JP2880047B2 - Contact combustion type gas detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalytic combustion type gas detector, and more particularly, to a catalytic combustion type gas detector having improved impact resistance without deteriorating sensitivity.

[0002]

2. Description of the Related Art There are various types of gas detectors depending on the detection target, detection means, and the like.
A catalytic combustion gas detection device described in US Pat. No. 26335 is known. The present invention relates to a detection body having a detection element provided with a detection unit in the middle of a platinum wire and being stretched and fixed to one end of a pair of support pins fixed to a base, and a comparison unit in the middle of the platinum wire. And a comparison element formed by stretching and fixing the comparison element provided with the one end of a pair of support pins fixed to the base in a wire mesh.

[0003] In general, a contact combustion type gas detector is constructed by stretching a thin platinum wire, so that it has low strength against external force in a direction perpendicular to the extending direction of the platinum wire and is weak against impact. There is a big problem. Although the invention of the above publication describes that the detection unit and the comparison unit are surrounded by glass wool, such a configuration has nothing to do with the improvement in impact resistance.

[0004] By the way, platinum wires have become thinner with the improvement of sensitivity. Recently, thin wires having a wire diameter of about 10 to 30 µm have been used. However, in order to solve the above-mentioned problems, glass wool is used. It seems that a contact-combustion gas detection device in which a belt-shaped glass wool is wound between a pair of support pins to improve impact resistance has been considered.

[0005]

As described above, in the catalytic combustion type gas detecting device described in JP-B-63-26335, the diameter of the platinum wire becomes smaller as the sensitivity is improved. Impact resistance is further reduced, and there is a possibility that the platinum wire may be cut by an impact while being carried. Further, the structure in which the belt-shaped glass wool is wound between the support pins has a problem to be solved in terms of impact resistance.

That is, of the directions orthogonal to the direction in which the platinum wire is stretched, the direction along the direction in which the support pins extend is referred to as a vertical direction, and the direction intersecting the vertical direction is referred to as a horizontal direction.
The configuration in which the belt-shaped glass wool is wound improves the impact resistance in the horizontal direction, but has extremely low impact resistance in the vertical direction.

SUMMARY OF THE INVENTION An object of the present invention is to provide a contact combustion type gas detecting device which does not lower the sensitivity and has greatly improved impact resistance.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a detection method in which a linear detecting element having a detecting portion formed in the middle thereof is stretched and fixed to a pair of support pins fixed to a base. Body, a comparison body in which a linear comparison element provided in the vicinity of the detection body and having a comparison section formed in the middle is stretched and fixed to a pair of support pins fixed to a base, and the detection body and the comparison body A contact combustion type gas detection device comprising: a gas-permeable cap attached to the base; and a buffer provided in the cap to reduce displacement of the detection unit and the comparison unit due to impact. The buffering means reduces the displacement of the detection section in the longitudinal direction in which the support pin extends, and the buffer means includes a pair of support pins on the detection body side.
A buffer member formed by winding and stretching glass fiber is
A vertical buffer body provided on both sides in the vertical direction,
The vertical buffer is to alleviate the displacement of the detection unit in the horizontal direction intersecting with the vertical direction to be alleviated ,
Glass fiber crossed over a pair of support pins on the detector side
The cushioning member formed by being wound and stretched around
The difference part is provided so as to face the detection unit from both sides in the lateral direction.
The configured lateral buffer and a pair of support pins on the side of the comparative body.
Comparison of cushioning members formed by winding and stretching glass fiber around
Longitudinal shock absorber provided on both sides in the longitudinal direction of the part
And adding glass fiber to a pair of support pins on the side of the comparative body.
A cushion member formed by being wound and stretched in a hook shape
The crossing point of the hook should be opposite the comparison part from both sides in the horizontal direction
And a lateral cushioning member provided in the above-mentioned configuration .

[0009]

According to the present invention, a lateral buffer is provided to reduce lateral displacement of the detecting element and the comparing element.
The provision of the vertical buffer for alleviating the vertical displacement can significantly improve the impact resistance without lowering the sensitivity, that is, while maintaining the high sensitivity configuration.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 is an explanatory sectional view of a main part of a first embodiment of the present invention in a front view, FIG.
FIG. 4 is an explanatory cross-sectional view of a main portion of a second embodiment of the present invention when viewed from the front.
FIG. 5 is a cross-sectional view of a principal part of the third embodiment of the present invention. FIG. 5 is a cross-sectional view of a main part of a third embodiment of the present invention. FIG. 7 is an explanatory sectional view of a main part of a fifth embodiment of the present invention, as viewed from the front, FIG. 8 is a circuit explanatory diagram of a measuring apparatus of each embodiment of the present invention, FIG. Is an explanatory diagram of sensitivity, and FIG. 11 is an explanatory diagram of a sample for comparative measurement.

