JPH11237044A - Discharge ignition type gas igniter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain ignition performance, and at the same time to simplify the shape of a nozzle tip by allowing a square-tube-shaped nozzle tip to project at the tip of the circular emission port of an emission nozzle by a specified amount, and by setting the ratio between the main flow opening area of the inner hole and the flow-dividing opening area of the outer-periphery part of the nozzle tip in a specified range. SOLUTION: A gas passage 11 is formed at the center part of an emission nozzle 10, a circular emission port 12 is opened at a tip part, and the lower end part of a nozzle tip 20 is allowed to project by a specific amount of L for fitting to the emission port 12. Then, the shape of the nozzle tip 20 is formed into a square-tube shape, a square hole 21 is formed through the inside, and the flow-dividing ratio between the opening area of a main flow emission part (the sectional area of the inner hole 21) and the opening area of the dividing- flow emission part of an outer-periphery part (the sum of the sectional area of a void 25) is set to 10:(2.5-5.3) according to the shape modification of the thickness of the like of the nozzle tip 20, thus maintaining ignition performance and at the same time simplifying the shape of the nozzle tip 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge ignition type gas igniter for igniting a discharge gas such as a lighter, an ignition rod or the like by discharge of electric energy, and more particularly to a structure of a nozzle portion for discharging a gas.

[0002]

2. Description of the Related Art Conventionally, in a discharge ignition type gas igniter such as a piezoelectric gas lighter or an ignition rod, a part of a gas ejected from an ejection nozzle is diffused to improve a mixing property with air. It is possible to ignite even a little electric energy,
The ignitability by the discharge spark is improved.

[0003] Specifically, in a discharge ignition type gas igniter,
For example, a high voltage is generated by impacting a piezoelectric element, and the ejected gas is ignited by the discharge energy.However, at a high flow velocity in the mainstream portion of the gas, the ignitability due to the discharge ignition is low. In this case, the diffusion gas and the air are sufficiently mixed by a divergent gas having a slow flow rate in a portion where the gas passes, thereby improving the ignitability.

As described above, in order to improve the ignitability, in addition to the ejection of the mainstream gas for forming the main portion of the combustion flame, an ejection nozzle provided with a structure for ejecting a divided gas at the tip end portion Have been proposed.

One example of the structure of the tip of the jet nozzle is to machine the nozzle tip or assemble an injection port part, branch off the gas jet passage at the nozzle tip, and make auxiliary jets around the main jet port with gaps or grooves. There is a structure in which an outlet is opened and a small amount of gas is ejected.However, since it is necessary to form a complicated shape to make gas diffusion uniform, precision processing of metal, precision maintenance of precision processed parts, precision There is a problem in that production takes time due to an increase in the number of broken tools for processing and the like. There is also a problem that the cost and the cost are increased due to the large number of processing steps.

[0006] Further, there is also known a device in which a nozzle tip formed by a coil or a nozzle tip having a multi-slotted groove formed on the outer periphery is attached to the ejection outlet at the tip of the ejection nozzle, but this also has the same problem as described above. have. In particular, in a smoking article lighter, the inner diameter of the ejection port at the tip of the ejection nozzle is as small as about 1 mm, and it is difficult to perform fine processing on the outer periphery of the nozzle tip mounted on this portion.

[0007]

SUMMARY OF THE INVENTION In view of the above,
In the present invention, with respect to disposing a nozzle tip serving as one of the discharge electrodes at the tip of the ejection nozzle, the shape of the nozzle tip is simplified while maintaining the ignition performance, thereby facilitating the production and reducing the cost. is there.

[0008] The nozzle tip serves as a diffusing component. The nozzle tip diffuses the gas ejected from the ejection port at the tip of the ejection nozzle near the ejection port to ignite even a small amount of electric energy. A small amount of gas is ejected from the outer periphery of the chip to diffuse the gas around the nozzle. The diffused gas mixes with the air and can be ignited with little electrical energy when optimal conditions are obtained for combustion. The ignited flame instantaneously propagates to the central gas having a high flow velocity, and can ignite the entire gas ejected from the nozzle. The present invention has focused on the point that if the gas diffusion can be maintained in an appropriate state, good ignition performance can be ensured even with a simplified component shape.

[0009]

According to a first aspect of the present invention, there is provided a discharge ignition type gas igniter in which a nozzle tip serving also as one of discharge electrodes is provided at a tip of an ejection nozzle for ejecting gas. The shape of the tip is a rectangular cylinder, and the nozzle tip is fitted by protruding a predetermined amount at the tip of the circular ejection port of the ejection nozzle, and the main flow opening area of the inner hole of the nozzle tip and the diverting opening area of the outer peripheral portion thereof Is 1
0: in the range of 2.5 to 5.3.

The ratio of the area of the mainstream opening of the inner hole of the nozzle tip to the area of the branching opening at the outer peripheral portion is from 10: 3.3 to
A range of 5.0 is more preferred.

