Material testing machine

Abstract

To provide a testing machine capable of simplifying replacement work of members.SOLUTION: A material testing machine (1) includes a first holding part (10) configured to hold a first end (TP1) of a test piece (TP), a second holding part (40) supported so as to be movable toward and away from the first holding part (10) and configured to hold a second end (TP2) of the test piece (TP), a sensor (49) configured to move integrally with the second holding part (40), a sensor cable (50) extending from the sensor (49), and an information processor (6) to which the sensor cable (50) is connected. The sensor cable (50) is provided with fixed cables (52, 54) and an attachment / detachment cable (60) detachably connected to the fixed cables (52, 54), and the attachment / detachment cable (60) has flexibility and is provided at a position where the degree of bending changes according to the movement of the second holding section (40).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a materials testing machine. [Background technology]

[0002] Patent Document 1 discloses a materials testing machine that includes a crosshead that moves up and down depending on the size of the test object, a load cell attached to the crosshead that measures the test force applied to the test object, and a control device that receives the measurement results of the load cell as a signal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-108007 Summary of the Invention [Problem to be solved by the invention]

[0004] In general, in a testing machine such as that described in Patent Document 1, the control device and the load cell are connected by a cable such as a signal line. In such a materials testing machine, the cable is repeatedly bent as the crosshead moves repeatedly, which places a load on the cable and requires replacement. In this case, the problem was discovered that, in conventional materials testing machines, the entire cable had to be replaced, even though the damage to the cable was limited to the portion that was repeatedly bent. The present invention provides a materials testing machine that can easily replace a sensor cable. [Means for solving the problem]

[0005] A first aspect of the present invention relates to a materials testing machine comprising a first holding portion that holds a first end of a test piece, a second holding portion that is supported so as to be movable toward and away from the first holding portion and that holds a second end of the test piece, a sensor that moves integrally with the second holding portion, a sensor cable extending from the sensor, and an information processing device to which the sensor cable is connected, wherein the sensor cable comprises a fixed cable and a detachable cable that is detachably connected to the fixed cable, and the detachable cable is flexible and is positioned so that its degree of bending changes in accordance with the movement of the second holding portion. [Effects of the Invention]

[0006] According to the present invention, since only the detachable cable, which changes its bending state, is susceptible to damage, the sensor cable can be easily replaced by simply replacing the detachable cable. Therefore, it is possible to provide a materials testing machine that makes it easier to replace the sensor cable than if the entire sensor cable were replaced. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a plan view of a materials testing machine according to an embodiment of the present invention. FIG. [Figure 2] 10 is a side view seen from the front, schematically showing the relationship between the second holding portion and the relay cable. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The symbol FR in each of the following figures indicates the front of the material testing machine 1 when it is installed on the installation surface G and in normal use, and the symbol LH indicates the left of the material testing machine 1. In the following explanation, each direction is along the direction of the material testing machine 1.

[0009] [1-1.Configuration] [1-1-1. Configuration of material testing machine] FIG. 1 is a plan view of a material testing machine 1 according to an embodiment of the present invention. In FIG. 1, for convenience of explanation, the test specimen TP is indicated by a dashed line, the crosshead fixing cable 52 and the ground fixing cable 54 are indicated by broken lines, and the relay cable 60 is indicated by a two-dot chain line.

[0010] The material testing machine 1 of this embodiment is a so-called horizontal tensile fatigue testing machine. The material testing machine 1 of this embodiment performs a tensile fatigue test by applying a test force to a test piece TP extending in the horizontal direction, that is, in the lateral direction. The test force is a tensile force.

[0011] The test specimen TP is, for example, a rope. However, instead of a rope, the test specimen TP may be, for example, a long member such as a wire, string, or rod, like a rope.

[0012] The material testing machine 1 of this embodiment includes a testing machine main body 2, a control unit 4 that controls the tensile test operation by the testing machine main body 2, and a terminal device 6 that receives the measurement results obtained by the tensile test. The terminal device 6 corresponds to an example of an "information processing device."

[0013] The testing machine main body 2 is placed on an installation surface G. The testing machine main body 2 is equipped with a pair of left and right bridging members 12, 20. The bridging members 12, 20 each extend in the front-to-rear direction (a direction perpendicular to the tensile direction). The bridging members 12, 20 are each fixed to the installation surface G via a predetermined jig or the like. The bridging members 12, 20 extend above the installation surface G with a gap therebetween.

