JPS6217659B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a constant vacuum carburetor equipped with a negative pressure operated valve that moves up and down in the intake passage by the negative pressure generated in the intake passage upstream of the throttle valve, and particularly relates to a constant vacuum carburetor. A negative pressure operating valve is formed by a ventilee forming part and a plate-shaped guide part protruding from a side surface along the longitudinal axis of the ventilizing part, and the negative pressure operating valve is slidably guided to the carburetor main body. The present invention relates to a method for manufacturing a constant vacuum vaporizer.

Generally, in order to guide and hold the negative pressure operated valve of a constant vacuum type vaporizer in a slidable manner in the vaporizer main body, a guide groove is bored from the atmospheric chamber opening on the side of the vaporizer main body, and a guide groove is drilled into the guide groove. This is a device in which a negative pressure operated valve is arranged, and since the guide groove of the generally used cylindrical negative pressure operated valve is also cylindrical, it can be easily manufactured by drilling. . However, the present applicant has proposed a constant vacuum type carburetor with good air-fuel mixture controllability and excellent suction efficiency, that is, a negative pressure operated valve with a plate-shaped guide part protruding from the side of the ventilate forming part. In the case where the guide part is slidably arranged in the ventilate forming part guide hole bored in the carburetor body and in the plate-shaped guide groove, a part of the guide groove in the carburetor body is plate-shaped. Since drilling cannot be used to process the plate-shaped guide grooves, the process is difficult and expensive.

The present invention has been made in view of the above-mentioned disadvantages, and has been developed to improve the negative pressure operated valve of a constant vacuum type vaporizer, which has a negative pressure operated valve provided with a plate-shaped guide part protruding from the side of the ventilium forming part. The present invention relates to a method for manufacturing a constant vacuum type vaporizer that can be simply and reliably slidably guided and held in the vaporizer main body.

Hereinafter, one embodiment of the method for manufacturing a constant vacuum type vaporizer according to the present invention will be described with reference to the drawings. Figures 1 and 2
Figures 1 and 3 show the material of the carburetor main body. Figure 1 is a longitudinal cross-sectional view, Figure 2 is a top plan view of Figure 1, and Figure 3 is a longitudinal cross-section along the line shown in Figure 1. It is a diagram.

Reference numeral 1 denotes a carburetor body through which an intake passage 2 passes, an atmospheric chamber recess 3 on one side of the intake passage 2, and a main fuel boss 4 and a float chamber recess 5 on the other side of the intake passage 2. , a guide groove 6 is bored from the upper opening of the atmospheric chamber recess 3 .

This guide groove 6 is formed on one side 17 of a ventilee forming portion 17A formed in a negative pressure operating valve 17, which will be described later.
A', a semicircular first ventilary forming part guide surface 6A for slidingly holding one side 17B' of the plate-shaped guide part 17B, and both sides from the end of the first ventilly forming part guide surface 6A. It is formed by an extending first plate-shaped guide portion guide surface 6B and a guide member guide groove 6C for arranging a guide member 7, which will be described later.

The guide member guide groove 6C has a substantially rectangular cross section, and the first plate-shaped guide portion guide surface 6
The guide surface 6</b>A of the first ventilary forming portion extends to approximately the bottom of the intake passage 2 together with the intake passage B, and the first ventilary forming portion guide surface 6</b>A penetrates into the intake passage 2 . That is, the shapes of the first ventilary forming part guide surface 6A and the first plate-shaped guide part guide surface 6B are similar to one side 17A' of the ventilary forming part 17A of the negative pressure operating valve 17 and one side of the plate-shaped guide part 17B. 17
B′ is matched.

Next, the guide member 7 disposed in the guide groove 6 will be explained with reference to FIGS. 4, 5, and 6. Figure 4 is a side view, Figure 5 is a top plan view,
FIG. 6 is a right side view.

The guide member 7 has a substantially rectangular cross-section having the same shape as the guide member guide groove 6C formed in the carburetor body 1 so as to be fitted into the guide groove 6 of the carburetor body 1, and is a negative pressure operated valve. L for guiding and holding the other side 17B'' of the plate-shaped guide portion 17B of 17
The second plate-shaped guide portion guide surface 7A of the mold and the other side 17 of the ventilary forming portion 17A of the negative pressure operating valve 17
A semicircular second ventilary forming part guide surface 7B capable of slidingly guiding and holding A' is bored on one surface of the guide surface 7B, and a hole 7C that matches the intake passage 2 of the carburetor main body 1 is formed in a second plate shape. The guide portion guide surface 7A, the second ventilly forming portion guide surface 7
It is drilled perpendicular to B.

In order to slidingly guide and hold the negative pressure operated valve 17 in the carburetor main body 1 and the guide member 7 formed as described above, the guide surface 6A and the first ventilary forming part guide surface 6A of the carburetor main body 1 as shown in FIG. 1. The second ventilary forming portion guide surface 7B of the guide member 7 and the second plate-shaped guide portion guide surface 7A are arranged opposite to the plate-shaped guide portion guide surface 6B, and the guide groove 6
The guide member 7 is inserted therein.

