JP4991628B2 - Carburetor - Google Patents

Description

  The present invention relates to an improvement of a carburetor.

A conventional carburetor is known in which a main nozzle that discharges fuel is provided in a main air passage in which a choke valve and a throttle valve are arranged (see, for example, Patent Document 1).
Japanese Utility Model Publication 1-337163

  According to FIG. 2 of Patent Document 1, an air-fuel mixture passage 1 as a main air passage is provided in a carburetor, and a choke valve 2 on the upstream side of the air-fuel mixture passage 1 and a throttle valve 4 on the downstream side can be freely opened and closed. The venturi 3 is formed in the air-fuel mixture passage 1 between the choke valve 2 and the throttle valve 4, and the main nozzle 9 is attached so as to protrude from the venturi 3.

  Below the main nozzle 9, there is provided a main jet 8 for adjusting the fuel flow rate when the fuel stored in the float chamber 5 is supplied to the main nozzle 9, and between the main jet 8 and the main nozzle 9. A plurality of small holes that promote the atomization of the fuel by mixing the air introduced from the air-fuel mixture passage 1 with the fuel are formed in the wall of the pipe line.

  For example, when the engine is tilted during engine operation and the carburetor is tilted accordingly, the fuel flow path from the main jet 8 to the main nozzle 9 is tilted, so that the fuel is mixed from the main nozzle 9 in a liquid state. It may flow out into the air passage 1. In such a case, it becomes difficult for the fuel to atomize, it becomes difficult to form a uniform air-fuel mixture, combustion in the engine becomes unstable, and engine output decreases.

Even when the carburetor is tilted in this way, if the fuel and air are well mixed, the atomization of the fuel is promoted and the combustion of the engine is stabilized.
An object of the present invention is to provide a carburetor that improves the mixing of fuel and air.

According to the first aspect of the present invention, a lower through hole penetrating from the outer peripheral surface to the inner peripheral surface is provided in the lower portion of the nozzle arranged vertically, and the upper portion of the lower through hole of the nozzle penetrates from the outer peripheral surface to the inner peripheral surface In a carburetor that has a large number of inflow holes that allow air to flow into the fuel that flows upward in the nozzle through the lower through holes and the inflow holes, the lower through holes and the inflow holes are covered with a reticulated material. A collar lower through-hole that directly connects to the lower through-hole is provided, and a part of the air supplied from the collar lower through-hole is mixed with fuel through the lower through-hole, and the remainder of the air nozzles in the mesh material After being divided in the axial direction, the fuel is mixed with the fuel through the inlet .

Air flows into the vertical passage in the nozzle from the lower through hole of the nozzle through the collar lower through hole of the mesh-like material, and the air mixes with the rising fuel and rises with the fuel as many bubbles. When passing through the reticulated material through the collar lower through hole, the air flow is subdivided into turbulent flow, which flows in the axial direction of the nozzle and is subdivided into a plurality of inflows. It flows into the nozzle from the hole.
Therefore, the air that has passed through the mesh material is subdivided into many air flows, and each air flow becomes turbulent and becomes easy to mix with the fuel. As compared with a case where air simply passes through the inflow hole, atomization of the fuel is further promoted.

  Therefore, even if the carburetor is tilted together with the engine during operation of the engine and liquid fuel flows out from the nozzle to the main air passage, atomization is promoted and a desired mixing ratio of fuel and air is easily obtained. The combustion of is stabilized.

In the invention which concerns on Claim 1, the lower through-hole penetrated from the outer peripheral surface to an inner peripheral surface is provided in the lower part of the nozzle arrange | positioned vertically, and it penetrates from the outer peripheral surface to an inner peripheral surface in the site | part of the upper lower through-hole of a nozzle. In a carburetor that has a large number of inflow holes that allow air to flow into the fuel that flows upward in the nozzle through the lower through holes and the inflow holes, the lower through holes and the inflow holes are covered with a reticulated material. A collar lower through-hole that directly connects to the lower through-hole is provided, and a part of the air supplied from the collar lower through-hole is mixed with fuel through the lower through-hole, and the remainder of the air nozzles in the mesh material After being subdivided by flowing in the axial direction of the fuel, it is mixed with the fuel via the inlet, so that the air flow is refined and turbulent by the mesh material, making it easy to mix the fuel and air be able to