A contact-combustion gas detecting device according to an embodiment of the present invention comprises a pair of support pins 12, 1 having a linear detecting element 15 having a detecting portion 16 formed in the middle thereof fixed to a base 11.
3 and a pair of support pins 22 fixed to the base 11, a linear comparison element 25 provided in proximity to the detection body 18 and provided with a comparison section 26 in the middle.
23, a cap 28 which covers the detection body 18 and the comparison body 21 and is attached to the base 11 and which allows gas to flow therethrough. And a buffer means 30 for alleviating the displacement of the comparison section 26.

The buffer means 30 includes a support pin 1
A longitudinal buffer 31 for relaxing the displacement in the vertical direction in which the two and 13 extend, and a lateral buffer 35 for relaxing the displacement in a direction intersecting the longitudinal direction. The means 30 can reduce the displacement in the vertical and horizontal directions, and as a result, it is possible to greatly improve the impact resistance while maintaining the high sensitivity configuration.

Hereinafter, each embodiment will be described in detail.
Since the other parts except the buffer means have the same configuration in each embodiment, the configuration of the parts excluding the buffer means will be described in the first embodiment, and in the other embodiments, the same parts will be described. The same reference numerals are given and the description is omitted. In other embodiments, only the buffer means will be described. In each of the embodiments, the buffer means has the same configuration on the detection body side and on the comparison body side. Therefore, only the detection body side will be described, and the description on the comparison body side will be omitted. Is indicated by adding n.

First, a first embodiment will be described with reference to FIGS. Reference numeral 11 denotes a base made of a disc-shaped insulating member. A pair of parallel support pins 12, 13 which are parallel to each other and spaced apart from each other are fixed through the base 11, and these support pins 12, 13 are fixed. Reference numeral 13 stands and extends in parallel with the central axis 11a of the base 11. A detection element 15 is stretched and fixed to one end of each of the support pins 12 and 13. The detection element 15 is made of a platinum wire having a wire diameter of 10 to 30 μm, and a coil portion is formed in the middle. An alumina catalyst carrying Pt, Rh, and Pd is attached to this coil portion to constitute a detection unit 16, and both ends of the platinum wire are fixed to one ends of the support pins 12, 13 as described above, and the detection is performed. An element 15 is stretched and supported, and the detection element 18 and the support pins 12 and 13 constitute a detection body 18.

On the other hand, a comparator 21 is provided near the detector 18. This comparator 21 is a detector 18
Similarly, the support pins 2 fixed through the base 11
A comparison element 25 is stretched and fixed to one end of each of the reference numerals 2 and 23. The comparison element 25 is formed of a platinum wire having a wire diameter similar to that of the detection element 15, and a comparison section 26 is formed by attaching an alumina carrier to a coil portion formed in the middle. The detection body 18 and the comparison body 21 are accommodated in a cap 28 made of a metal mesh which is attached to the base 11 and through which a gas to be detected can flow.

Next, the buffering means 30 of this embodiment will be described. As described above, the buffer means 30 has the same configuration as that of the detector 18 and that of the comparator 21. Therefore, only the detector 18 will be described, and the description of the comparator 21 will be omitted. I do. As described above, assuming that the extending direction of the support pins 12 and 13 is the vertical direction and the direction intersecting the vertical direction is the horizontal direction, the buffering means 30 reduces the displacement of the detection element 15 along the vertical direction. Vertical buffer 3
1 and a lateral buffer 35 for reducing the displacement in the lateral direction.

The vertical buffer 31 is formed of a buffer member made of glass wool 32, and is filled between the detecting element 15 and the comparing element 25 and the inside of the top of the cap 28.
The detection unit 16 is in pressure contact with the comparison unit 26. The filling amount is, for example, 30 to 1 glass wool per 1 cc volume.
00 mg. Then, the vertical displacement of the detection unit 16 and the comparison unit 26 is reduced from one side.

