JP2653137B2 - Screw driven material testing machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a screw-driven material testing machine used for tensile tests, compression tests, bending tests, and the like.

B. Prior Art As shown in FIG. 3, in a conventional screw-driven material testing machine, a cross head 4 is mounted on a screw rod 3 erected between a fixed table 1 and a cross yoke 2. Screwed,
Clamps 5, 6 between crosshead 4 and fixed table 1
Load the specimen through

During the test, not only the stroke required to load the test specimen (hereinafter referred to as the test stroke), but also the stroke for gripping the test specimen with the grips 5 and 6, the grips 5 and 6, and other treatments Strokes for attaching and detaching the tool are required, and all of these strokes are obtained by rotating the screw rod 3 and moving the crosshead 4 up and down. Therefore, the screw rod 3 of the conventional screw drive type material testing machine has a screw engraved on its entire length.

C. Problems to be Solved by the Invention Therefore, when the test stroke increases, the overall length of the screw rod 3 necessarily increases. In addition, when using a large jig such as a constant temperature test in which a constant temperature chamber is installed between the upper and lower gripping tools 5 and 6, even if the test stroke required to actually load the test specimen is short, An extra stroke is required for the height of the jig.
Becomes longer.

However, the overall length of the screw rod 3 has a limit in machining, and if it is longer, the accuracy is deteriorated and the cost is increased.

The technical problem of the present invention is that the screw is not carved according to the total lifting stroke of the crosshead required at the time of the test,
The aim is to raise and lower the crosshead by the required stroke with a screw at least as long as the test stroke.

D. Means for Solving the Problem The present invention will be described with reference to FIG. 1 showing an embodiment. The present invention comprises a pair of columns 15 provided on a fixed base 11 and rotated by driving means 19, A screw rod 24 that is a hollow cylinder that is shorter than the support 15 and has a thread engraved on the outer peripheral surface and is externally movably and non-rotatably inserted into the support 15 and a screw rod for the support 15
The above-mentioned technical problem is solved by providing a fixing means 25 for fixing the position of 24, and a crosshead 28 which is screwed with the screw rod 24 and is separated from and fixed to the fixed base 11 by rotation of the screw rod 24. Is done.

E. Action The fixing means 25 is loosened, and the position of the crosshead 28 is adjusted by moving the crosshead 28 together with the screw rod 24 along the column 15. After the positioning, the position of the screw rod 24 is fixed by the fixing means 25. When the support 15 is rotated by the driving means 19, the screw rod 24 also rotates, and the crosshead 28 moves. Therefore, it is not necessary to drive the crosshead 28 by screw driving when installing a jig or the like, and the length of the screw rod 24 can be reduced.

In the above sections D and E for describing the configuration of the present invention, the drawings of the embodiments are used for easy understanding of the present invention, but the present invention is not limited to the embodiments.

F. Embodiment An embodiment will be described with reference to FIG. 1 and FIG.

In FIG. 1, a fixed table 12 fixed to a base 11 is shown.
, A pair of machine frames 13 are erected, and a cross yoke 14 is horizontally mounted on the upper end. Between the fixed table 12 and the cross yoke 14, a pair of columns 15 are supported at both ends by bearings 16 and 17, and are rotatably provided upright. A gear 18 is provided at the lower end of the support 15, and rotational force is transmitted to the gear 18 via a motor 19, a gear box 20, an output gear 21, and a timing belt 22 installed in the base 11. Rotates.

A key 23 is provided on the column 15 over substantially the entire length thereof, and a key 23 is provided. As shown in FIG. Be transformed into The screw rod 24 is a hollow cylindrical rod having a short length corresponding to a test stroke necessary for loading the test piece TP, and a screw is engraved on an outer periphery thereof over the entire length, and a pair of upper and lower fixed collars 25 is formed. As shown in FIG. 2, the height position of the threaded rod 24 is fixed by being tightened to the column 15 with a bolt 26. The fixed collar 25 is integrally provided with a thrust bearing 27 so as to smoothly move up and down on the support 15 of the screw rod 24. The screw rod 24 is screwed with a nut 29 screwed to the crosshead 28.

