ES2537098A1 - Machine for the testing of mechanical or biomechanical components (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Mechanical or biomechanical component testing machine comprising a base plate (6), four bars (1), a top plate (2) slidable on the bars (1), an intermediate plate (5) also slidable on the bars (1) ) and a lower drive base (12) pivotable on at least one horizontal axis (13), on which is fixed one end of the sample to be tested (21). The intermediate plate (5) has linear guides (7) on one of its faces, a movable table (10) movable on them and a guide (19) and follower assembly (20) on which the sample to be tested is fixed. (twenty-one). The machine allows dry or submerged tests and the application of several types of efforts. The invention is applicable in the field of engineering and, within it, in the characterization of materials and especially of biomechanical components. (Machine-translation by Google Translate, not legally binding)

Description

MECHANICAL COMPONENTS TEST MACHINE OR B10 MECHANICS

The present invention relates to a machine for carrying out tests on mechanical or biomechanical components that makes it possible to apply loads or defonations to the element to be tested in several different directions. The basic movements that are capable of applying to the element to be tested are: one axial in the vertical direction (that of the longitudinal axis of the specimen and of the testing machine), another movement perpendicular to the previous one following a straight or curvilinear path previously defined by means of a mechanical guide and follower element and a rotational one with respect to an axis perpendicular to the longitudinal axis of the element to be tested, being able to act independently one by one, combinations of two of them or all simultaneously.

The invention is applicable in the field of engineering and, within it, in the characterization from the resistant point of view of materials or components of any type, especially on biomechanical components.

STATE OF THE TECHNIQUE

At present, the known test devices are composed of one or more elements that generate displacements or loads that act jointly or independently on the element to be tested. The most conventional machines are usually uniaxial, that is, those that have the capacity to apply loads or displacements on the elements to be tested in one direction, or biaxial, which can apply loads or displacements in two directions (usually perpendicular to each other) , or in the modality of combined axial and torsional action. Less common are the machines that offer the possibility of applying loads, displacements or moments of the element to be tested according to three or more directions, normally axial.

On the other hand, the characterization of rheological behaviors, that is, as a function of time, is carried out by means of viscoelasticimeters or dynamic mechanical analyzers (Dynamic Mechanical Analyzers, DMA), which have certain limitations, either due to the reduced magnitude of the applied load , to which they are at most biaxial, or to an unsatisfactory design of the tooling to perform the tests of mechanical characterization in cut that does not allow an adequate control in the application of the transverse effort, with the consequent indefinition of the determining parameters in the test .

An example of this equipment is mentioned in patent document US 6058784 A, "Material testing apparatus having separated load generating mechanisms". It describes a test equipment that is capable of applying simultaneous linear loads and even ge: nerators of moments to a test sample in a high number of degrees of freedom based on the use of a high number of actuators . The main drawback of this type of equipment is having to need that high number of actuators, one for each movement that is intended to be generated, to achieve a complex trajectory of one of the ends of the specimen, which increases its complexity.

Another example of test equipment with the possibility of testing elements with movements in several directions is that shown in US Patent No. 7895899 82, "Multi-axis, programmable spine testing system". It is a test team with a concept similar to the one mentioned above, although it is specific for a detailed application and that allows the execution of tests on vertebral columns using multiple actuators. Its main drawback is that it is designed for a given application, in addition to the technical complexity involved in the use of a large number of actuators.

In patent document eN 103149078 A "A pull-based compression coupling torsional shear stress path triaxial" a test machine for geotechnical tests is presented which, by different elements, is capable of generating movements or loads on the element to be tested in two axial directions perpendicular to each other in addition to a rotational coincident with the axial axis of the sample. However, given the arrangement of the different elements, it is not able to reproduce complex trajectories on it. element to test.

These inventions, which can be considered representative of the current state of the art, have the main drawback in the technical complexity of having linear or angular actuators in the direction of each of the movements that are intended to be generated.

DESCRIPTION OF THE INVENTION

The present invention relates to a machine for testing mechanical or biomechanical components that allows mechanical tests, both static and dynamic, on a wide variety of components. The invention is preferably applied to biomechanical components, although it could also be applied more generically to other types of components such as engineering mechanics with appropriate modifications, if necessary. Its pennite design apply to the element to test loads or displacements in several different orientations.

