JPH0954028A - Material testing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct a tensile test and a compression test within the same working space by installing pressure plates without removing upper and lower clamps for use in tensile test. SOLUTION: During a tensile test, a test piece is gripped by upper and lower clamps 7U, 7L, and a double action cylinder 8 is contracted to drive and separate the lower clamp 7L from the upper clamp 7U. A tensile load works on the test piece. During a compression test, pressure plate mounting blocks 21, 31 are fitted into notches 71 in the upper and lower clamps 7U, 7L, and pressure plates 22, 32 are installed on the mounting blocks 21, 31. The double acting cylinder 8 is extended to bring the lower clamp 7L close to the upper clamp 7U to apply a compressive load to the test piece between the upper and lower pressure plates 22, 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material testing machine capable of performing a tensile test, a compression test or a bending test.

[0002]

2. Description of the Related Art FIGS. 8 and 9 show an example of a conventionally known material testing machine. The material testing machine shown in FIG. 8 includes a ram cylinder device 61 for loading a test piece and a pair of screw rods 6 standing upright on the side of the ram cylinder device 61.
2, a lower cross head 63 held by the pair of screw rods 62 via a rotating nut so as to be able to move up and down, a table 64 moved up and down by a ram cylinder device 61, and a support 65 standing upright on the table 64. The upper crosshead 66 held by the upper crosshead 66, the lower grip 67 provided on the lower crosshead 63, and the upper grip 68 provided on the upper crosshead 66.

The material testing machine shown in FIG. 9 has a table 71.
And a cross head 7 that moves up and down by the rotation of screw rods (not shown) that are erected on the left and right of the table 71 and penetrate the table 71
2 and the upper grip 73 suspended from the crosshead 72
And a lower grip 74 installed on the table 71.

[0004]

In the conventional material testing machine shown in FIG. 8, when performing a tensile test, the test piece is held by the upper and lower openable grips 67, 68, and the ram cylinder device is used. A tensile load is applied to the test piece by extending 61 and raising the upper crosshead 66. On the other hand, when performing a compression test, the upper platen 69 is set to the lower crosshead 63.
The lower platen 70 is installed on the upper surface of the table 62, and a compressive load is applied to the test piece between the platens 69 and 70. In this material testing machine, the test space is different between the tensile test and the compression test, and improvement in workability is desired.

In the conventional material testing machine shown in FIG. 9,
When performing a tensile test, the upper and lower openable grips 7
The test piece is gripped by 3,74 and the cross head 72 is raised to apply a tensile load to the test piece. On the other hand, when performing a compression test, the upper and lower grips 73 and 74 are replaced with a platen, the crosshead 72 is lowered, and a compressive load is applied to the test piece between the upper and lower platens. Therefore, in the tensile test and the compression test, the work of exchanging the grip and the platen is indispensable, and improvement of workability is desired.

The object of the present invention is to perform tensile test, compression test,
Or bending test can be done in the same test space,
An object of the present invention is to provide a material testing machine with improved workability by installing a test piece mounting jig such as a platen on the grip without removing the grip for the tensile test during the compression test or bending test.

[0007]

FIG. 1 shows an embodiment of the present invention.
6 will be described in association with FIG. One gripping tool 7U and a pair of gripping teeth 7e that are provided so as to face the first gripping tool 7U and are held in contact with each other to grip the test piece are provided. The second grip 7L including the mounting portion 71
And during the tensile test, the first and second grips 7
While holding the test piece with U and 7L to drive both grips away from each other and apply a tensile load to the test piece, at the time of a test such as a compression test different from the tensile test, the first and second grippers 7U and 7L are It is characterized in that it is provided with a load mechanism 8 which is driven to approach and applies a compressive load to the test piece by means of a test piece mounting jig 20, 30 such as a platen mounted on the mounting portion of each grip.

During the tensile test, the test piece is held by the first and second grippers 7U and 7L, and the load mechanism 8 drives the first and second grippers 7U and 7L to move away from each other. During the compression test and bending test, the first and second grips 7
The jigs 20 and 30 such as a platen are attached to the jig mounting portions 71 of U and 7L.
Is installed, the jigs 20 and 30 are brought close to each other by the load mechanism 8, and a compressive load is applied to the test piece.

