JP7254288B2 - Creep test equipment - Google Patents

Description

The present invention relates to a creep test apparatus that imparts both torsional and bending moments to a specimen.

Patent Literature 1 discloses a test apparatus that applies a tensile load or a compressive load to a sample.
Patent Literature 2 discloses a creep test apparatus that applies a tensile load to a test piece using the weight loads of two weights.

JP 2005-249612 A JP-A-08-043281

By the way, there is a demand for a creep test apparatus that applies not only one of a torsional moment and a bending moment, but also both of them, to a test piece by the weight load of the weight. The inventors and applicants have not been able to find any prior art document disclosing such a creep test device. Therefore, the present inventor developed a creep test apparatus that imparts both a torsional moment and a bending moment to a test piece (however, this creep test apparatus is not publicly known). In this creep test apparatus, one end of a test piece is fixed, a first load transmission lever is connected to the other end of the test piece, and a second load transmission lever is transmitted from above or below the first load transmission lever. By contacting the lever and applying the weight load of the weight to the second load transmission lever, the upward or downward load is transmitted from the second load transmission lever to the first load transmission lever.

By the way, when this creep test apparatus is used, the rotational displacement of the first load transmission lever increases if the test piece is prone to creep deformation. As the rotational displacement of the first load transmission lever increases, the direction of the load transmitted from the second load transmission lever to the first load transmission lever changes. That is, the direction of the load transmitted from the second load transmission lever to the first load transmission lever is no longer perpendicular to the first load transmission lever. As a result, the torsional moment and bending moment applied to the test piece cannot be measured accurately.

Then, this invention is made|formed in view of the said situation. An object of the invention is to restore the direction of the load transmitted from the second load transmission lever to the first load transmission lever even if the direction of the load transmitted from the second load transmission lever to the first load transmission lever changes due to an increase in rotational displacement of the first load transmission lever. An object of the present invention is to provide a creep test device.

In order to solve the above problems, a creep test apparatus includes a heating furnace that accommodates a test piece and heats the test piece, and a test piece that fixes one end of the test piece and horizontally supports the axis of the test piece. A piece support portion, a one-way clutch connected to the other end of the test piece, a first load transmission lever horizontally extending from the one-way clutch in a direction orthogonal to the axis of the test piece, and the test A second load transmission lever that traverses above and below the first load transmission lever at a position deviated from one side and is supported so as to be able to swing up and down, and by applying a weight load to the second load transmission lever, a weight that presses the second load transmission lever against the first load transmission lever from above or below the first load transmission lever, and the one-way clutch is moved from the second load transmission lever to the first load transmission lever by the weight. (1) restricting the rotation of the first load transmission lever with respect to the test piece due to the load applied to the load transmission lever and allowing the rotation of the first load transmission lever in the opposite direction with respect to the test piece; Both moments are applied to the specimen by the weight load of the weight.

According to the above, since the one-way clutch is interposed between the test piece and the first load transmission lever, the first load transmission lever is rotated in the opposite direction when the rotational displacement of the first load transmission lever increases. be able to. Then, the direction of the load transmitted from the second load transmission lever to the first load transmission lever can be corrected so as to return to the direction perpendicular to the axis of the first load transmission lever.

a third load transmission lever that crosses over or under the first load transmission lever at a position on the opposite side of the second load transmission lever with respect to the test piece and that is supported so as to be able to swing up and down; a second weight that presses the third load transmission lever against the first load transmission lever from above or below the first load transmission lever by applying a weight load to the third load transmission lever. , the third load transmission lever is detachable, and when the third load transmission lever is removed, both a torsional moment and a bending moment are applied to the test piece by the weight load of the weight; A torsional moment is applied to the test piece by weight loads of the weight and the second weight when the load transmission lever is attached.

According to the embodiment of the present invention, when the rotational displacement of the first load transmission lever increases, if the first load transmission lever is rotated in the opposite direction, the load is transmitted from the second load transmission lever to the first load transmission lever. The orientation of the load can be returned to the direction perpendicular to the axis of the first load transmission lever.

