JP2527794Y2 - Vaporizer valve stem - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a carburetor for controlling the agriculture and the amount of an air-fuel mixture supplied to an engine, and more particularly, to a carburetor that spans an intake passage passing through a carburetor body. And a throttle valve shaft rotatably supported by the carburetor body.

[Prior Art] A throttle valve shaft of a carburetor generally used conventionally will be described with reference to FIG. Reference numeral 50 denotes a throttle valve shaft extending upward from below, and a small-diameter shaft portion 51 having a diameter smaller than the diameter of the throttle valve shaft 50 is formed near the upper end 50A. Further, a caulking projection 52 having a diameter smaller than the diameter of the throttle valve shaft 50 is formed upward from the upper end 50A. The lever 53 is attached to the throttle valve shaft 50 by caulking as follows. That is, 54, 55
Is the first divided in the left-right direction in FIG.
A caulking jig and a second caulking jig, and the opposing contact surfaces 56 and 57 of the caulking jig have a throttle valve shaft holding hole 58;
The small-diameter shaft portion holding hole 59 is continuously provided.

Thus, the throttle valve shaft 50 is held in a throttle valve shaft holding hole 58 formed between the first caulking jig 54 and the second caulking jig 55, and the small-diameter shaft 51 is provided with a small-diameter shaft holding hole 59. The reduced step portion 50B formed between the upper end 50A of the throttle valve shaft 50 and the small diameter shaft portion 51 at this time has the upper end 6 of the first and second caulking jigs 54 and 55.
It is placed in contact with 0.

After setting the throttle valve shaft 50 between the caulking jigs 54 and 55 in this way, insert the fitting hole 53A of the lever 53 into the caulking protrusion 52,
Thereafter, the caulking protrusion 52 protruding from the lever 53 is caulked outwardly.

[Problem to be Solved by the Invention] According to the conventional throttle valve shaft, there is the following problem.

That is, when caulking the lever to the throttle valve shaft,
The caulking projection is caulked while applying an external force to the caulking jig, and this force is intensively applied to the reduction step portion of the throttle valve shaft abutting on the upper end of the caulking jig. This is because the external force at the time of caulking of the throttle valve shaft is locked to the upper end of the caulking jig via the reduction step.

According to this, the diameter of the reduction step portion of the throttle valve shaft tends to increase outward, albeit slightly.

Here, the gap between the throttle valve shaft in the carburetor and the shaft hole for guiding the rotation of the throttle valve is limited to an extremely small gap of, for example, about 50 microns in order to control a small amount of air with the throttle valve. It must be.

Under such circumstances, if the outer diameter of the throttle valve shaft slightly increases, the rotation of the throttle valve shaft may not be smooth. For this reason, conventionally, after the caulking operation of the lever, the outer diameter of the throttle valve shaft is completely measured, or the shaft hole portion corresponding to the reduced step portion of the throttle valve shaft is additionally processed to reduce the diameter of the shaft hole. It took measures such as increasing it.

According to this work, while the throttle valve shaft can be completely rotated smoothly, the number of measurement steps or processing steps is increased, which leads to an increase in product cost of the vaporizer, which is not preferable.

[Means for Solving the Problems] The throttle valve shaft of the carburetor according to the present invention aims at reducing the product cost. A throttle valve shaft of a carburetor in which a shaft hole is drilled across an intake passage, and a throttle valve shaft having a lever attached to an end portion thereof is attached to the shaft hole so as to be rotatable. A main throttle valve shaft 1 having a diameter A and extending upward from below, a small-diameter shaft portion 2 having a diameter B smaller than the diameter A and extending upward from the upper end 1A of the main throttle valve shaft 1; Diameter B from the upper end of the part further upward
A medium-diameter shaft portion 3 having a larger diameter and a diameter C smaller than the diameter A, and a sub-throttle valve shaft having a diameter A having the same diameter as the main throttle valve shaft and extending further upward from the upper end of the middle-diameter shaft portion. A lever fitting protrusion having a diameter smaller than the diameter A extending further upward from the upper end of the sub-throttle valve shaft.
The caulking jig is formed by a first jig and a second jig having a planar contact surface that comes into contact with each other, and a main throttle valve shaft for guiding and holding the main throttle valve shaft is provided between the two contact surfaces. A holding hole, a small diameter shaft holding hole that guides and holds the small diameter shaft portion and opens at the upper end of both jigs are continuously provided, and the main throttle valve shaft is held in the main throttle valve shaft holding hole. The part is held in the small-diameter shaft holding hole, and a middle-diameter shaft step formed between the middle-diameter shaft and the small-diameter shaft is locked and disposed at the upper ends of both jigs, and the lever is pierced. The fitting hole provided is inserted into the lever fitting protrusion, and the lever fitting protrusion protruding from the lever is enlarged and caulked.

