Material testing machine

Abstract

To provide a material testing machine capable of easily preventing foreign matters from entering a gripping tool driven by driving force at the time of a test during specimen setup while ensuring a work space during specimen setup.SOLUTION: A material testing machine (1) comprises: gripping tools (18, 19) that grip a specimen (T); a drive member (36) that drives the gripping tools (18, 19) to generate gripping force in the gripping tools (18, 19); operation members (80, 90) that output commands to drive the drive member (36); and a control device (100) that controls the drive member (36) based on commands from the operation members (80, 90). The operation members (80, 90) include a pair of operation parts (85, 87, 95, 97) operable with both hands, and output a command to set the driving force of the drive member (36) to the driving force suitable for a test when the pair of operation parts (85, 87, 95, 97) are operated.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] Conventionally, there is known a hydraulic material testing machine that is configured so that a chuck mechanism for gripping a test piece can be driven by switching between low pressure and high pressure (see, for example, Patent Document 1). In the material testing machine described in Patent Document 1, a door is provided in front of the chuck mechanism, and by detecting whether the door is open or closed, the chuck mechanism is driven at low pressure when the door is open, and at high pressure when the door is closed. This prevents an operator from touching the chuck mechanism that is driven at high pressure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Jpn. Jpn. Published No. 62-6506 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 requires opening and closing a door, which can easily get in the way depending on the size of the specimen, making it difficult to set the specimen on the gripper. Also, when the test is being carried out, the operator issues commands from a PC or operation panel that is separate from the main body of the testing machine, so there is little risk of foreign objects getting caught in the main body of the testing machine, whereas when setting the specimen on the gripper, which is the preparation process, the operator often works close to the testing machine, unlike in the main process such as test execution, so it is inconvenient to control the drive of the preparation process from a PC. The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a materials testing machine that can easily prevent foreign matter from getting into the gripping tools that are driven by the driving force during testing when the specimen is set, while ensuring working space when the specimen is set.

Means for Solving the Problems

[0005] An aspect of the present invention is a material testing machine including a gripper for gripping a specimen, a drive member for driving the gripper to generate a gripping force in the gripper, an operation member for outputting a command for driving the drive member, and a control device for controlling the drive member according to the command of the operation member, wherein the operation member includes a set of operation parts that can be operated with both hands, and when the set of operation parts is operated, a command for making the driving force of the drive member a driving force suitable for testing is output.

Effects of the Invention

[0006] According to an aspect of the present invention, based on the command of a set of operation parts that can be operated with both hands, which was used in the main process of a conventional device such as a press working machine, the safety at the time of setting a specimen in the gripper, which is a preparation process of the testing machine, is improved. Also, it is easy to make the structure compact and easy to secure a working space at the time of setting the specimen. Further, since the set of operation parts is likely to be inoperable when both hands are not free at the time of setting the specimen, it is easy to prevent the gripper from operating with the gripping force at the time of testing when the operator's hand is near the gripper at the time of setting. Therefore, it is easy to prevent foreign matter from entering the gripper that is driven by the driving force at the time of testing at the time of setting the specimen while securing a working space at the time of setting the specimen.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for carrying out the invention

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0009] [1. First Embodiment] FIG. 1 is a view of a material testing machine 1 according to the first embodiment. The material testing machine 1 according to the embodiment is a material testing machine capable of applying a test load in a tensile direction, which is a direction in which the distance between the upper and lower grippers 18 and 19 widens, to a specimen T gripped at both ends by the upper and lower grippers 18 and 19.

[0010] The material testing machine 1 of the present embodiment includes a testing machine main body 10 that applies a test load to the specimen T, and a control device 100 that controls the testing machine main body 10 and the like.

[0011] The testing machine main body 10 has a base 11 installed on the floor surface. On the base 11, a ram cylinder 12 is arranged. The ram cylinder 12 has a ram 12a configured to be able to move up and down by hydraulic pressure. A hydraulic source is connected to the ram cylinder 12. The hydraulic pressure in the ram cylinder 12 is measured by a pressure cell (not shown) and input to the control device 100. A rectangular plate-shaped table 13 is fixed to the upper end of the ram 12a. The table 13 can move up and down by the ram cylinder 12.

[0012] On the table 13, a pair of columns 14 are arranged in the first diagonal direction. The upper part of the pair of columns 14 is supported in a state where an upper crosshead 15 extending in the width direction is bridged. The pair of columns 14 and the upper crosshead 15 move up and down integrally with the table 13.

