JPH11160212A - Real-size material testing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a real-size material testing machine with a highly safe clamp mechanism in a simple structure. SOLUTION: A piston 22 is placed in a cylinder case 20. A bolt 20 is helically attached to the piston 22 with such an axial force as to displace a caned disc spring 27 by a predetermined amount. By the axial force of the bolt 29, a crosshead 10 clamps a column 2. When oil pressure is supplied into space 30 in a cylinder 22, the piston 22 is moved against the reactive force of the coned disc spring 27, and the head part 29a of the bolt 29 is moved in a direction distancing from the bearing surface of a counterbored part 13. By this, the axial force of the bolt 29 becomes 0, and the crosshead 10 releases the column 2. As a force by which the crosshead 10 clamps the column 2 is generated only by the elastic force of a metal material without using any hydraulic force, and oil pressure is used only at the time of unclamping, there is no danger that the bonding between the crosshead 10 and the column 2 is released due to a deficiency in a hydraulic circuit during test.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a full-scale specimen for applying a load such as compression, tension or bending to a full-sized specimen such as a wooden pillar and measuring the strength or rigidity of the specimen. It relates to a material testing machine.

[0002]

2. Description of the Related Art A full-scale material testing machine is different from a testing machine which handles a small specimen such as a cut-out test piece, and performs a physical strength test of a full-sized specimen, for example, a pillar of wood used for a building material. Device. FIG. 3 shows a conventional full-scale material testing machine. As shown in FIG. 3, the conventional full-scale material testing machine includes a testing machine base 101 buried on the floor, a pair of columns 102, 102 erected on the testing machine base 101,
And a crosshead 103 that slides on the column 102. The crosshead 103 has a lifting hydraulic cylinder 10
4 and the crosshead 103 is attached to the support 102
Is provided with a hydraulic clamping device 107 for clamping to the workpiece. Adjustment of the position of the cross head 103 in the vertical direction is performed by moving the tube portion 105 of the lifting hydraulic cylinder 104 forward and backward with the clamp device 107 released. When the crosshead 103 comes to a desired position, the column 102 is tightened by the hydraulic clamping device 107 to fix the crosshead 103. Thereafter, a load is applied to the specimen S by the pressure plate 109 by operating the backward-acting hydraulic cylinder 108 attached to the crosshead 103. A spring-return type center hole cylinder is often used as a hydraulic clamping device 107 for clamping the crosshead 103 to the column 102. That is,
The conventional hydraulic clamping device 107 generates a clamping force according to the hydraulic pressure when a hydraulic pressure is applied from an external hydraulic source.

[0003]

However, the conventional full-scale material testing machine described above has the following problems. That is, since the fixing of the crosshead 103 depends on the hydraulic circuit attached to the hydraulic clamp device 107,
If a failure occurs in the hydraulic circuit during the test, the fixation of the crosshead 103 is released, and the specimen may fall. As described above, the specimens handled by the full-scale material testing machine are very large and heavy. May be at risk. To prevent this from happening,
Hydraulic circuits require very high reliability, which complicates the hydraulic circuit and requires frequent maintenance of the hydraulic circuit, which is extremely costly and time-consuming. Has occurred.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a highly safe clamping mechanism without complicating the structure, thereby providing an inexpensive and highly safe full-scale material testing machine. With the goal.

[0005]

In order to achieve the above object, the present invention relates to a full-scale material testing machine for testing a full-size specimen such as a wooden pillar or the like, comprising: a testing machine base; A pillar that is vertically arranged from above, a crosshead that is provided to be able to move up and down along the pillar, a spring member, a spring-type clamping device that clamps the crosshead to the pillar, and the crosshead. An elevating device for raising and lowering, and a specimen loading device provided on the crosshead for applying a load to the specimen, wherein the spring member is incorporated in the spring-type clamp device in a state of being displaced by a predetermined amount, and The present invention provides a full-scale material testing machine characterized in that the clamping device clamps the crosshead to the support with a clamping force corresponding to a reaction force generated by the spring member.

[0006] Preferably, the spring-type clamping device comprises:
The apparatus further includes means for displacing the spring member, and by changing the displacement amount of the spring member from the state displaced by the predetermined amount, it is possible to release the clamping force of the spring clamp device.

[0007] More preferably, the means for displacing the spring member operates by hydraulic pressure.

