JP7152008B2 - needle and needle valve - Google Patents

Description

The present invention relates to a needle provided in a needle valve used for controlling the flow rate of fluid supplied to an internal combustion engine, and a needle valve provided with the needle.

Conventionally, it is known to use a needle valve to control the flow rate of fluid supplied to an internal combustion engine. A needle valve is a type of fluid flow control valve, and has a valve body and a needle. By changing the size of the gap between the valve seat of the valve body and the tip of the needle, the flow rate of the fluid passing through the gap is adjusted (see Patent Documents 1 and 2).

A conventional needle will be described with reference to FIG. FIG. 4 is an exploded view showing an example of a conventional needle. The needle 100 includes a needle core rod 10 inserted into a flow hole of the valve body (not shown), an O-ring 60 fitted on the needle core rod 10 to prevent fluid from leaking out, and a needle core rod 10 to prevent the needle core rod 10 from coming out of the valve body. a knob 70 for adjusting the insertion length of the needle core rod 10 by rotating it; and a knob fixing nut 80 for fixing the knob 70 to the needle core rod 10. - 特許庁

By changing the size of the gap between the valve seat of the valve body and the tip of the needle core rod 10, the flow rate of the fluid passing through the gap is adjusted. The size of the gap is changed by rotating the knob 70 to adjust the insertion length of the needle core rod 10 . A nut 20 is screwed onto the valve body. Since the opening diameter of the nut 20 is slightly larger than the diameter of the needle core rod 10 , the nut 20 can be fitted over the needle core rod 10 . The needle core rod 10 has a retainer portion 10 d with a larger diameter than the opening diameter of the nut 20 . The retaining portion 10d prevents the needle core rod 10 from coming off the nut 20 screwed to the valve body.

When assembling the needle 100, the nut 20 must be externally inserted at a predetermined position between the retaining portion 10d of the needle core rod 10 and the knob 70. As shown in FIG. Since the diameter of the retaining portion 10d is larger than the opening diameter of the nut 20, the nut 20 cannot be externally inserted to a predetermined position beyond the retaining portion 10d. On the other hand, the diameter of knob 70 is larger than the opening diameter of nut 20 . Therefore, before attaching the knob 70 to the needle core rod 10 , the nut 20 is externally inserted to a predetermined position on the needle core rod 10 , and then the knob 70 is attached to the needle core rod 10 . The knob 70 is attached by screwing the knob 70 onto the needle core rod 10 and then fixing the knob 70 using a knob fixing nut 80 . The knob fixing nut 80 is fixed to the needle core rod 10 by soldering, brazing, or the like so as not to loosen due to vibration of the internal combustion engine.

The conventional needle 100 has the following problems.
In other words, manufacturing the needle 100 required parts such as the needle core rod 10, the O-ring 60, the nut 20, the knob 70, and the knob fixing nut 80, requiring a large number of parts. Furthermore, when manufacturing the needle 100, the knob 70 and the knob fixing nut 80 are screwed onto the needle core rod 10, the knob fixing nut 80 is tightened, and then the knob fixing nut 80 is soldered or brazed to the needle core rod 10. It required a lot of work man-hours to fix it with etc.

In addition, since the needle core rod 10 has screw play between itself and the knob 70, the needle core rod 10 is likely to be shaken as the knob 70 rotates, and is subjected to rotational bending stress. When the needle core rod 10 is repeatedly subjected to excessive rotational bending stress as the knob 70 rotates, the needle core rod 10 tends to break near the base of the knob 70 .

Japanese Patent Application Laid-Open No. 2003-247456 JP 2007-146791 A

SUMMARY OF THE INVENTION An object of the present invention is to provide a needle capable of reducing the number of parts and manufacturing man-hours and suppressing the occurrence of breakage of the needle core rod, and a needle valve having the needle.

In order to solve the above problems, the present invention devised the following needle. i.e.
A needle inserted into a flow hole in a valve body of a needle valve that controls the flow rate of fluid supplied to an internal combustion engine,
The needle is
a needle core rod having a distal end portion inserted into the flow hole and a base end portion exposed from the flow hole, and capable of changing an insertion length according to rotation;
a knob provided at the proximal end of the needle core rod;
a nut that has a female thread that can be screwed with the valve body and that is externally inserted on the needle core rod;
a retaining member that prevents the needle core rod from coming off from the nut;
The knob is formed integrally with the needle core rod, and the diameter of the knob is larger than the minimum diameter of the opening of the nut,
The retaining member is configured to be attachable to the needle core rod and has a diameter larger than the minimum diameter of the opening of the nut.

