JPH0345172Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial field of application) The present invention relates to a load constant torque mechanism for a rotating contact surface fatigue tester.

(Prior Art) FIGS. 4 and 5 show a conceptual diagram of a conventional rotating contact surface fatigue testing machine and a sectional view of its load torque mechanism.

In Fig. 4, 1 is a motor, 2 is a universal joint, 3 is a bearing, 4 is a driving side test piece, 5 is a driven side test piece, 6 is a driving side test piece mounting shaft, 7 is a driven side test piece mounting shaft, 8 is a coupling, 9 is a load torque shaft, 10 is a rotating disk, 11 is a friction block, 1
2 is a holder.

In a conventional rotating contact surface fatigue tester, the rotational force of the drive-side test piece mounting shaft 6 is applied to two disc-shaped test pieces 4 and 5.
is applied to the driven side test piece mounting shaft 7 by pressing the outer peripheral parts of the driven side test piece mounting shaft 7
By pressing a friction block 11 held by a holder 12 against the side surface of a rotating disk 10 fitted to a load torque shaft 9 connected via a coupling ring 8 to the surface of the two test specimens 4 and 5, The purpose is to apply surface pressure and rotational slip to the
However, as is clear from FIG. 5, in the conventional mechanism in which the friction block 11 is simply pressed against the rotating disk 10 via the coil spring 15 and the holder 12, the coefficient of friction depends on the rotational speed, temperature, and surface of the sliding surface. Since the frictional force varies depending on the condition, it has the disadvantage that it is not possible to maintain a constant and precise frictional force.

(Purpose of the invention) The present invention eliminates the above-mentioned drawbacks, and by adopting a mechanism in which the pressing force of the friction block increases or decreases in response to changes in the friction coefficient of the rotating disk, two parts are always maintained regardless of changes in the friction coefficient. The purpose is to apply a constant load torque to the contact surface of the test piece.

(Summary of the invention) A rotating disk fitted to a load torque shaft connected to a driven side test piece mounting shaft, a friction block that comes into contact with the side surface of the rotating disk to generate a frictional force, and a friction block that holds the friction block. a coil spring that receives the normal force of the friction block through the holder; the coil spring is supported by the holder and is mounted so as to be pressable by a screw mechanism to a pressing table fixed to a test table; In the load torque mechanism of a rotating contact surface fatigue tester, the load torque mechanism is composed of a threaded rod with a threaded rod, and the pressing force of the friction block is changed by moving the threaded rod, the tip of which is inserted between the holder and the coil spring seat. It has a long arm that guides and supports the holder in a slidable manner in the arm direction, and a short arm that is bent at a substantially right angle to the long arm, and the bent portion is rotatable about a support shaft fixed to the test table. The amount of movement of the friction block in the long arm direction of the L-shaped lever in response to the variation in frictional force due to the change in the friction coefficient between the friction block and the rotating disk is expressed as: The short arm is provided with a connecting rod that transmits transmission via a spring, and the moving direction of the friction block is changed to a direction perpendicular to the direction, thereby relating the friction force of the friction block and the pressing force of the friction block. This is to keep the load torque constant.

(Example) Examples of the present invention are shown below in Figures 1, 2, and 3.
This will be explained according to the diagram. FIG. 1 is a front sectional view showing the mechanism of the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 3 is a side view showing the mechanism of the present invention. 13 is an L-shaped lever, 14 is a spring seat, 15 is a coil spring, 1
6 is a threaded rod, 17 is a pressing base, 18, 24, 26 are nuts, 19 is a key, 20 is a connecting rod, 21 is a coil spring, 22, 23 is a spring seat, 25 is a support shaft, 2
7 is a test stand.

