JPH08521Y2 - Sliding throttle valve of carburetor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a carburetor that controls the amount and concentration of an air-fuel mixture supplied to an engine, and in particular, controls the opening and closing of the intake passage of the carburetor with a sliding throttle valve. It is related to the attachment of the operation wire to the sliding throttle valve, and is often used in the carburetor for motorcycles.

[Prior Art] Conventionally, a sliding throttle valve of a carburetor is well known from Japanese Utility Model Publication No. 56-143548.

This structure consists of a wire end insertion hole formed in the recess wall of the recess for the throttle valve return spring and a side where the wire end can be stored in the longitudinal direction at a position where a gap is provided at the bottom of the recess bottom. A hole is provided, and the side hole and the wire end insertion hole of the recess wall are communicated with each other by a wire groove provided in a gap portion.

[Problems to be Solved by the Invention] According to such a conventional sliding throttle valve of a carburetor, when the sliding throttle valve is rapidly returned from the fully open state to the low opening state, the low opening degree of the sliding throttle valve is reduced. When the return speed of the wire (wire end) is faster than the return speed to the state, it is predicted that the wire end arranged at the end of the wire will be dislocated from the side hole to the outside of the sliding throttle valve.

[Means for Solving the Problems] The sliding throttle valve of the carburetor according to the present invention is intended to completely solve such a problem, and penetrates the carburetor main body in order to achieve the above object. A sliding throttle valve of a carburetor in which a throttle valve guide tube that movably supports the sliding throttle valve is connected to the intake passage, and the sliding throttle valve is connected to a wire through a wire end. The dynamic throttle valve is provided with a holder protrusion that is located above the inner bottom of the slider and has an annular gap with the inner wall of the sliding throttle valve. The wire end is inserted into the holder protrusion from the side. A wire end insertion groove to be obtained, and a wire insertion groove which is connected to the wire end insertion groove via a locking step portion orthogonal to the longitudinal axis direction XX of the sliding throttle valve and into which a wire can be inserted from the side Is provided, and outside the sliding throttle valve The wall is provided with a second wire end insertion groove that corresponds to at least the wire end insertion groove and reaches the upper end of the sliding throttle valve so that the wire end can be inserted inside the sliding throttle valve. The cup-shaped holder member arranged corresponding to the portion, the wire end through hole through which the wire end can be inserted in the central part, and the wire through hole which extends laterally from the wire end through hole and through which the wire W can be inserted Are formed by a flat surface portion and an annular side surface portion that extends downward from the outer peripheral end of the flat surface portion.

[Operation] The wire end is inserted and arranged in the wire end insertion groove of the holder protrusion through the second wire end insertion groove of the sliding throttle valve, and the wire is inserted and arranged in the wire insertion groove of the holder protrusion. .

The opening to the outer periphery of the holder protrusion of the wire end insertion groove and the wire insertion groove is closed and held by the side surface portion of the holder member arranged corresponding to the holder protrusion.
Therefore, the wire end is housed in the wire end insertion groove.

[Example] The sliding throttle valve of the carburetor according to the present invention will be described below.
It will be described with reference to the drawings.

Reference numeral 1 denotes a carburetor body having an intake passage 2 penetrating the inside thereof,
A throttle valve guide cylinder 3 that slidably guides and holds a slide throttle valve, which will be described later, is continuously provided from the intake passage 2 and opens upward.

A top 5 having an insertion hole 4 at its center is screwed onto the outer periphery of the upper portion of the throttle valve guide cylinder 3.

The hole diameter of the insertion hole 4 of the top 5 is a hole diameter through which a wire end described later can pass.

Further, a float chamber main body 6 is arranged below the vaporizer main body 1, and a float chamber 7 is formed by the vaporizer main body 1 and the float chamber main body 6. In the float chamber 7, a float 8, a valve seat,
A constant liquid surface is always formed by a float valve (not shown) or the like.

