JP2002221095A - Fluid adjusting screw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve and equalize the precision in controlling fluid by equalizing the ring-shaped gap formed between a tapered needle valve part and a measuring hole by improving the concentric precision of a fluid adjusting screw and a screw hole for guiding the screw. SOLUTION: A large diameter cylinder part 5 and a small diameter guide cylinder part 6 are formed concentrically from a male screw part 3 of the fluid adjusting screw P toward the tapered needle valve part 4. A female screw part 10, a large diameter guide hole 11, a small diameter guide hole 12, and the measuring hole are bored concentrically in a fluid controller 1 inward from the outer side end. The male screw part 3 of the fluid adjusting screw P is attached to the female screw part 10, the large diameter guide cylinder part 5 is supported at the large diameter guide hole 11 and the small diameter guide cylinder part 6 is supported at the small diameter guide hole 12. Further, the tapered needle valve part 4 is inserted into the measuring hole 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid controller which is disposed in a fluid controller such as a vaporizer or a throttle body and regulates a fluid such as a low-speed mixture or low-speed air which is controlled in the fluid controller. The present invention relates to a fluid adjusting screw used in the present invention.

[0002]

2. Description of the Related Art A fluid adjusting screw used in a conventional fluid controller will be described with reference to FIG. The fluid controller in this example is a vaporizer, and the fluid adjustment screw is a pilot screw for adjusting a low-speed air-fuel mixture. Hereinafter, the adjusting screw is referred to as a pilot screw. Reference numeral 1 denotes a carburetor body through which an intake passage 2 penetrates, and many elements constituting the carburetor are omitted. P is a pilot screw as a fluid adjusting screw for adjusting the low-speed air-fuel mixture, and is composed of the following. Reference numeral 30 denotes a male screw portion provided at the rear end, and an adjustment groove 30A is formed in the rear end surface. 31
Is a tapered needle valve portion provided at the tip thereof, and the male screw portion 30 and the tapered needle valve portion 31 are connected as follows. That is, a small-diameter guide cylinder portion 32 is continuously provided from the distal end of the male screw portion 30 toward the tapered needle valve portion 31, and the distal end of the small-diameter guide cylinder portion 32 and the rear end of the tapered needle valve portion 31 are separated from the small-diameter guide cylinder portion 32. They are connected by a connecting portion 33 having a small diameter. That is, the pilot screw P has a male screw part 30, a small-diameter guide cylinder part 32,
The connecting portion 33 and the tapered needle valve portion 31 are continuously provided, and the respective portions are formed concentrically. The pilot screw is generally made of a brass material by lathing.
On the other hand, the following holes are continuously formed in the vaporizer main body 1. A female screw portion 40 (including a screw hole of the female screw portion 40) into which the male screw portion 30 is screwed inward from the outer end of the carburetor main body 1, a small-diameter guide hole 41 for guiding and supporting the small-diameter guide cylindrical portion 32; A measuring hole 42 into which the tapered needle valve portion 31 enters is continuously provided, and the female screw portion 40, the small-diameter guide hole 41, and the measuring hole 42 are formed concentrically. Also, measuring hole 4
A low-speed mixture inflow passage 43 is connected to the upstream side of 2, a low-speed mixture outflow passage 44 is connected to the downstream side of the metering hole 42,
The downstream side of the low-speed mixture outflow passage 44 is communicated with the intake passage 2. The pilot screw P is disposed on the carburetor body 1 as follows. The pilot screw P has an internal thread 4 that opens toward the outer end of the vaporizer main body 1.
0, the male screw portion 30 is screwed into the female screw portion 40.
The small-diameter guide cylinder portion 32 is supported by the small-diameter guide hole 41 so as to be movable in the axial direction, and the tapered needle valve portion 31 is
Is placed inside. S is the pilot screw P
Is pressed to one side to eliminate backlash between the male screw portion 30 and the female screw portion 40.

In the pilot screw P constituted as described above, when the driver enters the adjusting groove 30A and rotates, for example, clockwise, the pilot screw P advances inward, and is formed by the tapered needle valve portion 31 and the measuring hole 42. The measurement gap formed is reduced, and the amount of the low-speed mixture supplied from the low-speed mixture outflow passage 44 into the intake passage 2 can be adjusted in the decreasing direction. On the other hand, when the pilot screw P is rotated in the counterclockwise direction, the pilot screw P advances outward, increasing the metering gap formed by the tapered needle valve portion 31 and the metering hole 42, and causing the low-speed mixture outflow passage. The amount of the low-speed air-fuel mixture supplied from the air intake 44 into the intake path 2 can be adjusted in the increasing direction.

