JPH11101730A - Characteristic measuring sample container for hydrogen occlusion alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure characteristics of a hydrogen occlusion alloy having, for example, low equilibrium hydrogen pressure at arbitrary temperature by ensuring a severe seal even at negative pressure in a sample container. SOLUTION: In the characteristic measuring sample container for hydrogen occlusion alloy comprising in combination a first flat plate 1 having a recess 2 for filling measuring alloy sample 10 and a second flat plate 3 having a protrusion 4 to be engaged with the recess 2, connecting surfaces of the plates 1, 3 are formed flat, and a surface sealing structure 11 such as a gasket 12, a bead 13 and the like is provided at the connecting surfaces. Thus, sealing without leakage in a wide range from vacuum to a positive pressure is executed by adopting the structure 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for evaluating various characteristics of a hydrogen storage alloy, and more particularly to a sample container for measuring the same.

[0002]

2. Description of the Related Art The hydrogenation characteristics of a hydrogen storage alloy include PCT.
Although there are various characteristics such as characteristics and reaction heat characteristics, the reaction speed is the most important characteristic among them.

A method for measuring the reaction rate of the hydrogen storage alloy is specified by Japanese Industrial Standards (JIS H).
7202 Test method for hydrogenation rate of hydrogen storage alloy). FIG. 3 shows a basic configuration of a test apparatus specified in JIS H7202. The test equipment is a thermostatic bath 2 with good temperature control performance.
3 and a filter 22 having a small pressure loss.
A metal sample container 21 having a high thermal conductivity in which
Accumulator 24 with sufficiently large volume and high-precision pressure gauge 25
And a relief valve 26 connected via an open / close valve 27 having good responsiveness and low flow resistance. The reaction rate is measured by recording the time change of the hydrogen pressure with the pressure gauge 25 by the Siebert's (capacity) method.

[0004] As shown in FIG.
It comprises a first flat plate 31 formed with a concave portion 32 for receiving a measurement sample, and a second flat plate 33 formed with a convex portion 34 that fits into the concave portion 32 to form a sample chamber 35.
The material of the first and second flat plates 31 and 33 is made of a material such as stainless steel, copper, and brass which has high thermal conductivity and is hard to be embrittled with hydrogen, and has a mass 1000 times or more that of the sample because of its role as a heat sink. It is desirable to have. First
The flat plate 31 and the second flat plate 33 are composed of a bolt 36 and a nut 37.
Are connected by The inside of the sample chamber 35 is sealed by a rubber O-ring 38, and the filter 22 and the thin sample 40 are accommodated therein.

[0005] The rubber O-ring 38 serves as a gas seal and at the same time plays a role of pressing the sample 40 against the heat sink with an appropriate pressure. The filter 22 is required to have a hole diameter of about 1 μm, but a filter having a small pressure loss is desired. The sample container 21 is connected to the hydrogen supply pipe 3
9 is connected to the reaction rate measuring device main body shown in FIG.

[0006]

However, the hydrogenation rate may be strongly affected by impurities in hydrogen,
Air pollution must also be avoided. Therefore, when the inside of the sample container 21 is set to the atmospheric pressure or less in the hydrogen releasing operation, a strict seal is required so that air or moisture is not mixed. However, in the above-described conventional sample container 21, the O-ring 38 works effectively when the sample chamber 35 is at a positive pressure, but the sealing is incomplete when the inside of the sample chamber 35 is at a negative pressure, that is, at an atmospheric pressure or less. There was a problem.

However, since it is generally difficult to strictly inspect the leakage of the sample container 21 after the sample is filled, a method of releasing the atmospheric pressure is recommended as a simple countermeasure against the above problem. Therefore, in order to measure the reaction rate of a hydrogen storage alloy having a low equilibrium hydrogen pressure, it is necessary to set the measurement temperature to a temperature at which the equilibrium hydrogen pressure becomes equal to or higher than the atmospheric pressure. there were.

[0008] In view of the above-mentioned conventional problems, the present invention can secure a strict seal even when a negative pressure is applied to the inside of a sample container. It is an object of the present invention to provide a sample container for measuring characteristics of a hydrogen storage alloy that can be used.

[0009]

According to the present invention, there is provided a sample container for measuring characteristics of a hydrogen storage alloy according to the present invention, comprising a first flat plate having a concave portion for accommodating an alloy sample for measurement, and a convex portion fitted with the concave portion. In the first invention, in the sample container for measuring the characteristics of the hydrogen storage alloy formed by combining the second flat plate and the second flat plate, the joint surface between the first flat plate and the second flat plate is a flat surface, and a face seal structure is provided on the joint surface. The surface seal structure allows for a leak-free seal in a wide range from vacuum to positive pressure, and the characteristics can be measured at any temperature, even for hydrogen storage alloys with low equilibrium hydrogen pressure. .

In the second invention, the O-ring is formed by forming an O-ring groove on the side wall of the convex portion of the second flat plate, and the O-ring provided on the fitting surface between the concave portion and the convex portion. Due to the seal structure, sealing without leakage can be performed in a wide range from vacuum to positive pressure, and the same effect as above can be obtained.

Further, when a filter and a filter retaining ring which fit into the concave portion are arranged in the concave portion of the first flat plate, the sample is securely pressed to the bottom surface of the concave portion of the first flat plate as the heat sink via the filter. The temperature of the sample can be stabilized, and the measurement can be performed with high accuracy.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sample container for measuring characteristics of a hydrogen storage alloy according to the present invention will be described below with reference to FIGS.