Further, a needle jet 11 connected to a main jet 9 and a mixing nozzle 10 arranged below a constant liquid level in the float chamber 7 opens in the intake passage 2. A sliding throttle valve 12 capable of opening and closing the intake passage 2 is slidably arranged in the throttle valve guide cylinder 3. Then, the following structure is added to the sliding throttle valve 12.

That is, 12A is a holder protrusion formed by protruding upward from the inner bottom portion 12B of the sliding throttle valve 12, and between the outer periphery of the holder protrusion 12A and the inner wall D of the sliding throttle valve 12. An annular gap 12C, which is the gap H, is formed in the space. The inner bottom 1
2B is the outer bottom portion of the sliding throttle valve 12 that opens facing the intake passage 2.
It never reaches 12D.

A jet needle insertion hole 12E for supporting the jet needle 13 inserted into the needle jet 11 is provided at the outer bottom portion 12D at the center of the holder projection 12A along the longitudinal axis direction XX of the sliding throttle valve 12. Is drilled toward.

Therefore, when the jet needle 13 having the collar portion 13A on the upper portion thereof is inserted into the jet needle insertion hole 12E, the collar portion 13A is arranged on the upper surface 12P of the holder protrusion 12A and the lower portion of the jet needle 13 is needle jet. It is inserted and arranged in 11.

In addition, a wire end insertion groove 12F and a wire insertion groove 12G are continuously formed in the outer periphery of the holder protrusion 12A on one side in the vertical direction.

The wire end insertion groove 12F is at the lower position, and one side (right side in FIG. 1) of the holder protrusion 12A is provided so that the wire end E attached to the end of the wire W can be inserted into the groove from the side. On the other hand, the wire insertion groove 12G is located above the wire end insertion groove 12F, and one side (right side in FIG. 1) of the wire W can be inserted into the groove from the side. The holder protrusion 12A opens to one side.

That is, the lower part of the wire insertion groove 12G is connected to the wire end insertion groove 12F, and the upper part reaches the upper surface 12P of the holder protrusion 12A. The wire end insertion groove 12F and the wire insertion groove 12G are arranged in the longitudinal axis direction XX of the sliding throttle valve 12.
Is connected at a locking step portion 12H that is orthogonal to.

Furthermore, on the outer peripheral wall 12J of the sliding throttle valve 12, a second wire end inserting groove 12K that faces the wire end inserting groove 12F formed in the holder protrusion 12A and reaches the upper end 12R of the sliding throttle valve 12 is formed. Is drilled. (The lower end of the second wire end insertion groove 12K does not reach the outer bottom portion 12D of the sliding throttle valve 12.) 14 is a cup-shaped holder member having the following structure. (Details are shown in FIG. 2.) The holder member 14 is composed of a flat surface portion 14A and an annular side surface portion 14B and has an opening at the lower side in the drawing, and the wire end E can be inserted through the center of the flat surface portion 14A. Wire end through hole 14
C is formed, and a wire through hole 14D through which the wire W can be inserted is formed on the side of the wire end through hole 14C.

The flat portion 14A of the holder member 14 is the upper surface of the holder protrusion 12A.
12P, and the side surface portion 14B has an annular gap 12 formed between the outer periphery of the holder protrusion 12A and the inner wall D of the sliding throttle valve 12.
Located in C.

Reference numeral 15 is a spring that is contracted between the flat portion 14A of the holder member 14 and the top 5.

Next, assembling of the wire W including the sliding throttle valve 12 and the wire end E into the vaporizer will be described with reference to FIG. First, the top 5, the spring 15, the holder member 14, and the slide throttle valve 12 in which the jet needle 13 is inserted into the jet needle insertion hole 12E are arranged from above in the figure, and then the insertion hole 4 of the top 5 is inserted. The second wire end insertion groove 12K of the sliding throttle valve 12 after the wire end E is inserted inside the spring 15 and in the wire end through hole 14C of the holder member 14 (the wire end in the one-dot chain line state in FIG. 3). Slide the wire end E through the sliding throttle valve 12
Insert it into the wire end insertion groove 12F.

