JPH04297850A - Hybrid material tester - Google Patents

Abstract

PURPOSE:To apply a load on a test piece by driving a cross head while a load is applied thereon by driving a load jig hydraulically. CONSTITUTION:This apparatus includes a cross head 4 which moves in a direction of a load shaft being guided to a pair of columns (2 or 3) erected on a base 1, a first load jig 7 set on the cross head 4, a second load jig 11 set on the base 1 facing the first load jig 7, a drive mechanism 9 which drives the cross head 4 to make the loads jigs 7 and 11 separate or approach, a hydraulic actuator 10 which drive the load jig 11 in the direction of the load shaft by hydraulic force to make the load jigs 7 and 11 separate or approach and locking means 12 and 13 for locking the load jig 11 to be driven with the hydraulic actuator 10. When a load is applied on a test piece with the driving of the cross head, the load jig 11 is locked with the locking means 12 and 13 to load the test piece TP with the moving of the cross head 4. In the hydraulic driving, the locking of the load jig 11 is released to apply a load on the test piece TP with the hydraulic actuator 10.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid material testing machine capable of loading test specimens over a wide range of applied loads and frequencies. Specifically, the present invention relates to a hybrid material testing machine that can load a test piece by driving a crosshead during a test with a small load and low frequency, and by hydraulically driving a loading jig during a test with a large load and high frequency.

0002

[Prior Art] Conventionally, a base, a pair of screw columns erected on the base, a crosshead that is horizontally suspended with both ends screwed to the pair of screw columns, and a crosshead installed on the crosshead. The first load jig that has been installed, a second load jig installed opposite to the first load jig, and a pair of screw columns are rotated to move the crosshead up and down. 1st and 2nd
A so-called screw-driven material testing machine is known, which is equipped with a drive mechanism that loads a test piece by moving a loading jig into and out of contact with the drive mechanism.

[0003] Also known is a material testing machine in which a test piece is loaded by a hydraulic actuator. A material testing machine, also known as a universal material testing machine, consists of a base, a pair of columns erected on the base, a crosshead supported at both ends by the pair of columns, and a crosshead. A first load jig installed in the first load jig, a second load jig installed opposite to this first load jig, and
and a hydraulic ram device for moving the second load jig into and out of contact with each other. Furthermore, as this type of hydraulic material testing machine, one in which the base is fixed and the first or second loading jig is driven by a double-acting hydraulic cylinder is also known.

[Problems to be Solved by the Invention] However, although screw-driven material testing machines can have a large stroke, they have a smaller load than universal material testing machines, and are not suitable for high-frequency vibration (fatigue) tests. be. On the other hand, hydraulically driven material testing machines such as universal material testing machines are suitable for applying large loads or high-frequency vibration tests, but are not suitable for small-load tests with short strokes or low-frequency tests. Not yet.

An object of the present invention is to provide a high performance hybrid materials testing machine that has the respective advantages of conventional screw-driven materials testing machines and hydraulically driven materials testing machines.

[0005]

[Means for Solving the Problems] The present invention will be explained in conjunction with FIG. 1 showing one embodiment. , 3), a crosshead 4 that moves in the load axis direction guided by a pair of pillars (2, 3), and a first crosshead installed on the crosshead 4.
a load jig 7, a second load jig 11 installed on the base 1 opposite to the first load jig 7, and a crosshead 4.
The first and second load jigs 7 are moved in the load axis direction.
. 10 and locking means 12 and 13 for locking the load jig 11 driven by the hydraulic actuator 10, the above object is achieved.

[0006]

[Function] When applying a load with the crosshead, the locking means 12
, 13, the load jig 11, that is, the hydraulic actuator 10
is locked, and the loading jig 7 is moved by the movement of the crosshead 4, thereby loading the test piece TP. Also,
During hydraulic drive, the loading jig 11, that is, the hydraulic actuator 10, is unlocked, and the hydraulic actuator 10 moves the loading jig 11, thereby loading the test piece TP.

[0007] In the section of the means and effects for solving the above-mentioned problems that explains the structure of the present invention, figures of embodiments are used to make the present invention easier to understand. It is not limited to.

[0008]

[Embodiment] An embodiment of the material testing machine according to the present invention will be explained with reference to FIGS. 1 to 4. The material testing machine shown in FIGS. 1 to 3 includes a base 1, a pair of screw columns 2 erected on the base 1, and a pair of columns 3 erected on the base 1. 4 is a crosshead, and as shown in FIGS. 1 and 2, a nut 4a
Both ends are screwed into a pair of threaded columns 2 via the screw columns 2, and horizontally suspended by a pair of columns 3 so as to be grippable by a hydraulic locking mechanism 5. The hydraulic locking mechanism 5 has a well-known structure, and uses the expansion and contraction force of the hydraulic cylinder 51 to tighten and release the half-split crosshead end via the fastening rod 52. A first load jig 7 is attached to the crosshead 4 at a load axis position via a load cell 6A and a universal join 6B. In this embodiment, the first loading jig 7 is a hydraulic grip. The upper ends of the pair of screw columns 2 and the pair of columns 3 are supported by a cross yoke 8.

