JP5821581B2 - Endurance test equipment - Google Patents

Description

  The present invention relates to an endurance test apparatus for performing an endurance test by applying a test force to a specimen, and in particular, an endurance test apparatus for performing an endurance test on a specimen having a moving member that moves by driving an actuator. About.

  A durability test apparatus that tests the durability of a specimen by repeatedly applying a test force to the specimen using a hydraulic cylinder or the like is used in, for example, a vehicle durability test (Patent Document 1). reference).

  The servo control mechanism in such an endurance test apparatus constantly measures the magnitude of the load on the specimen and the amount of displacement of the specimen, and a predetermined control gain with respect to the difference (deviation) between the target value and the feedback signal. An actuator such as a hydraulic cylinder is controlled by using a control signal obtained by multiplying.

  Here, when the specimen is a test piece or a passive component that is deformed when stress is applied, the control gain used for feedback control largely depends on the rigidity of the specimen. That is, when the rigidity of the specimen is high, the actuator generates a large load with a small stroke amount, and therefore it is necessary to set the control gain small. On the other hand, when the rigidity of the specimen is low, the actuator stroke required for generating the load becomes large, so that the control gain needs to be set large.

  The durability test apparatus described in Patent Document 1 described above is intended for a stationary specimen such as a vehicle. On the other hand, an actuator such as a motor is mounted on the specimen, and it may be necessary to evaluate the durability in a state where the specimen is driven by the actuator. FIG. 3 is a schematic diagram showing a test mode by a conventional durability test apparatus that evaluates the durability of a specimen 72 that has been driven by an actuator. These durability test apparatuses are for performing a durability test on a specimen 72 including a moving member 73 that is expanded and contracted by an actuator. The specimen 72 is fixed on the base 71.

  The durability test apparatus shown in FIG. 3A has a configuration in which a weight 82 is connected to a moving member 73 in a specimen 72 via a wire 81. In this durability test apparatus, the endurance test can be executed in a state where a constant tensile load is always applied to the moving member 73 by reciprocating the moving member 73 in the specimen 72. .

  The durability test apparatus shown in FIG. 3B has a configuration in which a cylinder rod 84 in a hydraulic cylinder 83 is connected to a moving member 73 in a specimen 72 via a load detector 85 such as a load cell. In this durability test apparatus, the moving member 73 in the specimen 72 is reciprocated, and the pressure in the hydraulic cylinder 83 is maintained at a constant pressure using a relief valve or the like, so that a constant load is applied. It becomes possible to execute an endurance test.

  The durability test apparatus shown in FIG. 3C has a configuration in which a rod 87 connected to a spring 86 is connected to a moving member 73 in a specimen 72 via a load detector 85 such as a load cell. In this durability test apparatus, a load proportional to the stroke amount of the moving member 73 can be applied to the specimen 72.

  By the way, a durability test for evaluating durability is performed by attaching a control valve such as a servo valve to the durability test apparatus shown in FIG. 3B and applying a load to the specimen 72 driven by the actuator. In this case, it is necessary to generate a load on the specimen 72 while moving the cylinder rod 84 of the hydraulic cylinder 83 in the durability test apparatus in accordance with the movement stroke of the moving member 73 in the specimen 72. In such a case, even when the specimen 72 has high rigidity, if the moving stroke of the moving member 73 in the specimen 72 is large, the cylinder rod 84 of the hydraulic cylinder 83 also needs to be moved with a large stroke. For this reason, when the rigidity of the specimen is high, the relationship of setting the control gain to be small does not hold.

  In such a case, when normal servo control is performed, an attempt is made to control the load received by the specimen using the hydraulic cylinder 83 of the durability test apparatus while moving the moving member of the specimen having high rigidity. The movement of the cylinder rod 84 of the hydraulic cylinder 83 of the durability test apparatus cannot follow the moving speed of the moving member, and the actuator in the specimen may be overloaded. Further, when the control gain is increased in order to improve the followability of the hydraulic cylinder 83 in the durability test apparatus, there is a problem that a hunting phenomenon occurs.

  For this reason, by interposing an elastic mechanism using a leaf spring between the cylinder rod in the hydraulic cylinder and the moving member in the specimen, the followability of the hydraulic cylinder is improved while preventing the occurrence of hunting phenomenon. A durability test apparatus has been proposed (see Patent Document 2).

JP 2007-303893 A JP 2011-180106 A

  The durability test apparatus described in Patent Document 2 has the following characteristics of the hydraulic cylinder without causing a hunting phenomenon even when the rigidity of the entire load system is reduced by an elastic mechanism and the control gain of the hydraulic cylinder is set to a large value. However, it is necessary to replace the leaf spring of the elastic mechanism with a leaf spring with a different spring constant according to the magnitude of the load on the specimen and the rate of change of the load. There is a problem that it takes time and effort. In addition, there is a limit to the performance of the leaf spring that can be used for the elastic mechanism, and the hydraulic cylinder may not be able to follow the moving speed of the moving member of the specimen.

