JPH0618269Y2 - Gauge displacement measuring device of material testing machine - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention mainly relates to a device for measuring the displacement between marked lines in a tensile test of a plate-like material having a relatively large elongation, such as metal or plastic. .

(Prior Art) When performing a tensile test on a test piece, an inter-mark line displacement measuring device having a pair of arms and a detector such as a differential transformer is generally used. Usually, this displacement measuring device has one end of each arm engaged with a test piece, and a detector is mounted between the other ends of the arms. Further, each arm is connected so as to be relatively swingable at a position between both ends of the arm. Therefore, when the test piece is deformed, each arm relatively swings following the deformation, and the relative displacement amount of each arm is detected by the detector. Therefore, the displacement amount between the marked lines of the test piece can be taken out by each arm and measured by the detector.

However, the following drawbacks exist when measuring relatively large displacements.

(1) Since the linear displacement of the test piece is detected as the displacement of the circular arc movement, the measurement accuracy is lowered.

(2) The swingable connection of the arms generally swings through a sphere to reduce the motion resistance, and swings around the contact portion between the spherical surface and the arm as a fulcrum. Move the sphere.

That is, since the fulcrum of the arm moves, the swing displacement at both ends of the arm does not have a fixed proportional relationship, and the measurement accuracy decreases.

(3) In the configuration as described in (2) above, since it is necessary to secure a swingable connection between the arms with an elastic body, the elasticity affects the tensile load measurement and reduces the load measurement accuracy.

(4) In addition, the even number of pins or the like causes backlash, which leads to a decrease in measurement accuracy.

(Technical problem) Therefore, the present invention has been made in view of the drawbacks of the conventional technology. (A) The displacement of the test piece is detected as a linear displacement, and (b) the fulcrum position of the arm swings. It is a technical subject to improve the measurement accuracy by (c) reducing the motion resistance and eliminating backlash by configuring so as not to be affected by movement.

(Technical Means) In order to solve the above-mentioned technical problems, the present invention (1) provides a fulcrum at four positions to linearly move a differential transformer as a detector to detect linear displacement. It is designed to be done.

(2) Further, a knife edge is used for the fulcrum to fix the fulcrum position, thereby reducing the motion resistance and eliminating backlash.

(3) Further, the fulcrum has a double knife edge structure, and the pressing structure by the elastic body between arms is unnecessary.

The contents of the present invention will be described below.

Reference numeral 1 is a main body of a plate-shaped sample piece S for measuring the displacement between gauge lines for a tensile test, and a relative declination oscillation between an upper displacement measurement arm 2A and a lower displacement measurement arm 2B provided in a pair in the upper and lower directions. Based on the above, the relative displacement amount between the marked lines (P, Q) of the sample piece S is measured. Reference numerals 3A to 3B are upper sample holding arms to lower sample holding arms which constitute the both displacement measuring arms (2A, 2B), and the base end portions (30A, 30B) of the upper base holding arm 4A and the lower base holding arm 4B. Groove (5) formed at the tip of
(A, 5B) and then mounted and installed, a pair of upper and lower side plates (6A,
6B), it is fixed by screwing 8 via the coil spring 7. Reference numerals 9A and 9B denote clamping members attached to the tips of the pair of upper and lower sample clamping arms (3A, 3B), and the distal end clamping portions R of both sample clamping arms (3A, 3B) are formed in a double-sided taper shape, The mounting rod 10A is fixed to the rear side of the mounting rod 10A, and the sandwiching side plate 12 having the lateral side semi-circular sandwiching receiver 11 is loosely fitted to the rear side of the mounting rod 10A via the knob rod 10B. 3B) is slidably mounted, and the tip holding portion R of the sample holding arm (3A, 3B) and the holding receiver 11 are arranged to face each other. On the other hand, a coil spring 13 is urged to intervene between the attachment rod 10A and the knob rod 10B of the holding side plate 12 so that the holding receiver 11 is constantly pressed to the tip holding portion R side (arrow B direction). It's done. Thus, the knob rod 10B is resisted against the expanding elastic force of the coil spring 13 in the arrow A direction between the tip holding portion R and the holding receiver 11 of the pair of upper and lower sample holding arms (3A, 3B). After the gripping rod 10B is released after the sandwiching portion of the sample piece S is sandwiched by forming a gap by moving the sample piece S, the sandwiching side plate 12 moves in the direction of the arrow B to easily sandwich the sample piece S. It can be fixed. Reference numeral 14 is a support frame member for supporting and fixing the tip ends of the upper base arm 4A and the lower base arm 4B, respectively. The support frame member 14 includes a double knife edge mechanism 15 and a pair of upper and lower base arms ( 4A, 4
It is incorporated into B), and its concrete structure is as follows as shown in FIG.

