JP4905895B2 - Apparatus and method for measuring apparent density of porous parts - Google Patents

Description

  The present invention relates to an apparatus and a method for measuring the apparent density of an amorphous porous part such as a sintered part before pressure firing.

  When measuring the apparent density of porous parts mainly composed of pores such as iron powder, copper powder, carbon powder, etc., the weight G and volume V are measured, and the apparent density D is defined as the ratio G / V. It is common to calculate.

  However, when the object to be measured is an irregular shaped porous part such as a sintered part before pressure firing, it is difficult to accurately measure the volume V because it is irregular. Therefore, when measuring the apparent density of such irregular porous parts, ionizing radiation such as X-rays and γ-rays is used, and conventionally, the scattering and transmission of radiation due to the difference in density have been used. However, this means has a problem in that radiation management in handling is complicated and variation in measurement accuracy is large (for example, 8% or more).

  In order to solve this problem, Patent Document 1, Non-Patent Document 1, and the like have been proposed as means for measuring the apparent density of an amorphous porous component without using X-rays, γ-rays, or the like.

  As schematically shown in FIG. 4, the means of Patent Document 1 includes (A) a liquid weight Gfl having a known density ρ in a container 2 up to a predetermined level S, and (B) a porous electrode plate 1 (measured). Measure the weight Ga in the container up to the same level S with the liquid 3 absorbing the liquid 3 and (C) the weight Gb of the electrode plate 1 with the liquid 3 absorbed, and ΔG = Gfl−Ga + Gb The liquid weight corresponding to the volume V of the electrode plate is obtained, and the volume V of the electrode plate is obtained by V = ΔG / ρ. (D) The ratio Gc / V is obtained from the dry weight Gc of the electrode plate and the volume V of the electrode plate. The apparent density D is calculated.

  The means of Non-Patent Document 1 are: (A) Injecting an appropriate amount of glass beads into a graduated cylinder, tap lightly to make it close-packed, measure its volume V, (B) Transfer the glass beads to another container, Put a pumice sample (object to be measured) whose dry weight W has been measured in advance into a measuring cylinder, inject glass beads again, measure the volume V ′ of pumice + glass beads, and (C) the apparent density D of pumice D = W / (V′−V).

Japanese Patent Laid-Open No. 6-349528, “Method and apparatus for determining physical parameters of storage battery electrode plate”

Tatsuo Sasaki, Yoshio Katsui, “Pensite Density Measurement Using Glass Beads”, Vol. 2 Vol. 26, (1981), No. 2, pages 117-118

The above-described measuring means using X-rays, γ-rays, etc. have a problem in that radiation management is complicated and variation in measurement accuracy is large (for example, 8% or more).
Moreover, since the means of Patent Document 1 fills the pores of the object to be measured with a liquid, a post-process (drying or the like) for completely removing the liquid after the measurement is necessary, and the liquid filling and the removing process ( There is a risk that the physical properties of the object to be measured may change due to drying.
Further, the means of Non-Patent Document 1 has a problem that the glass beads are broken during use and the particle size distribution is likely to change, so that the error is large (over 20%) in the case of pumice with a large foaming degree. there were.

  The present invention has been developed to solve the above-described problems. That is, the object of the present invention is that no radiation management such as X-rays and γ-rays is required, no post-process such as drying is necessary, there is no risk of changes in physical properties of the object to be measured, and the shape is simple and highly accurate An object of the present invention is to provide an apparatus and a method for measuring an apparent density of a porous part capable of measuring the apparent density of the porous part.

According to the present invention, beads having a particle diameter that cannot penetrate into the pores of the porous part for measuring the apparent density;
A container having an opening through which the porous part can pass, and capable of accommodating the porous part and beads therein;
A lid member that closes the opening in an openable and closable manner, and accommodates the porous part between the container and fills the beads without any gaps around the porous part;
A vibrator capable of vibrating the container until all the beads reach a close-packed state, with the opening closed with a lid member and filled with beads around the porous part without gaps;
A device for measuring the apparent density of a porous part, comprising a volume measuring unit capable of measuring the volume V ′ of the whole bead including the porous part and the volume V of only the bead excluding the porous part, is provided.

  According to a preferred embodiment of the present invention, the beads are ceramic beads having a hardness that is not damaged by the vibration of the vibrator and having a substantially constant spherical shape.

  The beads are preferably zirconia beads having a diameter of 0.5 to 1.5 mm.

According to the present invention, a bead having a particle size that cannot enter the pores of a porous part having a mass W for measuring the apparent density is prepared.
The beads having a volume V are accommodated in a close-packed state with the porous part between a container having an opening through which the porous part can pass and a lid member that closes the opening so as to be openable and closable.
With the beads filled around the porous part with no gaps, vibrate the container until all beads reach a close-packed state,
Measure the volume V ′ of the entire bead including the porous part after vibration,
There is provided a method for measuring the apparent density of a porous part, wherein the apparent density D is obtained by D = W / (V′−V).

