JPH0141889Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention combines a carburetor body with a throttle valve guide tube upright on the upper surface to the end of an intake pipe that is connected and fixed to the engine body, thereby creating a sliding throttle valve type. The present invention relates to a carburetor mounting structure in which the carburetor is mounted to an engine body.

Conventionally, in such a mounting structure, for example, the carburetor is provided with a fitting cylinder part that communicates with the downstream end of the intake passage, and the fitting cylinder part is enlarged in the radial direction by providing a slit extending in the axial direction. After the end of the intake pipe is fitted into the fitting cylinder part, the fitting cylinder part is tightened so that the width of the slit becomes small, and the carburetor and the intake pipe are connected. For this reason, depending on the degree of tightening, the carburetor may be angularly displaced around the axis of its intake passage or may move along the axis of the intake passage, making it impossible to securely connect the carburetor.

The present invention has been made in order to eliminate these conventional drawbacks, and allows a sliding throttle valve type carburetor to be easily and reliably connected to an intake pipe, and in addition, a part of the connecting means is used to connect the carburetor to the intake pipe. It is an object of the present invention to provide a structure for mounting a carburetor on an engine body, which is arranged in a dead space above the carburetor body and on the side of a throttle valve guide cylinder and can effectively utilize the space.

In order to achieve the above object, according to the present invention, a fitting hole is formed in the carburetor main body of the carburetor, and the fitting hole is concentrically connected to the downstream end of the intake passage, and the fitting hole is fitted through the annular sealing member. A fitting cylinder portion is provided at the end of the intake pipe, and the carburetor main body and the intake pipe are
They are interconnected by means capable of preventing rotation of the carburetor about the axis of the intake duct and movement of the carburetor in the axial direction, the means being mounted on the upper surface of the carburetor body on one side of the throttle valve guide tube. a connecting portion that projects integrally; a first contact surface provided on the carburetor body facing downstream of the intake pipe; and a first contact surface of the intake pipe that contacts the connecting portion on one circumferential side. a support portion integrally provided at the end; a second contact surface provided at the end of the intake pipe to abut the first contact surface;
substantially perpendicular to the axis for tightening the connecting part and the supporting part in a direction in which the first and second contact surfaces are brought into contact with each other and the fitting cylinder part is fitted into the fitting hole; and a screw member extending in the direction.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, in FIG. 1 showing an embodiment of the present invention, a two-cycle engine body 1 has one end of an intake pipe 2 that communicates with the crank chamber. Linking,
A sliding throttle valve type carburetor C is connected to the other end of the intake pipe 2 by a mounting structure according to the present invention. As a result, the carburetor C is attached to the engine body 1, and the inlet of the carburetor C is connected to the rubber tube 4.
It is connected to an air cleaner (not shown) via.

Referring to FIGS. 2 and 3 together, one end of the intake pipe 2 is provided with a flange 5 for attachment to the engine body 1, and the intake pipe 2 connects the flange 5 to the engine body 1. In this state, it extends upward from the mounting position, and is further bent toward the upper side of the engine body 1 at its upper end. Since the carburetor C is coupled to the other end of the bent intake pipe 2, the carburetor C is attached to the engine body 1 at a position above the engine body 1.

Further, referring also to FIG. 4, a throttle valve guide cylinder 3a is integrally installed in the center of the upper surface of the carburetor main body 3 of the carburetor C, and a sliding throttle valve (not shown) is installed in this guide cylinder 3a. is slidably housed and held. Further, a fitting hole 7 is bored in the side of the carburetor main body 3, and the fitting hole 7 concentrically communicates with the downstream end of the intake passage 6. A first abutment surface 9 is provided. Further, a connecting portion 10 is integrally provided on the upper surface of the carburetor main body 3a on the side of the throttle valve guide cylinder 3a and above the fitting hole 7. A screw hole 11 extending in the direction is bored.