In particular, in the present invention, air flows from the lower through-hole of the nozzle through the collar lower through-hole of the mesh material into the vertical passage in the nozzle, and the air mixes with the rising fuel and becomes a large number of bubbles to form the fuel. After rising through the collar lower through-hole and passing through the mesh material, it is subdivided into an air flow, and the air flow becomes turbulent and flows in the axial direction of the nozzle and is subdivided. It flows into the nozzle from a large number of inflow holes.
Therefore, for example, even when the engine is tilted and liquid fuel flows out of the carburetor nozzle, fuel atomization can be further promoted, and an appropriate mixing ratio of fuel and air can be easily obtained. Can stabilize the combustion. As a result, it is possible to prevent a decrease in engine output at a high engine speed or during acceleration.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a front view of an engine equipped with a carburetor according to the present invention. An engine 10 has a cylinder head 12 attached to an end of a cylinder block 11, and a carburetor 13 connected to the front surface of the cylinder head 12. An air cleaner 16 is connected to the front mounting surface 14a of the carburetor body 14 constituting the carburetor 13 via an intake pipe 15, and is mounted on, for example, a boat that moves in rivers, lakes, swamps, the sea, and the like. Reference numeral 18 denotes a fuel tank that supplies fuel to the carburetor 13.

  FIG. 2 is a plan view of the carburetor according to the present invention. The carburetor 13 has a fuel cock 25 on its upper surface, a choke lever 27 attached to the upper end of a choke valve shaft 26 that supports the choke valve, and a throttle valve. And a throttle lever 29 attached to the upper end of the throttle shaft 28.

  The choke lever 27 is disposed in the vicinity of the front mounting surface 14a of the carburetor body 14, and the throttle lever 29 is provided on the rear mounting surface 14b of the carburetor body 14 on which the carburetor 13 is mounted on the cylinder head 12 (see FIG. 1). It is arranged in the vicinity.

  3 is a cross-sectional view taken along line 3-3 of FIG. 2, and the carburetor body 14 forms an float body 32 and an upper body 31 provided with a main air passage 31a through which air and fuel flow from the air cleaner side to the engine side. Therefore, the lower body 33 is attached to the lower portion of the upper body 31. Reference numerals 34 and 36 are floats of an integral structure attached to the upper body 31 so as to be swingable up and down, and 37 is an O-ring provided between the upper body 31 and the lower body 33.

  The upper body 31 has a main air passage 31a, a cylindrical portion 31b that is located below the main air passage 31a and projects downward, an upper end communicating with the main air passage 31a, and a lower end that is a cylindrical portion 31b. A vertical hole portion 31c opened in the cylindrical portion 31b so as to open at the lower end of the tube, a first inclined passage 31d and a horizontal passage 31e communicating with the vertical hole portion 31c, and a second inclined passage communicating with the horizontal passage 31e. A passage 31f and an upper vertical hole portion 31g formed at the upper end of the second inclined passage 31f are provided.

  The vertical hole portion 31c is formed with an upper hole 31j, an upper female screw 31k, and a lower female screw 31m in order from the top, and a vertical hole portion 31c and a cylindrical hole 31b between the upper female screw 31k and the lower female screw 31m. Through holes 31n and 31n for communicating with the float chamber 32 are formed.

The upper hole 31j is a portion into which the nozzle assembly 38 provided with the main nozzle is inserted.
The upper female screw 31k is a portion into which the main jet 41 in which the orifice 41a for regulating the fuel flow rate to a predetermined amount is formed, and the main jet 41 is also a component for fixing the nozzle assembly 36 in the upper hole 31j. .
The lower female screw 31m is a portion into which a bolt 42 for fixing the lower body 33 to the upper body 31 is screwed. Reference numeral 43 denotes a seal member.

The first inclined passage 31d is closed by a ball 45 being press-fitted at the end thereof, and an opening 31p of an air passage (not shown) communicating with the main air passage 31a is provided in the middle.
The lateral passage 31e is a portion whose end is blocked by a ball 46.