[0004]

According to such a conventional fluid adjusting screw, a female screw portion 40, a small-diameter guide hole 41, a measuring hole 42 (generally referred to as a screw hole) formed in the vaporizer main body 1 and a fluid. It is difficult to accurately adjust the concentric accuracy with the adjusting screw. This is because even if the screw holes (female screw portion 40, small diameter guide hole 41, measuring hole 42) and the fluid adjustment screw and the concentricity of the fluid adjustment screw itself are accurately maintained, the fluid adjustment screw is arranged in the screw hole. In this state, mutual concentricity cannot be maintained accurately. This is because the fluid adjusting screw is supported by the small-diameter guide hole 41 only by the small-diameter guide cylinder 32. The fact that the concentricity cannot be maintained accurately means that the shape of the annular gap formed by the tapered needle valve portion 31 and the metering hole 42 cannot be maintained uniformly. When supplying uniformly and uniformly, there is a problem. On the other hand, in order to improve the concentric accuracy, the first
It is considered that the guide length between the guide cylinder 32 and the first guide hole 41 is increased. However, according to this, the total length of the adjusting screw becomes longer, and the fluid controller cannot be made compact.

[0005] The fluid adjusting screw according to the present invention has been made in view of the above-mentioned problems, and the fluid adjusting screw and the guide for the fluid adjusting screw are provided with a small change from the conventional adjusting screw without increasing the overall length of the adjusting screw. An object of the present invention is to improve the accuracy of concentricity with a screw hole to be performed, and to thereby make fluid control extremely uniform and accurate.

[0006]

In order to achieve the above object, the fluid adjusting screw according to the present invention is provided in a fluid controller such as a carburetor or a throttle body and has a low-speed mixture or a low-speed mixture controlled by the fluid controller. In a fluid adjusting screw for adjusting a fluid such as low-speed air, the fluid adjusting screw has a tapered needle valve portion at its front end, an external thread portion at its rear end, and a large-diameter guide cylinder portion from the external thread portion to the tapered needle valve portion. And the small-diameter guide cylinder portion are connected to each other, and the male screw portion, the large-diameter guide cylinder portion, the small-diameter guide cylinder portion, and the tapered needle valve portion are formed concentrically. A female thread portion, a large-diameter guide hole, a small-diameter guide hole, and a measuring hole are formed concentrically toward the direction, and the male thread portion of the fluid adjusting screw is screwed to the female thread portion, and the large-diameter guide cylinder portion has a large diameter. Support with guide holes With supporting the small-diameter guide tube portion at the small-diameter guide holes, characterized by further entering disposed a tapered needle valve section into the measuring hole.

[0007]

According to the fluid adjusting screw of the present invention, the fluid adjusting screw has a large-diameter guide cylinder portion supported by the large-diameter guide hole, and a small-diameter guide cylinder portion supported by the small-diameter guide hole. Can be accurately and concentrically arranged in a screw hole including a female screw portion, a large diameter guide hole, a small diameter guide hole, and a measurement hole, and in particular, the tapered needle valve portion can be accurately and uniformly inserted into the measurement hole. Therefore, it is possible to accurately and uniformly adjust and control the fluid such as the low-speed air-fuel mixture.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the fluid adjusting screw according to the present invention will be described below with reference to FIG. The fluid controller in this example is a vaporizer as in the conventional example, and the same components are denoted by the same reference numerals. Reference numeral 1 denotes a fluid controller, which is a carburetor in this example, and has an intake passage 2 penetrating therethrough. P is a fluid adjusting screw, which in this example is a pilot screw for adjusting the low-speed air-fuel mixture. The fluid adjusting screw P includes the following. Reference numeral 3 denotes a male screw portion provided at the rear end, and an adjusting groove 3A such as a minus groove or a plus groove is formed in the rear end surface. Reference numeral 4 denotes a tapered needle valve portion provided at the tip, and the male screw portion 3 and the tapered needle valve portion 4 are connected as follows. A large-diameter guide cylinder portion 5 and a small-diameter guide cylinder portion 6 are provided continuously from the distal end of the male screw portion 3 toward the tapered needle valve portion 4, and the distal end of the small-diameter guide cylinder portion 6 is tapered through a conical portion. It is connected to the rear end of the needle valve section 4.
That is, in the fluid adjusting screw P, the male screw portion 3, the large-diameter guide tube portion 5, the small-diameter guide tube portion 6, and the tapered needle valve portion 4 are continuously provided from the rear end toward the front end, and the respective portions are concentric. It is formed.

The fluid controller 1 is a vaporizer in this embodiment, and the following holes are continuously provided from the outer end of the fluid controller 1 to the inside. Reference numeral 10 denotes a female threaded portion that is open simply facing the outside of the fluid controller 1, and has a large-diameter guide hole 11, a small-diameter guide hole 12 having a smaller diameter than the large-diameter guide hole 11, and inward from the lower end of the female thread portion 10. Further, a measuring hole 13 is formed. The female thread portion 10, the large-diameter guide hole 11, the small-diameter guide hole 12, and the measuring hole 13 are formed concentrically.

[0010] The fluid adjusting screw P is inserted into the fluid controller 1 through a female threaded portion 10 which opens toward the outer end of the fluid controller 1. The large-diameter guide cylinder 5 is axially movably supported by a large-diameter guide hole 11, the small-diameter guide cylinder 6 is axially movably supported by a small-diameter guide hole 12, and a tapered needle. The valve part 4 is arranged to enter the measuring hole 13.