Reference numeral 16 denotes a saucer-shaped intermediate receiving member, which has an edge receiving member 16A formed substantially in the center of its inner surface and a pair of left and right edges 16B formed on its side surfaces. (4A, 4B)
The screw 17 is fixed to the tip of the. Further, the groove line 160 of the edge receiver 16A formed on the intermediate receiving member 16
A and the edge line 16 of the edge 16B provided on the pair of side surfaces
It is positioned on the same axis C as 0B (see FIG. 5), and the base arm (4A, 4B) can be smoothly rotated with the fulcrum as a fulcrum. 14A is a pin protruding from the support frame member 14 and is loosely fitted in a vertical guide groove 14B formed in the immovable frame body 140 so that the entire support frame member 14 can be moved in the vertical direction. is there.

Reference numeral 18 is a receiving member having a pair of edge receivers 18A for receiving the edge 16B, which is screwed 19 to the support frame member 14 and fixed.

Reference numeral 20 denotes a wedge-shaped edge 2 which is formed in a substantially T-shape and is pressed against the edge receiver 16A of the intermediate receiving member 16.
0A, which is a knife edge member, is fixed to the support frame member 14 by a screw 21 via a coil spring 20B, so that a pair of upper and lower base arms (4A, 4B) via the intermediate receiving member 16, that is, The upper displacement measuring arm 2A and the lower displacement measuring arm 2B are edge 16
B and the edge receiver 18A have a common fulcrum around which they can swing. Reference numeral 22 is an upper support member that supports the end portion 40A of the upper base arm 4A by a double knife edge mechanism portion 15A having the same structure as described above so as to be swingable in a declination angle. On the flange 23A, a ridge portion 24A which is a component of the linear bearing 24 is formed along the vertical direction, and an iron core 25A which is a component of the differential transformer 25 is projected in parallel to the longitudinal direction of the ridge portion 24A. Then installed. Reference numeral 26 is a lower support member that supports the end portion 40B of the lower base arm 4B by the double knife edge mechanism portion 15A as described above so as to be rotatable by a declination angle. The guide groove 24B is formed so as to be loosely fitted to the convex portion 24A to form the linear bearing 24, and the insertion hole 2 parallel to the guide groove 24B is formed.
The differential transformer 25 is formed by forming the coil 25B having 5C and inserting the iron core 25A of the upper flange 23A into and out of the insertion hole 25C. L is a sample piece S and a double knife edge mechanism section 1
5 and l represents the distance between the double knife edge mechanism 15 and the differential transformer 25, and in this embodiment, L> l. By adopting this L> l and two pairs of double knife edge mechanism parts (15, 15A), it is possible to suppress the arc movement of the pair of upper and lower displacement measurement arms (2A, 2B) as much as possible, and the marked line (P) of the sample S (P , Q) is accurately measured by the differential transformer 25. Reference numeral 27 is a linear bearing formed so as to be connected between a substantially central portion of the support frame member 14 and a tubular body 29 slidably attached to the guide rod 28 in the vertical direction.
The ridge 27A, which is a component of the linear bearing 27, is attached to the cylindrical body 2
9, a guide groove 27, which is a component of the linear bearing 27 that is protruded from the support frame member 14 at a substantially central position.
The ridge 27A is slidably fitted and slidably fitted on B. Thus, the inter-mark line displacement measuring device main body 1 is configured to move in parallel in the directions of arrows D to E via the linear bearing 27. Reference numeral 30 denotes a balance weight slidably attached to the lower portion of the guide rod 28. One end of a wire 31 is attached to the balance weight 30, and the wire 31 is attached to a pulley 32 attached to the upper end of the guide rod 28. After being half-wound, the other end of the wire 31 is fixed to the tubular body 29. The main-line displacement measuring device main body 1 is configured to move vertically along the guide rod 28 and the guide groove 14B of the immovable frame 140 while maintaining balance with the balance weight 30.

As a result, the sample piece S can be moved corresponding to the position. T is a tank greenhouse, which is a place where the sample piece S is tested, and the upper sample holding arm 3A and the lower sample holding arm 3B are inserted. H is an opening formed in the pair of upper and lower base arms (4A, 4B), and the guide rod 28 is penetrated through.

(Operation) The above technical means operates as follows.

For example, the sample piece S, which is a plate-shaped material, holds a sample (9
(A, 9B), first, the knob rod 10B attached to the holding side plate 12 of the holding member (9A, 9B).
Is pressed and moved in the direction of the arrow A, the sandwiching portion of the sample piece S is sandwiched in the gap between the sandwiching receiver 11 and the tip sandwiching portion R formed by this, and the knob rod 10B is released for one-touch operation. It can be clamped.

Further, when the main gauge displacement measuring device main body 1 is moved forward (direction of arrow D) or backward (direction of arrow E), the linear bearing 27 provided at the center of the support frame member 14 may be appropriately slid. good.

Then, when moving the gauge-rail displacement measuring apparatus main body 1 in the vertical direction along the guide rod 28, the balance weight 3
0 may be moved up and down along the guide rod 28, and the cylindrical body 29 linked by the wire 31 may be moved up and down while keeping a balance.

