JP2564777Y2 - Material testing machine - Google Patents

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 having a mechanical grip for gripping a test piece, and is particularly suitable for use in various test tanks for realizing a corrosive atmosphere or the like.

[0002]

2. Description of the Related Art FIG. 7 is a front view showing an example of a conventional mechanical grip provided in a material testing machine, and FIG. 8 is a right side view. In these figures, 1 is an upper grip connected to a fixed shaft of the material testing machine, and 2 is a lower grip connected to a load shaft. The upper gripping tool 1 is formed by connecting a pair of upper gripping teeth 3 and 4 with bolts 7, and a test piece TP is gripped between the gripping teeth 3 and 4. Similarly,
The lower grip 2 also includes a pair of lower grip teeth 5 and 6 connected by bolts 7.

[0003] As shown in Figs.
In order to grip the test piece TP with the test piece 2, first, loosen the bolt 7 and widen the interval between the upper grip teeth 3, 4 and the lower grip teeth 5, 6, and place the test piece TP between these grip teeth 3 to 6. Then, the bolt 7 is tightened, and the test piece TP is clamped and gripped by the gripping teeth 3 to 6.

However, the gripping tools 1 and 2 as shown in FIGS. 7 and 8 apply not only a simple tensile test for simply applying an increasing tensile force to the test piece TP but also apply an increasing or decreasing tensile force. Although there is an advantage that the test piece TP can be surely gripped even in a tensile-tensile test, there are the following problems. That is, the grips 1 and 2 need to loosen or tighten the bolts 7 each time the test piece TP is gripped and removed, and the test time for one test piece TP is long. When the test time is very short, the test piece T for the entire test time is relatively insignificant.
There is a problem that the ratio of the time for attaching and detaching P becomes large, and it takes time and also prolongs the test time.

FIGS. 9 and 10 show grippers that can solve the above-mentioned problems. FIG.
FIG. 10 is a front view showing another example of a conventional mechanical grip, and FIG.
Is a right side view. In these figures, reference numeral 10 denotes a gripper connected to a fixed shaft or a load shaft of the material testing machine. The gripper 10 includes a gripper body 11 and a pin 1.
6 and a pair of gripping teeth rotatably supported by the gripper body 11 via the pin 6 and similarly rotatably supported by the arms 12 and 13 via the pin 17. 14 and 15. Gripping teeth 14, 15
The arm 1 is pivotally supported by a pin 18 so as to be rotatable relative to each other, and a portion on the base end side of the pin 18 is opened right and left.
Together with 2 and 13, a pantograph link mechanism is formed. A spring 19 is interposed between the pins 17.

A grip 1 as shown in FIGS. 9 and 10
In order to grip the test piece by using the pins 16 and 18 against the urging force of the spring 19, as shown in FIG.
Deform the link mechanism to reduce the distance between them (Fig. 1
(1) The direction between the tips of the gripping teeth 14 and 15 is expanded (FIG. 12), and the test piece TP is inserted between the gripping teeth 14 and 15. Next, when the force applied to the link mechanism is removed, as shown in FIG. 11, the distance between the pins 16 and 18 is widened by the return force of the spring 19, and the gripping teeth 14 and 15 are closed, so that the gripping teeth 14 and 15 are closed. The test piece TP is gripped during 15. Thereafter, FIG.
When loading a tensile force as indicated by the middle arrow P _1, it is urged in the drawing downward teeth 14, 15 is brought to grasp the pin 1
Distance spreads such force between 6 and 18 acts, the test piece TP with a stronger force clamping force as shown by the arrow P ₂ from the teeth 14, 15 to the test piece TP acts gripping the gripping Is done. As described above, the gripping tool 10 is relatively quick and the test piece T
There is an advantage that the attachment / detachment work of P can be performed.

