JPH0246093B2 - - Google Patents

Description

[Detailed description of the invention] Purpose of the invention (industrial application field)
This invention relates to a device for measuring swelling pressure when swelling occurs due to penetration of liquid such as gasoline or oil.

(Prior art) When rubber is used in a state where it comes into contact with oil or is immersed in oil, such as in automobiles and boats, it swells due to the penetration of the oil or gasoline, and if this swelling pressure is abnormally large, this is the case near the rubber. etc. may be deformed or broken.

Therefore, the apparatus described in Japanese Utility Model Publication No. 13725/1983 has been used. In this device, a sample is placed at the bottom of a sample tube, a detection rod of the device that measures the change in length of the sample is brought into contact with the top surface of the sample, and a penetrant is supplied into the test tube to remove the sample. The purpose is to measure swelling pressure.

(Problem to be solved by the invention) However, in this device, when the sample swells, the direction in which the sample stretches is not restricted at all, so the sample stretches in each direction, up, down, left and right, increasing the swelling pressure. The problem is that it cannot be measured accurately.

Furthermore, since there is no particular method for supplying the permeate to the sample, it is not possible to determine the permeation rate of the permeate, the relationship between the swelling curve and the swelling pressure, etc.

The purpose of this invention is to not only enable easy, highly sensitive, and highly accurate measurement of the swelling pressure of polymeric materials such as rubber and synthetic resins due to various penetrating liquids under various conditions, but also to measure the permeation rate of the penetrating liquid. Another object of the present invention is to provide a novel swelling pressure measuring device that can determine the relationship between a swelling curve and swelling pressure.

Structure of the Invention (Means for Solving the Problems) In order to solve the above problems, the present invention provides rubber,
A storage member 15 surrounds the side surface of the test piece S so that the test piece S made of a polymeric material such as a synthetic resin is distorted only in the vertical direction due to swelling by the permeate liquid L such as oil or gasoline; A penetrating member 4 disposed on one of the upper and lower end faces of the storage member 15 so as to gradually penetrate from one end face of the test piece S, and a part of the containing member 15 on which the penetrating member 4 is disposed. A swelling pressure measuring device was used, which included a measuring member 17 disposed on the other end face opposite to the end face, and measuring the swelling pressure by detecting the distortion of the test piece S.

(Function) When the swelling pressure measuring device of the present invention is immersed in a penetrating liquid L such as oil or gasoline, the penetrating liquid L gradually penetrates into the test piece S by the penetrating member 4. At this time, the test piece S gradually swells from one end to the other and its volume increases, but the test piece S is restrained from lateral distortion by the storage member 15, and the permeation member 4 Since the strain on one end surface is also restrained by
The measuring member 17 extends greatly toward the other end surface where the measuring member 17 is arranged.
Strain is measured by

In addition, by providing the permeation member 4, the permeation liquid L gradually permeates from one end surface of the test piece S, so that the relationship between the permeation rate of the permeation liquid into the polymer material, the swelling curve, and the swelling pressure is etc. are required.

(Embodiment) An embodiment embodying the present invention will be described below with reference to the drawings. In the drawing, reference numeral 1 is a disc-shaped substrate at the bottom, and a through hole 2 is provided in the center. A support portion 3 having a reduced diameter is formed at the bottom of the through hole 2 to prevent it from coming off.

Reference numeral 4 is a permeation member for the permeation liquid L such as oil or gasoline stored in the through hole 2, and is roughly formed as a whole from sintered metal and has many fine pores 5 in the vertical direction. It is perforated and the penetrating liquid L
gradually penetrates from the lower end surface to the upper end surface.

Reference numeral 6 denotes three through holes provided around the through hole 2 of the base 1. Reference numeral 7 designates three vertical mounting bolts whose lower ends are welded into the vicinity of the outer periphery of the base plate 1. Reference numeral 8 denotes two guide rods which are similarly installed near the outer periphery of the base 1, and whose upper ends are tapered.