As described above, after the sample piece S is set in the gauge displacement measuring device main body 1 and the positioning is adjusted, when a tensile force is applied to the sample piece S in the arrow F or G direction, the sample piece S is deformed, The marked lines (P, Q) are displaced relative to each other, and the upper displacement measuring arm 2A and the lower displacement measuring arm 2B follow the axis of the double knife edge mechanism portion 15 of the support frame member 14 as a fulcrum. Then, it oscillates and deviates to deviate relatively. At that time, both displacement measurement arms (2A,
2B) by the displacement based on the relative swinging, the end portions (40A, 40B) of the pair of upper and lower base arms (4A, 4B).
The coil 25B of the differential transformer 25 provided in the above is integrally displaced with the lower base arm 4B, and the iron core 25A is integrally displaced with the upper base arm 4A.

Therefore, the relative displacement between the upper displacement measuring arm 2A and the lower displacement measuring arm 2B is detected by the relative displacement between the coil 25B and the iron core 25A.

Thus, the amount of displacement between the marked lines (P, Q) of the sample piece S can be measured by the differential transformer 25. The total length L of the pair of upper and lower sample holding arms (3A, 3B) is larger than the total length 1 of the pair of upper and lower base arms (4A, 4B).
The length of the base arm (4A, 4A
B) A pair of upper and lower support members (22, 2) for supporting the terminal portion.
For 6), the double knife edge mechanism portion 15A is adopted similarly to the support frame member 14, so that the pair of upper and lower displacement measuring arms (2A, 2B) support members (22, 2).
The large circular motion on the 6) side is suppressed as much as possible, and the displacement of the linear bearing 24 and the differential transformer 25 becomes a smooth linear motion, and the relative displacement amount between the marked lines (P, Q) of the sample piece S is accurately determined. Therefore, it is possible to improve the accuracy of measurement through the differential transformer 25.

(Effect) Therefore, the present invention has the following unique effects.

(A) In particular, two pairs of double knife edge mechanism parts (15, 15A) are used as fulcrums, and the distance L between the double knife edge mechanism part 15 and the sample piece S is determined by the distance l to the differential transformer 25. Since it is taken for a long time, the differential transformer 25 as a detector can be moved linearly,
Highly accurate measurement is possible.

In addition, with a simple knife edge mechanism, there is a lot of fear that the knife edge and its receiving part will separate, and if a separation prevention mechanism is added to prevent this, the resistance of the shaft support, which is the greatest feature of the knife edge, will increase. Although the advantage of being extremely small is impeded, in the present invention, by adopting the double knife edge mechanism part (15, 15A), it is possible not only to eliminate the possibility that the arm or the like will come off and fall out, but also its supporting resistance is extremely small. It is possible to take advantage of the advantage as it is and eliminate the disadvantages of the additional mechanism of the knife edge mechanism.The present invention is an epoch-making device that has never been seen as a gauge-to-mark displacement measuring device of a material testing machine. With the effect that can be achieved.

(B) In the prior art, since it was necessary to secure a swingable connection between the arms with an elastic body, the elasticity affected the tensile load measurement and lowered the load measurement accuracy. Can be eliminated.

(C) Further, in the prior art, there was backlash due to the even number of pins and the like, which led to a decrease in measurement accuracy, but the present invention does not have such a drawback.

[Brief description of drawings]

1 to 6 show an embodiment of the device of the present invention. FIG. 1 is a side view of a part of the device of the present invention, FIG. 2 is an overall plan view of the same, and FIG. FIG. 4 is an exploded perspective view showing an essential part of the double knife edge mechanism section, and FIG. 5 is a schematic explanatory view showing the operating principle of the double knife edge mechanism section. FIG. 6 is an overall perspective view of the device of the present invention. 2A: upper displacement measuring arm 2B: lower displacement measuring arm 3A: upper sample holding arm 3B: lower sample holding arm 4A: upper base arm 4B: lower base arm 14, 22, 26. Support member 25 ... Differential transformer 15 ... Double knife edge mechanism

Claims (1)

[Scope of utility model registration request] 1. A pair of upper and lower sample holding arms (3A, 3A)
B) is attached to the pair of upper and lower base arms (4A, 4B), respectively, and the pair of double knife edge mechanism portions 15 as fulcrums mounted on the support frame member 14 are incorporated into the pair of base arms (4A, 4B). The distance L between the double knife edge mechanism 15 and the sample piece S is set longer than the distance 1 between the double knife edge mechanism 15 and the differential transformer 25, and the differential transformer 25 is used as a pair of double knives as a fulcrum. Between the marked lines of the material testing machine, which is configured to move linearly via the upper support member 22 and the lower support member 26 having the edge mechanism portion 15A, and to measure the displacement amount of the marked line distance of the sample piece S. Displacement measuring device