JP4194726B2 - Friction and wear testing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a friction and wear tester for evaluating the frictional force and the amount of wear on the surface of metal or ceramic.
[0002]
[Prior art]
The flat member is slid in the state where the same member or the other member (second sample) is in pressure contact with the flat member (first sample), and the friction force and wear amount between these members are changed. Various friction and wear testing machines to be evaluated are known.
[0003]
For example, as shown in FIG. 5A, the flat plate member 11 is rotated from the upper side of the flat plate member 11 while the chip member 12 is in pressure contact with the flat plate member 11, and is generated on the rotation axis of the flat plate member. A friction tester that detects the friction force by detecting torque, or the plate-like member 11 in a state in which the tip-like member 12 is pressed from above the plate-like member 11 as shown in FIG. A friction test for detecting a frictional force by detecting a lateral force acting on the chip-like member 12 by a tension / compression type sensor (not shown) brought into contact with the chip-like member 12 by reciprocating horizontally. There are machines.
[0004]
[Problems to be solved by the invention]
In such a conventional friction tester, the chip-like member 12 is pressed from one side (the upper side in the figure) of the flat plate-like member 11, so that in the case shown in FIG. If a torque cross occurs due to pressing on a certain rotating shaft, or if the direction of the pressing force deviates from the center of the rotating shaft, stable rotation of the plate-like member 11 cannot be ensured, resulting in stable frictional force. There was a problem that measurement was not possible. Further, in the case shown in FIG. 5B, when the flat member 11 is worn or distorted by the pressing force, there is a problem that an uneven load is applied to the member 11 and a torcross is generated, so that accurate measurement cannot be performed.
[0005]
Therefore, an object of the present invention is to provide a friction and wear tester that does not have a torque cross and can perform stable measurement. Another object of the present invention is to provide a friction and wear tester that can cope with a change in the contact position due to a load or wear and can perform accurate measurement.
[0006]
[Means for Solving the Problems]
According to the present invention, a stable and accurate measurement can be performed by conducting a friction test on a flat plate member with an equal load applied from both sides thereof. That is, the friction and wear tester of the present invention includes a driving unit that applies a predetermined motion to the first sample, and a pressing unit that presses the second sample against the first sample with a predetermined pressing force. The first sample is moved while the second sample is in pressure contact with the first sample, and the frictional force between the first sample and the second sample or the wear amount of the first or second sample In the friction and wear tester for measuring the pressure, a pressing means for applying the same pressing force as the pressing force of the second sample from the side of the first sample opposite to the side on which the second sample is pressed is provided. And
[0007]
The friction and wear tester of the present invention preferably includes means for measuring the frictional force between the first sample and the second sample in the second sample. Thereby, the influence by the frictional force which arises between a 1st sample and a press means can be excluded.
[0008]
The friction and wear tester of the present invention preferably includes a friction reducing means for minimizing the friction between the second sample and the pressing means between the second sample and the pressing means.
[0009]
As one aspect of the friction and wear tester of the present invention, the driving means drives the first sample to reciprocate between the second sample and the pressing means.
[0010]
As another aspect of the friction and wear tester of the present invention, the driving means drives the first sample to rotate between the second sample and the pressing means. In this case, even if the rotation of the first sample is a rotation about an axis parallel to the direction of the pressing force of the second sample, an axis perpendicular to the direction of the pressing force of the second sample is used as the rotation axis. Rotation is also possible.
[0011]
According to such a friction and wear tester of the present invention, an equal pressing force is exerted on the first sample from the top and bottom or from the left and right, so that even if the first sample is distorted or worn, an uneven load is not applied. The torcross resulting from the uneven load can be eliminated. In addition, when the first sample is rotated, stable measurement can be performed without causing the rotation to become unstable.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
FIG. 1 is a view showing an embodiment of a friction and wear tester according to the present invention. This friction and wear tester mainly includes a mechanism for driving a sample disk 11 which is a first sample, and a mechanism for driving a sample disk 11. 2, a mechanism for pressing the sample chip 12 from above, a mechanism for pressing the sample disk 11 from below the sample disk 11, and a friction between the sample disk 11 and the sample chip 12 attached to the sample chip 12. The sample disk 11 and the sample chip 12 are housed in the housing 10. The sample disk 11 and the sample chip 12 include a mechanism for detecting force and a control / measurement unit for calculating frictional force and wear amount. The casing 10 is filled with oil, gas, or the like as necessary. The housing 10 can be measured not only at room temperature but also at a high temperature by heating means (not shown) or by controlling the temperature of supplied oil or gas.
