JP2013156020A - Load application device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load application device which easily forms a target load distribution in a sample in accordance with a test objective.SOLUTION: A load application device is provided with a plurality of hydraulic jacks 16a to 16d, and operating rods 18a to 18d of the hydraulic jacks 16a to 16d are joined to an interface 20 by bolts and nuts 32a to 32d via flanges 30a to 30d. Loads applied to the hydraulic jacks 16a to 16d are applied to the sample 28 via the bolts 32a to 32d. A control unit 26 is provided with: a target load setting part 262 for setting a target load for each of the hydraulic jacks 16a to 16d; a comparator 264 for comparing the target load for every hydraulic jack set by the target load setting part 262 with load for every bolt detected by a distortion gauge 34; and a hydraulic jack control unit 266 for controlling operation of the respective hydraulic jacks 16a to 16d so that load applied by the respective hydraulic jacks 16a to 16d to the sample 28 becomes the target load.

Description

  The present invention relates to a load load device capable of detecting a load distribution applied to a specimen and controlling the load distribution to a target load distribution according to a test purpose based on the detected load distribution.

  Conventionally, in a tensile testing machine used for a material test or the like, generally, a uniaxial tensile test is performed on a fixed specimen and a load is applied in one direction. An example of the configuration of a testing machine that performs such a uniaxial tensile test will be described with reference to FIG. In FIG. 9, the uniaxial tensile testing machine 100 has actuators 104 and 104 erected on a stationary platen 102, and a column 106 arranged in the horizontal direction is supported by the actuators 104 and 104. The column 106 moves up and down while maintaining the horizontal posture by driving the actuators 104 and 104.

  The upper and lower ends of the specimen 124 are attached to the uniaxial tensile testing machine 100 via interfaces (connection parts) 112 and 114. The upper interface 112 is coupled to the column 106 via the load cell 108, and the upper end of the specimen 124 is attached to the upper interface 112 by the chuck 110. A support base 118 is fixed to the upper surface of the stationary base plate 102, and the lower end of the specimen 124 is attached to the lower interface 114 by a chuck 116.

  The column 106 is moved up and down by the actuators 104 and 104, and a load is applied to the specimen 124. The load detected by the load cell 108 is sent to the controller 120. A stroke sensor 122 is provided in the column 106 and the like, and the vertical position of the column 106 detected by the stroke sensor 122 is sent to the controller 120.

  In such a uniaxial tensile testing machine, since there is a single load point, only a unidirectional load distribution can be formed on the specimen 124. Therefore, it is impossible to form various load distributions according to the deformation behavior of the specimen. In addition, there is a limitation in the size of the chucks 110 and 116, which causes problems such as limiting the size of the specimen 124 and making it difficult to change the rated load of the actuator 104.

  Patent Document 1 discloses a compound load device that can simultaneously apply a torsional load and a bending load to a specimen. Further, Patent Document 2 discloses that a load can be applied to a specimen in a plurality of locations and in a plurality of directions, and unloading after reaching the maximum load can be safely performed without destroying the specimen. A compound load device having a load means is disclosed.

JP 2000-227392 A JP 2011-85444 A

  The devices disclosed in Patent Literature 1 and Patent Literature 2 do not have a function of detecting a load distribution applied to the specimen. Therefore, the load applied to the specimen cannot be monitored and this load cannot be controlled.

  In view of the problems of the prior art, the present invention solves the problems of the conventional uniaxial tensile testing machine, controls the load applied to the specimen, and sets the target load distribution according to the test purpose to the specimen. An object is to realize a loadable device that can be formed.

  In order to achieve this object, the load application device of the present invention applies a load to a specimen with a plurality of actuators. In addition, a fastening member that fastens the operating portion of each actuator and a load load point of the specimen, and a load detection device that is attached to the fastening member and detects a load applied to the fastening member for each fastening member. ing. In such a configuration, since a load is applied to the specimen from each actuator via the fastening member, the load applied to the specimen by each actuator can be detected for each actuator by the load detection device.

