JPH09126969A - Load mounting apparatus for elastic test piece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to perform a highly accurate load mounting, which is stable from a low load region to a high-load region in actual use, by a constitution that a load mounting cylinder device to be separately provided is fixed to a double-action cylinder so that translation is possible, and the piston rod of the double-action cylinder is fixed to a base stage. SOLUTION: A load mounting cylinder 6 is fixed to the upper part of a double-action cylinder 7. A single rod cylinder is suitable for the cylinder 7. A piston rod 7p of the cylinder 7 is attached and fixed to a fixing stage 9 extending upward from a base stage 8. In this fixing, the acting direction of the cylinder 7, that is to say, the axial-center direction of the rod 7p and a straight line L are in parallel to each other. The cylinder 7 for the reciprocating role for a test piece 2 and the cylinder 6 only for the role of the load mounting of the test piece are separately provided, and the functions are separately executed. Therefore, the large volume is not required for the chambers of the respective cylinders 6 and 7. Thus, not only the caontrol of the moving speed of the test piece 2 but also the control of the mounting load become easy, and the mounting accuracy for the overall loads from the low load to the high load can be enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrying member for carrying an elastic body test piece, and a test starting position of the test piece with respect to the main body of the dynamic tester via the carrying member and a retracted position separated from the position. A double-acting cylinder that moves the test piece back and forth;
A load tester for elastic test pieces that has means for applying a load to the test piece against the main body of the dynamic tester, and in particular measures the dynamic friction characteristics and wear characteristics of elastic test pieces such as vulcanized rubber. A dynamic tester body that evaluates the fatigue resistance of an elastic body by repeatedly applying a variable load to a dynamic tester body, or a similar test piece, while applying a highly accurate load to an elastic body test piece such as vulcanized rubber. The present invention relates to a load applying device for an elastic body test piece, which is capable of applying a load and thereby obtaining an appropriate test result.

[0002]

2. Description of the Related Art An apparatus for measuring wear and fatigue of an elastic body using a dead weight, for example, a Lambourn wear tester as a dynamic tester for measuring the wear characteristics of vulcanized rubber-pico wear, Williams wear and similarly vulcanized rubber. Flexometers (compression type, shear type) and extension fatigue testers are widely used as testers for evaluating the fatigue resistance of the. In each case, in order to measure and evaluate each characteristic with these testers, it is necessary to press an elastic test piece such as vulcanized rubber against a relevant part of the tester main body with a predetermined load. A load applying device for pressing the elastic test piece will be described below with an example of a Lambourn abrasion tester for vulcanized rubber.

First, the specification relating to Japanese Utility Model Laid-Open No. 61-184952 discloses a load applying device shown in FIG. 5 as a diagrammatic side view in which the essential portions are schematically illustrated. In this device, a disc-shaped elastic test piece 2 is moved forward through a slide bearing 32 toward a disc-shaped polishing wheel 1 (only the left half is shown) on the side of the tester main body (not shown) to set a test start position. After the test, the test piece 2 is moved backward from this position to set it as a retracted position (not shown), and an air cylinder 31 for reciprocating the test piece 2 and a pulley 3 for the grinding wheel 1 at the test position.
Weight 33 for applying a predetermined load to the test piece 2 via
Having. The test start position in this type of test apparatus refers to the state immediately before the test piece 2 comes into contact with the grinding wheel 1,
The same applies hereinafter.

The grinding wheel 1 and the test piece 2 are rotationally driven in directions indicated by arrows at mutually different rotational speeds by means not shown. Therefore, when the outer peripheral surface of the rotating test piece 2 comes into contact with the outer peripheral surface of the rotating grinding wheel 1, the speed controllers 35-1 and 35-2 play a role of adjusting the moving speed to prevent the test piece 2 from bouncing. The air cylinder 31 is equipped with. Therefore, the load applying device disclosed in the above specification only achieves the bounce prevention effect at the time of contact,
There is no way to deal with the load fluctuation of the test piece 2 during the test after the contact.

