KR101200250B1 - Fatigue testing machine using transverse flux linear motor - Google Patents

Abstract

The present invention relates to a fatigue tester, which excludes conventional rack-pinion gears and actuators such as servomotors, hydraulic servos, and pneumatic servos as an actuator for imparting tensile and compressive loads on specimens. By using a transverse flux linear motor with excellent, high speed and high precision control, low precision problems due to backlash and complexity of device configuration due to hydraulic and pneumatic peripherals can be solved, and miniaturization and weight reduction become possible. It relates to a fatigue tester. In particular, in the fatigue tester of the present invention, the actuator is characterized in that it has a thrust compensator for removing the influence of the weight of the actuator rod side to transfer the load to the specimen.

Description

Fatigue testing machine using transverse flux linear motor

The present invention relates to a fatigue tester, and more particularly, to a fatigue tester capable of measuring a fatigue limit by applying tensile and compressive loads to various specimens.

In general, a fatigue tester is a device that can accurately measure various fatigue limits such as tension, compression, and torsion for various kinds of specimens through ultra-high speed and ultra-precision repeat tests.

1 is a configuration diagram showing an example of a conventional fatigue tester, as shown, the conventional fatigue tester 10 is a main body 11 is provided with an actuator 100 for applying tensile and compressive loads , A crosshead 12 connected and installed by a column 13 at a position opposite to the main body 11, and a jig for fixing a specimen between the main body 11 and the crosshead 12 ( 14,15).

Here, the crosshead 12 may be installed to move up and down along the column 13 by a separate actuator (crosshead up and down driving actuator) with respect to the main body 11, the bottom portion of the crosshead 12 In the center, a load cell 16 is installed.

The jig (14, 15) is composed of a pair of the upper jig 14, which is installed to the crosshead 12 side, and the lower jig (15) is installed to the main body 11 side, the upper jig 14 is usually cross The lower jig 15 is installed on a rod 17 that is moved up and down by an actuator 100 for applying tension and compression loads in the main body 11. do.

As the actuator 100 for imparting tensile and compressive loads in the main body 11, a rack-pinion gear and servomotor method, a hydraulic servo method, and a pneumatic servo method may be applied, and the rods 17 may be applied by the actuators 100. ) Moves up and down to impart repetitive tensile and compressive loads to the specimen fixed to the upper jig 14 and the lower jig 15.

In the conventional actuator provided in the fatigue tester as described above, in the case of the rack-pinion gear and the servomotor method or the hydraulic servo method, it is pointed out that the low noise and excessive noise generation are disadvantages. In particular, the hydraulic servo method is a hydraulic drive using oil. Due to its characteristics, oil storage units, pumps, valves, and pipes are required for peripheral devices, which are complicated in configuration and increase in volume, weight, and price.

In addition, in the case of pneumatic servo type, the test speed is high, but it has the disadvantage of low precision with excessive noise.

This required a new type of fatigue tester with improved actuators.

Accordingly, the present invention is invented to solve the problems of the conventional actuator in the fatigue tester, the conventional rack-pinion gear and servomotor method or hydraulic servo method, as an actuator for imparting tensile and compressive loads on the specimens, By eliminating actuators such as pneumatic servo system and using a transverse flux linear motor with high thrust characteristics and high speed and high precision control, low precision problems due to backlash, and complexity of device configuration due to hydraulic and pneumatic peripherals It is an object of the present invention to provide a fatigue tester that can solve the problem and to be miniaturized and lightweight.

In addition, an object of the present invention is to provide a load-compensated fatigue tester that can eliminate the influence of the self-weight of the actuator rod side driven by the transverse flux linear motor in using the transverse flux linear motor.

In order to achieve the above object, the present invention, the main body is provided with an actuator for applying a load to the specimen, the crosshead is installed in a position opposite to the main body, and to fix the specimen between the main body and the crosshead In the fatigue tester including a jig for the, the actuator is connected to the jig and driven forward and backward up and down by the following transverse flux linear motor and transmits the thrust generated from the transverse flux linear motor to the specimen to tension or compressive load An actuator rod for applying; A frame installed in the main body so that the front and rear positions thereof are fixed to the traveling direction of the actuator rod; A transverse flux linear electric motor, which is formed between the actuator rod and the frame and drives the actuator rod back and forth from the frame in which the front and rear positions are fixed; A thrust compensating device which provides a compensation load for the weight of the actuator rod to compensate for the load transmitted to the specimen by the load due to the weight of the actuator rod; It provides a fatigue tester capable of compensating the load for the actuator weight, comprising a; controller for performing the drive and thrust control of the transverse flux linear motor.

Here, the thrust compensator, while supporting the actuator rod, the upper end is fastened to the lower end of the actuator rod is installed to be capable of tension or compression in the direction of the actuator rod and a compensation spring for transmitting a compensation load for the weight to the actuator rod and; A positioning mechanism which is installed to support the compensation spring from the lower side and is provided to adjust the support height of the compensation spring so that a compensation load is provided through the compensation spring; And a length change detection sensor configured to detect a change in length of the compensation spring and input the same to the controller.

In addition, the position adjustment mechanism, and the support is fixed to the inside of the main body; And a screw member having an upper end supporting the compensating spring connected to the lower end of the compensating spring so as to be fastened and released, and screwed up and down through the support to enable height adjustment up and down from the support. It features.

In addition, the controller calculates the spring force applied by the compensation spring based on the length change amount of the compensation spring detected by the length change detection sensor and the unique information data of the compensation spring stored in advance, and uses the spring force. It is characterized in that it is provided to compensate for the thrust command value for controlling the generated thrust of the lateral flux linear motor.

In addition, the unique information data of the compensation spring is characterized in that the spring constant data in a linear section in which the length of the compensation spring changes linearly with respect to the spring force.