[0013] In Table 13, a pair of through holes (not shown) penetrating in the thickness direction are formed in the second diagonal direction. Threaded rods 16 extending in the vertical direction are inserted into these through holes respectively. The threaded rods 16 are erected on the base 11 below the table 13. A lower cross head 17 extending in the width direction is spanned over the threaded rods 16 above the table 13. The lower cross head 17 is supported by the threaded rods 16 via nuts (not shown). When this nut is rotated by a drive source (not shown), the lower cross head 17 moves up and down along the threaded rods 16. Thereby, the height of the lower cross head 17 is set.

[0014] Grippers 18 and 19 for gripping the specimen T are provided on the upper cross head 15 and the lower cross head 17 respectively. When the lower cross head 17 is set to a predetermined height and both ends of the specimen T are gripped by the gripper 18 of the upper cross head 15 and the gripper 19 of the lower cross head 17. In this state, by moving the table 13 upward, the upper cross head 15 rises with respect to the lower cross head 17, and a tensile load is applied to the specimen T. As the specimen T, specimens of various shapes and sizes can be adopted. For example, test pieces, steel bars, deformed steel bars, etc. are used.

[0015] In the testing machine main body 1 according to the present embodiment, an upper platen 20 is provided on the lower surface of the lower cross head 17, and a lower platen 21 is provided on the upper surface of the table 13. Between the upper platen 20 and the lower platen 21, a specimen T such as concrete is sandwiched, and by moving the table 13 upward, a load in the compression direction can be applied to the specimen T.

[0016] FIG. 2 is a view showing the upper gripper 18 of the material testing machine 1 according to the first embodiment. On the upper crosshead 15, a chuck frame portion 31 is formed. The chuck frame portion 31 has a shape in which the interior forms a space whose width in the width direction becomes narrower as it goes toward the lower gripper 19 side. On the inner surface in the width direction of the chuck frame portion 31 forming this space, a pair of inclined guides 32 are attached in the width direction such that the interval in the width direction becomes narrower as it goes toward the lower end side.

[0017] In the width direction of the material testing machine 1, wedge-shaped gripping teeth 33 are arranged on the inner surface of the inclined guide 32. On the inner surface of the gripping teeth 33, a gripping tooth main body portion 33a is provided. The gripping tooth main body portion 33a bites into the specimen T. The gripping teeth 33 are provided slidably along the inner surface of the inclined guide 32. The gripping teeth 33 are supported at the upper part by a rail guide 34. The rail guide 34 is slidably supported by a rail 35 extending in the width direction. Thereby, the gripping teeth 33 can slide in the width direction along the rail 35. The rail 35 is connected to the piston rod 38 of a hydraulic cylinder (driving member) 36. The hydraulic cylinder 36 has a casing 37 and a piston rod 38 supported so as to be able to advance and retreat with respect to the casing 37. The casing 37 is fixed to the upper crosshead 15. Pressure oil is supplied to the casing 37 via a hydraulic circuit 40 (see FIG. 3).

[0018] When the piston rod 38 rises, an upward moving force acts on the gripping teeth 33 via the rail 35 and the rail guide 34. Therefore, the gripping teeth 33 move obliquely upward along the inclined guide 32. Accordingly, the interval between the pair of gripping teeth 33 in the width direction widens, and the gripping teeth 33 are in an open state. Also, when the piston rod 38 descends, a downward moving force acts on the gripping teeth 33 via the rail 35 and the rail guide 34. Therefore, the gripping teeth 33 move obliquely downward along the inclined guide 32. Accordingly, the interval between the pair of gripping teeth 33 in the width direction narrows, and the gripping teeth 33 can close to grip the specimen T.

[0019] The lower gripper 19 is provided on the lower crosshead 17. The lower gripper 19 is configured in the same manner as the upper gripper 18, except that it is provided on the lower crosshead 17 and is configured upside down with respect to the upper gripper 18.

[0020] FIG. 3 is a diagram showing the hydraulic circuit 40 of the material testing machine 1 according to the first embodiment. The hydraulic circuit 40 includes a feed pipe 52 that sends oil from the hydraulic tank 51 to the entire hydraulic circuit 40, and a return pipe 53 that returns the oil to the hydraulic tank 51. A hydraulic pump 55 driven by an electric motor 54 is arranged in the middle of the feed pipe 52, and a check valve 56 is provided on the discharge side of the hydraulic pump 55. An upper circuit portion 41 and a lower circuit portion 42 are connected in parallel to the feed pipe 52 and the return pipe 53. The upper circuit portion 41 supplies pressure oil to the hydraulic cylinder 36 of the upper gripper 18. The lower circuit portion 42 supplies pressure oil to the hydraulic cylinder 36 of the lower gripper 19.