[0014] The pair of left and right bridging members 12, 20 support a pair of front and rear threaded rods 18 extending in the left-right direction (pulling direction). More specifically, a pair of cylindrical supports 14 extending rightward are provided at the front and rear ends of the left bridging member 12. A threaded rod 18 is housed in the supports 14. Thus, the threaded rod 18 is supported on the left bridging member 12 via the supports 14.

[0015] The threaded rods 18 are cylindrical members with a smaller diameter than the support body 14. A thread groove is formed on the outer circumferential surface of the threaded rods 18. The right end of each of the threaded rods 18 is supported by the right-side bridging member 20 located on the opposite side from the support body 14, i.e., the right end side.

[0016] The threaded rod 18 is rotatably supported by the support body 14 and the right-side bridging member 20. A hydraulic pipe 30 is connected to the right-side bridging member 20. A hydraulic drive mechanism (not shown) is housed in the right-side bridging member 20. This hydraulic drive mechanism is configured to be driven by hydraulic pressure from the hydraulic pipe 30. In this embodiment, the threaded rod 18 is configured to be rotatable in both forward and reverse directions by the hydraulic drive mechanism being driven in both forward and reverse directions.

[0017] A second holding portion 40 extending in the front-rear direction is hung across the pair of front and rear threaded rods 18. The second holding part 40 has a crosshead 42 extending in the front-rear direction. A ball screw nut part 44 is provided on each of the crosshead 42's two ends in the front-rear direction. Each of the ball screw nut parts 44 is attached to and supported by the pair of threaded rods 18. Therefore, when the threaded rods 18 rotate forward or backward, the second holding part 40 moves left and right along the threaded rods 18 via the ball screw nut parts 44.

[0018] The second holding part 40 is configured to be movable in the longitudinal direction of the threaded rod 18 between a predetermined close position P1 where it is close to the left bridging member 12 and a distant position P2 where it is farther away from the left bridging member 12 than the close position P1. The second holding part 40 moves linearly along the threaded rod 18.

[0019] Clamps 46, which are fastening devices, are provided on both the front and rear ends of the crosshead 42. When the clamps 46 are tightened, the second holding part 40 is fixed to the threaded rod 18. Therefore, the position of the second holding part 40 in the left-right direction is fixed. When the clamps 46 are loosened, the second holding part 40 becomes movable in the left-right direction.

[0020] A second holding body 48 is provided at the center of the crosshead 42 in the front-to-rear direction (longitudinal direction) via a load cell 49. The second holding body 48 is a device capable of holding the second end TP2 of the test specimen TP. That is, the second end TP2 of the test specimen TP is coupled and connected to the second holding body 48 and held therein. The load cell 49 corresponds to an example of a "sensor."

[0021] A first holding unit body 26, which is an instrument capable of holding a first end TP1 of the test specimen TP, is provided on an extension of the tip side of the second holding unit body 48. The first holding unit body 26 is supported by an actuator 22. In detail, the actuator 22 is provided in the center of the left bridging member 12 in the front-rear direction. The actuator 22 extends in the left-right direction (pulling direction). The actuator 22 is a hydraulic actuator. The actuator 22 includes a piston rod 24. The piston rod 24 extends rightward from the left bridging member 12. A first holding portion main body 26 is provided at the tip portion located on the right side of the piston rod 24.

[0022] That is, in the materials testing machine 1 of this embodiment, the second holding unit 40 is moved between the approach position P1 and the separate position P2 depending on the length of the test specimen TP. Then, the distance between the second holding unit body 48 of the second holding unit 40 and the first holding unit body 26 of the first holding unit 10 is adjusted to match the length of the test specimen TP. Then, the second end TP2 and the first end TP1 of the test specimen TP are held by the second holding unit body 48 of the second holding unit 40 and the first holding unit body 26 of the first holding unit 10, respectively. That is, the test specimen TP is set in the tensile tester body 2. In addition, in the material testing machine 1, after the second end TP2 and the first end TP1 of the test specimen TP are held by the second holding portion body 48 of the second holding portion 40 and the first holding portion body 26 of the first holding portion 10, respectively, the second holding portion 40 may move between an approach position P1 and a distance position P2 depending on the length of the test specimen TP.