(First Embodiment) In FIG. 1, a sample container has a first flat plate 1 formed with a concave portion 2 for receiving a sample for measurement, and a convex formed by fitting with the concave portion 2 to form a sample chamber 5. Part 4
The second flat plate 3 is formed with The materials of the first and second flat plates 1 and 3 are high in thermal conductivity so as to stabilize the sample temperature and hard to embrittle with hydrogen.
It is desirable that the sample is made of a material such as copper or brass and has a mass 1000 times or more that of the sample from the role of a heat sink. The first flat plate 1 and the second flat plate 3 are bolts 6
And nut 7.

In the sample chamber 5, a Teflon ring 8 as a filter holding ring, a filter 9, and a sample 10 are arranged. The layer of the sample 10 must always be pressed against the heat sink and its thickness needs to be reduced. The Teflon ring 8 has no function as a gas seal, but has a role of pressing the sample 10 against the heat sink with an appropriate pressure. It's done. The filter 9 is the same as the conventional example.
A hole having a pore diameter of about 1 μm is required, but a small pressure loss is desired. The gas seal is composed of the first flat plate 1 and the second flat plate.
This is achieved by a face seal structure 11 including a gasket 12 and a bead portion 13 arranged on the joint surface of the flat plate 3. The gasket 12 is desirably a metal gasket made of a metal such as nickel or copper. This sample container is connected to a reaction rate measuring device main body (not shown) through a hydrogen supply pipe 14.

In the present embodiment, since the surface seal structure is used, gas sealing without leakage can be performed in a wide range from vacuum to positive pressure. Further, when a metal gasket is used as the gasket 12, gas sealing can be performed normally even at a high temperature of 200 to 300 ° C., so that the reaction rate can be measured even at a high temperature.

In the present embodiment, the metal gasket type face seal structure 11 is employed, but another type of face seal structure such as an O-ring type may be employed.

(Second Embodiment) In FIG. 2, the same components as those described with reference to FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, the gas seal employs an O-ring seal structure provided on the peripheral side surface of the concave portion 2 and the convex portion 4 instead of the surface seal structure.

In the illustrated example, an O-ring groove 16 is formed on the outer peripheral surface of the convex portion 4, and the O-ring groove 16 is compressed on the inner peripheral surface of the concave portion 2 to exhibit a predetermined sealing performance.
Is installed. The O-ring 17 is desirably made of rubber such as Viton. The O-ring groove 16 is cut in parallel with the outer peripheral surface of the projection 4 so as to be able to cope with both positive pressure and negative pressure.

In the present embodiment, since the O-ring seal structure is used, a gas seal without leakage in a wide range from vacuum to positive pressure can be performed.

It is also possible to perform more strict gas sealing by combining the face seal structure of the first embodiment and the O-ring seal structure of the second embodiment.

In the above embodiment, an example is shown in which the present invention is applied to a reaction rate measuring device. However, the sample container of the present invention can obtain the same effect even with other characteristic measuring devices such as a PCT measuring device and a reaction heat measuring device. Can be.

[0022]

According to the sample container for measuring the characteristics of the hydrogen storage alloy of the present invention, as is apparent from the above description, the first flat plate having the concave portion for receiving the alloy sample for measurement, the concave portion, In a sample container for measuring characteristics of a hydrogen storage alloy, which is formed by combining a second flat plate having a fitting projection,
In the present invention, the joint surface between the first plate and the second plate is a flat surface, and the surface seal structure is provided on the joint surface. Therefore, a leak-free seal can be performed in a wide range from vacuum to positive pressure, and even if the balance is low. Characteristics can be measured at an arbitrary temperature even in a hydrogen storage alloy having a hydrogen pressure.

In the second invention, the O-ring groove is formed on the side wall of the convex portion of the second flat plate, and the O-ring is disposed. Therefore, the O-ring seal structure provided on the fitting surface between the concave portion and the convex portion. Thus, sealing without leakage can be performed in a wide range from vacuum to positive pressure, and the same effect as above can be obtained.

Further, when a filter and a filter retaining ring fitted to the concave portion are arranged in the concave portion of the first flat plate, the sample is reliably pressed to the bottom surface of the concave portion of the first flat plate as the heat sink via the filter. The temperature of the sample can be stabilized, and the measurement can be performed with high accuracy.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of a sample container for measuring characteristics of a hydrogen storage alloy according to the present invention.

FIG. 2 is a longitudinal sectional view of a second embodiment of a sample container for measuring characteristics of a hydrogen storage alloy according to the present invention.

FIG. 3 is a configuration diagram of a reaction rate measuring device for a hydrogen storage alloy.

FIG. 4 is a longitudinal sectional view of a sample container for measuring characteristics of a conventional hydrogen storage alloy.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 first flat plate 2 concave portion 3 second flat plate 4 convex portion 8 Teflon ring (filter holding ring) 9 filter 11 face seal structure 16 O-ring groove 17 O-ring

Claims (3)

[Claims] 1. A sample for measuring the characteristics of a hydrogen-absorbing alloy comprising a combination of a first flat plate having a concave portion for accommodating a measuring alloy sample and a second flat plate having a convex portion fitted with the concave portion. A sample container for measuring characteristics of a hydrogen storage alloy, wherein a joining surface between a first flat plate and a second flat plate is a flat surface, and a surface sealing structure is provided on the joining surface. 2. A sample for measuring characteristics of a hydrogen-absorbing alloy comprising a combination of a first flat plate having a concave portion for accommodating a test alloy sample and a second flat plate having a convex portion fitted with the concave portion. A sample container for measuring characteristics of a hydrogen storage alloy, wherein an O-ring groove is formed in a side wall of a convex portion of a second flat plate. 3. The sample container for measuring characteristics of a hydrogen storage alloy according to claim 1, wherein a filter and a filter retaining ring fitted into the concave portion are arranged in the concave portion of the first flat plate.