JP3352866B2 - Bending test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending test apparatus and, more particularly, to a bending test apparatus suitable for performing a bending test on a circular specimen such as a cylinder or a cylinder such as a large steel pipe.

[0002]

2. Description of the Related Art Various large-diameter and long steel pipes are used in civil engineering and construction. A bending test is performed to confirm that these large steel pipes have a predetermined strength. A conventional bending test apparatus for large-sized steel pipes includes a pair of supports for supporting the lower surfaces at both ends of the steel pipe, a column, and a load mechanism suspended from the column to apply a bending load to the central portion of the steel pipe from above. Consists of The large steel pipe is placed on a pair of supports while penetrating through the inside of the gate post, and then subjected to a bending test by applying a bending load to a central portion by a load mechanism.

[0003]

However, in the above-described conventional bending test apparatus, when the size and weight of the test piece are large, such as a large steel pipe, the test piece is moved by using a crane and a chain block. It must be carried in and out of the bending test equipment, and the work of placing the specimen on the support under the portal and using the crane and chain block, etc., and taking it out therefrom requires extremely skill. In addition, there is a problem that a great deal of labor and time are required. Therefore, an object of the present invention is to provide a bending test apparatus that can easily carry in and carry out a bending test apparatus even with a large-sized specimen.

[0004]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a base, and a pair of end fulcrum mounts attached to the base at a predetermined distance from each other. A central fulcrum mount attached to the central portion of the base so as to be located between the pair of end fulcrum mounts, and a load attached to the central portion of the base and moving the central fulcrum mount up and down Mechanism, and a specimen support means attached to the upper end of each of the pair of end fulcrum mounts and the central fulcrum mount to support a specimen, and each of the specimen support means includes the specimen. It is composed of a placing part to be placed and a lid part covering the upper part of the specimen placed on the placing part. The lid part places the specimen on the placing part from above. It is characterized by being freely openable so that The specimen is placed on the placing part from above with the lid part opened. Thereafter, the lid is closed, whereby each specimen support means supports the specimen from above and below. A loading mechanism moves the center fulcrum base up and down, thereby applying a bending load to the specimen. Thereafter, the lid is opened and the specimen is lifted from the mounting part and carried out.

As described above, the pair of end fulcrum mounts, the central fulcrum mount, and the load mechanism are each mounted on the base, so that the column is not required. Therefore, the test specimen is mounted from above with the lid open. It can be easily placed on the placing section, and can be easily lifted from the placing section. Therefore, the loading and unloading of the test specimen into and out of the bending test apparatus becomes extremely easy, and the loading and unloading operations can be performed by unskilled workers in a short time and with a small amount of labor.

According to a second aspect of the present invention, in the bending test apparatus according to the first aspect, each of the specimen supporting means has substantially the same structure as each other. The component parts of the specimen support means can be shared, and the manufacturing cost can be reduced.

According to a third aspect of the present invention, in the bending test apparatus according to the first aspect, the specimen has a cylindrical or cylindrical shape, the lid is hinged at one end, and the opening is performed by a turning operation. It is characterized by being performed. The opening of the lid is performed by a swiveling operation, and loading and unloading of a cylindrical or cylindrical specimen can be performed extremely easily.

According to a fourth aspect of the present invention, in the bending test apparatus according to the first aspect, the mounting portion has a mounting surface on which the specimen is mounted, and is a fastening member movable in the vertical direction. And a specimen fastening actuator for driving the fastening member upward to fasten the specimen between the fastening member and the lid.
After the lid is closed, the tightening member tightens the specimen with the lid by driving the specimen tightening actuator to firmly support the specimen.

According to a fifth aspect of the present invention, in the bending test apparatus according to the fourth aspect, the actuator for tightening the specimen includes a hydraulic cylinder, an output shaft horizontally moved by the hydraulic cylinder, A wedge member connected to the output shaft and having a wedge surface, wherein the fastening member has a wedge surface engaged with the wedge surface of the wedge member, and the test specimen is moved by moving the output shaft in a horizontal direction. It is characterized by tightening.

Since the specimen is tightened by the wedge action, the specimen can be firmly tightened even if a relatively small hydraulic cylinder is used.

According to a sixth aspect of the present invention, in the bending test apparatus according to the first aspect, a pair of the central fulcrum mounts is provided, and the pair of the central fulcrum mounts is pin-connected to the common load mechanism. It is characterized by the following. A four-point bending test is performed with a pair of end fulcrum mounts and a pair of central fulcrum mounts.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a bending test apparatus according to the present invention will be described below with reference to FIGS. FIGS. 1, 2 and 3 show a front view, a side view and a plan view, respectively, of an embodiment of a bending test apparatus according to the present invention. ing. This base 2
A pair of guide grooves 3, 3 shown in FIG. Further, a pair of end fulcrum mounts 4, 4 are arranged on the base 2 at predetermined intervals. Each end fulcrum base 4 is slidable on the base 2 by being guided by a pair of guide grooves 3 and is fixed at an arbitrary position by a plurality of bolts 5 as shown at the right end of FIG. You.

An actuator 6 for applying a bending load is built in the center of the base 2 in the longitudinal direction, and a piston connecting member 8 is attached to a tip of a piston rod 7 of the actuator 6.
Are connected. A pair of central fulcrum mounts 9 and 9 are pin-connected to the piston connecting member 8 by pins 10, whereby the pair of central fulcrum mounts 9 and 9 are
It can swing about 0 as the center of rotation. In addition, the actuator 6, the piston rod 7, and the piston connecting member 8 constitute a load mechanism. Each of the pair of end fulcrum mounts 4 and 4 and the pair of central fulcrum mounts 9 and 9 has an upper end,
Specimen support means 11 having the same structure are attached to each other. These specimen support means 11 firmly support the specimen indicated by the imaginary line in FIGS. 1, 2 and 3, that is, the steel pipe S.

Next, the structure of each specimen support means 11 will be described in detail. 4 to 6 show the specimen support means 11 attached to the end fulcrum 4, but the specimen support means 11 attached to the central fulcrum 9 has the same structure. In FIGS. 4 to 6, the specimen support means 1
1 can be roughly divided into a pair of bearing mechanisms 12 spaced apart from each other, and a specimen mounting portion 13 supported by the pair of bearing mechanisms 12 so as to be swingable in the bending direction of the steel pipe specimen S.
And a cover 14 that covers the steel pipe specimen S placed on the placement section 13.

Each of the bearing mechanisms 12 includes a mount 15 fixed to the end fulcrum 4, a leaf spring 16 mounted on the mount 15, and a plurality of springs on the upper surface of the leaf spring 16. In the example, it comprises a bearing 18 attached by three bolts 17. The mounting portion 13 has a semicircular concave portion 19 for mounting and housing the steel pipe specimen S, and the semicircular concave portion 19 is defined in a shape corresponding to the outer peripheral surface of the steel pipe specimen S. The mounting portion 13 is composed of a swinging body 20 and a fastening means 21 connected to the swinging body 20. As shown in FIG. 5, the tightening means 21 includes a tightening member 22, a wedge member 23, and a hydraulic cylinder 24 for tightening.
And a hydraulic cylinder 24 for tightening which penetrates the swinging body 20.
Output rod 25, and this output rod 25 and wedge member 23
And a connecting member 26 for connecting the two. The connecting member 26 is connected to the wedge member 23 and the output rod 25 by bolts 27 and 28, respectively.

The fastening member 22 has an upper surface formed as a mounting surface 22a and a lower surface formed as a tapered surface 22b. The mounting surface 22 a is a circumferential concave surface corresponding to the outer circumferential surface of the steel pipe specimen S, and the tapered surface 22 b is engaged with the wedge surface of the wedge member 23. When the hydraulic cylinder 24 drives the output shaft 25 in the direction of the arrow B, the wedge member 23 pushes the fastening member 22 upward by a wedge action. Further, as shown in FIG. 4, swinging shafts 20 a are provided on the swinging body 20 so as to project right and left, and these swinging shafts 20 a are supported by bearings 18. Thus, the mounting portion 13 is configured to be swingable in the bending direction of the steel pipe specimen S.

The lid 14 is hinged at one end to the upper portion of the mounting portion 13 by a fixing pin 29, and
Is locked by a detachable pin 30. The lower surface of the lid part 14 is formed in a circumferential concave surface corresponding to the outer peripheral surface of the steel pipe specimen S, and a suspension bolt 31 is projected from the upper surface of the lid part 14. By removing the detachable pin 30, the cover 14 is moved about 180 degrees in the direction of arrow A in FIG.
It is rotatable, and by this rotation, the upper part of the circular concave portion 19 of the mounting portion 13 is opened.

Next, the operation of this embodiment will be described. First, the pair of end fulcrum mounts 4 and 4 are slid along the guide groove 3 to set the interval between the pair of end fulcrum mounts 4 and 4 to the steel pipe specimen S.
Adjust according to the length of. After this adjustment, the pair of end fulcrum mounts 4 and 4 are fixed by bolts 5 respectively. Next, the actuator 6 is driven to adjust the height of the pair of central fulcrum mounts 9, 9, and the height of the specimen supporting means 11 of the central fulcrum mounts 9, 9 is adjusted to the height of the end fulcrum mounts 4, 4. Adjust to the height of the specimen support means 11.