The present invention also relates to a full-scale material testing machine for testing a full-sized specimen such as a pillar of wood or the like, comprising: a testing machine base; a column vertically erected from the testing machine base; A crosshead provided so as to be able to ascend and descend along a column, having a hole through which the column is inserted, and a slit extending from the hole to the outside of the crosshead, and a first position located across the slit. Part and second
And a first or second supported spring member of the crosshead, and the first and second portions of the crosshead are interposed via the spring member. A tightening member for tightening so as to narrow the width of the slit, an elevating device for elevating the crosshead, and a specimen loading device provided on the crosshead and applying a load to the specimen are provided. Provide a full-scale material testing machine.

Preferably, the full-size material testing machine further comprises means for moving the tightening member against a reaction force of the spring member, and the tightening force of the tightening member is reduced by displacing the tightening member. It is configured to be released.

[0010] More preferably, the means for moving the tightening member is operated by hydraulic pressure.

Further, the present invention relates to a full-scale material testing machine for testing a full-size specimen such as a wooden pillar, comprising: a testing machine base; a column standing upright from the testing machine base; A cross head provided so as to be able to ascend and descend along a first portion, wherein the first portion has a hole through which the support is inserted, and a slit extending from the hole to the outside of the cross head, and is located across the slit. And a crosshead having a second portion, a cylinder case attached to the first portion of the crosshead, a piston disposed in the cylinder case, one side of which is supported by the piston, A spring member whose other side is supported by the first portion of the crosshead, one side of which is fixed to the piston, and whose other side is the first side of the crosshead. Wherein the first member and the second portion of the crosshead have a tightening force corresponding to a reaction force generated by the spring member while deforming the spring member by a predetermined amount. A tightening member for tightening to reduce the width of the slit, a hydraulic pressure source for supplying hydraulic pressure into the cylinder case, and displacing the piston against a reaction force of the spring member,
Provided is a full-scale material testing machine, comprising: an elevating device for elevating and lowering the crosshead; and a specimen loading device provided on the crosshead and applying a load to the specimen.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are views showing one embodiment of the present invention.

First, the overall configuration of a full-scale material testing machine will be described with reference to FIG. As shown in FIG. 1, the full-scale material testing machine includes a testing machine base 1 embedded in a floor F, a pair of columns 2, 2 erected vertically from the testing machine base 1, and Crosshead 10 provided to be able to move up and down
A lifting device 40 for vertically moving the crosshead 10 up and down, a specimen loading device 50 attached to the crosshead, and a specimen support device 60. The crosshead 10 has a spring-type clamping device (detailed configuration will be described later) for clamping the crosshead 10 to the column 2.

A rail R is laid on the floor F and on the upper surface 1a of the tester base 1 located at the same height as the floor F. The rail R is preferably embedded in the floor F and the tester base 1. The rail R passes between the columns 2 and 2 and crosses a line connecting the pair of columns 2 and 2 at a predetermined angle. This intersection angle is preferably 45 degrees. The specimen support device 60 includes a carriage 61 movable on the rail R, and a specimen support section 62 mounted on the carriage 61.

One lifting device 40 is provided on each of the columns 2, and one of them is provided with one of the crossheads 10.
On the front surface 10c side, and the other
It is provided on the b side. The elevating device 40 is composed of a hydraulic cylinder 41 having a rod portion 42 that can move forward and backward in the vertical direction, and a grip portion 45 attached to the tip of the rod portion 42 and gripping the column 2. The grip part 45 has a built-in grip mechanism (not shown). The tube part 43 of the hydraulic cylinder 41 is fixed to the crosshead 10. The lifting / lowering device 40 cooperates with a spring-type clamping device provided on the crosshead 10 to (1) hold the grip 45 of the lifting / lowering device 40.
(2) Unclamping of a spring-type clamping device (details of the operation will be described later), (3) Advance / retreat operation of the tube section 43, (4) Clamping of a spring-type clamping device, (5) Lifting device By sequentially repeating the unclamping of the gripping portion 45 of (40) and the (6) advance / retreat operation of the tube portion 43, a function of freely moving the crosshead 10 up and down along the column is realized.

The specimen load device 50 schematically shown in FIG. 1 has a hydraulic cylinder, preferably a return-type hydraulic cylinder 51, which is firmly attached to the crosshead 10. Rod of hydraulic cylinder 51 (not shown)
, A load cell 55 and a specimen support 53 are attached via an attachment jig 52. Hydraulic cylinder 51
The force applied to the specimen S is monitored by the load cell 55 provided between the mounting jig 52 and the specimen support 53.

Next, referring to FIG. 2, the details of the structure of the crosshead 10 and a spring-type clamping device for clamping the crosshead 10 to the column 2 will be described. The crosshead 10 has holes 11, 11 at both ends in the longitudinal direction, through which the columns 2, 2 are inserted. The mounting structure of the crosshead 10 to the column 2 and the configuration of the clamp mechanism are the same at both ends of the crosshead 10 (however, the front-back relationship is different on both sides; see FIG. 1).
Therefore, only one configuration will be described below.