This load fluctuation is caused by the fact that the test piece 2 is an elastic body such as vulcanized rubber, the rotation speeds of the grinding wheel 1 and the test piece 2 are different from each other, and the test piece 2 has a predetermined slip ratio. It is inevitably caused by the fact that the anti-adhesion sand on the surface of the test piece 2 is constantly dropped from the falling sand container 30 between the contact surfaces in the direction of the arrow shown in the figure. Further, the frictional resistance caused by the pulley 34 and the simplified slide bearing 32 is not small, and as a result, the lower limit of the practical load is naturally set, and a so-called dead zone of the load is present.

Next, for the purpose of remedying the above-mentioned disadvantages, a load applying device whose side view is shown in FIG. 6 (Japanese Patent Application No. 6-3
The device described in the document 24541) has become commonly used. This device includes an additional weight 36 for increasing the weight of the load weight 33, a counterbalance weight 36c for the additional weight 36, and an oil damper 37 connected to a lower portion of the additional weight 36. , And the load cell 5 is newly provided.

In the Lambourn abrasion tester, a test piece 2 is rotatably supported by a supporting member 3, the supporting member 3 is attached to one end of a rod 4, and the other end of the rod 4 is supported by a supporting base 38 via a load cell 5. And the weight 3 is fixed to both sides of the support base 38 via pulleys 34 and 34c, respectively.
A plate member 39 that causes the weights 3 and 36 and the weight 36c to act, and that is closer to the other end of the rod 4 and that is orthogonal to the central axis of the rod 4.
The piston rod 31p of the double-acting cylinder 31 is fixed to the plate member 39.

The apparatus shown in FIG. 6 is provided with an additional weight 36 and its counterbalance weight 36c.
A small load can be applied to the test piece 2, the dead zone region load is narrowed, and the mass of the system including the test piece 2 is increased, and the effect of the oil damper 37 is combined. For example, it works so as to absorb the vibration of the polishing piece 1 of the test piece 2. However, even with this device, frictional resistance that cannot be ignored still exists, so the accuracy of the applied load in the low load region is insufficient, and vibrations of the test piece 2 with a wide frequency band must be reliably absorbed over the entire frequency band. I can't.

[0009]

[Problems to be Solved by the Invention]
In the specification relating to Japanese Patent Application No. 6-324541,
A load-bearing device in which the disadvantages of the device shown in FIG.
Is proposed. A side view of this device is shown in FIG. This
The device of the above is the tip of the rod 4 on the side opposite to the connecting side of the carrying member 4.
Connect the end to the piston rod 31p via the load cell 5.
By tying, one double-acting cylinder 31 becomes the test piece 2
Of the grinding wheel 1 to the grinding wheel 1 and the grinding wheel of the test piece 2
It functions both as a load and a load on the unit 1. At this time
The central axis L of the rod 4 is the load cell 5 and the piston lock.
31p coincides with the central axis lines of both, and the extension of the central axis line L
The long line is the axis of rotation X of the grinding wheel 1.₁And the axis of rotation of test piece 2
Heart X _TwoAir cylinder 31 and slide so that
The bearing 32 is attached to the support base 40.

Further, in the chambers on both sides of the piston of the double-acting cylinder 31, individual pressure adjusting devices (speed controllers) 35-1 and 35-2 are provided via conduits 41-1 and 41-2.
The pressurized air that has passed through is supplied under high-precision pressure control.
By setting the pressure difference between both chambers appropriately, the test piece 2
Both the reciprocating movement and the load of a predetermined load on the test piece 2 can be executed.

According to this device, since the pulleys for various weights that cause frictional resistance are not used, the dead zone of the load is further reduced, so that a low load and high precision load can be performed, and the pressurization in the cylinder can be performed. Since air has a damping effect over a wider frequency band than the oil damper 37 described above, the ability of the test piece 2 to absorb bounds and vibrations is further improved.

However, the improved apparatus shown in FIG. 7 differs from the apparatus shown in FIGS. 5 and 6 in which the reciprocating function of the test piece 2 and the load function of a predetermined load are separately shared. Since one double-acting cylinder 31 is responsible for performing the functions of both of them, the load-side chamber volume in the cylinder 31 is set to a predetermined load in order to sufficiently exhibit the dead zone reduction and the effective damping effect. It must be set significantly larger than the required volume.