  The upper vertical hole portion 31g is a portion to which a lid member 47 formed with an orifice 47a for restricting the air flow rate to a predetermined amount is attached. The lid member 47 is connected to the main air passage 31a via an air passage (not shown). The relay hole 47b communicates with the second inclined passage 31f via the orifice 47a.

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 1, and the main air passage 31a has a venturi portion 31r with a small inner diameter formed at the center in the longitudinal direction, and the air flow in the venturi portion 31r A choke valve 51 for thickening the air-fuel mixture by closing the main air passage 31a when the engine is started is provided on the upstream side so as to be openable and closable, and the main air passage 31a is provided downstream of the air flow in the venturi portion 31r. A throttle valve 52 for adjusting the flow rate of flowing air is provided so as to be freely opened and closed.
The front end portion of the main nozzle 54 constituting the nozzle assembly 38 (see FIG. 3) faces the venturi portion 31r.

  The choke valve 51 is attached to a choke valve shaft 26 that is rotatably attached to the upper body 31, and the throttle valve 52 is attached to a throttle shaft 28 that is rotatably attached to the upper body 31.

Reference numeral 31s in the drawing is another opening portion of the air passage communicating with the opening portion 31p (see FIG. 3), and communicates with the main air passage 31a via the air passage 31t.
Reference numeral 31u is an opening portion of an air passage communicating with the relay hole 47b (see FIG. 3), and communicates with the main air passage 31a via the air passages 31v and 31w.

  FIG. 5 is a sectional view showing a nozzle assembly according to the present invention. The nozzle assembly 38 includes a main nozzle 54 and a nozzle tube body 57 including an air bleed pipe 56 integrally formed with the main nozzle 54. It consists of a cylindrical mesh collar 58 that covers the outer peripheral surface 56a of the air bleed pipe 56 of the tubular body 57.

  The nozzle tube 57 has a longitudinal passage 57a extending in the longitudinal direction. The air bleed tube 56 has a plurality of air bleed holes 56c and lower through holes 56d and 56d so as to penetrate the longitudinal passage 57a and the outer peripheral surface 56a. Opened. Reference numeral 57 c denotes an annular flange portion formed on the nozzle tube body 57 in order to restrict the upward movement of the mesh collar 58.

The mesh collar 58 is a nylon material in which an infinite number of watermarks such as meshes are formed. In FIG. 3 and FIG. 5, the main collar 31a and the first inclined passage 31d and the lateral passage 31e are used. When the supplied air passes through the watermarks, it is subdivided into many air flows and the air flow is turbulent and mixed with the fuel. As a result, the air becomes fine bubbles in the fuel. When the fuel is sucked out from the main nozzle 54 into the main air passage 31a, atomization of the fuel is promoted.
The shape of the watermark of the mesh color 58 is, for example, a rectangle, and the size thereof is 0.1 mm in length and width.

  The reference numeral 58a in the figure is attached to the outer peripheral surface of the mesh collar 58 shown in FIG. 5 in order to fit into the annular recess provided in the upper hole 31j of the upper body 31 shown in FIG. The formed annular convex portion 58b having flexibility is a collar formed under the mesh collar 58 so as to communicate with the lower through holes 56d and 56d of the nozzle tube body 57 and the lateral passage 31e (see FIG. 3). It is a lower through hole.

Next, the operation of the carburetor 13 described above will be described.
FIG. 6 is an operation diagram showing the operation of the carburetor according to the present invention.
3, when air is supplied into the air bleed pipe 56 from the main air passage 31a through the first inclined passage 31d, the second inclined passage 31f, and the lateral passage 31e, the case of the lateral passage 31e in FIG. As shown by the arrow A, air flows from the lateral passage 31e through the collar lower through hole 58b and the lower through hole 56d into the vertical passage 57a, and the air is whitened in the vertical passage 57a. As indicated by the arrow, the fuel 61 is mixed with the rising fuel 61 and becomes a large number of bubbles 62 and rises together with the fuel 61.

  Further, as indicated by an arrow B, air enters the space 65 between the tubular portion 31 b and the air bleed pipe 56 from the lateral passage 31 e through the collar lower through hole 58 b, and a plurality of air flows along the mesh collar 58. As shown by the arrow, it rises.