[0009] The base 1 is provided with a drive mechanism 9 for the screw column 2. As shown in FIG. 3, this drive mechanism 9 includes a servo motor 91, a belt 92 that transmits the rotational force of the servo motor 91, a worm shaft 93 that is rotationally driven by the belt 92, and a worm shaft 93 that is fixed to the lower end of the screw column 2. Worm shaft 93
and a worm gear 94 that meshes with the worm gear 94.

The base 1 is also provided with a double-acting hydraulic cylinder 10 coaxially with the load axis, and a piston rod of the hydraulic cylinder 10 is provided with a first load jig 7 and a second load jig opposing the load jig 7. 11 are provided. In this embodiment, the second loading jig 11 is a hydraulic grip. A flange 12 is fixed to the piston rod, and this flange 12 is connected to a bolt 13.
It can be fixed to the base 1 by. 14 is a servo valve provided in the hydraulic cylinder 11.

A hydraulic power source 20 supplies pressure oil to the locking hydraulic cylinder 51, the opening/closing cylinders of the first and second load jigs 7 and 12, and the servo valve 14 via a switching valve group 21. .

FIG. 4 shows a control block for driving and controlling the servo motor 91 and the servo valve 14. As shown in FIG. Reference numeral 71 denotes a reference signal generating section, which outputs a signal in accordance with the load pattern applied to the test piece TP. For example, a sine wave signal is output during a fatigue test. 72 is a servo amplifier; 73 and 74 are changeover switches that operate in conjunction; the changeover switch 73 selects the feedback signal from the servo motor 91 or the feedback signal from the servo valve 14 and feeds it back to the servo amplifier 72; In addition, the changeover switch 74
is the output signal of the servo amplifier 72 to the servo motor drive unit 7
5 or to the servo valve drive unit 76.

[0013] The operating procedure of such a material testing machine will be explained. (1) When testing with a screw drive method (small load, low frequency test) The flange 12 is fixed to the base 1 with bolts 13, and the hydraulic cylinder 10 is mechanically locked. On the other hand, the locking mechanism 5 of the crosshead 4 is in an inoperative state, and the crosshead 4 is
is made to be able to slide on the support column 3. The height position of the crosshead 4 is determined according to the length of the test piece TP, and the opening/closing cylinders of the upper and lower grips 7, 11 are controlled by the switching valve group 21 to open the grips 7, 11. Both ends of the test piece TP are inserted between the upper and lower grips 7 and 12, and the switching valve group 21 is operated to close these grips 7 and 11 to grip the test piece TP.

A reference signal corresponding to the load pattern is set in the reference signal setting section 71 from an operation panel (not shown), and the changeover switches 73 and 74 are switched to the motor side. When the test start is commanded, the reference signal output from the reference signal generating section 71 is inputted to the servo motor driving section 75 via the servo amplifier 72 and the changeover switch 74. Servo amplifier 72
A feedback signal from the servo motor 91 is fed back to the servo amplifier 72, and the servo amplifier 72 outputs a drive command signal according to the reference signal and the feedback signal indicating the drive state of the servo motor 91. As a result, the servo motor 91 drives the screw column 2, that is, the crosshead 4, so as to load the test piece TP in a predetermined load pattern. At this time, since the lower grip 11 is fixed to the base 1 by the flange 12, a load corresponding to the movement of the crosshead 4 is applied to the test piece TP. Note that a test piece TP may be placed between the cross yoke 8 and the cross head 4 for testing.

(2) When testing using a hydraulic drive system (large load, high frequency test) The bolts 13 are removed, the flange 12 is separated from the base 1, and the hydraulic cylinder 10 is freed. On the other hand, with the locking mechanism 5 of the crosshead 4 left inactive, the height position of the crosshead 4 is adjusted according to the length of the test piece TP, and the locking mechanism 5 is activated to support both ends of the crosshead 4. Tighten to 3. In this state, both ends of the test piece TP are gripped with the upper and lower grips 7 and 11 in the same manner as described above.