An upper grip 30 is fixed to the crosshead 28 on a fixed table.
A lower grip 31 is attached to 12, and both grips 30, 31 are inserted into a thermostat 32 fixed by a frame (not shown), and the test piece TP is gripped in the thermostat 32. Also the crosshead
One end of a wire 33 is connected to 28, and the other end is wound around a pulley 34 provided on the cross yoke 14 and extends downward to suspend a balance weight 35. The weight of the balance weight 35 is determined so as to balance the weight of the crosshead 26, the upper grip 30, the load cell 37, the screw rod 24, and the like.

The operation of the material testing machine having such a configuration will be described.

Prior to the test, the bolt 26 of the fixed collar 25 is loosened and the screw rod 24 is moved up and down along the column 15 to position the crosshead 28. At this time, since the weights of the crosshead 28 and the associated devices are balanced with the balance weight 35, the position of the crosshead 28 can be easily adjusted manually. After fixing the fixing collar 25 to the support 15 with the bolt 26 and positioning the screw rod 24 to the support 15, the motor 15
The screw bar 24 is rotated through to adjust the height position of the crosshead 28, and the test piece TP is gripped by the upper and lower grippers 30, 31.

 This completes the test preparation.

When the motor 19 is started, its rotational force is
20, is transmitted to the gear 18 via the output gear 21 and the timing belt 22, and the column 15 rotates. As a result, the screw rod 24 also rotates, and the crosshead 28 rises or falls, and a tensile force or a compressive force acts on the test piece TP.

With such a configuration, when installing the constant temperature bath 32 or mounting the upper and lower grips 30 and 31, the screw rod 24 and the crosshead 28 that are screwed and integrated with each other along the support 15 The amount of elevation of the crosshead 28 by the screw rod 24 may be the amount of test stroke necessary to load the test piece TP. That is, since the screw rod 24 may have a length substantially corresponding to the test stroke, when using a large jig, it is only necessary to lengthen the column 15, and the stroke length is limited by the machining limit of the screw. Absent. Further, since the screw rod 24 is short, the accuracy can be maintained and the cost can be reduced.

Although the crosshead 28 is equilibrated with the balance weights and moved up and down manually, the movement of the screw rod 24 and the crosshead 28 may be performed by a cylinder device. Alternatively, the weight of the crosshead 28 or the like may be mechanically held by a method other than the balance weight method and moved manually or by a fluid or electric actuator. In addition, the screw 23 and the column 15 are stopped from rotating by the key 23, but a spline or a serration type may be used, provided that the screw bar 24 is unrotatably integrated so as to be movable along the column 15. For example, the configuration is not limited to the embodiment. The present invention can also be applied to a horizontal material testing machine.

G. Effects of the Invention Since the present invention is configured as described above, when the crosshead is moved by a predetermined amount at the time of installing a jig or the like, the screw rod may be slid along the column, and the screw drive may be used. Since it is not necessary to drive the crosshead, it is not necessary to machine a screw having a length longer than the test stroke, and cost can be reduced.

[Brief description of the drawings]

1 and 2 illustrate an embodiment of the present invention. FIG. 1 is a partially cutaway front view of a material testing machine, and FIG. 2 (a) is a cross section taken along line aa of FIG. FIG. 2 (b) shows the first
FIG. 3 is a front view of a conventional screw driven material testing machine. 11: Base, 12: Fixed table 15: Post, 19: Motor 23: Key, 24: Screw bar 25: Fixed collar, 28: Crosshead 29: Nut, 33: Wire 35: Balance weight

Claims (1)

(57) [Claims] 1. A pair of columns provided on a fixed base and rotated by a driving means, and a hollow cylinder shorter than the columns, wherein a screw is engraved on an outer peripheral surface and is movable on the columns and cannot rotate. A screw rod extrapolated and fixed to the support, fixing means for fixing the position of the screw rod with respect to the support, and a crosshead which engages with the screw rod and separates from the fixed base by rotation of the screw rod. A screw-driven material testing machine, comprising: