SI21579A - Preparation for levelling a clamping assembly of devices for determining resistivity against wear due to sliding friction - Google Patents

Abstract

The aim of the invention is to provide the possibility of controlling the process of panel (2) levelling with a clamping assembly for determining resistivity against wear due to sliding friction. The panel holds the test piece (3) by which it would be possible to ensure the perpendicularity of the measured surface (31) of the test piece regarding the rotating axis (110) of the clamping assembly. The preparation includes at least one levelling indication tool (5, 5', 5'', 5''') which is attached to the levelling panel (2) and along with it as well as any current rotating test piece around the specified rotating axis (119). For this the specified tool (5, 5', 5'', 5''') consists of at least one enclosure (51) which provides the adequate quantity of liquid (52) along with the corresponding gas container (53).

Description

UNIVERSITY OF LJUBLJANA Faculty of Mechanical Engineering

MPK: GOI N 03/56 GOI B 05/24

Preparation for leveling the clamping assembly of a device for determining wear resistance due to sliding friction

The invention can be classified, on the one hand, in the field of physical testing and measurement and ascertainment of the properties of materials, namely, the determination of wear resistance due to sliding friction, and, on the other, the devices for measuring angles and determining (co) axes.

The invention is based on the problem of how, in the clamping assembly of a device for determining wear resistance due to sliding friction, to provide the possibility of visual control of the leveling of the plate on which the test piece is mounted, in order to quickly and easily ensure the rectangularity of the measuring surface of the test specimen relative to the rotational the axis of the clamping assembly.

A well-established and recognized method of measuring the resistance to wear due to sliding friction dictates that the wear resulting from sliding friction be measured on one of the surfaces of a flat rotary test piece rotating about an axis perpendicular to said measuring plane, at the same time however, a stationary tester is pressed against said measuring surface with a certain force, whose direction and strength are predetermined.

Measurements can be made on a device, such as e.g. known as PIN-DISC. Such a device comprises a frame in which, by means of a vertical mandrel, a holder is formed, which is designed as a hollow cylinder or. like a kind of cylindrical, flat-bottomed cup. A support plate can be attached to this holder in the area of its bottom, eg. glued rotary test piece. With the aid of said mandrel, which is connected to a suitable propulsion means by suitable transmission means, the holder is rotatable about a horizontal axis, the test plane being horizontal. The test subject is usually designed as a disc. On the other hand, there is provided in the frame of the device in question a bed in which a stationary tester is engaged, the device allowing this stationary tester to exert a predetermined force against the measuring surface of the rotating tester with a predetermined force on a given radius relative to the axis rotation of the rotating test piece.

Basically, these features of the said device are also covered by US 6,418,776 BI, which in addition describes a number of other details concerning a completely different problem from that of the present invention. Namely, the solution of US 6,418,776 BI is based on the criticism of a previously known device according to US 5,795,990, in which both subjects are rotatable, creating an orbital, planetary motion between them, whose effects are difficult to measure and therefore the results are often unclear or unclear. inaccurate. Due to the presence of two actuators, it would also result in considerable deformation in the device itself, which again leads to a less accurate measurement. Therefore, the purpose of US 6,418,776 BI is to remedy the aforementioned deficiencies and, in addition, to expand the measurement capabilities in other ways. For the purposes of evaluating the present invention, it is sufficient to conclude that US 6,418,776 BI is leveled by lowering or lowering. the stationary subject is not even queried. The tester is simply screwed to the bottom of the holder, and with a cane, is held in place by the device. However, it should be appreciated by the skilled person that in this way satisfactory measurement results can only be expected if the measuring surface is indeed flat and its perpendicularity to the axis of rotation is at the same time ensured. Just by screwing the test piece into the bottom of the holder, this simply cannot be achieved. However, it is possible to achieve this, for example. in this way, to remove the retainer, a test piece with a precisely machined flat measuring surface is placed therein, and then, together with the retainer, the holder is clamped to another leveling device. When, with proper leveling and checking of deviations e.g. by means of a measuring clock, they reach the perpendicularity of the measuring surface with respect to the axis of the thorn, they can clamp the thorn together with the holder and the test piece placed in the holder back into the measuring device. In this case, a sufficient number of holders should be available to ensure adequate measurement concentration and utilization of the measuring device, since only one can be attached to the device during the measurement of wear resistance, while the remaining test pieces can be leveled by the remaining holders. Another way of ensuring the perpendicularity between the measuring plane of the rotating specimen and the axis of rotation can be ensured by the extremely precise machining of the two parallel surfaces of the rotating specimen as well as the extremely carefully designed holder, with extreme care during mounting of the specimen in the holder. Given the costs involved, such an approach seems particularly dubious.

