JP4337045B2 - Liquid gasket evaluation method - Google Patents

Description

  The present invention relates to a so-called liquid gasket evaluation method in which the above-mentioned mating surfaces are sealed by applying and solidifying the mating surfaces between components, and in particular, a method capable of evaluating the dynamic durability of the liquid gasket. .

  Conventional evaluation methods for liquid gaskets include physical property tests such as hardness, elongation, tensile strength, and volume change of test pieces themselves prepared by solidifying liquid gaskets, as illustrated in FIG. The liquid gasket 33 to be tested is applied in an annular shape between the peripheral portions of the two flat plates 31 and 32 facing each other, and the flat plates 31 and 32 are tightened with bolts to solidify the liquid gasket 33, and then the flat plate 31. , 32 and the space 34 formed by the solidified liquid gasket 33 is subjected to fluid pressure with oil or the like, and it is checked whether the oil or the like leaks from the space 34 to the surroundings. I was going to judge.

  However, when the temperature change is repeated when the thermal expansion coefficient of each part is different, the mating surfaces of the parts to which the liquid gasket is applied will repeatedly rub against each other according to the difference in relative thermal deformation amount of each part. Therefore, the liquid gasket applied between each part is repeatedly subjected to a shearing load simultaneously with the compression load. However, it is a common practice to test the durability of the liquid gasket against such a dynamic load. In addition, since it is difficult to judge the quality of such durability by the conventional evaluation method for liquid gaskets, it is necessary to conduct an endurance test using an actual machine, which increases test cost and test time. Was a problem.

  The applicant does not know the existence of appropriate prior art document information related to the present invention at the time of this application.

  The present invention is intended to make it possible to relatively easily and quickly evaluate the dynamic durability of a liquid gasket.

  For this reason, the liquid gasket evaluation method according to the present invention is formed continuously on the first flat surface, the first inclined surface formed continuously with the first flat surface, and the first inclined surface. A second flat surface parallel to the first flat surface, a second inclined surface formed continuously with the second flat surface, and a second flat surface formed continuously with the second inclined surface and parallel to the first flat surface. 3 parts having two flat surfaces and different thermal expansion coefficients are superposed on each other, the first flat surfaces of the two parts are positioned to each other with a knock pin, and the two parts are tightened, And the temperature change common to said 2 components is repeatedly given in the state which solidified the liquid gasket applied between each said surface.

  That is, the two parts obtained by superimposing the flat surfaces and the inclined surfaces on each other are positioned and fastened to each other by the knock pins, and the liquid gasket applied between the surfaces is solidified. If the temperature change common to the two parts is repeatedly given in the state of being made into a state, the thermal expansion coefficients of the two parts are different, so that the flat surface based on the temperature change as the distance from the first flat surfaces positioned by the knock pins increases. As a result, the relative displacement amount of the two parts along the surface increases, and the thermal expansion direction of the two parts intersects at the connection portion between the flat surface and the inclined surface, and the friction between the two overlapping parts increases. The liquid gasket that has been applied and solidified between the surfaces of the two parts is farthest from the first flat surface, and the second inclined surface and the third flat surface, which are connecting portions between the flat surface and the inclined surface, Connection Since the largest dynamic load is repeatedly received, it is easy to break at this portion, that is, the solidified liquid gasket breaks according to a relatively small number of repeated temperature changes, and therefore, relative to the two parts. It becomes possible to evaluate the dynamic durability of the liquid gasket in a relatively simple and quick manner when a mechanical displacement is repeatedly applied.

Embodiments of the present invention will be described below with reference to the drawings.
1 and 2, each of the first jig 1 made of a shallow cup-shaped Al material and the second jig 2 made of an Fe material has first flat surfaces 11 and 21 at the periphery thereof, and a first flat surface. The first inclined surfaces 12 and 22 formed continuously at the folding angle α at both ends of the surfaces 11 and 21, respectively, and the first flat surface 11 formed at the first inclined surfaces 12 and 22 continuously at the bending angle α, respectively. , 21 are parallel to the second flat surfaces 13 and 23, and the second flat surfaces 13 and 23 are continuously formed at the folding angles α, respectively, and are inclined to the opposite sides of the first inclined surfaces 12 and 22, respectively. The first and second flat surfaces 11 and 21 and the third flat surfaces 15 and 25, which are continuously formed on the second inclined surfaces 14 and 24 at the folding angle α, respectively, and are located in the same plane, That is, the above surfaces are the first flat surfaces 11, 21 and the third flat surfaces 15, 2 The first jig 1 and the second jig 2 are formed so as to be symmetrical with respect to the first flat surfaces 11 and 21 and are connected in an annular shape so that the respective surfaces correspond to each other. They are superimposed on each other.