[0023] The tensile test operation by the tensile tester main body 2 is controlled by a control unit 4. The control unit 4 is connected to an actuator 22 via a plurality of hydraulic pipes 30. The actuator 22 has its pressure oil direction and amount controlled by the control unit 4, causing the piston rod 24 to reciprocate left and right. As a result, a tensile force is repeatedly applied to the set test piece TP, and a tensile fatigue test is carried out. The tensile force at this time is measured by the load cell 49.

[0024] The load cell 49 is a sensor that measures the test force, which is the tensile load applied to the test piece TP, and outputs the measurement result of the test force as a signal. The load cell 49 is connected to the terminal device 6 via a detection cable 50. The terminal device 6 is a control device that receives the signal of the measurement result of the load cell 49 via the detection cable 50. The detection cable 50 corresponds to an example of a "sensor cable." In the material testing machine 1, the terminal device 6 and the control unit 4 may be formed integrally.

[0025] The actuator 22 may be driven by another power transmission medium such as an electric actuator, etc. Therefore, the control unit 4 and the actuator 22 may be connected to each other not only by the hydraulic piping 30 but also by various wirings such as signal lines and power lines.

[0026] [1-1-2. Configuration of the detection cable] Fig. 2 is a side view seen from the front, schematically showing the relationship between the second holding part 40 and the relay cable 60. For ease of explanation, the relay cable 60 is shown by a two-dot chain line in Fig. 2. For ease of explanation, the second holding part 40 arranged at a position close to the right bridging member 20 within the movable range is shown by a solid line, and the second holding part 40 arranged at a position closer to the support body 14 than that position is shown by a dashed dot line in Fig. 2.

[0027] As shown in FIGS. 1 and 2 , the detection cable 50 connects the load cell 49 to the terminal device 6. The detection cable 50 is a signal line that transmits a signal from the load cell 49 to the terminal device 6. In the material testing machine 1 of this embodiment, an excitation voltage is applied to the load cell 49 via the detection cable 50.

[0028] The detection cable 50 may be inserted into a tubular or duct-shaped housing member. The housing member may be, for example, a conduit, a cable carrier, a Cableveyor (registered trademark), or the like that can bend freely together with the detection cable 50. The housing member may have enough rigidity to hold the detection cable 50 in a state spaced apart from the installation surface G.

[0029] The detection cable 50 includes a crosshead fixing cable 52 connected to the load cell 49, a ground fixing cable 54 connected to the terminal device 6, and a relay cable 60 connecting the crosshead fixing cable 52 and the ground fixing cable 54 to each other. The crosshead fixed cable 52 corresponds to an example of a "first fixed cable." The ground fixed cable 54 corresponds to an example of a "second fixed cable." The crosshead fixed cable 52 and the ground fixed cable 54 correspond to an example of a "fixed cable." The relay cable 60 corresponds to an example of a "detachable cable."

[0030] One end of the crosshead fixing cable 52 is connected to the load cell 49. The crosshead fixing cable 52 is routed from the load cell 49, for example, along the crosshead 42, and the other end extends to an end of a predetermined location on the second holding part 40. A connector 56 is provided at the other end of the crosshead fixing cable 52.

[0031] The crosshead fixing cable 52 is fixed to a predetermined location of the second holding part 40, for example, to the crosshead 42. The connector 56 is also fixed to a predetermined location of the second holding part 40. This allows the crosshead fixing cable 52 to move integrally with the second holding portion 40 when the second holding portion 40 moves.

[0032] The connector 56 in this embodiment is attached to the front end of the crosshead 42. As shown in Fig. 2, the connector 56 is disposed at a position spaced above the installation surface G. The connector 56 may be attached to the lower end of the crosshead 42 instead of the front end of the crosshead 42.

[0033] One end of the ground cable 54 is connected to the terminal device 6. The ground cable 54 is routed from the terminal device 6, for example, along the installation surface G, and the other end extends to a position close to the movement range of the second holding unit 40. A connector 58 is provided at the other end of the ground cable 54. As shown in FIG. 1 , the connector 58 is arranged in a position that overlaps with a line L1 that passes through the connector 56 in a plan view and is parallel to the movement direction of the second holding unit 40, in other words, the extension direction of the threaded rod 18.