According to a preferred embodiment of the present invention, a plurality of ceramic beads having a spherical shape that cannot penetrate into the pores of the porous part and having different diameters are prepared,
Using each ceramic bead, the volume V of only the bead and the volume V ′ of the entire bead including the porous part are respectively measured, and the bead having the smallest ΔV = V′−V is used.

  The beads are preferably zirconia beads having a diameter of 0.5 to 1.5 mm.

According to the apparatus and method of the present invention described above, the beads in the close-packed state are filled with the volume V ′ of the entire bead including the porous parts in which the beads are filled without gaps around the porous parts and the beads are in the close-packed state. As a difference ΔV = V′−V of the volume V, it is possible to directly measure the volume of the entire amorphous porous part having pores.
Accordingly, the overall average apparent density can be easily obtained from this and the mass W of the porous part. This eliminates the need for special management for radiation, and provides higher measurement accuracy with a simple work process.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is an overall configuration diagram of an apparent density measuring apparatus according to the present invention.
In this figure, an apparent density measuring apparatus 10 of the present invention includes beads 12, a container 14, a lid member 16, a vibrator 18, and a volume measuring means 20.

The beads 12 are beads having a particle diameter that cannot enter the pores of the porous part 1 for measuring the apparent density. The beads 12 have a hardness that does not break due to the vibration of the vibrator 18 and have a low true density in order to reduce the surface pressure acting on the porous component 1 that is easily damaged, such as a sintered component before pressure firing. A material is preferable.
In order to satisfy such conditions, the beads 12 are preferably ceramic beads having a substantially constant spherical shape, and particularly preferably zirconia beads having a diameter of 0.5 to 1.5 mm.

The container 14 has an opening through which the porous component 1 can pass, and can accommodate the porous component 1 and the beads 12 therein. In this example, the container 14 is a cylindrical container having a bottom, and includes a discharge pipe 14a for discharging the beads 12 on a side portion thereof, and an opening / closing valve 15a that closes the tip of the container 14 so as to be opened and closed.
In addition, the container 14 is not limited to this form, An arbitrary shape may be sufficient.

The lid member 16 is configured to close the opening of the container 14 so as to be openable and closable, and to accommodate the porous component 1 between the container 14 and fill the beads 12 around the porous part 1 without a gap.
In a state where the opening of the container 14 is closed by the lid member 16, the connecting portion is sealed so that the beads 12 do not leak to the outside, and the beads 12 have a smooth inner surface shape so that they do not bridge each other. Has been.

  In addition, the container 14 and the cover member 16 of this invention are not limited to the structure mentioned above, For example, you may form both integrally.

  The vibrator 18 has a function of vibrating the container 14 until the beads 12 reach a close-packed state with the opening of the container 14 closed by the lid member 16. In the present application, the “close-packed state” is different from the close-packed structure in the molecular structure (face-centered cubic structure and hexagonal close-packed structure), and the beads come into contact with each other to maximize the apparent density of the entire bead. Means state.

  The volume measuring means 20 is a graduated cylinder in this example, and is integrally provided on the upper part of the lid member 16 and measures the volume V ′ of the entire bead including the porous component 1 and the volume V of only the bead excluding the porous component 1. A scale is provided where possible.

  The volume measuring means 20 of the present invention is not limited to the above-described configuration, and for example, the position of the upper end of the bead may be detected using an optical sensor or laser light instead of the graduated cylinder.

FIG. 2 is an explanatory diagram of the apparent density measuring method of the present invention using the above-described apparatus.
As shown in this figure, the method of the present invention comprises four steps (A) to (D).
In step (A), a predetermined amount of beads 12 are filled in an empty container 14 whose opening is closed by a lid member 16, and the container 14 is vibrated until it is packed most closely with a vibrator, and then the scale of the graduated cylinder is read. The volume V of only the beads 12 is stored or recorded.
In step (B), the opening / closing valve 15a is opened to partially extract the beads 12 from the container 14 into the auxiliary container 22, the lid member 16 is removed, the porous component 1 is accommodated therein, and the opening is closed again with the lid member 16. .
In step (C), the bead 12 extracted in step (B) is refilled between the container 14 and the lid member 16 by opening the on-off valve 15b of the auxiliary container 22. Next, the vibrator 18 is filled with the beads 12 around the porous part 1 without any gaps and is vibrated until all the beads 12 reach the close-packed state. The volume V ′ is stored or recorded.
The volume of the device under test 1 is calculated from the difference ΔV = V′−V between the scale readings V ′ and V when the device under test 1 is obtained in the steps (A) and (C) described above. .
Further, in step (D), the mass W of the porous component 1 is measured using a precision balance.
The apparent density D of the porous component 1 can be obtained by D = W / (V′−V).