  The present invention has been made to solve the above-described problem. When a test force is applied to a specimen provided with a moving member that moves by driving an actuator, the influence on load control due to the movement of the moving member. It is an object of the present invention to provide a durability test apparatus in which the followability of a load actuator is improved.

  The invention according to claim 1 is an durability test apparatus for performing an endurance test by applying a test force to a specimen provided with a moving member that moves by driving of an actuator, and fixes the specimen. A base having a mounting portion, a stroke detector for detecting a stroke amount of the moving member, a load actuator for applying a load to the moving member in the specimen, and disposed on the base. A slide mechanism that is connected to the load actuator and allows the load actuator to move horizontally in the load axis direction, a movement actuator that is fixed on the base and moves the load actuator, and the stroke detection A moving actuator that operates the moving actuator in accordance with a stroke amount of the moving member detected by a detector. Characterized by comprising a motor control mechanism.

  The invention according to claim 2 is the invention according to claim 1, wherein a load detector that detects a load received by the specimen, a second stroke detector that detects a stroke amount of the load actuator, A load for operating the load actuator using a third stroke detector that detects the stroke amount of the moving actuator and the detection signal received from the load detector or the second stroke detector as feedback information. An actuator control mechanism, and the movement actuator control mechanism utilizes a detection signal received from a stroke detector that detects a stroke amount of the moving member and the third stroke detector, The moving actuator is operated.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the load actuator and the moving actuator are hydraulic cylinders.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the actuator in the specimen is a motor.

  According to the first to fourth aspects of the present invention, in the durability test apparatus for performing a durability test by applying a test force to a specimen provided with a moving member that moves by driving of the actuator, the load actuator Since the load actuator is moved by controlling the operation of the moving actuator according to the stroke amount of the moving member of the specimen, the movement of the moving member of the specimen has an influence on the load control. The influence can be reduced. For this reason, the stability of the load control is improved, and it is possible to execute an endurance test in which the followability of the load actuator is good even with a specimen provided with a moving member.

1 is a schematic diagram of a durability test apparatus 10 according to the present invention. 3 is a block diagram of a control system of the durability test apparatus 10. FIG. It is a schematic diagram which shows the test aspect by the conventional durability test apparatus which evaluates durability with respect to the specimen 72 which performed the drive by an actuator.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of an endurance test apparatus 10 according to the present invention.

  This durability test apparatus 10 performs an endurance test on the specimen 20 fixed to the specimen mounting part on the base 11. The specimen 20 includes a motor 21 as an actuator, and has a configuration in which a rod 22 as a moving member is reciprocated with a predetermined stroke. Such specimens are used in industrial robots, transport steering devices, power assist devices, and the like.

  The durability test apparatus 10 according to the present invention includes a hydraulic cylinder 31 as a load actuator that applies a load to the specimen 20 and a hydraulic cylinder 41 as a moving actuator that moves the hydraulic cylinder 31 in the load axis direction. . The hydraulic cylinder 31 and the hydraulic cylinder 41 are arranged in series on the base 11.

  The hydraulic cylinder 31 includes a control valve 33 for controlling the reciprocation of the cylinder rod 32 and a stroke detector 35 for detecting the movement stroke of the cylinder rod 32. The cylinder rod 32 of the hydraulic cylinder 31 is connected to the rod 22 of the specimen 20 via the load cell 12 that is a load detector and the connection member 26. The hydraulic cylinder 31 is disposed on the base 11 via a slide mechanism 39 that allows horizontal movement in the load axis direction.

  The hydraulic cylinder 41 includes a control valve 43 for controlling the reciprocating movement of the cylinder rod 42 and a stroke detector 45 for detecting the movement stroke of the cylinder rod 42. The hydraulic cylinder 42 is fixed on the base 11 by a fixture 49. The cylinder rod 42 of the hydraulic cylinder 41 is connected to the hydraulic cylinder 31 via a connection member 36. Accordingly, the hydraulic cylinder 42 horizontally moves the hydraulic cylinder 31 on the base 11 by a distance corresponding to the stroke amount of the cylinder rod 42.

  FIG. 2 is a block diagram of a control system of the durability test apparatus 10.

  The durability test apparatus 10 is controlled as a whole by a control device (not shown) including a RAM and ROM as storage devices and a CPU as an arithmetic device. The durability test apparatus 10 includes a load actuator control mechanism 51 and a movement actuator control mechanism 52 that use the storage / calculation function of the control device. Note that the load actuator control mechanism 51 controls the hydraulic cylinder 31, and the movement actuator control mechanism 52 controls the hydraulic cylinder 41.