[0021] The upper circuit portion 41 includes a relief valve 61, a throttle valve 62, an electromagnetic switching valve 63, a high-pressure circuit portion 64, a low-pressure circuit portion 65, a first circuit element 66, a second circuit element 67, and the hydraulic cylinder 36 of the upper gripper 18. The first circuit element 66 and the second circuit element 67 are, for example, an electromagnetic servo valve that changes the flow rate of the pressure oil supplied to the hydraulic cylinder 36, and an electromagnetic stop valve that shuts off and communicates the pressure oil from the electromagnetic servo valve to the hydraulic cylinder 36.

[0022] The high-pressure circuit portion 64 and the low-pressure circuit portion 65 are connected in parallel. The high-pressure circuit section 64 includes a direction switching valve 71 and a check valve 72. The high-pressure circuit section 64 supplies the hydraulic pressure set by the relief valve 61, as it is, to the hydraulic cylinder 36 via the first circuit element 66 and the second circuit element 67. The pressure set by the relief valve 61 is a pressure that makes the driving force of the hydraulic cylinder 36 a driving force suitable for the test, that is, a driving force during the test. Specifically, the pressure set by the relief valve 61 is a pressure that causes the gripping teeth 33 driven by the hydraulic cylinder 36 to generate a gripping force on the gripping teeth 33 such that the gripping teeth 33 bite into the metal test specimen T. During the test execution, a large test force is applied to the test specimen T, and the gripping teeth 33 of the grippers 18 and 19 need to continue gripping the test specimen T even during the test. In the present embodiment, by switching the pressure of the hydraulic cylinder 36, a clamping force suitable for the test is provided to the gripping teeth 33 of the grippers 18 and 19.

[0023] The low-pressure circuit section 65 includes a pressure reducing valve 73 and a direction switching valve 74. In the low-pressure circuit section 65, the hydraulic pressure set by the relief valve 61 is reduced by the pressure reducing valve 73. Therefore, the low-pressure circuit section 65 supplies the reduced pressure oil to the hydraulic cylinder 36 via the first circuit element 66 and the second circuit element 67. The pressure reduced by the pressure reducing valve 73 is a pressure suitable for setting the test specimen T, that is, a pressure that causes the gripping teeth 33 driven by the hydraulic cylinder 36 to generate a small gripping force on the gripping teeth 33 such that the gripping teeth 33 can grip and hold the metal test specimen T.

[0024] Generally, the hydraulic pump 55 used in the hydraulic circuit 40 of the material testing machine 1 is optimized for testing. That is, it is a hydraulic pump 55 that generates a gripping force on the grippers 18 and 19 so that the specimen T does not slip off the grippers 18 and 19 even during the test when a test load is applied to the specimen T. However, when setting the specimen T on the grippers 18 and 19, that is, when no test load is applied to the specimen T, a gripping force that is about one to two orders of magnitude smaller than the gripping force during the test is sufficient. At this time, since the hydraulic pump 55 is optimized for the purpose of use, it is difficult to accurately reduce the hydraulic pressure only by controlling the output of the hydraulic pump 55. On the other hand, in this embodiment, since the low-pressure circuit section 65 is provided, the hydraulic pressure can be accurately reduced and supplied to the hydraulic cylinder 36.

[0025] The lower circuit section 42 corresponds to a hydraulic circuit composed only of the high-pressure circuit of the upper circuit section 41. That is, the lower circuit section 42 is equivalent to a hydraulic circuit in which the low-pressure circuit section 65 is omitted from the upper circuit section 41. The lower circuit section 42 supplies pressure oil to the hydraulic cylinder 36 of the lower gripper 19. In FIG. 3, only a part of the lower circuit section 42 is illustrated.

[0026] FIG. 4 is an enlarged view of the main part of FIG. 1. In the hydraulic circuit 40, pressure oil is supplied to the hydraulic cylinder 36 when the operating members 80 and 90 are operated. In this embodiment, it includes an upper operating member 80 that outputs a command for supplying pressure oil to the hydraulic cylinder 36 of the upper gripper 18, and a lower operating member 90 that outputs a command for supplying pressure oil to the hydraulic cylinder 36 of the lower gripper 19.