[0014]
The mechanism for driving the sample disk 11 includes a cam mechanism (not shown) that changes the rotation of the motor into a horizontal reciprocating motion, a connecting shaft 21 connected to the cam mechanism, and a disk holder 22. Is slidably supported on the side wall of the housing 10. The sample disk 11 is fixed to the disk holder 22 with screws or the like and reciprocates in the direction of arrow A integrally with the connecting shaft 21.
[0015]
The mechanism for pressing the sample chip 12 includes a chip holder 31 to which the sample chip 12 is fixed, a holder 33 connected to the chip holder 31 by a cross roller 32, and a first pressing force that applies a vertical pressing force to the holder 33. And a lifting guide 35 that is interposed between the holder 33 and the first cylinder 34 and guides the lifting and lowering of the holder 33.
[0016]
The cross roller 32 is a combination of a cage in which precision rollers are alternately orthogonally assembled and a rail provided with a V-groove so that the roller and the V-groove face each other. Allows frictional motion. Here, by connecting the chip holder 31 and the holder 33 with the cross roller 33, the frictional force acting between the holder 33 and the chip holder 31 when the sample chip is pressed is minimized, and the chip holder 31 and the sample chip fixed to the chip holder 31 are fixed. 12 can move freely in the horizontal direction.
[0017]
The elevating guide 35 receives the pressing force of the first cylinder 34 at the upper end while the holding tool 33 is fixed to the lower end. The guide portion 35a of the elevating guide 35 is slidably supported by a fixing member 36 fixed to the upper portion of the housing 10, and can move only in the vertical direction. This ensures that a vertical pressing force is applied to the holder 33 fixed to the lower end.
[0018]
The first cylinder 34 is fixed to the upper door 10a that can be opened and closed with respect to the housing 10 as shown in FIG. Although it is at a position above the guide 35, it can be retracted to an unobstructed position by opening the upper door 10a during sample setting or maintenance.
[0019]
The mechanism for pressing the sample disk 11 from below is fixed to the second cylinder 41 installed at the bottom of the housing 10, the lifting guide 42 receiving the pressing force of the second cylinder 41, and the upper end of the lifting guide 42. A pressure sensor for measuring a pressing force, for example, a load cell 44 is installed between the second cylinder 41 and the lifting guide 42.
[0020]
In order to minimize the load applied to the mechanism that drives the sample disk 11, the pressing member 43 is made of a material that has a small frictional resistance and is less likely to wear. For example, a bearing alloy (oilless metal) can be used as such a material. A bearing may be provided on the contact surface.
[0021]
Similarly to the upper lifting guide 35, the lifting guide 42 is slidably supported by a fixing member 45 fixed to the bottom of the housing 10, and can move only in the vertical direction. This ensures that a vertical pressing force is applied to the pressing member 43 fixed to the upper end.
[0022]
The first cylinder 34 and the second cylinder 41 are connected to the same drive source (not shown) so that the same pressing force can be generated. As the drive source, known ones such as a hydraulic cylinder and an air cylinder can be used. The load applied from above and below the sample disk 11 via the first cylinder 34 and the second cylinder 41 is detected by the pressure sensor 44 and sent to a control unit (not shown), where it is used for calculating the frictional force.
[0023]
As shown in FIG. 2A, a torque detection load cell 52 is connected to the chip holder 31 via a torque transmission lever 51 as a mechanism for detecting the frictional force between the sample disk 11 and the sample chip 12. ing. The torque detection load cell 52 is fixed to the outside of the side wall of the housing 10 and detects compression and tension (torque) acting on the chip holder 31. The torque detected by the load cell 52 is sent to the control unit and used for calculating the frictional force.