Further, the amount of protrusion of the nozzle tip from the opening of the ejection nozzle is preferably in the range of 1.7 to 2.6 mm, and more preferably in the range of 1.8 to 2.3 mm.

[0012]

According to the present invention as described above, a nozzle tip having a quadrangular cylindrical shape is fitted to the tip end of the circular ejection port of the ejection nozzle so as to protrude by a predetermined amount, and the inner hole of the nozzle tip is formed. The ratio of the main flow opening area to the diverging opening area at the outer periphery is 1
By setting the ratio to 0: 2.5 to 5.3, the mixed state of the diverted gas with air can be made appropriate, and the diffusion gas can be present in the discharge portion to maintain good ignition performance while maintaining good ignition performance. Due to the simplification of the shape, the production of the nozzle tip can be easily performed, and the cost can be reduced.

Further, the ratio of the area of the mainstream opening of the inner hole of the nozzle tip to the area of the branching opening at the outer peripheral portion is 10: 3.3-5.
When it is in the range of 0, better ignition performance can be secured.
Further, the protrusion amount of the nozzle tip from the opening at the tip of the ejection nozzle is 1.7 to 2.6 mm, preferably 1.8 to 2.3 mm.
When it is set in the range of mm, the diverted gas can be kept in a more favorable mixed state and good ignition performance can be secured.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIG. 1 is a perspective view of a nozzle tip of a gas lighter which is an example of a discharge ignition type gas igniter of this embodiment, FIG. 2 is a longitudinal sectional view thereof, FIG. 3 is an enlarged plan view, and FIG. 4 is a perspective view of a nozzle tip. is there.

Although the entire structure of the gas igniter is not shown, the gas igniter is provided with an ejection nozzle 10 for ejecting a fuel gas from a fuel tank for storing the fuel gas, and a gas passage 11 (FIG. 2) is formed, and a circular ejection port 12 is opened at the tip, and the lower end of the nozzle tip 20 is fitted to the ejection port 12.

The nozzle tip 20 has a square tubular shape, and has a square inner hole 21 penetrating therethrough. The nozzle tip 20 has four corners on the outer circumference formed on an arc surface 20a corresponding to the inner diameter of the ejection port 12 of the ejection nozzle 10, and this arc surface 20a is pressed against and fitted to the inner surface of the ejection port 12, The lower end of the tip 20 is a step 12a below the ejection port 12.
, The upper portion of the nozzle tip 20 protrudes from the tip of the ejection nozzle 10 by a predetermined amount of projection L (protrusion margin).

The gas flowing through the gas passage 11 of the ejection nozzle 10 includes a mainstream gas A ejected through the inner hole 21 (mainstream ejection portion) of the nozzle tip 20 and a gas inside the ejection nozzle 10 on the outer periphery of the nozzle tip 20. The gas is separated and jetted from the divided gas B jetted from four arcuate gaps 25 (split jet portions) formed between the periphery and the arc.

The nozzle tip 20 also serves as one of the discharge electrodes for performing a discharge for ignition, and is made of metal, conductive plastic, rubber, or the like, and is not shown near the nozzle tip 20. A discharge electrode is provided, and a discharge voltage generated from the piezoelectric device is applied between the nozzle tip 20 (jet nozzle 10) and the discharge electrode, and the discharge spark ignites the jet gas.

A flame having a predetermined length is formed by the mainstream gas A ejected from the inner hole 21 of the nozzle tip 20, and the nozzle tip
The diverted gas B ejected from the gap 25 on the outer circumference of the nozzle 20 is mixed around the air appropriately, is present around the tip of the nozzle tip 20, and is ignited by discharge to the nozzle tip 20. It has a structure in which ignition is possible even with a small energy due to the discharge of the gas to enhance the ignitability.

By changing the shape of the nozzle tip 20 such as the wall thickness, the opening area of the main flow jetting section (cross-sectional area of the inner hole 21) and the opening area of the branch jetting section at the outer peripheral portion (total cross-sectional area of the gap 25) are obtained. (Referred to as a diversion ratio) from 10: 2.5 to 5.
3 is set. This split ratio is 10:
More preferably, it is set in the range of 3.3 to 5.0.

FIG. 5 shows the results of an experiment for determining the appropriate range of the above-mentioned split ratio. In this experiment, the inner diameter of the jet port 12 was 0.98 mm
A nozzle tip 20 having a changed shape such as wall thickness is fitted to the jet nozzle 10 of φ to change the shunt ratio, and a firing rate is measured when discharge ignition is performed while jetting gas. It is. The ambient temperature is 23 ° C.

From the results shown in FIG. 5, it is found that the ignition ratio is as high as, for example, 85% or more, and the shunt ratio is 10: 2.5.
To 5.3, and in order to obtain a particularly high ignition rate, the split ratio is preferably in the range of 10: 3.3 to 5.0.