In addition, the unique information data of the compensation spring is data in a linear section in which the length of the compensation spring changes linearly and in a non-linear section in which the compensation spring changes linearly with respect to the spring force. Characterized in that is the data of the force.

In addition, the lateral flux linear motor is characterized in that it comprises a mover which is provided integrally to the actuator rod, and a stator provided integrally to the frame.

In addition, the frame is provided with a tubular structure surrounding the actuator rod and the mover, the mover is installed in the central body portion of the actuator rod, the stator is installed on the inner surface of the frame in the opposite position with the air gap between the mover It is characterized by.

In addition, a plurality of mover-stator combinations comprising the mover and the stator at positions opposite to each other may be arranged around the actuator rod.

The apparatus may further include a position sensor installed to detect the front and rear positions of the actuator rod, and the controller controls the driving of the lateral flux linear motor and the front and rear of the actuator rod based on the position information of the actuator rod detected by the position sensor. Characterized in that to perform position control.

Accordingly, according to the fatigue tester according to the present invention, by adopting a transverse flux linear electric motor capable of various control of the thrust as an actuator for applying tensile and compressive load to the specimen fixed to the jig, high speed, high precision device configuration It becomes possible, and since the device configuration is simpler than the hydraulic method, there is an advantage that can be reduced in size and weight.

In addition, the fatigue tester according to the present invention has a thrust compensator that can eliminate the influence of the self-weight of the actuator rod side driven by the lateral flux linear motor, it is possible to more accurately apply the load and test measurement .

1 is a configuration diagram showing an example of a conventional fatigue tester.
Figure 2 is a perspective view showing the configuration of the actuator in the fatigue tester according to an embodiment of the present invention.
3 is an exploded perspective view showing the configuration of the actuator shown in FIG.
FIG. 4 is a perspective view of the actuator illustrated in FIG. 2 separately showing one side of the frame and the stator installed therein. FIG.
FIG. 5 is a plan view illustrating an arrangement of stators and movers in the actuator illustrated in FIG. 2.
6 is a longitudinal cross-sectional view of the actuator shown in FIG. 2.
FIG. 7 is a perspective view illustrating a stator and a mover of the transverse flux linear motor in the actuator illustrated in FIG. 2.
8 is a block diagram illustrating a configuration and a control method of a controller for controlling driving of an actuator in a fatigue tester according to an exemplary embodiment of the present invention.
9A and 9B are schematic diagrams illustrating characteristics of the hardening spring and the softening spring in the linear section and the nonlinear section.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

The present invention relates to a fatigue tester for measuring a fatigue limit by applying tensile and compressive loads to a specimen, and in particular, by improving an actuator for applying a load to a specimen, a conventional rack-pinion gear and servomotor method or hydraulic servo method, It is to solve the problems of actuators such as pneumatic servo system.

In particular, the fatigue tester of the present invention has a main characteristic of employing a transverse flux linear motor having excellent thrust characteristics and capable of high speed and high precision control as the actuator, and is low due to backlash when the transverse flux linear motor is used. The problem of precision, the complexity of device configuration due to hydraulic and pneumatic peripherals can be solved, and there is an advantage that the device can be configured by miniaturization and light weight.

In addition, the control of the drive unit and the load on the specimen can be controlled through the power control, which makes the device control simpler and simpler than the hydraulic and pneumatic servo method.

In the fatigue tester of the present invention, the actuator adopts a transverse flux linear motor, and has an actuator rod which is driven back and forth up and down by the generated thrust of the transverse linear motor to transfer the load to the specimen, and the actuator rod side during the test. The main feature is to provide a thrust compensator which compensates the load transmitted to the specimen by the weight of the actuator rod so that the influence of the weight of the actuator can be eliminated.

Except for the configuration of the actuator 100 which drives to impart tensile and compressive loads in the fatigue tester 10 according to the present invention, that is, the configuration in which the transverse flux linear electric motor 130 is employed as described in detail herein. The main body 11 on which the actuator 100 is installed, the crosshead 12 connected to and installed by a column 13 at a position opposite to the main body 11, the main body 11 and the crosshead ( 12) the configuration of the jig 14, 15, etc. for fixing the specimen is not different from the configuration of the conventional fatigue testing machine 10 (see Fig. 1).

For example, the crosshead 12 may be installed to be moved up and down along the column 13 by a separate actuator (crosshead vertical drive actuator) with respect to the main body 11.

In addition, a load cell 16 for load measurement is provided at the bottom of the crosshead 12, and a jig for fixing the specimen, that is, an upper jig 14, is installed on the load meter 16. In order to apply the lower jig 15 to the driving unit (actuator rod side) of the actuator 100 for driving forward and backward, there is no difference from the configuration of the conventional fatigue testing machine 10.

Therefore, in the present specification, the configuration of the actuator, which is a main feature of the present invention, will be described in detail with reference to the drawings of the preferred embodiment, and thus the general components of the fatigue tester except for the main features may be embodied in various forms. Detailed description will be omitted.

Figure 2 is a perspective view showing the configuration of the actuator in the fatigue tester according to an embodiment of the present invention, Figure 3 is an exploded perspective view showing the configuration of the actuator shown in Figure 2, Figure 4 is a view of the frame in the actuator shown in Figure 2 A perspective view showing one side and a stator installed thereon separately.

FIG. 5 is a plan view illustrating an arrangement of stators and movers in the actuator illustrated in FIG. 2, FIG. 6 is a longitudinal cross-sectional view of the actuator illustrated in FIG. 2, and FIG. 7 is a cross-sectional view of the linear flux motor in the actuator illustrated in FIG. 2. It is a perspective view which shows a stator and a mover structure.