The yet unpublished Slovenian patent application (No. P-20030120) also describes a new and improved solution of a clamping assembly for wear resistance due to sliding friction consisting of at least a holder and a rotating test piece. Said bracket comprises a mandrel by which it can be clamped into the device to provide positioning and rotation of the bracket about its axis. The rotary test piece is attached to said holder in such a way that its measuring surface runs perpendicular to said axis of the holder. For this purpose, the holder comprises at least substantially a flat support surface, in particular the bottom of the recess, which extends at least substantially orthogonal to the rotary axis and in which a spring-supported ball is mounted in the central region coinciding with said axis. On said ball there is a leveling plate with a test piece attached to it, the measuring surface of which is facing away from said leveling plate. In this case, the leveling plate and the holder are equipped and interconnected by at least three connecting means, each of which optionally allows locally moving the leveling plate in the direction towards the supporting surface of the holder and against the force of the spring-supported spheres or. moving this leveling plate away from the support surface of the holder. The aforementioned connecting means between the retainer and the leveling plate with a self-attached test piece are preferably formed with respect to the rotary axis of the symmetrically arranged threaded holes available in the bottom of the holder and the screws inserted through the corresponding holes in the leveling plate with a suitable looseness. Such a leveling plate, supported on a spring-supported ball, is possible by screwing or. tilt the selected screw in the desired direction. In this way, it is theoretically possible to ensure the perpendicularity of the test surface of the test specimen with respect to the rotary axis, but in practice the leveling is relatively slow. Namely, after placing the plate in the holder, it is not possible to determine its tilt precisely enough, so it is necessary to place it above the plate, for example. and gradually rotate the panel to determine the maximum location by measuring. This is followed by tightening or loosening the appropriate screw, but again it is impossible to know in advance whether or not this screw will be sufficient to level the board. In most cases, it is highly probable that the screw rotation is either insufficient to ensure the orthogonal measurement of the test surface relative to the rotary axis, or even too large, which also means that the perpendicularity is not reached. This is followed by re-rotating the leveling clamp assembly and controlling the position of the leveling plate with a timer and tightening or loosening the one or any of the remaining screws. It will be understood by one of skill in the art that such leveling is an extremely time-consuming and tedious approach to the end goal in steps whose number and duration cannot be predicted in advance. Therefore, there is no doubt that the position of the panel can be as accurately ascertained visually and based on these findings the process of leveling can be brought to at least the final phase of the finest leveling, in order to quickly and easily at least approximate the desired perpendicularity of the measuring surface of the subject with respect to the rotary axis. thus significantly shortening the leveling time.

The device according to the invention is intended for leveling the clamping assembly of a device for determining wear resistance due to sliding friction. The clamping assembly then consists of at least a holder and a rotating test piece with a measuring surface. The holder comprises a mandrel by which it can be clamped into the device to provide positioning and rotation of the holder about its axis or. rotary axes. The rotary test piece is fixed to said holder in such a way that its measuring surface runs perpendicular to said rotary axis. The device according to the invention comprises at least one leveling indication device, which is mounted on the leveling plate and rotatable about the rotary axis together with it as well as with the respective rotary test piece. The said device consists of at least one housing in which an adequate amount of liquid is available together with a suitable gas bladder. Optionally, therefore, a level indication device is mounted on the same surface of the leveling plate as a rotary test piece with a measuring surface designed either as a circular level or as a spherical level. In a further embodiment of the invention, on the same surface of the leveling plate, at least two leveling devices designed for leveling indication devices are provided as rotating test pieces with a measuring surface, extending radially in each direction along said surface of the leveling plate. In particular, it is advantageous if at least three linear-level leveling means are provided on the same surface of the leveling plate as a rotating test piece with a measuring surface, extending in radial direction to each other along said surface of the leveling plate, e.g.