Reference numeral 9 denotes a storage board superimposed on the top surface of the base 1, with five through holes 10 provided near its outer periphery.
The mounting bolt 7 and the guide rod 8 are inserted into the hole 6, thereby positioning the mounting bolt 7 and the guide rod 8, and the screw 13 passing through the through hole 6 is screwed into the screw hole 12 around the through hole 11 formed at the center. It is attached to the base 1.

Reference numeral 14 denotes a screen made of wire mesh that is sandwiched between the base 1 and the storage board 9 so as to be located between the through holes 2 and 11; is supported.

Reference numeral 15 denotes a storage member inserted into the through hole 11 of the storage board 9, which has a storage hole 16 formed in the center, and a rubber member formed in the storage hole 16 with an outer diameter that is approximately the same as the inner diameter of the storage hole 16. , a test piece S made of a polymeric material such as a synthetic resin is housed therein.

Reference numeral 17 denotes a measurement member installed on the upper surface of the test piece S, in which a bronze pressing ring 20 is installed in an upright state with screws 23 in a recess 19 formed on the upper surface of the lower disc-shaped table 18. ing. Reference numeral 21 denotes strain gauges affixed to the left and right sides of the outer circumferential surface of the press ring 20, and active gauges 21A are arranged in the vertical direction so as to detect the elongation in the vertical direction.
and a dummy gauge 21D for temperature compensation which is arranged perpendicularly thereto and does not expand or contract itself. Each strain gauge 21A, 21D is connected to the sixth strain gauge 21A, 21D.
As shown in the figure, it is assembled into a Wheatstone bridge circuit, and the distortion of the pressing ring 20 can be detected as a voltage change with a meter 22 with high sensitivity and accuracy.

Reference numeral 24 denotes a regulation plate that regulates the upper end position of the pressing ring 20 of the measuring member 17, and is positioned by inserting the mounting bolt 7 and guide rod 8 into five through holes 25 provided near the outer circumference of the plate. ing. Then, until the upper end of the pressing ring 20 is slightly pressed by the center of the bottom of the regulation plate 24,
This regulation plate 24 is tightened by a nut 26 that is screwed into the mounting bolt 7.

Now, in order to measure the swelling pressure of a polymer material using the swelling pressure measuring device configured as described above, first, as shown in FIG. After installing the screen 14 on the permeation member 4, the storage board 9 is attached to the base 1 with screws 13. Next, as shown in FIGS. 1 and 4, a test piece S made of a polymeric material such as rubber or synthetic resin is processed to have an outer diameter that is approximately the same as the inner diameter of the storage hole 16. The measurement member 1 is inserted into the storage hole 16 and placed on the test piece S.
7 and connect the strain gauge 21 as shown in FIG.

Subsequently, the mounting bolts 7 and the guide rods 8 are inserted into each of the through holes 25, and the regulation plate 24 is placed on the pressure ring 20 of the measurement member 17. Then, nuts 8 are screwed onto each mounting bolt 7 and set so that the upper end of the pressing ring 20 is slightly pressed by the center of the bottom surface of the regulating plate 24.

The swelling pressure measuring device set in this way was
As shown in the figure, when the storage panel 9 is immersed in the penetrating liquid L such as oil or gasoline to the vicinity of the upper end, the penetrating liquid L penetrates from the lower end surface of the penetrating member 4, passes through the screen 14, and passes through the lower end surface of the test piece S. reach. Therefore, the test piece S gradually swells from the lower end to the upper end due to the penetration of the penetrating liquid L, and its volume increases. Here, since the radial distortion of the test piece S is restrained by the storage member 15, the test piece S extends in the axial direction to a greater extent than when the test piece S is not restrained.

Then, the pressure ring 20 of the measurement member 17 is pressed upward via the stand 18 by the swelling pressure of the test piece S, so that it is elastically compressed in the vertical direction and deformed into a circular shape. Therefore, since the surfaces of both outer circumferential sides of the press ring 20 are stretched in the circumferential direction under tensile force,
Of both strain gauges 21, the resistance of the active gauge 21A increases. On the other hand, since the same surface of the press ring 20 receives almost no force in the direction orthogonal to the circumferential direction, the dummy gauge 21D functions as a temperature compensation device without any resistance change.

