JP3751566B2 - Metal material impact torsion tester - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shock torsion testing machine metallic materials, in particular, to a technique effective in assessing the impact torsion of the steel material for the drive shaft of an automobile or the like.
[0002]
[Prior art]
It is necessary to grasp in advance various characteristics (strength, twist, elongation, etc.) of the metal material according to its use. For this reason, various test methods such as a tensile test, a compression test, a torsion test, and an impact test have been defined, and many testing machines have been developed and put into practical use.
[0003]
By the way, all vehicles, such as a motor vehicle, are provided with the drive shaft which consists of steel materials in order to rotate and drive the wheel. Therefore, the superiority or inferiority of the drive shaft is an important point in the performance evaluation of these vehicles. This is because it is one of the most important parts for the vehicle. Conventionally, the steel material used for manufacturing the drive shaft is measured only with a material whose measuring value has passed the standard by using an existing material testing machine. In recent years, from the viewpoint of reducing fuel consumption of automobiles and the like, it has been directed to hollow the drive shaft.
[0004]
However, when an automobile or the like starts suddenly, a large impact torsion is applied to the drive shaft, but even though current material testing machines measure torsion and impact individually, the impact and torsion act simultaneously. There is nothing to evaluate when to do it. In general, the material test may occur when the test piece is considerably smaller than the actual product and the actual property estimated from the measurement result does not match the actual property.
[0005]
[Problems to be solved by the invention]
In view of such circumstances, not only can evaluate resistance to impact and twisting simultaneously acts on the metal material, that is tested in real scale to provide a test machine Ri torsional shocks allow metallic materials It is aimed.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the inventor conducted intensive studies with reference to various conventional testing machines, and realized the results in the present invention.
[0008]
That is, the present invention is connected to a fixed block having a splined coupling into which one end of a test piece is fitted, and to the fixed block so as to be spaced apart and connected to a coupling with a spline into which the other end of the test piece is fitted. A rotatable coupling, a torsion imparting shaft connected to the rotatable coupling, two bearings that are spaced apart from each other to support the torsion imparting shaft, and the torsion imparting shaft between these bearings. A metal material impact torsion tester comprising: a receiving arm having a flat surface whose receiving surface is separated from an axis; and an impact applying means for applying an impact to the flat surface. In this case, the impact applying means is formed by a pusher rod whose tip pushes the flat surface of the receiving arm and a hydraulic cylinder that applies an instantaneous impact to the rear end of the pusher rod, or the impact applying means The means includes a pendulum type hammer, a rotating shaft that supports the rear end of the hammer, a driving means that rotates the rotating shaft and lifts the tip of the hammer, and a clutch that disconnects the driving means and the rotating shaft. It is preferable to form by. The testing machine is preferably applied to steel materials.
[0009]
According to the present invention, the impact torsion of a metal material can be measured with a full-size test piece corresponding to the application. As a result, the present invention can be expected to greatly contribute to the development of hollow drive shafts for vehicles and the like.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0011]
First, the inventor studied means for twisting the test piece, decided to fix one end of the test piece and rotate the other end. And the structure of the holding part of a test piece as shown in FIG. 2 was considered.
[0012]
It is provided with a fixing block 2 which is bolted on a base 1, and a splined coupling 3 is attached thereto with the shaft horizontal. Here, the splined coupling 3 is a member in which a large number of concave grooves extending in the longitudinal direction along the circumference are formed on the inner surface of the cylindrical body. Accordingly, when the cross section of the test piece 4 is made circular and a large number of convex protrusions extending in the longitudinal direction are provided on the surface of one end of the test piece 4 so as to fit into the concave groove, the protrusions are simply inserted into the concave grooves. Thus, the test piece 4 can be supported.
[0013]
On the other hand, the other end of the sample needs to be rotatably supported. In order to fit the other end of the test piece 4, the inventor then provides another splined coupling 3 as described above and supports the splined coupling 3 with another rotatable coupling 5. I made it. The coupling 5 is attached to one end of a rotatable shaft (hereinafter referred to as a torsion imparting shaft 7) supported by two bearings 6.