This state is the wire end in the solid line state in FIG. Then, the sliding throttle valve 12 in such a state is inserted into the throttle valve guide cylinder 3 of the carburetor main body 1, and then the flat surface portion 14A of the holder member 14 is arranged on the upper surface 12P of the holder protrusion 12A and the side surface portion thereof. 14B is placed in the annular gap 12C and then the spring 15 on the flat portion 14A of the holder member 14
While compressing, the top 5 is screwed onto the upper portion of the throttle valve guide cylinder 3.

According to the above, the sliding throttle valve 12 is arranged in the throttle valve guide cylinder 3, and the flat portion 14A of the holder member 14 and the top 5 arranged on the upper surface 12P of the holder protrusion 12A of the sliding throttle valve 12 are connected. A spring 15 is contracted between them, and the holder member 14 is elastically pressed by the spring 15 against the upper surface 12P of the holder projection 12A to be positioned.

In such a state, the wire end E is the sliding throttle valve.
The wire W is in the wire insertion groove 12F of the sliding throttle valve 12, the wire W is in the wire insertion groove 12G of the holder protrusion 12A of the sliding throttle valve 12, and the side surface of the holder member 14 is located outside the wire end E and the wire W. The portion 14B is arranged to prevent the wire end E from laterally escaping from the wire end insertion groove 12F and the wire W from laterally escaping from the wire insertion groove 12G.

The wire W directed to the operating rod (not shown) extends to the outside of the carburetor main body 1 through the wire through hole 14D of the holder member 14, the inside of the spring 15 and the through hole 4 of the top 5 and is connected to the operating rod. To be done.

Next, the operation will be described. When the wire W is pulled upward by the driver during the opening operation of the sliding throttle valve 12, the wire end E moves upward, and the upper end of the wire end E has a locking step portion 12H of the wire end insertion groove 12F. The sliding throttle valve 12 moves upward against the elastic force of the spring 15 in synchronization with the wire end E, and opens the intake passage 2 in response to the upward movement of the wire W.

On the other hand, when the wire W is returned by the driver when the sliding throttle valve 12 is operated in the closing direction, the wire end E moves downward and the upward pulling by the wire end E is released. The throttle valve 12 closes the intake passage 2 in response to the return of the wire W by the elastic force of the spring 15.

When the sliding throttle valve 12 is operated in the closing direction, the wire end E is compared with the moving speed of the sliding throttle valve 12 in the closing direction.
When the return speed is fast, the wire end E does not escape from the wire end insertion groove 12F toward the outside of the sliding throttle valve 12. According to the present invention,
Since the outer peripheral opening of the wire end insertion groove 12F is closed by the side surface portion 14B of the holder member 14, the wire end E does not escape from the wire end insertion groove 12F.

On the other hand, the collar 13A of the jet needle 13 is the holder member 1
The jet needle 13 can be reliably held by the sliding throttle valve 12 because it is constantly pressed by the flat surface portion 14A of 4.

Further, a wire end insertion groove is formed in the venturi portion V formed by the outer bottom portion 12D of the sliding throttle valve 12 and the intake passage 2.
Since the 12F and the second wire end insertion groove 12K are not opened at all, the airflow flowing through the venturi V is stable, and the intake negative pressure acting on the needle jet 11 can be stabilized, thus improving fuel controllability. Was achieved.

The second wire end insertion groove 12K is at a position corresponding to at least the holder protrusion 12A of the sliding throttle valve 12,
Since the sliding throttle valve 12 is not penetrated from the upper end 12R to the lower end, the rigidity of the sliding throttle valve 12 can be increased and the dimensional accuracy such as the circularity of the sliding throttle valve 12 can be increased. Can be accurately formed.

[Effect of the Invention] As described above, the sliding throttle valve type carburetor according to the present invention has the following special effects.

When the sliding throttle valve and the wire end are engaged, the wire end is arranged in the wire end insertion groove formed in the holder protrusion, and the wire connected to the wire end is the wire insertion groove formed in the holder protrusion. It is arranged inside, and the side surface of the holder member is arranged to face the wire end and the wire.When the sliding throttle valve is closed, the wire end and the wire are inserted into the wire end insertion groove and the wire insertion groove. It can be stably disposed inside, and the return characteristic of the sliding throttle valve can be further stabilized.

