JPH01118743A - Loading device for material testing machine - Google Patents

Abstract

PURPOSE:To improve the test accuracy by rotating a lever around an operation point with moment generated around the fulcrum of the lever, extending a 1st suspension body from an arcuate surface with a radius R, and winding a 2nd suspension body around the arcuate surface with the radius R. CONSTITUTION:A sample 54 is put in a cylinder 53 and pressure oil is discharged from the hydraulic chamber 56a of a lift jack 56, so that a large pulley 31, a couple of small pulleys 32, and a pin 33 rotate by the weight of a weight 35 as shown by an arrow B. This rotation winds a steel belt 37 around the pulleys 32, but a steel belt 36 is unwound from the pulleys 32 and the pulleys 31 and 32, pin 33, column 41, and plates 42a and 42b move down in one body, so a load shown by a specific expression is placed on a load shaft 51. This load is transmitted to the piston 53a of a cylinder 53 through a spherical seat 55 to press the sample 54, which is extruded from a nozzle 53b. The current stroke quantity of the load shaft 51 is detected by a stroke detector 57 and data on the flowability, etc., of the sample 54 is found from the lowering speed.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a loading device for a constant load type flow tester or creep tester for measuring flow properties, viscosity, etc. of resins, foods, etc.

B. Prior art This type of conventional loading device has, for example, a weight suspended from the tip of a lever that is swingably provided around a fulcrum.
The lever is rotated by this weight, and the plunger connected to the fulcrum side of the lever is moved only in the vertical direction to press the sample. In such a loading device, since the load is obtained using the circular arc motion of the tip of the lever, there is a problem in that the weight causes horizontal oscillation and the applied load is not constant.

Therefore, the present applicant previously proposed a load device shown in FIG.

In FIG. 4, a plunger 4 is connected at a point of action 3 to a lever 2 that is swingable about a fulcrum 1. As shown in FIG. Since the fulcrum 1 is movable in the horizontal direction by the rotation of the rolling element 5, the plunger 4 is guided by the guide 14 by the swinging of the lever 2 and can move linearly in the vertical (vertical) direction. The sample 7 in the cylinder 6 is pressed by the plunger 4. One end of a belt 9 is attached to a power point 8 at the tip of the lever 2, and the other end of the belt 9 is wound around a small pulley 11a that is rotatable around a fixed horizontal shaft 1o. In addition, a small pulley ll is rotated around the horizontal axis 10.
One end of a belt 12 is wound around a large pulley llb that can rotate together with the belt a, and a weight 13 is connected to the other end.

When the test is started with the swinging motion of lever 2 free,
The weight 13 descends and the pulley llb rotates in the six directions shown. As a result, the pulley lla also rotates in the same direction, so that the belt 9 is wound around the pulley 11a, and the lever 2 rotates about the fulcrum 1. As a result, the plunger 4 descends vertically and the sample 7 is pressed. Since the horizontal axis 10 is fixed, the weight 13 moves only in the vertical direction, thus suppressing the lateral movement of the weight 13.

C0 Problems to be Solved by the Invention However, although fluctuations in the suppressing load due to the horizontal shaking of the weight 13 are eliminated, the line of action of the tension on the belt 9 is not vertical but is inclined, and as this angle of inclination increases, the suppressing load is reduced. Load fluctuates. In addition, there is a problem that the load accuracy is poor because the friction between the fulcrum 1 and the force point 8 is large.

SUMMARY OF THE INVENTION An object of the present invention is to provide a loading device for a material testing machine in which the applied load acting on a sample is always constant.