FIG. 1 is a perspective view showing the creep test apparatus in the first mode as viewed from the front, upper side, and left side. FIG. 2 is an exploded perspective view showing the creep test apparatus in the first mode as viewed from the front, upper side, and left side. FIG. 3 is a perspective view showing the creep test apparatus in the first mode as seen from its rear, upper and right sides. FIG. 4 is a perspective view showing the creep test apparatus in the first mode as viewed from the front, upper side, and right side thereof. FIG. 5 is a perspective view showing the creep test apparatus in the second mode as viewed from the front, above, and left. FIG. 6 is a perspective view showing the creep test apparatus in the second mode as seen from its rear, upper and right sides.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Various limitations that are technically preferable for carrying out the present invention are attached to the embodiments described below. The scope of the present invention is not limited to the following embodiments and illustrated examples.

1. Creep Test Apparatus FIGS. 1 to 8 are perspective views of a creep test apparatus 1. FIG. 1 to 4 show a mode (hereinafter referred to as a first mode) in which both a torsional load and a bending load are applied to the test piece 2. FIG. 5 and 6 show a mode of applying a torsional load to the test piece 2 (hereinafter referred to as a second mode).

The test piece 2 has the shape of a bar, particularly a round bar or a round pipe, and the center line of the round bar or round pipe is the axis of the test piece 2 . A torsional load is a load that twists the test piece 2 around its axis. The torsional load causes the test piece 2 to generate a torsional moment. A bending load refers to a load that bends the test piece 2 in a direction perpendicular to the axis of the test piece 2 . A bending load causes the test piece 2 to generate a bending moment.

When an operator assembles the support base 80, the third load transmission lever 81, the second balance weight 84 and the second weight 90 to the creep test device 1 of the first mode, the creep test device 1 becomes the second mode. When the operator removes the third load transmission lever 81, the second balance weight 84, and the second weight 90 from the creep test device 1 of the second mode, the creep test device 1 becomes the first mode.
By changing the mode of the creep test apparatus 1 by the operator as described above, the mode of the load applied to the test piece 2 is changed.

2. First mode (bending and twisting)
1 and 2 are perspective views showing the creep test apparatus 1 in the first mode as viewed from the front, upper side, and left side thereof. FIG. 1 shows a state in which the heating furnace 30 of the creep test apparatus 1 is closed. 2 shows a state in which the heating furnace 30 of the creep test apparatus 1 in the first mode is opened and the holder 42, the shaft 43, the one-way clutch 44 and the first load transmission lever 41 are removed from the test piece 2. show. FIG. 3 is a perspective view showing the creep test apparatus 1 as seen from its rear, upper and right sides. FIG. 4 is a perspective view showing the creep test apparatus 1 in the first mode as viewed from the front, upper side, and right side thereof. In FIGS. 1 to 3, 5 and 6, illustration of the displacement sensors 71 and 72 is omitted in order to make each part of the creep test apparatus 1 easier to see.

Four height-adjustable legs 12 are attached to the lower surface of the base plate 11 . A base plate 11 is supported on the workbench by these legs 12 . By individually adjusting the height of the legs 12, the base plate 11 can be installed horizontally.

A mounting base 20 is mounted on the base plate 11 . A test piece support 21 is attached to the front surface of the mount 20 . One end of the test strip 2 is gripped by the test strip supporter 21 so as to be detachable from the test strip supporter 21 . The axis of the test piece 2 fixed to the test piece support portion 21 extends forward and backward above the base plate 11 and is parallel to the base plate 11 . The axis of the test piece 2 is horizontally supported by the test piece support 21 .

A heating furnace 30 is installed in front of the mounting base 20 on the base plate 11 . The heating furnace 30 has a lower half 31 and an upper half 32 . A lower half 31 is mounted on the base plate 11 in front of the mount 20 , and an upper half 32 is rotatably connected to the lower half 31 by a hinge 34 . When the upper half 32 is laid down on the lower half 31, the groove 31a formed in the upper surface of the lower half 31 and the groove 32a formed in the lower surface of the upper half 32 overlap vertically. A hollow is formed in the heating furnace 30 by overlapping the grooves 31a and 32a. The hollow is open at the front and rear surfaces of the heating furnace 30 , and the test piece supporting portion 21 is inserted into the hollow of the heating furnace 30 through the opening on the rear surface of the heating furnace 30 . The test piece 2 is housed in the hollow of the heating furnace 30 .