According to this, the semicircular first part of the carburetor main body 1
Bentuary forming part guide surface 6A and guide member 7
A cylindrical ventilate forming part guide hole 8A that slides and holds the ventilary forming part 17A of the negative pressure operating valve 17 is formed by the semicircular second ventilee forming part guide surface 7B, while the carburetor main body The plate-shaped guide part 17B of the negative pressure operated valve 17 is slidably guided and held by the first plate-shaped guide part guide surface 6B of the guide member 7 and the L-shaped second plate-shaped guide surface 7A of the guide member 7. A plate-shaped guide groove guide hole 8B is formed, and the intake passage 2 passes through the carburetor main body 1 through the hole 7C of the guide member 7.

In order to accurately form the hole width S of the plate-shaped guide groove 8B, one side of the guide member guide groove 6B facing the air cleaner, that is, the first ventilary forming part guide surface 6A and the first plate-shaped guide part The plane of the guide surface 6B is the longitudinal axis of the intake passage 2
It is formed by casting along the axis Y-Y in the direction perpendicular to -X, and specifically, the atmospheric chamber recess 3,
By tilting the upper core of the mold including the guide groove 6 by α degree with respect to the axis Y-Y, the mold is cast diagonally upward, and the first ventilate forming part guide surface 6a and the first plate-shaped guide part are formed. The guide surface 6B can be formed by casting perpendicularly along the axis Y-Y. On the other hand, in the guide member 7, a mold including an L-shaped second plate-shaped guide part guide surface 7A and a second ventilate forming part guide surface 7B, and a mold including other external shapes of the guide member 7 are used as guide members. A second plate-shaped guide portion guide surface 7A, which is cast out laterally by matching with the outer corner portion A of 7 (see FIG. 5),
The plane of the guide surface 7B of the second ventilium forming part can be precisely cast and formed perpendicular to the hole 7C (perpendicular to the intake passage 2). Therefore, by fitting and arranging the guide member 7 into the guide groove 6 of the carburetor main body 1 as described above, it is possible to form the ventilate forming portion guide hole 8A accurately and orthogonally to the intake passage 2 without any machining. A plate-shaped guide groove 8B is formed, and in particular, it is easy to manufacture a constant vacuum type vaporizer having a plate-shaped guide portion, and the manufacturing cost ratio to the product can be greatly reduced.

In order to accurately match the ventilary forming part guide hole 8A with the ventilary forming part 17A of the negative pressure operating valve 17, and to make the hole 7C of the guide member 7 exactly match the intake path 2 of the carburetor main body 1, a guide is used. After the member 7 is fitted into the carburetor main body 1, it may be processed again, and in this case, the manufacturing is extremely easy, especially since the processing can be performed by drilling.

Then, the material of the vaporizer main body 1 thus formed is further processed at desired locations, and then as shown in FIG.
The product is made by incorporating various parts as shown in FIG.

That is, an intake passage 2 passes through the carburetor body 1, and a throttle valve 10 is rotatably disposed on the engine side of the carburetor body 1 on a throttle valve shaft 11. The carburetor main body 1 is provided with a bypass hole 12 and a pilot outlet hole 13 that are connected to each other, and a float chamber 15 is formed by a float main body 14 disposed corresponding to one side of the carburetor main body 1. A float 16, a valve seat disposed in a fuel inflow path (not shown), and a float valve are arranged in the float chamber 15, and a constant liquid level T-T is always formed by the cooperation of these elements.

Reference numeral 17 denotes a negative pressure operated valve that is slidably guided and held in the carburetor main body 1 and moves up and down within the intake passage 2. Bench lily forming part 1
7A and a plate-shaped guide portion 17B provided to protrude laterally from the side surface along the longitudinal axis direction Y-Y of the ventilee forming portion 17A.

As described above, in this negative pressure operated valve 17, the ventilate forming part 17A is slidably guided and held by the ventilary forming part guide hole 8A of the carburetor main body 1, and the plate-shaped guide groove 8B holds the ventilary forming part 17A. The guide portion 17B is slidably guided and held.

Further, a partitioning body 18 such as a diaphragm or a cylinder is integrally arranged above the negative pressure operating valve 17, and an atmospheric chamber 19A is formed by this partitioning body 18 and the upper recess of the carburetor main body 1. A pressure receiving chamber 19B is formed by the body 18 and the cap 20 covering its upper part, and this atmospheric chamber 19A is communicated with the atmosphere via an atmospheric air introduction passage (not shown). Negative pressure of the ventilate V is introduced through a small hole 17C opened at the bottom of the forming portion 17A. In addition, a needle jet 22 is opened in the ventilate V and is connected to a constant liquid level T-T in the float chamber 15 via a main jet 21. The jet needle 23 is inserted and arranged, and the gap formed by the jet needle 23 and the needle jet 22 is adjusted by raising and lowering the negative pressure operating valve 17, and the air-fuel mixture is sucked into the intake passage 2. Amount controlled.