The crosshead 10 has a slit 12 extending from a hole 11 for inserting the support column 2 toward the outside of the crosshead 10, that is, toward the side surface 10a. The slit 12 vertically traverses the crosshead. Further, the slit 12 traverses the slit 12 from the rear surface 10 b to the front surface 10 c of the crosshead 10.
A through-hole 13 extending in a direction perpendicular to the vertical direction (the vertical direction in FIG. 2) is formed. On the front face 10c of the crosshead 10,
A recess 14 is formed.

A cylinder case 20 having a substantially rectangular parallelepiped shape is fitted into the recess 14 of the crosshead 10, and the cylinder case 20 is fixed to the crosshead 10 by bolts 21 arranged at four corners thereof. . The recess 14 and the two cylinder cases 20 mounted in the recess 14 are respectively provided at both ends of the crosshead 10, but in the following description,
Only one of them will be described.

The cylinder case 20 has a cylindrical internal space 30 therein, and a steel piston 22 is arranged in the internal space 30 so as to be able to reciprocate. The piston 22 has a large cylindrical portion 23 and a small cylindrical portion 24 formed coaxially and integrally with each other. At the center of the small cylindrical portion 24 of the piston 22, a screw hole 25 in which a female screw is formed is provided. A groove is formed on the outer peripheral surface of the large cylindrical portion 23 over the entire periphery thereof, and an oil seal 26 is mounted in the groove. The oil seal 26 separates the internal space 30 into two spaces 30a and 30b which are isolated from each other in a liquid-tight manner.

A plurality of annular disc springs 27 are fitted in the small cylindrical portion 24 located on the space 30a side. The plurality of disc springs 27 are composed of a first disc spring group 27A including the same number (three in this example) of disc springs 27 and a second disc spring group 27A.
Of the disc spring group 27B. Each disc spring group 27A, 27
The B-shaped disc springs are stacked in the same direction. The disc springs of the both disc spring groups 27A and 27B face in opposite directions, and the disc springs 27 constituting the disc spring group 27A.
Of the disc spring group 27B side, the disc spring group 27B
Among the disc springs 27 constituting B, the disc springs closest to the disc spring group 27A side are in contact with the respective inner peripheral sides. By dividing a plurality of disc springs into a plurality of disc spring groups, the disc spring 2
The operation of 7 becomes smooth.

A spring member is constituted by the plurality of disc springs 27 described above. The spring member may be constituted by a single disc spring or may be constituted by a coil spring.
It is preferable to adopt a laminated structure including a plurality of disc springs 27 as shown in FIG.

When the disc spring 27 is displaced, in order to prevent the disc spring 27 made of hard spring steel from being damaged, the outer peripheral surface of the small cylindrical portion 24 and the top surface of the large cylindrical portion 23 (opposed to the disc spring 27). (A radial plane) is quenched. When the disc spring 27 is displaced, the crosshead 10 made of relatively soft steel is prevented from being damaged by the outer peripheral edge of the disc spring 27 at the end of the first disc spring group 27A. An annular disk 28 is provided on the bottom surface 14 a of the recess 14 of the crosshead 10. As described above, one side of the spring member including the plurality of disc springs 27 is directly supported by the piston 22, and the other side is indirectly supported by the crosshead 10 via the disk 28. .

When the disc spring 27 is displaced, the diameter of the inner peripheral surface of the cylinder case 20 is opposed to the diameter of the disc spring 27 so that the outer peripheral surface of the disc spring 27 does not contact the inner peripheral surface of the cylinder case 20. Is larger than the other parts.

The through hole 13 has a hexagon socket head bolt 2
9 (fastening member) is inserted, and this bolt 29
Is a screw hole 2 of the small cylindrical portion 24 on one side, that is, a male screw portion.
5 screwed. The bolt 29 is tightened so as to displace each disc spring 27 by a predetermined amount. Accordingly, the bolt 29 tightens the crosshead portions 15 and 16 located on both sides of the slit 12 so as to reduce the width of the slit 12 with an axial force corresponding to the reaction force of the disc spring 27. As a result, the crosshead 10 is
The column 2 inserted into the column 1 is tightened, and the crosshead 10 is fixed to the column 2 so as not to move in the vertical direction. In this state, a space d1 is formed between the top surface of the small cylindrical portion 24 of the piston 22 (a radial plane facing the disk 28) and the annular disk 27 for protecting the crosshead 10.