First, the actuator 100 illustrated in FIG. 2 is installed inside the main body 11 of the fatigue tester 10 illustrated in FIG. 1, and has a lower jig 15 connected to one end thereof and has a horizontal flux linear motor ( Actuator rod is driven forward and backward up and down by the 130 and transmits the thrust generated from the transverse flux linear motor 130 to the specimen fixed to the upper jig 14 and the lower jig 15 to apply a tensile or compressive load ( And a frame 120 installed between the actuator rod 110 and the frame 120 so that the front and rear positions of the actuator rod 110 are fixed to the traveling direction of the actuator rod 110 within the main body 11. The transverse flux linear electric motor 130 which drives the actuator rod 110 forward and backward from the frame 120 having a fixed position, and a load transmitted to the specimen so as to remove the influence due to the self-weight of the actuator rod side. One 10) and a thrust compensator 170 for compensating for the load due to the weight of the magnetic weight of the side, and a controller (denoted by reference numeral 200 in FIG. 8) for controlling the driving and thrust of the lateral flux linear motor 130.

Here, the lateral flux linear electric motor 130 includes a mover 131 integrally formed with the actuator rod 110 and a stator 135 integrally formed with the frame 120 for linear driving of the actuator rod 110. It is configured to include).

In addition, the self-weight of the actuator rod 110 refers to the total weight of the component that is integrally installed on the actuator rod 110 itself and the actuator rod 110, the lateral flux linear motor 130 to the actuator rod 110 Since the mover 131 is integrally installed, it includes the weight of the actuator rod 110 and the mover 131.

In the above configuration, the actuator rod 110 is provided with the components constituting the mover 131 of the transverse flux linear motor 130 integrally installed and are separately coupled to the lower jig 15 or capable of transmitting loads. 1 may be connected to the lower jig 15 with an intervening (eg, a rod 17 in FIG. 1) interposed therebetween.

Accordingly, the actuator rod 110 can be driven back and forth by the thrust of the lateral flux linear motor 130, that is, the thrust generated in the gap between the mover 131 and the stator 135, and the thrust It is possible to apply an axial load, that is, a tensile or compressive load, to the specimen fixed between the upper jig 14 and the lower jig 15.

Next, the frame 120 is installed in the main body 11 so that the position is fixed in the front-rear direction (up and down direction in the drawing), which is the moving direction, with respect to the actuator rod 110 which is moved back and forth, in particular, the actuator rod ( 110 is provided with a tubular structure disposed to surround the mover 131, the components constituting the stator 135 of the transverse flux linear electric motor 130 is installed therein.

As described above, the frame 120 that is disposed to surround the actuator rod 110 and the mover 131 has a structure coupled to the actuator rod 110 by the LM guide 140 serving as a bearing. The actuator rod 110 and the mover 131 integrated therein may be guided in the axial direction (ie, the load direction), that is, the forward and backward movement direction, in the frame 120 having the front and rear positions fixed by the guide 140. It is.

The LM guide 140 maintains a gap between the stator 135 fixed to the frame 120 and the mover 131 fixed to the actuator rod 110, and also maintains the actuator rod 110 for fixing the specimen. When moving back and forth to the frame 120 and the stator 135 is fixed to the front and rear positions and serves to guide while maintaining a stable forward and backward movement of the actuator rod 110 and the mover 131.

In addition, the actuator rod 110 and the stator 135 serve to hold the actuator rod 110 and the stator 135 so as not to rotate relative to the frame 120.

The LM guide 140 is installed long along the axial direction of the actuator rod 110, that is, the movement direction thereof, as shown in the illustrated embodiment, the LM block (140) installed in the central body 111 of the actuator rod 110 ( 141 and the guide rail 142 installed on the inner surface of the stator iron core 136 at opposite positions thereof may be configured to be coupled to each other.

At this time, as shown, the mover 131 is installed in the central body portion 111 of the actuator rod 110, and the stator 135 is installed with a gap between the inner surface of the frame 120 at its opposite position. Therefore, the LM guide 140 is configured on both sides of the actuator rod 110 side and the frame 120 side at the position where the interaction between the mover 131 and the stator 135 is not hindered. As an example, the LM guide 140 may be interposed between the central body 111 of the actuator rod 110 and the stator core 136 on the frame 120 side in four directions.

On the other hand, the mover 131 and the stator 135 may be composed of the components of a conventional transverse flux linear motor, the mover 131 to the central body portion 111 of the actuator rod 110, the stator 135 ) Is fixedly installed on the inner surface of the frame 120, respectively, so that the mover 131 and the stator 135 of each phase are disposed at mutually opposite positions.

7 illustrates an example in which the mover 131 and the stator 135 are configured, and the mover 131 of each phase may be configured by assembling a plurality of iron cores 132 and a plurality of permanent magnets 133. Permanent magnets 133 are assembled between the iron cores 132 so as to have a structure in which the magnetic poles 132 are disposed so that the direction of magnetic poles is reversed between neighboring permanent magnets 133.

That is, the directions of the magnetic poles are arranged so that the directions of the magnetic poles can be alternately formed in the reverse direction as in the ← direction, and according to this arrangement, the magnetic poles of N and S are alternately generated in the iron core 132 of the mover 131. .

In addition, the mover iron core 132 and the permanent magnet 133 in each phase mover 131 has a structure having an electrical phase difference so that the thrust generated in the gap can occur in the moving direction (progression direction) of the actuator rod 110. That is, it is installed in a skew structure twisted by the pole spacing τ _p of the mover 131.

Referring to the drawings, it can be seen that both ends of the mover iron core 132 are positioned at the front and rear positions by the gap interval due to the skew structure.

On the other hand, the stator 135 is disposed at a predetermined interval of 2τ _p along the traveling direction of the mover 131 on the inner surface of the frame 120, and at this time, in a straight line on the same plane perpendicular to the traveling direction so as not to have a phase difference. It is a structure without the torsion arrange | positioned.