each of the leveling indications may be located in a groove available on the leveling plate in the area of its upper surface on which the test piece is located, comprising the measuring surface. Further, each leveling indicating device is either individually or indivisibly connected to the leveling plate. In a particular embodiment of the invention, the leveling indicating device is mounted on a support extending radially in the leveling plate and connected to the latter with the latter, in particular by means of a pin. In the latter embodiment, it is particularly advantageous if the leveling indicating device is mounted on a support that is detachably connected to the latter in the region of the cutout of the leveling plate. This means that the leveling indication device is mounted on a beam extending in the radial direction of the leveling plate, designed with a cutout as well as a radial hole available in the region of said cutout, wherein said support is inserted into said hole and thereafter selection by means of a pin secured against pull.

The invention will now be explained on the basis of the embodiments shown in the accompanying drawing, which show FIG. 1 shows a clamping assembly of a device for determining the wear resistance due to sliding friction, together with a rotary test piece and the first embodiment of a leveling indication device, in the plan of FIG. 2 is a cross-sectional view of the horizontal plane II - II of FIG. 1, FIG. Fig. 3 is a clamping assembly with a further embodiment of the leveling indication of the device, again in the plan, FIG. Fig. 4 shows a clamping assembly with a further embodiment of a leveling indicating device, again in the plan; 5 also shows in the plan a clamping assembly with a further embodiment of a leveling indicating device, and FIG. 6 is a cross-sectional view in the plane VI - VI of FIG. 5.

The clamping assembly consists of a holder 1 in which the leveling plate 2 is mounted with a rotating test piece 3. The axisymmetrically designed holder 1 consists of a mandrel 11 and a cylindrical recess 12 with a straight and with respect to the longitudinal axis 110 of the holder 1 with a rectangular bottom 120. The mandrel 11 is constructed in such a way that it can be clamped into the corresponding (not shown) socket of each measuring device, thus providing positioning of the holder 1 on the one hand, and on the other, providing a drive allowing rotation of the holder 1 and thus the rotation of the subject 3.

In the bottom 120 of the holder 1 there are three threaded holes 13 ', 13, 13' symmetrically arranged in the axis 110. In the central region 121 of the bottom 120 of the holder 1, a further recess 122 is provided in which a ball 125 is supported by a spring 123.

Test subject 3 as such is machined to a certain extent such that at least its measuring surface 31 is flat, which means that at least the flatness of said surface 31 is achieved within the frame for the purpose of carrying out measurements of tolerances.

Said test subject 3 is attached to the leveling plate 2 in the most expedient manner by gluing it to the available surface 21 of the leveling plate 2 so that its measuring surface 31 is turned away from the plate 2.

The leveling plate 2 (FIGS. 1 and 2) is provided with three through holes 22 ', 22, 22', the arrangement of which is aligned with the arrangement of the previously mentioned threaded holes 13 ', 13, 13' in the bottom 120 of the holder 1. Through said holes 22 ', 22, 22' are insertable screws 23 ', 23, 23' which pass through the leveling plate 2 with adequate looseness and can be screwed into the holes 13 ', 13, 13' in the bottom 120 of the holder 1.

When the test piece 3 is mounted on the corresponding surface 21 of the leveling plate 2 and when the spring-supported ball 125 is positioned in the recess 122 so that it protrudes partly from the area of said recess 122 above the plane of the bottom 120 of the holder 1, the holder 1 installs the leveling plate 2 so that test subject 3 with its measuring surface 32 turned away from the mandrel 11, preferably upwards. The leveling plate 2 rests on the ball 125, so that due to the projection of the ball 125 from said recess 122 on the surface of the bottom 120 of the holder 1 it rests at a single point, while the rest of the plate 2 is kept at a distance from the bottom 120 of the holder 1.