The cylinder case 20 is provided with an oil supply hole 31 communicating with a space 30b formed between the bottom surface 20a of the cylinder case 20 and the bottom surface 23a of the large cylindrical portion 23 of the piston 22. The supply hole 31 communicates with a hydraulic source (not shown) via a plug and a pipe.

The through hole 13 has a counterbore 13 a provided on the entrance side of the through hole 13. The other side of the bolt 29, that is, the head 29a is accommodated in the counterbore 13a. The head 29a of the bolt 29 is supported by the portion 15 of the crosshead 10 by sitting on the seat surface 13b of the counterbore 13a.

A lid 32 is attached to the counterbore 13a. The lid 32 has a flange 33 having a cylindrical shape. The outer peripheral surface of the flange 33 abuts against the inner peripheral surface of the counterbore portion 13a having a columnar shape, whereby the lid 30 is moved to the counterbore portion 13a
Is positioned and fixed. The lid 32 is a counterbore 13a.
It is attached to the crosshead 10 by a plurality of bolts 36 arranged on all sides of the head. Also, the lid 32
Is a column 3 having a hexagonal cross section extending from the base portion 34 toward a hexagon hole 29b formed in the head portion 29a of the bolt 29.
Five. The pillar 35 is housed in the hexagonal hole 29b,
The bolt 29 is restrained so that the bolt 29 cannot freely rotate around the axis, and the bolt 29 is allowed to move only in the axial direction. The pillar 35 guides the bolt 29 in the axial direction, and also serves to prevent the assembly of the bolt 29 and the piston 22 from falling down in the axial direction.

A spring member constituted by the cylinder case 20, the piston 22, and the plurality of disc springs 27 described above,
The bolt 29 constitutes a spring-type clamping device.

Next, the operation of the present embodiment having the above configuration will be described with reference to FIGS. In the following description, a case where a columnar wood is used as the specimen S and a compression strength test is performed will be described.

First, the specimen support device 60 is disposed directly below the specimen load device 50. Next, the specimen support device 60
Is fixed to the tester base 1 or the floor F by means such as bolts (not shown). Next, the specimen S is placed on the specimen support portion 62 of the specimen support apparatus 60 by a transfer device such as a crane (not shown). The specimen S is firmly fixed to the specimen support 62 by bolts 63 provided on all sides of the specimen support 62.

Next, the height of the crosshead 10 is adjusted according to the size of the specimen S. As described above, this adjustment is performed by (1) clamping the support column 2 by the grip portion 45 of the lifting / lowering device 40, (2) unclamping the spring-type clamping device (the details of the operation will be described later), and (3) the tube portion 43. (4) Clamping of spring-type clamping device, (5)
It is performed by sequentially repeating the unclamping of the gripping portion 45 of the lifting device 40 and the (6) advance / retreat operation of the tube portion 43. Hereinafter, the clamping and unclamping operations of the spring clamp device will be described.

As described above with reference to FIG. 2, the crosshead 10 clamps the column 2 with a force corresponding to the axial force of the bolt 29 forming a part of the spring-type clamping device.
In this state, a hydraulic pressure is supplied to the space 30 b in the cylinder case 20 via the oil supply hole 31 by a hydraulic pressure source (not shown). When the hydraulic pressure overcomes the spring force of the disc spring 27, the piston 22 moves upward in FIG. Then, the bolt 29 moves upward in FIG. 2, and the axial force of the bolt 29 is greatly reduced. Thus, due to the elasticity of the crosshead 10 itself, the portions 15, 16 of the crosshead 10 located across the slit 12 move in a direction away from each other. As a result, the crosshead 10 releases the strut 2,
It is possible to freely move up and down.

In this state, as described above, the lifting device 40
, The crosshead 10 can be moved to a desired position. Then, when the oil pressure in the space 30 in the cylinder case 20 is reduced to a predetermined value or less (for example, to 0), the bolt 29 is pulled back toward the cylinder case 20 by the reaction force of the disc spring 27, and the crosshead 10 So that the parts 15, 16 of
That is, the portions 15, 1, 1
6 will be loaded. Thereby, the crosshead 1
0 means that the column 2 is firmly clamped again.

Next, the test piece S is fixed by bolts 54 provided on all sides of the test piece support portion 53 of the test piece loading device 50.
Is firmly fixed to the testing machine.

In this state, the compression test is performed by operating the specimen load device 50.

As described above, according to the present embodiment, the force by which the crosshead 10 clamps the column 2 is generated by the spring force of the disc spring 29 and does not depend at all on the hydraulic device. Can be enhanced.