The machine for performing mechanical or biomechanical tests of the invention comprises:

A structural annazón, which supports the whole and ensures its stability, which at its once it comprises a base plate, four bars attached perpendicular to said base on its periphery and a sliding top plate on the bars by means of sliding media An intermediate plate, interposed between the base plate and the top plate, sliding on the bars by :: rolling means and comprising linear guides on one of their faces. A movable mobile table on the linear guides of the intennedia plate. A set of guide and follower located on the mobile table, the follower in turn It is movable on the guide, and on it the sample to be tested is fixed. Retention means that immobilize the mobile table and the guide element in any position along the linear guides. A lower drive base, pivotable on at least one horizontal axis, on which one end of the sample to be tested is fixed.

Controlled horizontal motor means that move the mobile table or the follower, controlled vertical motor means that move the plate intentionally and controlled angular motor means that rotate the lower pivotable drive base. A means of acquiring test data.

In a preferred embodiment, the sliding means on which the upper plate slides are open bushings that are closed by means of thymes. The bushings facilitate the vertical displacement of the upper plate on the four bars that serve as guide columns and also function as an immobilization device that when closed can make the upper plate integral to the columns in any vertical position. When the bushings are open, they allow the movement of the top plate. This system allows the regulation of the size of the useful test area.

In another preferred embodiment, the rolling means on which the intermediate plate slides are linear bearings. The intermediate plate is located below the previously referenced and therein, on its periphery, linear bearings that allow its free movement in vertical direction on the bars are placed. The intent plate is driven by vertical motor means, which in another preferred embodiment are a linear actuator. In this way, the vertical linear actuator fixed to the upper plate will actuate the intermediate plate vertically, which will mean applying a vertical load or displacement to the sample to be tested, static or dynamic depending on the type of actuator.

A movable table is placed on the intention plate, which can be moved horizontally on two linear guides and which can be driven by horizontal motor means.

In another specific embodiment, the horizontal motor means are attachable and detachable to the machine in two positions, of the intended plate, by means of fixing means. Depending on the position they occupy, the horizontal motor means move the moving table or the follower that moves along the path defined by the guide.

In another specific embodiment, the guide on which the tracker travels comprises two homologous grooves that describe a linear path and / or tracker travel curve. In another more specific embodiment, the follower comprises a prismatic plate with four integrated rollers that move along the path defined by the grooves. The devices suitable for fixing one of the ends of the sample to be tested are placed on the prismatic plate.

With the elements described above, it is possible to apply displacements, and therefore loads, to the sample, which can be decomposed in three different vector directions: one in the direction of the vertical axis of the sample to be tested and two others perpendicular to said axis; that is to say, one of tension-compression and another one of cut in two different orientations, even with variable orientation depending on the position of the actuator.

In another preferred embodiment, the horizontal motor means and / or the vertical motor means and / or the angular motor means are a linear actuator that provides a static or dynamic uniaxial load or displacement, depending on the type of actuator. In a preferred embodiment, the machine further comprises transmission means of movement: horizontal motor means and angular motor means. The use of transmission means is appropriate when linear actuators are used and the point of application of the load or displacement is located outside the axis of the actuator OR a linear displacement must be converted to angular or vice versa. In an even more preferred embodiment, the transmission means of the horizontal motor means to the follower is an articulated bar. In another even more preferred embodiment, the transmission means of the angular motor means to the lower drive base is a lever.

The device has a lower pivotable drive base located at the bottom of the machine, attached to a horizontal rotating shaft. In one embodiment, the horizontal axis can be a bar supported at its ends for example by means of two bearings and orientation: perpendicular to the displacement provided by the horizontal motor means of the machine. The lower drive base is rotationally driven by angular motor means that can provide oscillating table movement. On it, the tools or devices necessary for fixing one of the ends of the sample to be tested or its lower part are arranged.

In another preferred embodiment, the bottom pivotable drive base is disposed within a sealed case that allows to contain a fluid and to perform tests with the sample to be tested partially or totally submerged. In this way, it is possible to carry out tests in a fluid and controlled environment, for example with a flow and temperature control system of the tenostatic bath.

In another preferred embodiment, the test data acquisition means are load, displacement and rotation sensors associated with each WIO of the horizontal motor means, velical motor means and angular motor means.

The invention provides, compared to the devices that al.:tualmenle l.:onocen, the advantage of being able to generate, at one of the ends of the element to be tested, movements

or loads in at least three different orientations using in one of its embodiments only two linear actuators, which working together with a follower guide element can generate complex and easily modifiable test paths, which together with the possibility of regulating the angular orientation of the other end of fixation of the specimen, allows the testing of elements subjected to a complex state of solicitation typical of many biomechanical components.

