JP2022116332A - Compression test jig, material test machine, and parallelism adjustment method in material test machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily adjust parallelism between a pressed surface of a specimen and a compression surface of a platen.

SOLUTION: A compression test jig for use in a material test machine includes: a platen having at least a spherical surface section and a platen section; a holding unit for storing the spherical section to rotatably and swingably hold the platen relative to a load shaft of the material test machine; and a fixing section for fixing the platen to the holding unit.

SELECTED DRAWING: Figure 4

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a compression test jig, a material testing machine, and a parallelism adjusting method in the material testing machine.

2. Description of the Related Art In a material testing machine that performs a compression test, there is known one that uses a so-called spherical seat type platen as a platen for applying a compressive load to a specimen (see, for example, Patent Document 1). The spherical seat type platen can adjust the degree of parallelism between the compression surface of the platen and the surface to be compressed of the specimen by sliding in spherical contact with the spherical seat.

JP-A-6-331518

Although it is possible to adjust the degree of parallelism between the compressed surface of the test piece and the compression surface of the platen by using the spherical seat type platen as described above, depending on the material of the test piece, if a large load is applied, damage may occur. Therefore, there is a demand for a device that can easily adjust the degree of parallelism by bringing the platen into contact with a low load.

A compression test jig used in a material testing machine according to a first aspect of the present invention includes a platen having at least a spherical portion and a platen portion, a platen containing the spherical portion, and rotating about a load axis of the material testing machine. A holding portion that holds the platen so as to be capable of swinging, and a fixing portion that fixes the platen to the holding portion.
According to a second aspect of the invention, a materials testing machine has a compression test fixture according to the first aspect.
According to a third aspect of the present invention, the method for adjusting parallelism in a material testing machine according to the second aspect comprises moving the platen for a predetermined test while being rotatable and swingable with respect to the load axis of the material testing machine. a contact step of contacting the end surface of the test piece with force; an adjustment step of rotating and/or swinging the platen to adjust the parallelism between the end surface of the test piece and the compression surface of the platen portion of the platen; a determination step of determining whether or not the predetermined test force has decreased after the adjusting step; and if it is determined that the predetermined test force has decreased in the determination step, the predetermined test force has decreased. and an iterative step of repeating said contacting step and said adjusting step until it is exhausted.

According to the present invention, it is possible to easily adjust the parallelism between the surface to be compressed of the specimen and the compression surface of the platen.

FIG. 1 is a schematic diagram of a material testing machine according to one embodiment of the present invention. FIG. 2 is a diagram showing a basket-shaped jig used in the material testing machine of FIG. FIG. 3 is a diagram for explaining the relationship between the specimen and the compression test jig. 4(a) and 4(b) are a plan view and a cross-sectional view showing a cage-shaped compression test jig. FIG. 5 is a flowchart for explaining a parallelism adjusting method according to one embodiment.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a material testing machine according to one embodiment of the present invention. As shown in FIG. 1, the material testing machine 1 of the present embodiment comprises a base 11, a pair of right and left screw necks 12 erected on the base 11, and a A yoke 13 and a crosshead 15 are provided. The crosshead 15 has a nut portion that is screwed with the pair of left and right threaded rods 12 and moves up and down with respect to the threaded rods 12 . A basket-shaped jig 30 is arranged between the base 11 and the crosshead 15 . The basket-shaped jig 30 is attached to the crosshead 15 via the load cell 16, and has a compression test jig for a compression test, which will be described later.

Below the base 11 are a motor 20 for compression and tension loads, a synchronous pulley 21 rotated by the drive of the motor 20, a synchronous pulley 22 disposed at the lower ends of a pair of screw rods 12, and a synchronous pulley 22. A belt 23 is arranged. Synchronous pulley 21 and synchronous pulley 22 are each engaged with synchronous belt 23 . The synchronous pulleys 21 and 22 are rotated by driving the motor 23, and the pair of screw rods 12 are rotated in synchronization therewith. The crosshead 15 moves up and down in the axial direction of the screw rods 12 by rotating the pair of screw rods 12 . Movement of the crosshead 15 applies a test force to the specimen placed in the cage jig 30 .