[0027] The upper operating member 80 is provided adjacent to the upper gripper 18. In this embodiment, the upper operating member 80 is provided on the upper crosshead 15. The upper operating member 80 has a set of a first switch box 81 and a second switch box 82.

[0028] The first switch box 81 is provided on the first side in the width direction of the upper gripper 18. The first switch box 81 has a power switch 83, a low-voltage button (one-handed operation part) 84, a first high-voltage button (first operation part, operation part) 85, and an open button 86. The power switch 83 is an alternate type switch. That is, in the power switch 83, when the switch is switched, the state of the switch is maintained even if the operator releases the hand. The buttons 84 to 86 are momentary type switches. That is, the buttons 84 to 86 are switches that return to the original state when the operator releases the hand even if the switch is switched.

[0029] The second switch box 82 is provided on the second side in the width direction of the upper gripper 18. The second switch box 82 has a second high-voltage button (second operation part, operation part) 87. The second high-voltage button 87 is a momentary type switch.

[0030] The lower operation member 90 is provided adjacent to the lower gripper 19. In the present embodiment, the lower operation member 90 is provided on the lower crosshead 17. The lower operation member 90 has a set of a first switch box 91 and a second switch box 92.

[0031] The first switch box 91 is provided on the first side in the width direction of the lower gripper 19. The first switch box 91 has a power switch 93, a first high-voltage button (first operation part, operation part) 95, and an open button 96. That is, in the lower first switch box 91, there is no low-voltage button switch. The power switch 93 is an alternate type switch. The buttons 95 to 96 are momentary type switches.

[0032] The second switch box 92 is provided on the second side in the width direction of the lower gripper 19. The second switch box 92 has a second high-voltage button (second operation part, operation part) 97. The second high-voltage button 97 is a momentary type switch.

[0033] In the operation members 80 and 90, the power switches 83 and 93, the low-pressure buttons 84, the release buttons 86 and 96 of the first switch boxes 81 and 91 output commands when operated individually. On the other hand, the first high-pressure buttons 85 and 95 output commands when the corresponding second high-pressure buttons 87 and 97 are also pressed. That is, in the upper operation member 80, when the first high-pressure button 85 and the second high-pressure button 87 are simultaneously pressed, a command to supply high-pressure hydraulic oil to the hydraulic cylinder 36 of the upper gripper 18 is output. Also, in the lower operation member 90, when the first high-pressure button 95 and the second high-pressure button 97 are simultaneously pressed, a command to supply high-pressure hydraulic oil to the hydraulic cylinder 36 of the lower gripper 19 is output. Generally, when setting the specimen T in the grippers 18 and 19, the specimen T is often set from the upper gripper 18 in view of the influence of gravity. At this time, the upper gripper 18 requires at least a pressure (i.e., low pressure) sufficient to hold the specimen T. In this embodiment, the operator can perform the low-pressure operation with the remaining hand while holding the specimen T in one hand. On the other hand, since the operator is holding the specimen T in one hand, the operator cannot press the set of high-pressure buttons 85 and 87. In other words, the high-pressure operation cannot be executed during the low-pressure setting.

[0034] Here, when the first high-pressure buttons 85, 95 and the second high-pressure buttons 87, 97 are pressed simultaneously, for example, in the upper operation member 80, after one of the high-pressure buttons 85, 87 of either the first switch box 81 or the second switch box 82 is pressed, within a predetermined time, the other high-pressure button 87, 85 of the first switch box 81 and the second switch box 82 is also pressed. Also, in the lower operation member 90, after one of the high-pressure buttons 95, 97 of either the first switch box 91 or the second switch box 92 is pressed, within a predetermined time, the other high-pressure button 97, 95 of the first switch box 91 and the second switch box 92 is also pressed. Note that the aspect of the present invention is not limited to the configuration of this embodiment. For example, the first high-pressure button 85, which is one of a set of high-pressure buttons, may also serve as a low-pressure button. At this time, the low-pressure button 84 may be omitted. In this case, when only the first high-pressure button 85, which also serves as a low-pressure button (one-handed operation part), is pressed, the hydraulic cylinder 36 of the upper gripper 18 has a low hydraulic pressure, and by simultaneously pressing the first high-pressure button 85 and the second high-pressure button 87, it may be switched from low-pressure to high-pressure hydraulic pressure. Note that instead of the first high-pressure button 85, the second high-pressure button 87 may also serve as a low-pressure button, or both the first high-pressure button 85 and the second high-pressure button 87 may each serve as a low-pressure button.