  In the present invention, the detection signal of the load detection device is further input, the target load for each fastening member set according to the load condition for the test purpose is compared with the detected load, and the load applied to each fastening member is calculated. A control device is provided for controlling the operation of the actuator so as to achieve a target load. Based on the input load detection signal, the control device controls the actuator so that the load load of each actuator becomes the target load. As a result, the load distribution formed on the specimen can be a target load distribution according to the test purpose.

  As described above, by using a plurality of actuators, independently controlling the operation of each actuator, and individually controlling the load load of each actuator, various load application patterns can be applied to the specimen. In addition, by adjusting the arrangement of a plurality of actuators, it is possible to deal with specimens of various sizes. Moreover, since the load applied to the specimen by each actuator can be detected for each actuator by detecting the load applied to the fastening member, it is easy to control the target load for each actuator based on these detected values. become.

  The target load for each actuator is set so that the target load distribution can be formed on the specimen by operating each actuator simultaneously. By setting an individual target load for each actuator, it becomes easy to form a target load distribution according to the test purpose, and the strength of the specimen can be inspected accurately and finely.

  The control device of the present invention compares target load setting means for setting a target load for each fastening member, and the target load set by the target load setting means and the load detected by the load detection device for each fastening member. It is preferable to include a comparator and actuator control means for controlling the operation of the actuator so that the load applied to each fastening member becomes the target load. Since the target load of each actuator is set for each actuator by the target load setting means, it is easy to form a target load distribution by the total load of a plurality of actuators loaded on the specimen.

  In the present invention, a fastening bolt can be used as the fastening member. As a result, the fastening member can be simplified and reduced in cost. Moreover, a strain gauge or a load cell can be used for a load detection apparatus, for example. The strain gauge only needs to be attached to the fastening member, and the load detection device can be simplified and reduced in cost.

  In the present invention, the plurality of actuators can load the specimen in the same direction at different points from each other, and can independently change the load and the load loading direction of each actuator loaded on the specimen. Good. As a result, a plurality of actuators can be arranged without taking up space, and various loads can be applied to the specimen. For example, the tensile load or the compressive load can be applied to the specimen by making the load load and the load direction of each actuator the same. On the other hand, a bending load can be applied to the specimen by changing the load load and load direction of each actuator.

  In addition to the above-described configuration, it is preferable to further include at least one actuator having different load application directions with respect to the plurality of actuators and the specimen. As a result, various load distributions can be formed by adding different bending loads and torsional loads.

  Further, in the present invention, the specimen is distributed in the circumferential direction of the hollow cylindrical body and the axial direction end of the hollow cylindrical body in a direction perpendicular to the axial direction of the hollow cylindrical body. The plurality of flanges are fixed to each other, and the plurality of flanges may be fastened to the operating portion of the actuator with fastening bolts. Accordingly, various loads as described above can be applied from the actuators to the hollow cylindrical body via the fastening bolts. Therefore, it is possible to accurately detect the strength of each part of the hollow cylindrical body. In addition, the strength of the fixed portion of the flange with respect to the hollow cylindrical body tends to be weak. However, the strength of the fixed portion can be accurately detected by applying an actuator load to the specimen through the flange.

  According to the present invention, various load application patterns can be applied to the specimen by using a plurality of actuators. In addition, the load of the fastening member that fastens the actuator and the specimen is detected, and the operation is controlled so as to be the target load for each actuator based on the detection value of the load detection device. It becomes easy to form a load distribution. Therefore, it becomes easy to form a target load distribution according to the test purpose, and the strength of the specimen can be inspected accurately and finely according to the application.

It is a lineblock diagram of a load detecting device concerning a 1st embodiment of the present invention. It is sectional drawing which follows the AA line in FIG. It is an arrangement plan of a hydraulic jack when the load detection device concerning a 1st embodiment is seen from the upper part. It is front view sectional drawing which shows a part of load detection apparatus which concerns on 1st Embodiment. It is a flowchart which shows the operation procedure of the load detection apparatus which concerns on 1st Embodiment. It is a block diagram of the load detection apparatus which concerns on 2nd Embodiment of this invention. It is a partial planar view explanatory drawing of the load detection apparatus which concerns on 2nd Embodiment. It is a partial planar view explanatory drawing of the load detection apparatus which concerns on 3rd Embodiment of this invention. It is a block diagram of the conventional uniaxial tensile testing machine.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention to that unless otherwise specified.