As a result, it is inevitable that the responsiveness of the test piece 2 to the load fluctuation is lowered and the accuracy of the applied load is naturally limited. In addition to this, the accuracy of controlling the applied load to a predetermined value also depends on the accuracy and stability of the pressure adjusting devices 35-1 and 35-2, and no more can be desired.

Therefore, an object of the present invention is to solve the above-mentioned problems, that is, the dead zone region is restricted to a very low load region outside the practical application, and the load applied to the elastic test piece is unavoidable. It exhibits an excellent responsiveness to load fluctuations that act dynamically, loads a stable and highly accurate load from a practically low load range to a high load range, and can obtain highly accurate test data without variations. Another object of the present invention is to provide a load applying device for a flexible elastic test piece.

[0015]

In order to achieve the above object, the load applying device for an elastic test piece according to the present invention is the device described in the beginning, wherein the load applying means is a separate cylinder device, The load-loading cylinder device is fixed to the double-acting cylinder and the piston rod of the returning cylinder is fixed to the base so that the operating direction and the reciprocating movement direction are parallel to each other. The above-mentioned carrying member is attached to the rod via a load cell.

In carrying out the present invention, preferably, an amplifier for inputting and amplifying a signal from the load cell for converting the load on the test piece into a voltage, and an electric signal from the amplifier for inputting a signal voltage And a preset voltage, and a calculation device that outputs the calculation result as an electric signal, an electric control pressure adjusting device that adjusts the outflow pressure of the inflow pressurized fluid based on the electric signal from the calculation device, A closed conduit for allowing the pressurized fluid that has passed through the device to flow into the load side chamber of the load applying cylinder device.

Further, the load-loading cylinder device is a double-acting cylinder, and is provided with a separate pressure adjusting device for sending a pressurized fluid of a predetermined pressure to a chamber on the load cell side of the cylinder via a closed conduit.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on the embodiments shown in FIGS. FIG. 1 is a side view of a main part of a load applying device for an elastic body test piece in a Lambourn abrasion tester as an example of a dynamic tester, showing a state during a test operation. The elastic body is vulcanized rubber, and a supporting member 3 rotatably supporting the vulcanized rubber test piece 2 is attached to the piston rod 6p of the load-loading cylinder 6 via the rod 4 and the load cell 5. At this time, the axis of the rod 4, the center axis of the load cell 5, and the axis of the piston rod 6p are aligned on one straight line L. The load-loading cylinder 6 may be a single-acting cylinder, and in this case, both the piston type and the plunger type are suitable.

The load-bearing cylinder 6 is fixed to the upper part of the double-acting cylinder 7. The double-acting cylinder 7 is suitable for a single rod cylinder, and its piston rod 7p is attached and fixed to a fixed base 9 extending upward from the base 8. It is important that this fixing is performed under the relationship that the operating direction of the double-acting cylinder 7, that is, the axial center direction of the piston rod 7p and the straight line L are parallel to each other.

While the carrying member 3 is fixed to the support base 10 and the support base 10 is fixed to the pair of slide bearings 11, each slide bearing 11 is slidably engaged with the shaft member 12. Both ends of the shaft member 12 are supported by two support members 13 fixed to the base 8. At this time, it is necessary that the axis of the shaft member 12 and the straight line L maintain a parallel relationship with each other, and that the straight line L passes through the rotation axes X ₁ and X ₂ of the grinding wheel 1 and the test piece 2, respectively. . The shaft member 12 has an axial length that allows the slide bearing 11 to move in the axial direction.

The load applying device having the above-mentioned configuration performs the following operation. First, prior to the test, the test piece 2 is placed on the carrying member 3 at the retracted position of the carrying member 3 (the position closer to the right side of the drawing).
Attach to At this time, a pressurized fluid having a higher pressure than that of the rear (right side of the figure) chamber from one pressure adjusting device (speed controller) 15-1 is provided to the front (left side of the figure) chamber of the double-acting cylinder 7 through the conduit 16-1. For example, pressurized air (hereinafter the same) is introduced. After the mounting of the test piece 2 is completed, the grinding wheel 1 and the test piece 2 are rotationally driven in the directions of arrows in FIG.