The heating furnace 30 is an electric furnace, and is provided with an electric heater and a temperature sensor. The electric heater heats the hollow of the heating furnace 30 and the test piece 2, and the temperature of the hollow of the heating furnace 30 is measured by the temperature sensor. The hollow space of the heating furnace 30 is controlled to a constant temperature by feedback control of the electric heater by the control circuit according to the temperature measured by the temperature sensor.

The other end of the test piece 2 is connected to a one-way clutch 44 via a holder 42 and a shaft 43 . Specifically, it is as follows. The other end of the test strip 2 is inserted into a tube-shaped holder 42 . The other end of the test piece 2 is fixed to the holder 42 so as to be detachable from the holder 42 . A portion of the shaft 43 is inserted into the holder 42 from the opposite side of the test piece 2 and the remaining portion of the shaft 43 protrudes forward from the holder 42 . The shaft 43 is detachably fixed to the holder 42 . A portion of the shaft 43 protruding from the holder 42 is inserted into an inner ring 44 a of a one-way clutch (cam clutch) 44 . The shaft 43 is fixed to the inner ring 44 a of the one-way clutch 44 by screwing the nut 45 onto the tip of the shaft 43 .

The one-way clutch 44 includes an inner ring 44a, an outer ring 44b provided outside the inner ring 44a so as to be rotatable relative to the inner ring 44a, and a mechanical portion (mechanism) provided between the inner ring 44a and the outer ring 44b. The part consists of, for example, cams, springs, bearings, etc.). The outer ring 44b is allowed to rotate in one direction (clockwise when viewed from the front) with respect to the inner ring 44a by the mechanism, and is restricted from rotating in the other direction (counterclockwise when viewed from the front). In FIG. 2, arrow A indicates the direction in which the outer ring 44b is allowed to rotate with respect to the inner ring 44a, and arrow B indicates the direction in which the outer ring 44b is restricted from rotating with respect to the inner ring 44a.

An outer ring 44 b of the one-way clutch 44 is fixed to the first load transmission lever 41 . Specifically, a ring 41a is provided between one end and the other end of the first load transmission lever 41, and the one-way clutch 44 is fitted into the ring 41a. is fixed to the ring 41a. Here, a key groove 44c is formed on the outer peripheral surface of the outer ring 44b, a key groove 41b is formed on the inner peripheral surface of the ring 41a, and a key 46 is fitted into the key grooves 41b and 44c, whereby the outer ring 44b is attached to the ring 41a. Fixed.

The one-way clutch 44 allows the first load transmission lever 41 to rotate in one direction (clockwise when viewed from the front) with respect to the test piece 2, and restricts rotation in the opposite direction (counterclockwise when viewed from the front). do. That is, the one-way rotational force of the first load transmission lever 41 is transmitted to the test piece 2 by the one-way clutch 44, and the reverse rotational force of the first load transmission lever 41 is transmitted to the test piece 2 by the one-way clutch 44. not.

A hollow such as a through hole is formed in the shaft 43, and flexible tubes 43a and 43b are connected to the hollow. Cooling water is supplied to the hollow of the shaft 43 through the flexible tube 43a, and the cooling water inside the hollow of the shaft 43 is discharged through the flexible tube 43b. This water-cools the shaft 43 and the one-way clutch 44 . 1 and FIGS. 3 to 6, the illustration of the flexible tubes 43a and 43b is omitted in order to make each part of the creep test apparatus 1 easier to see.

The axis of the first load transmission lever 41 is perpendicular to the axis of the test piece 2 . A roller 41 d is attached to one end of the first load transmission lever 41 , and a roller 41 e is attached to the other end of the first load transmission lever 41 . The outer peripheral surfaces of the rollers 41d and 41e are formed in a cylindrical shape with the axis of the first load transmission lever 41 as the center axis.

The first load transmission lever 41 and the one-way clutch 44 are arranged in front of the front surface of the heating furnace 30 . The holder 42 is inserted into the hollow of the heating furnace 30 through an opening on the front surface of the heating furnace 30 . A holder 42 is spaced inwardly from the hollow inner surface of the heating furnace 30 and is not supported by the heating furnace 30 .

A support base 50 is attached on the base plate 11 . The position of the support base 50 along the front-rear direction is adjustable. The support table 50 is arranged diagonally to the left of the heating furnace 30 . A second load transmission lever 51 is connected to the upper part of the support base 50 by a fulcrum 52 so as to be able to swing up and down around the fulcrum 52 . The rotation axis of the fulcrum 52 extends left and right, and the second load transmission lever 51 extends front and rear from the fulcrum 52 . The fulcrum 52 is positioned in front of the first load transmission lever 41 . A balance weight 54 is attached to the front end of the second load transmission lever 51 . The total weight of the balance weight 54 and the second load transmission lever 51 is balanced at the fulcrum 52 .