(Embodiment 1)
1st Embodiment of this invention is described based on FIGS. In FIG. 1, a load loading device 10 of the present embodiment is provided with a portal load frame 14 on the upper surface of a stationary stationary platen 12. Four hydraulic jacks 16a to 16d are fixed to the cross beam 14a of the portal load frame 14 with the operating rods 18a to 18d facing downward. FIG. 3 is a layout view of the hydraulic jacks 16a to 16d viewed from above. Hydraulic jack 16a~d is located the same distance from each center point O ₁ in the circumferential direction. The operating rods 18a to 18d of the hydraulic jacks 16a to 16d protrude downward, and the operating rods 18a to 18d move up and down by the operating oil supplied to the hydraulic jacks 16a to 16d.

  The operating rods 18a to 18d are arranged in the same direction, and the lower ends of the operating rods 18a to 18d are detachably coupled to the upper surface of the cylindrical upper interface 20. A support base 24 is fixed to the upper surface of the stationary base 12, and a lower interface 22 is attached to the upper surface of the support base 24. A specimen 28 having a hollow cylindrical shape is fastened to the upper and lower interfaces 20 and 22 by bolts 32a to 32d (see FIG. 2). The hydraulic jacks 16 a to 16 d are controlled by the control device 26 in the operating direction of the operating rods 18 a to 18 d and the load applied to the specimen 28.

As shown in FIG. 2, four square flanges 30 a to 30 d are fixed to the upper end of the specimen 28 at equal intervals in the circumferential direction. As shown in FIG. 4, screw holes 20 b and 31 are formed in these flanges and the bottom wall 20 a of the upper interface 20 corresponding to the flanges. Bolts 32a to 32d are screwed into these screw holes to fasten the upper interface 20 and the flanges. Specimen 28, the center point _{O 2} is arranged to coincide with the horizontal direction center point of the hydraulic jack 16a-d _{O 1} (see FIG. 3). Four flanges are also fixed to the lower end of the specimen 28 at equal intervals in the circumferential direction, and the lower end of the specimen 28 and the lower interface 22 are also coupled by the same coupling structure.

  A strain gauge 34 is affixed to each of the bolts 32a to 32d, and the load applied to the bolt can be detected by the strain gauge 34. This detection signal is sent to the control device 26. The strain gauge 34 can detect a load in three directions by using a three-axis gauge that can detect strain in three directions.

  The control device 26 includes a target load setting unit 262 for setting a target load for each of the hydraulic jacks 16a to 16d, a target load for each hydraulic jack set by the target load setting unit 262, and each bolt detected by the strain gauge 34. And a hydraulic jack control unit 266 for controlling the operation of each hydraulic jack 16a-d so that the load applied to the specimen 28 from each hydraulic jack 16a-d becomes a target load. And. The target load for each hydraulic jack set by the target load setting unit 262 can form a target load distribution on the specimen 28 by simultaneously operating the hydraulic jacks 16a to 16d.

  In such a configuration, when the hydraulic jacks 16a to 16d are operated so as to apply the same load to the specimen 28 in the same direction, a tensile load or a compressive load can be applied in the direction of the arrow a. Further, when the hydraulic jacks 16a to 16d are operated so as to apply different loads or loads in different directions to the specimen 28, a bending load in the arrow b direction can be applied. Moreover, it becomes possible to load desired load distribution with respect to the test body 28 by adjusting the operation direction and load load of each hydraulic jack 16a-d. As described above, by controlling the load load and the load direction of each of the hydraulic jacks 16a to 16d, various load distributions on the specimen 28 can be formed.