This machine of mechanical or biomechanical tests, allows the application to the sample to be tested, individually or simultaneously: a load or axial displacement of compression traction, a load or transverse displacement of cut in one or two directions since it has the possibility to follow a variable path along the path of the actuator that generates it) 'a load or oscillating movement at the other end of the sample.

The machine of the invention, in one of its preferred configurations, allows the possibility of performing static or dynamic tests on components in which the test path of one of the ends of the sample has to follow a complex path mechanically and essentially predefined of cutting, thanks to the combined action of the horizontal motor half with the vertical motor half, since the latter can continuously change the fixation position of the horizontal motor medium (being integral with the intermediate plate) and thus compensate the movement of the sample to be tested in the vertical direction when the load on the sample is intended to be only cut. In addition, the other end can rotate alternately in the direction perpendicular to the axis of the test sample, which depends on the variation of its orientation, even in a continuous way, throughout the test.

Another advantage is the possibility of carrying out tests on different types of wet almosphere and simultaneously subjecting it to a complex state of loads or displacements.

The invention is applicable in the characterization from the resistant point of view of component materials of any type, including biomechanical or mechanical engineering components, mainly in the sectors of engineering, machinery and mechanical equipment, construction or health sciences.

DESCRIPTION OF THE FIGURES

In order to facilitate the understanding of what is described herein, some drawings are attached which, without being limiting of their scope, represent a practical mode of realization of the device object of this patent.

Figure I represents a perspective view from the top of the equipment.

Figure 2 is a perspective view from the bottom of the equipment.

Figure 3 represents a schematic view of the machine from the bottom, in which the guide assembly (19) and follower (20) and the arrangement of the sample to be tested (21) is presented.

Figure 4 is a detail of an assembled guide system (19) and follower (20), with its different components.

Figure 5 represents the guide system (19) with a follower (20) with four rollers (23) that move along the path defined by the grooves (22).

Figure 6 shows the different positions (26) in which the horizontal motor means (16) can be placed and the position in which the sample to be tested (21) is placed.

Figure 7 represents a pt: rspective view of the machine in which some of the directions of the displacements that are capable of applying to the sample to be tested are indicated (21): vertical displacement (a), horizontal displacements (b) and (e) y, oscillating displacement (d).

EXPLANATION OF A D ~ FORM; PREFERRED EMBODIMENT

For a better understanding of the present invention, the following preferred embodiment example is described, described in detail, which should be understood without limitation of the scope of the invention.

The machine consisted of four cylindrical steel bars (1) and vertical arrangement that were mechanized to rigidly fasten them to a square base plate (6) of stainless steel and high mass to obtain a high degree of equipment stability. On said bars (1) two prismatic aluminum plates were arranged, one upper plate (2) and oh · to intermediate plate (5). The top plate (2) was square and had four sliding means (4) integrated in its corners. To materialize the sliding means (4), open bushings were used, which allowed their movement on the four bars (1) in order to regulate the size, in a vertical direction, of the test area. The open bushings were fixed to the cylindrical bars (1) by means of thymes (18) that closed the bushings (4) during the execution of the test. The intermediate plate (5) moved over the bars

(1) freely, for which it incorporated rolling means (3) that materialized with four linear bearings arranged in the corners of the intermediate plate (5). This intermediate plate (5) was operated vertically by means of vertical motor means (8), which were an electromechanical linear actuator although it could also have been a servo-hydraulic linear actuator. The body of this

actuator was fixed to the top plate (2) by means of thymes and its mobile rod joined

the intennedia plate (5), which was able to provide said plate with movement

intermediate (5). Two guides were fixed on the underside of the intermediate plate (5)

linear (7) on which a mobile table (10) moved, which could be operated

S

directly by means of horizontal motor means (16), when these are

they engaged the machine in the proper position (26).

A guide assembly (19) and follower (20) were placed on the mobile table (10). The Guide

(19) was a prismatic aluminum plate on which two grooves were machined

(22) homologues with the trajectory that was intended to be applied to one of the ends of the

10

Sample to be tested (21). Following these guides, a follower element moved

(20), consisting of a prismatic plate on which four rollers were placed (23)

in its corners, which made it move along the path defined by the

grooves (22) machined in the guide element (19). On the prismatic plate of the

follower (20) diferenws threaded drills (24) that allowed the

lS

fixation of the sample to be tested (21). For fixing the guide element (19) to the table

mobile (10), different fixing holes (15) were made on it, which also

they could have been lace, for the insertion of threaded elements, as per

example thyme, which allowed the rapid exchange between several models of the guides

(19) for the generation of different predefined paths during one or several

twenty

essays.