A portion of the second load transmission lever 51 from the fulcrum 52 to the rear end crosses over the left end of the first load transmission lever 41 in the front-rear direction.

A plurality of locking holes 53 are formed at intervals in the axial direction of the second load transmission lever 51 in a portion of the second load transmission lever 51 from the fulcrum 52 to the rear end. A hook 61 of a weight 60 is hooked in one of the locking holes 53 , and the weight 60 is suspended from the locking hole 53 .

By applying the weight load of the weight 60 to the second load transmission lever 51, the portion from the fulcrum 52 to the rear end of the second load transmission lever 51 is swung down. The weight load of the weight 60 presses the second load transmission lever 51 against the roller 41 d from above the left end of the first load transmission lever 41 . The second load transmission lever 51 is supported by the first load transmission lever 41 from below. In the second load transmission lever 51, the moment of the supporting force by the first load transmission lever 41 and the moment of the load of the weight 60 are balanced. Further, a downward load is applied from the second load transmission lever 51 to the left end of the first load transmission lever 41 by the weight load of the weight 60 at the contact point of the outer peripheral surface of the second load transmission lever 51 and the roller 41d. The direction of the load is substantially perpendicular to the axis of the first load transmission lever 41 . This is because the second load transmission lever 51 is in contact with the cylindrical outer peripheral surface of the roller 41d. The load applied from the second load transmission lever 51 to the left end of the first load transmission lever 41 causes the test piece 2 to generate both a bending moment and a torsional moment. By replacing the weight 60 suspended from one of the locking holes 53 with another locking hole 53, the magnitude of the downward load applied from the second load transmission lever 51 to the left end of the first load transmission lever 41 can be increased. changes.

As shown in FIG. 4, the downward displacement of the other end of the test piece 2 due to the bending moment can be measured by a dial gauge type displacement sensor 71 . The downward displacement of the contact portion between the first load transmission lever 41 and the second load transmission lever 51 due to the torsional deformation of the test piece 2 can be measured by the dial gauge type displacement sensor 72 .

A creep test method using the creep test apparatus 1 of the first embodiment will be described below.

First, the heating furnace 30 is opened by raising the upper half 32 from the lower half 31 . Then, the test piece 2 is inserted into the groove 31 a of the lower half body 31 and one end of the test piece 2 is attached to the test piece support portion 21 . A holder 42 is attached to the other end of the test piece 2 , a shaft 43 is attached to the holder 42 , an inner ring 44 a of a one-way clutch 44 is attached to the shaft 43 , and an outer ring 44 b of the one-way clutch 44 is attached to the shaft 43 . At this time, the axis of the first load transmission lever 41 is made horizontal.

Next, the heating furnace 30 is closed by laying down the upper half 32 onto the lower half 31 . Then, the test piece 2 is accommodated in the hollow of the heating furnace 30 .

Next, displacement sensors 71 and 72 are installed. Next, the power of the heating furnace 30 is turned on to heat the hollow of the heating furnace 30 to a high temperature and keep the temperature of the hollow of the heating furnace 30 at a predetermined temperature.

Next, the hook 61 is hooked to one of the locking holes 53 and the weight 60 is suspended from the locking hole 53 . Then, the portion from the fulcrum 52 to the rear end of the second load transmission lever 51 is swung down by the weight load of the weight 60, so that the second load transmission lever 51 moves from above the left end of the first load transmission lever 41 to the roller 41d. be pushed. A torsional moment and a bending moment are generated in the test piece 2 by the weight load of the weight 60 . Here, since the first load transmission lever 41 is horizontal at the initial stage of the creep test, the direction of the load transmitted from the second load transmission lever 51 to the first load transmission lever 41 is is almost vertical.
Next, the zero points of the displacement sensors 71 and 72 are set.

While the test piece 2 is heated by the heating furnace 30, a torsional moment and a bending moment are applied to the test piece 2, so that the test piece 2 undergoes a creep phenomenon. That is, the torsional and bending deformations of the test piece 2 increase with the passage of time. Therefore, the downward displacement of the other end of the test piece 2 is continuously, intermittently or intermittently measured by the displacement sensor 71 during the creep test. The measurement result by the displacement sensor 71 can be converted into the bending deformation amount of the test piece 2 .
During the creep test, the downward displacement of the contact portion between the first load transmission lever 41 and the second load transmission lever 51 is continuously, intermittently or intermittently measured by the displacement sensor 72 . The measurement result by the displacement sensor 72 can be converted into the torsional deformation amount of the test piece 2 .

As the rotational displacement of the first load transmission lever 41 increases due to the creep phenomenon of the test piece 2, the direction of the load transmitted from the second load transmission lever 51 to the first load transmission lever 41 gradually changes. When the rotational displacement of the first load transmission lever 41 increases while the creep test is continuing, the user resists the weight load of the weight 60 and rotates it clockwise (see arrow A in FIG. 2) when viewed from the front. By rotating the first load transmission lever 41, the first load transmission lever 41 can be returned horizontally. This is because the one-way clutch 44 is provided. By returning the first load transmission lever 41, the direction of the load transmitted from the second load transmission lever 51 to the first load transmission lever 41 can be corrected in a direction perpendicular to the axis of the first load transmission lever 41. .

3. Second mode (torsion)
FIG. 5 is a perspective view showing the creep test apparatus 1 in the second mode as viewed from the front, above, and left. FIG. 6 is a perspective view showing the creep test apparatus 1 in the second mode as seen from its rear, upper and right sides.

A support base 80 is detachably mounted on the base plate 11 . The position of the support base 80 along the front-rear direction is adjustable. The support base 80 is arranged diagonally to the right of the heating furnace 30 . A third load transmission lever 81 is connected to the upper portion of the support base 80 by a fulcrum 82 so as to be able to swing up and down around the fulcrum 82 . The rotation axis of the fulcrum 82 extends left and right, and the third load transmission lever 81 extends back and forth from the fulcrum 82 . The fulcrum 82 is positioned behind the first load transmission lever 41 . The fulcrum 82 is positioned lower than the fulcrum 52 .

A second balance weight 84 is attached to the front end of the third load transmission lever 81 . The overall weight of the second balance weight 84 and the third load transmission lever 81 is balanced at the fulcrum 82 .

A portion of the third load transmission lever 81 from the fulcrum 82 to the front end crosses under the right end of the first load transmission lever 41 in the front-rear direction.

A plurality of locking holes 83 are formed at intervals in the axial direction of the third load transmission lever 81 in a portion from the fulcrum 82 to the rear end of the third load transmission lever 81 . A hook 91 of a second weight 90 is hooked in one of the locking holes 83 , and the second weight 90 is suspended from the locking hole 83 .

When the weight load of the second weight 90 is applied to the third load transmission lever 81, the portion from the fulcrum 82 to the rear end of the third load transmission lever 81 swings down, and the third load transmission lever 81 swings down from the fulcrum 82. The part up to the front end of is swung up. The weight load of the second weight 90 presses the third load transmission lever 81 against the roller 41 e from below the right end of the first load transmission lever 41 . A third load transmission lever 81 is supported by a roller 41e from above. In the third load transmission lever 81, the moment of the supporting force by the first load transmission lever 41 and the moment of the load of the second weight 90 are balanced. Further, at the contact point of the third load transmission lever 81 and the roller 41 e , an upward load is applied from the third load transmission lever 81 to the right end of the first load transmission lever 41 by the weight load of the second weight 90 . The direction of the load is almost parallel to the vertical direction. Both the upward load and the downward load applied from the second load transmission lever 51 to the first load transmission lever 41 generate a torsional moment in the test piece 2 .

A creep test method using the creep test apparatus 1 of the second embodiment will be described below.

A holder 42 , a shaft 43 , a one-way clutch 44 and a first load transmission lever 41 are attached to the other end of the test piece 2 in the same manner as in the first mode. Also, the test piece 2 is housed in the heating furnace 30 and the test piece support portion 21 is attached to one end of the test piece 2 .
Next, displacement sensors 71 and 72 are installed.
Next, the power of the heating furnace 30 is turned on to keep the hollow temperature of the heating furnace 30 at a high temperature.
Next, the hook 61 is hooked to one of the locking holes 53 and the weight 60 is suspended from the locking hole 53 . Then, the portion from the fulcrum 52 to the rear end of the second load transmission lever 51 is swung down by the weight load of the weight 60, so that the second load transmission lever 51 moves from above the left end of the first load transmission lever 41 to the roller 41d. be pushed.