  When the durability test is performed by the durability test apparatus 10, a drive signal is given to the motor 21 in the specimen 20 from the specimen control unit 53 to move the rod 22, as shown in FIG. The stroke amount of the rod 22 at this time is detected by the stroke detector 25. The detection signal of the stroke detector 25 is used as a movement command signal for the cylinder rod 42 of the hydraulic cylinder 41 via the amplifier 61 in the movement actuator control mechanism 52.

  The movement of the cylinder rod 42 of the hydraulic cylinder 41 is realized by adjusting the drive of the control valve 43. The stroke amount of the cylinder rod 42 of the hydraulic cylinder 41 is detected by a stroke detector 45. The detection signal of the stroke detector 45 is fed back via the amplifier 62 to the movement command signal. Then, a drive signal for the control valve 43 corresponding to the deviation between the movement command signal and the detection signal from the stroke detector 45 is given to the hydraulic cylinder 41 via the amplifier 63, so that the stroke amount of the rod 22 in the specimen 20 is increased. The operation of the corresponding hydraulic cylinder 41 is performed.

  Here, the stroke amount of the cylinder rod 42 in the hydraulic cylinder 41 is the amount of movement of the hydraulic cylinder 31 connected to the cylinder rod 42 in the load axis direction by the slide mechanism 39. When the hydraulic cylinder 41 operates, the hydraulic cylinder 31 moves horizontally on the base 11 by a distance corresponding to the stroke amount of the cylinder rod 42.

  The movement of the cylinder rod 32 of the hydraulic cylinder 31 is realized by adjusting the drive of the control valve 33. The stroke amount of the cylinder rod 32 of the hydraulic cylinder 31 is detected by a stroke detector 35. Further, the load on the specimen 20 generated by the reciprocating motion of the cylinder rod 32 of the hydraulic cylinder 31 is detected by the load cell 12. In the load actuator control mechanism 51, a load or stroke amount detection signal selected as the control amount is fed back to the target value signal (load waveform signal) from the waveform generation unit 52.

  That is, when the load is selected as the control amount, the detection signal of the load cell 12 is fed back via the amplifier 65, and the control valve 33 according to the deviation between the target value signal from the waveform generator 52 and the detection signal. The drive signal is supplied to the hydraulic cylinder 31 via the amplifier 64. Further, when the stroke amount is selected as the control amount, the detection signal of the stroke detector 35 is fed back via the amplifier 66, and according to the deviation between the target value signal from the waveform generator 52 and the detection signal. A drive signal for the control valve 33 is supplied to the hydraulic cylinder 31 via the amplifier 64.

  When the endurance test of the specimen 20 is executed in the endurance test apparatus 10 having the above-described configuration, the cylinder rod 32 of the hydraulic cylinder 31 is fixed in a state where the position of the motor 21 of the specimen 20 is controlled and the rod 22 is fixed. By reciprocating the rod 22, the rod 22 can be continuously pressed and pulled to apply vibration to the specimen 20. In this case, the specimen 20 is deformed by the load force from the hydraulic cylinder 31.

  On the other hand, when the durability test is performed while the rod 22 of the specimen 20 is reciprocated, the cylinder rod 32 of the hydraulic cylinder 31 is moved while the hydraulic cylinder 31 is moved in accordance with the reciprocating motion of the rod 22 of the specimen 20. Endurance test is performed in the state of reciprocation.

  Conventionally, in such an endurance test, control for moving the cylinder rod 32 of the hydraulic cylinder 31 in consideration of the stroke amount of the rod 22 has been performed in order to give a target load to the specimen 20. However, when the rigidity of the specimen 20 is high, the movement of the cylinder rod 32 of the hydraulic cylinder 31 cannot follow the reciprocating speed of the rod 22 of the specimen 20 as described above. In some cases, the motor 21 becomes overloaded. In order to cope with this, if the control gain for controlling the hydraulic cylinder 31 is increased, a hunting phenomenon occurs and the control becomes unstable. The rigidity of the specimen 20 is the mechanical rigidity of the whole specimen 20, and the apparent rigidity of the specimen 20 including the motor 21 as an actuator and the rod 22 reciprocated by the motor 21. means.

  In the durability test apparatus 10 according to the present invention, the hydraulic cylinder 31 is movable by the slide mechanism 39. The hydraulic cylinder 31 itself moves horizontally on the base 11 in the direction of the load axis in accordance with the movement of the cylinder rod 42 by the hydraulic cylinder 41 that operates according to the stroke amount of the rod 22 of the specimen 20. Thus, the reciprocating motion of the rod 22 of the specimen 20 is absorbed by the horizontal movement of the hydraulic cylinder 31 by the slide mechanism 39. Therefore, when viewed from the hydraulic cylinder 31 side, the specimen 20 is almost in the same state as the state in which the motor 21 is stopped and the rod 22 is not moved. That is, even when the rod 22 of the specimen 20 is reciprocated, the hydraulic cylinder 31 is provided in the same manner as in the durability test performed with the rod 22 fixed by controlling the position of the motor 21 of the specimen 20. A load force can be applied to the specimen 20.

