JP3944722B2 - Material testing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a material testing machine, and more particularly to a material testing machine having a function of automatically collecting a tested specimen after the end of a tensile test.
[0002]
[Prior art]
In a material testing machine that conducts a tensile test, generally, a tensile load is applied to a test piece by gripping both ends of the test piece with a pair of grips and separating one of them from the other. In an ordinary material testing machine, a table and a cross head that approaches and separates from the table in the vertical direction are provided, and grips are attached to the upper surface of the table and the lower surface of the cross head, respectively.
[0003]
When a tensile test is continuously performed on a plurality of test pieces using such a material testing machine, a device equipped with a device for automatically collecting the test pieces after the test has been put into practical use. As a conventional test strip automatic recovery device, for example, a mechanism for gripping and transporting each test strip corresponding to each gripping tool is provided, and by driving and controlling these gripping and transporting mechanisms with preset operations, A configuration in which a test piece after a test is gripped and collected in a collection box or the like is known.
[0004]
[Problems to be solved by the invention]
By the way, in the material testing machine equipped with the conventional test piece automatic recovery device as described above, the recovery device functions effectively if the state of the test piece after the tensile test of a series of test pieces is almost constant, In some cases, the amount of elongation of the test piece is relatively different, or the recovery is difficult depending on the presence or absence of breakage.
[0005]
An object of the present invention is to provide a material testing machine capable of reliably collecting a test piece after the test regardless of the state of the test piece after the test.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the material testing machine of the present invention attaches the upper gripping tool of the upper and lower gripping tools for gripping both ends of the test piece to the cross head, and moves downward by driving the load mechanism. In a material testing machine that applies a tensile load to a test piece by separating it from the gripper of
A test piece collection mechanism for holding the test piece at the end of the test and collecting it at a predetermined position; and a control means for driving and controlling the test piece collection mechanism by one of a plurality of preset collection operations. , comprising a discriminating means for discriminating the state of the definitive test piece at the end of the test,
The test piece recovery mechanism includes a pair of upper and lower gripping / conveying mechanisms respectively corresponding to the pair of upper and lower grippers, and the discriminating means includes a position at the end of the test of the crosshead and a test piece at the end of the test. Based on the measurement result of the applied test force, the magnitude of elongation of the test piece at the end of the test and the presence or absence of breakage are discriminated, and the control means determines the test piece by the following operation based on the discrimination result by the discrimination means. Material testing machine characterized by collecting.
(A) When the elongation of the test piece is small and it is broken; each gripping tool is held after gripping each test piece that has been broken up and down by the upper and lower gripping / conveying mechanisms corresponding to each gripping tool. After opening, the upper gripping / conveying mechanism is moved above the collection position to open the test piece, and then the lower gripping / conveying mechanism is moved above the collection position to open the test piece.
(B) When the elongation of the test piece is small and not broken; after the crosshead is moved a little downward and the load acting on the test piece is removed, the test is performed by the upper and lower gripping / conveying mechanisms. After gripping the top and bottom and the bottom of the piece, each gripping tool is released, and the top and bottom gripping / conveying mechanisms are simultaneously moved to above the collection position to open the test piece.
(C) When the test piece has a large elongation and is ruptured; after gripping each test piece that has been broken up and down by the upper and lower gripping / conveying mechanisms corresponding to each gripping tool, Open and move the lower gripping / transporting mechanism to the upper position of the recovery position to open the test piece, then with the lower gripping / transporting mechanism retracted, the upper gripping / transporting mechanism is recovered. After moving to above the position and lowering, the test piece is opened.
(D) When the elongation of the test piece is large and it is not broken; after the crosshead is moved by a small amount to remove the load acting on the test piece, the test is performed by the upper gripping / conveying mechanism. Open the lower gripping tool while holding the upper part of the piece, then open the upper gripping tool and move the upper gripping / conveying mechanism to above the collection position. Open the test piece in the retracted state.
[0007]
Here, in the present invention, a configuration in which the upper gripping / conveying mechanism is attached to the crosshead (Claim 2) can be suitably employed.
[0008]
The present invention automatically selects an optimal operation according to the state of the test piece at the end of the test without automatically setting the test piece collecting operation by the test piece collecting mechanism as a predetermined operation. It is intended to achieve the intended purpose.
