JP4863925B2 - General purpose engine - Google Patents

Description

  The present invention relates to a general-purpose engine, and more particularly to a general-purpose engine in which a canister is accommodated in a fuel tank in a compact manner.

  In general-purpose engines, various considerations are taken when installing a canister (evaporative fuel adsorbing device) so as not to enlarge the working machine.

  Patent Document 1 discloses a configuration in which a housing recess recessed inward of the fuel tank is formed at the bottom of the fuel tank, and the canister is housed in the housing recess. In the configuration of Patent Document 1, the evaporated fuel in the fuel tank is guided to a canister via a pipe line (for example, a rubber pipe) disposed in the tank.

Japanese Patent Laying-Open No. 2005-163689

  According to the above-mentioned Patent Document 1, since the housing recess for housing the canister is formed at the bottom of the fuel tank, the canister can be housed in a compact manner. However, since the evaporated fuel in the fuel tank is configured to be guided to the canister via a pipe line arranged in the tank, when this pipe line has a hole due to secular change or the like, The condition is bad because the fuel enters the canister through the pipeline. In addition, when the pipeline is clogged, it cannot be easily handled, and a large-scale work such as dismantling the fuel tank is required. Furthermore, since the pipe line connected from the canister to the intake system connected to the engine body has to be bypassed around the fuel tank, the pipe line around the canister cannot be compactly gathered.

  The present invention has been made in view of the above-mentioned problems, and its purpose is to maintain a canister that is compactly accommodated and a pipe that leads the evaporated fuel from the tank cap to the canister is exposed without passing through the inside of the fuel tank. The pipe connecting the canister and the intake system connected to the engine body is to provide a general-purpose engine that can be piped in the shortest without bypassing the fuel tank.

In order to achieve the above object, a general-purpose engine according to claim 1 is a general-purpose engine having a fuel tank and an engine body, and a canister that adsorbs evaporated fuel generated in the fuel tank is formed in the fuel tank. A pipe for sucking evaporated fuel from the fuel tank is exposed from the fuel tank and piped to the canister, and the canister is connected to the intake system of the engine body. A pipe for purging the evaporated fuel is provided through a gap between the canister and the through hole.

  By adopting this configuration, the canister can be accommodated compactly without enlarging the periphery of the fuel tank. In addition, the pipe for guiding the evaporated fuel from the tank cap to the canister can be piped by being exposed from the tank cap without passing through the inside of the fuel tank, and can be easily maintained. In addition, the pipe connecting the canister and the intake system connected to the engine body can be routed as short as possible through the gap between the canister and the inner wall surface of the through hole without detouring the fuel tank, so the pipe around the canister can be gathered compactly. be able to.

  The general-purpose engine according to claim 2, wherein the canister is detachably disposed in the through hole by a mounting bracket, and the mounting bracket is fitted into the through hole and a holding member for holding the canister. And a fixing member that exerts a biasing force on the inner wall surface of the through hole. Therefore, the canister is securely held by the holding member of the mounting bracket, and the mounting bracket holding the canister is securely fixed to the through hole of the fuel tank because the fixing member has a biasing force.

  The general-purpose engine according to claim 3, wherein the fixing member includes a base portion to which the holding member is attached, and arc-shaped wing portions extending from both ends of the base portion, It has an engaging part which engages with a component of the canister and holds the canister.

  By adopting this configuration, the canister can be easily attached to the holding member by the engaging operation, and the fixing member is composed of a base portion and an arcuate wing portion extending from both ends of the base portion. Therefore, it is easy to fit the fitting into the through hole.

  The general-purpose engine according to claim 4 is characterized in that the fixing member is provided with a concave groove extending in an extending direction of the base portion and the wing portion. Therefore, the urging force is stabilized, the durability of the mounting bracket is improved, and it can withstand repeated use.

  The general-purpose engine according to claim 5, wherein the fixing member is provided with a protruding part for pulling out the canister that protrudes outward from the through hole in a state where the canister is loaded in the through hole. Features. Therefore, this protrusion can be easily picked with pliers or the like, and the mounting bracket can be easily pulled out from the through hole of the fuel tank.

According to the general-purpose engine of the present invention,
(1) The canister can be accommodated compactly without enlarging the periphery of the fuel tank.
(2) Canister can be easily attached and detached.
(3) Since the pipe for feeding the evaporated fuel to the canister is exposed, maintenance is easy.
(4) The pipe connecting the canister and the intake system connected to the engine main body can obtain an effect that it can be installed in the shortest time.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view showing an embodiment of a general-purpose engine of the present invention. FIG. 2 is a schematic plan view of FIG. In any case, parts other than the characteristic part of the present invention are omitted, and the main part is shown in a partial sectional view. Furthermore, although an engine main body exists in the lower part of the figure of the fuel tank 10, the illustration thereof is omitted.