The jet needle can be securely held against the sliding throttle valve because the flange part provided on the top of the jet needle is constantly pressed by the flat part of the holder member.In particular, a special part for holding the jet needle is required. Since it was possible to share the parts without providing them, it is possible to significantly reduce the cost.

The second wire end insertion groove formed on the outer peripheral wall of the sliding throttle valve does not reach at least the outer bottom portion of the sliding throttle valve.

That is, since the groove that penetrates along the axial direction from the upper end to the lower end of the sliding throttle valve is not formed, it is possible to disturb the air flow flowing through the venturi portion formed by the outer bottom portion of the sliding throttle valve and the intake passage. Since it is possible to obtain a stable needle jet negative pressure state without any problem, good fuel controllability can be obtained, and the rigidity of the sliding throttle valve can be maintained high, and the dimensional accuracy of the sliding throttle valve can be maintained. (In particular, the roundness) can be favorably maintained, and particularly the controllability of the minute air amount can be improved.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a sliding throttle valve of a carburetor according to the present invention, FIG. 2 is a perspective view of a holder member, and FIG. 3 is a view of assembling a wire end to the sliding throttle valve. FIG. 12 …… Sliding throttle valve 12A …… Holder protrusion 12B …… Inner bottom 12C …… Ring gap 12D …… Outer bottom 12E …… Jet needle insertion hole 12F …… Wire end insertion groove 12G …… Wire insertion groove 12H… … Locking step 12J …… Outer wall 12K …… Second wire end insertion groove 12P …… Upper surface of holder protrusion 12A 12R …… Upper end of sliding throttle valve 13 …… Jet needle 14 …… Holder member 14A… … Plane 14B …… Side 14C …… Wire end through hole 14D …… Wire through hole H …… Gap W …… Wire E …… Wire end

Claims (1)

[Scope of utility model registration request] 1. A throttle valve guide tube for movably supporting a sliding throttle valve is continuously provided on an intake passage passing through a carburetor main body, and the sliding throttle valve is connected to a wire through a wire end. In the sliding throttle valve of the carburetor, the sliding throttle valve 12 has an annular gap 12C which extends upward from the inner bottom portion 12B thereof and forms a gap H with the inner wall D of the sliding throttle valve 12.
And a holder projection 12A having a wire end insertion groove 12F into which the wire end E can be inserted from the side, and a longitudinal axis direction XX of the sliding throttle valve 12.
Wire end insertion groove 1 via locking step 12H that is orthogonal to
A wire insertion groove 12G that is connected to 2F and into which the wire W can be inserted from the side is provided. Furthermore, the outer peripheral wall 12J of the sliding throttle valve 12 corresponds to at least the wire end insertion groove 12F and also has a sliding throttle valve. A second wire end insertion groove 12K that reaches the upper end 12R of 12 and allows the wire end E to be inserted into the inside of the sliding throttle valve 12 is provided. On the other hand, a cup-shaped holder arranged corresponding to the holder protrusion. The member 14 has a flat surface portion in which a wire end through hole 14C through which the wire end E can be inserted and a wire through hole 14D which extends laterally from the wire end through hole 14C and through which the wire W can be inserted are formed. 14A and an annular side surface portion 14B that extends downward from the outer peripheral end of the flat surface portion 14A, and a holder protrusion of a wire end insertion groove 12F into which the wire end E is inserted and arranged via a second wire end insertion groove 12K. At 12A The opening to the outer circumference and the opening to the outer circumference of the holder protrusion 12A of the wire insertion groove 12G into which the wire W is inserted and arranged are closed by the side surface portion 14B of the holder member 14 arranged corresponding to the holder protrusion 12A. A sliding throttle valve of a carburetor, which is held in a state and in which a wire W is inserted into a wire through hole 14D of a flat surface portion 14A of a holder member 14.