FIG. 2 shows a basket-shaped jig 30 attached to the material testing machine 1. As shown in FIG. As shown in FIG. 2, the cage jig 30 includes a guide bush 31, an upper support plate 32 and a lower support plate 33 fixed to the guide bush 31, and an upper movable plate movable with respect to the guide bush 31. 34 and a lower movable plate 35 . The upper movable plate 34 and the lower movable plate 35 are attached to the guide bush 31 via linear bushes 34a and 35a, respectively, and are configured to be vertically movable along the guide bush 31 . A compression test jig 40 is attached to the upper movable plate 34 , and a mount 36 for holding the specimen TP is fixed to the lower movable plate 35 .

An upper shaft 37 of the cage jig 30 is connected to the crosshead 15 via the load cell 16 and a lower shaft 38 is connected to the base 11 . When the crosshead 15 moves upward, the upper support plate 32 moves upward together with the upper shaft 37, and accordingly the upper movable plate 34 and the lower movable plate 35 move toward each other along the guide bush 31. . As a result, the specimen TP held on the mount 36 is compressed by the compression test jig 40 .

Here, let us consider a case where a compression test is performed using a specimen TP made of a rectangular flat plate as shown in FIG. If the surface to be compressed of the test piece TP and the compression surface of the compression test jig 40 are not parallel due to the effects of manufacturing dimensional errors of the test piece TP, assembly errors of the compression test jig 40, etc., If the compression test jig 40 comes into contact with one side, it becomes impossible to accurately apply a compression load in a direction perpendicular to the compressed surface of the specimen TP.

In recent years, the use of carbon fiber reinforced plastics (thermoplastic CFRP) using thermoplastic resins with excellent workability and moldability has been studied as a structural material for automobiles and the like, which requires strength and durability. Thermoplastic CFRP is a composite material and has anisotropy, and depending on the principal axis direction of applied stress, it exhibits complex fracture behavior such as tension, compression, bending, in-plane shear, out-of-plane shear, or a combination thereof. show. When conducting a material test on such a material, it is necessary to apply a test force with high accuracy in a direction perpendicular to the compressed surface of the specimen TP to perform an accurate evaluation.

In one embodiment of the present invention, the angle (posture) of the compression test jig 40 can be adjusted in order to adjust the parallelism between the compressed surface of the specimen TP and the compression surface of the compression test jig 40. Configure.
4(a) and 4(b) show a plan view and a sectional view showing a compression test jig 40 of the basket-shaped jig 30. FIG. The compression test jig 40 is fixed to the upper movable plate 34 of the cage jig 30 with a plurality of fixing bolts 39 . As shown in FIG. 4B, the compression test jig 40 according to the present embodiment is swingable with respect to the load axis (load axis) L of the material testing machine 1 and rotatable around the load axis. It has a configured angle adjustment platen 41 . By adjusting the angle (posture) of the angle adjustment platen 41 with respect to the load axis L, the parallelism of the compression surface of the angle adjustment platen 41 with respect to the end face, which is the surface to be compressed, of the specimen TP is adjusted.

The angle adjusting platen 41 is composed of a platen portion 42 , a rod portion 43 and a spherical surface portion 44 . A spherical portion 44 of the angle adjustment platen 41 is accommodated in a casing 46 via a spherical joint 45 . The casing 46 is a substantially cylindrical member, and is designed to have the smallest inner diameter at the lower end in FIG. 4(b). As a result, the angle adjustment platen 41 is configured not to fall off from the casing 46 . The casing 46 functions as a holding portion that holds the angle adjustment platen 41 , and the angle adjustment platen 41 is held by the casing 46 so as to be swingable and rotatable with respect to the load axis L of the material testing machine 1 .

Above the casing 46, a fixed portion composed of a first wedge member 51, a second wedge member 52, and a screw member 53, and a base portion 48 are provided. The first wedge member 51 has an inclined surface on the angle adjusting platen 41 side, and the second wedge member 52 has an inclined surface on the side opposite to the inclined surface of the first wedge member 51 . The threaded member 53 is screwed into a threaded hole formed in the second wedge member 52 , and by rotating the threaded member 53 , the second wedge member 52 moves relative to the first wedge member 51 .

