JP2020056390A - Needle and needle valve - Google Patents

Abstract

To provide a needle which can reduce the number of part items, and man-hours at manufacturing, and can suppress the occurrence of the breakage of a needle core rod.SOLUTION: A needle 7 inserted into a circulation hole 3e of a valve main body 3 of a needle valve 8 for controlling a flow rate of fluid supplied to an internal combustion engine comprises: a needle core rod 1 having a tip part 1a inserted into the circulation hole 3e, and a base end part 1e exposed from the circulation hole 3e, and capable of changing an insertion length according to rotation; a knob 1f arranged at the base end part 1e of the needle core rod 1; a nut 2 having a female screw part 2a which can be screwed to the valve main body 3, and is externally fit to the needle core rod 1; and a retention member 5 for preventing the come-off of the needle core rod 1 from the nut 2. The knob 1f is formed at the needle core rod 1 integrally therewith, a diameter of the knob 1f is larger than a minimum diameter of an opening of the nut 2; and the retention member 5 is constituted so as to be attachable to the needle core rod 1, and has a diameter larger than the minimum diameter of the opening of the nut 2.SELECTED DRAWING: Figure 2

Description

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

  Conventionally, it is known to use a needle valve for controlling the flow rate of a fluid supplied to an internal combustion engine. The needle valve is a kind of fluid flow control valve and has a valve body and a needle. Then, 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 has a needle core rod 10 inserted into a flow hole of a valve body (not shown), an O-ring 60 externally inserted into the needle core rod 10 to prevent leakage of fluid, and the needle core rod 10 from falling out of the valve body. , A knob 70 for adjusting the insertion length of the needle core rod 10 by rotating, and a knob fixing nut 80 for fixing the knob 70 to the needle core rod 10.

  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 and adjusting the insertion length of the needle core rod 10. The nut 20 is screwed into the valve body. Since the opening diameter of the nut 20 is slightly larger than the diameter of the needle core 10, the nut 20 can be extrapolated to the needle core 10. The needle core rod 10 has a retaining portion 10 d having a diameter larger 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 extrapolated to a predetermined position between the stopper 70d of the needle core rod 10 and the knob 70. Since the diameter of the retaining portion 10d is larger than the opening diameter of the nut 20, the nut 20 cannot be extrapolated to a predetermined position beyond the retaining portion 10d. On the other hand, the diameter of the knob 70 is larger than the opening diameter of the nut 20. Therefore, before attaching the knob 70 to the needle core 10, the nut 20 is extrapolated to a predetermined position of the needle core 10, and then the knob 70 is attached to the needle core 10. The knob 70 is attached by screwing the knob 70 to the needle core rod 10 and then fixing the knob 70 using the knob fixing nut 80. The knob fixing nut 80 is fixed to the needle core rod 10 by soldering, brazing, or the like so that the knob fixing nut 80 is not loosened by receiving vibration of the internal combustion engine.

The conventional needle 100 has the following problems.
That is, the manufacture of the needle 100 required the components of the needle core 10, the O-ring 60, the nut 20, the knob 70, and the knob fixing nut 80, and required many parts. Further, at the time of manufacturing the needle 100, the knob 70 and the knob fixing nut 80 are screwed into 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 took many man-hours to fix it.

  In addition, since the needle core 10 has a play of a screw between the needle 70 and the knob 70, the needle core 10 is liable to cause shaft deflection due to the rotation of the knob 70, and receives rotational bending stress. If the needle core 10 is repeatedly subjected to excessive rotational bending stress with the rotation of the knob 70, there is a problem that the needle core 10 is likely to be broken near the root of the knob 70.

JP 2003-247456 A JP 2007-146791 A

  An object of the present invention is to provide a needle that can reduce the number of parts and the number of man-hours at the time of manufacturing, and can also suppress the occurrence of breakage of a needle core rod, and a needle valve provided with the needle.

The present invention has devised the following needle in order to solve the above problems. That is,
A needle inserted into a flow hole of a valve body of a needle valve for controlling a flow rate of a fluid supplied to the internal combustion engine,
The needle is
A needle core rod having a distal end inserted into the communication hole, and a base end exposed from the communication hole, and capable of changing an insertion length in accordance with rotation;
A knob provided at a base end of the needle core rod,
A nut having a female screw portion that can be screwed with the valve body, and a nut externally inserted into the needle core rod;
Preventing the needle core rod from coming off the nut, comprising a retaining member,
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 a minimum diameter of the opening of the nut.

Such a configuration is obtained based on the following technical idea.
In the conventional needle 100, the needle core rod 10 and the knob 70 are manufactured as separate parts, and after the nut 20 is extrapolated to a predetermined position of the needle core rod 10, the knob 70 is needled using the knob fixing nut 80. The 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 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 it was not possible to go over the retaining portion 10d even if it was attempted to do so.