  In addition, the first jig 1 and the second jig 2 have bolt holes 3 formed in the first flat surfaces 11 and 21, the second flat surfaces 13 and 23, and the third flat surfaces 15 and 25, respectively. The liquid gasket 4 is applied to the whole between the peripheral portions, and the first jig 1 and the second jig 2 are tightened by the tightening force of a bolt (not shown) that passes through each bolt hole 3 and the liquid gasket 4 applied between the peripheral portions. The jig 2 is tightened to adjust the film thickness of the liquid gasket 4.

  Further, the first flat surfaces 11 and 21 and / or the third flat surfaces 15 and 25 of the first jig 1 and the second jig 2 are respectively formed by two dowel pins as described below. 21 is positioned at a knock pin position angle β from the center portion 21 (center position of the bolt hole 3), and the test article 5 is configured as described above.

Next, a method for evaluating the dynamic durability of the liquid gasket 4 will be described.
First, each of the bolt holes 3 and the liquid gasket 4 applied between the peripheral portions of the first jig 1 and the second jig 2 are inserted so that the liquid gasket 4 can be evaluated in a relatively short time. The tightening torque of the four bolts (diameter 6 mm) is set to 12 Nm, the film thickness of the liquid gasket 4 is adjusted to an appropriate size, and at about room temperature so that the liquid gasket 4 is almost completely solidified. Leave for 70 hours.

  After that, as a pretreatment, the test article 5 is placed in the cooling bath in a state where the engine oil is filled in the space 6 formed in the central portion of the first jig 1 and the second jig 2 that are overlapped with each other. In addition, the liquid gasket 4 is maintained at 150 ° C., which is the highest temperature at which the liquid gasket is used, for about 200 hours, and the inherent deterioration of the liquid gasket 4 is moderately promoted. The time required for testing can be shortened.

After the pre-treatment, with the engine oil in the space 6 pressurized to 0.15 MPa, the ambient temperature in the cooling / heating tank in which the test article 5 is placed is set to −30 ° C. for 2 hours and 150 ° C. for 2 hours. Change so that the cooling cycle with time is repeated.
That is, almost the same temperature change is given to the first jig 1 and the second jig 2 in the test article 5, and the solidified liquid gasket 4 receives so that the difference in thermal expansion between them increases. The maximum temperature 150 ° C is set as the upper limit temperature, and the lower limit temperature is set at -30 ° C, so that the temperature difference between the cooling and heating is increased as much as possible. The temperature changes gradually, and it takes about 1 hour and 30 minutes for the whole to reach the ambient temperature. Therefore, after maintaining the ambient temperature constant for 1 hour and 30 minutes, for example, 2 hours, respectively, The ambient temperature is changed, and the engine oil in the space 6 is pressurized so that the engine oil easily leaks in response to the breakage of the solidified liquid gasket 4. The breakage of the solidified liquid gasket 4 can be easily detected.

In this case, the folding cycle α and the knock pin position angle β were changed as follows, and the above cooling cycle was repeated until engine oil leaked outward from the space 6 due to the fracture of the solidified liquid gasket 4.
(1) As shown in FIG. 3 (a), knock pins A and A are provided at two locations where the knock pin position angle β is 45 ° and −135 °, ie, two locations on one diameter of the test article 5. Is set and the bending angle α is set to 135 °.
(2) When knock pins A and A are set as in the case of (1) above, and the bending angle α is 150 °.
(3) As shown in FIG. 3B, knock pins B and B are provided at two locations where the knock pin position angle β is 60 ° and −120 °, that is, two locations on one diameter of the test article 5 respectively. Is set and the bending angle α is set to 135 °.
(4) When knock pins B and B are set in the same manner as in (3) above, and the bending angle α is set to 150 °.
(5) As shown in FIG. 3 (c), when the knock pins C and C are set at two positions of the knock pin position angle β of 45 ° and −45, respectively, and the bending angle α is set to 135 °, respectively. .
(6) When knock pins C and C are set in the same manner as in (5) above, and the bending angle α is set to 150 °.