  In the durability test apparatus 10 described above, assuming that the deformation amount of the specimen 20 with respect to the load P is Xp, the stroke amount of the rod 22 in the specimen 20 is Xt, and the stroke amount of the hydraulic cylinder 41 is Xm, the load P is applied to the specimen 20. The stroke amount Xf of the cylinder rod 32 of the hydraulic cylinder 31 at the time of giving is expressed by the following formula (1).

Xf = Xp + Xt−Xm (1)
Here, for example, when the moving member of the specimen 20 is a spring-type member, assuming that the spring constant is K, the deformation amount Xp of the specimen 20 is Xp = P / K.

  In this durability test apparatus 10, the movement of the hydraulic cylinder 42 is controlled by the moving actuator control mechanism 52 so that Xt−Xm becomes substantially zero, so that the cylinder rod of the hydraulic cylinder 31 shown in Expression (1) is obtained. The stroke amount Xf of 32 can be set to substantially the same value as the deformation amount Xp of the specimen 20. That is, even when the rod 22 of the specimen 20 is reciprocatingly moved, the rod 21 is fixed by apparently holding and controlling the motor 21 of the specimen 20, and the material piece or the passive component (deformed by the force is deformed). Load control similar to the case where a load is applied to such a component).

  As described above, in the durability test apparatus 10 according to the present invention, the position of the hydraulic cylinder 31 on the base 11 is changed according to the amount of movement of the rod 20 of the specimen 20 by the moving actuator control mechanism 52. Thus, the influence of the movement of the rod 22 of the specimen 20 on the load control is reduced, and the followability of the hydraulic cylinder 31 with respect to the reciprocating speed of the rod 22 of the specimen 20 is improved. For this reason, only the movement of the cylinder rod 32 of the hydraulic cylinder 31 is controlled, and the control gain of the hydraulic cylinder 31 is set to be larger than that of the conventional durability test apparatus that is made to follow the reciprocating speed of the rod 22 of the specimen 20. This is unnecessary, and the effect of preventing the occurrence of the hunting phenomenon can be enhanced. Therefore, it becomes possible to make the load control more stable while improving the followability of the load system with respect to the reciprocating movement of the rod 22 by the motor 21 in the specimen 20.

  In the above-described embodiment, the durability test is performed while the rod 22 as the moving member is reciprocated by a predetermined stroke by driving the motor 21 as the actuator in the specimen 20. However, the movement of the moving member by driving the actuator is not necessarily a reciprocating motion. That is, the present invention can be applied to a durability test apparatus that performs a durability test by applying vibration to a specimen having a moving member that moves only in one direction.

DESCRIPTION OF SYMBOLS 10 Endurance test apparatus 11 Base 12 Load cell 20 Specimen 21 Motor 22 Rod 31 Hydraulic cylinder 32 Cylinder rod 33 Control valve 35 Stroke detector 39 Slide mechanism 41 Hydraulic cylinder 42 Cylinder rod 43 Control valve 45 Stroke detector 49 Fixing tool 51 Load Actuator control mechanism 52 Actuator control mechanism for movement 53 Specimen control section 54 Waveform generator 61 Amplifier 62 Amplifier 63 Amplifier 64 Amplifier 65 Amplifier 66 Amplifier

Claims (4)

An endurance test device for performing an endurance test by applying a test force to a specimen provided with a moving member that moves by driving of an actuator,
A base having a mounting portion for fixing the specimen;
A stroke detector for detecting a stroke amount of the moving member;
A load actuator for applying a load to the moving member in the specimen;
A slide mechanism disposed on the base and connected to the load actuator, and allowing horizontal movement of the load actuator in the load axis direction;
A moving actuator fixed on the base and moving the load actuator;
A moving actuator control mechanism for operating the moving actuator according to the stroke amount of the moving member detected by the stroke detector;
An endurance test apparatus characterized by comprising: The durability test apparatus according to claim 1,
A load detector for detecting a load received by the specimen;
A second stroke detector for detecting a stroke amount of the load actuator;
A third stroke detector for detecting a stroke amount of the moving actuator;
A load actuator control mechanism for operating the load actuator with the detection signal received from the load detector or the second stroke detector as feedback information;
Further comprising
The movement actuator control mechanism uses a detection signal received from a stroke detector that detects a stroke amount of the moving member and the third stroke detector, to operate the movement actuator. . In the durability test apparatus according to claim 1 or 2,
The durability testing apparatus, wherein the load actuator and the moving actuator are hydraulic cylinders. The durability test apparatus according to any one of claims 1 to 3,
The durability test apparatus in which the actuator in the specimen is a motor.

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