Thereafter, the detachable pin 30 of the lid 14 is removed, and the lid 14 is lifted in the direction of arrow A by using the suspension bolts 31 and is turned around the fixing pin 29. Thus,
The upper part of the concave portion 19 of the specimen mounting portion 13 is opened. At this time, the hydraulic cylinder 24 of each specimen mounting part 13 moves the output rod 25 in the direction opposite to the arrow B to loosen the fastening member 22.

In this state, the steel pipe specimen S is suspended by a crane, a chain block and the like, carried in, lowered from above, and placed on the mounting portion 1 of each specimen support means 11.
3 is placed. Since this bending test apparatus does not have a gate post or the like, the steel tube specimen S is suspended from above by a crane, a chain block, or the like.
3 can be placed.

After this mounting, the lid 14 is closed so as to cover the steel pipe specimen S, and then the detachable pin 30 is inserted to lock the lid 14 to the mounting portion 13. Thereafter, the hydraulic cylinder 24 of each specimen mounting section 13 is operated to output the output rod 2.
5 is moved in the direction of arrow B. Thereby, the wedge member 23
Pushes the fastening member 22 upward by its wedge action,
The steel pipe specimen S is tightly supported between the lid 14 and the lid. Thereafter, the actuator 6 is driven to move the center fulcrum mount 9 upward or downward, and a bending moment is applied to the steel pipe specimen S. Thus, the steel pipe specimen S
Are subjected to a four-point bending test. The four specimen support means 11 are configured to be swingable in the bending direction of the steel pipe specimen S by the action of the leaf spring 16 of the bearing mechanism 12, so that the distance between the fulcrums of the specimen S is constant. Is held.

After the test, the steel pipe specimen S is taken out from each specimen support means 11 and carried out by the operation opposite to the above operation. In the above embodiment, a four-point bending test apparatus is used. However, a three-point bending test apparatus may be used by using only one central fulcrum mount 9. Further, the present invention is suitable for a bending test apparatus for a columnar specimen having a circular cross section such as a steel pipe, but is not limited to this, and can be applied to a bending test apparatus for a columnar specimen having an arbitrary cross section.

[0023]

As is apparent from the above description, according to the present invention, a pair of end fulcrum mounts, a central fulcrum mount, and a load mechanism are mounted on the bases, respectively. The specimen can be easily placed on the placing portion from above with the lid open, and can be easily lifted from the placing portion. Therefore, the loading and unloading of the specimen into and out of the bending test apparatus becomes extremely easy, and the loading and unloading operations can be performed by unskilled workers in a short time and with a small amount of labor. Can be performed very efficiently.

[Brief description of the drawings]

FIG. 1 is a front view partially showing a cross section of a first embodiment of a bending test apparatus according to the present invention.

FIG. 2 is a side view showing the embodiment in a partial cross section.

FIG. 3 is a plan view showing the embodiment.

FIG. 4 is a side view taken along the line IV-IV in FIG. 1;

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is a plan view of FIG. 4;

[Explanation of symbols]

 2 Base 4 End fulcrum 6, 7, 8 Loading mechanism 9 Center fulcrum 11 Specimen support means 13 Mounting part 14 Lid

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01N 3/20

Claims (6)

(57) [Claims] 1. A base, a pair of end fulcrum mounts attached to the base at a predetermined distance from each other, and a central portion of the base positioned between the pair of end fulcrum mounts. A central fulcrum mount attached to the base, a load mechanism attached to the center of the base to move the central fulcrum mount up and down, and upper ends of each of the pair of end fulcrum mounts and the central fulcrum mount A specimen support means attached to the specimen for supporting the specimen, wherein each of the specimen support means is provided with a mounting part for mounting the specimen and an upper part of the specimen mounted on the mounting part. And a lid for covering the test piece, wherein the lid is freely openable so that the specimen can be placed on the placement section from above. 2. The bending test apparatus according to claim 1, wherein each of said specimen supporting means has substantially the same structure as each other. 3. The bending test apparatus according to claim 1, wherein the specimen has a cylindrical or cylindrical shape, the lid is hinged at one end, and the opening is performed by a turning operation. 4. The mounting part has a mounting surface on which the specimen is mounted, and is capable of moving in a vertical direction, and a driving member that drives the tightening member upward to move the tightening member. The bending test apparatus according to claim 1, further comprising: a specimen fastening actuator for fastening the specimen between the lid and the lid. 5. An actuator for tightening a specimen, comprising: a hydraulic cylinder; an output shaft horizontally moved by the hydraulic cylinder; and a wedge member connected to the output shaft and having a wedge surface. 5. The device according to claim 4, wherein the tightening member has a wedge surface which engages with a wedge surface of the wedge member, and tightens the specimen by moving the output shaft in a horizontal direction.
4. The bending test apparatus according to 1. 6. The bending test apparatus according to claim 1, wherein a pair of said central fulcrum mounts is provided, and said pair of central fulcrum mounts are pin-connected to said common load mechanism.