As described above, a reference signal corresponding to the load pattern is set in the reference signal setting section 71, and the changeover switches 73 and 74 are switched to the valve side. When a command to start the test is given, the reference signal output from the reference signal generating section 71 is inputted to the servo valve driving section 76 via the servo amplifier 72 and the changeover switch 74. Servo valve 1 is installed in servo amplifier 72.
The servo amplifier 72 outputs a drive command signal according to the reference signal and the feedback signal indicating the drive state of the servo valve 14 . As a result, the servo valve 14 drives the double-acting hydraulic cylinder 10, that is, the lower grip 11, so as to load the test piece TP in a predetermined load pattern. At this time, since the crosshead 4 is tightened to the support 3,
A load corresponding to the movement of the lower grip 11 acts on the test piece TP.

As described above, according to this embodiment, when the load is small (for example, 5 kg) and the frequency is low (for example, 10-6 Hz),
During the test, the test piece TP is loaded using a screw drive method, and is subjected to a large load (for example, 100 tons) and a high frequency (for example, 100H).
z) During the test, the test piece TP was loaded using a hydraulic drive system, making it possible to test with a single material testing machine over a much wider load range and frequency range than in the past.

Furthermore, if the circuit configuration is as shown in FIG. 4, only one servo amplifier 72 is required, resulting in a simple configuration. Of course, a servo amplifier may be provided for each of the servo motor and the servo valve. With this configuration, the test piece TP can be loaded with screw drive and hydraulic drive at the same time, allowing dynamic and static tests. This has the advantage of being able to obtain analysis data for simultaneous analysis.

Furthermore, according to the configuration of this embodiment, the screw column 2 can have a diameter that can withstand the maximum load when a test piece is loaded by screw drive, and the column 3 can have a diameter that can withstand the maximum load of the hydraulic actuator 10. , the diameter of the screw column 3 can be reduced, which is advantageous in terms of cost. In addition, since a single material testing machine can perform tests over a wide range of loads and frequencies, which conventionally required two material testing machines, the unit price of one machine is lower than that of a conventional material testing machine for low-load, low-frequency testing. Even if it is more expensive than a material testing machine for high-load, high-frequency testing, it is cheaper than the cost of two machines.

Note that the hydraulic cylinder 10 is connected to the crosshead 4.
The piston rod of the hydraulic cylinder 10 may be fastened to the crosshead 4 and locked when the screw is driven. Further, although the hydraulic cylinder 10 is mechanically locked, it may be hydraulically locked, and the mechanical locking mechanism is not limited to the illustrated example. Furthermore, the hydraulic cylinder 10 may be of a single-acting type.

[0021] The movement mechanism for the crosshead 4 is not limited to the one shown, and various configurations can be adopted. For example, the screw column 2 may be made unrotatable, and the nut 4a may be rotated by a drive mechanism provided within the crosshead 4. Alternatively, the crosshead 4 may be raised and lowered by using the crosshead 4. Alternatively, a method may be adopted in which the screw column 2 is omitted, the cross head 4 is made movable up and down along the column 3, and the cross head 4 is raised and lowered using a wire rope or the like. In this case, the hydraulic locking mechanism 5 is essential.

[0022] The loading jig is not limited to the gripping jig used in the embodiment, but may also be a platen for compression testing, a jig for three-point bending, or the like. Furthermore, the crosshead support 3 is equipped with a hydraulic lock mechanism 5 during hydraulic drive.
However, when using the screw column 2, this hydraulic locking mechanism 5 is not necessarily required.

[0023]

Effects of the Invention As explained in detail above, according to the present invention, when testing with a small load and low frequency, the crosshead is driven to apply a load to the test piece, and when testing with a large load and high frequency, the load is applied to the test piece. Since the loading jig is driven by pressure to apply a load to the test piece, a single material testing machine can test a wide range of loads and frequencies with high accuracy.

[Brief explanation of drawings]

[Fig. 1] A front view showing one embodiment of a material testing machine according to the present invention.

[Figure 2] Cross-sectional view taken along line II-II in Figure 1

[Figure 3] Cross-sectional view taken along the line III-III in Figure 1

[Figure 4] Control block diagram of Figure 1

[Explanation of symbols]

1 Base 2 Screw column 3. Support 4 Cross head 5 Hydraulic lock mechanism 7 Upper grip 9 Screw drive mechanism 10 Hydraulic cylinder 11 Lower grip 12 Flange 14 Servo valve 71 Reference signal generation section 72 Servo amplifier 73, 74 Selector switch 91 Servo motor

Claims (1)

[Claims] Claim 1: A base, at least a pair of columns erected on the base, a crosshead that moves in the load axis direction guided by the pair of columns, and a first crosshead installed on the crosshead. a load jig, a second load jig installed on a base opposite to the first load jig, and a first and second load jig by moving the crosshead in the load axis direction. a hydraulic actuator that drives the first or second load jig in the direction of the load axis using hydraulic pressure to move the first and second load jig toward and away from each other; A hybrid material testing machine characterized by comprising a locking means for locking a load jig.