[0034] The ground fixing cable 54 is fixed to the installation surface G. This makes it difficult for any part of the ground fixing cable 54 to bend or stretch even when the second holding part 40 moves.

[0035] The relay cable 60 has a longitudinal length dimension formed to correspond to the movable distance of the second holding portion 40. Specifically, the longitudinal length dimension of the relay cable 60 is formed according to the distance between the approach position P1 and the separated position P2. The relay cable 60 is provided at both ends with connectors 62 that can be connected to the connectors 56 and 58. The connectors 62 are formed to be detachable from the connectors 56 and 58, respectively.

[0036] The relay cable 60 is connected to the crosshead fixed cable 52 and the ground fixed cable 54 via the connectors 62. In this embodiment, one connector 62 of the relay cable 60 is connected from the right side to a connector 56 fixed to the crosshead 42. The other connector 62 of the relay cable 60 is connected from the right side to a connector 58 installed on the installation surface G. As a result, the relay cable 60 extends from the connector 62 to the right and is routed so as to descend toward the installation surface G, is bent toward the left, and then is routed so as to come into contact with the installation surface G.

[0037] In this embodiment, when the second holding part 40 moves to the separated position P2 where it is closest to the right bridging member 20, the relay cable 60 is arranged along the installation surface G in a state where it extends in a substantially straight line. In this case, the relay cable 60 extends along the threaded rod 18.

[0038] In this state, when the second holding part 40 moves in a direction approaching the first holding part 10, the crosshead fixing cable 52 side of the relay cable 60 is bent so as to rise from the installation surface G. Furthermore, when the second holding part 40 approaches the first holding part 10, it is bent in a substantially U-shape in a side view, and is bent in a state along the installation surface G.

[0039] When the second holding unit 40 moves to the approach position P1 where it is closest to the first holding unit 10, the connectors 58 and 56 are configured to overlap in a plan view. Therefore, in this embodiment, the connectors 58 and 56 can be positioned in the same position from the perspective of a worker working on the installation surface G, making it easier to replace the relay cable 60 compared to when the connectors 58 and 56 are positioned at different positions. In this embodiment, because the connectors 58 and 56 are arranged so as to be overlapping in a plan view, it is easy to use, for example, a flat cable 60 as the relay cable 60.

[0040] [1-2. Operation] Next, an example of the operation of the material testing machine 1 of this embodiment will be described. When conducting a test using the materials testing machine 1, for example, the operator moves the second holding part 40 to the approach position P1. Then, the operator holds the first end TP1 of the test piece TP in the first holding part body 26, and holds the second end TP2 in the second holding part body 48. Next, the operator moves the second holding part 40 so that the test piece TP extends linearly, and then fixes it in a predetermined position with the clamp 46.

[0041] Thereafter, the control unit 4 controls the direction and amount of pressure oil, and a force that moves the actuator 22 back and forth in the left and right direction acts on the actuator 22. As a result, a test force in the tensile direction is repeatedly applied to the test specimen TP held by the first holding part body 26 and the second holding part body 48. The test force is measured by the load cell 49, and a signal indicating the measurement result is transmitted to the terminal device 6 via the detection cable 50.

[0042] Here, when the second holding unit 40 is moved, the distance between the connector 56 of the crosshead fixing cable 52 and the connector 58 of the ground fixing cable 54 changes. Therefore, the bending shape of the relay cable 60 connected to the connector 56 of the crosshead fixing cable 52 and the connector 58 of the ground fixing cable 54 changes. That is, as shown in FIG. 2 , the relay cable 60 of the detection cable 50 moves while changing its bending state as the second holding unit 40 moves. For this reason, the relay cable 60 may deteriorate due to repeated bending and stretching.

[0043] In particular, the material testing machine 1 of this embodiment often has a horizontal size of about 10 to 20 meters, and the movement distance of the second holding part 40, i.e., the distance between the approach position P1 and the separation position P2, can be several meters. Therefore, in the case of such a size, the relay cable 60 is particularly susceptible to deterioration due to repeated bending and stretching with large changes.