  That is, in the space 65, when the air passes through a plurality of fine mesh holes 71 formed in the mesh collar 58, it is subdivided into many air flows, and the air flows become turbulent. Then, when these air flows flow into the longitudinal passage 57a through the air bleed hole 56c, they are mixed with the fuel 61 as fine countless bubbles 66.

  Therefore, when the fuel 61 is sucked into the main air passage 31a from the upper end of the main nozzle 54 shown in FIG. 3, atomization of the fuel 61 is promoted, and a uniform air-fuel mixture is formed and supplied into the combustion chamber of the engine. Therefore, combustion is stabilized.

  1 and 3, for example, when a boat equipped with the engine 10 moves forward, the carburetor 13 is tilted together with the engine 10, and liquid fuel enters the main air passage 31 a from the main nozzle 54. Even if it flows out, the atomization of the fuel is promoted and the combustion is stabilized, so that the engine output is unlikely to decrease even when the boat is accelerated or in the high rotation region of the engine 10.

  As shown in FIGS. 3, 5, and 6, the air bleed hole 56 c as an inflow hole through which air flows into the main nozzle 54 is provided as a nozzle, and the fuel 61 and air are mixed in the main nozzle 54. In the carburetor 13, the periphery of the plurality of air bleed holes 56c is covered with a mesh collar 58 as a mesh material, so that an air flow that is subdivided into a large amount is formed by the mesh collar 58 and the air flow is turbulent. Thus, the fuel 61 and the air can be easily mixed.

  Therefore, for example, even when the engine 10 (see FIG. 1) tilts and the liquid fuel 61 flows out from the main nozzle 54 of the carburetor 13, atomization of the fuel 61 can be further promoted, and the fuel 61 and the air An appropriate mixing ratio is easily obtained, and combustion in the engine 10 can be stabilized. As a result, it is possible to prevent a decrease in engine output at a high speed range of the engine 10 or at the time of boat acceleration.

  In the embodiment, as shown in FIG. 6, the plurality of mesh holes 71 of the mesh collar 58 are provided so as to overlap in the radial direction. However, the present invention is not limited thereto, and the outer peripheral surface and the inner peripheral surface are formed on a cylindrical member. By forming a mesh collar by providing a plurality of mesh holes penetrating the mesh holes, the mesh holes are provided so that they do not overlap in the radial direction, and air is passed through the mesh holes from the outer peripheral surface side to the inner peripheral surface side of the mesh collar. You may make it flow.

  The carburetor of the present invention is suitable for a boat engine.

It is a front view of an engine provided with a carburetor according to the present invention. It is a top view of the carburetor concerning the present invention. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. FIG. 4 is a sectional view taken along line 4-4 of FIG. It is sectional drawing which shows the nozzle assembly which concerns on this invention. It is an operation view showing an operation of the carburetor according to the present invention.

Explanation of symbols

13 ... Carburetor, 54 ... Nozzle (main nozzle), 56c ... Inflow hole (air bleed hole), 56d ... Lower through hole, 58 ... Reticulated material (mesh color), 58b ... Color lower through hole .

Claims (1)

A lower through hole (56d) penetrating from the outer peripheral surface to the inner peripheral surface is provided at a lower portion of the vertically arranged nozzle (54), and an outer peripheral surface is provided at a position above the lower through hole (56d) of the nozzle (54). A plurality of inflow holes (56c) penetrating from the nozzle to the inner peripheral surface are provided, and air flows into the fuel flowing upward in the nozzle (54) through the lower through hole (56d) and the inflow hole (56c). In the carburetor (13),
Covering the lower through hole (56d) and the inflow hole (56c) with a mesh material (58);
A collar lower through hole (58b) directly connected to the lower through hole (56d) is provided in the mesh material (58),
A part of the air supplied from the collar lower through hole (58b) is mixed with the fuel through the lower through hole (56d),
The remainder of the air flows in the mesh material (58) in the axial direction of the nozzle (54) and is subdivided and then mixed with the fuel via the inlet (56c).
A carburetor characterized by that.

Images