For example, the stator 135 may have a structure in which tooth portions 137 protruding toward the mover 131 are arranged at regular intervals of 2τ _p as illustrated, and two tooth portions on both sides at each position of the predetermined intervals. 137 is disposed on the same plane perpendicular to the moving direction of the mover 131, and windings 138 are provided on the tooth portions 137 on both sides.

The configuration and shape of each phase mover 131 and the stator 135 as described above can be implemented and controlled in the linear drive of the actuator rod 110 various configurations and forms known in the art of the conventional transverse flux linear motor Modification and replacement are possible.

For example, in the illustrated embodiment, the winding 138 is installed on the stator 135 side to minimize the influence of the weight of the actuator rod 110 and the mover 131, but the mover iron core 132 and the permanent magnet It is also possible to install the winding on the leg portions of both sides after the (133) is made in the 'c' shape.

In addition, in the illustrated embodiment, the mover 131 is disposed to have a skew structure by the pole spacing τ _p , but the two teeth portions on both sides of the stator 135 at respective positions at a predetermined interval so that the stator 135 has an electrical phase difference ( 137 may be arranged in a skew structure having a difference in front and rear positions by the polar interval τ _p . Of course, the mover 131 is arranged in a straight structure without twisting.

As illustrated in FIG. 5, a plurality of mover-stator combinations composed of the mover 131 and the stator 135 at positions opposing each other with a gap therebetween are disposed around the actuator rod 110. The two mover-stator combinations of the same phase may be disposed 180 ° from each other about the actuator rod 110 so that the suction force can be canceled.

In addition, a single phase two mover-stator combination may be installed or a plurality of phase mover-stator combinations may be installed around the actuator rod 110, and in the case of a plurality of phases, the mover 131 may move in the traveling direction (movement direction). It is possible to have the mover-stator combinations of different phases mixed when viewed on a vertical plane.

Referring to FIG. 5, the mover 131 is installed on all four surfaces of the central body part 111 of the actuator rod 110 having a quadrangular cross section inside the frame 120 having a quadrangular tube structure. The stator 135 is installed on all four sides of the inner surface so that the two mover-stator combinations of the first phase are arranged in the direction of 180 ° with respect to the actuator rod 110, and the mover-stator combination of the first phase The two mover-stator combinations of the second phase in the orthogonal direction are arranged in a 180 ° direction to each other.

Unlike the illustrated embodiment, a three-phase configuration is possible. In this case, although not illustrated in the drawing, the center body 111 of the actuator rod 110 having an octagonal cross section inside the frame 120 of an octagonal tube structure is provided. The mover 131 is installed on all eight surfaces, and the stator 135 is installed on all eight surfaces of the inner surface of the frame 120, so that the mover-stator combinations of phases A, B, and C are combined with each other. Mixed arrangements are made on a plane perpendicular to the direction of travel, with the two mover-stator combinations of each phase arranged in a 180 ° direction about the actuator rod 110 with each other.

In addition, the mover 131 and the stator 135 may be arranged in a polygonal shape on a plane to further increase the number of phases, and thus the number of phases may be variously configured.

That is, the mover 131 is installed on each side of the central body 111 of the actuator rod 110 having a polygonal cross section inside the frame 120 of the polygonal tubular structure, and on each side of the inner surface of the frame 120. The stator 135 is installed so that the mover-stator combinations of the respective phases are mixed and arranged on a plane perpendicular to the moving direction of the mover 131, wherein the two mover-stator combinations of the same phase are centered on the actuator rod 110 with each other. In the direction of 180 °.

As such, when the mover-stator combinations of different phases are mixed, large thrust can be obtained without increasing the overall length of the actuator 100 in the moving direction of the mover 131, and sufficient thrust of a necessary limit can be obtained. .

That is, when a multi-phase mover-stator combination is used, for example, when configured in three phases compared to two phases, the thrust can be increased without increasing the size in the longitudinal direction, and the actuator 100 in three phases compared to the two phases. The same thrust and load can be obtained by reducing the overall length of.

In addition, due to the characteristics of the lateral flux linear motor 130, the space in which current flows (electric circuit) and the space in which magnetic flux flows (separate circuit) are separated from each other. To change.

In addition, since each phase can be controlled independently, it is possible to control the generated thrust by one-phase single drive and multiple-phase (eg two-phase) simultaneous drive according to the required thrust. This enables phase discrimination and control of driving only one phase.

On the other hand, reference numeral 150 is a non-contact position sensor for detecting the front and rear positions of the actuator rod 110, the position sensor 150 detects the front and rear positions of the actuator rod 110 to be input to the controller.

When fixing or removing the specimen, the actuator rod 110 should be moved in the front-rear direction (up and down direction in the drawing), and in this case, the front and rear positions of the actuator rod 110 should be controlled, so that the controller detects the position sensor 150. The signal, that is, the position information of the actuator rod 110 is input to control the driving of the lateral flux linear motor 130, thereby controlling the front and rear positions of the actuator rod 110.

In a general transverse flux linear motor, a controller detects a position of a mover or a moving element through a position sensor, and then controls the position in the moving direction and controls the thrust. It is well known technology that can be applied to, and can be applied in various forms known by those skilled in the art.

As an example, as shown in FIGS. 3 and 5, a position sensor including a linear scale tape 151 for providing position information and a sensor head 152 for reading position information from the linear scale tape 151. 150 may be employed.

In this case, the linear scale tape 151 may be installed at the frame 120 side, and the sensor head 152 may be installed at the actuator rod 110 side. For example, the linear scale tape 151 may be the stator core 136. The inner side surface of the actuator rod 110 and the mover 131 may be attached long along the traveling direction.