In the above-mentioned fluid adjusting screw P, when the driver enters the adjusting groove 3A and rotates, for example, clockwise, the fluid adjusting screw P advances inward, and the tapered needle valve portion 4 and the measuring hole 13 are rotated. And the metering gap formed by the above is reduced, and the amount of the low-speed mixture supplied from the low-speed mixture outflow passage 44 into the intake passage 2 can be adjusted in the decreasing direction. On the other hand, when the fluid adjusting screw P is rotated in the counterclockwise direction, the fluid adjusting screw P advances outward, increasing the metering gap formed by the tapered needle valve portion 4 and the metering hole 13 to reduce the low speed mixing. Air outflow channel 4
4, the amount of the low-speed mixture supplied to the intake path 2 can be adjusted in the increasing direction.

According to the fluid adjusting screw P according to the present invention, the adjusting screw is supported by the large-diameter guide hole 11 so that the large-diameter guide portion 5 located at a position separated upward in the axial direction is movable in the axial direction. The small-diameter guide portion 6 positioned axially below is supported by the small-diameter guide hole 12 so as to be movable in the axial direction. The taper needle valve portion 4 of the fluid adjusting screw P, particularly the tapered needle valve portion 4 is accurately centered in the metering hole 13. Is done. According to the above, when the fluid adjusting screw P is rotated, when the biasing force acts on the fluid adjusting screw P by an adjusting tool such as a screwdriver inserted into the adjusting groove 3A, or when the fluid adjusting screw P is Even when a biasing force acts on P, the annular gap formed by the tapered needle valve portion 4 and the metering hole 13 can always be uniformly formed in an accurate annular gap. An accurate and uniform low-speed air-fuel mixture can be stably supplied to the fluid controller 1 from the air-fuel mixture outflow passage 44.
In this embodiment, the control of the low-speed air-fuel mixture of the carburetor has been described. However, the present invention can be used for the control of the low-speed air, and may be used for an air adjusting screw for adjusting an idling air amount in a throttle body. When the large-diameter guide hole 11 uses the diameter of the screw hole of the female thread portion 10, the large-diameter guide hole can be easily manufactured. Further, the fluid adjusting screw P is supported at two points in the axial direction by the first guide by the large-diameter guide cylinder 5 and the second guide by the small-diameter guide cylinder 6, so that the length of each guide is small. The length of the fluid adjustment screw P does not need to be longer than that of the conventional screw.

[0013]

As described above, according to the present invention, the fluid adjusting screw P has the male screw portion 3, the large-diameter guide cylinder portion 5, the small-diameter guide cylinder portion 6, the tapered needle valve portion 4 from the rear end toward the front end.
The male screw portion 3 is screwed to a female screw portion 10 provided in the fluid controller 1 to support the large-diameter guide cylinder portion 5 in the large-diameter guide hole 11 and the small-diameter guide cylinder portion 6.
Is supported in the small-diameter guide hole 12, and the tapered needle valve portion 4 is further arranged to enter the measuring hole 13. Thereby, the falling of the fluid adjusting screw P is completely suppressed, and the tapered needle valve portion 4 and the measuring hole 13 can accurately and uniformly form an annular gap formed thereby, and uniform and accurate fluid control can be achieved. Further, since the fluid adjusting screw P is supported at two locations by the large-diameter guide cylinder 5 and the small-diameter guide cylinder 6, there is no need to increase the length of the fluid adjustment screw P, and the fluid controller 1 becomes large. And this can be easily adopted into conventional fluid controllers.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a fluid adjusting screw according to the present invention.

FIG. 2 is a longitudinal sectional view of a main part of a conventional fluid adjusting screw.

[Explanation of symbols]

 P Fluid adjustment screw 1 Fluid controller 3 Male screw part 4 Tapered needle valve part 5 Large diameter guide cylinder part 6 Small diameter guide cylinder part 10 Female thread part 11 Large diameter guide hole 12 Small diameter guide hole 13 Measuring hole

Claims (1)

[Claims] 1. A fluid adjusting screw disposed in a fluid controller such as a carburetor or a throttle body for adjusting a fluid such as a low-speed air-fuel mixture or a low-speed air controlled by the fluid controller. A tapered needle valve portion 4 is provided at the tip thereof, and a male screw portion 3 is provided at the rear end. A large-diameter guide cylinder portion 5 and a small-diameter guide cylinder portion 6 are connected from the male screw portion 3 toward the tapered needle valve portion 4 and are connected to each other. Male screw part,
The large-diameter guide cylinder portion 5, the small-diameter guide cylinder portion 6, and the tapered needle valve portion 4 are formed concentrically. On the other hand, the fluid controller 1 includes a female thread portion 10 and a large-diameter guide from the outer end toward the inside. Hole 11
And a small diameter guide hole 12 and a measuring hole 13 are formed concentrically,
The male screw portion 3 of the fluid adjusting screw is screwed into the female screw portion 10, the large-diameter guide cylinder portion 5 is supported by the large-diameter guide hole 11, and the small-diameter guide cylinder portion 6 is supported by the small-diameter guide hole 12. A fluid adjusting screw in which a tapered needle valve part (4) is arranged to enter into a measuring hole (13).