Incidentally, in the section of means and action for solving the above-mentioned problems for explaining the constitution of the present invention, the drawings of the embodiments are used for the purpose of making the present invention easy to understand. It is not limited to this form.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a material testing machine according to the present invention will be described with reference to FIGS. As shown in FIG. 1, the material testing machine includes a base 1, two pillars 2 and 3 which are erected on the base 1 in pairs, and the axial directions of the two pillars 2 and 3. A crosshead 5 that is movably engaged in the vertical direction, a crosshead hydraulic clamp 4 that clamps the crosshead 5 at an arbitrary height of the columns 2 and 3, and a crosshead lifting cylinder that vertically drives the crosshead 5. The device 6, the upper grip 7U on the fixed side attached to the crosshead 5, the returning cylinder 8 as a load mechanism provided on the base 1, and the piston rod 9 of the returning cylinder 8.
A lower grip 7L on the movable side attached to the tip (upper end) 9a of the
The U and the lower grip 7L grip the test piece, and the return cylinder 8 drives the lower grip 7L in the axial direction of the columns 2 and 3 to apply a load to the test piece.

As shown in FIG. 2, the upper grip 7U and the lower grip 7L each have a U-shaped main body 7a, a pair of pistons 7b slidably provided on each main body 7a, and the main body 7a. A cylinder 7c provided with an oil pressure for opening and closing a piston 7b provided therein, a holder 7d fitted and attached to the tip of the piston 7b, and a pressing plate fitted to the tip of the holder 7d. 7f has a gripping tooth 7e that is prevented from falling off, and is configured to supply and discharge hydraulic pressure to and from the cylinder 7c to open and close the gripping tooth 7e to grip the test piece. 1 and 2, the lower grip 7
Guide rods 12 and 13 project from left and right side surfaces of L, and the lower grip 7L moves up and down while sliding rollers provided at the tips of the guide rods 12 and 13 along the columns 2 and 3.

When performing a tensile test with a material testing machine having such a fluid open / close type grip, the cylinder 7c is used.
The hydraulic pressure is supplied from the bottom chamber to close the left and right pistons 7b to clamp the test piece. When the return cylinder 8 contracts, a tensile load acts on the test piece. When oil is supplied to the rod chamber of the cylinder 7c, the left and right pistons 7b are opened, the grip of the test piece is released, and the test piece can be removed.

When performing the compression test, as shown in FIG. 3, the upper and lower platens 20 and 30 are installed on the surfaces of the upper and lower grips 7U and 7L which face each other, and the test pieces are compressed between the two plates 20 and 30. Apply a load. Upper and lower platen device 2 according to FIGS.
0 and 30 will be described.

FIG. 4 is an enlarged view of the upper and lower platen device, FIG. 5 is a plan view of the lower platen device, and FIG. 6 is a plan view of the lower grip. A lower platen 32 is installed on the upper surface of the lower grip 7L via a lower platen mount 31. As shown in FIG. 6, a cutout recess 71 into which the boss 31a on the bottom surface of the mounting base 31 fits is formed on the upper surface of the lower grip 7L to center the mounting base 31 with respect to the load shaft. The mount 31 is fixed to the lower grip 7L with bolts 33, and a lower platen 32 centered by a centering pin 34 is placed on the upper surface of the mount 31.

FIG. 7 (a) is an enlarged view of the fitting portion of the boss 31a of the mounting base 31, and a relief R is provided at the root of the boss 31a.
The portion 31b is formed on the entire circumference, and the chamfered portion 31 is formed at the tip portion.
c is formed. The base portion of the boss 31a is shown in FIG.
Assuming that the corner R portion 31b ′ as shown in FIG.
As shown in (c), the boss 31a 'is cut out to form the recess 71
The R plate 31b 'comes into contact with the edge of the cutout recess 71 to form a gap SA during the fitting into, and the lower platen 31' becomes unstable. In that respect, the clearance R portion 31b as shown in FIG. 7A does not form the clearance SA, and the lower platen 31 is stably installed.

On the other hand, as shown in FIG. 4, the upper grip 7U
A cutout recess 71 similar to that of the lower grip 7L is formed on the lower surface of the upper platen, and the upper platen 22 is installed via the upper platen mount 21. The boss 21a protruding from the upper surface of the mounting base 21 is fitted into the notch recess 71 to center the mounting base 21 with respect to the load shaft. The mount 21 is fixed to the upper grip 7U with bolts 23. A fitting hole 21b is formed on the lower surface of the mounting base 21, and the upper platen 22 is formed in the fitting hole 21b.
The boss 22a is fitted, the upper platen 22 is centered with respect to the load shaft, and then fixed to the mounting base 21 with the bolt 25.