[0044] In contrast, when the second holding unit 40 is moved, the distance (positional relationship) between the connector 56 of the crosshead fixing cable 52 and the load cell 49 does not change. In addition, the distance (positional relationship) between the connector 58 of the ground fixing cable 54 and the terminal device 6 does not change either. Therefore, even if the second holding unit 40 is moved, bending and stretching of the crosshead fixing cable 52 and the ground fixing cable 54 is suppressed.

[0045] The detection cable 50 of this embodiment is formed by a relay cable 60 that is detachable from the crosshead fixing cable 52 and the ground fixing cable 54, which are other parts that bend and stretch as the second holding part 40 moves. As a result, in the detection cable 50 of this embodiment, the parts that may break due to movement of the second holding part 40 can be secured to the relay cable 60, and the detection cable 50 can be easily repaired by replacing the relay cable 60. Therefore, in the materials testing machine 1, the replacement work of the detection cable 50 can be made easier than when the entire detection cable 50 is replaced, and the amount of cable required for replacement can be reduced.

[0046] The relay cable 60 is formed so that its longitudinal length is approximately the same as the movable distance of the second holding part 40, and when extended in a straight line, it extends approximately parallel to the linear movable range of the second holding part 40, connecting the crosshead fixing cable 52 and the ground fixing cable 54. This allows the portion of the detection cable 50 that may be cut when the second holding portion 40 moves to be kept within a shorter dimension.

[0047] The detection cable 50 is connected to the second holding part 40, which has a shorter moving distance and moves less frequently, out of the first holding part 10 and the second holding part 40 provided in the materials testing machine 1. This reduces the frequency with which the detection cable 50 is bent or stretched, and shortens the range over which the detection cable 50 is bent or stretched.

[0048] [Variations] The above-described embodiment is an example of one aspect of the present invention, and any modifications and applications are possible without departing from the spirit of the present invention.

[0049] In the above-described embodiment, the material testing machine 1 is a testing machine that applies a tensile load, but is not limited to this and may be a testing machine that applies other test forces, such as a compressive load.

[0050] In the above-described embodiment, the second holding part 40 is configured to be movable between the approach position P1 and the distance position P2, but this is not limiting. For example, the second holding part 40 may be configured to be movable toward the first holding part from the approach position P1. In this case, the relay cable 60 may be configured to be disposed in contact with the installation surface G in a state where it extends in a substantially straight line.

[0051] In addition, the material testing machine 1 may be configured so that the relay cable 60 is bent at a predetermined point and placed in contact with the installation surface G, depending on the structure of the testing machine main body 2 and the placement positions of the testing machine main body 2, control unit 4, and terminal device 6.

[0052] In the above-described embodiment, the detection cable 50 preferably includes the crosshead fixing cable 52, the ground fixing cable 54, and the relay cable 60, but is not limited to this. For example, the crosshead fixing cable 52 may be omitted, and the detection cable 50 may include only the ground fixing cable 54 and the relay cable 60, with the relay cable 60 being directly detachably attached to the load cell 49. Similarly, for example, the ground fixing cable 54 may be omitted, and the detection cable 50 may include only the crosshead fixing cable 52 and the relay cable 60, with the relay cable 60 being directly detachably attached to the terminal device 6.

[0053] Furthermore, for example, the detection cable 50 is not limited to one, and may include a plurality of relay cables 60. In this case, the crosshead fixing cable 52 and the ground fixing cable 54 are connected to each other via the plurality of relay cables 60.

[0054] In the above-described embodiment, the configuration of the load cell 49 has been described as a sensor, but the sensor that moves integrally with the second holding unit 40 is not limited to the load cell 49. For example, any sensor such as a temperature sensor or a stroke sensor when the second holding unit main body 48 moves relative to the second holding unit 40, or a sensor such as a temperature sensor, may be used.

[0055] In the above-described embodiment, the second holding portion 40 moves left and right along the threaded rod 18 via the ball screw nut portion 44, but this is not limited thereto, and the second holding portion 40 may be formed to be movable by various actuators such as pneumatic or electric actuators, or manually, etc.

[0056] In the above embodiment, a horizontal material testing machine 1 has been described, but the present invention may also be applied to a vertical type, that is, a configuration in which the crosshead 42 moves up and down.

[0057] Unless otherwise specified, the horizontal, vertical, and other directions and various shapes in the above-described embodiments include a so-called equivalent range that provides the same effects as those directions and shapes.