Therefore, the balance of the Wheatstone bridge circuit shown in FIG.

In order to know the swelling pressure value, the relationship between the amount of strain measured by the strain gauge 21 and the load may be determined in advance using a tensilon or the like, and a calibration curve may be created.

In this way, it is possible to easily determine the relationship between the volume change rate of the polymeric material and the swelling pressure, the difference in swelling pressure depending on the type of polymer and the penetrating liquid, and the relationship between the swelling pressure and test conditions such as test temperature.

Furthermore, in this example, since the strain in the radial direction of the test piece S is restrained and two active gauges 21A are used, the swelling pressure can be measured with high sensitivity and high accuracy. Furthermore, since the penetrating liquid L was allowed to gradually permeate from the lower end surface of the test piece S, it was also possible to determine the permeation rate of the penetrating liquid into the polymer material, the relationship between the swelling curve and the swelling pressure, and the like.

Note that the present invention is not limited to the configuration of the above-mentioned embodiments; for example, the measurement member may be formed into a clip shape and a strain gauge may be attached to this, or a pressure sensitive element, a differential transformer, or a dial may be used instead of the strain gauge. It is also possible to arbitrarily change the shape and configuration of each part without departing from the spirit of the invention, such as configuring the measuring member to use a gauge or the like.

(Effects of the Invention) As detailed above, the present invention provides that the test piece S made of a polymeric material such as rubber or synthetic resin is
A storage member 15 surrounds the side surface of the specimen S so that it is distorted only in the vertical direction due to swelling by the penetrating liquid L such as gasoline, and a housing member 15 is arranged so that the penetrating liquid L gradually penetrates from one end surface of the specimen S. a permeation member 4 disposed on either one of the upper and lower end surfaces of;
A measurement member 17 is provided on the other end face of the storage member 15 opposite to one end face on which the permeation member 4 is disposed, and is configured to detect distortion of the test piece S and measure swelling pressure. By using a swelling pressure measuring device, it is not only possible to easily and highly sensitively and accurately measure the swelling pressure of polymer materials such as rubber and synthetic resins due to various penetrating liquids under various conditions, but also to It is also effective in determining the permeation rate of the permeate into the polymer material, the relationship between the swelling curve and the swelling pressure, etc.

[Brief explanation of drawings]

Fig. 1 is a central vertical sectional view of an embodiment embodying the present invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 is a partially exploded perspective view showing the method of assembling the embodiment. Similarly, FIG. 4 is an exploded perspective view showing how to install the test piece and the measuring member, FIG. 5 is a side view of the measuring member, and FIG. 6 is a circuit diagram showing how to connect the strain gauge. Penetration member...4, Storage member...15, Measuring member...17, Stand...18, Recess...19, Pressure ring...20, Strain gauge...21, Test piece...
S, Penetrating liquid...L.

Claims (1)

[Scope of Claims] 1. A test piece S made of a polymeric material such as rubber or a synthetic resin is deformed only in the vertical direction due to swelling by a penetrating liquid L such as oil or gasoline.
a storage member 15 surrounding the side surface of the storage member 15; a permeation member 4 disposed on one of the upper and lower end surfaces of the storage member 15 so that the penetrating liquid L gradually permeates from one end surface of the test piece S; A measurement member 17 is provided on the other end face of the member 15 opposite to the one end face on which the permeation member 4 is disposed, and is adapted to detect the distortion of the test piece S and measure the swelling pressure. Characteristic swelling pressure measuring device. 2 The measurement member 17 is a stand 18 that comes into contact with the test piece S.
, a pressure ring 20 installed in an upright state in the recess 19 of the stand 18 , and a strain gauge 21 affixed to both sides of the outer periphery of the pressure ring 20 . Pressure measuring device. 3. The swelling pressure measuring device according to claim 1, wherein the measuring member is a pressure sensitive element. 4. The swelling pressure measuring device according to claim 1, wherein the measuring member is a differential transformer.