Such a configuration is obtained based on the following technical ideas.
In the conventional needle 100, the needle core rod 10 and the knob 70 are manufactured as separate parts. A method of attaching to the core rod 10 was adopted. In this method, since the retaining portion 10d is integrated with the needle core rod 10, the nut 20 is externally inserted from one end side of the needle core rod 10 (the tip end side in contact with the valve seat of the valve body) and moved to a predetermined position. This is done because there is a premise that even if an attempt is made to move it, it would not be possible to cross over the retaining portion 10d.

The present invention is based on the technical idea of removing this premise itself. This is a method in which the retaining member can be attached to the needle core rod so that the nut is externally inserted from one end side of the needle core rod (the tip end side in contact with the valve seat of the valve body). According to this, before attaching the retaining member to the needle core rod, the nut can be externally inserted to the predetermined position of the needle core rod, and then the retaining member can be attached to the needle core rod.

This eliminates the need to attach the knob to the needle core rod after the nut is fitted over the needle core rod at a predetermined position. Thus, it is possible to integrally form the needle core rod and the knob without manufacturing the needle core rod and the knob as separate parts. This eliminates the need for a knob fixing nut (see FIG. 4) for fixing the knob to the needle core rod. Also, the process of fixing the knob fixing nut to the needle core rod is not necessary. Therefore, the needle according to the present invention can reduce the number of parts and man-hours during manufacturing.

Furthermore, since the needle core rod and the knob are integrally formed, the rigidity of the needle core rod is high. And, of course, since there is no play in the screw between the needle core rod and the knob, it is possible to suppress rotational axis deflection and reduce rotational bending stress. This makes it difficult for the needle core rod to break near the base of the knob.

The retaining member may be composed of a C-ring made of a material different from that of the needle core rod.

Furthermore, the diameter of the proximal end of the needle core rod may be larger than the maximum diameter of the distal end. This makes it more difficult for the needle core rod to break near the base of the knob.

A needle valve according to the present invention includes the needle and the valve body described above.

1 is an exploded view showing one embodiment of a needle according to the present invention; FIG. (a) Cross-sectional view and (b) side view showing one embodiment of a needle valve The figure which shows another embodiment of a needle core rod Exploded view showing an example of a conventional needle

EMBODIMENT OF THE INVENTION Hereinafter, embodiment in the needle and needle valve of this invention is described, referring drawings. In each drawing, the dimensional ratio of the drawing and the actual dimensional ratio do not necessarily match, and the dimensional ratio between the drawings does not necessarily match.

FIG. 1 shows an exploded view of one embodiment of the needle of the present invention. FIG. 2 shows an embodiment of a needle valve having the needle and valve body of FIG. 1, (a) showing a cross-sectional view and (b) showing a side view.
The needle valve 8 is used to control the flow rate of a fluid such as fuel supplied to an internal combustion engine such as an engine for agricultural equipment and machinery. Needle valve 8 includes valve body 3 and needle 7 . The valve body 3 includes an inflow pipe 3i, an inflow pipe fixing portion 3b, a body attachment male thread portion 3a, and a nut attachment male thread portion 3c. The inflow pipe 3i includes an inflow path 3f for fluid therein. The inflow pipe fixing portion 3b is a portion to which the inflow pipe 3i is fixed, and the outside of the inflow pipe fixing portion 3b may have a grippable shape (for example, a hexagonal prism shape). The body-mounting male screw portion 3a is a portion for supporting and fixing the valve body 3 to another member. The nut attachment male threaded portion 3c is a portion that is screwed into the female threaded portion 2a of the nut 2. As shown in FIG. A communication hole 3e is formed across the interiors of the inflow pipe fixing portion 3b, the main body attachment male thread portion 3a, and the nut attachment male thread portion 3c. The through hole 3e is a region into which the needle 7 is inserted. The body-mounting male threaded portion 3a has therein a fluid outlet 3o and a valve seat 3d.