Next, the other pressure adjusting device (speed controller) 15-2 is activated to supply the pressurized air controlled to a pressure higher than the pressure of the front chamber (pressure causing a predetermined slow speed) to the conduit 16. -2 to the rear chamber. As a result, according to the sliding guide of the slide bearing 11, the test piece 2 along with the load cell 5 and the load cylinder 6 moves along the straight line L to the polishing start point 1 which is closest to the test start position and then stops. The pressure adjusting device 15-
The pressurized air is supplied to 1, 15-2 through conduits 16-1i, 16-2i extending from a pressurized air source (not shown).

Thereafter, pressurized air having a predetermined pressure suitable for producing a desired load is supplied to the rear chamber of the load cylinder 6 to project the piston rod 6p, and the vulcanized rubber test piece 2 is polished. Press on wheel 1. At this time, the load on the test piece 2 is detected by the load cell 5, and the detected value is fed back to the electric control pressure adjusting device 14 to supply pressurized air having a pressure corresponding to an appropriate load to the cylinder 6 via the conduit 17. Guide to rear chamber and hold proper load during test. Pressurized air is supplied to the electrically controlled pressure regulator 14 through a conduit 17i extending from a pressurized air source (not shown). After the test is completed, the above operation process may be reversed.

The load applying apparatus described above is exclusively used for the test piece 2.
The double-acting cylinder 7 that plays the role of the reciprocating movement function of the test piece 2 and the load-loading cylinder device 6 that plays the role of the load-loading function of the test piece 2 are separately provided. The chambers 6 and 7 do not require such a large volume, and therefore the load speed as well as the moving speed of the test piece 2 can be controlled easily, and as a result, the load accuracy over a wide range from low load to high load can be improved. .

Also, since the double-acting cylinder 7 for reciprocating movement serves as a damper that responds quickly to load variations, the dead zone of the applied load can be shifted to the lower side of the used load area. This greatly contributes to the improvement of the accuracy of low load application. Furthermore, the fact that the mass against the load fluctuation is large also contributes to the improvement of the accuracy of the low load.

An example of development of the above-described embodiment will be described below with reference to FIG. 2 which is a block diagram showing a simplified diagram of a main part of the apparatus shown in FIG. An amplifier 18 for amplifying an input signal from the load cell 5 for converting the load of the test piece 2 pressed against the grinding wheel 1 into a voltage, and an electric signal from the amplifier 18 are input, and the input signal voltage and a preset voltage And a calculation device 19 for calculating a difference between the calculation result and the calculation result as an electric signal to the electric control pressure adjusting device 14.

A reference voltage corresponding to the set load for the test piece 2 is input and stored in advance in the arithmetic unit 18, and the arithmetic unit 18 compares the reference voltage with the amplified voltage of the output voltage detected by the load cell. If there is a difference between the two voltages, the voltage obtained by adjusting the voltage difference to the reference voltage is output to the pressure adjusting device 14 as an electric signal. In response to this output signal, the electric control pressure adjusting device 14 quickly adjusts the pressure in the chamber 6c of the cylinder 6 according to the voltage difference from the reference voltage. That is, if the voltage difference is a positive voltage, the pressure of the pressurized air is reduced by a corresponding amount, and if the voltage difference is a negative voltage, the pressure of the pressurized air is increased by a corresponding amount.

By applying the above feedback system, the output air pressure can be controlled with extremely high sensitivity and accuracy over the entire range from the low load range to the high load range by the electric control pressure adjusting device 14, and as a result, It contributes to loading the test piece 2 with stable and highly accurate load from low load to high load. Also, when a disturbance force such as a bounce or vibration is applied to the test piece 2, it responds promptly in the same manner as described above, and contributes to the prevention of the adverse influence of the disturbance on the test.

Still another embodiment is shown in FIGS. FIG.
The main difference between the load-applying device shown in FIG. 1 and the device of FIG. 1 is that the load-loading cylinder 6A is a double-acting cylinder, and the opposite side of the load-loading pressure chamber 6Ac.
That is, the chamber 6Ad (see FIG. 4) on the load cell 5 side (piston rod 6Ap side) is provided with a separate pressure adjusting device 20 and a relief valve 21 for supplying pressurized air of a predetermined pressure P ₀ via a conduit 22.