[0035] As a result, unless the first switch boxes 81, 91 and the second switch boxes 82, 92 are operated within a predetermined time, the operation members 80, 90 do not output a command. Therefore, for example, after performing an operation of pressing one of the high-pressure buttons with a tape or the like, it is possible to prevent the button operation from being accepted even if the remaining high-pressure button is pressed.

[0036] As shown in FIG. 1, a control device 100 for controlling each part of the material testing machine 1 is arranged in the material testing machine 1. The control device 100 is connected to be able to transmit and receive signals to and from the material testing machine 1. The signals received by the control device 100 are appropriate signals required for control and testing, such as command signals output by the operation members 80 and 90, and measurement signals output by a load cell (not shown). The signals transmitted by the control device 100 are control signals for each part of the hydraulic circuit 40 such as the electric motor 54 of the hydraulic pump 55 and the electromagnetic switching valve 63, control signals for the motor of the nut (not shown) of the lower crosshead 17, and other appropriate signals required for control and testing.

[0037] The control device 100 includes a computer, and this computer includes a processor such as a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit), a memory device such as a ROM (Read Only Memory) or a RAM (Random Access Memory), a storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive), and an interface circuit for connecting the control device 100 and various peripheral devices. Then, by the processor executing the control program stored in the memory device or the storage device, various functions of the material testing machine 1 are realized.

[0038] In the present embodiment, the control device 100 controls the hydraulic cylinder 36 by controlling each part of the hydraulic circuit 40 according to the commands of the operation members 80 and 90. Thereby, the upper grippers 18 and 19 are operated.

[0039] Next, the operation of the present embodiment will be described. By turning on the power switches 83 and 93 of the operation members 80 and 90 from OFF to ON, the operation members 80 and 90 are energized, and commands from the operation members 80 and 90 are output to the control device 100. The control device 100 controls each part of the hydraulic circuit 40 according to the commands of the operation members 80 and 90. Thereby, the pressure oil of the hydraulic circuit 40 can be supplied to the hydraulic cylinders 36 of the grippers 18 and 19, and the gripping teeth 33 can be opened and closed.

[0040] When the operator starts the test, after turning on the power switch 83 of the upper operation member 80, the test specimen T is set on the material testing machine 1. Specifically, the operator holds the test specimen T and places it between the pair of gripping teeth 33 of the upper gripper 18, and then presses the low-pressure button 84 of the upper operation member 80. When the low-pressure button 84 is pressed, a low-pressure start command is input to the control device 100, each part of the hydraulic circuit 40 is controlled, and low-pressure hydraulic pressure is supplied to the hydraulic cylinder 36 of the upper gripper 18 through the low-pressure circuit part 65. Therefore, the gripping force of the gripping teeth 33 operates in a state where it is smaller than that during the test, and the test specimen T is gripped by the upper gripper 18. That is, the test specimen T is set on the upper gripper 18. At this time, for example, by adjusting the lower end of the test specimen T, the positional deviation from between the pair of gripping teeth 33 of the lower gripper 19 can be suppressed.

[0041] When the gripping teeth 33 grip the test specimen T, the operator can release his hand from the test specimen T. That is, both hands of the operator are free. For this reason, it becomes possible to press the first high-pressure button 85 of the first switch box 81 with the right hand and the second high-pressure button 87 of the second switch box 82 with the left hand. Therefore, by pressing both the first high-pressure button 85 and the second high-pressure button 87 with both hands, a high-pressure start command is input to the control device 100, each part of the hydraulic circuit 40 is controlled, and high-pressure pressure oil is supplied to the hydraulic cylinder 36 of the upper gripper 18 through the high-pressure circuit part 64. Therefore, the gripping force of the gripping teeth 33 becomes the gripping force during the test, and the test specimen T is firmly gripped by the upper gripper 18.

[0042] Next, the lower gripper 19 is actuated. Thus, the lower operating member 90 is operated. The operator switches the power switch 93 from OFF to ON. Then, by pressing both hands on a set of a first high-pressure button 95 and a second high-pressure button 97, a command for starting high pressure is input to the control device 100, each part of the hydraulic circuit 40 is controlled, and high-pressure pressure oil is supplied to the hydraulic cylinder 36 of the lower gripper 19 via the high-pressure circuit section 64. Thus, the gripping force of the gripping teeth 33 becomes the gripping force during the test, and the test specimen T is firmly gripped by the lower gripper 19. Since the test specimen T is firmly gripped by the upper gripper 18 and then firmly gripped by the lower gripper 19, it is easy to absorb the positional deviation of the test specimen T.