The needle 7 has a needle core rod 1 , a nut 2 externally inserted on the needle core rod 1 , a retaining member 5 and an O-ring 6 . The retaining member 5 prevents the needle core rod 1 from coming off from the nut 2. - 特許庁The O-ring 6 is fitted over the needle core rod 1 and prevents leakage of fluid from the inside of the needle valve 8 . The needle core rod 1 has a distal end portion 1a inserted into the communication hole 3e and a proximal end portion 1e exposed from the communication hole 3e. Between the distal end portion 1a and the proximal end portion 1e of the needle core rod 1, a core rod male thread portion 1b, an annular O-ring groove 1c, and a retaining member are provided from the distal end portion 1a toward the proximal end portion 1e. An annular fitting groove 1d for fitting is provided. The tip of tip portion 1a is conical. A knob 1f is provided on the proximal end 1e.

The needle core rod 1 is rotated by the operator turning the knob 1f. The needle core rod 1 has a core rod male threaded portion 1b, and the core rod male threaded portion 1b is screwed with the body female threaded portion 3g of the valve body 3. As shown in FIG. As a result, the insertion length of the needle core rod 1 into the valve body 3 can be changed according to the rotation of the needle core rod 1 . When the needle core rod 1 is deeply inserted into the valve body 3, the gap between the tip portion 1a and the valve seat 3d narrows, and the flow rate of the fluid passing through the gap decreases. When the valve is inserted most deeply, the tip of the tip portion 1a comes into contact with the valve seat 3d of the valve body 3 and the fluid does not flow. When the knob 1f is rotated to widen the gap between the tip of the tip portion 1a and the valve seat 3d, the flow rate of the fluid passing through the gap increases.

The nut 2 has an internally threaded portion 2a and an inner flange 2b therein. The female threaded portion 2a is formed at one axial end of the nut, and the inner flange 2b is formed at the other axial end of the nut. The inner diameter of the inner flange 2b defines the minimum diameter of the nut opening. The outside of the nut 2 may have a shape (for example, a hexagonal prism shape) that facilitates rotation of the nut 2 . The female threaded portion 2a is screwed into the nut-mounting male threaded portion 3c of the valve body 3. As shown in FIG. The knob 1f is formed in a size that allows an operator to turn it around, and the diameter of the knob 1f is larger than the diameter of the inner flange 2b. The nut 2 is externally inserted at a predetermined position on the needle core rod 1 . The predetermined position is a position where the inner flange 2b of the nut 2 is arranged between the fitting groove 1d and the knob 1f. After that, the retaining member 5 is attached to the fitting groove 1 d of the needle core rod 1 .

The diameter of the retaining member 5 is larger than the inner diameter of the inner flange 2 b that defines the minimum diameter of the opening of the nut 2 . Therefore, when the needle core rod 1 tries to come off from the nut 2, the retaining member 5 engages the inner flange 2b, thereby preventing the needle core rod 1 from coming off. Further, the needle core rod 1 has an annular O-ring groove 1c, and an O-ring 6 is fitted in the O-ring groove 1c. Since the O-ring 6 is arranged so as to seal the gap between the needle core rod 1 and the O-ring accommodating portion 3h of the valve body 3, leakage of fluid from this gap is prevented.

As a result, if the nut 2 is screwed onto the nut mounting male threaded portion 3c of the valve body 3, even if the knob 1f is turned until the male threaded portion 1b of the shaft and the female threaded portion 3g of the main body are unscrewed, , the O-ring 6 is not pulled out from the O-ring accommodating portion 3h. Therefore, the operator can turn the knob 1f without worrying about leakage of fluid (mostly combustible fluid such as fuel) due to excessive withdrawal of the needle core rod 1.

During maintenance and inspection of the needle 7 or replacement of the needle 7, the nut 2 is loosened to unscrew the nut mounting male threaded portion 3c of the valve body 3, and the needle core rod 1 is pulled out by turning the knob 1f in the direction of pulling out the core rod. The needle 7 can be removed from the valve body 3 by unscrewing the male threaded portion 1b and the body female threaded portion 3g.

The knob 1f is formed integrally with the needle core rod 1. As shown in FIG. Here, the expression that the knob 1f is integrally formed with the needle core rod 1 means that the knob 1f and the needle core rod 1 are formed as one member from one lump of the same material. Examples of such a forming method include a method of cutting with a lathe or the like, casting, forging, resin molding, and forming with a 3D printer. The knob 1f and the needle core rod 1 are not bonded or mechanically joined.