[0058] [Aspect] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0059] (Item 1) A materials testing machine according to one embodiment comprises a first holding part that holds a first end of a test piece, a second holding part that is supported so as to be movable toward and away from the first holding part and that holds a second end of the test piece, a sensor that moves integrally with the second holding part, a sensor cable extending from the sensor, and an information processing device to which the sensor cable is connected, wherein the sensor cable comprises a fixed cable and a detachable cable that is detachably connected to the fixed cable, and the detachable cable is flexible and may be positioned so that its degree of bending changes in accordance with the movement of the second holding part.

[0060] According to the material testing machine described in paragraph 1, since only the detachable cable, which changes its bending state, is susceptible to damage in the sensor cable, the sensor cable can be easily replaced by simply replacing the detachable cable. Therefore, it is possible to provide a material testing machine that makes the sensor cable replacement easier than if the entire sensor cable were replaced.

[0061] (Item 2) In the material testing machine described in item 1, the fixed cable may include a first fixed cable connected to the sensor and fixed to the second holding portion, and a second fixed cable connected to the information processing device and fixed, and the detachable cable may be detachably connected to each of the first fixed cable and the second fixed cable.

[0062] According to the material testing machine described in the second aspect, the detachable cable can be easily shortened, which facilitates the replacement of the detachable cable and also makes it easier to prevent unnecessary replacement of cable components.

[0063] (Item 3) In the material testing machine described in item 2, the detachable cable may extend from the second fixed cable along the movement direction of the second holding part.

[0064] According to the material testing machine described in paragraph 3, the detachable cable is likely to bend in the direction of movement of the second holding part, so it is easy to identify the bending position of the detachable cable, making it easier to shorten the detachable cable, facilitating the replacement work of the detachable cable, and making it easier to reduce the need to replace unnecessary cable parts.

[0065] (Item 4) In the material testing machine described in item 3, the second holding part may be supported so as to be movable between a close position close to the first holding part and a separated position separated from the first holding part, and the second fixed cable and the detachable cable may be connected at a position corresponding to the close position.

[0066] Furthermore, according to the material testing machine described in item 4, it is easy to identify the bending position of the detachable cable, and as a result, it is easy to shorten the detachable cable.

[0067] (Item 5) In the material testing machine according to any one of items 1 to 4, the sensor may be a load cell capable of detecting a force applied to the test piece.

[0068] According to the material testing machine described in paragraph 5, the sensor cable of the load cell can be easily replaced. [Explanation of symbols]

[0069] 1. Material testing machine 6. Terminal equipment (information processing equipment) 10 1st holding part 40 Second holding part 49 Load cell (sensor) 50 Detection cable (sensor cable) 52 Crosshead fixed cable (first fixed cable, fixed cable) 54 Ground fixed cable (second fixed cable, fixed cable) 60 Relay cable (detachable cable) P1 approach position P2 Separate position TP test specimen TP1 1st end TP2 2nd end

Claims

1. a first holding portion that holds a first end portion of the test specimen; a second holding portion supported so as to be movable toward and away from the first holding portion and configured to hold a second end portion of the test piece; a sensor that moves integrally with the second holding portion; a sensor cable extending from the sensor; an information processing device to which the sensor cable is connected; A material testing machine comprising: The sensor cable A fixed cable and a detachable cable that is detachably connected to the fixed cable; Equipped with The detachable cable is flexible and is provided at a position where the degree of bending changes in response to the movement of the second holding portion. Material testing machine.

2. The fixed cable is a first fixed cable connected to the sensor and fixed to the second holding portion; a second fixed cable connected to and fixed on the information processing device; Equipped with The detachable cable is detachably connected to each of the first fixed cable and the second fixed cable.

2. The material testing machine according to claim 1.

3. The detachable cable extends from the second fixed cable along the movement direction of the second holding part.

3. A material testing machine according to claim 2.

4. The second holding portion is an approach position in which the first holding portion is approached; a spaced position spaced from the first holding portion; and supported so as to be movable between The second fixed cable and the detachable cable are connected at a position corresponding to the approach position.

4. A material testing machine according to claim 3.

5. The sensor is a load cell capable of detecting a force applied to the test piece.

5. A material testing machine according to claim 1.

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