[0014]
In the present invention, since the portion held by the test piece 4 has such a configuration, when the torsion imparting shaft 7 is rotated for some reason, the test piece 4 is given a rotational force to the other end with one end fixed. The torsion occurs around the axis.
[0015]
According to the object of the invention, the torsion needs to be shocking. For this reason, the inventor has studied to rotate the torsion imparting shaft 7 in an impact manner and decided to adopt the following impact imparting means.
[0016]
As shown in FIG. 3, a rod body (hereinafter referred to as a pusher rod 8) that pushes a part of the torsion imparting shaft 7 at its tip, and a momentary impact is applied to the rear end of the pusher rod 8. It is formed with a hydraulic cylinder 9. However, even if a part of the torsion imparting shaft 7 is simply impacted by such impact imparting means, the torsion imparting shaft 7 does not always rotate stably. This is because there is a possibility that the torsion imparting shaft 7 is bent although it may rotate depending on the pressed position. Therefore, the inventor has devised a twist-applying shaft 7 that is pushed by the tip of the pusher rod 8 so that a position as far as possible in the radial direction from the center of the shaft 7 can be pushed from the viewpoint of rotational moment. That is, as shown in FIG. 2, a part of the torsion imparting shaft 7 corresponding to between the two bearings 6 is configured as an impact receiving arm 10. The receiving arm 10 is made of a pillar, and a part thereof is cut away to form a flat surface 11 as shown in FIG. As a result, the tip of the pusher rod 8 can stably push the position (symbol A) away from the shaft 12 of the receiving arm 10 on the flat surface 11 and the torsion imparting shaft 7 is bent. Without failing to rotate reliably.
[0017]
The inventor has completed the above-described means and completed the impact torsion tester according to the present invention shown in a plan view in FIG.
[0018]
Furthermore, in the present invention, another form of impact applying means has been considered. It focuses on the so-called Charpy tester used to measure the impact fracture resistance of metal materials. That is, as shown in FIG. 4, the impact is applied by a pendulum type hammer 13. In this case, in order to drive the hammer 13, a rotating shaft 14 that supports the rear end of the hammer 13, and a driving means 15 that rotates the rotating shaft 14 as shown in FIG. The clutch 16 for disconnecting the connection between the driving means 15 and the rotary shaft 14 is required. Even if this pendulum type hammer 13 is used, as in the case of the hydraulic type pusher rod 8, an impact can be reliably applied to a predetermined position of the flat surface 11 of the receiving arm 10, and the torsional property of the metal material can be achieved. Can be measured.
[0019]
In addition, the metal material which is a test object of this invention does not necessarily need to be restricted to a steel material. This is because aluminum, copper, and other various alloy materials can be tested in the same manner as in the case of steel materials. Further, in the present invention, the position of the fixed block 2 is moved in the horizontal direction so that the measurement with the large test piece 4 can be performed, and the position of the rotatable coupling 3 with the spline and the fixed block 2 can be measured. It is also possible to change the gap with the position of the fixed splined coupling 3 attached to. That is, a large number of bolt holes 17 for fixing the fixed block 2 to the base are arranged in the horizontal direction as shown in FIG.
[0020]
Next, a method of actually measuring the impact torsion property of a test piece using such an impact torsion tester will be described.
[0021]
First, the test piece 4 is set in a test machine, and as shown in FIGS. 2 and 4, a strain gauge 18 for detecting the strain of the test piece 4 is attached to the test piece 4 and the torsion imparting shaft 7, and an impact load is applied. Is attached to the pusher rod 8 or the hammer 13. Although not shown, a strain meter, a data recorder, and the like for recording measurement data are installed in addition to a laser distance meter and a tachometer or a torque meter for measuring the speed. Further, the receiving arm positioning bracket 20 shown in FIG. Then, when the hydraulic cylinder 9 is driven or the hammer 13 is lifted and dropped, an impact is applied to the flat surface 11 of the receiving arm 10 to instantaneously destroy the test piece 4. In the meantime, since the strain change of the test piece 4 is recorded in the data recorder, the data is later organized and the so-called impact toughness is evaluated by the energy equivalent to absorption (torque × strain area) absorbed by the test piece 4. When the hydraulic cylinder 9 is used, coarse adjustment is performed by idle operation so that the required speed is obtained in advance, the strain rate is confirmed with a strain-time chart of actual measurement, and the pusher rod is checked with a laser distance meter. The speed of the cylinder 9 is finely adjusted by changing the hydraulic speed adjustment valve while checking the speed of the cylinder.
