JP2003106965A - Material testing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a material testing machine preventing collision of a crosshead to a test piece or the like for a next test even when there is a remaining test piece after a test or a change in size or the like of a next test piece. SOLUTION: A light emitter LG and a light receiver DT are oppositely arranged facing the test piece 9 on both struts 2 between a machine base 1 and the crosshead 4, and they are composed so that they can be displaced in a test piece axial direction by a displacing mechanism comprising a wire W and pulleys P1-P4. Accordingly, the light emitter LG and the light receiver DT detect a remaining rupture piece or the like and its position after a test, a return position of the crosshead for a next test is controlled by a program and adjusted, and collision of the crosshead 4 to the rupture piece is resolved.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a base of a testing machine,
Test by applying a tensile or compression load to the test piece between this machine base and the crosshead by the relative displacement with the crosshead that is installed between both columns that are suspended on both sides of this machine base. Material testing machine.

[0002]

2. Description of the Related Art In a material testing machine, more specifically, a material testing machine using a static load such as a tensile testing machine or a compression testing machine, a test piece is usually held between two chucks, and one chuck is used as a base ( It is fixed on the fixed side) and the other chuck is installed on the crosshead etc. (movable side) and a tensile load is applied to the test piece by the relative displacement between the machine base and the crosshead to perform a tensile test, etc. is there. In the case of the compression test, the chuck may serve as a platen.

FIG. 4 shows the main part of the tensile tester, and FIG. 5 shows the main part of the compression tester. That is, in FIG. 4, S is a test piece, and this test piece S is the upper and lower chucks GK.
The upper chucks GK of the two chucks GK are hung between the crossheads CH via the adjusting tool R and the load cell (load cell) LS, while the lower chucks GK are installed on the machine base TD. There is. Although not shown in FIG. 4, the crosshead CH is vertically movably installed on the columns MT on both sides and is vertically displaced by, for example, a screw feed mechanism provided inside the column MT. . On the other hand, the machine base TD is a fixed base of the tester, and the support MT
It is provided together with. The rotation driving mechanism of the above-described screw feeding mechanism and the like are installed inside the machine base TD. When the crosshead CH is displaced upward with respect to the machine base TD by the drive mechanism and the screw feed mechanism, a tensile load is applied to the test piece S, and the test piece S extends and finally breaks.
S1 is the upper fragment and S2 is the lower fragment.

The tensile load is measured by a load cell LS. The load meter LS converts the load value into an electric signal and outputs the electric signal, which is displayed on a display device or the like (not shown). The adjusting tool R is for aligning the load axis with the axis of the load meter LS, and ensures correct load measurement. When the test is over, both fragments S
In Nos. 1 and S2, the crosshead CH is operated to return to the original state while being held by the chuck GK, that is, the crosshead CH is displaced downward and both chucks GK move to their original positions.
That is, the control circuit of the material testing machine, which will be described later, is set with a program that is designed to automatically and continuously perform the test operation and the up / down displacement of the crosshead for that purpose. According to this program, load, crosshead recovery after the test, etc. are automatically performed. In the case of the example shown in the figure, both fragments S from the chuck GK returned to the original position
1 and S2 are removed, and the next test piece is gripped by the manual operation of the operator.

In the case of the compression test shown in FIG. 5, the test piece S3 is sandwiched between the lower platen PT and the upper platen PB, and the crosshead CH is displaced downward along the support column MT so that the test piece is moved. A compressive load is applied to S3. The load is measured by the load cell LS. When the test piece S3 is compressed and destroyed to complete the test, the test piece S3 is removed,
The crosshead CH is operated by the operator's control device.
Is displaced to its original position (upward). Then, it stands by until the next test piece is placed.

[0006]

In both the tensile test and the compression test, after the test is completed, the crosshead CH is automatically returned or is operated by the operator's operation of the control device as described above. In this case, The crosshead CH may collide with the test piece, that is, the broken lower fractured piece S2. This is because, for example, in the case where the test piece S is a peculiar material and is very malleable, it may extend longer than a normal test piece before breaking. In that case, the returning operation of the crosshead CH automatically starts after the break, but in the automatic setting of the control device, if the returning amount is set as a normal test piece, the returning operation becomes a long distance, and the upper broken piece S
1 and the lower fracture fragment S2 collide, or the upper chuck GK collides with the lower fracture fragment S2. Even in the case of the compression tester, for example, as shown in FIG. 5, when the test is performed on the test piece S3 and the size is set in the control device to perform the test, the test having a suddenly different size is performed. When performing a compression test on the piece S4, although the setting must be changed, if the crosshead CH is immediately returned by automatic control, the upper platen P
B collides with the test piece S4.