[0009]
That is, in the present invention, as a test piece recovery mechanism, an upper and lower gripping and conveying mechanism is provided corresponding to the upper and lower gripping tools, the state of the test piece at the end of the test, that is, the amount of elongation and the presence or absence of breakage, Are automatically determined, and the specimen collection operation by the upper and lower gripping / conveying mechanisms is determined according to the determination result. Specifically, as shown in (A) to (D), when the test piece breaks because the elongation is small, when the test piece is small and not broken, the test piece grows large and breaks. And when the test piece has a large elongation and is not broken, an optimal operation is performed according to a total of four states. This makes it possible to reliably collect the test piece after the test even if the amount of elongation of the test piece varies or does not break.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing the overall configuration of an embodiment of the present invention.
[0011]
The testing machine main body 1 rotatably supports two screw rods 12a and 12b along the vertical direction on the table 11, and nuts (not shown) are attached to the screw rods 12a and 12b at both ends of the crosshead 13. The crosshead 13 is configured to move up and down by driving a load motor 14 including a speed reducer and rotating the screw rods 12a and 12b.
[0012]
Grip tools 15 a and 15 b are provided on the lower surface of the cross head 13 and the lower surface of the table 11, respectively. These grip tools 15 a and 15 b are opened and closed by high-pressure air supplied from the pneumatic unit 2, respectively. . Both ends of the test piece W are gripped by these gripping tools 15a and 15b, and a tensile load is applied by raising the crosshead 13 in this state. The load acting on the test piece W due to this tensile load is detected by the load cell 16 and taken into the controller 3 every moment.
[0013]
Specimen gripping / conveying mechanisms 4a and 4b are attached to the cross head 13 and the table 11, respectively. Each of the test piece gripping / conveying mechanisms 4a and 4b includes gripping mechanisms 42a and 42b that open and close to hold and open the test piece W at the tips of arms 41a and 41b that rotate around a vertical axis, respectively. The test piece / conveyance mechanisms 4a and 4b are operated by high-pressure air supplied from the pneumatic unit 2. The height relationship between the test pieces / conveying mechanisms 4a, 4b and the gripping tools 15a, 15b is such that the upper test piece / conveying mechanism 4a is slightly below the lower end of the upper gripping tool 15a, and the lower test The piece / conveyance mechanism 4b is slightly above the lower gripping tool 15b.
[0014]
The controller 3 includes a load motor 14, various control valves included in the pneumatic unit 2, that is, direction control valves for opening / closing control of the gripping tools 15 a and 15 b, and arm of the test piece gripping / conveying mechanisms 4 a and 4 b. Drive control signals are supplied to the turning direction control valves 41a and 41b and the opening and closing control valves of the gripping mechanisms 42a and 42b.
Further, the test machine main body 1 is provided with an operation panel 5. By operating a corresponding switch on the operation panel 5, the test piece W can be gripped by the grippers 15a and 15b of the test piece W via the controller 3, or a test can be performed. Start command can be given.
[0015]
Now, in the controller 3, the test is started by raising the crosshead 13 by driving the load motor 14 in response to a test start command, and then the test piece W is broken during the test, for example, a preset test end condition. The load motor 14 is stopped and the crosshead 13 is stopped when a condition such as a time point, a time point when the test piece W reaches a specified elongation, or a time point when the load acting on the test piece W reaches a specified value. Stop. Then, the state of the test piece W at the end of the test is discriminated as shown below, and the test piece gripping / conveying mechanisms 4a and 4b are driven and controlled based on the operation according to the discrimination result. The test piece W is collected in a collection box 6 arranged on the front side of the tester main body 1 in FIG.
[0016]
FIG. 2 is a flowchart showing the contents of the program for collecting the test piece W written in the controller 3. Hereinafter, the operation for collecting the test piece W will be described in detail with reference to FIG.
[0017]
This program starts at the end of the test. First, it is determined whether or not the elongation of the test piece W at the end of the test is large, based on whether or not the position of the crosshead 13 is higher than a preset height, and then the load cell. Whether or not the test piece W is broken is determined from the load data taken every moment from 16. Then, the state of the test piece W is discriminated into one of the four types by the two types of discrimination, and the test piece W is collected by the upper and lower test piece gripping / conveying mechanisms 4a and 4b by the operation according to each state. I do. In other words, depending on the state of the test piece W at the end of the test, the upper and lower test piece gripping / conveying mechanisms 4a and 4b are automatically selected from the four types of operations A to D and executed. It is. In the following description, the origin positions of the upper and lower test piece gripping / conveying mechanisms 4 a and 4 b are above the collection box 6.