Electrically controlled pressure regulator 14 to chamber 6
Test piece 2 when the pressurized air pressure P supplied to Ac is P≈P ₀
Electric control pressure adjustment device 1 so that the applied load is zero
4 and the operating point of the arithmetic unit 19 are shifted by the pressure P, and otherwise the process as described above is followed. Pressurized air is supplied from the same source of pressurized air as the electrically controlled pressure regulator 14 to the pressure regulator 20 via conduit 22i. The relief valve 21
Performs an accurate control of the air pressure P ₀ and an operation for increasing the response speed during pressurization.

The chamber 6 is controlled by a separate pressure adjusting device 20.
By applying the preload P ₀ in the chamber 6Ad as a counter pressure of Ac, there is a slight dead zone near the pressure 0 (zero), and therefore, there is a disadvantage in accuracy and stability for a minute load load. This disadvantage of the electrically controlled pressure adjusting device 14 can be wiped off, and even an extremely small load can be stably loaded with sufficient accuracy.

Although the elastic vulcanized rubber test piece has been described above, this device can be applied to other elastic material test pieces such as thermoplastic materials, and further, as a dynamic tester. Although the Lambourn abrasion tester is taken as an example, other than that, it can be applied to a tester such as a flexometer that performs a dynamic test in a state in which a constant load is applied to a test piece in advance.

[0033]

According to the present invention, with respect to the load applied to the dynamic tester by the elastic body test piece, the dead zone region is suppressed to a very low load region which is not practically applicable, and the test piece is inevitably generated. It is possible to exert a remarkably excellent responsiveness to load fluctuations, and as a result, it is possible to apply a sufficiently stable and highly accurate load to a test piece from a practically low load area to a high load area. As a result, it is possible to provide a load applying device for an elastic body test piece capable of obtaining highly accurate test data without variations.

[Brief description of the drawings]

FIG. 1 is a side view of a main portion of a load applying device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a part of the apparatus shown in FIG. 1 and a block diagram together.

FIG. 3 is a side view of a main part of a load applying device according to another embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a part of the apparatus shown in FIG. 3 and a block diagram together.

FIG. 5 is a schematic side view of a conventional load applying device.

FIG. 6 is a side view of a main part of another conventional load applying device.

FIG. 7 is a side view of the main parts of a load applying device as an example in which the device shown in FIG. 6 is improved.

[Explanation of symbols]

 1 Grinding wheel 2 Test piece 3 Supporting member 4 Rod 5 Load cell 6, 6A Load cylinder 7 Reciprocating double-acting cylinder 8 Base 9 Fixing stand 10 Supporting stand 11 Slide bearing 12 Shaft member 13 Supporting member 14 Electrically controlled pressure Regulator 15-1, 15-2 Pressure regulator 16-1, 16-2, 17, 22 Conduit 18 Amplifier 19 Arithmetic device 20 Pressure regulator 21 Relief valve

Claims (3)

[Claims] 1. A test piece is reciprocated between a carrying member carrying an elastic test piece and a test starting position of the test piece with respect to the main body of the dynamic tester and a retracted position separated from the carrying member via the carrying member. In a load applying device for an elastic body test piece having a double-acting cylinder and means for applying a load to the test piece with respect to the main body of the dynamic testing machine, the load applying means is a separate cylinder device, and the operating direction of the cylinder device And the reciprocating direction are parallel to each other, the load-loading cylinder device is fixed to the double-acting cylinder, and the piston rod of the returning cylinder is fixed to the base, and the piston rod of the load-loading cylinder device is fixed. A load applying device for an elastic body test piece, characterized in that the above-mentioned carrying member is attached via a load cell. 2. An amplifier for inputting and amplifying a signal from the load cell for converting the load of the test piece into a voltage, and a difference between the input signal voltage and a preset voltage by inputting an electric signal from the amplifier. Is calculated and the calculation result is output as an electric signal, an electric control pressure adjusting device that adjusts the outflow pressure of the inflow pressurized fluid based on the electric signal from the arithmetic device, and the pressurized fluid that has passed through the device is loaded. The load-carrying device according to claim 1, further comprising a closed conduit for flowing into a load-side chamber of the load cylinder device. 3. The load-applying cylinder device is a double-acting cylinder, and is provided with a separate pressure adjusting device for sending a pressurized fluid of a predetermined pressure to a chamber on the load cell side of the cylinder via a closed conduit. Load device.