In FIGS. 2 and 3, the rotating disk 10 is rotating in the direction of the arrow. A threaded rod 1 is supported by a screw mechanism on a pressing table 17 fixed on a test table 27.
6, the friction block 11 held by the holder 12 is pressed against the side surface of the rotating disk 10 via the coil spring 15, the spring seat 14, and the long arm of the L-shaped lever 13, thereby generating a friction force. This frictional force varies depending on the friction coefficient and pressing force between the friction block 11 and the rotating disk 10, and the friction coefficient also varies depending on the sliding speed, temperature, and surface condition of the friction surface. Therefore, in order to keep the frictional force constant, a mechanism is provided in which even if the friction coefficient changes, the pressing force of the friction block 11 changes in response to the change. Friction block 11
is fixed to the holder 12, and the holder 12 is attached to the L-shaped lever 1.
3. It is attached so that it can slide freely in the direction of the long arm. Also, one end of the connecting rod 20 fixed to the holder 12 is connected to an L-shaped lever 1.
3 and is connected to the short arm of the L-shaped lever 13 so as to receive the tensile force due to the friction of the friction block 11 via the coil spring 21, spring seats 22, 23, and nut 24. Further, the curved portion of the L-shaped lever 13 is rotatably supported by a support shaft 25 fixed to the test stand 27.

In the mechanism of the present invention set as described above, the friction block 11 and the rotating disk 10 are
When the coefficient of friction between the L-shaped lever 13 and the holder 12 increases, the friction block 11 slides on the long arm of the L-shaped lever 13 so as to pull the connecting rod 20 together with the holder 12 in the tangential direction of rotation. At the same time, the L-shaped lever 13 connected to the connecting rod 20
As a result of the short arm of the lever being pulled through the coil spring 21, the L-shaped lever 13 attempts to rotate about the support shaft 25 in a direction that reduces the pressing force on the friction block 11, so the friction block 11 returns to its original position. The set frictional force is always maintained constant.

(Effects of the invention) As described above, according to the mechanism of the invention, a highly accurate constant torque can be applied in a rotating contact surface fatigue test. It is also mechanically simple and can be manufactured at low cost.

[Brief explanation of drawings]

Figure 1 is a front sectional view showing the mechanism of the present invention;
The figure is a sectional view taken along the line A-A in Figure 1, Figure 3 is a side view of Figure 1, Figure 4 is a conceptual diagram of a conventional rotating contact surface fatigue tester, and Figure 5 is the load torque mechanism of Figure 4. FIG. 4... Drive-side test piece, 5... Drive-side test piece, 6... Drive-side test piece mounting shaft, 7... Drive-side test piece mounting shaft, 9... Load torque shaft, 10... Rotating disk, 11 ... Friction block, 12 ... Holder, 13 ... L-shaped lever, 16 ... Threaded rod, 17 ...
...pressing stand, 20... connecting rod, 27... test stand.

Claims (1)

[Scope of utility model registration request] a rotating disk fitted to a load torque shaft connected to a driven side test piece mounting shaft; a friction block that comes into contact with a side surface of the rotating disk to generate a frictional force; and a holder that holds the friction block; a coil spring that receives the vertical force of the friction block via the holder; a threaded rod that supports the coil spring with the holder and is attached to a pressing table fixed to a test stand so that it can be pressed by a screw mechanism; In a load torque mechanism of a rotating contact surface fatigue testing machine that changes the pressing force of the friction block by moving the threaded rod, the tip is inserted between the holder and the coil spring seat, and the holder is connected to the arm. An L having a long arm that guides and supports the test piece so as to be slidable in the direction, and a short arm that is bent at a substantially right angle to the long arm, and whose bent portion is rotatably supported by a support shaft fixed to the test stand. The amount of movement of the friction block in the long arm direction of the L-shaped lever, which corresponds to fluctuations in frictional force due to changes in the coefficient of friction between the friction block and the rotating disk, is determined by applying a spring to the short arm of the L-shaped lever. and a connecting rod for transmitting the load torque through the friction block, and by converting the moving direction of the friction block to a direction perpendicular to the direction, the friction force of the friction block and the pressing force of the friction block are related to each other, and the load torque is A constant load torque mechanism for a rotating contact surface fatigue tester that attempts to maintain a constant value.