On the other hand, a fitting cylindrical portion 13 is integrally provided at the other end of the intake pipe 2 with a stepped second contact surface 12 interposed therebetween. The fitting cylinder part 13 is formed to have an outer diameter that can be fitted into the fitting hole 7.
On the outer periphery of 3, an O-ring 14 is provided as a sealing member to perform a sealing action between the inner surface of the fitting hole 7 and the inner surface of the fitting hole 7.
is fitted. Further, the second contact surface 12 is connected to the fitting cylinder portion 1.
It is formed into a planar shape perpendicular to the axis of the 3. Furthermore, a supporting part 15 is integrally provided at the other end of the intake pipe 2, and this supporting part 15 fits the fitting cylinder part 13 into the fitting hole 7, and the first and second abutting surfaces. 9,1
2, the connecting portion 10 of the carburetor main body 3
The screw member 16 is disposed at a position where it abuts on one circumferential side of the screw member 16 to be screwed into the screw hole 11.
An insertion hole 17 is formed in the support portion 15 for inserting the.

Next, the operation of this embodiment will be explained. When attaching the carburetor main body 3 to the engine main body 1, first the intake pipe 2 is fixed to the engine main body 1 by the flange 5 at one end thereof. Next, the fitting cylinder part 13 at the other end of the intake pipe 2 is fitted into the fitting hole 7 of the carburetor main body 3, and the carburetor main body 3 is inserted until the first and second contact surfaces 9, 12 are in contact with each other. Press it toward the intake pipe 2 side. In this state, the connecting part 10 and the supporting part 15 are placed adjacent to each other so that the screw hole 11 and the insertion hole 17 are located concentrically, and the screw member 16 is inserted from the insertion hole 17 side and screwed into the screw hole 11. and tighten. Thereby, the carburetor main body 3 and the intake pipe 2 are connected to each other.

In this connected state, the inner surface of the fitting hole 7 and the fitting cylinder part 1
An O-ring 14 is interposed between the outer surface of the carburetor body 3 and the intake pipe 2, thereby providing an airtight connection between the carburetor body 3 and the intake pipe 2. Moreover, the support part 15 and the connection part 10
A screw member 16 perpendicular to the intake direction 8 of the intake passage 6
Since the carburetor main body 3 is connected to each other at this point, rotational movement of the carburetor main body 3 around the axis of the fitting cylinder portion 13, that is, the intake passage 6 is prevented. Further, due to its own weight, a force acts on the carburetor main body 3 to rotate it in the counterclockwise direction in FIG. Therefore, the rotational movement of the carburetor main body 3, that is, the movement movement along the axis of the intake passage 6 is prevented. Furthermore, when inserting and removing the fitting tube portion 13 into the fitting hole 7, the O-ring 1
4 and the inner surface of the insertion hole 7 can be applied with enough pressure or tension to overcome the frictional force between the insertion hole 7 and the inner surface of the insertion hole 7, so that the insertion and removal work is easy.

FIG. 5 shows another embodiment of the present invention, in which a stepped first contact surface 9' facing downstream along the intake direction 8 is provided between the insertion hole 7 and the intake passage 6. A second contact surface 12' that can contact the first contact surface 9' is provided at the tip of the fitting cylinder portion 13. The other configurations are the same as those of the embodiment described above, and this embodiment can also achieve the same effects as the embodiment described above.