One of the features available on the machine and that modifies the type of

tests to be carried out is the possibility of modifying the position of the motor means

horizontal (16) by coupling them in different positions (26) in the machine. Be

they established two positions (26) available so that, depending on the

2S

position (26) to which the horizontal motor means (16) were coupled, applied

a horizontal displacement directly to the mobile table (10), or applied it

directly to the follower element (20) through an articulated bar (27). For

performing a test in this last position prevented the horizontal displacement of

the mobile table (10) and the guide (19) fixed to said mobile table, by means of

30

suitable retention means (25), which: were built on thyme. In this

configuration, with a guide element (19) with grooves (22) machined with

different forms of trajectory along its length, the mobile table (10) could be positioned so that the follower (20) followed a specific area of the guide (19). In each of these areas the movement imposed on the sample to be tested (21) is different, so that different test paths could be achieved using

5 a single guide set (19) and follower (20).

In the lower part of the machine there was a lower pivoting base (12) made of stainless steel supported on a cylindrical horizontal axis (13), also made of stainless steel, placed transversely and supported on two bearings at its ends, which allowed a rotational movement This movement was generated.

10 by an assembly consisting of angular motor means (9) and transmission means. The angular motor means (9) was another electromechanical linear actuator and the transmission means was a lever (17). On said lower drive base (12) a threaded hole zone (14) was arranged that allowed the fixing of one of the ends of the sample to be tested (21). Base

Lower actuator (12) was placed inside a sealed case (11), which allowed the tests to be carried out with the sample to be tested (21) immersed in a certain fluid. The elements necessary for the recirculation of the fluid and its thermal conditioning were arranged on said sealed box (11). The set was completed with the corresponding data acquisition means (28) in

20 the form of load, displacement and rotation sensors in each of the actuators, and the test reading and control elements.

Claims (12)

l. Machine for performing mechanical or biomechanical tests that it comprises: a structural annazon, which supports the assembly and ensures its stability, which in turn comprises a base plate (6), four bars (1) connected perpendicularly to said base (6) at its periphery and an upper plate (2) sliding on the bars (1) by means of sliding means (4); an intermediate plate (5), interposed between the base plate (6) and the upper plate (2), slidable on the bars (1) by rolling means (3) and comprising linear guides (7) in one of their faces a movable table (10) movable on the linear guides (7) of the intended plate (5); a guide assembly (19) and follower (20) movable on the guide (19) on which the sample to be tested (21) is fixed and located on the mobile table (10); retention means (25) that immobilize the movable table (10) and the guide element (19) in any position along the linear guides (7); a lower drive base (12), pi voting on at least one horizontal axis (13), on which an end of the sample to be tested (21) is fixed; controlled horizontal motor means (16) that move the movable table (10) or the follower (20), controlled vertical motor means (8) that displace the intent plate (5) and controlled angular motor means (9) that rotate the lower pivotable drive base (12); means of acquisition (28) of test data. 2. Machine according to claim 1 characterized in that the sliding means (4) on which the plate slides (; to upper (2) are open bushings that are closed by means of screws (18). 3. Machine according to claim I characterized in that the rolling means (3) on which the intention plate slides (5) are linear bearings. Machine according to claim 1 characterized in that the horizontal motor means (16) are attachable and detachable to the machine in two positions by means of fixing means (26) and move the mobile table (10) or the follower (20) in function of your position.

5.

Machine according to claim 1 characterized in that the guide (19) comprises two homologous grooves (22) describing a linear path and / or displacement curve of the follower (20).

6.

Machine according to claim 5 characterized in that the follower (20) comprises a prismatic plate with four rollers (23) that move along the path defined by the grooves (22).

7.

Machine according to claim 1, characterized in that the horizontal motor means (16) and / or the vertical motor means (8) and / or the angular motor means (9) are a linear actuator.

8.

Machine according to claim 7 characterized in that it further comprises means for transmitting the movement of the horizontal motor means (16), and the angular motor means (9).

9.

Machine according to claim 8 characterized in that the transmission means of the horizontal motor means (16) to the follower (20) is an articulated bar (27).

10.

Machine according to claim 8 characterized in that the transmission means of the angular motor means (9) to the lower drive base (12) is a lever (17).

eleven . Machine according to claim 1 characterized in that the pivotable lower drive base (12) is disposed within a sealed case (ll) that allows to contain a fluid and perform tests with the sample to be tested (21) partially or totally submerged. 12. Machine according to claim 1 characterized in that the means for acquiring test data (28) are load, displacement and rotation sensors associated with each of the horizontal motor means (16), vertical motor means (8) and means angular motors (9).