Therefore, when the compression test is performed after the tensile test is completed, it is not necessary to remove the upper and lower grips as in the conventional case. When the test piece is placed and the return cylinder 8 is extended, the test piece is compressed. Therefore, workability is improved.

In the above-described embodiment, the gripping tool for opening and closing the gripping teeth by the hydraulic cylinder has been described. However, a screw-type gripping tool or a screw-type gripping tooth member is rotated by a hydraulic motor or an electric motor to operate the gripping tooth member. The present invention can be applied to a gripping tool that opens and closes. Also,
Although the case where the test piece is loaded by the backward movement cylinder 8 has been described, the present invention can be applied to a material testing machine that loads the test piece between the crosshead that moves up and down by a screw rod and the table, and any load mechanism can be used. Absent. Further, a bending test can be performed by installing a bending jig in the upper and lower grips instead of the platen device. Therefore, the present invention can be applied to a material testing machine in which a jig for compression test and a jig for bending test can be installed in the grip for tensile test, and a material test in which various jigs are installed in the grip to perform various tests. Applicable to machine. It can also be applied to horizontal material testing machines.

In the correspondence between the above embodiment and the claims, the upper and lower grips 7U and 7L are the first and second grips, the upper and lower platens 20 and 30 are the test piece mounting jigs, and the notch recesses. Reference numeral 71 constitutes a mounting portion, and ram cylinder 8 constitutes a load mechanism.

[0020]

As described in detail above, in the material testing machine according to the present invention, during the tensile test, the first and second grips grip the test piece and both grips are driven separately to form a test piece. In addition to applying a tensile load, when performing a compression test or bending test that is different from the tensile test, install a test piece mounting jig such as a platen on the jig mounting part of the first and second grips and place the test piece between the jigs. Since the compression is performed, other tests such as a tensile test and a compression test can be performed in the same working space, and the workability is improved because it is not necessary to remove the upper and lower grips for the tensile test.

[Brief description of drawings]

FIG. 1 is a front view showing a case where a tensile test is performed in an embodiment of a material testing machine according to the present invention.

FIG. 2 is a front sectional view showing an embodiment of a fluid open / close type grip installed in the material testing machine of FIG.

FIG. 3 is a front view showing a case where a compression test is performed by an embodiment of the material testing machine according to the present invention

FIG. 4 is an enlarged view around the upper and lower platen device of FIG.

FIG. 5 is a large plan view of the lower platen device of FIG.

FIG. 6 is a plan view of the lower grip.

FIG. 7 is an enlarged view showing the boss periphery of the platen mount.

FIG. 8 is a front view showing an example of a conventional material testing machine.

FIG. 9 is a front view showing an example of a conventional material testing machine.

[Explanation of symbols]

 1 Base 2, 3 Struts 4 Crosshead Hydraulic Clamp 5 Crosshead 6 Crosshead Elevating Cylinder Device 7U Upper Grip 7L Lower Grip 7a Grip Main Body 7b Piston 7c Cylinder 7d Holder 7e Grip 8 Reciprocating Cylinder 9 Piston Rod 20 Upper Platen Device 21 Upper Platen Mounting Base 21a Boss 22 Upper Platen 30 Lower Platen Device 31 Lower Platen Mount 31a Boss 32 Lower Platen

Claims (1)

[Claims] 1. A first gripping tool that includes a pair of gripping teeth that are held in contact with each other to grip a test piece, and that includes a mounting portion of a test piece mounting jig such as a platen, and the first gripping tool. A second grip provided with a pair of gripping teeth that are provided facing each other to hold the test piece in contact with each other, and a second grip having a mounting portion of a test piece mounting jig such as a platen; While holding the test piece by the first and second grips and driving both grips away from each other to apply a tensile load to the test piece, at the time of a test such as a compression test different from the tensile test, the first and second grips are used. And a loading mechanism for applying a compressive load to the test piece by a test piece mounting jig such as a platen attached to the mounting portion of each gripping tool. .