The fixed portion, base portion 48 and casing 46 are connected to each other by a plurality of bolts 49 . When the screw member 53 is rotated to move the second wedge member 52 to the left in FIG. The pressed base portion 48 presses the spherical portion 44 against the casing 46 via the spherical seat 47 , thereby restricting the rotation and swinging of the angle adjustment platen 41 . Thereby, the position of the angle adjusting platen 41 with respect to the casing 46 is fixed, and the angle (position) with respect to the load axis L of the material testing machine 1 is fixed.

When the screw member 53 is rotated to move the second wedge member 52 to the right in FIG. As a result, the angle adjustment platen 41 can rotate and swing with respect to the load axis L. As shown in FIG.

Next, a parallelism adjusting method of the material testing machine 1 using the angle adjusting platen 41 according to the embodiment of the present invention will be described. FIG. 5 is a flowchart for explaining a parallelism adjusting method according to one embodiment. The parallelism adjusting method shown in FIG. It is held in a rotatable state. A specimen TP is held by a mounting base 36 .

First, in step S10, the motor 20 of the material testing machine 1 is driven, the crosshead 15 is moved, and the platen portion 42 of the angle adjusting platen 41 is brought into contact with the end face of the specimen TP. The test force when the platen portion 42 of the angle adjusting platen 41 is brought into contact with the end surface of the test piece TP is small enough so that it can be determined that the angle adjusting platen 41 has contacted the end surface of the test piece TP and the test piece TP is not damaged. An appropriate value is set in advance as a suitable compressive load.

In step S20, the angle adjustment platen 41 is oscillated and/or rotated with respect to the load axis L of the material testing machine 1 to adjust the angle, and the unevenness between the angle adjustment platen 41 and the end surface of the test piece TP is corrected. to remove When the angle adjustment platen 41 and the end surface of the test piece TP are non-uniform, the angle adjustment platen 41 is in uneven contact with the end surface of the test piece TP, and the compression surface of the platen portion 42 of the angle adjustment platen 41 is uneven. This is a state in which the end face of the specimen TP is not parallel. Therefore, by rocking or rotating the angle adjustment platen 41, the uneven contact between the compression surface of the platen portion 42 of the angle adjustment platen 41 and the end face of the test piece TP is eliminated so that they are parallel to each other. adjust to

In step S30, it is determined whether or not the test force applied to the specimen TP has decreased by adjusting the posture of the angle adjustment platen 41 in step S20. When the test force decreases, it is determined that the uneven contact between the angle adjustment platen 41 and the end face of the test piece TP is eliminated and the load applied to the test piece TP is removed. In this case, the process returns to step S10, and the processes of steps S10 and S20 are repeated. In step S10, the angle adjustment platen 41 is brought into contact with the end face of the specimen TP again with the same test force as the previous time.

On the other hand, when the test force does not decrease, the desired parallelism is achieved between the compression surface of the platen portion 42 of the angle adjustment platen 41 and the end surface of the test piece TP by adjusting the attitude of the angle adjustment platen 41. Then, the process proceeds to step S40. In step S40, the screw member 53 of the fixed portion is rotated to press the second wedge member 52 against the base portion 48, thereby fixing the position of the angle adjustment platen 41 with respect to the casing 46. FIG. As a result, the parallelism adjustment work is completed, and the process shown in the flowchart of FIG. 5 is completed. A compression test is performed by the material testing machine 1 in a state in which the parallelism is adjusted in this way.

According to the embodiment described above, the following effects are obtained.
(1) The compression test jig 40 accommodates the angle adjusting platen 41 having at least the spherical portion 44 and the platen portion 42, and the spherical portion 44, and is rotatable and swingable with respect to the load axis L of the material testing machine 1. A casing 46 for holding the angle adjustment platen 41 and a fixing portion for fixing the angle adjustment platen 41 to the casing 46 are provided. As a result, the angle adjusting platen 41 can be fixed in an adjusted state, so that a compressive load can be accurately applied to the surface of the specimen TP to be compressed.

(2) The fixing portion includes a first wedge member 51 having an inclined surface, a second wedge member 52 having an inclined surface facing the first inclined surface of the first wedge member 51, and a and a screw member 53 for moving the second wedge member 52 . The angle adjustment platen 41 is fixed to the casing 26 by pressing the second wedge member 52 toward the casing 46 using the first wedge member 51 and the threaded portion 53 . Thus, by using the wedge mechanism, it becomes possible to easily adjust the parallelism between the surface to be compressed of the specimen TP and the compression surface of the platen portion 42 of the angle adjusting platen 41 .