The retaining member 5 is a separate member from the needle core rod 1 and is configured to be attachable to the needle core rod 1 . The retaining member 5 is attached so as to be externally fitted into the fitting groove 1d of the needle core rod 1. As shown in FIG. Further, the retainer member 5 may be configured to be attachable to and detachable from the needle core rod 1 . In the detachable configuration, only the retaining member 5 can be replaced when the retaining member 5 is deteriorated or damaged. The needle core rod 1 is preferably made of metal. A C-ring made of a material different from that of the needle core rod 1 may be used as the retaining member 5 . Since the C ring is formed in a single piece in the circumferential direction, it can be easily expanded in diameter and easily attached to the needle core rod 1 .

Various materials can be used for the material of the retaining member 5 . Since the needle valve 8 itself is arranged near the internal combustion engine, it is preferable to use a material having a heat resistance temperature of 70° C. or higher for the retainer member 5 . Resin is preferably used as the material of the retaining member 5, and for example, polyacetal resin such as polyoxymethylene (POM) may be used. POM is excellent in mechanical strength and chemical thermal properties (heat resistant temperature is 80 to 100° C.) and has good dimensional stability. In addition, since it has appropriate flexibility, it is possible to attach or detach the retaining member 5 from the groove without damaging it. Metal such as stainless steel or rubber may be used instead of resin.

When a material that can be elastically deformed is used for the retaining member 5, not only the method of attaching the retaining member 5 to the fitting groove 1d after the nut 2 is externally inserted onto the needle core rod 1, but also the method of attaching the needle core rod 1 first. By attaching the retaining member 5 to the fitting groove 1d and pressing the nut 2 so as to be screwed in, the retaining member 5 is elastically deformed, and the nut 2 is moved to a predetermined position (the inner flange 2b of the nut 2 is aligned with the fitting groove 1d). position between the knobs 1f).

FIG. 3 shows another embodiment of the needle core rod.
The needle of another embodiment is the same as the previous embodiment except that the shape of the needle core is different. In the needle core rod 4 of another embodiment, the diameter of the proximal end portion 4e of the needle core rod 4 is larger than the maximum diameter of the distal end portion 4a. This increases the rigidity by increasing the thickness of the proximal end portion 4e of the needle core rod 4, which is the portion where the needle core rod 4 is likely to break.

Since the O-ring 6 is a sealing member that is attached to a sliding portion and is in contact with a fluid such as fuel, the O-ring 6 is made of a material that is excellent in mechanical properties such as wear resistance, heat resistance, and corrosion resistance to fluids. is preferred.

The fluid supplied to the internal combustion engine is typically one fluid made of liquid fuel, but it is not limited to one fluid and may be a mixture of two or more fluids. For example, it may be a two-fluid mixture of liquid fuel and air. Regarding flow rate control, in the case of one fluid, the intention is to adjust the flow rate of the entire fluid to be increased or decreased, but in the case of two or more fluids, the adjustment is to increase or decrease the flow rate of the entire fluid. Alternatively, it may be intended to adjust the flow rate ratio between each of the fluids that make up the two fluids. For example, the needle valve may be used as a fuel-only flow control valve, or as a fuel-air mixture ratio regulator in a fuel vaporizer.

The present invention is by no means limited to the above-described embodiments, and various improvements and modifications are possible without departing from the scope of the present invention.

Reference Signs List 1, 4 Needle core rod 1a Front end 1e Base end 1f Knob 2 Nut 2a Internal thread 3 Valve body 5 Retaining member 6 O-ring 7 Needle 8 Needle valve

Claims (4)

A needle inserted into a flow hole in a valve body of a needle valve that controls the flow rate of fluid supplied to an internal combustion engine,
The needle is
a needle core rod having a distal end portion inserted into the flow hole and a base end portion exposed from the flow hole, and capable of changing an insertion length according to rotation;
a knob provided at the proximal end of the needle core rod;
a nut that has a female thread that can be screwed with the valve body and that is externally inserted on the needle core rod;
a retaining member that prevents the needle core rod from coming off from the nut;
The knob is integrally formed with the needle core rod, and the diameter of the knob is larger than the minimum diameter of the opening of the nut,
The retaining member is configured to be attachable so as to be fitted into an annular fitting groove provided in the needle core rod, and has a diameter larger than the minimum diameter of the opening of the nut. needle. 2. The needle according to claim 1, wherein said retaining member is composed of a C-ring made of a material different from that of said needle core rod. 3. The needle according to claim 1 or 2, wherein the diameter of the proximal end of the needle mandrel is larger than the maximum diameter of the distal end. A needle valve comprising the needle according to any one of claims 1 to 3 and the valve body.

Images