Thereafter, screws 23 ', 23, 23' are inserted through holes 22 ', 22, 22' in panel 2 and screwed in to holes 13 ', 13, 13' in the bottom 120 of the holder 1. To this extent, plate 2 is leveled. supported exclusively by ball 125, which is supported by a spring 123, thereby pushing the plate 2 away from the bottom 120 of the recess 12 of the holder 1. In these conditions, the leveling plate 2 can be brought closer to the bottom 120 or removed from the bottom 120 by tightening or loosening the screws 23 ', 23, 23'. In this way, it is possible to achieve the leveling of the plate 2 and thus the measuring surfaces 31 of the test specimen 3 with respect to the plane of the bottom 120 or. with respect to the longitudinal axis 110 of the holder or. tma 11. If e.g. to the position as in FIG. 2, a purely schematically illustrated stationary test piece 4, instead of clamping an unspecified measuring clock, the latter is located on the measuring surface 31 of test specimen 3. By slowly rotating the holder 1 and successively tightening or. by loosening the three spaced screws 23 ', 23, 23' due to the support of the plate 2 with the ball 125, the perpendicularity of the measuring surface 31 of the test piece 3 can be achieved practically independently of the geometry of the bottom 120 of the holder or the contact surface 32 of the test piece and without any clearance.

The leveling of panel 2 can be significantly accelerated in such a way that at least one level indication device 5 is provided in panel 2. This device 5 can basically be designed as a level, e.g. either as a circular or spherical level or as a line level or otherwise, comprising at least a housing 51 in which fluid 52 is closed together with the bladder 53 of the gaseous substance (Fig. 1). In the example shown in FIG. 1, the accessory 5 is mounted on the upper surface 21 of the leveling plate 2, that is, on the same surface 21, on which is also mounted a rotary test piece 3, on which the measuring surface 31 is located.

Even more precise leveling can be achieved e.g. by means of a leveling indicating device 5, consisting of three radially extending linear vials 5 ', 5, 5', which are optionally mounted in radial grooves 50 ', 50', 50 'on the same surface 21 of the leveling plate 2 .

On the other hand, greater reliability in determining the respective inclination of the leveling plate 2 is possible than in the case of FIG. 1 to provide by installing more, e.g. at least two or three accessories 5 to the leveling plate 2, more specifically to its surface 11 from the side 11, facing the surface 21. An example is shown in FIG. 4.

When said leveling of the test piece 3 is completed and therefore the measuring surface 31 of the rotating test piece 3 is perpendicular to the axis of rotation 110, it is possible to establish the rotation of the test piece 3 at an appropriate speed, and then against the measuring surface with the required force, e.g. 100 N, press stationary test piece 4, which in FIG. 2, as already mentioned, is only schematically illustrated. After a certain time of testing, by removing the holder 1 and loosening the screws 23 ', 23, 23', the leveling plate 2 is removed from the holder 1, after which it is possible to observe the measuring surface 31 and to make appropriate measurements of the rotary tester 3 and, if necessary, the stationary tester 4.

It will be appreciated by those skilled in the art that measurement may also be performed if a layer of lubricant is provided between test pieces 3, 4. The leveling of the rotary test piece 3 is also feasible without any complications if it is coated with a lubricant or if the lubricant is located at the bottom 120 in the recess 12 of the holder 1. However, in this case, it is highly recommended that the level indication devices 5, 5 ', 5, 5' are mounted on the panel 2 in a removable manner. Such an example is shown in FIG. 5 and 6. In this case, the mounting plate 2 is provided with a recess 27 and a radially rectangular hole 26 into which a carrier 55 of a leveling indication device 5 consisting of a housing 51 in which a gas-bubble 52 is available 53. The mounting bracket 55 is inserted into said hole by a tight fit and secured against the pull out by a pin 54. During the leveling, the mounting bracket 55 is thus connected to the leveling plate 2 and rotatable about the rotary axis 110 together with it and the test piece 3. completed at least a preliminary leveling, followed by a final leveling phase, e.g. with the measuring clock, or even after the leveling has been completed in general, it is possible to remove the carrier 55 together with the accessory 5 from the leveling plate 2 and begin to wear the test piece 3, in particular by using a lubricant after removing the pin 54.