In the above description, the case where the compression test is performed has been described. However, according to the present testing machine, a three-point bending test or a four-point bending test or a tensile test can be performed. In this case, the number of the specimen supporting devices 60 may be increased, or the specimen loading unit 5 of the specimen loading apparatus 50 may be used.
It will be easily understood by those skilled in the art that the configuration can be easily coped with by changing the configuration of the specimen support part 62 of the specimen support apparatus 60 and the specimen support apparatus 60. In particular, when a bending test is performed, two specimen support devices 60 are used (in this case, the structure of the specimen support portion 62 is also changed).
, The span of the support point that supports the specimen S from below can be easily adjusted.

Furthermore, in the above embodiment, hydraulic means is used as means for moving (displacing) the piston 22 (ie, means for displacing the spring member or means for moving the tightening member), and this is the most preferable. However, the present invention is not limited to this. Piston 22
May be displaced by a fluid pressure other than oil, or may be displaced by mechanical means such as a linear motion mechanism (linear drive device).

[0040]

As described above, according to the present invention,
A highly safe clamping mechanism can be obtained without complicating the structure, and a highly safe full-scale material testing machine can be obtained.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a full-size material testing machine according to the present invention, and is a perspective view showing an entire configuration of the full-size material testing machine.

FIG. 2 is a partial cross-sectional view showing a configuration of a crosshead clamping mechanism (spring-type clamping device).

FIG. 3 is a front view showing a conventional full-size material testing machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Testing machine base 2 Prop 10 Crosshead 11 (Crosshead) hole 12 (Crosshead) slit 15, 16 First and second part (Crosshead) 22 Piston 27 Spring member (disc spring) 29 Fastening member (Bolt) 40 Lifting device 50 Specimen loading device

Claims (7)

[Claims] 1. A full-scale material testing machine for testing a full-size specimen such as a wood pillar, comprising: a testing machine base; a column vertically erected from the testing machine base; A cross head provided so as to be able to move up and down, a spring-type clamping device having a spring member, and clamping the cross head to the support; an elevating device for moving the cross head up and down; A specimen loading device for applying a load to the specimen, wherein the spring member is incorporated in the spring-type clamp device in a state of being displaced by a predetermined amount, and the spring-type clamp device responds to a reaction force generated by the spring member. A full-scale material testing machine, wherein the crosshead is clamped to the column with a clamping force. 2. The spring-type clamping device further comprises means for displacing the spring member, wherein the displacement amount of the spring member is changed from the state of being displaced by the predetermined amount to thereby clamp the spring-type clamping device. The full-scale material testing machine according to claim 1, wherein the force can be released. 3. The full-scale material testing machine according to claim 2, wherein the means for displacing the spring member operates by hydraulic pressure. 4. A full-scale material testing machine for testing a full-size specimen such as a wooden pillar, comprising: a testing machine base; a column vertically erected from the testing machine base; A crosshead provided so as to be able to move up and down, having a hole through which the column is inserted, and a slit extending from the hole to the outside of the crosshead,
A crosshead having a first portion and a second portion positioned with the slit interposed therebetween; a spring member supported by the first or second portion of the crosshead; and A tightening member for tightening the first portion and the second portion of the crosshead so as to reduce the width of the slit; an elevating device for elevating the crosshead; a load provided on the crosshead; A full-scale material testing machine, comprising: 5. The apparatus according to claim 1, further comprising: means for moving said tightening member against a reaction force of said spring member, wherein said tightening member is moved to release the tightening force of said tightening member. The full-scale material testing machine according to claim 4, wherein 6. The full-scale material testing machine according to claim 5, wherein the means for moving the fastening member is operated by hydraulic pressure. 7. A full-scale material testing machine for testing a full-size specimen such as a wooden pillar, comprising: a testing machine base; a column vertically erected from the testing machine base; A crosshead provided so as to be able to move up and down, having a hole through which the column is inserted, and a slit extending from the hole to the outside of the crosshead,
A crosshead having a first portion and a second portion located across the slit; a cylinder case attached to the first portion of the crosshead; a piston disposed in the cylinder case; A spring member having one side supported by the piston and the other side supported by a first portion of the crosshead; a spring member having one side fixed to the piston and the other side being a second portion of the crosshead; A first member and the second portion of the crosshead having a tightening force corresponding to a reaction force generated by the spring member while deforming the spring member by a predetermined amount. A tightening member for tightening so as to narrow the width of the slit, and supplying a hydraulic pressure into the cylinder case to resist a reaction force of the spring member. A hydraulic source for displacing the piston, an elevating device for elevating and lowering the crosshead, and a specimen loading device provided on the crosshead and applying a load to the specimen. Material testing machine.