[0007]

However, the gripping tool 10 as shown in FIGS. 9 and 10 can surely hold the test piece TP when performing a simple tensile test, but performs a tensile-tensile fatigue test. In this case, if the test piece TP is loaded in a direction in which the tensile force is weakened, the gap between the gripping teeth 14 and 15 is expanded, and the gripping force is weakened. Therefore, there is a problem that it is difficult to apply the grip 10 to a tensile-tensile fatigue test. The gripping force of the test piece TP is given only by the urging force of the spring 19 when no tensile force acts on the test piece TP.
There is also a problem that the gripping force may be insufficient depending on the shape of the.

[0008] An object of the present invention is to provide a material testing machine having a mechanical gripper capable of quickly attaching and detaching a test piece and having a wide application range to various tests.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 showing an embodiment, the present invention is a test using a pair of gripping teeth 50 and 51 provided so as to be detachable from each other. The invention is applied to a material testing machine with a mechanical gripper 30 for gripping a piece TP, and the above-mentioned object is to connect the gripper gripper 30 to the gripping teeth 50, 51 and pull the test piece TP into tension. A booster mechanism TG that is urged in a direction over a dead center when a force is applied, and the pair of gripping teeth 50 and 51 are relatively moved closer by moving the booster mechanism TG near the dead center. Let the test piece TP
This is achieved by providing an operation unit 63 for gripping the.

[0010]

[Action] Insert the test piece TP between the gripping teeth 50 and 51,
When the booster mechanism TG is moved to the vicinity of the dead center using the operation unit 63, the pair of gripping teeth 50 and 51 are relatively close to each other, and the test piece TP is gripped between the gripping teeth 50 and 51.
If the booster mechanism TG is in the vicinity of the dead center, a large force is required to move the booster mechanism TG in a direction over the dead center. Accordingly, even when the tensile force is applied to the test piece TP and the booster mechanism TG is urged in a direction to go over the dead center, the gripping of the test piece TP by the gripping teeth 50 and 51 is performed stably. On the other hand, if the booster mechanism TG is moved away from the dead center using the operation unit 63, the gripping of the test piece TP by the gripping teeth 50 and 51 is released.

In the means and means for solving the above-mentioned problems which explain the configuration of the present invention, the drawings of the embodiments are used to make the present invention easier to understand. However, the present invention is not limited to this.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; 1 to 3 are views showing an embodiment of a mechanical grip provided in the material testing machine of the present invention. FIG. 1 is a front view, FIG. 2 is a partially cutaway right side view, and FIG. It is arrow sectional drawing in alignment with cc 'of FIG. In these figures, reference numeral 30 denotes a mechanical gripper, which is connected to an upper gripper fixed to a fixed shaft of a material testing machine (not shown) and a load shaft 32 of the material testing machine. And a lower grip 31. The configuration of the upper grip and the lower grip 31 is substantially the same. Therefore, only the lower grip 31 is shown in the illustrated example, and the description of the upper grip is omitted.

A screw rod 34 is fixed to the base end of the gripper main body 33 of the lower gripper 31, and the base end of the screw rod 34 is screwed to the distal end of the load shaft 32 to form a lock nut 35.
It is fixed at. Further, a main body 37 of an opening / closing mechanism 36 extending right and left of the screw rod 34 is provided at an intermediate portion of the screw rod 34.
Is provided slidably, and an adjusting screw 39 is screwed to the screw rod 34 via a disc spring 38 at the base end of the main body 37. Pins 4 are provided on the left and right ends of the main body 37, respectively.
Arms 42 and 43 are provided rotatably via 0 and 41. One pin (left pin in FIG. 1) 40
As shown in FIGS. 4 and 5, the intermediate portion 40a supporting the arm 42 is formed to have a larger diameter than both end portions 40b inserted into the main body 37, and the center O of the intermediate portion 40a is formed.
′ Is an eccentric pin that is eccentric with respect to the rotation center O on the main body 37 side. Therefore, the eccentric pin 40 and the arm 42 constitute a so-called toggle joint mechanism (power boosting mechanism) TG. The dead center of the toggle joint mechanism TG is such that the center O ′ of the eccentric pin 40 is located at the top dead center. (See FIG. 4) and when the center O 'is located at the bottom dead center (see FIG. 5).