Means for Solving the D0 Problem The present invention provides a load shaft that vertically moves up and down to load a material, a lever connected to the load shaft through a point of action, and a lever connected to the load shaft through a force point at one end of the lever. This is carried out on the loading device of a material testing machine, which is equipped with a weight that is suspended by a lever and generates a moment around the fulcrum at the other end of the lever. The problem mentioned above is that one side of the lever centered on the point of action is an arcuate surface with a radius R centered on the point of action, and the other side is an arcuate surface with a radius r (<R) centered on the point of action. , one end of the first hanging body is wrapped in one direction around an arcuate surface of radius R, a weight is suspended from the other end, and one end of the second hanging body is wrapped around an arcuate surface of radius R in one direction. Wrap it in the opposite direction, and use the other end as a fixed end below the point of action.The moment causes the first hanging body to be drawn out from the arcuate surface of radius R, and the second hanging body to be rolled out from the arcuate surface of radius R. By rotating the lever around the point of application so that it is wrapped around an arcuate surface, and lowering the lever while positioning the point of action, the fulcrum, and the point of force on a horizontal straight line, and loading the sample through the load shaft. resolved.

The lever rotates around the point of action due to the moment generated around the fulcrum of the E0 action lever, the first suspension member is extended from the arcuate surface of radius R, and the second suspension member is extended from the arcuate surface of radius r. wrapped around. As a result, the lever is lowered while the point of action, the fulcrum, and the point of force are located on a horizontal straight line, and as a result, the sample is always loaded with a constant load via the load shaft.

F. Embodiment An embodiment in which the present invention is applied to a load device of a flow tester will be described based on FIGS. 1 and 2.

(I) Structure of Embodiment FIG. 1 is a principle diagram of a load device according to the present invention, and FIG. 2 is a perspective view showing the conceptual structure.

In FIG. 2, a pair of upper and lower plates 42a.

Both ends of the pin 33 are connected to the pair of support columns 41 connected by 42b. A load shaft 51 is connected to the lower end of the plate 42b, and a piston 5 is connected below the load shaft 51.
3a is fixed to a member not shown. As shown in FIG. 1, a sample 54 is inserted into this cylinder 53. The load shaft 51 contacts the piston 53a via a spherical seat 55 for preventing eccentric loads, and applies a load to the sample 54. In addition, in FIG. 1, 53b is a nozzle through which the sample flows out.

Further, the upper plate 42a is connected to a lifting jack 56 fixed to a member (not shown), and for example, when a test is not performed, a hydraulic chamber 56a of this lifting jack 56
Hydraulic pressure is supplied from a hydraulic source (not shown) to (FIG. 1), and this system is returned to and held at the initial position shown in FIG. In addition, in FIG. 1, S7 is a stroke detector that detects the stroke amount of the load shaft 51.

In FIG. 2, a large pulley 31 with a radius R and a pair of small pulleys 32 with a radius r integrated on both sides of the large pulley 31 are rotatably attached to the pin 33. Here, the large and small pulleys 31 and 32 constitute a lever, and each circumferential surface constitutes an arc surface. Large pulley 31 is made of steel! (first suspension body) 34 is wound around and one end 34a is attached to the large pulley 3
1, and a weight 35 is suspended from the other end. Therefore, a rotational moment is generated in the large pulley 31 due to the weight of the weight 35. Further, a steel band 36 is wound around the inner side of the rotating surface of the pair of small pulleys 32, and one end 36a of the steel band 36 is connected to each small pulley.

32, and the other end is fixed above the pin 33. Further, a steel band (second suspension member) 37 is wound around the outer side of the rotating surface of the small pulley 32, and one end 37a is fixed to each small pulley 32, and the other end is fixed below the pin 33. Now, due to the rotational moment due to the weight of the weight 35, the large pulley 31, small pulley 32. When the pin 33 rotates in the B direction (Fig. 1), the steel f37
On the other hand, since the steel strip 36 is unwound from the small pulley 32, the large and small pulleys 31 and 32 and the pin 33
moves downward. In addition, ll! The steel strip 3
4, 36, and 37 are wound, that is, the load shaft 51
The stroke amount is variable.