In addition, the sensor head 152 is installed to face the linear scale tape 151 so as to read the position information recorded on the linear scale tape 151, it is fixed to the LM block 141 installed on the actuator rod 110 In this case, the support 153 may be installed on the LM block 141 and then the sensor head 152 may be installed on the support 153.

Accordingly, the sensor head 152 may be moved back and forth integrally with the actuator rod 110, and the position information is read while moving along the linear scale tape 151 when the actuator rod 110 moves.

As a result, the sensor head 152 moves along with the actuator rod 110 to read the information input to the linear scale tape 151 and transfer the information to the controller, and the sensor head 152 is the linear scale tape 151. It is possible to recognize the position of the actuator rod 110 based on the information read from the.

The information read from the linear scale tape 151 by the sensor head 152 becomes position information indicating the current position of the actuator rod 110.

The controller controls overall driving of the lateral flux linear motor 130, which is the fatigue tester and the actuator 100, and before and after the lateral flux linear motor 130 based on the position information detected by the position sensor 150. Genetic drive control, and the power control of the transverse flux linear motor 130 and thrust control through it.

That is, when the load is applied while controlling the linear drive of the actuator rod 110 from the detection signal of the position sensor 150 when fixing or removing the specimen as described above, by controlling the current applied to the winding 138. Thrust generated between the mover 131 and the stator 135 is controlled to precisely control the tensile and compressive loads applied to the specimen.

On the other hand, in the fatigue tester according to the present invention, the actuator 100, in addition to the actuator rod 110, the frame 120, the transverse flux linear electric motor 130, the actuator rod 110 to the load transmitted to the specimen It includes a thrust compensator 170 to compensate for the load due to its own weight so that the correct load is applied to the specimen.

When the thrust compensator 170 is provided, the influence due to the weight of the actuator rod 110 is removed, so that a more accurate test can be performed.

For example, the compression force of 1000 N should be applied to the specimen by the generated thrust 1000 N of the transverse flux linear motor 130, but the actuator rod 110 and the mover 131, sensor head 152, and the support which are integrally installed thereon Due to the magnetic weight of (153) and the like, the compressive load applied to the actual test specimen becomes as small as these magnetic weights.

The thrust compensator 170 compensates the load in the form of increasing the magnetic load (M × g) of the actuator rod 110 side to the compression load 1000N applied by the lateral flux linear motor 130, the lateral flux linear Load conditions are created so that a load of exactly 1000 N is applied to the specimen from the generated thrust of the motor 130.

As a preferred embodiment of the thrust compensator 170, as shown in Figures 2 to 4, is connected to the lower end of the actuator rod 110 to support the actuator rod 110 and at the same time of the actuator rod 110 Compensation spring 171 which is provided to be tensionable or compressible in a traveling direction and transmits a compensation load for its own weight to the actuator rod 110, and is installed to support the compensation spring 171 from the lower side and at the same time the compensation spring 171 It is configured to include a positioning mechanism 175 is provided to be able to adjust the height of the support to provide a compensation load through the compensation spring (171).

First, the compensation spring 171 has a structure in which the upper fastening end 172 is coupled to the upper end and the lower fastening end 173 is coupled to the lower end, and the upper fastening end 172 and the lower fastening end 173 are provided. It is coupled between the actuator rod 110 and the positioning mechanism 175.

At this time, the upper fastening end 172 is fastened by a fastening means such as a lower end of the upper actuator rod 110 and a screw 174a, and the lower fastening end 173 is a height variable portion 177 of the lower positioning mechanism 175. ) And a fastening means such as a screw 174b.

Here, in the case of the fastening means for fastening the lower fastening end 173 of the compensating spring 171 and the height variable portion 177 of the position adjustment mechanism 175 to each other, the height variable portion 177 after the release of the new test piece is released. Since it is necessary to fasten again after adjusting the height of the), in addition to the above screw 174b for fastening both sides, a known clamp, fastener, etc., which can be easily fastened and released can be used.

In addition, the position adjusting mechanism 175 is, as a preferred embodiment, a support 176 fixedly installed inside the main body of the fatigue tester, and a height variable part 177 installed to adjust the vertical height of the support 176. It is configured to include, the height variable portion 177 becomes a portion supporting the compensation spring (171).

Here, the height variable portion 177 may be a screw member which is screwed through the support 176 up and down.

At this time, the upper end of the screw member 177 is supported by the lower fastening end 173 of the compensation spring 171 and the fastening means such as screws, clamps, fasteners, etc. to support the compensation spring 171. ) Is integrally formed.

Accordingly, the tester can rotate the screw member 177 every time a new specimen is mounted to adjust the vertical height of the screw member 177, that is, the height supporting the compensation spring 171, and after the height adjustment, the screw member ( The support end 178 of the 177 is fastened to the lower fastening end 173 of the compensation spring 171.

In the above configuration, the tester adjusts the height of the height variable portion, that is, the screw member 177 after the specimen is mounted, so that the load due to the weight of the actuator rod 110 (M × g, where M is the actuator including the mover). The weight of the rod side, g is to adjust the support height of the compensation spring 171 so that gravity acceleration) is not applied to the specimen.

More specifically, the actuator rod 110 in a state where the specimen is fixed to the upper jig and the lower jig and the lower fastening end 173 of the compensation spring 171 is contacted and supported on the support end 178 of the screw member 177. The screw member 177 is rotated while the tester reads the load acting by the magnetic weight of the moving element 131 and the like, and the linear driver 130 is not driven.

When the screw member 177 is rotated to adjust the height of the screw member 177 and the height of supporting the compensation spring 171 up and down, the screw member whose value is 0, the load value due to its own weight is zero. When the position (height) of the 177 can be found, and thus the height for canceling the load by the self-weight is determined, the supporting end 178 of the screw member 177 and the lower fastening end 173 of the compensation spring 171 are provided. Are fastened completely to each other.