Reference numerals 50 and 51 denote a pair of gripping teeth arranged opposite to each other.
4 is connected to the gripper main body 33. Also,
The gripping teeth 50 and 51 are also connected to the tips of the arms 42 and 43 via a bracket 55 and pins 56 to 58, and the arm 54 and the bracket 55
2, 53 and the pins 56, 57 form a parallel link mechanism. In the state where the eccentric pin 40 has reached the top dead center (the state shown in FIG. 4), the distance between the rotation centers of the pins 40, 58 and the pins 41, 58 (arrows A,
B) are set to be substantially equal.

Reference numeral 60 denotes a spring interposed between the opening / closing mechanism main body 37 and the gripper main body 33, and 61 denotes a bolt provided through the opening / closing mechanism main body 37 in the thickness direction. When the center of the pin 40 is located slightly inward from the top dead center (to the right in FIG. 1), the pin 62 protruding from one end of the pin 40 abuts on the bolt 61, whereby the pin 40 is moved to the right in the figure. Is restricted. 63 is a pin projecting from the other end of the eccentric pin 40, 64
Is a work stopper provided at the tip of one of the gripping teeth 51, and X is the load axis of the material testing machine.

In the correspondence between the claims and the embodiment, the toggle joint mechanism TG includes a booster mechanism and a pin 63.
Denotes an operation unit, an opening / closing mechanism main body 37, an adjustment screw 39, a pin 4
The 0, 41, the arms 42, 43, the bracket 55, and the pins 56 to 58 integrally constitute an opening / closing mechanism, and the disc spring 38 constitutes an urging means.

Next, the operation of the gripper 30 of this embodiment will be described. In order to grip the test piece TP with the gripper 30 prior to the test, first, as shown in FIG.
The eccentric pin 40 can be moved in one direction (FIG. 4
5, the center O 'of the eccentric pin 40 is positioned near the bottom dead center as shown in FIG. Due to this rotation, the arm 42 moves downward in the figure, and one bracket 55 connected thereto pivots counterclockwise in the figure around the pin 57 so that one gripping tooth 50 moves leftward in the figure. To open.

In this state, when the adjusting screw 39 is rotated in a predetermined direction to move the opening / closing mechanism body 37 up and down relatively with respect to the screw rod 34, it is constituted by the spring 60, the arm 54, the bracket 55 and the like. By the action of the parallel link mechanism, the gripping teeth 50, 51 open equally to the left and right in the figure. Then, the adjusting screw 39 is rotated to grasp the teeth 50, 51.
The test piece TP is opened so that it can be held lightly.

Next, the eccentric pin 40 is rotated clockwise in FIG. 5 by the lever 70 until the pin 62 comes into contact with the bolt 61, and the eccentric pin 40 is positioned at a position where the center O 'is beyond the top dead center. . By this rotation, as shown in FIG. 4, the arm 42 moves upward in the figure, and one bracket 55 connected to the arm 42 rotates clockwise in FIG. Is closed rightward in the figure, and the test piece TP is gripped between the gripping teeth 50 and 51.
Then, the disc spring 38 is bent by the gripping operation of the test piece TP, and the repulsive force of the disc spring 38 becomes a gripping force on the test piece TP.

Thereafter, the load shaft 32 is driven to drive the test piece TP
When a tensile load is applied to the gripping teeth 50 and 51,
, An upward force is applied, and this force rotates the bracket 55 clockwise in the figure and urges the arm 42 to the left in the figure, but the eccentric pin 40 and the arm 42 are toggled as described above. Since the joint mechanism (power-assisting mechanism) TG is configured, the arm 42
Requires a very large force to move to the left in the figure. Therefore, even if a tensile load is applied, the grip teeth 50, 5
1 reliably holds the test piece TP.

On the other hand, when a compressive load is applied to the test piece TP, a downward force acts on the gripping teeth 50 and 51 in FIG. 4, and this force causes the bracket 55 to rotate counterclockwise in the figure. The arm 42 is urged rightward in the figure,
Since the movement of the arm 42 to the right in the figure is restricted by the contact of the pin 63 and the bolt 61, the bracket 55 is not further rotated. Therefore, even if a compressive load is applied, the gripping of the test piece TP by the grip teeth 50 and 51 is reliably performed.