  As for the load applied to the specimen 28 from the hydraulic jacks 16a to 16d, the entire load needs to be applied to the specimen 28 via the bolts 32a to 32d. As a result, the load applied to the specimen 28 by the strain gauge 34 can be accurately detected. When a compression load is applied to the specimen 28 with the hydraulic jacks 16a to 16d, in order to apply the full load to the bolts 32a to 32d, a small gap is formed between the bottom wall 20a of the upper interface 20 and the flanges 30a to 30d. It is good to provide. On the other hand, when the screw holes 29b and 31 are made into fool holes and a nut is screwed onto the tip side of the bolts 32a to 32d to fasten the bottom wall 20a and the flanges 30a to 30d, the hydraulic jacks 16a to 16d are connected to the bolts 32a to 32d. It is difficult to apply the full compression load of d.

  Next, an operation procedure of the load device 10 will be described with reference to FIG. First, the target load setting unit 262 sets a target load distribution to be loaded on the specimen 28, and sets the target loads of the hydraulic jacks 16a to 16d that can form the target load distribution (S10). Next, the hydraulic jacks 16a to 16d are operated so as to form a target load distribution, and a load is applied to the specimen 28 (S12). Next, the load detection signal for each hydraulic jack detected by the strain gauge 34 attached to each bolt and nut 32a to 32d is sent to the comparator 264 of the control device 26 (S14).

  The comparator 264 compares the target load for each hydraulic jack with the load detection signal (S16). In each of the hydraulic jacks 16a to 16d, when the detected load differs from the target load, the hydraulic jack control unit 266 corrects the operation of the hydraulic jack having a different target load and detected load so that the detected load matches the target load. (S18). The hydraulic jack in which the target load and the detected load coincide with each other continues until the test is completed or another target load distribution is set (S20).

  According to the present embodiment, various load distributions can be formed on the specimen 28 by appropriately controlling the operating directions and load loads of the four hydraulic jacks 16a to 16d by the control device 26. Further, the full loads of the hydraulic jacks 16a to 16d are applied to the bolts 32a to 32d provided at equal intervals in the circumferential direction at the end of the specimen 28. Since this load load is detected and the operation of the hydraulic jacks 16a to 16d is controlled so as to obtain the target load for each hydraulic jack from these detected values, the target load distribution corresponding to the test purpose can be easily and easily applied to the specimen 28. It can be formed accurately. That is, a tensile load or a compressive load can be applied by applying the same load in the same direction with each hydraulic jack, and a bending load can be applied by applying a load of a different direction or a different value. Therefore, the strength of the specimen 28 can be accurately and finely inspected according to the application.

  Further, since the strain gauge 34 is used as the load detection means and the bolts 32a to 32d are used as the fastening means for fastening the upper and lower interfaces 20, 22 and the specimen 28, the configuration of the load load device 10 is simple and low cost. Can be Further, since the bolts 32a to 32d are fastened to the flanges 30a to 30d, the loads of the hydraulic jacks 16a to 16d can be accurately applied to the fixing portions of the flanges 30a to 30d having relatively low strength. Therefore, the strength of the fixed part can be accurately inspected.

  In the first embodiment, the strain gauge 34 is affixed to the bolts 32 a to 32 d and the load is detected. Instead of the strain gauge 34, a load cell is provided between the operating rods 18 a to 18 d and the upper interface 20. You may make it interpose.

(Embodiment 2)
Next, a second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, a hydraulic jack 36 is additionally provided in addition to the hydraulic jacks 16a to 16d. The hydraulic jack 36 is attached to a column 14 b of the portal load frame 14 that is erected on the stationary base 12. The operating rod 38 of the hydraulic jack 36 is disposed in the horizontal direction and is coupled to the outer peripheral surface of the interface 20. That is, as shown in FIG. 7, the actuating rod 38 is disposed in the upper interface 20 intersects the center point O ₃ of, and hydraulic jack 16b and 16c linear and parallel on the horizontal line d connecting the centers of. The operation of the hydraulic jack 36 is controlled by the control device 26. Other configurations are the same as those of the first embodiment.