[0022]
【Example】
A test with a length of 150 mm from a steel pipe (outside diameter 35 mmφ × wall thickness 8 mm) and a cylindrical steel material (outside diameter 35 mm) having a tensile strength of 1470 MPa and containing 0.3 to 0.45 mass% of annealed C. Piece 4 was collected. And the convex protrusion was processed so that it might fit in the said spline coupling 3 on the surface of both ends, and it used for the impact torsion test which concerns on this invention. The used testing machine applies the impact shown in FIGS.
[0023]
When the obtained data such as strain and torque (see FIG. 6) were arranged, the curve shown in FIG. 7 was obtained. From FIG. 7, it is clear that the area surrounded by these curves and the horizontal axis, that is, the absorbed energy when an impact torsion is applied to the test piece is easily obtained. In addition, when the outer diameter is the same, it has been said that the torsion is more affected by the surface layer than the center of the steel material. Therefore, the results of FIG. 7 show that the impact torsion tester according to the present invention is appropriate. It proves that
[0024]
Thus, according to the present invention, it is possible to easily evaluate the impact torsion of a metal material, which has been impossible until now.
[0025]
【The invention's effect】
As described above, according to the present invention, it is possible not only to evaluate the resistance against impact and torsion acting simultaneously on the metal material, but also to perform an impact torsion test on a real scale. As a result, the present invention can be expected to greatly contribute to the development of hollow drive shafts for vehicles and the like.
[Brief description of the drawings]
FIG. 1 is a plan view showing the entirety of an impact torsion tester for a metal material according to the present invention.
FIG. 2 is a view taken in the direction of arrows AA in FIG.
FIG. 3 is a view taken along arrow BB in FIG. 1;
FIG. 4 is a cross-sectional view showing an impact applying means using a pendulum type hammer.
FIG. 5 is a view taken along the line CC in FIG. 4;
FIG. 6 is a diagram showing an example of data obtained by the implementation of the present invention.
FIG. 7 is a diagram showing a relationship for evaluating the absorbed energy of a test piece obtained by carrying out the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base 2 Fixed block 3 Coupling with spline 4 Test piece 5 Coupling 6 Bearing 7 Torsion imparting shaft 8 Rod (Pusher rod)
9 Hydraulic cylinder 10 Receiving arm 11 Flat surface 12 Receiving arm shaft 13 Hammer 14 Rotating shaft 15 Driving means 16 Clutch 17 Bolt hole 18 Strain gauge 19 Load cell 20 Receiving arm positioning bracket 21 Laser distance meter

Claims (3)

A fixed block provided with a splined coupling for fitting one end of the test piece, and a rotatable coupling connected to the coupling with the spline for fitting the other end of the test piece spaced apart and opposed to the fixed block; A torsion imparting shaft connected to the rotatable coupling; two bearings spaced apart from each other that support the torsion imparting shaft; and the torsion imparting shaft between the bearings, and a surface that receives an impact from the shaft center A metal material impact torsion tester comprising: a receiving arm having a flat surface that is spaced apart; and an impact applying means that applies an impact to the flat surface. The impact applying means is formed by a pusher rod whose front end pushes the flat surface of the receiving arm, and a hydraulic cylinder that applies a momentary impact to the rear end of the pusher rod. The impact torsion tester for metal materials according to 1. The impact applying means includes a pendulum type hammer, a rotating shaft that supports the rear end of the hammer, a driving means that rotates the rotating shaft and lifts the tip of the hammer, and a connection between the driving means and the rotating shaft. The impact torsion tester for a metal material according to claim 1, wherein the impact torsion tester is a metal clutch.

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