A hook 91 is hooked to one of the locking holes 83 to suspend the second weight 90 from the locking hole 83 . Then, since the portion from the fulcrum 82 to the front end of the third load transmission lever 81 is swung up by the weight load of the second weight 90, the third load transmission lever 81 moves from below the right end of the first load transmission lever 41 to the roller 41e. be pushed.
A torsional moment is generated in the test piece 2 due to the weight load of the weights 60 and 90 .
Next, the zero points of the displacement sensors 71 and 72 are set.

A torsional moment is applied to the test piece 2 while the test piece 2 is being heated by the heating furnace 30 , and a creep phenomenon occurs in the test piece 2 . That is, the torsional deformation of the test piece 2 increases with the lapse of time. During the creep test, the downward displacement of the contact portion between the first load transmission lever 41 and the second load transmission lever 51 is continuously, intermittently or intermittently measured by the displacement sensor 72 . The measurement result by the displacement sensor 72 can be converted into the torsional deformation amount of the test piece 2 .

When the rotational displacement of the first load transmission lever 41 increases while the creep test is continuing, the user resists the weight load of the weights 60 and 90 and rotates clockwise when viewed from the front (see arrow A in FIG. 2). , the first load transmission lever 41 can be rotated to return the first load transmission lever 41 horizontally. By returning the first load transmission lever 41 horizontally, the direction of the load transmitted from the load transmission levers 51 and 81 to the first load transmission lever 41 is corrected in a direction perpendicular to the axis of the first load transmission lever 41. can be done.

5. Advantageous Effect (1) When the creep test apparatus 1 of the first aspect is used, both a torsional moment and a bending moment are generated in the test piece 2 due to the weight load of the weight 60 . Since both the torsional moment and the bending moment are generated in the test piece 2 by using the potential energy of the weight 60 without using hydraulic pressure, pneumatic pressure and electric power, the creep test apparatus 1 of the first aspect has a simple and compact structure. have

(2) If the creep test apparatus 1 of the second aspect is used, a torsional moment is generated in the test piece 2 due to the weight load of the weights 60 and 90 . Since a power source for generating a torsional moment is not used, the creep test device 1 of the second aspect also has a simple and compact structure.

(3) If the rotational displacement of the first load transmission lever 41 becomes large during the creep test, rotate the first load transmission lever 41 clockwise as viewed from the front so that the first load transmission lever 41 is horizontal. can be returned. By returning the first load transmission lever 41 , the direction of the load transmitted from the load transmission levers 51 and 81 to the first load transmission lever 41 can be returned to the direction perpendicular to the axis of the first load transmission lever 41 .

(4) The one-way clutch 44 can be water-cooled. Therefore, the temperature of the one-way clutch 44 does not exceed the allowable temperature or the heat resistant temperature.

(5) The extension direction of the second load transmission lever 51 intersects the extension direction of the first load transmission lever 41, and the second load transmission lever 51 moves back and forth above the left end of the first load transmission lever 41. crossing. Therefore, the linear distance from the weight 60 to the holder 42 is short, and the creep test apparatus 1 of the first mode is compact. The distance from the weight 60 to the holder 42 along the first load transmission lever 41 and the second load transmission lever 51 is long, and the weight load of the weight 60 acts on the test piece 2 .
Similarly, since the third load transmission lever 81 crosses under the right end of the first load transmission lever 41 in the front-rear direction, the creep test apparatus 1 of the second embodiment is compact, and the weight load of the weight 90 causes a large load. acts on the specimen 2.

(6) The creep test apparatus 1 can be used for both torsional and bending creep tests and torsional creep tests by simply attaching and detaching the support base 80, the third load transmission lever 81, the second balance weight 84, and the second weight 90. can do.

(7) The load transmission levers 41 , 51 , the support base 80 , the second balance weight 84 and the second weight 90 are arranged outside the heating furnace 30 . Therefore, they are not affected by heat. In addition, no creep phenomenon occurs in the load transmission levers 41 and 51 and the support base 80 .