When supporting the lower fastening end 173 of the compensating spring 171 above the supporting end 178 of the screw member 177, the compensating spring 171 may be compressed by the weight of the actuator rod 110. When the adjustment mechanism 175 is operated, that is, when the height is adjusted by manipulating the screw member 177, which is the height variable part, the load downward due to its own weight is caused by the load acting upward through the compensation spring 171. It can be offset, and the load part due to its own weight can be compensated if the tension or compression test is made in this state.

On the other hand, when installing the position adjustment mechanism 175 to provide a compensating thrust in order to compensate for the load due to its own weight as described above, the component of the position adjustment mechanism 175 connected to the actuator rod 110 during the tension or compression test That is, it is necessary to remove or minimize the influence of the compensation spring 171.

That is, although the spring 171 is used for thrust compensation, it is necessary to suppress the dynamic change of the control object caused by the spring used.

More specifically, since the compensation spring 171 connected to the actuator rod 110 is tensioned or compressed when the actuator rod 110 is driven up and down by the linear motor 130 in the tension or compression test, the actual current In the process of controlling the generated thrust of the linear motor 110 through control (current control applied to the windings of the linear motor), thrust compensation to remove the influence of the force of the compensating spring 171 being tensioned or compressed is further added. Should be done.

For example, the compensation spring 171 is compressed when the actuator rod 110 is driven backwards to the linear motor 130 during the tensile test, so that in order to actually apply a specified tensile load to the specimen, the compensation spring 171 is compressed. The linear motor 130 must be controlled to generate thrust plus the required load.

On the contrary, the compensation spring 171 is tensioned when the actuator rod 110 is driven forward by the linear motor 130 during the compression test. Therefore, the compensation spring 171 is required to tension the compensation spring 171 to actually apply a predetermined compressive load to the specimen. The linear electric motor 130 must be controlled to generate a thrust plus a load to be added.

Accordingly, in the present invention, when the controller calculates the thrust (torque) command to remove the influence of the compensation spring 171, the thrust command value is changed by the force of the spring using the change of the length of the compensation spring 171 and the spring constant data. Compensation is made, the current command is calculated from the compensated thrust command value, and the current control applied to the winding and the generated thrust control of the linear motor 130 are performed by this current command.

In performing the control as described above, the controller should be able to know the change in the length of the compensation spring 171 during the tensile or compression test, so that the thrust compensator 170 detects the change in the length of the compensation spring 171. It is configured to include a sensor 179 to.

Referring to FIG. 6, an example in which the length change detection sensor 179 is installed in the compensation spring 171 is shown. The upper fastening end 172 of the compensation spring 171 is used as the length change detection sensor 179. The variable resistance sensor which detects the distance change (length change of the compensation spring) of both sides between the bottom fastening stage 173 and FIG. 1 is shown.

The length change detection sensor 179 is for detecting the degree of tension or compression of the compensation spring 171 during the test, after the tension or compression during the test from the initial position of the compensation spring 171, the specimen mounting and self-weight compensation is completed The change in length up to is detected, and the detected value is input to the controller.

In addition to the variable resistance sensor as illustrated, the length change detection sensor 179 detects a change in distance between the upper fastening end 172 and the lower fastening end 173 or the length change of the compensation spring 171, such as a linear scale sensor. One suitable form of known sensors that can be employed may be employed.

8 is a block diagram showing the configuration and control method of the controller 200 in the configuration of the actuator with the thrust compensator, the control target model on the right shows the control state of the linear motor.

Explanation of the code | symbol in FIG. 8 is as follows.

-x * Position command

-x: Actual position of linear motor (detected value of position sensor)

-v *: speed command

-v: actual speed of the linear motor

i *: current command

i: the actual current applied to the winding of the linear motor

-L: Inductance of linear motor

-R: winding resistance of linear motor

-K _T : Thrust (torque) constant of linear motor

-T _e *: Thrust (torque) command

-T _e : Actual generated thrust of the linear motor

k: spring constant

-M: Actuator rod side weight

-g: acceleration of gravity

-x _s : Length change amount of compensation spring (detected value of sensor for detecting length change)

Here, the actual position x of the linear motor 130 is a value detected by the position sensor 150, that is, the actual position value of the actuator rod 110, and x _s is detected by the length change detection sensor 179. Tension or compression length information of the compensation spring 171 is shown.

는 사용된 보상 스프링(171)의 스프링 상수 데이터를 나타낸다.And,

Denotes the spring constant data of the compensation spring 171 used.

Reference numeral 210 denotes a position control block, and reference numerals 220 and 230 denote speed control blocks and current control blocks, respectively.

In the configuration of the controller 200 as described above, a method of controlling the position of the actuator rod 110 in order to control the tensile and compressive load, that is to say with an example of the displacement control method, specific tensile or compressive load on the specimen The speed command (v *), thrust (torque) command (T _e *), and current command (i *) are sequentially calculated from the position command (x *) to give Based on the value of i *), the current applied to the winding 138 of the linear motor 130 is controlled to generate a desired thrust.

At this time, the position control block 210 in the controller 200 receives the actual position of the linear motor 130 detected from the position sensor 150, that is, the actual position x of the actuator rod 110. The control block 210 compares the actual position x of the actuator rod 110 with the position command x * value and generates and outputs a speed command v * that can compensate for the difference.

In addition, the speed control block 220 in the controller 200 receives the speed command v * and compares the actual speed of the linear motor 130 with the derivative value of the actuator rod position detected by the position sensor v. Calculate a thrust command _Te * to compensate for the difference.