[0043] After the test specimen T is firmly gripped by the grippers 18 and 19, the test is started. That is, the ram cylinder 12 is actuated, and a tensile load is applied to the test specimen T. Then, when the test specimen T is broken, the test ends.

[0044] When the test ends, the operator, for example, presses the release button 86 of the upper operating member 80 while gripping the broken upper test specimen T. Thereby, the gripping teeth 33 of the upper gripper 18 are released, and the broken upper test specimen T can be recovered. Also, while gripping the broken lower test specimen T, the operator presses the release button 96 of the lower operating member 90. Thereby, the gripping teeth 33 of the lower gripper 19 are released, and the broken lower test specimen T can be recovered.

[0045] In this embodiment, as described above, in order to use the hydraulic cylinder 36 as the driving force during the test according to the commands of a set of high-pressure buttons 85, 87, 95, and 97 that can be operated with both hands, it is easy to achieve a compact configuration, and it is easier to secure the working space when setting the specimen T compared to the case where a protective door is provided. Also, when setting the specimen T with both hands not free, it is easy for the set of high-pressure buttons 85, 87, 95, and 97 to become inoperable. Therefore, when the operator's hands are around the grippers 18 and 19 during setting, it is easy to prevent the grippers 18 and 19 from operating with the gripping force during the test. Thus, while securing the working space when setting the specimen T, it is easy to prevent foreign objects, for example, foreign objects caused by the operator, from mixing into the grippers 18 and 19 that are driven by the driving force during the test when setting the specimen T.

[0046] [2. Second Embodiment] Next, the second embodiment will be described. Note that the same components as those in the first embodiment described above may be denoted by the same reference numerals and their description may be omitted.

[0047] FIG. 5 is a diagram showing the hydraulic circuit 240 of the material testing machine 1 according to the second embodiment. In the hydraulic circuit 240 according to the second embodiment, the low-pressure circuit portion 265 of the upper circuit portion 241 is different from the low-pressure circuit portion 65 of the first embodiment. That is, the low-pressure circuit portion 265 of the second embodiment is different in that it has a relief valve 273 instead of the pressure reducing valve 73. The relief valve 273 is set so that the hydraulic pressure in the low-pressure circuit portion 65 becomes a pressure that causes the gripping teeth 33 driven by the hydraulic cylinder 36 to generate a gripping force small enough to grip and hold the metal specimen T.

[0048] Also in the hydraulic circuit 240 of the second embodiment, high-pressure hydraulic oil can be supplied to the hydraulic cylinder 36 of the upper gripper 18 via the high-pressure circuit section 64, and low-pressure hydraulic oil can be supplied via the low-pressure circuit section 265. Therefore, also in the second embodiment, the hydraulic pressure supplied to the hydraulic cylinder 36 can be switched by operating the operation members 80 and 90. Accordingly, by means of the operation members 80 and 90, it is possible to easily prevent foreign matter from entering the grippers 18 and 19 that are driven by the driving force during the test when setting the specimen T while securing the working space at the time of setting the specimen T.

[0049] [3. Third Embodiment] Next, the third embodiment will be described. Note that the same components as those in the first or second embodiment described above may be denoted by the same reference numerals and their description may be omitted.

[0050] FIG. 6 is a diagram showing a hydraulic circuit 340 of the material testing machine 1 according to the third embodiment. In the hydraulic circuits 40 and 240 according to the first or second embodiment, the configuration has one hydraulic pump 55, but the hydraulic circuit 340 according to the third embodiment has two hydraulic pumps 55 and 355. That is, in the hydraulic circuit 340 according to the third embodiment, the low-pressure circuit section 365 and the high-pressure circuit section 364 are independently configured.

[0051] The high-pressure circuit section 364 according to the third embodiment includes, in addition to the direction switching valve 71 and the check valve 72, a feed pipe 52, a return pipe 53, a hydraulic pump 55 driven by an electric motor 54, a check valve 56, two relief valves 61, a throttle valve 62, and an electromagnetic switching valve 63.

[0052] The low-pressure circuit section 365 according to the third embodiment includes, in addition to the pressure reducing valve 73 and the direction switching valve 74, a feed pipe 352, a return pipe 353, a hydraulic pump 355 driven by an electric motor 354, a check valve 356, two relief valves 361, a throttle valve 362, and an upper electromagnetic switching valve 363. Here, it is desirable to use a pump with a smaller output for the hydraulic pump 355 than the hydraulic pump 55, but the hydraulic pump 355 may be the same pump as the hydraulic pump 55.

