connected to the cap body (20) and the cap knob (19), the shaft portion (20b) having an annular connecting groove (27) on the peripheral surface and the connecting groove (27) are rotated and axially rotated. A connecting claw (28) that is movably engaged, and
The cap body (20) is formed with a flange portion (20c) facing the axial end surface of the connecting claw (28) on the cap body (20), and the facing surfaces of the connecting claw (28) and the flange portion (20c). Further, a recess (41) and a protrusion (40) constituting the engaging means are formed by disengaging from each other according to the movement of the cap knob (19) between the pressing position (P) and the pressing release position (N). A tank cap characterized by that. The tank cap according to claim 2,
A plurality of the recesses (41) and protrusions (40) are provided, and a part of the recesses (41) and the protrusions (40) can always be engaged, and the remaining parts cannot be engaged. The cap knob (19) is urged to the pressing release position (N) through the protrusion (40) which is arranged so as to be opposed to the flange portion (20c) and does not engage with the recess (41). A tank cap characterized in that the urging means is configured by applying elasticity. The tank cap according to claim 2 or 3,
A tank cap characterized in that the upper surface of an annular packing mounting groove (25) formed in the cap body (20) for mounting the packing (23) is constituted by the lower surface of the flange portion (20c).

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