)를 기초로 하여 보상 스프링(171)에 의해 가해지는 힘이 산출되고, 이어 보상 스프링(171)의 영향을 제거하기 위해 이 힘만큼을 추력명령(T_e*)에서 보상한 뒤 전류명령(i*)을 산출한다. In addition, in the controller 200, the length change amount x _s of the compensation spring 171 detected from the length change detection sensor 179 and the spring constant data (

The force exerted by the compensating spring 171 is calculated on the basis of, and the current command i is compensated by the thrust command _Te * to compensate for this force to remove the influence of the compensating spring 171. Calculate *)

As a result, the calculated current command i * is converted into the actual current value (actual current value applied to the winding) of the linear motor 130 detected by the current control block 230 by a current sensor (not shown) (i Compared with), the applied current is controlled so that the difference is zero.

In general, the transfer function from the generated thrust of the linear motor to the speed or position is expressed by the following equations (1) and (2).

(1)

(One)

(2)

(2)

Since the system of equations (1) and (2) both have a resonance mode as a secondary system, the problem of considering resonance in the configuration of the controller is raised, and thus the actual length change of the tension or compression of the compensation spring 171 By configuring the control logic as shown in Figure 8 to measure and reflect this can solve the problem of resonance.

The actual length variation in the tensile or compressive (detection ¹ of the sensor for detecting changes in length) x _s of the compensation spring 171 is in the longitudinal variation of the compensation spring 171 is shown for applying a tensile or compressive load in the test upon the specimen, the specimen It is a quantity that represents only the change from the initial position x ₀ of the compensation spring 171 in which the compression is adjusted to compensate for the load due to its own weight after installation. It is a concept of compensating only a portion due to the influence of the compensation spring 171 during the actual test excluding the compensation load).

)는 사용된 보상 스프링(171)에 대해 선행 실험 또는 해석을 통해 얻어지는 스프링 상수 데이터로, 컨트롤러(200) 내에 미리 입력, 저장되는 데이터이다.And, the spring constant data used in the control process (

) Is spring constant data obtained through a previous experiment or analysis on the compensation spring 171 used, and is data that is input and stored in advance in the controller 200.

)를 저장해놓은 상태에서, 컨트롤러(200)가 길이변화 검출용 센서(179)의 검출값인 길이변화량(x_s)을 입력받아, 스프링 상수(

)와 길이변화량(x_s)을 이용하여 스프링(171)에 의해 가해지는 힘(이하, 스프링 힘으로 칭함)을 산출해내고, 이를 추력명령(T_e*)을 보상하는데 사용한다.In the present invention, the unique information data for the compensation spring 171, that is, the spring constant data (preliminarily obtained through experiment or analysis)

), The controller 200 receives the length change amount x _s , which is a detection value of the length change detection sensor 179, and the spring constant (

) And the length change amount x _s to calculate the force applied by the spring 171 (hereinafter referred to as spring force), and use it to compensate for the thrust command _Te *.

)는 스프링 힘에 대해 보상 스프링(171)의 길이가 선형적으로 변화하는 선형 구간에서의 스프링 상수 데이터이다.Here, the spring constant data that is unique information data of the compensation spring 171 (

) Is spring constant data in a linear section in which the length of the compensating spring 171 changes linearly with respect to the spring force.

)를 정확히 알 수 있다면, 추력명령(T_e*)을 계산하는 부분에서 보상 스프링(171)으로 인한 영향을 줄일 수 있는 바, 공진에 대한 문제점을 개선시킬 수 있다.As such, the length change amount x _s of the compensation spring 171 and the spring constant (

If you can know exactly), it is possible to reduce the effect due to the compensation spring 171 in the part for calculating the thrust command (T _e *), it is possible to improve the problem with the resonance.

Preferably, it is possible to use the spring-specific data obtained by including both the linear section and the nonlinear section, in which case an accurate test considering the nonlinearity of the hardening spring or the softening spring becomes possible. .

)의 수식 계산으로부터 얻어질 수 있으나(F=

×x_s), 비선형 구간에서는 수식 계산으로부터 얻어질 수 없으므로, 선형 구간 및 비선형 구간 모두에서 선행 실험 또는 해석을 통해 데이터들을 얻어놓은 뒤 측정값인 길이변화량(x_s)으로부터 선형 구간 또는 비선형 구간의 스프링 힘(F)을 산출해는 것이다. That is, in the linear section, the spring force (F) is the length change (x _s ) and the spring constant (

Can be obtained from a mathematical calculation of

× x _s), non-linear region in the formula calculation obtained in the not be, the linear region and the nonlinear region of the back place both at obtaining data on the preceding experiment or analysis on the measured values of length variation (x _s) linear region or from a non-linear section from the Calculate the spring force (F).

), 스프링 힘(F)의 데이터, 적어도 길이변화량(x_s)과 각 길이변화량에 상응하는 스프링 힘(F)의 데이터가 컨트롤러(200)에 룩 업 테이블 형태로 저장될 수 있으며, 이렇게 저장된 룩 업 테이블 정보를 기초로 하여 컨트롤러(200)가 길이변화 검출용 센서(179)의 검출값인 길이변화량(x_s)으로부터 스프링 힘(F)을 추출하여 추력명령(T_e*)을 보상하는데 이용하게 된다.For this purpose, the length change (x _s ), spring constant data (

), The data of the spring force (F), at least the length change amount (x _s ) and the data of the spring force (F) corresponding to each length change amount may be stored in the controller 200 in the form of a look-up table, Based on the up table information, the controller 200 extracts the spring force F from the length change amount x _s , which is a detection value of the length change detection sensor 179, and compensates the thrust command _Te *. Done.