[0018]
When the test piece W is not stretched greatly and is broken, the test piece W is recovered under the operation A. The operation procedure is shown in the flowchart of FIG. In this operation A, first, the upper and lower test piece gripping / conveying mechanisms 4a, 4b are simultaneously turned to the test piece W side, and the test pieces W separated vertically by breakage are respectively corresponding to the test piece gripping / conveying mechanisms. After gripping by 4a and 4b, the upper and lower grips 15a and 15b are opened. Next, the upper test piece gripping / conveying mechanism 4 a is returned to the origin position above the collection box 6, the gripping mechanism 42 a is opened, and the upper half of the test piece W is discarded into the collection box 6. Thereafter, the lower test piece gripping / conveying mechanism 4b is returned to the origin position above the collection box 6, the gripping mechanism 42b is opened, and the lower half of the test piece W is discarded into the collection box 6. The reason why the upper side and the lower side are separated in the dumping operation is that the upper side is first, or if the lower side is first, the upper half of the test piece W is the lower test piece gripping / conveying mechanism 4b when dumping the upper side. This is because there is a possibility that the product does not enter the collection box 6 upon hitting.
[0019]
When the test piece W does not extend greatly and the test is completed without breaking, the test piece W is collected under the operation B. The operation procedure is shown in the flowchart of FIG. In this operation B, first, the cross head 13 is slightly lowered to remove the load acting on the test piece W, and then the upper and lower test piece gripping / conveying mechanisms 4a and 4b are simultaneously turned to the test piece W side. Then, the upper and lower parts of the test piece W are respectively gripped, and then the upper and lower grips 15a and 15b are opened. Thereafter, the upper and lower test piece gripping / conveying mechanisms 4 a and 4 b are simultaneously returned to the upper side of the collection box 6, the gripping mechanisms 42 a and 42 b are simultaneously opened, and the test piece W is discarded into the collection box 6.
[0020]
When the test piece W is greatly elongated and then broken, the test piece W is collected under the operation C. The operation procedure is shown in the flowchart of FIG. In this operation C, first, similarly to the operation A, the upper and lower test piece gripping / conveying mechanisms 4a and 4b are simultaneously turned to the test piece W side, and the test pieces W separated in the vertical direction due to the breakage correspond respectively. After gripping by the specimen gripping / conveying mechanisms 4a and 4b, the upper and lower grippers 15a and 15b are opened. Next, the lower test piece gripping / conveying mechanism 4 b is returned to the collection box 6, the gripping mechanism 42 b is opened, and the lower half test piece W is discarded into the collection box 6. Next, the lower test piece gripping / conveying mechanism 4b is turned again to the test piece W side, and then the upper test piece holding / conveying mechanism 4a is turned to the upper side of the recovery box 6 to move the crosshead 13 to the origin, for example. After being lowered to the position, the gripping mechanism 42a is opened, and the lower half test piece W is discarded. Finally, the lower test piece gripping / conveying mechanism 4b is returned to the turning state.
[0021]
By this operation, when the upper half test piece W is discarded, the lower gripping / conveying mechanism 4b is not obstructed, and the crosshead 13 is lowered and the gripping mechanism 42a is brought close to the collection box 6 and discarded. It can be surely dumped into the collection box 6.
[0022]
When the test piece W is greatly elongated and the test is completed without breaking, the test piece W is collected under the operation D. The operation procedure is shown in the flowchart of FIG. In this operation D, first, similarly to the operation B, after the cross head 13 is slightly lowered to remove the load acting on the test piece W, the upper and lower test piece gripping / conveying mechanisms 4a and 4b are simultaneously tested. The test piece W is turned to the side of the piece W, and the test piece W is held by the upper test piece holding / conveying mechanism 4a. In this state, the lower gripping tool 15b is opened. As a result, the test piece W that has been greatly extended without breaking is shrunk, and in this state, the upper gripping tool 15a is opened, and the upper test piece gripping / conveying mechanism 4a is moved to the origin position above the collection box 6. The rotation is returned, the gripping mechanism 42a is opened, and the test piece W is discarded. At this time, since the lower test piece gripping / conveying mechanism 4b is pivoted toward the test piece W, there is no interference when the test piece W is dropped. Thereafter, the lower test piece gripping / conveying mechanism 4b is returned to the origin.