[Operation] The throttle valve shaft is held in a caulking jig, the fitting hole of the lever is inserted and arranged in the caulking protrusion, and then the caulking protrusion protruding from the lever is caulked. During this caulking operation, a downward external force acts on the throttle valve shaft, and this external force acts on the contact portion between the middle diameter shaft step portion of the middle diameter shaft portion and the upper end of the caulking jig. During this caulking operation, even if the diameter of the middle diameter shaft portion increases, it does not increase to a diameter larger than the outer diameter of the throttle valve shaft.

[Embodiment] An embodiment of the throttle valve shaft of the vaporizer according to the present invention will be described below with reference to FIG.

S is a throttle valve shaft having a circular cross section, and a main throttle valve shaft 1 having a diameter A that is upward from below in the figure.
And a small-diameter shaft portion 2 having a diameter B smaller than the diameter A of the main throttle valve shaft 1 and extending further upward from the upper end 1A of the main throttle valve shaft 1.
A medium-diameter shaft portion 3 further upward from the upper end 2A of the small-diameter shaft portion 2 and having a diameter C larger than the outer diameter B of the small-diameter shaft portion 2 and smaller than the outer diameter A of the main throttle valve shaft 1; , The upper end of the middle diameter shaft 3
3A, a sub-throttle valve shaft 4 having the same diameter as the diameter A of the main throttle valve shaft 1, and a projecting upper end 4A of the sub-throttle valve shaft 4 further projecting upward. Is formed by a lever fitting projection 5 having a diameter smaller than the diameter A of the sub-throttle valve shaft 3.

That is, the throttle valve shaft S is arranged such that the main throttle valve shaft 1, the small-diameter shaft portion 2, the medium-diameter shaft portion 3, the sub-throttle valve shaft 4,
A lever fitting projection 5 is provided in series.

In particular, between the lower end 3B of the middle diameter shaft portion 3 and the upper end 2A of the small diameter shaft portion 2, an annular middle diameter step portion 3C facing downward is formed.

G is a caulking jig used for attaching the lever 53 to the throttle valve shaft S, and is a flat contact surface 6 which is in contact with each other.
The first and second jigs 6 and 7 having A and 7A are formed. (The caulking jig G is shown in FIG. 3.) The main throttle valve shaft 1 is held between the confronting surfaces of the caulking jig G in a state where the two opposing surfaces 6A and 7A are in contact with each other. A main throttle valve shaft holding hole 8 and a small diameter shaft holding hole 9 for holding the small diameter shaft 2 are provided continuously. The diameter of the small diameter shaft holding hole 9 is smaller than the diameter of the main throttle valve shaft holding hole 8.

That is, the caulking jig G is formed with the main throttle valve shaft holding hole 8 and the small-diameter shaft portion holding hole 9 opening at the upper ends 6B and 7B of the caulking jig from below to above.

Here, the lever 53 is attached to the throttle valve shaft S as follows. First, the throttle valve shaft S is disposed in the caulking jig G.

That is, the main throttle valve shaft 1 is held in the main throttle valve shaft holding hole 8, the small-diameter shaft portion 2 is held in the small-diameter shaft portion holding hole 9,
The middle diameter shaft step 3C is the upper end 6B, 7B of the caulking jig G.
Is held in contact with.

At this time, the auxiliary throttle valve shaft 4 including the lever fitting protrusion 5 is
The lever 53 is located above the caulking jig G, and a fitting hole 53A formed in the lever 53 is inserted into the lever fitting protrusion 5 and arranged.

In this state, the lever fitting projection 5 protruding upward from the lever 53 is caulked downward, whereby the throttle valve shaft S and the lever 53 can be caulked and attached. is there.

During the caulking operation of the lever fitting projection 5, a downward external force on the throttle valve shaft S is applied to the caulking jig G via the medium diameter shaft step 3C of the medium diameter shaft portion 3 of the throttle valve shaft S. Upper end 6
Join B and 7B.