The horizontal buffer 35 is made of a band-shaped glass wool 36 formed of glass wool in a band shape.
The support pins 12 and 13 are appropriately wound around the support pins 12 and 13, respectively. In other words, one buffer member 37 and the other buffer member 38 that face each other in the lateral direction via the detection element 15 are integrally formed on the front and back sides to form the horizontal buffer 35. The horizontal buffer 35 reduces the displacement of the detection unit 16 in the horizontal direction, that is, in the direction intersecting the vertical direction. Note that, as in this embodiment, the vertical buffer 3
1 when configured in moth Rasuuru 32, good productivity can also be applied to existing catalytic combustion type gas detection apparatus. In addition, although the lateral buffer 35 is formed integrally by winding, it may be formed separately from the front and back, instead of being integrated.

Next, a second embodiment will be described with reference to FIGS. The buffer means 40 includes a vertical buffer 41,
The buffer members 41 and 45 are formed by using thread-like glass fibers 44 having a wire diameter of 50 to 100 μm formed by combining a plurality of glass fibers having a wire diameter of 10 to 20 μm. Have been.

The longitudinal buffer 41 is made of a thread-like glass fiber 44.
Is wound around the support pins 12 and 13 a plurality of times, and is fixed with, for example, an adhesive or the like, so that the pair of cushioning members 4
2, 43 are formed. And these buffer members 4
Reference numerals 2 and 43 are arranged so as to be spaced apart from each other on both sides of the detection element 15 in the vertical direction (vertical direction in FIG. 3). And, by providing the detector in the vicinity of the detector 16, displacement in the vertical direction can be reduced.

The horizontal buffer 45 is formed by winding thread-like glass fibers 44 obliquely around the support pins 12 and 13 and stretching and fixing them, and one of the buffer members 46 and 46 formed on the front and back sides of the detector 15. And a thread-like glass fiber 44 is wound diagonally so as to intersect with one of the buffer members 46 , 46, and the other buffer members 47 , 4 formed on the front and back sides of the detector 15.
7 and these cushioning members 46, 46, 4
Numerals 7 and 47 are arranged on both sides in the horizontal direction of the detection unit 16, and are configured so that the intersections 48 and 48 are opposed to the detection unit 16 to reduce the displacement in the horizontal direction. In the present embodiment, each buffer is constituted by the thread-like glass fiber 44, but the present invention is not limited to this. Also, the present embodiment
Since each buffer member is formed of the thread-like glass fiber 44, the flow of the gas to be detected is good, and a decrease in sensitivity can be suppressed.

Next, a third embodiment will be described with reference to FIG. In the present embodiment, the buffer means 50 is configured by winding the band-shaped glass wool 55 one or two times outside the buffer means 40 of the second embodiment in the horizontal direction, and the horizontal buffer function is improved. Things.

Next, a fourth embodiment will be described with reference to FIG. In this embodiment, after the belt-like glass wool 65 is wound around the support pins 12 and 13, the thread-like glass fibers 62 and 63 are wound one or two times on both sides in the vertical direction of the detection unit 16, and the buffer means 60 is wound.
It is what constituted. By closing the vertical direction of the band-shaped glass wool 65 in this way, the glass wool 65 and the thread-like glass fibers 62 and 63 constitute a vertical buffer 64. In this embodiment, since the entire detection element 15 is surrounded by the glass wool 65, the impact resistance can be greatly improved.

Next, a fifth embodiment will be described with reference to FIG. In the present embodiment, a reticulated glass fiber (cloth) 75 of about 10 to 20 mesh is placed over the support pins 12 and 13 from above the portion facing the detection unit 16 from the lateral direction.
6 is wound around the upper and lower sides of the figure with thread-like glass fibers 72 and 73 to fix the mesh-like glass fiber 75.

The pair of thread-like glass fibers 72 and 73 constitute a vertical buffer 71, and the mesh glass fiber 75 constitutes a horizontal buffer 75. Also, the buffer means 70
It is constituted by a vertical buffer 71 and a horizontal buffer 75.
ing.

In the present embodiment, the sensitivity does not decrease because the lateral buffer 75 is made of mesh glass fiber. In addition, the fixing of the reticulated glass fiber is achieved by heating the pin 1 by heating.
Means for fixing to the fibers 2 and 13 may be used, and the thread-like glass fibers 72 and 73 may not necessarily be used.

A description will be given below of the improvement in impact resistance.
FIG. 8 shows a measuring circuit 10 for measuring sensitivity, zero point displacement due to impact, and the like.
0 is a commonly used bridge circuit. Fifteen
Is a detection element, 25 is a comparison element, and 103 is a load. The zero point movement and the sensitivity due to the impact are detected by the movement of the adjusting body 104.

A contact combustion type gas detection device 110 shown in FIG. 11 is a device in which the filament glass fiber 44 is densely wound on both the front and back surfaces of the detection body 111 and the comparison body 112, and is used as a reference for the measurement in this embodiment. It is a comparative sample for.