(8) Since the test piece 2 is housed in the heating furnace 30, a torsional moment (or both a torsional moment and a bending moment) is applied to the test piece 2 while the test piece 2 is heated to a predetermined temperature. can be done. Therefore, it is possible to evaluate the creep phenomenon of the test piece 2 in a high temperature environment. For example, if the test piece 2 is assumed to be a cast steel welded portion of a steam turbine reheat stop valve, the test piece 2 can reproduce the high-temperature environment and load environment that the cast steel welded portion receives.

6. Modification In the first aspect, the fulcrum 52 may be positioned behind and below the first load transmission lever 41 . In this case, by reversing the one-way clutch 44, the one-way clutch 44 allows the first load transmission lever 41 to rotate counterclockwise (see arrow B in FIG. 2) with respect to the test piece 2. , clockwise (see arrow A in FIG. 2)). Further, a portion of the second load transmission lever 51 from the fulcrum 52 to the front end crosses under the left end of the first load transmission lever 41 in the front-rear direction. Therefore, the second load transmission lever 51 is pressed against the roller 41d from below the left end of the first load transmission lever 41 by the weight load of the weight 60, so that the upward load is transmitted from the second load transmission lever 51 to the first load transmission. It is given to the lever 41 . The upward load causes the test piece 2 to generate both a bending moment and a torsional moment.

In the second mode, the fulcrum 52 may be located behind and below the first load transmission lever 41 and the fulcrum 82 may be located above and in front of the first load transmission lever 41 . In this case, by reversing the one-way clutch 44, the one-way clutch 44 allows the first load transmission lever 41 to rotate counterclockwise (see arrow B in FIG. 2) with respect to the test piece 2. , clockwise (see arrow A in FIG. 2)). Further, a portion of the second load transmission lever 51 from the fulcrum 52 to the front end crosses under the left end of the first load transmission lever 41 in the front-rear direction. Therefore, the second load transmission lever 51 is pressed against the left end of the roller 41 d from below the left end of the first load transmission lever 41 by the weight load of the weight 60 . It is applied to the load transmission lever 41 . A portion of the third load transmission lever 81 from the fulcrum 82 to the rear end crosses over the right end of the first load transmission lever 41 in the front-rear direction. Therefore, the weight load of the second weight 90 presses the third load transmission lever 81 against the roller 41 e from the right end of the first load transmission lever 41 , thereby transferring the downward load from the third load transmission lever 81 to the first load transmission lever 81 . It is applied to the load transmission lever 41 . Both the upward load and the downward load generate a torsional moment in the specimen 2 .

Instead of providing the rollers 41d and 41e, the outer peripheral surface of the first load transmission lever 41 may be shaped like a cylindrical surface.

DESCRIPTION OF SYMBOLS 1... Creep test apparatus 2... Test piece 21... Test piece support part 30... Heating furnace 44... One-way clutch 41... First load transmission lever 51... Second load transmission lever 60... Weight 81... Third load transmission lever 90... second weight

Claims (2)

a heating furnace that houses a test piece and heats the test piece;
a test piece support that fixes one end of the test piece and horizontally supports the axis of the test piece;
a one-way clutch connected to the other end of the test piece;
a first load transmission lever extending horizontally from the one-way clutch in a direction orthogonal to the axis of the test piece;
a second load transmission lever crossing above and below the first load transmission lever at a position deviated from the test piece and supported so as to be able to swing up and down;
a weight that presses the second load transmission lever against the first load transmission lever from above or below by applying a weight load to the second load transmission lever;
The one-way clutch regulates the rotation of the first load transmission lever with respect to the test piece due to the load applied from the second load transmission lever to the first load transmission lever by the weight, and the allowing the first load transmission lever to rotate in the opposite direction,
A creep test apparatus in which both a torsional moment and a bending moment are applied to the specimen by the weight load of the weight. a third load transmission lever that traverses above or below the first load transmission lever at a position on the opposite side of the second load transmission lever with respect to the test piece and is supported so as to be able to swing up and down;
a second weight that presses the third load transmission lever against the first load transmission lever from above or below by applying a weight load to the third load transmission lever;
further comprising
the third load transmission lever is detachable,
applying both a torsional moment and a bending moment to the test piece by the weight load of the weight when the third load transmission lever is released;
2. The creep test apparatus according to claim 1, wherein a torsional moment is applied to said test piece by weight loads of said weight and said second weight when said third load transmission lever is attached.

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