  As a result, in the case of the above (5) and (6), the X portion (the connection portion between the second flat surfaces 13, 23 and the second inclined surfaces 14, 24) of FIG. The engine oil leaks from the second inclined surfaces 14 and 24 and the third flat surfaces 15 and 25), and the cases (1) to (4) are the same as the cases (5) and (6), respectively. 3 (a) and FIG. 3 (b) at the number of cooling cycles of about 1.5 times or more (first flat surfaces 11 and 21 and first inclined surfaces 12 and 22 apart from the knock pins A and A, respectively) Engine oil leaked from the connecting portion of the first inclined surfaces 12 and 22 and the second flat surfaces 13 and 23).

  That is, in the case of (5) and (6) above, the first jig 1 and the second jig 2 that are overlapped with each other and positioned and tightened with the knock pins C and C have the same temperature change in common. When repeatedly applied, the respective thermal expansion coefficients are different, so that the relative displacement amount along the flat surfaces 11, 21, 15, 25 based on the temperature change increases as the distance from the knock pins C, C increases. The thermal expansion directions intersect each other at the connection portion between the surfaces 13, 23 and the second inclined surfaces 14, 24 and the connection portion X between the second inclined surfaces 14, 24 and the third flat surfaces 15, 25, As a result of an increase in rubbing between the first jig 1 and the second jig 2 that are superposed, the solidified liquid gasket 4 at the connecting portion X is repeatedly subjected to a large dynamic load, and is therefore most easily broken at this portion. And therefore Since the solidified liquid gasket 4 is broken in accordance with a relatively small number of repeated cooling and heating cycles, the dynamic durability of the liquid gasket 4 in the case where relative displacement is repeatedly applied between two tightened parts. Since it can be evaluated relatively easily and quickly, it is very convenient and has a great practical value.

  In addition, in the said Example, although each surface where the 1st jig | tool 1 and the 2nd jig | tool 2 were mutually piled up was connected cyclically | annularly, these each surface is each comprised in other shapes, such as linear form. Or the bend angle at which the first inclined surface and the second inclined surface are inclined in the same direction with respect to the first flat surface or the flat surface and the inclined surface are connected to each other. It goes without saying that the same effects as those of the above-described embodiment can be obtained by appropriately changing the above or by appropriately changing the upper and lower temperatures of the cooling cycle applied according to the material of the liquid gasket.

The schematic top view in the Example of this invention. The II-II arrow longitudinal cross-sectional view of FIG. Explanatory drawing of the said Example. Explanatory drawing of the conventional method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st jig | tool 2 2nd jig | tool 3 Bolt hole 4 Liquid gasket 5 Test article 6 Space 11, 21 1st flat surface 12, 22 1st inclined surface 13, 23 2nd flat surface 14, 24 2nd inclined surface 15 , 25 3rd flat surface α Folding angle β Knock pin position angle

Claims (7)

A first flat surface substantially corresponding to the first flat surface, a first inclined surface formed continuously with the first flat surface, and a second flat surface formed continuously with the first inclined surface and parallel to the first flat surface; The coefficient of thermal expansion differs between the second inclined surface formed continuously with the second flat surface and the third flat surface formed continuously with the second inclined surface and parallel to the first flat surface. Liquid gaskets that are applied to each other by overlapping each other on each surface, positioning the first flat surfaces of the two components with a knock pin, tightening the two components, A liquid gasket evaluation method in which a temperature change common to the above two parts is repeatedly given in a solidified state. 2. The liquid gasket evaluation method according to claim 1, wherein the second inclined surface is inclined in a direction opposite to the first inclined surface. 3. The liquid gasket evaluation method according to claim 2, wherein the first flat surface and the third flat surface are located in the same plane. The angle between the first flat surface and the first inclined surface is about 135 ° to 150 ° in any one of claims 1 to 3, and the third flat surface and the second inclined surface. The liquid gasket evaluation method in which the angle formed by is about 135 ° to 150 °. 5. The ring according to claim 1, wherein each of the surfaces passes through the central portions of the first flat surface and the third flat surface and is formed in a plane symmetry perpendicular to the first flat surface. Liquid gasket evaluation method. 6. The liquid gasket evaluation method according to claim 5, wherein the two knock pins are used, and both the knock pins are symmetrically distributed at positions of about 45 degrees from the vertical plane. 7. The liquid gasket evaluation method according to claim 5, wherein fluid pressure is applied between the two parts surrounded by the liquid gasket.

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