  In the present embodiment, in addition to the operational effects obtained in the first embodiment, a load in the direction of arrow c can be applied to the specimen 28 by the hydraulic jack 36 together with the load load by the hydraulic jacks 16a to 16d. Therefore, a bending moment that cannot be loaded by the hydraulic jacks 16a to 16d can be applied to the specimen 28. Therefore, there is an advantage that more various load distributions can be applied to the specimen 28 than in the first embodiment.

(Embodiment 3)
Next, a third embodiment of the present invention will be described with reference to FIG. In the present embodiment, a pair of hydraulic jacks 40a and 40b are provided instead of the hydraulic jack 36 in the second embodiment. That is, the hydraulic jacks 40a, 40b is attached to the strut 14b of the portal load frame 14, these actuating rods 42a, 42b are arranged in the horizontal direction, and with intersecting at the center point _{O 3} of the interface 20, the hydraulic jack It arrange | positions on the horizontal line d parallel to the line | wire which connects the center of 16b and 16c.

The tips of the actuating rods 42 a and 42 b are coupled to the outer peripheral surface of the interface 20 that is equidistant from the center point O _{3 of} the interface 20. The operation of the hydraulic jacks 40 a and 40 b is controlled by the control device 26. Other configurations are the same as those of the first embodiment.

  According to this embodiment, it is possible to apply a bending load to the specimen 28 by making the operation directions of the hydraulic jacks 40a and 40b the same, and to reverse the operation direction of the hydraulic jacks 40a and 40b. 28 has an advantage that a torsional load can be applied.

  ADVANTAGE OF THE INVENTION According to this invention, the load load apparatus which can form easily the complicated target load distribution according to the test objective to a test body is realizable.

DESCRIPTION OF SYMBOLS 10 Load loading apparatus 12,102 Fixed standing board 14 Gate-type load frame 14a Horizontal girder 14b Post 16a-d, 36, 40a, 40b Hydraulic jack 18a-d, 38, 42a, 42b Actuating rod 20, 112 Upper interface 20b Bottom wall 20a , 31 Screw hole 22, 114 Lower interface 24, 118 Support base 26, 120 Control device 262 Target load setting unit 264 Comparator 266 Hydraulic jack control unit 28, 124 Specimen 30a-d Flange 32a-d Bolt and nut 34 Strain Gauge 100 Uniaxial tensile tester 104 Actuator 106 Column 108 Load cell 110, 116 Chuck 122 Stroke sensor O ₁ , O ₂ , O ₃ center point

Claims (7)

A plurality of actuators that apply loads to the specimen at different points,
Fastening members that fasten the operation parts of the plurality of actuators and the load load points of the specimen, respectively,
A load detection device mounted on the fastening member and detecting a load applied to the fastening member for each fastening member;
The detection signal of the load detection device is input, and the target load for each fastening member set according to the load condition for the test purpose is compared with the detected load so that the load applied to each fastening member becomes the target load. And a control device for controlling the operation of the actuator. The controller is
Target load setting means for setting a target load for each fastening member;
A comparator that compares the target load set by the target load setting means with the load detected by the load detection device for each fastening member;
The load loading device according to claim 1, further comprising actuator control means for controlling the actuator so that a load applied to each fastening member becomes a target load.   The load application device according to claim 1, wherein the fastening member is a fastening bolt.   The load load device according to claim 1, wherein the load detection device is a strain gauge or a load cell.   The plurality of actuators are capable of applying a load in the same direction at different points to the specimen, and capable of independently changing the load of each actuator loaded on the specimen and the load loading direction. The load application device according to claim 1 or 2.   The load device according to claim 5, further comprising at least one actuator having different load loading directions with respect to the plurality of actuators and the specimen.   The specimen is dispersed in the circumferential direction of the hollow cylindrical body and the axial direction end of the hollow cylindrical body, and is fixed in a direction perpendicular to the axial direction of the hollow cylindrical body. The load applying device according to claim 1, further comprising a plurality of flanges, wherein the plurality of flanges are fastened to the operating portion of the actuator by the fastening bolts.

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