According to this, the diameter C of the middle diameter shaft portion 3 tends to increase, but since the diameter C of the middle diameter shaft portion 3 is smaller than the diameter A of the auxiliary throttle valve shaft 3, the diameter C of the middle diameter shaft portion 3 is small. C does not become larger than the diameter A of the auxiliary throttle valve shaft 3.

The throttle valve shaft S with the lever 53 caulked and attached as described above.
In order to assemble into the carburetor, a shaft hole 22 should be formed across the intake passage 21 penetrating the carburetor body 20, and the throttle valve shaft S should be inserted into the shaft hole 22. This is shown in FIG.

Although the above embodiment has been described with respect to the throttle valve shaft, the same effect can be obtained with a choke valve shaft for mounting a choke valve.

[Effects of the Invention] As described above, according to the throttle valve shaft of the carburetor of the present invention, when the lever is swaged to the throttle valve shaft, the shaft diameter of any part of the throttle valve shaft is adjusted to the maximum shaft diameter of the throttle valve shaft. Since it does not expand beyond A, the outer diameter of the throttle valve shaft is measured again after lever caulking work, or the shaft hole that matches the diameter of the throttle valve shaft is replaced with a shaft hole with a larger diameter. Since it is no longer necessary to use the two-stage hole, the production cost of the vaporizer can be reduced, and this has a great effect in practical use.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a conventional throttle valve shaft, FIG. 2 is a side view showing one embodiment of a throttle valve shaft of the carburetor of the present invention, FIG.
FIG. 4 is a longitudinal sectional view showing a state in which the lever is mounted on a caulking jig for caulking the throttle valve shaft shown in FIG. 2, and FIG. It is a longitudinal cross-sectional view showing the state arrange | positioned at. S ... Throttle valve shaft 1 ... Main throttle valve shaft 2 ... Small diameter shaft portion 3 ... Medium diameter shaft portion 3C ... Medium diameter shaft step portion 4 ... Sub throttle valve shaft 5 ... Lever fitting projection G …… Caulking jig 8 …… Main throttle valve shaft holding hole 9 …… Small diameter shaft holding hole 53 …… Lever

Claims (1)

(57) [Scope of request for utility model registration] 1. A carburetor body having an intake passage penetrating therethrough, a shaft hole is formed across the intake passage, and a throttle valve shaft having a lever attached to an end portion thereof is attached to the shaft hole to rotate the throttle valve shaft. The throttle valve shaft S of the carburetor movably disposed includes a main throttle valve shaft 1 having a diameter A and extending upward from below, and further upward from an upper end 1A of the main throttle valve shaft 1. A small-diameter shaft portion 2 having a diameter B smaller than the diameter A, and a medium-diameter shaft portion 3 having a diameter C larger than the diameter B and smaller than the diameter A further upward from the upper end 2A of the small-diameter shaft portion 2; A sub-throttle valve shaft 4 having a diameter A having the same diameter as the main throttle valve shaft 1 and extending further upward from the upper end 3A of the medium-diameter shaft portion 3;
A lever fitting projection 5 having a diameter D smaller than the diameter A extending further upward from the upper end 4A of the sub-throttle valve shaft 4 is formed. It is formed by the first jig 6 and the second jig 7 having the contact surfaces 6A and 7A, and the main throttle valve shaft 1 is provided between the two contact surfaces 6A and 7A.
A main throttle valve shaft holding hole 8 for guiding and holding a small diameter shaft portion 2 and a small diameter shaft portion holding hole 9 for guiding and holding the small diameter shaft portion 2 and opening at upper ends 6B and 7B of both jigs 6 and 7 are provided continuously. The valve shaft 1 is held in a main throttle valve shaft holding hole 8, the small diameter shaft portion 2 is held in a small diameter shaft holding hole 9, and is formed between the medium diameter shaft portion 3 and the small diameter shaft portion 2. The middle diameter stepped portion 3C is the upper end 6B of both jigs 6 and 7,
Fitting hole that is locked with 7B and drilled in lever 53
A throttle valve shaft for a carburetor, wherein 53A is inserted into the lever fitting projection 5 and the lever fitting projection 5 projecting from the lever 53 is enlarged and caulked.