Such a collision of the chuck or platen with a test piece or a fragment causes the load at that time to be detected by the load cell LS, which exceeds the limit.
Is provided so as not to displace, that is, an automatic stop mechanism of the crosshead CH due to a collision is provided. However, this automatic stop mechanism does not stop when a certain load is not applied and detects it, and the limit load may damage the chuck GK, the crosshead CH, and the load mechanism. The present invention aims to provide a material testing machine that solves such problems.

[0008]

In order to solve the above problems, the material testing machine provided by the present invention determines the presence or absence of a test piece and its position between the machine base and the crosshead after the test is completed. A test piece detecting mechanism for detecting is provided. When the presence and the position of the test piece are detected by this detection mechanism, the displacement of the crosshead is adjusted before the chuck and the platen reach that position. Further, the material testing machine of the present invention includes a displacement mechanism that displaces the test piece detection mechanism along the support. Therefore, the return of the crosshead is adjusted according to the extension of the test piece.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The material testing machine provided by the present invention will be described below with reference to the embodiments shown in the drawings. FIG. 1 is a tensile material testing machine for performing a tensile test by carrying out the material testing machine according to the present invention, and further, by rotatably driving the screw rod 10, the crosshead 4 is displaced up and down and the test load is electrically measured. Is shown, and a part thereof is shown in cross section for the sake of easy understanding of the main part of the invention.

Reference numeral 1 denotes a machine base, but a mechanism for rotationally driving the screw rod 10 is installed inward. That is, 13 is an electric motor, and a gear G is attached to this output shaft. A timing belt 15 is meshed with the gear G. The timing belt 15 is an endless belt and is fixed to a pulley 16 fixed below the left screw rod 10 and a pulley 16 fixed below the right screw rod 10. It is stretched around a pulley. Therefore, the rotation output of the electric motor 13 is transmitted via the timing belt 15 to the screw rod 10
Be transmitted to. As shown in the figure, the screw rod 10 is rotatably held by a thrust bearing device 17 without moving up and down. A nut 4N integrated with the crosshead 4 is screwed onto the screw rod 10, and the crosshead 4 is displaced up and down by the rotation of the screw rod 10. 3 is a yoke.

When the crosshead 4 is displaced upward due to the screw rod 10 being rotationally driven by the above-described structure, the chuck 7 suspended from the crosshead 4 via the load meter 5 and the lower portion of the chuck 7 are suspended. A tensile load is applied to the test piece 9 held between the chuck 8 and the machine stand 1. Reference numeral 6 is an adjusting tool. Although the above-mentioned configuration is not different from the conventional one, the present invention has the above-described configuration and the machine base 1 and the crosshead 4 after the test is completed
A test piece detection mechanism for detecting the presence or absence of the test piece 9 and the position between the two are provided.

That is, a guide frame 2M is vertically provided on the columns 2 on both sides so as to face each other and parallel to the test axis, and the light emitters LG are arranged to face the guide frame 2M.
And a light receiver DT are provided. When the light from the light emitter LG is emitted to the test piece 9 and the light is blocked by the test piece 9, the light receiver DT does not receive the light and the presence of the test piece 9 is detected. On the other hand, when the light from the light emitter LG is received by the light receiver DT, it means that the test piece 9 or the fragment is not present. The light receiver DT outputs a detection signal (electrical signal) when it receives light. This detection signal is input to the control circuit 14 via the lead wire EL,
The presence / absence signal of the test piece 9 is input.

The basic feature of the present invention is that the present invention is provided with the detection mechanism for detecting the presence or absence of the test piece 9 between the machine base 1 and the crosshead 4. By the way, in this type of material testing machine, not only is the presence or absence of the test piece 9 or the broken piece detected between the machine base 1 and the crosshead 4, specifically between the chucks 7 and 8, if there is any It is desirable to detect its location. In other words, after the test is completed and before the next test is started, it is possible to know what length of fragment is present as long as it is a fragment and what the length of the next new test piece is. This is because the conditions are to prevent the crosshead from colliding and to smoothly mount a new test piece.