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

  This eliminates the need to attach the knob to the needle core bar after extrapolating the nut to a predetermined position on the needle core bar. Thus, the needle core and the knob can be integrally formed without manufacturing the needle core 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, a thread cutting step for screwing the needle core rod to the knob and the knob fixing nut, a step of tightening the knob fixing nut, Further, the step of fixing the knob fixing nut to the needle core rod becomes unnecessary. Therefore, the needle according to the present invention can reduce the number of parts and the number of work steps during manufacturing.

  Further, since the needle core and the knob are integrally formed, the rigidity of the needle core is high. And, of course, since there is no play of the screw between the needle core bar and the knob, the rotation shaft blur can be suppressed and the rotation bending stress can be reduced. This makes it difficult for the needle core bar to break near the root of the knob.

  The retaining member may be constituted by a C-ring formed of a material different from that of the needle core bar.

  Further, 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 bar to break near the root of the knob.

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

Exploded view showing one embodiment of the needle according to the present invention. (A) sectional view and (b) side view which show 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

  Hereinafter, embodiments of a needle and a needle valve of the present invention will be described with reference to the drawings. In each of the drawings, the dimensional ratios of the drawings do not always match the actual dimensional ratios, and the dimensional ratios of the drawings do not always match.

FIG. 1 shows an exploded view of one embodiment of the needle according to the present invention. 2A and 2B are diagrams illustrating an embodiment of a needle valve having the needle and the valve body of FIG. 1, wherein FIG. 2A illustrates a cross-sectional view, and FIG. 2B illustrates a side view.
The needle valve 8 is used for controlling a flow rate of a fluid such as a fuel supplied to an internal combustion engine such as an agricultural machine tool or an agricultural machine engine. The needle valve 8 includes the valve body 3 and the needle 7. The valve main body 3 includes an inflow pipe 3i, an inflow pipe fixing part 3b, a male thread part 3a for attaching the main body, and a male thread part 3c for attaching a nut. The inflow pipe 3i has a fluid inflow passage 3f therein. The inflow pipe fixing part 3b is a part to which the inflow pipe 3i is fixed, and the outside of the inflow pipe fixing part 3b may have a grippable shape (for example, a hexagonal prism shape). The main body mounting male screw portion 3a is a portion for supporting and fixing the valve main body 3 to another member. The nut mounting male screw portion 3c is a portion screwed to the female screw portion 2a of the nut 2. A flow hole 3e is formed across the inside of the inflow pipe fixing portion 3b, the main body mounting male screw portion 3a, and the nut mounting male screw portion 3c. The flow hole 3e is an area where the needle 7 is inserted. The main body mounting external thread portion 3a has a fluid outlet 3o and a valve seat 3d therein.

  The needle 7 has a needle core 1, a nut 2 externally inserted into the needle core 1, a retaining member 5, and an O-ring 6. The retaining member 5 prevents the needle core 1 from coming off the nut 2. The O-ring 6 is externally inserted into the needle core rod 1 and prevents leakage of fluid from inside the needle valve 8. The needle core bar 1 has a distal end 1a inserted into the flow hole 3e, and a proximal end 1e exposed from the flow hole 3e. Between the distal end portion 1a and the proximal end portion 1e of the needle core rod 1, from the distal end portion 1a toward the proximal end portion 1e, there is provided a male external thread portion 1b, an annular O-ring groove 1c, and a retaining member. An annular fitting groove 1d to be fitted is provided. The tip of the tip portion 1a has a conical shape. The base 1e is provided with a knob 1f.

  When the operator pulls the knob 1f, the needle core rod 1 is rotated. The needle rod 1 has a rod external thread portion 1b, and the rod external thread portion 1b is screwed with the female internal thread portion 3g of the valve main body 3. Thereby, the insertion length of the needle core 1 into the valve body 3 can be changed according to the rotation of the needle core 1. When the needle core rod 1 is inserted deeply into the valve body 3, the gap between the distal end portion 1a and the valve seat 3d becomes narrow, and the flow rate of the fluid passing through the gap decreases. When it 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 no fluid flows. When the knob 1f is rotated to enlarge the gap between the tip of the tip 1a and the valve seat 3d, the flow rate of the fluid passing through the gap increases.

  The nut 2 has a female screw portion 2a and an inner flange 2b inside. The female screw portion 2a is formed on one end side in the nut axial direction, and the inner flange 2b is formed on the other end side in the nut axial direction. 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 makes the nut 2 easy to rotate. The female screw portion 2a is screwed to the nut mounting male screw portion 3c of the valve body 3. The knob 1f is formed in a size that can be picked up by an operator, and the diameter of the knob 1f is larger than the diameter of the inner flange 2b. The nut 2 is extrapolated to a predetermined position of the needle core 1. The predetermined position is a position where the inner flange 2b of the nut 2 is disposed between the fitting groove 1d and the knob 1f. Thereafter, the retaining member 5 is attached to the fitting groove 1d of the needle core bar 1.

  The diameter of the retaining member 5 is larger than the inner diameter of the inner flange 2b that defines the minimum diameter of the opening of the nut 2. Therefore, when the needle core rod 1 tries to slip out of the nut 2, the retaining member 5 engages with the inner flange 2b, thereby preventing the needle core rod 1 from slipping out. Further, the needle core 1 has an annular O-ring groove 1c, and the O-ring 6 is fitted into 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.