[0053] The high-pressure circuit section 364 and the low-pressure circuit section 365 are connected to the hydraulic cylinder 36 in parallel via the first circuit element 66 and the second circuit element 67. Note that a lower circuit section (not shown) is connected to the high-pressure circuit section 364 in parallel.

[0054] Also in the hydraulic circuit 340 of the third embodiment, high-pressure pressure oil can be supplied to the hydraulic cylinder 36 of the upper gripper 18 via the high-pressure circuit section 364, and low-pressure pressure oil can be supplied via the low-pressure circuit section 365. Therefore, also in the third embodiment, the hydraulic pressure supplied to the hydraulic cylinder 36 can be switched by operating the operation members 80 and 90. Accordingly, it is possible to easily prevent foreign matter from entering the grippers 18 and 19 that are driven by the driving force during the test when setting the specimen T while securing the working space at the time of setting the specimen T by the operation members 80 and 90.

[0055] [4. Modification Example] The above-described embodiments merely illustrate one aspect of the present invention, and arbitrary modifications and applications are possible without departing from the spirit of the present invention.

[0056] In the above-described embodiments, it is preferable to apply the gripping teeth 33 to the material testing machine 1 that operates hydraulically, but it may also be applied to a material testing machine in which the gripping teeth 33 are driven by an electric motor or an air cylinder.

[0057] In the above-described embodiments, the circuit board in the operation members 80 and 90 determines whether or not the first high-pressure buttons 85 and 95 and the second high-pressure buttons 87 and 97 are pressed simultaneously, but it may be configured such that the control device 100 determines.

[0058] In the above-described embodiments, the configuration in which the first high-pressure buttons 85 and 95 are arranged on the first side in the width direction with respect to the gripping teeth 33 and the second high-pressure buttons 87 and 97 are provided on the second side in the width direction has been described, but the reverse may also be possible. Further, although it is desirable to be provided on both sides in the width direction of the gripping teeth 33, the first high-pressure buttons 85 and 95 and the second high-pressure buttons 87 and 97 may be arranged on the same side in the width direction.

[0059] [5. Aspect] It is understood by those skilled in the art that the above-described exemplary embodiments and modification examples are specific examples of the following aspects.

[0060] (Item 1) A material testing machine according to one aspect includes a gripper for gripping a specimen, a drive member for driving the gripper to generate a gripping force in the gripper, an operation member for outputting a command for driving the drive member, and a control device for controlling the drive member according to the command of the operation member. The operation member includes a set of operation parts that can be operated with both hands, and when the set of operation parts is operated, a command for setting the driving force of the drive member to a driving force suitable for the test may be output.

[0061] According to the material testing machine described in Item 1, based on the commands of a set of operation parts that can be operated with both hands, which were used in the main process of conventional devices such as press working machines, the safety during the setting of the specimen to the gripper, which is a preparation process of the testing machine, is improved. Also, it is easy to make the configuration compact and easy to secure a working space during the setting of the specimen. Further, since it is easy for the set of operation parts to become inoperable when setting a specimen with both hands occupied, it is easy to prevent the gripper from operating with the gripping force during the test when the operator's hand is around the gripper during setting. Therefore, while securing a working space during the setting of the specimen, it is easy to prevent foreign matter from entering the gripper that is driven by the driving force during the test during the setting of the specimen.

[0062] (Item 2) In the material testing machine according to the first aspect, the operation member includes a single-handed operation part that can be operated with one hand, and when the single-handed operation part is operated, a command may be output to make the driving force of the driving member a driving force smaller than the driving force suitable for the test and suitable for setting the specimen.

[0063] According to the material testing machine described in the second aspect, while holding the specimen with one hand, by operating the single-handed operation part with the remaining one hand, a low-pressure operation suitable for setting the specimen can be performed, and the operator can set the specimen on the gripper.

[0064] (Item 3) In the material testing machine according to the second aspect, at least one of the pair of operation parts may also serve as the single-handed operation part.

[0065] According to the material testing machine described in the third aspect, for a pair of operation parts, by operating one that also serves as the single-handed operation part with one hand, a low-pressure operation suitable for setting the specimen can be performed, and by operating both of the pair of operation parts with both hands, a high-pressure operation suitable for the test can be performed. Also, since the single-handed operation part can be used in combination with the pair of operation parts, the number of physical parts that the operator needs to operate can be reduced.