Therefore, in the present invention, the above-described test piece detecting mechanism is constructed so as to be displaceable along the column 2. An embodiment of this displacement mechanism will be described below with reference to FIG. Light emitter LG and light receiver D
T is a lifting frame 11 via holding plates H1 and H2,
It is integrally attached to 12. Two lifting frames 1
Two wires W are connected to the upper and lower parts of the wires 1 and 12, respectively. As shown in the figure, the two wires W are connected endlessly through both elevating frames 11 and 12, and are connected to the pulleys P1 to P6 arranged inside the machine base 1 and the column 2. It is wound.

The pulley P1 and the pulleys P2 and P6, and the pulley P4 and the pulleys P3 and P5 are arranged in the column 2 in parallel with the direction of the screw rod 10, and therefore the lifting frame 11,
12, the elevating frames 11 and 12 are vertically displaced along the axis of the screw rod 10, that is, along the test axis direction.
With such a configuration, the light emitter LG and the light receiver DT are completely synchronized, and if the light emitter LG is displaced upward in the same direction, the light receiver DT is also displaced upward in the same direction by the same displacement amount.

Therefore, the light receiver DT can accurately receive the light emitted from the light emitter LG. In addition, this displacement amount is such that the rotation amount of the electric motor 20 is introduced into the control circuit 14 as an electric signal, and the displacement amount of the light receiver DT and the output signal by the light reception of the light receiver DT are input to the control circuit. It has become. The holding plates H1 and H2 are provided with holes A through which the screw rod 10 is passed.

With the above-described structure, for example, in FIG. 2, when the light emitter LG and the light receiver DT are sequentially displaced upward from below, the light receiver DT receives light at the position of the height H1. A detection signal is output, and a signal as a displacement amount of the light receiver DT is also output. Based on these signals, the control circuit 14 detects the presence of a fragment and the position of the fragment (height H
1) will be detected. Therefore, the upper fragment 9
Fragment 9 with and without U and lower fragment 9D
The upper end position of D is detected. According to the presence / absence and position detection results, when the crosshead 4 is displaced downward for the next test, both fracture fragments 9U and 9D are present, and the fracture point position is detected. The displacement is controlled, and in the case of FIG. 2, the lower end of the upper fragment 9U has a height H1.
The downward displacement is stopped before reaching the position.

In the above description, the embodiment in which the detection mechanism composed of the light emitter LG and the light receiver DT is displaced by another drive mechanism regardless of the displacement of the crosshead 4 has been described. Can also be a method of synchronizing this detection mechanism with the displacement of the crosshead 4.

This method is particularly advantageous for the compression test as shown in FIG. That is, in FIG. 3, the light emitter LG and the light receiver DB face each other and are suspended in the lower direction of the load meter 5 via the hanger HG. The platen 18 is directly connected to the load meter 5, and the compression load is measured via the platen 18. 19 is a lower platen.

After the compression test of the test piece S3, the next test piece S4 is performed.
Is prepared, the return operation of the crosshead 4 is started. In this case, the light emitting device LG and the light receiving device DT use the test piece S4.
Of the test piece S4 and its top position (H2) are detected. Upon detection, the signal is output from the transmitter EM, and when the wireless receiver PR receives the signal, the detection signal is input to the control circuit 14 via the lead wire EL. A signal for stopping the displacement drive system of the crosshead 4 is input to the electric motor 13 based on this signal input, and the return displacement of the crosshead 4 is stopped. Therefore, the platen 18 does not collide with the test piece S4.

The characteristics of the material testing machine provided by the present invention are as described above in detail, but the present invention is not limited to the above and illustrated examples, and includes various modifications. This modification will be described below. First, the detection mechanism for detecting the presence (presence or absence) of the test piece 9 and the fragments 9U, 9D is not limited to an optical method, and a method of detecting it by a magnetic variable may be considered. Not only the method but also a contact type detection mechanism using a contact piece such as a feeler can be used. In this case, the detection accuracy can be improved.