If the diverting ratio is lower than the above range, that is, if the diverting gas is small, the diffusing gas is drawn into the mainstream gas while the diverting gas cannot be diffused completely, and the mixed region of air and gas becomes narrower, and the ignitability increases. Decrease. Also, if the split ratio is larger than the above range, that is, if the split gas is large, the split gas is not drawn into the mainstream gas, and the fuel gas having a higher specific gravity than air flows downward away from the main flow, and The ignition rate is extremely reduced due to the concentration being too high, and the form of the flame becomes unsuitable due to the decrease in the mainstream gas.

The jet nozzle 10 of the nozzle tip 20
The amount of protrusion L (protruding dimension) from the opening at the front end is 1.7 to
The range of 2.6 mm is preferable, and more preferably, 1.8 to 1.8 mm.
The range is 2.3 mm. The ejection port 12 of the ejection nozzle 10
Has an inner diameter of 0.98 mmφ.

FIG. 6 shows the results of an experiment in which the appropriate range of the protrusion amount L was obtained. In this experiment, the inner diameter of the ejection port 12 was 0.98.
The protrusion rate L was changed by fitting nozzle tips 20 having different lengths to the jet nozzle 10 of mmφ, and the ignition rate when discharging ignition was performed while jetting gas was measured. The ambient temperature is 23 ° C.

From the results shown in FIG. 6, it is preferable that the protrusion amount L is in the range of 1.7 to 2.6 mm in order to obtain a high ignition rate, and particularly in order to obtain a high ignition rate, the protrusion amount L is 1 mm. .8
It is preferably in the range of ~ 2.3 mm.

If the protruding amount L of the nozzle tip 20 is shorter than the above range, the distance between the mainstream gas and the diverted gas is short, the diverted gas is not sufficiently diffused, and the optimal mixing region with air becomes narrower, and ignition occurs. The rate drops. In addition, the protrusion amount L exceeds the above range.
Is large, the mainstream gas and the diverted gas are separated from each other, and the effect of drawing the diverted gas by the mainstream gas cannot be obtained, and the gas having a high specific gravity flows downward, and the ignitability is reduced.

By setting the shunt ratio and the protruding amount in the appropriate ranges as described above, the diffusion gas mixes with air near the discharge portion, and the electric discharge passes therethrough, resulting in good ignition. The property is obtained.

As described above, even if the shape is simplified to a square shape to facilitate its manufacture, good ignitability can be ensured by setting the shunt ratio in an appropriate range. Absent.

Although the nozzle tip 20 in the above embodiment is also provided with the inner hole 21 in a square shape, the nozzle tip 20 is formed into a shape such as a circular hole that can be easily processed as long as a predetermined branch ratio can be obtained. Can be changed. For example, a square pillar pipe can be formed at low cost by extrusion.

[Brief description of the drawings]

FIG. 1 is a perspective view of a nozzle tip of a gas lighter according to one embodiment of a discharge ignition type gas igniter of the present invention.

FIG. 2 is a longitudinal sectional view of FIG.

FIG. 3 is an enlarged plan view of FIG. 2;

FIG. 4 is a perspective view of a nozzle tip.

FIG. 5 is a graph showing an ignition rate when a branch ratio of a lighter equipped with a square nozzle tip is changed.

FIG. 6 is a graph showing an ignition rate when a projection amount of a lighter equipped with a square nozzle tip is changed.

[Explanation of symbols]

 10 Jet nozzle 11 Gas passage 12 Jet outlet 20 Nozzle tip 21 Inner hole (main stream jet section) 25 Air gap (shunt jet section) A Main stream gas B Split gas L Projecting amount (protruding dimension)

Claims (4)

[Claims] 1. A discharge ignition type gas igniter in which a nozzle tip serving as one of discharge electrodes is disposed at a tip of an ejection nozzle for ejecting a gas, wherein the nozzle tip has a square cylindrical shape, and The nozzle tip is fitted to the tip of the circular ejection port so as to protrude by a predetermined amount and has a ratio of a main flow opening area of an inner hole of the nozzle tip to a branch opening area of an outer peripheral portion of 10: 2.5 to 5.3.
A discharge ignition type gas igniter characterized by the following range. 2. The ratio of the area of the mainstream opening of the inner hole of the nozzle tip to the area of the branching opening at the outer peripheral portion is from 10: 3.3 to 5.0.
The discharge ignition type gas igniter according to claim 1, wherein the value is in a range of 0. 3. The discharge ignition type gas igniter according to claim 1, wherein an amount of protrusion of the nozzle tip from a tip end opening of the ejection nozzle is in a range of 1.7 to 2.6 mm. 4. The discharge ignition type gas igniter according to claim 1, wherein an amount of protrusion of the nozzle tip from a tip end opening of the ejection nozzle is in a range of 1.8 to 2.3 mm.