[0066] (Item 4) The material testing machine according to any one of the first to third aspects may include a pair of upper and lower grippers and a pair of operation members provided corresponding to each of the pair of upper and lower grippers.

[0067] According to the material testing machine described in the fourth aspect, since there are an operation member for the upper gripper and an operation member for the lower gripper, the upper gripper and the lower gripper can be operated at different timings, and it is easier to absorb the positional deviation of the specimen gripped between the upper and lower grippers compared to the case where the upper and lower grippers grip the specimen simultaneously.

[0068] (Item 5) In the material testing machine according to claim 4, the pair of operation members may include an upper operation member provided adjacent to the upper gripper and a lower operation member provided adjacent to the lower gripper.

[0069] According to the material testing machine described in claim 5, even if there are a plurality of operation parts, it is possible to make it easier for an operator to recognize the operation part for operating the gripper.

[0070] (Claim 6) In the material testing machine according to any one of claims 1 to 5, the gripper includes a pair of gripping teeth for gripping a specimen, the operation member may include a first operation part on a first side in the width direction of the pair of gripping teeth, and a second operation part on a second side in the width direction of the pair of gripping teeth.

[0071] According to the material testing machine described in claim 6, a set of operation parts can be arranged at a position where they cannot be operated with one hand, and one-handed operation of the set of operation parts can be prevented.

[0072] (Claim 7) In the material testing machine according to any one of claims 1 to 6, the drive member is a hydraulic cylinder, and the hydraulic circuit connected to the hydraulic cylinder is configured to be able to supply hydraulic oil to the hydraulic cylinder by switching between high-pressure hydraulic oil for driving the hydraulic cylinder with a driving force suitable for the test and low-pressure hydraulic oil having a lower pressure than the high pressure for driving the hydraulic cylinder with a driving force suitable for setting the specimen.

[0073] According to the material testing machine described in claim 7, the gripper driven by a hydraulic cylinder is particularly likely to have a large gripping force during the test suitable for the test, but it can be preferably easily prevented that the gripper operates with the gripping force during the test when the operator's hand is around the gripper during setting.

Description of reference numerals

[0074] 1 Material testing machine 18 Gripper 19 Gripper 36 Hydraulic cylinder (drive member) 33 Gripping teeth 40 Hydraulic circuit 80 Operating member 84 Low-pressure button (single-handed operation part) 85 First high-pressure button (first operation part, operation part, single-handed operation part)) 87 Second high-pressure button (second operation part, operation part) 90 Operating member 95 First high-pressure button (first operation part, operation part) 97 Second high-pressure button (second operation part, operation part) 100 Control device 240 Hydraulic circuit 340 Hydraulic circuit T Specimen

Claims

1. A material testing machine comprising a gripping tool for gripping a specimen, a drive member for driving the gripping tool to generate a gripping force in the gripping tool, an operating member for outputting a command to drive the drive member, and a control device for controlling the drive member according to the command of the operating member, wherein the operating member includes a pair of operating parts that can be operated with both hands, and when the pair of operating parts are operated, a command is output to make the driving force of the drive member a driving force suitable for the test. Material testing machine.

2. The operating member includes a single-handed operating part that can be operated with one hand, and when the single-handed operating part is operated, a command is output to make the driving force of the drive member a driving force smaller than the driving force suitable for the test and suitable for setting the specimen. The material testing machine according to claim 1.

3. At least one of the pair of operating parts also serves as the single-handed operating part. The material testing machine according to claim 2.

4. A pair of upper and lower gripping tools, and a pair of the operating members provided corresponding to each of the pair of upper and lower gripping tools. The material testing machine according to claim 1.

5. The pair of operating members are an upper operating member provided adjacent to the upper gripping tool and a lower operating member provided adjacent to the lower gripping tool. The material testing machine according to claim 4.

6. The gripping tool includes a pair of gripping teeth for gripping a specimen, the operating member includes a first operating part on a first side in the width direction of the pair of gripping teeth and a second operating part on a second side in the width direction of the pair of gripping teeth. The material testing machine according to any one of claims 1 to 5.

7. The drive member is a hydraulic cylinder, and a hydraulic circuit connected to the hydraulic cylinder is configured to be able to supply hydraulic oil to the hydraulic cylinder by switching between high-pressure hydraulic oil for driving the hydraulic cylinder with a driving force suitable for the test and low-pressure hydraulic oil having a pressure lower than the high pressure for driving the hydraulic cylinder with a driving force suitable for setting the specimen. The material testing machine according to any one of claims 1 to 5.

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