Next, a displacement mechanism for displacing the detection mechanism along the support column 2, the illustrated example is an endless wire W
Is wound around six pulleys P1 to P6, and the light emitting device LG and the light receiving device DT are arranged on the wires located on both sides, but the screw feed mechanism is arranged on both sides in the same way as the double screw rod 10. It is also possible to employ a screw feed mechanism system in which the light emitter and the light receiver are respectively moved up and down by being provided and rotating the screw rod in synchronization. Alternatively, it is possible to adopt a system in which endless wires are circulated on both sides and both endless wires are synchronously driven, and a light emitting device and a light receiving device are attached to the respective endless wires for synchronous displacement. Further, as the type of material testing machine, the present invention can be applied to a universal testing machine using a hydraulic load in addition to the electric measuring method as shown in the drawing and the screw feed load method using a screw rod.

The detection mechanism for detecting the presence or absence of the test piece and the displacement mechanism for displacing the detection mechanism for detecting the position may be integrally connected. Further, a detection signal from the detection mechanism and a displacement signal corresponding to the displacement amount from the displacement mechanism are guided to the control circuit 14, and a signal for controlling the automatic operation of the testing machine set in the program is generated from the presence or absence of the test piece and its position. Although the control circuits for doing so are not shown, these can include various circuits that can be created by one of ordinary skill in the electrical arts.

[0024]

Since the material testing machine provided by the present invention is as described above in detail, the presence or absence of the test piece and the fragment after the test is properly detected and the position thereof is also detected, and the crosshead of the crosshead is detected. Since the return is controlled, it is possible to prevent the collision with the remaining test piece during the return operation of the crosshead. Even if the size of the test piece changes abruptly next time, the program control operation is adjusted to prevent the collision and the test equipment is not damaged.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing the structure of a material testing machine according to the present invention.

FIG. 2 is a diagram illustrating the operation of the material testing machine according to the present invention.

FIG. 3 is a diagram illustrating the operation of the material testing machine according to the present invention.

FIG. 4 is a diagram showing a tensile test method in a conventional material testing machine.

FIG. 5 is a diagram showing a compression test method in a conventional material testing machine.

[Explanation of symbols]

1 ... Machine stand 2… Support 4 ... Crosshead 5… Load cell 10 ... screw rod 11, 12 ... Lifting frame H1, H2 ... Holding plate LG ... Light emitter DT ... light receiver W ... wire P1, P2, P3, P4, P5, P6 ... Pulley 13, 20 ... Electric motor 14 ... Control circuit

Claims (3)

[Claims] 1. A test piece between the machine base and the crosshead is caused by a relative displacement between a machine base of the test machine and a crosshead installed between both columns vertically installed on both sides of the machine base. On the other hand, in a material testing machine that tests by applying a tensile or compressive load, a test piece detection mechanism for detecting the presence or absence of the test piece and its position between the machine base and the crosshead after the test is provided, and the signal of this detection mechanism is provided. The material testing machine is characterized in that the displacement of the crosshead is adjusted by. 2. The test piece between the machine base and the crosshead is caused by relative displacement between the machine base of the test machine and the crosshead installed between both columns vertically installed on both sides of the machine base. On the other hand, in a material testing machine that tests by applying a tensile or compression load, a test piece detection mechanism that detects the presence and the position of the test piece between the machine base and the crosshead after the test is provided, and this test piece detection is performed. A material test, comprising: a displacement mechanism that displaces the mechanism along the support column; and an adjustment mechanism that adjusts a relative displacement of the crosshead with respect to the machine base based on a detection output signal from the detection mechanism. Machine. 3. The test piece between the machine base and the crosshead is caused by the relative displacement between the machine base of the test machine and the crosshead installed between both columns vertically installed on both sides of the machine base. On the other hand, in a material testing machine that tests by applying a tensile or compression load, a test piece detection mechanism that detects the presence and the position of the test piece between the machine base and the crosshead after the test is provided, and this test piece detection is performed. A displacement mechanism that displaces the mechanism along the support column, a adjusting mechanism that adjusts relative displacement of the crosshead with respect to the machine base based on a detection output signal from the detection mechanism, and a detection output signal based on displacement of the detection mechanism. A material testing machine comprising an adjusting mechanism for adjusting the relative displacement of the crosshead with respect to the machine base based on the above.