  Thus, if the nut 2 is screwed into the nut mounting male screw portion 3c of the valve body 3, even if the knob 1f is turned until the screw between the core rod male screw portion 1b and the main body female screw portion 3g is released. , O-ring 6 is not pulled out of O-ring housing 3h. Therefore, the operator can turn the knob 1f without worrying about leakage of the fluid (often a combustible fluid such as fuel) due to excessive withdrawal of the needle core 1.

  At the time of maintenance and inspection of the needle 7 and replacement of the needle 7, the nut 2 is loosened to unscrew the nut from the male threaded portion 3 c of the valve body 3, and the knob 1 f is turned in a direction in which the needle core 1 is pulled out. The needle 7 can be removed from the valve main body 3 by unscrewing the male screw part 1b and the main body female screw part 3g.

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

  The retaining member 5 is a separate member from the needle core 1 and is configured to be attachable to the needle core 1. The retaining member 5 is attached so as to be fitted outside the fitting groove 1d of the needle core bar 1. Further, the retaining member 5 may be configured to be detachable from the needle core bar 1. When the retaining member 5 is configured to be detachable, when the retaining member 5 is deteriorated or damaged, only the retaining member 5 can be replaced. The needle core 1 is preferably made of metal. As the retaining member 5, a C-ring formed of a material different from that of the needle core 1 may be used. Since the C-ring is formed so as to be divided into one in the circumferential direction, it can be easily expanded in diameter and can be 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, the retaining member 5 is preferably made of a material having a heat-resistant temperature of 70 ° C. or higher. A resin is preferably used as the material of the retaining member 5, and for example, a polyacetal resin such as polyoxymethylene (POM) may be used. POM has excellent mechanical strength and chemical thermal properties (heat-resistant temperature is 80 to 100 ° C.), and also has good dimensional stability. Moreover, since it has moderate flexibility, the retaining member 5 can be attached to the groove or removed from the groove without being damaged. In addition to resin, metal such as stainless steel or rubber may be used.

  When a material which elastically deforms is used for the retaining member 5, not only the method of attaching the retaining member 5 to the fitting groove 1d after extrapolating the nut 2 to the needle core bar 1, but also The retaining member 5 is attached to the fitting groove 1d, and the nut 2 is pressed in such a manner that the nut 2 is screwed in, whereby 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 in (A position disposed between the knobs 1f).

FIG. 3 shows another embodiment of the needle core bar.
The needle of another embodiment is the same as the previous embodiment except that the shape of the needle core bar is different. In the needle core rod 4 of another embodiment, the diameter of the proximal end 4e of the needle core rod 4 is larger than the maximum diameter of the distal end 4a. This is to increase the thickness of the base end portion 4e of the needle core bar 4, which is a portion where the needle core bar 4 is easily broken, to increase rigidity.

  Since the O-ring 6 is a seal member attached to a sliding portion and in contact with a fluid such as fuel, the O-ring 6 is made of a material having excellent mechanical properties such as abrasion resistance, heat resistance, and corrosion resistance to a fluid. It is preferred to use

  The fluid supplied to the internal combustion engine is typically one fluid composed of liquid fuel, but is not limited to one fluid, and may be a mixed fluid of two or more types. For example, two fluids in which a liquid fuel and air are mixed may be used. Regarding flow control, in the case of one fluid, it is intended to adjust to increase or decrease the flow rate of the entire fluid, but in the case of two or more fluids, to adjust the flow rate of the entire fluid to increase or decrease In addition, the adjustment of the flow ratio between the respective fluids constituting the two fluids may be intended. For example, the needle valve may be used as a fuel-only flow control valve, or may be used as a fuel-air mixture ratio regulator in a fuel carburetor.

  The present invention is not limited to the above-described embodiment at all, and various improvements and modifications can be made without departing from the spirit of the present invention.

1, 4 ... Needle core rod 1a ... Tip 1e ... Base end 1f ... Knob 2 ... Nut 2a ... Female thread 3 ... Valve body 5 ... Retaining member 6 ... O-ring 7 ... Needle 8 ... Needle valve

Claims (4)

A needle inserted into a flow hole of a valve body of a needle valve for controlling a flow rate of a fluid supplied to the internal combustion engine,
The needle is
A needle core rod having a distal end inserted into the communication hole, and a base end exposed from the communication hole, and capable of changing an insertion length in accordance with rotation;
A knob provided at a base end of the needle core rod,
A nut having a female screw portion that can be screwed with the valve body, and a nut externally inserted into the needle core rod;
Preventing the needle core rod from coming off the nut, comprising a retaining member,
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 needle, wherein the retaining member is configured to be attachable to the needle core rod and has a diameter larger than a minimum diameter of an opening of the nut.   The needle according to claim 1, wherein the retaining member is formed of a C-ring formed of a material different from the needle core bar.   The needle according to claim 1, wherein a diameter of the proximal end of the needle core bar is larger than a maximum diameter of the distal end. A needle valve comprising the needle according to claim 1 and the valve body.

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