Therefore, according to the material testing machine of this embodiment,
By rotating the eccentric pin 40, the gripping operation of the test piece TP can be performed, and the work of attaching and detaching the test piece TP can be performed simply and quickly. Moreover, the gripper of this embodiment can be applied not only to a simple tensile test but also to a tensile-compression fatigue test and a tensile-tensile fatigue test.
It has an excellent advantage that the range of application to various tests is very wide. In addition, since the gripping force of the test piece TP is given by the toggle joint (power boosting) mechanism TG, the test piece TP can be gripped with a stronger force than gripping by a spring or the like, and the shape of the test piece TP depends on the shape. It is possible to securely hold the object.

The details of the material testing machine of the present invention are not limited to the above-described embodiment, and various modifications are possible. As an example, in the above-described embodiment, the gripping force of the test piece TP is obtained by the disc spring 39. However, if the test piece TP is an elastic body such as rubber, the gripping teeth 50, 51 are formed by the elastic force of the test piece TP. And the disc spring 39 can be omitted. Similarly, if only the tensile load is applied to the gripper of the present invention, the pin 62, the bolt 6
1 can be omitted, and if the size of the test piece TP is constant, the opening / closing mechanism 36 is omitted and the gripping teeth 5
What is necessary is just to make the opening amount between 0 and 51 constant. Further, in this embodiment, the eccentric cam (pin 40) and the link (arm 42)
Although the boosting mechanism is configured by the above, the boosting mechanism may be configured only by the link.

[0024]

As described in detail above, according to the present invention, the gripping and releasing of the test piece can be performed by operating the booster mechanism by the operation part of the mechanical grip. A detachable operation can be performed reliably and promptly, and a material testing machine having a wide application range to various tests such as a simple tensile test as well as a tensile-tensile fatigue test can be realized.

[Brief description of the drawings]

FIG. 1 is a front view showing a mechanical grip provided in a material testing machine according to an embodiment of the present invention.

FIG. 2 is a partially cutaway right side view of the mechanical grip.

FIG. 3 is a cross-sectional view taken along line cc ′ of FIG. 1;

FIG. 4 is a partially broken front view showing a state where a test piece is gripped by a mechanical grip.

FIG. 5 is a partially broken front view showing a state where a test piece is taken out from a mechanical gripper.

FIG. 6 is a front view showing a lever for rotating an eccentric pin.

FIG. 7 is a front view showing an example of a mechanical grip provided in a conventional material testing machine.

FIG. 8 is a right side view of the mechanical grip shown in FIG. 7;

FIG. 9 is a front view showing another example of a mechanical grip provided in a conventional material testing machine.

FIG. 10 is a right side view of the mechanical grip shown in FIG. 9;

11 is a view showing a state where a test piece is gripped by the mechanical grip shown in FIG. 9;

FIG. 12 is a view showing a state where a test piece is taken out from the mechanical grip shown in FIG. 9;

[Explanation of symbols]

 Reference Signs List 30 gripper 31 lower gripper 32 load shaft 33 gripper body 34 screw rod 36 opening / closing mechanism 37 opening / closing mechanism body 38 disc spring 39 adjusting screw 40 eccentric pin 42 arm 50, 51 gripping tooth 55 bracket 56-58 pin 61 bolt 62, 63 pin 70 lever TG toggle joint mechanism TP test piece

Claims (1)

(57) [Scope of request for utility model registration] 1. A material testing machine provided with a mechanical gripper for gripping a test piece with a pair of gripping teeth provided so as to be able to be separated from and separated from each other, wherein the gripping tool is:
A booster mechanism that is connected to the gripping teeth and is urged in a direction to get over the dead center when a tensile force is applied to the test piece, and the pair of the booster mechanisms is moved by moving the booster mechanism near the dead center. A material testing machine, comprising: an operation unit configured to grip the test piece with gripping teeth relatively close to each other.