The embodiment described last may also be advantageous when testing is performed at a relatively high rotation speed of the holder 1, when e.g. the presence of leveling indicating aids 5, 5 ', 5, 5' may affect the dynamic balance of the rotating parts.

Claims (14)

PATENT APPLICATIONS 1. A device for leveling the clamping assembly of a device for determining wear resistance due to a sliding friction consisting of at least a holder (1) and a rotary test piece (3), said holder having a pin (11) by means of which it can be clamped into the device thereby ensuring that the holder (1) is positioned and rotated about its axis (110), and that the rotating test piece (3) is fixed to said holder (1) in such a way that its measuring surface (31) is perpendicular to said an axis (110) of the holder (1), characterized in that it comprises at least one leveling indication device (5, 5 ', 5, 5'), which is attached to the leveling plate (2) and together with it as well as with each rotating test pieces (3) rotatable about a rotary axis (110), said accessory (5, 5 ', 5, 5') comprising at least one housing (51) in which an adequate amount of fluid is provided together (52) with the corresponding gas bladder (53). Apparatus according to claim 1, characterized in that on the same surface (21) of the leveling plate (2), as a rotating test piece (3), with a measuring surface (31), a leveling indication device (5) is designed, which is designed as a circular level. Apparatus according to claim 1, characterized in that on the same surface (21) of the leveling plate (2), as a rotary test piece (3), with a measuring surface (31), a leveling indicating device (5) is designed, which is designed as a spherical level. Device according to Claim 4, characterized in that at least two leveling devices (5 ') are provided on the same surface (21) of the leveling plate (2) as a rotary test piece (3) with a measuring surface (31). 5, 5 ') extending radially in each direction along said surface (21) of the leveling plate (2). Apparatus according to claim 1, characterized in that at least three of the leveling devices (5 ') are provided on the same surface (21) of the leveling plate (2) as a rotary test piece (3) with a measuring surface (31). 5, 5 ') extending in radial direction to each other along said surface (21) of the leveling plate (2). Device according to claim 4 or 5, characterized in that each of the leveling indications (5, 5 ', 5, 5') is located in a groove (50 ', 50, 50) available on the leveling plate (2) in the area of its upper surface (21) on which the test piece (3) is located, comprising the measuring surface (31). Device according to any one of claims 1 to 6, characterized in that the respective leveling indication device (5, 5 ', 5, 5') is connected to the leveling plate (2). Device according to any one of claims 1 to 6, characterized in that the respective leveling indication device (5, 5 ', 5, 5') is indivisibly connected to the leveling plate (2). Device according to claim 1, characterized in that the leveling indication device (5) is mounted on a carrier (55) which is detachably connected to the leveling plate (2). Device according to claim 9, characterized in that the leveling indication device (5) is mounted on a support (55) extending in the radial direction of the leveling plate (2) and which is detachably connected to the latter. Apparatus according to claim 9 and / or 10, characterized in that the leveling indication device (5) is mounted on a support (55) extending in the radial direction of the leveling plate (2) and which is detachably connected to the latter by means of a pin ( 54). Apparatus according to claim 9, characterized in that the leveling indication device (5) is mounted on a support (55) which is detachably connected to the latter in the region of the cutout (27) of the leveling plate (2). Apparatus according to claim 10, characterized in that the leveling indication device (5) is mounted on a support (55) extending in the radial direction of the leveling plate (2), designed by a notch (27) as well as by a radial hole (26), available in the region of said recess (27), said bracket (55) being inserted into said hole (26). Device according to claim 12 and / or 13, characterized in that the leveling indication device (5) is mounted on a support (55) extending in the radial direction of the leveling plate (2), designed by a notch (27) as well as by a radial a hole (26) available in the region of said recess (27), said bracket (55) being inserted into said hole (26) and secured by a pin (54) against pulling out.