[0023]
In the above embodiment, the elongation amount of the test piece W is determined from the position of the crosshead 13 at the end of the test, and whether or not the test piece W is broken is determined from the output of the load cell 16. This determination may be performed by other means. For example, the test piece at the end of the test may be photographed with a video camera, and the video output may be subjected to image processing to determine the amount of elongation and breakage of the test piece.
[0024]
Further, the specific configuration of the test piece gripping / conveying mechanism is not limited to that described in the above-described embodiment, and it is needless to say that a mechanism having another known configuration can be adopted.
[0025]
【The invention's effect】
As described above, according to the present invention, the state of the test piece at the end of the test is automatically determined, and the test piece recovery mechanism is controlled based on the operation according to the determination result. Regardless of the amount of elongation or the presence or absence of breakage, it is possible to reliably collect the test piece after the end of the test.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an overall configuration of an embodiment of the present invention.
FIG. 2 is a flowchart showing the contents of a program for collecting a test piece written in a controller according to an embodiment of the present invention.
FIG. 3 is a flowchart showing a procedure of operation A in the flowchart of FIG. 2;
4 is a flowchart showing a procedure of an operation B in the flowchart of FIG. 2;
FIG. 5 is a flowchart showing a procedure of an operation C in the flowchart of FIG.
6 is a flowchart showing a procedure of an operation D in the flowchart of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Test machine body 11 Table 12a, 12b Screw rod 13 Cross head 14 Load motor 15a, 15b Grasping tool 16 Load cell 2 Pneumatic unit 3 Controller 4a, 4b Test piece gripping / conveying mechanism 41a, 41b Arm 42a, 42b Holding mechanism 6 Collection box W Test piece

Claims (2)

By attaching the upper gripping tool of the pair of upper and lower gripping tools gripping both ends of the test piece to the crosshead and separating the gripping tool from the lower gripping tool by driving the load mechanism, In a material testing machine that applies a tensile load,
A test piece collection mechanism for holding the test piece at the end of the test and collecting it at a predetermined position; and a control means for driving and controlling the test piece collection mechanism by one of a plurality of preset collection operations. , comprising a discriminating means for discriminating the state of the definitive test piece at the end of the test,
The test piece recovery mechanism includes a pair of upper and lower gripping / conveying mechanisms respectively corresponding to the pair of upper and lower grippers, and the discriminating means includes a position at the end of the test of the crosshead and a test piece at the end of the test. Based on the measurement result of the applied test force, the magnitude of elongation of the test piece at the end of the test and the presence or absence of breakage are discriminated, and the control means determines the test piece by the following operation based on the discrimination result by the discrimination means. Material testing machine characterized by collecting.
(A) When the elongation of the test piece is small and it is broken; each gripping tool is held after gripping each test piece that has been broken up and down by the upper and lower gripping / conveying mechanisms corresponding to each gripping tool. After opening, the upper gripping / conveying mechanism is moved above the collection position to open the test piece, and then the lower gripping / conveying mechanism is moved above the collection position to open the test piece.
(B) When the elongation of the test piece is small and not broken; after the crosshead is moved a little downward and the load acting on the test piece is removed, the test is performed by the upper and lower gripping / conveying mechanisms. After gripping the top and bottom and the bottom of the piece, each gripping tool is released, and the top and bottom gripping / conveying mechanisms are simultaneously moved to above the collection position to open the test piece.
(C) When the test piece has a large elongation and is ruptured; after gripping each test piece that has been broken up and down by the upper and lower gripping / conveying mechanisms corresponding to each gripping tool, Open and move the lower gripping / transporting mechanism to the upper position of the recovery position to open the test piece, then with the lower gripping / transporting mechanism retracted, the upper gripping / transporting mechanism is recovered. After moving to above the position and lowering, the test piece is opened.
(D) When the elongation of the test piece is large and it is not broken; after the crosshead is moved by a small amount to remove the load acting on the test piece, the test is performed by the upper gripping / conveying mechanism. Open the lower gripping tool while holding the upper part of the piece, then open the upper gripping tool and move the upper gripping / transporting mechanism to above the collection position. Open the test piece in the retracted state. The material testing machine according to claim 1, wherein the upper gripping / conveying mechanism is attached to the crosshead .

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