  The fuel tank 10 includes a tank main body portion 12 having a constant volume, a through hole 14 formed so as to penetrate above and below the tank main body portion 12, and a tank cap 16. The through hole 14 is for accommodating the canister 20, has an inner diameter larger than the outer diameter of the canister 20, and is formed while keeping the sealed state of the fuel tank. The through hole 14 has a substantially cylindrical shape, and as shown in FIG. 1, the upper portion 14b is formed to have substantially the same diameter, and the lower portion 14a is formed to gradually increase in diameter toward the lower side. The tank cap 16 is provided near the center of the upper portion of the tank main body 12, and an evaporated fuel outlet 27 is provided at the upper portion of the tank cap 16 to guide the evaporated fuel in the fuel tank 10 to the outside of the fuel tank 10. Yes. The description of the internal configuration of the tank cap 16 is omitted.

  FIG. 3 is a plan view (a) and a front view (b) of the mounting bracket. FIG. 4 is a cross-sectional view taken along the line AA in FIG. The mounting bracket 22 includes a fixing member 38 for fixing the mounting bracket 22 to the through hole 14 of the tank body 12 and a holding member 40 for mounting and holding the canister 20.

  The fixing member 38 is formed of an elastic flat plate material having a constant width h, and includes a base portion 41 formed in a substantially planar shape, and arc-shaped right wing portions 43 and left wing portions 45 formed at both ends thereof. Yes. Here, reference numeral 47 in FIG. 3 indicates a circle corresponding to the inner diameter with the upper portion 14 b of the through hole 14. As shown by the solid line in FIG. 3, the left and right wing parts 43, 45 are open at the tips beyond the circle 47, and the insertion into the through hole 14 is as shown by the dotted line. This is done by pressing the tip of the inside toward the inside. Therefore, when the fixing member 38 is fitted into the through hole 14 from above (shown by an arrow 100 in FIG. 1), the left and right wing parts 43 and 45 urge the mounting bracket 22 to the inner peripheral surface of the through hole 14. It acts to fix in the through hole 14. The length of the base portion 41 in the extending direction and the length of the arcs forming the left and right wing portions 43 and 45 can be determined as appropriate in consideration of the weight, size, etc. of the canister to be held.

  Further, the fixing member 38 is provided with a concave groove 52 extending in the extending direction of the base portion 41 and the left and right wing portions 43 and 45. The concave groove 52 stabilizes the urging force by the left and right wing portions 43 and 45, improves the durability of the fixing member 38, and withstands repeated insertion and removal of the mounting bracket 22. It should be noted that the depth, width, length and the like of the concave groove 52 can be appropriately determined in consideration of the material used for the fixing member 38 and the like.

  The holding member 40 has a flat plate shape, and has an engaging portion that engages with a component of the canister 20 and holds the canister 20. In the present embodiment, the engaging portion is constituted by the first claw portion 44, the second claw portion 46, the third claw portion 48, and the fourth claw portion 50 provided at the four corners of the holding member 40. The components of the canister 20 are engaged with these pawls, so that the canister 20 is securely held by the holding member 40.

  Here, the holding member 40 is fixed by welding or the like with the base portion 41 of the fixing member 38 having the same surface. In FIG. 3B, the fixed position is indicated by reference numeral 49. Note that the length of the holding member 40 is longer than the width h of the fixing member 38. Therefore, as shown in FIG. 3B, the first claw portion 44 and the second claw portion 46 are provided in a portion where the holding member 40 and the fixing member 38 overlap, and the third claw portion 48 and the fourth claw portion. 50 is fixed in such a manner as to protrude from the overlapping portion. Each pawl is formed with an inclination of about 45 degrees with respect to the plane of the holding member 40, but the angle is not particularly limited as long as the canister 20 is attached and held on the holding member 40.

  Further, at the upper center end of the fixing member 38, there is provided a protruding portion 42 for pulling out the canister that protrudes outward when the mounting bracket 22 is fitted into the through hole 14. The protrusion 42 is used to pull out the mounting bracket 22 fixed to the through hole 14 of the tank body 12. That is, it is possible to easily pull out the mounting bracket 22 to which the canister 20 is attached by holding the protrusion 42 with pliers or the like and pulling it upward. Alternatively, since a hole is formed in the projecting portion 42, the mounting bracket 22 may be pulled out by hooking a tool or the like into the hole.

  FIG. 5 is a front view when the canister 20 is held by the holding member 40 of the mounting bracket 22. The diameter of the fixing member 38 is larger than the outer diameter of the canister 20. Therefore, a certain gap is formed between the left and right wing portions 43 and 45 and the outer shape of the canister. In addition, an inlet chamber inlet 32 and a discharge chamber outlet 28 are formed in the upper portion of the canister 20 in a direction perpendicular to the insertion direction 100, and an air release hole 34 is provided in the lower portion of the canister 20, The exhaust chamber of the canister 20 is at atmospheric pressure.

  When the fixing member 38 is inserted into the through hole 14 after the canister 20 is attached to the holding portion 40 of the mounting bracket 22, the tips of both wing portions 43 and 45 formed in an arc shape are pressed with a tool or the like at the center of curvature. Then, it will be inserted into the through hole 14. When the mounting bracket 22 is inserted into the through hole 14, both the wing portions 43 and 45 of the fixing member 38 are urged against the inner wall surface of the through hole 14 by the elastic force that the fixing blade 38 has, and the mounting bracket 22 is firmly attached to the tank body 12. It will be fixed to. As described above, the fixing of the mounting bracket 22 to the through hole 14 is performed using an urging force, so that the fitting and removal of the mounting bracket 22 from the through hole 14 are easy.