As shown in FIG. 1, the fulcrum of this system is the point C1 where the small pulley 32 and the steel strips 36, 37 come into contact with and separate from each other.The point of action is the load shaft 5.
The axis D of the pin 33 inserted into the column 41 connected to 1
, the point of effort is point E where the large pulley 31 and the steel strip 34 come into contact with each other. The fulcrum C2 and the point of effort E move as the large and small pulleys 31 and 32 and the pin 33 move up and down, but their positional relationship does not change and they are always located on the same horizontal line at regular intervals. do. Therefore, the large and small pulleys are 31°32
Let the radius of the pin 3 be R, r, and the weight of the weight 35 be W.
A load represented by ((R + r)/r)

(II) In the operation test of the embodiment, when the sample 54 was inserted into the cylinder 53 and the pressure oil in the hydraulic chamber 56a of the lifting jack 56 was drained, the weight of the weight 35 caused the large pulley 31. A pair of small pulleys 32 and pin 33 rotate in direction B in FIG. Due to this rotation, the steel strip 37 is wound around the small pulley 32, while the steel strip 36 is let out from the small pulley 32, so that the large and small pulleys 31, 32. Pin 33. Post 41. plate 4
2a and 42b are lowered together, and a load of equation (1) is applied to the load shaft 51. This load is transmitted to the piston 53a of the cylinder 53 via the spherical seat 55, and the sample 54 is pressed and extruded from the nozzle 53b. Load axis 5 at this time
The stroke amount of 1 is detected by the stroke detector 57,
Data such as the flowability of the sample 54 can be obtained from the descending speed.

According to the above configuration, the fulcrum C2, the point of application, and the point of effort E are always positioned on the same horizontal line at a constant interval and descend.
Equation (1) always holds true, and a constant load always acts on the sample 54, and there is no lateral movement of the weight 35, and no load fluctuation occurs due to it, improving test accuracy.

Note that the diameters of both pulleys 31 and 32 can be changed without changing the diameter ratio of the large pulley 31 and small pulley 32, and the copper strip 3
By increasing the winding length of 4, 36, and 37, the stroke can be increased under the same load.

(m) Modification In addition, instead of the large and small pulleys 31 and 32, as shown in FIG.
7 is wound, that is, the range determined by the required stroke of the load shaft 51.
73 may be used. According to this, the lever 71 is made smaller and lighter than a pulley type lever.

Furthermore, when the lifting jack 56 is provided along the axis of the load shaft 51, the upper steel band 36 may be omitted;
This is essential if the jack 56 deviates from this axis.

Furthermore, instead of the copper strips 34, 36, 37, flexible
A strong material such as wire or chain may also be used. Furthermore, although the flow tester has been described above, the present invention can also be implemented as a loading device for other material testing machines, such as a creep tester that measures the time-elongation characteristics of a test piece under a constant load.

G0 Effects of the Invention Since the present invention is constructed as described above, the point of action, fulcrum, and point of force are always located on the horizontal-straight line regardless of the movement of the system, and therefore the sample is always subjected to a constant load through the load axis. This increases the load, thereby improving test accuracy.

[Brief explanation of the drawing]

1 and 2 show one embodiment of the present invention;
2 is a perspective view showing the conceptual structure, and FIG. 3 is a diagram showing a modification of the lever. FIG. 4 is a front view showing a conventional load device. 31: Large pulley 32: Small pulley 33: Pins 34, 36, 37: Steel strip 35: Weight 51: Load shaft 53 Niji cylinder 54: Sample patent applicant Shimadzu Corporation Patent attorney Representative Fuyu Nagai Figure 1

Claims (1)

[Claims] A load shaft that lifts and lowers the material vertically to load the material, a lever that is connected to the load shaft through the point of action, and a moment that is suspended by the lever through the point of force at one end of the lever and around the fulcrum at the other end of the lever. In a loading device for a material testing machine equipped with a weight that causes is an arcuate surface with radius r (<R),
One end of a first suspension member is wound in one direction around an arcuate surface with a radius R, the weight is suspended from the other end, and one end of a second suspension member is wrapped around an arcuate surface with a radius R in one direction. The second end is wound in the opposite direction, and the other end is fixed below the point of application, and the moment causes the first hanging body to be drawn out from the arcuate surface of radius R, and the second hanging body to be wound in the opposite direction. A loading device for a material testing machine, characterized in that a fulcrum and a point of force are positioned on a horizontal straight line, and the specimen is lowered and loaded via a loading shaft so that the specimen is wound around an arcuate surface having a radius r.