FIG. 9 is a diagram showing the movement of the zero point due to an impact. The conventional example (a band-shaped glass wool is wrapped around a support pin and no vertical buffer is provided) is shown on the horizontal axis from the left. The first embodiment, the second embodiment, the third embodiment, the fourth embodiment, and the fifth embodiment are taken, and the vertical axis has a zero-point fluctuation range. This figure shows the zero point fluctuation when a shock of 100 G is applied to each sample (10 pieces) in the vertical direction. Black circles indicate initial values, curve a indicates a maximum value, and curve b indicates a minimum value. As shown in the figure, it is understood that the product of the present invention has significantly improved impact resistance as compared with the conventional product.

FIG. 10 shows the sensitivity of each embodiment.
From the left end on the abscissa, do not wind glass wool in order, conventional ones (only the belt-shaped glass wool is wound),
The first embodiment, the second embodiment, the third embodiment, the fourth embodiment, the fifth embodiment, and a comparative sample (shown in FIG. 11) are taken, and the vertical axis represents H ₂ 1000 ppm. The sensor output in the case is taken. As shown in the figure, it can be seen that the reduction in sensitivity due to the buffer means of this embodiment has almost no effect.

[0032]

As described above in detail, according to the present invention, a horizontal buffer for alleviating the lateral displacement of the detection element and the comparison element is provided, and a vertical buffer for alleviating the vertical displacement is provided. Since the body is provided, the impact resistance can be greatly improved without lowering the sensitivity, that is, while maintaining the high sensitivity configuration.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of a main part of a first embodiment of the present invention as viewed from the front.

FIG. 2 is a cross-sectional explanatory view of a main part in the same manner.

FIG. 3 is an explanatory sectional view of a main part of a second embodiment of the present invention as viewed from the front.

FIG. 4 is a cross-sectional explanatory view of a main part of the same.

FIG. 5 is an explanatory sectional view of a main part of a third embodiment of the present invention as viewed from the front.

FIG. 6 is an explanatory sectional view of a main part of a fourth embodiment of the present invention as viewed from the front.

FIG. 7 is an explanatory sectional view showing a main part of a fifth embodiment of the present invention as viewed from the front.

FIG. 8 is a circuit diagram illustrating a measuring apparatus according to each embodiment of the present invention.

FIG. 9 is an explanatory view of impact resistance.

FIG. 10 is a sensitivity explanatory diagram.

FIG. 11 is an explanatory diagram of a sample for comparative measurement.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 Base 12,13 Support pin 15 Detecting element 16 Detecting part 18 Detector 21 Comparative body 22,23 Support pin 25 Comparative element 26 Comparison part 28 Cap 30,40,50,60,70 Buffer means 31,41,71 Vertical direction Buffer 35, 45, 55, 65, 75 Lateral buffer 42, 43, 46, 47 Buffer member

Claims (1)

(57) [Claims] 1. A detector in which a linear detecting element having a detecting portion formed in a middle part is stretched and fixed to a pair of support pins fixed to a base, and a detecting body provided close to the detecting body is compared with the middle part. A comparative body in which a linear comparison element formed with a portion is stretched and fixed to a pair of support pins fixed to the substrate, a gas-permeable cap covering the detection body and the comparative body and attached to the substrate, A contact-combustion gas detection device provided in the cap and configured to reduce a displacement of the detection unit and the comparison unit due to an impact, wherein the buffer unit is arranged in a longitudinal direction in which a support pin extends. The displacement of the detection unit is reduced, and the detection unit side
Formed by winding and stretching glass fiber around a pair of support pins
The shock absorber is provided on both sides of the detector in the vertical direction.
A vertical buffer, and alleviates the displacement of the detection unit in a horizontal direction that intersects the vertical direction that the vertical buffer relaxes.
Wherein a pair of support pins on the detection body side are glass
A cushioning member formed by winding and stretching the fiber
The crossing point of the crossing crosses the detector from both sides in the lateral direction.
And lateral cushion which is constructed by providing to counter, the comparison
Formed by winding and stretching glass fiber around a pair of support pins on the body side
Cushioning members are provided on both sides in the vertical direction of the comparison section.
The formed vertical buffer and a pair of support pins on the side of the comparative body
Formed by winding and stretching glass fiber in a cross
When the crossing part of the cross member is crossed to the comparison part,
A contact combustion type gas detection device comprising: a lateral shock absorber provided so as to be opposed from the side .