  After the canister mounting bracket 22 is fitted into the through hole 14, the evaporative fuel outlet 27 at the top of the tank cap 16 and the introduction chamber inlet 32 of the canister 20 are connected by the first pipe 24. A second pipe 26 is connected to the discharge chamber outlet 28 of the canister 20 and is connected to an intake system connected to the engine body (not shown).

  Here, the first pipe 24 is not piped in the fuel tank 10 but is exposed and piped. Therefore, when the first pipe 24 is clogged or deteriorated due to secular change or the like, it can be easily removed and replaced with a new one. Further, as described above, the second pipe 26 is connected to the discharge chamber outlet 28 of the canister 20 and is piped to the intake system connected to the engine body, but can be piped through a gap between the canister 20 and the inner wall surface of the through hole 14. Therefore, the second pipe 26 does not need to bypass the tank main body 12 and can be routed to the intake system through the through hole 14 at the shortest distance. Thus, in the general-purpose engine of the present invention, the piping of the pipes around the canister 20 can be collected in a compact manner.

  In addition, after the canister 20 is attached to the through hole 14 with the mounting bracket 22, the lid 36 is covered on the upper part of the through hole 14, and the introduction chamber inlet 32, the discharge chamber outlet 28, the piping pipes 24, 26, etc. Is considered to protect. In addition, external impact is prevented from being applied to the canister 20 as much as possible. In FIG. 2, the lid 36 is omitted.

  The method of using the mounting bracket 22 according to the present invention is easy and simple. The new canister 20 is attached by first attaching and holding the new canister 20 to the holding member 40 of the mounting bracket 22. This attachment is performed by engaging the first to fourth claw portions 44, 46, 48, 50, which are the engaging portions of the holding member 40, and the constituent portions of the canister 20. After the canister 20 is attached to the holding member 40, the attachment fitting 22 is fitted into the through hole 14 while pressing the tips of the right wing 43 and the left wing 45 of the fixing member 38 toward the center of curvature. Thereafter, the first pipe 24 and the second pipe 26 are installed to complete the process. To replace the canister 20, first, the first pipe 24 and the second pipe 26 are removed from the canister 20, and the protrusion 42 of the mounting bracket 22 is gripped with pliers or the like. Then, the mounting bracket 22 is pulled out in the upper direction of the through hole 14 and taken out from the tank body 12. Thereafter, the old canister 20 is removed from the holding member 40 and a new canister is attached to the holding member 40. After that, it is as described above.

  Therefore, according to the general-purpose engine of the present embodiment, the canister is accommodated in a compact manner, and the pipe for guiding the evaporated fuel to the canister is exposed without passing through the inside of the fuel tank, so that maintenance is easy. The pipe connecting the intake system connected to the pipe can be routed in the shortest without detouring the fuel tank. The mounting bracket for mounting and fixing the canister has a simple configuration including a fixing member having elasticity and a holding member for holding the canister, and can be provided at low cost.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, the holding member of the mounting bracket is configured as a flat plate having four claw portions at four corners, but may be configured such that there is no claw portion and the canister is directly screwed to the holding member.

It is a schematic sectional drawing of the fuel tank of the general purpose engine of this invention. FIG. 2 is a schematic plan view of FIG. 1. It is the top view (a) and front view (b) of the mounting bracket of FIG. It is AA sectional drawing of FIG.3 (b). It is a front view at the time of attaching a canister to the attachment metal fitting shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fuel tank 12 Tank main-body part 14 Through-hole 20 Canister 22 Mounting bracket 24 1st pipe 26 2nd pipe (pipe)
38 Fixing member 40 Holding member 41 Base part 42 Protrusion part 43 Right wing part 45 Left wing part 52 Concave groove

Claims (5)

In a general-purpose engine having a fuel tank and an engine body,
A canister that adsorbs the evaporated fuel generated in the fuel tank is detachably disposed inside a through hole formed in the fuel tank.
A pipe for sucking evaporated fuel from the fuel tank, exposed from the fuel tank, and piped to the canister;
A general-purpose engine, wherein a pipe for purging evaporated fuel from the canister to an intake system of the engine body is provided through a gap between the canister and the through hole. The canister is detachably disposed in the through hole by a mounting bracket,
The mounting bracket includes a holding member for holding the canister, and a fixing member that exerts a biasing force on an inner wall surface of the through hole in a state of being fitted into the through hole. The general-purpose engine according to 1. The fixing member has a base portion to which the holding member is attached, and an arcuate wing portion extending from both ends of the base portion,
The general-purpose engine according to claim 2, wherein the holding member has an engaging portion that engages with a constituent portion of the canister to hold the canister.   The general-purpose engine according to claim 2, wherein the fixing member is provided with a concave groove extending in an extending direction of the base part and the wing part.   5. The canister pulling-out projecting portion that protrudes outward from the through hole in a state in which the canister is loaded in the through hole is provided on the fixing member. A general-purpose engine according to claim 1.

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