(3) When adjusting the parallelism in the material testing machine 1, the angle adjustment platen 41 is applied with a predetermined test force in a rotatable and swingable state with respect to the load axis L of the material testing machine 1. and an adjustment of rotating and/or swinging the angle adjustment platen 41 to adjust the parallelism between the end surface of the test piece TP and the compression surface of the platen portion 42 of the angle adjustment platen 41. After the step (S20) and the adjustment step, a determination step (S30) for determining whether or not the predetermined test force has decreased; an iterative step of repeating the contacting step and the adjusting step until the force no longer drops. This makes it possible to easily adjust the degree of parallelism between the surface to be compressed of the specimen TP and the angle adjustment platen 41 . In addition, even if the specimen TP is made of a material that is easily damaged, the parallelism can be adjusted while applying a minute test force. I never end up doing it.

In the above embodiment, the angle adjustment platen 41 is composed of the platen portion 42, the rod portion 43, and the spherical surface portion 44, but the configuration of the angle adjustment platen 41 is not limited to this. For example, the platen portion 42, the rod portion 43, and the spherical portion 44 may be integrated. The angle adjusting platen 41 has at least a platen portion 42 and a spherical portion 44, and may have any configuration as long as it is rotatable and swingable with respect to the load axis L of the material testing machine 1. good too.

In the above-described embodiment, the first wedge member 51, the second wedge member 52, and the screw member 53 are used as fixing portions for fixing the position of the angle adjustment platen 41. It is not limited to these. For example, members other than the screw member 53 may be used as long as the second wedge member 52 can be moved with respect to the first wedge member 51 . Alternatively, instead of the wedge mechanism, a hydraulic cylinder, an electromagnet, or the like may be used to fix the position of the angle adjustment platen 41 . However, by using a wedge mechanism composed of the first wedge member 51, the second wedge member 52, and the screw member 53, the position of the angle adjustment platen 41 can be easily fixed with a simple configuration.

Moreover, in one embodiment mentioned above, although the example using the basket-shaped jig|tool 30 was demonstrated, it is not limited to this. For example, the basket-shaped jig 30 may be omitted and the compression test jig 40 may be fixed to the load cell 16 using a predetermined joint or the like. In this case, the mount 36 holding the specimen TP is fixed to the substrate 11 . Even when the basket-shaped jig 30 is omitted, the parallelism is adjusted according to the procedure shown in the flow chart of FIG.

Although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other aspects conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention.

1: material testing machine, 40: compression test jig, 41: angle adjustment platen, 42: platen portion, 44: spherical portion, 46: casing, 51: first wedge member, 52: second wedge member, 53: screw Element

Claims (4)

A compression test jig used in a material testing machine,
a platen having at least a spherical portion and a platen portion;
a holding portion that accommodates the spherical portion and holds the platen rotatably and swingably with respect to the load shaft of the material testing machine;
A compression test jig comprising a fixing portion that fixes the platen to the holding portion. In the compression test jig according to claim 1,
The fixing portion includes a first wedge member having a first inclined surface, a second wedge member having a second inclined surface facing the first inclined surface, and the second wedge member with respect to the first wedge member. and a screw member for moving the
The fixing section is a compression test jig that fixes the platen to the holding section by pressing the second wedge member toward the holding section using the first wedge member and the screw member. A material testing machine comprising the compression test jig according to claim 1 or 2. A method for adjusting parallelism in the material testing machine according to claim 3,
a contact step of bringing the platen into contact with the end surface of the test piece with a predetermined test force in a rotatable and swingable state with respect to the load shaft of the material testing machine;
an adjusting step of rotating and/or swinging the platen to adjust the parallelism between the end surface of the specimen and the compression surface of the platen portion of the platen;
a determination step of determining whether the predetermined test force decreases after the adjustment step;
a repeating step of repeating the contacting step and the adjusting step until the predetermined test force no longer decreases when the determining step determines that the predetermined test force has decreased.

Images