Reference numeral 24 denotes a spring whose one end is engaged with the negative pressure operated valve 17 and the other end is engaged with the cap 20 so as to apply a downward force to the negative pressure operated valve 17.
The constant vacuum type carburetor having such a configuration can provide a constant vacuum type carburetor with extremely high suction efficiency and excellent fuel controllability due to the synergistic effect of the plate-shaped guide portion 17B and the ventilate forming portion 17A. be.

As detailed above, according to the method for manufacturing a constant vacuum type carburetor according to the present invention, the constant vacuum type vaporizer is equipped with a negative pressure operated valve that controls the intake passage by the negative pressure generated in the intake passage upstream of the throttle valve. A ventilator-forming part that forms a ventilary together with the bottom of the intake tract, and a plate-shaped guide part that protrudes laterally from a side surface along the longitudinal axis of the ventilium-forming part. A negative pressure operated valve is formed; A negative pressure operated valve is formed from the atmospheric chamber concave portion of the carburetor body toward the intake passage side, and is slidably held on one side of the ventilary forming portion and the plate-shaped guide portion of the negative pressure operated valve. death,
a guide block guide groove comprising a first ventilary forming part guide surface perpendicular to the longitudinal axis of the intake passage and a first plate-shaped guide part guide surface; The ventilary forming part of the negative pressure operating valve and the other side of the plate-shaped guide part are slidably held on the side surface opposite to the guide surface, and the first plate-shaped guide part is slidably held on the side surface opposite to the guide surface. The second orthogonal
a guide block that is fitted into a guide block guide groove, the guide block having a guide surface for a ventilule forming part and a guide surface for a second plate-shaped guide part; The guide block is inserted into the guide block guide groove with the second ventilary forming part guide surface of the guide block and the second plate-shaped guide part guide surface facing each other. 1. A ventilary forming part guide hole is formed on the second ventilary forming part guide surface, and a plate-shaped guide groove is formed on the first and second plate-shaped guide part guide surfaces, and the ventilary forming part guide hole and The ventilary forming part of the negative pressure operating valve and the plate-shaped guide part are slidably arranged in the plate-shaped guide groove, and it is extremely easy to manufacture and can reduce the manufacturing cost of the carburetor, making it practical. This has a great effect.

[Brief explanation of the drawing]

The figures show an embodiment of the constant vacuum type vaporizer according to the present invention, in which Fig. 1 is a longitudinal sectional view of the material of the vaporizer main body, Fig. 2 is a top plan view of Fig. 1, and Fig. 3 is a vertical sectional view of the material of the vaporizer main body. is a vertical sectional view taken along the line in FIG. 1, FIG. 4 is a side view of the guide member, FIG. 5 is a top plan view of FIG. 4, FIG. 6 is a right side view of FIG. 4, and FIG. FIG. 8 is a top plan view showing the guide member fitted into the carburetor body, FIG. 8 is a vertical cross-sectional view of the carburetor body incorporating desired components, and FIG. 9 is a cross-sectional view taken along the line shown in FIG. 8. be. DESCRIPTION OF SYMBOLS 1... Carburetor main body, 2... Intake path, 3... Atmospheric chamber recess, 6... Guide groove, 6A... First ventilly forming part guide surface, 6B... First plate-shaped guide member guide surface, 6C...Guide member guide groove, 7
...Guide member, 7A...Second plate-shaped guide part guide surface, 7B...Second ventilly forming part guide surface, 7C...Hole, 8A...Bentillary forming part guide hole, 8B...Plate-shaped guide Groove, 17...Negative pressure operating valve, 17A...Venture formation part, 17B
...Plate-shaped guide part.

Claims (1)

[Scope of Claims] 1. A constant vacuum carburetor equipped with a negative pressure operated valve that controls the intake passage by negative pressure generated in the intake passage upstream of the throttle valve; a negative pressure operated valve formed by a ventilule forming part forming a ventilule forming part; and a plate-shaped guide part protruding laterally from a side surface along the longitudinal axis of the ventilee forming part; is bored from the atmospheric chamber concave part toward the intake passage side, and slidably holds one side of the ventilary forming part and the plate-shaped guide part of the negative pressure operating valve,
a guide block guide groove comprising a first ventilary forming part guide surface perpendicular to the longitudinal axis of the intake passage and a first plate-shaped guide part guide surface; The ventilary forming part of the negative pressure operated valve and the other side of the plate-shaped guide part are slidably held on the side surface opposite to the guide surface, and the first plate-shaped guide part is slidably held on the side surface opposite to the guide surface. The second orthogonal
a guide block which is fitted into a guide block guide groove and has a guide surface for a ventilary forming part and a second plate-shaped guide part guide surface; The guide block is inserted into the guide block guide groove with the second ventilary forming part guide surface of the guide block and the second plate-shaped guide part guide surface facing each other. 1. A constant vacuum vaporizer in which a ventilule forming part guide hole is formed on the second ventilium forming part guide surface, and a plate-shaped guide groove is formed in the first and second plate-shaped guide part guide surfaces. Production method.