Step (A) described above may be after steps (B) and (C), and step (D) may be before steps (B) and (C).
Further, instead of measuring the volumes V ′ and V, the beads 12 may be filled up to the same level in the measuring cylinder, and the volume of the DUT 1 may be obtained from the difference in the required amount of beads.

  Further, in this method, a plurality of ceramic beads having different diameters that cannot penetrate into the pores of the porous component 1 whose apparent density is measured are prepared as the beads 12, and each of the ceramic beads is used to prepare the beads 12. It is preferable to measure the volume V ′ of the entire bead including the porous volume 1 and the volume V ′ of the entire porous part 1 by the method described above, and use a bead having a minimum ΔV = V′−V.

FIG. 3 is a schematic diagram of the bead diameter d and ΔV = V′−V.
Even if the bead diameter d is a spherical shape (d1 or more in the figure) that cannot enter the pores of the porous part 1, if the bead diameter d is large (a in the figure), the irregular shape of the porous part 1 Since the apparent density of the beads 12 tends to be coarser than the most dense state on the surface, the volume ΔV of the measured porous component 1 is larger than the accurate volume V ₀ .
Conversely, if the bead diameter d becomes too small (b in the figure), the particles tend to agglomerate and cause bridging, and the apparent density of the beads 12 becomes coarser than the close-packed state due to the bridging phenomenon. Similarly, the volume ΔV of the porous part 1 is larger than the accurate volume V ₀ .
Therefore, the exact volume of the porous component 1 can be obtained by using beads having a particle size (c in the figure) that minimizes ΔV = V′−V.

As described above, according to the apparatus and method of the present invention, the volume V of the entire bead including the porous part 1 in the state where the beads 12 are filled without gaps around the porous part 1 and the beads 12 reach the most dense state. As the difference ΔV = V′−V between the volume V of the beads and the close-packed state, it is possible to directly measure the volume of the entire amorphous porous part having pores.
Therefore, the overall average apparent density D can be easily obtained from this and the mass W of the porous component 1. This eliminates the need for special management for radiation, and provides higher measurement accuracy with a simple work process.

  In addition, this invention is not limited to the Example and embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.

1 is an overall configuration diagram of an apparent density measuring apparatus according to the present invention. It is explanatory drawing of the apparent density measuring method of this invention. FIG. 4 is a schematic diagram of a bead diameter d and ΔV = V′−V. It is a schematic diagram of the means of patent document 1.

Explanation of symbols

1 Porous parts,
10 Apparent density measuring device, 12 beads (zirconia beads),
14 container, 14a discharge pipe, 15a, 15b on-off valve,
16 lid member, 18 vibrator,
20 Volume measuring means (measuring cylinder),
22 Auxiliary container

Claims (6)

Beads of a particle size that cannot penetrate into the pores of the porous part that measures the apparent density,
A container having an opening through which the porous part can pass, and capable of accommodating the porous part and beads therein;
A lid member that closes the opening in an openable and closable manner, and accommodates the porous part between the container and fills the beads without any gaps around the porous part;
A vibrator capable of vibrating the container until all the beads reach a close-packed state, with the opening closed with a lid member and filled with beads around the porous part without gaps;
An apparent density measuring device for a porous part, comprising: a volume measuring unit capable of measuring a volume V ′ of the whole beads including the porous part and a volume V of only the beads excluding the porous part.   2. The apparent density measuring device for porous parts according to claim 1, wherein the beads are ceramic beads having a hardness that is not damaged by the vibration of the vibrator and having a substantially constant spherical shape.   The apparent density measuring device for porous parts according to claim 2, wherein the beads are zirconia beads having a diameter of 0.5 to 1.5 mm. Prepare beads with a particle size that cannot penetrate into pores of porous parts with mass W to measure apparent density,
The beads having a volume V are accommodated in a close-packed state with the porous part between a container having an opening through which the porous part can pass and a lid member that closes the opening so as to be openable and closable.
With the beads filled around the porous part with no gaps, vibrate the container until all beads reach a close-packed state,
Measure the volume V ′ of the entire bead including the porous part after vibration,
An apparent density measurement method for porous parts, wherein the apparent density D is obtained by D = W / (V′−V). A spherical shape that cannot penetrate into the pores of the porous part, and preparing a plurality of ceramic beads having different diameters,
The volume V of the beads only and the volume V 'of the whole beads including the porous part are respectively measured using each ceramic bead, and beads having a minimum ΔV = V′−V are used. 4. A method for measuring an apparent density of a porous part according to 4.   6. The method for measuring the apparent density of a porous part according to claim 5, wherein the beads are zirconia beads having a diameter of 0.5 to 1.5 mm.

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