[0024]
As described above, the tip holder 31 and the holder 33 are connected by the cross roller 32, and the tip holder 31 is free to move in the horizontal direction. Therefore, the sample disc 11 and the sample disc 11 are moved in the horizontal direction. The frictional force generated between the sample chips 12 can be transmitted from the chip holder 31 to the load cell 52 and detected.
[0025]
Next, the operation of the friction and wear tester having the above configuration will be described.
[0026]
First, with the upper door 10a opened, the sample disk 11 and the sample chip 12 are set in the disk holder 22 and the chip holder 31, respectively, and the upper door 10a is fixed to the housing 10. Next, the first and second cylinders 34 and 41 are driven to press the sample chip 12 against the upper surface of the sample disk 11 and the pressing member 43 against the lower surface. Thereby, the sample disk 11 receives equal pressing force from both sides. This pressing force is detected by the load cell 44, and the load cell 44 sends a signal corresponding to the pressing force to the control unit.
[0027]
In this state, the cam mechanism is driven, and the disk holder 22 and the sample disk 11 are horizontally reciprocated by the connecting shaft 21. Here, since the sample chip 12 is only subjected to a pressing force from above by the holder 33 and can move freely with respect to the holder 33, the sample disk 11 and the sample are moved by the movement of the sample disk 11. The frictional force generated between the tip 12 and the tip 12 can be transmitted to the load cell 52 connected to the sample tip 12. The load cell 52 sends a signal corresponding to the detected compression and tensile force to the control unit.
[0028]
The control unit calculates the friction coefficient μ by the following equation using signals (pressing force W, friction F) from the two load cells.
[0029]
μ = F / W (1)
[0030]
As described above, this friction and wear tester measures the frictional force between the sample disk 11 and the sample chip 12 with the same load applied from both sides of the sample disk 11, so that the sample disk 11 is distorted or unevenly loaded. Accurate measurement is possible without any torque cross.
[0031]
In the above embodiment, the case where the sample disk 11 is reciprocated has been described. However, the frictional wear tester of the present invention may rotate the sample disk 11 as shown in FIG. In this case, the mechanism for rotating the sample disk 11 can be configured by fixing the disk holder to a rotating shaft that is rotated by a motor (not shown).
[0032]
In the above description, a case where a flat disk is used as the first sample and a chip is used as the second sample has been described. However, the shape of the sample is not limited to these combinations and can be various shapes. . For example, the friction and wear tester of the present invention can also be applied to a friction and wear tester that is a combination of a pin and a V-shaped member known as a so-called pin / V block type tester.
[0033]
FIG. 4 shows an embodiment of a pin / V block type friction and wear tester according to the present invention. This friction and wear tester includes a cylindrical pin 61 as a first sample and a pin 61 from both sides. This is a testing machine for measuring the frictional force and wear with the test pieces 62 and 62 ′, which are the second samples having the V-shaped groove to be pressed.
[0034]
The pin 61 is fixed to a rotating shaft 63 that is rotated by a motor (not shown), and a sensor, for example, a torque meter 64 for measuring a frictional force is attached between the rotating shaft 63 and the motor.
[0035]
On the other hand, the test pieces 62 and 62 ′ are fixed to the pressing shafts 66 and 66 ′ via the universal joints 65 and 65 ′, respectively. The pressing shafts 66 and 66 ′ are slidably supported by guides 67 and 67 ′ fixed to the side wall of the casing 60, and a cylinder 68 for driving the pressing shafts 66 and 66 ′ horizontally at the rear end thereof. 68 'is connected. These cylinders 68 and 68 'are connected to the same drive source so that the same pressing force can be generated. Also in this case, a known source such as a hydraulic cylinder or an air cylinder can be used as the drive source. A pressure sensor, for example, a load cell 69 for detecting a load applied to the test piece 62 by the cylinder is attached between one pressing shaft 66 and the cylinder 68.
[0036]
Further, the casing 60 can be filled with oil, gas, or the like as in the embodiment of FIG. 1, so that measurement in the presence of oil or gas or measurement at a desired temperature can be performed. It has become.