9A and 9B are schematic views illustrating the characteristics of the hardening spring and the softening spring in the linear section and the non-linear section, wherein the linear characteristic in which the length X of the compensation spring changes linearly with respect to the spring force F and A diagram showing nonlinear characteristics that change nonlinearly.

In this way, in the fatigue tester according to the present invention by employing a transverse flux linear electric motor 130 that can control a variety of thrust as the actuator 100 for applying the tensile and compressive load to the specimen fixed to the jig The high speed, high precision device configuration is possible, and the device configuration is simpler than the pneumatic method, so that the size and weight can be reduced.

In particular, in the fatigue tester according to the present invention, the thrust compensator 170 using the spring 171 is provided, so that the influence of the self-weight on the actuator rod 130 side can be eliminated, so that an accurate test can be made.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the present invention is not limited to the disclosed exemplary embodiments. Modified forms are also included within the scope of the present invention.

10: fatigue tester 11: main body
12 crosshead 13 column
14: upper jig 15: lower jig
16: load gauge 17: rod
100: actuator 110: actuator rod
111: body 120: frame
130: transverse flux linear motor 131: mover
132: iron core 133: permanent magnet
135: stator 136: stator iron core
137: tooth part 138: winding
140: LM Guide 141: LM Block
142: guide rail 150: position sensor
151 linear scale tape 152 sensor head
153: support 170: thrust compensator
171: compensation spring 172: upper fastening end
173: lower fastening step 175: position adjustment mechanism
176: support 177: screw member (height variable portion)
178: support end 179: length change sensor
200: controller

Claims (10)

A main body 11 on which an actuator 100 for applying a load to a specimen is installed, a crosshead 12 installed at a position opposite to the main body 11, the main body 11 and a crosshead 12 In the fatigue tester (10) comprising a jig (14, 15) for fixing the specimen between,
The actuator 100,
An actuator rod connected to the jig 15 and driven back and forth by the following transverse flux linear motor 130 and transmitting a thrust generated from the transverse flux linear motor 130 to the specimen to apply a tensile or compressive load ( 110);
A frame 120 installed in the main body 11 so that the front and rear positions thereof are fixed to the traveling direction of the actuator rod 110;
A transverse flux linear electric motor 130 which is configured between the actuator rod 110 and the frame 120 to drive the actuator rod 110 forward and backward from the frame 120 having a fixed front and rear position;
A thrust compensator (170) for providing the actuator rod (110) with a compensation load for its own weight to compensate for the load transmitted to the specimen by the load due to the weight of the actuator rod (110);
A controller (200) for performing drive and thrust control of the transverse flux linear motor (130);
Fatigue tester capable of compensating the load for the actuator weight, characterized in that it comprises a.
The method according to claim 1,
The thrust compensation device 170,
While supporting the actuator rod 110 and the upper end is fastened to the lower end of the actuator rod 110 is installed to be capable of tension or compression in the advancing direction of the actuator rod 110 and the compensation load for its own weight to the actuator rod 110 A compensation spring 171 for transmitting;
A positioning mechanism (175) installed to support the compensation spring (171) from the lower side and at the same time provided to adjust the support height of the compensation spring (171) so that a compensation load is provided through the compensation spring (171);
A length change detection sensor 179 which detects a change in length of the compensation spring 171 and inputs it to the controller 200;
Fatigue tester that is capable of compensating the load for the actuator weight, characterized in that it comprises a.
The method according to claim 2,
The position adjustment mechanism 175,
A support 176 fixedly installed in the main body 11;
The upper end supporting the compensation spring 171 is connected to the lower end of the compensation spring 171 so as to be fastened and released, and penetrates the support 176 up and down so that the height of the support 176 can be adjusted up and down. A screw member 177 to be screwed in;
Fatigue tester that is capable of compensating the load for the actuator weight, characterized in that it comprises a.
The method according to claim 2,
The controller 200 is provided to the compensation spring 171 based on the length change amount of the compensation spring 171 detected by the length change detection sensor 179 and the unique information data of the compensation spring 171 stored in advance. Compensation of the load applied to the actuator weight, characterized in that to calculate the spring force applied by the compensation, the thrust command value for controlling the generated thrust of the lateral flux linear motor 130 by using the spring force Fatigue testing machine.
The method of claim 4,
The inherent information data of the compensation spring 171 is spring constant data in a linear section in which the length of the compensation spring 171 changes linearly with respect to the spring force. Fatigue testing machine.
The method of claim 4,
The unique information data of the compensation spring 171 is data in a linear section in which the length of the compensation spring 171 changes linearly and in a non-linear section in which the length of the compensation spring changes linearly with respect to the spring force. A fatigue tester capable of compensating load for an actuator's own weight, which is data of a spring force corresponding to a change amount.
The method according to claim 1,
The horizontal magnetic flux linear motor 130 includes a mover 131 integrally provided at the actuator rod 110 and a stator 135 integrally provided at the frame 120. Fatigue tester with load compensation.
The method of claim 7,
The frame 120 has a tubular structure surrounding the actuator rod 110 and the mover 131, and the mover 131 is formed on the central body portion 111 of the actuator rod 110, and the stator 135. Fatigue tester is possible to compensate for the load of the actuator, characterized in that is installed on the inner surface of the frame 120 in the opposite position with the mover 131 and the gap between.
The method according to claim 8,
A plurality of mover-stator combinations composed of the mover 131 and the stator 135 at positions opposite to each other are disposed around the actuator rod 110 to allow load compensation for the actuator weight. Testing machine.
The method according to claim 1,
Further comprising a position sensor 150 is installed to detect the front and rear positions of the actuator rod 110, the controller based on the position information of the actuator rod 110 is detected through the position sensor 150 A fatigue tester capable of compensating the load for the actuator weight, characterized in that the drive control of the high speed linear motor 130 and the front and rear position control of the actuator rod 110 are performed.

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