As described above, according to the present invention, a carburetor main body having a throttle valve guide tube erected on the upper surface is connected to the end of an intake pipe connected and fixed to the engine body, and a sliding throttle valve type carburetor is produced. In the mounting structure in which the carburetor is attached to the engine body, a fitting hole is formed in the carburetor body of the carburetor and is concentrically connected to the downstream end of the intake passage, and the carburetor is fitted into the fitting hole through an annular sealing member. a fitting cylinder portion provided at an end of the intake pipe,
the carburetor body and the intake pipe are interconnected by means capable of preventing rotation of the carburetor about the axis of the intake passage and movement of the carburetor in the axial direction;
The means includes a connecting portion integrally protruding from the upper surface of the carburetor main body on one side of the throttle valve guide tube, and a first contact surface provided on the carburetor main body facing the downstream side of the intake passage. a support part integrally provided at the end of the intake pipe to abut on the connecting part on one side in the circumferential direction; and a support part provided at the end of the intake pipe to abut on the first contact surface. 2 abutting surfaces, and the first and second abutting surfaces are brought into contact with each other, and the fitting cylinder portion is fitted into the fitting hole, and the connecting portion and the supporting portion are tightened in a direction in which they approach each other; and a screw member extending in a direction substantially perpendicular to the axis, the vaporization is caused by the mutual contact between the first and second contact surfaces and the fastening between the connecting portion and the supporting portion by the screw member. Both relative rotation and relative movement in the axial direction between the carburetor body and the intake pipe can be reliably prevented, and the carburetor body can be integrally and firmly connected and fixed to the intake pipe. Furthermore, in the above-mentioned connection and fixation, the tightening force by the screw member is reliably received by the mutual engagement of the connection part and the support part, and the annular seal member between the fitting hole and the fitting cylindrical part does not act, there is no risk that the sealing member will be unevenly deformed by the tightening force, and furthermore, after the connection and fixation, relative movement between the fitting hole and the fitting cylinder portion is reliably regulated. Therefore, the sealing member interposed therebetween remains stationary without sliding relative to other objects, and as a result, the sealing member can always perform an accurate sealing function. Further, since the support portion and the connecting portion are provided integrally with the intake pipe and the carburetor body, the only connecting part between the intake pipe and the carburetor body is a screw member, which can contribute to a reduction in the number of parts. Furthermore, since the screw member extends in a direction substantially perpendicular to the intake passage axis, the screw tightening work can be easily performed from the outside of the carburetor body without being obstructed by the throttle valve guide cylinder or the intake pipe. , it can contribute to improving the work efficiency. Furthermore, since the above-mentioned connecting portion, which is integrally provided in the carburetor body, protrudes from the top surface of the carburetor body on one side of the throttle valve guide cylinder, it should essentially become a dead space on the side of the throttle valve guide cylinder and above the carburetor body. The space can be effectively used as an installation space for the connecting portion and the distal end of the supporting portion connected thereto.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a side view showing the state of connection between the carburetor and the intake pipe, FIG. 2 is an enlarged view taken in the direction of the arrow in FIG. 1, and FIG. 3 is an enlarged view of FIG. 1 in the direction of the arrows, FIG. 4 is an enlarged vertical sectional view of the portion shown in FIG. 1, and FIG. 5 is an enlarged longitudinal sectional view of another embodiment of the present invention corresponding to FIG. 4. be. C... Carburetor, 1... Engine body, 2... Intake pipe, 3... Carburetor body, 3a... Throttle valve guide tube,
6...Intake path, 7...Inset hole, 8...Intake direction,
9, 9'...first contact surface, 10...connecting portion, 12,
12'... Second contact surface, 13... Fitting cylinder part, 14
. . . O-ring as a sealing member, 15 . . . Support portion, 16 . . . Screw member.

Claims (1)

[Scope of utility model registration request] A carburetor body 3 with a throttle valve guide tube 3a erected on the upper surface is connected to the end of an intake pipe 2 that is connected and fixed to the engine body 1, and a sliding throttle valve type carburetor is attached to the engine body. In such a mounting structure,
The carburetor main body 3 of the carburetor C is provided with a fitting hole 7 concentrically communicating with the downstream end of the intake passage 6, and a fitting cylinder portion 13 is fitted into the fitting hole 7 via an annular sealing member 14. is provided at the end of the intake pipe 2,
The carburetor body 3 and the intake pipe 2 are connected to each other by means capable of preventing rotation of the carburetor C around the axis of the intake passage 6 and movement of the carburetor C in the axial direction, and the means include the restrictor. A connecting portion 10 integrally protrudes from the upper surface of the carburetor main body 3 on one side of the valve guide cylinder 3a, and a first contact surface 9 provided on the carburetor main body 3 facing the downstream side of the intake passage 6. ,9'
a supporting portion 15 that is integrally provided at the end of the intake pipe 2 so as to abut the connecting portion 10 on one side in the circumferential direction; a second contact surface 12, 12' provided at the end of the second contact surface;
The first and second contact surfaces 9, 9', 12, 12' are brought into contact with each other, and the fitting cylinder part 13 is inserted into the fitting hole 7.
The connecting portion 10 and the supporting portion 1 are inserted into the
and a screw member 16 extending in a direction substantially perpendicular to the axis for tightening the carburetor 5 in a direction close to each other.