[0037]
In such a configuration, the pin 61 and the test pieces 62 and 62 ′ are set in oil, the test pieces 62 and 62 ′ are arranged on both sides of the pin 61, and the cylinders 68 and 68 ′ are driven to test pieces 62, 62 ′ is pressed with the same pressing force as the pin 61. At this time, since the test pieces 62 and 62 ′ are fixed to the pressing shafts 66 and 66 ′ via the universal joints 65 and 65 ′, the V-shaped groove is surely provided along the outer peripheral surface of the cylindrical pin 61. Can contact. In this state, the motor connected to the rotating shaft 63 is driven to rotate the pin 61. The frictional force generated between the pin 61 and the test pieces 62 and 62 ′ by the rotation of the pin 61 is detected by a torque meter 64 provided on the rotating shaft 63.
[0038]
The control / measurement unit calculates the friction force F and the friction coefficient μ based on the following equations from the torque TQ detected by the torque meter 64 and the pressing force Wg to the pin detected by the load cell 69.
[0039]
F = TQ / r (2)
μ = F / 4W (3)
W = Wg / cos (90-θ / 2) (4)
[0040]
In equations (2) to (4), r represents the radius of the pin, W represents the pressing force in the radial direction (perpendicular to the surface) applied from one test piece to the pin, and the angle formed by the V groove of the test piece. .
[0041]
In this embodiment, an equal pressing force can be applied from both sides of the pin 61. Therefore, even when the rotating shaft 63 is slightly shifted to one of the two test pieces, the balance between the left and right loads is not lost. Reliable measurement can be performed.
[0042]
Also, unlike the conventional friction and wear tester in which a pair of V blocks are rotated and brought into contact with the pins, horizontal pressing force is applied from both sides, so even if the pressing force is large, the cylinder The test piece can be moved in the left-right direction only with a force (sufficiently smaller than the pressing force) that resists the O-ring resistance.
[0043]
As mentioned above, although this invention was demonstrated based on the Example shown on drawing, this invention is not limited to these Examples, A various change is possible. For example, the mechanisms and sensors employed in the respective parts of the above embodiments can be replaced with various known mechanisms and sensors.
[0044]
【The invention's effect】
The friction and wear tester and method according to the present invention measure the friction force and wear generated between two samples by pressing them while measuring them while applying equal pressing force from both sides to one sample. Accurate and stable measurement can be performed by eliminating torcross due to sample distortion and uneven load.
[Brief description of the drawings]
1A and 1B are diagrams showing an embodiment of a friction and wear tester according to the present invention, in which FIG. 1A is a front view, and FIG. 1B is a side view; FIG. 3 is a schematic view showing another embodiment of the friction and wear tester of the present invention. FIG. 4 is an overall configuration diagram showing another embodiment of the friction and wear tester of the present invention. Diagram showing machine [Explanation of symbols]
11. Sample disk (first sample)
12. Sample tip (second sample)
21 ・ ・ ・ ・ ・ ・ Connection shaft (drive means)
34 ······ First cylinder (pressure contact means)
41... Second cylinder (pressing means)
43 ··· Pressing member (pressing means)
52 .... Load cell (measuring means)

Claims (2)

Driving means for applying a predetermined rotational motion to the first sample, and pressure contacting means for pressing the second sample against the first sample with a predetermined pressing force from a direction perpendicular to the rotational axis of the rotational motion; The first sample is rotated while the second sample is in pressure contact with the first sample, and the frictional force between the first sample and the second sample or the first or second sample is rotated . Measuring means for measuring the amount of friction, wherein the pressure contact means is disposed on both sides of the first sample in a direction perpendicular to the rotation axis, and each has pressing means, and the pressing means on both sides are the same drive A friction and wear tester connected to a power source and applying the same pressure. 2. The friction wear tester according to claim 1, wherein the measurement unit includes a torque measurement unit provided in the drive unit and a pressure detection unit provided in the press contact unit, and the torque measured by the torque measurement unit. And a frictional wear tester that calculates a frictional force and a friction coefficient from the pressing force detected by the pressure detecting means.

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